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Abstract  

Four new mixed ligand complexes were prepared by the reaction of title metal dichloroacetates and 2,4'-bipyridine. The general formulae of synthesized compounds are M(2,4'-bpy)2(CCl2HCOO)2 nH2O (where M(II)=Mn, Co, Ni, Cu; 2,4'-bpy=2,4'-bipyridine, n=2 or 4). The complexes have been isolated from aqueous media and characterized by chemical analysis, molar conductance (in MeOH, DMSO and DMF), magnetic, IR and VIS spectral studies. The nature of metal(II)-ligand coordination is discussed. The thermal behaviour of obtained complexes was studied by thermal analysis and TG-MS techniques in air. IR, X-ray powder diffraction and thermoanalytical data were used for the determination of solid intermediate products of the thermal decomposition. The principal volatile products of thermal decomposition of complexes were proved by mass spectroscopy: H2O+, CO+ 2, HCl+ 2, Cl+ 2, NO+ and other.

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The synthetic scope of photo-induced copper-mediated polymerization (photoCMP) in continuous-flow reactors is further explored. A series of monomers, namely, methyl (MA), ethyl (EA), n-butyl (nBA), 2-hydroxyethyl (HEA), and di(ethylene glycol) ethyl ether (DEGA) acrylate are investigated, all showing high livingness (dispersity in the range of 1.1 and linear first order kinetics) in the polymerizations and high conversions within 20-min reaction time. Next to the commonly used solvent (dimethyl sulfoxide [DMSO]), also a water—ethanol mixture was used as greener alternative, without any loss in reaction control. Upscaling the reactor from 2 to 16 mL allows for production of over 200 g of high-definition material (3000 g/mol, 1.1 dispersity) in overnight operation (18 h), demonstrating that the photoprocess can be run under very stable conditions even for extended reaction times. Via coupling of two reactors, direct chain extension of copolymers in a single reaction step is also demonstrated.

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Journal of Thermal Analysis and Calorimetry
Authors: K. Siimer, P. Christjanson, T. Kaljuvee, T. Pehk, I. Lasn, and I. Saks

Abstract  

The thermal behaviour of MUF resins from different suppliers with different content of melamine was studied, along with the 13C NMR spectroscopic analysis of resin structure and the testing of particleboards in current production at Estonian PB factory Pärnu Plaaditehas AS. The chemical structure of resins from DMSO-d6 solutions was analysed by 13C NMR spectroscopy on a Bruker AMX500 NMR spectrometer. The melamine level in different MUF resins is compared by the ratios of carbonyl carbon of urea and triazine carbon of melamine in 13C NMR spectra. Curing behaviour of MUF resins was studied by stimultaneous TG-DTA techniques on the Labsys™ instrument Setaram. The shape of DTA curves characterisises the resin synthesis procedure by the extent of polymerisation of UF and MF components and is in accordance with structural data.

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Abstract  

A combined analysis of structural data and experimental results (DSC, temperature-resolved XRPD and hot stage optical microscopy) revealed that the dehydration mechanism of cortisone acetate monohydrate (CTA·H2O) involves a collective and anisotropic departure of water molecules followed by a cooperative structural reorganization toward the anhydrous polymorph CTA (form 2). In spite of the lack of crystal structure data, it can be postulated from experimental data that thermal decomposition of the dihydrated form (CTA·2H2O) and of the tetrahydrofuran solvate (CTA·THF) toward another polymorph (CTA (form 3)) also proceeds according to a cooperative mechanism, thus giving rise to probable structural filiations between these crystalline forms of CTA. The crystal structure determination of two original solvates (CTA·DMF and CTA·DMSO) indicates that these phases are isomorphous to the previously reported acetone solvate. However, their desolvation behaviour does not involve a cooperative mechanism, as could be expected from structural data only. Instead, the decomposition mechanism of CTA·DMF and CTA·DMSO starts with the formation of a solvent-proof superficial layer, followed by the partial dissolution of the enclosed inner part of crystals. Hot stage optical microscopy observations and DSC measurements showed that dissolved materials (resulting from a peritectic decomposition) is suddenly evacuated through macroscopic cracks about 30°C above the ebullition point of each solvent. From this unusual behaviour, the necessity to investigate rigorously the various aspects (thermodynamics, kinetics, crystal structures and physical factors) of solvate decompositions is highlighted, including factors related to the particular preparation route of each sample.

