Search Results (10,071)

Natural fibers are replacing synthetic fibers and are used to develop different useful composite products due to their environmental advantages. To fabricate high-performance composites, high-quality natural fibers are essential. Fiber quality largely depends on the extraction method and subsequent treatment. In this study, fibers were extracted using both machine and manual methods, treated with 5% NaOH, and used at a 30:70 fiber-to-matrix volume ratio to fabricate composite laminates. Key properties such as tensile, flexural, and impact strength, water absorption, elemental composition, and morphological structure were analyzed. When comparing the untreated fiber composites, the machine-extracted samples exhibited a 6.7% increase in tensile strength and a 7.06% increase in flexural strength over those extracted manually. For treated fiber composites, the machine-extracted samples showed improvements in tensile, flexural, and impact strengths of 19.82%, 19.38%, and 26.59%, respectively, compared to those extracted manually. These enhancements indicate that machine extraction provides fibers with better structural integrity and consistency, contributing to stronger fiber–matrix bonding. The machine-extracted treated composites showed reduced water absorption and smaller fiber diameters, indicating that machine extraction was more effective in removing impurities from the fibers. Scanning electron microscopy (SEM) confirmed improved fiber–matrix interfacial bonding in the machine-extracted composites, which also exhibited better water resistance. This study highlights that fiber extraction and treatment significantly influence the mechanical, physical, and morphological properties of natural fiber composites, as verified through SEM, EDS, and universal testing machine (UTM) analysis. Full article

In this work, the synergistic effects of mineral admixtures and advanced mixing processes are systematically accounted for steel fibre-reinforced recycled aggregate concrete (SFR-RAC). It studies the improvement of performance optimization in SFR-RAC, inherently weak ITZ by adding 0.5% hooked steel fibres and replacing cement with ground granulated blast furnace slag (25–50%), fly ash (20–40%) and silica fume (7–14%). The efficiency of double-mixing (DM) and triple-mixing (TM) procedures were comprehensively evaluated. Results showed that mineral admixtures could improve mortar-aggregate interface bond, and the triple-mix technique contributed to such improvement. The maximum performance was observed for the combination of 7%SF with triple mixing (7%SF-TM), which presented increased compressive, tensile and flexural strengths by 7–18%, 12–29%, and 16–31% respectively. The durability was significantly improved, and the water resistance could increase by 53% with addition of 7%SF-TM, chloride penetration depth reduced by 86% when incorporated with 25%GGBS-TM, acid attack decreased by 84% with addition of 14%SF-TM. Microstructural analysis (SEM, XRD) confirmed that these enhancements stem from a denser matrix and refined ITZ due to increased C–S–H formation. This study confirms that the strategic integration of fibre reinforcement, pozzolanic admixtures and optimized mixing protocols presents a viable pathway for producing sustainable concrete from construction waste. Full article

Platelet-rich plasma (PRP) is an autologous blood-derived concentrate increasingly utilized in regenerative medicine for its ability to accelerate healing and tissue repair. PRP is broadly classified by leukocyte content, fibrin architecture, and platelet concentration, with classification systems developed to standardize characterization. Preparation methods, including single- or double-spin centrifugation and buffy coat techniques, influence the final composition of PRP, determining the relative proportions of platelets, leukocytes, plasma proteins, and extracellular vesicles. These components act synergistically, with platelets releasing growth factors (e.g., VEGF, PDGF, TGF-β) that stimulate angiogenesis and matrix synthesis, leukocytes providing immunomodulation, plasma proteins facilitating scaffolding, and exosomes regulating intercellular signaling. Mechanistically, PRP enhances tissue repair through four key pathways: platelet adhesion molecules promote hemostasis and cell recruitment; immunomodulation reduces pro-inflammatory cytokines and favors M2 macrophage polarization; angiogenesis supports vascular remodeling and nutrient delivery; and serotonin-mediated pathways contribute to analgesia. These processes establish a regenerative microenvironment that supports both structural repair and functional recovery. Clinically, PRP has been applied across multiple specialties. In orthopedics, it promotes tendon, cartilage, and bone healing in conditions such as tendinopathy and osteoarthritis. In dermatology, PRP enhances skin rejuvenation, scar remodeling, and hair restoration. Gynecology has adopted PRP for ovarian rejuvenation, endometrial repair, and vulvovaginal atrophy. In dentistry and oral surgery, PRP accelerates wound closure and osseointegration, while chronic wound care benefits from its angiogenic and anti-inflammatory effects. PRP has also favored gingival recession coverage, regeneration of intrabony periodontal defects, and sinus grafting. Although preparation heterogeneity remains a challenge, PRP offers a versatile, biologically active therapy with expanding clinical utility. Full article

