Numerical aspects for efficient welding computational mechanics

The effect of the residual stresses and strains is one of the most important parameter in the structure integrity assessment. A finite element model is constructed in order to simulate the multi passes mismatched submerged arc welding SAW which used in the welded tensile test specimen. Sequentially coupled thermal mechanical analysis is done by using ABAQUS software for calculating the residual stresses and distortion due to welding. In this work, three main issues were studied in order to reduce the time consuming during welding simulation which is the major problem in the computational welding mechanics (CWM). The first issue is dimensionality of the problem. Both two- and three-dimensional models are constructed for the same analysis type, shell element for two dimension simulation shows good performance comparing with brick element. The conventional method to calculate residual stress is by using implicit scheme that because of the welding and cooling time is relatively high. In this work, the author shows that it could use the explicit scheme with the mass scaling technique, and time consuming during the analysis will be reduced very efficiently. By using this new technique, it will be possible to simulate relatively large three dimensional structures

Different aspects of emotional processes in apathy: Application of the French translated dimensional apathy scale

Apathy is a behavioural symptom that occurs in neuropsychiatric, neurological and neurodegenerative disease. It is defined as a lack of motivation and/or a quantitative reduction of goal-directed behaviour. Levy and Dubois Cerebral Cortex, 16(7), 916–928 (2006) proposed a triadic substructure of apathy and similar subtypes can be assessed using the Dimensional Apathy Scale (DAS), via the Executive, Emotional and Initiation subscales. The aim of this study was to translate the DAS in to French (f-DAS), examine its psychometric properties and the substructure of apathy using Confirmatory Factor Analysis (CFA). The results showed an acceptable internal consistency reliability of the f-DAS and a similar relationship to depression as in the original DAS development study. The CFA supported a triadic dimensional substructure of the f-DAS, similar to the original DAS but suggested a more complex substructure, specifically, two further processes of the Emotional apathy dimension relating to “Social Emotional” and “Individual Emotional” aspects of demotivation. To conclude, the f-DAS is a robust and reliable tool for assessing multidimensional apathy. Further research should explore the utility of the f-DAS in patients with neuropsychiatric diseases in view of social emotional aspects in apathy

Роль фактора некроза опухоли-альфа в прогнозировании тяжести и исхода сепсиса у пациентов неотложного отделения с системным воспалением

Aim of the study was to determine whether the TNF-a levels, proximal inflammatory mediator, in septic patients presenting to the emergency department (ED) and admitted to the intensive care unit (ICU) are associated with progression to severe sepsis, septic shock or death. Material and methods. A retrospective observational study was performed on a sample of one hundred adult subjects presenting to the ED with systemic inflammatory response syndrome of 2 etiologies: presumed (and later confirmed in the ICU and/or operating room) severe acute pancreatitis or generalized peritonitis. Blood TNF-a samples measurements were taken shortly after ED admission. TNF-a was measured by commercial ELISA test in plasma. Results. Mean values of TNF-a on admission (day zero, in ED) were 191,5-fold lower in group with septic shock compared to severe sepsis group and were 63-fold higher in survivors (p<0.01). The area under the curve (AUC) for the TNF-a plots for severity of clinical status was 0.813 and for outcome 0.834. Patients with TNF-a levels lower than 7.95 pg/mL had a 3.2-fold higher probability of septic shock development than those with higher values, at the cutoff level sensitivity was 83,9% and specificity 72,5%. Patients with TNF-a levels higher than 10.5 pg/mL had a 4.8-fold higher probability to survive than those with lower values, at the cutoff level sensitivity was 83,0% and specificity 77,4%. Conclusion: Decreasing in TNF-a concentration leads to the septic shock development and fatal outcome. TNF-a is very good predictor of sepsis severity and outcome. Key words: sepsis, tumor necrosis factor-alpha, emergency medical services, survival rate, severity of illness index.Цель исследования — определить, связаны ли уровни ФНО-a, ключевого медиатора воспаления, у пациентов с сепсисом, поступающих в отделение неотложной помощи и переводящихся в отделение реанимации, с прогрессированием его до тяжелого сепсиса, септического шока и смерти. Материал и методы. Ретроспективное обсервационное исследование было выполнено на выборке в 100 взрослых человек, поступивших в неотложное отделение с признаками системного воспаления двух возможных этиологий: тяжелый острый панкреатит (предполагаемый, а затем подтвержденный в отделении реанимации и/или операционной) или общий перитонит. Производили измерения ФНО-a в крови сразу после поступления. ФНО-a измеряли коммерчески доступным ELISA-методом в плазме крови. Результаты. Средние уровни ФНО-a при поступлении (день 0, в неотложном отделении) были в 191,5 раз ниже в группе с септическим шоком по сравнению с группой тяжелого сепсиса и в 63 раза выше у выживших (

