Structural response and mechanical properties of the hind wing of the beetle Protaetia brevitarsis.

The folding/unfolding mechanism and collision recovery effect of the beetle's hind wings can provide biomimetic inspiration for the optimization of wing deplorability and the investigation of collision prevention recovery mechanism of new amphibious morphing vehicle. In this study, a method is described to investigate the structural response and mechanical properties of the hind wings of the beetle Protetia brevitarsis under natural conditions. The specially processed test samples were conducted to tensile testing, which facilitates the evaluation of the mechanical properties of specific areas of the hind wing. The micro geometric morphological characteristics of the cross-section of the specimen after tensile fracture were observed by scanning electron microscopy. The three-dimensional morphology of the ventral and dorsal sides of the hind wing was characterized using three-dimensional scanning and reverse modeling methods. The finite element model of the hind wing is developed to investigate the structural deformation and modal response characteristics of its flapping. The uniformly distributed load on the hind wing surface is derived from the lift characteristics obtained from the computational fluid dynamics simulation of flapping wing motion. RESEARCH HIGHLIGHTS: Scanning electron microscope is used to observe the cross-sectional characteristics of the veins and membranes. The material properties of the wing membranes and veins of the hind wings were measured using the tensile testing system. The three-dimensional morphology of the hind wing was characterized using 3D scanning and reverse modeling methods. The finite element model of the hind wing is developed to investigate the structural deformation and modal response characteristics of its flapping.

Extracting prime protein targets as possible drug candidates: machine learning evaluation.

Extracting "high ranking" or "prime protein targets" (PPTs) as potent MRSA drug candidates from a given set of ligands is a key challenge in efficient molecular docking. This study combines protein-versus-ligand matching molecular docking (MD) data extracted from 10 independent molecular docking (MD) evaluations - ADFR, DOCK, Gemdock, Ledock, Plants, Psovina, Quickvina2, smina, vina, and vinaxb to identify top MRSA drug candidates. Twenty-nine active protein targets (APT) from the enhanced DUD-E repository ( http://DUD-E.decoys.org ) are matched against 1040 ligands using "forward modeling" machine learning for initial "data mining and modeling" (DDM) to extract PPTs and the corresponding high affinity ligands (HALs). K-means clustering (KMC) is then performed on 400 ligands matched against 29 PTs, with each cluster accommodating HALs, and the corresponding PPTs. Performance of KMC is then validated against randomly chosen head, tail, and middle active ligands (ALs). KMC outcomes have been validated against two other clustering methods, namely, Gaussian mixture model (GMM) and density based spatial clustering of applications with noise (DBSCAN). While GMM shows similar results as with KMC, DBSCAN has failed to yield more than one cluster and handle the noise (outliers), thus affirming the choice of KMC or GMM. Databases obtained from ADFR to mine PPTs are then ranked according to the number of the corresponding HAL-PPT combinations (HPC) inside the derived clusters, an approach called "reverse modeling" (RM). From the set of 29 PTs studied, RM predicts high fidelity of 5 PPTs (17%) that bind with 76 out of 400, i.e., 19% ligands leading to a prediction of next-generation MRSA drug candidates: PPT2 (average HPC is 41.1%) is the top choice, followed by PPT14 (average HPC 25.46%), and then PPT15 (average HPC 23.12%). This algorithm can be generically implemented irrespective of pathogenic forms and is particularly effective for sparse data.

Establishment and validation of improved six-year-old pediatric thorax human model / 医用生物力学

Objective To improve the biological fidelity of the thorax flexible body in the original MADYMO child human model,so as to further study pediatric thorax injuries of child occupant.Methods The finite element model of six-year-old pediatric thorax was built by the method of reverse modeling based on CT images.By replacing the thorax model with flexible body in MADYMO six-year-old human model,an improved human model containing biomechanical thorax model was developed.The model was verified by joint validation of two tests,including Irwin and Mertz's method of scaling channel reported in Kroell's adult chest impact experiment and Ouyang's thoracic impact test on pediatric cadavers.Results The response of this established thorax model was in good agreement with scaling channel method and cadaver test data,and the thorax model was much more accurate than the original flexible body model.The resilience of simulation model was consistent with cadaver test.Conclusions The validity of the model is verified,and the results can be further used for occupant injury analysis in vehicle frontal crash.

