The traditional nanozymes-based ratiometric fluorescence sensing platforms usually necessitate the supplementary addition of fluorescent probes,therefore greatly restricting its convenient and broad application.In thi...The traditional nanozymes-based ratiometric fluorescence sensing platforms usually necessitate the supplementary addition of fluorescent probes,therefore greatly restricting its convenient and broad application.In this study,a highly sensitive and selective ratiometric fluorescence platform for alkaline phosphatase(ALP)detection was established,only employing Prussian blue(PB)nanozymes and a commercially available chromogen of o-phenylenediamine(OPD).PB nanozymes with remarkable peroxidaselike(POD-like)activity can effectively catalyze OPD chromogen to yield 2,3-diaminophenazine(OPDox)with an intense yellow fluorescence at 573 nm emission peak.Target ALP can facilitate ascorbic acid 2-phosphate(AAP)dephosphorylation to generate phosphate and ascorbic acid(AA).Significantly,both these two resultant hydrolysis products could effectively decrease the OPDox generation via a dualpath based inhibition on the PB nanozymes POD-like activity.On the other hand,the generated dehydroascorbic acid(DHAA)from AA oxidation would exclusively react with OPD chromogen to yield3-(dihydroxyethyl)furo[3,4-b]quinoxaline-1-one(DFQ)with a strong blue fluorescent signal at 434nm,which further providing a significant enhancement on the sensing selectivity of ALP detection.As a result,an increased yellow fluorescence of OPDox and decreased blue fluorescence of DFQ could be clearly observed with different ALP addition.A robust linear relationship between the fluorescence ratio of F_(434)/F_(573)and ALP activity ranging from 0.25U/L to 6U/L was obtained,with a low detection limit of 0.112 U/L.This proposed method demonstrates high sensitivity,excellent selectivity,cost-effectiveness,and operational simplicity,yet enabling an effective detection of ALP levels in human serum.展开更多
[Objectives]To evaluate the performance of two rapid chromogenic media for the detection of Bacillus cereus in milk powder,and verify the media's inclusivity,exclusivity,and accuracy,and to assess their applicabil...[Objectives]To evaluate the performance of two rapid chromogenic media for the detection of Bacillus cereus in milk powder,and verify the media's inclusivity,exclusivity,and accuracy,and to assess their applicability for the quantitative detection of B.cereus.[Methods]B.cereus in milk powder samples was quantified using two rapid chromogenic media in combination with the national standard method.Agreement between the quantitative results from the three methods was subsequently assessed for agreement via a paired t-test.[Results]No significant differences were observed between the bacterial counts yielded by the two rapid chromogenic media and the national standard method(P>0.05),with excellent agreement between them.[Conclusions]The method of rapid chromogenic culture medium is rapid and simple.展开更多
[Objectives]To explore the methods for identifying pure honey.[Methods]Using 35 batches of Jiulongteng honey sourced from various production areas in Guangxi as the research subjects,this study investigated the chromo...[Objectives]To explore the methods for identifying pure honey.[Methods]Using 35 batches of Jiulongteng honey sourced from various production areas in Guangxi as the research subjects,this study investigated the chromogenic reactions of starch and dextrin,as well as the comparative study of thin-layer chromatography of oligosaccharides present in Jiulongteng honey.[Results]None of the 35 batches of Jiulongteng honey samples exhibited blue(indicating starch),green,or reddish-brown(indicating dextrin)coloration,suggesting that no adulterants such as artificially added starch,dextrin,or sugar were present in these samples.Furthermore,none of the 35 batches displayed additional spots below the corresponding positions of the control,indicating that the sugar composition was consistent with the oligosaccharide profile of natural honey.No components inconsistent with the oligosaccharide profile of natural honey were detected.Therefore,it can be concluded that the Jiulongteng honey samples in this experiment were pure and free from adulteration with starch,dextrin,or other sugar substances.[Conclusions]The method employed in this experiment is straightforward and quick to implement,effectively preventing adulterated honey from entering the market.It enhances the efficiency of quality control for Jiulongteng honey and promotes the healthy development of the Jiulongteng honey industry.展开更多
BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited...BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited due to the organism’s fastidious growth requirements and prolonged culture time.AIM To propose a novel detection method utilizing antibiotic-supplemented media to inhibit susceptible strains,while resistant isolates were identified through urease-mediated hydrolysis of urea,inducing a phenol red color change for visual confirmation.METHODS Colombia agar was supplemented with urea,phenol red,and nickel chloride,and the final pH was adjusted to 7.35.Antibiotic-selective media were prepared by incorporating amoxicillin(0.5μg/mL),clarithromycin(2μg/mL),metronidazole(8μg/mL),or levofloxacin(2μg/mL)into separate batches.Gastric antral biopsies were homogenized and inoculated at 1.0×105 CFU onto the media,and then incubated under microaerobic conditions at 37°C for 28-36 hours.Resistance was determined based on a color change from yellow to pink,and the results were validated via broth microdilution according to Clinical and Laboratory Standards Institute guidelines.RESULTS After 28-36 hours of incubation,the drug-resistant H.pylori isolates induced a light red color change in the medium.Conversely,susceptible strains(H.pylori 26695 and G27)produced no visible color change.Compared with the conventional 11-day protocol,the novel method significantly reduced detection time.Among 201 clinical isolates,182 were successfully evaluated using the new method,resulting in a 90.5%detection rate.This was consistent with the 95.5%agreement rate observed when compared with microdilution-based susceptibility testing.The success rate of the novel approach was significantly higher than that of the comparative method(P<0.01).The accuracy of the new method was comparable to that of the dilution method.CONCLUSION The novel detection method can rapidly detect H.pylori drug resistance within 28-36 hours.With its operational simplicity and high diagnostic performance,it holds strong potential for clinical application in the management of H.pylori antimicrobial resistance.展开更多
