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91.
92.
Antoni Augustynowicz 《Rendiconti del Circolo Matematico di Palermo》1998,47(1):99-105
We consider a homogeneous boundary value problem for a linear partial differential-functional equation of elliptic type. We
prove the existence of a unique solution to such problem in a Sobolev space. 相似文献
93.
Oliva AI Christmann U Font D Cuevas F Ballester P Buschmann H Torrens A Yenes S Pericàs MA 《Organic letters》2008,10(8):1617-1619
The synthesis of novel tricyclic 1,2,3-triazoles starting from cyclic epoxides via the sequential azidolysis, propargylation and 1,3-dipolar cycloaddition is described. Derivatization by N-arylation reaction and the synthesis of enantiomerically pure compounds is also reported. Some of these compounds exhibit significant affinity for the sigma-1 receptor. 相似文献
94.
Dr. Andreas Eitzinger Justus Reitz Patrick W. Antoni Prof. Dr. Herbert Mayr Dr. Armin R. Ofial Jun.-Prof. Max M. Hansmann 《Angewandte Chemie (International ed. in English)》2023,62(40):e202309790
A series of mesoionic, 1,2,3-triazole-derived N-heterocyclic olefins (mNHOs), which have an extraordinarily electron-rich exocyclic CC-double bond, was synthesized and spectroscopically characterized, in selected cases by X-ray crystallography. The kinetics of their reactions with arylidene malonates, ArCH=C(CO2Et)2, which gave zwitterionic adducts, were investigated photometrically in THF at 20 °C. The resulting second-order rate constants k2(20 °C) correlate linearly with the reported electrophilicity parameters E of the arylidene malonates (reference electrophiles), thus providing the nucleophile-specific N and sN parameters of the mNHOs according to the correlation lg k2(20 °C)=sN(N+E). With 21<N<32, the mNHOs are much stronger nucleophiles than conventional NHOs. Some mNHOs even excel the reactivity of mono- and diacceptor-substituted carbanions. It is exemplarily shown that the reactivity parameters thus obtained allow to calculate the rate constants for mNHO reactions with further Michael acceptors and predict the scope of reactions with other electrophilic reaction partners including carbon dioxide, which gives zwitterionic mNHO-carboxylates. The nucleophilicity parameters N correlate linearly with a linear combination of the quantum-chemically calculated methyl cation affinities and buried volumes of mNHOs, which offers a valuable tool to tailor the reactivities of strong carbon nucleophiles. 相似文献
95.
Sala X Poater A von Zelewsky A Parella T Fontrodona X Romero I Solà M Rodríguez M Llobet A 《Inorganic chemistry》2008,47(18):8016-8024
A new set of Ru-Cl complexes containing either the pinene[5,6]bpea ligand (L1) or the C3 symmetric pinene[4,5]tpmOMe (L2) tridentate ligand in combination with the bidentate (B) 2,2'-bipyridine (bpy) or 1,2-diphenylphosphinoethane (dppe) with general formula [RuCl(L1 or L2)(B)](+) have been prepared and thoroughly characterized. In the solid state, X-ray diffraction analysis techniques have been used. In solution, cyclic voltammetry (CV) and 1D and 2D NMR spectroscopy have been employed. DFT calculations have been also performed on these complexes and their achiral analogues previously reported in our group, to interpret and complement experimental results. Whereas isomerically pure complexes ([Ru(II)Cl(L2)(bpy)](BF4), 5 and [Ru(II)Cl(L2)(dppe)](BF4), 6) are obtained when starting from the highly symmetric [Ru(III)Cl3(L2)], 2, isomeric mixtures of cis, fac-[Ru(II)Cl(L1)(bpy)](BF4) (3b/3b'), trans,fac- (3a) and up/down,mer- (3c, 3d) isomers are formed when bpy is added to the less symmetric [Ru(III)Cl3(L1)], 1, in contrast to the case of the bulky dppe ligand that, upon coordination to 1, leads to the trans,fac-[Ru(II)Cl(L1)(dppe)](BF4) (4a) complex as a sole isomer due to steric factors. 相似文献
96.
