Facile production of low-viscosity mung bean starch through cold plasma treatment: Improvement of film formability.

Mung bean starch (MBS) has a strong potential to be used as food packages. However, preparing tough and uniform MBS films via industrial casting remains challenging due to the high viscosity of MBS slurry. Herein, MBS was modified by using dielectric barrier discharge cold plasma (CP) in an attempt to decrease its viscosity and improve the film-forming properties. Results indicated that CP with an applied power of 120 W for 5 min decreased the peaking viscosity of MBS slurry from 2936.5 to 466.3 cP. Moreover, CP treatment simultaneously modified the crystallinity (20.2%-16.7%), amylose content (30.5%-44.3%), and short-range orders (1.04-0.85). CP also broke the protective envelope of MBS granules. Further, the film-forming properties of MBS were investigated. It was observed that CP-modified MBS film casts exhibited uniform morphology, higher tensile strength (6.6-9.6 MPa), and improved thermal stability (89.0-100.8°C) compared with the untreated MBS film. The study indicates that the CP can be used as a green and facile technology to improve the properties of MBS films resulting in an efficient food packing material.

Cold plasma treatment with alginate oligosaccharide improves the digestive stability and bioavailability of nutrient-delivered particles: An in vitro INFOGEST gastrointestinal study.

To improve the stability and bioavailability of the delivered hydrophobic nutrients, the zein-based delivery system was modified by alginate oligosaccharide (AOS), cold plasma (CP) treatments, and synergistically. The digestive behavior of each was investigated in an INFOGEST static in vitro digestion model. The results showed that AOS and CP treatments and their synergistic effects improved the dispersion and stability of the delivery system, leading to a more concentrated particle size distribution and higher particle surface charge. Both CP treatments and AOS increased the release rate of Curcumin (Cur) at small intestine (11.8 % to 20.5 % and 11.8 % to 24.64 %, respectively), and the synergistic effect was higher (11.8 % to 43.84 %). The wall material modified showed a higher encapsulation efficiency of Cur (52.83 % to 85.17 %). Cur release rate measurements showed that the wall material modified could have a positive effect on the slow release of Cur. SDS-page electrophoresis revealed that the slow release was due to the enhanced resistance of wall material to digestive fluids. Thus, treatment with AOS and CP treatments, and the synergism are suitable for modifying zein-based delivery systems for the encapsulation, stabilization, and slow release of hydrophobic nutrients during digestion in the field of functional foods.

A Kernel-Based Multi-Featured Rock Modeling and Detection Framework for a Mars Rover.

This article presents two kernel-based rock detection methods for a Mars rover. Rock detection on planetary surfaces is particularly pivotal for planetary vehicles regarding navigation and obstacle avoidance. However, the diverse morphologies of Martian rocks, the sparsity of pixel-wise features, and engineering constraints are great challenges to current pixel-wise object detection methods, resulting in inaccurate and delayed object location and recognition. We therefore propose a region-wise rock detection framework and design two detection algorithms, kernel principle component analysis (KPCA)-based rock detection (KPRD) and kernel low-rank representation (KLRR)-based rock detection (KLRD), using hypotheses of feature and sub-spatial separability. KPRD is based on KPCA and is expert in real-time detection yet with less accurate performance. KLRD is based on KPRD with KLRR which can generate more precise rock detection results with less delay. To validate the efficiency of the proposed methods, we build a small-scale Martian rock dataset, MarsData, containing various rocks. Preliminary experimental results show that our methods are efficient in dealing with complex images containing rocks, shadows, and gravel. The code and data are available at: https://github.com/CVIR-Lab/MarsData.

Structure, stability, and mechanism of dextran-CPP-Ca2+ conjugates: A novel high-efficiency calcium ion delivery system.

Calcium has limited bioavailability because of the formation of calcium phosphate deposits in the gastrointestinal tract. In this study, we prepared a dextran-casein phosphopeptide (CPP)-Ca2+ delivery system and evaluated for Ca2+ binding mechanism, structure, stability, and sustained release of Ca2+ and assessed inhibition of calcium phosphate precipitation. The results revealed that Ca2+ binds to dextran-CPP through the phosphate, carboxyl, and amino groups and forms crystal clusters. Furthermore, compared with single polymer CPP-Ca2+ conjugates, copolymer dextran-CPP-Ca2+ conjugates exhibited improved stability at various conditions (pH, temperature, and coexisting food), efficiently reduced the calcium phosphate precipitation, and improved sustained-release of Ca2+. Collectively, dextran-CPP-Ca2+ conjugates can be an efficient Ca2+ delivery system.

