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Gol AK, Bodanki CS, Yadoji H, Reddy G, Reddy MV. Decompression of Paralabral Cyst near Axillary Nerve: A Case Report. J Orthop Case Rep 2023; 13:52-56. [PMID: 37753119 PMCID: PMC10519306 DOI: 10.13107/jocr.2023.v13.i09.3874] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/12/2023] [Indexed: 09/28/2023] Open
Abstract
Introduction Paralabral cyst is benign fluid-filled lesion that occurs adjacent to glenoid labrum. Origin of the cyst can be traumatic or atraumatic. This cystic lesion can compress nearby axillary nerve or suprascapular nerve, resulting in shoulder pain and numbness. In this case report, we will discuss about anteroinferior paralabral cyst with axillary neuropathy in atraumatic condition. Case Report A 35-year-old male was admitted in our institute with complaining of numbness in the mid-part of the lateral arm and pain in the posterior aspect in the left shoulder for 2 weeks. The patient has on-and-off pain in the left shoulder on lifting weight. He had no history of trauma. X-ray was normal. On examination, tenderness presents over the dorsal aspect of shoulder and reduced sensations over deltoid muscle (regimen badge sign). Deltoid atrophy was noted. Range of motion was normal. On examination, cervical spine was normal, and reduced sensation over the lateral aspect of arm and deltoid atrophy was present. Magnetic resonance imaging (MRI) shows large multiloculated paralabral cyst caudal to inferior glenoid rim. The diagnosis was compressive axillary neuropathy which was confirmed by nerve condition study. Conclusion According to this case report, accurate early clinical examination and MRI evaluation are crucial in patients with atraumatic shoulder pain associated with neurological symptoms. On identification, cyst can be successfully decompressed by shoulder arthroscopy which can prevent axillary nerve damage, muscle denervation, and also recurrence of cyst can be avoided.
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Affiliation(s)
- Abhishek K Gol
- Department of Arthroscopy and Shoulder Surgery, Trinity Hospital, Rajkot, Gujarat, India
| | - Chandrasekhar S Bodanki
- Department of Arthroscopy and Shoulder Surgery, Sunshine Hospital and Research Centre, Secundarabad, Telangana, India
| | - Harikrishna Yadoji
- Department of Arthroscopy and Shoulder Surgery, Sunshine Hospital and Research Centre, Secundarabad, Telangana, India
| | - Guruva Reddy
- Department of Orthopedics, Sunshine Hospital and Research Centre, Secundarabad, Telangana, India
| | - M V Reddy
- Department of Orthopedics, Sunshine Hospital and Research Centre, Secundarabad, Telangana, India
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Abstract
Picobirnaviruses (PBVs) are small non enveloped viruses with bi-segmented ds RNA. They have been observed in a wide variety of vertebrates, including mammals and birds with or without diarrhoea, as well as in sewage samples since its discovery (1988). The source of the viruses is uncertain. True hosts of PBVs and their role as primary pathogens or secondary opportunistic agents or innocuous viruses in the gut remains alien. The mechanisms by which they play a role in pathogenicity are still unclear based on the fact that they can be found in both symptomatic and asymptomatic cases. There is a need to determine their tropism since they have not only been associated with viral gastroenteritis but also been reported in the respiratory tracts of pigs. As zoonotic agents with diverse hosts, the importance of epidemiological and surveillance studies cannot be overstated. The segmented genome of PBV might pose a serious public health issue because of the possibility of continuous genetic reassortment. Aware of the growing attention being given to emerging RNA viruses, we reviewed the current knowledge on PBVs and described the current status of PBVs in animals.
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Affiliation(s)
- Mareddy Vineetha Reddy
- Department of Veterinary Microbiology, College of Veterinary Science & Animal Husbandry, Nanaji Deshmukh Veterinary Science University, Jabalpur, M.P India
| | - Vandana Gupta
- Department of Veterinary Microbiology, College of Veterinary Science & Animal Husbandry, Nanaji Deshmukh Veterinary Science University, Jabalpur, M.P India
| | - Anju Nayak
- Department of Veterinary Microbiology, College of Veterinary Science & Animal Husbandry, Nanaji Deshmukh Veterinary Science University, Jabalpur, M.P India
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Yadoji HK, Bodanki C, Reddy MV, Reddy AVG. Arthroscopic Anterior Capsule Reconstruction Using Fascia Lata Autograft and Knotless Fibretak: A Case Report. J Orthop Case Rep 2022; 12:91-95. [PMID: 36660153 PMCID: PMC9826548 DOI: 10.13107/jocr.2022.v12.i05.2832] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/19/2022] [Indexed: 01/22/2023] Open
Abstract
Introduction Shoulder has multidirectional mobility with capsule and rotator cuff as stabilizers. Irreparable subscapularis tears are relatively uncommon. Anterior capsule reconstruction (ACR) is one of the different modalities of treatment for irreparable subscapularis tears. Anterior capsular reconstruction can be performed using hamstring autograft, tibialis anterior allograft, and human dermal allograft. Procedures using hamstring autograft and tibialis anterior allograft reported severe capsular deficiency, recurrent dislocation, and subluxations. Dermal allograft is routinely used for ACR anterior capsule reconstruction. But However, there are no reports of Fascia lata autograft being used for ACR anterior capsule reconstruction. As fascia lata is an autograft, it may have a better chance of healing than dermal allograft. Case Report A 60-year year-old male patient came with history of slip and fall at home 3 months ago and injured his left shoulder. Magnetic resonance imaging MRI is showing subscapularis tear retracted medial to glenoid and anterior supraspinatus tear with minimal retraction. The aim of this case report is to describe in detail the arthroscopic technique of ACR anterior capsule reconstruction using fascia lata autograft using the new knotless all suture anchors (fibereTak) on glenoid. Conclusion Fascia lata being an autograft may have better healing potential, but its superiority over dermal allografts in the setting of ACR anterior capsule reconstruction needs further studies.
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Affiliation(s)
- Hari Krishna Yadoji
- Department of Arthroscopy and Shoulder Surgery, Sunshine Hospital, Secunderabad, Telangana, India,Address of Correspondence: Dr. Hari Krishna Yadoji, Department of Arthroscopy and Shoulder Surgery, Sunshine Hospital, Secunderabad - 500 003, Telangana, India. E-mail:
| | - Chandrasekhar Bodanki
- Department of Arthroscopy and Shoulder Surgery, Sunshine Hospital, Secunderabad, Telangana, India
| | - M V Reddy
- Department of Orthopaedic, Sunshine Hospital, Secunderabad, Telangana, India
| | - A V Gurava Reddy
- Department of Orthopaedic, Sunshine Hospital, Secunderabad, Telangana, India
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Ali GAM, Divyashree A, Supriya S, Chong KF, Ethiraj AS, Reddy MV, Algarni H, Hegde G. Carbon nanospheres derived from Lablab purpureus for high performance supercapacitor electrodes: a green approach. Dalton Trans 2018; 46:14034-14044. [PMID: 28979958 DOI: 10.1039/c7dt02392h] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon nanospheres derived from a natural source using a green approach were reported. Lablab purpureus seeds were pyrolyzed at different temperatures to produce carbon nanospheres for supercapacitor electrode materials. The synthesized carbon nanospheres were analyzed using SEM, TEM, FTIR, TGA, Raman spectroscopy, BET and XRD. They were later fabricated into electrodes for cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy testing. The specific capacitances were found to be 300, 265 and 175 F g-1 in 5 M KOH electrolyte for carbon nanospheres synthesized at 800, 700 and 500 °C, respectively. These are on a par with those of prior electrodes made of biologically derived carbon nanospheres but the cycle lives were remarkably higher than those of any previous efforts. The electrodes showed 94% capacitance retention even after 5200 charge/discharge cycles entailing excellent recycling durability. In addition, the practical symmetrical supercapacitor showed good electrochemical behaviour under a potential window up to 1.7 V. This brings us one step closer to fabricating a commercial green electrode which exhibits high performance for supercapacitors. This is also a waste to wealth approach based carbon material for cost effective supercapacitors with high performance for power storage devices.
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Affiliation(s)
- Gomaa A M Ali
- Faculty of Industrial Sciences & Technology, Universiti Malaysia Pahang, Gambang, 26300, Kuantan, Malaysia
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Reddy MV, Eachempati K, Gurava Reddy AV, Mugalur A. Error Analysis: How Precise is Fused Deposition Modeling in Fabrication of Bone Models in Comparison to the Parent Bones? Indian J Orthop 2018; 52:196-201. [PMID: 29576649 PMCID: PMC5858215 DOI: 10.4103/ortho.ijortho_312_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Rapid prototyping (RP) is used widely in dental and faciomaxillary surgery with anecdotal uses in orthopedics. The purview of RP in orthopedics is vast. However, there is no error analysis reported in the literature on bone models generated using office-based RP. This study evaluates the accuracy of fused deposition modeling (FDM) using standard tessellation language (STL) files and errors generated during the fabrication of bone models. MATERIALS AND METHODS Nine dry bones were selected and were computed tomography (CT) scanned. STL files were procured from the CT scans and three-dimensional (3D) models of the bones were printed using our in-house FDM based 3D printer using Acrylonitrile Butadiene Styrene (ABS) filament. Measurements were made on the bone and 3D models according to data collection procedures for forensic skeletal material. Statistical analysis was performed to establish interobserver co-relation for measurements on dry bones and the 3D bone models. Statistical analysis was performed using SPSS version 13.0 software to analyze the collected data. RESULTS The inter-observer reliability was established using intra-class coefficient for both the dry bones and the 3D models. The mean of absolute difference is 0.4 that is very minimal. The 3D models are comparable to the dry bones. CONCLUSIONS STL file dependent FDM using ABS material produces near-anatomical 3D models. The high 3D accuracy hold a promise in the clinical scenario for preoperative planning, mock surgery, and choice of implants and prostheses, especially in complicated acetabular trauma and complex hip surgeries.
