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181.
Junichi Matsubara Masaya Ono Kazufumi Honda Ayako Negishi Hideki Ueno Takuji Okusaka Junji Furuse Koh Furuta Emiko Sugiyama Yoshiro Saito Nahoko Kaniwa Junichi Sawada Ayako Shoji Tomohiro Sakuma Tsutomu Chiba Nagahiro Saijo Setsuo Hirohashi Tesshi Yamada 《Molecular & cellular proteomics : MCP》2010,9(4):695-704
182.
Hiroki Obata Noritaka Kawashima Masami Akai Kimitaka Nakazawa Tatsuyuki Ohtsuki 《Journal of electromyography and kinesiology》2010,20(1):55-60
The purpose of this study was to characterize the effects of aging on the stretch reflex in the ankle muscles, and in particular to compare the effects on the ankle dorsi-flexor (tibialis anterior: TA) and the plantar-flexor (soleus: SOL). Stretch reflex responses were elicited in the TA and SOL at rest and during weak voluntary contractions in 20 elderly and 23 young volunteers. The results indicated that, in the TA muscle, the elderly group had a remarkably larger long-latency reflex (LLR), whereas no aging effect was found in the short latency reflex (SLR). These results were very different from those in the SOL muscle, which showed significant aging effects in the SLR and medium latency reflex (MLR), but not in the LLR. Given the fact that the LLR of the TA stretch reflex includes the cortical pathway, it is probable that the effects of aging on the TA stretch reflex involve alterations not only at the spinal level but also at the cortical level. The present results indicate that the stretch reflexes of each of the ankle antagonistic muscles are affected differently by aging, which might have relevance to the neural properties of each muscle. 相似文献
183.
Katayama T Tanaka M Moriizumi J Nakamura T Brouchkov A Douglas TA Fukuda M Tomita F Asano K 《Applied and environmental microbiology》2007,73(7):2360-2363
Phylogenetic analysis of bacteria preserved within an ice wedge from the Fox permafrost tunnel was undertaken by cultivation and molecular techniques. The radiocarbon age of the ice wedge was determined. Our results suggest that the bacteria in the ice wedge adapted to the frozen conditions have survived for 25,000 years. 相似文献
184.
We previously demonstrated using a bacterial system that the antigenotoxic activity of the anthraquinone compounds purpurin and alizarin was due to the suppression of microsomal enzyme activity involved in the activation of mutagens. In the present study we determined the effect of purpurin and alizarin on (i) MeIQx-DNA-adduct formation in mouse tissues and (ii) the activity of phases I and II enzymes in liver fractions, the liver being the target tissue of MeIQx. The amount of MeIQx-DNA adduct formed was determined using 32P-postlabeling methods. Methoxyresorufin-O-demethylase (MROD) and ethoxyresorufin-O-deethylase (EROD) enzyme activities, which reflect CYP 1A activity, were measured as markers for phase I enzymes, and UDP-glucuronyltransferase (UGT) and glutathione S-transferase (GST) activities were determined as markers for phase II enzymes. Mice fed with a diet containing 0.5% purpurin for 3 days prior to MeIQx administration had 70% fewer MeIQx-DNA adducts in the lung and kidney, and fewer DNA adducts (insignificant, statistically) in the liver compared with mice fed a diet lacking purpurin. MROD and EROD activities in the liver of these mice increased six- and eight-fold, respectively, and were higher than those determined for the control mice within 1 day following commencement of purpurin treatment. These elevated activities were maintained during treatment and declined immediately following removal of purpurin from the diet. GST and UGT activities gradually increased 2.5- and 3-fold, respectively, following purpurin treatment, and were maintained at significantly high levels even after purpurin administration ceased. Alizarin did not significantly affect DNA-adduct formation and enzyme activity, except in the case of UGT. Taken together, our results show that purpurin reduced MeIQx-DNA-adduct formation by maintaining elevated phase II enzyme activities, thereby facilitating accelerated excretion of MeIQx. 相似文献
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188.
Matsuki Y Ohmura-Hoshino M Goto E Aoki M Mito-Yoshida M Uematsu M Hasegawa T Koseki H Ohara O Nakayama M Toyooka K Matsuoka K Hotta H Yamamoto A Ishido S 《The EMBO journal》2007,26(3):846-854
The presence of post-translational regulation of MHC class II (MHC II) under physiological conditions has been demonstrated recently in dendritic cells (DCs) that potently function as antigen-presenting cells (APCs). Here, we report that MARCH-I, an E3 ubiquitin ligase, plays a pivotal role in the post-translational regulation of MHC II in B cells. MARCH-I expression was particularly high in B cells, and the forced expression of MARCH-I induced the ubiquitination of MHC II. In B cells from MARCH-I-deficient mice (MARCH-I KO), the half-life of surface MHC II was prolonged and the ubiquitinated form of MHC II completely disappeared. In addition, MARCH-I-deficient B cells highly expressed exogenous antigen-loaded MHC II on their surface and showed high ability to present exogenous antigens. These results suggest that the function of MHC II in B cells is regulated through ubiquitination by MARCH-I. 相似文献
189.
He PJ Hirata M Yamauchi N Hashimoto S Hattori MA 《Molecular and cellular biochemistry》2007,302(1-2):111-118
The circadian clock is responsible for the generation of circadian rhythms in hormonal secretion and metabolism. These peripheral
clocks could be reset by various cues in order to adapt to environmental variations. The ovary can be characterized as having
highly dynamic physiology regulated by gonadotropins. Here, we aimed to address the status of circadian clock in the ovary,
and to explore how gonadotropins could regulate clockwork in granulosa cells (GCs). To this end, we mainly utilized the immunohistochemistry,
RT-PCR, and real-time monitoring of gene expression methods. PER1 protein was constantly abundant across the daily cycle in
the GCs of immature ovaries. In contrast, PER1 protein level was obviously cyclic through the circadian cycle in the luteal
cells of pubertal ovaries. In addition, both FSH and LH induced Per1 expression in cultured immature and mature GCs, respectively. The promoter analysis revealed that the Per1 expression was mediated by the cAMP response element binding protein. In cultured transgenic GCs, both FSH and LH also induced
the circadian oscillation of Per2. However, the Per2 oscillation promoted by FSH quickly dampened within only one cycle, whereas the Per2 oscillation promoted by LH was persistently maintained. Collectively, these findings strongly suggest that both FSH and LH
play an important role in regulating circadian clock in the ovary; however, they might exert differential actions on the clockwork
in vivo due to each specific role within ovarian physiology. 相似文献
190.
Murabe M Yamauchi J Fujiwara Y Miyamoto Y Hiroyama M Sanbe A Tanoue A 《Biochemical and biophysical research communications》2007,356(3):739-744
Carbamazepine (CBZ) is one of the most commonly prescribed antiepileptic drugs (AEDs). However, a higher rate of congenital anomalies has been found in infants of mothers treated with CBZ during early pregnancy. Here, we characterize the effects of CBZ using a mouse ES cell differentiation system. The analysis of tissue-specific gene markers showed that CBZ induced early endodermal and mesodermal differentiation but inhibited differentiation of later stages. CBZ also induced ectodermal development, and there was evidence of neural differentiation as ES cells with an immature neuronal phenotype were observed. In contrast, valproic acid (VPA), another anticonvulsant drug, was previously shown to be able to induce ES cells to differentiate into neurons with a mature appearance. CBZ was less cytotoxic to ES cells than VPA. The in vitro ES cell assay system has the potential to provide a rapid and accurate approach for estimating the in vivo embryotoxicity of therapeutic drugs. 相似文献