Self-Amplified HF Release and Polymer Deconstruction Cascades Triggered by Mechanical Force.

Hydrogen fluoride (HF) is a versatile reagent for material transformation, with applications in self-immolative polymers, remodeled siloxanes, and degradable polymers. The responsive in situ generation of HF in materials therefore holds promise for new classes of adaptive material systems. Here, we report the mechanochemically coupled generation of HF from alkoxy-gem-difluorocyclopropane (gDFC) mechanophores derived from the addition of difluorocarbene to enol ethers. Production of HF involves an initial mechanochemically assisted rearrangement of gDFC mechanophore to α-fluoro allyl ether whose regiochemistry involves preferential migration of fluoride to the alkoxy-substituted carbon, and ab initio steered molecular dynamics simulations reproduce the observed selectivity and offer insights into the mechanism. When the alkoxy gDFC mechanophore is derived from poly(dihydrofuran), the α-fluoro allyl ether undergoes subsequent hydrolysis to generate 1 equiv of HF and cleave the polymer chain. The hydrolysis is accelerated via acid catalysis, leading to self-amplifying HF generation and concomitant polymer degradation. The mechanically generated HF can be used in combination with fluoride indicators to generate an optical response and to degrade polybutadiene with embedded HF-cleavable silyl ethers (11 mol %). The alkoxy-gDFC mechanophore thus provides a mechanically coupled mechanism of releasing HF for polymer remodeling pathways that complements previous thermally driven mechanisms.

Domain-limited thermal transformation preparation of novel graphitized carbon-supported layered double oxides for efficient tetracycline degradation.

The resource utilization of industrial lignin to construct high-performance catalysts for wastewater treatment field is pioneering research. Herein, the novel graphitized carbon-supported CuCoAl-layered double oxides (LDOs-GC) were successfully designed by the domain-limited thermal transformation technology using sodium lignosulfonate (LS) self-assembled CuCoAl-layered double hydroxides as the precursor. The optimized LDOs-GC catalyst owned the excellent tetracycline (TC) degradation of 98.0% within 15 min by activated peroxymonosulfate (PMS) under optimal conditions (20 mg/L catalyst, 1.5 mM PMS, 30 mg/L TC). The density of metal ions in the catalyst and the synergistic interaction between graphitized carbon (GC) and metal ions played a major role in TC degradation. Based on a comprehensive analysis, the TC degradation in LDOs-GC/PMS system was proved to be accomplished by a combination of free radicals (SO4·- and HO·) and non-radicals (1O2). Meanwhile, the possible degradation pathways of TC were proposed by the analysis of TC degradation intermediates and a comprehensive analysis of the rational reaction mechanism for TC degradation by LDOs-GC/PMS system was also performed. This work provides a new strategy for developing novel high-performance catalysts from industrial waste, while offering a green, cheap and sustainable approach to antibiotic degradation.

Conformational and functional changes from deamidation of wheat gluten with electrochemical treatment.

BACKGROUND: In this paper, wheat gluten (WG) was modified by electrochemical deamidation. The effects of electrochemical treatment time on the conformation and functional properties of WG and its mechanism were studied. RESULTS: Wheat gluten demonstrated a maximum deamidation of 50.94%. Fourier transform infrared spectroscopy (FTIR) showed a decrease in α-helix and ß-sheets and an increase in ß-turns and random coils, indicating that the secondary structure of WG became looser and more disordered with increased molecular flexibility. Electrochemical deamidation significantly increased the net charge and solubility of WG, the emulsifying activity index (EAI) increased from 8.53 to 15.66 m2 g-1 , the foaming capacity (FC) increased from 4.55 to 13.72 cm3 , and the water-holding capacity (WHC) and oil-holding capacity (OHC) reached maximum levels of 8.42 g g-1 and 7.45 g g-1 , respectively, at 90 min. CONCLUSION: Electrochemical deamidation appears to be a useful technique to improve the processing characteristics of WG. © 2023 Society of Chemical Industry.

Mechanochemistry of Cubane.

