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   83962篇
  免费   7794篇
  国内免费   2213篇
耳鼻咽喉   242篇
儿科学   1180篇
妇产科学   1253篇
基础医学   10439篇
口腔科学   2057篇
临床医学   8898篇
内科学   12248篇
皮肤病学   527篇
神经病学   8948篇
特种医学   2351篇
外国民族医学   2篇
外科学   7649篇
综合类   8537篇
现状与发展   6篇
一般理论   2篇
预防医学   11431篇
眼科学   882篇
药学   10293篇
  58篇
中国医学   4105篇
肿瘤学   2861篇
  2024年   104篇
  2023年   1426篇
  2022年   1940篇
  2021年   3606篇
  2020年   4015篇
  2019年   3155篇
  2018年   3036篇
  2017年   3363篇
  2016年   3471篇
  2015年   3410篇
  2014年   6109篇
  2013年   7238篇
  2012年   5150篇
  2011年   5759篇
  2010年   4482篇
  2009年   4522篇
  2008年   4517篇
  2007年   3977篇
  2006年   3619篇
  2005年   2842篇
  2004年   2527篇
  2003年   2266篇
  2002年   1804篇
  2001年   1513篇
  2000年   1191篇
  1999年   950篇
  1998年   788篇
  1997年   717篇
  1996年   619篇
  1995年   589篇
  1994年   507篇
  1993年   455篇
  1992年   445篇
  1991年   384篇
  1990年   406篇
  1989年   357篇
  1988年   331篇
  1987年   274篇
  1986年   270篇
  1985年   345篇
  1984年   286篇
  1983年   187篇
  1982年   204篇
  1981年   175篇
  1980年   158篇
  1979年   114篇
  1978年   93篇
  1977年   61篇
  1976年   79篇
  1975年   33篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
We make the case for why continuous pharmaceutical manufacturing is essential, what the barriers are, and how to overcome them. To overcome them, government action is needed in terms of tax incentives or regulatory incentives that affect time.  相似文献   
93.
《Vaccine》2019,37(25):3343-3351
The intracellular nature of Brucella leads to rise in oxidative stress due to bacterial invasion, particularly at the site of predilection spleen and lymph nodes. The present study aimed to evaluate the erythrocytic and tissue specific oxidative stress responses induced during oil adjuvant killed Brucella melitensis vaccination. The results of the study clearly implicated a significant increase in level of catalase, and superoxide dismutase (SOD) activity and lipid peroxidation (LPO), and total protein content in erythrocytes after vaccination. The activity of glutathione-S-transferase (GST) was unaltered during the period of experiment. The catalase activity and GSH content was significantly increased in lung and spleen tissues. The tissues GST levels increased significantly in all tissues, while tissue SOD level increased significantly only in lung tissues. Thus, it can be inferred that oil adjuvant based Brucella vaccine induces negligible signs of inflammatory pathophysiology and supports the development of significant level of protection against virulent Brucella challenge.  相似文献   
94.
The impact of stress on health can depend on factors such as frequency, heightening of stress during a given period or the presence of one or a few repeated hassles of psychological importance. The aim of this study was to gain a deeper understanding of how adult women experience and cope with daily hassles after sexual abuse. Ten interviews were analysed using the grounded theory method. The theoretical model of ‘protecting armor in daily life’ emerged. The aftermath of sexual abuse related coping with daily stress can be understood as a three‐phase process: (1) avoiding and escaping—coping after experiencing sexual abuse; (2) accepting and disclosing—starting a process of recovery; and (3) reconciling and repossessing—living with the experience in the present. The model contributes to a deeper understanding of the everyday life of women who have experienced sexual abuse. Increased knowledge of coping behaviours that can be used to deal with daily hassles may also serve as a tool for health professionals, other helpers and family to help these women rebuild a good life.  相似文献   
95.
DNA mixture interpretation can produce opposing conclusions by qualified forensic analysts, even within the same laboratory. The long-delayed publication of the National Institutes of Standards and Technology (NIST) study of 109 North American crime laboratories in this journal demonstrates this most clearly. This latest study supports earlier work that shows common methods such as the Combined Probability of Inclusion (CPI) have wrongly included innocent people as contributors to DNA mixtures. The 2016 President's Council of Advisors on Science and Technology report concluded, “In summary, the interpretation of complex DNA mixtures with the CPI statistic has been an inadequately specified—and thus inappropriately subjective—method. As such, the method is clearly not foundationally valid” [7]. The adoption of probabilistic genotyping by many laboratories will certainly prevent some of these errors from occurring in the future, but the same laboratories that produced past errors can also now review old cases with their new software—without additional bench work. It is critical that laboratories adopt procedures and policies to do this.  相似文献   
96.
Although patients with rosacea often consult dermatologists for dietary factors that might be related to their skin disorders, few studies have been conducted to research the relationship between rosacea and dietary factors. The purpose of this study was to evaluate the potential relationship between rosacea and diet among the large Chinese population with rosacea, which would provide dietary guidelines for patients with rosacea. A multicenter case–control study was conducted. The feeding frequency 2 years before the occurrence of rosacea was collected by standardized questionnaires. Multiple logistic regression analysis was used to calculate risks related to the diet. One thousand three hundred and forty‐seven patients with rosacea and 1290 controls were enrolled in our study. We found that high‐frequency intake of fatty food and tea presented a positive correlation with rosacea, while high‐frequency dairy product intake showed significant negative correlation with rosacea. Sweet food, coffee and spicy food appeared to be independent of any subset of rosacea in our study. However, high‐frequency dairy product intake showed a borderline beneficial effect on rosacea severity. We further analyzed the correlation between diet and the subtype of rosacea. We found that high‐frequency fatty intake was associated with erythematotelangiectatic rosacea (ETR) and phymatous rosacea, while high‐frequency tea intake was only associated with ETR. In addition, high‐frequency dairy product intake showed negative correlations with ETR and papulopustular rosacea. Rosacea is associated with some dietary factors, and our study is valuable in establishing dietary guidelines to prevent and improve rosacea.  相似文献   
97.
Objective. Skeletal muscle perfusion during walking relies on complex interactions between cardiac activity and vascular control mechanisms, why cardiac dysfunction may contribute to intermittent claudication (IC) symptoms. The study aims were to describe cardiac function at rest and during stress in consecutive IC patients, to explore the relations between cardiac function parameters and treadmill performance, and to test the hypothesis that clinically silent myocardial ischemia during stress may contribute to IC limb symptomatology. Design. Patients with mild to severe IC (n?=?111, mean age 67 y, 52% females, mean treadmill distance 195 m) underwent standard echocardiography, dobutamine stress echocardiography (SE) and treadmill testing. The patient cohort was separated in two groups based on treadmill performance (HIGH and LOW performance). Results. Ten patients (9%) had regional wall motion abnormalities of which three had left ventricular ejection fraction <50% at standard echocardiography. A majority had lower than expected systolic- and diastolic ventricular volumes. LOW performers had smaller diastolic left ventricular volumes and lower global peak systolic velocity during dobutamine stress. No patient demonstrated significant cardiac dysfunction during dobutamine provocation that was not also evident at standard echocardiography. Conclusions. Most IC patients were without signs of ischemic heart disease or cardiac failure. The majority had small left ventricular volumes. The hypothesis that clinically silent myocardial ischemia impairing left ventricular function during stress may contribute to IC limb symptomatology was not supported.

