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The extensive utilization of electronic health records (EHRs) and the growth of enormous open biomedical datasets has readied the area for applications of computational and machine learning techniques to reveal fundamental patterns. This study’s goal is to develop a medical treatment recommendation system using Korean EHRs along with the Markov decision process (MDP). The sharing of EHRs by the National Health Insurance Sharing Service (NHISS) of Korea has made it possible to analyze Koreans’ medical data which include treatments, prescriptions, and medical check-up. After considering the merits and effectiveness of such data, we analyzed patients’ medical information and recommended optimal pharmaceutical prescriptions for diabetes, which is known to be the most burdensome disease for Koreans. We also proposed an MDP-based treatment recommendation system for diabetic patients to help doctors when prescribing diabetes medications. To build the model, we used the 11-year Korean NHISS database. To overcome the challenge of designing an MDP model, we carefully designed the states, actions, reward functions, and transition probability matrices, which were chosen to balance the tradeoffs between reality and the curse of dimensionality issues.

Cybersecurity is a growing concern in today’s interconnected world. Traditional cybersecurity approaches, such as signature-based detection and rule-based firewalls, are often limited in their ability to effectively respond to evolving and sophisticated cyber threats. Reinforcement learning (RL) has shown great potential in solving complex decision-making problems in various domains, including cybersecurity. However, there are significant challenges to overcome, such as the lack of sufficient training data and the difficulty of modeling complex and dynamic attack scenarios hindering researchers’ ability to address real-world challenges and advance the state of the art in RL cyber applications. In this work, we applied a deep RL (DRL) framework in adversarial cyber-attack simulation to enhance cybersecurity. Our framework uses an agent-based model to continuously learn from and adapt to the dynamic and uncertain environment of network security. The agent decides on the optimal attack actions to take based on the state of the network and the rewards it receives for its decisions. Our experiments on synthetic network security show that the DRL approach outperforms existing methods in terms of learning optimal attack actions. Our framework represents a promising step towards the development of more effective and dynamic cybersecurity solutions.

Two advanced, automated crystal orientation mapping techniques suited for nanocrystalline materials—precession electron diffraction (PED) in transmission electron microscopy (TEM) and on-axis transmission Kikuchi diffraction (TKD) in scanning electron microscopy (SEM)—are evaluated by comparing the orientation maps obtained from the identical location on a 30 nm-thick nanocrystalline tungsten (W) thin film. A side-by-side comparison of the orientation maps directly showed that the large-scale orientation features are almost identical. However, there are differences in the fine details, which arise from the fundamentally different nature of the spot pattern and Kikuchi line pattern in terms of the excitation volume and the angular resolution. While TEM-PED is more reliable to characterize grains oriented along low-index zone axes, the high angular resolution of SEM-TKD allows the detection of small misorientation between grains and thus yields better quantification and statistical analysis of grain orientation. Given that both TEM-PED and SEM-TKD orientation mapping techniques are complementary tools for nanocrystalline materials, one can be favorably selected depending on the requirements of the analysis, as they have competitive performance in terms of angular resolution and texture quantification.

Classification of facial and truncal segmental vitiligo and its clinical courses including recurrence rate and patterns: a retrospective review of 956 patients

Vitiligo is a relatively common, acquired hypopigmentary disorder caused by the loss of epidermal melanocytes. It is characterized by asymptomatic, well-circumscribed round to oval-shaped whitish patches that vary in size. Depending on various clinical features, vitiligo is classified into several types, that is, non-segmental, segmental, and undetermined/unclassified vitiligo. The uniform classification of vitiligo is very important in predicting its clinical course and prognosis and communication among researchers. In particular, segmental vitiligo is a highly distinctive subtype of vitiligo considering its clinical features and prognosis. It usually has an onset early in life and spreads rapidly within the affected area limited to one segment of the integument. Signs of vitiligo activity such as Koebnerʼs phenomenon, trichrome vitiligo, inflammatory vitiligo, and confetti-like lesions give useful information to start treatments to block the progression of the disease. Lastly, other hypopigmentary disorders should be distinguished from vitiligo to make the correct diagnosis and prescribe the right treatment. In this report, I review the clinical features of vitiligo, various subtypes according to classification, and the importance for differential diagnosis of hypopigmentary disorders from vitiligo.

