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"Liang, Li-Jun"
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Impact of environmental factors on the emergence, transmission and distribution of Toxoplasma gondii
Toxoplasma gondii
is an obligate intracellular protozoan that poses a great threat to human health and economic well-being worldwide. The effects of environmental factors such as changing climate and human activities on the ecology of this protozoan are being discovered. Accumulated evidence shows that changes of these environmental factors can exert influence on the occurrence, transmission and distribution of
T. gondii.
This article reviews studies from different geographical regions with varying climates, social cultures and animal welfare standards. It aims to illustrate how these environmental factors work, highlighting their importance in influencing the ecology of
T. gondii
, as well as providing clues which may contribute to preventing transmission of this important zoonotic pathogen.
Journal Article
Role of Glial Cell-Derived Oxidative Stress in Blood-Brain Barrier Damage after Acute Ischemic Stroke
The integrity of the blood-brain barrier (BBB) is mainly maintained by endothelial cells and basement membrane and could be regulated by pericytes, neurons, and glial cells including astrocytes, microglia, oligodendrocytes (OLs), and oligodendrocyte progenitor cells (OPCs). BBB damage is the main pathological basis of hemorrhage transformation (HT) and vasogenic edema after stroke. In addition, BBB damage-induced HT and vasogenic edema will aggravate the secondary brain tissue damage. Of note, after reperfusion, oxidative stress-initiated cascade plays a critical role in the BBB damage after acute ischemic stroke (AIS). Although endothelial cells are the target of oxidative stress, the role of glial cell-derived oxidative stress in BBB damage after AIS also should receive more attention. In the current review, we first introduce the physiology and pathophysiology of the BBB, then we summarize the possible mechanisms related to BBB damage after AIS. We aim to characterize the role of glial cell-derived oxidative stress in BBB damage after AIS and discuss the role of oxidative stress in astrocytes, microglia cells and oligodendrocytes in after AIS, respectively.
Journal Article
Research and application of digital measure management and control technology for characteristic low-efficiency gas wells in Gas Field A
Gas Field A has entered the middle and late stages of development, with the number of low-efficiency wells increasing year by year. In the Songliao old area, extreme cold weather (-40°C) has led to 45% of gas wells experiencing freeze-offs. In the Sichuan-Chongqing exploration area, high formation water volume and salinity (35 × 10 4 mg/L) have resulted in 44% of wells suffering from liquid loading. The annual demand for thawing and foam drainage measures reaches 3,000 well interventions. The large workload and high costs of maintenance make it difficult to ensure the timing and frequency of interventions, affecting the gas recovery efficiency. By establishing an integrated analysis and remote monitoring platform that combines “condition diagnosis, measure adjustment, and remote monitoring,” the use of “freeze-off prediction + precise chemical injection” has improved the opening rate of freeze-off wells. The application of “optimized foam drainage injection parameters” ensures the stable production of liquid-loaded wells. The implementation of this technology is expected to generate over 20 million yuan in benefits and enhance the analysis, decision-making, and control capabilities of gas production processes under extreme weather and production conditions.
Journal Article
The evolutionary features and roles of single nucleotide variants and charged amino acid mutations in influenza outbreaks during NPI period
The epidemic and outbreaks of influenza B Victoria lineage (Bv) during 2019–2022 led to an analysis of genetic, epitopes, charged amino acids and Bv outbreaks. Based on the National Influenza Surveillance Network (NISN), the Bv 72 strains isolated during 2019–2022 were selected by spatio-temporal sampling, then were sequenced. Using the Compare Means, Correlate and Cluster, the outbreak data were analyzed, including the single nucleotide variant (SNV), amino acid (AA), epitope, evolutionary rate (ER), Shannon entropy value (SV), charged amino acid and outbreak. With the emergence of COVID-19, the non-pharmaceutical interventions (NPIs) made Less distant transmission and only Bv outbreak. The 2021–2022 strains in the HA genes were located in the same subset, but were distinct from the 2019–2020 strains (
P
< 0.001). The codon G → A transition in nucleotide was in the highest ratio but the transversion of C → A and T → A made the most significant contribution to the outbreaks, while the increase in amino acid mutations characterized by polar, acidic and basic signatures played a key role in the Bv epidemic in 2021–2022. Both ER and SV were positively correlated in HA genes (
R
= 0.690) and NA genes (
R
= 0.711), respectively, however, the number of mutations in the HA genes was 1.59 times higher than that of the NA gene (2.15/1.36) from the beginning of 2020 to 2022. The positively selective sites 174, 199, 214 and 563 in HA genes and the sites 73 and 384 in NA genes were evolutionarily selected in the 2021–2022 influenza outbreaks. Overall, the prevalent factors related to 2021–2022 influenza outbreaks included epidemic timing, Tv, Ts, Tv/Ts, P137 (B → P), P148 (B → P), P199 (P → A), P212 (P → A), P214 (H → P) and P563 (B → P). The preference of amino acid mutations for charge/pH could influence the epidemic/outbreak trends of infectious diseases. Here was a good model of the evolution of infectious disease pathogens. This study, on account of further exploration of virology, genetics, bioinformatics and outbreak information, might facilitate further understanding of their deep interaction mechanisms in the spread of infectious diseases.
