全文获取类型
收费全文 | 655篇 |
免费 | 79篇 |
国内免费 | 1篇 |
出版年
2022年 | 5篇 |
2021年 | 14篇 |
2020年 | 5篇 |
2019年 | 14篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 22篇 |
2015年 | 22篇 |
2014年 | 29篇 |
2013年 | 32篇 |
2012年 | 33篇 |
2011年 | 30篇 |
2010年 | 24篇 |
2009年 | 24篇 |
2008年 | 35篇 |
2007年 | 29篇 |
2006年 | 31篇 |
2005年 | 29篇 |
2004年 | 30篇 |
2003年 | 19篇 |
2002年 | 20篇 |
2001年 | 19篇 |
2000年 | 15篇 |
1999年 | 28篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 12篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1981年 | 8篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 7篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1965年 | 4篇 |
1964年 | 6篇 |
排序方式: 共有735条查询结果,搜索用时 31 毫秒
91.
Hdmx recruitment into the nucleus by Hdm2 is essential for its ability to regulate p53 stability and transactivation. 总被引:4,自引:0,他引:4
92.
Leptin is produced by adipose tissue and identified as a “satiety signal,” informing the brain when the body has consumed enough food. Specific areas of the hypothalamus express leptin receptors (LEPRs) and are the primary site of leptin action for body weight regulation. In response to leptin, appetite is suppressed and energy expenditure allowed. Beside this hypothalamic action, leptin targets other brain areas in addition to neuroendocrine cells. LEPRs are expressed also in the hippocampus, neocortex, cerebellum, substantia nigra, pancreatic β-cells, and chromaffin cells of the adrenal gland. It is intriguing how leptin is able to activate different ionic conductances, thus affecting excitability, synaptic plasticity and neurotransmitter release, depending on the target cell. Most of the intracellular pathways activated by leptin and directed to ion channels involve PI3K, which in turn phosphorylates different downstream substrates, although parallel pathways involve AMPK and MAPK. In this review we will describe the effects of leptin on BK, KATP, KV, CaV, TRPC, NMDAR and AMPAR channels and clarify the landscape of pathways involved. Given the ability of leptin to influence neuronal excitability and synaptic plasticity by modulating ion channels activity, we also provide a short overview of the growing potentiality of leptin as therapeutic agent for treating neurological disorders. 相似文献
93.
94.
95.
To evaluate the effects of air warming and humidification, we examined the spirometric responses before and after exposure to a conditioned airsteam. Seven healthy subjects, seven clinically stable patients with chronic bronchitis and seven clinically stable asthmatic patients were studied during quiet breathing. All were exposed to the following air conditions for ten minutes: −20°C, dry; 37°C, dry; 37°C, fully saturated; 50°C, dry, and 50°C, fully saturated. As heat increased, airflow progressively improved in asthmatic persons as a group. In contrast, patients with chronic bronchitis, who had more severe underlying airflow obstruction, had most improved airflow with warm dry air inhalation and showed less improvement as humidity was added isothermally. We conclude that active warming of air before inhalation can improve airflow significantly in some patients with reactive obstructed airways, and that high degrees of humidity may exert an independent adverse effect in persons with chronic bronchitis or in those with serious airflow obstruction. 相似文献
96.
A C Alagón H S Guzmán B M Martin A N Ramírez E Carbone L D Possani 《Comparative biochemistry and physiology. B, Comparative biochemistry》1988,89(1):153-161
1. Several toxic polypeptides were found in the venom of the scorpion Centruroides limpidus limpidus. Comparative studies of the potency of the venom in different strains of mice were conducted. 2. A new type of toxin (component II.9), specific for crustaceans (crayfish and isopods), was isolated from this scorpion and was shown to have the following N-terminal amino acid sequence: Lys-Lys-Asp-Gly-Tyr-Leu-Val-Asn-Lys-Tyr-Thr-Gly-Cys-Lys-Val-Asn-Cys- Tyr-Lys-Leu-Gly-Glu-Asn-Lys-Phe-Cys-Asn-Arg-Glu-. 3. A polypeptide toxic to mice (component II.6) from this venom was shown to have the following N-terminal sequence: Lys-Glu-Gly-Tyr-Leu-Val-Asn-His-Ser-Thr-Gly-Cys-Lys-Tyr- Glu-Cys-Tyr-Lys-Leu-Gly-Asp-Asn-Asp-Tyr-Cys-Leu-Arg-Glu-Cys-Lys-. 4. In cultured chick dorsal root ganglion cells, 1 microM of toxin II.6 was shown to reduce the size of sodium currents and to slow-down their activation-inactivation kinetics. The toxin had also a depressive action on the classical Ca2+ current activated at high membrane potentials (greater than 0 mV). 相似文献
97.
Oliver R. Wearn J. Marcus Rowcliffe Chris Carbone Henry Bernard Robert M. Ewers 《PloS one》2013,8(11)
The proliferation of camera-trapping studies has led to a spate of extensions in the known distributions of many wild cat species, not least in Borneo. However, we still do not have a clear picture of the spatial patterns of felid abundance in Southeast Asia, particularly with respect to the large areas of highly-disturbed habitat. An important obstacle to increasing the usefulness of camera trap data is the widespread practice of setting cameras at non-random locations. Non-random deployment interacts with non-random space-use by animals, causing biases in our inferences about relative abundance from detection frequencies alone. This may be a particular problem if surveys do not adequately sample the full range of habitat features present in a study region. Using camera-trapping records and incidental sightings from the Kalabakan Forest Reserve, Sabah, Malaysian Borneo, we aimed to assess the relative abundance of felid species in highly-disturbed forest, as well as investigate felid space-use and the potential for biases resulting from non-random sampling. Although the area has been intensively logged over three decades, it was found to still retain the full complement of Bornean felids, including the bay cat Pardofelis badia, a poorly known Bornean endemic. Camera-trapping using strictly random locations detected four of the five Bornean felid species and revealed inter- and intra-specific differences in space-use. We compare our results with an extensive dataset of >1,200 felid records from previous camera-trapping studies and show that the relative abundance of the bay cat, in particular, may have previously been underestimated due to the use of non-random survey locations. Further surveys for this species using random locations will be crucial in determining its conservation status. We advocate the more wide-spread use of random survey locations in future camera-trapping surveys in order to increase the robustness and generality of inferences that can be made. 相似文献
98.
99.
100.
F. S. van den Brink A. D. Magan P. G. Noordzij C. Zivelonghi P. Agostoni F. D. Eefting J. M. ten Berg M. J. Suttorp B. R. Rensing J. P. van Kuijk P. Klein E. Scholten J. A. S. van der Heyden 《Netherlands heart journal》2018,26(2):76-84