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2.
PLoS One ; 18(11): e0294056, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37943783

RESUMO

Common species often play vital roles in ecosystem functions and processes. Globally, conservation strategies are mostly focused on threatened species and rarely explored the potential of using common species as indicators of critical ecosystems. The Himalayan mountains have unique riverine ecosystems harbouring high diversity of specialist river birds. Ecological niche modelling provides effective tools to predict suitable habitats of a species and identify habitats for conservation. We used two common water-dependent bird species, Blue Whistling Thrush and White-capped Water Redstart as indicators of riverine ecosystems within the Sikkim Himalayan region and predicted their suitable habitats using an ensemble modelling approach. We selected six predictor variables for the final model including three bioclimatic and three topographic variables. For both species, bioclimatic variables such as mean annual temperature and precipitation were the most important factors compared to topographic variables. At least 70 percent of the most suitable habitats are distributed below 2000 m elevation alongside major drainages. Also, most of their potential habitats are distributed outside the protected area networks in the region. This habitat suitability pattern may be applied to other sympatric species in the region. Since major water bodies in Sikkim are largely affected by developmental activities and climate change, these riverine birds might face threats of losing suitable habitats. We recommend a dynamic approach to evaluate the habitat quality of riverine birds, especially outside protected area networks in the region to plan conservation strategies. This approach will ensure habitat conservation of many water-dependent birds and other taxa associated with the riverine ecosystems of the Eastern Himalaya.


Assuntos
Ecossistema , Aves Canoras , Animais , Água , Conservação dos Recursos Naturais , Índia
3.
Front Microbiol ; 14: 1204428, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37434702

RESUMO

Staphylococcus aureus is one of the most common opportunistic human pathogens causing several infectious diseases. Ever since the emergence of the first methicillin-resistant Staphylococcus aureus (MRSA) strain decades back, the organism has been a major cause of hospital-acquired infections (HA-MRSA). The spread of this pathogen across the community led to the emergence of a more virulent subtype of the strain, i.e., Community acquired Methicillin resistant Staphylococcus aureus (CA-MRSA). Hence, WHO has declared Staphylococcus aureus as a high-priority pathogen. MRSA pathogenesis is remarkable because of the ability of this "superbug" to form robust biofilm both in vivo and in vitro by the formation of polysaccharide intercellular adhesin (PIA), extracellular DNA (eDNA), wall teichoic acids (WTAs), and capsule (CP), which are major components that impart stability to a biofilm. On the other hand, secretion of a diverse array of virulence factors such as hemolysins, leukotoxins, enterotoxins, and Protein A regulated by agr and sae two-component systems (TCS) aids in combating host immune response. The up- and downregulation of adhesion genes involved in biofilm formation and genes responsible for synthesizing virulence factors during different stages of infection act as a genetic regulatory see-saw in the pathogenesis of MRSA. This review provides insight into the evolution and pathogenesis of MRSA infections with a focus on genetic regulation of biofilm formation and virulence factors secretion.

4.
Asian Bioeth Rev ; 15(3): 241-258, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37399006

RESUMO

Evidence suggests a limited contribution to the total research output in leading obstetrics and gynaecology journals by researchers from the developing world. Editorial bias, quality of scientific research produced and language barriers have been attributed as possible causes for this phenomenon. The aim of this study was to understand the prevalence of editorial board members based out of low and lower-middle income countries in leading journals in the field of obstetrics and gynaecology. The top 21 journals in the field of obstetrics and gynaecology were selected based on their impact factor, SCImago ranking and literature search. The composition of the editorial boards of these journals was studied based on World Bank Income Criteria to understand the representation status of researchers from low and lower-middle income countries. A total of 1315 board members make up the editorial composition of leading obstetrics and gynaecology journals. The majority of these editors belong to high-income countries (n = 1148; 87.3%). Low (n = 6; 0.45%) and lower-middle income (n = 55; 4.18%) countries make up for a very minuscule proportion of editorial board members. Only a meagre 9 out of 21 journals have editorial board members from these countries (42.85%). Low and low-middle countries have poor representation in the editorial boards of leading obstetrics and gynaecology journals. Poor representation in research from these countries has grave consequences for a large proportion of the global population and multidisciplinary collaborative efforts must be taken to rapidly change this statistic with immediate effect.

5.
ACS Omega ; 8(20): 17880-17890, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37251171

RESUMO

Photocatalytic degradation of dye contaminants using nanocomposite adsorbents has emerged as a promising solution for wastewater treatment. Owing to its abundant availability, eco-friendly composition, biocompatibility, and strong adsorption activity, spent tea leaf (STL) powder has been extensively explored as a viable dye-adsorbent material. In this work, we report spectacular enhancement in the dye-degradation properties of STL powder on incorporation of ZnIn2S4 (ZIS). The STL/ZIS composite was synthesized using a novel, benign, and scalable aqueous chemical solution method. Comparative degradation and reaction kinetics studies were performed onto an anionic dye, Congo red (CR), and two cationic dyes, Methylene blue (MB) and Crystal violet (CV). The degradation efficiencies of CR, MB, and CV dyes were obtained to be 77.18, 91.29, and 85.36%, respectively, using the STL/ZIS (30%) composite sample after the 120 min experiment. The spectacular improvement in the degradation efficiency of the composite was attributed to its slower charge transfer resistance (as concluded by the EIS study) and optimized surface charge (as concluded by ζ potential study). Scavenger tests and reusability tests deciphered the active species (•O2-) and reusability of the composite samples, respectively. To the best of our knowledge, this is the first report to demonstrate improvement in the degradation efficiency of STL powder on ZIS incorporation.

