介孔La_(1-x)Sr_(x)MnO_(3)催化剂的COK-12纳米浇铸法制备

钙钛矿型催化剂在汽车尾气净化方面具有良好的应用潜力。本文以表面活性剂P123为软模板剂,廉价的硅酸钠为硅源,在近中性条件下制备了介孔材料COK-12。并以此为基础,以对二甲苯为扩容剂对COK-12进行改性,得到了大孔径、有序的介孔材料。随后以改性介孔材料为模板剂,采用纳米浇铸法结合溶胶-凝胶法制备了介孔La_(0.8)Sr_(0.2)MnO_(3)催化剂。结果显示,在550℃下合成的催化剂具有较大的比表面积(72.11 m^(2)/g),表面Mn^(4+)/Mn^(3+)和O_(ads)/O_(lat)摩尔比最高。此外,样品的CO催化性能测试转化表明,550℃下合成的样品具有最好的催化活性和优秀的高温稳定性,其特征温度T_(50)和T_(90)分别为180和218℃。

NoV GⅡ.2亚型RT-RPA-CRISPR/Cas12a检测方法的建立

近年来,一种新的诺如病毒GⅡ.2亚型(norovirus GⅡ.2,NoV GⅡ.2)通过牡蛎等生食海鲜感染人群,引发急性胃肠炎,并在全球广泛传播。为实现NoV感染的现场诊断和快速疫情响应,亟需建立快速便捷的NoV GⅡ.2亚型核酸检测方法。本研究通过设计引物、crRNA,经优化反应条件后,建立了NoV GⅡ.2亚型RTRPA-CRISPR/Cas12a检测方法。结果显示:利用引物NoV-GⅡ.2-F1B和NoV-GⅡ.2-R1对NoV GⅡ.2标准RNA进行RT-RPA扩增,结合crRNA1介导的CRISPR/Cas12a报告体系,能在40 min内完成NoV GⅡ.2核酸检测;该方法检测灵敏度为10 copies/μL,且与轮状病毒、腺病毒、星形病毒、人副肠孤病毒、博卡病毒和札如病毒无交叉反应;应用该方法和qRT-PCR法,分别对30份临床模拟样本进行检测,发现总符合率达96.67%。结果表明,本研究建立的NoV GⅡ.2亚型RT-RPA-CRISPR/Cas12a检测方法无需依赖昂贵设备,具有灵敏度高、特异性强、操作便捷快速等特点,为NoV GⅡ.2感染的现场检测和防控提供了新方法。

Engineering of oxygen vacancy and bismuth cluster assisted ultrathin Bi_(12)O_(17)Cl_(2)nanosheets with efficient and selective photoreduction of CO_(2)to CO

The photocatalytic conversion of CO_(2)into solar‐powered fuels is viewed as a forward‐looking strategy to address energy scarcity and global warming.This work demonstrated the selective photoreduction of CO_(2)to CO using ultrathin Bi_(12)O_(17)Cl_(2)nanosheets decorated with hydrothermally synthesized bismuth clusters and oxygen vacancies(OVs).The characterizations revealed that the coexistences of OVs and Bi clusters generated in situ contributed to the high efficiency of CO_(2)–CO conversion(64.3μmol g^(−1)h^(−1))and perfect selectivity.The OVs on the facet(001)of the ultrathin Bi_(12)O_(17)Cl_(2)nanosheets serve as sites for CO_(2)adsorption and activation sites,capturing photoexcited electrons and prolonging light absorption due to defect states.In addition,the Bi‐cluster generated in situ offers the ability to trap holes and the surface plasmonic resonance effect.This study offers great potential for the construction of semiconductor hybrids as multiphotocatalysts,capable of being used for the elimination and conversion of CO_(2)in terms of energy and environment.

