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111.
Wach JY Malisova B Bonazzi S Tosatti S Textor M Zürcher S Gademann K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(34):10579-10584
The synthesis and evaluation of new dopamine-based catechol anchors coupled to poly(ethylene glycol) (PEG) for surface modification of TiO(2) are reported. Dopamine is modified by dimethylamine-methylene (7) or trimethylammonium-methylene (8) groups, and the preparation of mPEG-Glu didopamine polymer 11 is presented. All these PEG polymers allow stable adlayers on TiO(2) to be generated through mild dip-and-rinse procedures, as evaluated both by variable angle spectroscopic ellipsometry and X-ray photoelectron spectroscopy. The resulting surfaces substantially reduced protein adsorption upon exposure to full human serum. 相似文献
112.
Papousková B Bednár P Frysová I Stýskala J Hlavác J Barták P Ulrichová J Jirkovský J Lemr K 《Journal of mass spectrometry : JMS》2007,42(12):1550-1561
Selected precursors and degradation products of chemical warfare agents namely N,N-dialkylaminoethane-2-ols, N,N-dialkylaminoethyl-2-chlorides and some of related N-quaternary salts were studied by means of electrospray ionization-multiple tandem mass spectrometry (ESI-MS(n)). Proposed structures were confirmed with accurate mass measurement. General fragmentation patterns of these compounds are discussed in detail and suggested processes are confirmed using deuterated standards. The typical processes are elimination of alkene, hydrogen chloride, or water, respectively. Besides, elimination of ethene from propyl chain under specific conditions was observed and unambiguously confirmed using exact mass measurement and labelled standard. The potential of mass spectrometry to distinguish the positional isomers occurring among the studied compounds is reviewed in detail using two different MS instruments (i.e. ion trap and hybrid quadrupole-time of flight (Q-TOF) analyzer). A new microcolumn liquid chromatography (microLC)/MS(n) method was designed for the cases where the resolution based solely on differences in fragmentation is not sufficient. Low retention of the derivatives on reversed phase (RP) was overcome by using addition of less typical ion pairing agent (1 mM/l, 3,5-dinitrobenzoic acid) to the mobile phase (mixture water : acetonitrile). 相似文献
113.
Peter Segl’a Jozef Miklovič Dušan Mikloš Ján Titiš Radovan Herchel Ján Moncol Barbora Kaliňáková Daniela Hudecová Viera Mrázová Tadeusz Lis Milan Melník 《Transition Metal Chemistry》2008,33(8):967-974
Synthesis and characterization of 10 new 2-methylthionicotinate (2-MeSnic) Co(II) complexes, namely, [Co(2-MeSnic)2L2(H2O)2] · nH2O (L is N,N-diethylnicotinamide—Et2nia, ethylnicotinate—Etnic, nicotinamide—nia, isonicotinamide—isonia, N-methylnicotinamide—N-Menia, furo[3,2-c]pyridine—fpy, 2,3-dimethylfuro[3,2-c]pyridine—Me2fpy or benzo[4,5]furo[3,2-c]pyridine—Bfp; n is 0, 1 or 2) as well as [Co(2-MeSnic)2L2] (L is ronicol—ron or 2-methylfuro[3,2-c]pyridine—Mefpy), are reported. The characterizations were based on physico-chemical
and spectroscopic methods. The crystal structure of one of the complexes has been determined. In the molecular complex [Co(2-MeSnic)2(Me2fpy)2(H2O)2], the Co(II) central atom, located at a symmetry centre, is octahedrally coordinated by an oxygen atom of the unidentate
2-MeSnic carboxyl group, the nitrogen atom of the pyridine ring of Me2fpy, a water molecule and the corresponding centrosymmetrically located atoms. Also, biological activity of the complexes
against various strains of bacteria and filamentous fungi has been investigated. It is concluded that by complexation of these
nicotinate derivatives their biological activities are elevated.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
114.
Ivana Tatárová Avinash P. Manian Barbora Široká Thomas Bechtold 《Cellulose (London, England)》2010,17(5):913-922
Swelling of regenerated cellulose in nonalkali aqueous solutions containing lithium chloride and urea (LiCl/urea/water) was
examined. The effect of solution concentration on fiber properties was studied using microscopy, weight gain (swelling), and
mechanical strength tests. The regenerated cellulose samples included lyocell fibers, viscose fibers, and fibers spun from
alkali. The change in the mechanical properties of treated fibers was smaller than that of fibers treated with alkali to the
same level of swelling. The degree of swelling in these solutions was related to the propensity for the formation of Li–cellulose
coordination complexes, and these were enhanced by reductions in both urea and water content. 相似文献
115.
Lucie Benesova Milos Pesek Barbora Belsanova Patrik Sekerka Marek Minarik 《Journal of separation science》2010,33(15):2349-2355
The presence of activating mutations within the tyrosine kinase domain of the epidermal growth factor receptor gene has been attributed to a positive response to biological therapy of lung cancer by small‐molecular tyrosine kinase inhibitors, gefitinib and erlotinib. Among the two most significant mutation types are deletions in exon 19 and a single point substitution in exon 21 (termed L858R). The exon 19 deletions can readily be examined by fragment analysis, due to the characteristic length difference between the normal and mutated PCR product. Analysis of the L858R point mutation, however, presents a greater challenge. The current paper is aimed at developing a sensitive, yet simple, low‐cost mutation detection assay directed at the L858R mutation using a method based on CE of heteroduplexes under partial denaturing conditions. We perform optimization of separation conditions on different commercial instruments including ones equipped with 8, 16 and 96 capillaries. We present normalized migration reproducibility in the range from 1 (8 and 16) to 5% (96) RSD. A reliable distinction of the R836R silent polymorphism from a potential presence of the L858R mutation is also demonstrated. In its implementation, the presented assay is just another application running on a conventional CE platform without the need of dedicated instrumentation. 相似文献
116.
