Poly(-isopropylacrylamide)--Poly(L-lysine)--Poly(L-histidine) Triblock Amphiphilic Copolymer Nanomicelles for Dual-Responsive Anticancer Drug Delivery.

A series of ABC triblock poly(-isopropylacrylamide)--poly(L-lysine)--poly(L-histidine) ((NIPAM)--(Lys)--(His)) ( = 35,50,75,100) copolymer bio-conjugates were prepared by combining reversible addition-fragmentation chain transfer polymerization and fast ring-opening polymerization of N-carboxyanhydride a-amino acid using 1,3-dicyclohexylimidazolium hydrogen carbonate as a catalyst. All the resulting triblock copolymers self-assembled into spherical micellar aggregates in aqueous solution, irrespective of the chain length of the histidine block. The micellar aggregates encapsulated the anticancer drug doxorubicin (Dox) and exhibited high drug loading efficiency.

Multi-stimuli-responsive nanomicelles fabricated using synthetic polymer polylysine conjugates for tumor microenvironment dependent drug delivery.

A series of multi-stimuli-responsive poly(N-isopropylacrylamide)-SS-block-poly(L-lysine)-block-poly(caprolactone) (p(NIPAM)-SS-b-p(Lys)-b-p(CL)) (n = 50, 75, 100, 125) triblock copolymers have been synthesized by combining reversible addition-fragmentation chain transfer polymerization of NIPAM, organo-catalyzed ring-opening polymerization (ROP) of Z-lysine N-carboxyanhydride and metal-catalyzed ROP of CL with an azide-alkyne click reaction. The pH-responsive p(Lys) and temperature-responsive p(NIPAM) blocks are tethered by a redox-responsive disulfide linker and biodegradable p(CL) blocks with different lengths are also combined to tune the lower critical solution temperature and drug loading capacity of the resulting polymers. Highly uniform micelles with ∼200 nm size were fabricated by the self-assembly of the resultant copolymers in the presence of doxorubicin (Dox) with a high Dox encapsulation efficiency of around 50%.

Enhanced Photoinduced Carrier Generation Efficiency through Surface Band Bending in Topological Insulator BiSe Thin Films by the Oxidized Layer.

Topological insulators (TIs) have become popular in the field of optoelectronic devices because of their broadband and high-sensitivity properties, which are attributed to the narrow band gap of the bulk state and high mobility of the Dirac surface state. Although perfectly grown TIs are known to exhibit strong stability against oxidation, in most cases, the existence of vacancy defects in TIs reacts to air and the characteristics of TIs is affected by oxidation. Therefore, changes in the band structure and electrical characteristics by oxidation should be considered.

Facile and scalable synthesis of topologically nanoengineered polypeptides with excellent antimicrobial activities.

A facile and scalable strategy for the quick library synthesis of linear-, hinged-, star-, and cyclic-polypeptides with broad-spectrum antimicrobial activity has been reported. The topologically nanoengineered polypeptides show superior antimicrobial activity against Gram-positive and Gram-negative bacteria and low toxicity, allowing screening of architectural polypeptides as mimics of host defense peptides for antimicrobials.

High-Performance Transparent Quantum Dot Light-Emitting Diode with Patchable Transparent Electrodes.

Patchable electrodes are attractive for applications in optoelectronic devices because of their easy and reliable processability. However, development of reliable patchable transparent electrodes (TEs) with high optoelectronic performance is challenging; till now, optoelectronic devices fabricated with patchable TEs have been exhibiting limited performance. In this study, Ag nanowire (AgNW)/poly(methyl methacrylate) (PMMA) patchable TEs are developed and the highly efficient transparent quantum dot light-emitting diodes (QLEDs) using the patchable TEs are fabricated.

P-N Junction Diode Using Plasma Boron-Doped Black Phosphorus for High-Performance Photovoltaic Devices.

This study used a spatially controlled boron-doping technique that enables a p-n junction diode to be realized within a single 2D black phosphorus (BP) nanosheet for high-performance photovoltaic application. The reliability of the BP surface and state-of-the-art 2D p-n heterostructure's gated junctions was obtained using the controllable pulsed-plasma process technique. Chemical and structural analyses of the boron-doped BP were performed using X-ray photoelectron spectroscopy, transmission electron microscopy, and first-principles density functional theory (DFT) calculations, and the electrical characteristics of a field-effect transistor based on the p-n heterostructure were determined.

Interface engineering for a stable chemical structure of oxidized-black phosphorus via self-reduction in AlO atomic layer deposition.

