Mechanical Properties of 1.5 wt.% TiB2-added Hypoeutectic Al-Mg- Si Alloys Processed by Equal Channel Angular Pressing

In order to improve the mechanical properties and to optimize grain refinement of Al-Mg-Si alloy, ECAP processing with an addition of hard particle TiB₂ is applied in this work. Mechanical property and microstructural evolution of Al-0.3Mg-7Si+1.5 wt.% TiB₂ specimen were investigated by using hardness-testing, optical micrograph observation and electron-backscattering diffraction (EBSD). ECAP processing was done through B_A route for 4 passes at room temperature. Hardness test results show that the ECAP process doubled the hardness of the specimen compared to annealed specimen, and from EBSD/OIM analysis, the ECAP processing refined grains from an average grain size of 35 μm to 0.79 μm and led to producing grains having high misorientation angle (≥15).     

Imaging of Oral SCC Cells by Raman Micro-Spectroscopy Technique

We used Raman micro-spectroscopy technique to analyze the molecular changes associated with oral squamous cell carcinoma (SCC) cells in the form of frozen tissue. Previously, Raman micro-spectroscopy technique on human tissue was mainly based on spectral analysis, but we worked on imaging of molecular structure. In this study, we evaluated the distribution of four components at the cell level (about 10 μm) to describe the changes in protein and molecular structures of protein belonging to malignant tissue. We analyzed ten oral SCC samples of five patients without special pretreatments of the use of formaldehyde. We obtained cell level images of the oral SCC cells at various components (peak at 935 cm⁻¹: proline and valine, 1004 cm⁻¹: phenylalanine, 1223 cm⁻¹: nucleic acids, and 1650 cm⁻¹: amide I). These mapping images of SCC cells showed the distribution of nucleic acids in the nuclear areas; meanwhile, proline and valine, phenylalanine, and amide I were detected in the cytoplasm areas of the SCC cells. Furthermore, the peak of amide I in the cancer area shifts to the higher wavenumber side, which indicates the α-helix component may decrease in its relative amounts of protein in the β-sheet or random coil conformation. Imaging of SCC cells with Raman micro-spectroscopy technique indicated that such a new observation of cancer cells is useful for analyzing the detailed distribution of various molecular conformation within SCC cells.     

Solubility and Thermodynamic Data of Febuxostat in Various Mono Solvents at Different Temperatures

This study examines the solubility and thermodynamics of febuxostat (FBX) in a variety of mono solvents, including “water, methanol (MeOH), ethanol (EtOH), isopropanol (IPA), 1-butanol (1-BuOH), 2-butanol (2-BuOH), ethylene glycol (EG), propylene glycol (PG), polyethylene glycol-400 (PEG-400), ethyl acetate (EA), Transcutol-HP (THP), and dimethyl sulfoxide (DMSO)” at 298.2–318.2 K and 101.1 kPa. The solubility of FBX was determined using a shake flask method and correlated with “van’t Hoff, Buchowski-Ksiazczak λh, and Apelblat models”. The overall error values for van’t Hoff, Buchowski-Ksiazczak λh, and Apelblat models was recorded to be 1.60, 2.86, and 1.14%, respectively. The maximum mole fraction solubility of FBX was 3.06 × 10⁻² in PEG-400 at 318.2 K, however the least one was 1.97 × 10⁻⁷ in water at 298.2 K. The FBX solubility increased with temperature and the order followed in different mono solvents was PEG-400 (3.06 × 10⁻²) > THP (1.70 × 10⁻²) > 2-BuOH (1.38 × 10⁻²) > 1-BuOH (1.37 × 10⁻²) > IPA (1.10 × 10⁻²) > EtOH (8.37 × 10⁻³) > EA (8.31 × 10⁻³) > DMSO (7.35 × 10⁻³) > MeOH (3.26 × 10⁻³) > PG (1.88 × 10⁻³) > EG (1.31 × 10⁻³) > water (1.14 × 10⁻⁶) at 318.2 K. Compared to the other combinations of FBX and mono solvents, FBX-PEG-400 had the strongest solute-solvent interactions. The apparent thermodynamic analysis revealed that FBX dissolution was “endothermic and entropy-driven” in all mono solvents investigated. Based on these findings, PEG-400 appears to be the optimal co-solvent for FBX solubility.     

