Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
2.
Nutr Metab Cardiovasc Dis ; 28(1): 28-34, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29162363

RESUMO

BACKGROUND AND AIMS: Dyslipidemia predicts higher risk of coronary events and stroke and might be associated with cerebral small vessel disease (SVD). Previous studies linking blood lipids and SVD have yielded inconsistent results, which may be attributable to sex differences in lipids metabolism. The aim of this study was to investigate the relationships between blood lipids and SVD in neurologically healthy men and women. METHODS AND RESULTS: Consecutive 817 people aged 50 years or more were enrolled and underwent magnetic resonance imaging scans to evaluate the periventricular white matter lesions (PVWMLs), deep white matter lesions (DWMLs) and silent brain infarction (SBI). Fasting total cholesterol, triglyceride, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol, apolipoprotein A-1 (apoA-1) and apolipoprotein B were assessed. Multivariable logistic regression analyses were performed to determine the associations of blood lipids with PVWMLs, DWMLs and SBI. HDL-C (for PVWMLs: OR 0.36, 95% CI 0.19-0.71; for DWMLs: OR 0.35, 95% CI 0.20-0.63) and apoA-1 (for PVWMLs: OR 0.27, 95% CI 0.11-0.66; for DWMLs: OR 0.22, 95% CI 0.10-0.48) were inversely associated with the severity of PVWMLs and DWMLs in women but not in men after adjustment for age, hypertension, diabetes, current smoking, daily drinking, body mass index and uric acid. Additionally, no blood lipids were significantly associated with SBI. CONCLUSIONS: Our findings demonstrate that sex differences may exist in the associations between lipids and SVD. HDL-C and apoA-1 levels were inversely associated with the severity of PVWMLs and DWMLs in women.


Assuntos
Infarto Encefálico/sangue , Doenças de Pequenos Vasos Cerebrais/sangue , Dislipidemias/sangue , Leucoencefalopatias/sangue , Lipídeos/sangue , Idoso , Apolipoproteína A-I/sangue , Biomarcadores/sangue , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/etiologia , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/etiologia , HDL-Colesterol/sangue , Estudos Transversais , Dislipidemias/complicações , Dislipidemias/diagnóstico , Feminino , Humanos , Leucoencefalopatias/diagnóstico , Leucoencefalopatias/etiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Fatores Sexuais
4.
Nanotechnology ; 25(36): 365602, 2014 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-25121634

RESUMO

In this study, we present a facile one-step method to synthesize graphene-Au nanoparticle (NP) hybrid materials by using HAuCl4-loaded poly(styrene)-block-poly(2-vinylpyridine) (PS-P2VP) micelles as solid carbon sources. N-doped graphene with controllable thickness can be grown from PS-P2VP micelles covered by a Ni capping layer by an annealing process; simultaneously, the HAuCl4 in the micelles were reduced into Au NPs under a reductive atmosphere to form Au NPs on graphene. The decoration of Au NPs leads to an obviously enhanced electrical conductivity and a slightly increased work function of graphene due to the electron transfer effect. The graphene-Au NP hybrid materials also exhibit a localized surface plasmon resonance feature of Au NPs. This work provides a novel and accessible route for the one-step synthesis of graphene-Au NP hybrid materials with high quality, which might be useful for future applications in optoelectronic devices.

5.
Eur J Neurol ; 21(7): 1032-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24698428

RESUMO

BACKGROUND AND PURPOSE: Metabolic syndrome (MetS) has been reported to be associated with silent lacunar infarction, which is highly related to white matter lesions (WMLs). However, little is known about the relationship between MetS and the prevalence of WMLs. The association between MetS, its components and WMLs in middle-aged and elderly patients was investigated. METHODS: Consecutive patients aged 50 years and older were prospectively enrolled in this study. All participants underwent magnetic resonance imaging scans to assess the presence and severity of WMLs. The MetS was defined according to the updated National Cholesterol Education Program's Adult Treatment Panel III criteria. Multivariate logistic regression analyses were performed to examine the relationship between MetS, its components and WMLs. RESULTS: A total of 852 patients were enrolled in the study. MetS was present in 38.4%. MetS was associated with an increased risk of periventricular WMLs (PVWMLs) and deep WMLs (DWMLs) after multivariable adjustment (odds ratio 3.21, 95% confidence interval 2.26-4.55 for PVWMLs; odds ratio 2.93, 95% confidence interval 2.09-4.09 for DWMLs). Amongst MetS components, elevated blood pressure, elevated fasting blood glucose and low high density lipoprotein cholesterol were associated with PVWMLs, whilst elevated blood pressure and low high density lipoprotein cholesterol were related to DWMLs. CONCLUSIONS: Our findings demonstrate that MetS is associated with the prevalence of PVWMLs and DWMLs independent of other risk factors in middle-aged and elderly patients. The association between MetS as a cluster and WMLs was not driven by MetS components.


Assuntos
Leucoencefalopatias/epidemiologia , Leucomalácia Periventricular/epidemiologia , Síndrome Metabólica/epidemiologia , Idoso , Comorbidade , Feminino , Humanos , Leucoencefalopatias/patologia , Leucomalácia Periventricular/patologia , Imageamento por Ressonância Magnética , Masculino , Síndrome Metabólica/patologia , Pessoa de Meia-Idade
6.
ACS Appl Mater Interfaces ; 6(4): 2639-46, 2014 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-24467526

RESUMO

Highly elongated BiFeO3 is epitaxially grown on hexagonal sapphire(0001) substrate within a rather narrow synthesis window. Both X-ray reciprocal space maps and Raman characterizations reveal that it is of true tetragonal symmetry but not the commonly observed MC type monoclinic structure. The tetragonal BiFeO3 film exhibits an island growth mode, with the island edges oriented parallel to the ⟨10-10⟩ and ⟨12-30⟩ directions of the sapphire substrate. With increasing deposition time, a transition from square island to elongated island and then to a continuous film is observed. The metastable tetragonal phase can remain on the substrate without relaxation to the thermally stable rhombohedral phase up to a critical thickness of 450 nm, providing an exciting opportunity for practicable lead-free ferroelectrics. These results facilitate a better understanding of the phase stability of BiFeO3 polymorphs and enrich the knowledge about the heteroepitaxial growth mechanism of functional oxides on symmetry-mismatched substrates.

7.
J Nanosci Nanotechnol ; 13(2): 1101-5, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23646580

RESUMO

In this work, periodic arrays of various ZnO nanostructures were fabricated on both Si and GaN substrates via a facile hydrothermal process. To realize the site-specific growth, two kinds of masks were introduced. The polystyrene (PS) microsphere self-assembled monolayer (SAM) was employed as the mask to create a patterned seed layer to guide the growth of ZnO nanostructures. However, the resulting ZnO nanostructures are non-equidistant, and the diameter of the ZnO nanostructures is uncontrollable. As an alternative, TiO2 sol was used to replicate the PS microsphere SAM, and the inverted SAM (ISAM) mask was obtained by extracting the PS microspheres with toluene. By using the ISAM mask, the hexagonal periodic array of ZnO nanostructures with high uniformity were readily produced. Furthermore, the effect of the underlying substrates on the morphology of ZnO nanostructures has been investigated. It is found that the highly ordered and vertically aligned ZnO nanorods epitaxially grow on the GaN substrate, while the ZnO nanoflowers on Si substrates are random oriented.

