Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
ACS Appl Mater Interfaces ; 15(50): 58784-58793, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38084743

RESUMO

The design and synthesis of high-efficiency electrocatalysts are of great practical significance in electrocatalytic water splitting, specifically in accelerating the slow oxygen evolution reaction (OER). Herein, a self-supported bismuth-doped NiFe layered double hydroxide (LDH) nanosheet array for water splitting was successfully constructed on nickel foam by a one-step hydrothermal strategy. Benefiting from the abundant active sites of two-dimensional nanosheets and electronic effect of Bi-doped NiFe LDH, the optimal Bi0.2NiFe LDH electrocatalyst exhibits excellent OER performance in basic media. It only requires an overpotential of 255 mV to drive 50 mA cm-2 and a low Tafel slope of 57.49 mV dec-1. The calculation of density functional theory (DFT) further shows that the incorporation of Bi into NiFe LDH could obviously overcome the step of H2O adsorption during OER progress. This work provides a simple and effective strategy for improving the electrocatalytic performance of NiFe LDHs, which is of great practical significance.

2.
Molecules ; 28(24)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38138583

RESUMO

The development of an efficient catalyst with excellent performance using agricultural biomass waste as raw materials is highly desirable for practical water pollution control. Herein, nano-sized, metal-decorated biochar was successfully synthesized with in situ chemical deposition at room temperature. The optimized BC-Cu (1:4) composite exhibited excellent peroxymonosulfate (PMS) activation performance due to the enhanced non-radical pathway. The as-prepared BC-Cu (1:4) composite displays a superior 99.99% removal rate for ciprofloxacin degradation (initial concentration 20 mg·L-1) within 40 min. In addition, BC-Cu (1:4) has superior acid-base adaptability (3.98~11.95) and anti-anion interference ability. The trapping experiments and identification of reactive oxidative radicals confirmed the crucial role of enhanced singlet oxygen for ciprofloxacin degradation via a BC-Cu (1:4)/PMS system. This work provides a new idea for developing highly active, low-cost, non-radical catalysts for efficient antibiotic removal.


Assuntos
Ciprofloxacina , Poluentes Químicos da Água , Cobre , Água , Poluentes Químicos da Água/análise , Peróxidos
3.
J Genet Genomics ; 50(12): 948-959, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37286164

RESUMO

Protein O-GlcNAcylation is a monosaccharide post-translational modification maintained by two evolutionarily conserved enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Mutations in human OGT have recently been associated with neurodevelopmental disorders, although the mechanisms linking O-GlcNAc homeostasis to neurodevelopment are not understood. Here, we investigate the effects of perturbing protein O-GlcNAcylation using transgenic Drosophila lines that overexpress a highly active OGA. We reveal that temporal reduction of protein O-GlcNAcylation in early embryos leads to reduced brain size and olfactory learning in adult Drosophila. Downregulation of O-GlcNAcylation induced by the exogenous OGA activity promotes nuclear foci formation of Polycomb-group protein Polyhomeotic and the accumulation of excess K27 trimethylation of histone H3 (H3K27me3) at the mid-blastula transition. These changes interfere with the zygotic expression of several neurodevelopmental genes, particularly shortgastrulation (sog), a component of an evolutionarily conserved sog-Decapentaplegic (Dpp) signaling system required for neuroectoderm specification. Our findings highlight the importance of early embryonic O-GlcNAcylation homeostasis for the fidelity of facultative heterochromatin redeployment and initial cell fate commitment of neuronal lineages, suggesting a possible mechanism underpinning OGT-associated intellectual disability.


Assuntos
Drosophila , Heterocromatina , Animais , Humanos , Drosophila/genética , Drosophila/metabolismo , Heterocromatina/genética , Processamento de Proteína Pós-Traducional , Homeostase , Desenvolvimento Embrionário/genética , N-Acetilglucosaminiltransferases/genética , N-Acetilglucosaminiltransferases/metabolismo
4.
J Chromatogr A ; 1692: 463849, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36764066

