Sensitive Method Research Articles

A Rasch Analysis of the Teacher Social and Emotional Learning Beliefs Scale (TSELBS) in Chinese Context

The impact of teachers’ beliefs on the implementation and effectiveness of Social and Emotional Learning (SEL) programs underscores the essential need for reliable measures of these beliefs. This study aims to explore and validate the psychometric properties of the Teacher Social and Emotional Learning Beliefs Scale (TSELBS) within the Chinese educational context, utilizing the Partial Credit Model of the Rasch family models. Through the analysis of responses from 893 Chinese teachers, our findings confirm the reliability, validity, and robust psychometric properties of the TSELBS, making it a valuable instrument for assessing educators’ SEL beliefs. Additionally, our results indicate that the TSELBS demonstrates fairness across gender, educational levels, and areas. These outcomes emphasize the critical role of culturally sensitive methods in evaluating SEL beliefs and lay a foundational step for future cross-cultural research in this domain. This contribution advances the global conversation on SEL, facilitating further studies on similar validations across diverse cultural settings.

The study of interface quality in HfO2/Si films probed by second harmonic generation

Time-dependent second harmonic generation (TD-SHG) is an emergent sensitive and non-contact method to qualitatively/quantitively characterize the semiconductor materials, which is closely related to the interfacial electric field. Here, the TD-SHG technique is used to study the interface quality of atomic layer deposited 15 nm HfO2/Si (n-type/p-type) samples, which is compared to the conventional electrical characterization method. A relation between the interface state density and the time constant extracted from TD-SHG is revealed, indicating that TD-SHG is an effective method to evaluate the interface state density. In addition, the dopant type and dopant density can be disclosed by resolving the dynamic process of TD-SHG. The scenario of interfacial electric field between the initial electric field and the laser-induced electric field is proposed to explain the time-dependent evolution of SHG signal. In conclusion, the TD-SHG is a sensitive and non-contact method as well as simple and fast to characterize the semiconductor materials, which may facilitate the semiconductor in-line testing.

A simple and sensitive high-performance liquid chromatographic method combined with fluorescence detection for bioanalysis of scopoletin in rat plasma: Application to a pharmacokinetic study.

Scopoletin, a coumarin class natural phytoalexin, is present in medicinal plants such as noni (Morinda citrifolia). It exhibits diverse pharmacological properties, including antioxidant, anti-hyperuricemic, and anti-inflammatory effects. The objective of this study was to develop a novel HPLC-fluorescence (HPLC-FL) method for the quantitative analysis of scopoletin in the plasma and to investigate its pharmacokinetics in rats. Sample preparation involved a methanol-based protein precipitation method, and chromatographic separation was conducted using a C18 column with an isocratic mobile phase composed of water and acetonitrile containing 0.1% trifluoroacetic acid. The eluent was detected using an FL detector set to optimized excitation/emission wavelengths of 337/453 nm. Method validation encompassed assessments of selectivity, linearity (1-500 ng/mL), precision, accuracy, recovery, matrix effect, and stability in accordance with the prevailing Food and Drug Administration (FDA) guidelines. The developed method was successfully applied for pharmacokineticstudy in rats. To the best of our knowledge, this study is the first application of a simple and sensitive HPLC-FL method for the quantification of scopoletin in a pharmacokinetic study. This method offers a promising alternative for preclinical pharmacokinetic investigations with appropriate modifications and validations and holds potential for clinical applications.

A new sensitive and robust method development for estimation of tolcapone and quinapril in the bulk and formulations

Tolcopone and Quinapril are anti-hypersensitive drugs and, in combined dosages, are effective in managing hypertension. The RP-HPLC method was developed using OPA and Acetonitrile in 50:50 v/v as Mobile phase and 250*4.6mm, 5µ RP-HPLC column measured with a wavelength of 240nm. The HPLC system was fixed with a flow rate of 1.0ml/min; Both drugs, TOLCO and QUINA, were successfully detected at 2.153 and 3.203 min, respectively. The validation of the method as per ICH Linearity r2 lies at 0.999, and Precision, system suitability, and selectivity RSD values are within permissible limits. The accuracy of the process was found to be 99.73 and 99.52 for TOLCO and QUINA, respectively. The LOD 0.72 and 0.3 µl/ml and LOQ 0.84 and 0.13 µl/ml. The robustness and degradation studies show that the selected method is acceptable per the Guidelines.Bottom of Form

Boronic functionalized aptamer macroarrays with dual-recognition and isothermal amplification of lipopolysaccharide detection.

