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   1832篇
  免费   133篇
  国内免费   5篇
耳鼻咽喉   10篇
儿科学   63篇
妇产科学   56篇
基础医学   221篇
口腔科学   20篇
临床医学   360篇
内科学   303篇
皮肤病学   23篇
神经病学   170篇
特种医学   35篇
外科学   161篇
综合类   16篇
一般理论   5篇
预防医学   266篇
眼科学   17篇
药学   112篇
中国医学   5篇
肿瘤学   127篇
  2023年   19篇
  2022年   29篇
  2021年   41篇
  2020年   33篇
  2019年   50篇
  2018年   55篇
  2017年   47篇
  2016年   50篇
  2015年   42篇
  2014年   75篇
  2013年   118篇
  2012年   117篇
  2011年   138篇
  2010年   83篇
  2009年   73篇
  2008年   111篇
  2007年   123篇
  2006年   107篇
  2005年   111篇
  2004年   98篇
  2003年   76篇
  2002年   87篇
  2001年   15篇
  2000年   11篇
  1999年   25篇
  1998年   33篇
  1997年   17篇
  1996年   10篇
  1995年   10篇
  1994年   14篇
  1993年   11篇
  1992年   13篇
  1991年   8篇
  1990年   5篇
  1989年   12篇
  1988年   4篇
  1987年   9篇
  1986年   5篇
  1985年   6篇
  1984年   5篇
  1983年   5篇
  1981年   5篇
  1980年   7篇
  1979年   10篇
  1978年   5篇
  1977年   5篇
  1972年   3篇
  1971年   6篇
  1969年   3篇
  1964年   3篇
排序方式: 共有1970条查询结果,搜索用时 10 毫秒
1.
Fetal scalp blood sampling (FSBS), in conjunction with fetal heart rate monitoring, is a method of fetal surveillance that may avoid cesarean delivery of the healthy fetus or indicate the need for immediate delivery of a compromised fetus. Some researchers have recently begun to question the efficacy of FSBS. In this article, three nurse-midwives discuss FSBS as a tool in assessing fetal well-being during labor and consider whether FSBS is a nurse-midwifery procedure.  相似文献   
2.
Background: This is the second of two papers using qualitative methods from a study of an intervention for family members affected by close relatives' substance misuse problems.

Participants: 168 primary healthcare professionals (PHCPs: GPs, practice nurses and health visitors) working in general practices in two areas of England, and who took part in the study.

Data sources: Recruitment and post-session forms completed by PHCPs; telephone interviews with each PHCP 12 weeks after recruitment of a family member; interviews with PHCPs at the end of the study.

Results: At the end of the project PHCPs were overwhelmingly positive about the family member intervention and about primary care as the appropriate site. Difficulties were encountered, however, in identifying and engaging affected family members, who were often excluded on grounds of the complexity of their problems or the level of their distress. Shortage of PHCP time and other practice-related factors added to the difficulty. Active work by a PHCP was often necessary in order to make the link between presenting symptoms of physical or mental ill-health and the existence of a family substance misuse problem. When family members were identified and recruited, PHCPs were usually positive about what was achieved. Nearly all were in favour of an approach that combined giving a self-help manual with some follow-up contact with a family member as needed.

