The interplay of short-term mesophyll and stomatal conductance responses under variable environmental conditions.

Understanding the short-term responses of mesophyll conductance (gm ) and stomatal conductance (gsc ) to environmental changes remains a challenging yet central aspect of plant physiology. This review synthesises our current knowledge of these short-term responses, which underpin CO2 diffusion within leaves. Recent methodological advances in measuring gm using online isotopic discrimination and chlorophyll fluorescence have improved our confidence in detecting short-term gm responses, but results need to be carefully evaluated. Environmental factors like vapour pressure deficit and CO2 concentration indirectly impact gm through gsc changes, highlighting some of the complex interactions between the two parameters. Evidence suggests that short-term responses of gm are not, or at least not fully, mechanistically linked to changes in gsc , cautioning against using gsc as a reliable proxy for gm . The overarching challenge lies in unravelling the mechanistic basis of short-term gm responses, which will contribute to the development of accurate models bridging laboratory insights with broader ecological implications. Addressing these gaps in understanding is crucial for refining predictions of gm behaviour under changing environmental conditions.

Quantitative analysis of microplastics and nanoplastics released from disposable PVC infusion tubes.

The exposure of micro- and nanoplastics (MNPs) via medical device is still unknown to us. Herein, a visual quantitative detection of polyvinyl chloride (PVC) MPs and a fluorescent quantitative detection of PVC NPs were developed. To overcome the aggregation of PVC NPs, sodium dodecylbenzene sulfonate was used as the stabilizer of PVC NPs. The brand-new disposable PVC infusion tubes were found to carry PVC MPs with the average total number (ATN) of 931.4 particles and PVC NPs with the average mass of 0.040 µg, respectively. For four typical infusion fluids such as 0.9% sodium chloride, 5% glucose, 5% sodium bicarbonate, hydroxyethyl starch 40 sodium chloride, the released PVC MPs and NPs were ranged from 1003.6 ∼ 3494.6 particles and 0.042 ∼ 0.087 µg, respectively in stimulating normal infusion scenario (room temperature 4 h). The released PVC MPs and NPs were also increased with the infusion duration and temperature. The released PVC MPs are mainly in granular form, accounting for 38 ∼ 49% of the total PVC MPs. Our findings indicate PVC MNPs can enter the blood vessel directly with the infusion fluids during intravenous infusion and the PVC MNPs exposure risk towards patients deserves more attention.

In Vivo Imaging of Tumor Hypoxia by Maintaining Green Fluorescence of 9-Aminoanthracene Under Hypoxic Conditions.

In this study, 9-aminoanthracene (9AA) was used as a new fluorescence reagent for the in vivo imaging of tumor hypoxia by taking advantage of the maintenance of its green fluorescence under hypoxic conditions. As 9AA is insoluble in water, polyethylene glycol (PEG)-400 was used to dissolve 9AA in saline. Each organ was successfully stained with 9AA, as observed by green fluorescence using in vivo imaging, following intragastric administration of a 9AA PEG-saline solution in mice. Therefore, the intragastric administration of 9AA can be used for in vivo imaging of normal mice. Tumor hypoxia staining using the 9AA fluorescence method was evaluated by in vivo imaging of mice subcutaneously transplanted with Ehrlich ascites carcinoma cells and compared with conventional pimonidazole (PIMO) staining under hypoxic conditions. The tumor sections were stained with green fluorescence derived from 9AA and the same sections corresponded to hypoxic areas upon immunohistochemical staining with PIMO.

Rolling circle transcription and CRISPR/Cas12a-assisted versatile bicyclic cascade amplification assay for sensitive uracil-DNA glycosylase detection.

Uracil-DNA glycosylase (UDG) is pivotal in maintaining genome integrity and aberrant expressed UDG is highly relevant to numerous diseases. Sensitive and accurate detecting UDG is critically significant for early clinical diagnosis. In this research, we demonstrated a sensitive UDG fluorescent assay based on rolling circle transcription (RCT)/CRISPR/Cas12a-assisted bicyclic cascade amplification strategy. Target UDG catalyzed to remove uracil base of DNA dumbbell-shape substrate probe (SubUDG) to produce an apurinic/apyrimidinic (AP) site, at which SubUDG was cleaved by apurinic/apyrimidinic endonuclease (APE1) subsequently. The exposed 5'-PO4 was ligated with the free 3'-OH terminus to form an enclosed DNA dumbbell-shape substrate probe (E-SubUDG). E-SubUDG functioned as a template can actuate T7 RNA polymerase-mediated RCT signal amplification, generating multitudes of crRNA repeats. The resultant Cas12a/crRNA/activator ternary complex activated the activity of Cas12a, causing a significantly enhanced fluorescence output. In this bicyclic cascade strategy, target UDG was amplified via RCT and CRISPR/Cas12a, and the whole reaction was completed without complex procedures. This method enabled sensitive and specific monitor UDG down to 0.0005 U/mL, screen corresponding inhibitors, and analyze endogenous UDG in A549 cells at single-cell level. Importantly, this assay can be extended to analyze other DNA glycosylase (hAAG and Fpg) by altering the recognition site in DNA substrates probe rationally, thereby offering a potent tool for DNA glycosylase-associated clinical diagnosis and biomedical research.

Application of the Fluorescence Method on Sysmex XN9000 Hematology Analyzer for Correcting Platelet Count in Individuals with Microcytosis.

OBJECTIVE: Although small red blood cells are a well-known analytical pitfall that could cause artifactual increase of the platelet count, limited information is available on the accuracy of impedance platelet counting in cases with microcytosis. The aim of this study is to assess the accuracy of impedance platelet counting in the presence of small red blood cells, and to establish the optimal mean corpuscular volume (MCV) cutoff to endorse fluorescence platelet counting. METHODS: In this study, platelet counts estimated by the impedance method on the Sysmex XN9000 analyzer (Sysmex, Kobe, Japan) were compared with those provided by the fluorescence method. The accuracy of impedance platelet counting was assessed. Receiver operating characteristic curve was used to evaluate the performance of MCV in predicting falsely increased platelet counts. RESULTS: There was a tendency for the impedance method to overestimate the platelet count in samples with 70 fL < MCV ≤ 80 fL, 60 fL < MCV ≤ 70 fL, MCV ≤ 60 fL. Receiver operating characteristic curve analysis showed that a 73.5fL cutoff of MCV was highly sensitive in predicting falsely increased platelet counts. CONCLUSION: In cases with MCV < 73.5 fL, we strongly suggest that the platelet counts obtained by the impedance method on the Sysmex XN9000 analyzer should be checked and corrected by fluorescence counting.

A simple and feasible fluorescent approach for rapid detection of hexavalent chromium based on gold nanoclusters.

Hexavalent chromium (Cr6+) owns hypertoxicity, non-biodegradability, and carcinogenicity, thus the detection of Cr6+ is of paramount significance for environmental monitoring and human health maintenance. Herein, a simple, rapid, and feasible fluorescent method based on gold nanoclusters (AuNCs) was established for determination of Cr6+. The AuNCs was coated by a simple and fast one-pot method using d-histidine (d-His) and polylysine (P-Lys) as stabilizers and reductants, which could be quenched by the addition of Cr6+ owing to the aggregation of AuNCs and fluorescence resonance energy transfer (FRET) between AuNCs and Cr6+. Under the optimal conditions, the fluorescent sensor exhibited good linearity within 10-10000 µg/L with limit of detection of 7.2 µg/L. The developed sensor possessed favorable sensitivity and selectivity. Additionally, the proposed method also had favorable recovery with good precision and accuracy within the actual sample, including celery cabbage, rice, capsule shell, and river water.

