Three-dimensional DNA nanomachine biosensor coupled with CRISPR Cas12a cascade amplification for ultrasensitive detection of carcinoembryonic antigen.

The detection of carcinoembryonic antigen (CEA) holds significant importance in the early diagnosis of cancer. However, current methods are hindered by limited accessibility and specificity. This study proposes a rapid and convenient Cas12a-based assay for the direct detection of CEA in clinical serum samples, aiming to address these limitations. The protocol involves a rolling machine operation, followed by a 5-min Cas12a-mediated cleavage process. The assay demonstrates the capability to detect human serum with high anti-interference performance and a detection limit as low as 0.2 ng/mL. The entire testing procedure can be accomplished in 75 min without centrifugation steps, and successfully reduced the limit of detection of traditional DNA walking machine by 50 folds. Overall, the testing procedure can be easily implemented in clinical settings.

A Smartphone-Enabled Colorimetric Platform Based on Enzyme Cascade Amplification Strategy for Detection of Staphylococcus aureus in Milk.

Staphylococcus aureus (S. aureus) is a pathogenic bacterium-contaminating milk and dairy foods causing food poisoning and foodborne pathogens. In this work, a smartphone-enabled enzyme cascade-triggered colorimetric platform was constructed using cascade bio-nanozyme formed by immobilized glucose oxidase (GOx) on the Fe3O4@Ag for rapid detection of S. aureus. Benefiting from reasonable experimental design, a bio-nanozyme cascade-triggered reaction was achieved through H2O2 produced by GOx oxidation of glucose, followed by in situ catalysis of 3,3',5,5'-tetramethylbenzidine (TMB) by the inherent peroxidase-like activity of Fe3O4@Ag to produce color signals. S. aureus detection could be performed through naked-eye observation and smartphone measurement, the developed assay can achieve quantitative and qualitative detection of S. aureus. The on-site nanoplatform had satisfactory specificity and sensitivity with a low detection limit of 6.9 cfu·mL-1 in 50 min. Moreover, the nanoplatform has good practicality in the detection of S. aureus in milk samples. Therefore, the assay has potential application prospects in food safety inspection.

KRASG12C mutation-induced TOPK overexpression contributes to tumour progression in non-small cell lung cancer.

KRAS mutation is the most frequent type of genetic mutation in non-small cell lung cancer (NSCLC), especially in lung adenocarcinoma. However, KRAS mutation can affect many biological processes and the mechanisms underlying KRAS mutation-mediate carcinogenesis in NSCLC have not been fully understood. In this research, we found that KRASG12C mutation was associated with the upregulation of T-LAK cell-originated protein kinase (TOPK), which is a well-known serine/threonine MAPK-like protein kinase implicated in tumorigenesis. The overexpression of TOPK significantly promoted the malignant phenotype of A549 cells, and TOPK silencing impaired the malignant phenotype with KRASG12C mutation. Moreover, we demonstrated that TOPK level was regulated by MAPK/ERK signalling and the transcription factor Elk1. TOPK was also found to promote the activation of NF-κB signalling in A549 cells with KRASG12C mutation via facilitating the phosphorylation of TAK1. In the in vivo tumorigenesis model, the administration of TOPK inhibitor OTS514 enhanced the anticancer effect of 5-FU, and the combinatory use of OTS514 and KRASG12C inhibitor AMG510 showed synergistic anti-tumour effect. These results suggest that KRAS-TOPK axis contributes to the progression of NSCLC and targeting this axis could synergize with anticancer effect of the existing chemotherapeutics.

Loss of MBD2 ameliorates LPS-induced alveolar epithelial cell apoptosis and ALI in mice via modulating intracellular zinc homeostasis.

