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Balamurugan B, Ghosh SK, Lone SA, Prasad JK, Ramamoorthy M, Kumar A. Correlation between dissolved oxygen level, antioxidants and oxidants in semen diluted with partially deoxygenated extender at various stages of cryopreservation. Cryo Letters 2022; 43:158-166. [PMID: 36626140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Dissolved oxygen (DO) in semen dilutor may lead to the production of reactive oxygen species (ROS) and buffalo sperm may become more prone to deleterious effects of ROS due to the presence of high amounts of polyunsaturated fatty acids (PUFAs) in their membranes. OBJECTIVE To study the correlation between dissolved oxygen level, antioxidants and oxidants in semen diluted with partially deoxygenated extender at various stages of cryopreservation. MATERIALS AND METHODS Each semen sample was split into two aliquots viz., Aliquot I [diluted with Extender I (control: without deoxygenation)] and Aliquot II [diluted with Extender II: partially deoxygenated by liquid nitrogen (LN) flushing], which were diluted, filled in straws, cryopreserved and evaluated post-thaw. RESULTS The DO levels (P < 0.05) decreased significantly after LN flushing of the extender and they increased significantly (P < 0.05) in post-thaw semen. The progressive motility, viability, hypo-osmotic swelling response, acrosomal integrity, glutathione peroxidase (GPx), total antioxidant capacity (TAC) and superoxide dismutase (SOD) decreased significantly (P < 0.05) in both control and treated semen after thawing. SOD and TAC were positively correlated in semen treated with normal extender at the pre-freeze stage; however, in semen treated with partially deoxygenated extender, no correlation was found between SOD and TAC at the pre-freeze stage. ROS and total TAC were negatively correlated in semen treated with partially deoxygenated extender at the pre-freeze stage; however, no correlation was found between ROS and TAC in control semen. CONCLUSION The partial deoxygenation of extender affects the correlation between sperm quality parameters, antioxidants, and oxidants during different stages of semen cryopreservation. doi.org/10.54680/fr22310110712.
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Affiliation(s)
- B Balamurugan
- Department of Veterinary Gyneacology and Obstetrics, BHU-Faculty of Veterinary and Animal Science, RGSC, Barkachha, Uttar Pradesh-231001, India
| | - S K Ghosh
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - S A Lone
- Animal Husbandry Department, Government of Jammu & Kashmir, India.
| | - J K Prasad
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - M Ramamoorthy
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - A Kumar
- Biochemistry Division, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
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Subramaniam A, Balamurugan B. Anaesthetic Management of Suspect COVID-19 Patient during a COVID-19 Pandemic Presenting for Emergency Limb Saving Surgery. JPRI 2022. [DOI: 10.9734/jpri/2022/v34i10a35517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Covid-19 pandemic is an unprecedented crisis and has changed dynamics of health care by severely straining the resources for patients coming for both elective and emergency surgeries. Ultrasound guided nerve block has been a life saver in most covid-19 positive patients coming for emergency surgical procedures as they reduce the risk of general anaesthesia in a patient with already compromised lung physiology and also minimizes risk of aerosol contamination of the operation theatre and health care personnel. We describe the anaesthetic management of a 67year old male patient with uncontrolled diabetes mellitus and sepsis for diabetic foot wound fasciotomy and wound debridement. The patient was operated under ultrasound guided popliteal sciatic and Saphenous nerve block of the right lower limb with all precautions taken to prevent covid spread as the patient had a high index of suspicion for covid-19. The patient was reported positive for RT-PCR in the postoperative period.
