16 research outputs found
Platelet Carbonic Anhydrase II, a Forgotten Enzyme, May Be Responsible for Aspirin Resistance
Background. Thromboembolic events constitute a major health problem, despite the steadily expanding arsenal of antiplatelet drugs. Hence, there is still a need to optimize the antiplatelet therapy. Objectives. The aim of our study was to verify a hypothesis that there are no differences in platelet proteome between two groups of healthy people representing different acetylsalicylic acid (aspirin) responses as assessed by the liquid chromatography/mass spectrometry (LC/MS) technique. Patients/Methods. A total of 61 healthy volunteers were recruited for the study. Physical examination and blood collection were followed by platelet-rich plasma aggregation assays and platelet separation for proteomic LC/MS analysis. Arachidonic acid- (AA-) induced aggregation (in the presence of aspirin) allowed to divide study participants into two groups aspirin-resistant (AR) and aspirin-sensitive (AS) ones. Subsequently, platelet proteome was compared in groups using the LC/MS analysis. Results. The LC/MS analysis of platelet proteome between groups revealed that out of all identified proteins, the only discriminatory protein, affecting aspirin responsiveness, is platelet carbonic anhydrase II (CA II). Conclusions. CA II is a platelet function modulator and should be taken into consideration as a cardiovascular event risk factor or therapeutic target
Independent Component Analysis-motivated Approach to Classificatory Decomposition of Cortical Evoked Potentials
BACKGROUND: Independent Component Analysis (ICA) proves to be useful in the analysis of neural activity, as it allows for identification of distinct sources of activity. Applied to measurements registered in a controlled setting and under exposure to an external stimulus, it can facilitate analysis of the impact of the stimulus on those sources. The link between the stimulus and a given source can be verified by a classifier that is able to "predict" the condition a given signal was registered under, solely based on the components. However, the ICA's assumption about statistical independence of sources is often unrealistic and turns out to be insufficient to build an accurate classifier. Therefore, we propose to utilize a novel method, based on hybridization of ICA, multi-objective evolutionary algorithms (MOEA), and rough sets (RS), that attempts to improve the effectiveness of signal decomposition techniques by providing them with "classification-awareness." RESULTS: The preliminary results described here are very promising and further investigation of other MOEAs and/or RS-based classification accuracy measures should be pursued. Even a quick visual analysis of those results can provide an interesting insight into the problem of neural activity analysis. CONCLUSION: We present a methodology of classificatory decomposition of signals. One of the main advantages of our approach is the fact that rather than solely relying on often unrealistic assumptions about statistical independence of sources, components are generated in the light of a underlying classification problem itself
Physical properties of coals in the Upper Silesian Coal Basin in the aspect of coal and methane outbursts
W artykule przedstawiono wyniki badań właściwości fizycznych, w tym mechanicznych i technologicznych węgli GZW w aspekcie ich wyrzutowości. Węgle reprezentowały warstwy libiąskie, łaziskie, orzeskie i rudzkie. Na podstawie wartości wytrzymałości na ściskanie i zwięzłości, zgodnie z dotychczasową wiedzą empiryczną o zjawiskach gazodynamicznych, węgle zostały podzielone na nieskłonne i skłonne do wyrzutów węgla i metanu. Analiza wartości parametrów fizycznych, w tym mechanicznych wykazała wyraźne zróżnicowanie wartości kilku z nich. Uwzględniając fizykę zjawiska wyrzutu węgla i metanu, autorzy zaproponowali nowy kryterialny parametr wyrzutowości węgli, za jaki uznali współczynnik tarcia. Jego wartość kryterialna pomiędzy węglami skłonnymi do wyrzutów a nieskłonnymi została ustalona empirycznie wstępnie na poziomie 0,65.In the article there were presented the results of research of physical properties, including mechanical and technical ones, of coals within the USCB in the aspect of their susceptibility to outbursts. Coals were represented by libiąskie, łaziskie, orzeskie and rudzkie beds. They were divided into two groups - susceptible and non-susceptible to outbursts - on the basis of compression strength value and consistency, in accordance with previous knowledge gained empirically with reference to gas-dynamic occurrences. The analysis of physical parameters values, including mechanical ones, showed explicit variety of values of some of them. Taking into account physics of coal and methane outburst phenomenon the authors propose a new parameter of coals susceptibility to outbursts such as friction coefficient. Its limit value between coals susceptible and non-susceptible to outbursts initially was empirically established on the level of 0.65
Brushless DC motor excited by permanent magnets for battery-electric trucks
W produkowanych obecnie wózkach akumulatorowych stosowane są silniki komutatorowe w wykonaniu szeregowym. Bezszczotkowe silniki prądu stałego zapewniają większą sprawność, trwałość i cichobieżność. Celem prowadzonych prac jest opracowanie, wykonanie i wdrożenie do produkcji bezszczotkowego silnika prądu stałego o mocy 8 kW przeznaczonego do wózków akumulatorowych produkowanych przez Fabrykę Maszyn w Leżajsku. W referacie przedstawiono zarysy projektu silnika wraz z układem sterowania o mocy 8 kW oraz wyniki badań wykonanego modelu silnika.This paper deals with design, assembling and measurements of 8kW brushless DC motor for battery-electric trucks. The paper contains of measurements of flux density in air gap, load and efficiency curves. It contains also measured currents and voltages in windings of motor
High-performance liquid chromatographic determination of colouring matters in historical garments from the Holy Mountain of Athos
Light availability and land‐use history drive biodiversity and functional changes in forest herb layer communities
1. A central challenge of today's ecological research is predicting how ecosystems will develop under future global change. Accurate predictions are complicated by (a) simultaneous effects of different drivers, such as climate change, nitrogen deposition and management changes; and (b) legacy effects from previous land use.
2. We tested whether herb layer biodiversity (i.e. richness, Shannon diversity and evenness) and functional (i.e. herb cover, specific leaf area [SLA] and plant height) responses to environmental change drivers depended on land‐use history. We used resurvey data from 192 plots across nineteen European temperate forest regions, with large spatial variability in environmental change factors. We tested for interactions between land‐use history, distinguishing ancient and recent (i.e. post‐agricultural) forests and four drivers: temperature, nitrogen deposition, and aridity at the regional scale and light dynamics at the plot‐scale.
3. Land‐use history significantly modulated global change effects on the functional signature of the herb layer (i.e. cover, SLA and plant height). Light availability was the main environmental driver of change interacting with land‐use history. We found greater herb cover and plant height decreases and SLA increases with decreasing light availability in ancient than in recent forests. Furthermore, we found greater decreases in herb cover with increased nitrogen deposition in ancient forests, whereas warming had the strongest decreasing effect on the herb cover in recent forests. Interactive effects between land‐use history and global change on biodiversity were not found, but species evenness increased more in ancient than in recent forests.
4. Synthesis. Our results demonstrate that land‐use history should not be overlooked when predicting forest herb layer responses to global change. Moreover, we found that herb layer composition in semi‐natural deciduous forests is mainly controlled by local canopy characteristics, regulating light levels at the forest floor, and much less by environmental changes at the regional scale (here: warming, nitrogen deposition and aridity). The observed disconnect between biodiversity and functional herb layer responses to environmental changes demonstrates the importance of assessing both types of responses to increase our understanding of the possible impact of global change on the herb layer