Search Results (10,927)

Under continuous erosion of dynamic water pressure generated by vehicle–water–pavement coupling interaction, asphalt mixture will gradually deteriorate and severe moisture damage finally emerges. The fine aggregate mixture (FAM) component is notably eroded and stripped, while the aggregate component even cracks sometimes. Sufficient attention has not been paid to these critical phenomena. This study employed the 3D laser scanning technique to detect changes in surface roughness of the asphalt mixture before and after it was eroded by dynamic water pressure. The degree of erosion of the asphalt mixture, FAM component, and aggregate component were thereby evaluated. The influences of experimental parameters such as water temperature and pore water pressure magnitude, as well as variable parameters including lithology and asphalt type, were also taken into account. By integrating the detection of physical and mechanical properties evolution of aggregates, the mechanism of moisture damage was comprehensively illustrated from the perspectives of both components of FAM and aggregate. The findings revealed that the 3D laser scanning technique could clearly detect and quantitatively assess the morphological changes on the asphalt mixture surface after been eroded in dynamic water pressure. Both types of asphalt mixtures exhibited varying degrees of erosion and wear, and obvious increases in surface unevenness were observed in each case. Variations in either temperature or pore water pressure magnitude showed limited influence on moisture damage in basalt-based asphalt mixture. In contrast, moisture damage sustained by limestone-based asphalt mixture was notably sensitive to temperature changes but remained largely insensitive to fluctuations in pore water pressure magnitude. The increase in surface roughness of asphalt mixture was primarily attributed to the scouring action of dynamic water pressure, which removed the FAM component surrounding coarse aggregate particles. Degradation in coarse aggregate particles would lead to the deterioration of the entire asphalt mixture. The compatibility between the stripping rate of FAM component and the deterioration rate of coarse aggregate governed the macroscopic manifestation of overall moisture damage in the asphalt mixture. Full article

In this experiment, we used a late 17th century embalming protocol for the long-term preservation (7.2 years) of an infant-sized piglet in order to evaluate the success of this technique over a period of several years. According to the description of the French anatomist Penicher (published in 1699), an 8.8 kg female piglet corpse was treated with a broad spectrum of herbs, seeds, leaves, flowers and dried berries, along with an alcohol-based fluid following subtotal exenteration and a reduction in peripheral muscle mass. The further process of this dry embalming technique was monitored by visual, tactile and olfactory evaluation of the embalmed body, along with a record of the body weight. Repeatedly taking samples from the skin and soft tissues provided insight into eventual changes on a histomorphological level and two whole-body CT scans complemented the evaluation of the internal changes within the corpse, which was eventually examined at autopsy. On the macroscopic level, we recorded slight signs of autolysis and very mild putrefaction within the first few weeks and a very well preserved and stable body over the subsequent years of evaluation. In parallel, we noted a gradual loss of fluid, as shown by a reduction in the body weight. This occurred faster in the first year (reduction in body weight by ca. 25%) than in the following ca. 4 years (with another ca. 25% loss of body weight). The CT scans showed stable osseous and soft tissue structures, while the few remaining internal organs that had been left inside the body after initial evisceration (such as kidneys and internal genitalia) had already completely disappeared after approx. 1 year. On the histological level, the histoanatomy of skin, subcutis and muscle remained intact over the entire observation period. A loss of epidermal cell nuclei was not noted before day 1772 and there were only slight signs of adipocire formation of fat tissue at the end point of observation (day 2634). In summary, we can confirm that excellent body preservation of external skin and soft tissue was maintained over a considerably long period (in this case, 7.2 years) using the applied protocol of dry embalming, but a complete loss of residual internal organs/structures beyond skin, subcutaneous fat tissue and muscle. Previous observations of the excellent preservation of an infant mummy that underwent the dry embalming procedure are very plausible. Full article

The integration of vertical greenery systems (VGSs) into existing reinforced concrete (RC) buildings raises questions regarding interface kinematics and the permanent displacement of soil-retaining elements under seismic excitation. This study experimentally investigates the residual displacement of façade-mounted living walls and rooftop planter pods anchored to a deficient RC frame under shake table excitation. A 1:3 scale reinforced concrete frame was tested in two distinct phases: initially as a deficient, unretrofitted structure (Phase A), and subsequently as a retrofitted system integrated with vertical greenery elements (Phase B). High-precision terrestrial laser scanning (TLS) was employed before and after successive seismic excitation stages to generate dense three-dimensional point clouds. Cloud-to-cloud comparison techniques were used to quantify global structural displacement and local kinematic behavior of greenery components, while results were validated against conventional displacement sensors. The RC frame exhibited millimeter-scale permanent displacements consistent with draw-wire measurements. In contrast, planter pods demonstrated configuration-dependent behavior, including up to 8 cm translational sliding and rotational responses reaching 13° under repeated excitation, whereas living wall panels remained stable. Notably, a 95% reduction in point cloud density reproduced global deformation patterns with an RMSE of 3.03 mm and quantified peak displacements with only ~2% deviation from full-resolution results. The findings demonstrate the capability of TLS-based monitoring to detect differential kinematic behavior of integrated VGSs, while highlighting the variability in performance of friction-based rooftop anchorage utilizing different robust planter pod fixing systems. Full article

