全文获取类型
收费全文 | 5778篇 |
免费 | 412篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 193篇 |
妇产科学 | 102篇 |
基础医学 | 691篇 |
口腔科学 | 141篇 |
临床医学 | 438篇 |
内科学 | 1446篇 |
皮肤病学 | 63篇 |
神经病学 | 230篇 |
特种医学 | 97篇 |
外国民族医学 | 1篇 |
外科学 | 597篇 |
综合类 | 358篇 |
一般理论 | 2篇 |
预防医学 | 747篇 |
眼科学 | 139篇 |
药学 | 532篇 |
中国医学 | 65篇 |
肿瘤学 | 334篇 |
出版年
2023年 | 45篇 |
2022年 | 131篇 |
2021年 | 267篇 |
2020年 | 133篇 |
2019年 | 185篇 |
2018年 | 161篇 |
2017年 | 142篇 |
2016年 | 154篇 |
2015年 | 169篇 |
2014年 | 211篇 |
2013年 | 268篇 |
2012年 | 499篇 |
2011年 | 433篇 |
2010年 | 239篇 |
2009年 | 206篇 |
2008年 | 321篇 |
2007年 | 308篇 |
2006年 | 296篇 |
2005年 | 294篇 |
2004年 | 236篇 |
2003年 | 228篇 |
2002年 | 174篇 |
2001年 | 137篇 |
2000年 | 122篇 |
1999年 | 113篇 |
1998年 | 45篇 |
1997年 | 37篇 |
1996年 | 36篇 |
1995年 | 29篇 |
1994年 | 15篇 |
1993年 | 22篇 |
1992年 | 63篇 |
1991年 | 50篇 |
1990年 | 38篇 |
1989年 | 53篇 |
1988年 | 33篇 |
1987年 | 25篇 |
1986年 | 38篇 |
1985年 | 35篇 |
1984年 | 26篇 |
1983年 | 19篇 |
1982年 | 15篇 |
1981年 | 12篇 |
1979年 | 22篇 |
1978年 | 11篇 |
1977年 | 11篇 |
1975年 | 13篇 |
1973年 | 16篇 |
1972年 | 12篇 |
1970年 | 11篇 |
排序方式: 共有6213条查询结果,搜索用时 377 毫秒
101.
102.
103.
Xiao-Qin Li Ya-Nan Song Su-Juan Wang Khalid Rahman 《Journal of Asian natural products research》2018,20(5):399-411
Over the past decades, a number of phytochemicals have been reported to possess potent pharmacological effects. Saikosaponins represent a group of oleanane derivatives, usually as glucosides, which are commonly found in medicinal plants Bupleurum spp., which have been used as traditional Chinese medicine for more than 1,000 years in China. Emerging evidence suggests that saikosaponins have many pharmacological effects, including sedation, anticonvulsant, antipyretic, antiviral, immunity, anti-inflammation, antitumor properties, protecting liver and kidney and so on. The present review provides a comprehensive summary and analysis of the pharmacological properties of saikosaponins, supporting the potential uses of saikosaponins as a medicinal agent. 相似文献
104.
105.
106.
107.
Nurul Absar M. Mashiur Rahman Masud Kamal Naziba Siddique Mantazul Islam Chowdhury 《Journal of radiation research》2014,55(6):1075-1080
Radioactivity in the soil of a tea garden in the Fatickchari area in Chittagong, Bangladesh, was measured using a high-resolution HPGe detector. The soil samples were collected from depths of up to 20 cm beneath the soil surface. The activity concentrations of naturally occurring 238U and 232Th were observed to be in the range of 27 ± 7 to 53 ± 8 Bq kg−1 and 36 ± 11 to 72 ± 11 Bq kg−1, respectively. The activity concentration of 40K ranged from 201 ± 78 to 672 ± 81 Bq kg−1, and the highest activity of fallout 137Cs observed was 10 ± 1 Bq kg−1. The average activity concentration observed for 238U was 39 ± 8 Bq kg−1, for 232Th was 57 ± 11 Bq kg−1, for 40K was 384 ± 79 Bq kg−1 and for 137Cs was 5 ± 0.5 Bq kg−1. The radiological hazard parameters (representative level index, radium equivalent activity, outdoor and indoor dose rates, outdoor and indoor annual effective dose equivalents, and radiation hazard index) were calculated from the radioactivity in the soil. 相似文献
108.