Effects of high temperature, high humidity, and cold storage on structure and qualities of whole oat flour noodles during processing.

Gelation and structure of oat starch significantly affect qualities of whole oat flour noodles. During extrusion, the structure of noodles is loose, resulting in high cooking loss and poor texture. Therefore, oat noodles were treated with high temperature, high humidity (HTH), and cold storage (CS), and their structure and qualities were analyzed. The results showed that compared with CS, HTH could reduce the cooking loss of noodles from 10.12% to 6.13%, increase the hardness (65.59 g) and chewiness (20.67) of noodles, and effectively improve the sensory quality of noodles. The change in texture and sensory of noodles was due to HTH by accelerating the retrogradation of starch in noodles, promoting the cross-linking of starch molecules to form an ordered structure, causing an increase in the ordered degree and crystallinity of starch and making the structure of noodles denser. It made the mobility of water in the noodles decrease, and more tightly bound water was transformed into weakly bound water and free water. HTH can be applied to industrial production of whole oat flour noodles. This study could effectively guide the production of high-quality whole oat flour noodles without any food additives.

Novel Dark Current Reduction Strategy via Deep Bulk Traps for High-Performance Solution-Processed Organic Photodetectors.

The performance improvement of the organic photodetectors (OPDs) focuses on suppressing the dark current density (Jd) to improve the specific detectivity. In this work, a dark current reduction strategy relying on constructing limited deep traps in the active layer to suppress charge injection rate was newly proposed. And an optimization method has been successfully demonstrated on the solution-processed OPDs accordingly. Compared with the Jd expressed by the OPD with the shallow trap system, the device with deep bulk traps exhibits a dramatically reduced dark current while ensuring high responsivity. At a bias of -2 V, the optimized photodiode with a Jd down to 1.4 × 10-5 mA cm-2 and a maximum responsivity of 0.42 A W-1 @620 nm was realized, leading to a maximum detectivity calculated from shot noise of 6.23 × 1012 Jones. This value is 49-fold higher than that of the original OPD with the same structure. The effects of deep traps inside the semiconductor film on injected carriers and photogenerated carriers are well explained by the relative positions of the initial hopping levels. A better understanding of charge transport regimes in OPD helps to open new approaches for constructing high-performance OPD toward practical applications.

A Highly Conductive, Self-Recoverable, and Strong Eutectogel of a Deep Eutectic Solvent with Polymer Crystalline Domain Regulation.

It is desirable to fabricate an antifatigue gel for skin-mimicking sensors on the demand of long-term durability in practical usage. Here, we developed a physically cross-linked eutectogel based on a poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) binary polymer skeleton and a deep eutectic solvent (DES). In this eutectogel, uniformly distributed PVA crystalline domains acted as stable physical cross-linkers, and high-density hydrogen bonds possessed great reversibility. Such a polymer network structure was expected to endow this eutectogel with excellent mechanical strength, stretchability, and a self-recovery ability. Specifically, this eutectogel exhibited a superior tensile strength of 2.6 MPa, a fracture strain of 680%, and a fracture toughness of 8.39 MJ m-3. In cyclic stretching/releasing tests with a fixed strain of 100%, this eutectogel could recover its mechanical properties within a 600 s resting time. Based on this self-recoverable eutectogel, a reliable flexible sensor was fabricated, which possessed good sensitivity and stability over a wide strain range (1-300%). More importantly, the flexile sensor was able to maintain a highly repeatable response signal during 1000 consecutive stretching/releasing cycles, showing outstanding long-term durability. Given the excellent sensing performance, this eutectogel has promising potential in wearable electronics, human-machine systems, and soft robotics.

Synthesis of Highly Ion-Conductive Lignin Eutectogels in a Ternary Deep Eutectic Solvent and Nitrogen-Doped 3D Hierarchical Porous Carbons for Supercapacitors.

A new strategy has been developed to synthesize deep eutectic solvent (DES)-based lignin eutectogels by the chemical crosslinking of homogeneously dispersed lignin with poly(ethylene glycol)diglycidyl ether (PEGDE) in a ternary DES of choline chloride (ChCl)/urea/glycerol. The as-prepared lignin eutectogels have high ionic conductivity, high strength, and extreme temperature stability, which can be used as sensors for flexible electronics. N-doped hierarchical porous carbons (HPCs) are prepared when the eutectogels were solvent-replaced and sintered in the atmosphere of N2 and CO2, which results in the formation of porous carbon with a sufficient specific surface area and a three-dimensional framework composed of a hierarchical porous structure. They were used as electrodes with excellent capacitance performance attributed to the synergy of reasonable pore size distribution and excellent nitrogen doping efficiency. The electrode displayed a significantly enhanced specific capacitance (270 F g-1 at a current density of 1.0 A g-1 in a three-electrode system and 224 F g-1 at 0.5 A g-1 in a two-electrode system) and high-performance stability (7% capacitance loss over 10,000 cycles at 8 A g-1) as a supercapacitor electrode. It indicates the great promise of the lignin eutectogels for both sensing and energy storage applications.

