• Advances in concrete construction
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• v.14 no.5
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• pp.317-330
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• 2022

This paper investigated computationally and experimentally the interaction here between a notch as well as a micropore under uniaxial compression. Brazilian tensile strength, uniaxial tensile strength, as well as biaxial tensile strength are used to calibrate PFC2d at first. Then, uniaxial compression test was conducted which they included internal notch and micro pore. Experimental and numerical building of 9 models including notch and micro pore were conducted. Model dimensions of models are 10 cm × 10 cm × 5 cm. Joint length was 2 cm. Joints angles were 30°, 45° and 60°. The position of micro pore for all joint angles was 2cm upper than top of the joint, 2 cm upper than middle of joint and 2 cm upper than the joint lower tip, discreetly. The numerical model's dimensions were 5.4 cm × 10.8 cm. The fractures were 2 cm in length and had angularities of 30, 45, and 60 degrees. The pore had a diameter of 1 cm and was located at the top of the notch, 2 cm above the top, 2 cm above the middle, and 2 cm above the bottom tip of the joint. The uniaxial compression strength of the model material was 10 MPa. The local damping ratio was 0.7. At 0.016 mm per second, it loaded. The results show that failure pattern affects uniaxial compressive strength whereas notch orientation and pore condition impact failure pattern. From the notch tips, a two-wing fracture spreads almost parallel to the usual load until it unites with the sample edge. Additionally, two wing fractures start at the hole. Both of these cracks join the sample edge and one of them joins the notch. The number of wing cracks increased as the joint angle rose. There aren't many AE effects in the early phases of loading, but they quickly build up until the applied stress reaches its maximum. Each stress decrease was also followed by several AE effects. By raising the joint angularities from 30° to 60°, uniaxial strength was reduced. The failure strengths in both the numerical simulation and the actual test are quite similar.

• IMMUNE NETWORK
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• v.22 no.1
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• pp.8.1-8.20
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• 2022

Rheumatoid arthritis (RA) is a representative autoimmune disease that is primarily characterized by persistent inflammation and progressive destruction of synovial joints. RA has a complex and heterogeneous pathophysiology, involving interactions among various immune and joint stromal cells and a diverse network of cytokines and intracellular signaling pathways. With improved understanding of RA, over the past decades, therapeutic strategies have become considerably advanced and now included targeted molecular therapies, such as tumor necrosis factor inhibitors, IL-6 blockers, B-cell depletion agents, as well as inhibitors of T-cell co-stimulation and Janus kinases. However, a considerable proportion of RA patients experience refractory disease and interrupted treatment owing to the associated risk of developing serious infections and cancers. In contrast, although IL-1β, IL-17A, and p38α play significant roles in RA pathogenesis, several drugs targeting these factors have not been approved because of their low efficacy and severe adverse effects. In this review, we provide an overview of the working mechanism, advantages, and limitations of the currently available targeted drugs for RA. Additionally, we suggest potential mechanistic causes for clinically approved and failed drugs. Thus, this review provides perspectives on approaches for basic and translational studies that hold promise for identifying future next-generation therapeutics for RA.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.163-168
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• 2007

Background: Temporomandibular joint disorder (TMD) is a group of musculoskeletal conditions characterized by pain in the pre-auricular area, limitation of jaw movement and palpable muscle tenderness. Thermography is a nonionizing, noninvasive diagnostic alternative for the evaluation of TMD. This study was conducted to evaluate the usefulness of thermography in the assessment of TMD. Methods: Thermography was conducted on the 61 patients who had been diagnosed with TMD, and on the 34 normal symptom-free volunteers. The temperature differences between opposite sides of the temporomandibular joint (${\Delta}T_{TMJ}$) and the masseter muscle (${\Delta}T_{MST}$) were calculated. The sensitivity and specificity of thermography was calculated at the cut off values of 0.2, 0.3, and $0.4^{\circ}C$. Results: In the patient group, the ${\Delta}T_{TMJ}$ was $0.42{\pm}0.38^{\circ}C$ and the ${\Delta}T_{MST}$ was $0.38{\pm}0.33^{\circ}C$, whereas in the control group the ${\Delta}T_{TMJ}$ was $0.10{\pm}0.07^{\circ}C$ and the ${\Delta}T_{MST}\;0.15{\pm}0.10^{\circ}C$. In addition, the patient group demonstrated a significantly lower level of thermal symmetry than the control group (P < 0.001) in both the temporomandibular joints and the masseter muscles. The sensitivity of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 67.2, 49.2, and 42.6% in the temporomandibular joint (TMJ) and 60.7, 49.2 and 37.7% in the masseter muscle, respectively. The specificity of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 88.2, 100, and 100% in the TMJ and 61.8, 91.2 and 100% in the masseter muscles, respectively. The accuracy of thermography at the cut off values of 0.2, 0.3 and $0.4^{\circ}C$ was 74.7, 67.4, and 63.2% in TMJ and 61.1, 64.2 and 60.0% in the masseter muscles, respectively. Conclusions: Temperature differences exist between the opposite sides of the TMD and masseter muscles in patients with TMD. Although the sensitivity of thermography in the diagnosis of TMD is low, it has high specificity in the evaluation of TMD, and is therefore applicable to patients with TMD.

