Rotational Stiffness of Timber-to-Timber Connections with Self-Tapping axially loaded Screws

Self-tapping axially loaded screws provide high load-carrying capacity and great stiffness. Due to these advantages, they were preferably applied to realise connections for tension members. While the translational stiffness of those connections can be estimated for engineering purposes sufficiently, knowledge about the rotational stiffness is still low. The investigations reported here show the influence of the inclination and the geometrical arrangement of the self-tapping screws on the rotational stiffness of connections for tension members. A test set-up was therefore developed. It enables that tensile forces and rotation are simultaneously effective and quantitatively independently of each other. The experimental results show that the inclination of the screws and the resulting compressive stress in the shear plane has a major influence on the rotational stiffness and that the stiffness of the screws themselves becomes less effective

Cytotoxic Compounds from Aloe megalacantha

Abdissa Ayana N, Gohlke S, Frese M, Sewald N. Cytotoxic Compounds from Aloe megalacantha. Molecules. 2017;22(7): 1136.Phytochemical investigation of the ethyl acetate extract of the roots of Aloe megalacantha led to the isolation of four new natural products—1,8-dimethoxynepodinol (1), aloesaponarin III (2), 10-O-methylchrysalodin (3) and methyl-26-O-feruloyl-oxyhexacosanate (4)—along with ten known compounds. All purified metabolites were characterized by NMR, mass spectrometric analyses and comparison with literature data. The isolates were evaluated for their cytotoxic activity against a human cervix carcinoma cell line KB-3-1 and some of them exhibited good activity, with aloesaponarin II (IC50 = 0.98 µM) being the most active compound

Altered skeletal muscle (mitochondrial) properties in patients with mitochondrial DNA single deletion myopathy

BACKGROUND: Mitochondrial myopathy severely affects skeletal muscle structure and function resulting in defective oxidative phosphorylation. However, the major pathomechanisms and therewith effective treatment approaches remain elusive. Therefore, the aim of the present study was to investigate disease-related impairments in skeletal muscle properties in patients with mitochondrial myopathy. Accordingly, skeletal muscle biopsies were obtained from six patients with moleculargenetically diagnosed mitochondrial myopathy (one male and five females, 53 ± 9 years) and eight age- and gender-matched healthy controls (two males and six females, 58 ± 14 years) to determine mitochondrial respiratory capacity of complex I-V, mitochondrial volume density and fiber type distribution. RESULTS: Mitochondrial volume density (4.0 ± 0.5 vs. 5.1 ± 0.8 %) as well as respiratory capacity of complex I-V were lower (P < 0.05) in mitochondrial myopathy and associated with a higher (P < 0.001) proportion of type II fibers (65.2 ± 3.6 vs. 44.3 ± 5.9 %). Additionally, mitochondrial volume density and maximal oxidative phosphorylation capacity correlated positively (P < 0.05) to peak oxygen uptake. CONCLUSION: Mitochondrial myopathy leads to impaired mitochondrial quantity and quality and a shift towards a more glycolytic skeletal muscle phenotype

Effects of endurance training on skeletal muscle mitochondrial function in Huntington disease patients

BACKGROUND Mitochondrial dysfunction may represent a pathogenic factor in Huntington disease (HD). Physical exercise leads to enhanced mitochondrial function in healthy participants. However, data on effects of physical exercise on HD skeletal muscle remains scarce. We aimed at investigating adaptations of the skeletal muscle mitochondria to endurance training in HD patients. METHODS Thirteen HD patients and 11 healthy controls completed 26 weeks of endurance training. Before and after the training phase muscle biopsies were obtained from M. vastus lateralis. Mitochondrial respiratory chain complex activities, mitochondrial respiratory capacity, capillarization, and muscle fiber type distribution were determined from muscle samples. RESULTS Citrate synthase activity increased during the training intervention in the whole cohort (P = 0.006). There was no group x time interaction for citrate synthase activity during the training intervention (P = 0.522). Complex III (P = 0.008), Complex V (P = 0.043), and succinate cytochrome c reductase (P = 0.008) activities increased in HD patients and controls by endurance training. An increase in mass-specific mitochondrial respiratory capacity was present in HD patients during the endurance training intervention. Overall capillary-to-fiber ratio increased in HD patients by 8.4% and in healthy controls by 6.4% during the endurance training intervention. CONCLUSIONS Skeletal muscle mitochondria of HD patients are equally responsive to an endurance-training stimulus as in healthy controls. Endurance training is a safe and feasible option to enhance indices of energy metabolism in skeletal muscle of HD patients and may represent a potential therapeutic approach to delay the onset and/or progression of muscular dysfunction. TRIAL REGISTRATION ClinicalTrials.gov NCT01879267 . Registered May 24, 2012

High-load resistance exercise with superimposed vibration and vascular occlusion increases critical power, capillaries and lean mass in endurance-trained men

