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Arun R, Gopal R, Chandrasekar VK, Lakshmanan M. Exploration of field-like torque and field-angle tunability in coupled spin-torque nano oscillators for synchronization. Chaos 2024; 34:013114. [PMID: 38198682 DOI: 10.1063/5.0173943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 12/11/2023] [Indexed: 01/12/2024]
Abstract
We investigate the influence of field-like torque and the direction of the external magnetic field on a one-dimensional array of serially connected spin-torque nano oscillators (STNOs), having free layers with perpendicular anisotropy, to achieve complete synchronization between them by analyzing the associated Landau-Lifshitz-Gilbert-Slonczewski equation. The obtained results for synchronization are discussed for the cases of 2, 10, and 100 oscillators separately. The roles of the field-like torque and the direction of the external field on the synchronization of the STNOs are explored through the Kuramoto order parameter. While the field-like torque alone is sufficient to bring out global synchronization in the system made up of a small number of STNOs, the direction of the external field is also needed to be slightly tuned to synchronize the one-dimensional array of a large number of STNOs. The formation of complete synchronization through the construction of clusters within the system is identified for the 100 oscillators. The large amplitude synchronized oscillations are obtained for small to large numbers of oscillators. Moreover, the tunability in frequency for a wide range of currents is shown for the synchronized oscillations up to 100 spin-torque oscillators. In addition to achieving synchronization, the field-like torque increases the frequency of the synchronized oscillations. The transverse Lyapunov exponents are deduced to confirm the stable synchronization in coupled STNOs due to the field-like torque and to validate the results obtained in the numerical simulations. The output power of the array is estimated to be enhanced substantially due to complete synchronization by the combined effect of field-like torque and tunability of the field-angle.
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Affiliation(s)
- R Arun
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620024, India
| | - R Gopal
- Department of Physics, Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - V K Chandrasekar
- Department of Physics, Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - M Lakshmanan
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620024, India
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2
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Gopal R, Tutuncuoglu E, Bakalov V, Wasserloos K, Li H, Lemley D, DeVito LJ, Constantinesco NJ, Reed DS, McHugh KJ, Chinnappan B, Andreas AR, Maloy A, Bain D, Alcorn JF, Pitt BR, Kaynar AM. Zinc deficiency enhances sensitivity to influenza A associated bacterial pneumonia in mice. Physiol Rep 2024; 12:e15902. [PMID: 38163670 PMCID: PMC10758336 DOI: 10.14814/phy2.15902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 12/13/2023] [Accepted: 12/13/2023] [Indexed: 01/03/2024] Open
Abstract
Although zinc deficiency (secondary to malnutrition) has long been considered an important contributor to morbidity and mortality of infectious disease (e.g. diarrhea disorders), epidemiologic data (including randomized controlled trials with supplemental zinc) for such a role in lower respiratory tract infection are somewhat ambiguous. In the current study, we provide the first preclinical evidence demonstrating that although diet-induced acute zinc deficiency (Zn-D: ~50% decrease) did not worsen infection induced by either influenza A (H1N1) or methicillin-resistant staph aureus (MRSA), Zn-D mice were sensitive to the injurious effects of superinfection of H1N1 with MRSA. Although the mechanism underlying the sensitivity of ZnD mice to combined H1N1/MRSA infection is unclear, it was noteworthy that this combination exacerbated lung injury as shown by lung epithelial injury markers (increased BAL protein) and decreased genes related to epithelial integrity in Zn-D mice (surfactant protein C and secretoglobins family 1A member 1). As bacterial pneumonia accounts for 25%-50% of morbidity and mortality from influenza A infection, zinc deficiency may be an important pathology component of respiratory tract infections.
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Affiliation(s)
- Radha Gopal
- Department of PediatricsUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Egemen Tutuncuoglu
- The Clinical Research, Investigation, and Systems Modeling of Acute Illness (CRISMA) CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of Critical Care MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Department of MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Veli Bakalov
- The Clinical Research, Investigation, and Systems Modeling of Acute Illness (CRISMA) CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of Critical Care MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Medicine InstituteAllegheny Health NetworkPittsburghPennsylvaniaUSA
| | - Karla Wasserloos
- Department of Environmental and Occupational HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
R.D. 2PortersvillePennsylvaniaUSA
| | - HuiHua Li
- Department of Environmental and Occupational HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Department of PathologyUniversity of WisconsinMadisonWisconsinUSA
| | - David Lemley
- Department of Environmental and Occupational HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
R.D. 2PortersvillePennsylvaniaUSA
| | - Louis J. DeVito
- Department of PediatricsUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | | | - Douglas S. Reed
- Center for Vaccine ResearchUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Kevin J. McHugh
- Department of PediatricsUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Baskaran Chinnappan
- Department of PediatricsUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Alexis R. Andreas
- Department of Critical Care MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
- Present address:
Department of MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Abigail Maloy
- Department of Critical Care MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Daniel Bain
- Department of Geology and Planetary ScienceUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - John F. Alcorn
- Department of PediatricsUPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Bruce R. Pitt
- Department of Environmental and Occupational HealthUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Ata Murat Kaynar
- The Clinical Research, Investigation, and Systems Modeling of Acute Illness (CRISMA) CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of Critical Care MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of Anesthesiology and Perioperative MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
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3
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Constantinesco NJ, Chinnappan B, DeVito LJ, Moras C, Srikanth S, Garcia-Hernandez MDLL, Rangel-Moreno J, Gopal R. Sodium-Glucose Cotransporter-2 Inhibitor, Empagliflozin, Suppresses the Inflammatory Immune Response to Influenza Infection. Immunohorizons 2023; 7:861-871. [PMID: 38112660 PMCID: PMC10759161 DOI: 10.4049/immunohorizons.2300077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 11/21/2023] [Indexed: 12/21/2023] Open
Abstract
Influenza is a highly contagious, acute respiratory disease that causes significant public health and economic threats. Influenza infection induces various inflammatory mediators, IFNs, and recruitment of inflammatory cells in the host. This inflammatory "cytokine storm" is thought to play a role in influenza-induced lung pathogenesis. Empagliflozin is a drug primarily used to lower blood glucose in type II diabetes patients by inhibiting the sodium-glucose cotransporter-2 (SGLT-2) found in the proximal tubules in the kidneys. In this study, we have investigated the effects of empagliflozin on the pulmonary immune response to influenza infection. C57BL/6 mice (wild type) were infected with influenza A/PR/8/34 and treated with empagliflozin, and the disease outcomes were analyzed. Empagliflozin treatment decreased the expression of the inflammatory cytokines IL-1β, IL-6, and CCL2; the percentage of inflammatory monocytes and inducible NO synthase-positive macrophages; and IFN response genes Stat1 and CXCL9 during influenza infection. Further, empagliflozin treatment decreases the expression of IL-6, CCL2, and CCL5 in RAW264.7 macrophages and bone marrow-derived macrophages. However, empagliflozin treatment increased influenza viral titer during infection. Despite fostering an increased viral burden, treatment with empagliflozin decreases the mortality in wild type and high fat diet-induced atherosclerotic LDLR-/- mice. Based on our findings, empagliflozin may have therapeutic implications for use in patients to prevent lung damage and acute respiratory illness.
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Affiliation(s)
- Nicholas J. Constantinesco
- Department of Pediatrics, University of Pittsburgh, University of Pittsburgh Medical Center, Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | - Baskaran Chinnappan
- Department of Pediatrics, University of Pittsburgh, University of Pittsburgh Medical Center, Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | - Louis J. DeVito
- Department of Pediatrics, University of Pittsburgh, University of Pittsburgh Medical Center, Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | - Crystal Moras
- Department of Pediatrics, University of Pittsburgh, University of Pittsburgh Medical Center, Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | - Sashwath Srikanth
- Department of Pediatrics, University of Pittsburgh, University of Pittsburgh Medical Center, Children’s Hospital of Pittsburgh, Pittsburgh, PA
| | | | - Javier Rangel-Moreno
- Division of Allergy, Immunology and Rheumatology, Department of Medicine, University of Rochester, Rochester, NY
| | - Radha Gopal
- Department of Pediatrics, University of Pittsburgh, University of Pittsburgh Medical Center, Children’s Hospital of Pittsburgh, Pittsburgh, PA
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Gopal R, Ambiha R, Sivasubramanian N, Bhupendrabhai PV, Itishaben Girishbhai SI, Govindbhai SN, Narendrabhai SD, Jigneshkumar SN, Rameshbhai VA. Effect of curry leaves in lowering blood pressure among hypertensive Indian patients. Bioinformation 2023; 19:1020-1024. [PMID: 37969660 PMCID: PMC10640786 DOI: 10.6026/973206300191020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/17/2023] Open
Abstract
Hypertension, commonly known as high or rising blood pressure, is characterized by a consistently elevated blood arterial pressure. It is a significant medical condition called hypertension raises your risk of developing problems with your heart, brain, kidneys, and other organs. Curry leaves work well as a treatment for high blood pressure. Curry leaves are thought to have a potent therapeutic impact for the treatment of high blood pressure since they are low in salt and high in potassium. Therefore, it is of interest to reduce the level of blood pressure among adults in rural area with the help of curry leaves. According to the statistical analysis, the experimental group's post-test mean score for hypertension was 155 with a standard deviation of 13.892 while the control group's post-test mean score was 162 with a standard deviation of 17.20. The estimated unpaired value of t = 11.07 was deemed to be statistically significant at the p 0.05 level and the mean difference was 7. As a result, the null hypothesis was rejected and the research hypothesis was accepted. Giving Curry leaf powder to patients with hypertension as a consequence was an effective intervention.
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Affiliation(s)
- R Gopal
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | - R Ambiha
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | - N Sivasubramanian
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
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5
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Ambiha R, Gopal R, Siva Subramanian N, Patel Bansi G, Patel Dhenu G, Patel Dharmik B, Patel Disha V, Patel Heli A, Patel Janu N. Knowledge on mucormycosis among nursing Indian students in the state of Gujarat. Bioinformation 2023; 19:1003-1006. [PMID: 37969661 PMCID: PMC10640785 DOI: 10.6026/973206300191003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 10/31/2023] [Accepted: 10/31/2023] [Indexed: 11/17/2023] Open
Abstract
The disorder known as angio-invasive mucormycosis is characterized by tissue necrosis and infarction. The Mucorales order of saprophytic fungi is responsible for its development. It is unclear how widespread mucormycosis is in India due to a lack of population-based investigations. Diabetes mellitus is the risk factor that occurs the most frequently, followed by solid organ transplant and hematological cancer. The present study has been carried out to assess the knowledge regarding mucormycosis among nursing students from Nootan College of Nursing, Visnagar, Gujarat. For this we have selected 100 students by using the probability sampling technique. Structured questions were used to assess the knowledge of nursing students regarding mucormycosis. The Score was categorized as poor, average and good. The results show that 45(45%) of the nursing students having poor knowledge, 35(35%) of them were having average knowledge, 20(20%) of them were having good knowledge. There is an association between gender, program and their level of knowledge. Most of the students having poor knowledge regarding mucormycosis and we need to create awareness regarding mucormycosis to Nursing students.
