The time-domain characteristics of terahertz radiations emitted from a biased largeaperture photoconductive antenna trigged by an ultra-short optical pulse are studied. Succinct explicit expressions in the surface field and in the far field for the emitted THz radiation fields are deduced based on the well-known current-surge model. The expressions indicate that the THz radiations in the surfac...

BACKGROUND Serum fibroblast growth factor-23 (FGF-23) is associated with cardiovascular disease (CVD), yet the mechanisms remain uncertain. Our objective was to determine whether higher FGF-23 concentrations are associated with arterial stiffness. METHODS In this cross-sectional study, serum FGF-23 concentrations were measured in 5977 participants without known CVD in the Multi-Ethnic Study o...

nephritis remains an important problem in patients with systemic lupus erythematosus (sle). we conducted retrospective study to evaluate the efficiency of intravenous pulse cyclophosphamide in lupus nephritis: from 1983 to 1993, we reviewed 133 patients with biopsy proven lupus nephritis, 47 of them excluded because of short period of follow-up or defective laboratory data. eighty six patients ...

this research was carried out in order to evaluate the influence of different concentrations of ethanol and methanol (0, 4, 6 and 12%) and two pulse treatments (12 and 24 hour) on longevity of cut standard-carnation (sensi cultivar) in a factorial based on randomized completely design with three replications, at tehran university, aboreyhan pardis, horticulture department, during 2010. the resu...

The predicted spectral phase of a fiber continuum pulsed source rigorously quantified by the scalar generalized nonlinear Schrödinger equation is found to be in excellent agreement with that measured by multiphoton intra-pulse interference phase scan (MIIPS) with background subtraction. This cross-validation confirms the absolute pulse measurement by MIIPS and the transform-limited compression ...

Shorter pulse durations help confine thermal damage during retinal photocoagulation, decrease treatment time and minimize pain. However, safe therapeutic window (the ratio of threshold powers for rupture and mild coagulation) decreases with shorter exposures. A ring-shaped beam enables safer photocoagulation than conventional beams by reducing the maximum temperature in the center of the spot. ...

In order to expand the application range of laser welding and improve weld quality, an extra pulse current was used to aid laser-welded 2219 aluminum alloy, and the effects of pulse current parameters on the weld microstructure and mechanical properties were investigated. The effect mechanisms of the pulse current interactions with the weld pool were evaluated. The results indicated that the co...

A learning algorithm was used to manipulate optical pulse shapes and optimize retinal isomerization in bacteriorhodopsin, for excitation levels up to 1.8 x 10(16) photons per square centimeter. Below 1/3 the maximum excitation level, the yield was not sensitive to pulse shape. Above this level the learning algorithm found that a Fourier-transform-limited (TL) pulse maximized the 13-cis populati...