Interfacial Behavior and Long-Term Stability of the Emulsions Stabilized by Sugar Beet Pectin-Ca2+ Complexes with Different Cross-Linking Degrees.

Recent studies showed that sugar beet pectin exhibited more excellent emulsifying properties than traditional citrus peel pectin and apple pectin ascribed to the higher content of neutral sugar, protein, ferulic acid, and acetyl groups. It is precisely because of the extremely complex molecular structure of pectin that the emulsifying properties of the pectin-Ca2+ complex are still unclear. In this study, SBP-Ca2+ complexes with different cross-linking degrees were prepared. Subsequently, their interfacial adsorption kinetics, the resistance of interfacial films to external perturbances, and the long-term stability of the emulsions formed by these SBP-Ca2+ complexes were measured. The results indicated that the highly cross-linked SBP-Ca2+ complex exhibited slower interfacial adsorption kinetics than SBP alone. Moreover, compared with SBP alone, the oil-water interfacial film loaded by the highly cross-linked SBP-Ca2+ complex exhibited a lower elasticity and a poorer resistance to external perturbances. This resulted in a larger droplet size, a lower ζ-potential value, a larger continuous viscosity, and a worse long-term stability of the emulsion formed by the highly cross-linked SBP-Ca2+ complex. This study has very important guiding significance for deeply understanding the emulsification mechanism of the pectin-Ca2+ complex.

Ultrasonic effects on the degradation kinetics, structural characteristics and protective effects on hepatocyte lipotoxicity induced by palmitic acid of Pueraria Lobata polysaccharides.

In this study, a high-molecular-weight Pueraria lobata polysaccharide (PLP) with a molecular weight of 273.54 kDa was degraded by ultrasound, and the ultrasonic degradation kinetics, structural characteristics and hepatoprotective activity of ultrasonic degraded PLP fractions (PLPs) were evaluated. The results showed that the ultrasonic treatment significantly reduced the Mw and particle size of PLP, and the kinetic equation of ultrasonic degradation of PLP followed to the midpoint fracture model (the fist-order model). The monosaccharide composition analysis, FT-IR, triple helix structure and XRD analysis all indicated that the ultrasound degradation did not destroy the primary structure of PLP, but the thermal stability of degraded fractions improved. Additionally, the scanning electron microscopy analysis demonstrated that the surface morphology of PLP was altered from smooth, flat, compact large flaky structure to a sparse rod-like structure with sparse crosslinking (PLP-7). The degraded PLP fractions (0.5 mg/mL) with lower Mw exhibited better antioxidant activities and protective effects against palmitic acid-induced hepatic lipotoxicity, which may be due to the increased exposure of active groups such as hydroxyl groups of PLP after ultrasound. Further investigation showed that PLPs not only increased Nrf2 phosphorylation and its nuclear translocation, thereby activating Nrf2/Keap1 signaling pathway, but also enhanced HO-1, NQO-1, γ-GCL gene expressions and promoted superoxide dismutase and catalase activities, which protected hepatocytes against PA-induced oxidative stress and lipotoxicity. Overall, our research might provide an in-depth insight into P. Lobata polysaccharide in ameliorating lipid metabolic disorders, and the results revealed that ultrasonic irradiation could be a promising degradation method to produce value-added polysaccharide for use in functional food.

Ti3C2Tx/MXene Composite Aerogel Flexible Biosensor for Measuring Occlusal Force In Situ.

Occlusal force is an important parameter for evaluating the function of the occlusal system. Traditional occlusal forces can only be measured qualitatively. Here, we report a flexible piezoresistive pressure sensor with high sensitivity and a wide measurement range for in situ occlusal force measurements through the articulating paper. The sensing layer of the flexible piezoresistive sensor is a 3D porous MXene composite aerogel, which is fabricated by vacuum freezing. The MXene piezoresistive sensor is composed of the interdigital electrodes, the sensing layer, the PI encapsulation layer, and an articulating paper encapsulation layer. The sensor shows perfect performance with high sensitivity (210.21 kPa-1), wide measurement range (∼420 kPa), and a fast response time (123 ms response time, 163 ms recovery time). The amplitude of the occlusal force, which varied with time, can be observed on the mobile phone through the wireless system with the Bluetooth module. This technique has broad application prospects in oral health. In this work, we propose a simple method and a new idea for manufacturing high-performance wearable bioelectronic sensors.

