Search Results (233)

This study aimed to evaluate the influence of various 3D printing resins and post-processing cleaning protocols on the physical and mechanical characteristics of printed dental models. Specifically, the research compared the effects of water-based vs. isopropyl alcohol (IPA)-based cleaning on surface morphology, mass, color stability, and mechanical durability. The findings revealed that surface roughness and microstructure remained constant regardless of the solvent used, indicating that these properties are primarily driven by resin composition and curing protocols. However, specimens cleaned with water exhibited slightly higher mass values due to moisture retention or lower evaporation rates. Color stability remained unaffected by the post-processing method. Most notably, water-cleaned models demonstrated superior mechanical durability and structural integrity compared to those processed with IPA, which is often associated with micro-fractures and excessive dehydration. Full article

Background/Objectives: Primary cytoreductive surgery for advanced ovarian cancer is associated with a high risk of postoperative complications, particularly surgical site infections, which may delay recovery and adjuvant treatment. This study aimed to evaluate the impact of a revised infection-prevention bundle, centered on chlorhexidine-alcohol skin antisepsis, on surgical site infection rates and cost-effectiveness. Methods: In this single-center cohort study, 636 patients undergoing primary cytoreductive surgery between January 2019 and December 2023 were included. A historical control group (n = 300) received povidone-iodine for intraoperative skin preparation, while a prospective intervention group (n = 336) received chlorhexidine gluconate 2% in 70% isopropyl alcohol. Both groups were managed within a standardized perioperative care pathway. Surgical site infections within 30 days were defined according to established criteria. Comparative and descriptive statistical analyses were performed. Results: Baseline clinicopathological characteristics were comparable between groups. The overall surgical site infection rate was significantly lower in the chlorhexidine-alcohol group compared with the povidone-iodine group (8.3% vs. 14.0%; p = 0.0226). The reduction was particularly evident in procedures lasting more than 180 min (9.5% vs. 17.1%; p = 0.0199), while no significant difference was observed in shorter procedures. Cost analysis demonstrated a net saving of approximately EUR 451 per procedure in the chlorhexidine group, driven by reduced infection-related costs and improved operating room efficiency. Conclusions: Baseline clinicopathological characteristics were comparable between groups. The overall surgical site infection rate was significantly lower in the chlorhexidine-alcohol group compared with the povidone-iodine group (8.3% vs. 14.0%; p = 0.0226). The reduction was particularly evident in procedures lasting more than 180 min (9.5% vs. 17.1%; p = 0.0199), while no significant difference was observed in shorter procedures. Cost analysis demonstrated a net savings of approximately EUR 451 per procedure in the chlorhexidine group, driven by reduced infection-related costs and improved operating room efficiency. Full article

Background/Objectives: Provisional restorations are essential in prosthodontic treatment, and reliable intraoral repair is clinically important during extended interim use. This in vitro study evaluated the effects of organic solvent pretreatment on surface characteristics and shear bond strength (SBS) of CAD/CAM provisional restorative materials fabricated by milling, stereolithography (SLA), and digital light processing (DLP). Methods: Three materials were assigned to five surface treatment conditions: no solvent (control), isopropyl alcohol (IPA), tetrahydrofuran (THF), acetonitrile (ACN), and pyridine (PYR). After pretreatment, separate specimens were used for surface analysis and SBS testing. Surface roughness was measured by atomic force microscopy using arithmetic mean height (S_a) and root mean square height (S_q), and surface morphology was examined by scanning electron microscopy (SEM). For SBS testing, specimens were repaired using a universal adhesive and a flowable resin composite, followed by failure mode analysis. Data were analyzed using two-way ANOVA and Tukey’s post hoc test (α = 0.05). Results: Material type, solvent treatment, and their interaction significantly affected SBS, S_a, and S_q. The DLP material showed the highest SBS overall, with no significant differences among treatments. In the SLA material, ACN resulted in the lowest SBS, whereas PYR showed the highest mean value. In the milled material, THF, ACN, and PYR produced significantly higher SBS than the control and IPA groups. Conclusions: Within the limitations of this study, the effect of organic solvent pretreatment on repair performance was substrate-dependent. Full article

