Large-Area Growth of Ferroelectric 2D γ-In2 Se3 Semiconductor by Spray Pyrolysis for Next-Generation Memory

In2 Se3 , 2D ferroelectric-semiconductor, is a promising candidate for next-generation memory device because of its outstanding electrical properties. However, the large-area manufacturing of In2 Se3 is still a big challenge. In this work, spray pyrolysis technique is introduced for the growth of large-area In2 Se3 thin film. A polycrystalline γ-In2 Se3 layer can be grown on 15 cm × 15 cm glasss at the substrate temperature of 275 °C. The In2 Se3 ferroelectric-semiconductor field effect transistor (FeS-FET) on glass substrate demonstrates a large hysteresis window of 40.3 V at the ±40 V of gate voltage sweep and excellent uniformity. The FeS-FET exhibits an electron field effect mobility of 0.97 cm2 V-1 s-1 and an on/off current ratio of >107 in the transfer curves. The memory behavior of the large-area, In2 Se3 FeS-FETs for next-generation memory is demonstrated.

Influence of NF3 Plasma-Treated HfO2 Gate Insulator Surface on Tin Oxide Thin-Film Transistors

We studied the impact of NF3 plasma treatment on the HfO2 gate insulator of amorphous tin oxide (a-SnOx) thin-film transistors (TFTs). The plasma treatment was for 0, 10, or 30 s. The HfO2 insulator demonstrated a slightly higher breakdown voltage, whereas the capacitance value remained almost constant (~150 nF/cm2). The linear mobility slightly increased from ~30 to ~35 cm2/Vs when the treatment time increased from 0 to 10 s, whereas a 30 s-treated TFT demonstrated a decreased mobility of ~15 cm2/Vs. The subthreshold swing and the threshold voltage remained in the 100-120 mV/dec. range and near 0 V, respectively. The hysteresis dramatically decreased from ~0.5 V to 0 V when a 10 s treatment was applied, and the 10 s-treated TFT demonstrated the best stability under high current stress (HCS) of 100 μA. The analysis of the tin oxide thin film crystallinity and oxygen environment demonstrated that the a-SnOx remained amorphous, whereas more metal-oxygen bonds were formed with a 10 s NF3 plasma treatment. We also demonstrate that the density of states (DOS) significantly decreased in the 10 s-treated TFT compared to the other conditions. The stability under HCS was attributed to the HfO2/a-SnOx interface quality.

Second Data Release from the European Pulsar Timing Array: Challenging the Ultralight Dark Matter Paradigm

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses 10^{-24.0}  eV≲m≲10^{-23.3}  eV cannot constitute 100% of the measured local dark matter density, but can have at most local density ρ≲0.3  GeV/cm^{3}.

Multifunctional Crystalline InGaSnO Phototransistor Exhibiting Photosensing and Photosynaptic Behavior Using Oxygen Vacancy Engineering

A multifunctional optoelectronic device implementing photodetector, photosynapse, and photomemory is of increasing attention for neuromorphic system. This enables multiple devices to be replaced with a single device, which simplifies the structure of complex, highly integrated electronics. Here, a multifunctional c-axis-aligned crystalline indium gallium tin oxide thin-film transistor (TFT) optoelectronic device is demonstrated. The photodetecting and photosynaptic behaviors could be demonstrated by tuning of gate pulse. The device shows a high responsivity of 1.1 × 106  A W-1 to blue light (467 nm) and cutoff frequency (f-3dB ) of 2400 Hz exhibiting high frequency switching using a gate reset pulse. It is possible to implement photosynaptic behavior using persistent photoconductivity effect by applying a gate bias to make the TFT depletion mode. When potentiation and depression of synaptic weight are implemented with light pulse and gate voltage pulse, respectively, 64-state potentiation-depression curves are demonstrated with excellent nonlinearity of 1.13 and 2.03, respectively. When an artificial neural network is constructed with this device for the Modified National Institute of Standards and Technology training pattern recognition simulation, it shows a high pattern recognition accuracy of 90.4%.

Low-Temperature Solution-Processed HfZrO Gate Insulator for High-Performance of Flexible LaZnO Thin-Film Transistor

Metal-oxide-semiconductor (MOS)-based thin-film transistors (TFTs) are gaining significant attention in the field of flexible electronics due to their desirable electrical properties, such as high field-effect mobility (μFE), lower IOFF, and excellent stability under bias stress. TFTs have widespread applications, such as printed electronics, flexible displays, smart cards, image sensors, virtual reality (VR) and augmented reality (AR), and the Internet of Things (IoT) devices. In this study, we approach using a low-temperature solution-processed hafnium zirconium oxide (HfZrOx) gate insulator (GI) to improve the performance of lanthanum zinc oxide (LaZnO) TFTs. For the optimization of HfZrO GI, HfZrO films were annealed at 200, 250, and 300 °C. The optimized HfZrO-250 °C GI-based LaZnO TFT shows the μFE of 19.06 cm2V-1s-1, threshold voltage (VTH) of 1.98 V, hysteresis voltage (VH) of 0 V, subthreshold swing (SS) of 256 mV/dec, and ION/IOFF of ~108. The flexible LaZnO TFT with HfZrO-250 °C GI exhibits negligible ΔVTH of 0.25 V under positive-bias-temperature stress (PBTS). The flexible hysteresis-free LaZnO TFTs with HfZrO-250 °C can be widely used for flexible electronics. These enhancements were attributed to the smooth surface morphology and reduced defect density achieved with the HfZrO gate insulator. Therefore, the HfZrO/LaZnO approach holds great promise for next-generation MOS TFTs for flexible electronics.

