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1.
Viruses ; 15(9)2023 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-37766344

RESUMO

African swine fever (ASF) is one of the most severe diseases caused by the ASF virus (ASFV), causing massive economic losses to the global pig industry. Serological tests are important in ASF epidemiological surveillance, and more antigen targets are needed to meet market demand for ASFV antibody detection. In the present study, ASFV p15 protein was fusion-expressed in Escherichia coli (E. coli) with elastin-like polypeptide (ELP), and the ELP-p15 protein was purified using a simple inverse transition cycling (ITC) process. The ELP tag was cleaved off using tobacco etch virus protease (TEVp), resulting in a tag-free p15 protein. Western blot analysis demonstrated that the p15 protein reacted strongly with ASFV-positive serum. The p15 protein was used as a coating antigen in an indirect ELISA (iELISA) for detecting ASFV antibodies. The p15-iELISA method demonstrated high specificity to ASFV-positive sera, with a maximum detection dilution of 1:1600. Moreover, the method exhibited good reproducibility, with less intra-assay and inter-assay CV values than 10%. Therefore, p15-iELISA offers a novel approach for accurately detecting ASFV antibodies with significant clinical application potential.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Animais , Suínos , Febre Suína Africana/diagnóstico , Escherichia coli/genética , Reprodutibilidade dos Testes , Ensaio de Imunoadsorção Enzimática , Anticorpos
2.
J Plant Physiol ; 287: 154062, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37540924

RESUMO

Okra (Abelmoschus esculentus L.) is a tropical crop species, and its growth and development are severely affected by cold stress. Recent studies have identified a potential association between WRKY transcription factors and the cold response mechanism of crops. In this study, the AeWRKY32 transcription factor that encodes 482 amino acids was amplified from A. esculentus, and its expression level was found to be the highest in the okra flower. AeWRKY32 localized to the nucleus and displayed transcriptional activation capability. Under normal conditions, overexpression of AeWRKY32 induced anthocyanin accumulation, with higher expression levels of AtCHS1, AtCHI4, AtF3H1, and AtDFR2 in transgenic Arabidopsis. Under cold stress, anthocyanin levels were further elevated in transgenic Arabidopsis plants. At the same time, AeWRKY32 overexpression promoted ABA biosynthesis, inhibited H2O2 and O2- generation, induced stomatal closure, reduced electrolyte leakage, and thus improved the cold resistance of transgenic Arabidopsis. Furthermore, under cold stress, the expression profiles of AtCOR413, AtCOR15B, AtCBF1, and AtCBF2 were upregulated in transgenic Arabidopsis. Overall, our study provides evidence that AeWRKY32 serves as a crucial regulator in both anthocyanin accumulation and cold tolerance of transgenic Arabidopsis. Our findings could provide insights into the molecular mechanism linking AeWRKYs to plant cold tolerance.


Assuntos
Abelmoschus , Arabidopsis , Arabidopsis/metabolismo , Abelmoschus/metabolismo , Antocianinas/metabolismo , Proteínas de Plantas/metabolismo , Peróxido de Hidrogênio/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico , Temperatura Baixa
3.
Front Med (Lausanne) ; 9: 878601, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35685407

RESUMO

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and devastating chronic lung condition affecting over 3 million people worldwide with a high mortality rate and there are no effective drugs. Angiotensin II (Ang II), as a major effector peptide of the renin angiotensin aldosterone system, has been shown to act in tandem with the transforming growth factor-ß (TGF-ß) signaling pathway to promote the infiltration of inflammatory cells, production of reactive oxygen species (ROS) and profibrotic factors after lung injury, and to participate in the process of epithelial mesenchymal transition (EMT). Catalpol (CAT) has been shown to have anti-inflammatory and antifibrotic effects. However, the effects and mechanisms of CAT on pulmonary fibrosis are not clear. Purpose: To assess the effects and mechanisms of catalpol on bleomycin-induced pulmonary fibrosis in mice. Methods: We used bleomycin-induced mouse model of pulmonary fibrosis to evaluate the alleviation effect of CAT at 7, 14, 28d, respectively. Next, enzyme-linked immunosorbent assay, hematoxylin-eosin staining, immunofluorescence, Masson trichrome staining and western blotting were used to study the underlying mechanism of CAT on bleomycin-induced pulmonary fibrosis. Results: It's demonstrated that CAT exerted a potent anti-fibrotic function in BLM-induced mice pulmonary fibrosis via alleviating inflammatory, ameliorating collagen deposition, reducing the level of Ang II and HYP and alleviating the degree of EMT. Moreover, CAT attenuate BLM-induced fibrosis by targeting Ang II/AT1 and TGF-ß/Smad signaling in vivo. Conclusion: CAT may serve as a novel therapeutic candidate for the simultaneous blockade of Ang II and TGF-ß pathway to attenuate pulmonary fibrosis.