We report the mechanochemical reactivity of the highly strained pentacyclic hydrocarbon cubane. The mechanical reactivity of cubane is explored for three regioisomers with 1,2-, 1,3-, and 1,4-substituted pulling attachments. Whereas all compounds can be activated thermally, mechanical activation is observed via pulsed ultrasonication of cubane-containing polymers only when force is applied via 1,2-attachment. The single observed product of the force-coupled reaction is a thermally inaccessible syn-tricyclooctadiene, in contrast to cyclooctatetraene (observed thermally) or a pair of cyclobutadienes that would result from sequential cyclobutane scission. We further quantify the mechanochemical reactivity of cubane by single molecule force spectroscopy, and force-coupled rate constants for ring opening reach ∼33 s-1 at a force of ∼1.55 nN, lower than forces of 1.8-2.0 nN that are typical of conventional cyclobutanes.

Restoring mitochondrial function and normalizing ROS-JNK/MAPK pathway exert key roles in glutamine ameliorating bisphenol A-induced intestinal injury.

Bisphenol A (BPA) is toxic to the reproductive and nervous system, even carcinogenetic in humans and animals. However, few studies focused on effects of BPA on the intestinal tract. Here, we detected BPA-induced injuries on intestinal mucosa and explored a reliable approach to counteract BPA effects. C57BL/6J mice were gavage BPA or BPA accompanied with ingestion of 4% (w/w) of glutamine for 4-wks. In vitro, IEC-6 cells were treated with 0.4 mmol/L BPA for 6 hours mimicking acute injury and 0.2 mmol/L BPA for 12 hours followed with or without the inclusion of 4 mmol/L glutamine for 12 hours to determine cell renewal, mitochondrial function and ROS-JNK/MAPK pathway upon moderate BPA exposure. As results, BPA exposure caused severe intestinal injury, and disturbed intestinal epithelial cell proliferation and apoptosis, accompanied with mitochondrial malfunction and activated JNK/MAPK pathway as well. Notably, glutathione metabolism was implicated in BPA-induce injury. Glutamine could well rescue cell renewal and mitochondrial function from BPA exposure-induced injuries. In conclusion, we demonstrated impaired effect of BPA exposure on intestinal functions, which could be well counteracted by glutamine partly via restoring mitochondrial function and normalizing ROS-JNK/MAPK pathway. Thereby, we provided a novel application of glutamine to rescue intestinal injury.

Mechanochemical Regulation of Oxidative Addition to a Palladium(0) Bisphosphine Complex.

Here, we report the effect of force applied to the biaryl backbone of a bisphosphine ligand on the rate of oxidative addition of bromobenzene to a ligand-coordinated palladium center. Local compressive and tensile forces on the order of 100 pN were generated using a stiff stilbene force probe. A compressive force increases the rate of oxidative addition, whereas a tensile force decreases the rate, relative to that of the parent complex of strain-free ligand. Rates vary by a factor of ∼6 across ∼340 pN of force applied to the complexes. The crystal structures and DFT calculations support that force-induced perturbation of the geometry of the reactant is negligible. The force-rate relationship observed is mainly attributed to the coupling of force to nuclear motion comprising the reaction coordinate. These observations inform the development of catalysts whose activity can be tuned by an external force that is adjusted within a catalytic cycle.

Dynamic membrane proteome of adipogenic and myogenic precursors in skeletal muscle highlights EPHA2 may promote myogenic differentiation through ERK signaling.