As-Grown Crystalline InGaZnO by Spray Pyrolysis on a Flexible Substrate for a Thin-Film Transistor with Excellent Stability

The development of low-cost, high-mobility oxide thin-film transistors (TFTs) with excellent stability is of increasing interest. The coplanar oxide TFTs can be used for high-speed, large-area, and high-resolution displays. Here, we report highly oriented, as-grown crystalline InGaZnO (c-IGZO) with very low oxygen vacancy defects using spray pyrolysis at the substrate temperature of 425 °C. The c-IGZO exhibits a highly oriented, c-axis aligned crystal perpendicular to the substrate with a high mass density of 6.73 g cm-3 without any disordered incubation layer. Its resistivity can be decreased to 0.42 mΩ cm by NF3 plasma doping, which is essential to achieving high-performance coplanar TFT. We have demonstrated the application of this material to high-performance flexible TFTs. The self-aligned, coplanar c-IGZO TFTs on the polyimide substrate exhibit an average field-effect mobility of 39.60 cm2 V-1 s-1, threshold voltage of -1.00 V, subthreshold swing of 0.21 V dec-1, and on/off current ratio over 108. The ring oscillator and gate driver made of the c-IGZO TFTs exhibit a propagation delay of 8.77 ns/stage and rising/falling times of 648/564 ns, respectively. Therefore, the as-grown c-IGZO by spray pyrolysis has the potential to be utilized as a new oxide semiconductor for the production of low-cost, flexible TFT electronics.

Retraction: High‐Efficiency, Blue, Green, and Near‐Infrared Light‐Emitting Diodes Based on Triple Cation Perovskite

Adv. Optical Mater. 2017, 5, 1600920

https://doi.org/10.1002/adom.201600920

The above article, published online on 2 February 2017 in Wiley Online Library (https://doi.org/10.1002/adom.201600920), has been retracted by agreement between the authors, the journal's Editor‐in‐Chief, Anja Wecker, and Wiley‐VCH GmbH. An initial concern on atypical noise patterns in Figure 3 and Figure S1 was raised by third parties. An expert analysis of the requested raw data has revealed clear signatures of data manipulation. As a result, the conclusions of this study are considered not reliable.

Anticoagulant treatment patterns and thromboembolic events by tumor type among patients with VTE and cancer

Background

Patients with venous thromboembolism (VTE) and cancer are at higher risk of adverse outcomes (mortality, recurrent VTE etc.) versus patients with cancer alone; as such, clinical guidelines recommend anticoagulant treatment for patients with VTE and cancer. There is limited real world data about how anticoagulant treatment and thromboembolic outcomes differ by tumor type in patients with VTE and cancer. Understanding such differences may help identify appropriate anticoagulant treatment for specific tumor types.

Purpose

To describe anticoagulant treatment patterns and thromboembolic outcomes by tumor type among patients with VTE and cancer.

Methods

Patients with VTE and cancer age ≥65 were identified from the Surveillance, Epidemiology and End Results (SEER) Medicare database from 1/1/2014–12/31/2019. Patients were required to be enrolled for ≥6-months prior to their first VTE diagnosis (index) and without evidence of other conditions requiring anticoagulant (i.e., atrial fibrillation) prior to index. Cancer status and tumor type were identified from SEER or Medicare database in the 6-months prior through 30-days post VTE. This analysis focused on the following specific tumor types: high risk (brain, pancreas, and stomach) and common tumor types (breast, and prostate). Patients treated with an anticoagulant within 30-days after index were included in the final population. Major bleeding (MB) and recurrent VTE events were measured during follow-up (index date through earliest of disenrollment, death or 12/31/2019).

Results

A total of 3,546 anticoagulated patients with VTE and cancer of interest met all study criteria (breast [n=1,197], prostate [n=849], pancreatic [n=995], brain [n=248] and stomach [n=257] cancer). Patient mean age ranged from 73 (brain) to 76 (stomach) at index. Anticoagulant treatment patterns varied by tumor type (Figure 1). LMWH was more likely to be used in the 3 high risk tumor types whereas apixaban and rivaroxaban were more likely to be used in the 2 common tumor types. The incidence rate of recurrent VTE and major bleeding events also varied among different tumor types: ranging from 1.4 (breast) to 6.4 (pancreatic) per 100 person-years for recurrent VTE and from 4.3 (prostate) to 15.1 (pancreatic) per 100 person-years for major bleeding (Figure 2).

Conclusion

There are notable variations in anticoagulant treatment patters and the risks of major bleeding and recurrent VTE events by tumor type among patients with VTE and cancer. Further research is needed to understand which anticoagulant treatment option is more appropriate for VTE patients with specific tumor type.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Pfizer Inc. and Bristol Myers Squibb Company

Photonic nanostructures mimicking floral epidermis for perovskite solar cells

Here, we report photonic nanostructures replicated from the adaxial epidermis of flower petals onto light-polymerized coatings using low-cost nanoimprint lithography at ambient temperature. These multifunctional nanocoatings are applied to confer enhanced light trapping, water repellence, and UV light and environmental moisture protection features in perovskite solar cells. The former feature helps attain a maximum power conversion efficiency of 24.61% (21.01% for the reference cell) without any additional device optimization. Added to these merits, the nanocoatings also enable stable operation under AM 1.5G and UV light continuous illumination or in real-world conditions. Our engineering approach provides a simple way to produce multifunctional nanocoatings optimized by nature's wisdom.

