Ag-NP-Decorated Carbon Nanostructures: Synthesis, Characterization, and Antimicrobial Properties.

As the global urgency for effective antimicrobial agents intensifies, this work harnesses the widely demonstrated antimicrobial activity of silver nanoparticles (Ag-NPs) and proposes alternative synthesis approaches to metal-organic hybrid systems with antimicrobial activity. In this study, the proposed synthesis route involves decorating metallic nanoparticles into organic substrates without previous doping. The synthesis simultaneously uses polyethylene glycol for three crucial purposes: (1) acting as a mild reducing agent to generate Ag-NPs with a spherical shape and diameters ranging from 10 to just over 20 nm, (2) functioning as a dispersing agent for flakes of commercial nanostructured carbon supports, including reduced graphene oxide (rGO, ID-nano), and commercial carbon nanoplatelets from Sigma-Aldrich (GNPs, Sigma-Aldrich), and (3) serving as a promoter for the homogeneous anchoring of Ag-NPs in the carbon lattice without altering the conformation of the carbon lattice. This intricate interaction involves the π-orbitals from the sp2 hybridization honeycomb and the d-orbitals from the Ag-NPs, leading to the constructive rehybridization of rGO and GNPs. In our study, Ag-NPs/rGO are compared with a support lacking oxygenated groups in the lattice, such as commercial GNPs (Sigma-Aldrich), to produce Ag-NPs/GNPs. This comparison maintains constructive sp2 rehybridization, preserving the characteristic properties of rGO (ID-nano) and graphene nanoplatelets, including commercial GNPs (Sigma-Aldrich). Notably, oxygenated groups from rGO exhibit greater availability for exchanging oxo and hydroxy defects for Ag-NPs compared with GNPs (Sigma-Aldrich). The resulting Ag-NPs/rGO and Ag-NPs/GNP systems are thoroughly physicochemically characterized, employing techniques such as Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, and scanning transmission electron microscopy, revealing the successful integration of Ag-NPs with minimal alteration to the carbon lattice. Subsequent antimicrobial evaluation against Escherichia coli (E. coli) demonstrates significant activity, with Ag-NPs/rGO and Ag-NPs/GNPs registering similar minimum inhibitory concentrations of 50 µg mL-1. This study underscores the potential of our metal-organic hybrid systems as antimicrobial agents and provides insights into the constructive rehybridization process, paving the way for diverse applications in the biomedical and environmental fields.

Suicides among Children and Adolescents in Paraguay: An 18-year National Exploratory Study (2004-2022).

BACKGROUND: Suicide and suicide attempts are impacting events for patients and their relatives, and these behaviors are still taboo among adults and may be even more traumatic when involving children and adolescents. AIM: In this study we aimed to describe suicide rates among children and adolescents in Paraguay over the last decades as well as associated factors such as sociodemographic characteristics and methods used for suicide. METHODS: This was an observational and exploratory study describing the frequency and characteristics of suicide among children and adolescents in Paraguay between 2004 and 2022. Official records of all deaths by suicide were reviewed, and statistical analyses were performed. In addition, an attempt was made to predict the number of suicides in the next 5 years using a mathematical model based on simple linear regression. RESULTS: In the 18-year period observed, 940 suicides among children and adolescents were recorded. The mean age was 15.05 ± 1.8 years old. Of these, 51.17% were male, 74.6% were from urban areas, and 22.2% were from the Greater Asunción and Central Department of Paraguay. The most frequently used method of suicide was intentional self-inflicted injury by hanging, strangulation, or suffocation, which all represented 75.3% of the cases. Our mathematical modeling based on simple linear regression determined that the expected yearly number of national suicides in the pediatric population for the following years, from 2023 to 2027, will range between 72 and 81. CONCLUSION: This study is the first large national epidemiological report on the emerging issue of suicide among children and adolescents in Paraguay. It may be a relevant source of information for mental health professionals, health authorities, and decision makers to develop national prevention strategies and actions against suicide among youths.

Social Determination of the Health of Families from Two Neighborhoods in Medellín, Colombia.

OBJECTIVES: To understand the health process, from the approach of the social determination of health in two neighborhoods in Medellín - Colombia, to contribute to the care of people, families, and collectives in their multidimensional reality. METHODS: Qualitative research from the ethnographic perspective, approaching the general dimension with documentary analysis of social policies and community documents, the particular dimension through focal groups and interviews to community leaders, and the singular dimension with the family visit. RESULTS: Families and collectives live within a sociocultural setting of resistance, overshadowed by moments of flight and displacement derived from violence, with scant participation in city plans and programs and with structural problems of economic and political exclusion. They constructed the territory as space and shelter in the weave that protects and violates them, with processes from uprooting to rooting. The families have maintained protective processes, like family participation in decision making, knowledge on health care, among others, and destructive processes, like informal labor and job instability, without spaces for recreation and with limitations in transportation, in access to health programs and in obtaining food. CONCLUSIONS: The health of the families has been determined by historical exclusion to work to obtain resources for a minimum vital subsistence, which is why they suffer social vulnerability due to few opportunities for development; they have lived a transformation process of the territory with resistance, solidarity, and construction of social networks.

