ZnF-Assisted Synthesis of Highly Luminescent InP/ZnSe/ZnS Quantum Dots for Efficient and Stable Electroluminescence.

High-quality InP-based quantum dots (QDs) have become very promising, environmentally benign light emitters for display applications, but their synthesis generally entails hazardous hydrofluoric acid. Here, we present a highly facile route to InP/ZnSe/ZnS core/shell/shell QDs with a near-unity photoluminescence quantum yield. As the key additive, the inorganic salt ZnF mildly reacts with carboxylic acid at a high temperature and in situ generates HF, which eliminates surface oxide impurities, thus facilitating epitaxial shell growth.

Adverse events and preventive measures related to COVID-19 vaccines.

The coronavirus disease 2019 (COVID-19) vaccines are categorized according to the manufacturing technique, including mRNA vaccines and adenovirus vector vaccines. According to previous studies, the reported efficacy of the COVID-19 vaccine is excellent regardless of the type of vaccine, and the majority of studies have shown similar results for safety. Most of the adverse reactions after vaccination were mild or moderate grade, and severe reactions were reported in a very small proportion.

Comparison of emergency department utilization trends between the COVID-19 pandemic and control period.

Infectious disease pandemics has a great impact on the use of medical facilities. The purpose of this study was to analyze the effects of coronavirus disease 2019 (COVID-19) on the use of emergency medical facilities in the Republic of Korea. This single-center, retrospective observational study was conducted in a tertiary teaching hospital located in Incheon Metropolitan City, Republic of Korea.

Unusual Hole Transfer Dynamics of the NiO Layer in Methylammonium Lead Tri-iodide Absorber Solar Cells.

Nickel oxides (NiO) as hole transport layers (HTLs) in inverted-type perovskite solar cells (PSCs) have been widely studied mainly because of their high stability under illumination. Increases in the power conversion efficiency (PCE) with NiO HTLs have been presented in numerous reports, although the photoluminescence (PL) quenching behavior does not coincide with the PCE increase. The dynamics of the charge carrier transport between the NiO HTLs and the organic-inorganic halide perovskite absorbers is not clearly understood yet and quite unusual, in contrast to organic/polymerics HTLs.

Formation and Encapsulation of All-Inorganic Lead Halide Perovskites at Room Temperature in Metal-Organic Frameworks.

Improving the stability and tuning the optical properties of semiconducting perovskites are vital for their applications in advanced optoelectronic devices. We present a facile synthetic method for hybrid composites of perovskites and metal-organic frameworks (MOFs). A simple two-step solution-based method without organic surfactants was employed to make all-inorganic lead-halide perovskites (CsPbX; X = Cl, Br, I, or mixed halide compositions) form directly in the pores of MIL-101 MOF.

Bifacial Passivation of Organic Hole Transport Interlayer for NiO -Based p-i-n Perovskite Solar Cells.

Methoxy-functionalized triphenylamine-imidazole derivatives that can simultaneously work as hole transport materials (HTMs) and interface-modifiers are designed for high-performance and stable perovskite solar cells (PSCs). Satisfying the fundamental electrical and optical properties as HTMs of p-i-n planar PSCs, their energy levels can be further tuned by the number of methoxy units for better alignment with those of perovskite, leading to efficient hole extraction. Moreover, when they are introduced between perovskite photoabsorber and low-temperature solution-processed NiO interlayer, widely featured as an inorganic HTM but known to be vulnerable to interfacial defect generation and poor contact formation with perovskite, nitrogen and oxygen atoms in those organic molecules are found to work as Lewis bases that can passivate undercoordinated ion-induced defects in the perovskite and NiO layers inducing carrier recombination, and the improved interfaces are also beneficial to enhance the crystallinity of perovskite.

Management of transition dipoles in organic hole-transporting materials under solar irradiation for perovskite solar cells.

