全文获取类型
收费全文 | 2694篇 |
免费 | 128篇 |
出版年
2023年 | 3篇 |
2022年 | 16篇 |
2021年 | 42篇 |
2020年 | 23篇 |
2019年 | 21篇 |
2018年 | 39篇 |
2017年 | 39篇 |
2016年 | 54篇 |
2015年 | 94篇 |
2014年 | 114篇 |
2013年 | 165篇 |
2012年 | 178篇 |
2011年 | 191篇 |
2010年 | 133篇 |
2009年 | 125篇 |
2008年 | 186篇 |
2007年 | 198篇 |
2006年 | 163篇 |
2005年 | 156篇 |
2004年 | 175篇 |
2003年 | 165篇 |
2002年 | 182篇 |
2001年 | 21篇 |
2000年 | 17篇 |
1999年 | 29篇 |
1998年 | 35篇 |
1997年 | 30篇 |
1996年 | 20篇 |
1995年 | 27篇 |
1994年 | 17篇 |
1993年 | 32篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 11篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 12篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有2822条查询结果,搜索用时 109 毫秒
961.
A novel extracellular protease of Vibrio mimicus that mediates maturation of an endogenous hemolysin
Tamaki Mizuno Ayako Nanko Yoko Maehara Sumio Shinoda Shin‐Ichi Miyoshi 《Microbiology and immunology》2014,58(9):503-512
962.
Kentaro Oh-hashi Yoshiro Kanamori Yoko Hirata Kazutoshi Kiuchi 《Cell biology and toxicology》2014,30(3):127-136
We previously demonstrated that cysteine-rich with EGF-like domains 2 (CRELD2), a novel ER stress-inducible factor, is a secretory glycoprotein; however, the stimuli that induce CRELD2 secretion have not yet been characterized. In this study, we found that the perturbation of intravesicular acidification of cytoplasmic organelles in HEK293 cells stably expressing wild-type (wt) CRELD2 induced its secretion. In particular, Concanamycin A (CMA) and Bafilomycin A1 (Baf), inhibitors of vacuolar ATPase (V-ATPase), increased the secretion of CRELD2 without relying on its C-terminal structure. The levels of secretion of EGFP-fused CRELD2 (SP-EGFP-CRELD2), which consists of EGFP following the putative signal peptide (SP) sequence of CRELD2, from COS7 cells transiently transfected with this construct were also increased after each of the treatments, but their intracellular localization was barely affected by CMA treatment. Transient overexpression of 78-kDa glucose-regulated protein (GRP78) and protein disulfide isomerase (PDI) also increased the secretion of CRELD2 from HEK293 cells expressing wt CRELD2, whereas the perturbation of intravesicular acidification did not alter the expression of GRP78 and PDI in the HEK293 cells. We further studied the roles of intracellular calcium ions and the Golgi apparatus in the secretion of CRELD2 from HEK293 cells in which intravesicular acidification was perturbed. The treatment with calcium ionophore increased the secretion of wt CRELD2, while that with BAPTA-AM, an intracellular calcium chelator, did not reduce the CMA-induced CRELD2 secretion. By contrast, treatment with brefeldin A (BFA), which inhibits the transportation of proteins from the ER to the Golgi apparatus, almost completely abolished the secretion of wt CRELD2 from the HEK293 cells. In conclusion, we demonstrated that the intravesicular acidification by V-ATPase regulates the secretion of CRELD2 without relying on the balance of intracellular calcium ions and the expression of ER chaperones such as GRP78 and PDI. These findings concerning the role of V-ATPases in modulating the secretion of CRELD2, a novel ER stress-inducible secretory factor, may provide new insights into the prevention and treatment of certain ER stress-related diseases. 相似文献
963.
964.
965.
966.
Simple generation of albino C57BL/6J mice with G291T mutation in the tyrosinase gene by the CRISPR/Cas9 system 总被引:1,自引:0,他引:1
Seiya Mizuno Tra Thi Huong Dinh Kanako Kato Saori Mizuno-Iijima Yoko Tanimoto Yoko Daitoku Yoshikazu Hoshino Masahito Ikawa Satoru Takahashi Fumihiro Sugiyama Ken-ichi Yagami 《Mammalian genome》2014,25(7-8):327-334
Single nucleotide mutations (SNMs) are associated with a variety of human diseases. The CRISPR/Cas9 genome-editing system is expected to be useful as a genetic modification method for production of SNM-induced mice. To investigate whether SNM-induced mice can be generated by zygote microinjection of CRISPR/Cas9 vector and single-stranded DNA (ssDNA) donor, we attempted to produce albino C57BL/6J mice carrying the Tyr gene SNM (G291T) from pigmented C57BL/6J zygotes. We first designed and constructed a CRISPR/Cas9 expression vector for the Tyr gene (px330-Tyr-M). DNA cleavage activity of px330-Tyr-M at the target site of the Tyr gene was confirmed by the EGxxFP system. We also designed an ssDNA donor for homology-directed repair (HDR)-mediated gene modification. The px330-Tyr-M vector and ssDNA donor were co-microinjected into the pronuclei of 224 one-cell-stage embryos derived from C57BL/6J mice. We obtained 60 neonates, 28 of which showed the ocular albinism and absence of coat pigmentation. Genomic sequencing analysis of the albino mice revealed that the target of SNM, G291T in the Tyr gene, occurred in 11 mice and one founder was homozygously mutated. The remaining albino founders without Tyr G291T mutation also possessed biallelic deletion and insertion mutants adjacent to the target site in the Tyr locus. Simple production of albino C57BL/6J mice was provided by C57BL/6J zygote microinjection with px330-Tyr-M DNA vector and mutant ssDNA (G291T in Tyr) donor. A combination of CRISPR/Cas9 vector and optional mutant ssDNA could be expected to efficiently produce novel SNM-induced mouse models for investigating human diseases. 相似文献
967.
