全文获取类型
收费全文 | 657篇 |
免费 | 28篇 |
专业分类
685篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 17篇 |
2015年 | 23篇 |
2014年 | 24篇 |
2013年 | 38篇 |
2012年 | 37篇 |
2011年 | 47篇 |
2010年 | 22篇 |
2009年 | 25篇 |
2008年 | 46篇 |
2007年 | 56篇 |
2006年 | 41篇 |
2005年 | 40篇 |
2004年 | 43篇 |
2003年 | 43篇 |
2002年 | 45篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有685条查询结果,搜索用时 15 毫秒
31.
Maruyama S Miyajima N Bohgaki M Tsukiyama T Shigemura M Nonomura K Hatakeyama S 《Molecular and cellular biochemistry》2008,307(1-2):73-82
Ubiquitylation appears to be involved in the membrane trafficking system including endocytosis, exocytosis, and ER-to-Golgi
transport. We found that PIRH2, which was identified as an interacting protein for androgen receptor or p53, interacts with
and ubiquitylates the ε-subunit of coatmer complex, ε-COP. PIRH2 promotes the ubiquitylation of ε-COP in vitro and in vivo
and consequently promotes the degradation of ε-COP. The interaction between PIRH2 and ε-COP is affected by the presence of
androgen, and PIRH2 in the presence of androgen promotes ubiquitylation of ε-COP in vivo. Furthermore, overexpression of the
wild type of PIRH2 in prostate cancer cells causes downregulation of the secretion of prostate-specific antigen (PSA), a secretory
protein in prostate epithelial cells and one of diagnostic markers for prostate cancer. Our results indicate that PIRH2 functions
as a regulator for COP I complex. 相似文献
32.
Iwamiya S Yamauchi K Shiraishi K Takada M Sato M 《Journal of PHYSIOLOGICAL ANTHROPOLOGY and Applied Human Science》2004,23(6):267-271
The government of Fukuoka City conducted a survey to determine the effectiveness of an audio-guidance system for the blind. The blind participants confirmed the usefulness of the audio-guidance. In addition, the blind participants and the walking instructors also provided various comments and suggestions for the better utilization of audio-guidance systems for smoother transportation. In order for the participants to be able to recognize auditory signals, it was important to be able to hear them at their peak volumes. To understand the actual meaning of announcements, however, the average volumes of the signals were more important than their peak volumes. The blind participants suggested that auditory signals and announcements should provide short and simple messages. The walking instructors provided comments regarding the placement of loudspeakers to enhance auditory localization. They recommended hanging the loudspeakers from ceilings located in front of passengers. Furthermore, the necessity of controlling excess reverberations was indicated in order to better enable blind citizens to recognize and localize the auditory signals. It was suggested that using different auditory signals for different purposes and places was effective for smoother transportation. 相似文献
33.
Coxiella burnetii is the agent of the worldwide zoonosis, Q fever. The in vitro susceptibility to tetracycline and fluoroquinolones of Japanese isolates of C. burnetii was evaluated for the first time. The MICs against Japanese isolates were almost the same as the MICs against the foreign reference isolates. The results suggest that the common antibiotics therapy for Q fever used in other countries is also effective for Japanese Q fever patients. 相似文献
34.
Ohe Y Ohnishi H Okazawa H Tomizawa K Kobayashi H Okawa K Matozaki T 《Biochemical and biophysical research communications》2003,308(4):719-725
Membrane glycoproteins of neural cells play crucial roles in axon guidance, synaptogenesis, and neuronal transmission. We have here characterized membrane glycoproteins containing terminal alpha-mannose residues in rat brain membranes. Affinity purification using Galanthus nivalis agglutinin, that is highly specific for terminal alpha-mannose residues, revealed a 50-kDa protein as well as 80-kDa SHPS-1 and 45-kDa beta2 subunit of Na,K-ATPase in rat brain membranes. Combination of N-terminal peptide sequencing and mass spectrometry indicated that the 50-kDa protein was rat nucleotide pyrophosphatase-5 (NPP-5). In contrast to other NPPs, NPP-5 was a type-I transmembrane protein. Northern blot analysis showed that NPP-5 was highly expressed in brain, but also expressed in other peripheral tissues. However, we could not detect either the NPP activity or the lysophospholipase D activity in the immunoprecipitates with antibodies to NPP-5 from rat brain membranes. These data, therefore, suggest that NPP-5 is a neural oligomannosidic glycoprotein that may participate in neural cell communications. 相似文献
35.
Oda A Wada I Miura K Okawa K Kadoya T Kato T Nishihara H Maeda M Tanaka S Nagashima K Nishitani C Matsuno K Ishino M Machesky LM Fujita H Randazzo P 《The Journal of biological chemistry》2003,278(8):6456-6460
Searching for proteins in platelets that can interact with the N-terminal SH3 domain of CrkL (using a combination of a pull-down assay followed by mass spectrometry), we have found that human platelets express an ADP-ribosylation factor (Arf)-specific GTPase-activating protein (GAP), ASAP1, as a CrkL-binding protein. In spreading platelets, most endogenous ASAP1 is localized at peripheral focal adhesions. To determine the physiologic significance of the CrkL-ASAP1 association, we overexpressed CrkL, ASAP1, or both in combination in COS7 cells. Unlike endogenous ASAP1 in platelets, overexpressed ASAP1 showed diffuse cytoplasmic distribution. However, when co-expressed with wild-type CrkL, both endogenous and expressed ASAP1 accumulated at CrkL-induced focal adhesions. An SH2-mutated CrkL, which cannot localize at focal adhesions, failed to recruit ASAP1 into focal adhesions. Thus, CrkL appears to be a lynchpin between ASAP1 and peripheral focal adhesions. 相似文献
36.