AIM:To assess human epidermal growth factor receptor-2 (HER2)-status in gastric cancer and matched lymph node metastases by immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH).METHODS:120 cases of ...AIM:To assess human epidermal growth factor receptor-2 (HER2)-status in gastric cancer and matched lymph node metastases by immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH).METHODS:120 cases of primary gastric carcinomas and 45 matched lymph node metastases from patients with full clinicopathological features were mounted onto multiple-punch and single-punch tissue microarrays,respectively,and examined for HER2 overexpression and gene amplification by IHC and CISH.RESULTS:Twenty-four tumors (20%) expressed HER2 immunohistochemically.An IHC score of ≥ 2+ was observed in 20 tumors (16.6%).HER2 amplification was detected by CISH in 19 tumors (15.8%) and in their matched lymph node metastases.A high concordancerate was found between HER2 positivity (as detected by IHC) and HER2 gene amplification (as detected by CISH),since 19 of the 20 IHC positive cases were amplified (95%).All amplified cases had 2+ or 3+ IHC results.Amplification was associated with intestinal phenotype (P < 0.05).No association with grading,staging or survival was found.CONCLUSION:In gastric cancer,HER2 amplification is the main mechanism for HER2 protein overexpression and is preserved in lymph node metastases.展开更多
A novel method is developed for the determination of cefradine by using sodium nitroprusside as chromogenic reagent. The experiment indicates that a russety product is formed by the reaction of cefradine with sodium n...A novel method is developed for the determination of cefradine by using sodium nitroprusside as chromogenic reagent. The experiment indicates that a russety product is formed by the reaction of cefradine with sodium nitroprusside in basic solution, and the maximum absorption wavelength （λmax） of russety product is 505 rim. And the sensitization of tetradecyl benzyl dimethyl ammonium chloride for the reaction of cefradine with sodium nitroprusside is remarkable, The apparent molar absorption coefficient （5505） is 2.81 × 103 L/mol cm. The linear equation isA = 0.0657 ＋ 0.00804C （μg/mL） in the range of 1.50-55.0μg/mL of cefradine with a correlation coefficient r = 0.9992, and the detection limit is 1.38 p,g/mL. This method has been applied to determine cefradine in capsule and tablet samples.展开更多
At 0.12 mmol/L γ-glutamyl p-nitroaniline(GGPNA),an improved integrated method was developed for kinetic analysis of γ-glutamyltransferase(GGT) reaction process and the integration with the classical initial rate met...At 0.12 mmol/L γ-glutamyl p-nitroaniline(GGPNA),an improved integrated method was developed for kinetic analysis of γ-glutamyltransferase(GGT) reaction process and the integration with the classical initial rate method to measure serum GGT.For the improved integrated method,an integrated rate equation,which used the predictor variable of reaction time and considered inhibitions by both GGPNA and products,was nonlinearly fit to GGT reaction processes.For the integration strategy,classical initial rates were estimated when GGPNA consumption percentages were below 50%;otherwise,maximal reaction rates of GGT were estimated by the improved integrated method and converted into initial rates according to the differential rate equation at 0.11 mmol/L GGPNA.The inte-gration strategy was validated using optimized GGT kinetic parameters and 10-s intervals to record reaction curves within 8.0 min.By the integration strategy,there was a linear response from 0.9 to 32.0 U/L GGT,coefficients of variation were below 3.5%for GGT from 8.0 to 32.0 U/L(n=5) ,and GGT activities in clinical sera responded linearly to their classical initial rates at 2.00 mmol/L GGPNA with an expected slope.Therefore,the integration strategy was successful in measuring GGT at 0.12 mmol/L GGPNA.展开更多
Traditional colorimetric glucose biosensor generally involves complex assay procedures.Free labile enzymes and peroxidase substrates are used separately for triggering a chromogenic reaction.These limits result in inf...Traditional colorimetric glucose biosensor generally involves complex assay procedures.Free labile enzymes and peroxidase substrates are used separately for triggering a chromogenic reaction.These limits result in inferior enzyme stability and defective enzymatic catalytic efficiency,making it hard to routinely utilize them for the direct and fast test of glucose.In this work,we provide an all-inclusive substrates/enzymes nanoparticle employed 3,3’5,5’-tetramethylbenzidine(TMB) as chromogenic substrates and glucose oxidase(GOx)/horseradish peroxidase(HRP) as signal amplifier enzymes(TMB-GH NPs) by the molecule self-assembly technique.The "all-inclusive" nanoparticles can realize the tandem colorimetric reactions,and the oxidation product of TMB(ox-TMB) exhibits a strong NIR laserdrive n photothermal effect,thus allowing qua ntitative photothermal detection of glucose.Owing to the restriction of the molecular motion of GOx,HRP,and TMB,the distance of mass transfer between substrates was s hortened largely,leading to improved catalytic activity for glucose.Overall,our strategy will simplify the analysis procedure,furthermore,these integrated nanoparticles not only display higher stability and activity than that of the free GOx/HRP system and possesses an excellent performance for colorimetric and photothermal bioassay of glucose simultaneously.We believe that this unique technique will give good inspirations to develop simple and precise methods for bioassay.展开更多
