Plasmonic and Photothermal Effects of CuS Nanoparticles Biosynthesized from Acid Mine Drainage with Potential Drug Delivery Applications.

In this work, the plasmonic and photothermal effects of CuS nanoparticles biosynthesized from acid mine drainage (AMD) were studied. CuS were formed by delivering the H2S generated by a sulfidogenic bioreactor to an off-line system containing the AMD. The precipitates collected after contact for an hour were washed and physico-chemically characterized, showing a nanoparticle with a mean diameter of 33 nm, crystalline nature and semiconductor behavior with a direct band gap of 2.2 eV. Moreover, the CuS nanoparticles exhibited localized surface plasmonic resonance in the near infrared range, with a high absorption band centered at 973 nm of wavelength, which allowed an increase in the temperature of the surrounding media under irradiation. Finally, the cytotoxicity of the CuS nanoparticles as well as their potential use as part of drug delivery platforms were investigated.

Residence Times from Molecular Dynamics Simulations.

In this work, efficient methods are proposed for the calculation, from molecular dynamics trajectories, of residence times (RTs) and related quantities. One of these was designed to obtain RT distributions, from which mean residence times (MRTs), residual time distributions, and mean residual times can be computed. This method does not require the assumptions and approximations made by the most commonly used methods. Its link to the most popular method in the literature is identified. It is shown how the much faster new method can be used as a replacement for the latter and the advantages of doing so. Also, a prescription for estimating the uncertainty in the MRTs obtained though the proposed method is provided. Another even faster method for the calculation of the MRTs, their uncertainties, and the mean residual times is also proposed. It yields exactly the same results as the first one but does not allow to obtain the mentioned distributions. Another very popular method, based on autocorrelation functions, for computing MRTs is analyzed in terms of its assumptions and approximations. An alternative, also based on autocorrelation functions, which is faster and requires fewer assumptions is presented. A prescription for the calculation of the uncertainty of the MRTs obtained with the latter method is also provided. In the literature, there are a few methods to discard short transient escapes. Here, an algorithm is suggested that is much faster than the most used one and allows a more integral treatment of the process. Also, it is more widely applicable because it is a preprocessing step that can be used in conjunction with any of the proposed methods mentioned above. The main disadvantage of these two approaches to discard brief escapes is that the maximum duration allowed for an escape to be considered transient appears as a parameter to be determined for the particular system under study. As an alternative, a parameter-free method of a similar character is also proposed to estimate the mean residence time of particles that reached a constant probability of leaving the region of interest.

Effect of High Altitude on the Survival of COVID-19 Patients in Intensive Care Unit: A Cohort Study.

Purpose: The effect of high altitude ( ≥ 1500 m) and its potential association with mortality by COVID-19 remains controversial. We assessed the effect of high altitude on the survival/discharge of COVID-19 patients requiring intensive care unit (ICU) admission for mechanical ventilation compared to individuals treated at sea level. Methods: A retrospective cohort multi-center study of consecutive adults patients with a positive RT-PCR test for COVID-19 who were mechanically ventilated between March and November 2020. Data were collected from two sea-level hospitals and four high-altitude hospitals in Ecuador. The primary outcome was ICU and hospital survival/discharge. Survival analysis was conducted using semi-parametric Cox proportional hazards models. Results: Of the study population (n = 670), 35.2% were female with a mean age of 58.3 ± 12.6 years. On admission, high-altitude patients were more likely to be younger (57.2 vs. 60.5 years old), presented with less comorbidities such as hypertension (25.9% vs. 54.9% with p-value <.001) and diabetes mellitus (20.5% vs. 37.2% with p-value <.001), less probability of having a capillary refill time > 3 sec (13.7% vs. 30.1%, p-value <.001), and less severity-of-illness condition (APACHE II score, 17.5 ± 8.1 vs. 20 ± 8.2, p < .01). After adjusting for key confounders high altitude is associated with significant higher probabilities of ICU survival/discharge (HR: 1.74 [95% CI: 1.46-2.08]) and hospital survival/discharge (HR: 1.35 [95% CI: 1.18-1.55]) than patients treated at sea level. Conclusions: Patients treated at high altitude at any time point during the study period were 74% more likely to experience ICU survival/discharge and 35% more likely to experience hospital survival/discharge than to the sea-level group. Possible reasons for these findings are genetic and physiological adaptations due to exposure to chronic hypoxia.

