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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

Isolation, characterization and effect of plant-growth-promoting rhizobacteria on pine seedlings(Pinus pseudostrobus Lindl.)

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Journal of Forestry Research 2019年第5期30卷 1727-1734页

作者： Cristina Heredia-Acuna Juan J.Almaraz-Suarez Ramon Arteaga-Garibay Ronald Ferrera-Cerrato deisy Y.Pineda-Mendoza Area de microbiologia Postgrado de EdafologiaColegio de PostgraduadosCarretera Mexico-Texcoco km 36.5CP 56230 MontecilloEstado de MexicoMexico laboratorio de Recursos Geneticos Microbianos Centro Nacional de Recursos GeneticosINIFAPBoulevard de la Biodiversidad No.400CP 47600 Tepatitlan de MorelosJaliscoMexico

In this study,10 bacterial strains were isolated from the rhizosphere of coniferous trees on Mount Tla′loc in *** strains were characterized by their capacity to produce auxins,solubilize phosphates and stimulate mycelial growth of the ectomycorrhizal fungus Suillus *** isolates were identified at the molecular ***,an experiment was established to evaluate the response of Pinus pseudostrobus seedlings to inoculation with the rhizobacteria *** isolated strains belonged to the species Cupriavidus basilensis,Rhodococcus qingshengii,***,Pseudomonas spp.,***,Stenotrophomonas rhizophila and Cohnella *** of the strains produced auxins;the best producer was *** CPT9(76.4 lg mL^-1).*** CPT6 solubilized phosphate at a significant level(443 lg mL^-1).The strain *** CPT8 significantly increased the radial growth of the ectomycorrhizal fungus Suillus *** 18.8%.Five strains increased the dry mass of the shoots;*** CPT4 and *** CPT9 increased growth the most,by more than 20%.Inoculation with plant-growth-promoting rhizobacteria can be a very useful practice in a forest nursery to produce healthy,vigorous plants.

关键词： Biofertilizers Forest species Rhizobacteria Indole acetic acid Phosphate solubilization

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

Antibacterial enhancement of antibiotic activity by Enterolobium contortisiliquum(Vell.)Morong

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Asian Pacific Journal of Tropical Biomedicine 2017年第10期7卷 945-949页

作者： Zildene de Sousa Silveira Nair Silva Macêdo Thiago Sampaio de Freitas Ana Raquel Pereira da Silva Joycy Francely Sampaio dos Santos Maria Flaviana Bezerra Morais-Braga José Galberto Martins da Costa Raimundo Nonato Pereira Teixeira Jean Paul Kamdem Henrique Douglas Melo Coutinho Francisco Assis Bezerra da Cunha laboratorio de Bioprospeccao do Semioarido Universidade Regional do CaririCratoBrazil laboratorio de microbiologia e Biologia Molecular Universidade Regional do CaririCratoBrazil laboratorio de Pesquisas de Produtos Naturais Universidade Regional do CaririCratoBrazil departamento de Ciencias biologicas Universidade Regional do Cariri-URCACratoCEP:63105-000Brazil Programa de Pos-graduacao em Bioprospeccao Molecular Universidade Regional do Cariri–URCACratoBrazil

Objective: To identify the main chemical classes of compounds from aqueous extract of Enterolobium contortisiliquum(E. contortisiliquum) seed bark and to evaluate its antibacterial activity, as well as its potential to increase the activity of antibiotics against strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia ***: Different classes of compounds in the aqueous extract of E. contortisiliquum were evaluated based on the visual changes in the coloration and the formation of precipitate after the addition of specific reagents. The antibacterial activity of the extract and its potential to increase of antibiotic activity of antibiotics drugs, gentamicin and norfloxacin was determined by using the microdilution ***: Our results demonstrated that the following secondary metabolites were presented in E. contortisiliquum seed bark: flavones, flavonols, xanthones, flavononols,chalcones, aurones, flavones and catechins. The extract itself had very low antibacterial activity against all bacterial strains tested(MIC ≥ 1024 μg/m L), but there was an increase in the antibiotic activity of gentamicin and norfloxacin when combined in the subinhibitory concentration(i.e., MIC/8).Conclusions: Our data suggests that E. contortisiliquum seed bark may be an alternative source for new drugs with the potential to increase antibiotic activity against different strains of bacteria.

