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A variable optical attenuator (VOA) is a crucial component for optical communication, especially for a variable multiplexer (VMUX) and reconfigurable optical add-drop multiplexer (ROADM). With the capacity increasing dramatically, a large-port-count and low-power-consumption VOA array is urgent for an on-chip system. In this paper, we experimentally demonstrate a 16-channel VOA array based on a polymer/silica hybrid waveguide. The proposed array is able to work over C and L bands. The VOA array shows an average attenuation larger than 14.38 dB with a low power consumption of 15.53 mW. The low power consumption makes it possible to integrate silica-based passive devices with a large port count on-chip. [ABSTRACT FROM AUTHOR]

High entropy alloy nanopowders were successfully prepared by liquid-phase reduction methods and their applications were preliminarily discussed. The prepared high entropy alloy nanopowders consisted of FeNi alloy spherical powders and NiFeCoCrY alloy spherical powders with a particle size of about 100 nm. The powders have soft magnetic properties, the saturation magnetization field strength were up to 5000 Qe and the saturation magnetization strength Ms was about 17.3 emu/g. The powders have the excellent property of low high-frequency loss in the frequency range of 0.3–8.5 GHz. When the thickness of the powders coating was 5 mm, the powders showed excellent absorption performance in the Ku band; and when the thickness of the powders coating was 10 mm; the powders showed good wave-absorbing performance in the X band. The powders have good moulding, and the powders have large specific surface area, so that the magnetic powder core composites could be prepared under low pressure and without coating insulators, and the magnetic powder cores showed excellent frequency-constant magnetization and magnetic field-constant magnetization characteristics. In the frequency range of 1~100 KHz; the μm of the magnetic powder core heat-treated at 800 °C reached 359, the μe was about 4.6 and the change rate of μe with frequency was less than 1%, meanwhile; the magnetic powder core still maintains constant μe value under the action of the external magnetic field from 0 to 12,000 A/m. The high entropy alloy nanopowders have a broad application prospect in soft magnetic composites. [ABSTRACT FROM AUTHOR]

The previous study successfully established an expression strain of ζ-carotene-like compounds (CLC) and demonstrated its remarkable antioxidant activity, which exhibited resistance to photodamage caused by UVB radiation on the skin following gavage administration. The objective of this study was to investigate the impact and mechanism of CLC on UVB-induced skin damage through topical application. Cell viability, anti-apoptotic activity, ROS scavenging ability, the inhibition of melanin synthesis, the regulation of inflammatory factors and collagen deposition were assessed in cells and mice using qRT-PCR, WB, Elisa assays, immunohistochemistry staining and biochemical kits, etc. The experimental results demonstrated that CLC-mitigated apoptosis induced by UVB irradiation up-regulated the Keap1/Nrf2/ARE antioxidant pathway to attenuate levels of ROS and inflammatory factors (NF-κB, TNF-α, IL-6 and IL-β), and suppressed MAPK/AP-1 and CAMP/PKA/CREB signaling pathways to mitigate collagen degradation, skin aging and melanin formation. In conclusion, this study underscored the potential of CLC as a safe and efficacious source of antioxidants, positioning it as a promising ingredient in the formulation of cosmetics targeting anti-aging, skin brightening and sunburn repair. [ABSTRACT FROM AUTHOR]

Low-power-consumption optical devices are crucial for large-scale photonic integrated circuits (PICs). In this paper, a three-dimensional (3D) polymer variable optical attenuator (VOA) is proposed. For monolithic integration of silica and polymer-based planar lightwave circuits (PLCs), the vertical VOA is inserted between silica-based waveguides. Optical and thermal analyses are performed through the beam propagation method (BPM) and finite-element method (FEM), respectively. A compact size of 3092 μm × 4 μm × 7 μm is achieved with a vertical multimode interference (MMI) structure. The proposed VOA shows an insertion loss (IL) of 0.58 dB and an extinction ratio (ER) of 21.18 dB. Replacing the graphene heater with an aluminum (Al) electrode, the power consumption is decreased from 29.90 mW to 21.25 mW. The rise and fall time are improved to 353.85 μs and 192.87 μs, respectively. The compact and high-performance VOA shows great potential for a variety of applications, including optical communications, integrated optics, and optical interconnections. [ABSTRACT FROM AUTHOR]

In this paper, a polymer/silica hybrid waveguide thermo-optic variable optical attenuator (VOA), covering the O-band, is demonstrated. The switch is fabricated by simple and low-cost direct ultraviolet (UV) lithography. The multimode interferences (MMIs) used in the Mach–Zehnder interferometer (MZI)-VOA are well optimized to realize low loss and large bandwidth. The VOA shows an extinction ratio (ER) of 18.64 dB at 1310 nm, with a power consumption of 8.72 mW. The attenuation is larger than 6.99 dB over the O-band. The rise and fall time of the VOA are 184 μs and 180 μs, respectively. [ABSTRACT FROM AUTHOR]