Lignocellulosic residues represent a promising source of raw material for obtaining several high-value bioproducts, including cellulose and derivatives. One of the main barriers to cellulose extraction from these residues is the presence of other components associated with the cellulose matrix, such as lignin and hemicellulose. To overcome this limitation, it is necessary to apply specific treatments to remove these constituents. In this study, the effectiveness of three chemical treatment methods in the purification of cellulose extracted from urban pruning biomass of the species Clitoria fairchildiana were evaluated, namely (i) alkaline treatment using dilute sodium hydroxide solution; (ii) alkaline treatment followed by bleaching with hydrogen peroxide; and (iii) alkaline treatment followed by bleaching with hydrogen peroxide and sodium hydroxide combined. The changes in chemical composition and thermal properties caused by each method were analyzed using techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results demonstrated that the biomass pretreatment reduced the content of impurities, lignin, and hemicellulose, increasing the cellulose content to 37.16% in the combined treatment (H₂O₂ + NaOH). Furthermore, the FTIR spectra revealed characteristic bands of important functional groups, which reaffirmed the chemical structure of the extracted cellulose through the identification of hydroxyl, carbonyl groups, and C-H bending vibrations. Additionally, the SEM results indicated an increase in specific surface area and greater exposure of fibrils, providing visual confirmation of the removal of constituents from the cellulosic matrix. Collectively, these results demonstrate the potential of combined chemical treatments for the valorization of Clitoria fairchildiana biomass and indicate its technical feasibility for obtaining cellulose with a higher degree of purity. Full article

This study reports the development of fully biodegradable biocomposites based on polylactic acid (PLA) and polyhydroxybutyrate (PHB) reinforced with alkaline-treated hemp fibers and granules. The thermal, mechanical, dynamic mechanical, and rheological properties of the composites were investigated to assess the influence of reinforcement morphology and content. Differential scanning calorimetry (DSC) confirmed that hemp fibers acted as more effective nucleating agents than granules, increasing the degree of crystallinity of the PLA/PHB blend. Thermal conductivity analysis revealed that hemp incorporation does not systematically improve heat transfer: while long fibers slightly enhanced conductivity, several granule-based composites exhibited lower values than the neat blend. Tensile testing showed that all reinforced samples had lower tensile strength than the neat PLA/PHB matrix, although stiffness was increased, particularly for fiber-based composites. In contrast, flexural strength was maximized in granule-reinforced systems, notably PLA/PHB-2–10-G and PLA/PHB-0.5–10-G, while fibers preserved or improved ductility. Dynamic mechanical analysis confirmed the viscoelastic nature of all composites, with reduced tan δ compared to the neat blend. Rheological testing demonstrated that most composites exhibited lower G′ and complex viscosity than the neat PLA/PHB blend, except for PLA/PHB-2–10-G, which showed stronger matrix–filler interactions. Overall, the results highlight that the performance of PLA/PHB/hemp biocomposites is formulation-dependent, and the selection of hemp morphology and content is crucial for tailoring properties to specific applications. Full article

Injectable biomaterials for vocal fold disorders are being developed to provide not only mechanical reinforcement but also a regenerative microenvironment. Recent hydrogels based on hyaluronic acid (HA) derivatives, calcium hydroxylapatite and decellularized matrix scaffolds are designed to approximate the viscoelastic behavior of native tissue, allow controlled degradation, and modulate local immune responses. Rather than serving merely as space-filling agents, several of these materials deliver extracellular matrix (ECM)-like biochemical signals that help maintain pliability and overcome some limitations of conventional augmentation. Experimental and early clinical studies involving growth factor delivery, stem cell-based injections, and ECM-mimetic hydrogels have demonstrated improved mucosal wave vibration and reduced fibrosis in cases of scarring. In clinical series, benefits from basic fibroblast growth factor can persist for up to 12 months. Further progress will depend on correlating material properties with objective vibratory performance to achieve lasting restoration of phonation and advance true tissue-regenerative therapy. Full article

