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Beta-gallium oxide ( $\beta $ -Ga2O3) has attracted considerable attention for power devices due to its superior properties and the availability of device-quality native substrates compared to gallium nitride (GaN) technologies. In particular, devices such as the current aperture vertical electron transistor (CAVET) have a higher breakdown voltage compared to lateral transistors made from $\beta $ -Ga2O3. However, because of the low thermal conductivity of $\beta $ -Ga2O3, thermal management strategies at the device level are required in order to achieve high power operation. Here, we present a thermal modeling study of CAVET power transistors and analyze the impact of thermal management strategies on their thermal performance. Among the various cooling strategies, double-side cooling has the largest impact on device cooling. Double-side cooling in combination with a heat spreader can suppress the device’s thermal resistance from 24.5 to 4.86 mm $\cdot ^{\circ }\text{C}$ /W, allowing for a high-power-density CAVET device. The modeling and analysis results presented in this work can be utilized as a guide for improvement of the vertical $\beta $ -Ga2O3 device performance for future power electronics applications.

Multiple-resonance (MR) organic emitters bearing small full-width at half-maximums (FWHMs) are of general interest in organic light-emitting diodes. Indolo[3,2,1- jk ]carbazole (ICz) embedded MR-fluorophors have demonstrated extremely small FWHMs, yet in the violet region with low electroluminescence efficiency. Herein, a strategic implementation of ICz subunits into MR fluorophors is proposed by taking advantage of the synergetic effect of para -positioned nitrogen atoms to enhance electronic coupling to decrease emitting energy gap. Deep blue emitters peaking at 441 and 447 nm with FWHMs of only 18 and 21 nm are thereof obtained respectively, accompanied by ~90% photo-luminance quantum yields. With the assistance of a thermally activated delayed fluorescence sensitizer to recycle excitons, the corresponding narrowband electroluminescent devices show unprecedent high maximum external quantum efficiencies of 32.0% and 34.7% with CIE y of 0.10 and 0.085, respectively.

Pure green emitters are essential for realizing an ultrawide color gamut in next-generation displays. Herein, by fusing the difficult-to-access aza-aromatics onto B (boron)-N (nitrogen) skeleton, a hybridized multi-resonance and charge transfer (HMCT) molecule AZA-BN was successfully synthesized through an effective one-shot multiple cyclization method. AZA-BN shows pure green fluorescence with photoluminance quantum yield of 99.7 %. The corresponding green device exhibits a maximum external quantum efficiency and power efficiency of 28.2 % and 121.7 lm W-1 , respectively, with a full width half maximum (FWHM) of merely 30 nm and Commission Internationale de l'Eclairage (CIE) coordinate y of 0.69, representing the purest green bottom-emitting organic light-emitting diode.

Organic light-emitting diodes utilizing thermally activated delayed fluorescence sensitizers and multiple-resonance (MR) dopants may simultaneously offer high efficiencies and narrow-band emissions...

Multiple resonance (MR) emitters are promising for highly efficient organic light-emitting diodes (OLEDs) with narrowband emission; however, they still face intractable challenges with concentration-caused emission quenching, exciton annihilation, and spectral broadening. In this study, sterically wrapped MR dopants with a fluorescent MR core sandwiched by bulk substituents were developed to address the intractable challenges by reducing intermolecular interactions. Consequently, high photo-luminance quantum yields of ≥90% and small full width at half maximums (FWHMs) of ≤25 nm over a wide range of dopant concentrations (1 wt%-20 wt%) were recorded. In addition, we demonstrated that the sandwiched MR emitter can effectively suppress Dexter interaction when doped in a thermally activated delayed fluorescence sensitizer, eliminating exciton loss through dopant triplet. Within the above dopant concentration range, the optimal emitter realizes remarkably high maximum external quantum efficiencies of 36.3%-37.2%, identical small FWHMs of 24 nm, and alleviated efficiency roll-offs in OLEDs.

High-color-purity emissions with small a full-width at half-maximum (FWHM) are an ongoing pursuit for high-resolution displays. Though the flourishment of narrow-band emissive materials with multi-resonance induced thermally activated delayed fluorescence (MR-TADF) in the blue region, such materials have not validated their potential in other color regions. By amplifying the influence of skeleton and peripheral units, a series of highly efficient green-emitting MR-TADF materials are firstly reported. Peripheral units with electron-deficit properties can significantly narrow the energy gap for bathochromic emission without compromising the color fidelity. MR-TADF emitters with photo-luminance quantum yields of above 90 % with FWHMs of ≤25 nm are developed. The corresponding organic light-emitting diodes show maximum external quantum efficiency/ power efficiency of 22.02 %/ 69.82 lm W-1 with excellent long-term stability.

Purpose: A series of clinical studies have established the safety and efficacy of transcatheter arterial chemoembolization (TACE) with gelatin sponge microparticles (GSMs) in treating hepatocellular carcinoma (HCC). HCC can lead to obvious necrosis inside tumors, especially larger ones, although it is unclear whether such necrotic tumor tissue can induce favorable immune reactions against the tumor. Myeloid-derived suppressor cells (MDSCs) have immunosuppressive functions and are currently considered a very important cell type affecting tumor immunity. This study observed changes in MDSC frequency in peripheral blood before and after GSM–TACE to evaluate the effect on the immune function of HCC patients. Methods: Eight patients diagnosed with HCC underwent GSM–TACE treatment in the Hepatobiliary Interventional Department of Beijing Tsinghua Chang Gung Hospital, Beijing, China; we followed up with the patients over a period of 30 days post-surgery. We used flow cytometry (FCM) to quantify the frequency of MDSCs in peripheral blood before TACE, 10 days after surgery and 30 days after surgery. Results: MDSC frequency after GSM–TACE had a significant downward trend. Pre-TACE, it was 30.73% ± 11.93%, decreasing to 18.60% ± 11.37% at 10 days after operation. This decrease was not statistically significant (P > 0.05). MDSC frequency was even lower 30 days after TACE (7.63% ± 7.32%) than at 10 days after TACE (P

Thermally activated delayed fluorescence (TADF) emitters featuring preferential horizontal emitting dipole orientation (EDO) are in urgent demand for enhanced optical outcoupling efficiency in organic light-emitting diodes (OLEDs). However, simultaneously manipulating EDO and optoelectronic properties remains a formidable challenge. Here, an extended linear D-A-D structure with both enlarged donor (D) and acceptor (A) π-systems is established, not only elaborately manipulating parallel horizontal molecular orientation and EDO along its long axis by multi-driving-forces for a high horizontal dipole ratio (Θ// ), but also delocalizing distribution of frontier energy levels for optimized electronic properties. The proof-of-the-concept emitter simultaneously affords a high Θ// of 92%, a high photoluminescence quantum yield of 95%, and a fast reverse intersystem crossing rate of 1.16 × 106 s-1 . The corresponding OLED achieves a champion maximum external quantum efficiency of 39.1% among all green TADF devices without any external light-extraction techniques, together with a maximum power efficiency of 112.0 lm W-1 and alleviated efficiency roll-off. These findings may inspire even better full-color TADF emitters that push the device efficiency toward the theoretical limits.

