Displaying publications 21 - 40 of 265 in total

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  1. Gao X, Yanan J, Santhanam RK, Wang Y, Lu Y, Zhang M, et al.
    J Food Sci, 2021 Feb;86(2):366-375.
    PMID: 33448034 DOI: 10.1111/1750-3841.15599
    Liver damage is a common liver disorder, which could induce liver cancer. Oral antioxidant is one of the effective treatments to prevent and alleviate liver damage. In this study, three flavonoids namely myricetin, isoquercitrin, and isorhamnetin were isolated and identified from Laba garlic. The isolated compounds were investigated on the protective effects against H2 O2 -induced oxidative damages in hepatic L02 cells and apoptosis inducing mechanism in hepatic cancer cells HepG2 by using MTT assay, flow cytometry and western blotting analysis. Myricetin, isoquercitrin, and isorhamnetin showed proliferation inhibition on HepG2 cells with IC50 value of 44.32 ± 0.213 µM, 49.68 ± 0.192 µM, and 54.32 ± 0.176 µM, respectively. While they showed low toxicity on normal cell lines L02. They could significantly alleviate the oxidative damage towards L02 cells (P < 0.05), via inhibiting the morphological changes in mitochondria and upholding the integrity of mitochondrial structure and function. The fluorescence intensity of L02 cells pre-treated with myricetin, isoquercitrin, and isorhamnetin (100 µM) was 89.23 ± 1.26%, 89.35 ± 1.43% and 88.97 ± 0.79%, respectively. Moreover, the flavonoids could induce apoptosis in HepG2 cells via Bcl-2/Caspase pathways, where it could up-regulate the expression of Bax and down-regulate the expression of Bcl-2, Bcl-xL, pro-Caspase-3, and pro-Caspase-9 proteins in a dose dependent manner. Overall, the results suggested that the flavonoids from Laba garlic might be a promising candidate for the treatment of various liver disorders. PRACTICAL APPLICATION: Flavonoids from Laba garlic showed selective toxicity towards HepG2 cells in comparison to L02 cells via regulating Bcl-2/caspase pathway. Additionally, the isolated flavonoids expressively barred the oxidative damage induced by H2 O2 in L02 cells. These results suggested that the flavonoids from laba garlic could be a promising agent towards the development of functional foods.
  2. Chen H, Zeng X, Zhou Y, Yang X, Lam SS, Wang D
    J Hazard Mater, 2020 07 15;394:122570.
    PMID: 32244145 DOI: 10.1016/j.jhazmat.2020.122570
    The removal of antibiotics and resistance genes in wastewater treatment plants has attracted widespread attention, but the potential role of residual antibiotics in the disposal of waste activated sludge (WAS) has not been clearly understood. In this study, the effect of roxithromycin (ROX) on volatile fatty acid (VFA) recovery from WAS anaerobic fermentation was investigated. The experimental results showed that ROX made a positive contribution to the production of VFAs. With the increase of ROX dosages from 0 to 100 mg/kg TSS, the maximum accumulation of VFAs increased from 295 to 610 mg COD/L. Mechanism studies revealed that ROX promoted the solubilization of WAS by facilitating the disruption of extracellular polymeric substances. In addition, ROX enhanced the activity of acetate kinase and inhibited the activities of α-glucosidase and coenzyme F420, and showed a stronger inhibitory effect on methane production than the hydrolysis process, thus resulting in an increase in VFA accumulation. These findings provide a new insight for the role of antibiotics in anaerobic fermentation of WAS.
  3. Qin Y, Huang X, Chen H, Liu X, Li Y, Hou J, et al.
    BMC Infect Dis, 2020 Jul 29;20(1):551.
    PMID: 32727383 DOI: 10.1186/s12879-020-05260-8
    BACKGROUND: Talaromyces marneffei (TM) is a dimorphic fungus mainly prevalent in Southeast Asian countries, which often causes disseminated life-threatening infection. TM infection often occurs in HIV/AIDS patients even in the antiretroviral therapy (ART) era. However, there has as yet, not been a systematic analysis of the prevalence of TM infection in HIV-infected populations in Asia.

