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   2574篇
  免费   135篇
  国内免费   26篇
耳鼻咽喉   18篇
儿科学   52篇
妇产科学   53篇
基础医学   368篇
口腔科学   84篇
临床医学   140篇
内科学   565篇
皮肤病学   28篇
神经病学   249篇
特种医学   114篇
外科学   325篇
综合类   17篇
预防医学   79篇
眼科学   33篇
药学   218篇
中国医学   6篇
肿瘤学   386篇
  2023年   27篇
  2022年   29篇
  2021年   59篇
  2020年   33篇
  2019年   43篇
  2018年   73篇
  2017年   54篇
  2016年   49篇
  2015年   72篇
  2014年   80篇
  2013年   88篇
  2012年   182篇
  2011年   154篇
  2010年   75篇
  2009年   73篇
  2008年   127篇
  2007年   148篇
  2006年   124篇
  2005年   145篇
  2004年   122篇
  2003年   141篇
  2002年   122篇
  2001年   48篇
  2000年   50篇
  1999年   62篇
  1998年   31篇
  1997年   19篇
  1996年   15篇
  1995年   16篇
  1994年   14篇
  1993年   16篇
  1992年   50篇
  1991年   49篇
  1990年   39篇
  1989年   34篇
  1988年   40篇
  1987年   25篇
  1986年   20篇
  1985年   27篇
  1984年   22篇
  1983年   17篇
  1982年   11篇
  1981年   11篇
  1980年   8篇
  1979年   14篇
  1978年   20篇
  1977年   10篇
  1974年   7篇
  1971年   7篇
  1968年   5篇
排序方式: 共有2735条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
We studied subsets and cytotoxicity of recombinant interleukin-2 (rIL-2) expanded tumor infiltrating lymphocytes (TIL) from renal cell cancer (RCC) patients. TIL were successfully expanded in 13 of 14 RCC cases using anti-CD3 during initial 48 hours of culture. Percentages of CD8 positive cells among rIL-2 expanded TIL at 1 tp 4 week(s) of culture were 56.2 +/- 15.1% (range 26.2 to 79.8%, N = 13) and not necessarily predominant over CD4 positive cells. NK and LAK activities of TIL at 3 to 6 weeks of culture were 31.6 +/- 15.8% (range 1.4 to 57.4%, N = 9) and 16.6 +/- 11.6% (range 3.8 to 35.6%, N = 6), respectively. Autologous and allogeneic RCC cytotoxicity of TIL at 3 to 4 weeks of culture were 17.9 +/- 19.7% (range 0 to 47.6%, N = 4) and 18.9 +/- 14.8% (range 0 to 47.3%, N = 12), respectively. Since there was no statistical difference between them, autologous specific cytotoxicity was not demonstrated. From these results of present study, it is unlikely that most of effector cells of rIL-2 expanded TIL in autologous RCC lysis are major histocompatibility complex restricted cytotoxic T cells. And we concluded that it is doubtful that TIL is significantly superior over LAK cells in immunotherapy of human RCC.  相似文献   
5.
Mechanical stimulation is known to be an essential factor in the regulation of cartilage metabolism. We tested the hypothesis that expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) can be modulated by cyclic tensile stretch load in chondrocytes. Cyclic loading of repeated stretch stress at 10 cycles per minute with 10 kPa of stress for 6 h induced expression of LOX-1 to 2.6 times control in cultured bovine articular chondrocytes, equivalent to the addition of 10 microg/mL oxidized low density lipoprotein (ox-LDL) (2.4 times control). Application of the cyclic load to the chondrocytes along with 10 microg/mL ox-LDL resulted in synergistically increased LOX-1 expression to 6.3 times control. Individual application of cyclic loading and 10 microg/mL ox-LDL significantly suppressed chondrocytes viability (84.6% +/- 3.4% and 80.9% +/- 3.2% of control at 24 h, respectively; n = 3; p < 0.05) and proteoglycan synthesis [81.0% +/- 7.1% and 85.7% +/- 5.2% of control at 24 h, respectively; p < 0.05 when compared with 94.6% +/- 4.6% for native-LDL (n = 3)]. Cyclic loading and 10 microg/mL ox-LDL synergistically affected cell viability and proteoglycan synthesis, which were significantly suppressed to 45.6% +/- 4.9% and 48.7% +/- 6.7% of control at 24 h, respectively (n = 3; p < 0.01 when compared with individual application of cyclic loading or 10 microg/mL ox-LDL). In this study, we demonstrated synergistic effects of cyclic tensile stretch load and ox-LDL on cell viability and proteoglycan synthesis in chondrocytes, which may be mediated through enhanced expression of LOX-1 and which has important implications in the progression of cartilage degeneration in osteoarthritis.  相似文献   
6.