Methods for the analysis of uranium aerosol concentration in the workplace of uranium processing and fuel fabrication facilities / 中国辐射卫生

Objective To establish a method for uranium aerosol sample collection, dry ashing treatment, and laboratory laser-fluorescence measurement in the workplace of uranium processing and fuel fabrication facilities. Methods Through optimization experiments, the effects of sampling flow, sample pH value, and test temperature on uranium aerosol concentration results were studied, and the detection limit, precision, and recovery rate of the method were tested. Results Under the optimal test conditions, the detection limit of the method was 0.025 ng/mL; the minimum detectable concentration of 1 m3 of aerosol samples was 1.25 × 10−3 μg/m3; the relative standard deviation (RSD) of the measurement results was less than 5%; the recovery rate was between 96% and 104%. Conclusion The detection limit, precision, and accuracy of the method meet the testing requirements for uranium aerosol samples in the workplace of uranium processing and fuel fabrication facilities.

Effect of fluorescence method on cardiopulmonary function, immune function and safety during pulmonary segmental resection / 中国医师进修杂志

Objective:To explore the effects of fluorescence method and improved expansion and collapse method on cardiopulmonary function, immune function and safety during segmental pneumonectomy.Methods:One hundred and fifty-six patients with lung segmental resection operation in Yucheng People′s Hospital from March 2018 to August 2020 were enrolled. They were divided into two groups according to the random number table method, each group with 78 patients. The patients in the observation group were treated with fluorescence method and the patients in the control group were treated with modified expansion collapse method. The operation indexes, immune function and cardiopulmonary function of the two groups were compared, and the incidence of postoperative complications were counted.Results:The intraoperative time and the appearance time of intersegmental plane in the observation group were shorter than those in the control group: (105.33 ± 10.62) min vs. (139.46 ± 12.58) min, (15.46 ± 1.13) s vs. (724.56 ± 65.65) s, there were statistical differences ( P<0.05). After operative for 1, 7 d, the levels of 6 min walking distance, peak expiratory flow rate, percentage of forced vital capacity and percentage forced expiratory volume in 1 second in the observation group were higher than those in the control group: after operative for 1 d: (475.36 ± 10.29) m vs. (412.11 ± 13.33) m, (284.52 ± 10.33) L/min vs. (251.13 ± 12.89) L/min, (85.65 ± 3.21)% vs. (81.13 ± 1.43)%, (83.25 ± 2.55)% vs. (74.49 ± 2.53)%; after operative for 7 d: (510.23 ± 16.66) m vs. (488.33 ± 15.42) m, (302.13 ± 15.58) L/min vs. (285.12 ± 10.22) L/min, (93.46 ± 5.79)% vs. (88.44 ± 5.44)%, (92.25 ± 2.32)% vs. (85.54 ± 2.13)%, there were statistical differences ( P<0.05). After operative for 1, 7 d, the levels of CD 4+/CD 8+, CD 8+, CD 4+ in the observation group were higher than those in the control group: after operative for 1 d: 0.85 ± 0.10 vs. 0.52 ± 0.04, 0.305 ± 0.025 vs. 0.285 ± 0.012, 0.325 ± 0.021 vs. 0.304 ± 0.025; after operative for 7 d: 1.13 ± 0.10 vs. 1.02 ± 0.07, 0.324 ± 0.029 vs. 0.306 ± 0.023, 0.359 ± 0.024 vs. 0.332 ± 0.025, there were statistical differences ( P<0.05). The rate of postoperative complications in the observation group was lower than that in the control group: 2.56%(2/78) vs. 11.54%(9/78), there was statistical difference ( χ2 = 4.79; P = 0.029). Conclusions:Both the fluorescence method and the modified inflation-collapse method have certain therapeutic effects, but the combination of fluorescence method in segmentectomy can provide reliable technical support and reduce the impact on cardiopulmonary function.

Evolution of a natural dihydropteroate synthase and development of a signal amplified fluorescence method for detection of 44 sulfonamides in milk.

