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   1275篇
  免费   106篇
  国内免费   4篇
耳鼻咽喉   33篇
儿科学   29篇
妇产科学   5篇
基础医学   157篇
口腔科学   11篇
临床医学   119篇
内科学   168篇
皮肤病学   26篇
神经病学   116篇
特种医学   23篇
外科学   341篇
综合类   36篇
一般理论   4篇
预防医学   93篇
眼科学   7篇
药学   70篇
肿瘤学   147篇
  2023年   7篇
  2022年   11篇
  2021年   9篇
  2020年   6篇
  2019年   12篇
  2018年   23篇
  2017年   18篇
  2016年   21篇
  2015年   33篇
  2014年   38篇
  2013年   50篇
  2012年   75篇
  2011年   92篇
  2010年   50篇
  2009年   49篇
  2008年   56篇
  2007年   84篇
  2006年   76篇
  2005年   77篇
  2004年   65篇
  2003年   81篇
  2002年   50篇
  2001年   12篇
  2000年   20篇
  1999年   17篇
  1998年   28篇
  1997年   23篇
  1996年   22篇
  1995年   21篇
  1994年   17篇
  1993年   18篇
  1992年   12篇
  1991年   13篇
  1990年   13篇
  1989年   16篇
  1988年   20篇
  1987年   16篇
  1986年   20篇
  1985年   9篇
  1984年   23篇
  1983年   14篇
  1982年   9篇
  1981年   9篇
  1980年   6篇
  1978年   5篇
  1977年   3篇
  1975年   6篇
  1974年   4篇
  1973年   8篇
  1971年   6篇
排序方式: 共有1385条查询结果,搜索用时 85 毫秒
61.
62.
63.
The most common complaints of cancer patients undergoing chemoor radiotherapy are fatigue, nausea, vomiting, malaise, diarrhea and headaches. These adverse effects are thought to be due to damage of normal tissues during the course of therapy. In addition, recent evidence indicates that fatigue is related to reduced mitochondrial function through loss of efficiency in the electron transport chain caused by membrane oxidation, and this occurs during aging, in fatiguing illnesses and in cancer patients during cytotoxic therapy. Lipid Replacement Therapy administered as a nutritional supplement with antioxidants can prevent oxidative membrane damage to normal tissues, restore mitochondrial and other cellular membrane functions and reduce the adverse effects of cancer therapy. Recent clinical trials using patients with chronic fatigue have shown the benefit of Lipid Replacement Therapy plus antioxidants in restoring mitochondrial electron transport function and reducing moderate to severe chronic fatigue by protecting mitochondrial and other cellular membranes from oxidative and other damage. In cancer patients a placebo-controlled, cross-over clinical trial using Lipid Replacement Therapy plus antioxidants demonstrated that the adverse effects of chemotherapy can be reduced in 57–70% of patients. Dietary use of unoxidized membrane lipids plus antioxidants is recommended for patients undergoing cancer therapy to improve quality of life but should not be taken at the same time of day as the therapy. The author has no financial interest in the products discussed in this contribution.  相似文献   
64.
A 38-year-old woman presented with an infiltrative tumor of the right frontal lobe and genu of the corpus callosum that was deemed only partially resectable. A stereotactic biopsy was performed, which revealed a right frontal oligoastrocytoma that had some anaplastic features as well as allelic loss of chromosome arms 1p and 19q. The patient was treated with temozolomide for 24 months. The partial response of the tumor to chemotherapy rendered the lesion amenable to gross total resection, which was performed subsequently. The patient remains alive and well without evidence of recurrence 7 months after resection and 48 months after initial diagnosis. Thus, preoperative chemotherapy decreased tumor mass to a degree that subsequently enabled a gross total resection. This treatment strategy, although common in the treatment of other solid tumors, is rarely utilized in adult neuro-oncology and raises another potential role for chromosome testing in oligodendroglial tumor management.  相似文献   
65.
Primary care and sports medicine physicians are frequently consulted on medical clearance for prospective recreational divers. We discuss four common and controversial medical conditions—asthma, diabetes mellitus, coronary artery disease, and patent foramen ovale—as they relate to fitness to dive. For each condition we review the relevant anatomy and physiology, current recommendations, and the pertinent medical literature. Finally, we offer evidence-based recommendations regarding fitness to dive for potential divers with these conditions.  相似文献   
66.
