Search Results (2,173)

In this work, we investigated the use of a piezoelectric flexible device for energy harvesting. The main goal of the study was to fill the nanostructured pores of anodic aluminum oxide (AAO) films with piezoelectric polymer (PVDF-TrFE) via a modified conventional screen printing technique using blade printing. In this way, it is possible to obtain a composite from nanostructured thin films of polymer nanorods that shows improved charge generation ability compared to other non-nanostructured composites or pure (non-composite) aluminum with similar dimensions. This behavior is due to the effect of the highly developed surface of the material used to fill in the AAO nanopore template and its ability to withstand the application of higher mechanical loads to the structured piezoelectric material during deformation. The contact blade print filling technique can produce nanostructured piezoelectric polymer films with precise geometric parameters in terms of thickness and nanorod diameters, at around 200 nm, and a length of 12 μm. At a low frequency of 17 Hz, the highest root-mean-square (RMS) voltage generated using the nanostructured AAO/PVDF-TrFE sample with aluminum electrodes was around 395 mV. At high frequencies above 1700 Hz, the highest RMS voltage generated using the nanostructured AAO/PVDF-TrFE sample with gold electrodes was around 680 mV. The RMS voltage generated using a uniform (non-nanostructured) layer of PVDF-TrFE was 15% lower across the whole frequency range. Full article

Background/objectives: Cellular senescence is a hallmark of aging that contributes to tissue dysfunction and age-related diseases. This process is characterized by the activation of the cyclin-dependent kinase inhibitor p16^INK4A and the secretion of pro-inflammatory factors collectively known as the senescence-associated secretory phenotype (SASP). In this study, we used human lung-derived cells, including A549 and IMR90 fibroblasts, to identify bioactive compounds from the roots of Liquidambar formosana that suppress p16^INK4A activity and attenuate SASP expression. Methods: Bioactivity-guided isolation was performed to obtain target compounds. The structures of the new compounds were elucidated using extensive 1D and 2D NMR spectroscopic analyses as well as high-resolution mass spectrometry. All isolated compounds were evaluated for their ability to inhibit p16^INK4A, a key regulator of the cell cycle and an important tumor suppressor protein. Results: Two previously undescribed monoterpenoids (1 and 2), characterized as cinnamic acid esters with a monoterpene-derived core, were isolated from the roots of L. formosana, along with six known compounds (3–8). Notably, compound 3 exhibited promising inhibition of p16^INK4A with an IC₅₀ value of 3.9 μM. Furthermore, this compound attenuated the senescence phenotype, as demonstrated by β-galactosidase staining and RT-qPCR analysis. This represents the first report identifying bioactive monoterpenoids from L. formosana that inhibit aging-related biomarkers such as p16^INK4A. Conclusions: These results suggest that cinnamic acid-conjugated monoterpenoids may serve as interesting lead structures for the development of agents targeting the p16^INK4A pathway for the treatment of aging-associated diseases. Further studies will be required to clarify the mechanisms of action of this compound and to evaluate its in vivo efficacy. Full article