Background Callispheres® microspheres (CSM) are the first drug-eluting bead (DEB) product developed in China; meanwhile, DEB-transarterial chemoembolization (TACE) with CSM is effective and safe in the treatment of hepatocellular carcinoma and intrahepatic cholangiocarcinoma. However, the data regarding the role of irinotecan-eluting beads-TACE (DEBIRI-TACE) using CSM for colorectal cancer liver metastases (CRLM) treatment is limited. Therefore, the present study aimed to investigate the efficacy and safety of DEBIRI-TACE using CSM in the patients with unresectable CRLM. Methods Totally, 42 unresectable CRLM patients treated with DEBIRI-TACE using CSM were continuously enrolled in this study. Postoperative treatment response (including complete response rate (CR), objective response rate (ORR), and disease control rate (DCR)), survival data (overall survival (OS)), liver function, and adverse events were documented during the follow-up. Results CR, ORR, and DCR were 19.0%, 92.9%, and 100.0%, respectively, at month (M) 1; were 23.8%, 92.9%, and 97.6%, respectively, at M3; then were 14.3%, 78.6%, and 90.5%, respectively at M6. Regarding survival profiles, 1-year OS was 81.0%; 2-year OS was 58.5%; median OS was 25.0 months (95%CI: 19.3–30.7 months). Additionally, ALT and AST experienced an obviously increased trend at 4 days, but a declined trend at 7 days, while ALB and TBIL had no obvious change. No grade 3 or grade 4 adverse event was observed, and main adverse events included fever (95.3%), pain (57.1%), fatigue (50.0%), and nausea/vomiting (42.8%). Conclusion DEBIRI-TACE with CSM achieves high treatment response, acceptable survival benefits, and good toleration in unresectable CRLM treatment.

ObjectiveTransarterial chemoembolization (TACE) stands for an ideal therapy for patients with intermediate stage HCC. This study was carried out to observe the effect of microparticles-transarterial chemoembolization (microparticles-TACE, m-TACE) on the immune function of hepatocellular carcinoma (HCC) patients by detecting the proportion of regulatory (Treg) cells in the peripheral blood of HCC patients before and after m-TACE, and to determine whether m-TACE has a positive regulatory effect on the immune function of HCC patients.Methods33 HCC patients treated with Gelatn Sponge Microparticles (GSMs-TACE) were enrolled. Flow cytometry was used to determine the proportion of Treg cells and CD4+/CD8+ T cells in peripheral blood of HCC patients 1 day before GSMs-TACE, 1 to 2 weeks and 3 to 5 weeks after GSMs-TACE, respectively.ResultsThe Tregs cell proportion of HCC patients was significantly higher than that of the healthy and cirrhosis controls and was associated with various clinical indicators of HCC patients. The Treg cell proportion in HCC patients with BCLC stage C was higher than that of stage B patients; The Treg cell proportion at 1 to 2 weeks postoperatively was 8.54 ± 1.27%, which was significantly lower than that before the GSMs-TACE. The Treg cell proportion at 3 to 5 weeks postoperatively was 7.59 ± 1.27%, which continued to decline. The ratio of CD4+/CD8+ T cells was 1.31 ± 0.56, 1.86 ± 0.73, 1.76 ± 0.58% (PConclusionThese results indicated that m-TACE could exert a positive regulatory effect on the anticancer immune function of HCC patients, which may be used in combination with immune adjuvant therapies to enhance the efficacy of HCC.

BackgroundThe aim of the study was to evaluate the usefulness of a novel modified Meso-Rex bypass surgical technique with umbilical vein recanalization and intraoperative stenting to treat portal vein cavernous transformation. MethodsIn total, 13 portal vein cavernous transformation patients underwent traditional Meso-Rex bypass surgery (Group A, n=8), modified Meso-Rex bypass without stent implantation (Group B, n=1) and modified Meso-Rex bypass with intraoperative stent implantation (Group C, n=4). ResultsIn Group A, the bypass diameter was 2-6 mm (median 3.3 mm) and blood flow velocity 25-115 cm/s (median 75 cm/s) 1 month after Meso-Rex bypass surgery, with open bypass times of 0-59 months (median 16 months); 5 patients in this group developed postoperative Meso-Rex bypass occlusions. One patient in Group B needed a thrombectomy and stent implantation during a second surgery 2 days after the modified Meso-Rex bypass, because of bypass thrombosis and umbilical vein stenosis. In Group C, the average Meso-Rex bypass diameter was 5.5-6.5 mm (median 6 mm) and the bypass vessels remained open in all patients, with blood flow rates of 45-100 cm/s (median 76.5 cm/s) 1 month after Meso-Rex bypass, up to the endpoint (12-26 months, median 18 months). The rate of bypass occlusions in Group A and Group C were 25%, 0%; 25%, 0% and 50%, 0% at 1 month, 3 months and 1 year, respectively, after Meso-Rex bypass surgery.ConclusionsOur novel modified Meso-Rex bypass approach for portal vein cavernous transformation treatment was effective with excellent long-term bypass patency.

The incidence of pancreatic cancer in China is 5.1/100,000, which has increased six times in the past 20 years, and the five-year survival rate is 1%–5%. It has replaced liver cancer as the king of new cancers. Ninety percent of new patients are in advanced stages because often the patient is diagnosed after the opportunity is lost to cure the disease (He J. et al. Ca. Cancer J. Clin. 2016; 66: 115–132), and two-thirds of the direct cause of death is a complication. The overall survival of advanced pancreatic cancer (APC) is 6.3 months. The reason for the poor prognosis is that the first tumor lesion is not sensitive to radiotherapy and chemotherapy; the second is prone to fatal complications and accelerates, which aggravates the patient’s condition there is an urgent need for new and effective treatment methods of unresectable advanced pancreatic cancer to improve the quality of life and survival time of these patients.

