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 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
The study of natural materials, a creating of their similarities from the point of view of constructions, structures and materials is relatively new and a perspective field connecting results of scientific research of biologists, chemists, physicists, material engineers, constructors and designers. At present day a lot of these results were transferred into the industry application. How we can see natural materials could become a source of inspiration on a field of materials, technologies and constructions as well as on the field of nanotechnologies. and Studium přírodních materiálů, vytváření jejich analogií z hlediska konstrukcí, struktur i materiálů je relativně novým a neobyčejně perspektivním oborem, který dokáže spojovat výsledky bádání biologů, chemiků, fyziků, materiálových inženýrů, konstruktérů a designérů. V současné době řada výsledků těchto výzkumů dosáhla i svých průmyslových aplikací. Jak je postupně zjišťováno, přírodní materiály se nám mohou stát zdrojem inspirace v oblasti materiálů, technologií a konstrukcí stejně tak jako v oblasti nanotechnologií.
Projekt Centra kompetence BIORAF se již třetím rokem zabývá biorafinačními procesy, které se zakládají na chemické, biologické a termické přeměně přírodních materiálů z odpadů rostlinného a živočišného původu ze zemědělské výroby i potravinářského průmyslu či z řas na žádané produkty s vysokou přidanou hodnotou. Projekt se řeší s finanční podporou Technologické agentury ČR za koordinace Ústavu chemických procesů AV ČR a ve spolupráci s Vysokou školou chemicko-technologickou, Botanickým ústavem AV ČR a společnostmi Agra, Rabbit, Briklis a Ecofuel. Viz také První rok Centra BIORAF a Aplikace biorafinací. and Olga Šolcová.
Globally, water deficit is one of the major constraints in chickpea (Cicer arietinum L.) production due to substantial reduction in photosynthesis. Photorespiration often enhances under stress thereby protecting the photosynthetic apparatus from photoinhibition. Application of bioregulators is an alternative to counter adverse effects of water stress. Thus, in order to analyze the role of bioregulators in protecting the photosynthetic machinery under water stress, we performed an experiment with two contrasting chickpea varieties, i.e., Pusa 362 (Desi type) and Pusa 1108 (Kabuli type). Water deficit stress was imposed at the vegetative stage by withholding water. Just prior to exposure to water stress, plants were pretreated with thiourea (1,000 mg L-1), benzyladenine (40 mg L-1), and thidiazuron (10 mg L-1). Imposed water deficit decreased relative water content (RWC), photosynthetic rate (P N), quantum efficiency of PSII (Fv/Fm), and enhanced lipid peroxidation (LPO). However, bioregulator application maintained higher RWC, P N, Fv/Fm, and lowered LPO under water stress. Expression of Rubisco large subunit gene (RbcL) was low under water stress both in the Kabuli and Desi type. However, bioregulators strongly induced its expression. Although poor expression of two important photorespiratory genes, i.e., glycolate oxidase and glycine decarboxylase H subunit, was observed in Desi chickpea under imposed stress, bioregulators in general and cytokinins in particular strongly induced their expression. This depicts that the application of bioregulators protected the photosynthetic machinery by inducing the expression of RbcL and photorespiratory genes during water deficit stress., T. V. Vineeth, P. Kumar, G. K. Krishna., and Obsahuje seznam literatury