Do aluminum (Al)-hyperaccumulator and phosphorus (P)-solubilising species assist neighbouring plants sensitive to Al toxicity and P deficiency?

We aimed to evaluate the facilitation effects of an aluminum (Al) hyperaccumulator species bearing cluster roots, Gevuina avellana, on the seedling growth and performance of an Al-intolerant and phosphorus (P)-deficient-sensitive plant, Vaccinium corymbosum. For this, seedlings of G. avellana and V. corymbosum were grown alone or together as follows: i) two G. avellana seedlings, ii) one G. avellana + one V. corymbosum and iii) two V. corymbosum, in soil supplemented with Al (as Al2(SO4)3) and in the control (without Al supplementation). We determined relative growth rate (RGR), photosynthetic rate, chlorophyll concentration, lipid peroxidation and Al and nutrient concentration [Nitrogen (N), P, potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and sulfur (S)] in leaves and roots of both species. The results showed that, in general, G. avellana did not assist V. corymbosum to enhance its RGR nor reduce its Al uptake. However, G. avellana assisted V. corymbosum in enhanced N acquisition and, consequently, to increase its chlorophyll concentration and photosynthetic rate. Besides, V. corymbosum had lower lipid peroxidation in leaves when grown in the soil with high Al supplementation in association with G. avellana. Our results suggest a facilitating effect of G. avellana to V. corymbosum when grown in soils with high Al concentration, by enhancing chlorophyll concentrations and photosynthetic rate, and decreasing the oxidative damage to lipids.

Validez de contenido de un ECOE en el pregrado de fisioterapia para el razonamiento clínico / Validity of content of a ECOE in the physiotherapy undergraduate for clinical reasoning

Introducción: El Examen Clínico Objetivo Estructurado (ECOE) es una metodología de evaluación que permite medir de manera válida las competencias clínicas en estudiantes de fisioterapia a través de estaciones previamente estandarizadas. Objetivo: Determinar la validez de contenido del instrumento ECOE-LM 2017 para la medición de competencias clínicas en el examen, evaluación, diagnóstico, pronóstico e intervención de una persona con lumbalgia mecánica en fisioterapia. Métodos: Se diseñó un instrumento de seis estaciones evaluado con la técnica de juicio de expertos, para posteriormente calcular la confiabilidad interobservador a través de Fleiss’ Kappa, por medio del ReCal; adicionalmente se identificó el índice de aceptabilidad. Resultados: Se obtiene un índice kappa de 0,82 (casi perfecto) que da cuenta de una buena confiabilidad para el instrumento. Conclusiones: Se cuenta con un instrumento con una buena concordancia para su empleo en los procesos educativos. (AU)

Introduction: The Objective Structured Clinical Examination (ECOE) is an evaluation methodology that allows to validly measure clinical competencies in Physiotherapy students through previously standardized stations. Objective: To determine the content validity of the ECOE-LM 2017 instrument for the measurement of clinical competencies in the examination, evaluation, diagnosis, prognosis and intervention of a person with mechanical low back pain in Physiotherapy. Methods: An instrument of six stations evaluated with the expert judgment technique was designed to subsequently calculate the inter-observer reliability, through Fleiss’ Kappa, by means of the ReCal, additionally the acceptability index was identified. Results: A Kappa index of 0.82 (almost perfect) is obtained, which shows good reliability for the instrument. Conclusions: There is an instrument with good agreement for its use in educational processes. (AU)

Sonication did not provide reliability to Maki technique for catheter related bloodstream infection diagnosis.

OBJECTIVE: The aim of our study was to analyze sonication and Maki techniques for diagnosis of catheter tip colonization and catheter-related bloodstream infection (CRBSI) on patients admitted to ICU. METHODS: Observational and prospective study in one Intensive Care Unit. Patients with some central venous catheter (CVC) at least for 7 days and catheter-related infection (CRI) suspicion (new episode of fever or sepsis) were included. We performed Maki technique followed by sonication of catheter tip. We compared area under the curve (AUC) of Maki, sonication, and techniques combination to diagnosis catheter tip colonization and CRBSI. RESULTS: We included 94 CVC from 87 CRI suspicion episodes. We found 14 cases of catheter tip colonization and 10 cases of CRBSI. Of the 14 catheter tip colonization cases, 7 (50.0%) were detected by Maki and sonication techniques, 6 (42.9%) were detected only by Maki technique, and 1 (7.1%) was detected only by sonication technique. Of the 10 CRBSI, 6 (60.0%) were detected by Maki and sonication techniques, 4 (40.0%) were detected only by Maki technique, and any only by sonication technique. We found higher AUC in Maki technique than in sonication technique to diagnosis of CRBSI (p=0.02) and to diagnosis of catheter tip colonization (p=0.03). No significant differences were found in AUC between Maki technique and combination techniques for diagnosis of catheter tip colonization (p=0.32) and of CRBSI (p=0.32). CONCLUSIONS: Sonication did not provide reliability to Maki technique for diagnosis of catheter tip colonization and CRBSI.

