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   3091篇
  免费   190篇
  国内免费   38篇
耳鼻咽喉   18篇
儿科学   90篇
妇产科学   73篇
基础医学   465篇
口腔科学   69篇
临床医学   230篇
内科学   683篇
皮肤病学   76篇
神经病学   218篇
特种医学   179篇
外科学   387篇
综合类   187篇
一般理论   1篇
预防医学   164篇
眼科学   62篇
药学   204篇
中国医学   14篇
肿瘤学   199篇
  2023年   16篇
  2022年   11篇
  2021年   58篇
  2020年   35篇
  2019年   67篇
  2018年   59篇
  2017年   47篇
  2016年   83篇
  2015年   106篇
  2014年   177篇
  2013年   206篇
  2012年   195篇
  2011年   230篇
  2010年   161篇
  2009年   135篇
  2008年   142篇
  2007年   167篇
  2006年   145篇
  2005年   104篇
  2004年   101篇
  2003年   103篇
  2002年   74篇
  2001年   62篇
  2000年   45篇
  1999年   51篇
  1998年   68篇
  1997年   58篇
  1996年   51篇
  1995年   37篇
  1994年   42篇
  1993年   38篇
  1992年   24篇
  1991年   26篇
  1990年   24篇
  1989年   48篇
  1988年   33篇
  1987年   33篇
  1986年   23篇
  1985年   18篇
  1984年   19篇
  1983年   10篇
  1982年   14篇
  1981年   14篇
  1980年   13篇
  1976年   7篇
  1975年   8篇
  1966年   7篇
  1965年   6篇
  1963年   6篇
  1941年   11篇
排序方式: 共有3319条查询结果,搜索用时 15 毫秒
1.
2.
Rapid nonclassical effects of 17β‐oestradiol (E2) on intracellular signalling have been identified in the basal forebrain, although the extent to which these actions may be different in males and females is unknown. Previous work has shown that E2 rapidly phosphorylates cAMP responsive element binding protein (CREB) via ΕRα in female cholinergic neurones. Using this indicator, the present study examined whether nonclassical actions of E2 occur in a sexually dimorphic manner within basal forebrain cholinergic neurones in mice. In addition, we investigated the expression and intracellular distribution of oestrogen receptor (ΕR)α in cholinergic neurones in female and male mice. Animals were gonadectomised and treated 2 weeks later with E2. The number of CREB‐expressing cholinergic neurones was not altered in any of the brain regions after E2 treatment in both males and females. However, E2 treatment rapidly (< 15 minutes) increased (P < 0.05) the number of cholinergic neurones expressing phosphorylated CREB (pCREB) in the substantia innominata and medial septum but not in the striatum in female mice. By contrast, E2 did not change pCREB expression in cholinergic neurones in male mice at any time point (15 minutes, 1 hour, 4 hours), irrespective of the neuroanatomical location. We also observed that, in females, more cholinergic neurones expressed nuclear ΕRα in all regions, whereas males showed more cholinergic neurones with cytoplasmic or both nuclear and cytoplasmic expression of ΕRα. Taken together, these results demonstrate a marked sex difference in the E2‐induced nonclassical effect and intracellular distribution of ΕRα in basal forebrain cholinergic neurones in vivo.  相似文献   
3.
Oncogenic Ras stimulates macropinocytosis, a clathrin-independent endocytosis that increases the uptake of extracellular fluid. However, the functional significance of and regulatory mechanisms driving macropinocytosis in cancer cells remain largely unknown. Here, we show that extracellular macromolecules, such as albumin, internalized by Ras-expressing cells can support growth and survival under the nutrient-deprived conditions like those found in tumors. Moreover, we demonstrate that autophagy, a lysosome-mediated catabolic pathway, is required for the uptake and degradation of macropinocytic vesicles. Intracellular metabolites derived from macropinocytosis and autophagy directly influence the activity and localization of mTOR, which is ultimately responsible for the restoration of cell growth. Surprisingly, suppression of mTORC1, which typically triggers anabolic processes, facilitates macropinocytosis and thus supports cell growth and survival under the nutrient-deprived conditions. In a mouse xenograft model of pancreatic ductal adenocarcinoma, concomitant inhibition of macropinocytosis/autophagy and mTOR activity resulted in antitumor effects. These data suggest that novel anti-cancer strategies interrupting these metabolic processes and related signaling molecules may represent promising therapeutic avenues.  相似文献   
4.
5.
Journal of Clinical Immunology - Unconditioned hematopoietic stem cell transplantation (HSCT) is the recommended treatment for patients with adenosine deaminase (ADA)-deficient severe combined...  相似文献   
6.

