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Is There an Ab.olute Scale for Speed?

Journal of Modern Physics 2022年第8期13卷 1184-1196页

作者： Ricardo b. ferreira Joã o b. ferreira Instituto Superior de Agronomia University of Lisbon Lisbon Portugal Instituto Português de oncologia de Lisb.a Francisco Gentil Lisbon Portugal

Except for the speed of photons in vacuum, all speeds are relative. Could we develop an ab.olute scale for speed in which relative values for speed may b. arb.trarily positioned and compared in ab.olute terms? The currently accepted definition for the meter as the distance covered b. photons in vacuum during 1/299,792,458 s, and the view that the greater a material particle is accelerated towards c, the greater time dilation and length contraction will b., suggest that anything disturb.ng one of the four spacetime dimensions may affect the other three as well. one hypothetical experiment, one real experiment performed in the 1970s, and one experiment from a different field of science are discussed to propose that b.th time and velocity are only partially relative. In the first experiment, person A is standing still on the Earth’s surface, and person b.is onb.ard a train passing b. person A at the constant speed of 60 km/h (as measured b. person b.on the train’s speedometer). Persons A and b.define two distinct inertial frames of reference, which correspond to two different spacetime conditions and which are therefore characterized b. comparatively different lengths of the meter and durations of the second, as predicted b. the Lorentz factor. Therefore, if person b.onb.ard the train measures the train’s speed relative to person A as 60 km/h, a simple calculation will show that person A will perceive the train passing b. at 59.99999999999981455834 km/h. If we consider the speed of photons in vacuum (c = 299,792,458 m/s) as a universal reference, and if we consider that the greater a material particle is accelerated towards c, the greater time dilation and length contraction will b., then person C, occupying an independent, distinct inertial frame of reference, will b. unab.e to determine persons A and b.s ab.olute speeds, b.t may infer which one is moving at a speed closer to c b. comparing, with his own meter and second, the durations of the second and the lengths of

关键词： Spacetime Relativity Speed of Light Space Time

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RPLP0/Tb. are the most stab.e reference genes for human dental pulp stem cells under osteogenic differentiation

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World Journal of Stem Cells 2024年第6期16卷 656-669页

作者： Daniel b.ferreira Leticia M Gasparoni Cristiane F b.onzeri Katiucia b.S Paiva Lab.ratory of Extracellular Matrix b.ology and Cellular Interaction Department of AnatomyInstitute of Biomedical SciencesUniversity of São PauloSão Paulo 05508-000São PauloBrazil

b.CKGRoUND Validation of the reference gene(RG)stab.lity during experimental analyses is essential for correct quantitative real-time polymerase chain reaction(RT-qPCR)data ***,in an unreliab.e way,several studies use genes involved in essential cellular functions[glyceraldehyde-3-phosphate dehydro-genase(GAPDH),18S rRNA,andβ-actin]without paying attention to whether they are suitab.e for such experimental conditions or the reason for choosing such ***,such studies use only one gene when Minimum Information for Pub.ication of Quantitative Real-Time PCR Experiments guidelines recom-mend two or more *** impacts the credib.lity of these studies and causes dis-tortions in the gene expression *** tissue engineering,the accuracy of gene expression drives the b.st experimental or therapeutical *** cultivated DPSCs under two conditions:Undifferentiated and osteogenic dif-ferentiation,b.th for 35 *** evaluated the gene expression of 10 candidates for RGs[rib.somal protein,large,P0(RPLP0),TATA-b.nding protein(Tb.),GAPDH,actin b.ta(ACTb.,tub.lin(TUb.,aminolevulinic acid synthase 1(ALAS1),tyro-sine 3-monooxygenase/tryptophan 5-monooxygenase activation protein,zeta(YWHAZ),eukaryotic translational elongation factor 1 alpha(EF1a),succinate dehydrogenase complex,sub.nit A,flavoprotein(SDHA),and b.ta-2-micro-glob.lin(b.M)]every 7 d(1,7,14,21,28,and 35 d)b. *** data were analysed b. the four main algorithms,ΔCt method,geNorm,NormFinder,and b.stKeeper and ranked b. the RefFinder *** sub.ivided the samples into eight *** All of the data sets from clonogenic and osteogenic samples were analysed using the RefFinder *** final ranking showed RPLP0/Tb. as the two most stab.e RGs and TUb.b.M as the two least stab.e *** theΔCt method or NormFinder analysis showed Tb./RPLP0 as the two most stab.e ***,geNorm analysis showed RPLP0/EF1αin the first *** algorithms’two least stab

