Inhibitory effect of emodin and Astragalus polysaccharide on the replication of HBV.

Aim: To evaluate the anti-viral effect of emodin plus Astragalus polysaccharide (APS) in hepatitis B virus (HBV) transgenic mice.

Methods: Sixty HBV transgenic mice (HBV TGM) whose weight varied between 18 and 24 g were randomly divided into 3 groups, with 20 mice in each group. Group A was the normal control, where the mice were treated with physiological saline; group B was the positive control where the mice were treated with lamivudine solution (100 mL/kg per day).

Generation of extended filaments of femtosecond pulses in air by use of a single-step phase plate.

We experimentally demonstrate that by use of a phase plate that is placed between an adjustable aperture and a focusing lens, the length of the filament can be dramatically extended in air with a femtosecond laser pulse. In addition, the far-field beam profile captured after the filament indicates that the supercontinuum is strongly confined on axis, and a single filament appears to be attainable at relatively high input pulse power when the phase plate is used.

[Angiogenesis inhibitory effect of saikosaponin-d on chicken embryo].

Objective: To investigate the inhibitory effects of saikosaponin-d (SSd) on angiogenesis in chicken embryos and its mechanism of action.

Methods: Chorioallantoic membrane (CAM) model was established successfully in 86 chicken embryos. They were divided into 4 groups after fenestration: the three SSd treated groups (A, B and C) treated with high (20 microg/mL, n = 16), middle (10 microg/mL, n = 19) and low (5 microg/mL, n = 25) dose of SSd respectively, and the control group treated with 0.

Large area uniform nanostructures fabricated by direct femtosecond laser ablation.

An approach for fabricating large area uniform nanostructures by direct femtosecond (fs) laser ablation is presented. By the simple scanning technique with appropriate irradiation conditions, arbitrary size of uniform, complanate nano-grating, nano-particle, and nano-square structures can be produced on wide bandgap materials as well as graphite. The feature sizes of the formed nanostructures, which can be tuned in a wide range by varying the irradiation wavelength, is about 200 nm with 800 nm fs laser irradiation.

Far-field superresolution imaging with dual-dye-doped nanoparticles.

We propose to achieve superresolution in far-field fluorescence imaging by use of silica nanoparticles codoped with Cy3 and Cy5 molecules at a controllable ratio. Owing to the short distances between the dye molecules confined in the nanoparticles, Förster resonant energy transfer can efficiently occur between the Cy3 and Cy5 molecules. Therefore, the Cy5 molecules can quench the fluorescence emission from the Cy3 molecules in the outer region of focal spot of the excitation beam when the excitation intensity is properly chosen, thereby enhancing the resolution of imaging.

Generation of a coherent x ray in the water window region at 1 kHz repetition rate using a mid-infrared pump source.

We demonstrate the generation of a coherent x ray in the water window region in a gas cell filled with neon gas using a wavelength-tunable mid-IR femtosecond laser operating at 1 kHz repetition rate. The cutoff energy and conversion efficiency of the water window x ray can be optimized by tuning gas pressure as well as the focal position.

Charge and spin orderings in triangular t-J-V model with quarter filling: application to Na(0.5)CoO(2).

We investigated the ground state (GS) properties of the single-orbital t-J-V model in a quarter-filling two-dimensional triangular lattice with the slave-boson mean-field approach. We found that the charge ordering (CO) and spin ordering arising from the spin exchange interaction J competes with that from the inter-site Coulomb interaction V. For comparatively large J, the stable GS is insulating with striped CO and antiferromagnetic ordering, avoiding the homogeneous frustrated phase.

Investigation of the influence of the aberration induced by a plane interface on STED microscopy.

The structure of the inhibition patterns is important to the stimulated emission depletion (STED) microscopy. Usually, Laguerre- Gaussian (LG) beam and the central zero-intensity patterns created by inserting phase masks in Gaussian beams are used as the erase beam in STED microscopy. Aberration is generated when focusing beams through an interface between the media of the mismatched refractive indices.