Owing to the increasing age of the population, the incidence of hepatocellular carcinoma (HCC) in the elderly is increasing annually.This study aims to investigate the clinical efficacy and safety of transcatheter arterial chemoembolization (TACE) combined with low-dose apatinib for unresectable HCC treatment in elderly patients (≥65 years).The clinical data from 61 elderly patients with unresectable HCC who were retrospectively analyzed.Of these 61 patients, 27 received TACE combined with low-dose (250 mg/qd) apatinib (experimental group), and 34 patients received the standard TACE treatment (control group). The short-term efficacy was evaluated according to the mRECIST1.1 standards, and the mid- and long-term efficacy and safety in the two groups of patients were evaluated.Statistical analyses were performed using the Statistical Package for the Social Sciences software (version 20.0; SPSS).Both the objective response rate and disease control rate of the experimental group were significantly higher than those of control group (P0.05). The 6-month and 12-month survival rates of the experimental group were significantly higher than those of control group too (P0.05). The median survival in the experimental group was longer than in the control group (26.0 months vs. 20.0 months). The adverse reactions related to the intake of apatinib were higher in the experimental than the control group, but were generally alleviated after symptomatic treatment.TACE combined with low-dose apatinib provides an alternative treatment option for elderly patients with unresectable HCC. Our clinical study has proven its safety and efficacy.

Solid state UV emitters have many advantages over conventional UV sources. The (Al,In,Ga)N material system is best suited to produce LEDs and laser diodes from 400 nm down to 210 nm—due to its large and tuneable direct band gap, n- and p-doping capability up to the largest bandgap material AlN and a growth and fabrication technology compatible with the current visible InGaN-based LED production. However AlGaN based UV-emitters still suffer from numerous challenges compared to their visible counterparts that become most obvious by consideration of their light output power, operation voltage and long term stability. Most of these challenges are related to the large bandgap of the materials. However, the development since the first realization of UV electroluminescence in the 1970s shows that an improvement in understanding and technology allows the performance of UV emitters to be pushed far beyond the current state. One example is the very recent realization of edge emitting laser diodes emitting in the UVC at 271.8 nm and in the UVB spectral range at 298 nm. This roadmap summarizes the current state of the art for the most important aspects of UV emitters, their challenges and provides an outlook for future developments., publishedVersion

Compared to red and green organic light-emitting diodes (OLEDs), blue OLEDs are still the bottleneck due to the lack of efficient emitters with simultaneous high exciton utilization efficiency (EUE) and short excited-state lifetime. Different from the fluorescence, phosphorescence, thermally activated delayed fluorescence (TADF), and organic radical materials traditionally used in OLEDs, we demonstrate herein a new type of emitter, cerium(III) complex Ce-1 with spin-allowed and parity-allowed d–f transition of the centre Ce3+ ion. The compound exhibits a high EUE up to 100% in OLEDs and a short excited-state lifetime of 42 ns, which is considerably faster than that achieved in efficient phosphorescence and TADF emitters. The optimized OLEDs show an average maximum external quantum efficiency (EQE) of 12.4% and Commission Internationale de L’Eclairage (CIE) coordinates of (0.146, 0.078)., OLEDs: deep blue emission from cerium(III) complex A luminescent cerium(III) complex could be promising for realizing efficient and stable deep-blue organic-LEDs required for display and lighting applications, arising from its theoretical high exciton utilization efficiency and short excited-state lifetime. Liding Wang, Zifeng Zhao, and coworkers from China have shown that a new cerium (III) complex called Ce-1, which supports a d-f energy level transition, can efficiently emit blue light with a high photoluminescence quantum yield up to 93% and a short excited-state lifetime of 42 ns. OLEDs fabricated from the complex offered a maximum external quantum efficiency of 12.4% and a luminance of about 1000 cd m−2, and their emission is characterized as being deep blue with CIE colour coordinates of (0.146, 0.078).

Highly doped n-Al0.6Ga0.4N can be used to form tunnel junctions (TJs) on deep ultraviolet (UVC) LEDs and markedly increase the light extraction efficiency (LEE) compared to the use of p-GaN/p-AlGaN. High quality Al0.6Ga0.4N was grown by NH3-assisted molecular beam epitaxy (NH3 MBE) on top of AlN on SiC substrate. The films were crack free under scanning electron microscope (SEM) for the thickness investigated (up to 1 µm). X-ray diffraction reciprocal space map scan was used to determine the Al composition and the result is in close agreement with atom probe tomography (APT) measurements. By varying the growth parameters including growth rate, and Si cell temperature, n-Al0.6Ga0.4N with an electron density of 4×1019 /cm3 and a resistivity of 3 mΩ·cm was achieved. SIMS measurement shows that a high Si doping level up to 2×1020 /cm3 can be realized using a Si cell temperature of 1450 °C and a growth rate of 210 nm/hr. Using a vanadium-based annealed contact, ohmic contact with a specific resistance of 10−6 Ω·cm2 was achieved as determined by circular transmission line measurement (CTLM). Finally, the n-type AlGaN regrowth was done on MOCVD grown UVC LEDs to form UVC TJ LED. The sample was processed into thin film flip chip (TFFC) configuration. The emission wavelength is around 278 nm and the excess voltage of processed UV LED is around 4.1 V.

Two indacenodithiophene (IDT) based water/alcohol-soluble small molecular cathode interlayers (CILs), namely TBIDTD and TBIDTCN, were designed, synthesized and applied in typical PTB7:PC71BM-based conventional structural single-junction polymer solar cells (PSCs). This is the first report where the IDT core was used as a large π-conjugated backbone for CILs. These two molecules adopt the same polar end-groups. However, compared to TBIDTD, TBIDTCN exhibits a lower LUMO (lowest unoccupied molecular orbital) level due to the introduction of dicyanomethylene groups, which is beneficial for electron transport and extraction at the interface. Systematic optimizations were carried out to confirm the interfacial modification ability of the CILs. The results indicate that both CILs can significantly improve the performance of PSCs, and the TBIDTCN-modified devices presented better performance because of the further improved electron mobility and further reduced Rs (series resistance). A PCE (power conversion efficiency) of 9.19% was achieved by the TBIDTCN-modified devices, which was nearly 1.66 times that of the bare cathode device, due to the simultaneously enhanced Voc (circuit voltage), Jsc (short-circuit current) and FF (fill factor). Our work demonstrates that the IDT-based CILs are effective in improving the performance of PSCs and presents an attractive design strategy for CILs with large π-conjugation and electron-deficient properties.

