Recent advancements in the extraction and analysis of phthalate acid esters in food samples.

Phthalate acid esters (PAEs) are ubiquitous environmental pollutants present in food samples, necessitating accurate detection for risk assessment and remediation efforts. This review provides an updated overview of the recent progress on the PAEs analysis regarding sample pretreatment techniques and analytical methodologies over the latest decade. Advances in sample preparation include solid-based extraction techniques replacing conventional liquid-liquid extraction, with solid sorbents emerging as promising alternatives due to their minimal solvent consumption and enhanced selectivity. Although techniques like the microextraction methods offer versatility and reduced solvent reliance, there is a need for more efficient and environmentally friendly techniques enabling on-site portable detection. High-resolution mass spectrometry is increasingly utilized for its enhanced sensitivity and reduced contamination risks. However, challenges persist in developing in situ analytical techniques for trace PAEs in complex food samples. Future research should prioritize novel analytical techniques with superior sensitivity and selectivity, addressing current limitations to meet the demand for precise PAEs detection in diverse food matrices.

Thermal responsive sodium alginate/polyacrylamide/poly (N-isopropylacrylamide) ionic hydrogel composite via seeding calcium carbonate microparticles for the engineering of ultrasensitive wearable sensors.

The design of polyelectrolyte hydrogel with unique tensile and adhesive properties which can be applied across disciplines has gradually become a popular trend. However, the phenomenon of global warming and the emergence of extreme weather, it still faces some urgent problems that should be solved, such as the optimal utilization of polyelectrolyte hydrogel across a wide range of temperatures. Herein, a wide temperature sensitivity and conductivity hydrogel based on sodium alginate, acrylamide and N-isopropylacrylamide was constructed, which exhibited excellent adhesion and temperature conductivity. It is worth noting that after the inclusion of CaCO3 and NaCl in the hydrogel, the hydrogel showed excellent tensile properties (fracture strain >2000 %). Within a wide temperature range (-15-50 °C), it exhibits exceptional electrical conductivity (2.75 S ∗ m-1) and sensitivity (GF = 8.76 under high strain). This innovative intelligent polyelectrolyte hydrogel provides suitable strategy for flexible sensors, smart wearable devices and medical monitoring equipment.

Gut microbiota dysbiosis deteriorates immunoregulatory effects of tryptophan via colonic indole and LBP/HTR2B-mediated macrophage function.

Tryptophan (Trp) has been shown to regulate immune function by modulating gut serotonin (5-HT) metabolism and signaling. However, the mechanisms underlying the microbial modulation of gut 5-HT signaling in gut inflammation with gut microbiota dysbiosis require further investigation. Here, we investigated the effects of Trp supplementation on the composition and metabolism of the gut microbiome and 5-HT signaling-related gut immune function using a dextran sodium sulfate (DSS)-induced colitis mouse model coupled with antibiotic exposure. The results showed that antibiotic treatment before but not during DSS treatment decreased the immunoregulatory effects of Trp and aggravated gut inflammation and body weight loss in mice. Metagenomic analysis revealed that the fecal microbiota transplantation of Trp-enriched gut microbiota to recipient mice subject to antibiotic pre-exposure and DSS treatment alleviated inflammation by increasing the relative abundances of Lactobacillus and Parabacteroides and the microbial production of indole coupled with the activation of the 5-HT receptor 2B (HTR2B) in the colon. Transcriptomic analysis showed that HTR2B agonist administration strengthened the beneficial effects of Trp in DSS-induced colitis mice with antibiotic exposure by reducing gut lipopolysaccharide-binding protein (LBP) production, IκB-α/nuclear factor-κB signaling, and M1 macrophage polarization. Indole treatment reduced LBP production and M1 macrophage polarization both in mice with DSS-induced colitis and in lipopolysaccharide-treated mouse macrophages; however, the HTR2B antagonist reversed the effects of indole. Our findings provide the basis for developing new dietary and therapeutic interventions to improve gut microbiota dysbiosis-associated inflammatory gut disorders and diseases.

