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Acoustic manipulation using surface acoustic wave has aroused widespread interest in life sciences, biomedical, and bioanalytical chemistry. Acoustic manipulation for different applications requires different acoustic fields. Bessel beams are non-diffractive and re-constructable, bringing possibility and versatility of acoustic manipulation integrated on microfluidic chips. To date, there are a few studies on constructing Bessel surface acoustic waves. Moreover, there is still a lack of dynamic acoustic manipulation using Bessel surface acoustic waves propagating along a surface of piezoelectric substrate with simple and high-precision devices. Here, we design a device with two omnidirectional equifrequency interdigital transducers to form a quasi-Bessel surface acoustic wave by means of coherent interference. The proposed device avoids influences of anisotropy on its operating frequency, making its quasi-Bessel beam accurately and stably conform to the predetermined design acoustic field. This acoustic field could control micrometer to submicrometer particles and dynamically move particles along lateral direction and axial direction of the propagation of quasi-Bessel beam. A phenomenon similar to negative force appeared when the two-micron spherical particles were manipulated. The quasi-Bessel beam formed by our device can provide a versatile movement for on-chip acoustic manipulation. [ABSTRACT FROM AUTHOR]

The bone lacunar-canalicular system (LCS) is a unique complex 3D microscopic tubular network structure within the osteon that contains interstitial fluid flow to ensure the efficient transport of signaling molecules, nutrients, and wastes to guarantee the normal physiological activities of bone tissue. The mass transfer laws in the LCS under microgravity and hypergravity are still unclear. In this paper, a multi-scale 3D osteon model was established to mimic the cortical osteon, and a finite element method was used to numerically analyze the mass transfer in the LCS under hypergravity, normal gravity and microgravity and combined with high-intensity exercise conditions. It was shown that hypergravity promoted mass transfer in the LCS to the deep lacunae, and the number of particles in lacunae increased more significantly from normal gravity to hypergravity the further away from the Haversian canal. The microgravity environment inhibited particles transport in the LCS to deep lacunae. Under normal gravity and microgravity, the number of particles in lacunae increased greatly when doing high-intensity exercise compared to stationary standing. This paper presents the first simulation of mass transfer within the LCS with different gravity fields combined with high-intensity exercise using the finite element method. The research suggested that hypergravity can greatly promote mass transfer in the LCS to deep lacunae, and microgravity strongly inhibited this mass transfer; high-intensity exercise increased the mass transfer rate in the LCS. This study provided a new strategy to combat and treat microgravity-induced osteoporosis. [ABSTRACT FROM AUTHOR]

Although the relationship between Western religiosity and innovation is widely investigated, the effect of Eastern religious traditions on corporate innovation remains unexplored. Using a sample of firms listed in Chinese A-share stock exchanges, we find that firms registered in areas with stronger Eastern religious traditions (Buddhism and Taoism) are generally more innovative than firms registered in areas with weaker Eastern religious traditions. This result suggests that Eastern religiosity promotes rather than stifles corporate innovation. We find additional evidence suggesting that Eastern religiosity promotes corporate innovation mainly through the following three channels: (1) fostering nonexclusivity and openness to science and innovation, (2) mitigating agency conflicts, and (3) nurturing commitment and fortitude. JEL Classifications: N35; D81; O31. [ABSTRACT FROM AUTHOR]

Grinding is a fundamental operation in craniotomy. Suitable grinding parameters will not only reduce force damage, but also ensure grinding efficiency. In this study, the regression equations of material removal rate and grinding force were obtained based on the theory of cortical bone grinding and full factorial test results, a multi-objective optimization based on the particle swarm algorithm was proposed for optimizing the grinding parameters: spindle speed, feed speed, and grinding depth in the grinding process. Two conflicting objectives, minimum grinding force and maximum material removal rate, were optimized simultaneously. The results revealed that the optimal grinding parameter combination and optimization results were as follows: spindle speed of 5000 rpm, feed rate of 60 mm/min, grinding depth of 0.6 mm, grinding force of 15.1 N, and material removal rate of 113.8 mm3/min. The parameter optimization result can provide theoretical guidance for selecting cortical bone grinding parameters in actual craniotomy. Graphical abstract [ABSTRACT FROM AUTHOR]

