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1.
Int J Mol Sci ; 21(2)2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31941102

RESUMO

Previous studies have suggested that immune system development and weaning stress are closely related to the maturation of gut microbiota. The early-life period is a "window of opportunity" for microbial colonization, which potentially has a critical impact on the development of the immune system. Fecal microbiota transplantation (FMT) and probiotics are often used to regulate gut microbial colonization. This study aims to test whether early intervention with FMT using fecal microbiota from gestation sows combined with Clostridium butyricum and Saccharomyces boulardii (FMT-CS) administration could promote the maturation of gut microbiota and development of immune system in piglets. Piglets were assigned to control (n = 84) and FMT-CS treatment (n = 106), which were treated with placebo and bacterial suspension during the first three days after birth, respectively. By 16S rRNA gene sequencing, we found that FMT-CS increased the α-diversity and reduced the unweighted UniFrac distances of the OTU community. Besides, FMT-CS increased the relative abundance of beneficial bacteria, while decreasing that of opportunistic pathogens. FMT-CS also enhanced the relative abundance of genes related to cofactors and vitamin, energy, and amino acid metabolisms during the early-life period. ELISA analysis revealed that FMT-CS gave rise to the plasma concentrations of IL-23, IL-17, and IL-22, as well as the plasma levels of anti-M.hyo and anti-PCV2 antibodies. Furthermore, the FMT-CS-treated piglets showed decreases in inflammation levels and oxidative stress injury, and improvement of intestinal barrier function after weaning as well. Taken together, our results suggest that early-life intervention with FMT-CS could promote the development of innate and adaptive immune system and vaccine efficacy, and subsequently alleviate weaning stress through promoting the maturation of gut microbiota in piglets.

2.
Nano Lett ; 20(1): 33-42, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31769995

RESUMO

The reconfigurability of the electrical heterostructure featured with external variables, such as temperature, voltage, and strain, enabled electronic/optical phase transition in functional layers has great potential for future photonics, computing, and adaptive circuits. VO2 has been regarded as an archetypal phase transition building block with superior metal-insulator transition characteristics. However, the reconfigurable VO2-based heterostructure and the associated devices are rare due to the fundamental challenge in integrating high-quality VO2 in technologically important substrates. In this report, for the first time, we show the remote epitaxy of VO2 and the demonstration of a vertical diode device in a graphene/epitaxial VO2/single-crystalline BN/graphite structure with VO2 as a reconfigurable phase-change material and hexagonal boron nitride (h-BN) as an insulating layer. By diffraction and electrical transport studies, we show that the remote epitaxial VO2 films exhibit higher structural and electrical quality than direct epitaxial ones. By high-resolution transmission electron microscopy and Cs-corrected scanning transmission electron microscopy, we show that a graphene buffered substrate leads to a less strained VO2 film than the bare substrate. In the reconfigurable diode, we find that the Fermi level change and spectral weight shift along with the metal-insulator transition of VO2 could modify the transport characteristics. The work suggests the feasibility of developing a single-crystalline VO2-based reconfigurable heterostructure with arbitrary substrates and sheds light on designing novel adaptive photonics and electrical devices and circuits.

3.
Medicine (Baltimore) ; 98(49): e18276, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31804368

RESUMO

RATIONALE: Pulmonary benign metastasizing leiomyoma (PBML) is rare, usually occurs in women who underwent hysterectomy during the reproductive years, and has no obvious clinical symptoms. A full understanding of the characteristics of PBML is important for its sequential treatment and prognosis. PATIENT CONCERNS: In this report, a 36-year-old female patient with previous uterine leiomyoma who underwent 3 surgical resections of the uterus, bilateral fallopian tubes, and partial omentum was investigated. The physical examination revealed a tumor in the right lower lobe and mediastinum and a solid nodule in the right middle lobe. DIAGNOSES: Chest computed tomography (CT) confirmed a tumor in the right lower lobe and mediastinum and a solid nodule in the right middle lobe. Further positron-emission tomography computed tomography (PET-CT) with 18F-fluorodeoxyglucose (FDG) of the whole body showed mildly intense accumulation of 18F-FDG in the tumor (maximum standardized uptake value [SUV max], 2.6). A pathological examination then confirmed the presence of fibrous and vascular tissue after CT-guided percutaneous biopsy of the tumor in the right lower lobe. Additionally, surgical resection of the tumor and nodule was performed for histological analysis and immunohistochemical assays for estrogen receptor (ER) and progesterone receptor (PR). INTERVENTIONS: The patient underwent complete tumor surgical resection and nodule wedge resection. OUTCOMES: No postoperative complications occurred. No recurrence or other signs of metastasis were found during an 18-month follow-up observation period. CONCLUSION: In this case, lung and mediastinal metastasis of uterine fibroids was observed. However, depending on only a postoperative histological analysis is insufficient for the diagnosis of PBML. Histological analysis combined with an evaluation of the expression levels of ER and PR is crucial for the diagnosis and treatment of PBML.