The balance of myogenic and adipogenic differentiation is crucial for skeletal muscle homeostasis. Given the vital role of membrane proteins (MBPs) in cell signal perception, membrane proteomics was conducted to delineate mechanisms regulating differentiation of adipogenic and myogenic precursors in skeletal muscle. Adipogenic and myogenic precursors with divergent differentiation potential were isolated from the longissimus dorsi muscle of neonatal pigs by the preplate method. A total of 85 differentially expressed MBPs ( P < 0.05 and fold change ≥1.2 or ≤0.83) between 2 precursors were detected via isobaric tags for relative and absolute quantitation (iTRAQ) assay, including 67 up-regulated and 18 down-regulated in myogenic precursors. Functional enrichment analysis uncovered that myogenic and adipogenic precursors showed significant differences in cytoskeleton organization, syncytium formation, environmental information processing, and organismal systems. Furthermore, key MBPs in regulating cell differentiation were also characterized, including ITGB3, ITGAV, ITPR3, and EPHA2. Noteworthily, EPHA2 was required for myogenic differentiation, and it may promote myogenic differentiation through ERK signaling. Collectively, our study provided an insight into the distinct MBP profile between myogenic and adipogenic precursors in skeletal muscle and served as a solid basis for supporting the role of MBPs in regulating differentiation.-Zhang, X., Wang, L., Qiu, K., Xu, D., Yin, J. Dynamic membrane proteome of adipogenic and myogenic precursors in skeletal muscle highlights EPHA2 may promote myogenic differentiation through ERK signaling.

Protein Expression Landscape Defines the Differentiation Potential Specificity of Adipogenic and Myogenic Precursors in the Skeletal Muscle.

The balance of adipogenic and myogenic differentiation of skeletal muscle-derived mesenchymal stem cells is particularly important in muscle development and intramuscular fat deposition. This study aimed to explore the differential regulation between adipogenic and myogenic precursors by comparative analysis of their global proteome expression profile. Adipogenic and myogenic precursors isolated from neonatal porcine longissimus dorsi muscle by the preplate method were verified for their unique and distinct differentiation potential under myogenic or adipogenic induction. A total of 433 differentially expressed proteins (DEP) ( P < 0.05 and FC > 1.20 or <0.83) between adipogenic and myogenic precursors were detected via a tandem mass tag (TMT)-coupled LC-MS/MS approach, including 339 up-regulated and 94 down-regulated proteins in myogenic precursors compared with adipogenic precursors. On the basis of functional annotation and enrichment analysis of 433 DEP, adipogenic and myogenic precursors showed significantly different metabolic pattern of energy substances and differential regulations of gene expression, cell structure and development, ion homeostasis, and cell motility and migration. Three pathways including PPAR signaling pathway, phosphatidylinositol signaling system, and autophagy signaling pathway, which was differentially regulated between adipogenic and myogenic precursors, was also discovered to play crucial roles in cell differentiation. In conclusion, these differentiated regulation patterns between the two cell subsets of mesenchymal precursors together defines their differentiation potential specificity.

A new method for noninvasive venous blood oxygen detection.

BACKGROUND: Blood oxygen saturation of vein (SvO2) is an important clinical parameter for patient monitoring. However, the existing clinical methods are invasive, expensive, which are also painful for patients. METHODS: Based on light-absorption, this study describes a new noninvasive SvO2 measurement method by using external stimulation signal to generate cyclical fluctuation signal in the vein, which overcomes the low signal-to-noise ratio problem in the measurement process. In this way, the value of SvO2 can be obtained continuously in real time. RESULTS: The experimental results demonstrate that the method can successfully measure venous oxygen saturation by artificial addition of stimulation. Under hypoxic conditions, the system can reflect the overall decline of venous oxygen saturation better. When the results measured by the new method are compared with those measured by the invasive method, the root mean square error of the difference is 5.31 and the correlation coefficient of the difference is 0.72. The new method can be used to measure SvO2 and evaluate body oxygen consumption, and its accuracy needs improvement. CONCLUSIONS: Real-time and continuous monitoring can be achieved by replacing invasive method with noninvasive method, which provides more comprehensive clinical information in a timely manner and better meet the needs of clinical treatment. However, the accuracy of the new noninvasive SvO2 measurement based on light-absorption has to be further improved.

[Characteristic wavelength variable optimization of near-infrared spectroscopy based on Kalman filtering].