A chemical system for facile and accurate detection of 2,4-dichlorophenol （DCP） via iron （Ⅱ） phthalocyanine （Fe（Ⅱ）Pc） catalyzed chromogenic reaction is reported for the first time. In this system, DCP could ...A chemical system for facile and accurate detection of 2,4-dichlorophenol （DCP） via iron （Ⅱ） phthalocyanine （Fe（Ⅱ）Pc） catalyzed chromogenic reaction is reported for the first time. In this system, DCP could be oxidized by dioxygen with the catalysis of Fe（Ⅱ）Pc and then coupled with 4-aminoantipyrine （4-AAP） to generate pink antipyrilquinoneimine dye. Control experiments showed that the addition of ethanol could obviously enhance the catalytic activity of heterogeneous Fe（Ⅱ）Pc catalysts because of the partial dissolution of Fe（II）Pc nanocubes, which was confirmed by the SEM analysis. On the basis of the detection results of DCP in the range from 2×10^-5 to 9×10^-4 mol/L, we obtained a regression equation （A = 0.187 5 ＋ 0.01 209C （R2=-0.995 6）） with the detection limit （3σ） of 3.26×10^-6 mol/L, which could be successfully used in detecting the real samples.展开更多
This letter reports a novel method for preparing chromogenic calix[4]arenes, in which the 4-aminopyridine was diazotized with isoamyl nitrite in EtONa/EtOH, and mono(azo)-, bis(azo)- and tetra(azo)-substituted calix[4...This letter reports a novel method for preparing chromogenic calix[4]arenes, in which the 4-aminopyridine was diazotized with isoamyl nitrite in EtONa/EtOH, and mono(azo)-, bis(azo)- and tetra(azo)-substituted calix[4]arenes were obtained as main product respectively by diazo-coupling in different molar ratio to calix[4]arene in non-aqueous solution at 0-5 degrees.展开更多
Background: Colonization with methicillin-resistant Staphylococcus aureus(MRSA) poses a hygiene risk that does not spare field hospitals or military medical field camps during military deployments. Diagnostic options ...Background: Colonization with methicillin-resistant Staphylococcus aureus(MRSA) poses a hygiene risk that does not spare field hospitals or military medical field camps during military deployments. Diagnostic options for unambiguously identifying MRSA isolates are usually scarce in military environments. In this study, we assessed the stepwise application of two different selective agars for the specific identification of MRSA in screening analyses.Methods: Nasal swabs from 1,541 volunteers were subjected to thioglycollate broth enrichment and subsequently screened on CHROMagar MRSA selective agar for the identification of MRSA. The MRSA identity of suspiciouslooking colonies was confirmed afterwards or excluded by another selective agar, chrom ID MRSA. All isolates from the selective agars with MRSA-specific colony morphology were identified by biochemical methods and mass spectrometry.Results: The initial CHROMagar MRSA screening identified suspicious colonies in 36 out of 1541 samples. A total of 25 of these 36 isolates showed MRSA-like growth on chrom ID agar. Out of these 25 isolates, 24 were confirmed as MRSA, while one isolate was identified as Staphylococcus kloosii. From the 11 strains that did not show suspicious growth on chrom ID agar, 3 were methicillin-sensitive Staphylococcus aureus(MSSA, with one instance of cocolonization with Corynebacterium spp.), 2 were confirmed as MRSA(with 1 instance of co-colonization with MSSA), 2 were lost during passaging and could not be re-cultured, one could not be identified by the applied approaches, and the remaining 3 strains were identified as Staphylococcus saprophyticus, Staphylococcus hominis(co-colonized with Macrococcus caseolyticus) and Staphylococcus cohnii, respectively.Conclusion: The application of the selective agar CHROMagar MRSA alone proved to be too non-specific to allow for a reliable diagnosis of the presence of MRSA. The combined use of two selective agars in a stepwise approach reduced this non-specificity with an acceptably low loss of sensitivity. Accordingly, such a stepwise screening approach might be an option for resource-restricted military medical field camps.展开更多
Summary： The specimens of ductal carcinoma in situ （DCIS） with early invasion, and specimens col- lected by core needle biopsy （CNB） tend to contain limited amount of invasive component, so it is im- perative to ...Summary： The specimens of ductal carcinoma in situ （DCIS） with early invasion, and specimens col- lected by core needle biopsy （CNB） tend to contain limited amount of invasive component, so it is im- perative to explore a new technique which can assess HER2 gene status accurately for the limited inva- sive cancer component in these specimens. Dual staining technique of combining immunohistochemis- try （IHC） for myoepithelial cells and single or dual probe chromogenic in situ hybridization （CISH） for HER2 gene was performed on routinely processed paraffin sections from 20 cases diagnosed as having DCIS with invasive cancer. Among them, 10 had fluorescence in situ hybridization （FISH）-confirmed amplification of HER2 and 10 had FISH-confirmed non-amplification of HER2. We successfully de- tected HER2 genetic signals and myoepithelial IHC markers （SMM-HC or CK5/6） simultaneously on a single section in all 20 specimens. Myoepithelial markers and HER2 signals detected by dual staining assay were consistent with those by individual technique performed alone. HER2 gene amplification results determined by dual staining assay were 100% consistent with those of FISH. Dual staining tech- nique which allows simultaneous detection of myoepithelial marker protein and cancerous HER2 gene is feasible, and it has potential to be used in clinical practice for effective determination of HER2 ampli- fication in limited invasive component.展开更多
The heteroligand complex of manganese with 1,10-phenantroline and o-nitrobenzolazosalicylic acid has been investigated by spectrophotometric method. The condition of complexing and extraction, physical-chemical and an...The heteroligand complex of manganese with 1,10-phenantroline and o-nitrobenzolazosalicylic acid has been investigated by spectrophotometric method. The condition of complexing and extraction, physical-chemical and analytical characteristics of this complex have been found. Complex formation is observed in the pH range 5 - 11. Extraction constant was found as 5.3 × 1012, stability constant was found as lgβK = 9.03?± 0.03. Molar absorptivity is ε = (1.36 ± 0.08) × 104 l·g﹣1·cm﹣1. Beer's law is obeyed in the range of 1.0 - 22.5 μkg manganese (II). The extraction-photometric methods of manganese determination have been worked out. The influence of diverse ions on determination of manganese (II) has been studied. The proposed method was applied successfully to determine amount of manganese in tap water.展开更多
A diester-calix[4]crown-4-ether bearing mono (azophenol) moiety shows a larger spectral change toward Ca2+ than other alkali and alkaline eafth cations.
The traditional surfactant sodium dodecyl sulfate（SDS） and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate（[Emim][BF4]） have been combined to create a novel efficient medium for chromogenic catalysis of...The traditional surfactant sodium dodecyl sulfate（SDS） and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate（[Emim][BF4]） have been combined to create a novel efficient medium for chromogenic catalysis of 3,30,5,50-tetramethylbenzidine with horseradish peroxidase in presence of H2O2. The results have shown the [Emim][BF4] in the mediums can promote the rate of formation of the blue chromogen,the SDS is responsible for the stabilization of the blue chromogen due to the electrostatic attraction between positively charged blue chromogen and the negatively charged surfactant. The SDS/[Emim][BF4]combination not only enhance catalytic activity of HRP remarkably but also stabilize the blue chromogen formed in the HRP oxidation of the substrate TMB compared to the conventional medium. Based on the superior combination of SDS and [Emim][BF4], the colorimetric assay for detecting HRP activity and H2O2 concentration was established. This work demonstrates a novel efficient medium for chromogenic catalysis with potential applications in biosensors and clinical diagnosis.展开更多
[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from ...[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from arthritis and named as the strain Gg1.[Result]It was then identified as Staphylococcus chromogenes by the biochemical tests and phylogenetic tree analysis based on 16S rDNA sequence.Furthermore,the catalase（katA）gene was amplified by PCR using the designed primers,and the expected fragment was 1 232 bp long encoding a protein of 410 amino acids that shares the conserved motifs including catalase,heme-binding ligand and active center motif.Six phosphorylation sites（Ser95,Thr96,Ser241,Ser242,Thr281,Ser338）,four conserved residues（Ser95,His216,Tyr281,Asp341）and two active sites（His56,Asn129）were demonstrated by multiple sequence alignment and homology comparisons.The homology modeling of 3D structure of katA protein was done by SWISSMODEL server based on the template retrieved from the catalase（PDB：2ISA_A）of Vibrio salmonicida.The katA protein represents a four-domain globular protein,the quality and reliability of the resulting protein structure was further verified by Ramachandran plot.[Conclusion]To our knowledge,this is the first report of S.chromogenes linked to arthritis in chicken and the bioinformatic characterization of its katA gene.展开更多
Chromogenic windows enable both energy-saving and daylighting regulation.However,the human response to the luminous environment affected by them is difficult to test,since their features of dynamic change and tinting ...Chromogenic windows enable both energy-saving and daylighting regulation.However,the human response to the luminous environment affected by them is difficult to test,since their features of dynamic change and tinting automatically.This study explores the research methods,including experimental design and statistical analysis,by literature review and an experiment demonstration.The results show that a proper size of the test room is significant to obtain desired data,and the advanced VR technologies have the potential to be applied for testing these dynamic variables.Bayesian approaches are recommended to be tried and get more accurate interference about the experimental results.展开更多
Background Subclinical mastitis,caused by many pathogens including Staphylococcus aureus(S.aureus)and Staphylococcus chromogenes(S.chromogenes),presents a major challenge to the dairy industry due to its associated ec...Background Subclinical mastitis,caused by many pathogens including Staphylococcus aureus(S.aureus)and Staphylococcus chromogenes(S.chromogenes),presents a major challenge to the dairy industry due to its associated economic losses and poor milk quality.The molecular regulatory mechanisms,including the role of small nucleolar RNAs(snoRNAs),of the host response to mastitis pathogens remain unclear.Therefore,this study investigated snoRNA expression and potential roles during subclinical mastitis.Milk somatic cells from cows with naturally occurring S.aureus(n=14)and S.chromogenes(n=3)subclinical mastitis,and healthy cows(n=4)were subjected to transcriptome sequencing and bioinformatics analyses.Results We identified 255 expressed snoRNAs including 21 differentially expressed(DE)in S.aureus-positive cows and 20 DE in S.chromogenes-positive cows.Prediction of ribosomal RNA(rRNA)modification sites found several 18S rRNA and 28S rRNA modification(pseudouridylation and 2′-O-methylation)target sites essential for ribosome function for DE snoRNAs,such as SNORA79(18S-1319,28S-3001),SNORA1(18S-1496,28S-1747),suggesting their roles in translation and immune modulation during subclinical mastitis.Correlation analysis identified DE snoRNAs-mRNAs(from the same samples)pairs with majority of the correlated mRNAs(e.g.,CXCL8,IL6R,IL2,IL1R,IL18R1,STAT3,NFKB2,MYD88,VEGFA,and CD40)having immune related functions.Functional enrichment of correlated genes of snoRNAs for S.aureus-positive group(regulation of defense/immune response,leukocyte differentiation,response to cytokine,NF-κB signaling pathway,JAK-STAT signaling pathway etc.)and S.chromogenes-positive group(e.g.,regulation of defense response,response to cytokine,regulation of immune response,NF-κB signaling pathway,TNF signaling pathway,and JAK-STAT signaling pathway)revealed involvement in immune and inflammatory processes.Some functional terms were common to both pathogens(e.g.,NF-κB,JAK-STAT signaling,immune system processes)and suggest common regulatory mechanisms used by both pathogens to contain infection.Furthermore,snoRNA-mRNA network construction identified 7 key(hub)snoRNAs each for S.aureus-positive group(SNORA66,novelsnoRNA_26_14905(also denoted as novelSnoRNA_86),SNORD107,SNORA1,SNORA63,SNORA79,SNORA76)and S.chromogenes-positive group(SNORD18,SNORA79,SNORA46,U2-19,SNORA66,SNORD37,SNORD49)that correlated with the most protein coding genes(|r|>0.9;≥30 mRNAs).Functional enrichment of correlated genes of hub snoRNAs reveals their involvement in immune related functions(75%of enriched terms)and metabolic processes(20%of enriched terms).Conclusion These data suggest potential regulatory roles for the DE snoRNAs and in particular,the 14 hub snoRNAs during subclinical mastitis.This study presents the first evidence linking snoRNAs to bovine subclinical mastitis and offers new insights into the molecular mechanisms underlying subclinical mastitis caused by S.aureus and S.chromogenes.展开更多
基金supported by the National Natural Science Foundation of China(No.22064014)the Science and Technology Development Plan Project of Lanzhou(No.2021–1-146)+2 种基金the Science and Technology Project of Gansu Province(Nos.21YF5FA071,21JR7RA538)the Industrial Support Programme for Higher Education Institutions Project(Nos.2023CYZC-69,2024CYCZ-05)the 2023 Gansu Provincial Key Talent Project(No.2023RCXM26)。
文摘The traditional nanozymes-based ratiometric fluorescence sensing platforms usually necessitate the supplementary addition of fluorescent probes,therefore greatly restricting its convenient and broad application.In this study,a highly sensitive and selective ratiometric fluorescence platform for alkaline phosphatase(ALP)detection was established,only employing Prussian blue(PB)nanozymes and a commercially available chromogen of o-phenylenediamine(OPD).PB nanozymes with remarkable peroxidaselike(POD-like)activity can effectively catalyze OPD chromogen to yield 2,3-diaminophenazine(OPDox)with an intense yellow fluorescence at 573 nm emission peak.Target ALP can facilitate ascorbic acid 2-phosphate(AAP)dephosphorylation to generate phosphate and ascorbic acid(AA).Significantly,both these two resultant hydrolysis products could effectively decrease the OPDox generation via a dualpath based inhibition on the PB nanozymes POD-like activity.On the other hand,the generated dehydroascorbic acid(DHAA)from AA oxidation would exclusively react with OPD chromogen to yield3-(dihydroxyethyl)furo[3,4-b]quinoxaline-1-one(DFQ)with a strong blue fluorescent signal at 434nm,which further providing a significant enhancement on the sensing selectivity of ALP detection.As a result,an increased yellow fluorescence of OPDox and decreased blue fluorescence of DFQ could be clearly observed with different ALP addition.A robust linear relationship between the fluorescence ratio of F_(434)/F_(573)and ALP activity ranging from 0.25U/L to 6U/L was obtained,with a low detection limit of 0.112 U/L.This proposed method demonstrates high sensitivity,excellent selectivity,cost-effectiveness,and operational simplicity,yet enabling an effective detection of ALP levels in human serum.
基金Supported by the Inner Mongolia Autonomous Region's Key Research and Achievement Transformation Plan(2025YFSH0029).
文摘[Objectives]To evaluate the performance of two rapid chromogenic media for the detection of Bacillus cereus in milk powder,and verify the media's inclusivity,exclusivity,and accuracy,and to assess their applicability for the quantitative detection of B.cereus.[Methods]B.cereus in milk powder samples was quantified using two rapid chromogenic media in combination with the national standard method.Agreement between the quantitative results from the three methods was subsequently assessed for agreement via a paired t-test.[Results]No significant differences were observed between the bacterial counts yielded by the two rapid chromogenic media and the national standard method(P>0.05),with excellent agreement between them.[Conclusions]The method of rapid chromogenic culture medium is rapid and simple.
基金Supported by Enhancement Project of Basic Scientific Research Ability of Young and Middle-aged Teachers in Guangxi Universities(2020KY07040)School-level Scientific Research Project of Guangxi University of Chinese Medicine(2024QN022)Self-financed Scientific Research Project of Guangxi Zhuang Autonomous Region Administration of Traditional Chinese Medicine(GXZYL20240818).
文摘[Objectives]To explore the methods for identifying pure honey.[Methods]Using 35 batches of Jiulongteng honey sourced from various production areas in Guangxi as the research subjects,this study investigated the chromogenic reactions of starch and dextrin,as well as the comparative study of thin-layer chromatography of oligosaccharides present in Jiulongteng honey.[Results]None of the 35 batches of Jiulongteng honey samples exhibited blue(indicating starch),green,or reddish-brown(indicating dextrin)coloration,suggesting that no adulterants such as artificially added starch,dextrin,or sugar were present in these samples.Furthermore,none of the 35 batches displayed additional spots below the corresponding positions of the control,indicating that the sugar composition was consistent with the oligosaccharide profile of natural honey.No components inconsistent with the oligosaccharide profile of natural honey were detected.Therefore,it can be concluded that the Jiulongteng honey samples in this experiment were pure and free from adulteration with starch,dextrin,or other sugar substances.[Conclusions]The method employed in this experiment is straightforward and quick to implement,effectively preventing adulterated honey from entering the market.It enhances the efficiency of quality control for Jiulongteng honey and promotes the healthy development of the Jiulongteng honey industry.
基金Supported by the Guangxi Science and Technology Major Projects,No.AA23073012the National Natural Science Foundation of China,No.32360035 and No.32060018。
文摘BACKGROUND Helicobacter pylori(H.pylori),a globally prevalent pathogen,is exhibiting increasing rates of antimicrobial resistance.However,clinical implementation of pre-treatment susceptibility testing remains limited due to the organism’s fastidious growth requirements and prolonged culture time.AIM To propose a novel detection method utilizing antibiotic-supplemented media to inhibit susceptible strains,while resistant isolates were identified through urease-mediated hydrolysis of urea,inducing a phenol red color change for visual confirmation.METHODS Colombia agar was supplemented with urea,phenol red,and nickel chloride,and the final pH was adjusted to 7.35.Antibiotic-selective media were prepared by incorporating amoxicillin(0.5μg/mL),clarithromycin(2μg/mL),metronidazole(8μg/mL),or levofloxacin(2μg/mL)into separate batches.Gastric antral biopsies were homogenized and inoculated at 1.0×105 CFU onto the media,and then incubated under microaerobic conditions at 37°C for 28-36 hours.Resistance was determined based on a color change from yellow to pink,and the results were validated via broth microdilution according to Clinical and Laboratory Standards Institute guidelines.RESULTS After 28-36 hours of incubation,the drug-resistant H.pylori isolates induced a light red color change in the medium.Conversely,susceptible strains(H.pylori 26695 and G27)produced no visible color change.Compared with the conventional 11-day protocol,the novel method significantly reduced detection time.Among 201 clinical isolates,182 were successfully evaluated using the new method,resulting in a 90.5%detection rate.This was consistent with the 95.5%agreement rate observed when compared with microdilution-based susceptibility testing.The success rate of the novel approach was significantly higher than that of the comparative method(P<0.01).The accuracy of the new method was comparable to that of the dilution method.CONCLUSION The novel detection method can rapidly detect H.pylori drug resistance within 28-36 hours.With its operational simplicity and high diagnostic performance,it holds strong potential for clinical application in the management of H.pylori antimicrobial resistance.
