Search Results (43)

Accurate absolute pressure measurement is of great importance in industrial control, environmental monitoring, and aerospace. Traditional fiber-optic Fabry–Perot (F-P) pressure sensors usually involve complex microfabrication and high-cost demodulation systems, while conventional diaphragm capsule sensors are limited in sensitivity and resolution. This work presents a low-cost, high-resolution fiber-optic F-P absolute pressure sensor. The sensor uses a vacuum capsule as one reflective surface and a partially reflective fiber collimator as the other, forming a low-finesse F-P interferometer. The cavity length is linearly modulated by the elastic deformation of the capsule under pressure, and high-precision demodulation is realized using frequency modulated continuous wave (FMCW) interferometry instead of conventional spectral methods. Static experiments from 10 to 110 kPa show that the sensor exhibits a high sensitivity of 15,105 nm/kPa and a resolution of 3.3 Pa. Furthermore, the sensor operates normally within the range of −20 °C to 70 °C, exhibiting a pressure–temperature cross-sensitivity of 0.081 kPa/°C and a cavity length drift of 496 nm/h. With the advantages of high performance, simple structure, low cost, and good scalability by selecting different capsules, the proposed sensor has promising potential for practical applications in pressure measurement fields. Full article

The development of advanced wound dressings that integrate favorable physico-mechanical properties with the ability to support physiological healing processes remains a critical challenge in biomaterials science. An ideal dressing should modulate the wound microenvironment, prevent infection, maintain hydration, and possess adequate strength and elasticity. This study aimed to fabricate and characterize electrospun chitosan (CS)-based 3D scaffolds dual-reinforced with halloysite nanotubes (HNTs) and cerium oxide nanoparticles (CeONPs) to enhance material properties and biological performance. HNTs were incorporated to improve electrospinnability and provide mechanical reinforcement, while CeONPs were added for their redox-modulating and anti-inflammatory activities. Composite mats were fabricated via non-capillary electrospinning. The individual and synergistic effects of HNTs and CeONPs were systematically evaluated using physico-chemical methods (SEM, EDX, WAXS, TGA, mechanical testing) and biological assays (in vitro cytocompatibility with mesenchymal stem cells, in vivo biocompatibility, and wound healing efficacy in a rat model). Scaffolds containing only HNTs exhibited defect-free nanofibers with an average diameter of 151 nm, whereas the dual-filler (CS-PEO-HNT-CeONP) composites showed less uniform fibers with a rough surface and a larger average diameter of 233 nm. The dual-filler system demonstrated significantly enhanced mechanical properties, with a Young’s modulus nearly double that of pure CS mats (881 MPa vs. 455 MPa), attributed to strong interfacial interactions. In vivo, the CS-PEO-HNT-CeONP scaffolds degraded more slowly, promoted earlier formation of a connective tissue capsule, and elicited a reduced inflammatory response compared to single-filler systems. Although epithelialization was temporarily delayed, the dual-filler composite ultimately facilitated superior tissue regeneration, characterized by a more organized, native-like collagen architecture. The synergistic combination of HNTs and CeONPs within a CS matrix yields a highly promising scaffold for wound management, offering a unique blend of tailored biodegradability, enhanced mechanical strength, and the ability to guide healing towards a regenerative rather than a fibrotic outcome, particularly for burns and traumatic injuries. Full article

Background/Objectives: Cryptococcus gattii presents a significant threat to healthy individuals. Titan cell formation, a key virulence factor, is influenced by the nutritional environment and plays a critical role in immune evasion and stress resistance. This study investigates the molecular and biophysical changes in titanized C. gattii cells grown in nutrient-rich Neurobasal™ medium, a potent inducer of titan cells. Methods: An integrative approach was used, combining scanning electron microscopy, optical tweezers, fluorescence microscopy, and physicochemical methods to analyze C. gattii cells grown in Neurobasal™ medium and minimal media. Results: Cells grown in Neurobasal™ medium exhibited significant differences compared to those grown in minimal media. These included a thicker and more defined polysaccharide capsule, enhanced capsule elasticity, and the secretion of more elastic polysaccharides. Furthermore, cells grown in the enriched medium showed reduced susceptibility to antifungals and delayed mortality in infection models. Conclusions: C. gattii adapts to nutritional cues by forming titan cells, thereby enhancing its pathogenicity. Targeting nutritional sensing pathways may offer novel therapeutic strategies against cryptococcal infections. Full article

This study aimed to evaluate the effects of a proprietary plant-based formulation of Astragalus membranaceus and Centella asiatica saponins (ACS) on skin health, as both a cosmetic ingredient and a functional supplement. In this randomized, double-blind, placebo-controlled trial, 150 healthy adults were assigned to groups using topical ACS cream, oral ACS capsules, combined treatments, or corresponding placebos. Skin brightness, moisture, elasticity, melanin value, pore count, texture, and collagen content were assessed over 4 to 12 weeks. After 4 weeks of topical ACS application, skin brightness improved by 2.5%, elasticity by 6.5%, melanin decreased by 5.2%, pores reduced by 10.6%, and collagen increased by 8.7% (p < 0.05). After 12 weeks of oral ACS, brightness, elasticity, texture, and collagen significantly improved (p < 0.05). The combined treatment group showed the greatest improvements, including a 4.2% increase in brightness, 12.9% increase in moisture, 9.0% elasticity increase, and a 28.5% reduction in pore count (p < 0.05). ACS, whether used topically, orally, or in combination, effectively enhances skin health and offers a natural solution for skin rejuvenation. Full article

Background: In 1927, Cochrane observed persistent elastic resistance to hallux dorsiflexion after cheilectomy for hallux rigidus, attributing it to soft tissue tightness beneath the first metatarsophalangeal (MTP) joint. An innovative surgery was introduced using a plantar approach, dividing the plantar tissues. This procedure achieved complete pain resolution and high satisfaction in 12 patients. Despite addressing the etiology of hallux rigidus, this approach has not been adopted in current surgeries. This report presents a case treated with the arthroscopic Cochrane procedure with a long-term follow-up. Methods: A 73-year-old male with hallux rigidus presented with limited dorsiflexion, a painful bony prominence, and pain during walking at the first MTP joint, treated with the arthroscopic Cochrane procedure. Results: During surgery, hallux dorsiflexion did not improve after resecting all spurs in the MTP joint, but the dorsiflexion angle immediately improved from 55° to 85°after releasing the flexor hallucis brevis tendon, plantar capsule, and plantar portion of the lateral ligament. Improvements in both visual analog scale scores (70–0) and Japanese Society for Surgery of the Foot scores (57–88) were noted from preoperatively to 9 years and 6 months postoperatively. No postoperative cockup deformity was observed. Conclusions: The arthroscopic Cochrane procedure can yield favorable long-term outcomes without postoperative cockup deformity. Full article

The utilization of gelatin capsule waste (GCW) poses a challenge for the industry. This study investigates its potential as a functional food ingredient by evaluating the physico-chemical, rheological, and techno-functional properties of gelatin capsule waste powder (GCWP). To achieve this, the gelatin capsule waste (GCW) was mixed with maltodextrin at varying ratios (1:1, 1:2, 1:3, 1:4, and 1:5) and subjected to spray drying. The findings highlight maltodextrin’s crucial role in stabilizing the drying process, reducing stickiness, and enhancing handling and storage properties. All the obtained GCWP samples appeared light white and had a slightly sticky texture. The 1:5 (w/w) GCW-to-maltodextrin ratio produced the highest powder recovery with minimal stickiness, indicating enhanced drying efficiency. Increasing maltodextrin reduced gel strength, texture, and foaming properties while raising the glass transition temperature. The FTIR analysis indicated a decline in protein–protein interactions and increased polysaccharide interactions at higher maltodextrin levels. The rheological analysis demonstrated lower elastic and loss moduli with increased maltodextrin, affecting GCWP’s structural behavior. For overall properties, the GCW mixed with maltodextrin at a 1:1 ratio (GCW-1M) is recommended for future applications, particularly for its gelling characteristics. The GCW-1M, being rich in amino acids, demonstrates its potential as a functional food ingredient. However, certain properties, such as gel strength and powder stability (hygroscopicity and stickiness), require further optimization to enhance its industrial applicability as a functional food ingredient. Full article

