全文获取类型
收费全文 | 1301篇 |
免费 | 42篇 |
专业分类
1343篇 |
出版年
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 23篇 |
2015年 | 26篇 |
2014年 | 37篇 |
2013年 | 115篇 |
2012年 | 62篇 |
2011年 | 78篇 |
2010年 | 27篇 |
2009年 | 37篇 |
2008年 | 84篇 |
2007年 | 66篇 |
2006年 | 66篇 |
2005年 | 66篇 |
2004年 | 78篇 |
2003年 | 78篇 |
2002年 | 62篇 |
2001年 | 23篇 |
2000年 | 20篇 |
1999年 | 23篇 |
1998年 | 15篇 |
1997年 | 21篇 |
1996年 | 21篇 |
1995年 | 14篇 |
1994年 | 13篇 |
1993年 | 9篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 18篇 |
1989年 | 16篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 11篇 |
1978年 | 14篇 |
1977年 | 5篇 |
1975年 | 6篇 |
1973年 | 9篇 |
1972年 | 7篇 |
1970年 | 6篇 |
1966年 | 7篇 |
排序方式: 共有1343条查询结果,搜索用时 15 毫秒
71.
Yamamoto K Kawada T Kamiya A Takaki H Sugimachi M Sunagawa K 《American journal of physiology. Heart and circulatory physiology》2005,289(4):H1604-H1609
Elucidation of the interaction between the muscle mechanoreflex and the arterial baroreflex is essential for better understanding of sympathetic regulation during exercise. We characterized the effects of these two reflexes on sympathetic nerve activity (SNA) in anesthetized rabbits (n = 7). Under open-loop baroreflex conditions, we recorded renal SNA at carotid sinus pressure (CSP) of 40, 80, 120, or 160 mmHg while passively stretching the hindlimb muscle at muscle tension (MT) of 0, 2, 4, or 6 kg. The MT-SNA relationship at CSP of 40 mmHg approximated a straight line. Increase in CSP from 40 to 120 and 160 mmHg shifted the MT-SNA relationship downward and reduced the response range (the difference between maximum and minimum SNA) to 43 +/- 10% and 19 +/- 6%, respectively (P < 0.01). The CSP-SNA relationship at MT of 0 kg approximated a sigmoid curve. Increase in MT from 0 to 2, 4, and 6 kg shifted the CSP-SNA relationship upward and extended the response range to 133 +/- 8%, 156 +/- 14%, and 178 +/- 15%, respectively (P < 0.01). A model of algebraic summation, i.e., parallel shift, with a threshold of SNA functionally reproduced the interaction of the two reflexes (y = 1.00x - 0.01; r(2) = 0.991, root mean square = 2.6% between estimated and measured SNA). In conclusion, the response ranges of SNA to baroreceptor and muscle mechanoreceptor input changed in a manner that could be explained by a parallel shift with threshold. 相似文献
72.
Kevin Montagne Raphael Plasson Yasuyuki Sakai Teruo Fujii Yannick Rondelez 《Molecular systems biology》2011,7(1)
Living organisms perform and control complex behaviours by using webs of chemical reactions organized in precise networks. This powerful system concept, which is at the very core of biology, has recently become a new foundation for bioengineering. Remarkably, however, it is still extremely difficult to rationally create such network architectures in artificial, non‐living and well‐controlled settings. We introduce here a method for such a purpose, on the basis of standard DNA biochemistry. This approach is demonstrated by assembling de novo an efficient chemical oscillator: we encode the wiring of the corresponding network in the sequence of small DNA templates and obtain the predicted dynamics. Our results show that the rational cascading of standard elements opens the possibility to implement complex behaviours in vitro. Because of the simple and well‐controlled environment, the corresponding chemical network is easily amenable to quantitative mathematical analysis. These synthetic systems may thus accelerate our understanding of the underlying principles of biological dynamic modules. 相似文献
73.