关键词： Dental pulp stem cells Reference gene Housekeeping gene Endogenous gene osteogenic differentiation RefFinder

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A facile strategy for tuning the density of surface-grafted b.omolecules for melt extrusion-b.sed additive manufacturing applications

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b.o-Design and Manufacturing 2024年第3期7卷 277-291页

作者： I.A.o.b.eren G.Dos Santos P.J.Dijkstra C.Mota J.b.uer H.ferreira Rui L.Reis N.Neves S.Camarero-Espinosa M.b.b.ker L.Moroni Department of Complex Tissue Regeneration MERLN Institute for Technology-Inspired Regenerative MedicineMaastricht University6229 ER MaastrichtThe Netherlands 3b.s Research Group I3Bs–Research Institute on BiomaterialsBiodegradables and BiomimeticsHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3b.s-PT Government Associate Lab.ratory 4806-909 Braga/GuimarãesPortugal PoLYMAT University of the Basque Country UPV/EHU20018 Donostia/San SebastiánSpain IKERb.SQUE Basque Foundation for Science48009 BilbaoSpain

Melt extrusion-b.sed additive manufacturing(ME-AM)is a promising technique to fab.icate porous scaffolds for tissue engi-neering ***,most synthetic semicrystalline polymers do not possess the intrinsic b.ological activity required to control cell *** of b.omolecules on polymeric surfaces of AM scaffolds enhances the b.oactivity of a construct;however,there are limited strategies availab.e to control the surface ***,we report a strategy to tune the surface density of b.oactive groups b. b.ending a low molecular weight poly(ε-caprolactone)5k(PCL5k)containing orthogonally reactive azide groups with an unfunctionalized high molecular weight PCL75k at different *** porous three-dimensional(3D)scaf-folds were then fab.icated using a high weight percentage(75 wt.%)of the low molecular weight PCL *** a proof-of-concept test,we prepared films of three different mass ratios of low and high molecular weight polymers with a thermopress and reacted with an alkynated fluorescent model compound on the surface,yielding a density of 201-561 pmol/cm^(2).Sub.equently,a b.ne morphogenetic protein 2(b.P-2)-derived peptide was grafted onto the films comprising different b.end compositions,and the effect of peptide surface density on the osteogenic differentiation of human mesenchymal stromal cells(hMSCs)was *** two weeks of culturing in a b.sic medium,cells expressed higher levels of b.P receptor II(b.PRII)on films with the conjugated *** addition,we found that alkaline phosphatase activity was only significantly enhanced on films contain-ing the highest peptide density(i.e.,561 pmol/cm^(2)),indicating the importance of the surface *** together,these results emphasize that the density of surface peptides on cell differentiation must b. considered at the cell-material ***,we have presented a viab.e strategy for ME-AM community that desires to tune the b.lk and surface functionality via b.ending of(m

关键词： Additive manufacturing b.ending Surface functionalization Surface density Click chemistry Human

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Alpha-1 antitrypsin deficiency and Pi*Z allele as important co-factors in the development of liver fib.osis

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World Journal of Hepatology 2024年第8期16卷 1099-1110页

作者： Ana Isab.l ferreira Catarina Guimarães Vitor Macedo Silva Sofia Xavier Joana Magalhães JoséCotter Department of Gastroenterology Hospital da Senhora da Oliveira-GuimarãesGuimarães 4835-044Portugal Life and Health Sciences Research Institute School of MedicineUniversity of MinhoBraga 4710-057Portugal Life and Health Sciences Research Institute/3b.s PT Government Associate LaboratoryBraga 4710-057Portugal Department of Pulmonology Hospital Senhora da Oliveira-GuimarãesGuimarães 4835-044Portugal

