mEnrich-seq: methylation-guided enrichment sequencing of bacterial taxa of interest from microbiome.

Metagenomics has enabled the comprehensive study of microbiomes. However, many applications would benefit from a method that sequences specific bacterial taxa of interest, but not most background taxa. We developed mEnrich-seq (in which 'm' stands for methylation and seq for sequencing) for enriching taxa of interest from metagenomic DNA before sequencing. The core idea is to exploit the self versus nonself differentiation by natural bacterial DNA methylation and rationally choose methylation-sensitive restriction enzymes, individually or in combination, to deplete host and background taxa while enriching targeted taxa. This idea is integrated with library preparation procedures and applied in several applications to enrich (up to 117-fold) pathogenic or beneficial bacteria from human urine and fecal samples, including species that are hard to culture or of low abundance. We assessed 4,601 bacterial strains with mapped methylomes so far and showed broad applicability of mEnrich-seq. mEnrich-seq provides microbiome researchers with a versatile and cost-effective approach for selective sequencing of diverse taxa of interest.

Discovering multiple types of DNA methylation from bacteria and microbiome using nanopore sequencing.

Bacterial DNA methylation occurs at diverse sequence contexts and plays important functional roles in cellular defense and gene regulation. Existing methods for detecting DNA modification from nanopore sequencing data do not effectively support de novo study of unknown bacterial methylomes. In this work, we observed that a nanopore sequencing signal displays complex heterogeneity across methylation events of the same type. To enable nanopore sequencing for broadly applicable methylation discovery, we generated a training dataset from an assortment of bacterial species and developed a method, named nanodisco ( https://github.com/fanglab/nanodisco ), that couples the identification and fine mapping of the three forms of methylation into a multi-label classification framework. We applied it to individual bacteria and the mouse gut microbiome for reliable methylation discovery. In addition, we demonstrated the use of DNA methylation for binning metagenomic contigs, associating mobile genetic elements with their host genomes and identifying misassembled metagenomic contigs.

Asymmetric adhesive SIS-based wound dressings for therapeutically targeting wound repair.

Severe tissue injuries pose a significant risk to human health. Conventional wound dressings fall short in achieving effective tissue regeneration, resulting in suboptimal postoperative healing outcomes. In this study, an asymmetric adhesive wound dressing (marked as SIS/PAA/LAP) was developed, originating from acrylate acid (AA) solution with laponite (LAP) nanoparticles polymerization and photo-crosslinked on the decellularized extracellular matrix small intestinal submucosa (SIS) patch. Extensive studies demonstrated that the SIS/PAA/LAP exhibited higher tissue adhesion strength (~ 33 kPa) and burst strength (~ 22 kPa) compared to conventional wound dressings like Tegaderm and tissue adhesive products. Importantly, it maintained favorable cell viability and demonstrated robust angiogenic capacity. In animal models of full-thickness skin injuries in rats and skin injuries in Bama miniature pigs, the SIS/PAA/LAP could be precisely applied to wound sites. By accelerating the formation of tissue vascularization, it displayed superior tissue repair outcomes. This asymmetrically adhesive SIS-based patch would hold promising applications in the field of wound dressings.

Simplified Chinese version of the core outcome measures index (COMI) for patients with neck pain: cross-cultural adaptation and validation.