5-Formylcytosine is an activating epigenetic mark for RNA Pol III during zygotic reprogramming.

5-Methylcytosine (5mC) is an established epigenetic mark in vertebrate genomic DNA, but whether its oxidation intermediates formed during TET-mediated DNA demethylation possess an instructive role of their own that is also physiologically relevant remains unresolved. Here, we reveal a 5-formylcytosine (5fC) nuclear chromocenter, which transiently forms during zygotic genome activation (ZGA) in Xenopus and mouse embryos. We identify this chromocenter as the perinucleolar compartment, a structure associated with RNA Pol III transcription. In Xenopus embryos, 5fC is highly enriched on Pol III target genes activated at ZGA, notably at oocyte-type tandem arrayed tRNA genes. By manipulating Tet and Tdg enzymes, we show that 5fC is required as a regulatory mark to promote Pol III recruitment as well as tRNA expression. Concordantly, 5fC modification of a tRNA transgene enhances its expression in vivo. The results establish 5fC as an activating epigenetic mark during zygotic reprogramming of Pol III gene expression.

Biomechanical features and parametric calibration of a bilayer bonded particle model for the cornstalk during harvest.

The optimal discrete element model and bonding parameters that match the structural features of cornstalks during harvest were obtained. Based on the differences in mechanical properties of the stem bark and stem pith in the inter-nodal cornstalk, the biomechanical-specific parameters were measured using the compression, shear, and bending tests. The bonded particle models of stem bark and stem pith were constructed using fraction particles with radii of 1 mm and 1.47 mm, which were further bound to form a bilayer-bonded particle model of the cornstalk. The Plackett-Burman, steepest ascent, and response surface tests were conducted to identify the factors and their optimal values that significantly impacted the stem bark-stem bark, stem pith-stem pith, and stem bark-stem pith bonding parameters. The cornstalk's shear and bending mechanical properties were assessed to verify the overall characteristic parameters. The findings revealed that the cornstalk model created, and the calibrated bonding parameters, were highly accurate and capable of simulating the shearing and bending behaviors of the real cornstalk. The inter-nodal cornstalk's bonded particle model created and the identified bonding parameters for the cornstalk could contribute to a theoretical and research basis for the next stage in cornstalk modeling with nodes and other applications.

Identification of procyanidins as α-glucosidase inhibitors, pancreatic lipase inhibitors, and antioxidants from the bark of Cinnamomum cassia by multi-bioactivity-labeled molecular networking.

This study examined the suppressive effects of 16 selected plant-based foods on α-glucosidase and pancreatic lipase and their antioxidant properties. Among these, the bark of Cinnamomum cassia (Cinnamon, WLN-FM 15) showed the highest inhibitory activity against α-glucosidase and the highest antioxidant activity. Additionally, WLN-FM 15 showed promising results in the other tests. To further identify the bioactive constituents of WLN-FM 15, a multi-bioactivity-labeled molecular networking approach was used through a combination of GNPS-based molecular networking, DPPH-HPLC, and affinity-based ultrafiltration-HPLC. A total of nine procyanidins were identified as antioxidants and inhibitors of α-glucosidase and pancreatic lipase in WLN-FM 15. Subsequently, procyanidins A1, A2, B1, and C1 were isolated, and their efficacy was confirmed through functional assays. In summary, WLN-FM 15 has the potential to serve as a functional food ingredient with the procyanidins as its bioactive constituents. These results also suggest that the multi-bioactivity-labeled molecular networking approach is reliable for identifying bioactive constituents in plant-based foods.

Research on the development relationship between safety production indicators and economic and social indicators in China.

In order to study the relationship between China's safety production indicators and economic and social indicators, the development trend of indicator data in the past 20 years was statistically analyzed, and qualitative and quantitative research was conducted using grey relational analysis and multiple linear regression analysis methods. In the past two decades, there has been a significant improvement in the number of deaths, work-related injuries, and occupational patients in China's safety production, and the country's three categories of 14 economic and social indicators have achieved rapid development. Using the grey relation analysis method, the grey correlation degree between the number of deaths, work-related injuries, and occupational patients in China over the past twenty years and 14 economic and social indicators was obtained. The ranking of economic and social indicators that affect the number of deaths, work-related injuries, and occupational patients varies greatly. A multiple linear regression model was established for the number of deaths, work-related injuries, occupational diseases, and 14 economic and social indicators. The rationality of the model was verified from four aspects: R2, F-value, P-value, and deviation between actual and fitted values. Provide guidance for the development of safety production indicators and economic and social indicators in China through research.

