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   150篇
  免费   1篇
儿科学   2篇
妇产科学   9篇
基础医学   14篇
临床医学   6篇
内科学   11篇
皮肤病学   1篇
神经病学   9篇
特种医学   23篇
外科学   32篇
综合类   1篇
预防医学   9篇
眼科学   3篇
药学   25篇
肿瘤学   6篇
  2023年   1篇
  2022年   3篇
  2021年   6篇
  2020年   1篇
  2019年   1篇
  2018年   3篇
  2017年   3篇
  2016年   4篇
  2015年   2篇
  2014年   4篇
  2013年   5篇
  2012年   10篇
  2011年   10篇
  2010年   2篇
  2009年   8篇
  2008年   3篇
  2007年   12篇
  2006年   8篇
  2005年   7篇
  2004年   5篇
  2003年   3篇
  2002年   6篇
  2001年   5篇
  2000年   6篇
  1999年   7篇
  1998年   1篇
  1997年   1篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1987年   3篇
  1984年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1974年   4篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
  1969年   2篇
  1965年   1篇
  1905年   1篇
排序方式: 共有151条查询结果,搜索用时 15 毫秒
51.

Differences in size between males and females, called the sexual size dimorphism, are common in insects. These differences may be followed by differences in the duration of development. Accordingly, it is believed that insect sex may be used to increase the accuracy of insect age estimates in forensic entomology. Here, the sex-specific differences in the development of Creophilus maxillosus were studied at seven constant temperatures. We have also created separate developmental models for males and females of C. maxillosus and tested them in a validation study to answer a question whether sex-specific developmental models improve the accuracy of insect age estimates. Results demonstrate that males of C. maxillosus developed significantly longer than females. The sex-specific and general models for the total immature development had the same optimal temperature range and similar developmental threshold but different thermal constant K, which was the largest in the case of the male-specific model and the smallest in the case of the female-specific model. Despite these differences, validation study revealed just minimal and statistically insignificant differences in the accuracy of age estimates using sex-specific and general thermal summation models. This finding indicates that in spite of statistically significant differences in the duration of immature development between females and males of C. maxillosus, there is no increase in the accuracy of insect age estimates while using the sex-specific thermal summation models compared to the general model. Accordingly, this study does not support the use of sex-specific developmental data for the estimation of insect age in forensic entomology.

  相似文献   
52.
Human phthalate exposure is ubiquitous, but little is known regarding predictors of urinary phthalate levels. To explore this, 50 pregnant women aged 18-38 years completed two questionnaires on potential phthalate exposures and provided a first morning void. Urine samples were analyzed for 12 phthalate metabolites. Associations with questionnaire items were evaluated via Wilcoxon tests and t-tests, and r-squared values were calculated in multiple linear regression models. Few measured factors were statistically significantly associated with phthalate levels. Individuals who used nail polish had higher levels of mono-butyl phthalate (P=0.048) than non-users. Mono-benzyl phthalate levels were higher among women who used eye makeup (P=0.034) or used makeup on a regular basis (P=0.004). Women who used cologne or perfume had higher levels of di-(2-ethylhexyl) phthalate metabolites. Household products, home flooring or paneling, and other personal care products were also associated with urinary phthalates. The proportion of variance in metabolite concentrations explained by questionnaire items ranged between 0.31 for mono-ethyl phthalate and 0.42 for mono-n-methyl phthalate. Although personal care product use may be an important predictor of urinary phthalate levels, most of the variability in phthalate exposure was not captured by our relatively comprehensive set of questionnaire items.  相似文献   
53.
In this paper 19 cases of caesarean hysterectomy were analysed with regard to indications, choosing the method of operation, post-surgery procedure and management in cases of surgical complications. In period 1975-1985 in Ist Clinic of Obstetrics and Gynecology in Bytom we had 2,961 sections. Caesarean hysterectomy occurred in 0.07% of normal deliveries and in 0.64% of caesarean sections. The most frequent indication for caesarean section followed hysterectomy was placenta praevia (28%) and the most frequent indication for hysterectomy was atony and coagulopathy (32%). In all cases a total abdominal hysterectomy has been made. Mortality rate was 10.5% and the most frequent complications were lesions of urinary bladder (10.5%). The results obtained have been compared with the data from world literature.  相似文献   
54.
55.
56.
57.
58.
Objective: Postpartum hemorrhage (PPH) is one of the most common causes of mortality in obstetrics worldwide. Accuracy in the estimated blood loss is a priority in determining appropriate treatment. The aim of this study was to evaluate the accuracy of estimating blood loss by obstetrics care providers during simulated training sessions.