The growing global demand for clean energy and sustainability has increased interest in lignocellulosic biomass as a viable alternative to conventional fossil fuels. Among the various biomass resources, sugarcane bagasse, an abundant agro-industrial by-product, has emerged as a promising feedstock to produce renewable fuels and value-added chemicals. Its high carbohydrate content offers significant potential for bioconversion. However, its complex and recalcitrant lignocellulosic matrix presents significant challenges that necessitate advanced pretreatment techniques to improve enzymatic digestibility and fermentation efficiency. This review consolidates recent developments in the valorization of sugarcane bagasse focusing on innovative pretreatment and fermentation strategies for sustainable bioethanol production. It emphasizes the synergistic benefits of integrating various pretreatment and fermentation methods to improve bioethanol yields, reduce processing costs and enhance overall process sustainability. This review further explores recent technological advancements, the impact of fermentation inhibitor, and emerging strategies to overcome these challenges through microbial strains and innovative fermentation methods. Additionally, it highlights the multi-faceted advantages of bagasse valorization, including waste minimization, renewable energy production and the promotion of sustainable agricultural practices. By evaluating the current state of research and outlining future perspectives, this paper serves as a comprehensive guide to advancing the valorization of sugarcane bagasse in the transition towards a low-carbon economy. The novelty of this review lies in its holistic integration of technological, economic, and policy perspectives, uniquely addressing the scalability of integrated pretreatment and fermentation processes for sugarcane bagasse, and outlining practical pathways for their translation from laboratory to sustainable industrial biorefineries within the circular bioeconomy framework. Full article

This paper presents research and theoretical development of a mathematical model that, first, allows us to understand how the positional exactitude of the output link of a four-bar mechanism depends on the manufacturing dimensional tolerances. To find this dependence, the total differentials of the kinematic constraint functions that govern the field of positions must be determined for each kinematic cycle of the mechanism under consideration. These total differentials lead to a system of equations whose solution gives the positional errors of the movable output links as a function of the manufacturing dimensional errors and an incidence matrix that varies with each one of the positions of the input element. On the other hand, the theoretical transmission ratio between the output velocities with respect to the input velocity of the articulated kinematic chain is defined, and for determining the total errors in each ratio, the total differential of each one of them is calculated, showing a clear dependence with respect to the positional errors of the output links (previously defined) of the mechanism. The sum of the theoretical transmission ratio and its respective error provides the real transmission ratio. Furthermore, the described methodology allows for determining the sensitivity (influence coefficients) in the transmission ratios due to errors inherent in the link lengths. Finally, the presented analytical approach is numerically implemented through an example of articulated parallelogram design, principally characterizing in graphic form the transmission ratios in their regions of permitted movements and blocking positions, for a specific IT degree of precision of the bilateral dimensional tolerances of their functional geometric parameters, with the objective of analyzing every aspect related to the performance of the mechanisms. This formalism is validated through three particular design cases using a CAD model in a simulation module of kinematic motion analysis; additionally, the evolution of the transmission angle is discussed. The methods and conclusions proposed in this document also leave open the way as future work to study separately the magnitudes and signs of the positional errors and the transmission ratio, or even the influence coefficients themselves, in order to assign the most convenient degree of IT precision for each link in the mechanism with the purpose of reducing errors in the designs and obtain better efficiency in the transmission ratio. Full article

Therapeutic strategies targeting “tumor-educated platelets” (TEPs) and platelet–tumor interactions by key signaling pathways (ITAM, P2Y12) may reduce metastasis and cancer. Using a TEP gene expression dataset originally created to study swarm intelligence-enhanced detection of lung cancer cells (GSE89843), we did perform extensive transcriptome analysis to integrate these data with directed protein–protein interactions and build a TEP-specific signaling network. We analyze network topology and controllability and identify critical and indispensable nodes, as well as high-weight, usually high-score nodes. We reconstruct (pharmacological) controllable subnetworks of TEP signaling, which we then explore for drugs targets. We found 111 upregulated and 108 downregulated genes compared to control platelets, enriched in pathways related to extracellular matrix interactions, cytoskeleton organization, immune signaling, and platelet activation. Ribosomal function, apoptosis, and immune signaling were among the downregulated processes, highlighting unique TEP profiles in non-small-cell lung cancer (NSCLC). Our integrative analysis of TEPs in NSCLC reveals key transcriptional and network-based alterations harmful for the cancer patient. Using four complementary strategies, we identified five high-confidence genes (Gene symbols always given throughout the paper), ITGA2B, FLNA, GRB2, FCGR2A, and APP, as central to TEP signaling. These can be targeted by FDA-approved drugs. Fostamatinib, an SYK inhibitor, emerged as the top candidate drug to disrupt ITAM-mediated platelet activation selectively; metastasis-promoting metalloprotease and cytoskeletal targets influencing adhesion were also identified. A low-dose combination therapy of fostamatinib, Aducanumab, and acetylsalicylic acid (aspirin) may control TEP effects. In conclusion, our preclinical in silico approach revealed FDA-approved drugs that allow therapeutic targeting of metastasis-promoting TEPs and target NSCLC at the same time. Full article

