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In this paper, we report an external-cavity 2128 nm narrow-linewidth optical parametric oscillator involving a reflective volume Bragg grating. Based on the Sellmeier equation, we introduce the thermal expansion coefficient together with the thermally-induced output wavelength shift. When the pump power is 12.91 W, with the repetition rate being 70 kHz, a 2128 nm laser with an output power of 3.85 W is obtained, having the optical-to-optical conversion efficiency equal to 30% and the linewidth equal to 108 nm. Moreover, the output power is 2.71 W at 2128 nm and the output linewidth is compressed to 0.19 nm, when a reflective volume Bragg grating is used instead of a total reflection mirror, with the corresponding optical-to-optical conversion efficiency being 21% and the beam quality factor being M x 2 = 1.92 and M y 2 = 1.98. As a result, a 2128 nm narrow-linewidth laser is implemented. [ABSTRACT FROM AUTHOR]

We demonstrate a pulse-duration tunable Tm3+-doped pulsed all-fiber master oscillator power amplifier (MOPA) operating at a central wavelength of 1908 nm. By using acousto-optic(AO) external modulation, the amplified laser pulse shows a tuning range having pulse durations from 66.5 ns to 8.0 μs and a repetition rate of 100 kHz-2 MHz. The laser achieved a maximum average power of 28.1 W and a corresponding energy of 28.1 μJ at 1MHz with a 3 dB linewidth of 0.63 nm and a beam quality factor of Mx2=1.25 and My2=1.32. The ASE suppression ratio is 50 dB and the corresponding total amplifier gain is 27.5 dB. To the best of our knowledge, it is the highest average output power and slope efficiency (∼51.0%) achieved using AO external modulation in a Tm3+-doped pulsed fiber amplifier. [ABSTRACT FROM AUTHOR]

In this study, ginsenoside Rg3-loaded PEGylated liposomes were prepared and optimized using the Box- Behnken design. These liposomes were characterized, the cumulative release profiles were investigated and compared with ginsenoside Rg3-loaded liposomes in vitro. To improve the stability ginsenoside Rg3-loaded PEGylated liposomes were freeze-dried and the lyoprotectants to be added were screened. The results showed that the liposomes have a small particle size (152.58±0.74 nm) and spherical shape. The encapsulation efficiency and drug-loading rate were approximately 85.24±1.02 and 7.44±0.08 %, respectively. For lyoprotectants, 2 % lactose was chosen as the lyophilized protectant according to the appearance, re-dispersity, particle size, and entrapment efficiency of lyophilization of ginsenoside Rg3- loaded PEGylated liposomes. In vitro release showed that ginsenoside Rg3-loaded PEGylated liposomes showed a more obvious sustained release effect, which suggests that ginsenoside Rg3-loaded PEGylated liposomes might enhance the therapeutic effect of ginsenoside Rg3. [ABSTRACT FROM AUTHOR]

An analytical study on the vibration and energy flow behaviors of a coupled cylindrical shell-plate structure is presented. An analytical model capable of handling general boundary and coupling conditions is developed in which the interactions of all internal forces and moments for both the shell and plate have been taken into account at the junction via four types of coupling springs with arbitrary stiffness and covering all the degrees of freedom, and each of the plate and shell displacement functions is expressed as the superposition of a two-dimensional Fourier series and several supplementary functions. The unknown expansions coefficients are obtained using the Rayleigh-Ritz procedure. The effectiveness and accuracy of the present solution are validated against the FEM results. The energy flow behaviors through this structure are investigated through parametric power flow and structural intensity analysis. The contribution of internal forces or moments to the power flow and the influence of key system parameters on the energy flow are analyzed numerically, including coupling locations, coupling conditions, boundary conditions, and excitation location. The results shed light on the effects of system parameters on the energy flow behaviors of the class of coupled shell-plate structure. [ABSTRACT FROM AUTHOR]

In this paper a two-dimensional (2-D) axisymmetric physical model to express the temperature and thermal stress in damage process of silicon plate irradiated by annular millisecond laser is presented, and analytical solutions of 2-D heat conduction equation and thermo-elastic equations are obtained using integral transform method. Then, the transient temperature fields and the thermal stress of silicon are simulated, and the locations of the maximum temperature rise and the maximum tensile stress are obtained. Finally, the melting damage threshold and the thermal stress damage threshold of silicon are investigated, and the damage threshold changing with irradiating time is discussed. Modelling results show that the damage form of silicon irradiated by annular millisecond laser is melting damage mainly. [ABSTRACT FROM AUTHOR]

