The small peptide CEP1 and the NIN-like protein NLP1 regulate NRT2.1 to mediate root nodule formation across nitrate concentrations.

Legumes acquire fixed nitrogen (N) from the soil and through endosymbiotic association with diazotrophic bacteria. However, establishing and maintaining N2-fixing nodules are expensive for the host plant, relative to taking up N from the soil. Therefore, plants suppress symbiosis when N is plentiful and enhance symbiosis when N is sparse. Here, we show that the nitrate transporter MtNRT2.1 is required for optimal nodule establishment in Medicago truncatula under low-nitrate conditions and the repression of nodulation under high-nitrate conditions. The NIN-like protein (NLP) MtNLP1 is required for MtNRT2.1 expression and regulation of nitrate uptake/transport under low- and high-nitrate conditions. Under low nitrate, the gene encoding the C-terminally encoded peptide (CEP) MtCEP1 was more highly expressed, and the exogenous application of MtCEP1 systemically promoted MtNRT2.1 expression in a compact root architecture 2 (MtCRA2)-dependent manner. The enhancement of nodulation by MtCEP1 and nitrate uptake were both impaired in the Mtnrt2.1 mutant under low nitrate. Our study demonstrates that nitrate uptake by MtNRT2.1 differentially affects nodulation at low- and high-nitrate conditions through the actions of MtCEP1 and MtNLP1.

Identification of degradation products of brivaracetam using liquid chromatography quadrupole time-of-flight tandem mass spectrometry: Degradation pathway elucidation.

RATIONALE: Pyrrolidone-based drugs find widespread use in treating conditions such as epilepsy and Alzheimer's disease, and in various other medical applications. Brivaracetam, the latest generation of pyrrolidone drugs, has exhibited significant promise owing to chemical structure modifications. Its affinity to the SV2A receptor is double that of the previous-generation drug, levetiracetam. Consequently, brivaracetam holds substantial potential for diverse applications. As a novel drug not yet included in the pharmacopeias of developed nations, comprehensive analysis and research are necessary to guarantee its safe utilization in clinical settings. METHODS: A liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC/QTOFMS) method has been developed to effectively separate, identify and characterize both the degradation products and process-related substances of brivaracetam. Stress testing of the sample was carried out following the guidelines outlined in ICH Q1A(R2). The structures of these impurities were identified through positive electrospray ionization QTOF high-resolution MS and NMR spectroscopy. Additionally, the formation mechanism of each degradation product is thoroughly discussed. RESULTS: Under the analytical conditions outlined in this paper, brivaracetam and its degradation products were effectively separated. Thirteen degradation products were detected and characterized, shedding light on their origins and degradation pathways. Among these, three degradation products align with previously reported impurities, and two unreported degradation products were synthesized and confirmed through NMR spectroscopy. The stress testing results revealed the instability of brivaracetam under acidic, alkaline, oxidative and thermal stress conditions, while it exhibited relative stability under photolytic stress conditions. CONCLUSION: The study developed an analytical method for brivaracetam that enabled the effective detection and separation of brivaracetam and its 13 degradation products. This method addresses a gap in both current domestic and foreign drug standards. The structures of all the major degradation products were characterized by high-resolution LC/QTOFMS, which is essential for quality control during the drug production process, stability evaluation and the establishment of proper storage conditions.

Zirconium and cerium dioxide fabricated activated carbon-based nanocomposites for enhanced adsorption and photocatalytic removal of methylene blue and tetracycline hydrochloride.

