Abstract
The mechanism of carrier recombination in downsized μ-LED chips from 100 × 100 to 10 × 10 μm
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on emission performance was systemically investigated. All photolithography processes for ...defining the μ-LED pattern were achieved by using a laser direct writing technique. This maskless technology achieved the glass-mask-free process, which not only can improve the exposure accuracy but also save the development time. The multi-functional SiO
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film as a passivation layer successfully reduced the leakage current density of μ-LED chips compared with the μ-LED chips without passivation layer. As decreasing the chip size to 10 × 10 μm
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, the smallest chip size exhibited the highest ideality factor, which indicated the main carrier recombination at the high-defect-density zone in μ-LED chip leading to the decreased emission performance. The blue-shift phenomenon in the electroluminescence spectrum with decreasing the μ-LED chip size was due to the carrier screening effect and the band filling effect. The 10 × 10 μm
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μ-LED chip exhibited high EQE values in the high current density region with a less efficiency droop, and the max-EQE value was 18.8%. The luminance of 96 × 48 μ-LED array with the chip size of 20 × 20 μm
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exhibited a high value of 516 nits at the voltage of 3 V.
This nationwide population-based study aimed to examine the prospective association between near visual activities and incident myopia in Taiwanese children 7 to 12 years old over a 4-year follow-up ...period.
Prospective cohort design.
There were 1958 children aged 7 to 12 years from the Taiwan 2009 National Health Interview Survey who were linked to the 2009 through 2013 claims data from the National Health Insurance system.
Multivariable Cox proportional hazard models were used to estimate the associations between 3 types of near visual activities in sedentary posture, namely reading (< 0.5, 0.5-0.9, ≥1.0 hours per day h/d), use of computer, Internet, and games (<0.5, 0.5-0.9, ≥1.0 h/d), and "cram school" attendance (<0.5, 0.5-1.9, ≥2.0 h/d), and incident myopia.
Prevalent myopia was defined as those who had ≥2 ambulatory care claims (International Classification of Diseases code 367.1) in 2008-2009. Incident myopia was defined by those who had at least 2 ambulatory care claims (International Classification of Diseases code 367.1) during the 4-year follow-up period (2010-2013) after excluding prevalent cases.
Overall, 26.8% of children had myopia at baseline, and 27.7% of those without myopia at baseline developed incident myopia between 2010 and 2013. On average, they spent 0.68±0.86 h/d on computer/Internet use, 0.63±0.67 h/d on reading, and 2.78±3.53 h/d on cram school. The results showed that children attending cram schools ≥2 h/d (hazard ratio, 1.31; 95% confidence interval, 1.03-1.68) had a higher risk of incident myopia. The effects of these activities remained similar in sensitivity analyses.
Cram school attendance for ≥2 h/d may increase the risk of children's incident myopia. This effect may be due to increased near visual activity or reduced time outdoors.
We investigated the material properties of Cremonese soundboards using a wide range of spectroscopic, microscopic, and chemical techniques. We found similar types of spruce in Cremonese soundboards ...as in modern instruments, but Cremonese spruces exhibit unnatural elemental compositions and oxidation patterns that suggest artificial manipulation. Combining analytical data and historical information, we may deduce the minerals being added and their potential functions—borax and metal sulfates for fungal suppression, table salt for moisture control, alum for molecular crosslinking, and potash or quicklime for alkaline treatment. The overall purpose may have been wood preservation or acoustic tuning. Hemicellulose fragmentation and altered cellulose nanostructures are observed in heavily treated Stradivari specimens, which show diminished second‐harmonic generation signals. Guarneri's practice of crosslinking wood fibers via aluminum coordination may also affect mechanical and acoustic properties. Our data suggest that old masters undertook materials engineering experiments to produce soundboards with unique properties.
ICP‐MS is used to identify the unique mineral recipe used by Antonio Stradivari to treat his spruce wood, the material for the violin top plate. Chemical manipulation led to hemicellulose fragmentation and cellulose rearrangement. Incorporating engineered wood may contribute to the unique tonal qualities of these acclaimed instruments.