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Affiliation(s)
- M V Reddy
- Department of Orthopaedics, Sunshine Hospitals, Secunderabad, India
| | | | - A V Gurava Reddy
- Department of Orthopaedics, Sunshine Hospitals, Secunderabad, India
| | - Aakash Mugalur
- Department of Orthopaedics, Sri Narayani Hospital and Research Centre, Vellore, Tamil Nadu, India,Address for correspondence: Dr. Aakash Mugalur, Department of Orthopaedics, Sri Narayani Hospital and Research Centre, Vellore, Tamil Nadu, India. E-mail:
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Zhou J, Reddy MV, Wilson BKJ, Blair DA, Taha A, Frampton CM, Eiholzer RA, Gan PYC, Ziad F, Thotathil Z, Kirs S, Hung NA, Royds JA, Slatter TL. MR Imaging Characteristics Associate with Tumor-Associated Macrophages in Glioblastoma and Provide an Improved Signature for Survival Prognostication. AJNR Am J Neuroradiol 2017; 39:252-259. [PMID: 29191871 DOI: 10.3174/ajnr.a5441] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 09/07/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND PURPOSE In glioblastoma, tumor-associated macrophages have tumor-promoting properties. This study determined whether routine MR imaging features could predict molecular subtypes of glioblastoma that differ in the content of tumor-associated macrophages. MATERIALS AND METHODS Seven internally derived MR imaging features were assessed in 180 patients, and 25 features from the Visually AcceSAble Rembrandt Images feature set were assessed in 164 patients. Glioblastomas were divided into subtypes based on the telomere maintenance mechanism: alternative lengthening of telomeres positive (ALT+) and negative (ALT-) and the content of tumor-associated macrophages (with [M+] or without [M-] a high content of macrophages). The 3 most frequent subtypes (ALT+/M-, ALT-/M+, and ALT-/M-) were correlated with MR imaging features and clinical parameters. The fourth group (ALT+/M+) did not have enough cases for correlation with MR imaging features. RESULTS Tumors with a regular margin and those lacking a fungating margin, an expansive T1/FLAIR ratio, and reduced ependymal extension were more frequent in the subgroup of ALT+/M- (P < .05). Radiologic necrosis, lack of cystic component (by both criteria), and extensive peritumoral edema were more frequent in ALT-/M+ tumors (P < .05). Multivariate testing with a Cox regression analysis found the cystic imaging feature was additive to tumor subtype, and O6-methylguanine methyltransferase (MGMT) status to predict improved patient survival (P < .05). CONCLUSIONS Glioblastomas with tumor-associated macrophages are associated with routine MR imaging features consistent with these tumors being more aggressive. Inclusion of cystic change with molecular subtypes and MGMT status provided a better estimate of survival.
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Affiliation(s)
- J Zhou
- From the Departments of Radiology (J.Z., M.V.R., B.K.J.W.) .,Department of Pathology (J.Z., R.A.E., N.A.H., J.A.R., T.L.S.)
| | - M V Reddy
- From the Departments of Radiology (J.Z., M.V.R., B.K.J.W.)
| | - B K J Wilson
- From the Departments of Radiology (J.Z., M.V.R., B.K.J.W.)
| | | | - A Taha
- Neurosurgery (A.T.), Southern District Health Board, Dunedin, New Zealand.,Surgical Sciences (A.T., S.K.), Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - C M Frampton
- Department of Medicine (C.M.F.), University of Otago, Christchurch, New Zealand
| | - R A Eiholzer
- Department of Pathology (J.Z., R.A.E., N.A.H., J.A.R., T.L.S.)
| | | | | | - Z Thotathil
- Medical Oncology (Z.T.), Waikato District Health Board, Hamilton, New Zealand
| | - S Kirs
- Surgical Sciences (A.T., S.K.), Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - N A Hung
- Department of Pathology (J.Z., R.A.E., N.A.H., J.A.R., T.L.S.)
| | - J A Royds
- Department of Pathology (J.Z., R.A.E., N.A.H., J.A.R., T.L.S.)
| | - T L Slatter
- Department of Pathology (J.Z., R.A.E., N.A.H., J.A.R., T.L.S.)
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Azarniya A, Sovizi S, Azarniya A, Rahmani Taji Boyuk MR, Varol T, Nithyadharseni P, Madaah Hosseini HR, Ramakrishna S, Reddy MV. Physicomechanical properties of spark plasma sintered carbon nanotube-containing ceramic matrix nanocomposites. Nanoscale 2017; 9:12779-12820. [PMID: 28832057 DOI: 10.1039/c7nr01878a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recently, a wide variety of research works have focused on carbon nanotube (CNT)-ceramic matrix nanocomposites. In many cases, these novel materials are produced through conventional powder metallurgy methods including hot pressing, conventional sintering, and hot isostatic pressing. However, spark plasma sintering (SPS) as a novel and efficient consolidation technique is exploited for the full densification of high-temperature ceramic systems. In these binary nanocomposites, CNTs are added to ceramic matrices to noticeably modify their inferior properties and SPS is employed to produce fully dense compacts. In this review, a broad overview of these systems is provided and the potential influences of CNTs on their functional and structural properties are addressed. The technical challenges are then mentioned and the ongoing debates over overcoming these drawbacks are fully highlighted. The structural classification used is material-oriented. It helps the readers to easily find the material systems of interest. The SPSed CNT-containing ceramic matrix nanocomposites are generally categorized into four main classes: CNT-oxide systems; CNT-nitride systems, CNT-carbide systems, and CNT-boride systems. A large number of original curves and bubble maps are provided to fully summarize the experimental results reported in the literature. They pave the way for obviously selecting the ceramic systems required for each industrial application. The properties in consideration include the relative density, hardness, yield strength, fracture toughness, electrical and thermal conductivities, modulus, and flexural strength. These unique graphs facilitate the comparison between reported results and help the reader to easily distinguish the best method for producing the ceramic systems of interest and the optimal conditions under which the superior properties can be reached. The authors have concentrated on the microstructure evolution-physicomechanical property relationship and tried to relate each property to pertinent microstructural phenomena and address why the properties are degraded or enhanced with the variation of SPS conditions or material parameters.
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Affiliation(s)
- Abolfazl Azarniya
- Department of Materials Science and Engineering, Sharif University of Technology, P.O. Box 11155-9466, Azadi Avenue, Tehran, Iran.
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Petnikota S, Teo KW, Chen L, Sim A, Marka SK, Reddy MV, Srikanth VVSS, Adams S, Chowdari BVR. Exfoliated Graphene Oxide/MoO2 Composites as Anode Materials in Lithium-Ion Batteries: An Insight into Intercalation of Li and Conversion Mechanism of MoO2. ACS Appl Mater Interfaces 2016; 8:10884-96. [PMID: 27057928 DOI: 10.1021/acsami.6b02049] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Exfoliated graphene oxide (EG)/MoO2 composites are synthesized by a simple solid-state graphenothermal reduction method. Graphene oxide (GO) is used as a reducing agent to reduce MoO3 and as a source for EG. The formation of different submicron sized morphologies such as spheres, rods, flowers, etc., of monoclinic MoO2 on EG surfaces is confirmed by complementary characterization techniques. As-synthesized EG/MoO2 composite with a higher weight percentage of EG performed excellently as an anode material in lithium-ion batteries. The galvanostatic cycling studies aided with postcycling cyclic voltammetry and galvanostatic intermittent titrations followed by ex situ structural studies clearly indicate that Li intercalation into MoO2 is transformed into conversion upon aging at low current densities while intercalation mechanism is preferably taking place at higher current rates. The intercalation mechanism is found to be promising for steady-state capacity throughout the cycling because of excess graphene and higher current density even in the operating voltage window of 0.005-3.0 V in which MoO2 undergoes conversion below 0.8 V.
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Affiliation(s)
- Shaikshavali Petnikota
- School of Engineering Sciences and Technology, University of Hyderabad , Gachibowli, Hyderabad 500046, India
| | - Keefe Wayne Teo
- NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957, Singapore
| | - Luo Chen
- NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957, Singapore
| | - Amos Sim
- NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957, Singapore
| | - Sandeep Kumar Marka
- School of Engineering Sciences and Technology, University of Hyderabad , Gachibowli, Hyderabad 500046, India
| | | | - V V S S Srikanth
- School of Engineering Sciences and Technology, University of Hyderabad , Gachibowli, Hyderabad 500046, India
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Petnikota S, Rotte NK, Reddy MV, Srikanth VVSS, Chowdari BVR. MgO-decorated few-layered graphene as an anode for li-ion batteries. ACS Appl Mater Interfaces 2015; 7:2301-2309. [PMID: 25559260 DOI: 10.1021/am5064712] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Combustion of magnesium in dry ice and a simple subsequent acid treatment step resulted in a MgO-decorated few-layered graphene (FLG) composite that has a specific surface area of 393 m(2)/g and an average pore volume of 0.9 cm(3)/g. As an anode material in Li-ion batteries, the composite exhibited high reversible capacity and excellent cyclic performance in spite of high first-cycle irreversible capacity loss. A reversible capacity as high as 1052 mAh/g was measured during the first cycle. Even at the end of the 60th cycle, more than 83% of the capacity could be retained. Cyclic voltammetry results indicated pseudocapacitance behavior due to electrochemical absorption and desorption of lithium ions onto graphene. An increase in the capacity has been observed during long-term cycling owing to electrochemical exfoliation of graphene sheets. Owing to its good thermal stability and superior cyclic performance with high reversible capacities, MgO-decked FLG can be an excellent alternative to graphite as an anode material in Li-ion batteries, after suitable modifications.
