Characterization of a Translucent Material Produced from Paulownia tomentosa Using Peracetic Acid Delignification and Resin Infiltration.

Paulownia tomentosa, a tree species that allows for efficient production of translucent wood, was selected as an experimental wood species in this study, and a two-step process of delignification and polymer impregnation was performed. For delignification, 2-4 mm thick specimens were immersed in peracetic acid for 8 h. The delignified-wood specimens were impregnated using epoxy, a commercial transparent polymer. To identify the characteristics of the resulting translucent wood, the transmittance and haze of each type of wood section (cross- and tangential) were measured, while bending strength was measured using a universal testing machine. The translucent wood varied in properties according to the wood section, and the total transmittance and haze were 88.0% and 78.5% for the tangential section and 91.3% and 96.2% for the cross-section, respectively. For the bending strength, untreated wood showed values of approximately 4613.5 MPa modulus of elasticity (MOE), while the epoxy impregnation to improve the strength of the wood had increased the MOE up to approximately 6089.9 MPa, respectively. A comparative analysis was performed in this study with respect to the substitution of balsa, which is used widely in the production of translucent wood. The results are anticipated to serve as baseline data for the functionalization of translucent wood.

Cell proliferation effect of deep-penetrating microcavity tandem NIR OLEDs with therapeutic trend analysis.

Long wavelengths that can deeply penetrate into human skin are required to maximize therapeutic effects. Hence, various studies on near-infrared organic light-emitting diodes (NIR OLEDs) have been conducted, and they have been applied in numerous fields. This paper presents a microcavity tandem NIR OLED with narrow full-width half-maximum (FWHM) (34 nm), high radiant emittance (> 5 mW/cm2) and external quantum efficiency (EQE) (19.17%). Only a few papers have reported on biomedical applications using the entire wavelength range of the visible and NIR regions. In particular, no biomedical application studies have been reported in the full wavelength region using OLEDs. Therefore, it is worth researching the therapeutic effects of using OLED, a next-generation light source, and analyzing trends for cell proliferation effects. Cell proliferation effects were observed in certain wavelength regions when B, G, R, and NIR OLEDs were used to irradiate human fibroblasts. The results of an in-vitro experiment indicated that the overall tendency of wavelengths is similar to that of the cytochrome c oxidase absorption spectrum of human fibroblasts. This is the first paper to report trends in the cell proliferation effects in all wavelength regions using OLEDs.

A Clinical and Biochemical Evaluation of a Temperature-Controlled Continuous Non-Invasive Radiofrequency Device for the Treatment of Melasma.

BACKGROUND: Melasma shows characteristic histological features of photoaged skin. OBJECTIVE: We evaluated the effect of dermal rejuvenation using a temperature-controlled continuous non-invasive radiofrequency (RF) device on melasma. METHODS: Continuous skin heating at the temperature of 43°C for 20 minutes was performed in ten subjects with melasma who underwent 3 tri-weekly RF sessions. Pigmentation was evaluated with Mexameter® and investigator's global assessment (IGA). Immunohistochemical staining and image analysis was performed to evaluate biopsies from melasma skin before and after the treatment. RESULTS: The lesional melanin index was decreased by 13.7% at week 9. IGA score was improved from 3.50 at baseline to 2.95 at week 9. No significant adverse event was reported. Histologic analysis revealed reduced melanin and increased collagen density and thickness. The expression of procollagen-1 and type IV collagen was increased after the treatment. The number of p16INK4A-positive senescent fibroblasts was reduced after the treatment, while the expression of heat shock protein 70 and 90 was increased. Stromal derived factor-1, a senescence-associated anti-melanogenic factor secreted from the fibroblasts, was up-regulated after the treatment, while the level of c-kit was not changed. CONCLUSION: Thermal skin stimulation by the temperature-controlled continuous RF device improved melasma through dermal rejuvenation.

Three-Dimensional Photogrammetric Study on Age-Related Facial Characteristics in Korean Females.

BACKGROUND: Understanding the age-related morphological changes of facial soft tissue is fundamental in achieving improved outcomes of rejuvenating procedures. Three-dimensional (3D) photogrammetry is a reliable and convenient anthropometric tool to assess facial soft tissue. OBJECTIVE: The aim of this study was to establish age-related facial soft tissue morphology in Korean adult females using non-invasive 3D photogrammetry. METHODS: One hundred and ninety-two female participants were divided into three groups based on age: the younger group (aged 20~39 years), middle group (40~59 years), and older group (60~79 years). Thirty-six landmarks were identified via 3D photogrammetric scanning (Morpheus 3D, Morpheus Co., Ltd., Seongnam, Korea). Forty-one facial dimensions were analyzed using the imaging software to find significance between the age groups. RESULTS: Smaller upper-facial volume (p=0.019) and shorter upper-facial height (p=0.034) were observed in the older group than in the younger group. In the mid-face, narrowed palpebral fissure (p<0.001) with elongated upper eyelid height (p<0.001) and widened nose (p<0.001) were observed in the older group compared with the younger group. Longer lower-facial height (p<0.001) with longer and wider philtrum (p<0.001, p=0.004, respectively), shorter lower vermilion height (p<0.001), wider mouth width (p<0.001), and smaller lower vermilion angle (p<0.001) were seen in the older group when compared with the younger group. Moreover, greater angles of nasofrontal, nasomental, and labiomental angle (p=0.015, p=0.015, p=0.080, respectively), and smaller nasofacial angle (p=0.034) were observed in the older group than in the younger group. CONCLUSION: Our results provide clues of aging-related facial morphological characteristics in Korean female population.

The efficacy and safety of microneedle monopolar radiofrequency for the treatment of periorbital wrinkles.

BACKGROUND: Treatment of periorbital wrinkles is a challenging task because of its anatomical significance and delicate nature. OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of a microneedle monopolar radiofrequency (RF) device for treating periorbital wrinkles. METHODS AND MATERIALS: This retrospective study involved 21 patients who were treated for periorbital wrinkles using a RF device. The type of microneedle used, clinical photography, VISIA wrinkle score, and adverse events were collected from the medical chart. Two independent dermatologists assessed the photographs. RESULTS: There were 18 female and 3 male patients with a mean age of 50.24 years. The severity of wrinkle was improved according to photographic assessment and VISIA wrinkle score at 6-month post-treatment. When 21 sites treated with a long microneedle (LMN, 1.5 mm) and the other 21 sites treated with a short microneedle (SMN, 0.8 mm) were compared, significant improvement in the VISIA wrinkle score was observed only in those treated with the LMN. No serious adverse events, including scarring and postinflammatory hyperpigmentation, occurred. CONCLUSIONS: We demonstrated the efficacy and safety of the microneedle monopolar RF device in treating periorbital wrinkles. The LMN was superior to the SMN in reducing VISIA wrinkle score.

Milk Protein-Derived Antioxidant Tetrapeptides as Potential Hypopigmenting Agents.

Excessive accumulation of melanin can cause skin pigmentation disorders, which may be accompanied by significant psychological stress. Although many natural and synthetic products have been developed for the regulation of melanogenesis biochemistry, the management of unwanted skin pigmentation remains challenging. Herein, we investigated the potential hypopigmenting properties of peptide sequences that originated from milk proteins such as ĸ-casein and ß-lactoglobulin. These proteins are known to inhibit melanogenesis and their hydrolysates are reported as antioxidant peptides. We synthesize tetrapeptide fragments of the milk protein hydrolysates and investigate the amino acids that are essential for designing peptides with tyrosinase inhibitory and antioxidant activities. We found that the peptide methionine-histidine-isoleucine-arginine amide sufficiently inhibits mushroom tyrosinase activity, shows potent antioxidant activity and effectively impedes melanogenesis in cultured melanocytes via cooperative biological activities. Our findings demonstrate the potential utility of the bioactive tetrapeptide from milk proteins as a chemical alternative to hypopigmenting agents.

Antioxidants as an Epidermal Stem Cell Activator.

Antioxidants may modulate the microenvironment of epidermal stem cells by reducing the production of reactive oxygen species or by regulating the expression of extracellular matrix protein. The extracellular membrane is an important component of the stem cell niche, and microRNAs regulate extracellular membrane-mediated basal keratinocyte proliferation. In this narrative review, we will discuss several antioxidants such as ascorbic acid, plant extracts, peptides and hyaluronic acid, and their effect on the epidermal stem cell niche and the proliferative potential of interfollicular epidermal stem cells in 3D skin equivalent models.

Histone Deacetylase 1 and Sirtuin 1 Expression in Psoriatic Skin: A Comparison between Guttate and Plaque Psoriasis.