An automatic system based on multisyringe flow injection analysis (MSFIA) and lab-on-valve (LOV) flow techniques for separation and pre-concentration of 226Ra from drinking and natural water samples has been developed. The analytical protocol combines two different procedures: the Ra adsorption on MnO2 and the BaSO4 co-precipitation, achieving more selectivity especially in water samples with low radium levels. 相似文献
97.
Electric field modulation in tissue electroporation with electrolytic and non-electrolytic additives
Electroporation, cell membrane permeabilization with short electrical field pulses, is used in tissue for in vivo gene therapy, drug therapy and minimally invasive tissue ablation. For the electroporation to be successful, the electrical field that develops during the application of the pulses needs to be precisely controlled. In this study we investigate the use of electrolytic and non-electrolytic gels to generate the precise electrical fields required for controlled electroporation, in heterogeneous and irregular tissues, in vivo. Finite element computer simulations are used to illustrate various applications, such as the treatment of irregularly shaped organs and interior cavities. The feasibility of the concept is demonstrated experimentally in vivo with a rat liver subjected to irreversible electroporation. 相似文献
98.
Electroporation is used for in vivo gene therapy, drug therapy and minimally invasive tissue ablation. Applying electrical pulses across cells can have a variety of outcomes; from no effect to reversible electroporation to irreversible electroporation. Recently, it has been proposed that measuring the passive electrical properties of electroporated tissues could provide real time feedback on the outcome of the treatment. Here we describe the results from the impedance characterization (single dispersion Cole model) for up to 30 min of the electroporation process in in vivo rat livers (n=8). The electroporation sequence consisted of 8 pulses of 100 micros with a period of 100 ms. Half of the animals were subjected to field magnitudes considered to have reversible effects (R group, E=450 V/cm) whereas for the other half irreversible field amplitudes were applied (I group, E=1500 V/cm). As expected, there was an immediate increase of conductivity (R group Deltasigma/sigma(t=0)=9+/-3%; I group Deltasigma/sigma(t=0)=43+/-1%). However, the overall long term pattern of change in conductivity after electroporation is complex and different between reversible and irreversible groups. This suggests the superposition of different phenomena which together affect the electrical properties. 相似文献
99.
100.
Consumption of non-steroidal anti-inflammatory drugs (NSAIDs) is increasing and with it the danger of environmental pollution
by pharmaceutical residues. Publications regarding NSAIDs in the environment not only show that they are toxic to many animal
species, but also highlight the need for robust analytical methods for monitoring the level of such contaminants in environmental
matrices. In our study we selected the four most widely used NSAIDs in Slovenia and Central Europe, ibuprofen, naproxen, ketoprofen
and diclofenac, and studied their extraction from sediment samples. We examined several extraction techniques (ultrasonic
extraction, Soxhlet extraction, pressurized liquid extraction, supercritical fluid extraction and microwave-assisted extraction)
using a spiked sediment sample and determined optimal extraction conditions. After extraction we applied a clean-up step,
derivatisation of the analytes and gas chromatography with mass spectrometric detection (GC-MSD) and selected the most appropriate
extraction procedure. The optimised analytical method chosen for analysis of sediment samples consisted of microwave-assisted
extraction, clean-up of the extract with SPE, derivatisation with MSTFA and determination with GC-MSD. The optimised procedure
was applied to the analysis of two environmental river samples taken from the vicinity of Novo mesto, the biggest town in
the south eastern part of Slovenia with 62,000 inhabitants, a hospital and a pharmaceutical factory in its vicinity. While
analysis of the sample taken upstream of the town showed no detectable amounts of NSAIDs, analysis of samples taken downstream
showed quantifiable levels of two of the studied NSAIDs (naproxen and ketoprofen). Besides these two NSAIDs, river water samples
sampled at the same time and location on the River Krka also showed the presence of diclofenac. Sampling on the River Krka
and other Slovene rivers will in the future be repeated at different sampling points in order to track down the main sources
of pollution. 相似文献