Number of results to display per page
Search Results
1182. A novel carboxymethylated mercaptotriazinoindole inhibitor of aldose reductase interferes with the polyol pathway in streptozotocin-induced diabetic rats
- Creator:
- Soltesova Prnova, M., Ballekova, J., Alena Gajdošíková, Gajodsik, A., and Stefek, M.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, diabetici, diabetics, carboxymethylated mercaptotriazinoindole, aldose reductase inhibitor, polyol pathway, diabetic complications, 14, and 612
- Language:
- English
- Description:
- The aim of the present work was to study the effect of 3- mercapto-5H-1,2,4-triazino[5,6-b]indole-5-acetic acid (CMTI), an efficient aldose reductase inhibitor, on sorbitol accumulation in selected organs of streptozotocin-induced diabetic rats in vivo . In addition, the effect of CMTI on aldose reductase back reaction and on sorbitol dehydrogenase was determined. The model of experimental diabetes in male Wistar rats induced by streptozotocin was used. Experimental diabetes was induced by triple intraperitoneal doses of streptozotocin on three consecutive days. In diabetic rats, significant elevation of sorbitol concentration in the sciatic nerve and eye lenses was recorded. CMTI administered intragastrically (50 mg/kg/day) for five consecutive days significantly inhibited sorbitol accumulation in the sciatic nerve, yet it was without effect in eye lenses of diabetic animals. For aldose reductase back reaction, the substrate affinity of glycerol to aldose reductase was one order lower than that of glyceraldehyde in forward reaction. In addition, the back reaction was much slower, characterized by Vmax value of about 30 times lower than that of the forward reaction. Inhibition of aldose reductase by CMTI was characterized by closely related IC50 values in submicromolar range for both forward and back reactions. No significant inhibition of the second enzyme of the polyol pathway, sorbitol dehydrogenase, by 100 μM CMTI was recorded (I=0.9±2.7 %, n=3). To conclude, the presented results showed the ability of CMTI to affect the polyol pathway in diabetic rats in vivo and represent thus a further step in a complex preclinical evaluation of CMTI as a potential agent for treatment of chronic diabetic complications., M. Soltesova Prnova, J. Ballekova, A. Gajdosikova, A. Gajdosik, M. Stefek., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1183. A novel construction and mechanical principles of five-fingered prosthetic hand
- Creator:
- Žajdlík, Jakub
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- prosthetic, grasp, EMG, hand, and biomechanics
- Language:
- English
- Description:
- This paper presents idea flow, development and construction of an anthropomorphic hand which is intended to be used mainly in prosthetics. Fundamental results of simulations and optimization of grasp are shown. The prototype has been manufactured and the principal functionality of finger mechanism (drive three axes by one string) has been tested. A new mechanical principle has been developed which is based again on an idea of using less actuators then joints with keeping adaptability and functionality of the mechanism. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1184. A novel H-shape fishway with excellent hydraulic characteristics
- Creator:
- Zhang, Di, Liu, Chunming, Shi, Xiaotao, Liu, Yakun, and Qu, Yingmin
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- hydraulic characteristics, vertical-slot fishway, H-shape fishway, T-shape fishway, turbulent kinetic energy, and K-Omega-SST turbulence model
- Language:
- Slovak
- Description:
- Fishway design not only takes into account the swimming abilities of target fishes, but also considers the hydrodynamic characteristics within the fishway. In this study, the flow fields of one vertical-slot fishway (i.e. VSF), five T-shape fishways (i.e. TSF-1~TSF-5) and two H-shape fishways (i.e. HSF-1 and HSF-2) are numerically simulated by solving the three-dimensional Reynolds-averaged Navier-Stokes equations and the K-Omega-SST turbulence model. The numerical results clearly indicate that the hydrodynamic properties of HSF-2 are overall superior to the remaining seven cases, in terms of the time-averaged flow pattern, the time-averaged velocity magnitude, the depth-mean timeaveraged velocity magnitude along the vertical-slot section, the volume percentages of the time-averaged velocity magnitude less than some critical values, and the distribution of the time-averaged turbulent kinetic energy. Therefore, HSF-2 is more friendly for fishes with relatively smaller sizes and weaker swimming capacities to transfer upstream. The novel HSF-2 is firstly proposed in this paper, and it is naturally designed during the process of improving the flow regime. Furthermore, the generalizability of the superiority of HSF-2 over VSF and the original T-shape fishway (i.e. TSF-1) has been exhibited with the aid of the numerical results of four operating conditions (i.e. Q = 400 L/s, 600 L/s, 800 L/s and 1000 L/s).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1185. A novel method for the estimation of soybean chlorophyll content using a smartphone and image analysis