4.
Front Pharmacol ; 13: 825667, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35222040

RESUMO

Pulmonary fibrosis (PF) is a clinically common disease caused by many factors, which will lead to lung function decline and even respiratory failure. Jingyin granule has been confirmed to have anti-inflammatory and antiviral effects by former studies, and has been recommended for combating H1N1 influenza A virus (H1N1) infection and Coronavirus disease 2019 (COVID-19) in China. At present, studies have shown that patients with severe COVID-19 infection developed lung fibrotic lesions. Although Jingyin granule can improve symptoms in COVID-19 patients, no study has yet reported whether it can attenuate the process of PF. Here, we explored the underlying mechanism of Jingyin granule against PF by network pharmacology combined with in vitro experimental validation. In the present study, the active ingredients as well as the corresponding action targets of Jingyin granule were firstly collected by TCMSP and literature data, and the disease target genes of PF were retrieved by disease database. Then, the common targets were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, and then a PPI network and an ingredient-target network were constructed. Next, UPLC-MS was used to isolate and identify selected representative components in Jingyin granule. Finally, LPS was used to induce the A549 cell fibrosis model to verify the anti-PF effect of Jingyin granule in vitro. Our results indicated that STAT3, JUN, RELA, MAPK3, TNF, MAPK1, IL-6, and AKT1 were core targets of action and bound with good affinity to selected components, and Jingyin granule may alleviate PF progression by Janus kinase 2/signal transducers and activators of transcription (JAK2/STAT3), the mammalian nuclear factor-κB (NF-κB), the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), tumor necrosis factor (TNF), and the extracellular signal-regulated kinases 1 and 2 (ERK1/2) signaling pathways. Overall, these results provide future therapeutic strategies into the mechanism study of Jingyin granule on PF.

5.
Front Pharmacol ; 12: 733618, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34658873

RESUMO

Pulmonary fibrosis, a common outcome of pulmonary interstitial disease of various different etiologies, is one of the most important causes of respiratory failure. Houttuynia cordata Thunb. (family: Saururaceae) (H. cordata), as has been reported, is a Chinese herbal medicine commonly used to treat upper respiratory tract infection and bronchitis. Our previous study has proven that sodium houttuyfonate (an additional compound from sodium bisulfite and houttuynin) had beneficial effects in the prevention of pulmonary fibrosis (PF) induced by bleomycin (BLM) in mice. In the present study, network pharmacology was used to investigate the efficiency and potential mechanisms of H. cordata in PF treatment. Upon manual collection from the literature and databases such as TCMSP and TCM-ID, 10 known representative ingredients of H. cordata species were screened. Then, the prediction of the potential active ingredients, action targets, and signaling pathways were conducted through the Gene Ontology (GO), protein-protein interaction (PPI),and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The results of network pharmacology prediction suggested that H. cordata may act through multiple signaling pathways to alleviate PF, including the phosphatidylinositol 3-kinase-protein kinase B (PI3K/AKT) pathways, mitogen-activated protein kinase (MAPK) pathways, the tumor necrosis factor (TNF) pathways, and interleukin-17 (IL-17) signaling pathways. Molecular docking experiments showed that the chemical constituents of H. cordata had good affinity with TNF, MAPK1, and AKT1, and using lipopolysaccharide (LPS)-induced A549 cells, a model was established to verify the anti-pulmonary fibrosis effects and related mechanisms of H. cordata-relevant constituents. Finally, these evidences collectively suggest H. cordata may alleviate PF progression via PI3K/Akt, MAPK, and TNF signaling pathways and provide novel insights to verify the mechanism of H. cordata in the treatment of PF.

