HCB: Enabling Compact Block in Ethereum Network with Secondary Pool and Transaction Prediction

Compact block, which replaces transactions in the block with their hashes, is an effective means to speed up block propagation in the Bitcoin network. The compact block mechanism in Bitcoin counts on the fact that many nodes may already have the transactions (or most of the transactions) in the block, therefore sending the complete block containing the full transactions is unnecessary. This fact, however, does not hold in the Ethereum network. Adopting compact block directly in Ethereum may degrade the block propagation speed significantly because the probability of a node not having a transaction in the sending block is relatively high in Ethereum and requesting the missing transactions after receiving the compact block takes much additional time. This paper proposes hybrid-compact block (HCB), an efficient compact block propagation scheme for Ethereum and other similar blockchains. First, we develop a Secondary Pool to store the low-fee transactions, which are removed from the primary transaction pool, to conserve storage space. As simple auxiliary storage, the Secondary Pool does not affect the normal block processing of the primary pool in Ethereum. Second, we design a machine learning-based transaction prediction module to precisely predict the missing transactions caused by network latency and selfish behaviors. We implemented our HCB scheme and other compact-block-like schemes (as benchmarks) and deployed a number of worldwide nodes over the Ethereum MainNet to experimentally investigate them. Experimental results show that HCB performs best among the existing compact-block-like schemes and can reduce propagation time by more than half with respect to the current block propagation scheme in Ethereum

Array atomic force microscopy for real-time multiparametric analysis.

Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe-sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks

Monitoring of the central blood pressure waveform via a conformal ultrasonic device.

Continuous monitoring of the central-blood-pressure waveform from deeply embedded vessels, such as the carotid artery and jugular vein, has clinical value for the prediction of all-cause cardiovascular mortality. However, existing non-invasive approaches, including photoplethysmography and tonometry, only enable access to the superficial peripheral vasculature. Although current ultrasonic technologies allow non-invasive deep-tissue observation, unstable coupling with the tissue surface resulting from the bulkiness and rigidity of conventional ultrasound probes introduces usability constraints. Here, we describe the design and operation of an ultrasonic device that is conformal to the skin and capable of capturing blood-pressure waveforms at deeply embedded arterial and venous sites. The wearable device is ultrathin (240 μm) and stretchable (with strains up to 60%), and enables the non-invasive, continuous and accurate monitoring of cardiovascular events from multiple body locations, which should facilitate its use in a variety of clinical environments

Ultrasonic device for blood pressure measurement

This research will develop a method for continuous, accurate, and non-invasive central blood pressure waveform recording using a stretchable ultrasound device worn on the human skin. Continuous central blood pressure waveform monitoring provides critical and direct diagnostic clues to cardiovascular pathological conditions, and can raise patient awareness, help preventive care, and serve as the basis for personalized medicine. This research is distinct from other blood pressure waveform measurement methods because it provides accurate waveform data with a non-invasive device that does not constrict natural body movement or cause discomfort. The proposed research is one of the first studies to use a wearable system to capture medical data underneath the skin. It will be the first study to implement the ultrasound functionality in stretchable electronics. We will demonstrate, by combined innovative strategies in materials science, mechanical design, and electronics integration, a stretchable transducer array based on piezoelectric materials that detect the blood vessel diameter changes and translates the information into blood pressure waveforms. We will first design and optimize the performance of a single ultrasonic transducer for measuring the central blood pressure waveform. Then, we will develop phased array control algorithm on a stretchable platform for enabling beam focusing and improving sensitivity. In the final phase of this research, we will integrate a stretchable transducer array with the phased array control algorithm for continuous and accurate blood pressure waveform monitoring. The use of a soft, stretchable platform that matches the softness of the human skin will make a key difference in patient acceptance in high-risk populations and in wellness monitoring for the general public, with a direct impact on clinical and preventive care practices. The easy access to blood pressure waveforms will shift the public perception of the concept of blood pressure and provide unprecedented data for medical professionals, which translates into a significant reduction in associated mortality and healthcare costs

Ultrasonic device for blood pressure measurement

This research will develop a method for continuous, accurate, and non-invasive central blood pressure waveform recording using a stretchable ultrasound device worn on the human skin. Continuous central blood pressure waveform monitoring provides critical and direct diagnostic clues to cardiovascular pathological conditions, and can raise patient awareness, help preventive care, and serve as the basis for personalized medicine. This research is distinct from other blood pressure waveform measurement methods because it provides accurate waveform data with a non-invasive device that does not constrict natural body movement or cause discomfort. The proposed research is one of the first studies to use a wearable system to capture medical data underneath the skin. It will be the first study to implement the ultrasound functionality in stretchable electronics. We will demonstrate, by combined innovative strategies in materials science, mechanical design, and electronics integration, a stretchable transducer array based on piezoelectric materials that detect the blood vessel diameter changes and translates the information into blood pressure waveforms. We will first design and optimize the performance of a single ultrasonic transducer for measuring the central blood pressure waveform. Then, we will develop phased array control algorithm on a stretchable platform for enabling beam focusing and improving sensitivity. In the final phase of this research, we will integrate a stretchable transducer array with the phased array control algorithm for continuous and accurate blood pressure waveform monitoring. The use of a soft, stretchable platform that matches the softness of the human skin will make a key difference in patient acceptance in high-risk populations and in wellness monitoring for the general public, with a direct impact on clinical and preventive care practices. The easy access to blood pressure waveforms will shift the public perception of the concept of blood pressure and provide unprecedented data for medical professionals, which translates into a significant reduction in associated mortality and healthcare costs

An improved ultrasonic computerized tomography (UCT) technique for damage localization based on compressive sampling (CS) theory

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/172332/1/stc2938.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/172332/2/stc2938_am.pd

A Three-Dimensional Inorganic Analogue of 9,10-Diazido-9,10-Diboraanthracene: A Lewis Superacidic Azido Borane with Reactivity and Stability

Herein, we report the facile synthesis of a three-dimensional (3D) inorganic analogue of 9,10-diazido-9,10-dihydrodiboraantracene, which turned out to be a monomer in both the solid and solution state, and thermally stable up to 230 °C, representing a rare example of azido borane with boosted Lewis acidity and stability in one. Apart from the classical acid-base and Staudinger reactions, E−H bond activation (E=B, Si, Ge) was investigated. While the reaction with B−H (9-borabicyclo[3.3.1]nonane) led directly to the 1,1-addition on N$_{α}$ upon N$_{2}$ elimination, the Si−H (Et$_{3}$SiH, PhMe$_{2}$SiH) activation proceeded stepwise via 1,2-addition, with the key intermediates 5$_{int}$ and 6$_{int}$ being isolated and characterized. In contrast, the cooperative Ge−H was reversible and stayed at the 1,2-addition step