Hyperprolactinemia: an inductor of neoplastic changes in endometrium? A report of two cases

Mast cell stabilizers are commonly used in the treatment of asthma and allergic disorders. Although the role of mucosal mast cells in the pathogenesis of inflammatory bowel disease remains uncertain, mast cell stabilizers have been shown in animal models to attenuate the severity of experimental colitis. The authors' experience with ketotifen in three patients--one each with Crohn's disease, ulcerative colitis and collagenous colitis--who had demonstrated allergy to, or intolerance of, 5-aminosalicylic acid is reported.     

Experimental analysis and numerical simulation of sintered micro-fluidic devices using powder hot embossing process

For the past 2 years, interest in manufacturing technologies based on micro-fluidic systems has been continuously increasing. Today, micro-fluidic systems are used in numerous biomedical and pharmaceutical applications. Micro-fluidics cannot be thought about separately without advances in micro- and nano-fabrication. Investigations based on experiments, finite element modelling and simulations of powder hot embossing process (PHE) were performed to optimise the sintering step and processing parameters of micro-fluidic components. The model pertaining to thermo-elasto-viscoplastic behaviour was identified for 316L stainless steel powders. In this regard, different material properties such as sintering stress, bulk, and shearing viscosities were identified by inverse analysis from present dilatometer measurements using beam-bending and free sintering tests. The identification of materials was performed for various powder volume loadings and kinetic rates for different 316L elaborated feedstock, and the parameters were obtained as functions of relative density. The initial inhomogeneity due to the PHE process has been taken into account in the sintering simulation, as it affects the final shrinkage of the sintered components. The solid-state sintering simulations were investigated for various final sintering temperatures and kinetic rates to obtain high and homogeneous relative density distributions, achieve isotropic shrinkage and optimise the sintering process parameters. The numerical simulations were realised based on the identified parameters on a 3D micro-structured specimen with an associated rectangular plate support elaborated by PHE; this allowed a comparison between the numerical predictions and the experimental results for the sintering stage. The finite element simulation results of the sintering stage with a micro-fluidic structured component at a high final temperature (1360 °C) are in excellent agreement with the results of the experiments. The comparison of the simulation and experimental results validated the identified and implemented physical model and proposed methodologies.     

Polarization process in FeF3 thin films

A.c. and thermally stimulated depolarization measurements are used to study the polarization mechanisms in FeF₃ thin films. A normalized curve is proposed which shows that the parallel conductance behaviour is governed by a distribution of relaxation times τ equal to τ₀ exp $\text{(}\text{E}\text{kT}\text{)}$. The d.c. model permits the polarization process to be discussed on the basis of successive transfers of electrons from site-to- sites along paths which become shorter and shorter as the frequency increases.     

Thromboxane synthase expression in renal transplant patients with rejection

Thromboxane synthase (TS) catalyzes the formation of thromboxane (TxA2) in monocytes/macrophages, platelets, and various tissues. TxA2 is likely to play a role in graft dysfunction due to its vasoconstrictive and platelet aggregatory properties. We studied the expression of TS in 7 normal native kidneys, 29 consecutive renal allograft biopsies (performed for rising serum creatinine, n = 23, and delayed graft function, n = 6), and one transplant nephrectomy specimen with severe acute rejection. TS expression was determined by immunocytochemistry using a monoclonal antibody against human TS, Kon-7. Histologic grading of the transplant biopsy specimens was based on the Banff classification. The degree of TS staining was graded in the glomeruli, interstitium, tubules and vessels from 0 to 3+. Of 29 biopsies, 13 had chronic nephropathy (CN), 6 had acute rejection (AR) with chronic nephropathy (AR/CN), 4 had acute rejection (AR), and 6 had acute tubular necrosis (ATN). TS staining of native kidneys showed sporadic interstitial cells. The biopsy and transplant nephrectomy specimens showed significant staining, predominantly in the glomeruli and interstitium. Positively staining cells appeared to be of macrophage/monocyte lineage by morphology. The mean glomerular staining grade was significantly increased in specimens with AR (2.3 +/- 0.9) and the mean interstitial staining was increased in specimens with AR/CN (2.2 +/- 0.9). Follow-up renal function 6 months post-biopsy showed that patients with higher TS staining grades had a faster decline in graft function. In conclusion, TS expression is increased in patients with acute rejection with or without chronic nephropathy and is associated with more rapid deterioration in function.     

