Method For Quantitative Detection Research Articles

Hepatic Biotransformation of Renal Clearable Gold Nanoparticles for Noninvasive Detection of Liver Glutathione Level via Urinalysis

AbstractRenal clearable nanoparticles have been drawing much attention as they can avoid prolonged accumulation in the body by efficiently clearing through the kidneys. While much effort has been made to understand their interactions within the kidneys, it remains unclear whether their transport could be influenced by other organs, such as the liver, which plays a crucial role in metabolizing and eliminating both endogenous and exogenous substances through various biotransformation processes. Here, by utilizing renal clearable IRDye800CW conjugated gold nanocluster (800CW4‐GS18‐Au25) as a model, we found that although 800CW4‐GS18‐Au25 strongly resisted serum‐protein binding and exhibited minimal accumulation in the liver, its surface was still gradually modified by hepatic glutathione‐mediated biotransformation when passing through the liver, resulting in the dissociation of IRDye800CW from Au25 and biotransformation‐generated fingerprint message of 800CW4‐GS18‐Au25 in urine, which allowed us to facilely quantify its urinary biotransformation index (UBI) via urine chromatography analysis. Moreover, we observed the linear correlation between UBI and hepatic glutathione concentration, offering us a noninvasive method for quantitative detection of liver glutathione level through a simple urine test. Our discoveries would broaden the fundamental understanding of in vivo transport of nanoparticles and advance the development of urinary probes for noninvasive biodetection.

Visual Localization and Quantitative Detection Method for Thermal Defects in Cable Terminals of High-Speed Trains Based on a Temperature Derivative

Abstract Cable terminal defect detection plays an important role in ensuring the safe and stable operation of high-speed trains (HST). In this paper, a numerical model of the electromagnetic thermal field of overheating defects of cable terminal shielding grids and a method of detecting internal defects of cable terminals - even-order temperature derivative (EOTD) is proposed for quantitative detection of internal defective structures of vehicle-mounted cable terminals. Firstly, a numerical model of the electromagnetic thermal field of cable terminals under the condition of leakage current is constructed, through which the temperature field distribution characteristics of different defective structures are analyzed. Then, the intuitive location of the defective region is obtained by investigating the derivative characteristics of the temperature image, and the depth and intensity of the defects are quantitatively assessed by using the main side peak (MSP) distances and the MSP values extracted from the derivative curves. Finally, the simulation and experimental results achieve the identification of defect structures and the quantitative detection of defect depth and intensity, proving the effectiveness and accuracy of the proposed method.

Assessment of adverse events of the novel cardiovascular drug vericiguat: a real-world pharmacovigilance study based on FAERS

ABSTRACT Background This study aims to analyze the adverse event reports (AERs) to vericiguat using data from the Food and Drug Administration Adverse Event Reporting System (FAERS) and provide evidence for the clinical use. Methods AERs due to vericiguat from 2021Q1 to 2024Q1 identified as the primary suspect were screened, with duplicate reports subsequently eliminated. Various quantitative signal detection methods, including reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network, and multi-item gamma poisson shrinker, were then employed for data mining and analysis. Signal strength is represented by the 95% confidence interval, information component (IC), and empirical Bayesian geometric mean (EBGM). Results A total of 617 vericiguat-related AERs were identified. Strong signals were observed in 21 system organ classes. Furthermore, the most frequently reported preferred terms (PT) was hypotension (n = 86, ROR 25.92, PRR 24.11, IC 4.59, EBGM 24.07), followed by dizziness (n = 52, ROR 6.44, PRR 6.20, IC 2.63, EBGM 6.20), malaise (n = 25, ROR 3.59, PRR 3.54, IC 1.82, EBGM 3.54), blood pressure decreased (n = 23, ROR 20.00, PRR 19.64, IC 4.29, EBGM 19.61), and anemia (n = 21, ROR 6.67, PRR 6.57, IC 2.72, EBGM 6.57). Conclusions This study extended the adverse reactions documented in the FDA instruction and provided supplementary evidence regarding the clinical safety of vericiguat.

