Search Results (88)

Osteoporosis is highly prevalent in postmenopausal women, causing chronic pain, fractures, and limited mobility that burden individuals and society. While resistance exercise benefits bone health, its role in osteoporotic bone injury healing and underlying mechanisms remain unclear. This study aimed to explore the effects of 10-week weight-bearing ladder climbing exercise on ovariectomy (OVX)-induced osteoporosis and subsequent bone injury healing, and to investigate whether these effects are associated with the myostatin (MSTN) and Wnt/β-catenin pathways. Fifty-four 12-week-old female SD rats were randomized into Sham, OVX, and OVX + EX groups. Rats in the OVX and OVX + EX groups underwent ovariectomy to induce postmenopausal osteoporosis, and those in the OVX + EX group received 10-week weight-bearing ladder climbing. After the exercise intervention, 6 rats in each group were sacrificed; the remaining rats underwent femoral midshaft drilling to establish bone injury. The improvement in osteoporosis was evaluated via Micro-CT, biomechanical tests, RT-qPCR for mRNA detection, and Western blot for measuring protein levels of MSTN and Wnt/β-catenin pathway-related molecules at post-exercise and 21 days post-injury. Bone healing was reflected by the bone volume fraction at the bone injury site detected via Micro-CT at 10 and 21 days post-injury. This exercise significantly enhanced muscle strength and improved femoral bone mineral density (BMD), trabecular microstructure, and biomechanical properties in OVX rats. Meanwhile, the level of MSTN in the OVX + EX group was decreased, the expression of its downstream signaling pathways was inhibited, and the mRNA and protein expressions of Wnt/β-catenin were upregulated. Moreover, 21 days after exercise intervention, the biomechanical properties and bone microstructure of the OVX + EX group were still significantly superior to those of the OVX group, and the aforementioned molecular regulatory effect remained. In addition, pre-conducted exercise was able to promote increases in bone volume fraction at the bone injury site 10 and 21 days after drilling, which was conducive to bone injury healing. Ten-week weight-bearing ladder climbing ameliorates OVX-induced bone loss and promotes osteoporotic bone repair via regulating the MSTN/ActRIIB/Smad3 and Wnt/β-catenin pathways, providing evidence for exercise as a safe non-pharmacological intervention. Full article

Freezing is a common food preservation method, but conventional freezing often produces large, irregular ice crystals that damage muscle tissue and degrade food quality. This study developed an experimental system using an impact freezer to investigate the effects of alternating magnetic fields (AMFs) of different intensities (0 G, 20 G, 40 G, 60 G, and 80 G) and frequencies (50 Hz, 100 Hz, 150 Hz, 200 Hz, and 250 Hz) on the freezing behavior and muscle quality of Penaeus Japonicus. Results showed that applying a 40 G AMF (AMF-40) significantly reduced freezing time, thawing loss, and cooking loss. It also improved water retention, texture, and color stability. Water distribution analysis indicated that AMF-40 limited the movement and loss of immobilized and free water. Microstructural observations revealed smaller pores and more intact muscle fibers, suggesting the formation of finer ice crystals. Under a 200 Hz AMF (AMF-200 Hz), samples exhibited further decreases in freezing time, thawing loss, and cooking loss, along with significant improvements in hardness, and Springiness, while maintaining muscle color. Enhanced water-holding capacity was also observed, preserving bound water content. Overall, both AMF-40 and AMF-200 Hz promoted the formation of smaller ice crystals and effectively preserved the muscle quality of Penaeus Japonicus during freezing, improving the preservation outcome. Full article

With the advancement of crewed spaceflight, mitigating the physiological effects of microgravity, such as bone–muscle deterioration and movement instability, has become increasingly vital. Inspired by reptilian climbing mechanisms, this study presents a novel bio-inspired adhesive footwear characterized by low pre-load, strong adhesion, and controllable attachment–detachment capability. This study analyzes the adaptability of a multi-level variable modulus design to surfaces with varying curvatures and roughness. Experimental investigations were conducted to analyze the contact mechanics and interfacial mechanisms of biomimetic adhesive materials featuring microstructure arrays. Moreover, stepping exercises were performed by volunteers wearing the proposed footwear under simulated weightlessness to assess biomechanical performance. Interface contact stresses were measured using force-sensing array plates, enabling characterization of plantar adhesion under different detachment speeds and angles. Electromyographic signals from lower limb muscle groups during stepping exercises were analyzed to elucidate the mechanical stimulation patterns and effects induced by plantar adhesion forces. Results indicate that plantar adhesion forces ranging between 50 and 105 N effectively stimulate primary flexor muscles, including the biceps femoris and gastrocnemius. This biomimetic solution offers a flexible and convenient approach for stabilizing foot positioning and promoting musculoskeletal engagement in microgravity, improving astronauts’ mobility and operational performance in orbit. Full article

