Search Results (34)

Rotational friction welding offers an adhesive-free approach for producing wood dowel joints, but pull-out performance and process consistency are strongly affected by the welding parameters. This study investigated the effects of the hole-to-dowel diameter ratio, rotational speed, and plunging rate on rotationally friction-welded beech (Fagus sylvatica L.) dowel joints. An L9 orthogonal design was combined with supplementary testing, curve-based validity assessment, post-peak analysis, post-pull-out surface imaging, and independent validation. Range analysis ranked the parameter effects as plunging rate, hole-to-dowel diameter ratio, and rotational speed. Type III analysis of variance confirmed significant effects of the hole-to-dowel diameter ratio and plunging rate, whereas rotational speed was not significant within 1600–2000 rpm. The predicted combination was a ratio of 0.80, 1800 rpm, and 14 mm·s⁻¹. The validation group reached 2567.22 N, 34.96% above T3, but its coefficient of variation of 35.93% showed that considerable variability remained. All joints failed by complete dowel withdrawal; the exposed dowel surfaces indicated mixed interfacial separation, sliding, and localized wood-fiber tearing. Darkened regions occurred at different speed levels, without consistent evidence of extensive burning at 2000 rpm. High-capacity joints also showed more abrupt post-peak degradation, indicating a trade-off between capacity, consistency, and failure suddenness. Full article

Corrosion-protective coatings have progressed from passive barrier systems and chromate-based technologies toward multifunctional materials that integrate barrier durability, interfacial adhesion, active inhibition, electrochemical response, and self-healing capabilities. However, the intellectual framework connecting these technological developments remains fragmented, as most reviews focus on specific material families rather than on the broader evolution of the field. This study examines technological paradigms in corrosion-protective coatings through a citation network analysis of highly cited publications retrieved from Web of Science and processed with CitNetExplorer. The most influential publications were thematically reviewed to identify dominant materials, coating architectures, protection mechanisms, seminal contributions, and bridge articles. Four principal paradigms were identified: smart and self-healing coatings based on nanocontainers, layered double hydroxides, mesoporous silica, halloysite, zeolites, hydroxyapatite reservoirs, and microcapsules; chromate-free sol–gel and silane pretreatments based on organic–inorganic hybrid matrices, organosilanes, rare-earth inhibitors, and oxide nanoparticles; graphene and graphene oxide-based nanocomposite coatings in which two-dimensional fillers enhance tortuosity, reduce water uptake, and reinforce polymer matrices and coating–substrate interfaces; and electroactive coatings based mainly on polyaniline and polypyrrole, where protection is associated with passivation, redox mediation, and dopant-controlled inhibition. The findings indicate that corrosion-protective coatings have evolved through partially overlapping and increasingly integrated paradigms rather than through a single technological trajectory. This citation network analysis clarifies the transition from chromate replacement toward active, nanostructured, electroactive, and self-healing corrosion-protective systems. Full article

The laminin-derived nonapeptide CDPGYIGSR contains the bioactive YIGSR motif, historically associated with inhibition of tumor cell adhesion, invasion, angiogenesis, and laminin-receptor-mediated cell responses. Although these activities have often been attributed to the 37/67 kDa laminin receptor/RPSA axis, the molecular identity and organization of the laminin-binding receptor system remain debated. This uncertainty makes it essential to define the intrinsic conformational preferences of CDPGYIGSR in solution before assigning a unique receptor-bound structure. In this study, temperature replica-exchange molecular dynamics (T-REMD) simulations in explicit solvent are employed to characterize the solution conformational ensemble of CDPGYIGSR. Free energy landscape analysis, clustering, and structural descriptors reveal a predominant compact bend-like backbone arrangement, together with alternative low-lying conformational states within a heterogeneous ensemble. Rather than assuming a single bioactive conformation, the conformational ensemble is analyzed in terms of structural features that are consistent with available NMR observations and reported structure–activity relationships. Importantly, the most populated conformations in solution do not necessarily correspond to the bioactive state upon receptor binding. Instead, a subset of conformations sharing common structural motifs, including a central backbone bend and specific residue exposure patterns, may represent states compatible with receptor recognition. These results provide an ensemble-based structural framework that connects simulation-derived conformational motifs with available NMR observations and structure–activity data, supporting a recognition-compatible ensemble model in which compact preorganized states may contribute to receptor binding. Full article

