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Polycyclic aromatic hydrocarbons (PAHs) represent important toxic compounds formed in meat products during processing. This study aims to analyze 22 PAHs by QuEChERS coupled with GC–MS/MS in canned minced chicken and pork during processing. After marinating raw minced chicken and pork separately with a standard flavoring formula used for canning meat in Taiwan, they were subjected to different processing conditions including stir-frying, degassing and sterilizing at 115 °C/60 min (low-temperature–long-time, LTLT) and 125 °C/25 min (high-temperature–short-time, HTST). The quantitation of PAHs in these meat products revealed the formation of only three PAHs including acenaphthylene (AcPy), acenaphthene (AcP) and pyrene (Pyr) in canned minced chicken and pork during processing with no significant difference in total PAHs between the meat types. Analysis of PAH precursors showed the presence of benzaldehyde at the highest level, followed by 2-cyclohexene-1-one and trans,trans-2,4-decadienal in canned minced chicken and pork, suggesting PAH formation through the reaction of benzaldehyde with linoleic acid degradation products and of 2-cyclohexene-1-one with C4 compounds through the Diels–Alder reaction, as well as the reaction of trans,trans-2,4-decadienal with 2-butene. Monounsaturated and polyunsaturated fatty acids were present in the largest proportion in LTLT-sterilized chicken/pork, followed by HTST-sterilized chicken/pork and raw chicken/pork, and their levels did not show a high impact on PAH formation, probably due to an insufficient heating temperature and length of time. A two-factorial analysis suggested that PAH formation was not significantly affected by the sterilization condition or meat type. Principal component analysis corroborated the observed results implying the formation of PAHs in canned minced chicken/pork under different processing conditions with an insignificant difference (p > 0.05) between them, with the individual PAH content following the order of Pyr > AcPy > AcP. [ABSTRACT FROM AUTHOR]

This study aims to explore the effects of frying conditions on the formation of HAs and PAHs in crispy pork spareribs, a popular meat commodity sold on Taiwan's market. Raw pork spareribs were marinated, coated with sweet potato powder, and fried in soybean oil and palm oil at 190 °C/6 min or 150 °C/12 min, followed by an analysis of HAs and PAHs via QuEChERS coupled with UPLC-MS/MS and GC-MS/MS, respectively. Both HAs and PAHs in pork spareribs during frying followed a temperature- and time-dependent rise. A total of 7 HAs (20.34–25.97 μg/kg) and 12 PAHs (67.69–85.10 μg/kg) were detected in pork spareribs fried in soybean oil and palm oil at 150 °C/12 min or 190 °C/6 min, with palm oil producing a higher level of total HAs and a lower level of total PAHs than soybean oil. The content changes of amino acid, reducing sugar, and creatinine played a vital role in affecting HA formation, while the degree of oil unsaturation and the contents of precursors including benzaldehyde, 2-cyclohexene-1-one, and trans,trans-2,4-decadienal showed a crucial role in affecting PAH formation. The principal component analysis revealed that HAs and PAHs were formed by different mechanisms, with the latter being more liable to formation in pork spareribs during frying, while the two-factorial analysis indicated that the interaction between oil type and frying condition was insignificant for HAs and PAHs generated in crispy pork spareribs. Both CcdP (22.67–32.78 μg/kg) and Pyr (16.70–22.36 μg/kg) dominated in PAH formation, while Harman (14.46–17.91 μg/kg) and Norharman (3.41–4.55 μg/kg) dominated in HA formation in crispy pork spareribs during frying. The outcome of this study forms a basis for learning both the variety and content of HAs and PAHs generated during the frying of pork spareribs and the optimum frying condition to minimize their formation. [ABSTRACT FROM AUTHOR]

This study evaluates the management capacity ability and profitable capacity of eight public-private partnership hospitals in Taiwan from 2015 to 2020. By conducting various ratio analyses of the financial statement, this study found these hospitals have achieved a balance between management efficiency and profitability, thereby confirming the viability of the PPP model for hospital management. In addition, the subject hospitals play a vital role as isolation hospitals during the COVID-19 pandemic. Beyond offering medical assistance to infected individuals, these hospitals contribute to the integrity of Taiwan's medical network, mitigating the impact of the pandemic. Overall, establishing and managing hospitals with PPP partnership is a feasible solution as it alleviates governmental financial burdens related to medical welfare and achieves profitability. [ABSTRACT FROM AUTHOR]

