Collagen-ß-cyclodextrin hydrogels for advanced wound dressings: super-swelling, antibacterial action, inflammation modulation, and controlled drug release.

A key strategy in enhancing the efficacy of collagen-based hydrogels involves incorporating polysaccharides, which have shown great promise for wound healing. In this study, semi-interpenetrating polymeric network (semi-IPN) hydrogels comprised of collagen (Col) with the macrocyclic oligosaccharide ß-cyclodextrin (ß-CD) (20-80 wt.%) were synthesised. Fourier-transform infrared (FTIR) spectroscopy confirmed the successful fabrication of these Col/ß-CD hydrogels, evidenced by the presence of characteristic absorption bands, including the urea bond band at ∼1740 cm-1, related with collagen crosslinking. Higher ß-CD content was associated with increased crosslinking, higher swelling, and faster gelation. The ß-CD content directly influenced the morphology and semi-crystallinity. All Col/ß-CD hydrogels displayed superabsorbent properties, enhanced thermal stability, and exhibited slow degradation rates. Mechanical properties were significantly improved with contents higher than ß-CD 40 wt.%. These hydrogels inhibited the growth of Escherichia coli bacteria and facilitated the controlled release of agents, such as malachite green, methylene blue, and ketorolac. The chemical composition of the Col/ß-CD hydrogels did not induce cytotoxic effects on monocytes and fibroblast cells. Instead, they actively promoted cellular metabolic activity, encouraging cell growth and proliferation. Moreover, cell signalling modulation was observed, leading to changes in the expression of TNF-α and IL-10 cytokines. In summary, the results of this research indicate that these novel hydrogels possess multifunctional characteristics, including biocompatibility, super-swelling capacity, good thermal, hydrolytic, and enzymatic degradation resistance, antibacterial activity, inflammation modulation, and the ability to be used for controlled delivery of therapeutic agents, indicating high potential for application in advanced wound dressings.

Two-dimensional phase unwrapping based on Fourier transforms and the Yukawa potential spectrum.

The two-dimensional phase unwrapping problem (PHUP) has been solved with discrete Fourier transforms (FTs) and many other techniques traditionally. Nevertheless, a formal way of solving the continuous Poisson equation for the PHUP, with the use of continuous FT and based on distribution theory, has not been reported yet, to our knowledge. The well-known specific solution of this equation is given in general by a convolution of a continuous Laplacian estimate with a particular Green function, whose FT does not exist mathematically. However, an alternative Green function called the Yukawa potential, with a guaranteed Fourier spectrum, can be considered for solving an approximated Poisson equation, inducing a standard procedure of a FT-based unwrapping algorithm. Thus, the general steps for this approach are described in this work by considering some reconstructions with synthetic and real data.

Mortality and associated risk factors in patients hospitalized due to COVID-19 in a Peruvian reference hospital.

OBJECTIVES: To determine the risk factors for in-hospital mortality in patients with COVID-19 from a Peruvian national hospital. METHODS: Retrospective cohort study of medical records of patients with COVID-19 hospitalized at Hospital Nacional Hipólito Unanue (HNHU) during the months of April to August 2020. The dependent variable was in-hospital mortality. Independent variables included sociodemographic and clinical characteristics, physical examination findings, oxygen saturation (SaO2) at admission, treatment received during hospitalization and laboratory results at admission. A Cox regression model was used to evaluate the crude and adjusted hazard ratios for associated factors. RESULTS: We included 1418 patients. Median age was 58 years (IQR 47-68 years) and 944 (66.6%) were male. The median length of hospitalization was 7 (4-13) days, and the mortality rate was 46%. The most frequent comorbidities were type 2 diabetes mellitus, hypertension, and obesity. In the adjusted analysis, mortality was associated with age (HR 1.02; 95%CI 1.02-1.03), history of surgery (HR 1.89; 95%CI 1.31-2.74), lower oxygen saturation at admission (HR 4.08; CI95% 2.72-8.05 for SaO2<70% compared to SaO2>94%), the presence of poor general condition (HR 1.81; 95% CI 1.29-2.53), altered state of consciousness (HR 1.58; 95%CI 1.18-2.11) and leukocyte levels (HR 1.01; 95%CI 1.00-1. 02). Treatment with ivermectin (HR 1.44; 95%CI 1.18-1.76) and azithromycin (HR 1.25; 95%CI 1.03-1.52) were associated with higher mortality. Treatment with corticosteroids at low to moderate doses was associated with lower mortality (HR 0.56 95%CI 0. 37-0. 86) in comparison to no steroid use. CONCLUSION: A high mortality was found in our cohort. Low oxygen saturation at admission, age, and the presence of hematological and biochemical alterations were associated with higher mortality. The use of hydroxychloroquine, ivermectin or azithromycin was not useful and was probably associated with unfavorable outcomes. The use of corticosteroids at moderate doses was associated with lower mortality.

