New hybrid materials on the basis of magnetite and magnetite-gold nanoparticles for biomedical application

During last decades magnetite nanoparticles (NPs) attract a deep interest of scientists due to their potential application in therapy and diagnostics. However, magnetite nanoparticles are toxic and non-stable in physiological conditions. To solve these problems, we decided to create two types of hybrid systems based on magnetite and gold which is inert and biocompatible: gold as a shell material (first type) and gold as separate NPs interfacially bond to magnetite NPs (second type). An additional advantage of gold is the possibility of its functionalization with a variety of sulphur-containing ligands; that is very important for drug delivery and creating of tissue-specific MRI contrast agents. The synthesis of the first type hybrid nanoparticles was carried out as follows: magnetite nanoparticles with an average diameter of 9±2 nm were obtained by co-precipitation of iron (II, III) chlorides then they were covered with gold shell by iterative reduction of hydrogen tetrachloroaurate with hydroxylamine hydrochloride. According to the TEM, ICP MS and EDX data, final nanoparticles had an average diameter of 31±4 nm and contained iron even after hydrochloric acid treatment. However, iron signals (K-line, 7,1 keV) were not localized so we can’t speak about one single magnetic core. Described nanoparticles covered with mercapto-PEG acid were non-toxic for human prostate cancer PC-3/ LNCaP cell lines (more than 90% survived cells as compared to control) and had high R2-relaxivity rates (\u3e190 mМ-1s-1) that exceed the transverse relaxation rate of commercial MRI-contrasting agents. These nanoparticles were also used for chymotrypsin enzyme immobilization. The effect of alternating magnetic field on catalytic properties of chymotrypsin immobilized on magnetite nanoparticles, notably the slowdown of catalyzed reaction at the level of 35-40 % was found. The most probable reason for the observed effect is the change of active centers topology on the enzyme surface as a result of its deformation under applied forces. The synthesis of the second type hybrid nanoparticles also involved two steps. Firstly, spherical gold nanoparticles with an average diameter of 9±2 nm were synthesized by the reduction of hydrogen tetrachloroaurate with oleylamine; secondly, they were used as seeds during magnetite synthesis by thermal decomposition of iron pentacarbonyl in octadecene. As a result, so-called dumbbell-like structures were obtained where magnetite (cubes with 25±6 nm diagonal) and gold nanoparticles were connected together pairwise. By HRTEM method (first time for this type of structure) an epitaxial growth of magnetite nanoparticles on gold surface with co-orientation of (111) planes was discovered. These nanoparticles were transferred into water by means of block-copolymer Pluronic F127 then loaded with anti-cancer drug doxorubicin and also PSMA-vector specific for LNCaP cell line. Obtained nanoparticles were found to have moderate toxicity for human prostate cancer cells and got into the intracellular space after 45 minutes of incubation (according to fluorescence microscopy data). These materials are also perspective from MRI point of view (R2-relaxivity rates \u3e70 mМ-1s-1). Thereby, in this work magnetite-gold hybrid nanoparticles, which have a strong potential for biomedical application, particularly in targeted drug delivery and magnetic resonance imaging, were synthesized and characterized. That paves the way to the development of new medicine types – theranostics. The authors knowledge financial support from Ministry of Education and Science of the Russian Federation (14.607.21.0132, RFMEFI60715X0132). This work was also supported by Grant of Ministry of Education and Science of the Russian Federation К1-2014-022, Grant of Russian Scientific Foundation 14-13-00731 and MSU development program 5.13

Terapascal static pressure generation with ultrahigh yield strength nanodiamond

Studies of materials’ properties at high and ultrahigh pressures lead to discoveries of unique physical and chemical phenomena and a deeper understanding of matter. In high-pressure research, an achievable static pressure limit is imposed by the strength of available strong materials and design of high-pressure devices. Using a high-pressure and high-temperature technique, we synthesized optically transparent microballs of bulk nanocrystalline diamond, which were found to have an exceptional yield strength (~460 GPa at a confining pressure of ~70 GPa) due to the unique microstructure of bulk nanocrystalline diamond. We used the nanodiamond balls in a double-stage diamond anvil cell high-pressure device that allowed us to generate static pressures beyond 1 TPa, as demonstrated by synchrotron x-ray diffraction. Outstanding mechanical properties (strain-dependent elasticity, very high hardness, and unprecedented yield strength) make the nanodiamond balls a unique device for ultrahigh static pressure generation. Structurally isotropic, homogeneous, and made of a low-Z material, they are promising in the field of x-ray optical applications

