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   20459篇
  免费   2336篇
  国内免费   469篇
耳鼻咽喉   405篇
儿科学   661篇
妇产科学   132篇
基础医学   1885篇
口腔科学   123篇
临床医学   2944篇
内科学   2558篇
皮肤病学   33篇
神经病学   6714篇
特种医学   356篇
外国民族医学   1篇
外科学   855篇
综合类   2063篇
预防医学   1681篇
眼科学   520篇
药学   1309篇
  13篇
中国医学   612篇
肿瘤学   399篇
  2024年   135篇
  2023年   574篇
  2022年   844篇
  2021年   1268篇
  2020年   1212篇
  2019年   1243篇
  2018年   1151篇
  2017年   1199篇
  2016年   1090篇
  2015年   943篇
  2014年   1588篇
  2013年   2123篇
  2012年   1199篇
  2011年   1099篇
  2010年   869篇
  2009年   871篇
  2008年   809篇
  2007年   775篇
  2006年   698篇
  2005年   510篇
  2004年   431篇
  2003年   415篇
  2002年   328篇
  2001年   260篇
  2000年   209篇
  1999年   162篇
  1998年   134篇
  1997年   155篇
  1996年   127篇
  1995年   99篇
  1994年   88篇
  1993年   84篇
  1992年   74篇
  1991年   65篇
  1990年   51篇
  1989年   55篇
  1988年   44篇
  1987年   48篇
  1986年   42篇
  1985年   39篇
  1984年   33篇
  1983年   17篇
  1982年   23篇
  1981年   18篇
  1980年   13篇
  1979年   14篇
  1978年   10篇
  1976年   6篇
  1975年   6篇
  1974年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的通过观察清热化瘀Ⅱ号方对缺血性中风患者神经功能缺损评分、中医证候评分的影响,评价其对急性缺血性中风的中医证候疗效。方法选取急性缺血性中风患者72例,随机分为治疗组与对照组,每组36例。在常规治疗基础上,治疗组予清热化瘀Ⅱ号方治疗,对照组予天丹通络胶囊治疗,从K患者入院并筛选分组后开始给药,两组均治疗2周,观察并比较治疗前后两组患者神经功能缺损的评分、中医证候疗效及中医证候证候积分值。结果两组治疗前神经功能缺损评分差异无统计学意义(P〉0.05),治疗后治疗组与对照组比较差异有统计学意义(P〈0.05或P〈0.01)。中医证候疗效总有效率治疗组为91.18%,对照组为71.43%,治疗组优于对照组(P〈0.05),且治疗组中医证候积分减少明显优于对照组(P〈0.01)。结论清热化瘀Ⅱ号方可明显改善急性缺血性中风患者神经功能缺损评分及中医证候评分。  相似文献   
62.

Objective

To establish the local incidence of hearing loss in newborns with Hypoxic Ischaemic Encephalopathy (HIE) and to identify associated risk factors.

Study design

Retrospective Cohort Study. Neonatal Intensive Care Unit (NICU) dual stage hearing screening protocol, including automated otoacoustic emissions (AOAE) and automated auditory brainstem response (AABR) testing.

Results

57 newborns received therapeutic hypothermia for HIE. Twelve babies (21%) died. Audiology data was incomplete in 3 babies. Complete data was available for 42 babies (male n = 24), 4 (9.5%) of whom had hearing impairment. The development of hearing loss was associated with abnormal blood glucose levels (p = 0.006), low Apgar score at 1 min (p = 0.0219) and evidence of multi organ dysfunction [high creatinine (p = 0.0172 and 0.0198) and raised liver transaminases (aspartate aminotransferase (AST) p = 0.0012, alanine aminotransferase (ALT) p = 0.0037)]. An association with gentamicin was not found.

Conclusion

This study confirms that hearing impairment is common in term infants who have undergone therapeutic hypothermia for moderate/severe HIE. Blood glucose should be monitored carefully in these infants and developmental surveillance should include formal audiology. Further larger studies are needed to clarify the role, if any, of hypothermia per se in causation of hearing loss and to fully identify risk factors for hearing impairment in this population.

