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Role of vitamin B_(12) on methylmalonyl-CoA mutase activity

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第6期13卷 423-437页

作者： tóshiko takahashi-iiguez Enrique GARCíA-HERNANDEZ Roberto ARREGUíN-ESPiNOSA María Elena FLORES Department of Molecular Biology and Biotechnology Institute of Biomedical ResearchNational Autonomous University of MexicoD.F.04510Mexico Department of Chemistry of Biomacromolecules Institute of ChemistryNational Autonomous University of MexicoD.F.04510Mexico

Vitamin B 12 is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes,which have been grouped into three subfamilies depending on their *** them,methylmalonyl-CoA mutase (MCM) has been extensively *** enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the *** crystal structure of MCM determined in Propionibacterium freudenreichii *** has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme,coenzyme,and *** existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in *** recent crystallization of the human MCM has shown that despite being similar to the bacterial protein,there are significant differences in the structural organization of the two *** studies have identified the involvement of an accessory protein called MMAA,which interacts with MCM to prevent MCM's inactivation or acts as a chaperone to promote regeneration of inactivated *** interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase,the impact of mutations at a functional level and their repercussion in the development and progression of MMA in *** is still necessary to study the mechanisms involved in more detail using new methods.

关键词： Vitamin B 12 Methylmalonyl-CoA mutase (MCM) MMAA MeaB Methylmalonic academia (MMA) Protectase Reactivase

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Arctic sea-ice extent: No record minimum in 2023 or recent years

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola M.Johannessen tor i.Olaussen Nansen Scientific Society BergenNorway Nansen Environmental and Remote Sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers(***^(2)). this was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. in general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.

关键词： Sea ice Arctic Minimum ice Climate

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Coarse to Fine: the Role of Severe Plastic Deformation in Advancing titanium-Based Medical implants - A Comprehensive Review

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Journal of Wuhan University of technology(Materials Science) 2025年第1期40卷 295-306页

作者： Dragana R Mihajlović Bojan i Međo ivana Lj Cvijović-Alagić Veljko R Djokić Faculty of technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia Vinča institute of Nuclear Sci-ences-National institute of the Republic of Serbia University of Belgrade11001BeogradSerbia innovation Centre of the Faculty of technology and Metallurgy Karnegijeva 411120 BelgradeSerbia

this paper describes severe plastic deformation(SPD)procedures,which are utilized to form an ultrafine-grained structure in metallic *** the SPD process,a solid material sample is subjected to very high loads without a significant change in sample *** the present work,the high-pressure torsion(HPt)process,as one of the SPD techniques,which achieves a high degree of deformation and ensures refinement of the microstructure,will be discussed in more *** that grain size control is accepted as a method to obtain materials with desired characteristics,an overview of the properties of ultrafine-grained titanium-based biomaterials to be used in medicine is ***,particular attention is dedicated to the influences of HPt process parameters,primarily hydrostatic pressure,and number of revolutions during torsion,on the grain size and physical and mechanical characteristics(modulus of elasticity,microhardness,and tensile properties),corrosion resistance,and biocompatibility of the titanium-based biomaterials.A review of the literature indicates that titanium-based materials obtained by the SPD process show improved mechanical and physical properties without losing biocompatibility and corrosion resistance,which suggests that these methods of obtaining implants are something that should be further developed in the future.

关键词： high-pressure torsion process ultrafine-grained titanium-based materials electrochemical anodization physical properties mechanical properties

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Creating multiferroic and conductive domain walls in common ferroelastic compounds

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npj Computational Materials 2019年第1期5卷 332-338页

作者： Hong Jian Zhao JorgeÍñiguez Materials Research and technology Department Luxembourg Institute of Science and Technology(LIST)Avenue des Hauts-Fourneaux 5L-4362 Esch/AlzetteLuxembourg Physics and Materials Science Research Unit University of LuxembourgRue du Brill 41L-4422 BelvauxLuxembourg Physics Department and institute for Nanoscience and Engineering University of ArkansasFayettevilleAR 72701USA

Domain walls in ferroelectrics and ferroelastics often present peculiar functional properties,offering an intriguing route toward the design of *** we use first-principles simulations to illustrate an approach for engineering such walls,working with representative ferroelastic perovskites LaGaO_(3) and CatiO_(3)(insulating,non-magnetic,non-polar).We show that a wide range of substitutional dopants can be used to create long-range-ordered structures confined within the walls of these compounds,yielding functional interfaces with tailor-made *** thus identify clear-cut strategies to produce metallic walls within an insulating ***,we find ways to create magnetic walls that also display ferroelectric order(proper or improper),thus providing an original route to obtain magnetoelectric *** the recent developments on the preparation of high-density domain structures in perovskite films,our results suggest a definite path toward new functional nano-materials.

