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   55499篇
  免费   3300篇
  国内免费   596篇
耳鼻咽喉   980篇
儿科学   639篇
妇产科学   833篇
基础医学   9667篇
口腔科学   1345篇
临床医学   4863篇
内科学   10365篇
皮肤病学   1861篇
神经病学   3941篇
特种医学   2954篇
外科学   7466篇
综合类   211篇
现状与发展   1篇
一般理论   17篇
预防医学   2652篇
眼科学   1221篇
药学   4962篇
中国医学   624篇
肿瘤学   4793篇
  2023年   298篇
  2022年   923篇
  2021年   2061篇
  2020年   986篇
  2019年   1288篇
  2018年   1671篇
  2017年   1243篇
  2016年   1760篇
  2015年   2562篇
  2014年   3064篇
  2013年   3494篇
  2012年   5321篇
  2011年   4816篇
  2010年   2807篇
  2009年   2365篇
  2008年   3421篇
  2007年   3099篇
  2006年   2655篇
  2005年   2353篇
  2004年   2026篇
  2003年   1697篇
  2002年   1439篇
  2001年   1363篇
  2000年   1262篇
  1999年   906篇
  1998年   362篇
  1997年   250篇
  1996年   208篇
  1995年   176篇
  1994年   148篇
  1993年   132篇
  1992年   332篇
  1991年   316篇
  1990年   280篇
  1989年   258篇
  1988年   247篇
  1987年   248篇
  1986年   177篇
  1985年   165篇
  1984年   119篇
  1983年   111篇
  1982年   55篇
  1981年   58篇
  1979年   81篇
  1978年   68篇
  1975年   50篇
  1974年   60篇
  1973年   51篇
  1972年   50篇
  1970年   49篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
Digital cardiovascular angiography accounts for a major portion of the radiation dose among the examinations performed at cardiovascular centres. However, dose-related information is neither monitored nor recorded systemically. This report concerns the construction of a radiation dose monitoring system based on digital imaging and communications in medicine (DICOM) data and its use at the cardiovascular centre of the University Hospitals in Korea. The dose information was analysed according to DICOM standards for a series of procedures, and the formulation of diagnostic reference levels (DRLs) at our cardiovascular centre represents the first of its kind in Korea. We determined a dose area product (DAP) DRL for coronary angiography of 75.6 Gy cm2 and a fluoroscopic time DRL of 318.0 s. The DAP DRL for percutaneous transluminal coronary intervention was 213.3 Gy cm2, and the DRL for fluoroscopic time was 1207.5 s.  相似文献   
982.
This study was conducted to assess the association between sarcopenic obesity and cardiovascular disease (CVD) risk in Korean adults (n=3,320; ≥40 yr) who participated in the 5th Korean National Health and Nutrition Examination Survey in 2010. The appendicular skeletal muscle mass divided by body weight was calculated for each participant; participants with values <1 standard deviation below the mean reference value (i.e., aged 20-39 yr) were considered sarcopenic. Subjects were further classified into 4 groups according to their obesity (i.e., body mass index ≥25 kg/m2) and sarcopenic status. Individuals'' 10-yr CVD risk was determined using the Framingham risk model. The sarcopenic obese group had more participants (43.8% men, 14.6% women) with a high risk of CVD (≥20%). The sarcopenic obese group was associated with an increased 10-yr CVD risk than the non-sarcopenic, non-obese group (odds ratio [OR], 2.49; 95% confidence interval [CI], 1.53-4.06, P<0.001 in men; OR, 1.87; 95% CI, 1.02-3.41, P=0.041 in women). Sarcopenic non-obese and non-sarcopenic obese subjects were not associated with an increased 10-yr CVD risk. Sarcopenic obesity, but not non-sarcopenic obesity, was closely associated with an increased CVD risk in Korean adults.

Graphical Abstract

相似文献   
983.
The geriatric population is increasing, and asthma severity increases with age. We determined the predictors of asthma control, exacerbation, and the factors that affect asthma-specific quality of life (A-QOL) in elderly asthmatic patients. This was a prospective, multicenter, real-life study for 6 months with stepwise pharmacologic treatment based on the Global Initiative for Asthma (GINA) guideline. A total of 296 asthmatic patients aged ≥ 60 yr were recruited from 5 university centers in Korea. The improved-asthma control group was defined as the group of patients who maintained well-controlled or improved disease and the not-improved asthma control group was defined as the remaining patients. Fewer number of medications for comorbidities (2.8 ± 3.3 in the improved vs. 4.5 ± 4.4 in the control) and higher physical functioning (PF) scale (89.8 ± 14.2 in the improved vs. 82.0 ± 16.4 in the control) were significant predictors in the improved-asthma control group (OR = 0.863, P = 0.004 and OR = 1.028, P = 0.018, respectively). An asthma control test (ACT) score of ≤ 19 at baseline was a significant predictor of asthma exacerbation (OR = 3.938, P = 0.048). Asthma duration (F = 5.656, P = 0.018), ACT score (F = 12.237, P = 0.001) at baseline, and the presence of asthma exacerbation (F = 5.565, P = 0.019) were significant determinants of changes in A-QOL. The number of medications for comorbidities and performance status determined by the PF scale may be important parameters for assessing asthma control in elderly asthmatic patients.

