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   46435篇
  免费   3194篇
  国内免费   89篇
耳鼻咽喉   416篇
儿科学   1123篇
妇产科学   1102篇
基础医学   6554篇
口腔科学   1114篇
临床医学   4421篇
内科学   9486篇
皮肤病学   1001篇
神经病学   4767篇
特种医学   1900篇
外科学   6666篇
综合类   189篇
一般理论   25篇
预防医学   3696篇
眼科学   822篇
药学   3175篇
中国医学   50篇
肿瘤学   3211篇
  2023年   485篇
  2022年   270篇
  2021年   712篇
  2020年   732篇
  2019年   845篇
  2018年   1393篇
  2017年   1343篇
  2016年   1391篇
  2015年   1244篇
  2014年   1346篇
  2013年   2335篇
  2012年   3311篇
  2011年   3488篇
  2010年   1658篇
  2009年   1216篇
  2008年   2992篇
  2007年   2993篇
  2006年   2813篇
  2005年   2610篇
  2004年   2362篇
  2003年   2224篇
  2002年   2193篇
  2001年   1270篇
  2000年   1400篇
  1999年   895篇
  1998年   332篇
  1997年   273篇
  1996年   195篇
  1995年   209篇
  1994年   195篇
  1993年   182篇
  1992年   272篇
  1991年   256篇
  1990年   255篇
  1989年   249篇
  1988年   257篇
  1987年   208篇
  1986年   208篇
  1985年   247篇
  1984年   236篇
  1983年   196篇
  1982年   149篇
  1981年   129篇
  1980年   116篇
  1979年   169篇
  1978年   123篇
  1977年   116篇
  1974年   99篇
  1973年   94篇
  1969年   94篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Follow-up of patients 1 year after deep dorsal vein resection gives evidence of an approximate 50-60% success rate. A careful selection of only this small percentage of patients, in whom abnormal drainage through the penile dorsum is obvious, is mandatory. Men with an arterial cofactor have to be excluded or to be subsequently treated by intracavernosal autoinjection of vasoactive substances. Late results from our study demonstrate a further loss of sufficient erection, also in men considered as persistent success by us, in the subjective view of the patient and/or his sexual partner.  相似文献   
52.
53.

Background  

Despite considerable knowledge about musculoskeletal disorders (MSD) and physical, psychosocial and individual risk factors there is limited knowledge about physical activity as a factor in preventing MSD. In addition, studies of physical activity are often limited to either leisure activity or physical activity at work. Studies among military personnel on the association between physical activity at work and at leisure and MSD are lacking. This study was conducted to find the prevalence of MSD among personnel in the Royal Norwegian Navy and to assess the association between physical activity at work and at leisure and MSD.  相似文献   
54.
Background From the endocrine surgeon’s perspective, it is important to know how endocrinologists manage patients with primary hyperparathyroidism (pHPT). The aim of this survey was to evaluate the preoperative diagnostic workup and referral pattern for parathyroidectomy by Swiss endocrinologists. Materials and methods The survey was conducted by mailing a questionnaire to all members of the Swiss Society for Endocrinology and Diabetes in spring 2005. Results The questionnaire was sent back by 68 of 124 endocrinologists (55%). The median annual case volume of patients with pHPT was 6 (range 1–50). The mean fraction of these patients referred for surgery was 59 ± 24%. This fraction was significantly higher in the German-speaking part of Switzerland than in the French-speaking part (67 ± 21% vs 51 ± 27%). When considering surgery for asymptomatic pHPT, 62% of the endocrinologists rely routinely on the recommendations of the NIH consensus conference and 86% on the subsequent guidelines of the workshop in 2002. Sixty-seven percent of the endocrinologists routinely perform localization studies before possible referral for surgical exploration. Typically, they consisted of an ultrasonography of the neck (93%) and a 99mTc-MIBI scintigraphy (80%). The impact of the availability of a minimally invasive surgical procedure on the number of patients referred for surgery seems to be considerable. Sixty-one percent of the participants would expand the indication for surgery if the operation could be done by a limited surgical approach. Conclusions In a relevant fraction of patients with pHPT, endocrinologists still do not regard curative therapy as mandatory. Surprisingly, there are significant cultural differences concerning referral patterns to surgery between the German-speaking and the French-speaking parts of Switzerland. Minimally invasive procedures seem to lower the threshold for referral for surgical therapy. This work was presented at the 2nd Biennial Congress of the ESES, May 2006, Krakow, Poland.  相似文献   
55.
