OES diagnostics as a universal technique to control the Si etching structures profile in ICP

In this work, we demonstrate the high efficiency of optical emission spectroscopy to estimate the etching profile of silicon structures in SF$_{6}$/C$_{4}$F$_{8}$/O$_{2}$ plasma. The etching profile is evaluated as a ratio of the emission intensity of the oxygen line (778.1 nm) to the fluorine lines (685.8 nm and 703.9 nm). It was found that for the creation of directional structures with line sizes from 13 to 100 μm and aspect ratio from ≈ 0.15 to ≈ 5 the optimal intensities ratio is in the range of 2–6, and for structures from 400 to 4000 μm with aspect ratio from ≈ 0.03 to ≈ 0.37 it is in the range 1.5–2. Moreover, the influence of the process parameters on the etching rate of silicon, the etching rate of aluminum, the inclination angle of the profile wall of the etched window, the selectivity of silicon etching with respect to aluminum, and the influence on the overetching (Bowing effect) of the structure was investigated

Emission Monitoring Mobile Experiment (EMME): An overview and first results of the St. Petersburg megacity campaign 2019

Global climate change is one of the most important scientific, societal and economic contemporary challenges. Fundamental understanding of the major processes driving climate change is the key problem which is to be solved not only on a global but also on a regional scale. The accuracy of regional climate modelling depends on a number of factors. One of these factors is the adequate and comprehensive information on the anthropogenic impact which is highest in industrial regions and areas with dense population – modern megacities. Megacities are not only “heat islands”, but also significant sources of emissions of various substances into the atmosphere, including greenhouse and reactive gases. In 2019, the mobile experiment EMME (Emission Monitoring Mobile Experiment) was conducted within the St. Petersburg agglomeration (Russia) aiming to estimate the emission intensity of greenhouse (CO$_{2}$, CH$_{4}$) nd reactive (CO, NO$_{x}$) gases for St. Petersburg, which is the largest northern megacity. St. Petersburg State University (Russia), Karlsruhe Institute of Technology (Germany) and the University of Bremen (Germany) jointly ran this experiment. The core instruments of the campaign were two portable Bruker EM27/SUN Fourier transform infrared (FTIR) spectrometers which were used for ground-based remote sensing measurements of the total column amount of CO$_{2}$, CH$_{4}$ and CO at upwind and downwind locations on opposite sides of the city. The NO$_{2}$ tropospheric column amount was observed along a circular highway around the city by continuous mobile measurements of scattered solar visible radiation with an OceanOptics HR4000 spectrometer using the differential optical absorption spectroscopy (DOAS) technique. Simultaneously, air samples were collected in air bags for subsequent laboratory analysis. The air samples were taken at the locations of FTIR observations at the ground level and also at altitudes of about 100 m when air bags were lifted by a kite (in case of suitable landscape and favourable wind conditions). The entire campaign consisted of 11 mostly cloudless days of measurements in March–April 2019. Planning of measurements for each day included the determination of optimal location for FTIR spectrometers based on weather forecasts, combined with the numerical modelling of the pollution transport in the megacity area. The real-time corrections of the FTIR operation sites were performed depending on the actual evolution of the megacity NO$_{x}$ plume as detected by the mobile DOAS observations. The estimates of the St. Petersburg emission intensities for the considered greenhouse and reactive gases were obtained by coupling a box model and the results of the EMME observational campaign using the mass balance approach. The CO$_{2}$ emission flux for St. Petersburg as an area source was estimated to be 89 ± 28 ktkm$^{-2}$ yr $^{-2}$ , which is 2 times higher than the corresponding value in the EDGAR database. The experiment revealed the CH$_{4}$ emission flux of 135 ± 68 tkm $^{-2}$ yr $^{-1}$, which is about 1 order of magnitude greater than the value reported by the official inventories of St. Petersburg emissions (∼ 25 tkm$^{-2}$ yr $^{-1}$ or 2017). At the same time, for the urban territory of St. Petersburg, both the EMME experiment and the official inventories for 2017 give similar results for the CO anthropogenic flux (251 ± 104 tkm $^{-2}$ yr $^{-1}$ s. 410 tkm $^{-2}$ yr $^{-1}$) nd for the NO$_{x}$ anthropogenic flux (66 ± 28 tkm$^{-2}$ yr $^{-1}$ vs. 69 tkm $^{-2}$ yr $^{-1}$)

The Molecular and Cellular Strategies of Glioblastoma and Non-Small-Cell Lung Cancer Cells Conferring Radioresistance

