HOXA11-AS aggravates microglia-induced neuroinflammation after traumatic brain injury

Long noncoding RNAs(lnc RNAs)participate in many pathophysiological processes after traumatic brain injury by mediating neuroinflammation and apoptosis.Homeobox A11 antisense RNA(HOXA11-AS)is a member of the lnc RNA family that has been reported to participate in many inflammatory reactions;however,its role in traumatic brain injury remains unclear.In this study,we established rat models of traumatic brain injury using a weight-drop hitting device and injected LV-HOXA11-AS into the right lateral ventricle 2 weeks before modeling.The results revealed that overexpression of HOXA11-AS aggravated neurological deficits in traumatic brain injury rats,increased brain edema and apoptosis,promoted the secretion of proinflammatory factors interleukin-1β,interleukin-6,and tumor necrosis factorα,and promoted the activation of astrocytes and microglia.Microglia were treated with 100 ng/m L lipopolysaccharide for 24 hours to establish in vitro cell models,and then transfected with pc DNA-HOXA11-AS,mi R-124-3 p mimic,or sh-MDK.The results revealed that HOXA11-AS inhibited mi R-124-3 p expression and boosted MDK expression and TLR4-nuclear factor-κB pathway activation.Furthermore,lipopolysaccharide enhanced potent microglia-induced inflammatory responses in astrocytes.Forced overexpression of mi R-124-3 p or downregulating MDK repressed microglial activation and the inflammatory response of astrocytes.However,the mi R-124-3 p-mediated anti-inflammatory effects were reversed by HOXA11-AS.These findings suggest that HOXA11-AS can aggravate neuroinflammation after traumatic brain injury by modulating the mi R-124-3 p-MDK axis.This study was approved by the Animal Protection and Use Committee of Southwest Medical University(approval No.SMU-2019-042)on February 4,2019.

Evaluating the thermal environment of urban land surfaces in Yakutsk,a city located in a region of continuous permafrost

Rapid urbanization has led to changes in the urban land surface thermal environment.However,there are still much unknown about the urban land surface thermal conditions in permafrost regions.Permafrost is a unique geological environment,changes in the urban land surface thermal environment may trigger geological disasters caused by permafrost degradation.This study utilized remote sensing data and geographic de-tectors to identify the dynamic changes in land surface temperature(LST)and land use/land cover(LU/LC)in Yakutsk,as well as the potential factors contributing to LST variations.Between 1992 and 2020,the built-up area in Yakutsk increased by 36%,and the annual average LST in Yakutsk has risen by 6.67℃,accompanied by an expansion of high-temperature areas.Despite ongoing greening efforts,rapid urbanization poses a threat to these green spaces.Changes in the normalized difference built-up index(NDBI)and land use transfer(LDT)were identified as the primary drivers of urban LST changes.By integrating geographic detector technology and artificial neural network models,we optimized the selection of input factors in the prediction model and used it to explore the future changes in LST in Yakutsk.The average LST in Yakutsk is expected to reach 23.4℃ and 25.1℃ in 2030 and 2040,respectively,with a further increase in high-temperature areas.This study provides a reference for ecological,hydrological,and geological assessments of cities in permafrost regions.

Mechanical properties and microstructure of Mg-treated and Catreated industrial H13 steel after quenching and tempering

The effect of magnesium treatment and calcium treatment on the microstructure and mechanical properties of industrial H13 steel after quenching and tempering was investigated.The impact toughness and tensile tests were mainly carried out,and the microstructure was observed by scanning electron microscopy,electron backscattered diffraction,and X-ray diffraction.The results show that magnesium treatment is still feasible in industrial trials.It is mainly manifested in the refinement of lath martensite and carbides.Compared with calcium treatment,the prior austenite grains and carbides size of industrial H13 steel treated with magnesium decreased by 3.17μm after quenching.After quenching and tempering,the carbides(especially V-rich carbides)in Mg treatment obviously spheroidized and distributed uniformly and increased in quantity significantly.The lath martensite size is reduced from 2.45 to 2.31μm.This suggests that magnesium treatment was able to yield smaller grains and more evenly distributed carbides.Moreover,the impact toughness,yield strength,and ultimate tensile strength of industrial H13 steel with magnesium treatment increased by 28%,65.5 MPa and 123.7 MPa,respectively.The increment of strength mainly comes from dislocation strengthening,grain refinement strengthening,and precipitation strengthening,among which precipitation strengthening accounts for the largest proportion.

