A maximum matching of a graph G is a matching of G with the largest number of edges. The matching number of a graph G, denoted by {\alpha }'(G), is the number of edges in a maximum matching of G. In 1966, Gallai conjectured that all the longest paths of a connected graph have a common vertex. Although this conjecture has been disproved, finding some nice classes of graphs that support this conjecture is still very meaningful and interesting. In this short note, we prove that Gallai’s conjecture is true for every connected graph G with {\alpha }'(G)\leq 3., Fuyuan Chen., and Obsahuje seznam literatury
A method using body surface potential maps for assessment of myocardium lesions with changed repolarization is presented and suitable mapping system is introduced. Differences between normal and altered QRST integral maps together with torso volume conductor model were used to determine the equivalent dipole representing the lesion. Performance of the method was studied on simulated data. Changed repolarization was modeled by shortening of myocyte action potentials in regions typical for stenosis of the main coronary arteries. The equivalent dipole estimated the positions of small lesions with a mean error of 9±4 mm (17±14 mm for larger transmural lesions). The subepicardial or subendocardial character of the lesions was reflected in the dipole orientation. Tests of the method on patients after myocardial infarction that underwent coronary intervention on a single coronary vessel showed that in 7 of 8 successfully treated patients the dipole position matched well with the treated vessel. A small dipole moment in another patient indicated unsuccessful treatment. The method was implemented in a new 128-channel mapping system. Its active electrodes, battery powered measuring unit and optical computer interface help to minimize noise in ECG and guarantee patient´s safety. The results suggest that the method and mapping system offer useful tools for noninvasive identification of local repolarization changes in the myocardium., M. Tyšler, P. Kneppo, M. Turzová, J. Švehlíková, S. Karas, E. Hebláková, K. Hána, S. Filipová., and Obsahuje bibliografii
b1_We previously demonstrated in rats that noninvasive delayed limb ischemic preconditioning (LIPC) induced by three cycles of 5-min occlusion and 5-min reperfusion of the left hind limb per day for three days confers the sa me cardioprotective effect as local ischemic preconditioning of the heart, but the mechanism has not been studied in depth. The aim of this project was to test the hypothesis that delayed LIPC enhances myocardial antioxidative ability during ischemia-reperfusion by a mitochondrial KATP channel (mito KATP)-dependent mechanism. Rats were randomized to five gr oups: ischemia-reperfusion (IR)- control group, myocardial ischemic preconditioning (MIPC) group, LIPC group, IR-5HD group and LIPC-5HD group. The MIPC group underwent local ischemic precondi tioning induced by three cycles of 5-min occlusion and 5-min reperfusion of the left anterior descending coronary arteries. The LIPC and LIPC-5HD groups underwent LIPC induced by three cycles of 5-min occlusion and 5-min reperfusion of the left hind limb using a modified blood pressure aerocyst per day for three days. All rats were subjected to myocardial ischemia-reperfu sion injury. The IR-5HD and LIPC-5HD groups received the mito KATP channel blocker 5-hydroxydecanoate Na (5-HD) before and during the myocardial ischemia-reperfusion injury. Compar ed with the IR-control group, both the LIPC and MIPC groups showed an amelioration of ventricular arrhythmia, reduced my ocardial infarct size, increased activities of total superoxide dismutase, manganese-superoxide dismutase (Mn-SOD) and glutathione peroxidase, increased expression of Mn-SOD mRNA and decreased xanthine oxidase activity and malondialdehyde concentration. These beneficial effects of LIPC were prevented by 5-HD. In conclusion , delayed LIPC offers similar cardioprotecti on as local IPC., b2_These results support the hypothesis that the activation of mito K ATP channels enhances myocardial antioxidat ive ability during ischemia- reperfusion, thereby contributing, at least in part, to the anti- arrhythmic and anti-infarct effects of delayed LIPC., Y.