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Abstract Background 2-Phenylethanol (2-PE) is one of the most widely used spices. Recently, 2-PE has also been considered a potential aviation fuel booster. However, the lack of scientific understanding of the 2-PE biosynthetic pathway and the cellular response to 2-PE cytotoxicity are the most important obstacles to the efficient biosynthesis of 2-PE. Results Here, metabolic engineering and tolerance engineering strategies were used to improve the production of 2-PE in Komagataella phaffii. First, the endogenous genes encoding the amino acid permease GAP1, aminotransferase AAT2, phenylpyruvate decarboxylase KDC2, and aldehyde dehydrogenase ALD4 involved in the Ehrlich pathway and the 2-PE stress response gene NIT1 in K. phaffii were screened and characterized via comparative transcriptome analysis. Subsequently, metabolic engineering was employed to gradually reconstruct the 2-PE biosynthetic pathway, and the engineered strain S43 was obtained, which produced 2.98 g/L 2-PE in shake flask. Furthermore, transcriptional profiling analyses were utilized to screen for novel potential tolerance elements. Our results demonstrated that cells with knockout of the PDR12 and C4R2I5 genes exhibited a significant increase in 2-PE tolerance. To confirm the practical applications of these results, deletion of the PDR12 and C4R2I5 genes in the hyper 2-PE producing strain S43 dramatically increased the production of 2-PE by 18.12%, and the production was 3.54 g/L. Conclusion This is the highest production of 2-PE produced by K. phaffii via l-phenylalanine conversion. These identified K. phaffii endogenous elements are highly conserved in other yeast species, suggesting that manipulation of these homologues might be a useful strategy for improving aromatic alcohol production. These results also enrich the understanding of aromatic compound biosynthetic pathways and 2-PE tolerance, and provide new elements and strategies for the synthesis of aromatic compounds by microbial cell factories.

Optimize the formula process of Dendrobium officinale granules using a multi index comprehensive scoring method combined with orthogonal experiments. Based on the registered Dendrobium officinale health food, the formula composition of raw materials in Dendrobium officinale health food was determined by using complex system entropy clustering algorithm. The diluent was filtered by the formation rate, dissolution rate and moisture absorption rate of granules. The ratio of raw materials and diluents, ethanol volume concentration, and ethanol dosage were taken as the inspection factors. The analytic hierarchy process (AHP) and entropy weight method (EWM) were combined to establish a multi-index comprehensive evaluation method (AHP-EWM method). The formulation process of granules was optimized through orthogonal experiments. The results showed that the formula combination was Dendrobium officinale, Lycium chinense Mill., and Paeoniae Radix Alba by the complex system entropy clustering algorithm. The AHP-EWM method determines the weights of each indicator as follows: Molding rate 0.3567, angle of rest 0.0847, melting rate 0.1778, and moisture absorption rate 0.3808. The optimal molding process was the raw material extract powder, dextrin, and microcrystalline cellulose (10:7:3, m/m), 50% ethanol volume concentration, and 5 mL ethanol dosage. The valieation test result showed that the AHP-EWM comprehensive score of the granules was 93.63±1.65, which was close to the theoretical prediction value. The optimized granules formulation process was stable and feasible. This study would provide a reference for the development of health products of Dendrobium officinale.

To explore the research hotspots and development trend of Dendrobium candidum based on CiteSpace knowledge map and patent analysis. Based on the Chinese and English literatures collected from CNKI and Web of Science, the knowledge map about keywords was constructed by using the visual analysis software CiteSpace 5.8.R3 to explore and analyze the reserach situation, the development trend and research hotspots of Dendrobium candidum. Combined with patent bibliometrics, the distribution and development trend of related patent fields of Dendrobium candidum were analyzed, and the food patents of Dendrobium candidum were investigated. The results showed that domestic research focused on Dendrobium candidum polysaccharides, health function, chemical constituents, product development and gene, while foreign research tends to clinical experiments, such as animal experiments and safety evaluation. There were many researches in the fields of active ingredient identification, pharmacological action and mechanism. Dendrobium officinale had a rich variety of foods, most of which were foods with clear health functions. A total of 9 health functions were involved, which was 42.04% to enhance immunity. Dendrobium candidum could be further studied in the field of food for different health functions, product preparation techniques, and flowers and leaves. This study would provide a reference for analyzing the research content of Dendrobium candidum, identifying research hotspots, and determining the direction of food patent applications.

