The miR-9-5p/CXCL11 pathway is a key target of hydrogen sulfide-mediated inhibition of neuroinflammation in hypoxic ischemic brain injury

We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.

The MADS-box gene RhAGL6 plays a master role in regulating the receptacle malformation in rose at low temperature

Low temperature usually results in the developmental deformity of flower organs,immensely affecting the quality of rose flowers.However,it's largely unknown about the regulatory mechanisms activated by low temperature.Here,we used a low temperature-sensitive Rosa hybrida cv.‘Peach Avalanche’to screen a MADS-box gene RhAGL6 via conjoint analysis between RNA sequencing(RNA-seq)and whole-genome bisulfite sequencing(WGBS).Furthermore,we found that low temperature induced the hypermethylation and elevated histone 3 lys-27 trimethylation(H3K27me3)level on the RhAGL6 promoter,leading to decreased RhAGL6 expression.In addition,RhAGL6 silencing resulted in the formation of abnormal receptacles.We also found that the levels of gibberellins(GA3)and abscisic acid(ABA)in the receptacle under low temperature were lower and higher,respectively,than under normal temperature.Promoter activity analysis revealed that GA3 significantly activated RhAGL6 promoter activity,whereas ABA inhibited it.Thus,we propose that RhAGL6 regulates rose receptacle development by integrating epigenetic regulation and phytohormones signaling at low temperature.

Evaluation of Technical Education by Using a Modern Structured MOODLE Laboratory Course, in Relation to Recent Data

E-learning platforms support education systems worldwide, transferring theoretical knowledge as well as soft skills. In the present study high-school pupils’, and adult students’ opinions were evaluated through a modern structured MOODLE interactive course, designed for the needs of the laboratory course “Automotive Systems”. The study concerns Greek secondary vocational education pupils aged 18 and vocational training adult students aged 20 to 50 years. The multistage, equal size simple random cluster sample was used as a sampling method. Pupils and adult students of each cluster completed structured 10-question questionnaires both before and after attending the course. A total of 120 questionnaires were collected. In general, our findings disclosed that the majority of pupils and adult students had significantly improved their knowledge and skills from using MOODLE. They reported strengthening conventional teaching, using the new MOODLE technology. The satisfaction indices improved quite, with the differences in their mean values being statistically significant.

Loss of LBP triggers lipid metabolic disorder through H3K27 acetylation-mediated C/EBPβ-SCD activation in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were established and used to conduct integrative targetingactive enhancer histone H3 lysine 27 acetylation(H3K27ac)chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency.Notably,LBP^(-/-)reduced the inflammatory response but markedly aggravated high-fat diet(HFD)-induced NAFLD in rats,with pronounced alterations in the histone acetylome and regulatory transcriptome.In total,1128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type(WT)and LBP^(-/-)NAFLD rats.Based on integrative analysis,CCAAT/enhancer-binding proteinβ(C/EBPβ)was identified as a pivotal transcription factor(TF)and contributor to dysregulated histone acetylome H3K27ac,and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD.This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβand functional gene SCD as potential regulators and therapeutic targets.