Activated carbon (AC) is a porous, amorphous form of carbon known for its strong adsorption capacity, making it highly effective for use in wastewater treatment. In this investigation, AC-based nanocomposites (NCs) loaded with zirconium dioxide and cerium dioxide nanoparticles (ZrO2/CeO2 NPs) were successfully synthesized for the effective elimination of methylene blue (MB) and tetracycline hydrochloride (TCH). The AC-ZrO2/CeO2 NCs have a size of 231.83 nm, a zeta potential of -20.07 mV, and a PDI value of 0.160. The adsorption capacities of AC-ZrO2/CeO2 NCs for MB and TCH were proved in agreement with the Langmuir isotherm and pseudo 1st order kinetic model, respectively. The maximum adsorption capacities were determined to be 75.54 mg/g for MB and 26.75 mg/g for TCH. Notably, AC-ZrO2/CeO2 NCs exhibited superior photocatalytic degradation efficiency for MB and TCH under sunlight irradiation with removal efficiencies reaching up to 97.91% and 82.40% within 90 min, respectively. The t1/2 for the photo-degradation process of MB and TCH were 11.55 min and 44.37 min. Analysis of active species trapping confirmed the involvement of hole (h+), superoxide anion (•O2-), and hydroxyl radical (•OH) in the degradation mechanism. Furthermore, the residual solution post-contaminant removal exhibited minimal toxicity towards Artemia salina and NIH3T3 cells. Importantly, the NCs did not exhibit antibacterial activity against tested pathogens post-absorption/degradation of TCH. Thus, AC-ZrO2/CeO2 NCs could be a promising nanomaterial for wastewater treatment applications.

Quality Assessment of TikTok as a Source of Information About Mitral Valve Regurgitation in China: Cross-Sectional Study.

BACKGROUND: In China, mitral valve regurgitation (MR) is the most common cardiovascular valve disease. However, patients in China typically experience a high incidence of this condition, coupled with a low level of health knowledge and a relatively low rate of surgical treatment. TikTok hosts a vast amount of content related to diseases and health knowledge, providing viewers with access to relevant information. However, there has been no investigation or evaluation of the quality of videos specifically addressing MR. OBJECTIVE: This study aims to assess the quality of videos about MR on TikTok in China. METHODS: A cross-sectional study was conducted on the Chinese version of TikTok on September 9, 2023. The top 100 videos on MR were included and evaluated using quantitative scoring tools such as the modified DISCERN (mDISCERN), the Journal of the American Medical Association (JAMA) benchmark criteria, the Global Quality Score (GQS), and the Patient Education Materials Assessment Tool for Audio-Visual Content (PEMAT-A/V). Correlation and stepwise regression analyses were performed to examine the relationships between video quality and various characteristics. RESULTS: We obtained 88 valid video files, of which most (n=81, 92%) were uploaded by certified physicians, primarily cardiac surgeons, and cardiologists. News agencies/organizations and physicians had higher GQS scores compared with individuals (news agencies/organizations vs individuals, P=.001; physicians vs individuals, P=.03). Additionally, news agencies/organizations had higher PEMAT understandability scores than individuals (P=.01). Videos focused on disease knowledge scored higher in GQS (P<.001), PEMAT understandability (P<.001), and PEMAT actionability (P<.001) compared with videos covering surgical cases. PEMAT actionability scores were higher for outpatient cases compared with surgical cases (P<.001). Additionally, videos focused on surgical techniques had lower PEMAT actionability scores than those about disease knowledge (P=.04). The strongest correlations observed were between thumbs up and comments (r=0.92, P<.001), thumbs up and favorites (r=0.89, P<.001), thumbs up and shares (r=0.87, P<.001), comments and favorites (r=0.81, P<.001), comments and shares (r=0.87, P<.001), and favorites and shares (r=0.83, P<.001). Stepwise regression analysis identified "length (P<.001)," "content (P<.001)," and "physicians (P=.004)" as significant predictors of GQS. The final model (model 3) explained 50.1% of the variance in GQSs. The predictive equation for GQS is as follows: GQS = 3.230 - 0.294 × content - 0.274 × physicians + 0.005 × length. This model was statistically significant (P=.004) and showed no issues with multicollinearity or autocorrelation. CONCLUSIONS: Our study reveals that while most MR-related videos on TikTok were uploaded by certified physicians, ensuring professional and scientific content, the overall quality scores were suboptimal. Despite the educational value of these videos, the guidance provided was often insufficient. The predictive equation for GQS developed from our analysis offers valuable insights but should be applied with caution beyond the study context. It suggests that creators should focus on improving both the content and presentation of their videos to enhance the quality of health information shared on social media.