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Induja S, Anand ., Balamurugan B. Anaesthetic Management of Pre Eclamptic Patient with Solitary Kidney and Uterine Didelphys Posted for Emergency Caesarean Section: A Case Report. JPRI 2021. [DOI: 10.9734/jpri/2021/v33i64a35304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Uterine didelphys results from impaired fusion of the paired Müllerian ducts. The incidence of uterine anomalies is believed to be 0.5–2.0% of reproductive-age women, with didelphic uterus renal agenesis accounting for approximately 10%. Uterine didelphys is associated with in approximately 25% of cases1. Pre eclampsia is defined as SBP more than 160 mmhg, DBP more than 90 mmhg, associated with proteinuria and urine protein excretion >300mg in a 24 hour period or a protein creatinine ratio of atleast 0.32. Neuraxialblockade stands an effective mode of anaesthesia for these patients. Management of pre eclampticpatient with solitary kidney can be a challenge to anaesthesiologist due tovarious metabolic derangements including hyperkalemia, hypocalcemia, hyperphosphatemia and metabolic acidosis.Multidisciplinary approach is required to have good pregnancy outcome in these patients.
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Singh KK, Balamurugan B, Smieee NC, Rawal Kshatriya BS. Machine Learning approaches for convergence of IoT and Blockchain. Open Computer Science 2020. [DOI: 10.1515/comp-2020-0207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractBlockchain plays a significant role in providing security during data handling operations and defines how trusted transactions can be carried out addressing the solution for internet facing vulnerability problems. Blockchain solves the security fault line among AI and IoT, where most of the IoT devices are connected to each other through public networks. This special issue aims to publish a collection of high quality research articles in the area of blockchain, IoT and Machine Learning.
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Affiliation(s)
- Krishna Kant Singh
- Department of ECE, KIET Group of Institutions, Delhi-NCR, Ghaziabad, India
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Ramasubbareddy S, Balamurugan B, Sankar S, Srinivasan P. Energy-aware multipath routing protocol for internet of things using network coding techniques. IJGUC 2020. [DOI: 10.1504/ijguc.2020.10032056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sankar S, Srinivasan P, Ramasubbareddy S, Balamurugan B. Energy-aware multipath routing protocol for internet of things using network coding techniques. IJGUC 2020. [DOI: 10.1504/ijguc.2020.110899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Veningston K, Kadry S, Kalash HS, Balamurugan B, Sathiyaraj R. Intelligent social network based data modeling for improving health care. Health Technol 2019. [DOI: 10.1007/s12553-019-00303-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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T. MuthamilSelvan, Balamurugan B. Comparative Performance Analysis of Various Classifiers for Cloud E-Health Users. International Journal of E-Health and Medical Communications 2019. [DOI: 10.4018/ijehmc.2019040105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Several classifiers are prevalent which act as a major drive for almost all supervised machine learning applications. These classifiers, though their objective working looks similar, they vary drastically in their performances. Some of the important factors that cause such variations are the scalability of the dataset, dataset nature, training time estimation, classifying time for the test data, prediction accuracy and the error rate computation. This paper focuses mainly on analyzing the performance of the existing four main classifiers: IF-THEN rule, C4.5 decision trees, naïve Bayes, and SVM classifier. The objective of this research article is to provide the complete statistical performance estimates of the four classifiers to the authenticated cloud users. These users have the access facility in obtaining the essential statistical information about the classifiers in study from the cloud server. Such statistical information might be helpful in choosing the best classifier for their personal or organizational benefits. The classifiers follow the traditional underlying algorithms for classification that is performed in the cloud server. These classifiers are tested on three different datasets namely PIMA, breast-cancer and liver-disorders dataset for performance analysis. The performance analysis indicators used in this research article to summarize the working of the various classifiers are training time, testing time, prediction accuracy and error rate computation. The proposed comparative analysis framework can be used to analyze the performances of the classifiers with respect to any input dataset.