Nano-Scale Ga2O3 Interface Engineering for High-Performance of ZnO-Based Thin-Film Transistors

Thin-film transistor (TFT) is a essential device for future electronics driving the next level of digital transformation. The development of metal-oxide-semiconductor (MOS) TFTs is considered one of the most advantageous devices for next-generation, large-area flexible electronics. This study demonstrates the systematic study of the amorphous gallium oxide (a-Ga₂O₃) and its application to nanocrystalline ZnO TFTs. The TFT with a-Ga₂O₃/c-ZnO-stack channel exhibits a field-effect mobility of ∼41 cm² V^-1 s^-1 and excellent stability under positive-bias-temperature stress. The a-Ga₂O₃/c-ZnO-stack TFT on polyimide (PI) substrate exhibits a negligible threshold voltage shift upon 100k bending cycles with a radius of 3 mm and is very stable under environmental test. The smooth morphology with tiny grains of ∼12 nm diameter with fewer grain boundary states improves the charge transport in Ga₂O₃/ZnO-stack TFT. The existence of amorphous a-Ga₂O₃ in between very thin ZnO layers helps to enhance the heterointerfaces and reduce the defect density in Ga₂O₃/ZnO interface. Therefore, integrating a-Ga₂O₃ in the ZnO channel in stacked TFT can increase mobility and enhance stability for next-generation flexible TFT electronics.

Polycrystalline InGaO Thin-Film Transistors with Coplanar Structure Exhibiting Average Mobility of ≈78 cm2 V-1 s-1 and Excellent Stability for Replacing Current Poly-Si Thin-Film Transistors for Organic Light-Emitting Diode Displays

Highly ordered polycrystalline indium gallium oxide (PC-IGO) film is obtained by the crystallization of room temperature sputtered amorphous IGO on a hot plate at 350 °C for 1 h and then annealed for 1 h in an N₂ O environment. A high-density PC-IGO of ≈7.15 g cm^-3 with reduced oxygen vacancy (≈14.83%) and hydroxyl (OH) related defects (≈10.96%) has been obtained by N₂ O annealing. Self-aligned coplanar thin-film transistor (TFT) with the PC-IGO exhibits the average saturation mobility of 78.73 cm² V^-1 s^-1 , threshold voltage of -1.07 V, subthreshold swing of 0.147 V dec^-1 , and the on/off current ratio of over 10⁸ . The TFTs show excellent stability under bias-temperature stress with a negligible threshold voltage shift (ΔV_TH ) of + 0.1 and -0.1 V for the positive and negative bias stresses, respectively. The TFTs exhibit very stable environmental stability when the TFTs are stored under high humidity (85%) and a high temperature (85 °C) for 2 days. The ring oscillator and the gate driver mode of the PC-IGO TFTs exhibit the propagation delay of 7.44 ns/stage with rising/falling times of less than 0.7 μs, respectively. Therefore, the PC-IGO TFTs are suitable for large area, high-resolution active-matrix organic, and inorganic light-emitting diodes displays.

Highly Sensitive, Stretchable Pressure Sensor Using Blue Laser Annealed CNTs

A piezoresistive sensor is an essential component of wearable electronics that can detect resistance changes when pressure is applied. In general, microstructures of sensing layers have been adopted as an effective approach to enhance piezoresistive performance. However, the mold-casted microstructures typically have quite a thick layer with dozens of microscales. In this paper, a carbon microstructure is formed by blue laser annealing (BLA) on a carbon nanotube (CNT) layer, which changes the surface morphology of CNTs into carbonaceous protrusions and increases its thickness more than four times compared to the as-deposited layer. Then, the pressure sensor is fabricated using a spin-coating of styrene–ethylene–butylene–styrene (SEBS) elastomer on the BLA CNTs layer. A 1.32 µm-thick pressure sensor exhibits a high sensitivity of 6.87 × 105 kPa−1, a wide sensing range of 278 Pa~40 kPa and a fast response/recovery time of 20 ms, respectively. The stability of the pressure sensor is demonstrated by the repeated loading and unloading of 20 kPa for 4000 cycles. The stretchable pressure sensor was also demonstrated using lateral CNT electrodes on SEBS surface, exhibiting stable pressure performance, with up to 20% stretching.

Volumetric Measurement of Relative CBV Using T1-Perfusion-Weighted MRI with High Temporal Resolution Compared with Traditional T2*-Perfusion-Weighted MRI in Postoperative Patients with High-Grade Gliomas

BACKGROUND AND PURPOSE

T1-PWI with high temporal resolution may provide a reliable relative CBV value as a valid alternative to T2*-PWI under increased susceptibility. The purpose of this study was to assess the technical and clinical performance of T1-relative CBV in patients with postoperative high-grade gliomas.

MATERIALS AND METHODS

Forty-five MRIs of 34 patients with proved high-grade gliomas were included. In all MRIs, T1- and T2*-PWIs were both acquired and processed semiautomatically to generate relative CBV maps using a released commercial software. Lesion masks were overlaid on the relative CBV maps, followed by a histogram of the whole VOI. The intraclass correlation coefficient and Bland-Altman plots were used for quantitative and qualitative comparisons. Signal loss from both methods was compared using the Wilcoxon signed-rank test of zero voxel percentage. The MRIs were divided into a progression group (n = 20) and a nonprogression group (n = 14) for receiver operating characteristic curve analysis.

RESULTS

Fair intertechnique consistency was observed between the 90th percentiles of the T1- and T2*-relative CBV values (intraclass correlation coefficient = 0.558, P < .001). T2*-PWI revealed a significantly higher percentage of near-zero voxels than T1-PWI (17.7% versus 3.1%, P < .001). There was no statistically significant difference between the area under the curve of T1- and T2*-relative CBV (0.811 versus 0.793, P = .835). T1-relative CBV showed 100% sensitivity and 57.1% specificity for the detection of progressive lesions.

CONCLUSIONS

T1-relative CBV demonstrated exquisite diagnostic performance for detecting progressive lesions in postoperative patients with high-grade gliomas, suggesting the potential role of T1-PWI as a valid alternative to the traditional T2*-PWI.

