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Creators/Authors contains: "Liu, Xiaolong"

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  1. ; ; ; ; ; ; ( , Angewandte Chemie International Edition)
    Bilayer (BL) two-dimensional boron (i.e., borophene) emerges very recently and holds promise for fascinating physical properties and a variety of electronic applications. Despite this potential, the fundamental chemical properties of BL borophene which form the critical foundation of practical applications has been unexplored. Here, we present atomic-level chemical studies of BL borophene using ultrahigh vacuum tip-enhanced Raman spectroscopy (UHV-TERS). UHV-TERS identifies the vibrational fingerprint of BL borophene from mixed-dimensional borophene polymorphs with angstrom-scale chemical spatial resolution. The observed Raman mode is directly correlated with the vibrations of interlayer boron-boron bonds, validating the three-dimensional lattice geometry of BL borophene. By virtue of the single-bond sensitivity of UHV-TERS to oxygen adatoms, we demonstrate the enhanced chemical stability of BL borophene compared to its monolayer counterpart by exposure to controlled oxidizing atmospheres under UHV. In addition to revealing fundamental chemical insights into BL borophene, this work establishes UHV-TERS as a powerful tool to probe interlayer bonding and chemical properties of layered materials at the atomic scale. 
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    Free, publicly-accessible full text available June 15, 2024
  2. ; ; ; ; ; ; ; ; ; ; et al ( , IEEE Robotics and Automation Letters)
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  3. ; ; ; ; ; ; ; ( , ACS Sensors)
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  4. ; ; ; ; ; ; ; ( , Journal of the American Chemical Society)
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  5. ; ; ; ; ; ; ; ; ; ; et al ( , Proceedings of the National Academy of Sciences)
  6. ; ; ; ( , The International Journal of Medical Robotics and Computer Assisted Surgery)
    Abstract Background

    Insertable laparoscopic camera systems were developed to improve the minimally invasive surgeries. Robotic degrees of freedom for an insertable laparoscopic camera are required to adjust the camera's orientation and position inside an abdominal cavity.

     Methods

    This paper demonstrates an insertable magnetic actuated robotic camera system with two‐degree‐of‐freedom (2‐DoF) orientation control for single incision laparoscopic surgery. The camera system design consists of an external magnetic control unit and a fully insertable camera capsule. This system features a unified mechanism for anchoring, navigating, and rotating the insertable camera capsule by externally generated rotational magnetic field from the control unit. The motor‐free camera capsule is encapsulated in an one‐piece housing with two ring‐shaped tail‐end magnets and one cylindrical central magnet. The control unit that positioned externally consists of both permanent magnets and electromagnetic coils to generate rotational magnetic field and control the camera capsule.

     Results

    The experimental investigations indicated that the camera control system can achieve less than 1° control accuracies with average errors 0.594° and 0.524° for tilt motion and pan motion, respectively.

     Conclusion

    The designed control system provides fine orientation control for the insertable camera capsule which guarantees proper vision for the surgeon during single incision laparoscopic surgery.

     
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  7. ; ; ; ; ; ; ; ; ; ( , Proceedings of the National Academy of Sciences)
  8. ; ( , Advanced Materials)
  9. ; ; ; ; ; ; ; ; ( , Applied Physics Letters)
  10. ; ; ; ; ; ; ; ; ; ; et al ( , Communications Biology)
    Abstract

    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressingE. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals  <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.

     
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