Search Results (245)

Rapid rewarming is the most conventional and primary treatment for frostbite, yet effective adjunctive strategies remain absent. Conventional wound dressings, such as therapeutic hydrogels, tend to freeze and lack the necessary rewarming ability, rendering them unsuitable for direct application. Herein, we engineered an environmentally tolerant photothermal hydrogel, named 5A-Gel, featuring anti-swelling, anti-pressure, antioxidant, anti-freezing, and anti-drying capacities, for the treatment of frostbite. 5A-Gel was formed via dynamic crosslinking between gelatin and tea polyphenols in a glycerol/water solvent system. The incorporation of glycerol endowed the hydrogel with superior anti-swelling, anti-freezing, and anti-drying performance (remaining flexible at −20 °C and 37 °C for at least 60 days), along with concentration-dependent antioxidant activity due to tea polyphenols. Furthermore, 5A-Gel exhibited excellent photothermal effects, maintaining stable temperature and softness under 808 nm laser irradiation with robust cyclic durability. In addition, 5A-Gel showed slow degradability, excellent hemocompatibility, and favorable in vivo biosafety. Functionally, in a mouse frostbite wound model, photothermal rewarming therapy using 5A-Gel markedly expedited frostbite healing, promoting re-epithelialization, enhancing collagen deposition, alleviating inflammatory response, and stimulating neovascularization. Therefore, the as-prepared 5A-Gel serves as a competent therapeutic platform for in situ frostbite treatment and offers innovative principles for the rational engineering of high-performance hydrogel systems targeting frostbite tissue injuries. Full article

Sterilization is essential for hydrogel-based biomaterials, but it can also determine the final material state. This study used ionically crosslinked alginate hydrogels as a model system to evaluate sterilization as a coupled process linking microbial inactivation and hydrogel structural reorganization. Steam sterilization, gamma irradiation, ethylene oxide (EtO), ultraviolet (UV) irradiation, and high hydrostatic pressure (HHP) treatment were assessed within the same model system. Microbiological effectiveness was assessed using surface- and matrix-associated contamination models, while structural responses were evaluated by rheology, dimensional changes, and swelling behavior. Steam sterilization, gamma irradiation, EtO, and selected HHP conditions resulted in no detectable microbial growth under the tested conditions, whereas UV irradiation was insufficient to eliminate detectable growth from matrix-associated contamination. However, microbiologically effective treatments produced distinct material profiles. Steam generated a compact and stiff hydrogel state, gamma irradiation produced softened but deformation-tolerant networks, EtO caused pronounced dimensional alteration and high deformability, and HHP produced softened, water-accessible hydrogels with parameter-dependent responses. These findings show that sterilization method selection should integrate microbial inactivation with the final structural state required for application-specific hydrogel performance. Full article

Injectable hydrogels have attracted substantial and rapidly growing interest due to their ability to be administered into cavities of any shape and provide local therapeutic treatment. This study reports the synthesis and characterization of thermosensitive microgels and hydrogels obtained via photoinitiated copolymerization of methacrylated gelatin (GN-MA) and N-isopropylacrylamide (NIPAM) in the absence and presence of N,N′-methylenebisacrylamide (MBA). The effects of monomer concentration, crosslinker content (MBA), and irradiation time on product yield, grafted chain length, and material properties were systematically investigated. Depending on the polymerization conditions, microgel samples exhibited hydrodynamic diameters in the range of 354–1022 nm at 20 °C, which decreased to 183–308 nm upon heating to 40 °C. Freeze-drying of the microgel dispersions resulted in the formation of a porous sponge-like structure with pore sizes of 50–90 µm. Rheological studies of the hydrogel properties demonstrated evident thermoresponsive behavior, with storage moduli (G′) ranging from 20 to 600 Pa, matching the mechanics of certain soft tissues. The hydrogels showed high equilibrium swelling capacity at 20 °C, which was reduced at 40 °C, as well as temperature-dependent moxifloxacin release (38–88% over 6 days) and excellent biocompatibility (>85% cell viability) with human skin fibroblasts. These findings make them promising for biomedical applications such as postoperative cavity filling and local drug delivery. Full article