Background and objectives The treatment of Riehl's melanosis, also known as pigmented contact dermatitis, is highly challenging. Intense pulsed light (IPL) and 1064 nm Q-switched Nd:Yag (QS-Nd:YAG) laser are reported to have some efficacy. However, no single effective treatment has yet been identified. In this study, we demonstrated the efficacy and safety of the non-ablative 1927 nm fractional thulium fiber laser (TFL, LASEMD™; Lutronic Corp., Goyang, Korea) for patients with Riehl's melanosis. Study design/materials and methods A retrospective chart and photographic review of nine patients with Riehl's melanosis, who had received at least three sessions of TFL treatment, was performed. Before the start of TFL treatment, combination treatment with a topical cream containing hydroquinone, low-fluence QS-Nd:YAG laser, pulsed dye laser, and IPL was used with variable and discouraging effects. Seven patients were treated on the face and two patients on the neck with three to seven sessions at 1-month intervals. Clinical improvement was assessed using clinical photos taken before and after every treatment session according to dermal pigmentation area and severity index (DPASI) and a quartile grading scale by two blinded dermatologists. Results Patients underwent three to seven sessions of TFL treatment depending on severity of pigmentation. Of nine patients, six demonstrated a clinical improvement of 51%-75%, one demonstrated an improvement of 76%-100%, and two showed an improvement of 26%-50% after treatment. The DPASI was significantly decreased from 9.55 to 5.25 on average. Melanin index was decreased after treatment in two patients whose melanin index were measured at initial visits. Treatment-related adverse events, such as scarring or postinflammatory hyperpigmentation (PIH), were not observed in all patients except for transient erythema and swelling. Conclusions This report suggests that TFL could be an alternative and/or additive treatment option for hyperpigmentation in intractable Riehl's melanosis and might be a promising treatment for PIH caused by any reason including Riehl's melanosis. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

The combined use of oral isotretinoin with energy-based interventions including fractional microneedle radiofrequency, pulsed dye laser, and ablative fractional laser is an effective way to treat moderate-to-severe inflammatory acne lesions. However, studies regarding its efficacy and safety are limited.This study aimed to assess the efficacy and safety of a treatment using low-dose isotretinoin with energy-based interventions for inflammatory acne.This retrospective cohort study included 126 patients who were diagnosed with inflammatory acne and were treated with systemic isotretinoin for at least 3 months. Patients were divided into EBD (energy-based intervention) (n = 82) and non-EBD groups (n = 44). Clinical outcomes of both groups were assessed using medical records and digital photographs.After treatment, the modified Global Acne Grading Score of the EBD and non-EBD groups decreased by 35.1 ± 17.2 and 25.6 ± 10.1, respectively. The improvement in acne severity was significantly greater in the EBD group than in the non-EBD group. Cumulated isotretinoin dose and frequency of drug-related side effects were significantly higher in the non-EBD group than in the EBD group.Combined treatment with low-dose isotretinoin and energy-based intervention is well tolerated and associated with positive responses in patients with inflammatory acne.

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Background/purpose Vitiligo remains a major challenge in dermatology. However, much of the treatment remains unclear, because little evidence is available. We sought to answer some critical questions pertaining to management of vitiligo patients. Methods A modified Delphi process among 31 vitiligo experts was conducted. A total of 12 clinical vitiligo treatment questions without clear answers were collected via a vote. To address each question, two members performed systematic literature reviews and prepared draft statements along with the levels of evidence and strength of recommendation. After reviewing the draft, all expressed their extent of agreement from 1 (strong disagreement) to 9 (strong agreement) for each item. The drafts were revised to reflect suggested comments. Discussion continued until all members agreed with the ultimate decision. Results The consensus process was completed after five rounds. We identified the best answers to 12 key questions, including issues on long-term phototherapy, systemic and topical corticosteroids, topical calcineurin inhibitors, immunosuppressants, excimer laser treatment, and surgical interventions. Conclusion This consensus would complement current guidelines and aid both physician and patient decision-making in the treatment of vitiligo.