The primary infectious source of nontuberculous mycobacteria (NTM), which are known as opportunistic pathogens, appears to be environmental exposure, and it is important to reduce the frequency of exposure from environmental sources for preventing NTM infections. In order to achieve this, the distribution and respiratory activity of NTM in the environments must be clarified. In this study, we determined the abundance of mycobacteria and respiratory active mycobacteria in the household water system of healthy volunteers using quantitative PCR and a fluorescent staining method, because household water has been considered as one of the possible infectious sources. We chose healthy volunteer households in order to lessen the effect of possible residential contamination from an infected patient. We evaluated whether each sampling site (bathroom drain, kitchen drain, bath heater pipe and showerhead) have the potential to be the sources of NTM infections. Our results indicated that drains in the bathroom and kitchen sink are the niche for Mycobacterium spp. and M. avium cells were only detected in the bathtub inlet. Both physicochemical and biologic selective pressures may affect the preferred habitat of Mycobacterium spp. Regional differences also appear to exist as demonstrated by the presence (US) or absence (Japan) of Mycobacterium spp. on showerheads. Understanding of the country specific human activities and water usage will help to elucidate the infectious source and route of nontuberculous mycobacterial disease. 相似文献
968.
Yoshihiro J. Ono Akiko Tanabe Yoko Nakamura Hikaru Yamamoto Atsushi Hayashi Tomohito Tanaka Hiroshi Sasaki Masami Hayashi Yoshito Terai Masahide Ohmichi 《PloS one》2014,9(12)
Although endometriosis is suspected to be a cause of premature ovarian insufficiency (POI), the mechanism(s) underlying this process have not been elucidated. Recently, androgens were shown to promote oocyte maturation and to play a role in folliculogenesis. In addition, several reports have documented low testosterone levels in the follicular fluid obtained from endometriosis patients. We therefore examined whether the low levels of serum testosterone are associated with the apoptosis of granulosa cells in follicles obtained from endometriosis patients. Serum samples were collected from 46 patients with endometriosis and from 62 patients without endometriosis who received assisted reproductive therapy. Specimens of the ovaries obtained from 10 patients with endometrioma were collected using laparoscopy. The mean serum testosterone concentration in the patients with endometriosis was significantly lower than that observed in the patients without endometriosis. Furthermore, high expression of a pro-apoptotic Bcl-2 member, BimEL, in the follicles was found to be associated with a low serum testosterone level. We clarified the underlying mechanisms using a basic approach employing human immortalized granulosa cells derived from a primary human granulosa cell tumor, the COV434 cell line. The in vitro examination demonstrated that testosterone inhibited apoptosis induced by sex steroids depletion via the PI3K/Akt-FoxO3a pathway in the COV434 cells. In conclusion, we elucidated the mechanism underlying the anti-apoptotic effects of testosterone on granulosa cells, and found that a low-testosterone status is a potentially important step in the development of premature ovarian insufficiency in patients with endometriosis. 相似文献
969.
Haruyo Nakajima-Adachi Akira Kikuchi Yoko Fujimura Kyoko Shibahara Tsuyoshi Makino Masae Goseki-Sone Miran Kihara-Fujioka Tomonori Nochi Yosuke Kurashima Osamu Igarashi Masafumi Yamamoto Jun Kunisawa Masako Toda Shuichi Kaminogawa Ryuichiro Sato Hiroshi Kiyono Satoshi Hachimura 《PloS one》2014,9(10)
Background and Objective
To improve the efficacy and safety of tolerance induction for food allergies, identifying the tissues responsible for inducing intestinal inflammation and subsequent oral tolerance is important. We used OVA23-3 mice, which express an ovalbumin-specific T-cell receptor, to elucidate the roles of local and systemic immune tissues in intestinal inflammation.Methods and Results
OVA23-3 mice developed marked enteropathy after consuming a diet containing egg white (EW diet) for 10 days but overcame the enteropathy (despite continued moderate inflammation) after receiving EW diet for a total of 28 days. Injecting mice with anti-IL-4 antibody or cyclosporine A confirmed the involvement of Th2 cells in the development of the enteropathy. To assess the individual contributions of Peyer’s patches (PPs), mesenteric lymph nodes (MLNs), and the spleen to the generation of effector CD4+ T-cells, we analyzed the IL-4 production, proliferation in response to ovalbumin, and CD4+ T-cell numbers of these tissues. EW feeding for 10 days induced significant IL-4 production in PPs, the infiltration of numerous CD4+ T-cells into MLNs, and a decrease in CD4+ T-cell numbers in spleen. On day 28, CD4+ T-cells from all tissues had attenuated responses to ovalbumin, suggesting tolerance acquisition, although MLN CD4+ T-cells still maintained IL-4 production with proliferation. In addition, removal of MLNs but not the spleen decreased the severity of enteropathy and PP-disrupted mice showed delayed onset of EW-induced inflammatory responses. Disruption of peripheral lymphoid tissues or of both PPs and MLNs almost completely prevented the enteropathy.Conclusions
PPs and MLNs coordinately promote enteropathy by generating effector T-cells during the initial and exacerbated phases, respectively; the spleen is dispensable for enteropathy and shows tolerogenic responses throughout EW-feeding. The regulation of PPs may suppress the initiation of intestinal inflammation, subsequently restricting MLNs and inhibiting the progression of food-allergic enteropathy. 相似文献970.