Construction of a Novel Vanillin-Induced Autoregulating Bidirectional Transport System in a Vanillin-Producing E. coli Cell Factory.

Vanillin is one of the world's most extensively used flavoring agents with high application value. However, the yield of vanillin biosynthesis remains limited due to the low efficiency of substrate uptake and the inhibitory effect on cell growth caused by vanillin. Here, we screened high-efficiency ferulic acid importer TodX and vanillin exporters PP_0178 and PP_0179 by overexpressing genes encoding candidate transporters in a vanillin-producing engineered Escherichia coli strain VA and further constructed an autoregulatory bidirectional transport system by coexpressing TodX and PP_0178/PP_0179 with a vanillin self-inducible promoter ADH7. Compared with strain VA, strain VA-TodX-PP_0179 can efficiently transport ferulic acid across the cell membrane and convert it to vanillin, which significantly increases the substrate utilization rate efficiency (14.86%) and vanillin titer (51.07%). This study demonstrated that the autoregulatory bidirectional transport system significantly enhances the substrate uptake efficiency while alleviating the vanillin toxicity issue, providing a promising viable route for vanillin biosynthesis.

Fish oil-loaded multicore submillimeter-sized capsules prepared with monoaxial electrospraying, chitosan-tripolyphosphate ionotropic gelation, and Tween blending.

In order to load fish oil for potential encapsulation of fat-soluble functional active substances, fish oil-loaded multicore submillimeter-sized capsules were prepared with a combination method of three strategies (monoaxial electrospraying, chitosan-tripolyphosphate ionotropic gelation, and Tween blending). The chitosan-tripolyphosphate/Tween (20, 40, 60, and 80) capsules had smaller and evener fish oil cores than the chitosan-tripolyphosphate capsules, which resulted from that Tween addition induced smaller and evener fish oil droplets in the emulsions. Tween addition decreased the water contents from 56.6 % to 35.0 %-43.4 %, increased the loading capacities from 10.4 % to 12.7 %-17.2 %, and increased encapsulation efficiencies from 97.4 % to 97.8 %-99.1 %. In addition, Tween addition also decreased the highest peroxide values from 417 meq/kg oil to 173-262 meq/kg oil. These properties' changes might result from the structural differences between the chitosan-tripolyphosphate and chitosan-tripolyphosphate/Tween capsules. All the results suggested that the obtained chitosan-tripolyphosphate/Tween capsules are promising carriers for fish oil encapsulation. This work also provided useful knowledge to understand the preparation, structural, and physicochemical properties of the chitosan-tripolyphosphate capsules.

Determination of Eugenol Residues in Fish Tissue, Transport, and Temporary Water of Aquatic Product by Gas Chromatography-Tandem Mass Spectrometry with Application of the Electrospun Nanofibrous Membrane.

Using gas chromatography-tandem mass spectrometry and electrospun nanofibrous membrane, we developed and validated a simple, rapid, and sensitive methodology for quantifying eugenol residues in fish tissue and water samples. Fish tissue extract and water samples (315 samples) collected from three southeastern China provinces (Shanghai, Zhejiang, and Fujian), originating from eight provinces of Zhejiang, Jiangsu, Shandong, Guangdong, Fujian, Anhui, Shanghai, and Jiangxi, from April 2021 to April 2023 were filtered with an electrospun nanofiber membrane, extracted with trichloromethane/n-hexane, and directly concentrated to dry after simple purification. An internal standard of p-terphenyl in n-hexane and 5-µL injection volumes of the solutions was used to analyze eugenol via internal calibration with a minimum concentration of 0.5 µg/L in water samples and 0.1 µg/kg in aquatic product samples. The highest amount of eugenol was detected in Fujian province, possibly due to the higher temperature during transportation, while the lowest amount was found in Shanghai, which mainly uses temporary fish-culture devices. This is a fast, inexpensive, and effective method for testing large quantities of fish water and meat samples.