    METHODS: In this study, we searched Pubmed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and WanFang from inception to 21 November 2018 for studies reporting TM infection in people living with HIV/AIDS (PLWHA). Our meta-analysis included studies investigating the prevalence of TM infection in PLWHA. Reviews, duplicate studies, and animal studies were excluded. A random effects model was used to estimate pooled prevalence, and meta-regression analysis was conducted to explore potential factors for heterogeneity.

    RESULTS: 159,064 patients with HIV infection in 33 eligible studies were included in our meta-analysis. The pooled prevalence of TM infection in PLWHA was 3.6%. Vietnam had the highest prevalence (6.4%), followed by Thailand (3.9%), China (3.3%), India (3.2%) and Malaysia (2.1%). In China, TM infection was most prevalent in South China (15.0%), while the burden in Southwest China was not very heavy (0.3%). CD4+ T-cell counts below 200 cells/mm3 contributed to the increased risk of TM infection in PLWHA (OR 12.68, 95%CI: 9.58-16.77). However, access to ART did not significantly decrease the risk of TM infection in PLWHA.

    CONCLUSIONS: The burden of TM infection in Asia is heavy, and varies from region to region. PLWHA in lower latitude areas are more likely to suffer from TM infection. Optimization of diagnostic tools and universal screening for TM in vulnerable people to ensure early case detection and prompt antifungal treatment should be considered.

