全文获取类型
收费全文 | 1434篇 |
免费 | 145篇 |
国内免费 | 8篇 |
专业分类
儿科学 | 50篇 |
妇产科学 | 33篇 |
基础医学 | 217篇 |
口腔科学 | 19篇 |
临床医学 | 124篇 |
内科学 | 351篇 |
皮肤病学 | 2篇 |
神经病学 | 101篇 |
特种医学 | 61篇 |
外科学 | 210篇 |
综合类 | 14篇 |
预防医学 | 115篇 |
眼科学 | 27篇 |
药学 | 134篇 |
1篇 | |
肿瘤学 | 128篇 |
出版年
2022年 | 11篇 |
2021年 | 26篇 |
2020年 | 10篇 |
2019年 | 22篇 |
2018年 | 16篇 |
2017年 | 16篇 |
2016年 | 15篇 |
2015年 | 28篇 |
2014年 | 47篇 |
2013年 | 55篇 |
2012年 | 65篇 |
2011年 | 53篇 |
2010年 | 50篇 |
2009年 | 46篇 |
2008年 | 41篇 |
2007年 | 68篇 |
2006年 | 57篇 |
2005年 | 70篇 |
2004年 | 76篇 |
2003年 | 75篇 |
2002年 | 62篇 |
2001年 | 56篇 |
2000年 | 44篇 |
1999年 | 33篇 |
1998年 | 30篇 |
1997年 | 27篇 |
1996年 | 32篇 |
1995年 | 36篇 |
1994年 | 27篇 |
1993年 | 22篇 |
1992年 | 21篇 |
1991年 | 26篇 |
1990年 | 21篇 |
1989年 | 32篇 |
1988年 | 26篇 |
1987年 | 23篇 |
1986年 | 15篇 |
1985年 | 26篇 |
1984年 | 18篇 |
1983年 | 17篇 |
1982年 | 12篇 |
1981年 | 14篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1978年 | 12篇 |
1977年 | 13篇 |
1976年 | 8篇 |
1972年 | 10篇 |
1969年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有1587条查询结果,搜索用时 15 毫秒
991.
Bradbury RA Cropley J Kifor O Lovicu FJ de Iongh RU Kable E Brown EM Seely EW Peat BB Conigrave AD 《Placenta》2002,23(2-3):192-200
We have demonstrated using immunohistochemistry and in situ hybridization that the calcium-sensing receptor (CaR) is expressed in both villous and extravillous regions of the human placenta. CaR expression was detected in both first trimester and term placentas. In the villous region of the placenta, the CaR was detected in syncytiotrophoblasts and at lower levels in cytotrophoblasts. Local expression of the CaR in the brush border of syncytiotrophoblasts suggests a role for maternal Ca(2+) concentration in the control of transepithelial transport between the mother and fetus. In the extravillous region of the placenta, the CaR was detected in cells forming trophoblast columns in anchoring villi, in close proximity to maternal blood vessels and in transitional cytotrophoblasts. Given the importance of extravillous cytotrophoblasts in the process of uterine invasion and maintenance of placental immune privilege, the CaR represents a possible target by which the maternal extracellular Ca(2+) concentration could promote or maintain placentation. Thus, the results support hypotheses that the CaR contributes to the local control of transplacental calcium transport and to the regulation of placental development. 相似文献
992.
993.
994.
995.
Reshma Jagsi Rebecca Spence W. Kimryn Rathmell Angela Bradbury Jeffrey Peppercorn Stephen Grubbs Beverly Moy 《The oncologist》2014,19(2):186-192
Shortages of injectable drugs affect many cancer patients and providers in the U.S. today. Scholars and policymakers have recently begun to devote increased attention to these issues, but only a few tangible resources exist to guide clinical oncologists in developing strategies for dealing with drug shortages on a recurring basis. This article discusses existing information from the scholarly literature, policy analyses, and other relevant sources and seeks to provide practical ethical guidance to the broad audience of oncology professionals who are increasingly confronted with such cases in their practice. We begin by providing a brief overview of the history, causes, and regulatory context of oncology drug shortages in the U.S., followed by a discussion of ethical frameworks that have been proposed in this setting. We conclude with practical recommendations for ethical professional behavior in these increasingly common and challenging situations. 相似文献
996.
997.
Helicobacter pylori infection,chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case‐control study
下载免费PDF全文
![点击此处可从《International journal of cancer. Journal international du cancer》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jiaqi Huang Ulrika Zagai Göran Hallmans Olof Nyrén Lars Engstrand Rachael Stolzenberg‐Solomon Eric J Duell Kim Overvad Verena A Katzke Rudolf Kaaks Mazda Jenab Jin Young Park Raul Murillo Antonia Trichopoulou Pagona Lagiou Christina Bamia Kathryn E Bradbury Elio Riboli Dagfinn Aune Konstantinos K Tsilidis Gabriel Capellá Antonio Agudo Vittorio Krogh Domenico Palli Salvatore Panico Elisabete Weiderpass Anne Tjønneland Anja Olsen Begoña Martínez Daniel Redondo‐Sanchez Maria‐Dolores Chirlaque Petra HM Peeters Sara Regnér Björn Lindkvist Alessio Naccarati Eva Ardanaz Nerea Larrañaga Marie‐Christine Boutron‐Ruault Vinciane Rebours Amélie Barré Weimin Ye 《International journal of cancer. Journal international du cancer》2017,140(8):1727-1735
The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case‐control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non‐significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction < 0.01). Our findings provided evidence supporting the null association between H. pylori infection and pancreatic cancer risk in western European populations. However, the suggested association between chronic corpus atrophic gastritis and pancreatic cancer risk warrants independent verification in future studies, and, if confirmed, further studies on the underlying mechanisms. 相似文献
998.
999.