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   7835篇
  免费   544篇
  国内免费   128篇
耳鼻咽喉   112篇
儿科学   169篇
妇产科学   116篇
基础医学   1260篇
口腔科学   197篇
临床医学   553篇
内科学   1650篇
皮肤病学   289篇
神经病学   775篇
特种医学   350篇
外科学   918篇
综合类   39篇
一般理论   1篇
预防医学   561篇
眼科学   246篇
药学   609篇
中国医学   120篇
肿瘤学   542篇
  2024年   6篇
  2023年   65篇
  2022年   147篇
  2021年   278篇
  2020年   138篇
  2019年   239篇
  2018年   298篇
  2017年   230篇
  2016年   314篇
  2015年   423篇
  2014年   455篇
  2013年   507篇
  2012年   804篇
  2011年   769篇
  2010年   480篇
  2009年   372篇
  2008年   539篇
  2007年   470篇
  2006年   422篇
  2005年   381篇
  2004年   333篇
  2003年   253篇
  2002年   249篇
  2001年   49篇
  2000年   40篇
  1999年   40篇
  1998年   27篇
  1997年   19篇
  1996年   10篇
  1995年   18篇
  1994年   11篇
  1993年   11篇
  1992年   14篇
  1991年   17篇
  1990年   10篇
  1989年   5篇
  1988年   7篇
  1987年   6篇
  1986年   11篇
  1984年   5篇
  1983年   3篇
  1982年   4篇
  1981年   2篇
  1979年   3篇
  1978年   2篇
  1977年   3篇
  1975年   2篇
  1971年   2篇
  1969年   2篇
  1965年   2篇
排序方式: 共有8507条查询结果,搜索用时 0 毫秒
41.
Abstract Background: Microalbuminuria has been shown to be predictive for clinical diabetic nephropathy. Renal functional reserve (RFR), as a response to protein loading in a short period of time, is a parameter to assess the ability of kidneys to increase the glomerular filtration rate (GFR). The aim of this study was to predict the early phase of diabetic nephropathy by measuring urinary albumin level and RFR capacity in patients with insulin-dependent diabetes mellitus (IDDM).
Methods: Twenty-two patients with IDDM were studied: 11 with a disease duration of less than 5 years (group 1) and 11 with a disease duration of more than 5 years (group 2). As the control group, 15 healthy children (group 3) were included in the study. At the beginning of the study, glucose was measured and the urinary albumin/creatinine ratio was calculated. Average glycosylated hemoglobin (HbA1c) over 1 year was determined. After protein loading (red meat containing 2 g/kg of protein), the creatinine clearance was calculated at each hour for a duration of 4 h. The RFR was accepted as the peak percentage increase in GFR over the baseline value.
Results: Although metabolic control in group 2 was better, the RFR in group 2 was significantly lower than in group 1 (P < 0.05). Urinary microalbumin levels between the groups did not differ (P < 0.05). In two patients in whom microalbuminuria was detected, the RFR was much lower.
Conclusions: Detecting lower RFR levels in patients with normal urinary albumin excretion, as well as in patients with microalbuminuria, may support the idea that the RFR capacity is more sensitive than microalbuminuria in assessing the early phase of diabetic nephropathy.  相似文献   
42.
It is known that approximately 10% of successful quitters relapse annually. This study aimed to investigate the factors related to long-term smoking relapse in individuals who succeeded in maintaining smoking cessation for 6 months after attending a regional smoking cessation program.This study enrolled 943 individuals registered for the regional smoking cessation program at the Busan Smoking Cessation Center in 2018–2019 who maintained smoking cessation for 6 months. A survey was conducted using a smartphone link or through phone calls, and the data for 305 participants who finally completed the survey were analyzed. The questionnaire addressed individual, inter-individual, organizational, and community-level factors related to smoking relapse. Multivariate logistic regression analysis was performed to evaluate the factors associated with smoking relapse by period. The Cox proportional hazard regression model was used for the factors associated with smoking relapse for the entire period.The smoking relapse rate at the time of the survey was 25.4%. In the analysis of smoking relapse by period, relapse was associated with the belief that smoking relieves stress, the number of single-person households, and poor subjective health status. In the analysis of smoking relapse during the entire period, we observed a significant association with the belief that smoking relieves stress (hazard ratio [HR]: 2.65, 95% confidence interval [CI]: 1.52–4.61), single-person households (HR: 1.95, 95% CI: 1.16–3.26), and high levels of emotional stress (HR: 1.72, 95% CI: 1.04–2.85).Long-term follow-up is necessary to prevent smoking relapse in single-person households, individuals who believe that smoking relieves stress, and those experiencing high levels of subjective emotional stress. Interventional therapies for stress relief and awareness improvement in smokers need to be developed.  相似文献   
43.
44.
OBJECTIVES: This study examines whether expression of COX-2 is associated with clinicopathological features and other molecular markers of ovarian cancer. METHODS: Sixty-four paraffin-embedded tissue specimens were obtained from patients with ovarian cancer who received cytoreductive surgery and combination chemotherapy. Tissue specimens were subjected to immunohistochemical analysis using antibodies to COX-2, p53, and VEGF. RESULTS: Increased COX-2 expression significantly correlated with histologic type (mucinous 5.6% vs. non-mucinous 65.2%, P<0.001). COX-2 expression was also significantly associated with stage, tumor grade, residual disease status, and presence of ascites. COX-2 expression correlated positively with expression of p53 (P=0.006) and VEGF (P=0.025). Although survival was lower in patients with high COX-2 expression than in those without high COX-2 expression (P<0.001), only tumor grade and stage were independent prognostic indicators. In patients with non-mucinous cancer, COX-2 expression correlated with stage (P<0.001) and presence of ascites (P=0.033). CONCLUSIONS: Our results suggest that expression of COX-2 in ovarian cancers is specific to histologic type of tumor and is associated with poor clinicopathologic prognostic factors. Expression of COX-2 also correlates well with expression of p53 and VEGF.  相似文献   
45.