Valorization of municipal solid waste (MSW) for energy represents a strategic alternative for developing countries, as it mitigates emissions, reduces pressure on landfills, and diversifies the electricity matrix. This study quantified the potential for electricity generation from MSW in the Jequitinhonha Valley, Minas Gerais, Brazil, using primary gravimetric characterization data, a method rarely employed in tropical areas. The identified composition showed a predominance of the organic fraction (47.6–73.3%), confirming the relevance of biological routes. The results indicated a consolidated potential of 106,640 MWh·year⁻¹, of which 94.7% was from biogas recovery and 5.3% from incineration. Almenara, one of the three locations analyzed, showed the highest potential (48,200 MWh·year⁻¹), followed by Diamantina (34,540 MWh·year⁻¹) and Capelinha (23,900 MWh·year⁻¹). The specific yields ranged from 0.33 to 0.53 MWh·ton⁻¹ MSW and the per capita indicators from 1.01 to 1.49 MWh·cap⁻¹·year⁻¹. The climate mitigation potential reached 1.0 Mt of CO₂eq·year⁻¹. It is concluded that valorization in the Jequitinhonha Valley should prioritize biogas recovery, complemented by the incineration of rejects. The materialization of this potential requires advancements in infrastructure, selective collection, and socio-productive inclusion. This study provides evidence for public policies and contributes to the literature by demonstrating that valorization can boost energy transition and socio-environmental equity in developing tropical regions. Full article

Charcot–Marie–Tooth disease type 1A (CMT1A) is a hereditary condition caused by the duplication of the PMP22 gene. Overexpression of peripheral myelin protein 22 in Schwann cells leads to myelin sheath defects and axonal loss. We have produced a cell model to facilitate studies of the molecular mechanisms involved in PMP22 accumulation and clearance. Our model is a stably transfected, clonal, immortalised human Schwann cell line with overexpressed levels of PMP22 fusion protein. A control-transfected cell line (vector lacking PMP22) was also produced. PMP22-transfected cells had reduced levels of mitosis, with the PMP22 fusion protein concentrated in punctate aggregates in the cytoplasm and expressed at the plasma membranes, which were often irregular and spindly. In contrast, control cells (control-transfected and parent cell lines) generally had smooth and regular plasma membrane morphology. Culturing in the presence of NRG1 and forskolin lead to upregulation of markers of myelination potential in the control cells. These markers were more variable in the cells stably transfected with PMP22, including decreased levels of transcripts of SOX10, JUN, S100B and NGFR, but increased levels of MPZ and EGR2 compared to controls. Using proximity-dependent biotin identification (BioID2), several hundred proteins were identified in the proximity of the overexpressed PMP22, of which 291 significant proteins were only detected in the proximity of PMP22 and not in that of control pull-downs. Among the most significantly enriched PMP22-interacting proteins were integrins alpha-2 (ITGA2) and alpha-7 (ITGA7), which play a role in myelination via their interactions with the extracellular matrix. The presence of ITGA2 in just the PMP22-transfected fraction was confirmed by western blot. Some of the proteins were associated with several enriched molecular pathways, including molecular transport and protein trafficking, and may represent potential therapeutic targets for CMT1A by promoting the degradation and enhanced trafficking of PMP22. Full article

Milk represents not only a source of essential nutrients but also a versatile matrix for the development of functional foods when combined with lactic acid bacteria (LAB) fermentation. While cow milk is the most widely consumed, alternative matrices such as goat and donkey milk possess distinctive compositional features that may influence the bioactivity of fermented products. In this work, fifteen different strains belonging to LAB and bifidobacteria were initially tested for their ability to ferment cow, goat, and donkey milk. Fermented samples showing the best acidification rate were further screened for total phenolic content (TPC), radical scavenging activity (RSA), and effects in human colon epithelial cells and Caco-2 adenocarcinoma cells. The results showed that fermentation modulated TPC in a strain- and matrix-dependent manner, with donkey milk showing the most consistent increases. RSA was significantly enhanced in fermented samples, particularly those inoculated with Lacticaseibacillus casei BGP93 and LC4P1 strains and Limosilactobacillus reuteri ATCC23272. Cell viability assays confirmed the absence of cytotoxicity, and fermented milk extracts reduced ROS under induced oxidative stress. Antimicrobial assay showed that Lactiplantibacillus plantarum LPAL selectively inhibited Listeria monocytogenes, with the strongest effect observed in donkey milk. These findings suggest that LAB-fermented milks from goats and donkeys may represent safe functional foods with improved antioxidant and antimicrobial activities. Full article