Abnormal histone modification by histone deacetylases (HDACs), including HDAC1 and sirtuin 1 (SIRT1), has been reported to play an important role in the pathogenesis of psoriasis by altering cell proliferation, differentiation, and inflammation. However, findings on the expression level of HDACs in psoriatic skin lack consistency. We assessed the expression of HDAC1, SIRT1, p63, and proliferating cell nuclear antigen (PCNA) in skin tissues from 23 patients with psoriasis (15 with plaque psoriasis and eight with guttate psoriasis) and five healthy individuals using immunohistochemistry, and analyzed their associations with clinical phenotypes of the disease. The expression of HDAC1 and keratinocyte proliferative markers, such as p63 and PCNA significantly increased, whereas that of SIRT1 decreased in the basal layer (p < 0.05) of the patients with psoriasis compared to those in healthy controls. Among the patients with psoriasis, expression of HDAC1, p63, and PCNA was significantly higher in plaque psoriasis than in guttate psoriasis. There was no significant differences in the level of SIRT1 between the two clinical phenotypes. The findings of this study suggest that histone modifications are involved in the pathogenesis of psoriasis and may contribute to the formation of clinical phenotypes.

Corrigendum: The Effects of the 3-OH Group of Kaempferol on Interfollicular Epidermal Stem Cell Fate.

[This corrects the article on p. 694 in vol. 30.].

Efficacy of liposome-encapsulated 4-n-butylresorcinol and resveratrol cream in the treatment of melasma.

BACKGROUNDS: We previously reported the efficacy of 0.1% 4-n-butylresorcinol (4nBR) cream in the treatment melasma and synergistic effect of 4nBR and resveratrol (RSV) to inhibit melanogenesis in vitro. AIMS: To evaluate efficacy and safety of a cream which contains liposome-encapsulated 4nBR and RSV in the treatment of melasma. PATIENTS/METHODS: A total of 21 female patients with melasma were treated with the cream for 4 weeks. At baseline, week 2, and week 4, melanin index (MI) of the lesional and preauricular nonlesional skin was measured and two blinded, independent dermatologists assessed the overall severity by 5-point scale. RESULTS: The lesional MI was significantly decreased at weeks 2 and 4 compared with the baseline while no significant change in the nonlesional MI was observed throughout the study. The mean investigator's global assessment score was also significantly improved at weeks 2 and 4. In patient's self-assessment, 8 (38.1%) and 11 (52.3%) patients answered moderate to significant improvement in their melasma at weeks 2 and 4, respectively. No serious adverse events were reported. CONCLUSION: The cream containing liposome-encapsulated 4nBR and RSV was shown to be effective and safe for the treatment of melasma with its effect appearing as early as 2 weeks.

Nonsurgical correction of drooping mouth corners using monophasic hyaluronic acid and incobotulinumtoxinA.

BACKGROUND: Nonsurgical correction of drooping of the corners of the mouth requires a multimodal approach combining botulinum toxin and soft tissue filler injections. OBJECTIVE: To validate a nonsurgical therapeutic approach for correcting a "saddened" appearance characterized by drooping mouth corners, oral commissures, and/or marionette lines. METHODS: In this prospective, evaluator-blinded study, monophasic hyaluronic acid (MHA) was infiltrated to correct drooping mouth corners in four steps, deep oral commissures in two steps, and/or deep marionette lines in two steps, in that order. Then, incobotulinumtoxinA was injected along the depressor anguli oris and mentalis muscles. RESULTS: The total volumes of MHA used in steps 1-4 were 0.2 mL (interquartile range [IQR]: 0.19-0.3) for the right side of the face and 0.25 mL (IQR: 0.2-0.3) for the left side; total volumes in steps 5-8 were 0.18 mL (IQR: 0-0.4) for the right side and 0.15 mL (IQR: 0-0.33) for the left side. The total mean dose of incobotulinumtoxinA was 26.5 units (IQR: 24-28). The median degrees of drooping of the mouth corners were -4° (IQR: -7° to -2°) at baseline, -1° (IQR: -3° to 1°) at post-treatment 2 weeks, and -1° (IQR: -3° to 0°) at post-treatment 3 months. Median Global Aesthetic Improvement Scale scores were 3 (IQR: 2-3) at post-treatment 2 weeks and 3 (IQR: 2-3.75) at 3 months. CONCLUSION: Our results demonstrated that nonsurgical treatment with MHA and incobotulinumtoxinA provides satisfactory therapeutic outcomes in patients with a saddened appearance by correcting drooping of the mouth corners, deep oral commissures, and/or deep marionette lines.

Reconstruction of nasal supratip defect using vertical alar groove tissue.