烧结助剂ZnO对Li_(6.5)La_(3)Zr_(1.5)Nb_(0.5)O_(12)固态电解质离子电导率及循环稳定性的影响

采用固相合成法制备Li_(6.5)La_(3)Zr_(1.5)Nb_(0.5)O_(12)(简称LLZNO)固态电解质,分析了质量分数为0.00%~2.00%的ZnO对LLZNO离子电导率和循环稳定性的影响。采用X射线衍射仪、扫描电子显微镜、电化学阻抗谱以及恒流充放电测试,探究了样品的晶体结构、断面形貌、离子电导率及其对锂循环稳定性。结果表明:随着样品中ZnO质量分数的增加,样品烧结气孔数量明显减少,断面形貌平整。当ZnO的质量分数为0.50%时,样品为立方相,室温离子电导率提升了14.63%;在80h(40次)的恒流充放电循环中,电压保持稳定,具有良好的循环性能。

Evaluating serum CXCL12,sCD22,Lp-PLA2 levels and ratios as biomarkers for diagnosis of Alzheimer's disease

BACKGROUND Grasping the underlying mechanisms of Alzheimer's disease(AD)is still a work in progress,and existing diagnostic techniques encounter various obstacles.Therefore,the discovery of dependable biomarkers is essential for early detection,tracking the disease's advancement,and steering treatment strategies.AIM To explore the diagnostic potential of serum CXCL12,sCD22,Lp-PLA2,and their ratios in AD,aiming to enhance early detection and inform targeted treatment strategies.METHODS The study was conducted in Dongying people's Hospital from January 2021 to December 2022.Participants included 60 AD patients(AD group)and 60 healthy people(control group).Using a prospective case-control design,the levels of CXCL12,sCD22 and Lp-PLA2 and their ratios were detected by enzyme-linked immunosorbent assay kit in the diagnosis of AD.The differences between the two groups were analyzed by statistical methods,and the corresponding ratio was constructed to improve the specificity and sensitivity of diagnosis.RESULTS Serum CXCL12 levels were higher in the AD group(47.2±8.5 ng/mL)than the control group(32.8±5.7 ng/mL,P<0.001),while sCD22 levels were lower(14.3±2.1 ng/mL vs 18.9±3.4 ng/mL,P<0.01).Lp-PLA2 levels were also higher in the AD group(112.5±20.6 ng/mL vs 89.7±15.2 ng/mL,P<0.05).Significant differences were noted in CXCL12/sCD22(3.3 vs 1.7,P<0.001)and Lp-PLA-2/sCD22 ratios(8.0 vs 5.2,P<0.05)between the groups.Receiver operating characteristic analysis confirmed high sensitivity and specificity of these markers and their ratios in distinguishing AD,with area under the curves ranging from CONCLUSION Serum CXCL12 and Lp-PLA2 levels were significantly increased,while sCD22 were significantly decreased,as well as increases in the ratios of CXCL12/sCD22 and Lp-PLA2/sCD22,are closely related to the onset of AD.These biomarkers and their ratios can be used as potential diagnostic indicators for AD,providing an important clinical reference for early intervention and treatment.

Preparation and magnetic hardening of low Ti content(Sm,Zr)(Fe,Co,Ti)_(12) magnets by rapid solidification non-equilibrium method

The Sm–Zr–Fe–Co–Ti quinary-alloys with ThMn12 structure has attracted wide attention for ultra-high intrinsic magnetic properties,showing potentiality to be developed into rare-earth permanent magnets.The Ti element in alloys is crucial for phase stability and magnetic properties,and lower Ti content can increase intrinsic magnetic properties but reduce phase stability.In this study,the 1:12 single-phase melt-spun ribbons with low Ti content was successfully prepared using a rapid solidification non-equilibrium method for the Sm1.1Zr_(0.2)Fe_(9.2)Co_(2.3)Ti_(0.5) quinary-alloy.However,this non-equilibrium ribbon did not achieve good magnetic hardening due to the uneven microstructure and microstrain.Then,annealing was carried out to eliminate micro-strain and homogenize microstructure,therefore,remanence and coercivity were significantly improved even the precipitation of a small amount of a-Fe phase which were not conducive to coercivity.The remanence of 86.1 emu/g and coercivity of 151 kA/m was achieved when annealing at 850℃ for 45 min.After hot pressing,under the action of high temperature and pressure,a small portion of ThMn12 phases in the magnet decompose into Sm-rich phases and a-Fe,while remanence of 4.02 kGs(1 Gs=10^(-4) T),and coercivity of 1.12 kOe(1 Oe=79.5775 A·m^(-1))were still acquired.Our findings can provide reference for exploring practical permanent magnets made of 1:12 type quinary-alloys.

