全文获取类型
收费全文 | 1866篇 |
免费 | 186篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 131篇 |
妇产科学 | 97篇 |
基础医学 | 178篇 |
口腔科学 | 53篇 |
临床医学 | 300篇 |
内科学 | 354篇 |
皮肤病学 | 35篇 |
神经病学 | 148篇 |
特种医学 | 183篇 |
外科学 | 164篇 |
综合类 | 41篇 |
预防医学 | 134篇 |
眼科学 | 16篇 |
药学 | 152篇 |
1篇 | |
中国医学 | 9篇 |
肿瘤学 | 75篇 |
出版年
2023年 | 11篇 |
2021年 | 17篇 |
2020年 | 27篇 |
2019年 | 24篇 |
2018年 | 35篇 |
2017年 | 39篇 |
2016年 | 36篇 |
2015年 | 35篇 |
2014年 | 49篇 |
2013年 | 59篇 |
2012年 | 50篇 |
2011年 | 77篇 |
2010年 | 59篇 |
2009年 | 86篇 |
2008年 | 67篇 |
2007年 | 89篇 |
2006年 | 54篇 |
2005年 | 56篇 |
2004年 | 44篇 |
2003年 | 40篇 |
2002年 | 38篇 |
2001年 | 42篇 |
2000年 | 42篇 |
1999年 | 40篇 |
1998年 | 82篇 |
1997年 | 96篇 |
1996年 | 65篇 |
1995年 | 57篇 |
1994年 | 45篇 |
1993年 | 51篇 |
1992年 | 39篇 |
1991年 | 36篇 |
1990年 | 33篇 |
1989年 | 56篇 |
1988年 | 48篇 |
1987年 | 50篇 |
1986年 | 44篇 |
1985年 | 51篇 |
1984年 | 29篇 |
1983年 | 20篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 16篇 |
1978年 | 8篇 |
1977年 | 15篇 |
1976年 | 12篇 |
1973年 | 10篇 |
1969年 | 7篇 |
1968年 | 7篇 |
1967年 | 9篇 |
排序方式: 共有2098条查询结果,搜索用时 15 毫秒
81.
Stimulation of dopamine D1-receptors by SKF 82958 increased extracellular neurotensin (NT) levels in the striatum and nucleus accumbens as measured by in vivo microdialysis while blockade of D1-receptors had no effect. Antagonism of NMDA receptors with MK 801 completely prevented the increased NT release induced by D1-stimulation in both structures. Tissue content of striatal NT anterior and posterior to the microdialysis probe was oppositely altered by D1-stimulation: increases were observed in the anterior striatum with decreased NT levels in the posterior striatum. 相似文献
82.
83.
HLA class I antigens (Bg) on red cells (RBCs) are expressed by some normal donors and by many patients with systemic lupus erythematosus (SLE). To identify the membrane components previously detected by hemagglutination with HLA class I-specific monoclonal antibodies (MoAbs), RBC membrane preparations were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotted with the HLA class I MoAbs. Two components were obtained that reacted with the MoAbs: a heavy chain of 45 kDa and a light chain termed beta2-microglobulin (beta2-M) of 11 kDa. The effect of chloroquine and acid elution in stripping HLA antigens is shown to be due to the removal of beta2-M, as only that component was detected in eluates from reactive RBCs. Neither antibody elution method affected the heavy chain expression assessed by immunoblotting. It is concluded that HLA class I antigens on RBCs are integral membrane components of the type normally found and wisely distributed on many nucleated cells. Platelets, which have stronger HLA class I antigen expression, were also studied, and their membrane preparations yielded heavy chain and beta2-M molecules; the effect of chloroquine treatment was harder to assess than that of acid elution, owing to the sensitivity with which both components are detected in immunoblotting. In eluates obtained from acid treatment only beta2-M is detected. 相似文献
84.
Transcatheter closure of patent ductus arteriosus using the AMPLATZER™ duct occluder II (ADO II) 下载免费PDF全文
85.