RESUMO

A facile in-situ ionothermal synthesis strategy for fabrication of ionic liquids/metal-organic frameworks (MOFs) (ILs@ZIF-8) nanocomposites hybrid monolith has been proposed to facilitate highly effective capillary microextraction (CME) of ultra-trace microcystins (MCs) in environmental waters. The ZnO nanoparticles (ZnO-NPs) were initially introduced into a precursor polymer monolith, and acted as the metal sources and anchoring seeds to construct ILs@ZIF-8 nanocomposites hybrid monolith via a nanoparticle-directed in-situ growth route in confined imidazolium ionic liquids. Detailed characterization based on scanning electron microscopy (SEM), X-ray diffraction (XRD) and N2 adsorption-desorption isotherms confirmed that both the morphology and porous structure of ZIF-8 were finely tuned by the incorporation of ILs, which acted as solvents and structure directing agent. The confinement of ILs in ZIF-8 framework endows the ILs@ZIF-8 hybrid monolith additional adsorption sites and satisfied water stability for the synergistic enhancement of adsorption efficiency of MCs via multiple interactions (including π-π stacking, hydrogen bonding, hydrophobic and electrostatic interactions). Coupling ILs@ZIF-8 hybrid monolith-based CME to LC-MS enabled an efficient and sensitive analysis of MCs in surface waters with ultra-low detection limits (LOD ≤ 1.4 ng L-1) and satisfactory recoveries (70.2%-107.0%). This study showed great potential for feasible design and fabrication of ILs@MOFs composites with synergistic and tunable structures toward efficient sample preparation applications.


Assuntos
Líquidos Iônicos , Estruturas Metalorgânicas , Nanocompostos , Óxido de Zinco , Líquidos Iônicos/química , Microcistinas , Nanocompostos/química
5.
Front Mol Neurosci ; 15: 864074, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35813073

RESUMO

Objective: ADGRV1 gene encodes adhesion G protein-coupled receptor-V1 that is involved in synaptic function. ADGRV1 mutations are associated with audio-visual disorders. Although previous experimental studies suggested that ADGRV1 variants were associated with epilepsy, clinical evidence is limited and the phenotype spectrum is to be defined. Methods: Trio-based targeting sequencing was performed in a cohort of 101 cases with febrile seizure (FS) and epilepsy with antecedent FS. Protein modeling was used to assess the damaging effects of variants. The genotype-phenotype correlations of the ADGRV1 variants in epilepsy and audio-visual disorders were analyzed. Results: ADGRV1 variants were identified in nine unrelated cases (8.91%), including two heterozygous frameshift variants, six heterozygous missense variants, and a pair of compound heterozygous variants. These variants presented a statistically higher frequency in this cohort than that in control populations. Most missense variants were located at CalX-ß motifs and changed the hydrogen bonds. These variants were inherited from the asymptomatic parents, indicating an incomplete penetrance. We also identified SCN1A variants in 25 unrelated cases (24.75%) and SCN9A variants in 3 unrelated cases (2.97%) in this cohort. Contrary to SCN1A variant-associated epilepsy that revealed seizure was aggravated by sodium channel blockers, ADGRV1 variants were associated with mild epilepsy with favorable responses to antiepileptic drugs. The patients denied problems with audio-visual-vestibular abilities in daily life. However, audio-visual tests revealed auditory and visual impairment in the patient with compound heterozygous variants, auditory or vestibular impairment in the patients with heterozygous frameshift, or hydrogen-bond changed missense variants but no abnormalities in the patients with missense variants without hydrogen-bond changes. Previously reported ADGRV1 variants that were associated with audio-visual disorders were mostly biallelic/destructive variants, which were significantly more frequent in the severe phenotype of audio-visual disorders (Usher syndrome 2) than in other mild phenotypes. In contrast, the variants identified in epilepsy were monoallelic, missense mainly located at CalX-ß, or affected isoforms VLGR1b/1c. Significance: ADGRV1 is potentially associated with FS-related epilepsy as a susceptibility gene. The genotype, submolecular implication, isoforms, and damaging severity of the variants explained the phenotypical variations. ADGRV1 variant-associated FS/epilepsy presented favorable responses to antiepileptic drugs, implying a clinical significance.

6.
Nat Commun ; 13(1): 3501, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715442

RESUMO

Transposable elements (TEs) through evolutionary exaptation have become an integral part of the human genome, offering ample regulatory sequences and shaping chromatin 3D architecture. While the functional impacts of TE-derived sequences on early embryogenesis have been recognized, their roles in malignancy are only starting to emerge. Here we show that many TEs, especially the pluripotency-related human endogenous retrovirus H (HERVH), are abnormally activated in colorectal cancer (CRC) samples. Transcriptional upregulation of HERVH is associated with mutations of several tumor suppressors, particularly ARID1A. Knockout of ARID1A in CRC cells leads to increased transcription at several HERVH loci, which involves compensatory contribution by ARID1B. Suppression of HERVH in CRC cells and patient-derived organoids impairs tumor growth. Mechanistically, HERVH transcripts colocalize with nuclear BRD4 foci, modulating their dynamics and co-regulating many target genes. Altogether, we uncover a critical role for ARID1A in restraining HERVH, whose abnormal activation can promote tumorigenesis by stimulating BRD4-dependent transcription.


Assuntos
Retrovirus Endógenos , Fatores de Transcrição , Proteínas de Ciclo Celular/genética , Cromatina/genética , Elementos de DNA Transponíveis , Proteínas de Ligação a DNA/genética , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Humanos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fatores de Transcrição/genética
7.
Analyst ; 147(10): 2253-2263, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35510541

RESUMO

A monolithic-based mixed-mode stationary phase was prepared for capillary electrochromatography via the fast photoinitiated polymerization of 2-methacryloyloxyethyl phosphorylcholine and polyhedral oligomeric silsesquioxane methacrylate (POSS-MA) monomers in the presence of crosslinker pentaerythritol triacrylate (PETA). Several copolymerization parameters, including the composition of monomers or porogens, ratio of crosslinkers to monomers, and polymerization time, were systematically optimized to tune the permeability and efficiency of monolithic columns. The morphologies and structures of the as-prepared monoliths were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, thermogravimetry and nitrogen adsorption/desorption analysis, indicating a typical POSS skeleton morphology with numerous mesopores on the monolith. Owing to the incorporation of zwitterionic functional groups and rigid POSS skeleton on the hybrid monolith, the resulting stationary phase exhibited both hydrophilic and electrostatic interactions, as well as good mechanical stability. Pressurized CEC separation of various kinds of polar compounds such as amides, nucleobases, nucleosides and benzoic acids, and polypeptide antibiotics was achieved by mixed-mode retention mechanisms including hydrophilic interaction chromatography (HILIC) and weak cation exchange chromatography (WCX) with a high column efficiency up to 93 500 plates per m (thiourea).


Assuntos
Eletrocromatografia Capilar , Eletrocromatografia Capilar/métodos , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Nucleosídeos , Fosforilcolina , Polimerização
8.
Talanta ; 243: 123397, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35325743

RESUMO

A novel molecularly imprinted monolithic (MIM) column was designed and fabricated using the epitope approach, and was used for the selective capillary microextraction (CME) of the neuropeptides neurotensin (NT) and neuromedin N (NmN). The MIMs were synthesized in a capillary by thermally initiated polymerization of the functional monomer (methacrylic acid (MAA)), in the presence of a dummy template (Pro-Tyr-Ile-Leu (PYIL)), a crosslinker and porogens. The resulting monoliths were characterized by scanning electron microscopy, pore size distribution measurement, and Fourier transform infrared spectroscopy. Different synthesis conditions of the MIM column were investigated. The parameters affecting the MIM-CME performance, including loading, washing and elution protocols, were optimized as well. The MIMs were used to enrich NT and NmN from human plasma prior to HPLC-UV analysis. The imprinted monolith showed an excellent maximum adsorption capacity of 245-711 mg mL-1 and selectivity (imprinting factor of 5.7-13.4) towards its target peptides. Low detection limits of 0.62 and 1.20 nM, and satisfactory recoveries (82.5-98.8%) were obtained for NT and NmN, respectively. The proposed MIM-CME/HPLC-UV method was found suitable to be used as an effective tool for the highly efficient and specific analysis of NT and NmN in human plasma samples.


