Effects of Ionic Interferents on Electrocatalytic Nitrate Reduction: Mechanistic Insight.

Nitrate, a prevalent water pollutant, poses substantial public health concerns and environmental risks. Electrochemical reduction of nitrate (eNO3RR) has emerged as an effective alternative to conventional biological treatments. While extensive lab work has focused on designing efficient electrocatalysts, implementation of eNO3RR in practical wastewater settings requires careful consideration of the effects of various constituents in real wastewater. In this critical review, we examine the interference of ionic species commonly encountered in electrocatalytic systems and universally present in wastewater, such as halogen ions, alkali metal cations, and other divalent/trivalent ions (Ca2+, Mg2+, HCO3-/CO32-, SO42-, and PO43-). Notably, we categorize and discuss the interfering mechanisms into four groups: (1) loss of active catalytic sites caused by competitive adsorption and precipitation, (2) electrostatic interactions in the electric double layer (EDL), including ion pairs and the shielding effect, (3) effects on the selectivity of N intermediates and final products (N2 or NH3), and (4) complications by the hydrogen evolution reaction (HER) and localized pH on the cathode surface. Finally, we summarize the competition among different mechanisms and propose future directions for a deeper mechanistic understanding of ionic impacts on eNO3RR.

Identification of genes involved in the four stages of colorectal cancer: Gene expression profiling.

BACKGROUND: Colorectal cancer (CRC) is a common cancer with high morbidity and mortality. However, its molecular mechanism is not clear, nor the genes related to CRC stages. METHODS: Gene expression data in CRC and healthy colorectal tissues were obtained from gene expression omnibus. Limma package was used to identify the differentially expressed genes (DEGs) between control and CRC (stage I, II, III, and IV), obtaining 4 DEG sets. VennPlex was utilized to find all DEGs and intersection DEGs. Functional interactions between all DEGs and protein-protein interactions (PPIs) between intersection DEGs were analyzed using ReactomeFIViz and STRING, respectively, and networks were visualized. Known CRC-related genes were down-loaded from Comparative Toxicogenomics Database and mapped to PPI network. RESULTS: Totally, 851, 760, 729, and 878 DEGs were found between control and CRC stage I, II, III, and IV, respectively. Taken together, 1235 DEGs were found, as well as 128 up-regulated intersection DEGs, 365 down-regulated intersection DEGs, and 0 contra-regulated DEG. A functional interaction network of all DEGs and a PPI network of intersection DEGs were constructed, in which CDC20, PTTG1, and MAD2L1 interacted with BUB1B; UGT2B17 interacted with ADH1B; MCM7 interacted with MCM2. BUB1B, ADH1B, and MCM2 were known CRC-related genes. Gradually upregulated expressions of CDC20, PTTG1, MAD2L1, UGT2B17, and MCM7 in stage I, II, III, and IV CRC were confirmed by using quantitative PCR. Besides, up-regulated intersection DEGs enriched in pathways about Cell cycle, DNA replication, and p53 signaling. CONCLUSION: CDC20, PTTG1, MAD2L1, UGT2B17, and MCM7 might be CRC stage-related genes.

Prenylated flavonoid fractions from Glycyrrhiza glabra alleviate insulin resistance in HepG2 cells by regulating the ERK/IRS-1 and PI3K/Akt signaling pathways.

Insulin resistance (IR) is a key factor in the pathogenesis of disrupted glucose metabolism. Although the extract of Glycyrrhiza glabra has shown significant hypoglycemic activity, its bioactive components remain to be identified, and their mechanisms of action, especially on hepatocyte glucose metabolism, are yet to be explored. In the present study, the primary compounds from Glycyrrhiza glabra [named prenylated flavonoid fractions (PFFs)] have been identified and their chemical structures have been elucidated. The therapeutic effects of PFFs extracted from G. glabra on glucose metabolism disorders and IR in high insulin-induced insulin-resistant HepG2 (IR-HepG2) cells have been determined. Glabridin (GLD) was used as a control. The results indicated that, similar to GLD, PFFs increased glucose consumption, glucose uptake, and translocation of glucose transporter 4 to the plasma membrane in IR-HepG2 cells. In addition, they enhanced the activities of glycogen synthase, glucokinase, and pyruvate kinase, while reducing the activities of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. Furthermore, they activated the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway and suppressed the extracellular signal-regulated kinase/insulin receptor substrate-1 (ERK/IRS-1) pathway. These findings suggest that, similar to GLD, PFFs can alleviate impaired glucose metabolism and alleviate IR in IR-HepG2 cells.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.The authors and their affiliations have been confirmed as correct.

[Detection of tobacco mosaic virus (TMV) in Rehmannia glutinosa f. hueichingensis by IC-RT-PCR].

OBJECTIVE: To establish a rapid, sensitive and efficient detection method for tobacco mosaic virus (TMV), and provide technical support of TMV detection of Rehmannia glutinosa f. hueichingensis. The virus-free plantlets could be produced on a large scale to ameliorate breed degeneration caused by viral disease. METHOD: Specific primers were designed based on the conserved region of coat protein(CP) gene of TMV. Immunocapture RT-PCR (IC-RT-PCR) was employed to detect TMV and the sequence of the products was detected. RESULT: The expected nucleotide acid fragments were amplified by IC-RT-PCR. The homology of nucleotide acid sequence and amino acid sequence were 95.29% and 96.7% between the PCR products and the CP gene of TMV (accession number AY555269). CONCLUSION: The method was established for the detection of TMV in R. glutinosa f. hueichingensis by IC-RT-PCR. This detection combined molecular biology technology with immunology, was convenient for a quick, sensitive and simple detection of TMV.

A smartphone-assisted paper-based ratio fluorescent probe for the rapid and on-site detection of tetracycline in food samples.

Rapid, sensitive and portable analytical methods for on-site detection of tetracycline (TC) in food samples is of critical importance for food safety and public health. In this study, a dual-emission ratio fluorescent probe (Gd0.9@Eu0.1) was prepared and utilized for the detection of tetracycline (TC) by observing the fluorescence color change from blue to red. The detection process exhibits a wide linear range (0-52.0 µM), good selectivity and low detection limit (14 nM). A paper-based probe and a colorimetric card was constructed for the visual detection of TC. Furthermore, a novel and portable detection platform combining smartphone and test strip was exploited for the quantitative and on-site detection of TC in real pork sample. The developed method was validated through intra- (n = 5) and inter-day (n = 2) measurements, as well as comparison with a traditional HPLC method. These statistical result validate the reliability and accuracy of the developed method. This intelligent detection platform represents a promising approach for the rapid, sensitive and visual detection of TC in food samples.

An intelligent smartphone-test strip detection platform for rapid and on-site sensing of benzoyl peroxide in flour samples.

Benzoyl peroxide (BPO) is a commonly used flour whitener, but its excessive usage can have adverse effects on human health, such as nutrient loss, vitamin deficiencies and certain diseases. In this study, a europium metal organic framework (Eu-MOF) fluorescence probe was prepared, which exhibited a strong fluorescence emission at 614 nm upon excitation at 320 nm, with a high quantum yield of 8.11%. The red fluorescence of the probe could be effectively quenched by BPO through the inner filter effect (IFE) and photoinduced electron transfer (PET) mechanism. The detection process offered several advantages, including a wide linear range of 0-0.95 mM, a low detection limit of 66 nM and a fast fluorescence response of 2 min. Furthermore, an intelligent detection platform was designed to enhance the practical application of the detection method. This platform combined the portability and visuality of a traditional test strip with the color recognition capability of a smartphone, allowing for the visualization and quantitative detection of BPO in a convenient and user-friendly manner. The detection platform was successfully applied to the analysis of BPO in real flour samples with satisfactory recoveries (99.79%-103.94%), suggesting a promising strategy for the rapid and on-site detection of BPO in food samples.