Expression and clinical significance of CLDN7 and its immune-related cells in breast cancer.

BACKGROUND: CLDN is a core component of tight junctions (TJs). Abnormal expressions of CLDNs are commonly detected in various types of tumors. CLDNs are of interest as a potential therapeutic target. CLDNs are closely associated with most cancers of epithelial origin, especially when CLDN7 promotes cancer cell metastasis, such as in gastric, cervical, and ovarian cancers.Its expression and prognosis in breast cancer (BC) remain unknown.The purpose of this study was to investigate the expression pattern of CLDN7 and related immune factors in BC and shed light on a better therapeutic avenue for BC patients. METHOD: The cBioPortal, GEPIA, and TCGA databases were used to comprehensively assess the expression of CLDN7 in BC. The Kaplan-Meier Plotter (KMP) database was applied to examine the relationship among the CLDN7 overexpression (OE), prognosis, and overall survival (OS) of BC patients. Immunohistochemical staining was performed on 92 BC tissue samples and 20 benign breast tumors to verify the expression level of CLDN-7 protein and its correlation with clinicopathological features and prognosis. TIMER2.0 was used to analyze the correlation between the CLDN7 OE and immune gene activation using BC-related transcriptomic data. Enrichment analyses of CLDN7-related immune pathways were conducted using online databases. The risk of expression of CLDN7-related immune genes was assessed and differentially expressed (DE) genes were included in the construction of the risk prognosis nomogram. RESULTS: Both database analysis and clinical sample validation results showed that CLDN7 was significantly overexpressed (OE) in BC, and the OE was correlated with poor DFS in BC patients (p < 0.05). TIMER2.0 analysis indicated that CLDN7 OE was negatively associated with the activation of B-cells, CD4+ T-cells, and CD8+ T-cells but positively with the M0 macrophages. Pathway enrichment analysis suggested that CLDN7-related immune factors were mostly involved in the NF-κB and T-cell receptor (TCR) signaling pathways. Univariate Cox regression was used to analyze the correlation between 52 CLDN7 related genes and OS, and 22 genes that are related to prognosis were identified. Prognostic genes were included in the prognostic nomogram of BC with a C-index of 0.76 to predict the 3-year and 5-year OS probabilities of BC individuals. CONCLUSIONS: These findings provide evidence for the role of CLDN7-linked tumor immunity, suggesting that CLDN7 might be a potential immunotherapeutic target for BC, and its association with immune markers could shed light on the better prognosis of BC.

Sensitive extraction of seven pesticide residues from environmental water with magnetic graphene oxide-based covalent organic framework.

The use of pesticides has increased with the development of agriculture. However, due to the trace content and the matrix's inherent complexity in environmental water, development of rapid and sensitive detection method present significant challenges in the analysis of pesticide residues. The study synthesized magnetic graphene oxide (MGO) by combining superparamagnetic nanoparticles with the easy modification of graphene oxide (GO). Covalent organic frameworks (COFs) were then modified to have a large specific surface area. Finally, magnetic graphene oxide-based covalent organic frameworks, namely MGO-COFs, were obtained with a spherical structure and used as magnetic solid-phase extraction materials, which was successfully used to determine the seven pesticide residues in environmental samples in conjunction with high performance liquid chromatography. The method has a wide linear range for the tested pesticides, with satisfactory correlation coefficients (R ≥ 0.099) and low detection limits (0.3-1.21 µg L-1). The correlation coefficients for all seven pesticides were high (R2 ≥ 0.9996). The spiked recoveries, exhibiting a range of 91.3 to 109 %, demonstrated that the developed MGO-COF-MSPE-HPLC-UV method is simple, efficient, and suitable for the analysis and detection of seven pesticide residues in environmental water.

