Predicting the storage time of green tea by myricetin based on surface-enhanced Raman spectroscopy.

The quality of green tea changes rapidly due to the oxidation and degradation of polyphenols during storage. Herein, a simple and fast Surface-enhanced Raman spectroscopy (SERS) strategy was established to predict changes in green tea during storage. Raman spectra of green tea with different storage times (2020-2015) were acquired by SERS with silver nanoparticles. The PCA-SVM model was established based on SERS to quickly predict the storage time of green tea, and the accuracy of the prediction set was 97.22%. The Raman peak at 730 cm-1 caused by myricetin was identified as a characteristic peak, which increased with prolonged storage time and exhibited a linear positive correlation with myricetin concentration. Therefore, SERS provides a convenient method for identifying the concentration of myricetin in green tea, and myricetin can function as an indicator to predict the storage time of green tea.

Anti-inflammatory effects of progesterone through NF-κB and MAPK pathway in lipopolysaccharide- or Escherichia coli-stimulated bovine endometrial stromal cells.

Postpartum uterine infection in dairy cows is commonly caused by pathogenic bacteria such as Escherichia coli (E. coli). Progesterone elicits immunosuppressive function within bovine endometrium, and has been suggested to be related to postpartum uterine infection. Endometrial stroma is exposed to bacteria due to the disruption of epithelium during parturition, but the effect and mechanism of progesterone on innate immune response of stromal cells has not been reported. This study evaluated the impact of progesterone on inflammatory response of primary endometrial stromal cells stimulated by lipopolysaccharide or heat-killed E. coli. Quantitative PCR analysis revealed that progesterone repressed mRNA induction of IL1B, IL6, TNF, CXCL8, NOS2, and PTGS2 in stromal cells in response to lipopolysaccharide or E. coli challenge. Consistently, Western blot and immunofluorescence staining results showed that progesterone suppressed lipopolysaccharide- or E. coli-induced MAPK and NF-κB activations characterized with decreased phosphorylations of ERK1/2, JNK, P38, IκBα, and P65, and inhibition of P65 nuclear translocation. In unstimulated stromal cells, progesterone alone did not affect the mRNA transcription for IL6, TNF, CXCL8, NOS2, and PTGS2, and the signaling cascade of MAPK and NF-κB, but decreased IL1B mRNA expression. These results revealed that the anti-inflammatory effect of progesterone in lipopolysaccharide- or E. coli-challenged endometrial stromal cells was probably mediated through MAPK and NF-κB pathways.

Comparative Analysis and Identification of Differentially Expressed microRNAs in the Hypothalamus of Kazakh Sheep Exposed to Different Photoperiod Conditions.

MicroRNAs (miRNA) plays an important role in several mammalian biological regulatory processes by post-transcriptionally regulating gene expression. However, there is little information on the miRNAs involved in the photoperiodism pathway that controls seasonal activity. To enhance our knowledge on the effect of different photoperiod conditions on miRNA, we divided Kazakh sheep into two groups: one exposed to a long photoperiod (LP, 16L:8D) and another with exposed to a short photoperiod (SP, 8L:16D) under supplemental feeding conditions. Further we compared the related miRNAs and target genes between the two groups. Fifteen differentially expressed miRNAs were identified, which were associated with 310 regulatory pathways covering photoperiodism, reproductive hormones, and nutrition. The miR-136-GNAQ pair was selected and validated as a differentially expressed, and a dual-luciferase reporter assay showed that the negative feedback loop existed between them. Examination of the expression profile revealed that the GNAQ expression was low in the estrous females both under LP and SP conditions, but high expression of GNAQ was observed in the anestrous females under LP conditions. Moreover, functional analysis revealed that KISS1 and GnRH expression was upregulated when GNAQ expression was downregulated in the hypothalamic cells, whereas DIO2 and TSHB expression was downregulated. Thus, miR-136-GNAQ might act as a switch in the regulation of seasonal estrus under different photoperiod conditions. These findings further enrich our understanding of the relationship between miRNAs and seasonal regulation of reproductive activity. Furthermore, our study provides novel insights into the miRNA-mediated regulatory mechanisms for overcoming photoinhibition in the seasonally breeding mammals, such as Kazakh sheep.

Identification and validation of key miRNAs and miRNA-mRNA regulatory network associated with uterine involution in postpartum Kazakh sheep.