Social Determination of the Health of Families from Two Neighborhoods in Medellín, Colombia / Determinación social de la salud de las familias de dos barrios de Medellín, Colombia / Determinação social da saúde das famílias em dois bairros de Medellín, Colômbia

Objective. To understand the health process, from the approach of the social determination of health in two neighborhoods in Medellín - Colombia, to contribute to the care of people, families, and collectives in their multidimensional reality. Methods. Qualitative research from the ethnographic perspective, approaching the general dimension with documentary analysis of social policies and community documents, the particular dimension through focal groups and interviews to community leaders, and the singular dimension with the family visit. Results. Families and collectives live within a sociocultural setting of resistance, overshadowed by moments of flight and displacement derived from violence, with scant participation in city plans and programs and with structural problems of economic and political exclusion. They constructed the territory as space and shelter in the weave that protects and violates them, with processes from uprooting to rooting. The families have maintained protective processes, like family participation in decision making, knowledge on health care, among others, and destructive processes, like informal labor and job instability, without spaces for recreation and with limitations in transportation, in access to health programs and in obtaining food. Conclusion. The health of the families has been determined by historical exclusion to work to obtain resources for a minimum vital subsistence, which is why they suffer social vulnerability due to few opportunities for development; they have lived a transformation process of the territory with resistance, solidarity, and construction of social networks.

Objective. To understand the health process, from the approach of the social determination of health in two neighborhoods in Medellín - Colombia, to contribute to the care of people, families, and collectives in their multidimensional reality. Methods. Qualitative research from the ethnographic perspective, approaching the general dimension with documentary analysis of social policies and community documents, the particular dimension through focal groups and interviews to community leaders, and the singular dimension with the family visit. Results. Families and collectives live within a sociocultural setting of resistance, overshadowed by moments of flight and displacement derived from violence, with scant participation in city plans and programs and with structural problems of economic and political exclusion. They constructed the territory as space and shelter in the weave that protects and violates them, with processes from uprooting to rooting. The families have maintained protective processes, like family participation in decision making, knowledge on health care, among others, and destructive processes, like informal labor and job instability, without spaces for recreation and with limitations in transportation, in access to health programs and in obtaining food. Conclusion. The health of the families has been determined by historical exclusion to work to obtain resources for a minimum vital subsistence, which is why they suffer social vulnerability due to few opportunities for development; they have lived a transformation process of the territory with resistance, solidarity, and construction of social networks.

Objetivo. Compreender o processo de saúde, a partir da abordagem da determinação social da saúde em dois bairros de Medellín, para contribuir com o cuidado de indivíduos, famílias e grupos em sua realidade multidimensional. Métodos. Pesquisa qualitativa na perspectiva etnográfica; abordou a dimensão geral com análise documental de políticas sociais e documentos comunitários, a dimensão particular por meio de grupos focais e entrevistas com lideranças comunitárias e a dimensão singular com a visita familiar. Resultados. Famílias e grupos vivem em um espaço sociocultural de resistência, matizado por momentos de fuga e deslocamento derivados da violência, com pouca participação nos planos e programas da cidade e com problemas estruturais de exclusão econômica e política. Construíram o território como espaço e refúgio na urdidura que os protege e os viola, com processos de desenraizamento ao enraizamento. As famílias têm mantido processos protetivos como a participação da família na tomada de decisões, o conhecimento dos cuidados de saúde, entre outros, e processos destrutivos como o trabalho informal e a precarização do emprego, sem espaços de lazer e com limitações no transporte, no acesso aos programas de saúde e na obtenção de alimentos. Conclusão. A saúde das famílias tem sido determinada pela exclusão histórica do trabalho para obtenção de recursos para um mínimo vital de subsistência, pelo qual sofrem vulnerabilidade social devido às escassas oportunidades de desenvolvimento; vivenciaram um processo de transformação do território com resistência, solidariedade e construção de redes sociais.

Studies on aquatic fungi in Dikarya: a review of the literature from Southern Cone of South America.

