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Oxidative dissolution of Cr(OH)_(3) and mixed Fe-Cr(Ⅲ)phases by aqueous mn(Ⅲ)-pyrophosphate complex

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Journal of Environmental Sciences 2024年第5期139卷 105-113页

作者： mismel Ruiz-garcia Jordan Stanberry Giovanna Ballerini Ribeiro Vasileios Anagnostopoulos Department of Chemistry University of Central FloridaOrlando FL 32816USA

The key role of manganese(mn)in the biogeochemical cycle of trace elements has been of great interest in recent years.Nevertheless,the redox properties of aqueous mn(Ⅲ)have been studied to a lesser extent.mn(Ⅲ)is not stable in solution by itself.However,when complexed with inorganic ligands,it has shown potential to oxidize and reduce trace elements.In the present study,we are exploring the redox characteristics of the complex mn(Ⅲ)-Pyrophosphate(mn(Ⅲ)-PP).This complex is stable over a wide range of pH values but requires the ratio of mn:PP to be less than 1:6.Specifically,the redox reaction of chromium(Cr(Ⅲ))and mn(Ⅲ)-PP is investigated.A solid,Cr(OH)_(3),is used as a source of Cr(Ⅲ).For this reaction,environmentally relevant parameters,such as pH,ionic strength,ratio mn(Ⅲ)/Cr(Ⅲ),and excess of ligand,were assessed.Results showed that mn(Ⅲ)can effectively oxidize Cr(Ⅲ)to Cr(Ⅵ),taking about 15 days for the reaction to complete.This reaction occurs only under acidic conditions(pH4),and with a low excess of Pyrophosphate.The initial mn(Ⅲ)concentration decreases as the Cr(Ⅵ)is produced,and Cr(Ⅵ)can be adsorbed back into the Cr(OH)_(3)surface,limiting the mobility of this toxic species.Despite this adsorption,significant amounts of Cr(VI)are release in the aqueous phase.This study shows the importance of a mobile species(mn-PP complex)in the oxidation of Cr(Ⅲ)and the release of Cr(Ⅵ)to the environment.

关键词： Chromium manganese Pyrophosphate complex Sorption Ionic strength Redox

Early anticoagulation in patients with stroke and atrial fibrillation is associated with fewer ischaemic lesions at 1 month: the ATTUNE study

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Stroke & Vascular Neurology 2024年第1期9卷 30-37,I0034页

作者： Angelos Sharobeam Longting Lin Christina Lam Carlos garcia-Esperon Yash Gawarikar Ronak Patel matthew Lee-Archer Andrew Wong michael Roizman Amanda Gilligan Andrew Lee Kee meng Tan Susan Day Christopher Levi Stephen m Davis mark Parsons Bernard Yan melbourne Brain Centre at Royal melbourne Hospital ParkvilleVictoriaAustralia University of New South Wales South Western Sydney Clinical School LiverpoolNew South WalesAustralia Department of Neurology John Hunter HospitalNewcastleNew South WalesAustralia Department of Neurology Calvary Public HospitalCanberraAustralian Capital TerritoryAustralia Department of Neurology Northern Hospital EppingEppingVictoriaAustralia Department of Neurology Royal Brisbane and Women's HospitalHerstonQueenslandAustralia The University of Queensland School of medicine HerstonQueenslandAustralia Neurosciences Clinical Institute Epworth HealthcareRichmondVirginiaAustralia Department of Neurology Austin HealthUniversity of MelbourneHeidelbergVictoriaAustralia Flinders University College of medicine and Public Health AdelaideSouth AustraliaAustralia Department of Neurology Gold Coast University HospitalSouthportQueenslandAustralia The University of Sydney Northern Clinical School St LeonardsNew South WalesAustralia Department of Neurology and Neurophysiology Liverpool HospitalLiverpoolNew South WalesAustralia

