Assessing the effectiveness of inhalation therapy in patients with chronic airway diseases: A new digital measurement.

BACKGROUND: This study aimed to evaluate the effectiveness of inhalation therapy in patients with chronic airway diseases via the use of a new multiparametric inhalation assessment device. METHODS: A multiparametric inhalation evaluation device (PF810, UBREATH, Zhejiang, China) that could simulate common inhalation devices with 6 different levels (0-V) of resistance was used in this study. The device was considered suitable if the three parameters of peak inspiratory flow rate (PIFR), effective inspiratory time (EIT), and breath-hold time (BHT) after inspiration met the minimum requirements. RESULTS: A total of 4,559 tests were performed. The qualification rates of 0-V resistance gear from low to high were 3.38 % (I), 8.42 % (0), 15.31 % (II), 16.71 % (III), 20.27 % (IV), and 46.91 % (V). The COPD patients in the 3 experimental groups had the lowest percentages of isolates classified as resistant 0, III, and V, which were 5.65 %, 11.93 %, and 40.43 %, respectively. The lowest percentage was 39.67 % (V) for insufficient EIT and 18.40 % (V) for BHT less than 5 s after inspiration. The results of 149 subjects who had used the inhalation device showed that the VIE and EIT at 0 levels were significantly greater than those before training (Z= -5.651, -5.646, P < 0.001). The VIE and EIT at I-III and V significantly increased after training (all P < 0.05). CONCLUSIONS: Patients using portable inhaler devices do not always inhale with adequate flow patterns. The multiparametric inhalation assessment device may be useful in outpatient settings.

Rapid determination of 61 acid dyes in chili paste, hotpot seasoning, and bearnaise using double liquid-liquid extraction and UHPLC-Q-Orbitrap-MS.

The aims of this study were to establish a novel method for simultaneously determining 61 acid dyes in chili, hotpot seasoning, and bearnaise sauce using double liquid-liquid extraction (d-LLE) technology. A mixture of water, methanol, and dichloromethane (1:3:1, v/v/v) was used as the extraction solution, which was actively separated into aqueous and organic phases at a fixed ratio. The clean-up step was initially completed by discarding the organic phase layer, which contained abundant lipophilic compounds. Subsequently, the aqueous phase was further separated by salting out, which effectively removed interference from the highly hydrophilic compounds. As a result of these two purification steps, the matrix suppression effect was significantly reduced by a minimum of 16.9%. Finally, the extract was analyzed using an ultrahigh-performance liquid chromatography-quadrupole Orbitrap mass spectrometer (UHPLC-Q-Orbitrap-MS), and the characteristic ion fragments (SO3 - , m/z 79.9557) of the acid dyes were utilized for the preliminary qualitative analysis. The results showed that the 61 acid dyes showed a good linear relationship in the range of 0.01-0.2 µg/mL, and the limit of quantification (LOQ) was 0.01 mg/kg. The average recoveries were 74.3%-99.7%, with relative standard deviations (RSD) ≤10%. The proposed method can rapidly identify and quantify acid dyes in complex foods at a low cost, with high sensitivity and reliability.

Exploration of quality criteria for the detection of peak inspiratory flow under different resistance conditions.

BACKGROUND: At present, robust quality criteria and methods for the assessment of Peak inspiratory flow meter performance are lacking. OBJECTIVE: A standard flow-volume simulator for quality control analyses of an inhalation assessment device was utilized with different simulated resistance levels in order to propose a quality testing method and associated standard for this device type. METHODS: A standard flow-volume simulator was utilized to assess the performance of an In-Check DIAL® (Device I) and an intelligent inhalation assessment device (Device P) at a fixed volume and flow rate. Indices used to evaluate these two instruments included repeatability, accuracy, linearity, and impedance. RESULTS: Both devices exhibited good repeatability (<± 3 L/min). The difference between test results and standard simulator values for Device P was less than ± 5 L/min at resistance level R1 but higher than ± 5 L/min at resistance levels R2-5, while Device I were greater than 5 L/min at all resistance levels. The relative error for Device P was <± 10% at resistance levels R1, R2, and R4, but > 10% at resistance levels R3 and R5. The relative error values for Device I at all five resistance levels were > 10%. Device P passed the linearity test at the R2 resistance level, while Device I partially passed the linearity test at all five resistance levels. CONCLUSION: Standard monitoring methods and standards provide a valuable approach to the more reliable clinical assessment and application of these instruments.

