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   6103篇
  免费   316篇
  国内免费   55篇
耳鼻咽喉   36篇
儿科学   110篇
妇产科学   107篇
基础医学   686篇
口腔科学   180篇
临床医学   489篇
内科学   1548篇
皮肤病学   165篇
神经病学   687篇
特种医学   217篇
外科学   991篇
综合类   29篇
预防医学   166篇
眼科学   68篇
药学   380篇
中国医学   27篇
肿瘤学   588篇
  2023年   45篇
  2022年   103篇
  2021年   183篇
  2020年   121篇
  2019年   110篇
  2018年   163篇
  2017年   133篇
  2016年   156篇
  2015年   156篇
  2014年   244篇
  2013年   291篇
  2012年   390篇
  2011年   404篇
  2010年   240篇
  2009年   196篇
  2008年   350篇
  2007年   335篇
  2006年   285篇
  2005年   322篇
  2004年   288篇
  2003年   306篇
  2002年   260篇
  2001年   141篇
  2000年   110篇
  1999年   117篇
  1998年   52篇
  1997年   45篇
  1996年   37篇
  1995年   32篇
  1994年   15篇
  1993年   18篇
  1992年   76篇
  1991年   59篇
  1990年   73篇
  1989年   76篇
  1988年   60篇
  1987年   49篇
  1986年   36篇
  1985年   55篇
  1984年   38篇
  1983年   30篇
  1981年   14篇
  1980年   17篇
  1979年   29篇
  1978年   25篇
  1977年   16篇
  1974年   22篇
  1973年   15篇
  1970年   20篇
  1967年   13篇
排序方式: 共有6474条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Ocotea quixos essential oil was shown to possess significant inhibitory activity of platelet aggregation and clot retraction in rodent plasma. This study is aimed at fully characterizing the antiplatelet activity of the whole essential oil and its main components trans-cinnamaldehyde and methyl cinnamate also in human plasma, at investigating the mechanism underlying such activity and at evaluating the potential antithrombotic activity of subacute treatment of mice with Ocotea essential oil. In vitro Ocotea essential oil and trans-cinnamaldehyde inhibited arachidonic acid-, U46619-, ADP-, phorbol12-myristate13-alcetate-, collagen-induced platelet aggregation and thrombin-induced clot retraction in human and rodent plasma; Ocotea oil and trans-cinnamaldehyde competitively antagonized contractions induced by thromboxane A2 receptor agonist U46619 in rat isolated aortic ring (K(B) = 18 and 3.2 microg ml(-1), respectively). In vivo Ocotea oil, orally administered in a subacute treatment (30-100 mg kg(-1) day(-1) for 5 days) to mice, prevented acute thrombosis induced by collagen-epinephrine intravenous injection. This antithrombotic activity was not accompanied by pro-haemorragic side effect, as detected by the inactivity in bleeding test, thus showing a favourable safety profile compared to the conventional antiplatelet agent, acetylsalicylic acid. Present findings indicate that Ocotea essential oil possesses potent and safe antithrombotic activity attributable to its antiplatelet and vasorelaxant effects. The main constituent trans-cinnamaldehyde seems to be the primary responsible for this activity through a putative mechanism involving the inhibition of thromboxane A2 receptors.  相似文献   
5.
T Terao  Y Tani 《Journal of UOEH》1988,10(3):337-340
We report two cases of severe withdrawal symptoms after abrupt discontinuation of a long-term normal-dose benzodiazepines (BZD) administration. Case 1, a 61-year-old man, suffered from delirium on the 7th day after abrupt discontinuation of nitrazepam, 10 mg/day. Case 2, a 49-year-old woman, suffered from auditory hallucination on the 4th day and visual cognitive disorder on the 5th day after abrupt discontinuation of nitrazepam, 5 mg/day, and triazolam, 0.5 mg/day. A withdrawal syndrome after discontinuation of normal-dose BZD is uncommon, and a psychotic withdrawal reaction is even more uncommon. We show how a continuous administration of BZD for a period of longer than 6 months and the presence of severe insomnia are risk factors predictive of a psychotic reaction. We also explain the predictive method used to determine the onset time of such a severe state. In the case of a psychotic state, we recommend intravenous diazepam injection. To prevent withdrawal reaction, we also recommend a gradual reduction after administration of normal-dose BZD.  相似文献   
6.
