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   743篇
  免费   49篇
  国内免费   7篇
耳鼻咽喉   2篇
儿科学   14篇
妇产科学   2篇
基础医学   169篇
口腔科学   36篇
临床医学   102篇
内科学   124篇
皮肤病学   29篇
神经病学   100篇
特种医学   8篇
外科学   44篇
综合类   1篇
预防医学   37篇
眼科学   12篇
药学   75篇
中国医学   4篇
肿瘤学   40篇
  2023年   2篇
  2022年   7篇
  2021年   6篇
  2020年   9篇
  2019年   19篇
  2018年   10篇
  2017年   11篇
  2016年   15篇
  2015年   14篇
  2014年   17篇
  2013年   34篇
  2012年   44篇
  2011年   55篇
  2010年   39篇
  2009年   31篇
  2008年   51篇
  2007年   57篇
  2006年   55篇
  2005年   54篇
  2004年   71篇
  2003年   34篇
  2002年   47篇
  2001年   16篇
  2000年   11篇
  1999年   10篇
  1998年   14篇
  1997年   7篇
  1996年   10篇
  1995年   3篇
  1994年   4篇
  1993年   6篇
  1992年   2篇
  1991年   4篇
  1990年   5篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1982年   3篇
  1981年   2篇
  1977年   1篇
  1974年   2篇
  1972年   1篇
  1971年   1篇
  1969年   3篇
  1966年   2篇
排序方式: 共有799条查询结果,搜索用时 203 毫秒
721.
A prospective study was carried out on a large cohort of males undergoing radical retropubic prostatectomy in order to identify genetic marker regions significantly associated with tumor formation. By comprehensive allotyping of chromosomes known to be associated with prostate carcinogenesis, an algorithm could be formulated for the genetic pathway and a method of discrimination between aggressive and less aggressive forms could be identified.  相似文献   
722.
723.
724.
725.
726.
Carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1) is usually expressed at the luminal surface of different epithelia and is up-regulated in endothelial cells during angiogenesis. Here, we demonstrate evidence of morphogenetic effects of CEACAM1 in spermatogenesis. CEACAM1 is detectable in normal testicular tissue and seminal fluid. It is present in the adluminal part of Sertoli cells extending only as far as the tight junctions between them. CEACAM1 immunostaining is significantly increased and extends to the basal part of Sertoli cells in the presence of carcinoma in situ. Also, in vitro-induced spermatogenetic disturbance leads to an enhanced CEACAM1 expression in Sertoli cells after 3 days of culture. Remarkably, seminiferous tubules containing exclusively Sertoli cells do not exhibit any CEACAM1 expression. CEACAM1 staining was absent in vascular endothelial cells of normal testicular tissue, but present in small blood vessels of seminomas. These data suggest that CEACAM1 expression in Sertoli cells depends on the presence of germ cells and plays a role in adhesive interactions between Sertoli and differentiating germ cells. Its up-regulation in Sertoli cells accompanying spermatogenic damage may contribute to reconstruction and maintenance of the tubular structure of seminiferous tubules. Additionally, CEACAM1 is apparently involved in the angiogenesis of germ cell tumours.  相似文献   
727.
The response to cholecystokinin (CCK) as a satiety peptide in obesity or anorexia has been tested mainly in extreme models of food intake control. In the present study, the effect of CCK-8S on food intake was investigated in a nongenetic and less-stressful model of obesity due to unspecific early postnatal overfeeding in male and female rats. Reducing the normal litter size of ten to three newborn rats on day 3 of life led to an enhanced food intake resulting in an increased body weight until adulthood. Freely fed male and female, normal and obese rats were given 10 g/kg CCK-8S i.p. on day 41 and 40 g/kg CCK-8S on day 91 of life and food intake was measured for 24 h. Compared with treatment with saline (i.p.) 1 day before the test, the lower dose of 10 g/kg CCK-8S reduced food intake for 2 h in normal, but not in obese rats. Conversely, the higher dose of 40 g/kg CCK-8S reduced food intake in both normal and obese rats for 2 h, but this effect was more evident in the obese rats. Moreover, the satiating effect of CCK-8S was more pronounced and longer lasting in male than in female rats. In summary, the data suggest that the response to CCK-8S differs in normal and obese rats and depends on sex.  相似文献   
728.
