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Red ginseng is a steamed and dried processing product of the cultivating root and rhizome of Panax ginseng C. A. Mey., which is one of the most widely used in ginseng products. The main active ingredient of red ginseng is ginsenoside, which is different from the content of ginseng caused by thermal process, such as chemical transformation by hydrolysis reaction and hydrated reaction. In recent years, the treatment of type 2 diabetes mellitus (T2DM) by red ginseng has attracted extensive attention. Ginsenoside has the effect of treating T2DM, but it is not easy to be absorbed directly by oral administration, and the bioavailability is low. Therefore, the metabolism of ginsenoside of red ginseng was studied in this research. The influence of intestinal flora on diseases has been paid more and more attention. Studies have shown that drug molecules can interact with intestinal microorganisms to produce metabolites of intestinal flora and active components of traditional Chinese medicine transformed by intestinal flora, which may be a new way to reveal the potential mechanism of action of red ginseng. Therefore, it is necessary to identify and elucidate ginsenosides in feces. A method of ultra performance liquid chromatography mass spectrometry (UPLC-MS) was established for qualitative and quantitative analysis of ginsenosides in red ginseng, and the content changes of ginsenosides in feces and serum of rats after intragastric administration of total ginsenosides were analyzed. Thermo Syncronis C18 column (100 mm×2.1 mm×1.7 μm) was used, mobile phase A was 0.1% formic acid in water, mobile phase B was acetonitrile, and flow rate was 0.2 mL/min, injection volume was 5 μL, UPLC was equipped with binary linear gradient pump, mass spectrometry was adopted electrospray negative ion mode. Ginsenosides were identified by the information of the retention times, molecular mass, and specific MS/MS fragments. The developed UPLC-MS method for quantitative analysis of ginsenosides was validated with respect to linearity, precision, repeatability, stability, and recovery. The result showed that the detection method of ginsenoside is speedy and accurate. Ginsenosides NotoR1, Rg1, Re, Rf, Rg2, Rh1, Rb1, Rc, Ro, Rb2, Rb3, Rd, Rg3, Rk1 in feces and serum of rats are detected, which show that the intestinal flora did not completely transform ginsenoside, and a part of ginsenosides are absorbed into the blood as prototype components playing a role in the treatment of T2DM. The changes of metabolites of ginsenoside in feces were studied with the prolongation of intervention time, which provided a certain basis for the pharmacodynamics of ginsenosides in red ginseng.

Moutai is a world-famous traditional Chinese liquor with complex taste and aroma, which are considered to be strongly influenced by the quality of fermentation starters (Daqu). However, the role of microbial communities in the starters has not been fully understood. In this study, we revealed the microbial composition of 185 Moutai starter samples, covering three different types of starters across immature and mature phases, and functional gene composition of mature starter microbiome. Our results showed that microbial composition patterns of immature starters varied, but they eventually were similar and steady when they became mature starters, after half-year storage and subsequent mixing. To help identify two types of immature starters, we selected seven operational taxonomic unit (OTU) markers by leave-one-out cross validation (LOOCV) and an OTU classified as Saccharopolyspora was the most decisive one. For mature starters, we identified a total of 16 core OTUs, one of which annotated as Bacillus was found positively associated with saccharifying power. We also identified the functional gene and microbial composition in starch and cellulose hydrolysis pathways. Microbes with higher abundances of alpha-glucosidase, alpha-amylase, and glucoamylase probably contributed to high saccharifying power. Overall, this study reveals the features of Moutai starter microbial communities in different phases and improves understanding of the relationships between microbiota and functional properties of the starters. [ABSTRACT FROM AUTHOR]

A dual-heterojunction-trench (DHT) diode is proposed as having an improved electrical performance compared with dual-metal-trench (DMT) diodes. This paper is based on simulations performed using the Silvaco TCAD tool. The DHT diode not only improves the compromise between forward current and breakdown voltage but also has a better I–V characteristic compared with DMT diodes. The P-polysilicon region concentration was found to have only a minor effect but the mesa width, P+ polysilicon region concentration and drift region concentration have a great influence on the I–V characteristics of the proposed device. The effect of the interface charge and the forward and reverse characteristics of the proposed device at room and high temperatures were also simulated. [ABSTRACT FROM PUBLISHER]

Weighted gene co-expression network analysis (WGCNA) is a method for analysing gene expression patterns across multiple samples, clustering genes with similar expression patterns and identifying key genes associated with specific traits or phenotypes. In this study, we investigated the effects of fucoxanthin accumulation in Phaeodactylum tricornutum in response to abiotic stresses of phosphorus deficiency, red light, and yellow light using transcriptome sequencing and weighted gene co-expression network analysis. The results showed that compared to the control, the fucoxanthin content of P. tricornutum was significantly increased after phosphorus deficiency and red light treatment ( P <0.05), but significantly decreased after yellow light treatment ( P <0.05). A weighted gene co-expression network was constructed using 10,392 genes obtained from transcriptome sequencing, and β=18 (R 2 >0.8) was chosen as a soft threshold in order to ensure a scale-free network. A total of 10 co-expression modules were identified by correlation analysis of fucoxanthin content, with the purple module positively correlated with fucoxanthin content ( r =0.9, P =1E-200), and 9 key genes were identified, including five genes in the fucoxanthin biosynthesis pathway ( DXR , PSY , PDS1 , ZEP2 , VDL2 ) and 4 transcription factors ( bHLH5 , HOX2 , CCHH13 , HSF1b ). Further qRT-PCR confirmed that key genes were more highly expressed in the phosphorus deficiency treatment and linear regression analysis showed that the relative gene expressions were all highly correlated with the transcriptome data. The results of this study provide a basis for further investigation of the complex regulatory mechanisms of fucoxanthin in P. tricornutum.

β-carotenoid hydroxylase (CHYB) is an important rate-limiting enzyme in the biosynthesis of plant carotenoid. In this study, chyb1 and chyb2, two gene families in Dunaliella viridis were obtained by RNA-seq. The fragment of promoters of CHYB family genes, 1 080 bp for chyb1 (GenBank No. KY012338) and 1 155 bp for chyb2 (GenBank No. KY012339) were cloned by the Genome Walking Technology, respectively. Cis-acting elements of two promoters were analyzed by Plantcare soft. The results show that the chyb1 gene promoter contains more cis-acting elements in responses to abiotic stresses, such as methyl jasmonate, arachidonic acid, acetylsalicylic acid, and so on. On the other hand, the chyb2 promoter contains more cis-acting elements in response to light stress. qRT-PCR results show that the mRNA expression levels of CHYBs are modulated by their promoters, and different CHYB gene families response to distinct stresses.