Fourier Transform Research Articles

Dissecting Allosteric Mutations for Antibiotic Resistance by Time-Dependent Linear Response Theory.

We report a new approach that combines molecular dynamics trajectories with time-dependent linear response theory to compute the time evolution of residue fluctuation responses to force perturbations exerted at functional sites. Applying this new approach to TEM-1 beta-lactamase, we observe that the time-resolved response profiles of allosteric sites to perturbations of TEM-1 active sites are distinct from those of non-allosteric residues. Using Fourier transformations, we convert the time domain response profiles to the frequency domain and demonstrate that the frequency space representation of the perturbation response can capture the mutational behavior of each site when applied to deep sequencing mutational data. Furthermore, we show that classification models built on perturbation responses can accurately identify distal positions that regulate antibiotic resistance. These findings provide insights into the contributions of specific residues to resistance-encoded in time-resolved perturbation response behavior and highlight the importance of this new approach in identifying allosteric mutations, opening avenues for the potential characterization of additional allosteric positions without extensive computational simulations.

Tbx-Zn1-x-BDC MOF films synthesized in-situ by the aero-sol-assisted chemical vapor deposition

Tbx-Zn1-x-BDC MOF films were deposited in situ on glass substrates using the aerosol-assisted chemical vapor deposition (AACVD) technique with an ultrasonic spray pyrolysis system, with x ranging from 0 to 1. Various precursors and solvents were used in the precursor solutions, which were precisely nebulized onto the substrate. The resulting films were characterized using techniques such as x-ray diffraction, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and Photoluminescence Spectroscopy. The findings revealed the evolution of Zn-BDC and/or Tb-BDC crystalline structures within the films and changes in the physical properties of the Metal Organic Frameworks (MOFs), such as film thickness and roughness. Moreover, these insights offer vital information for the design and control of MOF films with specific properties, highlighting their potential applications in various fields.

Mechanical and Structural Characterization of Resole Resin Composites Reinforced with Sabai Grass-Derived Cellulose Fibers

Cellulose fibers were extracted from Sabai grass (Eulaliopsis binata) using mechanical and chemical treatments. The grass was ground to ~250 µm powder and bleached with hydrogen peroxide and acetic acid. The bleached fibers were treated with 6% sodium hydroxide solution and incorporated into resole resin at various weight percentages to prepare the composites. The prepared samples were characterized by X-ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and compressive strength tests. The XRD and FTIR showed a nanometric crystallite size of 3.84 nm and effective removal of non-cellulosic compounds, respectively, leading to a compressive strength increase from 15.60 MPa to 25.26 MPa at 3 wt.-% cellulose fiber. The compressive strength improved up to 3 wt.-% cellulose fiber, which however declined upon adding more filler. SEM revealed modified surface morphology in the composites with cellulose fibers.

Ascertaining the Peculiarities of Athletes’ Adaptation Course to Post-Sports Life