Free Radical Isomerizations in Acetylene Bromoboration Reaction

The experimentally motivated question of the acetylene bromoboration mechanism was addressed in order to suggest possible radical isomerization pathways for the syn-adduct. Addition–elimination mechanisms starting with a bromine radical attack at the “bromine end” or the “boron end” of the C=C bond were considered. Dispersion-corrected DFT and MP2 methods with the SMD solvation model were employed using three all-electron bases as well as the ECP28MWB ansatz. The rate-determining, elimination step had a higher activation energy (12 kcal mol⁻¹) in case of the “bromine end” attack due to intermediate stabilization at both the MP2 and DFT levels. In case of the “boron end” attack, two modes of C–C bond rotation were followed and striking differences in MP2 vs. DFT potential energy surfaces were observed. Employing MP2, addition was followed by either a 180° rotation through an eclipsed conformation of vicinal bromine atoms or by an opposite rotation avoiding that conformation, with 5 kcal mol⁻¹ of elimination activation energy. Within B3LYP, the addition and rotation proceeded simultaneously, with a 9 (7) kcal mol⁻¹ barrier for rotation involving (avoiding) eclipsed conformation of vicinal bromines. For weakly bound complexes, ZPE corrections with MP2 revealed significant artifacts when diffuse bases were included, which must be considered in the Gibbs free energy profile interpretation.     

Fast Li-Ion Conduction in Spinel-Structured Solids

Spinel-structured solids were studied to understand if fast Li⁺ ion conduction can be achieved with Li occupying multiple crystallographic sites of the structure to form a “Li-stuffed” spinel, and if the concept is applicable to prepare a high mixed electronic-ionic conductive, electrochemically active solid solution of the Li⁺ stuffed spinel with spinel-structured Li-ion battery electrodes. This could enable a single-phase fully solid electrode eliminating multi-phase interface incompatibility and impedance commonly observed in multi-phase solid electrolyte–cathode composites. Materials of composition Li_1.25M(III)_0.25TiO₄, M(III) = Cr or Al were prepared through solid-state methods. The room-temperature bulk Li⁺-ion conductivity is 1.63 × 10⁻⁴ S cm⁻¹ for the composition Li_1.25Cr_0.25Ti_1.5O₄. Addition of Li₃BO₃ (LBO) increases ionic and electronic conductivity reaching a bulk Li⁺ ion conductivity averaging 6.8 × 10⁻⁴ S cm⁻¹, a total Li-ion conductivity averaging 4.2 × 10⁻⁴ S cm⁻¹, and electronic conductivity averaging 3.8 × 10⁻⁴ S cm⁻¹ for the composition Li_1.25Cr_0.25Ti_1.5O₄ with 1 wt. % LBO. An electrochemically active solid solution of Li_1.25Cr_0.25Mn_1.5O₄ and LiNi_0.5Mn_1.5O₄ was prepared. This work proves that Li-stuffed spinels can achieve fast Li-ion conduction and that the concept is potentially useful to enable a single-phase fully solid electrode without interphase impedance.     

H_2S环境中UNS J91540不锈钢的电化学行为对SCC的影响

应用慢应变速率拉伸试验和电化学方法研究了湿硫化氢溶液中UNS J91450不锈钢的电化学行为对应力腐蚀开裂的影响.结果表明,本实验条件下UNS J91540不锈钢具有较高的SCC敏感性,并随着溶液pH的降低而明显增大.该不锈钢的电化学行为对它的腐蚀开裂(SCC)敏感性具有重要影响.开路电位下该不锈钢的SCC行为同时受氢脆作用和裂纹尖端阳极溶解作用的影响.在pH较低的介质中析氢电流较高而裂纹尖端阳极溶解作用略低,而在pH较高的介质中析氢电流较低而裂纹尖端的阳极溶解作用相对增强.氢脆作用对UNS J91540不锈钢SCC敏感性影响更显著.     

