Pesticides directly pollute the environment and contaminate foods ultimately being absorbed by the human body. Their residues contain highly toxic substances that have been found to cause serious ...problems to human health even at very low concentrations. The gold standard method, gas/liquid chromatography combined with mass spectroscopy, has been widely used for the detection of pesticide residues. However, these methods have some drawbacks such as complicated pretreatment and cleanup steps. Recent technological advancements of surface-enhanced Raman spectroscopy (SERS) have promoted the creation of alternative detection techniques. SERS is a useful detection tool with ultrasensitivity and simpler protocols. Present SERS-based pesticide residue detection often uses standard solutions of target analytes in conjunction with theoretical Raman spectra calculated by density functional theory (DFT) and actual Raman spectra detected by SERS. SERS is quite a promising technique for the direct detection of pesticides at trace levels in liquid samples or on the surface of solid samples following simple extraction to increase the concentration of analytes. In this review, we highlight recent studies on SERS-based pesticide detection, including SERS for pesticide standard solution detection and for pesticides in/on food samples. Moreover, in-depth analysis of pesticide chemical structures, structural alteration during food processing, interaction with SERS substrates, and selection of SERS-active substrates is involved.
Background
Emerging studies have shown that HOTAIR acts as an oncogene in gastric cancer (GC). However, its role in the extracellular matrix and in tumor immune infiltration remains unknown.
Methods
...HOTAIR and COL5A1 levels were analyzed by bioinformatics analysis and validated by qRT-PCR, western blotting and immunohistochemistry assays. The regulatory relationships between components of the HOTAIR/miR-1277-5p/COL5A1 axis and the role of this axis in GC were predicted by bioinformatics analysis, and validated by in vitro and in vivo experiments. The correlation between COL5A1 and GC immune infiltration was assessed by bioinformatics analysis and a COL5A1-based predictive nomogram was established using the Stomach Adenocarcinoma dataset from The Cancer Genome Atlas.
Results
We found that HOTAIR and COL5A1 were overexpressed in GC compared to normal controls, which predicted poor prognosis. The regulatory relationship of the HOTAIR/miR-1277-5p/COL5A1 axis in GC was demonstrated, and HOTAIR and COL5A1 were found to promote GC growth while miR-1277-5p exerted the reverse effects. In addition, COL5A1 was negatively associated with tumor purity but positively associated with immune infiltration, which suggested that COL5A1-mediated GC growth may be partially mediated by the regulation of immune infiltration. Additionally, the established COL5A1-based nomogram showed that COL5A1 can serve as a prognostic biomarker in GC.
Conclusions
HOTAIR regulates GC growth by sponging miR-1277-5p and upregulating COL5A1, and COL5A1-mediated GC cell proliferation may be mediated by effects on the tumor microenvironment, which provides novel targets for GC treatment.
Melatonin (N‐acetyl‐5‐methoxytryptamine) plays important roles in plant defences against a variety of biotic and abiotic stresses, including UV‐B stress. Molecular mechanisms underlying functions of ...melatonin in plant UV‐B responses are poorly understood. Here, we show that melatonin effect on molecular signalling pathways, physiological changes and UV‐B stress resistance in Arabidopsis. Both exogenous and endogenous melatonin affected expression of UV‐B signal transduction pathway genes. Experiments using UV‐B signalling component mutants cop1‐4 and hy5‐215 revealed that melatonin not only acts as an antioxidant to promote UV‐B stress resistance, but also regulates expression of several key components of UV‐B signalling pathway, including ubiquitin‐degrading enzyme (COP1), transcription factors (HY5, HYH) and RUP1/2. Our findings indicate that melatonin delays and subsequently enhances expression of COP1, HY5, HYH and RUP1/2, which act as central effectors in UV‐B signalling pathway, thus regulating their effects on antioxidant systems to protect the plant from UV‐B stress.
Several studies have demonstrated that melatonin plays a role in UV‐B responses, however, the molecular mechanism whereby melatonin affects the UV‐B pathway was not clear. This study examined the function of melatonin in molecular signaling pathways, physiological changes, and UV‐B stress resistance under UV‐B radiation in Arabidopsis. Exogenous melatonin treatment experiment indicated that melatonin could enhance the transcriptional level of genes on UV‐B signaling pathway and ameliorate ROS damage caused by UV‐B stress. This result was verified in SNAT overexpressing lines and knock‐down mutant.