In order to investigate whether the SUVmax-liver-based interpretation could improve prognostic accuracy of interim (PET-4) and posttreatment PET/CT (PET-end), 115 patients with newly diagnosed DLBCL were recruited in the study. ROC analysis revealed the optimal threshold is 1.6-fold of SUVmax-liver for PET-4 and 1.4-fold of SUVmax-liver for PET-end. The SUVmax-liver-based interpretation had a perfect interobserver agreement, higher prognostic accuracy and positive predictive value than 5-point scale and %ΔSUVmax criteria in both PET-4 and PET-end. Dramatic differences in the outcome between patients with positive and negative PET-4/PET-end were demonstrated using Kaplan-Meier survival curves (p

We report on the small-signal high frequency characteristics of highly scaled graded AlGaN channel polarization-doped field-effect transistors (PolFETs) that show constant current gain cutoff frequency ( ${f}_{T}$ ) and maximum oscillation frequency ( ${f}_{\textsf {max}}$ ) profiles as a function of current density or gate bias. The device design includes upward and downward Al composition grading to induce a distributed 3-D charge profile, and eliminate abrupt heterojunction band offsets to achieve nonalloyed ohmic contacts with low resistance. The highest extrinsic ${f}_{T}$ of 52 GHz and ${f}_{\textsf {max}}$ of 67 GHz were measured at ${V}_{\textsf {GS}} = -1.5$ V and ${V}_{\textsf {DS}} = 9$ V, and constant ${f}_{T}$ and ${f}_{\textsf {max}}$ over wide input voltage ( ${V}_{\textsf {GS}}$ ) and output current range ( ${I}_{\textsf {DS}}$ ) were achieved.

Interim 18F-FDG PET/CT is an effective predictor in patients with DLBCL, but the standard evaluating criteria were controversial. In this study, investigators tried to investigate whether the liver SUVmax (SUVmax-liver)-based interpretation could improve the accuracy of predicting the outcomes, comparing with the Deauville five-point scale (5-PS) and the reduction rate of the maximum standardized uptake value (ΔSUVmax) criteria. In 119 patients, PET/CT after two chemotherapy cycles (PET2) were evaluated with the SUVmax-liver-based interpretation, 5-PS, and ΔSUVmax criteria. Uni- and multivariate analyses were performed. The optimal threshold for the SUVmax-liver-based interpretation was 1.6 fold of SUVmax-liver. Using the SUVmax-liver-based interpretation, the 3-year PFS and OS were 19.9% and 33.0% for patients with a positive residue while 78.2% and 86.4% for patients with negative results (p

The availability of monoclinic aluminum gallium oxide (β-(AlxGa1−x)2O3) alloys and their staggered band alignment with β-Ga2O3 makes it possible to realize two-dimensional electron gas (2DEG) through modulation doping. This brings unique advantages in improving the electrical transport properties in β-Ga2O3, and at the same time, it provides a great platform for the evaluation of a range of the fundamental materials and electrical properties of β-Ga2O3. In this chapter, we describe the early efforts in the design and epitaxy of the heterostructures and discuss the confirmation of a 2DEG through temperature-dependent Hall measurements as well as the first observation of the quantum oscillations in the material system. We will further discuss the realization of modulation-doped field-effect transistors (MODFETs), which have contributed to the evaluation of the saturation velocity and demonstration of high breakdown field in the material system. We will also discuss the methods to improve the 2DEG density and present the first double heterostructure MODFET (DH-MODFET). The early efforts on β-(AlxGa1−x)2O3/Ga2O3 heterostructures confirmed that the modulation-doped structure could be a promising architecture for electronic device applications.

Background: The global pandemic of coronavirus disease 2019 (COVID-19) has caused great challenge to the healthcare system Hypertension (HT), Diabetes Melli

We describe our system for Task 5 of SemEval 2020: Modelling Causal Reasoning in Language: Detecting Counterfactuals. Despite deep learning has achieved significant success in many fields, it still hardly drives today’s AI to strong AI, as it lacks of causation, which is a fundamental concept in human thinking and reasoning. In this task, we dedicate to detecting causation, especially counterfactuals from texts. We explore multiple pre-trained models to learn basic features and then fine-tune models with counterfactual data and pseudo-labeling data. Our team HIT-SCIR wins the first place (1st) in Sub-task 1 — Detecting Counterfactual Statements and is ranked 4th in Sub-task 2 — Detecting Antecedent and Consequence. In this paper we provide a detailed description of the approach, as well as the results obtained in this task.

The first report is presented on the RF operation of AlGaN channel transistor with Al-composition above 80%. The reported device is a polarisation-graded field effect transistor (PolFET) featuring an ultra-wide bandgap (UWBG) AlGaN channel with Al-composition grading from 65 to 82%. Transistors with a gate length of 0.8 μm were fabricated, with a current density of 265 mA/mm, the highest observed for AlGaN channel transistor with Al-composition above 80%, and f T/f MAX of 5.4/14.2 GHz. This demonstration of RF operation of polarisation-graded transistor provides a direction for achieving ultra-wide bandgap AlGaN based devices for high performance RF and power switching applications.

In this chapter, we investigate vertical transistors based on hot electron transport—tunneling hot electron transfer amplifier (THETA). As compared to lateral transport devices such as HEMTs, electron transport can be defined by heterojunction growth at a scale shorter than 10 nm, and output conductance can be controlled through doping and epitaxial engineering. Furthermore, the power dissipation in a vertical device occurs over a volume rather than in a 2D sheet; the local temperature rise is not as significant as in the lateral case. THETA had been previously demonstrated in GaAs systems, and current gain in excess of 10 had been achieved with wide bandgap AlSbAs emitter at room temperature. GaN THETA has been reported in recent years, but the current gain in these devices has remained relatively low.

White organic light-emitting diodes (WOLEDs) with high efficiencies and tunable colors attracts considerable interest from the industry and academia. Thermally activated delayed-fluorescence (TADF) emitters can revolutionize such WOLED devices; however, they still suffer from poor performances. In this study, an advanced double-emissive-layer device architecture capable of hole-trapping TADF-sensitized emissions is proposed to not only achieve a recombination zone shift for the tunable colors but also accelerate exciton emission dynamics for high efficiency and alleviated roll-off. The proof-of-concept WOLEDs exhibit significant shifts in their Commission Internationale de l'Eclairage (CIE) coordinates and correlated color temperatures from (0.40, 0.47) and 4088 K at 100 cd m-2 to (0.27, 0.33) and 9269 K at 5000 cd m-2 . Additionally, the maximum external quantum efficiency (EQE) reaches 30.7% and remains >25% over a wide luminance range of 500-5000 cd m-2 , along with an extended LT80 of over 20 000 h at an initial luminance of 100 cd m-2 . This is the first time that all-fluorescent WOLEDs have been used to realize an EQE exceeding 30%, thereby establishing a new benchmark in this field.

