全文获取类型
收费全文 | 1475194篇 |
免费 | 126678篇 |
国内免费 | 14400篇 |
专业分类
耳鼻咽喉 | 17869篇 |
儿科学 | 44977篇 |
妇产科学 | 39205篇 |
基础医学 | 200119篇 |
口腔科学 | 38802篇 |
临床医学 | 138552篇 |
内科学 | 301190篇 |
皮肤病学 | 33458篇 |
神经病学 | 119053篇 |
特种医学 | 60423篇 |
外国民族医学 | 345篇 |
外科学 | 225032篇 |
综合类 | 50730篇 |
现状与发展 | 26篇 |
一般理论 | 441篇 |
预防医学 | 115941篇 |
眼科学 | 32119篇 |
药学 | 107340篇 |
122篇 | |
中国医学 | 8260篇 |
肿瘤学 | 82268篇 |
出版年
2021年 | 14606篇 |
2019年 | 13240篇 |
2018年 | 17685篇 |
2017年 | 14437篇 |
2016年 | 16361篇 |
2015年 | 19631篇 |
2014年 | 26665篇 |
2013年 | 36280篇 |
2012年 | 45749篇 |
2011年 | 49272篇 |
2010年 | 30677篇 |
2009年 | 28976篇 |
2008年 | 43504篇 |
2007年 | 45995篇 |
2006年 | 47195篇 |
2005年 | 45774篇 |
2004年 | 42025篇 |
2003年 | 40833篇 |
2002年 | 38231篇 |
2001年 | 69201篇 |
2000年 | 71129篇 |
1999年 | 60036篇 |
1998年 | 19092篇 |
1997年 | 17289篇 |
1996年 | 17720篇 |
1995年 | 17843篇 |
1994年 | 16475篇 |
1993年 | 15105篇 |
1992年 | 48423篇 |
1991年 | 46954篇 |
1990年 | 45044篇 |
1989年 | 42734篇 |
1988年 | 39634篇 |
1987年 | 38865篇 |
1986年 | 36484篇 |
1985年 | 35224篇 |
1984年 | 26782篇 |
1983年 | 22457篇 |
1982年 | 14096篇 |
1981年 | 12719篇 |
1979年 | 23842篇 |
1978年 | 17283篇 |
1977年 | 14569篇 |
1976年 | 13367篇 |
1975年 | 13922篇 |
1974年 | 16317篇 |
1973年 | 15556篇 |
1972年 | 14342篇 |
1971年 | 13182篇 |
1970年 | 12017篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
目的 了解我国老年人中医证候分布特征,为中医药辨治老年人提供参考依据。方法 系统检索中国知识基础设施(CNKI)、中文科技期刊数据库(CCD)、万方数据资源系统数据库(CSPD),纳入研究对象为老年人的临床流行病学调查研究文献,对其调查目的、调查疾病及调查结果等进行描述统计。结果 ①最终纳入168篇文献,其中2010至2020年之间发表138篇(82.14%);调查地区涵盖全国28个省市自治区,共纳入43948例老年人,累计覆盖340个研究中心;②主要研究结果显示,老年人中医证候阴虚阳亢证(10.05%)>血瘀证(9.5%)>痰浊(湿)证(8.91%)>阴阳两虚证(4.98%)>痰瘀互结证(4.96%);单元证分布阴虚证(14.70%)>痰证(11.22%)>气虚证(7.15%)>肾虚证(4.72%)>血瘀证(4.18%);涉及病变脏腑肾>肝>脾>肺>心。结论 根据统计结果,可以看出老年人证候分布虚证多于实证,虚证中又以阴虚证、气虚证最为多见,实证常见血瘀证、痰浊(湿)证等,且多见痰瘀互结证;老年人五脏皆损,其中又以肾、肝、脾功能失调最为突出。 相似文献
3.
Wuteng Cao Huabin Hu Jiao Li Qianyu Wu Lishuo Shi Biao Li Jie Zhou Xinhua Wang Junhong Chen Chao Wang Huaiming Wang Weihao Deng Yan Huang Yanhong Deng 《International journal of cancer. Journal international du cancer》2023,153(11):1894-1903
Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT 03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy. 相似文献
4.
5.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses... 相似文献
6.
Qian Zhang Larry D. Mesner Gina M. Calabrese Naomi Dirckx Zhu Li Angela Verardo Qian Yang Robert J. Tower Marie-Claude Faugere Charles R. Farber Thomas L. Clemens 《The Journal of clinical investigation》2021,131(7)
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass. 相似文献
7.
8.
Her-Shyong Shiah Nai-Jung Chiang Chia-Chi Lin Chia-Jui Yen Hui-Jen Tsai Shang-Yin Wu Wu-Chou Su Kwang-Yu Chang Ching-Chiung Wang Jang-Yang Chang Li-Tzong Chen 《The oncologist》2021,26(4):e567-e579
Lessons Learned
- SCB01A is a novel microtubule inhibitor with vascular disrupting activity.
- This first‐in‐human study demonstrated SCB01A safety, pharmacokinetics, and preliminary antitumor activity.
- SCB01A is safe and well tolerated in patients with advanced solid malignancies with manageable neurotoxicity.
9.
10.
Patrick W. Keeley Mikayla C. Lebo Jordan D. Vieler Jason J. Kim Ace J. St. John Benjamin E. Reese 《The Journal of neuroscience》2021,41(1):103
Amacrine cells of the retina are conspicuously variable in their morphologies, their population demographics, and their ensuing functions. Vesicular glutamate transporter 3 (VGluT3) amacrine cells are a recently characterized type of amacrine cell exhibiting local dendritic autonomy. The present analysis has examined three features of this VGluT3 population, including their density, local distribution, and dendritic spread, to discern the extent to which these are interrelated, using male and female mice. We first demonstrate that Bax-mediated cell death transforms the mosaic of VGluT3 cells from a random distribution into a regular mosaic. We subsequently examine the relationship between cell density and mosaic regularity across recombinant inbred strains of mice, finding that, although both traits vary across the strains, they exhibit minimal covariation. Other genetic determinants must therefore contribute independently to final cell number and to mosaic order. Using a conditional KO approach, we further demonstrate that Bax acts via the bipolar cell population, rather than cell-intrinsically, to control VGluT3 cell number. Finally, we consider the relationship between the dendritic arbors of single VGluT3 cells and the distribution of their homotypic neighbors. Dendritic field area was found to be independent of Voronoi domain area, while dendritic coverage of single cells was not conserved, simply increasing with the size of the dendritic field. Bax-KO retinas exhibited a threefold increase in dendritic coverage. Each cell, however, contributed less dendrites at each depth within the plexus, intermingling their processes with those of neighboring cells to approximate a constant volumetric density, yielding a uniformity in process coverage across the population.SIGNIFICANCE STATEMENT Different types of retinal neuron spread their processes across the surface of the retina to achieve a degree of dendritic coverage that is characteristic of each type. Many of these types achieve a constant coverage by varying their dendritic field area inversely with the local density of like-type neighbors. Here we report a population of retinal amacrine cells that do not develop dendritic arbors in relation to the spatial positioning of such homotypic neighbors; rather, this cell type modulates the extent of its dendritic branching when faced with a variable number of overlapping dendritic fields to approximate a uniformity in dendritic density across the retina. 相似文献