Volumetric lattice Boltzmann method for pore-scale mass diffusionadvection process in geopolymer porous structures

Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material design.In this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous structures.These structures are created using the phase field method(PFM)to precisely control pore architectures.In our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population function.To address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)parallelization.Validation of the developed model involves examining the flow and diffusion fields in porous structures.Remarkably,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,respectively.Notably,all three parameters exert an influence on the diffusion-advection process.Increased background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,respectively.Conversely,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore volume.This comprehensive parametric study provides valuable insights into the kinetics of isotope uptake in porous structures,facilitating the development of porous materials for nuclear waste treatment applications.

可重复加工型生物基热固性自修复聚氨酯树脂的合成与性能

热固性聚氨酯树脂存在不可重复加工等问题,大大降低了材料的使用寿命,同时造成资源浪费。文中以水热法制备了以羟甲基化木质素(Lig-OH)为生物基软段、异佛尔酮二异氰酸酯(IPDI)为硬段、三羟甲基丙烷(TMP)为交联型扩链剂、4,4’-二氨基二苯二硫醚(4-SO)为二次扩链剂、4-甲基伞形酮(4-MU)为生物基封端剂的可重复加工型生物基热固性聚氨酯树脂(LPU)。通过傅里叶变换红外光谱表征其结构,通过光学显微镜、3D轮廓仪等研究其自修复性能,通过拉伸测试、重复加工测试对其力学性能和可重复性进行研究。结果表明,LPU-5(TMP用量为18 mmol)的力学性能最佳,拉伸强度可达18.92 MPa,断裂伸长率可达709.82%,全切修复后分别可达16.90 MPa,630.32%,修复效率为89%,仍具有使用价值。样条全切修复后树脂经粉碎后可以重新加工成完整的聚氨酯膜使用,具备优异的可重复加工性。并且可实现加热及紫外光下的双重修复功能,其中LPU-2在75℃时10 min即可完成划痕修复。

Novel high-voltage cathode for aqueous zinc ion batteries:Porous K_(0.5)VOPO_(4)·1.5H_(2)O with reversible solid-solution intercalation and conversion storage mechanism

Cathode materials that possess high output voltage,as well as those that can be mass-produced using facile techniques,are crucial for the advancement of aqueous zinc-ion battery(ZIBs)applications,Herein,we present for the first time a new porous K_(0.5)VOPO_(4)·1.5H_(2)O polyanionic cathode(P-KIVP)with high output voltage(above 1.2 V)that can be manufactured at room temperature using straightforward coprecipitation and etching techniques.The P-KVP cathode experiences anisotropic crystal plane expansion via a sequential solid-solution intercalation and phase co nversion pathway throughout the Zn^(2+)storage process,as confirmed by in-situ synchrotron X-ray diffraction and ex-situ X-ray photoelectron spectroscopy.Similar to other layered vanadium-based polyanionic materials,the P-KVP cathode experiences a progressive decline in voltage during the cycle,which is demonstrated to be caused by the irreversible conversion into amorphous VO_(x).By introducing a new electrolyte containing Zn(OTF)_(2) to a mixed triethyl phosphate and water solution,it is possible to impede this irreversible conversion and obtain a high output voltage and longer cycle life by forming a P-rich cathode electrolyte interface layer.As a proof-of-concept,the flexible fiber-shaped ZIBs based on modified electrolyte woven into a fabric watch band can power an electronic watch,highlighting the application potential of P-KVP cathode.

