48 research outputs found
Equipamiento ecoeficiente energético integrado al diseño arquitectónico del mercado minorista modelo de Chimbote - 2018
La presente investigación tuvo como propósito demostrar los beneficios del equipamiento ecoeficiente energético aplicada al diseño arquitectónico del mercado minorista modelo, mediante celdas fotovoltaicas multicristalinas aplicado en la cobertura de la edificación, mejorando el confort Térmico y haciéndolo energéticamente eficiente al edificio. La conversión de la radiación solar en electricidad sin partes móviles y sin combustible adicional, es una de las características que la hacen insustituible, reduce los costos de electricidad y es amigable con el medio ambiente. Para este proyecto se seleccionó un diseño de investigación de tipo descriptiva y con una propuesta de diseño no experimental, asimismo Transversal. El resultado esperado de esta solución fue eficiente, demostrando la factibilidad de un proyecto de este tipo en la ciudad favoreciendo el desarrollo económico, tecnológico, social y ambiental, dando de esta forma a la ciudad, una identidad cultural, reforzando su historia, tradición y costumbres, que permanecerá y será parte de la memoria colectiva de la población y visitantes. Dando respuestas favorables a las problemáticas, tanto en los aspectos económicos, tecnológicos, sociales y medio ambientales, tales como un excesivo consumo eléctrico, por la falta de conocimiento del potencial energético de la luz solar, aplicado adecuadamente en la arquitectura, por la falta de interés de nuestros gobernantes hacia la ecoeficiencia.Tesi
Short-term amiodarone therapy after reversion of persistent atrial fibrillation reduces recurrences at 18 months
Background: The aim of this study was to compare the outcome of 3 months vs. 18 months of amiodarone treatment after atrial fibrillation (AF) conversion in patients who experienced the first episode of persistent AF. Methods: We included 51 patients who experienced the first episode of persistent AF receiving amiodarone (600 mg) daily for 4–6 weeks. If AF persisted, electrical cardioversion (ECV) was performed. All patients received amiodarone (200 mg daily) for 3 months and then were randomized to amiodarone (Group I) or placebo (Group II) and followed for 15 months. The control group comprised 9 untreated patients undergoing ECV. Treatment effectiveness was evaluated using a Bayesian model. Results: Eighteen months after AF reversion, 22 (81.5%) patients in Group I, 13 (54.2%) patients in Group II, and 1 (11.1%) patient in the control group remained in sinus rhythm. No differences were found between Group I patients who required ECV and Group II patients. Sinus rhythm was preserved in all Group I patients when it was achieved during amiodarone administration. Limiting adverse effects occurred in 3 (11.1%) patients in Group I. Conclusions: In patients regaining sinus rhythm after the first episode of persistent AF, a 3-month amiodarone treatment after reversion is a reasonable option for rhythm control.
Automated Axial Right Ventricle to Left Ventricle Diameter Ratio Computation in Computed Tomography Pulmonary Angiography
Background and Purpose
Right Ventricular to Left Ventricular (RV/LV) diameter ratio has been shown to be a prognostic biomarker for patients suffering from acute Pulmonary Embolism (PE). While Computed Tomography Pulmonary Angiography (CTPA) images used to confirm a clinical suspicion of PE do include information of the heart, a numerical RV/LV diameter ratio is not universally reported, likely because of lack in training, inter-reader variability in the measurements, and additional effort by the radiologist. This study designs and validates a completely automated Computer Aided Detection (CAD) system to compute the axial RV/LV diameter ratio from CTPA images so that the RV/LV diameter ratio can be a more objective metric that is consistently reported in patients for whom CTPA diagnoses PE.
Materials and Methods
The CAD system was designed specifically for RV/LV measurements. The system was tested in 198 consecutive CTPA patients with acute PE. Its accuracy was evaluated using reference standard RV/LV radiologist measurements and its prognostic value was established for 30-day PE-specific mortality and a composite outcome of 30-day PE-specific mortality or the need for intensive therapies. The study was Institutional Review Board (IRB) approved and HIPAA compliant.
Results
The CAD system analyzed correctly 92.4% (183/198) of CTPA studies. The mean difference between automated and manually computed axial RV/LV ratios was 0.03±0.22. The correlation between the RV/LV diameter ratio obtained by the CAD system and that obtained by the radiologist was high (r=0.81). Compared to the radiologist, the CAD system equally achieved high accuracy for the composite outcome, with areas under the receiver operating characteristic curves of 0.75 vs. 0.78. Similar results were found for 30-days PE-specific mortality, with areas under the curve of 0.72 vs. 0.75.
