A Graphic Overlay Method for Selection of Osteotomy Site in Chronic Radial Head Dislocation: An Evaluation of 3D-printed Bone Models.

PURPOSE: Three-dimensional (3D) computed tomography imaging is now being used to generate 3D models for planning orthopaedic surgery, but the process remains time consuming and expensive. For chronic radial head dislocation, we have designed a graphic overlay approach that employs selected 3D computer images and widely available software to simplify the process of osteotomy site selection. METHODS: We studied 5 patients (2 traumatic and 3 congenital) with unilateral radial head dislocation. These patients were treated with surgery based on traditional radiographs, but they also had full sets of 3D CT imaging done both before and after their surgery: these 3D CT images form the basis for this study. From the 3D CT images, each patient generated 3 sets of 3D-printed bone models: 2 copies of the preoperative condition, and 1 copy of the postoperative condition. One set of the preoperative models was then actually osteotomized and fixed in the manner suggested by our graphic technique. Arcs of rotation of the 3 sets of 3D-printed bone models were then compared. RESULTS: Arcs of rotation of the 3 groups of bone models were significantly different, with the models osteotomized accordingly to our graphic technique having the widest arcs. CONCLUSIONS: For chronic radial head dislocation, our graphic overlay approach simplifies the selection of the osteotomy site(s). Three-dimensional-printed bone models suggest that this approach could improve range of motion of the forearm in actual surgical practice. LEVEL OF EVIDENCE: Level IV-therapeutic study.

A new mussel-inspired polydopamine sensitizer for dye-sensitized solar cells: controlled synthesis and charge transfer.

The efficient electron injection by direct dye-to-TiO(2) charge transfer and strong adhesion of mussel-inspired synthetic polydopamine (PDA) dyes with TiO(2) electrode is demonstrated. Spontaneous self-polymerization of dopamine using dip-coating (DC) and cyclic voltammetry (CV) in basic buffer solution were applied to TiO(2) layers under a nitrogen atmosphere, which offers a facile and reliable synthetic pathway to make the PDA dyes, PDA-DC and PDA-CV, with conformal surface and perform an efficient dye-to-TiO(2) charge transfer. Both synthetic methods led to excellent photovoltaic results and the PDA-DC dye exhibited larger current density and efficiency values than those in the PDA-CV dye. Under simulated AM 1.5 G solar light (100 mW cm(-2)), a PDA-DC dye exhibited a short circuit current density of 5.50 mW cm(-2), corresponding to an overall power conversion efficiency of 1.2 %, which is almost 10 times that of the dopamine dye-sensitized solar cell. The PDA dyes showed strong adhesion with the nanocrystalline TiO(2) electrodes and the interface engineering of a dye-adsorbed TiO(2) surface through the control of the coating methods, reaction times and solution concentration maximized the overall conversion efficiency, resulting in a remarkably high efficiency.

Selective Lithium Adsorption of Silicon Oxide Coated Lithium Aluminum Layered Double Hydroxide Nanocrystals and Their Regeneration.

Silicon oxide-coated lithium aluminum layered double hydroxide (Lix Al2 -LDH@SiO2 ) nanocrystals (NCs) are investigated to selectively separate lithium cations in aqueous lithium resources. We directly synthesized Lix Al2 -LDH NC arrays by oxidation of aluminum foil substrate under a urea and lithium solution. Various lithium salts, including Cl- , CO3 2- , NO3 - , and SO4 2- , were applied in aqueous solution to confirm the anion effect on the captured and released lithium quantity of the Lix Al2 -LDH NCs. In a 5% solution of sulfate ions mix with lithium chloride, the Lix Al2 -LDH NCs separated a larger quantity of lithium than in other anion conditions. To enhance regeneration stability and lithium selectivity, thin layers of SiO2 were coated onto the Lix Al2 -LDH nanostructure arrays for inhibition of nanostructure destruction after desorption of lithium cations in hot water. The Lix Al2 -LDH@SiO2 nanostructures showed enhanced properties for lithium adsorption, including increase of stable regeneration cycles from three to five cycles, and they showed high lithium selectivity in the Mg2+ , Na+ , and K+ cation mixed aqueous resource. Our nanostructured LDH lithium adsorbents would provide a facile and efficient application for cost-efficient and large-scale lithium production.

Predicting Sarcopenia of Female Elderly from Physical Activity Performance Measurement Using Machine Learning Classifiers.

PURPOSE: Sarcopenia is a symptom in which muscle mass decreases due to decreasing in the number of muscle fibers and muscle cross-sectional area as aging. This study aimed to develop a machine learning classification model for predicting sarcopenia through a inertial measurement unit (IMU)-based physical performance measurement data of female elderly. PATIENTS AND METHODS: Seventy-eight female subjects from an elderly population (aged: 78.8±5.7 years) volunteered to participate in this study. To evaluate the physical performance of the elderly, the experiment conducted timed-up-and-go test (TUG) and 6-minute walk test (6mWT) with worn a single IMU. Based on literature review, 132 features were extracted from collected data. Feature selection was performed through the Kruskal-Wallis test, and features datasets were constructed according to feature selection. Three major machine learning-based classification algorithms classified the sarcopenia group in each dataset, and the performance of classification models was compared. RESULTS: As a result of comparing the classification model performance for sarcopenia prediction, the k-nearest neighborhood algorithm (kNN) classification model using 40 major features of TUG and 6mWT showed the best performance at 88%. CONCLUSION: This study can be used as a basic research for the development of self-monitoring technology for sarcopenia.

One-dimensional organometallic molecular wires via assembly of Rh(CO)2Cl(amine): chemical control of interchain distances and optical properties.

The assembly of Rh(CO)(2)Cl(amine) via molecular orbital symmetry interactions, resulting in the formation of one-dimensional molecular wires, has been discovered. The assembly behavior was quite dependent on the type of amine. The interchain distances and optical properties could be controlled by changing the length of the alkyl chain in the amine. We believe that this discovery can be applied not only to preparing more diverse one-dimensional molecular wires via the introduction of predesigned amines but also to gaining a deeper understanding of the physical properties of molecular metals.

Fabrication of nano-structured hemispheres and pillars using laterally migrating polymer templates.

We report herein a reliable method of fabricating 2D periodic gold nanopillars with well-defined anisotropic shapes by the combinational actions of colloidal crystals and gold evaporation. The deposition of gold on a polymer template produced dual functional Janus-like nanopillars up to 633 nm in height as well as hemispherical shells with 120 nm. The thermal-induced active migration of the nanopillars from the pristine position in the lateral direction occurred at the colloidal defects while some cavity space was formed inside the gold pillars. The nano-structured gold pillars exhibited a strong surface plasmon resonance at 598 nm, as compared to that of the solid gold nanospheres at 520 nm, and a noticeable red shift to 640 nm was induced by the removal of the polymer template.

Core-Shell Structured Cobalt Sulfide/Cobalt Aluminum Hydroxide Nanosheet Arrays for Pseudocapacitor Application.

The direct synthesis of nanostructured electrode materials on three-dimensional substrates is important for their practical application in electrochemical cells without requiring the use of organic additives or binders. In this study, we present a simple two-step process to synthesize a stable core-shell structured cobalt sulfide/cobalt aluminum hydroxide nanosheet (LDH-S) for pseudocapacitor electrode application. The cobalt aluminum layered double hydroxide (CoAl-LDH) nanoplates were synthesized in basic aqueous solution with a kinetically-controlled thickness. Owing to the facile diffusion of electrolytes through the nanoplates, thin CoAl-LDH nanoplates have higher specific capacitance values than thick nanoplates. The as-grown CoAl-LDH nanoplates were transformed into core-shell structured LDH-S nanosheets by a surface modification process in Na2 S aqueous solution. The chemically robust cobalt sulfide (CoS) shell increased the electrochemical stability compared to the sulfide-free CoAl-LDH electrodes. The LDH-S electrodes exhibited high electrochemical performance in terms of specific capacitance and rate capability with a galvanostatic discharge of 1503 F g-1 at a current density of 2 A g-1 and a specific capacitance of 91 % at 50 A g-1 .

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 (CsPbX3; X = Cl, Br, I, or mixed halide compositions) form directly in the pores of MIL-101 MOF. That is, a polar organic solution of lead halide (PbX2) was impregnated into the MOF pores to give PbX2@MIL-101, which was then subjected to a perovskite-formation reaction with cesium halide (CsX) dissolved in methanol. The compositions of the halogen anions in the perovskites can be modulated with various halide precursors, leading to CsPbX3@MIL-101 composites with X3 = Cl3, Cl2Br, Br2Cl, Br3, Br2I, I2Br, and I3 that exhibit gradual variation of band gap energies and tuned emission wavelengths from 417 to 698 nm.

Effects intracerebral microinjection and intraperitoneal injection of [60]fullerene on brain functions differ in rats.

Fullerenes are condensed ring aromatic compounds with extended pi systems and unique cage structures. Fullerenes are used for medical devices such as carbon nanotubes because they are very flexible and suitable for drug delivery systems. Recently, fullerene derivatives and tube-shaped materials have been used for neuroregeneration studies, and we expect that fullerenes and carbon nanotubes have potential uses as materials in novel medical devices targeting the brain. However, little information on the effects of fullerenes on brain function is available; thus, we examined the effects of [60]fullerene (C60) on the central nervous system in this study. In a V79 cell colony Asia, the IC50 of C60 was 1620 microg/ml. In an in vivo study, 0.25 mg/kg B.W. of C60 was injected into the lateral brain ventricle or abdominal cavity of rats. The intracerebral injection of C60 increased the locomotor behavior of the rats on days 1 and 30 after the injection. The intraperitoneal injection of C60 did not change the locomotor behavior of rats acutely, but it was decreased on day 30. The intracerebral injection of C60 affected monoamine concentrations in the rat brain. In particular, serotonin turnover rates were increased in the hypothalamus, cerebral cortex, striatum, and hippocampus, and dopamine turnover rates were increased in the hypothalamus, cerebral cortex, and striatum. The intraperitoneal injection of C60 decreased only the dopamine turnover rate in the hippocampus. These results suggest that intracerebral injection of C60 had different effects on the central nervous system than intraperitoneal injection. In conclusion, it was suggested that fullerene did not cross the blood-brain barrier. The intracerebral injection of C60 affected neurotransmission in the brain widely, and the monoamine dysbolism might be related to changes in locomotor activity.

Air-Stable Transparent Silver Iodide-Copper Iodide Heterojunction Diode.

Transparent AgI-CuI heterojunctions with high rectifying diode behavior were prepared via vapor-phase iodization of metal thin films on transparent conducting oxide substrates. At room temperature, Ag and Cu metal thin films were quickly transformed into the transparent and well-crystallized ß-phase of AgI and the γ-phase of CuI, respectively. The AgI and CuI films exhibited n-type and p-type semiconductor properties, respectively, with wide band gaps. The heterojunctions were obtained by applying the CuI film to the AgI film in a sequential iodization process. AgI compounds generally have poor air-stability under light, making them suboptimal for use in electronic applications. Here, we used a CuI top layer to inhibit the photodecomposition of the AgI bottom layer, resulting in an air-stable and smooth AgI-CuI film. We also propose a simple patterning method for the AgI-CuI layer using selective decomposition of AgI without the need for lithography equipment or toxic chemicals. Although there is metal ion exchange between the two layers, each layer has a different chemical composition and crystal structure; therefore, the AgI-CuI heterojunction exhibits pn-diode behavior with a rectifying ratio of 9.4 × 104, which is comparable to that of other transparent pn-diodes. These findings open a new path for electronic application of AgI materials.

A predictive model for estimating regional skeletal muscle size by two-point dixon magnetic resonance imaging in healthy Koreans.

This study was undertaken to develop and cross-validate reference and individual predictive models for estimating functional thigh muscle cross-sectional area (TCSA) by 2-point Dixon magnetic resonance imaging (MRI). TCSAs of dominant sides at the mid-thigh level were measured by 2-point Dixon MRI (MRITCSA). Functional MRITCSA were compared with the predictive models in a sample of 92 younger (20-40 years; 28.55±4.87; n=50) and older (>65years; 71.22±4.82; n=42) Koreans. Lean body masses were measured by dual energy X-ray absorptiometry (DXALBM), and thigh isokinetic muscle strengths, extension peak torque at 60°/sec, were measured using a Biodex® dynamometer (BiodexEPT). Multiple regression analysis generated the reference model (R2=0.75 and SEE=1472.63mm2 (8%)) as follows: The reference model: functional TCSA(mm2)=-1230.49+62.81*height+3061.78*gender -2692.57*age+58.91*weight. The individual model (R2=0.80, SEE=1158.34mm2 (7%)) was as follows: The individual model: functional TCSA(mm2)=1631.62+1.76* DXALBM+9.51*BiodexEPT where height is in centimeters; weight is in kilograms; for gender, female=0 and male=1; and for age, age under 40=1 and age over 65=2. PRESS statistics of R2 and SEE were 0.78 and 1382.98mm2 for the reference model, and 0.88 and 979.02mm2 for the individual model. The 2-point Dixon MRI appears to be valid for measuring functional muscle size. Our results suggest that the reference and individual models provide acceptable estimates of functional thigh muscle CSA in healthy Korean adults. Therefore, the models developed in the study could be useful as a research tool to establish indexes for functional muscle composition in healthy Koreans.

Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals.

High-quality and millimeter-sized perovskite single crystals of CsPbBr3 and Cs4PbBr6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs4PbBr6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr3, which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr6]4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

Structural, Electrical, and Optical Properties of ZnO Film Used as Buffer Layer for CIGS Thin-Film Solar Cell.

