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1.
Neurosci Lett ; 751: 135830, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33722543

RESUMO

ErbB4 loss-of-function in catecholaminergic neurons induces catecholamine dyshomeostasis. Despite ErbB4's significant role in neuropathology, the signaling pathways that regulate these changes are still widely unknown. In this study, we attempt to identify the downstream pathway of ErbB4 that regulates catecholamine homeostasis. The SH-SY5Y human neuroblastoma cell line was used as the in vitro model for catecholaminergic neurons. Western blotting, enzyme-linked immunosorbent assay, and pharmacological and genetic manipulations by agonist/antagonist or small interference RNA were used to investigate the relationship between ErbB4 and extracellular catecholamines. We confirmed that ErbB4 is abundantly expressed in undifferentiated and retinoic acid-differentiated catecholaminergic cells from the SH-SY5Y cell line. ErbB4 inhibition increase the ratio of phosphorylated p38 to total p38 in SH-SY5Y human neuroblastoma cells. Consistent with previous in vivo observations in mice, ErbB4 deficiency led to increases in extracellular dopamine and norepinephrine levels. However, the resulting increase in extracellular dopamine, but not norepinephrine, could be suppressed by p38 inhibitor SB202190. Our results suggest that both extracellular dopamine and norepinephrine homeostasis could be regulated by ErbB4 in human catecholaminergic cells, and ErbB4 may regulate extracellular dopamine, but not norepinephrine, through the p38 MAPK signaling pathway, thus indicating different regulatory pathways of dopamine and norepinephrine by ErbB4 in catecholaminergic neurons.


Assuntos
Dopamina/metabolismo , Sistema de Sinalização das MAP Quinases , Receptor ErbB-4/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Linhagem Celular Tumoral , Células Cultivadas , Espaço Extracelular/metabolismo , Humanos , Camundongos , Neurônios/metabolismo , Norepinefrina/metabolismo , Receptor ErbB-4/genética
2.
Huan Jing Ke Xue ; 41(3): 1377-1383, 2020 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608639

RESUMO

Partial-denitrification coupled with ANAMMOX is a novel biological nitrogen removal technology, which is expected to significantly reduce the external carbon source dosage for advanced nitrogen removal from municipal wastewater. In this study, ANAMMOX sludge was inoculated to investigate advanced nitrogen removal performance and sludge characteristics in a partial-denitrification/ANAMMOX reactor. The results showed that inoculation of ANAMMOX sludge could quickly start the partial-denitrification/ANAMMOX reactor. The effluent total nitrogen concentrations were (4.82±1.84) mg·L-1 with a chemical oxygen demand of 2.19±0.08. Sludge particles larger than 0.20 mm accounted for 86.16% in the reactor. This meant that granular sludge was formed, which was conducive to good retention of ANAMMOX bacteria in the reactor. The external carbon source dosage and the oxygen requirement for nitrification can be reduced by applying partial-denitrification coupled with ANAMMOX to advanced nitrogen removal from the effluent of secondary clarifier in municipal wastewater treatment plants.

3.
Phys Chem Chem Phys ; 22(30): 17229-17235, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32685948

RESUMO

Compared with the conventional magnetic means (such as ferromagnetic contacts), controlling a spin current by electrical methods could largely reduce the energy consumption and dimensions of nano-devices, which has become a focus of research in spintronics. Inspired by recent progress in the synthesis of an iron-based metal-organic nanostructure, we investigate the spin-dependent electronic transport of the molecule of Fe3-terpyridine-phenyl-phenyl-terpyridine-Fe3 (Fe3-TPPT-Fe3) through first-principles calculations, and propose a three-terminal device without ferromagnetics. By applying a gate voltage, not only the spin polarization can be switched between 100% and -100% to achieve a dual-spin filter, but also its fine regulation can be realized, where the transmission with any ratio of spin-up to spin-down electron numbers is achievable. Analysis shows that the particular transmission spectra are the key mechanism, where two peaks reside discretely on both sides of the Fermi level with opposite spins. Such a feature is found to be robust to the number of Fe atoms and TPPT chain length, suggesting that it is an intrinsic feature of such systems and very conducive to practical applications. The electrical control (such as an electric field) of spin polarization is realized at the single-molecule level, showing great application potential.

