• Journal of Biomedical Engineering Research
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• v.27 no.4
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• pp.143-153
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• 2006

The purpose of this work was to assess and quantify the beneficial effects of gas exchange, while testingto the various frequencies of the sinusoidal wave that was excited by the PZT actuator, for patients suffering from acute respiratory distress syndrome (ARDS) or chronic respiratory problems. Also, this paper considered a simulator to design a hollow type artificial lung, and a mathematical model was used to predict a behavior of blood. This simulation was carried out according to the Montecarno's simulation method, anda fourth order Runge-Kutta method was used to solve the equation. The experimental design and procedure are then applied to the construction of a new device to assess the effectiveness of the membrane vibrations. As a result, the vibration method is very effective in the increase of gas transport. The gas exchange efficiency for the vibrating intravascular lung assist device can be increased by emphasizing the following design features: consistent and reproducible fiber geometry, and most importantly, an active means of enhancing convective mixing of water around the hollow fiber membranes. The experimental results showed the effective performance of the vibrating intravascular lung assist device. Also, we concluded that important design parameters were blood flow rates, fiber outer diameter and oxygen pressure drop. Based on the present results, it was believed that the optimal level of blood flow rates was 200$cm^3$/min.

• Geomechanics and Engineering
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• v.24 no.4
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• pp.349-358
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• 2021

The Brazilian test has been widely used to determine the indirect tensile strength of rock, concrete and other brittle materials. The basic assumption for the calculation formula of Brazilian tensile strength is that the elastic moduli of rock are the same both in tension and compression. However, the fact is that the elastic moduli in tension and compression of most rocks are different. Thus, the formula of Brazilian tensile strength under the assumption of isotropy is unreasonable. In the present study, we conducted Brazilian tests on flat disk-shaped rock specimens and attached strain gauges at the center of the disc to measure the strains of rock. A tension-compression bi-modular model is proposed to interpret the data of the Brazilian test. The relations between the principal strains, principal stresses and the ratio of the compressive modulus to tensile modulus at the disc center are established. Thus, the tensile and compressive moduli as well as the correct tensile strength can be estimated simultaneously by the new formulas. It is found that the tensile and compressive moduli obtained using these formulas were in well agreement with the values obtained from the direct tension and compression tests. The formulas deduced from the Brazilian test based on the assumption of isotropy overestimated the tensile strength and tensile modulus and underestimated the compressive modulus. This work provides a new methodology to estimate tensile strength and moduli of rock simultaneously considering tension-compression bi-modularity.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.307-314
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• 2013

Objectives: The aim of this study was to determine the prevalence of symptoms relating to musculoskeletal disorders (MSDs) and investigate the risk factors among researchers at university laboratories. Methods: 209 researchers were included in this study, drawn from 27 laboratories at three universities in Korea. Checklists for MSD symptoms and risk factor assessment were utilized. Results: The symptoms checklist showed reliable results with Cohen's Kappa 0.33-0.56, percent agreement 81.0-96.8%, and correlation coefficient 0.41-0.63. The overall prevalence of MSD symptoms was 68.9%, while the prevalence in specific parts of body were as follows: shoulders (47.6%), lower back (46.9%), neck (46.9%), knees (25.4%), wrists (20.1%), elbows (13.6%). The symptom prevalence among women was higher than among men (OR 2.67, 95% CI 1.37-5.18). Daily exposure time was observed to be a significant risk factor for developing MSD symptoms (OR 2.14-6.07). Conclusions: This study suggested that repetitive pipetting and static work posture are the most significant risk factors for MSD symptoms among laboratory researchers.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.130-134
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• 2016

The influence of Au/Ni-based contact formed on a lightly-doped (7.3×1017cm−3, Zn-doped) InGaAsP layer for electrical compensation of surface plasmon polariton (SPP) propagation under various rapid thermal annealing (RTA) conditions has been studied. The active control of SPP propagation is realized by electrically pumping the InGaAsP multiple quantum wells (MQWs) beneath the metal planar waveguide. The metal planar film acts as the electric contact layer and SPP waveguide, simultaneously. The RTA process can lower the metal-semiconductor electric contact resistance. Nevertheless, it inevitably increases the contact interface morphological roughness, which is detrimental to SPP propagation. Based on this dilemma, in this work we focus on studying the influence of RTA conditions on electrical control of SPPs. The experimental results indicate that there is obvious degradation of electrical pumping compensation for SPP propagation loss in the devices annealed at 400℃ compared to those with no annealing treatment. With increasing annealing duration time, more significant degradation of the active performance is observed even under sufficient current injection. When the annealing temperature is set at 400℃ and the duration time approaches 60s, the SPP propagation is nearly no longer supported as the waveguide surface morphology is severely changed. It seems that eutectic mixture stemming from the RTA process significantly increases the metal film roughness and interferes with the SPP signal propagation.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.276-283
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• 2023

