Hyperthyroidism and production of precocious involution in the mammary glands of lactating rats

This study investigated the influence of chronic hyperthyroidism on mammary function in lactating rats and the effects on their pups. Thyroxine-treated (10 microg per 100 g body weight per day; hyperthyroid (HT)) or vehicle-treated rats were mated 2 weeks after the start of treatment and killed with their litters on days 7, 14 and 21 of lactation. Serum concentrations of triiodothyronine (T(3)) and tetraiodothyronine (T(4)) increased in thyroxine-treated rats. In HT mothers, serum prolactin decreased on day 7 and day 14 of lactation, whereas insulin-like growth factor I (IGF-I) and progesterone concentrations decreased, and corticosterone increased on day 7 of lactation. In HT pups, T(4) concentration increased on day 7 and day 14 of lactation, whereas T(3) increased only on day 14 of lactation, and growth hormone increased on day 7 of lactation. Mammary prolactin binding sites did not vary, but there was an increase in the binding sites in the liver on day 14 of lactation in thyroxine-treated rats. In an acute suckling experiment, thyroxine-treated rats released less oxytocin, growth hormone and prolactin and excreted less milk than did control rats. Mammary casein, lactose and total lipid concentrations in thyroxine-treated rats were similar to those of control rats on day 14 of lactation. Histological studies of the mammary glands showed an increased proportion of alveoli showing reduced or no lumina and cells with condensed nuclei on day 14 and day 21 of lactation; the TdT-mediated dUTP nick-end labelling (TUNEL) test revealed an increase in apoptosis in alveolar cells on day 21 of lactation in thyroxine-treated rats. Expression of SGP-2, a gene expressed during mammary involution, increased in thyroxine-treated rats on day 14 and day 21 of lactation, whereas expression of insulin-like growth factor binding protein 5, a proapoptotic signal, was unchanged. Bcl-2, which promotes survival of mammary gland epithelial cells was unchanged, whereas expression of IGF-I, which also promotes survival of mammary gland epithelial cells, increased on day 21 of lactation in thyroxine-treated rats. These results indicate that thyroxine treatment produces some milk stasis as a result of impairments in suckling induced release of oxytocin that may initiate the first stage of mammary involution, increasing apoptosis in a gland that is otherwise actively producing and secreting milk.     

Analysis of the economy of scale and estimation of the future hydrogen production costs at on-site hydrogen refueling stations in Korea

This paper deals with the analysis of the economy of scale at on-site hydrogen refueling stations which produce hydrogen through steam methane reforming or water electrolysis, in order to identify the optimum energy mix as well as the total construction cost of hydrogen refueling stations in Korea. To assess the economy of scale at on-site hydrogen stations, the unit hydrogen costs at hydrogen stations with capacities of 30 Nm³/h, 100 Nm³/h, 300 Nm³/h, and 700 Nm³/h were estimated. Due to the relatively high price of natural gas compared to the cost of electricity in Korea, water electrolysis is more economical than steam methane reforming if the hydrogen production capacity is small. It seems to be the best strategy for Korea to construct small water electrolysis hydrogen stations with production capacities of 100 Nm³/h or less until 2020, and to construct steam methane reforming hydrogen stations with production capacities of 300 Nm³/h or more after 2025.     

Coupled photochemical-biological system to treat biorecalcitrant wastewater.

The aim of the present work is to study a coupled system to treat biorecalcitrant wastewaters. The combination consists of an advanced oxidation process (AOP) named photo-Fenton (Ph-F), which is a photochemical treatment and a sequencing batch biofilter reactor (SBBR). The synthetic wastewater used to optimise this process is a solution of 200 ppm of 4-chlorophenol (4-CP). The first part of the work is the study of the biodegradability enhancement achieved by the photochemical process, measured as the ratio between the biochemical oxygen demand (BOD5) and the chemical oxygen demand (COD). The second step is the start-up and optimisation of the biological process. The results showed that it is necessary to severely treat the toxic solution (with 500 ppm of [H2O2]0) in order to achieve more than 90% of TOC removal in the whole process. The photochemical and biological treatments lasted 50 minutes and 24 hours, respectively.     