Bioplastics are in focus for the development of sustainable materials due to the depletion of fossil resources, generation of solid waste and global climate change. Considering this, the current research is devoted to the valorization of beachcast red seaweed F. lumbricalis for the development of thermoplastically processable bioplastics. The composites have been developed from beachcast red seaweed-derived furcellaran (FUR) and potato-derived thermoplastic starch (TPS) by using an ultrasound-assisted technique. Three different FUR concentrations (10, 30 and 50 wt.%) in relation to potato starch were examined for their thermoplastic processability. Fourier infrared spectroscopy (FTIR) was used to reveal the structural changes in the developed TPS/FUR composites depending on FUR content as well as thermal pre-treatment. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and tensile mechanical tests were performed to assess the performance of the developed TPS/FUR composites. It was demonstrated that the ultrasound-assisted manufacturing route allowed TPS/FUR composites with an improved spectrum of properties to be obtained. The highest mechanical stress at break (almost three times higher than for neat TPS) was observed for the TPS + 50 wt.% FUR composite, which also possessed decreased deformability (only ca 10%), reduced thermal resistance at processing temperatures (150 °C) and high shear sensitivity. Thus, the TPS + 30 wt.% FUR and especially the TPS + 10 wt.% FUR composites were recognized as more suitable for thermoplastic processing and the development of TPS-based composites with improved exploitation properties. Full article

Biofilm formation on denture base materials may contribute to oral diseases such as denture stomatitis and therefore represents an important factor in prosthodontic treatment. This in vitro study investigated biofilm formation on dental prosthetic materials manufactured by additive, subtractive, and conventional techniques. Disc-shaped specimens were fabricated from 3D-printed Denture Base Resin (Formlabs), milled Lucitone Digital Fit (Dentsply Sirona), and conventionally processed cold-polymerized PALAPress (Kulzer). Biofilm formation by Streptococcus mutans and Streptococcus sanguinis was assessed separately over a 21-day incubation period using crystal violet staining and photometric determination of optical density at eight predefined time points. Surface characteristics before and after microbial colonization were qualitatively evaluated by scanning electron microscopy. For S. mutans, significant material-dependent differences were observed only at selected time points, while overall biofilm accumulation remained low. In contrast, S. sanguinis exhibited pronounced and repeated differences, with milled PMMA generally showing lower biofilm accumulation compared with additively manufactured and conventionally processed materials. Overall, S. sanguinis formed significantly more biofilm than S. mutans across all materials and time points. These findings indicate that both manufacturing technique and bacterial species influence biofilm formation on denture base materials. Full article

To reduce staining, paper conservators have increasingly treated artworks on paper with enhanced washing using chelating agents, which form complexes with metallic ions, thus facilitating the removal of stains. However, questions remain regarding the efficacy of the method and its impact on the long-term preservation of paper. A treatment of enhanced washing was undertaken on a nineteenth-century mezzotint printed using the chine collé technique, by David Lucas after a painting by John Constable, which was disfigured by significant foxing stains. This intervention provided the opportunity to investigate the mechanism and efficacy of the treatment and whether an alkali reserve could successfully be reintroduced. The print was analysed before, during, and after treatment with a Bruker M6 Jetstream scanning X-ray fluorescence (XRF) spectrometer. The results provided spatially resolved information on the effects of the treatment and gave new insights into the heavily debated causes of foxing on paper, challenging the link with iron contamination. Instead, the distribution of foxing stains showed a correlation with the presence of potassium and calcium, and their reduction during washing corresponded with an improvement in appearance. Calcium replenishment proved only partially successful. Finally, scanning XRF has rarely been used for the analysis of artworks on paper; this study proves its value for research. Full article