Fiabilidad interobservador de tres métodos de fotogrametría para medir la lordosis lumbar / Interobserver reliability in three scales used in photogrammetry to measure lumbar lordosis

Antecedentes y objetivo Actualmente, se considera la radiografía como la prueba estándar para medir la lordosis lumbar; sin embargo, requiere de una preparación especial y, además, existe el riesgo de exposición a radiación ionizante la cual es nociva para la salud. El costo en los equipos utilizados y la exposición a la radiación son factores que limitan la aplicación de este tipo de pruebas diagnósticas. La fotogrametría es capaz de identificar las particularidades de la postura corporal que permiten reconocer ángulos como el de la lordosis lumbar. Se hace necesario ampliar el conocimiento acerca de la fiabilidad a partir de estándares que proporcionen al profesional en fisioterapia protocolos con medidas reproducibles que le faciliten la toma de decisiones relacionadas con esta condición. Por lo tanto, el objetivo de este estudio es determinar la fiabilidad inter-evaluador de tres formas de fotogrametría para medir la lordosis lumbar en personas con dolor lumbar no específico. Metodología Se realizó un análisis de lordosis lumbar mediante dos programas (Kinovea y ADiBAS Posture) a una muestra de 26 personas con dolor lumbar. Se empleó Kinovea para la evaluación en 2D por medio del test de flechas y el ángulo lordótico. ADiBAS Posture se utilizó para calcular la lordosis en 3D. Tres evaluadores hicieron medidas a partir de las fotografías, usando tres protocolos de medición definidos para el estudio. Resultados El análisis llevado a cabo a través de ADiBAS Posture presenta un coeficiente de correlación intraclase (CCI) muy bueno, mientras que el test de flechas y ángulo lordótico resultaron tener CCI buenos. Por otra parte, la prueba de ángulo lordótico presentó diferencias significativas mientras que el de flechas y el análisis efectuado en 3D no presentaron diferencias significativas (p > 0,05). Conclusiones El análisis en 3D y el test de flechas para determinar la lordosis lumbar son pruebas con un nivel de fiabilidad muy bueno (AU)

Background and objective Radiography is currently considered the gold standard test for measuring lumbar lordosis. However, it requires special preparation and there is also a risk of exposure to ionizing radiation, which is harmful to health. The cost of the equipment used and exposure to radiation are factors that limit the application of this type of diagnostic test. Photogrammetry can identify distinctive features allowing recognition of angles such as those of lumbar lordosis. Knowledge needs to be increased on reliability based on standards that provide the physiotherapist protocols with reproducible measures that facilitate decision-making related to this condition. Therefore, the objective of this study is to determine the inter-rater reliability of three forms of photogrammetry to measure lumbar lordosis in people with non-specific low back pain. Methodology An analysis of lumbar lordosis was carried out with two software programmes (Kinovea and ADiBAS Posture) in a sample of 26 people. Kinovea was used for 2D evaluation by means of the arrow test and the lordotic angle. ADiBAS Posture was used to measure lordosis in 3D. Three assessors made measurements from the photographs using the three measurement protocols defined for the study. Results ADiBAS Posture analysis showed extremely good CCI, while the arrow and lordotic angle test proved to have good CCIs. On the other hand, the lordotic angle test showed significant differences while the arrow test and the 3D analysis showed no significant differences (p > 0.05). Conclusions The 3D analysis and arrow test to determine lumbar lordosis are tests with a particularly good level of reliability (AU)

Diseño de una prueba de equilibrio con características contextuales para adultos mayores / Design and validation of a balance test with context characteristics for older adults

