Browse Articles

Application research of convolutional neural network and its optimization in lightning electric field waveform recognition

Highly selective aptasensor for optical detection of whole cell gastrointestinal pathogen <i>Shigella dysenteriae</i> at label-free liquid crystal–aqueous interface

This paper describes a label-free liquid crystal (LC)-based biosensor for a rapid and straightforward detection of whole cell Shigella dysenteriae at aqueous interfaces using a bacteria-specific aptamer. The stimuli-receptive properties of LCs induce a change in the orientational ordering of molecules at the LC–aqueous interface. This interfacial phenomenon has been utilized to record target binding interactions of the biosensor. The homeotropic LC alignment at the glass–LC and the aqueous–LC interfaces was obtained using the aligning agent dimethyloctadecyl [3-(trimethoxysilyl)propyl] ammonium chloride and the self-assembling property of the cationic surfactant cetyltrimethylammonium bromide, respectively. The introduction of the negatively charged Shigella aptamer causes the homeotropic molecules to morph to a planar/tilted ordering. Upon adding a small quantity of Shigella cells in liquid media, the aptamer–bacterium interaction causes a redistribution of the surfactant at the LC–aqueous interface, restoring the homeotropic alignment. This results in a bright-to-dark optical change observed under a polarizing optical microscope, thus implying the presence of the microbes. This reported aptasensor demonstrates high specificity, with the limit of detection being 30 CFU/ml within a linear range of 1–105 CFU/ml. To test the utility of this system, the sensor was also tested with close taxonomic relatives S. dysenteriae as well as real samples from the food chain. This proposed LC-based sensor offers several advantages over conventional detection techniques for a quick and convenient way for the detection of whole cell targets.

Therapeutic potential of brentuximab vedotin in breast cancer and lymphoma via targeted apoptosis and gene regulation

Abstract This study was designed to assess the effect of brentuximab vedotin on several breast cancer cell lines in terms of promoting apoptosis and managing cancer progression. Additionally, the study investigated the potential of repurposing this drug for new therapeutic reasons, beyond its original indications. The study evaluates the cytotoxic effects of Brentuximab vedotin across five cell lines: normal human skin fibroblasts (HSF), three breast cancer cell lines (MCF-7, MDA-MB-231, and T-47D), and histiocytic lymphoma (U-937). Brentuximab treatment was administered at four time points (0, 24, 48, and 72 h), with cell viability assessed at each interval. HSF cells, serving as controls, exhibited minimal viability loss (above 70%), indicating limited toxicity in normal fibroblasts. In contrast, MCF-7 and MDA-MB-231 cells demonstrated time-dependent reductions in viability, with a pronounced decline by 72 h, suggesting Brentuximab’s efficacy in both ER-positive and triple-negative breast cancer. T-47D cells also showed decreased viability, though at a slower rate. U-937 cells exhibited the most substantial reduction, highlighting Brentuximab’s potent activity against hematologic malignancies. Wound healing assays further revealed that Brentuximab significantly impaired the migration and healing capacity of cancer cells compared to untreated controls. Additionally, cell cycle analysis indicated G2/M phase arrest in cancer cells, particularly in MCF-7 and MDA-MB-231, while HSF cells remained largely unaffected. Apoptosis detection confirmed Brentuximab-induced cell death, with significant increases in late apoptosis in cancer lines, especially by 72 h. Gene expression analysis revealed upregulation of pro-apoptotic genes (BAX, Caspase 3, and Caspase 9) in cancer cells, alongside a decrease in anti-apoptotic BCL-2 expression. These findings suggest Brentuximab’s selective cytotoxicity against cancer cells and its potential as an effective therapeutic agent, particularly in breast cancer and histiocytic lymphoma.

Significant negative differential resistance and current limiting effects of cyclo[14]carbon-based molecular devices with graphene electrodes

Through tip-induced dehalogenation and retro-Bergman ring-opening reaction of fully chlorinated anthanthrene (C14Cl10), the cyclo[14]carbon (C14) was prepared. Owing to its distinctive physical properties, C14 holds the potential to serve as the core unit of functional electronic devices. Herein, the density functional theory combined with the non-equilibrium Green's function technique was used to investigate the electronic transport properties of molecular devices composed of C14 molecules and graphene electrodes, systematically. We find that molecular devices composed of polyynic and cumulenic structures of C14 exhibit a significant negative differential resistance effect and effective current limiting ability at low bias voltages, respectively. Moreover, by calculating and analyzing the transmission function and projected density of states under different biases, a reasonable explanation of those effects is provided.

