Coherence-controlled chaotic soliton bunch.

Controlling the coherence of chaotic soliton bunch holds the promise to explore novel light-matter interactions and manipulate dynamic events such as rogue waves. However, the coherence control of chaotic soliton bunch remains challenging, as there is a lack of dynamic equilibrium mechanism for stochastic soliton interactions. Here, we develop a strategy to effectively control the coherence of chaotic soliton bunch in a laser. We show that by introducing a lumped fourth-order-dispersion (FOD), the soliton oscillating tails can be formed and generate the potential barriers among the chaotic solitons. The repulsive force between neighboring solitons enabled by the potential barriers gives rise to an alleviation of the soliton fusion/annihilation from stochastic interactions, endowing the capability to control the coherence in chaotic soliton bunch. We envision that this result provides a promising test-bed for a variety of dynamical complexity science and brings new insights into the nonlinear behavior of chaotic laser sources.

Acid-induced pea protein gels pretreated with media milling: Gelling properties and the formation mechanism.

This study explored the effect of stirred media mill (SMM) processing on the acid-induced gelling properties of pea protein. Results showed that SMM treatment enhanced the gel strength from 75.06 g to 183.89 g and increased the water holding capacity from 46.64 % to 73.50 %. The minimum gelation concentration achieved for SMM-treated pea protein was 4 %, significantly lower than that of heat-pretreated pea protein (9 %). SMM decreased protein aggregate size from 104 µm to 180 nm. Microscopy analysis revealed that the small aggregates facilitated the formation of uniform gel networks with tight connections. Linear rheology indicated that small protein aggregates resulted in slower gelation rates with a higher G' for the formed gels. The SMM-pretreated protein gel showed strain hardening, shear thinning behaviors, and satisfactory stability to withstand large-amplitude oscillatory shear. Overall, SMM emerges as a promising technology for producing protein gel products with strong mechanical attributes and customizable rheological properties.

Sub-50†fs, 0.5†W average power Nd-doped fiber amplifier at 920†nm.

We develop an all polarization-maintaining (PM) 920 nm Nd-doped fiber amplifier delivering a train of pulses with ∼0.53 W average power and sub-50 fs duration. The sub-50 fs pulse benefits from the pre-chirping management method that allows for over 60 nm broadening spectrum without pulse breaking in the amplification stage. By virtue of the short pulse duration, the pulse peak power can reach to ∼0.31 MW in spite of the moderate average power. These results represent a key step in developing high-peak-power pulse Nd-doped fiber laser systems at 920 nm, which will find important applications in fields such as biomedical imaging, ultrafast optical spectroscopy, and excitation of quantum-dot single photon sources.

Auto-setting multi-soliton temporal spacing in a fiber laser by a hybrid GA-PSO algorithm.

Multi-soliton operation in fiber lasers is a promising platform for the investigation of soliton interaction dynamics and high repetition-rate pulse. However, owing to the complex interaction process, precisely manipulating the temporal spacing of multiple solitons in a fiber laser is still challenging. Herein, we propose an automatic way to control the temporal spacing of multi-soliton operation in an ultrafast fiber laser by a hybrid genetic algorithm-particle swarm optimization (GA-PSO) algorithm. Relying on the intelligent adjustment of the electronic polarization controller (EPC), the on-demand temporal spacing of the double solitons can be effectively achieved. In particular, the harmonic mode locking with equal temporal spacing of double solitons is also obtained. Our approach provides a promising way to explore nonlinear soliton dynamics in optical systems and optimize the performance of ultrafast fiber lasers.

Revealing the pulse dynamics in a Mamyshev oscillator: from seed signal to oscillator pulse.

