Diagnosing the Electrostatic Shielding Mechanism for Dendrite Suppression in Aqueous Zinc Batteries.

Aqueous zinc electrolytes offer the potential for cheaper rechargeable batteries due to their safe compatibility with the high capacity metal anode; yet, they are stymied by irregular zinc deposition and consequent dendrite growth. Suppressing dendrite formation by tailoring the electrolyte is a proven approach from lithium batteries; yet, the underlying mechanistic understanding that guides such tailoring does not necessarily directly translate from one system to the other. Here, it is shown that the electrostatic shielding mechanism, a fundamental concept in electrolyte engineering for stable metal anodes, has different consequences for the plating morphology in aqueous zinc batteries. Operando electrochemical transmission electron microscopy is used to directly observe the zinc nucleation and growth under different electrolyte compositions and reveal that electrostatic shielding additive suppresses dendrites by inhibiting secondary zinc nucleation along the (100) edges of existing primary deposits and encouraging preferential deposition on the (002) faces, leading to a dense and block-like zinc morphology. The strong influence of the crystallography of Zn on the electrostatic shielding mechanism is further confirmed with Zn||Ti cells and density functional theory modeling. This work demonstrates the importance of considering the unique aspects of the aqueous zinc battery system when using concepts from other battery chemistries.

Variables de condición física predictivas de sintomatología depresiva en estudiantes universitarios de Cali, Colombia

Objetivo: Determinar las variables de condición física saludable predictoras de sintomatología depresiva en jóvenes universitarios. Método: Este estudio presenta un diseño observacional descriptivo de corte transversal con una fase multivariada, que utilizó el cuestionario autoadministrado BECK (BDI-2) con el objetivo de determinar sintomatología depresiva, en una muestra de 344 estudiantes universitarios entre 18 y 39 años, matriculados en cuatro diferentes universidades de la ciudad de Santiago de Cali, Colombia. La condición física relacionada con la salud se valoró a partir de la batería Alpha Fit Adultos; con los análisis correlacionales se construyó un modelo de regresión logística binario que pudiera establecer cuáles variables de condición física se asocian a una sintomatología depresiva en este tipo de población. Resultados: Correlaciones inversas y estadísticamente significativas fueron observadas entre el puntaje de depresión del inventario de Depresión de Beck-II, con los indicadores de condición física aeróbica r = -0,202, p=0,000; fuerza prensil media r =-0,113, p=0,036; salto alto r =-0,177, p=0,000; flexión de brazos r =-0,158, p=0,003; y test de figura en 8 r =-0,146, p=0,006). Universitarios con mayores niveles de sintomatología depresiva presentan un fenotipo de menor condición física, principalmente en el indicador de resistencia cardiorrespiratoria (ß=-0,059; p<0,004 Exp (B) 0,942). Conclusiones: Los resultados obtenidos en el presente estudio muestran que un fenotipo asociado a menor condición física cardiorrespiratoria se asocia con mayores niveles de sintomatología depresiva.

Objective: To determine healthy physical condition variables predictive of depressive symptomatology in young university students. Method: This study presents a cross-sectional descriptive observational design with a multivariate phase, which used the self-administered BECK questionnaire (BDI-2) to assess depressive symptomatology in a sample of 344 university students between 18 and 39 years of age, enrolled in four different universities in the city of Santiago de Cali, Colombia. Health-related physical fitness was assessed from the Alpha Fit Adult battery; with the correlational analyses, a binary logistic regression model was constructed to determine which physical fitness variables are associated with depressive symptomatology in this type of population. Results: Inverse and statistically significant correlations were observed between the Beck Depression Inventory-II depression score with aerobic fitness indicator r =0,202, p=0,000; mean prehensile strength r =0,113, p=0,036; high jump r =0,177, p=0,000; push-up r =0,158, p=0,003; and figure-8 test r =0,146, p=0,006). University students with higher levels of depressive symptomatology presented a lower physical fitness phenotype, mainly in the cardiorespiratory endurance indicator (ß=-0,059; p<0,004 Exp (B) 0,942). Conclusion: The results obtained in the present study show that a phenotype associated with lower cardiorespiratory fitness is associated with higher levels of depressive symptomatology.

Prevalence of meeting all three 24-h movement guidelines and its correlates among preschool-aged children.