Combining classical Kalman filter with NIR analysis technology, a new method of characteristic wavelength variable selection, namely Kalman filtering method, is presented. The principle of Kalman filter for selecting optimal wavelength variable was analyzed. The wavelength selection algorithm was designed and applied to NIR detection of soybean oil acid value. First, the PLS (partial leastsquares) models were established by using different absorption bands of oil. The 4 472-5 000 cm(-1) characteristic band of oil acid value, including 132 wavelengths, was selected preliminarily. Then the Kalman filter was used to select characteristic wavelengths further. The PLS calibration model was established using selected 22 characteristic wavelength variables, the determination coefficient R2 of prediction set and RMSEP (root mean squared error of prediction) are 0.970 8 and 0.125 4 respectively, equivalent to that of 132 wavelengths, however, the number of wavelength variables was reduced to 16.67%. This algorithm is deterministic iteration, without complex parameters setting and randomicity of variable selection, and its physical significance was well defined. The modeling using a few selected characteristic wavelength variables which affected modeling effect heavily, instead of total spectrum, can make the complexity of model decreased, meanwhile the robustness of model improved. The research offered important reference for developing special oil near infrared spectroscopy analysis instruments on next step.

The impact of sustainable development planning on urban ecological resilience in resource-based cities: evidence from China.

Enhancing resource cities' resilience and advancing their sustainable development are imperatives, particularly in light of the "dual-carbon" agenda. Double-difference and spatial double-difference models are developed based on the panel data of 281 Chinese cities from 2005 to 2020 to investigate the effects of implementing the National Plan for the Sustainable Development of Resource-Based Cities on the level of ecological resilience in Chinese cities. This paper found that the National Sustainable Development Plan for Resource-Based Cities significantly improves the ecological resilience level of Chinese cities, and the findings are robust. The impacts of implementing the Plan on the ecological resilience of cities of different growth types, regions, and resource types are heterogeneous. Further study finds a spatial spillover effect of implementing the Plan on the ecological resilience of cities, which can improve the ecological resilience level of neighboring cities through spillover effects while improving the ecological resilience level of cities in the region. Based on these new findings, this study provides some policy implications for better advancing sustainable urban development.

Effect of ultrasonic power on delivery of quercetin in emulsions stabilized using octenyl succinic anhydride (OSA) modified broken japonica rice starch.

In this study, emulsions stabilized by octenyl succinic anhydride-modified broken japonica rice starch (OSA-BJRS) were prepared at different ultrasonic power intensities for the delivery, controlled release, and improved bioavailability of quercetin. The OSA-BJRS emulsions ultrasonicated at 400 W exhibited the highest encapsulation efficiency (89.37 %) and loading efficiency (58.34 %) of quercetin, the smallest volume-average droplet diameter (0.51 µm) and polydispersity index (0.19), the highest absolute value of the ζ-potential (26.73 mV), and the highest apparent viscosity and viscoelasticity. The oxidation stability, storage stability, thermal stability, and salt ion stability of the emulsions were also notably improved by the ultrasonication treatment. In addition, the results of the simulated in vitro digestion demonstrated that the ultrasonicated OSA-BJRS emulsions had an enhanced quercetin delivery performance and could stably transport quercetin to the small intestine for digestion. The OSA-BJRS emulsion ultrasonicated at 400 W exhibited the highest cumulative release rate (95.91 %) and the highest bioavailability (30.48 %) of quercetin. This suggests that OSA-BJRS emulsions prepared by ultrasonication can be considered effective delivery systems for hydrophobic functional components.

Effect of deodorization conditions on fatty acid profile, oxidation products, and lipid-derived free radicals of soybean oil.

Oxidative stability is a key quality characteristic of edible oils, and the oil's antioxidant capacity decreases during the deodorization stage. This study explores the changes in radical formation, molecular structure, oxidative characteristics, fatty acids, and main bioactive compounds in soybean oil during deodorization. The lag phase decreased, whereas the total amount of spins of free radicals increased as the deodorization time increased from 90 to 150 min. The total amount of spins and percentage of alkyl radicals varied dramatically under different times and temperatures (220 âˆ¼ 260 ℃). Results showed that identifying and quantifying the formed radicals can provide useful information for monitoring and controlling oil oxidation in vegetable oil refining systems. Therefore, to control early oxidation events, maximize refined oil product yield, and reduce energy consumption in the refining plant, the priority should be to minimize temperature during the oil refining process and then shorten the deodorization time.

