• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.765-779
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• 2003

Physiological lipid mixtures comprised of cholesterol, ceramide and free fatty acid better maintain epidermal homeostasis and have been recently used for dermatoses induced by skin barrier damage, for example for atopic dermatitis and xerotic skin. Itching and dry atopic dermatitis of the skin may be related to altered skin barrier function. In a previous study, the use of multi-lamellar emulsion (MLE), which is a lipid mixtures containing cholesterol, pseudoceramide and free fatty acid, has been shown to accelerate the recovery of the epidermal permeability barrier. In this study, we assessed the efficacy of MLE compared with a currently used anti-itch moisturizer (AIM), the active ingredients of which are menthol and camphor, on barrier recovery after barrier disruption. To clarify the effect of MLE and AIM after acute barrier perturbation, we measured the relation between transepidermal water loss (TEWL) and the barrier recovery rate at 3, 6, 24, and 48 hours after tape stripping hairless mice and then observed changes in the stratum corneum (SC), including the intercellular lipid structure and secretion of lamellar bodies, by electron microscopy. MLE treated skin recover skin barrier function more rapidly, and AIM treated skin delayed barrier repair. Morphological changes in the epidermis, of MLE treated skin revealed well-conserved lipid multi-lamellar structures at 24 h after tape stripping, whereas AIM treated skin showed altered lamellar bilayers within the SC interstices at 48 h. In addition, MLE treated skin showed an increase in the number of LBs and in their secretions and a decrease in the number of SC layers versus AIM treated skin. These results suggest that MLE may accelerate the production of an epidermal permeability barrier in hairless mice by increasing the number and secretion of LB and improve the dryness and itch associated with an altered epidermal permeability barrier.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.321-326
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• 2012

Recent studies have revealed that collagen peptide plays a protective role on skin by improving the activity of antioxidants and acts as an inducer of skin regeneration. To evaluate the efficacy of low molecular weight collagen peptide for skin recovery after non-ablative 1550 nm fractional photothermolysis laser. 10 volunteers were randomly divided into two groups. Both control and experimental groups received fractional photothermolysis treatment. In the experimental group, 5 subjects received oral collagen peptide 1,000 mg/day for 8 weeks. Before and after the treatment, we measured elastic recovery of skin, transepidermal water loss (TEWL) and erythema index (EI) for each patients. The evaluation of clinical results showed that elastic recovery of skin is higher in the experimental group than the control group (p < 0.05). TEWL have no significancy between two groups and erythema rapidly disappeared in the experimental group. On the quartile grading scale, the mean patient satisfaction 4 weeks after the fractional photothermolysis treatment was 2.0 in experimental group and 1.2 in control group. The low molecular weight collagen peptide appears to be an effective conservative therapy for skin recovery after non-ablative 1550 nm fractional photothermolysis treatment.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.345-352
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• 2014

In this paper, the CAD data for the optimal shape design obtained by isogeometric shape optimization is directly used to fabricate the specimen by using 3D printer for the experimental validation. In a conventional finite element method, the geometric approximation inherent in the mesh leads to the accuracy issue in response analysis and design sensitivity analysis. Furthermore, in the finite element based shape optimization, subsequent communication with CAD description is required in the design optimization process, which results in the loss of optimal design information during the communication. Isogeometric analysis method employs the same NURBS basis functions and control points used in CAD systems, which enables to use exact geometrical properties like normal vector and curvature information in the response analysis and design sensitivity analysis procedure. Also, it vastly simplify the design modification of complex geometries without communicating with the CAD description of geometry during design optimization process. Therefore, the information of optimal design and material volume is exactly reflected to fabricate the specimen for experimental validation. Through the design optimization examples of elasticity problem, it is experimentally shown that the optimal design has higher stiffness than the initial design. Also, the experimental results match very well with the numerical results. Using a non-contact optical 3D deformation measuring system for strain distribution, it is shown that the stress concentration is significantly alleviated in the optimal design compared with the initial design.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.35-41
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• 2013

Properties of $NaBH_4$ hydrolysis reaction using Co-P-B/FeCrAlloy catalyst and the catalyst durability were studied. Co-P-B/FeCrAlloy catalyst showed low activation energy such as 25.2 kJ/mol in 5 wt% $NaBH_4$ solution, which was similar that of noble metal catalyst. The activation energy increased as the $NaBH_4$ concentration increased. Formation of gel at high concentration of $NaBH_4$ seriously affected hydrogen evolution rate and the catalyst durability. The catalyst loss decreased as reaction temperature increased due to lower gel formation when the concentration of $NaBH_4$ was over 20 wt%. Considering hydrogen generation rate and durability of catalyst, the catalyst supported with FeCrAlloy heat-treated at $1,000^{\circ}C$ without ultra vibration during dipping and calcination after catalyst dipping was best catalyst. To use catalyst more than three times in 25 wt% $NaBH_4$ solution, it should be reacted at higher temperature than $60^{\circ}C$.