- Creator:
- Rigon, J. P. G., Capuani, S., Fernandes, D. M., and Guimarães, T. M.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorofyl, karotenoidy, chlorophyll, carotenoids, mathematical models, fotosyntetické pigmenty, přenosná zařízení, quinoa, sezam, sójové boby, ricinový olej, tmavě zelený barevný index, vegetační index, smart phone camera, color model, photosynthetic pigments, portable equipment, sesame, soybean, castor oil, pod formation stage, Surinam cherry, dark green color index, vegetation index, 2, and 581
- Language:
- Multiple languages
- Description:
- The development of smartphones, specifically their cameras, and imaging technologies has enabled their use as sensors/measurement tools. Here we aimed to evaluate the applicability of a fast and noninvasive method for the estimation of total chlorophyll (Chl), Chl a, Chl b, and carotenoids (Car) content of soybean plants using a smartphone camera. Single leaf disc images were obtained using a smartphone camera. Subsequently, for the same leaf discs, a Chl meter was used to obtain the relative index of Chl and the photosynthetic pigments were then determined using a classic method. The RGB, HSB and CIELab color models were extracted from the smartphone images and correlated to Chl values obtained using a Chl meter and by a standard laboratory protocol. The smartphone camera was sensitive enough to capture successfully a broad range of Chl and Car contents seen in soybean leaves. Although there was a variation between color models, some of the proposed regressions (e.g., the S and b index from HSB and Lab color models and NRI [RGB model]) were very close to the Chl meter values. Based on our findings, smartphones can be used for rapid and accurate estimation of soybean and Car contents in soybean leaves., J. P. G. Rigon, S. Capuani, D. M. Fernandes, T. M. Guimarães., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1186. A novel reading of Thomas Nagel’s “Challenge” to physicalism
- Creator:
- Tümkaya, Serdal
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- folk psychology, Nagel, objective phenomenology, physicalism, and science of consciousness
- Language:
- Slovak
- Description:
- In passing remarks, some commentators have noted that for Nagel, physicalism is true. It has even been argued that Nagel seeks to find the best path to follow to achieve future physicalism. I advance these observations by adding that for Nagel, we should discuss the consciousness problem not in terms of physical and mental issues but in terms of our desire to include consciousness in an objective/scientific account, and we can achieve this only by revising our self-conception, i.e., folk psychology, to develop a more detached view of experience. Through the project of objective phenomenology, Nagel aims to achieve some sort of objective, detached, and scientific explanation of the subjective nature of experience. This project seeks to make the truth of physicalism intelligible and consciousness more amenable to scientific study, potentially raising an even broader concept than the one physicalism originally proposes.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1187. A numerical investigation of a buoyancy driven flow in a semi-porous cavity: comparative effects of ramped and isothermal wall conditions
- Creator:
- Chandran, Pallath, Sacheti, Nirmal C., and Singh, Ashok K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- rectangular cavity, free convection, brinkman model, coupled flow, ramped boundary condition, and numerical solution
- Language:
- Slovak
- Description:
- Steady two-dimensional natural convection taking place in a rectangular cavity, partially filled with an isotropic porous material, has been investigated numerically using an ADI method. It is assumed that one of the vertical walls of the cavity has a ramped temperature distribution. The vorticity-stream function formulation has been used to solve the set of nonlinear partial differential equations governing the flows in the clear region and the adjoining porous region. The effects of Darcy number and Rayleigh number have been discussed in detail.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1188. A numerical investigation of the modified Sherman systems
- Creator:
- Nikolov, Svetoslav, Nedev, Valentin, and Zlatanov, Vassil
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chaotic dynamics, Sherman system, bifurcation, and maximal Lyapunov exponent
- Language:
- English
- Description:
- The aim of this paper was to demonstrate that it is possible to control the chaos into the Sherman system by linear feedback of own signals. After introducing of the parameter ‘α‘ in the z-equation (α → α + α1 x(t) + α2 y(t) + α3 z(t), we study how the global dynamics can be altered in a desired direction (αn are considered as free parameters). We make a detailed bifurcation investigation of the modified Sherman systems by varying the parameters αn. Finally, we calculate the maximal Lyapunov exponent, where the chaotic motion of modified Sherman system exists. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1189. A numerical study of effects of the manufacture perturbations to contacts of the total hip replacement
- Creator:
- Koukal, Milan, Fuis, Vladimír, Florian, Zdeněk, and Janíček, Přemysl
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- total hip replacement, FEM, roundness, contact pressure, frictional moment, and biomechanics
- Language:
- English
- Description:
- In endoprosthesis surgery there are typically a high percentage of implant defects, these can lead to failure of the whole prosthesis. One type of total hip replacement function loss is acetabular cup loosening from the pelvic bone. This article examines manufacture perturbations as one of the possible reasons for this kind of failure. Both dimension and geometry manufacturing perturbations of ceramic head and polyethylen cup were analyzed. We find that perturbations in the variables analysed here affect considered values of contact pressure and frictional moment. Furthermore, contact pressure and frictonal moment are quantities affecting replacement success and durability. From obtained results we can recommend to fit head and cup with a clearance of between 0 mm andd 0.05 mm. We do not recommend using interference type of fit. Roundness perturbation of ceramic head should not exceed 0.025 mm. and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1190. A numerical study of pressure changes in dead-end pores
- Creator:
- Fathaddin, Muhammad Taufiq, Awang, Mariyamni B., and Ardjani, Karnata
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- dead-end pore, porous media, source, sink, mŕtve póry, pórovité prostredie, zdroj, and odber
- Language:
- Slovak
- Description:
- Dead-end pores are usually present in natural porous media especially in consolidated sandstone and limestone rocks. However, the presence of the dead-end pores is usually ignored. Then, the influences of the dead end pores to the flow system are also neglected. In this paper, pressure changes for the periods of transient and steady state of the dead-end pores are studied using lattice gas automata model. A simulation result is compared with the past works. They show that the model is viable to perform simulation of deadend pore pressure. Some parameters such as pressure distribution and size of neck and body of the dead-end pores are varied to examine their effects. We found that the parameters affect the rate of pressure change during transient period. In addition, the parameters also affect the pressure fluctuation during steady state period. The dead-end pores have function either as source or sink in the transient period depend on initial and injection pressures. During steady state period, the dead-end pores behave both as source and sink since the pressure in the pores fluctuates around an equilibrium pressure between the pressure of dead-end pore and that of main channel at the neck position of dead-end pore. and Takzvané mŕtve póry (neprietočné póry) sa často nachádzajú v prírodných pórovitých prostrediach, predovšetkým v skonsolidovaných pieskovcoch a vo vápencoch. Obvykle sa ich existencii nevenuje pozornosť. Pozornosť sa nevenuje ani ich vplyvu na prúdenie v tomto systéme. V tomto príspevku sú študované zmeny tlaku v mŕtvych póroch počas neustáleného a ustáleného prúdenia s použitím ''lattice gas automata'' modelu. Výsledky simulácie sme porovnali s predchádzajúcimi prácami. Výsledky naznačujú, že tento model je vhodný na simuláciu zmien tlakov v mŕtvych póroch. Vplyv niektorých parametrov, ako je rozdelenie tlakov a tvary ''krčkov'' (spojovacích pórov) ako aj mŕtvych pórov boli menené tak, aby sme mohli pozorovať ich vplyv na prúdenie. Zistili sme, že tieto parametre ovplyvňujú rýchlosť zmien tlakov počas neustáleného prúdenia. Navyše sme zistili, že tieto parametre ovplyvňujú fluktuáciu tlakov počas ustáleného prúdenia. Mŕtve póry môžu počas neustáleného prúdenia fungovať ako zdroje alebo odbery, v závislosti od počiatočného, alebo ''plniaceho'' tlaku. Počas ústáleného prúdenia sa mŕtve póry správajú ako zdroje alebo aj odbery, pretože tlak v póroch fluktuuje okolo rovnovážneho tlaku medzi tlakom v mŕtvych póroch a hlavným kanálom v závislosti od vlastností ''krčku'' mŕtveho póru.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public