Mandibular Buccal Bifurcation Cyst:Report of Two Cases

Mandibular buccal bifurcation cyst is a rare inflammatory odontogenic cyst.We reported two cases who complained of painful swelling of extraoral soft tissue.Intraoral examination revealed the partially erupted mandibular first molar.Cone beam computed tomography showed a well-defined cystic lesion surrounding the first molar.Histopathologic images showed the cyst wall was infiltrated by a large number of plasma cells,neutrophils and eosinophils,and lined with a thin layer of non-keratinized stratified squamous epithelium.Finally,the two patients were diagnosed as mandibular buccal bifurcation cyst and treated with cyst enucleation and curettage.

Opto-thermoelectric pulling of light-absorbing particles

Optomechanics arises from the photon momentum and its exchange with low-dimensional objects.It is well known that optical radiation exerts pressure on objects,pushing them along the light path.However,optical pulling of an object against the light path is still a counter-intuitive phenomenon.Herein,we present a general concept of optical pulling-opto-thermoelectric pulling(OTEP)—where the optical heating of a light-absorbing particle using a simple plane wave can pull the particle itself against the light path.This irradiation orientation-directed pulling force imparts self-restoring behaviour to the particles,and three-dimensional(3D)trapping of single particles is achieved at an extremely low optical intensity of 10^(−2)mWμm^(−2).Moreover,the OTEP force can overcome the short trapping range of conventional optical tweezers and optically drive the particle flow up to a macroscopic distance.The concept of selfinduced opto-thermomechanical coupling is paving the way towards freeform optofluidic technology and lab-on-achip devices.

Light-driven single-cell rotational adhesion frequency assay

The interaction between cell surface receptors and extracellular ligands is highly related to many physiological processes in living systems.Many techniques have been developed to measure the ligand-receptor binding kinetics at the single-cell level.However,few techniques can measure the physiologically relevant shear binding affinity over a single cell in the clinical environment.Here,we develop a new optical technique,termed single-cell rotational adhesion frequency assay(scRAFA),that mimics in vivo cell adhesion to achieve label-free determination of both homogeneous and heterogeneous binding kinetics of targeted cells at the subcellular level.Moreover,the scRAFA is also applicable to analyze the binding affinities on a single cell in native human biofluids.With its superior performance and general applicability,scRAFA is expected to find applications in study of the spatial organization of cell surface receptors and diagnosis of infectious diseases.

Opto-thermoelectric microswimmers

Inspired by the“run-and-tumble”behaviours of Escherichia coli(E.coli)cells,we develop opto-thermoelectric microswimmers.The microswimmers are based on dielectric-Au Janus particles driven by a self-sustained electrical field that arises from the asymmetric optothermal response of the particles.Upon illumination by a defocused laser beam,the Janus particles exhibit an optically generated temperature gradient along the particle surfaces,leading to an opto-thermoelectrical field that propels the particles.We further discover that the swimming direction is determined by the particle orientation.To enable navigation of the swimmers,we propose a new optomechanical approach to drive the in-plane rotation of Janus particles under a temperature-gradient-induced electrical field using a focused laser beam.Timing the rotation laser beam allows us to position the particles at any desired orientation and thus to actively control the swimming direction with high efficiency.By incorporating dark-field optical imaging and a feedback control algorithm,we achieve automated propelling and navigation of the microswimmers.Our optothermoelectric microswimmers could find applications in the study of opto-thermoelectrical coupling in dynamic colloidal systems,active matter,biomedical sensing,and targeted drug delivery.

Mid-infrared superabsorbers based on quasi-periodic moiré metasurfaces

We report on mid-infrared superabsorbers based on quasi-periodic moiré metasurfaces in metal-insulator-metal form. By varying the spacer thickness, moiré rotation angle, and filling factor of the superabsorbers, we can tune narrowband or broadband absorption in a systematic way. With their high tunability of near-unity absorption and simple fabrication, in combination with decoupled mode theory for an efficient design, moiré superabsorbers are well-suited for a wide range of applications in sensing, imaging, and communication.