Enhanced generation of reactive oxygen species and photocatalytic activity by Pt-based metallic nanostructures: the composition matters

The modification of semiconductor nanostructures with metallic nanocomponents can promote the separation of electron/hole from photoexited semiconductors by forming heterojunctions, thus exhibit enhanced photocatalytic activities and potential applications. In this study, Pt-based NPs, including Pt, PtCu, and PtCuCo are employed as model co-catalysts to comparatively study their capability to enhance the photocatalytic activity of TiO₂ nanosheets. It was found that each of Pt, PtCu, and PtCuCo can greatly enhance the photocatalytic activity of TiO₂ toward degradation of organic dyes. Using electron spin resonance spectroscopy, we demonstrated that deposition of Pt-based NPs resulted in more production of reactive oxygen species including hydroxyl radicals, superoxide, and singlet oxygen. The enhancing effects of Pt-based NPs on generation of ROS and photocatalytic activity showed same trend: PtCuCo?>?PtCu?>?Pt. The mechanism underlying the enhancement differences in Pt-based NPs may be mainly related to electronic structure change of Pt in alloying with Cu and Co. These results are valuable for designing hybrid nanomaterials with high photocatalytic efficiency for applications in water purification and antibacterial products.     

Heteroepitaxy of Cerium Oxide Thin Films on Cu(111)

An important part of fundamental research in catalysis is based on theoretical and modeling foundations which are closely connected with studies of single-crystalline catalyst surfaces. These so-called model catalysts are often prepared in the form of epitaxial thin films, and characterized using advanced material characterization techniques. This concept provides the fundamental understanding and the knowledge base needed to tailor the design of new heterogeneous catalysts with improved catalytic properties. The present contribution is devoted to development of a model catalyst system of CeO₂ (ceria) on the Cu(111) substrate. We propose ways to experimentally characterize and control important parameters of the model catalyst—the coverage of the ceria layer, the influence of the Cu substrate, and the density of surface defects on ceria, particularly the density of step edges and the density and the ordering of the oxygen vacancies. The large spectrum of controlled parameters makes ceria on Cu(111) an interesting alternative to a more common model system ceria on Ru(0001) that has served numerous catalysis studies, mainly as a support for metal clusters.     

DNA methylation of the ELOVL2, FHL2, KLF14, C1orf132/MIR29B2C,and TRIM59 genes for age prediction from blood,saliva, and buccal swab samples

Many studies have reported age-associated DNA methylation changes and age-predictive models in various tissues and body fluids. Although age-associated DNA methylation changes can be tissue-specific, a multi-tissue age predictor that is applicable to various tissues and body fluids with considerable prediction accuracy might be valuable. In this study, DNA methylation at 5 CpG sites from the ELOVL2, FHL2, KLF14, C1orf132/MIR29B2C, and TRIM59 genes were investigated in 448 samples from blood, saliva, and buccal swabs. A multiplex methylation SNaPshot assay was developed to measure DNA methylation simultaneously at the 5 CpG sites. Among the 5 CpG sites, 3 CpG sites in the ELOVL2, KLF14 and TRIM59 genes demonstrated strong correlation between DNA methylation and age in all 3 sample types. Age prediction models built separately for each sample type using the DNA methylation values at the 5 CpG sites showed high prediction accuracy with a Mean Absolute Deviation from the chronological age (MAD) of 3.478 years in blood, 3.552 years in saliva and 4.293 years in buccal swab samples. A tissue-combined model constructed with 300 training samples including 100 samples from each blood, saliva and buccal swab samples demonstrated a very strong correlation between predicted and chronological ages (r = 0.937) and a high prediction accuracy with a MAD of 3.844 years in the 148 independent test set samples of 50 blood, 50 saliva and 48 buccal swab samples. Although more validation might be needed, the tissue-combined model’s prediction accuracies in each sample type were very much similar to those obtained from each tissue-specific model. The multiplex methylation SNaPshot assay and the age prediction models in our study would be useful in forensic analysis, which frequently involves DNA from blood, saliva, and buccal swab samples.     

经鼻高流量湿化氧疗在小儿先心病术后的疗效观察

目的探析经鼻高流量湿化氧疗用于小儿先心病术后治疗中的效果以及护理措施。方法2014年9月—2017年10月在郑州儿童医院外科监护室接受手术治疗的先心病患儿中随机抽取130例,根据术后氧疗方法不同分组:对照组患儿术后给予常规面罩吸氧,观察组患儿术后给予经鼻高流量湿化氧疗,2组患儿均给予优质术后护理,对比2组的血气指标、住院时间等。结果2组患者氧疗后24h、48h的血氧饱和度差异无统计学意义,在氧疗后24h的PaCO2水平差异无统计学意义,而在氧疗后24h和48h的氧合指数,观察组明显高于对照组,差异有统计学意义(P<0.05);2组ICU入住时间和总住院时间差异无统计学意义(P>0.05)。结论经鼻高流量湿化氧疗的应用提高先心病患儿术后的舒适度,改善呼吸状况,值得推广。     

