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   15255篇
  免费   1197篇
  国内免费   54篇
耳鼻咽喉   208篇
儿科学   322篇
妇产科学   215篇
基础医学   1898篇
口腔科学   430篇
临床医学   1530篇
内科学   3569篇
皮肤病学   187篇
神经病学   1174篇
特种医学   635篇
外科学   2291篇
综合类   315篇
一般理论   16篇
预防医学   1152篇
眼科学   502篇
药学   1044篇
中国医学   38篇
肿瘤学   980篇
  2022年   81篇
  2021年   191篇
  2020年   96篇
  2019年   191篇
  2018年   214篇
  2017年   167篇
  2016年   204篇
  2015年   250篇
  2014年   397篇
  2013年   663篇
  2012年   820篇
  2011年   895篇
  2010年   490篇
  2009年   471篇
  2008年   875篇
  2007年   992篇
  2006年   1013篇
  2005年   983篇
  2004年   1043篇
  2003年   957篇
  2002年   967篇
  2001年   132篇
  2000年   89篇
  1999年   166篇
  1998年   229篇
  1997年   205篇
  1996年   181篇
  1995年   192篇
  1994年   144篇
  1993年   150篇
  1992年   87篇
  1991年   91篇
  1990年   95篇
  1989年   94篇
  1988年   99篇
  1987年   78篇
  1986年   86篇
  1985年   110篇
  1984年   167篇
  1983年   147篇
  1982年   217篇
  1981年   217篇
  1980年   164篇
  1979年   90篇
  1978年   113篇
  1977年   143篇
  1976年   136篇
  1975年   121篇
  1974年   94篇
  1973年   90篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Critically ill patients in the intensive care unit (ICU) have a high risk of developing malnutrition, and this is associated with poorer clinical outcomes. In clinical practice, nutrition, including enteral nutrition (EN), is often not prioritized. Resulting from this, risks and safety issues for patients and healthcare professionals can emerge. The aim of this literature review, inspired by the Rapid Review Guidebook by Dobbins, 2017, was to identify risks and safety issues for patient safety in the management of EN in critically ill patients in the ICU. Three databases were used to identify studies between 2009 and 2020. We assessed 3495 studies for eligibility and included 62 in our narrative synthesis. Several risks and problems were identified: No use of clinical assessment or screening nutrition assessment, inadequate tube management, missing energy target, missing a nutritionist, bad hygiene and handling, wrong time management and speed, nutritional interruptions, wrong body position, gastrointestinal complication and infections, missing or not using guidelines, understaffing, and lack of education. Raising awareness of these risks is a central aspect in patient safety in ICU. Clinical experts can use a checklist with 12 identified top risks and the recommendations drawn up to carry out their own risk analysis in clinical practice.  相似文献   
82.
Advances in Health Sciences Education - It was recently shown that novice medical students could be trained to demonstrate the speed-to-diagnosis and diagnostic accuracy typical of System-1-type...  相似文献   
83.

There is agreement among health economists that on the whole medical innovation causes health care expenditures (HCE) to rise. This paper analyzes for which diagnoses HCE per patient have grown significantly faster than average HCE. We distinguish decedents (patients in their last 4 years of life) from survivors and use a unique dataset comprising detailed HCE of all members of a regional health insurance fund in Upper Austria for the period 2005–2018. Our results indicate that among decedents in particular, the expenditures for treatment of neoplasms have exceeded the general trend in HCE. This confirms that medical innovation for this group of diseases has been particularly strong over the last 15 years. For survivors, we find a noticeable growth in cases and cost per case for pregnancies and childbirth, and also for treatment of mental and behavioral disorders. We discuss whether these findings contradict the widespread interpretation of cost-increasing innovations as “medical progress” and offer some policy recommendations.

  相似文献   
84.
Bioethics for clinicians: 23. Disclosure of medical error   总被引:8,自引:2,他引:6       下载免费PDF全文
ADVERSE EVENTS AND MEDICAL ERRORS ARE NOT UNCOMMON. In this article we review the literature on such events and discuss the ethical, legal and practical aspects of whether and how they should be disclosed to patients. Ethics, professional policy and the law, as well as the relevant empirical literature, suggest that timely and candid disclosure should be standard practice. Candour about error may lessen, rather than increase, the medicolegal liability of the health care professionals and may help to alleviate the patient's concerns. Guidelines for disclosure to patients, and their families if necessary, are proposed.  相似文献   
85.
To date, little is known about the duration and effectiveness of immunity as well as possible adverse late effects after an infection with SARS-CoV-2. Thus it is unclear, when and if liver transplantation can be safely offered to patients who suffered from COVID-19. Here, we report on a successful liver transplantation shortly after convalescence from COVID-19 with subsequent partial seroreversion as well as recurrence and prolonged shedding of viral RNA.  相似文献   
86.
Brain damaged (BD), psychiatric (P), and normal (N) groups were compared on adaptability to prism-displaced vision. Although no difference among the groups was found on compensatory pre-post shifts of felt limb position (“proprioceptive shift”), the BD group manifested significantly less shift in target-pointing accuracy (“negative aftereffect”) than either of the other two groups. The latter result suggests that brain damaged individuals are, in general, unable to acquire the “cognitive” component of adaptation which results from consistently accurate target-pointing performance during the prism-exposure period. Frontal and non-frontal BD Ss adapted equally on proprioceptive shift, while the non-frontals evidenced significantly less negative aftereffect. It was suggested that this result and the fact that frontals adapted equally (on all measures) with the N group had implications for Teuber's “corollary discharge” hypothesis.  相似文献   
87.
