15 research outputs found
The impact of giant jellyfish Nemopilema nomurai blooms on plankton communities in a temperate marginal sea
Abstract(#br)This study focused on the bloom-developing process of the giant jellyfish, Nemopilema nomurai , on phytoplankton and microzooplankton communities. Two repeated field observations on the jellyfish bloom were conducted in June 2012 and 2014 in the southern Yellow Sea where blooms of N . nomurai were frequently observed. We demonstrated that the bloom was made up of two stages, namely the developing stage and the mature stage. Total chlorophyll a increased and the concentrations of inorganic nutrients decreased during the developing stage, while both concentrations maintained stable and at low levels during the mature stage. Our analysis revealed that phosphate excreted by growing N . nomurai promoted the growth of phytoplankton at the developing stage. At the mature stage, size compositions of microzooplankton were altered and tended to be smaller via a top-down process, while phytoplankton compositions, affected mainly through a bottom-up process, shifted to be less diatoms and cryptophytes but more dinoflagellates
Hygrothermal ageing characterisation of epoxy resin based on transmission characteristics of microwave resonator with interdigitalâcapacitorâshaped defected ground structure
Abstract In this article, a method is proposed for the characterisation of epoxy resin thermal and hygrothermal ageing based on microwave resonator with interdigitalâcapacitorâshaped defected ground structure (IDCSâDGS), which can realise rapid and simple nonâdestructive testing of the ageing degree of epoxy resin materials. The resonant frequency of IDCSâDGS was proved to decrease with the increase of dielectric constant of the around material by means of simulation. The breakdown test at high voltage showed the deterioration of epoxy resin after hygrothermal ageing, which is caused by moisture absorption and hydrolysis process. In addition, thermal ageing also caused a decline in the insulation performance of epoxy resin samples. Accelerated oxidation of epoxy resin samples at high temperatures produces polar molecules that increase the dielectric constant of the samples. As for the hygrothermal ageing samples, the entrance of polar water molecules will increase the dielectric constant of epoxy resin, and thus make an effect on the resonant frequency of IDCSâDGS. The tests of transmission performance show that after the hygrothermally aged epoxy resin samples were put on the microwave sensor, the resonant frequency decreased continuously with hygrothermal ageing time, and the deviations of resonant frequency are highly consistent with the weight variation rate of the samples
Table1_Elucidating the role of TWIST1 in ulcerative colitis: a comprehensive bioinformatics and machine learning approach.docx
Background: Ulcerative colitis (UC) is a common and progressive inflammatory bowel disease primarily affecting the colon and rectum. Prolonged inflammation can lead to colitis-associated colorectal cancer (CAC). While the exact cause of UC remains unknown, this study aims to investigate the role of the TWIST1 gene in UC.Methods: Second-generation sequencing data from adult UC patients were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified, and characteristic genes were selected using machine learning and Lasso regression. The Receiver Operating Characteristic (ROC) curve assessed TWIST1âs potential as a diagnostic factor (AUC score). Enriched pathways were analyzed, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Variation Analysis (GSVA). Functional mechanisms of marker genes were predicted, considering immune cell infiltration and the competing endogenous RNA (ceRNA) network.Results: We found 530 DEGs, with 341 upregulated and 189 downregulated genes. TWIST1 emerged as one of four potential UC biomarkers via machine learning. TWIST1 expression significantly differed in two datasets, GSE193677 and GSE83687, suggesting its diagnostic potential (AUC = 0.717 in GSE193677, AUC = 0.897 in GSE83687). Enrichment analysis indicated DEGs associated with TWIST1 were involved in processes like leukocyte migration, humoral immune response, and cell chemotaxis. Immune cell infiltration analysis revealed higher rates of M0 macrophages and resting NK cells in the high TWIST1 expression group, while TWIST1 expression correlated positively with M2 macrophages and resting NK cell infiltration. We constructed a ceRNA regulatory network involving 1 mRNA, 7 miRNAs, and 32 long non-coding RNAs (lncRNAs) to explore TWIST1âs regulatory mechanism.Conclusion: TWIST1 plays a significant role in UC and has potential as a diagnostic marker. This study sheds light on UCâs molecular mechanisms and underscores TWIST1âs importance in its progression. Further research is needed to validate these findings in diverse populations and investigate TWIST1 as a therapeutic target in UC.</p
Effects of dietary fibers or probiotics on functional constipation symptoms and roles of gut microbiota: a double-blinded randomized placebo trial
ABSTRACTDietary fibers/probiotics may relieve constipation via optimizing gut microbiome, yet with limited trial-based evidences. We aimed to evaluate the effects of formulas with dietary fibers or probiotics on functional constipation symptoms, and to identify modulations of gut microbiota of relevance. We conducted a 4-week double-blinded randomized placebo-controlled trial in 250 adults with functional constipation. Intervention: A: polydextrose; B: psyllium husk; C: wheat branâ+âpsyllium husk; D: Bifidobacterium animalis subsp. lactis HN019â+âLacticaseibacillus rhamnosus HN001; Placebo: maltodextrin. Oligosaccharides were also included in group A to D. 16S rRNA sequencing was used to assess the gut microbiota at weeks 0, 2, and 4. A total of 242 participants completed the study. No time-by-group effect was observed for bowel movement frequency (BMF), Bristol stool scale score (BSS), and degree of defecation straining (DDS), while BSS showed mean increases of 0.95â1.05 in group A to D (all Pâ<â0.05), but not significantly changed in placebo (Pâ=â0.170), and 4-week change of BSS showed similarly superior effects of the interventions as compared placebo. Group D showed a marginal reduction in plasma 5-hydroxytryptamine. Group A resulted in a higher Bifidobacterium abundance than placebo at week 2 and 4. Fourteen genera showed intervention-specific increasing or decreasing trends continuously, among which Anaerostipes showed increasing trends in groups B and C, associated with BMF increase. Random forest models identified specific baseline microbial genera panels predicting intervention responders. In conclusion, we found that the dietary fibers or probiotics may relieve hard stool, with intervention-specific changes in gut microbiota relevant to constipation relief. Baseline gut microbiota may predispose the intervention responsiveness. ClincialTrials.gov number, NCT04667884