Search Results (886)

The structural units with different characteristic scales in gradient nanostructured (GS) 316L stainless steel act synergistically to achieve the matching of strength and plasticity, and the intrinsic plasticity of nanoscale and ultrafine grains is fully demonstrated. The macroscopic stress–strain responses of each material unit in the GS surface layer can be measured directly by tension or compression tests on microspecimens. However, the experimental results based on microspecimens do not reflect either the extraordinary strengthening effect caused by non-uniform deformation or the intrinsic plasticity of nanoscale and ultrafine grains. In this paper, a method for constructing depth-dependent constitutive relationships of GS materials was proposed, which combines strain hardening parameter (hardness) with physics-informed neural networks (PINNs). First, the microhardness distribution on the specimen cross-sections was measured after stretching to different strains, and the hardness–strain–force test data were used to construct the depth-dependent PINNs model for the true strain–hardness relationship (PINNs_εH). Hardness–strain–force test data from specimens with uniform coarse grains were used to pre-train the PINNs model for hardness and true stress (PINNs_Hσ), on the basis of which the depth-dependent PINNs_Hσ model for GS materials was constructed by transfer learning. The PINNs_εσ model, which characterizes the depth-dependent constitutive relationships of GS materials, was then constructed using hardness as an intermediate variable. Finally, the accuracy and validation of the PINNs_εσ model were verified by a three-point flexure test and finite element simulation. The modeling method proposed in this study can be used to determine the position-dependent constitutive relationships of heterogeneous materials. Full article

Resistive stretching sensors are currently used in healthcare robotics due to their ability to vary electrical resistance when subjected to mechanical strain. However, commercial sensors often lack the softness required for integration into soft structures. This study presents a detailed methodology to characterize fabric-based resistive stretching sensors, focusing on both static and dynamic performance, for application in a smart vascular simulator for surgical training. Five sensors, called #1–#5, were developed using conductive fabrics integrated into soft silicone. Stability and fatigue tests were performed to evaluate their behavior. The surface structure and fiber distribution were analyzed using digital microscopy and scanning electron microscopy, while element analysis was performed via Energy-Dispersive X-ray Spectroscopy. Sensors #1 and #3 are the most stable with a low relative standard deviation and good sensitivity at low strains. Sensor #3 showed the lowest hysteresis, while sensor #1 had the widest operating range (0–30% strain). Although all sensors showed non-monotonic behavior across 0–100% strain, deeper investigation suggested that the sensor response depends on the configuration of conductive paths within and between fabric layers. Soft fabric-based resistive sensors represent a promising technical solution for physical simulators for surgical training. Full article

A numerical simulation experiment is conducted to study the first-ever waterspout observed in Victoria Harbour, Hong Kong, in 2024, namely, a mesoscale meteorological model with a spatial resolution of 200 m coupled with a computational fluid dynamics model with a spatial resolution of 4 m. It is found that the simulation could reproduce the observed wind field near the surface reasonably well, as well as the location of the waterspout and showers, as shown in the weather image. By conducting simulations with and without buildings, it is found that the inclusion of buildings is essential for the successful reproduction of the flow fields near the surface and up to several hundred metres high. This may suggest that urbanization plays a role in the occurrence of this waterspout. The resultant horizontal vorticity is then stretched by strong vertical motion at around 850 hPa, resulting in the waterspout, though no closed circulation could be simulated at the location of the waterspout. Moreover, the cyclonic feature for the flow field near the surface has a time lag of about 30 min compared with the actual waterspout occurrence. Nonetheless, the simulation is considered to be generally satisfactory and provides useful insight into the occurrence of the waterspout. Full article