Journal Article
Telomere‐to‐telomere genome assembly reveals insights into the adaptive evolution of herbivore‐defense mediated by volatile terpenoids in Oenanthe javanica
Summary Releasing large quantities of volatiles is a defense strategy used by plants to resist herbivore attack. Oenanthe javanica, a perennial herb of the Apiaceae family, has a distinctive aroma due to volatile terpenoid accumulation. At present, the complete genome and genetic characteristics of volatile terpenoids in O. javanica remain largely unclear. Here, the telomere‐to‐telomere genome of O. javanica, with a size of 1012.13 Mb and a contig N50 of 49.55 Mb, was established by combining multiple sequencing technologies. Comparative genome analysis revealed that O. javanica experienced a recent species‐specific whole‐genome duplication event during the evolutionary process. Numerous gene family expansions were significantly enriched in the terpenoid biosynthesis process, monoterpenoid, and diterpenoid biosynthesis pathways, which resulted in abundant volatile substance accumulation in O. javanica. The volatile terpenoids of O. javanica showed repellent effects on herbivores. Terpenoid biosynthesis was activated by wounding signals under exogenous stimuli. The TPS gene family was significantly expanded in O. javanica compared to those in other species, and the members (OjTPS1, OjTPS3, OjTPS4, OjTPS5, OjTPS7, OjTPS16, OjTPS18, OjTPS30 and OjTPS58) responsible for different terpenoid biosynthesis were functionally characterized. These results reveal the genome evolution and molecular characteristics of volatile terpenoids in the process of plant–herbivore interactions. This study also provides genomic resources for genetic and molecular biology research on O. javanica and other plants.
Journal Article
Redesign of (R)-Omega-Transaminase and Its Application for Synthesizing Amino Acids with Bulky Side Chain
ω-Transaminase (ω-TA) is an attractive biocatalyst for stereospecific preparation of amino acids and derivatives, but low catalytic efficiency and unfavorable substrate specificity hamper their industrial application. In this work, to obtain applicable (R)-ω-TA responsible for amination of α-keto acids substrates, the reactivities of eight previously synthesized ω-TAs toward pyruvate using (R)-α-methylbenzylamine ((R)-α-MBA) as amine donor were investigated, and Gibberella zeae TA (GzTA) with the highest (R)-TA activity and stereoselectivity was selected as starting scaffold for engineering. Site-directed mutagenesis around enzymatic active pocket and access tunnel identified three positive mutation sites, S214A, F113L, and V60A. Kinetic analysis synchronously with molecular docking revealed that these mutations afforded desirable alleviation of steric hindrance for pyruvate and α-MBA. Furthermore, the constructed single-, double-, and triple-mutant exhibited varying degrees of improved specificities toward bulkier α-keto acids. Using 2-oxo-2-phenylacetic acid (1d) as substrate, the conversion rate of triple-mutant F113L/V60A/S214A increased by 3.8-fold relative to that of wide-type GzTA. This study provided a practical engineering strategy for improving catalytic efficiency and substrate specificity of (R)-ω-TA. The obtained experience shed light on creating more industrial ω-TAs mutants that can accommodate structurally diverse substrates.
Journal Article
Charged amino acid variability related to N-glyco -sylation and epitopes in A/H3N2 influenza: Hem -agglutinin and neuraminidase
The A/H3N2 influenza viruses circulated in humans have been shown to undergo antigenic drift, a process in which amino acid mutations result from nucleotide substitutions. There are few reports regarding the charged amino acid mutations. The purpose of this paper is to explore the relations between charged amino acids, N-glycosylation and epitopes in hemagglutinin (HA) and neuraminidase (NA).
A total of 700 HA genes (691 NA genes) of A/H3N2 viruses were chronologically analyzed for the mutational variants in amino acid features, N-glycosylation sites and epitopes since its emergence in 1968.