A bibliographic analysis was carried out to update the state of knowledge about aquatic fungi belonging to the subkingdom Dikarya in the Southern Cone of South America. The exhaustive search resulted in 38 articles reported. These papers correspond to those on taxonomic, ecological and biogeographic topics and include studies from lotic environments of the temperate ecoregions of Chile and Argentina. A total of 325 aquatic fungal taxa were reported, of which 318 belong to the phylum Ascomycota and 7 to the phylum Basidiomycota. According to the subgroups of these aquatic fungi 17 taxa were aero-aquatic, 199 facultative and 109 Ingoldian fungi. Regarding the methodologies, in these studies the information was obtained mainly by using lignocellulosic substrates such as leaf litter and wood as fungal source and wet chamber traditional working technique. However, more studies are still needed using other few-reported perspectives for the region such as ecological and molecular approaches as well as analyses of water environments belonging to unexplored biomes. This information can contribute to a better understanding of aquatic fungal communities and their role in ecosystems of the Southern Cone of South America.

Translocation of Epipelic Biofilms and Their Short-Term Responses to Urbanization Impacts in Nutrient Rich Streams.

Stream biofilms are among the first to react to environmental degradation, since their structural and functional characteristics are tightly linked to the physicochemical variables in the water and sediment. The objectives of this research were to study the differences in chlorophyll-a, bacterial density and metabolism endpoints of epipelic biofilms in nutrient-rich streams under different physical-chemical conditions in the stream water in relation to changes in urbanization, and to measure the short-term responses (up to 72 h) in the biofilm when translocated to more urbanized sites. For these purposes, chlorophyll-a, bacterial density, biofilm respiration (electron transfer activity) and O2 consumption were measured in epipelic biofilms in nutrient-rich streams exposed to different levels of urbanization after a 30 day colonization. Afterward, biofilms were translocated downstream to more polluted sites, and sampled to identify any fast occurring changes to be considered as potential indicators of environmental degradation. Results show that in the nutrient-rich streams studied, the structural characteristics of the biofilm were linked to urbanization, and even after a short time following the translocation, chlorophyll-a and bacterial density varied, reflecting the environmental degradation. On the other hand, metabolic variables were highly variable and produced inconsistent results when representing an increase in urbanization.

Temporal patterns in the abundance, type and composition of microplastics on the coast of the Río de la Plata estuary.

The objective was to establish possible temporal patterns in the microplastics (MPs) abundance in the water and in the intertidal sediment in an urbanized location of the Río de la Plata estuary (Argentina), in relation to environmental factors. The site was sampled monthly for a year (February 2019-January 2020). The presence of MPs was recorded, being more abundant in February in the water (110 MPs m-3) and in April in the sediment (613 MPs m-2). The types of MPs found were fibers, fragments, pellets, film and foam; while the polymers identified were polyethylene (PE) and polypropylene (PP). Regarding the environmental variables, the predominance of wind from the NE direction was related to a greater accumulation of MPs in the sediment, while wind from the NO direction was associated with a lower abundance of MPs in the water. Also, MPs abundance was negatively related to the larger sizes of sediment particles.

Consumo de tabaco, alcohol y otras sustancias y su relación con predictores de riesgo para la salud mental, en estudiantes del área de la salud. medellín, colombia

Objetivo: Describir la prevalencia de consumo de tabaco, alcohol y otras sustancias en su relación con predictores de riesgo para la salud mental, en estudiantes de salud de una universidad pública. Metodología: tipo cuantitativa, descriptiva, transversal. Se seleccionaron 3020 estudiantes de nueve (9) facultades de salud. A través de un muestreo por conglomerados proporcional al número de estudiantes por facultad, se utilizó un cuestionario compuesto de cuatro partes: una con variables sociodemográficas y tres test. Resultados: AUDIT: de los 1726 estudiantes que respondieron la encuesta 80,4 % está en la zona de riesgo I, por lo que se sugiere educación sobre el alcohol; el 0,9 % se ubicó en la zona IV, se aconseja la derivación a especialista. FAGESTRÖM: los que respondieron (n=196), el 88,3 % puntuaron como fumador poco dependiente; el 8,2 % de ellos presentaron riesgo de dependencia. DUSI: en relación con el consumo de sustancias ilícitas, la marihuana tiene el consumo más alto (n=554), el 72,3 % lo hizo de forma experimental; el 8,5 % lo realizó de forma compulsiva. Conclusión: los datos encontrados permitieron ver cifras elevadas de consumo perjudicial, por tal motivo es necesario proponer estrategias de intervención oportunas.

Objective. To describe the prevalence of tobacco, alcohol, and other substances and its relationship with predictors of mental health in health students from a public university. Materials and methods. Quantitative, descriptive, cross-sectional. Three thousand twenty students from nine health departments were selected. Cluster sampling is proportional to the number of students per department. A questionnaire of four parts was used: one with sociodemographic variables and three tests. Results. AUDIT: Out of 1726 respondents, 80.4 % were in risk zone I where education on alcohol is suggested and 0.9 % were in zone IV, referral to a specialist; FAGESTRÖM: Of the respondents (n = 196), 88.3 % scored as slightly dependent smokers and 8.2 % had a risk of dependence. DUSI: About the use of controlled substances, marijuana has the highest consumption (n = 554); 72.3 % used it experimentally and 8.5 % did it compulsively. Conclusion. The data revealed high figures of harmful use; therefore, it is necessary to propose timely intervention strategies.

Recurrent pattern of picophytoplankton dynamics in estuaries around the world: The case of Río de la Plata.

The picoplankton is an important component of aquatic food webs and plays a significant biogeochemical and ecological role in the environment. Little is known about this fraction of the plankton in temperate estuaries and especially in South America. In this article, we study the absolute and relative importance of the picoplankton along an annual cycle, and their relationship with physical and chemical variables in the Río de la Plata estuary. We also review the existing research in estuaries around the world concerning this community and present our results in a global context. The seasonal variation in the abundance of the different groups analyzed was very noticeable. Phycocyanin-rich picocyanobacteria (Pcy) were the main component (in abundance and in biovolume) of the picophytoplankton (PPP) almost during the whole year, with a maximum abundance of 7.3 × 105 cell mL-1 in summer, three orders of magnitude higher compared to autumn-winter. Picoeukaryotes, larger phytoplankton and heterotrophic bacteria showed the same seasonal trend, although with a lower range of variation than that of the Pcy. Considering all the phototrophic planktonic fractions, in terms of biomass, the PPP reached a maximum of 43% of the total biomass in spring. The dynamics of PPP found in this area are consistent with the observed in other temperate estuaries, where temperature is the main variable that influences its development, and with a high seasonal variation. Additionally, the absolute and relative importance of Pcy showed a consistently increasing trend towards lower latitude estuaries. The review also showed us that there is scarce information related to the picoplankton fraction in the Southern Hemisphere, its sanitary implications due to their potential of toxicity or their ecological role in coastal zones. The results presented here show the importance of this fraction, not only in Río de la Plata, but in many estuaries of the world, with a clear increase of relative abundance as we approach the equator.

Assemblage of dematiaceous and Ingoldian fungi associated with leaf litter of decomposing Typha latifolia L. (Typhaceae) in riverine wetlands of the Pampean plain (Argentina) exposed to different water quality.

The purpose of this study was to analyze the rate of sporulation, richness, and spore diversity of dematiaceous and Ingoldian fungi colonizing Typha latifolia leaves during a 40-day period of decomposition, as well as the loss of mass in Typha latifolia, in four riverine wetlands of Pampean plain (Argentina) with different water quality. Higher sporulation rates, richness, and diversity of the fungi as well as loss of mass of the leaves that they colonized were associated with lower water quality. Anguilospora longissima, Arthrinium sp., Margaritispora aquatica, and Tricellula botryosa were dominant taxa. Redundancy analysis showed two fungal assemblages related to different environmental conditions. One assemblage was related to higher nutrient levels and higher temperature, characterized mainly by dematiaceous fungi. The other assemblage was related to higher levels of pH and dissolved oxygen, which was mainly represented by Ingoldian fungi. The results obtained in our study demonstrated the link between these fungal assemblages and changes in water quality, revealing their potential as indicators of environmental changes in rivers exposed to different types of land use.

La era de los microorganismos multirresistentes: impacto en pacientes neutropénicos febriles / he era of multidrug-resistant microorganisms: impact on febrile neutropenic patients

Introducción: El tratamiento antimicrobiano para los pacientes neutropénicos febriles (NF) se ha convertido en un desafío debido a la emergencia de microorganismos multirresistentes (MOR). El objetivo de este trabajo es analizar las características de estos pacientes y la incidencia de MOR. Materiales y métodos: Estudio retrospectivo, observacional y descriptivo desde junio de 2015 hasta agosto de 2017 en adultos neutropénicos febriles hospitalizados en un hospital público de la ciudad de Buenos Aires. Se analizaron características demográficas, clínicas y microbiológicas, incluyendo los siguientes MOR: enterobacterias productoras de carbapenemasas (EPC) y beta-lactamasas de espectro extendido (BLEE), Acinetobacter baumannii complex, Enterococcus vancomicina resistente (EVR) y Stenotrophomonas maltophilia. Resultados: Fueron incluidos 32 pacientes, 56% mujeres con 84% de neoplasias hematológicas. Hubo colonización por EPC o EVR en el 59% de los pacientes. Se registraron 148 episodios infecciosos con 41% de documentación microbiológica. Los MOR fueron responsables del 25% de los episodios, siendo los más frecuentes Klebsiella pneumoniae productora de carbapenemasa y BLEE; los focos más frecuentes fueron bacteriemias e infecciones urinarias. Los pacientes con leucemias agudas (67%) presentaron colonización por EPC o EVR en el 80%. El tratamiento fue inadecuado en el 63% de las infecciones RESUMENARTÍCULO ORIGINALpor MOR y en el 12% por microorganismos sensibles (MS) (p<0,01). La mortalidad global fue 53% con MOR y del 27% con MS (p=ns). Conclusión: las infecciones por MOR fueron frecuentes con predominio de bacteriemias, especialmente EPC y BLEE. Por ello los MOR deben ser tenidos en cuenta para el tratamiento empírico en pacientes neutropénicos febriles