6.
Front Pharmacol ; 12: 596492, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33716736

RESUMO

Pulmonary fibrosis (PF) could severely disrupt the normal lung architecture and function with fatal consequences. Currently, there is no effective treatment for PF or idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate the effects of Sodium Houttuyfonate (SH) on bleomycin (BLM) induced PF mice model. Our results indicated that SH could attenuate BLM induced lung injury by reducing the inflammation, fibrogenesis and lung/body weight ratio. The proposed mechanisms for the protective effects of SH include: 1) improvement of pulmonary function in BLM mice, for instance, it can elevate the vital capacity (VC), increase the forced expiratory flow at 50% of forced vital capacity (FEF50) and improve other pulmonary function indices; 2) inhibition of collagen formation in BLM mice; 3) attenuation of the elevation of inflammatory cytokines, such as interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α), which are triggered by BLM administration; 4) reduction of the mRNA level and protein production of transforming growth factor-ß1 (TGF-ß1) in BLM mice. Furthermore, it was found that the protective effects of SH against BLM induced PF in mice was comparable to that of prednisone acetate (PA) tablets, a widely used drug for immunological diseases. Although Houttuynia Cordata Thunb has been widely used in China for lung infection and inflammation, the mechanism has not yet been fully elucidated. Our study provides the evidence that SH is an effective compound against pulmonary injury, irritation and fibrogenesis.

7.
Chemosphere ; 266: 128985, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33228990

RESUMO

This study aimed to reveal the baseline of natural variations in antibiotic resistance genes (ARGs) in soil without anthropogenic activities over the decades. Nine soil samples with different time of soil formation were taken from the Yancheng Wetland National Nature Reserve, China. ARGs and mobile genetic elements (MGEs) were characterized using metagenomic analysis. A total of 196 and 192 subtypes of ARGs were detected in bulk soil and rhizosphere, respectively. The diversity and abundance of ARGs were stable during 69 years probably due to the alkaline pH soil environment but not due to antibiotics. Increases in ARGs after 86 years were probably attributed to more migrant birds inhabited compared with other sampling sites. Multidrug was the most abundant type, and largely shared by soil samples. It was further shown that soil samples could not be clearly distinguished, suggesting a slow process of succession of ARGs in the mudflat. The variation partitioning analysis revealed that the ARG profile was driven by the comprehensive effects exhibited by the bacterial community, MGEs, and environmental factors. Besides, pathogenic bacteria containing ARGs mediated by migrant birds in the area with 86 years of soil formation history nearing human settlements needed special attention. This study revealed the slow variations in ARGs in the soil ripening process without anthropogenic activities over decades, and it provided information for assessing the effect of human activities on the occurrence and dissemination of ARGs.


Assuntos
Antibacterianos , Solo , Antibacterianos/farmacologia , China , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Humanos
8.
J Mater Chem B ; 8(25): 5491-5499, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32478780

RESUMO

We present a facile organic phase synthesis method for producing multi-branched gold nanocrystals (nanostars) with a broad localized surface plasmon resonance (LSPR) across near-infrared (NIR) to short-wave infrared (SWIR) wavelengths. In this approach, galvanic replacement of copper by gold, in seed particles produced in situ, initiates growth of multi-branched structures. The method enables broad tuning of the LSPR energy by manipulating the branch length, with peak LSPR absorbance tuned from 850 to 1880 nm, reaching SWIR wavelengths covering the second and third optical transparency windows in biological media, rarely achieved with noble metal plasmonic nanostructures. After a ligand-exchange process, the gold nanostars readily disperse in water while retaining their LSPR absorbance. The multi-branched Au nanocrystals (NCs) exhibit exceptionally high photothermal transduction efficiency, exceeding that of Au nanorods and nanoparticles, to which we make direct comparisons here. At the same time, their synthesis is much more straightforward than hollow structures like nanocages, nanoshells, and nanomatryoshkas that can also exhibit high photothermal efficiency at NIR wavelengths. In vitro photothermal heating of multi-branched Au NCs in the presence of human cervical cancer cells causes effective cell ablation after 10 min laser irradiation. Cell viability assays demonstrate that the NCs are biocompatible at doses required for photothermal therapy. These results suggest that the multi-branched Au NCs can serve as a new type of photothermal therapy agent and in other applications in which strong NIR to SWIR absorbers are needed.


