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   3353篇
  免费   382篇
  国内免费   19篇
耳鼻咽喉   25篇
儿科学   137篇
妇产科学   66篇
基础医学   438篇
口腔科学   107篇
临床医学   447篇
内科学   616篇
皮肤病学   53篇
神经病学   284篇
特种医学   253篇
外科学   330篇
综合类   148篇
一般理论   1篇
预防医学   327篇
眼科学   77篇
药学   246篇
中国医学   2篇
肿瘤学   197篇
  2022年   39篇
  2021年   101篇
  2020年   53篇
  2019年   76篇
  2018年   89篇
  2017年   58篇
  2016年   54篇
  2015年   55篇
  2014年   75篇
  2013年   112篇
  2012年   158篇
  2011年   121篇
  2010年   79篇
  2009年   78篇
  2008年   133篇
  2007年   149篇
  2006年   112篇
  2005年   131篇
  2004年   111篇
  2003年   107篇
  2002年   103篇
  2001年   94篇
  2000年   96篇
  1999年   98篇
  1998年   52篇
  1997年   48篇
  1996年   62篇
  1995年   45篇
  1994年   46篇
  1993年   39篇
  1992年   63篇
  1991年   63篇
  1990年   72篇
  1989年   66篇
  1988年   68篇
  1987年   52篇
  1986年   60篇
  1985年   50篇
  1984年   49篇
  1983年   48篇
  1982年   36篇
  1980年   35篇
  1979年   39篇
  1978年   33篇
  1977年   29篇
  1971年   37篇
  1970年   29篇
  1969年   31篇
  1967年   28篇
  1966年   31篇
排序方式: 共有3754条查询结果,搜索用时 10 毫秒
91.
A scale is developed for measuring the overprotecting vs. optimal developmental stimulation tendencies for parents of physically “vulnerable” children. A series of items were administered to parents whose parenting techniques had been rated as either highly overprotective or as optimal by a group of MDs and other professionals. Correlations were estimated between each of the items and parental tendencies as rated by professionals. Twenty-eight items were selected that provided maximum prediction of overprotection. The resulting R2 was extraordinarily high (.94). Coefficient alpha and test-retest coefficients were acceptable. It is hoped that release of the new instrument (VCOPS) at this time will allow others to join in determining the clinical and experimental validity of this scale.  相似文献   
92.
An attempt was made to replicate the results of an earlier confirmatory factor analysis of the seven traditionally employed physical risk factors for CHD. As with the first investigation, a two-factor solution was confirmed; only family history loaded on factor 1; the remaining six risk variables (smoking, serum cholesterol, blood pressure, diet, exercise, and weight control) comprised factor 2. These findings may reflect a broad personality trait, i.e., generalized lack of self-control, which could underlie much CHD risk not associated with a family history of heart disease. Implications are drawn for research and practice in the areas of cardiac rehab and prevention.  相似文献   
93.
Thirty Type A males and 30 Type A females were administered an expanded version of the Structured Interview designed to assess 11 Type A subcomponents. The purpose was to determine whether males and females follow different subcomponent routes in achieving their Type A status. As predicted, males scored higher than females on two of four anger-related variables. Contrary to prediction, males scored higher than females on the subcomponent of exaggerated social control. These findings were interpreted as providing some support for the notion of differing gender-related subcomponent routes for achieving Type A status. These findings also may have implications for the higher incidence of coronary heart disease in high TABP males vs. females.  相似文献   
94.
