959 resultados para Lignin Units
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PURPOSE: The recent increase in drug-resistant micro-organisms complicates the management of hospital-acquired bloodstream infections (HA-BSIs). We investigated the epidemiology of HA-BSI and evaluated the impact of drug resistance on outcomes of critically ill patients, controlling for patient characteristics and infection management. METHODS: A prospective, multicentre non-representative cohort study was conducted in 162 intensive care units (ICUs) in 24 countries. RESULTS: We included 1,156 patients [mean ± standard deviation (SD) age, 59.5 ± 17.7 years; 65 % males; mean ± SD Simplified Acute Physiology Score (SAPS) II score, 50 ± 17] with HA-BSIs, of which 76 % were ICU-acquired. Median time to diagnosis was 14 [interquartile range (IQR), 7-26] days after hospital admission. Polymicrobial infections accounted for 12 % of cases. Among monomicrobial infections, 58.3 % were gram-negative, 32.8 % gram-positive, 7.8 % fungal and 1.2 % due to strict anaerobes. Overall, 629 (47.8 %) isolates were multidrug-resistant (MDR), including 270 (20.5 %) extensively resistant (XDR), and 5 (0.4 %) pan-drug-resistant (PDR). Micro-organism distribution and MDR occurrence varied significantly (p < 0.001) by country. The 28-day all-cause fatality rate was 36 %. In the multivariable model including micro-organism, patient and centre variables, independent predictors of 28-day mortality included MDR isolate [odds ratio (OR), 1.49; 95 % confidence interval (95 %CI), 1.07-2.06], uncontrolled infection source (OR, 5.86; 95 %CI, 2.5-13.9) and timing to adequate treatment (before day 6 since blood culture collection versus never, OR, 0.38; 95 %CI, 0.23-0.63; since day 6 versus never, OR, 0.20; 95 %CI, 0.08-0.47). CONCLUSIONS: MDR and XDR bacteria (especially gram-negative) are common in HA-BSIs in critically ill patients and are associated with increased 28-day mortality. Intensified efforts to prevent HA-BSIs and to optimize their management through adequate source control and antibiotic therapy are needed to improve outcomes.
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Lignin is the defining constituent of wood and the second most abundant natural polymer on earth. Lignin is produced by the oxidative coupling of three monolignols: p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol. Monolignols are synthesized via the phenylpropanoid pathway and eventually polymerized in the cell wall by peroxidases and laccases. However, the mechanism whereby monolignols are transported from the cytosol to the cell wall has remained elusive. Here we report the discovery that AtABCG29, an ATP-binding cassette transporter, acts as a p-coumaryl alcohol transporter. Expression of AtABCG29 promoter-driven reporter genes and a Citrine-AtABCG29 fusion construct revealed that AtABCG29 is targeted to the plasma membrane of the root endodermis and vascular tissue. Moreover, yeasts expressing AtABCG29 exhibited an increased tolerance to p-coumaryl alcohol by excreting this monolignol. Vesicles isolated from yeasts expressing AtABCG29 exhibited a p-coumaryl alcohol transport activity. Loss-of-function Arabidopsis mutants contained less lignin subunits and were more sensitive to p-coumaryl alcohol. Changes in secondary metabolite profiles in abcg29 underline the importance of regulating p-coumaryl alcohol levels in the cytosol. This is the first identification of a monolignol transporter, closing a crucial gap in our understanding of lignin biosynthesis, which could open new directions for lignin engineering.