免疫性血小板输注无效患者HLA/HPA抗体特性分析及其对血小板输注效果的影响

目的 探讨免疫性血小板输注无效(PTR)患者HLA/HPA抗体特异性分布特征及其对血小板输注效果的影响。方法 本研究以86例免疫性PTR患者为研究对象,收集其性别、年龄、身高、体重、配血次数、疾病类型、输注前后血小板计数等临床资料,通过微珠法进行HLA特异性抗体的检测,并分析抗体特性对血小板输注效果的影响。结果 86例PTR患者中,单独HLA抗体、单独HPA抗体、HLA+HPA抗体阳性的患者分别为72例(83.72%)、8例(9.30%)、6例(6.98%)。HLA抗体在各位点中检出频率最高的抗体对应等位基因分别为A*25:01、B*15:12、C*02:02(和C*17:01),检出率分别为81.48%、87.04%、48.15%;而对应抗原表位出现频率最高的前三位为163LG、97V、71ATD,检出率分别为87.04%、77.78%、74.07%。仅存在HLA抗体的患者,输注交叉配型相合血小板的24 h血小板计数纠正增加指数(CCI)及输注有效情况均明显优于随机血小板(P<0.01)。在血小板交叉配型阴性结果的患者中,HLA抗体强度与交叉配型相合血小板的24 h CCI值及输注有效情况呈负相关关系,强度越高,输注效果越差(P<0.01)。HLA抗体强度为中、低等水平的患者,输注交叉配型相合血小板的24 h CCI值及输注有效情况均优于输注随机血小板(P<0.05)。结论 本研究所得到的PTR患者HLA/HPA抗体特性及其对血小板输注效果影响的结果,可为血小板库建立时供者的选择提供指导,同时对临床PTR患者的治疗方式选择有一定的参考价值。

Durable hierarchical phosphorus‐doped biphase MoS_(2)electrocatalysts with enhanced H^(*)adsorption

Phase engineering is an efficient strategy for enhancing the kinetics of electrocatalytic reactions.Herein,phase engineering was employed to prepare high‐performance phosphorous‐doped biphase(1T/2H)MoS_(2)(P‐BMS)nanoflakes for hydrogen evolution reaction(HER).The doping of MoS_(2)with P atoms modifies its electronic structure and optimizes its electrocatalytic reaction kinetics,which significantly enhances its electrical conductivity and structural stability,which are verified by various characterization tools,including X‐ray photoelectron spectroscopy,high‐resolution transmission electron microscopy,X‐ray absorption near‐edge spectroscopy,and extended X‐ray absorption fine structure.Moreover,the hierarchically formed flakes of P‐BMS provide numerous catalytic surface‐active sites,which remarkably enhance its HER activity.The optimized P‐BMS electrocatalysts exhibit low overpotentials(60 and 72 mV at 10 mA cm^(−2))in H_(2)SO_(4)(0.5 M)and KOH(1.0 M),respectively.The mechanism of improving the HER activity of the material was systematically studied using density functional theory calculations and various electrochemical characterization techniques.This study has shown that phase engineering is a promising strategy for enhancing the H*adsorption of metal sulfides.

Chlorogenic acid ameliorates heart failure by attenuating cardiomyocyte ferroptosis

Objective:To elucidate the effects of chlorogenic acid(CGA),a bioactive polyphenol compound prevalent in traditional Chinese medicine and various foods,including Lonicera japonica Thunb.(Jin Yin Hua),Eucommia ulmoides Oliv.(Du Zhong Ye),tea,and coffee,on cardiomyocyte ferroptosis and heart failure.Methods: We assessed the effect of CGA on cardiac function using a mouse model of heart failure induced by transverse aortic constriction(TAC).These indicators included the left ventricular ejection fraction(LVEF),fractional shortening(LVFS),end-systolic volume(LVESV),end-diastolic volume(LVEDV),end-systolic diameter(LVESD),and end-diastolic diameter(LVEDD).An isoprenaline hydrochloride(ISO)-induced H9c2 cardiomyocyte cell model was also established,and the cells were treated with various concentrations of CGA.To assess the effect of CGA on ferroptosis in cardiomyocytes,we measured cell viability and evaluated the levels of intracellular reactive oxygen species(ROS),ferrous ions(Fe^(2+)),and lipid peroxidation using fluorescent staining.To clarify the ferroptosis signaling pathway regulated by CGA,western blotting was used to examine the expression of ferroptosis biomarkers,specifically solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),in H9c2 cardiomyocytes and mouse myocardial tissues.Results: CGA significantly enhanced cardiac performance indices such as LVEF,LVFS,LVESV,LVEDV,LVESD,and LVEDD.H9c2 cardiomyocytes exposed to ISO showed decreased cell viability and increased ROS levels,Fe^(2+)content,and lipid peroxidation levels.However,CGA treatment significantly ameliorated these changes.Additionally,in both H9c2 cardiomyocytes and myocardial tissue obtained from mice with TAC,CGA increased the expression of ferroptosis-related proteins,including SLC7A11 and GPX4.Conclusion: CGA has the potential to enhance cardiac function and diminish lipid peroxidation and ROS levels in cardiomyocytes via the SLC7A11/GPX4 signaling pathway.This process alleviates ferroptosis in cardiomyocytes.These results provide new insights into the clinical use of CGA and the management of heart failure.