In this study, the recognition mechanisms and affinities of a natural dihydropteroate synthase for 44 sulfonamides were studied respectively. Then the key contact amino acid Ser222 was mutated to Arg222 by using site-directed mutagenesis method to produce a mutant. Results showed that the binding energies and affinities for the 44 drugs were generally improved. Then this mutant was used as recognition reagent to develop a direct competitive fluorescence method on 96-well microplate for determination of the 44 drugs in milk. Due to the used signal amplified fluorescent tracer, the limits of detection for the 44 drugs were in the range of 0.025-0.65 ng/mL, and the sensitivities were improved for about 6-86 folds in comparison with the conventional fluorescent tracer. After comprehensive comparison, the present method showed generally better performances than the previously reported immunoassays for sulfonamides. Therefore, this method could be used as an efficient tool for the routine screening of sulfonamides residues in large number of food samples.

A red-emitting Europium(III) complex as a luminescent probe with large Stokes shift for the sequential determination of Cu2+ and biothiols in real samples.

In this work, a novel Eu3+-DTPA-bis(AMC) complex with red luminescence was designed and synthesized for sequential detection of Cu2+ and biothiols (Cys/Hcy/GSH) based on the displacement strategy with the good selectivity, high sensitivity, and large Stokes shift (288 nm). The possible detection mechanism was verified by UV-vis, the high-resolution mass spectrometry, and the fluorescence decay curve. The experimental parameters, including the solution pH, the incubation time, the concentration ratio of Eu3+-DTPA-bis(AMC) to Cu2+ and biothiols concentration, were optimized. Under the optimal conditions, it shows a good linear relationship between the concentration (0-10 µM) of Cu2+ and the fluorescence intensity of Eu3+-DTPA-bis(AMC), with a low detection limit of 0.065 µM. The linear range and the limit of detection of the Eu3+-DTPA-bis(AMC)/Cu2+ system for Cys/Hcy/GSH were 2.5-22.5/5-45/5-50 µM and 0.11/0.07/0.05 µM, respectively. Surprisingly, the high or low concentration of Eu3+-DTPA-bis(AMC)/Cu2+ can significantly affect the selectivity of the sensing system to biothiols (Cys/GSH/Hcy). When the concentration of the Eu3+-DTPA-bis(AMC)/Cu2+ system is 10.0 µΜ, it could recognize biothiols (Cys/GSH/Hcy) from other substances, but when the concentration is as low as 3.3 µM, it could further specifically distinguished Cys from Hcy/GSH. Owing to the high anti-interference characteristics, accuracy and specificity, the sensing system was well applied to the cascade detection of Cu2+ in actual environmental samples and Cys in biological and food samples, including FBS, urine, milk, beverage, fresh juice with the satisfactory recoveries from 96.20 to 106.80 %.

Comparative Study of Algae-Based Measurements of the Toxicity of 14 Manufactured Nanomaterials.

With the increasing use of nanomaterials in recent years, determining their comparative toxicities has become a subject of intense research interest. However, the variety of test methods available for each material makes it difficult to compare toxicities. Here, an accurate and reliable method is developed to evaluate the toxicity of manufactured nanomaterials, such as Al2O3, carbon black, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), CeO2, dendrimers, fullerene, gold, iron, nanoclays, silver, SiO2, TiO2, and ZnO. A series of 72 h chronic and 8 h acute toxicity tests was performed using cell counting, chlorophyll, and delayed fluorescence methods. Comparable toxicities using the chlorophyll and delayed fluorescence methods were impossible to determine because the EC50 of some of the nanomaterials could not be measured. All three test methods were successfully applied to the chronic toxicity tests of manufactured nanomaterials, and cell counting was the only method applicable to acute toxicity tests. The toxicity data and the proposal of measurement method for manufactured nanomaterials obtained in this study can be helpful for preparing exposure standards and investigating the toxicities of other nanomaterials in the future.