Ectomyelois ceratoniae (Zeller), the date moth, is a major pest of date palm (Phoenix dactylifera L.), responsible for severe post-harvest losses in arid and Mediterranean regions. The Sterile Insect Technique (SIT) is an environmentally friendly control method whose effectiveness depends on selecting irradiation doses that ensure sterility while preserving insect quality. This study evaluated the histopathological effects of ⁶⁰Co gamma irradiation on the digestive system of fifth-instar larvae of E. ceratoniae. Larvae were exposed to doses of 0 (control), 250, 300, 350, and 450 Gy, and the mesenteron, proctodeum, and Malpighian tubules were analyzed using Mallory’s trichrome staining. Quantitative measurements included epithelial thickness, intestinal stem cell density, Malpighian tubule diameter, and a histological integrity index. Gamma irradiation induced pronounced dose-dependent alterations. These included thinning and disorganization of the intestinal epithelium, a marked reduction in stem cell density, swelling of Malpighian tubules, and a progressive loss of tissue integrity. Severe degeneration and functional collapse of digestive tissues were observed at doses ≥ 350 Gy. The results indicate that 300–350 Gy represents a critical irradiation range inducing irreversible digestive damage compatible with effective sterilization. These findings provide histopathological reference criteria for optimizing dose selection and quality control in SIT programs targeting E. ceratoniae. Full article

Zirconium carbide (ZrC) is a leading candidate for advanced nuclear reactor components due to its ultra-high melting point, thermomechanical stability, and low neutron absorption. However, its irradiation damage behavior and mechanism remains underexplored. In this work, dense pressureless-sintered ZrC ceramics with low-neutron-absorption MoSi₂ additives were irradiated with 500 keV He²⁺ ions at room temperature to peak damage levels of 0.30, 1.49, and 2.97 dpa. The changes in their microstructure, bonding states, and property were analyzed via TEM, GIXRD, Raman spectroscopy, nanoindentation, and TDTR. ZrC retained crystallinity regardless of high-density black-spot defects, while MoSi₂ exhibited severe amorphization and swelling. Lattice expansion and partial Zr-C bond breakage with C-C bond formation were confirmed, with maximum hardening at 1.49 dpa and significant elastic modulus reduction at 2.97 dpa. Thermal conductivity decreased modestly and showed minimal dose dependence, indicating a saturation effect. These results elucidate defect evolution in pressureless-sintered ZrC-MoSi₂ ceramics and support its application in high-irradiation nuclear environments. Full article

The development of fusion technology requires materials that can withstand heat, erosion, and activation at the edge of fusion plasma. Thanks to its high melting point, superior thermal conductivity, and excellent resistance to sputtering and retention, tungsten (W) has been regarded as the leading candidate for the plasma-facing materials (PFMs) of the main chambers and divertors in controlled thermonuclear fusion reactors. Nevertheless, W-PFMs are prone to complex severe surface deterioration under extreme service conditions during operation in fusion reactors. This includes physical/chemical sputtering, which results in material loss and plasma contamination; He-induced blistering and fuzz formation, which reduce thermal conductivity by several orders of magnitude; thermal fatigue cracking caused by transient loads; and neutron irradiation embrittlement, which leads to hardening, swelling, and loss of ductility. To overcome these issues while maintaining core thermophysical properties, protective surface layers have been fabricated primarily via chemical vapor deposition (CVD), physical vapor deposition (PVD), and spray and plasma-based surface modification technologies. This review assesses the recent progress in the fabrication of protective surface layers on W for PFM application in fusion reactors from a technical perspective, thereby offering new insights that advance the feasibility of fusion reactors and accelerating the practical realization of sustainable fusion energy systems. Full article

This study examines the impact of alkaline treatment on hydrogels composed of acrylic acid (AAc), sodium alginate (SA), and poly(ethylene oxide) (PEO), produced via 5.5 MeV electron beam irradiation, emphasizing swelling behavior and functional performance. Hydrogels were treated with NaOH (0.25 M and 0.50 M) to modulate biodegradability, water retention capacity, and water retention ratio. The materials were characterized in terms of structural, morphological, thermal, and physicochemical properties using FTIR, SEM, and TGA/DSC, along with evaluations of gel fraction, cross-linking density, mesh size, porosity, swelling kinetics, and water retention. FTIR confirmed carboxyl group ionization and polymer chain reorganization, while SEM revealed structural changes, rougher surfaces, and larger pores that facilitate water uptake. Thermal stability of the hydrogels increased, with the T-onset rising from 236 °C in the untreated samples to 451 °C after alkaline treatment. Treatment with 0.25 M NaOH enhanced mesh size (127.97 ± 4.05 nm), porosity (99.74 ± 0.05%), and swelling capacity (428 ± 14 g/g), whereas 0.50 M induced partial degradation and reduced swelling. Despite a significant increase in degradability (>39.49 ± 1.94% after 28 days), treated hydrogels maintained functional performance, showing accelerated water uptake and improved rainwater retention. Overall, alkaline treatment enables tunable structural and functional modifications, optimizing hydrogel performance for agricultural water management. Full article

