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   1693308篇
  免费   123787篇
  国内免费   2486篇
耳鼻咽喉   24284篇
儿科学   57954篇
妇产科学   46112篇
基础医学   250028篇
口腔科学   46123篇
临床医学   147460篇
内科学   331257篇
皮肤病学   37879篇
神经病学   129584篇
特种医学   65879篇
外国民族医学   714篇
外科学   258210篇
综合类   34220篇
现状与发展   1篇
一般理论   481篇
预防医学   128005篇
眼科学   38329篇
药学   127534篇
  2篇
中国医学   3239篇
肿瘤学   92286篇
  2018年   16895篇
  2016年   14056篇
  2015年   15859篇
  2014年   21997篇
  2013年   33801篇
  2012年   46150篇
  2011年   49340篇
  2010年   29349篇
  2009年   27916篇
  2008年   47408篇
  2007年   50767篇
  2006年   51323篇
  2005年   49841篇
  2004年   48759篇
  2003年   46948篇
  2002年   46304篇
  2001年   82228篇
  2000年   85510篇
  1999年   72078篇
  1998年   19404篇
  1997年   17419篇
  1996年   18104篇
  1995年   17001篇
  1994年   16098篇
  1993年   14985篇
  1992年   56742篇
  1991年   56201篇
  1990年   55092篇
  1989年   52759篇
  1988年   48651篇
  1987年   47941篇
  1986年   44733篇
  1985年   42894篇
  1984年   31969篇
  1983年   26959篇
  1982年   15432篇
  1981年   14132篇
  1980年   12801篇
  1979年   29186篇
  1978年   20527篇
  1977年   17355篇
  1976年   16372篇
  1975年   18008篇
  1974年   21204篇
  1973年   20242篇
  1972年   18928篇
  1971年   17543篇
  1970年   16448篇
  1969年   15220篇
  1968年   14030篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.

Objective

The teaching hospital of Nancy, France, implemented a specific multidisciplinary care pathway (French acronym AMDPL) to improve the management of patients presenting with Lyme borreliosis (LB) suspicion. We aimed to assess the first year of activity of this care pathway.

Patients and methods

We included all patients managed in the AMDPL pathway from November 1, 2016 to October 31, 2017. The first step was a dedicated Lyme disease consultation with an infectious disease specialist. Following this consultation, the LB diagnosis was either confirmed and adequate treatment was prescribed, or a differential diagnosis was established and patients received adequate management, or further investigations were required and patients were offered multidisciplinary management as part of a day hospitalization.

Results

A total of 468 patients were included. LB diagnosis was confirmed in 15% of patients (69/468), 49% of patients received a differential diagnosis, and 26% (122/468) of patients had the LB diagnosis ruled out without receiving any other diagnosis.

Conclusions

This is to our knowledge the first multidisciplinary center implemented in France for the management of patients presenting with LB suspicion related to polymorphous signs and symptoms. Several diagnoses could be confirmed or corrected, although some symptoms and complaints could not be explained. This cohort could improve our knowledge of LB and its differential diagnoses.  相似文献   
73.
74.
75.

Aim

The purpose of this study is to find out whether telephone referral from Primary Health Care to Internal Medicine Consult manages to reduce waiting days as compared to traditional referral. This study also aims to know how acceptable is the telephone referral to general practitioners and their patients.

Design

No blind randomized controlled clinical trial.

Setting

Northern Huelva Health District.

Participants

154 patients.

Interventions

Patients referrals from intervention clinicians were sent via telephone consultation, whereas patients referrals from control clinicians were sent by traditional via.

Measurements

Number of days from referral request to Internal Medicine Consult. Number of telephone and traditional referrals. Number of doctors and patients denied. Denial reasons.

Results

A statistically significant difference was found between groups, with an average of 27 (21-34) days. Among General Practitioners, 8 of the first 58 total doctors after randomization and, subsequently, 6 of the 20 doctors of the test group refused to engage in the trial because they considered “excessive time and effort consuming”. 50% of patients referred by the 14 General Practitioners finally randomized to the intervention group were denied referral by telephone due to patient's complexity.

Conclusions

Telephone referral significantly reduces waiting days for Internal Medicine consult. This type of referral did not mean an “excessive time and effort consuming” to General Practitioners and was not all that beneficial to complex patients  相似文献   
76.
Abstract