Quantitative SERS detection of serum protein biomarkers for assessment of tumor microwave ablation outcomes

Microwave ablation (MWA) is widely applied in the treatment of cancer, especially hepatocellular carcinoma (HCC). However, the lack of indicators for evaluating ablation completeness limits the success rate and wider application of MWA. This study therefore aims to identify novel serum biomarkers for evaluating the completeness of ablation, by applying surface-enhanced Raman spectroscopy (SERS). Multiple cytokines are preliminarily identified through cell experiments, and the potential as biomarkers is evaluated using clinical serum samples from patients with HCC before and after MWA. CCL20 and EGF are identified as promising indicators of the completeness of MWA. Additionally, we develop a highly sensitive and specific quantitative detection method of CCL20 and EGF levels by fabricating a sandwich SERS nano-architecture amplification-based immunosensor. The linear detection range of this SERS platform is 0.1 pg/mL–1 ng/mL with the limit of detections (LoDs) decreasing to 0.082 pg/mL for CCL20 and 0.096 pg/mL for EGF. The remarkable consistency of the SERS immunosensor and ELISA in detecting CCL20 and EGF serum levels highlights the promising clinical utility of SERS in biomarker detection. The exceptional sensitivity of SERS in detecting CCL20 and EGF offers a potential avenue for enhancing the assessment of clinical MWA completeness, consequently leading to improved patient survival rates.

Ultrafast Visual Detection of a Trace Amount of Water by Highly Efficient Hybrid Manganese Halides.

A quantitative water detection method is urgently needed in storage facilities, space exploration, and the chemical industry. Although numerous physical techniques have been widely utilized to determine the water content, they still suffer from many disadvantages such as highly expensive special instruments, complicated analysis processes, etc. Hence, a convenient, rapid, and sensitive water analysis method is highly desirable. Herein, we developed a visual fluorescence sensing technology for water detection based on reversible PL off-on switching of organic-inorganic hybrid zero-dimensional (0D) manganese halides. In this work, a family of hybrid manganese halides were synthesized through a facile solution method, namely, [NH4(18-Crown-6)]2MnBr4, [Ca(18-Crown-6)·3H2O](18-Crown-6)MnBr4, [NH4(dibenzo-18-Crown-6)]2MnBr4, and [Ca(dibenzo-18-Crown-6)·2H2O]MnBr4. Excited by UV light, these highly crystalline manganese halides exhibit strong green light emissions from the d-d electron transition of Mn2+ with near-unity photoluminescence quantum yield and submillisecond lifetime. Benefiting from the dynamic and weak ionic bonding interactions, these 0D manganese halides display reversible water-response on/off luminescence switching but fail in any other aprotic solvents. Therefore, these 0D hybrid manganese halides can be explored as ultrafast visual fluorescence probes to detect the trace amount of water in organic solvents with multiple superiorities of rapid response time (< 2 s), ultralow detection limit (9.71 ppm), excellent repeatability, etc. The reversible water-response luminescent on/off switching also provides a binary optical gate with advanced applications in anticounterfeiting and information security, etc.

Hepatic Biotransformation of Renal Clearable Gold Nanoparticles for Noninvasive Detection of Liver Glutathione Level via Urinalysis.

Renal clearable nanoparticles havebeendrawing much attention as they can avoid prolonged accumulation in the body by efficiently clearing through the kidneys. While much effort has been made to understand their interactions within the kidneys, it remains unclear whether their transport could be influenced by other organs, such as the liver, whichplays a crucial role in metabolizing and eliminating both endogenous and exogenous substances through various biotransformation processes. Here, by utilizing renal clearable IRDye800CW conjugated gold nanocluster (800CW4-GS18-Au25) as a model, we found that although 800CW4-GS18-Au25strongly resisted serum-protein binding and exhibited minimal accumulation in the liver, its surface was still gradually modified by hepatic glutathione-mediated biotransformationwhen passing through the liver,resulting in the dissociation of IRDye800CW from Au25and biotransformation-generatedfingerprint messageof 800CW4-GS18-Au25in urine, which allowed us to facilely quantify its urinary biotransformation index (UBI) via urine chromatography analysis. Moreover, we observed the linear correlation between UBI and hepatic glutathione concentration,offering us a noninvasive method forquantitative detection of liver glutathione level through a simple urine test. Our discoveries would broaden the fundamental understanding ofin vivotransport of nanoparticles and advance the development of urinary probes for noninvasive biodetection.

Rapid differential diagnosis of periprosthetic joint infection by microdroplet reaction on portable biochip and indicator

Periprosthetic joint infection (PJI) is a catastrophic complication after joint arthroplasty. A key step to treat PJI is accurate diagnosis. However, according to the existing guidelines, no biomarker has been used to diagnose PJI alone and autoimmune diseases such as rheumatoid arthritis (RA) often interfere with the diagnosis. Patients with PJI often still face issues such as misdiagnosis and delayed treatment after a comprehensive scoring diagnosis. Thus, a rapid quantitative detection method based on excellent biomarker is needed. Here, an all-printed photonic crystal (PC) biochip is reported. Through the fluorescence enhancement effect of the photonic crystals and the design of the hydrophilic and hydrophobic patterning structure, trace detection of lactoferrin (LTF) in a drop of viscous synovial fluid can be achieved within 10 min by the biochip. The detection limit is as low as 4.6 ng/mL. For more intuitive results, portable testing equipment is developed with indicator light displays of three colors (green = NPJI, yellow = RA, and red = PJI) to indicate the diagnosis depending on the biochip’s fluorescence intensity. Furthermore, 79 clinical synovial fluid samples are tested with PC biochips, and the PC results are in good agreement with the ELISA results. Due to the microdroplet reaction on PCs, biochips are suitable for the detection of the selected markers in the synovial fluid. The use of the three-color portable testing equipment avoids the need for professional testing devices. Overall, this strategy provides a new paradigm for the early and differential diagnoses of PJI.

Highly responsive double-shell ZnO hollow microspheres based gas sensor for acetic acid detection in vinegar

Acetic acid sensing materials for environmental and related food quality control requiring high sensitivity and selectivity, and ppb-level detection limit, remain challenging. Double-shell ZnO hollow microspheres were prepared by a surfactant assisted template method, and the resultant gas sensor showed excellent acetic acid sensing performance. The sensor response reached 116 to 100 ppm acetic acid at 270°C with a short response time of 3.2s. The relationship between acetic acid concentration and the response was established, and the detection limit reached 100 ppb. DFT theory computational results demonstrated the highest adsorption energy of the ZnO gas sensor to acetic acid among all tested gases, proving its high selectivity to acetic acid. Besides, the unique double-shell hollow structure with abundant oxygen vacancy and large surface area might be the other factors that gave rise to its excellent acetic acid gas sensing performance. Based on the gas sensor, a method for fast quantitative detection of acetic acid content in vinegar was developed. The linear relationship between sensor response and acetic acid gas concentration of vaporized white vinegar was established, and the acetic acid content in the vinegar can be quickly determined. The result proved our acetic acid sensor to be a promising candidate for practical applications.

