Synthesis of Novel Pyrido[1,2-c]pyrimidine Derivatives with 6-Fluoro-3-(4-piperidynyl)-1,2-benzisoxazole Moiety as Potential SSRI and 5-HT1A Receptor Ligands

Two series of novel 4-aryl-2H-pyrido[1,2-c]pyrimidine (6a–i) and 4-aryl-5,6,7,8-tetrahydropyrido[1,2-c]pyrimidine (7a–i) derivatives were synthesized. The chemical structures of the new compounds were confirmed by ¹H and ¹³C NMR spectroscopy and ESI-HRMS spectrometry. The affinities of all compounds for the 5-HT_1A receptor and serotonin transporter protein (SERT) were determined by in vitro radioligand binding assays. The test compounds demonstrated very high binding affinities for the 5-HT_1A receptor of all derivatives in the series (6a–i and 7a–i) and generally low binding affinities for the SERT protein, with the exception of compounds 6a and 7g. Extended affinity tests for the receptors D₂, 5-HT_2A, 5-HT₆ and 5-HT₇ were conducted with regard to selected compounds (6a, 7g, 6d and 7i). All four compounds demonstrated very high affinities for the D₂ and 5-HT_2A receptors. Compounds 6a and 7g also had high affinities for 5-HT₇, while 6d and 7i held moderate affinities for this receptor. Compounds 6a and 7g were also tested in vivo to identify their functional activity profiles with regard to the 5-HT_1A receptor, with 6a demonstrating the activity profile of a presynaptic agonist. Metabolic stability tests were also conducted for 6a and 6d.     

Revisiting dictionary‐based compression

An attractive way to increase text compression is to replace words with references to a text dictionary given in advance. Although there exist a few works in this area, they do not fully exploit the compression possibilities or consider alternative preprocessing variants for various compressors in the latter phase. In this paper, we discuss several aspects of dictionary‐based compression, including compact dictionary representation, and present a PPM/BWCA‐oriented scheme, word replacing transformation, achieving compression ratios higher by 2–6% than the state‐of‐the‐art StarNT (2003) text preprocessor, working at a greater speed. We also present an alternative scheme designed for LZ77 compressors, with the advantage over StarNT of reaching up to 14% in combination with gzip. Copyright © 2005 John Wiley & Sons, Ltd.     

The investigation of the lower limb geometry using 3D sonography and magnetic resonance

The main aim of this work was to test the developed system of a free hand sonographic probe in the clinical conditions. The measuring system consists of navigation system tracking the position of a linear ultrasound probe and the self-developed software to control the tools and analyse the recorded data. It enables both measurement of geometrical parameters according to the self-designed template and the identification of the three dimensional shape of bone. Moreover the software provides virtual planning of surgery and supports the surgeon to execute the planned scenario in the reality.     

Fast-curing polyurethane adhesives derived from environmentally friendly hyperbranched polyglycerols - The effect of macromonomer structure

Transformation of glycerol to hyperbranched polyglycerols (HBPGs) and their further application as macromonomers for fast-curing polyurethane adhesives were described. An approach allowing for using of hyperbranched polyglycerols derived from renewable glycerol in adhesive technology was investigated. Four hyperbranched polyglycerols of different structures and functionalities were synthesized and crosslinked with polymeric methylenediphenyldiisocyanate (pMDI) and hexamethylenediisocyanate (HDI). Macromolecule functionality and functional group distribution were shown to be a critical factor in terms of the adhesive performance. The studied approach allowed to conclude that environmentally friendly polyglycerols - derived from renewable glycerol - when properly designed could successfully replace petroleum-based ones.     

Assessment of glass fiber-reinforced polyester pipe powder in soil improvement

This study investigates the use of glass fiber-reinforced polyester (GRP) pipe powder (PP) for improving the bearing capacity of sandy soils. After a series of direct share tests, the optimum PP addition for improving the bearing capacity of soils was found to be 12%. Then, using the optimum PP addition, the bearing capacity of the soil was estimated through a series of loading tests on a shallow foundation model placed in a test box. The bearing capacity of sandy soil was improved by up to 30.7%. The ratio of the depth of the PP-reinforced soil to the diameter of the foundation model (H/D) of 1.25 could sufficiently strengthen sandy soil when the optimum PP ratio was used. Microstructural analyses showed that the increase in the bearing capacity can be attributed to the chopped fibers in the PP and their multiaxial distribution in the soil. Besides improving the engineering properties of soils, using PP as an additive in soils would reduce the accumulation of the industrial waste, thus providing a twofold benefit.     

Over rail-to-rail fully differential voltage-to-current converters for nm scale CMOS technology

The converters presented in this paper are based on long channel complementary MOS transistors, instead of the commonly used differential amplifiers or differential transistor pairs which are difficult to implement in low voltage, nm scale CMOS technology. Nonlinearities of drain currents can be cancelled in the fully differential structure. As a result, the low power, nanometre standard digital CMOS technology converters are obtained. Layout examples are designed in 65 nm TSMC technology. Post-layout simulations show that the range of input voltage over rail-to-rail is achieved with very good linearity and reduced harmonic distortion.     

Scalable pattern mining with Bayesian networks as background knowledge

We study a discovery framework in which background knowledge on variables and their relations within a discourse area is available in the form of a graphical model. Starting from an initial, hand-crafted or possibly empty graphical model, the network evolves in an interactive process of discovery. We focus on the central step of this process: given a graphical model and a database, we address the problem of finding the most interesting attribute sets. We formalize the concept of interestingness of attribute sets as the divergence between their behavior as observed in the data, and the behavior that can be explained given the current model. We derive an exact algorithm that finds all attribute sets whose interestingness exceeds a given threshold. We then consider the case of a very large network that renders exact inference unfeasible, and a very large database or data stream. We devise an algorithm that efficiently finds the most interesting attribute sets with prescribed approximation bound and confidence probability, even for very large networks and infinite streams. We study the scalability of the methods in controlled experiments; a case-study sheds light on the practical usefulness of the approach.     

Multiphase Biomineralization: Enigmatic Invasive Siliceous Diatoms Produce Crystalline Calcite

Diatoms are considered unicellular eukaryotic organisms exclusively depositing biogenic silica. Heretofore there has been no report of calcification by these algae. Here it is shown that calcium carbonate within the stalks of Didymosphenia geminata, a nuisance species that has prolifically colonized streams and rivers globally, is biogenic in origin and occurs as a network of calcite nanofibers. The nanofibrous framework in the mineralized polysaccharide matrix imparts mechanical support to the stalks, providing stability in variable flow conditions. The results demonstrate that D. geminata possesses cellular and periplasmic carbonic‐anhydrases that contribute to carbon fixation and biomineralization, respectively. The activity of external carbonic‐anhydrase was more than 50% of the total activity, which points to its role in anchoring this bioeroding diatom on hard surfaces. The first evidence of multiphase biomineralization by diatoms that deposit both biogenic silica and crystalline biogenic calcite which are imparting distinct functional advantage to the organism is provided.