A critical review of RG-I pectin: sources, extraction methods, structure, and applications.

In recent years, RG-I pectin isolated by low-temperature alkaline extraction methods has attracted the attention of a large number of researchers due to its huge health benefits. However, studies on other applications of RG-I pectin are still lacking. In this study, we summarized the sources (e.g. potato pulp, sugar beet pulp, okra, apple pomace, citrus peel, pumpkin, grapefruit, ginseng, etc.), extraction methods, fine structure and applications of RG-I pectin in physiological activities (e.g. anti-cancer, anti-inflammatory, anti-obesity, anti-oxidation, immune regulation, prebiotics, etc.), emulsions, gels, etc. These neutral sugar side chains not only endow RG-I pectin with various physiological activities but the entanglement and cross-linking of these side chains also endow RG-I pectin with excellent emulsifying and gelling properties. We believe that this review can not only provide a comprehensive reading for new workers interested in RG-I pectin, but also provide a valuable reference for future research directions of RG-I pectin.

Effects of glycation with chitooligosaccharide on digestion and fermentation processes of lactoferrin in vitro.

This study aimed to investigate the digestion and fermentation processes of lactoferrin (LF) glycated with chitooligosaccharide (COS) under a controlled Maillard reaction, utilizing the in vitro digestion and fermentation model, and to compare the results of these processes to LF undertaken without glycation. After gastrointestinal digestion, the products of the LF-COS conjugate were found to have more fragments with lower molecular weight than LF, and the antioxidant capabilities (via ABTS and ORAC assay) of the LF-COS conjugate digesta also increased. In addition, the undigested fractions could be further fermented by the intestinal microbiota. Compared with LF, more short-chain fatty acids (SCFAs) were generated (from 2397.40 to 2623.10 µg/g), and more species of microbiota (from 451.78 to 568.10) were observed in LF-COS conjugate treatment. Furthermore, the relative abundance of Bacteroides and Faecalibacterium that could utilize carbohydrates and metabolic intermediates to produce SCFAs also increased in LF-COS conjugate than that of LF. Our results demonstrated that glycation with COS under the controlled wet-heat treatment Maillard reaction could modify the digestion of LF and have a potentially positive influence on the intestinal microbiota community.

Multiscale combined techniques for evaluating emulsion stability: A critical review.

Emulsions are multiscale and thermodynamically unstable systems which will undergo various unstable processes over time. The behavior of emulsifier molecules at the oil-water interface and the properties of the interfacial film are very important to the stability of the emulsion. In this paper, we mainly discussed the instability phenomena and mechanisms of emulsions, the effects of interfacial films on the long-term stability of emulsions and summarized a set of systematic multiscale combined methods for studying emulsion stability, including droplet size and distribution, zeta-potential, the continuous phase viscosity, adsorption mass and thickness of the interfacial film, interfacial dilatational rheology, interfacial shear rheology, particle tracking microrheology, visualization technologies of the interfacial film, molecular dynamics simulation and the quantitative evaluation methods of emulsion stability. This review provides the latest research progress and a set of systematic multiscale combined techniques and methods for researchers who are committed to the study of oil-water interface and emulsion stability. In addition, this review has important guiding significances for designing and customizing interfacial films with different properties, so as to obtain emulsion-based delivery systems with varying stability, oil digestibility and bioactive substance utilization.

Flexible Pressure Sensors with Combined Spraying and Self-Diffusion of Carbon Nanotubes.