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In this study, glyoxalated alkaline lignins with a non-volatile and non-toxic aldehyde, which can be obtained from several natural resources, namely glyoxal, were prepared and characterized for its use in wood adhesives. The preparation method consisted of the reaction of lignin with glyoxal under an alkaline medium. The influence of reaction conditions such as the molar ratio of sodium hydroxide-to-lignin and reaction time were studied relative to the properties of the prepared adducts. The analytical techniques used were FTIR and 1H-NMR spectroscopies, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Results from both the FTIR and 1H-NMR spectroscopies showed that the amount of introduced aliphatic hydroxyl groups onto the lignin molecule increased with increasing reaction time and reached a maximum value at 10 h, and after they began to decrease. The molecular weights remained unchanged until 10 h of reaction time, and then started to increase, possibly due to the repolymerization reactions. DSC analysis showed that the glass transition temperature (Tg) decreased with the introduction of glyoxal onto the lignin molecule due to the increase in free volume of the lignin molecules. TGA analysis showed that the thermal stability of glyoxalated lignin is not influenced and remained suitable for wood adhesives. Compared to the original lignin, the improved lignin is reactive and a suitable raw material for adhesive formula
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The main objective of this study was to explore the suitability of Vitis vinifera as a raw material and alkaline lignin as a natural binder for fiberboard manufacturing. In the first step, Vitis vinifera was steam- exploded through a thermo-mechanical vapor process in a batch reactor, and the obtained pulp was dried, ground, and pressed to produce the boards. The effects of pretreatment factors and pressing conditions on the chemical composition of the fibers and the physico-mechanical properties of binderless fiberboards were evaluated, and the conditions that optimize these properties were found. A response surface method based on a central composite design and multiple-response optimization was used. The variables studied and their respective variation ranges were: pretreatment temperature (Tr: 190-210ºC), pretreatment time (tr: 5-10 min), pressing temperature (Tp: 190-210ºC), pressing pressure (Pp: 8-16MPa), and pressing time (tp: 3-7min). The results of the optimization step show that binderless fiberboards have good water resistance and weaker mechanical properties. In the second step, fiberboards based on alkaline lignin and Vitis vinifera pulp produced at the optimal conditions determined for binderless fiberboards were prepared and their physico-mechanical properties were tested. Our results show that the addition of about 15% alkaline lignin leads to the production of fiberboards that fully meet the requirements of the relevant standard specifications
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Epoxidization is an interesting way to develop a new application of lignin and therefore to improve its application potential. In this work, kraft lignin-based epoxy resins were obtained by the epoxidization reaction, using the kraft lignin recovered directly from pulping liquor and modified by a methylolation reaction. The methylolated lignins were obtained by the reaction of original kraft lignin with formaldehyde and glyoxal, which is a less volatile and less toxic aldehyde. 1H-NMR spectroscopy showed that methylolated kraft lignin has more hydroxymethyl groups than glyoxalated kraft lignin. For the epoxidization reaction we studied the influence of the lignin:NaOH (w/w) ratio, temperature, and time of the reaction on the properties of the prepared epoxidized lignins. The structures of lignin-based epoxy resins were followed by epoxy index test and FTIR spectroscopy. Optimal conditions were obtained for lignin-based epoxy resin produced at lignin/NaOH = 1/3 at 70 ºC for 3h. Thermogravimetry analysis (TGA) revealed that the epoxidization enhances the thermal stability of lignins and may allow a wider temperature range for applications with lignin epoxy-PF blends
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Besides polyurethanes and polyesters, phenolic and epoxy resins are the most prominent applications for technical lignins in thermosetting materials. To evaluate the potential application of lignin raw materials in phenol formaldehyde and epoxy resins, three types of alkaline lignins were characterized in terms of their structures and thermal properties. The lignin samples analyzed were kraft lignin (LIG-1), soda–rice straw lignin (LIG-2), and soda-wheat straw lignin (LIG-3). FTIR and 1H-NMR methods were used to determine their structure. Gel permeation chromatography (GPC) was used to determine the molecular weight distribution (MWD). Differential scanning calorimetry (DSC) was used to measure the glass transition temperature (Tg), and thermogravimetric analysis (TGA) to determine the thermal stability of lignin samples. Results showed that kraft lignin (LIG-1) has moderate hydroxyl-group content, is rich in G-type units, and has good thermal stability. These properties make it more suitable for direct use in phenol formaldehyde resins, and it is therefore a good raw material for this purpose. The alkaline soda-rice straw lignin (LIG-2) with a high hydroxyl-group content and excellent thermal stability is most suited to preparing lignin-based epoxy resin
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La campanya electoral de Barack Obama per guanyar les eleccions nord-americanes l'any 2008 s'ha convertit en el referent de les e-campanyes. En aquesta investigació es fa una anàlisi de l'estratègia que va plantejar el candidat demòcrata a internet enfront les que van plantejar els principls candidats a les Eleccions Generals espanyoles el 2011: Mariano Rajoy (PP), Alfredo Pérez Rubalcaba (PSOE) i Josep Antoni Duran i Lleida (CiU). La investigació es planteja des de l'àmbit de la comunicació política a través d'una perspectiva comparativa i pren, fonamentalment, caràcter qualitatiu.
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Cet article fait suite à deux articles parus récemment dans la Revue Internationale de Psychologie Sociale traitant de la norme d'internalité et de sa mesure (Beauvois & Dubois, 2009a; Delmas, 2009). Dans un premier temps, nous discutons des confusions et glissements entre deux courants perçus bien souvent comme proches: l'approche du Locus of control et la théorie de la norme d'internalité. Nous pointons ensuite quelques difficultés méthodologiques qui ont alimenté ces confusions. Enfin, nous proposons de prendre en compte ces difficultés en redéfinissant le statut de la mesure en fonction d'une unité d'analyse plus adaptée pour l'étude de la norme d'internalité: les explications causales et non les individus. Ce changement d'unités d'analyse nous amènera à proposer une méthode plus adaptée pour l'étude de la normativité des explications causales : l'échantillonnage aléatoire des items composant ces questionnaires.
