Papers by Keyword: Human

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Authors: Mehdari Abdessamad, Mohamed Hasnaoui, Mohamed Agouzoul
Abstract: In the recent years, blood flow through an aorta has been the main focus of many investigators. It shows particular interest in analyzing human aortic stiffness and blood flow behavior. Mainly, an unsteady state is applied for incompressible fluid, which is assumed to be newtonian. Artery is considered an elastic tube and the wall boundaries are isotropic. The analytical modeling of blood involves adopting an asymptotic approach according to a small aspect radio, which is inversely proportional to Reynolds number. The wall has been assumed a thin shell, which generates a small axisymmetric vibration. The mathematical model of the wall is developed using the thin shell theory based on geodesic curvature parameter. In the end, the analytical results simulation is applied to have better understanding of the effects of blood flow behavior over the elasticity aortic wall properties.
Authors: Shinobu Kobayashi, Masataka Sakane, Hirotaka Mutsuzaki, Hiromi Nakajima, M. Tanaka, Yutaka Miyanaga, Naoyuki Ochiai
Abstract: We hybridized calcium phosphate (CaP) with human semitendinosus and gracilis (ST/G) tendon grafts using an alternate soaking process. To evaluate quantitatively and histologically assess the CaP hybridized human ST/G tendon grafts, we classified them into three groups according to their soaking time – number of soaking cycle: 30 sec – 20 cycles (Group A), 1 min – 15 cycles (Group B), 3 min – 5 cycles (Group C). The tendon grafts were divided into three parts: tibial end (TE), femoral end (FE) and intra-articular (IA) portion. TE was secured using the Krackow technique with No. 2 nonabsorbable sutures, and an Endobutton-CL (Smith & Nephew, USA) was passed through the looped FE, as performed clinically. Then, the IA portion was covered with the sleeve of a rubber glove to prevent CaP hybridization. More soaking cycles induced greater deposition of CaP in the tendon grafts when the total soaking time was the same. Covering the IA portion with a rubber sleeve prevented of CaP deposition. A large amount of CaP in TE was deposited because suture holes increased the total contact area with the solutions.
Authors: De Wu Liu, Yong Tie Li, De Ming Liu, Pu Ning
Abstract: Human induced pluripotent stem cells is promising for regenerative medicine and tissue engineering. In this chapter, we focus on the culture and characteristics of human induced pluripotent stem cells. The induced pluripotent stem cells were plated on murine embryonic fibroblast feeder cells and expanded in human embryonic stem cells media contained basic fibroblast growth factor. The cells were passaged by collagenase IV digestion method and observed under invert microscope. The expression of alkaline phosphatase was detected by immunocytochemistry. The cultured induced pluripotent stem cells grew well and stability with similar characteristics of human embryonic stem cells. These cells also expressed alkaline phosphatase. They formed embryoid body in feeder-free and suspension culture conditions. The results provide an experimental basis for improvement of induction study and further application to generate patient-specific induced pluripotent stem cells.
Authors: S.M. Mizanoor Rahman, Ryojun Ikeura, Soichiro Hayakawa, Hao Yong Yu
Abstract: We made two objects (hollow metal cylinders) with identical appearance. One was called the constrained object; another was called the unconstrained object. Human subjects lifted the constrained and unconstrained objects separately for various experiment conditions. We compared human’s weight perception between the two types of objects. Results showed that weight perception between constrained and unconstrained lifting was almost the same. In our previous research, we developed a power assist system for lifting objects and determined a psychophysical relationship between actual and perceived weights for the objects lifted with the system [1]. The perceived weights were 40% of actual weights. However, the objects lifted with the system were constrained objects (as they were tied to the force sensor) that might affect the accuracy of the relationship. The results of this paper confirm that the constraint does not affect weight perception too much, which reconfirms that the psychophysical relationship between actual and perceived weights derived in our previous research was correct [1].