Breast lymphedema is characterized by skin thickening/swelling of the breast and is common following partial mastectomy and radiation. Oncoplastic reduction performed during partial mastectomy removes additional breast tissue compared to partial mastectomy alone to optimize breast contour. Recent literature has suggested oncoplastic reduction in patients with macromastia undergoing breast-conservation surgery is protective of breast lymphedema, decreasing rates from 11% to 3%. The purpose of this study is to assess the rates of breast lymphedema after partial mastectomy and oncoplastic reduction and identify risk factors. A single-center retrospective study was performed of breast cancer patients following partial mastectomy and oncoplastic reduction (2018–2023). Patients underwent contralateral breast reduction for symmetry. Breast lymphedema was assessed. Demographics data and risk factors were evaluated. This study included 158 patients who underwent partial mastectomy and oncoplastic reduction. Breast lymphedema incidence was 3.2% (5/158). Including contralateral non-cancerous breast symmetry reduction, lymphedema occurred in 3.6% (5/140) of irradiated breasts and 0% (0/176) of non-irradiated breasts (p = 0.0164). Among irradiated breasts, skin necrosis occurred in 11.4% (16/140) compared to 4.5% (8/176) of non-irradiated breasts (p = 0.031). Breast lymphedema developed 207.4 ± 37.6 days postoperatively and 101.6 ± 15.9 days following adjuvant radiation. Mean follow-up was 639 days. Breast lymphedema incidence following partial mastectomy and oncoplastic reduction was 3.6% in this series and occurs 3–4 months after radiation. Radiation was the only significant risk factor for developing breast lymphedema. This largest series on breast lymphedema after oncoplastic reduction corroborates that oncoplastic reduction may be protective. Full article

Nuclear energy is a clean and efficient energy source crucial for the future energy supply. The harsh conditions in reactors, including high temperature, high pressure, and intense neutron irradiation, cause structural materials to accumulate irradiation damage, leading to performance degradation. Austenitic stainless steel, due to its superior mechanical properties, irradiation resistance, and corrosion resistance, has been extensively utilized as a core structural material in light water reactors and emerged as a candidate material for Generation IV nuclear reactors. Therefore, understanding irradiation damage and macroscopic properties evolution in austenitic stainless steels is critical for enhancing the safety and long-term service life of reactor core materials. This review began by elucidating the application of charged particles in irradiation studies, emphasizing the prevailing substitution of neutron irradiation with proton irradiation experiments in current studies. Subsequently, the work systematically synthesized irradiation damages and their consequential impacts on macroscopic properties. Finally, it consolidated the progress and provided prospects for research on improving the resistance of austenitic stainless steel to irradiation-induced segregation, irradiation hardening, irradiation swelling, and irradiation-corrosion synergies. Full article

The development of accident-tolerant fuels has significantly enhanced the safety of fission reactors. The TiNbZrO alloy system has garnered considerable attention due to its excellent mechanical properties and outstanding irradiation resistance. Its unique compositional design enables effective suppression of irradiation-induced defect formation. In this study, TiNbZrO thin films are fabricated via radio-frequency magnetron sputtering and irradiated with 50 keV He ions to fluences of 5 × 10¹⁶, 1 × 10¹⁷, and 2 × 10¹⁷ ions/cm². The microstructural evolution before and after irradiation is characterized by Transmission Electron Microscopy (TEM) and Grazing Incidence X-ray Diffraction (GIXRD), and the changes in mechanical properties are evaluated by nanoindentation. With increasing irradiation fluence, the average size of He bubbles increases from 1.10 nm to 2.06 nm, the number density decreases from 5.27 × 10²⁴ m⁻³ to 1.39 × 10²⁴ m⁻³, and the swelling rate rises from 0.37% to 0.64%. Although significant irradiation hardening is observed in all samples, the maximum hardening rate reaches only 31.91%, a value substantially lower than that reported for many conventional nuclear materials. This demonstrates the superior irradiation resistance of TiNbZrO thin films. The superior irradiation resistance of TiNbZrO thin films stems from two synergistic effects: high-entropy lattice distortion suppresses atomic diffusion, while oxygen complexes pin defects. Full article

