Average rate of phenological changes in Poland according to climatic changes : evaluation and mapping

The main objective of this study was evaluation and mapping of an average rate of phenological changes for example special plant s indicators as a result of climatic changes in Poland. Multi-year analysis clearly showed a tendency to earlier onset of spring events. The average advance of flowering/leafing was -1.4 days/decade and -2.4 days/1^{\circ}C. Whereas the response of autumn phenophases was ambiguous. Phenological and climate data come from archives of the Institute of Meteorology and Water Management. Analysis covered the period of 1951-1992. The relation between temperature and date of phenophases was described with Pearson's linear regression model. Statistical significance of the model parameters was checked with Student's t-test at the following levels: 0.05, 0.01, and 0.001. The results were visualised on maps. ArcGIS 9.2 Geostatistical Analyst was used to examine the data and create prediction maps. Numerous tests were performed in order to find an appropriate method of spatial interpolation. Finally kriging was chosen as the most precise

Practical computational toolkits for dendrimers and dendrons structure design

Dendrimers and dendrons offer an excellent platform for developing novel drug delivery systems and medicines. The rational design and further development of these repetitively branched systems are restricted by difficulties in scalable synthesis and structural determination, which can be overcome by judicious use of molecular modelling and molecular simulations. A major difficulty to utilise in silico studies to design dendrimers lies in the laborious generation of their structures. Current modelling tools utilise automated assembly of simpler dendrimers or the inefficient manual assembly of monomer precursors to generate more complicated dendrimer structures. Herein we describe two novel graphical user interface (GUI) toolkits written in Python that provide an improved degree of automation for rapid assembly of dendrimers and generation of their 2D and 3D structures. Our first toolkit uses the RDkit library, SMILES nomenclature of monomers and SMARTS reaction nomenclature to generate SMILES and mol files of dendrimers without 3D coordinates. These files are used for simple graphical representations and storing their structures in databases. The second toolkit assembles complex topology dendrimers from monomers to construct 3D dendrimer structures to be used as starting points for simulation using existing and widely available software and force fields. Both tools were validated for ease-of-use to prototype dendrimer structure and the second toolkit was especially relevant for dendrimers of high complexity and size.Peer reviewe

Vegetable sources of semi-finished chemical and pharmaceutical products. Example of triterpene made from chestnut

Biologicznie aktywne i medycznie użyteczne substancje naturalne pochodzenia roślinnego występują na ogół w wieloskładnikowych grupach związków o podobnych właściwościach chemicznych i fizykochemicznych, co znacznie utrudnia ich izolację, a zwłaszcza oczyszczanie. Lecznicze saponiny kasztanowca, tradycyjnie stosowane w medycynie w postaci złożonej mieszaniny (escyna), są przykładem sytuacji w której właściwości farmakologiczne indywidualnych komponentów. Zaprezentowano jedno z możliwych rozwiązań tego problemu na drodze transformacji chemicznych dostępnego surowca, które umożliwiają otrzymanie kluczowego pentacyklicznego triterpenu – protoescygeniny (PES) w stanie wysokiej czystości chemicznej, w procesie realizowanym w pilotowej skali technicznej. Wskazano możliwości zastosowania PES jako dogodnego półproduktu do syntez saponinomimetyków o zróżnicowanych typach struktury.Biologically active and medically useful natural substances of vegetable origin usually occur in multi-component groups of compounds with similar chemical and physical properties, which significantly inhibit their isolation, and in particular their purification. Therapeutic chestnut saponins, traditionally used in medicine in the form of complex mixture (aescin), are the example of situation where pharmacological properties of individual components. One of the solutions to this issue was presented, based on chemical transformation of available raw material, allowing production of key pentacyclical triterpene - protoescigenin (PES) of high chemical purity, in the process implemented on pilot scale. Possibilities of using PES as a convenient semi-finished product fin the synthesis of mimetic saponins with varying structures

RF Phase Reference Distribution for the European XFEL

The RF Phase Reference Distribution system followed by the LLRF control system must assure precise stabilization of the RF field withinthe accelerating cavities of the European XFEL accelerator. The required amplitude and phase accuracy respectively dA/A <3E-5, dphi<0.01 deg @ 1.3GHz in the injector and dA/A<1E-3, dphi <0.1 deg @1.3GHz in the main LINAC section. The RF synchronization systemwill distribute a harmonic phase reference signal from the Master Oscillator system to hundreds of devices distributed in the 3.4 kmlong facility. This contribution describes the proposed architecture of the distribution system which takes advantages of both coaxialand optical distribution links designed in order to provide a good compromise between performance, reliability and cost. Amongst themost important components are interferometers build to suppress phase drifts in coaxial cables. General concept, issues and achievementswill be presented together with results of prototype devices measurements performed to validate our concept