全文获取类型
收费全文 | 661篇 |
免费 | 36篇 |
出版年
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 12篇 |
2016年 | 12篇 |
2015年 | 14篇 |
2014年 | 18篇 |
2013年 | 43篇 |
2012年 | 36篇 |
2011年 | 42篇 |
2010年 | 30篇 |
2009年 | 23篇 |
2008年 | 32篇 |
2007年 | 32篇 |
2006年 | 32篇 |
2005年 | 30篇 |
2004年 | 29篇 |
2003年 | 24篇 |
2002年 | 30篇 |
2001年 | 16篇 |
2000年 | 14篇 |
1999年 | 22篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1970年 | 6篇 |
1969年 | 2篇 |
排序方式: 共有697条查询结果,搜索用时 15 毫秒
131.
Abstract: Specificities of the cholesterol-esterifying enzyme and the three cholesterol esterases in rat brain with respect to the chain length of fatty acids were examined. For each of the hydrolases, activities toward cholesteryl lignocerate and cerotate were generally less than 1% of that toward cholesteryl oleate. However, both lignoceric and cerotic acids were esterified at rates approximately 10% of that for oleic acid. In postmortem human control and adrenoleukodystrophy brains, the esterifying activity toward cerotic acid was on the average 25% of that toward oleic acid. The abnormal accumulation of cholesterol esters with very long chain fatty acids observed in adrenoleukodystrophy can therefore occur in the absence of deficient activities of the cholesterol esterases, if the free fatty acid pool of the brain contains an abnormal amount of very long chain fatty acids. 相似文献
132.
133.
134.
H Ehrenreich R W Anderson Y Ogino P Rieckmann T Costa G P Wood J E Coligan J H Kehrl A S Fauci 《The New biologist》1991,3(2):135-141
Observations that primary rat astrocytes express high-affinity binding sites for endothelins and, in addition, are capable of producing not only endothelin-3 but also endothelin-1 prompted the investigation of a possible relation between endothelin peptides and receptors in these cells. Sarafotoxin S6b, an endothelin receptor agonist, was used as a tool to study endothelin receptor-mediated changes in the secretion of endothelin-1 and -3. The effects of sarafotoxin S6b and endothelin-1 in stimulating inositolphospholipid turnover as well as in inducing AP1 in primary astrocyte cultures were found to be similar. A low cross-reactivity of sarafotoxin S6b with endothelin-1 and -3 in the endothelin radioimmunoassays used here, along with a distinctly different elution position in high-performance liquid chromatography, allowed a clear discrimination between sarafotoxin and endothelins in the culture media. Stimulation of primary rat astrocytes with 10(-7) M sarafotoxin S6b for 1 hour resulted in a substantial increase in endothelin-1 immunoreactivity in the medium. This immunoreactivity reached a peak at 3 hours and showed no further increase after 8 and 24 hours. Treatment of our cultures with phorbol myristate acetate, lipopolysaccharide, tumor necrosis factor alpha, and norepinephrine for 24 hours led to only a moderate elevation of endothelin-1 immunoreactivity. Immunoreactive endothelin-3 was not affected by any of the treatments tested. Thus, our data suggest that endothelins in primary rat astrocytes are subject to selective autoregulation, as demonstrated by the potentiation of endothelin-1 secretion after activation of glial endothelin receptors. 相似文献
135.
Clinical application of autologous cultured epithelia for the treatment of burn wounds and burn scars 总被引:4,自引:0,他引:4
N Kumagai H Nishina H Tanabe T Hosaka H Ishida Y Ogino 《Plastic and reconstructive surgery》1988,82(1):99-110
This report presents our experience with autologous cultured human epithelia grafting on burn wounds, burn scars, and skin-graft donor sites in seven patients. Dispersed epidermal cells were cultured with 3T3 cells treated with mitomycin C. After 2 to 3 weeks, cultured epithelia (total 350 to 2250 cm2) were grafted to the wound. The results showed that cultured epithelia grafts did not take so completely compared to the meshed skin grafts used for the coverage of burn wounds. However, cultured grafts placed on aseptic wounds adhered well and showed good appearance. In the histologic findings, normal differentiation of epidermal cells was found. Cultured grafts were bordered from subepidermal granulative tissue with basement membrane. A rete ridge and the adnexal structures were absent in the specimens that adhered to the burn wounds. However, in the specimens that took on abraded wounds, a gently sloping rete ridge and elastic fibers were seen. The histologic findings showed structures resembling normal skin. 相似文献
136.
