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CO oxidation and 4-nitrophenol reduction over ceria-promoted platinum nanoparticles impregnated with ZSm-5 zeolite

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Journal of Rare Earths 2022年第8期40卷 1247-1254页

作者： Zeinhom m.El-Bahy mohammed T.Alotaibi salah m.El-Bahy Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt Department of Chemistry Turabah University CollegeTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

Active new ceria-promoted platinum supported on ZSm-5 catalysts were prepared and characterized by X-ray diffraction(XRD),Fourier transform infrared spectra(FTIR),transform electron microscopy(TEm),temperature programmed desorption(TPD),and FTIR of CO *** samples were prepared by the incipient wetness impregnation method and calcined at 500℃.The XRD patterns and FTIR spectra prove that the zeolite framework is kept unaltered after metal *** images prove the presence of Pt nanoparticles with particle size starting from 14 to 27 *** FTIR data suggest the formation of Pt-O-Ce ***-situ FTIR of CO adsorption over reduced samples proves the presence of Pt~0 only,and no Pt^(n+)-CO species are *** prepared catalysts were tested in both oxidation reaction(CO oxidation) in the gas phase and in reduction reaction(4-nitrophenol reduction) in the aqueous ***,CO oxidation by O_(2) results in the formation of a CO_(2) peak at 2347 cm^(-1) as the only CO oxidation product in the studied frequency *** intensity of the CO_(2) peak increases after the addition of Ce,and it is 4 times higher in Pt_(1) Ce_(0.5)ZSm-5 than that in the Ce-free *** to the FTIR data and previous reports,the increase in the catalytic activity may be due to the formation of Pt-O-Ce ***,Ce-promoted Pt_(1) ZSm5 also exhibits enhanced catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol by NaBH_(4) in the aqueous *** first-order rate constant of the reduction increases ≈13 times after incorporating equal ratios of Pt and Ce(Pt_(1) Ce_(1)ZSm-5),and the activation energy(E_(a)) decreases to 40% of that in the reaction over Pt_(1) ZSm-5.

关键词： 4-Nitrophenol CO oxidation TPD-CO Platinum-cerium ZSm-5 Rare earths

Liver stiffness as a predictor of hepatocellular carcinoma behavior in patients with hepatitis C related liver cirrhosis

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Hepatobiliary & Pancreatic Diseases International 2020年第1期19卷 22-28页

作者： Sameh A Lashen mohamed m Elshafei Fahmy H Hablass eman A Alsayed Asmaa A Hassan Department of Internal medicine Faculty of MedicineUniversity of AlexandriaAlexandriaEgypt Department of Radiology Faculty of MedicineUniversity of AlexandriaAlexandriaEgypt Department of Biomedical Informatics and medical Statistics Medical Research InstituteUniversity of AlexandriaAlexandriaEgypt

Background: Risk strati cation and prognostication of hepatocellular carcinoma (HCC) help to improve patient outcome. Herein we investigated the role of liver stiffness measurement (LSm) in the prediction of HCC behavior. methods: Totally 121 na ve patients with HCC were included. HCC radiological evaluation and staging were done. LSm was measured using virtual touch quanti cation. Patients were divided into early to intermediate HCC (BCLC-0, A and B) and late HCC (BCLCC and D). HCC was treated according to the BCLC stage. HCC recurrence-free interval was estimated. Results: The mean LSm inside the tumor was signi cantly lower than the peri-tumoral area and the cirrhotic non-cancerous liver parts (Pmean LSm inside the tumor and in the peri-tumoral tissue was lower than the corresponding values in the early to intermediate HCCs stage (Pm inside the tumor and in the peri-tumoral tissue negatively correlated with serum AFP, tumor vascular invasion, and stage (Pm inside the tumor and inversely to LSm in cirrhotic non tumorous liver part. Kaplan-meier analysis showed that the recurrence-free interval was signi cantly longer in patients with LSm inside the tumor of ≥1.25m/s compared to those with LSm inside the tumor ofm/s. Conclusions: LSm can serve as a potential non-invasive predictor for HCC clinical behavior and the recurrence-free interval following loco-regional treatments.