文摘AIM:To assess human epidermal growth factor receptor-2 (HER2)-status in gastric cancer and matched lymph node metastases by immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH).METHODS:120 cases of primary gastric carcinomas and 45 matched lymph node metastases from patients with full clinicopathological features were mounted onto multiple-punch and single-punch tissue microarrays,respectively,and examined for HER2 overexpression and gene amplification by IHC and CISH.RESULTS:Twenty-four tumors (20%) expressed HER2 immunohistochemically.An IHC score of ≥ 2+ was observed in 20 tumors (16.6%).HER2 amplification was detected by CISH in 19 tumors (15.8%) and in their matched lymph node metastases.A high concordancerate was found between HER2 positivity (as detected by IHC) and HER2 gene amplification (as detected by CISH),since 19 of the 20 IHC positive cases were amplified (95%).All amplified cases had 2+ or 3+ IHC results.Amplification was associated with intestinal phenotype (P < 0.05).No association with grading,staging or survival was found.CONCLUSION:In gastric cancer,HER2 amplification is the main mechanism for HER2 protein overexpression and is preserved in lymph node metastases.
文摘A novel method is developed for the determination of cefradine by using sodium nitroprusside as chromogenic reagent. The experiment indicates that a russety product is formed by the reaction of cefradine with sodium nitroprusside in basic solution, and the maximum absorption wavelength （λmax） of russety product is 505 rim. And the sensitization of tetradecyl benzyl dimethyl ammonium chloride for the reaction of cefradine with sodium nitroprusside is remarkable, The apparent molar absorption coefficient （5505） is 2.81 × 103 L/mol cm. The linear equation isA = 0.0657 ＋ 0.00804C （μg/mL） in the range of 1.50-55.0μg/mL of cefradine with a correlation coefficient r = 0.9992, and the detection limit is 1.38 p,g/mL. This method has been applied to determine cefradine in capsule and tablet samples.
基金Project supported by the National Natural Science Foundation of China (No.30200266)the Program for New Century Excellent Talents in University of Ministry of Education of China(No.NCET-09-928)
文摘At 0.12 mmol/L γ-glutamyl p-nitroaniline(GGPNA),an improved integrated method was developed for kinetic analysis of γ-glutamyltransferase(GGT) reaction process and the integration with the classical initial rate method to measure serum GGT.For the improved integrated method,an integrated rate equation,which used the predictor variable of reaction time and considered inhibitions by both GGPNA and products,was nonlinearly fit to GGT reaction processes.For the integration strategy,classical initial rates were estimated when GGPNA consumption percentages were below 50%;otherwise,maximal reaction rates of GGT were estimated by the improved integrated method and converted into initial rates according to the differential rate equation at 0.11 mmol/L GGPNA.The inte-gration strategy was validated using optimized GGT kinetic parameters and 10-s intervals to record reaction curves within 8.0 min.By the integration strategy,there was a linear response from 0.9 to 32.0 U/L GGT,coefficients of variation were below 3.5%for GGT from 8.0 to 32.0 U/L(n=5) ,and GGT activities in clinical sera responded linearly to their classical initial rates at 2.00 mmol/L GGPNA with an expected slope.Therefore,the integration strategy was successful in measuring GGT at 0.12 mmol/L GGPNA.
基金The authors would like to thank the financial support from Sichuan Province Science and Technology Support Program(No.2020YFN0029)the One-Thousand-Talents Scheme in Sichuan Province,Scientific Start-up Research Fund of Chengdu University of Information Technology(No.KYTZ201714).
文摘Traditional colorimetric glucose biosensor generally involves complex assay procedures.Free labile enzymes and peroxidase substrates are used separately for triggering a chromogenic reaction.These limits result in inferior enzyme stability and defective enzymatic catalytic efficiency,making it hard to routinely utilize them for the direct and fast test of glucose.In this work,we provide an all-inclusive substrates/enzymes nanoparticle employed 3,3’5,5’-tetramethylbenzidine(TMB) as chromogenic substrates and glucose oxidase(GOx)/horseradish peroxidase(HRP) as signal amplifier enzymes(TMB-GH NPs) by the molecule self-assembly technique.The "all-inclusive" nanoparticles can realize the tandem colorimetric reactions,and the oxidation product of TMB(ox-TMB) exhibits a strong NIR laserdrive n photothermal effect,thus allowing qua ntitative photothermal detection of glucose.Owing to the restriction of the molecular motion of GOx,HRP,and TMB,the distance of mass transfer between substrates was s hortened largely,leading to improved catalytic activity for glucose.Overall,our strategy will simplify the analysis procedure,furthermore,these integrated nanoparticles not only display higher stability and activity than that of the free GOx/HRP system and possesses an excellent performance for colorimetric and photothermal bioassay of glucose simultaneously.We believe that this unique technique will give good inspirations to develop simple and precise methods for bioassay.
