PREPARACION Y CARACTERIZACIÓN DE ALGUNOS DERIVADOS DEL QUITOSANO

Some derivatives were prepared from chitosan extracted from shrimp shell with a molecular weight of 7.14 x 105 g / mol. The first of these derivatives was carboxymethylchitosan which was prepared by the addition of monochloroacetic acid to chitosan giving a product with molecular weight of 17.97 x 105 g / mol and degree of deacetylation 2.79%, which was characterized by Infrared Spectrumcopy with Transformed Fourier (FTIR). Chitosan was also acylated through a reaction with cinnamaldehyde obtaining N-Acyl-chitosan as a product, which was characterized by solubility tests and FTIR, with which the formation of the product was determined. Chitosan crosslinking with polyvinyl alcohol was performed and characterized by FTIR and its surface morphology using electron scanning electron microscopy (SEM). Additionally, biodegradability was determined as an eco-friendly alternative and as a manufacturing material. In these tests the loss of sample weight, thickness and diameter was taken into account, demonstrating that the sample of the chitosan crosslinked with polyvinyl alcohol degrades at a lower rate than the uncrosslinked sample.Se prepararon algunos derivados a partir de quitosano extraído de cascará de camarón con peso molecular de 7,14 x105 g/mol.  El primero de estos derivados fue el carboximetilquitosano que se preparó por adición de ácido monocloroacético al quitosano dando un producto con peso molecular de 17,97 x 105 g/mol y grado de desacetilación 2.79 %, el cual fue caracterizado por Espectrocopía Infrarrojo con Transformada de Fourier (FTIR).   También se aciló el quitosano a través de una reacción con cinamaldehído obteniéndose N-Acil-quitosano como producto, el cual se caracterizó por pruebas de solubilidad y FTIR, con la cual se determinó la formación del producto. Se realizó el entrecruzamiento de quitosano con alcohol polivinilico y se caracterizo por FTIR y por su morfología superficial usando microscopia electrónica de barrido de electrones (SEM).  Adicionalmente, se les determinó la biodegradabilidad  como una alternativa eco-amigable y como material de manufactura. En estas pruebas se tomó en cuenta la pérdida de peso de la muestra, espesor y diámetro demostrando que la muestra del quitosano entrecruzado con alcohol polivinílico se degrada a una velocidad  menor que la muestra sin entrecruzar. Por otro lado, también se prepararon hidrogeles por entrecruzamiento de quitosano y alcohol polivinílico seguido de entrecruzamiento con etilenglicol diglicil éter (Q-EDGE-PVA), los cuales fueron caracterizados por espectroscopia infrarrojo y por su morfología superficial usando microscopia electrónica de barrido de electrones (SEM).&nbsp

ACTIVIDAD ANTIBACTERIANA DE TERPENOS PRESENTES EN EXTRACTOS ELABORADOS A PARTIR DE HOJAS MADURAS DE MYROSPERMUM FRUTESCENS

The isolation of a triterpene and four diterpenes of the cassano type was performed from the fractionation of the AcOEt / CH3OH extract of mature leaves of Myrospermum frutescens. All the isolated compounds were evaluated to determine their antibacterial potential against Gram-positive and Gram-negative bacteria by the diffusion-disk antibiogram method. Among the compounds tested, it was observed that the compound 6β,13-dihidroxi-18-acetoxi-cassano-15,16-diene (4) showed higher activity against Staph. aureus with inhibition halos of 15, 16 and 17 mm for the loads of 25, 50 and 75 μg, respectively. The values ​​registered in relation to the sensitivity ranges for the Gentamicin control indicated that this bacterium shows sensitivity to this compound. Compounds Estigmasterol (1), 6β-hidroxi-18-acetoxycassano-13,15-diene (2), 6β,-18-dihidroxicassano-13,15-dieno (3), and 6β,18,17-trihidroxicassano-13,15-dieno (5), showed moderate activity, but lower compared to the positive controls used (Ampicillin and Gentamicin) in this trial.Se realizó el aislamiento e identificación de un triterpeno y cuatro diterpenos de tipo cassano a partir del fraccionamiento del extracto de AcOEt/CH3OH de hojas maduras de Myrospermum frutescens. Todos los compuestos aislados fueron evaluados para determinar su potencial antibacteriano frente a bacterias Gram-positivas y Gram-negativas mediante el método de antibiograma por disco difusión.  Entre los compuestos ensayados, se observó que el compuesto 6β,13-dihidroxi-18-acetoxi-cassano-15,16-dieno (4),  presentó mayor actividad contra Staph. aureus con halos de inhibición de 15, 16 y 17 mm para las cargas de 25, 50 y 75 µg, respectivamente. Los valores registrados en relación a los rangos de sensibilidad para el control Gentamicina indicaron que esta bacteria presenta sensibilidad a este compuesto. Los compuestos Estigmasterol (1), 6β-hidroxi-18-acetoxycassano-13,15-dieno (2), 6β,-18-dihidroxicassano-13,15-dieno (3), y 6β,18,17-trihidroxicassano-13,15-dieno (5), presentaron actividad moderada, pero más baja en comparación con los controles positivos utilizados (Ampicilina y Gentamicina) en este ensayo

