RESUMO
Developing "turn on" fluorescent probes was desirable for the detection of the effective anticoagulant agent heparin in clinical applications. Through combining the aggregation induced emission (AIE) fluorogen tetraphenylethene (TPE) and heparin specific binding peptide AG73, the promising "turn on" fluorescent probe TPE-1 has been developed. Nevertheless, although TPE-1 could achieve the sensitive and selective detection of heparin, the low proteolytic stability and undesirable poor solubility may limit its widespread applications. In this study, seven TPE-1 derived fluorescent probes were rationally designed, efficiently synthesized and evaluated. The stability and water solubility were systematically estimated. Especially, to achieve real-time monitoring of proteolytic stability, the novel Abz/Dnp-based "turn on" probes that employ the internally quenched fluorescent (IQF) mechanism were designed and synthesized. Moreover, the detection ability of synthetic fluorescent probes for heparin were systematically evaluated. Importantly, the performance of d-type peptide fluorescent probe XH-6 indicated that d-type amino acid substitutions could significantly improve the proteolytic stability without compromising its ability of heparin sensing, and attaching solubilizing tag 2-(2-aminoethoxy) ethoxy) acid (AEEA) could greatly enhance the solubility. Collectively, this study not only established practical strategies to improve both the water solubility and proteolytic stability of "turn on" fluorescent probes for heparin sensing, but also provided valuable references for the subsequent development of enzymatic hydrolysis-resistant d-type peptides based fluorescent probes.
Assuntos
Corantes Fluorescentes , Heparina , Peptídeos , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Heparina/análise , Heparina/química , Peptídeos/química , Peptídeos/síntese química , Estrutura Molecular , Humanos , Espectrometria de FluorescênciaRESUMO
Soybean proteins (pro) and soybean peptides (pep) are beneficial to the growth and metabolism of Limosilactobacillus reuteri (L. reuteri). However, whether they could assist L. reuteri in inhibiting intestinal pathogens and the inhibition mode of them is still unclear. In this study, a co-culture experiment of L. reuteri LR08 with Escherichia coli JCM 1649 (E. coli) was performed. It showed that pro and pep could still favour the growth of L. reuteri over E. coli under their competition. The inhibition zone experiment showed the digested soybean proteins (dpro) could improve its antibacterial activity by increasing the secretion of organic acids from L. reuteri. Furthermore, digested soybean peptides (dpep) could enhance nitrogen utilization capacity of L. reuteri over E. coli. These results explained the patterns of dpro and dpep assisting L. reuteri in inhibiting the growth of E. coli by regulating its organic acid secretion and the ability of nitrogen utilization.
Assuntos
Limosilactobacillus reuteri , Escherichia coli , Proteínas de Soja/farmacologia , Antibacterianos/farmacologia , Peptídeos/farmacologia , NitrogênioRESUMO
Materials with well-defined electrical resistivity that does not change with temperature or time are important in robotics, communication and automation. However, the challenge of designing such materials has remained elusive due to the temperature-dependent electron-phonon scattering. Moreover, resistive electrical conductors used in flexible and mobile systems under high mechanical loads must possess both high strength and ductility. Achieving such multi-properties presents a fundamental challenge. Here, we solve this problem by combining multicomponent alloy design with atomic-scale chemistry tuning. We term the resultant material 'Resinvar' alloy, due to its invariable resistivity (148 µΩ·cm) over wide temperature ranges from room temperature to 723 K. The alloy also has high tensile strength (948 MPa) at large tensile elongation (53%). The distorted lattice, chemical short-range order and ordered coherent nanoprecipitates in the material enable the invariant resistivity via promoting temperature-independent inelastic electron scattering, and contribute to the excellent strength-ductility synergy by manipulating dislocation slip.
RESUMO
We introduce a strategy to generate uniform illumination. The droplet pinned by a hydrophilic/superhydrophobic heterogeneous surface is oscillated, driven by a laterally placed loudspeaker. The vibrated droplet can be considered as a tunable lens, whose focus and focus length can be real-time tuned. The tunable "lens" is presented as a device for uniform illumination by mechanical manipulation. The incident light is scattered by the vibrated droplet during oscillation, and the irradiance distribution on the image plane becomes larger and more homogenous when the droplet is at resonance.