8.
Genet Mol Res ; 11(3): 3105-14, 2012 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-23007988

RESUMO

The biological effects of transfection of an adeno-associated virus (AAV) vector with bone morphogenetic proteins 4 and 7 (BMP-4/7) fusion gene (AAV-BMP-4/7) were determined in rabbit bone marrow stromal cells (BMSCs). BMP-4 and BMP-7 genes were obtained through one-step reverse transcriptase polymerase chain reaction from human placental cells. The BMP-4/7 fusion gene was then generated through recombination. Rabbit BMSCs were transfected with the recombinant AAV vectors carrying AAV-BMP-4/7 with multiplicity of infection values. Cell growth curves were drawn to evaluate the biological effects of AAV-BMP-4/7 on cell activity. The transfection efficiency was measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The ossification of cells was evaluated by observing alkaline phosphatase (ALP) and osteocalcin (OC) activity after transfection for 7 and 14 days. The cells were then transfected with AAV-BMP-4/7 and AAV-enhanced green fluorescent protein. We successfully constructed the recombinant adeno-associated virus with the BMP-4/7 fusion gene. The transfection efficiency of AAV-BMP-4/7 was approximately 72% without significant biological effects on cell activity. Cell ossification was significant after transfection with AAV-BMP-4/7. The 1 x 10(5) vg/cell multiplicity of infection value of transfection efficiency was more than 5 x 10(4) vg/cell (59.38%). Significantly higher ALP and OC activity occurred in the AAV-BMP-4/7 transfection groups than in the AAV-enhanced green fluorescent protein groups (t(ALP) = 896.88, P < 0.001; t(OC) = 543.24, P < 0.01). The AAV-BMP-4/7 fusion gene can highly efficient transfect rabbit BMSCs cultured in vitro and it has significant ossification activity.


Assuntos
Proteína Morfogenética Óssea 4/genética , Proteína Morfogenética Óssea 7/genética , Dependovirus/metabolismo , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Proteínas Recombinantes de Fusão/genética , Recombinação Genética/genética , Fosfatase Alcalina/metabolismo , Animais , Proliferação de Células , Forma Celular , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/enzimologia , Osteocalcina/metabolismo , Plasmídeos/metabolismo , Coelhos , Proteínas Recombinantes de Fusão/metabolismo , Transfecção
9.
J Bone Joint Surg Br ; 94(8): 1077-85, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22844049

RESUMO

Follow-up radiographs are usually used as the reference standard for the diagnosis of suspected scaphoid fractures. However, these are prone to errors in interpretation. We performed a meta-analysis of 30 clinical studies on the diagnosis of suspected scaphoid fractures, in which agreement data between any of follow-up radiographs, bone scintigraphy, magnetic resonance (MR) imaging, or CT could be obtained, and combined this with latent class analysis to infer the accuracy of these tests on the diagnosis of suspected scaphoid fractures in the absence of an established standard. The estimated sensitivity and specificity were respectively 91.1% and 99.8% for follow-up radiographs, 97.8% and 93.5% for bone scintigraphy, 97.7% and 99.8% for MRI, and 85.2% and 99.5% for CT. The results were generally robust in multiple sensitivity analyses. There was large between-study heterogeneity for the sensitivity of follow-up radiographs and CT, and imprecision about their sensitivity estimates. If we acknowledge the lack of a reference standard for diagnosing suspected scaphoid fractures, MRI is the most accurate test; follow-up radiographs and CT may be less sensitive, and bone scintigraphy less specific.


Assuntos
Fraturas Ósseas/diagnóstico , Osso Escafoide/lesões , Humanos , Imageamento por Ressonância Magnética , Cintilografia , Osso Escafoide/diagnóstico por imagem , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
10.
ACS Appl Mater Interfaces ; 3(11): 4388-95, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21967127

RESUMO

This article presents a facile and effective approach to the controllable growth of highly ordered and vertically aligned ZnO nanorod arrays on the GaN substrate via a hydrothermal route by using the TiO(2) ring template deriving from the polystyrene microsphere self-assembled monolayer. The size of TiO(2) ring template can be flexibly tuned from 50 to 400 nm for the 500 nm polystyrene microspheres by varying the time of reactive ion etching and the concentration of TiO(2) sol. As a result, the diameter of the individual ZnO nanorods can be potentially tuned over a wide range. The combination of several characterization techniques has demonstrated that the ordered ZnO nanorods are highly uniform in diameter and height with perfect alignment and are epitaxially grown along [0001] direction. This work provides a novel and accessible route to prepare oriented and aligned ZnO nanorod arrays with high crystalline quality.

