Top-Emitting Quantum Dot Light-Emitting Diodes: Theory, Optimization, and Application.

The superior optical properties of colloidal quantum dots (QDs) have garnered significant broad interest from academia and industry owing to their successful application in self-emitting QD-based light-emitting diodes (QLEDs). In particular, active research is being conducted on QLEDs with top-emission device architectures (TQLEDs) owing to their advantages such as easy integration with conventional backplanes, high color purity, and excellent light extraction. However, due to the complicated optical phenomena and their highly sensitive optoelectrical properties to experimental variations, TQLEDs cannot be optimized easily for practical use. This review summarizes previous studies that have investigated top-emitting device structures and discusses ways to advance the performance of TQLEDs. First, theories relevant to the optoelectrical properties of TQLEDs are introduced. Second, advancements in device optimization are presented, where the underlying theories for each are considered. Finally, multilateral strategies for TQLEDs to enable their wider application to advanced industries are discussed. This work believes that this review can provide valuable insights for realizing commercial TQLEDs applicable to a broad range of applications.

Progress in the Development of Active-Matrix Quantum-Dot Light-Emitting Diodes Driven by Non-Si Thin-Film Transistors.

This paper aims to discuss the key accomplishments and further prospects of active-matrix (AM) quantum-dot (QD) light-emitting diodes (QLEDs) display. We present an overview and state-of-the-art of QLEDs as a frontplane and non-Si-based thin-film transistors (TFTs) as a backplane to meet the requirements for the next-generation displays, such as flexibility, transparency, low power consumption, fast response, high efficiency, and operational reliability. After a brief introduction, we first review the research on non-Si-based TFTs using metal oxides, transition metal dichalcogenides, and semiconducting carbon nanotubes as the driving unit of display devices. Next, QLED technologies are analyzed in terms of the device structure, device engineering, and QD patterning technique to realize high-performance, full-color AM-QLEDs. Lastly, recent research on the monolithic integration of TFT-QLED is examined, which proposes a new perspective on the integrated device. We anticipate that this review will help the readership understand the fundamentals, current state, and issues on TFTs and QLEDs for future AM-QLED displays.

Distribution of the Force in the Knee Joint during Daily Activities after Open Wedge High Tibial Osteotomy: A Rationale for the Proper Postoperative Management.

The present study was conducted to evaluate the force distribution in knee joint during daily activities after open-wedge high tibial osteotomy (OWHTO). A three-dimensional proximal tibial finite element model (FEM) was created using Mimics software to evaluate computed tomography (CT) scans of the tibia after OWHTO. The anterior and posterior gaps were 7.0 and 12.1 mm, respectively, and the target opening angle was 12 degrees. The loading ratio of the medial and lateral tibial plateaus was 6:4. To evaluate force distribution in the knee joint during activities of daily living (ADLs) after OWHTO, peak von Mises stresses (PVMSs) were analyzed at the plate and posterolateral edge region of osteotomized tibia. ADLs associated with greater knee flexion (sitting 90 degrees, standing 90 degrees, bending 90 degrees, stepping up stairs 60 degrees, and stepping downstairs 30 and 60 degrees) yielded PVMSs ranging from 195.2 to 221.5 MPa at the posterolateral edge region. In particular, stepping downstairs with knee flexion to 60 degrees produced the highest PVMS (221.5 MPa), greater than the yield strength (100-200 MPa). The highest plate PVMS was greater than 300 MPa during ADLs associated with flexion angles of approximately 90 degrees. However, these values did not exceed the yield stress (760.0 MPa). Conclusively, higher force was generated during higher flexion associated with weight-bearing and stepping downstairs produced a high force (even at lower flexion) on the posterolateral area of the tibial plateau. Therefore, a caution should be exercised when engaging in knee flexion of approximately 90 degrees and stepping downstairs in the early postoperative period when patients follow a weight-bearing rehabilitation protocol. However, this study is based on modeling; further translational studies are needed prior to clinical application.

