1,109 research outputs found

    Accelerated aging effect in physical and thermo-mechanical properties of maize starch biocomposites reinforced with agave salmiana fibers from different leaf ages

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    In this study, lignocellulosic fibers from Agave salmiana –an important socio-economical species endemic to Mexico– were used to reinforce thermoplastic maize starch (TPS). Fibers from young raw leaves (YRL) and old roasted leaves (ORL) were obtained according to the traditional methods used by small producers. The formulations of biocomposites were obtained varying the content of both types of fiber and processed by extrusion and injection molding. Morphological, structural, mechanical, thermal, and thermomechanical properties of biocomposites were evaluated. To use the hydrophilicity of these materials as an advantage in unexplored applications, biocomposites behavior under degradative tests such as accelerated aging and salt water immersion was evaluated. The processes of heating the old leaves partially removed the lignin and hemicellulose layer from the fibers, which led to a better interaction fiber-matrix, as confirmed by FESEM, ATR FTIR, and TGA. Biocomposites with 30 wt% of YRL fiber reported the highest values of tensile strength and Young’s modulus when compared to ORL biocomposites and with TPS. Accelerated aging exposure affected mainly the thermomechanical properties of TPS and confirmed the reinforcing effect of the fibers due to the thermal and mechanical stability they provided to the matrix, especially when 20 wt% of fiber was added. This was also observed when biocomposites were immersed in salt water solution. Using Agave salmiana fiber obtained from different leaf ages by traditional methods in the production of biocomposites promotes the complete harnessing of this species and represents a possibility to small producers in Mexico to introduce circular economy in their communities.A. Reyes-Samilpa acknowledges the scholarship 553944 from CONACYT; the mobility grant from CCA-IPN; the grants 251504 and 264110 from CONACYT, and 20195514 from SIP-IPN. We thank Dr. Edith Ariza from SEMAT Lab UMINHO and Dr. Ángel R. Hernández and M. C. Gerardo Fonseca from CFATA-UNAM for technical support in characterization tests; the Manuscript Writing Training Team (CEMAI in Spanish) of CONACyT for their help with reviews and constructive criticism, and Prof. Robert Leavitt and Maria del Sagrario Velasco García for also providing language help

    Low usage of government healthcare facilities for acute respiratory infections in guatemala: implications for influenza surveillance

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    <p>Abstract</p> <p>Background</p> <p>Sentinel surveillance for severe acute respiratory infections in hospitals and influenza-like illness in ambulatory clinics is recommended to assist in global pandemic influenza preparedness. Healthcare utilization patterns will affect the generalizability of data from sentinel sites and the potential to use them to estimate burden of disease. The objective of this study was to measure healthcare utilization patterns in Guatemala to inform the establishment of a sentinel surveillance system for influenza and other respiratory infections, and allow estimation of disease burden.</p> <p>Methods</p> <p>We used a stratified, two-stage cluster survey sample to select 1200 households from the Department of Santa Rosa. Trained interviewers screened household residents for self-reported pneumonia in the last year and influenza-like illness (ILI) in the last month and asked about healthcare utilization for each illness episode.</p> <p>Results</p> <p>We surveyed 1131 (94%) households and 5449 residents between October and December 2006 and identified 323 (6%) cases of pneumonia and 628 (13%) cases of ILI. Treatment for pneumonia outside the home was sought by 92% of the children <5 years old and 73% of the persons aged five years and older. For both children <5 years old (53%) and persons aged five years and older (31%) who reported pneumonia, private clinics were the most frequently reported source of care. For ILI, treatment was sought outside the home by 81% of children <5 years old and 65% of persons aged five years and older. Government ambulatory clinics were the most frequently sought source of care for ILI both for children <5 years old (41%) and persons aged five years and older (36%).</p> <p>Conclusions</p> <p>Sentinel surveillance for influenza and other respiratory infections based in government health facilities in Guatemala will significantly underestimate the burden of disease. Adjustment for healthcare utilization practices will permit more accurate estimation of the incidence of influenza and other respiratory pathogens in the community.</p