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Affiliation(s)
- Shaikshavali Petnikota
- School of Engineering Sciences and Technology, University of Hyderabad , Gachibowli, Hyderabad 500046, India
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Hameed AS, Bahiraei H, Reddy MV, Shoushtari MZ, Vittal JJ, Ong CK, Chowdari BVR. Lithium storage properties of pristine and (Mg, Cu) codoped ZnFe2O4 nanoparticles. ACS Appl Mater Interfaces 2014; 6:10744-10753. [PMID: 24912014 DOI: 10.1021/am502605s] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
ZnFe2O4 and MgxCu0.2Zn0.82-xFe1.98O4 (where x = 0.20, 0.25, 0.30, 0.35, and 0.40) nanoparticles were synthesized by sol-gel assisted combustion method. X-ray diffraction (XRD), FTIR spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) surface area studies were used to characterize the synthesized compounds. ZnFe2O4 and the doped compounds crystallize in Fd3m space group. The lattice parameter of ZnFe2O4 is calculated to be a = 8.448(3) Å, while the doped compounds show a slight decrease in the lattice parameter with an increase in the Mg content. The particle size of all the compositions are in the range of ∼50-80 nm, and the surface area of the compounds are in the range of 11-12 m(2) g(-1). Cyclic voltammetry (CV), galvanostatic cycling, and electrochemical impedance spectroscopy (EIS) studies were used to investigate the electrochemical properties of the different compositions. The as-synthesized samples at 600 °C show large-capacity fading, while the samples reheated at 800 °C show better cycling stability. ZnFe2O4 exhibits a high reversible capacity of 575 mAh g(-1) after 60 cycles at a current density of 100 mA g(-1). Mg0.2Cu0.2Zn0.62Fe1.98O4 shows a similar capacity of 576 mAh g(-1) after 60 cycles with better capacity retention.
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Affiliation(s)
- A Shahul Hameed
- Department of Chemistry, National University of Singapore , Singapore 117543
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Goh BM, Wang Y, Reddy MV, Ding YL, Lu L, Bunker C, Loh KP. Filling the voids of graphene foam with graphene "eggshell" for improved lithium-ion storage. ACS Appl Mater Interfaces 2014; 6:9835-9841. [PMID: 24857682 DOI: 10.1021/am5022655] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Highly porous, N-doped graphene foam is synthesized by chemical vapor deposition process on nickel foam. The voids of the graphene foam can be filled with curved graphene sheets by impregnating the nickel foam template with micrometer-sized nickel powder. Subsequent etching of nickel produces a graphene "eggshells"-in-graphene foam structure. The reversible capacity of such graphene foam when used as anode in lithium ion battery is improved by the presence of graphene "eggshells", as compared to the unfilled foam. The improvement is attributed to the higher rate of lithium diffusion, better buffering of strain associated with lithiation/delithiation and higher volumetric energy density of the unique eggshell-in-graphene foam structure.
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Affiliation(s)
- Bee-Min Goh
- Department of Chemistry, Graphene Research Centre, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore
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Wu Y, Zhu P, Reddy MV, Chowdari BVR, Ramakrishna S. Maghemite nanoparticles on electrospun CNFs template as prospective lithium-ion battery anode. ACS Appl Mater Interfaces 2014; 6:1951-1958. [PMID: 24383672 DOI: 10.1021/am404939q] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this work, maghemite (γ-Fe2O3) nanoparticles were uniformly coated on carbon nanofibers (CNFs) by a hybrid synthesis procedure combining an electrospinning technique and hydrothermal method. Polyacrylonitrile nanofibers fabricated by the electrospinning technique serve as a robust support for iron oxide precursors during the hydrothermal process and successfully limit the aggregation of nanoparticles at the following carbonization step. The best materials were optimized under a carbonization condition of 600 °C for 12 h. X-ray diffraction and electron microscopy studies confirm the formation of a maghemite structure standing on the surface of CNFs. The average size of γ-Fe2O3 nanoparticles is below 100 nm, whereas CNFs are ∼150 nm in diameter. In comparison with aggregated bare iron oxide nanoparticles, the as-prepared carbon-maghemite nanofibers exhibit a higher surface area and greatly improved electrochemical performance (>830 mAh g(-1) at 50 mA g(-1) for 40 cycles and high rate capacity up to 5 A g(-1) in the voltage range of 0.005-3 V vs Li). The greatly enhanced electrochemical performance is attributed to the unique one-dimensional nanostructure and the limited aggregation of nanoparticles.
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Affiliation(s)
- Yongzhi Wu
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (NUS) , Singapore 119260
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Reddy MV, Prithvi G, Loh KP, Chowdari BVR. Li storage and impedance spectroscopy studies on Co3O4, CoO, and CoN for Li-ion batteries. ACS Appl Mater Interfaces 2014; 6:680-690. [PMID: 24325322 DOI: 10.1021/am4047552] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The compounds, CoN, CoO, and Co3O4 were prepared in the form of nano-rod/particles and we investigated the Li-cycling properties, and their use as an anode material. The urea combustion method, nitridation, and carbothermal reduction methods were adopted to prepare Co3O4, CoN, and CoO, respectively. X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and the Brunauer-Emmett-Teller (BET) surface and density methods were used to characterise the materials. Cyclic voltammetry (CV) was performed and galvanostatic cycling tests were also conducted up to 60-70 cycles. The observed reversible capacity of all compounds is of the increasing order CoO, Co3O4, CoN and all compounds showed negligible capacity fading. CoO allows for Li2O and Co metal to form during the discharge cycle, allowing for a high theoretical capacity of 715 mA h g(-1). Co3O4 allows for 4 Li2O and 3Co to form, and has a theoretical capacity of 890 mAhg(-1). CoN is the best anode material of the three because the nitrogen allows for Li3N and Co to form, resulting in an even higher theoretical capacity of 1100 mAhg(-1) due to the Li3N and Co metal formation. Irrespective of morphology the charge profiles of all three compounds showed a major plateaux ~2.0 V vs. Li and potential values are almost unchanged irrespective of crystal structure. Electrochemical impedance spectroscopy (EIS) was performed to understand variation resistance and capacitance values.
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Affiliation(s)
- M V Reddy
- Department of Physics, Solid State Ionics & Advanced Batteries Lab, §Department of Chemistry, Graphene Research Center, and ⊥Departments of Materials Science & Engineering, National University of Singapore , Singapore 117542
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Wu Y, Reddy MV, Chowdari BVR, Ramakrishna S. Long-term cycling studies on electrospun carbon nanofibers as anode material for lithium ion batteries. ACS Appl Mater Interfaces 2013; 5:12175-84. [PMID: 24171411 DOI: 10.1021/am404216j] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Electrospun carbon nanofibers (CNF) have been prepared at different calcination temperatures for a prolonged time (12 h) derived from electrospun polyacrylonitrile (PAN) membranes. They are studied as anode materials in lithium ion batteries due to their high reversible capacity, improved long-term cycle performance, and good rate capacity. The fibrous morphologies of fresh electrodes and tested samples for more than 550 cycles have been compared; cyclic voltammogram (CV) has also been studied to understand the lithium intercalation/deintercalation mechanism of 1D nanomaterials. CNFs demonstrate interesting galvanostatic performance with fading capacity after the first few cycles, and the capacity increases during long-term cycling. The increasing capacity is observed accompanied by volumetric expansion on the nanofibers' edge. Results of rate capacity have also been explored for all CNF samples, and their stable electrochemical performances are further analyzed by the galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). CNF carbonized at 800 °C is found to have a larger lithium ion storage ability and better cyclic stability than that carbonized at 600 and 1000 °C.
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Affiliation(s)
- Yongzhi Wu
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (NUS) , Singapore 119260
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15
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Cherian CT, Sundaramurthy J, Reddy MV, Suresh Kumar P, Mani K, Pliszka D, Sow CH, Ramakrishna S, Chowdari BVR. Morphologically robust NiFe2O4 nanofibers as high capacity Li-ion battery anode material. ACS Appl Mater Interfaces 2013; 5:9957-9963. [PMID: 24099146 DOI: 10.1021/am401779p] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this work, the electrochemical performance of NiFe2O4 nanofibers synthesized by an electrospinning approach have been discussed in detail. Lithium storage properties of nanofibers are evaluated and compared with NiFe2O4 nanoparticles by galvanostatic cycling and cyclic voltammetry studies, both in half-cell configurations. Nanofibers exhibit a higher charge-storage capacity of 1000 mAh g(-1) even after 100 cycles with high Coulmbic efficiency of 100% between 10 and 100 cycles. Ex situ microscopy studies confirmed that cycled nanofiber electrodes maintained the morphology and remained intact even after 100 charge-discharge cycles. The NiFe2O4 nanofiber electrode does not experience any structural stress and eventual pulverisation during lithium cycling and hence provides an efficient electron conducting pathway. The excellent electrochemical performance of NiFe2O4 nanofibers is due to the unique porous morphology of continuous nanofibers.