High temperature treatment induced production of unreduced 2n pollen in Camellia oleifera

Unreduced gametes through chromosome doubling play a major role in the process of plant polyploidization.Our previous work confirmed that Camellia oleifera can produce natural 2n pollen,and it is possible to induce the 2n pollen formation by high temperature treatment.This study focused on the optimization of the 2n pollen induction technique and the mechanisms of high temperature-induced2n pollen formation in C.oleifera.We found that the optimal protocol for inducing 2n pollen via high temperature was to perform 45℃with4 h at the prophaseⅠstage of the pollen mother cells(PMCs).Meanwhile,high temperature significantly decreased the yield and fertility of2n pollen.Through the observation of meiosis,abnormal chromosome and cytological behaviour was discovered under high-temperature treatment,and we confirmed that the formation of 2n pollen is caused by abnormal cell plate.Based on weighted gene co-expression network analysis,fifteen hub genes related to cell cycle control were identified.After male flower buds were exposed to heat shock,polygalacturonase gene(CoPGX3)was significantly upregulated.We inferred that high temperature causes the CoPGX3 gene to be overexpressed and that CoPGX3 is redistributed into the cytosol where it degrades cytoplasmic pectin,which leads to an abnormal cell plate.Furthermore,abnormal cytokinesis resulted in the formation of dyads and triads,and PMCs divided to produce 2n pollen.Our findings provide new insights into the mechanism of 2n pollen induced by high temperature in a woody plant and lay a foundation for further ploidy breeding of C.oleifera.

Protein arginine methyltransferase-6 regulates heterogeneous nuclear ribonucleoprotein-F expression and is a potential target for the treatment of neuropathic pain

Protein arginine methyltransferase-6 participates in a range of biological functions,particularly RNA processing,transcription,chromatin remodeling,and endosomal trafficking.However,it remains unclear whether protein arginine methyl transferase-6 modifies neuropathic pain and,if so,what the mechanisms of this effect.In this study,protein arginine methyltransferase-6 expression levels and its effect on neuropathic pain were investigated in the spared nerve injury model,chronic constriction injury model and bone cancer pain model,using immunohistochemistry,western blotting,immunoprecipitation,and label-free proteomic analysis.The results showed that protein arginine methyltransferase-6 mostly co-localized withβ-tubulinⅢin the dorsal root ganglion,and that its expression decreased following spared nerve injury,chronic constriction injury and bone cancer pain.In addition,PRMT6 knockout(Prmt6~(-/-))mice exhibited pain hypersensitivity.Furthermore,the development of spared nerve injury-induced hypersensitivity to mechanical pain was attenuated by blocking the decrease in protein arginine methyltransferase-6 expression.Moreover,when protein arginine methyltransferase-6 expression was downregulated in the dorsal root ganglion in mice without spared nerve injury,increased levels of phosphorylated extracellular signal-regulated kinases were observed in the ipsilateral dorsal horn,and the response to mechanical stimuli was enhanced.Mechanistically,protein arginine methyltransferase-6 appeared to contribute to spared nerve injury-induced neuropathic pain by regulating the expression of heterogeneous nuclear ribonucleoprotein-F.Additionally,protein arginine methyltransfe rase-6-mediated modulation of hete rogeneous nuclear ribonucleoprotein-F expression required amino atids 319 to 388,but not classical H3R2 methylation.These findings indicated that protein arginine methyltransferase-6 is a potential therapeutic target fo r the treatment of peripheral neuro pathic pain.

Meter-Scale Thin-Walled Structure with Lattice Infill for Fuel Tank Supporting Component of Satellite:Multiscale Design and Experimental Verification

Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich effect.Such structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other fields.In this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the thin-wall.The designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding technique.Quasi-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled structure.The experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.

Yolk free egg substitute improves the serum phospholipid profile of mice with metabolic syndrome based on lipidomic analysis