4.
FASEB J ; 34(1): 446-457, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31914682

RESUMO

Mechanical damage or infection to the endometrium can lead to the formation of adhesions in the uterine cavity, which may result in reduced reproductive outcome and/or pregnancy complications. The prognosis of this disease is poor due to few effective treatments and the complex environment of endometrium. Heparin-Poloxamer Hydrogel (HP hydrogel) is a nontoxic and biodegradable biomaterial, which has been commonly used as a sustained-release delivery system. In this study, we applied a mini-endometrial curette to scrape the endometrium of rats to mimic the process of curettage in patients. After the establishment of IUA model in rats, we injected the thermo-sensitive hydrogel(E2-HP hydrogel) into the injured uterine cavity and evaluated the therapeutic effect of E2-HP hydrogel on the recovery of IUA. Our results showed that E2-HP hydrogel can significantly facilitate the regeneration of injured endometrium along with inhibiting the cell apoptosis in IUA model. Furthermore, we revealed that E2-HP hydrogel on the recovery of IUA was closely associated with the upregulation of kisspeptin through activating the ERK1/2 and MAPKs p38 pathways. In conclusion, E2-HP hydrogel can effectively transfer E2 into the injured endometrium and it can be considered as a promising therapeutic method for the women with intrauterine adhesions.


Assuntos
Endométrio/citologia , Estradiol/farmacologia , Heparina/química , Hidrogéis/farmacologia , Poloxâmero/química , Regeneração , Aderências Teciduais/tratamento farmacológico , Útero/citologia , Animais , Endométrio/efeitos dos fármacos , Endométrio/lesões , Estradiol/química , Feminino , Hidrogéis/química , Gravidez , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Útero/efeitos dos fármacos , Útero/lesões
5.
Nat Commun ; 10(1): 1813, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-31000718

RESUMO

The asparagine (N)-linked Man9GlcNAc2 is required for glycoprotein folding and secretion. Understanding how its structure contributes to these functions has been stymied by our inability to produce this glycan as a homogenous structure of sufficient quantities for study. Here, we report the high yield chemoenzymatic synthesis of Man9GlcNAc2 and its biosynthetic intermediates by reconstituting the eukaryotic lipid-linked oligosaccharide (LLO) pathway. Endoplasmic reticulum mannosyltransferases (MTases) are expressed in E. coli and used for mannosylation of the dolichol mimic, phytanyl pyrophosphate GlcNAc2. These recombinant MTases recognize unique substrates and when combined, synthesize end products that precisely mimic those in vivo, demonstrating that ordered assembly of LLO is due to the strict enzyme substrate specificity. Indeed, non-physiological glycans are produced only when the luminal MTases are challenged with cytosolic substrates. Reconstitution of the LLO pathway to synthesize Man9GlcNAc2 in vitro provides an important tool for functional studies of the N-linked glycoprotein biosynthesis pathway.


Assuntos
Asparagina/metabolismo , Lipopolissacarídeos/biossíntese , Mananas/metabolismo , Manosiltransferases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Asparagina/química , Retículo Endoplasmático/metabolismo , Glicoproteínas/metabolismo , Glicosilação , Mananas/química , Manosiltransferases/genética , Manosiltransferases/isolamento & purificação , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/isolamento & purificação
7.
Reprod Sci ; 26(4): 560-568, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30466344

RESUMO

Intrauterine adhesion (IUA) is now recognized as one of the most common diseases in reproductive-age women. Metformin, a well-known frontline oral antidiabetic drug, has been found effective in numerous different diseases. The aim of this study was to determine the effect of metformin on reducing adhesions in an animal model of IUA. Sprague-Dawley rats were randomized into 4 groups: sham operation, control, metformin-treated for 7 days, and metformin-treated for 14 days. To establish the IUA model, mechanical injury to the endometria of rats was induced with a mini curette. Metformin was injected intraperitoneally after surgery. A significant amelioration in both the number of glands and the fibrotic area, compared to those of the control group, was detected 14 days after metformin intervention. The expression levels of antigen KI-67 and vascular endothelial growth factor were increased at 7 and 14 days after treatment. However, the transforming growth factor-ß expression was decreased at 14 days after treatment. Endoplasmic reticulum stress-related apoptosis proteins (glucose-regulated protein 78, caspase-12, and CCAAT/enhancer binding protein (EBP) homologous protein) were downregulated after metformin treatment. Moreover, we determined that the effect of metformin was related to the inhibition of endoplasmic reticulum stress-induced apoptosis via the Phosphatidylinositol 3 kinase (PI3K)/Protein kinase B (AKT) and Extracellular regulated protein kinases1/2 pathways. In conclusion, metformin can attenuate the adhesion and promote the regeneration of the endometrium of the IUA rat, and metformin may serve as a novel therapeutic strategy for IUA patients.