Background/Objectives: The repetitive overhead throwing of baseball stresses the posterior shoulder, including the rotator cuff and capsule, causing stiffness, tissue thickening, and dysfunction. Previous studies on collegiate baseball players have linked these changes to glenohumeral internal rotation deficits, pain, and injuries. However, these studies primarily used acoustic radiation force impulse-based shear wave elastography (SWE), which has limitations, including tissue heating and lack of portability. The acute effects of pitching on infraspinatus (ISP) muscle elasticity in high school pitchers remain unclear. Therefore, this study aimed to evaluate the acute impact of pitching on ISP muscle elasticity in high school baseball pitchers using continuous SWE (C-SWE), which is a safer and more portable method. The relationship between ISP muscle elasticity and pitching load was also examined. Methods: ISP muscle shear wave velocity (SWV), shoulder range of motion, and strength were evaluated in high school baseball pitchers. The participants were categorized into pitching and non-pitching groups based on whether they pitched with full effort on the day of their medical checkup. C-SWE was used to assess ISP muscle elasticity. Results: The pitching group had considerably higher ISP muscle SWV on the dominant side than the non-pitching group (p = 0.008). A significant positive correlation was observed between pitch and ISP muscle SWV (r = 0.467, p = 0.003). Conclusions: Repetitive pitching acutely increases ISP muscle stiffness in high school pitchers, contributing to posterior shoulder tightness. C-SWE is a safe and practical method for assessing tissue elasticity and developing injury prevention strategies. Full article

Background: Telocytes are interstitial stromal cells identified in various human organs, including the kidney. Their presence and role in human diabetic kidney disease remain unknown. Methods: To identify and localize telocytes in glomerular and tubule-interstitial compartments, both normal and diabetic human renal tissues were examined using immunohistochemistry, immunofluorescence, and transmission electron microscopy. Results: Renal telocytes are elongated interstitial cells with long, thin telopodes, showing alternating thin and thick segments. They expressed CD34, Nestin, α-SMA, and Vimentin markers. Occasionally, c-Kit expression was observed in some rounded and spindle cells, while no positivity was detected for PDGFR-β and NG2. Telocytes were identified around Bowman’s capsule, tubules, and peritubular capillaries in both normal and diabetic conditions. In diabetic renal samples, there was a significant increase in α-SMA expressing telocytes, leading to periglomerular fibrosis. These telocytes also exhibited a synthetic phenotype with proteoglycan deposition in the extracellular matrix and, in some cases, showed pre-adipocytic differentiation. Conclusions: Telocytes were identified in normal and diabetic human kidneys. These cells form an elastic mechanical scaffold in the interstitium and are present in all renal cortical compartments. In diabetic samples, their increased α-SMA expression and synthetic phenotype suggest their potential role in the pathogenesis of diabetic nephropathy. Full article

The in situ study of fractal microstructure in nanocarbon polymers is an actual task for their application and for the improvement in their functional properties. This article presents a visualization of the bulk structural features of the composites using pulsed acoustic microscopy and synchrotron X-ray microtomography. This article presents details of fractal structure formation using carbon particles of different sizes and shapes—exfoliated graphite, carbon platelets and nanotubes. Individual structural elements of the composite, i.e., conglomerations of the particles in the air capsule as well as their distribution in the composite volume, were observed at the micro- and nanoscale. We have considered the influence of particle architecture on the fractal formation and elastic properties of the composite. Acoustic and X-ray imaging results were compared to validate the carbon agglomeration. Full article

The product of ozonolysis, glycero-(9,10-trioxolane)-trioleate (ozonide of oleic acid triglyceride, [OTOA]), was incorporated into polylactic acid/polycaprolactone (PLA/PCL) blend films in the amount of 1, 5, 10, 20, 30 and 40% w/w. The morphological, mechanical, thermal and antibacterial properties of the biodegradable PLA/PCL films after the OTOA addition were studied. According to DSC and XRD data, the degree of crystallinity of the PLA/PCL + OTOA films showed a general decreasing trend with an increase in OTOA content. Thus, a significant decrease from 34.0% for the reference PLA/PCL film to 15.7% for the PLA/PCL + 40% OTOA film was established using DSC. Observed results could be explained by the plasticizing effect of OTOA. On the other hand, the PLA/PCL film with 20% OTOA does not follow this trend, showing an increase in crystallinity both via DSC (20.3%) and XRD (34.6%). OTOA molecules, acting as a plasticizer, reduce the entropic barrier for nuclei formation, leading to large number of PLA spherulites in the plasticized PLA/PCL matrix. In addition, OTOA molecules could decrease the local melt viscosity at the vicinity of the growing lamellae, leading to faster crystal growth. Morphological analysis showed that the structure of the films with an OTOA concentration above 20% drastically changed. Specifically, an interface between the PLA/PCL matrix and OTOA was formed, thereby forming a capsule with the embedded antibacterial agent. The moisture permeability of the resulting PLA/PCL + OTOA films decreased due to the formation of uniformly distributed hydrophobic amorphous zones that prevented water penetration. This architecture affects the tensile characteristics of the films: strength decreases to 5.6 MPa, elastic modulus E by 40%. The behavior of film elasticity is associated with the redistribution of amorphous regions in the matrix. Additionally, PLA/PCL + OTOA films with 20, 30 and 40% of OTOA showed good antibacterial properties on Pseudomonas aeruginosa, Raoultella terrigena (Klebsiella terrigena) and Agrobacterium tumefaciens, making the developed films potentially promising materials for wound-dressing applications. Full article