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Absztrakt

A daganatos betegek kezeléséhez a kemoterápiás kezelések által kiváltott különböző mukokután reakciók társulhatnak. Az egyik ilyen mukokután mellékhatás a beadás helyén jelentkező toxikus szöveti reakció, az extravazáció, mely az összes citotoxikus infúzió kevesebb mint 1-2%-ában fordul elő. A hólyaghúzók által okozott extravazáció standard ellátása a következő: le kell állítani az infúziót, vissza kell szívni a gyógyszert, fel kell polcolni a végtagot, hűtést vagy éppen meleg kötést kell alkalmazni, helyi érzéstelenítést lehet végezni, antidotumokat kell adni (alkilező szerek esetén Na-tioszulfát, anthracyclinek és mitomycin esetén dimetilszulfoxid (DMSO), vinca-alkaloidák esetén hialuronidáz jön szóba), végső esetben viszont sebészi eltávolítás és plasztikai rekonstrukció szükséges. Mivel az anthracyclinek topoizomeráz II-mérgek, hatásukat a topoizomeráz II katalitikus gátlója (a dexrazoxan) antagonizálja, ezért a doxorubicin, epirubicin, daunorubicin stb. extravazációja esetén a dexrazoxan azonnali használata látszik a választandó kezelésnek. Az esemény után azonnal beadott egyetlen szisztémás dexrazoxan-adag jelentősen csökkentheti a toxikus szöveti károsodást. GM-CSF-injekciók ismételt intralézionális adása meggyorsíthatja a sebgyógyulást és elkerülhető a bőrpótlás.

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The intermediates formed from Mo(NO)2Cl2 L 2 and Mo(NO)Cl3 L 2 by splitting-off of weakly-coordinated ligandsL (alcohols, glycols, nitriles) decompose in exothermic reactions: the decomposition products are N2, MoOCl4 and MoO3. If the ligandL is strongly coordinated and is reducing (DMFA, DMSO, Pph3, Asph3), the NO groups oxidize the ligandL by formation of N2 in an exothermic intramolecular redox process under 300‡. The central atom is oxidized by NO, and N2O is formed above 300‡ in the case of non-reducing ligandsL (OPph3, OAsph3). An endothermic redox reaction with chlorine formation is observed during decomposition of the trichloro complex. The solid residue is metallic molybdenum.

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Cereal Research Communications
Authors: L. Brindzová, M. Zalibera, T. Jakubík, M. Mikulášová, M. Takácsová, S. Mošovská, and P. Rapta

This study examined the mutagenic, antimutagenic and antioxidant activities of the DMSO extracts from the wheat bran. Wheat bran extracts showed no genotoxicity toward Salmonella typhimurium TA98, TA100 and TA102 with or without S9 mix (an external metabolic system). In addition, wheat bran extracts expressed a dose-depend inhibitory effect on the mutagenicity of promutagen aflatoxin B1 (AFB1), an indirect mutagen which requires metabolic activation, and 3-(5-nitro-2-furyl)acrylic acid (5-NFAA), 2-nitrofluorene (2NF) and hydrogen peroxide (H 2 O 2 ), direct mutagens, in Salmonella typhimurium TA98, TA100 and TA102 strains. Significant total antioxidant capacity of wheat bran extract was found by two standard spectroscopic assays based on ABTS and DPPH reagents. A special attention was focused to the reactive radical scavenging capacity of bran extract as one of its antioxitant activities. Wheat bran extract possessed higher ability to scavenge oxygen- and carbon-centered reactive radicals generated by the thermal decomposition of K 2 S 2 O 8 than BHT (70 and 65% scavenged radicals, respectively) during the electron paramagnetic resonance (EPR)/spintrapping test. The total phenolic content of wheat bran samples expressed in gallic acid equivalent was 2.7 mg/g, total flavonoid content expressed in rutin equivalent was 70.8 μg/g and the most abundant phenolic acids established by GC-MS method were isoferulic (3-hydroxy-4-metoxycinnamic) and ferulic (4-hydroxy-3-metoxycinnamic) acid, sinapic, caffeic, p -coumaric and vanillic acids.