Identification and pretreatment analysis of endogenous degradation products of patulin in zebrafish.

Identification and pretreatment analysis of endogenous metabolites of patulin (PAT) in zebrafish were successfully carried out using UHPLC-Q-Orbitrap-HRMS. Three major metabolites, namely hydroascladiol, E-ascladiol, and Z-ascladiol, were identified. They exhibited similar fragmentation pathways to PAT, with the structurally significant ions *b' and *c' generated through the cleavage of the side chains of *b and *c, respectively. These ions were crucial for confirming the modification site and have been confirmed as characteristic fragments for the identification of PAT metabolites. Furthermore, a pretreatment method for analyzing PAT and the three metabolites in zebrafish was proposed, using solid-phase-assisted liquid/liquid extraction (SLLE) and matrix solid-phase dispersion (MSPD) techniques. The initial purification process involved loading the aqueous phase onto a macroporous diatomaceous column, followed by elution with acetonitrile. Following this, neutral alumina powder was added to the organic phase, effectively eliminating interference from hydrophilic and lipid-soluble compounds through the optimization of this step. Due to their structural similarity, the three metabolites were semi-quantitatively analyzed using a PAT standard curve. The results demonstrated a good linear relationship in the concentration range of 0.001-0.02 µg/mL (r2 ≥ 0.999). The limit of detection for PAT and the three metabolites ranged from 0.01 to 0.03 mg/kg.

"Diminishing returns" and leaf area-biomass scaling of ferns in subtropical ecosystems.

Foliage leaves are the primary photosynthetic organ of the majority of vascular plants, and their area vs. biomass scaling relationships provide valuable insights into the capacity and investment in light interception, which is critical to plant growth and performance. The "diminishing returns" hypothesis (DRH), which is based primarily on data from gymnosperms and angiosperms, posits that leaf (lamina) area scales with leaf dry mass. on average with a scaling exponent less than 1.0. However, it remains uncertain whether DRH applies to ferns or whether ecological factors affect the scaling exponents governing fern leaf morphometrics. To address this issue, 182 individuals of 28 subtropical ferns species were studied at low, medium, and high elevations (i.e., 600 m, 900 m, and 1200 m, respectively) in Mount Wuyi National Park, Jiangxi Province, China. The scaling relationships between leaf area and leaf biomass for individual and total leaf of ferns at different elevations were examined by using standardized major axis regression protocols. Analyses of the 28 fern species (using Blomberg K-value protocols) indicated no phylogenetic biases among the species compositions of the three different elevations. In addition, at the individual plant level, individual leaf area (ILA) did not differ significantly among the three different elevations (P > 0.05). However, individual leaf mass (ILM) was significantly higher at 900m than at 1200m (P < 0.05), resulting in a significantly higher leaf mass per area (LMA) at the 900m elevation than at the 600m and 1200m elevations (P < 0.05). The ILA and ILM at the 900m elevation were significantly higher than at the 600m elevation (P < 0.05). At the species level, ILA and ILM did not differ significantly among the three elevations (P > 0.05). The total leaf area per individual (TLA) did not differ significantly across the different elevations (P > 0.05). However, total leaf mass per individual (TLM) did differ significantly (P < 0.05). At the individual plant level, the scaling exponents for ILA vs. ILM and TLA vs. TLM at the three different elevations were all significantly less than 1.0 (P < 0.05), which was consistent with the DRH. At the species level, the scaling exponents for the ILA vs. ILM were significantly less than 1.0 at the middle and high elevations, but not at the low elevation. The scaling exponents of the TLA and TLM were numerically highest in the middle elevation, and all were less than 1.0 for the three elevations. These results indicate that the scaling relationships of leaf area versus mass of subtropical ferns at different elevations support the DRH hypothesis. The study further informs our understanding of the resource allocation strategies of an ancient and diverse plant lineage.