Purpose: It is a widely accepted premise in the scientific community and by athletes alike, that adding resistance exercise to a regular regimen of endurance training increases endurance performance in endurance-trained men. However, critical power (CP), capillarization, and myofiber size remain unaffected by this addition. Therefore, we tested whether the superimposition of resistance exercise with whole-body vibration and vascular occlusion (vibroX) would improve these variables in endurance-trained males relative to resistance exercise alone. Methods: Twenty-one young, endurance-trained males were randomly assigned either to a vibroX (n=11) or resistance (n=10) training group. Both groups trained in a progressive mode twice a week for 8weeks. Pre and post training, histochemical muscle characteristics, thigh muscle size, endurance and strength parameters were determined. Results: vibroX increased CP (P=0.001), overall capillary-to-fiber ratio (P=0.001) and thigh lean mass (P<0.001), while these parameters were unaffected by resistance training. The gain in CP by vibroX was positively correlated with the gain in capillarization (R 2=0.605, P=0.008), and the gain in thigh lean mass was paralleled by increases in MyHC-1 and MyHC-2 fiber cross-sectional areas and strength. Maximum voluntary torque and the finite work capacity above CP (W′) increased significantly only following resistance training. Conclusions: We achieved a proof of concept by demonstrating that modification of resistance exercise by superimposing side-alternating whole-body vibration and sustained vascular occlusion induced further improvements in CP, capillarization and hypertrophy, all of which were not observed with resistance training alone

Genomic structural variations lead to dysregulation of important coding and non-coding RNA species in dilated cardiomyopathy

The transcriptome needs to be tightly regulated by mechanisms that include transcription factors, enhancers, and repressors as well as non-coding RNAs. Besides this dynamic regulation, a large part of phenotypic variability of eukaryotes is expressed through changes in gene transcription caused by genetic variation. In this study, we evaluate genome-wide structural genomic variants (SVs) and their association with gene expression in the human heart. We detected 3,898 individual SVs affecting all classes of gene transcripts (e.g., mRNA, miRNA, lncRNA) and regulatory genomic regions (e.g., enhancer or TFBS). In a cohort of patients (n = 50) with dilated cardiomyopathy (DCM), 80,635 non-protein-coding elements of the genome are deleted or duplicated by SVs, containing 3,758 long non-coding RNAs and 1,756 protein-coding transcripts. 65.3% of the SV-eQTLs do not harbor a significant SNV-eQTL, and for the regions with both classes of association, we find similar effect sizes. In case of deleted protein-coding exons, we find downregulation of the associated transcripts, duplication events, however, do not show significant changes over all events. In summary, we are first to describe the genomic variability associated with SVs in heart failure due to DCM and dissect their impact on the transcriptome. Overall, SVs explain up to 7.5% of the variation of cardiac gene expression, underlining the importance to study human myocardial gene expression in the context of the individual genome. This has immediate implications for studies on basic mechanisms of cardiac maladaptation, biomarkers, and (gene) therapeutic studies alike

Unburdening dementia a basic social process grounded theory – based on a primary care physician survey from 25 countries

OBJECTIVE: To explore dementia management from a primary care physician perspective.DESIGN: One-page seven-item multiple choice questionnaire; free text space for every item; final narrative question of a dementia case story. Inductive explorative grounded theory analysis. Derived results in cluster analyses. Appropriateness of dementia drugs assessed by tertiary care specialist.SETTING: Twenty-five European General Practice Research Network member countries.SUBJECTS: Four hundred and forty-five key informant primary care physician respondents of which 106 presented 155 case stories.MAIN OUTCOME MEASURES: Processes and typologies of dementia management. Proportion of case stories with drug treatment and treatment according to guidelines.RESULTS: Unburdening dementia - a basic social process - explained physicians' dementia management according to a grounded theory analysis using both qualitative and quantitative data. Unburdening starts with Recognizing the dementia burden by Burden Identification and Burden Assessment followed by Burden Relief. Drugs to relieve the dementia burden were reported for 130 of 155 patients; acetylcholinesterase inhibitors or memantine treatment in 89 of 155 patients - 60% appropriate according to guidelines and 40% outside of guidelines. More Central and Northern primary care physicians were allowed to prescribe, and more were engaged in dementia management than Eastern and Mediterranean physicians according to cluster analyses. Physicians typically identified and assessed the dementia burden and then tried to relieve it, commonly by drug prescriptions, but also by community health and home help services, mentioned in more than half of the case stories.CONCLUSIONS: Primary care physician dementia management was explained by an Unburdening process with the goal to relieve the dementia burden, mainly by drugs often prescribed outside of guideline indications. Implications: Unique data about dementia management by European primary care physicians to inform appropriate stakeholders. Key points Dementia as a syndrome of cognitive and functional decline and behavioural and psychological symptoms causes a tremendous burden on patients, their families, and society. •We found that a basic social process of Unburdening dementia explained dementia management according to case stories and survey comments from primary care physicians in 25 countries. •First, Burden Recognition by Identification and Assessment and then Burden Relief - often by drugs. •Prescribing physicians repeatedly broadened guideline indications for dementia drugs. The more physicians were allowed to prescribe dementia drugs, the more they were responsible for the dementia work-up. Our study provides unique data about dementia management in European primary care for the benefit of national and international stakeholders

Cytotoxic Compounds from Aloe megalacantha

Phytochemical investigation of the ethyl acetate extract of the roots of Aloe megalacantha led to the isolation of four new natural products—1,8-dimethoxynepodinol (1), aloesaponarin III (2), 10-O-methylchrysalodin (3) and methyl-26-O-feruloyl-oxyhexacosanate (4)—along with ten known compounds. All purified metabolites were characterized by NMR, mass spectrometric analyses and comparison with literature data. The isolates were evaluated for their cytotoxic activity against a human cervix carcinoma cell line KB-3-1 and some of them exhibited good activity, with aloesaponarin II (IC50 = 0.98 µM) being the most active compound