Background The optimal time to commence anticoagulation in patients with atrial fibrillation(AF)after ischaemic stroke or transient ischaemic attack(TIA)is unclear,with guidelines differing in recommendations.A limitation of previous studies is the focus on clinically overt stroke,rather than radiologically obvious diffusion-weighted imaging ischaemic lesions.We aimed to quantify silent ischaemic lesions and haemorrhages on mRI at 1month in patients commenced on early(mic lesions and more haemorrhages in the early anticoagulant group at 1-month mRI.methods A prospective multicentre,observational cohort study was performed at 11 Australian stroke centres.Clinical and mRI data were collected at baseline and follow-up,with blinded imaging assessment performed by two authors.Timing of commencement of anticoagulation was at the discretion of the treating stroke physician.Results We recruited 276 patients of whom 208 met the eligibility criteria.The average age was 74.2 years(SD±10.63),and 79(38%)patients were female.median National Institute of Health Stroke Scale score was 5(IQR 1–12).median baseline ischaemic lesion volume was 5mL(IQR 2–17).There were a greater number of new ischaemic lesions on follow-up mRI in patients commenced on anticoagulation≥4days after index event(17%vs 8%,p=0.04),but no difference in haemorrhage rates(22%vs 32%,p=0.10).Baseline ischaemic lesion volume of≤5mL was less likely to have a new haemorrhage at 1month(p=0.02).There was no difference in haemorrhage rates in patients with an initial ischaemic lesion volume of>5mL,regardless of anticoagulation timing.Conclusion Commencing anticoagulationmic lesions at 1month in AF patients.There is no increased rate of haemorrhage with early anticoagulation.These results suggest that early anticoagulation after mild-to-moderate acute ischaemic stroke associated with AF might be safe,but randomised controlled s

关键词： patients lesions ischaemic

Antimony, Arsenic and Thallium Bioaccumulation in Asiatic Clam (Corbicula fluminea) Transplanted along the manadas Creek, Laredo, Texas

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Journal of Environmental Protection 2024年第4期15卷 379-400页

作者： Natasha garcia Vaughan Thomas Alfred Addo-mensah Department of Biology & Chemistry Texas A&M International University Laredo USA

manadas Creek is an urban tributary of the Rio Grande that flows past a decommissioned antimony smelter and processing plant. This antimony plant is associated with heavy metal contamination in the creek and still poses a threat to the surrounding aquatic environment. Corbicula fluminea was used to determine bioaccumulation from the water column and sediments in manadas Creek. The metals arsenic (As), antimony (Sb) and thallium (Tl) were analyzed in the water, sediments, gills, mantle, foot, digestive (DI) tract, gonads and shell of clams being monitored at eight sites between march and August 2013. Sediment, water, and dissected Corbicula fluminea samples from different sites in the Creek were acid-digested and analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy. High levels of antimony (25.88 ug/L;75.96 mg/kg) and arsenic (8.26 ug/L;6.41 mg/kg) in the water and sediments were observed at the site downstream from the smelter. There were no detectable concentrations of arsenic, antimony, or thallium in the shell of C. fluminea. Arsenic and antimony were detected in the tissues of C. fluminea but thallium was not detected. Based on the results, the organotropism for arsenic is DI tract > gills > gonads > foot > mantle > shell and the organotropism for antimony is gills > DI tract > gonads > mantle > foot > shell. This study shows that the Asiatic clam (Corbicula fluminea) is a useful bio-monitor to provide data on the status of metal pollution in manadas Creek, Laredo, Texas.

关键词： Biomarker manadas Creek Rio Grande Heavy metals Corbicula fluminea Biota Sediment Accumulation

Synthesis of coral-like structures of Pr-Yb co-doped YIG: Structural,optical, magnetic and antimicrobial properties

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Journal of Rare Earths 2024年第3期42卷 543-554,I0004页