Background: Antimicrobial treatment for febrile neutropenic (FN) patients has become a challenge due to the growing emergence of multidrug-resistant microorganisms (MDR-MO). The objective of this study was to analyze the characteristics of these population and the incidence of MDR-MO. Methods & Materials: Retrospective, observational and descriptive study from June 2015 to August 2017 in FN adults hospitalized at a public hospital in Buenos Aires city, Argentina. Demographic, clinical and microbiological characteristics were analyzed. We included the following MDR-MO: extended spectrum beta-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae (CPE), Acinetobacter baumannii complex, vancomycin resistant Enterococcus (VRE) and Stenotrophomonas maltophilia. Results: Thirty-two patients were included; 56% were women, with 84% haematological diseases. Colonization by CPE or VRE was observed in a 59% of the patients. There were 148 infectious episodes. Of them 41% had microbiological documentation. MDR-MO were responsible for 25% of the episodes and the most frequent were carbapenemase-producing Klebsiella pneumoniae and ESBL producing Enterobacteriaceae. MDR-MO were isolated mainly from bacteremia and urinary infections, patients had acute leukemia in a 67% and colonization CPKP or VRE in 80%. Inadequate treatment for MDR-MO was observed in 63% of the cases and 12% for susceptible microorganisms (p<0,01). The mortality was 53% for MDR-MO and 27% for susceptible microorganisms (p=ns). Conclusion: MDR-MO infections were frequent with predominance of bacteremia especially CPE and ESBL producing Enterobacteriaceae. According to these results MDR-MO should be taken into account for the empiric antimicrobial treatment in febrile neutropenic patients

Enzymatic hydrolysis of cellulose nanoplatelets as a source of sugars with the concomitant production of cellulose nanofibrils.

Cellulose, the most abundant biopolymer on earth, is produced at different ratios by all land plants. Since the morphology and crystallinity of cellulose are key factors involved in its enzymatic hydrolysis, in the present work, we tackled the study of the effects of such variables on the nanocellulose conversion into glucose. Cellulase from Trichoderma sp at 37 °C was used to produce glucose, the best results were found for the cellulose nanoplatelets (S-CNP) after 60 h of hydrolysis, which afforded a conversion of 47% to glucose, in contrast to 15% for the non-purified sample (W-CP) and 22% for microcrystalline cellulose (MCC20) used as control. The X-ray diffractogram recorded on the samples showed an initial crystallinity index of 45%, 54% and 72% for W-CNP, S-CNP and MCC20, respectively. Also, we showed that after 24 h of hydrolysis, long cellulose nanofibrils (∅ ≈ 30 nm) were found as a residue.

Bacteriemia por Klebsiella pneumoniae productora de carbapenemasa tipo KPC. Estudio comparativo y evolución en 7 años / Bacteremia caused by Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae. A retrospective study of 7 years

Introducción: La bacteriemia por Klebsiella pneumoniae productora de carbapenemasa tipo KPC (Kp-KPC) se asocia a elevada mortalidad. La hipótesis de nuestro trabajo es que hubo aumento en los niveles de resistencia a diferentes antimicrobianos en Kp-KPC en bacteriemias. El objetivo del presente estudio es describir las características clínicas, microbiológicas, esquemas terapéuticos y evolución de las bacteriemias por Kp-KPC en nuestro hospital. Materiales y métodos: Estudio retrospectivo y descriptivo en dos periodos: Periodo 1 (P1) 2010-2014 y periodo 2 (P2) 2015-2016. Se incluyeron pacientes ≥ 18 años con bacteriemia por Kp-KPC en un Hospital General de Agudos. Se definió como antimicrobiano activo aquel que presentaba sensibilidad en el antibiograma y en el caso particular de meropenem cuando presentaba CMI ≤ 8 mg/L y era utilizado en tratamiento combinado Resultados: Se analizaron 50 episodios (P1: 21 y P2: 29) de bacteriemia por Kp-KPC en 45 pacientes. Las siguientes variables fueron semejantes en ambos periodos: edad mediana (53 vs. 52 años); sexo masculino (45 vs. 62%); sitio de infección: bacteriemia primaria (52 vs. 45%), bacteriemia asociada a catéter (24 vs. 17%), otros (24 vs. 38%). En el P2 se registró un aumento significativo de resistencia a colistina (28 vs. 69%) (p<0,01), un aumento de aislamientos con CMI a meropenem ≥ 16 mg/L (74 vs. 97%) (p=0,02) y una disminución de resistencia a tigeciclina (29 vs. 4%) (p=0,02). La mortalidad global fue del 40 en el P1 y 32% en el P2 (p=0,7). En ningún periodo se observó diferencia en la mortalidad cuando el tratamiento dirigido fue con un antimicrobiano activo vs. dos antimicrobianos activos, así como tampoco entre los diferentes antimicrobianos utilizados. Conclusiones: Se observó un aumento significativo de las bacteriemias por Kp-KPC y del nivel de resistencia a colistina y de las CMIs a meropenem. Para ambos períodos la mortalidad fue elevada