Background Argyria results from silver accumulation in the skin. It is a stressful condition for patients due to skin discoloration. In the past, no effective treatments were available. However, it has been recently reported laser treatments showed promising results. Aim To review and summarize all reported laser treatment options for argyria patients. Methods We reviewed all laser treatment options for argyria in the database of the US National Library of Medicine PubMed. The search of the words "argyria and laser" was performed on the March 4, 2020. Results We found 11 studies that reported laser treatment for argyria. All of the studies were case reports demonstrating treatment responses of laser devices such as 1064 nm Nd:Yag laser and 755 nm alexandrite laser. Despite various treatment parameters, 1064 nm Nd:Yag and alexandrite lasers showed good responses in argyria. However, severe pain during the laser procedure was the main concern. We summarized laser treatment options for argyria including their parameters, treatment response, and anesthesia for laser treatment in argyria. We also report a case of argyria, which successfully responded to low fluence 1064 nm Nd:Yag laser. Conclusion Laser therapies resulted in almost complete clearing of pigment in argyria. Earlier reports showed that 1064 nm Nd:Yag laser successfully treated argyria but recent studies suggested 755 nm alexandrite was also a good treatment option for argyria. Additionally, our case achieved excellent results even in one session of low fluence Q-switched Nd:Yag laser, though we need to ensure pain control during the laser treatment.

Lithium–sulfur batteries present unique polysulfide chemistry and exhibit a high theoretical energy density of 2600 W h kg−1. However, soluble lithium polysulfides (LiPSs) tend to shuttle during battery cycling and corrode the Li anode; this leads to an eventual performance fading in the Li–S battery. This shuttle effect can be reduced by accelerating the conversion of dissolved polysulfides to insoluble LiPSs and back to sulfur. Herein, a novel 2D Mo0.5W0.5S2 alloy with a 2H (semiconducting)-1T (metallic) mixed-phase is synthesized on carbon nanotubes (CNTs) by a two-step process of co-sputtering and sulfurization. The cathode comprising 2D Mo0.5W0.5S2–CNTs exhibits the synergistic effect of accelerated electron transfer, a higher LiPS binding effect, and good catalytic performance, as confirmed by our electrochemical analysis. As a result, the Li–S battery cell assembled with the 2D Mo0.5W0.5S2/CNT/S cathode shows a high specific capacity of 1228 mA h g−1 at 0.1C and a much higher cycling stability as compared to the pristine cathodes. Our results confirm that the 2D Mo0.5W0.5S2 alloy catalyst deposited on the CNTs can effectively prevent polysulfide shuttling and offer a viable solution to overcome the technical challenges in the development of practical Li–S batteries.

The reliability of Ge–Sb–Te phase-change memory (PCM) devices has been limited by failure due to void formation and this still remains one of the critical issues affecting their use in storage-class memory applications. To directly observe the void formation processes in real-time, we implemented in situ switching of PCM devices by applying set and reset voltage pulses to a Ge2Sb2Te5 (GST) cell inside a transmission electron microscope (TEM). The in situ TEM observations directly show that a void nucleates preferentially near the TiN bottom electrode in the GST cell, where the temperature is the highest. The nucleated void grows gradually until it reaches a certain size while migrating slowly toward the positively biased electrode. The fully grown void then continues migrating toward the positively biased electrode in subsequent set pulses. The observed polarity-dependent void migration can be explained by the field-induced redistribution of the constituent elements, especially by the electromigration of under-coordinated Te− ions which have vacancies around them. When the reset pulse with the same voltage polarity is applied, the voids exhibit a slight volume shrinkage but are not completely eliminated, resulting in a reset-stuck failure. The present in situ TEM observations revealing the nucleation, growth, and polarity-dependent migration of voids will contribute to the fundamental understanding of the failure by void formation in nanoscale GST-based PCM devices and help improving the design of reliable PCM devices.

Electrocatalysts for CO2 electroreduction require not only high-performance active materials to control the series reaction but also conductive and durable supports to ensure long-term stability under harsh operating conditions. Instead of conventional heterogeneous catalysts made by attaching metal on supports, we manufactured a self-formed tandem catalyst designed for a cascade electroreduction of CO2 to C2H4. Using oxygen partial pressure-controlled calcination, electrospun copper acetate/polyacrylonitrile nanofibers were successfully transformed into porous carbon nanofibers consisting of doped N and metallic Cu particles. Doped nitrogen atoms adjacent to Cu atoms trigger the reaction by increasing the amount of CO* on the Cu surfaces, which lowers the energy required for CO dimerization that is used for C2H4 production. The Cu-embedded N-doped carbon nanofibers exhibit a C2H4 faradaic efficiency of 62% at a potential of −0.57 V vs. RHE with high current density of 600 mA cm−2 and excellent long-term stability. DFT calculations suggest that the lowered overpotential originates from the decreased CO dimerization energy barrier due to the doped N triggering CO production around the Cu particles.

