Synthesis of Fully O-Benzylated N-Linked Core Pentasaccharide Glycosyl Azide

The fully O-benzylated pentasaccharide glycosyl azide representing the common core structure of N-glycans was synthesized. The β-mannosidic linkage was created by C-2 epimerization of the initially introduced β-d- gluco-unit via DMSO/Ac₂O oxidation followed by stereoselective reduction with tetrabutylammonium borohydride.     

A practical algorithm for decomposing polygonal domains into convex polygons by diagonals

We present algorithms for decomposing a polygon (with holes) into convex polygons by diagonals. The methods are computationally quick, and although the partitions that they produce may not have minimal cardinality they usually have a low number of convex pieces. Thus, the methods are suitable for being used when achieving a modest load on the CPU time is more important than finding optimal decompositions as, for instance, in location problems. Part of the results in this paper are from Fernández (1999), and were presented in Fernández et al. (1998). This work has been supported by the Ministry of Science and Technology of Spain under the research projects BEC2002-01026, SEJ2005-06273/ECON (J. Fernández, B. Tóth and B. Pelegrín) and TIC2003-05982-C05-03 (L. Cánovas), in part financed by the European Regional Development Fund (ERDF).     

Characterization of HPGe gamma spectrometers by geant4 Monte Carlo simulations

Two coaxial and a low-energy HPGe detector were characterized with Monte Carlo simulations, using the geant4 toolkit. The geometry of the detectors, including the dimensions of the crystal and the internal structural parts, were initially taken from the factory specifications and from X-ray radiographies, and were later fine-tuned. The detector response functions, with special emphasis on the absolute full-energy peak efficiencies and peak-to-total ratios, were calculated and compared to experimental data taken at different measurement geometries. Between 150 keV and 11 MeV an agreement within 1–2 standard deviation has been achieved, whereas systematic deviations were experienced at lower energies.     

para‐Nitroblebbistatin,the Non‐Cytotoxic and Photostable Myosin II Inhibitor

Blebbistatin, the best characterized myosin II‐inhibitor, is commonly used to study the biological roles of various myosin II isoforms. Despite its popularity, the use of blebbistatin is greatly hindered by its blue‐light sensitivity, resulting in phototoxicity and photoconversion of the molecule. Additionally, blebbistatin has serious cytotoxic side effects even in the absence of irradiation, which may easily lead to the misinterpretation of experimental results since the cytotoxicity‐derived phenotype could be attributed to the inhibition of the myosin II function. Here we report the synthesis as well as the in vitro and in vivo characterization of a photostable, C15 nitro derivative of blebbistatin with unaffected myosin II inhibitory properties. Importantly, para‐nitroblebbistatin is neither phototoxic nor cytotoxic, as shown by cellular and animal tests; therefore it can serve as an unrestricted and complete replacement of blebbistatin both in vitro and in vivo.     

Synthesis and MALDI-TOF MS Analysis of Protected Oligosaccharide Components of N-Glycoproteins

Essential components of N-glycoproteins were synthesized in octyl glycoside form starting from 3-O-allyl-D-glucose derivative. The β-mannosidic linkage was formed by the oxidation reduction method. MALDI-TOF mass spectrometry and its post-source decay (PSD) mode were used for identification and structural elucidation of protected synthetic oligosaccharides related to N-glycoproteins. Most fragments, identified in the PSD spectra, were products of the cleavage of glycosidic bonds.     

Obtaining an outer approximation of the efficient set of nonlinear biobjective problems

A new method for obtaining an outer approximation of the efficient set of nonlinear biobjective optimization problems is presented. It is based on the well known ‘constraint method’, and obtains a superset of the efficient set by computing the regions of δ-optimality of a finite number of single objective constraint problems. An actual implementation, which makes use of interval tools, shows the applicability of the method and the computational studies on a set of competitive location problems demonstrate its efficiency. An extended version of this paper, with more comments, details, examples, and references, can be found in Fernández and Tóth [5]. This paper has been supported by the Ministry of Education and Science of Spain under the research project SEJ2005-06273/ECON, in part financed by the European Regional Development Fund (ERDF). Boglárka Tóth—On leave from the Research Group on Artificial Intelligence of the Hungarian Academy of Sciences and the University of Szeged, H-6720 Szeged, Aradi vértanúk tere 1., Hungary.     

Multi-dimensional pruning from the Baumann point in an Interval Global Optimization Algorithm

A new pruning method for interval branch and bound algorithms is presented. In reliable global optimization methods there are several approaches to make the algorithms faster. In minimization problems, interval B&B methods use a good upper bound of the function at the global minimum and good lower bounds of the function at the subproblems to discard most of them, but they need efficient pruning methods to discard regions of the subproblems that do not contain global minimizer points. The new pruning method presented here is based on the application of derivative information from the Baumann point. Numerical results were obtained by incorporating this new technique into a basic Interval B&B Algorithm in order to evaluate the achieved improvements. This work has been supported by the Ministry of Education and Science of Spain through grants TIC 2002-00228, TIN2005-00447, and research project SEJ2005-06273 and by the Integral Action between Spain and Hungary by grant HH2004-0014. Boglárka Tóth: On leave from the Research Group on Artificial Intelligence of the Hungarian Academy of Sciences and the University of Szeged, H-6720 Szeged, Aradi vértanúk tere 1., Hungary.