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71.
重离子的细胞杀伤作用大,有倒转剂量分布优势,而且具有拓展布拉格峰、高传能线密度、高相对生物效应等特点。将其应用于癌症治疗,可使深部区域肿瘤细胞因高剂量辐射而被有效杀灭,而对周围组织因低剂量分布、相对危害较小,能实现精确靶向治疗,这也被认为是最有前景的肿瘤放疗技术。本文简要介绍了重离子放射治疗的物理和生物学特征,回顾了重离子放射治疗的发展历程及现状;重点阐述了重离子放射治疗技术在临床的应用现状及优势,以期为重离子辐射生物学的研究人员提供一定的数据参考和未来方向参考,更好地促进重离子放射治疗在临床治癌中的良好应用。  相似文献   
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Purpose

Living in a cold home increases the risk of dying in winter, especially in older people. However, it is unclear which individual factors predict whether older people are living in cold homes.

Methods

Thousand four hundred two men aged 74–95 years from a U.K. population–based study reported difficulties in keeping warm during winter, answering four simple “yes/no” questions. Associations between individual's characteristics and each of the four self-reported measures of cold homes were estimated using logistic regression models. Next, we investigated whether measures of cold homes predict mortality over the subsequent 2.1 years.

Results

Manual social class, difficulties making ends meet, and not being married were each associated (P < .05) with each of the four measures of cold homes (adjusted odds ratios ranged from 1.61 to 4.68). Social isolation, poor respiratory health, and grip strength were also associated with reports of cold homes. Hundred twenty-six men died; those who reported the presence of at least three measures cold homes had increased mortality (adjusted hazard ratios 2.85 [95% confidence interval, 1.11–7.30, P = .029]).

Conclusions

Older people who find it hard to keep warm in winter, and have an elevated mortality, could be identified using a self-report questionnaire.  相似文献   
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Maternal and Child Health Journal - Objective The association between and commonality of risk factors for poor self-rated oral health (SROH) and general health (SRGH) among new mothers has not been...  相似文献   
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The focus on recovery, not just symptom reduction, in mental health care brings a need for psychometrically sound measures of recovery. This study examined the factor structure and sensitivity to change of a common measure of mental health recovery, the Recovery Assessment Scale (RAS). We conducted a secondary data analysis from a randomized clinical trial of self-management for depression (n = 302). We tested both bifactor and the previously found five-factor model. Sensitivity to change was examined three ways: (1) between the intervention and control group; (2) across time in the intervention group; and (3) in those whose depression remitted. The previous five-factor model was supported. One subscale, no domination by symptoms, was particularly sensitive to change and showed sensitivity to change whereas the subscale reliance on others did not show change in any of the comparisons. Results suggest that the subscales of the RAS should be examined separately in future studies of recovery.  相似文献   
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Inhalation of ash can be of great concern for affected communities, during and after volcanic eruptions. Governmental and humanitarian agencies recommend and distribute a variety of respiratory protection (RP), most commonly surgical masks. However, there is currently no evidence on how effective such masks are in protecting wearers from volcanic ash. In Part I of this study (Mueller et al., 2018), we assessed the filtration efficiency (FE) of 17 materials from different forms of RP against volcanic ash and a surrogate, low-toxicity dust, Aloxite. Based on those results, we now present the findings from a volunteer simulation study to test the effect of facial fit through assessment of Total Inward Leakage (TIL).Four different disposable RP types that demonstrated very high median FE (≥96% for Aloxite; ≥89% for volcanic ash) were tested without provision of training on fit. These were an industry-certified mask (N95-equiv.); a surgical mask from Japan designed to filter PM2.5; a flat-fold basic mask from Indonesia; and a standard surgical mask from Mexico, which was also tested with an added medical bandage on top, as an additional intervention to improve fit.Ten volunteers (6 female, 4 male) were recruited. Each RP type was worn by volunteers under two different conditions simulating cleaning-up activities during/after volcanic ashfall. Each activity lasted 10?min and two repeats were completed for each RP type per activity. Dust (as PM2.5) concentration inside and outside the mask was measured with two TSI SidePak aerosol monitors (Models AM510 and AM520, TSI, Minnesota, USA) to calculate TIL. A questionnaire was administered after each test to collect perceptions of fit, comfort, protection and breathability.The best-performing RP type, across both activities, was the industry-certified N95-equiv. mask with 9% mean TIL. The standard surgical mask and the basic flat-fold mask both performed worst (35% TIL). With the additional bandage intervention, the surgical mask mean TIL improved to 24%. The PM2.5 surgical mask performed similarly, with 22% TIL. The N95-equiv. mask was perceived to provide the best protection, but was also perceived as being uncomfortable and more difficult to breathe through.This study provides a first objective evidence base for the effectiveness of a selection of RP types typically worn around the world during volcanic crises. The findings will help agencies to make informed decisions on the procurement and distribution of RP in future eruptions.  相似文献   
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