As the properties of a semiconductor material depend on the fate of the excitons, manipulating exciton behavior is the primary objective of nanomaterials. Although nanocrystals exhibit unusual excitonic characteristics owing to strong spatial confinement, studying the interactions between excitons in a single nanoparticle remains challenging due to the rapidly vanishing multiexciton species. Here, a platform for exciton tailoring using a straightforward strategy of shape-tuning of single-crystalline nanocrystals is presented. Spectroscopic and theoretical studies reveal a systematic transition of exciton confinement orientation from 3D to 2D, which is solely tuned by the geometric shape of material. Such a precise shape-effect triggers a multiphoton emission in single nanotetrapods with arms longer than the exciton Bohr radius of material. In consequence, the unique interplay between the multiple quantum states allows a geometric modulation of the quantum-confined Stark effect and nanocrystal memory effect in single nanotetrapods. These results provide a useful metric in designing nanomaterials for future photonic applications.

CXCL12 and its receptors, which are highly expressed in the skin, are associated with various cutaneous diseases, including androgenic alopecia. However, their expression and role during the hair cycle are unknown. This study aims to investigate the expression of CXCL12 and its receptor, CXCR4, in the vicinity of hair follicles and their effect on hair growth. CXCL12 was highly expressed in dermal fibroblasts (DFs) and its level was elevated throughout the catagen and telogen phases of the hair cycle. CXCR4 is expressed in the dermal papilla (DP) and outer root sheath (ORS). In hair organ culture, hair loss was induced by recombinant CXCL12 therapy, which delayed the telogen-to-anagen transition and decreased hair length. In contrast, the suppression of CXCL12 using a neutralizing antibody and siRNA triggered the telogen-to-anagen transition and increased hair length in hair organ culture. Neutralization of CXCR7, one of the two receptors for CXCL12, only slightly affected hair growth. However, inhibition of CXCR4, the other receptor for CXCL12, increased hair growth to a considerable extent. In addition, in hair organ culture, the conditioned medium from DFs with CXCL12 siRNA considerably increased the hair length and induced proliferation of DP and ORS cells. CXCL12, through CXCR4 activation, increased STAT3 and STAT5 phosphorylation in DP and ORS cells. In contrast, blocking CXCL12 and CXCR4 decreased the phosphorylation of STAT3 and STAT5. In summary, these findings suggest that CXCL12 inhibits hair growth via the CXCR4/STAT signaling pathway and that CXCL12/CXCR4 pathway inhibitors are a promising treatment option for hair growth.

Despite the enormous applications of and fundamental scientific interest in amorphous hollow-silica nanostructures (

Precision medicine is a new approach to understanding health and disease based on patient-specific data such as medical diagnoses; clinical phenotype; biologic investigations such as laboratory studies and imaging; and environmental, demographic, and lifestyle factors. The importance of machine learning techniques in healthcare has expanded quickly in the last decade owing to the rising availability of vast multi-modality data and developed computational models and algorithms. Reinforcement learning is an appealing method for developing efficient policies in various healthcare areas where the decision-making process is typically defined by a long period or a sequential process. In our research, we leverage the power of reinforcement learning and electronic health records of South Koreans to dynamically recommend treatment prescriptions, which are personalized based on patient information of hypertension. Our proposed reinforcement learning-based treatment recommendation system decides whether to use mono, dual, or triple therapy according to the state of the hypertension patients. We evaluated the performance of our personalized treatment recommendation model by lowering the occurrence of hypertension-related complications and blood pressure levels of patients who followed our model’s recommendation. With our findings, we believe that our proposed hypertension treatment recommendation model could assist doctors in prescribing appropriate antihypertensive medications.

