Search Results (11)

Microbial contamination is the leading cause of foodborne diseases and spoilage in food and personal care products. Previous studies by our group have demonstrated that vine tea extract (VTE) and dihydromyricetin (DMY) inhibit the growth of Escherichia coli. In this study, we further explored the inhibitory mechanisms of VTE and DMY against E. coli through a label-free proteomics approach. The proteomic analysis detected 130 and 81 differentially expressed proteins (DEPs) in E.coli following VTE and DMY treatment, respectively. The analysis indicated that VTE and DMY inhibit bacterial growth through multiple-target mechanisms. Specifically, they inhibit E. coli growth by disrupting the cationic antimicrobial peptide resistance pathway, amino acid biosynthesis and metabolism, and nucleotide metabolism. Additionally, VTE disrupts various secondary metabolic pathways, while DMY interferes with E. coli ribosome assembly and function, and disrupts cell membrane lipid homeostasis by interfering with fatty acid metabolism. RT-qPCR validation confirmed transcriptional alterations in genes encoding key target proteins. Molecular docking results indicated that DMY may affect bacterial protein synthesis, cationic antimicrobial peptide resistance, and transcriptional regulation by binding to target proteins such as RplB, RplV, LpxA, and YafC. In conclusion, this study systematically deciphered the multi-target inhibitory mechanisms of VTE and DMY against E. coli, providing a theoretical basis for developing plant-derived antimicrobial agents. Full article

DNA replication is a crucial biological process that ensures the accurate transmission of genetic information, underpinning the growth, development, and reproduction of organisms. Abnormalities in DNA replication are a primary source of genomic instability and tumorigenesis. During DNA replication, the assembly of the pre-RC at the G1-G1/S transition is a crucial licensing step that ensures the successful initiation of replication. Although many pre-replication complex (pre-RC) proteins have been identified, technical limitations hinder the detection of transiently interacting proteins. The APEX system employs peroxidase-mediated rapid labeling with high catalytic efficiency, enabling protein labeling within one minute and detection of transient protein interactions. MCM2 is a key component of the eukaryotic replication initiation complex, which is essential for DNA replication. In this study, we fused MCM2 with enhanced APEX2 to perform in situ biotinylation. By combining this approach with mass spectrometry, we identified proteins proximal to the replication initiation complex in synchronized mouse ESCs and NIH/3T3. Through a comparison of the results from both cell types, we identified some candidate proteins. Interactions between MCM2 and the candidate proteins CD2BP2, VRK1, and GTSE1 were confirmed by bimolecular fluorescence complementation. This research establishes a basis for further study of the component proteins of the conserved DNA replication initiation complex and the transient regulatory network involving its proximal proteins. Full article

Ionic liquids, which are widely recognized as environmentally friendly solvents, stand out as promising alternatives to traditional heat-transfer fluids due to their outstanding heat-storage and heat-transfer capabilities. In the course of our ongoing research, we successfully synthesized ionic liquids 1-ethyl-4-alkyl-1,2,4-triazolium alanine [Taz(2,n)][Ala], where (n = 4, 5); in this study, we present comprehensive data on their density, surface tension, isobaric molar heat capacity, and thermal conductivity for the first time. The key thermophysical parameters influencing the heat-transfer process, such as thermal expansibility, compressibility, isochoric heat capacity, and heat-storage density, were meticulously calculated from experimental data. Upon comparison with previously reported ionic liquids and commercially utilized heat-transfer fluids, [Taz(2,n)][Ala] demonstrated superior heat-storage and heat-transfer performance, particularly in terms of heat-storage density (~2.63 MJ·m⁻³·K⁻¹), thermal conductivity (~0.190 W·m⁻¹·K⁻¹), and melting temperature (~226 K). Additionally, the presence of the alanine anion in [Taz(2,n)][Ala] provides more possibilities for its functional application. Full article

Terahertz (THz) sensors have attracted great attention in the biological field due to their nondestructive and contact-free biochemical samples. Recently, the concept of a quasi-bound state in the continuum (QBIC) has gained significant attention in designing biosensors with ultrahigh sensitivity. QBIC-based metasurfaces (MSs) achieve excellent performance in various applications, including sensing, optical switching, and laser, providing a reliable platform for biomaterial sensors with terahertz radiation. In this study, a structure-engineered THz MS consisting of a “double C” array has been designed, in which an asymmetry parameter α is introduced into the structure by changing the length of one subunit; the Q-factor of the QBIC device can be optimized by engineering the asymmetry parameter α. Theoretical calculation with coupling equations can well reproduce the THz transmission spectra of the designed THz QBIC MS obtained from the numerical simulation. Experimentally, we adopt an MS with α = 0.44 for testing arginine molecules. The experimental results show that different concentrations of arginine molecules lead to significant transmission changes near QBIC resonant frequencies, and the amplitude change is shown to be 16 times higher than that of the classical dipole resonance. The direct limit of detection for arginine molecules on the QBIC MS reaches 0.36 ng/mL. This work provides a new way to realize rapid, accurate, and nondestructive sensing of trace molecules and has potential application in biomaterial detection. Full article

A high-sensitivity curvature sensor with dual-parameter measurement ability based on angularly cascaded long-period fiber grating (AC-LPFG) is proposed and experimentally demonstrated, which consists of two titled LPFGs (TLPFGs) with different tilt angles and the same grating period. AC-LPFG was fabricated by using a deep ultraviolet laser and an amplitude-mask in our laboratory. The experimental results show that simultaneous measurement of curvature and temperature can be achieved by monitoring the wavelengths of two resonant peaks for different TLPFGs. The two peaks show opposite shifts with increasing curvature and has a maximum curvature sensitivity of 16.392 nm/m⁻¹. With the advantages of low cost, high sensitivity, and dual-parameter measurements, our sensor has more potential for engineering applications. Full article