Active dark carbon fixation evidenced by 14C isotope assimilation and metagenomic data across the estuarine-coastal continuum.

Estuaries, as important land-ocean transitional zones across the Earth's surface, are hotspots of microbially driven dark carbon fixation (DCF), yet understanding of DCF process remains limited across the estuarine-coastal continuum. This study explored DCF activities and associated chemoautotrophs along the estuarine and coastal environmental gradients, using radiocarbon labelling and molecular techniques. Significantly higher DCF rates were observed at middle- and high-salinity regions (0.65-2.31 and 0.66-2.82 mmol C m-2 d-1, respectively), compared to low-salinity zone (0.07-0.19 mmol C m-2 d-1). Metagenomic analysis revealed relatively stable DCF pathways along the estuarine-coastal continuum, primarily dominated by Calvin-Benson-Bassham (CBB) cycle and Wood-Ljungdahl (WL) pathway. Nevertheless, chemoautotrophic communities driving DCF exhibited significant spatial variations. It is worth noting that although CBB cycle played an important role in DCF in estuarine sediments, WL pathway might play a more significant role, which has not been previously recognized. Overall, this study highlights that DCF activities coincide with the genetic potential of chemoautotrophy and the availability of reductive substrates across the estuarine-coastal continuum, and provides an important scientific basis for accurate quantitative assessment of global estuarine carbon sink.

Role of n-DAMO in Mitigating Methane Emissions from Intertidal Wetlands Is Regulated by Saltmarsh Vegetations.

Coastal wetlands are hotspots for methane (CH4) production, reducing their potential for global warming mitigation. Nitrite/nitrate-dependent anaerobic methane oxidation (n-DAMO) plays a crucial role in bridging carbon and nitrogen cycles, contributing significantly to CH4 consumption. However, the role of n-DAMO in reducing CH4 emissions in coastal wetlands is poorly understood. Here, the ecological functions of the n-DAMO process in different saltmarsh vegetation habitats as well as bare mudflats were quantified, and the underlying microbial mechanisms were explored. Results showed that n-DAMO rates were significantly higher in vegetated habitats (Scirpus mariqueter and Spartina alterniflora) than those in bare mudflats (P < 0.05), leading to an enhanced contribution to CH4 consumption. Compared with other habitats, the contribution of n-DAMO to the total anaerobic CH4 oxidation was significantly lower in the Phragmites australis wetland (15.0%), where the anaerobic CH4 oxidation was primarily driven by ferric iron (Fe3+). Genetic and statistical analyses suggested that the different roles of n-DAMO in various saltmarsh wetlands may be related to divergent n-DAMO microbial communities as well as environmental parameters such as sediment pH and total organic carbon. This study provides an important scientific basis for a more accurate estimation of the role of coastal wetlands in mitigating climate change.

[Comparison of fat determination methods and analysis of fatty acids in tea].

OBJECTIVE: Comparative analysis of two method for determining fat and analysis of fatty acid content in tea samples. METHODS: The content of freefatand total fat in tea was determined by Soxhlet extraction method and acid hydrolysis method, and the content of fatty acids were determined by gas chromatography. The composition and content of fatty acids in 21 tea samples from 5 regions were analyzed. RESULTS: The freefat content of tea determined by Soxhlet extraction method was significantly lower than that determined by acid hydrolysis method. The totalfat content in tea determined by acid hydrolysis method was consistent with the total amount of fatty acids determined by gas chromatography, and their content conformed to the logical relationshipsimultaneously. The totalfat content in tea ranged from 0.6 to 4.1 g/100 g, which in green tea, white tea, yellow tea, and black tea were 2.2, 1.8, 1.6 and 0.6 g/100 g, respectively. The content of free fat in tea was less than 58%, with 42%-80% of the fat existing in a bound form. The fatty acids in tea were mainly unsaturated fatty acids, accounting for 67.52%-99.03% of the total fatty acids. There were differences in the composition of fatty acids in different types of tea, with the proportion of unsaturated fatty acids in yellow tea accounting for 98.84% of the total fatty acids, which was significantly higher than that of green tea, white tea, and black tea. The fatty acids with high content in green tea(except Tang chi xiaolan tea, Bawangjian green tea and Liuxi yuye tea)were α-linoleic acid, linoleic acid, and palmitic acid. CONCLUSION: Theacid hydrolysis method is more suitable for the determination of fat in tea samples. The composition and content of fat and fatty acids in tea vary depending onfactors such as the type of tea and the degree of fermentation.

