Publications by authors named "Xiaosong Tang"

Introduction: Unresectable hilar cholangiocarcinoma (UHC) is a malignant tumor and has a poor prognosis. IRE is a novel non-thermal ablative therapy that causes cellular apoptosis electrical impulses. To compare the curative effect for UHC, chemotherapy plus concurrent IRE and chemotherapy alone were set up.

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Camouflage is critical for many living organisms to survive in the natural world and has stimulated applications, such as optical cloaking and military affairs. However, most applications adopt crypsis-type camouflage that prevents the organisms from being detected by matching the environment, which is challenging to realize the large angle-of-view and broadband operation at optical frequencies. Here, as inspired by nature's system of masquerade, we demonstrate an optical masquerade, being detected but not recognized, with perturbative metasurfaces that could camouflage an object into another unrelated one under the oblique (±69°) illumination of visible light with an ∼160 nm bandwidth.

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Article Synopsis
  • Photonic crystal split-beam nanocavities are innovative structures that enhance optomechanical transductions but suffer from low optical quality factors.
  • Researchers have designed a new one-dimensional model that significantly improves the optical quality factor using a combination of deterministic methods and hill-climbing algorithms.
  • Experimental results show that the optimized nanocavity can achieve a quality factor as high as 1.99×10(4) and maintain performance even with lateral offsets, leading to potential applications like sensitive torque sensors and all-optical filters.
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  • Nanoscale all-optical circuits driven by optical forces show promise for energy-efficient communication, computation, and sensing devices.
  • Researchers successfully demonstrated the use of resonance modes in photonic crystal cavities to create both attractive (-6.2 nN) and repulsive (1.9 nN) optical forces with minimal power input.
  • By using integrated nanoelectromechanical systems, they separated the shifts caused by the optomechanical effect from those due to thermal effects, finding that optomechanical shifts are significantly more efficient at converting light energy into mechanical energy.
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  • A novel split-ladder photonic crystal cavity was designed to allow tuning by simply adjusting its gap width, differing from traditional coupled cavities that show more complex resonance behavior.
  • Simulations reveal that the cavity can achieve bipolar resonance tuning, exhibiting both red and blue shifts in its fundamental and second-order resonances, with a linear relationship to gap width changes.
  • Experiments using a comb drive actuator confirmed that increasing the cavity's gap leads to a measurable blue shift in resonance wavelength, achieving a 17 nm shift with a 26 nm gap increase while maintaining a high Q-factor.
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Control of photonic crystal resonances in conjunction with large spectral shifting is critical in achieving reconfigurable photonic crystal devices. We propose a simple approach to achieve nano-mechanical control of photonic crystal resonances within a compact integrated on-chip approach. Three different tip designs utilizing an in-plane nano-mechanical tuning approach are shown to achieve reversible and low-loss resonance control on a one-dimensional photonic crystal nanocavity.

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We present dynamic tuning of optical resonance using microelectromechanical systems (MEMS)-driven coupled photonic crystal (PhC) nanocavities. The device consists of an air-suspended one-dimensional PhC nanocavity coupled to input and output waveguides and a perturbing nanocavity attached to a submicrometer MEMS comb drive. Resonance tuning is achieved through varying the gap between the two coupled cavities.

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The interaction between moving bubbles, vapor voids in liquid, can arguably represent the simplest dynamical system in continuum mechanics as only a liquid and its vapor phase are involved. Surprisingly, and perhaps because of the ephemeral nature of bubbles, there has been no direct measurement of the time-dependent force between colliding bubbles which probes the effects of surface deformations and hydrodynamic flow on length scales down to nanometers. Using ultrasonically generated microbubbles (approximately 100 microm size) that have been accurately positioned in an atomic force microscope, we have made direct measurements of the force between two bubbles in water under controlled collision conditions that are similar to Brownian particles in solution.

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We investigate the properties of latex particle templates required to optimize the development of ordered liquid bridge networks in evaporative lithography. These networks are key precursors in the assembly of solutions of conducting nanoparticles into large, optically transparent, and conducting microwire networks on substrates (Vakarelski, I. U.

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Dynamic forces between a 50 microm radius bubble driven towards and from a mica plate using an atomic force microscope in electrolyte and in surfactant exhibit different hydrodynamic boundary conditions at the bubble surface. In added surfactant, the forces are consistent with the no-slip boundary condition at the mica and bubble surfaces. With no surfactant, a new boundary condition that accounts for the transport of trace surface impurities explains variations of dynamic forces at different speeds and provides a direct connection between dynamic forces and surface transport effects at the air-water interface.

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Background: The recombination of homologous genes is an effective protein engineering tool to evolve proteins. DNA shuffling by gene fragmentation and reassembly has dominated the literature since its first publication, but this fragmentation-based method is labor intensive. Recently, a fragmentation-free PCR based protocol has been published, termed recombination-dependent PCR, which is easy to perform.

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Two types of non-homologous beta-carotene ketolases (CrtW and CrtO) were previously described. We report improvement of a CrtO-type of beta-carotene ketolase for canthaxanthin production in a methylotrophic bacterium, Methylomonas sp. 16a, which could use the C1 substrate (methane or methanol) as sole carbon and energy source.

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