Apoptosis of alveolar epithelial cells is a critical initial link in the pathogenesis of acute lung injury (ALI), recent studies have revealed that Methyl-CpG binding domain protein 2 (MBD2) was involved in the execution of apoptosis, yet its role in ALI remained unclear. In the present study, we aim to explore the role and mechanism of MBD2 in the pathogenesis of ALI. We have found that MBD2 expression, in parallel to apoptosis, increased in alveolar epithelial cells of mice treated with LPS, knockout of MBD2 reduced apoptosis and protected mice from LPS-induced ALI. In MLE-12 cells, a cell line of murine alveolar epithelial cells, LPS induced MBD2 expression and apoptosis in a dose- and time-dependent manner. Knockdown of MBD2 with shRNA alleviated, while overexpression of MBD2 increased LPS-induced apoptosis. Mechanistically, intracellular zinc level decreased when MLE-12 cells were treated with LPS. MBD2 knockdown restored intracellular zinc level after LPS treatment, and MBD2 overexpression further aggravated LPS-induced intracellular zinc loss. Metal transcription factor 1 (MTF1) is a critical transcription factor in charge of intracellular zinc efflux. LPS treatment induced MTF1 expression both in vivo and in vitro. Inhibition of MTF1 reduced LPS-induced apoptosis in MLE-12 cells. MBD2 could bind to the promoter region of MTF1 and promote MTF1 expression. Collectively, these data indicated that loss of MBD2-ameliorated LPS-induced alveolar epithelial cell apoptosis and ALI in mice via modulating intracellular zinc homeostasis by upregulating MTF1.

Immobilization mechanism of cesium in geopolymer: Effects of alkaline activators and calcination temperature.

Geopolymer is always regarded as a promising material for the immobilization of radioactive waste. In the present study, the stabilization of Cs in geopolymers activated by NaOH and Na2SiO3 solutions and calcined at various temperatures was studied via toxicity characteristic leaching procedure (TCLP), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope and energy dispersive spectroscopy (SEM-EDS), solid-state nuclear magnetic resonance (SSNMR), and N2 adsorption-desorption isotherm. For both NaOH-activated and Na2SiO3-activated geopolymers, the leaching concentrations of Cs decreased with the increase of calcination temperature. Specifically, most of the amorphous substance was crystallized to nepheline at 1000 °C for NaOH-activated geopolymer, and Cs+ can be incorporated into the structure of nepheline, contributing to the reduction of Cs leaching concentration. However, the amorphous structure was still maintained for Na2SiO3-activated geopolymer even after calcination at 1000 °C. It has been deduced that the main structure of Na2SiO3-activated geopolymer after calcination at 1000 °C should be in short-range order and Cs+ can be locked in a micro "crystal" structure. In addition, the change of specific surface area was not fully consistent with the decreasing trend of Cs leaching concentration. Therefore, the inner structure and the specific surface area of geopolymer should have a combined effect on the leaching behavior of Cs. This study can provide new insights into the application of geopolymer to immobilize radionuclides.

Rapid qualitative and quantitative detection of Salmonella typhimurium using a single-step dual photometric/fluorometric assay.

A dual-signal photometric/fluorometric assay was established for rapid, qualitative, and quantitative detection of Salmonella typhimurium (S. typhimurium). This method was composed of two parts: (1) a single-step photometric (SSC) assay containing gold nanoparticles (AuNPs), poly-diallyldimethylammonium chloride (PDDA), and S. typhimurium-specific aptamer, and (2) a fluorescence (FL) assay containing carboxyl-modified CdSe/ZnS quantum dots (QDs-COOH). Users just need to drop samples contaminated with S. typhimurium into SSC assay; the apparent color change from red to blue can be observed in a short time (20 min). A smartphone app was developed to read the semiquantitative result. By subsequently adding one drop of FL assay into the reaction mixture, the generated fluorescence intensity reflected the concentration of S. typhimurium. The naked eye limit of detection (LOD) and fluorescent LOD were 103 cfu/mL and 10 cfu/mL, respectively. This method exhibited good selectivity. The reliability and practicability were verified by testing contaminated food, drinking water, and pets' urine.

Application of Geopolymer in Stabilization/Solidification of Hazardous Pollutants: A Review.

Geopolymers, as a kind of inorganic polymer, possess excellent properties and have been broadly studied for the stabilization/solidification (S/S) of hazardous pollutants. Even though many reviews about geopolymers have been published, the summary of geopolymer-based S/S for various contaminants has not been well conducted. Therefore, the S/S of hazardous pollutants using geopolymers are comprehensively summarized in this review. Geopolymer-based S/S of typical cations, including Pb, Zn, Cd, Cs, Cu, Sr, Ni, etc., were involved and elucidated. The S/S mechanisms for cationic heavy metals were concluded, mainly including physical encapsulation, sorption, precipitation, and bonding with a silicate structure. In addition, compared to cationic ions, geopolymers have a poor immobilization ability on anions due to the repulsive effect between them, presenting a high leaching percentage. However, some anions, such as Se or As oxyanions, have been proved to exist in geopolymers through electrostatic interaction, which provides a direction to enhance the geopolymer-based S/S for anions. Besides, few reports about geopolymer-based S/S of organic pollutants have been published. Furthermore, the adsorbents of geopolymer-based composites designed and studied for the removal of hazardous pollutants from aqueous conditions are also briefly discussed. On the whole, this review will offer insights into geopolymer-based S/S technology. Furthermore, the challenges to geopolymer-based S/S technology outlined in this work are expected to be of direct relevance to the focus of future research.

Ferulic acid alleviates alveolar epithelial barrier dysfunction in sepsis-induced acute lung injury by activating the Nrf2/HO-1 pathway and inhibiting ferroptosis.

CONTEXT: Ferulic acid (FA) has antioxidative and anti-inflammatory effects, and is a promising drug to treat sepsis. OBJECTIVE: To study the therapeutic effect of FA in sepsis-induced acute lung injury (ALI) and its underlying mechanisms. MATERIALS AND METHODS: The caecal ligation and puncture (CLP) manoeuvre was applied to establish a murine model of sepsis-induced ALI, and female BALB/c mice (6 mice per group) were subjected to 100 mg/kg FA or 0.8 mg/kg ferrostatin-1 (Fer-1, ferroptosis inhibitor) treatment to clarify the role of FA in preserving alveolar epithelial barrier function and inhibiting ferroptosis. Lipopolysaccharide (LPS; 500 ng/mL)-induced cell models were prepared and subjected to FA (0.1 µM), sh-Nrf2, and Fe (Fe-citrate, ferroptosis inducer; 5 M) treatment to study the in vitro effect of FA on LPS-induced alveolar epithelial cell injury and the role of the Nrf2/HO-1 pathway. RESULTS: We found that FA decreased the lung injury score (48% reduction), lung wet/dry weight ratio (33% reduction), and myeloperoxidase activity (58% reduction) in sepsis-induced ALI. Moreover, FA inhibited ferroptosis of alveolar epithelial cells and improved alveolar epithelial barrier dysfunction. The protective role of FA against alveolar epithelial barrier dysfunction could be reversed by the ferroptosis inducer Fe-citrate, suggesting that FA alleviates alveolar epithelial barrier dysfunction by inhibiting ferroptosis. Mechanistically, we found that FA inhibited ferroptosis of alveolar epithelial cells by activating the Nrf2/HO-1 pathway. CONCLUSION: Collectively, our data highlighted the alleviatory role of ferulic acid in sepsis-induced ALI by activating the Nrf2/HO-1 pathway and inhibiting ferroptosis, offering a new basis for sepsis treatment.

Multi-functional magnetic molecular imprinting probe for visual detection of IgY antibodies.

Egg yolk antibodies (IgY) are an alternative to mammalian antibodies, which have been successfully applied in treatment of disease, as immunochemical reagents and as food additives. A fast, accurate, and easy-to-operate detection method for IgY antibodies is needed. Herein, we developed a rapid and cost-effective colorimetric assay for the ultrasensitive detection of anti-S. aureus IgY antibodies using multi-functional magnetic molecularly imprinted polymers (MMIPs). The prepared MMIPs can recognize, adsorb, and separate the analyte from the matrix efficiently, and oxidize TMB to generate a colorimetric signal within ~ 60 min. As low as 0.013 mg·mL-1 was able to be detected by using this method. The visual detection limit reached 0.02 mg·mL-1. By testing the IgY in milk samples, the feasibility was verified.

