Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Thromb Haemost ; 112(6): 1198-208, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25182660

RESUMO

Adjunctive use of phosphodiesterase (PDE) inhibitor can enhance antiplatelet and vasoprotective properties in patients with cardiovascular disease. The aim of this study was to evaluate the impact of PDE5 inhibitor dipyridamole on platelet function in stented patients with high platelet reactivity (HPR) during dual antiplatelet therapy (DAPT) with aspirin and clopidogrel. Patients with HPR after 600-mg clopidogrel loading were randomly assigned to adjunctive dipyridamole 75 mg twice daily to standard DAPT (DIP group; n = 45) or double-dose clopidogrel of 150 mg daily (DOUBLE group; n = 46) for 30 days. Platelet function was assessed at baseline and 30-day follow-up with platelet reactivity index (PRI) by vasodilator-stimulated phosphoprotein-phosphorylation (VASP-P) assay and platelet aggregation (PA) by light transmittance aggregometry (LTA). Primary endpoint was PRI at 30-day follow-up. HPR was defined as PRI > 50%. Baseline platelet function did not differ between the groups. Following 30-day therapy, platelet function was significantly reduced in the DIP and DOUBLE groups (all p-values ≤ 0.004 and ≤ 0.068, respectively). PRI values were not significantly different between the two groups (mean difference: 3.1%; 95% confidence interval: -2.8% to 9.0%: p = 0.295). PA values and prevalence of HPR were similar between the groups. However, a significant number of patients still exhibited HPR in the DIP (75.6%) and DOUBLE (67.4%) groups. In conclusion, among stented HPR patients, adding dipyridamole to DAPT does not reduce platelet reactivity and prevalence of HPR compared with double-dose clopidogrel therapy, and therefore both strategies are inadequate to overcome HPR.


Assuntos
Aspirina/uso terapêutico , Plaquetas/efeitos dos fármacos , Dipiridamol/uso terapêutico , Resistência a Medicamentos , Intervenção Coronária Percutânea , Inibidores da Fosfodiesterase 5/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Ticlopidina/análogos & derivados , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Idoso , Aspirina/efeitos adversos , Biomarcadores/sangue , Plaquetas/metabolismo , Moléculas de Adesão Celular/sangue , Clopidogrel , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP3A/genética , Dipiridamol/efeitos adversos , Quimioterapia Combinada , Feminino , Genótipo , Humanos , Masculino , Proteínas dos Microfilamentos/sangue , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/instrumentação , Inibidores da Fosfodiesterase 5/efeitos adversos , Fosfoproteínas/sangue , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/efeitos adversos , Testes de Função Plaquetária , Estudos Prospectivos , República da Coreia , Stents , Ticlopidina/efeitos adversos , Ticlopidina/uso terapêutico , Fatores de Tempo , Resultado do Tratamento
2.
J Phys Condens Matter ; 25(25): 256005, 2013 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-23733006

RESUMO

We examined the distribution of Co ions in ferromagnetic n-type Zn(1-x)Co(x)O semiconducting films with Co concentrations of 0.0-0.07 using x-ray absorption fine structure (XAFS) measurements at the Co and Zn K edges. Extended XAFS (EXAFS) revealed that Co ions mainly occupied the zinc sites in the films. X-ray absorption near edge structure (XANES) spectra demonstrated that the pre-edge peak of the Co K edge was substantially affected by the second neighboring Co ions in the zinc sites due to their environmental potential distortion. From the pre-edge peak and EXAFS analysis using ab initio calculations, we found that Co ions uniformly occupied the zinc sites of the Zn0.93Co0.07O film, whereas the Co ions of the Zn0.97Co0.03O and Zn0.95Co0.05O films were substituted at the zinc sites with a non-uniform distribution. The ferromagnetic properties of the Zn0.93Co0.07O film may be induced by direct interaction between the magnetic dipoles of the Co ions with a mean distance of 4.3 Å, or by the Co conduction-electron mediation.

4.
J Thromb Haemost ; 10(8): 1685-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22612904
5.
J Nanosci Nanotechnol ; 11(8): 7420-3, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22103210

RESUMO

This study examined the micro-structural and electrical properties of N+-ion-implanted ZnO nanorods. Nitrogen ions with energies of 10-90 keV and beam fluxes of 10(13)-10(16) ions/cm2 were implanted on vertically-aligned ZnO nanorods. Energy dispersive X-ray spectroscopy measurements showed that N+ ions were spread uniformly over the nanorods. Extended X-ray absorption fine structure measurements revealed that the implanted N+s had partially substituted for the oxygen sites. Photoluminescence measurements showed a neutral-donor bound exciton peak at 3.36 eV and a two-electron-satellite peak at 3.33 eV independent of the ion energy and flux. The I-V characteristic curves showed that the current density was not changed by the N+ ion energy and flux much. These results strongly suggested that the N ions substituted for the oxygen sites were neutral.

7.
Appl Opt ; 40(22): 3635-9, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18360392

RESUMO

Real-time diffraction efficiency is measured during hologram formation in undeveloped dichromated gelatin (DCG) film. The main features of real-time diffraction efficiency of undeveloped DCG reveal double peaks with increasing exposure time. Adopting the grating translation technique, we show that the first peak originates from the absorption grating and that the latter is related to the phase grating. To explain such complicated hologram-formation dynamics, we present a phenomenological model for mixed gratings associated with photoinduced refractive-index changes and absorption changes. We have compared the model results with the experimental results, which show good agreement.

