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1.
Plant Mol Biol ; 102(4-5): 417-430, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31898146

RESUMO

KEY MESSAGE: We genome-wide identified 28 JmjC domain-containing genes, further spatio-temporal expression profiling and genetic analysis defined them as epigenetic regulators in flowering initiation of Rosa chinensis. The JmjC domain-containing histone demethylases play critical roles in maintaining homeostasis of histone methylations, thus are vital for plant growth and development. Genome-wide identification of the JmjC domain-containing genes have been reported in several species, however, no systematic study has been performed in rose plants. In this paper, we identified 28 JmjC domain-containing genes from the newly published genome database of Rosa chinensis. The JmjC domain-containing proteins in R. chinensis were divided into seven groups, KDM3 was the largest group with 13 members, and JmjC domain-only A and KDM5B were the smallest clades both with only one member. Although all the JmjC domain proteins having a conserved JmjC domain, the gene and protein structure experienced differentiation and specification during the evolution, especially in KDM3 clade, one gene (RcJMJ40) was found carrying site deletions for cofactors Fe (II) and α-KG binding which were crucial for demethylase activities, three genes (RcJMJ41, RcJMJ43 and RcJMJ44) had no intron while two of them had tandem JmjC domains. Spatial expression pattern analysis of these JmjC domain-containing genes in different tissues showed most of them were highly expressed in reproductive tissues such as floral meristem and closed flowers than vegetative tissues, demonstrating their important functions in developmental switch from vegetative to reproductive growth of roses. Temporal expression profiling indicated majority of JmjC domain-containing genes from R. chinensis fluctuated along with floral bud differentiation and development, further proving their essential roles in flower organogenesis. VIGS induced silencing of RcJMJ12 led to delayed flowering time, and decreased the expression levels of flowering integrator such as RcFT, RcSOC1, RcFUL, RcLFY and RcAP1, therefore providing the genetic evidence of RcJMJ12 in flowering initiation. Collectively, spatio-temporal expression profiling and genetic analysis defined the JmjC domain-containing genes as important epigenetic regulators in flower development of R. chinensis.

2.
Microbiologyopen ; 9(1): e00956, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31631574

RESUMO

3-Hydroxypropionic acid (3HP) is an important platform chemical with a wide range of applications. The biological preparation of this compound is safe and low cost. In this study, orchard soil and human waste were used as raw materials to screen microbial strains that could produce 3HP in selective medium containing varying amounts of propionic acid. A yeast strain that can use propionic acid as substrate and produce 48.96 g/L 3HP was screened. Morphological observation, physiological and biochemical identification, and 26s rDNA sequencing identified the IS451 strain as Debaryomyces hansenii. The low-energy ion N+ , with the energy of 10 keV and a dose of 70 × 2.6 × 1013  ions/cm2 , was implanted into the IS451 strain. The mutant strain WT39, whose 3HP titer reached 62.42 g/L, was obtained. The strain exhibited genetic stability and tolerance to high concentrations of propionic acid and was considered to have broad application prospects.

3.
Wei Sheng Yan Jiu ; 48(4): 621-627, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31601346

RESUMO

OBJECTIVE: To investigate the effect of the interaction between methylenetetrahydrofolate reductase(MTHFR) genotype and allele and long-term exposure to organophosphorus pesticides on the development of type 2 diabetes mellitus(T2 DM). METHODS: A total of 209 cases of T2 DM(case group) and 216 cases without T2 DM(control group) were selected as subjects. The polymorphism of MTHFR(rs1801133) was detected by TaqMan probe technique. The relationship between genes, long-term exposure to organophosphorus pesticides and T2 DM was analyzed by Logistic regression. The interaction between gene and long-term exposure to organophosphorus pesticides was discussed by crossover analysis and generalized multifactor dimensionality reduction. RESULTS: BMI⇿4, residence in countryside, long-term exposure to organophosphorus pesticides and family history of diabetes mellitus were risk factors for T2 DM. MTHFR genotype distribution conformed to Hardy-Weinberg equilibrium(P>0. 05). There was no significant difference in genotype distribution frequency between case group and control group. The risk of T2 DM in individuals with CT and TT genotypes was 1. 667 times higher than that of CC genotypes after adjusting the covariates at rs1801133 locus in the dominant model(95%CI 1. 057-2. 627, P=0. 028). It suggested that the samples of allele T had a increased risk of T2 DM compared with those without allele T. The above models still had statistical significance(P<0. 05) after adjusting the covariates. Forth, crossover analysis showed that the gene MTHFR(rs1801133) and long-term exposure to organophosphorus pesticides had multiplication interaction. The interaction between gene MTHFR(rs1801133) and long-term exposure to organophosphorus pesticides may play a role in the pathogenesis of T2 DM. Generalized multifactor dimensionality reduction(GMDR)analysis showed that the interaction model of MTHFR(rs1801133) gene and family history of diabetes mellitus was the best model. CONCLUSION: MTHFR(rs1801133) gene CT and TT genotype may be risk factors for T2 DM. The interaction between genetic polymorphism and environmental factors increases the risk of T2 DM.