The aim of the present study was twofold: first, to determine the meeting all three 24-h movement guidelines in Colombian preschool-aged children, and second, to explore the associations between different socio-ecological correlates and the meeting of these guidelines. This was a cross-sectional study with data from the Encuesta Nacional de Situación Nutricional (ENSIN-2015) in Colombia, 2015-2016. The sample comprised 3002 low-income preschoolers (3-4 years old, 50.7% boys). Data on physical activity, screen time, and sleep time were collected using the Cuestionario para la Medición de Actividad Física y Comportamiento Sedentario, reported by their parents. In total, 18 potential correlates (individual, interpersonal, organizational, and community level) were analyzed. Backward binary logistic regression analysis was performed with the potential correlates as independent variables and meeting all three 24-h movement guidelines as dependent variables. The prevalence of preschoolers meeting all three 24-h movement guidelines or none was 4.8% and 16.6%, respectively. In the final model, boys (odds ratio [OR] = 1.87, 95% confidence interval [CI] 1.00-3.50) and those who do not have television in their bedroom (OR = 2.09, 95%CI 1.05-4.14) were more likely to meet all three 24-h movement guidelines compared to with girls and those who have television, respectively. In conclusion, strategies to promote adherence to all 24-h movement guidelines among low-income preschoolers are warranted, and should focus on actions considering the importance of sex and home environment changes to support these movement behaviors.

Metabolic responses to acute sprint interval exercise training performed after an oral 75-gram glucose load in individuals with overweight/obesity.

There is evidence supporting that acute sprint interval training (SIT) might improve metabolic responses to postprandial glucose, but results are inconclusive. The aim of the present study was to explore the effects of acute SIT on metabolic response and substrate utilization in individuals with overweight/obesity after an oral 75-gram glucose challenge. Thirty-three participants with overweight/ obesity (32.7 ± 8.3 years, 24 male, 9 female) participated in the study and a crossover design was followed. After the 75-gram glucose load, participants were randomly allocated to two groups: no exercise (resting) or SIT protocol. Metabolic data including respiratory quotient (RQ) and substrate utilization rates (fats and carbohydrates) were collected using the COSMED Q-NRG + ® calorimeter. The RQ was significantly lower in the acute SIT group (0.76 [0.01]; p < 0.0001) than in the resting group (0.80 [0.01]; p = 0.036) at the 120-min postprandial time point, and the RQ area under the curve (AUC) was also lower in the SIT group (mean difference of -6.62, 95% CI -12.00 to -1.24; p = 0.0161). The contribution of fat to energy expenditure increased after SIT during the postprandial period whereas the contribution of carbohydrates decreased. The AUC for fat contribution was significantly higher (mean difference 2311.9, 95% confidence interval [CI] 578.8 to 4043.3; p = 0.0098) and the AUC for carbohydrate contribution was significantly lower (mean difference -2283.1, 95% CI -4040.2 to -527.1; p = 0.0117) in the SIT group than in the resting group. In conclusions, acute SIT might have a positive effect on metabolic responses to postprandial glucose and, accordingly, should be recommended for improving metabolism in people with overweight/obesity.

[Association between physical fitness and depressive symptoms in university students: a cross-sectional analysis]. / Relación entre la condición física y síntomas depresivos en universitarios: un análisis transversal.

Introduction: Objective: physical fitness is one of the most relevant predictors of an individual's mental health status. However, few studies have described the relationship between physical fitness and depressive symptoms in students from Latin America. The aim of this study was to verify the association between physical fitness and self-reporting of depressive symptoms among university students. Research methods and procedures: a cross-sectional study was conducted in 344 undergraduate students (53 % women, with a median age of 20 years, ranging from 18 to 23 years), from four public and private universities in Cali, Colombia. The components of physical fitness (vertical jump, arm pushups, trunk pushups and aerobic fitness) were assessed by field tests and a global fitness z-score was calculated as the mean of the z-scores values of each fitness test. In addition, global fitness z-score was divided into tertiles (T) to obtain three balanced groups: (T1) low, (T2) medium, and (T3) high global fitness z-score. Results: twelve percent of the population suffer from mild depressive symptoms, while 10 % reported moderate/severe depression, with women showing the highest score on the Beck-II Depression inventory. In men, inverse and statistically significant correlations were observed between the depression score of the Beck-II Depression inventory and lower muscle strength-vertical jump (Z-score) r = -0.190, aerobic fitness (Z-score) r = -0,195, and global fitness z-score r = -0.189; p < 0,01. The similar findings were observed after adjusting for age, smoking, alcohol intake and physical activity levels as covariable, between (T 1) and (T3) global fitness z-score, p = 0.028 in men. Conclusion: our results indicated that lower muscle strength and global fitness z-score was inversely related to self-rate depression symptoms using the Beck II depression inventory in men group.