关键词： properties. walls perovskite

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On the possibility that PbZrO_(3) not be antiferroelectric

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npj Computational Materials 2021年第1期7卷 1812-1821页

作者： Hugo Aramberri Claudio Cazorla Massimiliano Stengel Jorge Íñiguez Materials Research and technology Department Luxembourg Institute of Science and Technology5 Avenue des Hauts-FourneauxL-4362 Esch/AlzetteLuxembourg Departament de Física Universitat Politècnica de CatalunyaCampus Nord B4-B5Barcelona 08034Spain institut de Ciència de Materials de Barcelona(iCMAB-CSiC) Campus UAB08193 BellaterraSpain iCREA-institucióCatalana de Recerca i Estudis Avançats 08010 BarcelonaSpain Department of Physics and Materials Science University of Luxembourg41 Rue du BrillBelvaux L-4422Luxembourg

Lead zirconate(PbZrO_(3))is considered the prototypical antiferroelectric material with an antipolar ground ***,several experimental and theoretical works hint at a partially polar behaviour in this compound,indicating that the polarization may not be completely *** this work,we propose a simple ferrielectric structure for lead ***-principles calculations reveal this state to be more stable than the commonly accepted antiferroelectric phase at low temperatures,possibly up to room temperature,suggesting that PbZrO_(3)may not be antiferroelectric at ambient *** discuss the implications of our discovery,how it can be reconciled with experimental observations and how the ferrielectric phase could be obtained in practice.

关键词： ferroelectric ambient phase

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Comparison of Air Pollution−Mortality Associations Using Observed Particulate Matter Concentrations and Reanalysis Data in 33 Spanish Cities

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Environment & Health 2024年第3期2卷 161-169页

作者： Dominic Royé Carmen íñiguez Aurelio tobías Climate Research Foundation 28003 MadridSpainSpanish Consortium for Research on Epidemiology and Public Health(CIBERESP)28029 MadridSpain institute of Environmental Assessment and Water Research(iDAEA) Spanish Council for Scientific Research(CSIC)08034 BarcelonaSpain

Air pollution poses a health hazard in all ***,complete data on ambient particulate matter(PM)concentrations are not available in all world *** data is already a valuable source of exposure data in epidemiological studies examining the relationship between temperature and ***,the performance of reanalysis data in assessing the short-term health effects of particulate air pollution remains *** assessed the performance of CAMS reanalysis(EAC4)data from the European Centre for Medium-Range Weather Forecasts,compared with daily PM concentrations from field monitoring stations,to estimate short-term exposure to PM with an aerodynamic diameter less than 10μm(PM_(10))on daily mortality in 33 Spanish provincial capital cities using a two-stage time series regression *** shape of the PM_(10)distribution varied substantially between PM observations and CAMS global reanalysis of atmospheric composition(EAC4)reanalysis data,with correlation ranging from 0.21 to *** pooled mortality risk for a 10μg/m^(3)increase in PM_(10)showed similar estimates using PM concentrations{relative risks(RR)=1.007,95%confidence intervals(95%Ci)=[1.002,1.011]}and EAC4 reanalysis data(RR=1.011,95%Ci=[1.006,1.015]).However,the city-specific PM_(10)beta coefficients estimated using PM concentrations and EAC4 reanalysis data showed a low correlation(r=0.22).the use of reanalysis data should be approached with caution when assessing the association between particulate matter air pollution and health outcomes,particularly in cities with small populations.

关键词： Air pollution particulate matter PM_(10) reanalysis EAC4 mortality Spain time series regression

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Giant multiphononic effects in a perovskite oxide

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npj Computational Materials 2023年第1期9卷 1352-1358页

作者： Claudio Cazorla Massimiliano Stengel JorgeÍñiguez Riccardo Rurali Departament de Física Universitat Politècnica de CatalunyaCampus Nord B4-B5Barcelona 08034Spain institut de Ciència de Materials de Barcelona ICMAB–CSICCampus UAB08193 BellaterraSpain iCREA-institucióCatalana de Recerca i Estudis Avançats 08010 BarcelonaSpain Materials Research and technology Department Luxembourg Institute of Science and Technology(LIST)Avenue des Hauts-Fourneaux 5L-4362 Esch/AlzetteLuxembourg Department of Physics and Materials Science University of Luxembourg41 Rue du BrillL-4422 BelvauxLuxembourg