Attenuation of intrinsic aging of the skin via elimination of senescent dermal fibroblasts with senolytic drugs

BACKGROUND

Skin aging is caused by numerous factors that result in structural and functional changes in cutaneous components. Research has shown that senescent cells are known to accumulate in skin aging, however, the role of senescent cells in skin aging has not been defined.

OBJECTIVES

To elucidate the role of senescent cell in skin aging, we evaluated the effect of known senolytic drugs on senescent dermal fibroblasts.

METHODS

Primary human dermal fibroblasts (HDFs) were induced to senescence by long-term passaging, UV irradiation, and H2O2 treatment. Cell viability was measured after treatment of ABT-263 and ABT-737 on HDFs. Young and aged hairless mice were intradermally injected with drugs or vehicle on the dorsal skin for 10 days. Skin specimens were obtained and reverse-transcription quantitative PCR, western blotting, and histological analysis were performed.

RESULTS

We found that ABT-263 and ABT-737 induced selective clearance of senescent dermal fibroblasts, regardless of the method of senescence induction. Aged mouse skin treated with ABT-263 or ABT-737 showed increased collagen density, epidermal thickness, and proliferation of keratinocytes, as well as decreased senescence-associated secretory phenotypes, such as MMP-1 and IL-6.

CONCLUSIONS

Taken together, our results indicate that selective clearance of senescent skin cells can attenuate and improve skin aging phenotypes and that senolytic drugs may be of potential use as new therapeutic agents for treating aging of the skin.

Gel-based precursors for the high-performance of n-channel GaInSnZnO and p-channel CuGaSnSO thin-film transistors

The performance of metal-oxide thin-film transistors (TFTs) should be further improved for the applications of next-generation displays. Here, the developments of gel-derived gallium-indium-tin-zinc oxide (GITZO) for n-channel and copper-gallium-tin-sulfide oxide (CGTSO) for p-channel TFTs are demonstrated. The a-GITZO film by gel-based precursor gives an excellent interface with ZrO _x compared to the GITZO deposited using pristine or purified precursor. The gel-derived GITZO TFT exhibits the saturation mobility (μ _sat) of 28.6 ± 2.15 cm² V^-1 s^-1, three-fold higher than the pristine one, and excellent bias stability. The boost in GITZO TFT performances is due to the purity of the metal oxide material and higher film density with smooth surface morphology. In addition, the field-effect mobility (μ _FE) of the p-channel copper-tin-sulfide-gallium oxide (CGTSO) TFT could be increased from 1.71 to 4.25 cm² V^-1 s^-1 using a gel-derived precursor solution. Therefore, these results demonstrate that the gel-derived metal-oxide precursor by the solution process is a promising one for the high performance of the TFT backplane.

Intraindividual Comparison between the Contrast-Enhanced Golden-Angle Radial Sparse Parallel Sequence and the Conventional Fat-Suppressed Contrast-Enhanced T1-Weighted Spin-Echo Sequence for Head and Neck MRI

BACKGROUND AND PURPOSE

The golden-angle radial sparse parallel-volumetric interpolated breath-hold (GRASP-VIBE) sequence is a recently introduced imaging technique with high resolution. This study compared the image quality between conventional fat-suppressed T1-weighted TSE and GRASP-VIBE after gadolinium enhancement in the head and neck region.

MATERIALS AND METHODS

Data from 65 patients with clinical indications for head and neck MR imaging between September 2020 and January 2021 were retrospectively reviewed. Two radiologists assessed the overall image quality, overall artifacts, and image conspicuities in the oropharynx, hypopharynx, and cervical lymph nodes according to 5-point scores (best score: 5). Interobserver agreement was assessed using weighted κ statistics. The SNR and contrast-to-noise ratio were calculated and compared between the 2 sequences using a paired Wilcoxon signed rank test.

RESULTS

The analysis included 52 patients (mean age, 60 [SD, 14 ] years; male, 71.2% [37/52]) who were mostly diagnosed with head and neck malignancies (94.3% [50/52]). κ statistics ranged from slight agreement in cervical lymph node conspicuity (κ = 0.18) to substantial agreement in oropharyngeal mucosal conspicuity (κ = 0.80) (κ range, 0.18-0.80). Moreover, GRASP-VIBE demonstrated significantly higher mean scores in overall image quality (4.68 [SD, 0.41] versus 3.66 [SD, 0.73]), artifacts (4.47 [SD, 0.48] versus 3.58 [SD, 0.71]), oropharyngeal mucosal conspicuity (4.85 [SD, 0.41] versus 4.11 [SD, 0.79]), hypopharyngeal mucosal conspicuity (4.84 [SD, 0.34] versus 3.58 [SD, 0.81]), and cervical lymph node conspicuity (4.79 [SD, 0.32] versus 4.08 [SD, 0.64]) than fat-suppressed T1-weighted TSE (all, P < .001). Furthermore, GRASP-VIBE demonstrated a higher SNR (22.8 [SD, 11.5] versus 11.3 [SD, 5.6], P < .001) and contrast-to-noise ratio (4.7 [SD, 5.4] versus 2.3 [SD, 2.7], P = .059) than fat-suppressed T1-weighted TSE.

CONCLUSIONS

GRASP-VIBE provided better image quality with fewer artifacts than conventional fat-suppressed T1-weighted TSE for the head and neck regions.