Background: Delayed Onset Muscle Soreness (DOMS) is a transient, exercise-induced condition characterized by muscle pain, stiffness, and functional impairment, particularly following eccentric or high-intensity physical activity. Recent advances in diagnostic imaging, neurophysiology, and therapeutic techniques have led to a reassessment of DOMS pathophysiology and management. Objective: This scoping review aims to critically evaluate non-pharmacological strategies for DOMS management, focusing on clinical studies published between 2020 and 2025. Emphasis is placed on physical, thermal, neurophysiological, and nutritional interventions in athletic populations. Methods: A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science. Included studies were randomized controlled trials, systematic reviews, meta-analyses, and high-quality scoping reviews. Methodological quality was assessed using PEDro, AMSTAR 2, and ROBIS tools. Key outcome measures included pain (VAS), functional recovery (ROM, performance), biochemical markers (CK, IL-6), and neuromuscular activation (iEMG). Results: Twenty-five studies met the inclusion criteria. Emerging strategies such as cryosauna, vibration therapy, percussive massage, and polyphenol supplementation demonstrated significant benefits in reducing DOMS-related symptoms and enhancing recovery. Evidence supports the integration of multimodal, personalized interventions over monotherapies. Imaging techniques (7T MRI, ultrasound) confirmed microstructural muscle changes consistent with DOMS, strengthening diagnostic precision. Conclusions: Non-pharmacological approaches to DOMS have evolved considerably, highlighting the importance of combining mechanical, thermal, and nutritional modalities. Personalized, multimodal recovery strategies appear most effective for symptom relief and performance restoration. Future studies should aim to standardize treatment protocols and outcome measures to improve clinical applicability. Full article

This study investigated quality changes in seaweed–yak patties before and after freeze–thaw by varying seaweed addition levels (10–70%). Macroscopically, the effects on water-holding capacity, textural properties, and oxidative indices of restructured yak patties were evaluated. Microscopically, the impact of seaweed-derived bioactive ingredients on patty microstructure and myofibrillar protein characteristics was examined. LF-NMR and MRI showed that 40% seaweed addition most effectively restricted water migration, reduced thawing loss, and preserved immobilized water content. Texture profile analysis (TPA) revealed that moderate seaweed levels (30–40%) enhanced springiness and minimized post-thaw hardness increases. SEM confirmed that algal polysaccharides formed a denser protective network around the muscle fibers. Lipid oxidation (MDA), free-radical measurements, and non-targeted metabolomics revealed a significant reduction in oxidative damage at 40% seaweed addition, correlating with increased total phenolic content. Protein analyses (particle size, zeta potential, hydrophobicity, and SDS-PAGE) demonstrated a cryoprotective effect of seaweed on myofibrillar proteins, reducing aggregation and denaturation. These findings suggest that approximately 40% seaweed addition can improve the physicochemical stability and antioxidant capacity of frozen seaweed–yak meat products. This work thus identifies the optimal seaweed addition level for enhancing freeze–thaw stability and functional quality, offering practical guidance for the development of healthier, high-value restructured meat products. Full article

Pangasius (Pangasianodon hypophthalmus) minced muscle with 1 and 2% salt was treated with different high-pressure processing and thermal methods, including conventional heat-induced gels (HIGs), high-pressure processing (HPP) prior to cooking (PC), HPP prior to setting (PS), and setting prior to HPP (SP), to evaluate for their effects on the selected physicochemical properties. The results showed that the PC treatment produced gels with a significantly higher gel strength (496.72–501.26 N·mm), hardness (9.62–10.14 N), and water-holding capacity (87.79–89.74%) compared to the HIG treatment, which showed a gel strength of 391.24 N·mm, a hardness of 7.36 N, and a water-holding capacity of 77.98%. PC gels also exhibited the typical microstructure of pressure-induced gels, with a denser and homogeneous microstructure compared to the rough and loosely connected structure of HIGs. In contrast, SP treatment exhibited the poorest gel quality in all parameters, with gel strength ranging from 319.79 to 338.34 N·mm, hardness from 5.87 to 6.31 N, and WHC from 71.91 to 73.72%. Meanwhile, the PS treatment showed a comparable gel quality to HIGs. SDS-PAGE analysis revealed protein degradation and aggregation in HPP-treated samples, with a decrease in the intensity of myosin heavy chains and actin bands. Fourier-transform infrared spectroscopy (FTIR) analysis showed minor shifts in protein secondary structures, with the PC treatment showing a significant increase in α-helices (28.09 ± 0.51%) and a decrease in random coil content (6.69 ± 0.92%) compared to α-helices (23.61 ± 0.83) and random coil structures (9.47 ± 1.48) in HIGs (p < 0.05). Only the PC treatment resulted in a significant reduction in total plate count (TPC) (1.51–1.58 log CFU/g) compared to 2.33 ± 0.33 log CFU/g in the HIG treatment. These findings suggest that HPP should be applied prior to thermal treatments (cooking or setting) to achieve an improved gel quality in reduced-salt pangasius products. Full article

