The Effect of Electroporation of a Lyotroic Liquid Crystal Genistein-Based Formulation in the Recovery of Murine Melanoma Lesions

A lamellar lyotropic liquid crystal genistein-based formulation (LLC-Gen) was prepared in order to increase the aqueous solubility of the lipophilic phytocompound genistein. The formulation was applied locally, in a murine model of melanoma, with or without electroporation. The results demonstrated that, when the formulation was applied by electroporation, the tumors appeared later. During the 21 days of the experiment, the LLC-Gen formulation decreased the tumor volume, the amount of melanin and the degree of erythema, but when electroporation was applied, all these parameters indicated a better prognosis even (lower tumor volume, amount of melanin and degree of erythema). Although hematoxylin–eosin (HE) staining confirmed the above events, application of the LLC-Gen formulation by electroporation did not lead to a significant effect in terms of the serum concentrations of the protein S100B and serum neuron specific enolase (NSE), or the tissue expression of the platelet-derived growth factor receptor β (PDGFRβ) antibody.     

Robocast zirconia-toughened alumina scaffolds: Processing,structural characterisation and interaction with human primary osteoblasts

Zirconia-toughened alumina (ZTA) is the gold-standard ceramic in hip arthroplasty, but still lacks direct osseointegration and a metal shell, often coated with a bioactive layer, is currently required. The latter could potentially be replaced by a thinner, architectured ZTA layer, thereby allowing for larger acetabular components, with larger range of motion and lower dislocation risk. Robocasting may be an adequate technique to fabricate the architectured layer. Therefore, as a first step, this study aimed to produce ZTA scaffolds (3D-ZTA) by robocasting and assess their in vitro response. Shape retention was achieved by using a stable, well-dispersed, high solid loading ink injected in acid pH waterbath. 3D-ZTA exhibit regularly spaced microporous, rough struts and fully interconnected macroporosity. Human primary osteoblasts were homogenously distributed inside 3D-ZTA and showed increased osteogenic marker expression compared to 2D-ZTA control. Further work will focus on optimizing scaffold design to improve cell retention and extracellular matrix maturation.     

Separation of Trimethyl Borate from a Liquid Mixture by Pervaporation

Four commercial polyvinyl alcohol (PVA) and polydimethylsiloxane (PDMS) membranes were applied to the pervaporation of an azeotropic mixture containing trimethyl borate, a precursor to boronic acids used in Suzuki couplings and a gaseous anti‐oxidant in solder flux or brazing. The degree of cross‐linking of the chains in the active layer played a crucial role in the membrane process using the membranes PERVAP 4155‐80, PERVAP 4155‐40 and PERVAP 4155‐30. PERVAP 4155‐30 reached the best results from all tested membranes; an impressive selectivity with fast permeation was also achieved with the PERVAP 4060 membrane. Methanol preferentially passed through PERVAP 4155‐30, but trimethyl borate was favorably pervaporated from the mixture by PERVAP 6040, due to the diverse affinities of the membranes.     

A comprehensive review of solar thermoelectric cooling systems

The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. This paper provides an overview of solar thermoelectric (TE) cooling systems. Thus, this review presents the details referring to TE cooling parameters and formulations of the performance indicators and focuses on the development of TE cooling systems in recent decade with particular attention on advances in materials and modeling and design approaches. Additionally, the TE cooling applications have been also reviewed in aspects of electronic cooling, domestic refrigeration, air conditioning, and power generation. Finally, the possibility of solar TE cooling technologies application in “nearly zero” energy buildings is briefly discussed, and some future research directions are included. This research shows that TE cooling systems have advantages over conventional cooling devices, including compact in size, light in weight, high reliability, no mechanical moving parts, no working fluid, being powered by direct current, and easily switching between cooling and heating modes.     

Radionuclide contamination of foods imported into Iraq following the Chernobyl nuclear reactor accident

Since early 1986, a monitoring program for radionuclides in imported foods has been carried out by the Iraqi Atomic Energy Commission. After the Chernobyl nuclear reactor accident in the Soviet Union, the program was expanded; our laboratory was officially designated by the Iraqi Government to measure radionuclide activity concentrations in foodstuff imported from countries known to be severely contaminated by Chernobyl radioactive fallout. Gamma-spectrometric analysis was used. Food items such as powdered milk, lamb meat, poultry, cereals and grains imported into Iraq before the Chernobyl accident did not contain any detectable fission products. However, all lamb meat, 81% of the lentil, 44% of the powdered milk and chick-pea, and 17% of the roast beef samples were contaminated with 137Cs or 134Cs and 137Cs. The highest 137Cs contamination levels found were 82, 147, 420, 6 and 4 Bq kg-1, respectively. Contamination by 134Cs was approximately 50% of the values given above.     