Triple-Stack ZnO/AlZnO/YZnO Heterojunction Oxide Thin-Film Transistors by Spray Pyrolysis for High Mobility and Excellent Stability

We demonstrate a high mobility, triple-stack ZnO/AlZnO/YZnO heterojunction thin-film transistor (TFT) using the semiconductors deposited by spray pyrolysis at 350 °C on an Al₂O₃ gate insulator. A thin layer (5 nm) of AlZnO on the top of ZnO used as an active layer of an inverted coplanar-structured TFT increases the field-effect mobility (μ_FE) from 42.56 to 82.7 cm² V^-1 s^-1. An additional 5 nm thick YZnO on the top of the ZnO/AlZnO TFT improves the electrical stability by reducing the defects in the bulk ZnO, AlZnO, and at the interface AlO_x/ZnO. The ZnO-based materials show a nanocrystalline structure with the grain size less than 20 nm. The triple-stack oxide TFT shows a μ_FE of 71.3 cm² V^-1 s^-1 with a threshold voltage (V_TH) of 2.85 V. The hysteresis voltage for pristine ZnO, ZnO/AlZnO, and ZnO/AlZnO/YZnO TFTs is 0.52, 0.24, and 0.02 V, respectively. The ZnO/AlZnO/YZnO TFT shows a negligible V_TH shift under temperature bias stress for 3600 s at 60 °C and excellent environmental stability over a few months, which is due to the presence of stronger Y-O and Al-O bonds in the back channel. The threshold voltage shift under positive bias temperature stress for pristine ZnO, ZnO/AlZnO, and ZnO/AlZnO/YZnO TFTs is 0.78, 0.40, and 0.15 V, respectively. Compared to the pristine ZnO TFT, the ZnO/AlZnO/YZnO TFT shows better environmental and bias stabilities with improved hysteresis. The experimental data of ZnO/AlZnO and ZnO/AlZnO/YZnO TFTs can be fitted by technology computer-aided design (TCAD) simulation using the density of states model of the oxide semiconductors. From the TCAD simulation, it is found that a 2D-like electron gas is formed at the narrow AlZnO layer between ZnO and YZnO.

High efficiency blue organic light-emitting diodes with below-bandgap electroluminescence

Blue organic light-emitting diodes require high triplet interlayer materials, which induce large energetic barriers at the interfaces resulting in high device voltages and reduced efficiencies. Here, we alleviate this issue by designing a low triplet energy hole transporting interlayer with high mobility, combined with an interface exciplex that confines excitons at the emissive layer/electron transporting material interface. As a result, blue thermally activated delay fluorescent organic light-emitting diodes with a below-bandgap turn-on voltage of 2.5 V and an external quantum efficiency (EQE) of 41.2% were successfully fabricated. These devices also showed suppressed efficiency roll-off maintaining an EQE of 34.8% at 1000 cd m⁻². Our approach paves the way for further progress through exploring alternative device engineering approaches instead of only focusing on the demanding synthesis of organic compounds with complex structures.

Thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs) rely on high triplet energy interlayers to confine excitons, which results in reduced performance. Here, the authors report high-performance blue TADF-OLEDs with below bandgap electroluminescence.

High Performance of Solution-Processed Amorphous p-Channel Copper-Tin-Sulfur-Gallium Oxide Thin-Film Transistors by UV/O3 Photocuring

The development of p-type metal-oxide semiconductors (MOSs) is of increasing interest for applications in next-generation optoelectronic devices, display backplane, and low-power-consumption complementary MOS circuits. Here, we report the high performance of solution-processed, p-channel copper-tin-sulfide-gallium oxide (CTSGO) thin-film transistors (TFTs) using UV/O₃ exposure. Hall effect measurement confirmed the p-type conduction of CTSGO with Hall mobility of 6.02 ± 0.50 cm² V^-1 s^-1. The p-channel CTSGO TFT using UV/O₃ treatment exhibited the field-effect mobility (μ_FE) of 1.75 ± 0.15 cm² V^-1 s^-1 and an on/off current ratio (I_ON/I_OFF) of ∼10⁴ at a low operating voltage of -5 V. The significant enhancement in the device performance is due to the good p-type CTSGO material, smooth surface morphology, and fewer interfacial traps between the semiconductor and the Al₂O₃ gate insulator. Therefore, the p-channel CTSGO TFT can be applied for CMOS MOS TFT circuits for next-generation display.

Determination of in vitro dry matter, protein, and fiber digestibility and fermentability of novel corn coproducts for swine and ruminants

New processes are being used in some dry-grind ethanol plants in the United States and Brazil to improve ethanol yield and efficiency of production while also providing nutritionally enhanced corn coproducts compared with conventional corn distillers dried grains with solubles (DDGS). The objectives of this study were to determine the chemical composition and in vitro digestibility of 5 conventional corn DDGS sources and 10 emerging novel corn coproducts for swine and ruminants, and compare coproducts produced using similar processes in the United States and Brazil. Chemical composition, on a dry matter (DM) basis, among the 15 coproducts ranged from 18.5% to 54.7% for crude protein (CP), 12.3% to 51.4% for neutral detergent fiber (NDF), 1.6% to 8.6% for acid detergent fiber, 4.7% to 12.3% for ether extract, and 1.6% to 8.6% for ash. For swine, in vitro hydrolysis of DM and CP were greater (P < 0.01) for the three U.S. corn DDGS sources compared with the two Brazilian corn DDGS sources, but in vitro fermentability of DM was comparable (P > 0.05) among all sources except one U.S. DDGS source that had less fermentable DM. High-protein and yeast dried distillers grains (Ultramax, UM; StillPro, SP) coproducts also had comparable (P > 0.05) DM fermentability for swine, but UM coproducts had greater (P < 0.01) DM and CP hydrolysis compared with SP. High-protein distillers dried grains (HP-DDG) from Brazil had greater (P < 0.01) DM and CP hydrolysis, but less (P < 0.01) DM fermentability for swine than HP-DDG produced in the United States, using the same process. For ruminants, total DM digestibility was greater (P < 0.01) in conventional DDGS sources from the United States compared with the two DDGS sources from Brazil. Total protein digestibility for ruminants was comparable and above 81% for all coproducts except for a DDGS source from Brazil, a HP-DDG source from the United States, and a UM sample. Interestingly, the corn fiber + solubles coproduct had not only relatively high digestibility of NDF (67.9%), DM (91.6%), and total CP (81.9%) for ruminants, but it also had relatively high total tract digestibility of DM (86.2%) and CP (69.9%) for swine. These results suggest that nutrient digestibility of conventional DDGS sources produced in the United States appear to be greater than corn Brazilian DDGS sources, but new process technologies being implemented in ethanol and coproduct production in both countries can enhance the nutritional value of corn coproducts for both swine and ruminants.