What is new

The current study confirms that hearing impairment is common in term infants who have undergone therapeutic hypothermia for moderate/severe HIE.No association between gentamicin use and the development of hearing impairment was found however initial blood glucose outside the normal range was of significance.Other factors associated with hearing impairment were low Apgar scores, greater need for resuscitation and evidence of multi organ dysfunction (renal and liver failure).  相似文献   
63.
64.

Objective

To determine the effects of ethinyl estradiol (EE)/drospirenone in a 24/4 regimen (24 days of active and 4 days of inactive pills) on functional impairment (affecting work, partnership, and social activities) in women with premenstrual dysphoric disorder (PMDD).

Methods

The present study was a secondary analysis of a double-blind, randomized, parallel-design multicenter trial. Women received EE 20 μg/drospirenone 3 mg (n = 232) or placebo (n = 218) and completed the Daily Record of Severity of Problems (DRSP) scale daily.

Results

The decrease in mean scores for all 3 DRSP functional impairment items (work, partnership, and social activities) from baseline to cycle 3 mirrored changes in the total DRSP symptom score; the greatest decreases were observed in cycle 1 with further small reductions through to cycle 3. The proportional mean decreases from baseline to cycle 1 for the 3 functional items ranged from 47% to 48%. For all 3 functional items, the mean reductions from baseline to cycle 1 (but not from cycle 1 to cycles 2 and 3) were significantly greater with EE/drospirenone than with placebo (P < 0.05).