2-Deoxy-D-glucose ameliorates inflammation and fibrosis in a silicosis mouse model by inhibiting hypoxia-inducible factor-1α in alveolar macrophages.

Inhaling silica causes the occupational illness silicosis, which mostly results in the gradual fibrosis of lung tissue. Previous research has demonstrated that hypoxia-inducible factor-1α (HIF-1α) and glycolysis-related genes are up-regulated in silicosis. The role of 2-deoxy-D-glucose (2-DG) as an inhibitor of glycolysis in silicosis mouse models and its molecular mechanisms remain unclear. Therefore, we used 2-DG to observe its effect on pulmonary inflammation and fibrosis in a silicosis mouse model. Furthermore, in vitro cell experiments were conducted to explore the specific mechanisms of HIF-1α. Our study found that 2-DG down-regulated HIF-1α levels in alveolar macrophages induced by silica exposure and reduced the interleukin-1ß (IL-1ß) level in pulmonary inflammation. Additionally, 2-DG reduced silica-induced pulmonary fibrosis. From these findings, we hypothesize that 2-DG reduced glucose transporter 1 (GLUT1) expression by inhibiting glycolysis, which inhibits the expression of HIF-1α and ultimately reduces transcription of the inflammatory cytokine, IL-1ß, thus alleviating lung damage. Therefore, we elucidated the important regulatory role of HIF-1α in an experimental silicosis model and the potential defense mechanisms of 2-DG. These results provide a possible effective strategy for 2-DG in the treatment of silicosis.

Kelp as a biomonitor of persistent organic pollutants in coastal areas of China: Contamination levels and human health risk.

Kelp, the brown alga distributed in coastal areas all over the world, is also an important medicine food homology product in China. However, the levels and profiles of persistent organic pollutants (POPs) in kelp have not been thoroughly investigated to date. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and emerging bromine flame retardants (eBFRs) were evaluated in 41 kelp samples from the main kelp producing areas in China. The concentrations of total PCBs, PBDEs and eBFRs were in the range of 0.321-4.24 ng/g dry weight (dw), 0.255-25.5 ng/g dw and 3.00 × 10-3-47.2 ng/g dw in kelp, respectively. The pollutant pattern was dominated by decabromodiphenyl ethane (DBDPE, 13.0 ± 11.7 ng/g dw) followed in decreasing order by BDE-209 (2.74 ± 4.09 ng/g dw), CB-11 (1.32 ± 1.06 ng/g dw). The tested results showed that kelp could reflect the pollution status of PCBs, PBDEs and eBFRs, indicating the suitability of kelp as a biomonitor of these harmful substances. Finally, the data obtained was used to evaluate human non-cancer and cancer risks of PCBs and PBDEs via kelp consumption for Chinese. Though the calculated risk indices were considered acceptable according to the international standards even in the worst scenarios, the POPs levels in kelp should be monitored continuously as a good environmental indicator.

Characterisation and critical processes identification for production of herbal preparations using 1H-NMR and chemometrics: A case study of Trichosanthis Pericarpium injection.