11.
J Nanosci Nanotechnol ; 11(12): 10548-52, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22408945

RESUMO

The [FePt]94Au6 and [FePt]90Ag10 nanoparticle arrays were synthesized on Si substrates by a reverse micellar method, combined with plasma treatment and in-situ deposition of a SiO2 overlayer, and the post annealing step was performed to drive the face-centered cubic to tetragonal phase transition. These FePt nanoparticles exhibit a quasi-hexagonal order with tailored inter-particle spacing and particle size. The effects of the Ag and Au on the structural and magnetic properties of FePt were investigated. The results indicate that both Au and Ag additives can remarkably enhance the coercivity and reduce the ordering temperature, however, the optimum composition is different for them. The optimum composition is determined to be [FePt]94Au6 and [FePt]90Ag10, respectively, for which the ordering temperature of FePt nanoparticles is reduced by -100 degrees C. After 600 degrees C annealing, the [FePt]94Au6 and [FePt]90Ag10 nanoparticles are totally ferromagnetic with apparent larger coercivities of -7.0 kOe, which is about 3.8 kOe larger than that of the pure FePt nanoparticles. The mechanism of the chemical ordering acceleration may be attributed to the defects and strains caused by the Au/Ag additives.

12.
ACS Appl Mater Interfaces ; 2(6): 1780-4, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20499898

RESUMO

Wurtzite ZnO has many potential applications in optoelectronic devices, and the hydrogenated ZnO exhibits excellent photoelectronic properties compared to undoped ZnO; however, the structure of H-related defects is still unclear. In this article, the effects of hydrogen-plasma treatment and subsequent annealing on the electrical and optical properties of ZnO films were investigated by a combination of Hall measurement, Raman scattering, and photoluminescence. It is found that two types of hydrogen-related defects, namely, the interstitial hydrogen located at the bond-centered (H(BC)) and the hydrogen trapped at a O vacancy (H(O)), are responsible for the n-type background conductivity of ZnO films. Besides introducing two hydrogen-related donor states, the incorporated hydrogen passivates defects at grain boundaries. With increasing annealing temperatures, the unstable H(BC) atoms gradually diffuse out of the ZnO films and part of them are converted into H(O), which gives rise to two anomalous Raman peaks at 275 and 510 cm(-1). These results help to clarify the relationship between the hydrogen-related defects in ZnO described in various studies and the free carriers that are produced by the introduction of hydrogen.

13.
Nanoscale Res Lett ; 4(10): 1121-1125, 2009 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-20596433

RESUMO

The Pt nanoparticles (NPs), which posses the wider tunable localized-surface-plasmon (LSP) energy varying from deep ultraviolet to visible region depending on their morphology, were prepared by annealing Pt thin films with different initial mass-thicknesses. A sixfold enhancement of the 357 nm forward emission of ZnMgO was observed after capping with Pt NPs, which is due to the resonance coupling between the LSP of Pt NPs and the band-gap emission of ZnMgO. The other factors affecting the ultraviolet emission of ZnMgO, such as emission from Pt itself and light multi-scattering at the interface, were also discussed. These results indicate that Pt NPs can be used to enhance the ultraviolet emission through the LSP coupling for various wide band-gap semiconductors.