• KIEAE Journal
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• v.17 no.1
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• pp.69-75
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• 2017

Purpose: Heat transfer analysis of recently developed 'slim type double-skin system window' were presented. This window system is designed for curtain wall type façade that main energy loss factor of recent elegant buildings. And the double skin system is the dual window system integrated with inner shading component, enclosed gap space made by two windows when both windows were closed and shading component effectively reflect and terminate solar radiation from outdoor. Usually double-skin system requires much more space than normal window systems but this development has limited by 270mm, facilitated for curtain wall façade buildings. In this study, we estimated thermophysical phenomena of our double-skin curtain wall system window with solar load conditions at the summer season. Method: A fully 3-Dimentional analysis adopted for flow and convective and radiative heat transfer. The commercial CFD package were used to model the surface to surface radiation for opaque solid region of windows' frame, transparent glass, fluid region at inside of double-skin and indoor/outdoor environments. Result: Steep angle of solar incident occur at solar summer conditions. And this steep solar ray cause direct heat absorption from outside of frame surface rather than transmitted through the glass. Moreover, reflection effect of shading unit inside at the double-skin window system was nearly disappeared because of solar incident angle. With this circumstances, double-skin window system effectively cuts the heat transfer from outdoor to indoor due to separation of air space between outdoor and indoor with inner space of double-skin window system.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.443-455
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• 2013

Electrochemical studies on charge transfer reactions across the interface between two immiscible electrolyte solutions (ITIES) have greatly attracted researcher's attentions due to their wide applicability in research fields such as ion sensing and biosensing, modeling of biomembranes, pharmacokinetics, phase-transfer catalysis, fuel generation and solar energy conversion. In particular, there have been extensive efforts made on developing sensing platforms for ionic species and biomolecules via gelifying one of the liquid phases to improve mechanical stability in addition to creating microscale interfaces to reduce ohmic loss. In this review, we will mainly discuss on the basic principles, applications and future aspects of various sensing platforms utilizing ion transfer reactions across the ITIES. The ITIES is classified into four types : (i) a conventional liquid/liquid interface, (ii) a micropipette supported liquid/liquid interface, (iii) a single microhole or an array of microholes supported liquid/ liquid interface on a thin polymer film, and (iv) a microhole array liquid/liquid interface on a silicon membrane. Research efforts on developing ion selective sensors for water pollutants as well as biomolecule sensors will be highlighted based on the use of direct and assisted ion transfer reactions across these different ITIES configurations.

• Clinics in Shoulder and Elbow
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• v.6 no.1
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• pp.55-66
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• 2003

Background: The purpose of this study was to evaluated results of arthroscopic treatment of the traumatic recurrent unidirectional posterior subluxation. Materials and Methods: We treated twenty-seven patients who had traumatic recurrent unidirectional posterior subluxation of the shoulder by arthroscopic labral repair and posterior capsular shift and prospectively evaluated for a mean of thirty-nine months (range,24 to 85 months). Patients who had posteroinferior instability, multidirectional instability, atraumatic onset, or revision cases were excluded. There were twenty-five male and two female patients with the mean age of twenty-one years (range, 14 to 33 years). All patients were involved in sports activity. All had a significant traumatic event prior to the onset of the instability. Stability, motion, three objective measurement (UCLA, ASES, and Rowe scores) and two subjective measurements (pain and function visual analogue scale) were evaluated. Results: The most common finding in magnetic resonance image-arthrogram was separation of the posteroinferior labrum without displacement in 9 patients, In arthroscopic examination, all patients had one or more lesions in the posterior inferior labrum and capsule. The most common finding was incomplete stripping of the posterior inferior labrum (18 patients). The posteroinferior capsule subjectively appeared to be stretched in twenty-two patients. At follow-up, all patients had improved shoulder function and scores(p < 0.01). All patients had stable shoulder by subjectivel and objectivel measurements, except one patient who had recurrent subluxation. All but one patient with postoperative recurrence were able to return to their prior sports activity with little or no limitation. Twenty-four patients were graded as having more than 90％ of shoulder function. Their were twenty-one excellent, five good, and one fair UCLA. scores. Pain sore improved from 4.5 to 0.2 point(p : 0.0001). Mean loss internal rotation was one vertebral level. None had operative complications. Conclusion: In conclusion, treatment outcomes of the traumatic unidirectional recurrent posterior subluxation are consistently reliable with respect to the stability, pain relief, and functional restoration by the arthroscopic posterior capsular shift procedure.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.4
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• pp.381-391
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• 2010

