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Fulltext Computational identification and binding analysis of orphan human cytochrome P450 4X1 enzyme with substrates

Kumar S

BMC Res Notes, 2015;8:9.
PMID: 25595103 DOI: 10.1186/s13104-015-0976-4

Cytochrome P450s (CYPs) are important heme-containing proteins, well known for their monooxygenase reaction. The human cytochrome P450 4X1 (CYP4X1) is categorized as "orphan" CYP because of its unknown function. In recent studies it is found that this enzyme is expressed in neurovascular functions of the brain. Also, various studies have found the expression and activity of orphan human cytochrome P450 4X1 in cancer. It is found to be a potential drug target for cancer therapy. However, three-dimensional structure, the active site topology and substrate specificity of CYP4X1 remain unclear.
Fulltext Computational comparisons of LipL21 mRNA and amino acids conserved sequences in Leptospira strains

Sharani, R., Kumar, S., Thilakavathy, K.

Malaysian Journal of Medicine and Health Sciences, 2019;15(102):8-8.
MyJurnal

Introduction: Lipoprotein L21 (LipL21) has been used as a molecular marker for leptospirosis as it is highly expressed in pathogenic Leptospira species during infection. However, it lacks specificity due to the newly emerging pathogenic serovars. Therefore, interrogation of LipL21 in all serovars needed to understand the pathogenesis of leptospirosis to enable early diagnosis. This study was carried out to determine the suitability of LipL21 as a molecular marker for leptospirosis by identifying the conserved sequences of LipL21 mRNA and amino acids in different Leptospira strains. Methods: Location of LipL21 conserved regions in 15 pathogenic and 2 non-pathogenic strains of five Leptospira species, were identified using bioinformatics database and tools such as National Center of Biotechnology, Rapid Annotation Subsystem Technology blast search, Muscle program and Jalview software. Results: Multiple sequence alignment analysis revealed that two conserved regions were observed in 10 pathogenic Leptospira strains from nucleotide position 29 to 53 and 100 to 137, however conserved amino acid sequences (111-149 and 155-192) were found in all the pathogenic strains. The distinction between gene and amino acid results is due to the degenerate genetic code feature. Conclusion: In conclusion, this study suggests that LipL21 protein has a potential to be used as a diagnostic marker for detection of Leptospira pathogens compared to LipL21 mRNA.
Offspring's labor migration and its implications for elderly parents' emotional wellbeing in Indonesia

Kumar S

Soc Sci Med, 2021 05;276:113832.
PMID: 33784552 DOI: 10.1016/j.socscimed.2021.113832

Population ageing and labor out-migration are increasingly challenging normative intergenerational support systems and familial welfare in parts of Asia. Extant studies look at how migration affects the material wellbeing of sending-households, but less is known about how migration shapes the emotional health of non-migrants as origin and destination conditions evolve. This study examines how labor migration among adult children shape the emotional health of elderly parents in Indonesia, and how observed implications are modified by alternative care arrangements and different migrant destinations. Using panel data from 2101 respondents age 50+ in the 2007 and 2014 Indonesia Family Life Survey, and individual-level fixed effects regressions, this study finds that offspring's migration is associated with increased parental depression, net of covariates. Depressive outcomes are abated if resulting care deficits are offset by co-residence or daily interactions with adult children, or if children move to economically lucrative international destinations; however, having a child in Malaysia - a destination characterized by high informal labor employment - increased parental depression. These findings draw attention to the non-economic implications of migration and the distress experienced specifically by parents who lack intergenerational support and who have concerns about child's wellbeing at destination.
Fulltext Congenital renal anomalies - a dissection observational study