An ideal host for blue emitters with thermally activated delayed fluorescence (TADF) should bear a moderate polarity to relax charge transfer (CT) states of dopant for a reduced singlet-triplet energy gap (ΔEST) while utter-mostly keeping blue emission, a high triplet energy to confine exciton, and a small ΔEST for feasible charge injection. However, it is rather challenging to simultaneously fulfill all those requirements as the strong CT characteristic necessary for a small ΔEST usually enlarge polarity and lower energy levels. Here, a symmetrical ortho-linked diphenylphosphine oxide (DPO)/carbazole derivative is developed, of which the configuration resembles the bee with carbazoles as front wings, phenyl rings on DPO as back wings, hooked together by π-π interaction. This motif features a short distance of charges for a moderate polarity of 3.45 D, a twisted non-conjugation structure for a small ΔEST of 0.24 eV with a high triplet of 2.98 eV and multiple intermolecular interactions for enhanced charge transport. The corresponding blue TADF device realizes a compromise between efficiency and colors with a maximum external quantum efficiency (EQEmax) of 35.7% and a CIEy of 0.20. Furthermore, a full-TADF white device with this host realizes a EQEmax of 26.1%, representing the state-of-the-art performance.

Objective High-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT) is the standard of care in the upfront or relapsed/refractory setting in some patients with non-Hodgkin lymphoma (NHL). However, a proportion of patients do not respond to ASCT. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been widely used for staging, response evaluation, and prognosis prediction. Here, we investigated the prognostic role of PET/CT in NHL patients before and after ASCT. Methods A retrospective study was conducted at Peking University Cancer Hospital. All NHL patients who underwent ASCT between March 2010 and July 2016 were identified. Patients who had PET/CT scan before and after ASCT were included. Deauville criteria (5-point scale) were used to interpret PET scans. Univariate and multivariate survival analyses were performed using Cox regression. The predictive value of PET scanning was estimated by comparing the area under the receiver operating characteristic (ROC) curve. Results In total, 79 patients were enrolled in this study. In univariate analysis, pre- and post-ASCT PET result was identified as prognostic factors for 3-year progression-free survival (PFS) and overall survival (OS). Patients with negative pre-ASCT PET result demonstrated significantly better PFS (84.2% vs. 54.2%) and OS (89.2% vs. 63.6%) than patients with positive pre-ASCT PET result. PFS (91.6% vs. 25.3%) and OS (96.5% vs. 36.8%) were also significantly different between patients with negative and positive post-ASCT PET result. Multivariate analysis also showed a significant association between survival and post-ASCT PET result. ROC analysis revealed that the predictive value of post-ASCT PET result was superior to that of pre-ASCT PET result alone. Combined pre- and post-ASCT PET result is better for predicting outcomes in patients with NHL receiving transplantation. Deauville criteria score >3 was identified as the best cutoff value for post-ASCT PET. Conclusions Post-ASCT PET result was more important than pre-ASCT PET result in predicting outcomes for NHL patients who underwent ASCT. The prognostic significance can be improved when combining pre-ASCT PET result with post-ASCT PET result. Deauville criteria can be used for interpreting PET scans in this scenario.

Blue organic light-emitting diodes (OLEDs) are crucial for flat-panel displays and solid-state lighting. Regarding the practical application of OLEDs, high luminance and efficiencies at a low driving voltage, as well as a simple device structure, are highly desirable. However, blue OLEDs fulfilling these requirements are rare. Herein, two new sky-blue emitters, TPA-An-PPI and PCz-An-PPI, with the integration of wide-bandgap phenanthro[9,10-d]imidazole, anthracene and aromatic amine groups have been synthesized. They possess good thermal stability, bright emission in the solid state, as well as the bipolar carrier-transporting ability. Structurally simple non-doped sky-blue OLEDs with TPA-An-PPI as the emitting layer showed high performance, with the maximum luminance (Lmax) of 51 390 cd m−2, the maximum power efficiency (PEmax) of 10.42 lm W−1, and the maximum external quantum efficiency (EQEmax) of 4.61%. More importantly, at a practical high luminance of 1000 cd m−2, the PE and EQE retained high values of 8.48 lm W−1 and 4.60%, respectively, and the corresponding driving voltage was as low as 3.6 V. The performance of the non-doped device based on PCz-An-PPI was also high, although being lower than that of TPA-An-PPI.

Purpose: We evaluated the clinical efficacy of gelatin sponge microparticle (GSM) -mediated chemoembolization for the treatment of patients with liver metastases following surgery for gastrointestinal tumors. Materials and Methods: In a retrospective analysis of 37 patients who were treated at our hospital with GSM-mediated chemoembolization for liver metastases over 13 years, we evaluated outcomes using a modified response evaluation criteria in solid tumors system and also assessed liver function and adverse effects. All patients had previously undergone surgery for gastrointestinal tumors. Results: Treatment produced various degrees of necrosis and shrinkage of lesions among our patients. Two patients achieved a complete response (CR), 27 showed a partial response (PR), five had stable disease, and three had progressive disease. The overall response rate (CR + PR) was 78%, and no severe adverse effects were observed. Conclusion: GSM-mediated chemoembolization showed good clinical efficacy in the treatment of liver metastases after gastrointestinal tumor surgery. However, larger cohort and clinical controlled studies are warranted.

This paper aimed to assess the physiological effects of p53 on glucose homeostasis in vivo.A recombinant adenoviral p53 (rAd-p53) vector was administered to insulin-resistant diabetic mice. Intraperitoneal glucose tolerance test was performed in all groups of mice. Changes in fasting blood glucose, serum triglycerides, C-peptide, and insulin concentrations in treated and untreated mice were measured. Analyses of the target genes related to glucose metabolism were performed.Treatment with the rAd-p53 improved glucose control in a dose- and time-dependent manner and lowered significantly the fasting blood glucose, the serum triglycerides, and improved tolerance test of glucose as compared to control. Lowered blood glucose was associated with up-regulation of genes in the glycogenesis pathways, and down-regulation of genes in the gluconeogenesis pathways in the liver. Overexpressions of GLUT2, GK, PPAR-γ, and insulin receptor precursor were also observed in the liver and the pancreas of treated animals.Activation of p53-mediated glucose metabolism led to insulin-like antidiabetic effect in the mouse model especially by changing hepatic insulin sensitivity in the diabetic mouse model.

