Carbon nanotubes (CNTs) and graphene have attracted great attention for numerous applications for future flexible electronics, owing to their supreme properties including exceptionally high ...electronic conductivity and mechanical strength. Here, the progress of CNT‐ and graphene‐based flexible thin‐film transistors from material preparation, device fabrication techniques to transistor performance control is reviewed. State‐of‐the‐art fabrication techniques of thin‐film transistors are divided into three categories: solid‐phase, liquid‐phase, and gas‐phase techniques, and possible scale‐up approaches to achieve realistic production of flexible nanocarbon‐based transistors are discussed. In particular, the recent progress in flexible all‐carbon nanomaterial transistor research is highlighted, and this all‐carbon strategy opens up a perspective to realize extremely flexible, stretchable, and transparent electronics with a relatively low‐cost and fast fabrication technique, compared to traditional rigid silicon, metal and metal oxide electronics.
The progress of carbon nanotube‐ and graphene‐based flexible thin‐film transistors from material preparation, device fabrication techniques to transistor performance control is reviewed. State‐of‐the‐art fabrication techniques of thin‐film transistors are divided into three categories and possible scale‐up approaches to achieve realistic production of flexible nanocarbon‐based transistors are discussed. The recent progress in flexible all‐carbon nanomaterial transistor research is highlighted.
Online consumer comments can reduce the uncertainty of consumers' purchasing behaviors and provide much more important reference for consumers to make purchasing decisions, and some online consumer ...comments have the positive and negative effects, and then some online retailers often take different actions to respond to consumers' online comments. To describe and analyze the influence mechanism of online comments on the consumers and retailers, we establish a two‐stage theoretical model by introducing product–demand mismatch and exploit it to analyze the impact of different quality online comments on online retailer and discuss the online retailer's decisions.
Exposure to even very low levels of lead, cadmium, and mercury ions is known to cause neurological, reproductive, cardiovascular, and developmental disorders, which are more serious problems for ...children particularly. Accordingly, great efforts have been devoted to the development of fluorescent and colorimetric sensors, which can selectively detect lead, cadmium, and mercury ions. In this
critical review
, the fluorescent and colorimetric sensors are classified according to their receptors into several categories, including small molecule based sensors, calixarene based chemosensors, BODIPY based chemosensors, polymer based chemosensors, DNA functionalized sensing systems, protein based sensing systems and nanoparticle based sensing systems (197 references).
This critical review focuses on the fluorescent or colorimetric sensors for lead, cadmium, and mercury ions, which are categorized as small molecule based sensors, calixarene based chemosensors, BODIPY based chemosensors, polymer based chemosensors, DNA functionalized sensing systems, protein based sensing systems and nanoparticle based sensing systems.
Janus two-dimensional (2D) materials have attracted much attention as they possess unique properties caused by their out-of-plane asymmetry, and have been achieved in many 2D families. In this work, ...Janus monolayers are predicted for a new 2D MA2Z4 family by means of first-principles calculations, of which MoSi2N4 and WSi2N4 have been synthesized experimentally (Science, 2020, 369, 670–674). The predicted MSiGeN4 (M = Mo and W) monolayers exhibit dynamical, thermodynamic and mechanical stability, and they are indirect band-gap semiconductors. The inclusion of spin–orbit coupling (SOC) gives rise to Rashba-type spin splitting, which is observed in the valence bands, which are different from the common conduction bands. The calculated results show valley polarization due to SOC, together with inversion symmetry breaking. It is found that MSiGeN4 (M = Mo and W) monolayers have much higher electron mobilities with respect to the hole mobilities. Both in-plane and much weaker out-of-plane piezoelectric polarizations can be observed when a uniaxial strain is applied in the basal plane. The values of the piezoelectric strain coefficient d11 of the Janus MSiGeN4 (M = Mo and W) monolayers fall in between those of the MSi2N4 (M = Mo and W) and MGe2N4 (M = Mo and W) monolayers, as expected. It is proved that strain can tune the positions of the valence band maximum (VBM) and the conduction band minimum (CBM), and can enhance the strength of the conduction band convergence caused by compressive strain. It is also found that tensile biaxial strain can enhance the d11 of the MSiGeN4 (M = Mo and W) monolayers, and the compressive strain can improve the d31 (absolute values). Our predicted MSiGeN4 (M = Mo and W) monolayers, as derivatives of the 2D MA2Z4 family, enrich the field of Janus 2D materials, and these results can motivate related experimental work.
Although nonparametric methods in genome-wide association studies (GWAS) are robust in quantitative trait nucleotide (QTN) detection, the absence of polygenic background control in single-marker ...association in genome-wide scans results in a high false positive rate. To overcome this issue, we proposed an integrated nonparametric method for multi-locus GWAS. First, a new model transformation was used to whiten the covariance matrix of polygenic matrix K and environmental noise. Using the transferred model, Kruskal-Wallis test along with least angle regression was then used to select all the markers that were potentially associated with the trait. Finally, all the selected markers were placed into multi-locus model, these effects were estimated by empirical Bayes, and all the nonzero effects were further identified by a likelihood ratio test for true QTN detection. This method, named pKWmEB, was validated by a series of Monte Carlo simulation studies. As a result, pKWmEB effectively controlled false positive rate, although a less stringent significance criterion was adopted. More importantly, pKWmEB retained the high power of Kruskal-Wallis test, and provided QTN effect estimates. To further validate pKWmEB, we re-analyzed four flowering time related traits in Arabidopsis thaliana, and detected some previously reported genes that were not identified by the other methods.