Akira Iwashima Mieko Kobayashi Kaname Saida Hiroshi Kagamu Shinichi Ohashi Masaaki Arakawa Youji Mitsui 《In vitro cellular & developmental biology. Animal》1997,33(10):751-756
Summary Effects of endothelin (ET) family peptides and their derivatives on cellular contraction and calcium-ion level were examined
by using cultured human vascular smooth muscle cells (VSM). Contraction of cultured human VSM, isolated from human fetal aortic
segments, was induced within 1 min after the treatment with ET-1 (100 nM) as seen in the changes of cytosolic calcium-ion localization. In parallel with the cell contraction, cytosolic calcium-ion
level in the human VSM increased very rapidly and then dropped with some oscillation as determined by Anchorage Cell Analyzing
System. It was noted that transient calcium-ion mobilization rather than sustained calcium-ion influx was significant in the
contraction of cultured human VSM. Vasoactive intestinal contractor (VIC), three amino acids different from ET-1, had less
activity in increase of intracellular calcium-ion level and in percent of response cells than ET-1, ET-2, and VIC-S4L6 (one
amino acid different from ET-1). EC50 of ET-1, VIC-S4L6, ET-2, and VIC were 0.5 nM, 0.6 nM, 2.0 nM, and 20 nM, respectively. VIC-like peptide (VIC-LP), 16 amino acids fragment of VIC precursor protein, had no effect with a single administration
of up to 10 μM. However, the increase in calcium-ion level by VIC was suppressed with a prior treatment of cells with high concentration
(10 μM) of VIC-LP. The establishment of cultured human VSM for the simultaneous examination of the contraction and calcium-ion level
will provide a new system to study signal transduction of vasocontractor peptides. 相似文献
137.
138.
To examine the disease state of cold constitution, physiological measurements of the foot were conducted by investigating thermal sensations under an environmental condition of 25 degrees C-26 degrees C (neutral temperature) in 29 young women with and without cold constitution. The subjects were classified into 3 groups according to their experiences with cold constitution: cold constitution, intermediate, and normal groups. Foot skin temperature was measured by thermography. Thermal sensations were measured on the dorsum of the left foot using a thermal stimulator. Cold and warm spots on the dorsum of the right foot were ascertained. Thermal stimulation was delivered by a copper probe. No significant differences in foot skin temperature among these 3 groups were identified as measured in a laboratory under neutral temperature conditions. However, the mean warm sensation threshold was +6.3+/-1.09 degrees C (mean+/-SEM) for the cold constitution group (n=14), +3.4+/-2.10 degrees C (mean+/-SEM) for the intermediate group (n=7), and -0.25+/-1.96 degrees C (mean+/-SEM) for the normal group (n=6). The difference was significant between the cold constitution and normal groups. No significant differences among the 3 groups were found in the cold sensation threshold. This may be attributable to the distribution of thermal receptors and to chronically reduced blood flow in subcutaneous tissues, where the skin temperature receptors responsible for temperature sensation are located. 相似文献
139.
Doukyu N Yamagishi W Kuwahara H Ogino H Furuki N 《Extremophiles : life under extreme conditions》2007,11(6):781-788
A bacterium that secretes maltooligosaccharide-forming amylase in a medium containing 12.5% (vol/vol) dimethylsulfoxide (DMSO)
was isolated and identified as Brachybacterium sp. strain LB25. The amylase of the strain was purified from the culture supernatant, and its molecular mass was 60 kDa.
The enzyme was stable at pH 7.0–8.5 and active at pH 6.0–7.5. The optimum temperature at pH 7.0 was 35°C in the presence of
5 mM CaCl2. The enzyme hydrolyzed starch to produce maltotriose primarily. The enzyme was active in the presence of various organic
solvents. Its yield and product selectivity of maltooligosaccharides in the presence of DMSO or ethanol were compared with
those of the industrial maltotriose-forming amylase from Microbacterium imperiale. Both enzymes improved the production selectivity of maltotriose by the addition of DMSO or ethanol. However, the total maltooligosaccharide
yield in the presence of the solvents was higher for LB25 amylase than for M. imperiale amylase. 相似文献
140.
Hiromitsu Kanamori Genzou Takemura Kazuko Goto Akiko Tsujimoto Atsushi Mikami Atsushi Ogino Takatomo Watanabe Kentaro Morishita Hideshi Okada Masanori Kawasaki Mitsuru Seishima Shinya Minatoguchi 《Autophagy》2015,11(7):1146-1160
Little is known about the association between autophagy and diabetic cardiomyopathy. Also unknown are possible distinguishing features of cardiac autophagy in type 1 and type 2 diabetes. In hearts from streptozotocin-induced type 1 diabetic mice, diastolic function was impaired, though autophagic activity was significantly increased, as evidenced by increases in microtubule-associated protein 1 light chain 3/LC3 and LC3-II/-I ratios, SQSTM1/p62 (sequestosome 1) and CTSD (cathepsin D), and by the abundance of autophagic vacuoles and lysosomes detected electron-microscopically. AMP-activated protein kinase (AMPK) was activated and ATP content was reduced in type 1 diabetic hearts. Treatment with chloroquine, an autophagy inhibitor, worsened cardiac performance in type 1 diabetes. In addition, hearts from db/db type 2 diabetic model mice exhibited poorer diastolic function than control hearts from db/+ mice. However, levels of LC3-II, SQSTM1 and phosphorylated MTOR (mechanistic target of rapamycin) were increased, but CTSD was decreased and very few lysosomes were detected ultrastructurally, despite the abundance of autophagic vacuoles. AMPK activity was suppressed and ATP content was reduced in type 2 diabetic hearts. These findings suggest the autophagic process is suppressed at the final digestion step in type 2 diabetic hearts. Resveratrol, an autophagy enhancer, mitigated diastolic dysfunction, while chloroquine had the opposite effects in type 2 diabetic hearts. Autophagy in the heart is enhanced in type 1 diabetes, but is suppressed in type 2 diabetes. This difference provides important insight into the pathophysiology of diabetic cardiomyopathy, which is essential for the development of new treatment strategies. 相似文献