Socioeconomic inequalities in low birth weight risk before and during the COVID-19 pandemic in Argentina: A cross-sectional study

Background: The coronavirus disease 2019 (COVID-19) pandemic may have exacerbated existing socioe- conomic inequalities in health. In Argentina, public hospitals serve the poorest uninsured segment of the population, while private hospitals serve patients with health insurance. This study aimed to assess whether socioeconomic inequalities in low birth weight (LBW) risk changed during the first wave of the COVID-19 pandemic. Methods: This multicenter cross-sectional study included 15929 infants. A difference-in-difference (DID) analysis of socioeconomic inequalities between public and private hospitals in LBW risk in a pandemic cohort (March 20 to July 19, 2020) was compared with a prepandemic cohort (March 20 to July 19, 2019) by using medical records obtained from ten hospitals. Infants were categorized by weight as LBW < 2500 g, very low birth weight (VLBW) < 1500 g and extremely low birth weight (ELBW) < 1000 g. Log binomial regression was performed to estimate risk differences with an interaction term representing the DID estimator. Covariate-adjusted models included potential perinatal confounders. Findings: Of the 8437 infants in the prepandemic cohort, 4887 (57 ? 9%) were born in public hospitals. The pandemic cohort comprised 7492 infants, 4402 (58 ? 7%) of whom were born in public hospitals. The DID estimators indicated no differences between public versus private hospitals for LBW risk ( −1 ? 8% [95% CI −3 ? 6, 0 ? 0]) and for ELBW risk ( −0 ? 1% [95% CI −0 ? 6, 0 ? 3]). Significant differences were found between public versus private hospitals in the DID estimators ( −1 ? 2% [95% CI, −2 ? 1, −0 ? 3]) for VLBW risk. The results were comparable in covariate-adjusted models. Interpretation: In this study, we found evidence of decreased disparities between public and private hos- pitals in VLBW risk. Our findings suggest that measures that prioritize social spending to protect the most vulnerable pregnant women during the pandemic contributed to better birth outcomes. Funding: No funding was secured for this study.Fil: Cuestas, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Gómez Flores, Martha E.. Gobierno de la Provincia de Buenos Aires. Hospital Doctor Ramón Carrillo; ArgentinaFil: Charras, María D.. Gobierno de la Provincia de Buenos Aires. Hospital Doctor Ramón Carrillo; ArgentinaFil: Peyrano, Alberto J.. Hospital Materno Provincial Dr. Raúl Felipe Lucini; ArgentinaFil: Montenegro, Clara. Hospital Materno Provincial Dr. Raúl Felipe Lucini; ArgentinaFil: Sosa Boye, Ignacio. No especifíca;Fil: Burgos, Verónica. Universidad Católica de Córdoba. Facultad de Medicina. Clínica Universitaria Reina Fabiola; ArgentinaFil: Giusti, Graciela. Clínica y Maternidad del Sol; ArgentinaFil: Espósito, Mario. Clínica y Maternidad del Sol; ArgentinaFil: Blanco Pool, Silvyana S.. Hospital Misericordia Nuevo Siglo ; Gobierno de la Provincia de Cordoba; ArgentinaFil: Gurevich, Debora P.. Hospital Misericordia Nuevo Siglo ; Gobierno de la Provincia de Cordoba; ArgentinaFil: Ahumada, Luis A.. Hospital Misericordia Nuevo Siglo ; Gobierno de la Provincia de Cordoba; ArgentinaFil: Pontoriero, Ricardo D.. Hospital Misericordia Nuevo Siglo ; Gobierno de la Provincia de Cordoba; ArgentinaFil: Rizzotti, Alina. Hospital Privado Universitario de Córdoba; ArgentinaFil: Bas, José I.. Hospital Privado Universitario de Córdoba; ArgentinaFil: Vaca, María B.. Hospital Universitario de Maternidad y Neonatología; ArgentinaFil: Miranda, María J.. Hospital Universitario de Maternidad y Neonatología; ArgentinaFil: Ferreyra, Mirta E.. Hospital Misericordia Nuevo Siglo ; Gobierno de la Provincia de Cordoba; ArgentinaFil: Moreno, Gabriela C.. Gobierno de la Provincia de Buenos Aires. Hospital Doctor Ramón Carrillo; ArgentinaFil: Pedicino, Héctor. Hospital Italiano; ArgentinaFil: Rojas Rios, Melvy. Hospital Italiano; Argentin

