全文获取类型
收费全文 | 13711篇 |
免费 | 924篇 |
国内免费 | 383篇 |
专业分类
耳鼻咽喉 | 110篇 |
儿科学 | 270篇 |
妇产科学 | 155篇 |
基础医学 | 1416篇 |
口腔科学 | 627篇 |
临床医学 | 1291篇 |
内科学 | 2394篇 |
皮肤病学 | 217篇 |
神经病学 | 1759篇 |
特种医学 | 840篇 |
外国民族医学 | 5篇 |
外科学 | 1585篇 |
综合类 | 1820篇 |
现状与发展 | 2篇 |
预防医学 | 527篇 |
眼科学 | 163篇 |
药学 | 742篇 |
6篇 | |
中国医学 | 417篇 |
肿瘤学 | 672篇 |
出版年
2024年 | 25篇 |
2023年 | 246篇 |
2022年 | 413篇 |
2021年 | 566篇 |
2020年 | 513篇 |
2019年 | 494篇 |
2018年 | 441篇 |
2017年 | 450篇 |
2016年 | 442篇 |
2015年 | 444篇 |
2014年 | 872篇 |
2013年 | 825篇 |
2012年 | 716篇 |
2011年 | 759篇 |
2010年 | 623篇 |
2009年 | 663篇 |
2008年 | 692篇 |
2007年 | 705篇 |
2006年 | 612篇 |
2005年 | 501篇 |
2004年 | 405篇 |
2003年 | 346篇 |
2002年 | 345篇 |
2001年 | 312篇 |
2000年 | 262篇 |
1999年 | 214篇 |
1998年 | 181篇 |
1997年 | 210篇 |
1996年 | 187篇 |
1995年 | 154篇 |
1994年 | 167篇 |
1993年 | 122篇 |
1992年 | 122篇 |
1991年 | 98篇 |
1990年 | 90篇 |
1989年 | 71篇 |
1988年 | 82篇 |
1987年 | 70篇 |
1986年 | 81篇 |
1985年 | 106篇 |
1984年 | 67篇 |
1983年 | 39篇 |
1982年 | 56篇 |
1981年 | 54篇 |
1980年 | 38篇 |
1979年 | 25篇 |
1978年 | 25篇 |
1977年 | 18篇 |
1976年 | 18篇 |
1975年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
The serrated pathway (SP) can be viewed as two parallel, but partially overlapping, arrays of colorectal precursor lesions, and their respective endpoint carcinomas, that are distinct from those of the conventional adenoma–carcinoma sequence (APC‐pathway). In this review we focus at the outset on the clinical impact, pathological features, molecular genetics and biological behaviours of the various SP cancers. Then we summarize the clinicopathological features, classification and molecular profiles of the two main precursor lesions that anchor the respective pathways: (i) sessile serrated adenoma/polyp (SSA/P), also called sessile serrated lesion (SSL), and (ii) traditional serrated adenoma (TSA). Activating mutations of the RAS–RAF–MAPK pathway initiate and sustain the lesions of the SP, and CpG island methylation of the promoter regions of tumour suppressor and DNA repair genes play the major role in their neoplastic progression. The SP includes microsatellite stable (MSS) carcinomas that are among the most biologically aggressive colorectal carcinomas (CRC), and also accounts for the great preponderance of sporadic hypermutated, mismatch repair (MMR)‐deficient or microsatellite instable (MSI) CRC. The identification, removal and appropriate classification of at‐risk SP precursors and surveillance of individuals who harbour these lesions present a challenge and opportunity for CRC prevention and mortality reduction. 相似文献
4.
目的基于复杂网络技术分析电针治疗乳腺增生病的核心穴位及配伍穴相关性,并对电针波型进行探讨。方法检索中国期刊全文数据库(CNKI)、万方数据库、维普网数据库(VIP)中从1954年1月1日到2018年12月31日公开发表的电针治疗乳腺增生病的临床中文文献,利用Excel表格工具建立电针治疗乳腺增生病数据库,利用Matlab2014a软件进行节点中心性分析和聚类分析,利用Gephi0.9.1软件制作复杂网络示意图对分析结果进行描述和展示,利用Excel表格工具制作电针治疗乳腺增生病不同波形比例饼状图并分析其规律。结果选定43条电针处方:电针治疗乳腺增生病主穴核心度前三位依次为膻中穴、足三里、肩井穴;配伍穴位核心度前三位依次为太冲穴、太溪穴、脾俞穴;经络核心度前三位依次为足阳明胃经、任脉、足少阳胆经。配伍穴位相关性分析中,相关性频度前三位组合依次为太冲穴-太溪穴、太冲穴-肾俞穴、太冲穴-三阴交。电针波形中以连续波与疏密波常见,均具有较高的临床应用价值。结论电针治疗乳腺增生病处方以足阳明胃经为最多,其次为任脉;电针波型以连续波为主。 相似文献
5.
