Psychological distress, fear and coping strategies during the second and third waves of the COVID-19 pandemic in Southern Germany

Background: The COVID-19 pandemic has imposed enormous psychological discomfort and fear across the globe, including Germany. Objectives: To assess the levels of COVID-19 associated psychological distress and fear amongst Southern German population, and to identify their coping strategies. Methods: A cross-sectional survey using an online questionnaire was conducted in healthcare and community settings in the region of Ulm, Southern Germany. Assessment inventories were the Kessler Psychological Distress Scale (K-10), the Brief Resilient Coping Scale (BRCS), and the Fear of COVID-19 Scale (FCV-19S), which were valid and reliable tools. Results: A total of 474 Individuals participated in the study. The mean age was 33.6 years, and 327 (69%) were females. Most participants (n = 381, 80.4%) had high levels of psychological distress, whereas only 5.1% had high levels of fear, and two-thirds of participants showed higher levels of coping. Moderate to very high levels of psychological distress were associated with being female, living alone, distress due to employment changes, experiencing financial impact, having multiple co-morbidities, being a smoker, increased alcohol use over the previous 6 months, contact with COVID-19 cases and healthcare providers for COVID-19-related stress. Individuals who wer

Electrical discharge machining (EDM) of CFRP composites

The thesis details research to evaluate the feasibility of wire electrical discharge machining (WEDM) as an alternative to conventional cutting (milling/routing/slotting) of carbon fibre reinforced plastic (CFRP) composites. A comprehensive literature review of various nonconventional machining processes including laser beam machining, abrasive water jet machining, ultrasonic machining and electrical discharge machining revealed that there was comparatively limited work on WEDM of CFRP. In order to address this gap in knowledge, 3 primary phases of experimental work were undertaken to investigate the influence of operating parameters, electrode material, workpiece fibre orientation and stacking with metallic layers when WEDM of CFRP laminates. Phase 1 trials were aimed at studying the effect of key process parameters (open gap voltage, ignition current as well as pulse on and off times) when WEDM unidirectional CFRP plates (all plies laid up in the same orientation) using a 0.25 mm diameter zinc coated brass wire (Topas plus D). The tests were divided into 2 sub-phases, both utilising a L18 Taguchi fractional factorial experimental design with Phase 1A and 1B involving machining parallel and perpendicular to the fibre direction respectively. The main results revealed that the maximum material removal rate (MRR) achieved was higher when cutting parallel to the fibre direction (2.41 mm$^3$/min) as opposed to the perpendicular orientation (1.94 mm$^3$/min), albeit at the expense of marginally wider (3.33%) kerf widths (Wa) and higher (38.6%) workpiece surface roughness (Sa). Ignition current and pulse off time were statistically significant factors with respect to MRR for both cutting directions in addition to open voltage when machining perpendicular to fibre orientation. Conversely, open voltage was the only major factor affecting roughness. In Phase 2, similar experimental designs were utilised when machining parallel (Phase 2A) and perpendicular (Phase 2B) to the fibre directions, but performed using a dual coated (copper and β phase) steel core wire electrode (commercially named as Compeed). Considerably higher MRR of up to 4.7 mm$^3$/min was observed when operating parallel to the fibres compared to corresponding results in Phase 1, while no appreciable improvement was obtained when cutting in the perpendicular direction (maximum MRR of 1.68 mm$^3$/min). However, a marked increase in both kerf width (up to ~ 367 μm) and surface roughness (up to 26.29 μm Sa) was evident in Phase 2A trials. Despite no signs of major defects on the kerf edges, there was visible evidence of frayed fibres, areas of redeposited resin and matrix/fibre loss on the machined surface. Pulse off time had a significant influence on workpiece roughness and recorded the highest percentage contribution ratio (PCR) of 40.55% according to the analysis of variance (ANOVA). Preliminary trials to evaluate the influence of stacking UD-CFRP laminates between copper plates to improve workpiece conductivity and machining performance was undertaken in Phase 3A using both coated brass and steel cored wires. Surprisingly, a marginally higher MRR of 6.5 mm$^3$/min was obtained when machining with the Topas wire compared to 6.11 mm$^3$/min for the Compeed wire. This was possibly due to lower process stability when employing the Compeed wire as a result of greater resin debris in the spark gap. As wire breakage frequently occurred during the preliminary trials, the maximum values of voltage and pulse on time were reduced while pulse off time was increased in Phase 3B, where a response surface methodology (RSM) experiment was designed to study the effect of wire type, ignition current and pulse off time on MRR and surface roughness. While the Topas wire achieved a somewhat higher MRR of 5.89 mm$^3$/min compared to Compeed (5.35 mm$^3$/min), all of the factors were statistically significant at the 5% level with regard to MRR. In contrast, none of the variable parameters had a major influence on surface roughness. Notwithstanding the increased MRR, machining of the metallic-CFRP stacked configuration induced severe delamination on the top/bottom surfaces and kerf edges with frayed fibres. Results from a multi-objective optimisation analysis for MRR and roughness indicated that a current of 4 A and pulse off time of 8 μs were preferred when using the Topas wire. In Phase 3C, multidirectional CFRP workpieces were machined using both wire electrodes, with MRR values ranging between 7.42 and 14.82 mm$^3$/min and from 5.29 to 13.31 mm$^3$/min for Topas and Compeed wires respectively. Pulse off time was the sole significant factor with a PCR of 67.76%, with a strong correlation observed between MRR, machining variables and their interactions based on a coefficient of determination (R$^2$) of 99.79%. The average kerf width (Wa) and Sa when machining with the Compeed wire was up to ~374 μm and 27.53 μm respectively, but which was marginally lower when using the Topas wire (~347 μm and 24.86 μm). Based on the ANOVA for kerf width (Wa), wire type and its interaction with pulse off time were significant terms, with the model for predicting Wa having a R$^2$ of 99.88%. Although none of the variables were significant with respect to surface roughness, the corresponding model demonstrated a strong correlation between predicated Sa and experimental data with a R$^2$ of 96.24%. Generally, this study proved the feasibility/capability of WEDM in cutting thick CFRP composites in addition to identifying the preferred levels of key process variables and wire electrode types to achieve successful machining. While the stacking configuration of UD-CFRP using copper plates enhanced machining productivity, excessive damage was however observed. Machining parallel to workpiece fibre orientation resulted in higher MRR, Wa and Sa compared to perpendicular orientation, particularly when using the Compeed wire. However, the Topas wire revealed superior performance when machining UD-CFRP/Cu stacks and multidirectional CFRP workpieces

