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Jaswani P, Prakash S, Dhar A, Sharma RK, Prasad N, Agrawal S. MicroRNAs Involvement in Renal Pathophysiology: A Bird's Eye View. Indian J Nephrol 2017; 27:337-341. [PMID: 28904427 PMCID: PMC5590408 DOI: 10.4103/ijn.ijn_264_16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
MicroRNAs (miRNAs) are known to suppress gene expression by binding to messenger RNAs and in turn regulate different pathophysiological processes. Transforming growth factor-β, mitogen-activated protein kinase signaling, and Wnt signaling-like major pathways associated with miRNAs are involved with kidney diseases. The discovery of miRNAs has provided new insights into kidney pathologies and may provide effective therapeutic strategies. Research has demonstrated the role of miRNAs in a variety of kidney diseases including diabetic nephropathy, lupus nephritis, hypertension, nephritic syndrome, acute kidney injury, renal cell carcinoma, and renal fibrosis. miRNAs are implicated as playing a role in these diseases due to their role in apoptosis, cell proliferation, differentiation, and development. As miRNAs have been detected in a stable condition in different biological fluids, they have the potential to be tools to study the pathogenesis of human diseases with a great potential to be used in disease diagnosis and prognosis. The purpose of this review is to examine the role of miRNA in kidney disease.
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Moreno V, Bauer T, Infante J, Govindan R, Besse B, Bertino E, Marti AM, Piontek T, Dhar A. A phase I, open-label, study of GSK2879552, a lysine-specific demethylase 1 (LSD1) inhibitor, in patients with relapsed/refractory small cell lung carcinoma (SCLC). Ann Oncol 2016. [DOI: 10.1093/annonc/mdw368.24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Kumar S, Dhar A. Accelerated Thermal-Aging-Induced Degradation of Organometal Triiodide Perovskite on ZnO Nanostructures and Its Effect on Hybrid Photovoltaic Devices. ACS APPLIED MATERIALS & INTERFACES 2016; 8:18309-18320. [PMID: 27351932 DOI: 10.1021/acsami.6b06878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Organometal halide perovskite materials are presently some of the pacesetters for light harvesting in hybrid photovoltaic devices because of their excellent inherent electrical and optical properties. However, long-term durability of such perovskite materials remains a major bottleneck for their commercialization especially in countries with hot and humid climatic conditions, thus violating the international standards for photovoltaic technology. Albeit, TiO2 as an electron-transport layer has been well investigated for perovskite solar cells; the high-temperature processing makes it unsuitable for low-cost and large-scale roll-to-roll production of flexible photovoltaic devices. Herein, we have chosen low-temperature (<150 °C)-processable nanostructured ZnO as the electron-selective layer and used a two-step method for sensitizing ZnO nanorods with methylammonium lead iodide (MAPbI3) perovskite, which is viable for flexible photovoltaic devices. We have also elaborately addressed the effect of the annealing duration on the conversion of a precursor solution into the required perovskite phase on ZnO nanostructures. The investigations show that the presence of ZnO nanostructures accelerates the rate of degradation of MAPbI3 films under ambient annealing and thus requires proper optimization. The role of ZnO in enhancing the degradation kinetics of the perovskite layer has been investigated by X-ray photoelectron spectroscopy and a buffer layer passivation technique. The effect of the annealing duration of the MAPbI3 perovskite on the optical, morphological, and compositional behavior has been closely studied and correlated with the photovoltaic efficiency. The study captures the degradation behavior of the commercially interesting MAPbI3 perovskite on a ZnO electron-transport layer and thus can provide insight for developing alternative families of perovskite material with better thermal and environmental stability for application in low-cost flexible photovoltaic technology.
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Dhar A, Liao L, Liem J, Sidhu A, Kassum S. Oral Food Challenges: A Retrospective Review of A Canadian Paediatric Allergy Clinic. Paediatr Child Health 2016. [DOI: 10.1093/pch/21.supp5.e62a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
BACKGROUND: Food allergies in children can be life threatening and require prompt treatment with epinephrine. The gold standard for food allergy diagnosis is an Oral Food Challenge (OFC).
OBJECTIVES: To demonstrate the safety of OFCs for diagnosing and monitoring food allergies in a Canadian community paediatric population.
DESIGN/METHODS: Retrospective review of 500 paediatric patients that underwent 684 OFCs to a variety of foods from November 2006 to December 2013. Data collected from the patients includes demographics; the food challenged; reasons for the OFC; reactions experienced during the OFC; medical intervention performed; and whether the patient should continue eating the food challenged (OFC success). Anaphylaxis was defined using the World Allergy Organization criteria – i.e. dermatologic and cardiovascular or respiratory involvement after food ingestion; or two of dermatologic, cardiovascular, respiratory or gastrointestinal involvement after a likely allergen; or cardiovascular involvement after a known allergen. Mild reactions involved only 1 non-cardiovascular system; and moderate reactions involved more than 1 non-cardiovascular system, but did not qualify as anaphylaxis. Systems observed included the dermatologic, upper and lower respiratory, gastrointestinal, cardiovascular, and behavioural systems.
RESULTS: Of the 684 OFCs performed, there were 584 OFCs (85.4%) where the patients were successful at eating the food. Reactions occurred in 274 of 684 OFCs (40.1%), including 161 mild reactions (58.8% of reactions), 56 moderate reactions (20.4% of reactions), and 57 anaphylactic reactions (20.8% of reactions). Medical intervention was required in 74 OFCs (27.0% of reactions). All OFCs with no reaction were successful and all OFCs with anaphylaxis were not successful. OFCs with mild and moderate reactions had equivalent odds of being successful (OR [95% CI] = 0.01 [0.0003, 0.08] and 0.006 [0.0001, 0.04], respectively). Most reactions occurred within six hours of exposure to the food (267 of 274 reactions; 97.4%). The most common foods challenged were peanuts, eggs, and cow’s milk. The reasons for the OFCs were to diagnose an allergy (49.7%), monitor outgrowth of a diagnosed allergy (43.7%), or due to a family member having an allergy (6.6%).
CONCLUSION: In this community practice setting, patients undergoing an OFC were able to eat the food afterwards in 85.4% of the cases. Reactions occurred in 40.1% of OFCs. Anaphylaxis occurred in 8.3% of OFCs (57 of 684 OFCs). Most patients reacted within six hours of exposure. The majority of patients undergoing OFCs did not require treatment. OFCs provide a safe environment to diagnose and monitor food allergies in children.
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Mishra S, Swati G, Rajesh B, Tyagi K, Gahtori B, Sivaiah B, Vijayan N, Dalai MK, Dhar A, Auluck S, Jayasimhadri M, Haranath D. Luminescence and advanced mass spectroscopic characterization of sodium zinc orthophosphate phosphor for low-cost light-emitting diodes. LUMINESCENCE 2015. [PMID: 26198805 DOI: 10.1002/bio.2966] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A new rare-earth-free NaZnPO4:Mn(2+) (NZP:Mn) phosphor powder has been developed by our group and investigated meticulously for the first time using secondary ion mass spectroscopy and chemical imaging techniques. The studies confirmed the effective incorporation of Mn(2+) into the host lattice, resulting in an enhancement of photoluminescence intensity. Phase purity has been verified and structure parameters have been determined successfully by Rietveld refinement studies. The NZP:Mn phosphor powder exhibits strong absorption bands in the ultraviolet and visible (300-470 nm) regions with a significant broad yellow-green (~543 nm) emission due to the characteristic spin forbidden d-d transition ((4)T1→(6)A1) of Mn(2+) ions, indicating weak crystal field strength at the zinc-replaced manganese site. The decay constants are a few milliseconds, which is a pre-requisite for applications in many display devices. The results obtained suggest that this new phosphor powder will find many interesting applications in semiconductor physics, as cost-effective light-emitting diodes (LEDs), as solar cells and in photo-physics.
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Mullish BH, Kabir MS, Thursz MR, Dhar A. Letter: depression and the use of anti-depressants in patients with chronic liver disease or liver transplantation - authors' reply. Aliment Pharmacol Ther 2015; 41:914-5. [PMID: 25846393 DOI: 10.1111/apt.13146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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Dhar A. Targeting BET bromo domain and other epigenetic modifiers for treatment of cancer. Ann Oncol 2015. [DOI: 10.1093/annonc/mdv085.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Panda D, Dhar A, Ray SK. Diffusion kinetics and evolution of self-assembled nickel germanide nanorings on germanised Si (100). RSC Adv 2015. [DOI: 10.1039/c5ra00869g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Self assembled binary nickel germanide nanorings are formed by annealing of a Ni/Ge/Si (100) film.
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Mullish BH, Kabir MS, Thursz MR, Dhar A. Review article: depression and the use of antidepressants in patients with chronic liver disease or liver transplantation. Aliment Pharmacol Ther 2014; 40:880-92. [PMID: 25175904 DOI: 10.1111/apt.12925] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 07/14/2014] [Accepted: 07/28/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND The scale of depression in patients with chronic liver disease (CLD) and those who have received orthotopic liver transplantation (OLT) is poorly characterised. Clinicians are uncertain of how best to manage depression within these patients. AIMS To review the literature evaluating both the prevalence and impact of depression in patients with CLD and post-OLT, and to assess the safety and efficacy of antidepressant use within this context. METHODS A PubMed search using the phrases 'chronic liver disease', 'cirrhosis', 'liver transplantation', 'depression', 'antidepressant' and the names of specific causes of liver disease and individual antidepressants. RESULTS Over 30% of cirrhotic patients have depressive features, and they experience worse clinical outcomes than nondepressed cirrhotic patients. CLD patients with chronic hepatitis C are particularly prone to depression, partly related to the use of interferon therapy. OLT patients with depression have higher mortality rates than nondepressed patients; appropriate antidepressant use reverses this effect. Selective serotonin reuptake inhibitors (SSRIs) and selective noradrenaline reuptake inhibitors (SNRIs) are effective and generally safe in both CLD and OLT patients. CONCLUSIONS Depression is much more prevalent in CLD or OLT patients than is generally recognised, and it adversely affects clinical outcomes. The reasons for this relationship are complex and multifactorial. Antidepressants are effective in both CLD and post-OLT, although lower doses or a reduced dosing frequency may be required to minimise side effects, e.g. exacerbation of hepatic encephalopathy. Further research is needed to establish optimal management of depression in these patients, including the potential role of nonpharmacological treatments.
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Challa VR, Srivastava A, Dhar A. Scrofulous swelling of the bosom masquerading as cancer. Indian J Med Microbiol 2014; 32:82-4. [PMID: 24399398 DOI: 10.4103/0255-0857.124331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Tuberculosis of breast is very rare with an incidence of 0.1-0.5%. It can be primary or secondary. Except in patients presenting with sinuses, it is a challenge to diagnose it. A 40 year old premenopausal lady presented with breast lump increasing in size for 3 months. Mammogram showed a lesion suspicious of malignancy and trucut biopsy showed necrotic material only. Intraoperatively there was caseous necrosis and the tract from breast was extending to rib. It is a rare case with few case reports been reported where a rib tuberculosis presents as a breast lump rather than retromammary abscess.