PURPOSE: The aim of this study was to translate and cross-culturally adapt the Core Outcome Measures Index for (COMI) into a Simplified Chinese version (COMI-SC) and to evaluate the reliability and validity of COMI-SC in patients with neck pain. METHODS: The COMI-neck was translated into Chinese according to established methods. The COMI-neck questionnaire was then completed by 122 patients with a hospital diagnosis of neck pain. Reliability was assessed by calculating Cronbach's alpha and intraclass correlation coefficient (ICC). Construct validity was assessed by correlating the COMI-neck with the Neck Pain and Disability Scale (NPDS), the Neck Disability Index (NDI), the VAS and the Short Form (36) Health Survey (SF-36). Using confirmatory factor analysis to validate the structural, convergent and discriminant validity of the questionnaire. RESULTS: The COMI-neck total scores were well distributed, with no floor or ceiling effects. Internal consistency was excellent (Cronbach's alpha = 0.861). Moderate to substantial correlations were found between COMI-neck and NPDS (r = 0.420/0.416/0.437, P < 0.001), NDI (r = 0.890, P < 0.001), VAS (r = 0.845, P < 0.001), as well as physical function (r = - 0.989, P < 0.001), physical role (r = - 0.597, P < 0.001), bodily pain (r = - 0. 639, P < 0.001), general health (r = - 0.563, P < 0.001), vitality (r = - 0.702, P < 0.001), social functioning (r = - 0.764, P < 0.001), role emotional (r = - 0.675, P < 0.001) and mental health (r = - 0.507, P < 0.001) subscales of the SF-36. An exploratory factor analysis revealed that the 3-factor loading explained 71.558% of the total variance [Kaiser-Mayer-Olkin (KMO) = 0.780, C2 = 502.82, P < 0.001]. CMIN/DF = 1.813, Tucker-Lewis index (TLI) = 0.966 (> 0.9), Comparative Fit Index (CFI) = 0.982 (> 0.9), Normed Fit Index (NFI) = 0.961 (> 0.9), RMSEA = 0.082 (< 0.5) indicating that the model fits well. CONCLUSION: COMI-neck was shown to have acceptable reliability and validity in patients with non-specific chronic neck pain and could be recommended for patients in mainland China. LEVEL OF EVIDENCE: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Responses of precipitation and water vapor budget on the Chinese Loess Plateau to global land cover change forcing.

There have been notable changes in precipitation patterns on the Loess Plateau (LP) of China in recent decades, and numerous attribution studies have focused on sea surface temperature anomalies and atmospheric circulation changes induced by aerosols and greenhouse gases emission. However, the influences of global land use and land cover change (LULCC) as an important forcing factor in the climate system on regional precipitation remains poorly understood. In this study, we quantified the impacts of LULCC on precipitation and the water vapor budget in the LP region, utilizing data from LULCC forcing experiments conducted by the sixth phase of the Coupled Model Intercomparison Project (CMIP6). Although global LULCC forcing exerted a negative effect on long-term mean precipitation on the LP region from 1850 to 2014, the different response characteristics were detected during different time periods. The global LULCC caused a decrease of 14 mm in annual precipitation during the period of 1850-1960. Conversely, from 1961 to 2014, it led to an increase of 6.4 mm, which is largely attributed to the enhanced water vapor transport along the southern boundary and westerly belt of the LP region. Moreover, from the perspective of the net water vapor balance of the entire LP, although LULCC caused net water vapor export during both periods 1850-1960 and 1961-2014, the export during the latter period (0.20 × 104 kg s-1) was smaller than that during the former period (0.28 × 104 kg s-1), indicating that the global expansion of grassland and cropland, along with the continuous rise in the leaf area index from 1961 to 2014, contributed to retaining more water vapor within the LP, which in turn was more favorable for precipitation. These findings provide valuable insights into the reasons behind precipitation variations in the LP region, emphasizing that global vegetation restoration and greening play a significant role in improving precipitation in ecologically fragile areas.