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Abstract  

Aromatic polyamides find many applications in diverse and critical areas due to their high thermal stability coupled with high mechanical properties. However most of such aramides are difficult to fabricate because of their limited solubility and high melting temperature. Improvements in processability have been reported by incorporating bulky pendant groups and aliphatic spacer groups. Similarly to improve the solubility of polymers approaches of incorporating silicon in main polymer chain and co-polymerization techniques were useful. We report the synthesis and characterization of a series of phenylated silicon containing aromatic–aliphatic polyamides from a mixture of 2, 5-bis (4-carboxy methylene phenyl)-3, 4-diphenyl thiophene (CMPDT) and bis-(4-carboxy phenyl) dimethyl silane (BCPDS) in various mole proportions, with commercial aromatic diamine. Thus a series of novel co-polyamides having pendant phenyl groups, methylene spacer and silicon moiety was prepared by judicious combination of (CMPDT); BCPDS and aromatic diamine; bis-(4-aminophenyl) ether (ODA), by direct polycondensation using Yamazaki’s phosphorylation method. These high molecular mass polyamides were obtained in high (89–98%) yields and had viscosities in the range of 0.23–0.57 dL/g in DMAc. Polyamides showed improved solubility in polar aprotic solvents, like NMP, DMAc, DMSO and DMF; had high thermal stability; with no mass loss below 335 °C.

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Abstract  

The need of reliable production of N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB), a versatile 18F-labeled prosthetic group for protein labeling, has increased dramatically due to the easy availability of proteins or their engineered derivatives for targeted molecular imaging. A module-assisted radiosynthesis of [18F]SFB was developed using a three-step, one-pot procedure and ethyl 4-(trimethylammonium)benzoate triflate (1) as the starting material. The radiochemical transformations were carried out in a general-purpose, custom-made module and streamlined by an anhydrous deprotection strategy using t-BuOK/DMSO. After HPLC-purification, [18F]SFB was synthesized in radiochemical yields of 20–30% (n > 10, not decay-corrected) and excellent radiochemical and chemical purities (>98%). The total synthesis and purification time required is ~90 min. Using the purified [18F]SFB, three 18F-labeled proteins, bovine serum albumin (BSA), chicken egg albumin (CEA) and transferrin, were synthesized in yields of 61.0–79.5%. The 18F-Annexin V for apoptosis imaging was also produced in 5% radiolabeling yield and >95% radiochemical purity.

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Abstract  

New mixed-ligands complexes with empirical formulae: M(2,4′-bpy)2L2�H2O (M(II)Zn, Cd), Zn(2-bpy)3L2�4H2O, Cd(2-bpy)2L2�3H2O, M(phen)L2�2H2O (where M(II)=Mn, Ni, Zn, Cd; 2,4′-bpy=2,4′-bipyridine, 2-bpy=2,2′-bipyridine, phen=1,10-phenanthroline, L=HCOO) were prepared in pure solid state. They were characterized by chemical, thermal and X-ray powder diffraction analysis, IR spectroscopy, molar conductance in MeOH, DMF and DMSO. Examinations of OCO absorption bands suggest versatile coordination behaviour of obtained complexes. The 2,4′-bpy acts as monodentate ligand; 2-bpy and phen as chelating ligands. Thermal studies were performed in static air atmosphere. When the temperature raised the dehydration processes started. The final decomposition products, namely MO (Ni, Zn, Cd) and Mn3O4, were identified by X-ray diffraction.

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