Delocalization tunable by ligand substitution in [L2Al]n− complexes highlights a mechanism for strong electronic coupling

Ligand-based mixed valent (MV) complexes of Al(iii) incorporating electron donating (ED) and electron withdrawing (EW) substituents on bis(imino)pyridine ligands (I₂P) have been prepared. The MV states containing EW groups are both assigned as Class II/III, and those with ED functional groups are Class III and Class II/III in the (I₂P⁻)(I₂P²⁻)Al and [(I₂P²⁻)(I₂P³⁻)Al]²⁻ charge states, respectively. No abrupt changes in delocalization are observed with ED and EW groups and from this we infer that ligand and metal valence p-orbitals are well-matched in energy and the absence of LMCT and MLCT bands supports the delocalized electronic structures. The MV ligand charge states (I₂P⁻)(I₂P²⁻)Al and [(I₂P²⁻)(I₂P³⁻)Al]²⁻ show intervalence charge transfer (IVCT) transitions in the regions 6850–7740 and 7410–9780 cm⁻¹, respectively. Alkali metal cations in solution had no effect on the IVCT bands of [(I₂P²⁻)(I₂P³⁻)Al]²⁻ complexes containing –PhNMe₂ or –PhF₅ substituents. Minor localization of charge in [(I₂P²⁻)(I₂P³⁻)Al]²⁻ was observed when –PhOMe substituents are included.

Organo-aluminum mixed-valent complexes combine properties of both organic and transition element mixed-valent compounds. This supports delocalized electronic structures that are structurally and electronically tunable.     

In Silico Studies of Some Isoflavonoids as Potential Candidates against COVID-19 Targeting Human ACE2 (hACE2) and Viral Main Protease (Mpro)

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the “COVID-19” disease that has been declared by WHO as a global emergency. The pandemic, which emerged in China and widespread all over the world, has no specific treatment till now. The reported antiviral activities of isoflavonoids encouraged us to find out its in silico anti-SARS-CoV-2 activity. In this work, molecular docking studies were carried out to investigate the interaction of fifty-nine isoflavonoids against hACE2 and viral M^pro. Several other in silico studies including physicochemical properties, ADMET and toxicity have been preceded. The results revealed that the examined isoflavonoids bound perfectly the hACE-2 with free binding energies ranging from −24.02 to −39.33 kcal mol⁻¹, compared to the co-crystallized ligand (−21.39 kcal mol^–1). Furthermore, such compounds bound the M^pro with unique binding modes showing free binding energies ranging from −32.19 to −50.79 kcal mol^–1, comparing to the co-crystallized ligand (binding energy = −62.84 kcal mol^–1). Compounds 33 and 56 showed the most acceptable affinities against hACE2. Compounds 30 and 53 showed the best docking results against M^pro. In silico ADMET studies suggest that most compounds possess drug-likeness properties.     

Developing high strain rate superplasticity inAlMgScZr alloys using equal-channel angular pressing

The processing of metallic alloys through the procedure of equal-channel angular pressing (ECAP) provides an opportunity for achieving superplastic ductilities at very high strain rates. This paper reports experimental data from an investigation of a series of AlMgScZr alloys processed by ECAP. The results show the occurrence of high tensile ductilities at testing strain rates above 10⁻² s⁻¹.     

Anti-Electrostatic Pi-Hole Bonding: How Covalency Conquers Coulombics

Intermolecular bonding attraction at π-bonded centers is often described as “electrostatically driven” and given quasi-classical rationalization in terms of a “pi hole” depletion region in the electrostatic potential. However, we demonstrate here that such bonding attraction also occurs between closed-shell ions of like charge, thereby yielding locally stable complexes that sharply violate classical electrostatic expectations. Standard DFT and MP2 computational methods are employed to investigate complexation of simple pi-bonded diatomic anions (BO⁻, CN⁻) with simple atomic anions (H⁻, F⁻) or with one another. Such “anti-electrostatic” anion–anion attractions are shown to lead to robust metastable binding wells (ranging up to 20–30 kcal/mol at DFT level, or still deeper at dynamically correlated MP2 level) that are shielded by broad predissociation barriers (ranging up to 1.5 Å width) from long-range ionic dissociation. Like-charge attraction at pi-centers thereby provides additional evidence for the dominance of 3-center/4-electron (3c/4e) n_D-π*_AX interactions that are fully analogous to the n_D-σ*_AH interactions of H-bonding. Using standard keyword options of natural bond orbital (NBO) analysis, we demonstrate that both n-σ* (sigma hole) and n-π* (pi hole) interactions represent simple variants of the essential resonance-type donor-acceptor (Bürgi–Dunitz-type) attraction that apparently underlies all intermolecular association phenomena of chemical interest. We further demonstrate that “deletion” of such π*-based donor-acceptor interaction obliterates the characteristic Bürgi–Dunitz signatures of pi-hole interactions, thereby establishing the unique cause/effect relationship to short-range covalency (“charge transfer”) rather than envisioned Coulombic properties of unperturbed monomers.     

