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   1302篇
  免费   72篇
  国内免费   5篇
耳鼻咽喉   9篇
儿科学   62篇
妇产科学   52篇
基础医学   152篇
口腔科学   28篇
临床医学   106篇
内科学   377篇
皮肤病学   9篇
神经病学   133篇
特种医学   44篇
外科学   114篇
综合类   3篇
预防医学   65篇
眼科学   8篇
药学   106篇
中国医学   2篇
肿瘤学   109篇
  2023年   12篇
  2022年   7篇
  2021年   21篇
  2020年   26篇
  2019年   23篇
  2018年   41篇
  2017年   26篇
  2016年   43篇
  2015年   41篇
  2014年   38篇
  2013年   76篇
  2012年   78篇
  2011年   77篇
  2010年   44篇
  2009年   40篇
  2008年   54篇
  2007年   49篇
  2006年   61篇
  2005年   64篇
  2004年   55篇
  2003年   48篇
  2002年   38篇
  2001年   27篇
  2000年   8篇
  1999年   24篇
  1998年   8篇
  1997年   7篇
  1996年   8篇
  1995年   9篇
  1994年   9篇
  1992年   25篇
  1991年   15篇
  1990年   20篇
  1989年   21篇
  1988年   26篇
  1987年   25篇
  1986年   25篇
  1985年   22篇
  1984年   12篇
  1983年   7篇
  1982年   8篇
  1981年   7篇
  1979年   12篇
  1978年   7篇
  1977年   10篇
  1975年   7篇
  1974年   8篇
  1971年   6篇
  1969年   6篇
  1967年   9篇
排序方式: 共有1379条查询结果,搜索用时 109 毫秒
71.
72.
73.
74.
The incidence of pelvic organ prolapse is 18% in women with bladder exstrophy. A vaginal technique to correct the prolapse may be preferable in these women with multiple abdominal operations in their histories. We have performed a modified Prolift™ procedure for the repair of severe uterine prolapse in two young women. A review of the literature is presented.  相似文献   
75.
Histologic features of 134 cases of human papilloma virus (HPV) cervical infection and cervical intraepithelial neoplasia (CIN) were reviewed and correlated with colposcopic diagnosis on the basis of two different grading methods: International Nomenclature for Colposcopy showed 79.1% predictive accuracy and Reid's improved colposcopic index 86.6% of accurate predictions (significant difference at P less than 0.05). Overestimation difference was the most significant, with 23 overestimates in International Classification and 11 in Reid's score (P less than 0.01).  相似文献   
76.
This is the first report of obesity in an untreated coeliac patient diagnosed at the age of 5.1 years according to the criteria of the European Society for Paediatric Gastroenterology. Diagnosis of coeliac disease was suspected on the basis of recurrent episodes of abdominal pain and of family history. Gluten-free diet induced evident acceleration of both length and weight velocity and increase of weight excess, apart from resolution of the abdominal symptoms. The present case report demonstrates that obesity in a child does not exclude the diagnosis of coeliac disease.  相似文献   
77.
BACKGROUND: It hs been reported that some glaucoma patients have deficient endothelial nitric oxide production. The effect of the presupposed nitrovasodilators CEDO 8956 and hydralazine hydrochloride (HCl) on bovine retinal microcirculation pericytes and ophthalmic artery smooth muscle cells are investigated. METHODS: Cells were cultured on silicone membranes and their contractile tone observed by phase contrast inverted microscopy before and after exposure by fluid exchange to different drugs at various concentrations. Experiments were conducted with pericytes in the absence (control) or in the presence (10 nM - 0.1 mM) of CEDO 8956, hydralazine HCl, or sodium nitroprusside (SNP). Experiments were conducted with smooth muscle cells in the absence (control) or in the presence (0.1 mM) of CEDO 8956, or hydralazine HCl. RESULTS: In comparison to control (- 0.56 +/- 10 %), pericytes were significantly relaxed by SNP (100 +/- 0 %, p < 0.001), but not by CEDO 8956 (9.2 +/- 15.4 %) or hydralazine HCl (20.6 +/- 4.4 %). In comparison to control (1.64 +/- 5.3 %), smooth muscle cells were significantly relaxed by CEDO 8956 (46.2 +/- 12.4 %, p < 0.05) and hydralazine HCl (54.9 +/- 9.1 %, p < 0.001). CONCLUSIONS: These results suggest a possible heterogeneity between cultured bovine microcirculation pericytes and ophthalmic artery vascular smooth muscle cells in the relaxing response to CEDO 8956 and hydralazine HCl. Apparently, these two drugs might not be first choice candidates in order to attempt to try to selectively improve circulation in the retina or the optic nerve head capillary network.  相似文献   
78.
