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"Xiao, Qian"
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State equity participation and financing constraints of private enterprises in China: Based on the competitive pressure perspective
2023
This study examines the impact of state participation on the alleviation of financing constraints faced by private Chinese enterprises. The analysis is based on data collected from a sample of 2,256 private Chinese enterprises surveyed by the World Bank in 2011 and 2013, and a sample of 3,197 listed enterprises in China from 2009 to 2020. The empirical findings demonstrate that (1) State equity participation can effectively alleviate the financial constraints faced by enterprises, and its approach is to alleviate financing constraints by lessening the competitive pressure on mixed-equity enterprises. (2) Anxiety related to survival and development that arises from competitive pressures compels private enterprises to seek competitive advantages through new investments. Consequently, private enterprises’ demand for external capital has increased. However, the conversion of capital requirements into external financing applications has become increasingly challenging due to deficiencies in enterprises’ internal cognitive processes regarding financial information. (3) Heterogeneity analysis reveals that state equity participation has a more pronounced impact on alleviating the financing constraints faced by emerging, non-group, and non-listed enterprises.
Journal Article
PTI‐ETI synergistic signal mechanisms in plant immunity
2024
Summary Plants face a relentless onslaught from a diverse array of pathogens in their natural environment, to which they have evolved a myriad of strategies that unfold across various temporal scales. Cell surface pattern recognition receptors (PRRs) detect conserved elicitors from pathogens or endogenous molecules released during pathogen invasion, initiating the first line of defence in plants, known as pattern‐triggered immunity (PTI), which imparts a baseline level of disease resistance. Inside host cells, pathogen effectors are sensed by the nucleotide‐binding/leucine‐rich repeat (NLR) receptors, which then activate the second line of defence: effector‐triggered immunity (ETI), offering a more potent and enduring defence mechanism. Moreover, PTI and ETI collaborate synergistically to bolster disease resistance and collectively trigger a cascade of downstream defence responses. This article provides a comprehensive review of plant defence responses, offering an overview of the stepwise activation of plant immunity and the interactions between PTI‐ETI synergistic signal transduction.
Journal Article
Targeting NQO1/GPX4-mediated ferroptosis by plumbagin suppresses in vitro and in vivo glioma growth
2022
BackgroundFerroptosis has attracted increasing interest in cancer therapy. Emerging evidences suggest that naturally occurring naphthoquinones exhibit potent anti-glioma effects via various mechanisms.MethodsThe anti-glioma effects of plumbagin were evaluated by in vitro and in vivo experiments. Anti-glioma mechanism of plumbagin was studied by proteomics, flow cytometry, MDA assay, western blot, and RT-PCR. Gene knockdown/overexpression, molecular docking, PharmMappper database, and coimmunoprecipitation were used to study the targets of plumbagin.ResultsPlumbagin showed higher blood–brain barrier penetration ability than that of lapachol and shikonin and elicited significant growth inhibitory effects in vitro and in vivo. Ferroptosis was the main mechanism of plumbagin-induced cell death. Mechanistically, plumbagin significantly downregulated the protein and mRNA levels of xCT and decreased GPX4 protein levels. NAD(P)H quinone dehydrogenase 1 (NQO1) was revealed as a plumbagin predictive target using PharmMappper database and molecular docking. Plumbagin enhanced NQO1 activity and decreased xCT expression, resulting in NQO1-dependent cell death. It also induced GPX4 degradation via the lysosome pathway and caused GPX4-dependent cell death.ConclusionsPlumbagin inhibited in vitro and in vivo glioma growth via targeting NQO1/GPX4-mediated ferroptosis, which might be developed as a novel ferroptosis inducer or anti-glioma candidate.
Journal Article
Immunogenicity and safety of a recombinant adenovirus type-5-vectored COVID-19 vaccine in healthy adults aged 18 years or older: a randomised, double-blind, placebo-controlled, phase 2 trial
2020
This is the first randomised controlled trial for assessment of the immunogenicity and safety of a candidate non-replicating adenovirus type-5 (Ad5)-vectored COVID-19 vaccine, aiming to determine an appropriate dose of the candidate vaccine for an efficacy study.