Assuntos
Antineoplásicos/farmacologia , Ouro/farmacologia , Nanopartículas Metálicas/química , Neoplasias/patologia , Terapia Fototérmica , Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Ouro/química , Células HeLa , Humanos , Raios Infravermelhos , Neoplasias/terapia , Imagem Óptica , Tamanho da Partícula , Ressonância de Plasmônio de Superfície , Propriedades de Superfície
9.
Chemosphere ; 253: 126729, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32289610

RESUMO

Microorganisms with high tetracycline (TC) degradation efficiencies are required for biological processes for TC-containing wastewater treatment. With multiple enrichment cultures, a TC-degrading strain TR5 was isolated from chicken manure mixture in a large broiler farm, which was identified as Klebsiella pneumoniae by 16S rRNA gene sequencing and biochemical properties. Strain TR5 could degrade TC quickly (∼90% within 36 h) with the initial TC concentration of 200 mg/L under optimized conditions via single-factor experiment coupled with RSM. Strain TR5 could detoxify TC and generate much less toxic products as long as cultured more than one day. Three TC-degrading pathways were proposed based on 8 possible products. A transformant containing a plasmid from TR5 acquired TC-degrading ability, indicating that TC-degrading genes were located on this plasmid. Complete sequencing of pYK5 showed that isomerase-, oxidoreductase-, and transferases-encoding genes were found and were inferred to be involved in TC degradation. TR5 may not degrade TC completely and it can utilize some carbon-containing compounds derived from TC via the effect of formylglutathione hydrolase-encoding gene. Our findings showed that strain TR5 could be a promising agent for wastewater treatment, and genes involved in TC degradation are worthy of further investigations for enzyme preparations development.


Assuntos
Antibacterianos/análise , Genes Bacterianos , Klebsiella/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Tetraciclina/análise , Águas Residuárias/química , Animais , Biodegradação Ambiental , Galinhas/metabolismo , Klebsiella/genética , Esterco/análise , Redes e Vias Metabólicas/genética , Plasmídeos , RNA Ribossômico 16S/genética
10.
Nanoscale ; 11(1): 136-144, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30525174

RESUMO

Colloidal metal sulphide (MS) nanocrystals (NCs) have recently attracted considerable attention because of their tunable properties that can be exploited in various physical, chemical and biological applications. In this work, we present a novel and general method for synthesis of monodispersed binary (CuS, Ag2S, CdS, PbS, and SnS), ternary (Ag-In-S, Cu-In-S and Cu-Sn-S) and quaternary (Cu-Zn-Sn-S) MS NCs. The synthesis is conducted at room temperature, with an immediate crystallization process and up to 60 seconds of growth time, enabling rapid synthesis without external heating. For some of the ternary and quaternary NCs produced with relatively low crystallinity, we then carried out a "colloidal annealing" process to improve their crystallinity without changing their composition. Moreover, we show that the morphology and optical properties of the NCs can be tuned by varying the concentration of precursors and reaction time. The shape evolution and photoluminescence of particular MS NCs were also studied. These results not only provide insights into the growth mechanisms of MS NCs, but also yield a generalized, low cost, and potentially scalable method to fabricate them.

11.
ACS Appl Mater Interfaces ; 10(49): 42417-42426, 2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30451490

RESUMO

Size- and shape-dependent electrochemical activity of nanostructures reveals relationships between nanostructure design and electrochemical performance. However, electrochemical performance of aspect-ratio-tunable quasi-two-dimensional (2D) nanomaterials with anisotropic properties has not been fully investigated. We prepared monodispersed hexagonal covellite (CuS) nanoplatelets (NPls) of fixed thickness (∼2 nm) but broadly tunable diameter (from 8 to >100 nm). These span a range of aspect ratios, from ∼4 to >50, connecting quasi-isotropic and quasi-2D regimes. Tests of electrochemical activity of the NPls for the oxygen reduction reaction in alkaline solution showed improved activity with increasing diameter. Combining experimental results with density functional theory calculations, we attribute size-dependent enhancement to anisotropy of conductivity and electrochemical activity. The lowest computed oxygen adsorption energy was on Cu sites exposed by cleaving covellite along (001) planes through tetrahedrally coordinated Cu atoms. The specific surface area of these planes, which are the top and bottom surfaces of the NPls, remains constant with changing diameter, for fixed NPl thickness. However, charge transport through the electrocatalyst film improves with increasing NPl diameter. These CuS NPl-carbon nanocatalysts provide inspiration for creating well-controlled layered nanomaterials for electrochemical applications and open up opportunities to design new electrocatalysts using transition-metal sulfides.

12.
Langmuir ; 34(46): 13905-13909, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30375872

RESUMO

The ability to manipulate the near-infrared (NIR) localized surface plasmon resonance absorbance of copper chalcogenide materials is of utmost importance for applications such as photothermal therapy (PTT). In this work, we manipulate the NIR absorbance of copper selenide (Cu2- xSe) nanoparticles (NPs) by precisely controlling their size and composition. We also introduce a facile method for transferring ultrasmall hydrophobic Cu2- xSe NPs into aqueous solution. We then elucidate the relationship between the irradiation wavelength and photothermal conversion efficiency for these materials. The resulting insights can advance the use of copper chalcogenide nanomaterials in PTT applications.