Assuntos
Apoptose/efeitos dos fármacos , Endométrio/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ginatresia/prevenção & controle , Metformina/administração & dosagem , Regeneração/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Endométrio/metabolismo , Endométrio/patologia , Feminino , Fibrose/prevenção & controle , Ginatresia/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Ratos Sprague-Dawley
8.
Glycobiology ; 28(10): 741-753, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29939232

RESUMO

In eukaryotes, the biosynthesis of a highly conserved dolichol-linked oligosaccharide (DLO) precursor Glc3Man9GlcNAc2-pyrophosphate-dolichol (PP-Dol) begins on the cytoplasmic face of the endoplasmic reticulum (ER) and ends within the lumen. Two functionally distinguished heteromeric glycosyltransferase (GTase) complexes are responsible for the cytosolic DLO assembly. Alg1, a ß-1, 4 mannosyltransferase (MTase) physically interacts with Alg2 and Alg11 proteins to form the multienzyme complex which catalyzes the addition of all five mannose to generate the Man5GlcNAc2-PP-Dol intermediate. Despite the fact that Alg1 plays a central role in the formation of the multi-MTase has been confirmed, the topological information of Alg1 including the molecular mechanism of membrane association are still poorly understood. Using a combination of bioinformatics and biological approaches, we have undertaken a structural and functional study on Alg1 protein, in which the enzymatic activities of Alg1 and its variants were monitored by a complementation assay using the GALpr-ALG1 yeast strain, and further confirmed by a liquid chromatography-mass spectrometry-based in vitro quantitative assay. Computational and experimental evidence confirmed Alg1 shares structure similarity with Alg13/14 complex, which has been defined as a membrane-associated GT-B GTase. Particularly, we provide clear evidence that the N-terminal transmembrane domain including the following positively charged amino acids and an N-terminal amphiphilic-like α helix domain exposed on the protein surface strictly coordinate the Alg1 orientation on the ER membrane. This work provides detailed membrane topology of Alg1 and further reveals its biological importance at the spatial aspect in coordination of cytosolic DLO biosynthesis.


Assuntos
Membrana Celular/metabolismo , Dolicóis/biossíntese , Manosiltransferases/metabolismo , Oligossacarídeos/biossíntese , Saccharomyces cerevisiae/metabolismo , Membrana Celular/química , Dolicóis/química , Manosiltransferases/química , Manosiltransferases/genética , Oligossacarídeos/química , Conformação Proteica , Saccharomyces cerevisiae/citologia
9.
J Zhejiang Univ Sci B ; 19(5): 383-389, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29732749

RESUMO

The pathogenesis and therapeutic treatment of intrauterine adhesions (IUAs) remain unsolved, highlighting the need for stable and effective experimental animal models. In this study, uterine electrocoagulation of twenty-one female New Zealand White rabbits was carried out to establish an IUA model. As rabbits have two completely separate uterine horns, each rabbit had its own internal control: one uterine horn was given an electrothermal injury (Group A, n=21), and the contralateral uterine horn received no treatment and served as the control (Group B, n=21). The endometrial morphology, number of endometrial glands, area of endometrial fibrosis, and number of implanted fetuses were compared between the two groups. In Group A, the numbers of endometrial glands on Days 7 and 14 and the number of implanted fetuses were significantly lower than those in Group B (P<0.05, P<0.05, and P<0.01, respectively), while the ratio of the area with endometrial stromal fibrosis to the total endometrial area was significantly increased (P<0.01). These results suggest that this method of electrothermal injury is effective for the establishment of a rabbit IUA model between 7 and 14 d after surgery.