Development of SPQC sensor based on the specific recognition of TAL-effectors for locus-specific detection of 6-methyladenine in DNA

N6-methyladenosine (6mA) plays a pivotal role in diverse biological processes, including cancer, bacterial toxin secretion, and bacterial drug resistance. However, to date there has not been a selective, sensitive, and simple method for quantitative detection of 6mA at single base resolution. Herein, we present a series piezoelectric quartz crystal (SPQC) sensor based on the specific recognition of transcription-activator-like effectors (TALEs) for locus-specific detection of 6mA. Detection sensitivity is enhanced through the use of a hybridization chain reaction (HCR) in conjunction with silver staining. The limit of detection (LOD) of the sensor was 0.63 pM and can distinguish single base mismatches. We demonstrate the applicability of the sensor platform by quantitating 6mA DNA at a specific site in biological matrix. The SPQC sensor presented herein offers a promising platform for in-depth study of cancer, bacterial toxin secretion, and bacterial drug resistance.

Human tau N-terminal domain-specific monoclonal antibodies: screening and application in blood detection

The antibodies to the microtubule-associated protein tau play a role in basic and clinical studies of Alzheimer's disease (AD) and other tauopathies. With the recombinant human tau441 as the immunogen, the hybridoma cell strains secreting the anti-human tau N-terminal domain (NTD-tau) monoclonal antibodies were generated by cell fusion and screened by limiting dilution. The purified monoclonal antibodies were obtained by inducing the mouse ascites and affinity chromatography. The sensitivity and specificity of the monoclonal antibodies were examined by indirect ELISA and Western blotting, respectively. A double antibody sandwich ELISA method for detecting human tau protein was established and optimized. The results showed that the positive cloning rate of hybridoma cells was 83.6%. A stable cell line producing ZD8F7 antibodies was established, and the antibody titer in the supernatant of the cell line was 1:16 000. The antibody titer in the ascitic fluid was higher than 1:256 000; and the titer of purified ZD8F7 monoclonal antibodies was higher than 1:128 000. The epitope analysis showed that the ZD8F7 antibody recognized tau21-37 amino acid in the N-terminal domain. The Western blotting results showed that the ZD8F7 antibody recognized the recombinant human tau protein of 50-70 kDa and the human tau protein of 50 kDa in the brain tissue of transgenic AD model mice (APP/PS1/tau). With ZD8F7 as a capture antibody, a quantitative detection method for human tau protein was established, which showed a linear range of 7.8-500.0 pg/mL and could identify human tau protein in the brain tissue of AD transgenic mice and human plasma but not recognize the mouse tau protein. In conclusion, the human NTD-tau-specific monoclonal antibody and the double antibody sandwich ELISA method established in this study are highly sensitive and can serve as a powerful tool for the detection of tau protein in neurodegenerative diseases.

#2388 Relevance of anti-PLA2R levels in therapy decision and prediction of therapy outcome in patients with membranous nephropathy

