Assessment of fiber arrangement and contiguity in composite materials by image analysis

The overall objective of this research was to correlate the processing—fiber arrangement—properties relationships of composites. In order to do this, an experimental technique to quantitatively characterize the fiber arrangement was developed. Using this technique, the compression molded graphite/epoxy composites, CMC, were found to have a standard deviation of fiber spacing of about twice the value of those from the simulated random composites, SRC. The standard deviation of fiber volume fraction for CMC was about 4 times the value of SRC. In other words, the fibers in this laboratory CMC were poorly distributed relative to SRC.     

Microstructural and Mechanical Characteristics of Porous Irons Produced with Small Particle Size Corn Starch

Powder Metallurgy and Metal Ceramics - The space holder technique was widely used in manufacturing high melting-point porous metals. Corn powders with a smaller size (11.4 μm on average) than...     

Therapeutic Effects of Insulin-Producing Human Umbilical Cord-Derived Mesenchymal Stem Cells in a Type 1 Diabetes Mouse Model

In patients with type 1 diabetes (T1D), compromised pancreatic β-cell functions are compensated through daily insulin injections or the transplantation of pancreatic tissue or islet cells. However, both approaches are associated with specific challenges. The transplantation of mesenchymal stem cells (MSCs) represents a potential alternative, as MSCs have tissue-forming capacity and can be isolated from various tissues. The human umbilical cord (hUC) is a good source of freely available MSCs, which can be collected through pain-free, non-invasive methods subject to minimal ethical concerns. We sought to develop a method for the in vitro generation of insulin-producing cells (IPCs) using MSCs. We examined the potential therapeutic uses and efficacy of IPCs generated from hUC-derived MSCs (hUC-IPCs) and human adipose tissue (hAD)-derived MSCs (hAD-IPCs) through in vitro experiments and streptozotocin (STZ)-induced C57BL/6 T1D mouse models. We discovered that compared to hAD-IPCs, hUC-IPCs exhibited a superior insulin secretion capacity. Therefore, hUC-IPCs were selected as candidates for T1D cell therapy in mice. Fasting glucose and intraperitoneal glucose tolerance test levels were lower in hUC-IPC-transplanted mice than in T1D control mice and hAD-IPC-transplanted mice. Our findings support the potential use of MSCs for the treatment of T1D.     

Characterization of Inhibitory Capability on Hyperpolarization-Activated Cation Current Caused by Lutein (β,ε-Carotene-3,3′-Diol), a Dietary Xanthophyll Carotenoid

Lutein (β,ε-carotene-3,3′-diol), a xanthophyll carotenoid, is found in high concentrations in the macula of the human retina. It has been recognized to exert potential effectiveness in antioxidative and anti-inflammatory properties. However, whether and how its modifications on varying types of plasmalemmal ionic currents occur in electrically excitable cells remain incompletely answered. The current hypothesis is that lutein produces any direct adjustments on ionic currents (e.g., hyperpolarization-activated cation current, I_h [or funny current, I_f]). In the present study, GH₃-cell exposure to lutein resulted in a time-, state- and concentration-dependent reduction in I_h amplitude with an IC₅₀ value of 4.1 μM. There was a hyperpolarizing shift along the voltage axis in the steady-state activation curve of I_h in the presence of this compound, despite being void of changes in the gating charge of the curve. Under continued exposure to lutein (3 μM), further addition of oxaliplatin (10 μM) or ivabradine (3 μM) could be effective at either reversing or further decreasing lutein-induced suppression of hyperpolarization-evoked I_h, respectively. The voltage-dependent anti-clockwise hysteresis of I_h responding to long-lasting inverted isosceles-triangular ramp concentration-dependently became diminished by adding this compound. However, the addition of 10 μM lutein caused a mild but significant suppression in the amplitude of erg-mediated or A-type K⁺ currents. Under current-clamp potential recordings, the sag potential evoked by long-lasting hyperpolarizing current stimulus was reduced under cell exposure to lutein. Altogether, findings from the current observations enabled us to reflect that during cell exposure to lutein used at pharmacologically achievable concentrations, lutein-perturbed inhibition of I_h would be an ionic mechanism underlying its changes in membrane excitability.     

Effects of PCSK-9 Inhibition by Alirocumab Treatments on Biliary Cirrhotic Rats

Hyperlipidemia and oxidative stress with elevated oxidized low-density lipoprotein (ox-LDL) exacerbate hepatic inflammation and fibrosis. The plasma level of low-density lipoprotein (LDL) is controlled by proprotein convertase subtilisin/kexin 9 (PCSK9). Alirocumab is a monoclonal antibody that decreases LDL via inhibiting PCSK9 function. Apart from lipid-lowering effects, alirocumab exerts anti-inflammation, anti-angiogenesis and anti-oxidant effects. This study aims to investigate the impact of alirocumab treatment on common bile duct ligation (BDL)-induced biliary cirrhotic rats. After a 4-week treatment of alirocumab, the hemodynamic data, blood biochemistry, ox-LDL level, oxidative stress markers, severity of hepatic encephalopathy and abnormal angiogenesis of BDL rats were measured and compared to the control group. BDL rats presented cirrhotic pictures and elevated ammonia, total cholesterol, LDL and ox-LDL levels compared to the control group. Alirocumab decreased plasma levels of total cholesterol, LDL, and oxidative stress markers; however, it did not affect the hemodynamics, liver and renal biochemistry, and the plasma levels of ammonia and ox-LDL. The motor activities, portal-systemic collaterals and mesenteric vascular density were not significantly different between alirocumab-treated and control groups. In addition, it did not affect hepatic inflammation, intrahepatic angiogenesis, liver fibrosis and free cholesterol accumulation in the liver of BDL rats. In conclusion, PCSK9 inhibition by alirocumab treatment ameliorates hyperlipidemia and systemic oxidative stress in biliary cirrhotic rats. However, it does not affect the plasma level of ox-LDL, intrahepatic inflammation and fibrosis. In addition, PCSK9 inhibition has a neutral effect on abnormal angiogenesis and hepatic encephalopathy in biliary cirrhotic rats.     

New Secondary Constructions of Generalized Bent Functions

Three new secondary constructions of generalized bent functions are presented. We provide a secondary construction of generalized bent functions from indirect s...     

石英晶体微天平的研究进展及应用

介绍了石英晶体微天平的基本原理和结构,重点介绍了仪器研究进展及应用,包括常规石英晶体微天平（QCM）、耗散型石英晶体微天平（QCM-D）、阵列式石英晶体微天平与电化学石英晶体微天平（EQCM）。     

ZSF合金抗钻性及复合韧化效果

研究了ＺＳＦ合金的显微组织及其抗钻削性和冲击韧性。结果表明,ＺＳＦ合金的显微组织是奥氏体＋共晶碳化物。该组织的硬度虽不很高（３５ＨＲＣ）却具有很强的抗钻削能力,其主要机制是钻削时加工硬化引起部分奥氏体转变成马氏体。该合金单体结构冲击韧性较低,与韧性好的Ｑ２３５Ａ钢焊接复合后抗冲击能力可明显提高。     

协同优化方法及铰接式自卸车系统设计协同优化模型

对协同优化方法的基本思想、计算框架、研究现状及发展进行了分析论述,并将协同优化方法引入到铰接式自卸车(ADT)系统设计中,叙述了对铰接式自卸车进行协同优化的必要性,对ADT系统进行分解,建立协同优化模型,并提出协同优化方法的求解思路。