Predicting the Risk of Incorrect Inhalation Technique in Patients with Chronic Airway Diseases by a New Predictive Nomogram.

Purpose: To develop and internally validate a nomogram for predicting the risk of incorrect inhalation techniques in patients with chronic airway diseases. Methods: A total of 206 patients with chronic airway diseases treated with inhaled medications were recruited in this study. Patients were divided into correct (n=129) and incorrect (n=77) cohorts based on their mastery of inhalation devices, which were assessed by medical professionals. Data were collected on the basis of questionnaires and medical records. The least absolute shrinkage and selection operator method (LASSO) and multivariate logistic regression analyses were conducted to identify the risk factors of incorrect inhalation techniques. Then, calibration curve, Harrell's C-index, area under the receiver operating characteristic curve (AUC), decision curve analysis (DCA) and bootstrapping validation were applied to assess the apparent performance, clinical validity and internal validation of the predicting model, respectively. Results: Seven risk factors including age, education level, drug cognition, self-evaluation of curative effect, inhalation device use instruction before treatment, post-instruction evaluation and evaluation at return visit were finally determined as the predictors of the nomogram prediction model. The ROC curve obtained by this model showed that the AUC was 0.814, with a sensitivity of 0.78 and specificity of 0.75. In addition, the C-index was 0.814, with a Z value of 10.31 (P<0.001). It was confirmed to be 0.783 by bootstrapping validation, indicating that the model had good discrimination and calibration. Furthermore, analysis of DCA showed that the nomogram had good clinical validity. Conclusion: The application of the developed nomogram to predict the risk of incorrect inhalation techniques during follow-up visits is feasible.

HRCT quantitative analysis of airway remodeling and airway trapping in the small airway asthma phenotype and its correlation with pulmonary function.

OBJECTIVES: We aimed to explore whether large airway remodeling and small airway structural changes exist in subjects with small airway asthma phenotype and to evaluate the relationships between quantitative high-resolution computed tomography (qHRCT) parameters and lung function. METHODS: We enrolled 15 subjects with small airway asthma phenotype and 18 healthy controls. The two groups were matched by age, sex and body square area (BSA) with propensity score matching (PSM). Pulmonary function and qHRCT parameters [wall thickness (WT), wall area (WA), lumen area (LA), wall area percentage (WA%) of the 4th-6th generations in the right upper lobe apical segmental bronchus (RB1), adjusted by BSA, WT/BSA, WA/BSA, and LA/BSA, relative volume change -860 HU to -950 HU (RVC-860 to -950) and the expiration to inspiration ratio of mean lung density (MLDE/I)) were compared between the groups. Correlation analysis was employed to assess the relationship between qHRCT parameters and pulmonary function. RESULTS: The small airway asthma phenotype had significantly higher WA%, RVC-860 to -950 and MLDE/I and lower LA/BSA than the healthy control. Additionally, we found moderate to strong correlations between impulse oscillation (IOS) indices and WA6% and WT6/BSA. No significant correlation was found between bronchial parameters and air trapping parameters (p > 0.05). CONCLUSIONS: Combining physiological tests with imaging approaches can lead to better evaluation of small airway disfunction (SAD) in asthmatic patients. Additionally, despite nonexistent airflow obstruction in patients with small airway asthma phenotype, large airway remodeling and small airway structural changes may appear simultaneously in the early stage of disease.

Nardosinone and aurantio-obtusin, two medicine food homology natural compounds, are anti-influenza agents as indicated by transcriptome signature reversion.

