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Synthesis and Characterization of Gadolinium Oxide-Hematite Magnetic Ceramic Nanostructures

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j.urnal of Minerals and Materials Characterization and Engineering 2023年第1期11卷 1-15页

作者： sarah Glasser Andrew j. Craig Felicia Tolea Mihaela Sofronie j.nnifer A. Aitken Monica Sorescu Department of Physics Duquesne University Fisher Hall Pittsburgh PA USA Department of Chemistry and Biochemistry Duquesne University Mellon Hall Pittsburgh PA USA National Institute of Materials Physics Bucharest-Magurele Romania

Mixed-oxide nanostructures of the type xGd2O3-(1-x)α-Fe2O3 (x=0.1, 0.3, 0.5 and 0.7) were synthesized by mechanochemical activation for ball milling times of 0, 2, 4, 8 and 12 hours. The systems were subsequently analyzed by Mӧssbauer spectroscopy, X-ray powder diffraction (XRPD), magnetic measurements and optical diffuse reflectance spectroscopy. The magnetic hyperfine field was studied as function of ball milling time for all sextets involved and found to be consistent with the formation of a limited solid solution in the systems investigated. The end-product was the gadolinium perovskite, represented by a doublet whose abundance was derived as function of the milling time. The XRPD patterns recorded for the equimolar composition were dominated by the diffraction peaks of GdFeO3 after 12 hours of milling. The hysteresis loops were recorded at 300 and 5 K in an applied magnetic field of 5 T and were interpreted as a superposition of paramagnetic behavior of gadolinium oxide and weak ferromagnetic behavior of hematite and gadolinium perovskite. The Morin transition of hematite was inferred from zero-field-cooling-field-cooling (ZFC-FC) curves measured with a magnetic field of 200 Oe in the 5-300 K temperature range and was found to depend on the ball milling time. Optical diffuse reflectance spectra showed that the compounds were semiconductors with an optical band gap of 2.1 eV.

关键词： Gadolinium Oxide Hematite Mӧssbauer Spectroscopy Magnetic Properties Optical Properties

Collecting Ophiocordyceps sinensis:an emerging livelihood strategy in the Garhwal,Indian Himalaya

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j.urnal of Mountain Science 2017年第2期14卷 390-402页

作者： Laura CAPLINS sarah j.HALVORSON Department of Society and Conservation College of Forestry and ConservationUniversity of MontanaMissoulaMontana59812USA Department of Geography College of Arts and SciencesUniversity of MontanaMissoulaMontana59812USA

In the Garhwal of Uttarakhand, India, the Bhotiya, an ethnically and culturally distinct tribal group, were historically engaged in seasonal migration(i.e. transhumance) to take advantage of scarce mountain resources and trade relations with Tibet. This livelihood practice has all but *** are adapting to these changing circumstances by engaging in the collection and sale of the valuable alpine medicinal fungus Ophiocordyceps sinensis, widely known as Cordyceps. The collection of this fungus has exploded, emerging as a lucrative yet high-risk livelihood strategy for many Bhotiya *** Bhotiyas' historic herding and trade-based interactions and knowledge of these alpine environments where Cordyceps are found uniquely positions them to access this valuable biological resource. Elsewhere in the Himalayan region, some households are earning as much as two-thirds of their income from the collection of Cordyceps; in China Cordyceps is now listed as an endangered species due to intense over-exploitation in the Tibetan *** paper seeks to fill the void in the scientific literature on the social, ecological and economic aspects of the emerging Cordyceps trade in the Garhwal. Our study investigates the socio-spatial dimensions of Cordyceps collection in the high alpine meadows. We document how a fusion of local knowledge and practice with alpine mountain systems has served to reinvigorate the economic integrity of mountain communities at a time of rapid socioeconomic change and to reimagine a new relationship between alpine resources and community *** article offers suggestions to address the sustainability of both Cordyceps collection and livelihood activities which hinge on this fungus population. We find a need for(1) community-based conservation measures that are rooted in(2) secure resource access rights for local communities to continue sustainable collection and sale of Cordyceps and(3) participatory-and science-based proc

关键词：喜马拉雅地区冬虫夏草采集印度社会经济社区生活山地资源高山环境

Tyrosine phosphorylation and bacterial virulence

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International j.urnal of Oral Science 2012年第1期4卷 1-6页

作者： sarah E Whitmore Richard j.Lamont Center for Oral Health and Systemic Disease School of DentistryUniversity of Louisville

