The presented work is focused on the biomechanical study of the dental disk implant. The first part of the study deals with the strain analysis of the affected bone tissue and the dental implant loaded in the coronoapical direction by force 190 N. The study includes three types of implant anchorge, four degrees (stages) of osseointegration and nine degrees describing the quality of the cancellous bone. Two types of the disk implant were researched: single-disk and double-disk implant. Biomechanical study of the implant was focused on a stress-strain analysis of the affected bone rissue. The highest influence on the stresses in the bone tissue was primarily an implant anchorage. By the application of correlation relationships between Young modulus and the apparent density of the bone tissue - which is measurable in patients - we achieved the variable presented in this study. and Obsahuje seznam literatury
The presented work follows the first part [1], which is focused on the analysis of bone tissue in terms of dependence of bone tissue 'quality' and its subsequent behaviour based on the stress around the disk implant when biting.
This second part is focused on the stress-strain analysis (and tolerability) of disk implants as loaded during the masticating process.
The study includes two types of disk implants (single-disk and double-disk), three types of anchorage, four degrees (stages) of osseointegration in three quality degrees of the cancellous bone. The study, as expected, has shown that the problematic area of he implants is a transition between the implant body and the disk component, where the equivalent stress in the analyzed implants reaches 700 MPa. and Obsahuje seznam literatury
Orthopaedists in the Czech Republic use corrective braces of type Cheneau or Cerny for conservative treatment of non skeletal scoliosis. The brace has force effects on a child spine and if it is used for enough long time the spine defect is corrected. The brace is made individually for each patient in this way: first, the negative plaster form of a child trunk and then the positive plaster form are made. The positive plaster form is deepened in the places where brace has to push on the patient trunk. The laminate brace made according to this plaster form pushes the child trunk like a tight shoe principle. The paper shows the manner of determination and computer algorithms for solving of the stress state in vertebrae and inter-vertebrae discs and the spinal curve correction under brace force effects for a concrete child patient. The pathologic spinal curve deformities are measured on the X-ray of patient. The spine stress state and spine deformation correction are solved as a beam (spine) on an elastic ground (soft tissue). There are used two algorithms. The 1st algorithm solves the spine stress state and deformation under brace force effect given by displacements of trunk surface. The 2nd algorithm has as input the spinal curves of a patient with and without brace measured on the X-rays. The difference of the two curves is the spine deformity corretions and the spine stress state and necessary trunk surface displacement are the results. If the ideal spine curve is set as the curve under brace effect then the trunk surface is equal to the optimal brace form. The calculation algorithm and parameters ware verified with treatment courses. The trunk surface load was checked by sensor plates which ware put into braces to measure the load values between the brace and the child trunk surface. and Obsahuje seznam literatury
Článek vychází ze zkušeností autora, který se po dlouhé praxi ve výuce mechaniky a výzkumu v oboru fyziky polymerů nyní převážně zabývá biomechanikou. Impresionistickou metodou se snaží na několika příkladech ukázat, jak vidí úlohu mechaniky a především mechaniky kontinua a reologie v biomechanice. Zabývá se i otázkou vzájemných vztahů různých profesí v multidisciplinárním oboru. Úlohu mechaniky v biomechanice vidí především v co nejhlubším pochopení fyzikální podstaty biologických dějů a jejich co nejadekvátnějším vyjádřením v rámci fyziky, kterou je však často nutno užívat ve formě podstatně složitější, než je fyzika středoškolská., This article is based on the author's experiences as both a university lecturer of mechanics and a researcher in polymer physics working now in biomechanics. The impression of the role of mechanics in biomechanics is shown on several examples taken mainly from the author's experience. The interrelations of different processes engaged in the multidisciplinary biomechanics are also discussed. The role of mechanics in biomechanics is seen in deep physical understanding of the solved problem and in adequate physical interpretation of the gained results. As the biomechanical problems are often very difficult to solve, the more general physics that is that taught at grammar schools must be used. The physician's knowledge of the human body functions are so deep that only the main features of the knowledge may be expressed in physical terms even if very advanced theories are used., Antonín Havránek., and Obsahuje bibliografii