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Affiliation(s)
- R Ambiha
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | - R Gopal
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | - N Siva Subramanian
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | | | - Grishbhai Patel Dhenu
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | | | - Vikrambhai Patel Disha
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | - Alpeshkumar Patel Heli
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
| | - Nareshbhai Patel Janu
- Nootan College of Nursing, Sankalchand Patel University, Visnagar, Gujarat-384315, India
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6
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Manoranjani M, Saiprasad VR, Gopal R, Senthilkumar DV, Chandrasekar VK. Phase transitions in an adaptive network with the global order parameter adaptation. Phys Rev E 2023; 108:044307. [PMID: 37978685 DOI: 10.1103/physreve.108.044307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/29/2023] [Indexed: 11/19/2023]
Abstract
We consider an adaptive network of Kuramoto oscillators with purely dyadic coupling, where the adaption is proportional to the degree of the global order parameter. We find only the continuous transition to synchronization via the pitchfork bifurcation, an abrupt synchronization (desynchronization) transition via the pitchfork (saddle-node) bifurcation resulting in the bistable region R_{1}. This is a smooth continuous transition to a weakly synchronized state via the pitchfork bifurcation followed by a subsequent abrupt transition to a strongly synchronized state via a second saddle-node bifurcation along with an abrupt desynchronization transition via the first saddle-node bifurcation resulting in the bistable region R_{2} between the weak and strong synchronization. The transition goes from the bistable region R_{1} to the bistable region R_{2}, and transition from the incoherent state to the bistable region R_{2} as a function of the coupling strength for various ranges of the degree of the global order parameter and the adaptive coupling strength. We also find that the phase-lag parameter enlarges the spread of the weakly synchronized state and the bistable states R_{1} and R_{2} to a large region of the parameter space. We also derive the low-dimensional evolution equations for the global order parameters using the Ott-Antonsen ansatz. Further, we also deduce the pitchfork, first and second saddle-node bifurcation conditions, which is in agreement with the simulation results.
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Affiliation(s)
- M Manoranjani
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - V R Saiprasad
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - R Gopal
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - D V Senthilkumar
- School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram-695016, India
| | - V K Chandrasekar
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
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Saiprasad VR, Gopal R, Senthilkumar DV, Chandrasekar VK. Monkeypox: a model-free analysis. Eur Phys J Plus 2023; 138:138. [PMID: 36785810 PMCID: PMC9908498 DOI: 10.1140/epjp/s13360-023-03709-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Monkeypox is a zoonotic disease caused by a virus that is a member of the orthopox genus, which has been causing an outbreak since May 2022 around the globe outside of its country of origin Democratic Republic of the Congo, Africa. Here we systematically analyze the data of cumulative infection per day adapting model-free analysis, in particular, statistically using the power law distribution, and then separately we use reservoir computing-based Echo state network (ESN) to predict and forecast the disease spread. We also use the power law to characterize the country-specific infection rate which will characterize the growth pattern of the disease spread such as whether the disease spread reached a saturation state or not. The results obtained from power law method were then compared with the outbreak of the smallpox virus in 1907 in Tokyo, Japan. The results from the machine learning-based method are also validated by the power law scaling exponent, and the correlation has been reported.
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Affiliation(s)
- V. R. Saiprasad
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
| | - R. Gopal
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
| | - D. V. Senthilkumar
- School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram, 695016 India
| | - V. K. Chandrasekar
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
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8
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Kaviya B, Gopal R, Suresh R, Chandrasekar VK. Route to extreme events in a parametrically driven position-dependent nonlinear oscillator. Eur Phys J Plus 2023; 138:36. [PMID: 36686497 PMCID: PMC9842500 DOI: 10.1140/epjp/s13360-022-03625-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/22/2022] [Indexed: 06/14/2023]
Abstract
We explore the dynamics of a damped and driven Mathews-Lakshmanan oscillator type model with position-dependent mass term and report two distinct bifurcation routes to the advent of sudden, intermittent large-amplitude chaotic oscillations in the system. We characterize these infrequent and recurrent large oscillations as extreme events (EE) when they are significantly greater than the pre-defined threshold height. In the first bifurcation route, the system exhibits a bifurcation from quasiperiodic (QP) attractor to chaotic attractor via strange non-chaotic (SNA) attractor as a function of damping parameter. In the second route, the chaotic attractor in the form of EE has emerged directly from the QP attractor. Hence, to the best of our knowledge, this is the first study to report the birth of EE from these two distinct bifurcation routes. We also discuss that EE are emerged due to the sudden expansion of the chaotic attractor via interior crisis in the system. Regions of different dynamical states are distinguished using the Lyapunov exponent spectrum. Further, SNA and QP dynamics are determined using the singular spectrum analysis and 0-1 test. The region of EE is characterized using the threshold height.
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Affiliation(s)
- B. Kaviya
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
| | - R. Gopal
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
| | - R. Suresh
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
| | - V. K. Chandrasekar
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
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9
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Saiprasad VR, Gopal R, Chandrasekar VK, Lakshmanan M. Analysis of COVID-19 in India using a vaccine epidemic model incorporating vaccine effectiveness and herd immunity. Eur Phys J Plus 2022; 137:1003. [PMID: 36092468 PMCID: PMC9444102 DOI: 10.1140/epjp/s13360-022-03216-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/20/2022] [Indexed: 06/15/2023]
Abstract
COVID-19 will be a continuous threat to human population despite having a few vaccines at hand until we reach the endemic state through natural herd immunity and total immunization through universal vaccination. However, the vaccine acts as a practical tool for reducing the massive public health problem and the emerging economic consequences that the continuing COVID -19 epidemic is causing worldwide, while the vaccine efficacy wanes. In this work, we propose and analyze an epidemic model of Susceptible-Exposed-Infected-Recovered-Vaccinated population taking into account the rate of vaccination and vaccine waning. The dynamics of the model has been investigated, and the condition for a disease-free endemic equilibrium state is obtained. Further, the analysis is extended to study the COVID-19 spread in India by considering the availability of vaccines and the related critical parameters such as vaccination rate, vaccine efficacy and waning of vaccine's impact on deciding the emerging fate of this epidemic. We have also discussed the conditions for herd immunity due to vaccinated individuals among the people. Our results highlight the importance of vaccines, the effectiveness of booster vaccination in protecting people from infection, and their importance in epidemic and pandemic modeling.
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Affiliation(s)
- V. R. Saiprasad
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613401 India
| | - R. Gopal
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613401 India
| | - V. K. Chandrasekar
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613401 India
| | - M. Lakshmanan
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirappalli, 620024 India
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10
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Manoranjani M, Gopal R, Senthilkumar DV, Chandrasekar VK, Lakshmanan M. Influence of asymmetric parameters in higher-order coupling with bimodal frequency distribution. Phys Rev E 2022; 105:034307. [PMID: 35428136 DOI: 10.1103/physreve.105.034307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
We investigate the phase diagram of the Sakaguchi-Kuramoto model with a higher-order interaction along with the traditional pairwise interaction. We also introduce asymmetry parameters in both the interaction terms and investigate the collective dynamics and their transitions in the phase diagrams under both unimodal and bimodal frequency distributions. We deduce the evolution equations for the macroscopic order parameters and eventually derive pitchfork and Hopf bifurcation curves. Transition from the incoherent state to standing wave pattern is observed in the presence of the unimodal frequency distribution. In contrast, a rich variety of dynamical states such as the incoherent state, partially synchronized state-I, partially synchronized state-II, and standing wave patterns and transitions among them are observed in the phase diagram via various bifurcation scenarios, including saddle-node and homoclinic bifurcations, in the presence of bimodal frequency distribution. Higher-order coupling enhances the spread of the bistable regions in the phase diagrams and also leads to the manifestation of bistability between incoherent and partially synchronized states even with unimodal frequency distribution, which is otherwise not observed with the pairwise coupling. Further, the asymmetry parameters facilitate the onset of several bistable and multistable regions in the phase diagrams. Very large values of the asymmetry parameters allow the phase diagrams to admit only the monostable dynamical states.
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Affiliation(s)
- M Manoranjani
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - R Gopal
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - D V Senthilkumar
- School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram 695016, India
| | - V K Chandrasekar
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, India
| | - M Lakshmanan
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620 024, India
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11
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Sen S, Mandal S, Sen A, Gopal R, Ben Ltaief L, Turchini S, Catone D, Zema N, Coreno M, Richter R, Mudrich M, Krishnan SR, Sharma V. Fragmentation dynamics of doubly charged camphor molecule following C 1s Auger decay. Phys Chem Chem Phys 2022; 24:2944-2957. [PMID: 35076648 DOI: 10.1039/d1cp05176h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fragmentation dynamics of the gas-phase, doubly charged camphor molecule, formed by Auger decay following carbon 1s ionisation, using soft X-ray synchrotron radiation, is presented in this work. The technique of velocity map imaging combined with a photoelectron-photoion-photoion coincidence (VMI-PEPIPICO) is used for both electron energy and ion momentum (in-sequence) measurements. The experimental study is complemented by molecular dynamics simulation, performed with an NVT (moles, volume, and temperature) ensemble. Velocity Verlet algorithms were used for time integration at various internal energies. These simulations validate observed dissociation pathways. From these, we successfully deduce that the internal energy of the doubly charged molecular ion has a significant contribution to the fragmentation mechanism. Notably, a prominent signature of the internal energy was observed in the experimentally determined energies of the neutral fragment in these deferred charge separation pathways, entailing a more detailed theoretical study to uncover the exact dissociation dynamics.
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Affiliation(s)
- Sanket Sen
- Indian Institute of Technology Hyderabad, Kandi 502285, India.
| | - S Mandal
- Indian Institute of Science Education and Research, Pune 411008, India
| | - Arnab Sen
- Indian Institute of Science Education and Research, Pune 411008, India
| | - R Gopal
- Tata Institute of Fundamental Research, Hyderabad 500046, India
| | | | - S Turchini
- Istituto di Struttura della Materia - CNR (ISM-CNR), Area di Ricerca di Tor Vergata via del Fosso del Cavaliere, 100, Rome 00133, Italy
| | - D Catone
- Istituto di Struttura della Materia - CNR (ISM-CNR), Area di Ricerca di Tor Vergata via del Fosso del Cavaliere, 100, Rome 00133, Italy
| | - N Zema
- Istituto di Struttura della Materia - CNR (ISM-CNR), Area di Ricerca di Tor Vergata via del Fosso del Cavaliere, 100, Rome 00133, Italy
| | - M Coreno
- Elettra-Sincrotrone Trieste, Basovizza 34149, Italy.,Consiglio Nazionale delle Ricerche - Istituto di Struttura della Materia, Trieste 34149, Italy
| | - R Richter
- Elettra-Sincrotrone Trieste, Basovizza 34149, Italy
| | - M Mudrich
- Aarhus University, 8000 Aarhus C, Denmark.,QuCenDiEM - group and Department of Physics, Indian Institute of Technology - Madras, Chennai 600036, India.
| | - S R Krishnan
- QuCenDiEM - group and Department of Physics, Indian Institute of Technology - Madras, Chennai 600036, India.
| | - V Sharma
- Indian Institute of Technology Hyderabad, Kandi 502285, India.