Ionizing radiation (IR) has been shown to play a crucial role in the treatment of glioblastoma (GBM; grade IV) and non-small-cell lung cancer (NSCLC). Nevertheless, recent studies have indicated that radiotherapy can offer only palliation owing to the radioresistance of GBM and NSCLC. Therefore, delineating the major radioresistance mechanisms may provide novel therapeutic approaches to sensitize these diseases to IR and improve patient outcomes. This review provides insights into the molecular and cellular mechanisms underlying GBM and NSCLC radioresistance, where it sheds light on the role played by cancer stem cells (CSCs), as well as discusses comprehensively how the cellular dormancy/non-proliferating state and polyploidy impact on their survival and relapse post-IR exposure

Long-Term Cultured Human Glioblastoma Multiforme Cells Demonstrate Increased Radiosensitivity and Senescence-Associated Secretory Phenotype in Response to Irradiation

The overall effect of senescence on cancer progression and cancer cell resistance to X-ray radiation (IR) is still not fully understood and remains controversial. How to induce tumor cell senescence and which senescent cell characteristics will ensure the safest therapeutic strategy for cancer treatment are under extensive investigation. While the evidence for passage number-related effects on malignant primary cells or cell lines is compelling, much less is known about how the changes affect safety and Senescence-Associated Secretory Phenotype (SASP), both of which are needed for the senescence cell-based vaccine to be effective against cancer. The present study aimed to investigate the effects of repeated passaging on the biological (self-renewal capacity and radioresistance) and functional (senescence) characteristics of the different populations of short- and long-term passaging glioblastoma multiforme (GBM) cells responding to senescence-inducing DNA-damaging IR stress. For this purpose, we compared radiobiological effects of X-ray exposure on two isogenic human U87 cell lines: U87L, minimally cultured cells (3 years of continuous culturing after obtaining from the ATCC). U87L cells displayed IR dose-related changes in the signs of IR stress-induced premature senescence. These included an increase in the proportion of senescence-associated β-galactosidase (SA-β-Gal)-positive cells, and concomitant decrease in the proportion of Ki67-positive cells and metabolically active cells. However, reproductive survival of irradiated short-term cultured U87L cells was higher compared to long-term cultured U87H cells, as the clonogenic activity results demonstrated. In contrast, the irradiated long-term cultured U87H cells possessed dose-related increases in the proportion of multinucleated giant cancer cells (MGCCs), while demonstrating higher radiosensitivity (lower self-renewal) and a significantly reduced fraction of DNA-replicating cells compared to short-term cultured U87L cells. Conditioned culture medium from U87H cells induced a significant rise of SA-β-Gal staining in U87L cells in a paracrine manner suggesting inherent SASP. Our data suggested that low-dose irradiated long-term cultured GBM cells might be a safer candidate for a recently proposed senescence cell-based vaccine against cancer

Long-Term Cultured Human Glioblastoma Multiforme Cells Demonstrate Increased Radiosensitivity and Senescence-Associated Secretory Phenotype in Response to Irradiation

The overall effect of senescence on cancer progression and cancer cell resistance to X-ray radiation (IR) is still not fully understood and remains controversial. How to induce tumor cell senescence and which senescent cell characteristics will ensure the safest therapeutic strategy for cancer treatment are under extensive investigation. While the evidence for passage number-related effects on malignant primary cells or cell lines is compelling, much less is known about how the changes affect safety and Senescence-Associated Secretory Phenotype (SASP), both of which are needed for the senescence cell-based vaccine to be effective against cancer. The present study aimed to investigate the effects of repeated passaging on the biological (self-renewal capacity and radioresistance) and functional (senescence) characteristics of the different populations of short- and long-term passaging glioblastoma multiforme (GBM) cells responding to senescence-inducing DNA-damaging IR stress. For this purpose, we compared radiobiological effects of X-ray exposure on two isogenic human U87 cell lines: U87L, minimally cultured cells (<15 passages after obtaining from the ATCC) and U87H, long-term cultured cells (>3 years of continuous culturing after obtaining from the ATCC). U87L cells displayed IR dose-related changes in the signs of IR stress-induced premature senescence. These included an increase in the proportion of senescence-associated β-galactosidase (SA-β-Gal)-positive cells, and concomitant decrease in the proportion of Ki67-positive cells and metabolically active cells. However, reproductive survival of irradiated short-term cultured U87L cells was higher compared to long-term cultured U87H cells, as the clonogenic activity results demonstrated. In contrast, the irradiated long-term cultured U87H cells possessed dose-related increases in the proportion of multinucleated giant cancer cells (MGCCs), while demonstrating higher radiosensitivity (lower self-renewal) and a significantly reduced fraction of DNA-replicating cells compared to short-term cultured U87L cells. Conditioned culture medium from U87H cells induced a significant rise of SA-β-Gal staining in U87L cells in a paracrine manner suggesting inherent SASP. Our data suggested that low-dose irradiated long-term cultured GBM cells might be a safer candidate for a recently proposed senescence cell-based vaccine against cancer