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Affiliation(s)
- Christie Thomas Cherian
- Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117551
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Reddy MV, Wen BLW, Loh KP, Chowdari BVR. Energy storage studies on InVO4 as high performance anode material for Li-ion batteries. ACS Appl Mater Interfaces 2013; 5:7777-7785. [PMID: 23869790 DOI: 10.1021/am401501a] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
InVO4 has attracted much attention as an anode material due to its high theoretical capacity. However, the effect of preparation methods and conditions on morphology and energy storage characteristic has not been extensively investigated and will be explored in this project. InVO4 anode material was prepared using five different preparation methods: solid state, urea combustion, precipitation, ball-milling, and polymer precursor methods. Morphology and physical properties of InVO4 were then analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) surface area method. XRD patterns showed that orthorhombic phased InVO4 was synthesized. Small amounts of impurities were observed in methods II, III, and V using XRD patterns. BET surface area ranged from 0.49 to 9.28 m(2) g(-1). SEM images showed slight differences in the InVO4 nanosized crystalline structures with respect to preparation methods and conditions. Energy storage studies showed that, among all the preparation methods, the urea combustion method produced the best electrochemical results, with negligible capacity fading between the 2nd and 50th cycles and high capacity of 1241 mA h g(-1) at the end of the 20th cycle, close to the theoretical capacity value. Precipitation method also showed good performance, with capacity fading (14%) and capacity of 1002 mA h g(-1) at the 20th cycle. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) was then used to determine the reaction mechanisms of InVO4.
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Affiliation(s)
- M V Reddy
- Department of Physics, Solid State Ionics/Advanced Batteries Lab, National University of Singapore, Singapore 117542.
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Cherian CT, Zheng M, Reddy MV, Chowdari BVR, Sow CH. Zn2SnO4 nanowires versus nanoplates: electrochemical performance and morphological evolution during Li-cycling. ACS Appl Mater Interfaces 2013; 5:6054-60. [PMID: 23738585 DOI: 10.1021/am400802j] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Zn2SnO4 nanowires have been synthesized directly on stainless steel substrate without any buffer layers by the vapor transport method. The structural and morphological properties are investigated by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical performance of Zn2SnO4 nanowires is examined by galvanostatic cycling and cyclic voltammetry (CV) measurements in two different voltage windows, 0.005-3 and 0.005-1.5 V vs Li and compared to that of Zn2SnO4 nanoplates prepared by hydrothermal method. Galvanostatic cycling studies of Zn2SnO4 nanowires in the voltage range 0.005-3 V, at a current of 120 mA g(-1), show a reversible capacity of 1000 (±5) mAh g(-1) with almost stable capacity for first 10 cycles, which thereafter fades to 695 mAh g(-1) by 60 cycles. Upon cycling in the voltage range 0.005-1.5 V vs Li, a stable, reversible capacity of 680 (±5) mAh g(-1) is observed for first 10 cycles with a capacity retention of 58% between 10-50 cycles. On the other hand, Zn2SnO4 nanoplates show drastic capacity fading up to 10 cycles and then showed a capacity retention of 80% and 70% between 10 and 50 cycles when cycled in the voltage range 0.005-1.5 and 0.005-3 V, respectively. The structural and morphological evolutions during cycling and their implications on the Li-cycling behavior of Zn2SnO4 nanowires are examined. The effect of the choice of voltage range and initial morphology of the active material on the Li-cycleabilty is also elucidated.
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Reddy MV, Yu C, Jiahuan F, Loh KP, Chowdari BVR. Li-cycling properties of molten salt method prepared nano/submicrometer and micrometer-sized CuO for lithium batteries. ACS Appl Mater Interfaces 2013; 5:4361-4366. [PMID: 23621356 DOI: 10.1021/am400579q] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report the synthesis of CuO material by molten salt method at a temperature range, 280 to 950 °C for 3 h in air. This report includes studies on the effect of morphology, crystal structure and electrochemical properties of CuO prepared at different temperatures. Obtained CuO was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area methods. Samples prepared at ≥410 °C showed a single-phase material with a lattice parameter value of a = 4.69 Å, b = 3.43 Å, c = 5.13 Å and surface area values are in the range 1.0-17.0 m(2) g(-1). Electrochemical properties were evaluated via cyclic voltammetry (CV) and galvanostatic cycling studies. CV studies showed a minor difference in the peak potentials depending on preparation temperature and all compounds exhibit a main anodic peak at ~2.45 V and cathodic peaks at ~0.85 V and ~1.25 V vs Li. CuO prepared at 750 °C showed high and stable capacity of ~620 mA h g(-1) at the end of 40th cycle.
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Affiliation(s)
- M V Reddy
- Department of Physics, Solid State Ionics & Advanced Batteries Lab, National University of Singapore, Singapore.
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Das B, Reddy MV, Chowdari BVR. X-ray absorption spectroscopy and energy storage of Ni-doped cobalt nitride, (Ni(0.33)Co(0.67))N, prepared by a simple synthesis route. Nanoscale 2013; 5:1961-1966. [PMID: 23360912 DOI: 10.1039/c2nr33675h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Metal nitride (Ni(0.33)Co(0.67))N nanoparticles are prepared by nitridation using NiCo(2)O(4) as a precursor material by heating at 335 °C for 2 h in flowing NH(3) + N(2) gas and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), high resolution-transmission electron microscopy (HR-TEM), along with selective area electron diffraction (SAED) and X-ray absorption spectroscopy (XAS) techniques. The X-ray absorption near edge structure (XANES) at the Co K-edge showed that the oxidation state of cobalt is close to 3+. The (Ni(0.33)Co(0.67))N showed a shift in edge energy towards lower values due to Ni-doping to cobalt site. The Li-storage behaviour of (Ni(0.33)Co(0.67))N nanoparticles was evaluated by galvanostatic cycling and cyclic voltammetry in the cells with Li-metal as counter electrode in the voltage range of 0.005-3.0 V at ambient temperature. When cycled at 250 mA g(-1), the first-cycle reversible capacity of 700 (±5) mA h g(-1) (~1.9 moles of Li) is obtained. It showed an initial decrease in capacity until the 10(th) cycle and a stable capacity of 400 (±5) mA h g(-1) (~1.09 moles of Li) is observed at the end of the 50(th) cycle. Excellent rate capability is also shown when cycling at 500 mA g(-1) (up to 50 cycles). The materials showed excellent Li-ion insertion/extraction, with the coulombic efficiency reaching almost 99% in the range of 10-50 cycles. The average charge and discharge potentials are ~2.03 and ~1.0 V, respectively for the decomposition/formation of Li(3)N as determined by electroanalytical techniques.
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Affiliation(s)
- B Das
- Department of Physics, National University of Singapore, Singapore 117542
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Cherian CT, Reddy MV, Haur SC, Chowdari BVR. Interconnected network of CoMoO₄ submicrometer particles as high capacity anode material for lithium ion batteries. ACS Appl Mater Interfaces 2013; 5:918-923. [PMID: 23276066 DOI: 10.1021/am302583c] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Interconnected networks of CoMoO(4) submicrometer particles are prepared by thermolysis of polymer matrix based metal precursor solution. The material exhibited a high reversible capacity of 990 (±10) mAh g(-1) at a current density of 100 mA g(-1), with 100% capacity retention between 5 and 50 cycles. The improved electrochemical performance of CoMoO(4) submicrometer particles with interconnected network like morphology makes it promising as a high-capacity anode material for rechargeable lithium ion batteries.
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Affiliation(s)
- Christie T Cherian
- Department of Physics, National University of Singapore, Singapore, 117551
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Harinath BC, Reddy MV, Bhunia B, Bhandari YP, Mehta VK, Chaturvedi P, Prajapati NC, Gupta RK. Filaria associated clinical manifestations in children in an endemic area and morbidity control by immunomonitoring and optimal DEC therapy: Sevagram experience. Indian J Clin Biochem 2012; 15:118-26. [PMID: 23105275 DOI: 10.1007/bf02867551] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Lymphatic filariasis is a major public health problem in India with 412 million people living in bancroftian endemic areas and is a major cause of clinical morbidity. Twenty million people are reported to suffer from chronic disease manifestations such as lymphoedema, hydrocele or elephantiasis. At least twice the number have been shown to suffer from acute and occult filarial infections in an endemic area without diagnosis. Due to non-availability of suitable diagnostic test for confirming filaria aetiology other than parasitological examination, no significant study on filariasis in children has been reported earlier. Studies in our laboratory for more than a decade showed usefulness of microfilarial excretory-secretory antigen in confirming filarial aetiology in acute and occult infections in adults as well as in children. This study reports acute and atypical manifestations such as lymphadenopathy, asthmatic bronchitis, pulmonary eosinophilia, mono-arthritis, recurrent URI, pneumonia, nutritional anemia, pain in abdomen etc. in children living in filaria endemic area having no microfilaraemia but showing filaria aetiology by immunomonitoring for the presence of antibody or antigen and responding to optimal DEC therapy.
