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1.
Food Chem ; 302: 125331, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31404867

RESUMO

Adulteration of the high-value silver pomfret (Pampus argenteus) is a serious problem worldwide, necessitating accurate identification and quantification of the species. In this study, optimisation of the digital droplet PCR (ddPCR) assay for the identification and quantification of the silver pomfret was carried out. The primer and probe concentrations, melting temperature, and PCR cycle number were optimised by combining single-factor experiments with an orthogonal experimental design. The absolute limits of detection and quantification of the ddPCR were 2copies/µl and 21 copies/µl, respectively. Its sensitivity was 0.1% for meat mixtures and 0.5% for DNA mixtures. The ddPCR was 156 times more sensitive than the real-time PCR, although both methods had similar specificities. However, the overall time needed to complete the ddPCR method was twice that of the real-time PCR. Notwithstanding, the ddPCR methodology established in this study can be a valuable tool for addressing species adulteration issues.

2.
Methods Mol Biol ; 2046: 17-29, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31407293

RESUMO

Microbiomes on Earth are often considered the most heterogeneous biological entities, but their vital roles in driving global biogeochemical cycles often remain elusive. DNA-based stable isotope probing (DNA-SIP) provides a powerful means to establish a direct link between biogeochemical processes and the taxonomic identities of active microorganisms involved in the processes. Combined with high-throughput sequencing, it significantly aids in deciphering ecophysiological functions of active microorganisms at the level of microbial communities. DNA-SIP relies solely on the propagation of targeted microbial communities, during which the entire genomes of daughter cells are synthesized and increasingly 13C-labeled. This growth on 13C-labeled substrate in association with cell division provides solid evidence for the functional importance and metabolic potential of targeted microorganisms. The essential prerequisite for a successful DNA-SIP experiment is the identification, with confidence, of isotopically enriched 13C-DNA, of which the amount is generally too low to allow for the direct measurement of 13C atomic percent of nucleic acid. The 13C labeling can be readily identified in the fractionated DNA by quantification of functional genes specific to the known targeted microorganisms, and by high-throughput sequencing of the total microbial communities via 16S rRNA genes without prior knowledge of which microorganisms are 13C-labeled (i.e., highly enriched in the heavy fractions relative to 12C (natural isotope abundance) control treatments). In this chapter, the protocol for obtaining DNA highly enriched in heavy isotope is presented using diazotrophic methanotrophs in a paddy soil as a case study.

3.
Fitoterapia ; 138: 104299, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31404616

RESUMO

Gerbera piloselloides (L.) Cass. (Compositae) possesses various biological effects. It is used as an oriental remedy for relieving cough and resolving phlegm. The present study is to investigate the vasodilation effects of Gerbera piloselloides on isolated rat mesenteric arteries (MAs) and the potential mechanism. Different organic extracts of Gerbera piloselloides were tested, and an HPLC-UV-FD-based analytical method was established to identify the active constituents. The principal components, namely, 8-MOP (8-methoxypsoralan) and 8-MSD (8-methoxysmyrindiol), were found to be predominant in the extracts of petroleum ether and dichloroform, which showed stronger vasodilation activities. 8-MSD was isolated from Gerbera piloselloides by silica gel column chromatography coupled with a Waters 2545 high throughput autopurification system, and its vasodilation effects were explored by an assay of tension on rat MA rings. The results suggest that 8-MSD induces vascular relaxation in rat MAs via an endothelium-dependent mechanism involving the Kir channel, which enables Ca2+ entry in the cell and activates production of NO. The present research indicates that 8-MSD may be therapeutically useful as an anti-hypertension agent and to potentially treat cardiovascular and gastrointestinal diseases.

