Theoretical Investigating Mechanisms of Drug-Resistance Generated by Mutation-Induced Changes in Influenza Viruses

Influenza A (A/H\begin{document}$ x $\end{document}N\begin{document}$ y $\end{document}) is a significant public health concern due to its high infectiousness and mortality. Neuraminidase, which interacts with sialic acid (SIA) in host cells, has become an essential target since its highly conserved catalytic center structure, while resistance mutations have already generated. Here, a detailed investigation of the drug resistance mechanism caused by mutations was performed for subtype N9 (A/H7N9). Molecular dynamics simulation and alanine-scanning-interaction-entropy method (ASIE) were used to explore the critical differences between N9 and Zanamivir (ZMR) before and after R294K mutation. The results showed that the mutation caused the hydrogen bond between Arg294 and ZMR to break, then the hydrogen bonding network was disrupted, leading to weakened binding ability and resistance. While in wild type (A/H7N9\begin{document}$ ^{ \rm{WT}} $\end{document}), this hydrogen bond was initially stable. Meanwhile, N9 derived from A/H11N9 was obtained as an R292K mutation. Then the relative binding free energy of N9 with five inhibitors (SIA, DAN, ZMR, G28, and G39) was predicted, basically consistent with experimental values, indicating that the calculated results were reliable by ASIE. In addition, Arg292 and Tyr406 were hot spots in the A/H11N9\begin{document}$ ^{ \rm{WT}} $\end{document}-drugs. However, Lys292 was not observed as a favorable contributing residue in A/H11N9\begin{document}$ ^{ \rm{R292K}} $\end{document}, which may promote resistance. In comparison, Tyr406 remained the hotspot feature when SIA, ZMR, and G28 binding to A/H11N9\begin{document}$ ^{ \rm{R292K}} $\end{document}. Combining the two groups, we speculate that the resistance was mainly caused by the disruption of the hydrogen bonding network and the transformation of hotspots. This study could guide novel drug delivery of drug-resistant mutations in the treatment of A/H\begin{document}$ x $\end{document}N9.     

基于单片机的远程监测控制装置设计

基于广泛使用的PSTN网络,综合使用线路信号检测芯片判断线路状态、DTMF收发芯片接收发送DTMF信号进行命令交互,采用单片机集中控制,制作的远程监控装置,具有广泛的应用价值.     

气相色谱与串联质谱联用检测血清中脱氢表雄酮

在晚期前列腺癌雄激素全阻断治疗最终导致前列腺癌雄激素非依赖性的转变过程中,肾上腺分泌脱氢表雄酮(DHEA)被认为是重要的诱因。本研究主要利用睾丸摘除(去势)大鼠模型,对血清中DHEA浓度进行测定。采用了气相色谱与串联质谱联用(GC-MS/MS)技术,建立了高灵敏度的测定大鼠血清中脱氢表雄酮(DHEA)的方法。样品经过甲醇沉蛋白,而后固相萃取提取血清中微量的DHEA,通过七氟丁酸酐(HF-BA)衍生,采用GC-MS/MS测定。对固相萃取条件、衍生化条件以及质谱测定条件进行优化。DHEA在0.1~100μg/L范围内线性良好,相关系数r为0.9996;在2~50μg/L浓度范围内,加标回收率在99%~106%之间;相对标准偏差小于5%。本方法灵敏度高,选择性好,可满足临床对于血清样品中DHEA的测定要求。对去势大鼠血清中DHEA测定结果表明,去势后DHEA明显上升。     

一种用于电子纸的电泳液的显示性能研究

用有机颜料汉沙黄(P.Y.3)、苏丹黑和合适的稳定剂为原料配制了一种性能稳定的电泳显示液.分析了此电泳显示液中颜料微粒的带电机理及其影响因素,研究了在改变电压方向时反射光谱与吸收光谱的变化及其原因,光谱分析结果表明体系中存在的各种吸附使显示效果受到局限,反射谱与吸收谱的变化在表征器件的显示特性时呈现出一致性,器件的反射光强和反射率在不同波长上有区域选择性,同时对比度也有区域选择性,这决定了在监测器件的响应时应选择的波长范围以及可利用的光源.兼顾灵敏性和测试信号强度的需求,选用峰值波长为470 nm的蓝光二极管为光源,电泳槽的厚度为0.2 mm,用荧光光谱仪监测相同周期不同幅值脉冲电压作用下颜料微粒在493 nm波长处的反射光强的变化,并由示波器记录并输出反射光强随驱动电压的变化,还结合相关理论讨论了驱动电压对器件的反射光强和对比度的影响.     