BACKGROUND: Medicine food homology (MFH) refers to food that can be used as medicine, and compounds isolated from MFH materials are valuable in novel drug discovery due to their good safety. Transcriptome signature reversion (TSR) is an attractive method for discovering drugs through transcriptional reverse matching; namely, the changes in transcriptional signatures induced by compounds are matched to a certain disease. This strategy can be used to discover anti-influenza agents among MFH natural compounds. PURPOSE: MFH natural compounds with anti-influenza activities were identified through analyses of the reversal in the expression of multiple informative genes followed by in vitro evaluation of the cytopathic effect (CPE) caused by influenza infection and relative quantification of the nucleoprotein (NP) gene in viral RNA (vRNA). The combined effect of active compounds was determined through network-based separation score prediction followed by quantification of the viral hemagglutinin (HA) level. METHODS: The transcriptome profiles of 4 lung or airway cell lines infected with 7 influenza virus strains were analyzed by robust rank aggregation (RRA) to identify informative genes in the signature of influenza virus infection. The identified informative genes were then matched to a transcriptomic profile library of MFH natural compounds. The anti-influenza activities of MFH natural compounds with negative enrichment scores (ESs) were evaluated in vitro using a CPE assay and relative quantification of the NP gene in the vRNA in the supernatant and cytoplasm to identify anti-influenza agents. The effects of combinations of active compounds were analyzed using network-based calculations followed by confirmation through bioassays for quantifying the viral HA levels. RESULTS: Among the 159 MFH natural compounds, 54 compounds had negative ESs, as determined through TSR, and the anti-influenza activities of nardosinone and aurantio-obtusin were confirmed by bioassays. The half-maximal effective concentrations (EC50) of nardosinone and aurantio-obtusin were 4.3-84.4 µM and 31.9-113.6 µM, respectively. The separation score between the informative genes with expression that was negatively regulated by nardosinone and aurantio-obtusin in the human protein-protein interaction (PPI) network was calculated to be 0.10, which indicated that the two compounds potentially exert a synergistic effect, and this effect was confirmed by the finding that the combination indexes (CIs) were calculated to equal 0.86 at inhibition level of 50% and 0.44 at inhibition level of 90%. CONCLUSION: The TSR analysis and in vitro evaluation identified nardosinone and aurantio-obtusin as anti-influenza agents. Their antiviral activities were exerted by reversing the expression of multiple informative genes of the host cells. The separation analysis between the informative genes that were reversely regulated by nardosinone and aurantio-obtusin indicated that their combination may exert a synergistic effect, which was confirmed in vitro.

Rapid determination of 93 banned industrial dyes in beverage, fish, cookie using solid-supported liquid-liquid extraction and ultrahigh-performance liquid chromatography quadrupole orbitrap high-resolution mass spectrometry.

Banned industrial dyes are composed of a large number of chemicals with diverse physical and chemical properties, making their simultaneous determination a challenging task. A one-step extraction and purification of 93 banned industrial dyes from beverage, fish and cookie sample methods was proposed by using solid supported liquid-liquid extraction (SLE). The extract was analyzed by ultrahigh-performance liquid chromatography quadrupole orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap-HRMS). The quantitative and qualitative mode adopts Q-Orbitrap-HRMS full scan MS (full scan MS1) and data-dependent MS/MS (dd-MS2) acquisition mode. The mass resolution was screened under 70,000 FWHM for full-scan MS1 and 35,000 FWHM for dd-MS2. Linearity was observed in the range of 0.01 âˆ¼ 0.5 µg/mL and the limits of quantification were 0.04 âˆ¼ 0.2 mg/kg for 93 dyes. The average recoveries were 70.5-105.8%, with RSD ≤ 10%. The proposed method has the ability to simultaneously screen many banned dyes in foods with high throughput, sensitivity and reliability.

