The goal of this study is to evaluate if promotion of angiogenesis by systemic treatment with an antagomir against miR-92a, a well established inhibitor of angiogenesis, will maximize the benefits of exercise on bone. Ten week old female C57BL6/J mice were subjected to two weeks of external load by four point bending. During the first week of mechanical loading (ML), mice were injected (2.7 mg/kg of bodyweight) with antagomir against miR-92 or control antagomir (3 alternate days via retro-orbital). No difference in tissues weights (heart, kidney, liver) were found in mice treated with miR-92 vs. control antagomir suggesting no side effects. Two weeks of ML increased tibia TV, BV/TV and density by 6-15 %, as expected, in the control antagomir treated mice. Similar increases in the above parameters (7-16 %) were also seen in mice treated miR-92 antagomir. Administration of miR-92 antagomir was effective in reducing levels of mir-92 in heart, liver and skeletal muscle and in contrast, expression levels of two other microRNA’s miR-93 and miR-20a remain constant, thus suggesting specificity of the antagomir used. Surprisingly, we failed to detect significant changes in the expression levels of vascular genes (VEGF, CD31 and Tie2) in heart, liver or skeletal muscle. Based on these findings, we conclude that systemic administration of antagomir against miR-92 while reduced expression levels of miR-92 in the tissues; it did not significantly alter either angiogenic or osteogenic response, thus suggesting possible redundancy in miR-92 regulation of angiogenesis., A. Sengul, ... [et al.]., and Obsahuje seznam literatury
The paper continues the description of constitutive behaviour of matters, the overview of which was presented in the previous part of this paper (Part I - basic and simple constitutive models). The definition and systemization of constitutive models was presented there and basic and simple models were described in detail. In the same systemic approach, combined constitutive models of materials (solid matters) are presented in this paper (Part II). It analyzes the more complex types of constitutive behaviour and presents a comprehensive overview of their responses in standard tension tests (stresses as functions of strain magnitude and strain rate), as well as the simplest mathematical interpretations of viscoelastic, elastic-plastic, viscoplastic and elastic-viscoplastic matters are presented, except for various types of anisotropic materials and their constitutive models (all the models are presented as isotropic only). On the base of both of these papers, the chapter on constitutive models was published in [1]. and Obsahuje seznam literatury
The paper presents a systemic overview of constitutive models, i.e. mathematical or graphical representations of responses of a matter iniciated by its activation coming from its surroundings (especially stress- or strain-controlled loadings in mechanics). Various states of matter showing different behaviour are related with different distances among particles of the matter and their mutual movements. However, in oppostie to the previous centuries, when different approaches and methods were developed and used for description of various types of matters (in solid mechanics, hydromechanics, thermodynamics etc.), recently more and more often solid mechanics meets materials showing some features of fluids (e.g. creep, flow), and interactions of matters in different states (e.g. solid-liquid) need to be solved as well. The presented paper, together with another consequent one (Part II), creates a set of two related articles aiming at facilitating you the orientation in various types of constitutive equations. It presents graphical representations of basic mechanical resposnes (stress as a function of strain magnitude and strain rate, creep stress relaxation), as well as their simplified mathematical substantiation. Some more complex types of constitutive models will be presented in part II. On the base of these papers, the chapter on constitutive models was published in [1]. and Obsahuje seznam literatury
The impact on blood pressure of two vasodilating mechanisms, underlied by vascular smooth muscle hyperpolarization, was studied and compared to that induced by nitric oxide (NO) mechanism. Systemic blood pressure, after inhibitory intervention in arachidonic acid metabolism (cytochrome P-450 inhibition by miconazole 0.5 mg/100 g b.w.), one of the hyperpolarizing pathways, did not change. After the inhibition of the action voltage-dependent K+ channels operator (by 4-aminopyridine 0.1 mg/100 g b.w.)
, the other hyperpolarizing pathway, blood pressure declined slightly (from 132.3±3.2 mm Hg to 116.5±5.0 mm Hg, P<0.05). Inhibition of nitric oxide production (L-NAME 5 mg/100 g b.w.) increased blood pressure considerably (123.5±2.7 mm Hg to 155.4±3.1 mm Hg, P<0.001). After inhibition of the hyperpolarizing pathway by miconazole, hypotension induced by acetylcholine (Ach, 10 μg) represented 63.0±1.9 mm Hg vs control value 78.6±5.2 mm Hg (P<0.001), by bradykinin (BK) (100 μg) 59.4±3.9 mm Hg vs control value 71.2±6.1 mm Hg (P<0.05). After inhibition of the hyperpolarizing pathway by 4-aminopyridine, hypotension induced by ACh (10 μg) achieved 64.6±2.5 mm Hg vs control value 78.4±2.8 mm Hg (P<0.001) and that induced by BK (100 μg)
56.6±5.3 mm Hg vs control value 72.3±2.5 mm Hg (P<0.001). ACh or BK hypotension after the inhibition of the above hyperpolarizing pathways was significantly attenuated. On the contrary, after NO-synthase inhibition the hypotension to ACh was significantly enhanced. Blood pressure decrease after ACh (10 μg) hypotension was 91.8±4.1 mm Hg vs control value 79.3±3.3 mm Hg (P<0.01), and after BK (100 μg) it was 78.4±7.1 mm Hg vs control value 68.3±5.2 mm Hg. A different basal BP response, but equally attenuated hypotension to Ach and BK, was detected after the inhibition of two selected hyperpolarizing pathways. In cotrast, the inhibition of NO production elicited an increase in systemic BP and augmentation of ACh and BK hypotension. The effectiveness of further hyperpolarizing mechanisms in relation to systemic BP regulation and nitric oxide level remains open.
Příspěvek podává přehled systémů určených pro skladování elektrické energie. Obsahuje základní popis funkčních principů, vhodných aplikací a trendů ve vývoji takových systémů. Následuje vzájemné porovnání jednotlivých systémů a diskuse jejich výhod a nevýhod., This article reviews various electric energy storage systems. The paper contains a basic description of functional principles of particular energy storage systems and also a comparison of different ways of how to cumulate and store electrical energy. Present applications and future trends in the developmnet of such systems are summarized in the article., Martin Zigler., and Obsahuje bibliografii
The rationale for the use of T lymphocytes to fight cancer is the immunogenicity of tumor cells. T cells are capable to recognize and finally to kill tumor cells. Adoptive cell transfer therapies provide the opportunity to overcome tolerogenic mechanisms by enabling the selection and activation of highly reactive T cell subpopulations and by manipulation of the host environment into which the T cells are introduced. The aim of this article is to review the possibilities, limitations and recent clinical experience with this novel anticancer treatment, namely with adoptive immunotherapy using antigen-specific T cells.
We develop a general axiomatic theory of algebraic pairs, which simultaneously generalizes several algebraic structures, in order to bypass negation as much as feasible. We investigate several classical theorems and notions in this setting including fractions, integral extensions, and Hilbert's Nullstellensatz. Finally, we study a notion of growth in this context.