Ahighly sensitive dual-recognition fluorescence amplification method is presentedfor lipopolysaccharide (LPS) detection based on boronic functionalized aptamer macroarrays with dual-recognition and isothermal amplification. The surface of the polystyrene microplate was firstly carboxylated, and then, 3-aminophenylboronic acid was conjugated to the carboxyl groups through EDC/NHS reaction, creating boronic acid groups as the capture moiety for LPS. A recognition DNA aptamer labeled with the fluorescent dye 6-FAM, which exhibits specificity towards LPS, was selected as the signal reporting moiety. By introducing primers and Klenow enzyme, the fluorescent-labeled aptamers are released from the microplate bottom, and double-stranded structures were formed via isothermal amplification. The addition of SYBR Green I, which strongly fluoresces upon binding to the double-stranded structures, enables signal amplification and detection. This detection method exhibits a linear range of 1-10,000ng/mL and has a detection limit as low as 401.93pg/mL. This analytical approach shows high selectivity and sensitivity and may serve as a universal platform in lipopolysaccharide detection.

Metagenomic Next-Generation Sequencing for the Diagnosis of Viral Infectious Uveitis and Its Mimics

ABSTRACT Purpose To investigate the value of metagenomic next-generation sequencing (mNGS) for virus detection in patients with suspected viral infectious uveitis. Methods In this retrospective, multicenter case series study, 70 patients with suspected viral infectious uveitis were recruited. All patients underwent mNGS test using intraocular fluid samples and serological screening tests for pathogens. Twelve cases also underwent a PCR panel test for herpetic viruses using intraocular fluid samples; 7 cases also underwent aqueous anti-herpetic viral IgG level tests. Results Among 70 patients with suspected viral infectious uveitis, 34 cases were female, mean age was 45.3 years with a range from 6 to 78 years; 53 cases (75.7%) were diagnosed as infectious uveitis, 17 cases (24.3%) diagnosed as non-infectious uveitis. Among 53 cases with infectious uveitis, herpetic viruses, Bartonella henselae, Toxoplasma gondii, and Treponema pallidum were detected in 43, 6, 4, and 1 case, respectively. Among 43 cases with viral infectious uveitis, herpetic virus was detected in 39 cases by mNGS, the other 4 cases showed negative results in mNGS test, but positive results in 2 cases in serological screening tests, in 1 case in PCR, and in 1 case in aqueous anti-herpetic viral IgG level test, respectively. The sensitivity, specificity, positive predictive value, negative predictive value of mNGS in detecting viruses were 90.7%, 100%, 100%, and 81.0%, respectively. Conclusions mNGS is a sensitive and valuable method to detect viruses in intraocular fluid samples, and an alternative for pathogen detection in cases with suspected viral infectious uveitis but negative test results in PCR.

Shear wave elastography characteristics of the gastrocnemius muscle in postural instability gait disorder vs tremor dominant Parkinson's disease patients.