Antecedentes La pérdida de equilibrio en los adultos mayores es multifactorial y aumenta el riesgo de caídas en esta población. Existen pruebas para evaluar el equilibrio, sin embargo, se centran en la evaluación de una sola tarea, en entornos estáticos, sin considerar las demandas del control postural en situaciones de la vida cotidiana, como la interacción de la persona con el contexto y las actividades multitarea. Objetivo Diseñar y validar una prueba de equilibrio para adultos mayores con características contextuales. Materiales y método Se desarrolló una metodología de recolección de datos mixta, con un diseño metodológico exploratorio secuencial DEXPLOX derivativo de un diseño de triangulación concurrente DITRIAC. Resultados Los resultados hallados en las primeras 3fases permitieron construir los ítems de la prueba de evaluación de equilibrio, luego se realizó la primera validación de expertos, con un coeficiente kappa de Fleiss de 0,4 y una validez de contenido de Lawshe de 0,95. La segunda validación por expertos dio como resultado en la validez facial una fuerza de concordancia interevaluadores excelente y una validez de contenido de Lawshe en relevancia de 0,95 y en pertinencia de 0,97. Conclusiones La prueba diseñada ha demostrado características de validez fuertes y puede ser aplicada en adultos mayores, pues se incluyen ítems que exigen respuestas somatosensoriales, como las que se realizan en las actividades de la vida diaria e ítems con actividades de doble tarea cognitivas en el contexto real (AU)

Background Balance impairment is multifactorial in older adults and increases risk of falls in this population. There are tests to evaluate balance; nevertheless, they are focused on the evaluation of a single task, in static environments, without representing postural control demands in everyday life situations, such as person interaction-context and multi-tasking activities. Objectives Design and validate a balance test with ecological validity for older adults. Materials and methods A mixed data collection methodology was developed, with an exploratory sequential DEXPLOX methodological design derived from a DITRIAC concurrent triangulation design. Results The results from the first 3phases permitted constructing the items of the balance assessment test to, then, conduct the first validation by experts, determining a Fleiss’ kappa of 0.4 and a Lawshe content validity ratio of 0.95. The second validation by experts yielded as a result in face validity an excellent strength of inter-rater agreement and a Lawshe content validity ratio of 0.95 in relevance and 0.97 in pertinence. Conclusions The test designed showed strong characteristics of ecological validity and can be applied to older adults, given that it includes items requiring somatosensory responses, like those performed in activities of daily living and items with cognitive dual task activities used in daily routines (AU)

[Design and validation of a balance test with context characteristics for older adults]. / Diseño de una prueba de equilibrio con características contextuales para adultos mayores.

BACKGROUND: Balance impairment is multifactorial in older adults and increases risk of falls in this population. There are tests to evaluate balance; nevertheless, they are focused on the evaluation of a single task, in static environments, without representing postural control demands in everyday life situations, such as person interaction-context and multi-tasking activities. OBJECTIVES: Design and validate a balance test with ecological validity for older adults. MATERIALS AND METHODS: A mixed data collection methodology was developed, with an exploratory sequential DEXPLOX methodological design derived from a DITRIAC concurrent triangulation design. RESULTS: The results from the first 3phases permitted constructing the items of the balance assessment test to, then, conduct the first validation by experts, determining a Fleiss' kappa of 0.4 and a Lawshe content validity ratio of 0.95. The second validation by experts yielded as a result in face validity an excellent strength of inter-rater agreement and a Lawshe content validity ratio of 0.95 in relevance and 0.97 in pertinence. CONCLUSIONS: The test designed showed strong characteristics of ecological validity and can be applied to older adults, given that it includes items requiring somatosensory responses, like those performed in activities of daily living and items with cognitive dual task activities used in daily routines.

Adding worms during composting of organic waste with red mud and fly ash reduces CO2 emissions and increases plant available nutrient contents.

