Double Superconducting Dome of Quasi Two-Dimensional TaS2 in Non-Centrosymmetric van der Waals Heterostructure.

Two-dimensional van der Waals heterostructures (2D-vdWHs) based on transition metal dichalcogenides (TMDs) provide unparalleled control over electronic properties. However, the interlayer coupling is challenged by the interfacial misalignment and defects, which hinders a comprehensive understanding of the intertwined electronic orders, especially superconductivity and charge density wave (CDW). Here, by using pressure to regulate the interlayer coupling of non-centrosymmetric 6R-TaS2 vdWHs, we observe an unprecedented phase diagram in TMDs. This phase diagram encompasses successive suppression of the original CDW states from alternating H-layer and T-layer configurations, the emergence and disappearance of a new CDW-like state, and a double superconducting dome induced by different interlayer coupling effects. These results not only illuminate the crucial role of interlayer coupling in shaping the complex phase diagram of TMD systems but also pave a new avenue for the creation of a novel family of bulk heterostructures with customized 2D properties.

Development of a ratiometric fluorescent probe for the detection of peroxynitrite.

Peroxynitrite is one of the important reactive oxygen species in the human body and is closely related to the physiological and pathological processes of many diseases. Therefore, the development of probes to detect peroxynitrite is important for diagnostic and pathologic studies of many diseases. In this work, a ratiometric probe was designed using benzopyran as the recognition site, and the sensitivity and selectivity of the probe were tuned by modification of substituents on benzopyran. Upon reaction with peroxynitrite, the color of the solution changes to the naked eye (from blue to yellow), and the fluorescence changes from red to blue. The probe SJ has the advantages of large Stokes shift (237 nm), fast response (≤10 s), wide linear range, good selectivity, low detection line (21.3 nm), and low cytotoxicity. Probe SJ has been successfully used for bioimaging of endogenous and exogenous peroxynitrite.

Boosting one-step degradation of shrimp shell waste to produce chitin oligosaccharides at smart nanoscale enzyme reactor with liquid-solid system.

Chitin oligosaccharides (CTOS) possess potential applications in food, medicine, and agriculture. However, lower mass transfer and catalytic efficiency are the main kinetic limitations for the production of CTOS from shrimp shell waste (SSW) and crystalline chitin. Chemical or physical methods are usually used for pretreatment to improve chitinase hydrolysis efficiency, but this is not eco-friendly and cost-effective. To address this challenge, a chitinase nanoreactor with the liquid-solid system (BcChiA1@ZIF-8) was manufactured to boost the one-step degradation of SSW and crystalline chitin. Compared with free enzyme, the catalytic efficiency of BcChiA1@ZIF-8 on colloidal chitin was significantly improved to 142 %. SSW and crystalline chitin can be directly degraded by BcChiA1@ZIF-8 without any pretreatments. The yield of N, N'-diacetylchitobiose [(GlcNAc)2] from SSW and N-acetyl-D-glucosamine (GlcNAc) from crystalline chitin was 2 times and 3.1 times than that of free enzyme, respectively. The reason was that BcChiA1@ZIF-8 with a liquid-solid system enlarged the interface area, increased the collision frequency between enzyme and substrate, and improved the large-substrates binding activity of chitinase. Moreover, the biphasic system exhibited excellent stability, and the design showed universal applicability. This strategy provided novel guidance for other polysaccharide biosynthesis and the conversion of environmental waste into carbohydrates.

Exciton engineering of 2D Ruddlesden-Popper perovskites by synergistically tuning the intra and interlayer structures.

Designing two-dimensional halide perovskites for high-performance optoelectronic applications requires deep understanding of the structure-property relationship that governs their excitonic behaviors. However, a design framework that considers both intra and interlayer structures modified by the A-site and spacer cations, respectively, has not been developed. Here, we use pressure to synergistically tune the intra and interlayer structures and uncover the structural modulations that result in improved optoelectronic performance. Under applied pressure, (BA)2(GA)Pb2I7 exhibits a 72-fold boost of photoluminescence and 10-fold increase of photoconductivity. Based on the observed structural change, we introduce a structural descriptor χ that describes both the intra and interlayer characteristics and establish a general quantitative relationship between χ and photoluminescence quantum yield: smaller χ correlates with minimized trapped excitons and more efficient emission from free excitons. Building on this principle, we design a perovskite (CMA)2(FA)Pb2I7 that exhibits a small χ and an impressive photoluminescence quantum yield of 59.3%.