Yoshihiro Takikawa Koji Kakutani Teruo Nonomura Yoshinori Matsuda Hideyoshi Toyoda 《Mycoscience》2011,52(3):204-209
In the present study, using a high-fidelity digital microscope, we observed the sequence of appressorial development on the
germ tubes of a powdery mildew fungus isolated from red clover leaves. Based on its morphological characteristics and rDNA
internal transcribed spacer (ITS) sequences, the fungus was identified as Erysiphe trifoliorum, and one of its isolates, designated as KRCP-4N, was used in this work. The conidial germination of isolate KRCP-4N was studied
on host (red clover) and non-host (barley) leaves, as well as on an artificial hydrophobic membrane (Parafilm). More than
90% of conidia germinated synchronously and developed dichotomous appressoria (symmetrical double-headed appressoria) on all
substrata used. On host leaves, all appressorium-forming conidia developed hyphae (colony-forming hyphae) from conidial bodies
without extending germ tubes from the tips of the appressoria. On non-host leaves and on Parafilm-covered glass slides, however,
all conidia extended germ tubes from one side of dichotomous appressoria (two-step germination). In addition to the dichotomous
appressoria, we detected a few conidia that produced hooked appressoria and extended germ tubes from the tip of the appressorium.
Penetration attempts by KRCP-4N conidia on barley leaves were impeded by papillae formed at penetration sites beneath these
two types of appressorium. From these results, we conclude that the “two-step germination” of E. trifoliorum KRCP-4N conidia is the result of an unsuccessful penetration attempt, causing diversity in appressorial shape. 相似文献
74.
Safak Yalcin Hirohiko Kuratsune Koji Yamaguchi Teruo Kitani Koichi Yamanishi 《Microbiology and immunology》1994,38(7):587-590
Peripheral blood mononuclear cells collected from 13 patients with chronic fatigue syndrome and 13 healthy controls were analyzed for the presence of human herpesvirus 6 (HHV-6) DNA by variant-specific polymerase chain reaction and dot blot hybridization. HHV-6 DNA was detected in 7 of 13 (53%) patients, and of those 7 patients, 4 were positive for HHV-6 variant A DNA and 3 were for variant B. No HHV-6 DNA was detected in the controls. Serum antibody titers to the late antigen and antibody prevalence to the early antigen of HHV-6 were significantly higher in the patient group. These results suggest active replication of HHV-6 in patients with chronic fatigue syndrome. 相似文献
75.
Anabaena variabilis cells have been cultivated in the presence of diphenylamine (12 mg/l) which inhibits the biosynthesis of β-carotene, echinenone and zeasanthin. The content of chlorophyll a is also reduced by diphenylamine. The biosynthesis of myxoxanthophyll is, however, stimulated by this reagent.
The membrane fragments prepared from Anabaena cells grown in the presence of diphenylamine have the activities of both Photosystem 1 (NADP+ reduction with DCIP-ascorbate as electron donor) and Photosystem 2 (DCIP reduction with 1,5-diphenylcarbazide as electron donor).
The fluroescence spectra of these cells at 77°K show peaks at 696 and 731 nm and a shoulder around 687 nm. The fluorescence intensity at 687 and 696 nm is higher in these cells than in normal-Anabaena cells. 相似文献
76.
Monotherapy with a novel intervenolin derivative,AS‐1934, is an effective treatment for Helicobacter pylori infection 下载免费PDF全文
77.
Hideya Hayashi Seiji Ito Teruo Tanaka Manabu Negishi Hideo Kawabe Yokohama Hiromitsu Kikuko Watanabe Osamu Hayaishi 《Prostaglandins & other lipid mediators》1987,33(4)
In view of the recent finding that prostaglandin D2 is stereospecifically converted to 9α,11β-prostaglandin F2, an isomer of prostaglandin F2α, a highly specific and sensitive radioimmunoassay for 9α,11β-prostaglandin F2 was developed and applied to determine the content of this prostaglandin in various rat tissues. Antisera against 9α-11β-prostaglandin F2 were raised in rabbits immunized with the bovine serum albumin conjugate, and [3H]9α,11β-prostaglandin F2 was enzymatically prepared from [3H]prostaglandin D2. The assay detected 9α,11β-prostaglandin F2 over the range of 20 pg to 1 ng, and the antiserum showed less than 0.04% cross-section with prostaglandin F2α, prostaglandin F2β and 9β,11β-prostaglandin F2. To avoid postmortem changes, tissues were frozen in liquid nitrogen immediately after removal. The basal level of 9α,11β-prostaglandin F2 was hardly detectable in various tissues of the rat examined, including spleen, lung, liver and brain; although it was found to be 0.31 ± 0.06 ng/g wet weight in the small intestine. During convulsion induced by pentylenetetrazole, enormous amounts of prostaglandin D2 (ca. 180 ng/g wet weight) and prostaglandin F2α (ca. 70 ng/g) were produced in the brain; however, 9α,11β-prostaglandin F2 was detected neither there nor in the blood. This result demonstrates that the conversion to 9α,11β-prostaglandin F2 is a minor pathway, if one at all, of prostaglandin D2 metabolism in the rat brain. 相似文献
78.
