The roles and mechanisms of miRNA in HBV-HCC carcinogenesis:Why no therapeutic agents after 30 years?

Hepatitis B-associated hepatocellular carcinoma (HBV-HCC) remains an intractable high-mortality solidtumor cancer that accounted for 42% of global HCC cases in 2019. Despite some developments in systemic therapy,only a small subset of late-stage HCC patients responds positively to recently developed therapeutic innovations.MicroRNAs (miRNAs) act as an ancillary epigenetic system that can regulate genome expression in all cancerpathways including HCC. The molecular mechanisms of miRNA regulation in cancer pathogenesis offered researchersa new approach that was widely hoped would translate into miRNA-based drugs and diagnostics. Thirty years on,miRNA-based diagnostic and therapeutic agents for HCC remain a work-in-progress (WIP) and no current miRNAHCC clinical trial has progressed to Phase 4. The question remains why this is the case after 30 years and what is theway forward. The major findings and contribution of this paper are that it illustrates the complexity of the HBVmiRNA interactome in HBV-HCC in all cellular processes, as well as the ancillary role of miRNA in the epigeneticand immune systems. This is combined with a review of the outcomes and problems of clinical trials, to explain whymiRNA therapeutics and diagnostics have not progressed to approved drugs or serum-based diagnostic tests. The wayforward suggests a radical rethink might be so that involves the incorporation of AI, bioinformatics, andnanotechnology to solve the problem.

Investigation of Surface Damage in Forming of High Strength and Galvanized Steel Sheets

Powdering/exfoliating of coatings and scratching galvanized steels and high strength steels （HSS）, are the main forms of surface damage in the forming of which result in increased die maintenance cost and scrap rate. In this study, a special rectangular box was developed to investigate the behavior and characteristics of surface damage in sheet metal forming （SMF） processes. U-channel forming tests were conducted to study the effect of tool hardness on surface damage in the forming of high strength steels and galvanized steels （hot-dip galvanized and galvannealed steels）. Experimental results indicate that sheet deformation mode influences the severity of surface damage in SMF and surface damage occurs easily at the regions where sheet specimen deforms under the action of compressive stress. Die corner is the position where surface damage initiates. For HSS sheet, surface damage is of major interest due to high forming pressure. The HSS and hot-dip galvanized steels show improved ability of damage-resistance with increased hardness of the forming tool. However, for galvannealed steel it is not the forming tool with the highest hardness value that performs best.

Bonding Mechanism of Bamboo Particleboards Made by Laccase Treatment

Using 1–8 years bamboo as materials,the content of different chemical constituent was tested,and the reactive oxygen species(ROS)free radicals produced from laccase treated bamboo were detected by electron spin-resonance(ESR)spectroscope.The wet-process particleboard was made from laccase-treated bamboo by hot pressing and board mechanical properties including internal bond strength(IB),modulus of rupture(MOR)and thickness swelling(TS)after 2-hours water absorption were tested under different conditions.Results showed that laccase mainly catalyze the bamboo components and improved the bonding strength of laccase-treated boards.By ESR measurement on each single component such as milled bamboo lignin,xylan and pore cotton treated with laccase,it was proved that laccase helped the degradation of bamboo lignin to produce ROS free radicals and could not catalyze the oxidation of cellulose and hemicelluloses.A logarithmic function relationship was found between board mechanical properties and ROS free radical level.It is optimal to using 5-year-old bamboo for high efficient utilization.The laccase treatment improves the activity of bamboo particles participating in self-adhesion reaction.

关于惰性含氟温室气体转化与利用的研究进展

过去的几十年里, 含氟气体因其特殊理化性质, 在人类社会中的应用几乎随处可见, 为人们的生产生活提供了诸多便利的同时, 正悄无声息地引起一系列环境危机. 长期研究表明含氟气体所造成的温室效应远高于其他温室气体, 人们不得不对含氟气体的使用进行重新评估. 为有效实现含氟气体的经济效益最大化及降低环境污染, 科学家们正努力开发含氟温室气体转化利用的新方法. 综述了近20年国内外化学家针对氟利昂、硫酰氟、三氟化氮和六氟化硫等惰性含氟温室气体转化与利用的最新研究成果.