Milk-Derived Extracellular Vesicles Carrying ssc-let-7c Alleviate Early Intestinal Inflammation and Regulate Macrophage Polarization via Targeting the PTEN-Mediated PI3K/Akt Pathway.

Milk-derived extracellular vesicles (mEVs) are beneficial to the health of infants. However, the effect of mEVs on early intestinal inflammation is not well established. Herein, weaned colitic mice were used to explore the potential effects and underlying mechanisms of porcine mEVs (pmEVs) on intestinal inflammation during early life. We found that pmEVs administration attenuated early life intestinal inflammation and promoted colonic barrier integrity in mice. The anti-inflammatory effect of pmEVs was achieved by shifting a proinflammatory macrophage (M1) toward an anti-inflammatory macrophage (M2). Moreover, pmEVs can be absorbed by macrophages and reduce proinflammatory polarization (stimulated by LPS) in vitro. Noteworthily, ssc-let-7c was found to be highly expressed in pmEVs that can regulate the polarization of macrophages by targeting the tensin homologue deleted on chromosome ten (PTEN), thereby activating the PI3K/Akt pathway. Collectively, our findings revealed a crucial role of mEVs in early intestinal immunity and its underlying mechanism.

One-Pot Preparation of Layered Double Hydroxide-Engineered Boric Acid Root and Application in Wastewater.

Heavy metals and organic pollutants are prevalent in water bodies, causing great damage to the environment and human beings. Hence, it is urgent to develop a kind of adsorbent with good performance. Anion interlacing layered double hydroxides (LDHs) are a promising adsorbent for the sustainable removal of heavy metal ions and dyes from wastewater. Using aluminum chloride, zinc chloride and ammonium pentaborate tetrahydrate (NH4B5O8 · 4H2O, BA) as raw materials, the LDHs complex (BA-LDHs) of B5O8- intercalation was prepared by one-step hydrothermal method. The BA-LDHs samples were characterized by a X-ray powder diffractometer (XRD), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR) and the Brunauer-Emmett-Teller (BET) method. The results showed that B5O8- was successfully intercalated. Adsorption experimental results suggested that BA-LDHs possess a maximum adsorption capacity of 18.7, 57.5, 70.2, and 3.12 mg·g-1 for Cd(II), Cu(II), Cr(VI) and Methylene blue (MB) at Cs = 2 g·L-1, respectively. The adsorption experiment conforms to the Langmuir and Freundlich adsorption models, and the kinetic adsorption data are well fitted by the pseudo-second-order adsorption kinetic equation. The as-prepared BA-LDHs have potential application prospects in the removal of heavy metals and dyes in wastewater. More importantly, they also provide a strategy for preparing selective adsorbents.

Constructing Porous Energetic Spherulites via Solvation-Growth Coupling for Enhanced Combustion.

The fabrication of materials with hierarchical structures has garnered great interest, owing to the potential for significantly enhancing their functions. Herein, a strategy of coupling molecular solvation and crystal growth is presented to fabricate porous spherulites of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), an important energetic material. With the addition of polyvinylpyrrolidone in the antisolvent crystallization, the metastable solvate of CL-20 is formed and grows spherulitically, and spontaneously desolvates to obtain the porous spherulite when filtration, in which the characteristic peak of the nitro group of CL-20 shifts detected by the in situ micro-confocal Raman spectroscopy. The effect of polyvinylpyrrolidone is thought to induce the solvation of CL-20, confirmed by density functional theory calculations, meanwhile acting on the (020) face of CL-20 to trigger spherulitic growth, demonstrated through infrared spectroscopy and Rietveld refinement of powder X-ray diffraction. Moreover, compared to common CL-20 crystals, porous spherulites exhibit enhanced combustion with increases of 6.24% in peak pressure, 40.21% in pressurization rate, and 9.63% in pressure duration effect, indicating the capability of hierarchical structures to boost the energy release of energetic crystals. This work demonstrates a new route via solvation-growth coupling to construct hierarchical structures for organic crystals and provides insight into the structure-property relations for material design.