    SMART (Shop floor Modeling, Analysis and Reporting Tool Project

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    This document presents summarizes the design and prototype of the Shop floor Modeling, Analysis, and Reporting Tool (S.M.A.R.T.) A detailed description of it is found on the full documentation given to the NASA liaison. This documentation is also found on the A.R.I.S.E. Center web site, under a projected directory. Only authorized users can gain access to this site

    Momento Económico (44)

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    En este número Temas de hoy, José Antonio Moreno 2. México, deuda externa y la nueva renegociación, Fausto Burgueño 3. Solución, negociación o confrontación. (La deuda externa de México), Alicia Cirón C. 5 Plan Brady: ¿solución a la crisis de la deuda?, Patricia Olave C. 7. La crisis de la deuda, Ricardo Reyes H., Aristeo Tovías G. y Javier Villarreal A. 11. Fondo Monetario Internacional: nueva carta de buenas intenciones, Emilio Romero Blanco 16. Indicadores económicos, México: Relaciones comerciales con el Exterior 19. El menú o la moratoria, poco espacio para negociar, Pedro Medina 21. Algunos rasgos de la política económica del 'nuevo' gobierno, Leticia Campos Aragón 23. Las vicisitudes del pacto, José Antonio Moreno 29. Los informales de la economía, Patricia Rodríguez 30

    Fotoblastismo negativo en la especie invasora Eschscholzia californica Cham. (Papaveraceae): Patrones de variación altitudinal en el rango nativo e introducido

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    Negative photoblastism is defined as the inhibitory effect of light on seed germination. This effect can be modulated by abiotic variables, such as temperature, light condition and water potential. This conditions change notoriously at higher altitudes, could promote differentiations in the photoblastic response among populations. Also, this physiological attribute poses an interesting conflict for plant regeneration, because prevents seed germination on the soil surface, however, it can also to reduce the mortality of seeds germinants in unsuitable conditions and consequently, seedling mortality. Eschscholzia californica is one of the few species with negative photoblastism and it is invasive in Chile, growing primarily in open and disturbed places. Some invasive species have the potential to adapt their morphological and ecophysiological characteristics faced to new environmental conditions. In this study, we examined variation in negative photoblastism between populations from central Chile (invasive) and California (native) located at the extremes of their altitudinal distribution. We used common garden experiments where seeds from different origins were germinated under controlled lab condition in Chile. If negative photoblastism is conserved, we would see similar responses among seeds original from this climatic analogues regions. Also, we evaluated whether seed burial increases seed germination of this species as a mechanism for escaping the intense luminosity at the soil surface, by planting seeds at different soil depths. For this experiment, we expected an increase of germination at higher soil depth. The results indicate no differences in negative photoblastism between Chilean and Californian populations. A significant variation across altitudinal range in California suggests the existence of genetic differentiation in the native region, however, the absence of differences across the altitudinal range in Chile suggests trait conservatism at local scale. Seed germination was zero at the soil surface and increased when seeds were experimentally buried, suggesting that negative photoblastism is inhibited. Three possible explanations are given to explain the pattern of establishment of E. californica despite having negative photoblastism. This is a fairly specialist trait, related with Mediterranean climates and does not explain by itself the invasiveness described for this specie. In any case, is clear that more studies are necessary to disentangle the adaptive value of this physiological trait.El fotoblastismo negativo es definido como el efecto inhibitorio de la luz sobre la germinación de las semillas. Este efecto puede ser modulado por variables abióticas, tales como temperatura, condición lumínica y potencial hídrico. Estas condiciones cambian notoriamente a mayores altitudes, pudiendo promover diferenciación en la respuesta fotoblástica entre poblaciones. Adicionalmente, este atributo fisiológico presenta un interesante conflicto para la regeneración de la planta, porque previene la germinación de las semillas sobre el suelo, sin embargo también puede reducir la mortalidad de semillas germinantes en condiciones desfavorables y consecuentemente, la mortalidad de plántulas. Eschscholzia californica es una de las pocas especies con fotoblastismo negativo y es invasora en Chile, creciendo primariamente en sitios abiertos e intervenidos. Algunas especies invasoras tienen el potencial de adaptar sus características morfológicas y fisiológicas enfrentadas a nuevas condiciones ambientales. En este estudio, examinamos la existencia de variación en el fotoblastismo negativo entre poblaciones de Chile central (invasivas) y California (nativas) localizadas en los extremos de su distribución altitudinal. Utilizamos experimentos de jardín común donde semillas de distintos orígenes fueron germinadas bajo condiciones controladas de laboratorio en Chile. Si el fotoblastismo negativo es conservado, observaríamos similares respuestas entre semillas originarias de estas regiones climáticas análogas. También evaluamos si el entierro de las semillas incrementa su germinación, como un mecanismo para escapar de la intensidad luminosa de la superficie, plantando semillas a diferentes profundidades del suelo. Los resultados indican que no hay diferencias en el fotoblastismo negativo entre las poblaciones de Chile y California. Una significativa variación a través del rango altitudinal de California sugiere la existencia de diferenciación genética en la región nativa, sin embargo, la ausencia de diferencias a través del rango altitudinal de Chile sugiere conservatismo del rasgo a escala local. La germinación de semillas fue cero en la superficie del suelo y se incrementó cuando las semillas fueron experimentalmente enterradas, sugiriendo que el fotoblastismo negativo es inhibido. Tres posibles explicaciones son entregadas para explicar el patrón de establecimiento de E. californica a pesar de poseer fotoblastismo negativo. Este es un rasgo bastante especialista, relacionado con climas mediterráneos y no explica por sí solo la invasibilidad descrita para esta especie. De todas formas, es claro que más estudios son necesarios para dilucidar el valor adaptativo de este atributo fisiológico

