• MeSH
• přežití MeSH
• regresní analýza MeSH
• výzkum statistika a číselné údaje   MeSH

• Konspekt
• Kombinatorika. Teorie grafů. Matematická statistika. Operační výzkum. Matematické modelování
• NLK Obory
• přírodní vědy
• NLK Publikační typ
• kolektivní monografie

• MeSH
• lékařství MeSH
• statistika jako téma MeSH

• Konspekt
• Statistika
• NLK Obory
• statistika, zdravotnická statistika

• MeSH
• biometrie MeSH
• statistika jako téma MeSH

• Konspekt
• Statistika
• NLK Obory
• statistika, zdravotnická statistika
• management, organizace a řízení zdravotnictví

OBJECTIVES: A competing risk (CR) model distinguishing adhesive, cohesive and mixed failures as competing events was used for the analysis of micro-tensile bond strength (μTBS) data and compared with a conventional failure mode non-distinguishing survival model. METHODS: Fifty human molars were bonded using five universal adhesives (n = 10) and subdivided according to aging conditions (24-h water storage, thermocycling). After μTBS to dentin was tested, a fractographic analysis was performed using scanning electron microscopy. Survival analyses of the μTBS data were performed using both a failure mode distinguishing Weibull CR model, and a conventional failure mode non-distinguishing Weibull model. Weibull shape (m) and scale (σθ) parameters were calculated for both models using the maximum likelihood estimation method, and strength at 10 % probability of failure, σ0.10, was estimated. Groups were compared using 95 % confidence intervals. RESULTS: CR-model estimates of σθ and σ0.10 for adhesive failures were higher than those of the conventional model, more markedly in groups with lower percentages of adhesive failures. CR-model strength estimates for cohesive failures were similar in all groups regardless of their bond strengths and failure mode distributions. SIGNIFICANCE: Merging all bond-strength data into one dataset irrespective of the failure mode may result in a severe underestimation of bond strength, especially in groups with low incidence of adhesive failures. Bond-strength data analysis using a CR model could provide more accurate estimates of bond strength, and strength estimates for cohesive failures which were apparently independent of bond strength could serve as an internal validity indicator of the CR model.

• MeSH
• analýza dat MeSH
• dentin MeSH
• dentinová adheziva * MeSH
• lidé MeSH
• pevnost v tahu MeSH
• pryskyřičné cementy MeSH
• složené pryskyřice MeSH
• testování materiálů MeSH
• vazba zubní * MeSH
• zubní cementy MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Survival of facultative ectoparasites, e.g. bed bugs (Cimex spp.), is more intensely affected by climatic factors, namely temperature, than that of permanent ectoparasites. The ontogenetic time of the bat bug (Cimex pipistrelli) in bat roosts is limited by different survival rates under different temperatures in particular nymphal stages. This limitation could affect bug densities and cause asynchrony between the ectoparasite and bat reproductive cycle. Therefore, bug survival under different temperatures was tested in the laboratory. Survival success was evaluated by three types of survival analyses: Kaplan-Meier estimation, the Cox proportional hazards model and Weibull parametric regression. The bugs survived for only a few hours at 45 degrees C; however, such a high temperature was never found in natural roosts. Different survival probability among different ontogenetic stages was found at the temperatures of 5-35 degrees C, and it was the highest in adult females and nymphs of fourth and fifth instar. Early instars first to third were found to be the most sensitive with the highest mortality of all stages studied and having their best survival at 5 degrees C. The hazard rate ratio of Weibull regression shows the low daily failure rate of 2.23-4.34% within the span of 5-35 degrees C. C. pipistrelli had the shorter life cycle and the better survival at higher temperature (35 degrees C) than C. lectularius. The ability of the former to survive high temperatures could be the consequence of its long-term coexistence with bats preferring crevice-like roosts or attics which become overheated during the summer months.

• MeSH
• analýza přežití MeSH
• štěnice fyziologie   MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: We present results from a secondary prevention trial of coronary heart disease (CHD) in the Czech male population from northern Bohemia with the history of myocardial infarction (MI) and high prevalence of metabolic syndrome. We compare several approaches to analyzing survival data from our study in terms of respective model assumptions. METHODS: While both the Cox and Weibull survival regression models assume proportionality of the hazard functions over time, in many instances this assumption appears incompatible with the data at hand. Gray's implementation of flexible models using penalized splines allows for a more realistic assessment of the covariate effects which may vary over time. RESULTS: Gray's model results revealed a steady decline in the age-adjusted intervention effect over time, which remained significant until about 2.7 years of follow-up. This was in contrast with the results obtained from the Cox and Weibull models which suggested an overall risk reduction due to intervention during the total follow-up of 6.7 years. Survival estimates based on the Cox and Gray models are shown for the two treatment groups and selected sample quantiles of the age distribution for illustration. CONCLUSIONS: Gray's time-varying coefficients model facilitated a more realistic assessment of the intervention effect. Using suitable historical controls with MI history the effect of intervention was found to gradully diminish over time.