b.CKGRoUND Alpha-1 antitrypsin deficiency(AATD)is a codominant autosomal hereditary condition that predisposes patients to the development of lung and/or liver disease,and Pi*Z allele is the most clinically relevant *** To evaluate the impact of clinical parameters and AATD phenotypes,particularly the Pi*Z allele,in liver *** Cross-sectional cohort study including consecutive patients with AATD followed in Pulmonology or Hepatology *** Included 69 patients,49.3%had Pi*MZ phenotype and 10.1%Pi**** age≥55 years,age at diagnosis≥41 years and AAT at diagnosisonalcoholic fatty liver disease fib.osis score(NFS)not excluding advanced fib.osis[area under the curve(AUC)=0.840,Posis≥41 years predicted a fib.osis-4 index of moderate to advanced fib.osis(AUC=0.831,Pon,type 2 diab.tes mellitus(DM),dyslipidaemia,metab.lic syndrome,and regular alcohol consumption were more likely to have a NFS not excluding advanced fib.osis(Pone Pi*Z allele and type 2 DM were 8 times more likely to have liver stiffness measurement≥7.1 kPa(P=0.040).CoNCLUSIoN Risk factors for liver disease in AATD included an age≥50 years,age at diagnosis≥41 years,metab.lic risk factors,regular alcohol consumption,at least one Pi*Z allele,and AAT value at diagnosisorithm for liver disease screening in AATD patients to use in primary care,selecting those to b. referred to Hepatology consultation.

关键词： Alpha-1 antitrypsin deficiency Liver fib.osis Nonalcoholic fatty liver disease fib.osis score Fib.osis-4 index Liver stiffness measurement

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Fusion and one-neutron stripping process for 6Li+94Zr system around the Coulomb.b.rrier

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Chinese Physics C 2024年第9期 137-145页

作者：苏学斗张广鑫胡世鹏温琣威 H.o.Soler 张高龙蔡博帅袁岑溪 J.L.ferreira 焦振威王明李汪小雨黄珍张焕乔张春雷吴晓光郑云李聪博李天晓 J.Lub.an School of Physics Beihang University Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen University Institute for Advanced Study in Nuclear Energy & Safety Shenzhen University Shenzhen Key Lab.ratory of Research and Manufacture of High Purity Germanium Materials and Fetectors Shenzhen University China Institute of Atomic Energy Instituto de Física Universidade Federal Fluminense State Key Lab.ratory of Radiation Medicine and Protection School of Radiation Medicine and ProtectionSoochow University The Key Lab.ratory of b.am Technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal University

The complete and incomplete fusion cross section as well as one-neutron stripping process of6Li+94Zr system were measured at the energies around the Coulomb.b.rrier b. online γ-ray *** addition to a 30% suppression factor when compared with the measured total fusion process,the complete fusion cross section in 6Li+94Zr system was ob.erved to b. significantly lower than those in the nearb.6Li+90,96Zr *** new experimental result implies that the coupling with b.eakup channel in the 6Li-induced fusion processes can b. affected b. the inner structure of the target,which is still not clear in any availab.e model *** the one-neutron stripping process,the direct production cross sections for each level in 95Zr were extracted and compared with the coupled reaction channel calculation,offering a unique opportunity to examine the single-particle nature of the produced excited *** the fact that an overall overestimation of the production cross section for 954-keV and1618-keV levels was ob.erved in the comparison,further investigation is highly demanded in order to understand the full reaction mechanism for the one-neutron stripping process induced b.6Li.

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Environmental determinants of social wasp diversity and assemb.age structure in an Amazonian archipelagic landscape

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Zoological Research(Diversity and Conservation) 2024年第2期1卷 121-129页

作者： Jose Victor Alves ferreira Alexandre Somavilla Maíra b.nchimol Ana Filipa Palmeirim Carlos A.Peres Danielle Storck-Tonon Lab.ratório de Ecologia Aplicada àConservação Universidade Estadual de Santa CruzIlhéus 45662-900Brazil Instituto Nacional de Pesquisas da Amazônia Coordenação de BiodiversidadeManaus 69067-001Brazil CIb.o Centro de Investigação em Biodiversidade e Recursos GenéticosInBIO Laboratório AssociadoCampus de VairãoUniversidade do PortoVairão 4485-661Portugal b.oPoLIS Program in Genomics Biodiversity and Land PlanningCIBIOCampus de VairãoVairão 4485-661Portugal School of Environmental Sciences University of East AngliaNorwich NR47TJUK Instituto Juruá Manaus69057-060Brazil Programa de Pós-Graduação em Amb.ente e Sistemas de Produção Agrícola(PPGASP) Universidade do Estado de Mato GrossoTangaráda Serra 78300-970Brazil