  4. Gao X, Xue Z, Ma Q, Guo Q, Xing L, Santhanam RK, et al.
    J Food Biochem, 2020 02;44(2):e13126.
    PMID: 31877235 DOI: 10.1111/jfbc.13126
    Garlic protein (GP) was enzymatically hydrolyzed using pepsin and trypsin followed by the evaluation of antioxidant and angiotensin-converting enzyme (ACE) inhibitory activities of GP and its hydrolysates. The antihypertensive effects of GP and its hydrolysates were determined in vivo. The results showed that GP and its hydrolysates namely GPH-P (pepsin) and GPH-T (trypsin) possessed appreciable antioxidant and ACE inhibitory activities. The ACE inhibitory activity of GP, GPH-T, and GPH-P was in consistent with their antioxidant activities. GP and its hydrolysates offered significant protective effects against H2 O2 -induced oxidative damage (p 
  5. Ude CC, Chen HC, Norhamdan MY, Azizi BM, Aminuddin BS, Ruszymah BHI
    Cell Tissue Bank, 2017 Sep;18(3):355-367.
    PMID: 28667462 DOI: 10.1007/s10561-017-9638-1
    In our quest to standardize our formula for a clinical trial, transforming growth factor-beta3 (TGF-β3) alone and in combination with bone morphogenetic protein-6 (BMP-6) were evaluated for their effectiveness in cartilage differentiation. Bone Marrow Stem Cells (BMSCs) and Adipose Derived Stem Cells (ADSCs) were induced to chondrogenic lineage using two different media. Native chondrocytes served as positive control. ADSCs and BMSCs proved multipotency by tri-lineage differentiations. ADSC has significantly higher growth kinetics compare to Chondrocyte only p ≤ 0.05. Using TGF-β3 alone, BMSC revealed higher expressions for hyaline cartilage genes compare to ADSCs. Chondrocyte has significantly higher early chondrogenic markers expression to ADSCs and BMSCs, while BMSCs was only higher to ADSC at chondroadherin, p ≤ 0.0001. On mature chondrogenic markers, chondrocytes were significantly higher to ADSCs and BMSCs for aggrecan, collagen IX, sry (sex determining region y)-box9, collagen II and fibromodullin; and only to ADSC for collagen XI. BMSC was higher to ADSC for aggrecan and collagen IX, p ≤ 0.0001. The combination of TGF-β3 + BMP-6 revealed increased gene expressions on both BMSCs and ADSCs for early and mature chondrogenic markers, but no significance difference. For dedifferentiation markers, ADSC was significantly higher to chondrocyte for collagen I. Glycosaminoglycan evaluations with both formulas revealed that chondrocytes were significantly higher to ADSCs and BMSCs, but none was significant to each other, p ≤ 0.0001. Combination of 10 ng TGF-β3 with 10 ng of BMP-6 enhanced chondrogenic potentials of BMSCs and ADSCs compare to TGF-β3 alone. This could be the ideal cocktail for either cell's chondrogenic induction.
  6. Ng C, Chen H, Goh SG, Haller L, Wu Z, Charles FR, et al.
    Mar Pollut Bull, 2018 Oct;135:475-480.
    PMID: 30301062 DOI: 10.1016/j.marpolbul.2018.07.055
    Poor microbial water quality jeopardizes the health and safety of food produced by aquaculture farms. Three fish farms and transect sites in Singapore were assessed for microbial water quality and antimicrobial resistance determinants. Of the 33 multidrug resistant E. coli isolated from surface waters of the Johor Straits, 81.8% were ESBL producers. The relative abundance of sul1, qnrA and intI1 genes were higher in sediments than surface waters. Among the surface water samples, higher concentrations (10-1-101) of beta-lactamases (blaSHV, blaOXA, blaCTX-M) were detected in the transect sites. This study highlights a potential antimicrobial resistance transmission chain from environmental waters, to animal carriers and humans.
  7. Gao X, Santhanam RK, Xue Z, Jia Y, Wang Y, Lu Y, et al.
    J Food Sci, 2020 Apr;85(4):1060-1069.
    PMID: 32147838 DOI: 10.1111/1750-3841.15084
    Inonotus obliquus is a traditional mushroom well known for its therapeutic value. In this study, various solvent fractions of I. obliquus were preliminarily screened for their antioxidant, α-amylase and α-glucosidase inhibition properties. To improve the drug delivery, the active fraction (ethyl acetate fraction) of I. obliquus was synthesized into fungisome (ethyl acetate phophotidyl choline complex, EAPC) and its physical parameters were assessed using Fourier transform infrared spectroscopy (FTIR), High performance liquid chromatography (HPLC), Scanning electron microscope (SEM), and ς potential analysis. Then normal human hepatic L02 cells was used to evaluate the cytotoxicity of EAPC. The results showed that EA fraction possesses significant free radical scavenging, α-amylase and α-glucosidase inhibition properties. FTIR, SEM, and HPLC analysis confirmed the fungisome formation. The particle size of EAPC was 102.80 ± 0.42 nm and the ς potential was -54.30 ± 0.61 mV. The percentage of drug entrapment efficiency was 97.13% and the drug release rates of EAPC in simulated gastric fluid and simulated intestinal fluid were 75.04 ± 0.29% and 93.03 ± 0.36%, respectively. EAPC was nontoxic to L02 cells, however it could selectively fight against the H2 O2 induced oxidative damage in L02 cells. This is the first study to provide scientific information to utilize the active fraction of I. obliquus as fungisome. PRACTICAL APPLICATIONS: Inonotus obliquus (IO) is a traditional medicinal fungus. The extracts of IO have obvious antioxidant and hypoglycemic activities. Ethyl acetate (EA) fraction of IO was encapsulated in liposomes to form EAPC. EAPC has a sustained-release effect. It has nontoxic to L02 cells and could protect L02 cells from oxidative damage caused by hydrogen peroxide. This study could provide new ideas for the treatment of diabetes.
