Enhancing pest control interventions by linking species distribution model prediction and population density assessment of pine wilt disease vectors in South Korea

Pine wilt disease caused by pinewood nematode is one of the most destructive forest diseases, and still spreading in South Korea despite the various control efforts. Japanese pine sawyer (JPS) and Sakhalin pine sawyer (SPS) are the main vectors of the disease. Understanding the distribution and density of the vectors is crucial since the control period is determined by the different emergence periods of the two vectors and the control method by its density and the expected damage severity. In this study, we predicted the distribution of JPS and SPS using Maxent and investigated the relationship between the resulting suitability value and the density. The population densities of JPS and SPS were obtained through a national survey using pheromone traps between 2020-2022. We converted the density data into presence/absence points to externally validate each species distribution model, then we used quantile regression to check the correlation between the suitability and population density, and finally we used three widely used thresholds to convert the model results into binary maps, and tested if they could distinguish the density by comparing the Rb value of biserial correlation. The quantile regression revealed a positive relationship between the habitat suitability and population density sampled in the field. Moreover, the binary map with threshold criteria that maximizes the sum of the sensitivity and specificity had the best density discrimination capacity with the highest Rb. A quantitative relationship between suitability and vector density measured in the field from our study provides reliability to species distribution model as practical tools for forest pest management

Ligand removal and photo-activation of CsPbBr3 quantum dots for enhanced optoelectronic devices

Perovskite quantum dots have recently emerged as a promising light source for optoelectronic applications. However, integrating them into devices while preserving their outstanding optical properties remains challenging. Due to their ionic nature, perovskite quantum dots are extremely sensitive and degrade on applying the simplest processes. To maintain their colloidal stability, they are surrounded by organic ligands; these prevent efficient charge carrier injection in devices and have to be removed. Here we report on a simple method, where a moderate thermal process followed by exposure to UV in air can efficiently remove ligands and increase the photo-luminescence of the room temperature synthesized perovskite quantum dot thin films. Annealing is accompanied by a red shift of the emission wavelength, usually attributed to the coalescence and irreversible degradation of the quantum dots. We show that it is actually related to the relaxation of the quantum dots upon the ligand removal, without the creation of non-radiative recombining defects. The quantum dot surface, as devoid of ligands, is subsequently photo-oxidized and smoothened upon exposure to UV in air, which drastically enhances their photoluminescence. This adequate combination of treatments improves by more than an order of magnitude the performances of perovskite quantum dot light emitting diodes1

Rubidium as an Alternative Cation for Efficient Perovskite Light-Emitting Diodes

Incorporation of rubidium (Rb) into mixed lead halide perovskites has recently achieved record power conversion efficiency and excellent stability in perovskite solar cells. Inspired by these tremendous advances in photovoltaics, this study demonstrates the impact of Rb incorporation into MAPbBr₃-based light emitters. Rb partially substitutes MA (methyl ammonium), resulting in a mixed cation perovskite with the formula MA_{(1–<i>x</i>)}Rb_<i>x</i>PbBr₃. Pure MAPbBr₃ crystallizes into a polycrystalline layer with highly defective sub-micrometer grains. However, the addition of a small amount of Rb forms MA_{(1–<i>x</i>)}Rb_<i>x</i>PbBr₃ nanocrystals (10 nm) embedded in an amorphous matrix of MA/Rb Br. These nanocrystals grow into defect-free sub-micrometer-sized crystallites with further addition of Rb, resulting in a 3-fold increase in exciton lifetime when the molar ratio of MABr/RbBr is 1:1. A thin film fabricated with a 1:1 molar ratio of MABr/RbBr showed the best electroluminescent properties with a current efficiency (CE) of 9.45 cd/A and a luminance of 7694 cd/m². These values of CE and luminance are, respectively, 19 and 10 times larger than those achieved by pure MAPbBr₃ devices (0.5 cd/A and 790 cd/m²). We believe this work provides important information on the future compositional optimization of Rb⁺-based mixed cation perovskites for obtaining high-performance light-emitting diodes

High-Voltage and Green-Emitting Perovskite Quantum Dot Solar Cells via Solvent Miscibility-Induced Solid-State Ligand Exchange

