In Vivo Imaging of the Tumor‐Associated Enzyme NCEH1 with a Covalent PET Probe

Herein, we report the development of an ¹⁸F‐labeled, activity‐based small‐molecule probe targeting the cancer‐associated serine hydrolase NCEH1. We undertook a focused medicinal chemistry campaign to simultaneously preserve potent and specific NCEH1 labeling in live cells and animals, while permitting facile ¹⁸F radionuclide incorporation required for PET imaging. The resulting molecule, [¹⁸F]JW199, labels active NCEH1 in live cells at nanomolar concentrations and greater than 1000‐fold selectivity relative to other serine hydrolases. [¹⁸F]JW199 displays rapid, NCEH1‐dependent accumulation in mouse tissues. Finally, we demonstrate that [¹⁸F]JW199 labels aggressive cancer tumor cells in vivo, which uncovered localized NCEH1 activity at the leading edge of triple‐negative breast cancer tumors, suggesting roles for NCEH1 in tumor aggressiveness and metastasis.     

AQP4 Attenuated TRAF6/NFκB Activation in Acrylamide-Induced Neurotoxicity

Acrylamide (ACR) is present in high-temperature-processed high-carbohydrate foods, cigarette smoke, and industrial pollution. Chronic exposure to ACR may induce neurotoxicity from reactive oxygen species (ROS); however, the mechanisms underlying ACR-induced neurotoxicity remain unclear. We studied 28-day subacute ACR toxicity by repeatedly feeding ACR (0, 15, or 30 mg/kg) to rats. We conducted RNA sequencing and Western blot analyses to identify differences in mRNA expression in the blood and in protein expression in the brain tissues, respectively, of the rats. AQP4 transient transfection was performed to identify potential associations with protein regulation. The rats treated with 30 mg/kg ACR exhibited hind-limb muscle weakness. Matrix metalloproteinase (MMP9) expression was higher in the ACR-treated group than in the control group. ACR induced MMP-9 and AQP4 protein expression in the brain tissues of the rats, which subsequently presented with neurotoxicity. In the in vitro study, Neuro-2a cells were transiently transfected with AQP4, which inhibited MMP-9 and TNF receptor-associated factor 6 (TRAF6) expression, and inhibited ACR induced expression of TRAF6, IκBα, and nuclear factor κB (NFκB). Using a combination of in vivo and in vitro experiments, this study revealed that depressive symptoms associated with ACR-induced neurotoxicity are associated with downregulation of AQP4 and induction of the TRAF6 pathway.     

Carbon Encapsulation of High Entropy Alloy Nanoparticles with Extraordinary Coercivity and Saturation at Room Temperature

Owing to their unique properties and technological potential, high entropy alloys (HEAs) have become the subject of great interest in the materials science community. HEAs consist of more than four principle elements in equimolar ratio so their configurational entropy is intrinsically greater than one-principle element based. The increasing surface energy and chemical tendency toward clustering of like atoms at low dimension, however, make production of HEA-nanoparticles (HEA-NPs) extremely difficult. A facile production of HEA-NPs inside carbon nanotubes and nanoparticles is demonstrated in this work. Electron microscopic and elemental analyses confirm encapsulated to be solution phase; some embrace carbides and form multidomains with chemical composition ranging from quaternary to quinary phase. Multidomains and nonmagnetic centers create hardening thus promoting coercivity significantly at room temperature. Alloying induces electron redistribution into high spin states, accounting for observed high saturation. Configurational entropy of encapsulated HEA-NPs lies on a range comparable with bulk.     

Heterostructured composite of NiFe-LDH nanosheets with Ti4O7 for oxygen evolution reaction

Developing oxygen evolution reaction (OER) electrocatalyst based on earth-abundant materials holds great promise for ascertaining water-splitting to surmount its deprived kinetics. In this regard, NiFe-LDH (layered double hydroxide) receives considerable attention owing to their layered structure. However, they still suffer from poor electronic conductivity and structural stability. We combined NiFe-LDH nanosheets with Magnéli phase Ti₄O₇ into a heterostructured composite. A series of analyses reveal that decorating Ti₄O₇ facilitates charge transfer to enhance the conductivity of NiFe-LDH-Ti₄O₇. During electrochemical measurement, Ni²⁺ is transformed to metastable Ni³⁺ (Ni (OH)→ NiOOH) before the OER onset potential. Thus, the presence of Ni³⁺ as the main active sites could improve the chemisorption of OH^? to facilitate OER. As a result, the NiFe-LDH-Ti₄O₇ catalyst delivers as low as onset potential (1.43 V). Combining the holey structure (NiFe-LDH and Ti₄O₇) and the defect engineering generated on NiFe-LDH-Ti₄O₇ as a synergistic effect improves the OER performance. The inclusion of Ti₄O₇ in the composite leads to more vacancy sites, as evidenced by the extended X-ray absorption fine structure (EXAFS) analysis. The obtained defective structure with a low coordination environment would improve the electronic conductivity and facilitate the adsorption process of H₂O onto metal cations, thereby increasing the intrinsic catalytic activity of NiOOH. The strong coupling of NiFe-LDH and Ti₄O₇ also increases the stability, and the heterostructured composite helps maintain the structural robustness of the LDH.     

