Publications by authors named "Xuefei Cai"

Invasive fungal infections (IFIs) pose a significant threat to immunocompromised individuals, leading to considerable morbidity and mortality. Prompt and accurate diagnosis is essential for effective treatment. Here we develop a rapid molecular diagnostic method that involves three steps: fungal enrichment using affinity-magnetic separation (AMS), genomic DNA extraction with silicon hydroxyl magnetic beads, and detection through a one-pot system.

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Aurora kinase B (AURKB) overexpression promotes tumor initiation and development by participating in the cell cycle. In this study, we focused on the mechanism of AURKB in hepatocellular carcinoma (HCC) progression and on AURKB's value as a diagnostic and prognostic biomarker in HCC. We used data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) to analyze AURKB expression in HCC.

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Chronic hepatitis B virus (HBV) infection remains one of the major global public health concerns, and it develop into liver fibrosis, cirrhosis, and hepatocellular carcinoma. Recent evidence suggests that endosomal and autophagic vesicles are beneficial for HBV replication. However, it has not been well elucidated how HBV exploits such intracellular vesicle systems for its replication.

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  • - Flying insects maintain stability and control while flapping their wings, even when faced with strong winds and turbulence, which conventional controllers often struggle with.
  • - The study introduces a new type of controller for bumblebee hovering, using deep reinforcement learning to enhance stability during large disturbances.
  • - A detailed simulation environment was created to test this controller, which proved effective in quickly stabilizing the bumblebee's flight, showing potential for bio-inspired drone designs.
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Coronavirus disease 2019 (COVID-19) has become a global pandemic and poses a serious threat to human health. Many studies have shown that pre-existing nonalcoholic steatohepatitis (NASH) can worsen the clinical symptoms in patients suffering from COVID-19. However, the potential molecular mechanisms between NASH and COVID-19 remain unclear.

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The innate immune response is the first line of host defense against viral infections, but its role in immunity against SARS-CoV-2 remains unclear. By using immunoprecipitation coupled with mass spectroscopy, we observed that the E3 ubiquitin ligase TRIM21 interacted with the SARS-CoV-2 nucleocapsid (N) protein and ubiquitinated it at Lys . Upon determining the topology of the TRIM21-mediated polyubiquitination chain on N protein, we then found that polyubiquitination led to tagging of the N protein for degradation by the host cell proteasome.

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Hepatitis B surface antigen (HBsAg) loss and seroconversion, which is considered as functional cure of chronic Hepatitis B virus (HBV) infection, is rarely achieved even after long-term antiviral treatments. Therefore, new antiviral strategies interfering with other HBV replication steps are required, especially those that could efficiently inhibit HBsAg production. Here, we identified novel anti-HBV compounds that could potently block HBsAg expression from cccDNA by screening a natural compound library derived from Chinese traditional medical plants by a novel screening strategy.

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The hepatitis B virus (HBV) capsid assembly modulators (CAMs) have been developed as effective anti-HBV agents in the treatment of chronic HBV infection by targeting the HBV core protein and inducing the formation of aberrant or morphologically normal capsid. However, some CAMs have been observed adverse events such as ALT flares and rash. Therefore, finding new CAMs is of great importance.

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In this study, we investigated the mechanism of hepatitis B virus (HBV)-enveloped particle release. Specifically, we used preS1 as a bait protein to screen host proteins using mass spectroscopy, with the results of immunofluorescence, western blot, co-immunoprecipitation, isothermal titration calorimetry, and pull-down assays identifying glucose-regulated protein (GRP)78 as a specific target for preS1 binding. We employed transcriptome sequencing, enzyme-linked immunosorbent assays, and particle gel assays to investigate the mechanism of GRP78-mediated positive regulation of HBV-enveloped particle release.

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Background: Effective therapeutics and vaccines for coronavirus disease 2019 (COVID-19) are currently lacking because of the mutation and immune escape of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Based on the propagation characteristics of SARS-CoV-2, rapid and accurate detection of complete virions from clinical samples and the environment is critical for assessing infection risk and containing further COVID-19 outbreaks. However, currently applicable methods cannot achieve large-scale clinical application due to factors such as the high viral load, cumbersome virus isolation steps, demanding environmental conditions, and long experimental periods.

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  • Caspases are important proteases involved in cell death and inflammation, and new biosensors called NanoLocks, based on NanoLuc luciferase, were developed to detect their activity.
  • The NanoLock sensors operate on a dark-to-bright model and show significant activation responses, achieving a 1233-fold increase in signal with tobacco etch virus protease and over 500-fold with caspase 3.
  • These sensors outperform commercial kits in terms of signal-to-noise ratio and convenience, with successful testing in human cells and the establishment of a cell line for screening caspase 6 modulators.
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  • Hepatocellular carcinoma (HCC) is a major global health issue, with a pressing need for effective biomarkers to facilitate early diagnosis and improve patient survival rates.
  • This study focused on Exonuclease 1 (EXO1) to explore its potential as a diagnostic and prognostic biomarker in HCC by evaluating its expression levels across various cancer databases and analyzing its links with immune cell activity and genetic alterations.
  • Findings indicated that EXO1 expression is notably elevated in HCC tissues and serum, correlating with poor prognosis, tumor characteristics, and involvement in key cell proliferation pathways, thereby highlighting its significance in HCC diagnostics and treatment strategies.*
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Flying insects could perform robust flapping-wing dynamics under various environments while minimizing the high energetic cost by using elastic flight muscles and motors. Here we propose a fluid-structure interaction model that couples unsteady flapping aerodynamics and three-torsional-spring-based elastic wing-hinge dynamics to determine passive and active mechanisms (PAM) in bumblebee hovering. The results show that a strategy of active-controlled stroke, passive-controlled wing pitch and deviation enables an optimal elastic storage.