Toxic compounds such as heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs) can be produced during food processing, especially meat products. This study aims to monitor the formation of HAs and PAHs in fried pork fiber, a common meat product in Taiwan, at different processing conditions. A total of six experimental groups, including raw pork tenderloin, dried pork filaments, sesame oil-stir-fried pork at 160 °C for 15 min, sesame oil-stir-fried pork at 200 °C for 6 min, lard-stir-fried pork at 160 °C for 15 min, and lard-stir-fried pork at 200 °C for 6 min, were prepared and analyzed for formation of HAs via UPLC-MS/MS and PAHs via GC-MS/MS in triplicate. Frying in sesame oil or lard showed a greater content of total HAs in fried pork fiber processed at 160 °C for 15 min than at 200 °C for 6 min. However, in the same heating conditions, pork fiber fried in sesame oil produced a higher level of total HAs than that fried in lard. Of the various HAs in fried pork fiber, both Harman and Norharman were generated in the highest amount. The precursors, including reducing sugar, amino acid, and creatine/creatinine, played a vital role in HAs formation in fried pork fiber. For total PAHs, the highest level was shown for pork fiber fried in lard at 200 °C/6 min, followed by frying in sesame oil at 200 °C/6 min and 160 °C/15 min, and in lard at 160 °C/15 min. Like HAs, at the same heating condition, a greater content of total PAHs was produced in pork fiber fried in sesame oil than in lard. Notably, the highly toxic benzo[a]pyrene was undetected in fried pork fiber. The PAH precursor benzaldehyde was shown to generate at a much higher level than 2-cyclohexene-1-one and trans,trans-2,4-decadienal in fried pork fiber, and it should play a more important role in PAH formation. Principal component analysis (PCA) also revealed that the formation mechanism of HAs and PAHs in fried pork fiber was different. [ABSTRACT FROM AUTHOR]

This study aims to simultaneously extract heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs) from ground pork for respective analysis by UPLC-MS/MS and GC-MS/MS, and study the effects of different flavorings and marinating time length on their formation and inhibition. Results showed that both HA and PAH contents followed a time-dependent increase during marinating, with HAs being more susceptible to formation than PAHs. The total HA contents in unmarinated pork and juice was, respectively, 61.58 and 139.26 ng/g, and rose to 2986.46 and 1792.07 ng/g after 24-h marinating, which can be attributed to the elevation of reducing sugar and creatinine contents. The total PAH contents in unmarinated pork and juice were, respectively, 34.56 and 26.84 ng/g, and increased to 55.93 and 44.16 ng/g after 24-h marinating, which can be due to the increment of PAH precursors such as benzaldehyde, 2-cyclohexene-1-one and trans,trans-2,4-decadienal. Incorporation of 0.5% (w/v) cinnamon powder or 0.5% (w/v) green tea powder was effective in inhibiting HA formation with the former showing a more pronounced effect for marinated pork, while the latter was for marinated juice. However, their addition was only effective in inhibiting PAH formation in marinated pork. Principle component analysis revealed the relationship between HA and PAH formation in ground pork and juice during marinating. [ABSTRACT FROM AUTHOR]

The bacterial flagellar motor (BFM) is a nanomachine that rotates the flagellum to propel many known bacteria. The BFM is powered by ion transit across the cell membrane through the stator complex, a membrane protein. Different bacteria use various ions to run their BFM, but the majority of BFMs are powered by either proton (H+) or sodium (Na+) ions. The transmembrane (TM) domain of the B-subunit of the stator complex is crucial for ion selectivity, as it forms the ion channel in complex with TM3 and TM4 of the A-subunit. In this study, we reconstructed and engineered thirteen ancestral sequences of the stator B-subunit to evaluate the functional properties and ionic power source of the stator proteins at reconstruction nodes to evaluate the potential of ancestral sequence reconstruction (ASR) methods for stator engineering and to test specific motifs previously hypothesized to be involved in ion-selectivity. We found that all thirteen of our reconstructed ancient B-subunit proteins could assemble into functional stator complexes in combination with the contemporary Escherichia coli MotA-subunit to restore motility in stator deleted E. coli strains. The flagellar rotation of the thirteen ancestral MotBs was found to be Na+ independent which suggested that the F30/Y30 residue was not significantly correlated with sodium/proton phenotype, in contrast to what we had reported previously. Additionally, four among the thirteen reconstructed B-subunits were compatible with the A-subunit of Aquifex aeolicus and able to function in a sodium-independent manner. Overall, this work demonstrates the use of ancestral reconstruction to generate novel stators and quantify which residues are correlated with which ionic power source. [ABSTRACT FROM AUTHOR]

Invasive fungal infections are difficult to treat. The few available antifungal drugs have problems with toxicity or efficacy, and resistance is increasing. To overcome these challenges, existing therapies may be enhanced by synergistic combination with another agent. Previously, we found amphotericin B (AMB) and the iron chelator, lactoferrin (LF), were synergistic against a range of different fungal pathogens. This study investigates the mechanism of AMB-LF synergy, using RNA-seq and network analyses. AMB treatment resulted in increased expression of genes involved in iron homeostasis and ATP synthesis. Unexpectedly, AMB-LF treatment did not lead to increased expression of iron and zinc homeostasis genes. However, genes involved in adaptive response to zinc deficiency and oxidative stress had decreased expression. The clustering of co-expressed genes and network analysis revealed that many iron and zinc homeostasis genes are targets of transcription factors Aft1p and Zap1p. The aft1Δ and zap1Δ mutants were hypersensitive to AMB and H2O2, suggesting they are key regulators of the drug response. Mechanistically, AMB-LF synergy could involve AMB affecting the integrity of the cell wall and membrane, permitting LF to disrupt intracellular processes. We suggest that Zap1p- and Aft1p-binding molecules could be combined with existing antifungals to serve as synergistic treatments. [ABSTRACT FROM AUTHOR]

