全文获取类型
收费全文 | 23957篇 |
免费 | 1073篇 |
国内免费 | 707篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 776篇 |
妇产科学 | 310篇 |
基础医学 | 1800篇 |
口腔科学 | 106篇 |
临床医学 | 2875篇 |
内科学 | 3120篇 |
皮肤病学 | 193篇 |
神经病学 | 330篇 |
特种医学 | 1357篇 |
外科学 | 6529篇 |
综合类 | 3465篇 |
预防医学 | 897篇 |
眼科学 | 89篇 |
药学 | 2078篇 |
12篇 | |
中国医学 | 802篇 |
肿瘤学 | 873篇 |
出版年
2023年 | 266篇 |
2022年 | 644篇 |
2021年 | 812篇 |
2020年 | 744篇 |
2019年 | 734篇 |
2018年 | 791篇 |
2017年 | 681篇 |
2016年 | 698篇 |
2015年 | 755篇 |
2014年 | 1554篇 |
2013年 | 1462篇 |
2012年 | 1379篇 |
2011年 | 1398篇 |
2010年 | 1119篇 |
2009年 | 1253篇 |
2008年 | 1246篇 |
2007年 | 1223篇 |
2006年 | 1062篇 |
2005年 | 963篇 |
2004年 | 717篇 |
2003年 | 638篇 |
2002年 | 496篇 |
2001年 | 493篇 |
2000年 | 449篇 |
1999年 | 337篇 |
1998年 | 328篇 |
1997年 | 274篇 |
1996年 | 272篇 |
1995年 | 286篇 |
1994年 | 282篇 |
1993年 | 212篇 |
1992年 | 248篇 |
1991年 | 199篇 |
1990年 | 172篇 |
1989年 | 148篇 |
1988年 | 191篇 |
1987年 | 132篇 |
1986年 | 95篇 |
1985年 | 99篇 |
1984年 | 104篇 |
1983年 | 51篇 |
1982年 | 96篇 |
1981年 | 86篇 |
1980年 | 98篇 |
1979年 | 78篇 |
1978年 | 56篇 |
1977年 | 60篇 |
1976年 | 56篇 |
1975年 | 33篇 |
1973年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
T. V. Bilfinger F. C. Seifert A. M. Vallone T. M. Biancaniello 《Pediatric cardiology》1994,15(2):100-102
Summary Although recognized by pediatric cardiac surgeons, aortic insufficiency as a technical complication after tetralogy of Fallot repair is poorly documented, especially if it occurs late. The case of a boy with aortic insufficiency 10 years after complete tetralogy repair is described. No documentation in the literature other than summary statements in textbooks of this occurence was found. 相似文献
122.
Computed duplex sonography was used to examine the renal arteries in 36 hypertensive children and adolescents (ages 4–17 years) with arterial hypertension of either renal or non-renal origin. Time-averaged flow velocities, maximum blood flow velocities as well as absolute renal blood flow and renal blood flow per gram kidney weight were measured. Normal flow velocities and normal to elevated renal blood flow volume was found in patients with acute glomerulonephritis and those with signs of chronic glomerulonephritis onset. Patients having advanced stages of chronic glomerulonephritis, on the other hand, were characterized by lower levels of all parameters. Unilateral renal artery stenosis was diagnosed correctly in four patients, although one intra-renal artery stenosis escaped imaging. Scarred kidneys exhibited low-normal or reduced flow velocities and renal blood flow volumes corresponded roughly to kidney size and preservation of normal kidney structure. Hypertension in some patients with normal kidneys showed a tendency to cause higher renal blood flow without consistent acceleration of blood flow velocities. We conclude that duplex sonography is a suitable primary diagnostic tool in measuring blood flow velocities and absolute renal blood flow volume in hypertensive children, thus facilitating the choice of the next diagnostic step. 相似文献
123.