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BACKGROUND: Observational studies on mechanical ventilation (MV) show practice variations across ICUs. We sought to determine, with a case-vignette study, the heterogeneity of processes of care in ICUs focusing on mechanical ventilation procedures, and whether organizational patterns or physician characteristics influence practice variations. METHODS: We conducted a cross-sectional multicenter study using the case-vignette methodology. Descriptive analyses were calculated for each organizational pattern and respondent characteristics. An Index of Qualitative Variation (IQV, from 0, no heterogeneity, to a maximum of 1) was calculated. RESULTS: Forty ICUs from France (N = 33) and Switzerland (N = 7) participated; 396 physicians answered our case-vignettes. There was major heterogeneity of management processes related to MV within and across centers (mean IQV per center 0.51, SD 0.09). We observed the lowest variability (mean IQV per question < 0.4) for questions related to intubation procedure, ventilation of acute respiratory distress syndrome and the use of the semirecumbent position. We observed a high variability (mean IQV per question > 0.6) for questions related to management of endotracheal tube or suctioning, management of sedation and analgesia, and respect of autonomy. Heterogeneity was independent of respondent characteristics and of the presence of written procedures. There was a correlation between the processes associated with the highest variability (mean IQV per question > 0.6) and the annual volume of ICU admission (r = 0.32 (0.01 to 0.58)) and MV (r = 0.38 (0.07 to 0.63)). Within ICUs there was a large heterogeneity regarding knowledge of a local written procedure. CONCLUSIONS: Large clinical practice variations were found among ICUs. High volume centers were more likely to have heterogeneous practices. The presence of a local written procedure or respondent characteristics did not influence practice variation.
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Pseudomonas aeruginosa, une bactérie environnementale ubiquitaire, est un des pathogènes nosocomiaux les plus fréquents aux soins intensifs. La source de ce microorganisme peut être soit endogène, 2,6 à 24 % des patients hospitalisés étant colonisés au niveau digestif, soit exogène. La proportion des cas d'infections à P. aeruginosa d'origine exogène, donc secondaires à une transmission par manuportage ou par l'eau du réseau utilisée pour la toilette ou d'autres soins, reste débattue. Or une meilleure évaluation du taux d'infections exogènes est importante pour la mise en place de mesures de contrôle appropriées. Le but de cette étude était de déterminer sur une période de 10 ans les rôles respectifs des sources exogènes (robinets, autres patients) et endogène dans la colonisation et/ou l'infection par P.aeruginosa chez les patients des Soins Intensifs, ainsi que de documenter les variations épidémiologiques au cours du temps. L'étude a été menée dans les unités de Soins Intensifs du Centre Hospitalier Universitaire Vaudois (CHUV). Les patients colonisés et/ou infectés par P. aeruginosa entre 1998 et 2007ont été identifiés via la base de données du laboratoire de microbiologie. Ils ont été inclus dans l'étude s'ils étaient hospitalisés dans une des unités de Soins Intensifs, Durant cette période, des prélèvements pour recherche de P. aeruginosa ont été effectués sur des robinets des soins intensifs. Un typage moléculaire a été effectué sur toutes les souches cliniques et environnementales isolées en 1998, 2000, 2003, 2004 et 2007. Les patients inclus dans l'étude ont été répartis en quatre catégories (A-D) selon le résultat du typage moléculaire leur souche de P. aeruginosa. La catégorie A inclut les cas pour lesquels le génotype de P. aeruginosa est identique à un des génotypes retrouvé dans l'environnement. La catégorie B comprend les cas pour lesquels le génotype est identique à celui d'au moins un autre patient. La catégorie C comprend les cas avec un génotype unique et la catégorie D comprend les cas pour lesquels la souche était non disponible pour le typage. Les cas des catégories A et B sont considérés comme ayant une origine exogène. Au cours des années de l'étude, le nombre d'admissions aux soins intensifs est resté stable. En moyenne, 86 patients par année ont été identifiés colonisés ou infectés par P. aeruginosa aux Soins Intensifs. Durant la première année d'investigation, un grand nombre de patients colonisés par une souche de P. aeruginosa identique à une de celles retrouvées dans l'environnement a été mis en évidence. Par la suite, possiblement suite à l'augmentation de la température du réseau d'eau chaude, le nombre de cas dans la catégorie A a diminué. Dans la catégorie B, le nombre de cas varie de 1,9 à 20 cas/1000 admissions selon les années. Ce nombre est supérieur à 10 cas/1000 admissions en 1998, 2003 et 2007 et correspond à des situations épidémiques transitoires. Tout au long des 10 ans de l'étude, le nombre de cas dans la catégorie C (source endogène) est demeuré stable et indépendant des variations du nombre de cas dans les catégories A et B. En conclusion, la contribution relative des réservoirs endogène et exogène dans la colonisation et/ou l'infection des patients de soins Intensifs varie au cours du temps. Les facteurs principaux qui contribuent à de telles variations sont probablement le degré de contamination de