Alferov Federal State Budgetary Institution of Higher Education and Science Saint Petersburg National Research Academic University of the Russian Academy of Sciences (abbreviated SPbAU RAS, also referred to as the Academic University or Alferov University) was founded in 1997 originally as the Research and Education Center of the Ioffe Institute to integrate science and education in the field of physics and information technologies. It has the distinction of being the only university in the Russian Academy of Sciences (RAS), which is composed primarily of national research institutes. Accordingly, the word "Academic" in the university's name stems from the Academy of Sciences, the organization that unites numerous national research institutes in Russia. The St. Petersburg Academic University was founded by Zhores Alferov, director of the Ioffe Institute, vice-president of the RAS Academician and Nobel prize laureate, who served as its rector until his death on March 1, 2019.
This review addresses the challenges of obtaining high-quality quantitative data in the optical imaging of membrane voltage and calcium dynamics. The paper provides a comprehensive overview and systematization of recent studies that analyze factors limiting signal fidelity and propose strategies to enhance data quality. The primary sources of signal degradation in biological optical imaging, with an emphasis on membrane voltage and calcium imaging, are systematically explored across four major indicator classes: voltage-sensitive dyes (VSDs), genetically encoded voltage indicators (GEVIs), calcium-sensitive dyes (CSDs), and genetically encoded calcium indicators (GECIs). Common mechanisms that compromise data quality are classified into three main categories: fundamental photon shot noise, device-related errors, and sample-related measurement errors. For each class of limitation, its physical or biological origin and characteristic manifestations are described, which are followed by an analysis of available mitigation strategies, including hardware optimization, choice of sensors, sample preparation and experimental design, post-processing and computational correction methods.
Modern nanophotonics allows one to engineer the optical modes and localize light at the nanoscale. In this work, we visualize the local density of optical states (LDOS) distribution of the single femtosecond-laser-printed gold nanobump with ultrahigh spatial resolution. Scanning tunneling microscope-induced light emission allows us to achieve LDOS mapping with a spatial resolution of around 15 nm for single nanobumps and their agglomerates with gold plasmonic nanoantennas, having a relatively small diameter. Our experimental and theoretical results show that a plasmonic nanoantenna can be integrated into an optical system to enhance its radiation outcoupling efficiency, while leaving its modal structure mainly unaffected. A deep understanding of the optical modes in nanostructures opens up possibilities for creating new types of optoelectronic components based on inelastically tunneling electrons, providing light emission.
We report an all-liquid, vacuum-free approach for fabricating hybrid metal-semiconductor platforms for surface-enhanced Raman scattering (SERS). Silicon wafers were textured into upright (Pyr-Si) and inverted pyramids (IPyr-Si) by anisotropic alkaline etching and Cu-assisted chemical etching, respectively, both yielding broadband antireflective morphologies. Subsequent laser-induced deposition (LID) enabled surfactant-free decoration of these 3D morphologies with Au, Ag, and bimetallic AuAg nanoparticles directly in solution. Scanning electron microscopy (SEM) images and energy dispersive X-ray spectroscopy (EDX) mapping versus exposure time reveal distinct Ag/Au growth modes consistent with plasmon-assisted and substrate-assisted pathways. SERS performance was benchmarked with rhodamine 6G (R6G) down to 10(-12) M, delivering an enhancement factor of similar to 2.9 x 10(9) for Ag/IPyr-Si. Practical sensing of ketoprofen and plasmon-driven catalytic dimerization of paminothiophenol (PATP) were also demonstrated. Compared with conventional vacuum-based techniques, this approach minimizes air exposure, lowers costs, and delivers conformal nanoparticle coverage on complex silicon morphologies, providing a scalable route to reproducible, high-performance SERS sensors and related optoelectronic interfaces.
A self-healing LED architecture that integrates three main components as blue-emitting InGaN/GaN core–shell microwires, self-healing polydimethylsiloxane, and single-walled carbon nanotube electrodes positioned on the silicone matrix was developed.
Abstract Three-dimensional (3D) spheroid models are increasingly used in cancer research because they reproduce several features of solid tumors that are not represented in conventional two-dimensional (2D) monolayer cultures. In the present study, we developed and optimized spheroid culture conditions for a panel of breast, ovarian, and gastric cancer cell lines grown on low-attachment plates. Spheroid formation, morphology, and growth behavior were assessed during culture, and the resulting models were used for the comparative testing of reference anticancer agents. The established assay framework was further applied to newly developed cyclin-dependent kinase 7 (CDK7) inhibitor candidates from our in-house compound library. Anticancer activity was evaluated by using AlamarBlue or PrestoBlue viability assays after prolonged drug exposure. Reproducible spheroid formation conditions were identified for the studied cell lines, although notable cell line-specific differences in morphology, growth behavior, and assay duration were observed. Comparative drug testing revealed differences in apparent sensitivity between 2D and 3D cultures depending on the cell line and compound. Several tested CDK7 inhibitor candidates reduced viability in the spheroid models, with iCDK7_1 showing the strongest activity across the evaluated panel. Overall, the study describes and applies a cell line-adapted 3D spheroid assay workflow for comparative evaluation of antiproliferative effects in breast, ovarian, and gastric cancer models.