Tadashi Ikegami Akira Honda Teruo Miyazaki Motoyuki Kohjima Makoto Nakamuta Yasushi Matsuzaki 《Biochemical and biophysical research communications》2014
Oxidative stress and dysregulated cholesterol metabolism are characteristic features of chronic hepatitis C virus infection (CHC). Therefore, we analyzed serum oxysterol profiles in CHC patients and examined the significance of oxysterols in CHC. The concentrations of 7α-hydroxycholesterol, 4β-hydroxycholesterol and 25-hydroxycholesterol as determined by LC–ESI–MS/MS were significantly elevated by +236%, +29% and +44%, respectively, in CHC patients compared with controls. Moreover, the elevated levels were significantly decreased by anti-viral therapy using PEGylated-interferon and ribavirin for 3 months. In contrast, 24S-hydroxycholesterol, 27-hydroxycholesterol and 7α-hydroxy-4-cholesten-3-one concentrations were not affected by CHC or anti-viral treatment. These results suggest that some oxysterols that are elevated in CHC are produced by cholesterol autoxidation due to oxidative stress or inflammation in the liver. Oxysterols may represent novel targets for the inhibition of disease progression and the prevention of hepatocarcinogenesis in CHC patients. 相似文献
79.
Kazutoshi Nishijima Mai Tanaka Yusuke Sakai Chihiro Koshimoto Masatoshi Morimoto Teruo Watanabe Jianglin Fan Shuji Kitajima 《Cryobiology》2014
We investigated the effects of antifreeze protein (AFP) III supplementation on the cryopreservation of rabbit sperm cells and embryos. Ejaculated semen was collected from male Japanese white (JW) rabbits and divided into four AFP-supplemented groups (0.1 μg/ml, 1 μg/ml, 10 μg/ml, 100 μg/ml) and one control group with no AFP-supplementation. The semen samples were treated with egg-yolk HEPES extender containing 6% acetamide before the sperm was cooled from room temperature to 5 °C, then packed into sperm straws. The straws were frozen in steam of liquid nitrogen (LN2) and then preserved in the LN2. The motility of the sperm after thawing in 37 °C water was analyzed. The percentage of rapidly motile sperm in the 1 μg/ml AFP group was significantly higher than in the control group. Morulae were collected from female JW rabbits and divided into three AFP-supplemented groups (100 ng/ml, 500 ng/ml, 1000 ng/ml) and one control group. The morulae, immersed in an embryo-freezing solution (M199-HEPES containing 20% ethylene glycol, 20% dimethylsulfoxide, 10% fetal bovine serum and 0.25 M sucrose), were packed into open pulled embryo straws and vitrified in LN2. The frozen embryos were thawed in the embryo-freezing solution, and the rates of embryo survival and development to blastocyte stage were analyzed after incubation for 72 h. The development rate of the embryos in the 500 ng/ml AFP group was significantly higher than in the control group, but that in the 1000 ng/ml AFP group was significantly lower. In conclusion, the appropriate dose of AFP III increased the number of rapidly motile sperm and embryo survival following freezing and thawing. The results suggest that supplementation with AFP III can increase the efficiency of cryopreservation of rabbit sperm cells and embryos. 相似文献
80.
Taku Inohara Shun Kohsaka Naoki Sato Katsuya Kajimoto Takehiko Keida Masayuki Mizuno Teruo Takano 《PloS one》2014,9(9)