The movement of valves of bivalved invertebrates is enabled through the action of muscles and the interplay between the muscles and the hinge ligament. The muscles that move the valves attach to their internal surface. To promote the structural integrity at the mechanically mismatched interfaces, a specific crystal microstructure and texture are present at the muscle attachment sites. These are different from the crystal microstructure and texture of the rest of the valves. We present here for modern two- and three-layered brachiopod shells (Magellania venosa, Liothyrella neozelanica and Gryphus vitreus) the mode of crystal organisation at sites of adductor and diductor muscle attachments (i) relative to the microstructure and texture that forms the other sections of the valves and (ii) relative to crystal organisation of muscle attachment sites of bivalved invertebrates of other phyla, namely, species of the class Bivalvia. We discuss similarities/differences in Ca-carbonate phase, microstructure and texture between rhynchonellate brachiopods and bivalves, and discuss whether the Ca-carbonate crystal organisation of muscle attachment sites is convergent for bivalved marine organisms. We show significant differences in muscle attachment site architecture and highlight the different structural solutions developed by nature for shells of marine organisms that serve the same purpose. Full article

Plasma-derived fibrin hydrogels are widely used in tissue engineering because of their excellent biological properties. Specifically, human plasma-derived fibrin hydrogels serve as 3D matrices for autologous skin graft production, skeletal muscle repair, and bone regeneration. Nevertheless, for advanced applications such as in vitro skin equivalents and engineered grafts, the intrinsic limitations of native fibrin hydrogels in terms of long-term mechanical stability and resistance to degradation need to be addressed to enhance the usefulness and application of these hydrogels in tissue engineering. In this study, we chemically modified plasma-derived fibrin by incorporating succinimidyl alginate (SA), a version of alginate chemically modified to introduce reactive succinimidyl groups. These NHS ester groups (N-hydroxysuccinimide esters), attached to the alginate backbone, are highly reactive toward the primary amine groups present in plasma proteins such as fibrinogen. When mixed with plasma, the NHS groups covalently bond to the amine groups in fibrin, forming stable amide linkages that reinforce the fibrin network during hydrogel formation. This chemical modification improved mechanical properties, reduces contraction, and enhanced the stability of the resulting hydrogels. Hydrogels were prepared with a final fibrinogen concentration of 1.2 mg/mL and SA concentrations of 0.5, 1, 2, and 3 mg/mL. The objective was to evaluate whether this modification could create a more stable matrix suitable for supporting skin tissue development. The mechanical and microstructure properties of these new hydrogels were evaluated, as were their biocompatibility and potential to create 3D skin models in vitro. Dermo-epidermal skin cultures with primary human fibroblast and keratinocyte cells on these matrices showed improved dermal stability and better tissue structure, particularly SA concentrations of 0.5 and 1 mg/mL, as confirmed by H&E (Hematoxylin and Eosin) staining and immunostaining assays. Overall, these results suggest that SA-functionalized fibrin hydrogels are promising candidates for creating more stable in vitro skin models and engineered skin grafts, as well as for other types of engineered tissues, potentially. Full article