Classical swine fever virus (CSFV) can dampen the host innate immunity by destabilizing IRF3 upon its binding with viral Npro. High mobility group box 1 (HMGB1), a non-histone nuclear protein, has diverse functions, including inflammation, innate immunity, etc., which are closely related to its cellular localization. We investigated potential mutual interactions between CSFV and HMGB1 and their effects on virus replication. We found that HMGB1 at the protein level, but not at mRNA level, was markedly reduced in CSFV-infected or Npro-expressing IPEC-J2 cells. HMGB1 in the nuclear compartment is anti-CSFV by promoting IFN-mediated innate immune response, as evidenced by overexpression of nuclear or cytoplasmic dominant HMGB1 mutant in IPEC-J2 cells stimulated with poly(I:C). However, CSFV Npro upregulates HMGB1 acetylation, a modification that promotes HMGB1 translocation into the cytoplasmic compartment where it is degraded by lysosomes. Ethyl pyruvate could downregulate HMGB1 acetylation and prevent Npro-mediated HMGB1 reduction. Inhibition of deacetylase HDAC1 with MS275 or by RNA silencing could promote Npro-mediated HMGB1 degradation. Taken together, our study elucidates the mechanism with which HMGB1 in the nuclei initiates antiviral innate immune response to suppress CSFV replication and elaborates the pathway by which CSFV uses its Npro to evade from HMGB1-mediated antiviral immunity through upregulating HMGB1 acetylation with subsequent translocation into cytoplasm for lysosomal degradation.

At present, the concrete-filled steel tube structure has been widely used in various practical projects. Due to the low tensile strength of the core concrete of round steel tube concrete (CFST) specimens, the axial tensile performance of CFST specimens is far from superior to its compressive performance. However, in practical projects, the concrete-filled steel tube members bearing tensile load often appear. In order to study the axial tensile properties of CFST specimens, the axial tensile tests of 5 CFST specimens and 1 pure steel tube specimen were carried out with steel tube diameter and concrete strength as variation parameters. The results show that the bearing capacity of CFST specimens is increased by 7.5%–16.3% compared with that of pure steel tube specimens with the same cross-sectional area, mainly because the core concrete limits the circumferential shrinkage of the outer steel tube. The larger the cross-sectional area of CFST specimens is, the higher the bearing capacity is. In this paper, the stress-strain relationship and the overall failure mode of CFST members under tensile force are studied, and the deformation characteristics and stress of steel pipe and core concrete are analyzed, which is expected to provide a reference for the application of CFST specimens in practical engineering.

Excessive fluoride exposure and epigenetic change can induce numerous adverse health outcomes, but the role of epigenetics underneath the harmful health effects induced by fluoride exposure is unclear. In such gap, we evaluated the associations between fluoride exposure and genome-wide DNA methylation, and identified that novel candidate genes associated with fluoride exposure. A total of 931 school-age children (8–12 years) in Tongxu County of Henan Province (China) were recruited in 2017. Urinary fluoride (UF) concentrations were measured using the national standardized ion selective electrode method. Participants were divided into a high fluoride-exposure group (HFG) and control group (CG) according to the UF concentrations. Candidate differentially methylated regions (DMRs) were screened by Infinium-Methylation EPIC BeadChip of DNA samples collected from 16 participants (eight each from each group). Differentially methylated genes (DMGs) containing DMRs associated with skeletal and neuronal development influenced by fluoride exposure were confirmed using MethylTarget™ technology from 100 participants (fifty each from each group). DMGs were verified by quantitative methylation specific PCR from 815 participants. Serum levels of hormones were measured by auto biochemical analyzer. The mediation analysis of methylation in the effect of fluoride exposure on hormone levels was also performed. A total of 237 differentially methylated sites (DMSs) and 212 DMRs were found in different fluoride-exposure groups in the epigenome-wide phase. Methylation of the target sequences of neuronatin (NNAT), calcitonin-related polypeptide alpha (CALCA) and methylenetetrahydrofolate dehydrogenase 1 showed significant difference between the HFG and CG. Each 0.06% (95% CI: −0.11%, −0.01%) decreased in NNAT methylation status correlated with each increase of 1.0 mg/L in UF concentration in 815 school-age children using QMSP. Also, each 1.88% (95% CI: 0.04%, 3.72%) increase in CALCA methylation status correlated with each increase of 1.0 mg/L in UF concentration. The mediating effect of NNAT methylation was found in alterations of ACTH levels influenced by fluoride exposure, with a β value of 11.7% (95% CI: 3.4%, 33.4%). In conclusion, long-term fluoride exposure affected the methylation pattern of genomic DNA. NNAT and CALCA as DMGs might be susceptible to fluoride exposure in school-age children.

