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Arsenic and chromium resistance mechanisms in the Micrococcus luteus group

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Pedosphere 2023年第4期33卷 600-611页

作者： Ivan ARROYO-HERRERA Brenda ROMÁN-PONCE Rafael BUSTAMANTE-BRITO Joseph GUEVARA-LUNA Erika Yanet TAPIA-GARCÍA Violeta LARIOS-SERRATO Nannan ZHANG paulina estrada-de los santos En Tao WANG María Soledad VÁSQUEZ-MURRIETA Escuela Nacional de Ciencias Biológicas Instituto Politécnico NacionalCiudad de México 11340(Mexico) Universidad Politécnica del Estado de Morelos Jiutepec 62550(Mexico) Centro de Ciencias Genómicas Universidad Autónoma de MéxicoCuernavaca 62210(Mexico) CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilisation&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province Chengdu Institute of BiologyChinese Academy of SciencesChengdu 610041(China)

High arsenic(As)and chromium(Cr)concentrations are currently receiving attention because of their negative effects on the environment and human *** inhabiting contaminated environments have developed resistance mechanisms against the toxicity of these ***,members of the bacterial genus Micrococcus have been isolated from different toxic metal-contaminated environments;however,knowledge concerning its resistance mechanisms to As and Cr toxicity remains *** luteus strains(An24,Mh,NE2TL6,and NE2TTS4)were isolated from the endosphere and soil of two heavy metal-contaminated sites in Mexico to identify differences in the resistance mechanisms by the *** *** strains were resistant to As(As^(3+)and As^(5+)),chromate,dichromate,cobalt,copper,nickel,and *** analysis indicated that the heavy metal-resistant strains(An24,Mh,NE2TL6,and NE2TTS4)could be assigned to the *** group and had more heavy metal-resistant genes(transporters,chaperones,and enzymes)compared to reference strains of the *** group,*** NCTC 2665^(T)and Micrococcus endophyticus JCM 16951^(T).The resistant bacteria were able to biotransform As^(3+)and As^(5+)through a carbon source-dependent *** biotransformation of As5+was potentially carried out in the cytoplasm through a thioredoxin-dependent pathway,which may be coupled with biosorption.A qualitative analysis of organic acids(OAs)identified a change in the OA profile of the metal-resistant strains that was As-or *** genomic and phenotypic findings suggest that the four *** group strains evaluated in the current study have developed resistance mechanisms that may enable their survival in contaminated sites.

关键词： arsenophore biosorption genome analysis heavy metal-resistant strain immobilization organic acid pollutant

Plant Growth-Promoting Traits in Rhizobacteria of Heavy Metal-Resistant Plants and Their Effects on Brassica nigra Seed Germination

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Pedosphere 2017年第3期27卷 511-526页

作者： Brenda ROMN-PONCE Diana Miryel REZA-VZQUEZ Sonia GUTIRREZ-PAREdeS María de Jesús de HARO-CRUZ Jessica MALDONADO-HERNNdeZ Yanely BAHENA-OSORIO paulina estrada-de los santos En Tao WANG María Soledad VSQUEZ-MURRIETA Instituto Politécnico Nacional Escuela Nacional de Ciencias Biológicas Prolongación Carpio y Plan de Ayala s/n Col.Santo Tomás Del.Miguel Hidalgo Ciudad de México

Phytoremediation is an emerging technology that uses plants and their associated microbes to clean up pollutants from the soil, water, and air. In order to select the plant growth-promoting rhizobacteria(PGPR) for phytoremediation of heavy metal contamination, 60 bacterial strains were isolated from the rhizosphere of two endemic plants, Prosopis laevigata and Spharealcea angustifolia, in a heavy metal-contaminated zone in Mexico. These rhizobacterial strains were characterized for the growth at different pH and salinity, extracellular enzyme production, solubilization of phosphate, heavy metal resistance, and plant growth-promoting(PGP) traits, including production of siderophores and indol-3-acetic acid(IAA). Overall, the obtained rhizobacteria presented multiple PGP traits. These rhizobacteria were also resistant to high levels of heavy metals(including As as a metalloid)(up to 480 mmol L(-1)As(V), 24 mmol L(-1)Pb(Ⅱ), 21 mmol L(-1)Cu(Ⅱ), and 4.5 mmol L(-1)Zn(Ⅱ)). Seven rhizobacterial strains with the best PGP traits were identified as members of Alcaligenes, Bacillus, Curtobacterium, and Microbacterium, and were selected for further *** inoculation of Brassica nigra seeds with Microbacterium sp. CE3R2, Microbacterium sp. NE1R5, Curtobacterium sp. NM1R1,and Microbacterium sp. NM3E9 facilitated the root development; they significantly improved the B. nigra seed germination and root growth in the presence of heavy metals such as 2.2 mmol L(-1)Zn(Ⅱ). The rhizobacterial strains isolated in the present study had the potential to be used as efficient bioinoculants in phytorremediation of soils contaminated with multiple heavy metals.