Brachial-ankle pulse wave velocity as an early indicator of left ventricular diastolic function among hypertensive subjects.

While increased arterial stiffness is a known risk of cardiovascular disease, pulse wave velocity (PWV) is a conventionally adopted index of arterial stiffness. However, the relationship between PWV and left ventricular functions are not thoroughly evaluated. This cross-sectional study investigated whether PWV measurement is an early indicator of left ventricular (LV) dysfunction.

Electro-optic integration of embedded electrodes and waveguides in LiNbO3 using a femtosecond laser.

We describe the fabrication of a Mach-Zehnder optical modulator in LiNbO(3) by femtosecond laser micromachining, which is composed of optical waveguides inscripted by a femtosecond laser and embedded microelectrodes subsequently fabricated using femtosecond laser ablation and selective electroless plating. A half-wave voltage close to 19 V is achieved at a wavelength of 632.8 nm with an interaction length of 2.

Protective effects of emodin and astragalus polysaccharides on chronic hepatic injury in rats.

Background: Chinese medicine plays an important role in hepatoprotective treatment. This study was conducted to investigate the protective effects of emodin and astragalus polysaccharides (APS) in a rat model of chronic hepatic injury.

Methods: Chronic hepatic injury was induced by hypodermic injection of an olive oil solution containing 40% carbon tetrachloride (CCl(4)) twice a week, in addition to a diet of 79.

Optimization of multi-cycle two-color laser fields for the generation of an isolated attosecond pulse.

The effect of the mixing of pulsed two color fields on the generation of an isolated attosecond pulse has been systematically investigated. One main color is 800 nm and the other color (or secondary color) is varied from 1.2 to 2.

Three-photon-excited upconversion luminescence of niobium ions doped silicate glass by a femtosecond laser irradiation.

We report on the bluish green upconversion luminescence of niobium ions doped silicate glass by a femtosecond laser irradiation. The dependence of the fluorescence intensity on the pump power density of laser indicates that the conversion of infrared irradiation to visible emission is dominated by three-photon excitation process. We suggest that the charge transfer from O(2-) to Nb(5+) can efficiently contribute to the bluish green emission.

Theoretical investigation of single attosecond pulse generation in an orthogonally polarized two-color laser field.

We theoretically demonstrate the generation of extreme ultraviolet supercontinua in an orthogonally polarized two-color few-cycle laser field. We show that the ionized electrons can be driven back to their parent ion after traveling along curved trajectories in a plane perpendicular to the beam propagation direction, giving rise to a train of attosecond pulses at different polarization angles. A single isolated attosecond pulse can be obtained by blocking the low-order high harmonics, which contribute to the formation of the satellite pulses.

Enhancement and broadening of extreme-ultraviolet supercontinuum in a relative phase controlled two-color laser field.

We experimentally demonstrate the generation of an extreme-ultraviolet (XUV) supercontinuum in argon with a two-color laser field consisting of an intense 7 fs pulse at 800 nm and a relatively weak 37 fs pulse at 400 nm. By controlling the relative time delay between the two laser pulses, we observe enhanced high-order harmonic generation as well as spectral broadening of the supercontinuum. A method to produce isolated attosecond pulses with variable width and intensity is proposed.

Carrier-envelope phase dependence of few-cycle ultrashort laser pulse propagation in a polar molecule medium.

We theoretically investigate carrier-envelope phase dependence of few-cycle ultrashort laser pulse propagation in a polar molecule medium. Our results show that a soliton pulse can be generated during the two-photon resonant propagation of few-cycle pulse in the polar molecule medium. Moreover, the main features of the soliton pulse, such as pulse duration and intensity, depend crucially on the carrier-envelope phase of the incident pulse, which could be utilized to determine the carrier-envelope phase of a few-cycle ultrashort laser pulse from a mode-locked oscillator.

Selective metallization on insulator surfaces with femtosecond laser pulses.