[Determination of 11 nutrients in liquid milk by ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish an ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method for simultaneous determination of 11 nutritional components(thiamine, riboflavin, nicotinamide, nicotinic acid, pantothenic acid, pyridoxine, pyridoxal, pyridoxamine, biotin, choline, L-carnitine) in liquid milk. METHODS: Milk samples were shaken with 20 mmol/L ammonium formate solution and heated in a water bath at 100 ℃ for 30 min, then incubated with papain and acid phosphatase at 45 ℃ for 16 h, the lower liquid was collected after centrifugation for analysis. UPLC separation was performed on an ACQUITY~(TM) HSS T3(3.0 mm×150 mm, 1.8 µm) column, 2 mmol/L ammonium formate(containing 0.1% formic acid) solution and acetonitrile(containing 0.1% formic acid) were used as mobile phase. Quantitative detection was performed by internal standard method. RESULTS: 11 nutritional components can be effectively separated and detected in 12 min, and the linear correlation coefficients(R~2) were all above 0.995. The limits of detection(LODs) were between 0.05 and 0.50 µg/L, and the limits of quantification(LOQs) were between 0.20 and 1.25 µg/L. The recovery rates of three-level addition were 85.6%-119.3%, and the precision RSDs were between 3.68% and 7.82%(n=6). Based on the detection of 60 liquid milk samples from 5 different animals, it was found that the contents of 11 nutrients in liquid milk from different milk sources were significantly different, but pyridoxine could not be detected. CONCLUSION: The method can quantitatively detect 11 water-soluble nutrients, including free and bound forms, by effective enzymolysis. It is sensitive, reproducible and can meet the needs of quantitative detection.

Combined transcriptomic and metabolomic analyses of high temperature stress response of quinoa seedlings.

BACKGROUND: Quinoa (Chenopodium quinoa Willd.) originates in high altitude areas, such as the Andes, and has some inherent characteristics of cold, drought, and salinity tolerance, but is sensitive to high temperature. RESULTS: To gain insight into the response mechanism of quinoa to high temperature stress, we conducted an extensive targeted metabolomic study of two cultivars, Dianli-3101 and Dianli-3051, along with a combined transcriptome analysis. A total of 794 metabolites and 54,200 genes were detected, in which the genes related to photosynthesis were found down-regulated at high temperatures, and two metabolites, lipids and flavonoids, showed the largest changes in differential accumulation. Further analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and transcription factors revealed that quinoa inhibits photosynthesis at high temperatures, and the possible strategies being used for high temperature stress management are regulation of heat stress transcription factors (HSFs) to obtain heat tolerance, and regulation of purine metabolism to enhance stress signals for rapid response to high temperature stress. The tolerant genotype could have an enhanced response through lower purine levels. The induction of the stress response could be mediated by HSF transcription factors. The results of this study may provide theoretical references for understanding the response mechanism of quinoa to high temperature stress, and for screening potential high temperature tolerant target genes and high temperature tolerant strains. CONCLUSIONS: These findings reveal the regulation of the transcription factor family HSF and the purinergic pathway in response to high temperature stress to improve quinoa varieties with high temperature tolerance.

AI-dente: an open machine learning based tool to interpret nano-indentation data of soft tissues and materials.

Nano-indentation is a promising method to identify the constitutive parameters of soft materials, including soft tissues. Especially when materials are very small and heterogeneous, nano-indentation allows mechanical interrogation where traditional methods may fail. However, because nano-indentation does not yield a homogeneous deformation field, interpreting the resulting load-displacement curves is non-trivial and most investigators resort to simplified approaches based on the Hertzian solution. Unfortunately, for small samples and large indentation depths, these solutions are inaccurate. We set out to use machine learning to provide an alternative strategy. We first used the finite element method to create a large synthetic data set. We then used these data to train neural networks to inversely identify material parameters from load-displacement curves. To this end, we took two different approaches. First, we learned the indentation forward problem, which we then applied within an iterative framework to identify material parameters. Second, we learned the inverse problem of directly identifying material parameters. We show that both approaches are effective at identifying the parameters of the neo-Hookean and Gent models. Specifically, when applied to synthetic data, our approaches are accurate even for small sample sizes and at deep indentation. Additionally, our approaches are fast, especially compared to the inverse finite element approach. Finally, our approaches worked on unseen experimental data from thin mouse brain samples. Here, our approaches proved robust to experimental noise across over 1000 samples. By providing open access to our data and code, we hope to support others that conduct nano-indentation on soft materials.

Periostin-targeted SDSSD peptide decorated calcium phosphate nanocomposites incorporation with simvastatin for osteoporosis treatment.

The limited options of anabolic drugs restrict their application potential in osteoporosis treatment, despite their theoretical superiority in therapeutic efficacy over antiresorptive drugs. As a prevailing strategy, nano-delivery systems could offer a wider choice of anabolic drugs. In this study, calcium phosphate nanocomposites incorporated with simvastatin (Sim) with periostin-targeting ability were designed and prepared for osteoporosis treatment. Carboxymethyl dextran (CMD) as an anionic and hydrophilic dextran derivative was used to stabilize CaP. In addition, periosteum-targeted peptide (SDSSD) was further grafted on CMD to achieve the bone targeting function. In a one-step coordination assembly strategy, hydrophobic anabolic agent Sim and SDSSD-CMD graft (SDSSD-CMD) were incorporated into the CaP nanoparticles forming SDSSD@CaP/Sim nanocomposites. The resulting SDSSD@CaP/Sim possesses uniform size, great short-term stability and excellent biocompatibility. Moreover, SDSSD@CaP/Sim exhibited a reduced release rate of Sim and showed slow-release behaviour. As anticipated, the nanocomposites exhibited bone bonding capacity in both cellular and animal studies. Besides, SDSSD@CaP/Sim achieved obviously enhanced osteoporosis treatment effect compared to direct injection of Simin vivo. Therefore, our findings highlight the potential of SDSSD-incorporated and CaP-based nanocomposites as a viable strategy to enhance the therapeutic efficacy of anabolic drugs for osteoporosis treatment.

Efficacy and safety of remimazolam tosilate versus propofol in patients undergoing day surgery: a prospective randomized controlled trial.

BACKGROUND: Remimazolam tosilate (RT) is a novel short-acting GABA (A) receptor agonist that has a rapid recovery from procedural sedation and can be fully reversed by flumazenil. To date, there have been relatively few articles comparing RT and propofol for general anesthesia. This study aimed to assess the efficacy and safety of RT with or without flumazenil compared with propofol in general anesthesia for day surgery. METHODS: 115 patients scheduled for day surgery were randomized into three groups: RT (n = 39), RT + flumazenil (n = 38) and propofol (n = 38). The primary endpoints were anesthesia induction time and time until fully alert. Anesthesia success rate, bispectral index (BIS) values, injection pain, opioid and vasopressor dosages, postoperative recovery profiles and perioperative inflammatory and cognitive changes were assessed. Any adverse events were recorded. RESULTS: Induction times were similar among the three groups (P = 0.437), but the median time until fully alert in patients treated with RT was longer than that of the propofol or RT + flumazenil groups (17.6 min vs. 12.3 min vs. 12.3 min, P < 0.001). The three groups had comparable postoperative recovery quality and inflammatory and cognitive state changes (P > 0.05). Smaller percentages of patients who received RT (26.3%) and RT + flumazenil (31.6%) developed hypotension during anesthesia maintenance compared with propofol (68.4%), and consequently less ephedrine (P < 0.001) and phenylephrine (P = 0.015) were needed in the RT group. Furthermore, serum triglyceride levels were lower (P < 0.001) and injection pain was much less frequent in the RT with or without flumazenil groups compared with the propofol group (5.3% vs. 0% vs. 18.4%). CONCLUSION: RT permits rapid induction and comparable recovery profile compared with propofol in general anesthesia for day surgery, but has a prolonged recovery time without flumazenil. The safety profile of RT was superior to propofol in terms of hypotension and injection pain. TRIAL REGISTRATION: The study was registered at Chinese Clinical Trial Registry http://www.chictr.org.cn/ (Registration date: 19/7/2021; Trial ID: ChiCTR2100048904).

Identifying Genetic Signatures Associated with Oncogene-Induced Replication Stress in Osteosarcoma and Screening for Potential Targeted Drugs.

