Ultra-broadband wavelength-swept Ti:sapphire crystal fiber laser.

An ultra-broadband wavelength-swept laser (WSL) was generated using glass-clad Ti:sapphire crystal fiber as the gain media. Due to the low signal propagation loss of the crystal fiber, the swept laser has a tuning bandwidth of 250 nm (i.e., 683 nm to 933 nm) at a repetition rate of 1200 Hz. The steady-state and pulsed dynamics of the WSL were analyzed. The 0.018-nm instantaneous linewidth corresponds to a 3-dB coherence roll-off of 7 mm. When using the laser for swept-source optical coherence tomography, an estimated axial resolution of 1.8 µm can be achieved.

Detection of white spot syndrome virus by polymerase chain reaction performed under insulated isothermal conditions.

Aiming to develop a rapid, low-cost, and user-friendly system for the diagnosis of white spot syndrome virus (WSSV), a PCR assay performed in capillary tubes under insulated isothermal conditions (iiPCR assay) was established on the basis of Rayleigh-Benard convection. WSSV amplicons were generated reproducibly within 30 min from a target sequence-containing plasmid in an iiPCR device, in which a special polycarbonate capillary tube (R-tube™) was heated isothermally by a copper ring attached to its bottom and shielded by a thermal baffle around its upper half. Furthermore, WSSV-specific amplicons were produced from nucleic acid extracts of WSSV-infected Penaeus vannamei in the WSSV iiPCR assay, with sensitivity comparable to that of an OIE-certified commercial nested PCR kit (IQ2000™ WSSV Detection and Prevention System). Specificity of the WSSV iiPCR assay was demonstrated as no amplicons were generated from shrimp genomic DNA, and IHHNV, MBV, and HPV DNA. iiPCR has a potential as a low-cost method for sensitive, specific and rapid detection of pathogens.

Nonlinear dependence between the surface reflectance and the duty-cycle of semiconductor nanorod array.

The nonlinear dependence between the duty-cycle of semiconductor nanorod array and its surface reflectance minimization is demonstrated. The duty-cycle control on thin-SiO2 covered Si nanorod array is performed by O(2-) plasma pre-etching the self-assembled polystyrene nanosphere array mask with area density of 4 × 10(8) rod/cm(-2). The 120-nm high SiO2 covered Si nanorod array is obtained after subsequent CF4/O2 plasma etching for 160 sec. This results in a tunable nanorod diameter from 445 to 285 nm after etching from 30 to 80 sec, corresponding to a varying nanorod duty-cycle from 89% to 57%. The TM-mode reflection analysis shows a diminishing Brewster angle shifted from 71° to 54° with increasing nanorod duty-cycle from 57% to 89% at 532 nm. The greatly reduced small-angle reflectance reveals a nonlinear trend with enlarging duty-cycle, leading to a minimum surface reflectance at nanorod duty-cycle of 85%. Both the simulation and experiment indicate that such a surface reflectance minimum is even lower than that of a uniformly SiO2 covered Si substrate on account of its periodical nanorod array architecture with tuned duty-cycle.

Effects of home-based constraint-induced therapy versus dose-matched control intervention on functional outcomes and caregiver well-being in children with cerebral palsy.

This study compared home-based constraint-induced therapy (CIT) with a dose-matched home-based control intervention for children with cerebral palsy (CP). The differences in unilateral and bilateral motor performance, daily functions, and quality of parental well-being (i.e., the stress level of their parents) were evaluated. The study included 21 children with CP (age range, 48-119 months) who were randomly assigned to the CIT or control group. All participants received individualized home-based interventions, 3.5-4h a day, twice a week for 4weeks. Primary outcomes were measured by the Peabody Developmental Motor Scales II (PDMS-2) and the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) is the whole name of the assessment. All first letters of this instrument title should be in upper case. Secondary outcome measures were the Pediatric Motor Activity Log (PMAL), the Caregiver Functional Use Survey (CFUS), and the Parenting Stress Index-Short Form (PSI). Outcome measures were performed at baseline (pretreatment), 4weeks (posttreatment), and 6-month (follow-up). Compared with the control group, the CIT group exhibited significantly better performance in grasping control as measured by the PDMS-2, unilateral/bilateral motor efficacy as measured by the BOTMP, and unilateral hand function as measured by the PMAL immediately after the treatment. At the 6-month follow-up, CIT had beneficial effects on grasping control assessed by PDMS-2 and on unilateral/bilateral functional performance measured by the PMAL and CFUS. Parents in both groups reported comparable stress levels at the 6-month follow-up, although the parent-child dysfunctional interaction deteriorated more immediately after CIT than after the control intervention. The follow-up of this randomized controlled trial suggested beneficial effects of home-based CIT on unilateral grasping skills and unilateral/bilateral functional performance at 6 months. The higher stress level reported by the parents in the CIT group than in the control group at posttreatment is temporary and could be alleviated at a longer period of time. Home-based CIT is a feasible and effective alternative to the intervention administered at clinics.