14.
Nanotechnology ; 19(13): 135704, 2008 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-19636158

RESUMO

Ordered arrays of FePt nanoparticles were prepared using a diblock polymer micellar method combined with plasma treatment. Rutherford backscattering spectroscopy analyses reveal that the molar ratios of Fe to Pt in metal-salt-loaded micelles deviate from those when metal precursors are added, and that the plasma treatment processes have little influence upon the compositions of the resulting FePt nanoparticles. The results from Fourier transform infrared spectroscopy show that the maximum loadings of FeCl(3) and H(2)PtCl(6) inside poly(styrene)-poly(4-vinylpyridine) micelles are different. The composition deviation of FePt nanoparticles is attributed to the fact that one FeCl(3) molecule coordinates with a single 4-vinylpyridine (4VP) unit, while two neighboring and uncomplexed 4VP units are required for one H(2)PtCl(6) molecule. Additionally, we demonstrate that the center-to-center distances of the neighboring FePt nanoparticles can also be tuned by varying the drawing velocity.

15.
J Hand Surg Br ; 31(5): 547-55, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16930788

RESUMO

A randomised, double-blinded, controlled trial was performed to compare traditional digital blocks with single subcutaneous palmar injection blocks at the base of the finger. A search for randomised controlled trials of digital blocks through MEDLINE, EMBASE, Cochrane Controlled Trials Register and CBM was conducted and a meta-analysis including the current trial was performed. The current trial showed no difference between traditional digital blocks and single subcutaneous palmar injection bocks at the base of the finger in respect of injection pain and time to anaesthesia. The meta-analysis suggests that traditional digital blocks and single subcutaneous palmar injection blocks are similar with regard to injection pain and are less painful than the transthecal digital block. The palmar techniques, including single subcutaneous palmar block and transthecal block, carry a risk of not anaesthetising the dorsum of the digit adequately, particularly the dorsum of the thumb and the proximal phalanx of the fingers.


Assuntos
Traumatismos dos Dedos/cirurgia , Bloqueio Nervoso/métodos , Adolescente , Adulto , Anestésicos Locais/administração & dosagem , Método Duplo-Cego , Feminino , Humanos , Injeções Subcutâneas , Lidocaína/administração & dosagem , Masculino , Pessoa de Meia-Idade , Medição da Dor , Ensaios Clínicos Controlados Aleatórios como Assunto
16.
Clin Nephrol ; 30(6): 320-9, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3243041

RESUMO

Between 1973 and 1986, 109 patients with membranous nephropathy have been evaluated with respect to clinical presentation, pathological features and factors determining prognosis. Secondary disease was present in 21, and a further 21 were lost or followed for less than 12 months. The remaining 67 with idiopathic membranous nephropathy were allotted to one of three groups. Group 0 (26 patients) received no active treatment, Group 1 (12 patients) a combination of cyclophosphamide, dipyridamole and warfarin, and Group 2 (21 patients) high dose alternate day prednisolone therapy. Eight patients received other treatment or presented with end stage renal disease. No significant difference in outcome could be detected between the groups. Remission rates were equivalent as were numbers of patients judged as having progressive disease. There was no statistical difference with respect to duration of nephrotic syndrome, plasma creatinine at the end of study and change in plasma creatinine. No demonstrable benefit was obtained in predicting the outcome of disease or response to treatment from conventional pathological grading of stages I to IV as approximately equal numbers of each stage fell into good and bad categories of outcome. Similarly unusual histological features such as mesangial proliferation and immunofluorescence for deposits other than IgG and C3 were not helpful. A different approach to treatment of idiopathic membranous nephropathy is strongly recommended.


Assuntos
Ciclofosfamida/administração & dosagem , Dipiridamol/administração & dosagem , Glomerulonefrite Membranosa/tratamento farmacológico , Prednisolona/administração & dosagem , Varfarina/administração & dosagem , Adolescente , Adulto , Idoso , Biópsia , Ciclofosfamida/uso terapêutico , Dipiridamol/uso terapêutico , Quimioterapia Combinada , Feminino , Seguimentos , Glomerulonefrite Membranosa/etiologia , Humanos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Prednisolona/uso terapêutico , Varfarina/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...