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Affiliation(s)
- B C Harinath
- JB Tropical Disease Research Centre and Department of Biochemistry, Mahatma Gandhi Institute of Medical Sciences, 442102 Sevagram, (Wardha) India
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Nair ER, Kumar S, Reddy MV, Harinath BC. Mycobacterium tuberculosis H(37)Ra ESAS-7-An excretory-secretory antigen fraction of immunodiagnostic potential in pulmonary tuberculosis. Indian J Clin Biochem 2012; 13:98-105. [PMID: 23105189 DOI: 10.1007/bf02867870] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
A mycobacterial excretory-secretory protein fraction ESAS-7 purified by 50% ammonium sulphate precipitation followed by SDS-PAGE fractionation was evaluated by penicillinase enzyme linked immuno-sorbent assay (ELISA) for its sensitivity and specificity in the diagnosis of pulmonary tuberculosis. At a "cut off" serum dilution of 600, 38 (90%) of 42 sera from bacteriologically confirmed tuberculosis cases, 15 (100%) of 15 sera from bacteriogically negative but anti tubercular therapy (ATT) responded cases, 3 (7%) of 43 sera from normal healthy subjects and 4 (8%) of 48 sera from non tuberculous disease control cases gave positive reaction for tubercular antibody to ESAS-7 antigen fraction containing predominantly 33-kDa protein with a sensitivity of 90% in bacteriologically confirmed cases and specificity of 92%. Further, this diagnostic assay using the ESAS-7 antigen is more sensitive requiring as little as one nanogram antigen per test compared to use of 100 nanogram EST-6 antigen reported earlier. Thus use of ESAS-7 antigen for antibody detection has good diagnostic potential with improved specificity in pulmonary tuberculosis.
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Affiliation(s)
- E R Nair
- Jamnalal Bajaj Tropical Disease Research Centre and Department of Biochemistry, Mahatma Gandhi Institute of Medical Sciences, Sevagram, 442 102 Wardha
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Zhu P, Reddy MV, Wu Y, Peng S, Yang S, Nair AS, Loh KP, Chowdari BVR, Ramakrishna S. Mesoporous SnO2 agglomerates with hierarchical structures as an efficient dual-functional material for dye-sensitized solar cells. Chem Commun (Camb) 2012; 48:10865-7. [PMID: 23023087 DOI: 10.1039/c2cc36049g] [Citation(s) in RCA: 52] [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: 11/21/2022]
Abstract
Mesoporous SnO(2) agglomerates with hierarchical structures and a high surface area were fabricated through a molten salt method. The SnO(2) demonstrated high photoelectric conversion efficiencies of 3.05% and 6.23% (with TiCl(4) treatment) in dye-sensitized solar cells, which are attributed to its dual functionality of providing high dye-loading and efficient light scattering.
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Affiliation(s)
- Peining Zhu
- Department of Mechanical Engineering, National University of Singapore, Singapore 117574
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Subramanian S, Ayyasamy S, Selvin PC, Reddy MV, Chowdari BVR, Heller N, Dorai A, Muthusamy H. Synthesis of Li(1+x)V3O8 by chemical route and its characterization. J Nanosci Nanotechnol 2012; 12:737-742. [PMID: 22524049 DOI: 10.1166/jnn.2012.5362] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Lithium trivanadate (Li(1+x)V3O8) nanorods have been synthesized by the simple polymer precursor route using the polymer, polyvinyl pyrrolidone (PVP) as the complexing agent. Thermal behavior of the precursor has been studied by the differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) techniques. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) studies confirm the formation of the compound. High resolution scanning electron microscopy (HRSEM) analysis reveals the synthesized Li1.2V3O8 particles to be nanorods with an average diameter of 50 nm.
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Reddy MV, Pecquenard B, Vinatier P, Levasseur A. Effect of Substrate Temperature on Morphology and Electrochemical Performance of Radio Frequency Magnetron Sputtered Lithium Nickel Vanadate Films Used as Negative Electrodes for Lithium Microbatteries. J Phys Chem B 2006; 110:4301-6. [PMID: 16509727 DOI: 10.1021/jp0565554] [Citation(s) in RCA: 36] [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: 11/30/2022]
Abstract
Lithium nickel vanadate thin films were prepared by radio frequency magnetron sputtering at various substrate temperatures (Ts). These thin films have been investigated as anode electrode material in the use of microbatteries. Films were characterized by Rutherford backscattering spectroscopy, nuclear reaction analysis, Auger electron spectroscopy, glancing-incidence X-ray diffraction analysis, Raman spectroscopy, scanning electron microscopy, atomic force microscopy, and high-resolution transmission electron microscopy techniques. The anodic electrochemical performances of the films have been evaluated by cyclic voltammetry at a scan rate of 1 mV/s and by galvanostatic cycling, with lithium metal as the counter and the reference electrode, and cycled in the range of 0.02-3.0 V at a current density of 75 microA/cm2. Thin films prepared at a Ts of 650 degrees C show a discharge capacity at the 20th cycle of 1100 (+/-10) mAh/g, which exhibited excellent capacity retention with a small capacity fade.
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Affiliation(s)
- M V Reddy
- ICMCB-CNRS/ENSCPB, Université de Bordeaux 1, 33607 Pessac Cedex, France.
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Laws GM, Skopek TR, Reddy MV, Storer RD, Glaab WE. Detection of DNA adducts using a quantitative long PCR technique and the fluorogenic 5' nuclease assay (TaqMan). Mutat Res 2001; 484:3-18. [PMID: 11733068 DOI: 10.1016/s0027-5107(01)00263-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The detection of DNA adducts is an important component in assessing the mutagenic potential of exogenous and endogenous compounds. Here, we report an in vitro quantitative long PCR (XL-PCR) assay to measure DNA adducts in human genomic DNA based on their ability to block and inhibit PCR amplification. Human genomic DNA was exposed to test compounds and then a target sequence was amplified by XL-PCR. The amplified sequence was then quantified using fluorogenic 5' nuclease PCR (TaqMan) and normalized to a solvent-treated control. The extent of DNA adduction was determined based on the reduction in amplification of the target sequence in the treated sample. A 17.7kb beta-globin fragment was chosen as the target sequence for these studies, since preliminary experiments revealed a two-fold increased sensitivity of this target compared to a 10.4kb HPRT fragment for detecting hydrogen peroxide-induced DNA damage. Validation of the XL-PCR assay with various compounds demonstrated the versatility of the assay for detecting a wide range of adducts formed by direct acting or S9-activated mutagens. The same DNA samples were also analyzed using 32P-postlabeling techniques (thin-layer chromatography or high-performance liquid chromatography) to confirm the presence of DNA adducts and estimate their levels. Whereas 32P-postlabeling with nuclease P(1) enrichment was more sensitive for detecting bulky adducts induced by the compounds benzo[a]pyrene, dimethylbenzanthracene, 3-methylindole, indole 3-carbinol, or 2-acetylaminofluorene, the XL-PCR procedure was more sensitive for detecting smaller or labile DNA adducts formed by the compounds methyl methanesulfonate, diethyl nitrosamine, ethylnitrosourea, diepoxybutane, ICR-191, styrene oxide, or aflatoxin B(1). Compounds not expected to form adducts in DNA, such as clofibrate, phenobarbital, chloroform or acetone, did not produce a positive response in the XL-PCR assay. Thus, quantitative XL-PCR provides a rapid, high-throughput assay for detecting DNA damage that complements the existing 32P-postlabeling assay with nuclease P(1) enrichment.
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Affiliation(s)
- G M Laws
- Department of Genetic and Cellular Toxicology, Merck Research Laboratories, WP45-320, West Point, PA 19486, USA
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Rama Rao B, Reddy MV. A note on Goraksanātha and his work Yogadipikā. Bull Indian Inst Hist Med Hyderabad 2001; 12:34-44. [PMID: 11611679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Alli R, Kulkarni S, Reddy MV, Harinath BC. Evaluation of sevafilachek immunoassays and rapid ICT-filariasis test for detection of bancroftian filariasis. Indian J Clin Biochem 2001; 16:207-10. [PMID: 23105320 DOI: 10.1007/bf02864863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
A comparative analysis was made on the utility of SEVAFILACHEK-stick based immunoassays and commercially available ICT-filariasis test to detect active infection in different groups of bancroftian filariasis. The SEVAFILACHEK immunoassays were found to be useful to detect filarial infection in microfilaraemia and in a significant number of clinical filarial cases with acute, chronic and occult clinical manifestations. In the clinical cases, microfilariae are not usually detected in peripheral circulation. Employing SEVAFILACHEK assays 6 and 5 of the 7 samples of patients with chronic filarial disease, and 6 and 5 of 6 microfilaraemic cases gave positivity for filarial IgG antibodies and antigen respectively. Four of the 6 occult filarial samples were positive for antibodies and antigen. Filarial antigen was detected by ICT-filariasis test in blood samples of all the 6 microfilariaemic cases, 1 chronic filarial and 2 occult filarial samples. The main advantage of ICT assay is its rapid format and convenience for field use.