Purpose: We aimed to determine the differences in the levels of serum thyroid hormone (free T4 [FT4]) and thyroid stimulating hormone [TSH]) as biomarkers for hepatitis B virus (HBV) infection status, with respect to age and sex. Methods: We retrospectively analyzed serum samples from 200 patients who underwent HBV testing from August 2022 to September 2022. Serum samples were collected from patients suspected of having HBV infection who visited this hospital. Thyroid hormone levels were measured, and patients were grouped according to age and sex. Results: Differences in TSH and FT4 levels in the serum of patients in the HBV-positive and -negative groups were not significant. Among the HBV-positive patients in the younger age group (<60 years), TSH and FT4 levels were 1.78 ± 0.09 µIU/mL (normal: 0.4-5.0 µIU/mL) and 1.24 ± 0.02 ng/mL (normal: 0.8-1.9 ng/mL), respectively, whereas among the HBV-positive patients in the older age group (≥60 years), TSH and FT4 levels were 2.22 ± 0.17 µIU/mL and 1.24 ± 0.07 ng/mL, respectively. Conclusions: The presence of HBV did not markedly affect serum thyroid hormone levels. Our findings shed light on the conflicting evidence on the association between thyroid hormone levels and HBV infection. We, Hyeokjun Yun and Bo Kyeung Jung are co-first authors which made substantial contribution equally to the conception and designed of this work. Jae Kyung Kim, In soo Rheem and Kap No Lee made significant contributions to the acquisition and analysis of the data.

• Nutritional Sciences
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• v.8 no.4
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• pp.242-249
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• 2005

It is well established that zinc plays an important role in bone metabolism and mineralization. The role of zinc in bone formation is well documented in animal models, but not much reported in cell models. In the present study, we evaluated zinc deficiency effects on osteoblastic cell proliferation, alkaline phosphatase activity and expression, and extracellular matrix bone nodule formation and bone-related gene expression in osteoblastic MC3T3-E1 cells. To deplete cellular zinc, chelexed-FBS and interpermeable zinc chelator TPEN were used. MC3T3-E1 cells were cultured in zinc concentration-dependent (0-15 ${\mu}M\;ZnCl_2$) and time-dependent (0-20 days) manners. MC3T3-E1 cell proliferation by MTT assay was increased as medium zinc level increased (p<0.05). Cellular Ca level and alkaline phosphatase activity were increased as medium zinc level increased (p<0.05). Alkaline phosphatase expression, a marker of commitment to the osteoblast lineage, measured by alkaline phosphatase staining was increased as medium zinc level increased. Extracellular calcium deposits measured by von Kossa staining for nodule formation also appeared higher in Zn+(15 ${\mu}M\;ZnCl_2$) than in Zn-(0 ${\mu}M\;ZnCl_2$). Bone formation marker genes, alkaline phosphatase and osteocalcin, were also expressed higher in Zn+ than in Zn-. The current work supports the beneficial effect of zinc on bone mineralization and bone-related gene expression. The results also promote further study as to the molecular mechanism of zinc deficiency for bone formation and thus facilitate to design preventive strategies for zinc-deficient bone diseases.

• Membrane and Water Treatment
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• v.8 no.3
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• pp.259-277
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• 2017