BIRC6 Is Associated with Vulnerability of Carotid Atherosclerotic Plaque.

Carotid atherosclerotic plaque rupture can lead to cerebrovascular accident (CVA). By comparing RNA-Seq data from vascular smooth muscle cells (VSMC) extracted from carotid atheroma surgically excised from a group of asymptomatic and symptomatic subjects, we identified more than 700 genomic variants associated with symptomatology (p < 0.05). From these, twelve single nucleotide polymorphisms (SNPs) were selected for further validation. Comparing genotypes of a hospital-based cohort of asymptomatic with symptomatic patients, an exonic SNP in the BIRC6 (BRUCE/Apollon) gene, rs35286811, emerged as significantly associated with CVA symptomatology (p = 0.002; OR = 2.24). Moreover, BIRC6 mRNA levels were significantly higher in symptomatic than asymptomatic subjects upon measurement by qPCR in excised carotid atherosclerotic tissue (p < 0.0001), and significantly higher in carriers of the rs35286811 risk allele (p < 0.0001). rs35286811 is a proxy of a GWAS SNP reported to be associated with red cell distribution width (RDW); RDW was increased in symptomatic patients (p < 0.03), but was not influenced by the rs35286811 genotype in our cohort. BIRC6 is a negative regulator of both apoptosis and autophagy. This work introduces BIRC6 as a novel genetic risk factor for stroke, and identifies autophagy as a genetically regulated mechanism of carotid plaque vulnerability.

Study of the polyacrylate interpenetration in a collagen-polyurethane matrix to prepare novel hydrogels for biomedical applications.

Currently, the control of the properties of collagen based hydrogels represents a promising area of research to develop novel materials for biomedical applications. The crosslinking of the collagen with trifunctional polyurethane (PU) allows a hybrid matrix to be formed by improving the coupling with exogenous polymeric chains to generate innovative semi-interpenetrated network (semi-IPN) hydrogels. The incorporation of polyacrylate (PA) within a hybrid matrix of collagen-PU allows to regulate the structure and physicochemical properties such as polymerization rate, physicochemical crosslinking, thermal stability, storage module and swelling/degradation behavior of the 3D matrices in the hydrogel state, also exhibiting modulation of their in vitro biocompatibility properties. This work contemplates the study of the effect of PA concentration on the physicochemical properties and the in vitro biological response of these novel semi-IPN hydrogels based on collagen-PU-PA. The results indicate that semi-IPN hydrogels that include 20 wt% of PA exhibit improved swelling with respect to the collagen-PU hydrogel, controlling the degradation rate in acidic, alkaline and proteolytic media; showing E. coli inhibition capacity, high hemocompatibility and not altering the metabolism of monocytes and fibroblasts growing on them. Therefore, these novel hydrogels represent biomaterials with potential application in biomedical strategies such as wound healing dressings.