The Mamyshev oscillator (MO) is a promising platform to generate high-peak-power pulse with environmentally stable operation. However, rare efforts have been dedicated to unveil the dynamics from seed signal to oscillator pulse, particularly for the multi-pulse operation. Herein, we investigate the buildup dynamics of the oscillator pulse from the seed signal in a fiber MO. It is revealed that the gain competition among the successively injected seed pulses leads to higher pump power that is required to ignite the MO, hence resulting in the higher optical gain that supports buildup of multiple oscillator pulses. The multiple oscillator pulses are identified to be evolved from the multiple seed pulses. Moreover, the dispersive Fourier transform (DFT) technique is used to reveals the real-time spectral dynamics during the starting process. As a proof-of-concept demonstration, a highly intensity-modulated pulse bunch was employed as the seed signal to reduce the gain competition effect and avoid the multi-pulse starting operation. The experimental results are verified by numerical simulations. These findings would give new insights into the pulse dynamics in MO, which will be meaningful to the communities interested in ultrafast laser technologies and nonlinear optics.

The interaction and physicochemical properties of the starch-polyphenol complex: Polymeric proanthocyanidins and maize starch with different amylose/amylopectin ratios.

This study investigated the impact of polymeric proanthocyanidins (PPC) on the physicochemical characteristics of maize starch with varying amylose content, and their potential interaction mechanism. PPC with a lower content (1 %) reduced the viscoelasticity of the high amylose maize starch (HAM) system, inhibited amylose rearrangement, and enhanced its fluidity. However, excessive PPC restrained the interaction between PPC and amylose. In contrast to HAM, PPC improved the gelation ability of waxy maize starch (WAM) as PPC concentration was raised. PPC suppressed the recrystallization of starch during storage, and PPC had a superior inhibition influence on the retrogradation of WAM in comparison to HAM. This indicated that amylopectin was more likely to interact with PPC than amylose. Hydrogen bonds were the main driving force between PPC and starch chains, which was clarified by Fourier transform-infrared, nuclear magnetic resonance, X-ray diffraction, iodine bonding reaction, and dynamic light scattering data. Additionally, the mechanism of interaction between PPC and the two starch components may be similar, and variance in physicochemical attributes can be primarily credited to the percentage of amylose to amylopectin in starch.

Gastrointestinal microbiome, resistance genes, and risk assessment of heavy metals in wild giant pandas.

The gastrointestinal microbiome (GM) of giant panda (GP) plays an important role in food utilization and health and is also an essential reservoir of resistance genes. Currently, little knowledge is available on the GM, acid resistance genes (AcRGs), antibiotic resistance genes (ARGs), metal resistance genes (MRGs), and mobile genetic elements (MGEs) in wild GPs. We sampled the gastrointestinal tract of a dead GP and explored the composition and function of GM and resistance genes through cryo-scanning electron microscopy, metagenomic sequencing, and genome-resolved metagenomics. The concentration of metals in the gastrointestinal lumen, feces, bamboo, and soil was measured by inductively coupled plasma mass spectrometry. Results showed that the composition of the microbiota varied in different gastrointestinal regions. Fecal microbiota was highly associated with small intestinal and colonic microbes. The lignocellulosic cross-linked structure of bamboo was destroyed in the stomach initially and destroying degree increased from stomach to anus. Reconstruction of metagenome-assembled-genomes confirmed that core GM, e.g., Streptococcus, Clostridium, Lactococcus, Leuconostoc, and Enterococcus, carried genes encoding the lignocellulose degradation enzyme. There were no significant differences of resistance genes between gastrointestinal and fecal samples, except MGEs. Multidrug and multi-metal resistance genes were predominant in all samples, while the transposase gene tnpA was the major type of MGE. Significant correlations were observed among the abundance of GM, resistance genes, and MGEs. Gastrointestinal and fecal mercury and chromium were the main metals influencing GM and resistance genes. The content of gastrointestinal and fecal metals was significantly associated with the presence of the same metals in bamboo, which could pose a threat to the health of wild GPs. This study characterized the gastrointestinal microbiome of wild GPs, providing new evidence for the role of the gastrointestinal microbiome in degrading lignocellulose from bamboo and highlighting the urgent need to monitor metal levels in soil and bamboo.