In clinical applications of surface-enhanced Raman spectroscopy (SERS) immunosensors, accurately determining analyte biomarker concentrations is essential. This study presents a non-invasive approach for quantifying various breast cancer biomarkers—including human epidermal growth factor receptor II (HER-II) (2+, 3+ (I), 3+ (II), 3+ (III), and positive IV) and CA 15-3—using a directional, plasmonically active, label-free SERS sensor. Each stage of sensor functionalization, conjugation, and biomarker interaction was verified by UV–Vis spectroscopy. Atomic force microscopy (AFM) characterized the morphology of gold nanourchin (GNU)-immobilized printed circuit board (PCB) substrates. An enhancement factor of ≈ 0.5 × 10⁵ was achieved using Rhodamine 6G as the probe molecule. Calibration curves were initially established using standard HER-II solutions at concentrations ranging from 1 to 100 ng/mL and CA 15-3 at concentrations from 10 to 100 U/mL. The SERS signal intensities in the 620–720 nm region were plotted against concentration, yielding linear sensitivity with R² values of 0.942 and 0.800 for HER-II and CA15-3, respectively. The same procedure was applied to breast cancer serum (BCS) samples, allowing unknown biomarker concentrations to be determined based on the corresponding calibration curves. SERS data were processed using the filtfilt filter from scipy.signal for smoothing and then baseline-corrected with the Improved Asymmetric Least Squares (IASLS) algorithm from the pybaselines.Whittaker library. Principal Component Analysis (PCA) effectively distinguished the sample groups and revealed spectral differences before and after biomarker interactions. Key Raman peaks were attributed to functional groups including N–H (primary and secondary amines), C–H antisymmetric stretching, C–N (amines), C=O antisymmetric stretching, NH₃⁺ (amines), carbohydrates, glycine, alanine, amides III, C=N stretches, and NH₂ in primary amides. Full article

Hydrogels have immense potential in soft electronics due to their similarity to biological tissues. However, for applications in fields like tissue engineering and wearable electronics, hydrogels must obtain electrical conductivity, stretchability, and implantability. This article explores recent advancements in the development of electrically conductive hydrogel composites with high conductivity, low Young’s modulus, and remarkable stretchability. By incorporating conductive particles into hydrogels, such as poly(3,4-ethylenedioxythiophene)/poly (styrenesulfonate) (PEDOT/PSS) researchers have enhanced their conductivity. This study presents a one-pot synthesis method for creating electrically conductive hydrogel composites by combining PEDOT/PSS with alginate. The hydrogel reveals changes in chemical composition upon treatment with dimethyl sulfoxide (DMSO). Additionally, surface morphology analysis via Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) demonstrate the impact of DMSO treatment on PEDOT/PSS/alginate films. Furthermore, electrical conductivity measurements highlighted the effectiveness of the conductive hydrogels in Electromyography (EMG) and human motion detection. This study offers insights into the fabrication and characterization of stretchable, conductive hydrogels, advancing their potential for various soft sensing biomedical applications. The optimized PDOT/PSS/alginate composite under dry condition shows a conductivity of 0.098 S/cm and can be stretched without significant loss in conductivity or mechanical stability. This one-pot method provides a simple and effective way to improve the properties of conductive hydrogel-based sensors. Full article

In the production of a digital orthophoto map (DOM) from unmanned aerial vehicle (UAV)-acquired overlapping images, some anomalies such as texture stretching or data holes frequently occur in water areas due to the lack of significant textural features. These anomalies seriously affect the visual quality and data integrity of the resulting DOMs. In this study, we attempted to eliminate the water surface anomalies in an example DOM via replacing the entire water area with an intact one that was clipped out from one single UAV image. The water surface scope and boundary in the image was first precisely achieved using the multisource seed filling algorithm and contour-finding algorithm. Next, the tie points were selected from the boundaries of the normal and anomalous water surfaces, and employed to realize their spatial alignment using affine plane coordinate transformation. Finally, the normal water surface was overlaid onto the DOM to replace the corresponding anomalous water surface. The restored water area had good visual effect in terms of spectral consistency, and the texture transition with the surrounding environment was also sufficiently natural. According to the standard deviations and mean values of RGB pixels, the quality of the restored DOM was greatly improved in comparison with the original one. These demonstrated that the proposed method had a sound performance in restoring abnormal water surfaces in a DOM, especially for scenarios where the water surface area is relatively small and can be contained in a single UAV image. Full article