Alkaline industrial wastes such as red mud and fly ash are produced in large quantities. They may be recycled as bulking agent during composting and vermicomposting, converting organic waste into soil amendments or plant growth media. The aim of this study was to assess the microbial parameters, greenhouse gas emissions and nutrient availability during composting and vermicomposting of household waste with red mud and fly ash 15% (dry weight). CO2, CH4 and N2O emissions were monitored during 6 months in controlled laboratory conditions and microbial biomass and phospholipid acids, N and P availability were analysed in the end-products. Higher CO2 emissions were observed during vermicomposting compared to composting. These emissions were decreased by red mud addition, while fly ash had no effect. Nitrate (NO3-N) content of the end-products were more affected by worms than by alkaline materials, while higher ammonium (NH4-N) contents were recorded for composts than vermicomposts. Red mud vermicompost showed higher soluble P proportion than red mud compost, suggesting that worm presence can counterbalance P adsorption to the inorganic matrix. Final composts produced with red mud showed no harmful heavy metal concentrations. Adding worms during composting thus improved the product nutrient availability and did not increase metal toxicity. From a practical point of view, this study suggests that for carbon stabilisation and end-product quality, the addition of red mud during composting should be accompanied by worm addition to counterbalance negative effects on nutrient availability.

Effect of rhizobacterial consortia from undisturbed arid- and agro-ecosystems on wheat growth under different conditions.

Plant growth-promoting rhizobacteria (PGPR) are studied as complements/alternatives to chemical fertilizers used in agriculture. However, poor information exists on the potential of PGPR from undisturbed ecosystems. Here, we have evaluated the plant growth-promoting (PGP) effect of rhizobacterial consortia from undisturbed Chilean arid ecosystems (Consortium C1) and agro-ecosystems (Consortium C2) on plant biomass production. The PGP effects of C1 and C2 were assayed in wheat seedlings (Triticum aestivum L.) grown in pots under growth chamber conditions and in pots placed in an open greenhouse under natural conditions, using two different Chilean Andisols (Piedras Negras and Freire series) kept either at 30 or 60% of their maximum water holding capacity (MWHC). PGP effects depended on the soil type, MWHC and the growth conditions tested. Although both consortia showed PGB effects in artificial soils relative to controls in growth chambers, only C1 provoked a PGP effect at 60% MWHC in phosphorus-poor soil of the 'Piedras Negras' series. At natural conditions, however, only C1 exhibited statistically significant PGP effects at 30% MWHC in 'Piedras Negras', yet and most importantly allowed to maintain similar plant biomass as at 60% MWHC. Our results support possible applications of rhizobacterial consortia from arid ecosystems to improve wheat growth in Chilean Andisols under water shortage conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: Wheat seedling inoculated with rhizobacterial consortia obtained from an undisturbed Chilean arid ecosystem showed improved growth in phosphorus-poor and partly dry soil. Arid ecosystems should be considered in further studies as an alternative source of microbial inoculants for agro-ecosystems subjected to stressful conditions by low nutrients and/or adverse climate events.

Early induction of Fe-SOD gene expression is involved in tolerance to Mn toxicity in perennial ryegrass.

Manganese (Mn) toxicity limits plant growth in acid soils. Although Mn toxicity induces oxidative stress, the role of superoxide dismutase (SOD, EC.1.15.1.1) isoforms in conferring Mn tolerance remains unclear. Seedlings of ryegrass cultivars Nui (Mn-sensitive) and Kingston (Mn-tolerant) were hydroponically grown at 2.4 (optimal) or 750 µM Mn (toxic) concentration, and harvested from 2 to 48 h. Kingston showed higher shoot Mn than Nui at 2.4 µM Mn. At toxic supply, shoot Mn concentration steadily increased in both cultivars, with Kingston having the highest accumulation at 48 h. An early (2 h) increase in lipid peroxidation under Mn excess occurred, but it returned (after 6 h) to the basal level in Kingston only. Kingston exhibited higher SOD activity than Nui, and that difference increased due to toxic Mn. In general, Mn-induced gene expression of Mn- and Cu/Zn-SOD isoforms was higher in Nui than Kingston. Nevertheless, under Mn excess, we found a greater Fe-SOD up-regulation (up to 5-fold) in Kingston compared to Nui. Thus, Fe-SOD induction in Kingston might explain, at least partly, its high tolerance to Mn toxicity. This is the first evidence that Mn toxicity causes differential gene expression of SOD isoforms in ryegrass cultivars in the short-term.