INVESTIGATION OF MEASUREMENT PRECISION OF LATENT VARIABLES IN EDUCATION

The objective of the study is to investigate the measurement accuracy of latent variables depending on a number of dichotomous test items and variation range.Methods: Investigation is based on the simulation experiments.Results: The authors make recommendations for selecting a number of dichotomous test items and variation range depending on the required measurement precision of latent variables.Scientific novelty: The research demonstrates statistical correlation between the measurement precision of latent variables and a number of test items and variation range.Importance for practice: The research results can be used while developing the questionnaires and tests for measuring the latent variables

The Role of the SO 2 Radiative Effect in Sustaining the Volcanic Winter and Soothing the Toba Impact on Climate

Volcanic eruptions are an important climate driver. The impact of Pinatubo-sized eruptions has been observed and is well constrained. The magnitude and duration of volcanic winter effects after supereruptions such as Toba remain disputed due to disagreement between the strong cooling predicted by models and much milder climate perturbations according to the paleodata. Here we present a reevaluated climate impact of a Toba-sized supereruption based on up-to-date GISS ModelE simulations. In this study, we account for all known primary mechanisms that govern the evolution of the volcanic plume and their nonlinear interactions. The SO 2 radiative effects are evaluated for the first time in coupled climate simulations with the interactive atmospheric chemistry module. We found that SO 2 effects on photochemistry, dynamics, and radiative forcing are especially prominent. Due to strong absorption in ultraviolet, SO 2 feedback on photochemistry partially offsets the limiting effect associated with aerosol microphysical processes. SO 2 greenhouse warming soothes the radiative cooling exerted by sulfate aerosols. SO 2 absorption in the shortwave and longwave causes radiative heating and lofting of the volcanic plume, and boosts the efficiency of SO 2 impact on photochemistry. Our analysis shows that SO 2 lifetime and magnitude of effects scale up and increase with the amount of emitted material. For a Pinatubo-sized eruption, SO 2 feedbacks on chemistry and dynamics are relevant only during the initial stage of the volcanic plume evolution, while local SO 2 concentrations are high. For a Toba-sized eruption, SO 2 effects are as important as sulfate aerosols and produce a less extreme volcanic winter

Polyploid/Multinucleated Giant and Slow-Cycling Cancer Cell Enrichment in Response to X-ray Irradiation of Human Glioblastoma Multiforme Cells Differing in Radioresistance and TP53/PTEN Status

Radioresistance compromises the efficacy of radiotherapy for glioblastoma multiforme (GBM), the most devastating and common brain tumor. The present study investigated the relationship between radiation tolerance and formation of polyploid/multinucleated giant (PGCC/MGCC) and quiescent/senescent slow-cycling cancer cells in human U-87, LN-229, and U-251 cell lines differing in TP53/PTEN status and radioresistance. We found significant enrichment in MGCC populations of U-87 and LN-229 cell lines, and generation of numerous small mononuclear (called Raju cells, or RJ cells) U-87-derived cells that eventually form cell colonies, in a process termed neosis, in response to X-ray irradiation (IR) at single acute therapeutic doses of 2–6 Gy. For the first time, single-cell high-content imaging and analysis of Ki-67- and EdU-coupled fluorescence demonstrated that the IR exposure dose-dependently augments two distinct GBM cell populations. Bifurcation of Ki-67 staining suggests fast-cycling and slow-cycling populations with a normal-sized nuclear area, and with an enlarged nuclear area, including one resembling the size of PGCC/MGCCs, that likely underlie the highest radioresistance and propensity for repopulation of U-87 cells. Proliferative activity and anchorage-independent survival of GBM cell lines seem to be related to neosis, low level of apoptosis, fraction of prematurely stress-induced senescent MGCCs, and the expression of p63 and p73, members of p53 family transcription factors, but not to the mutant p53. Collectively, our data support the importance of the TP53wt/PTENmut genotype for the maintenance of cycling radioresistant U-87 cells to produce a significant amount of senescent MGCCs as an IR stress-induced adaptation response to therapeutic irradiation doses

Synthesis of CF3-Containing 1,2,3,4-Tetrahydroisoquinoline-3-Phosphonates via Regioselective Ruthenium-Catalyzed Co-cyclotrimerization of 1,7-Aza­diynes

International audienceAn efficient access to novel trifluoromethyl-substituted phosphonate analogues of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (TIC) derivatives based on regioselective ruthenium-­catalyzed co-cyclotrimerization of functionalized 1,7-diynes with various alkynes has been developed using RuClCp*cod and pre­ferably Grubbs second-generation catalysts