Protein phosphorylation on tyrosine has emerged as a key device in the control of numerous cellular functions in *** this article,we review the structure and function of bacterial tyrosine kinases and *** is catalyzed by autophosphorylating adenosine triphosphate-dependent enzymes（bacterial tyrosine（BY） kinases） that are characterized by the presence of Walker *** reverse reaction is catalyzed by three classes of enzymes：the eukaryotic-like phosphatases（PTPs） and dual-specific phosphatases;the low molecular weight protein-tyrosine phosphatases（LMW-PTPs）;and the polymerase-histidinol phosphatases（PHP）.Many BY kinases and tyrosine phosphatases can utilize host cell proteins as substrates,thereby contributing to bacterial *** tyrosine phosphorylation/dephosphorylation is also involved in biofilm formation and community *** Porphyromonas gingivalis tyrosine phosphatase Ltp1 is involved in a restraint pathway that regulates heterotypic community development with Streptococcus ***1 is upregulated by contact with *** and Ltp1 activity controls adhesin expression and levels of the interspecies signal AI-2.

关键词： oral biofilm Porphyromonas gingivalis Streptococcus tyrosine phosphorylation virulence

Doped graphene/carbon black hybrid catalyst giving enhanced oxygen reduction reaction activity with high resistance to corrosion in proton exchange membrane fuel cells

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j.urnal of Energy Chemistry 2022年第5期31卷 143-153页

作者： Zhaoqi j. j.anuo Chen María Pérez-Page Zunmin Guo Ziyu Zhao Rongsheng Cai Maxwell T.P.Rigby sarah j.Haigh Stuart M.Holmes School of Automotive Engineering Harbin Institute of TechnologyWeihai264209ShandongChina Department of Chemical Engineering and Analytical Science The University of ManchesterManchester M139PLUK Department of Materials The University of ManchesterManchester M139PLUK

Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.

关键词： Nitrogen doped graphene Low-temperature hydrogen fuel cell Catalyst degradation Carbon corrosion

Effects of amyloid precursor protein peptide APP96-110,alone or with human mesenchymal stromal cells,on recovery after spinal cord inj.ry

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Neural Regeneration Research 2022年第6期17卷 1376-1386页

作者： Stuart I.Hodgetts sarah j.Lovett D.Baron-Heeris A.Fogliani Marian Sturm C.Van den Heuvel Alan R.Harvey School of Human Sciences The University of Western Australia(UWA)PerthWAAustralia Perron Institute for Neurological and Translational Science PerthWAAustralia Cell and Tissue Therapies WA(CTTWA) Royal Perth HospitalPerthWAAustralia Adelaide Medical School Faculty of Health and Medical SciencesThe University of AdelaideAdelaideSAAustralia

Delivery of a peptide(APP96-110),derived from amyloid precursor protein(APP),has been shown to elicit neuroprotective effects following cerebral stroke and traumatic brain *** this study,the effect of APP96-110 or a mutant version of this peptide(mAPP96-110)was assessed following moderate(200 kdyn,(2 N))thoracic contusive spinal cord inj.ry(SCI)in adult Nude *** received a single tail vein inj.ction of APP96-110 or mAPP96-110 at 30 minutes post-SCI and were then assessed for functional improvements over the next 8 weeks.A cohort of animals also received transplants of either viable or non-viable human mesenchymal stromal cells(hMSCs)into the SC lesion site at one week post-inj.ry to assess the effect of combining intravenous APP96-110 delivery with hMSC *** were perfused 8 weeks post-SCI and longitudinal sections of spinal cord analyzed for a number of factors including hMSC viability,cyst size,axonal regrowth,glial reactivity and macrophage *** of sensorimotor function revealed occasional significant differences between groups using Ladderwalk or Ratwalk tests,however there were no consistent improvements in functional outcome after any of the ***96-110 alone,and APP96-110 in combination with both viable and non-viable hMSCs significantly reduced cyst size compared to SCI *** treatments with donor hMSCs also significantly increased βIII tubulin^(+),glial fibrillary acidic protein(GFAP^(+))and laminin+expression,and decreased ED1^(+)expression in *** preliminary study demonstrates that intravenous delivery of APP96-110 peptide has selective,modest neuroprotective effects following SCI,which may be enhanced when combined with hMSC ***,the effects are less pronounced and less consistent compared to the protective morphological and cognitive impact that this same peptide has on neuronal survival and behaviour after stroke and traumatic brain *** while the efficacy of a

关键词： amyloid precursor protein cell transplantation combination contusion functional recovery mesenchymal stromal cells neuroprotection regeneration spinal cord inj.ry tissue sparing

Escherichia coli O157:H7 sepsis following fecal microbiota transplant in an IgA-deficient inflammatory bowel disease patient

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Gastroenterology Report 2022年第1期10卷 609-611页

