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41.
The rate of food consumption is a major factor affecting success in scramble competition for a limited amount of easy-to-find food. Accordingly, several studies report positive genetic correlations between larval competitive ability and feeding rate in Drosophila; both become enhanced in populations evolving under larval crowding. Here, we report the experimental evolution of enhanced competitive ability in populations of D. melanogaster previously maintained for 84 generations at low density on an extremely poor larval food. In contrast to previous studies, greater competitive ability was not associated with the evolution of higher feeding rate; if anything, the correlation between the two traits across lines tended to be negative. Thus, enhanced competitive ability may be favored by nutritional stress even when competition is not intense, and competitive ability may be decoupled from the rate of food consumption. 相似文献
42.
M. Hemshekhar M. Sebastin Santhosh K. Sunitha R.M. Thushara K. Kemparaju K.S. Rangappa K.S. Girish 《Biochimie》2012
Articular cartilage degeneration and inflammation are the hallmark of progressive arthritis and is the leading cause of disability in 10–15% of middle aged individuals across the world. Cartilage and synovium are mainly degraded by either enzymatic or non-enzymatic ways. Matrix metalloproteinases (MMPs), hyaluronidases (HAases) and aggrecanases are the enzymatic mediators and inflammatory cytokines and reactive oxygen species being non-enzymatic mediators. In addition, MMPs and HAases generated end-products act as inflammation inducers via CD44 and TLR-4 receptors involved NF-κB pathway. Although several drugs have been used to treat arthritis, numerous reports describe the side effects of these drugs that may turn fatal. On this account several medicinal plants and their isolated molecules have been involved in modern medicine strategies to fight against arthritis. In view of this, the present study investigated the antiarthritic potentiality of Crocin, a dietary colorant carotenoid isolated from stigma of Crocus sativus. Crocin effectively neutralized the augmented serum levels of enzymatic (MMP-13, MMP-3 and MMP-9 and HAases) and non-enzymatic (TNF-α, IL-1β, NF-κB, IL-6, COX-2, PGE2 and ROS) inflammatory mediators. Further, Crocin re-established the arthritis altered antioxidant status of the system (GSH, SOD, CAT and GST). It also protected the bone resorption by inhibiting the elevated levels of bone joint exoglycosidases, cathepsin-D and tartrate resistant acid phosphatases. Taken together, Crocin revitalized the arthritis induced cartilage and bone deterioration along with inflammation and oxidative damage that could be accredited to its antioxidant nature. Thus, Crocin could be an effective antiarthritic agent which can equally nullify the arthritis associated secondary complication. 相似文献
43.
Sunitha Rangaraju David Hankins Irina Madorsky Evgenia Madorsky Wei-Hua Lee Christy S. Carter Christiaan Leeuwenburgh Lucia Notterpek 《Aging cell》2009,8(2):178-191
Peripheral nerves from aged animals exhibit features of degeneration, including marked fiber loss, morphological irregularities in myelinated axons and notable reduction in the expression of myelin proteins. To investigate how protein homeostatic mechanisms change with age within the peripheral nervous system, we isolated Schwann cells from the sciatic nerves of young and old rats. The responsiveness of cells from aged nerves to stress stimuli is weakened, which in part may account for the observed age-associated alterations in glial and axonal proteins in vivo . Although calorie restriction is known to slow the aging process in the central nervous system, its influence on peripheral nerves has not been investigated in detail. To determine if dietary restriction is beneficial for peripheral nerve health and glial function, we studied sciatic nerves from rats of four distinct ages (8, 18, 29 and 38 months) kept on an ad libitum (AL) or a 40% calorie restricted diet. Age-associated reduction in the expression of the major myelin proteins and widening of the nodes of Ranvier are attenuated by the dietary intervention, which is paralleled with the maintenance of a differentiated Schwann cell phenotype. The improvements in nerve architecture with diet restriction, in part, are underlined by sustained expression of protein chaperones and markers of the autophagy–lysosomal pathway. Together, the in vitro and in vivo results suggest that there might be an age-limit by which dietary intervention needs to be initiated to elicit a beneficial response on peripheral nerve health. 相似文献
44.
Shankar Bhookya Jalapathi Pochampally Anil Valeru Vianala Sunitha Saikrishna Balabadra Vijjulatha Manga Karunakar rao Kudle 《Journal of chemical biology》2017,10(3):105-115
A series of new tert-butyl 2-(substituted benzamido) phenylcarbamate (4a–4j) were synthesized by the condensation of tert-butyl 2-amino phenylcarbamate (3) with various substituted carboxylic acid in the presence of EDCI and HOBt as coupling reagent, obtain in excellent yields. The structures of all newly synthesized compounds were characterized spectroscopically and evaluated for in vivo anti-inflammatory activity compared to the standard drug, indomethacin, by using the carrageenan-induced rat paw edema protocol. Most of the compounds exhibited a promising anti-inflammatory activity within 9 to 12 h, the percentage of inhibition values ranging from 54.239 to 39.021%. The results revealed that the compounds 4i and 4a exhibited better or equivalent anti-inflammatory activity with the percentage of inhibition of 54.239 and 54.130%, respectively, which was comparable to standard drug. In addition to experimental results, in silico docking studies was used as a tool to verify and expand the experimental outcomes. 相似文献
45.