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Affiliation(s)
- T. MuthamilSelvan
- School of Information Technology & Engineering, VIT University, Vellore, India
| | - B. Balamurugan
- School of Information Technology & Engineering, VIT University, Vellore, India
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Lone SA, Prasad JK, Ghosh SK, Das GK, Balamurugan B, Verma MR. Study on correlation of sperm quality parameters with antioxidant and oxidant status of buffalo bull semen during various stages of cryopreservation. Andrologia 2018; 50:e12970. [PMID: 29430680 DOI: 10.1111/and.12970] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2017] [Indexed: 11/30/2022] Open
Abstract
This investigation was carried out to study the correlation of sperm quality parameters with antioxidant and oxidant status of buffalo bull semen during various stages of cryopreservation. Semen samples were evaluated for sperm parameters (mass motility [MM], concentration [CON], progressive motility [PM], viability [VIB], acrosomal integrity [AI] and hypo-osmotic swelling [HOS] response), antioxidants (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx] and total antioxidant capacity [TAC]) and oxidants (Lipid peroxidation [LPO] and reactive oxygen species [ROS]) at fresh, pre-freeze and post-thaw stages. Sperm parameters (PM, VIB, AI and HOS response) and antioxidants (SOD, CAT and TAC) were significantly (p < .05) reduced at fresh stage, and oxidants (LPO and ROS) were significantly (p < .05) increased at pre-freeze and post-thaw stages. At fresh stage, MM was negatively correlated with LPO (p < .05), and CON was positively correlated with SOD, TAC and CAT, negatively correlated with LPO and CAT was positively (p < .01) correlated with VIB and HOS response. At pre-freeze stage, CAT was positively correlated with PM and AI (p < .05), and AI was negatively (p < .05) correlated with ROS. At post-thaw stage, CAT was positively correlated with PM, VIB, HOS response and AI,, and LPO was negatively correlated with HOS, AI and VIB. The study of correlations of these parameters at different preservation stages with bull fertility may play an important role in developing models for predicting future fertility of bulls in the absence of conception rate data.
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Affiliation(s)
- S A Lone
- Animal Reproduction, Gynecology & Obstetrics, Artificial Breeding Research Center (ABRC), ICAR-National Dairy Research Institute, Karnal, India
| | - J K Prasad
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - S K Ghosh
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - G K Das
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - B Balamurugan
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - M R Verma
- Division of Livestock Economics and Statistics, ICAR-Indian Veterinary Research Institute, Izatnagar, India
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Balamurugan B, Ghosh SK, Lone SA, Prasad JK, Das GK, Katiyar R, Mustapha AR, Kumar A, Verma MR. Effect of Liquid Nitrogen Flushing of Extender on Seminal Antioxidant Profile of Murrah Buffalo during Cryopreservation. Cryo Letters 2018; 39:279-287. [PMID: 30963159] [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: 06/09/2023]
Abstract
BACKGROUND The dissolved oxygen in the extender may act as a source for the production of reactive oxygen species that may lead to reduced seminal antioxidant profile which in turn may be responsible for impaired frozen thawed sperm quality and fertility. OBJECTIVE To study the effect of adding liquid nitrogen into the extender on semen freezability and seminal antioxidant profile in buffalo. MATERIALS AND METHODS Semen extender was prepared freshly and divided into two sub extenders namely, Extender I: control (non deoxygenated) and Extender II: partially deoxygenated by using LN2 flushing). The estimation of dissolved oxygen (DO) level was done in both extenders. Semen samples with mass motility of ≥ 3+ and individual progressive motility of 70% and above, collected from murrah buffalo bulls were utilized for the present study. Each semen sample was split into two group's viz., group I: diluted with extender I and group II: diluted with extender II up to 60×106 sperm/mL. The diluted semen samples were packed into French mini straws (0.25 mL), sealed with polyvinyl alcohol powder, kept for 3 h at 5°C for equilibration and then kept in automatic programmable freezer until temperature of straws reached -145°C followed by plunging into liquid nitrogen (-196°C). The evaluation of semen samples was carried out for various seminal attributes (sperm motility, live sperm count, acrosomal integrity, and hypo-osmotic swelling (HOS) response) and antioxidant profile (superoxide dismutase (SOD), glutathione peroxidase (GPx) and total antioxidant capacity (TAC)) at pre freeze and post thaw stage. RESULTS Sperm motility, live sperm count, acrosomal integrity, HOS response were significantly (P<0.05) higher in group II as compared to group I. The average seminal SOD, GPx and TAC levels were significantly (P<0.05) higher in group II as compared to group I at pre freeze and post thaw stage. CONCLUSION It is concluded that partial deoxygenation of the extender prior to its addition to semen enhances sperm quality in terms of sperm motility, live sperm count, acrosomal integrity, and hypo-osmotic swelling (HOS) response and also improves seminal antioxidant profile (superoxide dismutase (SOD), glutathione peroxidase (GPx) and total antioxidant capacity (TAC).