Assuntos
Leiomioma/patologia , Neoplasias Pulmonares/secundário , Neoplasias do Mediastino/secundário , Neoplasias Uterinas/patologia , Adulto , Feminino , Humanos , Biópsia Guiada por Imagem , Leiomioma/cirurgia , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Neoplasias do Mediastino/diagnóstico por imagem , Neoplasias do Mediastino/cirurgia , Neoplasias Uterinas/cirurgia
4.
Cell Mol Bioeng ; 12(1): 85-97, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31719900

RESUMO

Introduction: Fluid shear stress (FSS) is the most common stress produced by mastication, speech, or tooth movement. However, how FSS regulates human periodontal ligament (PDL) cell proliferation and migration as well as the underlying mechanism remains unknown. Methods: FSS (6 dyn/cm2) was produced in a flow chamber. Cell proliferation was tested by the 5-ethynyl-2'-deoxyuridine assay. Cell migration was tested by the wound healing assay. Gene and protein expression of platelet-derived growth factors (PDGFs) and matrix metalloproteinase (MMP)-2 were measured by reverse transcription-polymerase chain reaction and western blot analyses. Results: We investigated the effect of 4 h of 6 dyn/cm2 FSS on proliferation and migration of PDL cells. FSS promoted PDL cell proliferation but inhibited migration. The gene and protein expression of PDGF receptor (PDGFR)-α and ß both decreased in response to FSS. Activating and inhibiting the PDGFRs did not affect the FSS-induced increase in cell proliferation. However, activating PDGFRs with PDGF-BB, which bound both PDGFR-α and ß, and PDGF-CC and DD, which had high affinities for PDGFR-α and PDGFR-ß, individually rescued FSS-inhibited migration. FSS also inhibited MMP-2 gene expression, which was the most important factor for matrix turnover and migration of PDLs. PDGF-BB, CC, and DD increased the FSS-induced decline in MMP-2 expression. These results indicate that MMP-2 is regulated by FSS and contributes to the FSS-induced decrease in cell migration. Conclusions: Our study suggests a role for PDGFR-α and ß in short-term FSS-regulated cell proliferation and migration. These results will help provide the scientific foundation for revealing the mechanisms clinical tooth movement and PDL regeneration.

6.
Nat Commun ; 10(1): 4145, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31515482

RESUMO

Crystallographic dislocation has been well-known to be one of the major causes responsible for the unfavorable carrier dynamics in conventional semiconductor devices. Halide perovskite has exhibited promising applications in optoelectronic devices. However, how dislocation impacts its carrier dynamics in the 'defects-tolerant' halide perovskite is largely unknown. Here, via a remote epitaxy approach using polar substrates coated with graphene, we synthesize epitaxial halide perovskite with controlled dislocation density. First-principle calculations and molecular-dynamics simulations reveal weak film-substrate interaction and low density dislocation mechanism in remote epitaxy, respectively. High-resolution transmission electron microscopy, high-resolution atomic force microscopy and Cs-corrected scanning transmission electron microscopy unveil the lattice/atomic and dislocation structure of the remote epitaxial film. The controlling of dislocation density enables the unveiling of the dislocation-carrier dynamic relation in halide perovskite. The study provides an avenue to develop free-standing halide perovskite film with low dislocation density and improved carried dynamics.

