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   39012篇
  免费   1872篇
  国内免费   176篇
耳鼻咽喉   485篇
儿科学   741篇
妇产科学   666篇
基础医学   5313篇
口腔科学   1341篇
临床医学   2866篇
内科学   9536篇
皮肤病学   904篇
神经病学   2822篇
特种医学   1526篇
外科学   6326篇
综合类   240篇
一般理论   2篇
预防医学   1177篇
眼科学   571篇
药学   2610篇
中国医学   68篇
肿瘤学   3866篇
  2022年   314篇
  2021年   698篇
  2020年   351篇
  2019年   519篇
  2018年   684篇
  2017年   515篇
  2016年   587篇
  2015年   659篇
  2014年   909篇
  2013年   1067篇
  2012年   1708篇
  2011年   1848篇
  2010年   1007篇
  2009年   924篇
  2008年   1680篇
  2007年   1800篇
  2006年   1878篇
  2005年   1907篇
  2004年   1809篇
  2003年   1727篇
  2002年   1723篇
  2001年   1291篇
  2000年   1444篇
  1999年   1277篇
  1998年   537篇
  1997年   384篇
  1996年   389篇
  1995年   341篇
  1994年   299篇
  1993年   295篇
  1992年   846篇
  1991年   808篇
  1990年   722篇
  1989年   741篇
  1988年   710篇
  1987年   697篇
  1986年   692篇
  1985年   620篇
  1984年   453篇
  1983年   368篇
  1979年   354篇
  1978年   249篇
  1977年   210篇
  1975年   216篇
  1974年   238篇
  1973年   223篇
  1972年   208篇
  1971年   217篇
  1970年   208篇
  1969年   234篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
Finasteride is standard medical treatment for androgenetic alopecia; however, no large studies with 5 years or more of follow up have been performed in Japan. The authors followed Japanese men with androgenetic alopecia treated with finasteride for 5 years to evaluate long‐term treatment efficacy. Of 903 men treated with finasteride (1 mg/day), 801 patients were evaluated over 5 years by modified global photographic assessment. Although the proportion of improvement was high (99.4%), modified global photographic assessment scores after 5 years of treatment were lower in patients with more advanced disease as measured by the modified Norwood–Hamilton scale. After separating patients into “sufficient” and “insufficient” efficacy groups according to the modified global photographic assessment score after 5 years (scores ≥6 and <6, respectively), multivariate analysis showed that independent risk factors of insufficient efficacy were age at start of treatment of 40 years or more (P = 0.021) and classification on the modified Norwood–Hamilton scale (P < 0.001), whereas presence of stress at start of treatment was a negative predictor (P = 0.025). In conclusion, continuous finasteride treatment for 5 years improved androgenetic alopecia with sustained effect among Japanese. Younger age and less advanced disease at start of treatment were the key predictors of higher finasteride efficacy.  相似文献   
3.
4.
Eosinophilic dermatosis of hematological malignancy is a paraneoplastic skin eruption associated with chronic lymphocytic leukemia and other B‐cell malignancies. It clinically resembles an insect bite reaction and it can precede the symptoms of the hematological malignancy or be related to a more aggressive course. Different treatments have been proposed, but partial response and recurrence are frequent. Herein, we describe a case of eosinophilic dermatosis associated with mantle cell lymphoma with remission after lenalidomide therapy.  相似文献   
5.
6.
One diagnostic criterion for metabolic syndrome is obesity from the accumulation of visceral fat; others include abdominal circumference and area of visceral fat as measured by computed tomography (CT) at the umbilical level. We evaluated visceral fat using frequency-selective excitation magnetic resonance (MR) imaging SPAIR (spectral attenuation with inversion recovery) water suppression THRIVE (3D T1-high resolution isotropic volume examination). Fifty of 70 slices with 2-mm interval were used to render and measure volume of visceral fat ranging within 10 cm of the umbilicus; the area of visceral fat at the umbilical level was also measured. Imaging was completed using breath hold within 14 s. Image processing was easier than using CT.  相似文献   
7.
8.
We report a case of biliary cystadenocarcinoma which recurred 41 months postoperatively. A 60-year-old woman was admitted for further examination of multiple metastatic tumors and a large amount of ascites. Systemic administration of 5FU and CDDP caused her CEA level to decrease gradually and abdominal computed tomography revealed considerable reduction of the metastatic tumors and ascites. Since her general condition had improved, chemotherapy was continued in the outpatient clinic.  相似文献   
9.
The involvement of oxidative stress in polymorphonuclear leukocytes (PMN) in the pathogenesis of hypertension remains to be elucidated. We analyzed the generation of reactive oxygen species (ROS) by the circulating and peritoneally infiltrating PMN from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Flow cytometric analysis revealed that ROS generation by PMN from SHR was higher than that from WKY before (at 6 weeks of age) and after (at 16 weeks of age) the onset of hypertension. In vivo, ROS generation by PMN from SHR, but not that by PMN from WKY, was significantly suppressed by 10-week treatment with 50 mg/kg/day carvedilol, and this treatment did not affect blood pressure. Western blotting analysis revealed that protein kinase C alpha (PKCalpha), but not PKCbetaI or betaII, was activated more strongly in PMN from SHR than in PMN from WKY. Furthermore, expression of p47phox of nicotinamide adenine dinucleotide phosphate oxidase, but not of p67phox, in PMN from SHR was higher than that in PMN from WKY. These results suggest that ROS generation by PMN is principally enhanced in SHR through activation of PKCalpha and p47phox.  相似文献   
10.
Background and Aims:  The aim of this study was to determine which mouse strains exhibit tolerance to cooling when fertilized oocytes have been stored at 4°C.
Methods:  In-vitro -fertilization-derived oocytes of eight mouse strains were incubated at 4°C in 20 mmol/L Hepes-potassium modified simplex optimized medium (KSOM) medium for 0, 24, 48, 60 or 72 h, and then returned to normal culture conditions at 37°C in KSOM medium. The rates of development of cultured oocytes into blastocysts and cell numbers of blastocysts were examined. In some cases, a Comet assay was carried out to evaluate DNA damage. In addition, the effects of β-mercaptoethanol on the development of the 4°C-treated oocytes were assessed.
Results:  Of the eight strains tested, BDF1, B6C3F1 and FVB/N strains exhibited relatively higher degrees of tolerance to 4°C treatment and approximately 90%, 83% and 78% of oocytes treated at 4°C for 48 h developed to morphologically normal blastocysts, respectively. Comet assay revealed no clear DNA damage in oocytes treated at 4°C. Treatment with β-mercaptoethanol failed to improve the in vitro survival rate of low-temperature-treated oocytes.
Conclusion:  Strain differences were observed in tolerance to cooling treatment when fertilized oocytes were temporarily treated with 4°C, although the reasons for this remain unclear. (Reprod Med Biol 2006; 5 : 43–50)  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