Mechanism of Tea Polyphenols in Alleviating Thermal Damage Based on Network Pharmacology

[Objective]This paper was to investigate the action targets and pathways of tea polyphenols in alleviating heat stress-induced injury by using network pharmacological analysis and an H9C2 cell model.[Method]First,the corresponding targets of tea polyphenols were obtained from the PubChem database.Then,the core targets were screened based on topological parameters.The relevant metabolism pathways of tea polyphenols related to diseases were identified through GO functional annotation and KECG signaling pathway enrichment.Moreover,common targets for thermal injury and targets of tea polyphenols were obtained.Then,GO functional annotation was performed to explore the pathway of tea polyphenols in alleviating heat stress damage.H9C2 cells were cultured at 42 C to construct the heat stress model,and the cells were treated with 10μg/mL tea polyphenols.The key genes were confirmed using RT-PCR technology.[Result]The study yielded 364 targets corresponding to tea polyphenols,including 68 core targets.These targets are related to various biological processes such as involve oxidative stress,cancer,lipopolysaccharide-mediated signaling pathways,antiviral responses,regulation of cellular response to heat,apoptosis,and cellular lipid metabolic metabolism.Tea polyphe nols alleviate thermal damage by targeting BCL2,HSP90AA1,HSPA1A,JUN,MAPK1,NFKB1,NFKBIA,NOS3,and TP53.Moreover,10 mg/L tea polyphenols were found to upregulate the transcription levels of Hsp70,HO-1,NQ-O1,Nrf2,and MAPKI,and the transcription levels of Bax/Bcl2,p38,and JNK were downregulated to alleviate the heat stress-induced injury.[Conclusion]Tea polyphenols may enhance the antioxidant ability of H9C2 cells and inhibit cell apoptosis,thereby reducing heat stress injury.

Microstructure and martensitic transformation in quaternary NiTiHfV alloy

The effect of age hardening on the microstructure,martensitic transformation behavior,and shape memory properties of the(Ni_(50)Ti_(30)Hf_(20))_(95)V_(5)alloy was investigated by scanning electron microscopy,transmission electron microscopy,X-ray diffraction,differential scanning calorimetry,microhardness,and bending tests.The results demonstrate a significant influence of V addition on the microstructure of the alloy.V addition leads to the formation of a(Ni,V)_(2)(Ti,Hf)-type Laves phase,which coexists with B19'martensite at room temperature.Aging at 550℃results in precipitation hardening due to the formation of nano-scale orthorhombic H-phase,with the peak hardness observed after 3 h of aging.The alloy at peak hardness state exhibits higher transformation strain and lower unrecovered strain compared to the solution-treated sample.The aged sample achieves a maximum transformation strain of 1.56%under 500 MPa.

