•First demonstrate a liquid crystal biosensor based on whispering gallery mode lasing for detection of acetylcholinesterase and its inhibitors.•The limit of detection achieved was as low as 0.1 pg/mL ...for fenobucarb and 1 pg/mL for dimethoate.•Compared with POM observations, the direct measurements from the lasing spectra of LC microdroplets provides more quantitative and more sensitive detection of reaction analytes.•The proposed biosensor also retains a detection performance in real river water.
In this work, a liquid crystal (LC) biosensor based on whispering gallery mode (WGM) lasing is reported and demonstrated for real-time and high-sensitive detection of acetylcholinesterase (AChE) and its inhibitors. Benefit from the double amplification by the WGM resonance and the 5CB molecules, small changes in biological processes are significantly enhanced in WGM spectral responses. The spectral responses provide direct information about the molecular adsorption/desorption at the LC/aqueous solution interface and can be used as an indicator of the enzymatic reaction. The limit of detection achieved was as low as 0.1 pg/mL for fenobucarb and 1 pg/mL for dimethoate, which is considerably lower than the standard levels of pesticides specified for water quality standards. Results indicate that this versatile method holds prospects for application in real-time and high-sensitive monitoring of biochemical reactions and can serve as an alternative solution to compensate for missing capabilities in conventional POM observations.
We demonstrate a detection method for heavy metal (HM) ions based on whispering gallery mode (WGM) lasing in a liquid crystal (LC) microdroplet biosensor. By doping with stearic acid, nematic LC ...4-cyano-4'-pentylbiphenyl (5CB) microdroplets are biochemically functionalized and used as both optical microresonators and sensing elements. Typical WGM lasing emission is observed in stearic acid-doped 5CB microdroplets under a pulse laser pump. Our results show that quantitative spectral shift of WGMs can serve as a real-time indicator of the adsorption of HM ions on the microdroplet surface. The detection limit of our sensor is as low as 40 pM for Cu(II) ions, six orders of magnitude better than the exposure threshold defined by the World Health Organization. Furthermore, this sensing system has an ability to discriminate between heavy and light metal ions. We believe that this novel biosensor has great application potential for environmental monitoring and drinking water quality testing.
Short-chain fatty acids (SCFAs) derived from the fermentation of carbohydrates by gut microbiota play a crucial role in regulating host physiology. Among them, acetate, propionate, and butyrate are ...key players in various biological processes. Recent research has revealed their significant functions in immune and inflammatory responses. For instance, butyrate reduces the development of interferon-gamma (IFN-γ) generating cells while promoting the development of regulatory T (Treg) cells. Propionate inhibits the initiation of a Th2 immune response by dendritic cells (DCs). Notably, SCFAs have an inhibitory impact on the polarization of M2 macrophages, emphasizing their immunomodulatory properties and potential for therapeutics. In animal models of asthma, both butyrate and propionate suppress the M2 polarization pathway, thus reducing allergic airway inflammation. Moreover, dysbiosis of gut microbiota leading to altered SCFA production has been implicated in prostate cancer progression. SCFAs trigger autophagy in cancer cells and promote M2 polarization in macrophages, accelerating tumor advancement. Manipulating microbiota- producing SCFAs holds promise for cancer treatment. Additionally, SCFAs enhance the expression of hypoxia-inducible factor 1 (HIF-1) by blocking histone deacetylase, resulting in increased production of antibacterial effectors and improved macrophage-mediated elimination of microorganisms. This highlights the antimicrobial potential of SCFAs and their role in host defense mechanisms. This comprehensive review provides an in-depth analysis of the latest research on the functional aspects and underlying mechanisms of SCFAs in relation to macrophage activities in a wide range of diseases, including infectious diseases and cancers. By elucidating the intricate interplay between SCFAs and macrophage functions, this review aims to contribute to the understanding of their therapeutic potential and pave the way for future interventions targeting SCFAs in disease management.
Ulcerative colitis is a chronic, idiopathic, and inflammatory disease of the rectal and colonic mucosa, the behavior of which is of heterogeneity in individuals. Here, we explored the ...multifactor-mediated functional modules associated with ulcerative colitis classification in the whole genome. Datasets downloaded from the GEO database were used to identify differentially expressed genes between ulcerative colitis patients and healthy individuals initially, followed by acquisition of the remaining ulcerative colitis -related genes from the OMIM and STRING databases. The results identified 914 ulcerative colitis-related genes, of which 60 were differentially expressed genes obtained from GEO datasets. Through weighted co-expression network analysis of ulcerative colitis-related genes, four modules were obtained, three of which were related to ulcerative colitis. Following interactions between microRNA, long noncoding RNA, transcription factors, and module hub genes were predicted and used to construct ulcerative colitis multifactor networks. Additionally, we performed consensus clustering of the ulcerative colitis samples. The results revealed that ulcerative colitis could be divided into four subtypes, with six hub genes identified as potential biomarkers for classification. These findings offer novel insights into ulcerative colitis and a basis for disease classification of ulcerative colitis.
