The article deals with the problem of determination of basic parameters of unknown lenses, namely their radii of curvature, thicknesses and refractive indices of materials (e.g. optical glasses) from which these lenses are made. Four methods are proposed to obtain these parameters and mathematical relationships are derived that allow to determine the refractive index and Abbe number of lens material based on the measured radius values, the thickness and the position of the focal point or the focal length. and V článku je řešena problematika určení základních parametrů neznámých čoček, a to jejich poloměrů křivosti, tlouštěk a indexů lomu materiálů (např. optických skel), z kterých jsou tyto čočky zhotoveny. Jsou navrženy čtyři metody získání těchto parametrů a jsou odvozeny matematické vztahy, které umožňují určit index lomu a Abbeovo číslo materiálu čoček, a to na základě naměřených hodnot poloměrů křivosti, tloušťky a polohy obrazového ohniska nebo velikosti ohniskové vzdálenosti.
V práci je řešen jeden z možných způsobů určení materiálových konstant tenké desky, a to pro případ kruhové desky na okraji upnuté. Byly odvozeny vztahy, které umožňují bezdotykovým způsobem určit Poissonovo číslo a modul pružnosti v tahu materiálu desky. V případě, že je materiál desky průhledný (např. kapalinové čočky), jsou uvedeny vztahy pro výpočet indexu lomu a Abbeova čísla tohoto materiálu.
A detailed theoretical analysis of the diffraction theory of imaging of a point object by the optical system is performed. Explicit relationships are established to determine the position of the point micro-particle in the object space of the optical system. and V práci je podrobně teoreticky analyzována difrakční teorie zobrazení bodového předmětu optickou soustavou. Jsou odvozeny explicitní vztahy, které umožňují určit polohu bodové mikročástice v předmětovém prostoru optické soustavy.
This paper deals with an alternative method to determine the thickness of a thin film on a substrate. A linear relation between the thin-film thickness and the wavelength of the reflectance spectrum tangent to the envelope function for specific interference order is revealed in a wide wavelength range. This relation enables the calculation of the thickness provided that the wavelength-dependent optical parameters of the thin film and the substrate are known. The methods allow to calculate the thickness from the reflectance spectrum in a narrow range close to one extreme only as demonstrated both theoretically and experimentally for Sio2 thin-films on Si substrates. The results are discussed for two wavelength ranges and compared with those obtained by the algebraic fitting method. and Práce prezentuje metodu určení tloušťky tenké vrstvy z měření spektrální odrazivosti s využitím nové varianty obálkové metody. Byl nalezen lineární vztah mezi vlnovou délkou tečny spektrální odrazivosti k obálkové funkci a odpovídající tloušťkou tenké vrstvy pro daný interferenční řád v širokém spektrálním oboru. Tento lineární vztah umožňuje výpočet tloušťky vrstvy na základě známých spektrálních optických parametrů vrstvy a podložky. Metoda umožňuje výpočet tloušťky ze znalosti pouze malé části spektra v okolí jednoho extrému, jak je demonstrováno teoreticky a experimentálně na systému SiO2 - Si. Výsledky jsou porovnány s hodnotami, získanými algebraickou fitovací metodou.
The paper reviews recent climate change impact studies for the Slovak National Climate Program (SNKP). Basic adaptation strategies are also discussed. Priorities for future research within the SNKP are suggested. and Článok prináša prehľad o metodických postupoch, používaných v súčasnosti na určovanie možného vplyvu zmeny klímy na odtokové procesy. Nadväzuje pritom na prehľad uvedený v prácach S z o l g a y, et al. (1997), S z o l g a y a H l a v č o v á (2000), H l a v č o v á, et al. (2000) a sústreďuje sa najmä na pokrok v uvedenej problematike za posledné 4 roky, dokumentovaný na základe publikácií v niektorých vedúcich karentovaných časopisoch a výsledkov správy IPCC. Identifikuje smery výskumu v oblasti analýzy časových radov pre posudzovanie možnej zmeny podmienok tvorby odtoku, ako aj v oblasti využívania závislostí medzi odtokom a jeho podmieňujúcimi činiteľmi na určovanie možnej zmeny odtoku v dôsledku klimatickej zmeny.
