Abstract – The Kretschmann configuration is a well-established method for exciting surface plasmons, widely used in optical sensing through Surface Plasmon Resonance (SPR). This study presents a comparative analysis of the sensitivity of Kretschmann-based SPR structures using gold (Au) and silver (Ag) as plasmonic layers. Both simulation and experimental results were used to evaluate the optical response of each metal under varying refractive indices of the surrounding medium.

The findings indicate that silver exhibits a narrower resonance curve and slightly higher sensitivity in terms of angular shift per refractive index unit (RIU), due to its lower optical losses. However, gold offers superior chemical stability, making it more suitable for practical and long-term applications, despite having a broader resonance

The system was modelled using the transfer matrix method (TMM) to simulate the reflectance of a p-polarized light beam incident on a multi-layer structure composed of a BK7 glass prism, a thin metal film (either Au or Ag), and a dielectric sensing medium. The metal layer thickness was optimized to ensure efficient plasmon excitation. Refractive index changes in the sensing medium (from 1.33,1.38) were introduced to assess angular sensitivity. Optical constants for Au and Ag were taken from experimental data (e.g., Johnson and Christy).

The use of 3D-printed tablets for drug delivery has recently gained significant attention [1]. In this study, we have used commercially available polyvinyl alcohol (PVA) filaments (Smartfil PVA, Smart Materials 3D, based on Mowiflex C17, Kuraray) to incorporate model drugs from saturated solutions in absolute ethanol. Biocompatibility assays were conducted on the filament using HaCaT cells to confirm its non-toxic properties using an MTS assay. Cell viability on the material surface was 80.96 ± 5.13%, while cells treated with extracts from the material showed a viability of 102.57 ± 5.23%, indicating that the material is non-cytotoxic. Loading the filament with fluorescein using a saturated ethanolic solution enabled the production of luminescent printed tablets using a Creality Ender 6 FDM 3D Printer [2]. However, when attempting to load previously printed pristine PVA tablets, the printed layers disaggregated when the immersion time was prolonged. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) of 3D-printed tablets made from pure PVA and fluorescein-loaded PVA filaments revealed differences in their thermal degradation behavior. X-ray photoelectron spectroscopy (XPS) data confirmed the semicrystalline nature of the pristine PVA tablets. The percentage of crystallinity decreased when the sample was loaded with fluorescein by immersion, but increased when using a fluorescein-loaded PVA filament to obtain the fluorescein-loaded tablets. Fast Fourier Transform Infrared Spectroscopy (FT-IR) on the 3D-printed tablets allowed us to identify the incorporation of fluorescein and its impact on the PVA chemical structure for the different tablets. Atomic Force Microscopy (AFM) and Ultrasonic Force Microscopy (UFM) provided valuable insights into the nanoscale morphology and elastic homogeneity of the 3D-printed samples.

[1] H. Iqbal, Q. Fernandes, S. Idoudi, R. Basineni, N. Billa, Polymers 16, 386 (2024).

[2] A. Goyanes, A. B. M. Buanz, A. W. Basit and S. Gaisford, Int J Pharm 88 (2014)

This study presents the development of polymer-based nano/micromotors fabricated through electropolymerization for biomedical applications. polymer-based motors were synthesized using template-assisted electropolymerization with optimized electrochemical parameters. The electropolymerization process was systematically characterized using cyclic voltammetry (CV) techniques to ensure reproducible fabrication conditions. Surface modification strategies were employed to enhance motor functionality, including covalent attachment of bioactive molecules and incorporation of targeting ligands. Electrochemical impedance spectroscopy confirmed successful surface functionalization and maintained structural integrity of the polymer matrix during fabrication processes. Comprehensive biocompatibility studies confirmed their excellent suitability for biological environments, while inherent biodegradability eliminates long-term accumulation concerns in living systems. The biomedical applications investigated include targeted drug delivery systems, bacterial removal mechanisms, and advanced biosensing platforms. The motors demonstrated excellent biocompatibility in cell culture studies and promising controlled drug release properties with sustained therapeutic efficacy. Metallic bilayer variants and strategic incorporation of metallic nanoparticles into the chitosan matrix significantly enhance electrochemical activity and provide multifunctional properties for targeted therapy and imaging applications. Electrochemical surface functionalization enables specific targeting capabilities for precision medicine approaches. Results demonstrate the significant potential of electropolymerized polymer nano/micromotors as next-generation biomedical devices, offering unique advantages of controllable electrochemical propulsion, excellent biocompatibility, and complete biodegradability for various clinical applications.

