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   925篇
  免费   42篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   46篇
妇产科学   26篇
基础医学   114篇
口腔科学   7篇
临床医学   47篇
内科学   190篇
皮肤病学   6篇
神经病学   68篇
特种医学   31篇
外科学   223篇
综合类   3篇
预防医学   38篇
眼科学   10篇
药学   56篇
中国医学   2篇
肿瘤学   99篇
  2024年   2篇
  2023年   5篇
  2022年   6篇
  2021年   24篇
  2020年   10篇
  2019年   14篇
  2018年   20篇
  2017年   13篇
  2016年   26篇
  2015年   23篇
  2014年   34篇
  2013年   31篇
  2012年   40篇
  2011年   48篇
  2010年   33篇
  2009年   37篇
  2008年   49篇
  2007年   58篇
  2006年   57篇
  2005年   69篇
  2004年   43篇
  2003年   53篇
  2002年   48篇
  2001年   25篇
  2000年   21篇
  1999年   17篇
  1998年   8篇
  1997年   7篇
  1996年   7篇
  1995年   4篇
  1994年   9篇
  1993年   8篇
  1992年   8篇
  1991年   4篇
  1990年   6篇
  1989年   6篇
  1988年   13篇
  1987年   14篇
  1986年   11篇
  1985年   11篇
  1984年   7篇
  1983年   9篇
  1981年   2篇
  1980年   5篇
  1979年   6篇
  1978年   2篇
  1972年   3篇
  1971年   2篇
  1970年   3篇
  1963年   1篇
排序方式: 共有968条查询结果,搜索用时 31 毫秒
871.
"ULUUS" is a patent medicine which was put on sale when the Japanese started to adopt Western Medicine brought in from Holland. It is regarded as the first medicine to have a Western-style name in Japan. In those days, ULUUS was thought be a useful medicine for patients with diseases called Tan, Ryuin and Shakki, causing the excretion of phlegm and bad accumulations in the body through expectoration, urine of feces. We recently obtained an ULUUS medication which was made in around 1870. It contains 15 tablets pressed neatly onto a sheet and has an inner wrapper, middle wrapper and outer wrapper made from 3 kinds of Japanese paper...  相似文献   
872.
Hepatitis B virus (HBV) has seven genotypes, A to G. Previous studies have shown that genotype C is the most prevalent strain in chronic HBV carriers in East Asia. This study was undertaken to investigate the epidemiology of HBV genotypes among Japanese patients who are coinfected with human immunodeficiency virus type 1 (HIV-1). The sequences of the complete hepatitis B surface antifen (HBsAg) genes were obtained from 18 coinfected Japanese patients. Among the 18 patients, 12 of 13 men who had sex with men (MSM) had genotype A (92%), whereas only one of five heterosexual or hemophiliac patients had genotype A. The predominance of genotype A HBV in MSM showed a striking contrast to the current genotype prevalence in the Japanese population. Owing to the recent decrease in the rate of vertical transmission in Japan, the role of sexual behavior in the transmission of HBV cannot be overestimated. Thus, the relative proportion of genotype A may gradually increase in Japan.  相似文献   
873.
Hydrophilic-hydrophobic multiblock copolymers synthesized from telechelic oligomers of poly(ethylene oxide) (PEO) and polystyrene (PS) have been used to study the influence of hydrophilic and hydrophobic balance on interfacial interactions of these surfaces with blood components. In vitro coagulation assays show no inherent ability of these amphiphilic surfaces to affect contact activation or coagulation factors. In vitro platelet adhesion and release reactions from rabbit platelet-rich plasma were shown to be greatest on Biomer and PS homopolymer surfaces and least on cross-linked PEO surfaces, with the PEO-PS block copolymers demonstrating intermediate responses. These same substrates were tested in a new low-flow, low-shear arterio-artery shunt system in rabbits. Whole blood occlusion times were not a direct function of hydrophilic content as both PEO and PS homopolymers and Biomer showed short occlusion times, while PEO-PS block copolymers prolonged occlusion times considerably, depending on composition. Overall, results suggest that PEO-PS block copolymers promote unique whole blood responses in contrast to homopolymer and Biomer controls which are more complex than direct correlations to bulk hydrophilic and hydrophobic contents.  相似文献   
874.