Effect of Neutral Protease on Freshness Quality of Shucked Pacific Oysters at Different Storage Conditions.

The aim of this study was to investigate the effect of neutral protease treatment on the biochemical properties of various parts of Pacific oysters (Crassostrea gigas) under different storage conditions. The mechanism of quality degradation in the mantle, adductor muscle, gill, and trunk of treated oysters stored at -1.5 °C (superchilling) or 4 °C (refrigeration) for several days using different storage methods was studied. The results showed that the oyster treated with the enzyme exhibited higher glycogen content, flavor nucleotide content, and sensory scores compared to the control group. Superchilling at -1.5 °C was observed to slow the increase in total volatile basic nitrogen (TVB-N), total viable count (TVC), and pH, while maintaining sensory scores better than refrigeration at 4 °C. Both wet superchilling (WS) and dry exposed superchilling (DeS) methods effectively preserved freshness and quality at -1.5 °C. The freshness of the oysters' body trunk changed most significantly. K value, K' value, and AEC value, as the evaluation indexes of oyster freshness, were affected by the storage medium. Therefore, neutral protease enhances the flavor of oysters in a short time, and oysters stored in wet superchilling or dry exposed superchilling conditions have an extended shelf life.

Solubility determination and thermodynamic model analysis of L-α-glyceryl phosphorylcholine in different organic solvents of 278.15 K to 323.15 K.

L-α-glyceryl phosphorylcholine, also referred to as choline ethanol phosphate and phosphocholine glycerophosphate, is a naturally occurring metabolite of water-soluble phospholipids in animals. This molecular property is important for informing the crystallization and purification of drugs. The solubility of L-α-glyceryl phosphorylcholine was determined in ten pure solvents and three mixed solvents under atmospheric pressure. The experimental results indicate that L-α-glyceryl phosphorylcholine is most soluble in methanol and least soluble in acetone. Additionally, the solubility of L-α-glyceryl phosphorylcholine was found to increase with temperature within the experimental range. Furthermore, the solubility of L-α-glyceryl phosphorylcholine in binary solvents is dependent on the proportion of positive solvent and temperature. The solubility of L-α-glyceryl phosphorylcholine increases with the proportion of positive solvent. XRD and DSC results indicate that the crystal form of L-α-glyceryl phosphorylcholine remains unchanged before and after dissolution in the reagent, and its melting point temperature is 413.15 K. Various models, including the modified Apelblat model, λh model, Jouyban-Acree model, SUN model, and CNIBS/R-K model, were used to fit the solubility data of L-α-glyceryl phosphorylcholine in different solvents. The study found that the modified Apelblat model and CNIBS/R-K model were the most appropriate for fitting the data. The KAT-LSER model was used to analyze the molecular interactions between solvents and solutes, revealing that the solvent step method with non-specific polarity/polarization interaction had the greatest impact on solubility.

Tunable positions of Weyl nodes via magnetism and pressure in the ferromagnetic Weyl semimetal CeAlSi.

The noncentrosymmetric ferromagnetic Weyl semimetal CeAlSi with simultaneous space-inversion and time-reversal symmetry breaking provides a unique platform for exploring novel topological states. Here, by employing multiple experimental techniques, we demonstrate that ferromagnetism and pressure can serve as efficient parameters to tune the positions of Weyl nodes in CeAlSi. At ambient pressure, a magnetism-facilitated anomalous Hall/Nernst effect (AHE/ANE) is uncovered. Angle-resolved photoemission spectroscopy (ARPES) measurements demonstrated that the Weyl nodes with opposite chirality are moving away from each other upon entering the ferromagnetic phase. Under pressure, by tracing the pressure evolution of AHE and band structure, we demonstrate that pressure could also serve as a pivotal knob to tune the positions of Weyl nodes. Moreover, multiple pressure-induced phase transitions are also revealed. These findings indicate that CeAlSi provides a unique and tunable platform for exploring exotic topological physics and electron correlations, as well as catering to potential applications, such as spintronics.

Electrospun nanofibers electrostatically adsorb heterotrophic nitrifying and aerobic denitrifying bacteria to degrade nitrogen in wastewater.

