间歇低氧大鼠脂肪因子chemerin的表达与糖脂代谢关系研究

目的通过检测间歇低氧大鼠血清chemerin的表达水平,探讨脂肪因子chemerin在OSAHS相关糖脂代谢紊乱中的作用。方法选取健康雄性Wistar大鼠24只随机分4组:常氧+普通饮食组(NC+ND组)、常氧+高脂饮食组(NC+HFD组)、间歇低氧+普通饮食组(IH+ND组)、间歇低氧+高脂饮食组(IH+HFD组)。ND组给予基础饲料喂养,HFD组予以高脂饲料喂养。IH组暴露于8h/d的间歇低氧环境中,同时NC组给予间歇压缩空气。检测大鼠血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、空腹血糖(FPG)、空腹胰岛素(FINS)水平,用稳态模型胰岛素抵抗指数(IRI)及胰岛素敏感指数(ISI)系统评价胰岛素抵抗,ELISA法检测大鼠血清chemerin的表达。结果与NC+ND组比较,IH+ND组大鼠FPG、FINS、IRI、TC、TG、LDL-C升高有统计学意义(P0.01);IH+HFD组大鼠血清FPG、TC、LDL-C水平高于IH+ND组,血清FINS、IRI水平高于NC+HFD组,差异均有统计学意义(P0.05)。与NC+ND组比较,IH+ND组大鼠血清chemerin水平升高有统计学意义(P0.01);IH+HFD组大鼠血清chemerin水平高于IH+ND组和NC+HFD组,差异均有统计学意义(P0.01)。Pearson分析显示:IH组大鼠血清chemerin与FPG(r=0.751,P0.01)、FINS(r=0.764,P0.01)、IRI(r=0.765,P0.01)、TC(r=0.791,P0.01)、LDL-C(r=0.818,P0.01)呈正相关,与ISI(r=-0.692,P0.01)呈负相关。结论间歇低氧大鼠存在血糖、血脂代谢紊乱,且间歇低氧合并高脂饮食时,大鼠糖脂代谢紊乱更为严重;间歇低氧大鼠血清chemerin水平有升高趋势,合并高脂饮食时这种趋势更为显著;血清chemerin水平变化与糖脂代谢紊乱相关,脂肪因子chemerin可作为OSAHS相关糖脂代谢紊乱的预测因子之一。     

间歇性低氧对兔血浆Lp-PLA2、IL-6和VCAM-1的影响

目的建立慢性间歇性低氧新西兰白兔模型,观察和评价间歇性低氧(IH)后对血浆中脂蛋白相关性磷脂酶A2(Lp-PLA2)、白细胞介素6(IL-6)和血管细胞黏附分子1(VCAM-1)的影响及动脉粥样硬化形成情况。方法采用随机对照、前瞻性动物实验和方差分析等方法,建立慢性间歇性低氧新西兰白兔模型。将36只4月龄新西兰大耳白兔随机分为两组:对照组和间歇性低氧组,按照低氧时间4、8、12周,又将对照组和间歇性低氧组各分3组。对照4、8、12周组,每组6只;间歇性低氧4、8、12周组,每组6只。间歇性低氧组置于缺氧舱中给予间歇低氧处理每天8 h。分别于第4周、第8周和第12周给实验兔称重,采静脉血,用ELISA方法检测Lp-PLA2、IL-6和VCAM-1含量,同时取腹主动脉利用HE染色观察动脉粥样硬化形成。结果 (1)间歇性低氧4周组、8周组和12周组两两比较及与对照组比较,血浆中Lp-PLA2、IL-6和VCAM-1表达水平差异有统计学意义(P0.05),间歇性低氧组与对照组间的差异随时间增加而增大,呈递增趋势,在12周时最明显。(2)对照4周组、8周组和12周组的血浆Lp-PLA2、IL-6和VCAM-1表达水平变化差异无统计学意义。(3)间歇性低氧组的Lp-PLA2、VCAM-1和IL-6血浆表达水平呈现明显正相关性。Lp-PLA2与VCAM-1的相关系数为0.75(P0.001)。Lp-PLA2与IL-6的相关系数为0.55,(P0.001)。VCAM-1与IL-6的相关系数为0.76(P0.001)。(4)间歇性低氧干预下腹主动脉组织HE染色后可观察到动脉粥样硬化的形成。结论慢性间歇性低氧可引起血浆Lp-PLA2、IL-6和VCAM-1水平增高,血浆中IL-6、VCAM-1及Lp-PLA2三者存在相关性,可推测间歇性低氧介导了内皮下炎症因子的聚集导致血管内皮的损伤,进而参与间歇性低氧后动脉粥样硬化的形成。     