基金Funded by the National Natural Science Foundation of China(No.61377092)
文摘A chemical system for facile and accurate detection of 2,4-dichlorophenol （DCP） via iron （Ⅱ） phthalocyanine （Fe（Ⅱ）Pc） catalyzed chromogenic reaction is reported for the first time. In this system, DCP could be oxidized by dioxygen with the catalysis of Fe（Ⅱ）Pc and then coupled with 4-aminoantipyrine （4-AAP） to generate pink antipyrilquinoneimine dye. Control experiments showed that the addition of ethanol could obviously enhance the catalytic activity of heterogeneous Fe（Ⅱ）Pc catalysts because of the partial dissolution of Fe（II）Pc nanocubes, which was confirmed by the SEM analysis. On the basis of the detection results of DCP in the range from 2×10^-5 to 9×10^-4 mol/L, we obtained a regression equation （A = 0.187 5 ＋ 0.01 209C （R2=-0.995 6）） with the detection limit （3σ） of 3.26×10^-6 mol/L, which could be successfully used in detecting the real samples.
文摘This letter reports a novel method for preparing chromogenic calix[4]arenes, in which the 4-aminopyridine was diazotized with isoamyl nitrite in EtONa/EtOH, and mono(azo)-, bis(azo)- and tetra(azo)-substituted calix[4]arenes were obtained as main product respectively by diazo-coupling in different molar ratio to calix[4]arene in non-aqueous solution at 0-5 degrees.
文摘Background: Colonization with methicillin-resistant Staphylococcus aureus(MRSA) poses a hygiene risk that does not spare field hospitals or military medical field camps during military deployments. Diagnostic options for unambiguously identifying MRSA isolates are usually scarce in military environments. In this study, we assessed the stepwise application of two different selective agars for the specific identification of MRSA in screening analyses.Methods: Nasal swabs from 1,541 volunteers were subjected to thioglycollate broth enrichment and subsequently screened on CHROMagar MRSA selective agar for the identification of MRSA. The MRSA identity of suspiciouslooking colonies was confirmed afterwards or excluded by another selective agar, chrom ID MRSA. All isolates from the selective agars with MRSA-specific colony morphology were identified by biochemical methods and mass spectrometry.Results: The initial CHROMagar MRSA screening identified suspicious colonies in 36 out of 1541 samples. A total of 25 of these 36 isolates showed MRSA-like growth on chrom ID agar. Out of these 25 isolates, 24 were confirmed as MRSA, while one isolate was identified as Staphylococcus kloosii. From the 11 strains that did not show suspicious growth on chrom ID agar, 3 were methicillin-sensitive Staphylococcus aureus(MSSA, with one instance of cocolonization with Corynebacterium spp.), 2 were confirmed as MRSA(with 1 instance of co-colonization with MSSA), 2 were lost during passaging and could not be re-cultured, one could not be identified by the applied approaches, and the remaining 3 strains were identified as Staphylococcus saprophyticus, Staphylococcus hominis(co-colonized with Macrococcus caseolyticus) and Staphylococcus cohnii, respectively.Conclusion: The application of the selective agar CHROMagar MRSA alone proved to be too non-specific to allow for a reliable diagnosis of the presence of MRSA. The combined use of two selective agars in a stepwise approach reduced this non-specificity with an acceptably low loss of sensitivity. Accordingly, such a stepwise screening approach might be an option for resource-restricted military medical field camps.
基金supported by grants from the Natural Science Foundation of Hubei Province (No. 2008CDB152)Science and Technology Foundation of Hubei Province (No.2007AA402A40)
文摘Summary： The specimens of ductal carcinoma in situ （DCIS） with early invasion, and specimens col- lected by core needle biopsy （CNB） tend to contain limited amount of invasive component, so it is im- perative to explore a new technique which can assess HER2 gene status accurately for the limited inva- sive cancer component in these specimens. Dual staining technique of combining immunohistochemis- try （IHC） for myoepithelial cells and single or dual probe chromogenic in situ hybridization （CISH） for HER2 gene was performed on routinely processed paraffin sections from 20 cases diagnosed as having DCIS with invasive cancer. Among them, 10 had fluorescence in situ hybridization （FISH）-confirmed amplification of HER2 and 10 had FISH-confirmed non-amplification of HER2. We successfully de- tected HER2 genetic signals and myoepithelial IHC markers （SMM-HC or CK5/6） simultaneously on a single section in all 20 specimens. Myoepithelial markers and HER2 signals detected by dual staining assay were consistent with those by individual technique performed alone. HER2 gene amplification results determined by dual staining assay were 100% consistent with those of FISH. Dual staining tech- nique which allows simultaneous detection of myoepithelial marker protein and cancerous HER2 gene is feasible, and it has potential to be used in clinical practice for effective determination of HER2 ampli- fication in limited invasive component.
文摘The heteroligand complex of manganese with 1,10-phenantroline and o-nitrobenzolazosalicylic acid has been investigated by spectrophotometric method. The condition of complexing and extraction, physical-chemical and analytical characteristics of this complex have been found. Complex formation is observed in the pH range 5 - 11. Extraction constant was found as 5.3 × 1012, stability constant was found as lgβK = 9.03?± 0.03. Molar absorptivity is ε = (1.36 ± 0.08) × 104 l·g﹣1·cm﹣1. Beer's law is obeyed in the range of 1.0 - 22.5 μkg manganese (II). The extraction-photometric methods of manganese determination have been worked out. The influence of diverse ions on determination of manganese (II) has been studied. The proposed method was applied successfully to determine amount of manganese in tap water.
文摘A diester-calix[4]crown-4-ether bearing mono (azophenol) moiety shows a larger spectral change toward Ca2+ than other alkali and alkaline eafth cations.