Accurate, non-invasive temperature monitoring is vital for biomedical diagnostics and therapies, yet conventional thermometry often suffers from its invasiveness and limited tissue penetration. In this work, we present Er³⁺ and Tm³⁺ co-doped TiO₂ nanofibers as high-performance optical nanothermometers operating within near-infrared (NIR) biological windows. The materials are synthesized via a hydrothermal route and structurally confirmed by XRD, SEM coupled with EDS, and TEM analyses, showing successful incorporation of lanthanide ions without compromising TiO₂ morphology. Under 532 nm excitation, the probes exhibit dual emission bands at approximately 797 nm (Tm³⁺: ³H₄ → ³H₆) and around 1000 nm (Er³⁺: ⁴I_11/2 → ⁴I_15/2), enabling fluorescence intensity ratio (FIR)-based thermometry. Remarkably, the system demonstrates anti-thermal-quenching behavior, with emission intensity increasing with temperature due to the synergistic effects of TiO₂ host structure and energy transfer between dopants. The optimized sensor achieves an exceptional relative sensitivity of 3.59 % K^-1 at room temperature and a temperature resolution less than 1 K over the 298-398 K temperature range. Validation in intralipid tissue phantoms confirms reliable signal detection up to 17.35 mm depth, highlighting suitability for deep-tissue applications. These findings establish TiO₂ nanofibers co-doped with Er³⁺ and Tm³⁺ ions as ultrasensitive and stable optical probes, with strong potential for real-time, non-invasive thermal monitoring in biological and medical environments.

Bone defects and fractures have emerged as a significant global health issue, primarily due to factors such as an aging population, osteoporosis, tumors, trauma, and orthopedic diseases. Consequently, more than four million surgical procedures utilizing bone grafts and replacement materials are performed annually, making bone the second most commonly transplanted tissue worldwide [1]. The global orthopedic implants market represents a vital and expanding sector within the medical industry, currently valued at approximately USD 48 billion in 2023, and expected to grow to USD 78 billion by 2033 [2]. The use of artificial bone implants is significant, as they mitigate the risk of disease transmission associated with autologous and allograft bone transplants, positioning them as a vital solution for the repair of damaged bones [1].

Metals such as stainless steel, cobalt–chromium (Co-Cr) alloys, and titanium-based alloys are vital materials used in strong and reliable medical implants. Titanium alloys, particularly Ti-6Al-4V, are the preferred choice for bone replacement because of their excellent biocompatibility and outstanding corrosion resistance [3].

This paper will present the biomedical potential of materials produced using SLM technology with different porosities and pore shapes. The results will show the relationship between the structure of the material and the observations from indirect and direct cytotoxicity tests, as well as direct proliferation for mouse pre-osteoblast cells (MC3T3-E1).

[1] Xu C., Qi. J., Zhang L., Liu Q., Ren L. (2023), Additive Manufacturing, 78, 103884.

[2] Orthopedic Implants Market Size, https://www.grandviewresearch.com/industry-analysis/orthopedic-implants-market

[3] Schöbel L., Ayerbe M.G., Polley C., Arruebarrena G., Seitz H., Boccaccini A.R. (2025) ACS Biomater. Sci. Eng. 11, 4057−4061.

The authors gratefully acknowledge the financial support of the project “New Generation of Bioactive Laser Textured Ti/Hap Implants” under the acronym “BiLaTex” carried out within M-ERA.NET 3 Call 2022 programme in the National Centre for Research and Development (registration no.: ERA.NET3/2022/48/BiLaTex/2023).

Plasmonic metasurfaces with engineered subwavelength geometries enable extraordinary electromagnetic transmission and have attracted enormous attention for applications in nanofabrication, sensing, imaging, and wireless communications. At terahertz D-band (0.1-0.3 THz) frequencies, where ultra-broadband, short-range communication systems are emerging, achieving efficient wave control remains a critical challenge due to material losses and scalability limitations.