Bilodi, Arun Kumar .S, Gangadhar, M R

Malaysian Journal of Medical Research, 2017;1(1):14-18.
MyJurnal

Anomaly is a congenital disorder. It is a medical condition that is present since birth. But the word congenital neither applies nor excludes genetic disorder. Congenital anomalies due to environmental factors are called as Teratogens. Infections, deficiency in the diet and toxins are environmental causes. Maternal folic acid deficiency may cause spina bifida. Intake of alcohol, and certain prescribed drugs like phenytoin may cause congenital anomalies or defects. Apart from physical anomalies, other types of congenital disorders are inborn errors of metabolism (Kumar, Abbas and Fausto, 2005). About 15% to 25% of anomalies are due to chromosomal factors or single gene factors, 8% to 12% anomalies are said to be due to environmental factors, 25% are said to be due to multifactorial inheritance 40% to 60% of anomalies are of unknown origin (Stevenson, 1993 ; Nelson and Holmes, 1984). Congenital anomalies are present since birth with structural deformity found immediately after birth or their presence may be detected by signs and symptoms later on (Holland and Brew, 1991). Congenital Anomalies are seen in 2% of population as major abnormality. There are two types of abnormalities, namely malformations where growth disturbances occur during embryogenesis and the other is deformation. It is late change that appears in a structure which was normal earlier (Roizen and Patterson, 2003).
Fulltext Prediction of Metal Ion Binding Sites in Proteins from Amino Acid Sequences by Using Simplified Amino Acid Alphabets and Random Forest Model

Kumar S

Genomics Inform, 2017 Dec;15(4):162-169.
PMID: 29307143 DOI: 10.5808/GI.2017.15.4.162

Metal binding proteins or metallo-proteins are important for the stability of the protein and also serve as co-factors in various functions like controlling metabolism, regulating signal transport, and metal homeostasis. In structural genomics, prediction of metal binding proteins help in the selection of suitable growth medium for overexpression's studies and also help in obtaining the functional protein. Computational prediction using machine learning approach has been widely used in various fields of bioinformatics based on the fact all the information contains in amino acid sequence. In this study, random forest machine learning prediction systems were deployed with simplified amino acid for prediction of individual major metal ion binding sites like copper, calcium, cobalt, iron, magnesium, manganese, nickel, and zinc.
Fulltext Structure and functional annotation of hypothetical proteins having putative Rubisco activase function from Vitis vinifera

Kumar S

Bioinformation, 2015;11(1):11-6.
PMID: 25780274 DOI: 10.6026/97320630011011

Rubisco is a very large, complex and one of the most abundant proteins in the world and comprises up to 50% of all soluble protein in plants. The activity of Rubisco, the enzyme that catalyzes CO2 assimilation in photosynthesis, is regulated by Rubisco activase (Rca). In the present study, we searched for hypothetical protein of Vitis vinifera which has putative Rubisco activase function. The Arabidopsis and tobacco Rubisco activase protein sequences were used as seed sequences to search against Vitis vinifera in UniprotKB database. The selected hypothetical proteins of Vitis vinifera were subjected to sequence, structural and functional annotation. Subcellular localization predictions suggested it to be cytoplasmic protein. Homology modelling was used to define the three-dimensional (3D) structure of selected hypothetical proteins of Vitis vinifera. Template search revealed that all the hypothetical proteins share more than 80% sequence identity with structure of green-type Rubisco activase from tobacco, indicating proteins are evolutionary conserved. The homology modelling was generated using SWISS-MODEL. Several quality assessment and validation parameters computed indicated that homology models are reliable. Further, functional annotation through PFAM, CATH, SUPERFAMILY, CDART suggested that selected hypothetical proteins of Vitis vinifera contain ATPase family associated with various cellular activities (AAA) and belong to the AAA+ super family of ring-shaped P-loop containing nucleoside triphosphate hydrolases. This study will lead to research in the optimization of the functionality of Rubisco which has large implication in the improvement of plant productivity and resource use efficiency.
Ultrastructural changes during asexual multiple reproduction in Trichomonas vaginalis

Yusof A, Kumar S

Parasitol Res, 2012 May;110(5):1823-8.
PMID: 22076052 DOI: 10.1007/s00436-011-2705-9