This study explored the characteristics of muscle stiffness of lower gastrocnemius in resting and exercise states in patients with postural instability gait difficulty (PIGD) and tremor dominant (TD) Parkinson's disease patients using shear wave elastography (SWE). 75 PD patients from the Department of Parkinson's Disease Center in the Hospital from September 2021 to December 2022 were prospectively included, including 44 patients with PIGD and 31 with TD. In the same period, 40 healthy subjects matching gender and age were included as the control group. SWE was used to detect Young's modulus of both sides (right and left, R- and L-) of the lateral head of the gastrocnemius in resting (YM1) and exerciser states (YM2) in all participants and the absolute difference Young's modulus between resting and exercise state (ΔYM) was calculated. R-YM2 and R-ΔYM were the highest in the normal controls, followed by the TD group, and lowest in the PIGD group. There were no differences in L-YM2 and L-ΔYM between the PIGD group and the TD group (all p > 0.05), but they were lower than those in the normal control group (all p < 0.05). In addition, R-YM2 and R-ΔYM were negatively correlated with disease duration and UPDRS III scores in the PIGD group (all p < 0.05). R-ΔYM has the highest value in the differential diagnosis of PIGD and TD patients. The area under the receiver operating characteristic curve (ROC) curve is 0.812 (95%CI, 0.730-0.893), and the diagnostic threshold is 120.5 Kpa with a sensitivity of 63.6%, a specificity of 90.1%, a positive predictive of 80%, and a negative predictive value of 80%. Shear wave elastography is a sensitive ultrasound method for evaluating muscle strength in patients with PIGD and TD. It also provides a new biological indicator to distinguish between different phenotypes of patients with PD.

"Anees Has Measles": Storytelling and Singing to Enhance MMR Vaccination in Child Care Centers Amid Religious Hesitancy.

This study explores the enhancement of MMR vaccination rates in the deep south of Thailand through a culturally tailored intervention that incorporates storytelling and singing, aligning with local cultural and religious values. The "Anees has Measles" intervention, developed with input from community stakeholders including health workers, religious leaders, and parents, featured traditional melodies in its singing activities. The intervention comprised two main components: storytelling sessions and singing activities, both utilizing culturally resonant content and formats to effectively engage the community. Conducted from December 2019 to March 2020 across eight districts in five provinces, the study targeted children aged 18 months to 5 years in government child care centers. Results indicated a substantial increase in MMR vaccination coverage from 44.3% to 72.0% twelve months post-intervention, and further to 77.0% at 48 months post-intervention, representing a significant and sustained improvement (p < 0.001). This marked and continuous increase demonstrates the effectiveness of culturally adapted health education in areas with significant vaccine hesitancy. The findings highlight the importance of integrating culturally and religiously sensitive methods into public health strategies, significantly enhancing vaccine acceptance and coverage in diverse and conservative settings. This approach suggests a broader applicability for similar interventions in comparable contexts globally.

Quantification of Nitrite in Excipients and Chemicals: A Versatile and Highly Sensitive Method Using Headspace Gas Chromatography Coupled to Mass Spectrometry

Quantification of Nitrite in Excipients and Chemicals: A Versatile and Highly Sensitive Method Using Headspace Gas Chromatography Coupled to Mass Spectrometry

CLICK-FLISA Based on Metal-Organic Frameworks for Simultaneous Detection of Fumonisin B1 (FB1) and Zearalenone (ZEN) in Maize.

Mycotoxins are secondary products produced primarily by fungi and are pathogens of animals and cereals, not only affecting agriculture and the food industry but also causing great economic losses. The development of rapid and sensitive methods for the detection of mycotoxins in food is of great significance for livelihood issues. This study employed an amino-functionalized zirconium luminescent metal-organic framework (LOF) (i.e., UiO-66-NH2). Click chemistry was utilized to assemble UiO-66-NH2 in a controlled manner, generating LOF assemblies to serve as probes for fluorescence-linked immunoassays. The proposed fluoroimmunoassay method for Zearalenone (ZEN) and Fumonisin B1 (FB1) detection based on the UiO-66-NH2 assembled probe (CLICK-FLISA) afforded a linear response range of 1-20 μmol/L for ZEN, 20 μmol/L for FB1, and a very low detection limit (0.048-0.065 μmol/L for ZEN; 0.048-0.065 μmol/L for FB1). These satisfying results demonstrate promising applications for on-site quick testing in practical sample analysis. Moreover, the amino functionalization may also serve as a modification strategy to design luminescent sensors for other food contaminants.