Pathological vascular remodeling—central to restenosis, atherosclerosis, and vasculo-proliferative diseases—depends on the phenotypic switching of vascular smooth muscle cells (VSMCs) from a quiescent, contractile state to a synthetic, proliferative program. Although the receptor tyrosine kinase c-Kit is implicated in proliferation, migration, and tissue repair, its role in VSMC plasticity has yet to be fully understood. Using c-Kit haploinsufficient mice subjected to right carotid artery ligation (CAL) and primary aortic VSMC cultures, we show that c-Kit is required for the contractile-to-synthetic transition. In vitro, c-Kit haploinsufficiency halved c-Kit expression, reduced 5-bromo-2′-deoxyuridine (BrdU) incorporation, and blunted platelet-derived growth factor BB (PDGF-BB)-induced repression of contractile genes. c-Kit–deficient VSMCs exhibited a senescence program with increased p16^INK4a/p21 expression and upregulated senescence-associated secretory phenotype (SASP) mediators. RNA-Seq of carotid arteries 7 days post-ligation revealed that wild-type arteries activated cell-cycle pathways and suppressed contractile signatures, whereas c-Kit-deficient carotid arteries failed to fully engage proliferative programs and instead maintained contractile gene expression. At 28 days post CAL in vivo, c-Kit haploinsufficiency produced markedly reduced neointima, fewer Ki67+ VSMCs, more p16^INK4a+ cells, and impaired re-endothelialization. Because progenitor-to-VSMC differentiation contributes to remodeling, we tested adult cardiac stem/progenitor cells (CSCs) as a model system of adult progenitor differentiation. Wild-type CSCs efficiently generated induced VSMCs (iVSMCs) with appropriate smooth-muscle gene upregulation; c-Kit–deficient rarely did so. Restoring c-Kit with a BAC transgene rescued both the smooth-muscle differentiation and proliferative competence of c-Kit-deficient iVSMCs. Collectively, our data identified c-Kit as a gatekeeper of reparative VSMC plasticity. Adequate c-Kit enables progenitor-to-VSMC commitment and the expansion of newly formed VSMCs while permitting injury-induced proliferation and matrix synthesis; reduced c-Kit locks cells in a hypercontractile, senescence-prone state and limits neointima formation. Modulating the c-Kit axis may therefore offer a strategy to fine-tune vascular repair while mitigating pathological remodeling. Full article

Background/Objective: Cellular senescence is increasingly recognized as a key mechanism underlying sarcopenia, an age-related muscle disorder with no effective therapeutic. 6,4′-Dihydroxy-7-methoxyflavanone (DMF), a flavonoid isolated from Dalbergia odorifera T. Chen, has shown anti-senescence potential. This study aimed to investigate the protective effects of DMF against myoblasts senescence and elucidate the underlying molecular mechanisms. Method: A cellular model of senescence was established in C2C12 myoblasts using D-galactose (D-gal). The effects of DMF pretreatment were evaluated by assessing senescence phenotypes, myogenic differentiation, and mitochondrial function. The role of Sirtuin3 (SIRT3) was confirmed using siRNA-mediated knockdown. Results: DMF Pre-treatment effectively attenuated D-gal-induced senescence, as indicated by restored proliferation, reduced senescence-associated β-galactosidase activity, decreased DNA damage, and the downregulation of p53, p21^Cip1/WAF1 and p16^INK4a. Furthermore, DMF rescued myogenic differentiation capacity, enhancing the expression of Myoblast determination protein 1, Myogenin, Myosin heavy chain and Muscle-specific regulatory factor 4, and promoting myotube formation. Mechanistically, DMF was identified as a SIRT3 activator. It enhanced SIRT3 expression and activity, leading to the deacetylation and activation of the mitochondrial antioxidant enzyme superoxide dismutase 2. This consequently reduced mitochondrial reactive oxygen species, improved mitochondrial membrane potential and ATP production, and suppressed the NF-κB pathway by inhibiting IκBα phosphorylation and p65 acetylation/nuclear translocation. Crucially, all the beneficial effects of DMF—including oxidative stress reduction, mitochondrial functional recovery, anti-inflammatory action, and ultimately, the attenuation of senescence and improvement of myogenesis—were abolished upon SIRT3 knockdown. Conclusions: Our findings demonstrate that DMF alleviates myoblasts senescence and promotes myogenic differentiation by activating the SIRT3-SOD2 pathway, thereby reducing oxidative stress and NF-κB-driven inflammation responses. DMF emerges as a promising therapeutic candidate for sarcopenia. Full article

