Abstract: Modern clinical observations focused on the increasing complications at the open mandible fracture, which indicated about severe immune suppression in patients with this pathology. For estimation cellular immunity in a peripheral blood there were examined 25 patients in basic group (15 men, 10 women) with mandible fracture, complicated with abscess of a bone wound; control group included 20 practically healthy persons (10 men and 10 women). To assess cellular immunity in the peripheral blood were determined: absolute number of leukocytes, relative amount of lymphocytes; phagocytic activity. Determination relative number of T–lymphocytes (phenotype CD2+, СD3+) and B – lymphocytes (phenotype СD22+) was performed by method of immunofluorescence with monoclonal antibodies. In a case of mandible fracture, complicated with abscess of bone wound and leukocytosis, in the patients were reduced parameters of cellular immunity: on 40.3% – phagocytic index, on 47.7% – phagocytic number, on 43.9% – content of CD2+– and CD3+– lymphocytes. Content of null cells was increased on 76.8 %
Abstract: Bacterial cellulose used for many membrane applications such as artificial dura mater membrane. This research aimed to determine the effects of glycerol concentration variation as plasticizer on physical and biological characteristics of bacterial cellulose-chitosan biocomposite membrane.Bacterial cellulose-glycerol membrane was soaked for six hours in 0.5% chitosan solution together with glycerol at variuos concentrations of 0.5%, 1%, 1.5%, and 2% using freeze dry method. Based on results of FTIR test, there is a crosslinking between-OH groups in bacterial cellulose and chitosan-glycerol. Meanwhile, results of the physical characteristic tests showed tensile strength value of 29.40 MPa for the control sample and 142.24 MPa for samples of bacterial cellulose-chitosan added 2% glycerol. It indicates that the addition of glycerol can increase tensile strength value. Results of morphological test, depicted pore size of 93.30-216 nm. Results of the degradation test demonstrated that samples added 2% glycerol degraded as much as 50.15% for 2 weeks. Meanwhile, results of the cytotoxicity test indicated that all of samples were not toxic. Finally, it can be concluded that the best result of the characterization analysis was found on the samples added 2% glycerol although they have not yet fulfilled the standard value of artificial dura mater.
Abstract: In this paper we studied the behavior of some impression materials such as alginate, condensation and addition silicones, considering the following parameters: the reproductive capacity of morphological details - dimensional stability - the ability to reproduce with accuracy the ratio between morphological elements. The essential conditions that an impression material should fulfill are plasticity, fidelity, flexibility, good mechanical strength, dimensional stability, suitable setting time and compatibility with materials from which the models are manufactured.The study results indicated that condensation silicones present the highest volumetric changes, their contraction being the result of the evaporation of volatile byproducts.The dimensional stability of fingerprint materials is one of the variables that contribute to the accuracy or inaccuracy of dental prostheses, other factors being represented by the changes occurring during the preparation of the fingerprint material as well as the fingerprinting techniques.
Abstract: The purposes of this study were to explore the biomechanical variations of vertical jump performance in well-trained young group before and after passive static stretching (PSS) of knee flexors muscles and to further discuss how the passive static stretching (PSS) influences vertical jump performance in order to provide a more effective warm-up routine and theoretical basis for physical education (PE) teachers and coaches. 15 male middle school students without any injury histories on lower limbs in the past 3 months were included in this study. Subjects with markers on the lower limbs performed vertical jump performance before and immediately after PSS of knee flexors muscles, respectively. A Vicon motion capture system was used to collect the kinematic data of lower limb and Kistler force platform simultaneously recorded the ground reaction force (GRF) during vertical jump. Significant differences were also found in the kinematics part. In sagittal plane, the hip, knee and ankle highest flexion angles were greater after PSS when take-off (hip: p< 0.05; knee: p< 0.01; ankle: p< 0.05); while the hip and knee highest flexion angles were greater before PSS when landing (hip: p< 0.01; knee: p< 0.05). These results showed that the increased range of motion (ROM) of hip, knee, and ankle because of PSS could boost the explosive extension of lower limb during take-off, which can potentially improve vertical jump performance, although the peak value of GRF after PSS was lower. Therefore, the PSS applied only on knee flexors muscles may have an acute effect on enhancing the vertical jump performance for well-trained young group and should be added to warm-up exercises in middle school sports class and sports training.
Abstract: The static decoupling performance is closely related to the efficiency of the bionic elbow joint mechanism. The bionic elbow joint has good static decoupling and has high efficiency and carrying capacity. First, the movement structure and characteristics of the elbow joint are analyzed, a kind of bionic elbow joint is proposed, the position inverse solution is deduced, and force Jacobin matrix of the bionic elbow joint is obtained. Second, the static coupling performance evaluation index and the global static coupling performance index are established, the performance atlas are drawn. Thirdly, by use of the Monte Carlo method the structural parameters of the bionic elbow joint are optimized and selected based on the spatial model theory, and a novel the bionic elbow joint is designed based on parameters optimization, and the static decoupling is verified by the simulation experiment of the bionic elbow joint. The analysis results shows the static decoupling performance of the bionic elbow joint is symmetrical, and with the working space of the attitude output angle increases, the static decoupling decreases gradually. Structural parameters and have great influence on the global static decoupling performance. The structural parameters of is 90mm, is 70mm,and is 30mm, the bionic elbow joint has good static decoupling. This paper lays a foundation for further analysis and research of the bionic elbow joint.