Fabrication of magnetic hydrophilic imprinted polymers via two-step immobilization approach for targeted detecting bisphenol A.

Molecularly imprinted polymer with water-compatibility for effective separation and enrichment of targeted trace pollutants from complicated matrix has captured extensive attention in terms of their high selectivity and matrix compatibility. This study focuses on modified ß-cyclodextrin is used as a hydrophilic functional monomer to develop magnetic molecularly imprinted polymers (MMIPs). MMIPs were prepared using Fe3O4 nanoparticles as carriers and bisphenol A (BPA) as templates using a two-step fixation strategy and surface imprinting technology. The structural characteristic and binding properties of the prepared MMIPs were thoroughly studied. The MMIPs exhibited high crystallinity, high adsorption capacity, fast rebinding rate, remarkable selectivity and distinguish reusability. In addition, through magnetic solid-phase extraction separation technology and high-performance liquid chromatography ultraviolet quantitative detection technology, MMIPs are used for selective enrichment and detection of BPA in complex media such as environmental water and milk. This work provides a new route to construct the hydrophilic molecularly imprinted materials and a new sight on developing more effective sample pretreatment strategies for monitoring targeted pollution in complicated aqueous media.

Enhanced carboxylation of furoic salt with CO2 by ZnCl2 coordination for efficient production of 2,5-furandicarboxylic acid.

C-H carboxylation of furoic acid (FA) with CO2 is an atom-efficient strategy to produce 2,5-furandicarboxylic acid (2,5-FDCA) from lignocellulose. The existing carbonate-promoted CO2 carboxylation processes rely on the use of large amounts of expensive Cs2CO3 as a deprotonating reagent and molten salt. Substitution of Cs with other cheap and abundant alkali ions (such as K and Na) can reduce the use of Cs, but it faces the problem of a low yield of 2,5-FDCA. This study found that the addition of catalytic amounts of ZnCl2 as a Lewis acid can increase the yield of 2,5-FDCA in the CO2 carboxylation reaction of Na/K-FA in a molten salt reaction system. 1H NMR analysis and DFT calculations confirmed that ZnCl2 coordinates with the furan ring through electron transfer from the conjugated furan ring to Zn2+, thereby activating the H at the C5 position of Na/K-FA. This coordination lengthened the C5-H bond and lowered its heterolytic dissociation energy, making it more susceptible to being deprotonated by CO32- and subsequently carboxylated by CO2. The developed Lewis acid coordination strategy provides a new idea for the efficient construction of C-C bonds between CO2 and aromatics through carbonate-promoted C-H carboxylation.

Mucin alleviates colonic barrier dysfunction by promoting spermine accumulation through enhanced arginine metabolism in Limosilactobacillus mucosae.

Dietary fiber deprivation is linked to probiotic extinction, mucus barrier dysbiosis, and the overgrowth of mucin-degrading bacteria. However, whether and how mucin could rescue fiber deprivation-induced intestinal barrier defects remains largely unexplored. Here, we sought to investigate the potential role and mechanism by which exogenous mucin maintains the gut barrier function. The results showed that dietary mucin alleviated fiber deprivation-induced disruption of colonic barrier integrity and reduced spermine production in vivo. Importantly, we highlighted that microbial-derived spermine production, but not host-produced spermine, increased significantly after mucin supplementation, with a positive association with upgraded colonic Lactobacillus abundance. After employing an in vitro model, the microbial-derived spermine was consistently dominated by both mucin and Lactobacillus spp. Furthermore, Limosilactobacillus mucosae was identified as an essential spermine-producing Lactobacillus spp., and this isolated strain was responsible for spermine accumulation, especially after adhering to mucin in vitro. Specifically, the mucin-supplemented bacterial supernatant of Limosilactobacillus mucosae was verified to promote intestinal barrier functions through the increased spermine production with a dependence on enhanced arginine metabolism. Overall, these findings collectively provide evidence that mucin-modulated microbial arginine metabolism bridged the interplay between microbes and gut barrier function, illustrating possible implications for host gut health. IMPORTANCE: Microbial metabolites like short-chain fatty acids produced by dietary fiber fermentation have been demonstrated to have beneficial effects on intestinal health. However, it is essential to acknowledge that certain amino acids entering the colon can be metabolized by microorganisms to produce polyamines. The polyamines can promote the renewal of intestinal epithelial cell and maintain host-microbe homeostasis. Our study highlighted the specific enrichment by mucin on promoting the arginine metabolism in Limosilactobacillus mucosae to produce spermine, suggesting that microbial-derived polyamines support a significant enhancement on the goblet cell proliferation and barrier function.