Lesser incidence of accidental catheter removal with femoral versus radial arterial access

Background Arterial catheterization is a frequent procedure in Intensive Care Units (ICUs). Accidental catheter removal (ACR) can cause severe and potentially life-threatening complications such as severe bleeding and vascular damage. Few data are available on accidental arterial catheter removal, and no studies have been found comparing the incidence of ACR between different arterial catheter sites. Objective To compare the incidence of ACR in femoral and radial arterial catheters. Research design Retrospective study. Setting A polyvalent ICU. Subjects All consecutive patients subjected to femoral or radial arterial catheterization. Measures The incidence of ACR per 100 catheter-days between groups was compared using Poisson regression. We considered ACR as the presence of unintended removal produced by the patient or healthcare personnel. Results A total of 2419 radial and 1085 femoral arterial catheters were inserted and remained in situ during 14,742 and 6497 days, respectively. We detected 45 cases of ACR with the femoral access and 162 cases with the radial access. The ACR rate was lower with the femoral access (4.1% vs 6.7% in the case of the radial access; p=0.003). Poisson regression analysis confirmed a lower incidence of ACR with the femoral versus the radial access (0.69 vs 1.10 ACR events per 100 catheter-days; OR 0.6, p=0.006, CI95% 0.01-0.83).Conclusions The incidence of ACR was found to be lower with the femoral than with the radial arterial catheters. In order to improve patient safety, it could be interesting to exhaustively monitor the incidence of ACR and adopt preventive measures, since ACR can give rise to serious complications (AU)

Antecedentes La cateterización arterial es un procedimiento frecuente en los pacientes de las Unidades de Cuidados Intensivos (UCI). La retirada accidental del catéter (ACR) puede conllevar graves complicaciones, potencialmente vitales, como la hemorragia y la lesión vascular. Existen pocos datos sobre la ACR de los catéteres arteriales y no hemos encontrado estudios que hayan comparado la incidencia de ACR entre los diferentes accesos de canalización arterial. Objetivo Comparar la incidencia de ACR entre los catéteres arteriales localizados en el acceso femoral y radial. Diseño del estudio Estudio retrospectivo. Lugar Una UCI polivalente. Sujetos Todos los pacientes consecutivos sometidos a canalización de arteria femoral o radial. Medidas La incidencia de ACR por 100 días de catéter entre grupos fue comparada mediante la regresión de Poisson. Se consideró ACR cuando se producía la retirada no programada del catéter por parte del propio paciente o por el personal. Resultados Se insertaron 2.419 catéteres en arteria radial que permanecieron durante 14.742 días, y 1.085 catéteres en arteria femoral que permanecieron durante 6.497 días. Se detectaron 45 casos de ACR en el sitio femoral y 162 casos en el sitio radial. Hubo una menor tasa de ACR en el sitio femoral que en el radial (4,1% vs 6,7%; p=0,003). La regresión de Poisson mostró una menor incidencia de ACR en el sitio femoral que en el radial (0,69 vs 1,10 eventos de ACR por 100 días de catéter; OR 0,6, p = 0,006, IC95% 0,01-0,83).Conclusiones Encontramos una menor incidencia de ACR en el sitio femoral que en el radial. Pensamos, que para mejorar la seguridad de los pacientes podría ser interesante monitorizar exhaustivamente la incidencia de ACR e implementar medidas preventivas, debido a que la ACR puede conllevar complicaciones graves (AU)

Lesser incidence of accidental catheter removal with femoral versus radial arterial access.

BACKGROUND: Arterial catheterization is a frequent procedure in Intensive Care Units (ICUs). Accidental catheter removal (ACR) can cause severe and potentially life-threatening complications such as severe bleeding and vascular damage. Few data are available on accidental arterial catheter removal, and no studies have been found comparing the incidence of ACR between different arterial catheter sites. OBJECTIVE: To compare the incidence of ACR in femoral and radial arterial catheters. RESEARCH DESIGN: Retrospective study. SETTING: A polyvalent ICU. SUBJECTS: All consecutive patients subjected to femoral or radial arterial catheterization. MEASURES: The incidence of ACR per 100 catheter-days between groups was compared using Poisson regression. We considered ACR as the presence of unintended removal produced by the patient or healthcare personnel. RESULTS: A total of 2419 radial and 1085 femoral arterial catheters were inserted and remained in situ during 14,742 and 6497 days, respectively. We detected 45 cases of ACR with the femoral access and 162 cases with the radial access. The ACR rate was lower with the femoral access (4.1% vs 6.7% in the case of the radial access; p=0.003). Poisson regression analysis confirmed a lower incidence of ACR with the femoral versus the radial access (0.69 vs 1.10 ACR events per 100 catheter-days; OR 0.6, p=0.006, CI95% 0.01-0.83). CONCLUSIONS: The incidence of ACR was found to be lower with the femoral than with the radial arterial catheters. In order to improve patient safety, it could be interesting to exhaustively monitor the incidence of ACR and adopt preventive measures, since ACR can give rise to serious complications.