In this study,the impacts of egg consumption on mice model of metabolic syndrome(Met S)were comparatively investigated.Mice were divided into five groups(n=8):normal diet group(ND),high-fat diet group(HFD),HFD with whole egg group(WE),HFD with free-yolk egg substitute group(YFES),and HFD with lovastatin group(Lov).Main biochemical indexes and a non-targeted lipidomic analysis were employed to insight the lipid profile changes in serum.It was revealed that WE could significantly improve serum biochemical indexes by reducing body weight,low-density lipoprotein cholesterol(LDL-C)and total cholesterol(TC),while increasing high-density lipoprotein cholesterol.YFES exhibited remarkably better performance in increasing phosphatidylglycerol and phosphatidic acids,while decreasing phosphatidylinositol than WE.A total of 50 differential lipids biomarkers tightly related to glycerophospholipids metabolism were screened out.Carnitine C18:2 and C12:1,SM(d18:0/12:0),and SM(d18:1/14:1)were significantly upregulated in YFES compared to WE.YFES reduced expression of SREBP-1c and Cpt1a,while did not affect the expression of PPAR-α.Sphingomyelin biomarkers were positively related to the TC(|r|>0.6),while PPAR-αwas negatively correlated with triglyceride and LDL-C levels.To sum up,YFES attenuated HFD-induced Met S by improving the serum phospholipids,which account for its modulation of glycerophospholipid metabolism.

miR-196b-5p促进成肌细胞增殖分化

MicroRNA(miRNA)是一类由内源基因编码的长度约为22个核苷酸的非编码单链RNA分子,在动植物中参与转录后基因表达调控。大量研究表明,miRNA调控骨骼肌的发育,主要表现在肌卫星细胞的激活及增殖、分化、肌管的形成等生物学过程。本实验室前期对大白猪背最长肌(longissimus dorsi,LD)和比目鱼肌(soleus muscle,Sol)进行miRNA测序,筛选鉴定到一个在不同骨骼肌中差异表达并且序列高度保守的miR-196b-5p,目前miR-196b-5p在骨骼肌方面的研究尚未见报道。本研究进一步设计合成miR-196b-5p mimics和inhibitor对C2C12细胞进行miR-196b-5p过表达及干扰表达,利用蛋白免疫印迹、实时荧光定量PCR检测、流式细胞术、免疫荧光染色等方法探究miR-196b-5p对成肌细胞增殖分化的影响,并利用生物信息学预测和双荧光素酶报告系统鉴定了miR-196b-5p的靶基因。结果显示,过表达miR-196b-5p显著增加细胞周期基因Cyclin B、Cyclin D和Cyclin E的mRNA和蛋白表达水平(P<0.05);流式细胞周期检测结果显示,过表达miR-196b-5p显著增加S期细胞比例(P<0.05),表明miR-196b-5p能够加快细胞周期进程;EdU染色结果显示,过表达miR-196b-5p显著促进细胞增殖能力;相反,抑制miR-196b-5p的表达可以显著减弱成肌细胞增殖能力。进一步的功能研究发现,过表达miR-196b-5p能够显著增加成肌标志基因MyoD、MyoG和MyHC的表达水平(P<0.05);MyHC免疫荧光染色结果显示miR-196b-5p可以促进成肌细胞肌管形成,表明miR-196b-5p可以促进成肌细胞分化。生物信息学预测和双荧光素酶实验证明miR-196b-5p可以靶向Sirt1基因,抑制该基因的表达。改变Sirt1表达,不能够挽救miR-196b-5p影响细胞周期的表型,可以减弱miR-196b-5p对成肌细胞分化的促进作用,表明miR-196b-5p通过靶向Sirt1促进成肌细胞分化。

Development and application of magnesium alloy parts for automotive OEMs:A review

China is currently vigorously implementing the“energy conservation and emission reduction”and“dual carbon”strategies.As the most resource-advantaged light metal material in China,Magnesium(Mg)alloy is progressively expanding its application in automobile,rail transportation,aerospace,medical,and electronic products.Chongqing University,Shanghai Jiaotong University,and Australian National University have conducted extensive research on the preparation,properties,and processes of Mg alloys.In the past 20 years,the proportion of Mg alloy in the automotive industry has gradually expanded,whereas currently the design and development of Mg alloy parts for automobiles has rarely been reported.Thus,the application models and typical parts cases of Mg alloy are summarized mainly from the four systems of the whole vehicle(body system,chassis system,powertrain system,interior,and exterior system).Subsequently,two actual original equipment manufacturers(OEM)cases are used to introduce the development logic of reliable die-cast Mg alloy,including forward design,formability analysis,process design analysis,structural redesign,manufacturing,and testing,aiming to share the methods,processes,and focus of attention of automotive OEMs for developing Mg alloy parts to enhance the confidence and motivation of applying Mg alloy in automotive field.Eventually,the multiple challenges faced by Mg alloy materials are sorted out and how to face these challenges are discussed.National policies and regulations,environmental protection and energy saving,and consumer demand will continue to promote the application of Mg.