Dislocations in single-phase concentrated random alloys, including high- entropy alloys (HEAs), repeatedly encounter pinning during glide, resulting in jerky dislocation motion. While solute-dislocation interaction is well understood in conventional alloys, the origin of individual pinning points in concentrated random alloys is a matter of debate. In this work, we investigate the origin of dislocation pinning in the CoCrFeMnNi HEA. In- situ transmission electron microscopy studies reveal wavy dislocation lines and a jagged glide motion under external loading, even though no segregation or clustering is found around Shockley partial dislocations. Atomistic simulations reproduce the jerky dislocation motion and link the repeated pinning to local fluctuations in the Peierls friction. We demonstrate that the density of high local Peierls friction is proportional to the critical stress required for dislocation glide and the dislocation mobility., Accepted version

We investigated the role of graphene interfaces in strengthening and toughening of the Cu-graphene nanocomposite by a combination of

Nacre's superior mechanical properties and failure behavior are strongly orientation-dependent due to its brick-and-mortar microstructure. In this work, the anisotropic microscopic deformation and the resulting macroscopic mechanical properties are evaluated under different loading conditions. Our in situ transmission electron microscopy deformation experiments and finite element simulations reveal that nacre possesses enhanced indentation resistance along the direction normal to the tablets through delocalization of indentation-induced deformation by taking advantage of its layered structure. In addition, nacre's ability to recover from large deformations is observed. We study the strong loading direction dependence of nacre's macroscopic mechanical properties and elucidate the underlying microscopic deformation patterns in the tablets and the soft matrix. Particularly, its performance along the transverse direction is optimized to withstand the loading conditions in nature. We show the importance of the vertical matrix for the initial stiffness and fracture toughness of the composite. These findings provide guidelines for designing nacre-inspired artificial composites with enhanced mechanical properties. STATEMENT OF SIGNIFICANCE: Nacre is widely recognized as an excellent structural model for designing bio-inspired tough and strong artificial composites. Due to its brick-and-mortar microstructure, it exhibits loading direction-dependent mechanical behavior. In this contribution, we investigate the macroscopic mechanical properties and microscopic deformation behavior of nacre under different loading conditions by means of in situ TEM deformation tests and FE simulations. It is found that effective elastic moduli and microscopic deformation strongly depend on the loading direction. The organic matrix is highly deformable. The indentation resistance along the direction normal to tablets is enhanced via deformation delocalization. Our quantitative and qualitative results provide guidelines on optimizing the mechanical properties of nacre-inspired novel composites.

Demands for high-performance displays with high pixel density and picture quality are ever increasing. Indium gallium nitride (InGaN)-based micro-LEDs (μLEDs) are suitable for meeting such demands owing to their high efficiency, brightness, and stability. However, the poor yield of the pick-and-place technique, defect repair, and visibility of edge lines between modules limit the applications of μLEDs. Furthermore, the external quantum efficiency (EQE) decreases (

Oh, S.-H. and Park, W.S., 2021. Experimental comparison of hydrodynamic characteristics of submerged floating tunnel with different cross-sectional shape. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 46–50. Coconut Creek (Florida), ISSN 0749-0208. This study conducted physical experiments to investigate hydrodynamic characteristics of the submerged floating tunnel (SFT) under wave loading, when the cross-sectional shape of the SFT was either oval or rectangular. By analyzing the experimental data, the performance of the two SFT models were compared with that of the conventional SFT of circular cross-section, which already reported by a previous study (Oh et al., 2013). The experimental results showed that the tensile forces on the tethering lines and the associated wave pressures on the SFT body apparently vary according to the change of the cross-sectional shape of the SFT. In general, the rectangular cross-section was less effective because the tensile forces on the tethering lines and the pressures on the SFT body were greater than those of the oval cross-section.

The International Society for Cutaneous Lymphoma (ISCL) proposes a diagnostic algorithm for early mycosis fungoides (MF) that includes clinical, histological, immunophenotypical, and molecular criteria. Here, we analyzed the immunologic markers and features of T-cell clonality in 38 early MF cases and 22 non-MF cases to validate the ISCL algorithm. We found that CD5 and CD7 expression differed significantly between early MF and non-MF cases, with epidermal discordance of CD7 expression more frequently identified in early MF. Notably, increasing the cut-off value for CD7 expression from 10% to 22.5% improved its sensitivity. Furthermore, TCR-γ and β chain rearrangements were more frequently detected in early MF than in non-MF cases. Based on these findings, we propose CD5 and CD7 deficiency as mandatory immunopathologic criteria and PCR-based testing for TCR-γ and β chains as required molecular/biologic criteria to improve the efficiency of early MF diagnosis using the ISCL algorithm.