胃旁路手术对高脂饮食诱导肥胖大鼠血浆ghrelin、GLP-1、PYY的影响

目的探讨胃旁路手术对高脂饮食诱导的肥胖大鼠血浆生长激素释放肽(ghrelin)、胰高血糖素样肽-1(GLP-1)、胃肠激素肽(PYY)的影响。方法将30只雄性Wistar大鼠随机分为正常饮食组(ND组)10只、高脂饮食组20只,分别给予正常饮食及高脂饮食喂养,喂养12周后,高脂饮食组成功建模肥胖大鼠16只,随机分为高脂饮食假手术组(HFD组)8只,高脂饮食+Roux-en-Y胃旁路手术(RYGB)组(HFD+RYGB组)8只,HFD+RYGB组大鼠行RYGB,ND组及HFD组行假手术。4周后处死全部大鼠,收集血样采用ELISA法测定血浆生长激素释放肽、胰高血糖素样肽-1、胃肠激素肽浓度。结果与ND组比较,HFD组大鼠体重增加,HFD+RYGB组大鼠体重低于HFD组,3组大鼠的摄食量比较差异无统计学意义;与ND组比较,HFD组大鼠空腹血糖与胰岛素水平升高,HFD+RYGB组大鼠空腹血糖与胰岛素水平较HFD组下降,但差异无统计学意义;HFD组大鼠血浆ghrelin、PYY浓度高于ND组,HFD+RYGB组大鼠血浆ghrelin、GLP-1浓度高于HFD组,PYY浓度低于HFD组,差异有统计学意义(P0.05)。结论肥胖大鼠RYGB术后体重减轻,血浆GLP-1、PYY、ghrelin循环水平改变。     

α-硫辛酸对高脂饮食肥胖小鼠术后空间学习记忆功能的影响

目的观察α-硫辛酸(α-LA)对高脂饮食(HFD)肥胖小鼠术后空间学习记忆功能的影响并探讨可能的机制。方法 120只雄性C57BL/6小鼠被分为6组(对照组,对照+手术组,对照+α-LA+手术组,HFD组,HFD+手术组,HFD+α-LA+手术组),每组20只。HFD干预组给予高脂饮食喂养12周,α-LA干预组给予α-LA灌胃12周,肝部分切除术后第1～5天行水迷宫。检测小鼠体质量,免疫荧光法检测海马casepase 3、Bcl-2表达情况,透射电镜观察海马神经元及突触结构。结果 HFD组比对照组体质量明显增加,HFD+手术组比对照+手术组体质量明显增加,HFD+α-LA+手术组术后空间学习记忆能力明显强于HFD+手术组(P0. 01)。HFD+α-LA+手术组术后第5天casepase 3、Bcl-2表达明显低于HFD+手术组,神经元及突触结构与HFD+手术组相比差异有统计学意义(P0. 01)。结论α-LA缓解了高脂饮食诱导的肥胖小鼠术后空间学习记忆功能下降程度,可能与抑制海马神经元凋亡,维持突触正常结构有关。     

