This article reports an ultra-low-power (ULP) Bluetooth low-energy (BLE) receiver with an improved spurious-free dynamic range (SFDR). It features two passive-intensive RF techniques: an N -path passive balun-LNA and a pipeline down-mixing baseband (BB)-extraction scheme. They together offer a high- Q bandpass response at RF, and a high passive gain to suppress the noise of the BB hybrid complex filter. Specifically, the balun-LNA is a step-up triple-coil transformer aided by an N -path switched-capacitor (SC) network to perform in-band voltage amplification, high- Q bandpass filtering, I/Q down-mixing, and input-impedance matching. Instead of using active amplifiers as the first-BB gain stage, we passively extract the four-phase ( I/Q and differential) BB signals using a pipeline of passive-SC networks that can stack up the voltage gain. Prototyped in TSMC 28-nm CMOS, the BLE receiver consumes only 266 μW , of which 75 μW in the BB hybrid filter at 1 V, and 191 μW in the LO divider + buffer at 0.6 V. Measured at the maximum RF-to-BB gain of 61 dB, the receiver exhibits a noise figure (NF) of 6.1 dB and an out-of-band (OOB)-IIP3 of 22.5 dBm. The corresponding SFDR is 77 dB for a 1-MHz BLE channel and a 10-dB minimum signal-to-noise ratio (SNR min ). The OOB-B−1 dB is −3 dBm.
A reduced removal of dysfunctional mitochondria is common to aging and age-related neurodegenerative pathologies such as Alzheimer’s disease (AD). Strategies for treating such impaired mitophagy would benefit from the identification of mitophagy modulators. Here we report the combined use of unsupervised machine learning (involving vector representations of molecular structures, pharmacophore fingerprinting and conformer fingerprinting) and a cross-species approach for the screening and experimental validation of new mitophagy-inducing compounds. From a library of naturally occurring compounds, the workflow allowed us to identify 18 small molecules, and among them two potent mitophagy inducers (Kaempferol and Rhapontigenin). In nematode and rodent models of AD, we show that both mitophagy inducers increased the survival and functionality of glutamatergic and cholinergic neurons, abrogated amyloid-β and tau pathologies, and improved the animals’ memory. Our findings suggest the existence of a conserved mechanism of memory loss across the AD models, this mechanism being mediated by defective mitophagy. The computational–experimental screening and validation workflow might help uncover potent mitophagy modulators that stimulate neuronal health and brain homeostasis.
We provide evidence of delayed attention and inaction in response to COVID-19 in countries that did not experience SARS in 2003. Using cross-country data, we find that individuals in countries that had SARS infections in 2003 searched more intensively for COVID-19-related information on Google in late January 2020, the time of the first known outbreak in Wuhan, China. Early attention to the novel virus, as measured by Google searches, is associated with deeper stock market drops in countries with SARS experience. In contrast, people in countries without SARS experience started to pay more attention much later, in March. Moreover, governments in these countries responded significantly more slowly in implementing social distancing policies to combat domestic COVID-19 outbreaks than governments in countries with SARS experience. Moreover, such early responses of individuals and governments in countries with SARS experience are prevalent within continent, even in non-Asian countries. Furthermore, people in countries with SARS experience are more compliant with social distancing rules. These timely attention and proactive responses of individuals and governments are more pronounced in countries that reported deaths caused by SARS, which left deeper imprints. Our findings suggest that the imprint of similar viruses’ experience is a fundamental mechanism underlying timely responses to COVID-19.
Mixed-dimensional 2D/3D halide perovskite solar cells promise high stability but practically deliver poor power conversion efficiency, and the 2D perovskite component has been held as the culprit because its intrinsic downsides (ill charge conductivity, wider bandgap, and strong exciton binding) were intuitively deemed to hinder carrier transport. In this publication, Prof. Xing’s team shows that the 2D perovskite fragments, in fact, allow free migration of carriers in darkness but only block the carrier transport under illumination. While surely limiting the photovoltaic performance, such photoinduced carrier blocking effect is unexplainable by the traditional understanding above but is found to stem from the trap-filling-enhanced built-in potential of the 2D/3D perovskite interface. By parsing the depth-profile nanoscopic phase arrangement of the mixed-dimensional 2D/3D perovskite film for solar cells and revealing a photoinduced potential barrier up to several hundred meV, Prof. Xing’s team further elucidates how the photoinduced carrier blocking mechanism jeopardizes the short-circuit current and fill factor.
Prof. Xiaoling XU’s research team studied the mechanism of breast cancer metastasis suppressor gene ATP11b-mediated metastasis and related therapeutic drugs, which can improve the treatment effect of patients with breast cancer metastasis. The research team used genome-wide knockout library technology to complete the screening of driver genes and found that ATP11b is a suppressor of cancer metastasis. Deleting ATP11b at the genome level not only significantly increases the metastatic ability of BRCA1-mutant breast cancer cells, but also induces displacement of non-apoptotic phosphatidylserine on the cell membrane, thereby promoting the formation and pre-metastatic niche. Through public database research and validation in cell and animal models, the research team determined that paclitaxel and docetaxel can effectively block tumor metastasis associated with the loss function of ATP11b.
An Electronic Insect with Super Agility and Precise Trajectory Control: Super agility and precise trajectory control are two desirable features for all moving objects, but they become very challenging for small soft robots without rigid structures to support rapid manipulations. In this work, a curved piezoelectric thin film driven at its structural resonant frequency is utilized as the main body of an electronic insect for its fast translational movements, and two electrostatic foot-pads are employed for its swift rotational motions. A highest relative centripetal acceleration of 28 body-length/s2 among all artificial robots is realized on a 65 mg-tethered prototype, which is better than those of common insects, including the cockroach. The trajectory manipulation demonstration is accomplished by navigating the electronic insect to pass through a 120 cm-long track in a maze within 5.6 seconds. One potential application is presented by carrying a 180 mg on-board sensor to record a gas concentration route map and to identify the location of the leakage source. Moreover, we construct a 240 mg-untethered electronic insect to enhance the practicality. Equipped with a payload of 1660 mg to include the control circuit, a battery, and photoresistors, the untethered prototype can follow a designated, 27.9 cm-long “S” shape path in 36.9 seconds.
Although the role of morphology in alphabetic language processing has been extensively studied, it is still unclear how morphology is enabled and constrained in morpho-syllabic languages like Chinese. This study aims to inspect the time courses and patterns of brain activation associated with Chinese morphological constraint encoding. Chinese native speakers were recruited to perform visual lexical decisions on real Chinese compound words, pseudowords, and nonwords, whilst behavioral, electroencephalographic, and functional near infrared spectroscopy data were simultaneously recorded. For the first time, both morphological and semantic effects were examined to reveal the corresponding spatio-temporal brain activation patterns based on multimodal data. Brain activation differences between pseudowords and real words indexed morphological sensitivity, whereas differences between real words or pseudowords and nonwords characterized semantic effects. Electrophysiological data showed that semantic processing occurred earlier (N400, 300–450 msec) than morphological processing (450–570 msec), while brain activation patterns revealed a differentiation between morphological parsing (specified in the left inferior frontal gyrus) and semantic analysis (in a broader fronto-temporal network). These findings offer new evidence that morphological constraints are encoded at a late stage of compound word processing in Chinese and suggest that the left prefrontal cortex plays an essential role in this process.
Challenging the assumptions of the principal-agent theory, the recent bureaucratic politics literature contends that politicians do not necessarily have weaker capacities and bureaucrats are not necessarily bad apples. What this means for the delegation decision remains underexplored, particularly regarding how legislative capacity and bureaucratic reputation jointly affect delegation. We examine this issue with a trust perspective and a survey experiment of city mayors. Treating bureaucratic reputation as individual trustworthiness and perceived legislative capacity as institutional trustworthiness, we find they interact in complex ways in influencing delegation. When bureaucratic reputation is high, perceived legislative capacity is not associated with delegation. Perceived legislative capacity matters only when bureaucratic reputation is low, and high capacity relates to greater delegation willingness than when capacity is not considered. The findings have implications for studies on delegation, discretion, and bureaucratic reputation.
This is a book about “books,” which is a collection on review articles of books. It shows the historian Wang Di’s historical thinking of reading in the past forty years. It could also be considered as his reading history. From this book, we can see his understanding of history and reality of the society we live. To discover the “small voice of history” is to listen to the real voice of the people.
Researchers often assume a strong, linear relationship between regular- and reverse-keyed items, with responses on regular-keyed items (e.g., agree) perfectly mirroring those on reverse-keyed items (e.g., disagree). The current research challenges this received view and propounds a possible nonlinear relationship, partly due to the logical tendency of midlevel respondents to disagree with both types of items. In four examples, a nonlinear model consistently explained additional item variance beyond a linear model. We further demonstrate that this relationship is moderated by item characteristics such as item extremity (job satisfaction) and item softening (self-esteem). Suboptimal modeling of the relationship may result in the apparent bidmensionality of a construct that characterizes regular- and reverse-keyed items as separate factors. User-friendly syntax for the examination of nonlinearity is provided to enhance the accessibility of the procedure.
The decision of the Court of First Instance of Hong Kong High Court in November 2019 which strikes down the anti-mask law made by the Hong Kong Government has been controversial. It concerns the question of whether it is constitutional for a government to restrict individuals from wearing masks or force individuals to wear masks in public in different situations or scenarios. What is the legal nature of mask wearing and other conducts of face covering? Can face covering be considered as an expressive conduct protected the same way as freedom of speech? This article argues that if face covering, such as wearing masks, can be considered as an expressive conduct protected under the freedom of speech, and thus the government’s legislation, for public safety reasons, restricting individuals from wearing masks or other forms of face covering in public are held unconstitutional, similar analogies can be applied if the government mandates that individuals must wear masks for health reasons during public health emergencies, and as such will it also constitute “compelled speech” that is also seen as violation of freedom of expression, as freedom of expression does not only refer to the freedom of expression, but it also means that the government cannot force an individual or group to support certain expression. From a comparative perspective and by referring to constitutional cases on anti-masking law in the United States and the proportionality principle in freedom of expression cases applied by the Supreme Court of Canada, this article will attempt to examine the nature of mask wearing and the constitutionality of the Anti-mask Law of Hong Kong based on the three major legal questions at issue raised in the decision of the trial court.
China’s ambitious goal “strive to peak carbon emissions before 2030 and achieve carbon neutrality before 2060” not only shows China’s responsible attitude towards climate change, but also aligns with the upgrade requirement of China’s economy and industries. Since cities occupy a dominant position in China’s population, energy consumption, and carbon emissions, they are the main battlefield for achieving national carbon neutrality. This paper first analyzes the challenges and requirements that cities’ energy systems facing in order to realize carbon neutrality. Then, it takes Macao as an example to analyze the characteristics of cities’ energy consumption and carbon emissions. Finally, it proposes a pathway to realize cities’ carbon neutrality that include four major measures: promote demand-side management in cities’ energy systems; encourage distributed clean energy integration; actively purchase clean electricity from outside of cities; and leverage intelligent techniques for urban energy systems operation & optimization. The proposed pathway can provide a reference for promoting the carbon neutrality for China’s cities.