Abstract: Iron oxide nanoparticles (MNPs) was synthesized by coprecipitation of Fe+2 and Fe+3 into highly basic media, followed by coating with chitosan (CH) and polyethylene glycol (PG) to forming CH-MNPs and PG-MNPs nanoparticles, respectively. Kojic acid (Kj) drug was loaded on the CH-MNPs and PG-MNPs nanoparticles to forming Kj-CH-MNPs and Kj-PG-MNPs nanocomposites. The potential cytotoxicity of free Kj, MNPs, Kj-CH-MNPs and Kj-PG-MNPs nanocomposites was evaluated using skin cancer cells (B16-F10 melanoma cells) and normal skin cell (Human Dermal Fibroblasts murine). Kj at concentrations in the range 1.562–50 μg/mL did not affect on the viability of normal skin cell and skin cancer cells during a 72-hours incubation. The Kj-CH-MNPs and Kj-PG-MNPs nanocomposites exhibit significant cytotoxicity in skin cancer cells in a dose-dependent manner with an IC50 value 47.1 and 8.4 μg/mL, respectively.
Abstract: Various ball and socket-type designs of cervical artificial discs are in use or under investigation. All these disc designs claim to restore the normal kinematics of the cervical spine. In this study, we are interested in the cervical prosthesis, which concerns the most sensitive part of the human body, given the movements generated by the head. The goal of this work is to minimize the constraints by numerical shape optimization in the prodisc-C cervical spine prosthesis in order to improve performance and bio-functionality as well as patient relief. Prodisc-C cervical spine prosthesis consists of two cobalt chromium alloy plates and a fixed nucleus. Ultra-high molecular weight polyethylene, on each plate there is a keel to stabilize the prosthesis; this prosthesis allows thee degrees of freedom in rotation. To achieve this goal, a static study was carried out to determine the constraint concentrations on the different components of the prosthesis. Based on the biomechanical behaviour of the spine discs, we totally fixed the lower metal plate; a vertical load of 73.6 N to simulate the weight of the head was applied to the superior metallic endplate. After a static study on this prosthesis, using a finite element model, we noticed that the concentration of the Von-Mises stress is concentrated on the peripheral edge core and the concave articulating surface of the superior metallic endplate the numerical. We use the module optimization for 3D SolidWorks for optimize our design, based on the criteria of minimizing stress value. Shape optimization concluded to minimize the equivalent stress value on both joint surface (concave and convex) from 11.3 MPa to 9.1MPa corresponding to a percentage decrease of 19.4% from the original geometry. We conclude that despite the fact that maximum Von Mises stresses are higher in the case of the dynamic load, remains that they are weak. Which is an advantage for the durability of the prosthesis and-also for the bone, because a low stress concentration on the prosthesis will reduce stress concentration generated by the implant on the bone, therefore its risk of fracture reduces.
Abstract: Retinal images are routinely acquired and assessed to provide diagnostic for many important diseases like diabetic retinopathy. People with proliferative retinopathy can reduce their risk of blindness by 95 percent with timely treatment and appropriate follow-up care. The color constancy is used in this context to define the ability of the visual system to estimate an object color transmitting an unpredictable spectrum to the eyes. In this paper, a Gray World method was proposed by assuming the average of the surface reflectance of a typical scene is some pre-specified value. The main idea based on illumination estimated using the statistical region data. The effectiveness of the Gray Word method and normal gray technique was calculated by using Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR). The Gray World achieved the highest PSNR and lowest MSE proved that the image quality was improved. The proposed method can be used to help the ophthalmologist to detect a lesion in the retinal image automatically. Through the contrast variation in retinal images, the disease can be recognized very well.
Abstract: Heart is a complex structure which acts as a blood pump in mammal’s body. It is important to have detail study for the heart structure. Modeling of heart structure gives a better understanding and figure of the heart valve’s movement as well as the fluid flow movement in the heart chamber. In this paper, the heart simulator (Heart-S) on the left ventricle for measuring the blood circulation during cardiac cycle was proposed. Throughout the experimental modeling of heart valve structure by using rhythmic fluid flow in a closed chamber, the relationship between heart valve elasticity and heart valve angle position to the valve opening width were investigated. The main aspect of the present development is to provide a heart simulator apparatus to obtain data for development of artificial heart and for observing the blood circulation measurement. The result shows good agreement on valve elasticity and the velocity of the fluid from the vortex in the heart chamber can be found after the experiment. The novelty of this development is contributing to the study of the optimal vortex formation in the heart chamber and observe the blood circulation measurement.