Background/Objectives: Chlamydia trachomatis (CT) is a prevalent sexually transmitted pathogen associated with pelvic inflammatory disease, infertility, and has been proposed as a potential contributor to carcinogenesis through chronic inflammation and tissue remodeling. The molecular mechanisms triggered by CT infection in fallopian tube cellular contexts and their relevance to ovarian cancer transcriptomes remain incompletely understood. Methods: We analyzed GSE109428, profiling primary human fallopian tube mesenchymal cells infected with CT, to identify differentially expressed genes and characterize affected pathways using g:Profiler and STRING protein–protein association networks (confidence ≥ 0.7). To provide translational context, we computed ssGSEA scores in TCGA-OV for four signatures capturing IFN/ISG, TNF/NF-κB, NOD/innate immunity, and ECM programs, and evaluated inter-signature correlations and exploratory associations with overall survival (OS) and progression-free interval (PFI). Results: CT infection induced sustained inflammatory and interferon-associated transcriptional programs, with STRING networks highlighting cytokine hubs and a densely connected ISG module. Genes downregulated at 48 h post-infection (48-hpi) showed coherent enrichment for ECM organization and adhesion pathways. In TCGA-OV (n = 307), inflammatory and innate immune signatures co-occurred across tumors, with moderate correlations between TNF/NF-κB and NOD/innate (ρ = 0.591) and IFN/ISG and NOD/innate (ρ = 0.534). Exploratory survival analyses showed no significant associations with OS or PFI in Kaplan–Meier analyses or multivariable Cox models, including clinically adjusted and tumor microenvironment-adjusted specifications. Conclusions: CT infection induces sustained inflammatory and interferon-linked programs and coordinated repression of ECM networks in fallopian tube mesenchymal cells. Analogous immune transcriptional states co-occur in ovarian tumors, though the signatures evaluated did not yield robust prognostic signals in TCGA-OV. As this is an entirely in silico study without experimental validation, these findings should be treated as hypothesis-generating; thus, further mechanistic and experimental studies are warranted to clarify how CT infection-associated pathways may intersect with female tumorigenesis. Full article

Conventional wood connections rely on adhesives and metal fasteners, causing environmental concerns. Wood rotary welding offers an adhesive-free alternative. This study systematically investigated rotary welding of eucalyptus wood, evaluating process parameters’ effects on joint performance. Chemical and microstructural transformations at the welding interface were characterized using FT-IR, XPS, XRD, SEM, and TGA. Optimal parameters significantly enhanced connection strength compared to unwelded specimens. The welding process induced partial degradation of hemicellulose and cellulose, forming new chemical bonds and increasing carbonyl compounds. XRD revealed increased wood crystallinity, while SEM showed tighter interfaces with enhanced mechanical interlocking. TGA confirmed improved thermal stability at the welded interface. The findings demonstrate that rotary welding improves eucalyptus wood joint strength through combined chemical, thermal, and structural modifications, providing guidance for optimizing welding protocols in sustainable wood manufacturing. Full article

Biological mechanisms observed across diverse species—such as adhesion, color change, antifouling, and flexible protection—are functionally classified to inform a principle-based conceptual framework for the design of wearable environmental sensors. Existing wearable sensors are constrained by poor skin conformity, reliance on chemical adhesives, performance degradation in wet environments, dependency on external power, and low durability. In response, biological case studies are systematically organized into four functional categories—reversible and wet adhesion, power-free coloration, antifouling and antibacterial surface mechanisms, and compliant protective architectures—and hierarchically mapped to corresponding engineering layers. Rather than reporting experimental results, this framework outlines how biological mechanisms was translated into structured design principles that collectively address the core requirements of wearable sensors: skin compatibility, energy efficiency, fouling resistance, and durability under mechanical deformation. Unlike previous biomimetic surveys that primarily catalog natural phenomena, this work establishes a structured, function-oriented framework that explicitly connects biological strategies to multilayer sensor architectures aligned with Nature-based Solutions and the Global Biodiversity Framework. Ultimately, it clarifies a unique conceptual pathway for sustainable, biodiversity-informed engineering design. Full article

