Evaluation and driving force analysis of ecological environment in low mountain and hilly regions based on optimized ecological index.

In low mountain and hilly regions, vegetation cover is higher and plant growth has an accumulative effect, sequestering carbon more strongly. The traditional remote sensing based ecological index (RSEI) lacks the consideration of vegetation productivity, and using it to evaluate ecological environment in low mountain and hilly regions will be biased. In this study, the vegetation productivity was introduced to construct a natural remote sensing based ecological index (NRSEI) that responds to the low mountain and hilly regions, as an example of Gaizhou City, China. Additionally, this study explored the spatiotemporal evolution of ecological environment quality from 2014 to 2020 and quantified the influences of factors. The results show that the first principal component (PC1) increased from 56 to 67% to 65-87% and considered the accumulation process in the ecosystem. NRSEI was more valid. From 2014 to 2020, the quality of the ecological environment generally declined and then increased. The area with "Excellent" increased from 23 to 38%. The quality of ecosystems in the west, northwest, and south deteriorated significantly, a distribution pattern of "high in the center, low in the north and south". Landuse and topographic conditions dominate the impacts on the ecosystem in the context of social, economic and policy influences. The interactions of the factors were two-factor enhancement that together affect the ecological environment. The results contribute to the development of urban conservation policies in low mountain and hilly regions.

Research on adaptive hydraulic drive optimization control of concrete mixing tank truck for open-pit mine.

The non-axisymmetric problem caused by the fluid sloshing in the tank of a mining concrete mixing tank truck during driving is affected by the excitation of complex road surfaces. The fluid sloshing is coupled with the dynamics of the vehicle body due to the excitation of the complex road surface. The traditional hydraulic drive proportional integral differential (PID) control method is not effective in dealing with such problems, which can easily lead to accidents such as overturning. To improve the accuracy and stability of the hydraulic drive control system, this paper proposes an optimized particle filter PID adaptive control method based on the elastic firefly (FA) algorithm to accelerate the convergence speed of control parameter optimization, and then analyzes its hydraulic drive control characteristics and structural applications, and discusses step steering and double lane change modes are simulated under filling rates of 1.5 and 2.0, respectively. The experimental results show that compared with traditional PID control, the proposed adaptive control method can significantly reduce the average speed error of hydraulic drive control to 0.03km/h and the maximum speed error to 0.17km/h. It also improves the control tracking performance and stability. The practicality of the adaptive hydraulic drive is verified in the filling rate experiments under step steering and double-lane shifting conditions. It has important reference value for the practical application of hydraulic drive control optimization of mining concrete mixing transport tank trucks.

Single-Step PECVD Synthesis of Graphene@Carbon Nanotubes Electrocatalyst.

Graphene (Gr) and carbon nanotubes (CNTs), the two intriguing carbon nanomaterials, have presented great potential in serving as high-performance electrocatalysts in lithium-sulfur (Li-S) chemistry. The concurrent management of both materials would achieve a promoted synergistic effect. Nevertheless, there still remains a lack of an effective material synthesis route. Herein, a single-step plasma-enhanced chemical vapor deposition (PECVD) strategy is devised to prepare Gr@CNTs heterostructures with strong bonded connections. In the PECVD system, the damaged sidewalls generated in CNT tubes can serve as appropriate nucleation sites for further Gr growth. The formation mechanisms are thoroughly explored in aspects of both experimental characterizations and theoretical calculations. To confirm the validity of this approach, thus-constructed Gr@CNTs architectures are employed as the sulfur host, enabling boosted redox kinetics of polysulfides. This project provides fundamental insight into the mechanism exploration for single-step PECVD growth of Gr@CNTs heterostructure, hence promoting the practical application prospect of carbon nanomaterials toward Li-S systems.

Long-Term Neurotoxic Effects and Alzheimer's Disease Risk of Early EHDPP Exposure in Zebrafish: Insights from Molecular Mechanisms to Adult Pathology.

