全文获取类型
收费全文 | 18148篇 |
免费 | 1144篇 |
国内免费 | 387篇 |
专业分类
耳鼻咽喉 | 308篇 |
儿科学 | 502篇 |
妇产科学 | 883篇 |
基础医学 | 2270篇 |
口腔科学 | 1084篇 |
临床医学 | 1874篇 |
内科学 | 1471篇 |
皮肤病学 | 124篇 |
神经病学 | 2578篇 |
特种医学 | 553篇 |
外国民族医学 | 1篇 |
外科学 | 2030篇 |
综合类 | 2394篇 |
预防医学 | 718篇 |
眼科学 | 304篇 |
药学 | 1609篇 |
5篇 | |
中国医学 | 587篇 |
肿瘤学 | 384篇 |
出版年
2024年 | 30篇 |
2023年 | 226篇 |
2022年 | 413篇 |
2021年 | 624篇 |
2020年 | 572篇 |
2019年 | 536篇 |
2018年 | 528篇 |
2017年 | 505篇 |
2016年 | 549篇 |
2015年 | 598篇 |
2014年 | 923篇 |
2013年 | 1115篇 |
2012年 | 900篇 |
2011年 | 1060篇 |
2010年 | 876篇 |
2009年 | 832篇 |
2008年 | 792篇 |
2007年 | 771篇 |
2006年 | 758篇 |
2005年 | 668篇 |
2004年 | 591篇 |
2003年 | 488篇 |
2002年 | 399篇 |
2001年 | 369篇 |
2000年 | 347篇 |
1999年 | 316篇 |
1998年 | 282篇 |
1997年 | 279篇 |
1996年 | 293篇 |
1995年 | 291篇 |
1994年 | 287篇 |
1993年 | 220篇 |
1992年 | 207篇 |
1991年 | 191篇 |
1990年 | 174篇 |
1989年 | 149篇 |
1988年 | 164篇 |
1987年 | 136篇 |
1986年 | 143篇 |
1985年 | 197篇 |
1984年 | 159篇 |
1983年 | 111篇 |
1982年 | 140篇 |
1981年 | 121篇 |
1980年 | 80篇 |
1979年 | 65篇 |
1978年 | 77篇 |
1977年 | 41篇 |
1976年 | 26篇 |
1973年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.
小切口治疗后交叉韧带胫骨起点撕脱骨折 总被引:1,自引:1,他引:0
膝关节炎(osteoarthritis,OA)是膝关节的慢性退行性疾病,多发于中老年患者,主要病变位置在膝关节承重区的软骨,当软骨发生磨损、破坏时,作为基质主要成分的蛋白多糖(protoglycan,PG)大量分散于关节液中,与人体代谢相关[1],成为可以定量分析关节软骨破坏程度的有效灵敏指标[2]。我院对膝骨关节炎患者采用内服补肝益肾、活血通络中药及关节腔内玻璃酸钠注射,同时以单纯的玻璃酸钠注射作为对照,分别在治疗前后抽取关节液,行PG定量检查,对两组的PG变化趋势进行观察,现将结果报告如下。1资料和方法1·1一般资料将2006年12月至2007年3月的60例… 相似文献
93.
目的通过检测子宫内膜异位症(EMs)患者血清及腹腔液中血小板衍生生长因子(PDGF)、血管细胞粘附分子-(VCAM-1)浓度,探讨PDGF和VCAM-1在EMs发病中的作用。方法选取手术后病理证实为EMs的40例患者为EMs组,其中I~II期17例,III~IV23例;非EMs组20例作为对照组。应用酶联免疫吸附法(ELISA)检测血清及腹腔液中PDGF和VCAM-1水平。结果EMs组血清及腹腔液中PDGF、VCAM-1水平均明显高于对照组(P<0.01)。随EMs期别的增加,其血清和腹腔液中PDGF、VCAM-1含量呈上升趋势;EMsIII~IV期水平显著高于I~II期(P<0.05)。EMs患者PDGF与VCAM-1呈正相关性(P<0.05)。结论EMs患者PDGF、VCAM-1表达水平升高,在EMs的发生发展中具有重要作用。 相似文献
94.
FLAIR序列脑室内脑脊液搏动伪影(VCSFA)的表现及初步分析 总被引:1,自引:0,他引:1
目的探讨FLAIR序列脑室内脑脊液搏动伪影的表现及其与年龄、性别、脑室大小的关系。方法对100例正常成人行头颅MR检查,并对FLAIR序列脑室内脑脊液搏动伪影(VCSFA)进行观察统计分析。结果VCSFA表现为脑室内轻微或明显高信号,在Ⅲ,Ⅳ脑室最常见,在不同年龄组存在明显差异(P<0.05),VCSFA组Ⅲ,Ⅳ脑室左右径大于无VCSFA组(P<0.05)。结论VCSFA是由反转延迟造成的,随着年龄增长及脑室增大,VCSFA出现频率增加,与性别无关。 相似文献
95.
腰大池持续外引流的临床观察与护理 总被引:3,自引:0,他引:3
笔者报道72例腰大池持续外引流病人的观察与护理。认为对于腰穿持续外引流的病人,观察脑脊液的性质、量,严密观察病情变化,加强引流管的护理及基础护理,增强营养,是提高治愈率,减少并发症的重要措施。 相似文献
96.
