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   9192篇
  免费   427篇
  国内免费   23篇
耳鼻咽喉   37篇
儿科学   412篇
妇产科学   339篇
基础医学   972篇
口腔科学   125篇
临床医学   2014篇
内科学   1403篇
皮肤病学   122篇
神经病学   619篇
特种医学   324篇
外国民族医学   1篇
外科学   745篇
综合类   85篇
一般理论   28篇
预防医学   1326篇
眼科学   159篇
药学   467篇
  4篇
中国医学   9篇
肿瘤学   451篇
  2024年   10篇
  2023年   53篇
  2022年   76篇
  2021年   152篇
  2020年   144篇
  2019年   222篇
  2018年   233篇
  2017年   178篇
  2016年   205篇
  2015年   203篇
  2014年   289篇
  2013年   513篇
  2012年   645篇
  2011年   782篇
  2010年   334篇
  2009年   338篇
  2008年   707篇
  2007年   611篇
  2006年   601篇
  2005年   630篇
  2004年   642篇
  2003年   593篇
  2002年   545篇
  2001年   55篇
  2000年   37篇
  1999年   65篇
  1998年   102篇
  1997年   92篇
  1996年   72篇
  1995年   60篇
  1994年   49篇
  1993年   47篇
  1992年   34篇
  1991年   19篇
  1990年   32篇
  1989年   21篇
  1988年   26篇
  1987年   17篇
  1986年   18篇
  1985年   22篇
  1984年   31篇
  1983年   25篇
  1982年   32篇
  1981年   26篇
  1980年   12篇
  1979年   4篇
  1978年   5篇
  1974年   5篇
  1970年   5篇
  1967年   4篇
排序方式: 共有9642条查询结果,搜索用时 15 毫秒
61.
Journal of Clinical Immunology - Granulocyte transfusions are sometimes used as adjunctive therapy for the treatment of infection in patients with chronic granulomatous disease (CGD). However,...  相似文献   
62.
The relationship of race and ethnicity with standardized measures of depressive symptomatology and mental health was examined in a sample of HIV-infected African American (n = 48), Puerto Rican (n = 50), and White non-Hispanic (n = 48) women in New York City. Mean scores of women from all three racial and ethnic groups were higher than those reported for normative samples on measures of depressive symptomatology and psychological distress, and mean scores on measures of psychological well-being were lower. Puerto Rican women reported significantly higher levels of depressive symptomatology than either African American or White women. Puerto Rican women also reported significantly higher levels of psychological distress and lower levels of psychological well-being than African American women. The findings suggest that while all HIV-infected women are at risk of poor adjustment, Puerto Rican women may be especially vulnerable. They also point to the need for future research to determine what factors in these women's lives are predictive of adjustment, especially those factors amenable to intervention. © 1998 John Wiley & Sons, Inc.  相似文献   
63.

Objective

To describe the structures and processes implemented during the Association of Women’s Health, Obstetric, and Neonatal Nurses Postpartum Hemorrhage (AWHONN PPH) Project.

Design

An 18-month, multiregion, multihospital quality improvement project.

Setting/Local Problem

Fifty-eight hospitals located in Washington, DC; Georgia; and New Jersey.

Participants

Volunteer registered nurse hospital leaders implemented the AWHONN PPH bundle, which consisted of structure and process improvements.

Intervention/Measurements

The process and effectiveness of the implementation of the interventions were measured and compared between baseline and after implementation.

Results

All structures and processes showed improvement but were not fully implemented at all sites. Registered nurse participation in drills increased from 0% to 92%, quantification of blood loss increased from 5% to 45%, hemorrhage risk assessment increased from 10% to 70%, prebirth risk assessment increased from 2% to 52%, postbirth risk assessment increased from 2% to 57%, and debriefing increased from 1% to 13%. No statistically significant differences were found in the pre- and postimplementation outcomes measured (maternal deaths, blood products transfused, women with massive transfusions, peripartum hysterectomies during the birth admission, and ICU admissions for women who gave birth and/or had a postpartum hemorrhage). Participants’ self-assessments of their monthly implementation efforts (leader intensity) were not correlated with implementation fidelity (the degree to which the intervention was provided as proposed).