  8. He G, Sun Z, Zhao Y, Zhang S, Chen H, Zhao Z, et al.
    Int J Clin Exp Pathol, 2020;13(5):1060-1065.
    PMID: 32509079
    In recent years, the incidence and mortality of infectious diseases in China are increasing. Infectious diseases, especially new infectious diseases, seriously threaten people's lives. Recent works found that most of the emerging infectious diseases come from wild life. At the same time, the impact of human activities on the environment has further deteriorated the living environment of wildlife. However, with the conducted in-depth research on virus, human beings increase the risk of getting infected. Taking Beta Coronavirus as the example, we analyzed the transmission risks of coronavirus in the prevention and control of the outbreaks of emerging infectious diseases, and recommend the prevention and control strategies before, during and after the viral outbreak. Additional works are urgently needed to better define the biological and epidemiological characteristics of these viruses.
  9. Wang Q, Wang J, Li N, Liu J, Zhou J, Zhuang P, et al.
    Molecules, 2022 Jan 10;27(2).
    PMID: 35056765 DOI: 10.3390/molecules27020444
    (1) Background: Orthosiphon stamineus Benth. is a traditional medicine used in the treatment of diabetes and chronic renal failure in southern China, Malaysia, and Thailand. Diabetes is a chronic metabolic disease and the number of diabetic patients in the world is increasing. This review aimed to systematically review the effects of O. stamineus in the treatment of diabetes and its complications and the pharmacodynamic material basis. (2) Methods: This systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the databases ScienceDirect, PubMed, and Web of Science. (3) Results: Thirty-one articles related to O. stamineus and diabetes were included. The mechanisms of O. stamineus in the treatment of diabetes and its complications mainly included inhibiting α-amylase and α-glucosidase activities, antioxidant and anti-inflammatory activities, regulating lipid metabolism, promoting insulin secretion, ameliorating insulin resistance, increasing glucose uptake, promoting glycolysis, inhibiting gluconeogenesis, promoting glucagon-likepeptide-1 (GLP-1) secretion and antiglycation activity. Phenolic acids, flavonoids and triterpenoids might be the main components for hypoglycemia effects in O. stamineus. (4) Conclusion: O. stamineus could be an antidiabetic agent to treat diabetes and its complications. However, it needs further study on a pharmacodynamic substance basis and the mechanisms of effective constituents.
  10. Sanjaya EH, Chen Y, Guo Y, Wu J, Chen H, Din MFM, et al.
    Bioresour Technol, 2022 Feb;346:126622.
    PMID: 34958906 DOI: 10.1016/j.biortech.2021.126622
    The simultaneous partial nitritation, anammox, denitrification, and COD oxidation (SNADCO) method was successfully carried out in an air-lift moving bed biofilm reactor (AL-MBBR) with cylinders carriers for the treatment of digested fish processing wastewater (FPW). Synthetic wastewater was used as substrate at stage 1. It changed into the digested FPW with dilution variation in order to increase the nitrogen and COD loading rates. With influent concentration of NH4+-N of 909 ± 101 mg-N/L and COD of 731 ± 26 mg/L, the nitrogen removal efficiency was 86.8% (nitrogen loading rate of 1.21 g-TN/L/d) and the COD removal efficiency was 50.5% (COD loading rate at 0.98 g-COD/L/d). This study showed that the process has the advantages in treating the real high ammonia concentration of digested wastewater containing organic compounds. The nitritation and anammox route was predominant in nitrogen removal, while COD oxidation and microbe proliferation played the main role in COD removal.
  11. Gou Z, Zheng H, He Z, Su Y, Chen S, Chen H, et al.
    Environ Pollut, 2023 Jan 15;317:120790.
    PMID: 36460190 DOI: 10.1016/j.envpol.2022.120790
    This study aims to investigate the positive effects of the combined use of Enterobacter cloacae and biochar on improving nitrogen (N) utilization. The greenhouse pots experimental results showed the synergy of biochar and E. cloacae increased soil total N content and plant N uptake by 33.54% and 15.1%, respectively. Soil nitrogenase (NIT) activity increased by 253.02%. Ammonia monooxygenase (AMO) and nitrate reductase (NR) activity associated with nitrification and denitrification decreased by 10.94% and 29.09%, respectively. The relative abundance of N fixing microorganisms like Burkholderia and Bradyrhizobium significantly increased. Sphingomonas and Ottowia, two bacteria involved in the nitrification and denitrification processes, were found to be in lower numbers. The E. cloacae's ability to fix N2 and promote the growth of plants allow the retention of N in soil and make more N available for plant development. Biochar served as a reservoir of N for plants by adsorbing N from the soil and providing a shelter for E. cloacae. Thus, biochar and E. cloacae form a synergy for the management of agricultural N and the mitigation of negative impacts of pollution caused by excessive use of N fertilizer.
  12. Gao D, Chen H, Li H, Yang X, Guo X, Zhang Y, et al.
    Front Nutr, 2023;10:1149137.
    PMID: 37025610 DOI: 10.3389/fnut.2023.1149137
    INTRODUCTION: Arctium lappa L. root has high nutritional and medicinal values and has been identified as a healthy food raw material by the Ministry of Health of the People's Republic of China.