Freestanding membranes of electronically reconfigurable complex oxide heterostructure are demonstrated., In recent years, lanthanum aluminate/strontium titanate (LAO/STO) heterointerfaces have been used to create a growing family of nanoelectronic devices based on nanoscale control of LAO/STO metal-to-insulator transition. The properties of these devices are wide-ranging, but they are restricted by nature of the underlying thick STO substrate. Here, single-crystal freestanding membranes based on LAO/STO heterostructures were fabricated, which can be directly integrated with other materials via van der Waals stacking. The key properties of LAO/STO are preserved when LAO/STO membranes are formed. Conductive atomic force microscope lithography is shown to successfully create reversible patterns of nanoscale conducting regions, which survive to millikelvin temperatures. The ability to form reconfigurable conducting nanostructures on LAO/STO membranes opens opportunities to integrate a variety of nanoelectronics with silicon-based architectures and flexible, magnetic, or superconducting materials.

Hypoxic conditions induce the activation of hypoxia-inducible factor-1α (HIF-1α) to restore the supply of oxygen to tissues and cells. Activated HIF-1α translocates into the nucleus and binds to hypoxia response elements to promote the transcription of target genes. Cathepsin L (CTSL) is a lysosomal protease that degrades cellular proteins via the endolysosomal pathway. In this study, we attempted to determine if CTSL is a hypoxia responsive target gene of HIF-1α, and decipher its role in melanocytes in association with the autophagic pathway. The results of our luciferase reporter assay showed that the expression of CTSL is transcriptionally activated through the binding of HIF1-α at its promoter. Under autophagy-inducing starvation conditions, HIF-1α and CTSL expression is highly upregulated in melan-a cells. The mature form of CTSL is closely involved in melanosome degradation through lysosomal activity upon autophagosome–lysosome fusion. The inhibition of conversion of pro-CTSL to mature CTSL leads to the accumulation of gp100 and tyrosinase in addition to microtubule-associated protein 1 light chain 3 (LC3) II, due to decreased lysosomal activity in the autophagic pathway. In conclusion, we have identified that CTSL, a novel target of HIF-1α, participates in melanosome degradation in melanocytes through lysosomal activity during autophagosome–lysosome fusion.

We report the discovery of a new three-dimensional (3D) topological Dirac semimetal (TDS) material KZnBi, coexisting with a naturally formed superconducting state on the surface under ambient pressure. Using photoemission spectroscopy together with first-principles calculations, a 3D Dirac state with linear band dispersion is identified. The characteristic features of massless Dirac fermions are also confirmed by magnetotransport measurements, exhibiting an extremely small cyclotron mass of m^{*}=0.012 m_{0} and a high Fermi velocity of v_{F}=1.04×10^{6} m/s. Interestingly, superconductivity occurs below 0.85 K on the (001) surface, while the bulk remains nonsuperconducting. The captured linear temperature dependence of the upper critical field suggests the possible non-s-wave character of this surface superconductivity. Our discovery serves a distinctive platform to study the interplay between 3D TDS and the superconductivity.

Copper (Cu) nanoparticles (NPs) have received extensive interest owing to their advantageous properties compared with their bulk counterparts. Although the natural oxidation of Cu NPs can be alleviated by passivating the surfaces with additional moieties, obtaining non-oxidized bare Cu NPs in air remains challenging. Here we report that bare Cu NPs with surface excess electrons retain their non-oxidized state over several months in ambient air. Cu NPs grown on an electride support with excellent electron transfer ability are encapsulated by the surface-accumulated excess electrons, exhibiting an ultralow work function of ~3.2 eV. Atomic-scale structural and chemical analyses confirm the absence of Cu oxide moiety at the outermost surface of air-exposed bare Cu NPs. Theoretical energetics clarify that the surface-accumulated excess electrons suppress the oxygen adsorption and consequently prohibit the infiltration of oxygen into the Cu lattice, provoking the endothermic reaction for oxidation process. Our results will further stimulate the practical use of metal NPs in versatile applications.

