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   3309篇
  免费   190篇
  国内免费   25篇
耳鼻咽喉   71篇
儿科学   235篇
妇产科学   156篇
基础医学   324篇
口腔科学   105篇
临床医学   338篇
内科学   667篇
皮肤病学   128篇
神经病学   171篇
特种医学   142篇
外科学   371篇
综合类   77篇
预防医学   243篇
眼科学   72篇
药学   257篇
中国医学   19篇
肿瘤学   148篇
  2023年   50篇
  2022年   78篇
  2021年   145篇
  2020年   95篇
  2019年   148篇
  2018年   138篇
  2017年   105篇
  2016年   162篇
  2015年   127篇
  2014年   162篇
  2013年   220篇
  2012年   287篇
  2011年   267篇
  2010年   143篇
  2009年   138篇
  2008年   169篇
  2007年   209篇
  2006年   184篇
  2005年   175篇
  2004年   152篇
  2003年   81篇
  2002年   88篇
  2001年   15篇
  2000年   16篇
  1999年   12篇
  1998年   20篇
  1997年   16篇
  1996年   10篇
  1995年   11篇
  1994年   16篇
  1993年   13篇
  1992年   8篇
  1991年   4篇
  1990年   3篇
  1989年   9篇
  1988年   5篇
  1987年   6篇
  1986年   5篇
  1985年   2篇
  1984年   5篇
  1983年   4篇
  1980年   4篇
  1976年   5篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1971年   2篇
  1960年   1篇
  1958年   1篇
  1875年   1篇
排序方式: 共有3524条查询结果,搜索用时 792 毫秒
111.
OBJECTIVES: We sought to evaluate the mid-term outcome of hospital survivors with extracardiac Fontan circulation. BACKGROUND: Few data exist about the mid-term and long-term results of the extracardiac Fontan operation. METHODS: From November 1988 to November 2003, 221 patients underwent an extracardiac Fontan procedure as primary (9 patients) or secondary (212 patients) palliation, at a mean age of 72.2 months (range 13.1 to 131.3 months). A total of 165 of 193 early survivors underwent programmed noninvasive follow-up evaluations and at least one cardiac catheterization. RESULTS: The overall survival, including operative deaths, was 85% at 15 years. Freedom from late failure among hospital survivors is 92% at 15 years. A total of 127 of 165 survivors (77%) were in New York Heart Association functional class I. The incidence of late major problems was 24% (42 major problems in 36 of 165 patients): 19 patients had arrhythmias (11%), 5 patients had obstruction of the extracardiac conduit (3%) and 6 of the left pulmonary artery (3.5%), and 5 patients experienced ventricular failure (3%), leading to heart transplantation in 3 patients. Protein-losing enteropathy was found in two patients (1%). The incidence of late re-interventions was 12.7% (21 of 165 patients, including 15 epicardial pacemaker implantations). Four patients died (2.3%), two after heart transplantation. CONCLUSIONS: After 15 years of follow-up, the overall survival, the functional status, and the cardiopulmonary performance of survivors of the extracardiac Fontan procedure compare favorably with other series of patients who underwent the lateral tunnel approach. The incidence of late deaths, obstructions of the cavopulmonary pathway, re-interventions, and arrhythmias is lower than that reported late after other Fontan-type operations.  相似文献   
112.
OBJECTIVE: This study was designed to evaluate iodine deficiency status in children 6-12 years in the west coast (Aegean Region) of Turkey after 5 years of mandatory iodine prophylaxis. A total of 2300 children from 72 populations (rural and urban area) were evaluated with urinary iodine excretion and thyroid volume. DESIGN: Cross-sectional, observational study designed and performed according to surveillance methods for iodine deficiency disease (IDD) prevalence recommended by WHO/UNICEF/ICCIDD. SUBJECTS: The study population consisted of 2300 school children age ranging from 6 to 12 years. The children were selected by multiple stage randomization from 91 primary schools of 76 zones (91 clusters). Information about the use of iodized salt was obtained from the families. MEASUREMENTS: Data on the following were collected: birth date, sex, weight, height, thyroid size by palpation and ultrasonography; and urinary iodine by isotope dilution analysis method. Thyroid volumes above 97th percentile according to the WHO/ICCIDD by age and body surface area (BSA) were accepted as goitre. RESULTS: Iodized salt consumption was 51.7%. The prevalence of goitre determined by palpation was 12.1% and by ultrasound based on BSA and age were 9.8% and 5.5%, respectively. Median urinary iodine was 53 (2-142) microg/l. CONCLUSION: Mild to severe degree of iodine deficiency was detected in the west coast of Turkey.  相似文献   
113.
114.
115.
We assessed programmatic gaps that prevent the optimal treatment of pediatric HIV infection despite free antiretroviral care in Kenya. Of 626 HIV-infected Kenyan children, the median age was five years, 54% were male and the mortality rate was 3.2 per 100 person-years. A total of 380 (61%) children initiated antiretroviral therapy (ART) during the study period. Among the 246 children who never started ART, 129 (52%) met the criteria for ART initiation. Immunologic failure occurred in 20% of children who received ART for >24 weeks. In multivariate analysis, immunological failure was associated with having nonimmediate relative or unrelated caregivers accompanying the child to clinic (AOR = 69.16, p = 0.008). Having ≥3 types of accompanying caregivers was also associated with virologic failure in multivariate analysis (AOR = 3.84, p = 0.03). The lost to follow-up rate was 8.7/100 persons-years for the entire cohort, and significantly higher (17.7/100 persons-years) among children not on ART (p < 0.001). Among children who do initiate ART, those with the best treatment outcomes were those who had a limited number of close relatives as caregivers and good adherence to ART. Focus on early ART initiation and education of the right caregiver will likely improve retention and quality of pediatric HIV care in Kenya.  相似文献   
116.
Systemic sclerosis (SSc) is an autoimmune disease of unknown etiology characterized by progressive fibrosis. Activated fibroblasts are mainly responsible for fibrosis in SSc. Galectin-3, a β-galactoside-binding lectin, plays many important regulatory roles in both physiological and pathological processes including proliferation, apoptosis, inflammation, and fibrosis. The purpose of this study was to assess the serum galectin-3 levels in patients with SSc. Thirty-seven SSc patients, 23 systemic lupus erythematosus (SLE) patients (serving as patient control group), and 28 healthy volunteers were enrolled in this study. Disease activity and severity scores were detected with Valentini disease activity index and Medsger disease severity scale in the SSc group and SLE disease activity index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index in the SLE group. The serum levels of galectin-3, vascular endothelial growth factor, transforming growth factor-β, and interleukin-6 were determined. Compared to the control group, the galectin-3 levels were higher in the SSc and SLE groups. The galectin-3 levels were not correlated with the disease activity and severity indexes in both patient groups. But, the serum galectin-3 levels were higher in the active SSc and SLE subgroups than in the inactive SSc (4.6?±?5.8 vs. 1.3?±?1.1 ng/ml, p?=?0.015) and SLE (17.4?±?11.3 vs. 6.5?±?8.9 ng/ml, p?=?0.019) subgroups. These results suggest that galectin-3, which is associated with fibrosis and inflammation by previous studies, may be a prominent biomarker of disease activity in SSc.  相似文献   
117.
Metabolic Brain Disease - Diabetes mellitus is an increasing metabolic disease worldwide associated with central nervous system disorders. Coffee is a widely consumed beverage that enriched with...  相似文献   
118.