A novel whole peanut butter refined by stirred media mill: The size, microstructure, rheology, nutrients, and flavor.

A novel whole peanut butter (PB) was developed using an emerging technology called stirred media mill (SMM). The impact of SMM on the size, microstructure, rheology, nutrient, and flavor of PB was investigated. The SMM treatment significantly decreased the particle size of PB, damaged cell structure, and released the oil body from cells. The apparent viscosity of PB decreased with the grinding process. Visual inspection revealed that the colloidal stability of PB was improved. The fatty acid composition was not affected by the grinding process. However, the tocopherol contents of the extracted oil slightly increased. Electronic nose and GC-MS analysis indicated that SMM could alter the flavor of PB after grinding for 45 min. Overall, SMM was a potential process technology to manufacture stable nut butter with smooth texture and delightful flavor profile.

Optical focusing inside scattering media with iterative time-reversed ultrasonically encoded near-infrared light.

Focusing light inside scattering media is a long-sought goal in optics. Time-reversed ultrasonically encoded (TRUE) focusing, which combines the advantages of biological transparency of the ultrasound and the high efficiency of digital optical phase conjugation (DOPC) based wavefront shaping, has been proposed to tackle this problem. By invoking repeated acousto-optic interactions, iterative TRUE (iTRUE) focusing can further break the resolution barrier imposed by the acoustic diffraction limit, showing great potential for deep-tissue biomedical applications. However, stringent requirements on system alignment prohibit the practical use of iTRUE focusing, especially for biomedical applications at the near-infrared spectral window. In this work, we fill this blank by developing an alignment protocol that is suitable for iTRUE focusing with a near-infrared light source. This protocol mainly contains three steps, including rough alignment with manual adjustment, fine-tuning with a high-precision motorized stage, and digital compensation through Zernike polynomials. Using this protocol, an optical focus with a peak-to-background ratio (PBR) of up to 70% of the theoretical value can be achieved. By using a 5-MHz ultrasonic transducer, we demonstrated the first iTRUE focusing using near-infrared light at 1053 nm, enabling the formation of an optical focus inside a scattering medium composed of stacked scattering films and a mirror. Quantitatively, the size of the focus decreased from roughly 1 mm to 160 µm within a few consecutive iterations and a PBR up to 70 was finally achieved. We anticipate that the capability of focusing near-infrared light inside scattering media, along with the reported alignment protocol, can be beneficial to a variety of applications in biomedical optics.

Investigation of bovine ß-lactoglobulin-procyanidin complexes interactions and its utilization in O/W emulsion.

Procyanidins are bioactive polyphenols that have a strong affinity to proteins. Beta-lactoglobulin (BLG) is widely used as an emulsifier in the food and other industries. This study evaluated the interaction between BLG and A-type procyanidin dimer (PA2) using the spectroscopic, thermodynamic, and molecular simulation. PA2 decreased the transmissivity and quenched the intrinsic fluorescence of BLG, suggesting that the two molecules formed a complex. The binding of PA2 reduced the surface hydrophobicity and altered the conformation of BLG with increasing the random coil regions. Thermodynamic and isothermal titration calorimetry analyses suggested that the main driving force of PA2-BLG interaction was hydrophobic attraction. Molecular docking simulations were used to identify the main interaction sites and forces in the BLG-PA2 complexes, which again indicated that hydrophobic interactions dominated. In addition, the influence of PA2 on the ability of BLG to form and stabilize O/W emulsions was analyzed. Emulsions formulated using BLG-PA2 complexes contained relatively small droplets (D4,3 ≈ 0.7 µm) and high surface potentials (absolute value >50 mV). Compared to BLG alone, BLG-PA2 complexes improved the storage stability of the emulsions. This study provides valuable new insights into the formation, properties, and application of protein-polyphenol complexes as functional ingredients in foods.

Factors influencing bamboo intake of captive giant pandas (Ailuropoda melanoleuca).