Assuntos
Biomimética , Interações Hidrofóbicas e Hidrofílicas , Iluminação/métodos , Vibração , Dispositivos Ópticos , Propriedades de SuperfícieRESUMO
Soybean peptides were reported to promote the growth and metabolism of Lacticaseibacillus rhamnosus (L. rhamnosus) Lra05. However, the relationship between L. rhamnosus Lra05 and the characteristics of soybean peptides is still unclear. Therefore, digested soybean peptides (dPEP) after 36 h utilization by L. rhamnosus Lra05 were identified and analyzed. We found that L. rhamnosus Lra05 tends to utilize hydrophobic peptides with three to five amino acids residues, and hydrophilic peptides with more than five residues. They also prefer peptides with proline at penultimate C-terminal position or arginine at ultimate C-terminal position. Moreover, fraction 1 (F1) and fraction 7 (F7) acquired from dPEP using RP-HPLC exhibited the strongest growth and metabolism promoting effects, and the utilized characteristics of F1 and F7 were similar with those of dPEP. These results explained why soybean peptides could promote L. rhamnosus to some extent and strengthen theoretical basis for the application of soybean peptides as potential prebiotics.
Assuntos
Glycine max , Lacticaseibacillus rhamnosus , Glycine max/metabolismo , Peptídeos/química , Aminoácidos/metabolismo , Prolina/metabolismo , Arginina/metabolismoRESUMO
Despite the extremely high hardness of recently proposed high-entropy carbides (HECs), the low fracture toughness limits their applications in harsh mechanical environment. Here, we introduce a metastability engineering strategy to achieve superhard HECs with enhanced toughness via in-situ metastable particles. This is realized by developing a (WTaNbZrTi)C HEC showing a solid solution matrix with uniformly dispersed in-situ tetragonal and monoclinic ZrO2 particles. Apart from a high hardness of 21.0 GPa, the HEC can obtain an enhanced fracture toughness of 5.89 MPa·m1/2, significantly exceeding the value predicted by rule of mixture and that of other reported HECs. The toughening effect is primarily attributed to the transformation of the metastable tetragonal ZrO2 particles under mechanical loading, which promotes crack tip shielding mechanisms including crack deflection, crack bridging and crack branching. The work demonstrates the concept of using in-situ metastable particles for toughening bulk high-entropy ceramics by taking advantage of their compositional flexibility.
RESUMO
Soybean protein and peptides have the potential to promote the growth of Lactobacillus, but the mechanisms involved are not well understood. The purpose of this study is to investigate differentially expressed genes (DEGs) of Limosilactobacillus reuteri (L. reuteri) LR08 responding to soybean protein and peptides using transcriptome. The results showed that both digested protein (dpro) and digested peptides (dpep) could enhance a purine biosynthesis pathway which could provide more nucleic acid and ATP for bacteria growth. Moreover, dpep could be used instead of dpro to promote the ABC transporters, especially the genes involved in the transportation of various amino acids. Interestingly, dpro and dpep played opposite roles in modulating DEGs from the acc and fab gene families which participate in fatty acid biosynthesis. These not only provide a new direction for developing nitrogen-sourced prebiotics in the food industry but could also help us to understand the fundamental mechanism of the effects of dpro and dpep on their growth and metabolisms and provides relevant evidence for further investigation.
RESUMO
Lactic acid bacteria are one of the most pivotal probiotics. Promoting their viability could be an effective method to modulate the balance of intestinal flora, thereby improving human health. The current solution is to take advantage of carbon-sourced prebiotics, while protein and peptides with potential prebiotic functions have not been investigated. Soy proteins and peptides have been proven to enhance the growth and metabolism of Lactobacillus. However, research on the relationship between strains of lactobacilli and the structure of soybean peptides is still limited. In the present study, soybean protein and peptides effectively increased the growth and organic acid secretion of Limosilactobacillus reuteri LR08. Additionally, soybean peptides and fructooligosaccharides showed synergistic effects in modulating Limosilactobacillus reuteri LR08. Fraction 1 acquired from soy peptides using RP-HPLC exhibited the most effectiveness and several novel peptides were identified. These results could theoretically and practically benefit soybean peptide application as a potential prebiotic.