11β-HSD1在糖皮质激素联合高脂喂养大鼠胰岛素抵抗中的作用

目的 通过糖皮质激素联合高脂喂养建立胰岛素抵抗动物模型,探讨11β-羟类固醇脱氢酶1(11β-HSD1)在该模型中的表达和意义.方法 32只雄性Wistar大鼠,按体重随机区组法分为对照组、地塞米松组、高脂饮食组、高脂+地塞米松组(HFD+ DEX组),每组8只.对照组和地塞米松组喂以普通饲料,高脂饮食组和HFD+ DEX组喂以高脂饲料,8周后地塞米松组和HFD+ DEX组辅以地塞米松刺激,12周后进行胰岛素耐量试验,检测血糖、血脂、血胰岛素及皮质酮水平,计算肝指数、内脏肥胖指数及稳态模型评估-胰岛素抵抗(HOMA-IR)指数,检测11β-HSD1基因及蛋白表达情况.结果 与对照组相比,其余3组均出现胰岛素抵抗,表现为:胰岛素耐量试验不敏感(注射胰岛素30 min后对照组、高脂饮食组、地塞米松组和HFD+ DEX组血糖值分别下降了44.15％,28.14％,32.58％,13.53％)、高血糖、高胰岛素血症、血脂紊乱(总胆固醇、甘油三酯及游离脂肪酸升高,高密度脂蛋白-胆固醇降低)、HOMA-IR指数、肝指数及内脏肥胖指数升高,且HFD+ DEX组各项指标变化幅度最大(F=10.89～213.20,P＜0.05或P＜0.01).另外,与对照组相比,其余3组内脏脂肪组织11β-HSD1基因及蛋白表达水平也明显升高,且HFD+ DEX组明显高于高脂饮食组及地塞米松组(F =32.64～116.00,P均＜0.01).结论 地塞米松联合高脂饮食喂养可成功建立大鼠胰岛素抵抗模型,内脏脂肪组织中11β-HSD1基因及蛋白表达升高,可能与胰岛素抵抗的发生密切相关.     

布拉氏酵母菌在非酒精性脂肪性肝病中的作用研究

目的探讨布拉氏酵母菌在高脂饮食诱导的大鼠非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)模型中的作用。方法 36只雄性SD大鼠随机分成4组,每组9只,1组:对照组;2组:高脂饮食组(82.5%普通饲料+10%猪油+2%胆固醇+0.5%胆酸钠+5%蛋黄粉);3组:布拉氏酵母菌组;4组:高脂饮食+布拉氏酵母菌组。每组分别于第4周、8周、12周处死3只大鼠,进行血清学检测和肝脏病理分析。结果第8周时高脂饮食组大鼠体质量明显大于对照组[(413.67±41.02)g vs(297.80±25.31)g,P0.05];高脂饮食组大鼠ALT、AST、TC、TG明显高于对照组(P0.05);高脂饮食+布拉氏酵母菌组大鼠体质量大于对照组,但小于高脂饮食组,差异有统计学意义(P0.05)。第12周时高脂饮食组大鼠肝脏指数明显大于对照组[(3.455±0.263)%vs(2.609±0.377)%,P0.05];高脂饮食组大鼠ALT、AST、TC、TG明显高于对照组(P0.05);高脂饮食+布拉氏酵母菌组大鼠ALT、AST、TC、TG低于高脂饮食组,差异有统计学意义(P0.05)。结论布拉氏酵母菌可改善NAFLD大鼠的血清学及肝脏脂肪变性。     

