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71.
Padmanaban M Müller P Lieder C Gedrich K Grünker R Bon V Senkovska I Baumgärtner S Opelt S Paasch S Brunner E Glorius F Klemm E Kaskel S 《Chemical communications (Cambridge, England)》2011,47(44):12089-12091
A modular approach for the synthesis of highly ordered porous and chiral auxiliary (Evans auxiliary) decorated metal-organic frameworks is developed. Our synthesis strategy, which uses known porous structures as model materials for incorporation of chirality via linker modification, can provide access to a wide range of porous materials suitable for enantioselective separation and catalysis. Chiral analogues of UMCM-1 have been synthesized and investigated for the enantioseparation of chiral compounds in the liquid phase and first promising results are reported. 相似文献
72.
Das Arulsamy A Kregar Z Eleršič K Modic M Subramani US 《Physical chemistry chemical physics : PCCP》2011,13(33):15175-15181
Hydrogen produced from the photocatalytic splitting of water is one of the reliable alternatives to replace the polluting fossil and the radioactive nuclear fuels. Here, we provide unequivocal evidence for the existence of blue- and red-shifting O-H covalent bonds within a single water molecule adsorbed on the MgO surface as a result of asymmetric displacement polarizabilities. The adsorbed H-O-H on MgO gives rise to one weaker H-O bond, while the other O-H covalent bond from the same adsorbed water molecule compensates this effect with a stronger bond. The weaker bond (nearest to the surface), the interlayer tunneling electrons and the silver substrate are shown to be the causes for the smallest dissociative activation energy on the MgO monolayer. The origin that is responsible to initiate the splitting mechanism is proven to be due to the changes in the polarizability of an adsorbed water molecule, which are further supported by the temperature-dependent static dielectric constant measurements for water below the first-order electronic-phase transition temperature. 相似文献
73.
Milojković-Opsenica Dusanka M. Lazarević Kristina Ivačković Vojkan Tešić Zivoslav Lj. 《平面色谱法杂志一现代薄层色谱法》2003,16(4):276-279
JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of nine frequently used water-soluble food dyes has been studied by TLC on RP-18 silica gel.... 相似文献
74.
The three forms of enterostatin (Ala-Pro-Gly-Pro-Arg, Val-Pro-Gly-Pro-Arg, and Val-Pro-Asp-Pro-Arg), pentapeptides known to inhibit fat-intake, were resolved on a C18 reversed-phase column using a ternary mobile phase consisting of methanol, acetonitrile, and water. Coupled with MS/MS detection, the method has been applied to identify enterostatin sequences in human cerebrospinal fluid and rat brain tissue. Ala-Pro-Gly-Pro-Arg (APGPR) was found to be the predominant enterostatin sequence in both cases. The levels of APGPR were 98.3±16.3 ng/ml in human cerebrospinal fluid and 30.1±12.6 ng/g wet tissue in rat brain, respectively. 相似文献
75.
76.
Moriyama Y Moriyama EH Blackmore K Akens MK Lilge L 《Photochemistry and photobiology》2005,81(6):1351-1355
This study was designed to demonstrate that bioluminescence imaging (BLI) can be used as a new tool to evaluate the effects of low-level laser therapy (LLLT) during in vivo inflammatory process. Here, the efficacy of LLLT in modulating inducible nitric oxide synthase (iNOS) expression using different therapeutic wavelengths was determined using transgenic animals with the luciferase gene under control of the iNOS gene expression. Thirty transgenic mice, FVB/N-Tg(iNOS-luc)Xen, were allocated randomly to one of four experimental groups treated with different wavelengths (lambda = 635, 785, 808 and 905 nm) or a control group (nontreated). Inflammation was induced by intra-articular injection of zymosan A in both knee joints. Laser treatment (25 mW cm(-2), 200 s, 5 J cm(-2)) was applied to the knees 15 min after inflammation induction. Measurements of iNOS expression were performed at various times (0, 3, 5, 7, 9 and 24 h) by measuring the bioluminescence signal using a highly sensitive charge-coupled device (CCD) camera. The results showed a significant increase in BLI signal after irradiation with 635 nm laser when compared to the nonirradiated animals and the other LLLT-treated groups, indicating wavelength dependence of LLLT effects on iNOS expression during the inflammatory process, and thus demonstrating an action spectrum of iNOS gene expression following LLLT in vivo that can be detected by BLI. Histological analysis was also performed and demonstrated the presence of fewer inflammatory cells in the synovial joints of mice irradiated with 635 nm compared with nonirradiated knee joints. 相似文献
77.
