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1.
Int J Biol Macromol ; 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32068055

RESUMO

Humic acid (HA) is well-known for its chelating activity towards various contaminants, but it dissolves in water thus cannot be used alone as an adsorbent. By immobilizing HA to the surface of nano-hydroxyapatite (nHAP), a novel HA-nHAP adsorbent was prepared. The composition and surface morphology of the obtained HA-nHAP composite were studied in detail. Adsorptive removal of Cu(II) and Methylene blue (MB) using HA-nHAP in single and binary systems were investigated. Results indicated that HA-nHAP exhibited efficient removal of Cu(II) and MB with a favorable adsorption at higher pH. The mechanisms involved in adsorption of Cu(II) and MB were electrostatic interaction and surface complexation. Optimization study using central composite design (CCD) based response surface methodology (RSM) was performed and 3-D response surfaces were plotted from the mathematical model. The optimum conditions were found to be 2.2 g/L (adsorbent dosage), 8 h (contact time), 25 mg/L (initial Cu(II) concentration), and 85 mg/L (initial MB concentration). At optimum conditions, removal rates of Cu(II) and MB were 97.68% and 100%, respectively. The adsorption kinetics and equilibrium fitted well with Elovich and Langmuir models, respectively. Desorption studies confirmed that HA-nHAP adsorbent could be effectively regenerated and reused.

2.
Org Biomol Chem ; 18(5): 920-930, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-31922164

RESUMO

By choosing pyridostatin (PDS) with high thermal stabilization towards mixed-type G-quadruplexes as the monomer in dimers, three novel polyether-tethered PDS dimers (1a-c) were first synthesized and their interaction with human telomere G-quadruplex dimers (G2T1) was studied. Through the regulation of the linker length in PDS dimers, the dimer with a medium-length polyether linker (1b) showed higher binding selectivity and thermal stabilization (ΔTm = 29.5 °C) towards antiparallel G2T1 over G-quadruplex monomers (G1). Furthermore, the dimer with the longest-length polyether linker (1c) showed higher binding selectivity and thermal stabilization towards mixed-type G2T1 over mixed-type G1, c-kit 1, c-kit 2, c-myc and ds DNA. This work provides new insights into the development of G2T1 binders, especially mixed-type G2T1 binders, which could be promoted by a polymer formed with a mixed-type G-quadruplex binder. In addition, dimer 1c exhibited stronger telomerase inhibition than dimers 1a and 1b.

3.
Emerg Microbes Infect ; 9(1): 20-31, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31859605

RESUMO

Porcine deltacoronavirus (PDCoV) is an emerging swine coronavirus that causes severe diarrhea, resulting in high mortality in neonatal piglets. Despite widespread outbreaks in many countries, no effective PDCoV vaccines are currently available. Here, we generated, for the first time, a full-length infectious cDNA clone of PDCoV. We further manipulated the infectious clone by replacing the NS6 gene with a green fluorescent protein (GFP) to generate rPDCoV-ΔNS6-GFP; likewise, rPDCoV-ΔNS7 was constructed by removing the ATG start codons of the NS7 gene. Growth kinetics studies suggest that rPDCoV-ΔNS7 could replicate similarly to that of the wild-type PDCoV, whereas rPDCoV-ΔNS6-GFP exhibited a substantial reduction of viral titer in vitro and in vivo. Piglets inoculated with rPDCoV-ΔNS7 or wild-type PDCoV showed similar diarrheic scores and pathological injury. In contrast, rPDCoV-ΔNS6-GFP-infected piglets did not show any clinical signs, indicating that the NS6 protein is an important virulence factor of PDCoV and that the NS6-deficient mutant virus might be a promising live-attenuated vaccine candidate. Taken together, the reverse genetics platform described here not only provides more insights into the role of PDCoV accessory proteins in viral replication and pathogenesis, but also allows the development of novel vaccines against PDCoV infection.

4.
Org Lett ; 21(15): 5838-5842, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31339734

RESUMO

The tandem synthesis of 2-trifluoromethylthio(seleno)-substituted benzofurans using palladium-catalyzed conditions is reported. Trifluoromethylthio(seleno)lation of 2-(2,2-dibromovinyl)phenols with (bpy)CuSCF3 or [(bpy)CuSeCF3]2 furnishes several 2-trifluoromethylthio(seleno)lated benzofurans in acceptable to good yield. Mechanistic investigations were performed to elucidate the reaction pathway, which was involved in the formation of a 2-bromobenzofuran species. The scope of this protocol was further extended to the preparation of 2-trifluoromethylthio(seleno)lated benzothiophenes and indoles.

5.
Arch Virol ; 164(2): 413-425, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30377826

RESUMO

Porcine deltacoronavirus (PDCoV) was first detected in Hong Kong and has recently spread to many countries around the world. PDCoV causes acute diarrhea and vomiting in pigs, resulting in significant economic losses in the global pork industry. In this study, a Chinese PDCoV strain, designated CHN-HG-2017, was isolated from feces of a suckling piglet with severe watery diarrhea on a farm located in central China. Subsequently, the virus was identified by an indirect immunofluorescence assay and electron microscopy. A nucleotide sequence alignment showed that the whole genome of CHN-HG-2017 is 97.6%-99.1% identical to other PDCoV strains. Analysis of potential recombination sites showed that CHN-HG-2017 is a possible recombinant originating from the strains CH/SXD1/2015 and Vietnam/HaNoi6/2015. Furthermore, the pathogenicity of this recombinant PDCoV strain was investigated in 5-day-old piglets by oral inoculation. The challenged piglets developed typical symptoms, such as vomiting, anorexia, diarrhea and lethargy, from 1 to 7 days post-inoculation (DPI). Viral shedding was detected in rectal swabs until 14 DPI in the challenged piglets. Interestingly, high titers of virus-neutralizing antibodies in sera were detected at 21 DPI. Tissues of small intestines from CHN-HG-2017-infected piglets at 4 DPI displayed significant macroscopic and microscopic lesions with clear viral antigen expression. Our analysis of the full genome sequence of a recombinant PDCoV and its virulence in suckling piglets might provide new insights into the pathogenesis of PDCoV and facilitate further investigation of this newly emerged pathogen.


Assuntos
Infecções por Coronavirus/veterinária , Coronavirus/isolamento & purificação , Coronavirus/patogenicidade , Doenças dos Suínos/virologia , Animais , China , Coronavirus/classificação , Coronavirus/genética , Infecções por Coronavirus/virologia , Diarreia/veterinária , Diarreia/virologia , Fezes/virologia , Genoma Viral , Genômica , Filogenia , Suínos , Vietnã , Virulência
6.
Org Biomol Chem ; 16(24): 4558-4562, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29877541

RESUMO

An efficient catalytic method for the synthesis of 2,2-difluoro-1,3-benzoxathioles(selenoles) from the reaction of o-bromophenols with trifluoromethanethiolates or selenolates is disclosed. Some of the title compounds exhibited excellent insecticidal activities.

7.
Org Lett ; 20(2): 481-484, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29308902

RESUMO

A copper-mediated difluoromethylenation of o-bromophenols with trifluoromethanethiolate is described. This one-pot protocol proceeds through an intermolecular addition of S=CF2 (resulting from the decomposition of trifluoromethanethiolate) to o-bromophenols followed by intramolecular C-S coupling to form 2,2-difluoro-1,3-benzoxathioles. This method is compatible with a broad range of substrates and enables the late-stage difluoromethylenation of several functionally dense druglike o-bromophenols.

8.
Int J Syst Evol Microbiol ; 67(11): 4851-4856, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29022549

RESUMO

A Gram-stain-negative, facultative anaerobic, yellow-pigmented, rod-shaped, non-flagellum and non-motile bacterial strain, designed C9-11T, was isolated from mangrove sediment in Zhangzhou, Fujian Province, China. Growth was observed at temperatures from 15 to 37 °C (optimum 30 °C), at salinities from 0 to 4 % (optimum 0.5-2 %) and at pH from 6 to 8 (optimum 7). Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain C9-11T was a member of the genus Altererythrobacter. Strain C9-11T was related most closely to Altererythrobacter oceanensis Y2T (96.8 % 16S rRNA gene sequence similarity), followed by Altererythrobacter marinus H32T (96.5 %). The G+C content of the genomic DNA was 63.5 mol%. The dominant fatty acids were C18 : 1ω7c (41.6 %), C17 : 1ω6c (15.4 %), 11-methyl C18 : 1ω7c (8.1 %), summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c 7.4 %) and C16 : 0 (6.2 %). The predominant respiratory quinone was ubiquinone-10 and the major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid. According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence analysis, strain C9-11Tbelongs to genus Altererythrobacter, but can readily be distinguished from recognized species. Strain C9-11T is proposed as the type strain of a novel species of the genus Altererythrobacter, for which the nameAltererythrobactermangrovi sp. nov (=MCCC 1K03311T=JCM 32056T) is proposed.


