Individual and combined effects of chemical and mechanical power on postoperative pulmonary complications: a secondary analysis of the REPEAT study

Introduction: Intra-operative supplemental oxygen and mechanical ventilation expose the lungs to potentially injurious energy. This can be quantified as 'chemical power' and 'mechanical power', respectively. In this study, we sought to determine if intra-operative chemical and mechanical power, individually and/or in combination, are associated with postoperative pulmonary complications. Methods: Using an individual patient data analysis of three randomised clinical trials of intra-operative ventilation, we summarised intra-operative chemical and mechanical power using time-weighted averages. We evaluated the association between intra-operative chemical and mechanical power and a collapsed composite of postoperative pulmonary complications using multivariable logistic regression to estimate the odds ratios related to the effect of 1 J.min-1 increase in chemical or mechanical power with adjustment for demographic and intra-operative characteristics. We also included an interaction term to assess for potential synergistic effects of chemical and mechanical power on postoperative pulmonary complications. Results: Of 3837 patients recruited to three individual trials, 2492 with full datasets were included in the analysis. Intra-operative time-weighted average (SD) chemical power was 10.2 (3.9) J.min-1 and mechanical power was 10.5 (4.4) J.min-1. An increase of 1 J.min-1 in chemical power was associated with 8% higher odds of postoperative pulmonary complications (OR 1.08, 95%CI 1.05-1.10, p < 0.001), while the same increase in mechanical power raised odds by 5% (OR 1.05, 95%CI 1.02-1.08, p = 0.003). We did not find evidence of a significant interaction between chemical and mechanical power (p = 0.40), suggestive of an additive rather than synergistic effect on postoperative pulmonary complications. Discussion: Both chemical and mechanical power are independently associated with postoperative pulmonary complications. Further work is required to determine causality

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users

Propagación vegetativa de Quinual (Polylepis racemosa) utilizando diferentes dosis de Root - Hor y diferentes tipos de estacas en Chota, Cajamarca.