Hybrid silica material as a mixed-mode sorbent for solid-phase extraction of hydrophobic and hydrophilic illegal additives from food samples.

In the current study, a novel kind of mixed-mode hydrophobic/hydrophilic hybrid silica material has been developed for the solid-phase extraction of hydrophobic and hydrophilic illegal additives from food samples. A hydrophobic hybrid silica material was first prepared by the sol-gel method with tetraethoxysilane, 3-aminopropyltriethoxysilane, and dimethyloctadecyl-[3-(trimethoxysilyl)propyl] ammonium chloride (DTSACl) as precursors. Subsequently, the hydrophobic hybrid silica material was activated by glutaraldehyde, followed by the covalent immobilization of polyethyleneimine (PEI). PEI and the octadecyl group of DTSACl produced the hydrophilic/hydrophobic features of the hybrid silica material. The developed material was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance, zeta potential analyzer, and laser diffraction particle size analyzer, then applied as a hydrophobic and hydrophilic sorbent for the solid-phase extraction (SPE) of benzodiazepines from ginseng amino acid oral liquid as well as melamine and cyromazine from powdered milk, followed by RPLC/HILIC-MS/MS analysis. The composition and volumes for SPE loading and elution solutions were optimized in detail. Coupled with RPLC/HILIC-MS/MS, the proposed method provided satisfactory linearity in the range from 0.9-3.2 µg kg-1 to 100-250 µg kg-1 with the coefficients of determination higher than 0.99. The limits of detection ranged from 0.3 to 1.0 µg kg-1, and the recoveries ranged from 81.1% to 109.0% with the relative standard deviations less than 8.5% (n = 3). This report offers a new mixed-mode hydrophobic/hydrophilic hybrid silica material to extract trace hydrophobic and hydrophilic additives from complex samples.

Identification of Nifurtimox and Chrysin as Anti-Influenza Virus Agents by Clinical Transcriptome Signature Reversion.

The rapid development in the field of transcriptomics provides remarkable biomedical insights for drug discovery. In this study, a transcriptome signature reversal approach was conducted to identify the agents against influenza A virus (IAV) infection through dissecting gene expression changes in response to disease or compounds' perturbations. Two compounds, nifurtimox and chrysin, were identified by a modified Kolmogorov-Smirnov test statistic based on the transcriptional signatures from 81 IAV-infected patients and the gene expression profiles of 1309 compounds. Their activities were verified in vitro with half maximal effective concentrations (EC50s) from 9.1 to 19.1 µM against H1N1 or H3N2. It also suggested that the two compounds interfered with multiple sessions in IAV infection by reversing the expression of 28 IAV informative genes. Through network-based analysis of the 28 reversed IAV informative genes, a strong synergistic effect of the two compounds was revealed, which was confirmed in vitro. By using the transcriptome signature reversion (TSR) on clinical datasets, this study provides an efficient scheme for the discovery of drugs targeting multiple host factors regarding clinical signs and symptoms, which may also confer an opportunity for decelerating drug-resistant variant emergence.

Polyethyleneimine-functionalized Fe3O4/attapulgite particles for hydrophilic interaction-based magnetic dispersive solid-phase extraction of fluoroquinolones in chicken muscle.

Fluoroquinolone (FQ) residues in foods of animal origin may threaten public health but are challenging to determine because of their low contents and complex matrices. In this study, novel polyethyleneimine-functionalized Fe3O4/attapulgite magnetic particles were prepared by a simple co-mixing method and applied as hydrophilic sorbents for the magnetic dispersive solid-phase extraction (MSPE) of three FQs, i.e., ciprofloxacin, norfloxacin, and enrofloxacin, from chicken muscle samples. The preparation of the magnetic particles was of high reproducibility and the products could be reused many times with high adsorption capacity. The key experimental factors possibly influencing the extraction efficiencies, including sample solution, extraction time, sample loading volume, desorption solution, desorption time, and elution volume were investigated. Under optimum MSPE conditions, the analytes in chicken muscle samples were extracted and then determined by RPLC-MS/MS in MRM mode. Good linearity was obtained for the analytes with correlation coefficients ranged from 0.9975 to 0.9995. The limits of detection were in the range of 0.02-0.08 µg kg-1, and the recoveries of the spiked FQs in chicken muscle samples ranged from 83.9 to 98.7% with relative standard deviations of 1.3-6.8% (n = 3). Compared with the traditional MSPE methods based on hydrophobic mechanism, this hydrophilic interaction-based method significantly simplifies the sample pretreatment procedure and improves repeatability. This method is promising for accurate monitoring of FQs in foods of animal origin.