Introduction: Bacteremia caused by Klebsiella pneumoniae carbapenemase-producing strains (Kp-KPC) is associated with high mortality. The hypothesis of our work is that there was an increase in the levels of resistance to different antimicrobials in Kp-KPC isolated from bacteremia. Materials and methods: Retrospective and descriptive study in two periods: Period 1 (P1) 2010-2014 and period 2 (P2) 2015-2016. We included patients ≥18 years old with bacteremia caused by Kp-KPC in a General Hospital. We defined active drug (AD) if it was in vitro susceptible and in the case of meropenem if it had a MIC ≤ 8 mg/L in combination treatment. Results: Fifty episodes of bacteremia caused by Kp-KPC were analyzed in 45 patients. (P1: 21 and P2: 29). The following variables were similar in both periods: median age (53 vs. 52 years); male sex (45 vs. 62%); site of infection: primary bacteremia (52 vs.45%), bacteremia associated with catheter (24 vs.17%), and other (24 vs. 38%). During P2 there was a significant increase in colistin resistance (28 vs. 69%) (p <0.01), an increase in MIC to meropenem ≥ 16 mg/L (74 and 97%) (p = 0.02), and decrease in tigecycline resistance (29 vs. 4%) (p = 0.02). The overall mortality was 40 in P1 and 32% in P2 (p=0.7). There was not difference in mortality when the definitive treatment was with an active antimicrobial vs. two active antimicrobials, as well as between the different antimicrobials used. Conclusions: There was a significant increase in bacteremia caused by Kp-KPC and the level of colistin resistance and MIC to meropenem. Overall mortality was high in both periods

Ejercicio físico como tratamiento adyuvante de los trastornos mentales. Una revisión narrativa / Physical exercise as an adjuvant treatment of mental disorders. A narrative review

El ejercicio físico puede ser una herramienta importante para el manejo de personas con enfermedades psiquiátricas, puesto que un notable número de estudios longitudinales y transversales ha demostrado que el mismo se constituye en una estrategia preventiva y en un enfoque adyuvante del tratamiento de los trastornos mentales. En ese sentido, se ha evidenciado que las formas más efectivas de ejercicio físico son los ejercicios aeróbicos (tales como caminar, trotar, andar en bicicleta, nadar, entre otros) y los de fortalecimiento. El objetivo de este artículo es presentar una actualización general acerca del ejercicio físico como tratamiento adyuvante de los trastornos mentales. Esta es una revisión narrativa, no sistemática, centrada en literatura primaria seleccionada de una búsqueda en PubMed, SciELO y LILACS. Los términos clave que se utilizaron fueron los siguientes: "ejercicio físico y salud mental", "fisioterapia y salud mental", "ejercicio físico y trastornos mentales" y "ejercicio físico y psiquiatría". Se complementaron estos artículos con libros y capítulos de libros, resaltando hallazgos duplicados. Todos los miembros del equipo de investigación participaron en la revisión de la literatura. Aunque existen excelentes estudios y revisiones que analizan detalladamente el papel del ejercicio físico en el tratamiento específico de algunos trastornos mentales, se consideró que se necesitaba una revisión más general para brindar orientación a médicos psiquiatras y a fisioterapeutas en este campo de integración de la salud física y mental.

Physical exercise can be an important part of the management of people with psychiatric illnesses, since a considerable number of longitudinal and cross-sectional studies has shown that it constitutes a preventive strategy and an adjuvant approach to the treatment of mental disorders. In that sense, it has been demonstrated that the most effective forms of physical exercise are aerobic exercises (such as walking, jogging, cycling, swimming, among others) and strengthening. The aim of this article is to present a general update about physical exercise as an adjuvant treatment of mental disorders. This is a narrative review, not systematic, focused on primary literature selected from a search in PubMed, SciELO and LILACS. The key terms used were: "physical exercise and mental health", "physiotherapy and mental health", "physical exercise and mental disorders" and "physical exercise and psychiatry." These articles were supplemented with books and book chapters, highlighting duplicate findings. All members of the research team participated in the review of the literature. Although there are excellent studies and reviews that analyze in detail the role of physical exercise in the specific treatment of some mental disorders, it was considered that a more general revision was needed to provide guidance to psychiatrists and physiotherapists in this field of integration of physical and mental health.

