Relationships between femoral strength evaluated by nonlinear finite element analysis and BMD,material distribution and geometric morphology

Precisely quantifying the strength of the proximal femur and accurately assessing hip fracture risk would enable those at high risk to be identified so that preventive interventions could be taken.Development of better measures of femoral strength using the clinically

Quantitative Study on Morphological Change Characteristics of Tonle Sap Lake Based on DEM

Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline development. In most existing studies, remote sensing images are used to quantify the morphological characteristics of lakes. However, the extraction accuracy of lake water is greatly affected by cloud cover and vegetation cover, and the inversion accuracy of lake elevation data is poor, which cannot accurately describe the response relationship of lake landscape morphology with water level change. Therefore, this paper takes Tonle Sap Lake as the research object, which is the largest natural freshwater lake in Southeast Asia. DEM is constructed based on high-resolution measured topographic data, and morphological indicators such as lake area, lake shoreline length, perimeter area ratio, longest axis length, maximum width, shoreline development index, lake shape complexity, compactness ratio and form ratio are adopted to researching the evolution law of high water overflows and low water outbursts quantitatively, and clarifying the variation characteristics of landscape morphology with water level gradient in Tonle Sap Lake. The research results have important theoretical significance for the scientific utilization of Tonle Sap Lake water resources and the protection of the lake ecosystem.

Comparative Study of 3D-Printed Porous Titanium Alloy with Rod Designs of Three Different Geometric Structures for Orthopaedic Implantation

Porous titanium alloy is currently widely used in clinical treatment of orthopaedic diseases for its lower elastic modulus and ability to integrate with bone tissue.At the micro-level,cells can respond to different geometries,and at the macro-level,the geometric design of implants will also affect the biological function of cells.In this study,three kinds of porous scaffolds with square,triangular and circle rod shapes were designed and 3D printed.This study observed the proliferation and differentiation of MC3T3-E1 cells during surface culture of the three types of scaffolds.It also evaluated the characteristics of the three scaffolds by means of compression tests and scanning electron microscopy to provide a reference for the design of porous titanium alloy implants for clinical applications.The trends of cell proliferation and gene expression between the three types of scaffolds were observed after treatment with two inhibitors.The results show that the square rod porous scaffolds have the best proliferative and osteogenic activities,and these findings may be due to differences in piezo-type mechanosensitive ion channel component 1(Piezo1)and Yes-associated protein(YAP)expression caused by the macro-geometric topography.

Quantitative morphometric analysis of a deep-water channel in the Taranaki Basin, New Zealand

The morphological changes of deep-water channels have an important influence on the distributions of channel sand reservoirs,so it is important to explore the morphological change process of deep-water channel for the exploration and development of deep-water oil and gas.Based on a typical sinuous Quaternary channel(Channel I)in the Taranaki Basin,New Zealand,a variety of seismic interpretation techniques were applied to quantitatively characterize the morphological characteristics of the Channel I,and the relationships between the quantitative parameters and the morphological changes of the Channel I,as well as the controlling factors affecting those morphological changes,were discussed.The results are as follows:(1)in the quantitative analysis,six parameters were selected:the channel depth,width,sinuosity,and aspect ratio(width/depth),the channel swing amplitude(λ)and the channel bend frequency(ω);(2)according to the quantitative morphological parameters of the channel(mainly including three parameters such as channel sinuosity,ωandλ),the Channel I was divided into three types:the low-sinuous channel(LSC),the high-sinuous channel(HSC),the moderate-sinuous channel(MSC).U-shaped channel cross-sections developed in the LSC,V-shaped channel cross-sections developed in the HSC,including inclined-V and symmetric-V cross-sections,and dish-shaped channel cross-sections developed in the MSC;(3)the morphological characteristics of the LSC and MSC were related to their widths and depths,while the morphology of the HSC was greatly affected by the channel width,a change in depth did not affect the HSC morphology;(4)the morphological changes of the Channel I were controlled mainly by the slope gradient,the restricted capacity of the channel and the differential in fluid properties.

Genetic and morphological differences between yellowtail kingfish (Seriola lalandi) from the Bohai Sea, China and the Southern Ocean, Australia

The aquaculture of yellowtail kingfish(Seriola lalandi)has expanded around the globe,including China.Genetic resource of Chinese S.lalandi urgently needs to be assessed for improving production.Here,we collected wild S.lalandi samples from the Bohai Sea,China and evaluated its genetic diversity based on 17,690 nuclear loci.A population from the Southern Ocean,Australia was used for comparison.The analyses showed that the Chinese and Australian S.lalandi formed two completely distinct clusters and there was no genetic introgression from the Australian S.lalandi into the Chinese S.lalandi population.The genetic diversity is slightly lower,but comparable in Chinese versus Australian yellowtail kingfish(Chinese population,expected heterozygosity:0.19,observed heterozygosity:0.19,nucleotide diversity:0.19±0.09;Australian population,expected heterozygosity:0.23,observed heterozygosity:0.22,nucleotide diversity:0.22±0.11).Overall,our results indicated that Chinese S.lalandi could be a potential subject for genetic breeding programs.We also investigated morphological characters and developed molecular markers for population identification.Comparison of meristic characters between the Chinese population and the Australian population revealed that main shape difference were in the number of dorsal spines,dorsal fin rays and the number of upper gill rakers.Geometric morphology based on eight landmarks also revealed significant difference between the two populations including the distance between the tip of snout to origin of pelvic fin and the distance between the tip of snout to origin of pectoral fin.These morphological characters can be used for easy identification of the Chinese S.lalandi.