INTRODUCTION: Herbal preparations are extensively utilised for the treatment of diseases in Asian countries. However, the variations in origin, climate, and production processes can lead to inconsistencies in the quality of herbal preparations. Existing quality control methods only target a few components in the finished product but ignore the control in the pharmaceutical process. Therefore, this study intends to develop a comprehensive component analysis method for intermediates in the pharmaceutical process to reveal the change patterns of substances and deepen the process understanding. OBJECTIVE: This study aims to develop a rapid and comprehensive process characterisation and critical process identification method for herbal preparations. METHODS: Six batches of Trichosanthis Pericarpium injection (TPI) intermediates were collected from the production process. Proton nuclear magnetic resonance (1H-NMR) spectra were acquired for qualitative and quantitative analysis of the se intermediates. Subsequently, chemometrics were used to identify critical processes and potential chemical markers. RESULTS: A total of 39 components in intermediates were identified, and the transfer of 25 components during the production process was investigated. Column chromatography was determined as the critical process. Nine components were identified as chemical markers. CONCLUSION: The application of 1H-NMR facilitated a comprehensive reflection of the chemical composition information of process intermediates, enabling investigations into the transfer of multi-component substances and accurate identification of critical processes and chemical markers.

Identification of Key Molecular Pathways and Associated Genes as Targets to Overcome Radiotherapy Resistance Using a Combination of Radiotherapy and Immunotherapy in Glioma Patients.

Recent mechanistic studies have indicated that combinations of radiotherapy (RT) plus immunotherapy (via CSF-1R inhibition) can serve as a strategy to overcome RT resistance and improve the survival of glioma mice. Given the high mortality rate for glioma, including low-grade glioma (LGG) patients, it is of critical importance to investigate the mechanism of the combination of RT and immunotherapy and further translate the mechanism from mouse studies to improve survival of RT-treated human glioma patients. Using the RNA-seq data from a glioma mouse study, 874 differentially expressed genes (DEGs) between the group of RT-treated mice at glioma recurrence and the group of mice with combination treatment (RT plus CSF-1R inhibition) were translated to the human genome to identify significant molecular pathways using the KEGG enrichment analysis. The enrichment analysis yields statistically significant signaling pathways, including the phosphoinositide 3-kinase (PI3K)/AKT pathway, Hippo pathway, and Notch pathway. Within each pathway, a candidate gene set was selected by Cox regression models as genetic biomarkers for resistance to RT and response to the combination of RT plus immunotherapies. Each Cox model is trained using a cohort of 295 RT-treated LGG patients from The Cancer Genome Atlas (TCGA) database and validated using a cohort of 127 RT-treated LGG patients from the Chinese Glioma Genome Atlas (CGGA) database. A four-DEG signature (ITGB8, COL9A3, TGFB2, JAG1) was identified from the significant genes within the three pathways and yielded the area under time-dependent ROC curve AUC = 0.86 for 5-year survival in the validation set, which indicates that the selected DEGs have strong prognostic value and are potential intervention targets for combination therapies. These findings may facilitate future trial designs for developing combination therapies for glioma patients.

Enhanced properties of a positive-charged nanofiltration membrane containing quaternarized chitosan through second interfacial polymerization for the removal of salts and pharmaceuticals.

Nanofiltration (NF) membrane technology has been widely used in the removal of salts and trace organic pollutants, such as pharmaceuticals and personal care products (PPCPs), due to its superiority. A positive-charged composite NF membrane with an active skin layer was prepared by polyethyleneimine (PEI), trimethyl benzene chloride, and quaternate chitosan (HTCC) through second interfacial polymerization on the polyethersulfone ultrafiltration membrane. The physicochemical properties of the nanocomposite membrane were investigated using surface morphology, hydrophilicity, surface charge, and molecular weight cut-off (MWCO). The influence of the concentration and reaction time of PEI and HTCC was documented. The optimized membrane had a MWCO of about 481 Da and possessed a pure water permeability of 25.37 L·m-2·h-1·MPa-1. The results also exhibited salt rejection ability as MgCl2 > CaCl2 > MgSO4 > Na2SO4 > NaCl > KCl, showing a positive charge on the fabricated membrane. In addition, the membrane had higher rejection to atenolol, carbamazepine, amlodipine, and ibuprofen at 89.46, 86.02, 90.12, and 77.21%, respectively. Moreover, the anti-fouling performance and stability of the NF membrane were also improved.

