Rn-222, Rn-220 and other dissolved gases in mineral waters of southeast Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of psychoactive substances in students at a public university

Introduction: The use of psychoactive substances by the student population has been the object of various studies in Brazil. Objective: To determine the prevalence of substance use among students. Methods: Quantitative study with a closed questionnaire based on standardized assessment instruments was developed. It consists of questions related to types of psychoactive substance use, abuse, frequency and duration of use, self-criticism regarding the use, consequences of use in relation to health, and misdemeanors committed under the influence of psychoactive substances. The sample included the participation of 268 students. A total of 183 (68.3%) questionnaires were analyzed, and only those with positive result for substance abuse at some point in life, the remainder, 85 (31%) questionnaires, had negative responses to psychoactive substances. Results: Students’ responses to the two years surveyed indicated that the first psychoactive substance used was alcohol (77.9%), followed by tobacco use (10.9%), and marijuana (7.6%). Of the students surveyed, 145 (79.2%) answered that still make use of psychoactive substances, and the current frequency of use varies from one or more times per week. When asked about the possibility of being or becoming drug addicts, 169 (92.3%) responded that they are not or will not become dependent. Conclusion: The results indicate the high rate of substance use among college students surveyed, and point to their contradiction to consider such psychoactive substances harmful to their health.

The influence of floc size and hydraulic detention time on the performance of a dissolved air flotation (DAF) pilot unit in the light of a mathematical model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nickel exposure promotes osmoregulatory disturbances in Oreochromis niloticus gills: histopathological and energy dispersive spectrometry analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of litter manipulation in a tropical Eucalyptus plantation on leaching of mineral nutrients, dissolved organic nitrogen and dissolved organic carbon

Although many studies have shown that soil solution chemistry can be a reliable indicator of biogeochemical cycling in forest ecosystems, the effects of litter manipulations on the fluxes of dissolved elements in gravitational soil solutions have rarely been investigated. We estimated the fluxes of NH4-N, NO3-N, K, Ca, Mg, Na, Cl, dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) over the first two years after re-planting Eucalyptus trees in the coastal area of Congo. Two treatments were replicated in two blocks after clear-cutting 7-year-old stands: in treatment R, all the litter above the mineral soil was removed before planting, and in a double slash (DS) treatment, the amount of harvest residues was doubled. The soil solutions were sampled down to a depth of 4 m and the water fluxes were estimated using the Hydrus 1D model parameterized from soil moisture measurements in 4 plots. Isotopic and spectroscopic analytical techniques were used to assess the changes in dissolved organic matter (DOM) properties throughout the transfer in the soil. The first year after planting, the fluxes of NH4-N, K, Ca, Mg, Na, Cl and DOC in the topsoil of the DS treatment were 2-5 times higher than in R, which showed that litter was a major source of dissolved nutrients. Nutrient fluxes in gravitational solutions decreased sharply in the second year after planting, irrespective of the soil depth, as a result of intense nutrient uptake by Eucalyptus trees. Losses of dissolved nutrients were noticeably low in these Eucalyptus plantations despite a low cation exchange capacity, a coarse soil texture and large amounts of harvest residues left on-site at the clear cut in the DS treatment. All together, these results clarified the strong effect of litter manipulation observed on eucalypt growth in Congolese sandy soils. DOM fluxes, as well as changes in delta C-13, C:N and aromaticity of DOM throughout the soil profile showed that the organic compounds produced in the litter layer were mainly consumed by microorganisms or retained in the topsoil. Below a depth of 15 cm, most of the DOC and the DON originated from the first 2 cm of the soil and the exchanges between soil solutions and soil organic matter were low. (C) 2014 Elsevier B.V. All rights reserved.

Dissolved uranium, radium and radon evolution in the Continental Intercalaire aquifer, Algeria and Tunisia

Natural, dissolved U-238-series radionuclides (U, Ra-226, Rn-222) and activity ratios (A.R.s: U-234/U-238; Ra-228/Ra-226) in Continental Intercalaire (Cl) groundwaters and limited samples from the overlying Complexe Terminal (CT) aquifers of Algeria and Tunisia are discussed alongside core measurements for U/Th (and K) in the contexts of radiological water quality, geochemical controls in the aquifer, and water residence times. A redox barrier is characterised downgradient in the Algerian Cl for which a trend of increasing U-234/U-238 A.R.s with decreasing U-contents due to recoil-dominated U-234 solution under reducing conditions allows residence time modelling similar to 500 ka for the highest enhanced A.R. = 3.17. Geochemical modelling therefore identifies waters towards the centre of the Grand Erg Oriental basin as palaeowaters in line with reported C-14 and Cl-36 ages. A similar U-234/U-238 trend is evidenced in a few of the Tunisian CI waters. The paleoage status of these waters is affirmed by both noble gas recharge temperatures and simple modelling of dissolved, radiogenic He-4-contents both for sampled Algerian and Tunisian CI and CT waters. For the regions studied these waters therefore should be regarded as "fossil" waters and treated effectively as a non-renewable resource. (C) 2014 The Authors. Published by Elsevier Ltd.