Background

Lifestyle, in particular obesity and smoking has significant impacts on fertility and an important focus for the treatment of reproductive failures is the optimisation of periconceptional lifestyle behaviours. The preimplantation intrauterine environment within the uterus is also key for embryo development and early programming. Although the benefits a healthy periconceptional lifestyle are well described, there remains a paucity of data demonstrating the efficacy of interventions designed to optimise preconceptional lifestyle behaviours and choices.

Methods

This study is a prospective randomised controlled trial which aims to address the question of whether an online personalised lifestyle coaching application is an effective means of delivering periconceptional advice in women suffering from reproductive failures. Women suffering from subfertility or recurrent miscarriages attending the outpatient clinic will be randomised into either the intervention arm (personalised online lifestyle coaching application) or the control arm (standard periconceptional advice including information from NHS websites). Both groups will be asked to complete a validated lifestyle questionnaire at baseline, and 6, 12, 18 and 24?weeks after randomisation. The primary outcome is the composite dietary and lifestyle risk score at 12?weeks. The secondary outcomes will include compliance with the program, proportion achieving spontaneous conception during the study period and the dietary and lifestyle risk score at 24?weeks.

Discussion

With this study, we aim to clarify whether a personalised online based lifestyle coaching application is more effective at improving behaviours than standard advice offered by National Health Service (NHS) resources. A personalised lifestyle coaching application may represent an empowering and cost effective means of delivering periconceptional advice in women with subfertility or recurrent miscarriages.

Trial registration

The iPLAN trial was retrospectively registered (ISRCTN 89523555).
  相似文献   
7.
Head and neck cancer is becoming a more recognizable pathology to the general population and dentists. The modes of treatment include surgery and/or radiation therapy. Where possible, pretreatment dental assessment shall be provided for these patients before they undergo radiation therapy. There are occasions, however, whereby head and neck cancer patients are not prepared optimally for radiation therapy. Because of this, they succumb to complicated oral complications after radiation therapy. The management of xerostomia has been reviewed in Part I of this series. In this article, the management of dental caries, a sequalae of xerostomia following radiation therapy is reviewed.  相似文献   
8.
Head and neck cancer is becoming a more recognizable pathology to the general population and dentists. The modes of treatment include surgery and/or radiation therapy. Where possible, pretreatment dental assessment shall be provided for these patients before they undergo radiation therapy. There are occasions, however, whereby head and neck cancer patients are not prepared optimally for radiation therapy. Because of this, they succumb to complicated oral adverse effects after radiation therapy. The second last part of this series reviews and discusses the management of complication that commonly occur to the oral mucosa, i.e. mucositis.  相似文献   
9.
Unintended intravascular injection from inferior alveolar nerve blocks can result in frustrating distant complications affecting such structures as the middle ear and eyes. Possible complications affecting the eyes include blurring of vision, diplopia, mydriasis, palpebral ptosis and amaurosis (temporary or permanent). In this article, we present a complication that has been reported only rarely. Two patients developed transient loss of power of accommodation of the eye resulting in blurred vision after routine inferior alveolar nerve blocks on the ipsilateral side. Clear vision returned within 10-15 minutes after completion of the blocks. The possible explanation for this phenomenon is accidental injection into the neurovascular bundle of local anesthetic agents, which were carried via the blood to the orbital region. This resulted in paralysis of a branch of cranial nerve III, the short ciliary nerves that innervate the ciliary muscle, which controls accommodation.  相似文献   
10.
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