Advances in surface chemistry and manipulation of CsPbI3 perovskite quantum dots (PQDs) have enabled the replacement of native long-chain ligands with short-chain ligands, leading to their photovoltaic applications; however, there are no reports on those of wide-bandgap and green-emitting CsPbBr3 PQDs that are promising in high-voltage and colorful building-integrated photovoltaics. Binding energies required for ligand adsorption/desorption alter according to halide compositions of PQDs because of different soft/hard acid/base interactions, and therefore, the surface ligand-exchange process for CsPbBr3 PQDs should be developed. Herein, we demonstrate the utilization of CsPbBr3 PQDs in green light-emitting solar cells with a high open-circuit voltage (VOC) of 1.6 V, realized via solvent miscibility-induced ligand exchange. Carboxylate esters with different alkyl chain lengths are used; longer carboxylate esters show high miscibility with hydrophobic substances, leading to more efficient ligand exchange with preserving CsPbBr3 PQD size but at the same time undesired less film thickness because of the stripping-out of as-cast CsPbBr3 PQDs. Based on these results, we devise a suitably optimized solvent mixture of carboxylate esters to enable efficient ligand exchange with suppressed stripping-out phenomena. Therefore, the resultant CsPbBr3 PQD solids show a power conversion efficiency of 4.23% and a VOC of ∼1.6 V with green electroluminescence under applied voltage. © 2020 American Chemical Society.1

Multiple-Route Exciton Recombination Dynamics and Improved Stability of Perovskite Quantum Dots by Plasmonic Photonic Crystal

We have studied the excited-state exciton recombination dynamics of perovskite quantum dots (QDs) through time-resolved photoluminescence (PL), PL blinking, PL intensity-dependent lifetime modulation, and long-term photostability tests. The various spectroscopic characterizations elucidate that the perovskite QDs have multiple intrinsic exciton recombination routes even in a single QD, i.e., exciton, biexciton, and positive/negative trions, which are dissimilarly contributed to ON and OFF state emissions. We also find that the enhanced radiative recombination from placing green QDs on a photonic Ag nanotip array induces notably improved long-term PL stability. We consider that the accelerated radiative recombination of QDs by strong coupling with the plasmonics of the photonic Ag nanotip array, while eliminating nonradiative pathways, is proven to be a critical factor for improved long-term stability. © 2022 American Chemical Society.FALS

Generation of a human induced pluripotent stem cell line (YUCMi020-A) from peripheral blood mononuclear cells derived from a female with the Jr(a−) blood type

The Jra antigen, the only antigen within the JR blood group system, is a high-prevalence red blood cell (RBC) antigen found in over 99 % of the global population. An induced pluripotent stem cell line (YUCMi020-A) was generated from peripheral blood drawn from a Jr(a−) phenotype individual, who was homozygous for a null mutation of ABCG2*01N.01 (rs72552713, c.376C>T; p.Gln126*). The generated line exhibited pluripotent characteristics and no chromosomal aberrations. This cell line will serve as a cell source, enabling us to produce RBCs with the Jr(a−) phenotype in vitro, which can be used for transfusing individuals with anti-Jra antibodies

Advances in Heterostructures for Optoelectronic Devices: Materials, Properties, Conduction Mechanisms, Device Applications

Atomically thin 2D transition metal dichalcogenides (TMDs) have recently been spotlighted for next-generation electronic and photoelectric device applications. TMD materials with high carrier mobility have superior electronic properties different from bulk semiconductor materials. 0D quantum dots (QDs) possess the ability to tune their bandgap by composition, diameter, and morphology, which allows for a control of their light absorbance and emission wavelength. However, QDs exhibit a low charge carrier mobility and the presence of surface trap states, making it difficult to apply them to electronic and optoelectronic devices. Accordingly, 0D/2D hybrid structures are considered as functional materials with complementary advantages that may not be realized with a single component. Such advantages allow them to be used as both transport and active layers in next-generation optoelectronic applications such as photodetectors, image sensors, solar cells, and light-emitting diodes. Here, recent discoveries related to multicomponent hybrid materials are highlighted. Research trends in electronic and optoelectronic devices based on hybrid heterogeneous materials are also introduced and the issues to be solved from the perspective of the materials and devices are discussed. © 2023 Wiley-VCH GmbH.FALS

Room-Temperature Spray Deposition of Large-Area SnO2 Electron Transport Layer for High Performance, Stable FAPbI(3)-Based Perovskite Solar Cells

