Elsevier - Publisher Connector
Not a member yet
1978752 research outputs found
Sort by
Novel solvothermal synthesis and characterization of Ag2S/PbSO4 nanocomposites
No full textAbstractNovel Ag2S/PbSO4 nanocomposites have been successfully synthesized by solvothermal process in propylene glycol as solvent. In this study, sodium dodecyl sulfate (SDS) was applied not only as a surfactant, but also as a sulfur source to produce Ag2S/PbSO4. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and energy dispersive spectroscopy (EDS). The absorption and photoluminescence study of the Ag2S/PbSO4 nanocomposite showed quantum confinement behavior with band gap of 3.1eV. Moreover, effects of reaction time on the morphology and particle sizes of the final products have been investigated by SEM images
Resección total del mesorrecto por vía transanal en cáncer de recto. Análisis de resultados de una serie preliminar en un hospital universitario
No full textResumenIntroducciónLa resección total del mesorrecto por vía transanal es un abordaje híbrido que combina el uso de una plataforma transanal y laparoscopia convencional.ObjetivosRealizar el análisis de casos seleccionados con cáncer de recto medio e inferior en los cuales se utilizó un abordaje transanal combinado para su resolución y la descripción de la técnica quirúrgica.Materiales y métodosCorresponde a una serie prospectiva de pacientes con diagnóstico de cáncer de recto de tercio medio e inferior con resección mesorrectal asistida por monopuerto endoanal entre octubre de 2012 y diciembre de 2015, en Hospital Clínico Universidad de Chile. Se utilizó estadística descriptiva para el análisis de los datos.ResultadosFueron sometidos a cirugía por cáncer de recto medio e inferior un total de 29 pacientes utilizando monopuerto transanal. De estos, 22 fueron de sexo masculino y 7 de sexo femenino, con edad promedio de 55,5 años e IMC de 26,4. La distancia media al margen anal fue 4,8cm. Todos recibieron neoadyuvancia. Se realizaron 17 Ta-TME (58,6%) y 12 Ta-TME con abordaje interesfintérico (41,4%). La anastomosis fue coloanal manual en 15 pacientes (51,7%) y grapada en 14 (48,3%). El abordaje laparoscópico se utilizó en 26 pacientes y el abierto en 3, registrando 4 conversiones (15,4%). El tiempo operatorio promedio fue de 282min. La estadía hospitalaria media fue de 9 días.ConclusiónEl monopuerto endoanal aparece como una herramienta útil en la disección total del mesorrecto por su seguridad y factibilidad. Creemos que es necesaria la realización de trabajos prospectivos aleatorizados, donde es relevante la comparación de resultados oncológicos y funcionales a largo plazo.AbstractIntroductionTransanal total mesorectal excision is a hybrid approach that combines the use of a conventional laparoscopic and a transanal platform.ObjectivesTo conduct an analysis of selected cases with medium and lower rectal cancer, were a combined transanal approach was used and description of the surgical technique.Materials and methodsProspective series of patients diagnosed with middle and lower third rectal cancer with mesorectal resection assisted by endoanal single port, between October 2012 and December 2015 at University of Chile Clinical Hospital. Descriptive statistics were used for data analysis.ResultsA total of 29 patients underwent surgery for middle and lower rectal cancer using a transanal single port. Gender distribution was 22 male and 7 female patients, with a mean age of 55.5 years and a mean BMI of 26.4. The mean distance from the anal margin was 4.8cm. All patients received neoadjuvant therapy. The surgeries performed were 17 Ta-TME (58.6%) and 12 Ta-TME with intersphincteric approach (41.4%). The colo-anal anastomosis was hand sewn in 15 patients (51.7%), and stapled in 14 (48.3%). The laparoscopic approach was used in 26 patients and the open approach in 3, with 4 conversions (15.4%). The mean operative time was 282min. The mean hospital stay was 9 days.ConclusionThe endoanal single port appears as a useful tool in total mesorectal dissection for its safety and feasibility. We believe we need randomized prospective studies, where comparison of oncological and functional long-term results is relevant
Do green roofs cool the air?