Preparation of reversible cross-linked amphiphilic polymeric micelles with pH-responsive behavior for smart drug delivery.

A new type of reversible cross-linked and pH-responsive polymeric micelle (PM), poly[polyethylene glycol methacrylate-co-2-(acetoacetoxy)ethyl methacrylate]-b-poly [2-(dimethylamino)ethyl methacrylate] [P(PEGMA-co-AEMA)-b-PDMAEMA], was synthesized for targeted delivery of curcumin. After reversible cross-linking of the micellar shell, the PMs with a typical core-shell structure exhibited excellent stability against extensive dilution and good reversibility of pH-responsiveness in solutions with different pH values. P(PEGMA9-co-AEMA6)-b-PDMAEMA10 has the lowest critical micelle concentration (CMC) value (0.0041 mg mL-1), the highest loading capacity (13.86%) and entrapment efficiency (97.03%). A slow sustained drug release at pH 7.4 with 12.36% in 108 h, while a fast release (42.36%) was observed at pH 5.0. Furthermore, a dissipative particle dynamics (DPD) simulation method was employed to investigate the self-assembly process and pH-responsive behavior of PMs. The optimal drug-carrier ratio (2%) and fraction of water (92%) were confirmed by analyzing the drug distribution and morphology of micelles during the self-assembly process of the block copolymer. The simulation results were consistent with experimental results, indicating DPD simulation shows potential to study the structure properties of reversible cross-linked micelles. The present findings provide a new method for the development of SDDS with good structural stability and controlled drug release properties.

[Study on proteomics of Hela cell apoptosis in bufalin-induced human cervical carcinoma].

OBJECTIVE: To seek possible effect targets of bufalin in HeLa cells by studying the impact of bufalin on cell protein expression profile after treatment on human cervical carcinoma cell lines HeLa. METHOD: Bufalin's ICs0was measured by MTr assay. The apoptosis of cells was observed by FCM (flow cytometry) and Hoechst 33342 staining assay. Differentiated expression protein spots were founded and identified using proteomic techniques, which could induce HeLa cell apoptosis. RESULT: Bufalin showed remarkable cytotoxic effect on HeLa cells. IC50 (154 +/- 21.5) nmol X L(-1) indicated the possibility of inducing cell apoptosis. The protein expression profile showed 11 differentiated expression protein spots. Among the 11 proteins, nudix-type motif 5, vimentin, hnRNP C1/hnRNP C2 variant, HNRPK, HNRPK isoform a variant (two spots are the same protein), heat shock protein 27, macrophage-capping protein, SELENBP1 protein were down-regulated, while ribosomal protein, large, P0 and S-adenosylmethionine synthetase 2 were up-regulated by bufalin treatment. They may be effect targets of bufalin in HeLa cells. Western blotting showed consistent results in heat shock protein 27, vimentin and HNRPK between expression after treatment with bufalin and two-dimensional electrophoresis. CONCLUSION: Bufa-Lin can induce apoptosis in human cervical carcinoma cells HeLa and the effect of bufalin may be related to the joint intervention with multiple protein targets.

Entrepreneurial Mentality Analysis for College Students Based on the Improved BP Neural Network.

In this study, the fuzzy comprehensive evaluation model is used to evaluate the characteristics of college students' entrepreneurial psychology, and a prediction model of college students' entrepreneurial psychology characteristics is established, which is simulated by Matlab to achieve good validity. Based on the research on the characteristics of college students' entrepreneurial psychology, this study proposes a design method of indicators and parameters for evaluating the characteristics of college students' entrepreneurial psychology. In this study, the genetic algorithm is used to optimize the BP neural network. The optimized neural network greatly improves the global search and local search capabilities. The performance of the model is tested through simulation tests. Through the simulation comparison test between the improved model and the standard model, the results show that the model can predict the entrepreneurial psychological characteristics of college students. By comparing the improved BP neural network algorithm with the original algorithm simulation experiment, the improved BP neural network improves the sensitivity by 20%, the specificity by 5%, and the accuracy by 8%.

