Ablation of porcine subcutaneous fat and porcine aorta tissues by a burst-mode nanosecond-pulsed laser at 355 nm.

High-energy laser pulses used in laser angioplasty are challenging the laser cost, delivery system damage, efficiency, and laser catheter operating time. 355 nm nanosecond-pulsed laser in burst mode has shown potentials in reducing the system complexity and selective ablation of tissues. In this paper, burst mode laser ablation of porcine subcutaneous fat and porcine aorta is investigated.

Ultrafast inactivation of SARS-CoV-2 with 266 nm lasers.

Disinfection eliminates pathogenic microorganisms and ensures a biosafe environment for human beings. The rapid spread of COVID-19 is challenging traditional disinfection methods in terms of reducing harmful side effects and conducting faster processes. Spraying large-scale chemical disinfectants is harmful to individuals and the environment, while UV lamp and light-emitting diode (LED) disinfection still requires a long exposure time due to the low irradiance and highly divergent beam characteristics.

Development of a deep-ultraviolet pulse laser source operating at 234 nm for direct cooling of Al ion clocks.

We report on the development of a 250-MHz 234 nm deep-ultraviolet pulse source based on a flexible wavelength-conversion scheme. The scheme is based on a frequency-doubled optical parametric oscillator (FD-OPO) together with a cascaded frequency conversion process. We use a χ nonlinear envelope equation to guide the design of an intra-cavity OPO crystal, demonstrating a flexible broadband tunable feature and providing as high as watt-level of a frequency-doubled signal output centered at 850 nm, which is served as an input wave for the cascaded frequency conversion process.

Mode instabilities in Yb:YAG crystalline fiber amplifiers.

Mode instabilities (MI) threshold in the Yb:YAG crystalline fiber amplifier is simulated by a full numerical model. The propagation of signal fields is simulated by the finite-difference beam-propagation method combined with the rate equations, and the time-dependent heat equation is solved by the alternating-direction-implicit method. Considering the strong temperature-dependent laser performance of Yb:YAG, an iterative method is applied to reach the steady state of Yb:YAG, the crystalline fiber amplifier, before the simulation of MI behavior.

Impact of the heat load on the laser performance of chirally-coupled-core fibers.

As the heat load within the central core of chirally-coupled-core (CCC) fibers will change the pre-designed refractive index profile through the thermo-optic effect, its impact on the laser performance of CCC fibers is investigated. Analysis and simulation results on two typical CCC fibers show that the effects of the heat load include the modal loss reduction and the transmission spectrum drift. The former comes from the thermal lensing effect in the central core, and the latter is caused by the change in the refractive index difference between the central core and the side core.

Role of Wnt/β-catenin signaling pathway in the mechanism of calcification of aortic valve.

Aortic valve calcification is a common disease in the elderly, but its cellular and molecular mechanisms are not clear. In order to verify the hypothesis that Wnt/β-catenin signaling pathway is involved in the process of calcification of aortic valve, porcine aortic valve interstitial cells (VICs) were isolated, cultured and stimulated with oxidized low density lipoprotein (ox-LDL) for 48 h to induce the differentiation of VICs into osteoblast-like cells. The key proteins and genes of Wnt/β-catenin signaling pathway, such as glycogen synthase kinase 3β (GSK-3β) and β-catenin, were detected by using Western blotting and real-time polymerase chain reaction (PCR).