7.
Biosci Rep ; 39(5)2019 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-30975732

RESUMO

Snail1 plays an important role in epithelial to mesenchymal transition (EMT) during tumor metastasis; however, whether Snai1 potentiates the process of neoangiogenesis is completely unknown. In the present study, tube formation assay was used to evaluate neoangiogenesis in vitro The expression of Snai1 and other pro-neoangiogenic factors was measured by quantitative real time PCR. Tumor derived endothelial cells (TDECs) were stimulated with fibroblast growth factor 1 (FGF1) or VEGF and formed more tubes compared with untreated, whereas cells treated with Sulforaphane had less tube formation. Silencing SNAI1 significantly attenuated tube formation accompanied by decreased CD31, CD34, and VWF expression in TDECs compared with control. In contrast, overexpression of Snai1 led to more CD31, CD34, and VWF expression and tube formation. To determine if the observed effects of SNAI1 on tube formation was a global phenomenon, the same assay was conducted in normal mesenchymal stem cells (MSCs). SNAI1 silencing did not have any effect on tube formation in MSCs. The expression of TIMP2, ENG, and HIF1A was up-regulated 3-fold or higher after silencing SNAI1, and ID1, VEGFA, PLG, LECT1, HPSE were shown down-regulated. Taken together, our study elucidates an important role of EMT inducer Snai1 in regulating tumor neoangiogenesis, suggesting a potential therapeutic target for overcoming tumor EMT.

8.
Adv Mater ; 31(1): e1803514, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30368915

RESUMO

Following the rejuvenation of 3D organic-inorganic hybrid perovskites, like CH3 NH3 PbI3 , (quasi)-2D Ruddlesden-Popper soft halide perovskites R2 An -1 Pbn X3 n +1 have recently become another focus in the optoelectronic and photovoltaic device community. Although quasi-2D perovskites were first introduced to stabilize optoelectronic/photovoltaic devices against moisture, more interesting properties and device applications, such as solar cells, light-emitting diodes, white-light emitters, lasers, and polaritonic emission, have followed. While delicate engineering design has pushed the performance of various devices forward remarkably, understanding of the fundamental properties, especially the charge-transfer process, electron-phonon interactions, and the growth mechanism in (quasi)-2D halide perovskites, remains limited and even controversial. Here, after reviewing the current understanding and the nexus between optoelectronic/photovoltaic properties of 2D and 3D halide perovskites, the growth mechanisms, charge-transfer processes, vibrational properties, and electron-phonon interactions of soft halide perovskites, mainly in quasi-2D systems, are discussed. It is suggested that single-crystal-based studies are needed to deepen the understanding of the aforementioned fundamental properties, and will eventually contribute to device performance.

9.
J Gastroenterol Hepatol ; 34(1): 284-292, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30144357

RESUMO

BACKGROUND AND AIM: ß-Arrestins (ß-arrs) are regulators and mediators of G protein-coupled receptor signaling that are functionally involved in inflammation. Nuclear factor-κB p65 (NF-κBp65) activation has been observed early in the onset of pancreatitis. However, the effect of ß-arrs in acute pancreatitis (AP) is unclear. The aim of this study is to investigate whether ß-arrs are involved in AP through activation of NF-κBp65. METHODS: Acute pancreatitis was induced by either caerulein injection or choline-deficient supplemented with ethionine diet (CDE). ß-arr1 wild-type and ß-arr1 knockout mice were used in the experiment. The survival rate was calculated in the CDE model mice. Histological and western blot analyses were performed in the caerulein model. Inflammatory mediators were detected by real-time polymerase chain reaction in the caerulein-induced AP mice. Furthermore, AR42J and PANC-1 cell lines were used to further study the effects of ß-arr1 in caerulein-induced pancreatic cells. RESULTS: ß-Arr1 but not ß-arr2 is significantly downregulated in caerulein-induced AP in mice. Targeted deletion of ß-arr1 notably upregulated expression of the pancreatic inflammatory mediators including tumor necrosis factor α and interleukin 1ß as well as interleukin 6 and aggravated AP in caerulein-induced mice. ß-Arr1 deficiency increased mortality in mice with CDE-induced AP. Further, ß-arr1 deficiency enhanced caerulein-induced phosphorylation of NF-κBp65 both in vivo and in vitro. CONCLUSION: ß-Arr1 alleviates AP via repression of NF-κBp65 activation, and it is a potentially therapeutic target for AP.