4.
Inorg Chem ; 58(16): 10974-10982, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31348652

RESUMO

Highly positive temperature coefficients of the resonant frequency (τf) of eight-layer hexagonal perovskites are hardly tunable, hindering their application as microwave dielectric resonators. Here, we show that a near-zero τf (∼0.48 ppm °C-1) can be achieved on eight-layer shifted hexagonal perovskite Ba8CoNb4Ta2O24, along with a permittivity εr of ∼30.6 and a Qf of ∼36400 GHz, through substitution of Ta for Nb, satisfying the resonator application requirement. The decrease in the τf of Ba8CoNb6-xTaxO24 takes place mainly through the decrease in the εr or temperature coefficient of permittivity, owing to the less covalent bonding and lower polarizability of Ta5+ compared to those of Nb5+. Synchrotron and neutron powder diffraction data, scanning transmission electron microscopy-high-angle annular dark field imaging, and atomic-scale X-ray energy dispersive spectroscopy elemental mapping reveal that Ta5+ cations in Ba8CoNb4Ta2O24 are naturally distributed in a partially ordered manner, showing a strong site preference on the Nb layers close to the central Co layer over the most out-of-center distorted Nb layers next to empty octahedral layers. This spontaneous Ta ordering in the niobate host is driven by different covalent bonding nature and second-order Jahn-Teller distortion extents of Ta5+ and Nb5+. The results demonstrate an effective way of substituting more ionic Ta5+ for Nb5+, which decreases the τf to near-zero values for eight-layer hexagonal perovskite niobate dielectrics.

5.
Molecules ; 24(9)2019 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-31035631

RESUMO

P-glycoprotein (P-gp) serves as a therapeutic target for the development of inhibitors to overcome multidrug resistance (MDR) in cancer cells. In order to enhance the uptake of chemotherapy drugs, larger amounts of P-gp inhibitors are required. Besides several chemically synthesized P-gp inhibitors, flavonoids as P-gp inhibitors are being investigated, with their advantages including abundance in our daily diet and a low toxicity. The cytotoxicity of daunorubicin (as a substrate of P-gp) to KB/MDR1 cells and the parental KB cells was measured in the presence or absence of flavonoids. A two-dimensional quantitative structure-activity relationship (2D-QSAR) model was built with a high cross-validation coefficient (Q2) value of 0.829. Descriptors including vsurf_DW23, E_sol, Dipole and vsurf_G were determined to be related to the inhibitory activity of flavonoids. The lack of 2,3-double bond, 3'-OH, 4'-OH and the increased number of methoxylated substitutions were shown to be beneficial for the inhibition of P-gp. These results are important for the screening of flavonoids for inhibitory activity on P-gp.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Flavonoides/química , Flavonoides/farmacologia , Relação Quantitativa Estrutura-Atividade , Sobrevivência Celular , Relação Dose-Resposta a Droga , Humanos , Células KB , Modelos Moleculares , Conformação Molecular , Ligação Proteica
6.
Biofactors ; 45(4): 563-574, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31131946

RESUMO

Isoflavones are one group of the major flavonoids and possess multiple biological activities due to their antioxidant properties. However, a clear antioxidant mechanism of dietary isoflavones is still remained to be answered. In this study, the effects of isoflavones on the nuclear factor E2-related factor 2 (Nrf2)-antioxidant response element (ARE) signaling pathway and the underlying molecular mechanisms were investigated. Results showed that isoflavones are potential Nrf2-ARE activators while their activities were structure dependent. Biochanin A (BCA), an O-methylated isoflavone with low direct antioxidant activity, can effectively protect HepG2 cells against tert-butyl hydroperoxide (t-BHP)-induced oxidative damage via activation of the Nrf2 signaling, and thereby the induction of downstream cytoprotective enzymes including NAD(P)H quinone oxidoreductase-1, heme oxygenasae-1, and glutamate-cysteine ligase catalytic subunit. A molecular docking study revealed that BCA could directly bind into the pocket of Kelch-like erythroid cell-derived protein with CNC homology (ECH)-associated protein 1 (Keap1), a cytoplasmic suppressor of Nrf2, to facilitate Nrf2 activation. The upstream mitogen-activated protein kinase (MAPK) pathways were also involved in the activation of Nrf2 signaling. These findings indicate that the protective actions of dietary isoflavones against oxidative damage may be at least partly due to their ability to enhance the intracellular antioxidant response system by modulating the Nrf2-ARE signaling pathway.