Muscle Sonography in Inclusion Body Myositis: A Systematic Review and Meta-Analysis of 944 Measurements

Inclusion body myositis (IBM) is a slowly progressive muscle weakness of distal and proximal muscles, which is diagnosed by clinical and histopathological criteria. Imaging biomarkers are inconsistently used and do not follow international standardized criteria. We conducted a systematic review and meta-analysis to investigate the diagnostic value of muscle ultrasound (US) in IBM compared to healthy controls. A systematic search of PubMed/MEDLINE, Scopus and Web of Science was performed. Articles reporting the use of muscle ultrasound in IBM, and published in peer-reviewed journals until 11 September 2021, were included in our study. Seven studies were included, with a total of 108 IBM and 171 healthy controls. Echogenicity between IBM and healthy controls, which was assessed by three studies, demonstrated a significant mean difference in the flexor digitorum profundus (FDP) muscle, which had a grey scale value (GSV) of 36.55 (95% CI, 28.65–44.45, p < 0.001), and in the gastrocnemius (GC), which had a GSV of 27.90 (95% CI 16.32–39.48, p < 0.001). Muscle thickness in the FDP showed no significant difference between the groups. The pooled sensitivity and specificity of US in the differentiation between IBM and the controls were 82% and 98%, respectively, and the area under the curve was 0.612. IBM is a rare disease, which is reflected in the low numbers of patients included in each of the studies and thus there was high heterogeneity in the results. Nevertheless, the selected studies conclusively demonstrated significant differences in echogenicity of the FDP and GC in IBM, compared to controls. Further high-quality studies, using standardized operating procedures, are needed to implement muscle ultrasound in the diagnostic criteria

Impact of Parkinsonism comorbid depression on cognitive functions

Abstract Background Parkinson's disease (PD) is a chronic progressive neurodegenerative disabling disease and involves about 1–3% of the worldwide population over the age of 60. A significant prevalence of psychopathological symptoms has been recorded as most patients with PD developed over their disease course neuropsychiatric symptoms such as depression, anxiety, sleep disorders, psychosis, and cognitive and behavioral abnormalities. These non-motor symptoms, which could appear decades before motor ones, become disturbing symptoms during the later phases of the disease. Hence, the current research aims to study depressive symptoms in Parkinson's disease patients. Thirty-six patients with Parkinson’s disease aged from 40 to 65 years (20 males and 16 females) and 36 age and sex-matched controls (19 males and 17 females) were included in the study. Unified Parkinson’s Disease Rating Scale (UPDRS), Hoehn and Yahr scale, Schwab and England’s scale, Mini-Mental State Examination, Cognitive Ability Screening Instrument, and Hamilton Depression Rating Scale were applied to assess depression in both groups. Results Patients were 20 males and 16 females (mean age 52.44 ± 7.45), mean duration of Parkinsonism was 3.88 years. The mean value for Hoehn and Yahr scale was 1.97 ± 1.42, for UPDRS T was 42.41 ± 20.91 and Schwab England's scale was 74.77 ± 17.78. Concerning cognition, MMSE was significantly lower among patients 25.33 ± 3.63, than in the control group and CAS total was significantly lower in patients (16 ± 71.35) than in the control group 9.81 ± 84.62. Conclusion Depressive symptoms are widespread in Parkinson's disease. Depression should be strictly determined and addressed, particularly in patients with more advanced cognitive impairment who are at a higher risk of developing or worsening depression