High-performance wearable sensors are required for applications in medical health and human-machine interaction, but their application has limited owing to the trade-off between sensitivity, pressure range, and durability. Herein, we propose the combined spraying and self-diffusion process of carbon nanotubes (CNTs) to balance and improve these parameters with the CNTs spontaneously diffusing into the film surface before the film curing. The obtained sensor not only achieves high sensitivity (155.54 kPa-1) and ultrawide pressure detection range (0.1-500 kPa) but also exhibits exceptional durability (over 12,000 pressure cycles at a high pressure of 300 kPa). In addition, the sensor exhibits a fast response (25 ms), good stability, and full flexibility. This process is a general approach that may improve the performance of various types of thin film piezoresistive sensors. Besides, the fabricated sensors can be flexibly scaled into sensor arrays and communicate with smart devices to achieve wireless smart monitoring. At present, the sensor shows broad application prospects in the fields of intelligent medical health and motion sensing.

Effect of chitosan oligosaccharide glycosylation on the emulsifying property of lactoferrin.

There is fast increasing interest in the development of alimentary protein stabilized emulsions due to their potential applications in functional food fields. This work studied the effect of glycation degree with chitosan oligosaccharide (COS) on the emulsifying properties of lactoferrin (LF) through Maillard reaction. In the present study, SDS-PAGE and FT-IR were used to confirm LF and COS covalently binding together successfully. Intrinsic fluorescence showed that glycation with COS led more hydrophobic groups exposed to the surface of the structure and particle size increase of LF. Emulsions with 50% (v/v) oil phase and protein concentration of 2% (w/v) was fabricated through one-step shear method. Compared with native LF, emulsions stabilized by LF-COS conjugates showed smaller droplet size and lower creaming index (CI). Among these samples, LF-COS conjugates under 4 h had the best emulsifying efficiency and stability, the emulsion droplet size and the CI of which decreased 39.66% and 28.55% compared with LF, respectively. Furthermore, glycation with COS enhanced the interfacial activity of LF leading to more adsorbing amount and forming thicker layer on the droplets and gel network in the emulsions. This finding would make sense to further understand the modification of emulsifying properties of alimentary proteins through glycosylation with saccharides and develop novel protein-based emulsifiers.

Glycation mechanism of lactoferrin-chitosan oligosaccharide conjugates with improved antioxidant activity revealed by high-resolution mass spectroscopy.

Glycosylation has a great effect on the antioxidant ability of proteins, which is due to the structural conformational change of peptides in the protein. In this study, a chitosan oligosaccharide (COS) was selected as the saccharide for glycation with lactoferrin (LF) by a wet-heat method, and a new stripe at a higher molecular zone in the gel of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and a change in the bond revealed by Fourier transform infrared (FT-IR) and fluorescence spectroscopy analyses were used to confirm that the chitosan oligosaccharide was successfully covalently bound to lactoferrin. The ABTS and oxygen radical absorbance capacity (ORAC) assays indicated that lactoferrin exhibited a stronger antioxidant activity after glycation with the chitosan oligosaccharide. High-resolution mass spectroscopy further illuminated the relationship of enhanced antioxidant capacity and structural conformational change of peptides in lactoferrin at a molecular level.

Crystal Size Effect on Carrier Transport of Microscale Perovskite Junctions via Soft Contact.

To reduce the size of optoelectronic devices, it is essential to understand the crystal size effect on the carrier transport through microscale materials. Here, we show a soft contact method to probe the properties of irregularly shaped microscale perovskite crystals by employing a movable liquid metal electrode to form a self-adaptative deformable electrode-perovskite-electrode junction. Accordingly, we demonstrate that (1) the photocurrents of perovskite quantum dot films and microplatelets show profound differences regarding both the on/off ratio and the response time upon light illumination; and (2) small-size perovskite (<50 µm) junctions may show negative differential resistance (NDR) behavior, whereas the NDR phenomenon is absent in large-size perovskite junctions within the same bias regime. Our studies provide a method for studying arbitrary-shaped crystals without mechanical damage, assisting the understanding of the photogenerated carriers transport through microscale crystals.

Physicochemical properties and bioactivity of whey protein isolate-inulin conjugates obtained by Maillard reaction.