It was found that both the number of HA N-glycosylation sites and the electric charge of HA increased gradually up to 2016. The charges of HA and HA1 increased respectively 1.54-fold (+7.0 /+17.8) and 1.08-fold (+8.0/+16.6) and the number of NGS in nearly doubled (7/12). As great diversities occurred in 1990s, involving Epitope A, B and D mutations, the charged amino acids in Epitopes A, B, C and D in HA1 mutated at a high frequency in global circulating strains last decade. The charged amino acid mutations in Epitopes A (T135K) has shown high mutability in strains near years, resulting in a decrease of NGT135-135. Both K158N and K160T not only involved mutations charged in epitope B, but also caused a gain of NYT158-160. Epitope B and its adjacent N-glycosylation site NYT158-160 mutated more frequently, which might be under greater immune pressure than the rest.
The charged amino acid mutations in A/H3N2 Influenza play a significant role in virus evolution, which might cause an important public health issue. Variability related to both the epitopes (A and B) and N-glycosylation is beneficial for understanding the evolutionary mechanisms, disease pathogenesis and vaccine research.
Journal Article
Dose-response relationship between lower serum magnesium level and higher prevalence of knee chondrocalcinosis
Background
The aim was to assess serum magnesium levels in relation to prevalence of knee chondrocalcinosis in two population-based Chinese studies.
Methods
Data included in this analysis consisted of two population-based cross-sectional studies, i.e., the Xiangya Hospital Health Management Center Study and the Xiangya Osteoarthritis (XO) Study I. A bilateral knee anteroposterior radiograph was obtained from each subject. Radiographic knee chondrocalcinosis was present if there was definite linear cartilage calcification. Serum magnesium concentration was measured using the chemiluminescence method. We examined the relation of serum magnesium levels to prevalence of knee chondrocalcinosis using generalized estimating equations.
Results
The prevalence of knee chondrocalcinosis was 1.4% in the Xiangya Hospital Health Management Center Study (n = 12,631). Compared with the lowest tertile, the age, sex and body mass index (BMI)-adjusted odds ratios (ORs) of chondrocalcinosis were 0.59 (95% CI 0.40–0.87) and 0.49 (95% CI 0.33–0.72) in the second and the third tertiles of serum magnesium, respectively (
P
for trend <0.001). The prevalence of knee chondrocalcinosis in the XO Study I (n = 1316) was 4.1%. The age, sex and BMI-adjusted ORs of chondrocalcinosis were 0.67 (95% CI 0.34–1.30) in the second and 0.45 (95% CI 0.21–0.94) in the third tertile of serum magnesium when compared with the lowest tertile (
P
for trend = 0.030). Similar results were observed in men and women in both studies. Adjusting for additional potential confounders did not change the results materially.
Conclusions
Subjects with lower levels of serum magnesium, even within the normal range, had higher prevalence of knee chondrocalcinosis in a dose-response relationship manner, suggesting that magnesium may have a preventive or therapeutic potential for knee chondrocalcinosis.
Journal Article
Effect of Slow-Release Urea on Yield and Quality of Euryale ferox
Slow-release urea, as an environmentally friendly fertiliser, can provide a continuous and uniform supply of nutrients needed by the crop, reduce the amount and frequency of fertiliser application, and promote the uptake and utilisation of nitrogen in crops. The production of E. ferox is often dominated by the application of quick-acting fertilisers, resulting in serious problems of over-fertilisation, inappropriate periods of fertilisation, eutrophication of soil and water due to fertilisation, and difficulties in applying fertilisers. Therefore, in this study, different amounts (CK, T1, T2, T3, T4, T5) of SRU (Slow-release Urea) were first applied, and T3 (18.8 kg·667 m−2) was found to significantly improve both yield and quality. Further, it was found that under different SRU (CK, S1, S2, S3, S4) application period treatments, application of 18.8 kg·667 m−2 at AFP20 (S2) period significantly increased the yield and quality of E. ferox. In the seed kernels of E. ferox, the total yield, soluble sugar content, total starch, and flavonoid content increased significantly by 10.35%, 36.40%, 5.91%, and 22.80%, respectively, compared with CK. In addition, the expression of key sugar transporter genes (EfSWEETs), flavonoid synthesis-related genes (EfPAL, EfDFR, etc.), and starch synthesis-related enzyme activities (SBE, SSS, GBSS) were significantly increased. By exploring the quantity of application and application period of SRU, this study was carried out to investigate the in-depth effect of SRU on the growth and development of E. ferox and to provide technical references for the increase in E. ferox yield, the improvement in E. ferox quality, and the simplification of fertiliser application.
Journal Article