Thermal imaging application in chronic venous disease

Thermal imaging was used for the estimation of lower-limb primary chronic venous diseases connected with an insufficiency of superficial veins. The current study was performed by means of a Thermovision A40 camera. The curves of the chosen regions of interest were performed in a research room with a stabilized temperature. Curves of the lower extremities showed that the patients suffered from a venous insufficiency characterized by a higher skin temperature connected with pathological changes in the veins. Changes seen in the lower extremities skin thermal map may be associated with blood stasis, inflammatory states and swelling. The differences in temperature distribution are due to a correlation between the medical diagnosis and the parameters obtained from duplex scanning. The results of the thermal imaging showed differences between patients’ health may suggest that a thermovision of lower extremities venous diseases can be very useful in medical diagnosis. The correlation was obtained from temperature parameters and duplex scanning. The parameters may suggest that thermovision diagnostics may be useful as a complementary method in the diagnosis of chronic venous diseases in the lower extremities.     

Studies on Pyrazine Derivatives,XLVI: The Synthesis of New Pyrazine Derivatives with N′-(Pyrazine-2-carbonyl)-hydrazinecarbodithioic Acid Methyl Ester Usage

4-Ω-alkylsubstituted derivatives of 1,2,4-triazole-2-thiones 2–7 were obtained using the high reactivity of N′-(pyrazine-2-carbonyl)-hydrazinecarbodithioic acid methyl ester 1 towards amines. In the reaction with cysteamine 1,3-thiazaethylene-1,2,4-triazole 8 formed. Aromatic amines and N-aminocycloalkylamines gave thiosemicarbazide derivatives 9–12 under the same conditions. The solution of sodium hydroxide caused the decomposition of compounds 11 and 12 and resulted in 4-piperidino- and 4-morpholino-thiosemicarbazides 13 and 14. Compounds 11 and 12 were cyclized to appropriate 4-substituted 1,2,4-triazole-2-thiones 16 and 17 under the influence of DBU or potassium carbonate solution. The heating of derivative 12 with sulfuric acid led to disubstituted 1,3,4-thiadiazole 18.     

Studies on Pyrazine Derivatives,XLIV: Synthesis and Tuberculostatic Activity of 4-Substituted 3,4,5,6-Tetrahydro-2H-[1,2′]-Bis-Pyrazine Derivatives

2-chloro-3-cyanopyrazine was a substrate in the syntheses of some potentially tuberculostatic pyrazine derivatives. This compound, upon action of secondary amines, pyrazine derivatives 1-phenyl-, 1-piperonyl-, 1-(4-fluorophenyl)-, 1-(2-pyridil)-, and 1-benzylpiperazine, gave the corresponding nitriles ( 1a–e ). Compounds 1c , d , e were changed into the amidoximes ( 2c , d , e ) by hydroxylamine action. Derivatives 1a–e were transformed into the corresponding thioamides ( 3a–e ) when treated with ammonium polysulphide. Two of these, thioamides, 3a and 3b , in the cyclization reactions with ethylenediamine gave the imidazolines ( 4a , b ) with phenacyl bromide—the thiazole derivatives ( 5a , b ). The compounds obtained were tested in vitro for their tuberculostatic activity. The tuberculostatic activity of compound 5b was the highest: MIC 3.1–7.8 μ g/mL.     

Solid-to-solid Reaction of 2,4-Dinitrophenylhydrazine with Several Aromatic Aldehydes Bearing Electron-donating Groups

Abstract

Aromatic 2,4-dinitrophenylhydrazones are conveniently prepared from 2,4-dinitrophenylhydrazyne and the corresponding aldehydes bearing electron-donating groups [N(Me)₂, OMe and OH] in non-solvent reactions. The high-dilution method in the absence of basic or acidic catalysts is also efficient. According to X-ray data, planar conformation of the hydrazone molecules is stabilized by intramolecular NH…O₂N hydrogen bond. Formation of 2D networks in the crystal is mediated via intermolecular CH…O₂N hydrogen bonds.     