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Affiliation(s)
- R Alli
- Department of Biochemistry & JB Tropical Disease Research Centre, MGIMS, 442102 Sevagram(Wardha), Maharashtra India
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Banerjee S, Nair ER, Kumar S, Gangane N, Reddy MV, Harinath BC. Sero-reactivity of two different antigenic protein fractions of M.tb H37Ra excretory-secretory antigen in pulmonary and extra-pulmonary tuberculosis. J Commun Dis 2001; 33:63-71. [PMID: 12170939] [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] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Excretory-secretory proteins of Mycobacterium tuberculosis H37Ra, have been of diagnostic interest in pulmonary (PTB) and extrapulmonary tuberculosis (EPTB). Two different excretory-secretory antigenic proteins of M.tbH37Ra viz., EST-DE1 (a 6% TCA soluble and DEAE anion exchange purified antigen) and ESAS-7 (50% ammonium sulphate solubilized and SDS-PAGE fractionated antigen) were studied in stick-indirect penicillinase ELISA for detecting tuberculous IgG antibodies in serum samples of pulmonary as well as extrapulmonary tuberculosis (tuberculous lymphadenopathy (TBLN), tuberculous meningitis (TBM), bone & joint tuberculosis (B&J TB), abdominal tuberculosis (Abd. TB) patients. The ESAS-7 antigen has shown comparatively better seroreactivity (90%) than that of EST-DE1 antigen in pulmonary tuberculosis cases. The overall specificity of 93.2% using ESAS-7 antigen was also found better compared to 86.4% obtained using EST-DE1 antigen. Further, in extra pulmonary tuberculosis group, using ESAS-7 antigen 84% (21/25) of histopathologically confirmed TBLN cases and 90% (9/10) clinically diagnosed and ATT responded TBM cases showed positive reaction for tuberculous IgG antibody. The per cent positivity using EST-DE1 antigen was however comparatively low in TBLN and TBM cases, (76% and 80% respectively). In histopathologically proven bone and joint tuberculosis and abdominal tuberculosis cases EST-DE1 antigen showed better sensitivity of 75% and 83.3% respectively in IgG antibody detection compared to that of ESAS-7 antigen (50% and 66% respectively). From the present study, it can be envisaged that ESAS-7 antigenic fraction has a good potential in the diagnosis of pulmonary and certain extra-pulmonary tuberculosis infection (TBLN & TBM) whereas EST-DE1 was found to be better in detecting specific antibodies in bone & joint and abdominal tuberculosis.
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Affiliation(s)
- S Banerjee
- Jamna Lal Bajaj Tropical Disease Research Centre, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Wardha-442 102, Maharashtra
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Ganesh BB, Kader AM, Agarwal GS, Reddy MV, Harinath BC. A simple and inexpensive dot-blot assay, using a 66-kDa Brugia malayi microfilarial protein antigen, for diagnosis of bancroftian filarial infection in an endemic area. Trans R Soc Trop Med Hyg 2001; 95:168-9. [PMID: 11355549 DOI: 10.1016/s0035-9203(01)90147-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- B B Ganesh
- Department of Biochemistry and JBTDRC, Mahatma Gandhi Institute of Medical Sciences, Sevagram, India
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Affiliation(s)
- M V Reddy
- Herbert C. Brown Center for Borane Research, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393, USA
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Nair ER, Banerjee S, Kumar S, Reddy MV, Harinath BC. Purification and characterization of a 31 kDa mycobacterial excretory-secretory antigenic protein with a diagnostic potential in pulmonary tuberculosis. Indian J Chest Dis Allied Sci 2001; 43:81-90. [PMID: 11529413] [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] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Proteins secreted into the culture medium by Mycobacterium tuberculosis are shown to be a source of antigens of immunodiagnostic importance. In our earlier study, we had reported a 31-37 kDa seroreactive gel-eluted antigenic fraction (ESAS-7), isolated from culture filtrate proteins of Mycobacterium tuberculosis H37Ra. In this report, we describe further purification of excretory-secretory ESAS-7 antigen fraction by fast protein liquid chromatography (FPLC) on Resource 'S' cation-exchange column and isolation of a more active and purified protein antigen fraction ESAS-7F. ESAS-7F antigen was characterized as a 31 kDa molecular weight glycoprotein containing a metallo-serine protease activity. N-terminal sequence analysis showed the first five amino acids as NTGQS (Asp-Thr-Gly-Glu-Ser). The present study helped in the isolation of a well characterized 31 kDa mycobacterial glycoprotein antigen with protease activity and diagnostic potential in detection of tuberculosis infection.
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Affiliation(s)
- E R Nair
- Jamnalal Bajaj Tropical Disease Research Centre and Department of Biochemistry, Mahatma Gandhi Institute of Medical Sciences, Wardha, Maharashtra, India
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Abstract
[figure: see text] This first asymmetric synthesis of enantiopure desacetylumuravumbolide and umuravumbolide via asymmetric reduction, allylboration, and ring-closing metathesis confirms their revised structures and configurations. A convenient procedure to upgrade the enantiopurity of alpha,beta-acetylenic alcohols is also described.
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Affiliation(s)
- M V Reddy
- Herbert C. Brown Center for Borane Research, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393, USA
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Abstract
This article, based on a presentation on DNA adduct detection given at a Genetic Toxicology Association workshop, is an overview of methods used for testing compounds for DNA adduct formation. A DNA adduct study may be initiated on a case by case basis when there are conflicting results within the standard battery of genetic toxicology tests or when tumors are detected in the animal bioassay for nongenotoxic compounds. Methods for adduct detection include the 32P-postlabeling assay, the use of radioactive test chemicals, physicochemical methods, and immunoassays. Of these, the 32P-postlabeling assay and the use of radiochemicals are discussed in greater detail, since only these two methods are readily applicable to test a compound for the formation of uncharacterized DNA adducts. The other methods are applicable to those adducts that have been chemically characterized or that contain a fluorophore or electrochemically active groups. Evaluation of mutagenic and carcinogenic risk from DNA adducts would require the understanding of various parameters, including the chemical nature, quantity and stability of adducts, proliferation rates for target cells to fix adducts into mutations, mutagenic and repair efficiencies of adducts, and the extent of modifications in critical genes. Since such data cannot be readily obtainable, the toxicological risk from uncharacterized adducts is difficult to assess.
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Affiliation(s)
- M V Reddy
- Genetic and Cellular Toxicology, Merck Research Laboratories, West Point, Pennsylvania 19486, USA
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Dua SK, Reddy MV, Szerszen P, Rose RW, Roelant D, Ebadian MA. Electret ion chambers for estimating alpha particle energy. Health Phys 2000; 79:703-711. [PMID: 11089808 DOI: 10.1097/00004032-200012000-00017] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Electret ion chambers (EICs) are inexpensive, lightweight, robust, commercially available, passive, charge-integrating devices for measuring different radiations. At Florida International University's Hemispheric Center for Environmental Technology (FIU-HCET), EIC performance was evaluated with the goal of providing the U.S. Department of Energy (DOE) with a low-cost, low-risk means of alpha contamination monitoring using an existing commercial technology. During this evaluation, sensitivity of electrets in 960-mL hemispherical ion chamber (radius: 7.6 cm) was observed to increase with alpha particle energy because alpha particles expended their entire energy in the chamber volume. This observation prompted us to explore another EIC application: estimation of alpha particle energy. Correlation between electret mid-point voltage, alpha particle energy, and response was developed for the 960-mL EIC and was used to determine energy of an unknown source. The response (change in voltage per disintegration) is the ratio of the change of voltage per unit time and alpha particle activity. Since an EIC measures only the change in voltage per minute, to determine the alpha particle energy, the source activity should be accurately determined by another method.
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Affiliation(s)
- S K Dua
- Hemispheric Center for Environmental Technology, Florida International University, Miami 33174, USA
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Pramanik J, Lodam AN, Badole CM, Reddy MV, Patond KR, Harinath BC. Detection of tubercular antibody and antigen in sera of bone and joint tuberculosis. Indian J Clin Biochem 2000; 15:22-8. [PMID: 23105233 DOI: 10.1007/bf02873543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Trichloroacetic acid (TCA) solubilized and DEAE fractionatedMycobacterium tuberculosis H(37)Ra excretory-secretory (ES) antigen viz., Mtb EST DE1 and affinity purified goat antibodies to the TCA solubilized ES antigen (Mtb EST) were explored in detecting tubercular antibody and antigen respectively in sera of bone and joint tuberculosis by indirect and sandwich ELISA. Out of total 36 bone & joint tuberculosis cases, tubercular antibody was detected by indirect ELISA in 30 patients (sensitivity 83%), while circulating tubercular antigen was detected by sandwich ELISA in 27 patients (sensitivity 75%). Out of 34 non tubercular disease control cases, 10 patients showed positive reaction for antibody while only 4 patients showed positive reaction for antigen. In another group of 34 healthy subjects who were screened, 4 individuals showed positive reaction for tubercular antibody and 2 cases for antigen. This study shows that antigen detection assay using affinity purified anti Mtb EST antigen antibody is superior with overall specificity of 91% as compared to antibody detection assay with 75% specificity in bone & joint tuberculosis.
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Affiliation(s)
- J Pramanik
- Jamnalal Bajaj Tropical Disease Research Centre & Department of Biochemistry, Mahatma Gandhi Institute of Medical Sciences, 442 102 Sevagram (Wardha)
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Gupta S, Singh KK, Vyas VJ, Chaturvedi VN, Reddy MV, Harinath BC. Assessment of oxidative stress and effect of antioxidant supplementation during radiotherapy in carcinoma of upper digestive tract. Indian J Clin Biochem 2000; 15:52-5. [PMID: 23105239 PMCID: PMC3453538 DOI: 10.1007/bf02873549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Oxidative stress was studied by estimating plasma levels of malondialdehyde (MDA), beta carotene, vitamin E and erythrocytic superoxide dismutase(E-SOD) activity in 50 cases of carcinoma of upper digestive tract which included carcinoma of oral cavity, pharynx and oesophagus. While plasma MDA level was found to be increased (3.5±1.0 nmole/ml), a significant decrease in beta carotene (81.2±14.5mg%), vitamin E (8.5±1.1 mg/L) level and E-SOD activity (657.0±80.6 U/G Hb) were observed in carcinoma of upper digestive tract. Patients were treated with radiotherapy which itself was toxic enough and produced its deleterious effects by generation of reactive oxygen species (ROS). As antioxdiants can detoxify ROS, beneficial effect if any, of antioxidant administration during radiotherapy was studied in two groups of patients, group A (n=5, supplemented with antioxidants) and group B (n=5, without antioxidant supplementation). Plasma MDA level was found to be elevated in both the groups but the increase in group B was significant, compared to pretreatment level. Further, body weight was found to be significantly decreased in group B patients, which was maintained in group A patients. Moreover, group A patients showed significant elevation in beta carotene concentration, thus showing beneficial effect of administration of antioxidants during radiotherapy without disturbing the desirable therapeutic effect of radiotherapy.
