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   2069篇
  免费   124篇
  国内免费   10篇
耳鼻咽喉   26篇
儿科学   25篇
妇产科学   22篇
基础医学   264篇
口腔科学   256篇
临床医学   155篇
内科学   539篇
皮肤病学   29篇
神经病学   221篇
特种医学   41篇
外科学   234篇
综合类   7篇
一般理论   1篇
预防医学   125篇
眼科学   20篇
药学   150篇
中国医学   5篇
肿瘤学   83篇
  2024年   1篇
  2023年   29篇
  2022年   52篇
  2021年   92篇
  2020年   60篇
  2019年   80篇
  2018年   98篇
  2017年   77篇
  2016年   78篇
  2015年   99篇
  2014年   112篇
  2013年   131篇
  2012年   190篇
  2011年   195篇
  2010年   94篇
  2009年   80篇
  2008年   122篇
  2007年   110篇
  2006年   106篇
  2005年   94篇
  2004年   67篇
  2003年   62篇
  2002年   46篇
  2001年   12篇
  2000年   19篇
  1999年   19篇
  1998年   9篇
  1997年   7篇
  1996年   10篇
  1995年   6篇
  1994年   4篇
  1993年   5篇
  1992年   4篇
  1991年   6篇
  1990年   5篇
  1989年   3篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1983年   1篇
  1982年   2篇
  1979年   1篇
  1972年   1篇
  1964年   1篇
  1948年   1篇
  1943年   1篇
  1939年   1篇
  1937年   1篇
排序方式: 共有2203条查询结果,搜索用时 0 毫秒
61.
62.
63.
To evaluate priapism rates in individuals <18 years of age with sickle cell disease (SCD) at a referral center. An evaluation was made of 599 consecutive male patients with SCD, separated according to type of hemoglobinopathy (HbSS, HbSC and HbS-β-thalassemia). Age at first episode and number of episodes were recorded. Cases of sickle cell trait were excluded. Mean age was similar in all groups. Overall, priapism occurred in 3.6 % of patients (5.6 % of those with HbSS and 1.1 % of those with HbSC; P = 0.01). In HbSS patients, the prevalence rate of priapism was from 3.5 (CI 95 % 0.94-13.4) when compared with patients with HbSC. No patient with β-thalassemia had priapism. Mean follow-up was 39.7 months (range 1-202 months). Since 91 % of patients with priapism had HbSS, this group was evaluated separately, revealing a rate of priapism of 1.6 % in patients <10 years and 8.3 % in those ≥ 10 years of age (P = 0.002). Regarding priapism in HbSS patients ≥ 10 years (8.3 %) when compared with patients <10 years (1.6 %), the prevalence rate was from 3.3 (CI 95 % 1.1-9.5). Duration of follow-up was not correlated with priapism (P = 0.774). Forty-seven patients were lost to follow-up. Telephone contact was successful with 14/22 patients with priapism, 50 % of whom had required hospital treatment. Most episodes (86 %) occurred at night, always during sleep. Medical interventions were required in 13 cases as follows: intravenous hydration (n = 4), corpora cavernosa puncture and drainage (n = 7) and corpus cavernosum-corpus spongiosum shunts (n = 2). The prevalence of priapism in children <18 years of age with SCD was 3.6 %, lower than previously reported. Prevalence was higher in HbSS patients, increasing in patients >10 years of age. Most episodes occurred at night and half of the patients required some form of urological procedure.  相似文献   
64.
65.
66.
67.

Introduction

Bacterial contamination from viscerotomy is a barrier to natural orifice translumenal endoscopic surgery (NOTES). The aim of this survival study is to evaluate pure (totally) transvaginal NOTES bacterial contamination compared with laparoscopy in pigs.

Methods

Twelve adult female pigs underwent peritoneoscopy with liver and peritoneal biopsies, using either laparoscopy (Glap, six animals) or pure transvaginal (GNOTES) access, and were maintained alive for 7 days. In all animals, blood cultures were taken at baseline, and after 24 h and 7 days postoperatively. Swab cultures from vagina (GNOTES) and skin (Glap) were obtained pre- and post-antisepsis. Peritoneal fluid culture was obtained at necropsy. For statistical analysis, Glap and GNOTES were compared for presence of positive bacterial cultures (qualitative bacterial analysis) using Fisher’s test, with level of significance set at p < 0.05.

