The electrical and optical improvements of AlGaInP micro-light-emitting diodes (µLEDs) using atomic-layer deposition (ALD) sidewall passivation were demonstrated. Due to the high surface recombination velocity and minority carrier diffusion length of the AlGaInP material system, devices without sidewall passivation suffered from high leakage and severe drop in external quantum efficiency (EQE). By employing ALD sidewall treatments, the 20×20 µm2 µLEDs resulted in greater light output power, size-independent leakage current density, and lower ideality factor. The forward current-voltage characteristic was enhanced by using surface pretreatment. Furthermore, ALD sidewall treatments recovered the EQE of the 20×20 µm2 devices more than 150%. This indicated that AlGaInP µLEDs with ALD sidewall treatments can be used as the red emitter for full-color µLED display applications.

Metabolite profiling of four different-sized Aloe vera plants was performed using gas chromatography-ion trap-mass spectrometry (GC-IT-MS) and ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) with multivariate analysis. Amino acids, sugars, and organic acids related to growth and development were identified by sizes. In particular, the relative contents of glucose, fructose, alanine, valine, and aspartic acid increased gradually as the size of the aloe increased. Anthraquinone derivatives such as 7-hydroxy-8-O-methylaloin, 7-hydroxyaloin A, and 6'-malonylnataloins A and B increased gradually, whereas chromone derivatives decreased continuously as the size of the aloe increased. The A30 aloe (size = 20-30 cm) with relatively high contents of aloins A and B, was suggested to have antioxidant components showing the highest antioxidant activity among the four different sizes of aloe. These data suggested that MS-based metabolomic approaches can illuminate metabolite changes associated with growth and development and can explain their change of antioxidant activity.

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Ultraviolet (UV) irradiation induces photo-damage of the skin, which in turn causes depletion of the dermal extracellular matrix and chronic alterations in skin structure. Skin wrinkle formations are associated with collagen synthesis and matrix metalloproteinase (MMP) expression. The production of type I procollagen is regulated by transforming growth factor-β1 (TGF-β1) expression; the activation of MMP is also correlated with an increase of interleukin-6 (IL-6). Aloe barbadensis M. (Aloe vera) is widely used in cosmetic and pharmaceutical products. In this study, we examined whether baby aloe shoot extract (BAE, immature aloe extract), which is from the one-month-old shoots of Aloe vera, and adult aloe shoot extract (AE), which is from the four-month-old shoots of Aloe vera, have a protective effect on UVB-induced skin photoaging in normal human dermal fibroblasts (NHDFs). The effects of BAE and AE on UVB-induced photoaging were tested by measuring the levels of reactive oxygen species, MMP-1, MMP-3, IL-6, type I procollagen, and TGF-β1 after UVB irradiation. We found that NHDF cells treated with BAE after UVB-irradiation suppressed MMP-1, MMP-3, and IL-6 levels compared to the AE-treated cells. Furthermore, BAE treatment elevated type I procollagen and TGF-β1 levels. Our results suggest that BAE may potentially protect the skin from UVB-induced damage more than AE.

IMPORTANCECertain patient groups, such as solid organ transplant recipients (SOTRs), have a significantly increased risk of developing skin cancers. The chemotherapeutic drug capecitabine has been used off label as a chemopreventive modality to suppress the development of precancerous skin lesions and squamous cell carcinomas (SCCs). OBJECTIVETo systematically review published studies on the use of capecitabine for the treatment and prevention of precancerous and cancerous skin lesions, with a focus on cutaneous SCC.EVIDENCE REVIEW For this systematic review, a literature search was performed using the PubMed and Embase databases in December 2019 for all articles published between January 1, 1998, and December 31, 2019, using the search term capecitabine paired with each of the following terms: actinic keratosis, actinic keratoses, squamous cell carcinoma, and basal cell carcinoma. Articles on the use of capecitabine for the treatment and prevention of actinic keratoses (AKs), SCCs, and basal cell carcinomas (BCCs) were selected for inclusion.FINDINGS Sixteen publications met the criteria for inclusion, with 8 case reports describing the inflammation of AKs in patients with solid organ cancer treated with capecitabine (2 patients with breast cancer and 6 patients with colorectal cancer). One case report and 1 case series of 4 patients investigated the use of capecitabine for the treatment of advanced or widespread cutaneous SCCs. A total of 6 publications (3 case reports and 3 case series) described the use of capecitabine to prevent development of SCCs in SOTRs. Of these case series, 2 studies found a significant reduction in SCC incidence rate during treatment with capecitabine compared with before treatment. Adverse effects, such as fatigue, nausea, vomiting, diarrhea, elevated creatinine level, hand-foot syndrome, hyperuricemia, weight loss, anemia, and cardiomyopathy, limited the duration of chemoprevention in several patients.CONCLUSIONS AND RELEVANCE Capecitabine treatment may be associated with a decrease in the incidence of SCCs in SOTRs. Capecitabine treatment may also be associated with a decrease in AK and BCC incidence. However, practitioners must weigh this benefit against the risk of adverse effects for each patient individually. Further investigation with a prospective clinical trial is warranted.

