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1.
The synthesis of oligoethylene glycols of defined lengths possessing different end functionalities is described. The utility of these molecules towards the development of a generic membrane anchor is demonstrated. 相似文献
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Sluszny C Yeung ES Nikolau BJ 《Journal of the American Society for Mass Spectrometry》2005,16(1):107-115
Laser desorption/ionization time-of-flight (LDI-TOF) mass spectrometry was applied for the direct analysis of cuticular waxes on intact plant tissues. Cuticular wax compounds were ionized by laser desorption in the presence of colloidal silver. Silver-adduct ions were detected on samples from Arabidopsis thaliana and from maize. Good spot-to-spot reproducibility indicated homogeneous coverage of the sample by the fine colloidal material. The results were consistent with GC-MS analyses of cuticular extracts, thus confirming the feasibility of direct analysis based on this protocol. Molecular masses of the adduct ions correspond well with the known composition of cuticular waxes. Moreover, LDI-TOF gave good estimates of the relative local abundances of a given compound. However, bias was found in cases where compounds with different ionization efficiencies were analyzed. 相似文献
3.
Calculations of magnetic susceptibilities and topological resonance energies of annelated [14] - and [18] annulenes are reported. For several compounds the magnetic susceptibilities are also measured. In these cases a good agreement between calculated and experimental values of magnetic susceptibilities is obtained. All compounds studied are found to be diamagnetic. According to the magnetic exaltation criterion all compounds studied are predicted to be aromatic. This result is supported in the case of annelated annulenes by the TRE criterion. However, the parent structures, [14] annulene and [18] annulene, are found by the TRE to be non-aromatic. Finally, it is found that the aromatic stability does not parallel inert reactivity, i.e., some highly aromatic annulenoids are predicted by the low HOMO—LUMO separation to be rather reactive and some low aromatic structures are predicted by the high HOMO—LUMO separation to exhibit a considerable reactive inertness. 相似文献
4.
Christakopoulos P Katapodis P Hatzinikolaou DG Kekos D Macris BJ 《Applied biochemistry and biotechnology》2000,87(2):127-133
An α-l-arabinofuranosidase from Fusarium oxysporum F3 was purified to homogeneity by a two-step ion exchange intercalated by a gel filtration chromatography. The enzyme had
a molecular mass of 66 kDa and was optimally active at pH 6.0 and 60°C. It hydrolyzed aryl α-l-arabinofuranosides and cleaved arabinosyl side chains from arabinoxylan and arabinan. There was a marked synergistic effect
between the α-l-arabinofuranosidase and an endo-(1 →4)-β-d-xylanase produced by F. oxysporum in the extensive hydrolysis of arabinoxylan. 相似文献
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Basil I. Swanson Lucia M. Babcock David Schiferl David C. Moody Robert L. Mills Robert R. Ryan 《Chemical physics letters》1982,91(5):393-395
We report Raman measurements made on SO2 in a diamond cell up to 75 kbar showing two new phases, solid II and solid III, which differ from known, zero-pressure solid I. Spectra indicate that SO2 molecules aggregate in solid III to possibly form a cyclical trimer; solid III is shown to be photochemically active to blue radiation. 相似文献
8.
Inês R. Ramos Fiona M. Lyng Ihtesham Ur Rehman Basil Sharrack M. Nicola Woodroofe 《应用光谱学评论》2017,52(10):868-882
Spectroscopy techniques are valuable tools in biomedical research and have been used extensively in the study of disease. However, neurological conditions such as multiple sclerosis (MS) have received little attention and the available spectroscopy studies are limited, both in overall numbers of patients studied and the disease samples considered. MS is a complex immune-mediated disease, with variable clinical courses and limited therapeutic options. This review aims to summarize current literature in the area, demonstrating how spectroscopy techniques can provide valuable information to inform and advance research into the most common neurological condition affecting young adults. 相似文献
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