薄膜无源技术和无源微电路抬头射频技术掀起革命风暴

无线电技术的不断推陈出新已成为微电子技术领域发展的强大动力,无论是在客户应用中还是关键业务应用中,都要求解决方案的体型更小、功能更强、可靠性更高、信号清晰度更好,并且始终保持更低的能耗.这无疑对新技术提出了更高的要求,而射频电路的设计无疑是所有设计中极为关键的设计之一,本文通过介绍下一代薄膜无源技术和无源微电路来揭示如何迎接射频技术挑战.     

New Interfaces and Approaches to Machine Learning When Classifying Gestures within Music

Interactive music uses wearable sensors (i.e., gestural interfaces—GIs) and biometric datasets to reinvent traditional human–computer interaction and enhance music composition. In recent years, machine learning (ML) has been important for the artform. This is because ML helps process complex biometric datasets from GIs when predicting musical actions (termed performance gestures). ML allows musicians to create novel interactions with digital media. Wekinator is a popular ML software amongst artists, allowing users to train models through demonstration. It is built on the Waikato Environment for Knowledge Analysis (WEKA) framework, which is used to build supervised predictive models. Previous research has used biometric data from GIs to train specific ML models. However, previous research does not inform optimum ML model choice, within music, or compare model performance. Wekinator offers several ML models. Thus, we used Wekinator and the Myo armband GI and study three performance gestures for piano practice to solve this problem. Using these, we trained all models in Wekinator and investigated their accuracy, how gesture representation affects model accuracy and if optimisation can arise. Results show that neural networks are the strongest continuous classifiers, mapping behaviour differs amongst continuous models, optimisation can occur and gesture representation disparately affects model mapping behaviour; impacting music practice.     

砷的代谢机制、毒性和生物监测

砷化合物是备受关注的一类污染物,特别是饮用水中的砷污染引发了全球性的健康问题.本文综述了近年来人们对砷的代谢机制、毒性和生物监测的研究进展.砷在生物体内的代谢过程十分复杂,在氧化还原酶和甲基转移酶的参与下,产生一系列的代谢产物和中间产物.其中,砷的原始摄入形态、代谢产物及中间产物由于不同的物理化学性质,体现了不同的毒性.人类和不同的动物由于不同的砷代谢机理和甲基化能力,也表现了对砷毒性抵抗能力的差异.在生物体内,一些砷化合物与生物蛋白相互作用,影响它们的存在形式、分布和传输,是砷的生物代谢和毒理研究中不可或缺的内容.生物监测是一种直接有效的污染物健康风险评估方法.在尿液、血液、唾液、头发和指甲中砷化合物直接反映了暴露主体的砷暴露程度,这5种生物介质作为砷暴露的生物标志物各有优缺点.在砷的研究中,代谢机制和毒性的研究可以帮助选择合适的生物监测方法,做出合理准确的健康风险评估.生物监测也可促进对砷的代谢机制和毒性的理解,推断可能的代谢途径,定量毒性剂量效应,两者相互依赖相互促进.     

Impact of Collection Volume and DNA Extraction Method on the Detection of Biomarkers and HPV DNA in First-Void Urine

The potential of first-void (FV) urine as a non-invasive liquid biopsy for detection of human papillomavirus (HPV) DNA and other biomarkers has been increasingly recognized over the past decade. In this study, we investigated whether the volume of this initial urine stream has an impact on the analytical performance of biomarkers. In parallel, we evaluated different DNA extraction protocols and introduced an internal control in the urine preservative. Twenty-five women, diagnosed with high-risk HPV, provided three home-collected FV urine samples using three FV urine collection devices (Colli-Pee) with collector tubes that differ in volume (4, 10, 20 mL). Each collector tube was prefilled with Urine Conservation Medium spiked with phocine herpesvirus 1 (PhHV-1) DNA as internal control. Five different DNA extraction protocols were compared, followed by PCR for GAPDH and PhHV-1 (qPCR), HPV DNA, and HBB (HPV-Risk Assay), and ACTB (methylation-specific qPCR). Results showed limited effects of collection volume on human and HPV DNA endpoints. In contrast, significant variations in yield for human endpoints were observed for different DNA extraction methods (p < 0.05). Additionally, the potential of PhHV-1 as internal control to monitor FV urine collection, storage, and processing was demonstrated.     