Adsorption is a widely used technique for the removal of dyes from wastewaters by variety of adsorbents. In this work, the main focus is on the potential assessment of anion exchange membrane for the removal of different dyes using batch system and investigation of experimental data by applying various kinetic and thermodynamic models. The removal of anionic dyes i.e., Eosin-B, Eriochrome Black-T and Congo Red by anion exchange membrane BII from aqueous solution was carried out and effect of various parameters such as contact time, membrane dosage, temperature and ionic strength on the percentage removal of anionic dyes was studied. The experimental data was assessed by kinetic models namely pseudo-first-order, pseudo-second-order, Elovich liquid film diffusion, Bangham and the modified Freundlich models equation have been used to analyze the experimental data. These results indicate that the adsorption of these anionic dyes on BII follows pseudo-second-order kinetics with maximum values of regression coefficient (0.992-0.998) for all the systems. The adsorption of dyes was more suitable to be controlled by a liquid film diffusion mechanism. The adsorptive removal of dye Eosin-B and Eriochrome Black-T were decreased with temperature and thermodynamic parameters such as free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$) and entropy (${\Delta}S^o$) for adsorption of dyes on membrane BII were calculated at 298 K, 308 K and 318 K. The values of enthalpy and entropy were negative for EB and EBT representing that the adsorption of these dyes on BII is physiosorptive and exothermic in nature. Whereas the positive values of enthalpy and entropy for CR adsorption on BII, indicating that its adsorption is endothermic and spontaneous in nature. It is evident from this study that anion exchange membrane has shown good potential for the removal of dyes from aqueous solution and it can be used as adsorbent for dues removal on commercial levels.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.105-111
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• 2015

In late December 2013, the Ebola virus emerged from West Africa. The outbreak started in Guinea and rapidly spread to Liberia and Sierra Leone. Initially, the virus is spread to the human population after contact with infected wildlife and then spread person-to-person through direct contact with body fluids such as blood, sweat, urine, semen, and breast milk. The Ebola virus infects endothelial cells, mononuclear phagocytes and hepatocytes. It causes massive damage to internal tissues and organs, such as blood vessels and the liver, and ultimately death. Most tests for the virus RNA rely on a technology called reverse-transcriptase polymerase chain reaction (RT-PCR). While this method is highly sensitive, it is also expensive, requiring skilled scientists, and delicate power supplies. The strip analytical technique (enzyme-linked immunosorbent assay or ELISA) detects antigens or antibodies to the Ebola virus. This test is cheap and does not require electricity or refrigeration. Despite ongoing efforts directed at experimental treatments and vaccine development, current medical work on the Ebola viral disease is largely limited to supportive therapy. Thus, rapid and reliable diagnoses of the Ebola virus are critically important for patient management, infections, prevention, and control measures.

• Industrial Engineering and Management Systems
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• v.11 no.2
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• pp.142-147
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• 2012

Individuals with autistic spectrum disorders (ASD) have difficulty inferring other people's feelings from their facial expressions and/or from situational cues, and therefore, they are less able to respond with prosocial behavior. We developed a computer-based training program to help teach the connection between facial-based or situation-based emotions and prosocial behavioral responses. An 8-year-old male school child with ASD participated in the study. In this program, he was trained to identify persons in need of help and appropriate prosocial responses using novel photo-based scenarios. When he misidentified emotions from photographs of another's face, the program highlighted those parts of the face which effectively communicate emotion. To increase the likelihood that he would learn a generalized repertoire of emotional understanding, multiple examples of emotional expressions and situations were provided. When he misidentified persons expressing a need for help, or failed to identify appropriate helping behaviors, role playing was used to help him appreciate the state of mind of a person in need of help. The results of the training indicated increases in prosocial behaviors during a laboratory task that required collaborative work. His homeroom teacher, using a behavioral rating scale, reported that he now understood another's emotion or situation better than before training. These findings indicate the effects of the training are not limited to the artificial experiment situation, but also carried over to his school life.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.427-436
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• 2021

The article reveals and theoretically substantiates the trends of foreign language teachers' professional training in universities of Ukraine in terms of European integration, which are systematized in three areas: macro-level (system of education), meso-level (universities) and micro-level (subjects of educational process). The article aims to substantiate the trends of foreign language teacher training in the context of European integration and the main directions of creative use of constructive ideas of European experience in the innovative development of education. The article lights up the system for improving foreign language teacher training in universities, which is based on updated goals, content and approaches to the implementation of basic concepts, principles and features of teacher training in European experience, enable us to improve the quality of teacher training, its competitiveness in the European labor market. In the article developed the conceptual model of strategic development of the university in the conditions of European integration. It is emphasized that information technologies provide great opportunities for the development of professional skills and intellectual potential of future professionals. At present, the computerization of the educational process in higher education institutions is considered as one of the first and most promising areas for improving the quality of education. The article offered directions of internationalization of educational activity of university in the conditions of European integration. Diagnostic tools for the development of the university in terms of integration into the European educational space, individual rating and ranking of structural units of the university have been developed; main directions of activity of the laboratory of the skill of the teacher of higher school and methodical recommendations on the creation and the organization of work of scientific laboratories.