The uptake of persistent polychlorinated hydrocarbons (PCHs) by four avian species was investigated at upper trophic levels of two aquatic food chains of the lower Fox River and Green Bay, Wisconsin. Accumulation of total and specific planar polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxin (PCDDs), and H411E rat hepatoma cell bioassay-derived 2,37,8-tetrachlorodibenzop-dioxin equivalents (TCDD-EQ) was evaluated in Forster's tern (Sterna forsteri) and common tern (Sterna hirundo) chicks, and in tree swallow (Tachycineta bicolor) and red-winged blackbird (Agelaius phoeniceus) nestlings from colonies nesting in several locations within the watershed. Concentrations of the PCHs were greatest in eggs and chicks of the two tern species, less in the tree swallows and least in the red-winged blackbirds. Young of all four species accumulated total PCBs, PCB congeners 77, 105, 126, and 169, and TCDD-EQ. The young birds also accumulated small concentrations of several 2,3,7,8-sbustituted PCDF and PCDD congeners. Uptake rates for certain of the PCHs for the Forster's tern chicks were: 15 g/day for total PCBs, 70, 200, 6.5, and 0.14 ng/day for PCB congeners 77, 105, 126, and 169, respectively, and 270 g/day for TCDD-EQ. Principal components analysis revealed that the patterns of PCH concentrations in the samples were influenced by species of bird, their age (or length of exposure) and nesting location. Collectively, our findings demonstrate that exposure of avian species to contaminants derived from aquatic food chains can be characterized and quantified for the purposes of ecological risk assessment.  相似文献   
88.
Samples of human allograft skin prepared without freezing ("fresh skin) were found to have electrical and sodium ion transport properties which differed only slightly from those of skin which had been similarly treated but stored frozen (frozen skin). The fresh skin samples were less permeable to sodium ions during passive diffusion and less conductive than frozen skin at low current levels. They were more permselective for sodium versus chloride during constant-current iontophoresis and showed slightly more asymmetry in their current–voltage properties. Overall, the electrical behavior of the two tissues was similar enough to support the use of frozen tissue in iontophoresis studies. However, caution should be exercised when considering the use of frozen skin for applications, such as those based on electroosmosis, where the observed differences could have a major impact on the results.  相似文献   
89.
Objective: The objective of this study was to analyze whether faculty ratings of residents, using the mini-CEX oral exam format, differed in stringency or were influenced by the clinical setting. It also sought to learn whether the examiners were satisfied with the format.Method: A mini-CEX encounter consisted of a single faculty member observing a resident conduct a focused history and physical examination in an inpatient, outpatient, or emergency room setting. After asking the resident for a diagnosis and treatment plan, the faculty member rated the resident and provided educational feedback. The encounters were intended to be short and occur as a routine part of the training, so each resident would be evaluated on many occasions by different faculty.Sample: Sixty-four attending physicians evaluated residents from five internal medicine training programs; data were analyzed for 355 mini-CEX encounters involving 88 residents.Results: There were not large differences among the examiners in their ratings. Moreover, there were not great differences among the ratings in terms of the training program with which the examiner was associated, the setting of the mini-CEX, or the nature of the patient. The examiners were generally satisfied with the format and their level of satisfaction was correlated with the residents' perceptions of the format.Conclusion: The mini-CEX adapts itself to a broad range of clinical situations, and these results show that it should produce roughly comparable scores over examiners and settings. This makes it a worthwhile device for evaluation at the local level.This revised version was published online in September 2005 with corrections to the Cover Date.  相似文献   
90.
Previous studies have illustrated the importance of T cellsbearing ß TCRs in the induction and development ofcollagen induced arthritis (CIA) in mice. However, the scopeof TCR usage in CIA has yet to be clearly defined. Given theinherent diversity of the TCR repertoire, the relative flexibilityof the arthritogenic TCR repertoire specific for type II collagen(CII) is not clear. Therefore, we chose to examine the influenceof a highly skewed TCR repertoire on CIA. Arthritis susceptibleB10.Q (H-2q) mice were mated with C57L (H-2b) animals expressingan ovalbuminspecific Vß8.2 TCR transgene (Tg) andTg+ offspring were further backcrossed to B10.Q. HomozygousH-2a/q, Vß8.2 Tg+ mice displayed a high level of Vß8.2+T cells in peripheral blood. However, expression of some endogenousVß TCR, such as Vß14, was still detected.Upon immunization with bovine CII in adjuvant, Vß8.2Tg+ mice were highly resistant to CIA when compared with Tglittermates. Analysis of sera demonstrated a marked reductionin antibody specific for homologous mouse CII as well as heterologousbovine CII in Tg+ animals. Interestingly, Vß8.2 Tg+mice still mounted good antibody responses following immunizationwith human thyroglobulin, indicating that the skewed TCR repertoireaffected anti-CII but not antithyroglobulin responses. Thus,our findings show that constraints placed on the TCR repertoireInhibit pathogenic responses against CII and suggest that inH-2q mice the arthritogenlc TCR repertoire bears only limitedflexibility.  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