Search Results (7,282)

Background/Objectives: Cranioplasty (CP) is associated with high complication rates (20–50%), and the optimal choice between patient-specific implants (PSIs) and hand-molded (HM) alternatives remains debated. This systematic review and meta-analysis aims to compare surgical and postoperative outcomes between PSIs and HM implants. Methods: A systematic search was performed in three databases to identify studies reporting surgical site infection (SSI), implant removal, reoperation, operative time or cosmetic outcome for PSIs and/or HM implants. Two-arm studies of the same material were analyzed separately from pooled single- and two-arm studies. Results: 125 observational studies involving 10,034 patients were included. In two-arm comparisons, PSIs reduced implant removal for titanium (OR 0.34, p = 0.053) and PMMA (OR 0.56, p = 0.188), while SSI rates showed no meaningful difference between groups. In one-arm analyses, PSIs demonstrated lower explantation probabilities (titanium 6.1%, PMMA 7.9%) compared with HM alternatives (titanium 9.9%, PMMA 14.2%), alongside shorter operation times and fewer reoperations. Cosmetic outcomes consistently favored PSIs. Conclusions: PSIs demonstrate advantages in efficiency, durability, and esthetics compared with HM implants, supporting their preferential use where resources allow. HM implants remain a cost-effective option in resource-limited settings. Due to the observational nature of the included studies and differences in study populations across arms, the findings should be interpreted with caution. Full article

Background/Objectives: Polymeric microneedles are an innovative drug delivery form combining the benefits of both transdermal and intravenous administration. However, their practical application is limited by fabrication challenges. To address this, the study explores a novel approach for the rapid, precise, and customized production of polymeric microneedles of diverse geometries by utilizing Liquid Crystal Display (LCD) 3D printing technology, marking the first reported use of this technique for microneedle mold fabrication. Methods: LCD 3D printing technology was applied to prepare resin biocompatible microneedle molds. The method developed was optimized by identifying and controlling the critical process parameters (CPPs) through implementing statistical experimental design techniques within the Quality by Design regulatory framework for pharmaceutical development. The optimized molds were subsequently utilized to produce polyvinyl alcohol microneedles with customized shapes and geometries. Representative designs were then loaded with Ropinirole Hydrochloride as a model drug and evaluated in relation to their morphology, drug content, skin insertion depth, and permeability. Results: The application of a Central Composite Design identified layer height and exposure time as the critical process parameters affecting mold fabrication. The optimized design space enabled the selection of printing conditions that maximized dimensional accuracy. Employing these optimum LCD 3D printing parameters, microneedles of various shapes and dimensions were successfully fabricated, exhibiting highly dimensional accuracy. Additionally, tuning skin permeability was proven to be feasible by adjusting microneedle geometry. Conclusions: This work demonstrates the successful use of LCD 3D printing technology in producing biocompatible molds for customized microneedle fabrication, facilitating the development of transdermal delivery systems with personalized drug permeation profiles. Full article

The growing demand for high-quality decorative polymer surfaces has increased interest in Out Mold Decoration (OMD), yet the combined influence of processing conditions and product geometry on film adhesion and deformation remains insufficiently defined. This study establishes an integrated framework that connects OMD process parameters with geometry-dependent deformation behavior using polycarbonate films printed with an ink grid. Adhesion and surface quality were evaluated using 2.5D specimens, while 3D models with varied fillet radii, slopes, and heights enabled quantitative assessment of grid-spacing evolution and thickness distribution. Results show that preheating smooths the film without improving adhesion, whereas increasing the forming environment temperature enhances both bonding and surface quality within the material’s thermal tolerance. Vacuum pressure strengthens film–substrate contact but requires moderation to prevent overstretching. An optimized condition of 100 °C preheating, 90 °C forming temperature, and 2.5 kg vacuum pressure provides a balanced performance. Geometric factors exert strong control over deformation, with small radii, steep slopes, and tall features producing greater strain and nonuniform thinning. These findings establish practical processing windows and geometry guidelines for achieving reliable OMD components that integrate high visual quality with stable adhesion performance. Full article