Novel synthesized attapulgite nanoparticles-based hydrophobic monolithic column for in-tube solid-phase microextraction of thiosildenafil, pseudovardenafil, and norneosildenafil in functional foods.

In this study, a novel method which involved in-tube solid-phase microextraction (SPME) using an attapulgite (ATP) nanoparticles-based hydrophobic monolithic column was successfully developed. It was coupled with high-performance liquid chromatography-ultraviolet detection for the determination of three phosphodiesterase-5 (PDE-5) inhibitors, including thiosildenafil, pseudovardenafil, and norneosildenafil, in functional foods. The monolithic column was prepared by one-step polymerization, using 3-trimethoxysilylpropyl methacrylate-modified ATP nanoparticles and 1-butyl-3-vinylimidazolium bromide (VBIMBr) as the functional monomers, and ethylene glycol dimethacrylate (EDMA) as the cross-linker. The obtained poly(ATP-VBIMBr-EDMA) monolith was characterized by scanning electron microscopy equipped with energy-dispersive analysis of X-ray, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. The adsorption capacity, up to 2.00 µg/cm calculated by the Langmuir isotherm model, was about six times that of the poly(VBIMBr-EDMA) monolith. Crucial factors affecting the extraction efficiency, including sample solvent, elution solvent, flow rates of sampling loading and elution, sample loading volume, and elution volume, were investigated in details. Under the optimal in-tube SPME conditions, the proposed method showed good reproducibility with run-to-run, column-to-column, and batch-to-batch relative standard deviations less than 7.2%, and low limits of detection of 0.5-0.9 ng/mL in real samples. Thiosildenafil was detected in four types of functional foods with the contents of 1.30-4.78 µg/g. This newly proposed in-tube SPME method based on poly(ATP-VBIMBr-EDMA) monolith may provide a simple, efficient, and promising alternative to daily monitoring of PDE-5 inhibitors in functional foods.

Profiling fragments for carotenoid esters in Penaeus monodon by ultra-high-performance liquid chromatography/quadrupole-Orbitrap high-resolution mass spectrometry.

RATIONALE: The precise identification of carotenoid esters of Penaeus monodon, especially those in the carotenoid skeleton, needs to occur during mass spectrometry analysis. Detailed structural information about carotenoid esters is significant not only for the assessment of nutritional quality, but also for tracing biosynthetic precursors. METHODS: The profiling of carotenoid esters in P. monodon was elucidated using ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC/Q-Orbitrap-HRMS). The raw LC/MS data were analyzed using Exact Finder™ software. RESULTS: The structurally relevant ions, *l and *m, were considered markers of the astaxanthin monoester. Moreover, the carotenoid skeleton was unequivocally identified using the diagnostic ions *i, *j/*j' and *g/*g' generated by the carbon-carbon bond cleavage between ß-ionone ketones and conjugated polyene moieties. In total, 24 carotenoid esters were identified in P. monodon based on the fragmentation patterns discussed above. The identified carotenoid skeleton includes astaxanthin, astacene, oxidized astaxanthin and adonixanthin, which have been described for the first time. CONCLUSIONS: Characterization of the unknown carotenoid esters demonstrates the capabilities of this methodology, which is significant for enriching the carotenoid species in P. monodon.