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12
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Atti A, Ferrari M, Castillo-Olivares J, Monk E, Gopal R, Patel M, Hoschler K, Cole M, Semper A, Hewson J, Otter A, Foulkes S, Islam J, Mirfenderesky M, Jain S, Murira J, Favager C, Nastouli E, Chand M, Brown C, Heeney J, Brooks T, Hall V, Hopkins S, Zambon M. Serological profile of first SARS-CoV-2 reinfection cases detected within the SIREN study. J Infect 2022; 84:248-288. [PMID: 34600935 PMCID: PMC8482544 DOI: 10.1016/j.jinf.2021.09.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 09/26/2021] [Indexed: 12/15/2022]
Affiliation(s)
- A. Atti
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK,Correspondence author
| | - M. Ferrari
- Department of Veterinary Medicine, Laboratory of Viral Zoonotics (LVZ) and HICC (Humoral Immune Correlates from COVID-19), University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - J. Castillo-Olivares
- Department of Veterinary Medicine, Laboratory of Viral Zoonotics (LVZ) and HICC (Humoral Immune Correlates from COVID-19), University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - E.J.M. Monk
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - R. Gopal
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - M. Patel
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - K. Hoschler
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - M.J. Cole
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - A. Semper
- Public Health England (PHE), Porton Down, Salisbury SP4 0JG, UK
| | - J. Hewson
- Public Health England (PHE), Porton Down, Salisbury SP4 0JG, UK
| | - A.D. Otter
- Public Health England (PHE), Porton Down, Salisbury SP4 0JG, UK
| | - S. Foulkes
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - J. Islam
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - M. Mirfenderesky
- North Middlesex University Hospital NHS Trust, Sterling Way, London N18 1QX, UK
| | - S. Jain
- North Middlesex University Hospital NHS Trust, Sterling Way, London N18 1QX, UK
| | - J. Murira
- Leeds Teaching Hospitals NHS Trust, Great George St, Leeds LS1 3EX, UK
| | - C. Favager
- Leeds Teaching Hospitals NHS Trust, Great George St, Leeds LS1 3EX, UK
| | - E. Nastouli
- Department of Clinical Virology, University College London Hospitals NHS Foundation Trust, 250 Euston Rd, London NW1 2PG, UK,Department of Infection, Immunity and Inflammation, UCL Great Ormond Street Institute of Child Health, 30 Guilford St, London WC1N 1EH, UK
| | - M.A. Chand
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - C.S. Brown
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - J.L. Heeney
- Department of Veterinary Medicine, Laboratory of Viral Zoonotics (LVZ) and HICC (Humoral Immune Correlates from COVID-19), University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - T. Brooks
- Public Health England (PHE), Porton Down, Salisbury SP4 0JG, UK
| | - V.J. Hall
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - S. Hopkins
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
| | - M. Zambon
- Public Health England (PHE), PHE Colindale, 61 Colindale Avenue, London NW9 5EQ, UK
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13
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Gopal R, Chandrasekar VK, Lakshmanan M. Analysis of the second wave of COVID-19 in India based on SEIR model. Eur Phys J Spec Top 2022; 231:3453-3460. [PMID: 35039761 PMCID: PMC8756415 DOI: 10.1140/epjs/s11734-022-00426-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/18/2021] [Indexed: 06/14/2023]
Abstract
India was under a grave threat from the second wave of the COVID-19 pandemic particularly in the beginning of May 2021. The situation appeared rather gloomy as the number of infected individuals/active cases had increased alarmingly during the months of May and June 2021 compared to the first wave peak. Indian government/state governments have been implementing various control measures such as lockdowns, setting up new hospitals, and putting travel restrictions at various stages to lighten the virus spread from the initial outbreak of the pandemic. Recently, we have studied the susceptible-exposed-infectious-removed (SEIR) dynamic modeling of the epidemic evolution of COVID-19 in India with the help of appropriate parameters quantifying the various governmental actions and the intensity of individual reactions. Our analysis had predicted the scenario of the first wave quite well. In this present article, we extend our analysis to estimate and analyze the number of infected individuals during the second wave of COVID-19 in India with the help of the above SEIR model. Our findings show that the people's individual effort along with governmental actions such as implementations of curfews and accelerated vaccine strategy are the most important factors to control the pandemic in the present situation and in the future.
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Affiliation(s)
- R Gopal
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
| | - V K Chandrasekar
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 India
| | - M Lakshmanan
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirappalli, 620 014 Tamil Nadu India
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14
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Arun R, Gopal R, Chandrasekar VK, Lakshmanan M. Spin torque oscillations triggered by in-plane field. J Phys Condens Matter 2022; 34. [PMID: 34933295 DOI: 10.1088/1361-648x/ac452f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
We study the dynamics of a spin torque nano oscillator that consists of parallelly magnetized free and pinned layers by numerically solving the associated Landau-Lifshitz-Gilbert-Slonczewski equation in the presence of a field-like torque. We observe that an in-plane magnetic field which is applied for a short interval of time (<1 ns) triggers the magnetization to exhibit self-oscillations from low energy initial magnetization state. Also, we confirm that the frequency of oscillations can be tuned over the range ∼25-∼72 GHz by current, even in the absence of field-like torque. We find the frequency enhancement up to 10 GHz by the presence of field-like torque. We determine theQ-factor for different frequencies and show that it increases with frequency. Our analysis with thermal noise confirms that the system is stable against thermal noise and the dynamics is not altered appreciably by it.
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Affiliation(s)
- R Arun
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India
| | - R Gopal
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur-613 401, India
| | - V K Chandrasekar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur-613 401, India
| | - M Lakshmanan
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India
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15
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Manoranjani M, Gopal R, Senthilkumar DV, Chandrasekar VK. Role of phase-dependent influence function in the Winfree model of coupled oscillators. Phys Rev E 2021; 104:064206. [PMID: 35030866 DOI: 10.1103/physreve.104.064206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
We consider a globally coupled Winfree model comprised of a phase-dependent influence function and sensitive function, and unravel the impact of offset and integer parameters, characterizing the shape of the influence function, on the phase diagram of the Winfree model. The decreasing value of the offset parameter decreases the degree of positive phase shift among the oscillators by promoting the negative phase shift, which indeed favors the onset of multistability among the synchronous oscillatory state and asynchronous stable steady states in a large region of the phase diagram. Further, large integer parameters lead to brief pulses of the influence function, which again enhances the effect of the offset parameter. There is an explosive transition to a synchronous oscillatory state from an asynchronous steady state via a Hopf bifurcation. Dynamical transitions and multistability emerge through saddle-node, pitchfork, and homoclinic bifurcations in the phase diagram. We deduce two ordinary differential equations corresponding to the two macroscopic variables from the population of globally coupled Winfree oscillators using the Ott-Antonsen ansatz. We also deduce various bifurcation curves analytically from the reduced low-dimensional macroscopic variables for the exactly solvable case. The analytical curves exactly match the simulation boundaries in the phase diagram.
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Affiliation(s)
- M Manoranjani
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613401, India
| | - R Gopal
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613401, India
| | - D V Senthilkumar
- School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram 695016, India
| | - V K Chandrasekar
- Department of Physics, Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur 613401, India
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16
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Mandal S, Gopal R, Srinivas H, D'Elia A, Sen A, Sen S, Richter R, Coreno M, Bapat B, Mudrich M, Sharma V, Krishnan SR. Coincident angle-resolved state-selective photoelectron spectroscopy of acetylene molecules: a candidate system for time-resolved dynamics. Faraday Discuss 2021; 228:242-265. [PMID: 33687396 DOI: 10.1039/d0fd00120a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The acetylene-vinylidene system serves as a benchmark for investigations of ultrafast dynamical processes where the coupling of the electronic and nuclear degrees of freedom provides a fertile playground to explore the femto- and sub-femto-second physics with coherent extreme-ultraviolet (EUV) photon sources both on the table-top as well as free-electron lasers. We focus on detailed investigations of this molecular system in the photon energy range 19-40 eV where EUV pulses can probe the dynamics effectively. We employ photoelectron-photoion coincidence (PEPICO) spectroscopy to uncover hitherto unrevealed aspects of this system. In this work, the role of excited states of the C2H2+ cation, the primary photoion, is specifically addressed. From photoelectron energy spectra and angular distributions, the nature of the dissociation and isomerization channels is discerned. Exploiting the 4π-collection geometry of the velocity map imaging spectrometer, we not only probe pathways where the efficiency of photoionization is inherently high but also perform PEPICO spectroscopy on relatively weak channels.
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Affiliation(s)
- S Mandal
- Indian Institute of Science Education and Research, Pune 411008, India
| | - R Gopal
- Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - H Srinivas
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - A D'Elia
- IOM-CNR, Laboratorio TASC, Basovizza SS-14, km 163.5, 34149 Trieste, Italy
| | - A Sen
- Indian Institute of Science Education and Research, Pune 411008, India
| | - S Sen
- Indian Institute of Technology Hyderabad, Kandi 502285, India.
| | - R Richter
- Elettra-Sincrotrone Trieste, 34149 Basovizza, Italy
| | - M Coreno
- Istituto di Struttura della Materia - Consiglio Nazionale delle Ricerche (ISM-CNR), 34149 Trieste, Italy and INFN-LNF, via Enrico Fermi 54, 00044 Frascati, Italy
| | - B Bapat
- Indian Institute of Science Education and Research, Pune 411008, India
| | - M Mudrich
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark and Department of Physics, QuCenDiEm-Group, Indian Institute of Technology Madras, Chennai 600036, India.
| | - V Sharma
- Indian Institute of Technology Hyderabad, Kandi 502285, India.
| | - S R Krishnan
- Department of Physics, QuCenDiEm-Group, Indian Institute of Technology Madras, Chennai 600036, India.
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17
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18
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Arun R, Gopal R, Chandrasekar VK, Lakshmanan M. Large amplitude spin-Hall oscillations due to field-like torque. J Phys Condens Matter 2021; 33:165402. [PMID: 33752193 DOI: 10.1088/1361-648x/abf0c1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Large amplitude spin-Hall oscillations are identified in a ferromagnetic layer with two perpendicular in-plane easy axis in the presence of field-like torque without any polarizer and external field. The analytical study confirms the possibility of oscillations in the presence of field-like torque. The investigation shows that the oscillation frequency can be tuned from ∼2 GHz to ∼80 GHz by current and enhanced by field-like torque. Further, the enhancement of frequency along with theQ-factor by current and field-like torque is also observed.