Starcević K Karminski-Zamola G Piantanida I Zinić M Suman L Kralj M 《Journal of the American Chemical Society》2005,127(4):1074-1075
Spectroscopic titrations and thermal denaturation experiments show that "acyclic" analogue 1 does not bind to ds-DNA, but under same conditions "cyclic" 2 strongly interacts with ds-DNA and ds-RNA by intercalation into the double helix. Besides, 2 is significantly more effective in inhibition of the tumor cell growth in vitro than 1. We have shown that it is possible to efficiently and irreversibly convert "DNA inactive" compound 1 into "DNA active" compound 2 by light irradiation of the aqueous solutions of the former. This strategy offers a new and attractive approach to photoinduced anticancer therapy. 相似文献
78.
Earle MJ Hakala U Hardacre C Karkkainen J McAuley BJ Rooney DW Seddon KR Thompson JM Wahala K 《Chemical communications (Cambridge, England)》2005,(7):903-905
Chloroindate(III) ionic liquids are versatile reaction media for Friedel-Crafts acylation reactions; the system is catalytic and totally recyclable, using an aqueous workup, with no leaching of the indium into the product phase. 相似文献
79.
Human serum albumin consists of a single polypeptide of 585 amino acid residues with 1 Trp residue. In the present work, we
measured fluorescence lifetimes of the protein in both native and denatured states. The results indicate that Trp emission
occurs with three lifetimes in both states. Lifetimes values and contribution to the global emission decay differ between
the two states. Data are interpreted as the results of an emission occurring from three substructures of the tryptophan formed
in the excited state. Two of these substructures are already present for the tryptophan free in solution. The third lifetime
is the result of the interaction between the tryptophan residue and surrounding microenvironment. The populations of these
substructures characterized by the pre-exponential parameters of the fluorescence lifetimes are dependent on the fluorophore
microenvironment and on the global protein structure. 相似文献
80.
Cole ML Deacon GB Forsyth CM Konstas K Junk PC 《Dalton transactions (Cambridge, England : 2003)》2006,(27):3360-3367
Treatment of calcium or strontium with 2.0 equivalents of N,N-bis(o-methylphenyl)formamidine (o-TolFormH), N,N-bis(2,6-dimethylphenyl)formamidine (XylFormH) or N,N-bis(o-phenylphenyl)formamidine (o-PhPhFormH) in the presence of 1.0 equivalent of Hg(C6F5)2 in tetrahydrofuran (thf) affords the bis(formamidinate) complexes [Ca(o-TolForm)2(thf)2] (1), [Ca(XylForm)2(thf)2] (2), [Ca(o-PhPhForm)2(thf)2].thf (3), [Sr(o-TolForm)2(thf)3] (4), [Sr(XylForm)2(thf)3].3thf (5) and [Sr(o-PhPhForm)2(thf)3].2thf (6). Analogous reactions with barium were generally unsatisfactory but [Ba(o-PhPhForm)2(thf)3].2thf (7) was successfully prepared. Compounds 1-7 have been characterised by various spectroscopic methods (1H, 13C{1H} NMR and IR), elemental analyses and, for 1, 2 and 4-6, X-ray crystallography. The calcium complexes are monomeric and six-coordinate with either transoid octahedral or trigonal prismatic geometry, whilst the larger radius of strontium accommodates an additional thf solvent donor to give seven-coordinate structures with two types of coordination polyhedra. 相似文献