Multi-functional MnO2-doped Fe3O4 nanoparticles as an artificial enzyme for the colorimetric detection of bacteria.

The authors describe a rapid enzyme-free colorimetric assay for food- and water-borne pathogens by using the multi-functional MnO2-doped magnetic ferrite nanoparticles (MCDs-MnO2 NPs). These nanoparticles not only can recognize, absorb, and separate the analyte from the matrix efficiently but also can directly catalyze the oxidation of TMB into a blue colored product without H2O2. In the presence of target, the nanoparticles preferentially bind to the target surface and the interaction between nanoparticles and TMB can be blocked, providing turn-off sensing of bacteria. By combining the superior capture efficiency of magnetic beads with the high catalytic activity of the enzyme mimic, the turn-off colorimetric assay can detect the gram-positive bacterium and the gram-negative bacterium by the naked eye at a low detection limit (102 cfu mL-1) with a wide line arrange from 10 to 106 cfu mL-1. With the advantage of simplicity, sensitivity, and specificity, this proposed approach showed promise in rapid instrumental and on-site visual detection of bacteria for determination of water contamination. Graphical abstract.

Colorimetric immunoassay for rapid detection of Staphylococcus aureus based on etching-enhanced peroxidase-like catalytic activity of gold nanoparticles.

A novel colorimetric immunoassay for the detection of Staphylococcus aureus (S. aureus) based on a combination of immunomagnetic separation and signal amplification via etching-enhanced peroxidase-like catalytic activity of gold nanoparticles (AuNPs) was developed. Nanoconjugates composed of gold and iron oxide nanoparticles were synthesized and further modified with antiS. aureus immunoglobulin Y (IgY), which was used for the selective enrichment and rapid separation of target bacteria in complex matrices. AuNPs functionalized with antiS. aureus aptamer were used as an artificial enzyme which has peroxidase-like catalysis activity. Catalytic activity of AuNPs is inhibited by modifying aptamer. However, catalysis of modified AuNPs remarkably enhanced by hydrogen peroxide etching. Based on collecting unbound modified AuNPs in the supernatant and 3,3',5,5'-tetramethylbenzidine-hydrogen peroxide reporting system, the yellow color of solution decreases linearly with increasing the concentration of S. aureus ranging from 10 to 106 cfu/mL. The limit of detection is 10 cfu/mL, and total detection time is 65 min. The recoveries of the S. aureus spiked in food samples are 88.2-119.8%. Schematic illustration of colorimetric method for detection of S. aureus based on the IgY-Fe3O4/Au nanocomposites as capture probes and apt-AuNPs as artificial enzyme with etching-enhanced peroxidase-like catalytic activity.

A novel visual-mixed-dye for LAMP and its application in the detection of foodborne pathogens.

Loop-mediated isothermal amplification (LAMP) has been widely applied for the detection of foodborne pathogens. Obtaining a simple, accurate readout of LAMP reaction results is crucial. Herein, a visual-mixed-dye (VMD) containing calcein (precombined with MnCl2) and hydroxynaphthol blue (HNB) for LAMP end-point detection was developed. The optimal final concentrations of these components in VMD were 25 and 300 µM, respectively. Due to the formation of HNBMn2+ during the LAMP reaction, the VMD-loaded assay exhibited superior visual properties, changing from light gray (negative) to dark blue (positive) under natural light. Additionally, compared with traditional single calcein or HNB dye, a weakly positive result with the VMD was purple, making it easier to distinguish by the naked eye. The visual sensitivity reached down to 20.9 copies/µL, which was comparable to that based on fluorescence. In food-contaminated samples, the practicality of VMD was verified by Vibrio parahaemolyticus and Staphylococcus aureus detection with excellent specificity. Moreover, the VMD was stable over a period of 3 months. Collectively, these findings establish the VMD as a novel dye for LAMP.

Colorimetric detection of Staphylococcus aureus using gold nanorods labeled with yolk immunoglobulin and urease, magnetic beads, and a phenolphthalein impregnated test paper.