PURPOSE: At diagnosis, the biological behavior of prostate cancer is uncertain, making the choice of an adequate therapy option difficult. Performing microsatellite allelotyping on a large series of consecutive prostate cancers procured during radical prostatectomy at our institution, we sought to identify molecular markers associated with disease progression. EXPERIMENTAL DESIGN: A total of 156 consecutive fresh tumor samples was prospectively collected and macroscopically dissected from the whole prostatectomy specimen immediately after operation. Histologically 100 samples contained >75% tumor cells and were therefore enrolled in the microsatellite allelotyping, using a total of 24 polymorphic markers for the chromosomal regions 5p, 5q, 7q, 8p, 9p, 9q, 13q, 17p, 17q, and 18q. Fresh paired normal and tumor DNA was investigated in fluorescent microsatellite analysis with automated laser product detection. RESULTS: The incidence of tumor-DNA alterations [loss of heterozygosity or allelic imbalance (AI)] was highest for chromosomal regions 13q and 8p with 72 and 71%, respectively, followed by chromosomes 7q, 18q, 5q, and 17p with 57, 53, 41, and 39%, respectively. Alterations at chromosomes 8p, 9p, 13q, and 17p were significantly (P < 0.05) associated with advanced tumor stage, whereas AI at 8p and 17p was also associated with high Gleason score (P < 0.05). AI at 5q and 9p was associated with regional lymph node metastasis (P < 0.05). The combination of AI at 8p and 13q was strongly associated with advanced tumor stage (P < 0.0001). CONCLUSIONS: With the obtained results, we are able to postulate three distinct pathways in prostate carcinogenesis, and we identified microsatellite markers of prognostic value.  相似文献   
729.
A series of 74 consecutive patients (48 women, 26 men) were operated for abdominal hydatid disease between June 1949 and December 1995. The patients ranged in age from 15 to 81 years (median 49 years). In 69 cases only the liver was affected; two patients had concomitant extrahepatic disease (one spleen, one spleen and lung), and 3 had cysts in the spleen only. Cysts were multiple in 11 patients and calcified in 24. Conservative surgical procedures were used for 22 cysts in 20 patients [open partial (n= 3), open total (n= 6), closed total cystectomy (n= 9), marsupialization (n= 2), drainage (n= 2)] and radical surgical procedures for 72 cysts in 54 patients [pericystectomy (n= 41), wedge liver resection or hemihepatectomy (n= 25), splenectomy (n= 5), radical resection of a lung cyst (n= 1)]. Altogether 37 patients (50%) were given perioperative antihelmintic chemotherapy with mebendazole (18 patients) or albendazole (19 patients). Operative mortality rates were 5.0% after conservative surgery and 1.8% after radical surgery. Morbidity rates were 25.0% following conservative surgery and 24.1% following radical surgery. Antihelmintic therapy was well tolerated by all but five patients. All side effects were entirely reversible. Among the 74 patients, 60 (81.0%) were available for long-term follow-up (median 7.2 years; range 2.0–47.0 years). Recurrence of disease was seen in 9 of 60 patients at an interval of 3 months to 20 years from the first operation. The rate of recurrence was significantly lower after radical surgical procedures (p= 0.03) and after closed removal of the cyst (p= 0.04).  相似文献   
730.
Dogs with spontaneous diseases can exhibit a striking similarity in etiology, clinical manifestation, and disease course when compared to human patients. Therefore, dogs are intensely discussed as a translational model of human disease. In particular, genetic studies in selected dog breeds serve as an excellent tool to identify epilepsy disease genes. In addition, canine epilepsy is discussed as a translational platform for drug testing. On one hand, epileptic dogs might serve as an interesting model by allowing the evaluation of drug efficacy and potency under clinical conditions with a focus on chronic seizures resistant to standard medication, preventive strategies, or status epilepticus. On the other hand, several limitations need to be considered including owner‐based seizure monitoring, species differences in pharmacokinetics and drug interactions, as well as cost‐intensiveness. The review gives an overview on the current state of knowledge regarding the etiology, clinical manifestation, pathology, and drug response of canine epilepsy, also pointing out the urgent need for further research on specific aspects. Moreover, the putative advantages, the disadvantages, and limitations of antiepileptic drug testing in canine epilepsy are critically discussed.  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