Graphical Abstract

相似文献   
984.
The study aimed to verify the prognostic utility, therapeutic application and clinical benefits of tumor substaging and HER2 status in papillary non-muscle invasive bladder cancer (NMIBC). Select NMIBC transurethral resection specimens from 141 patients were used to construct tissue microarrays for assessing the substaging, HER2 protein expression by immunohistochemistry (HER2-IHC) and gene amplification by dual-color silver in situ hybridization (HER2-SISH). Substages were identified by the differing depth of tumor invasion (pTa / pT1a / pT1b / pT1c). HER2 protein expression was semiquantitatively analyzed and grouped into negative (score 0, 1+) and positive (score 2+, 3+). Other clinicopathological variables were also investigated. For NMIBC, HER2-IHC and HER2-SISH showed positive results in 6/141 (4.3%) and 4/141 (2.8%) respectively, which correlated well with tumor substaging. In multivariate analysis, substaging, HER2-IHC, and HER2-SISH were found to be independent predictors of progression-free survival (P < 0.001, P < 0.001, P = 0.031). HER2-IHC was the sole independent predictor of recurrent free survival in NMIBC (P = 0.017). It is suggested that tumor substaging and HER2 status are independent predictive markers for tumor progression or recurrence, and thus could be included in diagnostic and therapeutic management for NMIBC.

Graphical Abstract

相似文献   
985.
The purpose of the present study was to investigate the relationship between Korean language-specific dysgraphia and unilateral spatial neglect in 31 right brain stroke patients. All patients were tested for writing errors in spontaneous writing, dictation, and copying tests. The dysgraphia was classified into visuospatial omission, visuospatial destruction, syllabic tilting, stroke omission, stroke addition, and stroke tilting. Twenty-three (77.4%) of the 31 patients made dysgraphia and 18 (58.1%) demonstrated unilateral spatial neglect. The visuospatial omission was the most common dysgraphia followed by stroke addition and omission errors. The highest number of errors was made in the copying and the least was in the spontaneous writing test. Patients with unilateral spatial neglect made a significantly higher number of dysgraphia in the copying test than those without. We identified specific dysgraphia features such as a right side space omission and a vertical stroke addition in Korean right brain stroke patients. In conclusion, unilateral spatial neglect influences copy writing system of Korean language in patients with right brain stroke.