Nano-immuno-conjugates inspired by hydrophilic perovskite fluorescent spheres and magnetic assisted for detection of hepatitis B surface antigen.

The rampant hepatitis B virus (HBV) seriously endangers human health, and hepatitis B surface antigen (HBsAg) is its early diagnostic marker. Therefore, it is crucial to construct a fast and highly sensitive HBsAg detection method. Based on high-efficiency magnetic separation technology and fluorescent composite material labelling technology, an accurate, fast and sensitive fluorescent immunosensing system for HBsAg detectionwas developed. Immunomagnetic beads constructed from carboxyl-functionalized Fe3O4 nanoparticles (Fe3O4-COOH) with excellent magnetic response performance were used as efficient capture carriers for HBsAg. Immunofluorescence composite microspheres constructed based on ultra-stable polystyrene-coated CsPbBr3 perovskite nanocrystals (CPB@PSAA) with high hydrophilic properties, were excellent fluorescent markers for HBsAg. Using thissensitive sandwich fluorescence sensing system a good linear relationship within the range of 0.2-15ng/mL was established between HBsAg concentrationand fluorescence intensity with alimit of detection (LOD) of 0.05ng/mL. Thesystem obtained satisfactory results when tested on real human serum samples. The magnetic-assisted fluorescence immune-sandwich sensor system has broad application prospects in biomedicine such as rapid and early diagnosis and effective prevention of infectious diseases.

Specific and Sensitive Visual Proviral DNA Detection of Major Pathogenic Avian Leukosis Virus Subgroups Using CRISPR-Associated Nuclease Cas13a.

Avian leukosis viruses (ALVs) include a group of avian retroviruses primarily associated with neoplastic diseases in poultry, commonly referred to as avian leukosis. Belonging to different subgroups based on their envelope properties, ALV subgroups A, B, and J (ALV-A, ALV-B, and ALV-J) are the most widespread in poultry populations. Early identification and removal of virus-shedding birds from infected flocks are essential for the ALVs' eradication. Therefore, the development of rapid, accurate, simple-to-use, and cost effective on-site diagnostic methods for the detection of ALV subgroups is very important. Cas13a, an RNA-guided RNA endonuclease that cleaves target single-stranded RNA, also exhibits non-specific endonuclease activity on any bystander RNA in close proximity. The distinct trans-cleavage activity of Cas13 has been exploited in the molecular diagnosis of multiple pathogens including several viruses. Here, we describe the development and application of a highly sensitive Cas13a-based molecular test for the specific detection of proviral DNA of ALV-A, B, and J subgroups. Prokaryotically expressed LwaCas13a, purified through ion exchange and size-exclusion chromatography, was combined with recombinase polymerase amplification (RPA) and T7 transcription to establish the SHERLOCK (specific high-sensitivity enzymatic reporter unlocking) molecular detection system for the detection of proviral DNA of ALV-A/B/J subgroups. This novel method that needs less sample input with a short turnaround time is based on isothermal detection at 37 °C with a color-based lateral flow readout. The detection limit of the assay for ALV-A/B/J subgroups was 50 copies with no cross reactivity with ALV-C/D/E subgroups and other avian oncogenic viruses such as reticuloendotheliosis virus (REV) and Marek's disease virus (MDV). The development and evaluation of a highly sensitive and specific visual method of detection of ALV-A/B/J nucleic acids using CRISPR-Cas13a described here will help in ALV detection in eradication programs.