H1N1、H3N2亚型流感病毒Mosaic-HA1的表达及对小鼠的免疫原性评价

流感病毒给全球公共卫生带来了严重威胁,疫苗接种是预防流感及严重并发症的有效手段。本研究分析了北半球2012–2022年间人类甲型流感病毒(influenza A virus,IAV)流行株血凝素(hemagglutinin,HA)中HA1亚基的氨基酸突变趋势和抗原显性位点变化情况。基于世界卫生组织(World Health Organization,WHO)公布的2022年北半球流感疫苗推荐株A/Wisconsin/588/2019(H1N1)和A/Darwin/6/2021(H3N2)的HA1氨基酸序列,通过马赛克(mosaic)遗传算法设计了3种Mosaic-HA1抗原并将其在293F细胞中进行表达、纯化。将纯化后的Mosaic-HA1抗原与明矾佐剂以1:1的体积比混合制备亚单位疫苗并免疫BALB/c小鼠以评价免疫效果。酶联免疫吸附实验表明Mosaic-HA1抗原能产生同时结合两种亚型HA1的IgG,其中结合H3蛋白、H1蛋白的特异性效价IgG效价分别达到10~5、10~3以上,攻毒实验表明Mosaic-HA1能抵抗H3N2和H1N1流行毒株的攻击。本研究通过对不同亚型IAV毒株HA1中免疫显性位点进行重新组合,为多价亚单位流感疫苗开发提供了新思路。

HB-Continuous Mappings in L-Topological Space

In this paper, we introduce and study the notion of HB-closed sets in L-topological space. Then, HB-convergence theory for L-molecular nets and L-ideals is established in terms of HB-closedness. Finally, we give a new definition of fuzzy H-continuous [1] which is called HB-continuity on the basis of the notion of H-bounded L-subsets in L-topological space. Then we give characterizations and properties by making use of HB-converges theory of L-molecular nets and L-ideals.

An Explanation of the Temperature-Dependent Upper Critical Field Data of H3S on the Basis of the Thermodynamics of a Superconductor in a Magnetic Field

Excellent fits to a couple of the data-sets on the temperature (T)-dependent upper critical field (Hc2) of H3S (critical temperature, Tc ≈ 200 K at pressure ≈ 150 GPa) reported by Mozaffari, et al. (2019) were obtained by Talantsev (2019) in an approach based on an ingenious mix of the Ginzberg-Landau (GL), the Werthamer, Helfand and Hohenberg (WHH), and the Gor’kov, etc., theories which have individually been employed for the same purpose for a long time. Up to the lowest temperature (TL) in each of these data-sets, similarly accurate fits have also been obtained by Malik and Varma (2023) in a radically different approach based on the Bethe-Salpeter equation (BSE) supplemented by the Matsubara and the Landau quantization prescriptions. For T TL, however, while the (GL, WHH, etc.)-based approach leads to Hc2(0) ≈ 100 T, the BSE-based approach leads to about twice this value even at 1 K. In this paper, a fit to one of the said data-sets is obtained for the first time via a thermodynamic approach which, up to TL, is as good as those obtained via the earlier approaches. While this is interesting per se, another significant result of this paper is that for T TL it corroborates the result of the BSE-based approach.

h-Said-Ball基与h-Said-Ball曲线

h-Bezier曲线是Bezier曲线基于h-微积分意义下的推广模型.为增强Said-Ball曲线的造型能力,提高h-Bezier曲线递归求值速度,该文提出任意次的h-Said-Ball基函数,构造了h-Said-Ball曲线.通过分析Said-Ball曲线递归求值算法与Bezier曲线的转化关系,结合h-Bezier曲线的递归求值算法和h-Bernstein基函数的构造方式,得到任意次h-Said-Ball基函数的表达式.h-Said-Ball基具有非负,单位分解,端点插值等优良性质,和h-Bernstein基之间存在显式转换矩阵.进一步,定义h-Said-Ball曲线并分析其基本性质,推导递归求值算法和包络表示,h-Said-Ball曲线的求值计算量是h-Bezier曲线的一半.借助从h-Said-Ball曲线到h-Bezier曲线的割角算法,证明了h-Said-Ball基是全正基,从而h-Said-Ball曲线具有变差缩减性和保凸性.数值实例显示了h-Said-Ball曲线相比Said-Ball曲线的造型优势和灵活性.

