1,210 research outputs found

    High resolution forecasts of wind in rough orography and in coastal conditions

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    The increase of the share of wind energy in total electrical power requires the development of reliable forecasts of wind power at different time scales, from minutes to days, on a regional and national basis. That development is multidisciplinary, involving meteorological and engineering components. In the present stage, though, it is thought that for time scales beyond 3 hours, the largest improvements are expected from the meteorological side, if meteorological forecasts are able to deal with mesoscale flow. In this paper three case studies of mesoscale modeling are analyzed and compared against wind observations in sites selected for their high potential for wind energy. Two cases deal with flow in the Islands of Madeira and San Jorge (Azores), characterized by rough orography, where measurements were made at the top of elevated plateaus. In these two cases, the large scale flow is obtained from ECMWF analysis and the mesoscale flow is computed, for one summer and one winter month, with two mesoscale models at resolutions between 6 and 0.5 km. In the third case, one full year of simulationis Continental Portugal is performed at resolutions between 27 and 3km, using boundary conditions from the NCEP/NCAR reanalysis and the MM5 model. Results indicate the interest of high horizontal resolution for wind forecasts in complex terrain but also some difficulties in the representation of boundary layer effects in conditions of large thermal forcing.

    Removal of the Antibiotic Sulfamethoxazole by “Green” Clay Sorbents

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    Contamination of water resources with pharmaceuticals has been one of the top concerns of environmental sciences in the latest years [1, 2], the matter having received very significant media coverage recently [2, 3]. Antibiotics in particular have been gathering considerable attention and are amongst the most serious worries due to the development of antibiotic resistant bacteria as result of prolonged exposure [1, 2, 3]. In particular, antimicrobials and their metabolites are being detected in significant amounts in water supplies, and although no evidence exists that human health is affected by minute doses of antibiotics over long periods of time, changes have been observed in ecosystem functions [3,4]. In addition to antimicrobial resistance, other effects have been observed such as a delay in cell growth of bacteria, limited denitrification, and shifts in community composition [5]. Sulfamethoxazole (SMX), a broad-spectrum biostatic sulfanilamide, has become a point of interest because of its prevalence in contaminated wastewaters at concentrations correlated to bacterial resistance and genetic mutations in organisms [3,4,5]. Taking into account the widespread use of sulfonamides and their potential environmental effects, there is importance in developing new technologies for removing SMX and similar compounds from points of discharge. In fact, most wastewater treatment plants are inefficient for the removal of most micropollutants, especially hardly biodegradable organic xenobiotics which are present in wastewaters at low concentrations, as these conventional systems were only designed for removing bulk pollutants. Several advanced technologies have been evaluated as options to treat these contaminants, e.g. advanced oxidative processes or membrane filtration, but despite the sometimes high removal efficiencies attained, these technologies are too expensive to be considered as viable solutions on a large scale. Adsorption, alone or as part of a more complex water or wastewater treatment process, has been seen as playing a very important role in the removal of many organic xenobiotic pollutants [6, 7]. In this regard, the choice of adsorbent materials is crucial. However, pollutants removal efficiency is not the sole selection criterion, as the cost of the materials may provide or preclude economic viability of the water/wastewater treatment system. Therefore, the quest for efficient adsorbents that are widely available, and do not require expensive processing in order to be used (thereby allowing lower production costs) is a very important aspect of research aimed to manage this environmental problem. In this work we present the study of sorption properties of clay materials (LECA and vermiculite) for the removal of SMX from water. The dependence of removal efficiencies on the antibiotic initial concentrations, contact time with the adsorbents and other system/environment conditions was assessed. The two clay materials were compared in terms of their more balanced performance towards the removal of the pharmaceutical tested and the materials are suggested as a useful component of a water or wastewater treatment system designed for the removal of this contaminant (and others of similar type). Vermiculite was shown to be more efficient than LECA in the adsorption of the pharmaceutical and the one with faster kinetics. In other to gain a deeper insight into the characteristics that favor the removal of this compound by mineral surfaces, quantum chemical theoretical calculations were performed to illustrate the type of interactions that are responsible for the preferable adsorption of the compound to the vermiculite surface

    The Role Of Videolaparoscopy In The Diagnostic And Therapeutic Approach Of Nonpalpable Testis.