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Affiliation(s)
- S Gupta
- Jamnalal Bajaj Tropical Disease Research Centre, Mahatma Gandhi Institute of Medical Sciences, Sevagram, 442102 Wardha
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Reddy MV, Alli R, Harinath BC. Host protective immunity and vaccine development studies in lymphatic filariasis. Indian J Clin Biochem 2000; 15:127-35. [PMID: 23105276 DOI: 10.1007/bf02867552] [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] [Indexed: 11/24/2022]
Abstract
Lymphatic filariasis caused mainly by infection fromWuchereria bancrofti andBrugia malayi remains as the major cause of clinical morbidity in tropical and subtropical countries. Development of vaccine against filarial infection can act as additional measure to the existing therapeutic and vector control methods in the control of this disease. The main hurdles in the development of anti-filarial vaccine are the strict primate specificity ofWuchereria bancrofti, the paucity of parasite material, the diversity of clinical manifestations and their associated complex immune responses, lack of clear understanding on host-parasite interactions and the mechanisms involved in protective immunity. However in the past few years, the information generated in immuno-epidemiological studies, correlated with observations in experimental animals suggests that a filarial vaccine is feasible. Initially live irradiated infective larvae have been successfully used to induce high level of protective immunity in several animal models. Applying diverse strategies, variety of purified or recombinant filarial antigens have been explored for their ability to induce protection in different host-parasite systems. Some of these targeted filarial antigens induced high level of resistance in experimental animals against challenge infections. More focussed studies on thorough characterization of parasitological and immunological changes associated with resistance induced by such candidate protective antigens and on delivery mechanisms and safety aspects will be crucial in their selection for possible use in humans.
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Affiliation(s)
- M V Reddy
- Department of Biochemistry & JB Tropical Disease Research Centre, Mahatma Gandhi Institute of Medical Sciences, 442 102 Sevagram, (Wardha) India
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Alli R, Bhandari YP, Reddy MV, Harinath BC. Seroreactivity of purified Brugia malayi microfilarial soluble and excretory-secretory antigens in different clinical presentations of bancroftian filariasis. Indian J Exp Biol 2000; 38:791-6. [PMID: 12557912] [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] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Brugia malayi microfilarial excretory-secretory (mf ES) and phosphate buffer saline soluble (mf S) antigens were fractionated by fast protein liquid chromatography (FPLC) on superdex 200 HR 10/30 gel filtration column. The active antigen fractions were identified and explored in comparison with whole mf ES and mf S antigens to detect filarial IgG antibodies in different groups viz microfilaraemics, acute, chronic and occult filarial cases of Wuchereria bancrofti infection and endemic and non-endemic normals. One of the fractions of mf ES antigen (ESF-6) and two fractions of mf S antigen (SF-2 & 3) were identified to be useful to detect filarial antibodies. A pooled preparation of these antigen fractions gave a sensitivity of 86.6% (for microfilaraemic cases) and a specificity of 95% to detect filarial IgG antibodies by indirect ELISA. The pooled FPLC purified mf antigens also showed 55-88% of cases of different grades of clinical filariasis and 65% of tropical pulmonary eosinophilia cases as positive for filarial antibodies. The pooled FPLC purified B. malayi mf antigens with higher specificity are preferable to whole mf ES and mf S antigens to detect active filarial infection in microfilaraemia and as well in different clinical entities of bancroftian filariasis.
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Affiliation(s)
- R Alli
- Department of Biochemistry & JB Tropical Disease Research Centre, MGIMS, Sevagram (Wardha) 442 102, India
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Vasu C, Reddy MV, Harinath BC. A 43-kDa circulating filarial antigen fraction of Wuchereria bancrofti in immunoprophylaxis against Brugia malayi in jirds. Parasitol Int 2000; 48:281-8. [PMID: 10725691 DOI: 10.1016/s1383-5769(99)00033-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A 43 kiloDaltan (kDa) antigen fraction (CFA2-6) isolated from microfilaraemic plasma of bancroftian filarial patients showed selective reactivity with sera samples collected from endemic normals. Antibodies raised against this antigen showed a strong reactivity with the surface of Brugia malayi infective larvae as well as microfilariae. Similar antigenic determinants were detected in the parasite extracts, but not in the excretory-secretory products. Further analysis was done on the immunoprophylactic potential of CFA2-6 in inducing immunity against Brugia malayi in Meriones unguiculatus (jird) in vivo. A strong protective response of approximately 84% was observed against the development of the filarial parasite in the jirds immunized with CFA2-6. The immunized jirds also showed a significant clearance (87%) of microfilariae inoculated intravenously. Approximately 65% of infective larvae failed to survive in jirds transferred with anti-CFA2-6 serum compared to the jirds transferred with sera from the control jirds. Passive transfer of anti-CFA2-6 antibody to the jirds followed by intravenous inoculation of microfilariae resulted in the reduction of 77% of circulating microfilariae. This study suggests that the 43-kDa CFA2-6 could stimulate a strong protective immune response against infective larvae and microfilariae in experimental animals.
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MESH Headings
- Animals
- Antibodies, Helminth/biosynthesis
- Antibodies, Helminth/immunology
- Antigens, Helminth/immunology
- Brugia malayi/immunology
- Elephantiasis, Filarial/blood
- Elephantiasis, Filarial/immunology
- Elephantiasis, Filarial/parasitology
- Elephantiasis, Filarial/prevention & control
- Enzyme-Linked Immunosorbent Assay
- Gerbillinae
- Humans
- Immunization, Passive
- Male
- Mice
- Mice, Inbred BALB C
- Microfilariae
- Microscopy, Fluorescence
- Wuchereria bancrofti/immunology
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Affiliation(s)
- C Vasu
- Department of Biochemistry and J.B. Tropical Disease Research Centre, M.G. Institute of Medical Sciences, Sevagram 442 102, Wardha, MS, India.
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Phillips DH, Farmer PB, Beland FA, Nath RG, Poirier MC, Reddy MV, Turteltaub KW. Methods of DNA adduct determination and their application to testing compounds for genotoxicity. Environ Mol Mutagen 2000; 35:222-233. [PMID: 10737957 DOI: 10.1002/(sici)1098-2280(2000)35:3<222::aid-em9>3.0.co;2-e] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
At the International Workshop on Genotoxicity Test Procedures (IWGTP) held in Washington, DC (March 25-26, 1999), a working group considered the uses of DNA adduct determination methods for testing compounds for genotoxicity. When a drug or chemical displays an unusual or inconsistent combination of positive and negative results in in vitro and in vivo genotoxicity assays and/or in carcinogenicity experiments, investigations into whether or not DNA adducts are formed may be helpful in assessing whether or not the test compound is a genotoxin. DNA adduct determinations can be carried out using radiolabeled compounds and measuring radioactive decay (scintillation counting) or isotope ratios (accelerator mass spectrometry) in the isolated DNA. With unlabeled compounds adducts may be measured by (32)P-postlabeling analysis of the DNA, or by physicochemical methods including mass spectrometry, fluorescence spectroscopy, or electrochemical detection, or by immunochemical methods. Each of these approaches has different strengths and limitations, influenced by sensitivity, cost, time, and interpretation of results. The design of DNA binding studies needs to be on a case-by-case basis, depending on the compound's profile of activity. DNA purity becomes increasingly important the more sensitive, and less chemically specific, the assay. While there may be adduct levels at which there is no observable biological effect, there are at present insufficient data on which to set a threshold level for biological significance.
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Affiliation(s)
- D H Phillips
- Institute of Cancer Research, Haddow Laboratories, Sutton, United Kingdom.
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Rao MR, Venkatesham U, Reddy MV, Venkateswarlu Y. An unusual novel C(29) steroid from the soft coral lobophytum crassum. J Nat Prod 1999; 62:1352. [PMID: 10514335 DOI: 10.1021/np990388f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Harinath BC, Reddy MV, Alli R, Mehta VK, Chaturvedi P, Patond KR, Kalantri SP, Gupta RK. Immunomonitoring followed by optimal dec therapy for successful management of clinical filariasis in an endemic area. Indian J Clin Biochem 1999; 14:100-8. [PMID: 23105207 DOI: 10.1007/bf02867907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Lymphatic filariasis continues to be the major cause of clinical morbidity in India and other developing tropical countries. One of the major lacunae in the effective management of clinical filarial cases is the non-availability of a suitable diagnostic test for confirming filaria aetiology in acute, chronic and occult clinical cases where microfilariae (mf) are not usually seen in peripheral circulation. Studies in our laboratory have shown the usefulness of filarial antibody and antigen assays using microfilarial excretory-secretory (mf ES) antigen in detecting microfilaraemic, acute and chronic filarial cases and in confirming filarial aetiology in occult infections. Diethylcarbamazine citrate (DEC) is the drug of choice for lymphatic filariasis. Different regimens of DEC have been explored in the treatment of microfilaraemic cases. Immunomonitoring has shown that the seroconversion of antigen and antibody positivity was found to be very helpful in determining appropriate period of DEC treatment for clinical relief and cure in clinical filarial patients and further they did not have recurrence in most of the cases. Optimal DEC (6mg/kg body wt/day for 21 days each month for 3-12 months) therapy was found to be very effective in acute and atypical clinical manifestations such as asthmatic bronchitis, pulmonary eosinophilia, monoarthritis, recurrent upper respiratory tract infections (URI), pneumonia (super imposed infections) in children and minimal hydrocele, epididymoorchitis, lymphangitis, lymphadenitis, acute abdomen, central serous retinopathy, tenosynovitis, pain and swelling in limbs and joints in adults living in filaria endemic areas.