Free-standing nanopaper electrode for all-printed super-flexible perovskite solar cells.. [DOI: 10.21203/rs.3.rs-296909/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The development of all-printed, flexible solar cells of high efficiency and ultra-low weight will offer advancements for new market entrants. Herein, we report the design and fabrication of all-printed in ambient air, super-flexible perovskite solar cells with approaching 20% power conversion efficiency and extremely low weight of 5.1 g m-2 leading to an unprecedented power-to-weight ratio of 38,470 W Kg-1. This performance advance was achieved through the design of a highly transparent and conducting nanopaper used as a free-standing bottom electrode (FSBE). The FSBE consisted of cellulose nanocrystals grafted with semi-metallic super-reduced polyoxometalate clusters that enabled high conductivities up to 18 S cm-1 combined with transparency >96%. It also acted as a conformal barrier preventing performance loss upon heating at 95 oC under continuous illumination in inert environment; and strong resistance to decomposition when immersed in a mild citric acid water solution for 100 days, which we further exploit to demonstrate full device recyclability. The inherent flexibility of cellulose nanocrystals enabled remarkable flexibility of these cells under 2,000 repeated bending and folding cycles and mechanical strength upon extensive strain up to 20%. Notably, the nanopaper remained unaffected for strains up to 60%. These findings open the door for efficient and lightweight solar cells with a low environmental impact.

Stability of Quantum-Dot Light Emitting Diodes with Alkali Metal Carbonates Blending in Mg Doped ZnO Electron Transport Layer

We report here the fabrication of highly efficient and long-lasting quantum-dot light emitting diodes (QLEDs) by blending various alkali metal carbonate in magnesium (Mg) doped zinc oxide (ZnO) (MZO) electron transport layer (ETL). Alkali metal carbonates blending in MZO, X2CO3:MZO, control the band-gap, electrical properties, and thermal stability. This can therefore enhance the operational lifetime of QLEDs. It is found that the conductivity of X2CO3:MZO film can be controlled and the thermal stability of ETLs could be improved by X2CO3 blending in MZO. The inverted red QLEDs (R-QLEDs) with Cs2CO3:MZO, Rb2CO3:MZO, and K2CO3:MZO ETLs exhibited the operational lifetime of 407 h for the R-QLEDs with Cs2CO3:MZO, 620 h with Rb2CO3:MZO and 94 h with K2CO3:MZO ETLs at T95 with the initial luminance of 1000 cd/m2. Note that all red QLEDs showed the high brightness over 150,000 cd/m2. But the R-QLEDs with Na2CO3:MZO and Li2CO3:MZO ETLs exhibited shorter operational lifetime and poor brightness than the R-QLED with pristine MZO ETL.

Prediction of Human Papillomavirus Status and Overall Survival in Patients with Untreated Oropharyngeal Squamous Cell Carcinoma: Development and Validation of CT-Based Radiomics

BACKGROUND AND PURPOSE

Human papillomavirus is a prognostic marker for oropharyngeal squamous cell carcinoma. We aimed to determine the value of CT-based radiomics for predicting the human papillomavirus status and overall survival in patients with oropharyngeal squamous cell carcinoma.

MATERIALS AND METHODS

Eighty-six patients with oropharyngeal squamous cell carcinoma were retrospectively collected and grouped into training (n = 61) and test (n = 25) sets. For human papillomavirus status and overall survival prediction, radiomics features were selected via a random forest-based algorithm and Cox regression analysis, respectively. Relevant features were used to build multivariate Cox regression models and calculate the radiomics score. Human papillomavirus status and overall survival prediction were assessed via the area under the curve and concordance index, respectively. The models were validated in the test and The Cancer Imaging Archive cohorts (n = 78).

RESULTS

For prediction of human papillomavirus status, radiomics features yielded areas under the curve of 0.865, 0.747, and 0.834 in the training, test, and validation sets, respectively. In the univariate Cox regression, the human papillomavirus status (positive: hazard ratio, 0.257; 95% CI, 0.09-0.7; P = .008), T-stage (≥III: hazard ratio, 3.66; 95% CI, 1.34-9.99; P = .011), and radiomics score (high-risk: hazard ratio, 3.72; 95% CI, 1.21-11.46; P = .022) were associated with overall survival. The addition of the radiomics score to the clinical Cox model increased the concordance index from 0.702 to 0.733 (P = .01). Validation yielded concordance indices of 0.866 and 0.720.

CONCLUSIONS

CT-based radiomics may be useful in predicting human papillomavirus status and overall survival in patients with oropharyngeal squamous cell carcinoma.