Análise morfológica de brânquias de peixes Oreochromis niloticus (tilápia) expostos ao níquel

Water is an essential factor in maintaining the vital functions of living beings. We have observed a growing commitment of quality, are due to pollution from many sources and even entire watersheds, whether for industrial waste, sewage, or for substances used in farming such as pesticides, herbicides and fertilizers. Nickel is the 24th most abundant element on earth, is a heavy metal that, in the form of chloride, is a proven genotoxic and mutagenic. Due to its industrial use, there was considerable increase of its concentration in surface sediments. Fish combine characteristics that make them excellent experimental models for aquatic toxicology studies, which are particularly usable as warn about the potential danger of chemicals or the possibility of environmental pollution. Due to impaired water quality and the few published studies relating the nickel with the tissue change, this study aimed at assessing the consequences of the presence of nickel in the aquatic environment. For this analysis, we used individuals of Oreochromis niloticus, exposed for 96 hours at three different concentrations of nickel dissolved in water compared to a control group. After exposure, the gills were removed and these were analyzed by ultramorphological, histological and histochemical analysis. The results indicate that all concentrations used in the experiment altered the histophysiology of exposed individuals. We observed the following changes: rupture of paviment cells, thus resulting in bleeding, loss of microridges surface of these cells and epithelial loss in the gills of all animals in all treatments with nickel chloride, the histochemical analysis showed non-proliferation of chloride cells. However, there was a dose-dependent increase of mucus cells in all animals. Therefore, nickel has toxic potential to fish, from the smallest concentration used up to twice as permitted by law, indicating... (Complete abstract click electronic access below)

Use of HEPG2 cells to assay the safety of cosmetic active substances

The importance of this study is based on the need to obtain simple and efficient in vitro models to predict the in vivo toxicity of cosmetics, aiming not to use animals as experimental model. Here, we proposed the use of HepG2 cells, which are widely applied to simulate the hepatic function of the human organism in vitro. This cell line was chose since recent studies have shown that the liver is potentially the most frequently targeted organ by cosmetic ingredients, and beyond that, considering the widely application of in vitro assays to test the cutaneous permeation of cosmetic products, including the assays applying modified Franz cells, this technique becomes indispensable. Three different cosmetic active substances were used, and the toxicity to HepG2 cells was assessed by the MTT method. The treatment with hyaluronic acid showed no toxicity to HepG2 cells. Treating the cells with P. guajava L. extract were verified that increasing the amount of the extract in the media, the cellular viability decreased, and finally, the treatment of alpha-lipoic acid showed a cytoprotective effect in relation to the treatment with propylene glycol. The study demonstrated the suitability in using HepG2 cells to assess the safety of cosmetic active substances, helping in the prediction of if the substance could be hepatotoxic if could reach the bloodstream

The application of neural networks to the analysis of dissolved gases in insulating oil used in transformers

The state of insulating oils used in transformers is determined through the accomplishment of physical-chemical tests, which determine the state of the oil, as well as the chromatography test, which determines possible faults in the equipment. This article concentrate on determining, from a new methodology, a relationship among the variation of the indices obtained from the physical-chemical tests with those indices supplied by the chromatography tests.The determination of the relationship among the tests is accomplished through the application of neural networks. From the data obtained by physical-chemical tests, the network is capable to determine the relationship among the concentration of the main gases present in a certain sample, which were detected by the chromatography tests.More specifically, the proposed approach uses neural networks of perceptron type constituted of multiple layers. After the process of network training, it is possible to determine the existent relationship between the physical-chemical tests and the amount of gases present in the insulating oil.

Histological analysis of healing process after rat teeth replantation maintained in Resveratrol dissolved in dimethyl sufoxide (DMSO)

Tissue repair after replantation of avulsed teeth is directly related to the extent of damage to the cells of the periodontal ligament. Thus, immediate replantation is the treatment of choice for avulsed permanent teeth. To achieve more favorable prognostics, adequate storage media must be used to preserve periodontal ligament cells. A series of storage media are studied and show good results, such as saliva, milk, Hank's balanced solution (HBSS) and ViaSpan. However, recent studies were performed using news and promising storage media. Resveratrol has been extensively studied because of its antioxidant properties and its ability to prolong life of many organisms from yeast to mammals. One of its limitations is its poor solubility in aqueous vehicles. For this reason, the aim of this study was to evaluate the healing repair process after replantation of teeth of rats kept in Resveratrol using dimethyl sulfoxide (DMSO) as a vehicle. This study was approved by the Ethics Committee on Research with Animals, of the School of Dentistry of Araçatuba, Univ. Estadual Paulista, UNESP, Araçatuba, SP, Brazil. Were used 40 male rats, under general anesthesia upper right incisor were extracted and replanted. Treatments were done, dividing in four groups, of 10 animals each. In group I, the teeth were be extracted and immediately replanted into their sockets of origin (positive control). In group II, the teeth were immersed in 50 mL of resveratrol in DMSO (0.0512 g / ml) for 60 minutes. In group III teeth were kept for 60 minutes in 50 ml of DMSO. In group IV, the teeth were kept in dry for the same period (negative control). Then the teeth of animals in Groups II, III and IV were replanted in their sockets. Systemic antibiotics were administrated in all groups, and 60 days post-operative the animals were euthanized. The specimens were processed and stained in HE for histomorphological analysis. The results showed that resveratrol as storage media, was not able to improve the rep

Avaliação do processo de contaminação e remediação de água subterrânea por hidrocarbonetos

Pós-graduação em Engenharia Civil e Ambiental - FEB

Diterpenos tetranorlabdanos e isocumarinas produzidos por Botryosphaeria parva, um fungo endofítico em Eugenia jambolana Lam. (Myrtaceae)

Pós-graduação em Química - IQ