Electromovilidad en transporte forestal. ¿Es factible? Percepción de implementación en la industria chilena

This paper examines the different impressions and perspectives related to the implementation of electromobility in log transportation via trucks with a load capacity of up to 45 tons in the forestry sector of the eighth and sixteenth regions of Chile. The objective of this work is to establish the critical variables identified and perceived by key stakeholders of the forestry industry the correct implementation of high tonnage electric trucks. To this effect, a qualitative methodological study with a non-experimental design is proposed, which is based on semi-structured interviews conducted with stakeholders of the forestry sector of the study area. A convenience sample is employed, which was applied to four businessmen in the sector, three executives from the main forestry companies, and two truck distributor representatives. The data show that there is currently little knowledge due to the lack of specific projects and platforms for disseminating information that consider this technology in the field, but, on the contrary, they show a willingness to implement pilot plans aiming for the perceived economic sustainability of electromobility. A concentration of critical aspects is evidenced, which must be addressed in order to implement electromobility in forest transport, and which, given handling by public-private work, would enable the sector and the country to obtain the economic and environmental benefits of this technology.Este trabajo examina las distintas impresiones y perspectivas relacionadas con la implementación de electromovilidad en el transporte de rollizos con camiones de capacidad de carga de hasta 45 toneladas en el sector forestal de la octava y decimosexta región de Chile. El objetivo de este trabajo es establecer los aspectos críticos que los actores claves de la industria forestal identifican y perciben para una correcta implementación de camiones eléctricos de alto tonelaje. Para esto se propone un estudio metodológico de tipo cualitativo con un diseño no experimental basado en entrevistas semiestructuradas dirigidas a actores del sector forestal de la zona estudio. Se utiliza una muestra por conveniencia aplicada a 4 empresarios del rubro, 3 ejecutivos de empresas forestales principales y 2 representantes de distribuidores de camiones. Los datos muestran que actualmente hay poco conocimiento, derivado de la inexistencia de proyectos y plataformas de difusión específicos que consideren la tecnología en el rubro, pero, por el contrario, demuestran que existe una buena disposición por parte de los actores para implementar planes piloto con miras a la sustentabilidad económica que se le proyecta a la electromovilidad. Se evidencia una concentración de aspectos críticos que es necesario abordar para implementar la electromovilidad en el transporte forestal y que, atendidos por un trabajo público-privado, permitirían al rubro y al país obtener los beneficios económicos y ambientales de esta tecnología.

Amino β-cyclodextrins immobilized on gold surfaces: Effect of substituents on host-guest interactions

In the present paper we describe a simple method to immobilize amino cyclodextrins (CDs) and methylated-amino cyclodextrins on gold surfaces. We also report on the effect that the presence of methyl groups in the broader rim of the cyclodextrin causes on the interaction with the guest molecule bentazon. By means of electrochemical measurements, X-ray photoelectron spectroscopy and contact angle experiments we have demonstrated that the CDs attach covalently to the gold surfaces by amide bond formation and that the CD cavity is oriented opposite to the gold surface. We have shown that methylated-CD/Au modified surfaces are more sensitive towards the recognition of the herbicide bentazon than the non-methylated variants. The association constants for the corresponding interactions of the immobilized CD with the guest molecule have been determined from surface plasmon resonance experiments. The magnitudes of these constants (30.8 ± 1.0 M⁻¹ and 80.5 ± 4.2 M⁻¹ for amino-CD and methylated-amino cyclodextrins, respectively) are consistent with the change of hydrophobicity caused by methyl groups. The results demonstrate the feasibility of using CD-gold modified surfaces to encapsulate herbicides such as bentazon within the macrocyclic receptor without necessity of carrying out the experiments in solution

Habitabilidad y política de vivienda

En esta obra, en la que participan destacados investigadores y profesores, dedicados al estudio de la problemática habitacional se presentan diferentes análisis que permiten conocer cuales son las condiciones de habitabilidad y las características de la actual política de vivienda de México. En sus capítulos se abordan los principales desafíos que enfrentan las familias mexicanas para acceder a una vivienda digna y decorosa y cuales son los retos económicos, políticos, territoriales, arquitectónicos, ambientales, financieros y culturales de las formas de producción habitacional en México y en otros países, en el marco de una sociedad global

Compilación de Proyectos de Investigacion de 1984-2002

Instituto Politecnico Nacional. UPIICS

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

Background Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation. Methods WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109. Findings Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0–4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2–6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital. Interpretation In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

Background: Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation. Methods: WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109. Findings: Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital. Interpretation: In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates. Funding: European Society of Intensive Care Medicine, European Respiratory Society