Search results for "Respiration"
showing 10 items of 538 documents
Root-induced tree species effects on the source/sink strength for greenhouse gases (CH4, N2O and CO2) of a temperate deciduous forest soil
2013
Through their leaf litter and throughfall water, tree species can have a pronounced influence on soil chemistry. However, there is little knowledge of species-specific root effects on greenhouse gas fluxes between forest soils and the atmosphere. By growing saplings of beech (Fagus sylvatica) and ash (Fraxinus excelsior) in monoculture or mixture at defined atmospheric and soil conditions in rhizotrons, we tested four hypotheses related to potential root-induced tree species effects on the uptake of CH4 and the emission of N2O and CO2 from the soil. This design excluded putative effects of leaf litter mineralisation on trace gas fluxes. Gas fluxes were measured biweekly using the closed cha…
Cadmium-induced changes in soil biochemical characteristics of oat (Avena sativa L.) rhizosphere during early growth stages
2011
A microcosm was assembled to physically separate soil from roots and was used to study both the impact of living roots on the soil–plant system during early stages of growth and plant responses to abiotic stress. Oat (Avena sativa L.) seedlings were grown in the microcosm unit for 44 days. Twenty-three days after planting, 0.154 mg CdSO4/g dry soil was added. Plants grown in Cd-treated microcosms showed considerable inhibition of shoot growth rates, and leaf chlorophyll content. Soil microbial biomass C and respiration increased with plant age, and most of the measured biochemical indicators decreased with increasing distance from the soil–root interface, thus demonstrating the rhizosphere …
The impact of deep vein thrombosis in critically ill patients: a meta-analysis of major clinical outcomes
2015
Background. Critically ill patients appear to be at high risk of developing deep vein thrombosis (DVT) and pulmonary embolism during their stay in the intensive care unit (ICU). However, little is known about the clinical course of venous thromboembolism in the ICU setting. We therefore evaluated, through a systematic review of the literature, the available data on the impact of a diagnosis of DVT on hospital and ICU stay, duration of mechanical ventilation and mortality in critically ill patients. We also tried to determine whether currently adopted prophylactic measures need to be revised and improved in the ICU setting. Materials and methods. MEDLINE and EMBASE databases were searched up…
Bayesian joint modeling of bivariate longitudinal and competing risks data: An application to study patient-ventilator asynchronies in critical care …
2017
Mechanical ventilation is a common procedure of life support in intensive care. Patient-ventilator asynchronies (PVAs) occur when the timing of the ventilator cycle is not simultaneous with the timing of the patient respiratory cycle. The association between severity markers and the events death or alive discharge has been acknowledged before, however, little is known about the addition of PVAs data to the analyses. We used an index of asynchronies (AI) to measure PVAs and the SOFA (sequential organ failure assessment) score to assess overall severity. To investigate the added value of including the AI, we propose a Bayesian joint model of bivariate longitudinal and competing risks data. Th…
Model-Based Evaluation of Methods for Respiratory Sinus Arrhythmia Estimation
2021
OBJECTIVE: Respiratory sinus arrhythmia (RSA) refers to heart rate oscillations synchronous with respiration, and it is one of the major representations of cardiorespiratory coupling. Its strength has been suggested as a biomarker to monitor different conditions, and diseases. Some approaches have been proposed to quantify the RSA, but it is unclear which one performs best in specific scenarios. The main objective of this study is to compare seven state-of-the-art methods for RSA quantification using data generated with a model proposed to simulate, and control the RSA. These methods are also compared, and evaluated on a real-life application, for their ability to capture changes in cardior…
Nasal pressure swings as the measure of inspiratory effort in spontaneously breathing patients with de novo acute respiratory failure.
2022
Abstract Background Excessive inspiratory effort could translate into self-inflicted lung injury, thus worsening clinical outcomes of spontaneously breathing patients with acute respiratory failure (ARF). Although esophageal manometry is a reliable method to estimate the magnitude of inspiratory effort, procedural issues significantly limit its use in daily clinical practice. The aim of this study is to describe the correlation between esophageal pressure swings (ΔPes) and nasal (ΔPnos) as a potential measure of inspiratory effort in spontaneously breathing patients with de novo ARF. Methods From January 1, 2021, to September 1, 2021, 61 consecutive patients with ARF (83.6% related to COVID…
Use of xanthan gum and calcium ascorbate to prolong cv. Butirra pear slices shelf life during storage
2023
After cut, pear fruit (Pyrus communis L.) during shelf-life can be subjected to colour and flavour changes. To maintain flesh colour and firmness, different technologies could be employed during shelf-life, such as chemical, physical and edible coating treatments. In the present study, the effects of two edible coating formulations containing xanthan gum and calcium ascorbate on fresh-cut pear fruit were investigated. After harvest, 200 fruits were cut and coated with Xanthan Gum (XAN) and distilled water or Xanthan gum + Calcium Ascorbate (ASC), respectively, while control (CTR) pear fruit slices were soaked in distilled water and lastly packed in polyethylene terephthalate (PET) packages …
Quality changes in fresh-cut mango cubes submitted to different gas partial pressure of active MAPs
2018
The study was performed to assess chemical-physical and sensory quality changes in 4±1°C stored fresh-cut mangos and to test the effect of active modified atmosphere packaging (MAP) with different gas partial pressures. Sicilian fruits of ‘Keitt’ mango (Mangifera indica L.) were immerged in hydrogen peroxide (H2O2) after being peeled. Next, the flesh was cut in cubes and dipped in citric acid (0.5%, w/v) and ascorbic acid (0.5%, w/v). Treated fruits were placed in a non-perforated high density polyethylene package flushing different gas mixtures and kept at 4°C for 21 days. We used four different gas partial pressures: a) 60 kPa N2, 30 kPa CO2 and 10 kPa O2; b) 30 kPa CO2 and 70 kPa N2; c) …
Qualitative traits and shelf life of fig fruit (cv Melanzana) treated with Aloe vera gel coating
2021
The fig (Ficus carica L.) cv Melanzana is typical of Southern Italy. This cultivar produces breba fruit in June and fig fruit in August. Some previous studies on the use of coatings extracted from stems of Aloe vera showed positive effects to maintain fruit quality during shelf life. However, there are no studies on breba fig fruit treated with Aloe vera coating. In this study breba fig fruit, cv Melanzana, was treated with an application of Aloe vera gel, sealed in macro-perforated bag and stored at 5°C for 10 days. The effect of application of the Aloe vera gel on the shelf-life of this fruit, and its quality attributes after application were evaluated measuring fresh weight, total solubl…