Aluminum–silicon (Al-Si) alloys are widely used in aerospace, automotive manufacturing, power electronics, marine engineering and other fields due to their excellent physical properties. However, their corrosion resistance is insufficient in harsh service environments. In this study, a variety of characterization methods were adopted, including scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical measurements (electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization), immersion corrosion tests, and scanning vibrating electrode technique (SVET). The results show that the appropriate heat treatment regime can significantly enhance the corrosion resistance of the alloy, while improper aging parameters will aggravate the corrosion tendency. The optimal heat treatment regime is solution treatment at 500 °C for 4 h followed by aging at 200 °C for 48 h. Under this condition, the corrosion current density (i_corr) is as low as 79.30 μA/cm², and the low-frequency impedance modulus and phase angle in EIS tests are optimal. The as-extruded alloy exhibits severe localized corrosion, while the heat-treated alloy transforms into mild and uniform corrosion. The underlying mechanism is that heat treatment induces the formation of uniformly distributed nanoscale Mg₂Si and Al₃(Sc,Zr) precipitates, which synergistically improve the corrosion resistance of the alloy by weakening micro-galvanic coupling and facilitating the formation of a stable passive film. Full article

Background/Objectives: The biologically oriented preparation technique (BOPT) is a vertical tooth preparation approach that eliminates a conventional finish line and positions the prosthetic margin within the gingival sulcus, aiming to promote peri-restorative soft tissue adaptation through controlled gingival remodeling. This article describes a clinical case report of a hybrid impression protocol combined with a digital workflow intended to address some of the main clinical limitations of BOPT, particularly the recording of deep subgingival margins and the transfer of the emergence profile from the provisional to the definitive restoration. Methods: The proposed technique combined a conventional silicone impression to obtain a complete reading of the gingival sulcus with intraoral digital scanning, complemented by extraoral scanning of the provisional restoration to reproduce its subgingival morphology within the definitive prosthetic workflow. Results: Within the limitations of a single clinical case with short-term follow-up, this hybrid approach showed a satisfactory esthetic outcome and favorable short-term peri-coronal soft tissue behavior. Conclusions: This hybrid workflow may represent a feasible clinical option for transferring the cervical contour and emergence profile to the definitive prosthesis in anterior BOPT restorations. Full article

This study introduces an automated computational tool to evaluate the phase velocity of the highly dispersive A₀ mode using only two signals measured along the wave propagation path. The algorithm combines the zero-crossing technique with automated spectral decomposition, utilizing a bank of bandpass filters with adaptive bandwidths. Validated through theoretical and experimental analysis of an aluminium plate near 300 kHz, the results demonstrate that using a two-signal set and variable filter widths significantly improves accuracy and extends the measurable frequency range of the dispersion curve. Experimental results demonstrate that by applying various filter widths, the phase velocity dispersion curve segment can be reconstructed over a frequency range exceeding 65% of the signal’s spectral width at the −40 dB level. The reconstruction yielded an average relative error of 0.8% ± 1.2%, while the best-case scenario showed an error of just 0.3% ± 0.4%. Implementing automated filter parameter selection on a signal pair offers a time-efficient alternative to traditional spatial scanning, significantly simplifying data collection while reducing labour and time requirements. Full article

Background and Clinical Significance: Modern neuro-oncologists encounter a major challenge when dealing with glioblastomas located in the dominant hemisphere’s temporo-basal area, because their invasive nature disrupts the proximity to eloquent cortical areas (language and speech), as well as skull base venous structures, which can lead to a quick decline in function from the disruptions in these networks and the disconnection of corridor-level pathways. This manuscript illustrates the application of metric-based phenotyping, anatomically defined imaging, and venous-anchored microsurgical techniques that can aid in preserving the remaining functional reserve in patients with dominant hemisphere glioblastomas and demonstrate measurable outcomes through longitudinal follow-up data. Case Presentation: A 48-year-old right-handed male patient presented with a four-week history of progressively worsening symptoms consistent with a dominant hemisphere syndrome, resulting in a significant decrease in his independence (mRS 0 → 4; BI 55/100; IADL 2/8). His symptoms included non-fluent expressive aphasia with a marked inability to generate words and respond to verbal cues (BNT 8/30; SF 4 WPM). Additionally, he experienced prolonged lateralizing hemisensory decompensation and corticospinal tract dysfunction. Imaging studies revealed a large multiloculated cystic lesion located in the left temporo-basal region. The lesion displayed a thick irregular peripheral enhancement pattern with mural nodules and septa, and surrounding T2 hyperintensity extending into the temporal associative white matter, indicating disruption of the lexical–semantic networks and corridor-level tracts. Utilizing continuous SSEPS/MEPs during surgery, a skull base parallel ventral temporal corridor was developed to allow decompression of the cyst first, followed by cyst evacuation, inside-out cytoreduction, subpial dissection, and specific preservation of both superficial and deep temporal veins using selective capsular preservation at venous interface locations where necessary. Postoperative CT scans performed on POD #3 and POD #7 indicated stable decompression without hemorrhage or hydrocephalus complications, followed by rapid quantitative improvement in NIHSS (8 → 2), MoCA (18 → 26), BNT (8 → 26), SF (4 → 12), mRS (2 at discharge, 1 at follow-up), BI (85 at discharge, 95 at follow-up), and IADL (6/8 at discharge, 8/8 at follow-up). Histopathological examination confirmed a diagnosis of glioblastoma. Conclusions: This case study supports a model of a network- and vein-constrained glioblastoma of the dominant hemisphere in the temporo-basal region that can result in substantial restoration of language capabilities and preservation of functional reserves for additional therapies using venous-anchored subpial microsurgical approaches. The use of objective and quantifiable measures of phenotyping and longitudinal follow-up tracking could provide a reproducible method for measuring the degree of recovery of the affected network(s) and establishing safe boundaries for temporal glioma surgery. Full article

