Multi-omics panoramic analysis of HBV integration, transcriptional regulation, and epigenetic modifications in PLC/PRF/5 cell line.

The clearance or transcriptional silencing of integrated HBV DNA is crucial for achieving a functional cure in patients with chronic hepatitis B and reducing the risk of hepatocellular carcinoma development. The PLC/PRF/5 cell line is commonly used as an in vitro model for studying HBV integration. In this study, we employed a range of multi-omics techniques to gain a panoramic understanding of the characteristics of HBV integration in PLC/PRF/5 cells and to reveal the transcriptional regulatory mechanisms of integrated HBV DNA. Transcriptome long-read sequencing (ONT) was conducted to analyze and characterize the transcriptional activity of different HBV DNA integration sites in PLC/PRF/5 cells. Additionally, we collected data related to epigenetic regulation, including whole-genome bisulfite sequencing (WGBS), histone chromatin immunoprecipitation sequencing (ChIP-seq), and assays for transposase-accessible chromatin using sequencing (ATAC-seq), to explore the potential mechanisms involved in the transcriptional regulation of integrated HBV DNA. Long-read RNA sequencing analysis revealed significant transcriptional differences at various integration sites in the PLC/PRF/5 cell line, with higher HBV DNA transcription levels at integration sites on chr11, chr13, and the chr13/chr5 fusion chromosome t (13:5). Combining long-read DNA and RNA sequencing results, we found that transcription of integrated HBV DNA generally starts downstream of the SP1, SP2, or XP promoters. ATAC-seq data confirmed that chromatin accessibility has limited influence on the transcription of integrated HBV DNA in the PLC/PRF/5 cell line. Analysis of WGBS data showed that the methylation intensity of integrated HBV DNA was highly negatively correlated with its transcription level (r = -0.8929, p = 0.0123). After AzaD treatment, the transcription level of integrated HBV DNA significantly increased, especially for the integration chr17, which had the highest level of methylation. Through ChIP-seq data, we observed the association between histone modification of H3K4me3 and H3K9me3 with the transcription of integrated HBV DNA. Our findings suggest that the SP1, SP2 and XP in integrated HBV DNA, methylation level of surrounding host chromosome, and histone modifications affect the transcription of integrated HBV DNA in PLC/PRF/5 cells. This provides important clues for future studies on the expression and regulatory mechanisms of integrated HBV.

A dPCR-NIPT assay for detections of trisomies 21, 18 and 13 in a single-tube reaction-could it replace serum biochemical tests as a primary maternal plasma screening tool?

BACKGROUND: The next generation sequencing (NGS) based non-invasive prenatal test (NIPT) has outplayed the traditional serum biochemical tests (SBT) in screen of fetal aneuploidies with a high sensitivity and specificity. However, it has not been widely used as a primary screen tool due to its high cost and the cheaper SBT is still the choice for primary screen even with well-known shortages in sensitivity and specificity. Here, we report a multiplex droplet digital PCR NIPT (dPCR-NIPT) assay that can detect trisomies 21, 18 and 13 (T21, T18 and T13) in a single tube reaction with a better sensitivity and specificity than the SBT and a much cheaper price than the NGS-NIPT. METHODS: In this study, the dPCR-NIPT assay's non-clinical characteristics were evaluated to verify the cell free fetal DNA (cffDNA) fraction enrichment efficiencies, the target cell free DNA (cfDNA) concentration enrichment, the analytical sensitivity, and the sample quality control on the minimum concentration of cfDNA required for the assay. We validated the clinical performance for this assay by blindly testing 283 clinical maternal plasma samples, including 36 trisomic positive samples, from high risk pregnancies to access its sensitivity and specificity. The cost effectiveness of using the dPCR-NIPT assay as the primary screen tool was also analyzed and compared to that of the existing contingent strategy (CS) using the SBT as the primary screen tool and the strategy of NGS-NIPT as the first-tier screen tool in a simulating situation. RESULTS: For the non-clinical characteristics, the sample processing reagents could enrich the cffDNA fraction by around 2 folds, and the analytical sensitivity showed that the assay was able to detect trisomies at a cffDNA fraction as low as 5% and the extracted cfDNA concentration as low as 0.2 ng/µL. By testing the 283 clinical samples, the dPCR-NIPT assay demonstrated a detection sensitivity of 100% and a specificity of 95.12%. Compared to the existing CS and the NGS-NIPT as the first-tier screen strategy, dPCR-NIPT assay used as a primary screen tool followed by the NGS-NIPT rescreen is the most economical approach to screen pregnant women for fetal aneuploidies without sacrificing the positive detection rate. CONCLUSION: This is the first report on a dPCR-NIPT assay, consisting of all the necessary reagents from sample processing to multiplex dPCR amplification, can detect T21, T18 and T13 in a single tube reaction. The study results reveal that this assay has a sensitivity and specificity superior to the SBT and a cost much lower than the NGS-NIPT. Thus, from both the test performance and the economic benefit points of views, using the dPCR-NIPT assay to replace the SBT as a primary screen tool followed by the NGS-NIPT rescreen would be a better approach than the existing CS for detection of fetal aneuploidies in maternal plasma.