Online courses for dentist continuing education: A new trend after the COVID-19 pandemic.

Background/purpose: Online courses have been widely used in all levels of education during the COVID-19 pandemic. This study explored the effectiveness of a dentist continuing education (DCE) course through the online devices in Taiwan. Materials and methods: The practicing dentists who participated in the online course of dental radiation technology for DCE offered by the Taiwan Dental Association (TWDA) in October 2022 and in March 2023 were enrolled in this study. The composition of participating dentists was confirmed by the public inquiry system and their learning effectiveness was evaluated by a questionnaire-based survey after the online DCE class. Results: All participating dentists (132 in October 2022 and 117 in March 2023) obtained consistent good learning outcomes in this online DCE course. Of these 249 dentists, there were 170 (68.27%) males and 79 (31.73%) females, 127 (51.00%) dental specialists and 122 (49.00%) general dentists, as well as 50 (20.08%) hospital dentists and 199 (79.92%) clinic dentists. The participation rates for this course of practicing dentists in non-municipalities (4.70%), counties (3.88%), eastern region (8.08%), and outlying islands (3.60%) were much higher than those in municipalities (0.79%), cities (1.16%), and the western region including the northern region (0.88%), central region (1.96%), and southern region (1.94%), respectively. Conclusion: The participating dentists express positive feedback on the online DCE courses, and the online DCE courses can reduce the urban-rural gap in dental education resources. The use of online DCE courses in dental education will be a future trend.

HER3 functions as an effective therapeutic target in triple negative breast cancer to potentiate the antitumor activity of gefitinib and paclitaxel.

BACKGROUND: Triple negative breast cancer (TNBC) represents a significant clinical challenge. Chemotherapy remains the mainstay for a large part of TNBC patients, whereas drug resistance and tumor recurrence frequently occur. It is in urgent need to identify novel molecular targets for TNBC and develop effective therapy against the aggressive disease. METHODS: Immunohistochemistry was performed to examine the expression of HER3 in TNBC samples. Western blots were used to assess protein expression and activation. Cell proliferation and viability were determined by cell growth (MTS) assays. TCGA databases were analyzed to correlate HER3 mRNA expression with the clinical outcomes of TNBC patients. Specific shRNA was used to knockdown HER3 expression. IncuCyte system was utilized to monitor cell growth and migration. LIVE/DEAD Cell Imaging was to detect live and dead cells. HER3 recognition by our anti-HER3 monoclonal antibody (mAb) 4A7 was verified by ELISA, flow cytometry, and co-immunoprecipitation assays. Orthotopic tumor models were established in nude mice to determine the capability of TNBC cells forming tumors and to test if our mAb 4A7 could potentiate the antitumor activity of paclitaxel in vivo. RESULTS: Elevated expression of HER3 was observed in approximately half of the TNBC specimens and cell lines tested. Analyses of TCGA databases found that the TNBC patients with high HER3 mRNA expression in the tumors showed significantly worse overall survival (OS) and relapse-free survival (RFS) than those with low HER3 expression. Specific knockdown of HER3 markedly inhibited TNBC cell proliferation and mammosphere formation in vitro and tumor growth in vivo. Our mAb 4A7 abrogated heregulin (a ligand for HER3), but not SDF-1 (a ligand for CXCR4)-induced enhancement of TNBC cell migration. Combinations of 4A7 and the EGFR-tyrosine kinase inhibitor (TKI) gefitinib dramatically decreased the levels of phosphorylated HER3, EGFR, Akt, and ERK1/2 in TNBC cells and potently induced growth inhibition and cell death. Moreover, 4A7 in combination with paclitaxel exerted significant antitumor activity against TNBC in vitro and in vivo. CONCLUSIONS: Our data demonstrate that increased HER3 is an effective therapeutic target for TNBC and our anti-HER3 mAb (4A7) may enhance the efficacy of gefitinib or paclitaxel in TNBC.