    A Comparison of the Epidemiology and Clinical Presentation of Seasonal Influenza A and 2009 Pandemic Influenza A (H1N1) in Guatemala

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    A new influenza A (H1N1) virus was first found in April 2009 and proceeded to cause a global pandemic. We compare the epidemiology and clinical presentation of seasonal influenza A (H1N1 and H3N2) and 2009 pandemic influenza A (H1N1) (pH1N1) using a prospective surveillance system for acute respiratory disease in Guatemala.Patients admitted to two public hospitals in Guatemala in 2008-2009 who met a pneumonia case definition, and ambulatory patients with influenza-like illness (ILI) at 10 ambulatory clinics were invited to participate. Data were collected through patient interview, chart abstraction and standardized physical and radiological exams. Nasopharyngeal swabs were taken from all enrolled patients for laboratory diagnosis of influenza A virus infection with real-time reverse transcription polymerase chain reaction. We identified 1,744 eligible, hospitalized pneumonia patients, enrolled 1,666 (96%) and tested samples from 1,601 (96%); 138 (9%) had influenza A virus infection. Surveillance for ILI found 899 eligible patients, enrolled 801 (89%) and tested samples from 793 (99%); influenza A virus infection was identified in 246 (31%). The age distribution of hospitalized pneumonia patients was similar between seasonal H1N1 and pH1N1 (P = 0.21); the proportion of pneumonia patients <1 year old with seasonal H1N1 (39%) and pH1N1 (37%) were similar (P = 0.42). The clinical presentation of pH1N1 and seasonal influenza A was similar for both hospitalized pneumonia and ILI patients. Although signs of severity (admission to an intensive care unit, mechanical ventilation and death) were higher among cases of pH1N1 than seasonal H1N1, none of the differences was statistically significant.Small sample sizes may limit the power of this study to find significant differences between seasonal influenza A and pH1N1. In Guatemala, influenza, whether seasonal or pH1N1, appears to cause severe disease mainly in infants; targeted vaccination of children should be considered