Nanofibers were prepared by electrospinning a mixture of polycaprolactone and silica, and modified to improve the hydrophilicity and stability of the material and to degrade nitrogenous wastewater by adsorbing heterotrophic nitrifying aerobic denitrifying (Ochrobactrum anthropic). The immobilized bacteria showed highly efficient simultaneous nitrification-denitrification ability, which could convert nearly 90 % of the initial nitrogen into gaseous nitrogen under aerobic conditions, and the average TN removal rate reached 5.59 mg/L/h. The average ammonia oxidation rate of bacteria immobilized by modified nanofibers was 7.36 mg/L/h, compared with 6.3 mg/L/h for free bacteria and only 4.23 mg/L/h for unmodified nanofiber-immobilized bacteria. Kinetic studies showed that modified nanofiber-immobilized bacteria complied with first-order degradation kinetics, and the effects of extreme pH, temperature, and salinity on immobilized bacteria were significantly reduced, while the degradation rate of free bacteria produced larger fluctuations. In addition, the immobilized bacterial nanofibers were reused five times, and the degradation rate remained stable at more than 80 %. At the same time, the degradation rate can still reach 50 % after 6 months of storage at 4 °C. It also demonstrated good nitrogen removal in practical wastewater treatment.

Effect of ultrasound combined with pineapple protease treatment on the tenderness of dried shrimp.

BACKGROUND: In order to improve the tenderness of dried shrimp products as well as to reduce the hardness of the meat during the drying process, shrimp were treated with ultrasound combined with pineapple protease and the tenderization condition was optimized by measuring the texture and shear force of dried shrimp. In addition, the sulfhydryl content, myofibril fragmentation index (MFI) and microstructure were also examined to clarify the mechanisms of shrimp tenderization. RESULTS: The results showed UB1 group with ultrasonic power of 100 W, heating temperature of 50 °C and pineapple protease concentration of 20 U mL-1 were the optimum tenderization conditions, where shrimp showed the lowest hardness (490.76 g) and shear force (2006.35 gf). Microstructure as well as sodium dodecyl sulfate-polyacrylamide gel electrophoresis results suggested that during the tenderization process the muscle segments of shrimps were broken, degradation of myofibrillar proteins occurred, and MFI values and total sulfhydryl content increased significantly (P < 0.05) (MFI value = 193.6 and total sulfhydryl content = 93.93 mmol mg-1 protein for UB 1 group). CONCLUSION: Ultrasound combined with bromelain could be used as a simple and effective tenderization method for the production of tender dried shrimp. The best conditions were 100 W ultrasonic power, 50 °C ultrasonic temperature, and 20 U mL-1 bromelain. © 2024 Society of Chemical Industry.

Iron deficiency anemia: a critical review on iron absorption, supplementation and its influence on gut microbiota.

Iron deficiency anemia (IDA) caused by micronutrient iron deficiency has attracted global attention due to its adverse health effects. The regulation of iron uptake and metabolism is finely controlled by various transporters and hormones in the body. Dietary iron intake and regulation are essential in maintaining human health and iron requirements. The review aims to investigate literature concerning dietary iron intake and systemic regulation. Besides, recent IDA treatment and dietary iron supplementation are discussed. Considering the importance of the gut microbiome, the interaction between bacteria and micronutrient iron in the gut is also a focus of this review. The iron absorption efficiency varies considerably according to iron type and dietary factors. Iron fortification remains the cost-effective strategy, although challenges exist in developing suitable iron fortificants and food vehicles regarding bioavailability and acceptability. Iron deficiency may alter the microbiome structure and promote the growth of pathogenic bacteria in the gut, affecting immune balance and human health.

PCL/Yam Polysaccharide nanofibrous membranes loaded with self-assembled HP-ß-CD/ECG inclusion complexes for food packaging.