2-Ethylhexyl diphenyl phosphate (EHDPP), ubiquitously monitored in environmental media, is highly bioaccumulative and may pose long-term risks, even after short-term exposure. In this investigation, larval zebrafish were exposed to 0.05, 0.5, and 5.0 µg/L EHDPP from 4 to 120 h postfertilization (hpf) to examine the long-term neurotoxicity effects of early exposure. Exposure to 5.0 µg/L EHDPP yielded hyperactive locomotor behavior, which was characterized by increased swimming speed, larger turning angles, and heightened sensitivity to light-dark stimulation. The predicted targets of EHDPP (top 100 potential macromolecules) were primarily associated with brain diseases like Alzheimer's disease (AD). Comparisons of differentially expressed genes (DEGs) from AD patients (GSE48350) and RNA-seq data from EHDPP-exposed zebrafish confirmed consistently abnormal regulatory pathways. EHDPP's interaction with M1 and M5 muscarinic acetylcholine receptors likely disrupted calcium homeostasis, leading to mitochondrial dysfunction and neurotransmitter imbalance as well as abnormal locomotor behavior. Especially, 5.0 µg/L EHDPP exposure during early development (4-120 hpf) triggered early- and midstage AD-like symptoms in adulthood (180 dpf), characterized by cognitive confusion, aggression, blood-brain barrier disruption, and mitochondrial damage in brains. These findings provide deep insights into the long-term neurotoxicity effects and Alzheimer's disease risks of early EHDPP exposure at extremely low dosages.

Scalable Synthesis of Organic Core/Shell Architectures toward Dual-Wavelength Optical Waveguides.

Organic core/shell heterostructures have undergone rapid progress in materials chemistry owing to the integration of a wide array of unique properties. Nonetheless, the intricate challenge of regulating homogeneous nucleation and phase separation processes in excessively analogous cocrystal structures presents a formidable barrier to expanding the synthesis strategy for organic core/shell heterostructures. Herein, we successfully achieved a phase separation growth process facilitated by the organic alloy interface layer through a dynamic visualization to capture the intricate morphological evolution. By finely regulating the nucleation process, homogeneous self-assembly induced by high chemical and structural compatibility is circumvented, enabling the formation of organic core/shell heterostructures. Notably, this core/shell architecture boasts dual-wavelength emission at 496 and 696 nm, accompanied by an optical loss coefficient of 0.092 dB per micrometer. This methodology shows potential for extending to the scalable design of other conformational cocrystal heterostructure systems, thereby offering valuable insights into the realm of organic photonics.

Abnormal Dynamic Reconfiguration of Multilayer Temporal Networks in Patients with Bipolar Disorder.

BACKGROUND: Multilayer networks have been used to identify abnormal dynamic reconfiguration in bipolar disorder (BD). However, these studies ignore the differences in information interactions between adjacent layers when constructing multilayer networks, and the analysis of dynamic reconfiguration is not comprehensive enough; Methods: Resting-state functional magnetic resonance imaging data were collected from 46 BD patients and 54 normal controls. A multilayer temporal network was constructed for each subject, and inter-layer coupling of different nodes was considered using network similarity. The promiscuity, recruitment, and integration coefficients were calculated to quantify the different dynamic reconfigurations between the two groups; Results: The global inter-layer coupling, recruitment, and integration coefficients were significantly lower in BD patients. These results were further observed in the attention network and the limbic/paralimbic and subcortical network, reflecting reduced temporal stability, intra- and inter-subnetwork communication abilities in BD patients. The whole-brain promiscuity was increased in BD patients. The same results were observed in the somatosensory/motor and auditory network, reflecting more functional interactions; Conclusions: This study discovered abnormal dynamic interactions of BD from the perspective of dynamic reconfiguration, which can help to understand the pathological mechanisms of BD.

Epitaxial Growth of Two-Dimensional Organic Crystals with In-Plane Heterostructured Domain Regulation.

Complex organic lateral heterostructures (OLHs) with spatial distribution of two or more chemical components are crucial for designing and realizing unique structure-dependent optoelectronic applications. However, the precise design of well-defined OLHs with flexible domain regulation remains a considerable challenge. Herein, we present a stepwise solution self-assembly method to synthesize two-dimensional (2D) OLHs with a central rhombus domain and a lateral region featuring tunable blue and green emission based on the sequential nucleation and growth of 2D crystals. By controlling the initial crystallization time of 2,6-diphenylanthracene, the rhombic length ratio (α) of the multicolor-emissive part of the 2D OLHs is precisely modified. Furthermore, a third lateral layer is constructed on the resulting OLHs, demonstrating scalable lateral regulation. Significantly, these prepared 2D OLHs exhibit great excitation position-dependent waveguide characteristics and enable a 0.06 dB/µm low-loss waveguiding, which are conducive to photon transport and conversion for photonic integrated circuits. This work provides a stepwise strategy for the accurate fabrication of 2D OLHs, fabricating the developments of next-generation optoelectronics devices.