The CuIn(x)Ga(1-x)Se2 (CIGS) using the solution-based fabrication method is attractive for thin film solar cells because of its possibilities for large-area and low-cost production. ZnO films between transparent conductive oxide (TCO) and the CdS films can improve the performances of CIGS thin-film solar cells. In this study, we investigated the characteristics of ZnO film between TCO and CIGS layers in a solar cell (AZO/ZnO/CdS/CIGS/Mo), which were deposited at various thicknesses to investigate the role of the films in CIGS solar cells. It was confirmed that the conversion efficiency of a CIGS solar cell depends on the ZnO film. For a ZnO film thickness of 80 nm, the highest power conversion efficiency that a solar cell achieved was J(sc) of 18.73 mA/cm2.

Effect of Reaction Temperature of CdS Buffer Layers by Chemical Bath Deposition Method.

This study investigated CdS deposition on a Cu(In,Ga)Se2 (CIGS) film via chemical bath deposition (CBD) in order to obtain a high-quality optimized buffer layer. The thickness and reaction temperature (from 50 degrees C to 65 degrees C) were investigated, and we found that an increase in the reaction temperature during CBD, resulted in a thicker CdS layer. We obtained a thin film with a thickness of 50 nm at a reaction temperature of 60 degrees C, which also exhibited the highest photoelectric conversion efficiency for use in solar cells. Room temperature time-resolved photoluminescence (TR-PL) measurements were performed on the Cu(In,Ga)Se2 (CIGS) thin film and CdS/CIGS samples to determine the recombination process of the photo-generated minority carrier. The device performance was found to be dependent on the thickness of the CdS layer. As the thickness of the CdS increases, the fill factor and the series resistance increased to 61.66% and decreased to 8.35 Ω, respectively. The best condition was observed at a reaction temperature of 60 degrees C, and its conversion efficiency was 12.20%.

Passivated ambipolar black phosphorus transistors.

We report the first air-passivated ambipolar BP transistor formed by applying benzyl viologen, which serves as a surface charge transfer donor for BP flakes. The passivated BP devices exhibit excellent stability under both an ambient atmosphere and vacuum; their transistor performance is maintained semi-permanently. Unlike their intrinsic p-type properties, passivated BP devices present advantageous ambipolar properties with much higher electron mobility up to ∼83 cm(2) V(-1) s(-1) from 2-terminal measurement at 300 K, compared to other reported studies on n-type BP transistors. On the basis of the n-type doping effect that originated from benzyl viologen, we also systematically investigated the BP thickness dependence of our devices on electrical properties, in which we found the best electron transport performance to be attained when an ∼10 nm thick BP flake was used.

Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping.

We synthesized binder-free Co(OH)2 nanocrystals on nickel electrodes by the ammonia transfer method in an aqueous solution and kinetically-controlled their thickness and height to enhance the capacitance through the facile diffusion of electrolytes in the nanocrystals. As thinner Co(OH)2 films were developed, the specific capacitance increased up to 1260 F g(-1) at a current density of 10 A g(-1). A thin layer of graphene oxide (GO) was used to wrap the Co(OH)2 nanocrystals to create a pseudocapacitor with high specific capacitance and good cyclic stability. This synthetic strategy enabled us to maximize the electrochemical cell performance, reaching a specific capacitance of 2710 F g(-1) under 10 A g(-1). The GO coating provides an effective method to increase adhesion on the nickel electrodes and to reduce the decomposition of Co(OH)2 during the charge-discharge process under high pH conditions. The prepared GO/Co(OH)2 nanocomposite layers provided not only high electron mobility but also ionic conductivity, especially when operated at a high current density.

Synthesis and Nanostructures of Metal Selenide Precursors for Cu(In,Ga)Se2 Thin-Film Solar Cells.

A nanoink solution-based process was developed as a low-costing method for the fabrication of Cu(In,Ga)Se2 (CIGSe) thin-film photovoltaic cells. The sonochemical synthesis of CIGSe nanocrystals of the nanoink through step-by-step mixing of the reactants was investigated. To achieve the ideal stoichiometry of Cu(In0.7 Ga0.3 )Se2 to tune the bandgap and to fabricate high-efficiency photovoltaic cells, the synthetic parameters, the concentration of hydrazine, and the amount used of the gallium precursor were investigated. As the hydrazine concentration increased, gallium loss was observed in the CIGSe product. The gallium content in the reactant mixture strongly affected the metal stoichiometry of the prepared CIGSe nanocrystals. The nanoink solution based fabrication of thin-film photovoltaic cells was also explored, and the resulting device showed a conversion efficiency of 5.17 %.