Emotion Analysis of Ideological and Political Education Using a GRU Deep Neural Network.

Theoretical research into the emotional attributes of ideological and political education can improve our ability to understand human emotion and solve socio-emotional problems. To that end, this study undertook an analysis of emotion in ideological and political education by integrating a gate recurrent unit (GRU) with an attention mechanism. Based on the good results achieved by BERT in the downstream network, we use the long focusing attention mechanism assisted by two-way GRU to extract relevant information and global information of ideological and political education and emotion analysis, respectively. The two kinds of information complement each other, and the accuracy of emotion information can be further improved by combining neural network model. Finally, the validity and domain adaptability of the model were verified using several publicly available, fine-grained emotion datasets.

Screening and identification of a novel antidiabetic peptide from collagen hydrolysates of Chinese giant salamander skin: network pharmacology, inhibition kinetics and protection of IR-HepG2 cells.

In this study, a novel peptide GPPGPA was screened from the collagen hydrolysates of Chinese giant salamander (Andrias davidianus) skin, and its anti-diabetes mechanism was predicted by network pharmacology, and an inhibitory effect on α-glycosidase and protective effect on IR (insulin resistance) and oxidative stress of IR-HepG2 cells were detected. Through network pharmacology screening, GPPGPA was found to have good drug-like properties, and 103 targets of GPPGPA overlap with T2DM targets. These targets were mainly enriched in the PI3K-Akt signaling pathway associated with T2DM, the AGE-RAGE signaling pathway in diabetic complications, the TNF signaling pathway, insulin resistance and so on. The core targets were identified as AKT1, MAPK8, MAPK10 and JUN by constructing a "peptide-target-pathway" network. The molecular docking results showed that GPPGPA was well bound to the core targets. These results suggested that GPPGPA had the potential to reduce T2DM. Further in vitro experiments showed that GPPGPA as a competitive inhibitor could effectively inhibit the activity of α-glucosidase. The results of the IR-HepG2 cell model experiments showed that GPPGPA was not toxic to HepG2 cells, and could reduce IR of HepG2 cells induced by high-glucose and high-insulin, improve glucose consumption, increase the activity of superoxide dismutase (SOD), and reduce the content of malondialdehyde (MDA). The above results suggested that GPPGPA could improve T2DM by reducing insulin resistance through a multi-target and multi-pathway mechanism. GPPGPA could be developed and utilized as a novel hyperglycemic inhibitor in functional food.

Interaction mechanism of aloe-emodin with trypsin: molecular structure-affinity relationship and effect on biological activities.

The molecular mechanism of interaction between aloe-emodin (AE) and trypsin was investigated, exhibiting remarkable outcomes. To detect the interaction mechanism, the binding of AE with trypsin was examined by a multi-spectroscopy and molecular docking method. Results showed that the binding of AE and trypsin would lead to static quenching and their binding forces were van der Waals forces and hydrogen bonding. The results of simultaneous and three-dimensional fluorescence spectroscopy showed that the combination of AE and trypsin caused changes in the microenvironment around the trypsin fluorophore, which might change the spatial structure of trypsin. FT-IR spectroscopy showed that the contents of α-helix and ß-turn in trypsin were decreased and the contents of ß-sheet, random coil and antiparallel ß-sheet were increased. Moreover, all these experimental results were verified and reasonably explained by molecular docking results. We also investigated the enzyme activity of trypsin and the antioxidant activity of AE. The results showed that both the enzyme activity of trypsin and the antioxidant activity of AE were decreased after interaction between AE and trypsin. The findings outlined in this study should elucidate the molecular mechanisms of interaction between AE and trypsin and contribute to making full use of AE in the food industry.

Molecular mechanism of the interaction between resveratrol and trypsin via spectroscopy and molecular docking.