Calculation of the inner-shell contribution to the correlation energy through DLPNO-CEPA/1 and scaled same-spin second-order Møller-Plesset perturbation theory.

The use of two low-cost methods for the prediction of the inner-shells contribution to the correlation energy is analyzed. The Spin-Component-Scaled second-order Møller-Plesset perturbation theory (SCS-MP2) was reparameterized for the prediction of such contributions. The best results are found when only the same spin term is considered (SSS-MP2). The Coupled Electron Pair Approximation (CEPA) using the Domain-based Local Pair Natural Orbital approximation (DLPNO) was also studied for the same purpose. The methods were tested for atomization energies on the W4-11 test set using basis sets up to quadruple zeta quality. The SSS-MP2 proved to be a marked improvement upon MP2 decreasing the root-mean-square-error (RMSE) from 0.443 to 0.302 kcal mol-1 . The RMSE of DLPNO-CEPA/1 in the test set is only 0.147 kcal mol-1 and its computational cost is very low considering the intended applications. Furthermore, a linear combination of both methods decreased the RMSE to 0.118 kcal mol-1 .

Revisiting the thermochemistry of chlorine fluorides.

In this work, accurate calculations of standard enthalpies of formation of chlorine fluorides (ClFn, n = 1-7; Cl2 F and Cl3 F2 ) were performed through the isodesmic reactions scheme. It is argued that, for many chlorine fluorides, the gold standard method of quantum chemistry (CCSD(T)) is not capable to predict enthalpy values nearing chemical accuracy if atomization scheme is used. This is underpinned by a thorough analysis of total atomization energy results and the inspection of multireference features of these compounds. Other thermodynamic quantities were also calculated at different temperatures. To complement the energetic description, elimination curves were studied through density functional theory as a computationally affordable alternative to highly correlated wave function-based methods. © 2017 Wiley Periodicals, Inc.

Causas de reintervenciones quirúrgicas por complicación postoperatoria en pacientes de una unidad de cuidados intensivos quirúrgicos sometidos a cirugía abdominal / Causes of reoperations in postoperative complications after abdominal surgery in a surgical intensive care unit

Objetivos: Describir las causas de las reintervenciones luego de una cirugía abdominal en pacientes de una unidad de cuidados intensivos quirúrgicos de un hospital general. Material y métodos: Estudio prospectivo, tipo reporte de casos. Se incluyeron a los pacientes postoperados de cirugía abdominal, hospitalizados en la Unidad de Cuidados Intensivos Quirúrgicos del Hospital Nacional Cayetano Heredia y quienes requirieron de reintervención quirúrgica entre febrero de 2009 y enero de 2010 por una complicación postoperatoria. Resultados: El hallazgo más frecuente fue la perforación en 31,6%, seguido de absceso abdominal 21,1% y dehiscencias 21,1%. Conclusiones: Las perforaciones fueron los hallazgos más frecuentes, siendo su frecuencia mayor a lo reportado en la literatura. La incidencia de reintervención fue de 15%.

Objectives: To describe the causes of reoperations after abdominal surgery patients in the Surgical Intensive Care Unit of a general hospital. Methods: Prospective case reports study. We included postoperated patients of abdominal surgery, hospitalized in the Surgical Intensive Care Unit of the Hospital Nacional Cayetano Heredia, who required surgical reintervention between February 2009 and January 2010 for a postoperative complication. We reviewed medical records. Results: The most common findings were perforation 31.6%, abdominal abscess 21.1%, and dehiscences 21.1%. Conclusions: The perforations were the most frequent finding, with frequency higher than that reported in the literature. The incidence of reoperation was 15%.