A colorimetric test is described for the rapid detection of Staphylococcus aureus (SA). Gold nanorods (AuNRs) are first labeled with urease and yolk immunoglobulin (IgY). This probe can specifically bind SA. In the next step, nonspecific magnetic beads and sample are added. This leads to the formation of the AuNR-IgY-SA-nMB immunocomplex which is then magnetically separated. Finally, a solution of urea is added to the supernatant. Ureases catalyzes the decomposition of urea which results in an increase in the pH value. The increase in the pH value is detected by using a phenolphthalein test paper which undergoes a color change from white to pink. The analytical process can be completed within 20 min. The method is highly specific and can detect as little as 476 cfu·mL-1. It was verified by analyzing contaminated Chinese cabbage and beef samples, and 1000 cfu·mL-1 of SA were accurately detected. Graphical abstract Schematic representation of a colorimetric method for the detection of Staphylococcus aureus based on the immunocomplex formed from dual-labeled gold nanorod (AuNR) probe, bacteria and non-specific magnetic bead (nMB). This method can be completed within 20 min.

AMPK alleviates endoplasmic reticulum stress by inducing the ER-chaperone ORP150 via FOXO1 to protect human bronchial cells from apoptosis.

Chronic obstructive pulmonary disease (COPD), is characterized by inflammation of airways accompanied by a progressive destruction of lung parenchyma. This process is initiated in most cases by cigarette smoking. In this study we investigated the role of AMP activated protein kinase (AMPK) in cigarette smoke extract (CSE)-induced airway epithelial cell apoptosis as a consequence of endoplasmic reticulum stress (ER stress). Exposure of human bronchial epithelial cells (HBEpC) to CSE resulted in apoptosis as detected using Annexin V-PI flow cytometry. However, co-treatment with N1-(ß-d-ribofuranosyl)-5-aminoimidazole-4-carboxamide (AICAR), a pharmacological activator of AMPK, significantly increased cell protection against ER stress-induced apoptosis by upregulating the 150 kDa oxygen-regulated protein (ORP150), which functions as an ER-associated chaperone, with concomitant elevation of FOXO1, a critical transcription factor regulating ORP150 expression. Lentiviral silencing of AMPK or FOXO1 using short hairpin (sh) RNA resulted in a significant decrease of ORP150 and an elevation of CCAAT/enhancer-binding protein-homologous protein (CHOP) resulting in ER stress and apoptosis of HBEpC. Together, our results strongly suggest that AMPK can activate ORP150 through FOXO1 pathway and confer protection against ER stress-induced apoptosis of airway epithelial cells following exposure to CSE. Thus, AMPK may serve as a likely therapeutic target for clinical and sub-clinical interventions in COPD.

Xuebijing combined with ulinastation benefits patients with sepsis: A meta-analysis.

BACKGROUND: The potential benefits and possible risks associated with Xuebijing when combined with ulinastatin for sepsis treatment are not fully understood. METHODS: Databases, such as PubMed, Web of Science, CNKI, WanFang and VIP, were searched to collect randomized, controlled trials. Studies were screened, data were extracted, and the methodological quality was assessed by two reviewers independently. A meta-analysis was carried out with Stata 11.0 software. RESULTS: A total of 16 studies involving 1192 participants were enrolled for meta-analysis based on the inclusion and exclusion criteria. The results showed that compared with the group using routine therapies and the group using a single administration of either ulinastatin or Xuebijing, the trial group using Xuebijing combined with ulinastatin was significantly superior in the following aspects: mortality (RR = 0. 54,95% CI (0. 41, 0. 70, P = .000), 7 d APACHE II (SMD = -1.21, 95%CI (-1.62, -0.80), P = .000), duration of mechanical ventilation (SMD = -1.21, 95%CI (-1.62, -0.80), P = .000), average length of time in the intensive care unit (SMD = -1.21, 95%CI (-1.62, -0.80), P = .000), incidence of multiple organ dysfunction syndromes (RR = 0. 54, 95% CI (0.41, 0. 70, P = .000), interleukin-6 (SMD = -1.36,95%CI (-2.46, -0.27), P = .000), lipopolysaccharide (SMD = -9.92, 95%CI (-11.7, -7.90), P = .006), and procalcitonin (SMD = -0.30, 95%CI (-0.34, -0.26), P = .012). CONCLUSIONS: Our results found that Xuebijing when combined with ulinastatin was superior to both routine therapies and the single administration of either ulinastatin or Xuebijing. This finding provides a new therapeutic option for the treatment of sepsis.