Trichomonas vaginalis, a flagellated protozoan parasite, is commonly found in the genitourinary tract of humans. Its mode of reproduction has always been reported to be binary fission. The high parasite numbers seen in a relatively short period in in vitro cultures led us to believe that there must be other modes of reproduction. The present study for the first time provides transformational evidence at the ultrastructural level seen in tropohozoites of T. vaginalis undergoing a multiple asexual mode of reproduction. The findings show that the single cell with a nucleus is capable of dividing to as many as eight nuclei within the cytoplasmic body. Before the commencement of division, the nucleus remained round or ovoid in shape with condensed chromatin masses and only a few endoplasmic reticula surrounding the nucleus. During the division, the nucleus started to elongate and become irregular in shape with visible chromatin masses condensing with the accumulation of numerous endoplasmic reticula. Nuclear division gave rise to as many as eight nuclei within a cell, which could be seen to be connected by numerous endoplasmic reticula. In addition, a high number of hydrogenosomes and vacuoles can be seen in multinucleated T. vaginalis compared with single nucleated T. vaginalis. This study confirms that multiple modes of nuclear division do exist in T. vaginalis and are a precursor to progeny formation.
Fulltext Association of physical activity score with cardio-pulmonary function parameters and VO2 max in healthy young adults of Sabah, Malaysia

Urban John Arnold D’Souza, Vinod Kumar S., Nagesh Chodankar

Malaysian Journal of Medicine and Health Sciences, 2019;15(106):46-46.
MyJurnal

Introduction: Regular physical activity and VO2 max are correlated directly. Physical anthropometry physical ac-tivity, lung function and cardiac parameters such as systolic, diastolic blood pressure and resting heart rate are the important baseline parameters in relation to the a healthy life. In this study, a comprehensive determination of these parameters were planned among the common ethnicities of Sabah. This study in turn aims at making the sedentary people to make physically active and implicate a possible relationship between cardio-respiratory parameters with the physical activity levels. Methods: A total of 385 young adult Sabah, Malaysia college students with n=148 males and n= 237 females were randomly selected from the different colleges in Kota Kinabalu. Ethical clearance was received from Faculty of Medicine & Health Sciences UMS, and the participants were briefed on the procedures with their voluntary consent. IPAQ-Score/Met-Min/Week, BMI, resting heart rate, blood pressure, lung function parameters – forced vital capacity, peak expiratory flow rate etc were estimated by standard techniques. Data was analyzed, a regression analysis and ANOVA was performed to assess the relationship between independent and dependent variables. Results: Physical activity level has a significant correlation with the dependent variables of this study. VO2max is significantly and inversely related to body weight, BMI, blood pressure and pulse rate, whereas physical activity level is directly correlated. A weak positive correlation for VO2 max with lung function parameters.Conclusion: Physical activity, VO2 max and cardio-respiratory parameters; interdependently correlated and regular activity contributed to the rate of oxygen consumption.
Fulltext Molecular genetic approaches for the conservation of endangered orchids

Rodrigues, K. F., Yeoh, K. A., Kumar, S. V.

Buletin Persatuan Genetik Malaysia, 2006;12(1):13-14.
MyJurnal

Geographically isolated populations of endemic orchids have evolved and adapted to an existence within specifi c ecological niches. These populations are highly susceptible to anthropogenic
infl uences on their microhabitats. The primary objective of conservation programs is the restoration of endangered populations to their ecologically sustainable levels, and the fi rst stage in the process of conservation involves estimation of molecular diversity at the level of the population. The approach described in this article involves the application of RAPD, Microsatellites and Chloroplast DNA markers for the characterization of the genetic structure of Paphiopedilum rothschildianum and Phalaenopsis gigantea, two endangered and endemic orchids of Sabah. This study has isolated a total of 96 microsatellite loci in P. rothschildianum and P. gigantea, 42 specifi c primer pairs have been designed for amplifi cation of microsatellite loci and are currently being applied to screen the breeding pools. The Chloroplast DNA regions amplifi ed by the primer pairs trnH-psbA and trnL-trnF exhibit distinct polymorphisms and can be used to establish phylogenetic
relationships. The ability of microsatellite loci to cross-amplify selected varieties of orchids has been determined. The molecular markers developed will be applied to estimate population diversity
levels and to formulate long-term management strategies for the conservation of endangered species of orchids of Sabah.
Fulltext Lipid Peroxidation in Chronic Cerebral HypoperfusionInduced Neurodegeneration in Rats

Anil Kumar, S., Saif, S.A., Oothuman, P., Mustafa, M.I.A.