Phospholipase A2 enzymes PLA2G2A and PLA2G12B as potential diagnostic and prognostic biomarkers in cholangiocarcinoma

BACKGROUND Phospholipase A2(PLA2)enzymes are pivotal in various biological processes,such as lipid mediator production,membrane remodeling,bioenergetics,and maintaining the body surface barrier.Notably,these enzymes play a significant role in the development of diverse tumors.AIM To systematically and comprehensively explore the expression of the PLA2 family genes and their potential implications in cholangiocarcinoma(CCA).METHODS We conducted an analysis of five CCA datasets from The Cancer Genome Atlas and the Gene Expression Omnibus.The study identified differentially expressed genes between tumor tissues and adjacent normal tissues,with a focus on PLA2G2A and PLA2G12B.Gene Set Enrichment Analysis was utilized to pinpoint associated pathways.Moreover,relevant hub genes and microRNAs for PLA2G2A and PLA2G12B were predicted,and their correlation with the prognosis of CCA was evaluated.RESULTS PLA2G2A and PLA2G12B were discerned as differentially expressed in CCA,manifesting significant variations in expression levels in urine and serum between CCA patients and healthy individuals.Elevated expression of PLA2G2A was correlated with poorer overall survival in CCA patients.Additionally,the study delineated pathways and miRNAs associated with these genes.CONCLUSION Our findings suggest that PLA2G2A and PLA2G12B may serve as novel potential diagnostic and prognostic markers for CCA.The increased levels of these genes in biological fluids could be employed as non-invasive markers for CCA,and their expression levels are indicative of prognosis,underscoring their potential utility in clinical settings.

Neuroprotective effects of Shaoyao Gancao decoction against excitatory damage in PC12 cells based on the Src-NR2-nNOS pathway

Objective:To explore the neuroprotective effects of the Shaoyao Gancao decoction(SGD)against excitatory damage in PC12 cells and the role of the Src-NR2-nNOS pathway mediation by SGD in regulatingγ-aminobutyric acid(GABA)-glutamate(Glu)homeostasis.Methods: N-Methyl-d-aspartic acid(NMDA)was used to establish a PC12 cell excitability injury model.To investigate the neuroprotective effect of SGD,a cell counting kit-8(CCK-8)assay was used to determine PC12 cell viability,Annexin V/Propidium Iodide(Annexin V/PI)double staining was used to determine PC12 cell apoptosis,and Ca^(2+)concentration was observed using laser confocal microscopy.GABA receptor agonists and antagonists were used to analyze the neuroprotective interactions betweenγ-aminobutyric acid(GABA)and NMDA receptors.Additionally,molecular biology techniques were used to determine mRNA and protein expression in the Src-NR2-nNOS pathway.We analyzed the correlations between the regulatory sites of GABA and NMDA interactions,excitatory neurotoxicity,and brain damage at the molecular level.Results: NMDA excitotoxic injury manifested as a significant decrease in cell activity,increased apoptosis and caspase-3 protein expression,and a significant increase in intracellular Ca^(2+)concentration.Administration of SGD,a GABAA receptor agonist(muscimol),or a GABAB receptor agonist(baclofen)decreased intracellular Ca^(2+)concentrations,attenuated apoptosis,and reversed NMDA-induced upregulation of caspase-3,Src,NMDAR2A,NMDAR2B,and nNOS.Unexpectedly,a GABA_(A)receptor antagonist(bicuculline)and a GABA_(B)receptor antagonist(saclofen)failed to significantly increase excitatory neurotoxicity.Conclusions: Taken together,these results not only provide an experimental basis for SGD administration in the clinical treatment of central nervous system injury diseases,but also suggest that the Src-NR2A-nNOS pathway may be a valuable target in excitotoxicity treatment.