This study presents a comprehensive characterization of Argopecten purpuratus (AP) shells—a marine-derived natural bioceramic composed predominantly of calcium carbonate (CaCO₃)—to evaluate their potential as biomaterials for regenerative medicine. Structural and compositional analyses were performed using micro-computed tomography (MicroCT), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). These techniques confirmed a high CaCO₃ content (>96 wt%) and revealed distinct microstructural features: the outer surface showed irregular grooves and rough textures, while the inner surface exhibited smoother, foliated morphologies with mixed calcite and aragonite phases. To assess biocompatibility, human gingival mesenchymal stem cells (hGMSCs) were cultured on both shell surfaces. Viability and adhesion were evaluated via MTS assays and fluorescence microscopy at time points ranging from 30 min to four weeks. Both surfaces supported robust early metabolic activity and long-term proliferation, with cells covering the entire surface area after four weeks. Morphometric analysis indicated time-dependent changes in cell shape, transitioning from rounded to elongated morphologies, with minor differences linked to surface topography. The integration of structural, compositional, and biological data demonstrates that AP shells provide a cytocompatible and sustainable natural material platform capable of supporting cell adhesion and proliferation. Their inherent micro- and nanoscale surface features may facilitate protein adsorption and cell–material interactions. These findings highlight the importance of correlating microstructural material properties with cellular responses and support the future exploration of marine-derived bioceramics for regenerative medicine applications. Full article

Janus nanoparticles (JNPs) synthesis has caught the scientific community’s attention due to their amphiphilic properties and extensive areas of application. In this work, different new copper–silica-based and silica-based JNPs were synthesized using a novel masking methodology and a self-assembly method based on sol–gel procedures, respectively. Moreover, various techniques were used to characterize the developed nanomaterials, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Two types of copper–silica-based Janus nanoparticles were synthesized with a 40 to 70 nm size, while SiO₂-based JNPs of around 135 nm were obtained. The duality of different JNPs was confirmed by SEM and by a simple and economical route based on an emulsion stabilization path: analyzing dispersion/aggregation and associated behavior at the immiscible solvent interface. JNPs exhibited an extended residence time over 20 days at an immiscible solvent interface, thereby enhancing the resulting emulsion interface stability. This behavior highlighted their amphiphilic characteristics in comparison to conventional nanoparticles. Consequently, a procedure to determine nanoparticle amphiphilicity could be further standardized. Full article

Background: In children with cerebral palsy, bony acetabular deficiencies are common and may be associated with progressive hip subluxation, abnormal joint loading, and ultimately hip dislocation. Hip reconstruction surgery is typically performed to prevent dislocation, and this includes acetabular reshaping using acetabuloplasty. The location of acetabular deficiency may vary among individuals; however, only radiographs are used for planning and intraoperative correction in many centers. Precise reconstruction and preop planning are necessary for the accurate correction of acetabular coverage. This study compares conventional hip reconstruction with a 3D-guided technique using individual preop 3D planning and 3D-printed guides during surgery to determine which method allows for a more accurate correction. We hypothesize that the patient-specific 3D planning leads to more precise anatomical correction of acetabular coverage compared to conventional freehand osteotomy. Methods: This study was registered in the German Clinical Trial Register (DRKS-ID: DRKS00031356) on 14 July 2023. In a randomized controlled trial, various imaging-based parameters were used to assess the bony anatomy preoperatively and postoperatively. Preoperative and 6-week postoperative computed tomography (CT) scans are part of routine clinical care. Additionally, an immediate postoperative CT scan was performed. One hip was operated on using individualized 3D preoperative planning, while the other hip was corrected using a conventional surgical approach. A standardized subtrochanteric osteotomy was performed for the varisation, derotation, and shortening of the proximal femur. This osteotomy was followed by acetabuloplasty under fluoroscopic control. For the 3D-planned operation, patient-specific cutting and repositioning guides were produced based on preoperative CT imaging. Patients with bilateral cerebral palsy (GMFCS levels I–V), aged 4–18 years, with an open triradiate growth plate and a migration index ≥ 40% in at least one hip were included. In a preliminary retrospective part, this project reproduces the existing three-dimensional acetabular index (3-DAI) and compares it with established radiographic methods to determine the utility and reliability of a reconstructed 3D CT measurement technique. A further component of the retrospective part is the creation of an age-adjusted database of typically developed hips and the development of a 3D head coverage index (3D-HCI) as a new 3D parameter to express acetabular coverage; therefore, it will be used as a secondary parameter and correlated to the 3DAI in the prospective part. Conclusions: Improved precision may have meaningful clinical implications for long-term joint congruency, load distribution, pain, and mobility outcomes. Full article

Background and Objectives: The authors aimed to describe their experience performing frameless stereotactic biopsies using an Autoguide Robotic Platform and to compare the outcomes with a frame-based stereotactic technique. We would like to emphasize the importance of this study, as it is the first in the literature to use sodium fluorescein for confirmation in intracranial biopsies taken with a Stealth Autoguide Robotic Platform. Materials and Methods: We retrospectively evaluated 30 patients who underwent a stereotactic intracranial biopsy between June 2018 and March 2024. The patients were divided into two groups: The robotic biopsy group (n = 15) underwent a frameless image-guided stereotactic intracranial biopsy with a Stealth Autoguide Robotic Platform and optical neuronavigation system (Stealth-Station S8, Medtronic, Minneapolis, MN, USA) using intraoperative sodium fluorescein. The frame-based (Integra, CRW, New Jersey, USA) stereotactic biopsy group (n = 15) underwent a stereotactic biopsy with the use of a stereotactic planning system (Atlas Integra Software, NJ, USA and Brainlab AG, Munich, Germany) without sodium fluorescein. Preoperative MRI and CT scans were performed in all the patients. Their external cranial anatomy was registered using either facial tracing or O-Arm (Medtronic Sofamor Danek, Inc., Memphis, TN, USA). Results: The robotic biopsy group demonstrated a diagnostic yield of 93.3% (14/15), while the frame-based group achieved 100% (15/15), with no significant difference (p = 0.609). The mean calculated tip error in the robotic biopsy group was 0.42 ± 0.19 mm (range: 0.1–0.7 mm) and the postoperative targeting accuracy in the frame-based biopsy group was 0.51 ± 0.23 mm (range: 0.2–0.9 mm), with no significant difference (p = 0.287). The robotic biopsy group demonstrated a significantly shorter mean surgical time (40.26 ± 6.13 vs. 52.47 ± 8.92 min, p = 0.002). Conclusions: Both frame-based and robotic-assisted stereotactic biopsy techniques achieve comparable diagnostic accuracy and targeting precision. However, a robotic biopsy significantly reduces the surgical time compared to a frame-based technique. The use of intraoperative sodium fluorescein is a valuable adjunct method for confirming that biopsy specimens are obtained from the intended target site. Full article

Epoxy materials are an important class of thermosets whose properties strongly depend on the used formula, the curing parameters, and many available hardeners. Achieving desired properties such as enhanced thermal stability, extended lifetime, or self-regeneration requires selecting suitable precursors and carefully tuning curing conditions. In this work, a selected biphenyl epoxy precursor was used as a model compound to assess whether using different hardeners could be an effective factor in tailoring the elasticity of cured epoxy networks. We employed two chemically distinct hardeners—4,4′ diaminodiphenylmethane (DDM) and suberic acid—to generate materials with markedly different final properties. For instance, the glass transition temperature T_g varied within a range of over 35 °C. Two complementary experimental techniques were used in this paper to establish the optimal curing parameters: differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS). Both techniques supported tracking of changes in the mixture while curing and enabled determination of T_g in the obtained products. Dielectric relaxation spectroscopy revealed various molecular motions (α, β, and γ-processes) occurring in different phases, especially in glass-forming solids. BDS is therefore a good tool for testing new organic materials. The analytic route used in this work, based on a combination of calorimetric and electrical approaches, enables precise adjustment of the curing parameters to a specific hardener and helps verify the effects of using different hardeners on the elastic properties of the product. This allows the creation and modification of epoxy matrices towards modern materials, such as composites with self-healing properties or enhanced thermal stability. Full article