Pro řadu biomedicínských aplikací je zásadní interakce mezi biologickým prostředím a povrchem pevné látky. Diamant jako materiál sdružuje v tomto ohledu výborné polovodičové, mechanické, chemické i biologické vlastnosti a lze ho připravovat synteticky i na velké plochy. Zde ukazujeme, jaký vliv má atomární zakončení povrchu diamantu na uspořádání proteinů a buněk a jak toto biologické rozhraní naopak ovlivňuje jeho elektronické vlastnosti. Dosažené poznatky jsou přínosné pro využití unikárních vlastností diamantu v medicíně a dalších oborech., Understanding interactions between the biological environment and solid state surfaces is crucial for a wide range of biomedical applications. In this context, diamond as a material merges excellent semiconducting, mechanical, chemical as well as biological properties and it can be prepared synthetically even at large areas. here we show how atomic termination of diamond surfaces inluences arrangement of proteins and cells and how such biological interface influences electronic properties of diamond. Attained knowledge is fundamental for employing diamond unique properties in medicine and other fields., Bohuslav Rezek, Egor Ukraintsev, Marie Krátká, Alexander Kromka, Antonín Brož, Marie Kalbáčová., and Obsahuje bibliografii
Biometric relationships between bone dimensions and body size are presented for topmouth gudgeon Pseudorasbora parva and sunbleak Leucaspius delineatus, two invasive fish species in the UK. This study also provides a tool for identification of these species using key bones. Such information facilitates the assessment of the potential role of these invaders in the diet of piscivorous fauna.
Biometric data are presented for common freshwater fish species in England and Wales. These enable the lengths and weights of fish in the diet of piscivorous fauna to be estimated from measurements of bones and scales that are recovered from faeces and stomach contents. Use of these data was demonstrated by reconstructing the length composition of species in the diet of cormorants from their faeces and an otter from its stomach contents. Both species were shown to be exploiting common size classes of abundant fish species in their home range.
Biometric data are typically used for the purposes of unique identification of a person. However, recent research suggests that biometric data gathered for the purpose of identification can be analysed for extraction of additional information. This augments indicative value of biometric data. This paper illustrates the range of augmented indicative values of the data as well as identifies crucial factors that contribute to increased vulnerability of data subjects., Alžběta Krausová, Hananel Hazan, Ján Matejka., and Obsahuje bibliografické odkazy
To this day five Gobio gobio subspecies in northern, western and central Anatolia, in Turkey have been classified. Some subspecies were described based on 2-4 specimens by B a t t a l g i l (1942, 1944), L a d i g e s (1960), B ă n ă r e s c u & N a l b a t (1973), B ă n ă r e s c u (1992), B ă n ă r e s c u (1999). In this study, Gobio gobio specimens from the type localities of various running waters and lakes of norht, norhwest and central Anatolia were collected and ANOVA (analysis of variance), cluster analysis and canonical discriminant analysis were applied to fifty variables (eight meristic and forty-two metric characters derived from thirty-four measured or counted variables) to show the main differences between them. From these statistical analyses, Gobio gobio specimens were placed in one of three groups: G1 Beyşehir Lake; G2 Sakarya River Basin, Gerede and Melendiz Stream; G3 İnsuyu Stream, southwards from Tuz Lake. Measurements Standard length/Head height (SL/hH), Head length/Head height (C/hH), Standard length/Head length (SL/C), Predorsal distance/Postdorsal distance (pD/poD), Standard length/Postdorsal distance (SL/poD) and Standard length/Predorsal distance (SL/pD) were important characteristics for distinguishing the populations of Gobio gobio.
e determined regression relat ionships between head bone lengths and body size (standard length and weight) in chub Leuciscus cephalus and Eurasian perch Perca fluviatilis, two species taken frequently by the otter in the River Lee catchment. All relationships yielded significant linear equations, whereas those for bone vs. body weight were logarithmic. Regression slopes for head bones do not differ greatly within species but do across species of the same family.