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Affiliation(s)
- B C Harinath
- Department of Biochemistry, Mahatma Gandhi Institute of Medical Sciences, Sevagram, 442 102 Wardha, India
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45
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Reddy MV, Rao MR, Rhodes D, Hansen MS, Rubins K, Bushman FD, Venkateswarlu Y, Faulkner DJ. Lamellarin alpha 20-sulfate, an inhibitor of HIV-1 integrase active against HIV-1 virus in cell culture. J Med Chem 1999; 42:1901-7. [PMID: 10354398 DOI: 10.1021/jm9806650] [Citation(s) in RCA: 220] [Impact Index Per Article: 8.8] [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] [Indexed: 11/29/2022]
Abstract
HIV-1 integrase is an attractive target for anti-retroviral chemotherapy, but to date no clinically useful inhibitors have been developed. We have screened diverse marine natural products for compounds active against integrase in vitro and found a series of ascidian alkaloids, the lamellarins, that show selective inhibition. A new member of the family named lamellarin alpha 20-sulfate (1), the structure of which was determined from spectroscopic data, displayed the most favorable therapeutic index. The site of action of lamellarin alpha 20-sulfate on the integrase protein was mapped by testing activity against deletion mutants of integrase. Inhibition of isolated catalytic domain was detectable though weaker than inhibition of full length integrase; possibly lamellarin alpha 20-sulfate binds a site composed of multiple integrase domains. Lamellarin alpha 20-sulfate also inhibited integration in vitro by authentic HIV-1 replication intermediates isolated from infected cells. Lamellarin alpha 20-sulfate was tested against wild type HIV using the MAGI indicator cell assay and found to inhibit early steps of HIV replication. To clarify the inhibitor target, we tested inhibition against an HIV-based retroviral vector bearing a different viral envelope. Inhibition was observed, indicating that the HIV envelope cannot be the sole target of lamellarin alpha 20-sulfate in cell culture. In addition, these single round tests rule out action against viral assembly or budding. These findings provide a new class of compounds for potential development of clinically useful integrase inhibitors.
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Affiliation(s)
- M V Reddy
- Organic Chemistry Division-I, Natural Products Laboratory, Indian Institute of Chemical Technology, Hyderabad 500 007, India
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46
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Mehta VK, Lohar H, Banerjee GK, Reddy MV, Harinath BC. Surgical filariasis: immunoscreening for filarial IgG antibodies using Wuchereria bancrofti microfilarial excretory-secretory antigen. J Commun Dis 1999; 31:35-40. [PMID: 10810584] [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] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
A clinical study and immunoscreening was conducted on 363 suspected filarial patients attending the surgery out patient division of the MGIMS, Sevegram. The disease was significantly higher in males (86%) than in females (14%). Majority (52.9%) of the cases were in the age group of 11-30 years. The distribution of cases into three different grades of infection showed, 52.6%, 33.3% and 14.1% of the cases having acute (grade I), sub-acute (grade II) and chronic (grade III) stages of infection respectively. While 73% of the cases had genital manifestations, 23% were with lymphatic obstruction in limbs and the rest of the 4% suffered from manifestations like cellulitis, abscesses, haematuria and chyluria. Filarial IgG antibodies against microfilarial excretory-secretory (mf ES) antigen were detected in 89% of cases with genital manifestations, 87% of lymphoedema cases, 67% of lymphadenitis cases and 60% of cases with other clinical manifestations and 3% of endemic normals.
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Affiliation(s)
- V K Mehta
- Department of Surgery, MGIMS, Sevagram, Maharashtra
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47
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Abstract
Interaction of IL-3 with its receptor is known to activate STAT-3 via phosphorylation of Tyrosine 701, which facilitates its dimerization and translocation to the nucleus, leading to the transcription of its target genes. In this communication, we have investigated the nature of tyrosine kinases that mediate STAT-3 phosphorylation during IL-3-mediated activation of myeloid cell proliferation. Our results show that interaction of IL-3 with its receptor leads to the activation of c-Src kinase activity, which in turn facilitates the binding of c-Src to STAT-3. This association leads to the phosphorylation of STAT-3, allowing this transcription factor to translocate to the nucleus. Expression of a dominant negative mutant of src (AMSrc) in these cells results in a block to IL-3 mediated phosphorylation of STAT-3, and its ability to bind to DNA. On the other hand, expression of a dominant negative mutant of JAK2 (JAK2KE) had no effect on IL-3-mediated activation of STAT-3. Our results also show that AMSrc does not affect the phosphorylation of JAK2, suggesting that JAK and STAT phosphorylation events are mediated by two independent pathways. Inhibition of c-Src activation by AMSrc, which leads to a block to STAT-3 activation, results in a dramatic inhibition of cell proliferation mediated by IL-3. However, expression of AMSrc does not activate apoptotic pathways. In contrast, expression of JAK2KE results in accelerated apoptosis of 32Dcl3 cells grown in the absence of IL-3 with concomitant down-regulation of Erk-2 kinase activity. These results suggest that Src family kinases mediate the phosphorylation of STATs and play a critical role in signal transduction pathways associated with myeloid cell proliferation while JAK kinases mediate the activation of Erk-2 pathway which appears to provide antiapoptotic signals. Thus the activation of JAKs and STATs appear to be two independent but related events, which dictate two separate biological outcomes, the combination of which results in proliferation and survival of myeloid precursor cells.
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Affiliation(s)
- P Chaturvedi
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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48
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Reddy MV. Pictorial CME. J Assoc Physicians India 1998; 46:203. [PMID: 11273112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Affiliation(s)
- M V Reddy
- Intensive Care Unit, Jagjivan Hospital, Western Railway, Mumbai Central, Mumbai
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49
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Raju PS, Prasad KV, Venkata RY, Murthy KJ, Reddy MV. Influence of intensive yoga training on physiological changes in 6 adult women: a case report. J Altern Complement Med 1998; 3:291-5. [PMID: 9430331 DOI: 10.1089/acm.1997.3.291] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The short-term effects of 4 weeks of intensive yoga practice on physiological responses in six healthy adult female volunteers were measured using the maximal exercise treadmill test. Yoga practice involved daily morning and evening sessions of 90 minutes each. Pre- and post-yoga exercise performance was compared. Maximal work output (Wmax) for the group increased by 21%, with a significantly reduced level of oxygen consumption per unit work but without a concomitant significant change in heart rate. After intensive yoga training, at 154 Wmin(-1) (corresponding to Wmax of the pre-yoga maximal exercise test) participants could exercise more comfortably, with a significantly lower heart rate (p < 0.05), reduced minute ventilation (p < 0.05), reduced oxygen consumption per unit work (p < 0.05), and a significantly lower respiratory quotient (p < 0.05). The implications for the effect of intensive yoga on cardiorespiratory efficiency are discussed, with the suggestion that yoga has some transparently different quantifiable physiological effects to other exercises.
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Affiliation(s)
- P S Raju
- Department of Work-Physiology, Govt. Vemana Yoga Research Institute, Ameerpet, Hyderabad, India
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50
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Reddy MV, Blackburn GR, Schreiner CA, Mackerer CR. Correlation of mutagenic potencies of various petroleum oils and oil coal tar mixtures with DNA adduct levels in vitro. Mutat Res 1997; 378:89-95. [PMID: 9288888 DOI: 10.1016/s0027-5107(97)00100-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
An in vitro system was utilized to measure DNA adduct-forming ability of petroleum oils and oil coal tar mixtures to define correlations between DNA adduct levels and their mutagenic potencies. The system consisted of reaction of dimethyl sulfoxide extracts of oils with calf thymus DNA in the presence of Aroclor-induced hamster liver microsomes for 30 min. Following DNA extraction, DNA adducts were measured by the nuclease P1-enhanced postlabeling assay coupled with two-dimensional polyethyleneimine (PEI)-cellulose TLC. Thin layer plates showed putative aromatic DNA adducts, with levels ranging from 60 to 1400 adducts per 10(9) DNA nucleotides. TLC mobilities suggested adducts to be aromatic compounds containing 4 or more rings. A good correlation (coefficient of correlation = 0.91) was observed between DNA adduct levels and Salmonella mutagenicity for 19 oils. All 19 samples tested produced DNA adducts. To expedite the TLC procedure, adducts were resolved by one-dimensional TLC and the radioactivity measured using a mechanical scanner. Results were comparable to those obtained by two-dimensional TLC and quantification after scraping. Our data show that the in vitro incubation system coupled with the postlabeling adduct assay is a useful screening method to identify mutagenic and potentially carcinogenic oils.
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Affiliation(s)
- M V Reddy
- Environmental and Health Sciences Laboratory, Mobil Oil Corporation, Princeton, NJ 08534, USA
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