A generator of peroxynitrite activatable with red light

The generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) as “unconventional” therapeutics with precise spatiotemporal control by using light stimuli may open entirely new horizons for innovative therapeutic modalities. Among ROS and RNS, peroxynitrite (ONOO⁻) plays a dominant role in chemistry and biology in view of its potent oxidizing power and cytotoxic action. We have designed and synthesized a molecular hybrid based on benzophenothiazine as a red light-harvesting antenna joined to an N-nitroso appendage through a flexible spacer. Single photon red light excitation of this molecular construct triggers the release of nitric oxide (˙NO) and simultaneously produces superoxide anions (O₂˙⁻). The diffusion-controlled reaction between these two radical species generates ONOO⁻, as confirmed by the use of fluorescein-boronate as a highly selective chemical probe. Besides, the red fluorescence of the hybrid allows its tracking in different types of cancer cells where it is well-tolerated in the dark but induces remarkable cell mortality under irradiation with red light in a very low concentration range, with very low light doses (ca. 1 J cm⁻²). This ONOO⁻ generator activatable by highly biocompatible and tissue penetrating single photon red light can open up intriguing prospects in biomedical research, where precise and spatiotemporally controlled concentrations of ONOO⁻ are required.

Excitation of a molecular hybrid with highly biocompatible red light generates cytotoxic peroxynitrite, produces red fluorescence useful for cell tracking and induces remarkable cancer cell death at very low concentrations and very low light doses.     

A stable and high-energy aqueous aluminum based battery

Aqueous aluminum ion batteries (AAIBs) have received growing attention because of their low cost, safe operation, eco-friendliness, and high theoretical capacity. However, one of the biggest challenges for AAIBs is the poor reversibility due to the presence of an oxide layer and the accompanying hydrogen evolution reaction. Herein, we develop a strongly hydrolyzed/polymerized aluminum–iron hybrid electrolyte to improve the electrochemical behavior of AAIBs. On the one hand, the designed electrolyte enables aluminum ion intercalation/deintercalation on the cathode while stable deposition/stripping of aluminium occurs on the anode. On the other hand, the electrolyte contributes to the electrochemical energy storage through an iron redox reaction. These two reactions are parallel and coupled through an Fe–Al alloy on the anode, thus enhancing the reversibility and energy density of AAIBs. As a result, this hybrid-ion battery delivers a specific volumetric capacity of 35 A h L⁻¹ at the current density of 1.0 mA cm⁻², and remarkable stability with a capacity retention of 90% over 500 cycles. Furthermore, the hybrid-ion battery achieves a high energy density of approximately 42 W h L⁻¹ with an average operating voltage of 1.1 V. This green electrolyte for high-energy AAIBs holds promises for large-scale energy storage applications.

A hybrid-ion aqueous aluminium ion battery (HIAAIB) with nickel hexacyanoferrate as the cathode, Al as the anode and a polymerized Al–Fe hybrid electrolyte is reported. During discharge, an Fe–Al alloy forms at the anode, improving performance by relieving corrosion.     

Electrochemical noise generated during the stress corrosion cracking of sensitized alloy 690

Electrochemical noise in current has been used to monitor the stress corrosion cracking (SCC) susceptibility of alloy 690 sensitized at 700 °C during 48 h in sodium thiosulfate at 90 °C. At 48 h of aging, the specimen failed by SCC and the corrosion current pulses had high intensity and low frequency, and were associated with the nucleation and propagation of stress corrosion cracks during slow strain rate tests. When the alloy was immune to SCC, the observed corrosion current pulses had a much higher frequency and lower intensity, indicating either uniform corrosion or passivation. The type of transients observed do not indicate the mechanism responsible for the observed embrittlement, but only the cracking initiation or propagation process.     