Comparison of polymeric and ceramic membranes performance in the process of micellar enhanced ultrafiltration of cadmium(II) ions from aqueous solutions

A comparison of polymeric and ceramic membranes in the ultrafiltration process was studied and presented. This study was conducted on the separation of cadmium(II) ions, with particular reference to parameters such as hydrodynamic permeability coefficient, membrane fouling, amount of surfactant in the permeate, efficiency, and effectiveness of the process. The effect of ionic (SDS) and non-ionic (Rofam 10) surfactants or their mixture was investigated. The hydrodynamic permeability coefficient of the ceramic membrane was found to be much lower in comparison to those of the polymeric ones (1.69 × 10^?7 m³ h^?1 m^?2 Pa^?1, 5.66 × 10^?7 m³ h^?1 m^?2 Pa^?1, and 9.26 × 10^?7 m³ h^?1 m^?2 Pa^?1 for ceramic, CA, and PVDF, respectively). However, filtration of the surfactants solutions did not cause permanent blocking of pores and the surface of the ceramic membrane in contrast to the polymeric ones. No significant differences in surfactants permeation through the membranes tested were observed. Concentration of the surfactant in the permeate was lower than 1 CMC for the Rofam 10 solution and exceeded the CMC by about 40 % for the SDS solution. Better separation properties of polymer membranes for the separation of cadmium(II) ions from micellar systems were identified.     

Synthesis of 2,3‐Dihydroxy‐1‐Epilupinine

The 1,3‐dipolar cycloaddition of unsaturated D‐threo‐hexaldonolactone 3 and a six‐membered cyclic nitrone 11 led to a single adduct 15, which could be transformed into (1S, 2S, 3S, 9aS)‐2,3‐dihydroxy‐1‐hydroxymethyl‐quinolizidine 28 related to epilupinine via a reaction sequence involving rearrangement of the six‐membered lactone ring into a five‐membered one, removal of the terminal carbon atom from the sugar chain, cleavage of the N‐O bond, and the intramolecular alkylation of the nitrogen atom.      

Mechanism of photochemical reduction of chromium(VI) by alcohols and its environmental aspects

The idea of photochemical abatement of the Cr(VI) pollution has been verified by investigating the photoreduction mediated by aliphatic alcohols under conditions mimicking the environmental ones. Effects of the alcohol nature, pH and presence of oxygen are analysed. The time-resolved spectra are used to follow the generation of the transient chromium Cr(V), Cr(IV) and Cr(II) species and the R₁R₂CHOH√⁺ radicals. A direct interaction between chromate(VI) and an electron donor is a precondition of the photoreduction via the photoinduced electron transfer (PET). Two pathways of the PET are identified: one-electron transfer for intermolecular and two-electron transfer for the intramolecular systems. In the case of the alcohol mediators the option is pH-controlled.     

The photoinduced isomerization and its implication in the photo-dynamical processes in two simple Schiff bases isolated in solid argon

Two Schiff bases: 2-(1-(methylimino)methyl)-phenol (SMA) and its chlorosubstituted derivative 2-(1-(methylimino)methyl)-6-chlorophenol (SMAC), and SMA complexes with water were studied by infrared matrix isolation spectroscopy and DFT/B3LYP/6-311G++(2d,2p) quantum chemical calculations. SMA and SMAC bases trapped in an argon matrix from the vapor above the liquid and solid samples have the most stable enol conformation with intramolecular O-H···N bonding. Irradiation (λ > 320 nm) leads in both bases to a rotational isomerization reaction in which the scission of the O-H···N bond occurs and the C(H)NCH(3) and OH groups are turned by 180° around the C-C and C-O bonds, respectively. In SMAC a competitive photoreaction channel yields the trans-keto tautomer. The identification of the two SMAC photoproducts evidences that in the excited enol form of this compound two processes compete with each other: the rotational isomerization and intramolecular proton transfer (ESIPT). In the argon matrices doped with SMA and H(2)O the SMA-water complexes were identified and characterized spectroscopically. Interaction of SMA with one or two water molecules does not affect the photochemistry of SMA.