Introducción: Objetivo: la condición física es uno de los factores predictores más relevantes del estado de salud mental de un individuo. No obstante, son pocos los estudios que han descrito la relación entre la condición física con síntomas depresivos en universitarios latinos. El objetivo del presente estudio fue verificar la posible relación entre la condición física y los síntomas depresivos en un colectivo de estudiantes universitarios. Métodos y procedimientos de investigación: estudio transversal en 344 universitarios (53 % mujeres) entre los 18 y 25 años (rango 18-23 años), pertenecientes a cuatro instituciones de educación superior de Cali, Colombia. Los síntomas depresivos se recogieron por autoinforme a través del inventario de Depresión Beck-II. Los componentes de la condición física (salto alto, flexiones de brazo, flexiones de tronco y condición aeróbica) se midieron a través de pruebas de campo. El promedio de las 4 variables de condición física se tipifico y transformaron como Z-score para establecer una única variable denominada índice general de condición física. Posteriormente se categorizó en tertiles (T), siendo el tertil (T3) la posición con mejor desempeño físico. Resultados: un 12 % de la población presentó síntomas depresivos leves, mientras que un 10 % presentaron depresión moderada/grave, siendo las mujeres las que acusaron mayor puntaje en el inventario de Depresión Beck-II. En el grupo de hombres, correlaciones inversas y estadísticamente significativas fueron observadas entre los valores de depresión con la escala Beck-II, con el componente de salto alto (Z-score) r = -0,190, la condición aeróbica (Z-score) r = -0,195, y con el índice general de condición física (Z-score) r = -0,189; p < 0,01. Esta misma relación, fue observada tras ajustar por la edad, tabaquismo, enolismo y actividad física semanal como covariable, en los hombres entre los terciles 1 y 3 (p = 0,028). Conclusión: los resultados obtenidos en el presente trabajo revelan que el salto alto y el índice general de condición física de los hombres se relacionan de manera inversa y significativa con el puntaje del inventario de Depresión de Beck-II.

Relación entre la condición física y síntomas depresivos en universitarios: un análisis transversal / Association between physical fitness and depressive symptoms in University students: a cross-sectional analysis

Objetivo: la condición física es uno de los factores predictores más relevantes del estado de salud mental de un individuo. No obstante, son pocos los estudios que han descrito la relación entre la condición física con síntomas depresivos en universitarios latinos. El objetivo del presente estudio fue verificar la posible relación entre la condición física y los síntomas depresivos en un colectivo de estudiantes universitarios. Métodos y procedimientos de investigación: estudio transversal en 344 universitarios (53 % mujeres) entre los 18 y 25 años (rango 18-23 años), pertenecientes a cuatro instituciones de educación superior de Cali, Colombia. Los síntomas depresivos se recogieron por autoinforme a través del inventario de Depresión Beck-II. Los componentes de la condición física (salto alto, flexiones de brazo, flexiones de tronco y condición aeróbica) se midieron a través de pruebas de campo. El promedio de las 4 variables de condición física se tipifico y transformaron como Z-score para establecer una única variable denominada índice general de condición física. Posteriormente se categorizó en tertiles (T), siendo el tertil (T3) la posición con mejor desempeño físico. Resultados: un 12 % de la población presentó síntomas depresivos leves, mientras que un 10 % presentaron depresión moderada/grave, siendo las mujeres las que acusaron mayor puntaje en el inventario de Depresión Beck-II. En el grupo de hombres, correlaciones inversas y estadísticamente significativas fueron observadas entre los valores de depresión con la escala Beck-II, con el componente de salto alto (Z-score) r = -0,190, la condición aeróbica (Z-score) r = -0,195, y con el índice general de condición física (Z-score) r = -0,189; p < 0,01. Esta misma relación, fue observada tras ajustar por la edad, tabaquismo, enolismo y actividad física semanal como covariable, en los hombres entre los terciles 1 y 3 (p = 0,028). (AU)

Objective: physical fitness is one of the most relevant predictors of an individual's mental health status. However, few studies have described the relationship between physical fitness and depressive symptoms in students from Latin America. The aim of this study was to verify the association between physical fitness and self-reporting of depressive symptoms among University students. Research methods and procedures: a cross-sectional study was conducted in 344 undergraduate students (53 % women, with a median age of 20 years, ranging from 18 to 23 years), from four public and private universities in Cali, Colombia. The components of physical fitness (vertical jump, arm pushups, trunk pushups and aerobic fitness) were assessed by field tests and a global fitness z-score was calculated as the mean of the z-scores values of each fitness test. In addition, global fitness z-score was divided into tertiles (T) to obtain three balanced groups: (T1) low, (T2) medium, and (T3) high global fitness z-score. Results: twelve percent of the population suffer from mild depressive symptoms, while 10 % reported moderate/severe depression, with women showing the highest score on the Beck-II Depression inventory. In men, inverse and statistically significant correlations were observed between the depression score of the Beck-II Depression inventory and lower muscle strength-vertical jump (Z-score) r = -0.190, aerobic fitness (Z-score) r = -0,195, and global fitness z-score r = -0.189; p < 0,01. The similar findings were observed after adjusting for age, smoking, alcohol intake and physical activity levels as covariable, between (T 1) and (T3) global fitness z-score, p = 0.028 in men. (AU)

Youth Leisure-Time Sedentary Behavior Questionnaire (YLSBQ): Reliability and Validity in Colombian University Students.