糖尿病肾病临床研究述评 总被引:54,自引:0,他引:54
本文从中医病名、病因病机、诊断标准、临床分期、疗效评定、辨证论治、临床科研七个方面对糖尿病肾病的研究进行了述评。指出:糖尿病肾病的中医病名、诊断、分期及疗效评定标准亟待统一;立足于临床实际,参考现代医学有关认识,应用DME方法,开展糖尿病肾病临床和实验研究,深入探讨其病因病机和证治规律,在中医基本理论指导下,大胆创新,是提高临床疗效的关键;分期辨证论治较为符合疾病的发展规律,便于寻找防治糖尿病肾病的有效方法。 相似文献
124.
F. J. B. Sampaio 《Urological research》1992,20(4):271-274
Summary The growth of fetal kidney volume was studied in 290 specimens taken from 145 fresh human fetuses (85 males and 60 females) with gestational age ranging from 13 to 36 weeks postconception (WPC). Normative equations and curves of the growth of renal volume were obtained for male and female fetuses and for the whole sample in the second trimester (13–24 WPC) and in the third trimester (25–36 WPC) of gestation. There was no difference between the growth in volume of the right and left kidneys. Fetal kidney volume increases with a more intense rhythm in the early fetal period (13–24 WPC). During the second trimester, there was no difference between the values for renal volume of male and female fetuses. In the third trimester, male fetuses had renal volumes significantly greater than the female fetuses. The normative parameters of renal volume could have practical applications in detection and monitoring of renal anomalies in fetal and perinatal urology.Supported by grants 302, 369/86.4/BM-FV from the National Conucil of Scientific and Technological Development (CNPq, Brazil) and Grant E.29/170.787/89 from the Rio de Janeiro Foundation for Research Support (FAPERJ). 相似文献
125.
Tatsuya Okimoto Hiroshi Yahata Yasuhiko Fukuda Keisuke Hayamizu Kiyohiko Dohi 《Transplant international》1994,7(S1):629-633
Abstract A study was conducted to elucidate the mechanism of donor-pecific Mixed Lymphocyte Reaction (MLR and Cell Mediated Lymphotoxicity (CML) unresponsiveness in a renal transplant recipient with a long-term well-functioning kidney. The peripheral blood lymphocytes (PBL) of the recipient, who had not shown rejection since his transplantation 5 years previously, and those of his mother (donor), his father and two healthy third parties were examined. MLR, CML, semimicro MLR in a double chamber, interleukin-2 (IL-2) synthesis assay and limiting dilution assay were performed. This recipient showed donor-pecific MLR and CML unresponsiveness. IL-2 assay showed that the PBL of the recipient produced less IL-2 against the donor than against the father and the third parties. The addition of exogenous recombinant IL-2 (rIL-2; Takeda Co.) to the priming MLR caused a recovery of CML against the donor. A limiting dilution assay indicated that cytotoxic T cell precursor (CTLp) frequencies against the donor and father did not differ. The suppressor assay in a double chamber indicated that the PBL of the recipient stimulated by the donor PBL had a non-pecific suppressive effect on MLR, CML and IL-2 synthesis of the PBL across the Major Histocompatibility Complex (MHC) barrier. This suppressive effect was abolished by OKT3 or OKT8 monoclonal antibody and complement. Thus, the recipient had donor-pecific suppressor T cells that produced a humoral non-pecific suppressive factor only when stimulated by the donor PBL, and this factor suppressed PLR and CML by inhibiting IL-2 synthesis of the PBL. 相似文献
126.
报告接受彩色多普勒超声心动图检查的老年患者162例,其中75例有不同程度的主要动脉瓣关闭不全(Ar)。老年(Ar)的病因构成与中,老年前期者明显不同,主动脉,瓣钙化及原因不明者的比例占多数(67%)。主动脉瓣钙化者Ar程度多较重。主动脉瓣钙化及原因不明Ar患者的其他三个瓣膜返流检出率及和程度均明显高于无Ar的老年患者。表明多瓣膜退行性病变是此类Ar患者的原因之一。 相似文献
127.