Enhancement of vitality and activity of a plant growth-promoting bacteria (PGPB) by atmospheric pressure non-thermal plasma.

The inconsistent vitality and efficiency of plant growth promoting bacteria (PGPB) are technical limitations in the application of PGPB as biofertilizer. To improve these disadvantages, we examined the potential of micro Dielectric Barrier Discharge (DBD) plasma to enhance the vitality and functional activity of a PGPB, Bacillus subtilis CB-R05. Bacterial multiplication and motility were increased after plasma treatment, and the level of a protein involved in cell division was elevated in plasma treated bacteria. Rice seeds inoculated with plasma treated bacteria showed no significant change in germination, but growth and grain yield of rice plants were significantly enhanced. Rice seedlings infected with plasma treated bacteria showed elevated tolerance to fungal infection. SEM analysis demonstrated that plasma treated bacteria colonized more densely in the broader area of rice plant roots than untreated bacteria. The level of IAA (Indole-3-Acetic Acid) and SA (Salicylic Acid) hormone was higher in rice plants infected with plasma treated than with untreated bacteria. Our results suggest that plasma can accelerate bacterial growth and motility, possibly by increasing the related gene expression, and the increased bacterial vitality improves colonization within plant roots and elevates the level of phytohormones, leading to the enhancement of plant growth, yield, and tolerance to disease.

Role of an anatomically contoured plate and metal block for balanced stability between the implant and lateral hinge in open-wedge high-tibial osteotomy.

INTRODUCTION: Open-wedge high tibial osteotomy (OWHTO) is a well-established surgical option for medial compartment osteoarthritis of the varus knee. The initial strength of the fixation plate is critical for successful correction maintenance and healing of the osteotomy site. This study was conducted to verify if a newly designed anatomical plate (LCfit) improves the stability of both the medial implant and lateral hinge area, as well as to evaluate how the metal block contributes to both medial and lateral stability. MATERIALS AND METHODS: A finite element (FE) tibial model was combined with TomoFix plate, a LCfit plate with and without a metal block. Data analysis was conducted to evaluate the balanced stability, which refers to the enforced lateral stability resulting from redistribution of overall stress. We assessed the balanced stability of the medial implant and lateral hinge area in three cases using the same Sawbones and loads using the tibia FE model. RESULTS: The LCfit plate reduced stress by 23.1% at the lateral hinge compared to the TomoFix plate (TomoFix vs. LCfit: 34.2 ± 23.3 MPa vs. 26.3 ± 17.5 MPa). The LCfit plate with a metal block reduced stress by 40.1% at the medial plate (210.1 ± 64.2 MPa vs. 125.8 ± 65.7 MPa) and by 31.2% (26.3 ± 17.5 MPa vs. 18.1 ± 12.1 MPa) at the lateral hinge area compared to the reduction using the LCfit plate without a metal block. CONCLUSION: The newly designed fixation system for OWHTO balanced the overall stress distribution and reduced stress at the lateral hinge area compared to that using a conventional fixation system. The addition of the metal block showed additional benefits for balanced stability between the medial implant and lateral hinge area. However, this conclusion could only be drawn using the FE model in this study. Therefore, further clinical studies are necessary to reveal the clinical effect of reduced lateral stress on the occurrence of the lateral hinge fracture and the biologic effect of the metal block on the healing of the medial cortex.

Fluorescence sensor for sequential detection of zinc and phosphate ions.

A new, highly selective turn-on fluorescent chemosensor based on 2-(2'-tosylamidophenyl)thiazole (1) for the detection of zinc and phosphate ions in ethanol was synthesized and characterized. Sensor 1 showed a high selectivity for zinc compared to other cations and sequentially detected hydrogen pyrophosphate and hydrogen phosphate. The fluorescence mechanism can be explained by two different mechanisms: (i) the inhibition of excited-state intramolecular proton transfer (ESIPT) and (ii) chelation-induced enhanced fluorescence by binding with Zn(2+). The sequential detection of phosphate anions was achieved by the quenching and subsequent revival of ESIPT.

