6,340 research outputs found
Numerical Study of the Thermal Efficiency of a School Building with Complex Topology for Different Orientations
In this work a numerical model that simulates the thermal behavior of a building with complex topology and evaluates the indoor thermal and air quality, in transient conditions, is used for a school building thermal project. The program calculates the building surfaces solar radiation field, the building's temperatures, the internal environmental variables, and the occupant's comfort levels. Initially, after the numerical model is validated, the software is used to evaluate the school building's thermal response for four different orientations, either in winter or summer conditions. The work then aims to identify uncomfortable spaces in order to propose, as an example, several solutions that could be introduced for each orientation, that would improve the thermal comfort and air quality levels to which the occupants are subjected, and decrease the building's energy consumption levels. The information obtained from this study could be used to help a designer choose which thermal systems and solutions function best for a preferred school building orientation
Normal Brain Response to Propofol in Advance of Recovery from Unresponsive Wakefulness Syndrome
Up to 40% of individuals with unresponsive wakefulness syndrome (UWS) actually might be conscious. Recent attempts to detect covert consciousness in behaviorally unresponsive patients via neurophysiological patterns are limited by the need to compare data from brain-injured patients to healthy controls. In this report, we pilot an alternative within-subject approach by using propofol to perturb the brain state of a patient diagnosed with UWS. An auditory stimulation series was presented to the patient before, during, and after exposure to propofol while high-density EEG was recorded. Baseline analysis revealed residual markers in the continuous EEG and event-related potentials (ERPs) that have been associated with conscious processing. However, these markers were significantly distorted by the patient’s pathology, challenging the interpretation of their functional significance. Upon exposure to propofol, changes in EEG characteristics were similar to what is seen in healthy individuals and ERPs associated with conscious processing disappeared. At the one-month follow up, the patient had regained consciousness. We offer three alternative explanations for these results: 1) the patient was covertly consciousness, and was anesthetized by propofol administration; 2) the patient was unconscious, and the observed EEG changes were a propofol-specific phenomenon; 3) the patient was unconscious, but his brain networks responded normally in a way that heralded the possibility of recovery. These alternatives will be tested in a larger study, and raise the intriguing possibility of using a general anesthetic as a probe of brain states in behaviorally unresponsive patients
Probing hot gas around luminous red galaxies through the Sunyaev-Zel'dovich effect
We construct the mean thermal Sunyaev-Zel'dovich (tSZ) Comptonization y profile around Luminous Red Galaxies (LRGs) in the redshift range 0.16 < z < 0.47 from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) using the Planck y map. The mean central tSZ signal for the full sample is y ~ 1.8 * 10^(-7) and we detect tSZ emission out to ~30 arcmin, which is well beyond the 10 arcmin angular resolution of the y map and well beyond the virial radii of the LRGs. We compare the measured profile with predictions from the cosmo-OWLS suite of cosmological hydrodynamical simulations. This comparison agrees well for models that include feedback from active galactic nuclei (AGN), but not with hydrodynamic models without this energetic feedback mechanism. This suggests that an additional heating mechanism is required over SNe feedback and star formation to explain the y data profile. We also compare our results with predictions based on the halo model with a universal pressure profile (UPP) giving the y signal. The predicted profile is consistent with the data, but only if we account for the clustering of haloes via a two-halo term and if halo masses are estimated using the mean stellar-to-halo mass (SHM) relation of Coupon et al. (2015) or Wang et al.(2016) estimated from gravitational lensing measurements. We also discuss the importance of scatter in the SHM relation on the model predictions
Efficacy and tolerability of vigabatrin in West syndrome
West syndrome (WS) is a severe epileptic encephalopathy of childhood, characterized by spasms, developmental deterioration and hipsarhythymia. Objective: To evaluate the safety and efficacy of vigabatrin (VGB) in the treatment of WS. Method: We evaluated every patient diagnosed with WS seen at the pediatric epilepsy clinic and exposed to VGB. Patients were interviewed according to a semistructured questionnaire and we analyzed gender, age, etiology (cryptogenic or symptomatic), associated diseases, age of seizure onset, neuroimaging findings, EEG prior and after VGB, use of other antiepileptic drugs, time for seizure control, electroretinogram, visual complaints, adverse events and family history of epilepsy. Results: Twenty-three patients were evaluated, 16 boys, ages ranging from 1.25 years to 11.5 years (mean=5y3m). Sixteen (69.5%) patients were seizure free, five (22%) had partial seizure control and in two (8.5%) there was no improvement. Only one patient presented gabaergic retinopathy. Six (26%) patients presented adverse events: somnolence, aggressivity or retinopathy. Patients with seizure onset after 6 months of age presented better results after VGB introduction (p 0.05). After VGB, no patient presented hipsarrhythymia and 50% had a normal EEG. Conclusion: Although VGB may be associated with serious adverse events such as gabaergic retinopathy, our results show that it should be considered in the treatment of WS.632B46947
