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91.
The N2 reduction reaction in the system (η-C5H5)2TiCl2-Mg in tetrahydrofuran was examined. The 13C and 1H NMR results as well as the chemical properties of the products formed revealed that the reaction yielded a mixture of compounds in which the titanium atom was bonded both to the μ-(η5: η5-fulvalene) ligand and to the cyclopentadienyl ligands. In this system dinitrogen undergoes reduction to N3?, which then forms M3N bridges (M = Ti, Mg). The nitride nitrogen may readily be oxidized to imide nitride N?1, which may react further, e.g. with carbon monoxide to produce isocyanates, or, with excess oxidizing agent N2. THF in this system undergoes polymerisation. In addition, a ?OC4H9 alkoxy group is formed which makes the substitution of the cyclopentadienyl group bonded to the titanium atoms possible. 相似文献
92.
93.
Mierzwicki K Mielke Z Sałdyka M Coussan S Roubin P 《Physical chemistry chemical physics : PCCP》2008,10(9):1292-1297
The complex formed between water and tetrafluoromethane has been studied by infrared matrix isolation spectroscopy and ab initio calculations. The geometries of the CF4-H2O complexes were optimized in two steps at the MP2/aug-cc-pVTZ level of theory. The structure found at this level was reoptimized on the CP-corrected potential energy surface. The interaction energy was partitioned according to the SAPT scheme and the topological analysis of the electron density was performed. The optimized structure corresponds to the nonhydrogen bonded complex with an oxygen atom of water oriented toward the carbon atom of CF4. The infrared spectra of CF4-H2O /Ne(Ar) matrices demonstrate the presence of a well defined CF4-H2O structure in accord with theoretical prediction. Two complex vibrations were identified in the spectra of neon matrices and four vibrations were observed in the spectra of argon matrices. The available experimental data are in accord with the CP-corrected calculated data. 相似文献
94.
Monika Wujec Agata Siwek Marta Swatko‐Ossor Liliana Mazur Zofia Rzaczynska 《Journal of heterocyclic chemistry》2008,45(6):1893-1896
By the reaction aminomethylation, chloromethylation and acylation of 4‐methyl‐4H‐1,2,4‐triazole‐3‐thiol, 4‐methyl‐1‐substituted‐1H‐1,2,4‐triazole‐5(4H)‐thione 1‐8 were obtained. Molecular structure of the obtained compounds was confirmed by an elemental analysis, IR, 1H NMR and 13C NMR spectra and additionally by X‐ray analysis for 2. Six new compounds 1,2,4‐7 were tested for antibacterial activity against Mycobacterium smegmatis, Mycobacterium phlei and avirulent strain Mycobacterium H37Ra. 相似文献
95.
Konieczny MT Konieczny W Sabisz M Skladanowski A Wakieć R Augustynowicz-Kopeć E Zwolska Z 《Chemical & pharmaceutical bulletin》2007,55(5):817-820
Isomeric oxathiolone fused chalcones were prepared by condensation of appropriate acetylbenzo[1,3]oxathiol-2-ones with benzaldehydes under acidic conditions. The synthesized compounds were screened for cytotoxic activity using HeLa cells, as well as for antibacterial activity against Micrococcus luteus, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, Proteus vulgaris, antifungal activity against Candida albicans, and tuberculostatic activity against Mycobacterium tuberculosis H(37)Rv and Mycobacterium kansasii strains. 相似文献
96.
Tomasz Bujak Martyna Zagrska-Dziok Aleksandra Ziemlewska Zofia Nizio-ukaszewska Tomasz Wasilewski Zofia Hordyjewicz-Baran 《Molecules (Basel, Switzerland)》2021,26(9)
Nowadays, natural dyes are expected by the cosmetic and food industries. In contrast to synthetic dyes, colorants derived from natural sources are more environmentally friendly and safer for human health. In this work, plant extracts from Gomphrena globasa L., Clitoria ternatea L., Carthamus tinctorius L., Punica granatum L. and Papaver rhoeas L. as the natural and functional dyes for the cosmetics industry were assessed. Cytotoxicity on keratinocyte and fibroblast cell lines was determined as well as antioxidant and anti-aging properties by determining their ability to inhibit the activity of collagenase and elastase enzymes. In addition, the composition of the extracts was determined. The obtained extracts were also applied in face cream formulation and color analyses were performed. It has been shown that the obtained extracts were characterized by no cytotoxicity and a high antioxidant potential. The extracts also show strong ability to inhibit the activity of collagenase and moderate ability to inhibit elastase and provide effective and long-lasting hydration after their application on the skin. Application analyses showed that the extracts of P. rhoeas L., C. ternatea L. and C. tinctorius L. can be used as effective cosmetic dyes that allow for attainment of an intense and stable color during the storage of the product. The extracts of P. granatum L. and G. globasa L., despite their beneficial effects as active ingredients, did not work effectively as cosmetic dyes, because cosmetic emulsions with these extracts did not differ significantly in color from emulsions without the extract. 相似文献
97.
Armand Cholewka Agata Stanek Magdalena Wójcik Karolina Sieroń-Stołtny Zofia Drzazga 《Journal of Thermal Analysis and Calorimetry》2017,127(2):1155-1162
Thermal imaging has been used for patients with spinal diseases who were qualified by their physicians for whole-body treatment or local cryotherapy. The experimental groups of patients consisted of 20 males aged 51.6 ± 9.0 (12 treated by whole-body cryotherapy and 8 by local cryotherapy). The distribution of the skin surface temperature was monitored by using a Thermovision Camera E60 before and immediately after body cooling. The chosen spinal region (Th5/Th6–L5/S1) was taken into consideration for all of the research groups. An essential drop in skin temperature and a better differentiation of the body surface temperatures (leading to an increase in the diagnostic value of thermography) was observed after both methods of cold impact. In order to estimate the usefulness of thermovision used after body cooling, the quantitative parameters including temperature contrast—the difference between the maximum and minimum temperatures before and after cold impact and relative contrast ratio (related to the average temperature of the selected area of interest, before and after cooling, respectively)—were compared for both kinds of medical treatment. The statistical analysis proved that significant differences between the parameters obtained before and after body cooling in the case that patients treated by local and whole-body cryotherapy are similar. However, local therapy is cheaper and easy for application while whole-body therapy can give more information about the state of soft tissues for the whole back. 相似文献
98.
Jokiel M Shcharbin D Janiszewska J Urbanczyk-Lipkowska Z Bryszewska M 《Journal of fluorescence》2007,17(1):73-79
The interactions between polycationic poly-lysine dendrimers and hydrophobic fluorescent probes (anionic ANS and neutral Prodan)
were studied. R121 and R131 dendrimers were not able to interact with anionic and neutral hydrophobic groups. R124 was able
to interact with neutral and anionic hydrophobic fluorescent probes, however mainly through hydrophobic forces. Dendrimers
R155 and R169 showed the maximal effects. The strongest interactions observed for R169 can be explained by intramolecular
folding (stacking) of its two L-proline residues. Using double fluorescence titration technique for ANS probe allowed to receive
such constant of binding and the number of binding centers: for R121, 1.8·103 (mol/l)−1 and 1.07; for R124, 12.1·103 (mol/l)−1 and 0.48; for R131, 4.7·103 (mol/l)−1 and 0.48; for R155, 9.2·103 (mol/l)−1 and 1.36; for R169, 39.6·103 (mol/l)−1 and 0.97. Thus, neutral and anionic hydrophobic probes can be used for the fast preliminary screening of binding properties
of newly synthesized polycationic dendrimers. 相似文献
99.
Kurkiewicz S Dzierzewicz Z Wilczok T Dworzanski JP 《Journal of the American Society for Mass Spectrometry》2003,14(1):58-62
A single-step method suitable for cellular fatty acid derivatization to picolinyl esters with the use of a pyrolyzer as a thermochemical micro-reactor was developed for whole bacterial cells. This reduced the preparation time from several hours to less than two minutes. In addition, the minimal bacterial mass required for analysis was reduced from several milligrams to micrograms. The profiling of cellular fatty acids of gram-positive and gram-negative bacteria was achieved using three derivatization methods: preparation of methyl esters, beta-picolinyl esters by Harvey's method and a new method based on pyrolytic derivatization to beta-picolinyl esters. It was shown that there are great similarities between profiles of bacterial fatty acids determined by the pyrolytic derivatization method and traditional preparation methods of picolinyl and methyl esters prior to GC analysis. Results obtained by application of the new technique have immense diagnostic value due to vast similarities between profiles of fatty acids derivatized to either picolinyl and methyl esters. Although the latter are referred to in the literature most often, mass spectra of picolinyl esters contain fragment ions that provide structural information about the chain branching, position of unsaturation, and other substituents. 相似文献
100.
Zofia Denkowska Maciej P. Denkowski 《Journal of Mathematical Analysis and Applications》2012,387(1):48-65
We investigate the Kuratowski convergence of the connected components of the sections of a definable set applying the result obtained to semialgebraic approximation of subanalytic sets. We are led to some considerations concerning the connectedness of the limit set in general. We discuss also the behaviour of the dimension of converging sections and prove some general facts about the Kuratowski convergence in tame geometry. 相似文献