Practical method for improving the accuracy of weakly stressed birefringence detection by circularly polarized instantaneous photoelasticity.

Due to the mismatch between the quarter-wave plate and the wavelength of the light source, the circularly polarized field photoelastic stress analysis method has an impact on the measurement of the phase delay and the stress direction angle. In particular, the measurement of the phase delay is inaccurate for weakly stressed samples with phase delays less than a quarter-wavelength. In this paper, we first give a method for calculating the mismatch value , which requires only one air calibration without prior calibration of the parameters of the quarter-wave plate with other equipment.

A novel motionless calibration method for augmented reality surgery navigation system based on optical tracker.

Augmented reality (AR) surgery navigation systems display the pre-operation planned virtual model at the accurate position in the real surgical scene to assist the operation. Accurate calibration of the mapping relationship between the virtual coordinate and the real world is the key to the virtual-real fusion effect. Former calibration methods require the doctor user to conduct complex manual procedures before usage.

Application of mixed reality-based surgical navigation system in craniomaxillofacial trauma bone reconstruction.

Objectives: This study aimed to build a surgical navigation system based on mixed reality (MR) and optical positioning technique and evaluate its clinical applicability in craniomaxillofacial trauma bone reconstruction. Me-thods We first integrated the software and hardware platforms of the MR-based surgical navigation system and explored the system workflow. The systematic error, target registration error, and osteotomy application error of the system were then analyzed via 3D printed skull model experiment.

Polyvinylpyrrolidone-assisted synthesis of highly water-stable cadmium-based metal-organic framework nanosheets for the detection of metronidazole.

Recently, much effort has been dedicated to ultra-thin two-dimensional metal-organic framework (2D MOF) nanosheets due to their outstanding properties, such as ultra-thin morphology, large specific surface area, abundant modifiable active sites, However, the preparation of high-quality 2D MOF nanosheets in good yields still remains a huge challenge. Herein, we report 2D cadmium-based metal-organic framework (Cd-MOF) nanosheets prepared in a one-pot polyvinylpyrrolidone (PVP)-assisted synthesis method with high yield. The Cd-MOF nanosheets were characterized with good stability and dispersion in aqueous systems, and were highly selective and sensitive to the antibiotic metronidazole (MNZ) with low limit of detection (LOD: 0.

Biomimetic apposition compound eye fabricated using microfluidic-assisted 3D printing.

After half a billion years of evolution, arthropods have developed sophisticated compound eyes with extraordinary visual capabilities that have inspired the development of artificial compound eyes. However, the limited 2D nature of most traditional fabrication techniques makes it challenging to directly replicate these natural systems. Here, we present a biomimetic apposition compound eye fabricated using a microfluidic-assisted 3D-printing technique.

A rapid nucleic acid concentration measurement system with large field of view for a droplet digital PCR microfluidic chip.

Droplet digital polymerase chain reaction (ddPCR) is an effective technique, with unparalleled sensitivity, for the absolute quantification of target nucleic acids. However, current commercial ddPCR devices for detecting the gene chip are time consuming due to complex image stitching. To address this issue, we propose a universal concentration determination system and realize one-time gene chip imaging with high resolution.

Electrodeposition immobilized molybdenum disulfide quantum dots and their electrochemiluminescence application in the detection of melamine residues in milk powder.

In this paper, one-step hydrothermal and electrodeposition methods were used to prepare a MoS2 quantum dot (QD) solid-phase electrochemiluminescent (ECL) electrode for the detection of melamine residues in milk powder. With the assistance of chitosan, MoS2 QDs fixed by the one-step electrodeposition method show better ECL performance than those by traditional deposition methods due to better dispersibility and stability. Based on the quenching of the MoS2 QDs ECL signal by melamine, quantitative detection of melamine in the sample was performed.

Molecular Engineering of Aromatic Imides for Organic Secondary Batteries.

Aromatic imides are a class of attractive organic materials with inherently electroactive groups and large π electron-deficient scaffolds, which hold potential as electrode materials for organic secondary batteries (OSBs). However, the undecorated aromatic imides are usually plagued by low capacity, high solubility in electrolyte, and poor electronic/ionic conductivity. Molecular engineering has been demonstrated to be an effective strategy to address unsatisfying characteristics of the aromatic imides, thereby expanding their scope for applications in OSBs.

High-throughput and uniform large field-of-view multichannel fluorescence microscopy with super-thin dichroism for a dPCR gene chip.

With the rapid development of digital precision medicine, the digital polymerase chain reaction (dPCR) deoxyribonucleic acid (DNA) gene chip integrates more channels with smaller size and larger area, which leads to a higher technical requirement for commercial optical fluorescence microscopy. The multitime image splicing method is widely used for DNA detection. However, it consumes time and has visible seamless image results.

Experimental analysis of a wavefront coding system with a phase plate in different surfaces.

The application of an integrated phase plate can greatly simplify an optical system structure due to the defocus insensitivity and aberration inhibition of the wavefront coding imaging technology. In addition, the development of free-form surface technology promotes the application of integrated phase plates. In order to view the imaging characteristics of the integrated wavefront coding system, we built two kinds of wavefront coding systems with the phase plate integrated in different surfaces of the optical system.

Colour compound lenses for a portable fluorescence microscope.

In this article, we demonstrated a handheld smartphone fluorescence microscope (HSFM) that integrates dual-functional polymer lenses with a smartphone. The HSFM consists of a smartphone, a field-portable illumination source, and a dual-functional polymer lens that performs both optical imaging and filtering. Therefore, compared with the existing smartphone fluorescence microscope, the HSFM does not need any additional optical filters.

Design and Fabrication of Wafer-Level Microlens Array with Moth-Eye Antireflective Nanostructures.

Wafer-level packaging (WLP) based camera module production has attracted widespread industrial interest because it offers high production efficiency and compact modules. However, suppressing the surface Fresnel reflection losses is challenging for wafer-level microlens arrays. Traditional dielectric antireflection (AR) coatings can cause wafer warpage and coating fractures during wafer lens coating and reflow.

(E)-2-Phenyl-N-tosyl-non-2-en-4-ynamide.

The mol-ecule of the title compound, C22H23NO3S, adopts an E conformation about the C=C bond. The dihedral angle between the benzene rings is 23.79 (5)°.

Quasi-common-path laser feedback interferometry based on frequency shifting and multiplexing.

We present a quasi-common-path laser feedback interferometer based on frequency shifting and multiplexing. The interferometer uses two acousto-optic modulators to shift the frequency of the target-generated feedback light by 2 Omega. A properly aligned mirror is inserted into the feedback path to generate a feedback light frequency shifted by Omega.

[Determination of deoxyribonucleic acid with acridine orange by resonance light scattering technique].

The resonance light scattering (RLS) spectra of acridine orange with deoxyribonucleic acid have been studied. The RLS of acridine orange is greatly enhanced by deoxyribonucleic acid in pH 11. There is a resonance light scattering peak at 324 nm.