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Affiliation(s)
- B Balamurugan
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - S K Ghosh
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - S A Lone
- Artificial Breeding Research Center (ABRC), Animal Reproduction, Gynecology and Obstetrics, ICAR-National Dairy Research Institute, Karnal, Haryana, 132001, India.
| | - J K Prasad
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - G K Das
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - R Katiyar
- Division of Animal Reproduction, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - A R Mustapha
- Department of Theriogenology, Faculty of Veterinary Medicine, University of maiduguri, Borno State, Nigeria
| | - A Kumar
- Biochemistry Division, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India. Division of Livestock Economics and Statistics, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
| | - M R Verma
- Biochemistry Division, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India. Division of Livestock Economics and Statistics, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243122, India
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Kumar MS, Balamurugan B. A Review on Performance Evaluation Techniques in Cloud. 2017 Second International Conference on Recent Trends and Challenges in Computational Models (ICRTCCM) 2017. [DOI: 10.1109/icrtccm.2017.29] [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: 06/16/2023]
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Manivannan M, Narayanan S, Subrayan L, Balamurugan B. Endograft Placement for Iliac Artery Pseudoaneurysm Following Graft Nephrectomy. Indian J Vasc Endovasc Surg 2017. [DOI: 10.4103/0972-0820.198075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Lone SA, Prasad JK, Ghosh SK, Das GK, Balamurugan B, Katiyar R, Verma MR. Effect of incubation on freezability of cholesterol-loaded cyclodextrin treated buffalo (Bubalus bubalis) spermatozoa. Vet World 2016; 9:182-5. [PMID: 27051205 PMCID: PMC4819369 DOI: 10.14202/vetworld.2015.182-185] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 11/16/2022] Open
Abstract
Aim: The aim of this study was to investigate the effect of incubation on freezability of cholesterol loaded cyclodextrin (CLC) treated buffalo spermatozoa. Materials and Methods: Semen samples with mass motility of 3+ and greater, collected from Murrah buffalo bulls were utilized. Immediately after collection, four equal groups of semen sample were made. Group I was kept as control and diluted with Tris upto concentration of 60×106 sperm/ml, where as Groups II, III, and IV were treated with CLC at 3 mg/120× 106 spermatozoa, incubated at 37°C for action of CLC for 10, 15 and 20 min, respectively, and diluted with tris upto concentration of 60×106 sperm/ml. All groups were subjected to equilibration and freezing. The evaluation of semen samples from all groups was carried out at fresh, pre-freeze and post-thaw stage for progressive motility, viability and hypo-osmotic swelling response (HOS response). Results: At the pre-freeze stage, significantly (p<0.05) higher percentage of progressive motility and viability was observed in treatment groups as compared to control with no significant difference among treatment groups. HOS response was significantly (p<0.05) higher in treatment groups as compared to control at pre-freeze stage. At post-thaw stage, significantly (p<0.05) higher percentage of progressive motility, viability and HOS response was recorded in Group II as compared to control and other treatment groups (III and IV). Group II retained significant post-thaw motility and viability at various post-thaw incubation periods. Conclusion: Incubation period of 10 min for CLC treated buffalo spermatozoa yielded significantly higher results in terms of freezability as compared to incubation for 15 and 20 min.