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Affiliation(s)
- R Arun
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India
| | - R Gopal
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur- 613 401, India
| | - V K Chandrasekar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur- 613 401, India
| | - M Lakshmanan
- Department of Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India
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Abstract
Influenza virus infection causes 3-5 million cases of severe illness and 250,000-500,000 deaths worldwide annually. Although pneumonia is the most common complication associated with influenza, there are several reports demonstrating increased risk for cardiovascular diseases. Several clinical case reports, as well as both prospective and retrospective studies, have shown that influenza can trigger cardiovascular events including myocardial infarction (MI), myocarditis, ventricular arrhythmia, and heart failure. A recent study has demonstrated that influenza-infected patients are at highest risk of having MI during the first seven days of diagnosis. Influenza virus infection induces a variety of pro-inflammatory cytokines and chemokines and recruitment of immune cells as part of the host immune response. Understanding the cellular and molecular mechanisms involved in influenza-associated cardiovascular diseases will help to improve treatment plans. This review discusses the direct and indirect effects of influenza virus infection on triggering cardiovascular events. Further, we discussed the similarities and differences in epidemiological and pathogenic mechanisms involved in cardiovascular events associated with coronavirus disease 2019 (COVID-19) compared to influenza infection.
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Affiliation(s)
- Radha Gopal
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, United States
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20
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Chandran P, Gopal R, Chandrasekar VK, Athavan N. Chimera-like states induced by additional dynamic nonlocal wirings. Chaos 2020; 30:063106. [PMID: 32611102 DOI: 10.1063/1.5144929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Abstract
We investigate the existence of chimera-like states in a small-world network of chaotically oscillating identical Rössler systems with an addition of randomly switching nonlocal links. By varying the small-world coupling strength, we observe no chimera-like state either in the absence of nonlocal wirings or with static nonlocal wirings. When we give an additional nonlocal wiring to randomly selected nodes and if we allow the random selection of nodes to change with time, we observe the onset of chimera-like states. Upon increasing the number of randomly selected nodes gradually, we find that the incoherent window keeps on shrinking, whereas the chimera-like window widens up. Moreover, the system attains a completely synchronized state comparatively sooner for a lower coupling strength. Also, we show that one can induce chimera-like states by a suitable choice of switching times, coupling strengths, and a number of nonlocal links. We extend the above-mentioned randomized injection of nonlocal wirings for the cases of globally coupled Rössler oscillators and a small-world network of coupled FitzHugh-Nagumo oscillators and obtain similar results.
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Affiliation(s)
- P Chandran
- Department of Physics, H. H. The Rajah's College (affiliated to Bharathidasan University), Pudukkottai 622 001, Tamil Nadu, India
| | - R Gopal
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, Tamil Nadu, India
| | - V K Chandrasekar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, Tamil Nadu, India
| | - N Athavan
- Department of Physics, H. H. The Rajah's College (affiliated to Bharathidasan University), Pudukkottai 622 001, Tamil Nadu, India
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21
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Mandal S, Gopal R, Shcherbinin M, D'Elia A, Srinivas H, Richter R, Coreno M, Bapat B, Mudrich M, Krishnan SR, Sharma V. Penning spectroscopy and structure of acetylene oligomers in He nanodroplets. Phys Chem Chem Phys 2020; 22:10149-10157. [PMID: 32347252 DOI: 10.1039/d0cp00689k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Embedded atoms or molecules in a photoexcited He nanodroplet are well-known to be ionized through inter-atomic relaxation in a Penning process. In this work, we investigate the Penning ionization of acetylene oligomers occurring from the photoexcitation bands of He nanodroplets. In close analogy to conventional Penning electron spectroscopy by thermal atomic collisions, the n = 2 photoexcitation band plays the role of the metastable atomic 1s2s 3,1S He*. This facilitates electron spectroscopy of acetylene aggregates in the sub-Kelvin He environment, providing the following insight into their structure: the molecules in the dopant cluster are loosely bound van der Waals complexes rather than forming covalent compounds. In addition, this work reveals a Penning process stemming from the n = 4 band where charge-transfer from autoionized He in the droplets is known to be the dominant relaxation channel. This allows for excited states of the remnant dopant oligomer Penning-ions to be studied. Hence, we demonstrate Penning ionization electron spectroscopy of doped droplets as an effective technique for investigating dopant oligomers which are easily formed by attachment to the host cluster.
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Affiliation(s)
- S Mandal
- Indian Institute of Science Education and Research, Pune 411008, India
| | - R Gopal
- Tata Institute of Fundamental Research, Hyderabad 500107, India
| | | | - A D'Elia
- Department of Physics, University of Trieste, Via A. Valerio 2, 34127 Trieste, Italy
| | - H Srinivas
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - R Richter
- Elettra-Sincrotrone Trieste, 34149 Basovizza, Italy
| | - M Coreno
- Elettra-Sincrotrone Trieste, 34149 Basovizza, Italy and Consiglio Nazionale delle Ricerche - Istituto di Struttura della Materia, 34149 Trieste, Italy
| | - B Bapat
- Indian Institute of Science Education and Research, Pune 411008, India
| | - M Mudrich
- Aarhus University, 8000 Aarhus C, Denmark and Indian Institute of Technology Madras, Chennai 600036, India.
| | - S R Krishnan
- Indian Institute of Technology Madras, Chennai 600036, India.
| | - V Sharma
- Indian Institute of Technology Hyderabad, Kandi 502285, India.
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22
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Sen A, Sairam T, Sahu SR, Bapat B, Gopal R, Sharma V. Hindered alignment in ultrashort, intense laser-induced fragmentation of O 2. J Chem Phys 2020; 152:014302. [PMID: 31914771 DOI: 10.1063/1.5130706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecules ionized by intense (10-100 TW/cm2) and ultrashort (tens of femtoseconds) laser fields undergo rotation and alignment mediated through their polarizability. The expected alignment is indeed observed in the case of O2 molecules ionized by intense laser pulses of 800 nm wavelength and 25 fs duration, as observed through velocity imaging of the fragments. Strikingly, when 35 fs pulses of 400 nm wavelength of comparable intensity are employed, an anomalous hindering of this alignment is observed. In both cases, we propose dissociation pathways for the energetic ions consistent with the recorded kinetic energy distributions. Using a semiclassical model of induced rotation of the molecular ion that involves polarizabilities of the participating excited states, both behaviors are reproduced. The model suggests that the difference in the observations can be attributed to a transient negative polarizability in an intermediate state of the proposed pathway.
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Affiliation(s)
- Arnab Sen
- Indian Institute of Science Education and Research, Pune 411008, India
| | - T Sairam
- Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - S R Sahu
- Indian Institute of Technology Hyderabad, Kandi 502285, India
| | - Bhas Bapat
- Indian Institute of Science Education and Research, Pune 411008, India
| | - R Gopal
- Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - V Sharma
- Indian Institute of Technology Hyderabad, Kandi 502285, India
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23
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Arunvinthan S, Gopal R, Chandrasekar VK, Nadaraja Pillai S. Recurrence analysis of surface pressure characteristics over symmetrical aerofoil. Chaos 2020; 30:013116. [PMID: 32013478 DOI: 10.1063/1.5121569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
We study the surface pressure data exhibiting the underlying dynamical behavior of the flow transition over the upper surface of the aerofoil by using recurrence quantification analysis (RQA). In this study, NACA 2415 aerofoil subjected to a turbulent inflow of TI=8.46% at various angles of attack ranging from α=0° to 20° with an increment of 5° corresponding to Re=2.0×105 is considered. We show that the values of recurrence quantification measures effectively distinguish the underlying dynamics of time series surface pressure data at each port, which proves RQA as an effective tool in accurately predicting the flow transitions.
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Affiliation(s)
- S Arunvinthan
- Turbulence & Flow Control Laboratory, School of Mechanical Engineering, SASTRA Deemed University, Thanjavur, Tamilnadu 613 401, India
| | - R Gopal
- Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, Tamilnadu 613 401, India
| | - V K Chandrasekar
- Centre for Nonlinear Science and Engineering, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, Tamilnadu 613 401, India
| | - S Nadaraja Pillai
- Turbulence & Flow Control Laboratory, School of Mechanical Engineering, SASTRA Deemed University, Thanjavur, Tamilnadu 613 401, India
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24
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Sarkar S, Gopal R, Anand M, Kumar MP, Krishnamurthy M. On the importance of field driven single particle processes in short pulse absorption of clusters. Sci Rep 2019; 9:15135. [PMID: 31641204 PMCID: PMC6805859 DOI: 10.1038/s41598-019-51385-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 09/06/2019] [Indexed: 11/09/2022] Open
Abstract
Nano-clusters are acclaimed to be very efficient absorbers of intense femto second light due to dominant collective mechanisms. Enhanced near 100% absorption due to collective linear plasma resonance compared to a small fraction of absorption by unclustered gas was an important drive in nano-plasma studies. Contrary to such perception, we show that if the pulse duration is (<100 fs), absorption is same irrespective of whether the systems are condensed to large clusters or not. So long as there are same number of similar ionizable systems in the focal volume, absorption is the same and such absorption can be accounted for by single particle response to the field and collisional ionization of atoms. Short pulse absorption by the single particle response can be comparable to the linear plasma resonance absorption for smaller clusters.
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Affiliation(s)
- Soubhik Sarkar
- Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai, 400 005, India
| | - R Gopal
- Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India
| | - M Anand
- Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India
| | - M Praveen Kumar
- Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India
| | - M Krishnamurthy
- Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai, 400 005, India. .,Tata Institute of Fundamental Research, Gopanpally, Hyderabad, 500 107, India.
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Mendy A, Gopal R, Alcorn JF, Forno E. Reduced mortality from lower respiratory tract disease in adult diabetic patients treated with metformin. Respirology 2019; 24:646-651. [PMID: 30761687 PMCID: PMC6579707 DOI: 10.1111/resp.13486] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 11/21/2018] [Accepted: 01/08/2019] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND OBJECTIVE Chronic lower respiratory diseases (CLRD) increase the risk of type 2 diabetes, which in turn may worsen lung function. Metformin, a common antidiabetic with anti-inflammatory and antioxidant properties, may improve respiratory outcomes. Therefore, we examined the association of metformin use with the risk of mortality from CLRD. METHODS We analysed data from the National Health and Nutrition Examination Survey during 1988-1994 and 1999-2010 for participants aged 40 years or older who had diabetes and were followed up for mortality through 2011. Information on prescription medicine was collected at baseline and CLRD-related mortality during follow-up was defined using the 10th Revision of the International Classification of Diseases (ICD-10). Cox proportional hazards modelling was used to determine the mortality hazard ratio (HR) associated with metformin use, adjusting for relevant covariates. RESULTS A total of 5266 participants with a median follow-up of 6.1 years were included. The prevalence of metformin use was 31.9% and 1869 participants died during follow-up, including 72 of CLRD. In the adjusted Cox proportional regression analysis, metformin was associated with a decreased risk of CLRD mortality in the overall population (HR: 0.39, 95% CI: 0.15-0.99) and among participants with baseline CLRD (HR: 0.30, 95% CI: 0.10-0.93), after adjusting for age, gender, race/ethnicity, cigarette smoking, body mass index, current asthma and chronic obstructive pulmonary disease (COPD), insulin and other diabetic medications, and glycohaemoglobin level. We found no association between other antidiabetic medications and CLRD mortality. CONCLUSION In this sample representative of the U.S. population, metformin was associated with lower CLRD mortality in adults with diabetes.