Assuntos
Modelos Animais de Doenças , Aderências Teciduais/etiologia , Doenças Uterinas/etiologia , Animais , Eletrocoagulação , Endométrio/patologia , Feminino , Gravidez , Coelhos , Aderências Teciduais/patologia , Aderências Teciduais/terapia
10.
Yeast ; 35(2): 225-236, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29027702

RESUMO

In eukaryotes, the glycosylphosphatidylinositol (GPI) modification of many glycoproteins on the cell surface is highly conserved. The lipid moieties of GPI-anchored proteins undergo remodelling processes during their maturation. To date, the products of the PER1, GUP1 and CWH43 genes of the yeast Saccharomyces cerevisiae have been shown to be involved in the lipid remodelling. Here, we focus on the putative GPI remodelling pathway in the methylotrophic yeast Ogataea minuta. We found that the O. minuta homologues of PER1, GUP1 and CWH43 are functionally compatible with those of S. cerevisiae. Disruption of GUP1 or CWH43 in O. minuta caused a growth defect under non-permissive conditions. The O. minuta per1Δ mutant exhibited a more fragile phenotype than the gup1Δ or cwh43Δ mutants. To address the role of GPI modification in O. minuta, we assessed the effect of these mutations on the processing and localization of the O. minuta homologues of the Gas1 protein; in S. cerevisiae, Gas1p is an abundant and well-characterized GPI-anchored protein. We found that O. minuta possesses two copies of the GAS1 gene, which we designate GAS1A and GAS1B. Microscopy and western blotting analysis showed mislocalization and/or lower retention of Gas1Ap and Gas1Bp within the membrane fraction in per1Δ or gup1Δ mutant cells, suggesting the significance of lipid remodelling for GPI-anchored proteins in O. minuta. Localization behaviour of Gas1Bp differed from that of Gas1Ap. Our data reveals, for the first time (to our knowledge), the existence of genes related to GPI anchor remodelling in O. minuta cells.


Assuntos
Parede Celular/metabolismo , Proteínas Fúngicas/metabolismo , Leveduras/metabolismo , Sequência de Aminoácidos , Parede Celular/química , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica
11.
FASEB J ; 32(5): 2492-2506, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29273674

RESUMO

Asparagine ( N)-linked glycosylation requires the ordered, stepwise synthesis of lipid-linked oligosaccharide (LLO) precursor Glc3Man9GlcNAc2-pyrophosphate-dolichol (Glc3Man9Gn2-PDol) on the endoplasmic reticulum. The fourth and fifth steps of LLO synthesis are catalyzed by Alg2, an unusual mannosyltransferase (MTase) with two different MTase activities; Alg2 adds both an α1,3- and α1,6-mannose onto ManGlcNAc2-PDol to form the trimannosyl core Man3GlcNAc2-PDol. The biochemical properties of Alg2 are controversial and remain undefined. In this study, a liquid chromatography/mass spectrometry-based quantitative assay was established and used to analyze the MTase activities of purified yeast Alg2. Alg2-dependent Man3GlcNAc2-PDol production relied on net-neutral lipids with a propensity to form bilayers. We further showed addition of the α1,3- and α1,6-mannose can occur independently in either order but at differing rates. The conserved C-terminal EX7E motif, N-terminal cytosolic tail, and 3 G-rich loop motifs in Alg2 play crucial roles for these activities, both in vitro and in vivo. These findings provide insight into the unique bifunctionality of Alg2 during LLO synthesis and lead to a new model in which alternative, independent routes exist for Alg2 catalysis of the trimannosyl core oligosaccharide.-Li, S.-T., Wang, N., Xu, X.-X., Fujita, M., Nakanishi, H., Kitajima, T., Dean, N., Gao, X.-D. Alternative routes for synthesis of N-linked glycans by Alg2 mannosyltransferase.