Assuntos
Pancreatite/genética , Pancreatite/metabolismo , Fator de Transcrição RelA/antagonistas & inibidores , Fator de Transcrição RelA/metabolismo , beta-Arrestina 1/genética , beta-Arrestina 1/metabolismo , Doença Aguda , Animais , Linhagem Celular Tumoral , Ceruletídeo , Deficiência de Colina/complicações , Modelos Animais de Doenças , Regulação para Baixo , Etionina , Feminino , Humanos , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Camundongos Knockout , Pancreatite/induzido quimicamente , Pancreatite/patologia , Fosforilação , Taxa de Sobrevida , Fator de Necrose Tumoral alfa/metabolismo
10.
Phys Chem Chem Phys ; 20(17): 12272-12277, 2018 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29687804

RESUMO

The evaporation of nanoscale water films on surfaces affects many processes in nature and industry. Using molecular dynamics (MD) simulations, we show the evaporation of a nanoscale water film on a uniformly complete wetting surface at different temperatures. With the increase in temperature, the growth of the water evaporation rate becomes slow. Analyses show that the hydrogen bond (H-bond) lifetimes and orientational autocorrelation times of the outermost water film decrease slowly with the increase in temperature. Compared to a thicker water film, the H-bond lifetimes and orientational autocorrelation times of a monolayer water film are much slower. This suggests that the lower evaporation rate of the monolayer water film on a uniformly complete wetting surface may be caused by the constriction of the water rotation due to the substrate. This finding may be helpful for controlling nanoscale water evaporation within a certain range of temperatures.

11.
IEEE Trans Cybern ; 48(8): 2402-2415, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28858822

RESUMO

The issue of single sample per person (SSPP) face recognition has attracted more and more attention in recent years. Patch/local-based algorithm is one of the most popular categories to address the issue, as patch/local features are robust to face image variations. However, the global discriminative information is ignored in patch/local-based algorithm, which is crucial to recognize the nondiscriminative region of face images. To make the best of the advantage of both local information and global information, a novel two-layer local-to-global feature learning framework is proposed to address SSPP face recognition. In the first layer, the objective-oriented local features are learned by a patch-based fuzzy rough set feature selection strategy. The obtained local features are not only robust to the image variations, but also usable to preserve the discrimination ability of original patches. Global structural information is extracted from local features by a sparse autoencoder in the second layer, which reduces the negative effect of nondiscriminative regions. Besides, the proposed framework is a shallow network, which avoids the over-fitting caused by using multilayer network to address SSPP problem. The experimental results have shown that the proposed local-to-global feature learning framework can achieve superior performance than other state-of-the-art feature learning algorithms for SSPP face recognition.


Assuntos
Identificação Biométrica/métodos , Face/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Algoritmos , Bases de Dados Factuais , Feminino , Lógica Fuzzy , Humanos , Masculino
12.
Nano Lett ; 16(12): 7974-7981, 2016 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-27960450

RESUMO

One-dimensional nanoscale epitaxial arrays serve as a great model in studying fundamental physics and for emerging applications. With an increasing focus laid on the Cs-based inorganic halide perovskite out of its outstanding material stability, we have applied vapor phase epitaxy to grow well aligned horizontal CsPbX3 (X: Cl, Br, or I or their mixed) nanowire arrays in large scale on mica substrate. The as-grown nanowire features a triangular prism morphology with typical length ranging from a few tens of micrometers to a few millimeters. Structural analysis reveals that the wire arrays follow the symmetry of mica substrate through incommensurate epitaxy, paving a way for a universally applicable method to grow a broad family of halide perovskite materials. The unique photon transport in the one-dimensional structure has been studied in the all-inorganic Cs-based perovskite wires via temperature dependent and spatially resolved photoluminescence. Epitaxy of well oriented wire arrays in halide perovskite would be a promising direction for enabling the circuit-level applications of halide perovskite in high-performance electro-optics and optoelectronics.

13.
Chem Commun (Camb) ; 52(4): 796-9, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26567464

RESUMO

A novel and straightforward strategy for heptafluoroisopropylation of arylboronic acids at room temperature has been developed. This method, directly using commercial available hexafluoropropene (HFP) as the starting material, provides a new way to synthesize a variety of synthetically useful heptafluoroisopropylated arenes.

14.
Sci Rep ; 5: 18707, 2015 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-26687924

RESUMO

Transition metal oxides host an array of exotic electronic phases, including superconductivity, ferroelectricity, quantum spin liquid and Mott insulators. Their extreme sensitivity to external stimuli enables various routes to manipulate the ground state, which greatly improves our understanding of the physics involved. Here, we report the competition between strain and dimensionality effects on the phase evolution in high quality NdNiO3 films down to several unit cells. While both compressive and tensile strains increase the Ni 3d band width and favor the metallic phase, reducing dimensionality, on the other hand, decreases the covalent band width and favors the insulating phase in NdNiO3. The experimental observations are well supported by ab initio calculations and improve our understanding of the electronic behavior in strongly correlated electron systems.