Assuntos
Impressão Molecular , Neuropeptídeos , Cromatografia Líquida de Alta Pressão/métodos , Epitopos , Humanos , Impressão Molecular/métodos , Polimerização
9.
J Chromatogr A ; 1659: 462651, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34749184

RESUMO

A novel polyhedral oligomeric siloxane (POSS)-based zwitterionic monolithic capillary column was prepared via one-pot polymerization in ionic liquid porogen, using N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine (DMMSA) and methacrylic ethyl trimethylammonium chloride (META) as binary functional monomers, and methacryl substituted POSS as cross-linker. The pore structure, permeability and homogeneity were well tuned by optimizing the polymerization conditions. The resultant monolith was characterized by scanning electron microscopy, nitrogen adsorption/desorption isotherm and Fourier transform infrared spectroscopy. The incorporation of zwitterionic ligand (DMMSA), quaternary amine group (META) and rigid POSS skeleton endows the hybrid organic-silica monolith with high hydrophilicity, electrostatic interaction and good mechanical stability, as well as a tunable electroosmotic flow over wide pH range. A close investigation of capillary electrochromatographic separations of different types of polar compounds such as bases, nucleosides and benzoic acids on such stationary phase exhibited a retention independent column efficiency up to 118,000 plates/m (thiourea), as well as a mixed-mode hydrophilic interaction chromatography (HILIC) retention mechanism including weak electrostatic interaction, hydrophobic interaction and anion exchange.


Assuntos
Eletrocromatografia Capilar , Líquidos Iônicos , Interações Hidrofóbicas e Hidrofílicas , Polimerização , Siloxanas
10.
PLoS Biol ; 18(10): e3000891, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33090988

RESUMO

Externally deposited eggs begin development with an immense cytoplasm and a single overwhelmed nucleus. Rapid mitotic cycles restore normality as the ratio of nuclei to cytoplasm (N/C) increases. A threshold N/C has been widely proposed to activate zygotic genome transcription and onset of morphogenesis at the mid-blastula transition (MBT). To test whether a threshold N/C is required for these events, we blocked N/C increase by down-regulating cyclin/Cdk1 to arrest early cell cycles in Drosophila. Embryos that were arrested two cell cycles prior to the normal MBT activated widespread transcription of the zygotic genome including genes previously described as N/C dependent. Zygotic transcription of these genes largely retained features of their regulation in space and time. Furthermore, zygotically regulated post-MBT events such as cellularization and gastrulation movements occurred in these cell cycle-arrested embryos. These results are not compatible with models suggesting that these MBT events are directly coupled to N/C. Cyclin/Cdk1 activity normally declines in tight association with increasing N/C and is regulated by N/C. By experimentally promoting the decrease in cyclin/Cdk1, we uncoupled MBT from N/C increase, arguing that N/C-guided down-regulation of cyclin/Cdk1 is sufficient for genome activation and MBT.


Assuntos
Blástula/citologia , Pontos de Checagem do Ciclo Celular , Núcleo Celular/metabolismo , Drosophila melanogaster/embriologia , Embrião não Mamífero/citologia , Regulação da Expressão Gênica no Desenvolvimento , Interfase , Zigoto/metabolismo , Animais , Pontos de Checagem do Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Gastrulação , Interfase/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Gênica , Transcriptoma/genética
11.
J Chromatogr A ; 1623: 461175, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505279

RESUMO

An ionic liquid hybrid zwitterionic polymer capillary microextraction (CME) column was prepared for the biomimetic enrichment of glycopeptides by one-step copolymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 1-butyl-3-vinylimidazolium bromide, in the presence of crosslinker trimethylolpropane trimethacrylate (TMA). The resultant monolith was characterized by scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy and pore size distribution measurement. Due to the incorporation of zwitterionic MPC owning a unique biomimic structure (i.e. hydrophilic cation/anion and hydrophobic long-alkyl chain), the monolithic column has large pore size and good biocompatibility, exhibiting high extraction efficiency, permeability and fast mass transfer to targets. Besides, the use of ionic liquids (ILs) as co-monomer in the polymerization endows the monolith with enhanced mechanical stability, uniformity and multiple interactions. The prepared column was successfully applied in CME coupled to capillary electrochromatography (CEC) for the efficient enrichment and separation of glycopeptide antibiotics in foodstuff. The method demonstrated a wide linear range (50.0-18000.0 µg L-1), low detection limits (5.0-10.0 µg L-1, S/N = 3) and satisfied recoveries (76.0-109.7%). This work shows the advantage of fine-tuning biomimetic monoliths in application-specific CME-CEC.


