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排序方式: 共有225条查询结果,搜索用时 15 毫秒
91.
S Aravind Kumar s Rajeshkumar SP Saravana Dinesh Ashwin Mathew George Ravindra Kumar Jain 《Bioinformation》2020,16(11):863
The nanoparticles such as hydroxyapatite, zinc oxide, titanium dioxide and zirconium nanoparticles have application in dentistry. Therefore, it is of interest to document the antimicrobial activity of silymarin mediated zinc oxide and hydroxy apatite nanoparticles against oral pathogens. Hence, we synthesized hydroxyapatie and zinc oxide nanoparticles with silymarin and characterized by UV-visible spectrophotometer. Data shows that silymarin mediated HAP and ZnO nanoparticles have antimicrobial activity against oral pathogens such as Pseudomonas sp, Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis and Candida albicans. 相似文献
92.
Marco Brandalise de Andrade Reinaldo J. Bertini Núcleo de Evolução e Paleobiologia de Vertebrados Departamento de Geologia Aplicada Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista Rio Claro SP Brazil 《Historical Biology》2013,25(2):101-136
Oxygen consumption and ammonia excretion rates were assessed for Terebratulina retusa (L.) held under 3 different regimes of temperature and food availability. These were: 5.6?C, no food (cold, starved); 5.8?C, food present (cold, fed) and 10.7?C food present (warm, fed), which simulated winter conditions, summer conditions and an intermediate treatment. Regressions of oxygen consumption on ash‐free dry weight (AFDW) had slopes which were not significantly different from each other and ranged from 0.953 to 0.999. A common slope of 0.976 was calculated and intercepts based on the common slope used to compare oxygen consumption in each treatment. The rise from cold, starved conditions to warm, fed was 24.5 per cent and this was significant (P < 0.05). Other differences were not significant (P > 0.05) but the cold, fed result was 12.6 per cent higher than cold, starved. Therefore feeding and temperature probably account for equivalent proportions of the rise in metabolism from winter to summer. Ammonia production data were much more variable. Excretion rates of a 50 mg AFDW individual (in ng‐at NH3‐N.h‐1) were as follows: cold, starved: 30.2 cold, fed: 7.1; and warm, fed: 22.9. Oxygen to nitrogen (O:N) ratios reflected these results. Mean O:N ratios were: cold, starved: 8.0; cold, fed: 42.4; warm, fed: 16.3. This shows that the simulated winter group relied heavily on protein to fuel their metabolism, the simulated summer group were less dependent on protein and the intermediate group probably used lipids and carbohydrates to fuel metabolic demands. This possibly reflected a trade off between food supply and increased metabolism from treatment to treatment, demonstrating a flexibility which could have been a contributing factor in the ecological tolerance and geological longevity of some brachiopods. 相似文献
93.
Guza R Kotandeniya D Murphy K Dissanayake T Lin C Giambasu GM Lad RR Wojciechowski F Amin S Sturla SJ Hudson RH York DM Jankowiak R Jones R Tretyakova NY 《Nucleic acids research》2011,39(9):3988-4006
Endogenous 5-methylcytosine ((Me)C) residues are found at all CG dinucleotides of the p53 tumor suppressor gene, including the mutational 'hotspots' for smoking induced lung cancer. (Me)C enhances the reactivity of its base paired guanine towards carcinogenic diolepoxide metabolites of polycyclic aromatic hydrocarbons (PAH) present in cigarette smoke. In the present study, the structural basis for these effects was investigated using a series of unnatural nucleoside analogs and a representative PAH diolepoxide, benzo[a]pyrene diolepoxide (BPDE). Synthetic DNA duplexes derived from a frequently mutated region of the p53 gene (5'-CCCGGCACCC GC[(15)N(3),(13)C(1)-G]TCCGCG-3', + strand) were prepared containing [(15)N(3), (13)C(1)]-guanine opposite unsubstituted cytosine, (Me)C, abasic site, or unnatural nucleobase analogs. Following BPDE treatment and hydrolysis of the modified DNA to 2'-deoxynucleosides, N(2)-BPDE-dG adducts formed at the [(15)N(3), (13)C(1)]-labeled guanine and elsewhere in the sequence were quantified by mass spectrometry. We found that C-5 alkylcytosines and related structural analogs specifically enhance the reactivity of the base paired guanine towards BPDE and modify the diastereomeric composition of N(2)-BPDE-dG adducts. Fluorescence and molecular docking studies revealed that 5-alkylcytosines and unnatural nucleobase analogs with extended aromatic systems facilitate the formation of intercalative BPDE-DNA complexes, placing BPDE in a favorable orientation for nucleophilic attack by the N(2) position of guanine. 相似文献
94.