Construction of a Turn-off-on Fluorescent System Based On Aggregation Induced Emission of Acetaldehyde Using Carbonized Polymer dots and Tb3.

It was the first time to report the aggregation induced emission (AIE) of acetaldehyde (AA) on the surface of carbonized polymer dots (CPDs) with the auxiliary of Tb3+. Based on the AIE of AA, a turn-off-on fluorescence method was established for AA detection using the porous CPDs-Tb3+ system. The one-pot hydrothermal method was used to obtain CPDs, using milk and polyethyleneimine (PEI) as precursors. In the presence of Tb3+, CPDs aggregated immediately and even forming precipitate, and the fluorescence intensity decreased obviously. AA can effectively embed on the surface of CPDs-Tb3+ due to the porous structure. AA displayed obviously blue fluorescence with excitation wavelength at 370 nm (emission peak at 460 nm), while there was no fluorescence peak when excited at 460 nm. In the CPDs-Tb3+ solution, AA exhibits obvious fluorescence enhancement effect (λex 460 nm, λem 545 nm). And then, AA can be determined by the turn-off-on system based on the linear relationship between fluorescence enhancement and the concentration of AA ranging from 0.04 mM to 42.48 mM. The limit of detection (LOD) was 0.02 mM. The turn-off-on system was successfully applied to determine AA in wine samples. The strategy may be exploited to monitor AA in more drinking or foodstuff samples.

[Feasibility Investigation of Fluorescence Method in Uniport Thoracoscopic Anatomical Segmentectomy for Identifying the Intersegmental Boundary Line].

BACKGROUND: Segmentectomy has gradually become one of the standard surgical methods for small pulmonary nodules with early lung cancer on imaging. This study aimed to investigate the perioperative outcomes of patients who underwent uniport video-assisted thoracoscopic surgery (VATS) segmentectomy for identifying the intersegmental boundary line (IBL) by the near-infrared fluorescence imaging with intravenous indocyanine green (ICG) method or the modified inflation-deflation (MID) method and assess the feasibility and effectiveness of the ICG fluorescence (ICGF)-based method. METHODS: We retrospectively analyzed the perioperative data in total 198 consecutive patients who underwent uniport VATS segmentectomy between February 2018 and August 2020. With the guidance of preoperative intelligent/interactive qualitative and quantitative analysis-three dimensional (IQQA-3D), the targeted segment structures could be precisely identified and dissected, and then the IBL was confirmed by ICGF-based method or MID method. Clinical effectiveness and postoperative complications of the two methods were evaluated. RESULTS: An IBL was visible in 98% of patients by the ICGF-based group, even with the low-doses of ICG. The ICGF-based group was significantly associated with the shorter IBL clear presentation time [(23.59±4.47) s vs (1,026.80±318.34) s] (P<0.01) and operative time [(89.3±31.6) min vs (112.9±33.3) min] (P<0.01), compared to the MID group. The incidence of postoperative prolonged air leaks was higher in the MID group than in the ICGF-based group (8.0% vs 26.5%, P=0.025). There were no significant differences in bleeding volume, chest tube duration, postoperative hospital stays, surgical margin width and other postoperative complications (P>0.05). CONCLUSIONS: The ICGF-based method could highly accurately identify the IBL and make anatomical segmentectomy easier and faster, and therefore has the potential to be a feasible and effective technique to facilitate the quality of uniport VATS segmentectomy.

Synthesis of molecularly imprinted microspheres and development of a fluorescence method for detection of chloramphenicol in meat.