56.
The three-dimensional (3D) evaluation and comparison of free-form-surfaces is a complex problem [Dent. Mater. 8 (1992) 49; J. Dent. Res. 76 (1997) 1799; Dent. Mater. 16 (2000) 145; J. Prosthet. Dent. 70 (1993) 457; Dent. Mater. 19 (2003) 19]. However, it is essential in order to analyze the sinter shrinkage of dental ceramic-restorations where isotropic and linear shrinkage is desired for accurate fit on the prepared teeth. In this article, we examine the 3D sinter shrinkage in general and for nine copings from alumina in particular. Using various scaled CAD-models in an iteration scheme, each model was compared to the filtered point cloud of the coping, determining the surface-cloud difference. The magnitude of deviations from linear sinter shrinkage was investigated. Furthermore, a new fabrication process for ceramic-restorations is introduced.  相似文献   
57.
58.
Gonadal function was evaluated in 25 boys treated for Hodgkin's disease according to the DAL-HD-85 protocol with OPA- or OPA/COMP-chemotherapy (vincristine-prednisone-adriamycine/cyclophosphamide-vincristine-m ethotrexate- prednisone). All boys were in first continuous complete remission for 6 to 45 months at chronological ages varying from 14.0 to 18.9 years. Testosterone, basal and GnRH-stimulated LH- and FSH-levels were measured. Gonadal function was normal in 16 patients treated with 2 cycles of OPA-chemotherapy in Hodgkin stages I-IIA. 9 patients were treated with 2 OPA- and 2 or 4 COMP-cycles of chemotherapy and had received mean cyclophosphamide doses ranging from 2004 to 3722 mg/m2. Again, no major testicular damage was noted, though some patients had increased stimulated LH-levels possibly indicating compensated Leydig cell-insufficiency. Our results demonstrate, that testicular function is not severely affected when patients are treated for Hodgkin's disease without procarbazine even if cyclophosphamide is given in cumulative doses below 3800 mg/m2. The previously documented severe testicular damage in boys treated according to the DAL-studies HD-78 and HD-82 is thus a result of the gonadotoxic action of procarbazine.  相似文献   
59.
The influence of the intensity of the conditioning stimulus on intracortical inhibition (ICI) and intracortical facilitation (ICF) was assessed in a study using paired-pulse transcranial magnetic stimulation. Interstimulus intervals (ISIs) between conditioning and test stimuli were 3 msec and 13 msec. Latencies and areas of motor evoked potentials in response to the test stimulus were measured in the right extensor carpi radialis muscle. Motor evoked potential areas with ISIs of 3 msec and 13 msec showed a different dependence on the intensity of the conditioning stimulus. In contrast, the changes of motor evoked potential latencies were fairly similar with both ISIs. The findings point to a parallel action of ICI and ICF. Furthermore, the latencies seem to be a more sensitive indicator for ICF action than the size parameters of motor evoked potentials.  相似文献   
60.
The rate of clearance from the lungs of inhaled technetium-99m labelled diethylene triamine penta-acetic acid (99mTc-DTPA) is often increased in interstitial lung disease as well as in smoking. In smokers a bi-exponential clearance course of 99mTc-DTPA when measured over 3 h has previously been shown. This study was performed to compare the kinetics of clearance of 99mTc-DTPA, measured for 3 h, in sarcoid patients and healthy smokers. Forty-one never-smoking patients with sarcoidosis and radiological signs of intrathoracic disease were studied. The results were compared with those of 16 healthy current smokers and of 14 healthy never-smokers reported previously. A mono-exponential clearance equation described the clearance in 22 of the sarcoid patients and all normal never-smokers, but with a shorter average tracer half-life in the patients (P<0.05). In 19 patients and all smokers a bi-exponential equation gave a significantly better curve fit. The rate of clearance of the slow component was higher in patients with sarcoidosis than in smokers (P< 0.05). The fraction of the tracer cleared by the fast clearance component was smaller in patients with sarcoidosis than in smokers (P<0.01). Differences in kinetics of clearance of 99mTc-DTPA in sarcoidosis and smoking could thus be demonstrated, suggesting that the abnormal clearance is caused by diverging pathophysiological mechanisms.  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