Stress plays provoking role in hypertension-related stroke: Injuries of blood-brain barrier function

Chronic hypertension itself does not cause stroke but significantly decreases the resistant to stroke induced by stress due to exhausting of adaptive capacity of cerebral endothelium and decrease resistance of blood-brain barrier to stress

The stress and vascular catastrophes in newborn rats: mechanisms preceding and accompanying the brain hemorrhages

In this study, we analyzed the time-depended scenario of stress response cascade preceding and accompanying brain hemorrhages in newborn rats using an interdisciplinary approach based on: a morphological analysis of brain tissues, coherent-domain optical technologies for visualization of the cerebral blood flow, monitoring of the cerebral oxygenation and the deformability of red blood cells (RBCs). Using a model of stress-induced brain hemorrhages (sound stress, 120 dB, 370 Hz), we studied changes in neonatal brain 2, 4, 6, 8 h after stress (the pre-hemorrhage, latent period) and 24 h after stress (the post-hemorrhage period). We found that latent period of brain hemorrhages is accompanied by gradual pathological changes in systemic, metabolic, and cellular levels of stress. The incidence of brain hemorrhages is characterized by a progression of these changes and the irreversible cell death in the brain areas involved in higher mental functions. These processes are realized via a time-depended reduction of cerebral venous blood flow and oxygenation that was accompanied by an increase in RBCs deformability. The significant depletion of the molecular layer of the prefrontal cortex and the pyramidal neurons, which are crucial for associative learning and attention, is developed as a consequence of homeostasis imbalance. Thus, stress-induced processes preceding and accompanying brain hemorrhages in neonatal period contribute to serious injuries of the brain blood circulation, cerebral metabolic activity and structural elements of cognitive function. These results are an informative platform for further studies of mechanisms underlying stress-induced brain hemorrhages during the first days of life that will improve the future generation's health

Terapascal static pressure generation with ultrahigh yield strength nanodiamond

Studies of materials’ properties at high and ultrahigh pressures lead to discoveries of unique physical and chemical phenomena and a deeper understanding of matter. In high-pressure research, an achievable static pressure limit is imposed by the strength of available strong materials and design of high-pressure devices. Using a high-pressure and high-temperature technique, we synthesized optically transparent microballs of bulk nanocrystalline diamond, which were found to have an exceptional yield strength (~460 GPa at a confining pressure of ~70 GPa) due to the unique microstructure of bulk nanocrystalline diamond. We used the nanodiamond balls in a double-stage diamond anvil cell high-pressure device that allowed us to generate static pressures beyond 1 TPa, as demonstrated by synchrotron x-ray diffraction. Outstanding mechanical properties (strain-dependent elasticity, very high hardness, and unprecedented yield strength) make the nanodiamond balls a unique device for ultrahigh static pressure generation. Structurally isotropic, homogeneous, and made of a low-Z material, they are promising in the field of x-ray optical applications

Habrobates vejisovi Kelejnikova 1977

Habrobates vejisovi Kelejnikova, 1977 Material examined Paratypes TURKMENISTAN • 2 ♀♀; “Репетек, 23–24.IV.1974, КуЗнецов” [Repetek]; “ 22-IV-74, гол. барх.” [bare barchans dunes]; “Paratypus, ♀, Habrobates vejisovi Kelejn 19.II.1977 ”; 23–24 Apr. 1974; N.Ya. Kuznetsov leg.; ZIN • 1♀; same collection data as for preceding; HNHM. Additional material TURKMENISTAN • 1 ♂; Karakum, Repetek; 27 Jan. 1957; N.G. Skopin leg.; ZIN • 7 ♂♂, 6 ♀♀; same collection data as for preceding; 6 Mar. 1958; G.S. Medvedev leg.; ZIN • 1 ♂, 1 ♀; same collection data as for preceding; 12 Apr. 1972; Begov leg.; ZIN • 2 ♂♂, 3 ♀♀; same collection data as for preceding; 16 Apr. 1980; B.A. Korotyaev leg.; ZIN. Distribution Turkmenistan (Karakum Desert, east).Published as part of Chigray, Svetlana N., Nabozhenko, Maxim V., Chigray, Ivan A. & Abakumov, Evgeny V., 2022, A revision of the Palaearctic Pimeliini (Coleoptera: Tenebrionidae): a comparative analysis and systematic position of Eastern European and Asian taxa with dorso-lateral eyes, pp. 1-71 in European Journal of Taxonomy 809 on page 23, DOI: 10.5852/ejt.2022.809.1719, http://zenodo.org/record/641942

