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   227703篇
  免费   20472篇
  国内免费   4613篇
耳鼻咽喉   3450篇
儿科学   4423篇
妇产科学   3773篇
基础医学   17612篇
口腔科学   7594篇
临床医学   21332篇
内科学   21867篇
皮肤病学   2550篇
神经病学   11073篇
特种医学   5943篇
外国民族医学   12篇
外科学   21853篇
综合类   36455篇
现状与发展   9篇
一般理论   26篇
预防医学   31886篇
眼科学   2109篇
药学   21789篇
  388篇
中国医学   28875篇
肿瘤学   9769篇
  2024年   3523篇
  2023年   5479篇
  2022年   8890篇
  2021年   11435篇
  2020年   11292篇
  2019年   12347篇
  2018年   10775篇
  2017年   9325篇
  2016年   8262篇
  2015年   7757篇
  2014年   15304篇
  2013年   15669篇
  2012年   13647篇
  2011年   14513篇
  2010年   11743篇
  2009年   10142篇
  2008年   9330篇
  2007年   9362篇
  2006年   7986篇
  2005年   6712篇
  2004年   5571篇
  2003年   4951篇
  2002年   3785篇
  2001年   3162篇
  2000年   2799篇
  1999年   2279篇
  1998年   1803篇
  1997年   1635篇
  1996年   1338篇
  1995年   1280篇
  1994年   1137篇
  1993年   1001篇
  1992年   902篇
  1991年   828篇
  1990年   729篇
  1989年   700篇
  1988年   662篇
  1987年   584篇
  1986年   533篇
  1985年   1796篇
  1984年   2067篇
  1983年   1293篇
  1982年   1718篇
  1981年   1191篇
  1980年   1026篇
  1979年   909篇
  1978年   745篇
  1977年   557篇
  1976年   694篇
  1975年   479篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
This study was conducted to determine whether alcoholic and control subjects respond differently to manipulations that either enhance personal involvement (PI) or reduce negative affect (R, relaxation) on tests of neuropsychological function. In Phase 1, 48 male alcoholics and 36 male control subjects completed neuropsychological tasks under standard instructional sets. In Phase 2, subjects completed equivalent forms of these tests under one of three randomly assigned conditions; the PI condition in which subjects were encouraged to identify specific ways of improving their performance, the R condition in which subjects participated in a short relaxation exercise designed to reduce anxiety, or a No Treatment (NT) condition in which no attempt to manipulate the subjects' involvement or affect was made. Alcoholics were inferior to controls in both Phase 1 and Phase 2 [Fs (1,82) > 5.03, ps < 0.03]. The experimental manipulation differentially affected measures of negative affect and effort in the predicted direction. There were no group x condition interactions. Alcoholic and control subjects responded comparably to the experimental manipulations. This investigation, in combination with others using related manipulations, reinforces the hypothesis that alcohol-related cognitives dysfunction reflects an underlying deficit in brain states.  相似文献   
103.
Summary: It is not generally appreciated that intractable seizures involving the face area are amenable to surgical treatment. Twenty patients with onset of sensorimotor seizures in the face area of the pre- and postcentral gyri have been studied and surgically treated since 1948. Seizures started in the face, tongue, or throat, followed by diverse patterns depending on spread of seizure activity. Two patients had epilepsia partialis continua; 6 had either tonic or atonic drop attacks. All patients had pre- and postcentral face area resections, 12 in the dominant hemisphere. In addition, 3 had more extensive postcentral removal, 7 had temporal lobe, and 4 had small separate or contiguous frontal or parietal resection. Because the seizures were not sufficiently reduced by the first operation, 6 required reoperation; 4 of these patients had residual epileptiform activity on electrocorticogram (ECoG) after the first resection. Three patients had new neurologic signs that did not return to the preoperative level, but in 2 of them the deficit related mainly to higher resection in the central area. All but 2 of these 20 patients had at least moderate seizure reduction. Corticectomy can be performed for treatment of seizures arising in the lower central area and usually does not lead to significant permanent neurologic deficit.  相似文献   
104.
An automated measurement of total and free hydroxyproline in serum or urine is presented that uses flow injection analysis. After exclusion of nonspecific substances, hydroxyproline was oxidized by chloramine- T and L-cysteine with Ehrlich's reagent. The linearity obtained was from 3.8μmole/ L to 1.22 mmole/L with good precision (CV <3%). Comparison of the proposed method with HPLC yielded r = 0.939 as the correlation coefficient. Reference intervals of free and total hydroxyproline are 1.4–9.7 μmole/L, 3.8–27.2 μmole/L for serum, and 10.0–72.5 μmole/L, 25.2–303.6 μmole/L for urine, respectively. Serum free and total hydroxyproline levels in renal osteodystrophy patients on maintenance hemodialysis (N = 71) were significantly higher than in controls (P<0.0001). This method is superior to the use of HPLC with regard to stability of the color reaction. The measurement of serum free and total hydroxyproline is a useful marker for therapeutic observation of renal osteodystrophy patients. © 1994 Wiley-Liss, Inc.  相似文献   
105.
