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991.
Store-operated Ca2+ entry (SOCE) from the extracellular space plays a critical role in agonist-mediated Ca2+ signaling in non-excitable cells. Here we show that SOCE is enhanced in COS-7 cells treated with staurosporine (ST), a protein kinase inhibitor. In COS-7 cells, stimulation with ATP induced Ca2+ release from intracellular Ca2+ stores and Ca2+ entry from the extracellular space. Ca2+ release was not affected by treatment with ST, but Ca2+ entry continued in the ST-treated cells even after the removal of ATP. ST did not inhibit Ca2+ sequestration into Ca2+ stores. The Ca2+ entry induced by cyclopiazonic acid (CPA), a reversible ER Ca2+ pump inhibitor, was maintained in ST-treated cells even after the removal of CPA, but was not maintained in the control cells. The sustained Ca2+ entry in ST-treated cells was completely attenuated by the SOCE inhibitors, La3+ and 2-APB. The large increase in Ca2+ entry produced in the cells co-expressing Venus-Orai1 and STIM1-mKO1 was stabilized with ST treatment, and confocal imaging of these cells suggested that the complex between Orai1 and STIM1 did not completely dissociate following the refilling of Ca2+ stores. These results show that SOCE remains activated even after the refilling of Ca2+ stores in ST-treated cells and that the effect of ST on SOCE may result from a stabilization of the Orai1–STIM1 interaction. 相似文献
992.
Tomoyo Okumura Chizuru Takashima Fumito Shiraishi Shin Nishida Akihiro Kano 《Geomicrobiology journal》2013,30(10):910-927
A daily rhythm of microbial processes, in terms of sub-mm order lamination, was identified for a microbe-rich aragonite travertine formed at a low-flow site of the Nagano-yu Hot Spring in Southwestern Japan. Continuous observation and sampling clearly showed that the lamination consisted of diurnal microbe-rich layers (M-layers) and nocturnal crystalline layers (C-layers). The M-layers originated from biofilm formed by growth and upward migration of filamentous cyanobacteria related to Microcoleus sp., which can rapidly glide and secrete extracellular polymeric substances (EPS). During the daytime, cyanobacterial biofilm development inhibited aragonite precipitation on the travertine surface due to the calcium-binding ability of EPS. After sunset, aragonite precipitation started on the surface where aerobic heterotrophic bacteria decomposed EPS, which induced precipitation of micritic crystals. This early stage of C-layer formation was followed by abiotic precipitation of fan-shaped aragonite aggregates. Despite their major role in lamina formation, the cyanobacteria were readily degraded within 6–10 days after embedding, and the remaining open spaces in the M-layers were sparsely filled with crystal clots. These lamina-forming processes were different from those observed in a high-flow site where the travertine has a dense texture of aragonite crystals. The microbial travertine at Nagano-yu is similar to some Precambrian stromatolites in terms of in situ mineral precipitation, regular sub-mm order lamination, and arrangement of filamentous microbes; therefore, the lamination of these stromatolites possibly occur with a daily rhythm. The microbial processes demonstrated in this study may revise the interpretation of ancient stromatolite formation. 相似文献
993.
Takuya Kitamoto Aya Kitamoto Masato Yoneda Hideyuki Hyogo Hidenori Ochi Takahiro Nakamura Hajime Teranishi Seiho Mizusawa Takato Ueno Kazuaki Chayama Atsushi Nakajima Kazuwa Nakao Akihiro Sekine Kikuko Hotta 《Human genetics》2013,132(7):783-792
We examined the genetic background of nonalcoholic fatty liver disease (NAFLD) in the Japanese population, by performing a genome-wide association study (GWAS). For GWAS, 392 Japanese NAFLD subjects and 934 control individuals were analyzed. For replication studies, 172 NAFLD and 1,012 control subjects were monitored. After quality control, 261,540 single-nucleotide polymorphisms (SNPs) in autosomal chromosomes were analyzed using a trend test. Association analysis was also performed using multiple logistic regression analysis using genotypes, age, gender and body mass index (BMI) as independent variables. Multiple linear regression analyses were performed to evaluate allelic effect of significant SNPs on biochemical traits and histological parameters adjusted by age, gender, and BMI. Rs738409 in the PNPLA3 gene was most strongly associated with NAFLD after adjustment (P = 6.8 × 10?14, OR = 2.05). Rs2896019, and rs381062 in the PNPLA3 gene, rs738491, rs3761472, and rs2143571 in the SAMM50 gene, rs6006473, rs5764455, and rs6006611 in the PARVB gene had also significant P values (<2.0 × 10?10) and high odds ratios (1.84–2.02). These SNPs were found to be in the same linkage disequilibrium block and were associated with decreased serum triglycerides and increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in NAFLD patients. These SNPs were associated with steatosis grade and NAFLD activity score (NAS). Rs738409, rs2896019, rs738491, rs6006473, rs5764455, and rs6006611 were associated with fibrosis. Polymorphisms in the SAMM50 and PARVB genes in addition to those in the PNPLA3 gene were observed to be associated with the development and progression of NAFLD. 相似文献
994.