Infection of epithelioma papulosum cyprini (EPC) cells with spring viremia of carp virus (SVCV) induces autophagy and apoptosis through endoplasmic reticulum stress.

Spring viremia of carp virus (SVCV) is a lethal freshwater pathogen of cyprinid fish that has caused significant economic losses to aquaculture. To reduce the economic losses caused by SVCV, its pathogenic mechanism needs to be studied more thoroughly. Here, we report for the first time that SVCV infection of Epithelioma papulosum cyprini (EPC) cells can induce cellular autophagy and apoptosis through endoplasmic reticulum stress. The presence of autophagic vesicles in infected EPC cells was shown by transmission electron microscopy. Quantitative fluorescence PCR and Western blot results showed that p62 mRNA expression was decreased, and the expression of Beclin1 and LC3 mRNA was increased. The p62 protein was decreased, and the Beclin1 protein and LC3 were increased in the endoplasmic reticulum stress activation state. To further clarify the mode of death of SVCV-infected EPC cells, we examined caspase3, caspase9, BCL-2, and Bax mRNA, which showed that they were all increased. Apoptosis of SVCV-infected cells increased upon activation of endoplasmic reticulum stress. Our results suggest that endoplasmic reticulum stress can regulate SVCV infection-induced autophagy and apoptosis. The results of this study provide theoretical data for the pathogenesis of SVCV and lay the foundation for future drug development and vaccine construction.

Potential influence of fine aerosol chemistry on the optical properties in a semi-arid region.

The current understanding regarding the potential influence of aerosol chemistry on the optical properties does not satisfy accurate evaluation of aerosol radiative effects and precise determination of aerosol sources. We conducted a comprehensive study of the potential influence of aerosol chemistry on the optical properties in a semi-arid region based on various observations. Organic matter was the main contributor to the scattering coefficients followed by secondary inorganic aerosols in all seasons. We further related aerosol absorption to elemental carbon, organic matter, and mineral dust. Results showed that organic matter and mineral dust contributed to >40% of the aerosol absorption in the ultraviolet wavelengths. Therefore, it is necessary to consider the absorption of organic matter and mineral dust in addition to that of elemental carbon. We further investigated the potential influence of chemical composition, especially of organic matter and mineral dust on the optical parameters. Mineral dust contributed to higher absorption efficiency and lower scattering efficiency in winter. The absorption Ångström exponent (AAE) was mostly sensitive to organic matter and mineral dust in winter and spring, respectively; it was relatively high (i.e., 1.68) in winter and moderate (i.e., 1.42) in spring. Unlike in the other seasons, mineral dust contributed to higher mass absorption efficiency in winter. This work reveals the complexity of the relationship between aerosol chemistry and optical properties, and especially the influence of organic matter and mineral dust on aerosol absorption. The results are highly important regarding both regional air pollution and climate.

Toxicity of benzethonium chloride and polyhexamethylene guanidine hydrochloride mixtures on Daphnia carinata: synergistic and antagonistic effects at specific ratios.

Throughout the coronavirus (COVID-19) pandemic, the sanitizing products benzethonium chloride (BEC) and polyhexamethylene guanidine hydrochloride (PHMG-H) were widely used; however, few studies have investigated their combined toxicity to organisms. In the present study, acute toxicity and genotoxicity of BEC, PHMG-H, and the combination of the two were investigated as endpoints using Daphnia carinata as the model organism. For individual reagents, PHMG-H was found to be more toxic than BEC in terms of both mortality and genotoxicity. DNA damage and survival rate were used as toxicity endpoints. The interaction was evaluated with the concentration addition (CA) model via toxic unit (TU) approach and additive index (AI) method in mixtures at different ratios in TU. Only the binary mixture BEC + PHMG-H at the ratio 1:9 in TU was regarded as synergistic, while all others indicated increased antagonistic effects as the proportion of BEC increased over the PHMG-H concentration. The findings here benefit understanding surrounding precisely how BEC and PHMG-H interact at different mixing ratios, and can assist with the evaluation of risk assessments for binary mixtures in aquatic ecosystems.

