全文获取类型
收费全文 | 407篇 |
免费 | 30篇 |
出版年
2022年 | 9篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 15篇 |
2014年 | 20篇 |
2013年 | 16篇 |
2012年 | 29篇 |
2011年 | 15篇 |
2010年 | 19篇 |
2009年 | 15篇 |
2008年 | 19篇 |
2007年 | 13篇 |
2006年 | 16篇 |
2005年 | 19篇 |
2004年 | 22篇 |
2003年 | 21篇 |
2002年 | 17篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 2篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有437条查询结果,搜索用时 15 毫秒
431.
D Yamashiro C H Li P Nicolas R G Hammonds 《International journal of peptide and protein research》1982,19(4):348-353
A double-headed analog of human beta-endorphin (betah-EP), N,N'-bis (beta-endorphinyl)-cystine (II), has been synthesized by the solid-phase method, along with betah-EP-Cys(CH2CONH2)-OH (I) and [Tyr31]-betah-EP (III). Their relative potencies in a radioreceptor-binding assay were: betah-EP, 100; II, 235; I, 170; and III, 204. In the tail-flick test for analgesic activity their relative potencies were: betah-EP, 100; II, 86; I, 93; and III, 116. 相似文献
432.
433.
Takahiro Yamashiro Tomoya Yasujima Hamid M. Said Hiroaki Yuasa 《The Journal of biological chemistry》2020,295(50):16998
SLC19A2 and SLC19A3, also known as thiamine transporters (THTR) 1 and 2, respectively, transport the positively charged thiamine (vitamin B1) into cells to enable its efficient utilization. SLC19A2 and SLC19A3 are also known to transport structurally unrelated cationic drugs, such as metformin, but whether this charge selectivity extends to other molecules, such as pyridoxine (vitamin B6), is unknown. We tested this possibility using Madin-Darby canine kidney II (MDCKII) cells and human embryonic kidney 293 (HEK293) cells for transfection experiments, and also using Caco-2 cells as human intestinal epithelial model cells. The stable expression of SLC19A2 and SLC19A3 in MDCKII cells (as well as their transient expression in HEK293 cells) led to a significant induction in pyridoxine uptake at pH 5.5 compared with control cells. The induced uptake was pH-dependent, favoring acidic conditions over neutral to basic conditions, and protonophore-sensitive. It was saturable as a function of pyridoxine concentration, with an apparent Km of 37.8 and 18.5 μm, for SLC19A2 and SLC19A3, respectively, and inhibited by the pyridoxine analogs pyridoxal and pyridoxamine as well as thiamine. We also found that silencing the endogenous SLC19A3, but not SLC19A2, of Caco-2 cells with gene-specific siRNAs lead to a significant reduction in carrier-mediated pyridoxine uptake. These results show that SLC19A2 and SLC19A3 are capable of recognizing/transporting pyridoxine, favoring acidic conditions for operation, and suggest a possible role for these transporters in pyridoxine transport mainly in tissues with an acidic environment like the small intestine, which has an acidic surface microclimate. 相似文献
434.
Hai Feng Wang Naoki Isobe Kanako Kumamoto Hideaki Yamashiro Yasuhisa Yamashita Takato Terada 《Reproductive biology and endocrinology : RB&E》2006,4(1):4-9
Background
The objective of this study was to investigate whether the steroid hormone(s) secreted from cumulus-oocyte complexes (COCs) is a prerequisite for bovine oocyte maturation and cumulus expansion using aminoglutethimide (AGT), a P450 cholesterol side-chain cleavage inhibitor. 相似文献435.
D Yamashiro C H Li M Westphal 《International journal of peptide and protein research》1984,24(5):520-524
Three analogs of human beta-endorphin (beta h-ER) were synthesized by the solid-phase method: [Gln8,Trp27]-beta h-EP (I), [Gln8,Arg9,Trp27]-beta h-EP (II), and [Gln9,Arg11,Trp27]-beta h-EP (III). Radioreceptor binding assay with use of tritiated beta h-EP as primary ligand gave relative potencies as follows: beta h-EP, 100;I, 778;II, 467;III, 449. Relative potencies in an analgesic assay were: beta h-EP, 100;I, 114;II, 165;III, 83. The 8-11 segment of beta h-EP can tolerate a net increase in charge of +2 without diminishing analgesic potency. The substitution of Glu8 may be one of the more dependable means of designing beta-endorphin antagonists. 相似文献
436.
Synthesis and radioreceptor binding activity of turkey beta-endorphin and deacetylated salmon endorphin 总被引:2,自引:0,他引:2
D Yamashiro P Ferrara C H Li 《International journal of peptide and protein research》1980,16(1):75-78
Des-acetylated salmon endorphin and turkey beta-endorphin have been synthesized by the solid-phase method. Relative opiate activities in a radioreceptor binding assay are: human beta-endorphin, 100; des-acetylated salmon endorphin, 169; turkey beta-endorphin, 94. Thus, non-mammalian endorphins can show high activity in a mammalian assay system. 相似文献
437.
Hiroki Takakuwa Tetsu Yamashiro Mai Q. Le Lien S. Phuong Hiroichi Ozaki Ryota Tsunekuni Tatsufumi Usui Hiroshi Ito Tsuyoshi Yamaguchi Toshihiro Ito Toshiyuki Murase Etsuro Ono Koichi Otsuki 《Microbiology and immunology》2010,54(1):58-62
To estimate the prevalence of influenza A subtype H5N1 viruses among domestic ducks in the period between October and November 2006 when H5N1 outbreaks had been absent, 1106 healthy ducks raised in northern Vietnam were collected. Inoculation of all throat and cloacae samples into embryonated eggs resulted in the isolation of subtype H3N8 in 13 ducks, but not H5N1 viruses. Serological analyses demonstrated that five ducks (0.45%) solely developed H5N1 subtype-specific hemagglutinin-inhibiting and neuraminidase-inhibiting antibodies together with anti-non-structural protein 1 antibodies. The results suggested that the ducks were naturally infected with H5N1 viruses when obvious H5N1 outbreaks were absent. 相似文献