No full textAbstractRapid urbanization and an increasing number and duration of heat waves poses a need to mitigate extremely high temperatures. One of the repeatedly suggested measures to moderate the so called urban heat island are green roofs. This study investigates several extensive sedum-covered green roofs in Utrecht (NL) and their effect on air temperature right above the roof surface. The air temperature was measured 15 and 30 cm above the roof surface and also in the substrate. We showed that under well-watered conditions, the air above the green roof, compared to the white gravel roof, was colder at night and warmer during the day. This suggests that extensive sedum-covered green roofs might help decrease air temperatures at night, when the urban heat island is strongest, but possibly contribute to high daytime temperatures. The average 24 h effect of sedum-covered green roof was a 0.2 °C increase of air temperature 15 cm above the ground. During a dry year the examined green roof exhibited behavior similar to conventional white gravel roof even exhibited slight cooling effect in late afternoon. Interestingly, the pattern of soil temperature remained almost the same for both dry and well-prospering green roofs, colder during the day and warmer at night
Visual cortex responses reflect temporal structure of continuous quasi-rhythmic sensory stimulation
No full textAbstractNeural processing of dynamic continuous visual input, and cognitive influences thereon, are frequently studied in paradigms employing strictly rhythmic stimulation. However, the temporal structure of natural stimuli is hardly ever fully rhythmic but possesses certain spectral bandwidths (e.g. lip movements in speech, gestures). Examining periodic brain responses elicited by strictly rhythmic stimulation might thus represent ideal, yet isolated cases. Here, we tested how the visual system reflects quasi-rhythmic stimulation with frequencies continuously varying within ranges of classical theta (4–7Hz), alpha (8–13Hz) and beta bands (14–20Hz) using EEG. Our findings substantiate a systematic and sustained neural phase-locking to stimulation in all three frequency ranges. Further, we found that allocation of spatial attention enhances EEG-stimulus locking to theta- and alpha-band stimulation. Our results bridge recent findings regarding phase locking (“entrainment”) to quasi-rhythmic visual input and “frequency-tagging” experiments employing strictly rhythmic stimulation. We propose that sustained EEG-stimulus locking can be considered as a continuous neural signature of processing dynamic sensory input in early visual cortices. Accordingly, EEG-stimulus locking serves to trace the temporal evolution of rhythmic as well as quasi-rhythmic visual input and is subject to attentional bias
Residential greenness and risk of prostate cancer: A case-control study in Montreal, Canada
No full textAbstractBackgroundRecent studies suggest that exposure to greenness favors several health outcomes. We assessed whether living in the proximity of greener areas was related to prostate cancer incidence in a population-based case-control study in Montreal, Canada.Materials and methodsInterviews eliciting lifetime addresses were conducted with 1933 prostate cancer cases diagnosed in 2005–2009 and 1994 population controls. Odds ratios (OR) and 95% confidence intervals (CI) estimated the association between residential greenness, both at recruitment (2005–2009) and about ten years prior (1996), defined by the normalized difference vegetation index (NDVI) around the home, and prostate cancer risk. Three models were developed adjusting for age, individual characteristics, and individual and ecological characteristics, estimating relative risk in relation to an interquartile range (IQR) increase of the NDVI.ResultsWe observed inverse associations between greenness measured within home buffers of 150m, 300m, 500m and 1000m, at both time points, and risk of prostate cancer, independently of individual and ecological characteristics. For instance, using a buffer of 300m, the OR for an IQR increase of 0.11 in NDVI at the time of recruitment was 0.82 (95%CI 0.74–0.92). The corresponding OR for an IQR increase of 0.15 in NDVI in 1996 was 0.86 (95%CI 0.74–1.00). There were little differences in risks according to buffer size, the time point of exposure, when considering prostate cancer aggressiveness, or when restricting controls to men recently screened for prostate cancer to reduce the likelihood of undiagnosed cancer among them.ConclusionMen living in greener areas, either recently or about a decade earlier, had lower risks of prostate cancer, independently of socio-demographic and lifestyle factors. These observations are novel and require confirmation
A review of toxic epidermal necrolysis management in Japan
