Biomarkers for Cancer Cachexia: A Mini Review

Cancer cachexia is a common condition in many cancer patients, particularly those with advanced disease. Cancer cachexia patients are generally less tolerant to chemotherapies and radiotherapies, largely limiting their treatment options. While the search for treatments of this condition are ongoing, standards for the efficacy of treatments have yet to be developed. Current diagnostic criteria for cancer cachexia are primarily based on loss of body mass and muscle function. However, these criteria are rather limiting, and in time, when weight loss is noticeable, it may be too late for treatment. Consequently, biomarkers for cancer cachexia would be valuable adjuncts to current diagnostic criteria, and for assessing potential treatments. Using high throughput methods such as “omics approaches”, a plethora of potential biomarkers have been identified. This article reviews and summarizes current studies of biomarkers for cancer cachexia.     

Structural/Reactivity Studies (II): Reactions of Lignin Model Compounds with Pulping Additives

Abstract

Lignin model compounds, capable of forming quinonemethides and having different substituents on the quinonemethide (A) rings and β-aryl ether (B) rings, have been degraded under a variety of conditions in the presence of NaOH (soda), NaOH/Na₂S (kraft), NaOH/glucose, and NaOH/AHQ (soda/AQ). Substituent changes on ring B had no effect on the extent of model fragmentation in the presence of excess AHQ and NaSH. Substituent changes on ring A had large effects on fragmentation under soda/AQ and kraft conditions. These substituent-reactivity relationships indicate that the slow step in the mechanism for model fragmentation under soda/AQ and kraft conditions is quinonemethide formation. Conditions aimed at demonstrating the existence of electron-transfer fragmentation of the model compounds gave results which were inconclusive, but demonstrated that equilibrium reactions between quinonemethide intermediates exist.     

A Model Compound Study: The Formation of Colored Metallic Extractive Complexes and Their Effect on the Brightness of Tmp Pulp

Abstract

Flavonoids, such as Quercetin, are the main polyphenol compounds found in extractives. When complexing with transition metal ions, these extractives may induce a significant discoloration to mechanical pulps. In this study, the effect of metallic extractive complexes was investigated using a model compound, Quercetin. It was confirmed that the complexes formed between some metal ions and Quercetin are strongly colored. However, most of the strong absorbance in visible light due to metallic Quercetin complexes, can be eliminated by the addition of diethylenetriaminepentaacetic acid (DTPA). The metal ions studied were Fe(III), Cu(II), Mn(II) and AI(III).     

Sorption of Cd(II), Co(II), and Zn(II) Complexes with MGDA on Anion Exchange Resins: A Study of the Influence of Various Parameters

The strongly basic polystyrene gel resins Amberjet 4200, Amberjet 4600, and the macroporous strongly basic polystyrene Purolite A 520E were investigated for their sorption properties towards Cd(II), Co(II), and Zn(II) complexes with MGDA. The object of the study was the sorption behavior of three metal ions on the above-mentioned anion exchangers, depending on the metal ions’ concentration, pH, contact time, and temperature. MGDA is an alternative, environmentally friendly complexing agent. The sorption data were fitted to the Langmuir and Freundlich models. Three different kinetic behaviors: pseudo first order, pseudo second order, and intraparticle diffusion were tested. The variations of thermodynamic functions were also calculated.     

Reactivity of Intermediates in the Photochemistry of Copper(II) Macrocyclic Complexes

The reactivity of unstable copper macrocycles which act as intermediates in photochemical transformations of copper(II) complexes with synthetic macrocyclic ligands has been reviewed. Although most of these species were investigated by flash photolysis, a number of pulse radiolytic investigations of related species were also incorporated in this review.     

滑动轴承结构参数对其油膜承载力的影响

滑动轴承作为石油化工旋转机械中的重要部件,对于旋转机械运行稳定性具有十分重要的影响。文章基于流体润滑的雷诺方程,对不同几何结构参数下的滑动轴承内部油膜压力分布和承载力进行了研究与分析。研究结果表明,大长径比和大偏心情况均会产生较大的油膜压力和承载力,而油膜承载力作用角的变化趋势与长径比无关,它随着偏心率的增大而先增后减。     

工艺参数对ATO复合涂料抗静电性能的影响

研究了主要工艺参数对ATO抗静电涂料导电性能的影响,用渗滤模型分析了导电填料含量对涂层导电性能的影响;填料表面处理实验表明,偶联剂能提高ATO的最大填充量。另外,讨论了基体树脂种类、固化工艺对涂层导电性能的影响,并确定了优化的工艺参数。     