8.
Arch Neurol ; 57(8): 1190-3, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10927800

RESUMO

OBJECTIVE: To evaluate the safety and efficacy of botulinum toxin A (BTX) injections in the treatment of tics in patients with Tourette syndrome (TS). BACKGROUND: BTX is an effective treatment for an increasing number of conditions characterized by abnormal muscle contractions. BTX may improve not only the motor component of tics, but also premonitory sensations that precede tics. METHODS: Thirty-five patients (30 male, 5 female) were treated with BTX in the sites of their most problematic tics. Response to BTX was based on a 0 to 4 clinical rating scale (0, no improvement, to 4, marked improvement in both severity and function). Questionnaires were administered to evaluate patients' impressions of overall efficacy and degree of benefit with premonitory sensations. RESULTS: Mean duration of tics prior to initial injection was 15.3 years (range, 1-62 years) and mean duration of follow-up was 21.2 months (range, 1. 5-84 months). The mean peak effect response in 35 patients treated in 115 sessions was 2.8 (range, 0-4); the mean duration of benefit was 14.4 weeks (maximum, 45 weeks); and the mean latency to onset of benefit was 3.8 days (maximum, 10 days). Twenty-one (84%) of 25 patients with premonitory sensations derived marked relief of these symptoms (mean benefit, 70.6%). Total mean dose was 502.1 U (range, 15-3550 U); mean number of visits, 3.3 (range, 1-16); and mean dose per visit, 119.9 U (range, 15-273 U). Sites of injections were as follows: cervical or upper thoracic area (17), upper face (14), lower face (7), vocal cords (4), upper back and/or shoulder (3), scalp (1), forearm (1), leg (1) and rectus abdominis (1). Complications included neck weakness (4), dysphagia (2), ptosis (2), nausea (1), hypophonia (1), fatigue (1), and generalized weakness (1), which were all mild and transient. CONCLUSIONS: Botulinum toxin A injections are an effective and well-tolerated treatment of tics. In addition to improving the motor component of tics, BTX also provides relief of premonitory sensations. Arch Neurol. 2000;57:1190-1193


Assuntos
Antidiscinéticos/administração & dosagem , Toxinas Botulínicas/administração & dosagem , Tiques/tratamento farmacológico , Síndrome de Tourette/tratamento farmacológico , Adolescente , Adulto , Idoso , Criança , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Resultado do Tratamento
9.
Opt Lett ; 20(20): 2131-3, 1995 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19862274

RESUMO

We have developed a combined binary-phase hologram (CBPH) consisting of two binary-phase holograms. The CBPH can be used effectively for optical interconnection and image processing because it suppresses the unwanted images of a conventional binary-phase hologram. The theory and properties of the CBPH and experimental results are presented.

10.
Appl Opt ; 34(26): 6008-11, 1995 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-21060438

RESUMO

We present a method for binary phase spatial modulation that uses photoinduced anisotropy in a chalcogenide amorphous As(2)S(3) thin film and its application to binary phase-only filters in a VanderLugt optical correlator. The time-dependent light-transmission properties of the photoilluminated As(2)S(3) thin film are analytically examined by use of third-order nonlinear polarization theory. Experimental results on optical correlation are discussed.

11.
Opt Lett ; 19(17): 1299-301, 1994 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-19855500

RESUMO

It is demonstrated that the emergence of subharmonics during two-wave mixing in a Bi(12)SiO(20) photorefractive crystal under applied alternating electric fields will markedly reduce two-wave gain. The repetition frequency at which the observed drop in two-wave gain appears is correlated with threshold conditions for the subharmonic instability for a wide range of experimental parameters.

12.
Appl Opt ; 33(15): 3189-91, 1994 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-20885686

RESUMO

We present an all-optical polarization switching of an asymmetric Fabry-Perot étalon containing a nonlinear Kerr medium in reflection type. Reflectance of a signal wave breaks up into two orthogonal polarization components as a result of photoinduced birefringent effects and shows distinct features of intensity stability and a high extinction ratio in polarization switching-modulation and memory operations.

13.
Appl Opt ; 28(4): 737-9, 1989 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-20548552

RESUMO

We report on nonlinear optical image processing, such as image addition and subtraction, using photoinduced anisotropy in amorphous As(2)S(3) thin film and propose a method for contrast reversal and edge enhancement of an image.

14.
Opt Lett ; 13(6): 437-9, 1988 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-19745924

RESUMO

Theoretical explanations of the kinetics of scalar and vector holographic gratings are developed, and experimental results are obtained in amorphous AS(2)S(3) thin films. The large nonlinear-optical susceptibilities are evaluated from experimental data in the vicinity of the fundamental absorption edge, and it is found that chi((3))(1111) congruent with 3.2 x 10(-2) esu and chi((3))(1122)/chi((3))(1111) congruent with 0.98.

15.
Appl Opt ; 27(14): 2858-62, 1988 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20531853

RESUMO

Photoinduced changes in the optical properties of amorphous chalcogenide As(2)S(3) thin films are explained by using the density matrix formalism. The treatment based on the double well potential model for a four-level system gives an improved analytic expression for nonlinear optical absorption coefficients and explicitly shows the break of reciprocity law between illumination intensity and exposure. Photodarkening and photobleaching kinetics obtained theoretically are compared with experimental results obtained in the present work.

16.
Opt Lett ; 10(11): 568-70, 1985 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-19730487

RESUMO

A phase-conjugate wave is generated by degenerate four-wave mixing in an amorphous chalcogenide As(2)S(3) thin film. The time-dependent behaviors of the phase-conjugate wave, the nonlinear absorption coefficient, and the refractive index are treated analytically, and the results are compared with those of experiment. The analyses are based on the rate equations obtained from a simplified energy-band model of amorphous As(2)S(3).

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...