Assuntos
Diabetes Mellitus Tipo 2/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Compostos Organofosforados/toxicidade , Praguicidas/toxicidade , Estudos de Casos e Controles , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único
4.
Biosci Rep ; 39(9)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31467174

RESUMO

The present study aims to evaluate the involvement of N-methyl-d-aspartate receptor and nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) system in antidepressant-like effects of Yueju pill (YJ), a Chinese herbal medicine. The immobility time in tail suspension test (TST) and forced swim test (FST) was used to assess the antidepressant effects. Prior administration of L-arginine (750 mg/kg, intraperitoneal [i.p.]), a NO synthase substrate that enhances NO signaling or sildenafil (5 mg/kg, i.p.), a phosphodiesterase 5 inhibitor that enhances cGMP, blunted the antidepressant-like activity of YJ (2.7 g/kg, i.g.). Co-treatment of ineffective dose of YJ (1.35 g/kg, i.g.) with one of the reagents that suppress the NO/cGMP signaling, including methylene blue (10 mg/kg, i.p.), an inhibitor of NO synthase; 7-NI (7-nitroinidazole, 30 mg/kg, i.p.), an nNOS specific inhibitor; L-NAME (10 mg/kg, i.p.), a non-specific inhibitor of NO synthase; and MK-801 (0.05 mg/kg, i.p.), an NMDA receptor antagonist, reduced the immobility time in TST and FST, compared with those in vehicle or single drug treatment groups. Neither above drugs alone or co-administrated with YJ affected locomotor activity or anxiety behavior in open field test. Thus, our results suggest that the antidepressant-like action of YJ may depend on the inhibition of NMDA/NO/cGMP pathway.

5.
Neurochem Int ; 121: 19-25, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30352262

RESUMO

Reticulons (RTNs) are a family of membrane-bound proteins that are dominantly localized to the endoplasmic reticulum (ER) membrane. RTN1-C is one member of RTNs abundantly expressed in the brain and has been shown to mediate neuronal injury in cerebral ischemia models. In the present study, we investigated the role of RTN1-C in an in vitro brain trauma model mimicked by traumatic neuronal injury (TNI) in primary cultured cortical neurons. TNI increased the expression of RTN1-C in cortical neurons but had no effect on RTN1-A and RTN1-B. Knockdown of RTN1-C with specific siRNA (Si-RTN1-C) significantly decreased cytotoxicity and apoptosis after TNI. The results of Ca2+ imaging showed that intracellular Ca2+ overload induced by TNI was attenuated by RTN1-C knockdown. Furthermore, the activation of metabotropic glutamate receptor 1 (mGluR1)-induced Ca2+ response was partially prevented by Si-RTN1-C transfection. We also evaluated the role of RTN1-C in store-operated Ca2+ entry (SOCE) in cortical neurons using the ER Ca2+ inducer thapsigargin (Tg). The results showed that knockdown of RTN1-C alleviated the SOCE-mediated Ca2+ influx and decreased the expression of stromal interactive molecule 1 (STIM1). In summary, the present study found that knockdown of RTN1-C protected neurons against TNI via preservation of intracellular Ca2+ homeostasis, which was associated with the inhibition of mGluR1-mediated ER Ca2+ release and suppression of STIM1-related SOCE. Thus, RTN1-C might represent a therapeutic target for traumatic brain injury (TBI) research.