The protection and dissemination of cultural heritage in the digital age are confronted with dual problems of fragmented cultural narratives and insufficient public participation, which have now become a major bottleneck in realizing the value of cultural heritage. The rise of artificial intelligence technology nowadays offers an unprecedented opportunity to address this challenge. This study proposes a framework that combines artificial intelligence to tackle this issue, using the UNESCO World Heritage site, Kaiping Diaolou, as a case study. The methodology integrates AIGC tools such as Stable Diffusion and GPT-4 with traditional 3D modeling and digital twin technologies, aiming to go beyond traditional “photorealistic” replication by creating ink-wash stylized models with cultural resonance and artistic expressiveness, while providing immersive gamified experiences in virtual and augmented reality environments. A mixed-methods evaluation combining ratings from 6 experts and surveys from 122 participants confirms that the framework significantly improves work efficiency—modeling time is reduced from several hours to an average of 48 min, with a 60% increase in efficiency. More importantly, the gamified narrative generated by AI received a high engagement score of 4.2 (out of 5.0) among the 18 to 25 age group. The study also reveals a significant digital divide: users over 36 years old rated usability 35% lower than younger participants. The framework effectively lowers the technological threshold, allowing non-expert users to meet 70% of usability standards after brief training. This study ultimately validates an innovative framework that combines scalability and efficiency, offering an empirically tested practical solution for the deep, sustainable revitalization and public engagement of cultural heritage. Full article

Additive manufacturing methods can constitute a valuable alternative to conventional production techniques for components used in the heavy industry, particularly in foundry applications. This innovative manufacturing approach enables an expanded product portfolio as well as higher precision and geometrical complexity of ceramic components. One additive technology applicable to ceramic processing is robocasting, classified within the direct ink writing (DIW) family. In this method, a semi-fluid ceramic paste is extruded to build the part layer by layer; the shaped green body is subsequently fired (sintered) to attain its final functional properties. This study presents the results of materials characterization of printed ceramic filters, encompassing phase composition analysis, density measurements, three-point bending strength testing, hardness, and microstructural examination. The investigations demonstrated that the oxide ceramic Al₂O₃ processed by the modern robocasting method exhibits mechanical performance at a comparably high level relative to classical manufacturing routes (slip casting, ceramic injection molding, dry pressing). Moreover, the porosity results indicate that 3D printing technology enables lower post-sintering porosity. Full article

To address limitations such as cleaning difficulties or secondary contamination/damage of cultural relics caused by the uncontrollable diffusion of water/cleaning agent/dirty liquids during the cleaning process in traditional cleaning methods, this study, using cotton textiles as an example, systematically investigated the cleaning efficacy of four in situ methods (blank gel, cleaning gel, ultrasonic emulsification, and gel + ultrasonic emulsification synergistic cleaning) on eight types of stains, including sand, clay, rust, blood, ink, oil, and mixed solid/liquid stains. Building upon this, this study proposed an efficient, targeted, in situ, and controllable cleaning strategy tailored for fragile, stained textile relics. Results demonstrated that, regardless of the stain type, the synergistic cleaning method of G+U (gel poultice + ultrasonic emulsification) consistently outperformed the cleaning methods of blank gel poultice, cleaning gel poultice, and ultrasonic emulsification. Furthermore, the gel loaded with cleaning agents was always more effective than the blank gel (unloaded cleaning agents). The poultice methods of blank gel and cleaning gel were better suited for solid stains, while the ultrasonic emulsification cleaning method was more effective for liquid stains. Meanwhile, it was also found that the optimal cleaning method proposed in this study (the G+U synergistic cleaning method) was a cleaning method that restricted the cleaning agent within the gel network/emulsion system, and utilized the porous network physical structure of gel, the chemical action of emulsion’s wetting/dissolving dirt, and the cavitation synergistic effect of ultrasound to achieve the targeted removal of contaminants from relics’ surfaces. Crucially, the cleaning process of G+U also had the characteristics of controlling the cleaning area at the designated position and effectively regulating the diffusion rate of the cleaning solution within the treatment zone, as well as the reaction intensity. Therefore, the proposed optimal (the synergistic cleaning method of G+U) cleaning method conforms to the significant implementation of the “minimal intervention and maximal preservation” principle in modern cultural heritage conservation. Consequently, the synergistic cleaning method of G+U holds promise for practical application in artifact cleaning work. Full article