The development of flexible thermistor epidermal electronics (FTEE) to satisfy high temperature resolution without strain induced signal distortion is of great significance but still challenging. ...Inspired by the nacre microstructure capable of restraining the stress concentration, we exemplify a versatile MXene-based thermistor elastomer sensor (TES) platform that significantly alleviates the strain interference by the biomimetic laminated strategy combining with the in-plane stress dissipation and nacre-mimetic hierarchical architecture, delivering competitive advantages of superior thermosensitivity (-1.32% °C
), outstanding temperature resolution (~0.3 °C), and unparalleled mechanical durability (20000 folding fatigue cycles), together with considerable improvement in strain-tolerant thermosensation over commercial thermocouple in exercise scenario. By a combination of theoretical model simulation, microstructure observation, and superposed signal detection, the authors further reveal the underlying temperature and strain signal decoupling mechanism that substantiate the generality and customizability of the nacre-mimetic strategy, possessing insightful significance of fabricating FTEE for static and dynamic temperature detection.
Lipid peroxidation (LP) leads to changes in the fluidity and permeability of cell membranes, affecting normal cellular function and potentially triggering apoptosis or necrosis. This process is ...closely correlated with the onset of many diseases. Evidence suggests that the phenolic hydroxyl groups in food-borne plant polyphenols (FPPs) make them effective antioxidants capable of preventing diseases triggered by cell membrane LP. Proper dietary intake of FPPs can attenuate cellular oxidative stress, especially damage to cell membrane phospholipids, by activating the Nrf2/GPx4 pathway. Nuclear factor E2-related factor 2 (Nrf2) is an oxidative stress antagonist. The signaling pathway regulated by Nrf2 is a defense transduction pathway of the organism against external stimuli such as reactive oxygen species and exogenous chemicals. Glutathione peroxidase 4 (GPx4), under the regulation of Nrf2, is the only enzyme that reduces cell membrane lipid peroxides with specificity, thus playing a pivotal role in regulating cellular ferroptosis and counteracting oxidative stress. This study explored the Nrf2/GPx4 pathway mechanism, antioxidant activity of FPPs, and mechanism of LP. It also highlighted the bioprotective properties of FPPs against LP and its associated mechanisms, including (i) activation of the Nrf2/GPx4 pathway, with GPx4 potentially serving as a central target protein, (ii) regulation of antioxidant enzyme activities, leading to a reduction in the production of ROS and other peroxides, and (iii) antioxidant effects on LP and downstream phospholipid structure. In conclusion, FPPs play a crucial role as natural antioxidants in preventing LP. However, further in-depth analysis of FPPs coregulation of multiple signaling pathways is required, and the combined effects of these mechanisms need further evaluation in experimental models. Human trials could provide valuable insights into new directions for research and application.
Background
Gastric cancer (GC) is common in East Asia, yet its molecular and pathogenic mechanisms remain unclear. Circular RNAs (circRNAs) are differentially expressed in GC and may be promising ...biomarkers. Here, we investigated the role and regulatory mechanism of circTMC5 in GC.
Methods
CircTMC5 expression was detected in human GC and adjacent tissues using microarray assays and qRT-PCR, while the clinicopathological characteristics of patients with GC were used to assess its diagnostic and prognostic value. The circTMC5/miR-361-3p/RABL6 axis was examined in vitro and vivo, and the immune roles of RABL6 were evaluated using bioinformatics analyses and immunohistochemistry (IHC).
Results
CircTMC5 was highly expressed in GC tissues, plasma, and cell lines, and was closely related to histological grade, pathological stage, and T classification in patients with GC. CircTMC5 expression was also an independent prognostic factor for GC and its combined detection with carcinoembryonic antigen may improve GC diagnosis. Low circTMC5 expression correlated with good prognosis, inhibited GC cell proliferation, and promoted apoptosis. Mechanistically, circTMC5 overexpression promoted GC cell proliferation, invasion, and metastasis but inhibited apoptosis by sponging miR-361-3p and up-regulating RABL6 in vitro and vivo, whereas miR-361-3p up-regulation had the opposite effects. RABL6 was highly expressed in GC and was involved in immune regulation and infiltration in GC.
Conclusions
CircTMC5 promotes GC and sponges miR-361-3p to up-regulate RABL6 expression, thus may have diagnostic and prognostic value in GC. RABL6 also displays therapeutic promise due to its role in the immune regulation of GC.