From ideation to real context of use of a digital solution to promote physical and cognitive training for older adults

Realization and simulation of silicon-on-sapphire mid-infrared one-dimensional photonic crystal cavities

The mid-infrared (MIR) waveband is significant for chemical and biological sensing since it covers several atmospheric windows and molecular fingerprint regions. On-chip photonic integrated one-dimensional (1D) microcavities have great potential for high-performance mid-IR sensing because of their high sensitivity and compact structure. However, high-performance 1D microcavities based on the promising silicon-on-sapphire (SoS) MIR platform have not yet been designed or realized. Based on the photonic band structure induced by 1D photonic crystals (PhC), a high-performance Bragg reflector, an inward apodized Bragg grating, and a free spectral range (FSR)-free PhC microcavity integrated system operating in the MIR waveband were developed on the SoS platform. By carefully designing the period and penetration depth of the corrugation in the Bragg reflector, a stopband of 45 nm and an extinction ratio of −12 dB were achieved. The inward apodized Bragg grating was optimized by adjusting the apodization depth and the number of periods, resulting in a quality factor of 1043 at a wavelength of 3088.4 nm. Furthermore, introducing a Fabry–Pérot (F-P) cavity between two Bragg reflectors (with side-coupled light) and precisely tuning the stopband of the Bragg reflector and the FSR of the F-P cavity enabled the realization of an FSR-free PhC microcavity. This microcavity exhibited a single deep resonance dip with subnanometer bandwidth across a record-wide operational waveband from 3025 to 3200 nm, achieving a quality factor of approximately 5090. The MIR 1D PhC microcavities on the SoS platform hold great promise for high-performance gas detection and molecular sensing in future applications.

Age-related trends in trabecular bone scores and bone mineral density in Chinese men with type 2 diabetes mellitus: a cross-sectional study

Non-contact electroacoustic tomography with optical interferometer for electroporation therapy monitoring

Electroacoustic imaging is an imaging modality used to detect electric field energy distribution during electroporation, offering valuable guidance for clinical procedures, particularly in deep tissues. Traditionally, single-element piezoelectric transducers or arrays have been employed for this purpose. However, these piezoelectric sensors are sensitive to electromagnetic interference and require physical contact with the sample through a coupling medium, raising concerns for both clinical and preclinical applications. To overcome these limitations, a multi-channel random quadrature ultrasonics system has been developed, enabling non-contact detection of electroacoustic signals. In this study, we demonstrated that this non-contact technique effectively detects electroacoustic signals, identifies electroporation regions, and reconstructs electric energy distribution, offering a promising approach for monitoring electroporation therapy.

Spectroscopic aspects of underwater digital holography of plankton

Tailoring dynamics of thermally activated delayed fluorescence molecules embedded in cavity by forming coupling-induced hybrid states

Light–matter coupling-induced hybrid states provide the potential to tune the emission dynamics of molecular chromophores having multilevel systems. We demonstrate the alteration of delayed fluorescence dynamics by hybrid states formation through the interaction of light with a thermally activated delayed fluorescence molecule embedded in a conventional Fabry–Pérot cavity. The proximity of cavity resonance with the excited state absorption is modified by manipulating the incident angles (with sample) instead of varying the active layer thickness. The coupling-induced hybrid states are observed by angle-dependent emission spectroscopy and lifetime measurements. The variation in average emission lifetime with respect to incident angle is over 10 μs and is accompanied by significant changes in the full width at half maxima (factor of three). The control of emission via a barrier-free route or reverse intersystem crossing transition is demonstrated from these measurements. These findings suggest the possibility of tailoring intermediate states for lasing, where exciton density inversion can enhance spontaneous emission.