13.
Nanomaterials (Basel) ; 8(3)2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29538281

RESUMO

In recent years, many research groups have synthesized ultra-thin silver nanowires (AgNWs) with diameters below 30 nm by employing Cl- and Br- simultaneously in the polyol process. However, the yield of AgNWs in this method was low, due to the production of Ag nanoparticles (AgNPs) as an unwanted byproduct, especially in the case of high Br- concentration. Here, we investigated the roles of Cl- and Br- in the preparation of AgNWs and then synthesized high aspect ratio (up to 2100) AgNWs in high yield (>85% AgNWs) using a Cl- and Br- co-mediated method. We found that multiply-twinned particles (MTPs) with different critical sizes were formed and grew into AgNWs, accompanied by a small and large amount of AgNPs for the NaCl and NaBr additives, respectively. For the first time, we propose that the growth of AgNWs of different diameters and yields can be understood based on the electron trap distribution (ETD) of the silver halide crystals. For the case of Cl- and Br- co-additives, a mixed silver halide crystal of AgBr1-xClx was formed, rather than the AgBr/AgCl mixture reported previously. In this type of crystal, the ETD is uniform, which is beneficial for the synthesis of AgNWs with small diameter (30~40 nm) and high aspect ratio. AgNW transparent electrodes were prepared in air by rod coating. A sheet resistance of 48 Ω/sq and transmittance of 95% at 550 nm were obtained without any post-treatment.

14.
Sheng Wu Gong Cheng Xue Bao ; 33(6): 1046-1056, 2017 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-28895366

RESUMO

Sus scrofa lysozyme (SSL) was digested by different proteases to find peptides with enhanced antibacterial activity against gram-negative bacteria. Hydrolysate with the highest anti-bacterial activity was loaded onto a gel filtration chromatography column followed by a reversed-phase one. The obtained substance was identified by liquid chromatography-mass spectrometry, synthesized to test its antibacterial spectrum and analyzed for bioinformatics. The hydrolysate of trypsin showed the highest antibacterial activity. By purification and identification, the functional peptide with sequence of A-W-V-A-W-K was obtained. The peptide was synthesized and proved to retain partial function of SSL and had activity against gram-negative bacteria. By bioinformatics analysis, the peptide was found to locate in a helix-loop-helix structure, suggesting that the peptide may kill cells by penetrating cell membrane and cause the outflow of cell contents. The discovery of the peptide could lay the foundation for improving the antibacterial activity of SSL.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Muramidase/farmacologia , Peptídeos/farmacologia , Sus scrofa , Sequência de Aminoácidos , Animais , Testes de Sensibilidade Microbiana
15.
J Mater Chem B ; 5(25): 4934-4942, 2017 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32264009

RESUMO

In this study, we show that Au-Cu2-xSe heterogeneous nanocrystals have great promise for use in photothermal therapy (PTT). Ligand-stabilized heterogeneous gold-copper selenide (Au-Cu2-xSe) hybrid nanocrystals were synthesized by a colloidal gold seed-mediated method. The nanocrystals exhibit broad localized surface plasmon resonance (LSPR) across visible and near-infrared (NIR) wavelengths, arising from interactions between the two nanocrystal domains. After a ligand-exchange process, the NCs readily disperse in water while retaining their LSPR absorbance. Upon illumination with a 980 nm laser, the Au-Cu2-xSe nanocrystals produced significant photothermal heating with a photothermal transduction efficiency comparable to that of larger gold nanostructures that have been widely studied for PTT. In vitro photothermal heating of Au-Cu2-xSe nanocrystals in the presence of human cervical cancer cells caused cell ablation after 10 min laser irradiation. Cell viability assays demonstrated that the hybrid nanocrystals are biocompatible at doses needed for photothermal therapy. Overall, these heterogeneous nanocrystals provide the NIR PTT efficacy of larger gold nanorods in a much smaller overall nanostructure that may have advantages with respect to biodistribution and clearance.

