Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Biomed Opt ; 26(1)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33386708

RESUMO

SIGNIFICANCE: Line scanning-based temporal focusing multiphoton microscopy (TFMPM) has superior axial excitation confinement (AEC) compared to conventional widefield TFMPM, but the frame rate is limited due to the limitation of the single line-to-line scanning mechanism. The development of the multiline scanning-based TFMPM requires only eight multiline patterns for full-field uniform multiphoton excitation and it still maintains superior AEC. AIM: The optimized parallel multiline scanning TFMPM is developed, and the performance is verified with theoretical simulation. The system provides a sharp AEC equivalent to the line scanning-based TFMPM, but fewer scans are required. APPROACH: A digital micromirror device is integrated in the TFMPM system and generates the multiline pattern for excitation. Based on the result of single-line pattern with sharp AEC, we can further model the multiline pattern to find the best structure that has the highest duty cycle together with the best AEC performance. RESULTS: The AEC is experimentally improved to 1.7 µm from the 3.5 µm of conventional TFMPM. The adopted multiline pattern is akin to a pulse-width-modulation pattern with a spatial period of four times the diffraction-limited line width. In other words, ideally only four π / 2 spatial phase-shift scans are required to form a full two-dimensional image with superior AEC instead of image-size-dependent line-to-line scanning. CONCLUSIONS: We have demonstrated the developed parallel multiline scanning-based TFMPM has the multiline pattern for sharp AEC and the least scans required for full-field uniform excitation. In the experimental results, the temporal focusing-based multiphoton images of disordered biotissue of mouse skin with improved axial resolution due to the near-theoretical limit AEC are shown to clearly reduce background scattering.

2.
Toxicol Mech Methods ; 21(1): 63-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21067310

RESUMO

This study applied broccoli and cauliflower extracts (whole, floret, and stem) to zebrafish larvae in parallel to receive 100 mJ/cm(2) of UVB six times, and recorded their fin malformation phenotypes. Chemopreventive effects of each group, including UVB, whole-, floret-, and stem-extracts of broccoli and cauliflower on fin development were evaluated using Kaplan-Meier analysis, log-rank test, and Cox proportional hazards regression. Results showed that (1) zebrafish fins in the UVB + whole broccoli extract group are 6.20~9.32-times more likely to return to normal fins than ones in the UVB only group, but fins in the UVB + whole cauliflower extract group are only 5.13~11.10-times more likely to recover, indicated that whole broccoli and cauliflower extract had similar chemopreventive ability on fin development; and (2) the broccoli stem has the highest antioxidant capacity among other groups. In conclusion, zebrafish can be used as a system for evaluating the efficacy of other UVB protective compounds.


Assuntos
Nadadeiras de Animais/efeitos da radiação , Brassica/química , Extratos Vegetais/farmacologia , Raios Ultravioleta , Animais , Larva/efeitos dos fármacos , Extratos Vegetais/química , Peixe-Zebra/embriologia
3.
Opt Express ; 17(8): 5987-97, 2009 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-19365417

RESUMO

A surface plasmon-enhanced two-photon total-internal-reflection fluorescence (TIRF) microscope has been developed to provide fluorescent images of living cell membranes. The proposed microscope with the help of surface plasmons (SPs) not only provides brighter fluorescent images based on the mechanism of local electromagnetic field enhancement, but also reduces photobleaching due to having a shorter fluorophore lifetime. In comparison with a one-photon TIRF, the two-photon TIRF can achieve higher signal-to-noise ratio cell membrane imaging due its smaller excitation volume and lower scattering. By combining the SP enhancement and two-photon excitation TIRF, the microscope has demonstrated it's capability for brighter and more contrasted fluorescence membrane images of living monkey kidney COS-7 fibroblasts transfected with an EYFP-MEM or EGFP-WOX1 construct.


Assuntos
Aumento da Imagem/instrumentação , Microscopia de Fluorescência por Excitação Multifotônica/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação , Animais , Células COS , Chlorocebus aethiops , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
4.
Appl Opt ; 44(29): 6155-62, 2005 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-16237928

RESUMO

We develop an angular-interrogation attenuated total reflection (ATR) metrology system for three different plasmonic sensors, namely, a conventional surface plasmon resonance (SPR) device, a coupled-waveguide SPR device, and a nanoparticle-enhanced SPR device. The proposed metrology system is capable of measuring the reflectivity spectra of the transverse magnetic mode and the transverse electric mode simultaneously. Through the optimal control of the fabrication process and use of sophisticated system instrumentation, the experimental results confirm that the developed ATR system is capable of measuring the resonant angle with an angular accuracy of 10(-4) deg.

5.
J Microbiol Immunol Infect ; 36(2): 96-100, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12886959

RESUMO

In this study, 12 Small-Ear-Miniature pigs aged 142 to 185 days were used to determine whether pigs injected with nonviable oncospheres of Taenia solium or Taenia saginata asiatica can become resistant to the challenge of viable eggs of T. solium. The 12 pigs were equally divided into 4 groups: 3 experimental groups in which each pig was injected subcutaneously with a mixture of 0.2 mL complete Freund's adjuvant and 10(4)/0.2 mL nonviable Taiwan/Asian Taenia, Indonesia Taenia, or T. solium oncospheres, and 1 control group in which each pig was injected subcutaneously with 0.2 mL phosphate buffer solution and 0.2 mL complete Freund's adjuvant. Each pig was orally inoculated with 10000 viable T. solium eggs 1 month later. The infection rates were 100% (2/2), 100% (3/3), 33% (1/3), and 100% (3/3) and cysticerci recovery rates were 1.3% (254/20000), 1.2% (371/30000), 0.01% (4/30000), and 8.6% (2,577/30000), respectively. Except for the location of 72 cysticerci located in the viscera, 3134 cysticerci were recovered from the muscles. In the experimental groups, 4 cysticerci recovered were viable and the remaining 625 were either calcified or degenerated. However, 2567 cysticerci recovered from the control group remained viable and only 10 were calcified or degenerated. The results indicate that in addition to the vaccine of T. solium, those of Taiwan Taenia and Indonesia Taenia can also induce high-crossing immunologic reactions against T. solium infection.


Assuntos
Doenças dos Suínos/prevenção & controle , Taenia solium/imunologia , Teníase/veterinária , Vacinação/veterinária , Animais , Congelamento , Humanos , Óvulo/imunologia , Suínos , Taenia saginata , Teníase/prevenção & controle
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA