Thio-functionalised glucosinolates: unexpected transformation of desulfoglucoraphenin

Enzymatic desulfation of stable glucoraphenin affords desulfoglucoraphenin, which unexpectedly undergoes further transformations into cyclic nitrone-type derivatives.     

A hybrid genetic algorithm for the two-dimensional single large object placement problem

In the two-dimensional single large object placement problem, we are given a rectangular master surface which has to be cut into a set of smaller rectangular items, with the aim of maximizing the total value of the pieces cut. We consider the special case in which the items cannot be rotated and must be cut with their edges always parallel to the edges of the surface. We present new greedy algorithms and a hybrid genetic approach with elitist theory, immigration rate, heuristics on-line and tailored crossover operators. Extensive computational results for a large number of small and large benchmark test problems are presented. The results show that our approach outperforms existing heuristic algorithms.     

Effect of ultrasonic irradiation on production of fermented milk with Lactobacillus delbrueckii

Milk fermentation with Lactobacillus delbrueckii under ultrasonic irradiation was carried out in a 450 cm³ bioreactor with a polyethylene film bottom. Ultrasonic irradiation increased the hydrolysis of lactose in milk but decreased the cell viability. However, the viable cell count increased again when the ultrasound was stopped, because ultrasound did not destroy the ability for cell propagation. When the sonication power was 17.2 kW m^-2 and the sonication period was 3 h, 4.9 × 10⁸ cfu cm^-3 of the viable cell count and 55% lactose hydrolysis were attained. In contrast, the viable cell count was 2 × 10⁹ cfu cm^-3 and 35.6% lactose was hydrolysed in control fermentation.     

Fabrication of anodic photocurrent generation systems by use of 6-O-dihydrophytylcellulose as a matrix or a scaffold of porphyrins

Langmuir-Blodgett (LB) films containing porphyrin molecules were fabricated by use of 6-O-dihydrophytylcellulose (DHPC) toward anodic photocurrent generation systems. To suppress the porphyrin aggregation, two different approaches were applied: (1) mixing a low-molecular-weight porphyrin having a diterpenoid carbon skeleton (DPor) with DHPC as a matrix (matrix fabrication) and (2) bonding porphyrin molecules to the hydroxyl groups of DHPC covalently, converting into 6-O-dihydrophytyl-2,3-di-O-[p-(10,15,20-triphenyl-5-porphyrinyl)-benzoyl]cellulose as a scaffold (scaffold fabrication). The structure and film properties of the monolayers and the LB films were investigated by the surface pressure (π)–area (A) isotherm measurements, atomic force microscopy, UV–Vis spectroscopy, and absorption dichroism measurements. The porphyrin aggregation in the LB film could be well suppressed only by the scaffold fabrication, leading to the improvement of the photocurrent quantum yields. The efficient photocurrent performance can be demonstrated by the isolation and the parallel orientation of porphyrin moieties due to the cellulose rigid scaffold. This paper was the subject of the Best Poster Award of the 235th edition of the ACS National Meeting, Cellulose and Renewable Materials.     

Time scale and freeze-out volume in the Xe + Cu reaction at 45 MeV/u

Correlations between Intermediate Mass Fragments were measured for the reaction Xe + Cu atE/A= 45 MeV/u. The velocity correlation function for central 3-fold events, depleted at small values of the relative coordinate, as typical for fast decay processes, reflects the mutual Coulomb repulsion between the emitted fragments. From the comparisons between a significant number of experimental observables and the predictions of the Berlin Multifragmentation Model, it appears that the data are compatible with a simultaneous multifragment emission.     

An efficient Pd(II)-based catalyst system for carboxylation of aromatic C-H bond by addition of a phosphenium salt

Addition of a phosphenium dramatically improved the reaction yields in the carboxylation of arenes by formic acid catalyzed by Pd(II). Control experiments revealed that the majority of the phosphenium triflate was converted to a mixed anhydride of phosphonic acid and formic acid (7), which however did not substitute for the phosphenium to improve the reaction yield.     

Sawtooth oscillation in current-carrying plasma in the large helical device

Sawtooth oscillations have been observed in current-carrying helical plasmas by using electron-cyclotron-emission diagnostics in the Large Helical Device. The plasma current, which is driven by neutral beam injection, reduces the beta threshold of the sawtooth oscillation. When the central q value is increased due to the plasma current, the core region crashes, and, when it is decreased, the edge region crashes annularly. Observed rapid mixture of the plasma in the limited region suggests that these sawtooth crashes are reconnection phenomena. Unlike previous experiments, no precursor oscillation has been observed.     

Synthesis and NMR structure of p41icf,a potent inhibitor of human cathepsin L

The total synthesis and structural characterization of the MHCII-associated p41 invariant chain fragment (P41icf) is described. P41icf plays a crucial role in the maturation of MHC class II molecules and antigen processing, acting as a highly selective cathepsin L inhibitor. P41icf synthesis was achieved using a combined solid-phase/solution approach. The entire molecule (65 residues, 7246 Da unprotected) was assembled in solution from fully protected peptides in the size range of 10 residues. After deprotection, oxidative folding in carefully adjusted experimental conditions led to the completely folded and functional P41icf with a disulfide pairing identical to that of native P41icf. CD, NMR, and surface plasmon resonance (SPR) were used for the structural and functional characterization of synthetic P41icf. CD thermal denaturation showed clear cooperative behavior. Tight cathepsin L binding was demonstrated by SPR. (1)H NMR spectroscopy at 800 MHz of unlabeled P41icf was used to solve the three-dimensional structure of the molecule. P41icf behaves as a well-folded protein domain with a topology very close to the crystallographic cathepsin L-bound form.