PURPOSE: To evaluate the efficacy and side effects of psolaren with ultraviolet light A (PUVA) and interferon-alpha-2a (IFN-alpha-2a) in patients with mycosis fungoides (MF) and Sézary syndrome (SS). PATIENTS AND METHODS: From May 1993 to January 1999, 63 symptomatic patients with all stages of MF and SS were treated in a prospective Phase II trial with systemic escalating doses of IFN-alpha-2a combined with PUVA for 1 year, followed by indefinite PUVA maintenance in complete responding patients. RESULTS: Sixty-three patients were enrolled (Stage IA, n = 6; IB, n = 37; IIA, n = 3; IIB, n = 3; III, n = 12; IVA, n = 2). Ten patients had received previous therapy. The median follow-up duration for the entire cohort is 37 months. Of 63 patients, 51 achieved a complete response (CR; 74.6%) or partial response (PR; 6%) to therapy. The median response duration is 32 months. The 5-year overall survival rate is 91% and the 5-year disease-free survival rate is 75%. No life-threatening side effects were observed. Five patients stopped IFN-alpha-2a therapy due to toxicity. Eighty-four percent of the patients received more than 75% of the planned dose (12 million units three times a week). CONCLUSIONS: This combination of IFN-alpha-2a and phototherapy is an effective and safe therapy for patients with symptomatic MF.  相似文献   
79.
Adenosine is an endogenous antiaggregating substance that influences the platelet responses through specific A-type receptors that activate adenylate cyclase increasing the levels of 3',5'-cyclic adenosine monophosphate (cAMP). In this study, we investigated whether adenosine can also influence the levels of 3',5'-cyclic guanosine monophosphate (cGMP) and decrease the aggregating response of human platelets to adenosine-5-diphosphate (ADP) through this nucleotide. In platelet samples from healthy volunteers, we evaluated the effect of adenosine on ADP-induced aggregation and cyclic nucleotide synthesis. Some experiments were repeated in the presence of dipyridamole (inhibitor of adenosine uptake and phosphodiesterase activity), N(G)-monomethyl-L-arginine (L-NMMA, nitric synthase inhibitor), ionomycin (calcium ionophore), and ambroxol (2-amino-3,5-dibromo-N-[trans-4-hydroxycyclohexyl]benzylamine, inhibitor of nitric oxide (NO)-dependent activation of guanylate cyclase). Adenosine decreased the response to ADP in a concentration-dependent way (analysis of variance, ANOVA: P<.0001): cAMP levels increased from 30.0 +/- 2.0 (control) to 46.0 +/- 3.0 pmol/10(9) platelets (in the presence of 15 mumol/l adenosine) and cGMP levels increased from 5.6 +/- 1.0 (control) to 10.9 +/- 2.0 pmol/10(9) platelets (in the presence of 15 mumol/l adenosine). Also, nucleotide levels measured at the end of aggregation were higher in platelet samples exposed to adenosine than in controls. Dipyridamole at 40 mumol/l slightly increased adenosine's effects on both nucleotides. L-NMMA blunted the effect of adenosine on cGMP both in unstimulated samples and in aggregated platelets without any effect on cAMP synthesis. Platelet exposure to L-NMMA and ambroxol partially prevented adenosine's effect on ADP-induced aggregation. In conclusion, adenosine, which enhances intraplatelet cAMP levels, was determined to also cause an increase in cGMP concentrations through a mechanism that involves NO synthesis. This effect plays a direct role in the adenosine-induced antiaggregation.  相似文献   
80.
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