This randomised, double-blind, placebo-controlled, phase 2 trial of the Ad5-vectored COVID-19 vaccine was done in a single centre in Wuhan, China. Healthy adults aged 18 years or older, who were HIV-negative and previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-free, were eligible to participate and were randomly assigned to receive the vaccine at a dose of 1 × 1011 viral particles per mL or 5 × 1010 viral particles per mL, or placebo. Investigators allocated participants at a ratio of 2:1:1 to receive a single injection intramuscularly in the arm. The randomisation list (block size 4) was generated by an independent statistician. Participants, investigators, and staff undertaking laboratory analyses were masked to group allocation. The primary endpoints for immunogenicity were the geometric mean titres (GMTs) of specific ELISA antibody responses to the receptor binding domain (RBD) and neutralising antibody responses at day 28. The primary endpoint for safety evaluation was the incidence of adverse reactions within 14 days. All recruited participants who received at least one dose were included in the primary and safety analyses. This study is registered with ClinicalTrials.gov, NCT04341389.
603 volunteers were recruited and screened for eligibility between April 11 and 16, 2020. 508 eligible participants (50% male; mean age 39·7 years, SD 12·5) consented to participate in the trial and were randomly assigned to receive the vaccine (1 × 1011 viral particles n=253; 5 × 1010 viral particles n=129) or placebo (n=126). In the 1 × 1011 and 5 × 1010 viral particles dose groups, the RBD-specific ELISA antibodies peaked at 656·5 (95% CI 575·2–749·2) and 571·0 (467·6–697·3), with seroconversion rates at 96% (95% CI 93–98) and 97% (92–99), respectively, at day 28. Both doses of the vaccine induced significant neutralising antibody responses to live SARS-CoV-2, with GMTs of 19·5 (95% CI 16·8–22·7) and 18·3 (14·4–23·3) in participants receiving 1 × 1011 and 5 × 1010 viral particles, respectively. Specific interferon γ enzyme-linked immunospot assay responses post vaccination were observed in 227 (90%, 95% CI 85–93) of 253 and 113 (88%, 81–92) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Solicited adverse reactions were reported by 183 (72%) of 253 and 96 (74%) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Severe adverse reactions were reported by 24 (9%) participants in the 1 × 1011 viral particles dose group and one (1%) participant in the 5 × 1010 viral particles dose group. No serious adverse reactions were documented.
The Ad5-vectored COVID-19 vaccine at 5 × 1010 viral particles is safe, and induced significant immune responses in the majority of recipients after a single immunisation.
National Key R&D Programme of China, National Science and Technology Major Project, and CanSino Biologics.
Journal Article
Revealing the chirality origin and homochirality crystallization of Ag14 nanocluster at the molecular level
2021
Although chirality is an ever-present characteristic in biology and some artificial molecules, controlling the chirality and demystifying the chirality origin of complex assemblies remain challenging. Herein, we report two homochiral Ag
14
nanoclusters with inherent chirality originated from identical rotation of six square faces on a Ag
8
cube driven by intra-cluster π···π stacking interaction between pntp
−
(Hpntp =
p-
nitrothiophenol) ligands. The spontaneous resolution of the racemic (SD/
rac
-Ag14a) to homochiral nanoclusters (SD/
L
-Ag14 and SD/
R
-Ag14) can be realized by re-crystallizing SD/
rac
-Ag14a in acetonitrile, which promotes the homochiral crystallization in solid state by forming C–H···O/N hydrogen bonds with nitro oxygen atoms in pntp
−
or aromatic hydrogen atoms in dpph (dpph = 1,6-bis(diphenylphosphino)hexane) on Ag
14
nanocluster. This work not only provides strategic guidance for the syntheses of chiral silver nanoclusters in an all-achiral environment, but also deciphers the origin of chirality at molecular level by identifying the special effects of intra- and inter-cluster supramolecular interactions.
The preparation of chiral monolayer-protected metal clusters is interesting for their potential applications in a variety of fields, including catalysis. Here, the authors synthesize chiral Ag
14
nanoclusters in an all-achiral environment, and decipher the origin of chirality at the molecular level; the solvent choice is key to achieve homochiral crystallization.
Journal Article
Stereoselective access to 5.5.0 and 4.4.1 bicyclic compounds through Pd-catalysed divergent higher-order cycloadditions
2020
Medium-sized rings, including those embedded in bridged and fused bicyclic scaffolds, are common core structures of myriad bioactive molecules. Among various synthetic strategies towards their synthesis, intermolecular higher-order cycloaddition provides great potential to build complex medium-sized rings from simple building blocks. Unfortunately, such transformations are often plagued with competitive reaction pathways and low levels of site- and stereoselectivity. Herein, we report catalyst-controlled divergent access to three classes of medium-sized bicyclic compounds in high efficiency and stereoselectivity, by palladium-catalysed cycloadditions of tropones with γ-methylidene-δ-valerolactones. Mechanistic studies and density functional theory calculations disclosed that the divergent reactions stem from the different reaction profiles of the diastereomeric intermediates. While one undergoes either O- or C-allylation to provide [5.5.0] or [4.4.1] bicyclic compounds, the unique conformation of the other diastereomer allows an unconventional alkene isomerization to deliver bridgehead alkene-containing bicyclo[4.4.1] compounds. The conversion of these products to diverse complex polycyclic scaffolds has also been demonstrated.Using readily accessible tropones and γ-methylidene-δ-valerolactones, the divergent synthesis of three classes of challenging [5.5.0] or [4.4.1] bicyclic systems has been achieved—with high efficiency and stereoselectivity—through Pd-catalysed higher-order cycloaddition. Mechanistic studies and density functional theory calculations indicate that the divergent reactions arise from the different reactivity of two diastereomeric intermediates.