This study provides a comprehensive assessment of the effect of direct (probe) and indirect (bath) ultrasound treatments on the physicochemical and structural properties of red bell pepper (Capsicum annuum L.) tissue. Ultrasound was applied under controlled conditions to induce structural modification without excessive thermal or mechanical damage. The treated samples were evaluated using chemical (polyphenols, flavonoids, carotenoids, vitamin C, sugars), microbiological (total viable count (TVC) and total yeast and mold count (TYM)), spectroscopic (FTIR, NMR), thermal (TGA), and microscopic (SEM, micro-CT) analyses. Both ultrasound modes affected the tissue, but their effects differed in intensity and character. Direct ultrasound caused stronger cavitation and mechanical stress, resulting in greater cell wall disruption, higher permeability, and enhanced release of bioactive compounds such as polyphenols, vitamin C and antioxidants from the tissue matrix to the surroundings. Indirect ultrasound acted more gently, preserving cellular integrity and sugar profile while moderately increasing antioxidant activity. Cluster and correlation analyses confirmed that ultrasound mode was the main factor differentiating the samples. Short-term direct sonication enhanced the release of antioxidant compounds, whereas prolonged exposure led to their degradation, resulting in an overall decline in antioxidant capacity, and indirect ultrasound better preserved texture and sugar composition. This demonstrates that ultrasound mode and duration can be tailored to balance tissue integrity and enhance bioactive compounds in plant-based materials. Full article

One of the main processes of shoe-sole production is injection molding, in which the desired shape is achieved by injecting a heated thermoplastic polymer in a highly plastic state under high pressure into the mold cavity. The study shows the energy analysis and share of electricity costs in the process of injection into the mold cavity to achieve the desired shape and describe the production process of PVC. Although fairly accurate energy-consumption comparison in the injection-molding process is almost unachievable since it depends on the type of machine, feedstock and molded product, it is still crucial for optimizing energy efficiency. The analysis showed that the basic process requirements of shoe-sole injection molding requires electrical energy in the amount of 5.76 kWh per pair of produced soles, while an increase in energy efficiency and environmental pollution reduction can be achieved by the return of process condensate, with a return share of Y = 80%. The price of electricity per pair of manufactured shoe soles is calculated, and given the fluctuations regarding fossil fuel market, the heat recovery potential leading to fossil-fuel savings in PVC production is analyzed. Full article

Serum tests are valuable sources of information for disease diagnosis. Conventional whole blood cell separation requires many processing steps, including centrifugation, fractionation, lysis, and dilution, and is therefore complex and time consuming. To address the need for the efficient separation of blood cells for on-chip rapid serum assays, we developed a microfluidic chip integrating inertial sorting and deterministic lateral displacement. This chip consists of a helical structure and a deterministic lateral displacement triangular microcolumn array for rapid and efficient separation of blood cells from whole blood samples. After separation, the supernatant is extracted at the exit for subsequent testing or directed to serum test units directly integrated in the chip. Here, the laminar flow and transport modules are coupled using finite element analysis for both multi-component and discrete-phase physical fields to simulate blood flow characteristics in the chip. The influences of flow rate and flux ratio on the sorting efficiency of blood cells were also discussed. Simulation results determined that the microfluidic chip designed in this research can achieve a cell sorting efficiency greater than 98% at suitable flow rates. Experimental results similarly achieved a high sorting effect of above 96%. Therefore, this blood cell sorting microfluidic chip shows strong potential for rapid serum testing applications and can be integrated as a stand-alone blood cell sorting module for various on-chip serum testing systems used to diagnose diseases. Full article

Accurate and real-time state of charge (SOC) monitoring is critical for the safe, efficient, and stable long-term operation of vanadium redox flow batteries (VRFBs). Traditional monitoring methods are susceptible to errors arising from side reactions, cumulative drift, and electrolyte imbalance. This study develops a non-invasive optical sensor module for the negative electrolyte (anolyte), utilizing the favorable spectral properties of V(II)/V(III) ions at 850 nm for real-time SOC tracking. A fifth-order polynomial model was employed for calibration, successfully managing the non-linear optical response of highly concentrated electrolytes and achieving exceptional accuracy (adjusted R² > 0.9999). The optical sensor reliably tracked capacity degradation over 50 galvanostatic cycles, yielding a degradation curve that showed a high correlation with the conventional coulomb counting method, thus confirming its feasibility for assessing battery’s state of health. Contrary to initial expectations, operating at higher current densities resulted in a lower capacity degradation rate (CDR). This phenomenon is primarily attributed to the time-dependent nature of parasitic side reactions. Higher current densities reduce the cycle duration, thereby minimizing the temporal exposure of active species to degradation mechanisms and mitigating cumulative ion imbalance. This mechanism was corroborated by physicochemical analysis via UV-Vis spectroscopy, which revealed a strong correlation between the severity of spectral deviation and the CDR ranking. This non-invasive optical technology offers a low-cost and effective solution for precise VRFB management and preventative maintenance. Full article

Polypropylene (PP) is a highly sought-after synthetic polymer. Due to its properties, it has wide applications in a number of industries. One-dimensional molded materials (fibers and strands) are widely used in the textile and construction sectors. Concrete reinforcing using PP fiber is an intriguing use in construction. Fiber can be provided in two forms: fine fibers (microfiber) and extrudates (macrofiber). The macrofiber has a length of up to 60 mm and a thickness of up to 300 microns. The aim of the work was to obtain PP-based macrofibers from recycled polymer using the natural antioxidant tocopherol. The initial polymer is used to produce the fiber, whereas, in this work, it is proposed to use a secondary PP. Vitamin E, a natural antioxidant, was added to the system to stabilize the melts. It has been demonstrated that adding up to 0.5% Vitamin E reduces the heat degradation of the polymer and yields melts with the appropriate viscoelastic characteristics. Rheological data was used to determine the fiber’s formability window. Macrofibers were derived from melts with varying histories. Their structure was investigated using X-ray structural analysis and IR spectroscopy, and their mechanical characteristics were assessed. Full article

There is a growing interest in the application of natural and waste-derived biofillers for reinforcing thermoplastic polymers, as their utilization helps to reduce the carbon footprint and therefore enhances sustainable development. The aim of this study is to synthesize and characterize a biocomposite based on PP reinforced with OS particles derived from biomass in order to reduce plastic shrinkage after injection molding and to assess their viability as environmentally sustainable materials. The addition of OS particles (10 wt.% and 30 wt.%) significantly reduces the crystallinity of the PP, thereby improving its rigidity, its tensile strength, and its thermal stability. DSC analysis and TGA validated superior thermal properties, whereas mechanical and dynamic mechanical assessments indicated augmented stiffness and energy storage capacity with increasing filler content. The utilization of OS waste, abundant in CaCO₃, facilitates a circular economy model, minimizing environmental impact and enhancing waste valorization. The findings underscore the viability of PP/OS biocomposites as sustainable substitutes for traditional mineral-filled polymers in engineering applications. Full article

Tissue engineering offers a promising solution by developing scaffolds that mimic the extracellular matrix and guide cellular growth and differentiation. Recent evidence suggests that scaffolds must provide not only biocompatibility and appropriate mechanical properties, but also the structural complexity and heterogeneity characteristic of natural tissues. Particle-based scaffolds represent an emerging paradigm in regenerative medicine, wherein micro- and nanoparticles serve as primary building blocks rather than minor additives. This approach offers exceptional control over scaffold properties through precise selection and combination of particles with varying composition, size, rigidity, and surface characteristics. The presented review examines the fundamental principles, fabrication methods, and properties of particle-based scaffolds. It discusses how interparticle connectivity is achieved through techniques such as selective laser sintering, colloidal gel formation, and chemical cross-linking, while scaffold architecture is controlled via molding, templating, cryogelation, electrospinning, and 3D printing. The resulting materials exhibit tunable mechanical properties ranging from soft injectable gels to rigid load-bearing structures, with highly interconnected porosity that is essential for cell infiltration and vascularization. Importantly, particle-based scaffolds enable sophisticated pharmacological functionality through controlled delivery of growth factors, drugs, and bioactive molecules, while their modular nature facilitates the creation of spatial gradients mimicking native tissue complexity. Overall, the versatility of particle-based approaches positions them as prospective tools for tissue engineering applications spanning bone, cartilage, and soft tissue regeneration, offering solutions that integrate structural support with biological instruction and therapeutic delivery on a single platform. Full article

During the manufacturing and development of a proof-of-concept prototype of a continuous fiber polyphenylene sulfide (PPS) composite vehicle component, unexpected results were observed in thick laminates of an E-glass-fiber-reinforced PPS matrix, which utilized carbon black as a colorant (GF/PPS+CB). Extensive interlaminar macrocracking, transverse intralaminar microcracking, and micro-/macrovoids were observed in GF/PPS+CB laminates after compression forming. When processed under identical conditions, no micro-/macrocracking or voids were present in GF/PPS laminates and carbon fiber/PPS laminates without carbon black colorant. These observations prompted further investigation into the influence of processing conditions, presence of colorant, mold design (open and closed molds), and geometry (flat and curved) on the development of matrix defects in thick continuous fiber-reinforced PPS laminates. Full article

