Blood oxygenation monitoring using hyperspectral imaging after flap surgery

In this paper, we present a new method for the assessment of skin flap perfusion based on the non-invasive monitoring of skin blood oxygenation using hyperspectral imaging. This method consists of generation of oxyhemoglobin and deoxyhemoglobin maps in skin flap from hyperspectral image using an analytic model based on Beer–Lambert law. The results obtained on a fasciocutaneous sural flap have revealed that the oxyhemoglobin and deoxyhemoglobin maps facilitate the visualization of some differences between different areas of the flap, an aspect that clinical examination fails to do. In conclusion, the proposed method could provide a new option for a more accurate assessment of flap survival.     

Almost Global Existence for the Prandtl Boundary Layer Equations

We consider the Prandtl boundary layer equations on the half plane, with initial datum that lies in a weighted H¹ space with respect to the normal variable, and is real-analytic with respect to the tangential variable. The boundary trace of the horizontal Euler flow is taken to be a constant. We prove that if the Prandtl datum lies within \({\varepsilon}\) of a stable profile, then the unique solution of the Cauchy problem can be extended at least up to time \({T_{\varepsilon} \geqq {\rm exp}(\varepsilon^{-1} / {\rm log}(\varepsilon^{-1}))}\).     

Spectroscopic evaluation of painted layer structural changes induced by gamma radiation in experimental models

The degradation of cultural heritage objects by insects and microorganisms is an important issue for conservators, art specialists and humankind in general. Gamma irradiation is an efficient method of polychrome wooden artifacts disinfestation. Color changes and other modifications in the physical chemical properties of materials induced by gamma irradiation are feared by cultural heritage responsible committees and they have to be evaluated objectively and precisely. In this paper FTIR and FT-Raman spectroscopy methods were used to investigate the structural changes in some experimental models of tempera paint layers on wood following 11 kGy gamma irradiation at two dose rates. Radiation chemistry depends on the particular pigment, matrix formed by protein, resin (in case of varnished samples) and water presence. For the majority of painted layer in experimental models very small spectral variations were observed. Small changes in the FTIR spectra were observed for the raw sienna experimental model: for the higher dose rate the egg yolk protein oxidation peaks and the CH stretching bands due to lipids degradation products increased.     

Modelling of sorbic acid diffusion through bacterial cellulose-based antimicrobial films

Antimicrobial packaging protects the product from the external environment and microbial contamination, conferring numerous advantages on human health. Interest in biopolymers as packaging materials has considerably increased recently. Bacterial cellulose is an interesting biomaterial produced as nanofibrils by Acetobacter xylinium and is a promising candidate due to its remarkable properties. New composite materials with antimicrobial properties were developed in this work, containing poly(vinyl alcohol) (PVA) as polymer matrix and ground bacterial cellulose (BC) as reinforcing fibres. Sorbic acid was used as an antimicrobial agent because it is a preservative recognised in the food industry. The materials obtained were studied using Fourier-transformed infrared spectroscopy (FTIR). The swelling rate of the composites was also measured. Release experiments of sorbic acid from the composite films into water were performed and the mass transfer phenomena were investigated using Fick’s law of diffusion. The antimicrobial effect was tested against Escherichia coli K12-MG1655. The results obtained indicated that the new biocomposite films could be promising antimicrobial food packaging materials.     

Electronic Properties-Morphology Correlation of a Rod-Rod Semiconducting Liquid Crystalline Block Copolymer Containing Poly(3-hexylthiophene)

The influence of the solvent and annealing temperature on the field-effect mobilities and morphologies of poly(3-hexylthiophene)-b-poly(γ-benzyl-l-glutamate) (P3HT-b-PBLG) rod-rod diblock copolymer has been investigated. Thin film X-ray diffraction studies show peaks originating from both P3HT and PBLG indicating that the crystalline nature of both the blocks is conserved after the formation of the block copolymer. It has been observed that the field-effect mobilities of the diblock copolymer are independent of the annealing temperatures for thin films deposited from both 1,2,4-trichlorobenzene and chloroform solvents. The correlation between the field-effect mobility and morphology indicates that the P3HT block self-assembles at the surface SiO(2) dielectric.     