Physical and numerical investigation on fluid flow and inclusion removal behavior in a single-strand tundish

Aiming at the problem that the existence of inclusions in the tundish continuous casting process can easily lead to quality defects of the slab,the stainless steel continuous casting tundish was taken as the research object.The effects of flow control device,inclusion density and inclusion size on the mixing characteristics of molten steel and inclusion behavior in tundish were studied.The results showed that compared with the tundish without flow control device,the average residence time of molten steel was prolonged by about 49 s,the dead zone volume fraction was reduced by 8.93%,and the piston fluid integral rate was increased by 12.68%.In the turbulence inhibitor(TI)tundish with weir-dam combination,the removal rate of inclusions with a density of 2700 kg m^(-3) and a particle size of 5 lm is 63.32%,while the removal rate of large inclusions with a density of 150μm could reach 89.04%.When the inclusion particle size was 10-50μm and the density was 2700-4500 kg m^(-3),the effect of inclusion density on inclusion removal rate was small.At the same time,when weir-dam combination TI tundish was set,the inclusions were mainly limited to the slag-metal interface of the first and second chambers of the tundish.The removal rate of inclusions in the first chamber was generally improved,with 10μm inclusions accounting for 47.67% and 150μm inclusions accounting for 60.69%.Furthermore,it has the best effect on the removal of small-size inclusions,especially those less than 70μm.

Efficient and genotype independent maize transformation using pollen transfected by DNA-coated magnetic nanoparticles

Current gene delivery methods for maize are limited to specific genotypes and depend on timeconsuming and labor-intensive tissue culture techniques.Here,we report a new method to transfect maize that is culture-free and genotype independent.To enhance efficiency of DNA entry and maintain high pollen viability of 32%-55%,transfection was performed at cool temperature using pollen pretreated to open the germination aperture(40%–55%).Magnetic nanoparticles(MNPs)coated with DNA encoding either red fluorescent protein(RFP),β-glucuronidase gene(GUS),enhanced green fluorescent protein(EGFP)or bialaphos resistance(bar)was delivered into pollen grains,and female florets of maize inbred lines were pollinated.Red fluorescence was detected in 22%transfected pollen grains,and GUS stained 55%embryos at 18 d after pollination.Green fluorescence was detected in both silk filaments and immature kernels.The T1 generation of six inbred lines showed considerable EGFP or GUS transcripts(29%–74%)quantitated by polymerase chain reaction,and 5%–16%of the T1 seedlings showed immunologically active EGFP or GUS protein.Moreover,1.41%of the bar transfected T1 plants were glufosinate resistant,and heritable bar gene was integrated into the maize genome effectively as verified by DNA hybridization.These results demonstrate that exogenous DNA could be delivered efficiently into elite maize inbred lines recalcitrant to tissue culture-mediated transformation and expressed normally through our genotype-independent pollen transfection system.

Effect of strip feeding into mold on fluid flow and heat transfer in continuous casting process

Steel strip feeding into the mold during continuous casting is known as an innovative technology.The newly applied technology is designed to further improve the slab quality.To analyze the complex phase change processes,molten sodium thiosulphate(Na2S2O3-5H2O)was used in the experimental investigation as a transparent analog for metallic alloys.Then,a numerical model incorporating fluid flow,heat transfer and phase change during strip feeding into the mold process was developed.The generalized enthalpy-based method was applied to describe the phase change behavior,and the porous media theory was used to model the blockage of fluid flow by the dendrites in the mushy zone between the strip and melt as well as the solidified shell and melt.The validated model was then used for the simulation of the real strip feeding into the mold process in an industrial scale.The whole shape of the strip under the effect of jet flow from the submerged entry nozzle(SEN)was presented.Results show that the strip will reach a pseudo-steady state after experiencing steel sheath formation,steel sheath melting and strip melting processes.When using the feeding method that is the strip narrow side toward the SEN in the present condition,the strip immersion length can reach 4.5 m below the meniscus and the slab centerline temperature can be decreased by 21 K to a maximum.When the strip feeding speed increased from 0.3 to 0.5 m/s,the minimum temperature of the centerline could be lowered by 4 K or so.