Osteosarcoma is the most common type of primary malignant bone tumor. Due to the lack of selectivity and sensitivity of chemotherapy drugs to tumor cells, coupled with the use of large doses, chemotherapy drugs often have systemic toxicity. The use of modern sequencing technology to screen tumor markers in a large number of tumor samples is a common method for screening highly specific and selective anti-tumor drugs. This study aims to identify potential biomarkers using the latest reported gene expression signatures of oncogene-induced replication stress (ORS) in aggressive cancers, and potential anti-osteosarcoma drugs were screened in different drug databases. In this study, we obtained 89 osteosarcoma-related samples in the TARGET database, all of which included survival information. According to the median expression of each of six reported ORS gene markers (NAT10/DDX27/ZNF48/C8ORF33/MOCS3/MPP6), we divided 89 osteosarcoma gene expression datasets into a high expression group and a low expression group and then performed a differentially expressed gene (DEG) analysis. The coexisting genes of 6 groups of DEGs were used as replication stress-related genes (RSGs) of osteosarcoma. Then, key RSGs were screened using LASSO regression, a Cox risk proportional regression prognostic model and a tenfold cross-validation test. GSE21257 datasets collected from the Gene Expression Omnibus (GEO) database were used to verify the prognostic model. The final key RSGs selected were used in the L1000PWD and DGIdb databases to mine potential drugs. After further validation by the prognostic model, we identified seven genes associated with ORS in osteosarcoma as key RSGs, including transcription factor 7 like 2 (TCF7L2), solute carrier family 27 member 4 (SLC27A4), proprotein convertase subtilisin/kexin type 5 (PCSK5), nucleolar protein 6 (NOL6), coiled-coil-coil-coil-coil-helix domain containing 4 (CHCHD4), eukaryotic translation initiation factor 3 subunit B (EIF3B), and synthesis of cytochrome C oxidase 1 (SCO1). Then, we screened the seven key RSGs in two drug databases and found six potential anti-osteosarcoma drugs (D GIdb database: repaglinide, tacrolimus, sirolimus, cyclosporine, and hydrochlorothiazide; L1000PWD database: the small molecule VU-0365117-1). Seven RSGs (TCF7L2, SLC27A4, PCSK5, NOL6, CHCHD4, EIF3B, and SCO1) may be associated with the ORS gene signatures in osteosarcoma. Repaglinide, tacrolimus, sirolimus, cyclosporine, hydrochlorothiazide and the small molecule VU-0365117-1 are potential therapeutic drugs for osteosarcoma.

HMGB 1 acetylation mediates trichloroethylene-induced immune kidney injury by facilitating endothelial cell-podocyte communication.

More and more clinical evidence shows that occupational medicamentose-like dermatitis due to trichloroethylene (OMDT) patients often present immune kidney damage. However, the exact mechanisms of cell-to-cell transmission in TCE-induced immune kidney damage remain poorly understood. The present study aimed to explore the role of high mobility group box-1 (HMGB 1) in glomerular endothelial cell-podocyte transmission. 17 OMDT patients and 34 controls were enrolled in this study. We observed that OMDT patients had renal function injury, endothelial cell activation and podocyte injury, and these indicators were associated with serum HMGB 1. To gain mechanistic insight, a TCE-sensitized BALB/c mouse model was established under the interventions of sirtuin 1 (SIRT 1) activator SRT 1720 (0.1 ml, 5 mg/kg) and receptor for advanced glycation end products (RAGE) inhibitor FPS-ZM 1 (0.1 ml, 1.5 mg/kg). We identified HMGB 1 acetylation and its endothelial cytoplasmic translocation following TCE sensitization, but SRT 1720 abolished the process. RAGE was located on podocytes and co-precipitated with extracellular acetylated HMGB 1, promoting podocyte injury, while SRT 1720 and FPS-ZM 1 both alleviated podocyte injury. The results demonstrate that interventions to upstream and downstream pathways of HMGB 1 may weaken glomerular endothelial cell-podocyte transmission, thereby alleviating TCE-induced immune renal injury.

Clostridium butyricum Can Promote Bone Development by Regulating Lymphocyte Function in Layer Pullets.