Terahertz (THz) metamaterial (MM) biosensors are a potential method of biomolecule detection. However, there have been few reports on the detection of trace proteins. In this study, we designed a novel THz biosensor consisting of graphene, polyimide (PI), and electromagnetically induced transparency-like (EIT-like) MMs for the ultra-sensitive detection of ovalbumin (OVA). The doping analyte can influence the Fermi level and electrical conductivity of graphene, as well as the coupling of resonators in MMs. These changes are reflected in the magnitude, phase, and frequency changes in the transmission spectra. The biosensor achieved a high sensitivity function for OVA and reached a limit of detection (LoD) of 8.63 pg/mL. The results showed that by regulating the Fermi level of graphene between the valence band, Dirac point, and conduction band, the sensitivity and LoD of MM-based THz biosensors can be enhanced. Such biosensors have the potential to be used in the high-sensitivity detection of trace proteins in biomedical fields. Full article

In this study, Hf_xAl_yO_z nanolaminate, single-layer Al₂O₃, and HfO₂ gate insulators were fabricated by atomic layer deposition (ALD) to successfully integrate the InGaZnO (IGZO) thin-film transistors (TFTs). Compared with single-layer HfO₂-based TFTs, the Hf_xAl_yO_z-based IGZO TFTs showed a larger field-effect mobility of 10.31 cm²/Vs and a smaller subthreshold swing of 0.12 V/decade. Moreover, it showed a smaller threshold voltage shift of 0.5 V than that of HfO₂-based TFTs under gate-bias stress at +5 V for 900 s due to the smooth surface. Moreover, the high dielectric Hf_xAl_yO_z nanolaminate had a larger equivalent SiO₂ thinness than that of Al₂O₃ gate insulators, which are beneficial in applications of high-resolution display. Thus, the high mobility and high stability TFTs could be regarded as good candidates for active-matrix flat panel displays. Full article

Quantitative accounting of greenhouse gas (GHG) emissions has become an important global focus. GHG emissions from the waste sector have high potential in GHG emissions reduction. We analyzed the GHG emissions inventory in the waste sector of the European Union, Germany, the United Kingdom, the United States of America, and Canada from 1990 to 2019. Landfill disposal was the main category of GHGs from the waste sector, with a contribution rate between 69% and 95%. Landfill disposal also played a prominent role in emission reduction, with a contribution rate higher than 86%. GHG emissions from landfill sites in China were calculated using the inventory analysis method recommended by the IPCC and combined with actual situations. The results showed that the highest GHG emissions from landfill disposal in China occurred in 2020, with an estimated 165 million tons of carbon dioxide (CO₂) equivalent. In 2019, the per capita GHG emissions from landfill sites in China was 117 kg CO₂ equivalent/person, which was higher than Germany (87 kg CO₂ equivalent/person) but lower than the European Union (189 kg CO₂ equivalent/person). Full article

Vegetation, a key intermediary linking water, the atmosphere, and the ground, performs extremely important functions in nature and for our existence. Although satellite-based remote-sensing technologies have become important for monitoring vegetation dynamics, selecting the correct remote-sensing vegetation indicator has become paramount for such investigations. This study investigated the consistencies between a photosynthetic activity index (the solar-induced chlorophyll fluorescence (SIF) indicator) and the traditional vegetation index (the Normalized Difference Vegetation Index (NDVI)) among different land-cover types and in different seasons and explored the applicability of NDVI and SIF in different cases by comparing their performances in gross primary production (GPP) and grain-yield-monitoring applications. The vegetation cover and photosynthesis showed decreasing trends, which were mainly concentrated in northern Xinjiang and part of the Qinghai–Tibet Plateau; a decreasing trend was also identified in a small part of Northeast China. The correlations between NDVI and SIF were strong for all land-cover types except evergreen needleleaf forests and evergreen broadleaf forests. Compared with NDVI, SIF had some advantages when monitoring the GPP and grain yields among different land-cover types. For example, SIF could capture the effects of drought on GPP and grain yields better than NDVI. To summarize, as the temporal extent of the available SIF data is extended, SIF will certainly perform increasingly wide applications in agricultural-management research that is closely related to GPP and grain-yield monitoring. Full article

Hyperspectral remote sensing images (HSIs) have great research and application value. At present, deep learning has become an important method for studying image processing. The Generative Adversarial Network (GAN) model is a typical network of deep learning developed in recent years and the GAN model can also be used to classify HSIs. However, there are still some problems in the classification of HSIs. On the one hand, due to the existence of different objects with the same spectrum phenomenon, if only according to the original GAN model to generate samples from spectral samples, it will produce the wrong detailed characteristic information. On the other hand, the gradient disappears in the original GAN model and the scoring ability of a single discriminator limits the quality of the generated samples. In order to solve the above problems, we introduce the scoring mechanism of multi-discriminator collaboration and complete semi-supervised classification on three hyperspectral data sets. Compared with the original GAN model with a single discriminator, the adjusted criterion is more rigorous and accurate and the generated samples can show more accurate characteristics. Aiming at the pattern collapse and diversity deficiency of the original GAN generated by single discriminator, this paper proposes a multi-discriminator generative adversarial networks (MDGANs) and studies the influence of the number of discriminators on the classification results. The experimental results show that the introduction of multi-discriminator improves the judgment ability of the model, ensures the effect of generating samples, solves the problem of noise in generating spectral samples and can improve the classification effect of HSIs. At the same time, the number of discriminators has different effects on different data sets. Full article