-N. Wu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Portal-systemic shunting is an important circulatory abnormality in patients with liver cirrhosis. Glyceryl trinitrate (GTN) that is normally subject to first pass elimination, may exhibit higher bioavailability in these patients. This study compares the pharmacodynamic effects of GTN after peroral and sublingual administration for noninvasive assessment of shunting. Six control subjects and 15 patients with cirrhosis were studied after oral and sublingual application of 0.5 mg of GTN. Liver cirrhosis was complicated by portal hypertension in 7 of the patients and 4 patients had surgically implanted portocaval anastomosis. Digital plethysmography, which is highly sensitive and is essentially noninvasive in nature, was used to assess and compare the pharmacodynamic effects of GTN. The following values of the ratio of areas under the pharmacodynamic effects/time curve were obtained: 0.08±0.06 in healthy subjects, 0.52±0.21 in patients with uncomplicated cirrhosis, 0.99±0.34 in patients with portal hypertension and 1.24±0.43 in patients with portal-systemic shunts. We conclude that increased bioavailability of GTN reflects portal-systemic shunting and might be used providing that the pharmacodynamic data reflect both pharmacokinetic variability and the pharmacokinetic-pharmacodynamic interrelations., O. Slanař, J. Aubrecht, F. Perlík., and Obsahuje bibliografii
The pathophysiology of microcirculation is intensively investigated to understand disease development at the microscopic level. Orthogonal polarization spectral (OPS) imaging and its successor sidestream dark-field (SDF) imaging are relatively new noninvasive optical techniques allowing direct visualization of microcirculation in both clinical and experimental studies. The goal of this experimental study was to describe basic microcirculatory parameters of skeletal muscle and ileal serous surface microcirculation in the rat using SDF imaging and to standardize the technical aspects of the protocol. Interindividual variability in functional capillary density (FCD) and small vessels (<25 μm in diameter) proportion was determined in anesthetized rats on the surface of quadriceps femoris (m. rectus femoris and m. vastus medialis) and serous surface of ileum. Special custom made flexible arm was used to fix the SDF probe minimizing the pressure movement artifacts. Clear high contrast images were analyzed off-line. The mean FCD obtained from the surface of skeletal muscle and ileal serous surface was 219 (213-225 cm/cm2) and 290 (282-298 cm/cm2) respectively. There was no statistically significant difference between rats in mean values of FCD obtained from the muscle (P = 0.273) in contrast to ileal serous surface, where such difference was statistically significant (P = 0.036). No statistically significant differences in small vessels percentage was detected on either the muscle surface (P = 0.739) or on ileal serous surface (P = 0.659). Our study has shown that interindividual variability of basic microcirculatory parameters in rat skeletal muscle and ileum is acceptable when using SDF imaging technique according to a highly standardized protocol and with appropriate fixation device. SDF imaging represents promising technology for experimental and clinical studies., Z. Turek, V. Černý, R. Pařízková., and Obsahuje bibliografii a bibliografické odkazy
Let Q = (qn)n=1∞ be a sequence of bases with qi ≥ 2. In the case when the qi are slowly growing and satisfy some additional weak conditions, we provide a construction of a number whose Q-Cantor series expansion is both Q-normal and Q-distribution normal. Moreover, this construction will result in a computable number provided we have some additional conditions on the computability of Q, and from this construction we can provide computable constructions of numbers with atypical normality properties., Dylan Airey, Bill Mance, Joseph Vandehey., and Obsahuje seznam literatury
Cíl: Vyšetření čichu Novým testem libosti pachů (New Test of Odor Pleasantness; NTOP) umožňuje hodnocení chemosenzorické percepce v klinické praxi. Výhodou je možné použití i u pacientů s kognitivním deficitem a u dětských pacientů. Cílem studie bylo stanovit normální (fyziologické) hodnoty NTOP u zdravé populace. Soubor a metodika: Vyšetřeno bylo 236 zdravých osob ve věkovém rozmezí od 16 do 93 let. Nový test libosti pachů obsahuje 29 výrazně hédonicky zabarvených pachových látek a tři látky s výraznou trigeminovou složkou. Vyšetřovaný měl po přičichnutí označit ze čtyř možností nejpřiléhavější pro danou pachovou látku: voní, neutrální, zapáchá a výrazně zapáchá (nebo dráždí). Na základě nejčetnějších odpovědí osob kontrolní skupiny ve věkovém rozmezí 