全文获取类型
收费全文 | 36476篇 |
免费 | 3616篇 |
国内免费 | 2422篇 |
专业分类
耳鼻咽喉 | 260篇 |
儿科学 | 820篇 |
妇产科学 | 346篇 |
基础医学 | 2906篇 |
口腔科学 | 548篇 |
临床医学 | 5400篇 |
内科学 | 4162篇 |
皮肤病学 | 481篇 |
神经病学 | 1503篇 |
特种医学 | 1152篇 |
外国民族医学 | 7篇 |
外科学 | 2441篇 |
综合类 | 8321篇 |
现状与发展 | 6篇 |
一般理论 | 4篇 |
预防医学 | 3832篇 |
眼科学 | 854篇 |
药学 | 4604篇 |
45篇 | |
中国医学 | 2636篇 |
肿瘤学 | 2186篇 |
出版年
2024年 | 112篇 |
2023年 | 466篇 |
2022年 | 1131篇 |
2021年 | 1497篇 |
2020年 | 1289篇 |
2019年 | 953篇 |
2018年 | 984篇 |
2017年 | 1142篇 |
2016年 | 955篇 |
2015年 | 1545篇 |
2014年 | 2143篇 |
2013年 | 2179篇 |
2012年 | 3145篇 |
2011年 | 3364篇 |
2010年 | 2602篇 |
2009年 | 2293篇 |
2008年 | 2517篇 |
2007年 | 2507篇 |
2006年 | 2303篇 |
2005年 | 1904篇 |
2004年 | 1459篇 |
2003年 | 1369篇 |
2002年 | 1075篇 |
2001年 | 906篇 |
2000年 | 715篇 |
1999年 | 484篇 |
1998年 | 266篇 |
1997年 | 253篇 |
1996年 | 172篇 |
1995年 | 138篇 |
1994年 | 131篇 |
1993年 | 68篇 |
1992年 | 83篇 |
1991年 | 49篇 |
1990年 | 42篇 |
1989年 | 47篇 |
1988年 | 28篇 |
1987年 | 33篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1975年 | 8篇 |
1974年 | 5篇 |
1973年 | 8篇 |
1970年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
Mutation analysis of tubulin beta 8 class VIII in infertile females with oocyte or embryonic defects
Ping Yang Changjian Yin Mei Li Shuiying Ma Yongzhi Cao Changming Zhang Tailai Chen Han Zhao 《Clinical genetics》2021,99(1):208-214
Variants of tubulin beta 8 class VIII (TUBB8) have been shown to be associated with female infertility characterized by oocyte or embryonic defects. To further investigate the mutational spectrum of TUBB8 and the prevalence of variants, we performed Sanger sequencing of TUBB8 on a total of 115 infertile females who had undergone repeated in vitro fertilization cycles with oocyte or embryonic defects and 200 healthy controls. A total of 31 variants which were absent from the controls were identified in 36 unrelated individuals, accounting for a large proportion of this cohort (31.3%). All of the variants including heterozygous/homozygous missense variants and a heterozygous frameshift insertion variant were at conserved sites and predicted to be deleterious. Besides, these variants had diverse phenotypic effects, including not only oocyte maturation arrest, fertilization failure, and early embryonic arrest, but also multi‐pronuclei (MPN) formation, which is a new phenotype associated with TUBB8 variants. Overall, this study reveals a large number of variants of the TUBB8 gene in infertile females with oocyte or embryonic defects. Our results not only broaden the mutational and phenotypic spectra of TUBB8 variants, but also further confirm the critical role of TUBB8 in oocyte maturation, fertilization, and early embryonic development. 相似文献
993.
Ya-dong Gao Mei Ding Xiang Dong Jin-jin Zhang Ahmet Kursat Azkur Dilek Azkur Hui Gan Yuan-li Sun Wei Fu Wei Li Hui-ling Liang Yi-yuan Cao Qi Yan Can Cao Hong-yu Gao Marie-Charlotte Brüggen Willem van de Veen Milena Sokolowska Mübeccel Akdis Cezmi A. Akdis 《Allergy》2021,76(2):428-455
The pandemic of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused an unprecedented global social and economic impact, and high numbers of deaths. Many risk factors have been identified in the progression of COVID-19 into a severe and critical stage, including old age, male gender, underlying comorbidities such as hypertension, diabetes, obesity, chronic lung diseases, heart, liver and kidney diseases, tumors, clinically apparent immunodeficiencies, local immunodeficiencies, such as early type I interferon secretion capacity, and pregnancy. Possible complications include acute kidney injury, coagulation disorders, thoromboembolism. The development of lymphopenia and eosinopenia are laboratory indicators of COVID-19. Laboratory parameters to monitor disease progression include lactate dehydrogenase, procalcitonin, high-sensitivity C-reactive protein, proinflammatory cytokines such as interleukin (IL)-6, IL-1β, Krebs von den Lungen-6 (KL-6), and ferritin. The development of a cytokine storm and extensive chest computed tomography imaging patterns are indicators of a severe disease. In addition, socioeconomic status, diet, lifestyle, geographical differences, ethnicity, exposed viral load, day of initiation of treatment, and quality of health care have been reported to influence individual outcomes. In this review, we highlight the scientific evidence on the risk factors of severity of COVID-19. 相似文献
994.