Graphical Abstract

相似文献   
986.
Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play crucial roles in a variety of diseases, including autoimmunity, infectious diseases, and cancers. However, little is known about the roles of these invariant T cells in acute cholecystitis. The purposes of this study were to examine the levels of MAIT cells and NKT cells in patients with acute cholecystitis and to investigate potential relationships between clinical parameters and these cell levels. Thirty patients with pathologically proven acute cholecystitis and 47 age- and sex-matched healthy controls were enrolled. Disease grades were classified according to the revised Tokyo guidelines (TG13) for the severity assessment for acute cholecystitis. Levels of MAIT and NKT cells in peripheral blood were measured by flow cytometry. Circulating MAIT and NKT cell numbers were significantly lower in acute cholecystitis patients than in healthy controls, and these deficiencies in MAIT cells and NKT cell numbers were associated with aging in acute cholecystitis patients. Notably, a reduction in NKT cell numbers was found to be associated with severe TG13 grade, death, and high blood urea nitrogen levels. The study shows numerical deficiencies of circulating MAIT and NKT cells and age-related decline of these invariant T cells. In addition, NKT cell deficiency was associated with acute cholecystitis severity and outcome. These findings provide an information regarding the monitoring of these changes in circulating MAIT and NKT cell numbers during the course of acute cholecystitis and predicting prognosis.  相似文献   
987.
The purpose of this report was to provide information for patients receiving inpatient rehabilitation after stroke and to identify the possible factors influencing functional outcome after inpatient rehabilitation. Stroke patients (n = 5,212) who were discharged from the Departments of Rehabilitation Medicine (RM) of university hospitals and rehabilitation hospitals from 2007 through 2011 were participants. Prevalence, age, transfer time after onset, length of stay (LOS), functional status at admission and discharge were analyzed. In all stroke subjects, cerebral infarctions (67%) were more common than hemorrhages. Cerebral infarctions in the middle cerebral artery territory were most common, while the basal ganglia and cerebral cortex were the most common areas for hemorrhagic stroke. The LOS decreased from 45 to 28 days. Transfer time after onset decreased from 44 to 30 days. Shorter transfer time after onset was correlated with better discharge functional status and shorter LOS. Initial functional status was correlated with discharge functional status. In ischemic stroke subtypes, cerebellar and brainstem strokes predicted better outcomes, while strokes with more than one territory predicted poorer outcomes with more disabilities. In hemorrhagic stroke subtypes, initial and discharge functional status was the lowest for cortical hemorrhages and highest for brainstem hemorrhages. This report shows that LOS and transfer time after onset has been decreased over time and initial functional status and shorter transfer after onset are predictors of better functional outcome at discharge.  相似文献   
988.
This research aimed to investigate the changes in ethical issues in everyday clinical practice recognized by critical care nurses during two observation periods. We conducted a retrospective analysis of data obtained by prospective questionnaire surveys of nurses in the intensive care units (ICU) of a tertiary university-affiliated hospital in Seoul, Korea. Data were collected prospectively during two different periods, February 2002-January 2003 (Period 1) and August 2011-July 2012 (Period 2). Significantly fewer cases with ethical issues were reported in Period 2 than in Period 1 (89 cases [2.1%] of 4,291 ICU admissions vs. 51 [0.5%] of 9,302 ICU admissions, respectively; P < 0.001). The highest incidence of cases with identified ethical issues in both Periods occurred in MICU. The major source of ethical issues in Periods 1 and 2 was behavior-related. Among behaviorrelated issues, inappropriate healthcare professional behavior was predominant in both periods and mainly involved resident physicians. Ethical issue numbers regarding end-oflife (EOL) care significantly decreased in the proportion with respect to ethical issues during Period 2 (P = 0.044). In conclusion, the decreased incidence of cases with identified ethical issues in Period 2 might be associated with ethical enhancement related with EOL and improvements in the ICU care environment of the studied hospital. However, behaviorrelated issues involving resident physicians represent a considerable proportion of ethical issues encountered by critical care nurses. A systemic approach to solve behavior-related issues of resident physicians seems to be required to enhance an ethical environment in the studied ICU.

Graphical Abstract

相似文献   
989.
Radon is likely the second most common cause of lung cancer after smoking. We estimated the lung cancer risk due to radon using common risk models. Based on national radon survey data, we estimated the population-attributable fraction (PAF) and the number of lung cancer deaths attributable to radon. The exposure-age duration (EAD) and exposure-age concentration (EAC) models were used. The regional average indoor radon concentration was 37.5 95 Bq/m3. The PAF for lung cancer was 8.3% (European Pooling Study model), 13.5% in males and 20.4% in females by EAD model, and 19.5% in males and 28.2% in females by EAC model. Due to differences in smoking by gender, the PAF of radon-induced lung cancer deaths was higher in females. In the Republic of Korea, the risk of radon is not widely recognized. Thus, information about radon health risks is important and efforts are needed to decrease the associated health problems.

Graphical Abstract

相似文献   
990.
The aim of this study was to investigate the whole picture regarding pregnancy, prenatal care, obstetrical complications, and delivery among disabled pregnant women in Korea. Using the data of National Health Insurance Corporation, we extracted the data of women who terminated pregnancy including delivery and abortion from January 1, 2010 to December 31, 2010. Pearson''s chi-square test and Student-t test were conducted to examine the difference between disabled women and non-disabled women. Also, to define the factors affecting inadequate prenatal care, logistic regression was performed. The total number of pregnancy were 463,847; disabled women was 2,968 (0.6%) and 460,879 (99.4%) were by non-disabled women. Abortion rates (27.6%), Cesarean section rate (54.5%), and the rate of receiving inadequate prenatal care (17.0%), and the rate of being experienced at least one obstetrical complication (11.3%) among disabled women were higher than those among non-disabled women (P < 0.001). Beneficiaries of Medical Aid (OR, 2.21) (P < 0.001) and severe disabled women (OR, 1.46) (P = 0.002) were more likely to receive inadequate prenatal care. In conclusion, disabled women are more vulnerable in pregnancy, prenatal care and delivery. Therefore, the government and society should pay more attention to disabled pregnant women to ensure they have a safe pregnancy period up until the delivery.

Graphical Abstract

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