Biological pollutants in indoor air

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Cross-sectional associations between personality traits and device-based measures of step count and sedentary behaviour in older age: the Lothian Birth Cohort 1936

Background: While the associations between personality traits and self-reported physical activity are well replicated, few studies have examined the associations between personality and device-based measures of both physical activity and sedentary behaviour. Low levels of physical activity and high levels of sedentary behaviour are known risk factors for poorer health outcomes in older age. Methods: We used device-based measures of physical activity and sedentary behaviour recorded over 7 days in 271 79-year-old participants of the Lothian Birth Cohort 1936. Linear regression models were used to assess whether personality traits were cross-sectionally associated with step count, sedentary time, and the number of sit-to-stand transitions. Personality traits were entered one at a time, and all-together, controlling for age and sex in Model 1 and additionally for BMI and limiting long-term illness in Model 2. Results: None of the associations between personality traits and measures of physical activity and sedentary behaviours remained significant after controlling for multiple-comparisons using the False Discovery Rate test (all ps &gt;.07). Conclusions: We found no evidence that personality traits are associated with device-based measures of physical activity or sedentary behaviour in older age. More studies are needed to replicate and examine the nature of these relationships.</p

Sleep and brain morphological changes in the eighth decade of life

Objective: Sleep is important for brain health. We analysed associations between usual sleep habits and MRI markers of neurodegeneration (brain atrophy), vascular damage (white matter hyperintensities, WMH) and waste clearance (perivascular spaces, PVS) in older community-dwelling adults. Method: We collected self-reported usual sleep duration, quality and medical histories from the Lothian Birth Cohort 1936 (LBC1936) age 76 years and performed brain MRI. We calculated sleep efficiency, measured WMH and brain volumes, quantified PVS, and assessed associations between sleep measures and brain markers in multivariate models adjusted for demographic and medical history variables. Results: In 457 subjects (53% males, mean age 76±0.65 years), we found: brain and white matter loss with increased weekend daytime sleep (β=-0.114, P=0.03; β=-0.122, P=0.007 respectively), white matter loss with less efficient sleep (β=0.132, P=0.011) and PVS increased with interrupted sleep (OR 1.84 95% CI, P=0.025). Conclusion: Cross-sectional associations of sleep parameters with brain atrophy and more PVS suggest adverse relationships between usual sleep habits and brain health in older people that should be evaluated longitudinally

Structural and functional papez circuit integrity in amyotrophic lateral sclerosis

Cognitive impairment in amyotrophic lateral sclerosis (ALS) is heterogeneous but now recognized as a feature in non-demented patients and no longer exclusively attributed to executive dysfunction. However, despite common reports of temporal lobe changes and memory deficits in ALS, episodic memory has been less explored. In the current study, we examined how the Papez circuit—a circuit known to participate in memory processes—is structurally and functionally affected in ALS patients (n = 20) compared with healthy controls (n = 15), and whether these changes correlated with a commonly used clinical measure of episodic memory. Our multimodal MRI approach (cortical volume, voxel-based morphometry, diffusion tensor imaging and resting state functional magnetic resonance) showed reduced gray matter in left hippocampus, left entorhinal cortex and right posterior cingulate as well as increased white matter fractional anisotropy and decreased mean diffusivity in the left cingulum bundle (hippocampal part) of ALS patients compared with controls. Interestingly, thalamus, mammillary bodies and fornix were preserved. Finally, we report a decreased functional connectivity in ALS patients in bilateral hippocampus, bilateral anterior and posterior parahippocampal gyrus and posterior cingulate. The results revealed that ALS patients showed statistically significant structural changes, but more important, widespread prominent functional connectivity abnormalities across the regions comprising the Papez circuit. The decreased functional connectivity found in the Papez network may suggest these changes could be used to assess risk or assist early detection or development of memory symptoms in ALS patients even before structural changes are established