Objectives. The purpose of the study was to identify the peculiarities of athletes’ adaptation to post-sport life under modern conditions of reality. Materials and methods. The study involved 36 athletes, Masters of Sports, aged 25 to 40 years, who had finished their professional sports careers in disciplines such as ballroom dancing, artistic gymnastics, football, swimming, and judo. The study used methods of analysis and generalization obtained from scientific-methodical literature and internet data, surveys, and psychodiagnostics: the “Differential Emotions Scale” by C. Izard, adapted by A. Leonova, the “Meaningful Life Orientations” method by D. A. Leontiev, an adapted version of the “Purpose-in-Life Test” (PIL) by James Crumbaugh and Leonard Maholick, as well as the “Zimbardo Time Perspective Inventory” (ZTPI) by Zimbardo, P. G., & Boyd, J. N. During the study results’ analysis, the following methods were used: frequency analysis — identification of the frequency of each emotion category (absolute frequencies), and a calculation of percentage values (relative frequencies) for each category relative to the total number of participants. This was also applied to determine the number of athletes belonging to each category of future plans and to define the components of the time perspective; descriptive statistics — calculation of the mean value for each survey scale; these values were used to compare mean values between different scales and to analyze the variability of responses by calculating the standard deviation; percentage calculation. Results. This study examined the post-sport adaptation of 36 athletes using psychodiagnostic methods, thereby uncovering a complex emotional landscape and a variety of future perspectives. The survey results showed that 43% of the respondents had not yet decided what they wanted to become in their post-sports life, indicating significant stress, negative emotions, and physical and psychological problems that require attention and support. A significant portion (40%) of respondents affirmed that they could envisage their future without sports, with 25% choosing to become coaches and 15% interested in sports-related professions. Only 17% of respondents considered their future in other fields. The study also found that 42% of athletes reported having a strongly negative attitude towards leaving professional sports, experiencing feelings such as despair, grief, anger, disgust, and confusion. Another 36% of athletes characterized their emotional state as anxious-depressive, which also requires attention. Meanwhile, 22% of respondents stated a positive emotional attitude towards ending their careers, demonstrating interest in new circumstances and their future, which helps them to transition effectively into new lives. The study results on life orientations revealed that athletes tended to be more focused on past achievements and current goals than on the future, which may complicate their adaptation to post-sports life. Nevertheless, 37% of athletes are oriented towards a positive future and are willing to make efforts to achieve the necessary goals. Therefore, the findings clearly indicate the need for post-sports support and increased attention to the large proportion of former athletes (79%), whose mental health depends on the timeliness and speed of measures taken by specialists. Conclusions. The transition process for athletes after ending their professional careers to a life without sports is defined as individually nuanced, complex, and prolonged; it depends on past career success, is accompanied by stressful situations and negative emotions, and often requires a sudden conclusion to preserve the sense of being a champion.

A comparative study of sericin and gluten for magnetic nanoparticle-mediated drug delivery to breast cancer cell lines

With breast cancer emerging as a pressing global health challenge, characterized by escalating incidence rates and geographical disparities, there is a critical need for innovative therapeutic strategies. This comprehensive research navigates the landscape of nanomedicine, specifically focusing on the potential of magnetic nanoparticles (MNPs), with magnetite (Fe3O4) taking center stage. MNPs, encapsulated in biocompatible polymers like silica known as magnetic silica nanoparticles (MSN), are augmented with phosphotungstate (PTA) for enhanced chemodynamic therapy (CDT). PTA is recognized for its dual role as a natural chelator and electron shuttle, expediting electron transfer from ferric (Fe3+) to ferrous (Fe2+) ions within nanoparticles. Additionally, protein-based charge-reversal nanocarriers like silk sericin and gluten are introduced to encapsulate (MSN-PTA) nanoparticles, offering a dynamic facet to drug delivery systems for potential revolutionization of breast cancer therapy. This study successfully formulates and characterizes protein-coated nanocapsules, specifically MSN-PTA-SER, and MSN-PTA-GLU, with optimal physicochemical attributes for drug delivery applications. The careful optimization of sericin and gluten concentrations results in finely tuned nanoparticles, showcasing uniform size, enhanced negative zeta potential, and remarkable stability. Various analyses, from Dynamic Light Scattering (DLS) and scanning electron microscopy (SEM) to transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), and Thermogravimetric analysis (TGA), provide insights into structural integrity and surface modifications. Vibrating Sample Magnetometer (VSM) analysis underscores superparamagnetic behavior, positioning these nanocapsules as promising candidates for targeted drug delivery. In vitro evaluations demonstrate dose-dependent inhibition of cell viability in MCF-7 and Zr-75–1 breast cancer cells, emphasizing the therapeutic potential of MSN-PTA-SER and MSN-PTA-GLU. The interplay of surface charge and pH-dependent cellular uptake highlights the robust stability and versatility of these nanocarriers in tumor microenvironment, paving the way for advancements in targeted drug delivery and personalized nanomedicine. This comparative analysis explores the suitability of silk sericin and gluten, unraveling a promising avenue for the development of advanced, targeted, and efficient breast cancer treatments.

A study on thermal behaviour of thermal barrier coating: investigation of particle size, YSZ/polysilazane, time and temperature curing effect.