16–35 let bylo nastaveno bodové hodnocení. Výsledky NTOP byly porovnány se standardizovanými testy subjektivní olfaktometrie OMT (Odourized Markers Test) a Sniffin’ Sticks (část identifikace). Výsledky: V Novém testu libosti pachů byl medián bodového zisku kontrolní skupiny 20 bodů, ve skupině 36–55 let 19,5 bodu a ve skupině > 56 let 17 bodů. Za nejnižší ještě normální bodový zisk byl stanoven 10. percentil kontrolní skupiny, který byl 16 bodů. Hodnota mediánu v souboru klesá s věkem. Statisticky významný pokles je patrný především po 56. roce věku. Závěry: Nový test libosti pachů vykazuje obdobnou charakteristiku jako standardně užívané testy subjektivní olfaktometrie. Současně však test přináší jinou informaci o čichových schopnostech osob. Normální hodnoty zdravé populace jsou klíčové pro posouzení čichu Novým testem libosti pachů v klinické praxi., Objective: Olfactory test of odor pleasantness may prove to be additions to comprehensive chemosensory test batteries used in clinical settings. The goal of our work was to establish normative data of the New Test of Odor Pleasantness (NTOP). Methods: A total of 236 healthy participants aged 16 to 93 years were included in the study. NTOP is based on classification of 29 odorants and three chemicals with trigeminal component. The participants were asked to categorize the hedonic tone of the odorant into four classes: pleasant, neutral, unpleasant, and fetid (very unpleasant). The normative data were determined based on results of persons of 16 to 35 years old. The NTOP was compared with two standard tests – Odourized Markers Test (OMT) and Sniffin’ Sticks (identification). Results: Median of the NTOP was of 20 in group of age 16–35 years, 19.5 in group of age 36–55 years and 17 in group of > 56. Tenth percentile of the age group 16–35 was 16 points, which is considered as lowest normal points scored. The median numbers of points decreases with age. There is statistically significant decrease in the olfactory capability with increasing age (> 56 years old). Conclusion: NTOP has a similar characteristics as the standard tests of subjective (psychophysical) olfactometry. At the same time the test give us information different from other olfactory tests. The goal of study was to determine the normal value the NTOP of healthy persons in Czech population. Key words: olfaction – odour pleasantness – subjective olfactometry – normative date 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 P. Brothánková, J. Vodička
Cíl: Test Reyovy‑Osterriethovy komplexní figury (ROCFT) patří k široce užívaným neuropsychologickým metodám zaměřeným na vizuální paměť a zrakově‑konstrukční schopnosti. Je považován za test citlivý k časným projevům různých kognitivních poruch. Cílem předkládané práce je připravit normativní data k testu ROCFT pro českou populaci vyššího věku. Soubor a metodika: Soubor 455 osob (250 žen a 205 mužů) starších 60 let, které splnily kritéria pro zařazení, byl vyšetřen neuropsychologickou baterií v rámci Národní normativní studie kognitivních determinant zdravého stárnutí. Sledovány byly vlivy věku, pohlaví a vzdělání na výkon v testu. ROCFT byl administrován v adaptaci podle Meyerse a Meyersové (1995). Výsledky: Výkon v ROCFT klesá ve všech testových proměnných s věkem. Prokázali jsme dále signifikantní vztahy mezi výkonem a pohlavím či vzděláním ve všech podmínkách ROCFT (v kopii, reprodukci po 3 a 30 min i rekognici). Výkony v jednotlivých podmínkách testu mezi sebou významně korelují. Závěry: Na základě regresního modelu jsme připravili rovnice k výpočtu T skórů pro všechny testové proměnné ROCFT. Vytvořené normy jsou demograficky korigovány s ohledem na věk, pohlaví a vzdělání pro české dospělé starší 60 let., Aim: The Rey-Osterrieth Complex Figure Test (ROCFT) is a widely used measure of memory functioning and visuoconstructive abilities. It is considered to be a sensitive diagnostic tool for the evolution of cognitive impairment. The aim of the present study was to determine the normative values for the ROCFT in a population of older Czech adults. Sample and methods: A sample of 455 subjects (250 women and 205 men) above 60 years of age fulfilled the inclusion criteria and was assessed with a battery of neuropsychological tests as part of National Normative Study of Cognitive Determinants of Healthy Ageing. We examined the effect of age, gender, and education level on the test performance. The ROCFT used in this study was developed by Meyers and Meyers (1995). Results: Our