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Influence of dissolved organic matter character on mercury incorporation by planktonic organisms: An experimental study using oligotrophic water from Patagonian lakes

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Journal of Environmental sciences 2013年第10期25卷 1980-1991页

作者： María C.Diéguez Claudia P.Queimalios sergio Ribeiro Guevara Mark Marvin-DiPasquale Carolina soto Crdenas María A.Arribre laboratorio de Fotobiología INIBIOMA CONICET-UNComahue laboratorio de Fotobiolog INIBIOMA CONICET-UNComahue laboratorio de Anlisis por Activación Neutrónica Centro Atómico Bariloche CNEA United states Geological survey laboratorio de Anlisis por Activacio Neutrónica Centro Atómico Bariloche CNEA

Ligands present in dissolved organic matter （DOM） form complexes with inorganic divalent mercury （Hg^2＋） affecting its bioavailability in pelagic food webs. This investigation addresses the influence of a natural gradient of DOM present in Patagonian lakes on the bioaccumulation of Hg^2＋（the prevailing mercury species in the water column of these lakes） by the algae Cryptomonas erosa and the zooplankters Brachionus calyciflorus and Boeckella antiqua. Hg^2＋ accumulation was studied through laboratory experiments using natural water of four oligotrophic Patagonian lakes amended with^197Hg^2＋. The bioavailability of Hg^2＋ was affected by the concentration and character of DOM. The entrance of Hg^2＋ into pelagic food webs occurs mostly through passive and active accumulation. The incorporation of Hg^2＋ by Cryptomonas, up to 27% of the Hg^2＋ amended, was found to be rapid and dominated by passive adsorption, and was greatest when low molecular weight compounds with protein-like or small phenolic signatures prevailed in the DOM. Conversely, high molecular weight compounds with a humic or fulvic signature kept Hg^2＋ in the dissolved phase, resulting in the lowest Hg^2＋ accumulation in this algae. In Brachionus and Boeckella the direct incorporation of Hg from the aqueous phase was up to 3% of the Hg^2＋ amended. The dietary incorporation of Hg^2＋ by Boeckella exceeded the direct absorption of this metal in natural water, and was remarkably similar to the Hg^2＋ adsorbed in their prey. Overall, DOM concentration and character affected the adsorption of Hg^2＋ by algae through competitive binding, while the incorporation of Hg^2＋ into the zooplankton was dominated by trophic or dietary transfer.

关键词： mercury dissolved organic matter plankton mercury incorporation Patagonian lakes Argentina

Nucleation and growth kinetics of La0.7sr0.3Cr0.4Mn0.6O3-δ sOFC perovskite:symmetry alteration evolution induced by Cu2+ and Ni2+ impregnation

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Progress in Natural science:Materials International 2016年第6期26卷 665-670页

作者： A.Concha-Balderrama G.Rojas-George J.Alvarado-Flores H.Esparza-Ponce M.H.Bocanegra-Bernal A.Reyes-Rojas Centro de Investigación en Materiales Avanzados s.C.(CIMAV) Laboratorio Nacional de NanotecnologíaMiguel de Cervantes 120 Complejo Industrial ChihuahuaCd.de Chihuahua

La0.7sr0.3Cr0.4Mn0.6O3-δperovskite nanoparticles have been synthetized using an ethylene glycol modified solgel method and impregnated by Cu0.75Ni0.25nanoparticles. The phase transitions and nucleation kinetics were studied by time resolved x-ray diffraction, Rietveld, Raman spectroscopy and high resolution transmission electron microscopy. Findings have shown that, an atomic disorder dominates from room temperature to 400 °C. Nanoparticles with crystal size start through nuclei formation of La0.7sr0.3Cr0.4Mn0.6O3-δand srCrO4solid solutions with Pm3m cubic and P21/n monoclinic symmetry respectively in the range of 600–650 °C. symmetry reduction from the Pm3m→R3c space group had been obtained at a lower temperature（750 °C） than those reported in the literature in oxygen atmosphere and it was confirmed by an octahedral distortion, which takes place in the crystallographic direction[221]/（122）. The Johnson-Mehl-Avrami model had described the whole process, where the existence of two phases was shown before it reached its complete D3d6point group symmetry.

关键词： Perovskite structure sol-gel method Composite Kinetics Rietveld

Apomorphine effects on the hippocampus

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Neural Regeneration Research 2018年第12期13卷 2064-2066页

作者： Luis Enrique Arroyo-García Antonio Rodríguez-Moreno Gonzalo Flores laboratorio de Neuropsiquiatria Instituto de Fisiologia Benemerita Universidad Autenoma de Puebla Puebla Mexico laboratorio de Neurociencia Celular y Plasticidad Universidad Pablo de Olavide Sevilla Spain

Apomorphine is a non-specific dopamine receptor agonist that has been used in the treatment of some diseases and mental disorders. Its use has particularly well documented in Parkinson＇s disease（PD）. The dopaminergic agonists like apomorphine are related to oxidative processes that could induce cell damage and the functional impairment of some structures in the brain. However, most information about apomorphine in literature is focused on the improvement of the motor problems characteristic of PD, but little is known about the effects on cognitive behaviors and brain structures indirectly related to motor function. The presence of dopaminergic receptors in the hippocampus has recently been discovered, in connection with cognitive behaviors like learning and memory, these receptors are needed in neuronal plasticity. There has been a growing interest to know if this structure could be compromised by the effect of apomorphine and elucidate if part of the cognitive impairment present in the PD is due to the effect of apomorphine. In this mini-review, we summarized how apomorphine has been used since its creation, we discuss the latest information about its effect on the hippocampus and also the future perspectives to fully understand the effects of this compound.