International Medical Journal Malaysia, 2011;10(2):3-6.
MyJurnal

Introduction: Reduced cerebral blood ﬂ ow is associated with neurodegenerative disorders and dementia, in particular. Experimental evidence has demonstrated the initiating role of chronic cerebral hypoperfusion in neuronal damage to the hippocampus, the cerebral cortex, the white matter areas and the visual system. Permanent, bilateral occlusion of the common carotid arteries of rats (two vessel occlusion - 2VO) has been introduced for the reproduction of chronic cerebral hypoperfusion as it occurs in Alzheimer’s disease and human aging. Increased generation of free radicals through lipid peroxidation can damage neuronal cell membrane. Markers of lipid peroxidation have been found to be elevated in brain tissues and body ﬂ uids in neurodegenerative diseases, including Alzheimer’s disease, Parkinson disease and amyotrophic lateral sclerosis. Materials and Methods: Malondialdehyde (MDA), ﬁ nal product of lipid peroxidation, was estimated by thiobarbituric acid-reactive substances (TBARS) assay kit at eight weeks after induction of 2VO in the rats and control group. Results: Our study revealed a highly signiﬁ cant (p
Fulltext Perceptions of Scholars in the Field of Economics on Co-Authorship Associations: Evidence from an International Survey

Kumar S, Ratnavelu K

PLoS One, 2016;11(6):e0157633.
PMID: 27322645 DOI: 10.1371/journal.pone.0157633

Scholars (n = 580) from 69 countries who had contributed articles in the field of Economics during the year 2015 participated in a survey that gauged their perceptions of various aspects of co-authorship, including its benefits, motivations, working relationships, order of authorship and association preferences. Among the main findings, significant differences emerged in the proportion of co-authored papers based on age, gender and number of years the researchers had spent in their present institution. Female scholars had a greater proportion of co-authored papers than male scholars. Respondents considered improved quality of paper, contribution of mutual expertise, and division of labor as the biggest benefits of and motivation for co-authorship. Contrary to common perceptions that Economics researchers used a predominantly alphabetical order of authorship, our study found that a considerable percentage of respondents (34.5%) had practiced an order of authorship based on the significance of the authors' contribution to the work. The relative importance of tasks differed significantly according to whether researchers co-authored as mentors or co-authored as colleagues. Lastly, researchers were found to associate, to varying degrees, with other researchers based on socio-academic parameters, such as nationality, ethnicity, gender, professional position and friendship. The study indicates that Economics authors perceive co-authorship as a rewarding endeavor. Nonetheless, the level of contribution and even the choice of association itself as a co-author depends to a great extent on the type of working relationship and socio-academic factors.
Phenotypic 'variant' forms of Trichomonas vaginalis trophozoites from cervical neoplasia patients

Yusof AM, Kumar S

Exp Parasitol, 2012 Jul;131(3):267-73.
PMID: 22525014 DOI: 10.1016/j.exppara.2012.03.015

The protozoan Trichomonas vaginalis a sexually transmitted protozoan parasite causes vaginitis, urethritis and cervicitis in humans. The present study highlights phenotypic 'variant' forms of trophozoites isolated from patients suffering from cervical neoplasia condition. The growth curve of 10 isolates i.e., four non-cervical neoplasia (NCN) isolates (NCN1-NCN4) and six cervical neoplasia (CN) isolates (CN1-CN6) showed two distinct and different in vitro growth profiles. The parasite count and growth rates were significantly higher in trophozoites from CN isolates in cultures of day 2 up to day 8 (p<0.05, Mann-Whitney test). The average generation time was 1.84±0.40 and 3.38±0.55h for NCN and CN isolates respectively. The nucleus of trophozoites in CN isolates using acridine orange and DAPI showed more intense staining revealing higher nuclear content. The FITC-labeled Concanavalin A stained stronger green fluorescence with surface of trophozoites in CN isolates showing more rough and creased surface with numerous deep micropores. Transmission electron microscopy studies revealed that there was higher numbers of vacuoles and hydrogenosomes in these forms. The study mounted staining techniques, growth profiles, morphology, morphometry studies using scanning and transmission electron microscopy and confirms that the trophozoites from cervical neoplasia proliferates at a higher rate, shows higher FITC-labeled Concanavalin A binding with rough and creased surface implying that these are virulent forms which can aggravate or exacerbate cervical neoplasia conditions. The large numbers of hyrogenosomes and vacuoles implies that these forms are active and implicates a possible role in such conditions.
Spontaneous pneumoperitoneum associated with colonic pseudo-obstruction

