Nanomaterial-based aptamer sensors for arsenic detection

Arsenic (As) is a highly toxic contaminant in the environment and a serious carcinogen for the human being. The toxicity of arsenic significantly threatens environmental and human health. The effective removing technology for arsenic remains challenging, and one of the reasons is due to the lack of powerful detection method in the complex environmental matrix. There is thus an urgent need to develop novel analytical methods for arsenic, preferably with the potential for the field-testing. To combat arsenic pollution and maintain a healthy environment and eco-system, many advanced analytical methods have been developed for arsenic detection in various samples. Among these strategies, biosensors hold great promise for rapid detection of arsenic, in particular, nanomaterials-based aptamer sensors have attracted significant attention due to their simplicity, high sensitivity and rapidness. In this paper, we reviewed the recent development and promising applications of aptamer sensors (aptasensors) based-on nanomaterial for arsenic detection, in particular with emphasis on the works using optical and electrochemical technologies. We also discussed the recent novel technology in aptasensors development for arsenic detection, including nucleic acid amplification for signal enhancement and device integration for the portability of arsenic sensors. We are hoping this review could inspire further researches in developing novel nanotechnologies based aptasensors for possible on-site detection of arsenic

Nanomaterial-based aptamer sensors for analysis of illicit drugs and evaluation of drugs consumption for wastewater-based epidemiology

The abuse of illicit drugs usually associated with dramatic crimes may cause significant problems for the whole society. Wastewater-based epidemiology (WBE) has been demonstrated to be a novel and cost-effective way to evaluate the abuse of illicit drugs at the community level, and has been used as a routine method for monitoring and played a significant role for combating the crimes in some countries, e.g. China. The method can also provide temporal and spatial variation of drugs of abuse. The detection methods mainly remain on the conventional liquid chromatography coupled with mass spectrometry, which is extremely sensitive and selective, however needs advanced facility and well-trained personals, thus limit it in the lab. As an alternative, sensors have emerged to be a powerful analytical tool for a wide spectrum of analytes, in particular aptamer sensors (aptasensors) have attracted increasing attention and could act as an efficient tool in this field due to the excellent characteristics of selectivity, sensitivity, low cost, miniaturization, easy-to-use, and automation. In this review, we will briefly introduce the context, specific assessment process and applications of WBE and the recent progress of illicit drug aptasensors, in particular focusing on optical and electrochemical sensors. We then highlight several recent aptasensors for illicit drugs in new technology integration and discuss the feasibility of these aptasensor for WBE. We will summarize the challenges and propose our insights and opportunity on aptasensor for WBE to evaluate community-wide drug use trends and public health

Correction of velocity estimation bias caused by phase‐shift beamforming in acoustic Doppler velocity logs

Abstract The performance of Doppler velocity logs (DVLs) in terms of velocity estimate error is directly linked to the geometry of the beam and the pulse transmitted. Beyond a specific transmitted bandwidth, the phase‐shift beamformer can introduce significant errors in velocity estimation. To delineate the operating mechanism of phase‐shift errors within a phased array of acoustic DVLs, the correlation between bottom echo and velocity distribution, in conjunction with the power‐weighted function, was initially examined predicated on spectral estimation theory. Subsequently, numerical and analytical models of the Gaussian‐shaped Doppler spectrum were formulated. The models are employed to evaluate the velocity estimation inaccuracies attributed to phase shifts in extant DVLs, and the comparative results with field experiments corroborate the model's efficacy in forecasting errors. The theoretical findings evaluate the performance limitations of the current phased array transducer design and provide insights for developing new designs. Pool experimental results show that this design effectively reduces the velocity estimation error caused by phase shift under static conditions and in the presence of Doppler frequencies to a level of almost complete elimination of the error compared to conventional configurations

The Impact of Green Technology Innovation on Capital Cost of Heavy Polluting Enterprises: The Mediating Effect of Carbon Performance

Under the background of the carbon peaking and carbon neutrality goals proposed in 2020, making heavy polluting enterprises realize that low-carbon measures can bring enough economic benefits is conducive to enhancing their enthusiasm to adopt green behaviors. Using data from 320 listed companies in heavily polluting industries from 2006 to 2019 as samples, our study used multiple linear regression to explore the relationship between green technology innovation, carbon performance, board characteristics and cost of capital. Based on these data, we draw the following conclusions: green technology innovation and carbon performance are significantly negatively correlated with capital cost, carbon performance plays a mediating role in the relationship between green technology innovation and capital cost, and board characteristics play a moderating role in the relationship between green technology innovation and carbon performance. These conclusions bring some implications for enterprises to develop and implement low-carbon measures and reduce capital cost

