Standard SANC modules

In this note we summarize the status of the standard SANC modules (in the EW and QCD sectors of the Neutral Current branch — version 1.21 and the Charged Current branch — version 1.20). All versions of the codes are accessible from the SANC project servers at Dubna http://sanc.jinr.ru and CERN http://pcphsanc.cern.ch.     

Design of intelligent chitosan/heparin hollow microcapsules for drug delivery

In this study, a novel strategy has been developed for the assembly of polyelectrolyte multilayer (PEM) on CaCO₃ templates in acidic pH solutions, where consecutive polyelectrolyte layers (heparin/poly(allylamine hydrochloride) or heparin/chitosan) were deposited on PEM hollow microcapsules established previously on CaCO₃ templates. The PEM build‐up, hollow capsule characterization and successful encapsulation of fluorescein 5(6)‐isothiocyanate (FITC)‐Dextran by coprecipitation with CaCO₃ are demonstrated. Improvement by the removal of CaCO₃ core was achieved while the depositions. In the course of the release profile, high retardation for encapsulated FITC‐Dextran was observed. The combined shell capsules system is a significant trait that has potential use in tailoring functional layer‐by‐layer capsules as intelligent drug delivery vehicles where the preliminary in vitro tests showed the responsiveness on the enzymes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44425.     

Bounds on Minimum Distance for Linear Codes over GF(5)

Let [n, k, d; q]-codes be linear codes of length n, dimension k and minimum Hamming distance d over GF(q). Let d ₅(n, k) be the maximum possible minimum Hamming distance of a linear [n, k, d; 5]-code for given values of n and k. In this paper, forty four new linear codes over GF(5) are constructed and a table of d ₅(n, k) k≤ 8, n≤ 100 is presented.     

Optimal semi-oblique tiling

For 2D iteration space tiling, we address the problem of determining the tile parameters that minimize the total execution time on a parallel machine. We consider uniform dependency computations tiled so that (at least) one of the tile boundaries is parallel to the domain boundaries. We determine the optimal tile size as a closed form solution. In addition, we determine the optimal number of processors and also the optimal slope of the oblique tile boundary. Our results are based on the BSP model, which assures the portability of the results. Our predictions are justified on a sequence global alignment problem specialized to similar sequences using Fickett's k-band algorithm, for which our optimal semi-oblique tiling yields an improvement of a factor of 2.5 over orthogonal tiling. Our optimal solution requires a block-cyclic distribution of tiles to processors. The best one can obtain with only block distribution (as many authors require) is three times slower. Furthermore, our best running time is within 10 percent of the "predicted theoretical peak" performance of the machine!.     

Recrystallization of bacterial S-layers on flat polyelectrolyte surfaces and hollow polyelectrolyte capsules

Polyelectrolyte multilayer (PE) deposition and S-layer technology have been combined to make novel robust biomimetic surfaces and membranes. Isolated subunits of the bacterial cell surface layer from Bacillus sphaericus CCM2177 SbpA was self-assembled on PE multilayer supports, with the composition of the multilayer playing a crucial role in determining the structure of the resulting supported protein layers. Flat substrates were studied using atomic force microscopy and neutron reflectometry; protein on suitable PE combinations showed a crystalline structure with lattice constants equal to those found in vivo on bacterial surfaces. The mechanical stability of the S-layer is higher when recrystallized on PEs than directly on silicon supports. The recrystallization process was subsequently used to coat colloidal particles, permitting the determination of zeta potentials before and after coating. Hollow capsules could also be coated in the same way, as proven by various techniques. Our results suggest that electrostatic interactions via divalent cations are important for the assembly process. The results also demonstrate that the versatility of the PE multilayer membranes can be successfully combined with the well-defined surface chemistry and structure of 2D protein crystals.     

Mapping bacterial surface layers affinity to polyelectrolytes through the building of hybrid macromolecular structures

A novel hybrid sandwich-like supramolecular structure (polyelectrolyte multilayer/S-layer/ polyelectrolyte multilayer/S-layer) has been built by combining polyelectrolyte multilayer deposition and self-assembly of isolated SbpA proteins from Bacillus sphaericus CCM2177. Neutron reflectometry measurements were used to confirm the formation of an S-layer on negative poly(styrene sulphonate) (PSS) terminated multilayers, further adsorption of cationic poly(allylamine hydrochloride) polyelectrolyte on the exposed S-layer surface, and final polyelectrolyte multilayer deposition. Surface topography investigations with atomic force microscopy showed that: (i) the two dimensional structure of the S-layer is similar to those found in bacteria, (ii) cationic poly(allylamine hydrochloride) adsorbs on the bacterial protein side that faces the aqueous media, and (iii) anionic poly(styrene sulphonate) does not adsorb on the S-layer surface. Mechanical stability studies on recrystallized S-layers on anionic negative poly(styrene sulphonate) reveal that loads of 20 nN are able to unfold the S-layer protein. A second adsorption of SbpA monomers on top of a structure composed of polyelectrolyte multilayer/S-layer/polyelectrolyte multilayer led to the formation of S-layers patches mechanically stable for loads up to 9 nN. This hybrid polymer-protein supramolecular complex has permitted to elucidate the nature of the affinity of the bacterial cell surface protein to polyelectrolytes.