碳化锆陶瓷有机前驱体的热解过程

合成了碳化锆陶瓷有机前驱体,研究了其在热解过程中化学成分和物相组成变化,探讨了从有机高分子向无机陶瓷转化的机理,对碳热还原反应进行了热力学分析。结果表明,前驱体在600℃以下完成了有机结构的断裂、裂解碎片的重排与挥发,600℃以上裂解产物不再具备有机特征;随热解温度升高,无定型碳和单斜相ZrO2逐渐生成,大于1200℃时可检测到立方相ZrC,1400℃时单斜相ZrO2基本消失;1500℃时完成碳热还原反应,在远低于热力学反应温度的条件下生成了高度结晶的纳米尺寸的立方相碳化锆陶瓷。

Frictional response of a novel C/C-ZrB_(2)-ZrC-SiC composite under simulated braking

A novel braking material,C/C-ZrB_(2)-ZrC-SiC carbon fibre-reinforced hybrid ceramic matrix composite,was prepared by chemical vapour infiltration and polymeric precursor infiltration and pyrolysis.Investigation of the microstructure of C/C-ZrB_(2)-ZrC-SiC composite showed the homogenous dispersion of three-phase ceramic as the matrix.The frictional properties of the hybrid C/C-ZrB_(2)-ZrC-SiC ceramic matrix composite were measured by a disk-on-disk type dynamometer under dry and wet conditions to simulate the normal landing state of aircraft brake disk friction pairs.C/C-ZrB_(2)-ZrC-SiC ceramic matrix composite has a higher and more stable friction coefficient under wet condition than under dry condition,indicating that the composite has better performance compared with C/C or C/C-SiC braking materials.

Mechanical,corrosion and magnetic behavior of a CoFeMn_(1.2)NiGa_(0.8) high entropy alloy

In this study,a magnetic high entropy alloy(HEA)of CoFeMn_(1.2)NiGa_(0.8)was designed and prepared by arc melting in order to investigate its mechanical,corrosion and magnetic behavior.The results show that the alloy mainly possesses body-centered cubic(BCC)phase and face-centered cubic(FCC)phase.A high compressive strength of 1450 MPa,a strain of 18.5%and a relatively low yield strength of 303MPa in as-cast condition at room temperature can be achieved in the present alloy.In-situ high-energy X-ray diffraction technique was employed to reveal the deformation mechanism of Co Fe Mn_(1.2)Ni Ga_(0.8)under uniaxial compression and the results show that the competition between BCC phase and FCC phase plays a significant role during the compressive process.The corrosion behavior of Co Fe Mn_(1.2)Ni Ga_(0.8)was investigated in 3.5 wt%Na Cl solution and it turned out that the alloy possessed good corrosion resistance.At last,the magnetic behavior of the Co Fe Mn_(1.2)Ni Ga_(0.8)alloy was studied and it can present a high saturation magnetization of 94.5 emu/g and a coercivity of 26.4 Oe at 4 K.This work indicates that the present Co Fe Mn_(1.2)Ni Ga_(0.8)HEA has promising applications as future magnetic functional materials.

Microstructural evolution of polymer-derived hexagonal boron nitride fibres under high-temperature stretching