Microplastics integrating the coastal planktonic community in the inner zone of the Río de la Plata estuary (South America).

This study explores in plankton samples the abundance, distribution, size, types (fibres and fragments), colours of the microplastics (MPs) and its relation with the characteristics of the plankton (size and morphology) of the Río de la Plata estuary. Water samples were collected in triplicate in freshwater-mixohaline tidal zone of the estuary, in ten sampling sites located along 150 km of coast, in two periods (September-November 2016 and April-June 2017). The results revealed the presence of MPs in all the samples analysed, with a dominance of fibres and sizes >500 ≤ 1000 µm, and blue colour being more frequent. The MPs distribution was significantly different among sampling sites, being more abundant in the most urbanized sites, sewage discharges and near the maximum turbidity front. The mean density, in the two samplings analysed, were 164 and 114 MPs m-3. The fibres amount was significantly different among sites. The MPs integrated a planktonic community dominated by pico-microphytoplankton, mainly conformed by filaments/chains and solitary forms and by micro-mesozooplankton. The comparative analysis of plankton and MPs demonstrated that a fraction of the latter showed a frequency range of size that coincides with the most common sizes of plankton (≤500 µm). The mean percentage of MPs items in relation to zooplankton was 0.36% (sampling 1) and 1.20% (sampling 2) and for phytoplankton was 0.0002% (sampling 1) and 0.0005% (sampling 2). The correlations between the MPs concentration and habitat quality (IHRPlata index) were statistically significant, on the contrary correlations between the MPs concentration and measured environmental variables were not found. The findings of this study emphasises the need for a better treatment of urban waste, which would contribute to reducing the entry of this pollutant into the ecosystem. The presence of microplastics in plankton samples on the coast of the Río de la Plata estuary.

Effects of hexavalent chromium on phytoplankton and bacterioplankton of the Río de la Plata estuary: an ex-situ assay.

We examined the responses of the phytoplankton and the bacterioplankton of the freshwater zone of the Río de la Plata estuary when exposed to an addition of hexavalent chromium (Cr+6). The planktonic community from a coastal site was exposed to a chromium increase of 80 µg L-1 for 72 h in laboratory conditions. The results showed a decrease in the concentration of Cr+6 by 33% in the treatments, along with significant decreases in chlorophyll-a (63%), the chlorophyll-a:pheophytin-a ratio (33%), oxygen production (37%), and in the total density of the phytoplankton (15%). The relative abundance of chlorophytes and diatoms decreased, while the cyanobacteria thrived. Finally, the total bacterial density and the density of viable bacteria decreased. These results show that even small increments in Cr+6 can cause significant effects on the phytoplankton and bacterioplankton, which could potentially affect other trophic levels of the community, risking alterations of the entire ecosystem.

Microplastics in gut contents of coastal freshwater fish from Río de la Plata estuary.

The presence of microplastics (MPs) in gut contents of coastal freshwater fish of the Rio de la Plata estuary was studied. Samples were taken in six sites where 87 fish belonging to 11 species and four feeding habits were captured. Presence of MPs was verified in the 100% of fish. The fibres represented the 96% of MPs found. The number of MPs in gut contents was significantly higher close to sewage discharge. There was not found relationship between number of MPs and fish length, weight or feeding habit. The spatial differences in mean number of MPs in fish observed in this study, suggest that environmental availability of MPs could be of great importance to explain the differences found among sampling sites analysed. This work represents the first study about the interaction between MPs and aquatic organisms in this important estuarine ecosystem of South America.

Ultrasonic irradiation-assisted synthesis of Bi2S3 nanoparticles in aqueous ionic liquid at ambient condition.

In this work, an easy, fast and environmentally friendly method to obtain Bi2S3 nanostructures with sphere-like morphology is introduced. The promising material was successfully synthesized by a sonochemical route in 20% 1-ethyl-3-methylimidazolium ethyl sulfate [EMIM][EtSO4] ionic liquid solution (IL). Morphological studies by electron microscopy (SEM and TEM) show that the use of IL in the synthesis of Bi2S3 favors the formation of nanocrystals non-agglomerated. Micro Raman and energy dispersive X-ray spectroscopy (EDXS) were used to determine the composition and purity of the synthesized material. X-ray powder diffraction (XRD) and selective area electron diffraction (SAED) revealed that ultrasonic radiation accelerated the crystallization of Bi2S3 into orthorhombic bismuthinite structure. The band gap calculated from the diffuse reflectance spectra (DRS) was found to be 1.5eV.