抗凋亡多肽Gly14-Humanin对动脉粥样硬化模型小鼠血小板高敏感性以及脂质斑块形成的作用

目的抗凋亡多肽Humanin可以延缓动脉粥样硬化脂质斑块形成,其机制可能是抑制氧化型低密度脂蛋白诱导的氧化性应激和内皮细胞凋亡,但Humanin对动脉粥样硬化状态下血小板高敏感性的影响尚无报道。本研究评价了Humanin衍生物([Gly14]-Humanin,HNG)对低密度脂蛋白受体(LDLR)敲除小鼠动脉粥样硬化形成以及血小板高敏感性的影响。方法将8周龄雄性野生型(wild type,WT)和低密度脂蛋白受体敲除小鼠进行实验分组,包括对照组(WT小鼠喂食普通饲料,CD组)、模型组(LDLR-/-小鼠喂食高脂饲料,HFD组)、实验组(LDLR-/-小鼠喂食高脂饲料的同时注射HNG,HFD+HNG组)。分别于4周、12周、24周,进行下腔静脉取血,分离洗涤血小板,进行血小板聚集实验并分离血清进行血脂含量的测量。适时分离主动脉进行苏丹IV染色,观察主动脉内表面粥样脂质斑块形成,利用Image-Pro Plus图像处理软件分析斑块面积大小。结果与对照组相比,喂食高脂饲料24周后,模型组小鼠主动脉内有大量粥样斑块形成,并且随着喂食高脂时间的延长,具有明显的脂蛋白水平的变化。模型组小鼠血小板在二磷酸腺苷(adenosine diphosphate,ADP)诱导下的聚集作用显著增强(P0.01),更重要的是,HFD+HNG组小鼠的斑块面积明显减小(P0.01),且血小板对ADP所诱导的血小板聚集明显低于HFD组(P0.01)。结论 HNG抑制动脉粥样硬化模型小鼠血小板高敏感性,可能是减缓动脉粥样硬化脂质斑块形成的机制之一。     

Liraglutide及PTEN在高脂饮食诱导的大鼠胰岛细胞凋亡中的作用

目的观察高脂饮食的SD大鼠胰腺第10号染色体同源丢失性磷酸酶-张力蛋白基因（PTEN）表达量的变化,以及liraglutide对胰岛细胞凋亡的作用。方法20只雄性SD大鼠随机分为3组：正常饮食（ND）组（n=6）、高脂饮食（HFD）组（n=6）和高脂饮食并给予liraglutide（HL）组（n=8）。ND组给予正常饮食,HFD组和HL组给予高脂饮食持续20周后行0GTT试验。随后ND组和HFD组给予生理盐水0．2mg／kg,HL组给予liraglutide0．2mg／kg,早晚各1次,持续4周,给药终点再次行OG-TT试验,评估β细胞功能。应用实时定量PCR检测各组大鼠胰腺PTENmRNA相对表达量,TUNEL染色观察大鼠胰岛细胞凋亡的变化。结果与ND组相比,HFD组和HL组大鼠体重增加（P〈0．05）,血TG和TC升高（P〈0．01）,OGTT中胰岛素曲线下面积（AUCIns）增大（P〈0．05或P〈0．01）,且胰腺PTENmRNA表达量增多（P〈0．05）。与HFD组相比,HL组体重、进食量和血TC下降（P〈0．05或P〈0．01）,OGTT中60min和120min时胰岛素和血糖降低（P〈O．01）,胰岛细胞凋亡减少,β细胞功能得到一定改善,但胰腺PTENmRNA表达量的差异无统计学意义（P〉0．05）。结论高脂饮食时SD大鼠胰腺PTENmRNA表达增加,liraglutide对高脂饮食大鼠胰腺PTENmRNA表达没有影响,但可能通过Akt信号通路减少其胰岛细胞凋亡。     