In organic hole-transporting material (HTM)-based p-i-n planar perovskite solar cells, which have simple and low-temperature processibility feasible to flexible devices, the incident light has to pass through the HTM before reaching the perovskite layer. Therefore, photo-excited state of organic HTM could become important during the solar cell operation, but this feature has not usually been considered for the HTM design. Here, we prove that enhancing their property at their photo-excited states, especially their transition dipole moments, can be a methodology to develop high efficiency p-i-n perovskite solar cells.

High-Efficiency Air-Stable Colloidal Quantum Dot Solar Cells Based on a Potassium-Doped ZnO Electron-Accepting Layer.

High-efficiency colloidal quantum dot (CQD) solar cells (CQDSCs) with improved air stability were developed by employing potassium-modified ZnO as an electron-accepting layer (EAL). The effective potassium modification was achievable by a simple treatment with a KOH solution of pristine ZnO films prepared by a low-temperature solution process. The resulting K-doped ZnO (ZnO-K) exhibited EAL properties superior to those of a pristine ZnO-EAL.

Photosynthetic artificial organelles sustain and control ATP-dependent reactions in a protocellular system.

Inside cells, complex metabolic reactions are distributed across the modular compartments of organelles. Reactions in organelles have been recapitulated in vitro by reconstituting functional protein machineries into membrane systems. However, maintaining and controlling these reactions is challenging.

Extragonadal germ cell tumor of the posterior mediastinum in a child complicated with spinal cord compression: a case report.

Background: Germ cell tumors (GCTs) in children are rare neoplasms with diverse pathological findings according to the site and age of presentation. The most common symptoms in children with mediastinal GCTs, which are nonspecific, are dyspnea, chest pain, cough, hemoptysis, vena cava occlusion syndrome, and fatigue/weakness. Because of these nonspecific symptoms, it is difficult to suspect a mediastinal mass.

Manipulation of Chain Conformation for Optimum Charge-Transport Pathways in Conjugated Polymers.

A pair of different diketopyrrolopyrrole-based conjugated polymers (CPs) were designed and synthesized to investigate the effect of chain conformation on their molecular assembly. Conformation management was achieved by the incorporation of different linkers during polymerization. Through the use of computational calculations and UV-vis absorption measurements, the resulting CPs (PDPP-T and PDPP-BT) were found to exhibit partly modulated chain geometry.

CdSe@ZnS/ZnS quantum dots loaded in polymeric micelles as a pH-triggerable targeting fluorescence imaging probe for detecting cerebral ischemic area.

High photoluminescence (PL) quantum yield (QY), photostability CdSe@ZnS/ZnS core/multishell quantum dots (CM-QDs) were first applied for bioimaging. The solubility, stability and biocompatible of the fluorescence imaging probes were constructed by self-assembly of CM-QDs and pH-responsive methoxy poly(ethylene glycol)-poly(β-amino ester/amidoamine)-dodecylamine (mPEG-PAEA-DDA) multiblock copolymers. The resulting CM-QDs-loaded mPEG-PAEA-DDA micelles (CM-QDs-PEG-PAEA-DDA) exhibited lower cell cytotoxicity and higher fluorescence intensity than the core/shell CdSe@ZnS QDs-encapsulated mPEG-PAEA-DDA micelles (CS-QDs-PEG-PAEA-DDA).

High-Efficiency Photovoltaic Devices using Trap-Controlled Quantum-Dot Ink prepared via Phase-Transfer Exchange.

Colloidal-quantum-dot (CQD) photovoltaic devices are promising candidates for low-cost power sources owing to their low-temperature solution processability and bandgap tunability. A power conversion efficiency (PCE) of >10% is achieved for these devices; however, there are several remaining obstacles to their commercialization, including their high energy loss due to surface trap states and the complexity of the multiple-step CQD-layer-deposition process. Herein, high-efficiency photovoltaic devices prepared with CQD-ink using a phase-transfer-exchange (PTE) method are reported.

Photoresponse of CsPbBr and CsPbBr Perovskite Single Crystals.

