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排序方式: 共有318条查询结果,搜索用时 203 毫秒
1.
S. Raj V. Vinod J. Jayakumar P. Suresh A. Kumar R. Biswas 《Letters in applied microbiology》2021,73(1):31-38
Candida species are opportunistic human fungal pathogens that cause acute and chronic infections against which only few antifungal agents are available. Here we have elucidated the antifungal effect of Syzygium samarangense leaf extracts (SSLE). Antifungal activity of SSLE was studied against Candida albicans, C. krusei, C. parapsilosis, C. glabrata, C. auris and C. tropicalis. Following experiments were performed: minimum fungicidal concentration (MFC) determination, agar well disc diffusion assays, fungal morphology analysis using scanning electron microscope (SEM), ex vivo fungal survival assays on porcine tongue and skin and in vivo fungal survival assays using Drosophila melanogaster fly model. Results demonstrated MFC of SSLE ranges between 100 and 125 mg ml−1. SEM images showed cell wall degradation of C. albicans when treated with SSLE. Around 75% decrease in C. albicans viability was observed when infected porcine tongue and skin were treated using SSLE. The C. albicans infected D. melanogaster when fed with SSLE showed significant decrease (around 80%) of fungal count than the infected control. Furthermore, agar plate disc diffusion assays demonstrated that the antifungal activity of SSLE could be due to chalcone, which is one of the active constituents in SSLE. Our study demonstrated that SSLE could be used for the topical treatment of Candida infections. 相似文献
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Chana Borjigin Rhiannon K. Schilling Jayakumar Bose Maria Hrmova Jiaen Qiu Stefanie Wege Apriadi Situmorang Caitlin Byrt Chris Brien Bettina Berger Matthew Gilliham Allison S. Pearson Stuart J. Roy 《Plant, cell & environment》2020,43(9):2158-2171
Improving salinity tolerance in the most widely cultivated cereal, bread wheat (Triticum aestivum L.), is essential to increase grain yields on saline agricultural lands. A Portuguese landrace, Mocho de Espiga Branca accumulates up to sixfold greater leaf and sheath sodium (Na+) than two Australian cultivars, Gladius and Scout, under salt stress in hydroponics. Despite high leaf and sheath Na+ concentrations, Mocho de Espiga Branca maintained similar salinity tolerance compared to Gladius and Scout. A naturally occurring single nucleotide substitution was identified in the gene encoding a major Na+ transporter TaHKT1;5-D in Mocho de Espiga Branca, which resulted in a L190P amino acid residue variation. This variant prevents Mocho de Espiga Branca from retrieving Na+ from the root xylem leading to a high shoot Na+ concentration. The identification of the tissue-tolerant Mocho de Espiga Branca will accelerate the development of more elite salt-tolerant bread wheat cultivars. 相似文献
6.
Denitrification in the ocean is a major sink for fixed nitrogen in the global N budget, but the process is geographically
restricted to a few oceanic regions, including three oceanic oxygen minimum zones (OMZ) and hemipelagic sediments worldwide.
Here, we describe the diversity and community composition of microbes responsible for denitrification in the OMZ using polymerase
chain reaction, sequence and fragment analysis of clone libraries of the signature genes (nirK and nirS) that encode the enzyme nitrite reductase, responsible for key denitrification transformation steps. We show that denitrifying
assemblages vary in space and time and exhibit striking changes in diversity associated with the progression of denitrification
from initial anoxia through nitrate depletion. The initial denitrifying assemblage is highly diverse, but succession on the
scale of 3–12 days leads to a much less diverse assemblage and dominance by one or a few phylotypes. This progression occurs
in the natural environment as well as in enclosed incubations. The emergence of dominants from a vast reservoir of rare types
has implications for the maintenance of diversity of the microbial population and suggests that a small number of microbial
dominants may be responsible for the greatest rates of transformations involving nitrous oxide and global fixed nitrogen loss.