Highly Effective Proton-Conduction Matrix-Mixed Membrane Derived from an -SO3H Functionalized Polyamide

Developing a low-cost and effective proton-conductive electrolyte to meet the requirements of the large-scale manufacturing of proton exchange membrane (PEM) fuel cells is of great significance in progressing towards the upcoming “hydrogen economy” society. Herein, utilizing the one-pot acylation polymeric combination of acyl chloride and amine precursors, a polyamide with in-built -SO₃H moieties (PA-PhSO₃H) was facilely synthesized. Characterization shows that it possesses a porous feature and a high stability at the practical operating conditions of PEM fuel cells. Investigations of electrochemical impedance spectroscopy (EIS) measurements revealed that the fabricated PA-PhSO₃H displays a proton conductivity of up to 8.85 × 10⁻² S·cm⁻¹ at 353 K under 98% relative humidity (RH), which is more than two orders of magnitude higher than that of its -SO₃H-free analogue, PA-Ph (6.30 × 10⁻⁴ S·cm⁻¹), under the same conditions. Therefore, matrix-mixed membranes were fabricated by mixing with polyacrylonitrile (PAN) in different ratios, and the EIS analyses revealed that its proton conductivity can reach up to 4.90 × 10⁻² S·cm⁻¹ at 353 K and a 98% relative humidity (RH) when the weight ratio of PA-PhSO₃H:PAN is 3:1 (labeled as PA-PhSO₃H-PAN (3:1)), the value of which is even comparable with those of commercial-available electrolytes being used in PEM fuel cells. Additionally, continuous tests showed that PA-PhSO₃H-PAN (3:1) possesses a long-life reusability. This work demonstrates, using the simple acylation reaction with the sulfonated module as precursor, that low-cost and highly effective proton-conductive electrolytes for PEM fuel cells can be facilely achieved.     

Redox Speciation of Vanadium in Estuarine Waters Using Improved Methodology Based on Anion Exchange Chromatography Coupled to HR ICP-MS System

An improved methodology was developed for V redox speciation in estuarine waters using a hyphenated technique consisting of ion chromatograph (IC) with an anion exchange column and a high-resolution inductively coupled plasma mass spectrometer (HR ICP-MS). This approach enables the direct determination of V(V), whereas reduced species (mainly V(IV)) are calculated by subtracting V(V) concentrations from the measured total V concentration. Based on the “on-column” V(V) chelation mechanism by EDTA, with the eluent composed of 40 mmol L⁻¹ ammonium bicarbonate, 40 mmol L⁻¹ ammonium sulphate, 8 mmol L⁻¹ ethylenediaminetetraacetic acid and 3% acetonitrile, the method was successfully used for analyses of V redox speciation in samples taken in the vertical salinity gradient of the highly stratified Krka River estuary. Due to the matrix effects causing different sensitivities, a standard addition method was used for V(V) quantification purposes. The limit of detection (LOD) was also found to be matrix related: 101.68 ng L⁻¹ in the seawater and 30.56 µg L⁻¹ in the freshwater. Performed stability tests showed that V redox speciation is preserved at least 7 days in un-treated samples, possibly due to the stabilization of V-reduced species with natural organic matter (NOM). The dominant V form in the analysed samples was V(V) with the reduced V(IV) accounting for up to 26% of the total dissolved pool. The concentration of V(IV) was found to correlate negatively with the oxygen concentration. Significant removal of dissolved V was detected in oxygen depleted zones possibly related to the particle scavenging.     

Monitoring of Pollutants Content in Bottled and Tap Drinking Water in Italy

The concentration levels of thirteen organic pollutants and selected heavy metals were investigated in 40 plastics bottled and tap water samples. Some of the selected contaminants have an ascertained or suspected endocrine disrupting activity, such as Bisphenol A (BPA) and its analogs, and Bis 2-ethylhexyl phthalate (DEHP), which are used by industries as plasticizers. The most frequently detected pollutants were Bisphenol AF (BPAF) (detection frequency (DF) = 67.5%, mean 387.21 ng L⁻¹), DEHP (DF = 62.5%, mean 46.19 µg L⁻¹) and BPA (DF = 60.0%, mean 458.57 ng L⁻¹), with higher concentration levels found in tap waters. Furthermore, a possible level of exposure to thirteen pollutants via drinking water intake was calculated. Our findings show that, even though the occurrence of contaminants and heavy metals in drinking waters does not pose an immediate, acute health risk for the population, their levels should be constantly monitored and “hard-wired” into everyday practice. Indeed, the health impact to the continuous and simultaneous intake of a huge variety of xenobiotics from various sources by humans is complex and still not fully understood.     