Protección social de las personas adultas mayores: Inclusión y equidad en Argentina durante el periodo 2003-2014 / Social protection for older adults: Inclusion and equity in Argentina during the period 2003-2014 / Proteção social do idoso: Inclusão e equidade na Argentina durante o período 2003-2014

RESUMEN En este artículo se reflexiona sobre las transformaciones del sistema previsional argentino durante el periodo 2003-2014, para abarcar las políticas de protección de los ingresos implementadas durante los gobiernos Kirchneristas. El objetivo principal es brindar evidencia empírica acerca de cómo las políticas implementadas impactaron en una mejora sustantiva de los niveles de cobertura y distribución del ingreso. El trabajo se desarrolla a partir de los datos de la Encuesta Permanente de Hogares. Entre los principales hallazgos es importante destacar que la estructura social se vio modificada al registrarse una expansión de la cobertura que, además en términos relativos, se concentró en la parte baja de la distribución del ingreso, es decir en los hogares más vulnerables. Asimismo, el mayor incremento relativo en la percepción de ingresos jubilatorios, en la parte baja de la distribución, se tradujo en mejoras distributivas del ingreso. Sin embargo, las políticas que se implementaron y transformaron el funcionamiento de la protección social en el sistema jubilatorio, requieren ser repensadas en una estrategia sustentable de largo plazo. CÓDIGOS JEL: O15, 131, 138.

ABSTRACT This article analyzes some transformations about the Argentine pension system during the period 2003-2014, to cover the income protection policies implemented during the "Kirchnerismo". The main objective is to provide empirical evidence about how the implemented policies impacted on a substantive improvement of coverage levels and income distribution. The study is developed from the data of the Permanent Household Survey (EPH) of the Institute of Statistics and Censuses (INDEC). Among the main findings it is important to highlight that the social structure was modified by an expansion of coverage, which was also concentrated in the lower part of the income distribution, that is to say in the most vulnerable households. Likewise the greater relative increase in the perception of retirement income was translated into significant income distributional improvements. However policies that were implemented and also transformed the functioning of social protection institutions in the pension system need to be rethought in a sustainable long-term strategy JEL CLASSIFICATION: O15, 131, 138.

RESUMO O artigo tem como objetivo propor critérios de alto nível, chamados de habilitação, que permitam tomar decisões quanto ao uso de diferentes metodologias, métodos e padrões existentes para o gerenciamento de projetos. Para isso, foi realizada uma pesquisa exploratória, descritiva e proativa, utilizando a técnica de revisão documental. Com base nisso, 32 critérios técnicos são estabelecidos, derivados de dez fatores que se enquadram em três categorias. Conclui-se que os critérios de habilitação para a tomada de decisão devem ser a responsabilidade social corporativa e a sustentabilidade, tendências que combinam a satisfação dos interesses das partes interessadas externas e internas; Nesse sentido, sugere-se um guia para sua validação no gerenciamento de projetos. Recomenda-se como futuras linhas de pesquisa, o teste empírico da proposta, bem como a incorporação das práticas de responsabilidade social corporativa e sustentabilidade no gerenciamento de projetos. CLASSIFICAÇÕES JEL: OI5, 131, 138.

Investigar en inglés: una necesidad apremiante / No disponible

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Maltrato infantil: actitud y conocimiento de odontólogos en Concepción, Chile / Attitude towards child abuse according to the knowledge of dentists in Concepción, Chile

El maltrato infantil (MI) es considerado un problema de salud pública mundial, ocurre en todos los países y en todos los grupos sociales y religiosos. El trabajo de los odontólogos implica la atención de gran cantidad de niños y en sesiones sucesivas lo que pone al profesional en un lugar privilegiado para la detección del MI. El propósito de esta investigación fue describir el conocimiento y la actitud frente al MI de los odontólogos pertenecientes a los nueve centros asistenciales de salud de Concepción, Chile. Se realizó un estudio exploratorio de enfoque cuantitativo, descriptivo y transversal. Se confeccionó una encuesta que recogió datos demográficos, conocimiento, actitud, sospecha y denuncia sobre MI. La población de estudio consistió en 53 odontólogos. Las pruebas estadísticas utilizadas fueron Chi cuadrado y Wilcoxon (Mann-Whitney U). En general el conocimiento es satisfactorio. Del 43,3 por ciento que declara haber sospechado alguna vez sobre casos de MI, sólo el 56,5 por ciento lo ha denunciado. Se encontró diferencia significativa (p: 0,0326) al relacionar las variables de género y conocimiento, siendo mayor en las mujeres. Sin embargo entre las variables género y actitud no hubo diferencia. Las variables: origen de la información recibida, número de años de trabajo, número de niños atendidos a la semana y estudios de postgrado resultaron independientes con respecto al númerode respuestas correctas de conocimiento. El origen de la fuente de información no se observó en la formación de pregrado de los profesionles, por esto se plantea entonces la necesidad de incorporar o reforzar el tema del MI en las asignaturas de pregrado en las Facultades de Odontología de la región.

Child abuse (CA) is considered to be a global public health problem, it manifests in all countries and in all social and religious groups. The role of dentists specialized in children involves a close and frequent relationship providing privileged circumstances for the detection of CA. The purpose of our study is to describe dentist attitudes and awareness concerning CA at nine health care centers in Concepción, Chile. A quantitative, descriptive and transversal exploratory analysis was performed by implementing a survey that collected demographic data, awareness, attitudes, suspicions and accusations of CA. The population size of the study consisted of 53 dentists. Chi square and Wilcoxon (Mann-Whitney U) were used as statistical tests. Largely, awareness was satisfactory. The variables of sex and awareness were significantly higher in women (p =0.0326). However, no differences were found among sex and attitudes. The information received by the dentists during their training, and the number of years of work experience did not correlate with awareness. The undergraduate training of the dentists did not provide any information on CA. This emphasizes the need to incorporate or reinforce the aspect of CA in undergraduate courses taught at the Faculties of Dentistry in Concepción, Chile.

Thermodynamics of chitinase partitioning in soy lecithin liposomes and their storage stability.

The goal of this study was to define the partitioning behavior of chitinase from Trichoderma spp. in soy lecithin liposomes, using a thermodynamic approach based on the partitioning variation with temperature. An effort has been made to define the liposomes, as well as free and immobilized enzyme stability during storage at 4 and 25 °C. The partition coefficients (K (o/w)) were greater than 1; therefore, the standard free energies of the enzyme transfer were negative, indicating an affinity of the enzymes for encapsulation in liposomes. The enthalpy calculation led to the conclusion that the process is exothermic. The presence of enzyme decreased the liposome storage stability from 70 days to an approximately 20 days at 25 °C and 30 days at 4 °C. Monitoring of the liposome's diameter demonstrated that their size and concentration decreased during storage. The liposome's diameters ranged from 1.06 to 3.30 µm. The higher percentage of liposome corresponded to a diameter range from 1.06 to 1.34 µm. This percentage increased during storage. There were no evidences for liposome fusion process. The stability of immobilized enzyme was increased in comparison with free chitinase.

Assessment of Mexico's program to use ethanol as transportation fuel: impact of 6% ethanol-blended fuel on emissions of light-duty gasoline vehicles.

Recently, the Mexican government launched a national program encouraging the blending of renewable fuels in engine fuel. To aid the assessment of the environmental consequences of this move, the effect of gasoline fuel additives, ethanol and methyl tert-butyl ether, on the tailpipe and the evaporative emissions of Mexico sold cars was investigated. Regulated exhaust and evaporative emissions, such as carbon monoxide, non-methane hydrocarbons, and nitrogen oxides, and 15 unregulated emissions were measured under various conditions on a set of 2005-2008 model light-duty vehicles selected based on sales statistics for the Mexico City metropolitan area provided by car manufacturers. The selected car brands are also frequent in Canada, the USA, and other parts of the world. This paper provides details and results of the experiment that are essential for evaluation of changes in the emission inventory, originating in the low-blend ethanol addition in light vehicle fuel.