Assuntos
Antibacterianos/análise , Eletrocromatografia Capilar/métodos , Glicopeptídeos/análise , Líquidos Iônicos/química , Antibacterianos/isolamento & purificação , Materiais Biomiméticos , Fracionamento Químico , Análise de Alimentos/métodos , Glicopeptídeos/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Metacrilatos/química , Microscopia Eletrônica de Varredura , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Polimerização , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Compostos de Vinila/química
12.
Genomics ; 112(3): 2426-2432, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31982476

RESUMO

Alzheimer's disease (AD) is a chronic neurodegenerative disease. The genetic risk factors of AD remain better understood. Using previously published dataset of common single nucleotide polymorphisms (SNPs), we studied the association between the minor allele content (MAC) in an individual and AD. We found that AD patients have higher average MAC values than matched controls. We identified a risk prediction model that could predict 2.19% of AD cases. We also identified 49 genes whose expression levels correlated with both MAC and AD. By pathway and process enrichment analyses, these genes were found in pathways or processes closely related to AD. Our study suggests that AD may be linked with too many genetic variations over a threshold. The method of correlations with both MAC and traits appears to be effective in high efficiency identification of target genes for complex traits.


Assuntos
Alelos , Doença de Alzheimer/genética , Expressão Gênica , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo Único , Medição de Risco
13.
J Chromatogr A ; 1597: 167-178, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-30929865

RESUMO

A simple thiol-ene photopolymerization approach was developed for the rapid preparation of ionic liquid-functionalized hybrid monolithic column based on polyhedral oligomeric silsesquioxane (POSS). "One-pot" polymerization was realized in the UV-transparent fused-silica capillary by using octanethiol, 1-allyl-3-methylimidazolium hexafluorophosphate as functional monomers and methacryl-substituted POSS as a crosslinker. The thiol-vinyl-methacrylate ternary system uniquely exhibits a mixed step-chain growth polymerization regime that combining the thiol-ene reaction and free-radical reaction mechanisms, which provides a simple route to prepare novel POSS-based functionalized hybrid monoliths. The pore property, permeability, and electroosmotic flow (EOF) of the hybrid monoliths can be tailored by proper adjustment of the feeding composition and initiation condition. Morphologic and spectroscopic characterizations of monolithic columns clearly indicate that utilization of the photo-initiated approach in thiol-vinyl polymerization can generate a more homogeneous porous structure, smaller domain size and higher column efficiency (53,800-60,300 plates/m for alkylbenzenes) than the thermally-initiated one (32,800-49,300 plates/m). Significant improvements in mechanical stability, anti-swelling property and tailorability of hybrid polymer were achieved in a simple manner, owing to the photopolymerization of rigid nanoscale POSS units and imidazolium-based ionic liquids in ternary thiol-vinyl system for the first time. The resulting hybrid monolith possessed controllable EOFs at pH values from 2 to 10, and showed a multimode separation mechanism in capillary electrochromatography, including π-π interaction, ion exchange, electrophoretic migration, electrostatic and hydrophobic interaction. Satisfactory separation ability was achieved for the analysis of different types of small molecules.


Assuntos
Eletrocromatografia Capilar/instrumentação , Técnicas de Química Analítica/instrumentação , Técnicas de Química Analítica/métodos , Líquidos Iônicos/química , Compostos de Organossilício/química , Eletro-Osmose , Radicais Livres/química , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Polimerização , Compostos de Sulfidrila/química , Compostos de Vinila/química
14.
J Chromatogr A ; 1598: 49-57, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30954244