Deformation Modes and Anisotropy of Anti-Perovskite Ti3AN (A = Al, In and Tl) from First-Principle Calculations

Deformation modes were studied for Ti3AN (A = Al, In and Tl) by applying strain to the materials using first-principle calculations. The states of the bonds changed during the deformation process, and the Ti-N bonds remained structurally stable under deformation. The elastic anisotropy, electronic structures, hardness, and minimum thermal conductivity of anti-perovskite Ti3AN were investigated using the pseudo potential plane-wave method based on density functional theory. We found that the anisotropy of Ti3InN was significantly larger than that of Ti3AlN and Ti3TlN. All three compounds were mechanically stable. The band structures of the three compounds revealed that they were conductors. The minimum thermal conductivities at high temperature in the propagation directions of [100], [110], and [111] were calculated by the acoustic wave velocity, which indicated that the thermal conductivity was also anisotropic. It is indicated that Ti3InN is a good thermal barrier material

Anti-Biofilm and Anti-Hemolysis Activities of 10-Hydroxy-2-decenoic Acid against <i>Staphylococcus aureus</i>

Persistent infections caused by Staphylococcus aureus biofilms pose a major threat to global public health. 10-Hydroxy-2-decenoic acid (10-HDA), a main fatty acid in royal jelly, has been shown to possess various biological activities. The purpose of this study was to explore the effects of 10-HDA on the biofilms and virulence of S. aureus and its potential molecular mechanism. Quantitative crystal violet staining indicated that 10-HDA significantly reduced the biofilm biomass at sub-minimum inhibitory concentration (MIC) levels (1/32MIC to 1/2MIC). Scanning electron microscope (SEM) observations demonstrated that 10-HDA inhibited the secretion of extracellular polymeric substances, decreased bacterial adhesion and aggregation, and disrupted biofilm architecture. Moreover, 10-HDA could significantly decrease the biofilm viability and effectively eradicated the mature biofilms. It was also found that the hemolytic activity of S. aureus was significantly inhibited by 10-HDA. qRT-PCR analyses revealed that the expressions of global regulators sarA, agrA, and α-hemolysin gene hla were downregulated by 10-HDA. These results indicate that 10-HDA could be used as a potential natural antimicrobial agent to control the biofilm formation and virulence of S. aureus

Exploring the Pharmacological Mechanism of Duhuo Jisheng Decoction in Treating Osteoporosis Based on Network Pharmacology

Objective. The purpose of this work is to study the mechanism of action of Duhuo Jisheng Decoction (DHJSD) in the treatment of osteoporosis based on the methods of bioinformatics and network pharmacology. Methods. In this study, the active compounds of each medicinal ingredient of DHJSD and their corresponding targets were obtained from TCMSP database. Osteoporosis was treated as search query in GeneCards, MalaCards, DisGeNET, Therapeutic Target Database (TTD), Comparative Toxicogenomics Database (CTD), and OMIM databases to obtain disease-related genes. The overlapping targets of DHJSD and osteoporosis were identified, and then GO and KEGG enrichment analysis were performed. Cytoscape was employed to construct DHJSD-compounds-target genes-osteoporosis network and protein-protein interaction (PPI) network. CytoHubba was utilized to select the hub genes. The activities of binding of hub genes and key components were confirmed by molecular docking. Results. 174 active compounds and their 205 related potential targets were identified in DHJSD for the treatment of osteoporosis, including 10 hub genes (AKT1, ALB, IL6, MAPK3, VEGFA, JUN, CASP3, EGFR, MYC, and EGF). Pathway enrichment analysis of target proteins indicated that osteoclast differentiation, AGE-RAGE signaling pathway in diabetic complications, Wnt signaling pathway, MAPK signaling pathway, PI3K-Akt signaling pathway, JAK-STAT signaling pathway, calcium signaling pathway, and TNF signaling pathway were the specifically major pathways regulated by DHJSD against osteoporosis. Further verification based on molecular docking results showed that the small molecule compounds (Quercetin, Kaempferol, Beta-sitosterol, Beta-carotene, and Formononetin) contained in DHJSD generally have excellent binding affinity to the macromolecular target proteins encoded by the top 10 genes. Conclusion. This study reveals the characteristics of multi-component, multi-target, and multi-pathway of DHJSD against osteoporosis and provides novel insights for verifying the mechanism of DHJSD in the treatment of osteoporosis