16.
J Biotechnol ; 243: 61-68, 2017 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-28034616

RESUMO

Sus scrofa lysozyme (SSL), an important component of the pig immune system, is a potential candidate to replace antibiotics in feed. However, there is little antimicrobial activity of natural SSL against gram-negative bacteria, which limits its application. In this study, a unique peptide (A-W-V-A-W-K) with antimicrobial activity against gram-negative bacteria was discovered and purified from trypsin hydrolysate of natural SSL. This unique peptide was fused to natural SSL and the recombinant fused SSL exhibited improved activity against gram-negative bacteria. The N-terminal fusion likely increased the membrane penetrability and induced programmed bacterial cell death. The recombinant fused SSL also showed higher activity against some gram-positive bacteria with O-acetylation. By N-terminal fusion of the sextuple peptide, the anti-microbial activity, either to gram-positive or negative bacteria, of the recombinant SSL was higher than the fusion of only one copy of the peptide. This study provides a general, feasible, and highly useful strategy to enhance the antimicrobial activity of lysozyme.


Assuntos
Anti-Infecciosos/farmacologia , Muramidase/farmacologia , Peptídeos/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Sus scrofa/metabolismo , Sequência de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Morte Celular/efeitos dos fármacos , Dicroísmo Circular/métodos , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Muramidase/genética , Muramidase/metabolismo , Peptídeos/química , Peptídeos/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
17.
Nanoscale ; 6(15): 8852-7, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24957012

RESUMO

Self-doped Cu2-xS nanocrystals (NCs) were converted into monodisperse Cu2-xS-Au2S NCs of tunable composition, including pure Au2S, by cation exchange. The near-infrared (NIR) localized surface plasmon resonance (LSPR) was dampened and red-shifted with increasing Au content. Cation exchange was accompanied by elimination of cation vacancies and a change in crystal structure. Partially exchanged Cu2-xS-Au2S core/shell structures evolved to dumbbell-like structures under electron irradiation in the transmission electron microscope (TEM).

18.
Nano Lett ; 13(9): 4333-9, 2013 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-23984758

RESUMO

We report a new type of heterogeneous nanoparticles (NPs) composed of a heavily doped semiconductor domain (Cu2-xSe) and a metal domain (Au), which exhibit a broad localized surface plasmon resonance (LSPR) across visible and near-infrared (NIR) wavelengths, arising from interactions between the two nanocrystal domains. We demonstrate both in vivo photoacoustic imaging and in vitro dark field imaging, using the broad LSPR in Cu2-xSe-Au hybrid NPs to achieve contrast at different wavelengths. The high photoacoustic imaging depth achieved, up to 17 mm, shows that these novel contrast agents could be clinically relevant. More broadly, this work demonstrates a new strategy for tuning LSPR absorbance by engineering the density of free charge carriers in two interacting domains.


Assuntos
Diagnóstico por Imagem , Nanopartículas Metálicas/química , Ressonância de Plasmônio de Superfície , Meios de Contraste/química , Meios de Contraste/classificação , Cobre/química , Ouro/química , Selênio/química , Semicondutores
19.
J Integr Plant Biol ; 50(6): 733-41, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18713414

RESUMO

APase activity is involved in regulating many physiological and developmental events by affecting the resorption process. In this study, we investigate the role of APase activity in tuber development in potato. APase activities were mainly localized in cytoplasm, gaps among cells and stroma of amyloplasts of parenchyma cells at the stage of tuber swelling. AP1, encoding a putative APase, was also highly expressed in swelling tubers and a low level of expression was observed in elongated stolons and matured tubers. Inhibition of APase activity by applying Brefeldin A, an inhibitor of APase production and secretion, significantly suppressed the tuber swelling and moderately affected the stolon elongation and the tuberization frequency. During tuber development, sucrose serves as the main soluble sugar for long-distance transportation and resorption. Moreover, inhibition of APase activity by Brefeldin A markedly reduced the sucrose content in tubers and further decreased the starch accumulation, suggesting that the function of APase in regulating the tuber swelling might be at least partially mediated by the sugar resorption. Exogenous sucrose treatments further indicate the important role of sucrose-mediated sugar resorption in tuber swelling. These results suggest that the APase activity might affect the tuber swelling by partially regulating the sucrose-mediated sugar resorption.


Assuntos
Fosfatase Ácida/metabolismo , Metabolismo dos Carboidratos , Tubérculos/enzimologia , Solanum tuberosum/enzimologia , Sacarose/metabolismo , Fosfatase Ácida/antagonistas & inibidores , Fosfatase Ácida/genética , Metabolismo dos Carboidratos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Tubérculos/citologia , Tubérculos/efeitos dos fármacos , Tubérculos/crescimento & desenvolvimento , Solanum tuberosum/citologia , Solanum tuberosum/genética , Solanum tuberosum/crescimento & desenvolvimento , Amido/metabolismo
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