RESUMO

A direct immersion solid-phase microextraction (DI-SPME) approach for gas chromatography-mass spectrometry (GC-MS) based on hybrid fiber coating of ionic liquid and polyhedral oligomeric silsesquioxane (POSS) is presented. To fabricate the task-specific coating for the enrichment of polycyclic aromatic hydrocarbons (PAHs), 1-butyl-3-vinylimidazolium bis[(trifluoromethyl)sulfonyl]imide (IL) and POSS were rapidly photoinitiated copolymerized within 5 min on a stainless steel fiber. The high efficient extraction of target analytes can be attributed to a combined result of multiple interactions including the strong CF⋯HC pseudohydrogen bonding, π-π stacking, hydrophobic force, and molecular sieve effect. A wide linear range (0.04-400 ng L-1) with low detection limits in the range of 0.004 and 0.5 ng L-1 were obtained for PAHs by GC-MS. The applicability of this coupling method was successfully demonstrated by the analysis of trace PAHs in real river water and soil samples, with satisfied recoveries (84.2-108.6%) and relative standard deviations (<8.1%). Compared to the other commercial fiber-based SPME methods, the IL/POSS hybrid coating-based SPME is much cheaper, thermally stable and capable of eliminating possible deleterious effects as well.


Assuntos
Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas , Líquidos Iônicos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Microextração em Fase Sólida , Água Doce/química , Limite de Detecção , Solo/química
15.
Se Pu ; 36(3): 309-316, 2018 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-30136511

RESUMO

A rapid and sensitive method was established for the analysis of peptide antibiotics (bacitracin, polymyxin B and colistin) in animal food by capillary electrochromatography (CEC) coupled with laser induced fluorescence (LIF) using 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) as fluorogenic reagent. Peptide antibiotics were derivatized by NBD-F in 50 mmol/L borate buffer (pH 7.5) for 45 min at 60℃. The fluorescence derivatives of peptide antibiotics were separated on a packed phenyl capillary column with a mobile phase consisting of acetonitrile-potassium phosphate (pH 5.0, 10 mmol/L) (55:45, v/v) at the flow rate of 0.02 mL/min. A supplementary pressure of 3.8 MPa and a separation voltage of -10 kV were applied. The limits of detection (LODs, S/N=3) were 5.0-10.0 ng/mL, which fulfilled the requirement of maximum residue limits for examined peptide antibiotics. The method was applied to detect peptide antibiotics in milk and feed stuffs. The spiked recoveries of the three peptide antibiotics were 72.9%-112.4%. The method shows some advantages on the simpler pretreatment and higher sensitivity, which can be of great benefit to the residual analysis of the veterinary drugs.


Assuntos
Ração Animal/análise , Antibacterianos/análise , Eletrocromatografia Capilar , Fluorescência , Peptídeos/análise , Indicadores e Reagentes
16.
Mikrochim Acta ; 185(7): 318, 2018 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-29876757

RESUMO

An ionic liquid hybrid monolithic capillary column was prepared within 7 min via photoinitiated free-radical polymerization of an ionic liquid monomer (1-butyl-3-vinylimidazolium-bis[(trifluoromethyl)sulfonyl]imide); VBIMNTF2) and a methacryl substituted polyhedral oligomeric silsesquioxane (POSS-MA) acting as a cross-linker. The effects of composition of prepolymerization solution and initiation time on the porous structure and electroosmotic flow (EOF) of monolithic column were investigated. The hybrid monolith was characterized by scanning electron microscopy and FTIR. Owing to the introduction of a rigid nanosized POSS silica core and ionic liquids with multiple interaction sites, the monolithic column has a well-defined 3D skeleton morphology, good mechanical stability, and a stable anodic electroosmotic flow. The hybrid monolithic stationary phase was applied to the capillary electrochromatographic separation of various alkylbenzenes, phenols, anilines and polycyclic aromatic hydrocarbons (PAHs). The column efficiency is highest (98,000 plates/m) in case of alkylbenzenes. Mixed-mode retention mechanisms including hydrophobic interactions, π-π stacking, electrostatic interaction and electrophoretic mobility can be observed. This indicates the potential of this material in terms of efficient separation of analytes of different structural type. Graphical Abstract Preparation of a mixed-mode ionic liquid hybrid monolithic column via photoinitiated polymerization of methacryl substituted polyhedral oligomeric silsesquioxane (POSS-MA) and 1-butyl-3-vinylimidazolium-bis[(trifluoromethyl)sulfonyl]imide (VBIMNTF2) ionic liquid for use in capillary electrochromatography.