In this study, nitrobenzene was used as dummy template to synthesize a type of specific molecularly imprinted microspheres for chloramphenicol, and 4-nitroaniline was coupled with three fluorophores to synthesize three fluorescent tracers. Then a competitive fluorescence method was developed on a conventional microplate for detection of chloramphenicol in chicken and pork samples. This method contained only one sample-loading step, so one assay was finished within 30 min. The IC50 was 1.8 ng/ml, and the limit of detection was 0.06 ng/g. The recoveries from chloramphenicol-fortified blank meat samples were in the range 67.5-96.2%. Furthermore, this method could be recycled three times. The detection results for some real meat samples were identical to that of a LC-MS/MS method. Therefore, this method could be used as a practical tool for routine screening for the residue of chloramphenicol in large number of meat samples.

Usefulness and Prospects of Sentinel Lymph Node Biopsy for Patients With Breast Cancer Using the Medical Imaging Projection System.

BACKGROUND: The Medical Imaging Projection System (MIPS) projects indocyanine green (ICG) fluorescence images directly on the surgical field using a projection mapping technique. We conducted an observational study of sentinel lymph node (SLN) biopsy using the prototype MIPS; we found a high identification rate. However, the number of SLN-positive cases was small, and the sensitivity could not be evaluated. The aim of this study was to investigate the clinical usefulness of the MIPS assisted ICG fluorescence method using commercially available equipment. METHODS: This was a retrospective observational study. Patients with primary breast cancer who underwent SLN biopsy using the MIPS at Kyoto University Hospital from April to December 2020 were included in the study. The primary endpoints were the identification rate of SLNs and detection of positive SLNs by the MIPS. The secondary endpoint was the number of SLNs excised using the MIPS per patient. We also conducted a questionnaire survey focused on the utility of the MIPS; it involved doctors with an experience in using the MIPS. RESULTS: Seventy-nine patients (84 procedures) were included in the study. In 60 (71%) procedures, both the radioisotope (RI) method and MIPS were used. At least one SLN could be detected by the MIPS in all the procedures, with an identification rate of 100% (95% confidence interval 95.6-100%). A total of 19 (7%) positive SLNs were removed, which were identifiable by the MIPS. Among 57 patients in whom the MIPS and RI methods were used, there was no positive SLN only identified by the RI method. The results of the questionnaire survey showed that the MIPS enabled the operator and assistant to share the ICG fluorescence image in the surgical field and to communicate with each other easily. CONCLUSION: The current study demonstrated that the identification rate of SLNs using the MIPS was high, and the MIPS can be used for detecting positive SLNs. It was suggested that the MIPS will be useful in learning SLN biopsy procedures.

A highly sensitive method for simultaneous detection of hAAG and UDG activity based on multifunctional dsDNA probes mediated exponential rolling circle amplification.

DNA glycosylase is an indispensable DNA damage repair enzyme which can recognize and excise the damaged bases in the DNA base excision-repair pathway. The dysregulation of DNA glycosylase activity will give rise to the dysfunction of base excision-repair and lead to abnormalities and diseases. The simultaneous detection of multiple DNA glycosylases can help to fully understand the normal physiological functions of cells, and determine whether the cells are abnormal in pre-disease. Regrettably, the synchronous detection of functionally similar DNA glycosylases is a great challenge. Herein, we developed a multifunctional dsDNA probe mediated exponential rolling circle amplification (E-RCA) method for the simultaneously sensitive detection of human alkyladenine DNA glycosylase (hAAG) and uracil-DNA glycosylase (UDG). The multifunctional dsDNA probe contains the hypoxanthine sites and the uracil sites which can be recognized by hAAG and UDG respectively to generate apyrimidinic (AP) sites in the dsDNA probe. Then the AP sites will be recognized and cut by endonuclease Ⅳ (Endo IV) to release corresponding single-stranded primer probes. Subsequently, two padlock DNA templates are added to initiate E-RCA to generate multitudinous G-quadruplexes and/or double-stranded dumbbell lock structures, which can combine N-methyl mesoporphyrin IX (NMM) and SYBR Green Ⅰ (SGI) for the generation of respective fluorescent signals. The detection limits are obtained as low as 0.0002 U mL-1 and 0.00001 U mL-1 for hAAG and UDG, respectively. Notably, this method can realize the simultaneous detection of two DNA glycosylases without the use of specially labeled probes. Finally, this method is successfully applied to detect hAAG and UDG activities in the lysates of HeLa cells and Endo1617 cells at single-cell level, and to detect the inhibitors of DNA glycosylases.