作者： A.Fernandez Francisca P.Araujo Y.Guerra S.Castro-Lopes J.matilla-Arias Idglan S.de Lima Edson C.Silva-Filho Josy A.Osajima F.Guerrero R.Pena-garcia Federal University of Piau Graduate Program in Materials Science and EngineeringTeresinaPIBrazil Federal Rural University of Pernambuco Academic Unit of Cabo de Santo AgostinhoCabo de Santo AgostinhoPEBrazil Federal University of Piaui Department of PhysicTeresinaPBrazil Federal University of Pernambuco Graduate Program in Materials ScienceRecifePEBrazil University of Granma Departmentof Basic Sciences and Applied InformaticsFaculty of Technical SciencesBayamoCuba Federal University of Amazonas Department of PhysicManausAMBrazil Federal University of Pernambuco Department of PhysicRecifePEBrazil

Coral-like structures of the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12),(0.00 ≤ x ≤ 0.04, 0.00 ≤ y ≤ 0.02) compound were synthesized using the sol-gel method. Structural investigation certified the YIG cubic crystal structure formation, without any secondary phase. It is shown that, the relatively large ionic radius of the dopant cations results in an expansion of the lattice parameter, variations in the Iona-O-Iondangle, Iona-O,Iond-O and Ionc-O bond distances and decrease in the average crystallite size. Fourier transform infrared(FTIR) and Raman measurements are essential to testify the single-phase formation of YIG crystal structure and are observed changes in the stretching and vibrational modes, respectively. The morphological study, energy dispersive spectroscopy(EDS) spectra and textural properties show corallike structures, peaks associated with Pr^(3+) and Yb^(3+) atoms and the effect of dopants on surface area,diameter, and pore volume, respectively. The optical analysis from diffuse reflectance spectra witnessed an increase in the optical gap band, a decrease in Urbach energy and blue shift in the charge transfer,correlated with the expansion of the unit cell due to the dopant's insertion in the YIG structure. A typical ferrimagnetic behavior is exhibited by the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12)compound. The saturation magnetization(m_(s)), cubic anisotropy constant(K_(1)) and coercive field(H_(c)) increase with the Pr^(3+)cations content, as consequence of their magnetic nature and distribution around of Fe^(3+)ions due to the coexistence with the Yb^(3+). Finally, for the first time, antibacterial tests by mean of the direct contact method were performed for YIG co-doped with Pr^(3+)and Yb^(3+)and it is shown that, relatively high dosages of Pr^(3+) cations favored the activity against S. aureus, therefore, a new biological property for YIG doped with rare earths is presented.

关键词： Yttrium iron garnet(YIG) Coral-like structures Rare earths Band gap energy magnetic properties Antimicrobial properties

Strong emissions of blue-yellow-red regions of La and Ti modified KNaNbO_(3) ferroelectric ceramics

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Journal of Advanced Ceramics 2015年第3期4卷 183-189页

作者： m.D.DURRUTHY-RODRIGUEZ m.HERNANDEZ-garcia J.PORTELLES J.FUENTES m.A.HERNANDEZ-LANDAVERDE m.ramirez CARDONA J.m.YANEZ-LImON Departamento de Fisica Aplicada Instituto de CiberneticaMatematica y FisicaCITMA15#551VedadoLa HabanaCP 10400Cuba Facultad de Fisica Universidad de La HabanaSan Lazaro y LVedadoLa HabanaCP 10400Cuba CINVESTAV-Unidad Queretaro IPNLibramiento Norponiente 2000Fracc.Real de JuriquillaCP 76230QueretaroMexico Centro de Investigaciones en Ciencias de la Tierra y materiales Universidad Autonoma del Estado de HidalgoMexico

In this work,the results of the study on the optical properties of the perovskite structure ABO3 with La^(3+) substitution for ions K^(+) and Na^(+) in the A site and Ti^(4+) substitution for ion Nb^(5+) in the B site are presented.The ceramics were sintered at 1100℃ and 1190℃ and formed at 10 mPa and 80 mPa.Dense ceramics were obtained with 94% of the theoretical density.The piezoresponse force microscopy(PFm)showed needle-shaped grains with a size of 30 nm for the samples formed at 10 mPa at both sintering temperatures.Apparently,the high temperature and high pressure used in formation reduced the energy of the band gap(Eg)from 3.36 to 3.09 eV.Strong emissions to 2.19,1.86,2.5,and 2.31 eV were obtained by exciting the samples at 325,373,457,and 500 nm,respectively;these emissions corresponded to blue-yellow-red regions of the visible spectrum.

