Changes in diffusion tensor imaging (DTI) eigenvalues of skeletal muscle due to hybrid exercise training

Several studies have proposed the cell membrane as the main water diffusion restricting factor in the skeletal muscle cell. We sought to establish whether a particular form of exercise training (which is likely to affect only intracellular components) could affect water diffusion. The purpose of this study is to characterise prospectively the changes in diffusion tensor imaging (DTI) eigenvalues of thigh muscle resulting from hybrid training (HYBT) in patients with non-alcoholic fatty liver disease (NAFLD). Twenty-one NAFLD patients underwent HYBT for 30 minutes per day, twice a week for 6 months. Patients were scanned using DTI of the thigh pre- and post-HYBT. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), the three eigenvalues lambda 1 (λ1), λ2, λ3, and the maximal cross sectional area (CSA) were measured in bilateral thigh muscles: knee flexors (biceps femoris (BF), semitendinosus (ST), semimembranous (SM)) and knee extensors (medial vastus (MV), intermediate vastus (IV), lateral vastus (LV), and rectus femoris (RF)), and compared pre- and post-HYBT by paired t-test. Muscle strength of extensors (P < 0.01), but not flexors, increased significantly post-HYBT. For FA, ADC and eigenvalues, the overall picture was of increase. Some (P < 0.05 in λ2 and P < 0.01 in λ1) eigenvalues of flexors and all (λ1-λ3) eigenvalues of extensors increased significantly (P < 0.01) post-HYBT. HYBT increased all 3 eigenvalues. We suggest this might be caused by enlargement of muscle intracellular space.     

Identification of unknown surfactants using electrospray mass spectrometry and NMR spectroscopy preceded by liquid ionization mass spectrometry

Commercially available but completely unknown surfactants used in the tin-lead plating industry were successfully identified by using electrospray mass spectrometry and NMR spectroscopy techniques, preceded by liquid ionization mass spectrometry used to obtain the preliminary information. The mass spectral data suggested that ethoxylated nonionic surfactants having a homologous distribution of molecular weights like 520, 564, 608, 652, 696, etc. were present. The NMR data suggested the presence of two aromatic rings and a quaternary carbon for the hydrophobe moiety instead of the well-known alkyl chains or alkylphenols. The unknown surfactants were finally concluded to be novel nonionic 4-(alpha,alpha-dimethylbenzyl)-phenol ethoxylates.     

One‐Pot/Sequential Native Chemical Ligation Using N‐Sulfanylethylanilide Peptide

N‐Sulfanylethylanilide (SEAlide) peptides were developed with the aim of achieving facile synthesis of peptide thioesters by 9‐fluorenylmethyloxycarbonyl (Fmoc)‐based solid‐phase peptide synthesis (Fmoc SPPS). Initially, SEAlide peptides were found to be converted to the corresponding peptide thioesters under acidic conditions. However, the SEAlide moiety was proved to function as a thioester in the presence of phosphate salts and to participate in native chemical ligation (NCL) with N‐terminal cysteinyl peptides, and this has served as a powerful protein synthesis methodology. The reactivity of a SEAlide peptide (anilide vs. thioester) can be easily tuned with or without the use of phosphate salts. This interesting property of SEAlide peptides allows sequential three‐fragment or unprecedented four‐fragment ligation for efficient one‐pot peptide/protein synthesis. Furthermore, dual‐kinetically controlled ligation, which enables three peptide fragments simultaneously present in the reaction to be ligated in the correct order, was first achieved using a SEAlide peptide. Beyond our initial expectations, SEAlide peptides have served in protein chemistry fields as very useful crypto‐peptide thioesters. DOI 10.1002/tcr.201200007     

Strong and selective binding of amiloride to an abasic site in RNA duplexes: thermodynamic characterization and microRNA detection

Firmly tied: The binding affinity of amiloride for an abasic (AP) site-containing RNA duplex is two orders of magnitude superior to the affinity of the corresponding AP site-containing DNA duplex. The observed high binding affinity for the RNA duplex arises from a favorable enthalpy gain. The binding-induced fluorescence response of amiloride is applicable to microRNA detection.     

Can a meso-type dinuclear complex be chiral?: dinuclear β-diketonato Ru(III) complexes

Dinuclear Ru(III) complexes, [Ru(III)(acac)(2)(dabe)Ru(III)(acac)(2)] (acacH = acetylacetone; dabeH(2) = 1, 2-diacetyl-1,2-dibenzoylethane) and [Ru(III)(acac)(2)(tbet)Ru(III)(acac)(2)] (tbetH(2) = 1,1,2,2-tetrabenzoylethane) were synthesized by reacting [Ru(acac)(2)(CH(3)CN)(2)]PF(6) with dabeH(2) and tbetH(2) respectively, in toluene. The X-ray structural analysis of a meso-type dinuclear Ru(III) complex, ΔΛ-[Ru(III)(acac)(2)(dabe)Ru(III)(acac)(2)], showed that the bridging part became chiral due to the orthogonal twisting of two non-symmetrical β-diketonato moieties. To confirm this conclusion, the complex was resolved chromatographically to provide a pair of optical antipodes. Such chirality in the bridging part was not generated for [Ru(III)(acac)(2)(tbet)Ru(III)(acac)(2)], because the β-diketonato moieties in tbet(2-) are symmetrical.