2022-2023年山东省A(H1N1)pdm09流感病毒HA、NA基因变异特征分析

目的 了解山东省2022-2023流感监测年度分离的A(H1N1)pdm09亚型流感病毒血凝素(hemagglutinin,HA)和神经氨酸酶(neuraminidase,NA)基因的变异特征,为流感的防控提供科学依据。方法 从流感监测网络实验室分离的流感毒株中按地市随机选取14株A(H1N1)pdm09亚型流感毒株,以WHO推荐的当季疫苗株为参考进行全基因组测序,并采用荧光法开展神经氨酸酶抑制(neuraminidase inhibition,NI)实验以评估药物敏感性。结果 山东省2022-2023年度分离的A(H1N1)pdm09流感病毒属于6B.1A分支中的5a.2a进化簇,核苷酸序列比对分析显示,HA和NA基因与2021-2023年度北半球疫苗株A/Victoria/2570/2019的亲缘关系较为接近,同源性分别为98.5%~98.7%和98.8%~99.1%。氨基酸序列分析显示,HA蛋白有20个位点发生了氨基酸序列变异,并发现1株病毒可能发生抗原漂移,有3株病毒发生了HA蛋白糖基化位点的缺失。NA酶相关重要位点未发生变异。NI实验显示,所测流感毒株均对抗流感病毒药物敏感。结论 所监测毒株与疫苗株整体同源性很高,但氨基酸存在一定程度变异,今后有必要持续开展流感病毒基因变异特征监测以了解流感流行的风险,以及评价基因变异对流感疫苗和治疗药物效果的影响。

Precisely Control Relationship between Sulfur Vacancy and H Absorption for Boosting Hydrogen Evolution Reaction

Ef fective and robust catalyst is the core of water splitting to produce hydrogen.Here, we report an anionic etching method to tailor the sulfur vacancy(VS) of NiS_(2) to further enhance the electrocatalytic performance for hydrogen evolution reaction(HER). With the VS concentration change from 2.4% to 8.5%, the H* adsorption strength on S sites changed and NiS_(2)-VS 5.9% shows the most optimized H* adsorption for HER with an ultralow onset potential(68 m V) and has long-term stability for 100 h in 1 M KOH media. In situ attenuated-total-reflection Fourier transform infrared spectroscopy(ATR-FTIRS) measurements are usually used to monitor the adsorption of intermediates. The S-H* peak of the Ni S_(2)-VS 5.9% appears at a very low voltage, which is favorable for the HER in alkaline media. Density functional theory calculations also demonstrate the Ni S_(2)-VS 5.9% has the optimal |ΔG^(H*)| of 0.17 e V. This work offers a simple and promising pathway to enhance catalytic activity via precise vacancies strategy.

拟南芥液泡型H^(+)-ATP酶E1亚基编码基因AtTUF的研究进展

液泡型H^(+)-ATP酶(Vacuolar-H+-ATPase,V-ATP酶,VHA)是存在于所有真核生物中的一类质子泵,主要存在于植物液泡膜、高尔基体及胞内体等内膜系统上,在维持真核细胞内膜区室的pH稳态过程中发挥着重要作用.V-ATP酶是一种多亚基蛋白复合体,由亲水的头部V_(1)和疏水的基部V_(0)两个区域组成,V_(1)位于膜外胞质区,呈球茎状,由A~H 8个亚基组成,主要负责ATP的水解;V_(0)整合于膜中,由a、c、c''、d、e 5个亚基组成,主要负责质子易位.在拟南芥中,V-ATP酶的大多数亚基由包含2~5个成员的小基因家族编码,其中VHA的E亚基由3个具有差异表达的同工型基因编码,在种子发育期间,VHA-E1是胚胎发生过程中的主要同工型,VHA-E2具有花粉特异性,而VHA-E3主要在胚乳和周围的母体组织中表达.VHA-E1亚基由AtTUF基因(又被称为TUFF,EMB2448,VHA-E1,VHAE1,基因号AT4G11150)编码,与跨液泡膜的物质运输密切相关,在体细胞发育过程中对维持功能性分泌系统及植物对各种非生物胁迫的响应过程中均起着重要作用.论文综述了拟南芥中AtTUF的研究进展,以期为相关领域的研究提供参考.