关键词： emission spectra condense matter ferroelectric materials band structure X-ray diffraction(XRD)

Distribution and Relation of Primes with Tesla Numbers 3, 6, and 9

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Journal of Applied mathematics and Physics 2024年第4期12卷 1021-1027页

作者： Javier mendoza-Navarrete Huetzin Perez Ismael Ojeda Victor Verdugo Gabriel Luna Sandoval Ricardo Jimenez garcia Jaime Alvarez Departametno de matemá ticas CBTis 256 DGETI Cabo San Lucas M&#233xico DCI Departamento de Fisica mé dica Universidad de Guanajuato Leon M&#233xico Divisió n de Ingenieria en Sistemas Computacionales Tecnol&#243gico Nacional de M&#233xico ITES Los Cabos Cabo San Lucas M&#233xico Departamento de Ingenieria Industrial en manufactura Universidad Estatal de Sonora Navojoa M&#233xico Departamento de Elé ctrica-Electr&#243nica Tecnol&#243gico Nacional de M&#233xico Campus Mexicali Mexicali M&#233xico Guanajuato M&#233xico

This work presents a different approach to twin primes, an approach from the perspective of the Tesla numbers and gives a refresh and new observation of twin primes that could lead us to an answer to the Twin Prime Conjecture problem. We expose a peculiar relation between twin primes and the generation of prime numbers with Tesla numbers. Tesla numbers seem to be present in so many domains like time, vibration and frequency [1], and the space between twin primes is not the exception. Let us say that twin primes are more than just prime numbers plus 2 or minus 2, and Tesla numbers are more involved with twin primes than we think, and hopefully, this approach give us a better understanding of the distribution of the twin pairs.

关键词： Tesla Numbers Prime Number Twin Prime Numbers Twin Pair

The Nikola Tesla Constant and Its Relation to the Circumference Inscribed in a Square

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Journal of Applied mathematics and Physics 2024年第1期12卷 277-283页

作者： Javier mendoza Navarrete José Ismael Ojeda Campaña Huetzin Perez Gabriel Luna-Sandoval Victor Verdugo Ricardo Jiménez garcia Departamento de matemáticas CBTis 256 DGETI Cabo San Lucas México División de Ingeniería en Sistemas Computacionales Tecnológico Nacional de México/ITES de Los Cabos Cabo San Lucas México DCI Departamento de Física médica Universidad de Guanajuato León México Departamento de Ingeniería Industrial en manufactura Universidad Estatal de Sonora Navojoa México Departamento de Eléctrica-Electrónica Tecnológico Nacional de México Campus Mexicali Mexicali México

This research work relates the surface of a square and the area circumscribed by a circle, resulting in a value called Nikola Tesla constant. This constant starts with the calculation of the areas of the square and the inscribed circle, giving a ratio of 9/40 and from which a residual area of the area proportions of the geometric figures described is obtained. Plotting smooth curves, particularly those in round shapes, can be represented efficiently with the use of Nikola Tesla constant, reducing complex mathematical calculus.

关键词： Tesla Numbers Prime Number Circle Binary Area

Beneficial effects of saffron(Crocus sativus L.) in ocular pathologies, particularly neurodegenerative retinal diseases

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Neural Regeneration Research 2020年第8期15卷 1408-1416页

作者： Jose A.Fernandez-Albarral Rosa de Hoz Ana I.ramirez Ines Lopez-Cuenca Elena Salobrar-garcia maria D.Pinazo-Duran Jose m.ramirez Juan J.Salazar Instituto de Investigaciones Oftalmologicas Ramon Castroviejo MadridSpain Departamento de Inmunologia Oftalmologia y ORLFacultad de Optica y OptometriaMadridSpain Departamento de Inmunologia Oftalmologia y ORLFacultad de MedicinaMadridSpain Unidad de Investigacion Oftalmologica Santiago Grisolia Universidad de ValenciaValenciaSpain

