Positively Worded Subscale Score of the Perceived Stress Scale Is Associated with Cognitive Domain Function

Objectives: To examine the cross-sectional associations of the separate subscales of the Perceived Stress Scale (PSS) and tests measuring cognitive domains in older adults. Methods: 897 adults over the age of 70 free of amnestic mild cognitive impairment and dementia and enrolled in the Einstein Aging Study made up the study sample. The PSS-14 was used to measure stress. Three cognitive domains (language, episodic memory, and frontal-executive) had previously been found using principle component analysis. Linear regression analyses were used to determine the relationship between the PSS subscales and cognitive domain function. Results: The study sample had a mean age of 79.1 years and 62.8% were female. Bivariate correlations show that the PSS-14 positively worded subscale of the PSS (PSS-PW) was significantly associated with all three cognitive domains (language: r = -0.15, p < 0.001;episodic memory: r = -0.16, p < 0.001;frontal-executive: r = -0.21, p <0.001) while the negatively worded subscale of the PSS (PSS-NW) was not significantly associated with any cognitive domain. In linear regression analyses adjusted for age, white race, gender, years of education, and depressive symptoms, the PSS-PW remained significantly associated with each of the cognitive domains. The PSS-NW was not associated with any cognitive domains in any model. The PSS-14 was significantly associated with language and episodic memory, but not the frontal-executive domain. Conclusion: Worse PSS-PW scores are associated with reduced cognitive function in the executive, memory, and language domains in nondemented older adults. The PSS-PW subscale correlated better with cognitive function than the overall PSS-14. Future research should evaluate the temporality of the association and if stress reduction therapies improve cognitive performance.

Scaling study of the combustion performance of gas gas rocket injectors

To obtain the key subelements that may influence the scaling of gas-as injector combustor performance, the combustion performance subelements in a liquid propellant rocket engine combustor are initially analysed based on the results of a previous study on the scaling of a gas gas combustion fiowfield. Analysis indicates that inner wall friction loss and heat-flux loss are two key issues in gaining the scaling criterion of the combustion performance. The similarity conditions of the inner wall friction loss and heat-flux loss in a gas-gas combustion chamber are obtained by theoretical analyses. Then the theoretical scaling criterion was obtained for the combustion performance, but it proved to be impractical. The criterion conditions, the wall friction and the heat flux are further analysed in detail to obtain the specific engineering scaling criterion of the combustion performance. The results indicate that when the inner fiowfields in the combustors are similar, the combustor wall shear stress will have similar distributions qualitatively and will be directly proportional to pc0.8dt-0.2 quantitatively. In addition, the combustion peformance will remain unchanged. Furthermore, multi-element injector chambers with different geometric sizes and at different pressures are numerically simulated and the wall shear stress and combustion efficiencies are solved and compared with each other. A multi- element injector chamber is designed and hot-fire tested at several chamber pressures and the combustion performances are measured in a total of nine hot-fire tests. The numerical and experimental results verified the similarities among combustor wall shear stress and combustion performances at different chamber pressures and geometries, with the criterion applied.

Health-related quality of life in Parkinson's disease patients in northeastern Sicily, Italy An ecological perspective