关键词： Fibrosis Hepatitis C Hepatocellular carcinoma Point shear wave Liver cirrhosis

Synthesis, Structural Characterization, and Antimicrobial Activities of mn（II）, Co（II）, Ni（II）, Cu（ll） and Zn（II） Complexes of Triazole-based Azodyes

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Chinese Journal of Chemistry 2011年第6期29卷 1124-1132页

作者： Khedr, Abdalla m. Gaber, mohamed Abd EI-Zaher, eman H. Chemistry Department Faculty of Science Tanta University Tanta Egypt Botany Department Faculty of Science Tanta University Tanta Egypt

The synthesis and characterization of new transition metal complexes of mn（ll）, Co（II）, Ni（II）, Cu（II） and Zn（II） with 3-（2-hydroxynaph-l-ylazo）-1,2,4-triazole （HL1） and 3-（2-hydroxy-3-carboxynaph-l-ylazo）-1,2,4-triazole （HL2） have been carried out. Their structures were confirmed by elemental analyses, thermal analyses, spectral and magnetic data. The IR and 1H NmR spectra indicated that HL1 and HL2 coordinated to the metal ions as bidentate monobasic ligands via the hydroxyl O and azo N atoms. The UV-Vis, ESR spectra and magnetic moment data revealed the formation of octahedral complexes [mnL1（AcO）（H2O）3] （1）, [CoL1（AcO）（HzO）3]·H2O （2）, [mnL2- （AcO）（H20）3] （6） and [CoL2（AcO）（H2O）3] （7）, [NiL1（AcO）（H2O）] （3）,[ZnLI（AcO）（HzO）]·H2O （5）, [NiL2- （AcO）（H2O）] （8）, [ZnL2（AcO）（H2O）]·H2O （10） have tetrahedral geometry, whereas [CuLI（AcO）（H2O）2] （4） and [CuL2（AcO）（H2O）2]·5H2O （9） have square pyramidal geometry.. The mass spectra of the complexes under EI-con- ditions showed the highest peaks corresponding to their molecular weights, based on the atomic weights of 55mn, 59Co, 58Ni, 63Cu and 64Zn isotopes; besides, other peaks containing other isotopes distribution of the metal. Kinetic and thermodynamic parameters of the thermal decomposition stages were computed from the thermal data using Coats-Redfern method. HL2 and complexes 6--10 were found to have moderate antimicrobial activities against Staphylococcus＇ aureus （gram positive）, Escherichia coli （gram negative） and Salmonella sp bacteria, and antifungal activity against Fusarium oxysporum, Aspergillus niger and Candida albicans. Also, in most cases, metallation increased the activity compared with the free ligand.

关键词： analytical and inorganic chemistry triazole azodyes metal(II) chelates antimicrobial activities

Effect of biochar on fate and transport of manure-borne estrogens in sandy soil

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Journal of Environmental Sciences 2018年第11期30卷 162-176页

作者： Sanaz Alizadeh Shiv O.Prasher eman ElSayed Zhiming Qi Ramanbhai m.Patel Department of Bioresource Engineering McGill University Department of Plant Protection Faculty of AgricultureZagazig University

The feasibility of using two types of biochars to reduce steroid hormone pollution from poultry and swine manure application on agricultural land was evaluated. The sorption affinity and desorption resistance of softwood and hardwood biochars were also determined for two estrogen hormones, 17β-estradiol （E2） and its primary metabolite estrone （E1）. The softwood and hardwood biochars demonstrated high retention capacity for both estrogens. The effective distribution coefficient （Kedff） of soil-softwood-derived biochar （SBS450） was significantly higher than soil-hardwood-derived biochar （SBH750）, indicating the stronger sorption affinity of SBS450 for estrogens. To validate the laboratory results, a field lysimeter experiment was conducted to study the fate and transport of E2 and E1 in soil and leachate in the presence of 1% softwood-biochar （BS450） in topsoil and to compare it with soil without any amendments. The spatio-temporal distribution of both estrogens was monitored at four depths over a 46-day period. The lysimeters, in which the surface layer of soil was amended with biochar, retained significantly higher concentrations of both estrogen hormones. Although they leached through the soil and were detected in leachates, collected at 1.0 m depth, the concentrations were significantly lower in the leachate collected from biochar-amended lysimeters. The result confirmed the efficacy of biochar amendment as a remediation technique to alleviate the manure-borne hormonal pollution of groundwater.

关键词： Estrogen Sorption Desorption Biodegradation Biochar manure Transport

Can lanthanum doping enhance catalytic performance of silver in direct propylene epoxidation over NamoAg/SiO_2?

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Journal of Rare Earths 2019年第5期37卷 500-507页

作者： Hany m.Abdel Dayem Shar S.Al-Shihry salah A.Hassan Chemistry Department Faculty of Science Ain Shams University Chemistry Department College of Science King Faisal University

In the attempt to reduce surface free energy of silica to improve interaction of silica with silver, silica was doped by different amounts of low surface energy lanthanum, La_2O_3, through impregnation. The doped and undoped silica were used as supports for preparation of Na/Ag/mo/La_2O_3-SiO_2 catalysts. Catalytic performances of the catalysts were evaluated in direct epoxidation of propylene(DPO) using molecular oxygen under atmospheric pressure and without adding hydrogen. Adding 5 wt%La to the Na/Ag/mo/SiO_2 catalyst improves both the catalysts electivity in DPO and its stability over 20h of *** characterization results show that La_2O_3 species interact strongly with silver particles on the silica surface which result in significant improvement in the dispersion profile of silver and marked decrease in the size of silver nanoparticles(AgNPs). The estimated mean diameter of AgNPs is ca. 4.0 nm in Na/Ag/mo/5 wt%La_2O_3-SiO_2, which is smaller than that(53.9 nm) found in Na/Ag/SiO_2. The presence of subnanometer AgNPs on Ag/La_2O_3-SiO_2 prior addition of moO_3 and NaCl to the sample can enhance the mutual electronic synergism between Ag, moO_3 and Na for selective production of propylene oxide.

关键词： Direct epoxidation Propylene Gas phase Silver Subnanometer Lanthanum

Industrial Food Quality Analysis Using New k-Nearest-Neighbour methods

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Computers, materials & Continua 2021年第5期67卷 2681-2694页

作者： Omar Fetitah Ibrahim m.Almanjahie mohammed Kadi Attouch salah Khardani Laboratory of Statistics and Stochastic Processes University of Djillali LiabesSidi Bel Abbes22000Algeria Department of mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Statistical Research and Studies Support Unit King Khalid UniversityAbha62529Saudi Arabia Facultédes sciences de Tunis Laboratoire des Réseaux Intelligents et NanotechnologieTunisTunisia

The problem of predicting continuous scalar outcomes from functional predictors has received high levels of interest in recent years in many fields,especially in the food *** k-nearest neighbor(k-NN)method of Near-Infrared Reflectance(NIR)analysis is practical,relatively easy to implement,and becoming one of the most popular methods for conducting food quality based on NIR *** k-NN is often named k nearest neighbor classifier when it is used for classifying categorical variables,while it is called k-nearest neighbor regression when it is applied for predicting noncategorical *** objective of this paper is to use the functional Near-Infrared Reflectance(NIR)spectroscopy approach to predict some chemical components with some modern statistical models based on the kernel and k-Nearest Neighbour *** this paper,three NIR spectroscopy datasets are used as examples,namely Cookie dough,sugar,and tecator ***,we propose three models for this kind of data which are Functional Nonparametric Regression,Functional Robust Regression,and Functional Relative Error Regression,with both kernel and k-NN approaches to compare between *** experimental result shows the higher efficiency of k-NN predictor over the kernel *** predictive power of the k-NN method was compared with that of the kernel method,and several real data sets were used to determine the predictive power of both methods.

关键词： Functional data analysis classical regression robust regression relative error regression kernel method k-NN method near-infrared spectroscopy

Tribological Investigation of HDPE-cuttlebone and HDPE-red Coral Composites

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Journal of Bionic Engineering 2019年第6期16卷 1068-1079页

作者： Amira Salem Walid Bensalah salah mezlini Universite de monastir Ecole Nationale d'Ingenieurs de Monastir(ENIM)Laboratoire de Genie Mecanique(LGM)LR99ES325019MonastirTunisia

In this paper,the tribological properties of cuttlebone(CB)-reinforced high density polyethylene(HDPE)and Red Coral(RC)-reinfbrced HDPE composites were *** composite specimens were prepared with a hot compression molding machine using different weight proportions of fillers blended with *** tribological behavior of the composite disks was studied using pin-on-disk tribometer under dry condition against stainless steel m30NW *** coefficient of friction as well as wear rate were examined to study the effects of the two fillers on the tribological perfonnance of both *** wear tests,different composites were examined using a Scanning Electron microscope(SEm).It was fbund that the use of cuttlebone(CB)and Red Coral(RC)as reinforcement improved the tribological properties of HDPE.