Effect of tumor-derived extracellular vesicle-shuttled lncRNA MALAT1 on proliferation, invasion and metastasis of triple-negative breast cancer by regulating macrophage M2 polarization via the POSTN/Hippo/YAP axis.

OBJECTIVES: Triple-negative breast cancer (TNBC) is the deadliest subtype of breast cancer (BC). Tumor-derived extracellular vesicles (EVs) trigger tumor progression by promoting M2 polarization. Some lncRNAs can be encapsulated into EVs for intercellular communication. Herein, we investigated the mechanism of TNBC-derived EV-shuttled lncRNA MALAT1 on macrophage polarization/tumorigenesis. METHODS: BC-associated targeted EV-derived lncRNAs were screened. Tumor tissues/tissues adjacent to cancer of TNBC patients, and blood samples of all subjects were collected. MALAT1/POSTN mRNA levels in tumor tissues/tissues adjacent to cancer, and MALAT1 expression in EVs and its correlation with TNBC patient overall survival were assessed by RT-qPCR/Kaplan-Meier survival analysis/log-rank test. TNBC patient M2 infiltration was detected by flow cytometry. MALAT1/POSTN levels in EVs/macrophages were regulated by transfection. Hippo/YAP activation was determined by Western blot. Nude mouse xenograft model was established and metastasis was detected by H&E staining. RESULTS: MALAT1/POSTN were up-regulated and correlated with M2 infiltration/poor prognosis in TNBC patients. TNBC-derived EVs induced M2 polarization. MALAT1 was highly expressed in TNBC-derived EVs and could be transferred to macrophages via EVs to induce M2 polarization. POSTN overexpression diminished the inhibitory effect of MALAT1 knockdown on M2 markers. EVs activated the Hippo/YAP pathway in macrophages. The Hippo/YAP pathway inhibition abrogated the effect of POSTN overexpression on M2 marker expression. TNBC-EV-derived MALAT1 facilitated M2 polarization, and thus promoting occurrence and metastasis of TNBC in vitro and in vivo. CONCLUSIONS: TNBC-EV-derived MALAT1 activated the Hippo/YAP axis by up-regulating POSTN, thereby inducing M2 polarization to promote TNBC occurrence and metastasis in vivo.

Directional self-assembly of organic vertically superposed nanowires.

Organic crystal-based superimposed heterostructures with inherent multichannel characteristics demonstrate superior potential for manipulating excitons/photons at the micro/nanoscale for integrated optoelectronics. However, the precise construction of organic superimposed heterostructures with fixed superimposed sites remains challenging because of the random molecular nucleation process. Here, organic vertically superimposed heterostructures (OSHs) with fixed superimposed positions are constructed via semi-wrapped core/shell heterostructures with partially exposed cores, which provide preferential nucleation sites for further molecular epitaxial growth processes. Furthermore, the relative length ratio from 21.7% to 95.3% between interlayers is accurately adjusted by regulating the exposed area of the semi-wrapped core/shell heterostructures. Significantly, these OSHs with anisotropic optical characteristics demonstrate well regulation of excitation position-dependent waveguide behaviors and can function as photonic barcodes for information encryption. This strategy provides a facile approach for controlling the nucleation sites for the controllable preparation of organic heterostructures and advanced applications for integrated optoelectronics.

Orbital Adipose Tissue: The Optimal Control for Back-Table Fluorescence Imaging of Orbital Tumors.

Control tissue is essential for ensuring the precision of semiquantitative analysis in back-table fluorescence imaging. However, there remains a lack of agreement on the appropriate selection of control tissues. To evaluate the back-table fluorescence imaging performance of different normal tissues and identify the optimal normal tissue, a cohort of 39 patients with orbital tumors were enrolled in the study. Prior to surgery, these patients received indocyanine green (ICG) and following resection, 43 normal control tissues (34 adipose tissues, 3 skin tissues, 3 periosteal tissues, and 3 muscle tissues) were examined using back-table fluorescence imaging. The skin tissue demonstrated significantly elevated fluorescence intensity in comparison to the diseased tissue, whereas the muscle tissue exhibited a broad range and standard deviation of fluorescence signal intensity. Conversely, the adipose and periosteum displayed weak fluorescence signals with a relatively consistent distribution. Additionally, no significant correlations were found between the signal-to-background ratio (SBR) of adipose tissue and patients' ages, genders, weights, disease duration, tumor origins, dosing of administration of ICG infusion, and the time interval between ICG infusion and surgery. However, a positive correlation was observed between the SBR of adipose tissue and its size, with larger adipose tissues (>1 cm) showing an average SBR 27% higher than smaller adipose tissues (≤1 cm). In conclusion, the findings of this study demonstrated that adipose tissue consistently exhibited homogeneous hypofluorescence during back-table fluorescence imaging, regardless of patient clinical variables or imaging parameters. The size of the adipose tissue was identified as the primary factor influencing its fluorescence imaging characteristics, supporting its utility as an ideal control tissue for back-table fluorescence imaging.