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Allen SJ, Wareham K, Wang D, Bradley C, Sewell B, Hutchings H, Harris W, Dhar A, Brown H, Foden A, Gravenor MB, Mack D, Phillips CJ. A high-dose preparation of lactobacilli and bifidobacteria in the prevention of antibiotic-associated and Clostridium difficile diarrhoea in older people admitted to hospital: a multicentre, randomised, double-blind, placebo-controlled, parallel arm trial (PLACIDE). Health Technol Assess 2014; 17:1-140. [PMID: 24309198 DOI: 10.3310/hta17570] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Antibiotic-associated diarrhoea (AAD) occurs most commonly in older people admitted to hospital and within 12 weeks of exposure to broad-spectrum antibiotics. Although usually a mild and self-limiting illness, the 15-39% of cases caused by Clostridium difficile infection [C. difficile diarrhoea (CDD)] may result in severe diarrhoea and death. Previous research has shown that probiotics, live microbial organisms that, when administered in adequate numbers, are beneficial to health, may be effective in preventing AAD and CDD. OBJECTIVES To determine the clinical effectiveness and cost-effectiveness of a high-dose, multistrain probiotic in the prevention of AAD and CDD in older people admitted to hospital. DESIGN A multicentre, randomised, double-blind, placebo-controlled, parallel-arm trial. SETTING Medical, surgical and elderly care inpatient wards in five NHS hospitals in the UK. PARTICIPANTS Eligible patients were aged ≥ 65 years, were exposed to one or more oral or parenteral antibiotics and were without pre-existing diarrhoeal disorders, recent CDD or at risk of probiotic adverse effects. Out of 17,420 patients screened, 2981 (17.1%) were recruited. Participants were allocated sequentially according to a computer-generated random allocation sequence; 1493 (50.1%) were allocated to the probiotic and 1488 (49.9%) to the placebo arm. INTERVENTIONS Vegetarian capsules containing two strains of lactobacilli and two strains of bifidobacteria (a total of 6 × 10(10) organisms per day) were taken daily for 21 days. The placebo was inert maltodextrin powder in identical capsules. MAIN OUTCOME MEASURES The occurrence of AAD within 8 weeks and CDD within 12 weeks of recruitment was determined by participant follow-up and checking hospital laboratory records by research nurses who were blind to arm allocation. RESULTS Analysis based on the treatment allocated included 2941 (98.7%) participants. Potential risk factors for AAD at baseline were similar in the two study arms. Frequency of AAD (including CDD) was similar in the probiotic (159/1470, 10.8%) and placebo arms [153/1471, 10.4%; relative risk (RR) 1.04; 95% confidence interval (CI) 0.84 to 1.28; p = 0.71]. CDD was an uncommon cause of AAD and occurred in 12/1470 (0.8%) participants in the probiotic and 17/1471 (1.2%) in the placebo arm (RR 0.71; 95% CI 0.34 to 1.47; p = 0.35). Duration and severity of diarrhoea, common gastrointestinal symptoms, serious adverse events and quality of life measures were also similar in the two arms. Total health-care costs per patient did not differ significantly between the probiotic (£8020; 95% CI £7620 to £8420) and placebo (£8010; 95% CI £7600 to £8420) arms. CONCLUSION We found no evidence that probiotic administration was effective in preventing AAD. Although there was a trend towards reduced CDD in the probiotic arm, on balance, the administration of this probiotic seems unlikely to benefit older patients exposed to antibiotics. A better understanding of the pathogenesis of AAD and CDD and the strain-specific effects of probiotics is needed before further clinical trials of specific microbial preparations are undertaken. Evaluation of the effectiveness of other probiotics will be difficult where other measures, such as antibiotic stewardship, have reduced CDD rates. TRIAL REGISTRATION This trial is registered as ISRCTN70017204. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 57. See the NIHR Journals Library website for further project information.
