Kirchhoff-Love shell representation and analysis using triangle configuration B-splines

This paper presents the application of triangle configuration B-splines (TCB-splines) for representing and analyzing the Kirchhoff-Love shell in the context of isogeometric analysis (IGA). The Kirchhoff-Love shell formulation requires global $C^1$-continuous basis functions. The nonuniform rational B-spline (NURBS)-based IGA has been extensively used for developing Kirchhoff-Love shell elements. However, shells with complex geometries inevitably need multiple patches and trimming techniques, where stitching patches with high continuity is a challenge. On the other hand, due to their unstructured nature, TCB-splines can accommodate general polygonal domains, have local refinement, and are flexible to model complex geometries with $C^1$ continuity, which naturally fit into the Kirchhoff-Love shell formulation with complex geometries. Therefore, we propose to use TCB-splines as basis functions for geometric representation and solution approximation. We apply our method to both linear and nonlinear benchmark shell problems, where the accuracy and robustness are validated. The applicability of the proposed approach to shell analysis is further exemplified by performing geometrically nonlinear Kirchhoff-Love shell simulations of a pipe junction and a front bumper represented by a single patch of TCB-splines

Variational blue noise sampling

Blue noise point sampling is one of the core algorithms in computer graphics. In this paper, we present a new and versatile variational framework for generating point distributions with high-quality blue noise characteristics while precisely adapting to given density functions. Different from previous approaches based on discrete settings of capacity-constrained Voronoi tessellation, we cast the blue noise sampling generation as a variational problem with continuous settings. Based on an accurate evaluation of the gradient of an energy function, an efficient optimization is developed which delivers significantly faster performance than the previous optimization-based methods. Our framework can easily be extended to generating blue noise point samples on manifold surfaces and for multi-class sampling. The optimization formulation also allows us to naturally deal with dynamic domains, such as deformable surfaces, and to yield blue noise samplings with temporal coherence. We present experimental results to validate the efficacy of our variational framework. Finally, we show a variety of applications of the proposed methods, including nonphotorealistic image stippling, color stippling, and blue noise sampling on deformable surfaces. © 1995-2012 IEEE.published_or_final_versio

Integrative transcriptome and proteome revealed high-yielding mechanisms of epsilon-poly-L-lysine by Streptomyces albulus

Introductionε-poly-L-lysine (ε-PL) is a high value, widely used natural antimicrobial peptide additive for foods and cosmetic products that is mainly produced by Streptomyces albulus. In previous work, we developed the high-yield industrial strain S. albulus WG-608 through successive rounds of engineering.MethodsHere, we use integrated physiological, transcriptomic, and proteomics association analysis to resolve the complex mechanisms underlying high ε-PL production by comparing WG-608 with the progenitor strain M-Z18.ResultsOur results show that key genes in the glycolysis, pentose phosphate pathway, glyoxylate pathway, oxidative phosphorylation, and L-lysine biosynthesis pathways are differentially upregulated in WG-608, while genes in the biosynthetic pathways for fatty acids, various branched amino acids, and secondary metabolite by-products are downregulated. This regulatory pattern results in the introduction of more carbon atoms into L-lysine biosynthesis and ε-PL production. In addition, significant changes in the regulation of DNA replication, transcription, and translation, two component systems, and quorum sensing may facilitate the adaptability to environmental pressure and the biosynthesis of ε-PL. Overexpression of ppk gene and addition of polyP6 further enhanced the ε-PL production.DiscussionThis study enables comprehensive understanding of the biosynthetic mechanisms of ε-PL in S. albulus WG-608, while providing some genetic modification and fermentation strategies to further improve the ε-PL production

Metabolomics Reveals Effect of Zishen Jiangtang Pill, a Chinese Herbal Product on High-Fat Diet-Induced Type 2 Diabetes Mellitus in Mice

A Chinese herbal decoction, Zishen Jiangtang Pill (ZJP), has been clinically prescribed to diabetic patients to prevent excessive blood sugar levels for decades. However, the potential mechanisms of this action have not been well investigated. The purpose of this study was to explore the metabolic variations in response to ZJP treatment for an animal model of obese type 2 diabetes. An UHPLC-Orbitrap/MS-based metabolomics tool was conducted to reveal the potential mechanisms of ZJP on diabetic mice. The treatment with ZJP significantly restored the increased levels of insulin, glucose and total cholesterol in high-fat diet mice. A total of 26 potential biomarkers were found and identified in serum samples, amongst which 24 metabolites were robustly affected and driven back to the control-like levels after ZJP treatment. By analyzing the metabolic pathways, glutathione metabolism, steroid hormone biosynthesis and glycerophospholipid metabolism were suggested to be closely involved in diabetes disease. From the above outcomes, it can be concluded that ZJP exhibits a promising anti-diabetic activity, largely due to the regulation of phospholipid metabolism, including phosphatidylcholines, lysophosphatidylcholines, and phosphatidylinositol

Chemical fingerprinting and quantitative analysis of two common Gleditsia sinensis fruits using HPLC-DAD

Gleditsiae Fructus Abnormalis and Gleditsiae Sinensis Fructus are obtained from different developmental stages of fruits from Gleditsia sinensis Lam. (Fam. Leguminosae). The possible interchangeable usage of the two fruits, however, has long been very controversial. Here, high performance liquid chromatography coupled with diode array detection was developed to explore their chemical fingerprinting profiles. Besides, the amounts of aglycons of saponin compounds, echinocystic acid and oleanolic acid in both fruits were quantified. The results indicated that there was no significant difference in the amount of aglycons from the two types of fruits; however, their chromatographic fingerprints showed distinct characteristics. Therefore, the interchangeable application of these fruits has to be taken with a specific precaution

2D quad mesh generation using divide and conquer poly-square maps

We develop a structured quad meshing algorithm for large-scale 2D geometric regions based on solving a low-distorted poly-square map. The poly-square map is constructed through a divide-And-conquer strategy in a distributed way. First, a geometry-Aware partitioning is performed to decompose the geometric region into solvable subparts. Then, parameterizations and meshing are computed on subregions under certain boundary constraints. The local results are merged and refined through a multi-pass optimization until the global convergence of the polysquare map is achieved. We demonstrate that our algorithm can process huge geometric model effectively on high performance clusters