Conclusions: Taken in conjunction with statistical outcome findings of significant reductions in symptoms and changes in ways of coping, plus qualitative analysis of the views of family members, the present results encourage the view that a flexible form of this intervention should be developed for use in primary healthcare, and that further work should build on existing strengths and attempt to overcome weaknesses identified.  相似文献   
3.
Government reform of the NHS in the UK has sought to increase the involvement of doctors (clinicians) in hospital management. Using frameworks from the psychological contract and organisational misbehaviour literatures, this paper examines the processes involved when clinicians assume management roles. This literature seeks to explain breaches to expectations regarding prior agreements with management and subsequent actions of 'getting even' as a result of breaches to the employment relationship. A qualitative methodology using interviews was undertaken, which identified two distinct groups of clinician-manager. Investors actively pursued a management opportunity as an alternative to clinical medicine, whilst reluctants tended to assume a management role to protect particular specialities from outside influence or from those they thought would be inappropriate clinician-managers. Investors and reluctants often had very little prior experience of management and managers and had problems reconciling their dual clinician-management role. Poor relationships with hospital managers who often had no understanding of their dual responsibilities led to tensions and conflict, which questions continued developments in this important area of UK health policy. Suggestions for improving this process are outlined.  相似文献   
4.
5.
6.
The study reports the pre-post findings from a controlled comparative evaluation of treatments for bulimia nervosa. These pre-post results allow comparison of the hypnobehavioural and cognitive behavioural treatments with a waiting list control group and a comparison of the immediate effects of the two modalities. One hundred and thirty subjects were screened to enter the study. Seventy-eight subjects entered the investigation after being randomly allocated to either a waiting list control group, or to hypnobehavioural or cognitive behavioural groups. The treatments were delivered individually and matched in duration (8 weeks) and the number of sessions. Pre to posttreatment outcome indicated significant differences between the control group and the two treatments in reductions in bulimic behaviours and related eating pathology. The immediate effects of both treatments were equal. There were no differences at posttreatment between the treatments in abstinence from either bingeing or purging. The treatment effects were also similar to the immediate effects obtained by longer therapeutic approaches.  相似文献   
7.
OBJECTIVE: We performed a prospective, randomized clinical trial to compare the usefulness of the minute ventilation test (MVT) with clinical judgement in predicting readiness for extubation in preterm newborns with respiratory distress syndrome requiring surfactant therapy and mechanical ventilation. STUDY DESIGN: A total of 42 preterm infants with respiratory distress syndrome were randomized when they reached preselected ventilator settings. The primary outcome measure was the time from study entry to extubation, provided the infant remained extubated for at least 24 hours. RESULTS: Infants evaluated by the MVT were extubated in a significantly shorter period of time (mean of 8 hours) than those evaluated clinically (mean of 36 hours). The extubation failure rate was similar in the two groups. CONCLUSION: The MVT is an easily performed objective measure that can be used to predict readiness for extubation in preterm infants. In this study, it significantly shortened the time for extubation and was not associated with a higher rate of reintubation.  相似文献   
8.
BACKGROUND: Chronic cough often lasts for more than 1 year and is associated with airway inflammation. The effect of inhaled corticosteroids on symptom severity and inflammatory mediator levels in these patients is unknown. OBJECTIVE: We sought to determine whether inhaled corticosteroids reduce cough severity and sputum mediator concentrations in patients with chronic persistent cough. METHODS: We performed a double-blind, randomized, placebo-controlled crossover study with inhaled fluticasone, 500 microg twice daily, and placebo for 14 days in 88 patients with cough for more than 1 year, with normal chest radiography and spirometry results. Outcome measures were a daily cough visual analogue scale and induced sputum concentrations of eosinophilic cationic protein (ECP), myeloperoxidase, leukotriene B(4) (LTB(4)), leukotrienes C(4)/D(4)/E(4) (cysteinyl leukotrienes [Cys-LTs]), prostaglandin E(2) (PGE(2)), IL-8, and TNF-alpha. Sputum cell counts, exhaled nitric oxide levels, and carbon monoxide levels were also measured. RESULTS: There was a significant improvement in the cough visual analogue scale after inhaled fluticasone compared with placebo (mean difference, 1.0; 95% CI, 0.4-1.5; P <.001). LTB(4), Cys-LT, and PGE(2) levels were increased in all causes of cough. Sputum ECP counts, exhaled nitric oxide levels, and carbon monoxide levels decreased significantly after inhaled fluticasone. There was no change in sputum cell counts and other mediator concentrations. CONCLUSION: Cough severity and sputum ECP levels are modestly reduced by inhaled corticosteroids in patients with chronic cough persisting for more than 1 year. LTB(4), Cys-LT, PGE(2), IL-8, myeloperoxidase, and TNF-alpha levels are unaltered by this therapy. This raises the possibility that drugs targeted to reduce the effects of these mediators might be of benefit in chronic persistent cough.  相似文献   
9.
Human populations have lived at high altitudes for lengths of time which are likely to be shortest in Colorado, intermediate in Peru, and longest in Tibet. We hypothesized that the longest-resident high-altitude populations have beccome better adapted than shorter-resident groups as a result of superior abilities to transport and/or utilize O2. Because birth weights are reduced at high altitude and decreased birth weight is associated with increased infant mortality, our criterion for assessing adaptation was preservation of birth weights close to values associated with the lowest mortality risk. Colorado (3,100 m) and Peru (4,300 m) birth weights averaged 3,186±70 g and 2,920±90 g respectively. A sample of 15 births from Tibet (3,658 m) weighed 3,307±110 g which was more than their altitude counterparts and close to sea-level norms. Pregnancy increased maternal ventilation at all three study sites. In Peru, the resultant elevation in arterial O2 saturation offset the pregnancy-induced fall in hemoglobin concentration to preserve arterial O2 content at nonpregnant levels. Arterial O2 content decreased slightly in Colorado and more markedly in Tibet in the pregnant compared to the nonpregnant state. The Colorado and Peru women with the greatest rise in ventilation and ventilatory sensitivity to hypoxia produced the heaviest birthweight infants, suggesting that maternal arterial oxygenation was an important determinant of fetal growth. The pregnant women in Tibet did not have higher levels of arterial O2 content than the pregnant Colorado or Peru women nor did maternal arterial O2 content relate to birth weight in Tibet. Infant birth weight in Tibet tended to be correlated with the ratio of uterine artery to common iliac artery mean flow velocity, suggesting that redistribution of lower-extremity blood flow to favor the uterine circulation may have acted to augment uterine O2 delivery in the Tibet women. Thus, the limited data available suggested that the Tibetans may be better adapted as judged by less fetal growth retardation and may utilize maternal O2 transport mechanisms not reliant upon increased arterial O2 content.  相似文献   
10.
Therapist affirmation was examined in two studies, the first with cognitive-behavioral therapy (CBT, N = 22) and the second with time-limited dynamic psychotherapy (TLDP, N = 20). Affirmation was identified using Structural Analysis of Social Behavior (SASB), and sequential analysis used to gauge its impact on therapy process and outcome. It was hypothesized that affirmation would correspond with patients' continuation of the current topic of conversation, but relate negatively to outcome if generally offered after maladaptive statements. Patients in Study 1 (CBT) were more likely to continue a topic after it was affirmed, and affirmation of maladaptive statements reliably differentiated patients who evidenced clinically significant change from those who did not at termination and at 12-months posttreatment. Affirmation of maladaptive statements in Study 2 (TLDP) corresponded with poorer outcome in relationships with significant others, but unexpectedly with improvements in self-concept.  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