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   4510篇
  免费   259篇
  国内免费   32篇
耳鼻咽喉   44篇
儿科学   191篇
妇产科学   63篇
基础医学   502篇
口腔科学   52篇
临床医学   336篇
内科学   862篇
皮肤病学   273篇
神经病学   271篇
特种医学   188篇
外科学   512篇
综合类   100篇
预防医学   325篇
眼科学   147篇
药学   496篇
中国医学   43篇
肿瘤学   396篇
  2023年   24篇
  2022年   45篇
  2021年   96篇
  2020年   54篇
  2019年   67篇
  2018年   95篇
  2017年   70篇
  2016年   121篇
  2015年   117篇
  2014年   130篇
  2013年   207篇
  2012年   243篇
  2011年   249篇
  2010年   175篇
  2009年   174篇
  2008年   187篇
  2007年   181篇
  2006年   174篇
  2005年   160篇
  2004年   145篇
  2003年   117篇
  2002年   100篇
  2001年   60篇
  2000年   88篇
  1999年   91篇
  1998年   98篇
  1997年   74篇
  1996年   83篇
  1995年   72篇
  1994年   76篇
  1993年   56篇
  1992年   102篇
  1991年   56篇
  1990年   75篇
  1989年   98篇
  1988年   99篇
  1987年   72篇
  1986年   60篇
  1985年   44篇
  1984年   63篇
  1983年   44篇
  1982年   35篇
  1981年   38篇
  1980年   21篇
  1979年   36篇
  1978年   26篇
  1976年   27篇
  1973年   24篇
  1972年   21篇
  1964年   21篇
排序方式: 共有4801条查询结果,搜索用时 31 毫秒
1.
2.
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.  相似文献   
3.
4.
5.
Abstract:  In Sweet's syndrome, the essential features are the characteristic morphology of the lesions, their histologic appearance, the dramatic response to corticosteroids and the absence of scarring. We report an 8-month-old infant in whom Sweet's syndrome was diagnosed and who developed acquired cutis laxa in the skin lesions.  相似文献   
6.
The abdominal compartment syndrome is a life threatening condition resulting from pathologic elevation of the intraabdominal pressure. Prompt diagnosis is required to avoid significant sequelae. Diagnosis of this syndrome is based on clinical findings and intra abdominal pressure monitoring. Treatment consists of decompressive laparotomy, which corrects the pathology. Various surgical techniques are described to manage the open abdomen. Despite considerable attention accorded to this disorder, it is still associated with high morbidity and mortality. This review article deals with the identification of risk factors, pathophysiology, diagnostic criteria and treatment of critically ill patients with the abdominal compartment syndrome.  相似文献   
7.
Carcinoma gallbladder is the commonest malignancy in the Northern part of India. The heavy metals are known carcinogens while trace metals have protective effect. Aim The aim of the study is to estimate the heavy and trace metal (Lead, Zinc, Copper, Cadmium, Chromium, Manganese and Selenium) concentration in serum, bile, tissue and gallstone in patients with gallbladder diseases. Method This is a pilot study conducted in 45 cases (Group – I: 15 cases of carcinoma gallbladder, Group II: 15 patients of cholecystitis with cholelithiasis and Group – III: 15 patients of healthy control), to detect the relationship between the heavy and trace metal concentration and gall bladder carcinoma. Analysis of metal was done using Perkins‐Elmer model 2380 atomic absorption spectrophotometer. Results The serum concentration of copper and nickel was significantly high in carcinoma gallbladder patients as compared to patients with cholecystitis while zinc and selenium is low in carcinoma gallbladder patients. Bile concentration of zinc, selenium and manganese was significantly low in carcinoma gallbladder patients (p < 0.05) as compared to patients of cholelithiasis while cadmium and nickel was high. Tissue concentration of manganese was significantly low in carcinoma gallbladder patients as compared to patients of cholelithiasis while chromium was high. Gallstone concentration of copper, manganese and lead was significantly low in carcinoma gallbladder patients as compared to patients of cholelithiasis. Conclusion The heavy metals are in higher concentration in carcinoma gallbladder while trace metals are in lower concentration indicating possible role of heavy metal in gallbladder carcinogenesis.  相似文献   
8.
9.
Growing rats were exposed to 5 mg/L Pb,ad libitum in drinking water, and administered low or high doses of Mn and Cd intraperitoneal (i.p.) for 30 days. Some groups of animals were also administered combinations of Pb + Mn and Pb + Cd in an identical manner. Analysis of Pb, Mn, and Cd in tissue samples showed the expected dose-dependent accumulation when the metal was administered singly. However, combined treatment produced different types of metal shift in different tissues. Enhanced accumulation of all three metals in the brain, Mn in liver, Pb in kidney and Cd in testis and kidney after combined exposure may make target organs vulnerable to the toxic effects of metals, even when encountered at low concentrations. Further, the decreased levels of blood Pb after combined treatment with Cd or Mn suggests that the significance of blood Pb level as a diagnostic aid for Pb toxicity in coexposed conditions may not be of much value. Changes in the metallic distribution within the tissues after coexposure may be the result of a competition between the administered metals for common binding sites.  相似文献   
10.
Background. Extensive questioning of patients with a wide variety of skin disorders led to the impression that nocturnal overheating was probably an important factor in the initiation and the perpetuation of many skin disorders. Methods. In order to test the hypothesis, 12 “clean-skinned” subjects (6M/6F) aged 18 to 45 years were monitored electronically every 30 seconds during an 8 hour sleep period (2300 to 0700 hours), sleeping under a standard 10 tog duvet. Results. All the subjects were too hot by 3 to 4°C. All showed changes in their EEG patterns with reduced REM sleep, increased awakenings, and all showed changes in their sleep stage patterns. In addition, they all showed evidence of increased sweating in the “heat-sink” area. Conclusions. The mechanisms where by such changes could be implicated in the precipitation and perpetuation of skin disease are discussed. “Lifestyle” modification as a very effective, noninvasive, therapeutic regime is recommended. Further research along these lines would probably be very valuable and instructive.  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