Assuntos
Sinalização do Cálcio/fisiologia , Homeostase/fisiologia , Líquido Intracelular/metabolismo , Proteínas do Tecido Nervoso/biossíntese , Neurônios/metabolismo , Neurônios/patologia , Animais , Células Cultivadas , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Técnicas de Silenciamento de Genes/métodos , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Ratos , Ratos Sprague-Dawley
6.
Drug Chem Toxicol ; : 1-12, 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30264597

RESUMO

The widespread application of zinc oxide nanoparticles (nano-ZnO) has received increasing attention because of their potential risks to human health and the environment. This review summarizes the relationship between the toxic effects and physicochemical properties of nano-ZnO and the underlying toxicity mechanisms of nano-ZnO. This study presents the possible human health hazards posed by nano-ZnO exposure and the biotoxicity to bacteria, algae, higher plants, aquatic animals, terrestrial invertebrates and vertebrates in vitro and in vivo. The advances in research on the ecotoxicity of nano-ZnO and the potential risks to human health are discussed. Finally, the current research deficiencies in this area are identified, and recommendations for future research are proposed.

7.
J Med Genet ; 55(10): 650-660, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30166352

RESUMO

INTRODUCTION: Hereditary haemochromatosis (HH) caused by a homozygous p.C282Y mutation in haemochromatosis (HFE) gene has been well documented. However, less is known about the causative non-HFE mutation. We aimed to assess mutation patterns of haemochromatosis-related genes in Chinese patients with primary iron overload. METHODS: Patients were preanalysed for mutations in the classic HH-related genes: HFE, HJV, HAMP, TFR2 and SLC40A1. Whole exome sequencing was conducted for cases with variants in HJV signal peptide region. Representative variants were analysed for biological function. RESULTS: None of the cases analysed harboured the HFE p.C282Y; however, 21 of 22 primary iron-overload cases harboured at least one non-synonymous variant in the non-HFE genes. Specifically, p.E3D or p.Q6H variants in the HJV signal peptide region were identified in nine cases (40.9%). In two of three probands with the HJV p.E3D, exome sequencing identified accompanying variants in BMP/SMAD pathway genes, including TMPRSS6 p.T331M and BMP4 p.R269Q, and interestingly, SUGP2 p.R639Q was identified in all the three cases. Pedigree analysis showed a similar pattern of combination of heterozygous mutations in cases with HJV p.E3D or p.Q6H, with SUGP2 p.R639Q or HJV p.C321X being common mutation. In vitro siRNA interference of SUGP2 showed a novel role of downregulating the BMP/SMAD pathway. Site-directed mutagenesis of HJV p.Q6H/p.C321X in cell lines resulted in loss of membrane localisation of mutant HJV, and downregulation of p-SMAD1/5 and HAMP. CONCLUSION: Compound heterozygous mutations of HJV or combined heterozygous mutations of BMP/SMAD pathway genes, marked by HJV variants in the signal peptide region, may represent a novel aetiological factor for HH.


Assuntos
Proteínas Ligadas por GPI/genética , Variação Genética , Proteína da Hemocromatose/genética , Hemocromatose/genética , Sobrecarga de Ferro/genética , Sinais Direcionadores de Proteínas/genética , Proteínas Smad/genética , Adolescente , Adulto , Idoso , China , Estudos de Coortes , Feminino , Proteínas Ligadas por GPI/metabolismo , Hemocromatose/diagnóstico , Proteína da Hemocromatose/metabolismo , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas Smad/metabolismo , Sequenciamento Completo do Exoma , Adulto Jovem
8.
Regul Toxicol Pharmacol ; 98: 231-239, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30096342

RESUMO

Silver nanoparticles (Ag-NPs) are increasingly being applied in many consumer products due to their unique properties. Widespread use of Ag-NPs leads to an increasing human exposure to Ag-NPs in many different pathways. This review summarized the toxicity mechanisms of Ag-NPs based on various environmentally relevant test species, such as bacteria, cells, plants, aquatic animals and mammals, in both in vitro and in vivo experiments. Nanoparticles were usually exposed to combination chemicals but to single chemicals in the environment and thereby exert combined toxicities to the organisms. Therefore, the joint effects of nanomaterials and their co-existing characteristics were also discussed. The current knowledge gaps and safe product designs of Ag-NPs have been discussed in detail. The limited and existing data implied that understanding the toxicity mechanisms is crucial to the future research development of nanomaterials.


