Bases teóricas del efecto alelopático de la maleza (Cyperus rotundus), en la germinación y desarrollo en los cultivos de maíz (Zea mays L.) y frijol común (Phaseolus vulgaris L.)

La alelopatía es la liberación de compuestos químicos desde una especie vegetal, que tiene efectos negativos sobre especies vecinas. En las últimas décadas el estudio de la alelopatía ha incluido estudios de síntomas y severidad de los efectos adversos de las plantas vivas o de sus residuos sobre el crecimiento de las plantas superiores o cultivos, interacciones entre organismos, significado ecológico de la alelopatía en las comunidades vegetales, autotoxicidad, problemas en las rotaciones agrícolas y la producción y la identificación y aislamiento de los aleloquímicos tanto en ecosistemas naturales como en agroecosistemas. Los productos que poseen una acción alelopática son llamados aleloquímicos y se encuentran en las hojas, flores, frutos, tallos, raíces, rizomas, semillas y polen. Pueden ser liberados al ambiente a través de la volatilización, percolación, exudados por las raíces y por la descomposición de residuos vegetales. Las respuestas características son la estimulación o atracción a bajas concentraciones de aleloquímicos y la inhibición o repelencia a medida que la concentración se incrementa. Los efectos observables son la inhibición o retardo de la germinación, del crecimiento aéreo o radical y una disminución de la capacidad reproductiva de la planta. La aplicación de la alelopatía es una alternativa que puede ser incorporada dentro de un manejo racional de malezas. Su uso puede aplicarse en, mejorar la capacidad alelopática de los cultivares, uso de aleloquímicos como herbicidas naturales, uso de plantas alelopáticas con el cultivo, rotaciones con cultivos con efectos alelopáticos y uso de residuos vegetales de especies alelopáticas. Palabra clave: alelopatía, malezas, agroecosistema, cultiv

DISEÑO E IMPLEMENTACIÓN DE UN MULTÍMETRO DIGITAL CON FUNCIONES AMPLIADAS DE BAJO COSTO

ResumenEste documento describe el diseño e implementación de un multímetro digital de bajo costo para la medición de voltaje y corriente (directa y alterna), impedancia y temperatura. Para su implementación, se utilizó un divisor de voltaje, un sensor de corriente ACS712, el medidor de impedancias AD5933, un LM35 para la medición de temperatura. Después del acondicionamiento respectivo de cada sensor, las señales se adquirieron por un microcontrolador PIC16F877A para finalmente realizar el desplegado de datos en una pantalla de cristal líquido (LCD, por sus siglas en inglés) de 16x2. El multímetro diseñado realiza mediciones de 0 a 500 V, de 0 a 2 A, impedancias desde 1 kΩ hasta 10 MΩ y temperaturas de 0 a 150 ᵒC.  El multímetro posee rangos aceptables de medición, con la capacidad de realizar tales mediciones sin la necesidad de hacer un cambio de escala. De igual manera, su costo es menor comparado con equipos comerciales con capacidades similares.Palabras Claves: Corriente, impedancia, multímetro digital, temperatura, voltaje. DESIGN AND IMPLEMENTATION OF A DIGITAL MULTIMETER WITH EXTENDED LOW-COST FUNCTIONSAbstractThis document describes the design and implementation of a low-cost digital multimeter for measuring temperature, impedance, voltage and current. For its implementation, an ACS 712 current sensor, the AD5933 impedance meter, an LM35 for temperature measurement and a voltage divider for voltage measurement were used. After the respective conditioning of each sensor, the signals were acquired by a PIC16F877A microcontroller to finely perform the data display on a 16x2 LCD (liquid crystal display). The designed multimeter supports 0 to 500 V measurements, 0 to 2 A, 0 to 150 °C and impedance measurements from 1 kΩ to 10 MΩ.Keywords: Current, digital multimeter, impedance, temperature, voltage

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Las repercusiones de la contingencia sanitaria en el habitar y el replanteamiento de la vivienda como espacio flexible que priorice al usuario: caso de estudio zona Angelópolis en Puebla Pue.

"Por mucho tiempo la vivienda solía entenderse como un espacio de refugio y descanso, donde las personas llegaban tras sus actividades diarias, sin embargo, debido al aislamiento social provocado por el Covid -19, nuestro espacio de refugio y descanso pasó a ser un lugar de trabajo, estudio, convivencia, actividad física, etc. exponiendo claramente la deficiencia del espacio para adaptarse a estas y a futuras necesidades. La arquitectura convencional, donde el diseño de los espacios ya ha sido preestablecido sin considerarse el posible cambio de uso en dichos espacios, elementos arquitectónicos inamovibles y mobiliario poco versátil, han generado problemáticas para satisfacer los requerimientos cambiantes del habitar, lo que ha creado un motivo de discusión y de reflexión para replantear el diseño de espacios adecuados a las necesidades cambiantes y acordes a las limitaciones económicas del ocupante. Por ello, el objetivo de esta tesis es desarrollar modelos flexibles de vivienda en la Reserva Territorial Atlixcáyotl de la ciudad de Puebla que permitan el uso mixto y la ampliación de los espacios dependiendo la necesidad del habitante, con base a una reflexión previa de las problemáticas surgidas por el aislamiento social provocado por la pandemia del Covid-19"