During the processing of marinated braised beef, excessive sodium intake is likely to occur, which can lead to various health issues. Exogenous L-lysine (L-Lys), as an essential amino acid for the human body, has the capability to enhance the quality of low-sodium meat products. This study aimed to investigate the effects of exogenous L-Lys on the quality of low-sodium plain boiled beef and marinated braised beef, as well as its underlying mechanisms of action. Among them, the substitution rate of KCl was 60%. This study was conducted with three batches of experiments, each batch serving as an independent parallel. For low-sodium plain boiled beef, the optimal addition level of L-Lys was screened out through the research on the effects on meat quality indicators, water distribution, microstructure, and sensory evaluation. For the quality of low-sodium plain boiled beef, in terms of microstructure, the addition of L-Lys reduced muscle fiber breakage and voids, thereby improving its microstructural characteristics. Combined with quantitative descriptive analysis (QDA), the optimal level of additional L-Lys was subsequently determined to be 0.6%. It was further processed into marinated braised beef in soy sauce, and a comparative analysis was conducted with low-sodium marinated braised beef in soy sauce without L-Lys addition for shear force, meat color, thiobarbituric acid reactive substances (TBARS), and total viable count (TVC) during the storage periods of 0, 3, 6, 9, and 12 d. The results show that the redness (a*) value significantly increased within 0–12 d (p < 0.05), leading to a more stable meat color. Moreover, the addition of L-Lys significantly reduced the shear force and thiobarbituric acid reactive species (TBARS) values in the marinated braised beef (p < 0.05), thereby optimizing the tenderness of the marinated braised beef and inhibiting lipid oxidation. Although the total viable count (TVC) of the L-Lys group was higher than that of conventional low-sodium marinated braised beef in soy sauce from 9 to 12 d, both groups of products had undergone spoilage by day 12; therefore, the addition of L-Lys had no effect on the shelf life of the products. Comprehensive analysis suggested that the addition of exogenous L-Lys could optimize beef quality by enhancing hydration, improving muscle structural properties, and exerting antioxidant synergistic effects. Full article

Facial wrinkles are a key indicator of aging and hold significant importance in skincare, cosmetics, and cosmetology. Their formation is closely linked to mechanical deformation, yet the underlying processes remain complex. This study integrates the Facial Action Coding System (FACS) with three-dimensional digital image correlation (3D-DIC) to dynamically capture and quantitatively analyze skin deformation during facial expression. Principal strains and their orientation are introduced as important parameters to investigate the relationship between mechanical behavior and wrinkle formation. To further explore these interactions, a four-layer finite element (FE) model incorporating a muscle layer is developed, simulating muscle contraction and its influence on skin deformation. The findings provide a mechanobiological framework for understanding wrinkle formation and may inspire the development of strain-sensitive sensors for real-time detection of microstructural deformations. Full article

In recent years, flexible pressure sensors have attracted significant attention due to their extensive application prospects in wearable devices, healthcare monitoring, and other fields. Herein, we propose a flexible piezoresistive sensor with a broad detection range, utilizing a CNT/PVA composite as the pressure-sensitive layer. The effect of the CNT-to-PVA ratio on sensing performance was systematically investigated, revealing that the sensor’s sensitivity initially increases and then decreases with rising CNT content. When the weight percentage of CNTs reaches 11.24 wt%, the sensing film exhibits optimal piezoresistive properties. A resistance model of the composite conductive material was established to elucidate the sensing mechanism associated with CNT content in detail. Furthermore, hill-like microstructures were fabricated on a PDMS substrate using sandpaper as a template to further enhance overall performance. The sensor demonstrates a sensitivity of 0.1377 kPa⁻¹ (<90 kPa), a sensing range of up to 400 kPa, a response time of 160 ms, and maintains excellent stability after 2000 folding cycles. It can accurately detect human joint flexion and muscle activity. This work is expected to provide a feasible solution for flexible electronic devices applied in human motion monitoring and analysis, particularly offering competitive advantages in applications involving wide-range pressure detection. Full article

The bay scallop (Argopecten irradians) adductor is an attractive raw material for the production of surimi-like products. The gelling properties of raw materials directly affect the quality of surimi-like products. To assess the potential of processing frozen bay scallop adductors into surimi-like products, the effects of short-term freezing treatment on the endogenous transglutaminase (TGase) activity, myofibrillar protein (MP) structure and gelling properties of bay scallop adductors were investigated during 14 days of frozen storage (−18 °C). The results showed that TGase activity in adductor muscles increased significantly during the first 7 days. After 7–14 days, the carbonyl and sulfhydryl contents of the MPs notably changed (increased then decreased). The β-turn content of the MPs increased, indicating stretching and flexibility. Surface hydrophobicity, fluorescence intensity and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated changes in the tertiary structure of the MPs. Compared with gels from fresh samples, gels from scallop adductors frozen for 1 day presented significantly better texture characteristics (breaking force, gel strength, hardness, springiness, cohesiveness, chewiness) and higher water-holding capacity (p < 0.05). However, these properties significantly decreased on the 7th and 14th days (p < 0.05). Microstructural analysis revealed a more compact gel network from 1-day-frozen adductor muscles. These changes in TGase activity and MP structure are key factors influencing the gelling properties of frozen bay scallop adductors. This study provides new insights for improving gel properties during the frozen storage of bay scallop adductors. Full article