We present an approach to construct NURBS (Non-Uniform Rational B-Splines) surfaces for tubular engineering structures. Isogeometric shell analysis using degenerated NURBS elements for tubular structures is also presented. We developed an automatic and simple algorithm to reconstruct multiple $$C^0$$ continuous NURBS surfaces using the skeleton withdrawn from the trimmed CAD model. Isogeometric shell analysis based on Reissner–Mindlin theory was applied to the reconstructed model. To verify the efficiency of the present method, we constructed the CAD model of the car body of an electric car and simulate the deformation of an electric car using isogeometric shell analysis.

We report on β-Ga2O3 fin-shape transistors in a lateral geometry. The fin channel devices were fabricated on MOCVD-grown lightly Si-doped (010) β-Ga2O3 films. A hot phosphoric acid etch was used to remove dry etch damage and for the fabrication of sub-micron channels. Lateral fin-channel MESFETs and MISFETs with different fin widths were systematically studied. Electron conduction in the MISFET devices was found to be dominated by electron accumulation at the dielectric/semiconductor interface. In addition, the MISFETs showed higher drain-induced barrier lowering as compared to the MESFET devices. Comparison of the MISFETs with different fin widths suggested the importance of thin fin channels for better gate control and higher breakdown voltages.

High performance GaN-based micro-light-emitting diodes (µLEDs) with epitaxial n-InGaN/n-GaN tunnel junctions (InGaN TJs) were grown by metalorganic chemical vapor deposition (MOCVD). The InGaN TJs µLEDs show a significant reduction of forward voltage (Vf) by ∼0.6 V compared to the common TJs µLEDs. The Vf at 20 A cm−2 is very low varied from 3.15 V to 3.19 V in small InGaN TJ µLEDs with a size less than 40 × 40 µm2, and then significantly increases in large LEDs. Selective area growth (SAG) of TJs can overcome such size limitation by vertical out diffusion of hydrogen through the apertures on top of p-GaN. The InGaN TJ µLEDs overgrown by SAG show a size-independent low Vf ranged from 3.08 V to 3.25 V. The external quantum efficiency (EQE) of the packaged TJ µLEDs was improved by 6% compared to the common µLEDs with indium tin oxide (ITO) contact. This work solves the key challenges of MOCVD-grown TJs.

Ultra-wide bandgap (UWBG) semiconductors are attracting increasing research interest for power device applications. While promising results have been reported for various materials, it remains unclear which material and technology will succeed. Many figure of merits (FOMs) were derived for power device applications to guide material choices, including the widely used Baliga’s FOM (BFOM) to describe the resistive loss of power devices, and Baliga’s high-frequency FOM (BHFFOM) to further consider the switching loss. However, key underlying assumptions for those widely cited FOMs, including the assumption of shallow hydrogenic dopants, tend to fail for UWBG semiconductors. In this work, we revisit several important FOMs in describing vertical power electronics to properly account for both incomplete ionization and background compensation effects. We suggest that it is necessary to include the dopant ionization term (for example n/Nd in an n-drift layer) for both BFOM and BHFFOM to fully capture the potential of the UWBG semiconductors for power device applications. Incomplete dopant ionization in materials like diamond and AlN substantially lowers their FOMs for power switching, leading to high conductive and switching losses. Due to the availability of shallow donors, low background impurity compensation, and bulk substrates, β-Ga2O3 promises the best performance among the investigated materials. The modified FOMs offer a valuable guidance in material choices for power device applications.

Ultra-wide bandgap β-gallium oxide (Ga2O3) devices are of considerable interest with potential applications in both power electronics and radio frequency devices. However, current Ga2O3 device technologies are limited by the material's low intrinsic electron mobility and thermal conductivity. The former problem can be addressed by employing modulation-doped β-(AlxGa1−x)2O3/Ga2O3 heterostructures in the device architecture. In this work, (AlxGa1−x)2O3/Ga2O3 modulation-doped field effect transistors (MODFETs) have been investigated from a thermal perspective. Thermoreflectance thermal imaging was used to characterize the self-heating of the MODFETs. The (Al0.18Ga0.82)2O3 thermal conductivity (3.1–3.6 W/mK) was determined using a frequency domain thermoreflectance technique. Electro-thermal modeling was used to discern the effect of design parameters such as substrate orientation and channel length on the device self-heating behavior. Various thermal management schemes were evaluated using the electro-thermal device model. From an electro-thermal co-design perspective, the improvement in electrical performance followed by the mitigation of self-heating was also studied. For example, by employing a Ga2O3-on-SiC composite wafer, which was fabricated in this work, a 50% increase in power handling capability can be achieved as compared to a homoepitaxial device. Furthermore, flip-chip heterointegration and double-sided cooling approaches can lead to more than 2× improvement in the power handling capability. Using an augmented double-sided cooling design that includes nanocrystalline diamond passivation, a 5× improvement in the power handling capability can be accomplished, indicating the potential of the technology upon implementation of a suitable thermal management scheme.

Recent interest in the heterogeneous integration of two-dimensional (2D) materials with three-dimensional (3D) semiconductors has resulted in the implementation of direct heteroepitaxial growth via various epitaxy techniques. In this study, we demonstrated the synthesis of wafer-scale direct growth of GaN on MoS2 using plasma-assisted molecular beam epitaxy. Systematic studies were employed to understand the growth diagram of GaN on large area multi-layer MoS2, and various growth parameters such as substrate temperature and Ga to N flux ratio were investigated to study the degradation mechanism of the underlying MoS2 layer. The growth diagram of GaN on MoS2 was proposed based on the studies. The microstructure of GaN (i.e., N-rich and 550 °C) was evaluated by scanning transmission electron microscopy. Phase segregation was found in the N-rich GaN layer. A two-step growth process involving N-rich condition at a lower temperature and Ga-rich condition at a higher growth temperature was attempted to obtain the smooth and high crystalline quality of GaN. While the two-step growth method led to substantial improvement in the film quality, the removal of MoS2 was observed and the degradation of MoS2 substrate was attributed to Ga diffusion through dislocation lines based on energy-dispersive x-ray spectroscopy mapping. This work helps illuminate critical issues in the epitaxial growth of conventional semiconductors on 2D crystals for various device applications.