In order to improve the uniformity of microwave heating, moving components are often added to the cavity. For higher uniformity or greater industrial processing capacity, samples often perform large-scale movements such as rotating and lifting motion or translational motion on a conveyor belt. The microwave heating algorithm based on the ray-casting method (RCM), as proposed in previous studies, can calculate moving complex-shaped samples, but the calculation efficiency is low when the sample moves on a large scale due to the large refined mesh area. To solve this problem, this study introduced a moving mesh combined with the RCM for calculation purposes. A microwave oven model with a rotating and lifting turntable was selected for the analysis. First, the calculation area was divided into a sliding mesh and a telescopic mesh area. The telescopic mesh area was stretched or compressed at different times, which was equivalent to the translational motion of the sample. Then, the electromagnetic parameters were assigned to each mesh point in combination with the boundary recognition algorithm based on the ray-casting method, and the horizontal motion was calculated while calculating the large-scale translation. The proposed method only needs to refine the mesh in the horizontal motion area, which reduces the number of overall meshes. The electromagnetic field distribution obtained by the model during the heating process was verified by the discrete position method. The surface temperature distribution and the real-time curve of the center point temperature were further compared with the RCM. The results show that the average error of the sample center temperature is 2.5% and the calculation time was reduced to 9.8%, which verified the accuracy and efficiency of the proposed method. Finally, the influence of different lifting and rotating speeds on the heating effect was further explored. Full article

Urbanization and cropland irrigation modify land surface water and energy budgets in different ways; however, few observational studies have explicitly quantified their contrasts. Using high-resolution observations from over 2000 surface weather stations and urban and irrigation fraction data, this study investigated the individual and combined effects of urbanization and cropland irrigation on surface air temperature over the Beijing–Tianjin–Hebei (BTH) region in China, where highly urbanized areas and heavily irrigated croplands exist together. The results indicate that (1) the daytime irrigation cooling (with surface air temperature decreasing by ~0.1–0.5 °C at irrigated stations) was non-negligible in late autumn, early winter, and later spring months, when winter wheat irrigation mainly occurred over the BTH region, while a slight warming was observed at many irrigated stations during the nighttime. By contrast, urban warming was most pronounced in the nighttime, especially in winter, and the daytime warming at urban sites was much weaker and comparable to the magnitude of cooling induced by concurrent irrigation for winter wheat. (2) Collectively, the vast stretches of irrigated croplands helped mitigate urban warming, and their combined effect on the daytime surface air temperature over the whole region resulted in a slight cooling of ~0.2 °C in some of the winter wheat-growing months. (3) The contrasting temperature changes due to urbanization and irrigation were spatially variable. Beijing was predominantly characterized by urban warming, while Shijiazhuang, with extensive irrigation, exhibited irrigation cooling (or slight warming) during the daytime (or nighttime) in most of the winter wheat-growing months, which could be a possible contributor to the daytime cooling (or stronger nighttime warming) at urban sites. This work highlights the temperature contrasts between urban areas and surrounding irrigated croplands, as well as the potential role of extensive irrigation in mitigating (or enhancing) daytime (or nighttime) urban warming. Full article

The defects in zinc oxide crystals are of crucial importance for their usability in many applications and are not yet fully understood. Here, we demonstrate that dioxygen species are present as defects in the grown ZnO, resulting in a bending of the atom layers that lie perpendicular to the c-axis. In the Raman spectra, these defects cause the appearance of bands different from the known bands of perfect ZnO crystals allowed by symmetry. These additional Raman bands, which have been frequently reported for ZnO in the past, can thus be fully explained by the presence of dioxygen species, and the widespread assumption of second-order modes for the assignments of these bands is not necessary. Furthermore, the Raman spectrum belonging to perfect zinc oxide in the ideal wurtzite structure is presented, obtained from small domains in ZnO(0001) crystals exposed to pressures up to 2 GPa. The dependence of the O-O stretching modes on the applied pressure proves the presence of dioxygen species in ZnO, which is also confirmed by phonon calculations of structure models with embedded dioxygen species. The surface quality of the ZnO crystals studied is also reflected in the Raman spectra and is included in the analysis. Full article