    Prolonged exposure for the treatment of Spanish-speaking Puerto Ricans with posttraumatic stress disorder: a feasibility study

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    <p>Abstract</p> <p>Background</p> <p>Most of the empirical studies that support the efficacy of prolonged exposure (PE) for treating posttraumatic stress disorder (PTSD) have been conducted on white mainstream English-speaking populations. Although high PTSD rates have been reported for Puerto Ricans, the appropriateness of PE for this population remains unclear. The purpose of this study was to examine the feasibility of providing PE to Spanish speaking Puerto Ricans with PTSD. Particular attention was also focused on identifying challenges faced by clinicians with limited experience in PE. This information is relevant to help inform practice implications for training Spanish-speaking clinicians in PE.</p> <p>Results</p> <p>Fourteen patients with PTSD were randomly assigned to receive PE (n = 7) or usual care (UC) (n = 7). PE therapy consisted of 15 weekly sessions focused on gradually confronting and emotionally processing distressing trauma-related memories and reminders. Five patients completed PE treatment; all patients attended the 15 sessions available to them. In UC, patients received mental health services available within the health care setting where they were recruited. They also had the option of self-referring to a mental health provider outside the study setting. The Clinician-Administered PTSD Scale (CAPS) was administered at baseline, mid-treatment, and post-treatment to assess PTSD symptom severity. Treatment completers in the PE group demonstrated significantly greater reductions in PTSD symptoms than the UC group. Forty percent of the PE patients showed clinically meaningful reductions in PTSD symptoms from pre- to post-treatment.</p> <p>Conclusions</p> <p>PE appears to be viable for treating Puerto Rican Spanish-speaking patients with PTSD. This therapy had good patient acceptability and led to improvements in PTSD symptoms. Attention to the clinicians' training process contributed strongly to helping them overcome the challenges posed by the intervention and increased their acceptance of PE.</p

    Oxigenación con membrana extracorpórea en el paciente COVID-19: resultados del Registro Español ECMO-COVID de la Sociedad Española de Cirugía Cardiovascular y Endovascular (SECCE)

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    Background and aim: COVID-19 patients with severe heart or respiratory failure are potential candidates for extracorporeal membrane oxygenation (ECMO). Indications and management of these patients are unclear. Our aim is to describe the results of a prospective registry of COVID-19 patients treated with ECMO. Methods: An anonymous prospective registry of COVID-19 patients treated with veno-arterial (V-A) or veno-venous (V-V) ECMO was created on march 2020. Clinical, analytical and respiratory preimplantation variables, implantation data and post-implantation course data were recorded. The primary endpoint was all cause in-hospital mortality. Secondary events were functional recovery and the combined endpoint of mortality and functional recovery in patients followed at least 3 months after discharge. Results: Three hundred and sixty-six patients from 25 hospitals were analyzed, 347 V-V ECMO and 18 V-A ECMO patients (mean age 52.7 and 49.5 years respectively). Patients with V-V ECMO were more obese, had less frequently organ damage other than respiratory failure and needed less inotropic support; Thirty three percent of V-A ECMO and 34.9% of V-A ECMO were discharged (P = NS). Hospital mortality was non-significantly different, 56.2% versus 50.9% respectively, mainly during ECMO therapy and mostly due to multiorgan failure. Other 51 patients (14%) remained admitted. Mean follow-up was 196 +/- 101.7 days (95%CI: 170.8-221.6). After logistic regression, body weight (OR 0.967, 95%CI: 0.95-0.99, P = 0.004) and ECMO implantation in the own centre (OR 0.48, 95%CI: 0.27-0.88, P = 0.018) were protective for hospital mortality. Age (OR 1.063, 95%CI: 1.005-1.12, P = 0.032), arterial hypertension (3.593, 95%CI: 1.06-12.19, P = 0.04) and global (2.44, 95%CI: 0.27-0.88, P = 0.019), digestive (OR 4,23, 95%CI: 1.27-14.07, P = 0.019) and neurological (OR 4.66, 95%CI: 1.39-15.62, P = 0.013) complications during ECMO therapy were independent predictors of primary endpoint occurrence. Only the post-discharge day at follow-up was independent predictor of both secondary endpoints occurrence. Conclusions: Hospital survival of severely ill COVID-19 patients treated with ECMO is near 50%. Age, arterial hypertension and ECMO complications are predictors of hospital mortality, and body weight and implantation in the own centre are protective. Functional recovery is only predicted by the follow-up time after discharge. A more homogeneous management of these patients is warranted for clinical results and future research optimization. (C) 2022 Sociedad Espanola de Cirugia Cardiovascular y Endovascular. Published by Elsevier Espana, S.L.U