No full textAbstractToxic epidermal necrolysis (TEN) is a severe adverse drug reaction characterized by necrosis of the epidermis. Its incidence is approximately 1 per million a year and average mortality rate is high at 25–50%. TEN has a flu-like prodrome, followed by atypical, targetoid erythematous or purpuric macules on the skin. These macules coalesce to form flaccid blisters that slough off as areas of epidermal necrosis. Drugs such as allopurinol, sulfonamides, and carbamazepine are the most common causes. The human leukocyte antigen (HLA)-B*15:02 in Asians being administered carbamazepine and the HLA-B*58:01 antigen in patients of all ethnicities being administered allopurinol are known to be high-risk factors. Rapid diagnosis, discontinuation of the causative drug, and supportive treatment are essential for better prognosis and improvement of sequelae. Till now, systemic corticosteroids and intravenous immunoglobulins have been used as the most common active interventions; however, no gold standard has been established. In Japan, physicians follow a unique diagnostic criteria and treatment guideline to improve the diagnosis rate and streamline treatments. This may be a contributing factor for the lower mortality rate (14.3%). The efficacy of systemic corticosteroids, immunoglobulins, and plasmapheresis may have been beneficial as well. In Japan, TEN is defined as an epidermal detachment of over 10% of the body surface area (BSA), while the globally accepted definition established by Bastuji-Garin describes it as an epidermal detachment of over 30% of the BSA. In Japanese individuals, HLA-A*02:06, HLA-A*02:07, HLA-A*31:01 and HLA-B*51:01 may be linked to higher risks of TEN
Evaluation of new oral anticoagulants in mild to moderate CKD patients with atrial fibrillation
No full textAnesthesia for pulmonary trunk aneurysmorrhaphy
No full textAbstractBackground and objectivesThe aneurysm in the pulmonary trunk is a rare disease. Because of its location, a rupture can lead to right ventricular failure and sudden death. Aneurysmorraphy is the most widely used surgical treatment in these cases. The aim of this study is to report a successful balanced general anesthesia for aneurysmorraphy of pulmonary trunk.Case reportMale patient, 28 years, asymptomatic, diagnosed with an aneurysm in the pulmonary trunk. According to the location of the aneurysm and the consequent failure of the pulmonary valve, an aneurysmorraphy was indicated, with implantation of vascular-valvular prosthesis (valved tube). We opted for a balanced general anesthesia, seeking to prevent an increase in systemic and pulmonary vascular resistances, thus avoiding to cause stress on the wall of the aneurysmal vessel.ConclusionsA balanced general anesthesia, in combination with adequate ventilation to prevent elevation in pulmonary vascular pressure, was appropriate for surgical repair of an aneurysm in the pulmonary trunk
Modeling of geogenic radon in Switzerland based on ordered logistic regression
No full textAbstractPurposeThe estimation of the radon hazard of a future construction site should ideally be based on the geogenic radon potential (GRP), since this estimate is free of anthropogenic influences and building characteristics. The goal of this study was to evaluate terrestrial gamma dose rate (TGD), geology, fault lines and topsoil permeability as predictors for the creation of a GRP map based on logistic regression.MethodSoil gas radon measurements (SRC) are more suited for the estimation of GRP than indoor radon measurements (IRC) since the former do not depend on ventilation and heating habits or building characteristics. However, SRC have only been measured at a few locations in Switzerland. In former studies a good correlation between spatial aggregates of IRC and SRC has been observed. That’s why we used IRC measurements aggregated on a 10 km × 10 km grid to calibrate an ordered logistic regression model for geogenic radon potential (GRP). As predictors we took into account terrestrial gamma doserate, regrouped geological units, fault line density and the permeability of the soil.ResultsThe classification success rate of the model results to 56% in case of the inclusion of all 4 predictor variables. Our results suggest that terrestrial gamma doserate and regrouped geological units are more suited to model GRP than fault line density and soil permeability.ConclusionOrdered logistic regression is a promising tool for the modeling of GRP maps due to its simplicity and fast computation time. Future studies should account for additional variables to improve the modeling of high radon hazard in the Jura Mountains of Switzerland
Treatment of post-traumatic elbow deformities in children with the Ilizarov distraction osteogenesis technique
No full textAbstractObjectiveThe present study assessed functional and radiographic outcomes of distraction osteogenesis treatment of post-traumatic elbow deformities in children.MethodsEight children were treated between 2008 and 2013 for post-traumatic elbow deformities using distraction osteogenesis. Mean age at time of operation was 10.9 years. Six patients had varus and 2 had valgus deformity. Magnitude of correction, fixator index, complications, carrying angle, and elbow range of motion were assessed. Functional results were graded according to protocol of Bellemore et al.ResultsMean follow-up was 43 months. Mean preoperative varus deformity in 6 patients was 29.2° and valgus deformity in 2 patients was 28.5°. Preoperative flexion and extension of elbow were 123.8° and −10.6°, respectively. Mean carrying angle was 9° valgus at last follow-up. Mean flexion and extension were 134.4° and −6.0°, respectively. Change in carrying angle was statistically significant (p = 0.002). There were 2 grade 1 pin tract infections and 1 diaphyseal fracture of humerus. Functional outcome was rated excellent in 7 patients and good in 1 patient.ConclusionIlizarov distraction osteogenesis is a valuable alternative in treatment of elbow deformities in children. The surgical technique is simple and correction is adjustable. Gradual correction prevents possible neurovascular complications and minimally invasive surgery produces less scarring. Compliance of patient and family is key factor in the success of the outcome.Level of evidenceLevel IV, therapeutic stud