A silica sands-based method for faithful analysis of microbial communities and DNA isolation from a wide range of species.

A silica sands-based method has been developed to isolate high quality genomic DNAs from cells of animals, plants and microorganisms, such as Hemisalanx prognathus, Spinacia oleracea, Pichia pastoris, Bacillus licheniformis and Escherichia coli. To the best of our knowledge, no DNA isolation method has so wide application until now. In addition, this method and a commercially available kit were compared in analysis of microbial communities using high-throughput 16s rDNA sequencing. As a result, the silica sands-based method was found to be even more efficient in isolating genomic DNA from gram-positive bacteria than the kit, indicating that it would become a very valuable choice to faithfully reflect the composition of microbial communities.

A Flexible Doubly Interpenetrated Metal-Organic Framework with Breathing Behavior and Tunable Gate Opening Effect by Introducing Co2+ into Zn4O Clusters.

A Zn4O clusters based flexible doubly interpenetrated metal-organic framework [(Zn4O)2(DCPB)6DMF]·2DMF·8H2O (JLU-Liu33, H2DCPB = 1,3-di(4-carboxyphenyl)benzene, DMF = N,N-dimethylformamide) with pcu topology has been solvothermally synthesized. Because of its flexible structure, JLU-Liu33 exhibits a breathing behavior upon N2 and CO2 adsorption at low temperature, and C2H6 and C3H8 adsorption at 273 and 298 K. Furthermore, by adopting the direct synthesis method, two isomorphic compounds-JLU-Liu33L and JLU-Liu33H-have been obtained by partial substituting Zn with different amounts of Co into the JLU-Liu33 framework. The gas adsorption study of Co-doped materials reveals that the gate opening effect of JLU-Liu33 can be modulated by introducing different contents of Co2+ into Zn4O clusters. Meanwhile, with the increasing amount of Co2+, the adsorption amount and isosteric enthalpy values for CO2 have been improved. It is worth mentioning that JLU-Liu33H exhibits commendable selectivity for CO2 over CH4 which may be a good candidate for industrial gas purification and air separation applications.

The Effects of Antismoking Messages From Family, School, and Mass Media on Smoking Behavior and Smoking Intention Among Chinese Adolescents.

The prevalence of adolescent smoking has been increasing rapidly in China. Expanding adolescent exposure to antismoking messages may be an effective approach to prevent tobacco use among this population. Using a cross-sectional sample of 8,444 high school students in four Chinese cities, this study assessed the relation between self-reported exposure to antismoking messages from families, schools, and mass media and the rate of past 30-day smoking and smoking intention among junior and senior high school students. Results from logistic regression suggested that antismoking messages delivered via school and media inhibited both tobacco use and the intention to smoke. The effects of familial warnings about harmful effects of smoking, in contrast, were at best insignificant.

A method suitable for DNA extraction from humus-rich soil.

A rapid and convenient method for extracting DNA from soil is presented. Soil DNA is extracted by direct cell lysis in the presence of EDTA, SDS, phenol, chloroform and isoamyl alcohol (3-methyl-1-butanol) followed by precipitation with 2-propanol. The extracted DNA is purified by modified DNA purification kit and DNA gel extraction kit. With this method, DNA extracted from humus-rich dark brown forest soil was free from humic substances and, therefore, could be used for efficient PCR amplification and restriction digestion. In contrast, DNA sample extracted with the traditional CTAB-based method had lower yield and purity, and no DNA could be extracted from the same soil sample with a commonly-used commercial soil DNA isolation kit. In addition, this method is time-saving and convenient, providing an efficient choice especially for DNA extraction from humus-rich soils.