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Affiliation(s)
- Angelico Mendy
- College of Public Health, University of Iowa, Iowa City, IA
| | - Radha Gopal
- Division of Pulmonary Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - John F. Alcorn
- Division of Pulmonary Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Erick Forno
- Division of Pulmonary Medicine, Dept. of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Chandran P, Gopal R, Chandrasekar VK, Athavan N. Chimera states in coupled logistic maps with additional weak nonlocal topology. Chaos 2019; 29:053125. [PMID: 31154761 DOI: 10.1063/1.5084301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 05/01/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate the occurrence of coexisting domains of partially coherent and incoherent patterns or simply known as chimera states in a network of globally coupled logistic maps upon addition of weak nonlocal topology. We find that the chimera states survive even after we disconnect nonlocal connections of some of the nodes in the network. Also, we show that the chimera states exist when we introduce symmetric gaps in the nonlocal coupling between predetermined nodes. We ascertain our results, for the existence of chimera states, by carrying out the recurrence quantification analysis and by computing the strength of incoherence. We extend our analysis for the case of small-world networks of coupled logistic maps and found the emergence of chimeralike states under the influence of weak nonlocal topology.
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Affiliation(s)
- P Chandran
- Department of Physics, H.H. The Rajah's College, Pudukkottai 622 001, Tamil Nadu, India
| | - R Gopal
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, Tamil Nadu, India
| | - V K Chandrasekar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA Deemed University, Thanjavur 613 401, Tamil Nadu, India
| | - N Athavan
- Department of Physics, H.H. The Rajah's College, Pudukkottai 622 001, Tamil Nadu, India
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27
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Gopal R, Mendy A, Marinelli MA, Richwalls LJ, Seger PJ, Patel S, McHugh KJ, Rich HE, Grousd JA, Forno E, Alcorn JF. Peroxisome Proliferator-activated Receptor gamma (PPARγ) suppresses inflammation and bacterial control during influenza bacterial super-infection. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.66.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Influenza is one of the most common causes of respiratory illness worldwide and can be complicated by secondary bacterial pneumonia, which is a common cause of mortality. Influenza-induced “cytokine storm” is thought to play a role in lung pathogenesis during influenza infection. PPARγ is a member of nuclear hormone receptor superfamily that is known to enhance lipid and glucose metabolism, cellular differentiation and suppress the inflammatory immune response. Synthetic PPARγ agonists (thiazolidinedione, rosiglitazone) have been used clinically in the treatment of type II diabetes. In this study, we determined the effect of rosiglitazone in mice infected with influenza or influenza, methicillin-resistant Staphylococcus aureus (MRSA) super-infection. We found decreased influenza viral burden, decreased numbers of neutrophils and macrophages in bronchoalveolar lavage (BAL), and decreased production of IL-6, IL-12, CCL2, and CXCL10 in influenza-infected, rosiglitazone-treated mice when compared to influenza-infected control mice. However, rosiglitazone treatment compromised bacterial control during influenza-bacterial super-infection. Further, we found decreased numbers of neutrophils and decreased gene expression of neutrophil elastase and cathepsin G during super-infection in rosiglitazone-treated mice. Similarly, using data from the National Health and Nutrition Examination Survey (NHANES), we found increased influenza/pneumonia mortality in rosiglitazone-treated patients compared to other diabetic patients (adjusted hazard ratio=3.4, 95% confidence interval=1.1–10.7). Both human and mouse data suggest that rosiglitazone treatment worsens the outcome of influenza-associated pneumonia.
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Affiliation(s)
- Radha Gopal
- 1University of Pittsburgh, Department of Pediatrics, Pittsburgh, PA
| | - Angelico Mendy
- 2University of Iowa, College of Public Health, Division of Pulmonary Medicine, Iowa City, IA
| | | | | | - Philip J Seger
- 1University of Pittsburgh, Department of Pediatrics, Pittsburgh, PA
| | - Shivani Patel
- 1University of Pittsburgh, Department of Pediatrics, Pittsburgh, PA
| | - Kevin J McHugh
- 1University of Pittsburgh, Department of Pediatrics, Pittsburgh, PA
| | - Helen E Rich
- 1University of Pittsburgh, Department of Pediatrics, Pittsburgh, PA
| | | | - Erick Forno
- 1University of Pittsburgh, Department of Pediatrics, Pittsburgh, PA
| | - John F Alcorn
- 1University of Pittsburgh, Department of Pediatrics, Pittsburgh, PA
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Elumalai S, Kannan K, Gopal R, Sundararajan S. Clinical spectrum and treatment outcomes of HIV associated cancers in a tertiary care center in South India. Ann Oncol 2018. [DOI: 10.1093/annonc/mdy442.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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29
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Gopal R, Lee B, McHugh KJ, Rich HE, Ramanan K, Mandalapu S, Clay ME, Seger PJ, Enelow RI, Manni ML, Robinson KM, Rangel-Moreno J, Alcorn JF. STAT2 Signaling Regulates Macrophage Phenotype During Influenza and Bacterial Super-Infection. Front Immunol 2018; 9:2151. [PMID: 30337919 PMCID: PMC6178135 DOI: 10.3389/fimmu.2018.02151] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/31/2018] [Indexed: 01/14/2023] Open
Abstract
Influenza is a common respiratory virus that infects between 5 and 20% of the US population and results in 30,000 deaths annually. A primary cause of influenza-associated death is secondary bacterial pneumonia. We have previously shown that influenza induces type I interferon (IFN)-mediated inhibition of Type 17 immune responses, resulting in exacerbation of bacterial burden during influenza and Staphylococcus aureus super-infection. In this study, we investigated the role of STAT2 signaling during influenza and influenza-bacterial super-infection in mice. Influenza-infected STAT2−/− mice had increased morbidity, viral burden, and inflammation when compared to wild-type mice. Despite an exaggerated inflammatory response to influenza infection, we found increased bacterial control and survival in STAT2 deficient mice during influenza-MRSA super-infection compared to controls. Further, we found that increased bacterial clearance during influenza-MRSA super-infection is not due to rescue of Type 17 immunity. Absence of STAT2 was associated with increased accumulation of M1, M2 and M1/M2 co-expressing macrophages during influenza-bacterial super-infection. Neutralization of IFNγ (M1) and/or Arginase 1 (M2) impaired bacterial clearance in Stat2−/− mice during super-infection, demonstrating that pulmonary macrophages expressing a mixed M1/M2 phenotype promote bacterial control during influenza-bacterial super-infection. Together, these results suggest that the STAT2 signaling is involved in suppressing macrophage activation and bacterial control during influenza-bacterial super-infection. Further, these studies reveal novel mechanistic insight into the roles of macrophage subpopulations in pulmonary host defense.
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Affiliation(s)
- Radha Gopal
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Benjamin Lee
- Department of Pediatrics, University of Vermont College of Medicine, Burlington, VT, United States
| | - Kevin J McHugh
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Helen E Rich
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Krishnaveni Ramanan
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Sivanarayana Mandalapu
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Michelle E Clay
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Philip J Seger
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Richard I Enelow
- Department of Medicine, Dartmouth Medical School, Lebanon, PA, United States
| | - Michelle L Manni
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Keven M Robinson
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | - Javier Rangel-Moreno
- Division of Allergy, Immunology and Rheumatology, Department of Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - John F Alcorn
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
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30
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Gopal R, Sen A, Sahu SR, Venkatachalam AS, Anand M, Sharma V. Note: An ion imaging spectrometer for studying photo-induced fragmentation in small molecules. Rev Sci Instrum 2018; 89:086107. [PMID: 30184670 DOI: 10.1063/1.5049844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 08/02/2018] [Indexed: 06/08/2023]
Abstract
A three-dimensional ion imaging spectrometer has been designed and calibrated by ion trajectories simulations. We present a recipe for the verification of the calibration by obtaining kinetic energy (KE) distribution from the recorded flight times alone and consequently correlating the two KE spectra.
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Affiliation(s)
- R Gopal
- Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - A Sen
- Indian Institute of Science Education and Research, Pune 411008, India
| | - S R Sahu
- Indian Institute of Technology Hyderabad, Kandi 502285, India
| | | | - M Anand
- Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - V Sharma
- Indian Institute of Technology Hyderabad, Kandi 502285, India
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Abstract
A case of T-cell chronic lymphocytic leukemia (T-CLL) is reported. The surface receptor for sheep erythrocytes and acid phosphatase staining confirmed the diagnosis of T-CLL. This report provides evidence that T-CLL, a rare variant of CLL, is an aggressive disease with relative resistance to therapy and short survival.
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32
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Domingo-Gonzalez R, Das S, Griffiths KL, Ahmed M, Bambouskova M, Gopal R, Gondi S, Muñoz-Torrico M, Salazar-Lezama MA, Cruz-Lagunas A, Jiménez-Álvarez L, Ramirez-Martinez G, Espinosa-Soto R, Sultana T, Lyons-Weiler J, Reinhart TA, Arcos J, de la Luz Garcia-Hernandez M, Mastrangelo MA, Al-Hammadi N, Townsend R, Balada-Llasat JM, Torrelles JB, Kaplan G, Horne W, Kolls JK, Artyomov MN, Rangel-Moreno J, Zúñiga J, Khader SA. Interleukin-17 limits hypoxia-inducible factor 1α and development of hypoxic granulomas during tuberculosis. JCI Insight 2017; 2:92973. [PMID: 28978810 DOI: 10.1172/jci.insight.92973] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 08/31/2017] [Indexed: 12/24/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is a global health threat, compounded by the emergence of drug-resistant strains. A hallmark of pulmonary tuberculosis (TB) is the formation of hypoxic necrotic granulomas, which upon disintegration, release infectious Mtb. Furthermore, hypoxic necrotic granulomas are associated with increased disease severity and provide a niche for drug-resistant Mtb. However, the host immune responses that promote the development of hypoxic TB granulomas are not well described. Using a necrotic Mtb mouse model, we show that loss of Mtb virulence factors, such as phenolic glycolipids, decreases the production of the proinflammatory cytokine IL-17 (also referred to as IL-17A). IL-17 production negatively regulates the development of hypoxic TB granulomas by limiting the expression of the transcription factor hypoxia-inducible factor 1α (HIF1α). In human TB patients, HIF1α mRNA expression is increased. Through genotyping and association analyses in human samples, we identified a link between the single nucleotide polymorphism rs2275913 in the IL-17 promoter (-197G/G), which is associated with decreased IL-17 production upon stimulation with Mtb cell wall. Together, our data highlight a potentially novel role for IL-17 in limiting the development of hypoxic necrotic granulomas and reducing disease severity in TB.
