• Korean Journal of Metals and Materials
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• v.49 no.2
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• pp.145-152
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• 2011

Mechanical and property corrosion resistance of Mg-Zn-Y alloys with an atomic ratio of Zn/Y of 6.8 are investigated using optical microscopy, scanning electron microscopy, transmission electron microscopy, uniaxial tensile test and corrosion test with immersion and dynamic potentiometric tests. The alloys showed an in-situ composite microstructure consisting of ${\alpha}$-Mg and icosahedral phase (I-phase) as a strengthening phase. As the volume fraction of the I-phase increases, the yield and tensile strengths of the alloys increase while maintaining large elongation (26~30%), indicating that I-phase is effective for strengthening and forms a stable interface with surrounding ${\alpha}$-Mg matrix. The presence of I-phase having higher corrosion potential than ${\alpha}$-Mg, decreased the corrosion rate of the cast alloy up to I-phase volume fraction of 3.7%. However further increase in the volume fraction of the I-phase deteriorates the corrosion resistance due to enhanced internal galvanic corrosion cell between ${\alpha}$-Mg and I-phase.

• Journal of Trauma and Injury
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• v.34 no.4
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• pp.257-262
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• 2021

Purpose: Pediatric hand trauma is common and sometimes causes deformity or disability. The incidence and etiologies of hand trauma in children are different from those in adults. This study analyzed the characteristics of pediatric hand trauma cases and patients over a 15-year period. Methods: We conducted a retrospective medical record review of 3,432 children (2,265 boys, 1,167 girls, under 18 years of age) with hand injuries from January 2005 to December 2019. We evaluated the sex distribution and injury etiologies. Injuries were classified by type as burns, amputations, crushing injuries, lacerations, extensor and flexor tendon injuries, open and closed fractures, and nerve injuries. Results: Among the pediatric hand injury patients, males were predominant (1.94:1). Simple lacerations (58.4%) were the most common injury type, followed by fractures (22.8%). Lacerations and burns tended to be common in younger age groups, while tendon injuries, nerve injuries, and crushing injuries were more frequently encountered in older age groups. Conclusions: Hand trauma prevention strategies should be established considering the frequent trauma etiologies in specific age groups. An awareness of age-specific characteristics of pediatric hand trauma patients will be helpful to prevent hand trauma.

• Journal of the Korean Mathematical Society
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• v.59 no.6
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• pp.1047-1065
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• 2022

For two dimensional lattices, a Gaussian basis achieves all two successive minima. For dimension larger than two, constructing a pairwise Gaussian basis is useful to compute short vectors of the lattice. For three dimensional lattices, Semaev showed that one can convert a pairwise Gaussian basis to a basis achieving all three successive minima by one simple reduction. A pairwise Gaussian basis can be obtained from a given basis by executing Gauss algorithm for each pair of basis vectors repeatedly until it returns a pairwise Gaussian basis. In this article, we prove a necessary and sufficient condition for a pairwise Gaussian basis to achieve the first k successive minima for three dimensional lattices for each k ∈ {1, 2, 3} by modifying Semaev's condition. Our condition directly checks whether a pairwise Gaussian basis contains the first k shortest independent vectors for three dimensional lattices. LLL is the most basic lattice basis reduction algorithm and we study how to use LLL to compute a pairwise Gaussian basis. For δ ≥ 0.9, we prove that LLL(δ) with an additional simple reduction turns any basis for a three dimensional lattice into a pairwise SV-reduced basis. By using this, we convert an LLL reduced basis to a pairwise Gaussian basis in a few simple reductions. Our result suggests that the LLL algorithm is quite effective to compute a basis with all three successive minima for three dimensional lattices.

• Analytical Science and Technology
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• v.35 no.2
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• pp.60-68
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• 2022

In this study, we developed and validated a sensitive analytical method to quantify baphicacanthin A in mouse plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The standard calibration curves for baphicacanthin A ranged from 0.5 to 200 ng/mL and were linear, with an r² of 0.985. The inter- and intra-day accuracy and precision and the stability fell within the acceptance criteria. Besides, we investigated the pharmacokinetics of baphicacanthin A following its intravenous (5 mg/kg) and oral administration (30 mg/kg). Intravenously injected baphicacanthin A showed biphasic elimination kinetics with high clearance and volume of distribution values. Furthermore, baphicacanthin A showed a rapid absorption but low aqueous solubility (182.51±0.20 mg/mL), resulting in low plasma concentrations and low oral bioavailability (2.49 %). Thus, we successfully documented the pharmacokinetic properties of baphicacanthin A using this newly developed sensitive LC-MS/MS quantification method, which could be used in future lead optimization and biopharmaceutic studies.