Thermal conductivity and adhesion strength effects were studied for thermal barrier coatings (TBCs) with different particle sizes, YSZ content, time, and temperature curing. The study involves three stages. The first step focuses on the characteristics of YSZ/polysilazane as the TBC, which is characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD), and Thermal Gravimetric Analysis (TGA). The second and third steps assess thermal conductivity and adhesion strength based on variables such as particle size, YSZ/polysilazane, time, and curing temperature. Results show that there was a synergistic effect between particle size-YSZ content and time-temperature curing to obtain specimens with good thermal properties. SB270/70 showed the lowest temperature compared to other specimens, up to 160 °C. Furthermore, YSZ/polysilazane thermal conductivity and adhesion properties could be enhanced by a prolonged curing time and higher temperature. This study emphasizes that the modification of particle size, YSZ content, time, and temperature curing is a promising strategy to improve the thermal properties of TBCs.

Titchmarsh’s-type theorem for two-sided quaternion Fourier transform and sharp Hausdorff–Young inequality for quaternion linear canonical transform

In this work, we first introduce the two-sided quaternion Fourier transform and demonstrate its essential properties. We generalize Titchmarsh’s-type theorem in the framework of the two-sided quaternion Fourier transform. Based on the interaction between the quaternion Fourier transform and quaternion linear canonical transform we explore sharp Hausdorff–Young inequality for the quaternion linear canonical transform. The obtained result can be considered as a generalized version of sharp Hausdorff–Young inequality for the two-dimensional quaternion Fourier transformation in the literature.

Effect of gold nanoparticle dispersion on the structural, optical and radiation shielding parameters of sodium Borate glass

Abstract Borate-derived radiation shielding glasses have been thoroughly explored, yet the effects of gold nanoparticle (GNP) dispersion on sodium borate glasses remain unstudied. This study investigates the impact of GNP dispersion and varying GNP concentrations on the radiation shielding properties and other parameters of sodium borate glass. All the glasses were prepared using the melt-quench technique with a composition of 30Na₂O-70B₂O₃, containing 0, 3 × 10⁸, and 3 × 10⁹ nanoparticles. The X-ray diffractogram confirmed the amorphous nature of the prepared glass samples, while Fourier Transform Infrared Spectroscopy (FTIR) confirmed structural modifications, indicated by the formation of non-bridging oxygens due to the incorporation of GNPs. High-resolution transmission electron microscopy (HR-TEM) confirmed the presence of GNPs with an average size of 1.317 nm, and Field Emission Scanning Electron Microscopy (FESEM) revealed further coagulation of GNPs into tiny grains to alleviate surface stresses. Density measurements showed a clear decrease from 2.3051 to 2.1363 g/cm³ with the incorporation of gold nanoparticles. Additionally, a localized surface plasmon resonance peak centered at 612 nm was observed in the UV‒Vis spectrogram of the glass with the highest GNP concentration. Radiation shielding parameters, including the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), and effective atomic number (Zeff), were analyzed using Phy-X/PSD software. The LAC value initially decreases from 78.046 to 72.330 cm⁻¹ with the incorporation of GNPs but increases to 77.846 cm⁻¹ with a higher GNP concentration. This glass system exhibited superior radiation shielding parameters compared to various reported glass systems, indicating its potential for shielding applications.

MCM-41 supported 2-aminothiophenol/Cu complex as a sustainable nanocatalyst for Suzuki coupling reaction