KM2210, a conjugate of estradiol and chlorambucil (CBL), which was originally developed as an anti-breast cancer agent, inhibits proliferative response of human mononuclear cells to alloantigens in mixed lymphocyte culture in a dose-dependent manner, but has no effect on their response to phytohemagglutinin. Neither estradiol benzoate nor CBL alone showed these unique actions. The suppressive effect of KM2210 on MLC was abrogated by adding of anti-transforming growth factor-beta (TGF-beta) antibody to the culture, but was not affected by the addition of interleukin-2, suggesting that KM2210, unlike CBL, displays its actions via TGF-beta. In experimental allogeneic bone marrow transplantation using mice, daily oral administration of KM2210 (2 mg/kg/day) for 30 days posttransplant significantly inhibited the alloantigen-specific immune reactions. Furthermore, the survival rate of the KM2210-treated mice was significantly higher than that of the cyclosporine-treated (2 mg/kg/day, p.o.) mice, and no adverse effect of KM2210 on hematopoietic recovery was found. These results strongly suggest possible clinical benefits of KM2210 as a new immunosuppressive agent for the prevention and treatment of graft-versus-host disease and other allospecific immune reactions.  相似文献   
7.
In order to find useful information for the establishment of new treatment method to alcohol dependence, we investigated the change of the body image of patients with alcohol dependence before and after the treatment. HABIT (Haga Body Image Test), a questionnaire about body image developed in department of psychiatry in Kyoto Prefectural University of Medicine, was used to examine the change of body image between pre- and post-3-month conventional treatment program in 46 patients with alcohol dependence hospitalized into special institutions for treatment of the disease in Kyoto. Patients with poor outcome of the treatment showed improvement of body image on visceral function, feeling of appetite and outward appearance, while patients with good outcome indicated no significant change in these aspects. This finding likely suggests that the treatment would result in good outcome in patients having stable feeling of physical health, and the cognitive treatment approach about these aspects of body image should be performed on the patients with poor treatment outcome. On the other hand, the body image about motor function showed significantly higher score in the patients approach for the patients with poor outcome to become aware of their physical activity would be effective.  相似文献   
8.
Experimental delayed cerebral vasospasm was produced in canine basilar arteries by 2 successive injections, 2 days apart, of fresh autogenous arterial blood into the cisterna magna. When angiographic evidence of delayed vasospasm was confirmed 7 days after the initial intracisternal blood injection, a selective inhibitor of 5-lipoxygenase, 2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benzoqu inone (AA-861), was infused intravenously at 6.5 X 10(-4) mg/kg/min for 2 hours. However, angiographic evidence of delayed vasospasm was not reversed, and mean regional cerebral blood flow was not significantly increased. In other studies, oral doses of AA-861 at 100 mg/kg/day were given twice a day for 7 days after the initial intracisternal blood injection. In the treated group, angiographic evidence of delayed vasospasm was significantly reduced, and the contractile property of excised basilar arteries in response to vasoconstrictor agents was significantly improved. It is suggested that leukotrienes, 5-lipoxygenase products of arachidonic acid, might be important etiologic factors responsible for the development of delayed vasospasm and that AA-861 would have a therapeutic effect not on the reduction of delayed vasospasm once developed but on the prevention of the development of delayed vasospasm.  相似文献   
9.
PURPOSE: To determine the independent relationship between leukoreduced platelet transfusions and adverse events in cardiac surgery. METHODS: In this observational study, detailed baseline and perioperative data were prospectively collected on consecutive patients who underwent cardiac surgery at a single institution from 1999 to 2004. The independent associations of platelet transfusion with clinical outcomes (low output syndrome, myocardial infarction, stroke, renal failure, sepsis, and death) were determined by multivariable logistic regression analysis and propensity score case-control analysis. RESULTS: Of the 11,459 patients analyzed, 2,174 (19%) received (leukoreduced) platelets - 1,408 received 5 U, 471 received 10 U, 140 received 15 U, and 155 received 20 or more units. Although all measured adverse event rates were higher in those who received platelets, in neither the logistic regression analyses nor the propensity score analyses was there any association between platelet transfusion and any of the adverse events. CONCLUSIONS: Transfusion of leukoreduced platelets in cardiac surgery is not associated with adverse clinical outcomes when adjustments are made for important confounders.  相似文献   
10.
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