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   262篇
  免费   23篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   5篇
妇产科学   1篇
基础医学   33篇
口腔科学   2篇
临床医学   24篇
内科学   69篇
皮肤病学   5篇
神经病学   29篇
特种医学   5篇
外科学   23篇
综合类   4篇
一般理论   1篇
预防医学   56篇
眼科学   1篇
药学   20篇
肿瘤学   7篇
  2023年   4篇
  2022年   4篇
  2021年   13篇
  2020年   6篇
  2019年   8篇
  2018年   9篇
  2017年   5篇
  2016年   8篇
  2015年   4篇
  2014年   15篇
  2013年   14篇
  2012年   23篇
  2011年   24篇
  2010年   7篇
  2009年   5篇
  2008年   9篇
  2007年   8篇
  2006年   19篇
  2005年   16篇
  2004年   17篇
  2003年   10篇
  2002年   14篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1996年   4篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   6篇
  1991年   2篇
  1990年   4篇
  1986年   1篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1974年   2篇
  1973年   1篇
  1970年   1篇
  1969年   1篇
  1967年   1篇
  1966年   1篇
  1964年   1篇
  1963年   3篇
排序方式: 共有286条查询结果,搜索用时 31 毫秒
51.
52.
What capacity do chronically mentally ill adults have for envisioning personal development as evidenced by the ability to set therapeutic goals? This study explored how individual differences in ego development (Loevinger, 1976) predict the therapeutic goal-setting capacities of adults with chronic mental illness receiving therapy in a community mental health setting. The sample included 51 men and 49 women, ages 25 to 65, diagnosed with schizophrenia, schizoaffective disorder, or bipolar disorder. Utilizing correlational and multiple regression analyses, results confirmed a relationship between higher stages of ego development and greater complexity of therapeutic goals, as well as greater commitment to therapeutic goals. Rehabilitation goals were more prevalent at lower stages of ego development, while goals such as enhancing one's personal relationships, and gaining increased insight emerged at higher stages. Implications for therapeutic change are discussed.  相似文献   
53.
54.
55.
Several international organizations have recently highlighted endocrine-disrupting chemicals (EDCs) as factors of concern in human reproduction. Since successful reproduction is dependent on timely and appropriate action of hormones, disruption of the endocrine system could lead to difficulties in conceiving or carrying a pregnancy to term. EDCs are chemicals that disrupt the endocrine system by activating or inhibiting receptors of the endocrine system, and/or altering hormone receptor expression; signal transduction; epigenetic marks; hormone synthesis, transport, distribution, and metabolism; and the fate of hormone-producing cells. Due to the increasing production of industrial chemicals over the past century and their lenient control, EDCs are now common contaminants in the environment. Consequently, everyone faces a life-long exposure to mixtures of chemicals, some of which have been identified as EDCs. As birth rates in humans are declining and the use of assisted reproductive technologies increasing, it is timely to consider possible effects of EDCs on human reproduction and fertility. In this review, we focus on persistent EDCs, their occurrence in ovarian follicular fluid, and associations to treatment outcomes in assisted reproduction. Our summary shows that despite being banned decades ago, mixtures of persistent EDCs are still detected in the ovarian follicular fluid, demonstrating direct exposure of oocytes to these chemicals. In addition, there are several reported associations between exposure and worse outcome in in vitro fertilization. Further research is therefore warranted to prove causality, which will lead towards better regulation and exposure reduction.  相似文献   
56.
Relatively few coronavirus disease cases and deaths have been reported from sub-Saharan Africa, although the extent of its spread remains unclear. During August 10–September 11, 2020, we recruited 2,214 participants for a representative household-based cross-sectional serosurvey in Juba, South Sudan. We found 22.3% of participants had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain IgG titers above prepandemic levels. After accounting for waning antibody levels, age, and sex, we estimated that 38.3% (95% credible interval 31.8%–46.5%) of the population had been infected with SARS-CoV-2. At this rate, for each PCR–confirmed SARS-CoV-2 infection reported by the Ministry of Health, 103 (95% credible interval 86–126) infections would have been unreported, meaning SARS-CoV-2 has likely spread extensively within Juba. We also found differences in background reactivity in Juba compared with Boston, Massachusetts, USA, where the immunoassay was validated. Our findings underscore the need to validate serologic tests in sub-Saharan Africa populations.  相似文献   
57.