Abstract Background and Aims Detection of anti-phospholipase A2 receptor (PLA2R) antibodies in patients with primary membranous nephropathy (MN) supports diagnosis as well as disease monitoring. An individualised therapy approach was introduced for anti-PLA2R positive MN patients at the Radboud University Medical Center. Immunosuppressive treatment (cyclophosphamide combined with steroids) was stopped when anti-PLA2R results by indirect immunofluorescence testing (IIFT) became negative. Here, we evaluated the relevance of anti-PLA2R levels for therapeutic decisions and the outcome of MN, comparing qualitative and quantitative detection methods. Method Stored serum samples were retrieved for beginning of treatment (baseline), decision point, and follow-up. Anti-PLA2R levels were determined qualitatively by IIFT as well as quantitatively by enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (ChLIA) at baseline as well as after treatment and correlated to immunological remission and persistence. Results For an evaluation of the relevance of anti-PLA2R levels at the start of therapy, serum samples of 60 patients were available. Patients sampled at the beginning of the therapy were grouped according to tertiles of anti-PLA2R levels determined by ChLIA (n[lowest tertile] = 20, n[middle tertile] = 20, n[highest tertile] = 20). Lower anti-PLA2R levels were seen in patients with relapsing disease. Higher anti-PLA2R levels were associated with more severe proteinuria. Patients in the lowest tertile of anti-PLA2R were more likely to develop immunological remission after 8 weeks of therapy. In total, 90% vs 75% vs 45% of patients in the tertiles turned anti-PLA2R negative after being treated for 8 weeks. Moreover, in this subgroup of patients who showed immunological remission after 8 weeks of therapy, only 11% of the patients in the lowest tertile needed renewed immunosuppressive therapy, while this percentage increased in the middle and highest tertiles (11% vs 53% vs 33%, p=0.033). For the assessment of anti-PLA2R levels before and after therapy, samples at baseline and week 8 of treatment were examined. At baseline, 50/50 (100%) tested positive in IIFT and ChLIA as well as 48/50 (94%) in ELISA. After 8 weeks on treatment, immunological remission based on IIFT was found in 37/51 (73%) patients. At this point, the overall agreement compared to IIFT was 92% for ChLIA and 82% for ELISA. Yet the availability of quantitative levels provided further insight into this group of patients in whom treatment was discontinued. With ChLIA, anti-PLA2R titers &amp;gt;5 RU/mL after 8 weeks of therapy were found in 4% of IIFT negative patients with persistent remission, vs 55% of IIFT negative patients with early relapse (p=0.006). Conclusion Individualised treatment of MN patients with cyclophosphamide and steroids has been recently introduced. In this respect, the quantitative determination of anti-PLA2R levels adds further value. Of the examined quantitative methods, ChLIA demonstrated the highest agreement with IIFT. Additional studies are needed to evaluate the impact on clinical decision making and outcome.

Quantitative blood loss measurement methods for early detection of primary postpartum haemorrhage following vaginal birth: A scoping review.

To map the commonly used quantitative blood loss measurement methods in clinical practice and provide a solid foundation for future studies. This study adhered to the JBI methodology for scoping reviews and preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews. We conducted a literature search using five databases to retrieve articles published between January 2012 and September 2022. The search was repeated on 29 February 2024. Data extraction and verification were carried out by two independent researchers using a self-designed data extraction form. Ultimately, 26 studies published between 2012 and 2024 were considered eligible for inclusion. Six categories of methods were identified from the 26 articles. Among the included studies, only two involved randomized controlled trials, with the majority being observational studies. The World Health Organization (2012) version of the postpartum haemorrhage diagnostic criteria was predominantly used in most studies. Gravimetric and volumetric methods emerged as the most commonly used methods for quantifying postpartum haemorrhages. The timing of blood collection was inconsistent among the included studies. Only 12 studies mentioned measures for the management of amniotic fluid. This scoping review supports the replacement of the visual estimation of blood loss with quantitative assessment methods. Supporting a specific assessment approach is not feasible due to the variability of the study. Future research should focus on establishing the best practices for specific quantitative methods to standardize the management of postpartum haemorrhage and reduce the incidence of postpartum haemorrhage-related adverse outcomes. Healthcare professionals need to acknowledge the low accuracy of visual estimation methods and implement quantitative methods to assess postpartum blood loss. Given the limitations inherent in each assessment method, quantification of blood loss should be combined with assessment of maternal vital signs, physiologic indicators and other factors.

Development of a chemiluminescence detection technique for malachite green

AbstractMalachite green (MG), a triphenylmethane dye is often used as a fungicide and preservative in fisheries due to its effectiveness against water molds in fish and fish eggs. However, excessive inhalation can be hazardous to human health. To quantify the MG concentration, we created and evaluated a 96‐well plate‐based chemiluminescence immunoassay (CLIA). This method used provided readings in &lt;30 min, with an optimal incubation time of 15 min and a limit of detection of 0.20 ng·ml−1. The strong correlation (R2 &gt;0.99) between the measured values of real fish samples examined using the method and the high‐performance liquid chromatography results confirmed the accurate quantitative detection of MG. In this study, CLIA was also used in conjunction with point‐of‐care testing (POCT) to greatly improve the efficiency of the experiments. Thus, a quantitative detection method based on MG plate chemiluminescence was established herein, with performance indexes that meet the requirements of on‐site detection. This approach is also applicable to the detection of small molecule compounds such as chloramphenicol and sulfadiazine pyrimethamine, providing a new direction in the field of food safety detection.