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Affiliation(s)
| | | | | | | | - Monika Bambouskova
- Division of Immunobiology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Radha Gopal
- Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | | | - Marcela Muñoz-Torrico
- Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | | | - Alfredo Cruz-Lagunas
- Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Luis Jiménez-Álvarez
- Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | | | - Ramón Espinosa-Soto
- Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Tamanna Sultana
- Bioinformatics Analysis Core, Genomics and Proteomics Core Laboratories, and
| | - James Lyons-Weiler
- Bioinformatics Analysis Core, Genomics and Proteomics Core Laboratories, and
| | - Todd A Reinhart
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jesus Arcos
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
| | | | - Michael A Mastrangelo
- Cardiovascular Research Institute, Department of Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | | | - Reid Townsend
- Proteomics Shared Resource, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Jordi B Torrelles
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
| | - Gilla Kaplan
- Public Health Research Institute Center, New Jersey Medical School-Rutgers, State University of New Jersey, Newark, New Jersey, USA
| | - William Horne
- Richard King Mellon Institute for Pediatric Research, Department of Pediatrics and Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jay K Kolls
- Richard King Mellon Institute for Pediatric Research, Department of Pediatrics and Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Maxim N Artyomov
- Division of Immunobiology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Javier Rangel-Moreno
- Division of Allergy, Immunology and Rheumatology, Department of Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Joaquín Zúñiga
- Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
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33
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Lee B, Gopal R, Manni ML, McHugh KJ, Mandalapu S, Robinson KM, Alcorn JF. STAT1 Is Required for Suppression of Type 17 Immunity during Influenza and Bacterial Superinfection. Immunohorizons 2017; 1:81-91. [PMID: 29577113 DOI: 10.4049/immunohorizons.1700030] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Influenza is an annual, global health care concern. Secondary bacterial pneumonia is a severe complication associated with primary influenza virus infection, often resulting in critical morbidity and mortality. Our laboratory has identified influenza-induced suppression of anti-bacterial Type 17 immunity as a mechanism for enhanced susceptibility to bacterial super-infection. We have shown that influenza-induced type I interferon impairs Type 17 activation. STAT1 is a transcription factor involved in interferon signaling, shared by type I, II, and III interferon. In this work, we investigated the role of STAT1 signaling during influenza, methicillin-resistant Staphylococcus aureus (MRSA) super-infection. STAT1-/- mice had increased morbidity and airway inflammation compared to control mice during influenza mono-infection. Despite this worsened anti-viral response, STAT1-/- mice were protected from super-infection bacterial burden and mortality compared to controls. Type 17 immune activation was increased in lymphocytes in STAT1-/- mice during super-infection. The elevation in Type 17 immunity was not related to increased IL-23 production, as type I interferon could inhibit IL-23 expression in a STAT1 independent manner. STAT1-/- antigen presenting cells were inherently biased towards Type 17 polarization compared to control cells. Further, STAT1-/- dendritic cells produced attenuated IL-6 and TNFα upon heat-killed S. aureus stimulation compared to control. Overall, these data indicate that STAT1 signaling plays a detrimental role in influenza, MRSA super-infection by controlling the magnitude of Type 17 immune activation.
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Affiliation(s)
- Benjamin Lee
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA
| | - Radha Gopal
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA
| | - Michelle L Manni
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA
| | - Kevin J McHugh
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA
| | | | - Keven M Robinson
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - John F Alcorn
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA
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34
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Gopal R, Lee B, McHugh KJ, Rich HE, Ramanan K, Mandalapu S, Clay ME, Manni ML, Robinson KM, Rangel-Moreno J, Alcorn JF. STAT2-mediated regulation of Macrophage Phenotype during Influenza and Bacterial Super-infection. The Journal of Immunology 2017. [DOI: 10.4049/jimmunol.198.supp.153.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Influenza is a common contagious respiratory illness that affects people worldwide. Secondary bacterial infection is a major complication during influenza infection that causes significant morbidity and mortality. We have previously shown that influenza induces type I interferon (IFN)-mediated inhibition of Type17 immune responses, resulting in exacerbation of bacterial burden during influenza and Staphylococcus aureus super-infection in mice. Here, we investigated the role of the signaling mediator, STAT2, downstream of type I IFN signaling in both influenza infection and bacterial super-infection. Influenza-infected STAT2−/− mice had increased weight loss, increased viral burden, and increased inflammatory responses when compared to influenza-infected WT mice. Despite an exaggerated inflammatory response to influenza infection alone, influenza and methicillin resistant S. aureus (MRSA) super-infected STAT2−/− mice had lower bacterial burden, morbidity, and mortality than WT mice. STAT2−/− mice had an increased expression of markers associated with M1 (classical) and M2 (alternative) macrophages in lung during influenza or influenza-bacterial super infection compared to WT mice. Next, we found neutralization of IFNγ or Arginase1 decreased bacterial clearance in STAT2−/− mice in influenza-bacterial super-infection, suggesting that both M1 and M2 phenotype mediate host defense during influenza-bacterial super-infection. These data demonstrate a clear role for type I IFN induced STAT2 signaling in suppression of macrophage function during influenza, MRSA super-infection. Further, these studies reveal novel mechanistic insight into the roles of macrophage subpopulations in pulmonary host defense.
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35
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Bhardwaj AK, Shukla A, Mishra RK, Singh SC, Mishra V, Uttam KN, Singh MP, Sharma S, Gopal R. Power and Time Dependent Microwave Assisted Fabrication of Silver Nanoparticles Decorated Cotton (SNDC) Fibers for Bacterial Decontamination. Front Microbiol 2017; 8:330. [PMID: 28316594 PMCID: PMC5334347 DOI: 10.3389/fmicb.2017.00330] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/17/2017] [Indexed: 01/29/2023] Open
Abstract
Plasmonic nanoparticles (NPs) such as silver and gold have fascinating optical properties due to their enhanced optical sensitivity at a wavelength corresponding to their surface plasmon resonance (SPR) absorption. Present work deals with the fabrication of silver nanoparticles decorated cotton (SNDC) fibers as a cheap and efficient point of contact disinfectant. SNDC fibers were fabricated by a simple microwave assisted route. The microwave power and irradiation time were controlled to optimize size and density of silver nanoparticles (SNPs) on textile fibers. As prepared cotton fabric was characterized for ATR-FTIR, UV-VIS diffuse reflectance, SEM and TEM investigations. Size of SNPs as well as total density of silver atoms on fabric gets increased with the increase of microwave power from 100 W to 600 W. The antibacterial efficacy of SNPs extracted from SNDC fibers was found to be more effective against Gram-negative bacteria than Gram-positive bacteria with MIC 38.5 ± 0.93 μg/mL against Salmonella typhimurium MTCC-98 and 125 ± 2.12 μg/mL against Staphylococcus aureus MTCC-737, a linear correlation coefficient with R2 ranging from ∼0.928–0.935 was also observed. About >50% death cells were observed through Propidium Iodide (PI) internalization after treatment of SNPs extracted from SNDC fibers with concentration 31.25 μg/mL. Generation of ROS and free radical has also been observed which leads to cell death. Excellent Escherichia coli deactivation efficacy suggested that SNDC fibers could be used as potentially safe disinfectants for cleaning of medical equipment, hand, wound, water and preservation of food and beverages.
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Affiliation(s)
- Abhishek K Bhardwaj
- Centre for Environmental Science, University of AllahabadAllahabad, India; Laser Spectroscopy and Nanomaterials Lab., Department of Physics, University of AllahabadAllahabad, India
| | - Abhishek Shukla
- Laser Spectroscopy and Nanomaterials Lab., Department of Physics, University of Allahabad Allahabad, India
| | - Rohit K Mishra
- Centre for Medical Diagnostic and Research, Motilal Nehru National Institute of Technology Allahabad, India
| | - S C Singh
- Laser Spectroscopy and Nanomaterials Lab., Department of Physics, University of AllahabadAllahabad, India; High-Intensity Femtosecond Laser Laboratory, The Institute of Optics, University of RochesterRochester, NY, USA
| | - Vani Mishra
- Centre for Medical Diagnostic and Research, Motilal Nehru National Institute of Technology Allahabad, India
| | - K N Uttam
- Laser Spectroscopy and Nanomaterials Lab., Department of Physics, University of Allahabad Allahabad, India
| | - Mohan P Singh
- Centre of Biotechnology, University of Allahabad Allahabad, India
| | - Shivesh Sharma
- Centre for Medical Diagnostic and Research, Motilal Nehru National Institute of Technology Allahabad, India
| | - R Gopal
- Laser Spectroscopy and Nanomaterials Lab., Department of Physics, University of Allahabad Allahabad, India
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Gopal R, Kumar R, Anand M, Kulkarni A, Singh DP, Krishnan SR, Sharma V, Krishnamurthy M. A source to deliver mesoscopic particles for laser plasma studies. Rev Sci Instrum 2017; 88:023301. [PMID: 28249480 DOI: 10.1063/1.4974973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Intense ultrashort laser produced plasmas are a source for high brightness, short burst of X-rays, electrons, and high energy ions. Laser energy absorption and its disbursement strongly depend on the laser parameters and also on the initial size and shape of the target. The ability to change the shape, size, and material composition of the matter that absorbs light is of paramount importance not only from a fundamental physics point of view but also for potentially developing laser plasma sources tailored for specific applications. The idea of preparing mesoscopic particles of desired size/shape and suspending them in vacuum for laser plasma acceleration is a sparsely explored domain. In the following report we outline the development of a delivery mechanism of microparticles into an effusive jet in vacuum for laser plasma studies. We characterise the device in terms of particle density, particle size distribution, and duration of operation under conditions suitable for laser plasma studies. We also present the first results of x-ray emission from micro crystals of boric acid that extends to 100 keV even under relatively mild intensities of 1016 W/cm2.