Saffron(Crocus sativus L.)has been traditionally used in food preparation and as a medicinal plant.It currently has numerous therapeutic properties attributed to it,such as protection against ischemia,as well as anticonvulsant,antidepressant,anxiolytic,hypolipidemic,anti-atherogenic,anti-hypertensive,antidiabetic,and anti-cancer properties.In addition,saffron has remarkable beneficial properties,such as anti-apoptotic,anti-inflammatory and antioxidant activities,due to its main metabolites,among which crocin and crocetin stand out.Furthermore,increasing evidence underwrites the possible neuroprotective role of the main bioactive saffron constituents in neurodegenerative diseases,such as Parkinson’s and Alzheimer’s diseases,both in experimental models and in clinical studies in patients.Currently,saffron supplementation is being tested for ocular neurodegenerative pathologies,such as diabetic retinopathy,retinitis pigmentosa,age-related macular degeneration and glaucoma,among others,and shows beneficial effects.The present article provides a comprehensive and up to date report of the investigations on the beneficial effects of saffron extracts on the main neurodegenerative ocular pathologies and other ocular diseases.This review showed that saffron extracts could be considered promising therapeutic agents to help in the treatment of ocular neurodegenerative diseases.

关键词： AmD crocetin crocin Crocus sativus L. diabetic retinopathy glaucoma neuroprotection ocular diseases retinitis pigmentosa saffron safranal

Unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neuropathology and behavioral deficits in parkinsonian rats withα-synucleinopathy

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Neural Regeneration Research 2024年第9期19卷 2057-2067页

作者： Bismark Gatica-garcia michael J.Bannon Irma Alicia martínez-Dávila Luis O.Soto-Rojas David Reyes-Corona Lourdes Escobedo minerva maldonado-Berny mE Gutierrez-Castillo Armando J.Espadas-Alvarez manuel A.Fernandez-Parrilla Juan U.mascotte-Cruz CP Rodríguez-Oviedo Irais E.Valenzuela-Arzeta Claudia Luna-Herrera Francisco E.Lopez-Salas Jaime Santoyo-Salazar Daniel martinez-Fong Departamento de Fisiología Biofísica y NeurocienciasCentro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico Department of Pharmacology Wayne State University School of MedicineDetroitMIUSA Laboratorio de Patogénesis molecular Carrera Médico CirujanoFacultad de Estudios Superiores IztacalaUniversidad Nacional Autónoma de MéxicoTlalnepantla de BazMéxico Red de medicina para la Educación y Desarrollo y la Investigación Científica de Iztacala(Red mEDICI) Carrera Médico CirujanoFacultad de Estudios Superiores IztacalaUniversidad Nacional Autónoma de MéxicoTlalnepantla de BazMéxico Nanoparticle Therapy Institute AguascalientesMéxico Departamento de Biociencias e Ingeniería Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y DesarrolloInstituto Politécnico NacionalCiudad de MéxicoMéxico Escuela Nacional de medicina y Homeopatía Instituto Politécnico NacionalCiudad de MéxicoMéxico Departamento de Fisiología Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCiudad de MéxicoMéxico Departamento de Biología molecular y Biotecnología Instituto de Investigaciones BiomédicasUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMéxico Departamento de Física Centro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico Programa de Nanociencias y Nanotecnología Centro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico

Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-synucleinopathy.As Nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rNurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 post-transfection.This study found that rNurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced neuropathology.Accordingly,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the striatum.In addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia nigra.These effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor behavior.Our results show that unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor deficits.Increased neurotrophic astrocytes and brain-derived neurotrophic factor can mediate t

关键词： A1 astrocytes A2 astrocytes gene therapy microglia motor deficits nanoparticles neurodegeneration neuroinflammation senescence α-synuclein aggregates