IntroductionReduced number and activities of epidermal stem cells are related to the features of photoaged skin. It was reported that conditioned media from various stem cell cultures are capable of improving the signs of cutaneous aging. This work was performed to establish epidermal progenitor cells derived from mesenchymal stem cells, and to evaluate the anti-aging efficacy of its conditioned media.MethodsEpidermal progenitor cell culture was established by differentiation from mesenchymal stem cells, and its conditioned medium (EPC-CM) was prepared. Normal human dermal fibroblasts were exposed to hydrogen peroxide and the protective effects of EPC-CM were investigated, monitoring intracellular reactive oxygen species (ROS), cellular defense enzymes, collagen biosynthesis, and mitogen-associated protein kinase (MAPK) signaling. Anti-aging efficacy of cosmetic essence (5% EPC-CM) was evaluated by a clinical test with 25 Korean women aged between 29 and 69.ResultsHydrogen peroxide hindered proliferation of fibroblasts and increased the levels of intracellular ROS. Pretreatment of EPC-CM protected fibroblasts from oxidative stress as shown by accelerated proliferation and reduced ROS generation. EPC-CM effectively prevented hydrogen peroxide-induced alterations of the activities, as well as mRNA and protein levels, of antioxidative enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase. Reduced type I collagen biosynthesis and stimulated phosphorylation of MAPK signaling proteins, induced by oxidative damage, were also prevented by EPC-CM. In clinical study, wrinkle, depression, and skin texture were improved by the topical application of a formulation containing 5% EPC-CM within 4 weeks.ConclusionEpidermal progenitor cell culture was established, and its conditioned medium was developed for anti-aging therapy. EPC-CM improved signs of skin aging in clinical study, possibly via activation of cellular the defense system, as supported by in vitro results.Electronic supplementary materialThe online version of this article (10.1007/s13555-018-0229-2) contains supplementary material, which is available to authorized users.

The dermal-epidermal junction (DEJ) provides a physical and biological interface between the epidermis and the dermis. In addition to providing a structural integrity, the DEJ also acts as a passageway for molecular transport. Based on the recently reported importance of the DEJ in skin aging, novel peptide derivatives have been tested for their effects on basement membrane (BM) protein expressions in cultured human epidermal keratinocytes. As a result, protein expressions of collagen XVII, laminin and nidogen were stimulated by the test peptide and peptides complex. Further ex vivo evaluation using excised human skin, confirmed that the topical application of the peptides complex significantly increased dermal collagen expression, as well as expressions of collagen XVII and laminin. Interestingly, while the origin of the laminin protein is epidermal keratinocytes, the immunohistochemical staining of skin showed that laminin was only detected in the uppermost layer of the dermis, which suggests a tight assembly of laminin protein onto the dermal side of the DEJ. These results suggest that a peptide complex could improve the structural properties of the DEJ through its ability to stimulate BM proteins. In order to evaluate the anti-wrinkle benefits of the peptide complex in vivo, a clinical study was performed on 22 healthy Asian female volunteers older than 40 years. As a result, significant improvements in skin wrinkles for all of the five sites were observed after two weeks, as assessed by skin topographic measurements. Collectively, these results demonstrate the anti-aging efficacy of the peptides complex.

We report deep ultraviolet (UVC) emitting core-shell-type AlGaN/AlN multiple quantum wells (MQWs) on the AlN nanorods which are prepared by catalyst/lithography free process. The MQWs are grown on AlN nanorods on a sapphire substrate by polarity-selective epitaxy and etching (PSEE) using hightemperature metal organic chemical vapor deposition. The AlN nanorods prepared through PSEE have a low dislocation density because edge dislocations are bent toward neighboring N-polar AlN domains. The core-shell-type MQWs grown on AlN nanorods have three crystallographic orientations, and the final shape of the grown structure is explained by a ball-and-stick model. The photoluminescence (PL) intensity of MQWs grown on AlN nanorods is approximately 40 times higher than that of MQWs simultaneously grown on a planar structure. This result can be explained by increased internal quantum efficiency, large active volume, and increase in light extraction efficiency based on the examination in this study. Among those effects, the increase of active volume on AlN nanorods is considered to be the main reason for the enhancement of the PL intensity.Aluminum nitride (AlN) based devices operating in the deep ultraviolet (UVC) regime (200-280 nm) have attracted considerable attention owing to their wide range of potential applications such as medical therapy, UV curing, biochemical sensing, water or air purification, and disinfection 1-3 . However, AlN based UVC devices still suffer from low quantum efficiency and output power. Although the external quantum efficiency of UVC light-emitting diodes (LEDs) has increased dramatically lately, most of the reported efficiency values remain at a few percent of the commercially required level. The low internal quantum efficiency due to a high dislocation density 4,5 and polarization coefficient 6,7 is the bottleneck for high-performance UVC applications.Such critical obstacles can be surmounted by introducing three-dimensional (3D) nanostructures because of their high stress relaxation, low dislocation density, increased active volume, and high extraction efficiency 8,9 . However, AlN based nanostructures for UVC light emitters have seldom been investigated because of the difficulty of using patterned masks. Selective area growth is strongly inhibited because Al atoms have very high sticking coefficient. Zhao et al. recently reported that these difficulties can be addressed by employing nitrogen (N)-polar Al(Ga)N nanowires grown on a Si substrate using a lithography-free process 10 . They developed self-organized AlN nanowire LEDs operating at 210 nm, the shortest wavelength ever reported for a nanostructure, and also reported an AlN nanowire laser diode fabricated by radio-frequency plasma-assisted molecular beam epitaxy (MBE) 9,11 . However, AlN or sapphire substrates are preferable for devices operating in the UVC regime because they are transparent to UVC emission. The polarity of the AlN layer can be controlled by varying the preflow conditions before AlN growth and the annealing temperature...