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Affiliation(s)
- R Gopal
- Tata Institute of Fundamental Research, 21, Brundhavan Colony, Hyderabad 500075, India
| | - R Kumar
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Sangareddy 502285, India
| | - M Anand
- Tata Institute of Fundamental Research, 21, Brundhavan Colony, Hyderabad 500075, India
| | - A Kulkarni
- Tata Institute of Fundamental Research, 21, Brundhavan Colony, Hyderabad 500075, India
| | - D P Singh
- Tata Institute of Fundamental Research, 21, Brundhavan Colony, Hyderabad 500075, India
| | - S R Krishnan
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - V Sharma
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Sangareddy 502285, India
| | - M Krishnamurthy
- Tata Institute of Fundamental Research, 21, Brundhavan Colony, Hyderabad 500075, India
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Gopal R, Rapaka RR, Kolls JK. Immune reconstitution inflammatory syndrome associated with pulmonary pathogens. Eur Respir Rev 2017; 26:26/143/160042. [PMID: 28049128 PMCID: PMC5642276 DOI: 10.1183/16000617.0042-2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 06/09/2016] [Indexed: 12/21/2022] Open
Abstract
Immune reconstitution inflammatory syndrome (IRIS) is an exaggerated immune response to a variety of pathogens in response to antiretroviral therapy-mediated recovery of the immune system in HIV-infected patients. Although IRIS can occur in many organs, pulmonary IRIS, associated with opportunistic infections such as Mycobacterium tuberculosis and Pneumocystis jirovecii, is particularly associated with high morbidity and mortality. The pathology of IRIS is associated with a variety of innate and adaptive immune factors, including CD4+ T-cells, CD8+ T-cells, γδ T-cells, natural killer cells, macrophages, the complement system and surfactant proteins, Toll-like receptors and pro-inflammatory cytokines and chemokines. Although there are numerous reports about the immune factors involved in IRIS, the mechanisms involved in the development of pulmonary IRIS are poorly understood. Here, we propose that studies using gene-deficient murine and nonhuman primate models will help to identify the specific molecular targets associated with the development of IRIS. An improved understanding of the mechanisms involved in the pathology of pulmonary IRIS will help to identify potential biomarkers and therapeutic targets in this syndrome. Mechanisms of pulmonary IRIS in HIV-infected individuals recently initiated on ART are poorly definedhttp://ow.ly/AAOR301Bh36
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Affiliation(s)
- Radha Gopal
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
| | - Rekha R Rapaka
- Division of Infectious Diseases and Center for Vaccine Development, University of Maryland Medical Center, Baltimore, MD, USA
| | - Jay K Kolls
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
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Jana D, Gopal R, Lakshmanan M. Complex dynamics generated by negative and positive feedback delays of a prey–predator system with prey refuge: Hopf bifurcation to Chaos. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s40435-016-0267-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Chen K, Campfield BT, Wenzel SE, McAleer JP, Kreindler JL, Kurland G, Gopal R, Wang T, Chen W, Eddens T, Quinn KM, Myerburg MM, Horne WT, Lora JM, Albrecht BK, Pilewski JM, Kolls JK. Antiinflammatory effects of bromodomain and extraterminal domain inhibition in cystic fibrosis lung inflammation. JCI Insight 2016; 1. [PMID: 27517095 DOI: 10.1172/jci.insight.87168] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Significant morbidity in cystic fibrosis (CF) results from chronic lung inflammation, most commonly due to Pseudomonas aeruginosa infection. Recent data suggest that IL-17 contributes to pathological inflammation in the setting of abnormal mucosal immunity, and type 17 immunity-driven inflammatory responses may represent a target to block aberrant inflammation in CF. Indeed, transcriptomic analysis of the airway epithelium from CF patients undergoing clinical bronchoscopy revealed upregulation of IL-17 downstream signature genes, implicating a substantial contribution of IL-17-mediated immunity in CF lungs. Bromodomain and extraterminal domain (BET) chromatin modulators can regulate T cell responses, specifically Th17-mediated inflammation, by mechanisms that include bromodomain-dependent inhibition of acetylated histones at the IL17 locus. Here, we show that, in vitro, BET inhibition potently suppressed Th17 cell responses in explanted CF tissue and inhibited IL-17-driven chemokine production in human bronchial epithelial cells. In an acute P. aeruginosa lung infection murine model, BET inhibition decreased inflammation, without exacerbating infection, suggesting that BET inhibition may be a potential therapeutic target in patients with CF.
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Affiliation(s)
- Kong Chen
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
| | - Brian T Campfield
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA; University of Pittsburgh, Division of Pediatric Infectious Diseases, Department of Pediatrics, Pittsburgh, Pennsylvania, USA
| | - Sally E Wenzel
- University of Pittsburgh Asthma Institute at UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jeremy P McAleer
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
| | - James L Kreindler
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Geoffrey Kurland
- Division of Pediatric Pulmonology, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Radha Gopal
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
| | - Ting Wang
- Division of Pulmonary Medicine, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Wei Chen
- Division of Pulmonary Medicine, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Taylor Eddens
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
| | - Kathleen M Quinn
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
| | - Mike M Myerburg
- Division of Pulmonary, Allergy, and Critical Care Medicine, UPMC, Pittsburgh, Pennsylvania, USA
| | - William T Horne
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
| | - Jose M Lora
- Constellation Pharmaceuticals Inc., Cambridge, Massachusetts, USA
| | - Brian K Albrecht
- Constellation Pharmaceuticals Inc., Cambridge, Massachusetts, USA
| | - Joseph M Pilewski
- Division of Pulmonary, Allergy, and Critical Care Medicine, UPMC, Pittsburgh, Pennsylvania, USA
| | - Jay K Kolls
- Richard King Mellon Foundation Institute for Pediatric Research, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
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Chandrasekar VK, Gopal R, Senthilkumar DV, Lakshmanan M. Phase-flip chimera induced by environmental nonlocal coupling. Phys Rev E 2016; 94:012208. [PMID: 27575124 DOI: 10.1103/physreve.94.012208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Indexed: 06/06/2023]
Abstract
We report the emergence of a collective dynamical state, namely, the phase-flip chimera, from an ensemble of identical nonlinear oscillators that are coupled indirectly via the dynamical variables from a common environment, which in turn are nonlocally coupled. The phase-flip chimera is characterized by the coexistence of two adjacent out-of-phase synchronized coherent domains interspersed by an incoherent domain, in which the nearby oscillators are in out-of-phase synchronized states. Attractors of the coherent domains are either from the same or from different basins of attractions, depending on whether they are periodic or chaotic. The conventional chimera precedes the phase-flip chimera in general. Further, the phase-flip chimera emerges after the completely synchronized evolution of the ensemble, in contrast to conventional chimeras, which emerge as an intermediate state between completely incoherent and coherent states. We have also characterized the observed dynamical transitions using the strength of incoherence, probability distribution of the correlation coefficient, and framework of the master stability function.
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Affiliation(s)
- V K Chandrasekar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA University, Thanjavur 613 401, India
| | - R Gopal
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620 024, India
- Department of Physics, Nehru Memorial College, Puthanampatti, Tiruchirapalli 621 007, India
| | - D V Senthilkumar
- School of Physics, Indian Institute of Science Education and Research, Thiruvananthapuram 695 016, India
| | - M Lakshmanan
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620 024, India
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Monin L, Griffiths KL, Lam WY, Gopal R, Kang DD, Ahmed M, Rajamanickam A, Cruz-Lagunas A, Zúñiga J, Babu S, Kolls JK, Mitreva M, Rosa BA, Ramos-Payan R, Morrison TE, Murray PJ, Rangel-Moreno J, Pearce EJ, Khader SA. Helminth-induced arginase-1 exacerbates lung inflammation and disease severity in tuberculosis. J Clin Invest 2015; 125:4699-713. [PMID: 26571397 DOI: 10.1172/jci77378] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 10/08/2015] [Indexed: 01/06/2023] Open
Abstract
Parasitic helminth worms, such as Schistosoma mansoni, are endemic in regions with a high prevalence of tuberculosis (TB) among the population. Human studies suggest that helminth coinfections contribute to increased TB susceptibility and increased rates of TB reactivation. Prevailing models suggest that T helper type 2 (Th2) responses induced by helminth infection impair Th1 immune responses and thereby limit Mycobacterium tuberculosis (Mtb) control. Using a pulmonary mouse model of Mtb infection, we demonstrated that S. mansoni coinfection or immunization with S. mansoni egg antigens can reversibly impair Mtb-specific T cell responses without affecting macrophage-mediated Mtb control. Instead, S. mansoni infection resulted in accumulation of high arginase-1-expressing macrophages in the lung, which formed type 2 granulomas and exacerbated inflammation in Mtb-infected mice. Treatment of coinfected animals with an antihelminthic improved Mtb-specific Th1 responses and reduced disease severity. In a genetically diverse mouse population infected with Mtb, enhanced arginase-1 activity was associated with increased lung inflammation. Moreover, in patients with pulmonary TB, lung damage correlated with increased serum activity of arginase-1, which was elevated in TB patients coinfected with helminths. Together, our data indicate that helminth coinfection induces arginase-1-expressing type 2 granulomas, thereby increasing inflammation and TB disease severity. These results also provide insight into the mechanisms by which helminth coinfections drive increased susceptibility, disease progression, and severity in TB.
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Shukla A, Pandey BK, Singh SC, Uttam KN, Shah J, Kotnala RK, Kumar A, Gopal R. Liquid-Assisted Pulsed Laser Ablation Synthesis of Titanium Ferrite Nanomaterials. ACTA ACUST UNITED AC 2015. [DOI: 10.1166/mat.2015.1268] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Gopal R, Chandrasekar VK, Senthilkumar DV, Venkatesan A, Lakshmanan M. Effect of asymmetry parameter on the dynamical states of nonlocally coupled nonlinear oscillators. Phys Rev E Stat Nonlin Soft Matter Phys 2015; 91:062916. [PMID: 26172781 DOI: 10.1103/physreve.91.062916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Indexed: 06/04/2023]
Abstract
We show that coexisting domains of coherent and incoherent oscillations can be induced in an ensemble of any identical nonlinear dynamical systems using nonlocal rotational matrix coupling with an asymmetry parameter. Further, a chimera is shown to emerge in a wide range of the asymmetry parameter in contrast to near π/2 values of it employed in earlier works. We have also corroborated our results using the strength of incoherence in the frequency domain (S(ω)) and in the amplitude domain (S), thereby distinguishing the frequency and amplitude chimeras. The robust nature of the asymmetry parameter in inducing chimeras in any generic dynamical system is established using ensembles of identical Rössler oscillators, Lorenz systems, and Hindmarsh-Rose neurons in their chaotic regimes.