关键词：重金属污染土壤植物根际土壤植物生长种子萌发抗性植物植物修复技术 PGPR 甘蓝

Heavy Metals in Agricultural Soils of Constanza, Jarabacoa, San José de Ocoa, Azua, Barahona and San Juan de la Maguana, Dominican Republic, 2022

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Journal of Geoscience and Environment Protection 2024年第1期12卷 64-79页

作者： Ramón delanoy Carime Matos-Espinosa Yamilesa Herrera de los santos Institute of Physics Autonomous University of Santo Domingo Santo Domingo Dominican Republic Ministry of Higher Education Science and Technology Santo Domingo Dominican Republic

The objective of this study was to establish a baseline for future studies that aim to determine possible contamination from human, agricultural and industrial activities. As well as the determination of the indices of environmental or geological contamination and enrichment factors of heavy metals Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in agricultural soils of Constanza, Jarabacoa, Rancho Arriba and San José de Ocoa (SJO), municipalities located in the valleys of the Central mountain range of the Dominican Republic. The determination of the concentrations of heavy metals was carried out using the X-ray Fluorescence technique. Just like in Azua, San Juan de la Maguana (SJM) y Barahona in the southwest. Producer municipalities of vegetables, rice, beans, corn, melon, watermelon, tomato, banana, avocado, sugar cane and fodder for cattle. The concentration of 160 mg·kg-1 Probable Effect Level (PEL) of Cr according to the SQuiRTs table (USEPA-NOAA) for agricultural soils, were exceeded in 50% of the samples in SJM, SJO, Jarabacoa and Constanza;in Barahona and Azua by 20%. The PEL of 42.8 mg·kg-1 of the Ni was higher in more than 50% of the samples from SJM, Azua, Barahona and Jarabacoa;in SJO and Constanza at 35%. In the case of Cu with a PEL of 108 mg·kg-1 in SJO and Constanza, 5% of the samples exceeded its, in the other areas the concentrations were lower. Zn, As and Pb did not manage to exceed their respective PEL.

关键词： Soil Heavy Metals Constanza Azua X-Ray Fluorescence

Are we ready to use new endoscopic scores for ulcerative colitis?

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World Journal of Gastroenterology 2024年第10期30卷 1466-1469页

作者： Rodrigo Quera paulina Núñez F Universidad de los Andes Inflammatory Bowel Disease ProgramClinica Universidad de los AndesDigestive Disease CenterSantiago 7600976RMChile Digestive Disease Center Inflammatory Bowel Disease ProgramClínica Universidad de los AndesSantiago 7620157Chile department of Gastroenterology Universidad de Chile-Hospital San Juan de DiosSantiago 770123Chile

For ulcerative colitis(UC),the variability in inflammatory activity along the colon poses a challenge in *** focus on achieving endoscopic healing in UC is evident,where the UC Endoscopic Index of Severity and Mayo Endoscopic Subscore are commonly used for ***,these indices primarily consider the most severely affected *** et al recent study validates the Toronto Inflammatory Bowel Disease Global Endoscopic Reporting(TIGER)score offering a comprehensive assessment of inflammatory activity across diverse segments of the colon and rectum and a reliable index correlating strongly with UC Endoscopic Index of Severity and moderately with Mayo Endoscopic Subscore(MES).despite recommendation,certain aspects warrant further *** calprotectin,an intermediate target,correlates with TIGER and should be *** TIGER scores defining endoscopic remission and response,evaluating agreement with histological activity,and assessing inter-endoscopist agreement for TIGER require *** the correlation between TIGER and intestinal ultrasound,akin to MES,adds value.