Anti-infection effects of heparin on SARS-CoV-2 in a diabetic mouse model

Severe acute respiratory syndrome coronavirus 2(SARSCo V-2)infection can result in more severe syndromes and poorer outcomes in patients with diabetes and obesity.However,the precise mechanisms responsible for the combined impact of coronavirus disease 2019(COVID-19)and diabetes have not yet been elucidated,and effective treatment options for SARS-Co V-2-infected diabetic patients remain limited.To investigate the disease pathogenesis,K18-h ACE2 transgenic(h ACE2^(Tg))mice with a leptin receptor deficiency(h ACE2-Lepr^(-/-))and high-fat diet(h ACE2-HFD)background were generated.The two mouse models were intranasally infected with a 5×10^(5) median tissue culture infectious dose(TCID_(50))of SARSCo V-2,with serum and lung tissue samples collected at 3days post-infection.The h ACE2-Lepr^(-/-)mice were then administered a combination of low-molecular-weight heparin(LMWH)(1 mg/kg or 5 mg/kg)and insulin via subcutaneous injection prior to intranasal infection with1×10^(4) TCID_(50)of SARS-Co V-2.Daily drug administration continued until the euthanasia of the mice.Analyses of viral RNA loads,histopathological changes in lung tissue,and inflammation factors were conducted.Results demonstrated similar SARS-Co V-2 susceptibility in h ACE2^(Tg)mice under both lean(chow diet)and obese(HFD)conditions.However,compared to the h ACE2-Lepr^(+/+)mice,h ACE2-Lepr^(-/-)mice exhibited more severe lung injury,enhanced expression of inflammatory cytokines and hypoxia-inducible factor-1α(HIF-1α),and increased apoptosis.Moreover,combined LMWH and insulin treatment effectively reduced disease progression and severity,attenuated lung pathological changes,and mitigated inflammatory responses.In conclusion,preexisting diabetes can lead to more severe lung damage upon SARS-Co V-2 infection,and LMWH may be a valuable therapeutic approach for managing COVID-19patients with diabetes.

有机硅改性聚氨酯的自修复及环境响应行为

通常自修复聚氨酯的耐高温性及疏水性欠佳,且存在修复手段单一、室温等温和条件下修复缓慢等问题,因此限制了自修复聚氨酯的广泛应用。文中以聚四氢呋喃二醇(PTMEG)和端羟基聚二甲基硅氧烷(PDMS-OH)与异佛尔酮二异氰酸酯(IPDI)合成预聚体,以4,4’-二氨基二苯二硫醚(ODD)作为含有动态二硫键的刚性扩链剂,4-甲基伞形酮(4-MU)作为含有可逆环结构的封端剂,制得室温下具备红外光照修复功能的有机硅改性聚氨酯(SiPU)。研究了含有二硫键的刚性扩链剂(ODD)的添加量对SiPU各项性能的影响,以及添加端羟基聚二甲基硅氧烷(PDMS-OH)对SiPU耐热性、疏水性的影响。再将自制的聚吡咯修饰碳纳米管(PPY/CNTs)作为导电填料,将其与SiPU超声共混制得具备多重响应性的自修复有机硅改性聚氨酯(CSiPU)。通过光学显微镜、3D光学干涉仪、万能试验机等证明了SiPU均可实现在室温(25℃)10μm红外光照射下的自修复,其中多元醇与扩链剂摩尔比为3:1的SiPU3修复效果最佳,全切修复效率达到88%,划痕修复效率达到100%;通过热失重分析及接触角测量表明,有机硅结构的引入使SiPU的热稳定性及疏水性有一定提升;通过数字万用表验证了CSiPU可实现对温度及化学环境的响应行为。