Yoshitada Tanabe Fumihito Tajima Yuki Nakamura Eriko Shibasaki Mai Wakejima Takashi Shimomura Rie Murai Yoshiyuki Murawaki Koichi Hashiguchi Takamasa Kanbe Toshiya Saeki Miho Ichiba Yoko Yoshida Masahiro Mitsunari Soichi Yoshida Jun-ichiro Miake Yasutaka Yamamoto Naoki Nagata Tasuku Harada Akihiro Kurimasa Ichiro Hisatome Naoki Terakawa Yoshikazu Murawaki Goshi Shiota 《Biochemical and biophysical research communications》2011,(4):769
995.
Oe K Ueha T Sakai Y Niikura T Lee SY Koh A Hasegawa T Tanaka M Miwa M Kurosaka M 《Biochemical and biophysical research communications》2011,(1):148-152
Quasispecies is a remarkable characteristic of hepatitis C virus (HCV) and has profound roles in HCV biology and clinical practice. The understanding of HCV quasispecies behavior, in particular in acute HCV infection, is valuable for vaccine development and therapeutic interference. However, acute HCV infection is seldom encountered in clinic practice due to its silent onset. In the present study, we reported a unique case of de novo HCV infection associated with the transplantation of bone marrow from a HCV-positive donor. HCV quasispecies diversity was determined in both the donor and the recipient over a 4-year follow-up, accompanied with simultaneous measurement of HCV neutralizing antibody. Detailed genetic and phylogenetic analyses revealed a divergent quasispecies evolution, which was not related to dynamic changes of HCV neutralizing antibody. Instead, our data suggested an essential role of the fitness adaptation of founder viral population in driving such an evolutionary pattern. 相似文献
996.
Takahiko Hamaguchi Hiroki Wakabayashi Akihiko Matsumine Akihiro Sudo Atsumasa Uchida 《Biochemical and biophysical research communications》2011,(3):2104
In the evolution of cancer, tumor necrosis factor-alpha (TNF-α) plays a paradoxical role. High doses induce significant anticancer effects, but conversely, physiologic and pathologic levels of TNF-α may be involved in cancer promotion, tumor growth, and metastasis.Infliximab is a chimeric murine monoclonal antibody that binds with high affinity to soluble and membrane TNF-α and inhibits binding of TNF-α to its receptors. In the present study, we investigated the effect of infliximab, a TNF-α antagonist, on breast cancer aggressiveness and bone metastases.Infliximab greatly reduced cell motility and bone metastases in a metastatic breast cancer cell line, MDA-MB-231. The mechanism of bone metastasis inhibition involved decreased expression of CXC chemokine receptor 4 (CXCR4) and increased expression of decorin, which is the prototype of an expanding family of small leucine-rich proteoglycans. These results suggest a novel role for TNF-α inhibition in the reduction or prevention of bone metastases in this breast cancer model. Our study suggests that inhibition of TNF-α using infliximab may become a preventive therapeutic option for breast cancer. 相似文献
997.
Keisuke Oe Takeshi Ueha Yoshitada Sakai Takahiro Niikura Sang Yang Lee Akihiro Koh Takumi Hasegawa Masaya Tanaka Masahiko Miwa Masahiro Kurosaka 《Biochemical and biophysical research communications》2011,407(1):148
In Europe, carbon dioxide therapy has been used for cardiac disease and skin problems for a long time. However there have been few reports investigating the effects of carbon dioxide therapy on skeletal muscle. Peroxisome proliferators-activated receptor (PPAR)-gamma coactivator-1 (PGC-1α) is up-regulated as a result of exercise and mediates known responses to exercise, such as mitochondrial biogenesis and muscle fiber-type switching, and neovascularization via up-regulation of vascular endothelial growth factor (VEGF). It is also known that silent mating type information regulation 2 homologs 1 (SIRT1) enhances PGC-1α-mediated muscle fiber-type switching. Previously, we demonstrated transcutaneous application of CO2 increased blood flow and a partial increase of O2 pressure in the local tissue known as the Bohr effect. In this study, we transcutaneously applied CO2 to the lower limbs of rats, and investigated the effect on the fast muscle, tibialis anterior (TA) muscle. The transcutaneous CO2 application caused: (1) the gene expression of PGC-1α, silent mating type information regulation 2 homologs 1 (SIRT1) and VEGF, and increased the number of mitochondria, as proven by real-time PCR and immunohistochemistry, (2) muscle fiber switching in the TA muscle, as proven by isolation of myosin heavy chain and ATPase staining. Our results suggest the transcutaneous application of CO2 may have therapeutic potential for muscular strength recovery resulting from disuse atrophy in post-operative patients and the elderly population. 相似文献
998.