Synaptic and Extrasynaptic NMDA Receptors Are Gated by Different Endogenous Coagonists 总被引:1,自引:0,他引:1
T Papouin L Ladépêche J Ruel S Sacchi M Labasque M Hanini L Groc L Pollegioni JP Mothet SH Oliet 《Cell》2012,150(3):633-646
N-methyl-d-aspartate receptors (NMDARs) are located in neuronal cell membranes at synaptic and extrasynaptic locations, where they are believed to mediate distinct physiological and pathological processes. Activation of NMDARs requires glutamate and a coagonist whose nature and impact on NMDAR physiology remain elusive. We report that synaptic and extrasynaptic NMDARs are gated by different endogenous coagonists, d-serine and glycine, respectively. The regionalized availability of the coagonists matches the preferential affinity of synaptic NMDARs for d-serine and extrasynaptic NMDARs for glycine. Furthermore, glycine and d-serine inhibit NMDAR surface trafficking in?a subunit-dependent manner, which is likely to influence NMDARs subcellular location. Taking advantage of this coagonist segregation, we demonstrate that long-term potentiation and NMDA-induced neurotoxicity rely on synaptic NMDARs only. Conversely, long-term depression requires both synaptic and extrasynaptic receptors. Our observations provide key insights into the operating mode of NMDARs, emphasizing functional distinctions between synaptic and extrasynaptic NMDARs in brain physiology. 相似文献
95.
In Colombia, like most Neotropical countries, faunistic studies on flower flies have been occasional and most of them have been primarily focused on taxonomy. Colombia is the second-most species-rich country in flower fly diversity in the Neotropics after Brazil, and has one of the highest numbers of species per unit area (2.49 per 10,000?km2), based on a review of literature and national collections. Including new data presented here, a total of 47 genera and 300 species are recorded in Colombia. The genera Scaeva Fabricius and Lycastrirhyncha Bigot, as well as 101 species are recorded here for the first time. The altitudinal range and the distribution of the flower fly genera in Colombia are presented. A preliminary comparison of the fauna of Colombia with that of other Neotropical countries is given. A historical perspective is also provided in order to illustrate how Colombian Syrphidae knowledge has progressed over the last 168?years. Information presented here will be useful for ongoing and future biodiversity research as well as conservation projects on Syrphidae in the Neotropical region. 相似文献
96.
Dr. Lad Čelakovský 《Plant Systematics and Evolution》1872,22(11):349-352
97.
R E Armer J S Barlow N Chopra C J Dutton D H Greenway S D Greenwood N Lad J Shaw A P Thompson K W Thong I Tommasini 《Bioorganic & medicinal chemistry letters》1999,9(16):2425-2430
Analogues of the antimalarial pentaquine, 1, in which the nature of the side-chain on the 8-amino position was varied, were prepared and evaluated for anticoccidial activity both in vitro and in vivo. Specifically, both the inter-nitrogen distance and the nature of the terminal amino group were investigated. Novel analogues of equal or improved efficacy in vitro and in vivo to pentaquine were discovered. 相似文献
98.
D. Balachandar P. Raja K. Nirmala T. R. Rithyl SP. Sundaram 《World journal of microbiology & biotechnology》2008,24(10):2087-2095
Pink-pigmented facultative methylotrophs (PPFMs) are one of the beneficial proteobacteria commonly found in phyllosphere,
rhizosphere and as endophytes in cotton. To assess the impact of transgenic Bt-cotton on changes in the diversity and community
profile of PPFMs by comparing with its non-transgenic cotton, a polyphasic approach including differential carbon-substrate
utilization profiling and DNA fingerprinting techniques like ARDRA, RISA, BOX-PCR and ERIC-PCR were studied. PPFMs from phyllosphere,
rhizoplane and internal tissues of the stem of both Bt-cotton and non-Bt-cotton were isolated and analysed in this study.
All the results suggested that the diversity richness of PPFMs present in the phyllosphere, rhizoplane and internal tissues
did not differ between Bt- and non-Bt-cotton. In this study, there was no evidence to indicate any adverse effects of Bt-cotton
on the diversity of plant-associated methylobacteria. 相似文献
99.
Background
The tolerability and efficacy of single dose albendazole (400 mg), diethylcarbamazine citrate (DEC) (6 mg/kg bodyweight) or co-administration of albendazole (400 mg) + DEC (6 mg/kg bodyweight) was studied in 54 asymptomatic Wuchereria bancrofti microfilaraemic volunteers in a double blind hospital-based clinical study. 相似文献100.