Exciplex-forming hosts with thermally activated delayed fluorescence (TADF) provide a viable opportunity to unlock the full potential of the yet-to-be improved power efficiencies (PEs) and stabilities of all-fluorescent white organic light-emitting diodes (WOLEDs), but this, however, is hindered by the lack of stable blue exciplexes. Here, an advanced exciplex system is proposed by incorporating bipolar charge-transport π-spacers into both the electron-donor (D) and the electron-accepter (A) to increase their distance for hypsochromic-shifted emission while maintaining the superior transporting ability. By using spirofluorene as the π-spacer, 3,3'-bicarbazole as the D-unit, and 2,4,6-triphenyl-1,3,5-triazine as the A-unit, a π-D and π-A exciplex with sky-blue emission and fast reverse intersystem crossing process is thereof constructed. Combining this exciplex-forming host, a blue TADF-sensitizer, and a yellow conventional fluorescent dopant in a single-emissive-layer, the fabricated warm-white-emissive device simultaneously exhibits a low driving voltage of 3.08 V, an external quantum efficiency of 21.4%, and a remarkable T80 (time to 80% of the initial luminance) of >8200 h at 1000 cd m-2 , accompanied by a new benchmark PE of 69.6 lm W-1 among all-fluorescent WOLEDs.

To suppress efficiency roll-off induced by triplet–triplet annihilation (TTA) and singlet–triplet annihilation (STA) in thermally activated delayed fluorescence (TADF) based organic light emitting diodes (OLEDs) is still a challenge. This issue was efficiently addressed by generating dual delayed fluorescence in the emitting layer of OLEDs. A novel TADF compound, PXZ-CMO, featuring a D-A structure was designed and synthesized. By dispersing the emitter into different hosts, devices G1 (MCP host) and G2 (DPEPO host) with identical configurations were carefully fabricated, which showed similar maximum EQE/CE of 12.1%/38.2 cd A−1 and 11.8%/33.1 cd A−1, respectively. Despite severe efficiency roll-off in device G2 with only 6.4% EQE remaining at a luminance of 1,000 cd m−2, a remarkably reduced efficiency roll-off was attained in device G1, retaining EQE as high as 10.4% at the same luminance of 1,000 cd m−2. The excellent device performance with reduced roll-off in device G1 should result from the dual delayed fluorescence in the emitting layer, which possesses great advantages in achieving dynamic and adaptive exciton distribution for radiation acceleration and quench suppression.

High flow nasal cannula (HFNC) has been shown to improve extubation outcomes in patients with hypoxemia, but the role of HFNC in weaning patients with chronic obstructive pulmonary disease (COPD) with hypercapnia from invasive ventilation is unclear. We compared the effects of HFNC to noninvasive ventilation (NIV) on postextubation vital signs and arterial blood gases (ABGs) among patients with COPD. Other outcomes included comfort scores, need for bronchoscopy, use of pulmonary medications, and chest physiotherapy. Forty-two COPD patients who had persistent hypercapnia at extubation were assigned randomly to receive HFNC (22) or NIV (20). Twenty patients in each group were enrolled for per-protocol analysis with regard to primary outcomes. Vital signs and ABGs before extubation were similar between groups. At 3 hr after extubation, pH in the NIV group was lower than HFNC group (7.42 ± 0.06 vs. 7.45 ± 0.05, p = 0.01). At 24 hr after extubation, patients' mean arterial pressure (82.97 ± 9.04 vs. 92.06 ± 11.11 mmHg, p = 0.05) and pH (7.42 ± 0.05 vs. 7.46 ± 0.03, p = 0.05) in the NIV group were lower than in the HFNC group. No significant differences were found at 48 hr after extubation. In the HFNC group, comfort scores were better (3.55 ± 2.01 vs. 5.15 ± 2.28, p = 0.02) and fewer patients needed bronchoscopy for secretion management within 48 hr after extubation (2/22 vs. 9/20, p = 0.03). HFNC is a potential alternative to NIV to wean hypercapnic COPD patients with regard to vital signs and ABGs, HFNC improved patients' comfort and secretion clearance.

We report on the first demonstration of (AlxGal-x) 2 O 3 /Ga 2 O 3 double heterostructure field effect transistor using modulation doping. $\beta$ -phase Ga 2 O 3 has emerged as a promising candidate for a wide range of device applications, including power electronic devices, radio-frequency devices and solar-blind photodetectors. The wide bandgap energy and the predicted high breakdown field, together with the availability of low-cost native substrates, make $\beta$ -Ga 2 O 3 a promising material compared to other conventional wide bandgap materials, such as GaN and SiC. The use of bulk-doped $\beta$ -Ga203 channels makes it challenging to achieve device scaling. Recently, (AlxGal-x) 2 O 3 /Ga 2 O 3 modulation doped field effect transistor structures were demonstrated as a promising candidate for electronic device applications, showing the ability to improve channel mobility, and at the same time, achieve vertical scaling. High 2DEG charge density could potentially lead to better screening of the polar-optical phonon scattering at room temperature and therefore significantly enhance the electron mobility. However, the 2DEG density that can be confined in the modulation-doped structures without the introduction of parallel channels is limited by the conduction band offset at the hetero-interface and the spacer layer thickness. In this work, a modulation-doped double heterostructure field effect transistors (DHFET) is employed to further enhance the confined 2DEG density. Its electrical characterization will be discussed in this work.

We report on the design, demonstration and current status of tunnel-injected ultra-violet light emitting diodes (UV LEDs). III-Nitride ultraviolet light emitting diodes (UV LEDs) are promising in various applications including sterilization, water purification and medical sensing. However, both the light extraction efficiency and electrical efficiency face fundamental challenges for the conventional UV LED structures. This stems from the poor p-type conductivity and high p-type contact resistance. Hole injection using interband tunneling provides an elegant solution to the fundamental issues of UV LEDs, and can resolve both the hole injection and light extraction issues that have been the primary problems for UV LEDs. In this talk, we will discuss in detail the heterostructure design and demonstration through polarization engineering to realize efficient interband tunneling in ultra-wide band gap AlGaN material. We will then outline some of the growth and fabrication challenges, and discuss our approaches to overcome these. Finally, we will present our results on tunnel-injected UV LEDs that have enabled us to achieve efficient UV light emission in the UVA and UVB wavelength ranges with on-wafer efficiencies comparable to state-of-the-art values [1,2,3]. References: 1. Yuewei Zhang, et al. ''Interband tunneling for hole injection in III-nitride ultraviolet emitters", Appl. Phys. Lett. 106, 141103 (2015); 2. Yuewei Zhang, et al. "Design of p-type cladding layers for tunnel-injected UV-A light emitting diodes", Appl. Phys. Lett. 109, 191105 (2016); 3. Yuewei Zhang, et al. “Tunnel-injected sub-260 nm ultraviolet light emitting diodes”, Appl. Phys. Lett. 110, 201102 (2017).

