首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   961篇
  免费   27篇
  国内免费   3篇
耳鼻咽喉   97篇
儿科学   7篇
妇产科学   2篇
基础医学   84篇
口腔科学   26篇
临床医学   49篇
内科学   195篇
皮肤病学   3篇
神经病学   91篇
特种医学   6篇
外科学   119篇
综合类   9篇
预防医学   13篇
眼科学   8篇
药学   173篇
中国医学   18篇
肿瘤学   91篇
  2022年   8篇
  2021年   13篇
  2020年   11篇
  2019年   16篇
  2018年   11篇
  2017年   8篇
  2016年   10篇
  2015年   4篇
  2014年   12篇
  2013年   21篇
  2012年   34篇
  2011年   38篇
  2010年   31篇
  2009年   16篇
  2008年   37篇
  2007年   46篇
  2006年   45篇
  2005年   52篇
  2004年   52篇
  2003年   39篇
  2002年   67篇
  2001年   46篇
  2000年   36篇
  1999年   32篇
  1998年   12篇
  1997年   8篇
  1996年   10篇
  1995年   3篇
  1994年   11篇
  1992年   34篇
  1991年   28篇
  1990年   25篇
  1989年   27篇
  1988年   26篇
  1987年   27篇
  1986年   23篇
  1985年   11篇
  1984年   8篇
  1983年   5篇
  1982年   3篇
  1981年   3篇
  1979年   6篇
  1973年   4篇
  1972年   5篇
  1971年   3篇
  1970年   2篇
  1969年   4篇
  1968年   2篇
  1967年   2篇
  1966年   6篇
排序方式: 共有991条查询结果,搜索用时 15 毫秒
1.
Various tannins and related compounds were compared for their ability to stimulate the iodination (incorporation of radioactive iodine into an acid-insoluble fraction) of human peripheral blood monocytes. The stimulating activity of most of the monomeric and dimeric hydrolyzable tannins was generally higher than that of the trimeric and tetrameric compounds. Compounds that had dehydrohexahydroxydiphenoyl or chebuloyl groups had considerably less activity than those that had other functional groups (hexahydroxydiphenoyl, valoneoyl, dehydrodigalloyl, isodehydrodigalloyl, lactonized valoneoyl, hellinoyl, euphorbinoyl, dehydroeuphorbinoyl or woodfordinoyl group). The methylated derivative, nonacosa-O-methylcoriariin A, was essentially inactive, suggesting the requirement of a phenolic hydroxyl group. Three condensed tannins ((-)-epicatechin 3-O-gallate (ECG)-dimer, ECG-trimer and ECG-tetramer) significantly stimulated both monocyte iodination and their interleukin-1-like factor production. The results suggest the dependence of stimulation of monocyte iodination by tannins and related polyphenols on molecular weight.  相似文献   
2.
Hyperthermia was induced for the treatment of invasive bladder carcinoma in order to study its usefulness. The subjects were 12 cases of invasive bladder cancer; including 5 cases of T2, 3 cases of T3, 2 cases of T4, and 2 cases of recurrence after total cystectomy. As previous treatment, 4 patients received radiotherapy and the other received TUR, systemic chemotherapy, and intravesical injection of anticancer drugs. For hyperthermia treatment, a Thermotron RF-8 was used for heating a deep seated tumor. Each case received hyperthermia 2 to 10 times. Combined therapy included injection of HPC-adriamycin into the urinary bladder in 5 cases, immunotherapy in 3 cases, M-VAC therapy in one case, radiotherapy in one case, radiotherapy and intra-arterial injection in one case, and Peplomycin and OK-432 local injection in one case. The treatment results showed a 75% effectiveness; with CR in 4 cases, PR in 5 cases, MR in 2 cases and PD in one case. Three patients died and 9 survived. Of four patients who had received radiotherapy as a previous treatment 3 cases obtained CR and one case MR. Therefore, it was considered that a favorable treatment effect with hyperthermia could be obtained after radiotherapy.  相似文献   
3.