Influencia de la administración de anticonceptivos orales sobre la frecuencia de receptor estrogénico y neoplasia intraepitelial cervical / Influence of oral contraceptive use on estrogen receptor frequency and intraepithelial cervix neoplasia

Se realizó un estudio en 56 pacientes sexualmente activas que presentaban algún grado de neoplasia intraepitelial cervical (NIC). A cada una de las pacientes se les aplicó un cuestionario general por medio del cual pudimos conocer su historia sexual-reproductiva. El grupo en estudio estuvo constituido por 29 pacientes con uso de anticonceptivos orales (AO) y 27 pacientes consideradas como control, por no haber utilizado nunca este tipo de planificación familiar. A cada una de las pacientes se les realizó una valoración colposcópica, durante la cual se tomó una parte de la lesión para estudio histopatológico y la otra para valoración del receptor estrogénico (RE) presente. Se encontró que la frecuencia de RE en el tejido neoplásico de las pacientes con uso de anticonceptivos (CAO) no es estadísticamente significativa (P > 0.05), con respecto a las pacientes sin uso de anticonceptivos (SAO). De la misma manera, cuando se analizaron otros factores de riesgo como inicio de vida sexual activa, edad de la primera gesta, número de compañeros sexuales y número de gestas, se encontraron constantemente no significativos (P > 0.05) cuando se compararon las medias de ambos grupos. Por medio de este estudio, no hemos encontrado ninguna evidencia clara de alguna relación etiológica entre el uso de anticonceptivos orales y neoplasia intraepitelial cervical, sin embargo, se observa que la estimulación sobre la producción de RE en las etapas tempranas es evidente, probablemente por el estímulo estrogénico de procedencia exógena.

Actividad de sialiltransferasa en la membrana espermática y su relación con fertilidad y esterilidad humanas / Sialyltransferase activity on spermatic membrane and its relationship with human fertility and sterility

La actividad de la sialiltransferasa (ST) fue determinada en los espermatozoides (spz) de sujetos normospérmicos (>80 X 10 6 spz/ml y mn[as del 75% de movilidad) y en los spz de pacientes con problemas de fecundidad (oligospérmicos < 20 y 10 6 spz/ml y menos del 20% de movilidad y astenospérmicos > 40 X 10 6 spz/ml y menos del 10% de movilidad). La actividad de la ST se cuantifica mediante la transferencia de radiactividad de CMP -3 H- siálico hacia el aceptor exógeno (fetuina desializada). El complejo enzima sustrato formado, al ser colocado en presencia del ácido fosfotúrgstico da un producto de fosfotungstato insoluble, el cual es retenido en un filtro de fibra de vidrio. La actividad enzimática disminuye en los spz de oligospérmicos en un 62 + - 5% con respecto a los spz de normospérmicos. La disminución de la actividad de la ST en los spz de pacientes infértiles permite suponer que esta enzima participa probablemente como causa directa de su patología y que su disminución obedece a un daño en la integridad estructural de la membrana espermática.(au)

Perfil potencial de membrana en el espermatozoide de mamífero durante la maduración, eyaculación y capacitación / Membrane potential profile in mamalian spermatozoa during maduration, ejaculation and capacitation

El potencial eléctrico a través de la membrana (U) se cuantificó mediante la acumulación del catión lípido-soluble radiactivo trifenilmetilfosfonio (TPMP+) en la membrana del espermatozoide. Los espermatozoides de mamíferos previamente lavados se incubaron en presencia de TPMP+ en un medio denominado K+ = baja o K+ - elevada hasta que se logra el estado de equilibrio (20 min a 37 grados centrígrados). La diferencia obtenida entre los medios de incubación, se trnsformó a valores de concentración conforme a la cantidad de TPMP+ acumulada en el volumen intracelular del espermatozoide, al ser insertados estos valores en la ecuación del Nernst se obtiene el U. Durante el proceso de maduración el U obtenido en los espermatozoides de mamífero de la región de la cabeza del epididímo fue de -75+ - mV, en los espermatozoides de la región del cuerpo y de la cola, el U obtenido fue de -60+ -5 y -52 + -3.5mV, respectivamente. En el espermatozoide eyaculado el U así obtenido es de -69 + -2 mV. Durante la capacitación, al incubar los espermatozoides de mamíferos en presencia de iones de Ca++ y el ionóforo A 23187 el U así obtenido es de -35 + - mV. Estos cambios en el U, son significativos ya que indican que cuando el espermatozoide se encuentra en estas condiciones fisiológicas se modifica la polaridad de la membrana a juzgar por la hiperpolatización y/o despolarización observada.