关键词： Antibiotic activity Enhancement Synergism Chemical compounds Bioactivity

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; P<0.001). Furthermore,arthritis(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

The Control of Lactobacillus *** Extracellular Compound Produced by Pseudomonas aeruginosa in the Fermentation Process of Fuel Ethanol Industry in Brazil

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Journal of Sustainable Bioenergy Systems 2013年第3期3卷 194-201页

作者： Cintia Greice Matsuoca Gois Lucilene Lopes-Santos Jamile Priscila de Oliveira Beranger Admilton Goncalves de Oliveira Flavia Regina Spago Galdino Andrade departamento de microbiologia Laboratorio de Ecologia MicrobianaUniversidade Estadual de LondrinaLondrinaBrazil

This work evaluated the effect of secondary bacterial metabolites produced by Pseudomonas sp LV strain in control of Lactobacillus sp. population in the microcosm of the vat during ethanol fermentation. The fraction F4 produced by Pseudomonas aeruginosa was extracted with dichloromethane and fractionating by vacuum liquid chromatography obtained in a methanol phase. The evaluation of antibiotic activity of F4 fraction mixed or not with sulphuric acid and Kamoram?. The antibiotic activity of F4 fraction was determined as well as the fermentation efficiency. Also was determined yeast cell viability, budding formation, the viability of budding cells, and number of populations of Saccharomyces cerevisiae and Lactobacillus sp. The results showed that the F4 fraction had high selective antibiotic activity against Lactobacillus sp. but not for S. cerevisae, and no inhibitory effect was observed in the fermentation process by yeast. Also F4 fraction decreased flocculation and foam formation. The F4 has an antibiotic activity against Lactobacillus sp. and should be used as an alternative to control bacteria contamination and foam and flocculation formation in the fuel ethanol fermentation process. The F4 fraction could reduce the use of antibiotics in the control of Lactobacillus sp. population during the fuel ethanol production.

关键词： Fuel Ethanol Fermentation Contamination Lactobacillus Yeast Pseudomonas

Brazilian vaccinia virus strains show a classical orthopoxvirus infection course and cross-protection

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Asian Pacific Journal of Tropical Medicine 2009年第2期2卷 21-26页

作者： Jaqueline Maria Siqueira Ferreira Betnia Paiva Drumond J?natas Santos Abraho Zélia Inês Portela Lobato Cláudio Ant?nio Bonjardim Paulo César Peregrino Ferreira Erna Geessien Kroon laboratorio de Virus Departamento de MicrobiologiaInstituto de Ciencias Biologicas departamento de Medicina Veterinaria Preventiva Escola de VeterindriaUniversidade Federal de Minas Gerais.Avenida Antonio Carlos6627caixa postal 486CEP 31270-901 Belo HorizonteMGBrazil

Objectives:The purpose of this work was to study the infection course and cross-protection in mice after intradermal injection of Vaccinia virus(VACV) strain Western Reserve and three Brazilian VACV strains: Aracatuba,Muriae and BeAn58058 isolated from cow,human and rodent,***:Balb/c mice were inoculated by footpad and back scarification and daily monitored regarding lesion development and weight *** check cross protection after intradermal VACV inoculation,mice were subsequendy infected with different VACV strains and monitored to check lesion *** neutralization assays were performed to check for the presence of antibodies against ***:After VACV intradermal inoculation the lesion development pattern was similar in mice infected with the different virus *** using the footpad scarification model,cross-protection among VACV strains was ***,neutralizing antibodies against Orthopoxvirus were detected in sera from mice infected with all VACV ***:Although it was not possible to observe virulence differences among VACV strains isolated from cow,rodent and human using the murine model,this inoculation route showed to be an appropriated model to study lesions development since it mimics natural infections by VACV in nature.

关键词： Orthopoxvirus Zoonoses Balb/c mice Intradermal injection Vaccinia virus Bovine vaccinia outbreaks