Sedentary behavior (SB) is influenced by variations in social, cultural and economic contexts. This study assesses the test-retest reliability and validity of the Youth Leisure-time Sedentary Behavior Questionnaire (YLSBQ), a self-report tool that examines total and domain-specific SB in a cohort of young adults from Colombia. A cross-sectional validation study was conducted among 447 Colombian college students (52.8% men; mean (± standard deviation) age of 19.55 ± 2.54 years). To assess the reliability of the YLSBQ, Kappa statistics (k) were used. A confirmatory factor analysis (CFA) was conducted to determine validity. The Cronbach alpha for the 12 behaviors of the YLSBQ showed a good-to-excellent internal consistency (0.867, ranging from 0.715-0.935). Intraclass correlation coefficient (ICC) indicated that 10 items (83.0%) and two items (17.0%) showed excellent and good reliability, respectively. Furthermore, ICC between the total sedentary time was 0.926 (95% confidence interval [CI] = 0.912 - 0.939), which was interpreted as excellent. The goodness-of-fit tests provided evidence that overall, a four-factor solution was an adequate fit with the time scores. In conclusion, the YLSBQ could be considered a reliable, valid and usable tool for the assessment of SB in young adults in a Latin American country. We found that the psychometric properties of the questionnaire were similar to those of the original Spanish validation study.

Differences in the ratio of soil microbial biomass carbon (MBC) and soil organic carbon (SOC) at various altitudes of Hyperalic Alisol in the Amazon region of Ecuador.

Protecting soil fertility represents a fundamental effort of sustainable development. In this study we investigate how different altitudes affect soil microbial biomass carbon (MBC) and soil organic carbon (SOC), and their ratio, MBC/SOC in Hyperalic Alisol. MBC and SOC are well established and widely accepted microbial quotients in soil science. Our work hypothesis was that a decrease in MBC and SOC should be observed at higher altitudes. This initial assumption has been verified by our measurements, being attributed to the increase in MBC and SOC at low altitudes. Our approach should contribute to the better understanding of MBC and SOC distribution in soil and changes in MBC/SOC at various altitudes in the region.

Adherence to the Mediterranean Diet in College Students: Evaluation of Psychometric Properties of the KIDMED Questionnaire.

No prior studies have examined the reliability properties of the 16-item Mediterranean Diet Quality Index (KIDMED) questionnaire among young adults from a non-Mediterranean country. The objective of this study was to determine the psychometric properties in terms of the reliability and validity of the KIDMED questionnaire in young adults from Colombia. A cross-sectional validation study was conducted among 604 Colombian college students (47.51% men and 52.48% women; mean age of 21.60 ± 2.02 years). Kappa statistics were used to assess the reliability of the KIDMED questionnaire. A categorical principal components analysis was used to determine validity. Based on the KIDMED score, 58.4% of students had a good adherence to the Mediterranean diet (MedDiet). Good agreement in the general score of the questionnaire was observed (κ = 0.727, 95% confidence interval = 0.676 to 0.778, p < 0.001). A five-factor model was identified which explained almost 51.38% of the variability, showing the multidimensionality of the questionnaire. In conclusion, this study provides reasonable evidence for the reliability and validity of the KIDMED questionnaire for assessing adherence to MedDiet in college students within a Latin American country. The evaluation of the psychometric properties of this tool in early adulthood and in a non-Mediterranean country will be useful in clinical practice and epidemiological research, since practitioners and health researchers now have a valid and reliable short scale.

Superstructure control of first-cycle voltage hysteresis in oxygen-redox cathodes.