Wheat is rich in carbohydrates and proteins but is susceptible to pest infestation and microbial contamination during storage. Owing to itself high efficiency, energy savings, and lack of chemical residues, electron beam irradiation (EBI) has been widely applied for disinfesting and sterilizing cereals and has been shown to influence dough quality. Notably, starch is present within complex wheat flour systems during processing, and its irradiation response may differ from that of purified systems. In this study, the effects of different EBI doses (0, 3, 6, 9 and 12 kGy) on the multiscale structure and physicochemical properties of wheat starch isolated from irradiated dough were systematically investigated, and key analytical techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and rheological analysis were employed to elucidate the mechanisms underlying its impact on the dough thermomechanical behavior of dough. The results demonstrated that EBI weakened gluten–starch interactions and disrupted gluten network the continuity and compactness of the gluten network, resulting in significant dough farinography and pasting property changes. Compared with those of the control group, the dough development and stability time of the 12 kGy sample decreased from 3.920 and 6.465 to 0.970 and 1.290, respectively (p < 0.05). Moreover, irradiation induced cracks on the starch surface, reduced its molecular weight, and disrupted its crystallinity and short-range order. These changes resulted in decreases in the thermal stability level and swelling capacity of starch, while increasing its solubility. A correlation analysis revealed that the starch chain length distribution, molecular weight, molecular order, and pasting properties are key determinants of EBI-induced dough quality changes. This study provides theoretical insights into the applicability of EBI in the context of wheat flour storage and quality modulation. Full article

Additively manufactured (AM) and wrought 316L stainless steels were irradiated with 2 MeV protons at 360 °C. Depth-resolved void swelling was quantified using cross-sectional transmission electron microscopy, with a safe-zone analysis applied to exclude near-surface and proton-range artifacts. The AM 316L exhibits significantly lower swelling than the wrought alloy. Swelling in the AM material is characterized by larger voids but a much lower void number density, whereas the wrought alloy develops smaller voids at a substantially higher density. The two alloys also display distinct dependences on local damage: in AM 316L, void size increases with local dpa while the void density remains nearly constant, whereas in wrought 316L, the void size is approximately constant and the void density increases with local dpa. These trends indicate that AM 316L has already entered a void growth-dominated regime, while wrought 316L remains in a void-nucleation-dominated regime. The reduced swelling in the AM alloy is attributed to more effective defect-recombination sinks and/or reduced vacancy mobility associated with the AM microstructure. These findings provide important insight for the evaluation and optimization of AM 316L alloys for nuclear industry applications. Full article

Developing safe and effective hemostatic materials is critical for rapid bleeding control and wound management. However, traditional hemostatic materials using chemical crosslinking often fall short in hemostatic efficiency and carry risks of secondary injury from reagent residues. This study introduced an irradiation-fabricated composite collagen sponge based on fish skin collagen, chitosan, and soluble starch. The sponge was prepared via material solution blending, followed by cobalt-60 gamma irradiation at various doses, with casting and freeze-drying. Its functionality and safety were systematically evaluated. The results show that low-dose gamma irradiation (1–3 kGy) applied to a precursor solution prior to freeze-drying promoted intermolecular crosslinking, improving mechanical strength, elongation, and biostability, while higher doses (6 kGy) slightly reduced crosslinking due to the partial degradation of collagen, chitosan, and starch. With low-dose irradiation, the proposed hemostatic sponges show enhanced water absorption, blood cell adsorption, swelling, and antibacterial properties, indicating effective hemostatic performance. Spectroscopic characterization confirmed chemical bond modifications with no loss of crystallinity. Cytotoxicity and in vivo tests demonstrated biocompatibility and effective hemostatic performance. Compared with the commercial HSD sponge, the irradiated sponges exhibited superior hemostatic efficacy. This study presents that a collagen-based synergistic matrix prepared by gamma-ray irradiation can produce a hemostatic sponge with enhanced absorbency, bioactivity, and antibacterial properties, highlighting its great potential in rapid hemostasis and wound care applications. Full article

Vividly colored cholesteric liquid crystal polymer network (CLCN) patterns based on epoxy resin are used in decorative and anti-counterfeiting applications. These films are typically prepared via cationic photopolymerization and post-polymerization to achieve a high cross-linking degree. In this work, the cross-linking degree is controlled by varying the UV irradiation dosage during photopolymerization. Following this, the reflection band of the CLCN film changes after removing non-cross-linked compounds with acetone. Leveraging the low cationic polymerization rate and the chain termination capability of methanol, a structurally colored CLCN film with regionally tailored cross-linking was fabricated. With the treatment of acetone, a colorful pattern was observed. Moreover, upon immersion in methanol, the film swelled, revealing a colorful pattern. After the evaporation of methanol, the pattern disappeared. Consequently, this CLCN film holds significant potential for information encryption applications. Full article

Background: Chronic diabetic wounds, particularly diabetic foot ulcers (DFUs), are prone to recurrent infection and delayed healing, resulting in substantial morbidity, mortality, and economic burden. Multifunctional wound dressings that combine antibacterial, antioxidant, conductive, and self-healing properties may help to address the complex microenvironment of chronic diabetic wounds. Methods: In this study, ε-poly-L-lysine and amino-terminated polyethylene glycol were grafted onto carboxylated single-walled carbon nanotubes (SWCNTs) via amide coupling to obtain ε-PL-CNT-PEG. Aminated chondroitin sulfate (CS-ADH) and a catechol–metal coordination complex of protocatechualdehyde and Fe³⁺ (PA@Fe) were then used to construct a dynamic covalently cross-linked hydrogel network through Schiff-base chemistry. The obtained hydrogels (Gel0–3, Gel4) were characterized for photothermal performance, rheological behavior, microstructure, swelling/degradation, adhesiveness, antioxidant capacity, electrical conductivity, cytocompatibility, hemocompatibility, and antibacterial activity in the presence and absence of near-infrared (NIR, 808 nm) irradiation. Results: ε-PL-CNT-PEG showed good aqueous dispersibility, NIR-induced photothermal conversion, and improved cytocompatibility after surface modification. Incorporation of ε-PL-CNT-PEG into the PA@Fe/CS-ADH network yielded conductive hydrogels with porous microstructures and storage modulus (G′) higher than loss modulus (G′′) over the tested frequency range, indicating stable gel-like behavior. The hydrogels exhibited self-healing under alternating strain and macroscopic rejoining after cutting. Swelling and degradation studies demonstrated pH-dependent degradation, with faster degradation in mildly acidic conditions (pH 5.0), mimicking infected chronic diabetic wounds. The hydrogels adhered to diverse substrates and tolerated joint movements. Gel4 showed notable DPPH• and H₂O₂ scavenging (≈65% and ≈60%, respectively, within several hours). The electrical conductivity was 0.19 ± 0.0X mS/cm for Gel0–3 and 0.21 ± 0.0Y mS/cm for Gel4 (mean ± SD, n = 3), falling within the range reported for human skin. In vitro, NIH3T3 cells maintained >90% viability in the presence of hydrogel extracts, and hemolysis ratios remained below 5%. Hydrogels containing ε-PL-CNT-PEG displayed enhanced antibacterial effects against Escherichia coli and Staphylococcus aureus, and NIR irradiation further reduced bacterial survival, with some formulations achieving near-complete inhibition under low-power (0.2–0.3 W/cm²) 808 nm irradiation. Conclusions: A dynamic, conductive hydrogel based on PA@Fe, CS-ADH, and ε-PL-CNT-PEG was successfully developed. The hydrogel combines photothermal antibacterial activity, antioxidant capacity, electrical conductivity, self-healing behavior, adhesiveness, cytocompatibility, and hemocompatibility. These properties suggest potential for application as a wound dressing for chronic diabetic wounds, including diabetic foot ulcers, although further in vivo studies are required to validate therapeutic efficacy. Full article