In this paper, a novel frequency reconfigurable active array antenna(RAA) system, which can be reconfigurable for three reconfigurable frequency bands, is proposed by using commercial RF MEMS switches. The MEMS switch shows excellent insertion loss, linearity, as well as isolation. So, the system performance degradation of the reconfigurable system by using MEMS switches can be minimized. The proposed frequency reconfigurable active antenna system is consisted with the noble frequency reconfigurable front-end amplifiers(RFA) with the simple reconfigurable impedance matching circuits(RMC), reconfigurable antenna elements(RAE), as well as a reconfiguration control board(RCB) for MEMS switch control. The proposed RAA system can be reconfigurable for three frequency bands, 850 MHz, 1.9 GHz, and 3.4 GHz, with $2{\times}2$ array of the RAE having broadband printed dipole antenna topology. The validity of the proposed RFA as well as RAA is also presented with the experimental results of the fabricated systems.

• Journal of Radiation Protection and Research
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• v.36 no.2
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• pp.79-85
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• 2011

OThe purpose of this article was to measure and compare the value of the metal artifact reduction (MAR) algorithm by Dual energy(kVp switching) CT (Computed Tomography) for non using MAR and we introduced new variable Dual energy CT applications through a clinical scan. The used equipment was GE Discovery 750HD with Dual-Energy system(kVp switching). CT scan was performed on the neck and abdomen area subject for patients. Studies were from Dec 20 2010 to Feb 10 2011 and included 25 subject patients with prosthesis. We were measured the HU (Hounsfield Unit) and noise value at metal artifact appear(focal loss of signal and white streak artifact area) according to the using MAR algorithm. Statistical analyses were performed using the paired sample t-test. In patient subject case, the statistical difference of showing HU was p=0.01 and p=0.04 respectively. At maximum black hole artifact area and white streak artifact area according to the using MAR algorithm. However noise was p=0.05 and p=0.04 respectively; and not the affected black hole and white streak artifact area. Dual Energy CT with the MAR algorithm technique is useful reduce metal artifacts and could improve the diagnostic value in the diagnostic image evaluation of metallic implants area.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.9005-9008
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• 2014

Background: Gastric cancer is the second leading course of cancer death worldwide and H. pylori infection is an important risk factor for gastric cancer development. This study was design to evaluate the clinical, pathological features, survival rate and prevalence of H. pylori infection in gastric cancer in Thailand. Materials and Methods: Clinical information, histological features, endoscopic findings and H. pylori status were collected from gastric cancer patients from Thammasat university hospital during June 1996-December 2011. H. pylori infection was assessed by histological evaluation, rapid urease test and serological test. Clinical information, endoscopic findings and histopathology of all patients were recorded and compared between patients with active or non-active H. pylori infection. Results: A total of 100 gastric cancer patients (55 men and 45 women with mean age of $55{\pm}16.8years$) were enrolled in this study. Common presenting symptoms were dyspepsia (74%), weight loss (66%), anemia (63%) and anorexia (38%). Mean duration of symptoms prior to diagnosis was 98 days. Overall prevalence of H. pylori infection was 83% and active H. pylori infection was 40%. 1-year and 5-year survival rates were 43% and 0%. There was no significant difference between active H. pylori infection in different locations (proximal vs non-proximal: 47.1% vs 48.5%; P-value = 0.9, OR=0.9; 95%CI=0.3-3.1) and histology of gastric cancer (diffuse type vs intestinal type: 47.4% vs 50%; P-value = 0.8, OR=0.9, 95%CI=0.3-2.7). However, linitis plastica was significantly more common in non-active than active H. pylori infection (27.9% vs 0%; P-value<0.0001, OR=13.3, 95%CI=3.2-64.5). Moreover, gastric cancer stage 4 was higher in non-active than active H. pylori infection (93% vs 50%, P-value<0.001). Conclusions: Prevalence of H. pylori infection in Thai gastric cancer patients was high but active infection was low. Most gastric cancer patients presented in advance stage and had a grave prognosis. Screening for gastric cancer in high risk individuals might be an appropriate tool for early detection and improve the treatment outcome for this particular disease in Thailand.