Possible Mechanisms of Resistance Development to Photodynamic Therapy (PDT) In Vulvar Cancer Cells

Photodynamic therapy (PDT) is a low-invasive treatment method that can be used to treat VIN patients. A photosensitizer (PS) applied to a patient is activated with use of the appropriate wavelength of light, which in an oxygen environment leads to the formation of a reactive oxygen species (ROS) that destroys the tumor. However, cells can protect themselves against these cytotoxic products by increasing their antioxidant mechanisms and repair capacity. Changes in the cytoskeleton may also influence resistance to PDT. Our results revealed that PDT-resistant cells changed the amount of ROS. Cells resistant to PDT A-431 exhibited a decreased ROS level and showed higher viability after oxidizing agent treatment. Resistant Cal-39 cells exhibited a decreased O₂⁻ level but increased other ROS. This provides protection from PDT but not from other oxidizing agents. Moreover, PDT leads to alterations in the cytoskeleton that may result in an epithelial-mesenchymal transition (EMT) or increased adhesion. Both EMT and cell adhesion may activate signaling pathways involved in survival. This means that resistance to PDT in vulvar cancer may be at least in part a result of changes in ROS level and alterations in the cytoskeleton.     

Turkey breast roasting – Process optimization

The objective of the present study was to perform experimental and theoretical analyses of the process of roasting turkey breast slices in a steam-convection oven with a view to determining the optimal values of temperature and steam saturation during roasting, under the assumption of a constant slice thickness. The roasting process was conducted at air temperature of 160 °C, 180 °C, 200 °C and 220 °C and steam saturation of 0%, 20%, 50%, 70% and 90%. Two qualitative criteria based on eating quality and nutritive value have been applied in process optimization. Those criteria proved to be mutually opposing. As regards eating quality, the best product was that roasted at a temperature of 160 °C without the application of steam in the oven. The same product was characterized by the lowest nutritive value. Nevertheless, it should be noted that the protein content of turkey meat, largely responsible for its nutritive value, is related to changes in protein concentrations in samples resulting from weight loss during cooking. The highest nutritive value was noted in respect of the product roasted at a temperature of 200 °C with 20% steam saturation. Both optimal products were microbiologically safe.     

REPRESENTATION OF CYCLIC PROPERTIES OF AUSTENITIC STEELS WITH PLASTICITY-INDUCED MARTENSITIC TRANSFORMATION

This study is part of a wider research project on the cyclic properties, energy cumulation and fatigue life of metastable austenitic steels undergoing a martensitic transformation induced by plastic straining.
This paper considers the representation of the σ–ε hysteresis loop over a wide range of strain. A novel, power-function model of cyclic elastic–plastic material behaviour was used. The model allows the occurrence of a cyclic yield point and the characteristic inflection point of the CSS curve, which separates the single-phase (austenite) region from the two-phase (austenite + martensite) one. The plastic strain corresponding to the inflection point is assumed to be a material constant and is termed the martensitic transformation cyclic limit ε1 . The generalization of the model made possible the representation of cyclic softening of the two-phase material.
In addition, the study chose a measurement technique that assisted the estimation of the cyclic plastic strain (ε1 ) inducing the martensitic transformation. The crossed magnetomechanical (Villari) effect was shown to be applicable in detecting the nucleation and estimating the increase of the α'-martensite content.
The identification was performed making use of experimental results obtained from an AISI 304 high nickel content steel. The tests were performed under both increasing and constant plastic strain amplitude. The measured quantities were: total strain εt elastic strain εe , plastic strain εp , stress σ and hysteresis loop area ΔW. The results justify the assumed model.     

Optimization by full factorial design of the emulsifying properties of ethanol insoluble fraction from rapeseed lecithin

Rapeseed lecithin ethanol insoluble fraction (LEIF), was acetylated and optimum conditions for improving LEIF emulsifying property were determined. The effects of reaction time, pyridine amount and temperature on phosphatidyl ethanolamine conversion degree (PECD) and emulsion stability index (ESI) have been described in the form of regression equations. A full factorial design method was used. Regression equations for the maximum value of response functions and computation results were calculated and compared with those obtained in control experiments. Acetylation of rapeseed LEIF with the use of calculated optimal parameters led to 35% and 60% increments in PECD and ESI, respectively.     

New Nb-containing SBA-3 mesoporous materials—Synthesis, characteristics, and catalytic activity in gas and liquid phase oxidation

The synthesis and characterization of NbSBA-3 mesostructured materials – the first hexagonally ordered mesoporous molecular sieves without extra framework Nb-oxide phase – are described in this paper. The effect of the synthesis medium (basic or acidic) and Nb source in the efficiency of niobium incorporation is discussed. A higher Nb content in the final material is reached when Nb(V) chloride is used instead of Nb(V) ammonium trisoxalate complex in the synthesis. All NbSBA-3 materials prepared in this work are very attractive catalysts in ODH of propane and epoxidation of cyclohexene and more effective than the corresponding NbMCM-41 and NbSBA-15 catalysts.     

