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The clean production of hydrogen from water using sunlight has emerged as a sustainable alternative toward large-scale energy generation and storage. However, designing photoactive semiconductors that are suitable for both light harvesting and water splitting is a pivotal challenge. Atomically thin transition metal dichalcogenides (TMD) are considered as promising photocatalysts because of their wide range of available electronic properties and compositional variability. However, trade-offs between carrier transport efficiency, light absorption, and electrochemical reactivity have limited their prospects. We here combine two approaches that synergistically enhance the efficiency of photocarrier generation and electrocatalytic efficiency of two-dimensional (2D) TMDs. The arrangement of monolayer WS

Becker nevus (BN) is a benign cutaneous smooth muscle hamartoma that presents with a hyperpigmented patch or plaque with or without hypertrichosis.1 BN may be associated with ipsilateral breast hypoplasia or other musculoskeletal abnormalities, an association which has been termed Becker nevus syndrome (BNS).

In view of the fact that the effects of channel noise are inevitable but easily ignored, we come up with two controlled quantum dialogue(CQD) protocols based on logical Brown states, which are against collective-dephasing and collective-rotation noises, respectively. Compared with existing protocols, there exist several outstanding advantages: firstly, Brown states, as the quantum resource, are the maximally entangled five-qubit states, which own stronger entanglement than GHZ states, W states and cluster states; secondly, the specific quantum circuits are designed to explain how two kinds of logical Brown states, to be strongly against collective noise, are constructed in theory; thirdly, the controller can be offline after quantum resource distribution and permission announcement such that his/her waiting time is effectively reduced; and fourthly, the security analysis manifests that our proposed protocols can not only eliminate the information leakage, but also resist against various well-known attacks, especially the dishonest controller’s attacks.

Cutaneous melanomas may demonstrate a variety of histopathological features and genetic abnormalities. Melanomas that arise in the setting of blue nevi, also known as “malignant blue nevus” or melanoma ex blue nevus (MBN), share similar histopathological and mutational profile with uveal melanoma. The majority of uveal melanomas show characteristic GNA11 or GNAQ mutations; additional BAP1 mutation or loss is associated with the highest risk for metastasis and worst prognosis. However, the significance of BAP1 loss in melanomas ex blue nevus remains unclear. We present a case of melanoma ex blue nevus arising from the scalp of a twenty-one-year-old female. The diagnosis was established on histopathological findings demonstrating a markedly atypical melanocytic proliferation with increased mitotic activity, necrosis, and a focus of angiolymphatic invasion. Immunohistochemical analysis demonstrated the absence of BAP1 nuclear expression within tumor cells. Next Generation Sequencing detected GNA11 Q209L mutation and BAP1 loss (chromosome 3p region loss), supporting the diagnosis. We reviewed another twenty-one MBN cases with reported BAP1 status from the literature. MBN with BAP1 loss presented at a younger average age (41 years versus 61 years), demonstrated larger average lesion thickness (9.0 mm versus 7.3 mm), and had a higher rate of metastasis (50% versus 33%) compared with BAP1-retained MBN. BAP1 expression studies may assist in the diagnosis and management of MBN, but further research is needed.

With the advent of new science and technology, teleconference, which allows multiple participants to communicate directly without being constrained by time and distance, is becoming extremely popular. We put forward two fault tolerant three-party authenticated quantum conference protocols based on channel-encryption against collective-dephasing noise and collective-rotation noise, respectively. Whereafter, we further extend these two protocols to the most common scenario containing n participants. Compared with existing quantum conference protocols, ours own three outstanding merits: firstly, these protocols can meet the requirements of the interactivity of quantum conference well, because the previously shared quantum key can be reused many times; secondly, we introduce an updating mechanism for withstanding the special entanglement attack effectively; and thirdly, an efficient method is presented to realize the distribution of multi-qubit entangled states under collective noise environment.

Polyampholytes, which contain both positive and negative charges along the backbone, represent a classical model system for certain types of ‘intrinsically-disordered proteins’ (IDPs). IDPs can possess biological functionality, even in an unfolded state, including the formation of phase-separated regions within a cell; while driven by a number of interactions, electrostatic attractions are thought to be key to forming these structures. This process of electrostatically-driven liquid–liquid phase separation, known as ‘complex coacervation’, can also be observed in simpler polymer or biopolymer systems. In this paper, we use a series of model polyampholytic polypeptides of increasing blockiness, that undergo ‘self-coacervation’ due to charge attraction between polycation and polyanion blocks along the same polymer chain. We show that these polypeptides undergo complex coacervation when sequences have at least 8–12 adjacent like-charges, with increasing blockiness leading to a larger two-phase region. We simultaneously develop a theory built on the transfer-matrix formalism developed by the authors, to show how blockiness increases the strength of electrostatic interactions and subsequently promote phase separation. We explore a tradeoff that emerges due to the presence of ‘charge-pattern interfaces’ where the sequence of polyampholyte charges switches sign, and how these contrast with chain-ends in equivalent homopolyelectrolyte coacervates.