We report selective metallization on surfaces of insulators (glass slides and lithium niobate crystal) based on femtosecond laser modification combined with electroless plating. The process is mainly composed of four steps: (1) formation of silver nitrate thin films on the surfaces of glass or crystal substrates; (2) generation of silver particles in the irradiated area by femtosecond laser direct writing; (3) removal of unirradiated silver nitrate films; and (4) selective electroless plating in the modified area. We discuss the mechanism of selective metallization on the insulators.

Generation of an extreme ultraviolet supercontinuum in a two-color laser field.

We theoretically investigate the high-order harmonic generation in a helium atom with a two-color optical field synthesized by an intense 6 fs pulse at 800 nm and a relatively weak 21.3 fs pulse at 400 nm. When the frequency-doubled pulse is properly time shifted with respect to the fundamental pulse, an ultrabroad extreme ultraviolet supercontinuum spectrum with a 148 eV spectral width can be generated which directly creates an isolated 65 as pulse even without phase compensation.

Fabrication of microfluidic optical waveguides on glass chips with femtosecond laser pulses.

We describe the fabrication of microfluidic channel structures on the surface of a borosilicate glass slide by femtosecond laser direct writing for optical waveguide application. Liquid with a variable refractive index is fed into the microchannel, serving as the core of the waveguide. We demonstrate that either a multimode or a single-mode waveguide can be achieved by controlling the refractive index of the liquid.

A predictive study on the role and function of the dental hygienist in Taiwan.

Objectives: The purpose of this study was to achieve a consensus on the work roles and scope of practice of dental hygienists in Taiwan and to rank the results according to their importance.

Methods: A modified Delphi technique was used to enquire how experts view their role and function as a dental hygienist in Taiwan. Three groups of 105 experts (dentists, officials and scholars) were surveyed.

Microstructural changes of enamel, dentin-enamel junction, and dentin induced by irradiating outer enamel surfaces with CO2 laser.

The microstructural changes of enamel, dentin-enamel junction (DEJ), and dentin after CO(2) laser irradiation were studied. Buccal enamel surfaces of human third molars about 2 mm from the DEJ were irradiated, and the laser tip was moved 5 mm in a mesiodistal direction with 5 s of irradiation time. The output powers were 2 to 10 W in a continuous mode, and the average doses were approximately from 250 to 1,250 J/cm(2).

Inhibitory effects of saikosaponin-d on CCl4-induced hepatic fibrogenesis in rats.

Aim: To investigate the suppressive effect of saikosaponin-d (SSd) on hepatic fibrosis in rats induced by CCl(4) injections in combination with alcohol and high fat, low protein feeding and its relationship with the expression of nuclear factor-kappaB (NF-kappaB), tumor necrosis factor-alpha (TNF-alpha) and interleukins-6 (IL-6).

Methods: Hepatic fibrosis models were induced by subcutaneous injection of CCl(4) at a dosage of 3 mL/kg in rats. At the same time, rats in treatment groups were injected intraperitoneally with SSd at different doses (1.

Freestanding optical fibers fabricated in a glass chip by femtosecond laser micromachining for lab-on-a-chip application: erratum.

An erratum is presented to correct the propagation loss of the freestanding optical fibers fabricated in glass chip.

Femtosecond laser microprocessing with three-dimensionally isotropic spatial resolution using crossed-beam irradiation.

We describe the use of a crossed-beam irradiation system in three-dimensional femtosecond laser microprocessing to obtain three-dimensionally isotropic spatial resolution. In the crossed-beam geometry, two orthogonal objective lenses are arranged to share a common focal point. The synthesized focal spot produces an isotropic illumination volume.

Freestanding optical fibers fabricated in a glass chip using femtosecond laser micromachining for lab-on-a-chip application.

We describe the fabrication of freestanding optical fibers in a glass chip by femtosecond laser three-dimensional (3D) micro-machining. The process has mainly four steps: (1) femtosecond laser scanning of the areas surrounding the fibers; (2) postan-nealing of the sample for the modification of the exposed areas; (3) chemical etching of the sample for the selective removal of the modified areas; and (4) second postannealing for smoothening the surfaces of the fibers. The measured optical loss of the fibers is approximately 0.