Gastrointestinal symptoms of 95 cases with SARS-CoV-2 infection.

OBJECTIVE: To study the GI symptoms in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients. DESIGN: We analysed epidemiological, demographic, clinical and laboratory data of 95 cases with SARS-CoV-2 caused coronavirus disease 2019. Real-time reverse transcriptase PCR was used to detect the presence of SARS-CoV-2 in faeces and GI tissues. RESULTS: Among the 95 patients, 58 cases exhibited GI symptoms of which 11 (11.6%) occurred on admission and 47 (49.5%) developed during hospitalisation. Diarrhoea (24.2%), anorexia (17.9%) and nausea (17.9%) were the main symptoms with five (5.3%), five (5.3%) and three (3.2%) cases occurred on the illness onset, respectively. A substantial proportion of patients developed diarrhoea during hospitalisation, potentially aggravated by various drugs including antibiotics. Faecal samples of 65 hospitalised patients were tested for the presence of SARS-CoV-2, including 42 with and 23 without GI symptoms, of which 22 (52.4%) and 9 (39.1%) were positive, respectively. Six patients with GI symptoms were subjected to endoscopy, revealing oesophageal bleeding with erosions and ulcers in one severe patient. SARS-CoV-2 RNA was detected in oesophagus, stomach, duodenum and rectum specimens for both two severe patients. In contrast, only duodenum was positive in one of the four non-severe patients. CONCLUSIONS: GI tract may be a potential transmission route and target organ of SARS-CoV-2.

Circ-PVT1/miR-106a-5p/HK2 axis regulates cell growth, metastasis and glycolytic metabolism of oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is the most commonly diagnosed oral cavity malignancy. A handful of circular RNAs (circRNAs) have recently shown to act as crucial regulators in OSCC, including circRNA plasmacytoma variant translocation 1 (circ-PVT1). However, further exploration is still needed for the underlying functional mechanism behind circ-PVT1 in OSCC. The levels of circ-PVT1, microRNA-106a-5p (miR-106a-5p) and hexokinase II (HK2) were all examined applying with quantitative real-time polymerase chain reaction (qRT-PCR). Cellular analyses (cell viability, apoptosis, metastasis and glycolysis) in vitro were performed via cell counting kit-8 (CCK-8), flow cytometry, transwell migration/invasion assays and glycolysis-related indications (glucose consumption, lactate production and ATP/ADP ratio). HK2 protein level was measured through western blot. Dual-luciferase reporter assay was conducted to study the interplay between miR-106a-5p and circ-PVT1 or HK2. Xenografts in mice were used for analyzing circ-PVT1 in vivo. Circ-PVT1 was expressed with abnormal high level while miR-106a-5p was down-regulated in OSCC tissues and cells. Circ-PVT1 knockdown reduced OSCC cell growth, metastasis and glycolysis. Moreover, circ-PVT1 acted in OSCC by functioning as a miR-106a-5p sponge. HK2 was a target of miR-106a-5p and miR-106a-5p played an anti-tumor role in OSCC by inhibiting HK2. Furthermore, HK2 could be regulated by circ-PVT1 via targeting miR-106a-5p. In xenograft models of mice, down-regulation of circ-PVT1 retarded tumorigenesis via the miR-106a-5p/HK2 axis. Our works suggested that circ-PVT1 directly combined with miR-106a-5p to mediate HK2 level, consequently regulating cellular behaviors in OSCC as a tumor promoter.

