Stabilisierung von M+‐Ionen (M = In,Tl) durch Dibenzyldichlorogallat

Stabilization of M⁺ Ions (M = In, Tl) by Dibenzyldichlorogallate MCl reacts with (PhCH₂)₂GaCl to give M[(PhCH₂)₂GaCl₂] [M = In ( 1 ), Tl ( 2 )]. 1 and 2 were characterized by NMR, IR and MS techniques. In addition, an X‐ray structure determination of 1 was performed. According to this, 1 consists of four‐membered In₂Cl₂ rings connected by weak In…Cl contacts (344 pm) along [010] to a coordination polymer. The In⁺ ion is coordinated by four In–Cl and two In‐aryl interactions.     

Synthese und Kristallstruktur von [(PhCH2)2GaF(tBuNH2)]2 · 2 THF

Synthesis and Crystal Structure of [(PhCH₂)₂GaF(^tBuNH₂)]₂ · 2 THF (PhCH₂)₂GaF reacts with ^tBuNH₂ to the adduct [(PhCH₂)₂GaF(^tBuNH₂)] ( 1 ). 1 was characterized by NMR, IR and MS techniques. 1 can be recrystallized from THF forming crystals of [ 1 ]₂ · 2 THF. According to an X-ray structure analysis [ 1 ]₂ · 2 THF consists of dimers of 1 formed by hydrogen bridges. The THF molecules are coordinated to [ 1 ]₂ by hydrogen bridges, too.     

含油岩心显微荧光成像光谱研究

发展了一种显微荧光光谱成像技术,并将其应用于天然岩心进行显微荧光成像光谱研究。利用这种技术同时采集含油岩心表面的荧光光谱信息和空间信息．并对获得的光谱图像给予光谱学和地质学解释。结果表明,不但能显示岩心形貌和组分的大致趋势,而且能揭示其精细细节．为石油地质研究提供了一种新方法,为今后的石油勘探开发工作提供了一种先进的指导手段。     

Fluorescence resonance energy transfer as a probe of peptide cyclization catalyzed by nonribosomal thioesterase domains

Macrocyclization of synthetic peptides by thioesterase (TE) domains excised from nonribosomal peptide synthetases (NRPS) has been limited to peptides that contain TE-specific recognition elements. To alter substrate specificity of these enzymes by evolution efforts, macrocyclization has to be detected under high-throughput conditions. Here we describe a method to selectively detect cyclic peptides by fluorescence resonance energy transfer (FRET). Using this method, picomolar detection limits were easily realized, providing novel entry for kinetic studies of catalyzed macrocyclization. Application of this method also provides an ideal tool to track TE-mediated peptide cyclization in real time. The general utility of FRET-assisted detection of cyclopeptides was demonstrated for two cyclases, namely tyrocidine (Tyc) TE and calcium-dependent antibiotic (CDA) TE. For the latter cyclase, this approach was combined with site-directed affinity labeling, opening the possibility for high-throughput enzymatic screening.     

Derivative pricing methodology in continuous-time models

We show that the fundamental methodology (and practice) of evaluation of derivative securities in continuous-time models is consistent with discrete-time theory, in which a derivative price is based on the principle that adding this security to the market does not create a violation of the basic economic principle: no riskless profit with zero investment.     

Magnetic Convection in a Nonuniformly Rotating Electroconducting Medium

Journal of Experimental and Theoretical Physics - We study the stability of a convective flow in a nonuniformly rotating plasma layer in an axially uniform magnetic field. The stationary and...