Trial registration: ClinicalTrials.gov identifier: NCT01219842.  相似文献   
98.

Aims

Delaying progression, ameliorating symptoms and maintaining quality of life (QoL) are primary aims of treatment for metastatic castrate-resistant prostate cancer (mCRPC). Real-world rather than clinical trial data about symptoms and side-effects are sparse. In EXTREQOL, patients' QoL, pain and information needs were recorded during treatment.

Material and methods

Men with mCRPC from 20 UK cancer centres starting various systemic mCRPC treatments completed QoL, pain and information needs questionnaires at baseline, 3 and 6 months.

Results

In total, 132 patients were recruited. Overall QoL declined significantly by 6 months (Functional Assessment of Cancer Therapy-Prostate [FACT-P] mean = –3.89, 95% confidence interval –6.7 to –1.05, P = 0.007; Trial Outcome Index [TOI] analysis mean = –3.10, 95% confidence interval –5.34 to –0.83, P = 0.007). Those who came off novel therapy and remained on luteinising hormone-releasing hormone agonist therapy alone had worse scores than patients receiving concomitant chemotherapy (Prostate Concerns Subscale mean difference = –4.45, 95% confidence interval –7.06 to –1.83, P = 0.001; TOI mean difference = –5.62, 95% confidence interval –10.97 to –0.26, P = 0.040). At 3 and 6 months, men who reported pain at baseline improved (43%, 40%), but for others pain levels remained the same (45%, 42%) or worsened (13%, 18%). Information regarding supportive care was lacking throughout the period of time on the study.

Conclusion

Most mCRPC treated patients experience reduced QoL and inadequate pain control. More help with pain management and better information provision regarding supportive care is warranted.  相似文献   
99.

Background

The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.

Objectives

The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.

Methods

PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.

Results

Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).

Conclusions

In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550)  相似文献   
100.
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