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   39289篇
  免费   2718篇
  国内免费   126篇
耳鼻咽喉   369篇
儿科学   974篇
妇产科学   937篇
基础医学   5101篇
口腔科学   645篇
临床医学   3792篇
内科学   7590篇
皮肤病学   588篇
神经病学   4099篇
特种医学   1276篇
外科学   6492篇
综合类   464篇
现状与发展   1篇
一般理论   35篇
预防医学   3251篇
眼科学   999篇
药学   2644篇
中国医学   114篇
肿瘤学   2762篇
  2023年   209篇
  2022年   310篇
  2021年   880篇
  2020年   543篇
  2019年   796篇
  2018年   1011篇
  2017年   719篇
  2016年   721篇
  2015年   854篇
  2014年   1327篇
  2013年   1718篇
  2012年   2796篇
  2011年   2920篇
  2010年   1643篇
  2009年   1482篇
  2008年   2659篇
  2007年   2844篇
  2006年   2671篇
  2005年   2617篇
  2004年   2500篇
  2003年   2365篇
  2002年   2165篇
  2001年   377篇
  2000年   331篇
  1999年   381篇
  1998年   440篇
  1997年   388篇
  1996年   379篇
  1995年   310篇
  1994年   297篇
  1993年   261篇
  1992年   224篇
  1991年   190篇
  1990年   155篇
  1989年   143篇
  1988年   164篇
  1987年   150篇
  1986年   135篇
  1985年   139篇
  1984年   146篇
  1983年   155篇
  1982年   193篇
  1981年   171篇
  1980年   146篇
  1979年   85篇
  1978年   114篇
  1977年   115篇
  1976年   87篇
  1975年   89篇
  1974年   75篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
The worldwide shortage of organs for transplantation makes it important to understand why some oppose donation. Attitudes vary with religion and ethnicity. Accordingly, we undertook a qualitative study of the attitudes of 141 U.K. Muslim Indo-Asians to organ donation. Participants were observed, focus group discussions held and in-depth individual interviews conducted. We identified a high level of alienation from the health care system in general. With respect to organ donation in particular, its importance was generally discounted, often in deference to authority figures within the community who appeared negatively disposed. The culture-specific issues arguing against donation included a sense of the sacredness of the body, a fatalistic approach to illness, a belief that organs took on an independent role as 'witnesses' to an individual's life on Judgement Day and an anxiety that the donor would have no control of the probity of the recipient of an organ. We believe these data suggest a need to improve in a culturally sensitive fashion the provision of health information provided to this community.  相似文献   
62.
PURPOSE: Whereas the relationship between epilepsy and anxiety has received much attention, less is known about the relationship between death anxiety and this disorder. The objective of this study was to assess death anxiety among epileptic patients who attended the outpatient neurology clinic at the Salmaniya Medical Complex, Kingdom of Bahrain. METHODS: Ninety-two patients (48 males and 44 females) completed a death anxiety scale. The scale items were adopted from already published surveys and adjusted to suit epilepsy patients. RESULTS: Results showed that the mean death anxiety score was moderate (2.75+/-1.35), with 26.09% of patients reporting high levels of death anxiety. Period of illness and educational level were significant predictors of death anxiety. Female patients, generalized type of epilepsy, the short duration of the illness and low level of education were associated with higher death anxiety scores. CONCLUSION: This study highlights the need for developing treatment strategies, counseling therapies and social support for people with epilepsy to decrease their death anxiety and improve their quality of life.  相似文献   
63.
In this paper, we reviewed all existing studies using electroencephalography (EEG) in infants and children with known prenatal exposure to alcohol (PEA). The guiding purposes of the review were to determine if (1) EEG is a useful neuroimaging technique for investigating the brain correlates of PEA in infants and children, (2) there are indeed consistent EEG correlates of PEA in literature, and (3) these EEG correlates can be framed within a coherent picture of emerging implications for the study of PEA and its effects. The review confirms that EEG techniques have proven useful in indicating evidence of differential effects of patterns of PEA and timing in early fetal development and impairment of brain maturation in older children. In general, these techniques could be important in functional assessment of the brain of children affected by PEA, especially if used in conjunction with other neuroimaging techniques. The reviewed studies also suggest that although the impact on sensory and cognitive functions may involve extensive neural networks, there are EEG correlates of PEA which may in the future lead to the identification of neurophysiologic markers. A consistent aspect that emerges from the EEG data is that converging evidence from the study of different systems and processes suggests that PEA may almost invariably have consequences for later neurocognitive development.  相似文献   
64.