In the current study, the actor–observer effect is tested with both mock parole board members and the public evaluating the responsibility of parole board members for a decision resulting in a parolee reoffending and committing a murder. Participants (two samples with a combined N = 1317) were randomly assigned to act as a mock parole board member and make a decision (which ended in the parolee reoffending) or as a member of the public who read a story about the same parole decision and outcome. Findings suggest that the traditional actor–observer asymmetry emerged across blame and responsibility concepts, emotion and moral judgments. Overall, the public held harsher judgments than the mock parole board members. Implications regarding self-enhancement, methodology and attribution theory are discussed.Key words: actor–observer, attributions, blame, decision-making, emotion, parole, responsibility

Parole has been a part of corrections reform since the early twentieth century, and it shares many goals with a more rehabilitative criminal justice approach seen gaining momentum recently (Cullen, 2017; Petersilia, 2000). Perceptions that prison sentences were too harsh and did not allow any room for rehabilitation spurred support for a more lenient approach to parole, and models of releasing less violent inmates that have shown good behavior were adopted (Clear & Cole, 1997). In general, there are two types of parole decisions; discretionary and mandatory parole (Maruschak & Bonczar, 2013). Discretionary parole involves a decision process through which parole board members review an inmate’s files and decide whether to grant or deny supervised release (parole). There is no required action given to the board, but the action is left up to the discretion of the board. In contrast, mandatory parole is a decision process by which inmates are released under specific circumstances after they have served a certain period of time in prison and do not have major violations or other factors barring their release (Hughes et al., 2001). Under mandatory release guidelines, the parole board is often obligated to release inmates to supervised release, usually based on determinate sentencing and good behavior, unless some major factor prevents such action (Abadinsky, 2012). Recently, discretionary parole has been used at a higher rate than mandatory parole, creating a trend over the past several years (Kaeble, 2018; Maruschak & Bonczar, 2013).In the United States, there are currently about 875,000 inmates on parole, with over 450,000 inmates being released on parole in 2016 (Kaeble, 2018). With an increase in discretionary parole decisions and a large parole population, the parole board likely faces scrutiny for the outcomes of its decisions and is held accountable by the public for ensuring safety and economy (e.g. Abadinsky, 2012; Mackenzie, 2001; National Parole Resource Center, 2012; Paparozzi & Guy, 2009). Parole board members’ perspectives and the public’s perspective might differ as they relate to how parole decisions are perceived and the accountability of the boards’ decisions. This divergence is important because legislation applicable to parole board decisions is intended to incorporate both perspectives, and any dialogue about parole should involve an attempt at mutual understanding. However, it is possible that the divergence in perspectives is due to experience and observational standpoint. The purpose of the current study is to apply an attribution framework to better understand the difference between perspectives of actors (parole board members) and observers (the public) by using a mock parole decision-making paradigm and comparing both parole board and public perspectives on the decision process and outcome with a focus on blame and responsibility for negative outcomes.  相似文献   
95.
96.
97.
Transforming growth factor-beta1 (TGF-beta1) is a fibrogenic cytokine that is involved in postinjury repair and is implicated in the etiology of postsubarachnoid hemorrhage (SAH) chronic communicating hydrocephalus. TGF-beta1 was measured by enzyme-linked immunosorbant assay (ELISA) in sequential samples of cerebrospinal fluid (CSF) in 11 patients with hydrocephalus after SAH; levels were seen to be biphasically elevated and sources were investigated. TGF-beta1 levels were compared with albumin levels that estimated CSF blood content. Control samples from nonhemorrhagic hydrocephalics were tested similarly. Mean total TGF-beta1 levels were elevated to 4400+/-3435 (+/-SD) pg/mL greater than control levels of 97+/-42 at 1 to 2 days posthemorrhage. Thereafter, levels fell to 714+/-401 by 5 to 6 days posthemorrhage, then rose to a second peak of 1667+/-774 at 9 to 10 days posthemorrhage, remaining significantly increased until 19 days posthemorrhage (P = 0.007). The first peak probably derived from extravasated platelets and correlated with increased albumin levels in the CSF. The second TGF-beta1 peak rose greater than CSF albumin levels that had stabilized at this time, and thus was attributed to a tissue-specific response rather than a re-bleed. TGF-beta1 was detected in the choroid secretory epithelium from controls, but levels were greater in SAH patients at 10 to 12 days posthemorrhage. The authors conclude that the elevated levels of TGF-beta1 in CSF after SAH are derived initially from blood and later from endogenous sources such as the choroid plexus.  相似文献   
98.
It is well documented that myopia is associated with an increase in axial length of the posterior vitreous chamber. Whether equatorial or transverse dimensions are likewise affected in myopia is relevant to further understanding of the development of ametropia. We have utilised a computing method to determine retinal contour from real eye measurements of keratometry, A-scan ultrasonography and peripheral refraction as a means of assessing the transverse dimensions of the vitreous chamber. This technique has been applied to a 21-year-old female Caucasian anisomyope with a refractive error of R −1.50/−0.50 × 130 and L −4.00/−0.50 × 160. Anisomyopia offers a special opportunity for inter-eye comparison of different degrees of myopia. The repeatability of the technique was assessed by taking 10 separate sets of the aforementioned measurements and thus generating 10 retinal contours for each eye. We conclude that this method is repeatable and is capable of demonstrating differences between anisomyopic eyes although validation against in vivo measurements is required.  相似文献   
99.
In vivo antigenic variation of Campylobacter flagellin.   总被引:6,自引:0,他引:6       下载免费PDF全文
Campylobacter coli VC167 cells producing either antigenic phase 1 (P1) or phase 2 (P2) flagellins (as determined by characteristic protein and DNA patterns) were used to infect rabbits by the removable intestinal tie-adult rabbit diarrhea (RITARD) procedure. Rabbits infected with P2 cells shed predominantly P2 cells throughout the infection; in rabbits infected with P1 cells, a transition of fecal isolates from P1 to P2 was observed.  相似文献   
100.
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