Stretchable Piezoelectric Sensing Systems for Self-Powered and Wireless Health Monitoring

Continuous monitoring of human physiological signals is critical to managing personal healthcare by early detection of health disorders. Wearable and implantable devices are attracting growing attention as they show great potential for real-time recording of physiological conditions and body motions. Conventional piezoelectric sensors have the advantage of potentially being self-powered, but have limitations due to their intrinsic lack of stretchability. Herein, a kirigami approach to realize a novel stretchable strain sensor is introduced through a network of cut patterns in a piezoelectric thin film, exploiting the anisotropic and local bending that the patterns induce. The resulting pattern simultaneously enhances the electrical performance of the film and its stretchability while retaining the mechanical integrity of the underlying materials. The power output is enhanced from the mechano-electric piezoelectric sensing effect by introducing an intersegment, through-plane, electrode pattern. By additionally integrating wireless electronics, this sensing network could work in an entirely battery-free mode. The kirigami stretchable piezoelectric sensor is demonstrated in cardiac monitoring and wearable body tracking applications. The integrated soft, stretchable, and biocompatible sensor demonstrates excellent in vitro and ex vivo performances and provides insights for the potential use in myriad biomedical and wearable health monitoring applications

Large-Scale in Vitro Transcription, RNA Purification and Chemical Probing Analysis

Background/Aims: RNA elements such as catalytic RNA, riboswitch, microRNA, and long non coding RNA (lncRNA) play central roles in many cellular processes. Studying diverse RNA functions require large quantities of RNA for precise structure analysis. Current RNA structure and function studies can benefit from improved RNA quantity and quality, simpler separation procedure and enhanced accuracy of structural analysis. Methods: Here we present an optimized protocol for analyzing the structure of any RNA, including in vitro transcription, size-exclusion chromatography (SEC) based denaturing purification and improved secondary structure analysis by chemical probing. Results: We observed that higher Mg2+, nucleoside triphosphate (NTP) concentrations and longer reaction duration can improve the RNA yield from in vitro transcription, specifically for longer and more complicated constructs. Our improved SEC-based denaturing RNA purification effectively halved the experiment duration and labor without introducing any contaminant. Finally, this study increased the accuracy and signal-to-noise ratio (SNR) of selective 2′-hydroxyl acylation analyzed by primer extension (SHAPE) chemical probing for analyzing RNA structure. Conclusion: Part or all of our modified method can improve almost any RNA-related study from protein-RNA interaction analysis to crystallography

Enhancing endogenous adenosine A2A receptor signaling induces slow-wave sleep without affecting body temperature and cardiovascular function

Insomnia is one of the most common sleep problems with an estimated prevalence of 10%–15% in the general population. Although adenosine A2A receptor (A2AR) agonists strongly induce sleep, their cardiovascular effects preclude their use in treating sleep disorders. Enhancing endogenous A2AR signaling, however, may be an alternative strategy for treating insomnia, because adenosine levels in the brain accumulate during wakefulness. In the present study, we found that 3,4-difluoro-2-((2-fluoro-4-iodophenyl)amino)benzoic acid, denoted A2AR positive allosteric modulator (PAM)-1, enhanced adenosine signaling at the A2AR and induced slow wave sleep (SWS) without affecting body temperature in wild-type male mice after intraperitoneal administration, whereas the SWS-inducing effect of this benzoic acid derivative was abolished in A2AR KO mice. In contrast to the A2AR agonist CGS 21680, the A2AR PAM-1 did not affect blood pressure or heart rate. These findings indicate that enhancing A2AR signaling promotes SWS without cardiovascular effects. Therefore, small molecules that allosterically modulate A2ARs could help people with insomnia to fall asleep

Research on Competitiveness of China’s Social Commerce Enterprises Based on Macro- and Micro-Niche

Imbalance of development and resources allocation can emerge during the rapid expansion of social commerce enterprises, which significantly reduces their competitiveness and sustainability. In this paper, we put forward the concept of social commerce ecosystem and propose a model composed of macro-niche and micro-niche to empirically analyze the performance of different social commerce enterprises in China. The results show that: (1) The social sharing e-commerce sub-industry is a monopoly market while the social retail e-commerce sub-industry tends to be a perfectly competitive market; (2) Compared with using only macro-niche or micro-niche, our model shows a more comprehensive insight of enterprise competitiveness, which provides a better niche evaluation for other industries

Wave Dispersion in One-Dimensional Nonlinear Local Resonance Phononic Crystals with Perturbation Method

Nonlinear phononic crystals are receiving increasingly greater attention in the field of sound absorption and vibration reduction. In this paper, we use the perturbation method to investigate elastic wave propagation in one-dimensional discrete local resonance nonlinear phononic crystals. The nonlinear force on the inner resonator is expressed in the form of a linear part plus a cubic nonlinear fluctuation. By combining Bloch wave theory and the perturbation method, the nonlinear dispersion relation is obtained by a first-order approximate analytical solution. The results show that the band’s cut-off frequency is not only affected by the degree of nonlinearity but is closely related to the wave amplitude. In addition, the finite element method is used for comparison and verification. Finally, an application example of a wave filter is provided based on the nonlinear characteristics