关键词： Ulcerative colitis Sigmoidoscopy Colonoscopy Score index

Generalized Height-Diameter Models for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. Plantations in Michoacan, Mexico

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Open Journal of Forestry 2024年第3期14卷 214-232页

作者： Jonathan Hernández-Ramos Valentín José Reyes-Hernández Héctor Manuel de los santos-Posadas Aurelio Manuel Fierros-González Enrique Buendía-Rodríguez Gerónimo Quiñonez-Barraza Instituto Nacional de Investigaciones Forestales Agrcolas y Pecuarias (INIFAP)-Campo Experimental Bajo Celaya Guanajuato Mxico Colegio de Postgraduados (COLPOS) Campus Montecillo Mxico INIFAP Campo Experimental Valle de Mxico Texcoco Mxico INIFAP Campo Experimental Valle del Guardiana Durango Mxico

Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at the stand level is a valuable support tool in forest inventories. The objective was to fit and propose a generalized H-d model for Pinus montezumae and Pinus pseudostrobus established in forest plantations of Nuevo San Juan Parangaricutiro, Michoacan, Mexico. Using nonlinear least squares (NLS), 10 generalized H-d models were fitted to 883 and 1226 pairs of H-d data from Pinus montezumae and Pinus pseudostrobus, respectively. The best model was refitted with the maximum likelihood mixed effects model (MEM) approach by including the site as a classification variable and a known variance structure. The Wang and Tang equation was selected as the best model with NLS;the MEM with an additive effect on two of its parameters and an exponential variance function improved the fit statistics for Pinus montezumae and Pinus pseudostrobus, respectively. The model validation showed equality of means among the estimates for both species and an independent subsample. The calibration of the MEM at the plot level was efficient and might increase the applicability of these results. The inclusion of dominant height in the MEM approach helped to reduce bias in the estimates and also to better explain the variability among plots.

关键词： Random Covariate Random Effects Variance Structure Forest Inventories Forest Management Mixed Models

demographic and behavioral responses of the White-winged Dove to human disturbances during winter in northwestern Mexico

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Avian Research 2022年第4期13卷 437-444页

作者： Ruben Ortega-Alvarez Jovani Le on-Aguilar Antonio Isain Contreras-Rodríguez Gustavo Casta neda de los santos Instituto de Investigaciones en Ecosistemas y Sustentabilidad(IIES)-Universidad Nacional Autonoma de Mexico Campus MoreliaAntigua Carretera a Patzcuaro 8711Col.San Jose de la HuertaMoreliaMichoacan58190Mexico Programa de Aves Urbanas(PAU) Los MochisSinaloaMexico Quirino Mendoza#320 Colonia del CarmenXochimilcoCiudad de Mexico16720Mexico departamento de Educacion Ambiental Jardín Bot anico Benjamin Francis JohnstonSinaloaMexico

The simultaneous study of demography and behavior might provide a more comprehensive understanding about animal responses to anthropogenic *** White-winged Dove(Zenaida asiatica)is a frequent dweller of urban and agricultural habitats in North America,Central America,and the ***,research on the species is heavily biased to the *** analyzed the response of the species to human disturbances during winter across an urban-agricultural landscape in northwestern Mexico through a demographic and behavioral *** modeled the effect of disturbance types(pedestrians,cars,pavement and building cover)on the density of the ***,we investigated if surveillance behavior varied across the landscape by estimating and comparing perching proportion among land uses(urban grey areas,urban green areas,cropfields,shrublands).We did not detect the species within cropfields,possibly because food resources were not available for the dove during winter in this land *** cover limited species’density,as it might reduce the surface of the preferred feeding substrates of the *** and building cover increased the density of the species,as they might provide food and shelter for the dove,*** behavior peaked in urban grey areas,whereas it dropped in urban green *** on threat levels,threat type,and protective cover among land uses might in-fluence such behavioral *** approach contributes to the knowledge of the species and demonstrates that both demographic and behavioral cues provide complementary evidence for analyzing the impact of human disturbances on animals.