Method: A prospective study occurred in 2013 in a maternity ward at a teaching hospital. Simulation training sessions recreated a vaginal delivery in which six different scenarios were presented and proposed to each participant for them to estimate the blood loss (from 350?ml to 2500?ml) while using a collector bag graduated every 100?ml from 0?ml to 1500?ml. The primary endpoint was to determine if participants could accurately evaluate blood loss within a 20% error margin.

Results: About 90.7% of the medical staff participated. Ninety-three to 98% of the participants were accurate in their answer depending on which volume they had to estimate. For the lowest volume (350?ml), there was 11.1% overestimation between the estimated volume of blood loss (EBV) and the real volume of blood loss (RBV). However, there was an 8.8% underestimation found for the highest volume.

Conclusion: The accuracy of the estimated blood loss for the obstetrical medical staff, using the collector bag, is more than 96%.  相似文献   
59.
Imprisonment provides opportunities for the diagnosis and successful treatment of HIV, however, the benefits of antiretroviral therapy are frequently lost following release due to suboptimal access and utilization of health care and services. In response, some have advocated for development of intensive case-management interventions spanning incarceration and release to support treatment adherence and community re-entry for HIV-infected releasees. We conducted a randomized controlled trial of a motivational Strengths Model bridging case management intervention (BCM) beginning approximately 3 months prior to and continuing 6 months after release versus a standard of care prison-administered discharge planning program (SOC) for HIV-infected state prison inmates. The primary outcome variable was self-reported access to post-release medical care. Of the 104 inmates enrolled, 89 had at least 1 post-release study visit. Of these, 65.1% of BCM and 54.4% of SOC assigned participants attended a routine medical appointment within 4 weeks of release (P > 0.3). By week 12 post-release, 88.4% of the BCM arm and 78.3% of the SOC arm had at attended at least one medical appointment (P = 0.2), increasing in both arms at week 24–90.7% with BCM and 89.1% with SOC (P > 0.5). No participant without a routine medical visit by week 24 attended an appointment from weeks 24 to 48. The mean number of clinic visits during the 48 weeks post release was 5.23 (SD = 3.14) for BCM and 4.07 (SD = 3.20) for SOC (P > 0.5). There were no significant differences between arms in social service utilization and re-incarceration rates were also similar. We found that a case management intervention bridging incarceration and release was no more effective than a less intensive pre-release discharge planning program in supporting health and social service utilization for HIV-infected individuals released from prison.  相似文献   
60.
While tendons typically undergo primary tensile loading, the human supraspinatus tendon (SST) experiences substantial amounts of tension, compression, and shear in vivo. As a result, the functional roles of the extracellular matrix components, in particular the proteoglycans (PGs), are likely complex and important. The goal of this study was to determine the PG content in specific regions of the SST that exhibit differing mechanical function. The concentration of aggrecan, biglycan, and decorin was determined in six regions of the human SST using immunochemical techniques. We hypothesized that aggrecan concentrations would be highest in areas where the tendon likely experiences compression; biglycan levels would be highest in regions likely subjected to injury and/or active remodeling such as the anterior regions; decorin concentrations would be highest in regions of greatest tensile stiffness. Our results generally supported these hypotheses and demonstrated that aggrecan and biglycan share regional variability, with increased concentration in the anterior and posterior regions and smaller concentration in the medial regions. Decorin, however, was in high concentration throughout all regions. The data presented in this study represent the first regional measurements of PG in the SST. Together with our previous regional measurements of mechanical properties, these data can be used to evaluate SST structure-function relationships. With knowledge of the differences in specific PG content, their spatial variations in the SST, and their relationships to tendon mechanics, we can begin to associate defects in PG content with specific pathology, which may provide guidance for new therapeutic interventions.  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