Background: Several local flaps have been introduced for the reconstruction of small-to-medium-sized nasal supratip defects.Objective: To evaluate the outcome of reconstructing supratip defects using tangential advancement flaps from the vertical alar groove tissue.Methods and materials: Medical records of 20 patients who underwent supratip reconstruction using this flap between January 2012 and July 2018 were retrospectively analyzed. The postoperative photographs were assessed by three dermatologists using a four-scale investigator's global assessment.Results: The male-to-female ratio was 9:11, with a mean age of 72.6 years (range, 56-89 years). In all 20 cases, defects were caused by a wide local excision of non-melanoma skin cancer on the nose. The mean diameter of the defects was 1.20 cm (ranging from 0.5 to 1.9 cm). The mean follow-up period was 14.0 months (ranging from 0.5 to 48 months). Excellent or good surgical outcome was reported in 95% of patients.Conclusions: Creating a tangential advancement flap using the vertical alar groove tissue is a simple, single-stage procedure with excellent surgical outcome. It may be useful in the reconstruction of supratip defects with a diameter of less than 2 cm.

Sandwich-structure transferable free-form OLEDs for wearable and disposable skin wound photomedicine.

Free-form optoelectronic devices can provide hyper-connectivity over space and time. However, most conformable optoelectronic devices can only be fabricated on flat polymeric materials using low-temperature processes, limiting their application and forms. This paper presents free-form optoelectronic devices that are not dependent on the shape or material. For medical applications, the transferable OLED (10 µm) is formed in a sandwich structure with an ultra-thin transferable barrier (4.8 µm). The results showed that the fabricated sandwich-structure transferable OLED (STOLED) exhibit the same high-efficiency performance on cylindrical-shaped materials and on materials such as textile and paper. Because the neutral axis is freely adjustable using the sandwich structure, the textile-based OLED achieved both folding reliability and washing reliability, as well as a long operating life (>150 h). When keratinocytes were irradiated with red STOLED light, cell proliferation and cell migration increased by 26 and 32%, respectively. In the skin equivalent model, the epidermis thickness was increased by 39%; additionally, in organ culture, not only was the skin area increased by 14%, but also, re-epithelialization was highly induced. Based on the results, the STOLED is expected to be applicable in various wearable and disposable photomedical devices.

Components of Metabolic Syndrome in Korean Adults: A Hospital-Based Cohort at Seoul National University Bundang Hospital.

BACKGROUND: The prevalence of metabolic syndrome is increasing in Korea, particularly among young adults. This trend will increase the incidence of cardiovascular and metabolic diseases in the future. Therefore, it is imperative to detect and prevent metabolic abnormalities early in life. Here, we established a hospital-based biobank cohort to identify the most prevalent dysmetabolic phenotype. The aim of this report was to inform other researchers of our protocol and to share our data for future collaboration. METHODS: The baseline examination comprised health-related questionnaires, anthropometric and handgrip strength measurements, bioelectrical impedance analysis of body composition, and nutritional assessment. Relevant biochemical parameters were measured, and oral glucose tolerance tests were performed. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria with Asian waist circumference criteria. RESULTS: From a total of about 3,000 employees aged 20 to 59 years working at Seoul National University Bundang Hospital, 1,017 were enrolled from 2015 to 2016. The mean age was 34.5±8.4 years for men (n=311, 30.6%) and 30.9±8.5 years for women (n=706, 69.4%). The overall prevalence of metabolic syndrome was 7.6% (17.7% in men and 3.1% in women). Among the five components of metabolic syndrome, high blood pressure was the most prevalent in both men (51.4%) and women (13.8%). CONCLUSION: Although further follow-up data are needed, we expect that more adverse cardiovascular events may occur in men than in women. This hospital-based cohort will serve as the foundation for a comprehensive evaluation of metabolic syndrome and future cardiometabolic disease risk in middle-aged Koreans.

The efficacy of micro-insulated needle radiofrequency system for the treatment of lower eyelid fat bulging.

BACKGROUND AND OBJECTIVES: Conventional treatment options for eyelid fat bulging are generally limited to surgical approaches. However, many attempts have been made recently to manage this disfigurement using non-surgical interventions. The purpose of this study was to evaluate the efficacy and safety of a micro-insulated needle radiofrequency system for the treatment of lower eyelid fat bulging. METHODS: This is a single center pre-post comparative study. Twenty-two subjects with lower eyelid fat bulging were treated twice using the needle radiofrequency system, at an interval of four weeks. Two types of partially insulated needles with different lengths were used in each session. A three-dimensional photogrammetry system was used to objectively measure changes in the extent of the fat bulge. The investigator's global assessment (IGA) of the severity of fat bulging was also evaluated. RESULTS: The average extent of fat bulging was decreased significantly after twelve weeks, and was maintained until 24 weeks. The IGA score was significantly decreased after four weeks and further decreased after twelve weeks, and then maintained until 24 weeks. There were no side effects, except for lower eyelid swelling and bruising that lasted for about a week. CONCLUSION: The micro-insulated needle radiofrequency system can be a beneficial and well-tolerated treatment for lower eyelid fat bulging.