A 48-year-old woman was admitted because of increased bloody sputum. Since she had had a history of repeated thrombotic episodes including venous thrombosis in the lower limbs (21 year old) and pulmonary emboli developing into pulmonary infarction (41 years old), the patient was treated with anti-coagulant therapy using Warfarin for 7 years. Warfarin was discontinued after admission and heparin was administered instead at a relatively low dose of 5,000 units daily, resulting in a considerable diminution of hemoptysis. Unfortunately however, it caused a relapse of active thrombosis associated not only with a significant increase of the product of fibrinolysis (FDP), LDH and GOT but with a concomitant decrease of the platelet count. Hematological examinations concerning coagulation and fibrinolysis remained within a normal range except for the serum concentration of antithrombin III (AT III) and its functional property with regard to the heparin cofactor, which were 8.8 mg/dl and 48%, respectively. Since the findings were consistent with congenital deficiency of AT III, some members of her family were also examined. The concentration of AT III and its activity in the patient's son and her daughter deteriorated in a similar manner, indicating that this was a definite case of congenital deficiency of AT III. The clinical manifestations of 87 cases with congenital AT III deficiency, belonging to 24 families reported in Japan were reviewed.  相似文献   
7.
To examine species differences in the distribution pattern of guanosine triphosphate (GTP)-binding protein (Go) within the vertebrate retina, paraffin-embedded retinae from a number of vertebrate species, including the goldfish, frog, turtle, chicken, monkey, and human, were immunohistochemically stained with affinity-purified antibody against the alpha-subunit of Go. Go-immunoreactive products were found to be located in the neuropil, but not in the cell bodies of neurons, in the retina of all these species. However, some species differences were observed. In the frog, monkey and human, the inner plexiform layer (IPL) was homogeneously stained with this antibody, but in the goldfish, turtle and chicken, the IPL was heterogeneously stained. In the frog, chicken, turtle and human, the outer plexiform layer (OPL) was densely stained with this antibody, but in the goldfish and monkey, the OPL was rather faintly immunoreactive to the antibody. In the goldfish, monkey and human, the outer nuclear layer (ONL) was not immunoreactive to the Go-antibody, whereas in the frog, turtle and chicken, the ONL was immunoreactive to it. The implications of these species differences in Go localization in the vertebrate retina are discussed.  相似文献   
8.
9.
10.
We report the case of a 67-year-old woman with severe hypertension caused by an extra-adrenal pheochromocytoma. The tumor was detected by 131I metaiodobenzylguanidine scintigraphy and it was found to be small (2 cm ?) by enhanced CT. After the extirpation of the tumor, the blood pressure of the patient immediately normalized. It should be taken into account that a small extra-adrenal pheochromocytoma can be one of the causes of secondary hypertension in elderly patients. Since small extra-adrenal pheochromocytomas are difficult to detect, it is also important to perform suitable examinations to establish the diagnosis. Furthermore, we emphasize the importance of an accurate diagnosis in elderly patients with pheochromocytoma, for they often have less symptomatology and more severe cardiovascular complications due to refractory hypertension than younger patients.  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