A nomogram for predicting sepsis-associated delirium: a retrospective study in MIMIC III.

OBJECTIVE: To develop a nomogram for predicting the occurrence of sepsis-associated delirium (SAD). MATERIALS AND METHODS: Data from a total of 642 patients were retrieved from the Medical Information Mart for Intensive Care (MIMIC III) database to build a prediction model. Multivariate logistic regression was performed to identify independent predictors and establish a nomogram to predict the occurrence of SAD. The performance of the nomogram was assessed in terms of discrimination and calibration by bootstrapping with 1000 resamples. RESULTS: Multivariate logistic regression identified 4 independent predictors for patients with SAD, including Sepsis-related Organ Failure Assessment(SOFA) (p = 0.004; OR: 1.131; 95% CI 1.040 to 1.231), mechanical ventilation (P < 0.001; OR: 3.710; 95% CI 2.452 to 5.676), phosphate (P = 0.047; OR: 1.165; 95% CI 1.003 to 1.358), and lactate (P = 0.023; OR: 1.135; 95% CI 1.021 to 1.270) within 24 h of intensive care unit (ICU) admission. The area under the curve (AUC) of the predictive model was 0.742 in the training set and 0.713 in the validation set. The Hosmer - Lemeshow test showed that the model was a good fit (p = 0.471). The calibration curve of the predictive model was close to the ideal curve in both the training and validation sets. The DCA curve also showed that the predictive nomogram was clinically useful. CONCLUSION: We constructed a nomogram for the personalized prediction of delirium in sepsis patients, which had satisfactory performance and clinical utility and thus could help clinicians identify patients with SAD in a timely manner, perform early intervention, and improve their neurological outcomes.

Lactiplantibacillus plantarum LPJZ-658 Improves Non-Alcoholic Steatohepatitis by Modulating Bile Acid Metabolism and Gut Microbiota in Mice.

Non-alcoholic steatohepatitis (NASH) is one of the most prevalent diseases worldwide; it is characterized by hepatic lipid accumulation, inflammation, and progressive fibrosis. Here, a Western diet combined with low-dose weekly carbon tetrachloride was fed to C57BL/6J mice for 12 weeks to build a NASH model to investigate the attenuating effects and possible mechanisms of Lactiplantibacillus plantarum LPJZ-658. Hepatic pathology, lipid profiles, and gene expression were assessed. The metabolomic profiling of the serum was performed. The composition structure of gut microbiota was profiled using 16s rRNA sequencing. The results show that LPJZ-658 treatment significantly attenuated liver injury, steatosis, fibrosis, and inflammation in NASH mice. Metabolic pathway analysis revealed that several pathways, such as purine metabolism, glycerophospholipid metabolism, linoleic acid metabolism, and primary bile acid biosynthesis, were associated with NASH. Notably, we found that treatment with LPJZ-658 regulated the levels of bile acids (BAs) in the serum. Moreover, LPJZ-658 restored NASH-induced gut microbiota dysbiosis. The correlation analysis deduced obvious interactions between BAs and gut microbiota. The current study indicates that LPJZ-658 supplementation protects against NASH progression, which is accompanied by alternating BA metabolic and modulating gut microbiota.

Generation, mechanisms, kinetics, and effects of gaseous chlorine dioxide in food preservation.