Ultra-Stretchable, Self-Healing, Conductive, and Transparent PAA/DES Ionic Gel.

A deep eutectic solvent (DES) ionic gel is fabricated rapidly under mild conditions. The acrylic acid monomer is polymerized based on a dual self-catalytic system between Vitamin C (VC) and metal ions, such as Fe3+ in the presence of ammonium persulfate in the DES of betaine and ethylene glycol. The as-obtained PAA/DES ionic gel possesses excellent conductivity between 0.1 and 1.3 S m-1 in a wide range of temperatures from 0 to 90 °C. Moreover, it also shows an ultra-stretchable performance with stretch more than 200 times its original length even under a stretching rate of 100 mm min-1 . Besides, it can operate in harsh conditions because of its anti-freezing and anti-drying properties. The ionic gel is self-healing, and the stretching and conductive performance can be recovered after it is broken. These superior properties of the DES ionic gel provide new insights into the design of novel gels in various applications, such as tissue engineering, sensing, and wearable electronics.

Fabrication of hierarchical moth-eye structures with durable superhydrophobic property for ultra-broadband visual and mid-infrared applications.

Multifunctional antireflective coatings have practical applications as important optical components in many fields, particularly for optical devices and imaging systems. However, a good antireflection application in the visible region is often unsatisfactory for mid-infrared devices, and the difficulty in obtaining multiple capabilities simultaneously is one of the main factors limiting their applications. In this work, hierarchical moth-eye structures with superhydrophobicity were fabricated via inductively coupled plasma reactive ion etching (ICP-RIE) using nanodisk-array masks, which were formed by three-beam laser interference lithography (LIL), for improving the ultra-broadband optical properties. The uniform antireflection efficiency, which was close to 1% reflectivity covering over the visible and mid-infrared wavelength range, was exhibited by the moth-eye structures with high-quality pillar arrays. Additionally, irregular nanostructures were tailored onto the top of the pillars to generate hierarchical moth-eye structures for simultaneously obtaining both the superhydrophobic and anticorrosive properties. The fabricated antireflective structures, with the features of self-cleaning and durability, have the advantage of being for long-term use in harsh environments.

Generation of arbitrary vector vortex beams based on the dual-modulation method.

A dual-modulation method that combines a liquid crystal on silicon spatial light modulator with an S-waveplate and a biplate consisting of double quarter-wave plates (DQWPs) or double half-wave plates (DHWPs) is proposed. The method is used to realize the phase and polarization dual modulation of an incident laser beam. This study focuses on the generation of an arbitrary vector vortex beam (VVB) based on the proposed dual-modulation method. The phase and polarization transformation effects of the proposed method are theoretically derived using the Stokes-Mueller matrix algorithm. Correspondingly, an experimental configuration is constructed to generate arbitrary VVBs, and correlation analyses are carried out to quantitatively evaluate the quality of the generated VVBs. The results indicate that the correlation coefficients of the generated VVBs can reach more than 0.94 whether the biplate in the experimental configuration is DQWP or DHWP.

Design and analysis of a triple reflection grazing incidence x-ray telescope.

A triple reflection grazing incidence x-ray telescope is proposed and evaluated. This form of an optical system can detect x-ray energy that is close to the optical axis, which solves the problems encountered by traditional Wolter-type systems. In this paper, we also propose a new design method to ensure that the entire telescope structure is compact and integrated. Finally, a proof-of-concept design with an acceptable image quality is proposed.

Polarization properties of a corner-cube retroreflector with three-dimensional polarization ray-tracing calculus.

The output polarization states of corner cubes (for both uncoated and metal-coated surfaces) with an input beam of arbitrary polarization state and of arbitrary tilt angle to the cube have been analyzed by using the three-dimensional polarization ray-tracing matrix method. The diattenuation and retardance of the corner-cube retroreflector (CCR) for all six different ray paths are calculated, and the relationships to the tilt angle and the tilt orientation angle are shown. When the tilt angle is large, hollow metal-coated CCR is more appropriate than solid metal-coated CCR for the case that the polarization states of output beam should be controlled.