Prasannan S, Kumar S, Gul YA

Acta Chir. Belg., 2005 1 25;104(6):739-41.
PMID: 15663288

Pneumoperitoneum is almost always pathognomonic of a perforated abdominal viscus requiring urgent surgical intervention. Spontaneous or non-surgical pneumoperitoneum is a rare clinical condition arising secondary to abdominal, thoracic, gynaecologic or idiopathic causes. In addition to good clinical judgement, an important component in the management process is to rule out other causes of pneumoperitoneum by performing appropriate investigations. We describe a 60-year-old man who presented with clinical features of pseudo-obstruction, following an injury to his back which was compounded by hypokalaemia. Roentgenography revealed massive pneumoperitoneum and colonic distension. As there were no overt clinical features of peritonitis, the patient was managed conservatively with parenteral nutrition and close observation. A water-soluble contrast enema and computed tomography of the abdomen were of no help in identifying the cause of his pneumoperitoneum but were helpful in eliminating the presence of hollow viscus perforation or an obvious inflammatory focus. The aetiology of pneumoperitoneum in our patient was most likely due to dissection of air through the distended colonic wall, secondary to large bowel pseudo-obstruction. The diagnosis of spontaneous or non-surgical pneumoperitoneum is one of exclusion and we stress the importance of relying on clinical parameters when managing such patients conservatively.
Anti-obesity effects of galangin, a pancreatic lipase inhibitor in cafeteria diet fed female rats

Kumar S, Alagawadi KR

Pharm Biol, 2013 May;51(5):607-13.
PMID: 23363068 DOI: 10.3109/13880209.2012.757327

Context: Alpinia galanga Willd (Zingiberaceae) (AG) is a rhizomatous herb widely cultivated in shady regions of Malaysia, India, Indochina and Indonesia. It is used in southern India as a domestic remedy for the treatment of rheumatoid arthritis, cough, asthma, obesity, diabetes, etc. It was reported to have anti-obesity, hypoglycemic, hypolipidemic and antioxidant properties.

Objective: A flavonol glycoside, galangin, was isolated from AG rhizomes. Based on its in vitro pancreatic lipase inhibitory effect, the study was further aimed to clarify whether galangin prevented obesity induced in female rats by feeding cafeteria diet (CD) for 6 weeks.

Materials and methods: The in vitro pancreatic lipase inhibitory effect of galangin was determined by measuring the release of oleic acid from triolein. For in vivo experiments, female albino rats were fed CD with or without 50 mg/kg galangin for 6 weeks. Body weight and food intake was measured at weekly intervals. On day 42, serum lipids levels were estimated and then the weight of liver and parametrial adipose tissue (PAT) was determined. The liver lipid peroxidation and triglyceride (TG) content was also estimated.

Results: The IC50 value of galangin for pancreatic lipase was 48.20 mg/mL. Galangin produced inhibition of increased body weight, energy intake and PAT weight induced by CD. In addition, galangin produced a significant decrease in serum lipids, liver weight, lipid peroxidation and accumulation of hepatic TGs.