7.
RSC Adv ; 10(14): 8470-8479, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-35497856

RESUMO

Stalactite is a speleothem which is usually made up of calcium carbonate crystals. In the present study the bacterial isolates, recovered from a stalactite from the Sahastradhara cave, were screened for their ability to precipitate calcium carbonate in order to understand whether mineralization in caves is a biogenic process or not. Five bacterial isolates were found to precipitate calcium carbonate via urease. The most potent bacterial isolate was identified as Klebsiella pneumoniae (accession number MG946801) based on 16S rDNA sequencing. The optimized conditions, for calcium carbonate precipitation, determined by response surface methodology using CCD were found to be: 1.5625% urea, 19.98% inoculum level, 6.98 pH and 38 h 24 min. The morphology and crystalline structure of the precipitated mineral were revealed by SEM. EDX analysis confirmed the presence of carbon, oxygen and calcium in a precipitated crystal. XRD analysis confirmed the crystalline structure of a mineral with rhombohedral shape and 166 Å crystal size. This bacterium can serve as a promising candidate for producing bioconcrete.

8.
Environ Sci Pollut Res Int ; 25(5): 4105-4133, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29238927

RESUMO

Metal-tolerant thermophiles are inhabitants of a wide range of extreme habitats like solfatara fields, hot springs, mud holes, hydrothermal vents oozing out from metal-rich ores, hypersaline pools and soil crusts enriched with metals and other elements. The ability to withstand adverse environmental conditions, like high temperature, high metal concentration and sometimes high pH in their niche, makes them an interesting subject for understanding mechanisms behind their ability to deal with multiple duress simultaneously. Metals are essential for biological systems, as they participate in biochemistries that cannot be achieved only by organic molecules. However, the excess concentration of metals can disrupt natural biogeochemical processes and can impose toxicity. Thermophiles counteract metal toxicity via their unique cell wall, metabolic factors and enzymes that carry out metal-based redox transformations, metal sequestration by metallothioneins and metallochaperones as well as metal efflux. Thermophilic metal resistance is heterogeneous at both genetic and physiology levels and may be chromosomally, plasmid or transposon encoded with one or more genes being involved. These effective response mechanisms either individually or synergistically make proliferation of thermophiles in metal-rich habitats possibly. This article presents the state of the art and future perspectives of responses of thermophiles to metals at genetic as well as physiological levels.


Assuntos
Metais/farmacologia , Microbiologia do Solo , Termotolerância , Microbiologia da Água , Ecossistema , Elétrons , Metais/química , Metais/toxicidade , Solo
9.
World J Microbiol Biotechnol ; 33(6): 112, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28470425

RESUMO

The study of prokaryotic life in high temperature environments viz., geothermal areas, hot, acidic geysers and undersea hydrothermal vents has revealed the existence of thermophiles (or hyperthermophiles). These microorganisms possess various stress adaptation mechanisms which enable them to bypass multiple physical and chemical barriers for survival. The discovery of radiation resistant thermophile Deinococcus geothermalis has given new insights into the field of radiation microbiology. The ability of radiation resistant thermophiles to deal with the lethal effects of ionizing radiations like DNA damage, oxidative bursts and protein damage has made them a model system for exobiology and interplanetary transmission of life. They might be an antiquity of historical transport process that brought microbial life on Earth. These radiation resistant thermophiles are resistant to desiccation as well and maintain their homeostasis by advance DNA repair mechanisms, reactive oxygen species (ROS) detoxification system and accumulation of compatible solutes. Moreover, engineered radioresistant thermophilic strains are the best candidate for bioremediation of radionuclide waste while the extremolytes produced by these organisms may have predicted therapeutic uses. So, the present article delineate a picture of radiation resistance thermophiles, their adaptive mechanisms to evade stress viz., radiation and desiccation, their present applications along with new horizons in near future.