Autophagy regulates cellular turnover by disassembling unnecessary or dysfunctional constituents. Recent studies demonstrated that autophagy and its regulators play a wide variety of roles in melanocyte biology. Activation of autophagy is known to induce melanogenesis and regulate melanosome biogenesis in melanocytes. Also, autophagy induction was reported to regulate physiologic skin color via melanosome degradation, although the downstream effectors are not yet clarified. To determine the role of autophagy as a melanosome degradation machinery, we administered several autophagy inducers in human keratinocytes and melanocytes. Our results showed that the synthetic autophagy inducer PTPD-12 stimulated autophagic flux in human melanocytes and in keratinocytes containing transferred melanosomes. Increased autophagic flux led to melanosome degradation without affecting the expression of MITF. Furthermore, the color of cell pellets of both melanocytes and keratinocytes was visibly lightened. Inhibition of autophagic flux by chloroquine resulted in marked attenuation of PTPD-12-induced melanosome degradation, whereas the expression of melanogenesis pathway genes and proteins remained unaffected. Taken together, our results suggest that the modulation of autophagy can contribute to the regulation of melanocyte biology and skin pigmentation.

Despite the remarkable electronic and mechanical properties of graphene, improving the catalytic activity of the atomically flat, inert, and stable carbon network remains a challenging issue in both fundamental and application studies. In particular, the adsorption of most molecules and ions, including hydrogen (H2 or H+), on graphene is not favorable, underlining the challenge for an efficient electrochemical catalytic reaction on graphene. Various defects, edges, and functionalization have been suggested to resolve the catalytic issue in graphene, but cost-effectiveness and active catalysis with graphene have not been achieved yet. Here, we introduce dynamic stacking of reduced graphene oxide (rGO) with spontaneously generated hydrogen bubbles to form an efficient electrochemical catalyst with a graphene derivative; the in operando stacking of rGO, without using a high-temperature-based heteroatom doping process or plasma treatment, creates a large catalytic surface area with optimized edges and acidic groups in the rGO. Thus, the uniquely formed stable carbon network achieves active hydrogen evolution with a Tafel slope of 39 mV·dec-1 and a double layer capacitance of 12.41 mF·cm-2, which breaks the conventional limit of graphene-based catalysis, suggesting a promising strategy for metal-free catalyst engineering and hydrogen production.

In situ nanomechanical testing in (scanning) transmission electron microscopy provides unique opportunities for studying fundamental deformation processes in materials. New insights have been gained by combining advanced imaging techniques with novel preparation methods and controlled loading scenarios. For instance, by applying in situ high-resolution imaging during tensile deformation of metallic nanostructures, the interplay of dislocation slip and surface diffusion has been identified as the key enabler of superplasticity. Evidence for dislocation pinning by hydrogen defect complexes has been provided by in situ imaging under cyclic pillar compression in a tunable gas environment. And, for the very first time, individual dislocations have been moved around in situ in two-dimensional materials by combining micromanipulation and imaging in a scanning electron microscope.

Product sales forecasting is one of the factors that gives significant impact on the company's sales and production plans. In order to increase the accuracy of sales forecast, companies are trying to reflect the opinions of consumers. In this study, we reconfirm the work of Hwang(2017) which analyzed the consumer review by applying the information gain to predict the product sales. This study is meaningful in that it applies the research model to the automobile market, which is one of the traditional durable goods market. Compared to the smartphone market, which has a short product life cycle, the automobile market has well-defined consumers and products are specifically targeted to each consumer group. In this paper, we verify the applicability and predictive power of proposed methodology of Hwang(2017) using actual market data, and show the relationship between information gain from online consumer review and product sales.

Symmetrical giant facial plaque-type juvenile xanthogranuloma (SGFP-JXG) is a rare variant of juvenile xanthogranuloma, reported only in two cases in the literature. We report a case of a 3-year-old Korean boy who developed bilateral yellowish indurated plaques on both cheeks since 1 year after birth. A skin biopsy revealed numerous foam cells and Touton type giant cells throughout the upper dermis, and its immunohistochemical studies resulted positive for CD68 and negative for S-100. The boy was therefore diagnosed as a persistent SGFP-JXG. As the lesion did not show any signs of spontaneous regression, we performed a single session of fractional ablative CO2 laser, which resulted in a significant reduction of the lesion. This is the first case report of a persistent SGFP-JXG on which a single ablative laser therapy was performed with a successful outcome.