Rapid quantitative analysis of soybean protein isolates secondary structure by two-dimensional correlation infrared spectroscopy through pH perturbation.

The infrared spectroscopy (IR) signal of protein is prone to being covered by impurity signals, and the accuracy of the secondary structure content calculated using spectral data is poor. To tackle this challenge, a rapid high-precision quantitative model for protein secondary structure was proposed. Firstly, a two-dimensional correlation calculation was performed based on 60 groups of soybean protein isolates (SPI) infrared spectroscopy data, resulting in a two-dimensional correlation infrared spectroscopy (2DCOS-IR). Subsequently, the optimal characteristic bands of the four secondary structures were extracted from the 2DCOS-IR. Ultimately, partial least squares (PLS), long short-term memory (LSTM), and bidirectional long short-term memory (BILSTM) algorithms were used to model the extracted characteristic bands and predict the content of SPI secondary structure. The findings suggested that BILSTM combined with 2DCOS-IR model (2DCOS-BILSTM) exhibited superior predictive performance. The prediction sets for α-helix, ß-sheet, ß-turn, and random coil were designated as 0.9257, 0.9077, 0.9476, and 0.8443, respectively, and their corresponding RMSEP values were 0.26, 0.48, 0.20, and 0.15. This strategy enhances the precision of IR and facilitates the rapid identification of secondary structure components within SPI, which is vital for the advancement of protein industrial production.

Self-assembly embedding of curcumin by alkylated rice bran protein.

Lysine-rich rice bran protein (RBP) can be used as raw material for alkylation modification to improve the self-assembly performance of protein. The results of 1H NMR, degree of alkylation, and DSC analysis showed that the alkyl chain was successfully attached to the RBP. The surface hydrophobicity and absolute ζ-potential increased. The three-dimensional structure of the alkylated RBP (ARBP) become more porous and ARBP-2 was selected as the material for embedding curcumin. The XRD results revealed that curcumin induced self-aggregation of ARBP-2 and the inclusion of curcumin was attained. The maximum encapsulation efficiency of curcumin was 82.67 % and the maximum loading amount was 171.37 g/100 g RBP. The results of atomic force microscopy (AFM), particle size, and polydispersity index (PDI) analyses revealed that the particles in the system were aggregated after curcumin was added. Curcumin was well protected by encapsulation in the self-assembled particles. Thus, this study provides a new strategy for the embedding and delivery of curcumin.

Selection of a representative matrix for the multiresidue analysis of nine ß-agonists in animal tissues and urine with LC-MS/MS.

In the determination of nine ß-agonists including salbutamol, terbutaline, cimaterol, fenoterol, clorprenaline, ractopamine, tulobuterol, clenbuterol and penbuterol in porcine, bovine, lamb and chicken muscle, liver and urine samples with LC-MS/MS, calibration curves prepared in solvent (SC) were compared with those prepared in each matrix (MC) for all analytes. Significant differences (P < 0.05) between SC and each MC for most analytes indicated the existence of matrix effects and the necessity of using MC for quantitation to compensate MEs. Then MC in each muscle, liver and urine sample was compared with the select potential representative matrix, followed by validating the recoveries of nine analytes calculated through the MC in the potential representative matrix and MC in their corresponding matrices, respectively. The results suggested that porcine muscle could be selected as a representative matrix to calibrate ß-agonist residues in bovine, lamb and chicken muscle samples.

Multiresidue analysis of nine ß-agonists in animal muscles by LC-MS/MS based on a new polymer cartridge for sample cleanup.