使用溅射AlN成核层实现大规模生产深紫外LED

高质量AlN薄膜对制造高性能深紫外器件非常重要,但是目前还很难使用大型工业MOCVD生长出高质量的AlN薄膜.采用磁控溅射制备了不同厚度的用作成核层的AlN薄膜,使用大型工业MOCVD直接在成核层上高温生长AlN外延层,研究了不同成核层对AlN外延层质量的影响.通过扫描电子显微镜和原子力显微镜对成核层AlN薄膜的表面形貌进行表征;使用高分辨X射线衍射仪对AlN外延层晶体质量进行表征,结果表明:在溅射成核层上生长的AlN外延层的晶体质量有显著提高.使用大型工业MOCVD在蓝宝石衬底上成功制备出中心波长为282 nm的可商用深紫外LED,在注入电流为20 mA时,单颗深紫外LED芯片的光输出功率达到了1.65 mW,对应的外量子效率为1.87%,饱和光输出功率达到4.31 mW.     

弹道目标平动补偿与微多普勒特征提取方法

针对传统逆合成孔径雷达(ISAR)成像中的平动补偿方法并不适用于弹道目标平动补偿的问题,该文提出了一种弹道目标平动补偿与微多普勒(m-D)特征提取方法。在分析有翼弹道目标未完成平动补偿时的m-D效应的基础上,首先采用形态学中的骨架提取方法抑制1维距离像旁瓣,再在快时间频率(距离)-慢时间平面上搜索分离各散射点的m-D特征曲线,然后对其进行经验模式分解(EMD)分解,利用分解结果中的趋势项分量完成目标回波的平动补偿,并通过分析EMD分解结果获得了目标的自旋频率、锥旋频率等特征信息。仿真实验验证了所提方法的有效性与鲁棒性。     

Inverse Filter of Chaos with Applications on Parameter Estimation

Linear filter may hide simple nonlinearity of chaotic dynamics, which would decrease the accuracy of parameter estimation, and reduce the effect of signal processing. Based on theoretical and experimental analysis, this paper provides a method to recover the dynamics. An example of radar data proves that the dynamics hidden in observed data can be found by inverse filter of chaos. It is also pointed out that inverse filter of chaos can be applied to mine inner regulation of some time series and estimate parameters of nonlinear models in data processing for radar. And the method is significant to clutter modeling.     

MBE生长高电阻率GaAs基InAlAs组分渐变缓冲层

研究了用分子束外延(MBE)方法,在SI-GaAs衬底上不同低温生长的台阶式组分渐变InAlAs缓冲层结构.用原子力显微镜(AFM)观测表面形貌,生长温度为340℃时,外延层表面粗糙度为1.79nm.用Van der Pauw方法研究了材料的电学特性,室温电阻率ρ:2.6× 10Ω·cm.(电学性能测试表明200V电压间距1mm时,漏电流仅为0.3μA).高分辨X射线测试样品显示为良好的层状结构,晶体质量随生长逐渐变好.首次用变温Hall测试研究多层InAlAs缓冲层材料内部的载流子传输机制,并用热激电流谱(TSC)分析了其高阻机制.     

Hierarchical Nanowire Arrays Based on ZnO Core−Layered Double Hydroxide Shell for Largely Enhanced Photoelectrochemical Water Splitting

Well‐aligned hierarchical nanoarrays containing ZnO core and layered double hydroxide (LDH) nanoplatelets shell have been synthesized via a facile electrosynthesis method. The resulting ZnO@CoNi–LDH core?shell nanoarray exhibits promising behavior in photoelectrochemical water splitting, giving rise to a largely enhanced photocurrent density as well as stability; much superior to those of ZnO‐based photoelectrodes. This is attributed to the successful integration of photogenerated electron–hole separation originating from the ZnO core and the excellent electrocatalytic activity of LDH shell. This work provides a facile and cost‐effective strategy for the fabrication of multifunctional nanoarrays with a hierarchical structure, which can be potentially used in energy storage and conversion devices.