Bamboo is the main food source of the giant panda. To increase bamboo intake in captive giant pandas, we studied factors affecting the bamboo intake. Fourteen healthy captive giant pandas in Dujiangyan Base of China Conservation and Research Center for The Giant Panda ("Dujiangyan Base" for short) were selected as research objects. A bamboo feeding experiment was conducted to study the effects of seasons, bamboo age, slope orientations where bamboo grows and felling-feeding time on bamboo intake of the giant panda. We found that the type of bamboo that captive giant pandas feed on was abundant in spring and summer, but relatively homogeneous in winter. With the increase of bamboo age, the intake of bamboo leaves decreased, while bamboo culms increased. The feed intake of 1-year-old bamboo leaves and 5-year-old bamboo culms reached the highest respectively. The slope orientation also affected the panda's bamboo intake, and the bamboo growing on sunny slopes or semi-sunny slopes was more favored by captive giant pandas. Moreover, the bamboo intake reached the highest when felling-feeding time was less than 24 h. In short, we confirmed that seasons, bamboo age, slope orientations and felling-feeding time were factors affecting bamboo intake for captive giant pandas. This study was expected to provide scientific guidance improving the feeding behavior management of captive giant pandas.

Periodic transition between two evolving soliton pulsation states in an Yb-doped fiber laser.

Due to the fascinating features, pulsating solitons attract much attention in the field of nonlinear soliton dynamics and ultrafast lasers. So far, most of the investigations on pulsating soliton are conducted in Er-doped fiber lasers. In this work, we reported the periodic transition between two evolving pulsating soliton states in an Yb-doped fiber laser. By using the real-time measurement techniques, the spectral and temporal characteristics of this transition state were investigated. Two evolving soliton pulsation states have similar evolution process, i.e., from pulsating towards quasi-stable mode-locked states. However, the details of the two processes are different, such as the pulse energy levels, pulsating modulation depths, duration of quasi-stable mode-locked states. The transition between two evolving soliton pulsation states could be attributed to the interaction of the polarizer and the varying polarization states of the pulse inside the laser cavity. The experimental results will contribute to the further understanding of soliton pulsating dynamics in dissipative optical systems.

Assisting the mode-locking of a figure-9 fiber laser by thermal nonlinearity of graphene-decorated microfiber.

The self-starting performance of a figure-9 fiber laser is critically dependent on the phase shift difference between the counter-propagating beams. Herein, we propose an effective approach to dynamically control the phase shift difference in a figure-9 fiber laser by utilizing the thermal nonlinearity of graphene-decorated microfiber device. With the adjustment of the control laser power injected into the graphene-decorated microfiber, the self-starting mode-locked threshold of the figure-9 fiber laser can be attained in a flexible pump power range, i.e., from 300 mW to 390 mW. These findings demonstrated that the graphene-decorated microfiber could act as a dynamical control device of phase shift difference for improving the performance of figure-9 fiber lasers, and might also open up new possibilities for applications of microfiber photonic devices in the field of ultrafast optics.

Noncovalent interaction mechanism and functional properties of flavonoid glycoside-ß-lactoglobulin complexes.

