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   456篇
  免费   45篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   15篇
妇产科学   8篇
基础医学   40篇
口腔科学   9篇
临床医学   30篇
内科学   115篇
皮肤病学   9篇
神经病学   19篇
特种医学   2篇
外科学   49篇
综合类   7篇
一般理论   2篇
预防医学   30篇
眼科学   17篇
药学   43篇
中国医学   3篇
肿瘤学   103篇
  2024年   1篇
  2023年   9篇
  2022年   16篇
  2021年   23篇
  2020年   17篇
  2019年   22篇
  2018年   24篇
  2017年   24篇
  2016年   15篇
  2015年   17篇
  2014年   33篇
  2013年   27篇
  2012年   36篇
  2011年   37篇
  2010年   22篇
  2009年   18篇
  2008年   27篇
  2007年   28篇
  2006年   25篇
  2005年   27篇
  2004年   29篇
  2003年   11篇
  2002年   11篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
排序方式: 共有502条查询结果,搜索用时 31 毫秒
1.
PURPOSE: To assess the educational impact of Accreditation Council for Graduate Medical Education resident work-hour limits implemented in July 2003. METHOD: All trainees in all 76 accredited programs at two large teaching hospitals were surveyed between May and June 2003 (before work-hour reductions) and then between May and June 2004 (after work-hour reductions) about hours, education, and fatigue. Based on changes in weekly duty hours, 13 programs experiencing substantial reduction in hours were classified into a reduced-hours group. Differences in assessments of educational endpoints before and after policy implementation by trainees in the reduced-hours group were compared with those in other programs to control for potential temporal trends, using two-way ANOVA with interaction. RESULTS: The number of respondents was 1,770 (60% response rate). The reduced-hours group reported a significant decrease in time spent directly caring for patients (from 48.5 to 42.3 mean h/wk, P = 0.03), but the volume of important clinical experiences, including procedures, was preserved, as was the sense of clinical preparedness. On 22 questions related to educational quality and adequacy, only three differences in differences were significant, with the reduced-hours group reporting a relative increase in opportunities for research, decrease in quality of faculty teaching, and decrease in educational satisfaction. The percentage of trainees reporting frequent negative effects of fatigue dropped more in the reduced-hours programs than in the other programs (P < 0.05). CONCLUSION: This study shows that it may be possible to reduce residents' hours--and the perceived adverse impact of fatigue--while generally preserving the self-assessed quality, quantity, and outcomes of graduate medical education.  相似文献   
2.
STUDY OBJECTIVE: To describe our experience and technique of total laparoscopic radical hysterectomy with pelvic lymphadenectomy, which is the largest single- institution study. DESIGN: Retrospective, nonrandomized study (Canadian Task Force classification II-2). SETTING: Private hospital. PATIENTS: Two hundred forty-eight patients with International Federation of Gynecology and Obstetrics stage IA2 (n = 32) and IB1 (n = 216) of cancer of the cervix. INTERVENTION: Total laparoscopic type III radical hysterectomy with bilateral pelvic lymphadenectomy was done. Simple repetitive steps were used to perform this surgery and develop an easily replicable technique. Harmonic Shears, bipolar coagulation, and vascular clips were used. Resection of the cardinal and uterosacral ligaments was performed with LigaSure (LigaSure Vessel Sealing System; Valleylab, Tyco Healthcare, Boulder, CO) or the Harmonic Shears (Ethicon Endo-Surgery, Inc., Cincinnati, OH). Pelvic lymph node dissection was done. MEASUREMENTS AND MAIN RESULTS: Histopathologically, there were 183 (73%) cases of squamous carcinoma, 52 (20%) adenocarcinomas, and 13 (5%) adenosquamous carcinomas. Four patients needing anterior exenteration because of bladder involvement were excluded from data analyses. The operation was performed entirely by laparoscopy in all patients and by the same surgical team. The patients' median age was 61 years. The median operative time was 92 minutes (range 65-120 minutes). The median number of resected pelvic nodes was 18. The median blood loss was 165 mL. The median length of stay was 3 days. All 15 intraoperative complications were tackled laparoscopically. No patients were converted to the open technique. There were no deaths in our series. Seventeen patients had complications within 2 months of surgery. Seven patients had recurrences after a median follow-up of 36 months. CONCLUSION: Our technique of total laparoscopic radical hysterectomy, developed over 248 cases, can be performed safely. It is an easily replicable technique. This procedure reduces the morbidity associated with abdominal radical hysterectomy. All of the complications can also be tackled laparoscopically, which does not further add to the morbidity.  相似文献   
3.