Patients with advanced-stage non-small-cell lung cancer (NSCLC) are susceptible to malnutrition and develop folate deficiency (FD). We previously found that folate deprivation induces drug resistance ...in hepatocellular carcinoma; here, we assessed whether disrupted cytoplasmic folate metabolism could mimic FD-induced metastasis and affect the sensitivity of NSCLC cells to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). We examined whether cytosolic folate metabolism in NSCLC cells was disrupted by FD or the folate metabolism blocker pemetrexed for 1–4 weeks. Our results revealed an increase in NF-κB overexpression–mediated epithelial-mesenchymal transition biomarkers: N-cadherin, vimentin, matrix metalloproteinases (MMPs), SOX9, and SLUG. This finding suggests that the disruption of folate metabolism can drastically enhance the metastatic properties of NSCLC cells. Cytosolic FD also affected EGFR-TKI cytotoxicity toward NSCLC cells. Because SLUG and N-cadherin are resistance effectors against gefitinib, the effects of SLUG knockdown in folate antagonist–treated CL1-0 cells were evaluated. SLUG knockdown prevented SLUG/NF-κB/SOX9-mediated invasiveness and erlotinib resistance acquisition and significantly reduced pemetrexed-induced gelatinase activity and MMP gene expression. To summarize, our data reveal two unprecedented adverse effects of folate metabolism disruption in NSCLC cells. Thus, the folic acid status of patients with NSCLC under treatment can considerably influence their prognosis.
The complex‐oxide materials are multifunctional materials, which have wide applications to the semiconductor and microelectronic fields. The ZnGa2O4 having a wide bandgap of 5.1 eV is one of the ...promising materials for deep‐ultraviolet photodetector (PD) applications. The ZnGa2O4 films are deposited by using conventional radio‐frequency magnetron sputtering which is extensively employed in the industry. However, the as‐deposited ZnGa2O4 films show the disordered nanocrystalline structure, resulting in the relatively poor performance. Since the Zn atoms can diffuse out of the film structure during the annealing, the ZnGa2O4 material is difficult to get the single‐crystalline structure by using the sputtering method. Here, the solid‐phase epitaxy method is used for crystallizing the ZnGa2O4 structure via rapid thermal annealing process. The disordered crystal grains as incubated seeds are obtained in the as‐deposited ZnGa2O4 film at the substrate temperature of 400 °C. Further annealing under the temperature of 700 °C in 1 min, the ZnGa2O4 film structure approaches the quasi‐single‐crystalline ZnGa2O4 structure, which is evidenced by checking the transmission electron microscopy. The responsivity of annealed ZnGa2O4 PDs can reach 2.53 A W−1 (at 240 nm and 5 V), which shows a relative enhancement of 256% compared with the as‐deposited ZnGa2O4 PDs.
The complex‐oxide ZnGa2O4 films are deposited by radio‐frequency magnetron sputtering for deep‐ultraviolet photodetector applications. The as‐deposited ZnGa2O4 films with disordered nanocrystalline structure are improved by solid‐phase epitaxy via rapid‐thermal annealing, resulting in achieving the quasi‐single‐crystalline structure. The improved responsivity of ZnGa2O4 photodetector can reach 2.53 A W−1 (at 240 nm and 5 V), which shows a relative enhancement of 256%.
Aluminum gallium oxide (AGO) films were deposited on c-plane sapphire by co-sputtering of Al and Ga2O3 targets at a substrate temperature of 600 °C, and then annealed at 900 °C to enhance their ...crystal quality. The effect of DC power (0, 5, 10, 30, 50 and 70 W) for Al target on the structural, optical and compositional characteristics of AGO films were investigated. After annealing, the films prepared at the DC powers of 0–50 W for Al target all exhibited the single crystalline structure with the (−201) plane family. The annealed film grown at the DC power of 10 W possessed the highest crystal quality than the others. With increasing the DC power from 0 to 70 W, the Al composition of AGO film increased from 0 to 6.08 at.%, while its bandgap increased from 4.89 to 5.19 eV. X-ray photoelectron spectroscopy studies indicate the intensity of Ga 2p3/2 peak (1117.9 eV) for the AGO film decreases, whereas the intensity of Al 2p peak (74.6 eV) increases with increasing the DC power. The metal-semiconductor-metal photodetector with the annealed AGO film deposited at the DC power of 10 W possesses the largest photocurrent of 5.7 × 10−9 A and the on/off current ratio (Ion/Ioff) of 1.5 × 104 (@2 V and 230 nm). The better optoelectronic performance of this device was attributed that the AGO film (DC power: 10 W) had a higher crystal quality, the O/(Al+Ga) ratio close to the optimum value of 1.5. Our results present the AGO films can be successfully prepared via sputtering technique, which are highly potential for deep-ultraviolet applications.