We evaluated the change in the chemical structure between dielectrics (AlOx and HfOx) grown by atomic layer deposition (ALD) and oxidized black phosphorus (BP), as a function of air exposure time. Chemical and structural analyses of the oxidized phosphorus species (PxOy) were performed using atomic force microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, first-principles density functional theory calculations, and the electrical characteristics of field-effect transistors (FETs). Based on the combined experiments and theoretical investigations, we clearly show that oxidized phosphorus species (PxOy, until exposed for 24 h) are significantly decreased (self-reduction) during the ALD of AlOx.

Highly Efficient and Fully Solution-Processed Inverted Light-Emitting Diodes with Charge Control Interlayers.

In this work, we developed a charge control sandwich structure around QD layers for the inverted QLEDs, the performance of which is shown to exceed that of the conventional QLEDs in terms of the external quantum efficiency (EQE) and the current efficiency (CE). The QD light-emitting layer (EML) is sandwiched with two ultrathin interfacial layers: one is a poly(9-vinlycarbazole) (PVK) layer to prevent excess electrons, and the other is a polyethylenimine ethoxylated (PEIE) layer to reduce the hole injection barrier. The sandwich structure resolves the imbalance between injected holes and electrons and brings the level of balanced charge carriers to a maximum.

AlO Passivation Effect in HfO·AlO Laminate Structures Grown on InP Substrates.

The passivation effect of an AlO layer on the electrical properties was investigated in HfO-AlO laminate structures grown on indium phosphide (InP) substrate by atomic-layer deposition. The chemical state obtained using high-resolution X-ray photoelectron spectroscopy showed that interfacial reactions were dependent on the presence of the AlO passivation layer and its sequence in the HfO-AlO laminate structures. Because of the interfacial reaction, the AlO/HfO/AlO structure showed the best electrical characteristics.

Polyethylenimine Ethoxylated-Mediated All-Solution-Processed High-Performance Flexible Inverted Quantum Dot-Light-Emitting Device.

We report on an all-solution-processed fabrication of highly efficient green quantum dot-light-emitting diodes (QLEDs) with an inverted architecture, where an interfacial polymeric surface modifier of polyethylenimine ethoxylated (PEIE) is inserted between a quantum dot (QD) emitting layer (EML) and a hole transport layer (HTL), and a MoO hole injection layer is solution deposited on top of the HTL. Among the inverted QLEDs with varied PEIE thicknesses, the device with an optimal PEIE thickness of 15.5 nm shows record maximum efficiency values of 65.

Controlling the defects and transition layer in SiO films grown on 4H-SiC via direct plasma-assisted oxidation.

The structural stability and electrical performance of SiO grown on SiC via direct plasma-assisted oxidation were investigated. To investigate the changes in the electronic structure and electrical characteristics caused by the interfacial reaction between the SiO film (thickness ~5 nm) and SiC, X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), density functional theory (DFT) calculations, and electrical measurements were performed. The SiO films grown via direct plasma-assisted oxidation at room temperature for 300s exhibited significantly decreased concentrations of silicon oxycarbides (SiOC) in the transition layer compared to that of conventionally grown (i.

Improved electroluminescence of quantum dot light-emitting diodes enabled by a partial ligand exchange with benzenethiol.

In this study, benzenethiol ligands were applied to the surface of CdSe@ZnS core@shell quantum dots (QDs) and their effect on the performance of quantum dot light-emitting diodes (QD-LEDs) was investigated. Conventional long-chained oleic acid (OA) and trioctylphosphine (TOP) capping ligands were partially replaced by short-chained benzenethiol ligands in order to increase the stability of QDs during purification and also improve the electroluminescence performance of QD-LEDs. The quantum yield of the QD solution was increased from 41% to 84% by the benzenethiol ligand exchange.

Tunable White Fluorescent Copper Gallium Sulfide Quantum Dots Enabled by Mn Doping.

Fluorescence of semiconductor quantum dots (QDs) can be tuned by engineering the band gap via size and composition control and further doping them with impurity ions. Targeting on highly bright white-emissive I-III-VI -type copper gallium sulfide (Cu-Ga-S, CGS) host QDs with the entire visible spectral coverage of blue to red, herein, Mn(2+) ion doping, through surface adsorption and lattice diffusion is fulfilled. Upon doping a distinct Mn emission from (4)T1-(6)A1 transition successfully appears in white photoluminescence (PL) of undoped CGS/ZnS core/shell QDs and with varying Mn concentration a systematic white spectral evolution of CGS:Mn/ZnS QDs is achievable with high PL quantum yield retained.

Structural and Electrical Properties of EOT HfO2 (<1 nm) Grown on InAs by Atomic Layer Deposition and Its Thermal Stability.