Studies have shown that uridine concentration in plasma may be an indicator of uric acid production in patients with gout. It has been also postulated that uridine takes part in blood pressure regulation. Since physical exercise is an effective tool in treatment and prevention of cardio-vascular diseases that are often accompanied by hyperuricemia and hypertension, it seemed advisable to attempt to evaluate the relationship between oxypurine concentrations (Hyp, Xan and UA) and that of Urd and BP after physical exercise in healthy subjects. Sixty healthy men (17.2±1.71 years, BMI 23.2±2.31 kg m-2, VO2max 54.7±6.48 ml kg-1 min-1) took part in the study. The subjects performed a single maximal physical exercise on a bicycle ergometer. Blood for analyses was sampled three times: immediately before exercise, immediately after exercise, and in the 30th min of rest. Concentrations of uridine and hypoxanthine, xanthine and uric acid were determined in whole blood using high-performance liquid chromatography. We have shown in this study that the maximal exercise-induced increase of uridine concentration correlates with the post-exercise increase of uric acid concentration and systolic blood pressure. The results of our study show a relationship between uridine concentration in blood and uric acid concentration and blood pressure. We have been the first to demonstrate that a maximal exercise-induced increase in uridine concentration is correlated with the post-exercise and recovery-continued increase of uric acid concentration in healthy subjects. Thus, it appears that uridine may be an indicator of post-exercise hyperuricemia and blood pressure., W. Dudzinska, A. Lubkowska, B. Dolegowska, M. Suska, M. Janiak., and Obsahuje bibliografii
The presence of large amounts of proteins in mammal urine is usually associated with a pathological condition and indicates serious renal lesions. However, there are few species with obligate proteinuria indicating that they must derive some benefit from this condition. Urinary proteins have been most extensively studied in the house mouse and the rat, and findings to date indicate that their function in intraspecific communication is complex and not yet fully understood. Other proteins of the same protein family as MUPs have been also found in urine of some other rodent species, and still less is known about these. In this study we demonstrate the existence of urinary lipocalins in Mastomys coucha for the first time. Our results support the hypothesis that urinary proteins may play an important role in chemical communication, and level of polymorphism of these proteins in different rodents may help us to understand their specific function.
The hyperinsulinemic euglycemic clamp (HEC) combined with indirect calorimetry (IC) is used for estimation of insulin-stimulated substrate utilization. Calculations are based on urinary urea nitrogen excretion (UE), which is influenced by correct urine collection. The aims of our study were to improve the timing of urine collection during the clamp and to test the effect of insulin on UE in patients with type 1 diabetes (DM1; n=11) and healthy subjects (C; n=11). Urine samples were collected (a) over 24 h divided into 3-h periods and (b) before and during two-step clamp (1 and 10 mIU.kg-1.min-1; period 1 and period 2) combined with IC. The UE during the clamp was corrected for changes in urea pool size (UEc). There were no significant differences in 24-h UE between C and DM1 and no circadian variation in UE in either group. During the clamp, serum urea decreased significantly in both groups (p<0.01). Therefore, UEc was significantly lower as compared to UE not adjusted for changes in urea pool size both in C (p<0.001) and DM1 (p<0.001). While UE did not change during the clamp, UEc decreased significantly in both groups (p<0.01). UEc during the clamp was significantly higher in DM1 compared to C both in period 1 (p<0.05) and period 2 (p<0.01). The UE over 24 h and UEc during the clamp were statistically different in both C and DM1. We conclude that urine collection performed during the clamp with UE adjusted for changes in urea pool size is the most suitable technique for measuring substrate utilization during the clamp both in DM1 and C. Urine collections during the clamp cannot be replaced either by 24-h sampling (periods I-VII) or by a single 24-h urine collection. Attenuated insulin-induced decrease in UEc in DM1 implicates the impaired insulin effect on proteolysis. and Obsahuje bibliografii a bibliografické odkazy
In this study, a loop-mediated isothermal amplification (LAMP) assay was established to detect Toxoplasma gondii DNA in mice infected with T. gondii PRU strain. This LAMP assay was based on the sequence of highly repetitive B1 gene. The detection limit of T. gondii LAMP assay was 1 pg of T. gondii DNA, which was evaluated using 10-fold serially diluted DNA of cultured parasites. The LAMP assay was also highly specific for T. gondii and able to detect T. gondii DNA in urine of mice treated with dexamethasone at 90 day post infection (p.i.), although this assay could not detect the DNA in mice urine 2-6 days p.i. These results demonstrated that LAMP is effective for evaluation of therapy effectiveness for T. gondii infection. The established LAMP assay may represent a useful and practical tool for the routine diagnosis and therapeutic evaluation of human toxoplasmosis.