Structure modeling in three-dimensional simulation of weft-knitted seamless kneepads

This paper proposes a simulation method suitable for weft-knitted seamless kneepads. The purpose of this study is to realize the simulation of complete weft-knitted products, and it has the advantage of speed to display the simulation results online in real-time. The loop of the basic loop model is controlled by up to eight characteristic points and the yarn path is fitted by a three-dimensional spline curve. To string the loop model into the fabric, the coordinate of the characteristic point of the loop at other positions is obtained based on the loop model at the origin by using the translation matrix and the rotation matrix. The simulation of the weft-knitted kneepad is realized by the joint programming of Visual Studio and WebGL. The results show that the structure model can achieve the simulation of the kneepad with high efficiency. This method has strong real-time performance and practicability.

Design and analysis of a novel deployable hexagonal prism module for parabolic cylinder antenna

This paper presents a novel deployable hexagonal prism module for parabolic cylinder antennas that exhibit characteristics of geometric scalability. The hexagonal prism module consists of six basic rib mechanisms distributed along the axis and parabolic directions of the parabolic cylinder. The basic rib mechanism along the axis direction is designed, and the position of each member in the deployed state is calculated according to the geometric relationships at the folded state. The basic rib mechanism along the parabolic direction is designed to ensure that the mechanism can be fully folded. The degree of freedom of basic loop mechanisms consisting of four basic rib mechanisms due to the splice of multiple modules is analyzed. The degree of freedom of the proposed hexagonal prism module is verified through simulations and experiments of a deployable mechanism composed of three hexagonal prism modules. The simulation and experiment results show that the proposed hexagonal prism module can offer synchronized and coordinated movement during the deployment process.

The first DEP domain of the RhoGEF P-Rex1 autoinhibits activity and contributes to membrane binding

Phosphatidylinositol (3,4,5)-trisphosphate (PIP3)-dependent Rac exchanger 1 (P-Rex1) catalyzes the exchange of GDP for GTP on Rac GTPases, thereby triggering changes in the actin cytoskeleton and in transcription. Its overexpression is highly correlated with the metastasis of certain cancers. P-Rex1 recruitment to the plasma membrane and its activity are regulated via interactions with heterotrimeric Gβγ subunits, PIP3, and protein kinase A (PKA). Deletion analysis has further shown that domains C-terminal to its catalytic Dbl homology (DH) domain confer autoinhibition. Among these, the first dishevelled, Egl-10, and pleckstrin domain (DEP1) remains to be structurally characterized. DEP1 also harbors the primary PKA phosphorylation site, suggesting that an improved understanding of this region could substantially increase our knowledge of P-Rex1 signaling and open the door to new selective chemotherapeutics. Here we show that the DEP1 domain alone can autoinhibit activity in context of the DH/PH-DEP1 fragment of P-Rex1 and interacts with the DH/PH domains in solution. The 3.1 Å crystal structure of DEP1 features a domain swap, similar to that observed previously in the Dvl2 DEP domain, involving an exposed basic loop that contains the PKA site. Using purified proteins, we show that although DEP1 phosphorylation has no effect on the activity or solution conformation of the DH/PH-DEP1 fragment, it inhibits binding of the DEP1 domain to liposomes containing phosphatidic acid. Thus, we propose that PKA phosphorylation of the DEP1 domain hampers P-Rex1 binding to negatively charged membranes in cells, freeing the DEP1 domain to associate with and inhibit the DH/PH module.

NDM: 1-Bit Delta-Sigma Converter with Non-Linear Loop

In this paper we propose to introduce a new processing scheme in the basic loop of a Delta Sigma (ΔΣ) analog-to-digital converter. This processing confers extra gains of the converter over both the quantization error and the channel noise. This is an advance with respect to all cases found in the literature, where the desired signal is not protected against channel noise. Also, the proposed processing is simple and contrasts with the existing architectures, which produce better quality at the expense of sensitivity to implementation imperfections due to the presence of multiples loops in the corresponding architecture. Furthermore, the in-phase/quadrature components structure of a band pass signal has not been used to improve the performance of ΔΣ converters.