Background/Objectives: Soft tissues are essential for maintaining the function and long-term success of dental implants. In many cases, implant placement necessitates soft tissue augmentation procedures such as free gingival grafts (FGGs) or connective tissue grafts (CTGs) to restore lost gingival architecture. Nevertheless, a significant challenge associated with FGG and CTG is postoperative pain, largely due to morbidity at the palatal donor site. To address this issue, various approaches have been proposed to reduce patient discomfort and promote improved wound healing at the donor site. This study aimed to compare the effectiveness of four different methods for protecting the palatal donor site following free gingival graft harvesting. Methods: A total of 76 patients undergoing implant therapy with an indication for free gingival grafting were selected and divided into four groups based on the method used to protect the palatal donor site: an absorbable gelatin sponge secured with sutures (GS); an absorbable gelatin sponge with sutures and cyanoacrylate tissue adhesive (GS+CTA); oxidized regenerated cellulose combined with cyanoacrylate tissue adhesive (ORC+CTA); and an absorbable gelatin sponge covered with a flowable resin composite and stabilized with sutures (GS+FRC). The effectiveness of each method was evaluated in terms of postoperative pain, bleeding, and wound healing. Results: Although the differences in pain intensity among the groups were not statistically significant throughout the observation period (p > 0.05), the GS+FRC group consistently exhibited the lowest mean pain scores. No statistically significant differences were observed between the groups regarding the incidence of secondary bleeding. The highest mean wound healing rate was recorded in the GS+FRC group (75.95 ± 18.75%), whereas the ORC+CTA group demonstrated the lowest rate (43.66 ± 25.74%). Conclusions: The use of an absorbable gelatin sponge covered with a flowable resin composite and secured with sutures, despite the presented limitations, appears to be a promising approach for palatal wound protection. While this group consistently demonstrated the lowest mean pain scores, differences in pain intensity among the groups were not statistically significant. Nonetheless, it achieved the most favorable outcomes in terms of wound epithelialization. Full article

Much attention has been paid to the public health crisis that has resulted from the opioid epidemic. Given the high number of opioid users that are of childbearing age, the impact of utero exposure is a serious concern. Unfortunately, there is little knowledge regarding the consequences of opioid exposure during early development. While neurobehavioral effects of opioid exposure are well-documented, effects of exposure on embryogenesis remain largely unexplored. To address this gap in knowledge, we investigated the effects of oxycodone and fentanyl exposure on gene expression in zebrafish (Danio rerio) embryos using whole embryo RNA sequencing. Embryos were exposed to environmentally relevant (oxycodone HCl 10.6 ng/L and fentanyl citrate 0.629 ng/L) and therapeutically relevant doses (oxycodone HCl 35.14 μg/L and fentanyl citrate 3.14 μg/L) from 2 to 24 h post-fertilization (hpf), followed by another 24 h of opioid-free development. mRNA profiling at 48 hpf revealed dose- and drug-specific gene expression changes. Lower doses of oxycodone and fentanyl both induced more differentially expressed transcripts (DETs) than higher doses, potentially indicative of opioid receptor desensitization occurring at higher concentrations. In total, 892 DETs (corresponding to 866 genes) were identified across all conditions suggesting continued differential gene expression well after cessation of opioid exposure. Gene ontology analysis revealed changes in gene expression relating to extracellular matrix (ECM) organization, cell adhesion, and visual and nervous system formation. Key pathways include those involved in axon guidance, synapse formation, and ECM biosynthesis/remodeling, all of which have potential implications on neural connectivity and sensory development. These findings demonstrate that very early developmental exposure to opioids induces persistent transcriptomic changes which may have lasting implications for vertebrate cellular functions. Overall, these data provide insights into the molecular mechanisms of opioid-induced alterations during development. Full article