The molecular mechanism of the interaction between resveratrol and trypsin was studied using fluorescence spectroscopy (intrinsic fluorescence, synchronous fluorescence, three-dimensional fluorescence), ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and the molecular docking method, as well as through enzyme activity and antioxidant assay. The fluorescence experiments (the Stern-Volmer quenching constants (KSV)) indicated that resveratrol quenched the intrinsic fluorescence of trypsin through the static quenching mechanism. The number of binding sites was about one. The thermodynamic functions ΔG < 0 and ΔH > 0, ΔS > 0 of the binding process, indicating that the combination of the resveratrol and trypsin processes was a spontaneous exothermic reaction and that the hydrophobic effect was the main force between them. UV-vis spectra, synchronous fluorescence spectra and three-dimensional fluorescence spectra analysis showed that the combination of resveratrol and trypsin induced changes in the microenvironment around the fluorophores of trypsin, resulting in alterations in the spatial structure of trypsin. FT-IR spectroscopy indicated that the contents of the α-helixes and ß-turns in trypsin decreased and that the contents of the ß-sheets, random coils and antiparallel ß-sheets increased. All these experimental results were verified and reasonably explained by the molecular docking results. Upon resveratrol and trypsin binding, the enzyme catalytic activity of trypsin and the antioxidant of resveratrol decreased. Results from this study would be useful in elucidating the molecular mechanisms of the interactions between resveratrol and trypsin and contribute to making full use of resveratrol in the food industry.

Characterization and macrophage immunomodulatory activity of two polysaccharides from the flowers of Paeonia suffruticosa Andr.

Paeonia suffruticosa Andr. has a long history of cultivation in China and its flower possesses high nutritional and medicinal value. Characterization and macrophage immunomodulatory activity of the two polysaccharides from the flowers of Paeonia suffruticosa Andr., PSAP-1 and PSAP-2, purified by anion exchange chromatography followed by size exclusion chromatography, were investigated in the present study. Results showed that PSAP-1, with a molecular weight of 155 kDa, was mainly composed of glucuronic acid, glucose, arabinose and galactose with molar percentages of 0.83, 11.53, 18.98 and 68.96% respectively, and PSAP-2, with a molecular weight of 210 kDa, consisted of rhamnose, galacturonic acid, glucose, arabinose and galactose with molar percentages of 9.13, 8.35, 12.20, 14.75 and 55.57% respectively. Immunostimulatory activity evaluation in vitro revealed that the PSAP-1 and PSAP-2 could significantly stimulate the proliferation of Raw264.7 cells in dose-dependent manner and further activate Raw264.7 cells by releasing immunoactive molecules such as nitric oxide, tumor necrosis factor (TNF)-α and interleukin (IL)-6. In addition, PSAP-2 had higher immunomodulatory activity than PSAP-1. The above results suggested that both PSAP-1 and PSAP-2 had potent immunostimulatory activity and could be explored as a potential natural immunomodulatory agent in medicine or functional food fields.

Effects of low molecular sugars on the retrogradation of tapioca starch gels during storage.

The effects of low molecular sugars (sucrose, glucose and trehalose) on the retrogradation of tapioca starch (TS) gels stored at 4°C for different periods were examined with different methods. Decrease in melting enthalpy (ΔHmelt) were obtained through differential scanning calorimetry analysis. Analysis of decrease in crystallization rate constant (k) and increase in semi-crystallization time (τ1/2) results obtained from retrogradation kinetics indicated that low molecular sugars could retard the retrogradation of TS gels and further revealed trehalose as the best inhibitor among the sugars used in this study. Fourier transform infrared (FTIR) analysis indicated that the intensity ratio of 1047 to 1022 cm-1 was increased with the addition of sugars in the order of trehalose > sucrose > glucose. Decrease in hardness parameters and increase in springiness parameters obtained from texture profile analysis (TPA) analysis also indicated that low molecular sugars could retard the retrogradation of TS gels. The results of FTIR and TPA showed a consistent sugar effect on starch retrogradation with those of DSC and retrogradation kinetics analysis.