In conventional intercalation cathodes, alkali metal ions can move in and out of a layered material with the charge being compensated for by reversible reduction and oxidation of the transition metal ions. If the cathode material used in a lithium-ion or sodium-ion battery is alkali-rich, this can increase the battery's energy density by storing charge on the oxide and the transition metal ions, rather than on the transition metal alone1-10. There is a high voltage associated with oxidation of O2- during the first charge, but this is not recovered on discharge, resulting in reduced energy density11. Displacement of transition metal ions into the alkali metal layers has been proposed to explain the first-cycle voltage loss (hysteresis)9,12-16. By comparing two closely related intercalation cathodes, Na0.75[Li0.25Mn0.75]O2 and Na0.6[Li0.2Mn0.8]O2, here we show that the first-cycle voltage hysteresis is determined by the superstructure in the cathode, specifically the local ordering of lithium and transition metal ions in the transition metal layers. The honeycomb superstructure of Na0.75[Li0.25Mn0.75]O2, present in almost all oxygen-redox compounds, is lost on charging, driven in part by formation of molecular O2 inside the solid. The O2 molecules are cleaved on discharge, reforming O2-, but the manganese ions have migrated within the plane, changing the coordination around O2- and lowering the voltage on discharge. The ribbon superstructure in Na0.6[Li0.2Mn0.8]O2 inhibits manganese disorder and hence O2 formation, suppressing hysteresis and promoting stable electron holes on O2- that are revealed by X-ray absorption spectroscopy. The results show that voltage hysteresis can be avoided in oxygen-redox cathodes by forming materials with a ribbon superstructure in the transition metal layers that suppresses migration of the transition metal.

Biogenetic study of the emissions of species: Pinus radiata, Eucalyptus globulus Labill and Alnus acuminata in Riobamba canton, Ecuador.

Background: Air pollution is one of the biggest problems in the world, and it is generated by industrial production, vehicular flow and use of fossil fuels, leaving aside other important emission sources such as vegetation. The aim of this research is to quantify the emissions of natural volatile organic compounds produced by the forest species: Eucalyptus globulus L., Pinus radiata and Alnus acuminata in Riobamba, Ecuador. Methods: Identification of plant coverings in the years 2014 and 2017was performed using geographic information systems tools, complemented with the application of the Guenther model for the calculation of monoterpenes and other organic volatile compounds; thus, to analyze the relationship between meteorological variables and concentrations of volatile organic compounds and nitrogen dioxide per species. Results: Mathematical calculation of emissions in Riobamba showed that Eucalyptus globulus L. registered higher emissions in the years 2014-2017, followed by Pinus radiata and Alnus acuminata. These emissions are due to the vegetation cover covering each species. The analysis of volatile organic compounds in forest plantations in air is directly related to the emissions represented in the environment and correlated with the meteorological variables of temperature, global solar radiation and wind velocity. The proposed method manages to estimate concentrations of monoterpenes and volatile organic compounds for the two examined seasons, presenting the influence of the species introduced in this study such as Eucalyptus globulus L. and Pinus radiata, with a reduction in their emissions (less area found in the year 2017, with respect to 2014). However, the emission of Alnus acuminata can be quantified only in 2017, since in 2014 no records of this species were found. Conclusions: Volatile organic compound concentrations in the air are directly related to the emissions represented spatially and correlated with the meteorological variables of temperature, global solar radiation and wind velocity.

Oxygen redox chemistry without excess alkali-metal ions in Na2/3[Mg0.28Mn0.72]O2.

The search for improved energy-storage materials has revealed Li- and Na-rich intercalation compounds as promising high-capacity cathodes. They exhibit capacities in excess of what would be expected from alkali-ion removal/reinsertion and charge compensation by transition-metal (TM) ions. The additional capacity is provided through charge compensation by oxygen redox chemistry and some oxygen loss. It has been reported previously that oxygen redox occurs in O 2p orbitals that interact with alkali ions in the TM and alkali-ion layers (that is, oxygen redox occurs in compounds containing Li+-O(2p)-Li+ interactions). Na2/3[Mg0.28Mn0.72]O2 exhibits an excess capacity and here we show that this is caused by oxygen redox, even though Mg2+ resides in the TM layers rather than alkali-metal (AM) ions, which demonstrates that excess AM ions are not required to activate oxygen redox. We also show that, unlike the alkali-rich compounds, Na2/3[Mg0.28Mn0.72]O2 does not lose oxygen. The extraction of alkali ions from the alkali and TM layers in the alkali-rich compounds results in severely underbonded oxygen, which promotes oxygen loss, whereas Mg2+ remains in Na2/3[Mg0.28Mn0.72]O2, which stabilizes oxygen.

Criptococosis congénita en un neonato expuesto a VIH: presentación de un caso / Congenital cryptococcosis in a newborn exposed to HIV: A case report

La criptococosis puede afectar niños de todas las edades, especialmente aquellos inmunocomprometidos. Usualmente se adquiere a través de la inhalación de esporas del medio ambiente, aunque existen otras formas de transmisión. Describimos un caso de criptococosis congénita adquirido de una madre con síndrome de inmunodeficiencia adquirida (SIDA) y tratado en forma exitosa con combinación de antimicoticos.

