全文获取类型
收费全文 | 1266篇 |
免费 | 106篇 |
国内免费 | 1篇 |
专业分类
1373篇 |
出版年
2023年 | 7篇 |
2022年 | 24篇 |
2021年 | 35篇 |
2020年 | 16篇 |
2019年 | 22篇 |
2018年 | 26篇 |
2017年 | 24篇 |
2016年 | 29篇 |
2015年 | 44篇 |
2014年 | 51篇 |
2013年 | 67篇 |
2012年 | 92篇 |
2011年 | 94篇 |
2010年 | 43篇 |
2009年 | 42篇 |
2008年 | 69篇 |
2007年 | 69篇 |
2006年 | 57篇 |
2005年 | 55篇 |
2004年 | 55篇 |
2003年 | 56篇 |
2002年 | 35篇 |
2001年 | 27篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 15篇 |
1995年 | 15篇 |
1994年 | 14篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 22篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1971年 | 6篇 |
1970年 | 11篇 |
1969年 | 7篇 |
1968年 | 10篇 |
排序方式: 共有1373条查询结果,搜索用时 0 毫秒
31.
Adipocyte/macrophage fatty acid binding proteins control integrated metabolic responses in obesity and diabetes 总被引:8,自引:0,他引:8
Maeda K Cao H Kono K Gorgun CZ Furuhashi M Uysal KT Cao Q Atsumi G Malone H Krishnan B Minokoshi Y Kahn BB Parker RA Hotamisligil GS 《Cell metabolism》2005,1(2):107-119
Fatty acid binding proteins (FABPs) are cytosolic fatty acid chaperones whose biological role and mechanisms of action are not well understood. Here, we developed mice with targeted mutations in two related adipocyte FABPs, aP2 and mal1, to resolve their role in systemic lipid, glucose, and energy metabolism. Mice lacking aP2 and mal1 exhibited a striking phenotype with strong protection from diet-induced obesity, insulin resistance, type 2 diabetes, and fatty liver disease. These mice have altered cellular and systemic lipid transport and composition, leading to enhanced insulin receptor signaling, enhanced muscle AMP-activated kinase (AMP-K) activity, and dramatically reduced liver stearoyl-CoA desaturase-1 (SCD-1) activity underlying their phenotype. Taken together with the previously reported strong protection against atherosclerosis, these results demonstrate that adipocyte/macrophage FABPs have a robust impact on multiple components of metabolic syndrome, integrating metabolic and inflammatory responses in mice and constituting a powerful target for the treatment of these diseases. 相似文献
32.
Agency,intimacy, and rape jokes: an ethnographic study of young women and sexual risk in Chennai 下载免费PDF全文
Sneha Krishnan 《The journal of the Royal Anthropological Institute》2016,22(1):67-83
In this article, I examine the circulation of jokes about sexual violence among young middle‐class women in the South Indian city of Chennai. Drawing on ethnographic research with undergraduate students in this city, I locate the rape joke in an ambivalent discourse of risk that conflates the possibility of sexual assault with the perceived ‘risks’ of women's sexual autonomy. In this context, I argue that humour about sexual violence functions as a form of lateral agency, facilitating a break from the task of reproducing middle‐class respectability. 相似文献
33.
Background and Purpose
Most information on the dose-response of radiation-induced cancer is derived from data on the A-bomb survivors. Since, for radiation protection purposes, the dose span of main interest is between zero and one Gy, the analysis of the A-bomb survivors is usually focused on this range. However, estimates of cancer risk for doses larger than one Gy are becoming more important for radiotherapy patients. Therefore in this work, emphasis is placed on doses relevant for radiotherapy with respect to radiation induced solid cancer.Materials and methods
For various organs and tissues the analysis of cancer induction was extended by an attempted combination of the linear-no-threshold model from the A-bomb survivors in the low dose range and the cancer risk data of patients receiving radiotherapy for Hodgkin's disease in the high dose range. The data were fitted using organ equivalent dose (OED) calculated for a group of different dose-response models including a linear model, a model including fractionation, a bell-shaped model and a plateau-dose-response relationship.Results
The quality of the applied fits shows that the linear model fits best colon, cervix and skin. All other organs are best fitted by the model including fractionation indicating that the repopulation/repair ability of tissue is neither 0 nor 100% but somewhere in between. Bone and soft tissue sarcoma were fitted well by all the models. In the low dose range beyond 1 Gy sarcoma risk is negligible. For increasing dose, sarcoma risk increases rapidly and reaches a plateau at around 30 Gy.Conclusions
In this work OED for various organs was calculated for a linear, a bell-shaped, a plateau and a mixture between a bell-shaped and plateau dose-response relationship for typical treatment plans of Hodgkin's disease patients. The model parameters (α and R) were obtained by a fit of the dose-response relationships to these OED data and to the A-bomb survivors. For any three-dimensional inhomogenous dose distribution, cancer risk can be compared by computing OED using the coefficients obtained in this work. 相似文献34.
Infection by Cuscuta and Orobanche causes significant losses in dry solids and protein content in host plant or plant part. Changes occur in phosphatase activity towards fructose-1,6-diphosphate at alkaline pH and β-glycerophosphate at acid pH, expressed per mg protein or g fresh tissue. The leaves of all hosts infected by Orobanche show an increase in the alkaline fructosediphosphatase activity, whereas as far as the infection by Cuscuta is concerned the general response is a decrease in the enzyme in the shoots. The alterations in the phosphatase activity towards β-glycerophosphate at acid pH in the shoots are not consistent. However, there is a marked increase in the acid phosphatase activity against β-glycerophosphatase in the roots of the infected hosts. The significance of these findings has been discussed in the light of host-parasite interrelationship. 相似文献
35.