Características de osificación de la mano y las vértebras cervicales y correlación entre las dos técnicas como indicadores de maduración somáticaen niños(as) entre 8 a 17 años / Ossification characteristics of the hand and the cervical vertebrae and correlation between the two techniques as indicators of somatic maturation in children from 8 to 17 years

Objective: To determine the characteristics of hand-wrist and cervical vertebral ossification and establish the correlation between these two techniques as indicators of somatic maturation in children between 8 and 17 years old. Materials and Methods: A cross sectional and correlational study was carried out in 200 children between 8 and 17 years old, born in the same city. Children should show no systemic diseases that affect the skeletal development or craniofacial syndromes. Lateral cephalometric radiographs and carpogram test were taken in the same day. The frequency of the variables such as gender, carpal and cervical vertebrae maturation indexes was established. A correlation matrix (Pearson's coefficient) for the quantitative variables (height and weight) and the variables that explain the indexes, and the ordinal scale variables and Kendall's Tau-b statistics were done. Regression models were developed to predict the skeletal maturation index (SMI). Results: According to the age and level of skeletal maturation (skeletal maturation assessment - SMA), the ossification stages begin earlier in women than in men (women SMI 1: 8.4 +0.8 years and in men to 10.3 +1.5 years). Depending on the correlation model, there is a direct relation between height and shape of vertebrae with the SMI. The coefficient of determination (R2) indicated that 86% of SMI is explained by the two analyzed variables. Conclusions: There was a statistically significant correlation between height and shape of the vertebral body with stages of skeletal maturation index (SMI)...(AU)

Objetivo: Determinar las características de osificación de la mano y las vértebras cervicales y establecer la correlación entre las dos técnicas como indicadores de maduración somática en niños entre 8 y 17 años. Materiales y métodos: Este estudio correlacional - transversal, se realizó en 200 niños entre 8 y 17 años, que no presentaban enfermedades sistémicas que afectarán el desarrollo esqueletal, ni síndromes craneofaciales. Las radiografías cefálica de perfil y carpograma fueron tomadas el mismo día. El carpograma se evaluó de acuerdo con la edad y el nivel de maduración esqueletal (Skeletal maturation assesment ­ SMA). Se estableció la frecuencia para las variables género, índice de maduración carpal y de la columna vertebral. Se realizó una matriz de correlaciones (Coeficiente de Pearson) para las variables cuantitativas peso talla y las variables que explican los índices, y para las variables en escala ordinal, el estadístico Tau-b de Kendall. Se construyeron modelos de regresión con el objetivo de predecir el SMI. Resultados: los estadios de osificación se iniciaron más temprano en las mujeres que en los hombres (mujeres SMI. 1: 8,4+0,8 años y en los hombres a los 10,3+1,5 años). Según el modelo de correlación hubo una relación directa entre la altura y la forma de las vértebras con el SMI. El coeficiente de determinación (R2) indicó que el 86% del SMI se explicó por las dos variables estudiadas. Conclusiones: La maduración ósea establecida de acuerdo al índice de maduración esquelética de Fishman, se presentó cronologicamente más temprano. Hubo una correlación estadísticamente significativa entre la altura y la forma del cuerpo vertebral con los estadios de maduración esquelética (SMI)...(AU)

A dual platform for selective analyte enrichment and ionization in mass spectrometry using aptamer-conjugated graphene oxide.

This study demonstrates the use of aptamer-conjugated graphene oxide as an affinity extraction and detection platform for analytes from complex biological media. We have shown that cocaine and adenosine can be selectively enriched from plasma samples and that direct mass spectrometric readouts can be obtained without a matrix and with greatly improved signal-to-noise ratios. Aptamer-conjugated graphene oxide has clear advantages in target enrichment and in generating highly efficient ionization of target molecules for mass spectrometry. These results demonstrate the utility of the approach for analysis of small molecules in real biological samples.

Simultaneous nitrogen doping and reduction of graphene oxide.

We developed a simple chemical method to obtain bulk quantities of N-doped, reduced graphene oxide (GO) sheets through thermal annealing of GO in ammonia. X-ray photoelectron spectroscopy (XPS) study of GO sheets annealed at various reaction temperatures reveals that N-doping occurs at a temperature as low as 300 degrees C, while the highest doping level of approximately 5% N is achieved at 500 degrees C. N-doping is accompanied by the reduction of GO with decreases in oxygen levels from approximately 28% in as-made GO down to approximately 2% in 1100 degrees C NH(3) reacted GO. XPS analysis of the N binding configurations of doped GO finds pyridinic N in the doped samples, with increased quaternary N (N that replaced the carbon atoms in the graphene plane) in GO annealed at higher temperatures (> or = 900 degrees C). Oxygen groups in GO were found responsible for reactions with NH(3) and C-N bond formation. Prereduced GO with fewer oxygen groups by thermal annealing in H(2) exhibits greatly reduced reactivity with NH(3) and a lower N-doping level. Electrical measurements of individual GO sheet devices demonstrate that GO annealed in NH(3) exhibits higher conductivity than those annealed in H(2), suggesting more effective reduction of GO by annealing in NH(3) than in H(2), consistent with XPS data. The N-doped reduced GO shows clearly n-type electron doping behavior with the Dirac point (DP) at negative gate voltages in three terminal devices. Our method could lead to the synthesis of bulk amounts of N-doped, reduced GO sheets useful for various practical applications.