Fabrication of molecularly imprinted carbon nanotubes integrating ionic liquids for efficient detection of perfluoroalkyl carboxylic acid in environmental water.

It is extremely significant while challenging to accurately detect low-levels of perfluoroalkyl carboxylic acid compounds (PFCAs) in environmental water. Herein, adopting perfluorotetradecanoic acid as the dummy template, selective molecularly imprinted composites (CNTs@ILs@MIPs) grafted carbon nanotubes integrating hydrophilic ionic liquids were successfully prepared via surface imprinting and dummy-template imprinting techniques. The obtained CNTs@ILs@MIPs were applied as selective extraction adsorbent for specifically extract PFCAs in environmental water coupled with gas chromatography-mass spectrometry quantification. Detailed studies were conducted on the main preparation parameters and extraction conditions. The CNTs@ILs@MIPs displayed excellent adsorptivity, and the established method exhibited low LODs (0.60-1.64 ng L-1), wide linearity with R2 above 0.9994, and satisfactory adsorption recoveries (80.5-112.5%) for seven PFCAs. This proposed method provides a new applicable approach for the detection of targeted pollutants in environmental water by utilizing the high affinity and recognition ability of molecularly imprinted carbon nanotube functional materials modified with ionic liquids.

Effect of pH on the ozonolysis degradation of p-nitrophenol in aquatic environment and the synergistic effect of hydroxy radical.

Density functional theory (DFT) was employed to elucidate the mechanisms for ozonolysis reaction of p-nitrophenol (PNP) and its anion form aPNP. Thermodynamic data, coupled with Average Local Ionization Energies (ALIE) analysis, reveal that the ortho-positions of the OH/O- groups are the most favorable reaction sites. Moreover, rate constant calculations demonstrate that the O3 attack on the C2-C3 bond is the predominant process in the reaction between neutral PNP and O3. For the aPNP + O3 reaction, the most favorable pathways involve O3 attacking the C1-C2 and C6-C1 bonds. The rate constant for PNP ozonolysis positively correlates with pH, ranging from 5.47 × 108 to 2.86 × 109 M-1 s-1 in the natural aquatic environment. In addition, the formation of hydroxyl radicals in the ozonation process of PNP and the mechanisms of its synergistic reaction of PNP with ozone were investigated. Furthermore, the ozonation and hydroxylation processes involving the intermediate OH-derivatives were both thermodynamically and kinetic analyzed, which illustrate that OH radicals could promote the elimination of PNP. Finally, the toxic of PNP and the main products for fish, daphnia, green algae and rat were assessed. The findings reveal that certain intermediates possess greater toxicity than the original reactant. Consequently, the potential health risks these compounds pose to organisms warrant serious consideration.

Porous chlorine-functionalized covalent organic framework anchored graphene aerogel composite for synergically enhanced solid phase microextraction of polychlorinated naphthalene in environmental water.

