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CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and pt)

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Journal of Rare Earths 2024年第9期42卷 1669-1681页

作者： J.C.martínez-munuera m.p.yeste A.García-García mCmA Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of Alicante Solid Chemistry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of Cádiz

In this work,several ceria-zirconia based catalysts with very lo w（and equimolar） metal contents were prepared,characterised and tested for the CO oxidatio n reaction（under lean and stoichiometric conditions）,trying to emulate those conditions found in a diesel oxidation catalyst（DOC） system from a diesel engine and those encountered under gasoline exhaust（λ=1）.The metals chosen are Cu,Co,Ag and pt（as a reliable benchmark）.The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion（Ag-catalyst seems to present a low level of dispersion）.This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H2-TpR ***,the order in catalytic activity（Cu>Ag>Co≈pt>>support） seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce0.8Zr0.2O2-supported metal catalysts is ***,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H2-TpR measurements.

关键词： CO oxidation Low metal content Ceria-zirconia Copper species OSC parameter Rare earths

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Chromatin condensation but not DNA integrity of pig sperm is greater in the sperm-rich fraction

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Journal of Animal Science and Biotechnology 2024年第1期15卷 171-181页

作者： Estel Viñolas-Vergés Jordi Ribas-maynou Isabel Barranco Camila peres Rubio Sergi Bonet Jordi Roca marc yeste Unit of Cell Biology Department of BiologyFaculty of SciencesUniversity of GironaGironaSpain Biotechnology of Animal and Human Reproduction(TechnoSperm) Institute of Food and Agricultural TechnologyUniversity of GironaGironaSpain Department of medicine and Animal Surgery Faculty of Veterinary ScienceUniversity of MurciaMurciaSpain Catalan Institution for Research and Advanced Studies(ICREA) S08010 BarcelonaSpain

Background protamination and condensation of sperm chromatin as well as DNA integrity play an essential role during fertilization and embryo *** some mammals,like pigs,ejaculates are emitted in three separate fractions:pre-sperm,sperm-rich(SRF)and post sperm-rich(pSRF).These fractions are known to vary in volume,sperm concentration and quality,as well as in the origin and composition of seminal plasma(Sp),with differences being also observed within the SRF ***,whether disparities in the DNA integrity and chromatin condensation and pro-tamination of their sperm exist has not been *** This study determined chromatin protamination(Chromomycin A3 test,CmA_(3)),condensation(Dibromobi-mane test,DBB),and DNA integrity(Comet assay)in the pig sperm contained in the first 10 m L of the SRF(SRF-p1),the remaining portion of the sperm-rich fraction(SRF-p2),and the post sperm-rich fraction(pSRF).While chromatin protamination was found to be similar between the different ejaculate fractions(p>0.05),chromatin condensation was seen to be greater in SRF-p1 and SRF-p2 than in the pSRF(p=0.018 and p=0.004,respectively).Regarding DNA integrity,no differences between fractions were observed(p>0.05).As the SRF-p1 has the highest sperm concentra-tion and ejaculate fractions are known to differ in antioxidant composition,the oxidative stress index(OSi)in Sp,calcu-lated as total oxidant activity divided by total antioxidant capacity,was tested and confirmed to be higher in the SRF-p1 than in SRF-p2 and pSRF(0.42±0.06 vs.0.23±0.09 and 0.08±0.00,respectively;pperm concentration of each fraction(Rs=0.973;pperm DNA integrity was not found to differ between ejaculate fractions,SRF-p1 and SRF-p2 were observed to exhibit greater chromatin condensation than the *** could be related to the OSi of each fraction.

关键词： Chromatin Condensation DNA integrity Ejaculate fractions pig protamination Sperm

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Expression of miR‑138 in cryopreserved bovine sperm is related to their fertility potential

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Journal of Animal Science and Biotechnology 2023年第6期14卷 2383-2394页

作者： Albert Salas‑Huetos Jordi Ribas‑maynou Yentel mateo‑Otero Carolina Tamargo marc Llavanera marc yeste Unit of Cell Biology Department of BiologyFaculty of SciencesUniversity of GironaGirona 17003Spain. Biotechnology of Animal and Human Reproduction(TechnoSperm) Institute of Food and Agricultural TechnologyUniversity of GironaGirona 17003Spain. Department of Nutrition Harvard T.H.Chan School of Public HealthHarvard UniversityBostonMA 02115USA. Consorcio CIBER M.P.Fisiopatologia de la Obesidad y Nutricion(CIBERobn)Instituto de Salud Carlos III(ISCIII)Madrid 28029Spain. present Address:Unit of preventive medicine and public Health Faculty of Medicine and Health SciencesUniversitat Rovira i VirgiliReus 43201Spain. Department of Animal Selection and Reproduction The Regional Agri-Food Research and Development Service of Asturias(SERIDA)Gijon 33394Spain. Catalan Institution for Research and Advanced Studies(ICREA) Barcelona 08010Spain.

Background microRNAs(miRNAs)are small,single-stranded,non-coding RNA molecules of 22–24 nucleotides that regulate gene *** the last decade,miRNAs have been described in sperm of several mammals,including *** is known that miRNAs can act as key gene regulators of early embryogenesis in mice and humans;however,little is known about the content,expression,and function of sperm-borne miRNAs in early bovine *** this study,total sperm RNA was isolated from 29 cryopreserved sperm samples(each coming from a separate bull)using a RNeasy kit and treatment with DNase *** concentration and purity were determined through an Epoch spectrophotometer and an Agilent *** expression of 10 candidate miRNAs in bovine sperm(bta-miR-10a,bta-miR-10b,bta-miR-138,bta-miR-146b,bta-miR-19b,bta-miR-26a,bta-miR-34a,bta-miR-449a,bta-miR-495 and btamiR-7),previously identified in testis and/or epididymis,was evaluated with *** cel-miR-39-3p was used as a spike-in exogenous *** mann–Whitney tests were run to evaluate which miRNAs were differentially expressed between bulls with high fertility[HF;non-return rates(NRR)ranging from 39.5 to 43.5]and those with subfertility(SF;NRR ranging from 33.3 to 39.3).Several sperm functionality parameters(e.g.,viability,membrane stability or oxygen consumption,among others)were measured by multiplexing flow cytometry and oxygen sensing *** RNA concentration and purity(260/280 nm ratio)(mean±SD)from the 29 samples were 99.3±84.6 ng/μL and 1.97±0.72,*** results confirmed the lack of RNA from somatic *** terms of the presence or absence of miRNAs,and after applying the Livak method,8 out of 10 miRNAs(bta-miR-10b,-138,-146b,-19b,-26a,-449a,-495,-7)were consistently detected in bovine sperm,whereas the other two(bta-miR-10a,and-34a)were ***,the relative expression of one miRNA(bta-miR-138)in sperm was significantly lower in the SF than in the HF gr

关键词： Bovine Fertility miRNAs Sperm

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