Quality Attributes and Shelf Life of High-Pressure Preserved Beef as Affected by Pre-treatment Conditions

This study analyzed the effects of high hydrostatic pressure (HHP) and composition of the pre-treatment immersion step, on quality attributes (color and lipid oxidation) and shelf life based on microbial counts of a beef product, during cold storage at 0 °C. Meat slices were immersed in a preservative solution containing sodium nitrite, ascorbic acid, and two different concentrations of NaCl (30 and 60 g/L); HHP of 400 and 600 MPa were applied. Results were compared with those of an untreated beef control. Color parameters of the HHP-treated beef were visually acceptable (a* > 14) in all tested cases, although they were affected by NaCl concentration and the applied pressure. HHP increased TBARS index, observing higher values at 600 than at 400 MPa; samples immersed in the solution containing 30 g/L NaCl presented higher TBARS values. However, in all cases, they remained below the detection limit of rancid meat products (<1 mg MDA/kg). Beef samples immersed in the solution with the highest concentration of NaCl (60 g/L) and subjected to 400 or 600 MPa maintained their microbial stability over 5 and 6 weeks, respectively, at 0 °C; these shelf life values were higher than those observed in the samples treated with 30 g/L NaCl.     

Formation of studtite during the oxidative dissolution of UO2 by hydrogen peroxide: a SFM study

Understanding the formation of alteration phases on the surface of spent nuclear fuel, such as those observed during leaching experiments, is necessary in order to predict the concentration of radionuclides in the near-field of a final repository. Hydrogen peroxide has been identified as one of the oxidants formed by the radiolysis of water in the presence of spent nuclear fuel; especially due to alpha activity. The presence of this species in solution can contribute to the formation of uranium peroxide secondary phases. In this work, we have studied the oxidative dissolution of synthetic UO2 disks in hydrogen peroxide solutions of two different concentrations (5 x 10(-4) and 5 x 10(-6) mol dm(-3)), both at pH 5.8 +/- 0.1. The solid surface evolution of the disks has been followed by means of ex-situ scanning force microscope (SFM) measurements, and uranium concentration in solution has been determined by inductively coupled plasma mass spectrometry. During the first stage of the experiment, SFM images indicate that only UO2 dissolution is occurring. After 142 h, a secondary phase is observed on the surface of the solid at 5 x 10(-4) mol dm(-3) hydrogen peroxide concentration. This secondary phase has been identified by X-ray diffraction as studtite (UO4 x 4H2O). From the analysis of SFM topographic profiles at different elapsed times, a precipitation rate for the studtite has been estimated to be in the range of (8-32) x 10(-10) mol m(-2) s(-1).     

Nylon fibers coated with diclofenac: adsorption properties

Dried gauzes properly coated with anti-inflammatory drugs could be helpful in providing topical treatment in inflammatory process. Therefore, thermodynamic of adsorption of Diclofenac Sodium, over Nylon fibers, as a function of concentration, temperature, and pH of the medium, have been studied. Maximum amount adsorbed in the best conditions tested, pH 5.6, 323 K and initial concentration of 150 mg/L has been 2.6 mg/g. Isotherm adsorption data were well fitted to the Langmuir and Freundlich model; therefore, multilayer formation must be considered. Negative and low values of free-energy change, ?17.9 kJ/mol and ?15.9 kJ/mol, in addition to moderate value of activation energy 13.14 kJ/mol point to physical interactions governing the process that, besides, is exothermic with negative enthalpy-change, ?43.44 kJ/mol, and also follows pseudo-first order kinetic model that is typical of this interaction. Desorption experiments carried out under physiological conditions confirm that the proposed procedure for DCF administration could be achieved.     

Bottom‐Up Fabrication of Semiconductive Metal–Organic Framework Ultrathin Films

Though generally considered insulating, recent progress on the discovery of conductive porous metal–organic frameworks (MOFs) offers new opportunities for their integration as electroactive components in electronic devices. Compared to classical semiconductors, these metal–organic hybrids combine the crystallinity of inorganic materials with easier chemical functionalization and processability. Still, future development depends on the ability to produce high‐quality films with fine control over their orientation, crystallinity, homogeneity, and thickness. Here self‐assembled monolayer substrate modification and bottom‐up techniques are used to produce preferentially oriented, ultrathin, conductive films of Cu‐CAT‐1. The approach permits to fabricate and study the electrical response of MOF‐based devices incorporating the thinnest MOF film reported thus far (10 nm thick).