We have developed an innovative mesoporous nanocatalyst by carefully attaching a 2-aminothiophenol-Cu complex onto functionalized MCM-41. This straightforward synthesis process has yielded a versatile nanocatalyst known for its outstanding efficiency, recyclability, and enhanced stability. The structural integrity of the nanocatalyst was comprehensively analyzed using an array of techniques, including BET (Brunauer–Emmett–Teller) for surface area measurement, ICP (Inductively Coupled Plasma) for metal content determination, EDS (Energy-Dispersive X-ray Spectroscopy) for elemental mapping, XRD (X-ray Diffraction) for crystalline structure elucidation, SEM (Scanning Electron Microscopy), EMA (Elemental Mapping Analysis), TEM (Transmission Electron Microscopy), TGA (Thermogravimetric Analysis), FT-IR (Fourier Transform Infrared Spectroscopy), AFM (Atomic Force Microscopy), and CV (cyclic voltammetry). Subsequently, the catalytic properties of the newly developed MCM-41-CPTEO-2-aminothiophenol-Cu catalyst was evaluated in the synthesis of biphenyls, demonstrating outstanding yields through a Suzuki coupling reaction between phenylboronic acid and aryl halides. Importantly, this reaction was conducted in an environmentally friendly medium. Note the remarkable recyclability of the catalyst, proving its sustainability over six cycles with minimal loss in activity additionally hot filtration test was prepared to examine the stability of this nanocatalyst. This outstanding feature emphasizes the catalyst's potential for long-term, environmentally conscious catalytic applications.

Green synthesis of copper oxide nanoparticles using Rosmarinus officinalis leaf extract and evaluation of its antimicrobial activity

Due to the development of green technology, researchers are becoming more interested in low-cost, environmental eco-friendly methods for the synthesis of nanoparticles (Nps). In this work, Copper oxide nanoparticles (CuO Nps) were synthesized using a green synthesis technique, with Rosmarinus officinalis leaf extract acting as a capping and reducing agent. The as prepared the samples was characterized using UV-Visible Spectra (UV–VIS), X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and Scanning Electron Microscopy (SEM). The UV-Visible spectra result showed that strong absorption was observed for characteristic band of green synthesized CuO Nps and exhibit red shift as the weight fraction of CuO Nps increases. The XRD analysis confirmed the formation of CuO Nps, having a typical monoclinic structure with crystalline size ranging from 18 to 26 nm. From FTIR spectral analysis strong and broad peak observed at 3384 cm−1 can be attributed to (O-H) functional groups of the bioactive compounds which act as reducing and capping agents for the synthesis of CuO Nps in the plant extract. The SEM images of green synthesized CuO NPs was appeared to be aggregated form and almost spherical in shape. The antimicrobial activity of CuO Nps was evaluated against S.aureus and B.cereus (gram-positive), E. coli (gram-negative) bacteria strains and C.albicans fungal Pathogen. The result indicated that at weight fraction of 50 %, CuO Nps exhibit highest antimicrobial activity against E. coli, S. aureus, C.albicans and B.cereus with zone of inhibition of 26.0 ± 0.10, 25.0 ± 0.15, 18.1 ± 0.32 and 17.0 ± 0.0 mm respectively. Furthermore, for the E. coli bacterial strain, the minimum inhibitory concentration (MIC) of CuO Nps was found to be 1.56 mg/mL; whereas, for S. aureus and C. albicans was found to be 3.12 mg/mL. Therefore, the present study shows that Rosmarinus officinalis extract can be easily used as a reducing, stabilizing, and capping agent for the effective green synthesis of CuO Nps for antimicrobial agents. Thus, it is believed that synthesis of nanoparticles using low cost and eco-friendly green approach enhanced the antimicrobial activity and other a potentially applications in fields of biomedical.

Effect of magnesia additive on the morphology and physico‐mechanical properties of kaolinitic clays ceramics