关键词： cuttlebone-reinforced HDPE red coral-reinforced HDPE wear rate friction coefficient wear mechanism

Rare earth oxides doped NiO/γ-Al_2O_3 catalyst for oxidative dehydrogenation of cyclohexane

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Journal of Rare Earths 2015年第6期33卷 611-618页

作者： Hany m.AbdelD ayem m.Faiz Hesham S.Abdel-Samad salah A.Hassan Center of Research Excellence in Petroleum Refining & Petrochemicals (CoR E-PRP) King Fahd University of Petroleum & Minerals Chemistry Department College of Science King Faisal University Chemistry Department Faculty of Science Ain Shams University Surface Science Laboratory Physics Department King Fahd University of Petroleum &Minerals Department of Basic Sciences and Technology Community College Taibah University

The effect of rare earth oxides （RE=Ce, La, Gd, and Dy） doping of alumina support in NiO/7-A1203 system was investi- gated on its catalytic performance in oxidative dehydrogenation （ODH） of cyclohexane. The physicochemical properties of various samples were followed up through N2 physisorption, temperature programmed reduction （H2-TPR）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and potentiometric acid-base titration techniques. In the parent NiO/y-A1203 catalyst, Ni species were found to be strongly interacted with alumina surface. Addition of rare earth dopants to ）＇-A1203 in the catalyst system affected the nickel-alumina interaction and resulted in significant modifications in the catalytic performances in the ODH reaction. The results re- vealed the beneficial role of both La203 and Gd2Os doping in enhancing the ODH catalytic activity and selectivity to cyclohexene. H2-TPR and XPS results indicated that majority of Ni species in NiO/La203 modified T-A1203 were more weakly interacted with La203 and alumina whereas both NiO like species and nickel aluminate were present on the surface. Doping with cerium or dyspro- sium increased the nickel-support interaction and led to a decrease in surface nickel concentration. In case of doping with Ce, surface concentration of cerium oxide was higher than those of the other RE oxides; the doped catalyst reached its steady state activity faster than the other catalysts. The acid-base results suggested that RE metals were interacted most likely with acidic surface hydroxyl groups. The degree of nickel-alumina interaction decreased in the following order： LaAI〉GdAI〉CeAI〉DyA1.

关键词： nickel oxide rare-earth oxides doping Ni-A1203 interaction surface acidity oxidative dehydrogenation cyclohexane rare earths

monocyte/macrophage-mediated Innate Immunity in HIV-1 Infection:From Early Response to Late Dysregulation and Links to Cardiovascular Diseases Onset

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Virologica Sinica 2021年第4期36卷 565-576页

作者： eman Teer Danzil E.Joseph Richard H.Glashoff m.Faadiel Essop Centre for Cardio-metabolic Research in Africa(CARmA) Department of Physiological SciencesStellenbosch UniversityStellenbosch 7600South Africa Division of medical microbiology&Immunology Department of PathologyStellenbosch University and NHLSCape Town 7505South Africa

Although monocytes and macrophages are key mediators of the innate immune system,the focus has largely been on the role of the adaptive immune system in the context of human immunodeficiency virus(HIV)*** more attention and research work regarding the innate immune system-especially the role of monocytes and macrophages during early HIV-1 infection-is *** monocytes and tissue macrophages are both susceptible targets of HIV-1 infection,and the early host response can determine whether the nature of the infection becomes pathogenic or *** example,monocytes and macrophages can contribute to the HIV reservoir and viral persistence,and influence the initiation/extension of immune activation and chronic *** the expansion of monocyte subsets(classical,intermediate and non-classical)provide an increased understanding of the crucial role they play in terms of chronic inflammation and also by increasing the risk of coagulation during HIV-1 *** review discusses the role of monocytes and macrophages during HIV-1 pathogenesis,starting from the early response to late dysregulation that occurs as a result of persistent immune activation and chronic *** changes are also linked to downstream targets such as increased coagulation and the onset of cardiovascular diseases.

关键词： monocytes Human immunodeficiency virus(HIV) Persistent immune activation Coagulation Cardiovascular diseases(CVD)