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  • Researchers have developed a new protein sensor called NanoSwitch, based on the modularized luciferase NanoLuc, that can detect antibodies in serum without washing steps, achieving results in just 45 minutes.
  • NanoSwitches exhibit high signal-to-noise ratios (S/N), reaching up to 42-fold for specific antibodies and over 200-fold for SARS-CoV-2 antibodies, allowing for effective differentiation between signals and background noise in a variety of serum samples.
  • The innovative design combines a turn-off mechanism with human serum albumin and a turn-on response triggered by specific antibodies, indicating potential for better sensor performance in detecting various pathogens like HIV and HCV.
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  • Scientists are looking for new ways to treat chronic hepatitis B by targeting something called the nucleocapsid, which helps the virus replicate.
  • They found small molecules called sulfonylpiperidine-3-carboxamides (SPCs) that can stop the virus from spreading by reducing the amount of HBV DNA in the body.
  • One specific SPC named C-39 was discovered to be very effective against the virus without harming healthy cells, making it a promising candidate for developing new antiviral medicines.
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Parasitoid wasps of the smallest flying insects with bristled wings exhibit sophisticated flight behaviors while challenging biomechanical limitations in miniaturization and low-speed flow regimes. Here, we investigate the morphology, material composition, and mechanical properties of the bristles of the parasitoid wasps . The bristles are extremely stiff and exhibit a high-aspect-ratio conical tubular structure with a large Young's modulus.

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(COVID-19) caused by the emerging (SARS-CoV-2) has set off a global pandemic. There is an urgent unmet need for safe, affordable, and effective therapeutics against COVID-19. In this regard, drug repurposing is considered as a promising approach.

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Liver cancer, the second most commonly diagnosed cancer, is associated with high mortality rates. is a member of the E2F transcription factor family. There are limited studies on the role of in hepatocellular carcinoma (HCC).

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  • Chronic hepatitis B virus (HBV) is a major global health issue, with covalently closed circular DNA (cccDNA) in the nucleus posing a challenge for curing chronic hepatitis B (CHB).
  • Recent findings highlight the role of histone modifications, particularly an active modification called histone succinylation (H3K122succ), in regulating the transcription of cccDNA.
  • The enzyme SIRT7 interacts with HBV proteins to desuccinylate histones and works alongside other enzymes to silence HBV transcription, suggesting that targeting cccDNA histone modifications could lead to new antiviral treatments.
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  • The study assesses the long-term durability of the immune response to SARS-CoV-2 about six months after infection, focusing on memory B cells and T cells.
  • Memory B cells specific to the virus's spike protein were found in low numbers in recovered individuals, particularly in those who had asymptomatic cases.
  • T cell responses were observed in both recovered COVID-19 patients and some healthy individuals, indicating potential cross-reactive immunity.
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Active flight control plays a crucial role in stabilizing the body posture of insects to stay aloft under a complex natural environment. Insects can achieve a closed-loop flight control by integrating the external mechanical system and the internal working system through manipulating wing kinematics according to feedback information from multiple sensors. While studies of proportional derivative/proportional integral derivative-based algorithms are the main subject to explore the continuous flight control mechanisms associated with insect flights, it is normally observed that insects achieve an intermittent spike firing in steering muscles to manipulate wings in flight control discontinuously.

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  • Current antiviral treatments for hepatitis B (HBV) manage the virus but do not fully eradicate it because they cannot eliminate cccDNA, highlighting the need for new curative strategies targeting the HBx protein.
  • Researchers screened 2,000 small-molecule compounds and identified dicoumarol, which significantly decreases HBx expression and exhibits strong antiviral activity against various HBV components in infected cells and a mouse model.
  • The study reveals that dicoumarol works by disrupting the protective relationship between NQO1 and HBx, thus inhibiting cccDNA transcription and contributing to a potential cure for chronic hepatitis B.
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Bimolecular fluorescence complementation (BiFC) is a popular method used to detect protein-protein interactions. For a BiFC assay, a fluorescent protein is usually split into two parts, and the fluorescence is recovered upon the interaction between the fused proteins of interest. As an elegant extension of BiFC, a tripartite superfold green fluorescent protein (sfGFP) system that has the advantages of low background fluorescence and small fusion tag size has been developed.

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Purpose: Emerging evidence indicates that dysfunction of long non-coding RNAs (lncRNAs) plays an essential role in the initiation and progression of hepatocellular carcinoma (HCC). In this study we investigated the potential roles and molecular mechanisms involving LINC01419 in HCC.

Methods: The expression of LINC01419 in 40 pairs of HCC/normal tissues and 6 HCC cell lines was detected by qRT-PCR.

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