Food preservation is a critical issue in ensuring food safety and quality. Growing concern around industrial pollution of food and demand for environmentally sustainable food has led to increased interest in developing effective and eco-friendly preservation techniques. Gaseous ClO2 has gained attention for its strong oxidizing properties, high efficacy in microorganism inactivation, and potential for preserving the attributes and nutritional quality of fresh food while avoiding the formation of toxic byproducts or unacceptable levels of residues. However, the widespread use of gaseous ClO2 in the food industry is limited by several challenges. These include large-scale generation, high cost and environmental considerations, a lack of understanding of its mechanism of action, and the need for mathematical models to predict inactivation kinetics. This review aims to provide an overview of the up-to-date research and application of gaseous ClO2 . It covers preparation methods, preservation mechanisms, and kinetic models that predict the sterilizing efficacy of gaseous ClO2 under different conditions. The impacts of gaseous ClO2 on the quality attributes of fresh produce and low-moisture foods, such as seeds, sprouts, and spices, are also summarized. Overall, gaseous ClO2 is a promising preservation approach, and future studies are needed to address the challenges in large-scale generation and environmental considerations and to develop standardized protocols and databases for safe and effective use in the food industry.

Application of the metal ions as potential population biomarkers for wastewater-based epidemiology: estimating tobacco consumption in Southern China.

Wastewater-based epidemiology (WBE) is an objective approach for the estimation of population-level exposure to a wide range of substances, in which the use of a population biomarker (PB) could significantly reduce back-calculation errors. Although some endogenous or exogenous compounds such as cotinine and other hormones have been developed as PBs, more PBs still need to be identified and evaluated. This study aimed to propose a novel method to estimate population parameters from the mass load of metal ion biomarkers in wastewater, and estimate the consumption of tobacco in 24 cities in Southern China using the developed method. Daily wastewater samples were collected from 234 wastewater treatment plants (WWTPs) in 24 cities in Southern China. Atomic absorption spectroscopy (AAS) was applied to determine the concentrations of common health-related metal ions in wastewater, including sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), and zinc (Zn), and compared them with the daily mass load of cotinine corresponding to catchment populations. The concentrations of cotinine in wastewater samples were measured using liquid chromatography-tandem mass spectrometry. There were clear and strong correlations between the target metal ion equivalent population and census data. The correlation coefficients (R) were RK = 0.78, RNa = 0.66, RCa = 0.81, RMg = 0.77, and RFe = 0.69, at p < 0.01 and R2 > 0.6. Subsequently, the combination of WBE and metal ion PBs was used to estimate tobacco consumption. Daily consumption of nicotine was estimated to be approximately 1.76 ± 1.19 mg/d/capita, equivalent to an average of 13.0 ± 8.75 cigarettes/d being consumed by smokers. The data on tobacco consumption in this study were consistent with those in traditional surveys in Southern China. The metal ion potassium is an appropriate PB for reflecting the real-time population and could be used to evaluate the tobacco consumption in WBE study.

Comparison of gut microbial communities, free amino acids or fatty acids contents in the muscle of wild Aristichthys nobilis from Xinlicheng reservoir and Chagan lake.

BACKGROUND: Fish is favored by consumers, while amino acids and fatty acids are the main nutrients of muscle. At present, it has been found that the gut microbial community may be involved in the regulation of host material anabolism. Juvenile and adult bighead carp (A. nobilis) from Chagan lake and Xinlicheng reservoir were selected, and divided into four groups to compare the differences of gut microbial communities, free amino acid and fatty acids in muscle. RESULTS: The results showed that fish in different lakes or ages contained specific microbiota, the gut microbial structure was similar, but the microbial content was significantly different. Gut microbial abundance of juvenile fish in Chagan lake was significantly higher than that of other groups. Phylum level analysis Proteobacteria was the dominant gut bacteria of fish in both adult and juvenile fish from two separate lakes. Actinobacteria was another dominant bacterial phylum in juvenile fish in both lakes. Contents of free amino acids and fatty acids in muscle were detected, and the relationships between them and gut microbial communities were analyzed. Bighead carp grew from juvenile to adult, Actinobacteria abundance decreased (P < 0.05) and Proteobacteria increased (P < 0.05). Proteobacteria was positively correlated with the contents of Thr, Lys, Pro, Asp, Gly and Glu, Actinobacteria was negatively correlated with Met and His. Meanwhile, EPA and DHA were positively correlated with Proteobacteria, EPA and DHA were not significantly associated with Actinobacteria. CONCLUSION: It was speculated that the contents of free amino acids and fatty acids in muscle might be affected by the difference of gut microbiota, thus affecting the taste and nutritional quality.