•The effect of sputtering power on the AGO films' properties was investigated.•The bandgap values of these sputtered AGO films can reach to 4.89–5.19 eV.•XPS reveals the Ga 2p3/2 peak becomes weak by increasing the DC power of Al target.•Meanwhile, the Al 2p peak becomes strong with increasing the DC power of Al target.•AGO film (DC power: 10 W) has higher crystal quality and optimum O/(Al+Ga) ratio.
The enhanced light output efficiency of passive-matrix micro light-emitting-diode (LED) display was achieved by employing the tapered sidewalls and distributed-Bragg-reflector (DBR) passivation ...structure. The oblique angles at the bottom of multi-quantum wall and n-GaN are 48.9° and 21.8°, which can favor the planarization structure of pixel interconnection. As increasing the number of DBR (SiO 2 /TiO 2 ) stacking from 3.5 to 5.5 pairs, the reflectance increased obviously from 81.4% to 98.0% at the wavelength of 450 nm. As the micro-LED display with a multi-function DBR structure, the output power of 1.07 mW under 1 mA, the external-quantum efficiency of 42% under 0.2 mA, and the luminance of 435 nits were obtained.
Mitochondria (MITO) and peroxisomes (PEXO) are the major organelles involved in the oxidative metabolism of cells, but detailed examination of their dynamics and functional adaptations during ...skeletal muscle (SKM) development (myogenesis) is still lacking. In this study, we found that during myogenesis, MITO DNA, ROS level, and redox ratio increased in myotubes, but the membrane potential (Δψm) and ATP content reduced, implying that the MITO efficiency might reduce during myogenesis. The PEXO number and density both increased during myogenesis, which probably resulted from the accumulation and increased biogenesis of PEXO. The expression of PEXO biogenesis factors was induced during myogenesis in vitro and in utero, and their promoters were also activated by MyoD. Knockdown of the biogenesis factors
repressed not only the PEXO density and functions but also the levels of MITO genes and functions, suggesting a close coupling between PEXO biogenesis and MITO functions. Surprisingly,
knockdown by the CRISPRi system repressed myogenic differentiation, indicating critical involvement of PEXO biogenesis in myogenesis. Taken together, these observations suggest that the dynamics and functions of both MITO and PEXO are coupled with each other and with the metabolic changes that occur during myogenesis, and these metabolic couplings are critical to myogenesis.
The aim of this study was to identify novel microRNAs related to obstructive sleep apnea (OSA) characterized by intermittent hypoxia with re-oxygenation (IHR) injury. Illumina MiSeq was used to ...identify OSA-associated microRNAs, which were validated in an independent cohort. The interaction between candidate microRNA and target genes was detected in the human THP-1, HUVEC, and SH-SY5Y cell lines. Next-generation sequencing analysis identified 22 differentially expressed miRs (12 up-regulated and 10 down-regulated) in OSA patients. Enriched predicted target pathways included senescence, adherens junction, and AGE-RAGE/TNF-α/HIF-1α signaling. In the validation cohort, miR-92b-3p and miR-15b-5p gene expressions were decreased in OSA patients, and negatively correlated with an apnea hypopnea index. PTGS1 (COX1) gene expression was increased in OSA patients, especially in those with depression. Transfection with miR-15b-5p/miR-92b-3p mimic in vitro reversed IHR-induced early apoptosis, reactive oxygen species production, MAOA hyperactivity, and up-regulations of their predicted target genes, including PTGS1, ADRB1, GABRB2, GARG1, LEP, TNFSF13B, VEGFA, and CXCL5. The luciferase assay revealed the suppressed PTGS1 expression by miR-92b-3p. Down-regulated miR-15b-5p/miR-92b-3p in OSA patients could contribute to IHR-induced oxidative stress and MAOA hyperactivity through the eicosanoid inflammatory pathway via directly targeting PTGS1-NF-κB-SP1 signaling. Over-expression of the miR-15b-5p/miR-92b-3p may be a new therapeutic strategy for OSA-related depression.
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