The Antarctic sea ice alga Chlamydomonas sp. ICE-L provides insights into adaptive patterns of chloroplast evolution.

BACKGROUND: The ice alga Chlamydomonas sp. ICE-L is the main contributor to primary productivity in Antarctic sea ice ecosystems and is well adapted to the extremely harsh environment. However, the adaptive mechanism of Chlamydomonas sp. ICE-L to sea-ice environment remains unclear. To study the adaptive strategies in Chlamydomonas sp. ICE-L, we investigated the molecular evolution of chloroplast photosynthetic genes that are essential for the accumulation of carbohydrate and energy living in Antarctic sea ice. RESULTS: The 60 chloroplast protein-coding genes of Chlamydomonas sp. ICE-L were obtained, and the branch-site test detected significant signatures of positive selection on atpB, psaB, and rbcL genes in Chlamydomonas sp. ICE-L associated with the photosynthetic machinery. These positively selected genes were further identified as being under convergent evolution between Chlamydomonas sp. ICE-L and the halotolerant alga Dunaliella salina. CONCLUSIONS: Our study provides evidence that the phototrophic component of Chlamydomonas sp. ICE-L exhibits adaptive evolution under extreme environment. The positive Darwinian selection operates on the chloroplast protein-coding genes of Antarctic ice algae adapted to extreme environment following functional-specific and lineages-specific patterns. In addition, three positively selected genes with convergent substitutions in Chlamydomonas sp. ICE-L were identified, and the adaptive modifications in these genes were in functionally important regions of the proteins. Our study provides a foundation for future experiments on the biochemical and physiological impacts of photosynthetic genes in green algae.

Enhanced photoluminescence of the Ca0.8 Zn0.2 TiO3 :0.05% Pr3+ phosphor by optimized hydrothermal conditions.

The red-emitting phosphor Ca0.8 Zn0.2 TiO3 :Pr3+ was synthesized using an ethylene glycol (EG)-assisted hydrothermal method. The effects of additional amounts of and order of adding EG, plus hydrothermal temperature, time, and pH on the composition, morphology and optical properties of the titanate phosphors were studied. The crystalline phases of the titanate phosphors were confirmed to be constituted of a series of co-existing CaTiO3 , Zn2 TiO4 and Ca2 Zn4 Ti16 O38 compounds in various proportions that were visualized using an X-ray diffractometer (XRD). The optical properties of the phosphors were studied using photoluminescence spectra and UV-visible spectroscopy. The results show that the impurities Zn2 TiO4 :Pr3+ and Ca2 Zn4 Ti16 O38 :Pr3+ significantly contributed to the enhancement of an absorption band around 380 nm. The optimum Ca0.8 Zn0.2 TiO3 :Pr3+ phosphor consisting of appropriate amounts of CaTiO3 , Ca2 Zn4 Ti16 O38 and Zn2 TiO4 in three phases was achieved by controlling the hydrothermal conditions, and the obtained red phosphor exhibited the highest red emission (1 D2  â†’ 3 H4 transition of Pr3+ ) with an ideal chromaticity coordinate located at (x = 0.667, y = 0.332) under 380 nm excitation.

Flexural Performance and Stress Calculation of External Prestressed Fiber-Reinforced Polymer-Bar-Strengthened One-Way Concrete Slabs.

External prestressing is widely employed in structural strengthening engineering due to its numerous advantages. However, external prestressed steel bars are prone to corrosion when exposed to the service environment. This paper is dedicated to examining the use of fiber-reinforced polymer (FRP) bars as external prestressing materials to strengthen one-way concrete slabs. Five one-way concrete slabs were strengthened with externally prestressed FRP bars with different prestress levels and different amounts of FRP bars, while one non-strengthened slab was used for comparison. The effects of strengthening on the flexural behavior, specifically the cracking load, ultimate load, stiffness and failure mode, were analyzed systematically. Moreover, the ductility and cost-benefit optimizing properties of the reinforcing design were discussed. The results show that external prestressed FRP bars significantly improve the cracking load, ultimate load and stiffness of one-way concrete slabs. The absence of a bond between the concrete and FRP bars overcomes the brittleness of the FRP bars, while the strengthened slabs exhibit satisfactory ductility and a higher post-yield stiffness and bearing capacity. Additionally, the cost/benefit ratio is optimized by increasing the prestress level, while a higher number of prestressed FRP bars is beneficial to ductility. Finally, a method for calculating the stress in prestressed FRP bars at ultimate loads was proposed. Irrespective of the prestressing material, this method is applicable to both strengthened beams and one-way slabs.

Detoxification of copper and zinc from anaerobic digestate effluent by indigenous bacteria: Mechanisms, pathways and metagenomic analysis.

The presence of organic-complexed copper and zinc in anaerobic digestate effluent (ADE) poses persistent ecological toxicity. This study investigated the detoxification performance and biotic responses of indigenous bacteria against ethylene diamine tetraacetic acid (EDTA)-complexed Cu(II) and Zn(II). Heavy metals (HMs) stress induced reactive oxygen species (ROS) generation and enhanced extracellular polymeric substances (EPS) secretion. At a Cu(II) influent concentration of 20.0 mg·L-1, indigenous bacteria removed 88.2% of Cu(II) within nine days. The majority of copper and zinc sequestered by bacteria were stored in the cell envelope, with over 50% of copper and 60% of zinc being immobilized. Transmission electron microscopy mapping (TEM-mapping) revealed significant mineralization of copper and zinc on the cell wall. Proteins abundant in EPS, alongside humic acid-like substances, effectively adsorbed HMs. Indigenous bacteria exhibited the capacity to reduce cupric to the cuprous state and cupric is preferentially reduced to cuprous before reaching reducing capacity saturation. Sulfur precipitation emerges as a crucial pathway for Zn(II) removal. Metagenomic analysis indicated that indigenous bacteria upregulated genes related to HMs homeostasis, efflux, and DNA repair, enhancing its resistance to high concentrations HMs. This study provided theoretical guidance for employing bacterial consortia to eliminate HMs in complex aquatic environments.

Elimination of copper obstacle factor in anaerobic digestion effluent for value-added utilization: Performance and resistance mechanisms of indigenous bacterial consortium.

The presence of excessive residual Cu(II), a high-risk heavy metal with potential toxicity and biomagnification property, substantially impede the value-added utilization of anaerobic digestion effluent (ADE). This study adapted indigenous bacterial consortium (IBCs) to eliminate Cu(II) from ADE, and their performances and resistance mechanisms against Cu(II) were analyzed. Results demonstrated that when the Cu(II) exposure concentration exceeded 7.5 mg/L, the biomass of IBCs decreased significantly, cells produced a substantial amount of ROS and EPS, at which time the intracellular Cu(II) content gradually decreased, while Cu(II) accumulation within the EPS substantially increased. The combined features of a high PN/PS ratio, a reversed Zeta potential gradient, and abundant functional groups within EPS collectively render EPS a primary diffusion barrier against Cu(II) toxicity. Mutual physiological and metagenomics analyses reveal that EPS synthesis and secretion, efflux, DNA repair along with coordination between each other were the primary resistance mechanisms of IBCs against Cu(II) toxicity. Furthermore, IBCs exhibited enhanced resistance by enriching bacteria carrying relevant resistance genes. Continuous pretreatment of actual ADE with IBCs at a 10-day hydraulic retention time (HRT) efficiently eliminated Cu(II) concentration from 5.01 mg/L to ∼0.68 mg/L by day 2. This elimination remained stable for the following 8 days of operation, further validated their good Cu(II) elimination stability. Notably, supplementing IBCs with 200 mg/L polymerized ferrous sulfate significantly enhanced their settling performance. By elucidating the intricate interplay of Cu(II) toxicity and IBC resistance mechanisms, this study provides a theoretical foundation for eliminating heavy metal barriers in ADE treatment.

Hepatitis B virus enhancer 1 activates preS1 and preS2 promoters of integrated HBV DNA impairing HBsAg secretion.

Background & Aims: The expression of HBsAg from integrated HBV DNA limits the achievement of functional cure for chronic hepatitis B. Thus, characterising the unique expression and secretion of HBsAg derived from integrated HBV DNA is of clinical significance. Methods: A total of 563 treatment-naive patients and 62 functionally cured patients were enrolled, and HBsAg and HBcAg immunohistochemistry of their liver biopsy tissues was conducted followed by semi-quantitative analysis. Then, based on stratified analysis of HBeAg-positive and -negative patients, long-read RNA sequencing analysis, as well as an in vitro HBV integration model, we explored the HBsAg secretion characteristics of integrated HBV DNA and underlying mechanisms. Results: In contrast to the significantly lower serum HBsAg levels, no significant decrease of intrahepatic HBsAg protein was observed in HBeAg-negative patients, as compared with HBeAg-positive patients. The results of long-read RNA sequencing of liver tissues from patients with chronic HBV infection and in vitro studies using integrated HBV DNA mimicking dslDNA plasmid revealed that, the lower HBsAg secretion efficiency seen in HBeAg-negative patients might be attributed to an increased proportion of preS1 mRNA derived from integrated HBV DNA instead of covalently closed circular DNA. The latter resulted in an increased L-HBsAg proportion and impaired HBsAg secretion. Enhancer 1 (EnhI) in integrated HBV DNA could retarget preS1 (SP1) and preS2 (SP2) promoters to disrupt their transcriptional activity balance. Conclusions: The secretion of HBsAg originating from integrated HBV DNA was impaired. Mechanistically, functional deficiency of core promoter leads to retargeting of EnhI and thus uneven activation of the SP1 over the SP2 promoter, resulting in an increase in the proportion of L-HBsAg. Impact and implications: Integrated hepatitis B virus (HBV) DNA can serve as an important reservoir for HBV surface antigen (HBsAg) expression, and this limits the achievement of a functional cure. This study revealed that secretion efficiency is lower for HBsAg derived from integrated HBV DNA than HBsAg derived from covalently closed circular DNA, as determined by the unique sequence features of integrated HBV DNA. This study can broaden our understanding of the role of HBV integration and shed new light on antiviral strategies to facilitate a functional cure. We believe our results are of great general interest to a broad audience, including patients and patient organisations, the medical community, academia, the life science industry and the public.

Silencing of GATA6 suppresses SW1990 pancreatic cancer cell growth in vitro and up-regulates reactive oxygen species.

BACKGROUND/AIMS: Pancreatic cancer has the worst prognosis of any gastrointestinal cancer with a mortality rate approaching its incidence. Previous studies have indicated that GATA6 plays a key role in organ development and function, and that abnormal expression of GATA6 may induce tumorigenesis. Meanwhile, it has been reported that generation of reactive oxygen species contributes to carcinogenesis. In this study, we set out to study the role of GATA6 expression on proliferation and apoptosis of pancreatic cancer cells and the role of reactive oxygen species. METHODS: Four target miRNA sequences against GATA6 mRNA were synthesized and used to transfect SW1990 cells. Then, GATA6 expression in SW1990 cells was examined by western blot and quantative real-time polymerase chain reaction. Cell proliferation was examined by WST-8 and colony formation assay. Cell cycle progression and apoptosis were measured by flow cytometry. We also measured the generation of reactive oxygen species by immunofluorescence and flow cytometry. RESULTS: RNA interference against GATA6 successfully inhibited mRNA and protein expression of GATA6 in the SW1990 pancreatic cancer cell line. Silencing of GATA6 by RNA interference inhibited cell proliferation and increased apoptosis of SW1990, and enhanced the expression of reactive oxygen species. CONCLUSIONS: These results suggest that the RNA interference approach against GATA6 may be an effective therapeutic approach for treatment of pancreatic cancer.

A novel hepatitis B virus capsid assembly modulator QL-007 inhibits HBV replication and infection through altering capsid assembly.

The core protein allosteric modulators (CpAMs) have shown great potential as highly effective antiviral drugs against hepatitis B virus (HBV) in preclinical studies and clinical trials. In this study, we evaluated a small molecule compound called QL-007, which could potentially influence capsid assembly, using HBV replicated and susceptible cell models as well as mice infected with rAAV-HBV. QL-007 significantly inhibited HBV replication in a dose-dependent manner both in vitro and in vivo, resulting in significant decreases in HBV DNA, 3.5 kb HBV RNA and HBeAg. Furthermore, QL-007 not only induced the formation of misshaped Cp149 capsids but also possessed the capability to disassemble HBV capsids. It is noteworthy that QL-007 effectively reduced cccDNA biosynthesis in de novo infections. Mechanistically, QL-007 blocked the encapsidation of pgRNA and induced aberrant polymers assembly at concentrations ≥100 nM, while having no impact on the stability of core proteins. In conclusion, our findings underscore the potential of QL-007 as an effective agent against HBV replication and introduce it as a novel CpAM for the antiviral treatment of chronic hepatitis B.

Mechanisms of promotion in the heterotrophic growth of Chlorella vulgaris by the combination of sodium acetate and hydrolysate of broken rice.

In order to reduce the culture cost and increase the growth rate of heterotrophic Chlorella vulgaris, the effects of hydrolysate of broken rice (HBR) combined with sodium acetate on its growth were evaluated. Results showed that the addition of 0.4 g/L of sodium acetate could stabilize the pH of the medium via the co-metabolism of acetate, ammonia and nitrate by Chlorella vulgaris. Meanwhile, isocitrate lyase activity increased threefold, which further promoted the glyoxylate cycle and the citric acid cycle, which finally provided more energy and metabolic precursors for cell growth. The biomass production (5.04 g/L), biomass productivity (1.65 g/L/day) and protein content (64.14 %) were 1.56, 1.81 and 1.77 times higher than the glucose group. This study demonstrated that HBR combined with sodium acetate could effectively promote the heterotrophic metabolism of microalgae, which provided scientific basis and guidance for industrial production of high-value products using Chlorella vulgaris as a fermentation platform.

A standardized assay for the quantitative detection of serum HBV RNA in chronic hepatitis B patients.

Serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) is a surrogate marker for reflecting the transcriptional activity of covalently closed circular DNA. However, there is still no standardized assay for the quantitative detection of serum HBV RNA in chronic hepatitis B patients. In this study, quantitative polymerase chain reactions for detecting the preC/C-RNA (preC/C region HBV pgRNA), SF-RNA (splicing variants-free pgRNA) and XR-RNA (X region remained pgRNA) regions were set up. The dynamic changes of serum pgRNA splicing variants and 3' terminal truncations were analysed in three retrospective cohorts: 35 treatment-naive chronic HBV-infected patients (cohort A), 52 chronic hepatitis B (CHB) patients who received nucleos(t)ide analogs (NAs) therapy for 48 weeks (cohort B) and eight CHB patients who are under long-term NAs treatment (cohort C). The accuracy and sensitivity of HBV RNA detection were assessed by the National Standard of HBV RNA. We confirmed that high proportions of pgRNA splicing variants and 3' terminal truncations were present and significantly affect the quantitative detection of serum HBV RNA in both treatment-naive and NAs-treated CHB patients. To achieve the higher accuracy and sensitivity on the detection of HBV RNA level, the primers and probes should be designed at the 5' terminal region of HBV genome and outside the mainly spliced sequence of pgRNA, especially for CHB patients under long-term NAs treatment. This study would help to better understand the significance of the pgRNA splicing variants and 3' terminal truncations, and further guide the clinical detection of serum HBV RNA.

Young plasma attenuates cognitive impairment and the cortical hemorrhage area in cerebral amyloid angiopathy model mice.

BACKGROUND: Cerebral amyloid angiopathy (CAA) is characterized by the deposition of ß-amyloid (Aß) in leptomeningeal vessels and penetrating arterioles. Intracerebral hemorrhage (ICH) is one of the most destructive complications in CAA. Young plasma has been shown to improve cognitive, learning, and memory functions in Alzheimer's disease (AD) model mice and is a new potential therapy. However, it is not clear whether young plasma can reduce cerebral hemorrhage and improve the prognosis of neurological function in APP/PS1 (which express APP695swe and PS1-dE9 mutations) mice with CAA disease. METHODS: The Y-maze, new object recognition (NOR), forced swimming, open field, sucrose consumption, and corner tests were used to evaluate the learning and memory, cognitive ability, and emotional changes in CAA model mice. The effect of young plasma on neurogenesis was analyzed by immunofluorescence. The level of Aß in the cerebral cortex and hippocampus of mice was measured by enzyme-linked immunosorbent assay (ELISA). Finally, the area of cortical hemorrhage in mice was analyzed by fast blue-staining. RESULTS: We proved that young plasma improved cognition, learning and memory impairment, and anxiety in CAA model mice, prevented neuronal apoptosis, and enhanced neurogenesis in APP/PS1 mice. However, young plasma did not reduce the level of Aß in the cortex and hippocampus of APP/PS1 mice. We also found that young plasma reduced the area of cerebral hemorrhage in APP/PS1 mice. CONCLUSIONS: Our results show that young plasma can improve learning and memory, cognitive impairment, and anxiety in CAA model mice and can reduce the area of cortical hemorrhage.

Simulation Analysis of Cluster Effect of High-Shear Low-Pressure Grinding with Flexible Abrasive Tools.

Based on the clustering effect of shear-thickening fluids (STFs), a high-shear low-pressure flexible grinding wheel has been developed. In order to explore the material removal mechanism, the coupled Eulerian-Lagrangian (CEL) method is adopted to simulate the novel grinding process. The simulation results show that particle clustering effects do occur at the tangential and bottom positions of the micro-convex peak when it instantaneously strikes the workpiece surface. The particle clusters drive the harder abrasive particles to resist the strong interactions of micro-convex peaks. The micro-convex peaks are removed due to the cutting effect of the harder abrasive particles. Compared with traditional grinding, the ratio of tangential force to normal force for the high-shear low-pressure flexible grinding wheel is improved. The various trends in force ratio are consistent with the experimental results, which verifies the effectiveness of high-shear low-pressure grinding.

Enhancement of nutrients removal and biomass accumulation of Chlorella vulgaris in pig manure anaerobic digestate effluent by the pretreatment of indigenous bacteria.

