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   17195篇
  免费   674篇
  国内免费   53篇
耳鼻咽喉   544篇
儿科学   1556篇
妇产科学   613篇
基础医学   1009篇
口腔科学   1039篇
临床医学   1208篇
内科学   3064篇
皮肤病学   441篇
神经病学   1013篇
特种医学   815篇
外科学   3763篇
综合类   338篇
一般理论   7篇
预防医学   521篇
眼科学   545篇
药学   875篇
中国医学   96篇
肿瘤学   475篇
  2024年   18篇
  2023年   186篇
  2022年   209篇
  2021年   360篇
  2020年   279篇
  2019年   325篇
  2018年   476篇
  2017年   408篇
  2016年   496篇
  2015年   442篇
  2014年   614篇
  2013年   854篇
  2012年   1025篇
  2011年   1046篇
  2010年   583篇
  2009年   423篇
  2008年   892篇
  2007年   1001篇
  2006年   1026篇
  2005年   1067篇
  2004年   1127篇
  2003年   1051篇
  2002年   1009篇
  2001年   685篇
  2000年   600篇
  1999年   512篇
  1998年   176篇
  1997年   141篇
  1996年   146篇
  1995年   65篇
  1994年   58篇
  1993年   33篇
  1992年   93篇
  1991年   84篇
  1990年   64篇
  1989年   63篇
  1988年   32篇
  1987年   29篇
  1986年   31篇
  1985年   28篇
  1984年   26篇
  1983年   13篇
  1981年   11篇
  1979年   11篇
  1978年   8篇
  1974年   8篇
  1972年   11篇
  1971年   8篇
  1967年   7篇
  1966年   10篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.  相似文献   
12.
13.
OBJECTIVE: The use of Kirschner wire for the fixation of premaxilla is a well-known method in bilateral cleft lip surgery. We report a case in which the Kirschner wire of the premaxillary fixation had migrated intrasphenoidally. RESULTS AND CONCLUSIONS: The foreign body was accidentally discovered during a cephalometric analysis and was taken out surgically through an upper lip sulcus incision. Although the wire remained asymptomatic for 10 years, it constituted a potential danger for intracranial migration.  相似文献   
14.
AIM: To evaluate the effects of oral continuous 17beta-estradiol plus norethisterone acetate (E2/NETA) replacement therapy on abdominal subcutaneous fat, serum leptin level (SLL) and body composition in postmenopausal women. MATERIALS AND METHODS: A 6-month, prospective, randomized, double-blind and placebo-controlled study was conducted. Forty-three healthy naturally postmenopausal women aged 43-65 years were randomly assigned to receive E2/NETA (2 mg E2 plus 1 mg NETA, n = 22) or placebo (n = 21). Fasting SLL by enzyme-linked immunosorbent assay, subcutaneous abdominal fat thickness (STh) by ultrasound and the anthropometric indices of body weight (BW), body mass index (BMI), waist and hip circumference (WC, HC) and waist-to-hip ratio (WHR) were recorded at the beginning and the end of the study. RESULTS: After 6 months of therapy, BW and SLL increased in the placebo group (p = 0.043 and 0.033, respectively). WC, HC and STh decreased significantly in the E2/NETA group (p = 0.002, 0.006 and 0.000, respectively) and they were also significantly lower in women receiving E2/NETA than in women taking placebo (p = 0.000, 0.034 and 0.000, respectively). At baseline, SLL and STh were positively correlated with all anthropometric indices except WHR. CONCLUSION: Oral continuous combined regimen of E2/NETA significantly reduced central fat accumulation as assessed by WC and STh, and attenuated the increase in SLL. The observed changes in SLL were highly and positively related to changes in STh. The oral continuous combined E2/NETA regimen appears to have protective effects on cardiovascular function and probably on metabolic diseases by its slimming effect upon WC in postmenopausal women.  相似文献   
15.
OBJECTIVE: Two visible light sources (tungsten-quartz-halogen and xenon-arc plasma) with vastly different intensities (200 and 1800 mW/cm(2)) but similar spectral outputs, were used to examine the effects of light intensity on conversion and flexural strength of a model dental resin formulation (75/25wt% bis-GMA/TEGDMA). METHODS: The exact same polymer samples were used to correlate double bond conversion (measured with near-IR spectroscopy) to flexural strength, both immediately after light exposure and after storage. RESULTS: In general, polymers which were irradiated with the high light intensity source exhibited greater double bond conversion. However, increasing the light intensity also increased the maximum temperature reached during polymerization. Therefore, the greater double bond conversion was caused by a combination of both photo and thermal effects. Regardless of the light intensity, a single linear relationship existed between conversion and final flexural strength (measured 4 days after cure) over the conversion range analyzed (50-80%). However, deviations from linearity were noted in several samples that were tested immediately after exposure. SIGNIFICANCE: These findings illustrate that light intensity does not affect the final flexural strength of a dental resin as long as the final conversions are similar.  相似文献   
16.
目的 探讨下肢深静脉瓣功能不全的二维及彩色多普勒超声声像图改变。方法 应用二维及彩色多普勒超声检查下肢深静脉瓣功能不全36例,47条腿,观察下肢静脉血管及瓣膜的解剖结构和血流动力学改变。结果 有静脉瓣功能不全的患肢静脉管腔内径均有不同程度增宽,瓣膜均有不同程度的改变,脉冲多普勒显示返流频谱返流时间大于0.5s。结论 该检查对诊断下肢深静脉瓣功能不全有较高的实用价值。  相似文献   
17.
Camptodactyly is a flexion deformity of the proximal interphalangeal joint. Because of unsatisfactory results, treatment is not recommended for mild deformities, and in severe deformities surgery has been disappointing. A specially designed external fixator providing gradual distraction was used in a severe case. With this mildly aggressive method, an acceptable result was obtained. Received: 5 June 1997/Accepted: 2 February 1998  相似文献   
18.
19.
The syndactyly repairs of 11 hands in seven patients (average age 20.4) who had simple complete syndactyly between the third and fourth fingers were done by the use of tissue expanders in order to obtain adequate skin closure. At the first stage, a wedge type, 7 cc tissue expander was placed beneath the dorsal skin of the syndactylous digits via a vertical dorsal hand incision under local anesthesia. Inflation was begun on the 15th postoperative day. After the inflation period (average 32 days), syndactyly repair similar to the Littler technique was performed using axillary block anesthesia. During the expansion period one tissue expander became exposed and this hand was repaired by the classical skin grafting technique. In the remaining ten hands the expanded dorsal skin ensured skin closure of the digits and web reconstruction without any need for skin grafting. No complications were encountered during the postoperative period. Active and passive abduction angles, tip-to-tip length, active range of motion of the digits, and two point discrimination tests were done at follow-up (average six months). The web appearances were normal in all patients. Active abduction angles and active range of motion of the digits was always normal at the third postoperative month. Two point discrimination was 8.7 mm on the interdigital sides of the digits and there was no tip-to-tip length differences of the digits. No contractures were seen.Presented at the International Congress of Surgery of the Hand and Upper Extremity, Izmir, Turkey, September 25, 1994.  相似文献   
20.
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