Abstract
Field-induced ionic motions in all-inorganic CsPbBr
3
perovskite quantum dots (QDs) strongly dictate not only their electro-optical characteristics but also the ultimate optoelectronic ...device performance. Here, we show that the functionality of a single Ag/CsPbBr
3
/ITO device can be actively switched on a sub-millisecond scale from a resistive random-access memory (RRAM) to a light-emitting electrochemical cell (LEC), or vice versa, by simply modulating its bias polarity. We then realize for the first time a fast, all-perovskite light-emitting memory (LEM) operating at 5 kHz by pairing such two identical devices in series, in which one functions as an RRAM to electrically read the encoded data while the other simultaneously as an LEC for a parallel, non-contact optical reading. We further show that the digital status of the LEM can be perceived in real time from its emission color. Our work opens up a completely new horizon for more advanced all-inorganic perovskite optoelectronic technologies.
Due to the scarcity of circular polarization light sources, linear-to-circular polarization conversion is required to generate circularly polarized light for a variety of applications. Despite ...significant past efforts, broadband linear-to-circular polarization conversion remains elusive particularly in the terahertz and midinfrared frequency ranges. Here we propose a novel mechanism based on coupled mode theory, and experimentally demonstrate at terahertz frequencies that highly efficient (power conversion efficiency approaching unity) and ultrabroadband (fractional bandwidth up to 80%) linear-to-circular polarization conversion can be accomplished by the judicious design of birefringent metasurfaces. The underlying mechanism operates in the frequency range between well separated resonances, and relies upon the phase response of these resonances away from the resonant frequencies, as well as the balance of the resonant and nonresonant channels. This mechanism is applicable for any operating frequencies from microwave to visible. The present Letter potentially opens a wide range of opportunities in wireless communications, spectroscopy, and emergent quantum materials research where circularly polarized light is desired.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Abstract
The processes leading to the rapid intensification (RI) of Typhoon Megi (2010) are explored with a convection-permitting full-physics model and a sensitivity experiment using a different ...microphysical scheme. It is found that the temporary active convection, gradually strengthened primary circulation, and a warm core developing at midlevels tend to serve as precursors to RI. The potential vorticity (PV) budget and Sawyer–Eliassen model are utilized to examine the causes and effects of those precursors. Results show that the secondary circulation, triggered by the latent heat associated with active convection, acts to strengthen the mid- to upper-level primary circulation by transporting the larger momentum toward the upper layers. The increased inertial stability at mid- to upper levels not only increases the heating efficiency but also prevents the warm-core structure from being disrupted by the ventilation effect. The warming above 5 km effectively lowers the surface pressure.
It is identified that the strong secondary circulation helps to accomplish the midlevel warming within the eye. The results based on potential temperature (θ) budget suggest that the mean subsidence associated with detrainment of active convection is the major process contributing to the formation of a midlevel warm core. On the possible causes triggering the inner-core active convection, it is suggested that the gradually increased vortex-scale surface enthalpy flux has a leading role in the development of vigorous convection. The results also highlight the potentially dominant role of weak to moderate convection in the onset of RI, while the convective bursts play a supporting role. Based on the aforementioned analyses, a schematic diagram is shown to describe the plausible path leading to RI.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Wharton's jelly of the umbilical cord contains mucoid connective tissue and fibroblast‐like cells. Using flow cytometric analysis, we found that mesenchymal cells isolated from the umbilical cord ...express matrix receptors (CD44, CD105) and integrin markers (CD29, CD51) but not hematopoietic lineage markers (CD34, CD45). Interestingly, these cells also express significant amounts of mesenchymal stem cell markers (SH2, SH3). We therefore investigated the potential of these cells to differentiate into cardiomyocytes by treating them with 5‐azacytidine or by culturing them in cardiomyocyte‐conditioned medium and found that both sets of conditions resulted in the expression of cardiomyocyte markers, namely N‐cadherin and cardiac troponin I. We also showed that these cells have multilineage potential and that, under suitable culture conditions, are able to differentiate into cells of the adipogenic and osteogenic lineages. These findings may have a significant impact on studies of early human cardiac differentiation, functional genomics, pharmacological testing, cell therapy, and tissue engineering by helping to eliminate worrying ethical and technical issues.
Paranasal sinusitis is widespread and can lead to orbital complications, blindness, and death. However, the correlation between ophthalmological findings and disease staging remains unclear. This ...study aimed to investigate the staging, acute ophthalmological manifestations, diagnosis, management, and outcomes of orbital complications of paranasal sinusitis during a 27-year period.
We retrospectively reviewed the medical records of all patients with orbital complications of paranasal sinusitis hospitalized at the National Cheng Kung University Hospital, a medical center in Taiwan during 1988-2015. Sex, age, symptoms, history, ophthalmological findings, laboratory and imaging findings, treatments, and outcomes were analyzed by staging.
