Supplementation of iron alone and combined with vitamins improves haematological status, erythrocyte membrane fluidity and oxidative stress in anaemic pregnant women

Pregnancy is a condition exhibiting increased susceptibility to oxidative stress, and Fe plays a central role in generating harmful oxygen species. The objective of the present study is to investigate the changes in haematological status, oxidative stress and erythrocyte membrane fluidity in anaemic pregnant women after Fe supplementation with and without combined vitamins. The study was a 2 months double-blind, randomised trial. Pregnant women (n 164) were allocated to four groups: group C was the placebo control group; group I was supplemented daily with 60 mg Fe (ferrous sulphate) daily; group IF was supplemented daily with Fe plus 400 µg folic acid; group IM was supplemented daily with Fe plus 2 mg retinol and 1 mg riboflavin, respectively. After the 2-month trial, Hb significantly increased by 15·8, 17·3 and 21·8 g/l, and ferritin by 2·8, 3·6 and 11·0 µg/l, in the I, IF and IM groups compared with placebo. Polarisation (¿) and microviscosity (¿) decreased significantly in other groups compared with placebo, indicating an increase in membrane fluidity. Significant decreases of ¿ and ¿ values compared with group C were 0·033 and 0·959 for group I, 0·037 and 1·074 for group IF and 0·064 and 1·865 for group IM, respectively. In addition, significant increases of glutathione peroxidase activities and decreases of malondialdehyde were shown in all treated groups, as well as increases of plasma retinol and urine riboflavin in group IM. The findings show that supplementation with Fe and particularly in combination with vitamins could improve the haematological status as well as oxidative stress and erythrocyte membrane fluidit

Model for initiation of quality factor degradation at high accelerating fields in superconducting radio-frequency cavities

A model for the onset of the reduction in SRF cavity quality factor, the so-called Q-drop, at high accelerating electric fields is presented. Breakdown of the surface barrier against magnetic flux penetration at the cavity equator is considered to be the critical event that determines the onset of Q-drop. The worst case of triangular grooves with low field of first flux penetration Hp, as analyzed previously by Buzdin and Daumens, [1998 Physica C 294: 257], was adapted. This approach incorporates both the geometry of the groove and local contamination via the Ginzburg-Landau parameter kappa, so the proposed model allows new comparisons of one effect in relation to the other. The model predicts equivalent reduction of Hp when either roughness or contamination were varied alone, so smooth but dirty surfaces limit cavity performance about as much as rough but clean surfaces do. When in combination, contamination exacerbates the negative effects of roughness and vice-versa. To test the model with actual data, coupons were prepared by buffered chemical polishing and electropolishing, and stylus profilometry was used to obtain distributions of angles. From these data, curves for surface resistance generated by simple flux flow as a function of magnetic field were generated by integrating over the distribution of angles for reasonable values of kappa. This showed that combined effects of roughness and contamination indeed reduce the Q-drop onset field by ~30%, and that that contamination contributes to Q-drop as much as roughness. The latter point may be overlooked by SRF cavity research, since access to the cavity interior by spectroscopy tools is very difficult, whereas optical images have become commonplace. The model was extended to fit cavity test data, which indicated that reduction of the superconducting gap by contaminants may also play a role in Q-drop.Comment: 15 pages with 7 figure

Strip twisted electrospun nanofiber yarns: Structural effects on tensile properties

Nanofiber yarns with controlled twist levels were prepared by twisting a narrow fibrous strip cut directly from electrospun nanofiber mats. The effects of fiber morphology, diameter and orientation, as well as the yarn twist level on the yarn tensile properties were examined. For the yarns made from randomly oriented fine uniform nanofibers (e.g., diameter 359 nm) and beaded nanofibers, the tensile strength increased with increasing the yarn twist level. Higher fiber diameter (e.g., 634 nm) led to the tensile strength having an initial increase and then decrease trend. The modulus increased with the twist level for all the yarns studied. However, the elongation at break increased initially with the twist level and subsequently decreased. The orientation of aligned fibers within the fiber strip greatly influenced the yarn tensile properties. When the fibers were oriented along the fiber length direction, both tensile strength and modulus were the largest

Enantioselective hydrolysis of 2, 2-disubstituted oxiranes mediated by microsomal epoxide hydrolase

2-Aryl-2-methyloxiranes are enantioselectively hydrolyzed with microsomal epoxide hydrolase from pig liver to provide 1, 2-diols containing a tertiary benzylic alcohol stereogenic centre upto 34% enantio-meric purities