Lanthanum Doping in Zinc Oxide for Highly Reliable Thin-Film Transistors on Flexible Substrates by Spray Pyrolysis

Solution-processed metal-oxide thin-film transistors (TFTs) are considered as one of the most favorable devices for next-generation, large-area flexible electronics. In this paper, we demonstrate the excellent material properties of lanthanum-zinc oxide (LaZnO) thin films deposited by spray pyrolysis and their application to TFTs. The threshold voltage of the LaZnO TFTs shifts toward positive gate voltage, and the mobility decreases with increasing lanthanum ratio in ZnO from 0 to 20%. The purification of the LaZnO precursor (P-LaZnO) further improves the device performance. The P-LaZnO TFT exhibits a field-effect mobility of 22.43 cm² V^-1 s^-1, zero hysteresis voltage, and negligible threshold voltage V_TH shift under positive bias temperature stress. The enhancement in the electrical properties is due to a decrease in grain size, smooth surface roughness, and reduction in the trap density in the LaZnO film. X-ray photoelectron spectroscopy (XPS) results confirm the presence of La in the TFT channel and at/near the interface of the LaZnO and ZrO_x gate insulator, leading to fewer interfacial traps. The flexible P-LaZnO TFT fabricated on the polyimide substrate exhibits a mobility of 17.64 cm² V^-1 s^-1 and a negligible V_TH shift under bias stress. Also, the inverter made of LZO TFTs is working well with a voltage gain of 17.74 (V/V) at 4 V. Therefore, the LaZnO TFT is a promising device for next-generation flexible displays.

Biocatalytic Production of a Potent Inhibitor of Adipocyte Differentiation from Phloretin Using Engineered CYP102A1

In this study, we investigated an efficient enzymatic strategy for producing potentially valuable phloretin metabolites from phlorizin, a glucoside of phloretin that is rich in apple pomace. Almond β-glucosidase efficiently removed phlorizin's glucose moiety to produce phloretin. CYP102A1 engineered by site-directed mutagenesis, domain swapping, and random mutagenesis catalyzed the highly regioselective C-hydroxylation of phloretin into 3-OH phloretin with high conversion yields. Under the optimal hydroxylation conditions of 15 g cells L^-1 and a 20 mM substrate for whole-cell biocatalysis, phloretin was regioselectively hydroxylated into 3.1 mM 3-OH phloretin each hour. Furthermore, differentiation of 3T3-L1 preadipocytes into adipocytes and lipid accumulation were dramatically inhibited by 3-OH phloretin but promoted by phloretin. Consistent with these inhibitory effects, the expression of adipogenic regulator genes was downregulated by 3-OH phloretin. We propose a platform for the sustainable production and value creation of phloretin metabolites from apple pomace capable of inhibiting adipogenesis.

Significant Performance and Stability Improvements of Low-Temperature IGZO TFTs by the Formation of In-F Nanoparticles on an SiO2 Buffer Layer

We report the performance improvement of low-temperature coplanar indium–gallium–zinc–oxide (IGZO) thin-film transistors (TFTs) with a maximum process temperature of 230 °C. We treated F plasma on the surface of an SiO₂ buffer layer before depositing the IGZO semiconductor by reactive sputtering. The field-effect mobility increases from 3.8 to 9.0 cm² V⁻¹·s⁻¹, and the threshold voltage shift (ΔV_th) under positive-bias temperature stress decreases from 3.2 to 0.2 V by F-plasma exposure. High-resolution transmission electron microscopy and atom probe tomography analysis reveal that indium fluoride (In-F) nanoparticles are formed at the IGZO/buffer layer interface. This increases the density of the IGZO and improves the TFT performance as well as its bias stability. The results can be applied to the manufacturing of low-temperature coplanar oxide TFTs for oxide electronics, including information displays.

Significant improvement of spray pyrolyzed ZnO thin film by precursor optimization for high mobility thin film transistors

Metal-oxide thin-film transistors (TFT) fabricated by spray pyrolysis are of increasing interest because of its simple process and scalability. A bottleneck issue is to get a bubble-free and dense material. We studied the effect of ammonium acetate (AA) addition in the oxide precursor solution on the performance of spray-coated ZnO TFTs. AA acts as a stabilizer, which increases the solubility of the solution and enhances the film quality by reducing the defects. With AA addition in ZnO precursor, the films are coffee ring free with high mass density and better grain orientation. The ZnO TFT with AA exhibit a remarkable improvement of its device performance such as saturation mobility increasing from 5.12 to 41.53 cm²V⁻¹s⁻¹, the subthreshold swing decreasing from 340 to 162 mV/dec and on/off current ratio increasing from ~10⁵ to 10⁸. Additionally, the TFTs show excellent stability with a low threshold voltage shift of 0.1 V under gate bias stress. Therefore, the addition of AA is a promising approach to achieve high-performance ZnO TFTs for low-cost manufacturing of displays.

0047 The Change in Melatonin Rhythm Depending on Dementia Severity in Alzheimer’s Disease (AD) Patients

Introduction

In Alzheimer’s disease (AD), both sleep and circadian dysfunctions are commonly reported and these are associated with neurodegenerative change. Actually, it has been reported that changes in circadian rhythms in AD were apparently discrete from those seen in normal aging. Previous studies reported the delayed phase in the activity or core body temperature rhythms in severe AD patients compared to normal controls. However, it is unknown whether similar changes in melatonin rhythms occur in AD patients who were not severely demented. We aimed to compare melatonin rhythms depending on dementia severity in mild and moderate AD patients.

Methods

We recruited AD patients of mild or moderate degree who had the Pittsburgh Sleep Quality Index (PSQI) score of 5 or greater and/or complained insomnia symptoms more than 3 times a week for a month. The patients were classified according to their Clinical Dementia Rating (CDR) score into 3 groups (CDR=0.5, 1, 2). The dim light melatonin onset (DLMO) was determined from seven hourly saliva samples obtained in the laboratory prior to sleep onset measured by actigraphy. The phase angle between the DLMO and sleep onset (PA-SO), and that between the DLMO and midsleep time (PA-MST) were calculated. Each group included 13, 13 and 6 AD patients with the CDR score of 0.5, 1 and 2, respectively. The DLMO and PA were compared among the 3 groups, and correlation analyses of the DLMO and PA with the MMSE in the Korean version of CERAD Packet (MMSE-KC) scores were done in total patients.

Results

There was no significant difference in the DLMO and PA between the 3 groups. The MMSE-KC score was positively correlated with the DLMO and negatively correlated with the PA-MST.