轮胎胶料热物性参数对温度场的影响研究

研究轮胎胶料热物性参数对温度场的影响。结果表明:橡胶材料的热物性参数对轮胎温度场影响显著,胎圈处的软三角胶、纤维包布和型胶及耐磨胶的热扩散系数和导热系数对最高温度和温度偏差均有较大影响;胎肩部位胎面胶的导热系数对最高温度影响最大,胎肩垫胶的热扩散系数对温度偏差的影响最大。依据分析结果对胎圈和胎肩部位胶料的热物性参数进行优化设计,为胶料配方改善提供了参考。     

Supramolecular Assembly on Coordination of Azopolymer Complexes: A Review

This review gives an account of the coordination chemistry of supramolecular azopolymer complexes. The syntheses and structures of azomonomers and their azopolymer complexes were described. Spectral techniques such as (IR, ¹H-NMR, ESR) and thermal analysis were investigated. Supramolecular architectures assembled were exhibited through weak interaction including hydrogen bonding and π–π stacking. The spectral data indicate geometry of azopolymer complexes and the orbital reduction factors. ESR spectral data provided information about their structures on the basis of Hamiltonian parameters and degree of covalency. All the azopolymer complexes are ESR active due to the presence of an unpaired electron. The force constant F_U–O(mdyn/Å) and the bond length R_U–O (Å) of the U–O bond were calculated from the IR data and related to the electronic properties of the substituents. Wilson's method, the matrix method, Badger's formula, and the Jones and El-Sonbati equations were used to calculate the U–O bond distances from the values of the stretching and interaction force constants. The most probable correlations between U–O force constant to U–O bond distance were satisfactorily discussed in terms of Badger's rule, and the Jones and El-Sonbati equations. The thermal stability was investigated using thermogravimetric analysis. The results showed that the azopolymer complexes are mostly more stable than the homopolymer. The stability of the proton ligand/metal ligand constants in the monomeric and polymeric forms was studied carefully using potentiometery. Based on the thermodynamic functions, the dissociation process is nonspontaneous, endothermic and entropically unfavorable. The metal complexes that were formed exhibited spontaneous, endothermic and entropically favorable behavior.     

V型密封圈结构参数对密封性能影响研究

利用ANSYS对高压柱塞泵V型密封圈进行有限元仿真分析,并搭建实验装置对模拟结果进行了验证。在此基础上,研究了内、外过盈量、唇口角度对密封面接触压力和密封圈内应力分布的影响。结果表明:过盈量增加,接触压力峰值增大,活塞杆往复过程中带出和带回的液体量都减少,有利于实现密封,但如果过盈量过大,会使密封面峰值压力过大、润滑效果变差从而加速磨损。唇口角度增加,活塞杆内行程带回的液体量增加,可以减少泄漏,有利于实现密封。研究结果可为V型密封圈的设计、选用和结构优化提供依据和参考。     

基于不同理论的C-S-H凝胶模型及结构参数表征研究进展

硅酸钙凝胶(C-S-H凝胶)是硅酸盐水泥主要水化产物,也是硬化水泥石强度重要来源。本文系统阐释了基于不同理论所得出的C-S-H凝胶结构模型,包括泰勒模型(Taylor模型)、固溶模型、瑞迟德森-格夫斯模型(R-G模型)、纳米结构模型(CM模型)、固相-液相-凝胶体系模型(SLGS模型)、三维介观结构模型,重点介绍了SLGS模型和三维介观结构模模型。并结合现有的研究进展对C-S-H凝胶的钙硅摩尔比、含水量、聚合度、硬度等的结构参数及其表征方法进行了介绍。     

FTire轮胎模型参数对整车平顺性的影响分析

通过FTire软件对轮胎模型参数进行辨识和研究,得到轮胎模型参数与轮胎性能以及整车平顺性的关系。结果表明：有10个参数对整车平顺性有一定的影响;对整车平顺性影响较大的轮胎力学性能有轮胎垂向刚度、轮胎纵向刚度、轮胎带束层质量和轮胎轴向阻尼比。     

New Platinum(II) Triazole Thiosemicarbazone Complexes: Analysis of Their Reactivity and Potential Antitumoral Action

The synthesis and characterization of three new platinum complexes, with 3,5-diacetyl-1,2,4-triazole bis(4-N-isopropylthiosemicarbazone) as a ligand, are reported. The specific conditions under which solvent coordination takes place are reported and the X-ray structure of the complex with one solvent molecule of dimethyl sulfoxide is resolved. Analysis of the reactivity of these platinum compounds aids in finding the best solution profile for biological investigations. Then, the interactions of the complexes with biological models, such as calf-thymus DNA, are studied by using UV spectroscopy and tracking the changes in electrophoretic mobility produced in the supercoiled plasmid DNA model. Initial screening of these potential antitumoral compounds indicates possible selective antitumoral action.     