Study of thermal behavior of phytic acid

O ácido fítico é um composto natural muito utilizado como despigmentante em emulsões cosméticas magistrais. No entanto, observou-se experimentalmente que o ácido fítico, quando aquecido a 150 °C durante cerca de uma hora, mostra evidências de decomposição térmica e que poucos estudos envolvendo essa espécie, isoladamente quanto a sua estabilidade, estão disponíveis na literatura. Esse fato motivou o estudo de caracterização e de comportamento térmico dessa espécie, empregando a análise térmica (TG/DTG e DSC) e associando os resultados obtidos com aqueles de análise elementar (AE) e espectroscopia de absorção na região do infravermelho. As curvas TG/DTG e DSC permitiram avaliar o comportamento térmico da amostra de ácido fítico e, com isso, foi possível estudar, pelo método termogravimétrico não isotérmico, a cinética dos três principais eventos de perda de massa, o de desidratação I, desidratação II e de decomposição térmica. A associação das técnicas de espectroscopia de absorção no infravermelho e análise elementar permitiu avaliar os produtos intermediários da decomposição térmica do ácido fítico. Os espectros no infravermelho de amostras isoladas durante o aquecimento evidenciaram a diminuição de intensidade da banda de absorção relativa ao estiramento do grupo O-H como consequência do processo de desidratação. Também, os resultados de análise elementar indicaram que nas temperaturas de 95, 150 e 263 ºC houve aumento no teor de carbono e diminuição do teor de hidrogênio. Visualmente, observou-se o escurecimento do material a 150 ºC, indicando que a decomposição térmica do material iniciou-se nessa temperatura. Na temperatura de 380 ºC, a diminuição do teor de carbono e hidrogênio foi devido ao avanço do processo de decomposição térmica. Os resultados da termogravimetria juntamente com aqueles da análise elementar permitiram concluir que há concordância entre as percentagens de ácido fítico encontrado na solução aquosa. O estudo cinético pelo método termogravimétrico não isotérmico mostrou que o processo de desidratação ocorreu em duas etapas. Na etapa I da desidratação ocorreu um processo de vaporização de água (ordem de reação igual a zero). Na etapa II da desidratação foi encontrada uma ordem de reação igual a cinco. Essa mudança na ordem de reação foi atribuída à perda de moléculas de água quimicamente ligada, ao ácido fítico ou à presença de substâncias voláteis. Finalmente, na etapa de decomposição térmica foi observado que a ordem da reação foi igual a um. Para as outras etapas de perda de massa não foi possível a realização do estudo cinético.Phytic acid is a natural compound widely used as depigmenting agent in galenic cosmetic emulsions. However, we have observed experimentally that phytic acid, when heated to 150 ºC for around one hour, shows evidence of thermal decomposition. Few studies investigating this substance alone with regard to its stability are available in the literature. This fact prompted the present study to characterize this species and its thermal behavior using thermal analysis (TG/DTG and DSC) and to associate the results of these techniques with those obtained by elemental analysis (EA) and absorption spectroscopy in the infrared region. The TG/DTG and DSC curves allowed evaluation of the thermal behavior of the sample of phytic acid and enabled use of the non-isothermal thermogravimetric method to study the kinetics of the three main mass-loss events: dehydration I, dehydration II and thermal decomposition. The combination of infrared absorption spectroscopy and elemental analysis techniques allowed evaluation of the intermediate products of the thermal decomposition of phytic acid. The infrared spectra of samples taken during the heating process revealed a reduction in the intensity of the absorption band related to O-H stretching as a result of the dehydration process. Furthermore, elemental analysis results showed an increase in the carbon content and a decrease in the hydrogen content at temperatures of 95, 150, 263 and 380 °C. Visually, darkening of the material was observed at 150 °C, indicating that the thermal decomposition of the material started at this temperature. At a temperature of 380 °C, thermal decomposition progressed, leading to a decrease in carbon and hydrogen. The results of thermogravimetry coupled with those of elemental analysis allow us to conclude that there was agreement between the percentages of phytic acid found in aqueous solution. The kinetic study by the non-isothermal thermogravimetric method showed that the dehydration process occurred in two stages. Dehydration step I promoted a process of vaporization of water (reaction order of zero), whereas dehydration step II showed an order of reaction equal to five. This change in reaction order was attributed to loss of chemically bonded water molecules of phytic acid or to the presence of volatile substances. Finally, the thermal decomposition step revealed an order of reaction equal to one. It was not possible to perform the kinetic study for other stages of mass loss

