ALBERT

Description: Casein kinase 1α (CK1α), a component of the β-catenin destruction complex, is a critical regulator of Wnt signaling; its ablation induces both Wnt and p53 activation. To characterize the role of CK1α (encoded byCsnk1a1) in skin physiology, we crossed mice harboring floxedCsnk1a1with mice expressing K14–Cre–ERT2to generate mice in which tamoxifen induces the deletion ofCsnk1a1exclusively in keratinocytes [single-knockout (SKO) mice]. As expected, CK1α loss was accompanied by β-catenin and p53 stabilization, with the preferential induction of p53 target genes, but phenotypically most striking was hyperpigmentation of the skin, importantly without tumorigenesis, for at least 9 mo afterCsnk1a1ablation. The number of epidermal melanocytes and eumelanin levels were dramatically increased in SKO mice. To clarify the putative role of p53 in epidermal hyperpigmentation, we established K14–Cre–ERT2CK1α/p53 double-knockout (DKO) mice and found that coablation failed to induce epidermal hyperpigmentation, demonstrating that it was p53-dependent. Transcriptome analysis of the epidermis revealed p53-dependent up-regulation of Kit ligand (KitL). SKO mice treated with ACK2 (a Kit-neutralizing antibody) or imatinib (a Kit inhibitor) abrogated the CK1α ablation-induced hyperpigmentation, demonstrating that it requires the KitL/Kit pathway. Pro-opiomelanocortin (POMC), a precursor of α-melanocyte–stimulating hormone (α-MSH), was not activated in the CK1α ablation-induced hyperpigmentation, which is in contrast to the mechanism of p53-dependent UV tanning. Nevertheless, acute sunburn effects were successfully prevented in the hyperpigmented skin of SKO mice. CK1α inhibition induces skin-protective eumelanin but no carcinogenic pheomelanin and may therefore constitute an effective strategy for safely increasing eumelanin via UV-independent pathways, protecting against acute sunburn.

Description: Glucuronidation mediated by uridine 5′-diphospho (UDP)-glucuronosyltransferase is an important detoxification pathway. However, identifying a selective probe of UDP- glucuronosyltransferase is complicated because of the significant overlapping substrate specificity displayed by the enzyme. In this paper, desacetylcinobufagin (DACB) 3-O- and 16-O-glucuronidation were found to be isoform-specific probe reactions for UGT1A4 and UGT1A3, respectively. DACB was well characterized as a probe for simultaneously determining the catalytic activities of O-glucuronidation mediated by UGT1A3 and UGT1A4 from various enzyme sources, through a sensitive analysis method. Scientific Reports 5 doi: 10.1038/srep09627

Description: Abstract We demonstrate that self‐propagating sintering reaction could be activated and dramatically enhanced by laser excitation of ion dopants in the solid‐state reactants. Near‐resonant laser absorption and subsequent nonradiative decays make the solid‐state reactants be sintered efficiently while ionic excitations catalyze self‐propagating solid‐state reactions. As a prototype demo, we synthesized white light upconversion phosphors NaYbF4:Pr3+/Gd3+. A continuous‐wave laser at 980 nm was used to populate Yb3+ ions in YbF3 to excited level, which react with NaF to preform NaYbF4 nuclei. The preformed nuclei enhanced laser excitation and energy transfer to those ions that could not be directly excited by the pump laser and thus enabled self‐propagating solid‐state sintering synthesis of NaYbF4 microcrystals at quite low laser powers. Laser excitation of Yb3+ ions could also benefit facile rare‐earth ion doping through activated self‐propagating reactions. Gd3+ and Pr3+ ions were doped in NaYbF4 by simply adding Gd3+ and Pr3+ ionic oxides or fluorides in the raw materials. In addition, Gd3+ ions doping in F− anions ambient could transform the NaYbF4 microcrystal phase from cubic to hexagonal and tune upconversion photoluminescence. This synthetic method can be widely applied to synthesize many other solid‐state compounds, perovskite solar cells, photocatalysts, solid oxide fuel cells, and so forth.

Description: Author(s): Abduweli Ablimit, Yun-Lei Sun, Hao Jiang, Si-Qi Wu, Ya-Bin Liu, and Guang-Han Cao We report the synthesis, crystal structure, physical properties, and first-principles calculations of a vanadium-based oxytelluride Rb 1 − δ V 2 Te 2 O ( δ ≈ 0.2 ). The crystal structure bears two-dimensional V 2 O square nets sandwiched with tellurium layers, mimicking the structural motifs of cuprate and iron-b... [Phys. Rev. B 97, 214517] Published Wed Jun 20, 2018