Solution combustion-synthesized BaAl₂O₄: Eu²⁺, Nd³⁺, and Pr³⁺ blue–green long-afterglow phosphors are prepared and systematically investigated. First, XRD confirms the BaAl₂O₄ host and screens for trace residual features. SEM reveals the agglomerated granular morphology typical of combustion products. XPS verifies the valence states (Eu²⁺, Nd³⁺, Pr³⁺) and the chemical environment of the host lattice. UV-Vis diffuse reflectance spectra, transformed via the Kubelka–Munk function and analyzed using Tauc plots (indirect-allowed), indicate a wide band gap of the BaAl₂O₄ host with small, systematic shifts upon Nd³⁺/Pr³⁺ co-doping. PL measurements show Eu²⁺ 4f–5d emission and co-dopant-assisted excitation/defect pathways without altering the Eu²⁺ emission band shape. Afterglow lifetime and decay analyses correlate trap depth/distribution with the extended persistence. Finally, we demonstrate anti-counterfeiting by (i) snowflake printing and (ii) a binary 3 × 3 grid printed with two afterglow inks of different lifetimes to realize multi-level authentication. The sequential evidence links structure, chemistry, optical absorption, carrier trapping, and practical readout, providing a coherent basis for performance enhancement and application. Full article

(Background) Retinoblastoma is the most common intraocular malignancy in childhood, primarily caused by mutations in the RB1 gene. However, increasing evidence highlights the significant role of epigenetic mechanisms, particularly DNA methylation and histone acetylation, in tumor initiation and progression. This review aims to summarize and critically assess recent findings on how DNA methylation and histone acetylation contribute to the pathogenesis of retinoblastoma, and to explore their potential role as diagnostic biomarkers and therapeutic targets. (Methods) We searched the databases PubMed, Scopus, and ScienceDirect following PRISMA guidelines. Eligible studies were English-language, open-access articles published within the last ten years, including cohort studies, research articles, and case reports. After rigorous screening, 18 studies were included in the final analysis. (Results) Aberrant DNA methylation was found to inactivate tumor suppressor genes (RB1, RASSF1A, p16INK4A, MGMT) and promote oncogenesis through hypermethylation of regulatory elements. Similarly, histone acetylation’s dysregulation contributed to chromatin remodeling and overexpression of oncogenic factors such as SYK, GALNT8, and lincRNA-ROR. Elevated histone deacetylase (HDAC) activity was also linked to tumor cell proliferation, metastasis, and treatment resistance. Epigenetic inhibitors targeting these pathways demonstrated promising therapeutic potential. (Conclusions) DNA methylation and histone acetylation play a crucial role in the epigenetic regulation of genes implicated in retinoblastoma. Their dysregulation promotes tumorigenesis, and targeting these mechanisms represents a promising avenue for novel diagnostic and therapeutic strategies in pediatric oncology. Full article

Hydrogel/electrospun polymer nanofiber composites (HENC) integrate the advantages of both components. Hydrogels provide high water content, biocompatibility, and tunable drug release, while electrospun nanofibers offer a high surface area, loading capacity, customizable morphology, and opportunities for functionalization. Nanofibers can also be incorporated into hydrogels as 3D-printable inks. Together, these features create biomimetic composites that modulate drug release and mimic native tissues. This article reviews electrospinning fundamentals, limitations, preparation methods for HENC, and their applications in drug delivery, as well as future perspectives for developing advanced functional materials with improved therapeutic efficacy, controlled release kinetics, and broad biomedical adaptability. Full article