短链脂肪酸对高脂饮食诱导肥胖小鼠糖脂代谢紊乱的影响

目的探讨短链脂肪酸(SCFA)对高脂饮食(HFD)诱导的肥胖小鼠糖脂代谢紊乱的影响,并从肠上皮屏障功能角度初步探讨可能的作用机制。方法C57BL/6J小鼠40只,随机分为正常饲料对照组(ND)、高脂饮食模型组(HFD)、短链脂肪酸治疗组(HFD+SCFA)组、乳果糖(LA)治疗对照组(HFD+LA),每组10只,高脂饮食造模共14周,第11周开始给药,给药4周后取材。观察体质量、进食量、肝重、肝体比、附睾后脂肪组织脂肪细胞形态及直径;空腹葡萄糖(FBG),空腹血清胰岛素(FINS)及胰岛素抵抗指数(HOMA-IR);血清三酰甘油(TG)、总胆固醇(TC)、低密度脂蛋白(LDL-C);肝组织TG、血清ALT、AST,肝组织病理以及结肠组织病理改变。结果高脂饮食诱导肥胖小鼠给予SCFA干预4周后,体质量、肝重、肝体比、附睾后脂肪细胞直径、FBG、FSI、HOMA-IR、血清TG、血清TC较HFD组均显著降低(P0.01),且SCFA降低FSI、HOMA-IR、血清TG及TC的作用均优于LA(P0.01或P0.05);与HFD组相比,HFD+SCFA组小鼠肝组织TG含量、血清ALT、AST活性均显著降低(P0.01),肝组织脂肪变性、炎症以及气球样变有显著改善,肝脏活动度积分(NAS)显著降低(P0.01);SCFA干预可显著改善高脂饮食诱导的小鼠结肠上皮损伤、腺体排列紊乱、炎症细胞浸润等病理学改变。结论短链脂肪酸可有效降低高脂饮食诱导肥胖小鼠的体质量、改善血糖血脂代谢紊乱以及脂肪肝;降低肠道炎性反应,提高肠上皮屏障功能是可能的作用机制之一。     

ApoE~(-/-)小鼠动脉粥样硬化进程中microRNA-146a的表达变化

目的:观察ApoE~(-/-)小鼠动脉粥样硬化发生过程中microRNA-146a(miR-146a)的变化,探讨miR-146a与动脉粥样硬化之间的关系。方法:在ApoE~(-/-)小鼠中通过高脂高胆固醇喂饲构建动脉粥样硬化模型,分别在喂饲后第0周、4周、8周、12周、16周时采血和分离主动脉组织,通过HE染色和油红O染色观察主动脉组织的斑块形态,计算主动脉内膜/中膜比值和主动脉斑块的脂质含量;采用Real-Time PCR检测第0周、4周、8周、12周、16周时血浆和主动脉组织的miR-146a水平。结果:在高脂高胆固醇饲养后第8周时ApoE~(-/-)小鼠主动脉组织开始出现动脉粥样硬化,在第16周时主动脉粥样硬化最显著,16周时主动脉组织的内膜/中膜比值和主动脉斑块的脂质含量显著升高(P0.01);在动脉粥样硬化发生过程中,小鼠血浆和主动脉组织中的miR-146a水平均明显升高,其中血浆miR-146a的峰值出现在第8周(P0.01),之后血浆miR-146a逐渐下降;而主动脉组织的miR-146a水平从第4周开始升高(P0.05),逐渐上升至16周时达到峰值(P0.01);主动脉组织中miR-146a水平与ApoE~(-/-)小鼠主动脉粥样硬化呈强正相关性(r=0.892 5,P0.000 1)。结论:miR-146a可能参与了ApoE~(-/-)小鼠主动脉主动脉粥样硬化的发生。     

Drastic Dependence of the pH Sensitivity of Fe2O3-Bi2O3-B2O3 Hydrophobic Glasses with Composition

Fe₂O₃-Bi₂O₃-B₂O₃ (FeBiB) glasses were developed as novel pH responsive hydrophobic glasses. The influence of the glass composition on the pH sensitivity of FeBiB glasses was investigated. The pH sensitivity drastically decreased with decreasing B₂O₃ content. A moderate amount of Fe₂O₃ and a small amount of B₂O₃ respectively produces bulk electronic conduction and a pH response on glass surfaces. Because the remaining components of the glass can be selected freely, this discovery could prove very useful in developing novel pH glass electrodes that are self-cleaning and resist fouling.     

