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   2636篇
  免费   153篇
  国内免费   14篇
耳鼻咽喉   8篇
儿科学   58篇
妇产科学   67篇
基础医学   264篇
口腔科学   38篇
临床医学   190篇
内科学   645篇
皮肤病学   20篇
神经病学   235篇
特种医学   105篇
外科学   560篇
综合类   9篇
一般理论   1篇
预防医学   82篇
眼科学   18篇
药学   209篇
中国医学   2篇
肿瘤学   292篇
  2023年   17篇
  2022年   34篇
  2021年   42篇
  2020年   40篇
  2019年   52篇
  2018年   62篇
  2017年   50篇
  2016年   47篇
  2015年   50篇
  2014年   92篇
  2013年   118篇
  2012年   160篇
  2011年   120篇
  2010年   84篇
  2009年   69篇
  2008年   104篇
  2007年   106篇
  2006年   114篇
  2005年   116篇
  2004年   95篇
  2003年   98篇
  2002年   92篇
  2001年   83篇
  2000年   92篇
  1999年   72篇
  1998年   32篇
  1997年   32篇
  1996年   29篇
  1995年   26篇
  1994年   26篇
  1993年   15篇
  1992年   65篇
  1991年   56篇
  1990年   43篇
  1989年   52篇
  1988年   52篇
  1987年   45篇
  1986年   31篇
  1985年   36篇
  1984年   23篇
  1983年   14篇
  1982年   13篇
  1980年   13篇
  1978年   14篇
  1977年   14篇
  1974年   12篇
  1973年   14篇
  1972年   14篇
  1971年   23篇
  1967年   13篇
排序方式: 共有2803条查询结果,搜索用时 15 毫秒
71.
In 2019-2020, the SARS-CoV-2 pandemic has shocked the world and most health care systems, and a “second wave” of the viral spread is ongoing in Europe and in Italy too. While, at the initial outbreak, the treatment of patients had focused on the respiratory symptoms, many diverse clinical manifestations of the disease have to date been reported. However, the complete course of the disease has not yet been fully clarified. In particular, several reports from the real-world clinical practice have highlighted the noxious effects of SARS-CoV-2 on skeletal muscles. In this brief review, we summarized the main current findings about muscular and neuromuscular damages that may be triggered by the virus or by the drugs used to treat COVID-19. Moreover, we underlined the need of attentive care and vigilance for patients with neuro-muscular disorders, who may be particularly susceptible to infection and at increased risk for severe COVID-19.Key words: SARS-CoV-2, COVID-19, skeletal muscles  相似文献   
72.
73.
BACKGROUND: HIV infection is one of the leading causes of acquired heart disease. Because of its high diffusion, systematic echocardiographic monitoring has been proposed to exclude cardiovascular involvement in these patients. The aim of this study was to evaluate an alternative clinical approach by which echocardiographic screening is limited to patients with a clinical suspicion of heart disease. METHODS: We studied 2030 consecutive HIV-infected patients admitted to a tertiary referral hospital (group A). History, physical examination, ECG, and chest X-ray were used to screen HIV-infected patients for cardiovascular involvement. Selected patients were extensively studied, first of all by echocardiography. Cardiovascular and non-cardiovascular deaths were recorded: RESULTS: Cardiovascular involvement was clinically suspected in 201 patients (9.9%; group B). Among them a higher extracardiac mortality was found in presence of pericardial disease (odds ratio [OR] 4.27, 95% confidence interval [CI] 2.01-9.09), while a higher cardiovascular mortality was recorded for patients with cardiomyopathy or myocarditis (OR 2.72, 95% CI 1.09-6.81), and right ventricular dysfunction and/or pulmonary hypertension (OR 4.67, 95% CI 1.44-15.2). Compared with group A, patients in group B had a significantly increased cardiac death rate (0.114 vs 0.018, p < 0.001). A positive echocardiogram slightly increased this rate (from 0.114 to 0.164, p = NS), whereas a negative echocardiogram significantly decreased the cardiac death rate (0.015 vs 0.164, p = 0.004). CONCLUSIONS: Clinical selection of HIV-infected patients with suspected cardiovascular involvement may help identify patients with higher frequency of cardiovascular involvement. Among these patients, echocardiography may be a useful screening tool in those at high risk for cardiovascular death.  相似文献   
74.

Background

The second-generation cryoballoon (CB-A) (Arctic Front Advance, Cryocath, Medtronic, MN, USA) might significantly improve procedural outcome with respect to the first-generation balloon. These technological improvements might also question the current recommendation of the need a 4-min freeze to achieve durable pulmonary vein isolation (PVI).