On-Site Quantitative Visualization of Singlet Oxygen in Crops via an Organic Small Molecule-Based Ratiometric Fluorescent Probe and a Mobile Fluorescence Analysis Device.

Singlet oxygen (1O2) plays imperative roles in a variety of biotic or abiotic stresses in crops. The change of its concentration within a crop is closely related to the crop growth and development. Accordingly, there is an urgent need to develop an efficient analytical method for on-site quantitative detection of 1O2 in crops. Here, we judiciously constructed a novel ratiometric fluorescent probe, SX-2, for the detection of 1O2 in crops. Upon treating with 1O2, probe SX-2 displayed highly selective ratiometric fluorescence response, which is favorable for the quantitative detection of 1O2. Concurrently, the fluorescence solution color of probe SX-2 was varied, obviously from blue to yellow, indicating that the probe is beneficial for on-site detection by the naked eye. Sensing reaction mechanism studies showed that the 2,3-diphenyl imidazole group in SX-2 could function as a new selective recognition group for 1O2. Probe SX-2 was utilized for the detection of photoirradiation-induced 1O2 and endogenous 1O2 in living cells. The changes in the 1O2 level in zebrafish were also tracked by fluorescence imaging. In addition, the production of 1O2 in crop leaves under a light source of different wavelengths was studied. The results demonstrated more 1O2 were produced under a light source of 365 nm. Furthermore, to achieve on-site quantitative detection, a mobile fluorescence analysis device has been made. Probe SX-2 and mobile fluorescence analysis device were capable of on-site quantitative detecting of 1O2 in crops. The method developed herein will be convenient for the on-site quantitative measurement of 1O2 in distinct crops.

Microscopic Raman-based rapid detection of submicron/nano polypropylene plastics in tea and tea beverages

Polypropylene (PP) is suitable for a broad range of applications and represents the most extensively utilized plastic in food packaging. Micro- and nano-PP plastics are prevalent categories of microplastics (MPs). However, the majority of MPs particles currently utilized in laboratory studies are man-made polystyrene (PS) spheres, and there has been limited research on micrometer- and nanoscale PP plastic particles. This study aims to employ a top-down approach in crafting micro/nanoparticle (M/NPs) models of PP particles, ensuring their enhanced relevance to real-world environments. Micro/nano PP particles, featuring a negatively charged particle size ranging from 203 to 2101 nm, were synthesized through variations in solution concentration and volume. Simultaneously, the devised MPs model was employed to develop a Raman-based qualitative and quantitative detection method for micro/nano PP particles, considering diverse sizes and concentrations. This method integrates Raman spectroscopy and microscopy to measure PP particles with varying sizes, utilizing the coffee ring effect. The Limit of detection (LOD) for 203 nm PP reached 31.25 μg/mL, while those for 382–2101 nm PP were approximately 3.9 μg/mL. The method underwent quantitative analysis by introducing 203 nm PP nanospheres into real food media (i.e., tea beverages, tea leaves), revealing a minimum LOD of approximately 31.25 μg/mL.

Pathogen identification and epidemic factor analysis of yellow catfish, Pelteobagrus fulvidraco, red lower jaw disease