The functional properties and physiological functions of whey protein isolate (WPI) decreased near its isoelectric point (PI). The Maillard reaction covalently binding polysaccharides to proteins is an effective method to improve the functional activities of proteins. WPI-inulin conjugates were prepared by wet-heating method at 70 °C for 2 h, 4 h and 6 h, respectively. New bonds at higher molecular zone appearing at SDS-PAGE, decreased free amino acid content and new formed CN bonds in FT-IR of conjugates compared with WPI confirmed the formation of the covalent bonds between WPI and inulin. As the increase of the reaction time, both the brown intensity and fluorescence intensity of WPI-inulin conjugates became higher. Amino acid contents, Circular dichroism analysis and SEM analysis presented the primary structure, secondary structure and surface structure change of protein after covalent with inulin. Emulsion properties of emulsion activity (EAI) and emulsion stability (ES) of WPI-inulin conjugates were assessed and both showed significantly enhanced compared with WPI at range of pH 3 to pH 7. AAPH+ scavenging test and ORAC measurement also revealed that covalent binding with inulin enhanced the antioxidant activities of WPI. This work presented the conjugation with inulin successfully enhanced the functional properties of WPI.

A recycled environmental friendly flame retardant by modifying para-aramid fiber with phosphorus acid for thermoplastic polyurethane elastomer.

The application of fibers is more and more extensive, and the pollution caused by abandoned fibers is getting more serious, which has aroused wide attention. So it is necessary to find a way to solve the problem. In this paper, the para-aramid fiber (AF) was recycled and modified by phosphoric acid, and then was applied as environmental friendly flame retardant for thermoplastic polyurethane elastomer (TPU). The flame retardant properties of TPU were tested using cone calorimeter test (CCT) and thermogravimetric/Fourier transform infrared spectroscopy (TG-IR). The CCT test showed that AF-P had better flame retardant effect on TPU than pure AF. Remarkably, the pHRR value for the sample with 1.00wt% content of AF-P was decreased by 48.1%; AF-P had improved the char forming progress and the residual mass was 30.6%, which was much more than pure TPU. TG test showed that AF-P could improve the thermal stability of TPU at high temperature. The TG-IR test revealed that AF-P had reduced the release of CO2 at the beginning. Based on the above results, it will make a great influence on the study of reuse of fibers and environmental friendly flame retardant of polymer.

Fire safety improvement of para-aramid fiber in thermoplastic polyurethane elastomer.

This article mainly studied fire safety effects of para-aramid fiber (AF) in thermoplastic polyurethane (TPU). The TPU/AF composites were prepared by molten blending method, and then the fire safety effects of all TPU composites were tested using cone calorimeter test (CCT), microscale combustion colorimeter test (MCC), smoke density test (SDT), and thermogravimetric/fourier transform infrared spectroscopy (TG-IR). The CCT test showed that AF could improve the fire safety of TPU. Remarkably, the peak value of heat release rate (pHRR) and the peak value of smoke production rate (pSPR) for the sample with 1.0wt% content of AF were decreased by 52.0% and 40.5% compared with pure TPU, respectively. The MCC test showed that the HRR value of AF-2 decreased by 27.6% compared with pure TPU. TG test showed that AF promoted the char formation in the degradation process of TPU; as a result the residual carbon was increased. The TG-IR test revealed that AF had increased the thermal stability of TPU at the beginning and reduced the release of CO2 with the decomposition going on. Through the analysis of the results of this experiment, it will make a great influence on the study of the para-aramid fiber in the aspect of fire safety of polymer.

Copper-mediated ortho C-H sulfonylation of benzoic acid derivatives with sodium sulfinates.

Copper-mediated direct ortho C-H bond sulfonylation of benzoic acid derivatives with sodium sulfinates was achieved by employing an 8-aminoquinoline moiety as the bidentate directing group. Various aryl sulfones were synthesized in good yields with excellent regioselectivity.

Association of TNF-α promoter polymorphisms with the outcome of persistent HBV infection in a northeast Chinese Han population.