l'environnement, la compliance des soignants aux mesures de contrôle des infections et la génétique du pathogène lui-même. Etant donné que ce germe est ubiquitaire dans l'environnement aqueux et colonise jusqu'à 15% des patients hospitalisés, la disparition de son réservoir endogène semble difficile. Cependant, cette étude démontre que son contrôle est possible dans l'environnement, notamment dans les robinets en augmentant la température de l'eau. De plus, si une souche multi-résistante est retrouvée de manière répétée dans l'environnement, des efforts doivent être mis en place pour éliminer cette souche. Des efforts doivent être également entrepris afin de limiter la transmission entre les patients, qui est une cause importante et récurrente de contamination exogène. - Pseudomonas aeruginosa is one of the leading nosocomial pathogens in intensive care units (ICUs). The source of this microorganism can be either endogenous or exogenous. The proportion of cases as a result of transmission is still debated, and its elucidation is important for implementing appropriate control measures. To understand the relative importance of exogenous vs. endogenous sources of P. aeru¬ginosa, molecular typing was performed on all available P. aeruginosa isolated from ICU clinical and environmental specimens in 1998, 2000, 2003, 2004 and 2007. Patient samples were classified according to their P. aeruginosa genotypes into three categories: (A) identical to isolate from faucet; (B) identical to at least one other patient sample and not found in faucet; and (C) unique genotype. Cases in cat¬egories A and Β were considered as possibly exogenous, and cases in category C as possibly endogenous. A mean of 34 cases per 1000 admissions per year were found to be colonized or infected by P. aeruginosa. Higher levels of faucet contamination were correlated with a higher number of cases in category A. The number of cases in category Β varied from 1.9 to 20 cases per 1000 admissions. This num¬ber exceeded 10/1000 admissions on three occasions and was correlated with an outbreak on one occasion. The number of cases con¬sidered as endogenous (category C) was stable and independent of the number of cases in categories A and B. The present study shows that repeated molecular typing can help identify variations in the epidemiology of P. aeruginosa in ICU patients and guide infection control measures.
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A hybrid study combining technological production and methodological research aiming to establish associations between the data and information that are part of a Computerized Nursing Process according to the ICNP® Version 1.0, indicators of patient safety and quality of care. Based on the guidelines of the Agency for Healthcare Research and Quality and the American Association of Critical Care Nurses for the expansion of warning systems, five warning systems were developed: potential for iatrogenic pneumothorax, potential for care-related infections, potential for suture dehiscence in patients after abdominal or pelvic surgery, potential for loss of vascular access, and potential for endotracheal extubation. The warning systems are a continuous computerized resource of essential situations that promote patient safety and enable the construction of a way to stimulate clinical reasoning and support clinical decision making of nurses in intensive care.
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This cross-sectional study aimed to analyze the adherence to drug and non-drug treatments in 17 Family Health Strategy units. A total of 423 patients with type 2 diabetes mellitus were selected through stratified random sampling in Family Health Strategy units of a city in the state of Minas Gerais, Brazil, in 2010. The results showed that the prevalence rate of adherence to drug therapy was higher than 60% in the 17 units investigated; in relation to physical activity, adherence was higher than 60% in 58.8% units; and for the diet plan, there was no adherence in 52.9% units. Therefore, we concluded that adherence to drug therapy in most units was high and the practice of physical activity was heterogeneous, and in relation to diet adherence, it was low in all units. We recommend strengthening of institutional guidelines and educational strategies, in line with SUS guidelines, so that, professionals may face the challenges imposed by the lack of adherence.
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Objective To identify the characteristics of managers and their use of management instruments in primary care and to analyze differences in these features among municipalities of different sizes. Method The present cross-sectional descriptive study was conducted at 108 basic health units from 21 municipalities in northern Paraná, Brazil. The data were collected using a semi-structured questionnaire during the second half of 2010. Results Most managers had graduate degrees and were female and nurses. The managers from the small municipalities were younger, their payment was lower, and they had less work experience. The use of management instruments was expressive for both the organization and work management; however, the instruments were used less in the small municipalities. Conclusion The managers were committed to their role; it is recommended that policies and guidance should be formulated at the federal and state levels to support small municipalities.