Conclusions
An automated CAD system for determining the CT derived RV/LV diameter ratio in patients with acute PE has high accuracy when compared to manual measurements and similar prognostic significance for two clinical outcomes.Madrid-MIT M+Vision Consortiu
Effect of different doses of nitrogen and inoculation with Azospirillum brasilense on the productive characteristics of maize
This study assessed the effects of different nitrogen doses on maize crops, with and without the inoculation of Azospirillum brasilense. The experiment was carried out during the 2020/2021 harvest season in the administrative department of Concepción, district of Horqueta, Paraguay, at the coordinates of 23°14'31.7" S and 56°53'05.9" W. The experiment followed a randomized complete block design (RCBD) arranged in a factorial design (4 X 2). Factor A included nitrogen doses (0, 40, 80, and 120 kg ha-1), while factor B corresponded to the bacterial inoculation (with and without A. brasilense). The experiment was performed in three replications; each experimental unit (EU) was 22.5 m2. The study evaluated the following characteristics: plant height, cob insertion height, cob length and diameter, weight of 1000 kernels, and kernel yield. The data were analyzed using analysis of variance (ANOVA), and the averages were compared using Tukey's test at a 5% probability of error. Regression analysis was also carried out during the study. The experiment results demonstrated that increased nitrogen levels positively affected the measured characteristics, fitting a quadratic model, except for cob insertion height. Inoculation with A. brasilense significantly increased corn growth and productivity. The interaction of both factors produced a significant increase in cob length. Based on the experiment results, applying 104.30 kg ha-1 of N in combination with A. brasilense inoculation is recommended for improved maize production
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
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Full factorial design applied to the synthesis of Pd-?Ag nanobars by the polyol method and the perspective for ethanol oxidation
Full factorial design methodology was applied to the synthesis and optimization of Pd–Ag nanobars usingthe polyol process as the reducer. The concentration of Br? ions, the temperature and the reaction timewere selected as factors to study, whereas the yield (% nanobars) was the response to be analyzed. Thenanoparticles were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy,transmission electron microscopy, high-resolution transmission electron microscopy and X-rayphotoelectron spectroscopy. The nanoparticles were also tested for the ethanol electro-oxidationreaction by cyclic voltammetry in alkaline solution. The three factors had a positive effect onthe response: the nanobar yield increased as the level of the variables changed from ?1 to +1. Thetemperature and reaction time were the most determinant variables (main and interacting) on thenanobar yield, whereas the concentration of Br? influenced the yield to a lesser extent. After designingthree optimum experiments, a maximum nanobar yield of 47.3% was obtained. The more negativeelectro-oxidation onset, higher current density and more negative current peak potential show that theincorporation of Ag into Pd nanobars improves the kinetic and thermodynamic behavior towards theethanol electro-oxidation reaction compared with that obtained with nanometrically pure Pd nanobars.This improvement is the result of surface modification caused by the incorporation of Ag in theformation of Pd–Ag bimetallic nanobars with (200) surfaces
Aislamiento y control microbiológico de leuconostoc mesenteroides, en un ingenio para optimizar el rendimiento de azucar y etanol.
La caña de azúcar (Saccharum officinarum L) es exprimida para obtenersu jugo que después de ser purificado y neutralizado, deja cristalizar elazúcar Considerando la importancia que representa la caña de azúcarpara la industria azucarera, se hace necesario incrementar el contenido desacarosa libre de dextrana (destrucción de sacarosa causada por la acciónde microorganismos acompañantes de la caña, siendo uno de los másimportantes Leuconostoc mesenteroides). En este trabajo de investigaciónse determinó la inhibición de la bacteria ácido-láctica L. mesenteroidesaislada en un ingenio azucarero del Valle del Cauca mediante la utilizaciónde microorganismos antagonistas. Para esto, se realizaron aislamientos ycultivos de L. mesenteroides provenientes deljugo de la caña y se realizaronlas diferentes pruebas bioquímicas y microbiológicas en el laboratorio parael aislamiento y la identificación de las cepas tanto de Leuconostoc me¬senteroides, como las cepas bacterianas antagonistas a ella. Se comprobóque las cepas de los hongos Metharhizium anisopliae y Trichoderma sp,fueron las mas eficientes en el control de crecimiento de L. mesenteroi¬des; mostrando significativamente un mayor porcentaje de inhibición encomparación de los hongos filamentosos Colletotrichum sp, Thichodermaviridae, Rhizoctonia sp; y las bacterias Bacillus subtilis y Serratia marcensesy las levaduras Rhodothorula Rubra y KIoeckera japónica, no presentaroninhibición del crecimiento de Lmesenteroides. Además, se identificó a loshongos Aspergillus sp, Botrytis sp y Streptomyces sp como antagonistasnaturales y habituales presentes en el jugo de caña de los Ingenios