Separation and identification of ACE inhibitory peptides from lizard fish proteins hydrolysates by metal affinity-immobilized magnetic liposome.

Purification of peptides responsible for angiotensin I-converting enzyme (ACE) inhibitory activity from highly complex protein hydrolysates is difficult. Affinity chromatography is a powerful method for purification of peptides. In this study, a metal affinity-immobilized magnetic liposome (MA-IML) was prepared using lipid, N-hexadecyl iminodiacetic acid (HIDA) and magnetic nanoparticles made of FeCl3·6H2O and FeCl2·4H2O as main materials. MA-IML was used to adsorb ACE inhibitory peptides from lizard fish proteins hydrolysates. The optimal pH of adsorption solution was 8.5. The peptide sample adsorbed by MA-IML was separated by reverse phase-high performance liquid chromatography (RP-HPLC). Upon amino acid sequence analysis and verification, an ACE inhibitory peptide with IC50 value of 108 µM was identified to be VYP. Molecular docking results indicated that VYP bound to ACE via multiple binding sites. The present study demonstrated that MA-IML might be a useful tool for separating ACE inhibitory peptides from proteins hydrolysates.

Characterization of structurally related peptide impurities using HPLC-QTOF-MS/MS: application to Cbf-14, a novel antimicrobial peptide.

Cbf-14 (RLLRKFFRKLKKSV), a designed antimicrobial peptide derived from the cathelicidin family, is effective against drug-resistant bacteria. Structurally related peptide impurities in peptide medicines probably have side effects or even toxicity, thus impurity profiling research during the entire production process is indispensable. In this study, a simple liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method using a quadrupole time-of-flight (Q-TOF) mass spectrometer was developed for separation, identification, and characterization of structurally related peptide impurities in Cbf-14. A total of one process-related impurity and thirty-two degradation products were identified, and seven of them have been synthesized and confirmed. These impurities have not been declared in custom synthetic peptides. The degradation products were divided into five categories: fifteen Cbf-14 hydrolysates, five Cbf-14 isomers, four acetyl-Cbf-14 isomers, two aldimine derivatives, and six oxidized impurities. Combined with the peptide synthesis and the stress-testing studies, the origins and the formation mechanisms of these impurities were elucidated, which provides a unique insight for the follow-up quality study of Cbf-14 and other peptide products.

Simultaneous determination of nirmatrelvir and ritonavir in human plasma using LC-MS/MS and its pharmacokinetic application in healthy Chinese volunteers.

Paxlovid, a copackaged medication of nirmatrelvir tablets (150 mg) and ritonavir tablets (100 mg) developed by Pfizer, is one of the first orally accessible COVID-19 antiviral medicines to be approved for emergency usage. In this research, an efficient LC-MS/MS method for simultaneous determination of nirmatrelvir and ritonavir in human plasma was established and validated with remdesivir as an internal standard. Chromatographic separations were carried out on a Thermo BDS Hypersil C18 column (4.6 × 100 mm, 2.4 µm) using deionized water and methanol as mobile phase, both added with 0.1% (v/v) formic acid. Based on the positive electrospray ionization mode, nirmatrelvir and ritonavir were analyzed by selective reaction monitoring. Excellent precision, accuracy, recovery, and linearity were demonstrated, covering the range of 50-5000 ng/mL for nirmatrelvir and 10-1000 ng/mL for ritonavir. Then, the established method was used for determining the pharmacokinetic profile of Paxlovid in healthy Chinese volunteers. The pharmacokinetic parameters, including Cmax , Tmax , t1/2 , and AUC0 - ∞ of Western volunteers, correspond well with the results of this pharmacokinetic investigation.