    Epidemiological and some clinical characteristics of neuroblastoma in Mexican children (1996–2005)

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    <p>Abstract</p> <p>Background</p> <p>Neuroblastoma (NB) is the principal tumor of the sympathetic nervous system in children under one year of age. The incidence in developed countries is greater than that in developing countries. The aim of this article is to present the epidemiological and some clinical characteristics of Mexican children with NB.</p> <p>Methods</p> <p>A population-based, prolective study, with data obtained from the Childhood Cancer Registry of the Instituto Mexicano de Seguro Social. Statistical analysis: The simple frequencies of the variables of the study and the annual average incidence (per 1,000,000 children/years) by age and sex were obtained. The trend was evaluated by calculating the annual percentage of change. The curves of Kaplan-Meyer were employed for the survival rate and the log-rank test was used to compare the curves.</p> <p>Results</p> <p>Of a total of 2,758 children with cancer registered during the period from 1996–2005, 72 (2.6%) were identified as having Group IV, defined according to the International Classification of Childhood Cancer. The incidence for NB was 3.8 per 1,000,000 children/year; NB was highest in the group of children under one year of age, followed by the group of children between the ages 1–4 years (18.5 and 5.4 per 1,000,000 children/years, respectively). The male/female ratio was 1.1 and there was no trend toward an increase. The time of diagnosis was 26 days (median), but varied according to the stage at diagnosis. Stages III and IV were presented in 88% of the cases. There was no association between the stage, the age at time of diagnosis, or the histological pattern. The overall five-year survival rate was 64%; the patients with stage I, II, III, or IVs did not die; and the five-year survival rate of cases in Stage IV was 40%.</p> <p>Conclusion</p> <p>It is possible that the low incidence of neuroblastoma in Mexican children is due to the difficulty in diagnosing the cases with the best prognosis, some of which could have had spontaneous regression. There was no trend to an increase; the majority of the cases were diagnosed in the advanced stages; and the overall five-years survival rate was similar to that for developed countries.</p

    Addressing the disparities in dementia risk, early detection and care in Latino populations: Highlights from the Second Latinos and Alzheimer's Symposium

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    The Alzheimer's Association hosted the second Latinos & Alzheimer's Symposium in May 2021. Due to the COVID-19 pandemic, the meeting was held online over 2 days, with virtual presentations, discussions, mentoring sessions, and posters. The Latino population in the United States is projected to have the steepest increase in Alzheimer's disease (AD) in the next 40 years, compared to other ethnic groups. Latinos have increased risk for AD and other dementias, limited access to quality care, and are severely underrepresented in AD and dementia research and clinical trials. The symposium highlighted developments in AD research with Latino populations, including advances in AD biomarkers, and novel cognitive assessments for Spanish-speaking populations, as well as the need to effectively recruit and retain Latinos in clinical research, and how best to deliver health-care services and to aid caregivers of Latinos living with AD
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