Background

Although the older population is increasing worldwide, there is a marked deficit in the number of persons trained in geriatrics. It is now recognized that early detection and treatment of geriatric syndromes (frailty, sarcopenia, anorexia of aging, and cognitive decline) will delay or avert the development of disability.

Objectives

To identify simple screening programs available for primary health professionals to identify geriatric syndromes.

Data sources

PubMed for the last 5 years and study authors.

Results

A number of screening programs for early detection of geriatric syndromes have been developed for use by primary care health providers, for example, EasyCare, Gérontopôle Frailty Screening Tool, the Rapid Geriatric Assessment, the Kihon Checklist, and others.

Limitations

This is an evolving area with limited information on the outcomes of intervention and possible harms.

Conclusion

Validated screening programs exist but more work is required to determine their utility in improving outcomes of older persons.  相似文献   
4.
Synthetic pyrethroids are the major insecticides used widely in agriculture and household pest control. Deltamethrin (DM), a widely used type II pyrethroid insecticide, is a relatively potent neurotoxicant. 3-Phenoxybenzoic acid (PBA) is the major metabolite formed due to metabolism of DM. In order to illustrate the toxic response of zebrafish embryos/larvae to DM and PBA the present research was carried out. For this 4hpf embryos were treated with two concentrations of DM (100 and 200?μg/L) for 48?h and PBA (1000 and 2000?μg/L) for 96?h or 99.9% ethanol (solvent control). Early life stage parameters were observed at specified time points. DM-treated embryo/larvae exhibited increased mortality, delay in hatching time, decrease in percentage of hatched embryos, increase of heartbeat rate and decrease in blood flow; lightening of body and eye pigmentation in a dose dependent manner. Pericardial and yolk sac edema along with were also caused by DM. Along with these crooked notochord, tail deformation was noticed in hatched and unhatched embryos. In case of PBA treated embryos and larvae, increased embryos/larvae length and yolk sac size were observed. Other abnormalities like edema (yolk sac and pericardial), decreased eye and body pigmentation were also observed but in some embryos only. These were not as severe as observed in parental compound indicating that DM is more toxic than its metabolite PBA. The data contributes to a better understanding of the potential consequences of fish exposed to DM and PBA.  相似文献   
5.
Objective: Severe diarrhea-predominant irritable bowel syndrome (IBS-D) is associated with decreased health-related quality of life (HRQOL) and increased health care costs. Treatment recommendations for IBS-D often start with traditional pharmacotherapy (TP), with escalation to alosetron, rifaximin or eluxadoline if there is no success. There has been no previous head-to-head clinical trial comparing IBS-D treatment outcome for alosetron versus TP. This study, GSK protocol S3B30020, evaluated resource use, work productivity, health-related quality of life and global symptom response in women with IBS-D who were treated with alosetron or TP.

Methods: A total of 1956 patients who met criteria for severe IBS-D were randomized to treatment with alosetron 1?mg twice daily (BID) or only TP for up to 24 weeks. Work productivity and resource use were evaluated by standard questionnaires, HRQOL by the IBSQOL instrument and IBS symptoms by the Global Improvement Scale (GIS).

Results: Compared to only TP, alosetron-treated patients reported: (1) fewer clinic/office visits for any health problem (p?=?.0181) or for IBS-D (p?=?.0004); (2) reduced use of over-the-counter medications for IBS-D (p < .0001); (3) fewer days of lost work productivity (p < .0001); (4) decreased restriction of social and outdoor activities (p < .0001); and (5) greater global improvement in IBS-D symptoms (p < .0001). Alosetron treatment improved HRQOL scores for all domains (p < .0001). Incidence of adverse events during alosetron use was not remarkable and was similar to that previously reported.