In this work, sodium alginate (NaAlg) membranes were enhanced with synthesized zinc oxide (ZnO) nanoplates to enable efficient pervaporation dehydration of isopropyl alcohol (IPA). A comprehensive suite of characterisation techniques—scanning electron (SEM) and atomic force (AFM) microscopy, Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), contact angle and liquid uptake measurements—along with density functional theory (DFT) calculations, was employed to establish robust structure–property relationships and to elucidate filler–polymer interactions. Membranes with different ZnO contents were prepared, and membranes based on the optimal NaAlg-ZnO(5%) composite were cross-linked with CaCl₂ to improve stability in aqueous solutions, and supported membranes were developed for prospective applications by applying this composite onto the prepared porous cellulose acetate (CA) substrate. This developed cross-linked supported NaAlg-ZnO(5%)/CA membrane had a permeation flux increased by 2 times or more compared to a dense NaAlg membrane during dehydration of IPA (12–30 wt.% water) with a permeate water content above 99 wt.%. The integrated experimental–theoretical approach provides mechanistic insight into ZnO–NaAlg interactions and demonstrates the strong potential of these mixed matrix membranes for high-efficiency alcohol dehydration, offering a rational design paradigm for next-generation pervaporation membranes. Full article

Background: Additively manufactured surgical guides require post-processing and subsequent decontamination prior to intraoral use. Steam sterilization and chemical disinfection protocols may influence the dimensional stability of polymer-based guide materials and potentially affect clinical fit and accuracy. Objectives: This in vitro study evaluated the dimensional changes of SLA 3D-printed Surgical Guide Resin V1 (Formlabs) after steam sterilization at 121 °C (AUT121) and 134 °C (AUT134) and after disinfection using 70% isopropyl alcohol (IPA70), compared with an untreated control group. Methods: Forty standardized specimens were fabricated using SLA technology and divided into four groups (n = 10/group): Control (CT), 121 °C steam sterilization (AUT121), 134 °C steam sterilization (AUT134), and IPA70 disinfection. Two linear measurement zones (L1 and L2) were assessed per specimen. Baseline measurements were recorded with a caliper (mm). Post-treatment measurements were obtained using microscopic evaluation, recorded in µm, and converted to mm for analysis. Dimensional change was calculated as ΔL = L_after − L_before. Within-group comparisons and between-group analyses were performed with a significance level of α = 0.05. Results: Steam sterilization at 134 °C (AUT 134) produced statistically significant dimensional changes in both zones (L1: p = 0.036; L2: p = 0.042). No statistically significant differences were observed in the AUT121 group (L1: p = 0.437; L2: p = 0.682) or the IPA70 group (L1: p = 0.164; L2: p = 0.086). Between-group analysis showed no significant differences for ΔL1 (p = 0.345), whereas ΔL2 differed significantly among groups (p = 0.021). Conclusions: Under the conditions of this study, AUT134 steam sterilization significantly affected the dimensional stability of SLA-printed Surgical Guide Resin V1 specimens. The AUT121 protocol and IPA70 disinfection did not result in statistically significant dimensional changes compared with baseline. Full article

To evaluate the potential ototoxic effects of lactoferrin on the inner ear using electrophysiological and histological methods. Methods: Thirty-two Sprague-Dawley rats (64 ears) were divided into four groups: control, saline, antiseptic solution (70% isopropyl alcohol + 2% chlorhexidine), and lactoferrin. Groups II–IV received three intratympanic injections. Auditory brainstem response (ABR) tests were performed at baseline, day 7, and day 21. Cochlear histology and VEGF immunoreactivity were assessed. Results: Baseline hearing was similar across groups. Post-treatment, Groups II and IV showed partial recovery at 8, 16, and 24 kHz, while Groups III and IV had worsening thresholds at higher frequencies. Histologically, Group IV’s cochlear structures remained largely intact. VEGF immunoreactivity was severe to moderate in Groups I, II, and IV, and weaker in Group III. Conclusions: Lactoferrin showed relative safety at lower frequencies but possible ototoxicity at higher frequencies. However, no significant structural damage was observed in cochlear tissues. Full article