The impact of indirect structure on functional connectivity in schizophrenia using a multiplex brain network.

It is known that abnormal functional connectivity (FC) in schizophrenia (SZ) is closely related to structural connectivity (SC). We speculate that indirect SC also have an impact on FC in SZ patients. Conventional single-layer network has limitations for studying the relationship between indirect SC and FC. Thus, this study constructed a multiplex network based on structural connectivity and functional connectivity (SC-FC). The SC-FC bandwidth and SC-FC cost are used to analyze the impact of indirect SC on FC. Moreover, this paper proposed mediation ability, mediation cost, mediated strength and mediated cost to quantify the effects of mediator nodes and mediated nodes on indirect SC. The results show that SZ patients exhibit lower SC-FC bandwidth and SC-FC cost compared to healthy controls (HC), which could be caused by the limbic and subcortical network (LSN), default mode network (DMN) and visual network (VN). The mediator and mediated nodes in indirect SC of SZ patients also showed diminished effects. These findings suggest that functional communication ability and cost in SZ patients are influenced by indirect SC. This study provides new perspectives for understanding the relationship between indirect SC and FC, and provides strong evidence for interpreting the physiological mechanisms of SZ patients.

Lauric acid improved the quality of fresh noodles with/without sodium bicarbonate by altering physical properties and structure of wheat starch.

To know the influence of lauric acid (LA) on wheat flour fresh noodles (WFN) quality and the latent mechanism, the effect of LA on cooking properties, digestibility and structure of WFN with/without sodium bicarbonate (SB) and the properties of wheat flour (WF) with/without SB were studied. The results indicated that LA reduced cooking loss and digestibility of WFN with SB and slightly decreased water adsorption and increased the free water binding ability and hardness of WFN without SB. Furthermore, LA increased the degree of short- and long-range order and molecular weight of starch in cooked WFN with/without SB and it had greater effect on the degree of short- and long-range order and molecular weight of starch in cooked WFN with SB than that without SB. Differential scanning calorimeter (DSC) and rapid viscosity analysis (RVA) displayed that WFN with LA and SB formed more starch-LA or/and starch-LA-protein complexes than WFN with LA. Additionally, the impact of LA on WFN quality and WF properties was influenced by SB concentration. This study will provide theoretical basis and new thoughts for the design of high-quality fresh noodles with low digestibility, low cooking loss and high hardness.

Insight into the effect of potassium carbonate on the physicochemical and structural properties of starch isolated from hot-dry noodles.

The objective of this study was to investigate the changes in physicochemical and structural properties of starch isolated from hot-dry noodles (HDNS) treated with different contents of potassium carbonate (K2CO3). The results demonstrated that the existence of K2CO3 increased the WHC and hardness of HDNS gel with an elevated storage modulus. Meanwhile, K2CO3 promoted the gelatinization of HDNS, which displayed higher viscosity and swelling power. Moreover, the relative crystallinity of HDNS were improved. K2CO3 facilitated the transformation of HDNS from an amorphous to a more ordered and crystalline structure. Simultaneously, the microscopic characteristics exhibited that K2CO3 promoted the partial fusion of starch particles to form aggregates, and the particle size became larger. In conclusion, the physicochemical and structural properties of HDNS were improved effectively with the incorporation of K2CO3, and the research results provided new insights for the processing of high-quality hot-dry noodles.

N6-methyladenosine modification of linc-OIP5 confers paclitaxel resistance in breast cancer through a DDX5-dependent mechanism.