Since 2020, another type of epidemic disease, ‘red lower jaw disease’ (RLJD), has broken out in yellow catfish Pelteobagrus fulvidraco every spring in China, causing large-scale deaths and significant economic losses. This new disease has the characteristics of strong infectivity, high mortality and a single host. To prevent and control RLJD, epidemiological investigation, transmission electron microscopy (TEM), virome sequencing, Koch's rule verification and epidemic factor investigation were studied in this article. The clinical symptoms of diseased yellow catfish were pale gill filaments, hyperaemia and swelling of the spleen and kidney. TEM results revealed that a large number of 35–40 nm spherical virus particles without envelope structure were found in the cytoplasm of spleen cells. The liver, spleen and kidney of the diseased fish had serious lesions. After virome sequencing, the calicivirus reads in the unique virus reads accounted for 99.5% of the unique virus reads in the diseased fish, which provided a relevant reference value for identifying the pathogen of RLJD. The full-length sequence of yellow catfish calicivirus (YCCV) obtained at 7405 bp, including the RNA-helicase domain, RdRp-1 domain and d1iqqa domain. At the same time, both PCR and TaqMan fluorescence quantitative PCR detection method of YCCV were established. Through the artificial infection test, YCCV was verified as the pathogen for RLJD. It was also found that YCCV mainly harmed the fish within 1 year, whereas the fish above 2 years had good resistance. The water temperature of the RLJD outbreak was mainly concentrated at 18 °C–24 °C. In the current study, after YCCV was verified as the pathogen of RLJD, epidemic factors including fish age and water temperature were studied, to the best of our knowledge, for the first time to provide a relevant theoretical basis for the pathogenic mechanism and prevention and control measures of yellow catfish RLJD.

Establishment of a real-time fluorescent quantitative PCR detection method and phylogenetic analysis of BoAHV-1

BackgroundInfectious bovine rhinotracheitis (IBR), caused by Bovine alphaherpesvirus-1 (BoAHV-1), is an acute, highly contagious disease primarily characterized by respiratory tract lesions in infected cattle. Due to its severe pathological damage and extensive transmission, it results in significant economic losses in the cattle industry. Accurate detection of BoAHV-1 is of paramount importance. In this study, we developed a real-time fluorescent quantitative PCR detection method for detecting BoAHV-1 infections. Utilizing this method, we tested clinical samples and successfully identified and isolated a strain of BoAHV-1.1 from positive samples. Subsequently, we conducted a genetic evolution analysis on the isolate strain’s gC, TK, gG, gD, and gE genes.ResultsThe study developed a real-time quantitative PCR detection method using SYBR Green II, achieving a detection limit of 7.8 × 101 DNA copies/μL. Specificity and repeatability analyses demonstrated no cross-reactivity with other related pathogens, highlighting excellent repeatability. Using this method, 15 out of 86 clinical nasal swab samples from cattle were found to be positive (17.44%), which was higher than the results obtained from conventional PCR detection (13.95%, 12/86). The homology analysis and phylogenetic tree analysis of the gC, TK, gG, gD, and gE genes of the isolated strain indicate that the JL5 strain shares high homology with the BoAHV-1.1 reference strains. Amino acid sequence analysis revealed that gC, gE, and gG each had two amino acid mutations, while the TK gene had one synonymous mutation and one H to Y mutation, with no amino acid mutations observed in the gD gene. Phylogenetic tree analysis indicated that the JL5 strain belongs to the BoAHV-1.1 genotype and is closely related to American strains such as C33, C14, and C28.ConclusionsThe established real-time fluorescent quantitative PCR detection method exhibits good repeatability, specificity, and sensitivity. Furthermore, genetic evolution analysis of the isolated BoAHV-1 JL-5 strain indicates that it belongs to the BoAHV-1.1 subtype. These findings provide a foundation and data for the detection, prevention, and control Infectious Bovine Rhinotracheitis.