Ion Channel Function and Cross-Species Determinants in Viral Assembly of Nonprimate Hepacivirus p7

ABSTRACTNonprimate hepacivirus (NPHV), the closest homolog of hepatitis C virus (HCV) described to date, has recently been discovered in horses. Even though the two viruses share a similar genomic organization, conservation of the encoded hepaciviral proteins remains undetermined. The HCV p7 protein is localized within endoplasmic reticulum (ER) membranes and is important for the production of infectious particles. In this study, we analyzed the structural and functional features of NPHV p7 in addition to its role during virus assembly. Three-dimensional homology models for NPHV p7 using various nuclear magnetic resonance spectroscopy (NMR) structures were generated, highlighting the conserved residues important for ion channel function. By applying a liposome permeability assay, we observed that NPHV p7 exhibited liposome permeability features similar to those of HCV p7, indicative of similar ion channel activity. Next, we characterized the viral protein using a p7-basedtrans-complementation approach. A similar subcellular localization pattern at the ER membrane was observed, although production of infectious particles was likely hindered by genetic incompatibilities with HCV proteins. To further characterize these cross-species constraints, chimeric viruses were constructed by substituting different regions of HCV p7 with NPHV p7. The N terminus and transmembrane domains were nonexchangeable and therefore constitute a cross-species barrier in hepaciviral assembly. In contrast, the basic loop and the C terminus of NPHV p7 were readily exchangeable, allowing production of infectioustrans-complemented viral particles. In conclusion, comparison of NPHV and HCV p7 revealed structural and functional homology of these proteins, including liposome permeability, and broadly acting determinants that modulate hepaciviral virion assembly and contribute to the host-species barrier were identified.IMPORTANCEThe recent discovery of new relatives of hepatitis C virus (HCV) enables for the first time the study of cross-species determinants shaping hepaciviral pathogenesis. Nonprimate hepacivirus (NPHV) was described to infect horses and represents so far the closest homolog of HCV. Both viruses encode the same viral proteins; however, NPHV protein functions remain poorly understood. In this study, we aimed to dissect NPHV p7 on a structural and functional level. By using various NMR structures of HCV p7 as templates, three-dimensional homology models for NPHV p7 were generated, highlighting conserved residues that are important for ion channel function. A p7-basedtrans-complementation approach and the construction of NPHV/HCV p7 chimeric viruses showed that the N terminus and transmembrane domains were nonexchangeable. In contrast, the basic loop and the C terminus of NPHV p7 were readily exchangeable, allowing production of infectious viral particles. These results identify species-specific constraints as well as exchangeable determinants in hepaciviral assembly.

Valve-Shut off Scheme and Affected Zone Analysis of Multi-Sources Looped-Pipe Network Based on ARCGIS

Based on ArcGIS,Multi-heat sources and multi-loops complex heating network is Modeled and simulated ,and a functional method is put forward, by using Geodatabase data model,it can creat relating matrix and basic loop matrix of heat network quickly,and calculate Hydraulic Regime of heating Network with the Basic Circuit.When pipe-bursting accident occur in heating Network,along with changes in the logical network model.also the entire calculation model is changed.This method is applied to the Study of Valve-shut off scheme after tube-burst accident ,the heating Influence of the accident can be quantitative analyzed , also the degree of influence is compared when tube-burst accident happen at different place.

Kinematics Analysis on Planar Gear Transmission Mechanism with Computer

Kinematics analysis is important to analyse and design planar gear transmission mechanism. Planar gear transmission mechanism is composed of two basic loop units. The kinematics analysis equation of the basic loop units is established based on the constituent characteristics of planar gear transmission mechanism and the motion relationship of every component in each basic loop unit. The kinematics analysis mathematical model of planar gear transmission mechanism is constructed by using the basic loop group units of planar gear transmission mechanism. With Windows XP as the platform, Visual Basic 6.0 as a tool and object-oriented programming method, a set of common software has been developed for kinematics analysis on planar gear transmission mechanism. The software has many advantages, such as simple operation, strong man-machine interaction, friendly interface and strong commonality.