Objective: The purpose of this investigation is to present a preliminary clinical experience in transarterial chemoembolization (TACE) with gelatin sponge microparticles (GSMs) for barcelona clinic liver cancer (BCLC) Stage C and large hepatocellular carcinoma (HCC) patients in China. Materials and Methods: Between August 2009 and August 2012, 20 BCLC Stage C HCC patients with tumor size ≥5 cm undergoing GSMs-TACE were retrospectively analyzed. Tumor response was evaluated using modified response evaluation criteria in solid tumors (mRECIST) with enhanced magnetic resonance/computed tomography imaging performed 4–6 weeks after each GSMs-TACE procedure. Kaplan–Meier curves were used to assess overall survival (OS). Complications postprocedure was also analyzed. Results: In this cohort of 20 HCC patients, vascular invasion was present in 8 patients (40%), extrahepatic metastases in 6 patients (30%), and both in 6 individuals (30%). Median tumor size was 9.9 ± 3.2 cm. All procedures were successfully performed with minimal complications. The mean number of TACE per patient was 2.6 sessions (range 1–5). Median OS (mOS) was 14 months for the entire study population. Survival rates at 6 and 12 months were 85% and 73.7%, respectively. According to mRECIST criteria, follow-up images were obtained 6 months after initial GSMs-TACE. Five patients (25.0%) achieved complete response, 8 patients (40.0%) had partial response, 4 (20.0%) had stable disease, and 3 (15.0%) had progressive disease. The objective response rate for TACE was 65%. Conclusions: From our preliminary clinical experience, GSMs-TACE in the treatment of BCLC Stage C and large HCC appears to offer favorable survival and tumor response with low morbidity. However, further prospective studies are required to assess its safety and efficacy.

We present small-signal measurements on graded AlGaN channel polarization-doped field-effect transistors (PolFETs) that show constant current gain cutoff frequency, f T , and power gain cutoff frequency, f max , profiles as a function of current density or gate bias. AlGaN/GaN high electron mobility transistors (HEMTs) are suitable candidates for mm-wave and THz amplifiers. However their transconductance, current gain and power gain profiles reach a peak value at low current density, and then drop off significantly as the current density is increased. Reduction in power gain with gate voltage is detrimental for linearity under large signal operation, and translates into intermodulation distortion.

In this work, we investigate the use of nanoscale polarization engineering to achieve efficient hole injection from metals to ultra-wide band gap AlGaN, and we show that UV-reflective aluminum (Al) layers can be used for hole injection into p-AlGaN. The dependence of tunneling on the work function of the metal was investigated, and it was found that highly reflective Al metal layers can enable efficient hole injection into p-AlGaN, despite the relatively low work function of Al. Efficient tunneling hole injection was confirmed by light emission at 326 nm with on-wafer peak external quantum efficiency and wall-plug efficiency of 2.65% and 1.55%, respectively. A high power density of 83.7 W/cm2 was measured at 1200 kA/cm2. The metal/semiconductor tunnel junction structure demonstrated here could provide significant advantages for efficient and manufacturable device topologies for high power UV emitters.

Objective: The objective of this study was to evaluate the degradation characteristics and embolic effect of gelatin microspheres (GMSs) produced domestically in China through an experimental study comparing the embolization of rabbit renal arteries using GMSs and tris-acryl microspheres. Materials and Methods: Sixteen healthy adult New Zealand white rabbits were randomly divided into two groups. Group A was embolized with GMSs produced in China with a diameter of 150–200 μm (n = 8), and Group B was embolized with tris-acryl microspheres with a diameter of 100–200 μm (n = 8). The renal arteries were embolized through femoral artery puncture and catheterization. Renal artery angiography rechecks and hematoxylin and eosin staining of tissue sections were performed at 1 day, 4 days, 7 days, and 14 days after embolization, respectively, to observe vascular recanalization, degradation of microspheres, and embolic effect. Results: Group A: Digital subtraction angiography showed complete recanalization at 14 days. The changes in embolic necrotic areas at different time points after embolization were similar in the two groups. At 4 days after embolization, changes in glomerular structure were observed in the kidney on the embolic side. At 7 days after embolization, atrophy, degeneration, and necrosis of the glomeruli, as well as degeneration and inflammatory cell infiltration of the renal tubules, were observed in the kidney on the embolic side. At 14 days after embolization, extensive atrophy and hyalinization of the glomeruli were observed, and local renal tissue showed patchy fibrosis with calcification of internal tissue. Hyperplasia of fibrillar connective tissue was observed in the renal interstitium. Conclusion: The GMSs produced domestically in China can be completely degraded after embolizing blood vessels for 14 days. The GMSs are similar to tris-acryl microspheres in arterial embolization effect and are safe and effective.

The effectiveness of antibiotic prophylaxis (AP) in craniotomies has been clarified through the accumulation of evidence and increased antibiotic knowledge. This paper focuses on the use of AP in craniotomies during different historical periods and collects highly relevant evidence on this issue. This review surveys different AP guidelines and explains why cefazolin was selected by most guidelines. Recent prominent topics, including strategies to update and implement guidelines and antibiotic efficacy in postoperative meningitis and surveillance and decolonization therapies for methicillin-resistant Staphylococcus aureus, are discussed.

In this paper, Ba2SiO4:Eu2+ green phosphor was synthesized by sol-gel method. TGA-DTA, XRD, SEM and PL spectra were used to characterize the as-prepared phosphors. The phosphors are composed of nanoparticles with 60 nm grain size and exhibit green light with a broad peak around 500 nm. The relationship between crystal growth, morphology and luminescent properties was studied. The structure and luminescence properties of phosphors synthesized in different conditions were also discussed.

In this letter, we design and demonstrate an improved metalorganic chemical vapor deposition (MOCVD) grown reverse Al-composition graded contact layer, whereby the Al-composition of AlxGa1−xN in the contact layer is graded from the higher Al-composition as in the channel to lower Al-composition, to achieve a low resistance contact to MOCVD grown ultrawide bandgap Al0.70Ga0.30N channel metal-semiconductor field-effect transistors. Increasing the thickness of the reverse graded layer was found to improve contact layer resistance significantly, leading to a contact resistivity of 3.3 × 10−5 Ω cm2. Devices with a gate length, LG, of 0.6 μm and a source-drain spacing, LSD, of 1.5 μm displayed a maximum current density, IDS,MAX, of 635 mA/mm with an applied gate voltage, VGS, of +2 V. Breakdown measurements on transistors with a gate to drain spacing, LGD, of 770 nm had breakdown voltage greater than 220 V, corresponding to a minimum breakdown field of 2.86 MV/cm—almost 3× higher than that exhibited by lateral GaN channel devices with similar dimensions. This work provides a framework for the design of low resistance contacts to MOCVD grown high Al-content AlxGa1−xN channel transistors.