Real-time measurement of pump beam polarization through the transmitted light intensity in a polarized alkali metal vapor cell.

A laser beam with left-/right-handed circular polarization is generally used to create the oriented atomic spins for precision measurements in a spin-exchange relaxation-free (SERF) co-magnetometer. The fluctuation of laser polarization interferes with the spin polarization of alkali metal atoms, leading to the system performance degradation. Here, we report a method for real-time polarization state measurement by using the transmitted light intensity of the pump beam passing through the vapor cell.

Accelerating T relaxation time measurements of noble gas using transverse low-frequency square-wave magnetic field modulation.

The longitudinal relaxation time (T) of noble gas nuclear spins is a critical parameter for evaluating the performance of an atomic comagnetometer, significantly influencing the signal-to-noise ratio of the system. Traditional measurement techniques, such as the free induction decay method combined with the spin growth technique (FIDSG), are time-consuming for gases with extended T durations, such as Ne, and are prone to substantial environmental variability. Here, we propose the transverse low-frequency square-wave magnetic field modulation (LSMM) method for the rapid measurement of T.

Engineering Zeolitic-Imidazolate-Framework-Derived Mo-Doped Cobalt Phosphide for Efficient OER Catalysts.

Designing a cheap, competent, and durable catalyst for the oxygen evolution reaction (OER) is exceedingly necessary for generating oxygen through a water-splitting reaction. In this project, we have designed a ZIF-67-originated molybdenum-doped cobalt phosphide (CoP) using a simplistic dissolution-regrowth method using NaMoO and a subsequent phosphidation process. This leads to the formation of an exceptional hollow nanocage morphology that is useful for enhanced catalytic activity.

Microclaw Array Fabricated by Single Exposure of Femtosecond Airy Beam and Self-Assembly for Regulating Cell Migratory Plasticity.

The highly aligned extracellular matrix of metastatic breast cancer cells is considered to be the "highway" of cancer invasion, which strongly promotes the directional migration of cancer cells to break through the basement membrane. However, how the reorganized extracellular matrix regulates cancer cell migration remains unknown. Here, a single exposure of a femtosecond Airy beam followed by a capillary-assisted self-assembly process was used to fabricate a microclaw-array, which was used to mimic the highly oriented extracellular matrix of tumor cells and the pores in the matrix or basement membrane during cell invasion.

Self-assembled micropillars fabricated by holographic femtosecond multi-foci beams forin situ trapping of microparticles.

Dynamic self-assembly of micropillars has found wide applications in targeted trapping, micro-crystallization and plasmonic sensing. Yet the efficient fabrication of micropillars array with high flexibility still remains a grand challenge. In this Letter, holographic femtosecond laser multi-foci beams (fs-MFBs) based on a spatial light modulator (SLM) is adopted to efficiently create micropillars array with controllable geometry and spatial distribution by predesigning the computer-generated holograms (CGHs).

Efficient fabrication of a high-aspect-ratio AFM tip by one-step exposure of a long focal depth holographic femtosecond axilens beam.

In this Letter, we demonstrate a laser fabrication strategy that uses the long focal depth femtosecond axilens laser beam to manufacture the high-aspect-ratio (HAR) micropillars and atomic force microscopy (AFM) probes by one-step exposure. The long depth of focus is generated by modulating laser beam focused at different positions. By adjusting the exposure height, the morphology of HAR micropillars can be tuned flexibly, and the micropillar with an ultra-high aspect ratio (diameter of 1.

Uniaxial Stretching of Cell-Laden Microfibers for Promoting C2C12 Myoblasts Alignment and Myofibers Formation.

Fiber-shaped cellular constructs have attracted increasing attention in the regeneration of blood vessels, nerve networks, and skeletal myofibers. Nevertheless, the generation of functional fiber-shaped cellular constructs suffers from limited appropriate microfiber-based fabrication approaches and the maintenance of regenerated tissue functions. Herein, we demonstrate a silicone-tube-based coagulant bath free method to fabricate tens of centimeters long cell-laden microfibers using single UV exposure without pretreatment of nozzles or microchannels.

Holographic femtosecond laser integration of microtube arrays inside a hollow needle as a lab-in-a-needle device.

In this Letter, the femtosecond laser holographic two-photon polymerization (HTPP) method is adopted to rapidly realize a unique lab-in-a-needle (LIN) device by manufacturing microtube arrays inside a needle. The HTPP method is to modulate a Gaussian beam into a ring Bessel beam by a spatial light modulator (SLM) loaded with a Bessel hologram, and can fabricate microtube arrays with controllable inside diameter (1-10 μm) and designable patterns on such complex three-dimensional (3D) substrates by optimizing experimental parameters. A single LIN device can be processed by this method in about 4 min, which is not possible with traditional micronano technology and is much faster than the traditional two-photon polymerization method (at least several hours).