AbstractNigeria is rich in various minerals, including crude oil and solid minerals. However, despite this abundance, effectively utilizing these resources remains a challenge. Kaolin, also known as white China clay, is a crucial raw material used in industries such as ceramics, paper, paint, plastic, and welding electrodes. Despite its plentiful availability in Nigeria, kaolin has not been adequately exploited. Consequently, Nigeria spends approximately 14.35 million USD annually to import refined kaolin to meet local demand, due to the lack of capacity to process it to the required industrial standards. This study investigates the effect of magnesia (MgO) on the morphology and physico‐mechanical properties of kaolinitic clay ceramics using the slip‐casting method. Various analytical techniques were employed to examine the kaolin, including X‐ray fluorescence (XRF), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). Also, compressive and flexural tests were conducted. The XRF analysis revealed that all samples contained SiO2 (54.41%wt), Al2O3 (34.05%wt), and other trace elements. The main mineral phases identified were quartz, microcline, and orthoclase. Among the samples, 30–200 exhibited the highest compressive strength at 218 MPa, while the highest flexural rigidity was observed in sample 15–200. The results indicated that MgO significantly affected the properties of kaolin, as the control sample had a compressive strength of 59 MPa. The study also found that the quantities of additives should align with stoichiometric requirements. Results showed hypo‐stoichiometry in samples 30–600 and 15–400, and hyper‐stoichiometry in sample 60–200. XRF, XRD, and FTIR spectra confirmed the elemental and chemical compositions of the samples, while SEM analysis revealed the morphological structure. It was observed that increasing the magnesia content from 10% to 30% led to an increase in pore spaces within the samples. TGA analysis provided insights into the relationship between mass loss and temperature variation in the ceramic samples, While The DTG curves explain the endothermic phase changes over changes in temperature; at 50–150°C, loss of the water phase is complete, at 300–400°C burning of organic matter phase is achieved and at 500–700°C endothermic dihyroxylation phase begins forming armorphous meta‐kaolin.

Synergistic Effects of Pea Protein on the Viscoelastic Properties of Sodium Alginate Gels: Findings from Fourier Transform Iinfrared and Large-Amplitude Oscillatory Shear Analysis

The rheological characteristics of pea protein (PP100%) and alginate (AG100%) as pure and mixed gels with different levels of pea protein (AP90:10, AP80:20, and AP70:30) were investigated via large-amplitude oscillatory shear (LAOS) and Fourier transform infrared (FTIR). Small-angle oscillatory shear (SAOS) was carried out for the samples, and a slight frequency dependence of the storage modulus (G′) and the loss modulus (G″) was observed for the pastes and gels, indicating the formation of a weak network, which is crucial for understanding the gel’s mechanical stability under small levels of deformation. Elastic and viscous Lissajous curves from the LAOS measurement at different levels of strain (1 to 1000%) elucidated that the mixed gels formed a strong network, which showed breakdown at high deformation (>100% strain). The synergistic strengthening of the network of the mixture was noticeable in the Fourier transform and Chevyshev harmonic analyses. This analysis indicated that the nonlinearity of e3/e1 and v3/v1 started at higher levels of strain for the mixed gels. The FTIR spectra revealed that there was no strong interconnection by crosslinking between pea protein and sodium alginate, indicating that the synergistic effect mainly came from electrostatic interactions. These findings suggest that combining alginate with pea protein can enhance the mechanical properties of gels, making them suitable for various food applications.

Optimization of iron nanoparticle sizethrough green synthesis using leaf extract from selective members of citrus family

Nanoparticles (NPs) are known for their unique attributes due to their small size that lies in atomic domain. The unique properties of NPs have prompted researchers to explore ways to make these materials with controlled size and morphology. The green synthesis of NPs is the most promising way of preparing NPs due to its convenience, environmentally friendly nature and cost effectiveness. This research work was mainly concerned with the green synthesis of iron nanoparticles (INPs) using three members of the citrus family (i.e., grapefruit, lemon, orange) under direct heating and ultrasound mediated conditions. The prepared NPs were investigated by different characterization techniques including Particle Size Analyzer (PSA), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The results revealed and demonstrated that the NPs thus formed differed not only in their sizes but also in the number of phases in PSA. The NPs prepared from extract of grapefruit leaves showed uniformity when lower concentration of extract was used; however, when higher volume were used formation of two phases was observed. In the case of ultrasound mediated synthesis, the formation of two phases was observed even at lower volume of grapefruit leave extract. In the case of nanoparticles (NPs) prepared using lemon leaf extract, both heating and ultrasound-mediated conditions resulted in the formation of multiple phases. Conversely, for NPs prepared with orange leaf extract, ultrasound-mediated conditions consistently led to the formation of a single phase, regardless of the volume of plant extract used. However, the size of these phases varied, showing an irregular trend with the volume of the plant extract. The FTIR spectra, DLS results, and SEM images reflected quite drastic differences in NPs before and after calcination. All synthesized NPs exhibited the same surface plasmon resonance of 700 nm.