Assuntos
Alphaproteobacteria/classificação , Avicennia/microbiologia , Sedimentos Geológicos/microbiologia , Filogenia , Alphaproteobacteria/genética , Alphaproteobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
9.
Viruses ; 9(3)2017 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-28335505

RESUMO

The new porcine epidemic diarrhea (PED) has caused devastating economic losses to the swine industry worldwide. Despite extensive research on the relationship between autophagy and virus infection, the concrete role of autophagy in porcine epidemic diarrhea virus (PEDV) infection has not been reported. In this study, autophagy was demonstrated to be triggered by the effective replication of PEDV through transmission electron microscopy, confocal microscopy, and Western blot analysis. Moreover, autophagy was confirmed to benefit PEDV replication by using autophagy regulators and RNA interference. Furthermore, autophagy might be associated with the expression of inflammatory cytokines and have a positive feedback loop with the NF-κB signaling pathway during PEDV infection. This work is the first attempt to explore the complex interplay between autophagy and PEDV infection. Our findings might accelerate our understanding of the pathogenesis of PEDV infection and provide new insights into the development of effective therapeutic strategies.


Assuntos
Autofagia , Interações Hospedeiro-Patógeno , Vírus da Diarreia Epidêmica Suína/fisiologia , Replicação Viral , Animais , Western Blotting , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Células Vero
10.
Org Biomol Chem ; 14(35): 8232-6, 2016 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-27527581

RESUMO

1,3-Bis(benzimidazol-2-yl)benzene exhibits potent anionophoric activity through a process of anion exchange with a minor level of proton/anion symport. Modification of 1,3-bis(benzimidazol-2-yl)benzene with strong electron-withdrawing substituents, such as trifluoromethyl and nitro groups, leads to up to 789-fold increase in the activity. The benzimidazolyl-NH fragments, the relative position and the number of the benzimidazolyl groups on the central phenyl scaffold play an essential role in the transport.

11.
J Org Chem ; 81(17): 7993-8000, 2016 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-27477255

RESUMO

Herein, a copper-catalyzed 2,2,2-trifluoroethylthiolation reaction of aryl bromides and iodides with elemental sulfur, and 1,1,1-trifluoro-2-iodoethane is described. The reaction showed excellent functional group tolerance and allowed the synthesis of various substituted aryl 2,2,2-trifluoroethyl thioethers with good to excellent yields. This transformation constitutes a one-pot synthesis of 2,2,2-trifluoroethylthiolated compounds from inexpensive, readily available starting materials. Utility of the protocol was further demonstrated in the late-stage synthesis of the pirfenidone derivative. The copper thiolate species were prepared and proposed as key intermediates in the catalytic cycle.

12.
Accid Anal Prev ; 92: 189-201, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27085591

RESUMO

Mining has been historically considered as a naturally high-risk industry worldwide. Deaths caused by coal mine accidents are more than the sum of all other accidents in China. Statistics of 320 coal mine accidents in Shandong province show that all accidents contain indicators of "unsafe conditions of the rules and regulations" with a frequency of 1590, accounting for 74.3% of the total frequency of 2140. "Unsafe behaviors of the operator" is another important contributory factor, which mainly includes "operator error" and "venturing into dangerous places." A systems analysis approach was applied by using structural equation modeling (SEM) to examine the interactions between the contributory factors of coal mine accidents. The analysis of results leads to three conclusions. (i) "Unsafe conditions of the rules and regulations," affect the "unsafe behaviors of the operator," "unsafe conditions of the equipment," and "unsafe conditions of the environment." (ii) The three influencing factors of coal mine accidents (with the frequency of effect relation in descending order) are "lack of safety education and training," "rules and regulations of safety production responsibility," and "rules and regulations of supervision and inspection." (iii) The three influenced factors (with the frequency in descending order) of coal mine accidents are "venturing into dangerous places," "poor workplace environment," and "operator error."