Epigenome‐wide DNA methylation changes with development of arsenic‐induced skin lesions in Bangladesh: A case–control follow‐up study
下载免费PDF全文
![点击此处可从《Environmental and molecular mutagenesis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Wei Jie Seow Molly L. Kile Andrea A. Baccarelli Wen‐Chi Pan Hyang‐Min Byun Golam Mostofa Quazi Quamruzzaman Mahmuder Rahman Xihong Lin David C. Christiani 《Environmental and molecular mutagenesis》2014,55(6):449-456
Studies have found an association between aberrant DNA methylation and arsenic‐induced skin lesions. However, little is known about DNA methylation changes over time in people who develop arsenic‐induced skin lesions. We sought to investigate epigenome‐wide changes of DNA methylation in people who developed arsenic‐induced skin lesions in a 10‐year period. In 2009–2011, we conducted a follow‐up study of 900 skin lesion cases and 900 controls and identified 10 people who developed skin lesions since a baseline survey in 2001–2003. The 10 cases (“New Cases”) were matched with 10 controls who did not have skin lesions at baseline or follow‐up (“Persistent Controls”). Drinking water and blood samples were collected, and skin lesion was diagnosed by the same physician at both time points. We measured DNA methylation in blood using Infinium HumanMethylation450K BeadChip, followed by quantitative validation using pyrosequencing. Two‐sample t‐tests were used to compare changes in percent methylation between New Cases and Persistent Controls. Six CpG (cytosine‐phosphate‐guanine) sites with greatest changes of DNA methylation over time among New Cases were further validated with a correlation of 93% using pyrosequencing. One of the validated CpG site (cg03333116; change of %methylation was 13.2 in New Cases versus ?0.09 in Persistent Controls; P < 0.001) belonged to the RHBDF1 gene, which was previously reported to be hypermethylated in arsenic‐exposed cases. We examined DNA methylation changes with the development of arsenic‐induced skin lesions over time but nothing was statistically significant given the small sample size of this exploratory study and the high dimensionality of data. Environ. Mol. Mutagen. 55:449–456, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
109.
Abdel Raouf Abou El Azm Lobna Abou-Ali Abdel Rahman Kobtan Nagwa Mansour Salwa Tawfik 《Archives of virology》2013,158(3):543-547
Hepatitis C and brucellosis are infectious diseases that occur worldwide, and both are endemic in Egypt. Co-infection with both agents is possible, and this can involve the liver in various ways. In this study, we investigated serum tissue inhibitor metalloproteinase-1 (TIMP-1), viral load, and liver functions in patients co-infected with hepatitis C virus (HCV) before and after brucellosis treatment. Over 3 years, 241 consecutive HCV patients (before interferon therapy was received) with recurrent fever who had occupational contact with animals were tested for brucellosis co-infection by a standard tube agglutination test. In patients with dual infection, viraemia (RT-PCR), TIMP-1 measured by ELISA, and liver functions were assessed and re-evaluated 2 months after brucellosis treatment. The number of patients with HCV/brucellosis co-infection was 32 out of 241 (13.3%). TIMP-1, viraemia, AST, ALT and bilirubin showed significant decrease (improvement) after brucellosis treatment (p < 0.001) but an insignificant difference (p > 0.05) with regard to serum albumin and prothrombin concentration. The study revealed that brucellosis is an important infection in HCV-infected patients and can aggravate the course of disease, suggesting that early treatment and prevention are important. 相似文献
110.
Hoi-Poh Tee Crispin Corte Hamdan Al-Ghamdi Emilia Prakoso John Darke Raman Chettiar Wassim Rahman Scott Davison Sean P Griffin Warwick S Selby Arthur J Kaffes 《World journal of gastroenterology : WJG》2010,16(31):3905-3910
AIM: To study the significance of cap-fitted colonoscopy in improving cecal intubation time and polyp detection rate. METHODS: This study was a prospective randomized controlled trial conducted from March 2008 to February 2009 in a tertiary referral hospital at Sydney. The primary end point was cecal intubation time and the secondary endpoint was polyp detection rate. Consecutive cases of total colonoscopy over a 1-year period were recruited. Randomization into either standard colonoscopy (SC) or cap-assist... 相似文献