Association between COVID-19 mandatory lockdown and decreased incidence of preterm births and neonatal mortality

Previous studies suggest a decrease in preterm births (PTB) during de coronavirus disease 2019 (COVID-19), possibly due to the effect of the mandatory lockdown. Nevertheless, other reports have been unable to confirm this finding. Most of these studies originated in high-income countries and evaluated a limited number of potential confounders, and all of them assessed a short lockdown period. In addition, an important question remains unanswered: How can we be sure that the observed changes are due to lockdown, when most of the pregnancies delivered in the lockdown period were conceived prior to it?To date there is insufficient evidence to support the notion that public health interventions during the lockdown prevent PTB . The aim of this study was to compare the incidence of PTB, neonatal mortality (NM) and stillbirths adjusted by potential confounders during the lockdown period assessing a time window of nine and a half months during which all the pregnancies analyzed in the exposed group were conceived after the lockdown, with the corresponding incidence in the previous year where all the unexposed pregnancies analyzed were conceived before the lockdown.publishedVersionFil: Cuestas, Eduardo. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas; Argentina.Fil: Cuestas, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: Gómez Flores, Martha E. Gobierno de la Provincia de Buenos Aires. Hospital Doctor Ramon Carrillo; Argentina.Fil: Charras, María D. Gobierno de la Provincia de Buenos Aires. Hospital Doctor Ramon Carrillo; Argentina.Fil: Peyrano, Alberto J. Hospital Materno Provincial Dr. Raúl Felipe Lucini; Argentina.Fil: Montenegro, Clara. Hospital Materno Provincial Dr. Raúl Felipe Lucini; Argentina.Fil: Sosa-Boye, Ignacio. Clínica Universitaria Reina Fabiola; Argentina.Fil: Burgos, Verónica. Clínica Universitaria Reina Fabiola; Argentina.Fil: Giusti, Graciela. Clínica y Maternidad del Sol; Argentina.Fil: Espósito, Mario. Clínica y Maternidad del Sol; Argentina.Fil: Blanco Pool, Silvyana S. Hospital Misericordia Nuevo Siglo; Argentina.Fil: Blanco Pool, Silvyana S. Sanatorio Allende; Argentina.Fil: Gurevich, Debora P. Sanatorio Allende; Argentina.Fil: Gurevich, Debora P. Hospital Misericordia Nuevo Siglo; Argentina.Fil: Ahumada, Luis A. Sanatorio Allende; Argentina.Fil: Ahumada, Luis A. Hospital Misericordia Nuevo Siglo; Argentina.Fil: Pontoriero, Ricardo D. Hospital Misericordia Nuevo Siglo; Argentina.Fil: Rizzotti, Alina. Hospital Privado Universitario de Córdoba; Argentina.Fil: Bas, José I. Hospital Privado Universitario de Córdoba; Argentina.Fil: Vaca, María B. Hospital Universitario de Maternidad y Neonatología; Argentina.Fil: Miranda, María J. Hospital Universitario de Maternidad y Neonatología; Argentina.Fil: Ferreyra, Mirta E. Sanatorio del Salvador; Argentina.Fil: Ferreyra, Mirta E. Hospital Misericordia Nuevo Siglo; Argentina.Fil: Moreno, Gabriela C. Sanatorio del Salvador; Argentina.Fil: Pedicino, Héctor. Instituto Universidad Escuela de Medicina del Hospital Italiano; Argentina.Fil: Rojas-Rios, Melvy. Instituto Universidad Escuela de Medicina del Hospital Italiano; Argentina

First Sagittarius A* Event Horizon Telescope results. II. EHT and multiwavelength observations, data processing, and calibration

We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5–11 campaign. The observations were carried out with eight facilities at six locations across the globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. The majority of the 1.3 mm emission arises from horizon scales, where intrinsic structural source variability is detected on timescales of minutes to hours. The effects of interstellar scattering on the image and its variability are found to be subdominant to intrinsic source structure. The calibrated visibility amplitudes, particularly the locations of the visibility minima, are broadly consistent with a blurred ring with a diameter of ∼50 μas, as determined in later works in this series. Contemporaneous multiwavelength monitoring of Sgr A* was performed at 22, 43, and 86 GHz and at near-infrared and X-ray wavelengths. Several X-ray flares from Sgr A* are detected by Chandra, one at low significance jointly with Swift on 2017 April 7 and the other at higher significance jointly with NuSTAR on 2017 April 11. The brighter April 11 flare is not observed simultaneously by the EHT but is followed by a significant increase in millimeter flux variability immediately after the X-ray outburst, indicating a likely connection in the emission physics near the event horizon. We compare Sgr A*'s broadband flux during the EHT campaign to its historical spectral energy distribution and find that both the quiescent emission and flare emission are consistent with its long-term behavior.http://iopscience.iop.org/2041-8205Physic

