首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   69774篇
  免费   4381篇
  国内免费   848篇
耳鼻咽喉   1241篇
儿科学   923篇
妇产科学   1067篇
基础医学   11966篇
口腔科学   1551篇
临床医学   6087篇
内科学   13300篇
皮肤病学   2468篇
神经病学   5066篇
特种医学   3810篇
外科学   9389篇
综合类   307篇
现状与发展   1篇
一般理论   20篇
预防医学   3210篇
眼科学   1614篇
药学   6233篇
中国医学   813篇
肿瘤学   5937篇
  2023年   349篇
  2022年   1165篇
  2021年   2485篇
  2020年   1266篇
  2019年   1641篇
  2018年   2078篇
  2017年   1614篇
  2016年   2292篇
  2015年   3302篇
  2014年   3909篇
  2013年   4419篇
  2012年   6626篇
  2011年   6075篇
  2010年   3628篇
  2009年   3066篇
  2008年   4315篇
  2007年   3927篇
  2006年   3434篇
  2005年   3036篇
  2004年   2630篇
  2003年   2243篇
  2002年   1910篇
  2001年   1581篇
  2000年   1477篇
  1999年   1077篇
  1998年   460篇
  1997年   334篇
  1996年   269篇
  1995年   218篇
  1994年   180篇
  1993年   165篇
  1992年   374篇
  1991年   378篇
  1990年   314篇
  1989年   306篇
  1988年   300篇
  1987年   286篇
  1986年   207篇
  1985年   188篇
  1984年   135篇
  1983年   136篇
  1982年   65篇
  1981年   68篇
  1979年   106篇
  1978年   91篇
  1977年   68篇
  1975年   62篇
  1974年   72篇
  1973年   63篇
  1972年   59篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
991.
992.
993.
This study aimed to examine causal relationships between bicultural identity, acculturative stress, and subjective well‐being among multicultural adolescents. Secondary longitudinal data that were obtained from 1,635 multicultural adolescents were analysed. The results showed that bicultural identity had a positive effect on psychological well‐being and a negative impact on acculturative stress; in addition, greater acculturative stress was associated with lower psychological well‐being. Finally, bicultural identity indirectly affected psychological well‐being by mediating the effects of acculturative stress. These findings underscore the need to facilitate the adaptation of multicultural adolescents by reducing acculturative stress and promoting bicultural acceptance in educational institutions.  相似文献   
994.
995.
Non‐sagittal occlusal discrepancies such as posterior cross‐bite and anterior openbite are common types of malocclusion, but studies on masticatory function related to those malocclusions have been scarce. The aim of this study was to quantify the masticatory performance in patients with non‐sagittal discrepancies compared to those with normal occlusion, using both objective and subjective measures. Maximum bite force and contact area using Dental Prescale® system as a static objective assessment, Mixing Ability Index (MAI) as a dynamic objective evaluation and food intake ability (FIA) as a subjective assessment were analysed from 21 people in normal occlusion (Group N) and 64 patients with posterior cross‐bite (Group C), anterior openbite (Group O) or both (Group B). The differences of the maximum bite force, the contact area, the MAI and the FIA were compared, and their correlations were figured out. The non‐sagittal malocclusion groups showed lower values in the maximum bite force, the contact area, the MAI and the FIA compared to those in the normal group (< 0·0001). Compared to Group N, Groups C, O and B showed 61·5%, 42·1% and 40·1% of the maximum bite force, and 84%, 84% and 76% of hard food FIA, respectively. However, there were no significant differences among Groups C, O and B. The MAI showed higher correlation with the FIA (= 0·38, < 0·01), than with the maximum bite force and the contact area (both = 0·24, < 0·5). These results revealed that masticatory function in patients with non‐sagittal discrepancies is significantly reduced both objectively and subjectively.  相似文献   
996.
The striatum has a clear role in addictive disorders and is involved in drug-related craving. Recently, enhanced striatal volume was associated with greater lifetime nicotine exposure, suggesting a bridge between striatal function and structural phenotypes. To assess this link between striatal structure and function, we evaluated the relationship between striatal morphology and this brain region''s well-established role in craving. In tobacco smokers, we assessed striatal volume, surface area, and shape using a new segmentation methodology coupled with local shape indices. Striatal morphology was then related with two measures of craving: state-based craving, assessed by the brief questionnaire of smoking urges (QSU), and craving induced by smoking-related images. A positive association was found between left striatal volume and surface area with both measures of craving. A more specific relationship was found between both craving measures and the dorsal, but not in ventral striatum. Evaluating dorsal striatal subregions showed a single relationship between the caudate and QSU. Although cue-induced craving and the QSU were both associated with enlarged striatal volume and surface area, these measures were differentially associated with global or more local striatal volumes. We also report a connection between greater right striatal shape deformations and cue-induced craving. Shape deformations associated with cue-induced craving were specific to striatal subregions involved in habitual responding to rewarding stimuli, which is relevant given the habitual nature of cue-induced craving. The current findings confirm a relationship between striatal function and morphology and suggest that variation in striatal morphology may be a biomarker for craving severity.  相似文献   
997.
998.
999.
1000.
Many studies have reported that Aldehyde dehydrogenase 1 (ALDH1) and tumor-infiltrating lymphocytes (TIL) are related to breast cancer prognosis. However, the clinical significance of ALDH1 and tumor-infiltrating immune cells in breast cancer has not been fully investigated in patients who received neoadjuvant chemotherapy (NAC). We studied the significance of the expression of ALDH1 and the population of TIL for predicting the prognosis and chemotherapeutic response of patients with breast cancer who had received NAC. Forty patients who underwent NAC were enrolled in this study. ALDH1 and TIL (T cells and tumor associated macrophages) were evaluated before and after NAC. The influences of ALDH1 expression status and TIL populations on both prognosis and chemotherapeutic response were evaluated. ALDH1 positivity was related to estrogen receptor (p?=?0.026) and progesterone receptor negativity (p?=?0.025). Positive change of ALDH1 after NAC tended to be associated with a poor NAC response (p?=?0.078). Patients with more CD8+ T cells before NAC and fewer CD68 (+) macrophages after NAC tended to have better OS, respectively (p?=?0.086, p?=?0.096). The chemotherapeutic response and prognosis of patients with breast cancer who received NAC are thought to be determined by the tumor microenvironment. Further research with more patients and a longer study period is needed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号