Residual-free eutectic Au80Sn20 soldering is still the dominant assembly technology for optoelectronic devices such as high-power lasers, LEDs, and photodiodes. Due to the high cost of gold, alternatives are desirable. This paper investigates the thermal performance of copper-based sintering for optoelectronic submodules on first and second level to obtain thermally efficient thin bondlines. Sintered interconnects obtained by a new particle-free copper ink, based on complexed copper salt, are compared with copper flake and silver nanoparticle sintered interconnects and benchmarked against AuSn solder interconnects. The copper ink is dispensed and predried at 130 °C to facilitate in situ generation of Cu nanoparticles by thermal decomposition of the metal salt before sintering. Submounts are then sintered at 275 °C for 15 min under nitrogen with 30 MPa pressure, forming uniform 2–5 µm copper layers achieving shear strengths above 31 MPa. Unpackaged LEDs are bonded on first level using the copper ink but applying only 10 MPa to avoid damaging the semiconductor dies. Thermal performance is evaluated via transient thermal analysis. Results show that copper ink interfaces approach the performance of thin AuSn joints and match silver interconnects at second level. However, at first level, AuSn and sintered interconnects of commercial silver and copper pastes remained superior due to the relative inhomogeneous thickness of the thin Cu copper layer after predrying, requiring higher bonding pressure to equalize surface inhomogeneities. Full article

Inkjet printing enables contactless deposition onto fragile substrates for printed energy-storage devices and supports flexible batteries and supercapacitors with reduced material use. This review examines multilayer and interdigital architectures and analyzes how ink rheology, droplet formation, colloidal interactions, and the printability window govern performance. For batteries, reported inkjet-printed electrodes commonly deliver capacities of ~110–150 mAh g⁻¹ for oxide cathodes at C/2–1 C, with coulombic efficiency ≥98% and stability over 10²–10³ cycles; silicon anodes reach ~1.0–2.0 Ah g⁻¹ with efficiency approaching 99% under stepwise formation. Typical current densities are ~0.5–5 mA cm⁻² depending on areal loading, and multilayer designs with optimized drying and parameter tuning can yield rate and discharge behavior comparable to cast films. For supercapacitors, inkjet-printed microdevices report volumetric capacitances in the mid-hundreds of F cm⁻³, translating to ~9–34 mWh cm⁻³ and ~0.25–0.41 W cm⁻³, with 80–95% retention after 10,000 cycles and coulombic efficiency near 99%. In solid-state configurations, stability is enhanced, although often accompanied by reduced areal capacitance. Although solids loading is lower than in screen printing, precise material placement together with thermal or photonic sintering enables competitive capacity, rate capability, and cycle life while minimizing waste. The review consolidates practical guidance on ink formulation, printability, and defect control and outlines opportunities in greener chemistries, oxidation-resistant metallic systems, and scalable high-throughput printing. Full article

Cellular senescence is a heterogeneous and dynamic state characterised by stable proliferation arrest, macromolecular damage and metabolic remodelling. Although markers such as SA-β-galactosidase staining, yH2AX foci and p53 activation are widely used as de facto standards, they are imperfect and differ in terms of sensitivity, specificity and dependence on context. We present a multifactorial imaging platform integrating scanning electron, flow cytometry and high-resolution confocal microscopy. This allows us to identify senescence phenotypes in three in vitro models: replicative ageing via serial passaging; dose-graded genotoxic stress under serum deprivation; and primary fibroblasts from young and elderly donors. We present a multimodal imaging framework to characterise senescence-associated phenotypes by integrating LysoTracker and MitoTracker microscopy and SA-β-gal/FACS, p16INK4a immunostaining provides independent confirmation of proliferative arrest. Combined nutrient deprivation and genotoxic challenge elicited the most pronounced and concordant organelle alterations relative to single stressors, aligning with age-donor differences. Our approach integrates structural and functional readouts across modalities, reducing the impact of phenotypic heterogeneity and providing reproducible multiparametric endpoints. Although the framework focuses on a robustly validated panel of phenotypes, it is extensible by nature and sensitive to distributional shifts. This allows both drug-specific redistribution of established markers and the emergence of atypical or transient phenotypes to be detected. This flexibility renders the platform suitable for comparative studies and the screening of senolytics and geroprotectors, as well as for refining the evolving landscape of senescence-associated states. Full article