Background: Aspergillus flavus is intensively studied for its role in infecting crop plants and contaminating produce with aflatoxin, but its role as a human pathogen is less well understood. In parts of the Middle East and India, A. flavus surpasses A. fumigatus as a cause of invasive aspergillosis and is a significant cause of cutaneous, sinus, nasal and nail infections.Methods: A collection of 45 clinical and 10 environmental A. flavus isolates from Iran were analysed using Variable-Number Tandem-Repeat (VNTR) markers with MICROSAT and goeBURST to determine their genetic diversity and their relatedness to clinical and environmental A. flavus isolates from Australia. Phylogeny was assessed using partial β-tubulin and calmodulin gene sequencing, and mating type was determined by PCR. Antifungal susceptibility testing was performed on selected isolates using a reference microbroth dilution method.Results: There was considerable diversity in the A. flavus collection, with no segregation on goeBURST networks according to source or geographic location. Three Iranian isolates, two from sinus infections and one from a paranasal infection grouped with Aspergillus minisclerotigenes, and all produced B and G aflatoxin. Phylogenic analysis using partial β-tubulin and calmodulin sequencing confirmed two of these as A. minisclerotigenes, while the third could not be differentiated from A. flavus and related species within Aspergillus section flavi. Based on epidemiological cut-off values, the A. minisclerotigens and A. flavus isolates tested were susceptible to commonly used antifungal drugs.Conclusions: This is the first report of human infection due to A. minisclerotigenes, and it raises the possiblity that other species within Aspergillus section flavi may also cause clinical disease. Clinical isolates of A. flavus from Iran are not distinct from Australian isolates, indicating local environmental, climatic or host features, rather than fungal features, govern the high incidence of A. flavus infection in this region. The results of this study have important implications for biological control strategies that aim to reduce aflatoxin by the introduction of non-toxigenic strains, as potentially any strain of A. flavus, and closely related species like A. minisclerotigenes, might be capable of human infection. [ABSTRACT FROM AUTHOR]

• The formation of 16 PAHs have been investigated during pyrolysis. • Phenylalanine and glucose are important precursors of PAHs. • Higher temperature glucose heating produces more predominant four to five-ring PAHs. Polycyclic aromatic hydrocarbons (PAHs), prominent carcinogens formed during food processing, pose health risks through long-term consumption. This study focuses on 16 priority PAHs in the European Union, investigating their formation during pyrolysis. Glucose, amino acids and fatty acids are important food nutrients. To further explore whether these nutrients in food form PAHs during heating, a single chemical model method was used to heat these nutrients respectively, and GC–MS/MS was used to identify and quantify the obtained components. Glucose is the most basic nutrient in food, so the influence of water, pH, temperature and other factors on the formation of PAHs was studied in the glucose model. At the same time, the models of amino acids and fatty acids were used to assist in improving the entire nutrient research system. According to our results, some previously reported mechanisms of PAHs formation by fatty acids heating were confirmed. In addition, glucose and amino acids could also produce many PAHs after heating, and some conclusions were improved by comparing the intermediates of PAHs from three types of nutrients. [ABSTRACT FROM AUTHOR]

[Display omitted] • The precursor components in the formation of HAAs have been investigated using UPLC-MS/MS. • The results confirmed the previously reported precursors and formation mechanisms of HAAs. • Some potential direct and indirect precursors for HAAs were discovered. The prevention and control of heterocyclic aromatic amines (HAA) formation to mitigate of potential risks to humans, can be achieved by targeting their precursors. In this study, the detailed roles of individual and excess component (20 common α-amino acids, creatine, creatinine, and glucose) on HAA formation in roasted beef patties were examined using UPLC-MS/MS. The results confirmed the reported classical precursors of HAAs. Some components regulated the competitive production of Norharman and Harman. Glycine (Gly) and glucose favored Norharman formation, while cysteine (Cys) and phenylalanine (Phe) for Harman. Serine (Ser) and threonine (Thr) were identified as potential precursors for IQx-type HAAs. Interestingly, methionine (Met), Gly, Thr, Cys, alanine (Ala), and Ser were revealed as more targeted underlying precursors for 1,6-DMIP and 1,5,6-TMIP, and the formation mechanism was inferred. Furthermore, Pro, Leu, His, Ile, Lys and Asp were considered as great inhibitors for HAAs. [ABSTRACT FROM AUTHOR]