The increasing demand for enhanced wear resistance and mechanical integrity in tooling applications has driven the development of advanced surface engineering strategies for high-alloy steels. Böhler K390 MICROCLEAN, a powder-metallurgical V–Cr–Mo–W cold work tool steel with high vanadium content, features a composite metal matrix–carbide microstructure, consisting of uniformly distributed coarse vanadium carbides and finer carbides (M₇C₃, M₆C/MC) embedded in a ferritic matrix. This study investigated the effects of non-melting laser surface treatment (LST) applied to both as-received and bulk heat-treated K390 specimens. Microstructural characterization using SEM, EBSD, XRD, and EDX revealed the formation of a hardened surface layer comprising a structureless mixture of ultrafine-grained martensite and retained austenite, localized around vanadium carbides. Lattice parameter analysis and Williamson–Hall evaluation demonstrated increased carbon content, lattice distortion, and crystallite size reduction, contributing to high dislocation density (6.4 × 10¹⁴ to 2.6 × 10¹⁵ m⁻²) and enhanced hardness. Microhardness was increased by up to 160% compared to the initial state (reaching 835–887 HV₂₀), and dry-sliding testing showed up to 3.94 times reduced volume loss and decreased friction coefficients. Wear occurred via the formation and delamination of thin oxide tribo-layers, which enhanced the wear behavior. The combined approach of bulk heat treatment followed by LST produced a graded microstructure with superior mechanical stability, offering clear advantages for extending tool life under severe contact loads in stamping and forming operations. Full article

Photosystem I (PSI) is a photosynthetic protein–pigment complex that, upon photoexcitation, transfers electrons to ferredoxin, facilitating the production of NADPH. Isolated PSI reaction centers (RCs) have also been used in hybrid systems to reduce protons and produce ‘biohydrogen’. This review article examines how various cyanobacteria with similar photosynthetic machinery utilize different wavelengths of light to execute photosynthetic electron transport through PSI. Key factors, such as, the structure of the electron transfer cofactors, the protein environment surrounding the primary donor pigments and hydrogen-bonding interactions with the surrounding protein matrix are analyzed to understand their roles in maintaining efficient electron transfer when it is driven using photons of different energies. We compare PSI complexes with known atomic structures from four species of cyanobacteria, Thermosynechococcus elongatus, Acaryochloris marina, Halomicronema hongdechloris, and Fischerella thermalis. T. elongatus is typical of most oxygenic photosynthetic organisms in that it requires visible light and uses only chlorophyll a (Chl a) in PSI. In contrast, H. hongdechloris and F. thermalis are photoacclimating species capable of producing Chl f and Chl d that use red light when little visible light is available. A. marina, on the other hand, is adapted to red light conditions and consistently utilizes Chl d as its primary photosynthetic pigment, maintaining a stable pigment composition. Here, we explore the structural and functional differences between the PSI RCs of these organisms and the impact of these differences on electron transport. The structural differences in the cofactors influence both the absorption wavelengths of the cofactors and the energy levels of the intermediate states of electron transfer. An analysis of the surrounding protein shows how it has been adapted and underscores the interplay between the pigment structure, protein environment, and hydrogen bonding networks in tuning the efficiency and adaptability of photosynthetic mechanisms across different species of cyanobacteria. Full article

Low-permeability glutenite reservoirs in the Qaidam Basin, NW China, exhibit intricate pore networks and strong heterogeneity that hinder effective hydrocarbon development. Here, we integrate thin-section petrography, scanning electron microscopy (SEM), mercury injection capillary pressure (MICP), and nuclear magnetic resonance (NMR) to characterize pore types and establish quantitative links between fractal dimension and petrophysical properties. The reservoirs are mainly pebbly sandstones and sandy conglomerates with 15–23% quartz, 27–37% feldspar, and 2–20% carbonate/muddy matrix. Helium porosity ranges from 5.12% to 18.11% (mean 9.39%) and air permeability from 60 to 3270 mD (mean 880 mD). Fine pores (1–10 μm) dominate, throats are short and poorly connected, and illite (up to 16.76%) lines pore walls, further reducing permeability. Fractal analysis yields weighted-average dimensions of 2.55, 2.50, and 2.15 for macro-, meso-, and micropores, respectively, giving an overall dimension of 2.52. Higher dimensions correlate negatively with porosity and permeability. Empirical models (quadratic for porosity and exponential for permeability) predict core data within 0.86% and 5.4% error, validated by six blind wells. Reservoirs are classified as Class I (>12%, >1.0 mD), Class II (8–12%, 0.5–1.0 mD), and Class III (<8%, <0.5 mD), providing a robust tool for stimulation design and numerical simulation. Full article