First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multiwavelength Observations, Data Processing, and Calibration

We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5–11 campaign. The observations were carried out with eight facilities at six locations across the globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. The majority of the 1.3 mm emission arises from horizon scales, where intrinsic structural source variability is detected on timescales of minutes to hours. The effects of interstellar scattering on the image and its variability are found to be subdominant to intrinsic source structure. The calibrated visibility amplitudes, particularly the locations of the visibility minima, are broadly consistent with a blurred ring with a diameter of ∼50 μas, as determined in later works in this series. Contemporaneous multiwavelength monitoring of Sgr A* was performed at 22, 43, and 86 GHz and at near-infrared and X-ray wavelengths. Several X-ray flares from Sgr A* are detected by Chandra, one at low significance jointly with Swift on 2017 April 7 and the other at higher significance jointly with NuSTAR on 2017 April 11. The brighter April 11 flare is not observed simultaneously by the EHT but is followed by a significant increase in millimeter flux variability immediately after the X-ray outburst, indicating a likely connection in the emission physics near the event horizon. We compare Sgr A*’s broadband flux during the EHT campaign to its historical spectral energy distribution and find that both the quiescent emission and flare emission are consistent with its long-term behavior

Aislamiento e identificación de terpenos presentes en extractos de hojas maduras de Myrospermum frutescens.

Se realizó el aislamiento de un triterpeno y cuatro diterpenos de tipo cassano a partir del fraccionamiento del extracto de AcOEt/CH3OH de hojas maduras de Myrospermum frutescens. El estudio de los valores espectroscópicos de IR, 1H-RMN, 13C-RMN, DEPT 135 y experimentos de correlación hetereonuclear (HSQC y HMBC) permitieron establecer las estructuras de los compuestos: Estigmasterol (1), 6β-hidroxi-18-acetoxycassano-13,15-diene (2), 6β,-18-dihidroxicassano-13,15-dieno (3), 6β,13-dihidroxi-18-acetoxi-cassano-15-eno (4) y 6β,18,17-trihidroxicassano-14,15-dieno (5)

Aislamiento e identificación de terpenos presentes en extractos de hojas maduras de Myrospermum frutescens

Se realizó el aislamiento de un triterpeno y cuatro diterpenos de tipo cassano a partir del fraccionamiento del extracto de AcOEt/CH₃.OH de hojas maduras de Myrospermum frutescens. El estudio de los valores espectroscópicos de IR, 1H-RMN, 13C-RMN, DEPT 135 y experimentos de correlación hetereonuclear (HSQC y HMBC) permitieron establecer las estructuras de los compuestos: Estigmasterol (1), 6β-hidroxi-18-acetoxycassano-13,15-diene (2), 6β,-18-dihidroxicassano-13,15-dieno (3), 6β,13-dihidroxi-18- acetoxi-cassano-15,16-dieno (4) y 6β,18,17-trihidroxicassano- 13,15-dieno (5)

Preparacion y caracterización de algunos derivados del quitosano

Se prepararon algunos derivados a partir de quitosano extraído de cascará de camarón con peso molecular de 7,14 x10⁵ g/mol. El primero de estos derivados fue el carboximetilquitosano que se preparó por adición de ácido monocloroacético al quitosano dando un producto con peso molecular de 17,97 x 10⁵ g/mol y grado de desacetilación 2.79 %, el cual fue caracterizado por Espectrocopía Infrarrojo con Transformada de Fourier (FTIR). También se aciló el quitosano a través de una reacción con cinamaldehído obteniéndose N-Acil-quitosano como producto, el cual se caracterizó por pruebas de solubilidad y FTIR, con la cual se determinó la formación del producto. Se realizó el entrecruzamiento de quitosano con alcohol polivinilico y se caracterizo por FTIR y por su morfología superficial usando microscopia electrónica de barrido de electrones (SEM). Adicionalmente, se les determinó la biodegradabilidad como una alternativa eco-amigable y como material de manufactura. En estas pruebas se tomó en cuenta la pérdida de peso de la muestra, espesor y diámetro demostrando que la muestra del quitosano entrecruzado con alcohol polivinílico se degrada a una velocidad menor que la muestra sin entrecruzar. Por otro lado, también se prepararon hidrogeles por entrecruzamiento de quitosano y alcohol polivinílico seguido de entrecruzamiento con etilenglicol diglicil éter (Q-EDGE-PVA), los cuales fueron caracterizados por espectroscopia infrarrojo y por su morfología superficial usando microscopia electrónica de barrido de electrones (SEM)