About the estimative of production of construction equipments for road pavement

OrientadorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e UrbanismoResumo: Para o desenvolvimento de um projeto rodoviário, é conhecida a grande incidência de custos que tem os equipamentos empregados para a sua construção. Um fator importante para a otimização de custos neste tipo de empreendimentos é apresentado neste trabalho, já que há quantidade insuficiente de uma literatura clara e concisa sobre a produção de alguns equipamentos. Este estudo tem como objetivo identificar, descrever e analisar as diversas variáveis, que condicionam o desempenho dos equipamentos empregados na execução de bases e revestimentos de pavimentos flexíveis, propor métodos e criar ábacos para a fácil determinação da produção dos mesmos. Conhecendo a interação das variáveis será mais simples que engenheiros ligados ao projeto, execução e manutenção de rodovias tomem uma decisão acertada. Palavras-chave: Pavimentação, Equipamentos de Construção, Estimativa de ProduçãoAbstract: In the development of a road project, it is known that one of the most significant contributors for the high costs are the equipments used for its construction. As there are few clear and concise literatures about production of some equipments, important factors in cost optimization in this type of enterprises will be presented in this work. The objective of this study is to identify, describe and analyze several variables that influence the equipment performance used in the execution of bases course and surfacing course of flexible pavement, propose methods and create abacs that provide an easy determination of equipment production. By knowing the interaction of the variables, it becomes easier to engineers who work in project, execution and maintenance of highways to take a mode accurate decision. Key words: Pavement, Construction Equipment, Estimative of ProductionMestradoTransportesMestre em Engenharia Civi

Development of a method for the simultaneous detection of Cr(iii) and Cr(vi) in exhaled breath condensate samples using μLC-ICP-MS

The method described in this study is a robust and sensitive method for the simultaneous determination of trivalent and hexavalent chromium (Cr(III) and Cr(VI)) in an exhaled breath condensate (EBC) sample and drinking water proficiency testing material sample. The method uses a hyphenated micro liquid chromatography (mLC) system coupled to inductively coupled plasma mass spectrometry (ICP-MS). The optimised method incorporates a pH adjusted EDTA complexation step to stabilise Cr(VI) and Cr(III). Separation was achieved using an anion exchange micro-sized column. The limits of quantification were 0.040 mg L-1 and 0.013 mg L-1 for Cr(III) and Cr(VI) respectively. EBC is the non-invasive collection of condensate from cooled exhaled breath during regular tidal breathing. We propose that EBC may be a suitable alternative biological matrix to give a more comprehensive picture of exposure to Cr(VI) following an inhalation exposure. This study shows that water samples and EBC samples containing Cr(III) and Cr(VI) can be stored in the fridge (~4 C) for up to 6 weeks when they have been diluted 10 fold with an EDTA solution, and that EBC samples must not be frozen after collection if the integrity of Cr(VI) is to be maintained. This study has demonstrated a practical approach to collecting EBC samples from workers potentially occupationally exposed to hexavalent chromium and that the integrity of the chromium species will be maintained prior to analysis

Revisiting the implications of Liouville's theorem to the anisotropy of cosmic rays

We present a solution to Liouville's equation for an ensemble of charged particles propagating in magnetic fields. The solution is presented using an expansion in spherical harmonics of the phase space density, allowing a direct interpretation of the distribution of arrival directions of cosmic rays. The results are found for chosen conditions of variability and source distributions. We show there are two conditions for an initially isotropic flux of particles to remain isotropic while traveling through a magnetic field: isotropy and homogeneity of the sources. The formalism is used to analyze the data measured by the Pierre Auger Observatory, contributing to the understanding of the dependence of the dipole amplitude with energy and predicting the energy in which the quadrupole signal should be measured

Developing a labview based thermally stimulated current (tsc) controller to measure residual charge in electrospinning

Electrospinning is an electrohydrodynamic process for the fabrication of nanofibers which are widely used in therapeutical tissue engineering approaches. It utilizes the potential difference of an electrostatic field to overcome the surface tension of the polymer solution to extrude a fine jet of fluid which deposits on the grounded collector as a nanofiber mat. Using this process, nanofibers with diameters less than a micron can be produced. Previous studies have shown the presence of residual charge in electrospun nanofibers. The presence and decay of residual charge during cell culture media is still unknown. In an attempt to clarify the presence or absence of residual charge during cell culture, a LabVIEW based Thermally Stimulated Current controller is designed. The LabVIEW controller encapsulates the temperature and the electrometer control using RS- 485 and GPIB interfaces. The controller outputs a Temperature-Current plot which is the Thermally Stimulated Current spectrum. The current observed at the melting point of the electrospun material is a direct measure of the residual charge trapped within the nanofiber mat. Using this technique electrospun PolyCaproLactone (PCL) mats are analyzed before and after immersion in culture media and Phosphate Buffer Solution (PBS) for 1, 4 and 7 days