A novel, sensitive, and reliable LC-MS/MS method for multiresidue analysis of nine ß-agonists (salbutamol, terbutaline, cimaterol, fenoterol, clorprenaline, ractopamine, tulobuterol, clenbuterol, and penbuterol) in four farm animal muscles was developed. Muscle matrix was extracted with acetonitrile-10% sodium carbonate solution, and then was subjected to cleanup using a SPE cartridge packed with new polymer synthesized in acetone. Chromatographic separation of the components was performed on a Luna C18 column using 0.1% of formic acid in water and acetonitrile. The mass spectrometer was operated in the positive electrospray mode. Good precision and accuracy were obtained for all analytes (except for fenoterol) at the spiked three levels of 1.0, 10, and 50 µg/kg. The decision limit and detection capability of nine ß-agonists ranged from 0.04 to 0.18 and 0.15 to 0.69 µg/kg, respectively. The method developed was successfully applied to the monitoring of nine ß-agonists in pork, beef, mutton, and chicken from Chinese markets.

Reset Event-Triggered Adaptive Fuzzy Consensus for Nonlinear Fractional-Order Multiagent Systems With Actuator Faults.

This article studies the problem of event-triggered adaptive fault-tolerant fuzzy output feedback consensus tracking control for nonlinear fractional-order multiagent systems with actuator failures under a directed graph. Considering the fact that the actual system works near the equilibrium point most of the time, a novel dynamic event-triggering strategy with the reset mechanism is proposed, where the dynamic threshold can be actively adjusted according to the preset conditions, so that the resource utilization can be further reduced. Based on an improved event-based consensus error, the state estimator about the derivative of reference trajectory and the adaptive law about the information of graph are constructed, which makes distributed consensus tracking control achieved without obtaining global information. Then, by introducing two adaptive compensating terms to deal with actuator failures and event-triggered measurement errors, it is shown in the sense of fractional-order stability criterion that tracking errors can converge to a compact set even if the fault parameters and modes are completely unknown. Finally, the correctness of the presented method is verified by a simulation example.

Has pilot zones policy for green finance reform and innovations improved the level of green financial development and environmental quality?

This study uses the green finance reform and innovation pilot zone policy approved by the State Council in 2017 as a quasi-natural experiment to explore whether the implementation of the policy has improved the level of green finance development and environmental quality in Chinese cities at the prefecture level and above. The results show that the green financial reform and innovation pilot zone policy can significantly improve the level of regional green financial development and environmental quality, and the results are robust. Further heterogeneity analysis finds that the green financial reform and innovation pilot zone policy have heterogeneous effects on the level of green financial development and environmental quality in different regions, sizes, environmental regulation intensity, financial development levels, and cities of different administrative levels. Based on this conclusion, suggestions are made that the scope should be further expanded and green finance policies should be formulated differently.

Covalent binding of ultrasound-treated japonica rice bran protein to catechin: Structural and functional properties of the complex.

Due to the existence of many disulfide bonds in japonica rice bran protein (JRBP) molecules, their solubility is poor, which seriously affects other functional properties. To improve the functional characteristics of JRBP molecules, they were processed by ultrasound technology, and JRBP-catechin (CC) covalent complex was prepared. The structural and functional properties of indica and japonica rice bran proteins and their complexes were compared; furthermore, the changes in the structural and functional properties of JRBP-CC under different ultrasound conditions were investigated. The results showed that compared with indica rice bran protein (IRBP), the secondary structure of JRBP-CC was very different, the water holding capacity (WHC) was higher, and the emulsification performance was better. Different ultrasound conditions had different effects on the functional properties of JRBP-CC. When the ultrasound power was 200 W, the λmax redshift of the JRBP-CC complex was the most significant, the particle size was the smallest, the absolute value of the zeta potential was the largest, and the hydrophobicity and microstructure of the JRBP-CC complex were the best. Concurrently, the maximum WHC and oil holding capacity (OHC) of JRBP-CC under these conditions were 7.54 g/g and 6.87 g/g, respectively. Moreover, the emulsifying activity index (EAI) and emulsifying stability index (ESI) were 210 m2/g and 47.8 min, respectively, and the scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ABTS+ were 71.96 % and 80.07 %, respectively.