The interaction of flavonoid glycosides with milk protein and effects on the functional properties of flavonoid glycoside-ß-lactoglobulin complexes are still inexplicit. The noncovalent interactions between flavonoid glycosides including quercetin (QE), quercitrin (QI), and rutin (RU) with ß-lactoglobulin (ß-LG) were determined by computer molecular docking and multispectral technique analysis. The fluorescence quenching results indicated that the flavonoid glycosides formed stable complexes with ß-LG by the static quenching mechanism. The computer molecular docking and thermodynamic parameters analysis conclude that the main interaction of ß-LG-QE was via hydrogen bonding, while for ß-LG-QI and ß-LG-RU it is via hydrophobic forces. The order of binding affinity to ß-LG was QE (37.76 × 104 L mol-1) > RU (16.80 × 104 L mol-1) > QI (11.17 × 104 L mol-1), which indicated that glycosylation adversely affected the colloidal complex binding capacity. In this study, the physicochemical properties of the protein-flavonoid colloidal complex were determined. The analysis by circular dichroism spectroscopy demonstrated that flavonoid glycosides made the protein structure looser by inducing the secondary structure of ß-LG to transform from the α-helix and ß-sheet to random coils. The hydrophobicity of ß-LG decreased due to binding with flavonoid glycosides, while functional properties including foaming, emulsification, and antioxidant capacities of ß-LG were improved due to the noncovalent interactions. This study presents a part of the insight and guidance on the interactive mechanism of flavonoid glycosides and proteins and is helpful for developing functional protein-based foods.

A review: strategies to reduce infection in tantalum and its derivative applied to implants.

Implant-associated infection is the main reasons for implant failure. Titanium and titanium alloy are currently the most widely used implant materials. However, they have limited antibacterial performance. Therefore, enhancing the antibacterial ability of implants by surface modification technology has become a trend of research. Tantalum is a potential implant coating material with good biological properties. With the development of surface modification technology, tantalum coating becomes more functional through improvement. In addition to improving osseointegration, its antibacterial performance has also become the focus of attention. In this review, we provide an overview of the latest strategies to improve tantalum antibacterial properties. We demonstrate the potential of the clinical application of tantalum in reducing implant infections by stressing its advantageous properties.

Structure characteristics and physicochemical property of starch, dietary fiber, protein in purple corn flour modified by low temperature impact mill.

The structural changes of macromolecules (starch, dietary fiber and protein) in purple corn flour (PCF) modified by a low temperature impact mill (LTIM) at different air classifier speed (ACS) were investigated. LTIM changed the multi-scale structure of starch, which was characterized by increased starch damage, stronger destruction of relative crystallinity (from 37.85 % to 15.53 %) and short-range ordered structure (R1047/1022, from 1.21 to 0.73) with the increased ACS. The structure of dietary fiber was also destroyed on multi-level, including decreased particle size, destructive morphology, and slightly changed crystalline structure. Additionally, LTIM showed high damage on the senior structure (surface hydrophobicity, disulfide bond, secondary structure) of protein. Due to the structure changes modified by LTIM, starch, dietary fiber and protein played different role on hydration property of PCF. Starch had positive effect, while dietary fiber and protein had negative effect. Our experimental results may provide valuable information for further analysis of other quality changes (oil holding capacity, cation exchange capacity, ability to produce high-quality dough or end-out products, etc.) of purple corn flour after LTIM treatment.

IFITM3 promotes NiV envelope protein-mediated entry into MDCK cells and interacts with the fusion subunit of the F protein.

IFITM proteins are a host restriction factor with broad-spectrum antiviral activity, but the role in the paramyxovirus entry remains unclear. Nipah virus (NiV) is a zoonotic virus of the paramyxoviridae with extremely high lethality. Here, we assessed the role of IFITM3 on NiV G and F glycoprotein-mediated virus entry. Using NiV pseudovirus bearing NiV G and F proteins to infect IFITM3-induced MDCK cells, we found that overexpression of IFITM3 promotes NiV G and F proteins-mediated virus entry. Mechanistically, the subcellular distribution showed that F protein completely co-localized with IFITM3, but G protein does not. Immunoprecipitation further indicated that IFITM3 strongly captures F protein rather than G protein. F protein truncation found that the F1 subunit completely co-localized and captures with IFITM3, but not the F2 subunit. Furthermore, IFITM3 strongly binds to F1 truncations containing fusion peptide (FP), and F1 strongly captures IFITM3 truncation with the intramembrane domain (IMD). Together, the results suggest that IFITM3 can promote NiV G and F proteins-mediated virus entry into MDCK cells, and IFITM3 directly interacts with the F1 subunit of NiV F protein dependent on the former's IMD and the latter's FP, which may occur after incorporation of fusion peptides into the cell membrane following virus fusion activation.