Effects of pulse and press additions of salt on biofilms of nutrient-rich streams.

Chronic and pulse increments of salinity can cause different consequences on the aquatic communities, and its effects are related to factors such as the magnitude, frequency and ionic composition, as well as on the baseline salt concentrations in the water. The aim of this study was to explore the responses of the biofilms from a nutrient-rich stream to both pulse and chronic additions of salt, along with their recovery after the stressor had been removed. For this purpose, a microcosm study was conducted exposing biofilms to water enriched with sodium chloride in two treatments (press and pulse), and comparing the changes in the biofilm with control microcosms without salt additions. The experiment lasted 72h, and the variables measured included bacterial density, chlorophyll-a concentration, community composition, total carbohydrate content, oxygen consumption and the percentage of nuclear alterations in diatoms. Both treatments resulted in a decrease in the bacterial density of the biofilm and in oxygen consumption; the chronic treatment in particular also caused an increased percentage of nuclear abnormalities in the diatom assemblage. The biofilm recovered to control levels after the treatments had been discontinued for 72h. We concluded that the biofilms can be altered significantly under both chronic and pulse additions of salt even after a short-term exposure, and that the community can recover if the stressor is withdrawn.

Sensiblidad antimicrobiana de bacilos gramnegativos de infecciones intraabdominales de la comunidad en un hospital de la ciudad de Buenos Aires, Argentina / Antimicrobial susceptibility of Gram-negative bacilli of community acquired intra-abdominal infections in a hospital at Buenos Aires, Argentina

Introducción. Las infecciones intraabdominales complicadas (IIAC) adquiridas en la comunidad son una patología muy prevalente.Existen pocos datos disponibles en Argentina del nivel de resistencia antimicrobiana de bacilos gramnegativos aislados de IIAs adquiridas en la comunidad. Métodos. Estudio retrospectivo-prospectivo y observacional (marzo 2010 a febrero 2012). Se evaluó la sensiblidad antimicrobiana de bacilos gramnegativos aislados de IIAC de pacientes provenientes de la comunidad. Resultados. Se incluyeron 85 pacientes, de los cuales se aislaron 138 patógenos. Sexo masculino: 58%. Mediana de edad: 33. Se obtuvo aislamiento monomicrobiano en un 49% de los casos. Del total de aislamientos, se aislaron 90 (65%) bacilos gramnegativos y 48 (38%) cocos grampositivos. Las especies de bacilos gramnegativos más frecuentemente observadas fueron: Escherichia coli 76%, Klebsiella pneumoniae 8%, Pseudomona aeruginosa 7% y Enterobacter spp. 6%. E. coli y K. pneumoniae mostraron un elevado porcentaje de cepas resistentes a ciprofloxacino, 37% y 29%, respectivamente. Del mismo modo, la resistencia a ampicilina/sulbactam fue de 16% para E. coli. La frecuencia de bacilos gramnegativos multirresistentes fue de 38%. Conclusiones. Se observó un elevado nivel de resistencia a antimicrobianos en bacilos gramnegativos de IIAC de pacientes provenientes de la comunidad, principalmente a ciprofloxacino y ampicilina/sulbactam. Además se identificó una considerable proporción de bacilos gramnegativos multirresistentes (AU)

Introduction. Community acquired complicated intra-abdominal infections (cIAI) are a common condition. Few data are available about the level of antimicrobial resistance of Gram-negative bacteria isolated from community acquired cIAIs in Argentina. Methods. Retrospective-prospective observational study (March 2010 to February 2012). Gram-negative bacteria antimicrobial susceptibility of isolates from community acquired cIAIs were evaluated. Results. During this period, a total of 85 patients were included and 138 pathogens were collected. Male sex: 58%. Median age: 33. Monomicrobial cultures were obtained in 49% of the cases. Ninety (65%) corresponded to Gram-negative organisms, and 48 (38%) to Gram-positive cocci. Gram-negative organisms most frequently observed were: Escherichia coli 76%, Klebsiella pneumoniae 8%, Pseudomonas aeruginosa 7% and Enterobacter spp. 6%. E. coli and K. pneumoniae showed a high percentage of strains resistance to ciprofloxacin of 37% and 29%, respectively. Similarly, resistance to ampicillin/sulbactam was observed in a 16% of the E. coli isolates. The prevalence of multiresistant Gram-negative organisms was 38%. Conclusions. A high level of resistance to antimicrobials was observed in community acquired cIAIs, mainly to ciprofloxacin and ampicillin/sulbactam two of the most used antimicrobial for empirically treatment of cIAIs in our country. In addition a significant proportion of multiresistant Gram-negative organisms were identified (AU)