Denitrifying blooms, driven by a few types responding to episodic environmental changes and distributed unevenly in time and
space, are consistent with the sampling effect model of diversity–function relationships. Canonical denitrification thus appears
to have important parallels with both primary production and nitrogen fixation, which are typically dominated by regionally
and temporally restricted blooms that account for a disproportionate share of these processes worldwide. 相似文献
7.
K. Madhumathi K.T. Shalumon V.V. Divya Rani H. Tamura T. Furuike N. Selvamurugan S.V. Nair R. Jayakumar 《International journal of biological macromolecules》2009,45(1):12-15
Chitosan, a deacetylated derivative of chitin is a commonly studied biomaterial for tissue-engineering applications due to its biocompatibility, biodegradability, low toxicity, antibacterial activity, wound healing ability and haemostatic properties. However, chitosan has poor mechanical strength due to which its applications in orthopedics are limited. Hydroxyapatite (HAp) is a natural inorganic component of bone and teeth and has mechanical strength and osteoconductive property. In this work, HAp was deposited on the surface of chitosan hydrogel membranes by a wet chemical synthesis method by alternatively soaking the membranes in CaCl2 (pH 7.4) and Na2HPO4 solutions for different time intervals. These chitosan hydrogel–HAp membranes were characterized using SEM, AFM, EDS, FT-IR and XRD analyses. MTT assay was done to evaluate the biocompatibility of these membranes using MG-63 osteosarcoma cells. The biocompatibility studies suggest that chitosan hydrogel–HAp composite membranes can be useful for tissue-engineering applications. 相似文献
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Peter I. Dosa Sonja Strah-Pleynet Honnappa Jayakumar Martin Casper Marc Decaire Yifeng Xiong Juerg Lehmann Karoline Choi Katie Elwell Amy Wong Robert R. Webb John W. Adams Juan Ramirez Jeremy G. Richman William Thomsen Graeme Semple Bradley R. Teegarden 《Bioorganic & medicinal chemistry letters》2009,19(18):5486-5489
Potent 5-HT2A inverse-agonists containing phenyl-pyrazole ureas with an amino side chain were identified. Optimization of this series resulted in selective compounds that proved effective in modulating 5HT-induced amplification of ADP-stimulated human platelet aggregation. 相似文献
9.
Kekeli Ekoue-Kovi Kimberly Yearick Daniel P. Iwaniuk Jayakumar K. Natarajan John Alumasa Angel C. de Dios Paul D. Roepe Christian Wolf 《Bioorganic & medicinal chemistry》2009,17(1):270-283
We report the synthesis and in vitro antimalarial activities of more than 50 7-chloro-4-aminoquinolyl-derived sulfonamides 3–8 and 11–26, ureas 19–22, thioureas 23–26, and amides 27–54. Many of the CQ analogues prepared for this study showed submicromolar antimalarial activity versus HB3 (chloroquine sensitive) and Dd2 (chloroquine resistant strains of Plasmodium falciparum) and low resistance indices were obtained in most cases. Systematic variation of the side chain length and introduction of fluorinated aliphatic and aromatic termini revealed promising leads that overcome CQ resistance. In particular, sulfonamide 3 exhibiting a short side chain with a terminal dansyl moiety combined high antiplasmodial potency with a low resistance index and showed IC50s of 17.5 and 22.7 nM against HB3 and Dd2 parasites. 相似文献
10.
Palanisamy Jayakumar Esaki Muthu Shankar Murugesan Karthikeyan 《Bioscience Hypotheses》2009,2(5):282-285
Immune reconstitution inflammatory syndrome (IRIS) is an inflammatory manifestation that occurs subsequent to initiation of highly active antiretroviral therapy in terminal (HAART) HIV infection, mainly due to the restoration of robust immune responses directed against latent microbial antigens. IRIS is believed to be multifactorial and less studied. Herein, we postulate that hypothalamo-pituitary-adrenal (HPA) dysregulation, a well-documented manifestation in HIV/AIDS, could possibly disturb the balance between pro-inflammatory and anti-inflammatory cytokines leading to clinical IRIS. Drugs, opportunistic infections, stress and numerous intrinsic and extrinsic factors have been described to be the possible causes of IRIS in HIV illness. 相似文献