We present a systematic study of resonant transmission behaviors of plasmonic arrays consisting of subwavelength rectangular apertures, for the first time to our knowledge, at D-band communication frequencies. Terahertz time-domain spectroscopy (THz-TDS) was employed to characterize the amplitude and polarization response of the array samples with varying aperture widths. Numerical simulations using CST Microwave Studio were carried out to analyze the field distributions and underlying resonance mechanisms. Both experimental measurements and numerical simulations demonstrate that the transmission properties are highly sensitive to aperture width and polarization orientation. For the x-polarized incidence, a dominant resonance peak near 0.165 THz was observed, with transmission amplitude increasing with aperture width. Extraordinary transmission exceeding unity, when normalized to aperture area, was attributed to the combined excitation of dipolar localized surface plasmons, surface plasmon interactions, and non-resonant scattering. In contrast, the y-polarized incidence produced sharper resonances and stronger transmission, particularly at an aperture width of 350 μm. Field distribution analysis confirmed the polarization-dependent resonance strength and its attenuation at narrower apertures.

Our findings provide new insights into the modal coupling and extraordinary transmission mechanisms of subwavelength terahertz metasurfaces. The demonstrated tunability of resonance frequency and field confinement highlight their potential in developing compact, reconfigurable, and efficient frequency-selective components such as filters, reflectors, and modulators for next-generation short-range, high-data-rate terahertz wireless communication systems.

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide, highlighting the urgent need for advanced vascular substitutes able to overcome the limitations of currently available grafts in vascular medicine. The conventional paradigm of vascular tissue engineering, where vascular scaffolds (VSs) are conceived merely as passive artery-mimicking frameworks, has evolved toward a dynamic vision in which they actively interact with host cells after implantation. Next-generation VSs should not only provide mechanical support but also attract and guide cells, modulate post-surgery inflammation, regulate scaffold remodeling, and enable the controlled release of bioactive molecules, such as antioxidants or growth factors, to promote functional neovessel regeneration.

We developed biodegradable, bioabsorbable, and small-diameter (< 6 mm) electrospun VSs integrating superparamagnetic iron oxide nanoparticles (SPIONs) to enable noninvasive, nondestructive, and real-time tracking of VS performance. The VSs were fabricated by electrospinning, using poly(ε-caprolactone) and poly(glycerol sebacate) (20% (w/v) each) at a 1:1 (v/v) ratio enriched with 0.05% (w/v) quercetin. SPIONs, incorporated at different concentrations, could allow magnetic resonance imaging (MRI)-based monitoring of VS positioning, evaluation of structural integrity, and assessment of fiber degradation kinetics both in vitro (i.e., during dynamic testing in bioreactor) and in vivo. Scanning electron microscopy confirmed the uniform distribution of SPIONs within the fibrous architecture. The VSs were comprehensively characterized for physicochemical properties, mechanical behavior, and bioactive molecule release kinetics, while MRI testing demonstrated strong and stable signal retention over time. Cytocompatibility was evaluated with human endothelial cells and hemocompatibility was assessed with human red blood cells, taking into consideration blood coagulation kinetic and hemolysis assays.

This multifunctional platform combines regenerative, anti-inflammatory, and imaging functionalities within a single construct, paving the way for smart VSs capable of guiding tissue regeneration while enabling continuous, noninvasive monitoring and representing a promising step toward precision cardiovascular medicine.

Introduction:
Superconductors (R=0) are excellent electrical conductors with useful magnetic properties. This has allowed many useful applications (like high-current-carrying superconducting (SC) wires) for decades. Iron-based superconductors—especially iron pnictides and chalcogenides—have recently generated attention. On one hand, they can be SC up to a high superconducting critical temperature (Tc) of 58 K in spite of the high fraction of magnetic ions (Fe), and on the other hand, they have potential as wires for high-field SC magnets. However, further enhancement of Tc remains a key research objective for practical applications.

Methods:
We explore here the effects of ion implantation on underdoped Ba(Fe₀.₉₄₃Co₀.₀₅₇)₂As₂ single crystals. Irradiation was with 1.5 MeV Ar⁶⁺ ions at a fluence of 2.5 × 10¹⁵ ions/cm². Magnetic susceptibility (both real and imaginary components) and electrical resistivity were measured before and after irradiation.