The current work examines the impact of isopropanol (IPA) on the electrochemical characteristics of nickel foam and Pd-modified Ni foam electrodes in a 0.1 M NaOH medium, with respect to the kinetics of the hydrogen evolution reaction (HER) over the temperature range of 20–40 °C. Comparative HER/IPA examinations are presented for a highly catalytic polycrystalline Pt electrode. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and cathodic Tafel polarization experiments were carried out in this work, where the IPA concentrations ranged from 1.0 × 10⁻⁵ to 1.0 × 10⁻³ M. The introduction of small amounts of isopropyl alcohol into the working electrolyte noticeably facilitated the catalytic efficiency of the hydrogen evolution reaction on the surface of Ni foam electrodes. This is most likely related to the fact that IPA molecules undergo partial electrooxidation to acetone (qualitatively confirmed by GC-MS analysis) during initial CV cycling, which is believed to significantly diminish the surface tension phenomenon during the HER, thus promoting hydrogen bubble separation from the electrode surface. It should also be noted that acetone will continuously be produced at the Pt anode, making it essential to consider further migration of (CH₃)₂CO molecules to the working cell compartment. Most importantly, isopropanol was found not to undergo significant surface electrosorption on the nickel foam-based catalysts, which could otherwise significantly inhibit the hydrogen evolution reaction On the contrary, the presence of IPA in the electrolyte solution seems to have a detrimental effect on the kinetics of both the HER and the UPDH (underpotential deposition of H) processes on the surface of the polycrystalline Pt electrode, which is a superior electrochemical catalyst for HER, but highly susceptible to surface contamination. Full article

Porous nickel oxide nanoparticles with a hierarchical structure and high specific surface area were obtained by green synthesis followed by thermal annealing. The influence of the choice of precursor plant extract (Fumaria officinalis L. and Origanum vulgare L.) and the extractants in aqueous solutions on the parameters of the synthesized particles was studied. Characterization of the NiO morphology and composition, as well as the specific surface area, was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and the BET method of nitrogen thermal desorption. Resulting particles have a spherical shape and a size from 30 to 50 nm. According to the data obtained, it can be seen that when the precursor is changed from Fumaria officinalis L. to Origanum vulgare L., the size of the synthesized particles increases, while the structure becomes more friable. It has been revealed that certain parameters and the nature of the assembly of porous particles lead to an increase in the surface area: the highest value of the SSA of 130.0 m²/g is observed in NiO nanoparticles obtained using Fumaria officinalis L. extract based on isopropyl alcohol. Also, a relatively high SSA value of 73.5 m²/g is observed in nanoparticles obtained using the same extractant for Origanum vulgare L. extract, while the use of an ethyl alcohol-based extractant for Fumaria officinalis L. resulted in the lowest value of 40.2 m²/g. The developed semiconductor particles are promising for use in catalysis, sensors, and as part of supercapacitor electrodes and functional layers in device structures for solar cells. Full article

Thorium carbide (${\mathrm{ThC}}_{2\pm x}$) nano-structured thin disc-like pellets were produced from thoria nanoparticles (${\mathrm{ThO}}_2$-NP) and multi-walled carbon nanotubes (MWCNT). These composites are to be studied as a target material candidate for radioactive ion beam (RIB) production via nuclear reactions upon impact with high-energy proton beams on a stack of solid pellets. The ${\mathrm{ThO}}_2$-NP precursor was produced via precipitation of thorium oxalate from a thorium nitrate solution with oxalic acid and subsequent hydrothermal oxidation of the oxalate, creating the thoria nanoparticles. The ${\mathrm{ThO}}_2$-NP were then mixed with MWCNT in isopropyl alcohol and sonicated by two different methods to create a nanoparticle dispersion. This dispersion was then heated under medium vacuum to evaporate the solvent; the resulting powder was pressed into pellets and taken to an inert-atmosphere oven, where it was heated to 1650 °C and carbothermally reduced to ${\mathrm{ThC}}_{2\pm x}$. The resulting pellets were characterized via XRD, SEM-EDS, and Raman spectroscopy. The resulting thorium pellets exhibited, at most, trace levels of the oxide precursor. Furthermore, the nanotube structures were still present in the final product and are expected to contribute positively towards faster radioisotope release times by lowering isotope diffusion times, which is required for the efficient extraction of the shortest-lived (<1 s half-life) radioisotopes. Full article