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Hemmert C, Ohana M, Jeung MY, Labani A, Dhar A, Kessler R, Roy C. Imaging of lung transplant complications. Diagn Interv Imaging 2014; 95:399-409. [DOI: 10.1016/j.diii.2013.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Papastergiou V, Tsochatzis EA, Pieri G, Thalassinos E, Dhar A, Bruno S, Karatapanis S, Luong TV, O'Beirne J, Patch D, Thorburn D, Burroughs AK. Nine scoring models for short-term mortality in alcoholic hepatitis: cross-validation in a biopsy-proven cohort. Aliment Pharmacol Ther 2014; 39:721-32. [PMID: 24612165 PMCID: PMC4015369 DOI: 10.1111/apt.12654] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 01/08/2014] [Accepted: 01/20/2014] [Indexed: 12/14/2022]
Abstract
BACKGROUND Several prognostic models have emerged in alcoholic hepatitis (AH), but lack of external validation precludes their universal use. AIM To validate the Maddrey Discriminant Function (DF); Glasgow Alcoholic Hepatitis Score (GAHS); Mayo End-stage Liver Disease (MELD); Age, Bilirubin, INR, Creatinine (ABIC); MELD-Na, UK End-stage Liver Disease (UKELD), and three scores of corticosteroid response at 1 week: an Early Change in Bilirubin Levels (ECBL), a 25% fall in bilirubin, and the Lille score. METHODS Seventy-one consecutive patients with biopsy-proven AH, admitted between November 2007-September 2011, were evaluated. The clinical and biochemical parameters were analysed to assess prognostic models with respect to 30- and 90-day mortality. RESULTS There were no significant differences in the areas under the receiver operating characteristics curve (AUROCs) relative to 30-day/90-day mortality: MELD 0.79/0.84, DF 0.71/0.74, GAHS 0.75/0.78, ABIC 0.71/0.78, MELD-Na 0.68/0.76, UKELD 0.56/0.68. One-week rescoring yielded a trend towards improved predictive accuracies (30-day/90-day AUROCs: 0.69–0.84/0.77–0.86). In patients with admission DF ≥ 32 (n = 31), response to corticosteroids according to ECBL, 25% fall in bilirubin and the Lille model yielded AUROCs of 0.73/0.73, 0.78/0.72 and 0.81/0.82 for a 30-day/90-day outcome respectively. All models showed excellent negative predictive values (NPVs; range: 86–100%), while the positive ones were low (range: 17–50%). CONCLUSIONS MELD, DF, GAHS, ABIC and scores of corticosteroid response proved to be valid in an independent cohort of biopsy-proven alcoholic hepatitis. MELD modifications incorporating sodium did not confer any prognostic advantage over classical MELD. Based on excellent NPVs, the models are best to identify patients at low risk of death.
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Gupta P, Chullikana A, Rajkumar M, Krishna M, Dutta S, Sarkar U, Desai S, Radhakrishnan R, Dhar A, Balasubramanian S, Kumar U, Baikunje U, Prasanth K, Anthony N, Majumdar A. Role of bone marrow derived allogeneic mesenchymal stromal cells (stempeucel ®) in critical limb ischemia due to buerger's disease – efficacy and safety results of non-randomized, open label, multicentric, dose ranging, phase ii study in India. Cytotherapy 2014. [DOI: 10.1016/j.jcyt.2014.01.295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Xu D, Haranath D, He H, Mishra S, Bharti I, Yadav D, Sivaiah B, Gahtori B, Vijayan N, Dhar A, Zhu J, Shanker V, Pandey R. Studies on phase stability, mechanical, optical and electronic properties of a new Gd2CaZnO5 phosphor system for LEDs. CrystEngComm 2014. [DOI: 10.1039/c3ce42194e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Srivastava A, Adimulam G, Challa VR, Dhar A, Chumber S, Seenu V. Assessment of cosmetic outcome of oncoplastic breast conservation surgery in women with early breast cancer: A prospective cohort study. Indian J Cancer 2014; 51:58-62. [DOI: 10.4103/0019-509x.134629] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Jung Y, Kang Q, Sleiffer VAJM, Inan B, Kuschnerov M, Veljanovski V, Corbett B, Winfield R, Li Z, Teh PS, Dhar A, Sahu J, Poletti F, Alam SU, Richardson DJ. Three mode Er3+ ring-doped fiber amplifier for mode-division multiplexed transmission. OPTICS EXPRESS 2013; 21:10383-10392. [PMID: 23609749 DOI: 10.1364/oe.21.010383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We successfully fabricate three-mode erbium doped fiber with a confined Er(3+) doped ring structure and experimentally characterize the amplifier performance with a view to mode-division multiplexed (MDM) transmission. The differential modal gain was effectively mitigated by controlling the relative thickness of the ring-doped layer in the active fiber and pump launch conditions. A detailed study of the modal gain properties, amplifier performance in a MDM transmission system and inter-modal cross-gain modulation and associated transient effects is presented.