Ventilator-associated pneumonia with or without toothbrushing: a randomized controlled trial.

Certain guidelines for the prevention of ventilator-associated pneumonia (VAP) recommend oral care with chlorhexidine, but none refer to the use of a toothbrush for oral hygiene. The role of toothbrush use has received scant attention. Thus, the objective of this study was to compare the incidence of VAP in critical care patients receiving oral care with and without manual brushing of the teeth. This was a randomized clinical trial developed in a 24-bed medical-surgical intensive care unit (ICU). Patients undergoing invasive mechanical ventilation for than 24 h were included. Patients were randomly assigned to receive oral care with or without toothbrushing. All patients received oral care with 0.12 % chlorhexidine digluconate. Tracheal aspirate samples were obtained during endotracheal intubation, then twice a week, and, finally, on extubation. There were no significant differences between the two groups of patients in the baseline characteristics. We found no statistically significant differences between the groups regarding the incidence of VAP (21 of 217 [9.7 %] with toothbrushing vs. 24 of 219 [11.0 %] without toothbrushing; odds ratio [OR] = 0.87, 95 % confidence interval [CI] = 0.469-1.615; p = 0.75). Adding manual toothbrushing to chlorhexidine oral care does not help to prevent VAP in critical care patients on mechanical ventilation.

Lower catheter-related bloodstream infection in arterial than in venous femoral catheter.

In previous studies no differences were found in catheter-related bloodstream infection (CRBSI) between arterial and venous catheters. However, the distribution of each venous and arterial site could influence the results as in some studies a higher CRBSI incidence in venous and arterial femoral accesses has been found than in other venous and arterial accesses. Possibly, to eliminate this confounding, it might be more appropriate to compare the CRBSI incidence between arterial and venous catheters in the same site as the femoral access. Thus, the objective of this study was to compare the incidence of CRBSI between 618 arterial and 288 venous femoral accesses. We found higher CRBSI incidence in venous than in arterial femoral catheters (8.34 vs 1.92 CRBSI episodes/1,000 catheter-days; P < 0.001). Exact logistic regression analysis showed that venous femoral catheters had a higher risk of CRBSI than arterial femoral catheters (OR = 1.02; 95%CI =1.01-infinite; P < 0.001) controlled by APACHE-II score and duration of the catheter. The novel finding of our study is that the risk of CRBSI was higher in venous than in arterial femoral catheters. Thus, special approaches to prevent CRBSI might play a more important role in venous than in arterial catheters.

Rifampicin-miconazole-impregnated catheters save cost in jugular venous sites with tracheostomy.

Antimicrobial-impregnated catheters are more expensive than standard catheters (S-C). A higher incidence of catheter-related bloodstream infection (CRBSI) has been found in jugular venous access with tracheostomy than without tracheostomy. The objective of this study was to determine central venous catheter (CVC)-related costs (considering only the cost of the CVC, diagnosis of CRBSI, and antimicrobial agents used to treat CRBSI) using rifampicin-miconazole-impregnated catheters (RM-C) or S-C in jugular venous access with tracheostomy. We performed a retrospective cohort study of patients admitted to the intensive care unit (ICU) with tracheostomy who received one or more jugular venous catheters. RM-C showed a lower incidence of CRBSI compared with S-C (0 vs. 20.16 CRBSI episodes/1,000 catheter-days; odds ratio=0.05; 95% confidence interval=0.001-0.32; p<0.001) and lower CVC-related costs (including the cost of the CVC, diagnosis, and treatment of CRBSI) (11.46 ± 6.25 vs. 38.11 ± 77.25; p<0.001) in jugular venous access with tracheostomy. The use of RM-C could reduce CVC-related costs in jugular venous access with tracheostomy. The results of our study may contribute to clinical decision-making and selection of those patients who could benefit from the use of antimicrobial-impregnated catheters.