Synergistic Effects of Pr6O11 and Co3O4 on Electrical and Microstructure Features of ZnO-BaTiO3 Varistor Ceramics

This paper investigated the effects of Pr₆O₁₁ and Co₃O₄ on the electrical properties of ZnO-BaTiO₃ varistor ceramics. The Pr₆O₁₁ doping has a notable influence on the characteristics of the nonlinear coefficient, varistor voltage, and leakage current where the values varied from 2.29 to 2.69, 12.36 to 68.36 V/mm and 599.33 to 548.16 µA/cm², respectively. The nonlinear varistor coefficient of 5.50 to 7.15 and the varistor voltage of 7.38 to 8.10 V/mm was also influenced by the use of Co₃O₄ as a dopant. When the amount of Co₃O₄ was above 0.5 wt.%, the leakage current increased from 202.41 to 302.71 μA/cm². The varistor ceramics with 1.5 wt.% Pr₆O₁₁ shows good nonlinear electrical performance at higher breakdown voltage and reduced the leakage current of the ceramic materials. Besides, the varistor sample that was doped with 0.5 wt.% Co₃O₄ was able to enhance the nonlinear electrical properties at low breakdown voltage with a smaller value of leakage current.     

High-Temperature Chemical Stability of Cr(III) Oxide Refractories in the Presence of Calcium Aluminate Cement

Al₂O₃-CaO-Cr₂O₃ castables are used in various furnaces due to excellent corrosion resistance and sufficient early strength, but toxic Cr(VI) generation during service remains a concern. Here, we investigated the relative reactivity of analogous Cr(III) phases such as Cr₂O₃, (Al_1−xCr_x)₂O₃ and in situ Cr(III) solid solution with the calcium aluminate cement under an oxidizing atmosphere at various temperatures. The aim is to comprehend the relative Cr(VI) generation in the low-cement castables (Al₂O₃-CaO-Cr₂O₃-O₂ system) and achieve an environment-friendly application. The solid-state reactions and Cr(VI) formation were investigated using powder XRD, SEM, and leaching tests. Compared to Cr₂O₃, the stability of (Al_1−xCr_x)₂O₃ against CAC was much higher, which improved gradually with the concentration of Al₂O₃ in (Al_1−xCr_x)₂O₃. The substitution of Cr₂O₃ with (Al_1−xCr_x)₂O₃ in the Al₂O₃-CaO-Cr₂O₃ castables could completely inhibit the formation of Cr(VI) compound CaCrO₄ at 500–1100 °C and could drastically suppress Ca₄Al₆CrO₁₆ generation at 900 to 1300 °C. The Cr(VI) reduction amounting up to 98.1% could be achieved by replacing Cr₂O₃ with (Al_1−xCr_x)₂O₃ solid solution. However, in situ stabilized Cr(III) phases as a mixture of (Al_1−xCr_x)₂O₃ and Ca(Al_12−xCr_x)O₁₉ solid solution hardly reveal any reoxidation. Moreover, the CA₆ was much more stable than CA and CA₂, and it did not participate in any chemical reaction with (Al_1−xCr_x)₂O₃ solid solution.     

The Formation of Cr-Al Spinel under a Reductive Atmosphere

In the present work, for the first time, the possibility of formation of CrAl₂O₄ was shown from the equimolar mixture of co-precipitated Al₂O₃ and Cr₂O₃ oxides under a reductive environment. The crystallographic properties of the formed compound were calculated using the DICVOL procedure. It was determined that it has a cubic crystal structure with space group Fd-3m and a unit cell parameter equal to 8.22(3) Å. The formed CrAl₂O₄ is not stable under ambient conditions and easily undergoes oxidation to α-Al₂O₃ and α-Cr₂O₃. The overall sequence of the phase transformations of co-precipitated oxides leading to the formation of spinel structure is proposed.     