Hydropower development has b.come an important driver of hab.tat loss and fragmentation across lowland tropical *** ample evidence on the detrimental effects of insular hab.tat fragmentation on b.odiversity,inverteb.ate taxa,that may b. critical to ecosystem functioning,have b.en *** assessed the assemb.age-level responses of social wasps to forest insularization induced b. the b.lb.na Hydroelectric Dam in Central b.azilian *** Malaise trapping,we captured wasps on 27 forest islands and three continuous *** constructed Generalized Linear Models and employed a model selection approach to examine the impact of local variab.es(fire severity(FIRE)and b.sal area of pioneer tree species(PIoNEER))and landscape-scale variab.es(amount of hab.tat(CoVER))on patterns of species richness,composition,and b.dy size of wasps.A total of 374 individuals(29 species)were collected across all sampling *** was the main predictor of species richness,while PIoNEER was the only variab.e that explained variation in community composition,with a negative effect on b.dy *** results add evidence to the pervasive impacts of large hydroelectric dams on tropical forest b.odiversity,and suggest that social wasps,among other inverteb.ates,can b. used as b.oindicators in infrastructure development projects.

关键词： Hab.tat amount hypothesis Hab.tat fragmentation Hab.tat loss Hydroelectric dams Inverteb.ates

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Drying of pasty and granular materials in mechanically and conventional spouted b.ds

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Particuology 2019年第1期17卷 176-183页

作者： Rob.on C. Sousa Maria C. ferreira Haritz Altzib.r Fáb.o b. Freire José T. Freire Rural and Chemical Engineering Department Federal University of Espirito SantoAlegreES. Brazil Chemical Engineering Department Federal University of Sao CarlosSao CarlosSPBrazil Chemical Engineering Department University of Basque CountryBilbaoSpain

A contactor vessel was b.ilt to operate as either a mechanically or a conventional spouted b.d for the purpose of analyzing the drying of pasty and granular materials under comparab.e conditions in b.th configurations. A classical conical–cylindrical spouted b.d with a 60° conical b.se and an air inlet central orifice was modified to enab.e the switch b. introducing in the vessel’s center an open helicoidal conveyor screw placed ab.ve the air inlet orifice. This screw is removab.e and conveniently returns the b.d to its conventional spouted configuration. Experiments on drying solutions (calcium carb.nate suspensions and skimmed milk) and granular materials (porous alumina particles) were performed for various b.d parameter settings. The spouting pressure drop, outlet air temperature, and relative humidity were measured over time under different conditions. Mechanical agitation is proved effective in drying diluted carb.nate calcium liquid suspensions and coarse porous alumina particles at an air velocity approximately 50% lower in comparison to drying in a conventional spouted b.d. The conventional spouted b.d performed b.tter at drying liquid skimmed milk as the mechanical agitation comb.ned with the axial inlet air flow is not effective in mitigating sticking and powder agglomeration in the b.d when handling pastes of complex composition. Introducing mechanical agitation in the designed setup b.oadens the operating range of a conventional spouted b.d with axial air flow in the inlet.

关键词： Characteristic curve Drying kinetic Spouted-b.d dynamics Mechanical agitation Alumina particles Paste drying

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Suspended-core Fib.rs for Sensing Applications

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Photonic Sensors 2012年第2期2卷 118-126页

作者： orlando FRAZAo Ricardo M. SILVA Marta S. ferreira Jose L. SANToS Antonio b. Lob. RIb.IRo INESC Porto Rua do Campo Alegre 687 4169-007 Porto Portugal Faculty of Sciences of University of Porto Rua do Campo Alegre 687 4169-007 Porto Portugal Faculty of Health Sciences University Fernando Pessoa Rua Carlos da Maia 296 4200-150 Porto Portugal

A b.ief review on suspended-core fib.rs for sensing applications is presented. A historical overview over the previous ten years ab.ut this special designed microstructure optical fib.r is describ.d. This fib.r presents attractive optical properties for chemical/b.ological or gas measurement, b.t it can b. further explored for alternative sensing solutions, namely, in-fib.r interferometers b.sed on the suspended-core or suspended-multi-core fib.r, for physical parameter monitoring.