关键词： dopamine receptor apomorphine hippocampus learning and memory plasticity dendritic length oxidative stress Parkinson's disease

sARs-CoV-2 infection in liver transplant recipients:A complex relationship

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World Journal of Gastroenterology 2021年第44期27卷 7734-7738页

作者： Ricardo Wesley Alberca Gil Benard Gabriela Gama Freire Alberca Maria Notomi sato laboratorio de dermatologia e Imunodeficiencias(LIM-56) Departamento de Dermatologia e Institute de Medicina TropicalFaculdade de Medicina FMUSPUniversidade de São PauloSão Paulo 01246-903Brazil laboratorio de dermatologia e Imunodeficiencias(LIM-56) Departamento de DermatologiaFaculdade de Medicina FMUSPUniversidade de São PauloSão Paulo 01246-903Brazil

The recent manuscript reviewed investigations involving liver damage in coronavirus disease 2019(COVID-19)patients,and COVID-19 in patients with previous chronic hepatological diseases,such as patients with liver *** literature presents several conflicting results concerning the anti-sARs-CoV-2 response in patients with solid organ transplants,in liver transplant ***,we would like to humbly state a few points for consideration involving liver transplant recipients and COVID-19,such as the time since transplantation,comorbidities,and immunosuppressive regimens.

关键词： COVID-19 sARs-CoV-2 Liver transplant Immunosuppression Infection Comorbidities

Curcuma longa L. extract improves the cortical neural connectivity during the aging process

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Neural Regeneration Research 2017年第6期12卷 875-880页

作者： Gonzalo Flores laboratorio de Neuropsiquiatría Instituto de Fisiología Benemérita Universidad Autónoma de Puebla

Turmeric or Curcuma is a natural product that has anti-inflammatory, antioxidant and anti-apoptotic pharmacological properties. It can be used in the control of the aging process that involves oxidative stress, inflammation, and apoptosis. Aging is a physiological process that affects higher cortical and cognitive functions with a reduction in learning and memory, limited judgment and deficits in emotional control and social behavior. Moreover, aging is a major risk factor for the appearance of several disorders such as cerebrovascular disease, diabetes mellitus, and hypertension. At the brain level, the aging process alters the synaptic intercommunication by a reduction in the dendritic arbor as well as the number of the dendritic spine in the pyramidal neurons of the prefrontal cortex, hippocampus and basolateral amygdala, consequently reducing the size of these regions. The present review discusses the synaptic changes caused by the aging process and the neuroprotective role the Curcuma has through its anti-inflammatory, antioxidant and anti-apoptotic actions.

关键词： Curcuma longa cortical curcumin hippocampus synaptic antioxidant spine connectivity cortex

X-linked Toll-like receptor 7 polymorphism associated with susceptibility to Chikungunya Fever

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Asian Pacific Journal of Tropical Medicine 2019年第3期12卷 137-141页

作者： Daniela M.Rauseo Mercedes Fernández-Mestre laboratorio de Fisiopatología Centro de Medicina ExperimentalIVIC

Objective: To investigate the association between TLR3 and TLR7 polymorphisms with susceptibility and clinical manifestations of Chikungunya ***: A total of 177 individuals were studied: 73 patients with a confirmed diagnosis for Chikungunya virus and 104 non-infected individuals. Polymorphisms were determined by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism(PCR-RFLP).Results: Our analysis showed an increased CC genotype frequency of the TLR7 rs3853839 polymorphism in male patients compared to control(29% versus 2%,respectively; OR=20.69; 95% CI=2.55-167.36; Ps(acute and chronic) was frequently found in CC male patients. On the contrary,65% of CG carriers were no-infected males(29% versus 65%,respectively; OR=0.23,95% CI=0.48-3.04; P=0.002). Finally,we observed a higher frequency of lymphopenia in CG male patients(CG=666.86±233.77,GG=1,314.27±752.29 cells/mm3,P=0.047). Conclusions: Our results suggest the TLR7 rs3853839 polymorphism is associated with lymphopenia and increased susceptibility to Chikungunya Fever in males.