Objective: This study is aimed to explore the potential association among the estrogen receptor alpha (ESRα) promoter methylation, lipid metabolism and the risk of type 2 diabetes mellitus (T2DM).Methods: A total of 1143 rural residents were recruited randomly from Henan Province, China. The circulating methylation levels in ESRα promoter region were determined by quantitative methylation-specific polymerase chain reaction. Serum high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglyceride (TG), total cholesterol (TC) and fasting plasma-glucose (FPG) were measured.Results: The ESRα promoter methylation levels were negatively associated with HDL-C levels whether gender stratification was performed (P < 0.05) and positively correlated with LDL-C in men (P < 0.05). Each unit standard deviation (SD) increment in TG was associated with a 43% increase (95% CI: 1.25, 1.64) in the risks of T2DM in all participants, a 36% increase (95% CI: 1.13, 1.64) in the risks of T2DM in men and a 49% increase (95% CI: 1.21, 1.83) in the risks of T2DM in women. Furthermore, each SD increment in HDL-C was associated with a reduction of 25% (OR = 0.75, 95% CI: 0.58, 0.97) in the risks of T2DM in men, and the risk of T2DM in men may be more susceptible to HDL-C than that in women (P for interaction < 0.05). Additionally, we found that the risk of T2DM in participants with lower methylation levels (≤4.07%) were more susceptible to HDL-C (P for interaction < 0.05).Conclusions: These findings suggested that lipid metabolism was associated with ESRα promoter methylation levels and the risk of T2DM. Besides, the levels of ESRα promoter methylation and gender can modify the association of HDL-C and T2DM.

Mitochondrial dynamics is essential for the maintenance of cell homeostasis. Previous studies have shown that porcine circovirus 2 (PCV2) infection decreases the mitochondrial membrane potential and causes the elevation of reactive oxygen species (ROS), which may ultimately lead to mitochondrial apoptosis. However, whether PCV2 induce mitophagy remains unknown. Here we show that PCV2-induced mitophagy in PK-15 cells via Drp1 phosphorylation and PINK1/Parkin activation. PCV2 infection enhanced the phosphorylation of Drp1 and its subsequent translocation to mitochondria. PCV2-induced Drp1 phosphorylation could be suppressed by specific CDK1 inhibitor RO-3306, suggesting CDK1 as its possible upstream molecule. PCV2 infection increased the amount of ROS, up-regulated PINK1 expression, and stimulated recruitment of Parkin to mitochondria. N-acetyl-L-cysteine (NAC) markedly decreased PCV2-induced ROS, down-regulated Drp1 phosphorylation, and lessened PINK1 expression and mitochondrial accumulation of Parkin. Inhibition of Drp1 by mitochondrial division inhibitor-1 Mdivi-1 or RNA silencing not only resulted in the reduction of ROS and PINK1, improved mitochondrial mass and mitochondrial membrane potential, and decreased mitochondrial translocation of Parkin, but also led to reduced apoptotic responses. Together, our study shows that ROS induction due to PCV2 infection is responsible for the activation of Drp1 and the subsequent mitophagic and mitochondrial apoptotic responses.

Accurate tree height and diameter at breast height (dbh) are important input variables for growth and yield models. A total of 5503 Chinese Metasequoia trees were used in this study. We studied 53 fitted models, of which 7 were linear models and 46 were non-linear models. These models were divided into two groups of single models and multivariate models according to the number of independent variables. The results show that the allometry equation of tree height which has diameter at breast height as independent variable can better reflect the change of tree height; in addition the prediction accuracy of the multivariate composite models is higher than that of the single variable models. Although tree age is not the most important variable in the study of the relationship between tree height and dbh, the consideration of tree age when choosing models and parameters in model selection can make the prediction of tree height more accurate. The amount of data is also an important parameter what can improve the reliability of models. Other variables such as tree height, main dbh and altitude, etc can also affect models. In this study, the method of developing the recommended models for predicting the tree height of native Metasequoias aged 50-485 years is statistically reliable and can be used for reference in predicting the growth and production of mature native Metasequoia.