15.
ISRN Oncol ; 2013: 645817, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24224098

RESUMO

Objective. The effect of extracted crude soybean saponins on preneoplastic lesions, aberrant crypt foci (ACF), and the related mechanism were investigated. Research Methods and Procedures. Rats were assigned into five groups according to different doses of extracted crude soybean saponins and received 1,2-dimethylhydrazine (DMH) injection in week 5. In week 15, all rats were sacrificed. The number of ACFs, the cyclooxygenase-2 (COX-2) protein expression, the level of prostaglandins E2 (PGE2), and the activity of ß -glucuronidase were examined. Results. Results revealed that the consumption of extracted crude soybean saponins decreased the number of ACFs and the activity of ß -glucuronidase in rats, while the expression of COX-2 protein and PGE2 level were not affected. Conclusions. Soybean saponins were effective in inhibiting colon cancer by downregulating the activity of ß -glucuronidase in colonic mucosa but not the COX-2 protein expression and PGE2 level.

16.
Artigo em Inglês | MEDLINE | ID: mdl-21680231

RESUMO

In this paper, the chlorophyll derivatives, metallochlorophyllin (Chl-M) (M=Fe, Zn and Cu) including chlorophyllin iron (Chl-Fe), chlorophyllin zinc (Chl-Zn) and chlorophyllin copper (Chl-Cu), were adopted as sonosensitizers to combine with ultrasonic irradiation, and the sonodynamic damage of bovine serum albumin (BSA) was investigated. At first, the interaction of Chl-M with BSA was studied by fluorescence spectroscopy. The results show that the quenching mechanism belongs to a static process and among them the affinity of Chl-Fe to BSA is the most obvious. Then, some influence factors on the sonodynamic damage of BSA molecules in the presence of Chl-M under ultrasonic irradiation were also studied. Synchronous fluorescence spectra show that the binding and damage sites of Chl-M to BSA molecule are mainly on the tryptophan (Trp) residues. The generation of ROS in Chl-M sonodynamic process is estimated by the method of Oxidation-Extraction Spectrometry (OEP). This paper may offer some valuable references for the study of the sonodynamic activity of Chl-M and the effect of the central metals. Synchronously, it contributes to the application of Chl-M in SDT for tumor treatment.


Assuntos
Clorofilídios/metabolismo , Clorofilídios/efeitos da radiação , Ligação Proteica/efeitos da radiação , Soroalbumina Bovina/metabolismo , Soroalbumina Bovina/efeitos da radiação , Ultrassom , Animais , Antimutagênicos/metabolismo , Antimutagênicos/efeitos da radiação , Bovinos , Humanos , Compostos Organometálicos/metabolismo , Compostos Organometálicos/efeitos da radiação , Protetores contra Radiação/metabolismo , Protetores contra Radiação/efeitos da radiação , Espectrometria de Fluorescência
17.
J Hazard Mater ; 192(2): 786-93, 2011 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-21700389

RESUMO

In the present work, the rutile, anatase and mixed (rutile and anatase) crystal phase TiO(2) powders were irradiated by ultrasound and solar light, respectively, and the generation of reactive oxygen species (ROS) were detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). The DPCO can be extracted by the mixed solvent of benzene and carbon tetrachloride and the extract liquors display an obvious absorption peak around 563nm. In addition, the influences of (ultrasonic or solar light) irradiation time, TiO(2) addition amount and DPCI concentration on the quantities of generated ROS were also reviewed. The kinds of generated ROS were determined by using several radical scavengers. At last, the researches on the sonocatalytic and photocatalytic degradation of several organic dyes were also performed. It is wished that this paper might offer some important subjects for broadening the applications of sonocatalytic and photocatalytic technologies.


