Chiral α,ω-diesters react under high-pressure conditions (10 kbar) with α,ω-diamines to give chiral cyclic tetraamides of C2-symmetry. The complexation properties of tetraamides towards alkali metal cations (Li+, Na+, K+, Rb+ and Cs+) were estimated on the basis of ESI-MS spectra. 相似文献
In this paper, several methods of hydrophobization of cotton fabrics using the thio-ene click reaction were compared. Durable, superhydrophobic textiles were obtained in an easy way. Various variants of functionalized silsesquioxanes were used for the hydrophobization of fabrics. The synthesis of bifunctional silsesquioxanes (RSiMe2O)4(ViSiMe2O)4Si8O12 and (RSiMe2O)4(R’SiMe2O)4Si8O12 were performed via hydrothiolation of silsesquioxane derivative (ViSiMe2O)8Si8O12. Alkoxysilyl, alkyl and fluoroalkyl moieties were introduced as functional groups. Samples were prepared using four methods, differing in the modification method and the number of stages. During the research, fabrics were modified via (a) the dip-coating process, (b) carrying out thiol-ene click reactions directly on the surface of the fabric and (c) using both of these methods. The hydrophobicity of the fabric was evaluated by measuring the Water contact angle (WCA). The obtained samples were also examined using infrared analysis (FT-IR), Scanning electron microscope (SEM), and Elemental analysis (SEM–EDS). All analyses were performed before and after the washing process in order to verify the stability of the performed modifications.
Osteoprotegerin (OPG), a member of the tumor necrosis factor receptor superfamily, is known to inhibit osteoclastogenesis by acting as a soluble decoy receptor for the receptor activator of NF-kappaB ligand (RANKL). We report the presence of OPG on the membrane of osteoclasts and the possibility of the direct action of OPG on them. Highly pure osteoclast precursors were isolated from mouse long bones and induced to differentiate into mature osteoclasts by M-CSF and soluble RANKL (sRANKL). The presence of OPG on the membrane of these cells was confirmed by western blotting and immunostaining. Furthermore, sRANKL was found to be bound to the OPG on the osteoclast precursors. These results suggest that OPG might have a new role during the differentiation of osteoclasts beyond its role as a soluble decoy receptor. The mechanism of the existence of OPG on osteoclast precursors remains to be found. 相似文献
Abstract— Irradiation of thin films consisting of 4,5',8-trimethylpsoralen (TMP), adenosine and small amounts of alcohols led to TMP-alcohol photoadducts in addition to TMP-adenosine photoadducts. Four TMP-ethanol and two TMP-methanol adducts have been separated and characterized. Covalent bonds were formed between the 4-carbon of TMP and the α-carbon to the hydroxy group in the alcohols. The TMP-alcohol photoadducts were formed only in the TMP film containing small amounts of alcohol and adenosine. Furthermore, no photoadduct of TMP and ribose was detected upon photolysis of a TMP-ribose film, suggesting that the adenine moiety plays a specific role in the reaction. The interaction of adenosine with psoralens in a dry film may be related to the DNA sequence selectivity observed for the photoreaction of psoralens with DNA. 相似文献
Microsolvation of the [Ni(acac)(tmen)]+ complex by a series of aliphatic n-alcohols (Solv) has been studied in ClCH2CH2Cl solutions by spectrophotometry. Based on the changes in the electronic spectrum of the afore-mentioned complex, observed under the influence of any alcohol, the equilibrium constants for the formation of the [Ni(acac)(tmen)Solv]+ and [Ni(acac)(tmen)Solv2]+ species have been computed according to the algorithm presented in this work. It was found that, in all the systems studied, the stability of five-coordinated [Ni(acac)(tmen)Solv]+ is higher than that of octahedral [Ni(acac)(tmen)Solv2]+. The resulting values are discussed in terms of the Lewis basicity of alcohols. 相似文献
A simple isotherm equation is derived for the adsorption of an organic component onto activated carbon in presence of water vapour. The theoretical results are compared with experimental data for toluene-water vapour-activated carbon, which were published byRipperger andGermerdonk [10].
Vorhersage der Adsorption einer organischen Komponente und Wasserdampf an Aktivkohle
Zusammenfassung Es wird eine einfache Adsorptionsisotherme abgeleitet, welche die gleichzeitige Adsorption eines organischen Stoffes und Wasser an Aktivkohle beschreibt. Die theoretischen Ergebnisse werden mit experimentellen Resultaten vonRipperger undGermerdonk [10] für Toluol-Wasser-Aktivkohle verglichen.
Symbols
ai
adsorbate concentration in adsorbent, kg/kg of carbon
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a0i
monolayer capacity, kg/kg of carbon
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bi
kinetic parameter of theLangmuir equation
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Ej
adsorption energy in thej-th layer
-
ii-th component (1 — water vapour, 2 — organic compound)
-
jj-th layer
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m
number of layers
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n
number of adsorbed components
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p
partial pressure, Pa
-
p*
saturation partial pressure, Pa
-
pC
water vapour partial pressure at begining of capillary condensation, Pa
-
surface coverage 相似文献
The ruthenium(II) porphyrin fluorophore complexes [Ru(TPP)(CO)(Ds-R)] (TPP = tetraphenylporphinato dianion; Ds = dansyl; R = imidazole (im), 1, or thiomorpholine (tm), 2) were synthesized and investigated for their ability to detect nitric oxide (NO) based on fluorescence. The X-ray crystal structures of 1 and 2 were determined. The Ds-im or Ds-tm ligand coordinates to an axial site of the ruthenium(II) center through a nitrogen or sulfur atom, respectively. Both exhibit quenched fluorescence when excited at 368 or 345 nm. Displacement of the metal-coordinated fluorophore by NO restores fluorescence within minutes. These observations demonstrate fluorescence-based NO detection using ruthenium porphyrin fluorophore conjugates. 相似文献