Assuntos
Archaea/fisiologia , Archaea/efeitos da radiação , Bactérias/efeitos da radiação , Fenômenos Fisiológicos Bacterianos/efeitos da radiação , Temperatura Alta , Actinobacteria/fisiologia , Actinobacteria/efeitos da radiação , Bactérias/genética , Fenômenos Fisiológicos Bacterianos/genética , Biodegradação Ambiental , Cianobactérias/fisiologia , Cianobactérias/efeitos da radiação , Dano ao DNA/efeitos da radiação , Reparo do DNA , Deinococcus/genética , Deinococcus/fisiologia , Deinococcus/efeitos da radiação , Microbiologia Ambiental , Exobiologia , Halobacterium/fisiologia , Halobacterium/efeitos da radiação , Pyrococcus/fisiologia , Pyrococcus/efeitos da radiação , Radiação Ionizante , Espécies Reativas de Oxigênio/efeitos da radiação , Explosão Respiratória/efeitos da radiação , Estresse Fisiológico , Sulfolobus/fisiologia , Sulfolobus/efeitos da radiação , Thermococcus/fisiologia , Thermococcus/efeitos da radiação
10.
Arch Microbiol ; 199(3): 391-414, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28097384

RESUMO

Thermo (or hyperthermo) philic microorganisms are ubiquitous having a wide range of habitats from freshly fallen snow to pasteurized milk to geothermal areas like hot springs. The variations in physicochemical conditions, viz., temperature, pH, nutrient availability and light intensity in the habitats always pose stress conditions for the inhabitants leading to slow growth or cell death. The industrial processes used for harvesting secondary metabolites such as enzymes, toxins and organic acids also create stressed environments for thermophiles. The production of DNA-binding proteins, activation of reactive oxygen species detoxification system, compatible solute accumulation, expression of heat shock proteins and alterations in morphology are a few examples of physiological changes demonstrated by these microscopic lifeforms in stress. These microorganisms exhibit complex genetic and physiological changes to minimize, adapt to and repair damage caused by extreme environmental disturbances. These changes are termed as 'stress responses' which enable them to stabilize their homeostasis. The exploration of important thermophilic factors would pave the way in engineering the microbial strains for various biotechnological applications. This review article presents a picture of physiological responses of thermophiles against various stress conditions as their mechanisms to respond to stress make them model organisms to further explore them for basic and applied biology purposes.


Assuntos
Biotecnologia/tendências , Ecossistema , Microbiologia Ambiental , Microbiota/fisiologia , Estresse Fisiológico , Proteínas de Ligação a DNA , Temperatura Alta
11.
Biomed J ; 37(6): 415-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25179695

RESUMO

The impact factor (IF) of an journal is a measure reflecting the average number of citations to recent articles published in the journal. It is frequently used as a proxy for the relative importance of a journal within its field, with journals with higher impact factors deemed to be more important than those with lower ones. However it is not a perfect metric and has its own limitations. Journals are increasingly finding new ways to improve their impact factor by increasing self citation, publishing more review articles. This correspondence discuss the fallacies of the impact factor.


Assuntos
Fator de Impacto de Revistas , Pesquisa Biomédica , Humanos , Editoração
12.
J Res Med Sci ; 19(2): 87-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24778659
13.
Chin J Traumatol ; 15(4): 249-50, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22863346

RESUMO

This case report presents a 25-year-old female patient with anterior dislocation of right shoulder secondary to seizures as a complication of eclampsia. This is an unusual mechanism of injury, but similar to other uncontrolled muscular contractions caused by electroconvulsive therapy, etc. To the best of our knowledge only one such case has been reported in the English literature. Closed reduction under general anaesthesia was successfully achieved. High suspicion in patients complaining of pain over shoulder joint is necessary for early diagnosis of this condition.


Assuntos
Luxação do Ombro , Ombro , Eclampsia , Humanos , Luxações Articulares , Dor
14.
15.
Biotechnol Appl Biochem ; 51(Pt 1): 23-31, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18052929

RESUMO

A Burkholderia cepacia (bacteria) strain, A.T.C.C. 25609, which had been isolated from the bronchial washings of a cystic fibrosis patient, was used to produce lipase. The presence of sodium alginate at an optimal concentration of 8 mg.ml(-1) in the growth medium nearly doubled the production of extracellular lipase activity. The enzyme could be purified with 38-fold purification and 96% activity recovery using a two-step purification protocol. The molecular mass of the purified lipase determined by SDS/PAGE was shown to be 28 kDa. The pH optimum of the purified enzyme was 9 and it was stable up to 12 h at pH 9 and 10. The enzyme has a temperature optimum of 40 degrees C and its half-life (t(1/2)) values were 54 and 46 min at 50 and 60 degrees C respectively. The lipase was found to be stable in the presence of the detergents Tween 20 and Triton X-100. The secondary-structure analysis of lipase by CD spectroscopy showed 52% alpha-helix, 7.7% beta-sheet, 12.6% beta-turn and 27.8% random structure. The lipase was cloned and overexpressed in Escherichia coli. The gene sequence of the cloned lipase was determined and compared with other lipases.


Assuntos
Burkholderia cepacia/enzimologia , Fibrose Cística/enzimologia , Lipase/isolamento & purificação , Lipase/metabolismo , Sequência de Bases , Dicroísmo Circular , Detergentes/química , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Meia-Vida , Humanos , Concentração de Íons de Hidrogênio , Lipase/química , Dados de Sequência Molecular , Peso Molecular , Octoxinol/química , Polissorbatos/química , Estrutura Secundária de Proteína , Temperatura
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