Improving Gas Sequestration by Surfactant‐Alternating‐Gas Injection: A Comparative Evaluation of the Surfactant Type and Concentration

Gas injection into porous subsurface geological formations for geological storage is currently considered the most preferable and practicable means of reducing greenhouse gases due to the huge capacity of deep saline aquifers. Residual trapping of gas plays an important role in immobilization of injected gas into an aquifer. Surfactant‐alternating‐gas (SAG) injection can be used as a mobility control method in gas sequestration and several simulation studies explained different aspects of residual‐gas trapping. However, research in this field is inconclusive and needs more attention to develop a better understanding. In this work, we used 3 different surfactants from different classes at various concentrations to assess gas‐sequestration efficiency using SAG methods in carbonate and sandstone rocks. This work is the first of its kind on the comparative performance of different surfactants for gas sequestration in different rocks. The surfactants were hydrocarbon zwitterionic, fluorinated zwitterionic, and nonionic. It was found that residual‐gas saturation increases by increasing the surfactant concentration. The increase in residual trapping with surfactant concentration also depends on the type of surfactant and rock. In both rock types considered, the best performance was achieved using fluorinated zwitterionic surfactants followed by hydrocarbon zwitterionic surfactants. In addition, a synergetic effect between hydrocarbon and fluorinated surfactants further improves the residual‐gas saturation. The residual‐gas trapping was higher in the tight sample compared to highly permeable samples. This will help in developing an understanding of surfactant optimization and selection for gas sequestration using the SAG method.     

Mapping MMOFPS over heterogeneous distributed systems

This paper evaluates the effects on performance of taking the heterogeneity of nodes into account, in terms of number of cores, when MMOFPS (Massively Multiplayer Online First Person Shooter) game services are distributed. Two mapping strategies, Non_Heterogeneity_aware and Heterogeneity_aware, are integrated in a system, called OnDeGaS (On Demand Game Service), which is a hybrid between Client-Server and P2P topologies. Through simulation, we show that the Heterogeneity_aware mechanism has more impact in communication costs, but it is more efficient in exploiting the nodes of the P2P area, as it maps players faster and it creates less computing zones with latency values under the acceptable threshold for MMOFPS games.     

Analysis and quantification of parabens in cosmetic products by utilizing hollow fibre-supported liquid membrane and high performance liquid chromatography with ultraviolet detection

A simple and direct method based on hollow fibre-supported liquid membrane (HFSLM) extraction and liquid chromatography equipped with a UV detector was developed for analysis and quantification of parabens in cosmetic products. The parabens analysed included methyl, ethyl, propyl, isobutyl and butyl paraben. The HFSLM extraction was carried out by employing di- n -hexyl ether as organic liquid that was immobilized in the hollow fibre membrane. The HFSLM extraction is simple, cheap, minimizes the use of solvents and uses disposable material. In an investigation of 11 paraben-containing cosmetic products, the levels of parabens (sum of all parabens in a product) ranged from 0.43% to 0.79% (w/w) for skin care products, 0.07–0.44% for hair fixing gels and 0.30–0.52% for soap solutions. The levels of individual parabens in individual cosmetic products ranged between 0.03% and 0.42% w/w for skin care products, 0.07% and 0.26% w/w for hair fixing gels and between 0.11% and 0.34% w/w for soap solutions. Parabens were found in the highest concentrations in skin care products followed by soap solutions and the least amounts were found in hair fixing gels. Of the paraben-containing products tested, all of them contained methyl paraben and about 90% contained propyl paraben in addition to methyl paraben. One product contained all the parabens analysed.     

A capillary fluorescence standard for microfluorometry

Quartz glass capillaries of about 6 μm inside diameter were filled with fluorochrome solutions of accurately known concentrations and embedded as microscopical objects. The fluorescence intensity of a constant capillary volume has been found to be directly proportional to the amount of the excited fluorochrome in this volume within the fluorochrome concentration range 1:10³. The capillary volume can be determined accurately by microinterferometric measurement of the inside diameter. The capillary section irradiated by the exciting light may be considered as very small in comparison with the total length of the capillary tube. During and after irradiation the excited part of fluorochrome solution is continuously renewed by convectional flow and diffusion. Therefore photodecomposition does not affect the measured fluorescence intensity, and the standard value remains unchanged even after numerous measurements. Thus, these fluorescence standards may be used to make successive calibrations of a microfluorometer and to check the constancy and reproducibility of measuring conditions. In certain circumstances it also permits measured fluorescence intensity to be interpreted in terms of the amount of fluorochrome or fluorescent substance. The results achieved with the capillary fluorescence standard are compared with those obtained by means of conventional methods. In addition, some essential optical properties of the microfluorometer equipment required for the proper use of this standard are discussed.     

Mécanismes de conduction en liaison avec les conditions de préparation de couches minces de fluorure de magnésium

The electrical properties of evaporated magnesium fluoride thin films are studied in relation to the conditions of preparation. Results concerning the d.c. and a.c. conduction are given for two series of films. The first series of layers, obtained under “normal” conditions, give the same resistivity as that obtained in previous studies: from 300° to 500°K the conduction is of the Poole-Frenkel type. For the second series of layers obtained under the best conditions of preparation, particularly after refluoration of the powder before sublimation, we have observed an increase of resistivity by a factor of 10². In this case, the conductivity through metal-MgF₂-metal structures is attributed to a “hopping” process for temperatures below 400°K and to the Poole-Frenkel mechanism from 400° to 450°K, whereas above 450°K it presents ionic characteristics. The use of different analysis techniques has allowed an identification of the impurities probably responsible for these conduction mechanisms.