Purpose

In patients who are hospitalized for surgery, anxiety disorders are frequently observed. Anxiety affects the patient’s perception of postoperative pain and has a negative impact on recovery from anesthesia. This study attempted to compare the effect of preoperative anxiety on postoperative pain control and recovery from anesthesia in patients undergoing laparoscopic cholecystectomy.

Methods

A total of 80 patients were enrolled who were undergoing laparoscopic cholecystectomy. Demographic characteristics of the patients were recorded. Beck’s anxiety ?nventory (BAI) was administered to the patients: patients with anxiety were included in the high-anxious patient group (group H) and patients without anxiety were enrolled in the low-anxious group (group L). Duration of surgery, duration of anesthesia, extubation time, and adverse effects were recorded. During the postoperative period, patient-controlled analgesia with tramadol was used for pain control. Visual analog scale (VAS) scores and tramadol consumption of all patients were recorded.

Results

Among all patients, 31 (38.75 %) patients had preoperative anxiety, and significant correlation was found between the days of hospitalization and preoperative score of BAI. In group L, extubation time, the time for the modified Aldrete score to reach 9, was seen as significantly shorter and fewer postoperative side effects were determined. Also in group L, postoperative VAS score and tramadol consumption were significantly lower, and less tenoxicam was needed.

Conclusion

A high preoperative anxiety level negatively affects recovery from anesthesia and control of postoperative pain. In this patient group, the increased need for postoperative analgesia must be adequately met.  相似文献   
119.
120.
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