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   1864篇
  免费   176篇
  国内免费   20篇
耳鼻咽喉   6篇
儿科学   91篇
妇产科学   14篇
基础医学   217篇
口腔科学   72篇
临床医学   233篇
内科学   440篇
皮肤病学   53篇
神经病学   120篇
特种医学   288篇
外科学   158篇
综合类   56篇
一般理论   3篇
预防医学   85篇
眼科学   35篇
药学   60篇
  1篇
肿瘤学   128篇
  2021年   12篇
  2020年   14篇
  2019年   19篇
  2018年   31篇
  2017年   15篇
  2016年   18篇
  2015年   38篇
  2014年   37篇
  2013年   70篇
  2012年   65篇
  2011年   51篇
  2010年   69篇
  2009年   73篇
  2008年   46篇
  2007年   55篇
  2006年   49篇
  2005年   52篇
  2004年   46篇
  2003年   53篇
  2002年   44篇
  2001年   33篇
  2000年   24篇
  1999年   37篇
  1998年   89篇
  1997年   80篇
  1996年   64篇
  1995年   62篇
  1994年   43篇
  1993年   52篇
  1992年   26篇
  1991年   49篇
  1990年   36篇
  1989年   66篇
  1988年   57篇
  1987年   48篇
  1986年   44篇
  1985年   49篇
  1984年   29篇
  1983年   28篇
  1982年   30篇
  1981年   24篇
  1980年   27篇
  1979年   29篇
  1978年   29篇
  1977年   20篇
  1976年   23篇
  1975年   20篇
  1974年   10篇
  1973年   11篇
  1972年   11篇
排序方式: 共有2060条查询结果,搜索用时 336 毫秒
51.
Hirsh HL 《Urban health》1983,12(10):35-43, 49
For more than ten years the medical profession, the legal profession, and perhaps thousands of patients and their relatives have wrestled with the issues of therapy withdrawal, removal of life-sustaining machinery when recovery is hopeless. This major article presents a wide range of insights useful for the individual physician, the hospital governing board, the nurse as well as for policy and lawmakers who confront this issue.  相似文献   
52.
53.
BACKGROUND: Trastuzumab provides significant clinical benefits in HER2-positive metastatic breast cancer patients when administered in combination with chemotherapy. Chemotherapy has also been shown to be beneficial in some patients with advanced non-small-cell lung cancer (NSCLC). The present randomized phase II trial examined the effect of adding trastuzumab to a standard chemotherapeutic combination (gemcitabine-cisplatin) in patients with HER2-positive NSCLC. PATIENTS AND METHODS: Patients with untreated stage IIIB/IV HER2-positive NSCLC received up to six 21-day cycles of gemcitabine 1250 mg/m(2) (days 1 and 8) and cisplatin 75 mg/m(2) (day 1). Patients in the trastuzumab arm received trastuzumab 4 mg/kg intravenously (i.v.) followed by 2 mg/kg/week i.v. until progression. RESULTS: Of 619 patients screened, 103 were eligible. Fifty-one patients were treated with trastuzumab plus gemcitabine-cisplatin and 50 with gemcitabine-cisplatin alone. Efficacy was similar in the trastuzumab and control arms: response rate 36% versus 41%; median time to progression 6.3 versus 7.2 months; and median progression-free survival (PFS) 6.1 versus 7 months. Response rate (83%) and median PFS (8.5 months) appeared relatively good in the six trastuzumab-treated patients with HER2 3+ or fluorescence in situ hybridization (FISH)-positive NSCLC. Addition of trastuzumab to gemcitabine-cisplatin was well tolerated, side-effects were as expected, and trastuzumab did not exacerbate the known toxicity of gemcitabine and cisplatin. Symptomatic cardiotoxicity was observed in one trastuzumab-treated patient. Serum trastuzumab concentrations in the presence of gemcitabine-cisplatin were comparable to those of trastuzumab alone. CONCLUSIONS: Trastuzumab plus gemcitabine-cisplatin is well tolerated. Clinical benefit was not observed. Although HER2 3+/FISH-positive patients may benefit from trastuzumab, the subgroup is too small to provide definitive information. No significant effect of gemcitabine-cisplatin on trastuzumab pharmacokinetics was observed.  相似文献   
54.