Bone health problems are a serious threat to laying hens; microbiome-based therapies, which are harmless and inexpensive, may be an effective solution for bone health problems. Here, we examined the impacts of supplementation with Clostridium butyricum (CB) on bone and immune homeostasis in pullets. The results of in vivo experiments showed that feeding the pullets CB was beneficial to the development of the tibia and upregulated the levels of the bone formation marker alkaline phosphatase and the marker gene runt-related transcription factor 2 (RUNX2). For the immune system, CB treatment significantly upregulated IL-10 expression and significantly increased the proportion of T regulatory (Treg) cells in the spleen and peripheral blood lymphocytes. In the in vitro test, adding CB culture supernatant or butyrate to the osteoblast culture system showed no significant effects on osteoblast bone formation, while adding lymphocyte culture supernatant significantly promoted bone formation. In addition, culture supernatants supplemented with treated lymphocytes (pretreated with CB culture supernatants) stimulated higher levels of bone formation. In sum, the addition of CB improved bone health by modulating cytokine expression and the ratio of Treg cells in the immune systems of layer pullets. Additionally, in vitro CB could promote the bone formation of laying hen osteoblasts through the mediation of lymphocytes.

Integrated Metabolome and Transcriptome Analyses Reveal Amino Acid Biosynthesis Mechanisms during the Physiological Maturity of Grains in Yunnan Hulled Wheat (Triticum aestivum ssp. yunnanense King).

Yunnan hulled wheat (YHW) possesses excellent nutritional characteristics; however, the precise amino acid (AA) composition, contents, and molecular mechanisms underlying AA biosynthesis in YHW grains remain unclear. In this study, we aimed to perform metabolomic and transcriptomic profiling to identify the composition and genetic factors regulating AA biosynthesis during the physiological maturation of grains of two YHW genotypes, Yunmai and Dikemail, with high and low grain protein contents, respectively. A total of 40 and 14 differentially accumulated amino acids (AAs) or AA derivatives were identified between the waxy grain (WG) and mature grain (MG) phenological stages of Yunmai and Dikemail, respectively. The AA composition differed between WG and MG, and the abundance of AAs-especially that of essential AAs-was significantly higher in WG than in MG (only 38.74-58.26% of WG). Transcriptome analysis revealed differential regulation of structural genes associated with the relatively higher accumulation of AAs in WG. Weighted gene co-expression network analysis and correlation analyses of WG and MG indicated differences in the expression of clusters of genes encoding both upstream elements of AA biosynthesis and enzymes that are directly involved in AA synthesis. The expression of these genes directly impacted the synthesis of various AAs. Together, these results contribute to our understanding of the mechanism of AA biosynthesis during the different developmental stages of grains and provide a foundation for further research to improve the nutritional value of wheat products.

Research Progress in Nanofluid-Enhanced Oil Recovery Technology and Mechanism.

Nanofluid-enhanced oil recovery (EOR) technology is an innovative approach to enhancing oil production in oilfields. It entails the dispersion of nanoparticles within a fluid, strategically utilizing the distinctive properties of these nanoparticles (NPs) to engage with reservoir rocks or crude oil, resulting in a significant enhancement of the oil recovery rate. Despite the notable advantages of nanofluid EOR technology over conventional oil recovery methods such as binary and ternary flooding, practical implementations continue to grapple with a range of pressing challenges. These challenges encompass concerns regarding the economic viability, stability, and adaptability of nanomaterials, which pose significant barriers to the widespread adoption of nanofluid EOR technology in the oil field. To tackle these challenges, addressing the current issues may involve selecting simpler and more readily available materials coupled with straightforward material modification techniques. This approach aims to more effectively meet the requirements of large-scale on-site applications. Within this framework, this review systematically explores commonly employed nanofluids in recent years, including inorganic nanofluids, organic nanofluids, and composite nanofluids. It categorizes the research advancements in optimizing modification techniques and provides a comprehensive overview of the mechanisms that underpin nanofluid EOR technology and its practical applications in oilfields. This comprehensive review aims to offer valuable references and serve as a solid foundation for subsequent research endeavors.

[Investigation on the addition of dietary fiber in infant and follow-up formula in China from 2017 to 2022].