BackgroundWe investigated the association between individual components of metabolic syndrome (MetS) and left ventricular (LV) geometric changes, including diastolic dysfunction, in a large cohort of healthy individuals.MethodsOverall, 148 461 adults who underwent echocardiography during a health‐screening program were enrolled. Geographic characteristics on echocardiography and several markers of LV relaxation function were identified according to individual MetS components. Univariate linear regression analysis and a multivariate regression model adjusted for factors known to influence LV relaxation function were conducted.ResultsThe prevalence of LV diastolic dysfunction (LVDD) was higher in the MetS group than in the non‐MetS group (0.56% vs. 0.27%, p < .001). In univariate and multivariate analyses, E/A ratio, e′ velocity, and left atrial volume index were significantly associated with each component of MetS and covariates (all p ≤ .001). In the age‐ and sex‐adjusted model, MetS was significantly associated with LVDD (odds ratio [95% confidence interval], 1.350 [1.103, 1.652]). However, subjects with more MetS components did not have a significantly higher risk of LVDD. As the analysis was stratified by sex, the multivariate regression model showed that MetS was significantly associated with LVDD only in men (1.3 [1.00, 1.68]) with higher risk in more MetS component (p for trend < .001). In particular, triglyceride (TG) and waist circumference (WC) among MetS components were significantly associated with LVDD in men.ConclusionsMetS was associated with the risk of LVDD, especially in men, with a dose‐dependent association between an increasing number of components of MetS and LVDD. TG and WC were independent risk factors for LVDD in men.  相似文献   
46.
47.
48.
A 32-year-old woman at 17 weeks of gestation had a high possibility (1:82) of having a child with Down syndrome. Fetal chromosome according to amniocentesis revealed 46,XX,del(7)(q11.23q21.2). The fetus' chromosomal defect was not inherent because the chromosome analysis of the parents did not have any abnormal findings. We were regularly monitoring the pregnant woman by routine prenatal schedule and she had a normal spontaneous delivery. The baby showed a typical facial malformation, epicanthal fold, decreased muscle tone, and cardiac abnormalities. This is the first patient prenatally diagnosed with de novo 7q deletion by positive triple marker screening test. We consider the triple test, which is the most popular examination used to clarify the risk of chromosome abnormality in obstetrics, will be used not only for trisomy 21 and 18, but also for any other chromosome abnormalities.  相似文献   
49.
OBJECTIVE: To evaluate the potential benefit of postoperative radiotherapy (PORT) in women with isolated full-thickness cervical stromal invasion (FTSI) as an unfavorable pathological finding after radical hysterectomy and pelvic lymph node dissection (PLND) in FIGO stages IB-IIA cervical carcinoma. METHODS: A total of 1868 patients with stages IB-IIA cervical carcinoma underwent radical hysterectomy and PLND between January 1982 and December 2002. Seventy-four of these patients had isolated FTSI without any other unfavorable pathological finding, such as lymph node metastasis, microscopic parametrial involvement, involved resection margin, lympho-vascular space invasion, or large clinical tumor diameter (>4 cm). Forty-one of these patients had no adjuvant treatment (S group) and 33 received PORT (PORT group). Patients with isolated FTSI who received chemotherapy were excluded. Treatment outcomes in the PORT and S groups were compared. RESULTS: Ten-year disease-free survival (DFS) and pelvic-failure-free survival (PFFS) of S group vs. PORT group were 73.2% vs. 92.4% (P=0.038) and 79.8% vs. 97.0% (P=0.044), respectively. According to a Cox proportional hazards model developed by forward, stepwise regression incorporating all prognostic variables, only PORT was marginally significant for DFS (RR 0.234; 95% CI 0.051-1.067; P=0.061) and significant for PFFS (RR 0.055; 95% CI 0.005-0.620; P=0.019). A grade 4 late complication developed in two patients (6%) in PORT group. CONCLUSION: PORT administered to patients with isolated FTSI after radical hysterectomy and PLND improves pelvic control in FIGO stages IB-IIA cervical carcinoma with acceptable morbidity.  相似文献   
50.
The roles of social workers in hospitals have changed in accordance with the environmental changes in the healthcare system. Since 1958, hospital social workers have performed important roles in providing care services in South Korea. Providing psychosocial services was considered to be the most important for more than 30 years from the 1970s to the 1990s. The healthcare system has since undergone major environmental changes, yet there has been little study on the role of hospital social workers in South Korea. In order to address this research gap, this study aims to explore how the roles of hospital social workers have changed since the 2000s. We recruited 198 hospital social workers who were active members of the Korean Association of Medical Social Workers as study participants. The average age of participants was 35.36 years old (SD = 8.27), and they had an average of 8.24 years in hospital social work experience (SD = 6.35). The results indicated that the roles of financial support and community resource linkage, which were regarded to be relatively less important until the 1990s, were recognized as the most important. Given the role changes of hospital social workers in South Korea, implications are discussed.  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