Assuntos
Polissacarídeos Fúngicos/química , Bicamadas Lipídicas/química , Manosiltransferases/química , Modelos Moleculares , Oligossacarídeos/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/enzimologia , Motivos de Aminoácidos , Polissacarídeos Fúngicos/genética , Polissacarídeos Fúngicos/metabolismo , Glicosilação , Bicamadas Lipídicas/metabolismo , Manosiltransferases/genética , Manosiltransferases/metabolismo , Oligossacarídeos/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Relação Estrutura-Atividade
14.
Reprod Toxicol ; 74: 40-47, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28870491

RESUMO

Immune challenge in early life has been observed to influence the long-term reproductive dysfunction. On PNDs 3 and 5, female offsprings were administered with LPS (50µg/kg, i.p.) or saline. Vaginal opening was recorded, and oestrous cyclicity was monitored immediately post puberty and again at 56-70 days. At 10 weeks of age, the ovaries were removed for immunostaining and RNA analysis. Neonatal exposure to LPS resulted in a significant delay puberty onset as well as destroyed expression of ovulation related genes. At PND 42 and 70, a significant increase in Kiss1 mRNA and Kisspeptin expression was detected at proestrus and oestrus in neo-LPS treated rats compared with the counterparts. Therefore, neonatal LPS exposure had a long-term effect on reproductive function and the up-regulated expression of ovarian Kiss1 and kisspeptin during the ovulatory transition stage may contribute to ovulatory dysfunction induced by peripheral LPS administration in early life.


Assuntos
Kisspeptinas/metabolismo , Lipopolissacarídeos/farmacologia , Ovário/efeitos dos fármacos , Receptores de Kisspeptina-1/metabolismo , Animais , Animais Recém-Nascidos , Ciclo Estral/efeitos dos fármacos , Feminino , Kisspeptinas/genética , Ovário/metabolismo , Ratos Sprague-Dawley , Receptores de Kisspeptina-1/genética , Reprodução/efeitos dos fármacos , Reprodução/genética , Maturidade Sexual/efeitos dos fármacos
15.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 25(3): 890-895, 2017 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-28641655

RESUMO

Obsjective:To investigate the effects of differentaction time of IL-1ß on the osteogenic capacity of bone marrow mensenchymal cells(BMMSC) and the role of nuclear factor-κB (NF-kB) pathway. METHODS: BMMSC isolated from normal donors was treated with IL-1ß for 1 or 7 days, respectively. Alkaline phosphatase (ALP) and alizarin red(AR) stainings were used to detect the osteogenic differentiation potential of BMMSC. The mRNA expression of EphB4, IGF-1 and OPG in BMMSC was measured by real-time PCR. The immunohistochemistry was employed to measure the expression of bone morphgenetic protein-2(BMP-2) and p-Smad1/5/8 in BMMSC. Furthermore, the Western blot was used for the detection of iκBα and phospho-iκBα (p-ikBα) in IL-1ß-treated BMMSC. And the results of IL-1ß-treated BMMSC were compared with control group. RESULTS: Compared with control group, the osteogenetic potential of IL-1ß-treated BMMSC was enhanced, but the pro-osteogenic differentiation effect of IL-1ß was remarkedly inhibited in the presence of NF-kB pathway inhibitor PDTC. The total ikBα level of IL-1ß-treated BMMSC was lower (P<0.05), and phospho-iκBα (p-iκBα) level was higher (P<0.05). Besides, BMP-2 expression was higher (P<0.05) in the IL-1ß-treated BMMSC, however, p-Smad1/5/8 protien level was not significantly different among IL-1ß-treated for 1 d, 7 d and control groups (P<0.05). And the mRNA expression levels of IGF-1, EphB4 and OPG in BMMSC were up-regulated after IL-1ß treatment (P<0.05). In addition, the osteoblastogenesis of BMMSC treated with IL-1ß for 7 days was significantly different from those treated only for 1 day. CONCLUSION: Prolonging IL-1ß treatment can enhance the osteogenetic differentiation of BMMSC more significantly. And this osteogenetic alteration of BMMSC occurs via its NF-κB pathway, but not via BMP-2/Smad pathway.