Clinical significance of upregulated Rho GTPase activating protein 12 causing resistance to tyrosine kinase inhibitors in hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is a major health challenge with high incidence and poor survival rates in China.Systemic therapies,particularly tyrosine kinase inhibitors(TKIs),are the first-line treatment for advanced HCC,but resistance is common.The Rho GTPase family member Rho GTPase activating protein 12(ARHGAP12),which regulates cell adhesion and invasion,is a potential therapeutic target for overcoming TKI resistance in HCC.However,no studies on the expression of ARHGAP12 in HCC and its role in resistance to TKIs have been reported.AIM To unveil the expression of ARHGAP12 in HCC,its role in TKI resistance and its potential associated pathways.METHODS This study used single-cell RNA sequencing(scRNA-seq)to evaluate ARHGAP12 mRNA levels and explored its mechanisms through enrichment analysis.CellChat was used to investigate focal adhesion(FA)pathway regulation.We integrated bulk RNA data(RNA-seq and microarray),immunohistochemistry and proteomics to analyze ARHGAP12 mRNA and protein levels,correlating with clinical outcomes.We assessed ARHGAP12 expression in TKI-resistant HCC,integrated conventional HCC to explore its mechanism,identified intersecting FA pathway genes with scRNA-seq data and evaluated its response to TKI and immunotherapy.RESULTS ARHGAP12 mRNA was found to be highly expressed in malignant hepatocytes and to regulate FA.In malignant hepatocytes in high-score FA groups,MDK-[integrin alpha 6(ITGA6)+integrinβ-1(ITGB1)]showed specificity in ligand-receptor interactions.ARHGAP12 mRNA and protein were upregulated in bulk RNA,immunohistochemistry and proteomics,and higher expression was associated with a worse prognosis.ARHGAP12 was also found to be a TKI resistance gene that regulated the FA pathway.ITGB1 was identified as a crossover gene in the FA pathway in both scRNA-seq and bulk RNA.High expression of ARHGAP12 was associated with adverse reactions to sorafenib,cabozantinib and regorafenib,but not to immunotherapy.CONCLUSION ARHGAP12 expression is elevated in HCC and TKI-resistant HCC,and its regulatory role in FA may underlie the TKI-resistant phenotype.

Vitamin B12 deficiency in dialysis patients:risk factors,diagnosis,complications,and treatment:A comprehensive review

Vitamin B12 deficiency is a significant concern among patients with end-stage renal disease undergoing dialysis.However,there hasn’t been extensive research conducted on this particular patient group.The reported incidence rates vary widely,ranging from 20%to 90%,reflecting the complexity of its diagnosis.Dialysis patients often face multiple nutritional deficiencies,including a lack of essential vitamins,due to factors such as dietary restrictions,impaired absorption,and nutrient loss during dialysis.Diagnosing vitamin B12 deficiency in these patients is challenging,and addressing it is crucial to prevent complications and improve their overall quality of life.This review paper delves into the available body of evidence on vitamin B12 deficiency in dialysis patients,examining the contributing risk factors,diagnostic challenges,potential complications,and available treatment options.It provides a well-rounded perspective on the topic,making it a valuable resource for researchers,healthcare practitioners,and policymakers interested in addressing the nutritional needs of dialysis patients.