Among the many methods of joining different materials, gluing is characterized by its most specific nature. In comparison with, for example, welded, screwed, or overlapped connections, a glued connection depends on the largest number of factors. Many of them are related to the phenomenon of adhesion, which is complicated by definition. It has many shapes and forms, and its existence determines not only the durability of such a joint but also the possibility of its execution. Epoxy polymers are among the most commonly used adhesives. Their extremely good parameters can be easily modified by additives in the form of fillers. Compatibility between the filler and the adhesive allows for further improving the adhesive parameters in the glued joint. However, in order to effectively combine the adhesive and the filler, different, often specific mixing methods must be used. The following study presents the results obtained in an experimental research program, the aim of which was to increase the adhesion of epoxy resin to a properly prepared concrete substrate. As a method to increase the final adhesion, the addition of microsilica and carbon nanotubes in an experimentally determined amount was selected. The use of sonication as a mixing method together with cavitation allowed for improving the parameters which determine the final adhesion of the adhesive to concrete. The parameters which were selected to describe the course of changes in the adhesion of the adhesive to the concrete substrate were the viscosity, free surface energy, surface parameters, adhesion, and SEM images of the tested resin in various modification configurations. The obtained results make it possible to form stronger and more durable adhesive joints during the reinforcement of concrete structural elements using fiber-reinforced polymer (FRP) composites. Full article

The preparation of traditional wood-based panels mostly uses adhesives such as urea-formaldehyde resin and phenolic resin, which not only consumes petrochemical resources but also releases formaldehyde, posing potential health risks to the human body. Lignin, a natural adhesive in plant cells, is characterized by high reactivity, and it is expected to aid in the development of a new generation of green formaldehyde-free adhesives. However, current studies of lignin adhesives have revealed that while strides have been made in reducing formaldehyde emissions, its residual presence remains a concern, an issue which is compounded by inadequate water resistance. Dehydrogenated Polymer (DHP) has a lignin-like structure and good water resistance, offering a new option for the development of formaldehyde-free adhesives. In this paper, DHP and glucuronic acid were reacted with each other in a simulated hot-pressing environment to obtain DHP-glucuronic acid complex, and then the structure of the complex was characterized by infrared nuclear magnetic resonance to verify whether DHP can be efficiently connected with hemicellulose components under hot-pressing conditions. The results showed that the thermal condensation reaction of DHP and glucuronic acid can generate ester bonds at the Cα position in a simulated hot-pressing environment. This paper explores the thermal condensation mechanism of DHP and glucuronic acid, which is helpful for understanding the bonding process between adhesives and components of wood-based panels in the hot-pressing process, and provides key theoretical support for the design of more sustainable lignin adhesives. Full article

Material extrusion (MEX) additive manufacturing has successfully fabricated assembly-free structures composed of different materials processed in the same manufacturing cycle. Materials with different mechanical properties can be employed for the fabrication of bio-inspired structures (i.e., stiff materials connected to soft materials), which are appealing for many fields, such as bio-medical and soft robotics. In the present paper, process parameters and 3D printing strategies are presented to improve the interfacial adhesion between carbon fiber-reinforced nylon (CFPA) and thermoplastic polyurethane (TPU), which are extruded in the same manufacturing cycle using a multi-material MEX setup. To achieve our goal, a double cantilever beam (DCB) test was used to evaluate the mode I fracture toughness. The results show that the application of a heating gun (assembled near the nozzle) provides a statistically significant increase in mean fracture toughness energy from 12.3 kJ/m² to 33.4 kJ/m². The underlying mechanism driving this finding was further investigated by quantifying porosity at the multi-material interface using an X-ray computed tomography (CT) system, in addition to quantifying thermal history. The results show that using both bead ironing and the hot air gun during the printing process leads to a reduction of 24% in the average void volume fraction. The findings from the DCB test and X-ray CT analysis agree well with the polymer healing theory, in which an increased thermal history led to an increased fracture toughness at the multi-material interface. Moreover, this study considers the thermal history of each printed layer to correlate the measured debonding energy with results obtained using the reptation theory. Full article

Adhesive joints are some of the oldest inseparable connections, and were used much earlier than other non-separable connections (e.g., welded, soldered). Adhesives are widely used in the manufacture of vehicles, household appliances, aircraft, and medicine. One disadvantage of adhesive joints is their long bonding time (amounting, for example, to 72 h for polyurethane adhesives used in bus roof bonding), and another is their production of harmful waste. Tapes that are adhesive coated on both sides are increasingly being used to join parts during production. Such tapes have lower strength than traditional adhesives, but their bonding time is much shorter. In addition, the amount of waste remaining after production is minimized. Tapes, like adhesives, dampen vibrations well and seal the materials being joined. The purpose of this study was to evaluate the influence of selected factors on the quality of tape–steel sheet joints and to assess the possibility of testing acrylic tape–steel sheet joints using ultrasonic methods. It was found that the preparation of a surface for bonding has a significant effect on the quality of the joint, and it was confirmed that non-destructive evaluation of the quality of the tested joints by the ultrasonic method is possible. The decibel drop in the height of the first and fifth pulses obtained on the screen of the ultrasonic defectoscope was proposed as an ultrasonic measure. The highest-quality joints were characterized by a measure in the range of 12 dB, lower-quality areas of about 8 dB, and tape-free areas of about 5 dB. At the same time, it was noted that in the case of proper surface preparation, there was cohesive failure of the joint during breakage. Full article

