A proteomic analysis of green and white sturgeon larvae exposed to heat stress and selenium

Temperature and selenium are two environmental parameters that potentially affect reproduction and stock recruitment of sturgeon in the San Francisco Bay/Delta Estuary. To identify proteins whose expression is modified by these environmental stressors, we performed a proteomic analysis on larval green and white sturgeons exposed to 18 or 26 °C and micro-injected with Seleno-L-Methionine to reach 8 µg g⁻¹ selenium body burden, with L-Methionine as a control. Selenium and high temperature induced mortalities and abnormal morphologies in both species, with a higher mortality in green sturgeon. Larval proteins were separated by two-dimensional gel electrophoresis and differential abundances were detected following spot quantitation and hierarchical cluster analysis. In green sturgeon, 34 of 551 protein spots detected on gels showed a variation in abundance whereas in white sturgeon only 9 of 580 protein spots were differentially expressed (P < 0.01). Gel replicates were first grouped according to heat treatment. Fifteen of these spots were identified using MALDI TOF/TOF mass spectrometry. Proteins involved in protein folding, protein synthesis, protein degradation, ATP supply and structural proteins changed in abundance in response to heat and/or selenium. 40S ribosomal protein SA, FK506-binding protein 10, 65 kDa regulatory subunit A of protein phosphatase 2, protein disulfide isomerase, stress-induced-phosphoprotein 1, suppression of tumorigenicity 13 and collagen type II alpha 1, were differentially expressed in high temperature treatment only. Serine/arginine repetitive matrix protein 1, creatine kinase, serine peptidase inhibitor Kazal type 5 and HSP90 were sensitive to combined temperature and selenium exposure. Valosin-containing protein, a protein involved in aggresome formation and in protein quality control decreased more than 50% in response to selenium treatment. Potential use of such proteins as biomarkers of environmental stressors in larval sturgeons could indicate early warning signals preceding population decline.     

基于“互联网+TPR”的逆向物流回收网络体系研究

目的 为了使快递包装回收更加智能系统化，构建“互联网+TPR”回收新模式，在此基础上搭建北京市快递包装逆向物流回收网络新体系。方法 首先对4种回收模式进行定性分析，然后构建4种回收模式的数学模型，通过对比分析，得出利润最大、回收数量最多的回收模式，最后根据选出的回收模式建立逆向物流回收网络新体系。结果 由定性和定量分析的结果可知，“互联网+TPR”回收模式较其他3种传统的回收模式更适合于北京市快递包装废弃物的回收。结论 以北京市快递包装为研究对象，提出了北京快递包装逆向物流回收新模式，构建了“互联网+TPR”快递包装逆向物流回收网络新体系，解决了中小型企业的投入成本大、利润分配不均、信息流通慢等问题。     

载体对La0.8Sr0.2CoO3燃烧催化剂性能的影响

用浸渍法制备负载型La0.8Sr0.2CoO3燃烧催化剂,比较了γ-Al2O3和堇青石(Cordierite,2MgO·2Al2O3·5SiO2)载体的负载效果和这两种催化剂二甲苯完全氧化的催化活性。利用TPR和XPS等手段对两种催化剂的结构性质进行了表征。     

Methane Combustion and TPR/TPO Properties of Pd/CexZr1-xO2/Al2O3 Catalysts

Methane Combustion and TPR/TPO Properties of Pd/Ce_xZr_ 1-xO_2/Al_2O_3 Catalysts     

Identification of Pd3+ ions in zeolite L by temperature programmed reduction and electron paramagnetic resonance spectroscopy

Pd supported on KL zeolite has been studied by temperature programmed reduction (TPR) and electron paramagnetic resonance (EPR) spectroscopy. It has been found that upon calcination in pure oxygen Pd³⁺ and Pd²⁺ ions are formed; the Pd³⁺ ions are identified by their EPR signal. As Pd³⁺ ions in the cancrinite cages are difficult to reduce, the H₂ consumption in conventional TPR is below the stoichiometric amount.     