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Jain S, May-Smith TC, Dhar A, Webb AS, Belal M, Richardson DJ, Sahu JK, Payne DN. Erbium-doped multi-element fiber amplifiers for space-division multiplexing operations. OPTICS LETTERS 2013; 38:582-584. [PMID: 23455143 DOI: 10.1364/ol.38.000582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Erbium-doped multi-element fiber (MEF) amplifiers have been fabricated to simultaneously amplify multiple transmission channels. MEF devices comprise of multiple single-core fibers (elements) combined in a common coating, with each element working as a single fiber in isolation. MEFs containing 3-elements and 7-elements have been fabricated and characterized. Each element of the fabricated MEFs provides nearly 32 dB of gain with a noise figure of <5 dB for an input signal level of -23 dBm at 1530 nm. Different permutations of element pairs within the MEFs were checked for crosstalk and none was detected, confirming the simultaneous multi-channel amplification capabilities of MEFs.
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Bhardwaj A, Rajput A, Shukla AK, Pulikkotil JJ, Srivastava AK, Dhar A, Gupta G, Auluck S, Misra DK, Budhani RC. Mg3Sb2-based Zintl compound: a non-toxic, inexpensive and abundant thermoelectric material for power generation. RSC Adv 2013. [DOI: 10.1039/c3ra40457a] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Sleiffer VAJM, Jung Y, Veljanovski V, van Uden RGH, Kuschnerov M, Chen H, Inan B, Nielsen LG, Sun Y, Richardson DJ, Alam SU, Poletti F, Sahu JK, Dhar A, Koonen AMJ, Corbett B, Winfield R, Ellis AD, de Waardt H. 73.7 Tb/s (96 x 3 x 256-Gb/s) mode-division-multiplexed DP-16QAM transmission with inline MM-EDFA. OPTICS EXPRESS 2012; 20:B428-B438. [PMID: 23262884 DOI: 10.1364/oe.20.00b428] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Transmission of a 73.7 Tb/s (96 x 3 x 256-Gb/s) DP-16QAM mode-division-multiplexed signal over 119 km of few-mode fiber transmission line incorporating an inline multi mode EDFA and a phase plate based mode (de-)multiplexer is demonstrated. Data-aided 6 x 6 MIMO digital signal processing was used to demodulate the signal. The total demonstrated net capacity, taking into account 20% of FEC-overhead and 7.5% additional overhead (Ethernet and training sequences), is 57.6 Tb/s, corresponding to a spectral efficiency of 12 bits/s/Hz.
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Gupta K, Bhattacharya S, Nandi D, Dhar A, Maity A, Mukhopadhyay A, Chattopadhyay DJ, Ray NR, Sen P, Ghosh UC. Arsenic(III) sorption on nanostructured cerium incorporated manganese oxide (NCMO): a physical insight into the mechanistic pathway. J Colloid Interface Sci 2012; 377:269-76. [PMID: 22515993 DOI: 10.1016/j.jcis.2012.01.066] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 12/24/2011] [Accepted: 01/09/2012] [Indexed: 11/18/2022]
Abstract
Arsenic(III) sorption was investigated with nanostructured cerium incorporated manganese oxide (NCMO). The pH between 6.0 and 8.0 was optimized for the arsenic(III) sorption. Kinetics and equilibrium data (pH=7.0±0.2, T=303±1.6 K, and I=0.01 M) of arsenic(III) sorption by NCMO described, respectively, the pseudo-second order and the Freundlich isotherm equations well. The sorption process was somewhat complicated in nature and divided into two different segments, initially very fast sorption followed by slow intraparticle diffusion process. Sorption reaction of arsenic(III) on NCMO was endothermic (ΔH°=+13.46 kJ mol(-1)) and spontaneous (ΔG°=-24.75 to -30.15 kJ mol(-1) at T=283-323 K), which took place with increasing entropy (ΔS°=+0.14 kJ mol(-1)K(-1)) at solid-liquid interface. Energy of arsenic(III) sorption estimated by analyzing the equilibrium data using the D-R isotherm model was 15.4 kJ mol(-1), indicating the ion-exchange type mechanism. Raman, FT-IR, pH effect, desorption, etc. studies indicated that arsenic(III) was oxidized to arsenic(V) during the sorption process.