Centro cultural y recreativo en Huauchinango, Puebla

"Investigación efectuada en el municipio de Huauchinango, Puebla; aplicada a resolver las necesidades culturales y recreativas de la población. Proyecto arquitectónico de un Centro Cultural y Recreativo que satisfaga las necesidades de la población." También es u n papel importante la inquietud de construir desarrollo de la sociedad actual la importancia del desarrollo arquitectónico. Crear conciencia de la carencia de la comunidad y la falta de espacios arquitectónicos enfocados a la cultura y la recreación de la población. Ya que en la actualidad es una necesidad prioritaria a nivel nacional de México un plan de desarrollo por la que la formación de cada individuo es muy importante. Presentar un proyecto arquitectónico que presente un centro cultural y recreativo de acuerdo a las necesidades de la población, equipamiento urbano y actividades económicas de la población esto es parte de las necesidades del proyecto

Alcohol-related liver disease: Clinical practice guidelines by the Latin American Association for the Study of the Liver (ALEH)

Alcohol-related liver disease (ALD) is a major cause of advanced chronic liver disease in Latin-America, although data on prevalence is limited. Public health policies aimed at reducing the alarming prevalence of alcohol use disorder in Latin-America should be implemented. ALD comprises a clinical-pathological spectrum that ranges from steatosis, steatohepatitis to advanced forms such as alcoholic hepatitis (AH), cirrhosis and hepatocellular carcinoma. Besides genetic factors, the amount of alcohol consumption is the most important risk factor for the development of ALD. Continuous consumption of more than 3 standard drinks per day in men and more than 2 drinks per day in women increases the risk of developing liver disease. The pathogenesis of ALD is only partially understood and recent translational studies have identified novel therapeutic targets. Early forms of ALD are often missed and most clinical attention is focused on AH, which is defined as an abrupt onset of jaundice and liver-related complications. In patients with potential confounding factors, a transjugular biopsy is recommended. The standard therapy for AH (i.e. prednisolone) has not evolved in the last decades yet promising new therapies (i.e. G-CSF, N-acetylcysteine) have been recently proposed. In both patients with early and severe ALD, prolonged abstinence is the most efficient therapeutic measure to decrease long-term morbidity and mortality. A multidisciplinary team including alcohol addiction specialists is recommended to manage patients with ALD. Liver transplantation should be considered in the management of patients with end-stage ALD that do not recover despite abstinence. In selected cases, increasing number of centers are proposing early transplantation for patients with severe AH not responding to medical therapy

Modulation of the p38 MAPK (mitogen-activated protein kinase) pathway through Bcr/Abl: implications in the cellular response to Ara-C

The chimaeric protein Bcr/Abl, the hallmark of chronic myeloid leukaemia, has been connected with several signalling pathways, such as those involving protein kinase B/Akt, JNK (c-Jun N-terminal kinase) or ERKs (extracellular-signal-regulated kinases) 1 and 2. However, no data about the p38 MAPK (mitogen-activated protein kinase) have been reported. Here, we present evidence showing that Bcr/Abl is able to modulate this signalling pathway. Transient transfection experiments indicated that overexpression of Bcr/Abl in 293T cells is able to activate p38 MAPK or induce p73 stabilization, suggesting that c-Abl and Bcr/Abl share some biological substrates. Interestingly, the control exerted by Bcr/Abl on the p38 MAPK pathway was not only mediated by the tyrosine kinase activity of Bcr/Abl, as the use of STI571 demonstrated. In fact, Bcr alone was able to induce p38 MAPK activation specifically through MKK3 (MAP kinase kinase 3). Supporting these observations, chronic myeloid leukaemia-derived K562 cells or BaF 3 cells stably transfected with Bcr/Abl showed higher levels of phosphorylated p38 MAPK compared with Bcr/Abl-negative cells. While Bcr/Abl-negative cells activated p38 MAPK in response to Ara-C (1-β-D-arabinofuranosylcytosine), Bcr/Abl-positive cells were unable to activate p38 MAPK, suggesting that the p38 MAPK pathway is not sensitive to Abl-dependent stimuli in Bcr/Abl-positive cells. Our results demonstrate that the involvement of Bcr/Abl in the p38 MAPK pathway is a key mechanism for explaining resistance to Ara-C, and could provide a clue for new therapeutic approaches based on the use of specific Abl inhibitors