Comparison of parasitological methods for the identification of soil-transmitted helminths, including Strongyloides stercoralis, in a regional reference laboratory in northwestern Argentina: An observational study

Soil-transmitted helminths (STH) are a significant public health problem in impoverished communities of tropical and subtropical areas. Improved diagnostic methods are crucial for Neglected Tropical Diseases programs, particularly for S. stercoralis, as traditional methods are inadequate. Thus, it is important to identify the most accurate and efficient methods for the diagnosis of STH. We performed a retrospective study analyzing laboratory data at the Instituto de Investigaciones de Enfermedades Tropicales from 2010 to 2019. The study included data from outpatients referred for stool analysis and public health interventions from urban and rural communities in northern Salta province, Argentina. Samples were included in this analysis if processed through sedimentation/concentration, Baermann, Harada-Mori and McMaster's, with a subgroup that also included Agar plate culture method (APC). Sensitivity was calculated against a composite reference standard. Of the 5625 samples collected, 944 qualified for this analysis, with a prevalence of 11.14% for A. lumbricoides, 8.16% for hookworm, 1.38% for T. trichiura, and 6.36% for S. stercoralis. The sedimentation/concentration method was the most sensitive for A. lumbricoides (96%), compared to the McMaster method, with a sensitivity of 62%. Similarly, for hookworms, sedimentation/concentration was more sensitive than McMaster's, Harada-Mori, and Baermann with sensitivities of 87%, 70%, 43%, and 13%, respectively. Most of these infections were of light intensity. For S. stercoralis, Baermann and sedimentation/concentration methods were the most sensitive, with 70% and 62% respectively, while Harada-Mori was the least sensitive. In a subset of 389 samples also analyzed by the APC, Baermann was more sensitive than APC for detecting S. stercoralis, and both methods were superior to Harada-Mori. Parasitological methods, mostly when used combined, offer adequate opportunities for the diagnosis of STH in clinical and public health laboratories. The incorporation of S. stercoralis into the control strategies of the World Health Organization requires rethinking the current diagnostic approach used for surveys. With sedimentation/concentration and Baermann appearing as the most sensitive methods for this species. Further studies, including implementation assessments, should help in identifying the most adequate and feasible all-STH diagnostic approach.

CD34 Chimerism Directed Donor Lymphocyte Infusion With or Without Azacitidine Results in Reduced Relapse and Superior Overall Survival When Full Donor Chimerism is Achieved in Allogeneic Stem Cell Transplant Recipients With Acute Myeloid Leukaemia/Myelodysplastic Syndrome

BackgroundRegular monitoring of CD34 donor chimerism (DC) is a highly sensitive method of predicting relapse in allogeneic stem cell transplant (alloHSCT) recipients with AML/MDS. A fall of CD34 DC below 80% is an indicator of ensuing relapse. There are limited studies assessing the efficacy of donor lymphocyte infusion (DLI) triggered by mixed CD34 DC (MDC), in addressing falling chimerism. Patients and methodsWe performed a retrospective analysis of consecutive alloHSCT patients between 2012 to 2023 who received DLI (with or without azacitidine) for CD34 MDC without morphologic relapse at the time of infusion. ResultsOf the 21 patients with follow up CD34 DC available, 14 (66.7%) achieved CD34 full donor chimerism (FDC) following DLI with or without azacitidine (dli-FDC), while 7 (33.3%) did not (dli-MDC). The 2-year cumulative incidence of relapse (CIR) was significantly lower in dli-FDC compared to dli-MDC (21.4% vs. 85.7%, P < 0.001), correlating with superior overall survival (OS; median years not reached vs. 0.67 years [95% CI, 0.58-ND], P < .001). Rates of grade II-IV acute GVHD post-DLI were 14.9%, and moderate-severe cGVHD was 42.8% in the dli-FDC group. The 5-year nonrelapse mortality (NRM) of the dli-FDC group was 7.1% following DLI. ConclusionOur study shows the restoration of CD34 FDC post-DLI is associated with reduced relapse and improved overall survival, with low NRM.