MicroRNAs (miRNAs) are widely expressed in different mammalian tissues and exert their biological effects through corresponding target genes. miRNA target genes can be rapidly and efficiently identified and screened by combining bioinformatics prediction and experimental validation. To investigate the possible molecular regulatory mechanisms involving miRNAs during uterine involution in postpartum ewes, we used Illumina HiSeq sequencing technology to screen for the number and characteristics of miRNAs in faster uterine involution and normal uterine involution group. A total of 118 differentially expressed miRNAs, including 33 known miRNAs and 85 new miRNAs, were identified in the hypothalamic library, whereas 54 miRNAs, including 5 known miRNAs and 49 new miRNAs, were identified in the uterine library. Screening with four types of gene prediction software revealed 73 target genes associated with uterine involution, and subsequently, GO annotation and KEGG pathway analysis were performed. The results showed that, in the hypothalamic-uterine axis, uterine involution in postpartum ewes might primarily involve two miRNA-target gene pairs, namely, miRNA-200a-PTEN and miRNA-133-FGFR1, which can participate in GnRH signal transduction in the upstream hypothalamus and in the remodeling process at the downstream uterus, through the PI3K-AKT signaling pathway to influence the recovery of the morphology and functions of the uterus during the postpartum period in sheep. Therefore, identification of differentially expressed miRNAs in this study fills a gap in the research related to miRNAs in uterine involution in postpartum ewes and provides an important reference point for a comprehensive understanding of the molecular mechanisms underlying the regulation of postpartum uterine involution in female livestock.

Comparative analysis of differentially expressed miRNAs related to uterine involution in the ovine ovary and uterus.

To examine the possible miRNA molecular regulatory mechanisms during maternal uterine involution after delivery, we selected ovary and uterus tissues that are structurally connected as experimental materials. We employed Illumina HiSeq sequencing to screen and analyze the quantity and characteristics of miRNA in postpartum ewes in the methylergometrine-treated group and physiological saline control group. Results showed that 16 miRNAs were identified in the ovary libraries, including 4 known miRNAs and 12 novel miRNAs. In the uterus libraries, 54 miRNAs were identified, which included 5 known miRNAs and 49 novel miRNAs. At the same time, target gene prediction, GO annotation, and KEGG signaling pathway enrichment analysis were employed. We found that maternal uterine involution after delivery may involve two miRNA-target gene pairs, i.e., miRNA-200a-ZEB1 and YAP1. The YAP1/Hippo signaling pathway is used to construct an ovary-uterine axial regulatory mechanism to regulate the restoration of postpartum maternal uterine morphology and function. In view of this, the identification of miRNAs with significant differences in this study fills a gap in research on miRNAs associated with regulation of postpartum uterine recovery in ewes and provided an important reference for comprehensive understanding and in-depth research on the regulatory molecular network mechanism for postpartum uterine involution in small ruminants.

A Survey on HIV/AIDS-Related Knowledge, Attitudes, Risk Behaviors, and Characteristics of Men Who Have Sex with Men among University Students in Guangxi, China.

In recent years, the prevalence of human immunodeficiency virus (HIV) infection among Chinese university students has increased significantly, and HIV transmission among men who have sex with men (MSM) comprises more than half of the new cases. There is still a lack of research investigating the incidence of male-to-male sex, the attitudes towards MSM, and the awareness of HIV/AIDS among university students in Guangxi, one of the HIV high-risk areas in China. Therefore, we performed a cross-sectional investigation among 578 male students, recruited by stratified sampling, in universities in Nanning, Guangxi, between January 2016 and March 2017. Researcher-administered anonymous questionnaires were completed. Self-recognition as MSM was found in 8.48% of the subjects. Compared with non-MSM, university student MSM included more people over the age of 20 (OR = 4.95), had less migration from other districts of Guangxi (OR = 0.26), and the majority were nonmedical students (OR = 8.99). In total, 63.25% of the male student participants reported a lack of acceptance of MSM, while 35.47% acknowledged barriers between themselves and acquaintances who were MSM. Overall, 67.30% of the subjects correctly answered questions related to AIDS knowledge. The proportion of MSM subjects who answered the AIDS-related questions completely correctly was significantly lower than that of non-MSM subjects (42.86% vs. 69. 57%, respectively, OR: 0.33), but the self-recognition risk of MSM was significantly higher than that of non-MSM (OR = 2.59). Risky behaviors associated with HIV infections, including smoking, alcohol consumption, drug abuse, and inconsistent condom use, were significantly higher among the MSM participants. The percentages of student's willingness to accept MC and PrEP were 70.93% and 77.51%, respectively. These results raise the alarm that university student MSM in Guangxi, China, require urgent public attention and more effective health education, including the education on MC and PrEP.