999.
Akihiro Kusumi Takahiro K. Fujiwara Taka A. Tsunoyama Rinshi S. Kasai An‐An Liu Koichiro M. Hirosawa Masanao Kinoshita Nobuaki Matsumori Naoko Komura Hiromune Ando Kenichi G. N. Suzuki 《Traffic (Copenhagen, Denmark)》2020,21(1):106-137
Many plasma membrane (PM) functions depend on the cholesterol concentration in the PM in strikingly nonlinear, cooperative ways: fully functional in the presence of physiological cholesterol levels (35~45 mol%), and nonfunctional below 25 mol% cholesterol; namely, still in the presence of high concentrations of cholesterol. This suggests the involvement of cholesterol‐based complexes/domains formed cooperatively. In this review, by examining the results obtained by using fluorescent lipid analogs and avoiding the trap of circular logic, often found in the raft literature, we point out the fundamental similarities of liquid‐ordered (Lo)‐phase domains in giant unilamellar vesicles, Lo‐phase‐like domains formed at lower temperatures in giant PM vesicles, and detergent‐resistant membranes: these domains are formed by cooperative interactions of cholesterol, saturated acyl chains, and unsaturated acyl chains, in the presence of >25 mol% cholesterol. The literature contains evidence, indicating that the domains formed by the same basic cooperative molecular interactions exist and play essential roles in signal transduction in the PM. Therefore, as a working definition, we propose that raft domains in the PM are liquid‐like molecular complexes/domains formed by cooperative interactions of cholesterol with saturated acyl chains as well as unsaturated acyl chains, due to saturated acyl chains' weak multiple accommodating interactions with cholesterol and cholesterol's low miscibility with unsaturated acyl chains and TM proteins. Molecules move within raft domains and exchange with those in the bulk PM. We provide a logically established collection of fluorescent lipid probes that preferentially partition into raft and non‐raft domains, as defined here, in the PM. 相似文献
1000.
Akira Yoshimi Motoaki Sano Azusa Inaba Yuko Kokubun Tomonori Fujioka Osamu Mizutani Daisuke Hagiwara Takashi Fujikawa Marie Nishimura Shigekazu Yano Shin Kasahara Kiminori Shimizu Masashi Yamaguchi Kazuyoshi Kawakami Keietsu Abe 《PloS one》2013,8(1)
Although α-1,3-glucan is one of the major cell wall polysaccharides in filamentous fungi, the physiological roles of α-1,3-glucan remain unclear. The model fungus Aspergillus nidulans possesses two α-1,3-glucan synthase (AGS) genes, agsA and agsB. For functional analysis of these genes, we constructed several mutant strains in A. nidulans: agsA disruption, agsB disruption, and double-disruption strains. We also constructed several CagsB strains in which agsB expression was controlled by the inducible alcA promoter, with or without the agsA-disrupting mutation. The agsA disruption strains did not show markedly different phenotypes from those of the wild-type strain. The agsB disruption strains formed dispersed hyphal cells under liquid culture conditions, regardless of the agsA genetic background. Dispersed hyphal cells were also observed in liquid culture of the CagsB strains when agsB expression was repressed, whereas these strains grew normally in plate culture even under the agsB-repressed conditions. Fractionation of the cell wall based on the alkali solubility of its components, quantification of sugars, and 13C-NMR spectroscopic analysis revealed that α-1,3-glucan was the main component of the alkali-soluble fraction in the wild-type and agsA disruption strains, but almost no α-1,3-glucan was found in the alkali-soluble fraction derived from either the agsB disruption strain or the CagsB strain under the agsB-repressed conditions, regardless of the agsA genetic background. Taken together, our data demonstrate that the two AGS genes are dispensable in A. nidulans, but that AgsB is required for normal growth characteristics under liquid culture conditions and is the major AGS in this species. 相似文献