A finite element method (FEM) model for simulating long pulsed laser interaction with gallium arsenide (GaAs) at 0.53 µm wavelength for a 1 ms pulse width is established. The distributions of transient temperature fields before melting in different cases have been obtained and the damage characteristics were estimated. Additionally, the decomposition damage thresholds are also given. Numerical results show that heat conduction affects the whole process of long pulsed laser interaction and its damage mechanism is mainly due to thermal effects. The temperature of the centre is highest and rises fastest on the irradiated surface, where it could be damaged first. As the laser energy density increases the occurrence time of the damage gradually advances. [ABSTRACT FROM AUTHOR]

The unsteady characteristics of tip-leakage flow in axial fans with circumferential skewed blades were investigated at off-design conditions using particle image velocimetry (PIV) and wall pressure test. Two circumferential skewed fans, with the blade skew angles at 8.3° forward and backward, respectively, were investigated in this study. The instantaneous flow field in tip clearance region was measured using PIV at peak pressure condition. The static pressure fluctuations near blade tip were captured at off-design conditions using pressure sensors mounted on casing wall. From the measured results, the structure and instantaneous characteristics of tip-leakage flow in circumferential skewed fans were analysed. The tip-leakage vortex instability and its relation with circumferential skewed blades, to expand stall-free operation range of axial fans, were discussed. The forward-skewed blade is found to be effective in controlling tip-leakage flow to expand stall-free operation range at off-design conditions. [ABSTRACT FROM AUTHOR]

Exposure of human skin to ultraviolet radiation (UVR) results in erythema, pigment darkening, skin cancer and photoageing. In addition to conventional organochemical and the physical-mineral type sunscreens (SS), other non-SS protective strategies have been investigated, including antioxidants (AOx) and topical DNA repair enzymes. To investigate whether AOx could improve the protection provided by a broad-spectrum sunscreen (SS) preparation. Volunteers were exposed to repetitive solar-simulated (ss)UVR at 1.5 times minimal erythema dose for four consecutive days. Thirty minutes before each exposure and 6, 24 and 48 h after the last exposure, the test materials [vehicle, SS (sun protection factor 25) alone, AOx alone and SS plus AOx] were applied to four different sites. Another two sites received ssUVR only, or SS plus AOx only, and a third site was left untreated (neither ssUVR or product). Erythema and pigmentation were measured using a Mexameter. Biopsy specimens were taken 72 h after the last irradiation. The thickness of the stratum corneum and epidermis were measured by microscopy. Expression of cytokeratins (CKs), matrix metalloproteinases (MMPs) and CD1a-positive Langerhans cells (LCs) analysed by immunohistochemical staining, and relative expression levels were compared between all seven sites. AOx alone did not reduce erythema. There was a significant reduction in pigmentation, and the product almost completely protected against LC depletion. AOx plus SS gave better protection against pigment formation and CK5/6 induction than SS alone. AOx alone protected against ssUVR-induced hyperproliferation, as shown by epidermal thickness and CK16 biomarkers, and was better than SS alone. Interestingly, although protection against induction of MMP-9, a marker of photoageing, did not reach significance when either SS or AOx were applied separately, there was complete protection against MMP-9 induction when these were combined. Non-SS materials such as AOx can contribute significantly to sun protection when added to a broad-spectrum SS and applied topically to human skin in vivo. [ABSTRACT FROM AUTHOR]

We report a 62-year-old Chinese woman with a 2-year history of lichen planus presenting with extensive violaceous maculopapules and plaques 1 week after taking an oral preparation of Chinese herbs. The patient developed vesiculobullous skin lesions 7 weeks later. Histopathological examination showed subepidermal blisters and adjacent bandlike lymphocytic infiltration. Direct immunofluorescence revealed linear deposits of IgG and C3 along the basement membrane zone. Indirect immunofluorescence showed IgG antibody deposition along the epidermal side of salt-split human skin. Circulating anti-bullous pemphigoid 180 antibodies were detected by ELISA. Lichen planus pemphigoides (LPP) was diagnosed. To our knowledge, this is the first report of LPP associated with oral Chinese herbs. [ABSTRACT FROM AUTHOR]

We measured and analyzed the subthreshold degradation of the gate-all-around (GAA) silicon nanowire field-effect transistors with the length of 300/500 nm and the radius of 5 nm. An analytical model incorporating the effect of interface traps quantitatively explained the measured subthreshold swing (SS) degradation. A simple electrostatic argument showed that the GAA device had smaller degradation of SS values than planar devices for the same interface trap densities. [ABSTRACT FROM PUBLISHER]