Solvent-Free Synthesis of Core-Functionalised Naphthalene Diimides by Using a Vibratory Ball Mill: Suzuki,Sonogashira and Buchwald–Hartwig Reactions

Solvent-free synthesis by using a vibratory ball mill (VBM) offers the chance to access new chemical reactivity, whilst reducing solvent waste and minimising reaction times. Herein, we report the core functionalisation of N,N’-bis(2-ethylhexyl)-2,6-dibromo-1,4,5,8-naphthalenetetracarboxylic acid (Br₂-NDI) by using Suzuki, Sonogashira and Buchwald–Hartwig coupling reactions. The products of these reactions are important building blocks in many areas of organic electronics including organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) and organic photovoltaic cells (OPVCs). The reactions proceed in as little as 1 h, use commercially available palladium sources (frequently Pd(OAc)₂) and are tolerant to air and atmospheric moisture. Furthermore, the real-world potential of this green VBM protocol is demonstrated by the double Suzuki coupling of a monobromo(NDI) residue to a bis(thiophene) pinacol ester. The resulting dimeric NDI species has been demonstrated to behave as an electron acceptor in functioning OPVCs.     

Evidence for thermal decomposition contributions to the mass spectra of chlorinated phenoxyacid herbicides obtained by particle beam liquid chromatography mass spectrometry

The spectral quality of a group of chlorinated phenoxyacid herbicides has been shown to degrade under certain conditions upon introduction into the mass spectrometer by a particle beam interface. Experiments were performed to investigate these changes in spectra. Normalized ion chromatograms were generated for the herbicides, and the results showed a broadening of the profiles of some ions, indicating a longer residence time in the ion source. These ions were postulated as coming from the ionization of thermal degradation products from the herbicides. The generation of these ions was dependent on ion source temperature, analyte concentration, and, by implication, ion source cleanliness. Tandem mass spectrometry experiments were performed on these ions from the herbicides and ions from the corresonding phenols. The tandem mass spectra of the ions from the herbicides were similar to the tandem mass spectra of the ions from the phenols. Therefore, it appears that the particle beam mass spectra of the chlorinated phenoxyacid herbicides are composite spectra with contributions from the gas phase ionization of the parent herbidides and thermal decomposition products.     

How useful are closed captions for learning mathematics via online video?

Closed captioning of instructional videos is a topic that has not seen much discussion despite its importance for hearing-impaired students and recent legal ramifications if videos are not appropriately captioned. In particular, it is unclear what best practice in captioning videos should be to benefit all learners in disciplines such as mathematics with a reliance on the development of visual explanation while providing audio narration. In this paper, we report on a study undertaken at an Australian university, to investigate the perceived level of usefulness of captions and their automatic translations in a mathematics course. We discovered that students broadly agreed that captions are a useful learning feature: to allow flexibility of where and when a video is watched, but also to help understand speaker accents, and clarify explanations that are difficult to hear in the recording. Due to the high levels of use and perceived educational benefits of closed captions in online video but limited literature, there is a significant need for new research in this area. An urgent discussion is needed to explore how students engage with closed captions, how they may support learning, and to investigate implications on instructional design of mathematical videos.     

Utilizing Lifetimes to Suppress Random Coil Features in 2D IR Spectra of Peptides

We report that the waiting time delay in 2D IR pulse sequences can be used to suppress signals from structurally disordered regions of amyloid fibrils. At a waiting time delay of 1.0 ps, the random coil vibrational modes of amylin fibrils are no longer detectable, leaving only the sharp excitonic vibrational features of the fibril β-sheets. Isotope labeling with (13)C(18)O reveals that structurally disordered residues decay faster than residues protected from solvent. Since structural disorder is usually accompanied by hydration, we conclude that the shorter lifetimes of random-coil residues is due to solvent exposure. These results indicate that 2D IR pulse sequences can utilize the waiting time to better resolve solvent-protected regions of peptides and that local mode lifetimes should be included in simulations of 2D IR spectra.