Description: Sensors, Vol. 18, Pages 1154: Coherent and Noncoherent Joint Processing of Sonar for Detection of Small Targets in Shallow Water Sensors doi: 10.3390/s18041154 Authors: Xiang Pan Jingning Jiang Si Li Zhenping Ding Chen Pan Xianyi Gong A coherent-noncoherent joint processing framework is proposed for active sonar to combine diversity gain and beamforming gain for detection of a small target in shallow water environments. Sonar utilizes widely-spaced arrays to sense environments and illuminate a target of interest from multiple angles. Meanwhile, it exploits spatial diversity for time-reversal focusing to suppress reverberation, mainly strong bottom reverberation. For enhancement of robustness of time-reversal focusing, an adaptive iterative strategy is utilized in the processing framework. A probing signal is firstly transmitted and echoes of a likely target are utilized as steering vectors for the second transmission. With spatial diversity, target bearing and range are estimated using a broadband signal model. Numerical simulations show that the novel sonar outperforms the traditional phased-array sonar due to benefits of spatial diversity. The effectiveness of the proposed framework has been validated by localization of a small target in at-lake experiments.

Description: The Journal of Organic Chemistry DOI: 10.1021/acs.joc.6b01720

Description: Optimization techniques have been applied to structural health monitoring and damage detection of civil infrastructures for two decades. The standard particle swarm optimization (PSO) is easy to fall into the local optimum and such deficiency also exists in the multiparticle swarm coevolution optimization (MPSCO). This paper presents an improved MPSCO algorithm (IMPSCO) firstly and then integrates it with Newmark’s algorithm to localize and quantify the structural damage by using the damage threshold proposed. To validate the proposed method, a numerical simulation and an experimental study of a seven-story steel frame were employed finally, and a comparison was made between the proposed method and the genetic algorithm (GA). The results show threefold: (1) the proposed method not only is capable of localization and quantification of damage, but also has good noise-tolerance; (2) the damage location can be accurately detected using the damage threshold proposed in this paper; and (3) compared with the GA, the IMPSCO algorithm is more efficient and accurate for damage detection problems in general. This implies that the proposed method is applicable and effective in the community of damage detection and structural health monitoring.

Description: In this research, the novel concept of a resonance-based reflector (RBR) was proposed, and a ring-shaped RBR was utilized to design a unidirectional antenna with low-profile and broadband characteristics. Research found the ring operates as two half-wavelength (λ/2) resonators. Then, the resonance effect transforms the reflection phase of the ring RBR, and achieves a reflection phase of 0° 〈 ϕ 〈 180° in a wide frequency range above the resonance. Then, the in-phase reflection characteristic (−90° 〈 ϕ 〈 90°) can be obtained in the wide frequency band by placing an antenna above the RBR with a distance smaller than λ/4. Two unidirectional antennas, named Case 1 and Case 2, were designed with the ring-shaped RBRs and bowtie antennas (RBR-BAs). The impedance bandwidths of Case 1 and the Case 2 are 2.04–5.12 GHz (86.3%) and 1.97–5.01 GHz (87.1%), respectively. The front-to-back ratio (FBR, an important parameter to measure the unidirectional radiation) of Case 1 ranges from 5–9.9 dB for frequencies 2.04–2.42 GHz, and the FBR of Case 2 ranges from 5–16 dB for frequencies 2.16–3.15 GHz. The proposed concept of RBR is desirable in wideband unidirectional antenna design, and the designing antennas can be used at the front end of wireless systems—such as indoors communication, remote sensing, and wireless sensor systems—for signal receiving or transmitting.

Description: We present a dip-coatable, high-capacitance ion gel dielectric for scalable fabrication of three-dimensional (3D) electrowetting-on-dielectric (EWOD) devices such as an n × n liquid prism array. Due to the formation of a nanometer-thick electric double layer (EDL) capacitor, an ion gel dielectric offers two to three orders higher specific capacitance (c ≈ 10 μF/cm2) than that of conventional dielectrics such as SiO2. However, the previous spin-coating method used for gel layer deposition poses several issues for 3D EWOD device fabrication, particularly when assembling multiple modules. Not only does the spin-coating process require multiple repetitions per module, but the ion gel layer also comes in risks of damage or contamination due to handling errors caused during assembly. In addition, it was observed that the chemical formulation previously used for the spin-coating method causes the surface defects on the dip-coated gel layers and thus leads to poor EWOD performance. In this paper, we alternatively propose a dip-coating method with modified gel solutions to obtain defect-free, functional ion gel layers without the issues arising from the spin-coating method for 3D device fabrication. A dip-coating approach offers a single-step coating solution with the benefits of simplicity, scalability, and high throughput for deposition of high-capacitance gel layers on non-planar EWOD devices. An ion gel solution was prepared by combining the [EMIM][TFSI] ionic liquid and the [P(VDF-HFP)] copolymer at various wt % ratios in acetone solvent. Experimental studies were conducted to fully understand the effects of chemical composition ratios in the gel solution and how varying thicknesses of ion gel and Teflon layers affects EWOD performance. The effectiveness and potentiality of dip-coatable gel layers for 3D EWOD devices have been demonstrated through fabricating 5 × 1 arrayed liquid prisms using a single-step dip-coating method. Each prism module has been individually controlled to achieve spatial beam steering without the need for bulky mechanical moving parts.