Determination of Chlorogenic Acid in Solid-Lipid Nanoparticles: Validation by UV-spectroscopy

Objective: The objective of the research was the development and validation of a simple, sensitive, accurate, robust, and precise UV-spectroscopic method for the quantitative determination of chlorogenic acid loaded in solid-lipid nanoparticles as per the guidelines of the International Conference on Harmonization. Methods: The solid-lipid nanoparticles of chlorogenic acid were prepared using the hot melt emulsification method and the high-speed homogenizer method. Glyceryl monostearate was used as a solid lipid, and Tween 80 was used as a surfactant for the preparation of chlorogenic acid-loaded solid lipid nanoparticles. The method was validated in terms of linearity, accuracy, precision, robustness, ruggedness, limit of detection, and limit of quantification. Results: The chlorogenic acid exhibited absorption maxima at the wavelength of 330 nm. The regression equation from the calibration curve was y=0.006x + 0.0193 with a correlation coefficient of 0.9989. The percentage recovery was found to be 99.92, 99.80, and 99.86, respectively (within the acceptable limit of 98-102%), which validated the accuracy of the method. Furthermore, the method exhibited precision, robustness, and ruggedness, as illustrated by a relative standard deviation (RSD) of less than 2%. The limit of detection and limit of quantification were found to be 6.97 and 21.13 μg/ml, respectively. Conclusion: It was concluded that the proposed spectrophotometer analytical method for the determination of Chlorogenic acid was found reliable, accurate, consistent, precise, accurate, and robust. Therefore, the proposed analytical technique could be an integral part of further evaluation and characterization of Chlorogenic acid-solid lipid nanoparticles.

Nitrogen–silicon Co-doped carbon dots synthesized based on lemon peel for copper (II) detection via a dynamic quenching mechanism

As a metal, copper plays an important role in biological systems. However, excessive intake can lead to toxicity and disease. Therefore, there is a need to establish accurate and sensitive methods to detect and monitor copper levels in food and the environment. Herein, nitrogen-silicon co-doped carbon dots (N,Si-CDs) were synthesized using lemon peel as the biomass precursor by one-step hydrothermal synthesis with the addition of citric acid solution and 3-aminopropyl triethoxysilane (APTES). The prepared N,Si-CDs showed excellent photobleaching resistance, brilliant fluorescence performance and good selectivity. The experiments showed that the fluorescence of N,Si-CDs decreased after the interaction of N,Si-CDs with copper ions. Further studies showed that the decrease in fluorescence intensity of the fluorescent probe due to Cu2+ was dynamic quenching. In addition, the fluorescence intensity of N,Si-CDs showed a good linear relationship with the concentration of copper ions. The linear range was 0.5 μM–250 μM, the R2 was 0.995, and the limit of detection was 0.43 μM. Finally, the method has been successfully applied to the detection of copper ions in the water environment and food, and the recoveries of 99.4%–102.1 % were obtained, which indicated that the method had a promising future.

An Innovative Vortex-Assisted Liquid-Liquid Microextraction Approach Using Deep Eutectic Solvent: Application for the Spectrofluorometric Determination of Rhodamine B in Water, Food and Cosmetic Samples.

A new green and highly sensitive method for the determination of rhodamine B (RhB) by deep eutectic solvent-based vortex-assisted liquid-liquid microextraction with fluorescence detection (DES-VALLME-FLD) was developed. The extraction efficiency of conventional solvents and different deep eutectic solvent (DES) systems composed of tetrabutylammonium bromide (TBAB) and an alcohol (hexanol, octanol, or decanol) in different ratios were compared. DFT calculations of intermolecular electrostatic and non-covalent interactions of the most stable RhB forms with DES and water explain the experimental DESs' extraction efficiency. Semiempirical PM7 computations were used to obtain Hansen solubility parameters, which supported the good solubility of the monocationic RhB form in selected DESs. The dependence of the linear calibration of microextraction into 100 µL DES was observed in the RhB calibration range from 0.2 to 10.0 µg L-1 with a correlation coefficient of R2 = 0.9991. The LOD value was calculated to be 0.023 µg L-1. The accuracy and precision of the proposed method were verified over two days with RSD values of 2.9 to 4.1% and recovery of 94.6 to 103.7%. The developed method was applied to the determination of RhB in real samples (tap water, energy drink, and lipstick).