High-temperature stretching plays a crucial role in enhancing the performance of fibres,while a quantitative investigation into the impacts of tension and stretching duration on the microstructure and performance of hexagonal boron nitride(h-BN)fibres remains absent.In this study,to elucidate the microstructural evolution of the h-BN fibres under thermal stretching,amorphous BN fibres were heated at 2000℃under tension of 30,50,and 70 N for 1,3,and 5 h in a nitrogen atmosphere.Subsequently,the grain size,pore structure,orientation degree,microscopic morphology,and mechanical properties were analysed at room temperature.The results show that high-temperature stretching enhances the orientation degree of the BN fibres,consequently elevating Young’s modulus.The maximum orientation degree of the BN fibres was 86%,aligning with a corresponding Young’s modulus of 206 GPa.Additionally,high-temperature stretching enlarged the sizes of grains and pores,a fact substantiated by the radial cracking of the fibres upon extending thermal stretching time.Owing to the expanded pore structure of the BN fibres and the inability to form a sufficiently strong“card structure”between shorter microfibre bundles,the tensile strength of the BN fibres did not increase continually,reaching a maximum of 1.0 GPa.Microstructural observations revealed that the BN fibres,composed of highly oriented lamellar h-BN grains,tend to form radial textures under high-tensile thermal stretching and onion-skin textures under prolonged thermal stretching.These findings offer a theoretical foundation for the preparation of high-performance h-BN fibres.

Corrosion Resistance of Ti_3Al/BN Abradable Seal Coating

Ti–Al mixed powder（Ti：Al = 3：1 in atomic ratio） and Ti3 Al intermetallic alloy powder mechanically clad hexagonal BN to fabricate Ti Al/BN and Ti3Al/BN composite powders. The corresponding porous abradable seal coatings（named as TAC-1 and TAC-2, respectively） were deposited using vacuum plasma spray（VPS） technology, and their corrosion behavior was studied via salt spray corrosion and electrochemical tests. Phase compositions and microstructures of these coatings before and after corrosion were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM） facilitated with energy dispersive X-ray spectrometer（EDS）. The results showed that spontaneous passivation of TAC-1 and TAC-2 granted the coatings excellent corrosion resistance than that of commercial Al/BN coating. Additionally, TAC-2 exhibited higher corrosion potential（Ecorr） and breakdown potential（Ebp） but a lower corrosion current density（icorr） than TAC-1. A small quantity of the corrosion product（Al（OH）3and Al O） could be detected on the surface of TAC-1, while no corrosion product appeared in TAC-2. The non-uniform elements distribution in the metal matrix of TAC-1 resulted in localized corrosion and relatively poor corrosion resistance compared to TAC-2.

Wear Behavior of a NiCr/AgVO_3 Self-Lubricating Composite

NiCr/AgVO3 self-lubricating composite was prepared by powder cold-pressed method with the NiCr alloy as the matrix and 10 wt.% additive of AgVO3 as solid lubricant. The AgVO3 additive powder was synthesized by the precipitation method which exhibits a melting point of 460℃. Microstructure, phase composition and thermal properties of the AgVO3 powder, as well as the composite of NiCr/AgVO3 were analyzed using scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and differential scanning calorimeter （DSC）. The friction and wear behavior of the specimens from room temperature （R.T.） to 800℃ was evaluated using a ball-on-disk tribometer and 3D white light interference （WLI）. The results showed that the friction coefficient of this material under atmosphere decreases with temperature increasing from R.T. to 800 ~C. However, the wear rate firstly increases from R.T. to 200℃, almost remains stable from 200℃ to 600℃, and then decreases with further increasing the temperature up to 800 ℃. It is also found that the prepared composite materials show a better frictional behavior than NiCr alloy over the whole range of temperatures, which is mainly attributed to solid lubrication of AgVO3 exhibiting a lamella-slip structure at temperatures below 460℃ and forms liquid-film at elevated temperatures above the melting point.

Preparation of spherical Y_2SiO_5 powders for thermal-spray coating

Yttrium silicate, for its high oxidation resistance, is an important candidate for protective coating for carbon-fiber-reinforced composites at temperatures above 1600 ℃. A novel method, consisting of coprecipitation, spray-drying, heat-treatment and plasma-densification, is developed to prepare Y2SiO5 powders for thermal-spraying. The composition, morphology and flowability of the synthesized Y2SiO5 powders are investigated by XRD, SEM and Hall Flowmeter, respectively. The results show that the synthesized Y2SiO5 powders are nearly spherical with high purity. The apparent density and flowability of the Y2SiO5 powders are 1.87 g/cm^3 and 37 s/50 g, respectively, which lead to a high deposition efficiency of up to 80700 for atmospheric plasma spraying.