Use of a Hydrophobic Azo Dye for the Centrifuge-Less Cloud Point Extraction–Spectrophotometric Determination of Cobalt

The hydrophobic azo dye 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR, H₂L) was studied as part of a system for the centrifuge-less cloud point extraction (CL-CPE) and spectrophotometric determination of traces of cobalt. The extracted 1:2 (Co:HTAR) complex, [Co^III(HL⁻)(L²⁻)]⁰, shows an absorption maximum at 553 nm and contains HTAR in two different acid–base forms. Optimum conditions for its formation and CL-CPE were found as follows: 1 × 10⁻⁵ mol L⁻¹ of HTAR, 1.64% of Triton X-114, pH of 7.8, incubation time of 20 min at ca. 50 °C, and cooling time of 30 min at ca. −20 °C. The linear range, limit of detection, and apparent molar absorptivity coefficient were 5.4–189 ng mL⁻¹, 1.64 ng mL⁻¹, and 2.63 × 10⁵ L mol⁻¹ cm⁻¹, respectively. The developed procedure does not use any organic solvents and can be described as simple, cheap, sensitive, convenient, and environmentally friendly. It was successfully applied to the analysis of artificial mixtures and real samples, such as steel, dental alloy, rainwater, ampoules of vitamin B₁₂, and saline solution for intravenous infusion.     

Pinkment: a synthetic platform for the development of fluorescent probes for diagnostic and theranostic applications

Reaction-based fluorescent-probes have proven successful for the visualisation of biological species in various cellular processes. Unfortunately, in order to tailor the design of a fluorescent probe to a specific application (i.e. organelle targeting, material and theranostic applications) often requires extensive synthetic efforts and the synthetic screening of a range of fluorophores to match the required synthetic needs. In this work, we have identified Pinkment-OH as a unique “plug-and-play” synthetic platform that can be used to develop a range of ONOO⁻ responsive fluorescent probes for a variety of applications. These include theranostic-based applications and potential material-based/bioconjugation applications. The as prepared probes displayed an excellent sensitivity and selectivity for ONOO⁻ over other ROS. In vitro studies using HeLa cells and RAW 264.7 macrophages demonstrated their ability to detect exogenously and endogenously produced ONOO⁻. Evaluation in an LPS-induced inflammation mouse model illustrated the ability to monitor ONOO⁻ production in acute inflammation. Lastly, theranostic-based probes enabled the simultaneous evaluation of indomethacin-based therapeutic effects combined with the visualisation of an inflammation biomarker in RAW 264.7 cells.

Pinkment, a resorufin based ONOO⁻ selective and sensitive ‘plug and play’ fluorescence-based platform for in vitro and in vivo use, enables facile functionalisation for various imaging and theranostic applications.     

Micro-Raman Characterization of Structural Features of High-k Stack Layer of SOI Nanowire Chip,Designed to Detect Circular RNA Associated with the Development of Glioma

The application of micro-Raman spectroscopy was used for characterization of structural features of the high-k stack (h-k) layer of “silicon-on-insulator” (SOI) nanowire (NW) chip (h-k-SOI-NW chip), including Al₂O₃ and HfO₂ in various combinations after heat treatment from 425 to 1000 °C. After that, the NW structures h-k-SOI-NW chip was created using gas plasma etching optical lithography. The stability of the signals from the monocrine phase of HfO₂ was shown. Significant differences were found in the elastic stresses of the silicon layers for very thick (>200 nm) Al₂O₃ layers. In the UV spectra of SOI layers of a silicon substrate with HfO₂, shoulders in the Raman spectrum were observed at 480–490 cm⁻¹ of single-phonon scattering. The h-k-SOI-NW chip created in this way has been used for the detection of DNA-oligonucleotide sequences (oDNA), that became a synthetic analog of circular RNA–circ-SHKBP1 associated with the development of glioma at a concentration of 1.1 × 10⁻¹⁶ M. The possibility of using such h-k-SOI NW chips for the detection of circ-SHKBP1 in blood plasma of patients diagnosed with neoplasm of uncertain nature of the brain and central nervous system was shown.