Journal Article
Injection of amyloid-β to lateral ventricle induces gut microbiota dysbiosis in association with inhibition of cholinergic anti-inflammatory pathways in Alzheimer’s disease
by
Liu, Xiao-li
,
Qian, Xiao-hang
,
Tang, Hui-dong
in
Alzheimer's disease
,
Amyloidogenesis
,
Animal cognition
2022
Background
Alzheimer's disease (AD) is the most common neurodegenerative disease and its pathogenesis is still unclear. There is dysbiosis of gut microbiota in AD patients. More importantly, dysbiosis of the gut microbiota has been observed not only in AD patients, but also in patients with mild cognitive impairment (MCI). However, the mechanism of gut microbiota dysbiosis in AD is poorly understood. Cholinergic anti-inflammatory pathway is an important pathway for the central nervous system (CNS) regulation of peripheral immune homeostasis, especially in the gut. Therefore, we speculated that dysfunction of cholinergic anti-inflammatory pathway is a potential pathway for dysbiosis of the gut microbiota in AD.
Methods
In this study, we constructed AD model mice by injecting Aβ
1–42
into the lateral ventricle, and detected the cognitive level of mice by the Morris water maze test. In addition, 16S rDNA high-throughput analysis was used to detect the gut microbiota abundance of each group at baseline, 2 weeks and 4 weeks after surgery. Furthermore, immunofluorescence and western blot were used to detect alteration of intestinal structure of mice, cholinergic anti-inflammatory pathway, and APP process of brain and colon in each group.
Results
Aβ
1–42
i.c.v induced cognitive impairment and neuron damage in the brain of mice. At the same time, Aβ
1–42
i.c.v induced alteration of gut microbiota at 4 weeks after surgery, while there was no difference at the baseline and 2 weeks after surgery. In addition, changes in colon structure and increased levels of pro-inflammatory factors were detected in Aβ
1–42
treatment group, accompanied by inhibition of cholinergic anti-inflammatory pathways. Amyloidogenic pathways in both the brain and colon were accelerated in Aβ
1–42
treatment group.
Conclusions
The present findings suggested that Aβ in the CNS can induce gut microbiota dysbiosis, alter intestinal structure and accelerate the amyloidogenic pathways, which were related to inhibiting cholinergic anti-inflammatory pathways.
Journal Article
Dysbiosis of lower respiratory tract microbiome are associated with inflammation and microbial function variety
2019
Background
Lower respiratory tract (LRT) microbiome has been reported to associate with pulmonary diseases. Unregulated inflammation is an underlying cause of variable lung diseases. The lung microbiome may play an important role in the smoking-induced inflammatory lung diseases. What’s more, the function of microbiome may be more important for understanding how microbes interact with host. Our study aims to explore the effects of smoking on the lower respiratory tract microbiome, the association between variation of lower respiratory tract microbiome and inflammation and whether smoking exposure changes the function of lower respiratory tract microbime.
Methods
Forty male mice were randomly divided into smoking group and non-smoking group, and the smoking group was exposed to cigarette smoke for 2 h per day for 90 days. After experiment, the blood samples were collected to measure the concentration of interleukin-6 (IL-6) and C reactive protein (CRP) by ELISA. Lung tissue samples were used to detect the community and diversity of lower respiratory tract microbiome through 16S rRNA gene quantification and sequencing technology. ANOSIM and STAMP were performed to analyze the differences of the microbial community structure between smoking group and non-smoking group. SPSS 24.0 software was used to analyze the correlations between microbiome and inflammation mediators through scatter plots and Spearman correlation coefficient. Microbial metabolic function was predicted by PICRUSt based on the 16 s rRNA gene quantification and sequencing results. PATRIC database was searched for the potential pathogenic bacteria in lower respiratory tract.