Thyroid hormone enhances estrogen-mediated proliferation and cell cycle regulatory pathways in steroid receptor-positive breast Cancer.

Estrogen receptor (ER) α expression and associated signaling is a major driver of over two-thirds of all breast cancers (BC). ER targeting strategies are typically used as a first-line therapy in patients with steroid receptor positive (SR+) disease. Secondary resistance to anti-estrogenic agents may occur with clonal expansion and disease progression. Mechanisms underlying hormone resistance are an expanding field of significant translational importance. Cross-talk with other nuclear hormones, receptors, and signaling pathways, including thyroid hormones (TH) and their receptors (THRs), have been shown to promote endocrine therapy resistance in some studies. We have shown that TH replacement therapy (THRT) was independently and significantly associated with higher rates of relapse and mortality in SR positive (+), node-negative (LN-) BC patients, whereas it showed no association with outcomes in SR negative (-) patients. LN-, SR+ patients receiving THRT and tamoxifen had the worst outcomes, suggesting a pro-carcinogenic interaction that significantly and independently shortened survival and increased mortality. Using in vivo and in vitro models, we previously showed hormonal cross-talk, altered gene signaling, target gene activation, and resistance to tamoxifen in the presence of TH. In this report, we show TH ± E2 ± tamoxifen inhibits cell cycle control signaling, reduces apoptosis, and enhances cell proliferation, tumor growth, tamoxifen resistance, and clonal expansion. Mechanistically these changes involve numerous genes and pathways, including critical cell cycle regulatory proteins and genes identified using various molecular methods. These studies facilitate a greater mechanistic understanding of the biological and molecular impact of TH on SR+ BC.

HER3 targeting augments the efficacy of panobinostat in claudin-low triple-negative breast cancer cells.

Patients with triple-negative breast cancer (TNBC) have a poor prognosis and high relapse rate due to limited therapeutic options. This study was conducted to determine the mechanisms of action of panobinostat, a pan-inhibitor of histone deacetylase (HDAC) and FDA-approved medication for multiple myeloma, in TNBC and to provide a rationale for effective drug combinations against this aggressive disease. RNA sequencing analyses of the claudin-low (CL) TNBC (MDA-MB-231) cells untreated or treated with panobinostat were performed to identify the differentially expressed genes. Adaptive alterations in gene expression were analyzed and validated in additional CL TNBC cells. Tumor xenograft models were used to test the in vivo antitumor activity of panobinostat alone or its combinations with gefitinib, an EGFR-tyrosine kinase inhibitor (TKI). Panobinostat potently inhibited proliferation and induced apoptosis in all TNBC cells tested. However, in CL TNBC cells, this HDAC inhibitor markedly enhanced expression of HER3, which interacted with EGFR to activate both receptors and Akt signaling pathways. Combinations of panobinostat and gefitinib synergistically suppressed CL TNBC cell proliferation and promoted apoptosis in vitro and in vivo. Upregulation of HER3 compromises the efficacy of panobinostat in CL TNBC. Inactivation of HER3 combined with panobinostat represents a practical approach to combat CL TNBC.

Tidal dynamics regulates potential coupling of carbon­nitrogen­sulfur cycling microbes in intertidal flats.