This dissertation describes a MEMS-based frequency-selective power amplifier that performs both signal filtering and power amplification, while consuming zero power when there is no input, i.e., zero-quiescent power consumption. The frequency-selective power amplifier employs a micromechanical resonant switch (resoswitch) as a key building block similar to those recently used for zero-quiescent power radio receivers, but capable of handling higher powers. This document details the design, fabrication, and characterization of these higher frequency and higher power micromechanical resoswitches, and employs them as power amplifiers. Here, the mechanical Q of the resoswitch largely governs the threshold input level that instigates power gain. Theoretical and experimental studies of Q, as well as Q enhancement techniques and high-Q structural design, are discussed. Further, post-fabrication laser trimming addresses the frequency accuracy of the vibrating devices. A model that replaces laser blasted holes with stiffness-modifying cracks captures well the frequency shift dependence on laser blast location. The accuracy of this theory further enables a deterministic trimming protocol that specifies the laser targeting sequence needed to achieve a required amount of frequency tuning with minimal Q reduction. The resoswitch used to demonstrate the frequency-selective power amplifier employs slots to engineer stiffness along orthogonal axes of a wine-glass disk resonator structure. The slots realize displacement amplification—a larger displacement magnitude along the output than the input axis—allowing impact switching only to the output electrodes, not the input, all of which improves reliability. A finite element analysis (FEA)-based model predicts the displacement gain as a function of disk size and slot dimension/location.To improve impact contact resistance, this work employs metal for the slotted-disk resoswitch, achieved via a CMOS-compatible surface micromachining process that essentially replaces normally-used polysilicon material with aluminum metal, which serves as both structural and interconnect material. This not only improves contact resistance, but also reduces parasitic resistance, which in turn reduces feedthrough currents. When embedded in a switched-mode power amplifier circuit, the Al displacement-amplifying resoswitch performs signal filtering and power amplification that first filters an incoming signal with channel-like selectivity and then amplifies the signal with a power gain of 13.8 dB. More importantly, unlike transistor-based circuits, the resoswitch-based frequency-selective power amplifier consumes zero power while in standby. Measurements indicate that sputtered aluminum has high mechanical Q at low frequencies, as a folded-beam capacitive-comb-driven micromechanical resonator fabricated via the aforementioned process achieved a Q up to ∼20,000. Unfortunately, the higher frequency slotted-disk used in the displacement amplifier did not fare as well, as its Q was only on the order of 1,000. An effort to study the Q limits of different resoswitch designs included an experimental study of intrinsic loss mechanisms using cryogenic operation to enhance resonator Q and better elucidate important energy loss mechanisms. Here, operation of a 61-MHz wine-glass disk resonator at temperatures as low as 5K reduces temperature-dependent energy loss and raises Q to as high as 362,000, likely devoid of thermoelastic friction. On the other hand, introduction of slots into a wine-glass disk structure (to effect displacement gain) reduces Q by introducing thermoelasting damping, which this document models in detail. A displacement-amplifying elliptic disk solves this problem by deriving gain-induced stiffness differences from geometric ratioing rather than Q-degrading slots, which permits simultaneous displacement gain and high-Q. Finally, this work includes a study of laser trimming to trim power amplifier frequency to a desired range. Here, laser trimming offers flexible bidirectional frequency tuning with minimal effect on Q. Unlike other frequency tuning methods, laser trimming does not require added process steps, e.g., sputtering of frequency-shifting metal materials on structures. Rather, laser trimming offers precise post-fabrication frequency adjustment via blasts of controlled size and location on a given resonator. A model that captures the frequency shift dependency on laser blast location shows good agreement with measured results on micromechanical clamped-clamped (CC)-beam resonators. The theory provides a modeling framework for laser trimming applicable to other types of beam resonators, e.g., free-free beams, cantilevers, and even disks or rings by altering the boundary condition matrices.

This study integrates wearable devices and non-contact measurements to develop a mirror-based personal health monitoring system. Under user permission, we use Google Fit REST API to retrieve his/her activity history, including steps taken, calories burned, heart rate, and sleep data. All the physiological data are then visualized on the monitor with a bar chart, making user easily and quickly understand the historical behavior. We also integrate non-contact heart rate and respiratory rate real-time measurement and then evaluate the heart rate measurement accuracy through continuously comparing with the retrieved data from smart bracelets. Hope this device can be used for home health data collection and monitoring to assist the doctor to provide the appropriate diagnosis and treatment.

[Image: see text] Charged polymers are ubiquitous in biological systems because electrostatic interactions can drive complicated structure formation and respond to environmental parameters such as ionic strength and pH. In these systems, function emerges from sophisticated molecular design; for example, intrinsically disordered proteins leverage specific sequences of monomeric charges to control the formation and function of intracellular compartments known as membraneless organelles. The role of a charged monomer sequence in dictating the strength of electrostatic interactions remains poorly understood despite extensive evidence that sequence is a powerful tool biology uses to tune soft materials. In this article, we use a combination of theory, experiment, and simulation to establish the physical principles governing sequence-driven control of electrostatic interactions. We predict how arbitrary sequences of charge give rise to drastic changes in electrostatic interactions and correspondingly phase behavior. We generalize a transfer matrix formalism that describes a phase separation phenomenon known as “complex coacervation” and provide a theoretical framework to predict the phase behavior of charge sequences. This work thus provides insights into both how charge sequence is used in biology and how it could be used to engineer properties of synthetic polymer systems.