Ferromagnetism study of Co<Subscript>0.2</Subscript>Mg<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Zn<Subscript>0.8−<Emphasis Type="Italic">x</Emphasis></Subscript>O films prepared by the sol–gel method

Co_0.2Mg _x Zn_0.8−x O films prepared with different molar ratio of magnesium acetate to zinc acetate were deposited on substrates by the sol–gel technique. X-ray diffraction, photoluminescence (PL) and ferromagnetism measurements were used to characterize the Co_0.2Mg _x Zn_0.8−x O diluted magnetic semiconductors. The acceptor-like defects were determined in the PL band and the intensity of the acceptor-related PL increased with increasing Mg concentration. Therefore, an increase in the number of the acceptor-like defects (zinc vacancies especially) in the Co_0.2Mg _x Zn_0.8−x O film may lead to the enhancement of the magnetic properties. It is worth noting that changes in Mg concentration and the number of the acceptor-like defects are important issues for producing strong ferromagnetism Co_0.2Mg _x Zn_0.8−x O films prepared by the sol–gel method.     

Dose verification of volumetric modulation arc therapy by using a NIPAM gel dosimeter combined with a parallel-beam optical computed tomography scanner

Volumetric modulated arc therapy (VMAT) was developed to shorten treatment time and increase target conformance. However, a true three-dimensional (3D) gel dosimeter is needed for dose verification. In this study, two clinic cases were adopted: a simple case of lung cancer and a complex case of larynx cancer. For each clinic case, two treatment plans were generated for the same planning target volume using VMAT and intensity modulated radiation therapy calculation software packages. An N-isopropylacrylamide (NIPAM) polymer gel dosimeter was used for 3D dose verification. In addition, the dose characteristics of the NIPAM gel dosimeter were investigated for the two clinic cases.

     

On the development of a triple‐preserving Maxwell's equations solver in non‐staggered grids

We present in this paper a finite difference solver for Maxwell's equations in non‐staggered grids. The scheme formulated in time domain theoretically preserves the properties of zero‐divergence, symplecticity, and dispersion relation. The mathematically inherent Hamiltonian can be also retained all the time. Moreover, both spatial and temporal terms are approximated to yield the equal fourth‐order spatial and temporal accuracies. Through the computational exercises, modified equation analysis and Fourier analysis, it can be clearly demonstrated that the proposed triple‐preserving solver is computationally accurate and efficient for use to predict the Maxwell's solutions. Copyright © 2009 John Wiley & Sons, Ltd.     

Impact of an indium oxide/indium-tin oxide mixed structure for GaN-based light-emitting diodes

An interesting GaN-based light emitting diode (LED) using a 50 nm indium oxide (In₂O₃)/250 nm indium-tin oxide (ITO) mixed structure to replace the commonly used ITO (250 nm) current spreading layer is fabricated and studied. Use of the In₂O₃ layer could reduce the contact resistance of p-GaN in LEDs. In addition, this highly-resistive In₂O₃ layer, below the ITO layer could improve the current spreading performance. Experimentally, at room temperature, using this mixed structure, the luminous and EL intensities are enhanced by 17.7 and 17.1%, respectively.     

The influence of lanthanum doping on the physical and electrical properties of BTV ferroelectric thin films

In this study, the ferroelectricity of as-deposited Bi_3.9La_0.1Ti_2.9V_0.1O₁₂ (BLTV), Bi_3.9Ti_2.9V_0.1O₁₂ (BTV), and Bi₄Ti₃O₁₂ (BIT) thin films was prepared and compared by rf magnetron sputtering technology. For the BLTV, BTV, and BIT thin films deposited on Pt/Ti/SiO₂/Si and SiO₂/Si substrate, the physical and electrical characteristics of lanthanum doped BTV (BLTV) were better than those of BIT and BTV thin films. Regarding the physical properties, the micro-structure of as-deposited BTV and BLTV thin films were obtained and compared by XRD patterns and SEM images. The BLTV and BTV thin films were also exhibited clear the ferroelectricity. The remanent polarization (P _r ) of as-deposited BLTV thin films was 11 μC/cm² as the measured frequency of 100 kHz. It was higher than those of BTV thin films. Finally, the polarization of BLTV thin film capacitor decreased by 9%, while that of the BTV decreased by 15% after the fatigue test with 10⁹ switching cycles.     

Environmental radiation detected at Lin Shin hospital in Taichung during the Fukushima nuclear power plant accident

This work is the first evaluation of environmental gamma exposure rates by the Nuclear Medicine Department at Lin Shin Hospital (LSH) in Taichung with Thermoluminescent dosimeter (TLD-100H) during the Fukushima Nuclear Power Plant (FNPP) accident. After the 9.0 M_W strong earthquake hit northern Japan on March 11, 2011, a TLD-100H was used to monitor environmental kerma rate at Taichung (2,500 km away from northern Japan) from Mar-08 to Apr-09, 2011 and evaluated kerma rate due to global fallout of the sever FNPP accidents. Exposure rates varied widely among positions close to the PET/CT facility. Observed kerma rates of up to 4.12 ± 0.62 mSv mo⁻¹ indicated an explicit, heavy leakage of photon through the PET/CT facility. No significant contributions were detected at Taichung, Taiwan. Hence, the health effect cause by the “extra radiation” from FNPP accidents is negligible. As this was a rare case of environmental monitoring during a nuclear power plant accident, its findings are of considerable significance.