Maximum Achievable N Content in Atom-by-Atom Growth of Amorphous Si-B-C-N Materials

Amorphous Si-B-C-N alloys can combine exceptional oxidation resistance up to 1500 °C with high-temperature stability of superior functional properties. Because some of these characteristics require as high N content as possible, the maximum achievable N content in amorphous Si-B-C-N is examined by combining extensive ab initio molecular dynamics simulations with experimental data. The N content is limited by the formation of unbonded N₂ molecules, which depends on the composition (most intensive in C rich materials, medium in B rich materials, least intensive in Si-rich materials) and on the density (increasing N₂ formation with decreasing packing factor when the latter is below 0.28, at a higher slope of this increase at lower B content). The maximum content of N bonded in amorphous Si-B-C-N networks of lowest-energy densities is in the range from 34% to 57% (materials which can be grown without unbonded N₂) or at most from 42% to 57% (at a cost of affecting materials characteristics by unbonded N₂). The results are important for understanding the experimentally reported nitrogen contents, design of stable amorphous nitrides with optimized properties and pathways for their preparation, and identification of what is or is not possible to achieve in this field.     

Synthesis and Characterization of LaNi0.5Ti0.5O3 and La2NiTiO6 Double Perovskite Nanoparticles

In the present work, LaNi_0.5Ti_0.5O₃ and La₂NiTiO₆ nanoparticles were synthesized by the modified Pechini method. LaNi_0.5Ti_0.5O₃ was calcined at 1073 K for 17 h or 100 h, while La₂NiTiO₆ was calcined at 1273 K for 135 h. The double perovskite calcined at 1073 K for 17 h presented orthorhombic symmetry with Pbnm space group, mean particle size was 31.9 ± 1 nm, random ordering of Ni²⁺ and Ti⁴⁺ cations, Néel temperature close to 15 K, and magnetic moment of 1.29 μB. By increasing the calcination time, this material showed the same symmetry and space group, a mean particle size of 50.7 ± 2 nm, short-range ordering of Ni²⁺ and Ti⁴⁺ cations, Néel temperature around 12 K, and magnetic moment of 0.96 μB. La₂NiTiO₆ presented a monoclinic crystal structure, with P2₁/n space group, mean particle size of 80.0 ± 5 nm, rock salt ordering of Ni²⁺ and Ti⁴⁺, Néel temperature of approximately 23 K, and magnetic moment of 2.75 μB.     

Hydrolytic Modification of SiO2 Microspheres with Na2SiO3 and the Performance of Supported Nano-TiO2 Composite Photocatalyst

Modified microspheres (SiO₂-M) were obtained by the hydrolytic modification of silicon dioxide (SiO₂) microspheres with Na₂SiO₃, and then, SiO₂-M was used as a carrier to prepare a composite photocatalyst (SiO₂-M/TiO₂) using the sol-gel method; i.e., nano-TiO₂ was loaded on the surface of SiO₂-M. The structure, morphology, and photocatalytic properties of SiO₂-M/TiO₂ were investigated. Besides, the mechanism of the effect of SiO₂-M was also explored. The results show that the hydrolytic modification of Na₂SiO₃ coated the surface of SiO₂ microspheres with an amorphous SiO₂ shell layer and increased the quantity of hydroxyl groups. The photocatalytic performance of the composite photocatalyst was slightly better than that of pure nano-TiO₂ and significantly better than that of the composite photocatalyst supported by unmodified SiO₂. Thus, increasing the loading capacity of nano-TiO₂, improving the dispersion of TiO_2, and increasing the active surface sites are essential factors for improving the functional efficiency of nano-TiO₂. This work provides a new concept for the design of composite photocatalysts by optimizing the performance of the carrier.     