    METHODS: In the present study, an aqueous two-phase system (ATPS) of polyethylene glycol (PEG)-(NH4)2SO4 was used to extract Arctium lappa L. polysaccharides (ALPs) from the Arctium lappa L. roots, the optimal extraction conditions of crude ALPs were optimized by using the single-factor experiment and response surface methodology. The structure and composition of ALPs were determined by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and high-performance liquid chromatography (HPLC). At the same time, the antioxidant activity of ALPs was investigated by in vitro antioxidant experiment.

    RESULTS: The optimized extraction parameters for extraction ALPs were as follows: the PEG relative molecular weight of 6,000, a quality fraction of PEG 25%, a quality fraction of (NH4)2SO4 18%, and an extraction temperature of 80°C. Under these conditions, the extraction rate of ALPs could reach 28.83%. FTIR, SEM and HPLC results showed that ALPs were typical acidic heteropolysaccharides and had uneven particle size distribution, an irregular shape, and a rough surface. The ALPs were chiefly composed of glucose, rhamnose, arabinose, and galactose with a molar ratio of 70.19:10.95:11.16:6.90. In addition, the ALPs had intense antioxidant activity in vitro with IC50 values in the ·OH radical (1.732 mg/ml), DPPH radical (0.29 mg/ml), and superoxide anion (0.15 mg/ml) scavenging abilities.

    DISCUSSION: The results showed that ATPS was an efficient method to extract polysaccharides and could be used for the extraction of other polysaccharides. These results indicated that ALPs had great prospects as a functional food and could be exploited in multiple fields.