Clinical spectrum of adult-onset leukoencephalopathy with axonal spheroids and pigmented glia in individuals of Korean ancestry

Probing interfacial states in β-Ga2O3/SiO2 TFTs for high-response broad-band photodetection

Mechanically exfoliated β-Ga2O3 flakes preserve bulk material's single crystallinity for easy integration but suffer from interfacial defects that greatly influence device performance. In this paper, we report a quantitative characterization of interfacial states in phrase β-Ga2O3/SiO2 thin-film transistors and then propose their beneficial application in achieving high-response broad-band photodetection. Photo-excited charge collection spectroscopy technique was employed to probe the interfacial states, revealing a substantial density (∼4 × 1012 cm−2 eV−1) of deep-level states ranging from 2.5 to 3.7 eV below the conduction band. Intriguingly, a photoresponsivity as high as 2 × 104 A/W was achieved via utilizing these interfacial states, along with the tunable broad-band response ranging from 335 to 496 nm. This research enhances both the well-industrialized silicon devices and the emerging β-Ga2O3 technologies. Furthermore, it introduces a profound concept: defects, once seen as flaws, can be assets when their characteristics are thoroughly understood.

Pipeline for development of acylated peptide based CGRP receptor antagonist with extended half-life for migraine treatment

Bi24Al2O39:Mn5<b>+</b>-phosphor-based single-emission ratiometric thermometer

Both excitation and single emission of Bi24Al2O39:Mn5+ phosphors are possible in the near-infrared (NIR) region, which can be simultaneously detected. Monitoring the excitation radiation allows us to prevent its fluctuations from affecting the luminescence. Single emission is a technique that involves the luminescence intensity ratio, so fluctuations in the intensity of the excitation radiation do not affect the result. This technique has the advantage of involving conventional methods and is not affected by optical dispersion, so it provides reliable results suitable for practical applications. Using this method, we investigate the temperature-sensing characteristics of Bi24Al2O39:0.5%Mn5+ phosphors from 300 to 380 K. Under 970 nm excitation, the maximal relative sensitivity is 3.54% K−1 in the physiological temperature range (300–330 K) and reaches 3.98% K−1 at 351 K. The excellent temperature sensing and NIR excitation and emission suggest that this NIR thermometer can be used for biological applications.

Exploring target selectivity in designing and identifying PI3Kα inhibitors for triple negative breast cancer with fragment-based and bioisosteric replacement approach

Abstract Triple-negative breast cancer (TNBC) is one of the most fatal malignancies in the world, accounting for 42% of all deaths due to metastasis. The significant development is hindered by the multi-drug resistance and poor patient compliance. PIK3CA gene mutation is one of the important causes of TNBC, which causes dysregulation of the cell cycle and cell proliferation. PI3Kα selective inhibition can decrease the TNBC by a significant level with minimal off-target effects. Novel compounds with high selectivity towards PI3Kα are crucial for treating TNBC. After extensive literature analysis, it was observed that fragment-based drug discovery, combined with structure-based virtual screening and bioisosteric replacement strategy, could provide a novel way for hit-to-lead optimization. The present study focussed on the fragment-based direct linking of 11269 moieties of the ChemDiv fragment library, - to generate novel moieties and further screened them using molecular docking, MMGBSA, and target selectivity analysis. Further, the top 2 moieties – Djh1 and Djh2 were selected after MMGBSA analysis and target selectivity prediction towards kinase. Further induced fit docking (IFD) analysis, DFT analysis, and MD simulation were employed to establish that – Djh1 and Djh2 could act as potential hit molecules for selective inhibition of PI3Kα. Further bioisosteric replacement, docking analysis, and target selectivity analysis were performed with the bioisosteres. The top two bioisosteres of Djh1 – Compound 10, Compound 06 represented excellent efficacy and selectivity towards PI3Kα in the treatment of TNBC after analysis of ADMET analysis. Further, in vitro and in vivo analysis might prove the effectiveness of the hit compounds.

Strain-induced thermal switches with a high switching ratio in monolayer boron sulfide

Manipulating the thermal conductivity of materials and achieving a high thermal switching ratio is very important in fields such as thermal management and energy conversion. In this study, by utilizing first-principles calculations and semi-classical Boltzmann transport theory, we find the lattice thermal conductivity (κl) of monolayer boron sulfide (BS) can reach values as low as 0.11 Wm−1 K−1 at room temperature, significantly lower than that of well-known two-dimensional materials with low thermal conductivity such as SnSe. This phenomenon is mainly caused by the strong lattice anharmonicity, which is primarily induced by the lone electron pairs. The effect of biaxial strain on κl is further investigated. It is found that a small strain of 2% can lead to a two orders of magnitude increase in κl. Moreover, this property remains stable within the strain range of 2%–7%, making it easier to achieve experimentally. The variation of κl with strain is mainly determined by the change in phonon lifetime, which is governed by the competition between the reduction of anti-bonding valence band states and the enhanced coupling between soft optical and acoustic phonons. Our results indicate that monolayer BS is a promising candidate material for thermal switches and energy conversion devices.