关键词： Chikungunya Fever Toll-like-receptors single-nucleotide polymorphisms Disease susceptibility

sex-dependent resilience to extreme drought events: implications for climate change adaptation of a south American endangered tree species

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Ecological Processes 2024年第2期13卷 48-60页

作者： sergio Piraino Martín Ariel Hadad Yanina Antonia Ribas-Fernández Fidel Alejandro Roig laboratorio de dendrocronología e Historia Ambiental (IANIGLA CONICET ) Facultad de Ciencias Agrarias Universidad Nacional de Cuyo laboratorio de dendrocronología de Zonas áridas (CIGEOBIO CONICET ) Gabinete de Geología Ambiental (INGEO UNSJ) Hémera Centro de Observación de la Tierra Facultad de Ciencias Universidad Mayor

Background Recent changes in climatic trends are resulting in an increased frequency and intensity of extreme events, with unknown effect on ecosystem dynamics in the near future. Extreme drought episodes are recognized as disturbance factors capable of modifying forest dynamics and tree growth. Within this context, dioecious tree species may be impacted by climatic extremes, affecting male/female proportions and, consequently, reproductive processes and species persistence. Therefore, there is an urgent need for species-specific assessments of growth tolerance to extreme dry spells in dioecious tree species, to establish effective conservation strategies for these particular natural resources. Araucaria araucana(araucaria), an endangered dioecious Patagonian tree species, has recently undergone decay and mortality episodes in response to increasing dry climatic conditions. While sex-dependent tolerance to extreme drought episodes has been assessed in the species' humid distribution range, there is still a lack of information on the gender-based resilience of trees growing in the drier environments of the species' *** We reconstructed, through dendrochronological methods, the sex-dependent response of 105 araucaria individuals(55 female and 50 male trees) to five regional extreme dry spells employing a set of different indices. Resistance, recovery period, and average growth reduction of standardized tree-ring growth were examined, analysing the effect of biotic(sex, pre-drought stem tree growth) and abiotic(local climatic conditions before, during, and after extreme climatic episodes) factors on tree *** sex influences only the species resistance to climatic disturbance, with male individuals showing lower tolerance to extreme drought events. Pre-drought radial growth rates and local meteorological conditions preceding, during, and following extreme dry spells strongly modulated araucaria radial growth resilience regardless of tree s

关键词： Araucaria Climate change dendrochronology Extreme drought event Resilience

Experimental study on lightweight expanded clay at particle level:Breakage of isolated grains

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第7期15卷 1846-1858页

作者： Elías Roces-Alonso Jose Estaire Miriam Martín-Ruiz Jesús González-Galindo ETs de Ingenieros de Caminos Universidad Politécnica de MadridSpain laboratorio de Geotecnia CEDEXMadridSpain

In this study,more than 1500 particles of lightweight expanded clay aggregate(LECA)are individually loaded up to breakage,following different patterns of contact(from 2 to 7)using a purpose-built ***,a statistical model for predicting the number of fragments into which a grain breaks as a function of the number of contacts and their diameter is *** number of fragments is found to follow a statistical binomial-type distribution function that depends on the number of *** addition,a model based on Bayesian networks,capable of assessing the number of fragments and their size(measured as normalized weight)as a function of the number of contacts,is *** proposed method is applicable when performing discrete element method(deM)simulations on granular media in which grain breakage plays a relevant role.

关键词： Lightweight expanded clay aggregate(LECA) Grain fragmentation Grain breakage Biaxial grain load

Orbit orientation in didelphid marsupials （Didelphimorphia： Didelphidae）

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Current Zoology 2017年第4期63卷 403-415页

作者： Patricia PILATTI Diego AsTUA laboratorio de Mastozoologia Departamento de Zoologia Universidade Federal de Pernambuco. Av. Prof. Moraes Rego S/N Cidade Universitaria Recife PE 50670-901 Brazil

Usually considered a morphologically conservative group, didelphid marsupials present consider- able variation in ecology and body size, some of which were shown to relate to morphological structures. Thus, changes on orbit morphology are likely and could be related to that variation. We calculated orbit orientation in 873 specimens of 16 Didelphidae genera yielding estimates of orbits convergence （their position relative to midsagittal line） and verticality （their position relative to frontal plane）. We then compared similarities in these variables across taxa to ecological, morpho- logical and phylogenetic data to evaluate the influencing factors on orbit orientation in didelphids. We found an inverse relation between convergence and verticality. Didelphids orbits have low ver- ticality but are highly convergent, yet orbit orientation differs significantly between taxa, and that variation is related to morphological aspects of the cranium. Rostral variables are the only morpho- logical features correlated with orbit orientation： increasing snout length yields more convergent orbits, whereas increase on snout breadth imply in more vertical orbits. size and encephalization quotients are uncorrelated with orbit orientation. Among ecological data, diet showed significant correlation whereas locomotion is the factor that less affects the position of orbits. Phylogeny is uncorrelated to any orbital parameters measured. Ecological factors seemingly play a more import- ant role on orbit orientation than previously expected, and differentiation on orbit orientation seems to be more functional than inherited. Thus, despite the apparent homogeneity on didelphid morphology, there is subtle morphological variability that may be directly related to feeding behavior.

关键词： convergence Didelphidae frontation orbit orientation verticality.