Incorporation of hydroxypropylcellulose (HPC-)doxorubicin, which we developed as a mucous-membrane-adhesive drug preparation, was instilled into the urinary bladder in 10 clinical cases. Tumor of the urinary bladder was a single tumor in all 10 cases, and preclinical histology showed transitional cell carcinoma, grade 1 or 2, and a lower stage than T1. HPC-doxorubicin, 20 mg/20 ml, was administered in 5 cases, and the other 5 cases received the conventional aqueous doxorubicin, 20 mg/20 ml by way of a catheter and the urethra. Cold punch biopsy was performed after 3 days of instillation, and the incorporation of doxorubicin into both tumorous and normal tissue was measured by high-pressure liquid chromatography. After 3 days, it was found that in the HPC-doxorubicin-administered group, doxorubicin was detected in both tumorous and normal tissue, but it was not detected in either tissue after aqueous doxorubicin administration. In 5 cases of the HPC-doxorubicin group, doxorubicin levels in the tumorous and normal tissue were examined, and it was found that significantly more doxorubicin was detected in the tumorous tissues. Thus, it may be said that our HPC-doxorubicin remained longer within the urinary bladder than the conventional aqueous doxorubicin preparation. Instilled HPC-doxorubicin is more highly concentrated in the tumorous tissue than in the normal bladder tissue, and thus, HPC-compounded anticancer drugs may be therapeutically more useful.  相似文献   
4.
When heat-killed Propionibacterium acnes, a gram-positive anaerobe, is intravenously injected into mice followed by an intravenous injection of gram-negative lipopolysaccharide (LPS) 7 days later, most of the mice die of massive hepatic cell necrosis within 24 hours of LPS injection. Using this experimental model, acute hepatic failure was induced in mice, and the tryptophan metabolism in the liver, brain and kidney was studied. As a result, the tryptophan level was remarkably high in all three organs, and the metabolism of both the tryptamine pathway and serotonin pathway was induced. However, in the brain, the tryptamine metabolism was more induced compared to the serotonin, suggesting that the metabolites of tryptamine, may be involved in hepatic encephalopathy.  相似文献   
5.
6.
The serum triglyceride concentration (TG) tested in health checks after meals cannot properly sort out hypertriglyceridemia with reference to the upper normal limit of fasting TG (150 mg/dl) set by the Japan Arteriosclerosis Society, because TG goes up considerably after a meal. In our survey of a large number of health check examinees (free of abnormal biochemical data other than TG and diseases under medical treatment), the mean (M) of fasting TG + 2 standard deviations (SD) was close to 150 mg/dl. When the screening level was set at M + 2SD for each time span after a meal, the ratio of the screened was distributed between 19.9 and 21.8%, which was close to 23.5%, the ratio of the screened on fasting. Accordingly, the nearest round number ending with zero for the first digit is suggested to be of practical use for the screening level of after-meal TG. The average TG in females was definitely lower than that of males, though proportionately increasing with age. The ratio of the screened among females aged between 20 and 49 was 5.3% on fasting and 3.2-5.8% for after-meal time spans, and that of the screened aged in their fifties was 11.3% and 8.2-12.9% respectively.  相似文献   
7.
8.
9.
Bacteroides forsythus is a recently recognized human periodontopathogen associated with advanced, as well as recurrent, periodontitis. However, very little is known about the mechanism of pathogenesis of this organism. The present study was undertaken to identify the surface molecules of this bacterium that may play roles in its adherence to oral tissues or triggering of a host immune response(s). The gene (bspA) encoding a cell surface-associated protein of B. forsythus with an apparent molecular mass of 98 kDa was isolated by immunoscreening of a B. forsythus gene library constructed in a lambda ZAP II vector. The encoded 98-kDa protein (BspA) contains 14 complete repeats of 23 amino acid residues that show partial homology to leucine-rich repeat motifs. A recombinant protein containing the repeat region was expressed in Escherichia coli, purified, and utilized for antibody production, as well as in vitro binding studies. The purified recombinant protein bound strongly to fibronectin and fibrinogen in a dose-dependent manner and further inhibited the binding of B. forsythus cells to these extracellular matrix (ECM) components. In addition, adult patients with B. forsythus-associated periodontitis expressed specific antibodies against the BspA protein. We report here the cloning and expression of an immunogenic cell surface-associated protein (BspA) of B. forsythus and speculate that it mediates the binding of bacteria to ECM components and clotting factors (fibronectin and fibrinogen, respectively), which may be important in the colonization of the oral cavity by this bacterium and is also a target for the host immune response.  相似文献   
10.
Ellsberg's two-color problem, known as an example of ambiguity aversion, has generated a great deal of interest among many researchers. However, an unsettled question remains regarding the conditions that lead to heightened or diminished ambiguity aversion. We conducted a series of experiments, which required participants to choose between a clear and vague bet. Results showed that participants did not always prefer the clear bet, and the ratios of those who indicated ambiguity aversion varied depending on the types of ambiguity. Furthermore, ambiguity aversion consistently decreased when participants were allowed to choose the ambiguity task they would perform. These results were interpreted in terms of the pattern of second order probability distributions and illusion of control.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号