c-Myc、CDK12在胃癌组织中的表达及临床意义

目的 探讨胃癌组织中c-Myc、细胞周期蛋白依赖性激酶12(CDK12)表达及其与患者临床特征及预后的关系。方法 收集80例胃癌患者的胃癌组织和癌旁组织标本,采用免疫组化法检测标本中的c-Myc、CDK12表达水平。比较胃癌组织和癌旁组织中c-Myc、CDK12阳性表达情况;分析胃癌组织中c-Myc、CDK12阳性表达与患者临床病理特征的关系;分析c-Myc与CDK12阳性表达的相关性,胃癌组织中c-Myc、CDK12阳性表达与胃癌患者预后的关系。结果 胃癌组织中c-Myc、CDK12阳性表达率(77.5%、87.5%)均明显高于癌旁组织(13.8%、15.0%)(P<0.05)。不同年龄、性别、肿瘤最大直径患者胃癌组织中c-Myc、CDK12阳性表达率比较差异无统计学意义(P>0.05);中低分化、Ⅲ~Ⅳ期、侵犯浆膜、有淋巴结转移患者胃癌组织中c-Myc和CDK12阳性表达率分别为88.0%、87.0%、88.9%、90.0%和94.0%、92.6%、97.2%、100.0%,均明显高于高分化、Ⅰ~Ⅱ期、未侵犯浆膜、无淋巴结转移患者胃癌组织的60.0%、57.7%、68.2%、70.0%和76.7%、76.9%、79.5%、80.0%(P<0.05)。相关分析发现,c-Myc、CDK12在胃癌组织中的表达呈正相关性(r=0.487,P=0.016<0.05)。胃癌组织中c-Myc、CDK12阳性患者的3年生存率分别为19.4%、21.4%,均明显低于c-Myc、CDK12阴性患者的55.6%、70.0%(P<0.05)。结论 c-Myc、CDK12在胃癌组织中异常高表达,两者呈正相关性,并与肿瘤的TNM分期、分化程度、肿瘤侵袭深度及淋巴结转移有关,对患者的预后有明显影响,通过检测两者水平可能评估胃癌患者的预后。

马铃薯新品种春薯12号的选育

春薯12号是以78-11-7为母本,以冀张薯8号为父本,通过系统选育而成的鲜食、淀粉加工兼用型马铃薯新品种。中晚熟,生育期89 d(天)左右,植株直立,平均株高65 cm;块茎卵圆形,大而整齐,表皮略麻,芽眼稀少,薯皮黄色,薯肉浅黄色,商品薯率较高,干物质含量24.95%,淀粉含量19.30%,粗蛋白含量1.66%,耐贮藏、运输,抗马铃薯X病毒(PVX)和马铃薯Y病毒(PVY),每667 m^(2)产量3000 kg左右,适宜吉林、黑龙江和内蒙古东部地区春季种植。

2014-2018年江苏省人源喹诺酮耐药1,4,[5],12:i:-沙门氏菌的基因组学初步分析

目的分析江苏省喹诺酮耐药1,4,[5],12:i:-沙门氏菌分子流行病学特征。方法用cgMLST分析江苏省及欧美来源菌株的分子流行病学特征,并初步分析喹诺酮耐药1,4,[5],12:i:-沙门氏菌可能的传播特征。结果13株喹诺酮耐药1,4,[5],12:i:-沙门氏菌共注释11大类抗性基因(Antibiotic resistance genes,ARGs)。其中氨基糖苷类ARGs检出率最高(100%);12株喹诺酮耐药菌株(92.3%)均携带IncHI2/IncHI2A质粒类型;不同国家/地区来源菌株质粒介导喹诺酮耐药(PMQR)基因携带分析显示美国及欧洲来源菌株携带6类PMQR基因,qnrB19检出率最高。江苏省来源菌株携带3类PMQR基因类型,aac(6′)-Ib-cr检出率最高(11.84%);不同国家/地区来源菌株cgMLST位点差异分析显示形成3个主要流行谱系。结论江苏省人源喹诺酮耐药1,4,[5],12:i:-沙门氏菌分离株与欧美菌株可能具有共同进化来源,PMQR基因携带水平存在国家/地区差异。

雌雄同株工业大麻新品种云麻12号的选育

云麻12号是云南省农业科学院经济作物研究所于2023年选育的雌雄同株晚熟型工业大麻新品种。该品种THC平均含量为0.07%,CBD平均含量为2.58%。2020—2021年参加全省区域试验,花叶平均产量2785.8 kg/hm^(2),较对照品种云麻8号增产24.68%;麻籽平均产量1959.15 kg/hm^(2),较对照增产14.00%;麻糠平均产量1921.05 kg/hm^(2),较对照增产12.33%。该品种具有较强的抗病性、抗旱性和抗倒伏性,是适合低纬地区种植的一个雌雄同株工业大麻多用型新品种。