Chronic pain is caused by cellular damage with an obligatory inflammatory component. In response to noxious stimuli, high levels of ATP leave according to their concentration gradient, the ...intracellular space through discontinuities generated in the plasma membrane or diffusion through pannexin-1 hemichannels, and activate P2X7Rs localized at peripheral and central immune cells. Because of the involvement of P2X7Rs in immune functions and especially the initiation of macrophage/microglial and astrocytic secretion of cytokines, chemokines, prostaglandins, proteases, reactive oxygen, and nitrogen species as well as the excitotoxic glutamate/ATP, this receptor type has a key role in chronic pain processes. Microglia are equipped with a battery of pattern recognition receptors that detect pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide (LPS) from bacterial infections or danger associated molecular patterns (DAMPs) such as ATP. The co-stimulation of these receptors leads to the activation of the NLRP3 inflammasome and interleukin-1β (IL-1β) release. In the present review, we invite you to a journey through inflammatory and neuropathic pain, primary headache, and regulation of morphine analgesic tolerance, in the pathophysiology of which P2X7Rs are centrally involved. P2X7R bearing microglia and astrocyte-like cells playing eminent roles in chronic pain will be also discussed.
Many problems regarding channel conflicts exist in the pricing process of a manufacturer‐led dual‐channel supply chain. By considering the fact that online reviews and channel preferences are the ...important factors that influence consumer purchasing behaviors and the decision‐making of the supply chain, this paper deals with these problems through the development of a model involving online reviews and channel preferences. It then analyzes optimal decisions under either decentralized or centralized decision‐making scenarios. The impact of online review service input and consumer channel preference on optimal supply chain decisions and profits is further analyzed. Finally, based on the developed model, a revenue sharing contract coordination scheme is designed to achieve Pareto improvements in the supply chain. The results show that the degree of consumer preference for online channels affects the best consumer decisions and the overall profit of the supply chain. The impact coefficient of online reviews is positively correlated with the manufacturer's direct selling price, the level of input to online review services, and the profit of the entire supply chain. The provision of online review services can significantly increase channel prices, market sales, and profits compared to channel preferences. The overall profit of the supply chain under centralized decision‐making is significantly greater than that under decentralized decision‐making, and the coordination model can effectively coordinate the supply chain and alleviate conflicts.
Genome-wide association studies (GWAS) have been widely used in genetic dissection of complex traits. However, common methods are all based on a fixed-SNP-effect mixed linear model (MLM) and single ...marker analysis, such as efficient mixed model analysis (EMMA). These methods require Bonferroni correction for multiple tests, which often is too conservative when the number of markers is extremely large. To address this concern, we proposed a random-SNP-effect MLM (RMLM) and a multi-locus RMLM (MRMLM) for GWAS. The RMLM simply treats the SNP-effect as random, but it allows a modified Bonferroni correction to be used to calculate the threshold p value for significance tests. The MRMLM is a multi-locus model including markers selected from the RMLM method with a less stringent selection criterion. Due to the multi-locus nature, no multiple test correction is needed. Simulation studies show that the MRMLM is more powerful in QTN detection and more accurate in QTN effect estimation than the RMLM, which in turn is more powerful and accurate than the EMMA. To demonstrate the new methods, we analyzed six flowering time related traits in Arabidopsis thaliana and detected more genes than previous reported using the EMMA. Therefore, the MRMLM provides an alternative for multi-locus GWAS.
Herein graphene oxide/Ag nanoparticle hybrids (GO/PDDA/AgNPs) were fabricated according to a self-assembly procedure. Using the obtained GO/PDDA/AgNPs as SERS substrates, an ultrasensitive and ...label-free detection of folic acid in water and serum was demonstrated based on the inherent SERS spectra of folic acid. The modified graphene oxide exhibited strong enrichment of folic acid due to the electrostatic interaction, and the self-assembled Ag nanoparticles greatly enhanced the SERS spectra of folic acid, both of which led to an ultrahigh sensitivity. Therefore, although the SERS enhancement of p-ATP on GO/PDDA/AgNPs was weaker than that on Ag nanoparticles, the SERS signals of folic acid on GO/PDDA/AgNPs were much stronger than that on Ag nanoparticles. To improve the detection, the concentration of GO/PDDA/AgNPs was optimized to reduce background of the graphene oxide. The SERS spectra of the folic acid showed that the minimum detected concentration of folic acid in water was as low as 9 nM with a linear response range from 9 to 180 nM. To estimate the feasibility of the detection method based on GO/PDDA/AgNPs for the practical applications, diluted serum containing different concentrations of folic acid was taken as real samples. It was established that the sensitivity and the linear range for the folic acid in serum were comparable to that in water. This ultrasensitive and label-free SERS detection of folic acid based on GO/PDDA/AgNPs offers great potential for practical applications of medicine and biotechnology.
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