Application of untargeted liquid chromatography-mass spectrometry to routine analysis of food using three-dimensional bucketing and machine learning

For the detection of food adulteration, sensitive and reproducible analytical methods are required. Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) is a highly sensitive method that can be used to obtain analytical fingerprints consisting of a variety of different components. Since the comparability of measurements carried out with different devices and at different times is not given, specific adulterants are usually detected in targeted analyses instead of analyzing the entire fingerprint. However, this comprehensive analysis is desirable in order to stay ahead in the race against food fraudsters, who are constantly adapting their adulterations to the latest state of the art in analytics. We have developed and optimized an approach that enables the separate processing of untargeted LC‑HRMS data obtained from different devices and at different times. We demonstrate this by the successful determination of the geographical origin of honey samples using a random forest model. We then show that this approach can be applied to develop a continuously learning classification model and our final model, based on data from 835 samples, achieves a classification accuracy of 94% for 126 test samples from 6 different countries.

Shifting Mycobacterial Serine Hydrolase Activity Visualized Using Multi-Layer In-Gel Activity Assays.

The ability of Mycobacterium tuberculosis to derive lipids from the host, store them intracellularly, and then break them down into energy requires a battery of serine hydrolases. Serine hydrolases are a large, diverse enzyme family with functional roles in dormant, active, and reactivating mycobacterial cultures. To rapidly measure substrate-dependent shifts in mycobacterial serine hydrolase activity, we combined a robust mycobacterial growth system of nitrogen limitation and variable carbon availability with nimble in-gel fluorogenic enzyme measurements. Using this methodology, we rapidly analyzed a range of ester substrates, identified multiple hydrolases concurrently, observed functional enzyme shifts, and measured global substrate preferences. Within every growth condition, mycobacterial hydrolases displayed the full, dynamic range of upregulated, downregulated, and constitutively active hydrolases independent of the ester substrate. Increasing the alkyl chain length of the ester substrate also allowed visualization of distinct hydrolase activity likely corresponding with lipases most responsible for lipid breakdown. The most robust expression of hydrolase activity was observed under the highest stress growth conditions, reflecting the induction of multiple metabolic pathways scavenging for energy to survive under this high stress. The unique hydrolases present under these high-stress conditions could represent novel drug targets for combination treatment with current front-line therapeutics. Combining diverse fluorogenic esters with in-gel activity measurements provides a rapid, customizable, and sensitive detection method for mycobacterial serine hydrolase activity.

Development of a "Signal-On" Fluorescent Aptasensor for Highly Selective and Sensitive Detection of ZEN in Cereal Products Using Nitrogen-Doped Carbon Dots Based on the Inner Filter Effect.

This study aimed to develop a novel fluorescent aptasensor for the quantitative detection of zearalenone (ZEN), addressing the limitations of conventional detection techniques in terms of speed, sensitivity, and ease of use. Nitrogen-doped carbon dots (N-CDs) were synthesized via the hydrothermal method, resulting in spherical particles with a diameter of 3.25 nm. These N-CDs demonstrated high water solubility and emitted a bright blue light at 440 nm when excited at 355 nm. The fluorescence of N-CDs was quenched by dispersed gold nanoparticles (AuNPs) through the inner filter effect, while aggregated AuNPs induced by NaCl did not affect the fluorescence of N-CDs. The aptamer could protect AuNPs from NaCl-induced aggregation, but the presence of ZEN weakened this protective effect. Based on this principle, optimal conditions for ZEN detection included 57 mM NaCl, 12.5 nM aptamer concentration, incubation of AuNPs with NaCl for 15 min in Tris-EDTA(TE) buffer, and incubation of aptamer with ZEN and NaCl for 30 min. Under these optimized conditions, the "signal-on" fluorescent aptasensor for ZEN detection showed a linear range of 0.25 to 200 ng/mL with a low detection limit of 0.0875 ng/mL. Furthermore, the developed aptasensor exhibited excellent specificity and could rapidly detect ZEN in corn flour samples or corn oil, achieving satisfactory recovery rates ranging from 84.7% to 108.6%. Therefore, this study presents an economical, convenient, sensitive, and rapid method for accurately quantifying ZEN in cereal products.