An underwater propulsion microsystem is proposed in this work, which employs a nanosecond laser pulse out from the tapered fiber tip. Noteworthily, the system can generate a directional shock wave ...(or plasma) to propel the polystyrene (PS) microsphere. Through simulation, the shock wave propagation characteristics and the bubble dynamic are investigated. Experimentally, high-speed photography method is employed to obtain the motion image of microsphere. The results show that the propulsion efficiency is dependent on the laser energy. Meanwhile, we explain the role of the bubble dynamic process in propelling microsphere, and find that the bubble diameter increases with the laser energy. In addition, an experiment is performed to separate and remove the PS microsphere clusters in water at fixed point. Compared with conventional technology, this new method has advantages of high controllability, directional and non-contact, and can be used for directional manipulation of underwater microstructures and removal of contaminated microspheres in water environments.
Magnesium alloys have received more attention as orthopedic repair materials, while their rapid degradation and susceptibility to bacterial infections limit their clinical medical applications. In ...this study, the layered double hydroxide/hydroxyapatite (LDH/HAp) composite coating was first prepared by hydrothermal method, and then ciprofloxacin (CIP) was loaded on LDH/HAp by the traditional immersion method. Composite coatings were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) techniques. The LDH/HAp-CIP coating has a more excellent inhibitory effect on the activity of
Staphylococcus aureus
(
S. aureus
) and
Escherichia coli
(
E. coli
). At the same time, composite coatings showed higher cell compatibility to MC3T3-E1 cells. Composite coatings promoted the expression of alkaline phosphatase (ALP) and upregulated the expression level of related osteogenic genes. Overall, these results are conducive to the advancement of the clinical application of magnesium alloys as orthopedic restorative materials.
Graphical abstract
•A liquid crystal (LC) microdroplet-based pH sensor was developed by doping 5CB with PBA.•The WGM spectrum from the PBA-doped 5CB microdroplet responded to pH variations by a spectral redshift as pH ...decreased.•The pH-sensitive LC microdroplet was firstly exploited to monitor the enzymatic reactions in penicillinase.
We report a liquid crystal (LC) microdroplet-based pH sensor and explore its application for detecting enzymatic reactions in penicillinase. Nematic LC 4-cyano-4'-pentylbiphenyl (5CB) microdroplet, doped with 4'-pentyl-biphenyl-4-carboxylic acid (PBA), is produced in phosphate buffer solution (PBS) with a tapered capillary microtube connected to a syringe pump. The PBA-doped 5CB microdroplets exhibit configuration transitions from bipolar to radial as PBS pH values increase from 5.7 to 6.0. These pH-induced changes in optical appearance are experimentally verified and attributed to the deprotonation of PBA at the aqueous/LC interface. We also examine the feasibility of the PBA-doped 5CB microdroplets as optical microcavities of whispering gallery modes (WGMs). Typical WGM lasing emission is observed in micrometer-sized microdroplets under a pulse laser pump. The WGM spectrum from the microdroplet responds to pH variations, reflecting as a spectral redshift as the pH decreases. The PBA-doped 5CB microdroplet can be successfully exploited accordingly for detecting enzymatic reactions in penicillinase. We demonstrate that the detectable shifts in WGM spectra associated with the microdroplet configuration transitions can serve as an indicator of the H+ released from the enzymatic reaction.
We demonstrate efficient coupling to the optical whispering gallery modes (WGMs) of nematic liquid crystal (NLC) microdroplets immersed in an immiscible aqueous environment. An individual NLC ...microdroplet, confined at the tip of a microcapillary, was coupled via a tapered optical fiber waveguide positioned correctly within its vicinity. Critical coupling of the taper-microdroplet system was facilitated by adjusting the gap between the taper and the microdroplet to change the overlap of the evanescent electromagnetic fields; efficient and controlled power transfer from the taper waveguide to the NLC microdroplet is indeed possible via the proposed technique. We also found that NLC microdroplets can function as highly sensitive thermal sensors: A maximum temperature sensitivity of 267.6 pm/°C and resolution of 7.5 × 10
°C were achieved in a 78-μm-diameter NLC microdroplet.
Microseismic signals contain various information for oil and gas developing. Increasing the signal-to-noise ratio of microseismic signals can successfully improve the effectiveness of oil and gas ...resource exploration. The lack of sufficient labeled microseismic signals makes it difficult to train neural network model. Transfer learning can solve this problem using image data sets to pre-train the denoising model and the learned knowledge can be transferred into microseismic signals denoising. In addition, a convolutional neural network (CNN) model with 16 layers is designed for noise reduction. Considering the strong similarity between noisy signals and denoising signals, residual learning is utilized to optimize the denoising model. The simulation experiment results show that the proposed denoising model eliminates the noise in the microseismic signals effectively and quickly, restores the amplitude of the microseismic signals with high accuracy, and has excellent effect in denoising on the information at the edge.
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