This study investigates the melt-flow behavior of the AlSi₉Cu₃ alloy during high-pressure die casting using a combined experimental and numerical approach. A transparent die and a high-speed camera were used to capture the transient motion of the melt front, while a validated computational model reproduced the filling dynamics under identical boundary conditions. The influence of the gating-system geometry—particularly the gate thickness, flow-path length, and inlet cross-section—was analyzed with respect to filling velocity, filling time, and flow stability. To quantify hydraulic losses that arise in practical die-casting conditions, an empirical correction coefficient k₂ was introduced. Its value was obtained by regression analysis based on ten repeated measurements of filling time for each configuration. The deviation between the simulated and experimental velocities did not exceed 5%, demonstrating the reliability of the numerical model within the tested parameter range. The results show that the optimized gating design reduces flow instability, suppresses air entrapment zones, and yields a more uniform velocity distribution across the cavity. The empirical relations derived involving k₂ provide a practical tool for preliminary design of gating systems, enabling faster optimization without extensive trial-and-error procedures. The methodology presented in this work offers a validated basis for improving gating-system performance in high-pressure die casting of aluminum alloys. Full article

The study investigated the adaptation of the snow mold causal fungus, Microdochium nivale, to the fungicides fludioxonil and tebuconazole. Analysis of intrapopulation diversity among 136 M. nivale strains from two Russian populations revealed no strains with high-level resistance to these fungicides. However, the strains exhibited considerable variability in their sensitivity to small fungicide doses. Fungicide sensitivity levels were not associated with virulence levels, whereas strains from different phylogenetic groups exhibited different predispositions to decreased sensitivity to tebuconazole and fludioxonil. In vitro adaptation experiments were conducted to assess: (1) the potential ability of M. nivale to acquire high-level resistance to these fungicides; (2) the relative adaptation efficiency to each fungicide; and (3) the impact of resistance acquisition on virulence. Our results showed that M. nivale strains could adapt to high concentrations of both fungicides with little or no effect on virulence. Adaptation to fludioxonil was significantly less effective than to tebuconazole. To get closer to understanding the mechanisms of fludioxonil adaptation in M. nivale, whole-genome sequencing was performed on a fludioxonil-adapted derivative and its parental fludioxonil-sensitive strain. Comparative genome analysis identified mutations potentially involved in the enhanced fludioxonil resistance, which are discussed within the framework of molecular resistance mechanisms. Full article

Zero-depth nanopores present a promising solution to the challenges associated with ultrathin membranes used in solid-state resistive pulse sensors for DNA sequencing. Most existing fabrication methods are either complex or lack the nanoscale precision required. In this study, we introduce a cost-effective approach that combines PDMS molding at the intersection of silicon micro-blades with an innovative high-resolution nano-positioning technique. These blades are created through photolithography and a two-step KOH wet etching process, allowing for the formation of sub-50 nm 3D rhombic zero-depth nanopores featuring large vertex angles. To address the limitations of SEM imaging—such as dielectric charging and deformation of PDMS membranes under electron beam exposure—we devised a finite element model (FEM) that correlates electrical conductance with pore size and electrolyte concentration. This model aligns closely with experimental data, yielding a mean absolute percentage error of 3.69%, thereby enabling real-time indirect sizing of the nanopores based on the measured conductance. Additionally, we identified a critical channel length beyond which pore resistance becomes negligible, facilitating a linear relationship between conductance and pore diameter. The nanopores produced using this method exhibited a 2.4-fold increase in conductance compared to earlier designs, highlighting their potential for high-precision DNA sequencing applications. Full article

The irrigation sector urgently needs more eco-sustainable materials able to guarantee the same performance as traditional fittings manufactured from virgin fossil-based polymers. In this study, sustainable composites were developed by melt-compounding virgin and recycled polypropylene (RPP) with hazelnut shell (HS) powder with or without maleic-anhydride-grafted polypropylene (PPC) coupling agent. The materials were characterized by a rheological and mechanical point of view. At high shear rates, the viscosity curves of matrices and composites converge, making the difference between neat and filled systems negligible in terms of processability. This indicates that standard injection-molding parameters used for the neat matrices can also be applied to the composites without significant adjustments. Tensile tests showed that adding 10 wt% HS powder increased the elastic modulus by approximately 30% (from 960 MPa to 1.2 GPa) while reducing elongation at break by about 90% compared with neat RPP. The use of PPC mitigated this loss of ductility, partially restoring tensile strength and increasing EB from 6% to 18% in RPP-based composites (+200%). Finally, sleeve bodies and nuts injection-molded from RPP/HS5 and RPP/HS5/PPC successfully resisted internal water pressure up to 3.5 bar without leakage or structural damage. These findings demonstrate that agro-industrial waste can be effectively valorized as a functional filler in recycled polypropylene, enabling the manufacture of irrigation fittings with mechanical and processing performances comparable to those of virgin PP and supporting the transition toward a circular economy. Full article