范春明 《中国组织工程研究与临床康复》2007,11(24):4806-4809
目的:分析胚胎干细胞和胚胎生殖细胞的生物学特性、体外培养条件、周围微环境对其增殖分化的影响,了解胚胎干细胞和胚胎生殖细胞的关系和应用前景。方法:应用计算机检索万方数据库2000/2007有关生殖细胞、胚胎干细胞、胚胎生殖细胞的相关研究文章,检索词:生殖细胞,胚胎干细胞,胚胎生殖细胞,并限定文章语言种类为中文;同时应用计算机检索PUBMED2000/2006相关文章,检索词:Germ Cells,Primordial germ cells,Embryonic stem cells,Embryonic Germ Cells,限定文章语言种类为“English”。对资料进行初审,纳入标准为有关生殖细胞、胚胎干细胞、胚胎生殖细胞的生物学特性、体外培养及生长抑制因子的作用等相关文章,并查找全文。主要选择基础研究类文章,无论有无对照组均纳入。结果:共检索到相关文章59篇,排除比较陈旧的文章,最后纳入38篇进行总结分析。胚胎干细胞与胚胎生殖细胞分别从附置前早期胚胎内细胞团和早期胎儿生殖嵴原始生殖细胞分离克隆出来,均具有自我更新、无限增殖能力及多向分化潜能,在体外培养条件下可保持稳定的二倍体核型,诱导分化后可形成3种胚胎生殖层。饲养层细胞是人胚胎生殖细胞体外培养的必要条件,常用饲养层细胞有鼠STO细胞系、鼠胚胎成纤维细胞,体外生长所需主要细胞因子包括干细胞生长因子、碱性成纤维细胞生长因子和白血病抑制因子,然而只要在培养基中加入鼠成纤维细胞的上清液和碱性成纤维细胞生长因子,胚胎干细胞可在无饲养层的条件下进行体外培养。结论:胚胎干细胞和胚胎生殖细胞具有相似的增殖特性,一定条件下可以分化为包括生殖细胞在内的所有功能细胞,并可相互转变,在胚胎发育、基因治疗、药物筛选、新药开发、生殖医学及人类疾病的移植治疗中具有广泛的应用前景。 相似文献
86.
87.
OBJECTIVE: To test the hypothesis that desmopressin facilitates acquisition of continence, we aimed to establish whether, in children with nocturnal enuresis who are desmopressin nonresponders, adjunct desmopressin increases the rate of sustained continence after treatment with a conditioning alarm.Study design Patients with nocturnal enuresis (n=358; age range, 6-16 years) completed a 4-week "run-in" course of intranasal desmopressin (20-40 microg). Of these, 207 defined as nonresponders (<50% reduction in wet nights) were randomly assigned to receive either desmopressin (n=101) or placebo (n=106) nasal spray, together with conditioning alarm therapy for 8 weeks. Principal outcome measures were remission (28 continuous dry nights) and relapse (>2 wet nights in 2 weeks after having achieved remission). RESULTS: Remission rates were similar in both groups (51.5% desmopressin, 48.1% placebo; 95% CI on difference, -10%, 17%; P=.63), and relapse rates were not significantly different (13.5% vs 5.9%; 95% CI on difference, -3.7%, 19%; P=.19). Although remission rates were similar, children treated with desmopressin had significantly more dry nights during treatment than those in the placebo group. CONCLUSIONS: Desmopressin did not act synergistically with alarm treatment to achieve remission. Therefore, we infer that in partial or nonresponders, desmopressin does not enhance learning. 相似文献
88.
DL?MagerEmail author AD?Haffajee PM?Devlin CM?Norris MR?Posner JM?Goodson 《Journal of translational medicine》2005,3(1):27
Background
The purpose of the present investigation was to determine if the salivary counts of 40 common oral bacteria in subjects with an oral squamous cell carcinoma (OSCC) lesion would differ from those found in cancer-free (OSCC-free) controls. 相似文献89.
Z Kibar S Salem CM Bosoi E Pauwels P De Marco E Merello AG Bassuk V Capra P Gros 《Clinical genetics》2011,80(1):76-82
Kibar Z, Salem S, Bosoi CM, Pauwels E, De Marco P, Merello E, Bassuk AG, Capra V, Gros P. Contribution of VANGL2 mutations to isolated neural tube defects. Vangl2 was identified as the gene defective in the Looptail (Lp) mouse model for neural tube defects (NTDs). This gene forms part of the planar cell polarity (PCP) pathway, also called the non‐canonical Frizzled/Dishevelled pathway, which mediates the morphogenetic process of convergent extension essential for proper gastrulation and neural tube formation in vertebrates. Genetic defects in PCP signaling have strongly been associated with NTDs in mouse models. To assess the role of VANGL2 in the complex etiology of NTDs in humans, we resequenced this gene in a large multi‐ethnic cohort of 673 familial and sporadic NTD patients, including 453 open spina bifida and 202 closed spinal NTD cases. Six novel rare missense mutations were identified in seven patients, five of which were affected with closed spinal NTDs. This suggests that VANGL2 mutations may predispose to NTDs in approximately 2.5% of closed spinal NTDs (5 in 202), at a frequency that is significantly different from that of 0.4% (2 in 453) detected in open spina bifida patients (p = 0.027). Our findings strongly implicate VANGL2 in the genetic causation of spinal NTDs in a subset of patients and provide additional evidence for a pathogenic role of PCP signaling in these malformations. 相似文献
90.
A systems analysis of the chemosensitivity of breast cancer cells to the polyamine analogue PG-11047
Wen-Lin Kuo Debopriya Das Safiyyah Ziyad Sanchita Bhattacharya William J Gibb Laura M Heiser Anguraj Sadanandam Gerald V Fontenay Zhi Hu Nicholas J Wang Nora Bayani Heidi S Feiler Richard M Neve Andrew J Wyrobek Paul T Spellman Laurence J Marton Joe W Gray 《BMC medicine》2009,7(1):1-11