Optimal marketing channel and strategy in social commerce

This paper aims to explore the optimal marketing channel of e-commerce enterprises with various consumer base size and product added-value in social commerce. By characterizing the consumer utility, we construct decision-making models of e-commerce enterprises under the traditional e-commerce platform (TECP) and two kinds of social commerce marketing channels involving “e-commerce platform + social” (ECPS) and “social media + business’ (SMB). Then, we obtain the optimal strategy of e-commerce enterprises for each channel by using the Karush–Kuhn–Tucker (KKT) conditions, and verify the effectiveness of the corollaries by numerical simulation. Results find that social commerce marketing channels (ECPS and SMB) are not necessarily better than TECP. For e-commerce enterprises with low consumer base size and low product added-value, the TECP channel offers the largest profit. Besides, SMB is the preferred marketing channel for most e-commerce enterprises

Red blood cell distribution width/platelet ratio on admission as a predictor for in-hospital mortality in patients with acute myocardial infarction: a retrospective analysis from MIMIC-IV Database

Abstract Background Red blood cell distribution width (RDW) to platelet ratio (RPR) is a novel inflammatory indicator. It integrates the risk prediction of RDW and platelet, which is associated with adverse outcomes. However, the predictive power of RPR in mortality for patients with acute myocardial infarction (AMI) remains uncertain. Thus, we aimed to explore the association between RPR and 180-day in-hospital mortality in patients with AMI. Methods Data on patients with AMI were extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients were divided into two groups according to the optimal RPR cut-off value. The survival curve between high and low RPR groups was plotted via the Kaplan-Meier (KM) method. Univariate and multivariate Cox regression analyses were performed to determine the association between RPR on admission and 180-day in-hospital mortality. Results A total of 1266 patients were enrolled, of which 83 (6.8%) died within 180 days during the hospitalization. Compared with the survivor group, the non-survivor group had higher RPR on admission (0.11 ± 0.07 vs. 0.08 ± 0.06, P < 0.001). The KM curve indicated that the survival probability of low RPR group was higher than that of high RPR group. Multivariate Cox regression analysis demonstrated that higher RPR on admission was an independent and effective predictor of 180-day mortality in patients with AMI (hazard ratio [HR]: 2.677, 95% confidence interval [CI]: 1.159–6.188, P = 0.021). Conclusion Higher RPR was associated with higher in-hospital 180-day mortality in patients with AMI

Dual-Channel Probe of Carbon Dots Cooperating with Lanthanide Complex Employed for Simultaneously Distinguishing and Sequentially Detecting Tetracycline and Oxytetracycline

Tetracycline (TC) and oxytetracycline (OTC) are the most widely used broad-spectrum antimicrobial agents in tetracycline drugs, and their structures and properties are very similar, so it is a great challenge to distinguish and detect these two antibiotics with a single probe at the same time. Herein, a dual-channel fluorescence probe (SiCDs@mMIPs-cit-Eu) was developed by integrating two independent reaction sites with SiCDs-doped mesoporous silica molecular imprinting group and europium complex group into a nanomaterial. The synergistic influence of inner filter effect and &ldquo;antenna effect&rdquo; can be guaranteed to solve the distinction between TC and OTC. Moreover, this novel strategy can also sequentially detect TC and OTC in buffer solution and real samples with high sensitivity and selectivity. This method revealed good responses to TC and OTC ranging from 0 to 5.5 &mu;M with a detection limit of 5 and 16 nM, respectively. Combined with the smartphone color-scanning application, the portable and cheap paper-based sensor was designed to realize the multi-color visual on-site detection of TC and OTC. In addition, the logic gate device was constructed according to the fluorescence color change of the probe for TC and OTC, which provided the application possibility for the intelligent detection of the probe

The impact force identification of composite stiffened panels under material uncertainty

Aeronautical Science Foundation of China [2012ZA52001]; Specialized Research Fund for the Doctoral Program of Higher Education [20123218120005]This paper presents a synthesis approach to address the problem of uncertainty in the impact force identification. The effects of material uncertainty on dynamic responses of the structure are studied by using Monte Carlo simulation. Six parameters, including mechanical properties and thermal coefficients, are considered as independent random variables. A parametric study is conducted to select four parameters as the optimization variables in the following step of model updating. The technique of model updating is used to correct the modeling errors caused by material uncertainty. Then, an improved inverse analysis technique based on the finite element method and mode superposition method is taken for impact force identification. In this study, the present method is performed on a composite stiffened panel, and the effect of noise on the performance of identification is also discussed. The results of the study show that the developed approach is capable of identifying the impact location and reconstructing the force history accurately by reducing material uncertainty through the modal updating procedure. (C) 2013 Elsevier B.V. All rights reserve