Enabling stable 4.6 V LiCoO_(2) cathode through oxygen charge regulation strategy

LiCoO_(2) is the preferred cathode material for consumer electronic products due to its high volumetric energy density. However, the unfavorable phase transition and surface oxygen release limits the practical application of LiCoO_(2)at a high-voltage of 4.6 V to achieve a higher energy density demanded by the market. Herein, both bulk and surface structures of LiCoO_(2)are stabilized at 4.6 V through oxygen charge regulation by Gd-gradient doping. The enrichment of highly electropositive Gd on LiCoO_(2) surface will increase the effective charge on oxygen and improve the oxygen framework stability against oxygen loss.On the other hand, Gd ions occupy the Co-sites and suppress the unfavorable phase transition and microcrack. The modified LiCoO_(2) exhibits superior cycling stability with capacity retention of 90.1% over 200 cycles at 4.6 V, and also obtains a high capacity of 145.7 m Ah/g at 5 C. This work shows great promise for developing high-voltage LiCoO_(2) at 4.6 V and the strategy could also contribute to optimizing other cathode materials with high voltage and large capacity, such as cobalt-free high-nickel and lithiumrich manganese-based cathode materials.

Observer-Based Path Tracking Controller Design for Autonomous Ground Vehicles With Input Saturation

This paper investigates the problem of path tracking control for autonomous ground vehicles(AGVs),where the input saturation,system nonlinearities and uncertainties are considered.Firstly,the nonlinear path tracking system is formulated as a linear parameter varying(LPV)model where the variation of vehicle velocity is taken into account.Secondly,considering the noise effects on the measurement of lateral offset and heading angle,an observer-based control strategy is proposed,and by analyzing the frequency domain characteristics of the derivative of desired heading angle,a finite frequency H_∞index is proposed to attenuate the effects of the derivative of desired heading angle on path tracking error.Thirdly,sufficient conditions are derived to guarantee robust H_∞performance of the path tracking system,and the calculation of observer and controller gains is converted into solving a convex optimization problem.Finally,simulation examples verify the advantages of the control method proposed in this paper.

MXene-Based Quantum Dots Optimize Hydrogen Production via Spontaneous Evolution of Cl-to O-Terminated Surface Groups

MXene quantum dots(MQDs)offer wide applications owing to the abundant surface chemistry,tunable energy-level structure,and unique properties.However,the application of MQDs in electrochemical energy conversion,including hydrogen evolution reaction(HER),remains to be realized,as it remains a challenge to precisely control the types of surface groups and tune the structure of energy levels in MQDs,owing to the high surface energy-induced strong agglomeration in post-processing.Consequently,the determination of the exact catalytically active sites and processes involved in such an electrocatalysis is challenging because of the complexity of the synthetic process and reaction conditions.Herein,we demonstrated the spontaneous evolution of the surface groups of the Ti_(2)CT_(x)MQDs(x:the content of O atom),i.e.,replacement of the-Cl functional groups by O-terminated ones during the cathode reaction.This process resulted in a low Gibbs free energy(0.26 eV)in HER.Our steady Ti_(2)CO_(x)/Cu_(2)O/Cu foam systems exhibited a low overpotential of 175 mV at 10 mA cm^(-2)in 1 M aq.KOH,and excellent operational stability over 165 h at a constant current density of-10 mA cm^(-2).