Background/Objectives: Carbohydrate antigen 125 (CA125) is a glycoprotein commonly overexpressed in epithelial ovarian cancer and widely recognized as a tumor marker. However, elevated CA125 levels are also observed in various non-malignant conditions, including diseases affecting mucosal surfaces, pleural or peritoneal effusions, cirrhosis (with or without ascites), endometriosis, uterine fibroids, adenomyosis, pelvic inflammatory disease, and pregnancy. This review aims to explore the role of CA125 in non-malignant serous effusions, highlighting its diagnostic and prognostic potential beyond the realm of oncology. Methods: A comprehensive literature search was conducted across multiple databases and clinical trial registries. Eligible studies included full-text original research articles, reviews, and case reports published in English over the past 10 years. Inclusion criteria were limited to studies involving human subjects and focused on the role of CA125 in non-malignant serous effusions. Results: CA125 is produced by coelomic epithelial cells lining the ovary, pleura, pericardium, and peritoneum. Its serum concentration is not significantly influenced by age, body weight, or renal function, even in the advanced stages of the disease. In peritoneal conditions, CA125 is synthesized by mesothelial cells and serves as a potential marker of peritoneal involvement. The prevailing pathophysiological mechanism suggests that mechanical stretching of mesothelial cells due to ascitic pressure stimulates CA125 release. Similarly, in heart failure, mesothelial cells of the pericardium produce CA125, which correlates with congestion severity, supports risk stratification, and may inform diuretic therapy. Conclusions: While a threshold of 35 U/mL is established for malignancy, no standardized cutoff exists for CA125 in non-malignant conditions. The utility of CA125 measurement in peritoneal, pleural, or pericardial effusions—and cardiovascular diseases such as acute heart failure—for purposes of differential diagnosis, treatment guidance, or prognostication warrants further investigation through prospective clinical trials. Full article

Significant heavy metals contamination is often caused by rapid industrialization, which is devastating to both public health and the environment. Conventional processes of metal removal also result in the accumulation of secondary waste. This work proposes the use of a novel fungal biomass (microwave heat dried) from Arthrinium malaysianum for the biosorption of toxic chromium. We have meticulously explored and investigated the interactions of hexavalent chromium with dried biomass using several cutting-edge techniques like FTIR for studying the involvement of functional groups on the biomass surface, XRD for the surface architecture changes after metal binding, XPS to unravel the reduction of hexavalent chromium into its non-toxic form, and FESEM-EDX for the visualization of the ultra-structure of fungal cell surface. The Langmuir isotherm demonstrates that the maximum removal capacity Q_max of Cr(VI) is 102.310 mgg⁻¹, at a pH of 3.5 with 100% removal of Cr(VI). There were substantial changes in the surface architecture during adsorption, confirmed by FESEM and AFM studies. FTIR and XPS data analysis indicated that carbonyl, hydroxyl, phosphate, and amine groups were responsible for the conversion of Cr(VI) (toxic) to Cr(III) (non-toxic). The IR spectra of biomass treated with Cr showed a decreased C-O stretching intensity and slight shriveling of the -OH band, and the bands in the FTIR spectra at 1642 cm⁻¹ to 1635 cm⁻¹ and at 1549 cm⁻¹ to 1547 cm⁻¹ shifted and appeared quite distinct. XRD revealed that the chromium-treated biomass had greater crystalline features and also the appearance of a wide peak where 2θ = 20°, approximately, indicating an amorphous nature at 576.0 eV and in highly loaded chromium (500 mg/L) biomass, with the Cr2p level displaying a slight shift, eventually terminating in a (576.0 eV) Cr₂O₃ to Cr(III) peak. Since the FTIR and XPS data obtained revealed that Cr(VI) reduces to Cr(III), this fungal biomass can also be used for generating metallic nanoparticles during biosorption. Thus, we suggest that the above-mentioned fungal biomass could be a very useful biomaterial for future translational research. We are in the process of fabricating beads with powdered biomass for further studies. Full article

Nanomedicine is rapidly evolving, with tailored nanoparticles enabling precise cellular-level interventions. Despite significant advances, challenges, such as rapid clearance and off-target effects, hinder the clinical translation of many nanosystems. Among the available nanoplatforms, gold nanoparticles (AuNPs) stand out due to their unique surface chemistry, low toxicity, and excellent biocompatibility. In this work, we present a multi-level computational investigation of ultra-small AuNPs coated with non-conventional amphiphilic polymer chains via atomistic and coarse-grained molecular dynamics. Through high-level-resolution atomistic simulations, we investigate how variations in grafting density impact the collective behaviors of these amphiphilic polymer chains within the coating by quantifying relevant conformational, structural, and energetic descriptors, such as the radius of gyration, terminal group presentation, polymer coating thickness, brush height, and solvation energy. Our results reveal a conformational shift of polymer chains from coiled to stretched as grafting density increases, with a direct effect on the polymer conformational regime, terminal group presentation, and coating thickness. In parallel, we further benchmark low-level coarse-grained models using the atomistic data as a reference, demonstrating their ability to correctly reproduce the atomistic trends. This computational investigation reveals how key descriptors vary with grafting density and provides the tools for conducting similar studies on broader time and length scales, thereby advancing the rational design of nanosystems for nanomedicine. Full article