7.
Food Chem ; 291: 101-109, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31006447

RESUMO

This study was aimed to determine the relationship of flavonoid structures to their affinity for an important efflux transporter, multidrug-resistant associated protein 2 (MRP2). The cellular uptake (CU) of 35 flavonoids was investigated in MRP2 overexpression MDCK/MRP2 cells. Resulting data identified 8 flavonoids as MRP2 substrates based on their high CUMK with MK-571 in MDCK/MRP2 cells. Also, three substrates showed better CUMD in MDCK cells than did CUMRP in MDCK/MRP2 cells. Docking analyses showed a good correlation (R = 0.926, p = 0.003) between efflux-fold of flavonoid substrates and their docking S_scoring with the MRP2 model, indicating consistency between in silico and in vitro approaches. A structure affinity relationship (SAR) study indicated that 3-OH, 5-OH, 6-OH, 3'-OH, and 4'-OCH3 substituents were favourable while, 8-OCH3, 2'-OH, 3'-OCH3, 4'-OH and 5'-OH were unfavourable for flavonoid affinity to MRP2. Our study provides valuable information for dietary application of flavonoids with specific structures for high absorption.


Assuntos
Flavonoides/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Animais , Sítios de Ligação , Sobrevivência Celular/efeitos dos fármacos , Cães , Flavonoides/química , Flavonoides/farmacologia , Ligações de Hidrogênio , Células Madin Darby de Rim Canino , Simulação de Acoplamento Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Estrutura Terciária de Proteína , Especificidade por Substrato
8.
J Mater Sci Mater Med ; 30(4): 41, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30919092

RESUMO

For cartilage tissue repairing, it remains a key challenge to design implant materials with antibacterial activity, proper degradation rate and mechanical property. In this research, antibacterial nanodiamonds (QND, QND-Ag) modified acrylate-terminated polyurethanes (APU) were prepared. By the addition of nanocomposites, the crystallinity of modified APU obviously increased, which indicates a strong interaction between NDs and APU. Tensile and compression tests were carried out to evaluate the improved mechanical properties. Compared with APU, APU(10%PEG)/QND-Ag possessed the increased modulus and strength, a nevertheless slight decrease in elongation at break. Due to the dual actions of contact-killing of cationic polymers and release-killing of the Ag NPs, QND-Ag-containing polyurethane showed excellent antibacterial activity against Staphylococcus aureus. Moreover, APU containing polyethylene glycol showed a significant increase in degradability rates. Consequently, owing to the dual effect of crystallinity and hydrophilicity, our modified APU exhibited the proper degradation rate adaptable to the healing rate of cartilage tissue. Furthermore, the CCK-8 results demonstrated that synthesized samples were low toxic. Therefore, APU(10%PEG)/QND-Ag holds great promise for the application of cartilage tissue repairing.


Assuntos
Antibacterianos , Cartilagem , Regeneração Tecidual Guiada , Nanodiamantes/química , Poliuretanos/química , Prata/administração & dosagem , Tecidos Suporte/química , Implantes Absorvíveis , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Fenômenos Biomecânicos , Cartilagem/citologia , Cartilagem/efeitos dos fármacos , Cartilagem/fisiologia , Células Cultivadas , Preparações de Ação Retardada , Portadores de Fármacos/química , Regeneração Tecidual Guiada/instrumentação , Regeneração Tecidual Guiada/métodos , Teste de Materiais , Camundongos , Testes de Sensibilidade Microbiana , Poliaminas , Regeneração/efeitos dos fármacos , Prata/farmacocinética , Staphylococcus aureus , Estresse Mecânico , Cicatrização/efeitos dos fármacos
9.
J Agric Food Chem ; 67(8): 2350-2360, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30688455

RESUMO

This study was aimed to determine the mechanism for flavonoid poor absorption related to P-glycoprotein (P-gp). The cellular uptake (CU) of 40 flavonoids was investigated in P-gp overexpressing KB/multidrug-resistant (MDR) cells. A total of 9 flavonoids, including 5,7,3',4'-tetramethoxyflavone, with a significant ( p < 0.05) CUKBE (2.90 ± 0.146 µmol/g) higher than CUKBP (1.57 ± 0.129 µmol/g) were identified as P-gp substrates. Besides, 8 substrates, including tangeretin, showed a significant ( p < 0.05) CUKB (9.72 ± 1.09 µmol/g) higher than its CUKBP (7.36 ± 0.692 µmol/g). A total of 7 of 17 flavonoid substrates stimulated the P-gp efflux of rhodamine 123, and most substrates increased P-gp expression in KB/MDR cells. Docking analyses showed a good correlation ( R = 0.764; p < 0.01) between efflux fold and S_scoring of flavonoids to the P-gp model, indicating consistency between in silico and in vitro results. A structure-affinity relationship exhibited that 3-OH, 5-OH, 3'-OCH3, and 4'-OCH3 are crucial for flavonoids binding to P-gp. These results provide valuable information for finding a solution to improve the absorption of flavonoids.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Carcinoma/metabolismo , Flavonoides/metabolismo , Expressão Gênica , Neoplasias Bucais/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Transporte Biológico , Carcinoma/genética , Linhagem Celular Tumoral , Flavonoides/química , Corantes Fluorescentes/metabolismo , Humanos , Simulação de Acoplamento Molecular , Neoplasias Bucais/genética , Rodamina 123/metabolismo
10.
Nanomedicine ; 2018 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-30326275