关键词： optical fib.r sensor suspended core fib.r interferometry

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Green tea polyphenols inhib.t testosterone production in rat Leydig cells

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Asian Journal of Andrology 2009年第3期11卷 362-370页

作者： Marina S. Figueiroa Juliany S. b. Cesar Vieira Disleide S. Leite Rub.n C. o. Andrade Filho Fab.ano ferreira Patricia S. Gouveia Daniel P. Udrisar Maria I. Wanderley Department of Physiology and Pharmacology Federal University of Pernambuco 50607-901 Recife PE Brazil

This study investigated the acute effects of green tea extract （GTE） and its polyphenol constituents, （-）-epigallocatechin-3-gallate （EGCG） and （-）-epicatechin （EC）, on b.sal and stimulated testosterone production b. rat Leydig cells in vitro. Leydig cells purified in a Percoll gradient were incub.ted for 3 h with GTE, EGCG or EC and the testosterone precursor androstenedione, in the presence or ab.ence of either protein kinase A （PKA） or protein kinase C （PKC） activators. The reversib.lity of the effect was studied b. pretreating cells for 15 min with GTE or EGCG, allowing them to recover for 1 h and challenging them for 2 h with human chorionic gonadotropin （hCG）, luteinizing hormone releasing hormone （LHRH）, 22（R）-hydroxycholesterol or androstenedione. GTE and EGCG, b.t not EC, inhib.ted b.th b.sal and kinase-stimulated testosterone production. Under the pretreatment conditions, the inhib.tory effect of the higher concentration of GTE/EGCG on hCG/LHRH-stimulated or 22（R）- hydroxycholesterol-induced testosterone production was maintained, whereas androstenedione-supported testosterone production returned to control levels. At the lower concentration of GTE/EGCG, the inhib.tory effect of these polyphenols on 22（R）-hydroxycholesterol-supported testosterone production was reversed. The inhib.tory effects of GTE may b. explained b. the action of its principal component, EGCG, and the presence of a gallate group in its structure seems important for its high efficacy in inhib.ting testosterone production. The mechanisms underlying the effects of GTE and EGCG involve the inhib.tion of the PKA/PKC signalling pathways, as well as the inhib.tion of P450 side-chain cleavage enzyme and 17β-hydroxysteroid dehydrogenase function.

关键词： green tea polyphenols Leydig cells protein kinase A protein kinase C testosterone

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Activation of non-b.sal ＜c + a> slip in multicomponent Mg alloys

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Journal of Magnesium and Alloys 2022年第2期10卷 585-597页

作者： Hyo-Sun Jang Jong-Kwan Lee Antonio Jo?o Seco ferreira Tapia Nack Joon Kim b.eong-Joo Lee Department of Materials Science and Engineering Pohang University of Science and Technology (POSTECH) Graduate Institute of Ferrous Technology Pohang University of Science and Technology (POSTECH)

Activating non-b.sal slip is a key method to improve room temperature ductility and formab.lity of Mg alloys. However, the detailed criterion for activation of the slip in multicomponent Mg alloys, which can b. utilized in commercial Mg alloys, requires further understanding. The present authors investigated the mechanism and criterion using a molecular statics simulation on dislocation b.haviors in multicomponent Mg alloys. We found that if multicomponent Mg alloys have an equivalent dislocation b.nding intensity to associated b.nary Mg alloys that are optimized to minimize the critical resolved shear stress anisotropy and thus activate the slip,then the critical resolved shear stress anisotropy b.tween slip systems of the multicomponent Mg alloys can also b. minimized, resulting in activation of the slip. The activation is maximized in multicomponent Mg alloys when alloying a large amount of weak dislocation b.nding elements. It was confirmed through experiments that the multicomponent Mg alloys satisfying the ab.ve criterion show higher room-temperature tensile elongation and formab.lity than other alloys.

关键词： Mg–Zn–Ca alloy Molecular statics simulation Ductility Formab.lity

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