Objective

The main aim of the study was to analyze the procedural efficacy of a 3-min freeze–thaw cycles with the CB-A balloon in the terms of rates of acute PVI and 6-month outcome.

Methods

Patients having undergone CB-A for PAF or early persistent AF, with 3-min freeze–thaw cycles were consecutively included in our analysis. Acute procedural success was measured in terms of the rate of PVI. Short-term follow-up was evaluated by the means of 24-h Holters and clinical examinations at regular intervals.

Results

Fifty-two consecutive patients (35 male (67 %); mean age, 59.8?±?10.5) were included. Mean procedure and fluoroscopy times were 96?±?15 and 13.2?±?8.3 min, respectively. Mean time from groin puncture to catheter extraction was 60.4?±?20 min. After a mean of 1.5 freeze cycles per vein of 3 min in duration, all 208 (100 %) PVs could be isolated with the CB-A. A total 192 (91 %) veins were isolated during the first freeze. At a mean of 5.7-month follow-up, 82 % of patients were free of AF.

Conclusion

CB-A is effective in producing PVI by using 3-min-duration freeze cycles. After a mean of 1.5 freeze per vein, freedom from AF was achieved in 82 % of patients at 6-month follow-up.  相似文献   
75.
Understanding the balance between fidelity and adaptation for evidence‐based interventions has the potential to improve their translation from research to practice. The Translation into Practice study explores variation in program implementation within organizations utilizing the RESPECT program, an HIV counseling and testing intervention. Counselors (N = 70) were interviewed using a semistructured interview guide to examine both the influential factors on, and the subsequent adaptations to, RESPECT. Almost all counselors reported making adaptations (N = 69). Adaptations were made both to key characteristics (mean [M] = 2.24, standard deviation [SD] = 1.3) and to core components (M = 0.5, SD = 0.8). Counselors identified the environmental context and factors within the counseling context as common influences leading to adaptation. These findings suggest adaptations were a routine part of program usage. To improve implementation of the RESPECT program, further research is needed to assess the degree to which adaptations can be made to better meet the needs of agencies and clients without compromising fidelity.  相似文献   
76.

Background/Aims

The prognosis of pancreatic adenocarcinoma (PAC) is poor. The serum carbohydrate antigen 19-9 (CA 19-9) level has been identified as a prognostic indicator of recurrence and reduced overall survival. The aim of this study was to identify preoperative prognostic factors and to create a prognostic model able to assess the early recurrence risk for patients with resectable PAC.

Methods

A series of 177 patients with PAC treated surgically at the St. Andrea Hospital of Rome between January 2003 and December 2011 were reviewed retrospectively. Univariate and multivariate analyses were utilized to identify preoperative prognostic indicators.

Results

A preoperative CA 19-9 level >228 U/mL, tumor size >3.1 cm, and the presence of pathological preoperative lymph nodes statistically correlated with early recurrence. Together, these three factors predicted the possibility of an early recurrence with 90.4% accuracy. The combination of these three preoperative conditions was identified as an independent parameter for early recurrence based on multivariate analysis (p=0.0314; hazard ratio, 3.9811; 95% confidence interval, 1.1745 to 15.3245).

Conclusions

PAC patient candidates for surgical resection should undergo an assessment of early recurrence risk to avoid unnecessary and ineffective resection and to identify patients for whom palliative or alternative treatment may be the treatment of choice.  相似文献   
77.
78.
79.
International guidelines recommend to reduce blood pressure (BP) levels below 130/80 mmHg in non-dialysis chronic kidney disease (CKD) patients. However, this BP target has not been validated by randomized controlled trials and is mainly driven by data obtained in observational and post-hoc analyses suggesting that it improves the renal and, to some extent, cardiovascular prognosis. The inconclusive results on the prognostic role of the BP target in patients with CKD might also relate to the limited ability of office BP readings to adequately stratify the global risk of this population. In fact, alterations of the pressure profile (such as white-coat hypertension) and nighttime hypertension are common in CKD patients. Recent studies have demonstrated that ambulatory blood pressure monitoring (ABPM) is superior to clinic BP measurements in predicting renal death and cardiovascular events. Therefore, while waiting for the results from the ongoing randomized Systolic Blood Pressure Intervention Trial (SPRINT) comparing the effect on cardiorenal prognosis of two BP target levels, the more widespread use of ABPM is desirable in CKD patients.  相似文献   
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