608 research outputs found
Redox transformations of adsorbed NO molecules on a Pt(100) electrode
The electrochemical behavior of adsorbed NO molecules on a Pt(100) electrode has been studied in perchloric acid solutions by means of cyclic voltammetry. According to the literature data, a saturated NO adlayer with a coverage of ∼0.5 monolayers (MLs) is formed under open circuit conditions in an acidic nitrite solution as a result of a disproportionation reaction. The saturated adlayer is stable in the potential range of 0.4–0.9 V vs. a reversible hydrogen electrode in 0.1 M HClO4. NO molecules are oxidized at 0.9–1.1 V with the formation of adsorbed nitrite anions, and they can be reduced to ammonia at potentials less than 0.4 V. In this paper it has been shown that the adlayer stability depends on the surface coverage and extent of ordering. An unsaturated NO adlayer demonstrates NO ↔ NH3 redox transformations at 0.5–0.8 V.Financial support from the Russian Foundation for Basic Research (project no. 10-03-00427), MICINN (CTR2010-1624)(Feder), and Generalitat Valenciana (Prometeo/2009/045)(Feder, Spain) is gratefully acknowledged
A Palatable Hyperlipidic Diet Causes Obesity and Affects Brain Glucose Metabolism in Rats
Background
We have previously shown that either the continuous intake of a palatable hyperlipidic diet (H) or the alternation of chow (C) and an H diet (CH regimen) induced obesity in rats. Here, we investigated whether the time of the start and duration of these feeding regimens are relevant and whether they affect brain glucose metabolism.
Methods
Male Wistar rats received C, H, or CH diets during various periods of their life spans: days 30-60, days 30-90, or days 60-90. Experiments were performed the 60th or the 90th day of life. Rats were killed by decapitation. The glucose, insulin, leptin plasma concentration, and lipid content of the carcasses were determined. The brain was sliced and incubated with or without insulin for the analysis of glucose uptake, oxidation, and the conversion of [1-14C]-glucose to lipids.
Results
The relative carcass lipid content increased in all of the H and CH groups, and the H30-60 and H30-90 groups had the highest levels. Groups H30-60, H30-90, CH30-60, and CH30-90 exhibited a higher serum glucose level. Serum leptin increased in all H groups and in the CH60-90 and CH30-90 groups. Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups. Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group. The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups.
Conclusion
These findings indicate that both H and CH diet regimens increased body adiposity independent treatment and the age at which treatment was started, whereas these diets caused hyperglycemia and affected brain metabolism when started at an early age
Contraintes a l’adoption de la methode de l’hygiene sanitaire des vergers pour la lutte contre les mouches nuisibles aux fruits (Diptera, Tephritidae) par les producteurs de mangues et d’agrumes au Benin
No AbstractMots-clés: Bénin, hygiène sanitaire des vergers, mouches de fruits, producteurs de mangues et d’agrumes
Impacts of climate changes on risk zoning for cowpea in the Amazonian tropical conditions
The climate risk zoning was carried out for cowpea cultivated in northeastern Amazonia, Pará state, Brazil. Système d’Analyse
Régionale des Risques Agroclimatologiques (SARRA) crop model was used and calibrated from data obtained in field experiments
conducted between 2013 and 2016 in Castanhal, state of Pará. Low climate risk areas were defined as those with water requirement
satisfaction index (WRSI) greater than or equal to 0.5 during flowering and early grain development and less than 20 mm of total rainfall
during grain maturation and harvest for at least 80% of the simulated sowings of the crop. Simulations of the current and future climate
conditions were carried out with the regional climate modelling system version 4 (RegCM4) nested with the HadGEM2 global circulation
model with RCP 4.5 IPCC-AR4 scenario. The results show that climate changes are likely to reduce the duration of the optimal period for
sowing cowpea in the mentioned regioninfo:eu-repo/semantics/publishedVersio
Low-density Lipoprotein Cholesterol And Radiotherapy-induced Carotid Atherosclerosis In Subjects With Head And Neck Cancer