Black Hole Complementarity in Terms of the Outsider and Insider Perspectives

A complementarity hypothesis concerning outsider and insider perspectives of a gargantuan black hole is proposed. The two thought experiments presented herein are followed by a brief discussion of a new interpretation of black hole interior “space-and-time-reversal”. Specifically, it is proposed that the “singularity” space of the black hole interior is time-like and the expansion time of the black hole interior is space-like. The resemblance of this new insider interpretation to our own expanding and redshifting big bang universe is compelling.

H3和IDH野生型弥漫性儿童型高级别胶质瘤6例临床病理分析

目的探讨中枢神经系统H3和IDH野生型弥漫性儿童型高级别胶质瘤的临床病理学及分子特征。方法收集上海交通大学医学院附属新华医院病理科诊断的6例H3和IDH野生型弥漫性儿童型高级别胶质瘤的临床病理资料,采用免疫组化(全自动免疫组化染色仪)检测GFAP、Olig2、Syn、NeuN、IDH1、H3K27M等蛋白的表达,FISH法检测EGFR、MYCN基因扩增,Sanger测序检测IDH、H3F3A、TERT基因突变,并复习相关文献。结果本组6例患者年龄范围5~11岁,中位年龄7.5岁。其中男性2例,女性4例,男女比1∶2。临床症状表现为肢体乏力、偏瘫、呕吐、抽搐、视物模糊等。肿瘤发生部位:5例位于幕上,1例位于幕下脑干和小脑。组织学形态:3例表现为高级别胶质瘤形态学特征,其中2例伴有瘤巨细胞;2例表现为胚胎性肿瘤样特征,1例同时具有高级别胶质瘤及胚胎性肿瘤样形态学特点。5例伴有微血管增生和(或)坏死;1例间质黏液变/微囊形成。免疫表型:肿瘤细胞GFAP(6/6)和Olig2(6/6)部分或局灶阳性,Syn(3/6)和NeuN(1/6)局灶或散在阳性,IDH1、H3K27M、H3G34V和H3G34R均阴性,ATRX、H3K27me3、INI1、BRG1均弥漫阳性(6/6)。p53阳性5%~95%不等,Ki67增殖指数40%~90%。分子检测示6例均为IDH1/2和H3F3A野生型;2例MYCN扩增;2例EGFR扩增伴多倍体;1例同时伴有EGFR扩增和MYCN扩增;1例PDGFRA扩增。治疗及随访情况,术后放疗和(或)替莫唑胺化疗;3例于术后1~5个月死亡;2例存活,随访截至2024年1月,分别随访4个月和7个月;1例失访。结论H3和IDH野生型弥漫性儿童型高级别胶质瘤是一种高度恶性肿瘤,组织学表现为胶质母细胞瘤样或胚胎性肿瘤样特征,根据分子遗传学特征分为RTK1、RTK2、MYCN三种分子亚型,其中MYCN亚型预后最差。诊断时应注意与其他儿童型或成人型高级别胶质瘤及胚胎性肿瘤鉴别。

ZrO_(2)(AlN)/h-BN复合陶瓷性能研究及超重力凝固坩埚研制

凝固是制备材料很基本的成型技术之一,但超重力凝固时,高转速产生的离心力克服合金熔体在坩埚孔隙处产生的表面张力,极易在超重力凝固过程中发生熔体渗漏或坩埚破碎,导致实验失败。本工作采用热压烧结工艺制备ZrO_(2)/h-BN和AlN/h-BN复合陶瓷,测试其物理和力学性能,择优选材加工成坩埚。结果表明,AlN/h-BN的热导率优于ZrO_(2)/h-BN,其高温压缩强度明显高于ZrO_(2)/h-BN。基于超重力凝固时坩埚损伤的力学分析,选用低密度、高热导率、高压缩强度的AlN/h-BN制备坩埚,通过50炉超重力凝固实验,验证其性能满足超重力凝固的需要。

Antibacterial mechanism of kojic acid and tea polyphenols against Escherichia coli O157:H7 through transcriptomic analysis

Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.