Tumor necrosis factor-α (TNF-α) plays an important role in the pathogenesis and clinical outcome of chronic hepatitis B virus (HBV) infection. The objective of this study was to evaluate the relationship between functional polymorphisms of TNF-α and different outcomes of persistent HBV infection in a northeast Chinese Han population. Here 189 HBV spontaneously recovered subjects (SR), 571 HBV-infected patients including 180 chronic hepatitis B (CHB), 196 liver cirrhosis (LC), and 195 hepatocellular carcinoma (HCC) individuals were enrolled in this study. All the samples were genotyped for TNF-α -857C/T and -863C/A using the polymerase chain reaction-restriction fragment length polymorphism method. The frequency of -857CC genotype was significantly higher in CHB and LC individuals compared with that of SR subjects (P= 0.03, OR = 1.57, 95% CI 1.04-2.39 and P= 0.03, OR = 1.57, 95% CI 1.04-2.35, respectively). A significant difference in the distribution of the allele -857C was observed for both CHB vs. SR (P= 0.01, OR = 1.52, 95% CI 1.08-2.13) and LC vs. SR (P= 0.02, OR = 1.47, 95% CI 1.06-2.04) cohorts. In addition, the frequency of -863AA genotype was significantly higher in CHB and LC patients than that of SR subjects (P= 0.01, OR = 3.90, 95% CI 1.35-11.23 and P= 0.01, OR = 3.83, 95% CI 1.34-10.96, respectively), and allele -863A frequency was significantly more common in CHB, LC, and HCC cohorts than that of SR controls (P= 0.004, OR = 1.72, 95% CI 1.19-2.50; P= 0.001, OR = 1.81, 95% CI 1.26-2.61 and P= 0.001, OR = 1.90, 95% CI 1.33-2.73, respectively). Our data also revealed that haplotype CA was strongly associated with persistent HBV infection. These results suggest an association between the TNF-α promoter variants and different outcomes of persistent HBV infection in the studied population.

Clinical significance of a myeloperoxidase gene polymorphism and inducible nitric oxide synthase expression in cirrhotic patients with hepatopulmonary syndrome.

The clinical significance of a myeloperoxidase (MPO) gene polymorphism and inducible nitric oxide synthase (iNOS) expression in cirrhotic patients with hepatopulmonary syndrome (HPS) was explored. Enrolled subjects were divided into three groups according to their disease/health conditions: the HPS group (cirrhotic patients with HPS; n=63), the non-HPS group (cirrhotic patients without HPS; n=182), and the control group (healthy subjects without liver disease; n=35). The distribution of the MPO -463 G/A genotype and its relationship with iNOS expression in a typical cell block from ascitic fluid were detected by immunohistochemistry and polymerase chain reaction-restricted fragment length polymorphism analysis (PCR-RFLP). In the HPS group, the partial pressure of oxygen in blood and ascitic fluid was significantly decreased (8.95+/-1.58 kPa and 6.81+/-0.95 kPa, respectively; both P<0.01), while the partial pressure of carbon dioxide significantly increased (4.62+/-0.20 kPa and 5.92+/-0.45 kPa, respectively; P<0.01). MPO and iNOS levels were significantly increased in the HPS group as compared with the non-HPS group. These increases were even more remarkable in ascitic fluid (41.36+/-11.62 and 13.23+/-4.81 microg/L; 10.27+/- 3.20 and 4.95+/-1.12 microg/L) than in blood (16.66+/-5.24 and 4.87+/-1.73 microg/L; 5.79+/-2.31 and 2.35+/-0.84 microg/L). The distribution of the MPO genotypes GG, GA, and AA were 76.2%, 22.2% and 1.6% in the HPS group, and 57.7%, 37.9% and 4.4% in the non-HPS group (P<0.05). The expression of iNOS was significantly higher in patients with the G alleles (G/G and G/A) (61.54%, 48/78) than in patients with A alleles (G/A and A/A) (38.46%, 30/78) (P<0.01). It was suggested that the expression levels of iNOS and MPO were correlated with HPS-induced hypoxemia. The MPO-463 G/A mutation might be a protective factor that prevents the development of HPS. The MPO might be involved in the regulation of iNOS expression. In humans, MPO pathways, the iNOS/NO system, and their interaction might have an impact on the occurrence and development of HPS.