The residues of polychlorinated naphthalenes (PCNs) produced in multiple industrial production and life processes are continuously entering environmental waters through atmospheric deposition and land drainage, and the water pollution caused by PCNs is continuing public concern due to their potential threat to aquatic ecosystems and public health. Herein, a new chlorine-functionalized covalent organic framework anchored graphene aerogel (COF-GA) was synthesized by covalent modification technology and used as fiber coating of solid-phase microextraction for synergically enhanced extraction of PCNs in environmental water. The extraction efficiency of COF-GA coated fiber was superior to commercial fiber due to the multiple interactions (π-π, hydrophobic interaction, and halogen bonding interaction). The COF-GA coated fiber has good stability, can avoid water vapor interference at 80 °C for a long time (30 -50 min) to maintain adsorption equilibrium, and can be reused at least 96 times. Combined with gas chromatography-tandem mass spectrometry, a sensitive method for the high-efficient enrichment (enrichment factors were 501 -7453 folds) and ultra-sensitive detection (LODs were 0.001 -0.428 pg/mL) of PCNs in environmental water was established. The enrichment factor for PCNs is significantly higher than in previous studies. This proposed method provides new technical support for the daily monitoring and risk assessment of trace PCNs in environmental water.

A three-dimensional hierarchical porous graphene aerogel as a fiber coating for headspace solid-phase microextraction: Enhancing the enrichment and detection of polychlorinated naphthalenes in fish.

In this study, a novel three-dimensional hierarchical porous deep eutectic solvents-modified graphene aerogel (3D DES-GA) was synthesized for use as a solid-phase microextraction (SPME) fiber coating. The SPME fiber was characterized by its fluffy and hierarchical porous structure, uniform thickness, and rapid mass transfer capabilities. This fiber demonstrated a lifetime (≥160 uses) and excellent precision (with relative standard deviations of 2.4-6.6% for single fiber and 6.0-9.8% for fiber-to-fiber repeatability). The SPME fiber also exhibited remarkable extraction performance for polycyclic aromatic hydrocarbons and polychlorinated biphenyls, which are common persistent organic pollutants in environmental samples. When combined with gas chromatography-tandem mass spectrometry, the method allowed for high-efficiency extraction (enrichment factors ranging from 1225 to 4652 folds) and sensitive determination (limit of detection ranging from 0.010 to 0.056 pg g-1) of polychlorinated naphthalenes (PCNs) in complex samples. To validate this method, we applied it to the determination of four PCNs in five types of fish tissues. The results revealed the presence of 1-chloronaphthalene at concentrations of 7.0 ± 2.9-34.8 ± 2.1 pg g-1 and 1,4-dichloronaphthalene at concentrations of 6.0 ± 0.3-10.9 ± 1.4 pg g-1 in three fish species. Compared with reported sample pretreatment methods reported in the literature, this proposed headspace SPME method offers additional advantages, including simplicity of operation and reduced sample and organic solvent consumption.

Effects of Resistant Starch Infusion, Solely and Mixed with Xylan or Cellulose, on Gut Microbiota Composition in Ileum-Cannulated Pigs.

Fermentation of dietary fiber (DF) is beneficial for gut health, but its prebiotic effects are often impeded in the distal large intestine because of the fast degradation of fermentable substrates. One way to enhance the prebiotic effect of DF is to deliver fibers to the lower parts of the gut, which can be achieved by mixing different kinds of fiber. Therefore, in the present study, an ileum-cannulated pig model was employed to investigate the fermentation influence in the large intestine by infusing resistant starch solely (RS, fast fermentable fiber) and mixing with other fibers (xylan or cellulose). Twenty-four ileum-cannulated growing pigs were divided into four groups: one control group receiving saline ileal infusions and three experimental groups infused with RS, RS with xylan, or RS with cellulose. Fecal and plasma samples were analyzed for gut microbiota composition, short-chain fatty acids (SCFAs), and blood biochemistry. Results indicated no significant differences between the RS and control group for the microbiome and SCFA concentration (p > 0.05). However, RS combined with fibers, particularly xylan, resulted in enhanced and prolonged fermentation, marked by an increase in Blautia and higher lactate and acetate production (p < 0.05). In contrast, RS with cellulose infusion enriched bacterial diversity in feces (p < 0.05). Blood biochemistry parameters showed no significant differences across groups (p > 0.05), though a trend of increased glucose levels was noted in the treatment groups (p < 0.1). Overall, RS alone had a limited impact on the distal hindgut microbiota due to rapid fermentation in the proximal gut, whereas combining RS with other fibers notably improved gut microecology by extending the fermentation process.