作者： Landen S.Burstiner j.red Silver Logan j.Burstiner Arian Teymoorian Kumar Pallav Demarre j.nes Anna Owings sarah Glover Nova Southeastern University Dr.Kiran C.Patel College of Osteopathic Medicine DavieFLUSA Department of Gastroenterology University of Mississippi Medical CenterJacksonMSUSA Department of Medicine Division of RheumatologyImmunologyand AllergyBrigham and Women’s HospitalHarvard Medical SchoolBostonMAUSA Department of Medicine Memorial Healthcare SystemHollywoodFLUSA Department of Gastroenterology GI Associates&Endoscopy CenterFlowoodMSUSA

Introduction Clostridioides difficile infection(CDI)is a common gastrointestinal illness worldwide,with increased prevalence and worse outcomes in patients with inflammatory bowel disease(IBD)[1].Fecal microbiota transplant(FMT)is an effective treatment for recurrent CDIs(RCDIs)with minimal serious adverse events(SAEs)reported[2].While immunosuppressive medications increase susceptibility to infections,studies have shown that FMT does not increase SAE risk in immunocompromised patients(including IBD patients on immunosuppressive therapy)[3].

关键词： O157:H7 inflammatory patients

Graphene/carbon structured catalyst layer to enhance the performance and durability of the high-temperature proton exchange membrane fuel cells

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j.urnal of Energy Chemistry 2022年第12期75卷 399-407,I0011页

作者： Zhaoqi j. j.anuo Chen Zunmin Guo Ziyu Zhao Rongsheng Cai Maxwell T.P.Rigby sarah j.Haigh Maria Perez-Page Yitao Shen Stuart M.Holmes School of Automotive Engineering Harbin Institute of Technology(Weihai)Weihai 264209ShandongChina Department of Chemical Engineering The University of ManchesterManchester M139PLUK Department of Materials The University of ManchesterManchester M139PLUK

In this study,nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black supported platinum(Pt/Nr EGO_(2)-CB_(3))has been prepared to enhance the performance and durability of hightemperature PEMFCs with lower Pt *** the one hand,Pt/Nr EGO_(2)-CB_(3)with the strong interaction between the Pt and nitrogen(N)prevent agglomeration of Pt particles and Pt particles is 5.46±1.46 nm,which is smaller than that of 6.78±1.34 nm in Pt/***,ECSA of Pt/Nr EGO_(2)-CB_(3)decrease 13.65%after AST,which is much lower than that of 97.99%in Pt/*** the other hand,the Nr EGO flakes in MEAac act as a barrier to mitigate phosphoric acid redistribution,which improves the formation of triple-phase boundaries(TPBs)and gives stable operation of the MEAacwith a lower decay rate of 0.02 mV h^(-1)within100 *** steady-state operation,the maximum power density of Pt/Nr EGO_(2)-CB_(3)(0.411 W cm^(-2))is three times higher than that of conventional Pt/C(0.134 W cm^(-2))in high-temperature *** AST,the mass transfer resistance of Pt/Nr EGO_(2)-CB_(3)electrode(0.560Ωcm^(2))is lower than that in Pt/C(0.728Ωcm^(2)).

关键词： High-temperature proton exchange membrane fuel cell Phosphoric acid loss Pt catalyst degradation Accelerated stress test Durability

Genomewide selection for fruit quality traits in apple: breeding insights gained from prediction and postdiction

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Horticulture Research 2023年第6期10卷 238-249页

作者： sarah A.Kostick Rex Bernardo j.mes j.Luby Department of Horticultural Science University of MinnesotaSaint PaulMN 55108USA Department of Agronomy and Plant Genetics University of MinnesotaSaint PaulMN 55108USA

Many fruit quality traits in apple(Malus domestica Borkh.)are controlled by multiple small-effect quantitative trait loci(QTLs).Genomewide selection(genomic selection)might be an effective breeding approach for highly quantitative traits in woody perennial crops with long generation times like *** goal of this study was to determine if genomewide prediction is an effective breeding approach for fruit quality traits in an apple scion breeding *** apple scion breeding germplasm(nindividuals=955),high-quality single nucleotide polymorphism(SNP)data(nSNPs=977),and breeding program fruit quality trait data at harvest were *** parents‘Honeycrisp’and‘Minneiska’were highly *** to high predictive abilities were observed for most fruit quality traits at *** example,when 25%random subsets of the germplasm set were used as training sets,mean predictive abilities ranged from 0.35 to 0.54 across ***,training and test sets,family size for within family prediction,and number of SNPs per chromosome affected model predictive *** of large-effect QTLs as fixed effects resulted in higher predictive abilities for some traits(*** red overcolor).Postdiction(***)analyses demonstrated the impact of culling threshold on selection *** results of this study demonstrate that genomewide selection is a useful breeding approach for certain fruit quality traits in apple.

关键词： breeding germplasm crops