• Physical Therapy Korea
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• v.29 no.3
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• pp.235-240
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• 2022

Background: A spinal extension and intensive rehabilitation program reduced the symptoms and pain of kyphosis, and improved function. Objects: This study aimed to demonstrate the effect of a spine extension device on the degree of thoracic kyphosis and extension angles, confirm reduction of the kyphosis angle and an increase in flexibility. Methods: Thirteen adults were enrolled in the experiment, using the spine extension device, which was set to passively extend the spine. The angle between the spinous process of the first thoracic vertebra and the spinous process of the twelfth thoracic vertebra was measured by dual inclinometer before and after using the spine extension device. Results: In the static posture, the thoracic kyphosis decreased after using the spine extension device in the thoracic extension posture, and there was a significant difference (p < 0.05); thoracic extension angle increased with statistical significance (p < 0.05). Conclusion: In this study, the thoracic kyphosis angle and thoracic extension angle of the subjects before and after using spine extension device was compared and analyzed, which proved that the spine extension device can effectively improve the mobility of spinal extension.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.1
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• pp.95-103
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• 2023

Rosiglitazone is a thiazolidinedione-class antidiabetic drug that reduces blood glucose and glycated hemoglobin levels. We here investigated the interaction of rosiglitazone with Kv3.1 expressed in Chinese hamster ovary cells using the wholecell patch-clamp technique. Rosiglitazone rapidly and reversibly inhibited Kv3.1 currents in a concentration-dependent manner (IC₅₀ = 29.8 µM) and accelerated the decay of Kv3.1 currents without modifying the activation kinetics. The rosiglitazonemediated inhibition of Kv3.1 channels increased steeply in a sigmoidal pattern over the voltage range of -20 to +30 mV, whereas it was voltage-independent in the voltage range above +30 mV, where the channels were fully activated. The deactivation of Kv3.1 current, measured along with tail currents, was also slowed by the drug. In addition, the steady-state inactivation curve of Kv3.1 by rosiglitazone shifts to a negative potential without significant change in the slope value. All the results with the use dependence of the rosiglitazone-mediated blockade suggest that rosiglitazone acts on Kv3.1 channels as an open channel blocker.

• Journal of East-West Nursing Research
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• v.15 no.1
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• pp.54-62
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• 2009

Purpose: The purpose of this study was to examine the effects of relaxation therapy to reduce anxiety level among spinal anesthesia surgery patients. Methods: The study employed a quasi-experimental pre-and-posttest design with nonequivalent control group. The experimental group was provided with the 15-min muscle relaxation therapy on the day before the surgery and an hour before the spinal anesthesia. Data were collected from 44 patients (22 in experimental and 22 in control group) who were planned to have spinal anesthesia surgery from an orthopedic surgery department at a general hospital in Seoul from January 13 to March 21, 2006. Results: The experimental group reported lower level of state anxiety after the surgery (23.18 vs. 33.64) than did control group but was not statistically significant. There were no significant differences in blood pressure or pulse rate between experimental and control groups after surgery. Conclusions: The further research should be conducted to polish the muscle relaxation therapy for various types of patients and to create more comfortable environment setting for application of the therapy. The muscle relaxation therapy may be a convenient and useful nursing intervention to reduce anxiety among spinal anesthesia surgery patients if more studies prove its effectiveness.

• Childhood Kidney Diseases
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• v.27 no.1
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• pp.40-45
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• 2023

Tubulointerstitial nephritis and uveitis (TINU) syndrome is defined as the occurrence of tubulointerstitial nephritis and uveitis in the absence of other systemic diseases. Three pediatric cases have been reported in the Republic of Korea, and we now report a fourth case. A 15-year-old girl presented to the ophthalmology department with a 1-week history of bilateral ocular discomfort that worsened on the day of presentation with redness and pain in both eyes. She was diagnosed with bilateral uveitis, and her baseline examination revealed moderate renal dysfunction and mild proteinuria. A renal biopsy was performed and confirmed the diagnosis of TINU syndrome. She was started on steroid eye drops and a 12-week course of oral steroids at a dose of 40 mg/m²/day, which completely resolved the proteinuria and mild renal function to an estimated glomerular filtration rate of 60 mL/min/1.73 m². However, the uveitis did not improve, and despite the addition of oral methotrexate as a second-line treatment, the uveitis remains unresponsive to treatment over 21 months. Further evaluation and treatment are ongoing, and active therapeutic intervention is suggested even at a pediatric age, considering the lack of improvement in renal function and uveitis to date.

• Journal of the Korean Society of Food Culture
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• v.22 no.6
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• pp.673-681
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• 2007

A technological trend of treating or preventing the cardiovascular diseases has reviewed on 381 domestic and foreign patents from the year 1980 to June, 2007. Primarily focused upon countries such as Korea, Japan and the United States; the leading nations concerning cardiovascular disease, this paper delved into a systematic research of the cardiovascular disease utilizing research focused database and research analysts. Korea was showing increased development in the diet and cardiovascular related areas as shown by increase in related patent caseloads and submission since the 2000. Especially within the area of food production, there had been an increase of market share by up to 50% and the frequency of patent submission had also increased. Japan was showing similar trend as Korea with its increase in research, but the only difference was that Japan was focused more upon medical supplies. With the United States, there was no real consistency with the number of patents, therefore harder to make an accurate assessment.

• Korea Trade Review
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• v.46 no.5
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• pp.153-171
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• 2021

The purpose of this study is to compare and derive the importance of motivating factors for start-up when deciding to start a business in the logistics and trading industries, and to compare, derive, and identify which motivating factors have an important influence on the start-up decision. In this study, 4 high-level factors such as career factors, policy/institutional factors, environmental factors, and economic factors and 12 low-level factors were derived from those four factors. Based on this, a questionnaire was distributed to established and prospective entrepreneurs, and the results were analyzed using the AHP (Analytic Hierarchy Process) technique. Manufacturing companies recognized the individual's capabilities and government support for them as important. Beside, service companies recognized the industrial environment that could generate economic benefits as important. Although there are differences in perception by group, it can be seen that factors that are recognized as important within each group have connectivity and show the same directivity.