全文获取类型
收费全文 | 1249篇 |
免费 | 120篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 91篇 |
妇产科学 | 43篇 |
基础医学 | 150篇 |
口腔科学 | 36篇 |
临床医学 | 192篇 |
内科学 | 271篇 |
皮肤病学 | 33篇 |
神经病学 | 53篇 |
特种医学 | 167篇 |
外科学 | 97篇 |
综合类 | 28篇 |
预防医学 | 82篇 |
眼科学 | 12篇 |
药学 | 69篇 |
1篇 | |
中国医学 | 9篇 |
肿瘤学 | 75篇 |
出版年
2023年 | 4篇 |
2021年 | 10篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 23篇 |
2017年 | 23篇 |
2016年 | 26篇 |
2015年 | 30篇 |
2014年 | 39篇 |
2013年 | 47篇 |
2012年 | 22篇 |
2011年 | 35篇 |
2010年 | 45篇 |
2009年 | 71篇 |
2008年 | 39篇 |
2007年 | 55篇 |
2006年 | 30篇 |
2005年 | 40篇 |
2004年 | 28篇 |
2003年 | 27篇 |
2002年 | 24篇 |
2001年 | 39篇 |
2000年 | 30篇 |
1999年 | 40篇 |
1998年 | 79篇 |
1997年 | 86篇 |
1996年 | 60篇 |
1995年 | 55篇 |
1994年 | 37篇 |
1993年 | 44篇 |
1992年 | 21篇 |
1991年 | 14篇 |
1990年 | 20篇 |
1989年 | 31篇 |
1988年 | 25篇 |
1987年 | 32篇 |
1986年 | 18篇 |
1985年 | 21篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1978年 | 9篇 |
1977年 | 11篇 |
1976年 | 7篇 |
1938年 | 3篇 |
1936年 | 3篇 |
1935年 | 3篇 |
1934年 | 3篇 |
排序方式: 共有1415条查询结果,搜索用时 31 毫秒
61.
62.
Genetic and non‐genetic factors that increase the risk of non‐syndromic cleft lip and/or palate development 下载免费PDF全文
63.
The midwifery art has emphasised the uniqueness of human beings throughout its Nordic history. The educated Nordic midwife has in the last decade celebrated several hundred years of memories. This article studies how the key ideas of the midwifery art and patterns of ideas become evident in the zeitgeist from the beginning of the 19th century to the millennium in the Nordic countries. The legacy and pattern of ideas of the art of midwifery are interpreted in relation to the texts of the selected historical sources and based on Ricoeur's phenomenological-hermeneutic approach to the text and further to the dedication of understanding and interpretation. The historical sources refer to unprinted primary sources from historical archives and printed secondary and tertiary sources. The patterns of ideas include a tripartite whole: the true cultivation of the head, the philosophy and aesthetics of the hand, the strength of the heart and the drive of calling. These ideas open for unique visions and attest to the evident in modern midwives. Today's midwives have academic training with examinations, and the education is based on scientific evidence. The midwife profession is authorised by the state and supervised by the authorities. 相似文献
64.
Michal Stein Shelly Lipman-Arens Kfir Oved Asi Cohen Ellen Bamberger Roy Navon Olga Boico Tom Friedman Liat Etshtein Meital Paz Tanya M. Gottlieb Or Kriger Yura Fonar Ester Pri-Or Renata Yacobov Yaniv Dotan Amit Hochberg Moti Grupper Adi Klein 《Diagnostic microbiology and infectious disease》2018,90(3):206-213
Bacterial and viral lower respiratory tract infections (LRTIs) are often clinically indistinguishable, leading to antibiotic overuse. We compared the diagnostic accuracy of a new assay that combines 3 host-biomarkers (TRAIL, IP-10, CRP) with parameters in routine use to distinguish bacterial from viral LRTIs. Study cohort included 184 potentially eligible pediatric and adult patients. Reference standard diagnosis was based on adjudication by an expert panel following comprehensive clinical and laboratory investigation (including respiratory PCRs). Experts were blinded to assay results and assay performers were blinded to reference standard outcomes. Evaluated cohort included 88 bacterial and 36 viral patients (23 did not fulfill inclusion criteria; 37 had indeterminate reference standard outcome). Assay distinguished bacterial from viral LRTI patients with sensitivity of 0.93 ± 0.06 and specificity of 0.91 ± 0.09, outperforming routine parameters, including WBC, CRP and chest x-ray signs. These findings support the assay's potential to help clinicians avoid missing bacterial LRTIs or overusing antibiotics. 相似文献
65.
66.
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
67.
Transcatheter closure of patent ductus arteriosus using the AMPLATZER™ duct occluder II (ADO II) 下载免费PDF全文
68.
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
69.
Briese J Schulte HM Sajin M Bamberger C Redlin K Milde-Langosch K Löning T Bamberger AM 《Virchows Archiv : an international journal of pathology》2008,453(1):121-96
Kangai (KAI)-1 (CD82) is a metastasis suppressor gene, which belongs to the family of tetraspanin proteins. A loss of KAI-1 expression is associated with the advanced stages of many human malignancies. The present study was designed to investigate the expression pattern of KAI-1 in the normal endometrium and uterine tumors and to correlate it with the expression of tumor suppressor protein p53. KAI-1 could be found in the normal endometrium throughout the menstrual cycle. Thirteen of 42 endometrial carcinomas demonstrated moderate KAI-1 expression, but low expression of p53. Twenty-nine of 42 endometrial carcinomas showed reduced or absent KAI-1 expression, which correlated with strong expression of p53 (p < 0.001). There were significant correlations between KAI-1 expression and histological type, e.g., 93% of endometrioid carcinomas displayed a low or moderate immunostaining for KAI-1, whereas nearly all of the serous/clear cell carcinomas were KAI-1 negative (p < 0.001); tumor grading, e.g., 73% of high grade tumors showed no KAI-1 expression (p < 0.001). Most of the investigated uterine sarcomas were negative for KAI-1, whereas they displayed a strong immunostaining for p53. In conclusion, KAI-1 and p53 show inverse expression. The reduced KAI-1 expression may be the result of dysregulated p53 function and could be an important step in the endometrial carcinogenesis. 相似文献
70.