Over 1 million hematopoietic stem cell transplants (HSCTs) have been performed during the last 50 years, with the number of transplants and clinical indications expected to continue to increase. Although advances in the field have improved outcomes of HSCT, it still carries a high risk due to the immunocompromised state of HSCT recipients. Multiple steps are involved from the initial collection of donor hematopoietic progenitor cells to the final infusion of the cellular product in a recipient. This review focuses on the infectious risk associated with each of these steps, as well as infectious disease testing strategies that can be used to mitigate these risks and to ensure a safe HSCT procedure. 相似文献
995.
为调查和分析云南西南部山地农耕区蚤类物种多样性空间分布格局、特征及其与人间鼠疫的关系,本文以云南西南部家鼠鼠疫疫源地中的耿马、临沧、陇川、龙陵、盈江、梁河、腾冲和云龙8县市为调查研究的空间范围,对各县市多个乡镇农耕区进行小型兽类及寄生蚤类的调查取样,所获蚤类数据进行群落组织水平的测定和统计学处理,就当地蚤类物种多样性空间分布格局与人间鼠疫之间的关系进行分析和探讨.结果 显示,(1)共捕获小型兽类2890只,隶属于7科19属35种;共采集宿主寄生蚤类2840只,隶属于6科16属27种.其中,印鼠客蚤(44.26%)和缓慢细蚤(20.39%)为数量上的优势种,偏远古蚤(8.56%)、长形病蚤(7.71%)和泸水栉眼蚤(6.76%)3蚤种数量相对较多,为当地的优势种,而其余的蚤种数量都相对较少;(2)蚤类水平分布和海拔分布的聚类分析结果显示均可聚为3类,它们整体反映了各调查样区或取样地点的地理位置、海拔高度和气候环境条件对农耕区蚤类群落和物种的组成、分布具有重要影响;(3)蚤类的Cody指数(β-多样性)沿海拔梯度的增加呈先逐步降低,后再升高的趋势,Sorenson指数随海拔增高呈先升高后降低的单峰分布格局,它们整体反映了滇西南山地农耕区蚤类群落和物种的组成与区系分布在2000~2500 m较高海拔的区域间发生了较大的变化;(4)蚤类的物种丰富度(γ-多样性)沿海拔梯度带变化规律总体呈现了随海拔升高呈先增高后降低的偏单峰分布格局,最大峰值出现在海拔1500~2000 m间,即在云南3类不同气候温层农耕区中,以中暖层气候农耕区蚤类物种丰富度最高;(5)蚤类的物种多样性指数(α-多样性)以腾冲市最高(1.9178),其他依次为梁河(1.6425)、云龙(1.6391)、陇川(1.5071)、龙陵(1.4948)、盈江(1.4778)、临沧(0.9402),而最低为耿马(0.2753);(6)蚤类的物种多样性、丰富度、均匀度、生态优势度和总蚤指数与人间鼠疫病例构成比之间的相关分析结果显示:物种多样性、均匀度与人间鼠疫均呈显著负相关,而生态优势度与人间鼠疫呈显著正相关;但总蚤指数与物种多样性、均匀度、生态优势度、物种丰富度和病例构成比均不相关.结果 表明,在蚤类物种多样性、均匀度高而生态优势度较低的区域,人间鼠疫发生率较低或未发生鼠疫,反之,人间鼠疫的发生率则较高;(7)优势种印鼠客蚤物种多度及其空间分布特征与人间鼠疫的发生与否和流行强度之间都具有重要关系.结果 表明滇西南家鼠鼠疫疫源地农耕区蚤类物种多样性和优势种印鼠客蚤物种多度的空间分布格局和特征与当地人间鼠疫的发生与否、流行强度都存在重要的关系. 相似文献
996.
997.
Lin Jing Wu Haicong Gu Lei Wu Xia Su Miaofang Lin Haiyan Liu Bang Zheng Jiaolong Mei Xuan Li Dongliang 《Clinical and experimental medicine》2021,21(3):369-377
Clinical and Experimental Medicine - Chronic active Epstein–Barr virus (CAEBV) infection is a rare disease with a high mortality rate. Our study aimed to summarize the clinicopathological... 相似文献
998.
999.
1000.
目的研究流动剪应力对丹酚酸B抑制血小板聚集的影响及其可能的机制。方法采用生物力药理学的研究方法,2×4析因设计分组,利用BioFlux 1000控剪应力微流培养系统,分别施以0.02、1.5 Pa剪应力并联合4个剂量的丹酚酸B对血管内皮细胞(HUVECs)进行预处理20 h,收集上清液,采用联酶免疫吸附法(ELISA)检测细胞上清液中6-keto-PGF1α和vWF含量;检测上清液对ADP诱导的血小板聚集的影响;免疫荧光法分析流动内皮细胞胞浆vWF含量。结果与低剪应力流动条件相比,1.5 Pa剪应力联合100μg/mL丹酚酸B能显著提高内皮细胞分泌6-keto-PGF1α的量(P<0.05);细胞上清液明显抑制了血小板聚集(P<0.05)。剪应力的变化显著影响血管内皮细胞释放vWF(P<0.01),而丹酚酸B对血管内皮细胞释放vWF无明显影响。结论丹酚酸B可能通过促进血管内皮细胞分泌PGI2发挥抗血小板聚集的效应。从血流/血管/血液相互作用的角度看,正常的流动剪应力是丹酚酸B发挥抗血小板聚集效应的有利条件之一。 相似文献