Tide-driven hydrodynamic process causes significant geochemical gradients that influence biogeochemical cycling and ecological functioning of estuarine and coastal ecosystems. However, the effects of tidal dynamics on microbial communities, particularly at the functional gene level, remain unclear even though microorganisms play critical roles in biogeochemical carbon (C), nitrogen (N) and sulfur (S) cycling. Here, we used 16S rRNA gene amplicon sequencing and microarray-based approach to reveal the stratification of microorganisms related to C, N and S cycles along vertical redox gradients in intertidal wetlands. Alpha-diversity of bacteria and archaea was generally higher at the deep groundwater-sediment interface. Microbial compositions were markedly altered along the sediment profile, and these shifts were largely due to changes in nutrient availability and redox potential. Furthermore, functional genes exhibited redox partitioning between interfaces and transition layer, with abundant genes involved in C decomposition, methanogenesis, heterotrophic denitrification, sulfite reduction and sulfide oxidation existed in the middle anoxic zone. The influence of tidal dynamics on sediment function was highly associated with redox state, sediment texture, and substrates availability, leading to distinct distribution pattern of metabolic coupling of microbes involved in energy flux and elemental cycling in intertidal wetlands. These results indicate that tidal cycles are critical in determining microbial community and functional structure, and they provide new insights into sediment microbe-mediated biogeochemical cycling in intertidal habitats.

Trastuzumab-resistant breast cancer cells-derived tumor xenograft models exhibit distinct sensitivity to lapatinib treatment in vivo.

BACKGROUND: Resistance to HER2-targeted therapies, including the monoclonal antibody trastuzumab and tyrosine kinase inhibitor lapatinib, frequently occurs and currently represents a significant clinical challenge in the management of HER2-positive breast cancer. We previously showed that the trastuzumab-resistant SKBR3-pool2 and BT474-HR20 sublines were refractory to lapatinib in vitro as compared to the parental SKBR3 and BT474 cells, respectively. The in vivo efficacy of lapatinib against trastuzumab-resistant breast cancer remained unclear. RESULTS: In tumor xenograft models, both SKBR3-pool2- and BT474-HR20-derived tumors retained their resistance phenotype to trastuzumab; however, those tumors responded differently to the treatment with lapatinib. While lapatinib markedly suppressed growth of SKBR3-pool2-derived tumors, it slightly attenuated BT474-HR20 tumor growth. Immunohistochemistry analyses revealed that lapatinib neither affected the expression of HER3, nor altered the levels of phosphorylated HER3 and FOXO3a in vivo. Interestingly, lapatinib treatment significantly increased the levels of phosphorylated Akt and upregulated the expression of insulin receptor substrate-1 (IRS1) in the tumors-derived from BT474-HR20, but not SKBR3-pool2 cells. CONCLUSIONS: Our data indicated that SKBR3-pool2-derived tumors were highly sensitive to lapatinib treatment, whereas BT474-HR20 tumors exhibited resistance to lapatinib. It seemed that the inefficacy of lapatinib against BT474-HR20 tumors in vivo was attributed to lapatinib-induced upregulation of IRS1 and activation of Akt. Thus, the tumor xenograft models-derived from SKBR3-pool2 and BT474-HR20 cells serve as an excellent in vivo system to test the efficacy of other HER2-targeted therapies and novel agents to overcome trastuzumab resistance against HER2-positive breast cancer.

Potential response of dark carbon fixation to global warming in estuarine and coastal waters.

Dark carbon fixation (DCF), through which chemoautotrophs convert inorganic carbon to organic carbon, is recognized as a vital process of global carbon biogeochemical cycle. However, little is known about the response of DCF processes in estuarine and coastal waters to global warming. Using radiocarbon labelling method, the effects of temperature on the activity of chemoautotrophs were investigated in benthic water of the Yangtze estuarine and coastal areas. A dome-shaped thermal response pattern was observed for DCF rates (i.e., reduced rates at lower or higher temperatures), with the optimum temperature (Topt ) varying from about 21.9 to 32.0°C. Offshore sites showed lower Topt values and were more vulnerable to global warming compared with nearshore sites. Based on temperature seasonality of the study area, it was estimated that warming would accelerate DCF rate in winter and spring but inhibit DCF activity in summer and fall. However, at an annual scale, warming showed an overall promoting effect on DCF rates. Metagenomic analysis revealed that the dominant chemoautotrophic carbon fixation pathways in the nearshore area were Calvin-Benson-Bassham (CBB) cycle, while the offshore sites were co-dominated by CBB and 3-hydroxypropionate/4-hydroxybutyrate cycles, which may explain the differential temperature response of DCF along the estuarine and coastal gradients. Our findings highlight the importance of incorporating DCF thermal response into biogeochemical models to accurately estimate the carbon sink potential of estuarine and coastal ecosystems in the context of global warming.

