Large-mode-area Nd-doped anti-resonant phosphate fiber for high-power single-mode 900 nm laser generation.

In this work, we propose an Nd-doped double-layer anti-resonant phosphate fiber with a core diameter of 50 µm for high-power single-mode 900 nm laser generation. Double-layer interlaced anti-resonant elements were designed here to enhance the fundamental mode confinement capability of the large-mode-area Nd-doped fiber core. Moreover, a double-layer F-P etalon formed between the anti-resonant elements and the inner cladding was analyzed for the first time for fiber loss manipulation.

Biomechanics evaluation of sacroiliac joint pain after lumbosacral fusion: A finite element analysis.

The sacroiliac joint (SIJ) constitutes the predominant pain source following lumbar or lumbosacral fusion. Although studies have investigated the biomechanical patterns of SIJ behaviors after lumbosacral fusion, the relationship between ligament strain and SIJ pain following lumbosacral fusion remains unclear. The present study developed a three-dimensional finite element model including L4, L5, sacrum, ilium, SIJ, and seven mainly ligaments.

Integrated biomarker responses of the submerged macrophyte via hydrological processes from Lake Poyang, China.

, a widely distributed wetland plant, was used to reveal how the light intensity at the top of the plant, plant morphology and antioxidant enzyme activity respond to different hydrologic conditions from Lake Poyang, China. By designing a laboratory experiment simulating historical water levels of low, normal and high wetland plant submersion, this study aimed to elucidate the effects of different levels of flooding on growth and antioxidant enzyme activity for . The results showed that the plant crown light intensity of the treated group and control group (CG) first decreased and then increased along with the seasonal variation of the water level.

In vitro and in vivo characterization of a novel H1N1/2009 influenza virus reassortant with an NS gene from a highly pathogenic H5N1 virus, isolated from a human.

The triple-reassortant H1N1/2009 influenza A virus, which caused the first influenza pandemic of the 21 century, is generally associated with mild disease and a relatively low mortality rate comparable to that of seasonal influenza virus outbreaks. There is a growing concern about the potential for reassortment between the low-mortality H1N1/2009 and other high-mortality influenza viruses. Here, we describe and characterize a novel reassortant H1N1/2009 influenza virus, isolated from a human sample, that contained an NS gene from a highly pathogenic H5N1 virus.

Quantitative investigation of ligament strains during physical tests for sacroiliac joint pain using finite element analysis.

It may be assumed that the stability is affected when some ligaments are injured or loosened, and this joint instability causes sacroiliac joint pain. Several physical examinations have been used to diagnose sacroiliac pain and to isolate the source of the pain. However, more quantitative and objective information may be necessary to identify unstable or injured ligaments during these tests due to the lack of understanding of the quantitative relationship between the physical tests and the biomechanical parameters that may be related to pains in the sacroiliac joint and the surrounding ligaments.

MDCK cell-cultured influenza virus vaccine protects mice from lethal challenge with different influenza viruses.

Influenza epidemics are major health concern worldwide. Vaccination is the major strategy to protect the general population from a pandemic. Currently, most influenza vaccines are manufactured using chicken embroynated eggs, but this manufacturing method has potential limitations, and cell-based vaccines offer a number of advantages over the traditional method.

Identification of B- and T-cell epitopes from glycoprotein B of herpes simplex virus 2 and evaluation of their immunogenicity and protection efficacy.

Herpes simplex virus (HSV) infection is a major health concern worldwide. Evidence obtained from animals and humans indicates that B- and T-cell responses contribute to protective immunity against herpes virus infection. Glycoprotein B is a transmembrane envelope component of HSV-1 and HSV-2, which plays an important role in virion morphogenesis and penetration into host cells, and can induce neutralizing antibodies and protective T-cell response when it is used to immunize humans and animals.

220 μJ monolithic single-frequency Q-switched fiber laser at 2 μm by using highly Tm-doped germanate fibers.

We report a unique all fiber-based single-frequency Q-switched laser in a monolithic master oscillator power amplifier configuration at ~1920 nm by using highly Tm-doped germanate fibers for the first time. The actively Q-switched fiber laser seed was achieved by using a piezo to press the fiber in the fiber Bragg grating cavity and modulate the fiber birefringence, enabling Q-switching with pulse width and repetition rate tunability. A single-mode polarization maintaining large core 25 μm highly Tm-doped germanate fiber was used in the power amplifier stage.

Kilowatt-level stimulated-Brillouin-scattering-threshold monolithic transform-limited 100 ns pulsed fiber laser at 1530 nm.

We demonstrate a high-stimulated-Brillouin-scattering-threshold monolithic pulsed fiber laser in a master oscillator power amplifier configuration that can operate over the C band. In the power amplifier stage, we used a newly developed single-mode, polarization maintaining, and highly Er/Yb codoped phosphate fiber with a core diameter of 25 microm. A single-frequency actively Q-switched fiber laser was used to generate pulses in the hundreds of nanoseconds at 1530 nm.

Enhanced terahertz source based on external cavity difference-frequency generation using monolithic single-frequency pulsed fiber lasers.

We demonstrate a resonant external cavity approach to enhance narrowband terahertz radiation through difference-frequency generation for the first time (to our knowledge). Two nanosecond laser pulses resonant in an optical cavity interact with a nonlinear crystal to produce a factor of 7 enhancement of terahertz power compared to a single-pass orientation. This external enhancement approach shows promise to significantly increase both terahertz power and conversion efficiency through optical pump pulse enhancement and effective recycling.

High SBS-threshold single-mode single-frequency monolithic pulsed fiber laser in the C-band.

We report a high SBS-threshold, single-frequency, single-mode, polarization maintaining (PM) monolithic pulsed fiber laser source in master oscillator and power amplifier (MOPA) configuration that can operate over the C-band. In order to achieve a narrow transform-limited linewidth for pulses longer than 100 ns, we use a single-frequency Q-switched fiber laser seed, which itself can be seamlessly tuned up to 1.24 micros.

Highly efficient high-power thulium-doped germanate glass fiber laser.

A 64 W fiber laser at 1.9 microm with a slope efficiency of 68% with respect to the launching pump power at 800 nm was demonstrated in a one-end pump configuration using a piece of 20 cm long newly developed thulium-doped germanate glass double-cladding single-mode fiber. A quantum efficiency of 1.