The performance and scalability of perovskite solar cells (PSCs) is highly dependent on the morphology and charge selectivity of the electron transport layer (ETL). This work demonstrates a high-speed (1800 mm min−1), room-temperature (25 °C–30 °C) deposition of large-area (62.5 cm2) tin oxide films using a multi-pass spray deposition technique. The spray-deposited SnO2 (spray-SnO2) films exhibit a controllable thickness, a unique granulate morphology and high transmittance (≈85% at 550 nm). The performance of the PSC based on spray-SnO2 ETL and formamidinium lead iodide (FAPbI3)-based perovskite is highly consistent and reproducible, achieving a maximum efficiency of ≈20.1% at an active area (A) of 0.096 cm2. Characterization results reveal that the efficiency improvement originates from the granular morphology of spray-SnO2 and high conversion rate of PbI2 in the perovskite. More importantly, spray-SnO2 films are highly scalable and able to reduce the efficiency roll-off that comes with the increase in contact-area between SnO2 and perovskite film. Based on the spray-SnO2 ETL, large-area PSC (A = 1.0 cm2) achieves an efficiency of ≈18.9%. Furthermore, spray-SnO2 ETL based PSCs also exhibit higher storage stability compared to the spin-SnO2 based PSCs. © 2021 Wiley-VCH GmbHFALS

Importance of Surface Functionalization and Purification for Narrow FWHM and Bright Green-Emitting InP CoreMultishell Quantum Dots via a Two-Step Growth Process

Indium phosphide (InP)-based quantum dots (QDs) are widely studied as environmentally friendly light emitters for display applications. However, the synthesis of InP QDs with optical properties that meet high color quality as comparable with cadmium (Cd)- and lead (Pb)-based QDs is challenging. In this article, we present the synthesis of surface-modified bright green luminescence InP core-shell quantum dots (CS-QDs) with the narrowest full width at half-maximum (fwhm) of 33 nm, absolute quantum yield (QY) of 71%, and an absorption spectra valley/depth (V/D) ratio of 0.61 after a size selection purification process. Our approach first emphasizes the heating temperatures for InP growth and second on the importance of surface stabilization of this system. We developed a two-step heating-up process to grow In(Zn)P core and coated inorganic shell with ZnSe/ZnSeS/ZnS composition. In situ surface treatment with zinc chloride (ZnCl2) and 1-octanol was carried out to enhance the PLQY and improve the surface passivation of the CS-QDs. Optical spectroscopy and surface characterization techniques including nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and infrared (IR) spectroscopy were used to analyze the properties of the CS-QDs. We suggest that this work motivates future development and optimization of surface chemistry of InP CS-QDs to enable the full access and realization of their luminescence efficiency in high-color-quality cadmium (Cd)-free displays. ©1

Identification of cell morphology parameters from automatic hematology analyzers to predict the peripheral blood CD34-positive cell count after mobilization

<div><p>Optimal timing of apheresis initiation is important for maximizing the hematopoietic stem cell (HSC) yield. This study aimed to identify useful parameters from automatic hematology analyzers for predicting the peripheral blood CD34+ cell count after mobilization. We prospectively enrolled 53 healthy donors and 72 patients, and evaluated 43 cell morphology parameters from Unicel DxH800 (Beckman Coulter, USA) and Advia 2120i (Siemens Healthcare Diagnostics, USA). The correlation of each parameter with the CD34+ cell count in pre-apheresis blood samples was analyzed. The delta neutrophil index (DNI) from Advia 2120i, standard deviation of volume of neutrophils and monocytes (SD-V-NE and SD-V-MO), standard deviation of conductivity of neutrophils and monocytes (SD-C-NE and SD-C-MO), mean conductivity of neutrophils and monocytes (MN-C-NE and MN-C-MO), and standard deviation of axial light loss of neutrophils and monocytes (SD-AL2-NE and SD-AL2-MO) from DxH800 showed significant correlations with the CD34+ cell count. SD-V-NE, SD-C-NE, and SD-C-MO showed good or fair area under the curve values for the prediction of the CD34+ cell count. SD-V-NE, SD-C-NE, and SD-C-MO from DxH800 will provide rapid, useful information for the initiation of apheresis after mobilization.</p></div