OBJECTIVE: To investigate the addition of dietary fiber in infant formula approved in recent 5 years. METHODS: A total of 1438 infant formula milk powder approved in China from January 2017 to June 2022 were collected and the addition rate, content and mixture of dietary fiber components such as galactooligosaccharide(FOS), fructooligosaccharide(GOS), polyfructose, polyglucose, raffinose and yeast ß-dextran were statistically analyzed. RESULTS: Among the 1438 infant formulas, 84.07%(1209) were added with dietary fiber, and the addition rate increased yearly. Among them, the addition rate of GOS(79.82%) and FOS(79.74%) was the highest, and the median amount of dietary fiber components was 3.00 g/100 g. Among the products added with various dietary fiber components, there were 762 products added with GOS and FOS, The addition ratios of GOS and FOS were mainly concentrated at 1∶1. CONCLUSION: The addition rate of dietary fiber in infant formula milk powder in China is constantly increasing, however there are large differences in the addition amount, dietary fiber combination and proportion of different products.

[Comparative study on the essential composition content of commercial follow-up formula for older infant with the requirements in the new national food safety standard in China from 2017 to 2022].

OBJECTIVE: To understand the distribution of the content range of essential ingredients in commercial follow-up formula for older infants in China, analyze the differences between the content of essential ingredients in commercial older infant formula milk powder in China and the requirements of the new national standard(GB 10766-2021). METHODS: The label information of 478 commercial follow-up formula for older infant registered and approved from January 2017 to June 2022 were collected and entered. The distribution of essential ingredients was statistically analyzed, which was compared with the requirements of the new national food safety standard. RESULTS: The new national standard has 31 essential components. Compared with the old national standard(GB 10767-2010), five indicators of carbohydrate, α-linolenic acid, choline, selenium and manganese were added. The new national standard has 28 essential component requirements revised, including 13 adjusted the lower limit, 7 adjusted the upper limit, and 16 essential components added the upper limit. Among the approved 478 older infant formula milk powders, the distribution of 11 essential ingredients were all in line with the new national standard, and 14 essential ingredients were less than the lower limit of the new national standard. The essential ingredients whose minimum value was less than the lower limit of the new national standard and the proportion exceeds 50% were vitamin D, iodine and choline. with the proportions(number of cases) of 98.33%(470 cases), 74.06%(354 cases) and 72.37%(275 cases), respectively. The maximum value of essential ingredients exceeded the maximum requirements stipulated in the new national standard, and the protein in 13.18%(63 cases) of the older infant formula milk powder was higher than the maximum requirements of the new national standard. CONCLUSION: The content of essential components in most commercial products in China meets the new national standard requirements. Some essential ingredients need to be adjusted.

[Distribution of vitamin K_2 content in Chinese traditional fermented soybean products].

OBJECTIVE: To determine the content of vitamin K_2 in different types of fermented bean products and analyze the difference of vitamin K_(2 )content. METHODS: A total of 98 kinds of typical fermented bean products were included in Chinese traditional fermented bean products(Douchi, Sufu, soybean paste). Process, region, sales volume, raw materials and flavor were considered, and the content of vitamin K_2 in fermented bean products was determined by high performance liquid chromatography. RESULTS: Chinese bean fermented foods generally contained vitamin K_2, and the subtype menaquinone-7(MK-7)was the main one. The content of vitamin K_2 in Douchi was the highest(437.55 µg/100 g), the content of vitamin K_2 in Sufu and Soybean paste were lower(7.48 µg/100 g and 2.47 µg/100 g). The content of vitamin K_2 in bacterial Douchi was higher than that in Mucor type and Aspergillus oryzae type which were 403.94, 232.98 and 81.00 µg/100 g(P<0.05). Soybean type Douchi was higher than that in black bean type of Douchi which were 610.41, 178.08 µg/100 g(P<0.05), and the content of vitamin K_2 in dry Douchi was higher than the content of vitamin K_2 in water Douchi which were 1 517.45 µg/100 g, 297.58 µg/100 g(P<0.05). However, there were no significant difference in the content of vitamin K_2 in Soybean paste and Sufu in different types and regions(P > 0.05). CONCLUSION: Vitamin K_2 is widely contained in Chinese fermented bean products, and its content is mainly affected by fermentation microorganisms and processing technology.