Authors: Veronika Kotradyová, Alfred Teischinger
Abstract: 1024x768 The paper deals with the problematic of contact comfort as a part of body conscious design/ human-centred design. Contact comfort consist of a combination of balanced surface temperature, heat transmission, surface roughness, surface elasticity/hardness, sorption activity of the surface in terms of vapour/fluids absorbance, sorption activity of the surface in terms of absorbing the external moisture (e.g. sweat or humidity of air/its condensates), having control over body position, possibilities of maintenance and visual comfort connected with cultural background of users, individual mental and physical setting that is creating overall feeling of comfort. All these parameters are measurable and it is possible to optimize them with an aim to get good solutions that are providing higher contact comfort. Roughness is extremely important for overall feeling of contact comfort it has direct relation also to the other features. The current paper presents also the methodology and results of the pilot study of contact comfort. .Different wood based materials and wood species with different types of surface finishing in comparison with other materials were investigated by using a test chair. Normal 0 21 false false false SK X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Normálna tabuľka"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}
Authors: Jeong Joon Yoo, Kwang Woo Nam, Kyung Hoi Koo, Kang Sup Yoon, Hee Joong Kim
Abstract: The unique characteristics of cell surface molecules on human bone marrow stromal cells (hBMSCs) have not been clearly elucidated. The authors characterized 19 cell surface molecules on culture-expanded hBMSCs obtained from 10 human donors, by flow cytometry, calculated the averages and standard deviations of the expression frequencies of individual surface molecules, and evaluated their expression patterns with respect to donor-dependent variations. Surface molecules expressed at frequencies of more than 80% on cells included, CD49e, CD29, CD90, CD73, CD44, CD105, and CD146, those expressed at frequencies of 20-80% included, Stro-1, CD51, CD54, CD31, CD106, CD163, and CD34, whereas CD49d, CD14, CD144, CD11b, and CD45 were expressed at less than 20%. Substantial donor-dependent variations (>10% standard deviation in expression percentage) were observed in the expressions of CD105, Stro-1, CD51, CD54, CD31, CD106, CD163, and CD34. Our results demonstrate that CD49e, CD29, CD90, CD73, and CD44 can be used as a positive marker for hBMSCs, and that CD144, CD11b, and CD45 could be used as a highly selective negative marker. However, the expressions of CD54, CD31, and CD106 observed in the present study, contradicted prior reports and thus, their expressions remain controversial.
Authors: Masaru Murata, J. Hino, Toshiyuki Akazawa, Katsutoshi Ito, Yukito Hirose, Morio Ochi, Makoto Arisue
Abstract: The aims of this study are to confirm the capacity of hard tissue induction by human demineralized dentin matrics (DDM) and calcified dentin matrics (CDM) in subcutaneous tissues of nude mice, and to report a human pioneering trial following the autotransplantation of DDM for bone augmentation in a case of the atrophied upper jaw. Human DDM and CDM particles were prepared from adult, extracted vital teeth, and were implanted into the subcutaneous tissues of 4-week-old nude mice. DDM induced bone and cartilage independently at 4 weeks after implantation, while CDM did not induce a hard tissue formation. Autogenous DDM prepared from the non-functional second molar of a 58-year-old female were grafted on the atrophied jaw and received to the host. Human dentin can be recycled as autogenous biomaterials for local bone engineering.
Authors: Kazuhide Miyazaki, Takafumi Yoshikawa, Koji Hattori, Noriko Okumura, Jin Iida, Yoshinori Takakura
Authors: Vítězslav Gaja
Abstract: This paper focuses on possibilities in increasing the user comfort of seating furniture in public waiting interiors. There are several aspects helping to achieve the best comfort of sitting, such as appropriate ergonomic design, shape, or material composition. While every of the said aspects have a significant impact on the final comfort, it would be better, or even essential, to adopt a complex view of this issue. One of the complex ways to increase the user comfort is to observe the interaction of the human (the “user”) with the material. The paper describes tactile properties in the interaction with basic types of materials the public gets in direct contact with when sitting in public waiting interiors. The conducted research focuses on tactile properties leading to contact comfort of the most used materials, and analyses the properties in relation to temperature, roughness, hardness and comfort. The four mentioned tactile properties are essential for our goal – an increase in user comfort. The preferred materials were defined according to a preceding terrain survey which explored what materials are most commonly used for present seating furniture. The paper then presents the methodology and results of the research focusing on interaction between the human user and the material. The results of the said research might prove useful for future designing and development of seating furniture which focuses on the user’s sensational balance and calmness, i.e. the optimal comfort.
Authors: Tuan Norhayati Tuan Chik, Shurl Yabi, Mohd Haziman Wan Ibrahim, Nor Azizi Yusoff, Taksiah A. Majid, Rachel Alexius Asiew
Abstract: Abstract. Vibration in building is one of the important problems which need to consider, especially in designing the floor. Floor vibrations are generally caused by dynamic loads applied particularly by human activity especially walking. Although it is specified as low level amplitude, walking induced vibrations can cause discomfort to human occupants and alarming for a certain items of precision sensitive equipment. This paper investigates the vibration response on floor performance due to one, three and five of people walking. Laser Doppler Vibrometer was used to obtain vibration data when people are walking. Further analysis was carried out by using finite element software package ANSYS to simulate the floor under vibration inputs to obtain natural frequency and mode shapes of the floor structure. The vibration data was then analysed in ModalV analysis to generate the vibration response. Then, the results were checked against the vibration criteria level guideline as a crude tool comparison. As a result, the numbers of people walking were influenced the floor performance, which indicated five peoples walking show the highest response up to ISO level due to vibration compared with one people walking.
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