Relevance of BRAF Subcellular Localization and Its Interaction with KRAS and KIT Mutations in Skin Melanoma

Although skin melanoma (SKM) represents only one-quarter of newly diagnosed skin malignant tumors, it presents a high mortality rate. Hence, new prognostic and therapeutic tools need to be developed. This study focused on investigating the prognostic value of the subcellular expression of BRAF, KRAS, and KIT in SKM in correlation with their gene-encoding interactions. In silico analysis of the abovementioned gene interactions, along with their mRNA expression, was conducted, and the results were validated at the protein level using immunohistochemical (IHC) stains. For IHC expression, the encoded protein expressions were checked on 96 consecutive SKMs and 30 nevi. The UALCAN database showed no prognostic value for the mRNA expression level of KRAS and BRAF and demonstrated a longer survival for patients with low mRNA expression of KIT in SKMs. IHC examinations of SKMs confirmed the UALCAN data and showed that KIT expression was inversely correlated with ulceration, Breslow index, mitotic rate, and pT stage. KRAS expression was also found to be inversely correlated with ulceration and perineural invasion. When the subcellular expression of BRAF protein was recorded (nuclear vs. cytoplasmatic vs. mixed nucleus + cytoplasm), a direct correlation was emphasized between nuclear positivity and lymphovascular or perineural invasion. The independent prognostic value was demonstrated for mixed expression of the BRAF protein in SKM. BRAF cytoplasmic predominance, in association with KIT’s IHC positivity, was more frequently observed in early-stage nonulcerated SKMs, which displayed a low mitotic rate and a late death event. The present study firstly verified the possible prognostic value of BRAF subcellular localization in SKMs. A low mRNA expression or IHC cytoplasmic positivity for KIT and BRAF might be used as a positive prognostic parameter of SKM. SKM’s BRAF nuclear positivity needs to be evaluated in further studies as a possible indicator of perineural and lymphovascular invasion.     

Polyurethane cationomers with nitroazoaromatic groups

Novel polyurethane cationomers bearing p-nitroazoaromatic groups covalently incorporated in the polymer chain were synthesized. Their photobehavior in polymer films and solutions was investigated by electronic absorption spectroscopy and was also evaluated comparatively with an ionic azodiol model. Under UV irradiation, in the first stage of the photoprocess the trans-cis isomerization occurs, followed then by a photobleaching reaction in the second stage of the process.     

Progress in Raman spectroscopy in the fields of tissue engineering, diagnostics and toxicological testing

This review summarises progress in Raman spectroscopy and its application in diagnostics, toxicological testing and tissue engineering. Applications of Raman spectroscopy in cell biology are in the early stages of development, however, recent publications have demonstrated its utilisation as a diagnostic and development tool with the key advantage that investigations of living cells can be performed non-invasively. Some of the research highlighted here demonstrates the ability of Raman spectroscopy to accurately characterise cancer cells and distinguish between similar cell types. Many groups have used Raman spectroscopy to study tissues, but recently increased effort has gone into single cell analysis of cell lines; the advantages being that cell lines offer ease of handling and increased reproducibility over tissue studies and primary cells. The main goals of bio-Raman spectroscopy at this stage are twofold. Firstly, the aim is to further develop the diagnostic ability of Raman spectroscopy so it can be implemented in a clinical environment, producing accurate and rapid diagnoses. Secondly, the aim is to optimise the technique as a research tool for the non-invasive real time investigation of cell/material interactions in the fields of tissue engineering and toxicology testing.     

Mixed convection in laminar film flow of a micropolar fluid

In this paper, the steady mixed convection boundary layer in laminar film flow of a micropolar fluid is considered. The resulting nonlinear coupled ordinary differential equations are solved numerically using an efficient implicit finite-difference scheme. The numerical results obtained for the skin friction coefficient and the local Nusselt number, as well as the velocity, angular velocity or microrotation and temperature profiles are presented in tables and figures for different values of the material parameter K and the Richardson number Ri when the Prandtl number Pr = 0.7 and Pr = 1.     