Parkinson＇s disease has a negative impact on health-related quality of life in Parkinson＇s disease patients. Depression, cognitive impairment, coping strategies, dyskinesia, gait disorders and complications of dopaminergic drugs are the variables that most affect health-related quality of life. The ecological model of human development focuses attention on both individual and social environmental factors as targets for health interventions. From this perspective, the aim of this cross-sectional survey was to evaluate the influence of gender, family size and perceived autonomy on health-related quality of life in Parkinson＇s disease patients in nOrtheastern Sicily, Italy. Ninety Parkinson＇s disease patients, attending the Movement Disorders Clinic at IRCCS Centro Neurolesi ＂Bonino-Pulejo＂ （Messina）, were consecutively enrolled. The Unified Parkinson Disease Rating Scale motor subscale （UPDRS-Ⅲ） scores, the Parkinson Disease Questionnaire-39 Item scores （as a disease-specific measure of health-related quality of life）, scores on the Short Form （36） Health Survey Questionnaire （as a generic measure）, and answers to a brief checklist were recorded. A total of 85 Parkinson＇s disease patients （49% males and 51% females; mean age 70.8 ± 8.6 years mean UPDRS-Ⅲ 24.15 ± 6.55; mean disease duration 5.52 ± 4.65 years） completed the booklet of questionnaires. In the multivariate regression analysis, we included clinical and social variables as independent predictors of health-related quality of life. Our results suggest a potential compounding effect of ecological intrapersonal and interpersonal levels on health-related quality of life outcomes. Gender, self-evaluated autonomy and family size significantly impacted health-related quality of life. If quality of life is used as an indicator of treatment outcomes, an ecological perspective of the case history will be important to disclose relevant prognostic information and trigger personalized health care interventions.

Anxiety and pre-symptomatic testing for neurodegenerative disorders

In this retrospective study we have investigated the anxiety as an impact of pre-symptomatic testing (PST) for 3 autosomal dominant late-onset diseases: Huntington disease (HD), Machado-Joseph disease (MJD)?and familial amyloidotic polyneuropathy (FAP)?V30MTTR. The study included 686 subjects: 586 (85.4%) were the offspring at risk for FAP, 92 (13.4%) for HD and 8 (1.2%) to MJD. Of these, 352 received the carrier result and 305 the non-carrier result. As indicator of anxiety distress was taken the Self-Rating Anxiety Scale of Zung (SAS), applied in the pre-test and the three post-test moments: three weeks, 6 months and one year after notification of test results. Values decreased significantly along the four evaluation moments, regardless the studied disease or test result. For female population, SAS means cores revealed results of clinical anxiety at pre-test, only decreasing to non clinical scores a year after PST disclosure.

Predictive testing for two neurodegenerative disorders(FAP and HD):A psychological point of view

In this retrospective study, we have researched the psychological impact of pre-symptomatic testing (PST) for 2 autosomal dominant late-onset diseases: Huntington disease (HD and familial amyloidotic polyneuropathy (FAP) V30M TTR. The study included 53 subjects: 40 (75.5%) were the offspring at risk for FAP and 13 (24.5%) for HD. Of these, 38 (73.1%) received the carrier result and 12 (23.1%) the noncarrier result;3 of them did not want to know the result. The indicators taken for emotional distress were the subscales and global indexes of psychopathological Behavior Symptoms Inventory (BSI), applied in the pre-test and post-test, one-year after notification of results. Values decreased significantly one year after the implementation of the PST, regardless of the studied disease or test result;this seems to corroborate previous studies showing that testing does not increase pre-symptomatic levels of emotional disturbance in individuals. However, the subjects studied showed, for all subscales and global indexes of the BSI, significantly higher values than those of control groups.

High flowrate injector with gaseous hydrogen and gaseous oxygen

In order to get a high flowrate gas-gas injector and its design methodology, the combustion flow field of a typical shear-coaxial injector was analyzed firstly. The dimensional analysis was applied in the phenomenon of gas-gas combustion, and design parameter optimization and a structure improvement were also carded out. A high flowrate single-element injector with high 1-12/O2 momentum ratio and tapered 02 post tip was obtained and validated by both numerical and experimental studies. This high flowrate injector has simple construction and it can effectively enhance the mixing, decrease the combustion completion length and also has a benign heat environment. Furthermore, based on the study of the single-element injector, numerical optimization and validation experiments were conducted successively on a multi-element injector equipped with high flowrate injection elements. The multi-element injector with the high flowrate elements started up and shut down smoothly, and operated steadily without any stability aids. In the combustor designed with nominal parameters, this injection element can obtain high combustion efficiency with a flowrate of 3.7 times that of SSME main injector element and shows a benign chamber wall heat compatibility. This injector design and the design methodology can become a reference for the design of other types of injectors for liquid rocket engines.