When developing fabrics for applications in which evaporative cooling and drying play an important role, e.g., sports or occupational applications, the drying performance of fabrics is commonly determined using fast and easy-to-perform benchmark methods. The measurement conditions in these methods, however, differ significantly from the drying conditions on the human body surface, where drying is obstructed on one side of the fabric through contact with the skin and at the same time enhanced due to contact with the heated surface (skin). The aims of this study were to understand and quantify the fabric drying process at the skin interface considering these real-use effects based on tests applying two-sided drying, one-sided drying, one-sided drying on a heated surface, and one-sided drying on a heated surface in the stretched state, and to relate these to existing standard methods. The findings showed that contact with a solid heated surface such as the skin and the stretched state of the fabric both make a significant contribution (p < 0.05) to the drying rate compared to two-sided drying in standard climatic conditions. The corresponding drying rates observed for a range of typical fabrics used in leisure and sports as a first layer next to the skin were found to be 1.6 (±0.2), 1.1 (±0.2), 7.9 (±2.1), and 10.6 (±0.8) g/m² min for two-sided drying, one-sided drying, one-sided drying on a heated surface, and one-sided drying on a heated surface in the stretched state, respectively. These findings are of great importance for human thermal modelling, including clothing models, where the drying process significantly contributes to the heat and mass transfer in the skin–clothing–environment system. Full article

The current work examines the effect of acetone on the electrochemical characteristics of a polycrystalline nickel electrode in a 0.1 M NaOH electrolyte, with respect to the kinetics of alkaline water electrolysis (HER: hydrogen evolution reaction, and OER: oxygen evolution reaction). Cyclic voltammetry (CV) and impedance spectroscopy (EIS) electrochemical techniques were employed to examine these processes for acetone concentrations stretching from 1.0 × 10⁻⁷ to 1.0 × 10⁻³ M. The introduction of small amounts of (CH₃)₂C=O clearly facilitated the catalytic efficiency of both examined electrochemical gas evolution processes. The latter is believed to result from a significant reduction in the surface tension parameter, due to the mutual interactions of acetone and water molecules, thus facilitating the detachment of gas bubbles from the nickel electrode surface. These findings suggest considerable opportunities for the introduction of tiny amounts of organic additives into alkaline electrolytes to improve the industrial alkaline water electrolysis process that is performed on technologically valuable electrode materials. Full article

This research focuses on creating CuO/PANI nanocomposite films by electrodepositing copper oxide nanoparticles into a polyaniline matrix on ITO substrates. The CuO nanoparticle content was adjusted between 7% and 21%. These nanocomposites are promising for various applications, such as optoelectronic devices, gas sensors, electromagnetic interference shielding, and electrochromic devices. We utilized UV-Vis spectroscopy to examine the nanocomposites’ interaction with light, allowing us to ascertain their refractive indices and absorption coefficients. The Scherrer formula facilitated the determination of the average crystallite size, shedding light on the material’s internal structure. Tauc plots indicated a reduction in the energy-band gap from 3.36 eV to 3.12 eV as the concentration of CuO nanoparticles within the PANI matrix increased, accompanied by a rise in electrical conductivity. The incorporation of CuO nanoparticles into the polyaniline matrix appears to enhance the conjugation length of PANI chains, as evidenced by shifts in the quinoid and benzenoid ring vibrations in FTIR spectra. SEM analysis indicates that the nanocomposite films possess a relatively smooth and homogeneous surface. Additionally, FTIR and XRD analyses demonstrate an increasing degree of interaction between CuO nanoparticles and PANI chains with higher CuO concentrations. At lower concentrations, interactions were minimal. In contrast, at higher concentrations, more significant interactions were observed, which facilitated the stretching of polymer chains, improved molecular packing, and facilitated the formation of larger crystalline structures within the PANI matrix. The incorporation of CuO nanoparticles resulted in nanocomposites with electrical conductivities ranging from 1.2 to 17.0 S cm⁻¹, which are favorable for optimum performance in optoelectronic devices. These results confirm that the nanocomposite films combine pronounced crystallinity, markedly enhanced electrical conductivity, and tunable band-gap energies, positioning them as versatile candidates for next-generation optoelectronic devices. Full article