Conclusion

There were no changes in melatonin rhythms according to dementia severity in mild and moderate AD patients with sleep complaints. However, our study showed that earlier melatonin phase was associated with more impaired cognitive function.

Support

Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2017R1A2B4003493)

Amorphous Tin Oxide Applied to Solution Processed Thin-Film Transistors

The limited choice of materials for large area electronics limits the expansion of applications. Polycrystalline silicon (poly-Si) and indium gallium zinc oxide (IGZO) lead to thin-film transistors (TFTs) with high field-effect mobilities (>10 cm²/Vs) and high current ON/OFF ratios (I_On/I_Off > ~10⁷). But they both require vacuum processing that needs high investments and maintenance costs. Also, IGZO is prone to the scarcity and price of Ga and In. Other oxide semiconductors require the use of at least two cations (commonly chosen among Ga, Sn, Zn, and In) in order to obtain the amorphous phase. To solve these problems, we demonstrated an amorphous oxide material made using one earth-abundant metal: amorphous tin oxide (a-SnO_x). Through XPS, AFM, optical analysis, and Hall effect, we determined that a-SnO_x is a transparent n-type oxide semiconductor, where the SnO₂ phase is predominant over the SnO phase. Used as the active material in TFTs having a bottom-gate, top-contact structure, a high field-effect mobility of ~100 cm²/Vs and an I_On/I_Off ratio of ~10⁸ were achieved. The stability under 1 h of negative positive gate bias stress revealed a Vth shift smaller than 1 V.

Image Quality of Low-Dose Cerebral Angiography and Effectiveness of Clinical Implementation on Diagnostic and Neurointerventional Procedures for Intracranial Aneurysms

BACKGROUND AND PURPOSE

Awareness of the potential for exposure to high doses of radiation from interventional radiologic procedures has increased. The purpose of this study was to evaluate image quality and dose reduction of low-dose cerebral angiography during diagnostic and therapeutic procedures for intracranial aneurysms.

MATERIALS AND METHODS

A retrospective review of 1137 prospectively collected patients between January 2012 and June 2014 was performed. Beginning in April 2013, a dose-reduction strategy was implemented. Subjective image-quality assessment of 506 standard and 540 low-dose cerebral angiography images was performed by 2 neuroradiologists using a 5-point scale and was tested using noninferiority statistics. Radiation dose-area product and air kerma of 1046 diagnostic and 317 therapeutic procedures for intracranial aneurysms were analyzed and compared between groups before (group 1) and after (group 2) clinical implementation of a dose-reduction strategy.

RESULTS

The image quality of the low-dose cerebral angiography was not inferior on the basis of results from the 2 readers. For diagnostic cerebral angiography, the mean dose-area product and air kerma were 140.8 Gy×cm² and 1.0 Gy, respectively, in group 1 and 82.0 Gy×cm² and 0.6 Gy in group 2 (P < .001, P < .001). For the neurointerventional procedure, the mean dose-area product and air kerma were 246.0 Gy×cm² and 3.7 Gy, respectively, in group 1 and 169.8 Gy×cm² and 3.3 Gy in group 2 (P < .001, P = .291).

CONCLUSIONS

With low-dose cerebral angiography, image quality was maintained, and implementation of dose-reduction strategies reduced radiation doses in patients undergoing diagnostic and neurointerventional procedures for intracranial aneurysms.

Polystyrene enhanced crystallization of perovskites towards high performance solar cells

Perovskite solar cells have attracted significant attention due to their high efficiency and low cost. In the research on methylammonium lead-iodide (CH₃NH₃PbI₃), a lot of work has been devoted to optimize the film morphology and crystallinity resulting in an enhancement of the power conversion efficiency (PCE). A good surface coverage and uniform perovskite films are highly desirable along with a smooth and pinhole-free contact between the hole and electron extraction layers. Overall, this affects the charge transport and collection, and reduces charge recombination. Herein, we demonstrate a facile route to control perovskite crystallization by inserting an optimal amount of insulating polystyrene in the perovskite precursor solutions. The incorporation of a small amount of polystyrene results in much better surface coverage, and a smoother and uniform perovskite thin film leading to improved crystallization and larger grain size. Via careful optimization, and easy and low temperature solution-based processing, below 100 °C, we realize a device with PCE exceeding 13% along with significantly reduced leakage current.

Surface Engineering of Room Temperature-Grown Inorganic Perovskite Quantum Dots for Highly Efficient Inverted Light-Emitting Diodes

Inorganic cesium lead bromide quantum dots (CsPbBr₃ QDs) are usually synthesized via a high-temperature process (hot injection, HI). This process is similar to that used for the synthesis of other semiconductor QDs (i.e., CdSe@ZnS), which limits their potential cost advantage. CsPbBr₃ QDs can also be synthesized at room temperature (RT) in a low cost and easily scalable process, which, thus, is one of the greatest advantages of the CsPbBr₃ QDs. However, light-emitting diodes (LEDs) fabricated using RT-QDs exhibit poor performance compared to those of HI-QDs. In fact, QDs are surrounded by insulating ligands to maintain their colloidal stability but these ligands need to be removed to obtain high-performance LEDs. Here, we show that ligand removal techniques used for HI-QDs are not sufficient in the case of RT-QDs. Additional ligand engineering and annealing steps are necessary to remove the excess of ligands from RT-QD films while preventing the coalescence of the QDs. The eventual surface defects induced by annealing can be healed by a subsequent photoactivation step. Moreover, the use of solution processable inorganic charge transport layers can reduce the fabrication costs of LEDs. We fabricated an inverted LED based on a metal oxide electron transport layer and a RT-QD emitting layer which exhibited a maximum current efficiency of 17.61 cd A^-1 and a maximum luminance of 22 825 cd m^-2.