Ion release and local effects of titanium metal particles from dental implants: an experimental study in rats
Background: The objective of this study was to evaluate the accumulation of ions in blood and organs caused by Ti metal particles in a mandibular defect in rats, together with a description of the local reaction of oral tissues to these titanium alloy debris. Methods: Twenty Sprague-Dawley rats were randomly distributed into three groups: an experimental group with a mandibular bone defect filled with metallic debris obtained by implantoplasty; a positive control group; and a negative control group. Thirty days after surgery, the rats were euthanized and perilesional tissue surrounding the mandibular defect was removed, together with the lungs, spleen, liver and brain. Two blood samples were collected: immediately before surgery and before euthanasia. The perilesional tissue was histologically analyzed using hematoxylin-eosin staining, and titanium, aluminum and vanadium ion concentrations in blood and organs were measured by TQ-ICP-MS. Descriptive and bivariate analyses of the data were performed. Results: All rats with implanted metal debris showed metal particles and a bone fracture callus on the osseous defect. The metal particles were surrounded by a foreign body reaction characterized by the presence of histiocytes and multinucleated giant cells. The experimental group had a significant higher concentration of Ti ions in all studied organs except lung tissue (p < 0.05). In addition, there were more V ions in the brain in the experimental group (p = 0.008). Conclusions: Although further studies are required to confirm the clinical relevance of these results, Ti metal particles in the jaw might increase the concentration of metal ions in vital organs and induce a foreign body reaction. This article is protected by copyright. All rights reserved. Keywords: Ion release; Ti6Al4V; implantoplasty; metal particles; peri-implantitis; titanium
Nuclear receptors in vascular biology
Nuclear receptors sense a wide range of steroids and hormones (estrogens, progesterone, androgens, glucocorticoid, and mineralocorticoid), vitamins (A and D), lipid metabolites, carbohydrates, and xenobiotics. In response to these diverse but critically important mediators, nuclear receptors regulate the homeostatic control of lipids, carbohydrate, cholesterol, and xenobiotic drug metabolism, inflammation, cell differentiation and development, including vascular development. The nuclear receptor family is one of the most important groups of signaling molecules in the body and as such represent some of the most important established and emerging clinical and therapeutic targets. This review will highlight some of the recent trends in nuclear receptor biology related to vascular biology
Knowledge and perceptions of food sustainability in a Spanish university population
In 2015, the United Nations adopted the 2030 Agenda for Sustainable Development, with 17 Sustainable Development Goals (SDGs) at its core. Besides tackling climate change and the fight to reduce inequality, the SDG number 12 is specifically focused to develop strategies toward food sustainability. The aim of this study, aligned with SDG number 12, was to analyze the level of knowledge and perceptions of food sustainability in a university community from Spain. A descriptive cross-sectional study, based on an online questionnaire, was carried out between July and November 2021 with convenience sampling. The survey included 28 items and was distributed among students, teachers, researchers and administrative staff from a Spanish university. A total of 1,220 participants completed the survey. 70.4% of the respondents heard about the environmental impact of food and more than 50% were aware of the existence of the SDGs. The different aspects related to diet that concerned them the most were food waste, plastic usage, and environmental impact. They reported that a sustainable diet should be mainly based on local and seasonal products and with a low environmental impact as well as no or the minimum food waste. When asked if they were following a sustainable diet, 77% answered affirmatively. Moreover, the food groups more involved in a sustainable diet should be vegetables and fruits, olive oil, legumes, and whole grains. Regarding food waste, 60% of the surveyed population claimed to generate it at home, with the use of leftovers and planning shopping and meals being some of the most important domestic actions to avoid it. Further initiatives must be implemented to increase the level of knowledge as well as to raise the awareness on the importance to translate it into individual and collective actions that allow a shift toward more sustainable practices
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