  13. Chen H, Wang Z, Wu D, Jia H, Wen C, Rao H, et al.
    Math Biosci Eng, 2023 Jun 09;20(7):13267-13317.
    PMID: 37501488 DOI: 10.3934/mbe.2023592
    This paper presents an improved beluga whale optimization (IBWO) algorithm, which is mainly used to solve global optimization problems and engineering problems. This improvement is proposed to solve the imbalance between exploration and exploitation and to solve the problem of insufficient convergence accuracy and speed of beluga whale optimization (BWO). In IBWO, we use a new group action strategy (GAS), which replaces the exploration phase in BWO. It was inspired by the group hunting behavior of beluga whales in nature. The GAS keeps individual belugas whales together, allowing them to hide together from the threat posed by their natural enemy, the tiger shark. It also enables the exchange of location information between individual belugas whales to enhance the balance between local and global lookups. On this basis, the dynamic pinhole imaging strategy (DPIS) and quadratic interpolation strategy (QIS) are added to improve the global optimization ability and search rate of IBWO and maintain diversity. In a comparison experiment, the performance of the optimization algorithm (IBWO) was tested by using CEC2017 and CEC2020 benchmark functions of different dimensions. Performance was analyzed by observing experimental data, convergence curves, and box graphs, and the results were tested using the Wilcoxon rank sum test. The results show that IBWO has good optimization performance and robustness. Finally, the applicability of IBWO to practical engineering problems is verified by five engineering problems.
  14. Luo J, Liu X, Li T, Chen H, Qu T, Wang Y, et al.
    Mitochondrial DNA B Resour, 2024;9(1):186-190.
    PMID: 38282979 DOI: 10.1080/23802359.2024.2306203
    Duhaldea cappa, a valuable medicinal plant of genus Duhaldea in the tribe Inuleae, is predominantly found in China, Bhutan, India, Malaysia, Nepal, Pakistan, Thailand, and Vietnam. However, the genomic studies of Duhaldea cappa are limited. In this study, we successfully sequenced and assembled the complete chloroplast genome of Duhaldea cappa. The chloroplast genome is 150,819 bp in length with a 37.73% GC content. The chloroplast genome has a quadripartite structure, consisting of a large single-copy region of 82,731 bp, a small single-copy region of 18,168 bp, and a pair of inverted repeat sequences of 24,960 bp. The genome contains 133 genes. Among these genes, there are 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogeny reconstructed from data of the complete chloroplast genome indicated that Duhaldea cappa is closely related to Pluchea indica in the tribe Inuleae. Analyzing and reporting the chloroplast genome of Duhaldea cappa will establish a solid theoretical and data foundation for the efficient development, conservation, and utilization of this plant species.
  15. Zhao S, Chen J, Cao S, Wang H, Chen H, Wei Y, et al.
    Plant Physiol Biochem, 2024 Feb 29;208:108480.
    PMID: 38437751 DOI: 10.1016/j.plaphy.2024.108480
    It is well established that programmed cell death (PCD) occurred in broccoli during postharvest senescence, but no studies have been conducted on the regulation of broccoli cytochrome f by mannose treatment and its relationship with PCD. In this study, we treated broccoli buds with mannose to investigate the changes in color, total chlorophyll content, gene expression related to chlorophyll metabolism, chloroplast structure, and cytochrome f determination during postharvest storage. In addition, to investigate the effect of cytochrome f on PCD, we extracted cytochrome f from broccoli and treated Nicotiana tabacum L. cv Bright Yellow 2 (BY-2) cells with extracted cytochrome f from broccoli at various concentrations. The results showed that cytochrome f can induce PCD in tobacco BY-2 cells, as evidenced by altered cell morphology, nuclear chromatin disintegration, DNA degradation, decreased cell viability, and increased caspase-3-like protease production. Taken together, our study indicated that mannose could effectively delay senescence of postharvest broccoli by inhibiting the expression of gene encoding cytochrome f which could induce PCD.
  16. Gou Z, Ma NL, Zhang W, Lei Z, Su Y, Sun C, et al.
    Environ Res, 2020 09;188:109829.
    PMID: 32798948 DOI: 10.1016/j.envres.2020.109829
    Intensive studies have been performed on the improvement of bioethanol production by transformation of lignocellulose biomass. In this study, the digestibility of corn stover was dramatically improved by using laccase immobilized on Cu2+ modified recyclable magnetite nanoparticles, Fe3O4-NH2. After digestion, the laccase was efficiently separated from slurry. The degradation rate of lignin reached 40.76%, and the subsequent cellulose conversion rate 38.37% for 72 h at 35 °C with cellulase at 50 U g-1 of corn stover. Compared to those of free and inactivated mode, the immobilized laccase pre-treatment increased subsequent cellulose conversion rates by 23.98% and 23.34%, respectively. Moreover, the reusability of immobilized laccase activity remained 50% after 6 cycles. The storage and thermal stability of the fixed laccase enhanced by 70% and 24.1% compared to those of free laccase at 65 °C, pH 4.5, respectively. At pH 10.5, it exhibited 16.3% more activities than its free mode at 35 °C. Our study provides a new avenue for improving the production of bioethanol with immobilized laccase for delignification using corn stover as the starting material.
  17. Lin Y, Lin Z, He F, Chen H, Lin X, Zimet GD, et al.
    Vaccine, 2020 03 23;38(14):3021-3030.
    PMID: 32127227 DOI: 10.1016/j.vaccine.2020.02.042
    OBJECTIVE: This study aims to investigate acceptance and willingness to pay for HPV vaccination among adult women in China.

    METHODS: An online survey was sent to mothers aged 27-45 years of primary school pupils in the Fujian province, China. Participants completed questions about HPV related knowledge and health beliefs, intention to take the HPV vaccine and the willingness to pay for bivalent vaccine (2vHPV), quadrivalent vaccine (4vHPV), and 9-valent HPV vaccine (9vHPV).

    RESULTS: Of a total of 2339 complete responses, 58.3% reported intent to obtain HPV vaccine. Mothers who were younger in age, residing in urban, working in managerial or professional occupations, who knew someone with cervical cancer and who were able to make independent decisions about the HPV vaccine (vs. joint decision with spouse) were more likely to express intent to have HPV vaccination. Perceived barriers, cues to action and self-efficacy were three of the constructs in the health belief model that significantly influenced HPV vaccination intent. A higher proportion of participants expressed willingness to pay for 2vHPV (81.2%) and 4vHPV (75.9%), as compared to 9vHPV (67.7%).

    CONCLUSION: Adults women expressed moderate intention to receive the HPV vaccine. Intervention to address barriers to uptake of the HPV vaccine among adult women in China is warranted.

  18. Zhu X, Chen H, Li S, Wang LC, Wu DR, Wang XM, et al.
    Front Microbiol, 2020;11:778.
    PMID: 32457710 DOI: 10.3389/fmicb.2020.00778
    Melioidosis is a common infectious disease in Southeast Asia and Northern Australia. In Hainan, several cases have been reported, but no systematic study has yet been done on the molecular epidemiology profiles of the organism. An investigation of the molecular epidemiology links and population structure of Burkholderia pseudomallei would help to better understand the clonally of the isolates and differences among them. In this study, multilocus variable-number tandem repeat analysis (MLVA), and multilocus sequence typing (MLST) were applied to examine the epidemiological relatedness and population structure of 166 B. pseudomallei isolates obtained during 2002-2014 in Hainan, China. Both the MLVA_4 and MLST approaches had high discriminatory power for this population, with diversity indices of 0.9899 and 0.9457, respectively. However, the MLVA_4 assay showed a higher discriminatory power than the MLST approach, and a variable-number tandem repeat (VNTR3 933) found by the MLVA approach was the most useful in discriminating strains from this province. A total of 166 strains yielded 99 MLVA_4 genotypes, of which 34 genotypes were shared by 101 isolates, for a clustering rate of 60.8% (101/166), which suggested that some cases may have a common source. Additionally, 65 isolates showed distinct genotypes, indicating that more than 39.2% (65/166) of melioidosis cases in Hainan had epidemiologically unrelated or sporadic characteristics. The 166 isolates were resolved into 48 STs, of which five STs (ST55, -70, -46, -50, and -58) were here found to be predominant. Phylogenetic analysis of 116 isolates conducted using the eBURST v3 segregated the 48 STs into eight groups with ST50 as predicted founder, and 21 STs were found to be singletons, which suggest that the strains in the Hainan region represent a high diversity of ST clones, indicating that many B. pseudomallei clone groups are endemic to this region. Moreover, ST50 had 5 SLV, 7 DLV, 6 TLV, and 29 satellite STs and formed a radial expansion pattern, suggesting that the melioidosis epidemic in this study was mainly caused by the clonal expansion of ST 50. Phylogenetic analysis on global scale suggests that China's isolates are closely related to isolates from Southeast Asia, particularly from Thailand and Malaysia.
  19. Feng X, Guo N, Chen H, Wang H, Yue L, Chen X, et al.
    Dalton Trans, 2017 Oct 24;46(41):14192-14200.
    PMID: 28990615 DOI: 10.1039/c7dt02974h
    A series of coordination polymers {[Ln(aobtc)(H2O)4]·Hbipy·H2O}n (H4aobtc = azoxybenzene-2,2',3,3'-tetracarboxylic acid, bipy = 4,4'-bipyridine, and Ln = Sm(1), Eu(2), Gd(3), Tb(4), Dy(5), Er(6)) have been synthesized and characterized systematically. The cationic Hbipy(+) guest incorporated polymers are isostructural sets, featuring a one-dimensional (1D) zigzag double chain edifice composed of binuclear clusters [Ln2(H4aobtc)2], with the Hbipy(+) guest being located on two sides. These 1D chains are further interlinked into a 2D layer structure, and further extended into a 3D framework through hydrogen bonding interactions. The luminescence emission spectra of polymers 2 and 3 are based on the H4aobtc acid ligands, while 1 and 4 display the characteristic f-f transitions of Ln(iii) ions. Magnetic measurements revealed the presence of ferromagnetic behavior in polymer 3. The magnetic behaviors of 4 and 6 are ascribed to the depopulation of the Stark levels and/or weak antiferromagnetic interactions within MOFs at lower temperature. Slow relaxation is observed through the alternating-current susceptibility measurements for 5 at lower temperature, and the coexistence of weak ferromagnetism corresponding to the spin-canting-like behavior.
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