Enhanced cytosolic drug delivery using fully biodegradable poly(amino oxalate) particles.

Rapid endosomal escape of drug carriers is crucial to enhancing the efficacy of their macromolecular payload, especially proteins that are susceptible to lysosomal degradation. In this paper, we report poly(amino oxalate) (PAOX) as a new protein delivery system that is capable of disrupting endosomes and mediating cytosolic drug delivery. A cationic fully-biodegradable PAOX was synthesized from a one-step reaction of oxalyl chloride, cyclohexanedimethanol and piperazinediethanol. The incorporation of tertiary amine groups in the backbone of PAOX enhanced its hydrolytic nature, which results in a fast drug release. The studies of confocal fluorescence imaging using calcein and LysoTracker Red revealed that PAOX particles disrupted endosomes via "proton sponge" effects and mediated the cytosolic delivery of membrane-impermeable calcein. A protein delivery efficiency of PAOX particles was evaluated using catalase as a model protein. Catalase-loaded PAOX microparticles significantly inhibited hydrogen peroxide generation in Phorbol-12-myristate-13-acetate (PMA)-stimulated macrophages, in a dose-dependent manner. Given the excellent biocompatibility and physicochemical properties, we anticipate that PAOX is a promising cytosolic protein delivery system and is useful for the treatment of acute inflammatory diseases.

A biodegradable and biocompatible drug-delivery system based on polyoxalate microparticles.

Drug delivery using biodegradable polymeric microparticles is becoming an important means of delivering therapeutic agents. In this work, we describe polyoxalate microparticles as a biodegradable and biocompatible protein drug-delivery system. Polyoxalate was synthesized from a polycondensation reaction between oxalyl chloride and 1,4-cyclohexanedimethanol under basic conditions. Polyoxalate, in design, undergoes hydrolytic degradation to generate non-toxic low-molecular-weight compounds that can be easily excreted from a body. Polyoxalate was hydrophobic and had a half-life of 6.5 days at pH 7.4. This hydrophobic polyoxalate could be formulated into microparticles by a double emulsion method and encapsulate proteins with a loading efficiency of more than 80%. Cytotoxicity evaluation using RAW 264.7 cells indicated that polyoxalate microparticles exhibited a cytotoxicity profile superior to PLGA microparticles. The polyoxalate microparticles were taken up by macrophages in vitro as confirmed by confocal fluorescence microscopy. The ease of synthesis coupled with the physicochemical properties and excellent biocompatibility make this polyoxalate a promising candidate for protein-delivery applications.

Polyoxalate nanoparticles as a biodegradable and biocompatible drug delivery vehicle.

One of major challenges in the drug delivery lies in the development of nanoparticles that are effectively delivered to targeted cells and release their payload over an extended period to achieve a clinical response. In this paper, we report a new family of biocompatible and biodegradable polymer, termed polyoxalate that degrades hydrolytically into nontoxic byproducts. Polyoxalate was synthesized from a simple one-step polymerization reaction of 1,4-cyclohexanedimethanol and oxalyl chloride and had a MW of approximately 11000 Da. This polymer was designed to degrade by water hydrolysis into 1,4-cyclohexanedimethanol and oxalic acid, which can be easily removed from a body. Polyoxalate had a hydrophobic backbone and was formulated into nanoparticles with a mean diameter of 600 nm, which is suitable for drug delivery involving phagocytosis by macrophages. Polyoxalate nanoparticles were readily taken up by RAW 264.7 macrophage cells and HEK (human embryonic kidney) 293 cells and exhibited a minimal cytotoxicity in a time- and dose-dependent manner. In comparison with PLGA nanoparticles, polyoxalate nanoparticles had a significantly higher cell viability. We anticipated that the ease of synthesis and excellent biocompatibility make polyoxalate highly potent for numerous applications in drug delivery.