• Korean Journal of Materials Research
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• v.3 no.1
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• pp.33-42
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• 1993

Abstract The increasing application of $Al_2$,$O_3$ and related ceramics as engineering materials is because of their attractive properties of fine ceramics. One solution to the wide variety of ceramic to metal combination lies in the effective joining. Active metal brazing of $Al_2$,$O_3$, to STS304 was investigated using Cu -Ti alloys. Titanium additive is chosen since it is good oxide former~. Brazing is performed under vacuum($10^{-3}$-$10^{-4}$ torr), a temperature between 1100 and 120$0^{\circ}C$ and time of 0.5-1.5hr. The microstructure of the brazed joints of $Al_2$,$O_3$ to STS304 with Cu-Ti insert metals were examined by using optical microscope and SEM and reaction products were analyzed by using EDX, WDX and XRD. Also interfacial reactions occuring during the brazing of $Al_2$,$O_3$/Cu-Ti/STS304 system are discussed. Experimental results showed formation of Titanium oxide T$i_2$$O_3$ which is attributable to the joining $Al_2$,$O_3$ to STS304 with Cu-Ti insert metal.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.3 s.32
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• pp.37-45
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• 2004

Electroless Ni(P) has been widely used for under bump metallization (UBM) of flip chip and surface finish layer in microelectronic packaging because of its excellent solderability, corrosion resistance, uniformity, selective deposition without photo-lithography, and also good diffusion barrier. However, the brittle fracture at solder joints and the spatting of intermetallic compound (IMC) associated with electroless Ni(P) are critical issues for its successful applications. In the present study, the mechanism of IMC spatting and microstructure change of the Ni(P) film were investigated with varying P content in the Ni(P) film (4.6,9, and $13 wt.\%$P). A reaction between Sn penetrated through the channels among $Ni_3Sn_4$ IMCs and the P-rich layer ($Ni_3P$) of the Ni(P) film formed a $Ni_3SnP$ layer. Thickening of the $Ni_3SnP$ layer led to $Ni_3Sn_4$ spatting. After $Ni_3Sn_4$ spatting, the Ni(P) film directly contacted the molten solder and the $Ni_3P$ phase further transformed into a $Ni_2P$ phase. During the crystallization process, some cracks formed in the Ni(P) film to release tensile stress accumulated from volume shrinkage of the film.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.479-483
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• 2009

Objective : A mouse model of spinal cord injury (SCI) could further increase our basic understanding of the mechanisms involved in injury and repair of the nervous system. The purpose of this study was to investigate whether methods used to produce and evaluate photochemical graded ischemic SCI in rats, could be successfully adapted to mice, in a reliable and reproducible manner. Methods : Thirty female imprinting control region mice (weighting 25-30 g, 8 weeks of age) were used in this study. Following intraperitoneal injection of Rose bengal, the translucent dorsal surface of the T8-T9 vertebral laminae of the mice were illuminated with a fiber optic bundle of a cold light source. The mice were divided into three groups; Group 1 (20 mg/kg Rose bengal, 5 minutes illumination), Group 2 (20 mg/kg Rose bengal, 10 minutes illumination), and Group 3 (40 mg/kg Rose bengal, 10 minutes illumination). The locomotor function, according to the Basso-Beattie-Bresnahan scale, was assessed at three days after the injury and then once per week for four weeks. The animals were sacrificed at 28 days after the injury, and the histopathology of the lesions was assessed. Results : The mice in group 1 had no hindlimb movement until seven days after the injury. Most mice had later recovery with movement in more than two joints at 28 days after injury. There was limited recovery of one joint, with only slight movement, for the mice in groups 2 and 3. The histopathology showed that the mice in group 1 had a cystic cavity involving the dorsal and partial involvement of the dorsolateral funiculi. A larger cavity, involving the dorsal, dorsolateral funiculi and the gray matter of the dorsal and ventral horns was found in group 2. In group 3, most of the spinal cord was destroyed and only a thin rim of tissue remained. Conclusion : The results of this study show that the photochemical graded ischemic SCI model. described in rats, can be successfully adapted to mice, in a reliable and reproducible manner. The functional deficits are correlated an increase in the irradiation time and, therefore, to the severity of the injury. The photothrombotic model of SCI, in mice with 20 mg/kg Rose bengal for 5 minutes illumination, provides an effective model that could be used in future research. This photochemical model can be used for investigating secondary responses associated with traumatic SCI.