analyses revealed a significant age-related decline in ROCFT performance and significant relationships between gender and education in all ROCFT measures (copy, reproduction after 3 and 30 min and recognition trial). Moreover, the performance correlated significantly across all test measures. Conclusions: Based on regression models, we provide the reader with equations to calculate T scores for all ROCFT measures. Furthermore, normative data corrected for age, education and gender are available for healthy adults over a 60 years of age. Key words: Rey-Osterrieth Complex Figure Test – normative data – healthy older adults – visual memory 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 K. Drozdová, H. Štěpánková, J. Lukavský, O. Bezdíček, M. Kopeček
High frequency oscillatory ventilation (HFOV), contrary to conventional ventilation, enables a safe increase in tidal volume (VT) without endangering alveoli by volutrauma or barotrauma. The aim of the study is to introduce the concept of normocapnic high frequency oscillatory hyperventilation and to assess its effect upon oxygen gain under experiment al conditions. Laboratory pigs (n=9) were investigated under total intravenous anesthesia in three phases. Phase 1: Initial volume controlled HFOV period. Phase 2 : Hyperventilation - VT was increased by (46 ± 12) % when compared to normocapnic VT during phase 1. All other ventilatory parameters were unchanged. A significant increase in PaO 2 (by 3.75 ± 0.52 kPa, p<0.001) and decrease in PaCO 2 (by -2.05 ± 0.31 kPa, p<0.001) were obtained. Phase 3: Normocapnia during hyperventilation was achiev ed by an iterative increase in the CO 2 fraction in the inspiratory gas by a CO2 admixture. All ventilatory parameters were unchanged. A significant increase in PaO2 (by 3.79 ± 0.73 kPa, p<0.001), similar to that which was observed in phase 2, was preserved in phase 3 whereas normocapnia was fully re-established. The concept of high frequency normocapnic hyperventilation offers a lung protective strategy that significantly improves oxygenation whilst preserving normocapnia., K. Roubík, J. Pachl, V. Zábrodský., and Obsahuje bibliografii a bibliografické odkazy
Climate change may facilitate shifts in the ranges and the spread of insect pests, but a warming climate may also affect herbivorous insects adversely if it disrupts the locally adapted synchrony between the phenology of insects and that of their host plant. The ability of a pest species to colonize new areas depends on its ability to adjust the timing of phenological events in its life cycle, particularly at high latitudes where there is marked seasonality in temperature and day length. Here we incubated eggs of three species of geometrid moth, Epirrita autumnata, Operophtera brumata and Erannis defoliaria from different geographical populations (E. autumnata and O. brumata from Northern Finland, E. autumnata and E. defoliaria from Southern Finland and all three species from Germany) in a climate chamber at a constant temperature to determine the relative importance of geographic origin in the timing of egg hatch measured in terms of cumulative temperature sums (degree days above 5°C, DD5); i.e. the relative importance of local adaptation versus phenotypic plasticity in the timing of egg hatch. In all three species, eggs from northern populations required a significantly lower temperature sum for hatching than eggs from southern populations, but the differences between them in temperature sum requirements varied considerably among species, with the differences being largest for the earliest hatching and northernmost species, E. autumnata, and smallest for the southern, late-hatching E. defoliaria. In addition, the difference in hatch timing between the E. autumnata eggs from Southern Finland and Germany was many times greater than the difference between the two Finnish populations of E. autumnata, despite the fact that the geographical distances between these populations is similar. We discuss how these differences in hatching time may be explained by the differences in hatch-budburst synchrony and its importance for different moth species and populations. We also briefly reflect on the significance of photoperiod, which is not affected by climate change. It is a controller that works parallel or in addition to temperature sum both for egg hatch in moths and bud burst of their host plants., Julia Fält-Nardmann, Tero Klemola, Mechthild Roth, Kai Ruohomäki, Kari Saikkonen., and Obsahuje bibliografii