Search

Improper acetabulum component position is a significant risk factor for postoperative dislocation after total hip arthroplasty. Several radiographic two‐dimensional methods exist for measuring acetabulum component anteversion, but they cannot distinguish between anteversion and retroversion. "Liaw's version," initially proposed as a simple mathematical standardized two‐dimensional method, was modified to the computerized ellipse method, proving superior accuracy to traditional two‐dimensional methods. In this article, we demonstrated its application in detecting and measuring retroverted acetabulum component. We obtained anteroposterior pelvis radiographs from a patient undergoing total hip arthroplasty on the day of surgery and 2 weeks postoperatively. The computerized ellipse method was used to measure the acetabulum component orientation. Upon comparison, the difference between θ assigned to be retroverted (9.52–8.56 = 0.96) is much smaller than the difference between θ assigned to be anteverted (23.81–18.86 = 4.95), leading us to determine retroversion. This was further confirmed by computed tomography at the 6‐week follow‐up. We propose that using the computerized ellipse method to measure Liaw's version can be a valuable tool in identifying acetabulum component retroversion on anteroposterior radiographs during routine postoperative follow‐up and retrospective assessments of total hip arthroplasty patients. [ABSTRACT FROM AUTHOR]

Objective: Tongue strength is crucial for safe and efficient oropharyngeal swallowing. This study examined the effect of tongue-to-palate resistance training (TPRT) on anterior and posterior tongue strength by conducting a prospective, randomized, parallel allocation trial.Methods: Ninety-one healthy adults were recruited in this study and were randomly assigned to an experimental group (n = 44) or a control group (n = 47). The experimental group performed TPRT for 8 weeks (5 days per week), whereas the control group performed the usual daily activities. Tongue strength was measured using the Iowa Oral Performance Instrument (IOPI) before and after the practice program was conducted at weeks 2, 4, 6, and 8, to evaluate the feasibility of the developed training protocol.Results: This experimental group demonstrated more improvements in both anterior tongue strength (p < .05) and posterior tongue strength (p < .05). The positive effects of the intervention on tongue strength appeared at 8 weeks for the anterior region and 2 weeks for the posterior region.Conclusions: These findings illustrate that TPRT can improve tongue strength. It is suggested that people integrate this exercise protocol into their daily life, positive change in tongue strength may prevent or halt presbyphagia. [ABSTRACT FROM AUTHOR]

Abstract: Herein, a novel orthogonal lithography process is reported to pattern all‐inorganic perovskite CsPbX3 (X = Cl, Br, I) quantum dot (QD) arrays which cannot be patterned with traditional approaches. This approach involves a combination of fluorinated polymer and solvent to resolve issues of polar–nonpolar solvent constraints thus enabling the fabrication of complex patterns with high optical gain and multicolor emission. This approach is utilized to fabricate high‐resolution large‐area arrays of microdisk lasers and multicolor (binary and ternary emission) pixels. The optical cavity modes of CsPbBr3 QD microdisk lasers are readily controlled by tuning the disk size, where the mode spacing decreases while the number of modes increases with increasing disk diameter. Finally, the versatility of this approach for the integration of environmentally sensitive QDs with different emission signatures and composition on the same chip, while achieving high‐density, high‐resolution large‐area QD arrays with multicolor pixels, is demonstrated. [ABSTRACT FROM AUTHOR]

This work examines how the optimization of molecular dimensions and chemical functionality of the organic ligands of quantum dots (QDs) can be explored for dramatic enhancement of the optical properties of QD films, particularly, optical gain. We show that the replacement of traditional QD organic ligands with a much shorter ligand, butylamine, yields a dense QD-packing that results in a two-fold increase in optical gain. Overall, the highly packed QD films exhibit very large net gain values (∼500 cm−1) which greatly exceed typical Cd-based QD films with traditional ligands. In addition, thresholds for amplified-spontaneous emission (ASE) down to 50 μJ cm−2 were observed, which is exceptionally low for ns-pulse pumped QD systems. Our results confirm an additional route for obtaining high optical gain using QDs, and outline a strategy for modifying the optical gain characteristics by ligand exchange without needing to modify the QD selection. Consideration of the ligands along with QD compositional design could make it possible to fabricate photonic systems with exceptionally low lasing thresholds, and offers a route toward achieving high gain using steady state pumping, an extremely difficult feat to achieve in traditional QD systems. [ABSTRACT FROM AUTHOR]

The key to utilizing quantum dots (QDs) as lasing media is to effectively reduce non-radiative processes, such as Auger recombination and surface trapping. A robust strategy to craft a set of CdSe/Cd1− xZn xSe1− yS y/ZnS core/graded shell-shell QDs with suppressed re-absorption, reduced Auger recombination rate, and tunable Stokes shift is presented. In sharp contrast to conventional CdSe/ZnS QDs, which have a large energy level mismatch between CdSe and ZnS and thus show strong re-absorption and a constrained Stokes shift, the as-synthesized CdSe/Cd1− xZn xSe1− yS y/ZnS QDs exhibited the suppressed re-absorption of CdSe core and tunable Stokes shift as a direct consequence of the delocalization of the electron wavefunction over the entire QD. Such Stokes shift-engineered QDs with suppressed re-absorption may represent an important class of building blocks for use in lasers, light emitting diodes, solar concentrators, and parity-time symmetry materials and devices. [ABSTRACT FROM AUTHOR]

A facile one‐step fabrication of large‐area multicolored emissive photopatterns in mixed quantum dot‐polymer films is demonstrated. This is in sharp contrast to the current photopatterning approaches that utilize only a single quantum dot (QD) component for single‐color patterns. Strategies are presented that allow for either selective or collective modification of specific predetermined photoluminescent peaks of green and red QDs during photopattern development. These strategies yield novel patterns and allow for unprecedented control over how the color contrast of the photopattern evolves with continuous light illumination. These results clearly show that the evolution of the emission spectra of a multicolor mixed QD‐polymer film can be readily tailored during pattern development, either by careful selection of the excitation wavelength or through combinations of controllably unstable and stable QDs with different recovery rates. Notably, these strategies are simple, fast, and robust, yielding high‐resolution microscopic patterns over large areas (up to fractions of a cm2). Furthermore, the flexibility and capabilities of these strategies greatly expand the potential applications of multicolor emissive photopatterns, particularly in the areas of sensing, imaging, and lasing systems where it is important to exert delicate control over the intensity of selected colors within specific spatial regions. [ABSTRACT FROM AUTHOR]

In recent years, fast economic growth and rapid technology advance have led to significant impact on the quality of traditional transport system. Intelligent transportation system (ITS), which aims to improve the transport system, has become more and more popular. Furthermore, improving the safety of traffic is an important issue of ITS, and the pothole on the road causes serious harm to drivers’ safety. Therefore, drivers’ safety may be improved with the establishment of real-time pothole detection system for sharing the pothole information. Moreover, using the mobile device to detect potholes has been more popular in recent years. This approach can detect potholes with lower cost in a comprehensive environment. This study proposes a pothole detection method based on the mobile sensing. The accelerometer data is normalized by Euler angle computation and is adopted in the pothole detection algorithm to obtain the pothole information. Moreover, the spatial interpolation method is used to reduce the location errors from global positioning system (GPS) data. In experiments, the results show that the proposed approach can precisely detect potholes without false-positives, and the higher accuracy is performed by the proposed approach. Therefore, the proposed real-time pothole detection approach can be used to improve the safety of traffic for ITS. [ABSTRACT FROM AUTHOR]

In response to the call for a physiologically-friendly light at night that shows low color temperature, a candle light-style organic light emitting diode (OLED) is developed with a color temperature as low as 1900 K, a color rendering index (CRI) as high as 93, and an efficacy at least two times that of incandescent bulbs. In addition, the device has a 80% resemblance in luminance spectrum to that of a candle. Most importantly, the sensationally warm candle light-style emission is driven by electricity in lieu of the energy-wasting and greenhouse gas emitting hydrocarbon-burning candles invented 5000 years ago. This candle light-style OLED may serve as a safe measure for illumination at night. Moreover, it has a high color rendering index with a decent efficiency. [ABSTRACT FROM AUTHOR]

We demonstrate herein the design and fabrication of a highly efficient yellow organic light-emitting diode (OLED) with a balanced carrier injection device architecture having a zero electron-injection-barrier host blended with a hole-injection aiding co-host. The resultant yellow OLED showed, at 1000 cd m−2 for example, an efficacy of 59 lm W−1, current efficiency of 71 cd A−1 and external quantum efficiency (EQE) of 23%, with values of 42 lm W−1, 47 cd A−1 and 15% EQE without a co-host. The co-host effect that resulted in very balanced carrier injection was also valid for other yellow OLED devices and their efficiency improvement was also very marked. With the use of a micro-lens, the device efficiency is further improved to 79 lm W−1, 96 cd A−1 and 30% EQE. [ABSTRACT FROM AUTHOR]

Low color temperature (CT) lighting sources are crucial for their low suppression of melatonin secretion, and high power efficiency is essential for energy-saving. This study demonstrates the incorporation of a blend interlayer between emissive layers to improve the device performance of low CT organic light emitting diodes. The resulting devices exhibit a CT much lower than that of incandescent bulbs, which is ∼2500 K with a ∼15 lm W−1efficiency, and even as low as that of candles, which is ∼2000 K with ∼0.1 lm W−1. The best device fabricated shows an external quantum efficiency of 22.7% and 36 lm W−1(54 cd A−1) with 1880 K at 100 cd m−2, or 20.8% and 29 lm W−1(50 cd A−1) with 1940 K at 1000 cd m−2. The high efficiency of the proposed device may be attributed to its interlayer, which helps effectively distribute the entering carriers into the available recombination zones. [ABSTRACT FROM AUTHOR]

Nitroxide polymer brushes were covalently patterned on flexible conducting substrates viasurface-initiated atom transfer radical polymerization and microcontact printing. As a cathode of organic radical batteries, the nitroxide polymer brushes prevent the nitroxide polymer from dissolving into electrolyte solvents, which improves the cycle-life performance of batteries. [ABSTRACT FROM AUTHOR]

Since their inception, quantum dots have proven to be advantageous for light management applications due to their high brightness and well‐controlled absorption, scattering, and emission properties. As quantum dots become commercially available at large scale, the need for robust, stable, and flexible optical components continues to drive the development of robust and flexible quantum dot composite materials. In this review, after a thorough introduction to quantum dots, discussion delves into methods for fabricating quantum dot loaded composite optical elements such as thin films, microfabricated patterns, and microstructures. The importance of surface chemistry and ligand engineering, host matrixes, wet processing, and unique patterning methodologies is presented by considering photostability, aggregation, and phase separation of quantum dots in corresponding composites. With regard to prospective optical applications of quantum dot materials, emphasis is placed on light emitting and guiding composite materials for lasing applications, specifically whispering gallery mode‐based photonic microsystems. These developments will enable novel flexible, portable, and miniaturized optoelectronic devices such as light‐emitting diodes, flexible pixelated displays, solar cells, large‐area microwaveguides, omnidirectional micromirrors, optical metasurfaces, and directional microlasers. Herein the state of the art of quantum dot composite materials is described, with particular interest paid to light emitting and guiding technologies. Great attention is paid to micropatterning, focusing on the importance of surface chemistry and ligand engineering, host matrixes, and wet processing to achieve optimal photostability, aggregation, and phase separation of quantum dots in corresponding patterns and resulting devices. [ABSTRACT FROM AUTHOR]

We demonstrate the feasibility of using direct contact-printing in the fabrication of monochromatic and polychromatic organic light-emitting diodes (OLEDs). Bright devices with red, green, blue, and white contact-printed light-emitting layers with a respective maximum luminance of 29 000, 29 000, 4000, and 18 000 cd/m2 were obtained with sound film integrity by blending a polymeric host into a molecular host. For the red OLED as example, the maximum luminance was decreased from 29 000 to 5000 cd/m2 as only the polymeric host was used, or decreased to 7000 cd/m2 as only the molecular host was used. The markedly improved device performance achieved in the devices with blended hosts may be attributed to the employed polymeric host that contributed a good film-forming character, and the molecular host that contributed a good electroluminescence character. [ABSTRACT FROM AUTHOR]

Abstract: The deposition of Al2O3 on LiCoO2 electrodes using a low-temperature atomic layer deposition has been investigated. Scanning electron microscopy confirms that Al2O3 films can be homogeneously deposited on LiCoO2 particles of porous electrodes at 120°C. The results of X-ray photoelectron spectroscopy show that the Al2O3 preferentially deposits on the LiCoO2. Furthermore, the results of cycling stability tests show that the cells with Al2O3-coated LiCoO2 electrodes have enhanced performance. [Copyright &y& Elsevier]

The past few years have witnessed rapid advances in the synthesis of high-quality perovskite nanocrystals (PNCs). However, despite the impressive developments, the stability of PNCs remains a substantial challenge. The ability to reliably improve stability of PNCs while retaining their individual nanometer size represents a critical step that underpins future advances in optoelectronic applications. Here, we report an unconventional strategy for crafting dual-shelled PNCs (i.e., polymer-ligated perovskite/SiO 2 core/shell NCs) with exquisite control over dimensions, surface chemistry, and stabilities. In stark contrast to conventional methods, our strategy relies on capitalizing on judiciously designed star-like copolymers as nanoreactors to render the growth of core/shell NCs with controlled yet tunable perovskite core diameter, SiO 2 shell thickness, and surface chemistry. Consequently, the resulting polymer-tethered perovskite/SiO 2 core/shell NCs display concurrently a stellar set of substantially improved stabilities (i.e., colloidal stability, chemical composition stability, photostability, water stability), while having appealing solution processability, which are unattainable by conventional methods., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

We report a simple, robust, and inexpensive strategy to enable all-inorganic CsPbX 3 perovskite nanocrystals (NCs) with a set of markedly improved stabilities, that is, water stability, compositional stability, phase stability, and phase segregation stability via impregnating them in solid organic salt matrices (i.e., metal stearate; MSt). In addition to acting as matrices, MSt also functions as the ligand bound to the surface of CsPbX 3 NCs, thereby eliminating the potential damage of NCs commonly encountered during purification as in copious past work. Quite intriguingly, the resulting CsPbX 3 -MSt nanocomposites display an outstanding suite of stabilities. First, they retain high emission in the presence of water because of the insolubility of MSt in water, signifying their excellent water stability. Second, anion exchange between CsPbBr 3 -MSt and CsPbI 3 -MSt nanocomposites is greatly suppressed. This can be ascribed to the efficient coating of MSt, thus effectively isolating the contact between CsPbBr 3 and CsPbI 3 NCs, reflecting notable compositional stability. Third, remarkably, after being impregnated by MSt, the resulting CsPbI 3 -MSt nanocomposites sustain the cubic phase of CsPbI 3 and high emission, manifesting the strikingly improved phase stability. Finally, phase segregation of CsPbBr 1.5 I 1.5 NCs is arrested via the MSt encapsulation (i.e., no formation of the respective CsPbBr 3 and CsPbI 3 ), thus rendering pure and stable photoluminescence (i.e., demonstration of phase segregation stability). Notably, when assembled into typical white light-emitting diode architecture, CsPbBr 1.5 I 1.5 -MSt nanocomposites exhibit appealing performance, including a high color rendering index ( R a ) and a low color temperature ( T c ). As such, the judicious encapsulation of perovskite NCs into organic salts represents a facile and robust strategy for creating high-quality solid-state luminophores for use in optoelectronic devices.

This article reports for the time-resolved photophysical studies of spirally configured ( cis-stilbene) trimers and their spin-coated organic light-emitting diode (OLED) device performances. Transient absorption profiles of spirally configured, ter-( cis-stilbene) were studied by pulse radiolysis. The emission profiles after charge recombination of their incipient radical ions in benzene provides insights into the emission mechanism and efficiency in OLED devices. Blue-, sky blue-, and green-emitting OLED devices for a maximum external quantum efficiency are 4.32%, 4.70%, and 2.77%, respectively, by solution process.

This work demonstrates a facile and versatile method for generating low scattering cross-linked quantum dot (QD)-polymer composite films and patterned highly emissive structures with ultrahigh QD loading, minimal phase separation, and tunable mechanical properties. Uniform QD-polymer films are fabricated using thiol-ene chemistry, in which cross-linked polymer networks are rapidly produced in ambient conditions via fast UV polymerization in bulk to suppress QD aggregation. UV-controlled thiol-ene chemistry limits phase separation through producing highly QD loaded cross-linked composites with loadings above majority of those reported in the literature (<1%) and approaching 30%. As the QD loading is increased, the thiol and ene conversion decreases, resulting in nanocomposites with widely variable and tailorable mechanical properties as a function of UV irradiation time with an elastic modulus decreasing to 1 GPa being characteristic of reinforced elastomeric materials, in contrast to usually observed stiff and brittle materials under these loading conditions. Furthermore, we demonstrate that the thiol-ene chemistry is compatible with soft-imprint lithography, making it possible to pattern highly loaded QD films while preserving the optical properties essential for high gain and low optical loss devices. The versatility of thiol-ene chemistry to produce high-dense QD-polymer films potentially makes it an important technique for polymer-based elastomeric optical metamaterials, where efficient light propagation is critical, like peculiar waveguides, sensors, and optical gain films.

Low-temperature atomic layer deposition of conformal ZnO on a self-assembled block polymer lithographic template comprising well-ordered, vertically aligned cylindrical pores within a poly(styrene) (PS) matrix was used to produce nanocrucible templates with pore diameters tunable via ZnO thickness. Starting from a PS template with a hexagonal array of 30 nm diameter pores on a 45 nm pitch, the ZnO thickness was progressively increased to narrow the pore diameter to as low as 14 nm. Upon removal of the PS by heat treatment in air at 500 °C to form an array of size-tunable ZnO nanocrucibles, permalloy (Ni80Fe20) was evaporated at normal incidence, filling the pores and creating an overlayer. Argon ion beam milling was then used to etch back the overlayer (a Damascene-type process), leaving a well-ordered array of isolated ZnO nanocrucibles filled with permalloy nanodots. Microscopy and temperature-dependent magnetometry verified the diameter reduction with increasing ZnO thickness. The largest diameter (30 nm) dots exhibit a ferromagnetic multidomain/vortex state at 300 K, with relatively weakly temperature-dependent coercivity. Reducing the diameter leads to a crossover to a single-domain state and eventually superparamagnetism at sufficiently high temperature, in quantitative agreement with expectations. We argue that this approach could render this form of block polymer lithography compatible with high-temperature processing (as required for technologically important high perpendicular anisotropy ordered alloys, for instance), in addition to enabling separation-dependent studies to probe interdot magnetostatic interactions.

Detailed experiments designed to optimize and understand the solvent vapor annealing of cylinder-forming poly(styrene)-block-poly(lactide) thin films for nanolithographic applications are reported. By combining climate-controlled solvent vapor annealing (including in situ probes of solvent concentration) with comparative small-angle X-ray scattering studies of solvent-swollen bulk polymers of identical composition, it is concluded that a narrow window of optimal solvent concentration occurs just on the ordered side of the order-disorder transition. In this window, the lateral correlation length of the hexagonally close-packed ordering, the defect density, and the cylinder orientation are simultaneously optimized, resulting in single-crystal-like ordering over 10 μm scales. The influences of polymer synthesis method, composition, molar mass, solvent vapor pressure, evaporation rate, and film thickness have all been assessed, confirming the generality of this behavior. Analogies to thermal annealing of elemental solids, in combination with an understanding of the effects of process parameters on annealing conditions, enable qualitative understanding of many of the key results and underscore the likely generality of the main conclusions. Pattern transfer via a Damascene-type approach verified the applicability for high-fidelity nanolithography, yielding large-area metal nanodot arrays with center-to-center spacing of 38 nm (diameter 19 nm). Finally, the predictive power of our findings was demonstrated by using small-angle X-ray scattering to predict optimal solvent annealing conditions for poly(styrene)-block-poly(lactide) films of low molar mass (18 kg mol(-1)). High-quality templates with cylinder center-to-center spacing of only 18 nm (diameter of 10 nm) were obtained. These comprehensive results have clear and important implications for optimization of pattern transfer templates and significantly advance the understanding of self-assembly in block copolymer thin films.

The aim of this study was to investigate Epstein-Barr virus (EBV)-related virus infection in pet dogs. The presence of antibodies to EBV antigens and EBV-related DNA was determined by Western blot analysis and PCR, respectively. Among 36 pet dogs examined for serum antibodies, 32 (88.9%) were positive for EBV-specific thymidine kinase, 15 (41.7%) for EBV-encoded DNA-binding protein and 10 (27.8%) for EBV-specific DNA polymerase. A BamHI W fragment sequence encoding part of the EBV nuclear antigen leader protein was detected by PCR in corresponding leukocyte DNA samples. Among 21 dogs tested, 15 (71.4%) were positive for the BamHI W fragment sequence. The specificity of the amplified DNA fragments was confirmed by DNA sequencing. Within the amplified region of the BamHI W fragment (241 bp), DNA sequences detected in 10 dogs had 99.2% (two nucleotide variations), 99.6% (one nucleotide variation) or 100% identity to that of EBV. Furthermore, an EBV-encoded RNA signal was detected by in situ hybridization in dog lymphocytes, as well as in bone-marrow sections, indicating a latent infection with EBV or an EBV-like virus. In conclusion, although the sample size was small, these results showed that a widespread EBV-related gammaherpesvirus could be detected in the peripheral blood and bone marrow of pet dogs. Although no evident zoonotic transmission was detected, further studies are imperative for disclosing the biological significance of this canine EBV-like virus, which may correlate with human disorders.