Real-time target-specific detection of loop-mediated isothermal amplification for white spot syndrome virus using fluorescence energy transfer-based probes.

Aiming to establish a target amplicon-specific detection system for loop-mediated isothermal amplification (LAMP), the fluorescent resonance energy transfer (FRET) probe technology was applied to develop the FRET LAMP platform. This report describes the development of the first FRET LAMP assay targeting white spot syndrome virus (WSSV) of penaeid shrimp. A successful accelerated WSSV LAMP was assembled first in a conventional oven and confirmed by gel electrophoresis and dot-blot hybridization. Subsequently, two additional FRET probes designed to target one loop region within WSSV LAMP amplicons were added to the same LAMP reaction. The reactions were carried out in a LightCycler (Roche) and significant FRET signals were detected in real time. Optimization of the reaction using plasmid DNA shortened the time for the detection of 10(2) copies of the target DNA to less than 70min. Cross reactivity was absent with WSSV-free or infectious hypodermal and hematopoietic necrosis virus-infected Penaeus vannamei samples. The performance of this system was comparable with that of a nested PCR assay from 21 WSSV-infected shrimp. Specifically detecting target amplicons and requiring no post-amplification manipulation, the novel FRET LAMP assay should allow indisputable detection of pathogens with minimized risks of amplicon contamination.

50 fs soliton compression of optical clock pulse recovered from NRZ data injected SOAFL.

Mode-locking of semiconductor optical amplifier fiber laser (SOAFL) with 50 fs pulses by extracting the clock of an optical non-return-to-zero (NRZ) data injection is demonstrated. The efficiency of mode-locking in the SOAFL is improved by increasing the seeding power of the large-duty-cycle NRZ data from 3 to 8 dBm into the SOA driven at biased current of 350 mA. After linear dispersion compensation, the mode-locked SOAFL pulsewidth can be further shortened from 20 to 3 ps by increasing the DCF length up to 110 m. By using a booster the EDFA to enlarge the average power of mode-locked SOAFL pulse to 1.3 W, the shortest soliton pulse is occurred after propagating through a 12-m-long SMF. The amplified SOAFL pulse can be compressed to 50 fs after nonlinear compression with its spectral linewidth broadening to 64 nm. Nearly transform-limited time-bandwidth product of 0.436 and the maximum pulse compressing ratio of 400 are reported to date.

Compression of 200 GHz DWDM channelized TDM pulsed carrier from optically modelocking WRC-FPLD fiber ring at 10 GHz.

The compression of 200GHz DWDM channelized optically mode-locking WRC-FPLD fiber ring pulse of at 10 GHz is performed for high-capacity TDM application. To prevent temporal and spectral cross-talk, the duty-cycle of the DWDM channelized WRC-FPLD FL pulse needs to be shortened without broadening its linewidth. With dual-cavity configuration induced DWDM channelization, a shortest single-channel WRC-FPLD FL pulsewidth of 19 ps is generated, which can be linearly compensated to 10 ps and fifth-order soliton compressed to 1.4 ps. Under a maximum pulsewidth compression ratio up to 14 and a +/-100 m tolerance on compressing fiber length, the single-channel pulsewidth remains <2 ps (duty-cycle <2%) with spectral linewidth only broadening from 0.29 nm to 0.8 nm. In comparison, a typical SOAFL without intra-cavity TBF in fiber ring broadens its spectral linewidth from 2.4 to 3.8 nm after compressing its mode-locked pulsewidth from 21 to 2.1 ps. The duty-cycle of the DWDM channelized WRC-FPLD FL pulsed carrier is approaching 1% to satisfy at least 256 optical TDM channels.

Peak equalization of rational-harmonic-mode-locking fiberized semiconductor laser pulse via optical injection induced gain modulation.

Optical injection induced gain modulation of a semiconductor optical amplifier (SOA) is demonstrated to equalize the peak intensity of pulses generating from the rational-harmonic-mode-locking (RHML) SOA based fiberized semiconductor laser. This is achieved by adjusting the temporal shape of the injected optical signal generated from a Mach-Zehnder intensity modulator, in which the DC biased level exceeding Vpi and the electrical pulse amplitude of 1.5Vpi are concurrently employed. Numerical simulation on the injected optical signal profile and the SOA gain during the inverse-optical-pulse injection induced gain modulation process are also demonstrated. After a peculiar inverse-optical-pulse injection, each pulse in the 5th-order RHML pulse-train experiences different gain from temporally varied SOA gain profile, leading the pulse peak to equalize one another with a minimum standard deviation of 2.5% on the peak intensity variation. The optimized 5th-order RHML pulse exhibits a signal-to-noise suppression ratio of 20 dB and a reduced variation on temporal spacing from 11 to 4 ps. The clock amplitude jitter is compress from 35.3% to 7.3%, which is less than the limitation up to 10% for 5th order RHML generation.