A three-dimensional model for osteocyte was established to research the mechanisms of mechano-transduction and amplification of primary cilium and osteocyte process in every gravity field. The results showed that significant stress concentration was observed in the area of physical connection between TES and the osteocyte process, where the fluid shear stress (FSS) was around two orders of magnitude higher than that in other areas. Due to the significant amplification effect of the TES structure on mechanical stimulation, making osteocyte process the "optimal mechanical receptor". In microgravity, the mechanical signal conduction ability of the osteocyte decreased significantly.. At the micro-nano scale, a 3D model for single bone lacunae-osteocyte system is established. The stress amplification mechanism of the transverse element is verified. Compared with the primary cilium, osteocyte process is the 'optimal mechanical receptor'. In microgravity, the mechanical signal conduction ability of osteocyte system decreased. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) can efficiently convert solar energy into electricity, which is considered a promising approach to reduce the dependence on fossil resources. However, the development of counter electrodes (CEs) has been limited. Hence, the search for efficient earth-abundant CE materials is highly desired. Herein, an improved simple synthesis method is reported for the deep optimization of electrode activity by coupling the N-defect carbon with the NiO/Fe2O3 heterojunction (denoted as NiO/Fe2O3@NC). The carbon layers with large specific surface area and high conductivity as bridging transporters not only can maintain structural stability but full exposure to active sites. Moreover, the synergetic effect of NiO and Fe2O3 can promote I3− reduction reaction and suppress iodide ion coupling simultaneously. The obtained NiO/Fe2O3@NC serves as CEs. Compared with the unsupported NiO@NC, the Fe2O3@NC composites displayed superior electrochemical properties. Meanwhile, the power conversion efficiency (PCE) of DSSC with NiO/Fe2O3@NC CE attained 8.69%, exceeding that with NiO@NC (6.51%), Fe2O3@NC (6.22%), and commercial Pt CEs (7.52%). This study would contribute to the construction and development of excellent electrocatalysts for other important reactions. [ABSTRACT FROM AUTHOR]

Surgery of nucleus pulposus removal is one of the methods used for the treatment of lumbar disc herniation in the clinic. In order to understand the strain states of the lumbar intervertebral disc (IVD) after nucleotomy, the axial compression experiments of porcine lumbar IVD were implemented using digital image correlation (DIC) technology. The normal IVDs are named as control group; the IVDs treated with trypsin by removing the nucleus pulposus are named as experimental group. The distributions and the change rules of both axial and radial strains in different regions of the IVD with load were studied, and the experimental results of two groups were compared. The results show that both axial and radial strains of different regions increased with stress in two groups, and the variation had non-uniformity. The axial strain in the posterior region of the annulus fibrosus (AF) was larger than that in the anterior region, and the inner AF was larger than that of the outer AF. The axial strain increase of the experimental group was larger than that of the control group obviously. In the posterior region, the radial strain increase was larger than that in the anterior region, and the outer AF was significantly larger than that of the inner AF. The radial strain direction of the experimental group in the inner AF was towards the center of the nucleus pulposus, which was opposite to that of the control group, and the radial strain increase was evidently smaller than that of the control group. In the outer AF, the radial strain direction of the experimental group was the same as that of the control group and the radial strain increase was significantly larger than that. [ABSTRACT FROM AUTHOR]

Collagen, as a structural protein, is widely distributed in the human body. Many factors influence collagen self-assembly in vitro, including physical-chemical conditions and mechanical microenvironment, and play a key role in driving the structure and arrangement. However, the exact mechanism is unknown. The purpose of this paper is to investigate the changes in the structure and morphology of collagen self-assembly in vitro under mechanical microenvironment, as well as the critical role of hyaluronic acid in this process. Using bovine type I collagen as the research object, collagen solution is loaded into tensile and stress-strain gradient devices. The morphology and distribution of collagen is observed using an atomic force microscope while changing the concentration of collagen solution, mechanical loading strength, tensile speed, and ratio of collagen to hyaluronic acid. The results demonstrate that the mechanics field governs collagen fibers and changes their orientation. Stress magnifies the differences in results caused by different stress concentrations and sizes, and hyaluronic acid improves collagen fiber orientation. This research is critical for expanding the use of collagen-based biomaterials in tissue engineering. [ABSTRACT FROM AUTHOR]