RESUMO

Development of combined chemo-photothermal nanoplatform is of great interest for enhancing antitumor efficacy. Herein, a multifunctional drug delivery system was synthesized based on gold-nanobranched coated betulinic acid liposomes (GNBS-BA-Lips) for chemo-photothermal synergistic therapy. In this system, GNBS-BA-Lips exhibited broad near-infrared (NIR) absorption, preferable photothermal response and good photostability under NIR irradiation. Importantly, the gold-nanobranched nanostructure possessed high photothermal conversion efficiency (η = 55.7%), and the temperature change (ΔT) reached 43.2 °C after laser irradiation for 5 min. Upon NIR irradiation, the nanocarriers apparently endowed higher cell uptake, resulting in an enhanced intracellular drug accumulation. Furthermore, the tumor growth inhibition ratio achieved from chemo-photothermal therapy of GNBS-BA-Lips was 86.9 ±â€¯1.1%, which was higher than that of the chemotherapy or photothermal therapy alone, showing an outstanding synergistic anticancer effect. Our data suggested that the nanoplatform should be considered as a critical platform in the development of cancer multi-mode therapies.

11.
Nanomedicine ; 15(1): 142-152, 2018 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-30300749

RESUMO

A multifunctional antitumor drug delivery system was synthesized based on graphene oxide (GO) for near-infrared (NIR) light controlling chemotherapeutic/photothermal (PTT) /photodynamic (PDT) trimodal synergistic therapy. The system named ICG-Wed-GO was formed by co-loading wedelolactone (Wed) and indocyanine green (ICG) on the surface of GO through π-π stacking interaction. Under NIR laser irradiation, ICG-Wed-GO could effectively absorb and transform optical energy to heat, generate reactive oxygen species (ROS) to ablating and damage tumor cells. The temperature of ICG-Wed-GO solution reached up to 79.4 °C in 10 min with NIR irradiation. In in vitro and in vivo study, ICG-Wed-GO showed excellent antitumor effect. After 14-day treatment of ICG-Wed-GO with NIR laser irradiation, the tumor disappeared completely on tumor-bearing mice. The low biotoxicity of ICG-Wed-GO was also proved. The system achieved the synergistic trimodal chemotherapeutic/photothermal/photodynamic treatment and demonstrated excellent antitumor effect, which is expected to have a greater potential for cancer therapy.

12.
J Mater Sci Mater Med ; 29(11): 162, 2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30357538

RESUMO

There is an increasing clinical need to design dental restorative materials that combine excellent mechanical property and anti-biofilm activity. In the current study, photocurable polycation functionalized nanodiamond (QND) was synthesized and proposed as novel filler for dental resins. By reason of increased repulsive force between nanoparticles and enhanced compatibility with resin matrix, QND dispersed uniformly in reinforced resins, which would help to transfer stress and deformation from the matrix to fillers more efficiently, resulting in a significant improvement in mechanical properties. Notably, the Vickers's hardness, flexural strength and flexural modulus of resins containing 1.0 wt% QND were 44.5, 36.1 and 41.3% higher than that of control, respectively. The antibacterial activity against Streptococcus mutans (S. mutans) showed that QND-incorporated resins produced anti-adhesive property due to their hydrophilic surfaces and could suppress bacterial growth as a result of the contact-killing effect of embedded nanocomposites. As the synergistic effect of anti-adhesive and bactericidal performance, resins loading 1.0~1.5 wt% QNDs displayed excellent anti-biofilm activity. Meanwhile, the results of macrophage cytotoxicity showed that the proliferation of RAW 264.7 cells remained 84.3%, even at a concentration of 1.0 wt% QNDs after 7-day incubation. Therefore, the QND-containing dental resin with the combination of high mechanical property, bacteria-repellent capability and antibacterial performance holds great potential as a restorative material based on this scheme.