Conclusions: Alosetron 1?mg BID significantly reduced health care utilization and lost productivity, and significantly improved global IBS symptoms, HRQOL, and participation in outdoor and social activities compared with treatment response to TP.  相似文献   

6.
There has been a significant increase in the past few decades in the number of children receiving noninvasive positive airway pressure (PAP) therapy at home. At present, PAP therapy can be successfully used in children of all ages, for a variety of indications. Data acquired from PAP devices is clinically useful, providing objective information regarding adherence, leak, and efficacy of PAP therapy. However, guidelines outlining a standardized approach to interpretation of PAP device data in pediatrics is currently lacking. Given the rapidly expanding use of PAP therapy in pediatric practice, we aim to provide an overview of the interpretation of data reports, otherwise called “data downloads,” from PAP devices and illustrate how they can be used to guide clinical care.  相似文献   
7.
8.
Artificial intelligence (AI) demonstrated by machines is based on reinforcement learning and revolves around the usage of algorithms. The purpose of this review was to summarize concepts, the scope, applications, and limitations in major gastrointestinal surgery. This is a narrative review of the available literature on the key capabilities of AI to help anesthesiologists, surgeons, and other physicians to understand and critically evaluate ongoing and new AI applications in perioperative management. AI uses available databases called “big data” to formulate an algorithm. Analysis of other data based on these algorithms can help in early diagnosis, accurate risk assessment, intraoperative management, automated drug delivery, predicting anesthesia and surgical complications and postoperative outcomes and can thus lead to effective perioperative management as well as to reduce the cost of treatment. Perioperative physicians, anesthesiologists, and surgeons are well-positioned to help integrate AI into modern surgical practice. We all need to partner and collaborate with data scientists to collect and analyze data across all phases of perioperative care to provide clinical scenarios and context. Careful implementation and use of AI along with real-time human interpretation will revolutionize perioperative care, and is the way forward in future perioperative management of major surgery.  相似文献   
9.
Background  Cystic fibrosis (CF) patients have chronic pancreatic insufficiency leading to malabsorption of fat-soluble vitamins, including vitamin D which can contribute to poor skeletal health and respiratory function.
Objective  This study evaluated the prevalence of vitamin D insufficiency and its impact on bone and respiratory health in adults with CF.
Design and measurements  This was a retrospective study in which data were collected from medical records over a 2-year period. Data included patient demographics, lung function, biochemical data, bone mineral densities, X-rays and ascertainment of use of vitamin supplements. Data were collected from medical records at a single accredited CF Center. Serum 25-hydroxyvitamin D [25(OH)D] levels and bone mineral density studies were also collected.
Patients  A total of 185 adults with CF were identified with a mean age of 29 ± 9 years.
Results  The prevalence of vitamin D insufficiency [25(OH)D < 75 nmol/l] was 76%. Mean serum 25(OH)D concentrations were 58·8 ± 30 nmol/l. Use of specific vitamin D supplementation was protective against vitamin D insufficiency whereas use of multivitamins was not. There was a small, but significant, positive association between serum 25(OH)D and FEV1 per cent predicted after controlling for age, gender, BMI and race ( R 2 = 0·30, P  < 0·001). A high prevalence (27%) of vertebral fractures was detected on lateral chest X-ray.
Conclusions  The prevalence of vitamin D insufficiency and poor skeletal health is high in the US CF population. Vitamin D status appears to be positively associated with lung function. Prospective studies to examine the impact of correction of vitamin D insufficiency on skeletal and lung health in adult CF are warranted.  相似文献   
10.
DNA-damaging antibiotics such as ciprofloxacin induce biofilm formation and the SOS response through autocleavage of SOS-repressor LexA in Pseudomonas aeruginosa. However, the biofilm-SOS connection remains poorly understood. It was investigated with 96-well and lipid biofilm assays. The effects of ciprofloxacin were examined on biofilm stimulation of the SOS mutant and wild-type strains. The stimulation observed in the wild-type in which SOS was induced was reduced in the mutant in which LexA was made non-cleavable (LexAN) and thus SOS non-inducible. Therefore, the stimulation appeared to involve SOS. The possible mechanisms of inducible biofilm formation were explored by subproteomic analysis of outer membrane fractions extracted from biofilms. The data predicted an inhibitory role of LexA in flagellum function. This premise was tested first by functional and morphological analyses of flagellum-based motility. The flagellum swimming motility decreased in the LexAN strain treated with ciprofloxacin. Second, the motility-biofilm assay was performed, which tested cell migration and biofilm formation. The results showed that wild-type biofilm increased significantly over the LexAN. These results suggest that LexA repression of motility, which is the initial event in biofilm development, contributes to repression of SOS-inducible biofilm formation.  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