• MeSH
• analýza přežití MeSH
• dospělí MeSH
• financování organizované MeSH
• infarkt myokardu komplikace   MeSH
• koronární nemoc komplikace   prevence a kontrola   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metabolický syndrom epidemiologie   komplikace   MeSH
• prevalence MeSH
• proporcionální rizikové modely MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Geografické názvy
• Česká republika MeSH

Pseudocoloring algorithms embedded in the software of thermal cameras gradually colorize original intensity thermograms generated by detecting temperatures and contrast. Maximum and minimum based algorithms, however, executed by thresholding, applied to intensity thermograms for revealing and coloring the outliers instead. Although the common pseudocoloring protocols employed for general purposes may provide crucial information on the superficial contrast between radiation emitted by various sources; their common kernel is not sufficient for detecting and differentiating high radiated regions from surrounding areas, which is mandatory for recognition of abnormalities. Therefore, we propose novel imaging methodology based on Nakagami and related distributions, including gamma, Rayleigh, Weibull, chi-square and exponential, for enhancing thermal images and also for creating adequate discrimination. We initially define the boundaries of tumor and surrounding area in a synthetically generated breast thermogram already diagnosed as retroareolar tumor. Using Nakagami and transformations supported by mathematical foundations, we conducted several experiments to find the discrimination factor of the pseudocoloring techniques by calculating difference of average contrast between the tumor and the surrounding area. The performance is greatly encouraging that we achieved considerably better discrimination factor, designated for this study, up to 106.80 compared to the results of existing built-in pseudocolorization methods computed as 11.56.

• MeSH
• barva MeSH
• lidé MeSH
• nádory prsu diagnostické zobrazování   MeSH
• počítačové zpracování obrazu metody   MeSH
• strojové učení MeSH
• termografie metody   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Odborný kapesní průvodce primární a sekundární prevence byl připraven týmem renomovaných odborníků (vychází ze všech dostupných amerických a evropských doporučení) a je určen odborné lékařské veřejnosti pro lepší odhad rizika ICHS u konkrétního nemocného. V knize jsou přehlednou formou (především v tabulkách a grafech) zhuštěny základní informace důležité pro určování preventivních postupů u ICHS a dalších kardiovaskulárních chorob s ohledem na snižování lipidů v potravě. Velmi odborné texty.

• MeSH
• hodnocení rizik MeSH
• koronární nemoc prevence a kontrola   MeSH
• rizikové faktory MeSH
• Publikační typ
• průvodce MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• kardiologie

Vysokoškolská učebnice, která se zaměřuje na matematickou statistiku.; Výhodná nabídka Základy matematické statistiky - Jiří Anděl

• MeSH
• matematika MeSH
• statistika jako téma MeSH

• Konspekt
• Kombinatorika. Teorie grafů. Matematická statistika. Operační výzkum. Matematické modelování
• Učební osnovy. Vyučovací předměty. Učebnice
• NLK Obory
• přírodní vědy
• statistika, zdravotnická statistika
• NLK Publikační typ
• učebnice vysokých škol

The bonding performance of dental adhesives is most frequently evaluated using the micro-tensile bond strength (μTBS) test. Despite lacking evidence, peripheral specimens are often discarded to avoid regional variability. This study, therefore, examined whether μTBS to central and peripheral dentin differed. Dentin surfaces of extracted human molars were bonded with various self-etch adhesives, built up with a resin composite, cut into beams, and stressed in tension. Failure mode was classified as adhesive, cohesive in dentin, or other using scanning electron microscopy. Since cohesive failures in dentin were frequent and could confound μTBS results, the data from central/peripheral dentin were analyzed using a Weibull competing risk (CR) model distinguishing failure modes, and its outcomes were compared to a conventional failure mode non-distinguishing Weibull model. Based on the strength data of cohesively failed specimens, the CR model also estimated the strength of dentin. For comparison, the ultimate tensile strength (UTS) of dentin was measured in both regions. The conventional model suggested that peripheral μTBS was higher than central μTBS. Conversely, the CR model disclosed no significant difference in μTBS between the regions but indicated a higher strength of peripheral dentin. This finding was confirmed by UTS measurements, and further supported by the significantly higher incidence of cohesive failures in central dentin. Therefore, peripheral specimens can be used in the μTBS test as well as central ones, but a CR model should be used for statistical analysis if cohesive failures in dentin are frequent, as the strength of peripheral dentin is higher.

• MeSH
• dentin MeSH
• dentinová adheziva * MeSH
• lidé MeSH
• pevnost v tahu MeSH
• pryskyřičné cementy MeSH
• složené pryskyřice MeSH
• testování materiálů MeSH
• vazba zubní * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH