36 research outputs found
Nanocomb Architecture Design Using Germanium Selenide as High-Performance Lithium Storage Material
A key to improve the electrochemical performance of anode materials is to exploit the rational nanostructure designing beneficial for structural toughness and high rate capability. As a nanostructure design in accordance with this criterion, we introduced GeSe nanocomb architecture with well-developed nanocomb teeth on the backbone. In this unique nanocomb architecture, the free space between nanocomb teeth effectively alleviates tremendous volume expansion during lithiation, and anisotropic structure with a short Li+ diffusion length of tens of nanometer scale guarantees the favorable lithiation/delithiation kinetics. These structural advantages of GeSe nanocomb architecture lead to significantly improved electrochemical performance compared to the GeSe nanopowder counterpart. This GeSe nanocomb architecture exhibits electrochemical performance with the reversible capacity of 726 mA.h.g(-1), showing superior capacity retention of 89% even after 1000 cycles at 1.0 C (1.01 A.g(-1)).clos
<i>FGFR3</i> Mutations in Urothelial Carcinoma: A Single-Center Study Using Next-Generation Sequencing
Background: Mutations of fibroblast growth factor receptor 3 (FGFR3) are associated with urothelial carcinoma (UC) oncogenesis and are considered an important therapeutic target. Therefore, we evaluated the FGFR3 mutation rate and its clinical significance in urothelial carcinoma (UC) using next-generation sequencing. Methods: A total of 123 patients with UC who were treated at Chonnam National University Hospital (Gwang-ju, Korea) from January 2018 to December 2020 were enrolled. We performed NGS using the Oncomine panel with tumor specimens and blood samples corresponding to each specimen. We analyzed the FGFR3 mutation results according to the type of UC and the effects on early recurrence and progression. Results: The mean age of the patients was 71.39 ± 9.33 years, and 103 patients (83.7%) were male. Overall, the FGFR3 mutation rate was 30.1% (37 patients). The FGFR3 mutation rate was the highest in the non-muscle-invasive bladder cancer (NMIBC) group (45.1%), followed by the muscle-invasive bladder cancer (22.7%) and upper tract UC (UTUC) (14.3%) groups. Patients with FGFR3 mutations had a significantly lower disease stage (p = 0.019) but a high-risk of NMIBC (p Conclusions: Our results revealed that FGFR3 mutations were more prevalent in patients with NMIBC and lower stage UC and associated with a high-risk of NMIBC. Large multicenter studies are needed to clarify the clinical significance of FGFR3 mutations in UC
Evaluation and Optimization of an Image Acquisition System for Dual-Energy Cargo Inspections
Development and evaluation of advanced safety algorithms for excavators using virtual reality
This study focuses on the development and evaluation of advanced safety algorithms for excavators using virtual reality (VR). An excavator typically operates under a stationary state with its working parts rotating 360 degrees in coordination with nearby workers. During excavation, a fatal accident can occur due to operator carelessness and work site blind spots. Accidents due to collisions with nearby workers have been increasing. Accordingly, we presented safety system algorithms to prevent collisions with surrounding objects and secure the maximum working area in this study. We also evaluated the performance of safety system algorithms using VR. For risk assessment, we calculated the predicted working area through a kinematic analysis of the excavator's working parts and accordingly conducted target selection of risk factors. We used time-to-collision and warning indices as safety indices for the safety assessment of the selected target and divided the excavator's working modes into three categories: Safe, warning, and emergency braking modes. Control inputs, such as alarms and braking, were appropriately defined for each working mode. Under warning mode, workers can avoid collisions because a safety system will alert them of dangerous situations through an alarm. Under emergency braking mode, an emergency braking input signal is dispatched with an alarm to automatically prevent collisions. The advanced safety algorithm proposed in the study was developed in MATLAB/Simulink environment. The VR application was developed using a physics engine. On the basis of this application, the performance evaluation of the safety system algorithms was conducted on the frequently occurring sticking scenario.N
Thiol-Ligand-Catalyzed Quenching and Etching in Mixtures of Colloidal Quantum Dots and Silver Nanoparticles
Plasmonic nanostructures have the
potential to enhance the emissive
properties of semiconductor quantum dots (QDs). Although gold nanoparticles
have been widely used for this purpose, other metals, such as silver,
are also of interest and have more desirable plasmonic properties;
however, silver nanoparticles suffer from chemical instability that
gold nanoparticles do not. We find that this instability has the potential
to limit the integration of silver nanoparticles (AgNPs) with QDs.
Specifically, the common selection of thiol ligands for colloidal
stabilization of QDs is incompatible with AgNPs, whether silver nanospheres
or silver nanoplates. Equilibrium desorption of thiol ligands from
QDs drives a pseudocatalytic process wherein the AgNPs are etched
to produce silver(I)–ligand complexes, which then undergo cation
exchange reactions at the QD leading to quenching of its photoluminescence
(PL) through the introduction of long-lived trap states. We characterize
this process through a combination of morphological, chemical, and
steady-state and time-resolved spectroscopic measurements. The latter
include extinction and absorption, PL emission intensity and lifetime,
and transient absorption. Importantly, the etching and quenching process
is avoided with QDs that are coated with an amphiphilic polymer instead
of thiol ligands
Collision efficiency factor in Brownian coagulation for unstable and stable suspension including hydrodynamics and interparticle forces
A Dual-Band 47-dB Dynamic Range 0.5-dB/Step DPA with Dual-Path Power-Combining Structure for NB-IoT
This paper presents a digital power amplifier (DPA) with a 43-dB dynamic range and 0.5-dB/step gain steps for a narrow-band Internet of Things (NBIoT) transceiver application. The proposed DPA is implemented in a dual-band architecture for both the low band and high band of the frequency coverage in an NBIoT application. The proposed DPA is implemented in two individual paths, power amplification, and power attenuation, to provide a wide range when both paths are implemented. To perform the fine control over the gain steps, ten fully differential cascode power amplifier cores, in parallel with a binary sizing, are used to amplify power and enable signals and provide fine gain steps. For the attenuation path, ten steps of attenuated signal level are provided which are controlled with ten power cores, similar to the power amplification path in parallel but with a fixed, small size for the cores. The proposed implementation is finalized with output custom-made baluns at the output. The technique of using parallel controlled cores provides a fine power adjustability by using a small area on the die where the NBIoT is fabricated in a 65-nm CMOS technology. Experimental results show a dynamic range of 47 dB with 0.5-dB fine steps are also available
Delivery of recombinant <i>EGFP</i> DNA into the macrophage cell line, J774A.1, via rSmeg using the pMyong2-EGFP<sup>e</sup> shuttle vector.
<p>GFP expression in rSmeg harboring the pMyong2-EGFP<sup>e</sup> vector was observed using (A and B) fluorescence and (C and D) confocal microscopy. A FACS analysis of the GFP expression in <i>M</i>. <i>smegmatis</i> harboring (E, F, and G) pMyong2-TOPO and (H, I, and J) pMyong2-EGFP<sup>e</sup> at 10, 50, and 100 M.O.I., respectively.</p