Dejar de fumar: factor protector de cáncer gástrico / Quit smoking: protection factor to gastric cancer / Deixar de fumar: fator protetor de câncer gástrico

El cáncer gástrico (CG) es una de las mayores causas de muerte en la población colombiana. Su incidencia es variable y se han identificado zonas de alto riesgo, entre ellas el departamento de Caldas y en especial Manizales. En esta patología de etiología compleja se hallan comprometidos factores externos e internos. Entre los externos están las exposiciones ocupacionales y/o ambientales a compuestos carcinogénicos o procarcinógenos. Uno de ellos es el humo del cigarrillo y por ello se exploró su posible asociación con el riesgo a CG. Se estudiaron los casos nuevos de CG que se presentaron durante 18 meses en el Hospital de Caldas. De ellos, 65 reunieron los criterios de inclusión y se aparearon con 65 controles. Se colectó la información haciendo énfasis en el tabaquismo. Se evidenció asociación significativa entre el hábito de fumar y el riesgo a CG (OR=2,1, p=0,035). También se halló asociación significativa entre el CG y los estratos socioeconómicos medio y bajo (p=0,000). En conclusión, estos resultados sugieren que dejar de fumar protege del riesgo a desarrollar CG; aunque también existen otros factores de riesgo endógenos y exógenos que inciden en la presentación de este tipo de cáncer que no fueron explorados en este estudio.

Gastric cancer (GC) is one of the major causes of death in the Colombian population. Its incidence is variable and high risk zones have been identified, among them the department of Caldas, and especially Manizales. In this pathology of complex etiology external and internal factors are found. Among the external factors are the occupational and/or environmental exhibitions to carcinogenic or procarcinogens compounds. One of them is cigarette smoke, and therefore its possible association with GC risk was explored. The new cases of GC that arose in 18 months in the Hospital de Caldas were studied. From these, 65 met the inclusion criteria and were matched with 65 controls. The information was collected emphasizing the smoking activity. Significant association was demonstrated between the smoking habit and the risk to GC (OR=2,1, p=0,035). Also significant association was found between GC and the middle and low socioeconomic stratum (p=0,000). In conclusion, these results suggest that quitting smoking is a protector factor to the risk of developing GC; although there are other endogenous and exogenous risk factors that impact the presence of this type of cancer that were not explored in this study.

O câncer gástrico é uma das maiores causas da morte na povoação colombiana. Sua incidência é variável e tem identificado zonas de alto risco, entre elas o estado de Caldas e em especial Manizales. Em está patologia de etimologia complexa encontram-se comprometidos fatores externos e internos. Entre os externos estão as exposições ocupacionais e/ou ambientais a compostos carcinogênicos ou procarcinogenos. Uno de eles é o fumo do charuto e por esta razão exploro-se a sua possível associação com o risco a CG. Estudaram se os casos novos de CG que presentearam se durante 18 mêses no hospital de Caldas. De eles, 65 reuniram os critérios de inclusão e emparelhou-se com 65 controles. Coleto-se a informação fazendo ênfase em tabagismo. Evidencia-se a associação significativa entre o hábito de fumar e o risco a CG (OR=2,1,0.035). Também encontrarem-se uma associação significativa entre o CG e os estratos socioeconômicos médios baixos (p=0.000). Em conclusão, estes resultados sugerem que deixar de fumar protege do risco a desenvolver CG; porém também existem outros fatores de risco endógeno e exógeno que incidem na apresentação deste tipo de câncer que no foram explorados neste estúdio

[Dental fluorosis in primary school students of the department of Caldas, Colombia]. / Fluorosis dental en escolares del departamento de Caldas, Colombia.

