Automobily na vodíkový pohon ponúkajú mnoho výhod v porovnaní s automobilom s tradičným spal'ovacím motorom. Ekologicky čistá a tichá prevádzka spojená s vysokou účinnosťou vodíkového palivového článku (VPČ) z nich robí atraktívnych kandidátov na automobily budúcnosti. V tomto článku stručne rozoberám históriu a vývoj VPČ, jeho dizajn ako aj problémy, ktoré je nutné odstranit aby mohla byť táto technológia uvedená v masovom rozsahu do praxe., Fuel cell (FC) cars offer many advantages when compared to cars with combustion engines. Ecologically clean, noise-free and their high fuel efficiency makes fuel cell powered cars attractive candidates for future automobiles. In this paper I briefly discuss the history, development and design of the FC as well as the problems still plaguing this technology and preventing its deployment on the mass scale., Vladimír Komanický., and Obsahuje seznam literatury
Let R be a prime ring of characteristic different from 2, Qr its right Martindale quotient ring and C its extended centroid. Suppose that F, G are generalized skew derivations of R with the same associated automorphism α, and p(x1, ..., xn) is a non-central polynomial over C such that \left[ {F(x),\alpha (y)} \right] = G(\left[ {x,y} \right]). for all x,y\in \left \{ p\left ( r_{1},...,r_{n} \right ):r_{1},...,r_{n}\in R\right \}. The there exist \lambda \in C such that F(x) = G(x) = λα(x) for all X\in R., Vincenzo De Filippis., and Obsahuje seznam literatury
Autonomic nervous system (ANS) disorders are common in multiple sclerosis (MS). Previous studies showed differences in insulin resistance (IR) and lipoprotein levels in MS subjects compared to controls. Lipolysis caused by increased sympathetic activity could be one of the possible linking mechanisms leading to dyslipidemia in MS. Our study aimed to evaluate ANS activity in the context of glucose and lipid metabolism in people with MS. We prospectively measured short-term heart rate variability (HRV), fasting lipoprotein concentrations, and calculated IR indices based on plasma glucose and insulin levels during oral glucose tolerance test (oGTT) in 32 patients with MS and 29 healthy controls matched for age, sex and body mass index in our study. There was no significant difference in HRV parameters and lipoprotein levels between MS and controls. A significant positive correlation was found between low/high-frequency power ratio (LF/HF) and triglycerides (r=0.413, p=0.021) in MS subjects but not in controls. A significantly lower whole-body insulin sensitivity index (ISIMat) was found in patients with MS compared to the control group (7.3±3.7 vs. 9.8±5.6, p=0.041). No significant correlations were found between LF/HF and IR parameters. In MS subjects, the positive correlation of LF/HF with triglycerides could reflect the effects of sympathetic activity on lipolysis. Positive correlations of sympathetic activity with increased lipoprotein levels could rather reflect processes associated with immune system activation/inflammation, than processes involved in glucose homeostasis maintenance.
Dysfunkce autonomního nervového systému patří k častým klinickým projevům roztroušené sklerózy (RS). Incidence autonomní dysfunkce (AD) u pacientů s RS se v různých studiích pohybuje mezi 16 a 80 % a jednoznačně se zvyšuje s délkou trvání RS a progredující disabilitou. Může se však projevit v kterékoli fázi demyelinizačního onemocnění a dokonce může být jeho prvním klinickým projevem. AD významně ovlivňuje kvalitu života pacientů s RS a přispívá k celkové disabilitě. Přesto postižení autonomního nervového systému patří mezi stále relativně poddiagnostikované symptomy tohoto onemocnění. Nejčastějším a nejzávažnějším typem AD u pacientů s RS je narušení funkce kardiovaskulárního a/nebo urogenitálního systému. Méně častá je dysfunkce gastrointestinální, sudomotorická či narušení pupilomotoriky. Autonomní (především kardiovaskulární) dysfunkce u pacientů s RS také úzce souvisí s rozvojem únavy. Cílem tohoto sdělení je poskytnout přehled jednotlivých typů AD u pacientů s RS a možností jejich diagnostiky., Autonomic nervous system dysfunction (AD) represents a frequent clinical presentation of multiple sclerosis (MS). According to published studies, the incidence of AD in MS patients ranges between 16 and 80% and gradually increases with the length of the demyelinating disease and with the progression of disability. However, AD can occur in any phase of MS and can even represent its first symptom in some patients. Autonomic dysfunction has a significant negative impact on the quality of life in MS patients and contributes to overall disability. Even so, autonomic nervous system dysfunction is frequently underdiagnosed in patients with multiple sclerosis. Cardiovascular and urogenital dysfunction are the most frequent types of AD in MS patients with the highest impact on their clinical status and the quality of life. Less frequently, gastrointestinal, sudomotor or pupilomotor dysfunction can be found. Autonomic (in particular cardiovascular) dysfunction in multiple sclerosis is closely related to fatigue, another frequent clinical symptom in MS patients. The aim of this paper is to sum up the spectrum of symptoms of autonomic dysfunction in multiple sclerosis and its diagnostic tools. Key words: multiple sclerosis – autonomic nervous system diseases – orthostatic intolerance –urinary incontinence – urinary retention –sexual dysfunction – gastrointestinal dysfunction – sweating The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers., and I. Šrotová, E. Vlčková, J. Bednařík
A fuzzy model based on an enhanced supervised fuzzy clustering algorithm is presented in this paper. The supervised fuzzy clustering algorithm [6] allows each rule to represent more than one output with different probabilities for each output. This algorithm implements k-means to initialize the fuzzy model. However, the main drawbacks of this approach are that the number of clusters is unknown and the initial positions of clusters are randomly generated. In this work, the initialization is done by the global k-means algorithm [1], which can autonomously determine the actual number of clusters needed and give a deterministic clustering result. In addition, the fast global k-means algorithm [1] is presented to improve the computation time. The model is tested on medical diagnosis benchmark data and Westland vibration data. The results obtained show that the model that uses the global k-means clustering algorithm [1] has higher accuracy when compared to a model that uses the k-means clustering algorithm. Besides that, the fast global k-means algorithm [1] also improved the computation time without degrading much the model performance.
We present data supporting the hypothesis that the lysosomalautophagy pathway is involved in the degradation of intracellular triacylglycerols in the liver. In primary hepatocytes cultivated in the absence of exogenous fatty acids (FFA), both inhibition of autophagy flux (asparagine) or lysosomal activity (chloroquine) decreased secretion of VLDL (very low density lipoproteins) and formation of FFA oxidative products while the stimulation of autophagy by rapamycine increased some of these parameters. Effect of rapamycine was completely abolished by inactivation of lysosomes. Similarly, when autophagic activity was influenced by cultivating the hepatocytes in “starving” (amino-acid poor medium) or “fed” (serum-supplemented medium) conditions, VLDL secretion and FFA oxidation mirrored the changes in autophagy being higher in starvation and lower in fed state. Autophagy inhibition as well as lysosomal inactivation depressed FFA and DAG (diacylglycerol) formation in liver slices in vitro. In vivo, intensity of lysosomal lipid degradation depends on the formation of autophagolysosomes, i.e. structures bringing the substrate for degradation and lysosomal enzymes into contact. We demonstrated that lysosomal lipase (LAL) activity in liver autophagolysosomal fraction was up-regulated in fasting and down-regulated in fed state together with the increased translocation of LAL and LAMP2 proteins from lysosomal pool to this fraction. Changes in autophagy intensity (LC3-II/LC3-I ratio) followed a similar pattern., V. Škop ... [et al.]., and Obsahuje seznam literatury