Photo-Charging of Li(Ni0.65Co0.15Mn0.20)O2 Lithium-Ion Battery Using Silicon Solar Cells

This study reports an integrated device in which a lithium-ion battery (LIB) and Si solar cells are interconnected. The LIB is fabricated using the Li(Ni_0.65Co_0.15Mn_0.20)O₂ (NCM622) cathode and the Li₄Ti₅O₁₂ (LTO) anode. The surface and shape morphologies of the NCM and LTO powders were investigated by field emission scanning electron microscopy (FE-SEM). In addition, the structural properties were thoroughly examined by X-ray diffraction (XRD). Further, their electrochemical characterization was carried out on a potentiostat. The specific discharge capacity of the NCM cathode (half-cell) was 188.09 mAh/g at 0.1 C current density. In further experiments, the NCM-LTO full-cell has also shown an excellent specific capacity of 160 mAh/g at a high current density of 1 C. Additionally, the capacity retention was outstanding, with 99.63% at 1 C after 50 cycles. Moreover, to meet the charging voltage requirements of the NCM-LTO full-cell, six Si solar cells were connected in series. The open-circuit voltage (V_OC) and the short-circuit photocurrent density (J_SC) for the Si solar cells were 3.37 V and 5.42 mA/cm². The calculated fill factor (FF) and efficiency for the Si solar cells were 0.796 and 14.54%, respectively. Lastly, the integrated device has delivered a very high-power conversion-storage efficiency of 7.95%.     

Atomic Layer Deposition of Ultrathin La2O3/Al2O3 Nanolaminates on MoS2 with Ultraviolet Ozone Treatment

Due to the chemically inert surface of MoS₂, uniform deposition of ultrathin high-κ dielectric using atomic layer deposition (ALD) is difficult. However, this is crucial for the fabrication of field-effect transistors (FETs). In this work, the atomic layer deposition growth of sub-5 nm La₂O₃/Al₂O₃ nanolaminates on MoS₂ using different oxidants (H₂O and O₃) was investigated. To improve the deposition, the effects of ultraviolet ozone treatment on MoS₂ surface are also evaluated. It is found that the physical properties and electrical characteristics of La₂O₃/Al₂O₃ nanolaminates change greatly for different oxidants and treatment processes. These changes are found to be associated with the residual of metal carbide caused by the insufficient interface reactions. Ultraviolet ozone pretreatment can substantially improve the initial growth of sub-5 nm H₂O-based or O₃-based La₂O₃/Al₂O₃ nanolaminates, resulting in a reduction of residual metal carbide. All results indicate that O₃-based La₂O₃/Al₂O₃ nanolaminates on MoS₂ with ultraviolet ozone treatment yielded good electrical performance with low leakage current and no leakage dot, revealing a straightforward approach for realizing sub-5 nm uniform La₂O₃/Al₂O₃ nanolaminates on MoS₂.     

Pilot-Scale Studies of WO3/S-Doped g-C3N4 Heterojunction toward Photocatalytic NOx Removal

Due to the rising concentration of toxic nitrogen oxides (NO_x) in the air, effective methods of NO_x removal have been extensively studied recently. In the present study, the first developed WO₃/S-doped g-C₃N₄ nanocomposite was synthesized using a facile method to remove NOx in air efficiently. The photocatalytic tests performed in a newly designed continuous-flow photoreactor with an LED array and online monitored NO₂ and NO system allowed the investigation of photocatalyst layers at the pilot scale. The WO₃/S-doped-g-C₃N₄ nanocomposite, as well as single components, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller surface area analysis (BET), X-ray fluorescence spectroscopy (XRF), X-ray photoemission spectroscopy method (XPS), UV–vis diffuse reflectance spectroscopy (DR/UV–vis), and photoluminescence spectroscopy with charge carriers’ lifetime measurements. All materials exhibited high efficiency in photocatalytic NO₂ conversion, and 100% was reached in less than 5 min of illumination under simulated solar light. The effect of process parameters in the experimental setup together with WO₃/S-doped g-C₃N₄ photocatalysts was studied in detail. Finally, the stability of the composite was tested in five subsequent cycles of photocatalytic degradation. The WO₃/S-doped g-C₃N₄ was stable in time and did not undergo deactivation due to the blocking of active sites on the photocatalyst’s surface.