We report on changes in the structural, interfacial, and electrical characteristics of sub-1 nm equivalent oxide thickness (EOT) HfO2 grown on InAs by atomic layer deposition. When the HfO2 film was deposited on an InAs substrate at a temperature of 300 °C, the HfO2 was in an amorphous phase with an sharp interface, an EOT of 0.9 nm, and low preexisting interfacial defect states.

Characterization of low temperature graphene synthesis in inductively coupled plasma chemical vapor deposition process with optical emission spectroscopy.

Low-temperature graphene was synthesized at 400 degrees C with inductively coupled plasma chemical vapor deposition (PECVD) process. The effects of plasma power and flow rate of various carbon containing precursors and hydrogen on graphene properties were investigated with optical emission spectroscopy (OES). Various radicals monitored by OES were correlated with graphene film properties such as sheet resistance, I(D)/I(G) ratio of Raman spectra and transparency.

CdSe/ZnS quantum dot thin film formation by an electrospray deposition process for light-emitting devices.

About 30 nm quantum-dot thin films are formed by electrospray deposition (ESD) process and quantum-dot-light-emitting-diodes (QD-LEDs) are demonstrated. Maximum brightness of 23 000 cd m(-2) and current efficiency of 5.9 cd A(-1) are achieved with the ESD process.

Effects of nitrogen incorporation in HfO(2) grown on InP by atomic layer deposition: an evolution in structural, chemical, and electrical characteristics.

We investigated the effects of postnitridation on the structural characteristics and interfacial reactions of HfO2 thin films grown on InP by atomic layer deposition (ALD) as a function of film thickness. By postdeposition annealing under NH3 vapor (PDN) at 600 °C, an InN layer formed at the HfO2/InP interface, and ionized NHx was incorporated in the HfO2 film. We demonstrate that structural changes resulting from nitridation of HfO2/InP depend on the film thickness (i.

Polymer and small molecule mixture for organic hole transport layers in quantum dot light-emitting diodes.

The performance of quantum dot light-emitting diodes (QD-LEDs) was investigated for different hole transport layers with small molecules and polymers: poly(4-butyl-phenyl-diphenyl-amine), poly-N-vinylcarbazole (PVK), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-diphenyl-4,4'-diamine, 4,4',4″-tris(N-carbazolyl)-triphenyl-amine (TCTA), and 4,4'-bis(carbazole-9-yl)biphenyl (CBP). The electroluminescence performance of QD-LEDs was considerably improved by adding small molecules (TCTA or CBP) having high hole mobilily to the polymer hole transport material (PVK). The maximal current efficiency of QD-LED-based PVK was improved by 27% upon addition of 20 wt % TCTA due to the hole injection improvement.

Structural evolution and the control of defects in atomic layer deposited HfO2-Al2O3 stacked films on GaAs.

The structural characteristics and interfacial reactions of bilayered dielectric stacks of 3 nm HfO2/2 nm Al2O3 and 3 nm Al2O3/2 nm HfO2 on GaAs, prepared by atomic layer deposition (ALD), were examined during film growth and the postannealing process. During the postdeposition annealing (PDA) of the Al2O3/HfO2/GaAs structures at 700 °C, large amounts of Ga oxides were generated between the Al2O3 and HfO2 films as the result of interfacial reactions between interdiffused oxygen impurities and out-diffused atomic Ga. However, in the case of the HfO2/Al2O3/GaAs structures, the presence of an Al2O3 buffer layer effectively blocked the out-diffusion of atomic Ga, thus suppressing the formation of Ga oxide.

Characterization of low-k dielectric SiCOH films deposited with decamethylcyclopentasiloxane and cyclohexane.

Ultra low-k dielectric SiCOH films were deposited with decamethylcyclopentasiloxane (DMCPSO, C10H30O5Si5) and cyclohexane (C6H12) precursors by plasma-enhanced chemical vapor deposition at the deposition temperature between 25 and 200 degrees C and their chemical composition and deposition kinetics were investigated in this work. Low dielectric constants of 1.9-2.

The stages of physical activity and exercise behavior: an integrated approach to the theory of planned behavior.

This research aims to verify whether it is possible to explain the health-promoting behaviors based on sociodemographic characteristics by integrating the theory of planned behavior (TPB) proposed by Ajzen in 1988 and the transtheoretical model (TTM) proposed by Prochaska and DiClemente in 1983. In particular, the aim was to verify whether the variables of the TPB can properly distinguish the stages of change in exercise in the proposed integrated model and to figure out how attitude, subjective norm, perceived behavior control, influence, and intention-can explain the stages of change in exercise. Investigators who have taken previous training for the survey visited and interviewed 3658 people older than 30 years in the chosen town by multistage sampling method from July 27 to July 31, 2003.