程乐 《实用医技杂志》2003,10(4):397-398
介入治疗是融合了内科药物治疗、外科手术治疗及医学影像学的一种特殊的治疗体系 ,其疗效受到世人瞩目并成为目前发展最为迅速的学科之一。但是 ,再好的方法也会存在不足之处 ,介入治疗也不例外。随着介入治疗在各家医院的普遍应用 ,并发症的发生也会越来越多 ,迫使人们关注这个问题。所谓介入治疗并发症 ,是指因血管造影及 (或 )血管内治疗所引起、需要一定治疗、使病人的治疗复杂化或延长病人住院时间的不良反应 ,就其全身多系统而言 ,介入治疗引发并发症的原因大致可归纳为两个主要因素即介入器材操作和引入人体内的物质(包括介入治疗所…  相似文献   
106.
Studies using magnetic resonance spectroscopy in human volunteers to evaluate their livers in vivo and to analyze their blood in vitro suggest that there are measurable amounts of silicon compounds in the blood of some women with implants and that there is migration of silicone to other organs such as the liver.  相似文献   
107.
BACKGROUND: Food allergy to cherry occurs throughout Europe, typically with restricted oral reactions in the central and northern parts but with frequent systemic reactions in the Mediterranean region. Previous studies have demonstrated insufficient sensitivity of commercially available cherry extract reagents in the diagnosis of cherry allergy. OBJECTIVE: To assess the diagnostic performance of specific IgE tests based on recombinant cherry allergens in comparison with an extract-based assay and to skin prick test (SPT). A secondary objective was to analyse the frequency of systemic reactions in cherry-allergic subjects across Europe, including the largest population of LTP-sensitized subjects from central Europe studied to date. METHODS: A total of 186 subjects from central Europe and Spain were studied. Serum IgE was analysed with ImmunoCAP tests carrying rPru av 1, 3 and 4, combined and separately, and cherry extract. RESULTS: Among the central European cherry allergics, the mix of rPru av 1, 3 and 4 had a sensitivity of 95%, compared with 65% for cherry extract, and the IgE binding capacity of the recombinant mix was considerably higher. The sensitivity of the two tests was more comparable in the Spanish population, 95% and 86%, respectively. The recombinant allergen ImmunoCAP equalled SPT in terms of sensitivity and specificity. Consistent with previous reports, major geographic differences in sensitization pattern and prevalence of systemic reactions were found. A significantly higher rate of systemic reactions was found in Spanish patients sensitized to Pru av 3 whereas German patients sensitized to LTP only had oral allergy syndrome. CONCLUSIONS: The recombinant cherry allergen ImmunoCAP is a highly sensitive diagnostic tool, clearly superior to any diagnostic method based on cherry extract. Three cherry allergens are sufficient for detecting sensitization in 95% of cherry-allergic subjects. Systemic reactions are common in LTP-sensitized individuals but seem to require at least one additional causative factor.  相似文献   
108.
Filiation, or a person's parentage, is one of the major componentsof someone's identity, often with important implications forthat person's welfare in social and personal terms. Fertilityspecialists are enjoined to consider the welfare of the child,and this is a legal requirement in assisted reproduction techniquesin the UK. This paper is in three parts, discussing some ofthe potential problems regarding filiation of the prospectivechild born of assisted reproduction techniques, in relationto the use of gametes and embryos. The first two parts concentrateon the status of children born as a result of treatment givenposthumously, and on filiation problems associated with donationof gametes or embryos, and surrogacy. The third part comparesBritish and French legislation with special regard to the welfareof the child, as well as underlining the common trends and principlesenunciated in both legislations. This is particularly appropriateat a time when the European Society for Human Reproduction andEmbryology is about to issue ethical guidelines in assistedreproduction, and when both the Council of Europe and the EuropeanCommission have commissioned studies on the implications ofthe assisted techniques, including those concerning status ofthe potential children.  相似文献   
109.
对107例甲状腺机能亢进症患者和91名正常人采用艾森克个性问卷及自编社会环境的调查显示:46.94%的患者起病前有负性生活事件发生,个性特征甲亢组神经不稳定型及掩饰性评分显著高于正常组,有显著性差异,此结果提示甲亢患者存在明显个性缺陷和负性生活事件,这些因素可作为甲亢发病的一种诱因。  相似文献   
110.
报道辐照氟银猪皮的制备、实验检测(弹性、创面粘附力和透水性测定,含银量测定)组织学检查细菌检测及抑菌试验研究,结果表明:辐照氟银猪皮除延伸度低于未辐照猪皮外,其撕裂强度、创面粘合力和透水性均与未辐照猪皮相似。组织学检查示:辐照氟银猪皮组织结构完整,表皮细胞部分空泡形成。组织细菌检测证明其无菌生长,达到无菌要求。抑菌试验证明对金黄色葡萄球菌、绿脓杆菌、大肠杆菌、变形杆菌、克雷伯氏菌均有极强的抑菌作用  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