Barbora Ferencová 《Discrete Mathematics》2010,310(12):1661-1675
A graph H is defined to be light in a family H of graphs if there exists a finite number φ(H,H) such that each G∈H which contains H as a subgraph, contains also a subgraph K≅H such that the ΔG(K)≤φ(H,H). We study light graphs in families of polyhedral graphs with prescribed minimum vertex degree δ, minimum face degree ρ, minimum edge weight w and dual edge weight w∗. For those families, we show that there exists a variety of small light cycles; on the other hand, we also present particular constructions showing that, for certain families, the spectrum of short cycles contains irregularly scattered cycles that are not light. 相似文献
117.
Some slow potentiometric dyes, e.g., 3,3-dipropylthiacarbocyanine and tetramethylrhodamine methyl ester, exhibit fluorescence spectral changes on redistributing from aqueous medium to cells. This effect has been used for spectroscopic discrimination of the emissions from free and bound dyes in cells. Such a discrimination can, in principle, allow for the assessment of cell membrane potential in individual cells, using the Nernst equation applied to the ratio of free dye fluorescence intensities inside and outside of the cell. 相似文献
118.
Miroslav Janata Luděk Toman Jiří Spěváček Jiří Brus Antonín Sikora Petra Látalová Petr Vlček Jiří Michálek Barbora Dvořánková 《Journal of polymer science. Part A, Polymer chemistry》2007,45(17):4074-4081
This article describes the synthesis and characterization of new amphiphilic polymer conetworks containing hydrophilic poly(2,3‐dihydroxypropyl methacrylate) or poly(ethylene glycol) methacrylate (PEGMA) and hydrophobic polyisobutylene chains. This conetworks were prepared by a two‐step polymer synthesis. In the first step, a cationic copolymer of isobutylene and 3‐isopropenyl‐α,α‐dimethylbenzyl isocyanate (IDI) was prepared. The isocyanate groups of the IB‐IDI random copolymer were subsequently transformed in situ to methacrylate (MA) groups in reaction with 2‐hydroxyethyl methacrylate (HEMA). In the second step, the resulting MA‐multifunctional PIB‐based crosslinker, PIB(MA)n, with an average functionality of approximately four per chain, was copolymerized with 2,3‐dihydroxypropyl methacrylate or poly(ethylene glycol) methacrylate by radical mechanism in tetrahydrofuran giving rise to amphiphilic conetworks containing 11–60 mol % of DHPMA or 10–12 mol % of PEGMA. The synthesized conetworks were characterized with solid‐state 13C‐NMR spectroscopy and differential scanning calorimetry. The amphiphilic nature of the conetworks was proved by swelling in both water and n‐heptane. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4074–4081, 2007 相似文献
119.
ludk Toman Miroslav Janata Jií Spv
ek Barbora Dvonkov Petra Ltalov Petr Vl
ek Antonín Sikora Jií Michlek Michal Pekrek 《Journal of polymer science. Part A, Polymer chemistry》2006,44(9):2891-2900
Amphiphilic polymer networks consisting of hydrophilic poly(2‐hydroxyethyl methacrylate) (PHEMA) and hydrophobic polyisobutylene (PIB) chains were synthesized from a cationic copolymer of isobutylene (IB) and 3‐isopropenyl‐α,α‐dimethylbenzyl isocyanate (IDI) prepared at ?50 °C in dichloromethane in conjunction with SnCl4. The isocyanate groups of this random copolymer, PIB(NCO)n, were subsequently transformed in situ to methacrylate (MA) groups in the dibutyltin dilaurate‐catalyzed reaction with 2‐hydroxyethyl methacrylate (HEMA) at 30 °C. The resulting PIB(MA)n with number–average molecular weight 8200 and average functionality Fn ~ 4 per chain was in situ copolymerized radically with HEMA at 70 °C, giving rise to the amphiphilic networks containing 41 and 67 mol % HEMA. PHEMA–PIB network containing 43 mol % HEMA was also prepared by radical copolymerization of PIB(MA)n precursor with HEMA using sequential synthesis. An amphiphilic nature of the resulting networks was proved by swelling in both water and n‐heptane. PIB(NCO)n and PIB(MA)n were characterized by FTIR spectroscopy, SEC and the latter also by 1H NMR spectroscopy. Solid state 13C NMR spectroscopy was used for characterization of the resulting PHEMA–PIB networks. Whereas single glass‐transition temperature, Tg = ?67.4 °C, was observed for the rubbery crosslinked PIB prepared by reaction of PIB(NCO)n with water, the PHEMA–PIB networks containing 67 and 41 mol % HEMA showed two Tg's: ?70.4 and 102.7 °C, and ?63 and 107.2 °C, respectively. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2891–2900, 2006 相似文献
120.
Spin crossover (SCO) coordination compounds that show bistability between low spin and high spin states are promising light-controllable molecular switches. Selective wavelength irradiation of the coordination centre at low temperatures is known as a light-induced excited spin state trapping (LIESST effect) and it leads to the modulation of physical properties of SCO materials on the macroscopic as well as on the molecular level. Another way to trigger the spin state conversion by light is based on the isomerization of photoactive ligand moieties. The ligand field strength is changed due to light-induced photoisomerization and, therefore, corresponding cis–trans or ring-closing/ring-opening isomeric couples might exhibit different spin states at isothermal conditions. Such an approach is called as ligand driven light-induced spin change (LD LISC effect). From the application point of view, it presents a promising alternative to the LIESST effect because it can operate at room temperature. This article is focused on the most interesting iron and cobalt SCO compounds with photoisomerizable ligands and provides the overview of achieving results based on the LD LISC effect. 相似文献