In this study, Polycaprolactone (PCL)/Yam Polysaccharide (YP) fiber membranes loaded the ultrasound-mediated assembly of 2-Hydroxypropyl-ß-cyclodextrin (HP-ß-CD)/Epicatechin gallate (ECG) inclusion complexes were prepared by electrospinning technology for food packaging. Morphology, infrared spectroscopy and X-ray diffraction results showed that the inclusion complexes were successfully assembled. With the addition of inclusion complexes, the average diameter of the fibers increased from 2480.96 to 10179.12 nm, the crystallinity decreased, the thermal stability improved, the hydrophilicity enhanced, and the water vapor permeability enhanced. Meanwhile, thermogravimetry and differential scanning calorimetry results showed that the inclusion complexes formed hydrogen bonds between the fibers, which improved the thermal stability, but the mechanical behavior suffered a certain loss. In addition, the fiber membrane could continuously release ECG within 240 h, which showed excellent antibacterial effects both in vitro and in vivo. These results indicated that the fiber film developed based on electrospinning had a broad application prospect in food packaging.

Comparison of freezing and heating treatment sequence on biochemical properties and flavor of swimming crabs (Portunus Trituberculatus) meat during freeze-thaw cycles.

The objective of this study was to compare the effect of freezing and heating treatment sequences on the biochemical properties and flavor of crab (Portunus trituberculatus) meat during freeze-thaw cycles. The results showed that pH, color, K and microstructure changes in the H-F group were not significant with increasing number of freeze-thaw cycles, but TVB-N values increased and WHC values decreased. However, with the increase in the number of freeze-thaw cycles, pH and WHC significantly decreased and TVB-N, L* and K values significantly increased in the C and F-H groups. Proteins were degraded in all groups, but the lower degree of degradation occurred in the H-F group. Although the total free amino acid content decreased with increasing number of freeze-thaw cycles in each group, the high content of AMP and IMP in the H-F group suggested that it still had a better flavor.

Dual-Functional Tetrahedron Multivalent Aptamer Assisted Amplification-Free CRISPR/Cas12a Assay for Sensitive Detection of Salmonella.

Salmonellosis continues to impose a significant economic burden globally. Rapid and sensitive detection of Salmonella is crucial to preventing the outbreaks of foodborne illnesses, yet it remains a formidable challenge. Herein, a dual-functional tetrahedron multivalent aptamer assisted amplification-free CRISPR/Cas12a assay was developed for Salmonella detection. In the system, the aptamer was programmatically assembled on the tetrahedral DNA nanostructure to fabricate a multivalent aptamer (TDN-multiApt), which displayed a 3.5-fold enhanced avidity over the monovalent aptamer and possessed four CRISPR/Cas12a targeting fragments to amplify signal. Therefore, TDN-multiApt could directly activate Cas12a to achieve the second signal amplification without any nucleic acid amplification. By virtue of the synergism of high avidity and cascaded signal amplifications, the proposed method allowed the ultrasensitive detection of Salmonella as low as 7 cfu mL-1. Meanwhile, this novel platform also exhibited excellent specificity against target bacteria and performed well in the detection of various samples, indicating its potential application in real samples.

Pressure-Induced Superconductivity and Topological Quantum Phase Transitions in the Topological Semimetal ZrTe2.

Topological transition metal dichalcogenides (TMDCs) have attracted much attention due to their potential applications in spintronics and quantum computations. In this work, the structural and electronic properties of topological TMDCs candidate ZrTe2 are systematically investigated under high pressure. A pressure-induced Lifshitz transition is evidenced by the change of charge carrier type as well as the Fermi surface. Superconductivity is observed at around 8.3 GPa without structural phase transition. A typical dome-shape phase diagram is obtained with the maximum Tc of 5.6 K for ZrTe2 . Furthermore, the theoretical calculations suggest the presence of multiple pressure-induced topological quantum phase transitions, which coexists with emergence of superconductivity. The results demonstrate that ZrTe2 with nontrivial topology of electronic states displays new ground states upon compression.

Highly sensitive detection of Salmonella based on dual-functional HCR-mediated multivalent aptamer and amplification-free CRISPR/Cas12a system.