Assessing the Compatibility of Menatetrenone with Excipients: A Spectroscopic Approach and Implication in Drug Formulation Development.

An experiment was conducted to evaluate the compatibility of menatetrenone with selected pharmaceutical excipients. Fourier Transform Infrared Spectroscopy (FTIR) was used to assess drug-excipient compatibility. The present research systematically investigates the FTIR spectrum of each chemical compound separately and their physical blends, analyzing for possible shifts, alterations or novel peak that may indicate chemical interactions. This study aims to utilize spectral data interpretation to detect potential compatibility problems that may occur while design and production of menatetrenone containing dosage forms ensuring their increased stability and effectiveness. The FTIR results demonstrated that all the pharmaceutical excipients were compatible with menatetrenone. In conclusion, the compatibility of pharmaceutical excipients with menatetrenone was successfully assessed using FTIR that will aid in future design of formulations containing menatetrenone as therapeutic moiety.

Atmospheric chemistry of CF3CHFCF2OCH3 (HFE-356mec3) and CHF2CHFOCF3 (HFE-236ea1) initiated by OH and Cl and their contribution to global warming.

The kinetic study of the gas-phase reactions of hydroxyl (OH) radicals and chlorine (Cl) atoms with CF3CHFCF2OCH3 (HFE-356mec3) and CHF2CHFOCF3 (HFE-236ea1) was performed by the pulsed laser photolysis/laser-induced fluorescence technique and a relative method by using Fourier Transform infrared (FTIR) spectroscopy as detection technique. The temperature dependences of the OH-rate coefficients (kOH(T) in cm3s-1) between 263 and 353K are well described by the following expressions: 9.93 × 10-13exp{-(988 ± 35)/T}for HFE-356mec3 and 4.75 × 10-13exp{-(1285 ± 22)/T} for HFE-236ea1. Under NOx-free conditions, the rate coefficients kCl at 298K and 1013mbar (760Torr) of air were determined to be (2.30 ± 1.08) × 10-13 cm3s-1and (1.19 ± 0.10) × 10-15 cm3s-1, for HFE-356mec3 and HFE-236ea1, respectively. Additionally, the relative kinetic study of the Cl + CH2ClCHCl2 reaction was investigated at 298K, as it was used as a reference reaction in the kinetic study of the Cl-reaction with HFE-356mec3 and discrepant rate coefficients were found in the literature. The global atmospheric lifetimes were estimated relative to CH3CCl3 at the tropospheric mean temperature (272K) as 1.4 and 8.6years for HFE-356mec3 and HFE-236ea1, respectively. These values combined with the radiative efficiencies for HFE-356mec3 and HFE-236ea1 derived from the measured IR absorption cross sections(0.27 and 0.41 W m-2 ppv-1) yield global warming potentials at a 100-yrs time horizon of 143 and 1473, respectively. The contribution of HFE-356mec3 and HFE-236ea1 to global warming of the atmosphere would be large if they become widespread increasing their atmospheric concentration.

Structural, morphological, and optical investigations of Mn-doped LaAlO3 perovskite obtained by microwave-assisted combustion and rapid calcination at low temperature

In this work, LaAlO3 perovskite was doped with 1, 2, 3, 5, 8, and 13 mol% of Mn using the microwave-assisted combustion method. The powders produced were heat treated at 700 °C and 900 °C for 10 min in an adapted microwave oven and then characterized by Thermogravimetric analysis (TG/DTG) and Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Rietveld refinement, X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Raman, Ultraviolet–Visible Reflectance (UV–Vis), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The materials produced doped with the highest concentration of Mn (13 %) showed a single-phase reduced crystallite size compared to the pure sample. The unit cell volumes increased compared to the pure material, while the oxidation state of the dopant was mainly Mn3+. The refinement data for the volume of the different polyhedral that comprise the LaAlO3 unit cell revealed a local change at both sites, which may also indicate Mn substitution at the A site. The heat treatment temperature did not change significantly, demonstrating the method's efficiency in producing perovskites at temperatures and times below those reported in the literature. The morphology observed was porous and irregular agglomerates, and the bandgap was 2.90 eV.

High-performance and wavelength-transplantable on-chip Fourier transform spectrometer using MEMS in-plane reconfiguration

On-chip spectrometers with high compactness and portability enable new applications in scientific research and industrial development. Fourier transform (FT) spectrometers have the potential to realize a high signal-to-noise ratio. Here we propose and demonstrate a generalized design for high-performance on-chip FT spectrometers. The spectrometer is based on the dynamic in-plane reconfiguration of a waveguide coupler enabled by an integrated comb-drive actuator array. The electrostatic actuation intrinsically features ultra-low power consumption. The coupling gap is crucial to the spectral resolution. The in-plane reconfiguration surmounts the lithography accuracy limitation of the coupling gap, boosting the resolution to 0.2 nm for dual spectral spikes over a large bandwidth of 100 nm (1.5–1.6 μm) within a compact footprint of 75 μm×1000 μm. Meanwhile, the in-plane tuning range can be large enough for arbitrary wavelengths to ensure the effectiveness of spectrum reconstruction. As a result, the proposed spectrometer can be easily transplanted to other operation bands by simply scaling the structural parameters. As a proof-of-concept, a mid-infrared spectrometer is further demonstrated with a dual-spike reconstruction resolution of 1.5 nm and a bandwidth of 300 nm (4–4.3 μm).

Adjustable focusing property of circular Airyprime beam through Fourier space modulation.

Airyprime beams are known for their powerful autofocusing property, which are further enhanced by the introduction of a circular structure-circular Airyprime beam (CAPB). We derive an asymptotic expression of the CAPB in Fourier space (FS) and verify its accuracy by the numerical Fourier transform (FT) method. Through FS modulation on it, adjustable control of autofocusing property of the FS-modulated CAPB can be achieved, whose lower and upper limits can reach 8.7% reduction and 2.6 times enhancement compared to the unmodulated one. The experimental results agree well with the numerical analyses. Our findings offer promising possibilities for efficient particle trapping and enhancing free-space optical communication capabilities.

Design and Implementation of High-Performance FPGA Accelerator for Non-Separable Discrete Fourier Transform Optimizing Real-Time Image and Video Processing

Design and Implementation of High-Performance FPGA Accelerator for Non-Separable Discrete Fourier Transform Optimizing Real-Time Image and Video Processing

Skin cancer detection through attention guided dual autoencoder approach with extreme learning machine

Skin cancer is a lethal disease, and its early detection plays a pivotal role in preventing its spread to other body organs and tissues. Artificial Intelligence (AI)-based automated methods can play a significant role in its early detection. This study presents an AI-based novel approach, termed 'DualAutoELM' for the effective identification of various types of skin cancers. The proposed method leverages a network of autoencoders, comprising two distinct autoencoders: the spatial autoencoder and the FFT (Fast Fourier Transform)-autoencoder. The spatial-autoencoder specializes in learning spatial features within input lesion images whereas the FFT-autoencoder learns to capture textural and distinguishing frequency patterns within transformed input skin lesion images through the reconstruction process. The use of attention modules at various levels within the encoder part of these autoencoders significantly improves their discriminative feature learning capabilities. An Extreme Learning Machine (ELM) with a single layer of feedforward is trained to classify skin malignancies using the characteristics that were recovered from the bottleneck layers of these autoencoders. The 'HAM10000' and 'ISIC-2017' are two publicly available datasets used to thoroughly assess the suggested approach. The experimental findings demonstrate the accuracy and robustness of the proposed technique, with AUC, precision, and accuracy values for the 'HAM10000' dataset being 0.98, 97.68% and 97.66%, and for the 'ISIC-2017' dataset being 0.95, 86.75% and 86.68%, respectively. This study highlights the possibility of the suggested approach for accurate detection of skin cancer.