Eighty-three patients aged 9 days to 80 years had stage I (preseptal cellulitis, n = 39 patients), II (postseptal orbital cellulitis, n = 8), III (subperiosteal abscess, n = 16), IV (orbital abscess, n = 8), or V (intracranial involvement, n = 12) complications. Peak incidences occurred in patients aged 0-19 and 60-69 years. Chronic sinusitis and diabetes mellitus were common preexisting diseases. Extraocular movement limitation and proptosis predicted postseptal (stage II or more) involvement. The likelihood of elevated intraocular pressure increased with stage. Reduced visual acuity and presence of relative afferent pupillary defect indicated consideration of magnetic resonance imaging to investigate possible intracranial extension. Ipsilateral maxillary (81.7%) and ethmoidal (75.6%) sinuses were the most common sources of infection, and the most frequently implicated pathogens were coagulase-negative Staphylococcus spp. (25.3%) and Staphylococcus aureus (20.5%). All patients received intravenous antimicrobial therapy (multi-drug therapy in 88.0%), and 55.4% underwent surgery, most commonly endoscopic sinus surgery. One (1.2%) diabetic man with stage V complications died of fungal sinusitis with intracranial invasion. Five (6.0%) patients, all stage V, lost vision despite intensive treatment. The average length of hospital stay was 13.8 days (range 2-72 days), and significantly longer stays were associated with stages II-V as compared to stage I.
Orbital infection originating from paranasal sinusitis can cause vision loss and death due to intracranial extension. Acute ophthalmological findings predict staging and prognosis. Cooperative consultation between ophthalmologists, otorhinolaryngologists, and neurologists is essential. Urgent diagnostic studies and aggressive antimicrobial therapy are indicated, and surgery should be considered.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Conventional methods to prepare large‐area graphene for transparent conducting electrodes involve the wet etching of the metal catalyst and the transfer of the graphene film, which can degrade the ...film through the creation of wrinkles, cracks, or tears. The resulting films may also be obscured by residual metal impurities and polymer contaminants. Here, it is shown that direct growth of large‐area flat nanographene films on silica can be achieved at low temperature (400 °C) by chemical vapor deposition without the use of metal catalysts. Raman spectroscopy and TEM confirm the formation of a hexagonal atomic network of sp2‐bonded carbon with a domain size of about 3–5 nm. Further spectroscopic analysis reveals the formation of SiC between the nanographene and SiO2, indicating that SiC acts as a catalyst. The optical transmittance of the graphene films is comparable with transferred CVD graphene grown on Cu foils. Despite the fact that the electrical conductivity is an order of magnitude lower than CVD graphene grown on metals, the sheet resistance remains 1–2 orders of magnitude better than well‐reduced graphene oxides.
Direct deposition of nanographene on oxides is achieved using an electron cyclotron resonance chemical vapor deposition (ECR‐CVD) method. Wet etching and transfer are thus unnecessary, leaving the nanographene films free from metal impurities or polymer contamination. Spectroscopic analysis shows that a SiC layer appears at the interface between nanographene and SiO2, highlighting the importance of carbide in the growth of graphene using oxides as catalysts.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The risk and outcomes of diabetes in patients with epilepsy remains unclear. We evaluated these risks using an epilepsy cohort analysis and a diabetes admission analysis. In the epilepsy cohort ...analysis, we identified 2854 patients with newly diagnosed epilepsy in 2000-2008 from the research data of National Health Insurance in Taiwan. Using Propensity-score matching by sociodemographic factors and medical conditions, we selected 22,832 people without epilepsy as a non-exposed cohort for comparison. Follow-up events of diabetes from January 1, 2000 until December 31, 2013 were ascertained from medical claims. The adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of diabetes associated with epilepsy were calculated using multiple Cox proportional hazard models. In the diabetes admission analysis, we identified 92,438 hospitalized diabetes patients, 930 of whom had a history of epilepsy. Adjusted odds ratios (ORs) and 95% CIs of adverse events after diabetes associated with previous epilepsy were calculated using multiple logistic regressions. The adjusted HR of diabetes in the cohort with epilepsy was 1.31 (95% CI 1.14-1.50) compared to the non-epilepsy cohort. Previous epilepsy was associated with post-diabetes adverse events, such as pneumonia (OR 1.68, 95% CI 1.37-2.07), urinary tract infection (OR 1.83, 95% CI 1.55-2.16), and septicemia (OR 1.34, 95% CI 1.09-1.65). In conclusion, epilepsy was associated with higher risk of diabetes and adverse post-diabetes outcomes. Diabetes prevention and attention to post-diabetes adverse events are needed for this susceptible population.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Emerging data suggest immune checkpoint inhibitors have reduced efficacy in heavily pretreated triple-negative breast cancers (TNBC), but underlying mechanisms are poorly understood. To better ...understand the phenotypic evolution of TNBCs, we studied the genomic and transcriptomic profiles of paired tumors from patients with TNBC.
We collected paired primary and metastatic TNBC specimens from 43 patients and performed targeted exome sequencing and whole-transcriptome sequencing. From these efforts, we ascertained somatic mutation profiles, tumor mutational burden (TMB), TNBC molecular subtypes, and immune-related gene expression patterns. Stromal tumor-infiltrating lymphocytes (stromal TIL), recurrence-free survival, and overall survival were also analyzed.
We observed a typical TNBC mutational landscape with minimal shifts in copy number or TMB over time. However, there were notable TNBC molecular subtype shifts, including increases in the Lehmann/Pietenpol-defined basal-like 1 (BL1, 11.4%-22.6%) and mesenchymal (M, 11.4%-22.6%) phenotypes, and a decrease in the immunomodulatory phenotype (IM, 31.4%-3.2%). The Burstein-defined basal-like immune-activated phenotype was also decreased (BLIA, 42.2%-17.2%). Among downregulated genes from metastases, we saw enrichment of immune-related Kyoto Encyclopedia of Genes and Genomes pathways and gene ontology (GO) terms, and decreased expression of immunomodulatory gene signatures (
< 0.03) and percent stromal TILs (
= 0.03). There was no clear association between stromal TILs and survival.
We observed few mutational shifts, but largely consistent transcriptomic shifts in longitudinally paired TNBCs. Transcriptomic and IHC analyses revealed significantly reduced immune-activating gene expression signatures and TILs in recurrent TNBCs. These data may explain the observed lack of efficacy of immunotherapeutic agents in heavily pretreated TNBCs. Further studies are ongoing to better understand these initial observations.
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The temperature dependences of the threshold current and slope efficiency, as represented by their respective characteristic temperature coefficients T0 and T1, are discussed for quantum cascade ...lasers (QCLs) emitting in the 3.0-3.8 μm, 3.9-5.0 μm, 8-10 μm, and 12-16 μm wavelength ranges. Carrier-leakage mechanisms are treated with emphasis on shunt-type leakage within active regions (ARs); the dominant leakage path in state-of-the-art devices. Carrier-leakage suppression, best evidenced by the T1 value, is shown to have been the key to effectively doubling the room-temperature pulsed and continuous-wave (CW) wallplug efficiencies for 4.5-5.0 μm emitting QCLs. By employing deep-well and/or tapered-active (TA)-type AR designs, for carrier-leakage suppression, T0 values as high as 278 K at λ = 4.8 μm and 242 K at λ = 8.4 μm have been achieved for devices of moderately high injector doping, as required for watt-range room-temperature CW operation. Similarly, TA-type QCLs have led to record-high T1 values: 797 K at λ = 4.8 μm, and 561 K at λ = 8.8 μm, for low-threshold (~1.6 kA cm−2) devices at room temperature. Step-taper TA (STA) AR designs for 8.4 and 8.8 μm emitting QCLs have resulted in both carrier-leakage suppression as well as fast and efficient carrier extraction. That, in turn, led to internal-differential-efficiency values in the 85-90% range; that is, 30-40% higher than for any previously reported 7-10 μm emitting QCLs. We further show that 4.6 μm emitting STA-type devices hold the potential for room-temperature CW wallplug efficiency values in excess of 27%. Should the internal differential efficiency reach theoretical limits (87-89%) at λ = 4.6 μm, single-facet, room-temperature CW wallplug efficiency values in excess of 40% become possible.
Both the size of the older population and the use of complementary and alternative medicine are increasing worldwide. This study evaluated the long-term trend in utilization of traditional Chinese ...medicine (TCM) and associated factors among older people in Taiwan.
Using the database of population-based interview surveys, we evaluated the one-month prevalence of TCM use among 13,945 older people aged over 65 years from 2001-2017. The sociodemographic status and medical comorbidities of older people who did and did not use TCM were compared by calculating adjusted odds ratios (ORs) and 95% confidence intervals (CIs) in the multiple logistic regressions.
The one-month prevalence of TCM use increased from 5.5% in 2001 to 9.1% in 2017 among older people in Taiwan. Overall, 7.3% of older people had used TCM within the previous month. People with a history of heart disease (OR 1.62, 95% CI 1.24-2.12), use of folk therapy (OR 3.16, 95% CI 2.00-4.99), and purchase of non-prescribed Chinese herbal medicine (OR 2.08, 95% CI 1.48-2.91) were more likely to use TCM than the comparison group. However, age ≥80 years (OR 0.48, 95% CI 0.31-0.72) and previous hospitalization (OR 0.59, 95% CI 0.41-0.85) were associated with the reduced use of TCM.
From 2001-2017, the use of TCM increased in the older population in Taiwan. The use of folk medicine and purchase of non-prescribed Chinese herbal medicine were significant predictors for the use of TCM.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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