875.
BACKGROUND: Recent studies have revealed that HBV may not be cleared even after the disappearance of serum HBsAg. The purpose of this study was to investigate whether the replication of HBV persists in HBsAg-negative blood donors who lack apparent liver disease. STUDY DESIGN AND METHODS: Serum HBV was examined by using PCR coupled with Southern blotting in 50 blood donors who were identified to be HBsAg negative but anti-HBc positive. RESULTS: HBV DNA was detected in the sera from 19 (38%) of 50 donors. In 11 of the 19, HBV existed exclusively as immune complexes, while HBV presumably did not exist as immune complexes in the remaining eight. The levels of HBV DNA were similar to those in patients who had recovered from acute HBV. Some nucleotide substitutions, which did not confer amino acid changes in the major epitope of HBsAg, were found in the preS-S regions. CONCLUSION: The replication of HBV is ongoing in a substantial proportion of healthy blood donors who have anti-HBc. Blood from such donors may contain very low levels of HBV free of immune complex formation and should be excluded for transfusion. The fact that such blood donors apparently lacked liver disease suggests no pathogenicity of such "occult" HBV.  相似文献   
876.
Several screening methods for reducing the mortality rate of colorectal cancer (CRC) have been reported in recent decades. Fecal occult blood tests (FOBTs) are widely used for CRC screening and immunochemical FOBTs perform better than guaiac FOBTs; however, the sensitivity and specificity of immunochemical FOBTs remain unsatisfactory. To resolve this problem, novel fecal molecular methods based on fecal protein, DNA and RNA analyses have been developed. Regarding fecal proteins, several marker proteins indicating intestinal bleeding and cancer cell-specific proteins have been investigated. Regarding fecal DNA, numerous gene mutation and gene methylation analyses have been reported. Consequently, fecal DNA analysis was recommended as a CRC screening method in 2008. In addition, gene expression analyses of CRC-specific genes and miRNAs in fecal RNA have been investigated over the last decade. This review article summarizes molecular methods using fecal samples for CRC screening, focusing on reports within the last 5 years.  相似文献   
877.
The aim of this study was to investigate the relationships between insulin resistance and regional abdominal fat area, body mass index (BMI), and serum lipid profile in nonobese Japanese type 2 diabetic patients. A total of 63 nonobese Japanese type 2 diabetic patients aged 45 to 83 years were examined. The duration of diabetes was 8.4 +/- 0.8 years. BMI, glycosylated hemoglobin (HbA(1c)) levels, and fasting concentrations of plasma glucose, serum lipids (total cholesterol, high-density lipoprotein [HDL] cholesterol, and triglycerides), and serum insulin were measured. The low-density lipoprotein (LDL) cholesterol level was calculated using the Friedewald formula (LDL cholesterol = total cholesterol - HDL cholesterol - 1/5 triglycerides). Insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). Computed tomography (CT) was used to measure cross-sectional abdominal subcutaneous and visceral fat areas in all the patients. Adipose tissue areas were determined at the umbilical level. Subcutaneous and visceral abdominal fat areas were 136.5 +/- 6.0 and 86.0 +/- 4.1 cm(2), respectively. Univariate regression analysis showed that insulin resistance was positively correlated with subcutaneous (r =.544, P <.001) and visceral (r =.408, P =.001) fat areas, BMI (r =.324, P =.009), HbA(1c) (r =.254, P =.001), serum triglycerides (r =.419, P <.001), and serum LDL cholesterol (r =.290, P =.019) levels and was negatively correlated with serum HDL cholesterol level (r =.254, P =.041). Multiple regression analyses showed that insulin resistance was independently predicted by the areas of subcutaneous (F = 6.76, P <.001) and visceral (F = 4.61, P <.001) abdominal fat and serum triglycerides (F = 8.88, P <.001) level, which explained 36.9% of the variability of insulin resistance. Moreover, the present study demonstrated that whereas BMI was positively correlated with visceral (r =.510, P <.001) and subcutaneous (r =.553, P <.001) fat areas, serum triglyceride level was positively associated with visceral (r =.302, P =.015), but not with subcutaneous (r =.222, P =.074) fat area. From these results, it can be suggested that (1) both subcutaneous and visceral abdominal fat areas are independently associated with insulin resistance and (2) visceral fat area, but not the subcutaneous one, is associated with serum triglyceride levels in our nonobese Japanese type 2 diabetic patients.  相似文献   
878.