Conclusion

None of the 58 hospitals were able to implement all of the structure and process changes before the end of the 18-month implementation phase. This suggests that an 18-month implementation phase may be too short.  相似文献   
64.
65.
Urinary tract infection is the most frequently diagnosed kidney and urologic disease and Escherichia coli is by far the most common etiologic agent. Uropathogenic strains have been shown to contain blocks of DNA termed pathogenicity islands (PAIs) which contribute to their virulence. We have defined one of these regions of DNA within the chromosome of a highly virulent E. coli strain, CFT073, isolated from the blood and urine of a woman with acute pyelonephritis. The 57,988-bp stretch of DNA has characteristics which define PAIs, including a size greater than 30 kb, the presence of insertion sequences, distinct segmentation of K-12 and J96 origin, GC content (42.9%) different from that of total genomic DNA (50.8%), and the presence of virulence genes (hly and pap). Within this region, we have identified 44 open reading frames; of these 44, 10 are homologous to entries in the complete K-12 genome sequence, 4 are nearly identical to the sequences of E. coli J96 encoding the HlyA hemolysin, 11 encode P fimbriae, and 19 show no homology to J96 or K-12 entries. To determine whether sequences found within the junctions of the PAI of CFT073 were common to other uropathogenic strains of E. coli, 11 probes were isolated along the length of the PAI and were hybridized to dot blots of genomic DNA isolated from clinical isolates (67 from patients with acute pyelonephritis, 38 from patients with cystitis, 49 from patients with catheter-associated bacteriuria, and 27 from fecal samples). These sequences were found significantly more often in strains associated with the clinical syndromes of acute pyelonephritis (79%) and cystitis (82%) than in those associated with catheter-associated bacteriuria (58%) and in fecal strains (22%) (P < 0.001). From these regions, we have identified a putative iron transport system and genes other than hly and pap that may contribute to the virulent phenotype of uropathogenic E. coli strains.  相似文献   
66.
OBJECTIVES: To longitudinally follow a cohort of adolescents with human immunodeficiency virus (HIV) and to investigate long-term antiretroviral therapy adherence and factors associated with adherence. DESIGN, SETTING, AND PATIENTS: Adolescents infected with HIV (N = 231; mean age, 18.4 years; 72.7% female; 74.9% African American) from 13 cities throughout the United States were assessed at 3-month intervals. MAIN OUTCOME MEASURES: Self-reported adherence measures were validated by comparison with HIV-1 RNA viral load, and behavioral factors that may be associated with antiretroviral therapy adherence were assessed. RESULTS: At the initial visit, approximately 69% of the adolescents reported being adherent to antiretroviral therapy. Adolescents in the later HIV disease stage were less likely to be adherent compared with those in the earlier disease stage. Less alcohol use and being in school were associated with adherence by adolescents on weekends and over the preceding month. Longitudinal adherence was investigated among 65 subjects initially adherent with available information for at least 4 consecutive visits. The median time to nonadherence was 12 months, and failure to maintain adherence was significantly associated with younger age and depression. Among adolescents who attained an undetectable viral load, only about 50% maintained an undetectable viral load for the year. CONCLUSIONS: These findings indicate an urgent need for better interventions to assist adolescents with HIV in adhering to their medication regimens. Adolescents with advanced disease are likely to need more intervention. New treatments recently found effective for adolescent depression may assist in improving adherence for a majority of adolescents with HIV.  相似文献   
67.

Background  

Some complications of childbirth (for example, faecal incontinence) are a source of social embarrassment for women, and are often under reported. Therefore, it was felt important to determine levels of complications (against established standards) and to consider obstetric measures aimed at reducing them.  相似文献   
68.
INTRODUCTION: The authors' residency program implemented a one-week rotation at the office of a medical liability insurance company. Residents examined 30 closed malpractice claims cases and sat in on settlement discussions. OBJECTIVE: To review the residents' evaluations of their experiences and to determine whether this was a worthwhile addition to the emergency medicine (EM) residency curriculum. METHODS: This was a five-year retrospective study that reviewed residents' annual evaluations from 1994 to 1999 regarding the medical liability rotation. A five-point scale was used to score specific categories in the rotation and an open-ended section was used to collect general comments. RESULTS: A total of 179 resident evaluations were reviewed. The quality of teaching ranked in the 80th percentile, the clinical caseload ranked in the 85th percentile, and level of responsibility ranked in the 79th percentile for all EM rotations. Specific comments included "All MDs should do this in their training"; "Quite an eye opener"; and "Good exposure to legal aspects of EM." CONCLUSIONS: Overall, EM residents found the one-week rotation to be invaluable and a good learning experience. This rotation ranked above average when compared with all of our other EM residency rotations.  相似文献   
69.
Health-related productivity assessments typically focus on chronic conditions; however, acute conditions, particularly colds, have the potential to cause substantial health-related productivity losses because of their high prevalence in working-age groups. This article presents the findings of a study conducted to estimate productivity loss due to cold by using a telephone-administered survey that measured three sources of loss: absenteeism, on-the-job productivity, and caregiver absenteeism. Each cold experienced by a working adult caused an average of 8.7 lost work hours (2.8 absenteeism hours; 5.9 hours of on-the-job loss), and 1.2 work hours were lost because of attending to children under the age of 13 who were suffering from colds. We conclude that the economic cost of lost productivity due to the common cold approaches $25 billion, of which $16.6 billion is attributed to on-the-job productivity loss, $8 billion is attributed to absenteeism, and $230 million is attributed to caregiver absenteeism.  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