排序方式: 共有74条查询结果,搜索用时 500 毫秒
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Menzel H Horstmann S Behrens P Bärnreuther P Krueger I Jahns M 《Chemical communications (Cambridge, England)》2003,(24):2994-2995
Polyamines mimicking substances which occur naturally in biosilicas have been synthesized and show an accelerating effect on silica condensation, which depends on the chemical nature, the architecture (linear or branched), and the degree of polymerization. 相似文献
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The Sodium Reduction of Azulene to the Contact-Ion Triple [Disodium-(1,1′,6,6′-Tetrahydro-6,6′-bi(azulene)-1,1′-diide)–bis(diglyme)]∞ Colorless air-sensitive single crystals can be grown from a diglyme solution after the reduction of azulene by a Na-metal mirror. Structure determination at 150 K reveals a dimer dianion, in which the seven-membered rings are connected in 6,6′-positions and doubly diglyme-solvated Na+ counter cations η5-coordinate to the five-membered rings. Based on preceding cyclovoltammetric measurements in aprotic azulene solutions as well as on extensive MNDO enthalpy of formation calculations, a proposal is forwarded how possibly the contact ion triple is formed along a microscopic pathway. 相似文献
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Zimmermann C Anson CE Eckermann AL Wunder M Fischer G Keilhauer I Herrling E Pilawa B Hampe O Weigend F Dehnen S 《Inorganic chemistry》2004,43(15):4595-4603
By reacting 1-aminoethylammonium (H2NCH2CH2NH3+ = enH+) salts of [Sn2E6]4- anions (E = S, Se), [enH]4[Sn2S6] (1) and [enH]4[Sn2Se6] x en (2), with FeCl2/LiCp, three novel (partly) oxidized, Cp* ligated iron chalcogenide clusters were synthesized. Two of them, [(CpFe)3(mu3-S)2] (3) and [(Cp*Fe)3(mu3-Se)2] (4), contain formally 47 valence electrons. [(Cp*Fe)3(SnCl3)(mu3-Se)4] x DME (5) represents the first known mixed metal Fe/Sn/Se heterocubane type cluster. Compounds 3-5 were structurally characterized by single-crystal X-ray diffraction, and the odd valence electron number of the [Fe3E2] clusters (E = S, Se) was confirmed by density functional (DFT) investigations, mass spectrometry, cyclic voltammetry and a susceptibility measurement of 3. 相似文献
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Hashimoto MC Prates RA Kato IT Núñez SC Courrol LC Ribeiro MS 《Photochemistry and photobiology》2012,88(3):590-595
Pseudomonas aeruginosa is considered one of the most important pathogens that represent life‐threatening risk in nosocomial environments, mainly in patients with severe burns. Antimicrobial photodynamic therapy (aPDT) has been effective to kill bacteria. The purpose of this study was to develop a burn wound and bloodstream infection model and verify aPDT effects on it. In vitro, we tested two wavelengths (blue and red LEDs) on a clinical isolate of P. aeruginosa strain with resistance to multiple antibiotics using HB:La+3 as photosensitizer. Verapamil® associated to aPDT was also studied. In vivo, P. aeruginosa‐infected burned mice were submitted to aPDT. Bacterial counting was performed on local infection and bloodstream. Survival time of animals was also monitored. In this study, aPDT was effective to reduce P. aeruginosa in vitro. In addition, Verapamil® assay showed that HB:La+3 is not recognized by ATP‐binding cassete (ABC) efflux pump mechanism. In the in vivo study, aPDT was able to reduce bacterial load in burn wounds, delay bacteremia and keep the bacterial levels in blood 2–3 logs lower compared with an untreated group. Mice survival was increased on 24 h. Thus, this result suggests that aPDT may also be a novel prophylactic treatment in the care of burned patients. 相似文献
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Antonius R.B. Ola Abdessamad Debbab Amal H. Aly Attila Mandi Ilka Zerfass Alexandra Hamacher Matthias U. Kassack Heike Brötz-Oesterhelt Tibor Kurtan Peter Proksch 《Tetrahedron letters》2014
Neosartorin (1) was isolated from the endophytic fungus Aspergillus fumigatiaffinis. The absolute configuration of 1, including both axial and central chirality elements, was established as (aR,5S,10R,5′S,6′S,10′R) for the first time on the basis of its electronic circular dichroism (ECD) spectra aided with TDDFT–ECD calculations. Neosartorin (1) exhibited substantial antibacterial activity against a broad spectrum of Gram-positive bacterial species including staphylococci, streptococci, enterococci, and Bacillus subtilis with minimal inhibitory concentrations in the range of 4–32 μg/mL. When the toxicity of 1 against eukaryotic cells was measured using a panel of different cancer cell lines such as HELA and BALB/3T3, the average IC50 values exceeded 32 μg/mL. 相似文献
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Simon Q Lud Michael G Nikolaides Ilka Haase Markus Fischer Andreas R Bausch 《Chemphyschem》2006,7(2):379-384
For many biotechnological applications the label-free detection of biomolecular interactions is becoming of outstanding importance. In this Article we report the direct electrical detection of small peptides and proteins by their intrinsic charges using a biofunctionalized thin-film resistor. The label-free selective and quantitative detection of small peptides and proteins is achieved using hydrophobized silicon-on-insulator (SOI) substrates functionalized with lipid membranes that incorporate metal-chelating lipids. The response of the nanometer-thin conducting silicon film to electrolyte screening effects is taken into account to determine quantitatively the charges of peptides. It is even possible to detect peptides with a single charge and to distinguish single charge variations of the analytes even in physiological electrolyte solutions. As the device is based on standard semiconductor technologies, parallelization and miniaturization of the SOI-based biosensor is achievable by standard CMOS technologies and thus a promising basis for high-throughput screening or biotechnological applications. 相似文献
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We introduce high resolution clear native electrophoresis (CNE) as a powerful technique to resolve enzymatically active mitochondrial complexes from cultured human cell lines and skeletal muscle biopsy samples. Quantitative enzymatic assays can be performed using small amounts of cultured cells with low mitochondria content, for example, around 10 mg of sedimented osteosarcoma cells (wet weight) which is equivalent to around 10 million cells. High resolution CNE offers general advantages for in-gel catalytic activity assays compared to blue native electrophoresis. It seems especially suited for assaying mitochondrial ATP synthase and respiratory chain complexes I and II in cell models of human mitochondrial disorders and for detailed analyses of patient cells and tissues with defects in oxidative phosphorylation. 相似文献
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