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   200篇
  免费   22篇
耳鼻咽喉   19篇
儿科学   2篇
妇产科学   13篇
基础医学   29篇
口腔科学   2篇
临床医学   10篇
内科学   55篇
皮肤病学   1篇
神经病学   25篇
特种医学   11篇
外科学   15篇
综合类   2篇
一般理论   1篇
预防医学   17篇
眼科学   2篇
药学   9篇
肿瘤学   9篇
  2023年   2篇
  2022年   10篇
  2021年   6篇
  2020年   3篇
  2019年   10篇
  2018年   5篇
  2017年   6篇
  2016年   9篇
  2015年   3篇
  2014年   10篇
  2013年   7篇
  2012年   13篇
  2011年   11篇
  2010年   7篇
  2009年   2篇
  2008年   14篇
  2007年   14篇
  2006年   14篇
  2005年   10篇
  2004年   13篇
  2003年   14篇
  2002年   5篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1997年   1篇
  1996年   2篇
  1994年   3篇
  1993年   1篇
  1992年   8篇
  1991年   2篇
  1990年   4篇
  1989年   1篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1979年   1篇
排序方式: 共有222条查询结果,搜索用时 18 毫秒
1.
Endoscopic frontal sinus surgery is still considered difficult, risky to perform, and likely to result in a high failure rate. We have previously reported on our technique of endoscopic frontal sinus surgery, stressing the importance of identification and preservation of natural outflow tract. Our study of frontal sinus anatomy shows that the mean frontal ostium anterior—posterior and transverse dimensions are 7.22 ± 2.78 mm and 8.92 ± 2.95 mm, respectively; therefore, dissection of obstructive structures in frontal recess leads to a wide opening of frontal sinus outflow. A key surgical landmark in our technique is the superior attachment of the uncinate process. This article provides an update of the surgical anatomy of the frontal recess region and our surgical technique, as well as a discussion of our approach to frontal sinus revision surgery.  相似文献   
2.
3.
4.
Previous studies have shown that people who develop psychopathology such as posttraumatic stress disorder (PTSD) following stress exposure are characterized by reduced hippocampal (HC) volume and impaired HC functional connectivity with the ventromedial prefrontal cortex (vmPFC). Nevertheless, the exact interrelationship between reduced HC volume and HC‐vmPFC connectivity deficits in the context of stress has yet to be established. Furthermore, it is still not clear whether such neural abnormalities are stress induced or precursors for vulnerability. In this study, we combined measurements of MRI, functional MRI (fMRI), and diffusion tensor imaging (DTI) to prospectively study 33 a priori healthy Israeli soldiers both pre‐ and post‐exposure to stress during their military service. Thus, we were able to assess the contributions of structural and functional features of the HC and its connectivity to the onset and progression of maladaptive response to stress (i.e., increased PTSD symptoms post‐exposure). We found that soldiers with decreased HC volume following military service (i.e., post‐exposure) displayed more PTSD‐related symptoms post‐exposure as well as reduced HC‐vmPFC functional and structural connectivity post‐exposure, compared to soldiers with increased HC volume following military service. In contrast, initial smaller HC volume pre‐exposure did not have an effect on any of these factors. Our results therefore suggest that reduction in HC volume and connectivity with the vmPFC together mark a maladaptive response to stressful military service. As stress‐induced HC volume reductions were previously shown to be reversible, these localized biological markers may carry valuable therapeutic potential. Hum Brain Mapp 34:2808–2816, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
5.
6.
Benzophenone-2 (BP-2) is an additive to personal-care products and commercial solutions that protects against the damaging effects of ultraviolet light. BP-2 is an “emerging contaminant of concern” that is often released as a pollutant through municipal and boat/ship wastewater discharges and landfill leachates, as well as through residential septic fields and unmanaged cesspits. Although BP-2 may be a contaminant on coral reefs, its environmental toxicity to reefs is unknown. This poses a potential management issue, since BP-2 is a known endocrine disruptor as well as a weak genotoxicant. We examined the effects of BP-2 on the larval form (planula) of the coral, Stylophora pistillata, as well as its toxicity to in vitro coral cells. BP-2 is a photo-toxicant; adverse effects are exacerbated in the light versus in darkness. Whether in darkness or light, BP-2 induced coral planulae to transform from a motile planktonic state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of BP-2. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the light induced extensive necrosis in both the epidermis and gastrodermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death. The LC50 of BP-2 in the light for an 8 and 24 h exposure was 120 and 165 parts per billion (ppb), respectively. The LC50s for BP-2 in darkness for the same time points were 144 and 548 ppb. Deformity EC20 levels (24 h) were 246 parts per trillion in the light and 9.6 ppb in darkness.  相似文献   
7.
8.
9.

Background

It was previously demonstrated that MMRV vaccine causes a higher rate of febrile convulsions (FC) compared to the MMR vaccine. Additional risk factors for FC include age, familial tendency, day care attendance, viral diseases, complications at birth and developmental delay.

Objective

We evaluated the relative and attributable risk of FC for vaccinees’ age, ethnicity, low birth weight, preterm birth and MMRV vaccination in 10–24 months old children.

Methods

Data on medical history and vaccination were extracted from data warehouses of Clalit Health Services and Israel's Ministry of Health and linked on an individual record level for 90,294 MMR- and 8344 MMRV-vaccinees. A retrospective study design was used to reveal the risk factors associated with FC in study participants.

Results

During the second week after immunization, an elevated relative risk of FC was demonstrated in MMRV-recipients (adjusted RR = 2.16 (95%CI: 1.01; 4.64)). However, the cumulative incidence of FC during the entire 40-day observation period did not differ between the MMR and MMRV vaccinees. The MMRV-specific attributable risk of FC was not statistically significant at any point of observation period and was exceedingly low compared to other risk factors, equaling 5.3 FC cases per 10,000 vaccinees (95%CI: −1.4; 12.2).

Discussion

Our findings demonstrate that MMRV-associated FC in 10–24 months old contributes very marginally to the overall rate of FC in this population.

Conclusion

Given the low number of MMRV-specific FC cases, their transient nature and the benefit of vaccination, the overall benefit-risk of the vaccine can be considered favourable. Nonetheless, the option of separate immunization with MMR + V should be offered to parents, in order to maintain sufficient vaccine uptake in the population.  相似文献   
10.
BACKGROUND: Therapeutic paratracheal neck dissection for patients with papillary carcinoma of the thyroid is standard treatment. Its use as an elective procedure is controversial. METHODS: Thirty-seven patients with papillary carcinoma of the thyroid and evidence of positive adenopathy at levels II-V underwent selective neck dissection and elective/therapeutic paratracheal neck dissection. Results of preoperative ultrasonography of the neck were compared with the dissection specimens. RESULTS: Morbidity of the surgical procedure was minimal (1 permanent hypocalcemia). All specimens showed metastases from papillary thyroid carcinoma: 100% (37/37) in the jugular chain of lymphatics and 83.7% (31/37) in the paratracheal region. The rate of occult (negative physical examination and ultrasonography) metastases in the paratracheal region in the presence of metastases in the ipsilateral jugular chain was 83.3% (20/24). CONCLUSION: The high rate of occult metastases in the paratracheal region and the low rate of surgical morbidity speak in favor of elective paratracheal neck dissection in patients with metastatic papillary carcinoma of the thyroid.  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