Conclusion: Galangin present in AG rhizomes produces anti-obesity effects in CD-fed rats; this may be mediated through its pancreatic lipase inhibitory, hypolipidemic and antioxidant activities.
HHV-6 antigen and viral DNA detected in cervical cells from archived tissue using histochemical staining and hybridization

Yadav M, Arivananthan M, Kumar S

Clin Diagn Virol, 1996 Oct;7(1):23-33.
PMID: 9077427

BACKGROUND: Human herpesvirus type 6 (HHV-6), an ubiquitous virus, is the causative agent for exanthem subitum. The virus is frequently associated with lymphoproliferative disorders and other diseases. Recently, we have reported the frequent presence of HHV-6 in oral carcinoma and the present study extends the observation to cervical carcinoma.
OBJECTIVE: To examine the presence of HHV-6 in cervical carcinoma.
STUDY DESIGN: Formalin-fixed, paraffin-embedded cervical carcinoma tissues were examined for the presence of HHV-6 by immunohistochemistry using two monoclonal antibodies that react to HHV-6-encoded p41/38 and gp116/64/54. In situ hybridization with variant-specific probes were used to type the HHV-6 DNA sequences present.
RESULTS: A total of 14/26 (53.9%) carcinoma tissue specimens and 5/8 (62.5%) normal tissue specimens were positive for viral antigens. In situ hybridization studies revealed the presence of HHV-6 DNA sequences in 10/26 (38.5%) carcinoma tissue specimens and 1/8 (12.5%) normal tissue specimens. In the normal tissue, the HHV-6 was present in the endocervical ciliated columnar-epithelial cells and some cells in the subepithelial mucosa but in the carcinoma, the transformed cells were positive for the virus.
CONCLUSIONS: HHV-6 viral proteins and DNA were found in more than one third of the cervical tissue examined suggesting possible viral expression in these tumours. The significance of the distribution and role of the HHV-6 in cervical tissue remains unclear. Since HHV-6 has an oncogenic potential, the virus may cooperate with other transforming agents for the progression of the disease.
Chitin nanocrystals based complex fluids: A green nanotechnology

Kumar S, Foroozesh J

Carbohydr Polym, 2021 Apr 01;257:117619.
PMID: 33541647 DOI: 10.1016/j.carbpol.2021.117619

Chitin biopolymer has received significant attention recently by many industries as a green technology. Nanotechnology has been used to make chitin nanocrystals (ChiNCs) that are rod-shaped natural nanomaterials with nanoscale size. Owing to the unique features such as biodegradability, biocompatibility, renewability, rod-shape, and excellent surface and interfacial, physiochemical, and thermo-mechanical properties; ChiNCs have been green and attractive products with wide applications specifically in medical and pharmaceutical, food and packaging, cosmetic, electrical, and electronic, and also in the oil and gas industry. This review aims to give a comprehensive and applied insight into ChiNCs technology. It starts with reviewing different sources of chitin and their extraction methods followed by the characterization of ChiNCs. Furthermore, a detailed investigation into various complex fluids (dispersions, emulsions, foams, and gels) stabilized by ChiNCs and their characterisation have been thoroughly deliberated. Finally, the current status including ground-breaking applications, untapped investigations, and future prospective have been presented.
Fulltext Prediction of hub genes of Alzheimer's disease using a protein interaction network and functional enrichment analysis

Wee JJ, Kumar S

Genomics Inform, 2020 Dec;18(4):e39.
PMID: 33412755 DOI: 10.5808/GI.2020.18.4.e39

Alzheimer's disease (AD) is a chronic, progressive brain disorder that slowly destroys affected individuals' memory and reasoning faculties, and consequently, their ability to perform the simplest tasks. This study investigated the hub genes of AD. Proteins interact with other proteins and non-protein molecules, and these interactions play an important role in understanding protein function. Computational methods are useful for understanding biological problems, in particular, network analyses of protein-protein interactions. Through a protein network analysis, we identified the following top 10 hub genes associated with AD: PTGER3, C3AR1, NPY, ADCY2, CXCL12, CCR5, MTNR1A, CNR2, GRM2, and CXCL8. Through gene enrichment, it was identified that most gene functions could be classified as integral to the plasma membrane, G-protein coupled receptor activity, and cell communication under gene ontology, as well as involvement in signal transduction pathways. Based on the convergent functional genomics ranking, the prioritized genes were NPY, CXCL12, CCR5, and CNR2.
Fulltext Antioxidant activity in children with ADHD – a comparison in untreated and treated subjects with normal children

Ruchi, K., Anil Kumar, S., Sunil, G., Bashir, A., Prabhat, S.