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Affiliation(s)
- S A Lone
- Division of Animal Reproduction, Gynecology & Obstetrics, National Dairy Research Institute, Karnal - 132001, Haryana, India
| | - J K Prasad
- Germplasm Centre, Division of Animal Reproduction, Indian Veterinary Research Institute, Izatnagar, Bareilly - 243122, Uttar Pradesh, India
| | - S K Ghosh
- Germplasm Centre, Division of Animal Reproduction, Indian Veterinary Research Institute, Izatnagar, Bareilly - 243122, Uttar Pradesh, India
| | - G K Das
- Germplasm Centre, Division of Animal Reproduction, Indian Veterinary Research Institute, Izatnagar, Bareilly - 243122, Uttar Pradesh, India
| | - B Balamurugan
- Germplasm Centre, Division of Animal Reproduction, Indian Veterinary Research Institute, Izatnagar, Bareilly - 243122, Uttar Pradesh, India
| | - R Katiyar
- Germplasm Centre, Division of Animal Reproduction, Indian Veterinary Research Institute, Izatnagar, Bareilly - 243122, Uttar Pradesh, India
| | - M R Verma
- Division of Livestock Economics and Statistics, Indian Veterinary Research Institute, Izatnagar, Bareilly - 243122, Uttar Pradesh, India
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Lone SA, Prasad JK, Ghosh SK, Das GK, Balamurugan B, Katiyar R, Verma MR. Effect of incubation on freezability of cholesterol-loaded cyclodextrin treated buffalo (Bubalus bubalis) spermatozoa. Vet World 2016. [DOI: 10.14202/vetworld.2016.182-185] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
STEM images and elemental maps of Mn and Bi showing formation of complex core–shell and three-layer structure.
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Affiliation(s)
- P. Mukherjee
- Physics & Astronomy
- University of Nebraska
- Lincoln
- USA
- Nebraska Center for Materials and Nanoscience
| | - B. Balamurugan
- Physics & Astronomy
- University of Nebraska
- Lincoln
- USA
- Nebraska Center for Materials and Nanoscience
| | - J. E. Shield
- Nebraska Center for Materials and Nanoscience
- University of Nebraska
- Lincoln
- USA
- Mechanical & Materials Engineering
| | - D. J. Sellmyer
- Physics & Astronomy
- University of Nebraska
- Lincoln
- USA
- Nebraska Center for Materials and Nanoscience
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Lone S, Prasad J, Ghosh S, Das G, Balamurugan B, Sheikh A, Katiyar R, Verma M. Activity of Enzymatic Antioxidants and Total Antioxidant Capacity in Seminal Plasma of Murrah Bulls during Cryopreservation. ACTA ACUST UNITED AC 2016. [DOI: 10.5958/2277-940x.2016.00038.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Kumar P, Kashyap A, Balamurugan B, Shield JE, Sellmyer DJ, Skomski R. Permanent magnetism of intermetallic compounds between light and heavy transition-metal elements. J Phys Condens Matter 2014; 26:064209. [PMID: 24469225 DOI: 10.1088/0953-8984/26/6/064209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
First-principle calculations are used to investigate the intrinsic magnetic properties of intermetallic alloys of the type XMn, where X is a 4d or 5d element and M is Fe or Co. Emphasis is on the hexagonal C14 Laves-phase 1:2 and 1:5 alloys, the latter crystallizing in the CaCu5 structure. These series are of interest in permanent magnetism from fundamental and practical viewpoints, respectively. In the former, the unit cells form a prototypical motif where a heavy atom with high spin-orbit coupling and magnetocrystalline anisotropy is surrounded by many somewhat smaller M atoms with high magnetization, and the latter are Laves-phase derivatives of renewed interest in permanent magnetism. Our DFT calculations predict magnetic moments, magnetizations and anisotropies, as well as formation energies. The results are analyzed across the 4d and 5d series, especially with respect to hybridization effects between 3d and 4d/5d bands.
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Balamurugan B, Das B, Zhang WY, Skomski R, Sellmyer DJ. Hf-Co and Zr-Co alloys for rare-earth-free permanent magnets. J Phys Condens Matter 2014; 26:064204. [PMID: 24468962 DOI: 10.1088/0953-8984/26/6/064204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The structural and magnetic properties of nanostructured Co-rich transition-metal alloys, Co(100-x)TMx (TM = Hf, Zr and 10 ≤ x ≤ 18), were investigated. The alloys were prepared under non-equilibrium conditions using cluster-deposition and/or melt-spinning methods. The high-anisotropy HfCo7 and Zr2Co11 structures were formed for a rather broad composition region as compared to the equilibrium bulk phase diagrams, and exhibit high Curie temperatures of above 750 K. The composition, crystal structure, particle size, and easy-axis distribution were precisely controlled to achieve a substantial coercivity and magnetization in the nanostructured alloys. This translates into high energy products in the range of about 4.3-12.6 MGOe, which are comparable to those of alnico.