Assuntos
Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Ecotoxicologia , Humanos , Nanopartículas Metálicas/química , Prata/química
9.
Oncol Rep ; 40(3): 1684-1694, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30015944

RESUMO

An early diagnosis of colitis­associated colorectal cancer (CAC) is important for its clinical management. However, it is currently difficult to distinguish the different stages of CAC development. MicroRNA dysregulation is common in human colorectal disorders, however little is known regarding whether miRNA affects tumor progression by regulating inflammation. In the present study, we identified a novel miRNA (miR­449a), the expression of which was significantly reduced in CAC tissues than in paired adjacent non­cancerous tissues (ANTs). Notably, the level of miR­449a was in a markedly decreased pattern during the neoplastic transformation of ulcerative colitis (UC)­to­CAC, as demonstrated by both clinical investigations and the experimental mouse model induced by AOM/DSS treatment. In addition, we observed that decreased miR­449a expression was associated with advanced T or N status, later clinical stage and poor histological differentiation of CAC. Mechanistic studies revealed that miR­449a inhibited the growth and metastasis of human colon cancer cells by directly binding to the 3'­UTR of Notch­1 and thereby, suppressed the activation of the Notch signaling pathway. Therefore, these findings provide strong evidence for the translational potential of miR­449a in the discrimination of patients with UC that is likely to progress into CAC, from those unlikely to progress, as well as in the prognosis and diagnosis of CAC.


Assuntos
Biomarcadores Tumorais/metabolismo , Colite/complicações , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Animais , Apoptose , Azoximetano/toxicidade , Biomarcadores Tumorais/genética , Carcinógenos/toxicidade , Estudos de Casos e Controles , Proliferação de Células , Colite/induzido quimicamente , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/metabolismo , Sulfato de Dextrana/toxicidade , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Prognóstico , Receptor Notch1/genética , Receptor Notch1/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Regul Toxicol Pharmacol ; 98: 41-49, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30017903

RESUMO

Perfluorooctane sulfonate (PFOS) and ZnO nanoparticles (Nano-ZnO) are two kinds of environmental contaminants that have been frequently detected in natural waters. The potential joint toxicity of PFOS and nano-ZnO remains to be fully elucidated. The objective of this study was to evaluate co-exposure effects of PFOS and nano-ZnO on growth in initial generation (F0) zebrafish after chronic exposure and to examine possible parental transfer of PFOS and nano-ZnO transgenerational effects on the growth of first generation (F1) larvae. When zebrafish (2 h after incubation) were exposed to single- and co-exposure groups for 120 days, bioconcentration resulted in significantly less growth as measured by body length and body weight, higher mortality, and less spawning in the F0 generation. These effects were possibly due to the down-regulation of the expression of Vtg1 genes along with a sex hormone (T/E2) involved in the hypothalamus-pituitary-gonad (HPG) axis. Furthermore, after long-term exposure, less fertilization, less hatching, greater mortality and more malformation were found in the F1 generation. The down-regulation of genes and hormones might be responsible for transgenerational toxicity. This study suggested that chronic exposure to PFOS and nano-ZnO adversely impacts development, reproduction in the F0 generation, and offspring embryonic growth.