• Korean Journal of Materials Research
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• v.9 no.7
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• pp.747-752
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• 1999

The interfacial reaction and joint properties of Sn-3.5Ag/Cu and Sn-3.5Ag-1Zn/Cu joint were studied. Modified double lap shear solder joints of Sn-3.5Ag and Sn-3.5Ag- lZn solder were aged for 60days at $100^{\circ}C$ and $150^{\circ}C$ and then loaded to failure in shear. The Sn-3.5Ag/Cu had a fast growth rate of the reaction layer in comparison with the Sn-3.5Ag-lZn at the aging temperature of $150^{\circ}C$ Through the SEM/EDS analysis of solder joint, it was proved that intermatallic layer was $Cu_{6}Sn_5$ phase and aged specimens showed that intermatallic layer grew in proportion to $t_{1/2}$, and the precipitate of $Ag_3Sn$ occur to both inner layer and interface of layer and solder. In case of Zn-containing composite solder, $Cu_{6}Sn_{5}$ phase formed at the side of substrate and $Cu_{5}Zn_{8}$ phase formed at the other side in double layer. The shear strength of the Sn-3.5Ag/Cu joint improved by addition of IZn. The strength of the joint increases with strain rate and decreases with aging temperature

• The Journal of Engineering Geology
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• v.22 no.4
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• pp.459-466
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• 2012

A difficulty encountered in engineering seismic mapping is that reflection events from shallow discontinuities are commonly overlapped with coherent noise such as air wave, direct waves, head waves, and high-amplitude surface waves. Here, the radial trace transform, a simple geometric re-mapping of a trace gather (x-t domain) to another trace gather (v-t domain), is applied to investigate the rejection effect of coherent linear noises. Two different types of data sets were selected as a representative database: good-quality data for intermediate sounding (hundreds of meters) in a sedimentary basin and very noisy data for shallow (${\leq}50m$) mapping of the weathered zone and bedrock surface. Results obtained with cascaded application of the radial transform and low-cut filtering proved to be as good as, or better than, those produced using f-k filtering, and were especially effective for air wave and direct wave. This simple transform enables better understanding of the characteristics of various types of noise in the RT domain, and can be generally applied to overcoming diffractions and back-scatterings caused by joints, fractures, and faults commonly that are encountered in geotechnical problems.

• Journal of muscle and joint health
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• v.12 no.2
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• pp.155-165
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• 2005

Arthritis is one of the most common chronic degenerative joint disease in elderly. Osteoarthritis is a widespread, slowly developing disease, with a high prevalence increasing with age in women. The large joints mostly involved by the disease are the knees. But there are no treatments available that cure the underlying process of osteoarthritis diseases. Physical exercise helps in increasing cartilage nutrition and remodeling, increases the synovial blood flow, decrease swelling, and improves muscle strength. Thus, exercise has been suggested as an important nursing strategy in osteoarthritis. Purpose: The purpose of this study were to compare muscle strength between Tai-Chi exercise and aquatic exercise for women with knee osteoarthritis. Methods: A quasi-experimental study with pretest and posttest measures was used. The study subjects were those who had been enrolled in a community health center, and agreed to participate in the study for eight weeks, signed the consent form, and obtained the physicians approval. The study dropout rates were 13.2% with the final study subjects of 17 on Tai-Chi exercise, 16 on aquatic exercise program. The collected data were analyzed using SPSS for Window (version 12.0). Independent sample t-test and paired t-test was performed to compare of muscle strength for women with osteoarthritis after 8-week Tai-Chi exercise and aquatic Exercise. Results: The homogeneity tests of demographic characteristics and study variables at the pretest data revealed no significant differences between two groups. After 8-week Tai-Chi and aquatic exercise, there was significant result in pre-post test comparison on muscle strength on Tai-Chi group, but no significant in aquatic group. There were no significant differences of knee extensor (p=.078), and hand grip(p=.118) in group comparisons on muscle strengths. But there were significant differences of knee flexor(p=.024). Conclusion: Tai-chi exercise was effective in improving knee flexor. So, it seems that Tai-chi exercise may be more suitable for aquatic exercise in osteoarthritis exercise programs. Further studies with other comparisons in physical and psycho social outcomes are necessary to confirm the more effects of exercise.

• Journal of Korean Physical Therapy Science
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• v.29 no.2
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• pp.28-37
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• 2022

Background: The purpose of this study was to investigate the effects of differences in the tension of Kinesio tape applied to the tibialis anterior muscle on muscle strength, joint range of motion and balance of ankle joint in young adults. Design: Randomized Controlled Trial. Methods: 41 young college students participated in this study. And the subjects were allocated randomly to two group. The experimental group had a tension difference (10%G, n=20). And there was no difference in tension in the control group (0%G, n=21). Jtech power track II, goniometer, and Biorescue were used to measure muscle strength, joint range of motion and balance. The paired t-test was performed to examine the differences within the groups before and after taping, and the independent t-test was performed to examine the differences between the groups. Result: 1) As a result of measuring muscle strength of each group, all measurements except 0%G of plantar flexion showed insignificant results. 2) Measurement of joint range of motion each group showed that neither 0%G nor 10%G was significant. 3) As a result of measuring the baladncing ability of each group there was a significant decrease in length, and average speed of the balancing capability (p<.05). 4) Comparisons between groups showed significant differences in the area among balance capability (p<.05). Conclusions: Based on these findings, the tension difference of Kinesio tape applied to the tibialis anterior muscle shows little effect on the muscle strength, range of motion, and balance of ankle joints. Given the current lack of research on the tension of kinesio tapes many studies are needed in the future to establish clear theories.