SettingAs of June 10, 2020, 37 people experiencing homelessness or unstable housing in Calgary, Alberta, had developed lab-confirmed COVID-19. Spread occurred despite standard outbreak controls at affected shelter and supportive housing sites. Among these 37 cases, drink sharing was frequently identified as a modifiable mode of possible transmission. We collaborated with emergency shelters, a supportive housing site, and street and encampment outreach groups, using mixed service delivery by health staff, non-profits, and peers with lived experience with homelessness.InterventionTo empower individuals to decrease COVID-19 transmission using a harm reduction approach, we provided disposable paper cups to service providers for distribution to clients. Service providers tracked the number of cups distributed. To assess effectiveness, we interviewed staff and peers who distributed the cups.OutcomesCup distribution was highest among populations with higher rates of alcohol use, and the intervention was well received by people who drink alcohol regularly, providing unique opportunities to promote COVID-19 awareness and safer drinking practices. Providers to these populations reported enthusiastic client engagement and repeat requests for cups for safer drinking. Intervention usefulness was limited in contexts with low alcohol consumption and in the absence of paired COVID-19 education. Provider reports suggest appropriate disposal of these cups after use.ImplicationsDisposable cups are a novel, rapidly implementable, low-cost harm reduction tool to empower people experiencing homelessness to reduce the risk of COVID-19 transmission due to drink sharing, ideally as part of a larger harm reduction and community education strategy.  相似文献   
58.
Anal manometry, rectal capacity measurement, and the saline-infusion test were performed in 350 patients, 178 of whom had fecal incontinence and 172 of whom were continent. Anal manometry was also performed in 80 control subjects, whose results were compared with the patients. Women and older patients exhibited lower pressures. Compared with continent patients, incontinent patients had lower anal sphincter pressures at rest and during squeeze, a smaller rectal capacity, and leaked earlier and more with the saline infusion test. Differentiation between incontinent and continent patients was not possible with a single test because there was complete overlap. The maximum squeeze pressure showed the best discrimination. Combining the three tests did not show better discrimination than any individual test. Anal pressure and rectal capacity below the normal range only were found in very few incontinent patients. The authors' study demonstrates that no prediction can be made about continence with anorectal function tests. Therefore, in the individual patient, an abnormal result in one test must be interpreted with caution and only in relationship with other tests, especially when therapeutic surgery is considered.  相似文献   
59.
Tip cells, the leading cells of angiogenic sprouts, were identified in cultures of human umbilical vein endothelial cells (HUVECs) by using CD34 as a marker. Here, we show that tip cells are also present in primary human microvascular endothelial cells (hMVECs), a more relevant endothelial cell type for angiogenesis. By means of flow cytometry, immunocytochemistry, and qPCR, it is shown that endothelial cell cultures contain a dynamic population of CD34+ cells with many hallmarks of tip cells, including filopodia-like extensions, elevated mRNA levels of known tip cell genes, and responsiveness to stimulation with VEGF and inhibition by DLL4. Furthermore, we demonstrate that our in vitro tip cell model can be exploited to investigate cellular and molecular mechanisms in tip cells and to discover novel targets for anti-angiogenesis therapy in patients. Small interfering RNA (siRNA) was used to knockdown gene expression of the known tip cell genes angiopoietin 2 (ANGPT2) and tyrosine kinase with immunoglobulin-like and EGF-like domains 1 (TIE1), which resulted in similar effects on tip cells and sprouting as compared to inhibition of tip cells in vivo. Finally, we identified two novel tip cell-specific genes in CD34+ tip cells in vitro: insulin-like growth factor 2 (IGF2) and IGF-1-receptor (IGF1R). Knockdown of these genes resulted in a significant decrease in the fraction of tip cells and in the extent of sprouting in vitro and in vivo. In conclusion, this study shows that by using our in vitro tip cell model, two novel essential tip cells genes are identified.  相似文献   
60.
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