Pleomorphic adenoma of the trachea: A case report and review of the literature.

BACKGROUND: Pleomorphic adenoma (PA) is the most common benign tumor that occurs in the salivary glands; however, tracheobronchial PA is rarely observed. To the best of our knowledge, fewer than 50 cases have been reported in the literature. We report a 49-year-old woman who had been treated for asthma for 2 years before being diagnosed with PA of the trachea. CASE SUMMARY: A 49-year-old woman was referred to our hospital due to dyspnea upon exertion and chronic cough with wheezing for 2 years. Laboratory tests showed an elevated white blood cell count, absolute neutrophil count, and percentage of neutrophils. A chest computerized tomography scan showed a well-defined, soft-tissue density lesion measuring 2.4 cm × 2.1 cm in the lower trachea. Flexible bronchoscopy revealed that nearly 90% of the tracheal lumen was obstructed. The histopathological and immunohistochemistry features suggested PA of the trachea. Furthermore, we review the characteristics of 29 patients with tracheobronchial PA over the last 30 years. CONCLUSION: Tracheobronchial PA occurs without gender predominance, mostly in the lower or upper trachea, and has a low recurrence rate. The median age at diagnosis is 48 years. The most common symptoms are cough, stridor, dyspnea, and wheezing.

[System of simultaneous extraction and cleaning of 99 veterinary drugs in food].

We established a system for the simultaneous extraction and cleaning of 99 veterinary drugs from food by ultra-performance liquid chromatography coupled with quadrupole electrostatic field-orbital trap-high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS). The system is based on the supported liquid-liquid extraction technology through one-off pretreatment, which covers the common eight categories of physical and chemical properties, and the extraction and purification of 99 different veterinary drug residues. At the same time, the one-step multi residue screening of 99 veterinary drug residues has been realized using HRMS. The results showed that the method was suitable for extraction from milk, pork, and fish. The 99 veterinary drugs showed a good linear relationship in the concentration range of 0.001-0.1 µg/mL, the limit of quantification was 0.5-20.0 µg/kg, the average recoveries were 60%-120%, and the relative standard deviations (RSDs) were not more than 15%. The pre-processing and instrumental analysis of this method have high detection efficiency, strong maneuver ability, and strong compatibility with different physical and chemical compounds. Moreover, the detection limit can meet all the objects of the test and greatly reduce the detection cost.

Biosynthesis of Polyunsaturated Fatty Acids in the Razor Clam Sinonovacula constricta: Characterization of Δ5 and Δ6 Fatty Acid Desaturases.

To investigate the endogenous long-chain polyunsaturated fatty acid (LC-PUFA) biosynthetic ability in Sinonovacula constricta, fatty acid desaturases (Fads) of this bivalve, namely, Scfad5a, Scfad5b, and Scfad6, were cloned and characterized in the current study. Meanwhile, the tissue distributions of S. constricta Fads and fatty acids (FAs) were examined. Heterologous expression in yeasts confirmed that Scfad5a and Scfad5b were both Δ5 Fads, while Scfad6 was a Δ6 Fad. However, compared with Fads in other organisms, the desaturation activities of S. constricta Fads were relatively low (especially for Scfad6), indicating an adaptation to living conditions. S. constricta Fads were expressed in all tissues examined, and particularly high expressions were found in intestine and gonad. Moreover, FAs were differently distributed among tissues, which might be correlated with their corresponding physiological roles. Taken together, the results provided an insight into LC-PUFA biosynthesis in S. constricta. Notably, Scfad6 was the first functionally characterized Δ6 Fad in marine molluscs to date.

Simultaneous solid phase extraction coupled with liquid chromatography tandem mass spectrometry and gas chromatography tandem mass spectrometry for the highly sensitive determination of 15 endocrine disrupting chemicals in seafood.