Assuntos
Interleucina-1beta/farmacologia , Células-Tronco Mesenquimais , Osteogênese , Células da Medula Óssea , Diferenciação Celular , Humanos , NF-kappa B
16.
Inflamm Res ; 66(2): 187-196, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27900412

RESUMO

OBJECTIVE: The activation of NF-κB signaling and unbalance of T-helper (Th) cells have been reported to play a key role in the pathogenesis of colitis. Cortex Phellodendri Chinensis (CPC) is commonly used to treat inflammation and diarrhea. Demethyleneberberine (DMB), a component of CPC, was reported to treat alcoholic liver disease as a novel natural mitochondria-targeted antioxidant in our previous study. In this study, we investigated whether DMB could protect against dextran sulfate sodium (DSS)-induced inflammatory colitis in mice by regulation of NF-κB pathway and Th cells homeostatis. METHODS: Inflammatory colitis mice were induced by 3% DSS, and DMB were orally administered on the doses of 150 and 300 mg/kg. In vitro, DMB (10, 20, 40 µM) and N-acetyl cysteine (NAC, 5 mM) were co-cultured with RAW264.7 for 2 h prior to lipopolysaccharide (LPS) stimulation, and splenocytes from the mice were cultured ex vivo for 48 h for immune response test. RESULTS: In vivo, DMB significantly alleviated the weight loss and diminished myeloperoxidase (MPO) activity, while significantly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor-α (TNF-α), and inhibited the activation of NF-κB signaling pathway. Furthermore, DMB decreased interferon (IFN)-γ, increased IL-4 concentration in the mice splenocytes and the ratio of IgG1/IgG2a in the serum. In vitro, ROS production and pro-inflammation cytokines were markedly inhibited by DMB in RAW264.7 cell. CONCLUSIONS: Our findings revealed that DMB alleviated mice colitis and inhibited the inflammatory responses by inhibiting NF-κB pathway and regulating the balance of Th cells.


Assuntos
Anti-Inflamatórios/farmacologia , Berberina/análogos & derivados , Doenças Inflamatórias Intestinais/imunologia , NF-kappa B/antagonistas & inibidores , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Animais , Anti-Inflamatórios/uso terapêutico , Berberina/farmacologia , Berberina/uso terapêutico , Colo/efeitos dos fármacos , Colo/imunologia , Colo/patologia , Citocinas/imunologia , Sulfato de Dextrana , Feminino , Homeostase/efeitos dos fármacos , Imunoglobulina G/sangue , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/induzido quimicamente , Doenças Inflamatórias Intestinais/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/imunologia , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Baço/citologia , Linfócitos T Auxiliares-Indutores/imunologia
17.
ACS Appl Mater Interfaces ; 7(45): 25506-13, 2015 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-26509281

RESUMO

Highly aligned nanoarchitecture arrays directly grown on conducting substrates open up a new direction to accelerate Faradaic reactions for charge storage as well as address "dead volume" limitations for high-performance pseudocapacitor electrodes. Here we reported the electrochemical fabrication of well-ordered polypyrrole (PPy) nanowire arrays (NWAs) on surfaces of carbon fibers in an untreated carbon cloth to construct hierarchical structures constituted by the three-dimensional conductive carbon fiber skeleton and the atop well-ordered electroactive polymer nanowires. The morphologies, wetting behaviors, and charge-storage performances of the polymer were investigated by scanning electron microscopy, transmission electron microscopy, contact-angle measurement, cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The well-ordered PPy NWA electrode exhibited a high specific capacitance of 699 F/g at 1 A/g with excellent rate capability, and 92.4% and 81.5% of its capacitance could be retained at 10 and 20 A/g, respectively. An extremely high energy density of 164.07 Wh/kg could be achieved by the PPy NWAs at a power density of 0.65 kW/kg. It also displayed a quite high energy density of 133.79 Wh/kg at a high power density of 13 kW/kg. The assembled symmetric supercapacitor of PPy NWAs//PPy NWAs also exhibited excellent rate capability, and only 19% of its energy density decreased when the power density increased 20 times from 0.65 to 13 kW/kg.