A heatline analysis of natural convection in a square inclined enclosure filled with a CuO nanofluid under non-uniform wall heating condition

Heatline visualization technique is used to understand heat transport path in an inclined non-uniformly heated enclosure filled with water based CuO nanofluid. The cavity has square cross-section and it is non-uniformly heated from a wall and cooled from opposite wall while other walls are adiabatic. The governing equations which are continuity, momentum and energy equations are solved using finite volume method. The dimensionless heatfunction for nanofluid heat flow is defined and solved to determine heatline patterns. Calculations were performed for Rayleigh numbers of 10³, 10⁴ and 10⁵, inclination angle of 0°, 30°, 60° and 90°, and nanoparticle fraction of 0, 0.02, 0.04, 0.06, 0.08 and 0.1. It is observed that heat transfer in the cavity increases by adding nanoparticles. The rate of increase is greater for the enclosures with low Rayleigh number. Visualization of heatline is successfully applied to nanoparticle convective flows. Based on the heatline patterns, three heat transfer regions are observed and discussed in details.     

Brinkman–Forchheimer modeling for porous media thermoacoustic system

In this paper, analytical studies have been conducted on the flow and thermal fields of unsteady compressible viscous oscillating flow through channels filled with porous media representing stacks in thermoacoustic systems. The flow in the porous material is described by the Brinkman–Forchheimer–extended Darcy model. Analytical expressions for oscillating velocity, temperature, and energy flux density are obtained after linearizing and solving the governing differential equations with long wave, short stack, and small amplitude oscillation approximations. Experimental work is also conducted to verify the temperature difference obtained across the porous stack ends. To produce the experimental results, a thermoacoustic heat pump is designed and constructed where reticulated vitreous carbon (RVC) is used as the stack material. A very good agreement is obtained between the modeling and the experimental results. The expression of temperature difference across the stack ends obtained in the present study is also compared with the existing thermoacoustic literature. The proposed expression surpasses the existing expression available in the literature. The system of equations developed in the present study is a helpful tool for thermal engineers and physicist to design porous stacks for thermoacoustic devices.     

MHD mixed convection in a lid-driven cavity with corner heater

Laminar mixed convection flow in the presence of magnetic field in a top sided lid-driven cavity heated by a corner heater was considered. The corner heater is under isothermal boundary conditions with different length in bottom and right vertical walls. Finite volume technique was used to solve governing equations. The temperature of the lid is lower than that of heater. The study is performed for different Grashof and Hartmann numbers at Re = 100. The obtained results showed some very interesting results.     

Synthesis and hydrogen adsorption properties of a new iron based porous metal-organic framework

A new metal-organic framework [Fe₃O(OOC-C₆H₄-COO)₃(H₂O)₃]Cl·(H₂O)_x was synthesized with a specific surface area of 2823 m²/g and a lattice parameter of 88.61 Å. Isostructural with MIL-101, this compound exhibits similar hydrogen adsorption properties, with maximum adsorption capacity of 5.1wt.% H at 77 K. The adsorption enthalpy of hydrogen for MIL-101 and ITIM-1 (MIL-101Fe) at zero coverage was calculated for a wide temperature range of 77 K ÷ 324 K, considering corrections for the variation of hydrogen gas entropy with the temperature. The resulted adsorption enthalpy is 9.4 kJ/mol for MIL-101, in excellent agreement with the value reported in literature from microcalorimetric measurements, and a value of 10.4 kJ/mol at zero coverage was obtained for ITIM-1 (MIL-101Fe).     

Superparamagnetic Unusual Behavior of Micrometric Magnetite Monodisperse Monocrystals Synthesized by Fe-EDTA Thermal Decomposition

We developed a new procedure for synthesizing micrometric magnetite by hydrothermal decomposition of the Fe-EDTA complex in the presence of urea, starting from Fe(III)-ferric ammonium sulfate and Na₄EDTA as main precursors. Microcrystals with superparamagnetic behavior with 25–45 μm in size were obtained (5 emu/g at 3.8 kOe magnetic field).