高流量吸氧与面罩吸氧在胸腔镜辅助食管癌根治术后氧疗效果对比

目的观察高流量湿化吸氧与常规面罩吸氧在食管癌患者行胸腔镜辅助食管癌根治术后治疗的临床效果。方法将36例择期行胸腔镜辅助下食管癌根治术后患者随机分为常规面罩吸氧对照组(A组)和高流量湿化吸氧治疗组(B组),对两组患者治疗2 h、6 h和24 h后的呼吸频率、动脉血气分析等指标进行比较,了解两种吸氧方式在食管癌患者行胸腔镜辅助食管癌根治术后治疗上的优劣。结果两组患者治疗2 h、6 h和24 h的呼吸频率、动脉血气分析发现,A组动脉氧饱和度、动脉血氧分压较B组降低,动脉血二氧化碳分压、呼吸频率较B组增高,两组比较差异有统计学意义(均P0.01)。结论与常规面罩吸氧比较,高流量湿化面罩吸氧可以使胸腔镜辅助食管癌根治术后患者有更满意的氧合效果,值得在临床上推广。     

高压氧综合治疗糖尿病性胃轻瘫患者的疗效观察

目的观察高压氧（HBO）联合吗丁啉综合治疗对糖尿病性胃轻瘫患者胃动素及胃排空时间的影响。方法采用随机数字表法将2000年10月至2004年10月间连续人院的糖尿病性胃轻瘫患者112例随机分为高压氧组和对照组各46例，HBO组在给予吗丁啉（每次10mg，每天3次，连用4周）的基础上加用HBO治疗，HBO采用多人氧舱，在舱内停留120min，压力为0．25MPa（2．5ATA），戴面罩吸人纯氧60min（30min各2次，中间休息10min吸人舱内空气），10次为1个疗程，共3个疗程，每疗程间隔3～5d（排除HBO治疗禁忌证）。对照组为单纯吗丁啉，每次10mg，每天3次，连用4周。45d分别对两组患者治疗前后胃动素、空腹血糖、胃排空时间及症状的改善各项指标进行研究对比。结果HBO组和对照组总有效率分别为92．9％和76．8％，症状的改善、胃动素及胃排空时间治疗组均优于对照组，差异有显著性（P〈0．05）。结论糖尿病性胃轻瘫患者在服用吗丁啉的基础上应用HBO可降低胃动素、加速胃排空时间，对临床症状的改善具有积极作用。     

Rescue of the Cold Preserved Rat Liver by Hypothermic Oxygenated Machine Perfusion

The aim of the study was to investigate whether hypothermic oxygenated liver perfusion after cold liver preservation resuscitated metabolic parameters and whether this treatment had a benefit for liver viability upon reperfusion.
We preserved rat livers either by cold storage (UW) for 10 h, or by perfusion for 3 h (oxygenated modified UW) after 10 h cold storage. We assessed viability of livers after preservation and after ischemic rewarming + normothermic reperfusion ex vivo . Ten hour cold storage reduced mitochondrial cytochrome oxidase and metabolically depleted the livers. Oxygenated perfusion after cold storage resulted in uploaded cellular energy charge and oxidized mitochondrial cytochrome oxidase. Reperfusion after 10 h cold storage increased formation of superoxid anions, release of cytosolic LDH, lipid peroxidation, caspase activities and led to disruption of sinusoidal endothelial cells. In contrast, reperfusion after 10 h cold storage + 3 h hypothermic oxygenated perfusion resulted in no changes of lipid peroxidation, bile flow, energy charge, total glutathione, LDH release and of caspase activation, as compared to fresh resected livers.
This study demonstrates, that a metabolically depleted liver due to cold storage can be energy recharged by short-termed cold machine perfusion. The machine perfused graft exhibited improved viability and functional integrity.     

重度脑挫裂伤患者术后早期高压氧治疗疗效观察

目的探讨重度脑外伤患者早期高压氧治疗的临床效果。方法重度脑挫裂伤患者56例,入院时患者的格拉氏哥评分(glasgowcomascale,GCS)为3~8分,均于入院1h内行去骨瓣减压术或同时行血肿清除术;20例在伤后5~20h内行早期高压氧(HBO)治疗,36例在脑水肿消退后(7~18d)行常规HBO治疗。两组均治疗2个疗程。观察3周后重新GCS评分,6个月后进行格拉氏哥结果评级(glasgowoutcomescale,GOS)。结果两组患者治疗后3周GCS评分和6个月后GOS评分差异具有统计学意义。早期HBO治疗组明显优于常规HBO治疗组。结论早期的HBO治疗可以及时提高血氧含量,阻止恶性缺血缺氧的发生。重度脑挫裂伤患者术后在可能的条件下应尽早行HBO治疗,以提高患者的生存质量。     

不同浓度氯氮平对小鼠空腹血糖和骨骼肌葡萄糖转运蛋白4基因表达的影响

目的探讨氯氮平对雄性C57BL/6小鼠空腹血糖和骨骼肌葡萄糖转运蛋白4(GLUT4)基因表达的影响。方法将63只雄性C57BL/6小鼠随机分为3组,每组21只,分别灌胃给予蒸馏水、氯氮平4mg/kg及氯氮平20mg/kg,于给药后3h、1周、4周以试纸法测定各组空腹血糖,用逆转录-聚合酶链反应测定GLUT4mRNA表达。结果(1)灌药后3h、1周氯氮平4mg/kg组和氯氮平20mg/kg组空腹血糖和GLUT4mRNA的表达与空白对照组相比,差异无统计学意义(P>0.05);(2)灌药后4周氯氮平4mg/kg组和20mg/kg组的空腹血糖值[(5.6±0.5)mmol/L和(5.8±0.5)mmol/L]高于空白对照组[(4.6±0.6)mmol/L],而GLUT4mRNA的表达(0.50±0.14和0.48±0.12)却低于空白对照组(0.85±0.27),差异均有统计学意义(P<0.01)。结论氯氮平可以慢性升高空腹血糖,降低GLUT4mRNA的表达,可能是抗精神病药长期应用后血糖升高的发生机制之一。