Conclusion

Ethinyl estradiol 20 μg/drospirenone 3 mg in a 24/4 regimen significantly improved functional impairment in women with PMDD. Symptoms improved in parallel.  相似文献   
65.
中国是卒中和痴呆的大国,卒中后认知障碍是卒中常见的并发症,不仅严重影响患者生活质量,而且显著降低卒中患者的生存时间,给家庭及社会带来了沉重的负担。卒中后早期干预可以减少血管性痴呆的发生,血管性因素的可控性为痴呆的治疗提供了新的思路。《中国卒中后认知障碍管理专家共识》将切实指导临床,使得卒中患者的生活质量得以提高。  相似文献   
66.
Objective:To examine the effects of modified Shenmai Yin on invigorating vital energy, promoting blood flow, and protection against neural impairment in an endotoxin-induced shock rat model. Methods: Ninety-six SD rats were randomly divided into four groups: sham operation (saline 20 ml/kg), shock model (lipopolysaccharide, LPS, 8 mg/kg), Reformed Shengmai Yin (加味生脉饮 Pulse-activating Decoction) (LPS 8 mg/kg + reformed Shengmai Yin Injection 10 ml/kg), and dexamethasone (LPS 8 mg/kg + dexamethasone 5 mg/kg) groups. Each group was subdivided into 1 h, 2 h, 3 h, and 6 h time points for observation. The carotid artery was separated and connected with a biological functional system to monitor mean arterial pressure (MAP). Brain water levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity were also determined. Results: In the shock model group, MAP was progressively decreased after injection of LPS, brain water and MDA contents were increased, brain SOD activity was decreased, and capillary vessel edema in brain tissue was also observed. All these parameters were improved significantly in both treatment groups, although the effects were more marked with Shengmai Yin than with dexamethasone. Conclusion: Modified Shengmai Yin exhibits strong anti-shock and neuroprotective effects against Endotoxininduced shock.  相似文献   
67.
Chemotherapy-induced cognitive impairment (CICI) has emerged as a significant medical problem without therapeutic options. Using the platinum-based chemotherapy cisplatin to model CICI, we revealed robust elevations in the adenosine A2A receptor (A2AR) and its downstream effectors, cAMP and CREB, by cisplatin in the adult mouse hippocampus, a critical brain structure for learning and memory. Notably, A2AR inhibition by the Food and Drug Administration–approved A2AR antagonist KW-6002 prevented cisplatin-induced impairments in neural progenitor proliferation and dendrite morphogenesis of adult-born neurons, while improving memory and anxiety-like behavior, without affecting tumor growth or cisplatin’s antitumor activity. Collectively, our study identifies A2AR signaling as a key pathway that can be therapeutically targeted to prevent cisplatin-induced cognitive impairments.  相似文献   
68.
High-fat diets are associated with neuronal and memory dysfunction. Berries may be useful in improving age-related memory deficits in humans, as well as in mice receiving high-fat diets. Emerging research has also demonstrated that brain health and cognitive function may be related to the dynamic changes in the gut microbiota. In this study, the impact of Nordic berries on the brain and the gut microbiota was investigated in middle-aged C57BL/6J mice. The mice were fed high-fat diets (60%E fat) supplemented with freeze-dried powder (6% dwb) of bilberry, lingonberry, cloudberry, blueberry, blackcurrant, and sea buckthorn for 4 months. The results suggest that supplementation with bilberry, blackcurrant, blueberry, lingonberry, and (to some extent) cloudberry has beneficial effects on spatial cognition, as seen by the enhanced performance following the T-maze alternation test, as well as a greater proportion of DCX-expressing cells with prolongation in hippocampus. Furthermore, the proportion of the mucosa-associated symbiotic bacteria Akkermansia muciniphila increased by 4–14 times in the cecal microbiota of mice fed diets supplemented with lingonberry, bilberry, sea buckthorn, and blueberry. These findings demonstrate the potential of Nordic berries to preserve memory and cognitive function, and to induce alterations of the gut microbiota composition.  相似文献   
69.
IntroductionThe detection in mild cognitive impairment (MCI) of metabolic alterations suggestive of depression and/or of evolution to dementia.MethodsSixty-nine MCI patients underwent clinical and imaging evaluation including position emission tomography/computed tomography with fluorodeoxy-glucose (FDG-PET/CT).ResultsThe metabolism mean values in parietal, temporal and pre-cuneus areas were lower in subjects who evolved to dementia, and in frontal and in anterior cingulate areas in depressed subjects. Abnormal metabolism values were higher in the frontal and parietal lobes, and in the precuneus in subjects who evolved to dementia independently from depression.ConclusionsIn MCI FDG-PET/CT abnormality patterns suggest the presence of depression or the evolution to dementia.  相似文献   
70.
Study ObjectivesSleep abnormalities emerge early in dementia and may accelerate cognitive decline. Their accurate characterization may facilitate earlier clinical identification of dementia and allow for assessment of sleep intervention efficacy. This scoping review determines how sleep is currently measured and reported in Mild Cognitive Impairment (MCI) and early dementia, as a basis for future core outcome alignment.MethodsThis review follows the PRISMA Guidelines for Scoping Reviews. CINAHL, Embase, Medline, Psychinfo, and British Nursing Index databases were searched from inception—March 12, 2021. Included studies had participants diagnosed with MCI and early dementia and reported on sleep as a key objective/ outcome measure.ResultsNineteen thousand five hundred and ninety-six titles were returned following duplicate removal with 188 studies [N] included in final analysis. Sleep data was reported on 17 139 unique, diagnostically diverse participants (n). “Unspecified MCI” was the most common diagnosis amongst patients with MCI (n = 5003, 60.6%). Despite technological advances, sleep was measured most commonly by validated questionnaires (n = 12 586, N = 131). Fewer participants underwent polysomnography (PSG) (n = 3492, N = 88) and actigraphy (n = 3359, N = 38) with little adoption of non-PSG electroencephalograms (EEG) (n = 74, N = 3). Sleep outcome parameters were reported heterogeneously. 62/165 (37.6%) were described only once in the literature (33/60 (60%) in interventional studies). There was underrepresentation of circadian (n = 725, N = 25) and micro-architectural (n = 360, N = 12) sleep parameters.ConclusionsAlongside under-researched areas, there is a need for more detailed diagnostic characterization. Due to outcome heterogeneity, we advocate for international consensus on core sleep outcome parameters to support causal inference and comparison of therapeutic sleep interventions.  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