13.
Mater Sci Eng C Mater Biol Appl ; 92: 307-316, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30184755

RESUMO

Designing cationic nano-antimicrobial is a promising solution for combating drug resistant microbes. In this work, hydrophilic cationic copolymer was applied for the surface functionalization of nanodiamonds (NDs) aiming at developing a highly membrane-active nano-antibacterial agent with satisfactory selectivity. As a result, after functionalization, the increased repulsive forces within NDs and interaction with solvent molecular network made the heavily aggregated pristine NDs break down into tiny nanoparticles with particle size ranging from 10 to 100 nm. The improved hydrophilicity and enlarged surface area endowed QND-H5 and QND-H10 a powerful bactericidal capability toward both of Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). In the further bactericidal assessment, it was also demonstrated that the formation of hydrogen bonding between the 2-hydroxyethyl methacrylate (HEMA) side chains and lipid head groups of bacterial membrane also contributed to the enhanced bactericidal ability. Field emission scanning electron microscopy analysis confirmed that as-prepared nano-hybrid acted bactericidal ability via physical nature of outer membrane and cytoplasmic membrane-separating destruction mechanism toward E. coli, which may derive from the hydrogen bonding ability, making them more effective toward bacterial. More importantly, it was found that with just 10% of HEMA, QND-H10 displayed good selectivity toward bacteria over mammalian cells as shown by the high HC50 values with relatively low MIC values, suggesting the great potential application in medical fields. These results indicate that hydrogen bonding is an important element to achieve the desired high antibacterial activity and selectivity, particularly when cationic nano-antibacterial agents are required for medical application.

14.
Artigo em Inglês | MEDLINE | ID: mdl-30103928

RESUMO

We have previously shown that 15-lipoxygenase (15-LOX) and its metabolite 15-hydroxyeicosanoid (15-HETE) play a critical role on hypoxia-triggered pulmonary artery smooth muscle cell (PASMC) phenotype alteration through multifactorial pathways, like extracellular signal-regulated kinase and p38 mitogen-activated protein kinases. Here, we hypothesize that activator protein 1 (AP-1) was also involved in the PASMC phenotype alteration. Hypoxia elevated AP-1 expression in pulmonary arterials and in cultured PASMCs with a time-dependent manner. Both the gene disruption and pharmacological inactivation of 15-lipoxygenase (15-LOX) significantly attenuated the hypoxia-elevated AP-1 expression. Silencing of AP-1 with small interference RNA abrogated the hypoxia- and 15-HETE-increased cell viability, proliferating cell nuclear antigen expression, and Ki67 and α-tubulin staining. Moreover, AP-1 knockdown prevented hypoxia- and 15-HETE-promoted cyclin D1 expression and subsequent cell cycle progression into G2/M+S phase. Interestingly, AP-1 knockdown also inhibited the expression of 15-LOX, indicating a feedback regulation of 15-LOX/15-HETE signaling by AP-1. These findings shed light on the involvement of AP-1 in the PASMCs phenotype alteration via the hypoxia/15-LOX/15-HETE signaling.

15.
Nanotechnology ; 29(40): 405101, 2018 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-30004030

RESUMO

Hybrid liposome/metal nanoparticles are promising candidate drug-carriers for therapy of various diseases due to their unique photothermal effect. In this study, self-crystallized gold nanoparticles (Au NPs) and doxorubicin (DOX) were co-encapsulated within liposomes (Au/DOX-Lips) by thin film hydration and gel separation technology. The surface plasmon resonance bands of drug-carriers were controllable in the near-infrared (NIR) zone. When the complex liposome/metallic hybrids were irradiated by NIR light, they displayed higher endocytosis efficiency following the fracture of liposomal membranes and the release of Au NPs. Then, the Au NPs penetrated further into deeper tumor tissue to accomplish photothermal treatment. The Au/DOX-Lips showed an excellent antitumor effect, whose inhibition rate for tumor cells was up to 78.28%. In experiments on mice bearing tumors, the Au/DOX-Lips treated mice exhibited superior tumor suppression. This novel drug system provides huge potential for biomedical application.