18.
Dalton Trans ; 44(24): 11155-64, 2015 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-25997385

RESUMO

A visible light active photocatalyst was synthesized successfully by coating graphene oxide (GO) on a coordination polymer nanobelt (CPNB) using a simple colloidal blending process. Compared with neat CPNB, the resulting graphene oxide coated coordination polymer nanobelt composite material (GO/CPNB) exhibits excellent photocatalytic efficiency in the reduction of K2Cr2O7 under visible light irradiation. In the composite material, GO performs two functions. Firstly, it cuts down the band gap (E(g)) of the photocatalyst and extends its photoresponse region from the ultraviolet to visible light region. Secondly, GO exhibits excellent electron transportation ability that impedes its recombination with holes, and this can enhance photocatalytic efficiency. For GO, on its surface, the number of functional groups has a great influence on the photocatalytic performance of the resulting GO/CPNB composite material and an ideal GO"coater" to obtain a highly efficient GO/CPNB photocatalyst has been obtained. As a photocatalyst that may be used in the treatment of Cr(VI) in wastewater, GO/CPNB exhibited outstanding stability during the reduction of this pollutant.


Assuntos
Carcinógenos Ambientais/química , Cromo/química , Grafite/química , Óxidos/química , Polímeros/química , Dicromato de Potássio/química , Carcinógenos Ambientais/isolamento & purificação , Catálise , Cromo/isolamento & purificação , Luz , Oxirredução , Processos Fotoquímicos , Dicromato de Potássio/isolamento & purificação
19.
Chemistry ; 21(9): 3821-30, 2015 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-25641070

RESUMO

To improve the photocatalytic properties of coordination polymers under irradiation in the visible-light region, coordination polymer nanobelts (CPNB) were loaded on functional carbon fiber (FCF) through the use of a simple colloidal blending process. The resulting coordination polymer nanobelt loaded functional carbon fiber composite material (CPNB/FCF) exhibited dramatically improved photocatalytic activity for the degradation of rhodamine B (RhB) under visible-light irradiation. Optical and electrochemical methods illustrated the enhanced photocatalytic activity of CPNB/FCF originated from high separation efficiency of photogenerated electrons and holes on the interface of CPNB and FCF, which was produced by the synergy effect between them. In the composite material, the role of FCF could be described as photosensitizer and good electron transporter. For FCF, the number of functional groups on its surface has a significant influence on the photocatalytic performance of the resulting CPNB/FCF composite material, and an ideal FCF carrier was obtained as a highly efficient CPNB/FCF photocatalyst. CPNB/FCF showed outstanding stability during the degradation of rhodamine B (RhB); thus, the material is suitable for use as a photocatalyst in the treatment of organic dyes in water.

20.
J Inorg Biochem ; 138: 73-80, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24915440

RESUMO

DNA condensation induced by a pair of heptameric La(III) helical enantiomers M-[La7(S-L)6(CO3)(NO3)6(OCH3)(CH3OH)7]·2CH3OH·5H2O and P-[La7(R-L)6(CO3)(NO3)6(OCH3)(CH3OH)5(H2O)2]·2CH3OH·4H2O (M-La and P-La, L=2-(2-hydroxybenzylamino)-3-carbamoylpropanoic acid) has been investigated by UV/vis spectroscopy, fluorescence spectroscopy, CD spectroscopy, EMSA, RALS, DLS, and SEM. The enantiomers M-La and P-La could induce CT-DNA condensation at a low concentration as observed in UV/vis spectroscopy. DNA condensates possessed globular nanoparticles with nearly homogeneous sizes in solid state determined by SEM (ca. 250 nm for M-La and ca. 200 nm for P-La). The enantiomers bound to DNA through electrostatic attraction and hydrogen bond interactions in a major groove, and rapidly condensed free DNA into its compact state. DNA decompaction has been acquired by using EDTA as disassembly agent, and analyzed by UV/vis spectroscopy, CD spectroscopy and EMSA. Moreover, the enantiomers M-La and P-La displayed discernible discrimination in DNA interaction and DNA condensation, as well as DNA decondensation. Our study suggested that lanthanum(III) enantiomers M-La and P-La were efficient DNA packaging agents with potential applications in gene delivery.


Assuntos
Complexos de Coordenação/química , DNA/química , Lantânio/química , Dicroísmo Circular , Ensaio de Desvio de Mobilidade Eletroforética , Microscopia Eletrônica de Varredura , Espalhamento de Radiação , Espectrofotometria Ultravioleta , Análise Espectral , Estereoisomerismo
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