Assuntos
Corantes/química , Compostos Orgânicos/química , Espécies Reativas de Oxigênio/química , Titânio/química , Difração de Raios X
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 79(5): 1099-104, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21620761

RESUMO

In order to examine the mechanism and process of sonodynamic reaction, the chlorophyllin magnesium (Chl-Mg) acting as a sonosensitizer was irradiated by ultrasound, and the generation of reactive oxygen species (ROS) were detected by the method of oxidation-extraction spectrometry (OES). That is, under ultrasonic irradiation in the presence of Chl-Mg, the 1,5-diphenyl carbazide (DPCI) is oxidized by generated ROS into 1,5-diphenyl carbazone (DPCO), which can be extracted by mixed organic solvent and display a obvious visible absorption at 563 nm wavelength. Besides, the generation conditions of ROS were also reviewed. The results demonstrated that the quantities of generated ROS increased with the increase of ultrasonic irradiation time, Chl-Mg concentration and DPCI concentration. Finally, several radical scavengers (l-Histidine (His), 2,6-Di-tert-butyl-methylphenol (BHT) and Vitamin C (VC)) were used to determine the kind of the generated ROS. It was found that at least the hydroxyl radical (OH) and singlet oxygen (1O2) were generated in the presence of Chl-Mg under ultrasonic irradiation. It is wish that this paper might offer some valuable references for the study on the mechanism of SDT and the application of Chl-Mg in tumor treatment.


Assuntos
Clorofilídios/efeitos da radiação , Magnésio/efeitos da radiação , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/efeitos da radiação , Ultrassom , Antioxidantes/química , Antioxidantes/farmacologia , Ácido Ascórbico/química , Ácido Ascórbico/farmacologia , Hidroxitolueno Butilado , Clorofilídios/química , Depuradores de Radicais Livres/farmacologia , Histidina/química , Radical Hidroxila , Magnésio/química , Oxirredução , Fenóis/química , Fenóis/farmacologia , Análise Espectral
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 78(4): 1278-86, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21295513

RESUMO

In this work, three o-Vanillin Schiff Bases (o-VSB: o-Vanillin-D-Phenylalanine (o-VDP), o-Vanillin-L-Tyrosine (o-VLT) and o-Vanillin-L-Levodopa (o-VLL)) with alanine constituent were synthesized by direct reflux method in ethanol solution, and then were used to study the interaction to bovine serum albumin (BSA) molecules by fluorescence spectroscopy. Based on the fluorescence quenching calculation, the bimolecular quenching constant (K(q)), apparent quenching constant (K(sv)), effective binding constant (K(A)) and corresponding dissociation constant (K(D)) as well as binding site number (n) were obtained. In addition, the binding distance (r) was also calculated according to Foster's non-radioactive energy transfer theory. The results show that these three o-VSB can efficiently bind to BSA molecules, but the binding array order is o-VDP-BSA>o-VLT-BSA>o-VLL-BSA. Synchronous fluorescence spectroscopy indicates that the o-VDP is more accessibility to tryptophan (Trp) residues of BSA molecules than to tyrosine (Tyr) residues. Nevertheless, the o-VLT and o-VLL are more accessibility to Tyr residues than to Trp residues.


Assuntos
Benzaldeídos/química , Levodopa/química , Fenilalanina/química , Bases de Schiff/química , Soroalbumina Bovina/química , Tirosina/química , Animais , Bovinos , Dopaminérgicos/química , Estrutura Molecular , Bases de Schiff/metabolismo , Soroalbumina Bovina/metabolismo
20.
Ultrason Sonochem ; 18(5): 1028-34, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21236719

RESUMO

In this paper, in order to examine the mechanisms of sonodynamic and photodynamic reactions, the chlorophyllin metal (Chl-M (M=Fe, Mg and Cu)) complexes were irradiated by ultrasound (US) and visible-light (VL), respectively, and the generation of reactive oxygen species (ROS) were detected by the method of Oxidation-Extraction Spectrometry (OES). That is, the 1,5-diphenyl carbazide (DPCI) is oxidized by the generated ROS into 1,5-diphenyl carbazone (DPCO), which can display a various visible absorption around 563 nm wavelength. Besides, some influence parameters on the generation of ROS were also reviewed. The results demonstrated an apparent synergistic effect of Chl-M and ultrasonic or visible-light irradiation for the generation of ROS. Moreover, the quantities of generated ROS increase with the increase of (ultrasonic or visible-light) irradiation time and Chl-M (M=Fe, Mg and Cu) concentration. Finally, several quenchers were used to determine the kind of the generated ROS. It is wished that this paper might offer some valuable references for the study on the sonodynamic therapy (SDT) and photodynamic therapy (PDT) mechanisms and the application of Chl-M in tumor treatment.


Assuntos
Clorofilídios/química , Clorofilídios/efeitos da radiação , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/efeitos da radiação , Sonicação/métodos , Luz , Doses de Radiação
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