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Wei XH, Zhou R, Balamurugan B, Skomski R, Zeng XC, Sellmyer DJ. Experimental and theoretical studies of hydroxyl-induced magnetism in TiO nanoclusters. Nanoscale 2012; 4:7704-7711. [PMID: 23132145 DOI: 10.1039/c2nr32858e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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
A main challenge in understanding the defect ferromagnetism in dilute magnetic oxides is the direct experimental verification of the presence of a particular kind of defect and distinguishing its magnetic contributions from other defects. The magnetic effect of hydroxyls on TiO nanoclusters has been studied by measuring the evolution of the magnetic moment as a function of moisture exposure time, which increases the hydroxyl concentration. Our combined experiment and density-functional theory (DFT) calculations show that as dissociative water adsorption transforms oxygen vacancies into hydroxyls, the magnetic moment shows a significant increase. DFT calculations show that the magnetic moment created by hydroxyls arises from 3d orbitals of neighboring Ti sites predominantly from the top and second monolayers. The two nonequivalent hydroxyls contribute differently to the magnetic moment, which decreases as the separation of hydroxyls increases. This work illustrates the essential interplay among defect structure, local structural relaxation, charge redistribution, and magnetism. The microscopic differentiation and clarification of the specific roles of each kind of intrinsic defect is critical for the future applications of dilute magnetic oxides in spintronic or other multifunctional materials.
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Affiliation(s)
- Xiao-hui Wei
- Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USA
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Skomski R, Balamurugan B, Schubert E, Enders A, Sellmyer DJ. Length scales of interactions in magnetic, dielectric, and mechanical nanocomposites. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/opl.2011.109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTIt is investigated how figures of merits of nanocomposites are affected by structural and interaction length scales. Aside from macroscopic effects without characteristic lengths scales and atomic-scale quantum-mechanical interactions there are nanoscale interactions that reflect a competition between different energy contributions. We consider three systems, namely dielectric media, carbon-black reinforced rubbers and magnetic composites. In all cases, it is relatively easy to determine effective materials constants, which do not involve specific length scales. Nucleation and breakdown phenomena tend to occur on a nanoscale and yield a logarithmic dependence of figures of merit on the macroscopic system size. Essential system-specific differences arise because figures of merits are generally nonlinear energy integrals. Furthermore, different physical interactions yield different length scales. For example, the interaction in magnetic hard-soft composites reflects the competition between relativistic anisotropy and nonrelativistic exchange interactions, but such hierarchies of interactions are more difficult to establish in mechanical polymer composites and dielectrics.
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Balamurugan B, Thirumarimurugan M, Kannadasan T. Anaerobic degradation of textile dye bath effluent using Halomonas sp. Bioresour Technol 2011; 102:6365-6369. [PMID: 21463931 DOI: 10.1016/j.biortech.2011.03.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 03/03/2011] [Accepted: 03/07/2011] [Indexed: 05/30/2023]
Abstract
The main objective of this work is to reduce the chemical oxygen demand (COD) and color of the effluent containing reactive textile dye by microbial method. Anaerobic digestion has the potential to break down complex refractory organic compounds so that they may be further degraded aerobically or to completely mineralize them. An anaerobic digestion technique was applied to synthetic reactive red 2 dye cotton textile effluent aiming at the dye degradation. Halophilic and halotolerant bacterial culture Halomonas variabilis and Halomonas glaciei were used for degradation in batch-mode static condition. The temperature was kept constant at 30°C using CO(2) incubator. Maximum degradation was achieved within 144 h of experimental run. Degradation studies were made by determining COD and biochemical oxygen demand (BOD). Statistical analysis showed that the BOD and COD reduction rate were optimal in the concentration of 1297 mg L(-1) for the time duration of nearly 100 h.