Molecular structure and evolution characteristics of dissolved organic matter in groundwater near landfill: Implications of the identification of leachate leakage.

Landfills can cause groundwater contamination, the pollution characteristics in groundwater near landfill sites have been extensively investigated, while the rapid identification of leachate leakage remained unclear. Comprehensively characterizing dissolved organic matter (DOM) is crucial for tracing the source, species, and migration of contaminants within groundwater and protecting groundwater sources. Here, we showed that DOM composition from newer landfills was mainly composed of newly-produced tryptophan and tyrosine, and protein-like and humic-like substances were more abundant in landfills that were relatively older. DOM in landfill groundwater was initially dominated by outputs from microbial activities, followed by terrigenous input. Leaked leachate contained an additional dye-derived fluorescent matter at the excitation/emission wavelength of 240-260/440-460 nm that was absent in uncontaminated groundwater. Leachate leakage increased the concentrations of humic-like substance, DOM molecular weight, and microbial activity in the downstream groundwater, resulting in the microorganisms rapidly multiply and secrete large amounts of microbial metabolism by-products, making them suitable indicators of groundwater pollution. Three criteria were proposed to establish an interpretable fluorescence method to identify leachate pollution. The obtained results provide a novel insight into not only the monitoring, early warning, and identification but also the transport, fate and removal or transformation of groundwater leachate in landfills.

Development of a molecularly imprinted microspheres-based microplate fluorescence method for detection of amantadine and rimantadine in chicken.

In this study, molecularly imprinted microspheres of a type capable of recognising amantadine and rimantadine were first synthesised, and three fluorescent tracers based on dansyl chloride, fluorescein isothiocyanate and 5-carboxytetramethylrhodamine were also synthesised. These reagents were used to develop and optimise a direct competitive fluorescence method on conventional 96-well microplate for detection of the two analytes. Results showed that this method achieved simple operation procedure, rapid assay process (30 min), high sensitivity (limits of detection 0.04-0.05 ng mL-1) and acceptable recycle performance (five times). After optimisation of several parameters, this method was used to detect amantadine and rimantadine in chicken muscle samples. Their recoveries from standards fortified blank samples were in the range of 62.3-93.7%. The analysis results for some real chicken samples were consistent with a confirmatory LC-MS/MS method. Therefore, this method could be used as a rapid, simple and accurate tool for routine screening the residues of amantadine and rimantadine in a large number of chicken muscle samples.

Rapid Detection of Clostridium botulinum in Food Using Loop-Mediated Isothermal Amplification (LAMP).

Botulinum neurotoxins are considered as one of the most potent toxins and are produced by Clostridium botulinum. It is crucial to have a rapid and sensitive method to detect the bacterium Clostridium botulinum in food. In this study, a rapid detection assay of C. botulinum in food using loop-mediated isothermal amplification (LAMP) technology was developed. The optimal primers were identified among three sets of primers designed specifically based on the partial ntnh gene encoding nontoxic-nonhaemagglutinin (NTNH) for rapid detection of the target DNA in plasmids. The optimal temperature and reaction time of the LAMP assay were determined to be 64 °C and 60 min, respectively. The chemical kit could be assembled based on these optimized reaction conditions for quick, initial high-throughput screening of C. botulinum in food samples. The established LAMP assay showed high specificity and sensitivity in detecting the target DNA with a limit of 0.0001 pg/ul (i.e., ten times more sensitive than that of the PCR method) and an accuracy rate of 100%. This study demonstrated a potentially rapid, cost-effective, and easy-operating method to detect C. botulinum in food and clinical samples based on LAMP technology.