This is a report of hemolytic anemia and respiratory failure due to Mycopkisma pneumoniae pneumonia. His chest CT scans showed bilateral diffuse thickened bronchovascular bundles and emphysematous changes. The pulmonary function test supported the diagnosis of chronic obstructive pulmonary disease (COPD). He was diagnosed as coldagglunitin-associated hemolytic anemia and M. pneumonzae pneumonia in inapparent COPD. Corticosteroid administration was remarkabily effective for hemolytic anemia and beneficial for acute exacerbation of COPD.  相似文献   
879.
The incidence of lower urinary tract symptoms (LUTS) in people consulting general practitioners (GPs) was investigated. We used a questionnaire including seven questions regarding LUTS and one question regarding bothersomeness based on the International Prostate Symptom Score (I-PSS), three questions on the Overactive Bladder Symptom Score (OABSS) and four questions on the International Consultation on Incontinence Questionnaire Short-Form (ICIQ-SF), and conducted the survey among 1120 people aged 50 or older who consulted 17 GP clinics. Of 958 persons (86%) who responded the questionnaires, we analyzed the data from 822 (73%) who completed all the above questions. There were 364 men (mean age, 67 years) and 458 women (mean age, 68 years). Moderate or severe grades in I-PSS and OABSS were indicated in 99 (27%) and 43 (12%), for men, respectively, and 55 (12%) and 39 (9%) for women, respectively. I-PSS correlated with age in men and OABSS did in both genders. Most people with moderate or severe I-PSS experienced moderate or severe bothersomeness. Fifty-five (15%) men and 185 (40%) women indicated that they had some type of urinary incontinence. There were 138 (38%) men and 165 (36%) women showing both moderate or severe I-PSS, and moderate or severe bothersomeness, and/or with an ICIQ-SF score of 1 or greater. Approximately one-third of men and women aged 50 or older consulting GPs have bothersome LUTS, including urinary incontinence. We believe that they should be carefully assessed to determine whether they need treatment.  相似文献   
880.
The possible involvement of oxidative damage in the progression of atherosclerosis has been suggested. There is some evidence that antioxidant therapy may be beneficial for the prevention of coronary heart disease. In this study, we investigated the relationship between coronary artery disease (CAD) and serum antioxidative status by measuring the total antioxidant status (TAS). Other relevant antioxidants, such as retinol, alpha, gamma-tocopherol, ascorbic acid, alpha, beta-carotenoids, erythrocyte glutathione peroxidase (GSH-Px) and oxidative products, were also determined in 31 male CAD patients with angiographically defined CAD and 66 male controls, aged 40-70 years, in a case-control study. The TAS levels, ratio and the concentrations of retinol, albumin, total protein and HDL cholesterol were significantly lower in the CAD patients than in the controls (p<0.01), and alpha-tocopherol and alpha/gamma-tocopherol were significantly higher in the CAD patients than in the controls. The TAS level correlated positively with gamma-GTP, GPT, GOT and uric acid (p<0.01). A multiple regression analysis in the CAD patients revealed that the TAS levels correlated most negatively with the number of diseased vessels. The concentrations of carotenoids and GSH-Px, as well as the alpha/gamma-tocopherol ratio were also significantly associated. Although conditional logistic regression analysis suggested low levels of HDL-cholesterol to be a significant coronary risk factor (OR=5.1, 95% CI=1.09-24.3), the TAS level showed no significant independent contribution to CAD. This study demonstrated an association of antioxidant parameters with the atherosclerosis progression, however, it did not confirm antioxidants as an independent risk factor for CAD event.  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