Gut physiology mediates a trade‐off between adaptation to malnutrition and susceptibility to food‐borne pathogens 下载免费PDF全文
Roshan K. Vijendravarma Sunitha Narasimha Sveta Chakrabarti Aurelie Babin Sylvain Kolly Bruno Lemaitre Tadeusz J. Kawecki 《Ecology letters》2015,18(10):1078-1086
The animal gut plays a central role in tackling two common ecological challenges, nutrient shortage and food‐borne parasites, the former by efficient digestion and nutrient absorption, the latter by acting as an immune organ and a barrier. It remains unknown whether these functions can be independently optimised by evolution, or whether they interfere with each other. We report that Drosophila melanogaster populations adapted during 160 generations of experimental evolution to chronic larval malnutrition became more susceptible to intestinal infection with the opportunistic bacterial pathogen Pseudomonas entomophila. However, they do not show suppressed immune response or higher bacterial loads. Rather, their increased susceptibility to P. entomophila is largely mediated by an elevated predisposition to loss of intestinal barrier integrity upon infection. These results may reflect a trade‐off between the efficiency of nutrient extraction from poor food and the protective function of the gut, in particular its tolerance to pathogen‐induced damage. 相似文献
46.
47.
AbstractObjective: Previous studies have not used family-based methods to evaluate maternal-paternal genetic effects of the folate metabolizing enzyme, dihydro folate reductase (DHFR) essential during embryogenesis. Present study focuses on evaluating the association and influence of parental genetic effects of DHFR 19?bp deletion in the development of foetal neural tube defects (NTDs) using family-based triad approach.Materials and methods: The study population (n?=?924) including 124 NTD case-parent trios (n?=?124?×?3?=?372) and 184 healthy control-parent trios (n?=?184?×?3?=?552) from Telangana, India, was genotyped for DHFR 19?bp deletion. Statistical analysis was used by SPSS and parent-of-origin effects (POE).Results: Foetuses with deletion genotype (DD) were at risk of developing anencephaly (OR =?3.26, p?=?0.020). Among parents, increased maternal risk of having an anencephaly foetus (OR =?2.66, p?=?0.028) was observed in mothers with DD genotype. In addition, POE analysis also demonstrated higher risk of maternal transmission of the deletion allele to anencephaly foetus compared with paternal transmission (OR =?6.00, p?=?0.016). Interestingly, maternal-paternal-offspring genotype incompatibility revealed maternal deletion genotype (DD) in association with paternal heterozygous deletion genotype (WD) significantly increased risk for NTDs (OR =?5.29, p?=?0.013).Conclusions: This study, using family-based case-parent and control-parent triad approach, is the first to report influence of maternal transmission of DHFR 19?bp deletion in the development of anencephaly in the foetus. 相似文献
48.
Statistical experimental design was used to optimize medium constituents and the conditions of fermentation, viz., temperature, pH?and the time of fermentation. Higher yields of L-glutamic acid (37.1?kg/m3) was obtained after optimizing medium components and the conditions of fermentation. The optimal levels of medium components were: 61.5575?kg/m3 glucose, 7.3272?kg/m3 urea and 1.783?μg/dm3 biotin. The optimum productivity was achieved using optimized medium at the fermentation temperature of 33.7?°C, initial pH?7.74, and at the time of fermentation of 58.4?h. 相似文献
49.
Ulett GC Maclean KH Nekkalapu S Cleveland JL Adderson EE 《Journal of immunology (Baltimore, Md. : 1950)》2005,175(4):2555-2562
Apoptosis of murine and human macrophages induced by group B Streptococcus agalactiae (GBS) is likely an important virulence mechanism that is used by the bacteria to suppress the host immune response and to persist at sites of infection. The mechanisms by which GBS induces apoptosis are, however, largely unknown. In this study, we report that in murine macrophages GBS induces unique changes in the regulation and localization of the apoptotic regulators Bad, 14-3-3, and Omi/high-temperature requirement A2 and leads to the release of cytochrome c and the activation of caspase-9 and caspase-3. Furthermore, inhibition of caspase-3 impaired GBS-induced apoptosis of macrophages. The ability to modulate the activity of effector caspases may therefore represent an unexploited avenue for therapeutic intervention in GBS infections. 相似文献
50.
The medium for recombinant phytase production by E. coli BL21 was optimized using response surface methodology. A 23 central composite experimental design was used to study the combined effect of the medium components, tryptone, yeast extract and NaCl. Addition of 2?g/l glucose to the medium greatly influenced the phytase production. The optimization of the medium has increased the phytase production by 1.2 times. The incorporation of 2?g/l glucose significantly enhanced the phytase production by 1.58 times, showing an overall 2.78 fold increase before optimization and other modifications of the medium. The optimized medium with glucose showed a highest phytase activity of 2250?U/l. 相似文献