Effectiveness and safety of implementing an enhanced patient comfort programme for elective neurosurgical patients: a randomised controlled trial protocol.

INTRODUCTION: Patient comfort is an important quality indicator of healthcare. According to Kolcaba's comfort theory, enhanced comfort is achieved by meeting the needs in four contexts: physical, psychospiritual, sociocultural and environmental. An enhanced patient comfort (EPC) programme based on this theory has been designed for elective neurosurgical patients. This study aims to assess its feasibility, effectiveness and safety. METHODS AND ANALYSIS: The EPC programme patients will be evaluated in a single institutional randomised controlled trial. A total of 110 patients admitted for elective neurosurgery (including craniotomy, endoscopic trans-sphenoidal surgery and spine surgery) will be randomised in a 1:1 ratio to two groups. Patients in the EPC group are managed under the newly developed EPC programme, which aims to enhance patient experience and includes care coordination since admission (such as appointment of a care support coordinator, personalised setting, and cultural and spiritual support), preoperative management (such as lifestyle intervention, potential psychological and sleep intervention, and prerehabilitation), intraoperative and anaesthetic management (such as nurse coaching, music playing, and pre-emptive warming), postoperative management (such as early extubation, early diet advancement, mood and sleep management, and early ambulation) and optimised discharge planning; while those in the control group receive conventional perioperative care. The primary outcome is patient satisfaction and comfort measured by the Chinese Surgical Inpatient Satisfaction and Comfort Questionnaire. The secondary outcomes include postoperative morbidity and mortality, postoperative pain score, postoperative nausea and vomiting, functional recovery status (Karnofsky performance status and Quality of Recovery-15 score), mental status (anxiety and depression), nutritional status, health-related quality of life, hospital length of stay, reoperation and readmission rates, overall cost and patient experience. ETHICS AND DISSEMINATION: Ethical approval to conduct the study has been obtained from Institutional Review Board of Xi'an International Medical Center (No. 202028). The results will be presented at scientific meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: Chinese clinical trial registry ChiCTR2000039983.

Effects of acidification on nitrification and associated nitrous oxide emission in estuarine and coastal waters.

In the context of an increasing atmospheric carbon dioxide (CO2) level, acidification of estuarine and coastal waters is greatly exacerbated by land-derived nutrient inputs, coastal upwelling, and complex biogeochemical processes. A deeper understanding of how nitrifiers respond to intensifying acidification is thus crucial to predict the response of estuarine and coastal ecosystems and their contribution to global climate change. Here, we show that acidification can significantly decrease nitrification rate but stimulate generation of byproduct nitrous oxide (N2O) in estuarine and coastal waters. By varying CO2 concentration and pH independently, an expected beneficial effect of elevated CO2 on activity of nitrifiers ("CO2-fertilization" effect) is excluded under acidification. Metatranscriptome data further demonstrate that nitrifiers could significantly up-regulate gene expressions associated with intracellular pH homeostasis to cope with acidification stress. This study highlights the molecular underpinnings of acidification effects on nitrification and associated greenhouse gas N2O emission, and helps predict the response and evolution of estuarine and coastal ecosystems under climate change and human activities.

[Simultaneous determination of seven quaternary ammonium compounds in frozen food by ultra performance liquid chromatography-tandem mass spectrometry combined with modified QuEChERS method].