Cryptococcosis may affect children of all ages, specially those who are inmunocompromised. It is usually acquired from the inhalation of environmental spores, although other sources of transmission exist. We describe a case of congenital cryptococcosis transmitted from a mother with acquired immunodeficiency syndrome (AIDS), which was successfully treated with combination antifungal agents.

Electron-phonon coupling in hybrid lead halide perovskites.

Phonon scattering limits charge-carrier mobilities and governs emission line broadening in hybrid metal halide perovskites. Establishing how charge carriers interact with phonons in these materials is therefore essential for the development of high-efficiency perovskite photovoltaics and low-cost lasers. Here we investigate the temperature dependence of emission line broadening in the four commonly studied formamidinium and methylammonium perovskites, HC(NH2)2PbI3, HC(NH2)2PbBr3, CH3NH3PbI3 and CH3NH3PbBr3, and discover that scattering from longitudinal optical phonons via the Fröhlich interaction is the dominant source of electron-phonon coupling near room temperature, with scattering off acoustic phonons negligible. We determine energies for the interacting longitudinal optical phonon modes to be 11.5 and 15.3 meV, and Fröhlich coupling constants of ∼40 and 60 meV for the lead iodide and bromide perovskites, respectively. Our findings correlate well with first-principles calculations based on many-body perturbation theory, which underlines the suitability of an electronic band-structure picture for describing charge carriers in hybrid perovskites.

Tiempo de crecimiento bacteriano en hemocultivos en neonatos / Time bacterial growth in blood cultures in neonates Abstract

Introducción: La sepsis es causa importante de morbimortalidad neonatal. Objetivos: Detectar el tiempo en que la curva de crecimiento bacteriano es evidenciada en la muestra de sangre inoculada en los hemocultivos y comparar estos tiempos de crecimiento bacteriano entre bacterias gramnegativas y grampositivas, entre los tipos de sepsis neonatal y determinar las bacterias más frecuentemente aisladas entre neonatos prematuros y de término. Pacientes y método: Estudio descriptivo de recién nacidos en riesgo de sepsis o con sospecha de sepsis por manifestaciones clínicas o de laboratorio, en que se evaluaron 114 hemocultivos positivos entre 1.932 hemocultivos tomados entre mayo de 2010 y mayo de 2014. Los datos se analizaron con Stata® 11.0. Resultados: El 5,9% de los hemocultivos tuvieron crecimiento bacteriano. La mediana y rango intercuartílico de tiempos de crecimiento bacteriano para gramnegativos fue 11 h (10-13 h), para grampositivos diferentes a Staphylococcus coagulasa negativo (SCoN) 12 h (12-18 h) y para SCoN 42h (36-44h). El 95,8% de las bacterias grampositivas y el 96% de las gramnegativas tuvieron tiempos de crecimiento bacteriano ≤ 24 h de incubación, mientras que en los SCoN el 100% de los hemocultivos fue positivo en ≤ 62 h de incubación. Conclusión: El 100% de sepsis por bacterias gramnegativas, grampositivas no SCoN y 90% de las ocasionadas por SCoN, son identificadas en los hemocultivos en las primeras 48 h, por lo cual podemos concluir que para descartar una sepsis, un período de incubación en hemocultivos de 48 h es suficiente.

Introduction: Sepsis is a major cause of neonatal morbidity and mortality. Objectives: To detect the time when the bacterial growth curve is evidenced in the blood sample inoculated blood cultures and comparing the times of bacterial growth between Gram negative and Gram positive bacteria, among the types of neonatal sepsis and identifying microorganisms more often isolated from preterm and term. Patients and method: A descriptive study. 114 positive blood cultures from 1,932 blood cultures taken from 01-May-2010 and 31-May-2014 were evaluated. Data were analyzed with Stata® 11.0. Results: 5.9% of blood cultures had bacterial growth. The median and interquartile range of Gram negative times of bacterial growth was 11 h (10-13 h), for Gram positive coagulase-negative Staphylococcus different (CoNS) 12h (12-18h) and CoNS 42h (36-44h). 95.8% of Gram positive and 96% of Gram negative, were the times of bacterial growth ≤ 24 h incubation, whereas the 100% CoNS was positive ≤ 62 h of incubation. Conclusion: 100% of sepsis by Gram negative and Gram positive no CoNS and 90% of those caused by CoNS are identified in blood cultures in 48 h, so we can conclude that to rule out sepsis, an incubation period of 48 h in blood cultures is sufficient.