基金the National Natural Science Foundation of China(Nos.21476072,91334203)for supporting this work
文摘The traditional surfactant sodium dodecyl sulfate（SDS） and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate（[Emim][BF4]） have been combined to create a novel efficient medium for chromogenic catalysis of 3,30,5,50-tetramethylbenzidine with horseradish peroxidase in presence of H2O2. The results have shown the [Emim][BF4] in the mediums can promote the rate of formation of the blue chromogen,the SDS is responsible for the stabilization of the blue chromogen due to the electrostatic attraction between positively charged blue chromogen and the negatively charged surfactant. The SDS/[Emim][BF4]combination not only enhance catalytic activity of HRP remarkably but also stabilize the blue chromogen formed in the HRP oxidation of the substrate TMB compared to the conventional medium. Based on the superior combination of SDS and [Emim][BF4], the colorimetric assay for detecting HRP activity and H2O2 concentration was established. This work demonstrates a novel efficient medium for chromogenic catalysis with potential applications in biosensors and clinical diagnosis.
基金Supported by the National Natural Science Foundation of China (No.31272692,No.30800847)
文摘[Objective]Staphylococcus arthritis became an increasingly significant health problem in intensive chicken farming in China.[Method]In this study,a bacteria strain was isolated from the broiler chicken suffering from arthritis and named as the strain Gg1.[Result]It was then identified as Staphylococcus chromogenes by the biochemical tests and phylogenetic tree analysis based on 16S rDNA sequence.Furthermore,the catalase（katA）gene was amplified by PCR using the designed primers,and the expected fragment was 1 232 bp long encoding a protein of 410 amino acids that shares the conserved motifs including catalase,heme-binding ligand and active center motif.Six phosphorylation sites（Ser95,Thr96,Ser241,Ser242,Thr281,Ser338）,four conserved residues（Ser95,His216,Tyr281,Asp341）and two active sites（His56,Asn129）were demonstrated by multiple sequence alignment and homology comparisons.The homology modeling of 3D structure of katA protein was done by SWISSMODEL server based on the template retrieved from the catalase（PDB：2ISA_A）of Vibrio salmonicida.The katA protein represents a four-domain globular protein,the quality and reliability of the resulting protein structure was further verified by Ramachandran plot.[Conclusion]To our knowledge,this is the first report of S.chromogenes linked to arthritis in chicken and the bioinformatic characterization of its katA gene.
基金supported by the project funded by the China Postdoctoral Science Foundation project(2019M661617)the Faculty of Engineering at the University of Nottingham through a PhD studentship awarded to Runqi Liang.
文摘Chromogenic windows enable both energy-saving and daylighting regulation.However,the human response to the luminous environment affected by them is difficult to test,since their features of dynamic change and tinting automatically.This study explores the research methods,including experimental design and statistical analysis,by literature review and an experiment demonstration.The results show that a proper size of the test room is significant to obtain desired data,and the advanced VR technologies have the potential to be applied for testing these dynamic variables.Bayesian approaches are recommended to be tried and get more accurate interference about the experimental results.
基金Agriculture and Agri-Food Canada funded this research(grant number J-002223).
文摘Background Subclinical mastitis,caused by many pathogens including Staphylococcus aureus(S.aureus)and Staphylococcus chromogenes(S.chromogenes),presents a major challenge to the dairy industry due to its associated economic losses and poor milk quality.The molecular regulatory mechanisms,including the role of small nucleolar RNAs(snoRNAs),of the host response to mastitis pathogens remain unclear.Therefore,this study investigated snoRNA expression and potential roles during subclinical mastitis.Milk somatic cells from cows with naturally occurring S.aureus(n=14)and S.chromogenes(n=3)subclinical mastitis,and healthy cows(n=4)were subjected to transcriptome sequencing and bioinformatics analyses.Results We identified 255 expressed snoRNAs including 21 differentially expressed(DE)in S.aureus-positive cows and 20 DE in S.chromogenes-positive cows.Prediction of ribosomal RNA(rRNA)modification sites found several 18S rRNA and 28S rRNA modification(pseudouridylation and 2′-O-methylation)target sites essential for ribosome function for DE snoRNAs,such as SNORA79(18S-1319,28S-3001),SNORA1(18S-1496,28S-1747),suggesting their roles in translation and immune modulation during subclinical mastitis.Correlation analysis identified DE snoRNAs-mRNAs(from the same samples)pairs with majority of the correlated mRNAs(e.g.,CXCL8,IL6R,IL2,IL1R,IL18R1,STAT3,NFKB2,MYD88,VEGFA,and CD40)having immune related functions.Functional enrichment of correlated genes of snoRNAs for S.aureus-positive group(regulation of defense/immune response,leukocyte differentiation,response to cytokine,NF-κB signaling pathway,JAK-STAT signaling pathway etc.)and S.chromogenes-positive group(e.g.,regulation of defense response,response to cytokine,regulation of immune response,NF-κB signaling pathway,TNF signaling pathway,and JAK-STAT signaling pathway)revealed involvement in immune and inflammatory processes.Some functional terms were common to both pathogens(e.g.,NF-κB,JAK-STAT signaling,immune system processes)and suggest common regulatory mechanisms used by both pathogens to contain infection.Furthermore,snoRNA-mRNA network construction identified 7 key(hub)snoRNAs each for S.aureus-positive group(SNORA66,novelsnoRNA_26_14905(also denoted as novelSnoRNA_86),SNORD107,SNORA1,SNORA63,SNORA79,SNORA76)and S.chromogenes-positive group(SNORD18,SNORA79,SNORA46,U2-19,SNORA66,SNORD37,SNORD49)that correlated with the most protein coding genes(|r|>0.9;≥30 mRNAs).Functional enrichment of correlated genes of hub snoRNAs reveals their involvement in immune related functions(75%of enriched terms)and metabolic processes(20%of enriched terms).Conclusion These data suggest potential regulatory roles for the DE snoRNAs and in particular,the 14 hub snoRNAs during subclinical mastitis.This study presents the first evidence linking snoRNAs to bovine subclinical mastitis and offers new insights into the molecular mechanisms underlying subclinical mastitis caused by S.aureus and S.chromogenes.