The exopolysaccharide (EPS) produced by Lactiplantibacillus plantarum NMGL2 isolated from traditional fermented dairy cheese was purified chromatographically with DEAE-Sepharose and Sepharose CL-6B columns. The purified EPS was characterized by various physicochemical methods and in vitro fecal microbiota regulation assay. The results showed that the EPS had a relatively low molecular weight of 3.03 × 104 Da, and it had a relatively high degradation temperature of 245 °C as determined by differential scanning calorimetry. Observation of the EPS by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy revealed a highly branched and tangled fibrous network microstructure with many hollow microtubules and spherical particles. Structural study by 1H NMR spectroscopy suggested that the EPS contained a tetrasaccharide repeating unit with monosaccharide components of β-galactose (4.6%), α-glucose (20.6%), and α-mannose (74.8%). The EPS was highly resistant to hydrolysis of simulated human saliva, gastric, and intestinal juices. Moreover, the EPS beneficially affected the composition and diversity of the fecal microbiota, e.g., increasing the relative abundance of Firmicutes and inhibiting that of Proteobacteria. The results of this study indicated significant bioactivity of this novel low-molecular-weight EPS produced by Lpb. plantarum NMGL2, which could serve as a bioactive agent for potential applications in the food and health care industry. [ABSTRACT FROM AUTHOR]

Chito-oligosaccharides (COSs) were encapsulated by the film-ultrasonic method into three nano-liposomes, which were uncoated liposomes (COSs-Lip), chitosan-coated liposomes (CH-COSs-Lip), and sodium alginate (SA)/chitosan (CH)-coated liposomes (SA/CH-COSs-Lip). The physicochemical and structural properties, as well as the stability and digestive characteristics, of all three nano-liposomes were assessed in the current study. Thereafter, the characteristics of intestinal absorption and transport of nano-liposomes were investigated by the Caco-2 cell monolayer. All nano-liposomes showed a smaller-sized distribution with a higher encapsulation efficiency. The ζ-potential, Z-average diameter (Dz), and polydispersity index (PDI) demonstrated that the stability of the SA/CH-COSs-Lip had much better stability than COSs-Lip and CH-COSs-Lip. In addition, the transport of the nano-liposomes via the Caco-2 cell monolayer indicated a higher transmembrane transport capacity. In summary, the chitosan and sodium alginate could serve as potential delivery systems for COSs to fortify functional foods and medicines. [ABSTRACT FROM AUTHOR]

To understand the mechanism of tolerance of lactic acid bacteria (LAB) during cold storage of fermented milk, 31 LAB strains were isolated from traditional fermented products, and Lactiplantibacillus plantarum NMGL2 was identified with good tolerance to both cold and acid stresses. Data-independent acquisition proteomics method was employed to analyze the response of Lpb. plantarum NMGL2 to the combinational cold and acid stresses during storage of the fermented milk made with the strain at 4 °C for 21 days. Among the differentially expressed proteins identified, 20 low temperature-resistant proteins and 10 acid-resistant proteins were found. Protein interaction analysis showed that the low temperature-resistant proteins associated with acid-resistant proteins were Hsp1, Hsp2, Hsp3, CspC, MurA1, MurC, MurD, MurE1, and MurI, while the acid-resistant proteins associated with low temperature-resistant proteins were DnaA, DnaK, GrpE, GroEL, and RbfA. The overall metabolic pathways of Lpb. plantarum NMGL2 in response to the stresses were determined including increased cell wall component biosynthesis, extracellular production of abundant glycolipids and glycoproteins, increased expression of F1Fo-ATPase, activation of glutamate deacidification system, enhanced expression of proteins and chaperones associated with cell repairing caused by the acidic and cold environment into the correct proteins. The present study for the first time provides further understanding of the proteomic pattern and metabolic changes of Lpb. plantarum in response to combinational cold and acid stresses in fermented milk, which facilitates potential application of Lpb. plantarum in fermented foods with enhanced survivability. [ABSTRACT FROM AUTHOR]

There has been an increased application of exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) in fermented dairy products, but interactions between EPS and casein (CAS), and bioactivities of their complex are poorly studied. In this study, EPS produced by Lactobacillus plantarum YW11 (EPS-YW11) was studied for interactions with CAS in a simulated fermentation system acidified by D-(+)-gluconic acid δ-lactone. The results showed that there was interaction between EPS-YW11 and CAS when EPS (up to 1%, w/v) was added to the casein solution (3%, w/v) as observed with increased viscoelasticity, water holding capacity, ζ-potential and particle size of EPS-YW11/CAS complex compared with CAS alone. Microstructural analysis showed that a higher concentration of EPS facilitated more even distribution of CAS particles that were connected through the polysaccharide chains. Infrared spectroscopy further confirmed interactions between EPS and CAS by intermolecular hydrogen bonding, electrostatic and hydrophobic contacts. Further evaluation of the bioactivities of EPS-YW11/CAS complex revealed significantly increased antibiofilm, antioxidation, and bile acids binding capacity. The present study provides further understanding on the mechanism of interactions between EPS produced by LAB and CAS, which would benefit potential applications of EPS in fermented dairy products with enhanced functionality. [ABSTRACT FROM AUTHOR]