Motomu Nishioka Katsuya Nakai Masato Miyake Yasuo Asada Masahito Taya 《Biotechnology letters》2001,23(14):1095-1099
Synechococcus sp. MA19, grown autotrophically under phosphate-limited conditions at 50 °C, produced poly--hydroxybutyrate (PHB) when intracellular phosphate content was 0.043–0.076mmol per g of cellular components. In the culture for 260h using Ca3(PO4)2 as a phosphate source, strain MA19 accumulated PHB at 55% (w/w) of the dry cells and the amount of PHB produced was 2.4gl–1 which was almost twice that without Ca3(PO4)2 addition. 相似文献
37.
Sasano N Vesely AE Hayano J Sasano H Somogyi R Preiss D Miyasaka K Katsuya H Iscoe S Fisher JA 《American journal of physiology. Heart and circulatory physiology》2002,282(3):H973-H976
Respiratory sinus arrhythmia (RSA) may improve the efficiency of pulmonary gas exchange by matching the pulmonary blood flow to lung volume during each respiratory cycle. If so, an increased demand for pulmonary gas exchange may enhance RSA magnitude. We therefore tested the hypothesis that CO2 directly affects RSA in conscious humans even when changes in tidal volume (V(T)) and breathing frequency (F(B)), which indirectly affect RSA, are prevented. In seven healthy subjects, we adjusted end-tidal PCO2 (PET(CO2)) to 30, 40, or 50 mmHg in random order at constant V(T) and F(B). The mean amplitude of the high-frequency component of R-R interval variation was used as a quantitative assessment of RSA magnitude. RSA magnitude increased progressively with PET(CO2) (P < 0.001). Mean R-R interval did not differ at PET(CO2) of 40 and 50 mmHg but was less at 30 mmHg (P < 0.05). Because V(T) and F(B) were constant, these results support our hypothesis that increased CO2 directly increases RSA magnitude, probably via a direct effect on medullary mechanisms generating RSA. 相似文献
38.
39.
Communication between different signaling pathways enables cells to coordinate the responses to diverse environmental signals. Activation of the transmembrane growth factor precursors plays a critical role in this communication and often involves metalloprotease-mediated proteolysis. Stimulation of G protein-coupled receptors (GPCR) transactivates the EGF receptors (EGFRs), which occurs via a metalloprotease-dependent cleavage of heparin-binding EGF (HB-EGF). However, the metalloprotease mediating the transactivation remains elusive. We show that the integral membrane metalloprotease Kuzbanian (KUZ; ADAM10), which controls Notch signaling in Drosophila, stimulates GPCR transactivation of EGFR. Upon stimulation of the bombesin receptors, KUZ increases the docking and activation of adaptors Src homology 2 domain-containing protein and Gab1 on the EGFR, and activation of Ras and Erk. In contrast, transfection of a protease domain-deleted KUZ, or blocking endogenous KUZ by morpholino antisense oligonucleotides, suppresses the transactivation. The effect of KUZ on shedding of HB-EGF and consequent transactivation of the EGFR depends on its metalloprotease activity. GPCR activation enhances the association of KUZ and its substrate HB-EGF with tetraspanin CD9. Thus, KUZ regulates the relay between the GPCR and EGFR signaling pathways. 相似文献
40.
Ikuta K Yamada T Shimomura T Kuratsune H Kawahara R Ikawa S Ohnishi E Sokawa Y Fukushi H Hirai K Watanabe Y Kurata T Kitani T Sairenji T 《Microbes and infection / Institut Pasteur》2003,5(12):1096-1102
To investigate the association of viral infections with chronic fatigue syndrome (CFS), we assayed 2', 5'-oligoadenylate synthetase (2-5AS) activities in peripheral blood mononuclear cells from CFS patients in Japan. These patients were diagnosed in two hospitals, H1 and H2, located in different areas of the country. The activities were detected in 19 (86%) and 7 (32%) of each of the 22 patients in H1 and H2, respectively, while they were detected in only four (11%) out of the 38 healthy controls. IFN-alpha was similarly detected in a few CFS patients and healthy controls. We also assayed the antibody titers against Epstein-Barr virus (EBV) and Coxiella burnetii in these patients. The EBV anti-EA-IgG antibodies were detected in two (9%) and seven (32%) of each of the 22 patients in H1 and H2, respectively. Anti-C. burnetii IgG antibodies were detected in six (27%) out of 22 patients in H1 but not in 22 patients in H2, while they were detected in one (11%) of the nine healthy controls. Some CFS patients may be associated with EBV or C. burnetii infection. There were some statistical correlations between the 2-5AS activities and antibody titers of EA-IgG (P < 0.05, Student's t-test) but not to the antibody titers of C. burnetii. The up-regulation of 2-5AS activities suggests immunological dysfunctions with some virus infections in the CFS patients. Our results indicate that 2-5AS activities are useful for a diagnostic marker of CFS and for exploring the complicated pathogenesis of CFS. 相似文献