To systematically evaluate FB’s effects on tilapia muscle quality, two distinct experimental phases are designed, the crispy texture development phase (0–16 weeks) and the crispy texture retention phase (17–24 weeks), which can determine the minimum faba bean (FB) feeding duration required to achieve optimal textural modification and can assess the persistence of improved textural properties following FB withdrawal, respectively. The results demonstrated that a 60% FB inclusion diet administered for 16 weeks did not adversely affect tilapia growth performance. Significant improvements in textural parameters, including hardness, springiness, chewiness, and shear force, were observed in FB-fed tilapia as early as 8 weeks, with these enhancements being maintained throughout the 16-week feeding period. These superior textural characteristics persisted during the subsequent retention phase following FB withdrawal. Microstructural analysis revealed that the 60% FB diet significantly enhanced muscle-fiber density while reducing fiber diameter in tilapia during the 8–16 week feeding period. These microstructural modifications persisted throughout the texture retention phase, maintaining significant differences compared to the control group. Serological analysis demonstrated the FB group elevated Superoxide dismutase (SOD) activity and reduced malondialdehyde (MDA) levels at 4 weeks, though these differences normalized thereafter. qRT-PCR showed the 60% FB clearly increased the expression of mstn at 8 weeks, while col1a-2 and myog expressions also obviously improved at 12 weeks. In summary, dietary 60% FB improved tilapia muscle crispiness by altering texture and microstructure via gene-expression regulation. The minimum duration was 8 weeks to achieve crispiness in tilapia by the 60% FB diet without adverse effects on growth, immunity, and hepatopancreas function. Furthermore, the crispy texture of tilapia fillets was maintained for at least 2 months following withdrawal of the 60% FB diet after 16 weeks of continuous feeding. Full article

High-temperature cooking can induce oxidation and structural changes in myofibrillar protein (MP), harming meat product quality. 6-gingerol is a key part of ginger and a natural antioxidant. In this study, MP was mixed with 6-gingerol and cooked at different temperatures. Chemical methods, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and molecular docking were used to study the effects on protein aggregation, oxidation, molecular structure, and the microstructure of muscle fibers. The results showed that 40 μg/mL of 6-gingerol significantly optimized the indexes of beef MP. For example, 6-gingerol inhibited the decrease in MP sulfhydryl content and solubility, delayed the rise in surface hydrophobicity and carbonyl content, decreased the particle size of MP, and elevated the absolute value of Zeta potential, which, in turn, hindered oxidative denaturation and the aggregation of proteins. 6-gingerol could maintain the stability of the spatial conformational structure and microstructure of the protein. The protein secondary structure changed, and the α-helical might have been transformed into the β-folded one. The binding of 6-gingerol to MP mainly relied on hydrogen bonds, van der Waals forces, and hydrophobic interactions. Thus, 6-gingerol had a positive effect on the antioxidant properties and structural stability of beef MP during heating. Full article

The application of crayfish muscle in surimi products is a potential way to promote their processing and ensure that it is of a high value. In this study, a one-way completely randomized design was used to prepare mixed surimi gels with different proportions of crayfish muscle. The effect of transglutaminase (TGase) on the improvement in the structural properties, water-binding capacity, micromorphology and protein conformation of blended gels was explored using mass spectrometry, centrifugation, scanning electron microscopy, and Fourier transform infrared spectroscopy. The results of thus study were analyzed by one-way ANOVA showed that in the absence of TGase, crayfish muscle made the microstructure of the blended gel looser and rougher, with a reduction in the strength of the gel and a decrease in the water holding capacity. The addition of 0.6% TGase was able to ameliorate this negative effect by promoting the formation of key chemical bonds and changes in protein conformation, which ultimately led to the enhancement of the crayfish–surimi blended gel properties. Practically, this study provides a viable strategy for incorporating crayfish into surimi products, enabling the development of novel, high-quality seafood products with improved texture and moisture retention, thereby enhancing consumer appeal and reducing waste in crayfish processing. Full article