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Affiliation(s)
- R Gopal
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620 024, India
- Department of Physics, Nehru Memorial College, Puthanampatti, Tiruchirapalli 621 007, India
| | - V K Chandrasekar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA University, Thanjavur 613 401, India
| | - D V Senthilkumar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA University, Thanjavur 613 401, India
| | - A Venkatesan
- Department of Physics, Nehru Memorial College, Puthanampatti, Tiruchirapalli 621 007, India
| | - M Lakshmanan
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620 024, India
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Chandrasekar VK, Gopal R, Venkatesan A, Lakshmanan M. Mechanism for intensity-induced chimera states in globally coupled oscillators. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:062913. [PMID: 25615170 DOI: 10.1103/physreve.90.062913] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Indexed: 06/04/2023]
Abstract
We identify the mechanism behind the existence of intensity-induced chimera states in globally coupled oscillators. We find that the effect of intensity in the system is to cause multistability by increasing the number of fixed points. This in turn increases the number of multistable attractors, and we find that their stability is determined by the strength of coupling. This causes the coexistence of different collective states in the system depending upon the initial state. We demonstrate that intensity-induced chimera is generic to both periodic and chaotic systems. We discuss possible applications of our results to real-world systems like the brain and spin torque nano-oscillators.
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Affiliation(s)
- V K Chandrasekar
- Centre for Nonlinear Science & Engineering, School of Electrical & Electronics Engineering, SASTRA University, Thanjavur 613 401, India
| | - R Gopal
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620 024, India and Department of Physics, Nehru Memorial College, Puthanampatti, Tiruchirapalli 621 007, India
| | - A Venkatesan
- Department of Physics, Nehru Memorial College, Puthanampatti, Tiruchirapalli 621 007, India
| | - M Lakshmanan
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli 620 024, India
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Johnson SL, Gopal R, Enriquez A, Monroy FP. Role of glucocorticoids and Toxoplasma gondii infection on murine intestinal epithelial cells. Parasitol Int 2014; 63:687-94. [PMID: 24875937 DOI: 10.1016/j.parint.2014.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 02/24/2014] [Accepted: 05/05/2014] [Indexed: 02/06/2023]
Abstract
Glucocorticoids (GCs) are stress hormones secreted in response to perceived psychological and or physiological stress. GCs have been shown to reduce tissue inflammation by down-regulating the production of inflammatory chemokines produced by epithelial cells. The protozoan parasite Toxoplasma gondii is known to increase cytokine, chemokine, and Toll-like receptors (TLRs) expression in parasite infected mouse intestinal epithelial cells (IECs). We sought to analyze the role of an anti-inflammatory protein, glucocorticoid-induced leucine zipper (GILZ) in MODE-K cells during infection with T. gondii. GILZ expression in MODE-K cells was assessed by PCR and immunoblotting after stimulation with GCs (corticosterone, CORT) or T. gondii infection. GILZ mRNA was constitutively expressed in MODE-K cells but not its protein product. While infection and pre-exposure to CORT decreased GILZ isoforms of 28 and 17 kD, the presence of CORT during infection increased levels of 17 kD isoform. Infected cells treated with CORT had decreased expression of chemokines (IP-10/CXCL10, MCP-1/CCL2, MIP-2/CXCL8) while their expression was increased when endogenous GILZ was removed by siRNA treatment. GILZ up-regulation during infection may serve as a mechanism to decrease epithelial cell responses and facilitate parasite replication.
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Affiliation(s)
- Stacy L Johnson
- Department of Biological Sciences, Northern Arizona University, P.O. Box 5640, Flagstaff, AZ 86011, USA
| | - Radha Gopal
- Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center (UPMC), 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Amber Enriquez
- Department of Biological Sciences, Northern Arizona University, P.O. Box 5640, Flagstaff, AZ 86011, USA
| | - Fernando P Monroy
- Department of Biological Sciences, Northern Arizona University, P.O. Box 5640, Flagstaff, AZ 86011, USA.
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Pandey JK, Swarnkar RK, Soumya KK, Dwivedi P, Singh MK, Sundaram S, Gopal R. Silver nanoparticles synthesized by pulsed laser ablation: as a potent antibacterial agent for human enteropathogenic gram-positive and gram-negative bacterial strains. Appl Biochem Biotechnol 2014; 174:1021-31. [PMID: 24801405 DOI: 10.1007/s12010-014-0934-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/21/2014] [Indexed: 10/25/2022]
Abstract
Present investigation deals with the study, to quantify the antibacterial property of silver nanoparticles (SNPs), synthesized by pulsed laser ablation (PLA) in aqueous media, on some human enteropathogenic gram-positive and gram-negative bacterial strains. Antibacterial property was studied by measuring the zone of inhibition using agar cup double-diffusion method, minimum inhibitory concentration by serial dilution method, and growth curve for 24 h. The results clearly show the potency of antibacterial property of PLA-synthesized SNPs and suggest that it can be used as an effective growth inhibitor against various pathogenic bacterial strains in various medical devices and antibacterial control systems.
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Affiliation(s)
- Jitendra Kumar Pandey
- Laser Spectroscopy and Nanomaterials Lab, Department of Physics (UGC-CAS), University of Allahabad, Allahabad, 211002, India,
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Gopal R, Chandrasekar VK, Venkatesan A, Lakshmanan M. Observation and characterization of chimera states in coupled dynamical systems with nonlocal coupling. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 89:052914. [PMID: 25353868 DOI: 10.1103/physreve.89.052914] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Indexed: 06/04/2023]
Abstract
By developing the concepts of strength of incoherence and discontinuity measure, we show that a distinct quantitative characterization of chimera and multichimera states which occur in networks of coupled nonlinear dynamical systems admitting nonlocal interactions of finite radius can be made. These measures also clearly distinguish between chimera or multichimera states (both stable and breathing types) and coherent and incoherent as well as cluster states. The measures provide a straightforward and precise characterization of the various dynamical states in coupled chaotic dynamical systems irrespective of the complexity of the underlying attractors.
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Affiliation(s)
- R Gopal
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India
| | - V K Chandrasekar
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India
| | - A Venkatesan
- Department of Physics, Nehru Memorial College, Puthanampatti, Tiruchirapalli 621 007, India
| | - M Lakshmanan
- Centre for Nonlinear Dynamics, School of Physics, Bharathidasan University, Tiruchirapalli-620024, India
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Gopal V, Mangaiyarkarasi T, Gopal R. Fatal Klebsiella pneumoniae meningitis in a patient with diabetes mellitus and Hansen's disease. INDIAN J PATHOL MICR 2014; 57:139-40. [PMID: 24739855 DOI: 10.4103/0377-4929.130927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Klebsiella is a Gram-negative bacterium that causes different types of health care-associated infections including pneumonia, bloodstream infections, surgical site infections and meningitis. We report here a case of Klebsiella pneumoniae meningitis in a patient with diabetes mellitus and Hansen's disease. A middle-aged man with a known case of diabetes mellitus and Hansen's disease presented with the complaints of blurred vision in the left eye and the patient was found to have cataract. Patient was operated for cataract and Intraocular lens implanted. Patient developed headache and vomiting on the 4th post-operative day. Lumbar puncture was carried out and gram stain of cerebrospinal fluid showed Gram-negative bacilli in the direct smear and culture yielded a heavy growth of K. pneumoniae. The patient was treated with antimicrobials according to the susceptibility pattern. He initially showed improvement but later on developed altered sensorium and hypotension. Patient succumbed to infection in spite of all medical attention.
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Affiliation(s)
| | | | - R Gopal
- Department of Microbiology, Sri Manakula Vinayagar Medical College & Hospital, Puducherry, India
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Krishnan SR, Gopal R, Rajeev R, Jha J, Sharma V, Mudrich M, Moshammer R, Krishnamurthy M. Photoionization of clusters in intense few-cycle near infrared femtosecond pulses. Phys Chem Chem Phys 2014; 16:8721-30. [DOI: 10.1039/c3cp55380a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In this article we present a perspective on the current state of the art in the photoionization of atomic clusters in few-cycle near-infrared laser pulses.
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Affiliation(s)
- S. R. Krishnan
- Tata Institute of Fundamental Research (Hyderabad)
- Hyderabad 50075, India
| | - R. Gopal
- Tata Institute of Fundamental Research (Hyderabad)
- Hyderabad 50075, India
| | - R. Rajeev
- Tata Institute of Fundamental Research
- Mumbai 400001, India
| | - J. Jha
- Tata Institute of Fundamental Research
- Mumbai 400001, India
| | - V. Sharma
- Indian Institute of Technology – Hyderabad
- Hyderabad 502205, India
| | - M. Mudrich
- Physikalisches Institut, Universität Freiburg
- 79104 Freiburg, Germany
| | - R. Moshammer
- Max-Planck-Institut für Kernphysik
- D-69117 Heidelberg, Germany
| | - M. Krishnamurthy
- Tata Institute of Fundamental Research (Hyderabad)
- Hyderabad 50075, India
- Tata Institute of Fundamental Research
- Mumbai 400001, India
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Gopal R, Monin L, Torres D, Slight S, Mehra S, McKenna KC, Fallert Junecko BA, Reinhart TA, Kolls J, Báez-Saldaña R, Cruz-Lagunas A, Rodríguez-Reyna TS, Kumar NP, Tessier P, Roth J, Selman M, Becerril-Villanueva E, Baquera-Heredia J, Cumming B, Kasprowicz VO, Steyn AJC, Babu S, Kaushal D, Zúñiga J, Vogl T, Rangel-Moreno J, Khader SA. S100A8/A9 proteins mediate neutrophilic inflammation and lung pathology during tuberculosis. Am J Respir Crit Care Med 2013; 188:1137-46. [PMID: 24047412 DOI: 10.1164/rccm.201304-0803oc] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
RATIONALE A hallmark of pulmonary tuberculosis (TB) is the formation of granulomas. However, the immune factors that drive the formation of a protective granuloma during latent TB, and the factors that drive the formation of inflammatory granulomas during active TB, are not well defined. OBJECTIVES The objective of this study was to identify the underlying immune mechanisms involved in formation of inflammatory granulomas seen during active TB. METHODS The immune mediators involved in inflammatory granuloma formation during TB were assessed using human samples and experimental models of Mycobacterium tuberculosis infection, using molecular and immunologic techniques. MEASUREMENTS AND MAIN RESULTS We demonstrate that in human patients with active TB and in nonhuman primate models of M. tuberculosis infection, neutrophils producing S100 proteins are dominant within the inflammatory lung granulomas seen during active TB. Using the mouse model of TB, we demonstrate that the exacerbated lung inflammation seen as a result of neutrophilic accumulation is dependent on S100A8/A9 proteins. S100A8/A9 proteins promote neutrophil accumulation by inducing production of proinflammatory chemokines and cytokines, and influencing leukocyte trafficking. Importantly, serum levels of S100A8/A9 proteins along with neutrophil-associated chemokines, such as keratinocyte chemoattractant, can be used as potential surrogate biomarkers to assess lung inflammation and disease severity in human TB. CONCLUSIONS Our results thus show a major pathologic role for S100A8/A9 proteins in mediating neutrophil accumulation and inflammation associated with TB. Thus, targeting specific molecules, such as S100A8/A9 proteins, has the potential to decrease lung tissue damage without impacting protective immunity against TB.
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Affiliation(s)
- Radha Gopal
- 1 Division of Infectious Diseases, Department of Pediatrics, and
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