结构参数对注塑齿轮翘曲变形量影响的研究

通过对齿轮结构参数的分析,采用UG和Moldflow相结合的方法对不同的齿轮模型进行建模,以收缩不均引起的最大翘曲变形量为目标参数,对结构参数与目标参数之间的关系进行研究。用Origin得到模数、加强筋个数、倒角大小与目标参数之间的关系曲线。分析表明,模数相同时,目标参数值随着加强筋个数的增加逐渐减小;模数不同时,目标参数值随着模数的增大而增大。并对所得数据用MATLAB进行拟合,得到了相应的数学模型,为注塑齿轮相关的设计提供一定的参考。     

A Structural Perspective on the RNA Editing of Plant Respiratory Complexes

The last steps of respiration, a core energy-harvesting process, are carried out by a chain of multi-subunit complexes in the inner mitochondrial membrane. Several essential subunits of the respiratory complexes are RNA-edited in plants, frequently leading to changes in the encoded amino acids. While the impact of RNA editing is clear at the sequence and phenotypic levels, the underlying biochemical explanations for these effects have remained obscure. Here, we used the structures of plant respiratory complex I, complex III₂ and complex IV to analyze the impact of the amino acid changes of RNA editing in terms of their location and biochemical features. Through specific examples, we demonstrate how the structural information can explain the phenotypes of RNA-editing mutants. This work shows how the structural perspective can bridge the gap between sequence and phenotype and provides a framework for the continued analysis of RNA-editing mutants in plant mitochondria and, by extension, in chloroplasts.     

New Iron(II) Complexes for Atom‐Transfer Radical Polymerization: The Ligand Design for Triazacyclononane Results in High Reactivity and Catalyst Performance

Mononuclear cordinatively unsaturated iron(II) complexes having a triazacyclononane ligand were developed as highly efficient and environmentally friendly catalysts for the atom‐transfer radical polymerization (ATRP). These iron catalysts showed high performance in the well‐controlled ATRP of styrene, methacrylates, and acrylates. The high reactivity of these catalysts led to well‐controlled polymerization and block copolymerization even with lower catalyst concentrations.     

The Role of RASGRP2 in Vascular Endothelial Cells—A Mini Review

RAS guanyl nucleotide-releasing proteins (RASGRPs) are important proteins that act as guanine nucleotide exchange factors, which activate small GTPases and function as molecular switches for intracellular signals. The RASGRP family is composed of RASGRP1–4 proteins and activates the small GTPases, RAS and RAP. Among them, RASGRP2 has different characteristics from other RASGRPs in that it targets small GTPases and its localizations are different. Many studies related to RASGRP2 have been reported in cells of the blood cell lineage. Furthermore, RASGRP2 has also been reported to be associated with Huntington’s disease, tumors, and rheumatoid arthritis. In addition, we also recently reported RASGRP2 expression in vascular endothelial cells, and clarified the involvement of xenopus Rasgrp2 in the vasculogenesis process and multiple signaling pathways of RASGRP2 in human vascular endothelial cells with stable expression of RASGRP2. Therefore, this article outlines the existing knowledge of RASGRP2 and focuses on its expression and role in vascular endothelial cells, and suggests that RASGRP2 functions as a protective factor for maintaining healthy blood vessels.     

换能器结构参数对聚合物超声塑化黏弹生热的影响

为研究超声换能器结构参数对聚合物超声塑化过程黏弹性生热的影响,首先确定超声黏弹性生热系统的组成,进行纵振超声换能器结构设计;然后分析超声黏弹性生热过程及超声黏弹性生热原理;最后采用单一变量法分析超声换能器的主要结构参数对其纵振频率及工具头前端质点最大振幅的影响,将其实际输出的纵振激励加载于熔融聚合物,研究其结构参数对聚合物超声黏弹性生热过程及达到聚合物玻璃化转变温度所用时间的影响。结果表明,随纵振激励作用时间的增加,聚合物温度非线性升高;放大比对聚合物温度变化影响最大,前盖板厚度和工具头长度次之,影响最小的是变幅杆长度。