Quaternary ammonium compounds (QACs) are a class of cationic surfactants that can be used as the main active ingredient of disinfectants. The increased use of QACs is concerning as exposure from inhalation or ingestion to these compounds that has been associated with adverse effects on the reproductive and respiratory systems. Humans are exposed to QACs primarily by food consumption and inhalation of air. QAC residues pose significant threats to public health. Given the importance of assessing potential residue levels for QACs in food, therefore, a method was developed for the simultaneous detection of six common QACs and one emerging QAC (Ephemora) in frozen food by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with the modified QuEChERS method. The main factors governing the response, recovery, and sensitivity of the method, including extraction solvents, types and dosages of adsorbents, apparatus conditions, and mobile phases, were optimized in the course of sample pretreatment and instrument analysis. QAC residues in frozen food were extracted using 20 mL methanol-water (90∶10, containing 0.5% formic acid) for 20 min by the vortex shock method. The mixture was ultrasonicated for 10 min and centrifuged at 10000 r/min for 10 min. A 1-mL aliquot of the supernatant was transferred to a new tube and purified using 100 mg of PSA adsorbents. After mixing and centrifugation at 10000 r/min for 5 min, the purified solution was analyzed. Target analytes were separated on an ACQUITY UPLC BEH C8 chromatographic column (50 mm×2.1 mm, 1.7 µm) at a column temperature of 40 ℃ and a flow rate of 0.3 mL/min. The injection volume was 1 µL. Gradient elution was performed using methanol and 5 mmol/L ammonium acetate solution as the mobile phases. Multiple reaction monitoring (MRM) was conducted in the positive electrospray ionization (ESI+) mode. The matrix-matched external standard method was used to quantify seven QACs. The optimized chromatography-based method completely separated the seven analytes. Good linear relationships were obtained for the seven QACs in the range of 0.1-100.0 ng/mL. The correlation coefficient (r2) ranged from 0.9971 to 0.9983. The limits of detection and limits of quantification ranged from 0.5 to 1.0 µg/kg and 1.5 to 3.0 µg/kg, respectively. Accuracy and precision were determined by spiking salmon and chicken samples with 3.0, 10.0, and 100.0 µg/kg of analytes, in compliance with the current legislation, with six replicates per determination. The average recoveries of the seven QACs ranged from 65.4% to 101%. The relative standard deviations (RSDs) were between 0.64% and 16.8%. Matrix effects of the analytes were between -27.5% and 33.4% in salmon and chicken samples after purifying using PSA. The developed method was applied to the determination of seven QACs in rural samples. QACs were detected in only one sample; the level did not exceed European Food Safety Authority specified residue limit standards. The detection method has high sensitivity, good selectivity and stability, and the results are accurate and reliable. It is suitable for the simultaneous rapid determination of seven QAC residues in frozen food. The results provide valuable information for future risk assessment studies targeting this class of compounds.

Integration of Non-targeted Proteomics Mass Spectrometry with Machine Learning for Screening Cooked Beef Adulterated Samples.

The degradation of ingredients in heat-processed meat products makes their authentication challenging. In this study, protein profiles of raw beef, chicken, duck, pork, and binary simulated adulterated beef samples (chicken-beef, duck-beef, and pork-beef) and their heat-processed samples were obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Heat-stable characteristic proteins were found by screening the overlapping characteristic protein ion peaks of the raw and corresponding heat-processed samples, which were discovered by partial least-squares discriminant analysis. Based on the 36 heat-stable characteristic proteins, qualitative classification for the raw and heat-processed meats was achieved by extreme gradient boosting. Moreover, quantitative analysis via partial least squares regression was applied to determine the adulteration ratio of the simulated adulterated beef samples. The validity of the approach was confirmed by a blind test with the mean accuracy of 97.4%. The limit of detection and limit of quantification of this method were determined to be 5 and 8%, respectively, showing its practical aspect for the beef authentication.

Fluorescence Signal Amplification: Red Carbon Dots@SiO2-Induced Ultra-sensitive Immunoassay for Diethyl Phthalate.