Wide applications of personal consumer electronics have triggered tremendous need for portable power sources featuring light-weight and mechanical flexibility. Perovskite solar cells offer a ...compelling combination of low-cost and high device performance. Here we demonstrate high-performance planar heterojunction perovskite solar cells constructed on highly flexible and ultrathin silver-mesh/conducting polymer substrates. The device performance is comparable to that of their counterparts on rigid glass/indium tin oxide substrates, reaching a power conversion efficiency of 14.0%, while the specific power (the ratio of power to device weight) reaches 1.96 kW kg(-1), given the fact that the device is constructed on a 57-μm-thick polyethylene terephthalate based substrate. The flexible device also demonstrates excellent robustness against mechanical deformation, retaining >95% of its original efficiency after 5,000 times fully bending. Our results confirmed that perovskite thin films are fully compatible with our flexible substrates, and are thus promising for future applications in flexible and bendable solar cells.
Innovative application of surface-enhanced Raman scattering (SERS) for rapid and nondestructive analyses has been gaining increasing attention for food safety and quality. SERS is based on inelastic ...scattering enhancement from molecules located near nanostructured metallic surfaces and has many advantages, including ultrasensitive detection and simple protocols. Current SERS-based quality analysis contains composition and structural information that can be used to establish an electronic file of the food samples for subsequent reference and traceability. SERS is a promising technique for the detection of chemical, biological, and harmful metal contaminants, as well as for food poisoning, and allergen identification using label-free or label-based methods, based on metals and semiconductors as substrates. Recognition elements, including immunosensors, aptasensors, or molecularly imprinted polymers, can be linked to SERS tags to specifically identify targeted contaminants and perform authenticity analysis. Herein, we highlight recent studies on SERS-based quality and safety analysis for different foods categories spanning the whole food chain, ‘from farm to table’ and processing, genetically modified food, and novel foods. Moreover, SERS detection is a potential tool that ensures food safety in an easy, rapid, reliable, and nondestructive manner during the COVID-19 pandemic.
During the mining of coal seam groups, the physical and chemical properties of the residual coal in goaf will be changed after undergoing water leaching and air-drying, affecting the oxidation ...characteristics of the coal. To examine the effect of the water immersion and air-drying times on the oxidative combustion characteristics of long-flame coal, this paper uses thermal gravimetric (TG) analysis and infrared spectral analysis to analyze coal samples with different immersion and air-drying times. The change in activation energy (AE), which is associated with the change in the functional groups, was analyzed for the coal-oxygen chain reaction process under coal immersion and air-drying conditions. The results show that coal samples soaked in air-dried for 10 days after water for 20 days have a lower AE (39.14 kJ/mol) than coal samples that underwent other treatment times and have a higher oxygen absorption rate and a higher tendency to undergo spontaneous combustion. According to the TG-DSC test, a range of weight loss and exothermic strengths are observed during the longest immersion and air-drying times. Additionally, during the longest immersion and air-drying times, the variations in the different functional groups are more obvious, the aliphatic hydrocarbon chain breaks and the coal rank is lower. The period of immersion and air-drying can change the spontaneous combustion oxidation characteristics of coal. After being soaked in water for 20 days and air-dried for 10 days, the coal sample was looser and the chain reaction process was accelerated, which promoted the oxidation and spontaneous combustion of coal.
Insect protein extract is one of the high-quality protein sources and is frequently viewed as a potential nutrition alternative. However, a more precise method for protein measurement is still needed ...due to protein overestimation by the Kjeldahl method due to the presence of a large amount of chitin in insects. Therefore, we demonstrated the monitoring of chitin and protein extracted from yellow mealworm larvae through the information on molecular vibration obtained using Raman spectroscopy and infrared (IR) spectroscopy. The NH vibration at 3475 cm−1 is the characteristic peak of chitin in defatted product observed in the Raman spectra. The nitrogen-to-protein conversion factor in protein extracted from larvae by the Raman method was determined based on the NH vibration and found to be 5.66 ± 0.01. We also compared these experimental data to theoretical Raman and IR spectra and determined the possible reasons for why nitrogen elements in chitin affect the determination of protein content. The method of sequentially removing fat and protein could provide more accurate quantification of protein and chitin. Raman spectroscopy is feasible for various types of insects with high chitin content. Compared with the Kjeldahl method, the Raman method is a faster and more accurate measurement method. Moreover, it provides the content of impurities, purity, and structural information.
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