Assuntos
Ácidos Alcanossulfônicos/toxicidade , Desenvolvimento Embrionário/efeitos dos fármacos , Fluorcarbonetos/toxicidade , Nanopartículas/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Animais , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Estradiol/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Reprodução/efeitos dos fármacos , Testosterona/metabolismo , Vitelogeninas/genética , Peixe-Zebra , Proteínas de Peixe-Zebra/genética
11.
J Transl Med ; 16(1): 166, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29914513

RESUMO

BACKGROUND: A model was constructed using clinical and serum variables to discriminate between chronic hepatitis B (CHB) patients with and without significant necroinflammatory activity (score 4-18 vs. score 0-3). METHODS: Consecutive CHB patients who underwent liver biopsy were divided into two sequential groups: a training group (n = 401) and a validation group (n = 401). Multivariate analysis identified alanine aminotransferase, γ-glutamyltransferase, prothrombin time and albumin as independent predictors of necroinflammatory activity. RESULTS: The area under the receiver operating characteristic curve was 0.826 for the training group and 0.847 for the validation group. Using a cut-off score of H ≤ 0.375, significant necroinflammatory activity (score 4-18) was excluded with high accuracy [78.2% negative predictive value (NPV), 72% positive predictive value (PPV), and 90.8% sensitivity] in 238 (59.4%) of 401 patients in the training group and with the same certainty (88.1% NPV, 61.2% PPV, and 95.1% sensitivity) among 204 (50.9%) of 401 patients in the validation group. Similarly, applying a cut-off score of H > 0.720, significant necroinflammatory activity was correctly identified with high accuracy (90.8% PPV, 57.7% NPV, and 92.0% specificity) in 150 (37.4%) of 401 patients in the training group and with the same certainty (91.8% PPV, 64.6% NPV, and 95.4% specificity) in 188 (46.9%) of 401 patients in the validation group. CONCLUSIONS: A predictive model based on easily accessible variables identified CHB patients with and without significant necroinflammatory activity with a high degree of accuracy. This model may decrease the need for liver biopsy for necroinflammatory activity grading in 72.1% of CHB patients.


Assuntos
Hepatite B Crônica/patologia , Inflamação/patologia , Fígado/patologia , Modelos Biológicos , Adulto , Biópsia , Estudos de Coortes , Feminino , Hepatite B Crônica/diagnóstico , Humanos , Modelos Logísticos , Masculino , Curva ROC , Reprodutibilidade dos Testes
12.
Chem Asian J ; 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29923686

RESUMO

The chemistry of metal-organic frameworks has been progressing fast with its exciting potential in multifunctional applications. A series of three-dimensional lanthanide-based metal-organic frameworks, {[Ln(HTPO)(NO3 )(H2 O)]⋅x(CH3 CN)⋅y(H2 O)}n (Ln=Eu (1), Tb (2), Gd (3), Sm (4), Dy (5), Nd (6)), {[Eu(TPO)(HCOO)0.5 ]⋅(H3 O)0.5 }n (7), {[Eu(TPO)(DMF)]⋅(solv)x }n (8; DMF= N,N-dimethylformamide), and {[Eu(TPO)(DMA)]⋅(solv)x }n (9; DMA=dimethylacetamide) were synthesized with semirigid C3 -symmetric ligand tris(4-carboxylphenyl)phosphine oxide (H3 TPO). In these frameworks, the H3 TPO ligand exists in a totally different configuration. Framework 1 exhibits good breathing properties for absorbing more guest molecules through a solvent-induced single-crystal-to-single-crystal (SC-SC) transformation involving a configuration transformation of the organic linker in the framework. The ytterbium ion was doped into 1 to improve the luminescent performance (lifetime and quantum yield) of the red europium emission. Among a series of Eu1-x Ybx TPO samples, Eu0.88 Yb0.12 TPO showed enhanced luminescence intensity (≈5.1 times that of the pure europium system), and the lifetime increased from 1073.08 to 1236.57 µs. Moreover, the porosity of these frameworks allows them to efficiently adsorb dye molecules with high selectivity and efficiency.