Christopher Yeh Cem Atillasoy John T. Seykora Vivian Lee 《Journal of cutaneous pathology》2021,48(1):171-173
Respiratory cysts are benign lesions lined by normal respiratory epithelium. There are few reported cases localized to the orbit, while those of the eyelid are exceedingly rare. Respiratory cysts usually arise either from a non‐hereditary congenital malformation, where they are distinguished as choristomatous, or from trauma. Here, we report a case of a 53‐year‐old man who presented with a large right lower eyelid cyst that was histopathologically diagnosed as a respiratory cyst. 相似文献
6.
7.
8.
Objectives:To reassess the long-term camouflage effects of resin infiltration (Icon, DMG, Hamburg, Germany) of white spot lesions (WSL) and sound adjacent enamel (SAE) achieved in a previous trial. The null hypothesis was tested that there were no significantly different CIE-L*a*b*-ΔE-values between WSL and SAE areas of assessment after at least 24 months (T24) compared to those at baseline (T0).Materials and Methods:Of twenty subjects who received previous resin infiltration treatment of nteeth = 111 nonrestored, noncavitated postorthodontic WSL after multibracket treatment during a randomized controlled trial and were contacted 20 months after baseline, eight subjects (trial teeth nteeth = 40; m/f ratio 1/7; age range (mean; SD) 12–17 [15.25; 2.12] years); response rate: 40%) were available for follow-up after at least 24 months (T24). CIE-L*a*b* differences between summarized color and lightness values (ΔEWSL/SAE) of WSL and SAE were assessed using a spectrophotometer and compared to baseline data assessed prior to infiltration (T0), and those after 6 (T6), and 12 (T12) months using paired t tests at a significance level of α = 5%.Results:T24 assessments were performed after a mean 33.86 (SD: 8.64; Min: 24; Max: 45) months following T0. Mean (SD) ΔEWSL/SAE units of available teeth were 8.76 (5.33) at baseline; 5.5 (2.75) at T6; 5.2 (2.41) at T12; and 5.57 (2.6) at T24. Comparisons of T6, T12, and T24 with T0 yielded highly significant differences, whereas T6–T24 and T12–T24 differences were found to be not significant.Conclusions:Assimilation of infiltrated WSL to the color of adjacent enamel by resin infiltration is considered to be suitable for the long-term improvement in the esthetic appearance of postorthodontic WSL. 相似文献
9.
《Indian journal of medical microbiology》2021,39(3):384-385
Aeromonas species can cause gastroenteritis, soft tissue infections, hepatobiliary tract and other infections. While most reported soft tissue infections have been attributed to Aeromonas hydrophila, we report a case of necrotizing fasciitis caused by Aeromonas veronii biovar sobria. Prompt and accurate diagnosis cum treatment could help save children with Aeromonas soft tissue infections from developing a bacteremia with extended morbidity and mortality. 相似文献
10.
Thomas Asendorf Robin Henderson Heinz Schmidli Tim Friede 《Statistics in medicine》2019,38(9):1503-1528
In some diseases, such as multiple sclerosis, lesion counts obtained from magnetic resonance imaging (MRI) are used as markers of disease progression. This leads to longitudinal, and typically overdispersed, count data outcomes in clinical trials. Models for such data invariably include a number of nuisance parameters, which can be difficult to specify at the planning stage, leading to considerable uncertainty in sample size specification. Consequently, blinded sample size re-estimation procedures are used, allowing for an adjustment of the sample size within an ongoing trial by estimating relevant nuisance parameters at an interim point, without compromising trial integrity. To date, the methods available for re-estimation have required an assumption that the mean count is time-constant within patients. We propose a new modeling approach that maintains the advantages of established procedures but allows for general underlying and treatment-specific time trends in the mean response. A simulation study is conducted to assess the effectiveness of blinded sample size re-estimation methods over fixed designs. Sample sizes attained through blinded sample size re-estimation procedures are shown to maintain the desired study power without inflating the Type I error rate and the procedure is demonstrated on MRI data from a recent study in multiple sclerosis. 相似文献