The origin of 2D electron gas (2DEG) at LaAlO3/SrTiO3 (LAO/STO) interfaces has remained highly controversial since its discovery. Various models are proposed, which include electronic reconstruction via surface‐to‐interface charge transfer and defect‐mediated doping involving cation intermixing or oxygen vacancy (V O) formation. It is shown that the polar field‐assisted V O formation at the LAO/STO surface plays critical roles in the 2DEG formation and concurrent structural transition. Comprehensive scanning transmission electron microscopy analyses, in conjunction with density functional theory calculations, demonstrate that V O forming at the LAO/STO surface above the critical thickness (t c) cancels the polar field by doping the interface with 2DEG. The antiferrodistortive (AFD) octahedral rotations in LAO, which are suppressed below the t c, evolve with the formation of V O above the t c. The present study reveals that local symmetry breaking and shallow donor behavior of V O induce the AFD rotations and relieve the electrical field by electron doping the oxide heterointerface., Comprehensive scanning transmission electron microscopy analyses, in conjunction with density functional theory calculations, demonstrate that oxygen vacancy forming at LaAlO3/SrTiO3 (001) surface above the critical thickness (t c) cancels the polar electric field by doping the interface with two‐dimensional electron gas. The antiferrodistortive octahedral rotations in LaAlO3, which are suppressed below t c, evolve with the formation of oxygen vacancy above t c.

Oxide interface orientation tunes ferroelectric distortion and antiferrodistortive rotation into competition or cooperation., Polarity discontinuity across LaAlO3/SrTiO3 (LAO/STO) heterostructures induces electronic reconstruction involving the formation of two-dimensional electron gas (2DEG) and structural distortions characterized by antiferrodistortive (AFD) rotation and ferroelectric (FE) distortion. We show that AFD and FE modes are cooperatively coupled in LAO/STO (111) heterostructures; they coexist below the critical thickness (tc) and disappear simultaneously above tc with the formation of 2DEG. Electron energy-loss spectroscopy and density functional theory (DFT) calculations provide direct evidence of oxygen vacancy (VO) formation at the LAO (111) surface, which acts as the source of 2DEG. Tracing the AFD rotation and FE distortion of LAO reveals that their evolution is strongly correlated with VO distribution. The present study demonstrates that AFD and FE modes in oxide heterostructures emerge as a consequence of interplay between misfit strain and polar field, and further that their combination can be tuned to competitive or cooperative coupling by changing the interface orientation.

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Nuclear factor erythroid 2-related factor 2 (Nrf2), which is linked to autophagy regulation and melanogenesis regulation, is activated by marliolide. In this study, we investigated the effect of a marliolide derivative on melanosome degradation through the autophagy pathway. The effect of the marliolide derivative on melanosome degradation was investigated in α-melanocyte stimulating hormone (α-MSH)-treated melanocytes, melanosome-incorporated keratinocyte, and ultraviolet (UV)B-exposed HRM-2 mice (melanin-possessing hairless mice). The marliolide derivative, 5-methyl-3-tetradecylidene-dihydro-furan-2-one (DMF02), decreased melanin pigmentation by melanosome degradation in α-MSH-treated melanocytes and melanosome-incorporated keratinocytes, evidenced by premelanosome protein (PMEL) expression, but did not affect melanogenesis-associated proteins. The UVB-induced hyperpigmentation in HRM-2 mice was also reduced by a topical application of DMF02. DMF02 activated Nrf2 and induced autophagy in vivo, evidenced by decreased PMEL in microtubule-associated proteins 1A/1B light chain 3B (LC3)-II-expressed areas. DMF02 also induced melanosome degradation via autophagy in vitro, and DMF02-induced melanosome degradation was recovered by chloroquine (CQ), which is a lysosomal inhibitor. In addition, Nrf2 silencing by siRNA attenuated the DMF02-induced melanosome degradation via the suppression of p62. DMF02 induced melanosome degradation in melanocytes and keratinocytes by regulating autophagy via Nrf2-p62 activation. Therefore, Nrf2 activator could be a promising therapeutic agent for reducing hyperpigmentation.