Bacterial biofilms have recently been shown to be important in neurosurgical device-related infections. Because the concept of biofilms is novel to most practitioners, it is important to understand that both traditional pharmaceutical therapies and host defense mechanisms that are aimed at treating or overcoming free-swimming bacteria are largely ineffective against the sessile bacteria in a biofilm. Bacterial biofilms are complex surface-attached structures that are composed of an extruded extracellular matrix in which the individual bacteria are embedded. Superimposed on this physical architecture is a complex system of intercellular signaling, termed quorum sensing. These complex organizational features endow biofilms with numerous microenvironments and a concomitant number of distinct bacterial phenotypes. Each of the bacterial phenotypes within the biofilm displays a unique gene expression pattern tied to nutrient availability and waste transport. Such diversity provides the biofilm as a whole with an enormous survival advantage when compared to the individual component bacterial cells. Thus, it is appropriate to view the biofilm as a multicellular organism, akin to metazoan eukaryotic life. Bacterial biofilms are much hardier than free floating or planktonic bacteria and are primarily responsible for device-related infections. Now that basic research has demonstrated that the vast majority of bacteria exist in biofilms, the paradigm of biofilm-associated chronic infections is spreading to the clinical world. Understanding how these biofilm infections affect patients with neurosurgical devices is a prerequisite to developing strategies for their treatment and prevention.  相似文献   
67.
This article describes the evaluation of the HIV/AIDS communication aspect of the multi media Soul City health promotion intervention in South Africa. The intervention consists of a television and radio drama and print material. The evaluation was multifaceted with a before and after national survey and a national qualitative study. In the before and after survey change was measured and then multiple regression analysis was performed to assess the variables associated with the change. The qualitative study consisted of focus group discussions, which were analysed thematically. The studies show that there are numerous instances of community change and how the change is mediated at the community level. The studies also describe the change at a number of levels of the described behaviour change model for individuals.  相似文献   
68.
The introduction of computed tomography (CT) in 1972 revolutionized the radiographic evaluation of patients who have experienced trauma. However, panoramic tomography (PT) continued to be superior in sensitivity to CT in the identification of mandible fractures and has been considered the gold standard for the past 3 decades. In 1989, a faster, higher-resolution spiral or helical CT (HCT) became widely available, and its efficacy in multiplanar evaluation and diagnosis of fractures of the upper two thirds of the face has been well established. The sensitivity of this new-generation HCT in comparison to PT in the detection of mandible fractures has not been determined. The purpose of this study was to compare the sensitivity, physician interpretation error, and interphysician agreement of HCT and PT in the identification of mandible fractures. The number and anatomical location of mandible fractures identified by HCT and PT was not significantly different. However, the number and location of 96% of fractures identified by HCT was agreed on by neuroradiologists compared with only 91% of fractures identified by PT. Furthermore, the interphysician agreement when no fracture was identified was 96% by HCT versus only 81% by PT. In conclusion, HCT has enhanced imaging quality, equivalent sensitivity in identification of fractures, decreased interpretation error, and greater interphysician agreement in the identification of mandible fractures. HCT has surpassed PT as the current gold standard for the radiographic evaluation and diagnosis of mandible fractures.  相似文献   
69.
The role of opioid receptors located in the central nervous system (CNS) and peripheral nervous system in inflammatory pain is well established. In contrast, although it is has been shown that mu agonists can reduce other manifestations of inflammation, such as edema, the mechanism of action remains unclear. In this study, we have activated mu receptors located centrally, those located peripherally, and those located both centrally and peripherally and compared the effects on pain and edema using the rat carrageenan model of acute inflammation. Activation of mu receptors located only in the periphery, by administration of the peripheralized mu agonist [8-(3,3-diphenyl-propyl)-4-oxo-1-phenyl-1,3,8-triaza-spiro[4.5]dec-3-yl]-acetic acid (DiPOA) or local administration of morphine, resulted in antihyperalgesia (30 mg/kg DiPOA, 83% inhibition; 100 microg/rat morphine, 75% inhibition) without affecting edema. In contrast, activation of both central and peripheral mu receptors using systemically administered morphine resulted in antihyperalgesia (1 mg/kg, 80% inhibition) and inhibition of edema (10 mg/kg, 54% inhibition). Finally, activation of only receptors located in the CNS, by central administration of DiPOA or systemic administration of morphine after block of only the peripheral mu receptors using q-naltrexone, resulted in a significant reduction in edema. Our findings confirm the role of peripheral mu receptors in the pathology of pain associated with acute inflammation and argue against the involvement of these receptors in edema formation. Furthermore, our data demonstrate that activation of mu receptors in the brain inhibits carrageenan-induced edema and suggest that the antiedematous effect of morphine is due to action at central receptors alone.  相似文献   
70.
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