17.
J Chromatogr A ; 1556: 10-20, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-29729861

RESUMO

A hydrophilic ionic liquids based polymer monolith microextraction (PMME) column (poly(ionic liquid-co-hydroxyethyl methacrylate-co-ethylene dimethacrylate); poly(IL-co-HEMA-co-EDMA)) was prepared for the first time in a capillary and utilized in PMME for the enrichment of glycopeptide antibiotics (GAs), followed by the online coupling analysis of capillary liquid chromatography with amperometric detection (cLC-AD). The prepared monolith exhibited large through pores and good storage stability, as well as a selective extraction machanism for GAs that was attributed to the hydrogen bonding, hydrophilic, electrostatic and π-π interactions between GAs and the imidazolium cations or hydroxyl groups on the surface of absorbent. Several experimental parameters, such as sample flow rate, composition of eluent and solvent desorption conditions, were examined to improve the extraction efficiency of PMME. Under the optimal conditions, the proposed PMME-cLC-AD method provides detection limits (S/N = 3) of 1.0-8.0 µg L-1 for three GAs, which are 1000-fold lower than those obtained by cLC-AD, with a wide linear range of 10.0-12000.0 µg L-1. It was successfully applied for the analysis of GAs residues in feed samples with good recoveries (80.3-119.1%) and satisfied intra-day/inter-day precision (<10%). Compared with LC-3Q-MS method, the proposed online approach has the merits of simple, low cost, smaller matrix interference and environmental friendly, which is demonstrated to be a feasible tool for residue analysis of peptide antibiotics in food safety application.


Assuntos
Antibacterianos/análise , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica/métodos , Glicopeptídeos/análise , Interações Hidrofóbicas e Hidrofílicas , Líquidos Iônicos/química , Polímeros/química , Microextração em Fase Sólida/métodos , Acetonitrilas/química , Metacrilatos/química , Polimerização , Porosidade , Reprodutibilidade dos Testes , Reologia , Solventes , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo
18.
Heredity (Edinb) ; 121(6): 537-547, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29523840

RESUMO

Lung cancer is the leading cause of cancer deaths in both men and women in the US. While most sporadic lung cancer cases are related to environmental factors such as smoking, genetic susceptibility may also play an important role and a number of lung cancer associated single-nucleotide polymorphisms (SNPs) have been identified although many remain to be found. The collective effects of genome-wide minor alleles of common SNPs, or the minor allele content (MAC) in an individual, have been linked with quantitative variations of complex traits and diseases. Here we studied MAC in lung cancer using previously published SNPs data sets (US and Finland samples) and found higher MAC in cases relative to matched controls. A set of 5400 SNPs with MA (MAF < 0.5) more common in cases (P < 0.08) and linkage disequilibrium (LD) r2 = 0.3 was found to have the best predictive accuracy. These results identify higher MAC in lung cancer susceptibility and provide a meaningful genetic method to identify those at risk of lung cancer.


Assuntos
Predisposição Genética para Doença , Neoplasias Pulmonares/genética , Polimorfismo de Nucleotídeo Único , Alelos , Estudos de Casos e Controles , Finlândia , Humanos , Análise de Componente Principal , Estados Unidos
19.
PLoS One ; 13(1): e0191210, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29315351

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0187644.].

20.
PLoS One ; 12(11): e0187644, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29099854

RESUMO

Type 2 diabetes (T2D) is a complex disorder characterized by high blood sugar, insulin resistance, and relative lack of insulin. The collective effects of genome wide minor alleles of common SNPs, or the minor allele content (MAC) in an individual, have been linked with quantitative variations of complex traits and diseases. Here we studied MAC in T2D using previously published SNP datasets and found higher MAC in cases relative to matched controls. A set of 357 SNPs was found to have the best predictive accuracy in a British population. A weighted risk score calculated by using this set produced an area under the curve (AUC) score of 0.86, which is comparable to risk models built by phenotypic markers. These results identify a novel genetic risk element in T2D susceptibility and provide a potentially useful genetic method to identify individuals with high risk of T2D.


Assuntos
Alelos , Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Adulto , Feminino , Humanos , Masculino , Modelos Teóricos , Reino Unido
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...