The use of free gingival graft (FGG) and connective tissue graft (CTG) from the palate are among the most predictable periodontal and peri-implant plastic surgery procedures. However, palatal harvesting causes severe discomfort in the palatal area in patients undergoing harvesting. The aim of this umbrella review is to evaluate which products or techniques can result in fewer side effects and less morbidity in patients. Systematic reviews, with meta-analysis or not, about postoperative pain and wound healing in patients undergoing surgery to remove a free gingival graft or connective tissue graft from the palatal region, published only in the English language, were electronically searched for on BioMed Central, Scopus, MEDLINE/PubMed, the Cochrane library databases, and PROSPERO register. Of 1153 titles, only 7 articles were included in this review. The reviews included suggest that the more effective interventions for patient-reported outcomes, particularly for pain management, are cyanoacrylate adhesives, platelet-rich fibrin, hyaluronic acid, and the use of palatal stents. Low-level laser therapy also demonstrated good results in palatal wound healing speed after FGG procedures. Also, topical agents were also described. Future studies and more high-quality randomized clinical trials are needed to provide clear descriptions and standardized procedures of interventions to obtain clear results. Full article

As a sustainable construction material, timber is more promoted than steel, concrete, and aluminum nowadays. The building industry benefits from using timber based on several perspectives, including decarbonization, improved energy efficiency, and easier recycling and disposal processes. The cross-laminated timber (CLT) panel is one of the widely utilized engineered wood products in construction for floors, which is an ideal alternative option for replacing reinforced concrete. One single CLT panel has an outstanding flexural behavior. However, CLT cannot be extended independently without external connections, which are normally made of steel. This article proposes two innovative adhesive-free edge connections made of timber, the double surface (DS) and half-lapped (HL) connections. These connections were designed to connect two CLT panels along their weak direction. Parametric studies consisting of twenty models were conducted on the proposed edge connections to investigate the effects of different factors and the flexural behavior of CLT panels with these edge connections under a four-point bending test. Numerical simulations of all the models were done in the current study by using ABAQUS 2022. Furthermore, the employed material properties and other relevant inputs (VUSDFLD subroutines, time steps, meshes, etc.) of the numerical models were validated through existing experiments. The results demonstrated that the maximum and minimum load capacities among the studied models were 6.23 kN and 0.35 kN, respectively. The load–displacement responses, strain, stress, and defection distributions were collected and analyzed, as well as their failure modes. It was revealed that the CLT panels’ load capacity was distinctly improved due to the increment of the connectors’ number (55.05%) and horizontal length (80.81%), which also reinforced the stability. Based on the findings, it was indicated that adhesive-free timber connections could be used for CLT panels in buildings and replace traditional construction materials, having profound potential for improving buildings’ sustainability and energy efficiency. Full article

Various artificial materials and facilities are sources of microplastics, including artificial turf sports fields. In artificial turf fields, polyethylene fibers are attached to a basal cloth with adhesives. In the present study, we investigated whether the fibers in the field were detached from the basal cloth or torn in the field, and whether they moved to the surrounding ditches that were connected to sewage pipes. In the field, we collected fibers shorter in length compared to the original and these were free from basal cloth, indicating the tearing of the fibers due to players’ activities. We also collected fibers from the ditches, which indicated a migration of the fibers from the field into the ditches. These results suggest that the fibers in ditches could enter sewage treatment plants and be released into the aquatic environment as microplastics. We also examined whether goldfish, Carassius auratus, ingested these fibers, and observed that the fish ingested them with feed while the fish did not without feed. These results indicate that the fiber ingestion by the fish occurred unintentionally when they swallowed their feed. The present study demonstrated that artificial turf fibers in sports fields could turn into microplastics that can be ingested by wild fishes. Full article