High-quality and millimeter-sized perovskite single crystals of CsPbBr and CsPbBr were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, CsPbBr crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr, which generated an ultralow photoresponse under illumination.

Association of Plasminogen Activator Inhibitor-1 (PAI-1) Gene Polymorphisms with Osteoporotic Vertebral Compression Fractures (OVCFs) in Postmenopausal Women.

Osteoporosis and osteoporotic fractures are strongly associated with mortality and morbidity, both in developing and developed countries. Menopause accelerates bone loss due to estrogen deficiency and age-related linear bone loss. We investigated plasminogen activator inhibitor-1 () gene polymorphisms in postmenopausal women with osteoporotic vertebral compression fractures (OVCFs).

Fabrication of Efficient Formamidinium Tin Iodide Perovskite Solar Cells through SnF₂-Pyrazine Complex.

To fabricate efficient formamidinium tin iodide (FASnI3) perovskite solar cells (PSCs), it is essential to deposit uniform and dense perovskite layers and reduce Sn(4+) content. Here we used solvent-engineering and nonsolvent dripping process with SnF2 as an inhibitor of Sn(4+). However, excess SnF2 induces phase separation on the surface of the perovskite film.

Efficient CH3 NH3 PbI3 Perovskite Solar Cells Employing Nanostructured p-Type NiO Electrode Formed by a Pulsed Laser Deposition.

Highly transparent and nanostructured nickel oxide (NiO) films through pulsed laser deposition are introduced for efficient CH3 NH3 PbI3 perovskite solar cells. The (111)-oriented nanostructured NiO film plays a key role in extracting holes and preventing electron leakage as hole transporting material. The champion device exhibits a power conversion efficiency of 17.

Understanding the role of the dye/oxide interface via SnO2-based MK-2 dye-sensitized solar cells.

To understand the role of the dye/oxide interface, a model system using a nanocrystalline SnO2 and 3-hexyl thiophene based MK-2 dye is proposed. A thin interfacial TiO2 blocking layer (IBL) is introduced in between SnO2 and MK-2 and its effects on photocurrent-voltage, electron transport-recombination, and density of states (DOS) are systematically investigated. Compared to the bare SnO2 film, the insertion of IBL leads to a 14-fold improvement in the power conversion efficiency (PCE) despite little change in the dye adsorption amount, which is due to the 7-fold and 2-fold increase in the photocurrent density and voltage, respectively.

Laser fabrication of gold nanoparticle clustered tips for use in apertureless near-field scanning optical microscopy.

A laser fabrication method was developed to make gold nanoparticle clustered (GNC) tips for apertureless near-field scanning optical microscopes (ANSOMs) and tip-enhanced Raman spectroscopy (TERS). The near-field Rayleigh and Raman scattering of samples are highly enhanced when a gold nanoparticle cluster is synthesized on the end of the tip. This is due to the lightning rod effect in the sharp tips.

Direct Low-Temperature Growth of Single-Crystalline Anatase TiO2 Nanorod Arrays on Transparent Conducting Oxide Substrates for Use in PbS Quantum-Dot Solar Cells.

We report on the direct growth of anatase TiO2 nanorod arrays (A-NRs) on transparent conducting oxide (TCO) substrates that can be directly applied to various photovoltaic devices via a seed layer mediated epitaxial growth using a facile low-temperature hydrothermal method. We found that the crystallinity of the seed layer and the addition of an amine functional group play crucial roles in the A-NR growth process. The A-NRs exhibit a pure anatase phase with a high crystallinity and preferred growth orientation in the [001] direction.

Engineering of Sn-porphyrin networks on the silica surface: sensing of nitrophenols in water.

Sn-porphyrin networks were engineered on the surface of a thin layer chromatography (TLC) plate via Sonogashira coupling of the Sn-porphyrin building block and 1,4-diiodobenzene. The Sn-porphyrin film showed a strong Soret band absorption at 422 nm, emission at 600-630 nm, and excellent sensing performance toward nitrophenols in water.