妊娠期糖尿病患者血清Xenin-25、CTRP12水平及对妊娠结局的影响

目的分析妊娠期糖尿病(GDM)患者血清神经降压素相关肽(Xenin-25)、C1q肿瘤坏死因子相关蛋白12(CTRP12)与妊娠结局的关系。方法选取2021年2月—2022年2月川北医学院附属医院生殖医学科诊治的GDM患者92例为GDM组,再根据是否发生不良妊娠结局,分为预后不良亚组(n=34)和预后良好亚组(n=58)。以同期健康妊娠妇女50例为正常妊娠组。采用酶联免疫吸附法检测血清Xenin-25、CTRP12水平;Pearson相关性分析血清Xenin-25、CTRP12与糖代谢指标的相关性;多因素Logistic回归分析影响GDM患者不良妊娠结局的因素;受试者工作特征曲线评价血清Xenin-25、CTRP12对妊娠结局的预测价值。结果GDM组血清Xenin-25、CTRP12低于正常妊娠组,而空腹血糖(FPG)、糖化血红蛋白(HbA_(1c))、空腹胰岛素(FINS)及稳态模型评估的胰岛素抵抗指数(HOMA-IR)水平均高于正常妊娠组(t/P=16.046/<0.001,22.114/<0.001,11.510/<0.001,13.666/<0.001,12.101/<0.001,14.413/<0.001);GDM组血清Xenin-25、CTRP12表达与FPG、FINS、HbA_(1c)及HOMA-IR呈显著负相关(Xenin-25:r/P=-0.665/<0.001,-0.598/<0.001,-0.567/<0.001,-0.702/<0.001;CTRP12:r/P=-0.579/<0.001,-0.622/<0.001,-0.667/<0.001,-0.725/<0.001);预后不良亚组血清Xenin-25、CTRP12低于预后良好亚组,HOMA-IR高于预后良好亚组(t/P=6.783/<0.001,17.997/<0.001,15.146/<0.001);血清CTRP12升高、Xenin-25升高是影响GDM患者不良妊娠结局的独立保护因素[OR(95%CI)=0.646(0.499~0.837),0.619(0.465~0.824)],HOMA-IR升高是危险因素[OR(95%CI)=1.353(1.110~1.649)]。血清Xenin-25、CTRP12及二者联合预测GDM患者不良妊娠结局的AUC分别为0.828、0.815、0.870,二者联合优于各自单独预测效能(Z=4.113、4.327,P=0.003、0.001)。结论GDM孕妇血清Xenin-25、CTRP12水平降低,均参与GDM的疾病过程,二者联合对GDM患者不良妊娠结局具有较高的评估价值。

叶酸联合维生素B_(12)治疗伴高同型半胱氨酸血症的勃起功能障碍患者的效果

目的探究叶酸联合维生素B_(12)治疗伴高同型半胱氨酸血症(HHcy)的勃起功能障碍(ED)患者的效果。方法选择2021年6月至2022年8月于新乡医学院第一附属医院门诊确诊的61例伴有HHcy的ED患者,按照患者意愿分为观察组及对照组。最终观察组入组37例,对照组入组22例。观察组口服叶酸片及维生素B_(12)片;对照组无药物干预。分别测定两组治疗前和治疗12周后的血浆同型半胱氨酸(Hcy)、维生素B_(12)、叶酸水平,使用国际勃起功能评分量表(IIEF-5)评定勃起功能状态。结果治疗前后,对照组血浆Hcy、叶酸、维生素B_(12)水平及IIEF-5评分比较差异无统计学意义(P>0.05);治疗后观察组血浆叶酸、维生素B_(12)水平及IIEF-5评分升高,且高于对照组(P<0.01),血浆Hcy水平下降,且低于对照组(P<0.01)。结论叶酸联合维生素B_(12)治疗方案可以降低伴HHcy的ED患者的血浆Hcy水平,改善勃起功能。