The objective of this study was to investigate the elastic and plastic responses of 3D-printed thermoplastic elastomer (TPE) beams under various bending loads. The study also aimed to develop a self-healing mechanism using origami TPE capsules embedded within an ABS structure. These cross-shaped capsules have the ability to be either folded or elastically deformed. When a crack occurs in the ABS structure, the strain is released, causing the TPE capsule to unfold along the crack direction, thereby enhancing the crack resistance of the ABS structure. The enhanced ability to resist cracks was confirmed through a delamination test on a double cantilever specimen subjected to quasi-static load conditions. Consistent test outcomes highlighted how the self-healing process influenced the development of structural cracks. These results indicate that the suggested self-healing mechanism has the potential to be a unique addition to current methods, which mostly rely on external healing agents. Full article

Numerical analysis computational programs are applied to the research of biological tissues, which have complex forms. Continuous technological advance has facilitated the development of biomodels to evaluate biological tissues of different human body systems using computerized axial tomography to produce complex three-dimensional models that represent the morphological and physiological characteristics of the real tissues. Biomodels are applied to numerical analysis using the Finite Element Method and provide a perspective of the mechanical behavior in the system. In this study, a numerical evaluation was performed by developing a biomodel of the humerus, radius, and ulna (the elbow joint, composed of cortical bone, trabecular bone, and cartilage). Also introduced to the biomodel were the ligaments of the capsule joint, collateral ligaments of the ulna, and collateral ligaments of the radius. The biomodel was imported into a computer program to perform a numerical analysis considering the mechanical properties of cortical and trabecular bone (including elasticity modulus, shear modulus, Poisson relation, and density). The embedding conditions were defined to restrict displacements and rotations in the proximal zone of the humerus, applying a compression load to the other end of the biomodel at the distal area of the radius and ulna. The results are the direct consequence of how boundary conditions and external agents are applied to the structure to be analyzed, and the data obtained show how the behavior of the force applied through the component produces stresses and strains as a whole, as well as for each of the components. These stresses and strains can indicate zones with structural problems and the detection areas causing pain (assisting in a better diagnosis). Full article

Characterized in biomedical terms, stretching exercises have been defined as movements applied by external and/or internal forces to increase muscle and joint flexibility, decrease muscle stiffness, elevate the joint range of motion (ROM), increase the length of the “muscle–tendon” morpho-functional unit, and improve joint, muscle, and tendon movements, contraction, and relaxation. The present review examines and summarizes the initial and recent literature data related to the biomechanical, physiological, and therapeutic effects of static stretching (SS) on flexibility and other physiological characteristics of the main structure and the “joint–ligament–tendon–muscle” functional unit. The healing and therapeutic effects of SS, combined with other rehabilitation techniques (massage, foam rolling with and without vibrations, hot/cold therapy, etc.), are discussed in relation to the creation of individual (patient-specific) or group programs for the treatment and prevention of joint injuries, as well as for the improvement of performance in sports. From a theoretical point of view, the role of SS in positively affecting the composition of the connective tissue matrix is pointed out: types I–III collagen syntheses, hyaluronic acid, and glycosaminoglycan (GAG) turnover under the influence of the transforming growth factor beta-1 (TGF-β-1). Different variables, such as collagen type, biochemistry, elongation, and elasticity, are used as molecular biomarkers. Recent studies have indicated that static progressive stretching therapy can prevent/reduce the development of arthrogenic contractures, joint capsule fibrosis, and muscle stiffness and requires new clinical applications. Combined stretching techniques have been proposed and applied in medicine and sports, depending on their long- and short-term effects on variables, such as the ROM, EMG activity, and muscle stiffness. The results obtained are of theoretical and practical interest for the development of new experimental, mathematical, and computational models and the creation of efficient therapeutic programs. The healing effects of SS on the main structural and functional unit—“joint–ligament–tendon–muscle”—need further investigation, which can clarify and evaluate the benefits of SS in prophylaxis and the treatment of joint injuries in healthy and ill individuals and in older adults, compared to young, active, and well-trained persons, as well as compared to professional athletes. Full article

