Intervention effects and related mechanisms of glycyrrhizic acid on zebrafish with Hirschsprung-associated enterocolitis

BACKGROUND The prevention and treatment of Hirschsprung-associated enterocolitis(HAEC)is a serious challenge in pediatric surgery.Exploring the mechanism of HAEC is conducive to the prevention of this disease.AIM To explore the possible mechanism of glycyrrhizic acid(GA)and its therapeutic effect on HAEC.METHODS We developed a model of enteritis induced by trinitrobenzenesulfonic acid(TNBS)in zebrafish,and treated it with different concentrations of GA.We analyzed the effect of GA on the phenotype and inflammation of zebrafish.RESULTS After treatment with TNBS,the area of the intestinal lumen in zebrafish was significantly increased,but the number of goblet cells in the intestinal lumen was significantly reduced,but these did not increase the mortality of zebrafish,indicating that the zebrafish enteritis model was successfully developed.Different concentrations of GA protected zebrafish with enteritis.In particular,high concentrations of GA were important for the prevention and control of HAEC because it significantly reduced the intestinal luminal area,increased the number of goblet cells in the intestinal lumen,and reduced the levels of interleukin(IL)-1βand IL-8.CONCLUSION GA significantly reduced the intestinal luminal area,increased the number of intestinal goblet cells,and decreased IL-1βand IL-8 in zebrafish,and is important for prevention and control of HAEC.

Pathological process of liver sinusoidal endothelial cells in liver diseases

Cirrhosis develops from liver fibrosis and is the severe pathological stage of all chronic liver injury. Cirrhosis caused by hepatitis B virus and hepatitis C virus infection is especially common. Liver fibrosis and cirrhosis involve excess production of extracellular matrix,which is closely related to liver sinusoidal endothelial cells(LSECs). Damaged LSECs can synthesize transforming growth factor-beta and platelet-derived growth factor,which activate hepatic stellate cells and facilitate the synthesis of extracellular matrix. Herein,we highlight the angiogenic cytokines of LSECs related to liver fibrosis and cirrhosis at different stages and focus on the formation and development of liver fibrosis and cirrhosis. Inhibition of LSEC angiogenesis and antiangiogenic therapy are described in detail. Targeting LSECs has high therapeutic potential for liver diseases. Further understanding of the mechanism of action will provide stronger evidence for the development of anti-LSEC drugs and new directions for diagnosis and treatment of liver diseases.

航空发动机压气机转子叶片开裂原因分析

某航空发动机高压压气机转子叶片使用后分解检查时发现叶身裂纹。通过宏观检查、能谱分析、金相检查、锻造模拟试验及原材料工艺复查,对裂纹原因进行了综合分析。结果表明:裂纹性质为疲劳,起源于内部缺陷。缺陷性质为原材料料头未切除干净的氧化物夹杂。氧化物夹杂的存在,严重降低了材料的塑性和强度,导致叶片首先在内部缺陷处开裂。在弯曲应力的作用下,裂纹由缺陷位置向叶片表面扩展,形成宏观裂纹。

Reexploration of Structural Changes in Element Bromine through Pressure-Induced Decomposition of Solid HBr

Simple molecular solids have been an important subject in condensed matter physics,particularly for research of pressure-induced molecular dissociation.We re-explore the structural changes of element bromine through pressure-induced decomposition of solid HBr.The phase changes in HBr are investigated by Raman spectroscopy and synchrotron x-ray diffraction up to 125 GPa at room temperature.By applying pressure,HBr decomposes into solid bromine in the pressure range of 18.7-38 GPa.The solid bromine changes from molecular phase to incommensurate phase at 81 GPa,and finally to monatomic phase at 91 GPa.During the process of pressureinduced molecular dissociation, the intermediate incommensurate phase of element bromine is confirmed for the first time from the x-ray diffraction studies.The decomposition of HBr is irreversible since HBr cannot form again upon pressure decompression.

Advanced hermetic electronic packaging based on lightweight silicon/aluminum composite produced by powder metallurgy technique

Silicon/aluminum(Si/Al)composite is a kind of lightweight electronic packaging material that received a lot of attention in the past 20 years.In this paper,a series of Si/Al composites with lowered coefficient of thermal expansion(CTE)and high thermal conductivity were produced by powder metallurgy(PM).The Si/Al composites are fully dense and have fine Si particles uniquely distributed within pure Al matrix.Three 50%Si/Al composites were designed to have strength in the range of 185-290 MPa to meet different demands,while the other properties keep invariable.Fracture toughness of the composites is measured to be 9-10 MPa·m^(1/2).The composites were machined to 50%Si/Al housings and 27%Si/Al lids.Both the hermeticities of housings before and after laser-beam-welding sealing are determined.The measured leak rate of composites and sealed housings is in magnitude order of 1×10^(-10)and 1×10^(-9)Pa·m^(3)·s^(-1),respectively,suggesting high hermeticity.The good hermeticity is attributed to the full dense materials,good weldability,and extremely low weld porosity.The present Si/Al composites are expected to be extensively used in highly hermetic electronic packages.

Interface microstructure evolution and bonding strength of TC11/c-TiA l bi-materials fabricated by laser powder deposition

Laser powder deposition was applied to fabricate the Ti-6.5Al-3.5Mo-1.5Zr-0.3Si （wt%）/Ti-47Al- 2Cr-2Nb-0.2W-0.15B （at%） bi-material system. The asdeposited TC11 alloy shows a basket-wave-like morphology while the as-deposited y-TiAl alloy consists of fully α2/γ lamellar microstructures. Regarding the thermal mismatch between TC11 and γ-TiAl during processing, the interface microstmcture evolution was concerned. The transformation pathway was illustrated. It is found that the content changes of Al elements and β-stabilizers Mo, Cr, and Nb are responsible for the evolution of microstructures at the interface. The fracture surfaces are located at the y-TiAl side. The bi-material shows a brittle-fracture manner, with the ultimate tensile strength of 560 MPa.