Background: Radiotherapy (RT) is a risk factor for accelerated carotid artery atherosclerotic disease in subjects with head and neck cancer. However, the risk factors of RT-induced carotid artery remodeling are not established. This study aimed to investigate the effects of RT on carotid and popliteal arteries in subjects with head and neck cancer and to evaluate the relationship between baseline clinical and laboratory features and the progression of RT-induced atherosclerosis.Findings: Eleven men (age = 57.9 ± 6.2years) with head and neck cancer who underwent cervical bilateral irradiation were prospectively examined by clinical and laboratory analysis and by carotid and popliteal ultrasound before and after treatment (mean interval between the end of RT and the post-RT assessment = 181 ± 47 days). No studied subject used hypocholesterolemic medications. Significant increases in carotid intima-media thickness (IMT) (0.95 ± 0.08 vs. 0.87 ± 0.05 mm; p 3.0.CO;2-X, 626923Pereira Lima, M.N., Biolo, A., Foppa, M., da Rosa, P.R., Rohde, L.E., Clausell, N., A prospective, comparative study on the early effects of local and remote radiation therapy on carotid intima-media thickness and vascular cellular adhesion molecule-1 in patients with head and neck and prostate tumors (2011) Radiother Oncol, 101, pp. 449-453. , 10.1016/j.radonc.2010.03.026, 20435360Kalábová, H., Melichar, B., Ungermann, L., Doležal, J., Krčmová, L., Kašparová, M., Plíšek, J., Solichová, D., Intima-media thickness, myocardial perfusion and laboratory risk factors of atherosclerosis in patients with breast cancer treated with anthracycline-based chemotherapy (2011) Med Oncol, 28, pp. 1281-1287. , 10.1007/s12032-010-9593-1, 20567943Muzaffar, K., Collins, S.L., Labropoulos, N., Baker, W.H., A prospective study of the effects of irradiation on the carotid artery (2000) Laryngoscope, 110, pp. 1811-1814. , 10.1097/00005537-200011000-00007, 11081590Faruolo, M., Fiorentino, A., Gallucci, G., Lapadula, L., Fusco, V., Intimal-medial thickness and carotid arteries lumen in irradiated patients for head and neck cancer: preliminary data of an observational study (2013) Clin Transl Oncol, 15, pp. 861-864. , 10.1007/s12094-013-1023-3, 23463595Ferreira-Sae, M.C., Cipolli, J.A., Cornélio, M.E., Matos-Souza, J.R., Fernandes, M.N., Schreiber, R., Costa, F.O., Nadruz, W., Sodium intake is associated with carotid artery structure alterations and plasma matrix metalloproteinase-9 upregulation in hypertensive adults (2011) J Nutr, 141, pp. 877-882. , 10.3945/jn.110.135921, 21430243Gemignani, T., Azevedo, R.C., Higa, C.M., Coelho, O.R., Matos-Souza, J.R., Nadruz, W., Increased popliteal circumferential wall tension induced by orthostatic body posture is associated with local atherosclerotic plaques (2012) Atherosclerosis, 224, pp. 118-122. , 10.1016/j.atherosclerosis.2012.06.069, 2281862
The Milky Way Bulge: Observed properties and a comparison to external galaxies
The Milky Way bulge offers a unique opportunity to investigate in detail the
role that different processes such as dynamical instabilities, hierarchical
merging, and dissipational collapse may have played in the history of the
Galaxy formation and evolution based on its resolved stellar population
properties. Large observation programmes and surveys of the bulge are providing
for the first time a look into the global view of the Milky Way bulge that can
be compared with the bulges of other galaxies, and be used as a template for
detailed comparison with models. The Milky Way has been shown to have a
box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an
additional spheroidal component. In this review we summarise the global
chemical abundances, kinematics and structural properties that allow us to
disentangle these multiple components and provide constraints to understand
their origin. The investigation of both detailed and global properties of the
bulge now provide us with the opportunity to characterise the bulge as observed
in models, and to place the mixed component bulge scenario in the general
context of external galaxies. When writing this review, we considered the
perspectives of researchers working with the Milky Way and researchers working
with external galaxies. It is an attempt to approach both communities for a
fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure
Expanded Bed Adsorption Of Bromelain (e.c. 3.4.22.33) From Ananas Comosus Crude Extract