The influence of a second metal component (Cu,Sn, Fe) on Pd/SiO2 activity in the hydrogenation of 2,4-dinitrotoluene

The catalytic activity of palladium in the hydrogenation of 2,4-dinitrotoluene is reduced by the addition of Cu or Sn. Upon addition of Fe, the activity increases. The formation of highly dispersed Pd-Fe bimetallic aggregates is suggested, where the Fe atoms, contiguous to Pd, act as promoters activating of the N=O bond.     

离群点检测算法的评价指标

随着离群点检测技术的深入研究和广泛应用,越来越多的优秀算法被提出来,然而,现有的离群点检测技术的评价仍然沿用传统分类算法的测量指标,存在着评价指标单一、适应性差的问题。针对这些问题,提出了一类高真正率指标（HT_AUC）和二类低假正率指标（LF_AUC）。首先,整理常用的离群点检测评价指标,分析其优缺点和适用场景;然后,在已有的曲线下面积（AUC）方法的基础上,分别针对高真正率（TPR）要求和低假正率（FPR）要求,提出了一类高真正率指标和二类低假正率指标,为离群点检测算法的效果评价和量化集成提供了更合适的指标。在真实数据集上的实验结果表明,与传统评价指标的相比,所提出的方法更能满足一类高真正率和二类低假正率要求。     

The effect of Mo on the catalytic and surface properties of Rh-Mo/ZrO2 catalysts

A series of Rh-Mo/ZrO₂ catalysts with fixed Rh and different Mo loadings were prepared and characterized by H₂ chemisorption, XRD, TPR, TEM and XPS. The catalysts were studied in two reactions: the hydrogenation of carbon monoxide and the hydrogenation of toluene. The results suggest that the increase in the Mo content produces a partial coverage of the support and the Rh particles. Moreover, at high Mo coverage, an increase of the MoO₃ layer thickness is produced. After being treated in hydrogen, the molybdenum oxide remains as slightly reduced particles, while Rh is essentially as Rh⁰, with only a small contribution of Rh+ species. The Mo promotes the formation of oxygenates in the CO hydrogenation and it does not affect the activity in the hydrogenation of toluene.     

Evidence for anchoring and partial occlusion of metallic clusters on the pore walls of MCM-41 and effect on the stability of the metallic clusters

In order to explain the high stability of the Co- and Ni-MCM-41 catalysts, the hypotheses of anchoring of small metallic clusters to cations in and partial occlusion of the metallic clusters by amorphous silica are proposed. Carbon monoxide chemisorption on model catalysts and Co-MCM-41 has given direct proof of the metal anchoring effect on the stability of metal cluster dispersion. The partial occlusion of metallic clusters, which may lead to physical confinement (inhibited migration) or chemical confinement (inhibited reaction), was monitored by CO in situ FTIR and CO methanation along with a kinetic study, which confirmed that the metallic clusters on the pore surface result in the stabilization of the catalysts against deactivation. A fine tuning of these physicochemical phenomena in the transition metal incorporated MCM-41 will make possible the design of stable catalytic systems for reactions requiring metallic active sites under severe reaction conditions.     

Cu,Co, Ag-Containing Pillared Clays as Catalysts for the Selective Reduction of NOx by Hydrocarbons in an Excess of Oxygen

Thermally stable Al- and Zr-PILC loaded with copper and cobalt cations and silver nanoparticles were synthesized. The structural and surface features of these nanosystems were studied and compared with those of bulk analogs – partially stabilized ZrO₂ loaded with the same active components. Specificity of the catalytic properties of nanocomposites in SCR of NO _x by propane, propylene and decane in the excess of oxygen appears to be determined both by distribution of active components on the catalytic surface and degree of their interaction with supports. Formation of ads.-NO _x , nitroxyl-hydrocarbon C _x H _y NO₂ and isocyanate NCO intermediates was observed by ESR and IR spectroscopy in situ.