基于维生素B_(12)的引湿性研究谈国家药品标准物质的管理方法

目的:基于维生素B_(12)的引湿性研究,探讨有引湿性化学对照品的管理方法,进一步完善和提高国家药品标准物质的管理工作。方法:采用动态水分吸附法(DVS)分析维生素B_(12)对照品的引湿性;基于分析结果,从各个环节探讨有引湿性的国家药品标准物质的管理。结果:湿度在RH 20%~80%变化时,维生素B_(12)的水分吸附不断上升,引湿性明显。样品在RH 20%环境失重1.4%,在RH 50%环境时,样本质量变化显著增加至1.3%。进一步对该批对照品进行应用区域RH 25%~45%的DVS分析,结果RH25%时,样品失重0.7%;RH 45%时,样品增重0.56%。故建议维生素B_(12)对照品应在RH 30%~40%的环境中快速称量。结论:对于有引湿性的化学对照品,应在原料筛选、分装、包装、标签和说明书、稳定性考察等环节针对其特性制定相应的管理方法,以全面提升国家药品标准物质的管理和质量,为药品质量标准的实施和用药安全提供保障。

试论美国K-12公立学校课程中的种族批判理论之争

近年来,种族批判理论开始走进美国K-12公立学校课程,成为培育学生社会情感能力、维护教育公平的一种路径。然而,伴随种族矛盾加剧和民粹主义抬头,美国社会围绕种族批判理论在K-12公立学校课程中的存废问题展开激烈争论。反对者指责该理论妨害学生的种族身份认知,曲解美国历史,破坏社会共识;支持者则认为该理论能够提升学生多元文化意识,增强种族和历史问题的课堂对话。这场以种族批判理论为核心的课程博弈,反映了当前美国两党在公共教育领域对意识形态主导权的竞争。美国K-12公立学校需要认清既有课程治理措施的缺失,及时清除影响课程设置的认知偏见,进一步拓展具有文化相关性的课程空间。

[(H_(3)DIBA)_(2)Cl]·[HGeMo_(12)O_(40)]的合成、表征、光催化和电化学性质

利用水热法合成了一种新的基于Keggin型杂多酸的无机-有机杂化物[(H_(3)DIBA)_(2)Cl]·[HGeMo_(12)O_(40)],(HDIBA=3,5-二(1H--咪唑-1-基)苯甲酸).单晶X-射线衍射测试表明,该化合物为三斜晶系,P-1空间群,a=1.27831(4)nm,b=1.29723(4)nm,c=1.98978(5)nm;α=94.51°,β=102.61°,γ=117.99°,V=2.77968(14)nm 3,Z=2.结构研究表明,在该化合物中HDIBA被质子化,配体与游离的Cl-之间通过氢键相互作用形成了一维超分子链状结构,Keggin型[GeMo_(12)O_(40)]^(4-)多酸阴离子与[H_(3)DIBA]^(2+)之间通过氢键作用将相邻的一维超分子链连接形成三维超分子结构.该化合物可以光催化降解有机染料孔雀石绿,150 min内降解率达到99.99%;另外,该化合物具有电催化还原BrO_(3)^(-)和电催化氧化抗坏血酸(AA)的性质.总之,该化合物可以作为一种有效处理废水中污染物的异相光、电催化剂.

石榴石型立方相Li_(7)La_(3)Zr_(2)O_(12)固态电解质的制备及储锂性能

石榴石型立方相Li_(7)La_(3)Zr_(2)O_(12)(LLZO)具有高的离子电导率和热稳定性,在固态锂电池领域颇具应用前景。煅烧温度对制备高性能立方相LLZO至关重要。为此,首先采用不同煅烧温度(1050℃、1100℃、1150℃、1200℃、1250℃)制备了LLZO,然后将10%磺酸甜菜碱改性的聚偏二氟乙烯(SB-PVDF)与90%LLZO复合制备固态电解质膜,并研究其电化学储锂性能。结果表明:在最优煅烧温度1200℃时制备的LLZO为纯立方相结构,相对致密度高达92.4%,离子电导率为1.21×10^(-4)S/cm,活化能为0.335eV,相应的固态锂电池在1.0C充放电时的放电比容量为124.3mAh/g,循环200圈后容量保持率为93.4%,优于其他样品。