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   5285篇
  免费   257篇
  国内免费   104篇
耳鼻咽喉   33篇
儿科学   232篇
妇产科学   262篇
基础医学   859篇
口腔科学   86篇
临床医学   424篇
内科学   911篇
皮肤病学   50篇
神经病学   200篇
特种医学   424篇
外国民族医学   1篇
外科学   910篇
综合类   105篇
一般理论   1篇
预防医学   206篇
眼科学   46篇
药学   478篇
中国医学   2篇
肿瘤学   416篇
  2021年   54篇
  2019年   49篇
  2018年   64篇
  2017年   50篇
  2016年   66篇
  2015年   71篇
  2014年   97篇
  2013年   143篇
  2012年   232篇
  2011年   208篇
  2010年   175篇
  2009年   135篇
  2008年   264篇
  2007年   312篇
  2006年   276篇
  2005年   255篇
  2004年   198篇
  2003年   169篇
  2002年   180篇
  2001年   146篇
  2000年   151篇
  1999年   122篇
  1998年   74篇
  1997年   71篇
  1996年   74篇
  1995年   62篇
  1994年   62篇
  1993年   74篇
  1992年   77篇
  1991年   79篇
  1990年   102篇
  1989年   136篇
  1988年   104篇
  1987年   95篇
  1986年   93篇
  1985年   100篇
  1984年   54篇
  1983年   52篇
  1982年   36篇
  1981年   46篇
  1980年   44篇
  1979年   47篇
  1978年   39篇
  1977年   38篇
  1930年   28篇
  1929年   29篇
  1927年   30篇
  1926年   38篇
  1925年   31篇
  1924年   42篇
排序方式: 共有5646条查询结果,搜索用时 31 毫秒
1.
顺铂聚乳酸微球的药物释放特性及肝动脉栓塞研究   总被引:5,自引:0,他引:5  
对顺铂聚乳酸微球进行了体外药物释放和家犬肝动脉栓塞研究。该微球粒径范围为50~200μm,平均粒径为115.76±35.94μm,顺铂含量为37.16%(W/W);体外药物释放机制符合Higuchi方程;肝动脉栓塞后8h,肝组织顺铂浓度高达21.55±12.18μg/g,明显高于肝动脉灌注顺铂组:3.16±0.09μg/g(P<0.05);肝动脉栓塞组的顺铂血浓峰值、各取血点浓度及曲线下面积AUC皆低于肝动脉灌注顺铂组。可望达到提高栓塞部位的药物疗效,降低全身毒副反应的作用。  相似文献   
2.
Parfum de femme     
  相似文献   
3.
Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.  相似文献   
4.
Extravasation of chemotherapy is a feared complication of anticancer therapy. The accidental leakage of cytostatic agents into the perivascular tissues may have devastating short-term and long-term consequences for patients. In recent years, the increased focus on chemotherapy extravasation has led to the development of international guidelines that have proven useful tools in daily clinical practice. Moreover, the tissue destruction in one of the most dreaded types of extravasation (ie, anthracycline extravasation) now can effectively be prevented with a specific antidote, dexrazoxane.  相似文献   
5.
The multidrug efflux transporter P-glycoprotein (P-gp) is expressed in high concentrations at the blood-brain barrier (BBB) and is believed to be implicated in resistance to central nervous system drugs. We used small-animal PET and (R)-11C-verapamil together with tariquidar, a new-generation P-gp modulator, to study the functional activity of P-gp at the BBB of rats. To enable a comparison with human PET data, we performed kinetic modeling to estimate the rate constants of radiotracer transport across the rat BBB. METHODS: A group of 7 Wistar Unilever rats underwent paired (R)-11C-verapamil PET scans at an interval of 3 h: 1 baseline scan and 1 scan after intravenous injection of tariquidar (15 mg/kg, n = 5) or vehicle (n = 2). RESULTS: After tariquidar administration, the distribution volume (DV) of (R)-11C-verapamil was 12-fold higher than baseline (3.68 +/- 0.81 vs. 0.30 +/- 0.08; P = 0.0007, paired t test), whereas the DVs were essentially the same when only vehicle was administered. The increase in DV could be attributed mainly to an increased influx rate constant (K1) of (R)-11C-verapamil into the brain, which was about 8-fold higher after tariquidar. A dose-response assessment with tariquidar provided an estimated half-maximum effect dose of 8.4 +/- 9.5 mg/kg. CONCLUSION: Our data demonstrate that (R)-11C-verapamil PET combined with tariquidar administration is a promising approach to measure P-gp function at the BBB.  相似文献   
6.
Tendon injuries of the hand, especially flexor tendon injuries, should be treated by specially trained surgeons. Tendon injuries should be treated immediately to avoid joint stiffness or tendon adhesions, which arise predominantly at the tendon laceration. In addition to a professional operation, postoperative management is also important. As with surgery, specially trained physiotherapists should supervise the active or passive mobilization after tendon repair. A close cooperation between physiotherapist and physician is mandatory for an optimal result.  相似文献   
7.
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   
8.
9.
Summary BACKGROUND: Sacral nerve stimulation (SNS) is an option for the treatment of fecal incontinence in patients with morphologically intact, but weak external anal sphincter. METHODS: In ten patients a percutaneous test-SNS was performed. Two patients suffered from fecal incontinence after surgery, one patient after incomplete leg palsy after traumatic spine injury and seven patients from idiopathic incontinence. Incontinence score, anorectal manometry and patient diary were performed before and after test-SNS. RESULTS: Intraoperative response (Bellows action) could be achieved in 90% of patients. Test-SNS was successful in 50% of patients. In these patients, resting pressure was increased by 100.1% and squeeze pressure by 84.5%. CONCLUSIONS: SNS is an effective therapy in a subset of patients with fecal incontinence. Fifty percent of patients tested are eligible for implantation of a permanent stimulation device.   相似文献   
10.
We investigated parameters of nutrition, metabolism, and organ function after 4 wk of total parenteral nutrition (TPN) in baboons receiving either dipeptides or amino acids as the nitrogen source. The two groups showed no significant difference with respect to gain in body weight, nitrogen balance, plasma and muscle concentrations of amino acids, plasma concentrations of proteins, and leucine incorporation into muscle protein. All dipeptides were efficiently utilized as evidenced by trace concentrations of dipeptides in plasma and urine; they produced no deleterious effect on the function of liver, kidney, or immune system. Development of infection in several baboons increased urinary excretion of urea nitrogen but had no effect on urinary excretion of dipeptides and amino acids with the single exception of taurine, which was greatly increased. In conclusion, the data show long-term efficacy and safety of the dipeptide mixture as the sole nitrogen source for TPN.  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