13.
Hortic Res ; 5: 25, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29736250

RESUMO

MIKCC-type MADS-box (MIKCC) genes encode transcription factors that have crucial roles in controlling floral organogenesis and flowering time in plants. Although this gene family has been well characterized in many plant species, its evolutionary and comprehensive functional analysis in rose is lacking. In this study, 58 non-redundant MIKCC uni-transcripts were extensively identified from rose transcriptomes. Phylogenetic analysis placed these genes into 12 clades with their Arabidopsis and strawberry counterparts, and revealed that ABCDE model (including AP1/FUL, AP3/PI, AG, and SEP clades), and SOC1 and AGL6 clade genes have remarkably expanded in Rosa chinensis, whereas genes from the FLC and AGL17 clades were undetectable. Sequence alignments suggest that the AP3/PI clade may contribute to more specific functions in rose due to a high variation of amino acid residues within its MADS-box domains. A comparative analysis of gene expression in specific floral organ differentiation stages and floral organs between R. chinensis cv. Old Blush and the closely related mutant genotype R. chinensis cv. Viridiflora (floral organs mutated into leaf-like structures) further revealed the roles of ABCDE model genes during floral organogenesis in rose. Analysis of co-expression networks provided an overview of the regulatory mechanisms of rose MIKCC genes and shed light on both the prominent roles of AP3/PI clade genes in floral organogenesis and the roles of RcAGL19, RcAGL24, and RcSOC1 in regulating floral transition in rose. Our analyses provide an overall insight of MIKCC genes in rose and their potential roles in floral organogenesis.

14.
Braz. j. microbiol ; 48(3): 515-521, July-Sept. 2017. graf
Artigo em Inglês | LILACS | ID: biblio-889145

RESUMO

Abstract Ammonia-oxidizing bacteria were immobilized by polyvinyl alcohol (PVA) and sodium alginate. The immobilization conditions and ammonia oxidation ability of the immobilized bacteria were investigated. The following immobilization conditions were observed to be optimal: PVA, 12%; sodium alginate, 1.1%; calcium chloride, 1.0%; inoculum concentration, 1.3 immobilized balls/mL of immobilized medium; pH, 10; and temperature, 30 °C. The immobilized ammonia-oxidizing bacteria exhibited strong ammonia oxidation ability even after being recycled four times. The ammonia nitrogen removal rate of the immobilized ammonia-oxidizing bacteria reached 90.30% under the optimal immobilization conditions. When compared with ammonia-oxidizing bacteria immobilized by sodium alginate alone, the bacteria immobilized by PVA and sodium alginate were superior with respect to pH resistance, the number of reuses, material cost, heat resistance, and ammonia oxidation ability.


Assuntos
Bactérias/química , Técnicas Microbiológicas/métodos , Amônia/metabolismo , Oxirredução , Álcool de Polivinil/química , Temperatura Ambiente , Bactérias/metabolismo , Técnicas Microbiológicas/economia , Técnicas Microbiológicas/instrumentação , Células Imobilizadas/metabolismo , Células Imobilizadas/química , Ácido Glucurônico/química , Alginatos/química , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio
15.
Dalton Trans ; 46(20): 6769-6775, 2017 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-28492624

RESUMO

A new simple 'dual' chemosensor MQA ((E)-2-methoxy-N-((quinolin-2-yl)methylene)aniline) for distinguishing Zn2+ and Hg2+ has been designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn2+/Hg2+ over other commonly coexisting cations (such as Na+, Mg2+, Al3+, K+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Ga3+, Cd2+, In3+ and Pb2+) in DMSO-H2O solution (1/99 v/v), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit for Zn2+/Hg2+ by MQA both reached the 10-8 M level. The 1 : 1 ligand-to-metal coordination patterns of the MQA-Zn2+ and MQA-Hg2+ were calculated through a Job's plot and ESI-MS spectra, and were further confirmed by X-ray crystal structures of complexes MQA-Zn2+ and MQA-Hg2+. This chemosensor can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions. DFT calculations have revealed that the energy gap between the HOMO and LUMO of MQA has decreased upon coordination with Zn(ii)/Hg(ii).