Carbon dots as new nanomaterials, have been widely used in rapid detection because of their nondestructive, real-time detection characteristics. Improving the sensitivity and selectivity of the method in complex real samples is new challenge and requirement for sensing technology. Here, we report an ultrasensitive fluorescence immunoassay (FIA) for trace diethyl phthalate (DEP) using red carbon dots@SiO2 (R-CDs@SiO2) as tags. SiO2 as a nanocarrier can effectively improve the bio-functionalization and utilization rate of carbon dots. Moreover, several R-CDs embedded in SiO2 nanospheres can magnify the fluorescence signal and improve sensitivity. R-CDs@SiO2 conjugate anti-DEP antibody (Ab) as fluorescent immunosensor, which can specifically recognize DEP. Under optimization conditions, the detection limit (LOD) of this FIA was calculated as 0.0011 ng/mL. In addition, the recoveries of this established FIA ranged from 96.8 to 108.5%, showing satisfactory accuracy. Compared with GC-MS/MS (LOD µg/mL), the sensitivity of the FIA was significantly improved. As a result, the FIA developed using R-CDs@SiO2 as tags has a high potential for determining trace DEP.

Nonsyndromic supernumerary teeth in patients in National Taiwan University Children's hospital.

Background/purpose: A literature review reveals limited data for supernumerary teeth in Taiwan. This study aimed to analyze the characteristics of nonsyndromic supernumerary teeth in patients in the National Taiwan University Children's Hospital. Materials and methods: This retrospective study analyzed the nonsyndromic supernumerary teeth in 1280 patients (710 boys and 570 girls) based on examination of mainly panoramic radiographs and related radiographs. Chi-square test was used for trend analysis. Results: The incidence of nonsyndromic supernumerary teeth was 11.25% (179 supernumerary teeth in 144 of the 1280 patients). There was a male predominance (4.33: 1, P < 0.0001) for our 144 patients. Most supernumerary teeth were single (63.69%), conical-shaped (78.77%), and unerupted (77.09%). Supernumerary teeth also tended to be located in the premaxilla (93.85%), fully developed (51.40%), invertedly oriented (45.25%), sagittally located in a palatal/lingual position (67.60%), and adjacent to the root and root apex of permanent teeth (70.39%). The supernumerary teeth with a normal orientation (64.52%) had a high potential to erupt into the oral cavity, but the majority of the supernumerary teeth with a transverse orientation (97.22%) or an inverted orientation (100%) were unerupted. Conclusion: The nonsyndromic supernumerary teeth occur most commonly in male patients with a male to female ratio of 4.33: 1. The incidence of nonsyndromic supernumerary teeth in our 1280 patients is 11.25%, and the most frequent location of supernumerary teeth is the anterior maxillary region. More than three quarters of supernumerary teeth are conical-shaped or unerupted. Inverted supernumerary teeth are all embedded in the jawbones.

Effect of extraction methods on the properties of tilapia scale gelatins.

Three types of tilapia scale gelatins (hot water-pretreated gelatin, HWG; acetic acid-pretreated gelatin, AAG; and pepsin enzyme-pretreated gelatin, PEG) were extracted and their gel strength, foaming properties, and emulsifying properties were analyzed. They had different gel strength values: AAG (370 ± 10 g Bloom) > HWG (320 ± 10 g Bloom) > PEG (280 ± 10 g Bloom). The creaming index values of tilapia scale gelatin-stabilized fish oil-loaded emulsions were dependent on gelatin type (HWG ≈ AAG > PEG) at low gelatin concentration (2 mg/mL), whereas they were similar and low (8-10 %) at high gelatin concentration (10 mg/mL). Extraction methods had no consistently significant effects on the gelatin foaming properties. In summary, tilapia scale gelatins had better gel strength and foaming properties and similar or even better emulsifying properties than mammalian gelatins. Therefore, tilapia scales could be a potential source of gelatins to replace mammalian gelatins.