全文获取类型
收费全文 | 33977篇 |
免费 | 5897篇 |
国内免费 | 100篇 |
专业分类
耳鼻咽喉 | 371篇 |
儿科学 | 930篇 |
妇产科学 | 1893篇 |
基础医学 | 2324篇 |
口腔科学 | 521篇 |
临床医学 | 16865篇 |
内科学 | 4771篇 |
皮肤病学 | 413篇 |
神经病学 | 1852篇 |
特种医学 | 748篇 |
外科学 | 3032篇 |
综合类 | 155篇 |
一般理论 | 14篇 |
预防医学 | 2755篇 |
眼科学 | 570篇 |
药学 | 1166篇 |
1篇 | |
中国医学 | 44篇 |
肿瘤学 | 1549篇 |
出版年
2023年 | 852篇 |
2022年 | 205篇 |
2021年 | 555篇 |
2020年 | 802篇 |
2019年 | 505篇 |
2018年 | 1435篇 |
2017年 | 1617篇 |
2016年 | 1725篇 |
2015年 | 1804篇 |
2014年 | 1905篇 |
2013年 | 2345篇 |
2012年 | 1227篇 |
2011年 | 1602篇 |
2010年 | 1514篇 |
2009年 | 1802篇 |
2008年 | 1420篇 |
2007年 | 1412篇 |
2006年 | 1336篇 |
2005年 | 1222篇 |
2004年 | 1101篇 |
2003年 | 1033篇 |
2002年 | 836篇 |
2001年 | 914篇 |
2000年 | 660篇 |
1999年 | 774篇 |
1998年 | 751篇 |
1997年 | 807篇 |
1996年 | 764篇 |
1995年 | 664篇 |
1994年 | 502篇 |
1993年 | 392篇 |
1992年 | 426篇 |
1991年 | 408篇 |
1990年 | 408篇 |
1989年 | 366篇 |
1988年 | 280篇 |
1987年 | 260篇 |
1986年 | 239篇 |
1985年 | 262篇 |
1984年 | 197篇 |
1983年 | 182篇 |
1982年 | 142篇 |
1981年 | 143篇 |
1980年 | 110篇 |
1979年 | 165篇 |
1978年 | 131篇 |
1977年 | 145篇 |
1976年 | 113篇 |
1975年 | 95篇 |
1972年 | 163篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
Fluid role boundaries: exploring the contribution of the advanced nurse practitioner to multi‐professional palliative care 下载免费PDF全文
44.
Der Freie Zahnarzt - 相似文献
45.
Maria Ricci Agostino Chiaravalloti Alessandro Martorana Giacomo Koch Vincenzo De lucia Gaetano Barbagallo Orazio Schillaci 《Annals of nuclear medicine》2020,34(4):254-262
The aim of our study was to investigate the impact of the epsilon phenotype in brain glucose consumption in a population with Alzheimer’s disease. Statistical Parametric Mapping (SPM8) was used to investigate differences in brain glucose consumption (as detectable by means of 18F FDG-PET/CT) in the population examined. A total of 129 patients (72 females and 57 males) with a diagnosis of probable AD according to the NINCDS-ADRDA criteria underwent the PET/CT examination. The mean (SD) age of the patients was 70 (± 7) years; the mean Mini-Mental State Examination was 19(± 5.6). 59 expressed epsilon 4 phenotype (E4) and 70 expressed the epsilon 3 phenotype (E3). Cerebral spinal fluid amyloid, tau, and t-tau have been measured resulting equal to 367.4 (± 149.1), 584.7 (± 312.1), and 79.2(± 45.9) pg/ml, respectively. Patients with confirmed amyloid and Tau changes were classified as AD. Patients with amyloid changes but negative Tau, considered as high risk of AD, were classified as IAD. Age, sex, MMSE, scholarship, and CSF parameters were used as a covariate in the SPM analyses. We did not find significant differences in age, gender, and MMSE and CSF parameters among groups. In the analysis of the AD group as compared to AD-E3, AD-E4 subjects show a significant reduction of brain glucose consumption in inferior frontal gyrus bilaterally (BA 45, BA 47). In the analysis of the IAD group as compared to IAD-E3, IAD-E4 subjects show a significant reduction of brain glucose consumption in right in medial, middle, and superior frontal gyrus (BA10, BA11), and in left medial and middle frontal gyrus (BA10, BA11). The differences between IAD-E3 and AD-E3 and between IAD-E4 and AD-E4 (and vice versa analysis) resulted not significant. APO-e4 is related to a major involvement of the frontal cortex confirming its role of risk factor in AD, while APO-3 seems not related to a specific pattern, supporting the hypothesis of neutral/protective role in AD. 相似文献
46.
47.
48.
49.
50.
Ming-Yeh Yang Ching-Yuan Huang Tina H.T. Chiu Kai-Chih Chang Ming-Nan Lin Liang-Yü Chen Anren Hu 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2019,27(2):494-501
Vitamin D is responsible for multiple metabolic functions in humans. Rickets are the most common disease caused by vitamin D deficiency. It is caused by poor calcium intake resulting in poor serum-ionized calcium. The purpose of this study is to develop a rapid, sensitive, and feasible method to determine the 25-hydroxy-vitamin D3 (25(OH)D3) levels in blood samples for clinical assessment. In this study, gas chromatography coupled mass spectrometry with trimethylsilyl derivatization (TMS-GC-MS) is the most suitable protocol for quantitative analyses of 25(OH)D3. Performance of method was evaluated and compared with liquid chromatography and immunoassay. Method validation has been carried out with plasma specimens. The limit of quantitation of TMS-GC-MS method is 1.5 ppb with good linear correlation. Furthermore, the dietary intake and nutritional status of vegetarian and non-vegetarians in Taiwan were assessed by our validated method. As a result, this vitamin D nutrition survey demonstrates that most Taiwanese people have insufficient vitamin D. Due to dietary habits; the male vegans may have the highest risk of vitamin D deficiency. 相似文献