Surface plasmon polaritons assisted diffraction in periodic subwavelength holes of metal films with reduced interplane coupling

Metal films grown on Si wafer perforated with a periodic array of subwavelength holes have been fabricated and anomalous enhanced transmission in the mid-infrared regime has been observed. High order transmission peaks up to Si(2,2) are clearly revealed due to the large dielectric constant contrast of the dielectrics at the opposite interfaces. Si(1,1) peak splits at oblique incidence both in TE and TM polarization, which confirms that anomalous enhanced transmission is a surface plasmon polaritons (SPPs) assisted diffraction phenomenon. Theoretical transmission spectra agree excellently with the experimental results and confirm the role of SPPs diffraction by the lattice.Comment: 4 pages, 5 figures, 26 reference

Spin-Charge Coupling in lightly doped Nd2−x_{2-x}Cex_{x}CuO4_4

We use neutron scattering to study the influence of a magnetic field on spin structures of Nd$_2$CuO$_4$. On cooling from room temperature, Nd$_2$CuO$_4$ goes through a series of antiferromagnetic (AF) phase transitions with different noncollinear spin structures. While a c-axis aligned magnetic field does not alter the basic zero-field noncollinear spin structures, a field parallel to the CuO$_2$ plane can transform the noncollinear structure to a collinear one ("spin-flop" transition), induce magnetic disorder along the c-axis, and cause hysteresis in the AF phase transitions. By comparing these results directly to the magnetoresistance (MR) measurements of Nd$_{1.975}$Ce$_{0.025}$CuO$_4$, which has essentially the same AF structures as Nd$_2$CuO$_4$, we find that a magnetic-field-induced spin-flop transition, AF phase hysteresis, and spin c-axis disorder all affect the transport properties of the material. Our results thus provide direct evidence for the existence of a strong spin-charge coupling in electron-doped copper oxides.Comment: 12 pages, 12 figure

Identifying adolescents' gaming preferences for a tobacco prevention social game: A qualitative study.

IntroductionConsidering the dangers of adolescent tobacco use, the successful design of behavioral programs is crucial for tobacco prevention. According to preliminary research, social game interventions can improve adolescent tobacco outcomes. The current qualitative study aims to (1) uncover the gaming elements that adolescents deem important for a positive learning experience, and (2) confirm these gaming elements with adolescents who are presented with a tobacco prevention game concept that applies these elements.MethodsFindings from this study are drawn from two phases. Phase 1 involved in-person focus group discussions (n = 15) and Phase 2 included three online focus groups and a paired interview with another set of adolescents (n = 15). The study was conducted under a project that aimed to design and test a social game-based tobacco prevention program for adolescents (Storm-Heroes). With open coding and thematic analysis, two research team members identified repeated topics and relevant quotes to organize them into themes. The themes evolved as new content was identified during the process. This process was repeated until thematic saturation was reached.ResultsThematic analysis across Phase 1 and Phase 2 revealed four major themes: 1) Balance during gaming challenges, 2) Healthy social interaction, 3) Performance and creative freedom, and 4) Fictional world and game mechanics for tobacco prevention.ConclusionThis study identified specific intervention features that best fit the needs of adolescents in the context of a social game for tobacco prevention. For future research, we will use a participatory approach to allow adolescents to take part in the design process, improve Storm-Heroes, and develop health promotional messages that can be incorporated into the program. Ultimately, a board game for tobacco prevention is expected to bring adolescents together to create lasting memories that nudge them away from tobacco use and the harm it can cause

Rapid discovery and crystallography study of highly potent and selective butylcholinesterase inhibitors based on oxime-containing libraries and conformational restriction strategies

22 p.-9 fig.-8 tab.Butyrylcholinesterase is regarded as a promising drug target in advanced Alzheimer’s disease. In order to identify highly selective and potent BuChE inhibitors, a 53-membered compound library was constructed via the oxime-based tethering approach based on microscale synthesis. Although A2Q17 and A3Q12 exhibited higher BuChE selectivity versus acetylcholinesterase, the inhibitory activities were unsatisfactory and A3Q12 did not inhibit Aβ1-42 peptide self-induced aggregation. With A2Q17 and A3Q12 as leads, a novel series of tacrine derivatives with nitrogen-containing heterocycles were designed based on conformation restriction strategy. The results demonstrated that 39 (IC50 = 3.49 nM) and 43 (IC50 = 7.44 nM) yielded much improved hBuChE inhibitory activity compared to the lead A3Q12 (IC50 = 63 nM). Besides, the selectivity indexes (SI = AChE IC50 / BChE IC50) of 39 (SI = 33) and 43 (SI = 20) were also higher than A3Q12 (SI = 14). The results of the kinetic study showed that 39 and 43 exhibited a mixed-type inhibition against eqBuChE with respective Ki values of 1.715 nM and 0.781 nM. And 39 and 43 could inhibit Aβ1-42 peptide self-induced aggregation into fibril. X-ray crystallography structures of 39 or 43 complexes with BuChE revealed the molecular basis for their high potency. Thus, 39 and 43 are deserve for further study to develop potential drug candidates for the treatment of Alzheimer’s disease.We gratefully acknowledge financial support from the Shandong Provincial Key Research and Development Project (No. 2019JZZY021011), Science Foundation for Outstanding Young Scholars of Shandong Province (ZR2020JQ31), Foreign Cultural and Educational Experts Project (GXL20200015001), Qilu Young Scholars Program of Shandong University, Distinguished Young and Middle-aged Scholar of Shandong University, the Taishan Scholar Program at Shandong Province, and MINECO (Grants SAF2016-76693-R to A.M), F.C., F.N. and X.B. were supported by the French Ministry of Armed Forces (Direction Générale de l'Armement and Service de Santé des Armées, NBC-5-C-4210). Authors would like to thank the ESRF for long-term beamtime access (MX2329 IBS BAG).Peer reviewe

Superconductivity of the Ba–Y–Cu–O System in the Liquid Nitrogen Temperature

The oxide compounds of BaxY1-xCuO3-y (x=0.3–0.5) have been successfully prepared. The zero resistance temperature of the samples is at 91.5K, with Tc onsets higher than 100K. ac magnetic susceptibility measurements show that the superconducting phase at 82K is not less than 85% in volume. </jats:p

High T_c Superconductivity of Sr–La–Cu–O and Ba–Y–Cu–O Thin Films

High Tc Sr–La–Cu–O and Ba–Y–Cu–O thin films have been successfully prepared by the magnetron sputtering method. The Tc onsets for Sr–La–Cu–O are 25–30K and Δ Tc are 7.5–8.5K. The slope near Tc is 3.05T/K. The Tc onsets of Ba–Y–Cu–O thin films are 87–89.5K and the zero resistance is at 20K. The samples are diamagnetic and the Meissner effect appeared around 10K. </jats:p