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    Evaluate the results from the first 5 years of experience with laparoscopy for diagnosis and treatment of nonpalpable testes. Medical records of 51 patients submitted to laparoscopic testicular exploration, during a 5-year period, were retrospectively analyzed. Patients' mean age was 65.7 months (median = 48) on the first procedure. The youngest patient was 10 months and the oldest was 14 years old on the first surgery. Twenty-four (47%) patients presented nonpalpable testes bilaterally, 7 (14%) only at the right side and 20 (39%) at the left, totaling 75 testicular units assessed. Patients who had their testes palpated after anesthetic induction were excluded from the study, and in all other cases, surgical management was based on the testicular position and viability. During the post-operative follow-up, surgical success was classified as palpable testis in scrotal sac, with adequate consistency and volume. Nine (12%) testes were not localized, but their vessels and deferent duct were atrophic. Two (3%) testes were intra-abdominal and atrophic, and 2 (3%) gonads, in the same patient, had a dysmorphic aspect. Nineteen (25%) testicular units were located close to the internal inguinal ring (peeping testes) and, in 22 (29%) units, the spermatic vessels and deferent duct penetrated the internal inguinal ring. Eight (10%) testes were located at a distance of less than 2 cm from the internal inguinal ring and 13 (17%) at a distance greater than 2 cm. The 2 intra-abdominal atrophic testes were removed. Inguinotomy was performed in a total of 41 (54%) cases, reaching a surgical success of 89%. Laparoscopic orchiopexy in one stage, without vascular ligation, was performed in 9 (12%) testes, which presented a distance of less than 2 cm from the internal inguinal ring, also with a surgical success index of 89%. Orchiopexy in 2 stages, with ligation of the spermatic vessels, was performed in 13 (17%) testicular units located at a distance greater than 2 cm from the internal inguinal ring, reaching 77% of good results. Videolaparoscopy is a safe and effective method for diagnosis and treatment of nonpalpable testis.29345-51; discussion 351-

    Effect of a pparγ synthetic agonist associated with retinoic acid on 24-hour rhythms in the hippocampus of an experimental model of Alzheimer’s disease

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    Alzheimer's disease (AD) is the most frequent cause of dementia in the older adults. The main pathogenic mechanism in sporadic AD is the decreasein amyloid beta peptide (Aβ) clearance. It is known that Apolipoprotein E (Apo E) modulates Aβ deposition and clearance. ApoE expression istranscriptionally induced by PPARγ in coordination with RXRs. Previously, we found that an intracerebroventricular injection of Aβ(1-42) modifiedthe daily rhythms of Apo E, Bmal 1, and Aβ in the rat hippocampus. Taking into account those observations, the objective of this work was toinvestigate the effects of synthetic PPARγ agonist, pioglitazone, and retinoic acid (Pio-RA) on the 24-h rhythms of Apo E, BMAL1 and Aβ proteinlevels, as well as on the daily rhythms of brain-derived neurotrophic factor (Bdnf) and its receptor (TrkB) expression in the rat hippocampus. In thisstudy, male Holtzman rats from control, Aβ-injected (Aβ) and Aβ-injected treated with Pio-RA groups were euthanized throughout a 24-h period andhippocampus samples were isolated every 6 h. Apo E, BMAL1 and Aβ proteins levels were analyzed by immunoblotting and Bdnf and TrkB mRNAlevels were determined by RT-PCR. Regulatory regions of Apo E and clock genes were scanned for E-box, RORE, RXRE and PPRE sites. Weobserved that the treatment of Pio-RA reestablished the daily rhythms of Apo E, Aβ, BMAL1 protein, and Bdnf mRNA levels. This treatment alsoincreased Bdnf and TrkB levels. We found E-box, RXRE, and PPRE sites on regulatory regions of Apo E and Bmal1 genes. The results of thepresent study could suggest that the treatment of Pio-RA would not only restore the altered rhythmic patterns of the clock genes and their target genesobserved in animals injected with Aβ aggregates, but also, interestingly, would increase the levels of cognition-related genes, which are decreased inAlzheimer's patients.Fil: Castro, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Mazaferro, P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Golini, Rebeca Laura Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Navigatore Fonzo, Lorena Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Anzulovich Miranda, Ana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaXXXVII Annual Scientific Meeting of the Tucumán Biology Association XXIII Annual Scientific Meeting of the Córdoba Biology Society XXXVIII Annual Scientific Meeting of the Cuyo Biology Society Argentine Biology SocietyArgentinaSociedades de Biología de la República Argentin

    Monocarboxylate transport inhibition potentiates the cytotoxic effect of 5-fluorouracil in colorectal cancer cells