Exploring the pharmacological action mechanism of Ligusticum Chuanxiong-Piper Longum couplet medicines on the treatment of migraine based on network pharmacology.

Objective: To study the mechanisms of the Ligusticum chuanxiong Hort.-Piper longum L. herbal pair (LPHP) in the treatment of migraine using network pharmacology. Methods: The active constituents of LPHP and their targets were searched for and screened using the Chinese Medicine System Pharmacology Database. Genes related to migraine were searched on GeneCards, Online Mendelian Inheritance in Man and other databases. Cytoscape was used to construct and combine active component-target and disease-target networks. The core target was screened by network topology analysis, and the Metascape database was used for gene ontology analysis of key targets and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis to explore the molecular mechanisms in the treatment of migraine. Results: A total of 28 active constituents of LPHP were obtained through database screening and literature review, and 60 cross-linking targets were obtained. The target sites were analysed using a protein-protein interaction network to obtain six target proteins with a greater degree of relevance. These were identified as the main targets for the treatment of hypertension, and these key targets were found to be associated with 20 signalling pathways, including neuroactive ligand-receptor interaction, the calcium signalling pathway, the cGMP-PKG signalling pathway, pathways in cancer and the cyclic adenosine 3',5'-cyclic monophosphate (cAMP) signalling pathway. Conclusion: This study reveals the molecular mechanism of LPHP in the treatment of migraine from the perspective of network pharmacology and provides a basis for further research and molecular mechanism research.

1.7 µm figure-9 Tm-doped ultrafast fiber laser.

The evolution of multiphoton microscopy is critically dependent on the development of ultrafast laser technologies. The ultrashort pulse laser source at 1.7 µm waveband is attractive for in-depth three-photon imaging owing to the reduced scattering and absorption effects in biological tissues. Herein, we report on a 1.7 µm passively mode-locked figure-9 Tm-doped fiber laser. The nonreciprocal phase shifter that consists of two quarter-wave plates and a Faraday rotator introduces phase bias between the counter-propagating beams in the nonlinear amplifying loop mirror. The cavity dispersion is compensated to be slightly positive, enabling the proposed 1.7 µm ultrafast fiber laser to deliver the dissipative soliton with a 3-dB bandwidth of 20 nm. Moreover, the mode-locked spectral bandwidth could be flexibly tuned with different phase biases by rotating the wave plates. The demonstration of figure-9 Tm-doped ultrafast fiber laser would pave the way to develop the robust 1.7 µm ultrashort pulse laser sources, which could find important application for three-photon deep-tissue imaging.

Effects of Moderate Enzymatic Hydrolysis on Structure and Functional Properties of Pea Protein.

Pea protein (PP) was moderately hydrolyzed using four proteolytic enzymes including flavourzyme, neutrase, alcalase, and trypsin to investigate the influence of the degree of hydrolysis (DH) with 2%, 4%, 6%, and 8% on the structural and functional properties of PP. Enzymatic modification treatment distinctly boosted the solubility of PP. The solubility of PP treated by trypsin was increased from 10.23% to 58.14% at the 8% DH. The results of SDS-PAGE indicated the protease broke disulfide bonds, degraded protein into small molecular peptides, and transformed insoluble protein into soluble fractions with the increased DH. After enzymatic treatment, a bathochromic shift and increased intrinsic fluorescence were observed for PP. Furthermore, the total sulfhydryl group contents and surface hydrophobicity were reduced, suggesting that the unfolding of PP occurred. Meanwhile, the foaming and emulsification of PP were improved after enzymatic treatment, and the most remarkable effect was observed under 6% DH. Moreover, under the same DH, the influence on the structure and functional properties of PP from large to small are trypsin, alcalase, neutrase and flavourzyme. This result will facilitate the formulation and production of natural plant-protein-based products using PP.