Assuntos
Doxorrubicina/administração & dosagem , Ouro/administração & dosagem , Hipertermia Induzida/métodos , Neoplasias Experimentais/terapia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Terapia Combinada , Doxorrubicina/farmacologia , Ouro/farmacologia , Células HeLa , Humanos , Lipossomos/química , Nanopartículas Metálicas/química , Camundongos , Fotoquimioterapia , Ensaios Antitumorais Modelo de Xenoenxerto
16.
J Agric Food Chem ; 66(25): 6317-6325, 2018 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-29871486

RESUMO

The current study evaluates the protective effects of tangeretin, a representative polymethoxyflavone (PMF) mainly isolated from the peels of citrus fruits, against tert-butyl hydroperoxide ( t-BHP)-induced oxidative damage in HepG2 cells and the potential mechanisms of this protection. Tangeretin suppressed t-BHP-induced oxidative damage, as evaluated by cell viability, reactive-oxygen-species (ROS) levels, lactate dehydrogenase (LDH) leakage and glutathione (GSH) levels. Further mechanistic studies showed that tangeretin up-regulated the expression of heme oxygenase 1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). Moreover, tangeretin induced antioxidant-responsive-element (ARE)-dependent luciferase activation, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nuclear translocation, and mitogen-activated-protein-kinase (MAPK) phosphorylation. Results in the study indicate that the protective effects of tangeretin may be at least partly due to its capacity to up-regulate the antioxidant enzymes NQO1 and HO-1 via the MAPK-Nrf2-ARE signaling pathway. Tangeretin may play an effective protective role in liver injury.


Assuntos
Elementos de Resposta Antioxidante/efeitos dos fármacos , Flavonas/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , terc-Butil Hidroperóxido/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glutationa/metabolismo , Células Hep G2 , Humanos , Fator 2 Relacionado a NF-E2/genética , Espécies Reativas de Oxigênio/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-29744521

RESUMO

Soil heavy metal pollution has received increasing attention due to their toxicity to soil microorganisms. We have analyzed the effects of heavy metal pollution on ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in soils in the vicinity of a tailings dam of Baotou region, China. Results showed that AOB were dominated with Nitrosomonas-like clusters, while AOA was dominated by group1.1b (Nitrososphaera cluster). Single Cd and Cr contents, as well as compound heavy metal pollution levels, had a significant negative impact on soil potential nitrification rate and both diversities of AOA and AOB. No clear relationship was found between any single heavy metal and abundance of AOA or AOB. But compound pollution could significantly decrease AOA abundance. The results indicated that heavy metal pollution had an obviously deleterious effect on the abundance, diversity, activity and composition of ammonia oxidizers in natural soils.

18.
BMC Infect Dis ; 18(1): 145, 2018 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-29606088

RESUMO

BACKGROUND: Human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and Treponema pallidum (TP) infections are considered classic transfusion-transmissible infections (TTIs). Few data are available about the prevalence of TTIs in patients before blood transfusion in China. This study aimed to investigate the seroprevalence of four TTIs among patients before blood transfusion in Xiangya Hospital Central South University, China. METHODS: From 2011 to 2016, 442,121 hospitalized patients before possible blood transfusion were tested for hepatitis B surface antigen (HBsAg), anti-HCV, syphilis antibody (anti-TP) and anti-HIV. RESULTS: Of the 442,121 patients, the overall positivity of the four TTI serum markers was 15.35%. The positive rates of HBsAg, anti-HCV, anti-HIV and anti-TP were 10.98, 1.43, 0.16 and 2.78%, respectively. TTI serum markers showed a significant difference by gender, with positive rates of 17.98% for males and 12.79% for females. The prevalence of TTI serum markers varied significantly by age. The overall co-infection rate was 0.63%, and the top three multiple infections were HBV-TP, HBV-HCV, and HCV-TP. The co-infection rates of HBV-TP and HBV-HCV showed a significant decrease from 2011 to 2016, while the rates of other co-infections remained stable. CONCLUSIONS: The prevalence of TTIs in patients before blood transfusion is much higher compared to that in blood donors in the region. The infection rates of HIV and TP increased, and the infection rate of HBsAg decreased in recent years.


Assuntos
Transfusão de Sangue/estatística & dados numéricos , Infecções por HIV/epidemiologia , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Hospitalização/estatística & dados numéricos , Sífilis/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Doadores de Sangue , Criança , Pré-Escolar , China/epidemiologia , Coinfecção/epidemiologia , Estudos Transversais , Feminino , Infecções por HIV/sangue , Hepacivirus/imunologia , Hepacivirus/isolamento & purificação , Hepatite B/sangue , Vírus da Hepatite B/imunologia , Vírus da Hepatite B/isolamento & purificação , Hepatite C/sangue , Hospitais de Ensino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Sífilis/sangue , Treponema pallidum/imunologia , Treponema pallidum/isolamento & purificação , Adulto Jovem
19.
Inorg Chem ; 57(7): 4117-4124, 2018 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-29553259

RESUMO

Isovalent substitution of Zr4+ for smaller Ti4+ was performed in the 8-layer twinned hexagonal perovskite (referred to as 8H) tantalate Ba8Ti3Ta4O24, which stabilizes a 10-layer twinned hexagonal perovskite (referred to as 10H). The formation of the 10H phase occurs at low substitution concentration ( x = 0.1) in Ba8Zr xTi3- xTa4O24 at 1300 °C and reverts back to the 8H phase upon heating at elevated temperatures. Such a 10H-to-8H phase transformation is suppressed at higher Zr-substitution contents ( x > 0.1). The approach combining simulated annealing and Rietveld refinement with compositional constrain indicates that the 10H Ba8Zr0.4Ti2.6Ta4O24 ( x = 0.4) composition adopts a simply P63/ mmc disordered structure with Zr cations preferably located in corner-sharing octahedral (CSO) sites compared to face-sharing octahedral (FSO) sites. This 8H-10H phase competition, dependent on the substitution of Zr4+ for Ti4+ and firing temperature, is discussed in terms of the FSO B-B repulsion controlled by the cationic size, as well as the stacking periodicity which affects the thermodynamic stability. Both 8H- and 10H-phase pellets of Ba8Zr xTi3- xTa4O24 exhibit comparable and poorer microwave dielectric properties than the parent 8H Ba8Ti3Ta4O24, which is characterized by cationic disorder and FSO B-B repulsion. The 8H and 10H Ba8Zr xTi3- xTa4O24 ceramics display electrical insulator behavior but with electrically heterogeneous microstructure on the bulk grains. This study demonstrates the opportunity to control the stacking periodicity for the twinned hexagonal perovskites via tuning the B-cationic size and the firing temperature.

20.
J Fluoresc ; 28(2): 561-572, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29560601

RESUMO

Significant autofluorescence (AF) of renal tissue is one of the major causes restricting the use of immunofluorescent staining. This study aimed at controlling renal tissue AF and testing an effective method for optimizing specific signals. In the present study, we observed emergence of strong AF in all renal cells under different fluorescent channels. Significant concentration-dependent reduction in AF of kidney tissue was observed with the use of sodium borohydride (NaBH4) and Sudan black B (SBB) alone (p < 0.05). Under maximum effective concentration, semi-quantitative analysis revealed that inhibitory effect of SBB on AF was superior to that of NaBH4 (P < 0.01). When the two chemicals were combined, we observed that background can be reduced, and specific staining can be optimized at optimum concentration. Intensity of renal tissue was examined by confocal λ scanning, which showed that peaks were located at the range of approximately 480 - 590 nm and similar to those of flavin and lipofuscin. These results indicated that combined use of NaBH4 and SBB, when targeted at different sources of AF in renal tissue, is the most effective means of reducing background and preserving specificity of fluorescent labels. In addition, this method does not interfere with various steps of immunofluorescence experiments.


Assuntos
Fluorescência , Rim/metabolismo , Microscopia Confocal/métodos , Animais , Artefatos , Compostos Azo/metabolismo , Boroidretos/metabolismo , Feminino , Rim/citologia , Naftalenos/metabolismo , Ratos , Ratos Sprague-Dawley
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