An alternative conductive ink based on carbon nanotubes (CNTs) was developed using a platinum-catalyzed silicone elastomer and isopropyl alcohol (IPA). The inclusion of IPA in the conductive CNT ink facilitated the optimization of its mechanical strength, electrical conductivity, and viscosity. Compared to conventional silicone rubber-based conductive polymers that often solidify in a few hours at room temperature or with heating, this liquid composite of CNT particles and IPA exhibited a prolonged duration of up to several months in a hermetic environment, maintaining chemical stability even with the elastomer and its curing agent. The gradual evaporation of IPA initiates a well-known cross-linking process, leading to stretchability and electrical conductivity derived from the silicone elastomer and CNT particles, respectively. The relationship between the mechanical strength and electrical conductivity of the hardened conductive CNT ink was studied, which helped determine the optimized concentration of CNT particles in the conductive CNT ink. Subsequently, a piezoresistive sensor was designed, fabricated, and evaluated. The conductive CNT ink-based piezoresistive sensor showed high sensitivity and good repeatability with respect to a wide range of external forces. The effect of the concentration of CNT particles on the viscosity of the conductive CNT ink was also investigated, providing a better understanding of the entanglement of CNT particles within the silicone elastomer. A coating test using the conductive CNT ink with a paper cutting machine demonstrated its potential for adaptation to various printing techniques, including screen printing. The proposed conductive CNT ink, characterized by a simple chemical composition, facile fabrication process, use of non-toxic elements, high electrical conductivity, and stretchability, combined with an extended duration, has the potential to be applied for multiple purposes, such as various types of flexible and wearable electronics. Full article

This study presents the synthesis and characterization of novel kaolinite niobium and kaolinite titanium niobium nanocomposites and their application as heterogeneous photocatalysts. Utilizing a hydrolytic sol–gel route, we combined kaolinite with isopropyl alcohol, acetic acid, titanium (IV) isopropoxide, and ammonium niobium oxalate, followed by heat treatment at 400, 700, and 1000 °C. X-ray diffraction confirmed the retention of kaolinite’s characteristic reflections, with basal spacings indicating the presence of semiconductors on the external surfaces and edges. Heating treatment not allowing the crystallization of anatase until 1000 °C reveals that Nb⁵⁺ could inhibit the transition to titanium crystalline phases (anatase and rutile). The bandgap energies decreased with clay mineral support, averaging 2.50 eV, and absorbing up to 650 nm. The model reaction of terephthalic acid hydroxylation accomplished by photoluminescence spectroscopy demonstrated that KaolTiNb400 presented a higher rate of *OH production, achieving 591 mmol L⁻¹ min⁻¹ compared to pure KaolNb400 173 mmol L⁻¹ min⁻¹. Photodegradation studies revealed significant photocatalytic activity, with the KaolTiNb400 nanocomposite achieving the highest efficiency, demonstrating 90% removal of methylene blue (combining adsorption and degradation) after 24 h of UV light irradiation. These materials also exhibited promising results for the degradation of the antibiotics Triaxon^® (40%) and Loratadine (8%), highlighting their potential for organic pollutants’ removal. In both cases the presence of byproducts is detected. Full article

An effective surveillance method for invasive insect pests is critical for timely detection and management. This study explores the effectiveness of eight active sampling methods for detecting the presence of the two-spot cotton leafhopper (Amrasca biguttula (Ishida) (Hemiptera: Cicadellidae)), a newly emerging adventive pest in the U.S.A. that is causing economic losses in cotton and okra. We conducted field studies to compare aspirating, bagging, beat sheet, sweep netting, and four tray-based methods: a dry tray, or a tray with 70% isopropyl alcohol, tap water, or soapy water. While aspirating and bagging served as adequate sampling methods, we found that sampling with a tray containing 70% isopropyl alcohol proved to be the most effective and time-efficient approach. This method consistently enabled rapid detection of adult male specimens across both low- and high-population field sites, facilitating reliable morphological identification. Full article