Results:
Following irradiation onset, Tc rose from 16.9 K to 25.2 K, as measured from the real part of magnetic susceptibility—a rise of 8.3 K. Comparable enhancements were seen for the imaginary part of susceptibility (8.1 K) and resistivity measurements (7.8 K). These results significantly exceed previously reported [1] Tc shift (typically <1 K) cases of similar ion irradiations in related systems.

Conclusions:
The enhancement is attributed to a compressive strain [3] induced by high-pressure Ar micro-bubbles within the implanted layer, formed at depths up to the ion range (R) under conditions where sample thickness (t) ≫ R. This strain mimics external pressure, thereby promoting superconductivity. A similar Tc emergence in undoped BaFe₂As₂ supports this pressure-driven mechanism, highlighting ion implantation as a promising approach for Tc enhancement in superconductors.

References:

[1] T. Ozaki, L. Wu, C. Zhang, J. Jaroszynski, W. Si, J. Zhou, Y. Zhu, Q. Li, Nat. Commun. 7 (2016) 13036(1-9).

[2] Kriti R Sahu, Th. Wolf, A K Mishra, Keka R. Chakraborty, A Banerjee, V Ganesan, Udayan De, Physica C: Superconductivity and its applications, 635, 1354733, 2025

Ferrimagnets are described by molecular field models, which operate by summing sublattice magnetic moments with Brillouin functions. They are commonly initialized with the fully saturated ("spontaneous") moment M_s(T), obtained by extrapolating the high-field portion of M(H) hysteresis curves to zero-field. However, the bulk polycrystalline ferrimagnetic samples used in our experiments were measured in their remanent state, so the directly observed moment M_r(T) can differ significantly from M_s(T), leading to model and experiment mismatches of up to ~3x. We derive a practical connection between M_s(T) from the molecular field model and the experimental M_r(T). Our approach introduces a correction factor β(T) = M_r/M_s derived from hysteresis curves of our sample that can be folded back into the molecular field fit. Applying this correction to polycrystalline terbium iron garnet yields good agreement between the modeled and measured magnetization in the relevant temperature range, especially near the compensation temperature, which is where the richest physics resides. In addition, the corrected model reproduces the measured neutron spin rotation of our samples that depend on the internal magnetization of the sample. This explicit treatment of the remanent state reconciles the molecular field model with measurements on actual rare-earth iron garnet targets, providing a backbone to the results of the NSR-Ferrimagnets collaboration and other exotic force-searching experiments using ferrimagnets.

This study investigates the effect of fibre length on the mechanical performance of epoxy bio-composites reinforced with Gigantochloa Albociliata (Malaysian honey bamboo) fibres. The composites were fabricated via hand lay-up using short fibres (3 cm, Sample II), medium fibres (6 cm, Sample III), and long fibres (12 cm, Sample IV). All fibres underwent 6 wt% NaOH treatment under heterogeneous conditions, which involved either immersion for 24 hours at 65 °C, followed by oven drying, or extended immersion for 48 hours at room temperature with subsequent air drying. Fibre volume fractions ranged from 5% to 20%. Tensile tests revealed a consistent improvement in strength and stiffness with increasing fibre length and content. Short-fibre composites (Sample II) achieved up to a 43.2% increase in tensile strength over neat epoxy, while medium fibres (Sample III) recorded gains of 49.0%. The most pronounced enhancement was observed in the long-fibre composites with 48 hours of treatment (Sample IV), where the 20% loading (IV-D) achieved the highest tensile strength (53.71 MPa) and Young’s modulus (1788.1 MPa), reflecting improvements of 115.8% and 62.6%, respectively, compared to neat epoxy (24.9 MPa, 1100.5 MPa). However, ductility declined, with strain at break reducing from 3.7% in neat epoxy to 1.98% in composite IV-D, reflecting the trade-off between stiffness and flexibility. These results confirm fibre geometry and treatment protocol as critical design factors, with longer fibres providing superior reinforcement efficiency. Overall, Gigantochloa Albociliata demonstrates strong potential as a sustainable reinforcement for high-performance bio-composites in load-bearing applications.