Natural variants and editing events provide insights into routes for spike architecture modification in common wheat

Spike architecture is an indicative trait of grain yield in common wheat(Triticum aestivum).A segregating population was generated for mapping genes contributing to spike morphometric traits by crossing the two common wheat cultivars'CItr 17600'with branching spikes and'Yangmai 18'with normal spikes.A major quantitative trait locus for spike length was mapped to the Q5A region of chromosome 5A.Yangmai18 carried a Q5Ab allele for short spikes,which harbored one SNP in the last intron,and a 1-bp InDel in the 720-bp fragment from the start codon,compared to Q5Aa in Chinese Spring.CItr 17600 harbored a q5Ab allele for long spikes,which has a 6-bp deletion compared to the reported q5Aa allele that was involved in the binding site of microRNA 172(miR172).This 6-bp deletion in immediately upstream of this binding site was involved in changes of four amino acids.The natural q5A allele appeared to be rare in common wheat but frequent in tetraploid T.turgidum accessions with branching spikes.The CRISPR/Cas9 technology was used to edit the upstream region involving in the miR172 binding site in Yangmai 18 and identified two independent editing events,one with a 1-bp insertion in Q5A and the other with a 2-bp deletion in Q5D,resulting in several shapes of spikes in the transgenic progeny.In addition to the effects of natural q5A allele and the edited Q5A genes,this study indicated the regeneratability and transformability of Yangmai 18 as an elite cultivar.Altogether,this study provides insight into future modification and engineering of spike architecture in common wheat.

血清免疫球蛋白GN-糖基的高通量分析——一种消化道癌症的非侵入性生物标志物

免疫球蛋白G(Immunoglobulin G,IgG)的N-糖基化在炎症性疾病的发展中起着重要作用。本研究旨在评价IgG N-糖基在消化道癌症亚型中的诊断效能。从中国医学科学院肿瘤医院招募749名消化道癌症患者,包括食管癌(esophageal cancer,EC)、胃癌(gastric cancer,GC)、结直肠癌(colorectal cancer,CRC)和胰腺癌(pancreatic cancer,PC)患者。采用亲水交互高效液相色谱-超高效液相色谱(hydrophilic interaction liquid chromatography using ultra-performance liquid chromatography,HILIC-UPLC)分析血浆中IgG的N-糖基构成。采用Bio-Plex悬液芯片系统检测方法(Bio-Rad)进行炎症因子检测。采用典型相关分析(canonical correlation analysis,CCA)探索糖基和炎症因子之间的相关性。采用LASSO回归和logistic回归模型,基于检测到的糖基谱建立可用于区分胃肠癌症患者和健康人群诊断模型。与健康对照组相比,EC、GC、CRC和PC患者的唾液酸化和半乳糖基化水平降低,而二等分乙酰葡萄糖胺基化水平在消化道癌症患者中升高。此外,只有胰腺癌患者具有低水平的岩藻糖基化。消化道癌症组的IL-1β、IL-31和sCD40L水平均高于对照组。IgG N-糖基的组成与炎症因子相关(r=0.556)。基于糖基的模型表现出良好的诊断效能,EC、GC、CRC和PC的受试者工作特征曲线下面积(AUC)分别为0.972、0.871、0.867和0.907。这些研究结果表明,IgG N-糖基在调节消化道肿瘤的发病机制中发挥了重要作用。血清IgG N-糖基可以作为潜在的非侵入性辅助消化道癌症临床诊断的方法。

Explicit Topology Optimization Design of Stiffened Plate Structures Based on the Moving Morphable Component(MMC)Method

This paper proposes an explicit method for topology optimization of stiffened plate structures.The present work is devoted to simultaneously optimizing stiffeners’shape,size and layout by seeking the optimal geometry parameters of a series of moving morphable components(MMC).The stiffeners with straight skeletons and the stiffeners with curved skeletons are considered to enhance the modeling and optimization capability of the current approach.All the stiffeners are represented under the Lagrangian-description framework in a fully explicit way,and the adaptive ground structure method,as well as dynamically updated plate/shell elements,is used to obtain optimized designs with more accurate analysis results.Compared with existing works,the proposed approach provides an explicit description of the structure.Thus,a stiffened plate structure with clear stiffener distribution and smooth geometric boundary can be obtained.Several numerical examples provided,including straight and curved stiffeners,hierarchical stiffeners,and a stiffened plate with a cutout,validate the effectiveness and applicability of the proposed approach.