36.
R Ciulla C Clougherty N Belay S Krishnan C Zhou D Byrd M F Roberts 《Journal of bacteriology》1994,176(11):3177-3187
Methanobacterium thermoautotrophicum delta H and Marburg were adapted to grow in medium containing up to 0.65 M NaCl. From 0.01 to 0.5 M NaCl, there was a lag before cell growth which increased with increasing external NaCl. The effect of NaCl on methane production was not significant once the cells began to grow. Intracellular solutes were monitored by nuclear magnetic resonance (NMR) spectroscopy as a function of osmotic stress. In the delta H strain, the major intracellular small organic solutes, cyclic-2,3-diphosphoglycerate and glutamate, increased at most twofold between 0.01 and 0.4 M NaCl and decreased when the external NaCl was 0.5 M. M. thermoautotrophicum Marburg similarly showed a decrease in solute (cyclic-2,3-diphosphoglycerate, 1,3,4,6-tetracarboxyhexane, and L-alpha-glutamate) concentrations for cells grown in medium containing > 0.5 M NaCl. At 0.65 M NaCl, a new organic solute, which was visible in only trace amounts at the lower NaCl concentrations, became the dominant solute. Intracellular potassium in the delta H strain, detected by atomic absorption and 39K NMR, was roughly constant between 0.01 and 0.4 M and then decreased as the external NaCl increased further. The high intracellular K+ was balanced by the negative charges of the organic osmolytes. At the higher external salt concentrations, it is suggested that Na+ and possibly Cl- ions are internalized to provide osmotic balance. A striking difference of strain Marburg from strain delta H was that yeast extract facilitated growth in high-NaCl-containing medium. The yeast extract supplied only trace NMR-detectable solutes (e.g., betaine) but had a large effect on endogenous glutamate levels, which were significantly decreased. Exogenous choline and glycine, instead of yeast extract, also aided growth in NaCl-containing media. Both solutes were internalized with the choline converted to betaine; the contribution to osmotic balance of these species was 20 to 25% of the total small-molecule pool. These results indicate that M. thermoautotrophicum shows little changes in its internal solutes over a wide range of external NaCl. Furthermore, they illustrate the considerable differences in physiology in the delta H and Marburg strains of this organism. 相似文献
37.
A rapid propagation method comprising initiation of in vitro shoot tip culture from field-grown flowering plants and reculture of the nodal segments of regenerated shoots in Schenk and Hildebrandt (1972) medium was developed for Woodfordia fruticosa (L.) Kurz., a rare medicinal shrub. A medium supplement of 6-benzylaminopurine (0.2 mg.l–1) induced high frequency (88%) development of axillary shoot buds (3.2) in 4–5 weeks. Subculture of the explants with multiple new shoots in fresh medium for 30 days yielded an even larger number (9.7) of shoots. Highest multiplication (26–35 shoots) was recorded when using culture initiation media with 0.5 mg.l–1 each of BAP and NAA followed by subculture in 0.2 mg.l–1 BAP. The shoot multiplication rate was further accelerated by reculturing 0.4–0.6 cm nodal segments of regenerated shoots in media with 1.0 mg.l–1 BAP. Shoot cuttings (3.5–7.0 cm) were rooted in 0.2 mg.l–1 IAA. Regenerated plants displayed uniform morphological, growth and flowering characteristics.Abbreviations BAP
6-benzylaminopurine
- NAA
naphthaleneacetic acid
- IAA
Indole-3-acetic acid
- IBA
indole-3-butyric acid
- SH
Schenk and Hildebrandt (1972) medium 相似文献
38.
Binnur Eroglu Donald E. Kimbler Junfeng Pang Justin Choi Demetrius Moskophidis Nathan Yanasak Krishnan M. Dhandapani Nahid F. Mivechi 《Journal of neurochemistry》2014,130(5):626-641
Traumatic brain injury (TBI) induces severe harm and disability in many accident victims and combat‐related activities. The heat‐shock proteins Hsp70/Hsp110 protect cells against death and ischemic damage. In this study, we used mice deficient in Hsp110 or Hsp70 to examine their potential requirement following TBI. Data indicate that loss of Hsp110 or Hsp70 increases brain injury and death of neurons. One of the mechanisms underlying the increased cell death observed in the absence of Hsp110 and Hsp70 following TBI is the increased expression of reactive oxygen species‐induced p53 target genes Pig1, Pig8, and Pig12. To examine whether drugs that increase the levels of Hsp70/Hsp110 can protect cells against TBI, we subjected mice to TBI and administered Celastrol or BGP‐15. In contrast to Hsp110‐ or Hsp70i‐deficient mice that were not protected following TBI and Celastrol treatment, there was a significant improvement of wild‐type mice following administration of these drugs during the first week following TBI. In addition, assessment of neurological injury shows significant improvement in contextual and cued fear conditioning tests and beam balance in wild‐type mice that were treated with Celastrol or BGP‐15 following TBI compared to TBI‐treated mice. These studies indicate a significant role of Hsp70/Hsp110 in neuronal survival following TBI and the beneficial effects of Hsp70/Hsp110 inducers toward reducing the pathological consequences of TBI.
39.