BACKGROUND: Salmonella infection severely threatens human health and causes substantial medical and financial concerns. Sensitive and specific detection of Salmonella in food samples is crucial but remains challenging. While some traditional assays for S. typhimurium are reliable, they suffer from various limitations, such as being time-consuming (culture-based methods), involving intricate nucleic molecular extraction (polymerization chain reaction, PCR), and exhibiting inadequate sensitivity (enzyme-linked immunosorbent assay, ELISA). In this case, it is essential to establish a rapid, simple-operation, and sensitive method for monitoring S. typhimurium to preserve food quality and prevent contamination. RESULT: Herein, an amplification-free detection method for Salmonella was developed by coupling the aptamer magnetic separation with dual-functional HCR (hybridization chain reaction)-scaffold multivalent aptamer and the activity of CRISPR/Cas12a. In the detection system, the dual-functional HCR-scaffold multivalent aptamer with high binding affinity and specificity was fabricated in advance by assembling numerous Salmonella specific aptamers on the long HCR products. In addition to the enhanced affinity, the HCR-multiApt also contains a massive amount of repeated CRISPR-targetable DNA units in its HCR scaffold, which could trigger the trans-cleavage activity of Cas12a. In the presence of target bacteria, the HCR-scaffold multivalent aptamer could attach on the surface of bacteria effectively and amplified the signal of bacteria into CRISPR/Cas12a based fluorescent readout. The proposed detection system allowed for ultrasensitive detection of Salmonella in a linear range from 100 to 107 cfu mL-1 with a LOD (limit of detection) of 2 cfu mL-1. SIGNIFICANCE: The novel dual-functional HCR-multiApt presents a simple and powerful strategy for improving the aptamer binding affinity toward Salmonella. Simultaneously, integrating this dual-functional HCR-multiApt with the CRISPR/Cas12a system significantly enhances the sensitivity by cascade signal amplification in a nucleic acids amplification-free way. Finally, leveraging the versatility of the aptamer, this highly sensitive method can be further extended for application in the detection of other bacteria, food safety monitoring, or clinical diagnostics.

Simultaneous bright- and dark-field X-ray microscopy at X-ray free electron lasers.

The structures, strain fields, and defect distributions in solid materials underlie the mechanical and physical properties across numerous applications. Many modern microstructural microscopy tools characterize crystal grains, domains and defects required to map lattice distortions or deformation, but are limited to studies of the (near) surface. Generally speaking, such tools cannot probe the structural dynamics in a way that is representative of bulk behavior. Synchrotron X-ray diffraction based imaging has long mapped the deeply embedded structural elements, and with enhanced resolution, dark field X-ray microscopy (DFXM) can now map those features with the requisite nm-resolution. However, these techniques still suffer from the required integration times due to limitations from the source and optics. This work extends DFXM to X-ray free electron lasers, showing how the [Formula: see text] photons per pulse available at these sources offer structural characterization down to 100 fs resolution (orders of magnitude faster than current synchrotron images). We introduce the XFEL DFXM setup with simultaneous bright field microscopy to probe density changes within the same volume. This work presents a comprehensive guide to the multi-modal ultrafast high-resolution X-ray microscope that we constructed and tested at two XFELs, and shows initial data demonstrating two timing strategies to study associated reversible or irreversible lattice dynamics.

A Colorimetric/Fluorescent Dual-Mode Aptasensor for Salmonella Based on the Magnetic Separation of Aptamers and a DNA-Nanotriangle Programmed Multivalent Aptamer.

Salmonella infection has emerged as a global health threat, causing death, disability, and socioeconomic disruption worldwide. The rapid and sensitive detection of Salmonella is of great significance in guaranteeing food safety. Herein, we developed a colorimetric/fluorescent dual-mode method based on a DNA-nanotriangle programmed multivalent aptamer for the sensitive detection of Salmonella. In this system, aptamers are precisely controlled and assembled on a DNA nanotriangle structure to fabricate a multivalent aptamer (NTri-Multi-Apt) with enhanced binding affinity and specificity toward Salmonella. The NTri-Multi-Apt was designed to carry many streptavidin-HRPs for colorimetric read-outs and a large load of Sybr green I in the dsDNA scaffold for the output of a fluorescent signal. Therefore, combined with the magnetic separation of aptamers and the prefabricated NTri-Multi-Apt, the dual-mode approach achieved simple and sensitive detection, with LODs of 316 and 60 CFU/mL for colorimetric and fluorescent detection, respectively. Notably, the fluorescent mode provided a self-calibrated and fivefold-improved sensitivity over colorimetric detection. Systematic results also revealed that the proposed dual-mode method exhibited high specificity and applicability for milk, egg white, and chicken meat samples, serving as a promising tool for real bacterial sample testing. As a result, the innovative dual-mode detection method showed new insights for the detection of other pathogens.

