Temporal and Spatial Analysis of Negative Emotions in China during the COVID-19 Pandemic.

This research aims to explore the spatiotemporal distribution patterns of negative emotions in mainland China during different stages of the COVID-19 pandemic and the external factors influencing this clustering. Using Baidu Index data for 91 negative emotion keywords, a retrospective geographic analysis was conducted across Chinese provinces from 14 October 2019 to 7 July 2022. Four spatial analysis methods (Global Moran's Index, Local Moran's Index, Bivariate Global Moran's Index, and Bivariate Local Moran's Index) are employed to identify potential clustering patterns and influencing factors of negative emotions at different stages. The results indicate that the COVID-19 pandemic significantly intensified the clustering effect of negative emotions in China, particularly with a more pronounced radiation effect in northwestern provinces. Spatial positive correlations are observed between pandemic-related Baidu indices (pandemic Baidu index, government Baidu index, nucleic acid Baidu index) and negative emotions. These findings contribute to understanding the spatiotemporal distribution characteristics of negative emotions in China post the COVID-19 outbreak and can guide the allocation of psychological resources during emergencies, thereby promoting social stability.

Engineering the thermostability of d-lyxose isomerase from Caldanaerobius polysaccharolyticus via multiple computer-aided rational design for efficient synthesis of d-mannose.

d-Mannose is an attractive functional sugar that exhibits many physiological benefits on human health. The demand for low-calorie sugars and sweeteners in foods are increasingly available on the market. Some sugar isomerases, such as d-lyxose isomerase (d-LIase), can achieve an isomerization reaction between d-mannose and d-fructose. However, the weak thermostability of d-LIase limits its efficient conversion from d-fructose to d-mannose. Nonetheless, few studies are available that have investigated the molecular modification of d-LIase to improve its thermal stability. In this study, computer-aided tools including FireProt, PROSS, and Consensus Finder were employed to jointly design d-LIase mutants with improved thermostability for the first time. Finally, the obtained five-point mutant M5 (N21G/E78P/V58Y/C119Y/K170P) showed high thermal stability and catalytic activity. The half-life of M5 at 65 °C was 10.22 fold, and the catalytic efficiency towards 600 g/L of d-fructose was 2.6 times to that of the wild type enzyme, respectively. Molecular dynamics simulation and intramolecular forces analysis revealed a thermostability mechanism of highly rigidity conformation, newly formed hydrogen bonds and π-cation interaction between and within protein domains, and redistributed surface electrostatic charges for the mutant M5. This research provided a promising d-LIase mutant for the industrial production of d-mannose from d-fructose.

TLR8 agonist partially improves IFN-γ deficiency of NK cells in chronic hepatitis B through the synergy of monocytes.

BACKGROUND: Natural killer (NK) cells exhibit a selective deficiency of IFN-γ production in chronic hepatitis B (CHB). Toll-like receptor 8 (TLR8) agonists could induce IFN-γ production in immune cells, although their effects on the deficiency in NK cells remain unclear. AIMS: To investigate TLR8 expression in NK cells and the effect of TLR8 agonists in patients with CHB METHODS: We enrolled 32 patients with CHB and 19 healthy controls to assess TLR8 expression and IFN-γ production in NK cells. The sorted NK cells and monocytes were co-cultured to compare the extent of IFN-γ and IL-10 production after TLR8 agonist ssRNA40 stimulation. The synergic effect of NK cells and monocytes was assessed by blocking IL-12 and IL-18. We recruited another 22 patients with CHB undergoing nucleotide analogue (NA) therapy to explore the impact of antiviral treatment on the ssRNA40-mediated response of NK cells. RESULTS: In patients with CHB, TLR8 expression in NK cells was up-regulated, accompanied by insufficient IFN-γ production. The enhanced IFN-γ secretion by ssRNA40 in NK cells depended on monocyte-derived IL-12 and IL-18. NK cells displayed an imbalanced response to ssRNA40 in patients with CHB with a weak increase in IFN-γ despite a higher IL-10 production. The response was improved in patients with CHB undergoing NA therapy. CONCLUSIONS: In patients with CHB, targeting TLR8 partially rescues the IFN-γ insufficiency in NK cells. However, NK cells show an inhibitory response to TLR8 agonist stimulation. TLR8 agonist combined with NA may enhance the antiviral effect of NK cells.

Integrated Analyses of the Gut Microbiota, Intestinal Permeability, and Serum Metabolome Phenotype in Rats with Alcohol Withdrawal Syndrome.

The etiology of alcohol dependence is not completely understood. Increasing evidence reveals that gut microbiota dysbiosis is associated with certain psychiatric disorders, including alcoholism, through the "microbiota-gut-brain" axis. The aims of this study were to evaluate the effect of alcohol abuse on the gut microbiota, intestinal permeability and serum metabolic profile and to determine whether alcohol-induced alterations in gut microbiota are correlated with gut permeability and serum metabolic phenotype changes. 16S rRNA gene high-throughput sequencing and nontarget metabolomics techniques were applied in an alcohol-dependent rat model in the present study. The results showed that alcohol intake altered the composition and structure of the colonic microbiota, especially the relative abundances of commensal microbes in the families Lachnospiraceae and Prevotellaceae, which were significantly decreased. Alcohol-dependent rats developed gut leakiness and a serum metabolic phenotype disorder. The valine, leucine and isoleucine biosynthesis pathways and arginine and proline metabolism pathways were obviously influenced by alcohol intake. Moreover, alcohol consumption disturbed the brain's neurotransmitter homeostasis. Regression analysis showed that alcohol-induced colonic microbiota dysbiosis was strongly associated with increased intestinal permeability and serum metabolic phenotype and neurotransmitter disorders. These results revealed that gut microbiota dysbiosis and serum metabolite alteration might be a cofactor for developing of alcohol dependence. IMPORTANCE Gut microbiota dysbiosis is associated with certain psychiatric disorders through the "microbiota-gut-brain" axis. Here, we revealed that alcohol consumption induced colonic microbiota dysbiosis, increased intestinal permeability, and altered the serum metabolic phenotype in rats, and there was a strong correlation between gut microbiota dysbiosis and serum metabolite disorders. Thus, gut microbiota dysbiosis and serum metabolite alteration may be a cofactor for development of alcohol dependence.

Cloning of nitrite reductase gene from Haematococcus pluvialis and transcription and enzymatic activity analysis at different nitrate and phosphorus concentration.

Haematococcus pluvialis is an economic microalga to produce astaxathin. To study the nitrogen metabolic process of H. pluvialis, the transcription level and enzyme content of nitrite reductase at different nitrate and phosphorus concentrations were studied. In this research, nitrite reductase gene (nir) was first cloned from H. pluvialis, which consists of 5592 nucleotides and includes 12 introns. The cDNA ORF is 1776 bp, encoding a 592 amino acid protein with two conserved domains. Phylogenetic analysis showed that the nir gene in H. pluvialis had the highest affinity with other freshwater green algae. Nitrogen and phosphorus play an important role in the growth of H. pluvialis. The single factor experiments of nitrogen on growth conditions showed that the group with 0.2 g/L NaNO3 had a relative high biomass. The single factor experiments of phosphorus on growth conditions showed that the group with 0.06 g/L K2HPO4 had a relative high biomass. The transcription level and enzymatic activity of nitrite reductase were detected at different nitrate and phosphorus concentrations. In the absence of nitrogen and phosphorus in the medium, nitrite reductase activity is the highest. This research provides theoretical guidance for optimization of culture medium for H. pluvialis and also provides an experimental basis for understanding of nitrogen metabolism pathway in H. pluvialis.

Transcriptome Analysis in Haematococcus pluvialis: Astaxanthin Induction by High Light with Acetate and Fe2.

Haematococcus pluvialis is a commercial microalga, that produces abundant levels of astaxanthin under stress conditions. Acetate and Fe2+ are reported to be important for astaxanthin accumulation in H. pluvialis. In order to study the synergistic effects of high light stress and these two factors, we obtained transcriptomes for four groups: high light irradiation (HL), addition of 25 mM acetate under high light (HA), addition of 20 µM Fe2+ under high light (HF) and normal green growing cells (HG). Among the total clean reads of the four groups, 156,992 unigenes were found, of which 48.88% were annotated in at least one database (Nr, Nt, Pfam, KOG/COG, SwissProt, KEGG, GO). The statistics for DEGs (differentially expressed genes) showed that there were more than 10 thousand DEGs caused by high light and 1800-1900 DEGs caused by acetate or Fe2+. The results of DEG analysis by GO and KEGG enrichments showed that, under the high light condition, the expression of genes related to many pathways had changed, such as the pathway for carotenoid biosynthesis, fatty acid elongation, photosynthesis-antenna proteins, carbon fixation in photosynthetic organisms and so on. Addition of acetate under high light significantly promoted the expression of key genes related to the pathways for carotenoid biosynthesis and fatty acid elongation. Furthermore, acetate could obviously inhibit the expression of genes related to the pathway for photosynthesis-antenna proteins. For addition of Fe2+, the genes related to photosynthesis-antenna proteins were promoted significantly and there was no obvious change in the gene expressions related to carotenoid and fatty acid synthesis.

Transcriptome Sequencing of Gracilariopsis lemaneiformis to Analyze the Genes Related to Optically Active Phycoerythrin Synthesis.

Gracilariopsis lemaneiformis (aka Gracilaria lemaneiformis) is a red macroalga rich in phycoerythrin, which can capture light efficiently and transfer it to photosystemⅡ. However, little is known about the synthesis of optically active phycoerythrinin in G. lemaneiformis at the molecular level. With the advent of high-throughput sequencing technology, analysis of genetic information for G. lemaneiformis by transcriptome sequencing is an effective means to get a deeper insight into the molecular mechanism of phycoerythrin synthesis. Illumina technology was employed to sequence the transcriptome of two strains of G. lemaneiformis- the wild type and a green-pigmented mutant. We obtained a total of 86915 assembled unigenes as a reference gene set, and 42884 unigenes were annotated in at least one public database. Taking the above transcriptome sequencing as a reference gene set, 4041 differentially expressed genes were screened to analyze and compare the gene expression profiles of the wild type and green mutant. By GO and KEGG pathway analysis, we concluded that three factors, including a reduction in the expression level of apo-phycoerythrin, an increase of chlorophyll light-harvesting complex synthesis, and reduction of phycoerythrobilin by competitive inhibition, caused the reduction of optically active phycoerythrin in the green-pigmented mutant.

Cloning and transcription analysis of the nitrate reductase gene from Haematococcus pluvialis.

OBJECTIVES: To optimize the cultivation media for the growth rate of Haematococcus pluvialis and to study the transcription regulation of the algal nitrate reductase (NR), a key enzyme for nitrogen metabolism. RESULTS: The NR gene from H. pluvialis hd7 consists of 5636 nucleotides, including 14 introns. The cDNA ORF is 2718 bp, encoding a 905 aa protein with three conserved domains. The NR amino acids of H. pluvialis hd7 are hydrophilic and have similarity of 72% compared to that of Dunaliella. NR transcription increased with an increase of nitrate concentration from 0.4 to 1 g/l. A deficiency of nitrogen increased NR transcription significantly. The transcription level of NR increased at phosphorus concentrations from 0.08 to 0.2 g/l, with a maximum at 0.08 g/l. The optimum parameters of medium component for transcription of NR and growth of H. pluvialis were 0.3 g NaNO3/l, 0.045 g KH2PO4/l and 1.08 g sodium acetate/l. CONCLUSIONS: This study provides a better understanding of nitrate regulation in H. pluvialis.