Perovskite oxides offer tremendous potential for applications in information storage and energy conversion,owing to a subtle interplay between their spin,charge,orbital and lattice degrees of ***,we further expand the possible range of perovskite oxides operation towards the fields of thermal management and thermal computing by exploiting an exceptional synergy between different ferroic *** propose dynamical control of the heat flow in a distinctive family of perovskite oxides obtained via the application of small electric(~10 kV/cm)and/or magnetic(~1 t)*** on first-principles simulations,we predict a relative heat conductivity variation of~100%in SrMnO_(3) thin films near room temperature resulting from a phase transition that involves huge changes in both the magnetization and electric *** disclosed giant multiphononic effects are fundamentally caused by anharmonic spin-phonon couplings that strongly influence the mean lifetime of phonons.

关键词： perovskite oxides exceptional

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Bleeding risk assessment in elderly patients with acute coronary syndrome

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Journal of Geriatric Cardiology 2019年第2期16卷 145-150页

作者： Lucía Riobóo-Lestón Sergio Raposeiras-Roubin Emad Abu-Assi Andrés i?iguez-Romo Department of Cardiology University Hospital álvaro Cunqueiro

Nowadays,elderly people represent a growing population segment with a well known increased risk of both ischemic and bleeding *** acute coronary syndrome guidelines,strongly recommend dual antiplatelet therapy(DAPt)with few specific references for aged patients due to lack of *** aged>75 years are misrepresented in the classic derivation trials *** to reduce the bleeding risk in this group of patients are urgently needed for the daily clinical *** the specific age related bleeding risk factors and the importance of an integral geriatric assessment remains *** of the available in-hospital and out-hospital bleeding risk scores have shown a lower to moderate predictive ability in older patients and no specific tools are developed in elderly *** importance of an appropriate vascular access choice,type and duration of antiplatelet drugs is crucial to reduce the bleeding *** radial approaches and short DAPt duration leads to reduce *** interesting subgroup of patients is those who need chronic anticoagulation therapy after percutaneous coronary intervention,due to their very high risk of *** alternatives as dual therapy with oral anticoagulation and only one antiplatlet drug should be *** current review,we evaluate the available evidence about bleeding risk in elderly.

关键词： Acute coronary syndrome Bleeding risk Dual antiplatelet treatment Elderly patients

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Multisensory mechanisms of gait and balance in Parkinson’s disease:an integrative review

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Neural Regeneration Research 2025年第1期20卷 82-92页

作者： Stiven Roytman Rebecca Paalanen Giulia Carli Uros Marusic Prabesh Kanel teus van Laar Nico i.Bohnen Department of Radiology University of MichiganAnn ArborMIUSA Department of Neurology University of MichiganAnn ArborMIUSA Morris K.Udall Center of Excellence for Parkinson’s Disease Research University of MichiganAnn ArborMIUSA institute for Kinesiology Research Science and Research Centre KoperKoperSlovenia Department of Health Sciences Alma Mater Europaea–ECMMariborSlovenia Parkinson’s Foundation Research Center of Excellence University of MichiganAnn ArborMIUSA Department of Neurology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands Neurology Service and GRECC VA Ann Arbor Healthcare SystemAnn ArborMIUSA

Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging *** and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous *** effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory *** mechanisms which underpin the integration of these multisensory signals are the principal topic of the present *** multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older *** emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and *** the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s *** also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older ***,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.

关键词： aging balance encephalography functional magnetic resonance imaging gait multisensory integration Parkinson’s disease positron emission tomography somatosensory vestibular visual

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Apolipoprotein A-i binding protein-mediated neuroprotection in glaucomatous neuroinflammation and neurodegeneration

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Neural Regeneration Research 2025年第5期20卷 1414-1415页

作者： Sinwoo Hwang Seunghwan Choi Soo-Ho Choi Keun-Young Kim Yury i.Miller Won-Kyu Ju Hamilton Glaucoma Center and Shiley Eye institute The Viterbi Family Department of OphthalmologyUniversity of California San DiegoLa JollaCAUSA Department of Medicine University of California San DiegoLa JollaCAUSA National Center for Microscopy and imaging Research Department of NeurosciencesUniversity of California San DiegoLa JollaCAUSA

Glaucoma is a multifactorial eye disorder that can cause vision loss and irreversible blindness,affecting individ uals aged 40 to 80 yea rs *** to the aging population,it is expected that the number of people affected by glaucoma will surpass 111 million by 2040 as the disease becomes more *** primarily contributes to optic nerve axon loss and the progressive degeneration of retinal ganglion cells (RGCs),subsequently leading to vision impairment.

关键词： irreversible pass primarily

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