65.
OBJECTIVE: To describe the dieting histories of bariatric surgery candidates. RESEARCH METHODS AND PROCEDURES: One hundred seventy-seven individuals with extreme obesity who sought bariatric surgery completed the Weight and Lifestyle Inventory, a self-report instrument that assesses several variables, including weight and dieting history. Patients' dieting histories were further explored with an aided recall during a preoperative behavioral/psychological evaluation performed by a mental health professional. RESULTS: Participants who completed the Weight and Lifestyle Inventory reported an average of 4.7 +/- 2.9 successful dieting attempts, defined as those that resulted in a loss of 10 lbs (4.5 kg) or more. These individuals reported a mean total lifetime weight loss of 61.1 +/- 41.3 kg. Despite these efforts, their weight increased from 89.4 +/- 27.4 kg at the time of their first diet (age 21.2 +/- 10.1 years) to 144.5 +/- 30.8 kg at the time they underwent their behavioral/psychological evaluation (age 43.0 +/- 11.0 years). Results of the aided recall revealed that participants had made numerous other efforts to lose weight that were unsuccessful. Self-directed diets and commercial programs were used more frequently. DISCUSSION: Individuals who sought bariatric surgery reported an extensive history of dieting, beginning in adolescence, that was not successful in halting progressive weight gain. Thus, the recommendation often made by insurance companies that patients delay surgery to attempt more conservative treatment options may be unwarranted, particularly in the presence of significant obesity-related comorbidities. Weight loss histories should be routinely examined during a behavioral evaluation to determine whether additional attempts at non-surgical weight loss are advisable. Future studies also are needed to explore the potential relationship between dieting history and postoperative outcome.  相似文献   
66.
Self-etching primers have recently been introduced to simplify the orthodontic bonding process. The aim of this study was to compare the effectiveness of such a product with conventional 2-stage etching and priming with 37% o-phosphoric acid and a conventional unfilled primer. Twenty consecutive patients having orthodontic bonds placed were selected to participate in this cross-mouth control study. Diagonally opposite quadrants were randomly allocated to either the self-etching primer group or the conventional etching and priming group. A total of 364 teeth were bonded with a light-cured diacrylate adhesive; bond failures were then monitored over 6 months. There were 20 bond failures (10.99%) in the self-etching primer group and 9 bond failures (4.95%) in the conventional etch and priming group over this period. The results were analyzed with the McNemar test and 95% confidence interval. The difference between the failure proportions was -0.06 with an associated 95% confidence interval of -0.121 to 0.001. This study produced weak evidence to suggest that bond failures with a self-etching primer will be higher than those with conventional etching and priming. This increased likelihood of bond failure must be weighed against the time advantage of the self-etching primer when used at the initial bonding appointment.  相似文献   
67.
68.
Current treatment of acute stroke remains unsatisfactory. This review presents experimental and clinical data which suggest that mild induced hypothermia could be a potent and practicable neuroprotective treatment of acute ischaemic stroke and intracerebral haemorrhage. Hypothermia, if proven to be safe, effective and widely practicable in patients with acute stroke, could have an enormous positive impact on reducing the burden of stroke worldwide. Critical issues that will need to be considered in a well designed randomised controlled trial of induced hypothermia in acute stroke patients are discussed.  相似文献   
69.
The tibial attachments of the individual anteromedial (AM) and posterolateral (PL) fibre bundles and the entire attachment of the anterior cruciate ligament are described, relating them to consistent bony landmarks; 55 fresh-frozen specimens were measured. The fibre bundles were separated and excised at their attachments and their peripheries marked with a pen. High-resolution scaled digital photographs were taken of each dissected specimen and transferred onto a computer for analysis. A wide variation was found when using the posterior tibial axis, the anterior tibial surface and the medial tibial spine as reference points. The most consistent measurements used the tibial interspinous “over-the-back” ridge as a datum. The attachments of the PL and AM bundles were centred 10 ± 1 mm (mean ± SD) and 17 ± 2 mm anterior to the over-the-back ridge. They were 4 ± 1 and 5 ± 1 mm, respectively, lateral to the medial tibial spine border. The positions of 6 mm circles in the posterior-medial limits of the fibre bundles (representing tunnels in a double-tunnel reconstruction) were measured. The overall dimensions of the tibial plateaux correlated significantly with many measurements. The results from this study could be used to guide ACL reconstruction techniques.  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