High concentrations of pollutants in pig manure anaerobic digestate effluent (PMADE) can severely inhibit microalgal growth. In this study, two types of PMADE (PMADE-1, PMADE-2) were pretreated with indigenous bacteria which were selected from PMADE to alleviate their inhibition for the growth of Chlorella vulgaris. Indigenous bacteria could decrease 34.04% and 47.80% of total phosphorus (TP) and turbidity in PMADE-1, and 80.81%, 43.27%, and 57.51% of COD, TP, and turbidity in PMADE-2, respectively. And no significant reduction of NH4+-N in both PMADE after 5 days pretreatment occurred. C. vulgaris failed to grow in unpretreated PMADE-2. Pretreatment of PMADE with indigenous bacteria could remarkably promote nutrients removal and cell growth of C. vulgaris compared to the unpretreated PMADE. The order of abiotic stress in the studied PMADE was COD > NH4+-N > turbidity, and it is appropriate to pretreat the PMADE with indigenous bacteria for 2-3 days.

Fecal multi-omics analysis reveals diverse molecular alterations of gut ecosystem in COVID-19 patients.

Gut ecosystem has profound effects on host physiology and health. Gastrointestinal (GI) symptoms were frequently observed in patients with COVID-19. Compared with other organs, gut antiviral response can result in more complicated immune responses because of the interactions between the gut microbiota and host immunity. However, there are still large knowledge gaps in the impact of COVID-19 on gut molecular profiles and commensal microbiome, hindering our comprehensive understanding of the pathogenesis of SARS-CoV-2 and the treatment of COVID-19. We performed longitudinal stool multi-omics profiling to systemically investigate the molecular phenomics alterations of gut ecosystem in COVID-19. Gut proteomes of COVID-19 were characterized by disturbed immune, proteolysis and redox homeostasis. The expression and glycosylation of proteins involved in neutrophil degranulation and migration were suppressed, while those of proteases were upregulated. The variable domains of Ig heavy chains were downregulated and the overall glycosylation of IgA heavy chain constant regions, IgGFc-binding protein, and J chain were suppressed with glycan-specific variations. There was a reduction of beneficial gut bacteria and an enrichment of bacteria derived deleterious metabolites potentially associated with multiple types of diseases (such as ethyl glucuronide). The reduction of Ig heave chain variable domains may contribute to the increase of some Bacteroidetes species. Many bacteria ceramide lipids with a C17-sphingoid based were downregulated in COVID-19. In many cases, the gut phenome did not restore two months after symptom onset. Our study indicates widely disturbed gut molecular profiles which may play a role in the development of symptoms in COVID-19. Our findings also emphasis the need for ongoing investigation of the long-term gut molecular and microbial alterations during COVID-19 recovery process. Considering the gut ecosystem as a potential target could offer a valuable approach in managing the disease.

Effects of Groove and Steel Fiber on Shear Properties of Concrete with Recycled Coarse Aggregate.

In this paper, a series of shear specimens with or without groove were manufactured to mainly analyze the effects of grooves (or shear section height) and steel fibers on the shear properties of concrete with recycled coarse aggregate through double-side direct shear test. In addition, the relationship between the shear strength and the compressive strength and splitting tensile strength of steel fiber reinforced concrete with recycled coarse aggregate (SFRCAC) was also discussed. The experimental results showed that the peak load, deformation corresponding to the peak load and calculated shear strength of the specimens with grooves were lower than those of the specimens without grooves. The steel fiber and recycled coarse aggregate (RCA) had a significant effect on the shear properties of SFRCAC. As the volume content of steel fibers increased, the shear strength of SFRCAC and the corresponding deformation increased gradually. With the replacement ratio of RCA increasing, the shear strength of SFRCAC decreased but the corresponding deformation increased gradually. Finally, the formula for calculating the shear strength of SFRCAC was proposed by analyzing and fitting the test results and the data of related literature.