Evaluation of the sedative and hypnotic effects of Eucommiol in Eucommia.

The purpose of this study was to evaluate the sedative and hypnotic effects of Eucommiol, a monomer compound extracted from male Eucommia flowers using a system solvent method. Eucommiol shows significant effects in mice, including reduced spontaneous activity, and increased the sleep ratio or lengthened the sleep time with a subthreshold or superthreshold dose of pentobarbital sodium, respectively. In addition, could effectively shorten sleep latency, reduce convulsion rate and prolong convulsion latency. These findings intensely indicated that Eucommiol has excellent sedative and hypnotic effects.

MRT letter: localization of endogenous hydrogen peroxide by modified processes of sample preparation for transmission electron microscope in Escherichia coli.

The bacterial endogenous hydrogen peroxide (H(2)O(2)) was detected cytochemically by its reaction with cerium chloride (CeCl(3)) to produce electron-dense deposits of cerium perhydroxides. The sequence of fixation and CeCl(3) staining of H(2)O(2) in the processing of transmission electron microscope (TEM) sample preparation is crucial to the localization of endogenous H(2)O(2) in Escherichia coli. In this study, results confirmed that the process that fixation simultaneously with CeCl(3) staining provided optimum effects for H(2)O(2) localization in E. coli. The modified process of TEM provides very efficient protection for H(2)O(2) localization and more accurate quantization for the H(2)O(2) accumulation in bacterial cells.

[Expression, purification of proteasome subunit PSMB1 and application in screening of possible proteasome inhibitors].

Proteasome is a multi-subunit protease complex in eukaryocytes, and plays an important role in ubiquitin-proteosome pathway. Recombinant proteasome can be used to screen proteasome inhibitors. In this study, recombinant plasmid of pET28a-PSMB1 was constructed by inserting human proteasome catalytic subunit (PSMB1) cDNA (726 bp) into the prokaryotic expression vector pET28a(+), and transforming the plasmid into E. coli BL21(DE3) cells for expression. After overnight induction (1 mmol/L IPTG, 20 degrees C), an expected protein band with molecular weight of 27 kDa was observed on SDS-PAGE gel. The recombinant protein was then purified through affinity chromatography, and the purity is more than 95%. The amino acid sequence of the recombinant protein was validated by NanoLC-MS/MS. The data from in vitro BIAcore analysis showed that the recombinant PSMB1 could bind to celastrol. The binding affinity between PSMB1 and 10 micromol/L celastrol was more than 27RU.

Identification of a novel centrosomal protein CrpF46 involved in cell cycle progression and mitosis.

A novel centrosome-related protein CrpF46 was detected using a serum F46 from a patient suffering from progressive systemic sclerosis. We identified the protein by immunoprecipitation and Western blotting followed by tandem mass spectrometry sequencing. The protein CrpF46 has an apparent molecular mass of ~60 kDa, is highly homologous to a 527 amino acid sequence of the C-terminal portion of the protein Golgin-245, and appears to be a splice variant of Golgin-245. Immunofluorescence microscopy of synchronized HeLa cells labeled with an anti-CrpF46 monoclonal antibody revealed that CrpF46 localized exclusively to the centrosome during interphase, although it dispersed throughout the cytoplasm at the onset of mitosis. Domain analysis using CrpF46 fragments in GFP-expression vectors transformed into HeLa cells revealed that centrosomal targeting is conferred by a C-terminal coiled-coil domain. Antisense CrpF46 knockdown inhibited cell growth and proliferation and the cell cycle typically stalled at S phase. The knockdown also resulted in the formation of poly-centrosomal and multinucleate cells, which finally became apoptotic. These results suggest that CrpF46 is a novel centrosome-related protein that associates with the centrosome in a cell cycle-dependent manner and is involved in the progression of the cell cycle and M phase mechanism.