[Analysis of soybean phospholipids based on liquid chromatography-ion trap-time of flight-mass spectrometry].

OBJECTIVE: Using liquid chromatography-ion trap-time of flight-mass spectrometry to establish a soybean phospholipids(PL) analysis method, carry out comprehensive structural identification and quantitative analysis of soybean PL molecule species, and obtain soybean PL molecular composition and content data. METHODS: The PL profiles of 10 soybean varieties cultivated in northeast China were determined by a hydrophilic interaction liquid chromatography-ion trap-time of flight-mass spectrometry(HILIC-ESI-IT-TOF-MS) system. The hydrophilic interaction liquid chromatography realized class separation of PLs, and ion trap-time of flight-mass spectrometry realized the estimation of head group type, fatty acyl structure, and substituent position. The identified PL molecule species were quantified using accurate mass extraction and internal standard method. RESULTS: A total of 101 PL molecular species from 11 classes were estimated in soybean seeds, including 20 phosphatidylcholines(PC), 15 phosphatidylethanolamines(PE), 17 phosphatidylinositols(PI), 12 phosphatidylglycerols(PG), 9 phosphatidic acids(PA), 6 phosphatidylserines(PS), 5 lysophosphatidylcholines(LPC), 5 lysophosphatidylethanolamines(LPE), 6 lysophosphatidylinositols(LPI), 4 lysophosphatidylglycerols(LPG) and 2 lysophosphatidicacids(LPA). The limits of detection for the target object were ≤ 60 ng/mL and R~2 were all >0.99. The total concentration of PL ranged from 6873.1 to 12 678.6 µg/g in detected soybeans. Generally, most of the detected soybean cultivars were great resources of PL, especially SN-29, SN-61, HN-40 and DN-690. The concentrations of PC and PE in the tested soybean were higher, followed by PI, PG, PA and PS. Among the lysophospholipids, the concentration of LPC was the highest, followed by LPE, LPI, LPG and LPA. CONCLUSION: The soybean PL component analysis method established based on the HILIC-IT-TOF-MS system can achieve good separation of various types of PL, and can accurately characterize the head group type, fatty acyl structure and substituent position of PL molecule species. The molecular composition and content data of soybean PL were obtained.

[Determination of 21 polyphenols in fruits by high performance liquid chromatography].

OBJECTIVE: To establish a high performance liquid chromatography(HPLC) method for simultaneous determination of flavonoids(epicatechin, isoorientin, eriocitrin, hyperoside, narirutin, naringin, hesperidin, neohesperidin, quercetin, didymin, naringenin and hesperetin), phenolic acids(gallic acid, chlorogenic acid, caffeic acid, ferulic acid, sinapic acid and p-coumaric acid), terpenoids(limonin), stilbenes(piceatannol and resveratrol) in fruits. METHODS: Add ethanol-water(4∶1, V/V) solution to the fruit pulp sample, ultrasonic extraction at 55 ℃ for 10 min, after centrifugation, the supernatant was dried and re-dissolved, and then eluted with ZORBAX Eclipse XDB-C_(18)(4.6 mm×100 mm, 3.5 µm) as chromatographic column, polyphenols are determined by HPLC under switching wavelength, and quantified by external standard method. RESULTS: The 21 polyphenols can be detected within 45 min and well separated from baseline, with linear correlation coefficients greater than 0.999, the detection limit of the method was 0.03-0.31 µg/g, and the limit of quantitation of the method was 0.09-1.03 µg/g. The intra-day precision was 0.5%-9.3%, the inter-day precision was 2.0%-9.6%. The recoveries of more than 90% polyphenols in the three fruits at three levels were between 80.0% and 119.8%. The relative standard deviation of spiked recoveries of three samples was less than 10.8%. The detection result of citrus, mango, blueberry, persimmon and other samples proved that the composition of polyphenols in different fruits was different. CONCLUSION: The method is sensitive, accurate and reproducible, and is suitable for the determination of polyphenols in fruits.