Assuntos
Acidentes de Trabalho/estatística & dados numéricos , Minas de Carvão/legislação & jurisprudência , Saúde do Trabalhador/legislação & jurisprudência , China , Minas de Carvão/estatística & dados numéricos , Comportamento Perigoso , Humanos , Saúde do Trabalhador/estatística & dados numéricos , Análise de Sistemas
13.
Environ Pollut ; 213: 698-709, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27023279

RESUMO

This study was aimed at investigating the detachment of fullerene nC60 nanoparticles (NPs) in saturated sand porous media under transient and static conditions. The nC60 NPs were first attached at primary minima of Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy profiles in electrolyte solutions with different ionic strengths (ISs). The columns were then eluted with deionized water to initiate nC60 NP detachment by decreasing solution IS. Finally, the flow of the columns was periodically interrupted to investigate nC60 NP detachment under static condition. Our results show that the detachment of nC60 NPs occurred under both transient and static conditions. The detachment under transient conditions was attributed to the fact that the attractions acting on the nC60 NPs at primary minima were weakened by nanoscale physical heterogeneities and overcome by hydrodynamic drags at lower ISs. However, a fraction of nC60 NPs remained at shallow primary minima in low flow regions, and detached via Brownian diffusion during flow interruptions. Greater detachment of nC60 NPs occurred under both transient and static conditions if the NPs were initially retained in electrolyte solutions with lower valent cations due to lower attractions between the NPs and collectors. Decrease in collector surface chemical heterogeneities and addition of dissolved organic matter also increased the extent of detachment by increasing electrostatic and steric repulsions, respectively. While particle attachment in and subsequent detachment from secondary minima occur in the same electrolyte solution, our results indicate that perturbation in solution chemistry is necessary to lower the primary minimum depths to initiate spontaneous detachment from the primary minima. These findings have important implications for predicting the fate and transport of nC60 NPs in subsurface environments during multiple rainfall events and accordingly for accurately assessing their environmental risks.


Assuntos
Fulerenos/química , Difusão , Hidrodinâmica , Concentração Osmolar , Porosidade , Dióxido de Silício/química , Eletricidade Estática
14.
J Proteomics ; 130: 65-75, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26361011

RESUMO

UNLABELLED: The re-emerging porcine epidemic diarrhea virus (PEDV) variant related diarrhea has been documented in China since late 2010 and now with global distribution. Currently, a virulent PEDV CH/YNKM-8/2013 and a CV777 vaccine strain-like AH-M have been successfully isolated from the clinical samples. To dissect out the underlying pathogenic mechanism of virulent PEDV and clarify the differences between virulent and CV777 vaccine strain-like PEDV infections, we performed an iTRAQ-based comparative quantitative proteomic study of Vero cells infected with both PEDV strains. A total of 661 and 474 differentially expressed proteins were identified upon virulent and CV777 vaccine strain-like isolates infection, respectively. Ingenuity Pathway Analysis was employed to investigate the canonical pathways and functional networks involved in both PEDV infections. Comprehensive studies have revealed that the PEDV virulent strain suppressed protein synthesis of Vero cells through down-regulating mTOR as well as its downstream targets 4EBP1 and p70S6K activities, which were validated by immunoblotting. In addition, the virulent strain could activate NF-κB pathway more intensively than the CV777 vaccine strain-like isolate, and elicit stronger inflammatory cascades as well. These data might provide new insights for elucidating the specific pathogenesis of PEDV infection, and pave the way for the development of effective therapeutic strategies. BIOLOGICAL SIGNIFICANCE: Porcine epidemic diarrhea is now worldwide distributed and causing huge economic losses to swine industry. The immunomodulation and pathogenesis between PEDV and host, as well as the difference between virulent and attenuated strains of PEDV infections are still largely unknown. In this study, we presented for the first application of proteomic analysis to compare whole cellular protein alterations induced by virulent and CV777 vaccine strain-like PEDV infections, which might contribute to understand the pathogenesis of PEDV and anti-viral strategy development.