The effectiveness of transdermal drug delivery is restricted by the barrier properties of the stratum corneum. Ethosomes, as vesicular carriers, offer a promising approach to enhance dermal bioavailability. This study aimed to optimize ethosome composition and preparation parameters to improve physicochemical stability and performance. The influence of alcohols (ethyl, n-butyl, n-propyl, isopropyl, tert-butyl), glycols (propylene glycol, ethylene glycol, 1,3-butanediol), and surfactants (Tween 80, Mirasoft^® SL L60) was systematically investigated. Stability was evaluated through zeta potential (ZP), polydispersity index (PDI), and hydrodynamic diameter (D_h). The effects of phospholipid concentration and homogenization were also assessed. SEM imaging confirmed the spherical morphology of vesicles. The optimal formulation comprised 30% (w/w) ethanol, 2.5% (w/w) phospholipid, 10% (w/w) ethylene glycol, and 1.25% (w/w) Tween 80. A comparable mixed-surfactant system (0.625% w/w; 60% Tween 80 and 40% Mirasoft^® SL L60) exhibited similar stability, indicating that glycolipid-based biosurfactants can reduce conventional surfactant requirements. Homogenization significantly enhanced colloidal stability, lowering PDI from 0.366 to 0.083 and D_h from 254 nm to 156 nm, evidencing decreased aggregation and improved size uniformity. Overall, formulation composition and processing conditions critically determine ethosome stability and transdermal delivery efficiency. Full article

This study focuses on the pre-treatment cleaning technology for the polyimide (PI) substrate of flexible nine-in-one microsensors. The environmentally friendly cleaning agent B, developed by Sea Energe, was innovatively used to replace traditional organic solutions (acetone, methanol, and isopropyl alcohol) to verify its feasibility and application potential in Micro-Electro-Mechanical Systems (MEMS) processes. Cleaning agent B, developed by Sea Energe, was used for the first time to clean the PI substrate of flexible nine-in-one microsensors, and the flexible nine-in-one microsensor was used as a verification platform to compare the cleaning performance with traditional organic solutions (acetone, methanol, and isopropyl alcohol). The experimental results proved that cleaning agent B developed by Sea Energe effectively removed contamination from the PI substrate surface while avoiding the environmental impact and process compatibility issues associated with traditional organic solvents. To verify its reliability, the developed flexible nine-in-one microsensor was embedded in the hydrogen end flow channel of a hydrogen/vanadium redox flow battery (HVRFB) to perform real-time monitoring of multiple parameters, including hydrogen concentration, voltage, current, conductivity, temperature, humidity, flow, pressure, and pH. The experimental results proved that using cleaning agent B, developed by Sea Energe, to clean the PI substrate and the subsequent flexible nine-in-one microsensor resulted in comparable operational stability and measurement accuracy to traditional organic solution (acetone, methanol, and isopropyl alcohol) cleaning processes. This experimental result verifies that cleaning agent B, developed by Sea Energe, not only has an excellent cleaning effect, but also meets the requirements for highly reliable microsensor development, potentially offering an alternative solution for the future introduction of green processes into semiconductors, MEMSs, and various application fields. Full article

This study evaluated post-processing protocols for 3D-printed implant surgical guides, aiming to determine the ideal timing after printing and post-curing durations that do not compromise residual monomer release and leachable components or mechanical properties. Specimens made of a surgical guide resin were 3D-printed (Formlabs Form 2) into bars (14 × 1 × 1 mm; n = 10) and square-shaped samples (10 × 10 × 1 mm; n = 1). They were grouped based on the time elapsed after printing (immediate, 24 h, and 72 h) and underwent washing in 99% isopropyl alcohol. Post-curing was performed for 5, 10, 20, or 30 min using a UV-light curing unit (NextDent LC-3DPrint Box). Residual monomer and components levels were assessed through solvent dissolution tests (n = 5), while mechanical properties were evaluated via flexural strength (n = 10) and hardness (n = 10). Statistical analysis with one-way ANOVA and Tukey’s post hoc test showed no significant differences in flexural strength across curing times or storage periods (p > 0.05), with values ranging from 42.93 MPa to 59.43 MPa. Monomers and leachable components were significantly higher immediately after printing (0.84 ± 0.36 mm³) compared to other groups (p < 0.05). For Vickers hardness, a 10 min curing protocol produced values comparable to longer durations (20.26 HV at 20 min/24 h), while the lowest hardness was 14.59 HV in the 5 min groups (p < 0.001). These findings suggest that delaying post-processing up to 72 h and reducing curing time to 10 min do not compromise mechanical properties, released monomers, and leachable components. Full article