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排序方式: 共有413条查询结果,搜索用时 15 毫秒
1.
Vasile M. Loots H. Vercammen L. Bruggeman M. Verrezen F. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(8):3349-3357
Journal of Radioanalytical and Nuclear Chemistry - In this paper a study for the selection of an NPE (nonylphenol ethoxylates)—free cocktail is discussed in order to be used for our routine... 相似文献
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Sergiu Aizicovici Nikolaos S. Papageorgiou Vasile Staicu 《Journal of Differential Equations》2007,243(2):504-535
We consider a nonlinear periodic problem driven by the scalar p-Laplacian with a nonsmooth potential (hemivariational inequality). Using the degree theory for multivalued perturbations of (S)+-operators and the spectrum of a class of weighted eigenvalue problems for the scalar p-Laplacian, we prove the existence of at least three distinct nontrivial solutions, two of which have constant sign. 相似文献
4.
Cimpeanu V Parvulescu VI Amorós P Beltrán D Thompson JM Hardacre C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(18):4640-4646
Heterogeneous catalytic oxidation of a series of thioethers (2-thiomethylpyrimidine, 2-thiomethyl-4,6-dimethyl-pyrimidine, 2-thiobenzylpyrimidine, 2-thiobenzyl-4,6-dimethylpyrimidine, thioanisole, and n-heptyl methyl sulfide) was performed in ionic liquids by using MCM-41 and UVM-type mesoporous catalysts containing Ti, or Ti and Ge. A range of triflate, tetrafluoroborate, trifluoroacetate, lactate and bis(trifluoromethanesulfonyl)imide-based ionic liquids were used. The oxidations were carried out by using anhydrous hydrogen peroxide or the urea-hydrogen peroxide adduct and showed that ionic liquids are very effective solvents, achieving greater reactivity and selectivity than reactions performed in dioxane. The effects of halide and acid impurities on the reactions were also investigated. Recycling experiments on catalysts were carried out in order to evaluate Ti leaching and its effect on activity and selectivity. 相似文献
5.
Vasile Dinoiu Bernard Tinant Jean-Philippe Bouillon 《Journal of fluorine chemistry》2006,127(1):101-107
The paper presents a one-pot conversion of γ-keto-α-pentafluoroethyl thioester into new pyridazin-3-ones and α,β-unsaturated lactams. The structures of all new compounds were ascribed using 1D (19F, 1H, 13C) and 2D (1H-15N) NMR data, and X-ray diffraction analysis. Two possible competitive reaction mechanisms for the synthesis of pyridazin-3-ones and lactams are presented. 相似文献
6.
W.E. Falconer G.R. Jones W.A. Sunder M.J. Vasile Annabel A. Muenter T.R. Dyke W. Klemperer 《Journal of fluorine chemistry》1974,4(2):213-234
Most known non-radioactive pentafluorides have been examined by molecular-beam mass spectrometry and by the deflection of molecular beams in inhomogeneous electric fields. Extensive association of the vapors occurs for all but the lighter pentafluorides and the interhalogens. The interhalogen pentafluorides are strongly polar, consistent with the accepted C4v symmetry. The transition-metal and Group V pentafluorides are all non-polar, except VF5 and CrF5 for which temperature-dependent polarity is observed. However, uncertainty exists as to whether these observations are applicable to monomeric pentafluorides in all cases. Mass-spectral cracking patterns are presented for all species. 相似文献
7.
