Zr-Doped High-Voltage Spinel LiNi0.5Mn1.5O4 Manufactured via the Coprecipitation Method.

Lithium nickel manganese oxide (LiNi0.5Mn1.5O4, LNMO) provides an elevated operating potential of 4.7 V and a theoretical capacity of 147 mAh g-1, without the need for expensive cobalt. Zr-doped LNMO was synthesized using the coprecipitation technique with Couette-Taylor flow. FE-SEM images and TEM SAED patterns revealed that Zr-doped LNMO formed truncated octahedral structures with exposed (100) crystal facets. When compared to undoped LNMO, Zr-doped LNMO exhibited superior electrochemical performance. Electrochemical evaluations showed that Zr0.1-LNMO achieved 85.9% rate capability at 10 C, significantly outperforming the 69.1% of bare LNMO. In addition, Zr0.1-LNMO exhibited high stability, maintaining 76.8% of the discharge capacity even after 100 cycles.

Effect of Nanoparticles in LiFePO4 Cathode Material Using Organic/Inorganic Composite Solid Electrolyte for All-Solid-State Batteries.

Herein, we report the effect of using nanoparticles of LiFePO4 on the electrochemical properties of all-solid-state batteries (ASSBs) with a solid electrolyte. LiFePO4 (LFP) cathode materials are promising cathode materials in polymer-based composite solid electrolytes because of their limited electrochemical window range. However, LFP cathodes exhibit poor electric conductivity and sluggish lithium ion diffusion. In addition, there is a disadvantage in that the interfacial resistance increases due to poor contact between the LFP cathode material and the solid electrolyte when composing the composite cathode. The nano-sized LFP cathode material increases the contact area between solid electrolyte in the positive electrode and enhances lithium ion diffusion. Therefore, the structural differences and electrochemical performance of these nanoscale LFP cathode materials in the ASSB were studied by X-ray diffraction, scanning electron microscopy, and electrochemical analysis.

High performance of critical shoulder angle for diagnosing rotator cuff tears on radiographs.

PURPOSE: Previous studies have reported that a high critical shoulder angle (CSA) is associated with rotator cuff tears (RCTs). However, the available evidence concerning the strength of the association of these parameters with the pathogenesis of RCTs is conflicting. The aim in the present meta-analysis was to assess the diagnostic performance of CSA for detecting RCTs. METHODS: The PubMed and EMBASE databases were searched for diagnostic accuracy studies of CSA for detecting RCT. Quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We calculated the pooled diagnostic accuracy of CSA, including diagnostic odd ratios (DORs) with 95% confidence intervals (CIs). Bivariate random-effect modeling with forest plots and hierarchical summary receiver operating characteristic curves was performed to evaluate the pooled sensitivity and specificity of CSA. For heterogeneity exploration, we performed meta-regression analyses. RESULTS: Eight studies including 902 patients (460 patients with RCT and 442 control patients) were included. According to DOR, CSA was an informative feature for RCT (DOR 8; 95% CI 4-16). The overall diagnostic performance of CSA for RCT was good (sensitivity 71% [95% CI 61-80%]; specificity, 77% [95% CI 65-86%]). Meta-regression analyses revealed that the sensitivity of CSA could be higher for differentiating full-thickness RCTs and normal patients. Furthermore, the specificity of CSA could be higher using a cut-off value of 35°. CONCLUSION: CSA on plain radiographs has good diagnostic performance for RCTs. A cut-off value of 35° is recommended for more accurate diagnosis of full-thickness RCTs. Measuring CSA on plain radiographs may provide clinicians with a readily available and reliable method for detecting RCT in daily practice. LEVEL OF EVIDENCE: Diagnostic studies, Level III.

Optical properties of the crumpled pattern of selectively layered MoS2.

Crumple-structured two-dimensional MoS2 was evaluated as an essential element for future optoelectronic and stretchable devices owing to its interesting optical properties. This Letter reports the characteristics of the crumpled structure of MoS2 directly layered on a MoS2 sheet by chemical vapor deposition. The crumpling structure is presented as a method for selectively layering MoS2 with crumpled layered patterning and tunable optical properties as a crumpled structure on a single substrate. Optical analysis by the fast Fourier transform revealed the distribution characteristics of the crumple structure, and a Raman, photoluminescence, and optical absorption analysis confirmed the change in peak shift and intensity according to the degree of the crumpled structure. This material has potential future optoelectronic applications.

Formulae Evaluation for Estimating Body Surface Area of Korean Children.

Body surface area (BSA) is an important parameter in the conduct of human exposure studies and in clinical processes in children. The aim of this paper was to compare seven BSA formulas and to find out which of these formulas is appropriate for use with Korean children. Body surface area was calculated according to age, age-group and BMI-group using the height and weight data of Korean children (n = 4899) ages 1 to 18 from Korea National Health and Nutrition Examination Survey (2012-2014). We used the formulas of Banerjee and Bhattacharya (1961), Fujimoto and Watanabe (1969), US EPA (1985), Gehan and George (1970), Boyd (1935), Haycock et al (1978) and Mosteller (1987). The average values of the seven formulas were calculated and used as norm values for comparison. All predictions showed a strong positive correlation with the overall average BSA values. Overestimations were observed on the calculations of Gehan and George (1970), US EPA (1985) and Boyd (1935) formulas. Banerjee and Bhattacharya (1961) and Fujimoto and Watanabe (1969) values showed underestimations and the largest error size of 0.027 m2 for all ages. BSA estimates of Mosteller (1987) and Haycock et al (1978) were found to be closer to the overall average BSA values with the least error size of 0.004 m2. Mosteller's formula is recommended for use in the conduct of human exposure studies and in clinical practice among Korean children, although Haycock et al formula is appropriate for children from 1 to 2 years old.

Clinical Outcome of Posterior Cruciate Ligament Reconstruction With and Without Remnant Preservation.

PURPOSE: The purpose of this study was to analyze clinical outcomes in patients who underwent posterior cruciate ligament reconstruction (PCLR) with and without remnant preservation. METHODS: A search of the literature was performed with the established medical databases Medline, Embase, and the Cochrane Register. Two authors screened the selected articles for title, abstract, and full text in accordance with predefined inclusion and exclusion criteria. The inclusion criteria were as follows: English-language articles on isolated posterior cruciate ligament injury; clinical trials with a clear description of surgical technique; outcome evaluation using a well-defined knee score, arthrometry, and posterior stress radiography; follow-up longer than 2 years; and a Coleman Methodology Score (CMS) of 65 points or greater. The methodologic quality of all articles was assessed by 2 authors according to the CMS. RESULTS: Eleven studies were included, with a mean CMS of 78.9 points (SD, 5.37 points). There was no direct comparative study between remnant-preserving PCLR and standard PCLR. At final follow-up, the knees of 72% to 100% of patients who underwent remnant-preserving PCLR and 41% to 95% of patients who underwent standard PCLR were rated as normal or nearly normal on the International Knee Documentation Committee subjective knee assessment. Patients who underwent remnant-preserving PCLR showed an increase of 16.4 to 47 points in Lysholm scores, and patients who underwent standard PCLR showed an increase of 22 to 29 points. The ranges of mean postoperative side-to-side differences on KT-1000 (MEDmetric, San Diego, CA) testing were 0.7 to 2.8 mm in patients who underwent remnant-preserving PCLR and 1 to 3.5 mm in patients who underwent standard PCLR. The ranges of mean postoperative side-to-side differences on stress radiography were 2.2 to 5 mm in patients who underwent remnant-preserving PCLR and 4.7 to 6 mm in patients who underwent standard PCLR. CONCLUSIONS: All studies on PCLR with remnant preservation showed satisfactory outcomes despite using numerous surgical techniques, graft types, intervals from injury to surgery, and follow-up periods. LEVEL OF EVIDENCE: Level IV, systematic review of Level II through IV studies.

Thermal Dehydrogenation Impact on Positive Bias Stability of Amorphous InSnZnO Thin-Film Transistors.

Recently, the growing demand for amorphous oxide semiconductor thin-film transistors (AOS TFTs) with high mobility and good stability to implement ultrahigh-resolution displays has made tracking the role of hydrogen in oxide semiconductor films increasingly important. Hydrogen is an essential element that contributes significantly to the field effect mobility and bias stability characteristics of AOS TFTs. However, because hydrogen is the lightest atom and has high reactivity to metal and oxide materials, elucidating its impact on AOS thin films has been challenging. Therefore, in this study, we propose controlling the hydrogen quantities in amorphous InSnZnO (a-ITZO) thin films through thermal dehydrogenation to precisely reveal the hydrogen influences on the electrical characteristics of a-ITZO TFTs. The as-deposited device containing 15.69 × 1015 atoms/cm2 of hydrogen exhibited a relatively low saturation mobility of 18.1 cm2/V·s and poor positive bias stress stability. However, depending on the extent of thermal dehydrogenation, not only did the hydrogen quantity and interface defect density (DIT) decrease but also the conductivity and surface energy increased due to the rise in oxygen vacancies and hydroxyl groups in a-ITZO thin films. As a result, the a-ITZO TFT with a hydrogen amount of 4.828 × 1015 atoms/cm2 showed that the saturation mobility improved up to 36.8 cm2/V·s, and positive bias stress stability was remarkably enhanced. Hence, we report the ability to manage the hydrogen quantity with thermal dehydrogenation and demonstrate that high-performance a-ITZO TFTs can be realized when an appropriate hydrogen concentration is achieved.

Highly Conductive Ink Based on Self-Aligned Single-Walled Carbon Nanotubes through Inter-Fiber Sliding in Cellulose Fibril Networks.

Carbon nanotubes (CNTs), owing to their superior electrical and mechanical properties, are a promising alternative to nonmetallic electrically conducting materials. In practice, cellulose as a low-cost sustainable matrix has been used to prepare the aqueous dispersion of cellulose-CNT (C-CNT) nanocomposites. However, the compatibility with conventional solution-processing and structural rearrangement for improving conductivity has yet to be determined. Herein, a straightforward route to prepare a conductive composite material from single-walled CNTs (SWCNTs) and natural pulp is reported. High-power shaking realizes the self-alignment of individual SWCNTs in a cellulose matrix, resulting from the structural change in molecular orientations owing to countless collisions of zirconia beads in the aqueous mixture. The structural analysis of the dried C-CNT films confirms that the entanglement and dispersion of C-CNT nanowires determine the mechanical and electrical properties. Moreover, the rheological behavior of C-CNT inks explains their coating and printing characteristics. By controlling shaking time, the electrical conductivity of the C-CNT films with only 9 wt.% of SWCNTs from 0.9 to 102.4 S cm-1 are adjusted. the optimized C-CNT ink is highly compatible with the conventional coating and printing processes on diverse substrates, thus finding potential applications in eco-friendly, highly flexible, and stretchable electrodes is also demonstrated.

Synthesis of high-voltage cathode material using the Taylor-Couette flow-based co-precipitation method.

LiNi0.5Mn1.5O4 (LNMO), a next-generation high-voltage battery material, is promising for high-energy-density and power-density lithium-ion secondary batteries. However, rapid capacity degradation occurs due to problems such as the elution of transition metals and the generation of structural distortion during cycling. Herein, a new LNMO material was synthesized using the Taylor-Couette flow-based co-precipitation method. The synthesized LNMO material consisted of secondary particles composed of primary particles with an octahedral structure and a high specific surface area. In addition, the LNMO cathode material showed less structural distortion and cation mixing as well as a high cyclability and rate performance compared with commercially available materials.

Radiolucent Pure Matrix Stones on Computed Tomography Scan, Arising in Patient with Type I Diabetes and Chronic Kidney Disease: A Case Report.

Kidney matrix stones are a rare form of calculi, which are challenging to diagnose. Matrix stones consist of a proteinaceous material which has a radiolucent appearance that might be overlooked on imaging. Recently, endourological intervention has been the standard treatment method for matrix stones. We report a case of urinary matrix stones in a patient with type 1 diabetes mellitus and chronic kidney disease, in whom the stones formed into a pure matrix and were not visualized in the computed tomography scan. The stones were found after additional work-up, and they were managed using a transureteral stone basket, not through endourological intervention.

Effect of a self-assembling La2(Ni0.5Li0.5)O4 and amorphous garnet-type solid electrolyte composite on a layered cathode material in all-solid-state batteries.

In this article, we report the effect of a Li6.75La3Zr2Al0.25O12 (LLZAO) composite Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) cathode material on the performance of all-solid-state batteries (ASSBs) with oxide-based organic/inorganic hybrid solid electrolytes. The layered structure of Ni-rich cathode material Li(Ni x Co(1-x)/2Mn(1-x)/2)O2 (x > 0.6) (NCM) exhibiting a high specific capacity is among the suitable cathode materials for next-generation energy storage systems, particularly electric vehicles and portable devices for all-solid-state batteries. However, the ASSBs present a problem-the resistance at the interface between a cathode and solid electrolyte is larger than that with a liquid electrolyte because of point contact. To solve this problem, using a simultaneous co-precipitation method, we composited various amounts of LLZAO material and an ion conducting material on the cathode material's surface. Therefore, to optimize the value of the LLZAO material in the composite cathode material, the structure, cycling stability, and rate performance of the NCM-LLZAO composite cathode material in ASSBs with oxide-based inorganic/organic-hybrid electrolytes were investigated using powder X-ray diffraction analysis, field-emission scanning electron microscopy, electrochemical impedance spectroscopy, and galvanostatic measurements.

Vacuum-free solution-based metallization (VSM) of a-IGZO using trimethylaluminium solution.

This research demonstrates a method to reduce the resistance of amorphous indium-gallium-zinc-oxide (a-IGZO) using a "vacuum-free solution-based metallization" (VSM) process, which revolutionizes the metallization process thanks to its simplicity, by simply dipping the a-IGZO into trimethyl aluminium (TMA, (CH3)3Al) solution. From the XPS results, it was found that oxygen vacancies were generated after the VSM process, resulting in the enhanced conductivity. Various metallization time and solution temperature conditions were investigated, and the measured conductivity of the a-IGZO could be enhanced up to 20.32 S cm-1, which is over 105 times larger compared to that of the untreated a-IGZO. By utilizing the VSM process, self-aligned top-gate (SATG) a-IGZO thin-film-transistors (TFTs) were successfully fabricated, and to provide an explanation for the mechanism, X-ray photoelectron spectroscopy (XPS) was employed.

The effects of age, viewing distance, display type, font type, colour contrast and number of syllables on the legibility of Korean characters.

This study evaluated the effects of age (20s and 60s), viewing distance (50 cm, 200 cm), display type (paper, monitor), font type (Gothic, Ming), colour contrast (black letters on white background, white letters on black background) and number of syllables (one, two) on the legibility of Korean characters by using the four legibility measures (minimum letter size for 100% correctness, maximum letter size for 0% correctness, minimum letter size for the least discomfort and maximum letter size for the most discomfort). Ten subjects in each age group read the four letters presented on a slide (letter size varied from 80 pt to 2 pt). Subjects also subjectively rated the reading discomfort of the letters on a 4-point scale (1 = no discomfort, 4 = most discomfort). According to the ANOVA procedure, age, viewing distance and font type significantly affected the four dependent variables (p < 0.05), while the main effect of colour contrast was not statistically significant for any measures. Two-syllable letters had smaller letters than one-syllable letters in the two correctness measures. The younger group could see letter sizes two times smaller than the old group could and the viewing distance of 50 cm showed letters about three times smaller than those at a 200 cm viewing distance. The Gothic fonts were smaller than the Ming fonts. Monitors were smaller than paper for correctness and maximum letter size for the most discomfort. From a comparison of the results for correctness and discomfort, people generally preferred larger letter sizes to those that they could read. The findings of this study may provide basic information for setting a global standard of letter size or font type to improve the legibility of characters written in Korean. STATEMENT OF RELEVANCE: Results obtained in this study will provide basic information and guidelines for setting standards of letter size and font type to improve the legibility of characters written in Korean. Also, the results might offer useful information for people who are working on design of visual displays.

Ergonomic evaluation of three types of inner-room floor mats by using in-shoe and platform type pressure measurement systems.

Prolonged work in upright postures (standing and walking) is common in industry and in daily living activities, and is one possible risk factor for low back pain and leg problems. This study compared the reaction forces of four different floor surface conditions (three inner-room floor mats and no-mat) during gait. The reaction forces were measured by both the in-shoe and platform type pressure measurement systems. Six male subjects (average weight = 72.4 +/- 7.5 kg) walked barefoot on the four floor conditions and the data from the two measurement systems were recorded simultaneously. The mean reaction force, two peak forces (heel strike and toe off), and the maximum reaction force measured by the in-shoe type system showed significantly different values according to the floor surface conditions (P < 0.05). The no-mat condition induced the largest mean reaction force of 828.9 +/- 114.2 N, However there was no difference in the reaction forces measured from the platform type system (P > 0.05). All three floor mats induced smaller reaction forces than no-mat, but the mean reaction force and maximum reaction forces (maximum and two peak forces) showed different results due to different thickness and materials. Thus, an appropriate selection of inner-room floor mat according to the biomechanical properties may be useful for reduction of fatigue and discomfort in industrial settings.

Lithium-ion transport in inorganic active fillers used in PEO-based composite solid electrolyte sheets.

In this study, we evaluated the properties exhibited by a composite solid electrolyte (CSE) prepared via tailoring the particle size of an active filler, Li6.4La3Zr1.4Ta0.6O12 (LLZTO). The average particle size was reduced to 2.53 µm via ball milling and exhibited a specific surface area of 3.013 m2 g-1. Various CSEs were prepared by combining PEO and LLZTO/BM-LLZTO. The calculated lithium ionic conductivity of the BM-LLZTO CSE was 6.0 × 10-5 S cm-1, which was higher than that exhibited by the LLZTO CSE (4.6 × 10-5 S cm-1). This result was confirmed via 7Li nuclear magnetic resonance (NMR) analysis, during which lithium-ion transport pathways varied as a function of the particle size. NMR analysis showed that when BM-LLZTO was used, the migration of Li ions through the interface occurred at a fast rate owing to the small size of the constituent particles. During the Li/CSEs/Li symmetric cell experiment, the BM-LLZTO CSE exhibited lower overvoltage characteristics than the LLZTO CSE. A comparison of the characteristics exhibited by the LFP/CSEs/Li cells confirmed that the cells using BM-LLZTO exhibited high discharge capacity, rate performance, and cycling stability irrespective of the CSE thickness.

Synaptic transistors based on a tyrosine-rich peptide for neuromorphic computing.

In this article, we propose an artificial synaptic device based on a proton-conducting peptide material. By using the redox-active property of tyrosine, the Tyr-Tyr-Ala-Cys-Ala-Tyr-Tyr peptide film was utilized as a gate insulator that shows synaptic plasticity owing to the formation of proton electric double layers. The ion gating effects on the transfer characteristics and temporal current responses are shown. Further, timing-dependent responses, including paired-pulse facilitation, synaptic potentiation, and transition from short-term plasticity to long-term plasticity, have been demonstrated for the electrical emulation of biological synapses in the human brain. Herein, we provide a novel material platform that is bio-inspired and biocompatible for use in brain-mimetic electronic devices.

Four Cases of Carbapenem-Resistant Enterobacteriaceae Infection from January to March in 2014.

Infection with carbapenem-resistant Enterobacteriaceae (CRE) and other multidrug resistant bacteria has increased rapidly in Korea. The Korea Centers for Disease Control and Prevention reported 1,609 cases of CRE infection in the country in 2013. The risk factors for CRE infection include history of treatment with antibiotics such as cephalosporins or carbapenem, trauma, diabetes, cancer, and history of ventilator support. Herein, we report four cases of CRE infection seen during a 3-month period in our hospital in 2014. CRE infection is associated with a high mortality rate of 30% to 50%, even with combination antibiotic therapy. Prevention of CRE infection in hospital settings is fundamental to controlling its transmission. Key preventive measures include, contact precautions, hand hygiene, education of healthcare personnel, screening for CRE when indicated, and exercising discretion in prescribing carbapenem or cephalosporins.