Results
Our results suggested that smoking had markedly effects on the microbiota structure of lower respiratory tract based on Bray-Curtis distance (R
2
= 0.084,
p
= 0.005) and on unweighted uniFrac distance (R
2
= 0.131,
p
= 0.002). Smoking mainly affected the abundance of microbiome which belong to
Proteobacteria
phyla and
Firmicutes
phyla. Moreover, our results also found that smoking increased the abundance of
Acinetobacter
,
Bacillus
and
Staphylococcus
, which were defined as pathogenic bacteria. Inflammatory mediators were observed to associate with certain microbiome at every level. Most of microbiome which were associated with inflammation belonged to
Proteobacteria
phyla or
Firmicutes
phyla. Moreover, we found that the decreased microbiome in smoking group, including
Oceanospirillales
,
Desulfuromonadales, Nesterenkonia
, and
Lactobacillaceae,
all were negatively correlated with IL-6 or CRP. Based on the level of inflammation, the abundance of microbiome differs. At genus level,
Lactobacillus
,
Pelagibacterium, Geobacter
and
Zoogloea
were significantly higher in smoking group with lower IL-6 concentration. The abundance of microbiome was not observed any statistical difference in subgroups with different weight. Three dominant genus, defined as pathogen, were found higher in the smoking group. The microbial functional prediction analysis revealed that ABC-type transport systems, transcription factors, amino acide transport and metabolism, arginine and proline metabolism et al. were distinctively decreased in smoking group, while the proportions of replication, recombination and repair, ribosome, DNA repair and recombination proteins were increased in smoking group (q < 0.05).
Conclusions
Members of
Proteobacteria
phyla and
Firmicutes
phyla played an important role in the microbial community composition and keeping a relatively balanced homeostasis. Microbiome dysbiosis might break the balance of immune system to drive lung inflammation. There might exist potential probiotics in lower respiratory tract, such as
Lactobacillaceae
. The altered function of Lower respiratory tract microbiome under smoking exposure may affect the physiological homeostasis of host.
Journal Article
Transformation Mechanisms of Chemical Ingredients in Steaming Process of Gastrodia elata Blume
by
Liu, Shan-Shan
,
Li, Yun
,
Liu, Da-hui
in
Alcohol
,
Benzyl Alcohols - analysis
,
Chromatography, High Pressure Liquid - methods
2019
To explore the transformation mechanisms of free gastrodin and combined gastrodin before and after steaming of Gastrodia elata (G. elata), a fresh G. elata sample was processed by the traditional steaming method prescribed by Chinese Pharmacopoeia (2015 version), and HPLC-ESI-TOF/MS method was used to identify the chemical composition in steamed and fresh G. elata. Finally, 25 components were identified in G. elata based on the characteristic fragments of the compounds and the changes of the 25 components of fresh and steamed G. elata were compared by the relative content. Hydrolysis experiments and enzymatic hydrolysis experiments of 10 monomer compounds simulating the G. elata steaming process were carried out for the first time. As a result, hydrolysis experiments proved that free gastrodin or p-hydroxybenzyl alcohol could be obtained by breaking ester bond or ether bond during the steaming process of G. elata. Enzymatic experiments showed that steaming played an important role in the protection of gastrodin, confirming the hypothesis that steaming can promote the conversion of chemical constituents of G. elata—inhibiting enzymatic degradation. This experiment clarified the scientific mechanism of the traditional steaming method of G. elata and provided reference for how to apply G. elata decoction to some extent.
Journal Article
Molecular logic gates based on programmable self-assembly of DNA origami triangles for the detection of nucleic acid molecules
2025
The development of programmable DNA origami architectures with combinatorial complexity remains a critical challenge in molecular nanotechnology. This study develops a programmable nucleic acid detection platform by integrating DNA origami nanostructures with molecular logic gates, advancing the field of dynamic molecular computation. Triangular DNA origami modules, designed with edge-specific hybridization sites, successfully emulate Boolean logic operations (YES, AND, and OR gates) to achieve target-driven hierarchical self-assembly. As a proof of concept, significant biomarkers for early lung cancer diagnosis, were detected as targets, demonstrating the platform’s multiplexed analytical capabilities. By coupling the programmability of DNA nanostructures with molecular recognition logic, the platform constructs autonomous systems capable of interpreting biological signals via predefined algorithms. The modular architecture supports the scalability of multi-layered logic circuits, while atomic force microscopy (AFM) provides nanoscale-resolution validation of assemblies. Toehold-mediated strand displacement enables dynamic disassembly of structures, endowing the system with resettable and adaptive feedback functionalities. This technology lays the groundwork for transformative applications in precision diagnostics, synthetic biology, and adaptive nanomedicine.
Journal Article