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   1966篇
  免费   72篇
  国内免费   12篇
耳鼻咽喉   23篇
儿科学   15篇
妇产科学   26篇
基础医学   196篇
口腔科学   35篇
临床医学   90篇
内科学   490篇
皮肤病学   58篇
神经病学   164篇
特种医学   100篇
外科学   336篇
综合类   16篇
预防医学   66篇
眼科学   4篇
药学   167篇
中国医学   3篇
肿瘤学   261篇
  2023年   12篇
  2022年   40篇
  2021年   67篇
  2020年   37篇
  2019年   36篇
  2018年   53篇
  2017年   44篇
  2016年   36篇
  2015年   40篇
  2014年   49篇
  2013年   63篇
  2012年   124篇
  2011年   155篇
  2010年   72篇
  2009年   68篇
  2008年   119篇
  2007年   154篇
  2006年   117篇
  2005年   131篇
  2004年   126篇
  2003年   114篇
  2002年   93篇
  2001年   15篇
  2000年   12篇
  1999年   18篇
  1998年   15篇
  1997年   27篇
  1996年   23篇
  1995年   17篇
  1994年   20篇
  1993年   17篇
  1992年   16篇
  1991年   13篇
  1990年   22篇
  1989年   20篇
  1988年   12篇
  1987年   17篇
  1986年   7篇
  1985年   4篇
  1984年   4篇
  1983年   2篇
  1982年   2篇
  1980年   2篇
  1978年   3篇
  1975年   2篇
  1970年   2篇
  1966年   1篇
  1963年   1篇
  1932年   2篇
  1931年   1篇
排序方式: 共有2050条查询结果,搜索用时 15 毫秒
71.

Purpose

To examine the relationship between body mass index (BMI) and the risk of stage ≥3 chronic kidney disease (CKD) in a general Japanese population.

Methods

A total of 105 611 participants aged 40–79 years who completed health checkups in Ibaraki Prefecture, Japan, and were free of CKD in 1993 were followed-up through 2006. Stage ≥3 CKD was defined by an estimated glomerular filtration rate <60 mL/min/1.73 m2 reported during at least 2 successive annual surveys or as treatment for kidney disease. Hazard ratios (HRs) for the development of stage ≥3 CKD relative to the BMI categories were calculated using the Cox proportional hazards regression model, which was adjusted for possible confounders and mediators.

Results

During a mean follow-up of 5 years, 19 384 participants (18.4%) developed stage ≥3 CKD. Compared to a BMI of 21.0–22.9 kg/m2, elevated multivariable-adjusted HRs were observed among men with a BMI ≥23.0 kg/m2 and women with a BMI ≥27.0 kg/m2. Significant dose-response relationships between BMI and the incidence of stage ≥3 CKD were observed in both sexes (P for trend <0.001).

Conclusions

Obesity was associated with the risk of developing stage ≥3 CKD among men and women.Key words: chronic kidney disease, body mass index, obesity, dose-response relationship, epidemiology  相似文献   
72.
Calcifying lesions in the jaws are usually solitary and can be diagnosed by intraoral, panoramic, and conventional extraoral radiographs. It is extremely rare for these calcifying lesions to be multiple, unless they are associated with certain systematic diseases. Herein, we report a rare case of multiple odontomas in a 4-year-old girl. The lesions were scattered throughout both jaws on the panoramic image. The reconstructed CT image showed lesions in the left maxilla that occupied the sinus and affected the floor of the left orbit. The lesions in the mandible were widespread and extended to the tooth-bearing area. Enucleations of the maxillary parts were performed, and the pathological diagnosis was a mixture of complex and compound odontomas. The 3-year postoperative follow-up by panoramic imaging was uneventful. Preoperative CT was useful for the differential diagnosis by depicting the internal calcifying lesions and revealing the extent and complex relationships among the lesions.  相似文献   
73.
Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobin E-mediated food hypersensitivity disorder. However, little is known about the clinical features of FPIES in patients with Down syndrome (DS). Medical records of children with DS diagnosed at our hospital between 2000 and 2019 were retrospectively reviewed. Among the 43 children with DS, five (11.6%) were diagnosed with FPIES; all cases were severe. In the FPIES group, the median age at onset and tolerance was 84 days and 37.5 months, respectively. Causative foods were cow’s milk formula and wheat. The surgical history of colostomy was significantly higher in the FPIES group than in the non-FPIES group. A colostomy was performed in two children in the FPIES group, both of whom had the most severe symptoms of FPIES, including severe dehydration and metabolic acidosis. The surgical history of colostomy and postoperative nutrition of formula milk feeding may have led to the onset of FPIES. Therefore, an amino acid-based formula should be considered for children who undergo gastrointestinal surgeries, especially colostomy in neonates or early infants. When an acute gastrointestinal disease is suspected in children with DS, FPIES should be considered. This may prevent unnecessary tests and invasive treatments.  相似文献   
74.
75.
76.

Background

This study aimed to determine the radiologic predictors and clarify the clinical features related to survival in patients with combined pulmonary fibrosis and emphysema (CPFE) and lung cancer.