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Affiliation(s)
- B Balamurugan
- Department of Biotechnology and Chemical Engineering, Kalasalingam University, Anand Nagar, Krishnankoil 626126, India.
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Balamurugan B, Roshan MNAM, Shaahul Hameed B, Sumathi K, Senthilkumar R, Udayakumar A, Venkatesh Babu KH, Kalaivani M, Sowmiya G, Sivasankari P, Saravanan S, Vasuki Ranjani C, Gopalakrishnan K, Selvakumar KN, Jaikumar M, Brindha T, Michael D, Sekar K. PSAP: protein structure analysis package. J Appl Crystallogr 2007. [DOI: 10.1107/s0021889807021875] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A computing engine, theProtein Structure Analysis Package(PSAP), has been developed to calculate and display various hidden structural and functional features of three-dimensional protein structures. The proposed computing engine has several utilities to enable structural biologists to analyze three-dimensional protein molecules and provides an easy-to-use Web interface to compute and visualize the necessary features dynamically on the client machine. Users need to provide the Protein Data Bank (PDB) identification code or upload three-dimensional atomic coordinates from the client machine. For visualization, the free molecular graphics programsRasMolandJmolare deployed in the computing engine. Furthermore, the computing engine is interfaced with an up-to-date local copy of the PDB. The atomic coordinates are updated every week and hence users can access all the structures available in the PDB. The computing engine is free and is accessible online at http://iris.physics.iisc.ernet.in/psap/.
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Samaya Mohan K, Sheik SS, Ramesh J, Balamurugan B, Jeyasimhan M, Mayilarasi C, Sekar K. CADB-2.0: Conformation Angles Database. Acta Crystallogr D Biol Cryst 2005; 61:637-9. [PMID: 15858276 DOI: 10.1107/s0907444905005871] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Accepted: 02/23/2005] [Indexed: 11/10/2022]
Abstract
The Conformation Angles Data Base (CADB) is a comprehensive, authoritative and timely knowledge base with a powerful query engine developed to facilitate the retrieval of information related to the conformational angles (main chain and side chain) of the amino-acid residues present in non-redundant (both 25 and 90%) data sets. The updated version has improved options for determining the dependency of the conformation angles of a particular residue upon the flanking residues, doublet analysis, triplet analysis and analysis of a particular protein structure. It is worth mentioning that for all options a user-friendly and convenient Java graphical user interface (GUI) has been provided to display the output on the client machine. The database is accessible at the URL http://cluster.physics.iisc.ernet.in/cadb/ or http://144.16.71.148/cadb/.
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Affiliation(s)
- K Samaya Mohan
- Bioinformatics Centre, Indian Institute of Science, Bangalore 560 012, India
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Balamurugan B, Samaya Mohan K, Ramesh J, Roshan MNAM, Sumathi K, Sekar K. SSEP-2.0: Secondary Structural Elements of Proteins. Acta Crystallogr D Biol Crystallogr 2005; 61:634-6. [PMID: 15858275 DOI: 10.1107/s0907444905005883] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Accepted: 02/23/2005] [Indexed: 11/10/2022]
Abstract
The Secondary Structural Elements of Proteins (SSEP) database is an integrated and comprehensive knowledge base for accessing information related to all the secondary-structural elements present in non-redundant (25 and 90%) protein chains. The new version 2.0 of the database contains 2485 and 8595 protein chains from the 25 and 90% non-redundant data sets, respectively. The necessary web interfaces have been developed that enable users to visualize the three-dimensional structure of the secondary-structural element in the client machine using the free molecular-visualization program RASMOL. This source is updated at regular intervals and can be accessed through the bioinformatics web server at the URL http://cluster.physics.iisc.ernet.in/ssep or http://144.16.71.148/ssep/.
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Affiliation(s)
- B Balamurugan
- Bioinformatics Centre, Indian Institute of Science, Bangalore 560 012, India
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