Polylepis racemosa conocido como “Quinual” es una especie difícil de propagar por semillas, el cual conlleva a buscar métodos alternativos de propagación vegetativa. Se planteó como objetivo de investigación determinar el efecto de diferentes dosis de Root – Hor y tipos de estacas en la capacidad rizogénica de Quinual (Polylepis racemosa) en Chota, Cajamarca. El estudio fue ejecutado en un vivero construido para tal fin, con un diseño completamente al azar (DCA) en arreglo factorial siendo el primer factor tipo de material de propagación con dos niveles [estacas semilignificadas (A1) y estacas lignificadas (A2)] y el segundo factor dosis de Root - Hor con cuatro niveles [(0 ml (B1), 5 ml (B2), 10 ml (B3) y 15 ml (B4)], con ocho tratamientos [ T1 (A1B0), T2 (AB2), T3 (A1B1), T4 (A2B1), T5 (A1B2), T6 (A2B2), T7 (A1B3), T8 (A2B3), con tres repeticiones y 30 unidades experimentales por parcela experimental, siendo un total de 720 estacas. Los indicadores evaluados fueron, porcentaje de enraizamiento (%), número de brotes, número de hojas, número de raíces, longitud de raíces, longitud de tallo, peso seco de la parte aérea, peso seco radicular y diámetro basal, también se determinó el índice de la calidad de la planta. Mejores progresos se obtuvieron en las medias de estacas lignificadas, en los indicadores: porcentaje de enraizamiento, número de brotes, número de hojas, número de raíces en el T2 con 64,4%; 2,8; 13,6; 18,3, respectivamente; para longitud del tallo, peso seco de la parte aérea, peso seco radicular se obtuvieron los más altos valores en media en el T8 con 33,9 cm; 9,9 g; 4,1 g, y el diámetro basal en el tratamiento T6 con 1,05 cm. En estacas semilignificadas se obtuvo la mayor longitud de raíces en el T1 con 32,2 cm respectivamente.ÍNDICE DE CONTENIDOS CAPÍTULO I. INTRODUCCIÓN........................................................................................ 15 1.1. Planteamiento del problema................................................................................... 15 1.2. Formulación del problema ..................................................................................... 17 1.3. Justificación ........................................................................................................... 17 1.4. Objetivos ................................................................................................................ 18 CAPÍTULO II. MARCO TEÓRICO .................................................................................... 19 2.1. Antecedentes .............................................................................................................. 19 2.1.1. A nivel mundial ................................................................................................... 19 2.1.2. A nivel nacional .................................................................................................. 20 2.1.3. A nivel regional ................................................................................................... 22 2.2. Bases teóricas – científicas ........................................................................................ 23 2.2.1. Bosque de Polylepis ............................................................................................ 23 2.2.2. Quinual (Género Polylepis)................................................................................. 24 2.2.3. Propagación vegetativa ....................................................................................... 28 2.2.4. Fitohormonas y reguladores de crecimiento. ...................................................... 32 2.2.5. Root Hor (Comercial Andina Industrial 2018) ................................................... 33 2.3. Marco conceptual ....................................................................................................... 34 2.3.1. Auxina ................................................................................................................. 34 2.3.2. Ácido indolbutírico ............................................................................................. 34 56 2.3.3. Estacas ................................................................................................................. 35 2.3.4. Estaca lignificada ................................................................................................ 35 2.3.5. Estaca semilignificada ......................................................................................... 35 2.3.6. Fitohormonas....................................................................................................... 35 2.3.7. Propagación de vegetativa................................................................................... 35 2.3.7. Regulador de crecimiento.................................................................................... 36 2.4. Hipótesis .................................................................................................................... 36 2.4.1. Hipótesis general ................................................................................................. 36 2.4.2. Hipótesis específicas ........................................................................................... 36 2.5. Operacionalización de variables ................................................................................ 37 2.5.1. Variable independiente........................................................................................ 37 2.5.2. Variables dependientes........................................................................................ 37 CAPITULO III. MARCO METODOLÓGICO.................................................................... 39 3.1. Tipo y nivel de investigación ..................................................................................... 39 3.2. Diseño de la investigación ......................................................................................... 39 3.3. Métodos de investigación .......................................................................................... 44 3.4. Población, muestra y muestreo .................................................................................. 52 3.5. Técnicas e instrumentos de recolección de datos ...................................................... 52 3.6. Técnicas de procesamiento y análisis de datos .......................................................... 55 3.7. Aspectos éticos........................................................................................................... 567 CAPÍTULO IV ..................................................................................................................... 57 RESULTADOS Y DISCUSIÓN .......................................................................................... 57 4.1. Descripción de resultados .......................................................................................... 57 4.1.1. Análisis de normalidad ........................................................................................... 57 4.1.2. Efecto de diferentes dosis de Root- Hor y tipos de estacas en la capacidad rizogénica de Polylepis racemosa..................................................................................... 58 a. Efecto en el porcentaje de enraizamiento .............................................................. 60 b. Efecto en el número de brotes................................................................................ 61 c. Efecto en el número de hojas ................................................................................. 62 d. Efecto en el número de raíces ................................................................................ 63 e. Efecto en la longitud de raíces ............................................................................... 64 f. Efecto en la longitud de tallo ................................................................................. 65 g. Efecto en el peso seco de la parte aérea ................................................................. 66 h. Efecto en el peso seco radicular ............................................................................. 67 i. Efecto en el diámetro basal .................................................................................... 68 4.1.3. Efecto de la interacción de diferentes dosis de Root-Hor y diferentes tipos de estacas sobre la capacidad rizogénica de Polylepis racemosa a lo largo de seis meses ... 68 a. Efecto en el número de estacas con brotes ................................................................ 68 b. Efecto en el número de hojas .................................................................................... 70 c. Efecto en el número de brotes ................................................................................... 718 4.1.4. Índices de calidad de la planta de Polylepis racemosa. .......................................... 72 4.2. Contrastación e hipótesis ........................................................................................... 77 4.3. Discusión de resultados.............................................................................................. 78 CAPÍTULO V....................................................................................................................... 88 CONCLUSIONES Y RECOMENDACIONES ................................................................... 88 CAPÍTULO VI ..................................................................................................................... 90 REFERENCIAS BIBLIOGRÁFICAS ................................................................................. 90 CAPÍTULO VII .................................................................................................................. 100 ANEXOS ............................................................................................................................ 100 Anexo 1. Instrumento de recolección de datos. .............................................................. 100 Anexo 2. Reporte de análisis de suelo. ........................................................................... 101 Anexo 3. Tablas .............................................................................................................. 102 Anexo 4. Panel fotográfico ............................................................................................. 10

High pressure and food conservation comparative high pressure biology

IATE Axe 2 : Structuration sous contraintes des agropolymères et réactivité des poudresInternational audienc

High pressure and food conservation comparative high pressure biology

IATE Axe 2 : Structuration sous contraintes des agropolymères et réactivité des poudresInternational audienc