16.
ACS Appl Mater Interfaces ; 9(18): 15744-15757, 2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-28420233

RESUMO

The development of efficient sensors for detection of the water content in a wide detection range is highly desirable for balance in many industrial processes and products. Presented herein are six novel different substituted Schiff base Zn(II) complexes, which exhibit the remarkable capability to detect traces of water in a wide linear range (most can reach 0-94%, v/v), low detection limit of 0.2% (v/v), and rapid response time of 8 s in various organic solvents by virtue of an unusual water-activated hydrogen-bonding cross-linking AIE (WHCAIE) mechanism. As a proof-of-concept, the WHCAIE mechanism is explained well by single X-ray diffraction, absorption spectra, fluorescence spectra, dynamic light scattering, 1H NMR spectra, and theoretical calculations. In addition, the molecules demonstrated their application for the detection of humidity (42-80%). These Schiff base Zn(II) complexes become one of the most powerful water sensors known due to their extraordinary sensitivity, fast response, and wide detection range for water.

17.
Braz J Microbiol ; 48(3): 515-521, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28245966

RESUMO

Ammonia-oxidizing bacteria were immobilized by polyvinyl alcohol (PVA) and sodium alginate. The immobilization conditions and ammonia oxidation ability of the immobilized bacteria were investigated. The following immobilization conditions were observed to be optimal: PVA, 12%; sodium alginate, 1.1%; calcium chloride, 1.0%; inoculum concentration, 1.3 immobilized balls/mL of immobilized medium; pH, 10; and temperature, 30°C. The immobilized ammonia-oxidizing bacteria exhibited strong ammonia oxidation ability even after being recycled four times. The ammonia nitrogen removal rate of the immobilized ammonia-oxidizing bacteria reached 90.30% under the optimal immobilization conditions. When compared with ammonia-oxidizing bacteria immobilized by sodium alginate alone, the bacteria immobilized by PVA and sodium alginate were superior with respect to pH resistance, the number of reuses, material cost, heat resistance, and ammonia oxidation ability.


Assuntos
Amônia/metabolismo , Bactérias/química , Técnicas Microbiológicas/métodos , Alginatos/química , Bactérias/metabolismo , Células Imobilizadas/química , Células Imobilizadas/metabolismo , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Técnicas Microbiológicas/economia , Técnicas Microbiológicas/instrumentação , Oxirredução , Álcool de Polivinil/química , Temperatura Ambiente
18.
Dalton Trans ; 46(13): 4265-4277, 2017 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-28280820

RESUMO

A series of lanthanide coordination polymers(LnCPs) containing both light and heavy rare-earth elements, namely {[Eu2(pydc)3(H2O)]·2H2O}n (1-Eu, H2pydc = pyridine-2,3-dicarboxylic acid), [Ln(pyc)2(Hpyc)(NO3)]n (Ln = Nd (2-Nd), Sm (3-Sm), Eu (4-Eu), Gd (5-Gd), Tb (6-Tb), Ho (7-Ho), and Er (8-Er), Hpyc = pyridine-3-carboxylic acid), has been synthesized under hydro(solvo)thermal conditions and fully characterized. The crystal structure analysis indicates that in situ decarboxylation of H2pydc occurred in the synthesis process of 2-Nd-8-Er. Coordination polymer 1-Eu displays a 3-D pcu network with central-symmetric quad-core structural units [Eu4(COO)6] linked by 1-D chains. 2-Nd-8-Er are of triple helical chain enantiomeric pair 61/65 axis, and can be further linked through two separate kinds of Hbonding interaction to form a mirror symmetrical 3-D framework; the final topological symbol of the jointly connected network is rare {47·68}. Solid-state luminescence studies show that the emission spectra of these LnCPs cover both the visible and near-infrared luminescence region. 2-Nd exhibits characteristic 4F3/2 → 4IJ/2 (J = 9, 11, 13) transition NIR emission. 1-Eu and 4-Eu provide characteristic 5D0 → 7FJ intense and bright red luminescence, while 4-Eu exhibits better luminescence performance because of the presence of the O-H oscillators within 1-Eu. 6-Tb exhibits characteristic 5D4 → 7FJ intense and bright green luminescence. Furthermore, through doping with PMMA polymer, the luminescence properties of 4-Eu and 6-Tb are all improved. The results show the best doping concentration is 4%. The thermal stabilities of 4-Eu-PMMA and 6-Tb-PMMA increased from 270 to 315 °C when compared with single coordination polymers 4-Eu and 6-Tb. The co-doping of 4-Eu, 5-Gd, and 6-Tb (0.92/0.04/0.04) with PMMA at a total concentration of 4% resulted in a tunable luminescence material W(4-Eu,5-Gd,6-Tb)-PMMA film. When excited at 285 nm, W(4-Eu,5-Gd,6-Tb)-PMMA shows white-light emission with the CIE chromaticity coordinates of (0.33, 0.35). The lifetime of Eu3+ ions in W(4-Eu,5-Gd,6-Tb)-PMMA increased from 1032.24 µs to 1272.26 µs when compared with 4-Eu-PMMA, and the efficiency of energy transfer (ηET) from Tb3+ to Eu3+ within the co-doping PMMA film could be estimated to be 29.9%.