55.
Objectives: To describe the physical growth patterns of infants born to narcotic dependent mothers (INDM) over a 12 months period and, if possible, to relate the growth to drug taking patterns during pregnancy.
Methodology: The growth of a cohort of 43 INDM was measured during the first 12 months of life. Weight and length measurements were compared with percentile charts and converted to Z scores. Questionnaire data about drug taking practices, demographic variables and the neonatal period (including withdrawal scores) were obtained.
Results: Twenty-four (55.8%) of INDM had evidence of neonatal drug withdrawal requiring treatment with phenobarbitone. At birth, Z scores for weight and length indicated relative intrauterine growth retardation. By 12 months, there had been some catch up growth, but Z scores for weight and length were still below zero. Persistent weight retardation at 12 months was correlated with methadone dosage during pregnancy, but not the need for phenobarbitone therapy.
Conclusions: The growth patterns of INDM in the first 12 months of life indicated that at birth there was evidence of intrauterine growth retardation, but by 12 months the growth was little different from the rest of the community. There appears to be some influence of narcotic agents taken while pregnant on subsequent growth of INDM.  相似文献   
56.
57.
Aflatoxin B1 (AFB1), a mutagen and hepatocarcinogen in rats and humans, is a contaminant of the human food supply, particularly in parts of Africa and Asia. AFB1-induced changes in gene expression may play a part in the development of the toxic, immunosuppressive and carcinogenic properties of this fungal metabolite. An understanding of the-role of AFB1 in modulating gene regulation should provide insight regarding mechanisms of AFB1-induced carcinogenesis. We used three PCR- based subtractive techniques to identify AFB1-responsive genes in cultured primary rat hepatocyte RNA: differential display PCR (DD-PCR), representational difference analysis (RDA) and suppression subtractive hybridization (SSH). Each of the three techniques identified AFB1- responsive genes, although no individual cDNA was isolated by more than one technique. Nine cDNAs isolated using DD-PCR, RDA or SSH were found to represent eight genes that are differentially expressed as a result of AFB1 exposure. Genes whose mRNA levels were increased in cultured primary rat hepatocytes after AFB1 treatment were corticosteroid binding globulin (CBG), cytochrome P450 4F1 (CYP4F1), alpha-2 microglobulin, C4b-binding protein (C4BP), serum amyloid A-2 and glutathione S-transferase Yb2 (GST). Transferrin and a small CYP3A-like cDNA had reduced mRNA levels after AFB1 exposure. Full-length CYP3A mRNA levels were increased. When liver RNA from AFB1-treated male F344 rats was evaluated for transferrin, CBG, GST, CYP3A and CYP4F1 expression, a decrease in transferrin mRNA and an increase in CBG, GST, CYP3A and CYP4F1 mRNA levels was also seen. Analysis of the potential function of these genes in maintaining cellular homeostasis suggests that their differential expression could contribute to the toxicity associated with AFB1 exposure.   相似文献   
58.
Nonalcoholic fatty liver disease (NAFLD) is the leading cause of liver disease worldwide, with rising rates in parallel to those of obesity, type 2 diabetes, and metabolic syndrome. NAFLD encompasses a wide spectrum of pathology from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis, which are linked to poor outcomes. Studies confirm a significant amount of undiagnosed NAFLD and related fibrosis within the community, increasing the overall burden of the disease. NAFLD appears to be more prevalent in certain populations, such as those with type 2 diabetes and metabolic syndrome. Early detection and lifestyle modifications, including weight loss and regular exercise, have been shown to improve outcomes. Adverse cardiovascular events are a key contributor to NAFLD-associated morbidity and mortality, and efforts to minimize their occurrence are essential. A targeted and algorithmic approach using noninvasive diagnostic techniques is promptly required to identify and risk-stratify patients with NAFLD. Patients at low risk of progression to NASH and advanced fibrosis can be managed in the primary care setting, while those at high risk of disease progression should be referred to hepatology specialists for surveillance and treatment. This review summarizes the key data of NAFLD's impact within primary care populations and proposes a potential algorithmic approach to identifying and managing such patients.  相似文献   
59.
60.
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