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    Cancer cells rely mostly on glycolysis to meet their energetic demands, producing large amounts of lactate that are extruded to the tumour microenvironment by monocarboxylate transporters (MCTs). The role of MCTs in the survival of colorectal cancer (CRC) cells is scarce and poorly understood. In this study, we aimed to better understand this issue and exploit these transporters as novel therapeutic targets alone or in combination with the CRC classical chemotherapeutic drug 5-Fluorouracil. For that purpose, we characterized the effects of MCT activity inhibition in normal and CRC derived cell lines and assessed the effect of MCT inhibition in combination with 5-FU. Here, we demonstrated that MCT inhibition using CHC (a-cyano-4-hydroxycinnamic acid), DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid) and quercetin decreased cell viability, disrupted the glycolytic phenotype, inhibited proliferation and enhanced cell death in CRC cells. These results were confirmed by specific inhibition of MCT1/4 by RNA interference. Notably, we showed that 5-FU cytotoxicity was potentiated by lactate transport inhibition in CRC cells, either by activity inhibition or expression silencing. These findings provide novel evidence for the pivotal role of MCTs in CRC maintenance and survival, as well as for the use of these transporters as potential new therapeutic targets in combination with CRC conventional therapy.Ricardo Amorim was recipient of the fellowships SFRH/BI/51118/ 2010 and SFRH/BD/98002/2013, from Fundação para a Ciência e Tecnologia (FCT, Portugal). This study was supported by the FCT grant ref. PTDC/SAU-FCF/104347/2008, under the scope of “Programa Operacional Temático Factores de Competitividade” (COMPETE) of “Quadro Comunitário de Apoio III” and co-financed by Fundo Comunitário Europeu FEDER. This work was also supported by FEDER through POFC – COMPETE and by FCT through project PEst-OE/BIA/UI4050/2014 and Helena Pereira’s fellowship (SFRH/BD/73139/2010)

    Estudo preliminar da actividade antimicrobiana das folhas de cydonia oblonga miller

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    O marmelo é reconhecido como uma importante fonte de compostos promotores da saúde sendo que a actividade antimicrobiana dos extractos da sua polpa, casca e sementes foi já avaliada. Não existem porém estudos da actividade antimicrobiana das folhas de marmeleiro. Este estudo preliminar teve como objectivo determinar a actividade dos seus extractos metanólicos. Concluiu-se que os extractos testados não apresentam actividade em E. coli, S. aureus, C. albicans, C. glabrata, A. niger, A. fumigatus, Mucor spp e Absídia spp pelo que novos extractos devem ser preparados sendo posteriormente avaliados. Quince fruit is recognized an important source of health promoting compounds being the antimicrobial activities of the quince pulp, peel grape and seed extracts already evaluated. No results are known for quince leaves antimicrobial activity. This preliminary work intended to determine the activity of quince leaves methanolic extracts. These had no antimicrobial activity either against E. coli, S. aureus, C. albicans, C. glabrata, A. niger, A. fumigatus, Mucor spp e Absídia spp and new extracts must be prepared and evaluated

    A Critical Perspective on 3D Liver Models for Drug Metabolism and Toxicology Studies

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    The poor predictability of human liver toxicity is still causing high attrition rates of drug candidates in the pharmaceutical industry at the non-clinical, clinical, and post-marketing authorization stages. This is in part caused by animal models that fail to predict various human adverse drug reactions (ADRs), resulting in undetected hepatotoxicity at the non-clinical phase of drug development. In an effort to increase the prediction of human hepatotoxicity, different approaches to enhance the physiological relevance of hepatic in vitro systems are being pursued. Three-dimensional (3D) or microfluidic technologies allow to better recapitulate hepatocyte organization and cell-matrix contacts, to include additional cell types, to incorporate fluid flow and to create gradients of oxygen and nutrients, which have led to improved differentiated cell phenotype and functionality. This comprehensive review addresses the drug-induced hepatotoxicity mechanisms and the currently available 3D liver in vitro models, their characteristics, as well as their advantages and limitations for human hepatotoxicity assessment. In addition, since toxic responses are greatly dependent on the culture model, a comparative analysis of the toxicity studies performed using two-dimensional (2D) and 3D in vitro strategies with recognized hepatotoxic compounds, such as paracetamol, diclofenac, and troglitazone is performed, further highlighting the need for harmonization of the respective characterization methods. Finally, taking a step forward, we propose a roadmap for the assessment of drugs hepatotoxicity based on fully characterized fit-for-purpose in vitro models, taking advantage of the best of each model, which will ultimately contribute to more informed decision-making in the drug development and risk assessment fields.This research has been supported by FCT (Portugal) through the research grants and scholarship PTDC/MED-TOX/29183/2017, UIDB/04138/2020, UIDP/04138/2020, and SFRH/BD/144130/2019 to JR and by the H2020, European Commission, though the MSCA-IF-EF-ST – Standard EF to MC (GA-845147-LIV-AD-ON-A-CHIP). Conflict of Interestinfo:eu-repo/semantics/publishedVersio
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