Lower incidence of catheter-related bloodstream infection in subclavian venous access in the presence of tracheostomy than in femoral venous access: prospective observational study.

Guidelines for the prevention of catheter-related bloodstream infection (CRBSI) recommend subclavian rather than femoral venous access to minimize the risk of CRBSI. However, they do not address the issue of CRBSI with subclavian venous access in the presence of tracheostomy, where the incidence of CRBSI has been found to be higher than without tracheostomy. In this study, we found lower CRBSI in subclavian venous access in the presence of tracheostomy than in femoral venous access (3.9 vs. 10.1 CRBSI per 1000 catheter-days; odds ratio = 0.39; 95% confidence interval ≤0.001-0.91; p 0.03).

Influence of tracheostomy on the incidence of catheter-related bloodstream infection in the catheterization of jugular vein by posterior access.

There are no data about the influence of tracheostomy in the incidence of catheter-related bloodstream infection (CRBSI) on the catheterization of the jugular vein by posterior access and there are no recommendations relating to this circumstance in the guidelines of the Centers for Disease Control and Prevention (CDC) and of Healthcare Epidemiology of America/Infectious Diseases Society of America (SHEA/IDSA) for the prevention of CRBSI. The novel finding of this observational study was that there was a higher incidence of CRBSI in the catheterization of jugular vein by posterior access in patients with tracheostomy than without it (13.24 vs 0 episodes of CRBSI per 1,000 catheter-day; odds ratio = 23.92; 95% CI = 1.86-infinite; p = 0.008). Thus, the presence of tracheostomy is a risk factor of CRBSI on the catheterization of jugular vein by posterior access.

Effect of cow slurry amendment on atrazine dissipation and bacterial community structure in an agricultural Andisol.

Atrazine is a commonly used herbicide for maize production in Chile, but it has recently been shown to be ineffective in soils that receive applications of cow slurries generated from the dairy industry. This effect may be caused either by the sorption of the pesticide to organic matter or more rapid degradation in slurry-amended soils. The objectives of this study were to evaluate the effects of cow slurry on atrazine dissipation, the formation of atrazine metabolites and the modification of bacterial community in Andisol. The cow slurry was applied at doses of 100,000-300,000 Lha(-1). After 4 weeks, atrazine was applied to the slurry-amended soils at concentrations of 1-3 mg kg(-1). The amounts of atrazine and its metabolites were determined by high performance liquid chromatography (HPLC). The soil microbial community was monitored by measurement of CO(2) evolution and changes in bacterial community using PCR-DGGE of 16S rRNA genes. The results show that cow slurry applications had no effect on atrazine dissipation, which had a half-life of 15-19 days. The atrazine metabolites were detected after 20 days and were significantly higher in soils amended with the slurry at both 20 and 40 days after application of the herbicide. Respiration rates were elevated after 10 days in all soils with atrazine addition. Both the atrazine and slurry amendments altered the bacterial community structures, indicated by the appearance of specific bands in the DGGE gels after 10 days. Cloning and sequencing of the 16S rRNA genes from the DGGE gels showed that the bands represented various genera of beta-proteobacteria that appeared in response to atrazine. According to our results, further field studies are required to explain the lower effectiveness of atrazine in weed control. These studies may include the effect of dissolved organic carbon on the atrazine mobility.

Kinetic and thermodynamic study of chlorophenol sorption in an allophanic soil.

The sorption of 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol by a allophanic soil was studied in a series of batch experiments. Chlorophenol sorption behavior was evaluated as a function of reaction time (0-96h) and input concentration at a fixed ionic strength (0.1mol L(-1) KCl) at 25, 35, and 45 degrees C. Sorption results for the various reaction temperatures were used in calculating thermodynamic parameters. Chlorophenol sorption increased with temperature, suggesting an endothermic process. The Elovich equation was used to describe the kinetic data. Data from the isotherm experiments were described by the Triple-Layer Model in which monodentate outer- and inner-sphere complexes were formed between deprotonated organic molecules and active sites on the variable-charge soil. The calculated thermodynamic parameters suggest that chlorophenol sorption is a spontaneous (DeltaG<0), endothermic (DeltaH>0) and entropy-driven reaction (DeltaS>0).