Chemoresistance is a significant obstacle in the treatment of breast cancer (BC). Due to its diverse composition, the causes of chemoresistance in BC are complex and have not been completely understood. In this article, we explored the mechanism of N6-methyladenosine (m6A)-modified long intervening noncoding RNA (linc)-OIP5 in BC chemoresistance. We successfully constructed drug-resistant cell lines MCF-7/P and MDA-MB-231/P by exposing parental MDA-MB-231 and MCF-7 cells to escalating doses of paclitaxel (PTX) and revealed multiple m6A methylation modification sites on linc-OIP5 according to the predictive analysis of the SRAMP database. Linc-OIP5 expression and m6A modification were up-regulated in PTX-resistant BC cells. Inhibition of m6A modification or linc-OIP5 knockdown facilitated PTX-resistant and parental BC cell apoptosis and repressed proliferation and migration. Mechanistically, linc-OIP5 bound to TRIM5 and reduced the ubiquitination of DDX5, thus stabilizing the DDX5 protein. Additionally, DDX5 overexpression partly abrogated the suppressing effects of inhibited m6A modification or si-linc-OIP5 on cell proliferation, migration and PTX resistance. These findings indicate that m6A-modified linc-OIP5 reduced DDX5 ubiquitination and enhanced DDX5 stability by binding to TRIM5, thereby promoting BC cell proliferation, migration and PTX resistance, and inhibiting apoptosis.

Programmable In-Situ Co-Assembly of Organic Multi-Block Nanowires for Cascade Optical Waveguides.

Organic heterostructures (OHs) with multi-segments exhibit special optoelectronic properties compared with monomeric structures. Nevertheless, the synthesis of multi-block heterostructures remains challenging due to compatibility issues between segment parts, which restricts their application in optical waveguides and integrated optics. Herein, we demonstrate programmable in-situ co-assembly engineering, combining multi-step spontaneous self-assembly processes to promote the synthesis of multi-block heterostructures with a rational arrangement of three or more segments. The rational design of segments enables exciton manipulation and ensures optical waveguides and proper output among the multi-segment OHs. This work enables the controllable growth of segments within multi-block OHs, providing a pathway to construct complex OHs for the rational development of future optical applications.

Application of a cloud platform that identifies patient-ventilator asynchrony and enables continuous monitoring of mechanical ventilation in intensive care unit.

Background: Patient-ventilator asynchrony (PVA) frequently occurs in mechanically ventilated patients within the ICU and has the potential for harm. Depending solely on the health care team cannot accurately and promptly identify PVA. To address this issue, our team has developed a cloud-based platform for monitoring mechanical ventilation (MV), comprising the PVA-RemoteMonitor system and the 24-h MV analysis report. We conducted a survey to evaluate physicians' satisfaction and acceptance of the platform in 14 ICUs. Methods: Data from medical records, clinical information systems, and ventilators were uploaded to the cloud platform and underwent data processing. The data were analyzed to monitor PVA and displayed in the front-end. The 24-h analysis report for MV was generated for clinical reference. Critical care physicians in 14 hospitals' ICUs that involved in the platform participated in a questionnaire survey, among whom 10 physicians were interviewed to investigate physicians' acceptance and opinions of this system. Results: The PVA-RemoteMonitor system exhibited a high level of specificity in detecting flow insufficiency, premature cycle, delayed cycle, reverse trigger, auto trigger, and overshoot, with sensitivities of 90.31 %, 98.76 %, 99.75 %, 99.97 %, 100 %, and 99.69 %, respectively. The 24-h analysis report supplied essential data about PVA and respiratory mechanics. 86.2 % (75/87) of physicians supported the application of this platform. Conclusions: The PVA-RemoteMonitor system accurately identified PVA, and the MV analysis report provided guidance in controlling PVA. Our platform can effectively assist ICU physicians in the management of ventilated patients.

Water retention property and microscopic mechanism of shallow soil in inner dump improved by fly ash and polyacrylamide.

Improving the water retention property of shallow soil in the inner dump is the key step in the sustainable development of mines. In recent years, the use of fly ash to improve the structure of the inner dump and polyacrylamide as an additive to enhance water retention was an effective method. The article used a physical model test, filter paper method, and microstructure analysis method to compare and analyze the water retention property and microstructure of slope-improved soil with different fly ash and polyacrylamide content. The results show that the combined use of fly ash and polyacrylamide improved the water retention property of the amended soil. Fly ash and polyacrylamide had a greater effect on the low suction stage of the amended soil. Polyacrylamide reacted with water and bound soil particles to form aggregates, and the structural unit bodies were a block structure. Fly ash was non-sticky and was a matrix of fine particles, which weakened the bonding effect of polyacrylamide, and reduced the aggregates of soil particles, and the structural unit bodies were a flocculated structure of aggregates mixed with matrix. This, in turn, enhanced the capillary action and improved the water retention performance of the improved soil. In addition, polyacrylamide could connect water molecules, further enhancing the water retention property of the improved soil. The combined use of fly ash and polyacrylamide improved the available water content of improved soil, providing a viable and sustainable solution for improving the comprehensive utilization of fly ash, and laid the foundation for land reclamation at the inner dump.