Assuntos
Vírus da Diarreia Epidêmica Suína , Proteoma/metabolismo , Proteômica/métodos , Células Vero/virologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose , Ciclo Celular , Cromatografia Líquida , Biologia Computacional , GTP Fosfo-Hidrolases/metabolismo , Inflamação , Metabolismo dos Lipídeos , Microscopia de Fluorescência , NF-kappa B/metabolismo , Filogenia , Processamento Pós-Transcricional do RNA , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Espectrometria de Massas em Tandem , Células Vero/metabolismo
15.
J Hazard Mater ; 290: 60-8, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25746565

RESUMO

This study systematically investigated influence of surface roughness and surface chemical heterogeneity on attachment and detachment of nC60 nanoparticles in saturated porous media by conducting laboratory column experiments. Sand and glass beads were employed as a model collectors to represent a different surface roughness. The two collectors were treated by washing with only deionized water or by using acids to extensively remove chemical heterogeneities. Results show that both attachment and detachment were more in the acid-treated sand than those in the acid-treated glass beads. The greater attachment and detachment were attributed to the reason that sand surfaces have much more nanoscale asperities, which facilitates particle attachment atop of them at primary minima and subsequent detachment upon reduction of ionic strength. No detachment was observed if the water-washed collectors were employed, demonstrating that the couple of chemical heterogeneity with nanoscale roughness causes irreversible attachment in primary minima. Whereas existing studies frequently represented surface rough asperities as regular geometries (e.g., hemisphere, cone, pillar) for estimating influence of surface roughness on Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energies, our theoretical calculations indicate that the assumptions could underestimate both attachment and detachment because these geometries cannot account for surface curvature effects.


Assuntos
Fulerenos/química , Nanopartículas/química , Tamanho da Partícula , Porosidade , Propriedades de Superfície
16.
J Asian Nat Prod Res ; 15(12): 1230-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24328675

RESUMO

Two new furostanol saponins ophiopogonins J (1) and K (2) were isolated from the fibrous roots of Ophiopogon japonicus. The structures of 1 and 2 were established as (25R)-26-O-[(ß-D-glucopyranosyl-(1 --> 2)-ß-D-glucopyranosyl)]-14-hydroxy-furost-5,20(22)-diene 3-O-[α-L-rhamnopyranosyl-(1 --> 2)]-ß-D-glucopyranoside (1), and (25R)-26-O-[(ß-D-glucopyranosyl-(1 --> 2)-ß-D-glucopyranosyl)]-furost-5,20(22)-diene 3-O-α-L-rhamnopyranosyl-(1 --> 2)[(ß-D-xylopyranosyl-(1 --> 4)-ß-D-glucopyranoside)] (2) on the basis of spectroscopic means including HRESIMS, 1D, and 2D NMR experiments.


Assuntos
Medicamentos de Ervas Chinesas/isolamento & purificação , Glicosídeos/isolamento & purificação , Ophiopogon/química , Fitosteróis/isolamento & purificação , Saponinas/isolamento & purificação , Esteróis/isolamento & purificação , Medicamentos de Ervas Chinesas/química , Glicosídeos/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Fitosteróis/química , Raízes de Plantas/química , Saponinas/química , Estereoisomerismo , Esteróis/química
17.
Zhongguo Zhong Yao Za Zhi ; 34(20): 2610-2, 2009 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-20069903

RESUMO

OBJECTIVE: To investigate the chemical constituents from roots of Boehmeria nivea. METHOD: The constituents were isolated by repeated column chromatography and preparative liquid chromatography; and their structures were elucidated by chemical properties and spectroscopic analyses. RESULT: Seven compounds were isolated and their structures were identified as tormentic acid (1), hederagenin (2), maslinic acid (3), 2alpha-hydroxyursolic acid (4), trans-p-hydroxycinamic acid (5), 2,4,4'-trihydroxychalcone (6), rutin (7). CONCLUSION: Compounds 1-6 were obtained from this genus for the first time.


Assuntos
Boehmeria/química , Medicamentos de Ervas Chinesas/análise , Raízes de Plantas/química , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/análise , Triterpenos/análise
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