19.
Dalton Trans ; 46(4): 1266-1276, 2017 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-28067376

RESUMO

A series of Zn(ii) complexes with different conjugated systems, [ZnL1Cl2]2 (Zn1), [ZnL2Cl2] (Zn2), [Zn(L3)2]·(ClO4)2 (Zn3), [Zn2L4Cl4] (Zn4), and [ZnL5Cl2] (Zn5), were synthesized and subsequently characterized via single crystal X-ray diffraction, 1H and 13C NMR, FT-IR, elemental analyses, melting point, and PXRD. The X-ray diffraction analyses revealed that the supramolecular frameworks of complexes Zn1-Zn5 are constructed by C-HO/Cl hydrogen bonds and ππ interactions. Complexes Zn1-Zn3 feature 3D 6-connected {412·63} topological structures, whereas complex Zn4 exhibits a 3D 7-connected supramolecular framework with a {417·64} topological structure. However, complex Zn5 shows one-dimensional "wave-like" chains. Based on these varied structures, the emission maximum wavelengths of complexes Zn1-Zn5 can be tuned in a wide range of 461-592 nm due to the red shift direction of λem caused by different conjugated systems and their electron donating abilities. Complex Zn3 shows a strong luminescence in the solid state and in the acetonitrile solution. Therefore, a series of Zn3-poly(methylmethacrylate) (Zn3-PMMA) hybrid materials were obtained by controlling the concentration of complex Zn3 in poly(methylmethacrylate) (PMMA). At an optimal concentration of 4%, the doped polymer film of Zn3-PMMA displays strong green luminescence emissions that are 19-fold in the luminescence intensities and 98 °C higher in the thermal stability temperature compared to the Zn3 film.

20.
Dalton Trans ; 46(1): 71-85, 2016 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-27897300

RESUMO

Judicious structural design employing 2-quinolinecarboxaldehyde and 4-methylaniline was used to generate the Schiff base ligand (E)-4-methyl-N-((quinolin-2-yl)ethylidene)aniline (L). Five IIB complexes, namely, [ZnLCl2] (1), [ZnL(NO3)2] (2), [ZnL(OAc)2]3 (3), [CdL(OAc)2]3 (4), and [HgLCl2] (5) have been synthesized based on L. Single-crystal X-ray diffraction analysis indicates that complexes 1, 3 and 4 exhibit 3D networks, whereas 2 and 5 form 2D layers and 1D chains, respectively. TD-DFT calculations show a good correlation with the UV-vis absorption assigned to π → π* intraligand transitions. Furthermore, complexes 1-5 displayed strong greenish luminescent emissions (518-524 nm) in the aggregate state but weak emissions in solution (aggregation-induced emission enhancement), which may be due to the existence of C-HCl/O hydrogen bonding and ππ stacking interactions, resulting in restriction of intramolecular rotation (RIR). Variable-concentration 1H NMR studies suggested that the aggregates undergo intramolecular changes in conformation due to intermolecular interactions. Moreover, the emission intensity and lifetime exhibited obvious increases induced by mechanical grinding and temperature reduction, which were also attributed to AIEE properties. Subsequently, complex 1 was incorporated into poly(methyl methacrylate) (PMMA), whereby 1-PMMA exhibited enhanced emission intensity (20-fold increase in comparison with that of 1), which offers opportunities for use in plastic greenhouses to increase leaf photosynthesis.

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