Cellular senescence, a state of stable cell cycle arrest accompanied by a complex senescence-associated secretory phenotype (SASP), is a fundamental biological process implicated as a key driver of lung aging and lung age-related diseases (LARDs). This review provides a comprehensive overview of the rapidly evolving field of senotyping based on cellular heterogeneity in lung development and aging in health and disease. It also delves into the molecular mechanisms driving senescence and SASP production, highlighting pathways such as p53/p21, p16^INK4a/RB, mTOR, and p38 MAPK as therapeutic targets. The involvement of various novel SASP proteins, such as GDP15, cytokines/chemokines, growth factors, and DNA damage response proteins. We further highlight the effectiveness of senotherapeutics in mitigating the detrimental effects of senescent cell (SnC) accumulation within the lungs. It also outlines two main therapeutic approaches: senolytics, which selectively trigger apoptosis in SnCs, and senomorphics (also known as senostatics), which mitigate the detrimental effects of the SASP without necessarily removing the senescent cells. Various classes of senolytic and senomorphic drugs are currently in clinical trials including natural products (e.g., quercetin, fisetin, resveratrol) and repurposed drugs (e.g., dasatinib, navitoclax, metformin, rapamycin) that has demonstrated therapeutic promise in improving tissue function, alleviating LARDs, and extending health span. We discuss the future of these strategies in lung research and further elaborate upon the usability of novel approaches including HSP90 inhibitors, senolytic CAR-T cells, Antibody drug conjugate and galactose-modified prodrugs in influencing the field of personalized medicine in future. Overall, this comprehensive review highlights the progress made so far and the challenges faced in the field of cellular senescence including SnC heterogeneity, states of senescence, senotyping, immunosenescence, drug delivery, target specificity, long-term safety, and the need for robust cell-based biomarkers. Future perspectives, such as advanced delivery systems, and combination therapies, are considered critical for translating the potential of senotherapeutics into effective clinical applications for age-related pulmonary diseases/conditions. Full article

A polyamidoamine-based hydrogel (H-M-GLY) and its montmorillonite-based composite (H-M-GLY/MMT) were studied as selective cleaning materials for cultural heritage conservation. H-M-GLY was synthesized from a glycine-based polyamidoamine oligomer with acrylamide terminals (M-GLY) through radical polymerization at pH 7.3 and had a basic character. The M-GLY oligomer was in turn synthesized from N,N′-methylenebisacrylamide and glycine in a 1:0.85 molar ratio. H-M-GLY/MMT was obtained by cross-linking a 1:0.1—weight ratio—M-GLY/MMT mixture at pH 4.0, to promote polyamidoamine-MMT interaction. The composite hydrogel absorbed less water than the plain hydrogel and proved tougher, due to montmorillonite’s electrostatic interactions with the positively charged M-GLY units. Scanning electron microscopic analysis showed that MMT was uniformly dispersed throughout the hydrogel. Both hydrogels were subjected to ink bleeding tests on papers written with either iron gall or India ink. Microscopic observation revealed neither bleeding nor release of hydrogel fragments. Being basic, H-M-GLY successfully deacidified the surface of aged paper. H-M-GLY/MMT, swollen in a 1:9 ethanol/water solution, was found to be effective in removing wax, known to trap carbonaceous particles and form dark stains on artistic artifacts. This study demonstrates the great potential of polyamidoamine-based hydrogels as versatile selective cleaning systems for cellulosic and other cultural heritage materials. Full article