This study was undertaken to compare the concentrations of pro- and anti-angiogenic growth factors, nitric oxide (NO) stable metabolites in maternal serum and embryonic left ventricular (LV) isovolumic relaxation time (IRT, ms) during the first trimester in two groups of women: with pregnancy conceived by assisted reproductive technologies (ART, n?=?39) and normally conceived (control group, n?=?68) pregnancy. The concentration of vasoconstrictor endothelin 1 was 45.5 times more in ART than in control group. On the contrary, the concentrations of NO stable metabolites in ART were 1.9 times less than in control women. The assessment of angiogenic suppressors in ART women demonstrates the decrease in s-endoglin concentration was 1.6 times and in soluble receptor to vascular endothelial growth factor concentration was 2.0 times in comparison with control group. There was a significant increase in LV IRT in ART embryos in comparison to control ones. These data suggest significant changes in pro- anti-angiogenic factors balance and increase in vascular impedance in ART-conceived embryos.  相似文献   
77.
78.
BACKGROUND AND PURPOSE:Cognitive challenges are prevalent in survivors of glioma, but their neurobiology is incompletely understood. The purpose of this study was to investigate the effect of glioma presence and tumor characteristics on resting-state functional connectivity and amplitude of low-frequency fluctuations of the salience network, a key neural network associated with cognition.MATERIALS AND METHODS:Sixty-nine patients with glioma (mean age, 48.74 [SD, 14.32] years) who underwent resting-state fMRI were compared with 31 healthy controls (mean age, 49.68 [SD, 15.54] years). We identified 4 salience network ROIs: left/right dorsal anterior cingulate cortex and left/right anterior insula. Average salience network resting-state functional connectivity and amplitude of low-frequency fluctuations within the 4 salience network ROIs were computed.RESULTS:Patients with gliomas showed decreased overall salience network resting-state functional connectivity (P = .001) and increased amplitude of low-frequency fluctuations in all salience network ROIs (P < .01) except in the left dorsal anterior cingulate cortex. Compared with controls, patients with left-sided gliomas showed increased amplitude of low-frequency fluctuations in the right dorsal anterior cingulate cortex (P = .002) and right anterior insula (P < .001), and patients with right-sided gliomas showed increased amplitude of low-frequency fluctuations in the left anterior insula (P = .002). Anterior tumors were associated with decreased salience network resting-state functional connectivity (P < .001) and increased amplitude of low-frequency fluctuations in the right anterior insula, left anterior insula, and right dorsal anterior cingulate cortex. Patients with high-grade gliomas had decreased salience network resting-state functional connectivity compared with healthy controls (P < .05). The right anterior insula showed increased amplitude of low-frequency fluctuations in patients with grade II and IV gliomas compared with controls (P < .01).CONCLUSIONS:By demonstrating decreased resting-state functional connectivity and an increased amplitude of low-frequency fluctuations related to the salience network in patients with glioma, this study adds to our understanding of the neurobiology underpinning observable cognitive deficits in these patients. In addition to more conventional functional connectivity, amplitude of low-frequency fluctuations is a promising functional-imaging biomarker of tumor-induced vascular and neural pathology.

Detrimental effects of cancer on cognitive function and, consequently, on the quality of life are emerging as a key focus of cancer survivorship both in research and clinical practice.1,2 Brain tumors have been shown to affect memory, processing, and attention in patients; however, their underlying neurobiology is incompletely understood.3 Using resting-state functional MR imaging (rsfMRI) to evaluate changes in cognitive resting-state networks may provide a better understanding of the pathology underlying the observable cognitive disruptions in gliomas, the most common primary brain tumor in adults.A “triple network model” of neurocognitive pathology has been proposed, which encompasses the default mode network, involved in mind wandering; the central executive network, involved in decision-making; and the salience network (SN), implicated in modulating activation of the default mode network and central executive network by detecting the presence of salient stimuli.4-8 While previous rsfMRI research has largely focused on tumor-induced changes in the default mode network,9,10 our study examined the less-studied SN, a network rooted in the anterior insula and the dorsal anterior cingulate cortex.6Prior studies evaluating gliomas and SN resting-state functional connectivity (RSFC) provided conflicting results in small patient samples: Maesawa et al10 found no significant differences in the SN in 12 patients, while Liu et al11 more recently found decreased SN connectivity in 13 patients. Gliomas impact the integrity of the neurovascular unit to varying degrees, resulting in neurovascular uncoupling that has been reported to confound fMRI interpretations in patients with brain tumors.12-14 Additionally, research has reported neuronal plasticity manifested by structural reorganization and functional remodeling of neural networks in patients with gliomas with possible alterations in clinically observable cognitive manifestations.15-17 An rsfMRI metric, the amplitude of low-frequency fluctuations (ALFF), has recently shown promise as a biomarker for brain plasticity and hemodynamic characterization, including neurovascular uncoupling in patients with gliomas.15-19The purpose of this study was to investigate the effect of glioma presence and tumor characteristics on overall RSFC and regional normalized ALFF within the SN in a large patient population. We hypothesized that there would be decreased average SN RSFC and altered ALFF in patients with gliomas compared with healthy controls. Recent studies have acknowledged that gliomas have variable effects on network integrity based on lesion location and proximity to network ROIs,20-22 and unilateral gliomas can be associated with plasticity in both the ipsilateral and contralateral hemispheres.11,17 Research also supports differences in resting-state network reorganization in aggressive high-grade gliomas compared with slower-growing low-grade gliomas.20,23 Therefore, we also hypothesized that there would be differences in average SN RSFC and regional ALFF in patients based on the anterior-versus-posterior location, hemispheric side, and grade of glioma.  相似文献   
79.
80.
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