Methods

We retrospectively reviewed the medical chart data and high-resolution computed tomography (HRCT) findings for 81 consecutive patients with CPFE and 92 primary lung cancers (70 men, 11 women; mean age, 70.9 years). We selected 8 axial HRCT images per patient, and visually determined the normal lung, modified Goddard, and fibrosis scores. Multivariate analysis was performed using the Cox proportional hazards regression model.

Results

The major clinical features were a high smoking index of 54.8 pack-years and idiopathic pulmonary fibrosis (n = 44). The major lung cancer profile was a peripherally located squamous cell carcinoma (n = 40) or adenocarcinoma (n = 31) adjacent to emphysema in the upper/middle lobe (n = 27) or fibrosis in the lower lobe (n = 26). The median total normal lung, modified Goddard, and fibrosis scores were 10, 8, and 8, respectively. TNM Classification of malignant tumors (TNM) stage I, II, III, and IV was noted in 37, 7, 26, and 22 patients, respectively. Acute exacerbation occurred in 20 patients. Multivariate analysis showed that a higher normal lung score and TNM stage were independent radiologic and clinical predictors of poor survival at the time of diagnosis of lung cancer.

Conclusions

A markedly reduced area of normal lung on HRCT was a relevant radiologic predictor of survival.  相似文献   
77.
78.
Purpose Aurora-A, also known as STK15/BTAK, is a member of the protein serine/threonine kinase family, and experimental studies have revealed that Aurora-A plays critical roles in cell mitosis and in carcinogenesis. However, no clinical studies on Aurora-A expression in non-small-cell lung cancer (NSCLC) have been reported. Thus, the present study was conducted to assess the clinical significance of Aurora-A status. Experimental Design A total of 189 consecutive patients with resected pathologic (p-)stage I-IIIA, NSCLC were retrospectively reviewed, and immunohistochemical staining was used to detect Aurora-A expression. Results Aurora-A expression was negative in 31 patients (16.4%); among Aurora-A positive patients, 124 patients showed pure diffuse cytoplasmic Aurora-A expression and the other 34 patients showed perimembrane Aurora-A expression. Perimembrane Aurora-A tumors showed the highest proliferative index (PI) (mean PIs for negative, diffuse cytoplasmic, and perimembrane tumors: 49.2, 41.7, and 63.5, respectively; P < .001). Five-year survival rates of Aurora-A negative, diffuse cytoplasmic, and perimembrane patients were 67.8%, 66.7%, and 47.6%, respectively, showing the poorest postoperative survival in perimembrane patients (P = .033). Subset analyses revealed that perimembrane Aurora-A expression was a significant factor to predict a poor prognosis in squamous cell carcinoma patients, not in adenocarcinoma patients. A multivariate analysis confirmed that perimembrane Aurora-A expression was an independent and significant factor to predict a poor prognosis. Conclusions Perimembrane Aurora-A status was a significant factor to predict a poor prognosis in correlation with enhanced proliferative activity in NSCLC.  相似文献   
79.
The bone scan index (BSI) is calculated from a whole-body bone scan image; it shows the tumor burden in bone as a percentage of total skeletal mass. It has been used to determine the prognosis and to assess treatment effects; however, little has been reported on whether the BSI calculated using a two-dimensional image can accurately evaluate the three-dimensional spread in tumor volume. We investigated the relationship between tumor volume and BSI using Monte Carlo simulation (MCS). We simulated a gamma camera and constructed a voxel phantom based on an anthropomorphic phantom computed tomography (CT) image and gamma rays emitted from each part according to technetium-99m-labeled methylene diphosphonate (99mTc-MDP) uptake (bone 1, soft tissue 0.2, tumor 2–32). We constructed bone scan images from the obtained counts and analyzed them using the BSI calculation software. The BSI increased with increased tumor uptake (two- to 32-fold). However, there was not always a significant difference between change in BSI and tumor uptake of eight times or greater than that of bone. When BSI was calculated with a tumor having an uptake of four-to-eight times higher than that of bone, the BSI was consistent with tumor volume, but decreased to about half the tumor volume when tumors were in the thoracic spine (Th-spine) segment. The BSI can be a good indicator of tumor volume in most segments, even though it is affected by the tumor’s 99mTc-MDP uptake. Nevertheless, values calculated from the Th-spine should be interpreted carefully.  相似文献   
80.
Patterns of poisoning are known to be different in different countries, because of the local environmental, cultural, and religious situations. Therefore, in Japan, it is important to know the pattern of poisoning in our own country and to prepare for every poisoning case by establishing an efficient systematic toxicological analysis system in forensic practice. We conducted a retrospective study of the kinds of compounds causing poisonings and the frequency of their use based on two series of reports dealing with poisoning cases in Japan prepared by the National Research Institute of Police Science and the Japanese Society of Legal Medicine for 2003 to 2006. From these reports, 459 and 177 compounds, respectively, were extracted as poisonous compounds over the study period. After data analysis, we selected 314 drugs and poisons as important target compounds for systematic drug analysis in Japan; they included 36 volatile compounds, 14 abused drugs, 170 medical drugs, 60 pesticides, 13 natural toxins, and 21 others. This is the first study to show the toxic drugs and poisons to be analyzed in Japan based on frequency of use, and as such the list will be useful in establishing the most efficient screening system in forensic practice.  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