We developed and tested a prototype of an antibody microarray immunoassay for simultaneous quantitative detection of four typical mycotoxins (aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1) in corn samples. The test kit consisted of a nitrocellulose membrane layered with immobilized monoclonal antibodies against mycotoxins. During the assay, the mycotoxin-protein conjugates were biotinylated. The signal detection was enhanced by a combination of the biotin-streptavidin system and enhanced chemiluminescence (ECL). This improved the sensitivity of the assay. Under the optimized conditions, four calibration curves with goodness of fit (R2 > 0.98) were plotted. The results showed that the detection limits for aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1 were 0.21, 0.19, 0.09, and 0.24 ng/mL, with detection ranges of 0.47–55.69, 0.48–127.11, 0.22–31.36, and 0.56–92.57 ng/mL, respectively. The limit of detection (LOD) of this antibody microarray for aflatoxin B1, ochratoxin A, zearalenone, and fumonisin B1 in corn was 5.25, 4.75, 2.25, and 6 μg/kg, respectively. The recovery rates from the spiked samples were between 79.2% and 113.4%, with coefficient of variation

A rapid and sensitive electrochemical biosensor based on magnetic nanoparticles and screen-printed electrodes (MNPs-SPEs sensor) was developed for the detection of ochratoxin A (OTA) in cereal and feed samples. Different types of magnetic nanoparticles-based ELISA (MNPs-ELISA) were optimized, and the signal detection, as well as sensitivity, was enhanced by the combined use of screen-printed electrodes (SPEs). Under the optimized conditions, the calibration curve of the MNPs-SPEs sensor was y = 0.3372x + 0.8324 (R2 = 0.9805). The linear range of detection and the detection limit were 0.01–0.82 ng/mL and 0.007 ng/mL, respectively. In addition, 50% inhibition (IC50) was detectable at 0.10 ng/mL. The limit of detection (LOD) of this MNPs-SPEs sensor in cereal and feed samples was 0.28 μg/kg. The recovery rates in spiked samples were between 78.7% and 113.5%, and the relative standard deviations (RSDs) were 3.6–9.8%, with the coefficient of variation lower than 15%. Parallel analysis of commercial samples (corn, wheat, and feedstuff) showed a good correlation between MNPs-SPEs sensor and liquid chromatography tandem mass spectrometry (LC/MS-MS). This new method provides a rapid, highly sensitive, and less time-consuming method to determine levels of ochratoxin A in cereal and feedstuff samples.

BACKGROUND: Shotgun proteomics data analysis usually relies on database search. Because commonly employed protein sequence databases of most species do not contain sufficient protein information, the application of shotgun proteomics to the research of protein sequence profile remains a big challenge, especially to the species whose genome has not been sequenced yet. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we present a workflow with integrated database to partly address this problem. First, we downloaded the homologous species database. Next, we identified the transcriptome of the sample, created a protein sequence database based on the transcriptome data, and integtrated it with homologous species database. Lastly, we developed a workflow for identifying peptides simultaneously from shotgun proteomics data. CONCLUSIONS/SIGNIFICANCE: We used datasets from orange leaves samples to demonstrate our workflow. The results showed that the integrated database had great advantage on orange shotgun proteomics data analysis compared to the homologous species database, an 18.5% increase in number of proteins identification.

N-(2-hydroxyethyl)ethylenediaminium iodides (HEEDAIs) and N-(2-hydroxyethyl)piperazinium iodides (HEPIs) were synthesized, and their thermal properties were analysed. The influence of HEEDAI and HEPI on I3-/I- redox behavior in binary ionic liquid was investigated. The result revealed that HEEDAI can suppress the recombination between I3- and the injected electrons in TiO2 conduction band and be used as the alternative of 4-tert-butylpyridine in the electrolyte of dye-sensitized solar cells. The electrolyte C, 0.15 mol⋅L−1 I2, HEEDAI and MPII with mass ratio of 1 : 4, gave the short-circuit photocurrent density of 9.36 mA⋅cm−2, open-circuit photovoltage of 0.67 V, fill factor of 0.52, and the corresponding photoelectric conversion efficiency of 3.24% at the illumination (air mass 1.5, 100 mW⋅cm−2, active area 0.25 cm2).