International Medical Journal Malaysia, 2011;10(1):31-35.
MyJurnal

Introduction: Attention deficit hyperactivity disorder (ADHD) is a frequently encountered clinical condition in children. Based on DSM IV-TR criteria it can be sub-classified into three distinct types namely hyperactiveimpulsive, inattentive and combined. Materials and Methods: In the present study, salivary antioxidant activity (AOA) in children with ADHD was compared with age-matched normal control subjects, both as a whole and also with regard to the three subtypes. Additionally, the effect of therapy on the altered AOA levels was investigated following short term (
Fulltext Bonded-communities in HantaVirus research: a research collaboration network (RCN) analysis

Kumar S, Markscheffel B

Scientometrics, 2016;109(1):533-550.
PMID: 32287514 DOI: 10.1007/s11192-016-1942-1

Hantavirus, one of the deadliest viruses known to humans, hospitalizes tens of thousands of people each year in Asia, Europe and the Americas. Transmitted by infected rodents and their excreta, Hantavirus are identified as etiologic agents of two main types of diseases-Hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome, the latter having a fatality rate of above 40 %. Although considerable research for over two decades has been going on in this area, bibliometric studies to gauge the state of research of this field have been rare. An analysis of 2631 articles, extracted from WoS databases on Hantavirus between 1980 and 2014, indicated a progressive increase (R2 = 0.93) in the number of papers over the years, with the majority of papers being published in the USA and Europe. About 95 % papers were co-authored and the most common arrangement was 4-6 authors per paper. Co-authorship has seen a steady increase (R2 = 0.57) over the years. We apply research collaboration network analysis to investigate the best-connected authors in the field. The author-based networks have 49 components (connected clump of nodes) with 7373 vertices (authors) and 49,747 edges (co-author associations) between them. The giant component (the largest component) is healthy, occupying 84.19 % or 6208 vertices with 47,117 edges between them. By using edge-weight threshold, we drill down into the network to reveal bonded communities. We find three communities' hotspots-one, led by researchers at University of Helsinki, Finland; a second, led by the Centers of Disease Control and Prevention, USA; and a third, led by Hokkaido University, Japan. Significant correlation was found between author's structural position in the network and research performance, thus further supporting a well-studied phenomenon that centrality effects research productivity. However, it was the PageRank centrality that out-performed degree and betweenness centrality in its strength of correlation with research performance.
Diethanolamine-modified pectin based core-shell composites as dual working gastroretentive drug-cargo

Bera H, Kumar S

Int J Biol Macromol, 2018 Mar;108:1053-1062.
PMID: 29122714 DOI: 10.1016/j.ijbiomac.2017.11.019

The current study aimed at developing diethonolamine-modified high-methoxyl pectin (DMP)-alginate (ALG) based core-shell composites for controlled intragastric delivery of metformin HCl (MFM) by combined approach of floating and bioadhesion. DMP with degree of amidation of 48.72% was initially accomplished and characterized by FTIR, DSC and XRD analyses. MFM-loaded core matrices were then fabricated by ionotropic gelation technique employing zinc acetate as cross-linker. The core matrices were further coated by fenugreek gum (FG)-ALG gel membrane via diffusion-controlled interfacial complexation method. Various formulations demonstrated excellent drug encapsulation efficiency (DEE, 51-70%) and sustained drug eluting behavior (Q8h, 72-96%), which were extremely influenced by polymer-blend (ALG:DMP) ratios, low density additives (olive oil/magnesium stearate) and FG-ALG coating inclusion. The drug release profile of the core-shell matrices (F-7) was best fitted in zero-order kinetic model with case-II transport driven mechanism. It also portrayed outstanding gastroretentive characteristics. Moreover, the composites were analyzed for surface morphology, drug-excipients compatibility, thermal behavior and drug crystallinity. Thus, the developed composites are appropriate for controlled stomach-specific delivery of MFM for type 2 diabetes management.

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