Synthesis and characterization of some vanadyl complexes with flavonoid derivatives as potential insulin-mimetic agents

Two new complexes with formula VOL₂·nH₂O ((1) L: 4′,5,7-trihydroxyflavone-7-rhamnoglucoside (naringin), n = 8; (2) L: 3′,4′,7-tris[O-(2-hydroxyethyl)]rutin (troxerutin), n = 0) were synthesised and characterised. The IR and UV–Vis spectral data indicate that these flavones act as bidentate chelating ligands and generate VO(II) complexes with a square-pyramidal stereochemistry. The thermal analysis (TG, DTA) elucidated the composition and also the number and nature of the water molecules. The thermal behavior indicates also a strong interaction between oxovanadium (IV) and these oxygen donor ligands.     

Kinetics of exothermal decomposition of some ketone-2,4-dinitrophenylhydrazones

In this study, the thermal stability and exothermal decomposition of some ketone-2,4-dinitrophenylhydrazones have investigated using the DSC technique. The synthesized and purified crystalline solids are thermally stable and start to decompose after melting. Non-isothermal DSC curves, recorded at several heating rates, were used to evaluate the melting properties and the kinetics of thermal decomposition. The isoconversional and model-fitting methods were applied to determine the activation parameters from the common analysis of multiple curves measured at different heating rates. Based on the results of the model??free method, a kinetic model was derived, and the kinetic parameters were obtained by means of a multivariate nonlinear regression. The results are discussed in relation to the effect of the ketone structure.     

Morphological investigation of PP/nanosilica composites containing SEBS

The effect of styrene-(ethylene-co-butylene)-styrene triblock copolymer (SEBS) on the mechanical, thermal and morphological properties of polypropylene (PP) composites filled with nanosilica particles is investigated. A simultaneous increase of all tensile characteristics is observed in PP/nanosilica composites without SEBS and containing 5%SEBS and a large plastic deformation in the nanocomposite with 10%SEBS. Different amounts of β-PP are detected by X-ray diffraction analysis and the calculated K-values correlate well with differential scanning calorimetry results. Quantitative mechanical characterization of nanocomposites is performed at nanolevel, using peak force QNM. This AFM technique allows the detection of nanosilica particles and SEBS domains at the surface of samples and gives indications of local interactions between nanosilica and the matrix from the correlation of modulus and adhesion maps, and the increased local values of elastic modulus on extended areas around nanoparticles.     

Benzo[1,2‐b:4,5‐b′]dithiophene Building Block for the Synthesis of Semiconducting Polymers

This review covers the synthesis and polymerization of benzo[1,2‐b: 4,5‐b′]dithiophene (BDT) to generate semiconducting polymers used in organic field‐effect transistors (OFET) and organic solar cells applications.     

Radon levels assessment in some Northern Romanian salt mines

Due to their low radioactivity background, underground salt mines spaces offer a unique possibility for speleotherapy use. The knowledge of radon concentration levels in such underground environments is essential for therapeutic purposes of different respiratory and rheumatic diseases. In order to develop speleotherapy in Romania, this paper presents the results of an indoor radon concentration levels survey in some salt mines in Romania. The survey was carried out using radon monitor Pylon AB-5 system methodology validated by a CIS-P5M system. In order to investigate whether differences in depth and microclimate parameters translate into significant differences in salt mine indoor radon concentrations, have been chosen three salts mine test sites placed in the Northern part of Romania (Turda, Cacica and Ocna Dej) in stable areas of the mining field at 32?C120?m depth. Environmental microclimate conditions (mean values of air temperature 10?C14.5?°C, air humidity 65?C80%, air velocity 0.2?m/s saline aerosols and low microbial factors) have anti-bacterial, anti-microbial, and anti-inflammatory properties and recognized therapeutically effects on human body??s health. Air temperature is one of the most important factors which need to be considered when carrying out a survey of indoor radon concentrations in salt mines because temperature largely determines close spaces ventilation rates, and ventilation habits are known to have significant effects on indoor radon concentrations. The analyzed environmental conditions and recorded low levels of indoor mean radon concentration (6.9?±?0.39 and 96.5?±?4.76?Bq/m³) demonstrated the best suitability of the investigated three salt mines in Romania for speleotherapeutic applications.