Evaluation of osseointegration of plasma treated polyaryletherketone maxillofacial implants

Abstract Osseointegration is a crucial property of biomaterials used for bone defect repair. While titanium is the gold standard in craniofacial surgeries, various polymeric biomaterials are being explored as alternatives. However, polymeric materials can be bioinert, hindering integration with surrounding tissues. In this investigation, plasma ion immersion implantation (PIII)-treated polyether ether ketone (PEEK) and polyether ketone (PEK) implants were assessed in a sheep maxilla and mandible model. Defects were filled with PIII-treated PEEK and PEK implants, produced through fused filament fabrication (FFF) and selective laser sintering (SLS), respectively. Positive controls were grade 23 titanium implants via selective laser melting, while untreated PEEK implants served as negative controls. Surface analyses using scanning electron microscopy and atomic force microscopy revealed favorable properties. Osseointegration was qualitatively and quantitatively assessed at 8-, 10-, and 12-weeks post-implantation, showing significantly improved outcomes for both PIII-treated PEEK and PEK implants compared to untreated controls. The study suggests PIII treatment enhances FFF-printed PEEK’s osseointegration, and PIII-treated SLS-printed PEK achieves comparable osseointegration to 3D printed titanium. These findings underscore surface modification strategies’ potential for polymeric biomaterials, offering insights into developing alternative implant materials for craniofacial surgeries, with enhanced biocompatibility and osseointegration capabilities for improved clinical outcomes.

Improving the thermoelectric properties of septuple atomic-layer SnBi2Se4 by regulating the carrier concentration through Nb doping

Layered semiconductor materials have garnered significant attention in the thermoelectric field due to their excellent electrical property and intrinsically low lattice thermal conductivity. The septuple atomic-layered ternary compound SnBi2Se4 is reported as a promising thermoelectric material in both bulk and single-layer structures based on theoretical calculations, though experimental investigation remains unexplored. In this work, the melting and hot-press sintering methods were adopted to synthesize the septuple atomic-layered SnBi2Se4. Its unique layered crystal structure contributed to significant anisotropic transport properties and reduced thermal conductivity. However, its thermoelectric performance is constrained by a low carrier concentration that limits electrical conductivity. To solve this issue, the high-valent transition metal Nb was doped at Bi site to provide additional electrons. This doping resulted in a noticeable improvement in the performance of septuple atomic-layered SnBi2Se4 due to increased electrical conductivity and decreased thermal conductivity. Finally, a peak ZT ∼ 0.17 was obtained for SnBi1.97Nb0.03Se4 at 723 K, suggesting the effectiveness of Nb doping in enhancing the performance. These results indicate that septuple atomic-layered SnBi2Se4 is a highly promising thermoelectric material, though further performance improvements are needed.

Targeted co-delivery nanosystem based on methotrexate, curcumin, and PAMAM dendrimer for improvement of the therapeutic efficacy in cervical cancer

Lubrication for macroscopic friction pairs with single-layer graphene coating

With its strong mechanical properties, graphene has shown potential in applications for reducing friction and wear, but the underlying mechanisms for its macroscopic lubrication remain relatively unexplored. Here, we systematically study the lubrication effect of chemical vapor deposition graphene coated on the surfaces of macroscopic friction pairs made of different materials. Our findings reveal an apparent lubrication by single-layer graphene coating, as well as correlation between the COF and the brittleness of the substrate. Through a comprehensive characterization using Raman spectroscopy, we propose a protective mechanism by which graphene can effectively dissipate the resulting shear stress generated during friction and delay the wear generation until the graphene layer fails and the bare material surface starts to rub directly, which is confirmed by finite element analysis simulation. We believe our results can provide important support for the practical application of graphene coatings in lubrication for macroscopic friction pairs in industrial equipment.