The Optimization of the Production of Methyl Esters from Corn Oil Using Barium Hydroxide as a Heterogeneous Catalyst

In recent years, vegetable oils, as renewable raw materials, became a promising feedstock for chemicals and biodiesel production. The main products derived from oils are esters of fatty acids, especially methyl esters, obtained by their transesterification with methanol, in presence of acid or alkaline catalysts. The use of such catalysts implies the need for washing operations, which leads to environmental pollution. In the present paper, the response surface methodology based on a central composite design, has been developed to optimize the process of transesterification of corn oil. Ba(OH)₂ in presence of diethyl ether was used as catalyst. A quadratic polynomial equation was obtained. It correlates the reaction parameters [methanol/oil molar ratio (x _r), reaction time (x _t) and catalyst concentration (x _c)] with methyl esters yield. Analysis of variance analysis showed that only methanol/oil molar ratio and catalyst concentration have had the most significant influences on the conversion. The maximum methyl esters yield was obtained using the following optimum parameters: methanol/corn oil ratio of 11.32, reaction time of 118 min and catalyst concentration of 3.6 wt%.     

Amphiphilic Properties of Dodecylammonium Chloride/4-(1-Pentylheptyl) Benzene Sodium Sulfonate Aqueous Mixtures and Study of the Catanionic Complex

Surfactants are often used in supramolecular chemistry, due to their ability to self-organize. Surfactant molecules aggregate spontaneously and reversibly to adopt a defined intermolecular arrangement. In this work, general phase behavior, adsorption and association in aqueous mixtures of dodecylammonium chloride, DACl and sodium 4-(1-pentylheptyl) benzenesulfonate, NaDBS, were studied by a combination of techniques including surface tension and conductivity measurements, light scattering and optical microscopy. The strong synergistic properties of the system were brought out with the Regular Solution Theory. Various colloidal objects are observed in wide range of composition: conventional small vesicles, large giant multilamellar or multivesicular vesicles. An excess of NaDBS provides extremely large tubular and elongated multilamellar vesicles. The new catanionic 1:1 complex, dodecylammonium-4-(1-pentylheptyl) benzenesulfonate, formed in the equimolar conditions is a result of intramolecular charge neutralization. The thermal properties of this solid compound were examined by thermal polarizing microscopy, differential scanning calorimetry, and X-ray diffraction. The most probable ion-pair amphiphilic cluster of the crystal smectic phase, at room temperature, consists of ionic groups formed in ordered layers with dodecyl chains packed into somewhat disordered layers, tilted to the layer plane.     

Simultaneous oxidation of aromatic compounds using Sr-doped lanthanum manganites as catalysts

Strontium-doped lanthanum manganites, La_1-xSr_xMnO₃ (LSMO), are promising and affordable catalysts for oxidative degradation of volatile organic compounds. LSMO catalysts (x = 0, .1, .2, and .3) were prepared by the citrate-nitrate autocombustion (CNA) and coprecipitation synthesis. The phase composition was confirmed by X-ray diffraction and Rietveld refinement analysis, while the oxygen content was determined by Mohr's salt permanganate titration. Morphology and porosity of prepared catalysts was correlated to catalytic oxidation of benzene, toluene, ethylbenzene and o-xylene. It was observed that both synthesis methods yielded catalysts of similar average pore size diameter and specific surface area, but the pore size distribution differed: CNA-prepared catalysts had a multimodal pore size distribution, while the coprecipitated ones had a single maximum at 4 nm. Catalysts prepared by the CNA method have shown a higher catalytic activity in the temperature range 373–723 K, as the presence of Mn³⁺/Mn⁴⁺ mixed valences increased their reducibility.     

Applicability of the generalized scaling law to a pile-inclined ground system subject to liquefaction-induced lateral spreading

The generalized scaling law is based on the concept of two-stage scaling and allows currently available centrifuge facilities to model a large-scale prototype expanding over the spatial dimension ranging from 30 m or larger subject to earthquake motions. This paper presents the results of investigation on the applicability of the generalized scaling law to the fully nonlinear regime of soil-structure system with the induced strain level of 10% in the order of magnitude. The centrifuge model tests performed in this study under the modeling of models scheme consist of a pile model embedded in a inclined ground subject to liquefaction-induced lateral spreading. Four different centrifugal accelerations ranging from 13g to 50g are used whereas the actual size of the physical model is kept constant with an overall scaling factor of 1/100. The models are exposed to tapered sinusoidal input accelerations of frequency 0.59 Hz and amplitude 3.0 m/s² in prototype scale, and the results are compared in terms of prototype by applying the generalized scaling law. As for the response of the ground during shaking, essentially identical accelerations and excess pore water pressures are recorded for all cases, while the lateral displacement shows a variation ranging from 5% to 9% in terms of shear strain due to a slight variation in experimental conditions (e.g., input peak acceleration, achieved density distribution). Practically the same responses are measured among the cases in the dissipation phase of excess pore water pressure. With regard to pile behavior, nearly identical responses for the lateral displacements and bending moments are obtained for all cases both during and after shaking. These results demonstrated that the generalized scaling law is applicable to the fully nonlinear regime of soil-structure system subject to the cumulative shear strain in the order of 10% due to cyclic mobility of sands during earthquakes.