Establishment and validation of improved six-year-old pediatric thorax human model / 医用生物力学

Objective To improve the biological fidelity of the thorax flexible body in the original MADYMO child human model, so as to further study pediatric thorax injuries of child occupant. Methods A finite element model of the six-year-old pediatric thorax was built by adopting the method of reverse modeling based on CT images. By replacing the thorax model with flexible body in MADYMO six-year-old human model, an improved human model containing biomechanical thorax model was developed. The model was verified by joint validation of two tests, including Kroell’s adult chest impact experiment combined with Irwin and Mertz’s scaling method, and Jun Ouyang’s thoracic impact test on pediatric cadavers. Results The response of this established thorax model was in good agreement with scaling method and cadaver test data, and the thorax model was much more accurate than the original flexible body model. The resilience of simulation model was consistent with cadaver test. Conclusions The validity of the model is verified, and can be further used in occupant injury analysis in vehicle frontal crash.

Establishment and validation of improved six-year-old pediatric thorax human model / 医用生物力学

Objective To improve the biological fidelity of the thorax flexible body in the original MADYMO child human model,so as to further study pediatric thorax injuries of child occupant.Methods The finite element model of six-year-old pediatric thorax was built by the method of reverse modeling based on CT images.By replacing the thorax model with flexible body in MADYMO six-year-old human model,an improved human model containing biomechanical thorax model was developed.The model was verified by joint validation of two tests,including Irwin and Mertz's method of scaling channel reported in Kroell's adult chest impact experiment and Ouyang's thoracic impact test on pediatric cadavers.Results The response of this established thorax model was in good agreement with scaling channel method and cadaver test data,and the thorax model was much more accurate than the original flexible body model.The resilience of simulation model was consistent with cadaver test.Conclusions The validity of the model is verified,and the results can be further used for occupant injury analysis in vehicle frontal crash.

Establishment and validation of improved six-year-old pediatric thorax human model / 医用生物力学

Objective To improve the biological fidelity of the thorax flexible body in the original MADYMO child human model,so as to further study pediatric thorax injuries of child occupant.Methods The finite element model of six-year-old pediatric thorax was built by the method of reverse modeling based on CT images.By replacing the thorax model with flexible body in MADYMO six-year-old human model,an improved human model containing biomechanical thorax model was developed.The model was verified by joint validation of two tests,including Irwin and Mertz's method of scaling channel reported in Kroell's adult chest impact experiment and Ouyang's thoracic impact test on pediatric cadavers.Results The response of this established thorax model was in good agreement with scaling channel method and cadaver test data,and the thorax model was much more accurate than the original flexible body model.The resilience of simulation model was consistent with cadaver test.Conclusions The validity of the model is verified,and the results can be further used for occupant injury analysis in vehicle frontal crash.

One Year Survival in Nigerians with Peripartum Cardiomyopathy.

BACKGROUND: Peripartum cardiomyopathy (PPCM) is common in North-Western Nigeria. This study aimed to describe the 1-year survival and left ventricular reverse remodeling (LVRR) in a group of patients with PPCM from three referral hospitals in Kano, Nigeria. METHODS: PPCM was defined according to recommendations of the Heart Failure (HF) Association of the European Society of Cardiology Working Group on PPCM. LVRR was defined as absolute increase in left ventricular ejection fraction (LVEF) by ≥10.0% and decrease in left ventricular (LV) end-diastolic dimension indexed to body surface area ≤33.0 mm/m(2), while recovered LV systolic function as LVEF ≥55%, at 12 months follow-up. RESULTS: A total of 54 newly diagnosed PPCM patients with mean age of 26.6 ± 6.7 years, presented with classical features of predominantly left-sided HF and 33 of them qualified for follow-up. Of the 17 survivors at 12 months, 8 patients (47.1%) satisfied the criteria for LVRR, of whom 5 (29.4%) had recovered LV systolic function (LVEF ≥55%), but LVRR was not predicted by any variable in the regression models. The prevalence of normal LV diastolic function increased from 11.1% at baseline to 35.3% at 12 months (P = 0.02). At 1-year follow-up, 41.4% of patients had died (two-thirds of them within the first 6 months), but mortality was not predicted by any variable including LVRR. CONCLUSIONS: In Kano, PPCM patients had modest LVRR but high mortality at 1-year. Further studies should be carried out to identify reasons for the high mortality and how to curb it.