AMAL KANBOUR-SHAKIR DAVID T. ARMSTRONG ANNE ROULEAU HEINZ W. KUNZ THOMAS J. GILL 《American journal of reproductive immunology (New York, N.Y. : 1989)》1995,33(5):367-372
PROBLEM : To determine whether seminal fluid influences the expression of MHC class I antigens on the surface of basal trophoblast cells in the placenta of the rat. METHODS : Transfer of DA × DA embryos into a WF (allogeneic) or DA (syngeneic) recipient made pseudopregnant by hormonal treatment followed by mating with a vasectomized male (seminal fluid) or by mechanical stimulation (no seminal fluid). Antigen expression was determined by electron microscopic immunocytochemistry using the appropriate gold-labeled monoclonal antibodies. RESULTS : Seminal fluid did not affect the expression of MHC class I antigens on the surface of the basal trophoblast in either allogeneic or syngeneic matings. CONCLUSIONS : The suppression of the expression of paternal class I antigens on the surface of the basal trophoblast cells in allogeneic pregnancies most likely occurs at the genome level shortly after fertilization. 相似文献
97.
头低位模拟失重状态对前庭功能的影响 总被引:4,自引:1,他引:3
为研究头低位模拟失重对运动病症状、垂直视动眼震(VOKN)及体液重新分配的影响,在头低位-10°的模拟失重状态下,采用大视野的垂直视动刺激,观察18名正常人的运动病症状、VOKN、激素(AVP、VIP、CORT、ALDO)的反应特点。结果表明,头低位-10°状态下的大视野垂直视动刺激可以诱发出明显的运动病症状,头低位-10°的垂直视动刺激比坐位更容易诱发运动病。坐位状态VOKN慢相速度有明显的方向性不对称,敏感组VOKN方向性不对称有显著差异(P<0.05)。头低位-10°时VOKN的不对称现象不明显,向下方向运动的VOKN慢相速度显著增加。分析指出,头低位-10°状态下垂直视动刺激比坐位和秋千刺激的贡献率大。尿中CORT(皮质醇)在秋千和头低位的垂直视动刺激前后有显著性增加。提示:大视野的垂直视动刺激与头低位-10°两种刺激的结合可能成为预测空间运动病的方法之一. 相似文献
98.
99.
S. Jepsen A. Rühling K. Jepsen B. Ohlenbusch H.K. Albers 《Clinical oral implants research》1996,7(2):133-142
The aim of this prospective study was to characterize an implant patient population exhibiting clinical signs of peri‐implantitis and to determine subsequently the incidence of progressive attachment loss. The predictive values of diagnostic parameters were evaluated. 25 patients with 54 endosseous implants that had been loaded for 41±15 months were included in the study. Clinical parameters included the assessment of plaque, bleeding on probing, probing depth, attachment levels, and Periotest® values. Probing measurements were performed in duplicate by means of a controlled force electronic probe (Periprobem). Peri‐implant crevicular fluid samples were collected and assayed for neutral proteolytic enzyme (NPE) activity (Periocheck®). Analysis of duplicate baseline probing data revealed a high degree of reproducibility (mean difference: 0.1±0.3mm). A minimum threshold of 1.0mm (>3×S.D.) loss of probing attachment was chosen to classify a site as positive for breakdown. Alternatively, the tolerance method was employed to identify sites with progressive attachment loss. After 6 months, irrespective of the analytical method, 6 percent of all sites (in 19% of the implants) and 28% of the patients had experienced further per attachment loss. There were significant differences ( p <0.05) in mean plaque (73% vs. 45%) and NPE (36% vs. 12%) scores between patients with progressive peri‐implantitis and those with stable peri‐implant conditions. Both bleeding on probing and the NPE‐test were characterized by high negative predictive values, and thus negative scores can serve as indicators for stable peri‐implant conditions. For monitoring peri‐implant health during recall visits, attachment level recordings with a controlled force electronic probe in conjunction with enzymatic diagnostic tests of the host response can be recommended. 相似文献
100.
Frequency and causes of shunt revisions in different cerebrospinal fluid shunt types 总被引:3,自引:0,他引:3
B. M. Borgbjerg F. Gjerris M. J. Albeck J. Hauerberg S. E. Børgesen 《Acta neurochirurgica》1995,136(3-4):189-194
Summary Shunt complications and revisions are common in hydrocephalic patients treated with a ventriculo-atrial or a ventriculo-peritoneal shunt. The reported revision rate differs very much but the rate of revision is close to 50% in many papers. Data from 884 hydrocephalic patients treated with various shunt types in the period 1958–1989 were recorded retrospectively in order to evaluate the frequency of revision for various shunt types and secondly to analyse the specific reasons for the shunt revisions.The rate of shunt revision was 45%. The Pudenz shunt was revised more often (62%) than the remaining shunt types. The Hakim and the Orbis-Sigma shunts had fewer revisions (35% and 27%, respectively) than the other observed shunt types. A defect of or an obstruction in the ventricular catheters was a frequent cause of revision followed by a defect or an obstruction of the distal catheter, a displacement of the distal catheter and an acute infection. Because of the higher rate of revision for the Pudenz shunt the rate of the above mentioned specific complications is also higher in most of the subgroups for that specific shunt type. Driven by these experiences it is reasonable to seek to develop and introduce new shunt types in an attempt to reduce the complication rate. 相似文献