Pressure-Modulated Anomalous Organic-Inorganic Interactions Enhance Structural Distortion and Second-Harmonic Generation in MHyPbBr3 Perovskite.

Organic-inorganic halide perovskites possess unique electronic configurations and high structural tunability, rendering them promising for photovoltaic and optoelectronic applications. Despite significant progress in optimizing the structural characteristics of the organic cations and inorganic framework, the role of organic-inorganic interactions in determining the structural and optical properties has long been underappreciated and remains unclear. Here, by employing pressure tuning, we realize continuous regulation of organic-inorganic interactions in a lead halide perovskite, MHyPbBr3 (MHy+ = methylhydrazinium, CH3NH2NH2+). Compression enhances the organic-inorganic interactions by strengthening the Pb-N coordinate bonding and N-H···Br hydrogen bonding, which results in a higher structural distortion in the inorganic framework. Consequently, the second-harmonic-generation (SHG) intensity experiences an 18-fold increase at 1.5 GPa, and the order-disorder phase transition temperature of MHyPbBr3 increases from 408 K under ambient pressure to 454 K at the industrially achievable level of 0.5 GPa. Further compression triggers a sudden non-centrosymmetric to centrosymmetric phase transition, accompanied by an anomalous bandgap increase by 0.44 eV, which stands as the largest boost in all known halide perovskites. Our findings shed light on the intricate correlations among organic-inorganic interactions, octahedral distortion, and SHG properties and, more broadly, provide valuable insights into structural design and property optimization through cation engineering of halide perovskites.

Comparative investigation of various modification methods on Trachypenaeus Curvirostris surimi gel: Gelling properties, rheological behaviors and structure characteristics.

The aim of this study was to compare the investigations of various contents of egg white protein (2.0%-8.0%, EWP), microbial transglutaminase (0.1%-0.4%, MTGase), and konjac glucomannan (0.5%-2.0%, KGM) on the gelling properties and rheological behavior of Trachypenaeus Curvirostris shrimp surimi gel (SSG), and assessed the modification mechanisms through the analysis of structure characteristics. The findings suggested that all modified SSG samples (expect SSG-KGM2.0% ) had the higher gelling properties and the denser network structure than those of unmodified SSG. Meanwhile, EWP could give SSG a better appearance than MTGase and KGM. Rheological results showed that SSG-EWP6% and SSG-KGM1.0% had the highest G' and G″, demonstrating that the formation of higher levels of elasticity and hardness. All modifications could increase gelation rates of SSG along with the reduction of G″ during the degeneration of protein. According to the FTIR results, three modification methods changed SSG protein conformation with the increasing α-helix and ß-sheet contents and the decreasing of random coil content. LF-NMR results indicated that more free water could be transformed into immobilized water in the modified SSG gels, which contributed to improve the gelling properties. Furthermore, molecular forces showed that EWP and KGM could further increase the hydrogen bonds and hydrophobic interaction in SSG gels, while MTGase could induce the formation of more disulfide bonds. Thus, compared with another two modifications, EWP modified SSG gels showed the highest gelling properties.

Anomalous Charge Transfer from Organic Ligands to Metal Halides in Zero-Dimensional [(C6 H5 )4 P]2 SbCl5 Enabled by Pressure-Induced Lone Pair-π Interaction.

Low-dimensional (low-D) organic metal halide hybrids (OMHHs) have emerged as fascinating candidates for optoelectronics due to their integrated properties from both organic and inorganic components. However, for most of low-D OMHHs, especially the zero-D (0D) compounds, the inferior electronic coupling between organic ligands and inorganic metal halides prevents efficient charge transfer at the hybrid interfaces and thus limits their further tunability of optical and electronic properties. Here, using pressure to regulate the interfacial interactions, efficient charge transfer from organic ligands to metal halides is achieved, which leads to a near-unity photoluminescence quantum yield (PLQY) at around 6.0 GPa in a 0D OMHH, [(C6 H5 )4 P]2 SbCl5 . In situ experimental characterizations and theoretical simulations reveal that the pressure-induced electronic coupling between the lone-pair electrons of Sb3+ and the π electrons of benzene ring (lp-π interaction) serves as an unexpected "bridge" for the charge transfer. Our work opens a versatile strategy for the new materials design by manipulating the lp-π interactions in organic-inorganic hybrid systems.