[Time bacterial growth in blood cultures in neonates]. / Tiempo de crecimiento bacteriano en hemocultivos en neonatos.

INTRODUCTION: Sepsis is a major cause of neonatal morbidity and mortality. OBJECTIVES: To detect the time when the bacterial growth curve is evidenced in the blood sample inoculated blood cultures and comparing the times of bacterial growth between Gram negative and Gram positive bacteria, among the types of neonatal sepsis and identifying microorganisms more often isolated from preterm and term. PATIENTS AND METHOD: A descriptive study. 114 positive blood cultures from 1,932 blood cultures taken from 01-May-2010 and 31-May-2014 were evaluated. Data were analyzed with Stata(®) 11.0. RESULTS: 5.9% of blood cultures had bacterial growth. The median and interquartile range of Gram negative times of bacterial growth was 11h (10-13h), for Gram positive coagulase-negative Staphylococcus different (CoNS) 12h (12-18h) and CoNS 42h (36-44h). 95.8% of Gram positive and 96% of Gram negative, were the times of bacterial growth≤24h incubation, whereas the 100% CoNS was positive≤62h of incubation. CONCLUSION: 100% of sepsis by Gram negative and Gram positive no CoNS and 90% of those caused by CoNS are identified in blood cultures in 48h, so we can conclude that to rule out sepsis, an incubation period of 48h in blood cultures is sufficient.

TiO2 anatase with a bandgap in the visible region.

TiO2 anatase plays a central role in energy and environmental research. A major bottleneck toward developing artificial photosynthesis with TiO2 is that it only absorbs ultraviolet light, owing to its large bandgap of 3.2 eV. If one could reduce the bandgap of anatase to the visible region, TiO2-based photocatalysis could become a competitive clean energy source. Here, using scanning tunneling microscopy and spectroscopy in conjunction with density functional theory calculations, we report the discovery of a highly reactive titanium-terminated anatase surface with a reduced bandgap of less than 2 eV, stretching into the red portion of the solar spectrum. By tuning the surface preparation conditions, we can reversibly switch between the standard anatase surface and the newly discovered low bandgap surface phase. The identification of a TiO2 anatase surface phase with a bandgap in the visible and high chemical reactivity has important implications for solar energy conversion, photocatalysis, and artificial photosynthesis.

Caracterización fenotípica y genotípica de Salmonella Typhimurium variante 5- asociada a un brote de enfermedad transmitida por alimentos en el municipio de Paz de Río, Boyacá, 2010 / Phenotypic and genotypic characterization of Salmonella Typhimurium variant 5- isolates associated with an outbreak of food-borne disease in Paz de Rio, Boyacá, Colombia, in 2010

Introducción: Salmonella enterica serotipo Typhimurium variante 5- es un patógeno muy relacionado con animales, especialmente con palomas, y asociado en pocos casos con infecciones esporádicas en humanos. Sin embargo, los sistemas de vigilancia epidemiológica han permitido detectarla en brotes en humanos. Objetivo: caracterizar por técnicas fenotípicas y genotípicas los aislamientos de Salmonella Typhimurium variante 5- asociados a un brote de enfermedad transmitida por alimentos (ETA) en el municipio de Paz de Río, Boyacá, en el 2010. Materiales y métodos: doce aislamientos de Salmonella spp., fueron remitidos para confirmación bioquímica, identificación del serotipo y perfil de susceptibilidad antimicrobiana. Se analizaron genotípicamente por electroforesis en gel de campo pulsado (PFGE) con las enzimas Xbal y Blnl. Resultados: todos los aislamientos se confirmaron como Salmonella spp., y presentaron resistencia a tetraciclina y estreptomicina y sensibilidad a los demás antibióticos ensayados; 11/12 se identificaron como Salmonella Typhimurium variante 5- y mostraron en la PFGE el patrón COIN10.JPX.X01.0168 con la enzima XbaI y dos aislamientos de este mismo grupo se confirmaron con la enzima BlnI obteniendo el patrón de PFGE COIN10.JPX.A26.0002. El aislamiento restante se identificó como Salmonella Typhimurium con patrón de PFGE con la enzima Xbal COIN10.JPX.X01.0221. Conclusión: se reporta por primera vez en Colombia un brote de ETA asociado epidemiológicamente con aislamientos de Salmonella Typhimurium variante 5- que estuvieron relacionados fenotípica y genéticamente.

