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   1937篇
  免费   167篇
  国内免费   17篇
耳鼻咽喉   6篇
儿科学   67篇
妇产科学   24篇
基础医学   283篇
口腔科学   45篇
临床医学   145篇
内科学   417篇
皮肤病学   63篇
神经病学   155篇
特种医学   156篇
外科学   259篇
综合类   63篇
预防医学   91篇
眼科学   116篇
药学   86篇
中国医学   2篇
肿瘤学   143篇
  2021年   21篇
  2020年   23篇
  2019年   28篇
  2018年   27篇
  2017年   30篇
  2016年   31篇
  2015年   42篇
  2014年   47篇
  2013年   70篇
  2012年   71篇
  2011年   66篇
  2010年   78篇
  2009年   66篇
  2008年   73篇
  2007年   78篇
  2006年   62篇
  2005年   62篇
  2004年   64篇
  2003年   58篇
  2002年   59篇
  2001年   40篇
  2000年   49篇
  1999年   42篇
  1998年   56篇
  1997年   53篇
  1996年   47篇
  1995年   37篇
  1994年   41篇
  1993年   34篇
  1992年   51篇
  1991年   26篇
  1990年   22篇
  1989年   39篇
  1988年   41篇
  1987年   33篇
  1986年   37篇
  1985年   24篇
  1984年   27篇
  1983年   23篇
  1982年   26篇
  1981年   16篇
  1980年   22篇
  1979年   14篇
  1978年   14篇
  1977年   22篇
  1976年   15篇
  1975年   15篇
  1971年   10篇
  1970年   14篇
  1966年   11篇
排序方式: 共有2121条查询结果,搜索用时 31 毫秒
1.
Summary Deaza-aminopterin is a folate analog which is transported more rapidly than methotrexate into cells and appears to be more active than methotrexate against human and animal tumor in vitro. Fifteen patients with advanced urothelial tract cancer were given deaza-aminopterin 30–37.5 mg/m2 IV QW. In responding patients drug was given QOW after 4–6 consecutive doses. Doses were escalated or de-escalated by 7.5 mg/m2 depending on toxicity. Twelve patients had received prior chemotherapy which included methotrexate in nine. Three patients achieved a partial remission lasting 1, 3, and 3 months respectively: all responders had previously failed methotrexate after an initial response to a methotrexate containing regimen. None of the six patients who were methotrexate naive responded to deaza-aminopterin; 3 subsequently received methotrexate without response. Mild mucositis was universal and in 5 was severe. Six patients had an increase in liver transaminases probably secondary to anti-folate hepatotoxicity. Other toxicities included diarrhea, nausea, skin rash and fever. Further studies are needed to define the precise efficacy of deaza-aminopterin in patients with urothelial tract cancers.  相似文献   
2.
The scope of our research is the development of polymer-based bioabsorbable stents for urologic applications and in vitro testing of tissue reactions of cultured ureteral and urethral segments induced by implanted polymer stent prototypes. For these purposes a tissue cultivation model was developed using selected techniques of tissue engineering. Essential advantages of degradable over nondegradable urethral stents are elimination of the adverse extraction of epithelialized stents and the potential for recovery of organ-specific functionality. Moreover, the biocompatibility of a degradable urethral stent could potentially reduce the risk of restenosis due to hyperplasia and could be used, even repeatedly, for the treatment of a number of subvesical obstructions. For the treatment of tumor-induced strictures, application of degradable polymer stents coated with cytostatic drugs may be possible. The mechanical effect of the drug-loaded stent as a “place holder” could be complemented by adjuvant or palliative approaches such as local chemotherapy. We have developed and tested in vitro a degradable urethral stent incorporated with the model drug methotrexate for local drug delivery (LDD) by diffusion and during stent degradation.  相似文献   
3.
Summary Twenty-three patients with advanced renal cell cancer were treated with Didemnin B. One partial response was achieved (5%) in 21 evaluable patients. An allergic reaction was noted in four patients including one patient with anaphylaxis. Didemnin B is not recommended in the treatment of renal cell carcinoma.  相似文献   
4.
Demonstration of malignant cells in blood specimens collected during transurethral resection of the prostate (TURP) has implicated TURP in the dissemination of prostatic cancer. Of 153 patients who underwent radiation therapy for prostate cancer between January 1977 and June 1990 and were retrospectively analyzed, 93 were evaluable. Fifty-nine patients required TURP before radiation therapy for prostatic obstruction (BPH and/or cancer); the remaining 34 patients underwent radiation therapy after fine-needle aspiration biopsy. No statistically significant difference in failure rate could be detected between these groups, with a failure rate of 47% (28 of 59 patients) at a median follow-up time of 49 months (range, 8 to 146 months) in the TURP group versus a failure rate of 47% (16 of 34 patients) at a median follow-up time of 50 months (range, 3 to 122 months) in the group who underwent biopsy only (Fisher's exact test, P = 0.23). Within the confines of this retrospective study, it appeared that TURP did not enhance the development of metastatic disease.  相似文献   
5.
6.
Serosorting (i.e., engaging in unprotected sex with partners known to be of the same serostatus) can be a difficult process for men who have sex with men (MSM) who frequently make assumptions about their partners' serostatus. This process can be further complicated by a partner's dishonesty as well as other individual and contextual factors. The present study specifically examined how assumptions of serostatus made about unknown serostatus partners impact on the sexual behavior of 110 alcohol-abusing HIV-positive MSM. Although previous research has shown that HIV-positive MSM are more likely to serosort with other known HIV-positive men than with known HIV-negative men, our data suggest that unprotected sex behavior may not be specifically driven by whether or not they made assumptions of seroconcordance or serodiscordance. The types of assumptions these HIV-positive MSM made about their unknown status sexual partners and the basis for such assumptions were also examined. Owing to the ambiguities involved in assumptions of a partner's serostatus in sexual encounters, the 'unknown status' partner category is analytically distinct from 'known status' categories, and needs to be more fully explored because of its impact on perceived serosorting, rather than actual serosorting, among HIV-positive men.  相似文献   
7.
A case report of epithelioid adrenal angiosarcoma is presented. Tumor cells showed expression of cytokeratin, Factor VIII-related antigen, Ulex europaeus agglutinin-I, and vimentin. The patient also was found to have mesenteric fibromatosis (abdominal desmoid tumor) and an elevated serum level of estradiol. The authors discuss the unique appearance of these rare tumors, their relationship to hyperestrinism, and review the recent data in the literature showing cytokeratin expression by malignant epithelioid vascular tumors.  相似文献   
8.
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.  相似文献   
9.
10.
A patient who received one of the first homograft valves in Canada in 1965 is presented. Recent assessment including cardiac catheterization has shown that the valve is functioning well after 21 years. The patient is presented for historic interest, since this may be one of the longest functioning homograft valves.  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