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Tedd HM, Tuckett J, Arun C, Dhar A. An unusual case of sudden onset headache due to pituitary apoplexy: a case report and review of the new UK guidelines. J R Coll Physicians Edinb 2012; 42:119-23. [DOI: 10.4997/jrcpe.2012.206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Rakshit T, Mandal S, Mishra P, Dhar A, Manna I, Ray SK. Optical and bio-sensing characteristics of ZnO nanotubes grown by hydrothermal method. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2012; 12:308-315. [PMID: 22523980 DOI: 10.1166/jnn.2012.5134] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
ZnO nanostructures were fabricated on copper substrates by hydrothermal method at an optimized growth temperature of -95 degrees C. Structural properties were investigated by field emission scanning electron and transmission electron microscopy. Distinct morphologies were found to be formed at different growth times. The formation of nanotubes mainly involved the initial nucleation followed by the growth of nanorods at 95 degrees C, and then with the increase of dissolution time at room temperature, the preferential chemical dissolution of the metastable Zn-rich [0001] polar surfaces resulted in removing the atoms from the surfaces, thus leading to the thinning of the wall of the nanostructures. Completely hollow ZnO nanotubes could be obtained at a high dissolution time. The room temperature photoluminescence and optical absorption properties of ZnO nanotubes have been studied as a function of dissolution time. The efficacy of ZnO nanotubes for glucose sensing applications has been studied.
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Johns CE, Topping JH, Bloxham C, Dhar A. Coeliac disease and granulomatous ileocolitis: an association or chance occurrence? J R Coll Physicians Edinb 2011; 41:319-22. [PMID: 22184569 DOI: 10.4997/jrcpe.2011.407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Enteric granulomatous inflammation can be caused by a number of conditions including Crohn's disease, sarcoidosis, enteric infections, chronic granulomatous disease and also by drug reactions. Granulomas have also been described in microscopic colitis associated with certain medications and autoimmune diseases. The association of granulomatous ileocolitis with coeliac disease is not common. We present a case of coeliac disease with granulomatous ileocolitis with follow-up and repeat histology on a gluten-free diet. We discuss the pathological mechanisms leading to the association of granulomatous ileocolitis with coeliac disease as well as other conditions.
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Jung Y, Alam S, Li Z, Dhar A, Giles D, Giles IP, Sahu JK, Poletti F, Grüner-Nielsen L, Richardson DJ. First demonstration and detailed characterization of a multimode amplifier for Space Division Multiplexed transmission systems. OPTICS EXPRESS 2011; 19:B952-B957. [PMID: 22274124 DOI: 10.1364/oe.19.00b952] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present the first demonstration of a multimode (two mode-group) erbium-doped fiber amplifier for Space Division Multiplexed (SDM) applications and demonstrate various design and performance features of such devices. In particular we experimentally demonstrate that differential modal gains can be controlled and reduced both by fiber design and control of the pump field distribution. Using a suitably designed fiber we demonstrate simultaneous modal gains of ~20 dB for different pair-wise combinations of spatial and polarization modes in an EDFA supporting amplification of 6 distinct modes.
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