Introduction: Salmonella enterica serotype Typhimurium variant 5- is a pathogen closely related to animals, especially pigeons, which has been also associated in rare cases with sporadic infections in humans. However, epidemiological surveillance systems have enabled the detection of this variant in human outbreaks. Objective: To characterize by means of phenotypic and genotypic techniques the isolates of Salmonella Typhimurium variant 5- associated with an outbreak of food-borne disease in Paz de Rio, Boyacá, Colombia (2010), in order to establish their molecular relationships. Materials and methods: Twelve isolates of Salmonella spp., were analyzed by biochemical, serotyping and antimicrobial susceptibility tests. Pulsed-field gel electrophoresis (PFGE) with XbaI and Blnl enzymes was used to establish their molecular relationships. Results: All isolates were confirmed as Salmonella spp. They were resistant to tetracycline and streptomycin and sensitive to the rest of antibiotics tested. Eleven isolates were identified as Salmonella Typhimurium variant 5- and grouped in COIN10.JPX.X01.0168 pattern using the enzyme XbaI; two isolates in this group were confirmed using the enzyme BlnI with the COIN10. JPX.A26.0002 pattern. One isolate was identified as Salmonella Typhimurium with COIN10.JPX.X01.0221 pattern with the enzyme XbaI. Conclusion: This is the first outbreak in Colombia of foodborne illness epidemiologically associated with isolates of Salmonella Typhimurium variant 5 -, which were phenotypically and genetically related.

Parenteral solution of nutritional hepatotrophic factors improves regeneration in thioacetamide-induced cirrhotic livers after partial hepatectomy.

Liver resection is a suitable option for the treatment of certain hepatic conditions, particularly hepatocarcinomas, in patients with cirrhosis. However, this disease impairs liver regeneration, which increases the risk of liver failure and postoperative death. Supportive treatments for regeneration of the remaining liver may be useful for the recovery of these patients. We demonstrated that nutritional hepatotrophic factors (NHF) is an effective regenerative stimulus for cirrhotic livers in rats subjected to partial hepatectomy (PH). The rats with thioacetamide-induced cirrhosis were subjected to PH, and they were divided into 2 groups. One group received intraperitoneal administration of NHF, and the other group received saline solution. After 12 days, biometric data, collagen content, hepatocyte regeneration (proliferation cell nuclear antigen immunochemistry), and profibrotic gene expression (Collagen-α1, matrix metalloproteinase 2, tissue inhibitor of metalloproteinase 1, and transforming growth factor beta 1) were assessed. The results indicated that the rats treated with NHF after PH had an increased liver size, a reduced amount of collagen, and a higher hepatocyte proliferation index compared with the rats that underwent PH alone. In addition, collagen-α1 gene expression was decreased in the NHF-treated rats. Thus, postoperative improvement in the liver morphology following NHF treatment may cause a significant decrease in the risk of liver failure and mortality after hepatic resection.

Enhanced novelty-induced corticosterone spike and upregulated serotonin 5-HT1A and cannabinoid CB1 receptors in adolescent BTBR mice.

Hypothalamic pituitary adrenal (HPA) axis responses to change and social challenges during adolescence can influence mental health and behavior into adulthood. To examine how HPA tone in adolescence may contribute to psychopathology, we challenged male adolescent (5 weeks) and adult (16 weeks) BTBR T(+)tf/J (BTBR) and 129S1/SvImJ (129S) mice with novelty in sociability tests. In prior studies these strains had exaggerated or altered HPA stress responses and low sociability relative to C57BL/6J mice in adulthood. In adolescence these strains already exhibited similar or worse sociability deficits than adults or age-matched C57 mice. Yet BTBR adolescents were less hyperactive and buried fewer marbles than adults. Novelty-induced corticosterone (CORT) spikes in adolescent BTBR were double adult levels, and higher than 129S or C57 mice at either age. Due to their established role in HPA feedback, we hypothesized that hippocampal Gαi/o-coupled serotonin 5-HT1A and cannabinoid CB1 receptor function might be upregulated in BTBR mice. Adolescent BTBR mice had higher hippocampal 5-HT1A density as measured by [(3)H] 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) binding than C57 mice, and adult BTBR 8-OH-DPAT-stimulated GTPγS binding was higher than in either C57 or 129S mice in this region. Further, BTBR hippocampal CB1 density measured by [(3)H]CP55,940 binding was 15-20% higher than in C57. CP55,940-stimulated GTPγS binding in adult BTBR dentate gyrus was 30% higher then 129S (p<0.05), but was not a product of greater neuronal or cell density defined by NeuN and DAPI staining. Hence hyperactive HPA responsiveness during adolescence may underlie 5-HT1A and CB1 receptor up-regulation and behavioral phenotype of BTBR mice.