This work focuses on the adsorption of Bromelain in expanded bed conditions, such as the adsorption kinetics parameters. The adsorption kinetics parameters showed that after 40 minutes equilibrium was achieved and maximum adsorption capacity was 6.11 U per resin mL. However, the maximum adsorption capacity was only determined by measuring the adsorption isotherm. Only by the Langmuir model the maximum adsorption capacity, Qm, and dissociation constant, kd, values could be estimated as 9.18 U/mL and 0.591, respectively, at 25°C and 0.1 mol/L phosphate buffer pH 7.5. A column made of glass with an inner diameter of 1 cm was used for the expanded bed adsorption (EBA). The residence time was reduced 10 fold by increasing the expansion degree 2.5 times; nonetheless, the plate number (N) value was reduced only 2 fold. After adsorption, the bromelain was eluted in packed bed mode, with a downward flow. The purification factor was about 13 fold and the total protein was reduced 4 fold. 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Analysis of the impact of watershed management practices, vegetation, and land use on soil erosion using EPM-IntErO modelling in Ceará’s semi-arid region
The semi-arid region of Ceará, located in Northeast Brazil, is typically characterized by low rainfall, high temperatures, and sparse vegetation – conditions generally associated with reduced soil erosion rates. However, the region's fragile soils, which are shallow, nutrient-poor, and particularly susceptible to degradation, exacerbate the erosion. This degradation poses a significant threat to soil fertility, agricultural productivity, and environmental sustainability in the area. The primary objective of this study was to quantify soil loss in Ceará and to challenge the prevailing assumption that semi-arid regions inherently experience minimal erosion due to limited rainfall. The Intensity of Erosion and Outflow (IntErO) model was used, in conjunction with remote sensing data and geographic information system (GIS) technologies. Through this approach, we estimated an average soil loss rate of 9.7 Mg ha⁻¹ yr⁻¹. The results indicate that 38% of Ceará’s land area experiences soil loss rates exceeding tolerance limits, particularly in regions lacking vegetation, as well as in agricultural lands and pastures. These elevated erosion rates are largely attributed to the area’s poor soil properties, occasional intense rainfall events, and unsustainable land management practices. The findings underscore the urgent need for improved management of soil erosion processes to address these challenges. Implementing targeted soil conservation strategies and policies that promote sustainable land use is essential for mitigating water erosion, safeguarding long-term agricultural productivity, and enhancing environmental and socioeconomic sustainability in semi-arid regions
Reference intervals for metabolic profile of adult sheep in the tropics: over 12 months
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de Viçosa, MGUniversidade Federal de Uberlândia, MGUniversidade Estadual Paulista Júlio de Mesquita Filho, SPUniversidade Federal de Tocantins, TOUniversidade Estadual Paulista Júlio de Mesquita Filho, S
A Novel Hybrid Feature Selection Algorithm for Hierarchical Classification
Feature selection is a widespread preprocessing step in the data mining field. One of its purposes is to reduce the number of original dataset features to improve a predictive model’s performance. Despite the benefits of feature selection for the classification task, to the best of our knowledge, few studies in the literature address feature selection for the hierarchical classification context. This paper proposes a novel feature selection method based on the general variable neighborhood search metaheuristic, combining a filter and a wrapper step, wherein a global model hierarchical classifier evaluates feature subsets. We used twelve datasets from the proteins and images domains to perform computational experiments to validate the effect of the proposed algorithm on classification performance when using two global hierarchical classifiers proposed in the literature. Statistical tests showed that using our method for feature selection led to predictive performances that were consistently better than or equivalent to that obtained by using all features with the benefit of reducing the number of features needed, which justifies its efficiency for the hierarchical classification scenario
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