This study aimed to develop a sensitive and reliable multi-residue method for the determination of trace amounts of endocrine disrupting chemicals including five phthalate esters (PAEs), five monoalky phthalate esters (MPEs), four alkylphenols (APs) and bisphenol A (BPA) in seafood. Ultrasonic liquid extraction was selected for extraction based on acetonitrile, instead of frequently-used n-hexane, due to its lower background of PAEs. Application of solid phase extraction (SPE) with primary secondary amine (PSA, 1g/6 mL) cartridge achieved the relatively low matrix effects for MPEs and BPA in seafood. To our knowledge, it is the first study reporting about simultaneous extraction and purification of PAEs, MPEs, APs and BPA in biota samples. To obtain the maximum sensitivity, both liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography tandem mass spectrometry (GC-MS/MS) were applied for analysis. This method was validated and tested on fish, mollusk and prawn. Sufficient linearity was verified by Mandel's fitting test for the matrix-matched calibrations used in this study for MPEs, APs and BPA, between 0.5 ng/g and 200 ng/g or 400 ng/g. And correlation coefficients of all calibrations suppressed 0.99 for all analytes. Good recoveries were obtained, ranging from 60% to 127% for most compounds. The sensitivity was good with method detection limits (MDLs) of 0.015-2.2 ng/g wet weight (ww) for all compounds. Most MDLs are much lower than those in previous reports. The sensitive method was then applied on real fish, mollusk and prawn samples from the Yangtze River Delta sea area (China), and all the target compounds were detected with the maximum concentrations of PAEs, MPEs, APs and BPA up to 219.3 ng/g ww, 51.4 ng/g ww, 62.0 ng/g ww and 8.6 ng/g ww, respectively.

Multi-class method for determination of veterinary drug residues and other contaminants in infant formula by ultra performance liquid chromatography-tandem mass spectrometry.

A rapid, simple and generic analytical method which was able to simultaneously determine 220 undesirable chemical residues in infant formula had been developed. The method comprised of extraction with acetonitrile, clean-up by low temperature and water precipitation, and analysis by ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS-MS) using multiple reaction monitoring (MRM) mode. Most fat materials in acetonitrile extract were eliminated by low temperature clean-up. The water precipitation, providing a necessary and supplementary cleanup, could avoid losses of hydrophobic analytes (avermectins, ionophores). Average recoveries for spiked infant formula were in the range from 57% to 147% with associated RSD values between 1% and 28%. For over 80% of the analytes, the recoveries were between 70% and 120% with RSD values in the range of 1-15%. The limits of quantification (LOQs) were from 0.01 to 5 µg/kg, which were usually sufficient to verify the compliance of products with legal tolerances. Application of this method in routine monitoring programs would imply a drastic reduction of both effort and time.

[Determination of diflubenzuron and triflumuron residues in greasy wool by accelerated solvent extraction technique and high performance liquid chromatography].

A method for the determination of diflubenzuron and triflumuron residues in greasy wool was developed by high performance liquid chromatography (HPLC) coupled with accelerated solvent extraction (ASE). The diflubenzuron and triflumuron residues were extracted with acetonitrile saturated with n-hexane at 80 degrees C and 10.34 MPa. The extract was pretreated by a series of procedures such as freezing-lipid filtration, concentration and purification by solid-phase extraction prior to the determination with HPLC. The target analytes were separated on a Waters Atlants dC18 column (250 mm x 4.6 mm, 5 microm), gradiently eluted with acetonitrile and water as the mobile phases and detected by a photodiode array detector (DAD) at 254 nm. The linear ranges were 0.1 - 10.0 mg/L. There were good linearity between the peak areas and concentrations in the linear range for the analytes, and the correlation coefficients of diflubenzuron and triflumuron were higher than 0.9999. The limits of quantification for diflubenzuron and triflumuron were 0.05 and 0.04 mg/kg (S/N > or = 10), respectively. The method is simple, rapid, sensitive and suitable for preliminary screening of diflubenzuron and triflumuron residues in greasy wool.