Conical Hollow Microhelices with Superior Swimming Capabilities for Targeted Cargo Delivery.

Inspired by flagellate microorganisms in nature, the microhelix is considered as an ideal model for transportation in fluid environment with low Reynolds number. However, how to promote the swimming and loading capabilities of microhelices with controllable geometries remains challenging. In this study, a novel kind of conical hollow microhelices is proposed and a method is developed to rapidly fabricate these microhelices with controllable parameters by femtosecond vortex beams generated from spatial light modulation along helical scanning.

P absorption and removal mechanism of new Salix clone (A42)on eutrophic water with different P concentrations.

Phosphorus is the necessary element for plant growth, and its concentration is one of the main indices for water eutrophication. Hence, it is significant to understand how woody plants purify phosphorus in eutrophic water. The purpose of this study is to reveal the P absorption and removal mechanism of Salix matsudana in eutrophic water with different P concentration.

Microtubes with Complex Cross Section Fabricated by C-Shaped Bessel Laser Beam for Mimicking Stomata That Opens and Closes Rapidly.

This article presents a new method for fabricating complex cross-sectional microtubes with a high aspect ratio at micro/nanoscale. The microtubes are directly written in a photoresist using a femtosecond pulsed laser combined with a spatial light modulator (SLM). A new method for generating a C-shaped Bessel beam by modifying the Bessel beams with a SLM is reported for the first time.

High-aspect-ratio microtubes with variable diameter and uniform wall thickness by compressing Bessel hologram phase depth.

In this Letter, we present a light field regulation method to form a ring light field with controllable density distribution. This method is to compress the phase modulation depth of Bessel holograms superimposed with blazed gratings and tune the diffraction efficiency of the superimposed holograms by gray scale. The experimental light field generated by the superimposed holograms is consistent with the simulation results.

Combined effects of cadmium and tetrabromobisphenol a (TBBPA) on development, antioxidant enzymes activity and thyroid hormones in female rats.

Tetrabromobisphenol A (TBBPA) is one of the world's most widely used brominated flame retardants (BFRs) and considered as persistent halogenated contaminant. E-wastes contain a range of toxic chemicals, including BFRs and heavy metals, exerting adverse impacts to human health and environment. Nevertheless, comprehensive evaluation on combined toxicity of these co-existing pollutants is limited.

Generation of colorful Airy beams and Airy imaging of letters via two-photon processed cubic phase plates.

In this Letter, we demonstrate the observation of colorful Airy beams and Airy imaging of letters, which we called Airy letters here, generated through the continuous cubic phase microplate (CCPP) elaborately fabricated by femtosecond laser two-photon processing. The fabricated CCPP with both micro size (60  μm×60  μm×1.1  μm) and continuous variation of phase shows a good agreement with the designed CCPP.

Continuous cubic phase microplates for generating high-quality Airy beams with strong deflection.

Owing to the distinguishing properties of nondiffraction, self-healing, and transverse acceleration, Airy beams have attracted much attention in the past decade. To date, a simple approach for exquisitely fabricating cubic phase plates with both continuous variation of phase and micro size still remains challenging, which limits the generation of high-quality Airy beams for integrated micro-optics. Here, we report the elaborate design and fabrication of a continuous cubic phase microplate (CCPP) for generating high-quality Airy beams in micrometer scale.

Optimized holographic femtosecond laser patterning method towards rapid integration of high-quality functional devices in microchannels.

Rapid integration of high-quality functional devices in microchannels is in highly demand for miniature lab-on-a-chip applications. This paper demonstrates the embellishment of existing microfluidic devices with integrated micropatterns via femtosecond laser MRAF-based holographic patterning (MHP) microfabrication, which proves two-photon polymerization (TPP) based on spatial light modulator (SLM) to be a rapid and powerful technology for chip functionalization. Optimized mixed region amplitude freedom (MRAF) algorithm has been used to generate high-quality shaped focus field.

Toxic Effects of Tetrabromobisphenol A on Thyroid Hormones in SD Rats and the Derived-reference Dose.

The present study determined the thyroid hormone interference of tetrabromobisphenol A (TBBPA) in Sprague-Dawley (SD) rats, and the derived-reference dose (RfD) of different endpoint effects on mammals based on experimental results and data collection. Based on repeated exposure toxicity tests on mammals and extensive research, the present study used BMDS240 Software to derive a benchmark dose, and analyzed the accuracy and uncertainty, and similarity with other studies. Test results on triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) demonstrated that all the indicators presented a non-monotonous dose-effect relationship clearly, except TSH in male rats exposed to 0-1000 mg/kg BW per day.