Numerical Study on Interactional Aerodynamics of a Quadcopter in Hover with Overset Mesh in OpenFOAM

Interactional aerodynamics of a quadcopter in hover is numerically investigated in this study. The main objective is to understand major flow structures associated with unsteady airloads on multirotor aircraft. The overset mesh approach is used to resolve flow structures in unsteady simulation using the flow solver OpenFOAM. The current computational study demonstrates that aerodynamic interaction between quadcopter components strongly affects the rotor wake, generating interesting vortical structures. Multiple rotors in close proximity generate $\Omega$-shaped vortical structures merged from rotor-tip vortices. The fuselage of the current quadcopter deflects the wake flow of the four rotors towards the center of the vehicle. Such interactional aerodynamics, i.e., rotor-rotor and rotor-fuselage interaction, varies the inflow condition of a rotor blade during the rotor revolution. Therefore, the quadcopter experiences unsteady airloads per rotor revolution. Our study indicates that a typical quadcopter would experience 8/rev thrust variations, which are a combined outcome from 4/rev thrust variations on the rotor and 2/rev fluctuations on the fuselage. The current understanding of interactional aerodynamics could help to design reliable and efficient multicopter aircraft

Characterization of Saccharomyces cerevisiae protein Ser/Thr phosphatase T1 and comparison to its mammalian homolog PP5

BACKGROUND: Protein Ser/Thr phosphatase 5 (PP5) and its Saccharomyces cerevisiae homolog protein phosphatase T1 (Ppt1p) each contain an N-terminal domain consisting of several tetratricopeptide repeats (TPRs) and a C-terminal catalytic domain that is related to the catalytic subunits of protein phosphatases 1 and 2A, and calcineurin. Analysis of yeast Ppt1p could provide important clues to the function of PP5 and its homologs, however it has not yet been characterized at the biochemical or cellular level. RESULTS: The specific activity of recombinant Ppt1p toward the artificial substrates (32)P-myelin basic protein (MBP) and (32)P-casein was similar to that of PP5. Dephosphorylation of (32)P-MBP, but not (32)P-casein, was stimulated by unsaturated fatty acids and by arachidoyl coenzyme A. Limited proteolysis of Ppt1p removed the TPR domain and abrogated lipid stimulation. The remaining catalytic fragment exhibited a two-fold increase in activity toward (32)P-MBP, but not (32)P-casein. Removal of the C terminus increased Ppt1p activity toward both substrates two fold, but did not prevent further stimulation of activity toward (32)P-MBP by lipid treatment. Ppt1p was localized throughout the cell including the nucleus. Levels of PPT1 mRNA and protein peaked in early log phase growth. CONCLUSIONS: Many characteristics of Ppt1p are similar to those of PP5, including stimulation of phosphatase activity with some substrates by lipids, and peak expression during periods of rapid cell growth. Unlike PP5, however, proteolytic removal of the TPR domain or C-terminal truncation only modestly increased its activity. In addition, C-terminal truncation did not prevent further activation by lipid. This suggests that these regions play only a minor role in controlling its activity compared to PP5. Ppt1p is present in both the nucleus and cytoplasm, indicating that it may function in multiple compartments. The observation that Ppt1p is most highly expressed during early log phase growth suggests that this enzyme is involved in cell growth or its expression is controlled by metabolic or nutritional signals

Disparities in the utilisation of preventive health services by the employment status: an analysis of 2007-2012 South Korean national survey