BACKGROUND: A prevalence survey of dental fluorosis was conducted among primary school students in Caldas, a small province in west central Colombia. MATERIALS AND METHODS: The cross-sectional study compared the prevalence of dental fluorosis in the four regions of Caldas. In the urban area, a probabilistic sample was selected and,in the rural areas, students were sampled in locations that were readily accessible. One thousand sixty-one students were examined while at school in daylight conditions. The surveillance tool applied was the Dean Index. Univariate and bivariate analyses were made with a chi-square test being applied for the latter to show independence among variables. RESULTS: Sixty-three percent (95% CI: 60-66%) of primary school students were affected by fluorosis to some degree of severity. Among them, 56% (95% CI: 52-59) were classified in the mild and very mild degrees, whereas 7% (95% CI: 2-16) were classified as moderate or severe. A statistically significant association between the region variable and dental fluorosis was observed. However, no association was found with gender, area, schooling or age variables. Within Caldas, the eastern region showed the lowest prevalence (47.9%) in contrast to the other three areas (northern, central-south and western) where prevalences exceeded 68%. CONCLUSIONS: At least two of three primary school students in Caldas suffer from some degree of dental fluorosis.

Fluorosis dental en escolares del departamento de Caldas, Colombia / Dental fluorosis in primary school students of the department of Caldas, Colombia

Objetivo. Determinar la prevalencia de fluorosis dental en los escolares del departamento de Caldas en el 2002.Materiales y métodos. Se realizó un estudio de corte transversal en escolares de las cuatro regiones del departamento, para lo cual se seleccionó una muestra probabilística para el área urbana y por conveniencia para la rural. Se examinaron 1.061 escolares en las mismas instalaciones de los establecimientos educativos, en condiciones de luz natural y utilizando los criterios de Dean. Se llevó a cabo análisis univariado y bivariado; para el último se empleó c2 como prueba de independencia entre variables. Resultados. Se encontró que el 63,3 por ciento (IC95 por ciento: 60,0 a 66,1) de los escolares de Caldas estaba afectado por fluorosis dental en algún grado. El 56,3 por ciento(IC95 por ciento: 52 a 59) de los escolares se encontró en las categorías muy leve y leve, mientras el 7 por ciento(IC95 por ciento: 2 a 16) se hallaba en las categorías moderada y grave. Se observó asociación estadísticamente significativa de la variable región con fluorosis dental, pero no con las variables sexo, área, nivel de escolaridad y edad. La región Oriente mostró una menor prevalencia (47,9 por ciento) con relación a las otras tres áreas (Norte, Centro-Sur y Occidente) que presentaron prevalencias superiores al 68 por ciento. Conclusiones. La fluorosis dental se presenta en algún grado en dos de cada tres escolares

Moraxella catarrhalis en la infecciones respiratorias altas / Moraxella catarrhalis in upper respiratory infections

Durante 12 meses se estudian las infecciones otorrinolaringológicas en dos hospitales de Lima, tanto en niños como en adultos, con especial énfasis en Moraxella catarrhalis. Se tomaron 318 muetras de igual número de pacientes, de los cuales el 40 por ciento resultó negativo a bacterias patógenas. Del 60 por ciento restante se identificó "Staphylococcus aureus" como el causante del 31 por ciento de las infecciones, seguido de "Streptococcus pneumoniae" con el 19 por ciento, luego Moraxella Catarrhalis con 16 por ciento y en cuarto lugar Haemophilus influenzae con 10 por ciento. Rinorrea purulenta fue el principal síntoma en todos los casos. Streptococcus pneumoniae, moraxella catarrhalis y Haemophilus influenzae se aislaron mayoritariamente en niños menores de 14 años. El 15 por ciento de los A. aureus fueron oxacilino-resistentes, el 11 por ciento de S. pneumoniae fueron resistentes a la penicilina, el 70 por ciento de M. catarrhalis eran productoras de B-lactamasa y el 5 por ciento de H. influenzae también producian B-lactamasa. Nuestros resultados permiten orientar mejor el tratamiento antibiótico de la infecciones respiratorias altas.