Studies on an argon laser-induced photopolymerization employing both mono- and bischromophoric hemicyanine dye–borate complex as a photoinitiator: Part II

Several photoredox pairs containing dichromophoric hemicyanine dyes have been evaluated as novel photoinitiators for free radical polymerization induced with an argon-ion laser irradiation. The tested photoredox couples are the pairs composed of the hemicyanine dye cations acting as electron acceptors and n-butyltriphenyl borate anions being the electron donors. The photoinitiating abilities of the series of dimmeric dichromophoric stilbazolium borates; 1,2-; 1,3-; and 1,4-bis-[4-(p-N,N-dialkylaminostyryl)pyridinyl]xylene di-n-butyltriphenylborates, were compared to the photochemistry of structurally related, monochromophoric styrylpyridinium borates. The obtained results clearly documented that the dicationic photoinitiators exhibit a marked increase in the photoinitiation ability compared to the initiators consisting of a single charged hemicyanine dye.Our studies revealed also that the rate of photopolymerization depends on ΔG_el of electron transfer between borate anion and styrylpyridinium cation. The latter value was estimated for all series of styrylpyridinium borate salts. The relationship between the rate of polymerization and the free energy of activation shows the dependence predicted by the classical theory of electron transfer.     

Use of the subcutaneous venous network of the forearm to create an arteriovenous fistula

The reconstruction of vascular access in patients with kidney allograft failure is a challenging problem. A case of a 62‐year‐old man with transplanted kidney insufficiency is described. The patient was initially dialyzed with a wrist radial‐cephalic arteriovenous fistula. In the post‐transplantation period, the enormously dilated venous part of the anastomosis was ligated and the part of the vein suspected of being the source of bacteremia was excised. The man was referred to our department due to kidney allograft failure for vascular access creation. During preoperative assessment, we unexpectedly found a soft thrill on the forearm. Doppler ultrasound confirmed fistula patency, although the blood supply was not sufficient to perform dialysis. Angiography showed the blood flow from the radial artery to the cephalic vein, through a complicated vessel system consisting of inter alia a dilated vein of the subcutaneous venous network. We successfully used this vein as the vascular access outflow for fistula recreation. In conclusion, making use of veins of the subcutaneous venous network of the forearm for creation of a native fistula should be considered in selected cases.     

Tin-based “super-POSS” building blocks in epoxy nanocomposites with highly improved oxidation resistance

A novel tin-based POSS analogue, butylstannoxane dodecamer, was incorporated as chemically active nanofiller in epoxy resins and achieved a considerable anti-oxidative activity already near 0.05 wt% and very high activity near 1 wt%. The amino-functional nanofiller, which bonds as a linear segment, displayed a high reactivity towards the resin components during cure and was very poorly extractable. Interestingly, at elevated temperatures, the stannoxane nanofiller, whose functional substituents are attached by ionic bonds, displays a considerable short-range mobility in the matrix, and in course of a nano-phase-separation process, rearranges and polymerizes to needle-like nano-domains. This effect leads to additional crosslinking in the nanocomposite. This “solid-phase nano-precipitation” does not occur under oxidative conditions, where the nanofiller preferentially undergoes crosslinking with matrix chains and is thereby immobilized. Nanocomposite synthesis, characterization and the concentration dependence of the nanofiller effect are presented.     

Application of gas chromatography–olfactometry (GC–O) in analysis and quality assessment of alcoholic beverages – A review

In recent years, intensive studies have been carried out regarding the sensory activity of the individual components of the odours of various alcoholic beverages and the dependence between the odour and the chemical composition of the volatile fraction of these products, using gas chromatography with olfactometric detection (GC–O). GC–O is a technique based on sensory evaluation of the eluate from the chromatographic column. Quantitative and qualitative odour evaluation is possible thanks to the presence of a specially constructed attachment, a so-called olfactometric port.     

Importance of palladium dispersion in Pd/Al2O3 catalysts for complete oxidation of humid low-methane–air mixtures

The catalytic oxidation is considered as an environmental benign method for utilization of various methane-poor gas mixtures, including humid post-ventilation air of coal mines. The small crystallites of palladium phase in the Pd/Al₂O₃ catalyst decrease temperatures necessary to ignite the methane oxidation reaction and to achieve complete conversion of methane. The isotopic exchange of oxygen between the catalyst and the gas phase, the temperature-programmed reduction (TPR) with methane and the X-ray photoelectron spectroscopy studies suggest that it can result from a higher number of the Pd–PdO sites present on the catalysts with small palladium crystallites. The inhibiting effect of water vapour present in the reaction mixture increases with lower dispersion of palladium phase as well as with the water concentration in the feed. The larger palladium crystallites are more significantly affected by the presence of water. It is suggested that water vapour blocks the Pd–PdO active sites. The catalysts with small crystallites (<6.6 nm) of palladium can be successfully used for mitigation of the emission of methane from coal mine post-ventilation air and, after increasing of the methane concentration to 1–2 vol.%, for its utilization for the energy production. In the case of such catalysts even a high concentration of water vapour has the least negative influence on the catalyst activity and it will not interfere with obtaining of the 100% conversion of methane below 650 °C.