Objectives This study aims to investigate the differences in the utilisation of preventive health services among standard, nonstandard workers, the self-employed, and unpaid family workers. Methods We used the 4th and 5th Korea National Health and Nutrition Examination Survey, a nationwide survey conducted from the year 2007 to 2012. Economically active workers between the ages of 25 and 64 were grouped into standard, nonstandard, the self-employed, and the unpaid family workers (N = 16,964). Outcome variables are the uptake of preventive health services including influenza vaccination, regular medical check-up, and four types of cancer screenings. We used multivariate logistic models. Results Overall, non-standard workers, the self-employed, and unpaid family workers were less likely to use the preventive health care compared to the standard workers. In particular, the selfemployed were less likely to use all the six services compared to the standard workers and showed the lowest level of uptakes among the four working groups. Moreover, the service uptake of the non-standard workers was lower than that of standard workers in all services; except the colon cancer screening. On the other hand, unpaid family workers showed mixed results. While the uptake of influenza vaccination and regular health screening were lower, participation to the cancer screening was not lower compared to that of standard workers. Conclusion There were gaps in the utilisation of preventive services among workers depending on their employment types. Access to preventive health care services of nonstandard workers, the self-employed, and unpaid family workers should be prioritised

Caroli's Syndrome with Autosomal Recessive Polycystic Kidney Disease in a Two Month Old Infant

Caroli's syndrome is a rare congenital disorder that involves intrahepatic bile duct ectasia and congenital hepatic fibrosis, frequently seen with concomitant autosomal recessive polycystic kidney disease (ARPKD). Literature on infants with ARPKD is rare. Here, we present a case of a two month old boy who was diagnosed with Caroli's syndrome and ARPKD

Antigen-binding Characteristics of Circulating IgG Autoantibodies to Cytokeratin 18 Protein in Patients with Nonallergic Asthma

Cytokeratin 18 (CK18) protein was identified as an airway epithelial cell autoantigen associated with nonallergic asthma. Cleavage of CK18 protein by caspase-3 is a marker of early apoptosis in epithelial cells. It has been shown that the expression of active caspase-3 was increased in bronchial epithelial cells of asthmatic patients, when compared with healthy controls. To investigate the antigen-binding characteristics of IgG autoantibodies to CK18 protein in nonallergic asthma, the bindings of IgG autoantibodies to the fragments of CK18 protein cleaved by caspase-3 were analyzed by Western blot using serum samples from three patients with nonallergic asthma. Recombinant human CK18 protein was treated by caspase-3 and cleaved into N-terminal fragment (1-397 amino acids) and C-terminal fragment (398-430 amino acids). The binding capacity of IgG autoantibodies to N-terminal fragment of CK18 was maintained in one patient and reduced in other two patients. IgG autoantibodies from all three patients did not bind to C-terminal fragment of CK18. In conclusion, IgG autoantibodies to CK18 protein from patients with nonallergic asthma seems to preferentially bind to the whole molecule of CK18 protein and their antigen-binding characteristics were heterogeneous among the patients with nonallergic asthma

Non-thermal atmospheric pressure plasma-conditioned root dentin promotes attraction and attachment of primary human dental pulp stem cells in real-time Ex Vivo

This study investigated if non-thermal atmospheric pressure plasma (NTAPP) treatment of root dentin surfaces promotes human dental pulp stem cell (hDPSCs) adhesion. Freshly extracted human single-rooted teeth (n = 36) were decoronated and cut (first vertically, then horizontally) into root dentin slices (3 mm thick). Primary hDPSCs cultures were seeded onto slices randomly assigned to pretreatment groups (n = 9/group): NaOCl (1.5%), EDTA (17%) then NTAPP (Group I); NaOCl then NTAPP (Group II); NaOCl then EDTA (Group III); and NaOCl alone (Group IV). Cell viability and proliferation were measured using MTT assay with log-linear statistical analysis. Cell attachment and spreading morphologies on dentin slices (n = 3/group) were examined through scanning electron microscopy. Early cell adhesion events and subcellular activities were observed in real time by live-cell imaging through holotomographic microscopy. Cell viability and proliferation were significantly higher on NTAPP-treated dentin (p \u3c 0.05), without interactions with EDTA (p \u3e 0.05). The attachment, spreading, extensions and multiple layers of hDPSCs were heightened on NTAPP-treated dentin. Cell adhesion, spreading, and dentinal tubule penetration were hastened on NTAPP-treated dentin surfaces in real-time, with elevated subcellular activities and intracellular lipid droplet formation. NTAPP-treated root dentin surfaces support enhanced cellular responses, potentially promoting pulp-dentin regeneration