Microcapsules of urea-formaldehyde (UF) containing dicyclopentadiene (DCPD) were synthesized by the in situ polymerization technique for self-healing of epoxy. The dispersion of microcapsules in the epoxy matrix was achieved using ultrasonication. Composites of epoxy, having 0.5, 1.0, 1.5, and 2.0 wt.% of microcapsules capable of self-healing, were prepared. The shape and size of the microcapsules were determined by field emission electron microscopy. Spherical capsules of DCPD, with an average diameter of 172 nm, were obtained. Investigation of tensile properties indicated a decrease in the tensile modulus with an increase in wt.% of microcapsules. There was a reduction of 22%, 27%, 39%, and 30% in the elastic modulus of composites for 0.5, 1.0, 1.5, and 2.0 wt.% of microcapsules, respectively. Tensile strength was found to increase with an increase in wt.% of microcapsules. The tensile strength of the composites increased by 33%, 20%, 8%, and 21% for 0.5, 1.0, 1.5, and 2.0 wt.% of microcapsules, respectively, in comparison with that of neat epoxy. The fatigue life of composites was investigated by conducting uniaxial tension–tension fatigue tests at constant stress amplitudes of 20, 25, 30, and 35 MPa, at a constant stress ratio (R = 0.1) and a frequency of 3 Hz. The fatigue life of composites increased with an increase in wt.% of microcapsules in comparison with that of neat epoxy. It was found that the fatigue life of the composites decreased with 1.5 and 2.0 wt.% of microcapsules in comparison with composites with 0.5 and 1.0 wt.% of microcapsules. The fracture surfaces of the tested samples were examined with the help of scanning electron microscopy (SEM) to understand the various mechanisms responsible for the change in modulus, strength, failure strain, and fatigue life of composites. Full article

NVMe-over-Fabrics (NVMeoF) is expected to have high-performance and be highly scalable for disaggregating NVMe SSDs to High-Speed Network (HSN)-attached storage servers, thus the aggregated NVMe SSDs in storage servers can be elastically allocated to remote host servers for better utilization. However, due to the well-known connection scalability issue of RDMA NICs (RNICs), RDMA-enabled HSN can only provide a limited scale of performant Queue Pairs (QPs) for NVMeoF I/O queues to transfer capsule and data between the storage server and remote host servers. However, in current NVMeoF implementations, multiplexing multiple NVMeoF I/O queues onto a single RNIC QP is not supported yet. In this paper, we investigate how NVMeoF capsule and data transfers are performed efficiently over HSN with a limited number of RNIC QPs, and propose SPANoF, a Scalable and Performant Architecture for NVMe-over-Fabrics. SPANoF dissolves the intrinsic one-to-one mapping relationship between NVMeoF I/O queues and RNIC QPs, allocates a dedicated send-list for each NVMeoF I/O queue rather than for each RNIC QP, transfers NVMeoF capsules and data in send-lists with a QP-centric manner to remove lock-contention overhead, and polls for transfer completion notifications to remove interrupt-caused context switch overhead. We implemented SPANoF in the Linux kernel and evaluated it by the FIO benchmarks. Our experimental results demonstrate that SPANoF can avoid the performance collapses for commercial RNICs with a limited number of performant QPs and avoid the system crash for domain-specific RNICs with only limited-scale available QPs. Compared with the native NVMeoF implementation in Linux kernel, SPANoF can saturate an RNIC of the storage server with only three RNIC QPs of the remote host server. Compared with lock-based QP-sharing mechanisms, SPANoF improves bandwidth by up to 1.55× under 64 KB sequential write requests, improves throughput by up to 4.18× and reduces the average latency by 28.31% under 4 KB random read requests. Full article