New Chemotypes for the Inhibition of (p)ppGpp Synthesis in the Quest for New Antimicrobial Compounds
Crescenzo Coppa Luca Sorrentino Monica Civera Marco Minneci Francesca Vasile Sara Sattin 《Molecules (Basel, Switzerland)》2022,27(10)
Antimicrobial resistance (AMR) poses a serious threat to our society from both the medical and economic point of view, while the antibiotic discovery pipeline has been dwindling over the last decades. Targeting non-essential bacterial pathways, such as those leading to antibiotic persistence, a bacterial bet-hedging strategy, will lead to new molecular entities displaying low selective pressure, thereby reducing the insurgence of AMR. Here, we describe a way to target (p)ppGpp (guanosine tetra- or penta-phosphate) signaling, a non-essential pathway involved in the formation of persisters, with a structure-based approach. A superfamily of enzymes called RSH (RelA/SpoT Homolog) regulates the intracellular levels of this alarmone. We virtually screened several fragment libraries against the (p)ppGpp synthetase domain of our RSH chosen model RelSeq, selected three main chemotypes, and measured their interaction with RelSeq by thermal shift assay and STD-NMR. Most of the tested fragments are selective for the synthetase domain, allowing us to select the aminobenzoic acid scaffold as a hit for lead development. 相似文献
8.
Nicoleta E. Mircescu Haibo Zhou Nicolae Leopold Vasile Chiş Natalia P. Ivleva Reinhard Niessner Andreas Wieser Christoph Haisch 《Analytical and bioanalytical chemistry》2014,406(13):3051-3058
Based on molecular-specific surface-enhanced Raman scattering (SERS) spectroscopy we were able to discriminate between rough and smooth strains of Escherichia coli and Proteus mirabilis bacteria. For this purpose, bacteria have been immobilized through electrostatic forces by inducing a positive charge on the glass slide. This way, SERS spectra on bacterial biomass and also on single bacteria could be recorded in less than 2 h, by using concentrated silver nanoparticles as SERS-active substrate. Single-bacterium SERS spectral fingerprints showed to be sensitive to the presence of the O-antigen at strain level and to the microorganisms growth phase. By using principal component analysis (PCA) on the SERS spectra recorded from E. coli and P. mirabilis, these two uropathogens could be fairly discriminated. 相似文献
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Victor Ch. Kravtsov Vasile Lozovan Nikita Siminel Eduard B. Coropceanu Olga V. Kulikova Natalia V. Costriucova Marina S. Fonari 《Molecules (Basel, Switzerland)》2020,25(23)
Eight mixed-ligand coordination networks, [Cd(2-aba)(NO3)(4-bphz)3/2]n·n(dmf) (1), [Cd(2-aba)2(4-bphz)]n·0.75n(dmf) (2), [Cd(seb)(4-bphz)]n·n(H2O) (3), [Cd(seb)(4-bpmhz)]n·n(H2O) (4), [Cd(hpa)(3-bphz)]n (5), [Zn(1,3-bdc)(3-bpmhz)]n·n(MeOH) (6), [Cd(1,3-bdc)(3-bpmhz)]n ·0.5n(H2O)·0.5n(EtOH) (7), and [Cd(NO3)2(3-bphz)(bpe)]n·n(3-bphz) (8) were obtained by interplay of cadmium nitrate tetrahydrate or zinc nitrate hexahydrate with 2-aminobenzenecarboxylic acid (H(2-aba)), three dicarboxylic acids, sebacic (decanedioic acid, H2seb), homophthalic (2-(carboxymethyl)benzoic acid, H2hpa), isophthalic (1,3-benzenedicarboxylic acid, H2(1,3-bdc)) acids, bis(4-pyridyl)ethane (bpe) and with four azine ligands, 1,2-bis(pyridin-4-ylmethylene)hydrazine (4-bphz), 1,2-bis(1-(pyridin-4-yl)ethylidene) hydrazine (4-bpmhz), 1,2-bis(pyridin-3-ylmethylene)hydrazine (3-bphz), and 1,2-bis(1-(pyridin-3-yl) ethylidene)hydrazine (3-bpmhz). Compounds 1 and 2 are 1D coordination polymers, while compounds 3–8 are 2D coordination polymers. All compounds were characterized by spectroscopic and X-ray diffraction methods of analysis. The solvent uptakes and stabilities to the guest evacuation were studied and compared for 1D and 2D coordination networks. The de-solvated forms revealed a significant increase of emission in comparison with the as-synthesized crystals. 相似文献