关键词： Agriculture density Perch Sinaloa Urbanization Zenaida asiatica

development and psychometric evaluation of the nurse behavior toward confirmed and suspected HIV/AIDS patients (NB-CSHAP) scale

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Frontiers of Nursing 2022年第1期9卷 103-113页

作者： Janet Alexis de los santos Norberto Milla Cyruz Tuppal Leodoro Labrague department of Nursing Visayas State UniversityViscaLeyte 6521Philippines Graduate School St Paul University PhilippinesTuguegaraoCagayan Valley 3500Philippines department of Statistics Visayas State UniversityViscaLeyte 6521Philippines College of Health Allied and Medical Professions University of San AgustinTuguegaraoIloiloVisayas 5000Philippines Fundamentals and Administration department Sultan Qaboos UniversityMuscatMuscat 112Oman

There is a scarcity of literature discussing nurses’ behaviors toward caring for suspected or confirmed human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients. The development of a scale specific to measure nurses’ behaviors will allow health institutions to assess the disposition of their nurses in terms of HIV care. This study aims to present the rigors of developing and validating a reliable instrument to contextualize these nurses’ behaviors. This study utilized a sequential exploratory mixed method design to develop the NB-CSHAP scale. Thematic analysis was done on the qualitative data from the interviews with persons living with HIV/AIDS (PLHA) from which items were selected to be included in the scale. Exploratory factor analysis was utilized to extract the factors and Cronbach’s alpha was used to assess the reliability of the instrument. Four factors were extracted and are categorized as either caring or discriminatory behaviors. These include: (1) service-oriented, (2) openhanded, (3) perceptive, and (4) discriminatory. The scale has an internal consistency of 0.73. The scale shows acceptable psychometric properties, hence can be used to assess the nurses’ behaviors in caring for confirmed or suspected HIV clients. The scale may be used by health institutions to determine the quality of the patient care provided by their nurses to clients with confirmed or suspected HIV .

关键词： caring behaviors HIV/AIDS care nursing scale development sequential exploratory mixed method design

Probing intensity-field correlations of single-molecule surface-enhanced Raman-scattered light

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Frontiers of physics 2019年第6期14卷 15-26页

作者： O.de los santos-Sanchez Instituto de Ciencias Físicas Universidad Nacional Autónoma de MéxicoApdo.Postal 48-3CuernavacaMorelos 62251México

In the context of the quantum-mechanical description of single-molecule surface-enhanced Raman scattering,intensity-field correlation measurements of photons emitted from a plasmonic cavity are explored,theoretically,using the technique of conditional homodyne *** inelastic interplay between plasmons and vibrations of a diatomic molecule placed inside the cavity can be manifested in phase-dependent third-order fluctuations of the light recorded by the aforesaid technique,allowing us to reveal signatures of non-classicality(indicatives of squeezing)of the outgoing Raman photons.

关键词： Raman scattering SERS phase-dependent fluctuations squeezing plasmonics

Predictive roles of organizational and personal factors in work engagement among nurses

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Frontiers of Nursing 2022年第4期9卷 379-387页

作者： Charlie C.Falguera Leodoro J.Labrague Janet Alexis A.de los santos Carmen N.Firmo Konstantinos Tsaras School of Health Sciences University of the Philippines ManilaLeyteManila 2801Philippines School of Nursing Loyola University ChicagoIllinois 60660United States College of Nursing Visayas State UniversityBaybayLeyte 6521APhilippines department of Nursing Technological Educational Institute of ThessalyKarditsaThessaly 43100Greece

Objective:To determine the work engagement levels of hospital nurses and the predictive roles that nurses’personal and organizational characteristics ***:A cross-sectional design was employed in this study,which included 549 nurses working in the Central *** were selected through purposive sampling,and a self-repor t questionnaire outlining personal and organizational characteristics was *** Utrecht Work Engagement Scale(UWES)was applied to gather data about nurse ***:The dedication score was the highest among the three dimensions of engagement while the vigor score was the ***,Filipino nurses experienced an average level of work *** observed significant relationships between a nurse’s age,years of experience in nursing,years in their present unit,and their position at work and their levels of engagement,vigor,sense of dedication,and *** capacity was a negative predictor of vigor,dedication,absorption,and overall work *** ther,the type of nursing contract was a negative predictor of vigor and *** type of hospital and the nurse’s position were positive predictors of vigor,dedication,and ***:Filipino nurses were satisfactorily engaged at work.A number of nurses’personal and organizational characteristics play a predictive role in their work ***,nursing administrators must suppor t,develop,and implement activities and measures that engage nurses at work.

关键词： Filipino nurses nurse personal factors organizational factors work engagement work engagement predictors