Results

All animals had good postoperative outcome. One animal had transient perioperative bleeding from a transvaginal access. Two animals in Glap and one in GNOTES had positive blood cultures after the procedure. All animals from GNOTES and Glap presented with mixed flora pre-antisepsis. After antisepsis, one animal (GNOTES) presented with a positive vaginal swab culture (a single bacterial strain was identified). There was no positive skin swab culture in Glap. There were no signs of intra-abdominal infection at necropsy. In two animals, one from Glap and another from GNOTES, intra-abdominal culture was positive for Corynebacterium spp. and Escherichia coli, respectively. There was no correlation between the bacterial flora found at the access site and in the peritoneal cultures.

Conclusions

Pure transvaginal peritoneoscopy with liver and peritoneal biopsy in swine is feasible and associated with bacterial contamination comparable to laparoscopy. Peritoneal bacterial contamination was clinically insignificant after 1 week postoperatively. Preoperative antisepsis provided significant reduction of bacterial load prior to transvaginal and laparoscopic procedures.  相似文献   
68.
Chronic wounds that fail to heal are a common complication of diabetes mellitus and the most common precipitating reason for nontraumatic lower limb amputation. Unfortunately, the bacterial species that cause these infections are becoming more resistant to antibiotics, making them increasingly difficult to treat. We assessed the feasibility of combating chronic bacterial infections with a topically delivered bacteriophage cocktail in two animal models of diabetes mellitus. Microbiological, planimetric, and histological parameters were compared in debrided infected wounds with or without topical bacteriophage treatment. We determined that bacteriophage treatment effectively decreased bacterial colony counts and improved wound healing, as indicated by smaller epithelial and dermal gaps, in Staphylococcus aureus and Pseudomonas aeruginosa infections but was not as effective against Acinetobacter baumannii. Although the improvements were more significant in the rodent model than in the porcine model, our results suggest that topically administered bacteriophage treatment may be effective in resolving chronic infections, especially when applied in conjunction with wound debridement. These findings have important implications for the feasibility of using topical antimicrobial therapies to safely treat chronic infections in diabetes mellitus patients.  相似文献   
69.
70.
This study was designed to investigate the potential neuroprotective effect of exercise in a mouse model of Alzheimer’s disease (AD) induced by intracerebroventricular (i.c.v.) injection of beta-amyloid1–40 (Aβ1–40) peptide. For this aim, male Swiss Albino mice were submitted to swimming training (ST) with progressive increase in intensity and duration for 8 weeks before Aβ1–40 administration (400 pmol/animal; 3 μl/site, i.c.v. route). The cognitive behavioral, oxidative stress, and neuroinflammatory markers in hippocampus and prefrontal cortex of mice were assessed 7 days after Aβ1–40 administration. Our results demonstrated that ST was effective in preventing impairment in short- and long-term memories in the object recognition test. ST attenuated the increased levels of reactive species and decreased non-protein thiol levels in hippocampus and prefrontal cortex induced by Aβ1–40. Also, Aβ1–40 inhibited superoxide dismutase activity and increased glutathione peroxidase, glutathione reductase, and glutathione S-transferase activities in hippocampus and prefrontal cortex—alterations that were mitigated by ST. In addition, ST was effective against the increase of tumor necrosis factor-alpha and interleukin-1 beta levels and the decrease of interleukin-10 levels in hippocampus and prefrontal cortex. This study confirmed the hypothesis that exercise is able to protect against some mechanisms of Aβ1–40-induced neurotoxicity. In conclusion, we suggest that exercise can prevent the cognitive decline, oxidative stress, and neuroinflammation induced by Aβ1–40 in mice supporting the hypothesis that exercise can be used as a non-pharmacological tool to reduce the symptoms of AD.  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