Superior oxidase-mimetic activity of FeCo-NC dual-atom nanozyme for smartphone-based visually colorimetric assay of organophosphorus pesticides.

A colorimetric analysis platform has been successfully developed based on FeCo-NC dual-atom nanozyme (FeCo-NC DAzyme) for the detection of organophosphorus pesticides (OPPs). The FeCo-NC DAzyme exhibited exceptional oxidase-like activity (OXD), enabling the catalysis of colorless TMB to form blue oxidized TMB (oxTMB) without the need for H2O2 involvement. By combining acid phosphatase (ACP) hydrolase with FeCo-NC DAzyme, a "FeCo-NC DAzyme + TMB + ACP + SAP" colorimetric system was constructed, which facilitated the rapid detection of malathion. The chromogenic system was applied to detect malathion using a smartphone-based app and an auxiliary imaging interferogram device for colorimetric measurements, which have a linear range of 0.05-4.0 µM and a limit of detection (LOD) as low as 15 nM in real samples, comparable to UV-Vis and HPLC-DAD detection methods. Overall, these findings present a novel approach for convenient, rapid, and on-site monitoring of OPPs.

Integration of Myrica rubra-based N-doped carbon dots with Fe3S4 as excellent peroxidase mimics for colorimetric assay and smartphone-based intelligent sensing of p-aminophenol in waters.

To realize the reutilization of waste Myrica rubra in the analytical field, we synthesized Myrica rubra-based N-doped carbon dots (MN-CDs) and further anchored them onto the surface of Fe3S4 to fabricate Fe3S4@MN-CD nanocomposites. The as-fabricated nanocomposites possessed higher peroxidase-mimetic activity than its two precursors, resulting from the synergistic effect between them, and could catalyze colorless 3,3',5,5'-tetramethylbenzidine (TMB) into deep blue oxTMB with a strong 652-nm absorption. Under optimized conditions (initial solution pH, 3.5; incubation temperature, 35 ℃; Fe3S4@MN-CD concentration, 50 µg mL-1, and 652-nm absorption), Fe3S4@MN-CDs were employed for colorimetric assay of p-aminophenol (p-AP) with wide linear range (LR, 2.9-100 µM), low detection limit (LOD, 0.87 µM), and satisfactory recoveries (86.3-105%) in environmental waters. Encouragingly, this colorimetric assay provided the relative accuracy of 97.0-99.4% as compared with  conventional HPLC-UV detection. A portable smartphone-based colorimetric application was developed by combining the Fe3S4@MN-CD-based visually chromogenic reaction with a "Thing Identify" APP software. Besides, we engineered an image-capturing device feasible for field use, in which the internal-compact sealing prevented external light source from entering photography chamber, thereby reducing light interference, and also the bottom light source enhanced the intensity of blue imaging. This colorimetric platform exhibited satisfactory LR (1-500 µM), low LOD (0.3 µM), and fortification recoveries (86.6-99.6%). In the chromogenic reaction catalyzed by Fe3S4@MN-CDs, ·O2- played a key role in concomitant with the participation of •OH and h+. Both the colorimetric assay and smartphone-based intelligent sensing show great promising in on-site monitoring of p-AP under field conditions.

Effect of oxidized starch on the storage stability of frozen raw noodles: Water distribution, protein structure, and quality attributes.

Freezing is a popular method of food preservation with multiple advantages. However, it may change the internal composition and quality of food. This study aimed to investigate the effect of modified starch on the storage stability of frozen raw noodles (FRNs) under refrigerated storage conditions. Oxidized starch (OS), a modified starch, is widely used in the food industry. In the present study, texture and cooking loss rate analyses showed that the hardness and chewiness of FRNs with added OS increased and the cooking loss rate decreased during the frozen storage process. Low-field nuclear magnetic resonance characterization confirmed that the water-holding capacity of FRNs with OS was enhanced. When 6% OS was added, the maximum freezable water content of FRNs was lower than the minimum freezable water content (51%) of FRNs without OS during freezing. Fourier-transform infrared spectroscopy showed that after the addition of OS, the secondary structures beneficial for structural maintenance were increased, forming a denser protein network and improving the microstructure of FRNs. In summary, the water state, protein structure, and quality characteristics of FRNs were improved by the addition of OS within an appropriate range.