熔体流淌条件对橡胶生胶燃烧行为的影响

为探究熔体流淌条件对橡胶生胶燃烧行为的影响,文中选取天然橡胶(NR)、顺丁橡胶(BR)和丁苯橡胶(SBR)为研究对象,在自制熔体流淌火灾试验装置上进行燃烧实验,得到质量损失速率(MLR)、气相温度、池火面积等数据。研究结果表明,流淌燃烧条件下3种橡胶的MLR峰值、气相温度和燃烧速度均高于不流淌燃烧条件的,且燃烧时间缩短为不流淌燃烧时的一半,这与熔体流淌扩大了池火的面积有关。流淌条件下橡胶的MLR与池火面积呈线性关系,达到相同MLR时的池火面积大小顺序为NR>SBR>BR。气相温度峰值大小顺序为BR>NR>SBR,这与橡胶样品的平均有效燃烧热(AEHC)、MLR峰值和池火面积有关。

肺结节患者焦虑抑郁与Th17/Treg和炎症水平改变的相关性研究

背景与目的肺癌的发病率逐年攀升,人们在体检时尤其注重对肺进行检查,得益于低剂量计算机断层扫描技术的普及,不仅肺癌能够得到早期诊断,很多肺结节也在体检时被发现,并成为当下不可忽视的重要健康问题。肺结节患者极易出现焦虑、抑郁等不良情绪,研究表明情绪障碍患者存在机体免疫功能失调和炎症水平变化,本研究旨在探讨肺结节患者焦虑抑郁与Th17/Treg和炎症水平改变的相关性。方法纳入2019年4月-2019年7月就诊于安徽医科大学第一附属医院门诊受试者共143例,采用贝克焦虑量表(Beck Anxiety Inventory,BAI)、贝克抑郁量表第二版(Beck Depression Inventory-Ⅱ,BDI-Ⅱ)进行评估。其中健康对照(healthy control,HC)组40例;肺结节患者103例,依据量表评分分为焦虑和(或)抑郁(anxiety and/or depression,AD)组41例和无焦虑抑郁(non-anxiety and non-depression,NAD)组62例。检测外周血辅助性T细胞17(T helper cell 17,Th17)、调节T细胞(regulatory T cells,Tregs)百分比,计算Th17细胞绝对值;检测血清炎症因子,并分析组间差异及相关性。结果三组间Th17细胞百分比、Th17细胞绝对数、Th17/Treg、白细胞介素-2(interleukin-2,IL-2)、IL-6、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)水平的差异有统计学意义(均P<0.001),AD组高于HC组和NAD组(均P<0.05),HC组和NAD组间差异无统计学意义(均P>0.05)。以上指标与焦虑、抑郁的严重程度无显著相关性(P>0.05)。Tregs百分比、IL-4、IL-10水平在各组间差异无统计学意义(均P>0.05)。女性肺结节患者焦虑和(或)抑郁比例高于男性(P<0.05)。结论肺结节患者易出现不同程度的焦虑、抑郁的情绪变化,进而导致机体出现免疫功能失调和低级别炎症。

阳离子丙烯酸酯膜的制备及在微藻培养中的应用

以丙烯酸正丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为共聚单体制备了阳离子丙烯酸酯乳液,考察了搅拌速率、单体比例、乳化剂和引发剂用量对乳液聚合的影响。结果表明,当搅拌速率为400 r/min,m(BA)∶m(MMA)=30∶70,OP-10和AIBI质量分别为单体质量的4.5%和1%时,制备的乳液及膜性能最佳。进一步研究了阳离子丙烯酸酯膜用作贴壁材料对微藻培养的影响,实验发现,培养10 d后膜材料保持完整,强度韧性较好,微藻在膜上附着生长迅速,其生长量与膜表面粗糙度、带电荷量等表面参数呈正相关。其研究结果为寻求和制备具有潜质的微藻培养贴壁材料提供了新思路和新方法。