18F-氟代脱氧葡萄糖(18F-FDG)PET在肾恶性肿瘤中主要应用于原发肿瘤定性诊断和分期、肿瘤局部复发及远处转移病灶诊断等。PET检查对选择治疗方案的影响主要由于发现远处转移病灶和对病灶定性。并优于CT等常规检查。但18F-FDG PET对诊断原发性肾细胞癌敏感性低于CT,可能与肿瘤分级或某些特性有关。 相似文献
128.
High incidence of multiple kidney stone formation has been observed among workers exposed to cadmium (Cd). Citrate is known to be a protective factor against renal stone formation. To study the direct effect of cadmium on citrate uptake by the renal brush border membrane, we exposed isolated rat renal brush border membrane vesicles (BBMV) to cadmium and determined their citrate uptake characteristics. BBMV were prepared by the divalent cation precipitation method. Citrate uptake was measured by the Millipore rapid membrane filtration technique. Preincubation of BBMV with 2 and 10 mM CdCl2 for 1 min significantly inhibited citrate uptake compared with that of BBMV without Cd. Analysis of the time course of citrate uptake during 30-min preincubation of BBMV with 0.5 mM Cd also revealed significant reduction of the uptake compared with that of the control BBMV without preincubation. These findings indicate that preincubation of BBMV with cadmium results in time-dependent and concentration-dependent inhibition of citrate uptake. 相似文献
129.
复方肾华治疗大鼠改良慢性血清病肾炎的实验研究 总被引:2,自引:0,他引:2
目的 观察复方肾华胶囊对改良大鼠慢性血清病肾炎模型的治疗作用。方法 采取传统大鼠慢性血清病肾炎模型制作方法加上切除大鼠一侧肾脏、隔日饮饲牛血清白蛋白 (BSA)酸化水、腹腔注射大肠杆菌内毒素 (LPS)等措施 ,制作肾炎模型 ,与西药蒙诺作对照 ,观察中药肾华对肾炎大鼠尿蛋白、血生化、凝血指标、肾功能、病理、免疫荧光以及增殖细胞核抗原 (PCNA)表达的作用。结果 肾华胶囊能够显著减轻肾炎大鼠肾脏重量及肾重指数、降低肾炎大鼠尿蛋白、升高血清蛋白、降低胆固醇、甘油三酯、改善肾功能、纠正凝血功能紊乱、减轻肾脏病理改变、减轻免疫荧光变化、减弱PCNA的表达。结论 中药肾华胶囊对大鼠慢性血清病肾炎模型有较好的治疗作用 相似文献
130.
Endothelin-1 in children with chronic renal failure 总被引:1,自引:0,他引:1
Isabelle Blazy Michèle Déchaux Marina Charbit Danièle Brocart Jean-Claude Souberbielle Marie France Gagnadoux François Guillot Charles Sachs 《Pediatric nephrology (Berlin, Germany)》1994,8(1):40-44
Endothelin-1 (ET-1) was meansured after extraction from plasma of normal adults (5.9±1.9 pg/ml,n=22), normal children (7.1±1.86 pg/ml,n=29), nonhaemodialysed children with chronic renal failure (CRF) (11.1±1.8 pg/ml),n=10), renal graft recipients (9.5±3.4 pg/ml,n=37), haemodialysed children 24 h after a haemodialysis session (20.02±10.9 pg/ml,n=26) and haemodialysed children before and after a haemodialysis session (15.31±10.6 and 13.8±8.5 respectively,n=14). A sensitive and specific radioimmunoassay was used. ET-1 was significantly higher in non-haemodialysed CRF children and in renal graft recipients than in normal children (P<0.001 andP<0.01, respectively) and significantly higher in haemodialysed children when compared with normal children, non-haemodialysed CRF children and renal graft recipients (P<0.001). ET-1 concentrations were similar in normal children and normal adults. ET-1 was inversely correlated with glomerular filtration rate in non-haemodialysed CRF children (r=–0.39,P<0.01) and positively correlated with extracellular volume in haemodialysed children (r=0.435,P<0.03). After haemodialysis, ET-1 increased in 6 and decreased in 8 of the 14 children studied before and after a haemodialysis session. 相似文献