Microfluidic chemistry assisted synthesis of cobalt quantum dot embedded nitrogen doped carbon with oxidase-like properties toward ascorbic acid detection

Ascorbic acid (AA) is a powerful antioxidant in food safety and disease treatment. It is of great significance to develop a low-cost, high-stability, and easy-to-operate colorimetric method for quantitative detection of AA in food or human body. Although various nanozymes have been developed for the colorimetric detection of AA, the size regulation of the catalytic center of nanozymes remains a challenge. In this work, we propose a combined strategy of flow chemistry synthesis and pyrolysis to realize the controllable adjustment of the catalytic center size of nanozymes. Zinc-cobalt zeolitic imidazole frameworks (ZnCo-ZIFs) with different sizes are synthesized by flow chemistry. Nitrogen-doped carbon materials with different Co catalytic centers (80 nm–10 nm) are then obtained by pyrolysis of ZnCo-ZIFs precursors. Among them, cobalt quantum dot embedded nitrogen-doped carbon (Co QDs/N-C) exhibits excellent oxidase activity, with Vmax and Km of 4.19 × 10−7 M s−1 and 0.12 mM. Therefore, a simple, low-cost, and stable colorimetric method for the detection of AA is established with a good linear relationship (3–500 μM) and low detection limit (0.40 μM). This work has certain guiding significance for the size regulation of catalytic center of nanozyme, and the detection method has broad application prospects in biochemical sensing field.

Investigation of corrosion-induced cracks using corrosion products quantified by an X-ray technique and FE analysis of single- and multiple-rebar beams

The effects of corrosion methods, galvanostatic (GS) vs. artificial climate environment (ACE), on the relationships between corrosion products and corrosion cracks of corroded reinforced concrete beams are investigated. The experimental results show that the GS method induces smaller corrosion crack width. A novel quantitative detection method of corrosion product thickness using X-ray and digital image processing techniques is proposed for investigating the continuous development of corrosion products. As the corrosion level increases, a smaller steel-to-rust volume expansion ratio caused by continuous leakage and a lower oxidation degree of corrosion products for the GS specimens are the major reasons for the smaller corrosion cracks. Regarding the effect of rebar arrangement on the development of corrosion-induced cracks, the expansion stress from corner-located rebars restrained the growth of corrosion products and further limited the propagation of corrosion-induced cracks of the center rebar. Estimated corrosion crack width via FE analysis using measured corrosion products as input show good agreement with experimental results.

Development and application of a cycleave dual-probe fluorescence quantitative PCR method for simultaneous detection of Mycoplasma gallisepticum ts-11 vaccine strain and non-ts-11 strains

An attenuated vaccine against the Mycoplasma gallisepticum ts-11 strain has become an effective prevention and control method against MG infection. However, the ts-11 strain is usually difficult to distinguish from the non-ts-11 strain (including field isolates and other vaccine strains (F and 6/85)). Therefore, it is critical to establish a rapid and effective method to distinguish ts-11 strains from non-ts-11 strains. The gene sequences of the ts-11 strain (CP044225.1) and the non-ts-11 strain (including the wild-type (CP006916.3), 6/85 (CP044224.1), and F strains (NC_017503.1) were used to construct a conserved region containing a single point mutation in the potC gene in the ts-11 strain, after which a primer-probe combination method was designed. The primer-probe method was able to accurately and efficiently identify the ts-11 and non-ts-11 strains with minimum detection limits of 2.43 copies/μL and 1.65 copies/μL, respectively. Moreover, it could simultaneously distinguish the ts-11 strain from a non-ts-11 strain, and amplifications of avian influenza virus, infectious bronchitis virus, Newcastle disease virus, fowl adenovirus, infectious laryngotracheitis virus, infectious bursal disease virus, chicken anemia virus, Marek's disease virus, Mycoplasma synoviae, and Ornithobacter rhinotracheale were negative. The detection of clinical samples revealed that the established dual-probe fluorescence quantitative PCR method could be used to screen for mixed and single infections of the ts-11 strain and non-ts-11 strains effectively, with lower variation coefficients for intra- and interbatch repetition. The established cycleave dual-probe fluorescence quantitative PCR method showed good specificity, sensitivity, and repeatability and provides powerful technical support for the rapid and efficient differential diagnosis of the MG ts-11 strain from non-ts-11 strains.