Glioma Stem Cells: Novel Data Obtained by Single-Cell Sequencing

Glioma is the most common type of primary CNS tumor, composed of cells that resemble normal glial cells. Recent genetic studies have provided insight into the inter-tumoral heterogeneity of gliomas, resulting in the updated 2021 WHO classification of gliomas. Thorough understanding of inter-tumoral heterogeneity has already improved the prognosis and treatment outcomes of some types of gliomas. Currently, the challenge for researchers is to study the intratumoral cell heterogeneity of newly defined glioma subtypes. Cancer stem cells (CSCs) present in gliomas and many other tumors are an example of intratumoral heterogeneity of great importance. In this review, we discuss the modern concept of glioma stem cells and recent single-cell sequencing-driven progress in the research of intratumoral glioma cell heterogeneity. The particular emphasis was placed on the recently revealed variations of the cell composition of the subtypes of the adult-type diffuse gliomas, including astrocytoma, oligodendroglioma and glioblastoma. The novel data explain the inconsistencies in earlier glioma stem cell research and also provide insight into the development of more effective targeted therapy and the cell-based immunotherapy of gliomas. Separate sections are devoted to the description of single-cell sequencing approach and its role in the development of cell-based immunotherapies for glioma

Platyope proctoleuca subsp. proctoleuca proctoleuca Fischer von Waldheim 1820

Platyope proctoleuca proctoleuca Fischer von Waldheim, 1820 Fig. 6A Material examined KAZAKHSTAN • 1♂; Zaysan valley, Aygy-kum; 10 Jun. 1968; N.G. Skopin leg.; ZIN. RUSSIA • 1 ♂, 4 ♀♀; “Sibir.”; ZIN • 2 ♂♂, 3 ♀♀; “Sibir. occ.”; ZIN. Distribution Russia (Altai: Kulunda Steppe). Kazakhstan (Zaysan Depression, Irtysh River and Black Irtysh River valleys). This species was listed only for Zaysan Depression in Kazakhstan in the Palaearctic Catalogue (Iwan et al. 2020), but Medvedev (1990) recorded P. proctoleuca proctoleuca also for Russian Altai and the Irtysh valley in Kazakhstan.Published as part of Chigray, Svetlana N., Nabozhenko, Maxim V., Chigray, Ivan A. & Abakumov, Evgeny V., 2022, A revision of the Palaearctic Pimeliini (Coleoptera: Tenebrionidae): a comparative analysis and systematic position of Eastern European and Asian taxa with dorso-lateral eyes, pp. 1-71 in European Journal of Taxonomy 809 on pages 45-46, DOI: 10.5852/ejt.2022.809.1719, http://zenodo.org/record/641942

Platyope grumi Chigray & Nabozhenko & Chigray & Abakumov 2022, comb. nov.

Platyope grumi (Semenov, 1893) comb. nov. Figs 5D–H, 13A–D, 21, 23G, 28E Material examined Lectotype designated here CHINA • 1 ♂; bronze circle; “Кульджа 1879. A. Регель” [Kul’dzha; now Yining]; “ Homopsis Grumi m. AS. II.92.”; “104726”; 1879; A. Regel’ leg.; ZIN. Paralectotypes CHINA • 19 ♂♂, 14 ♀♀; same collection data as for lectotype; ZIN. Additional material CHINA • 1 spec.; “Джинхо” [Jinghe]; 13 April 1889; G.E. Grum-Grzhimaylo leg.; ZIN • 1 spec. “ Dzhungarische Wüste Z.T. ” [Dzungarian Desert]; 16 April 1926; S.G. Beick leg.; ZIN. Distribution China (Xinjiang: Yining).Published as part of Chigray, Svetlana N., Nabozhenko, Maxim V., Chigray, Ivan A. & Abakumov, Evgeny V., 2022, A revision of the Palaearctic Pimeliini (Coleoptera: Tenebrionidae): a comparative analysis and systematic position of Eastern European and Asian taxa with dorso-lateral eyes, pp. 1-71 in European Journal of Taxonomy 809 on page 49, DOI: 10.5852/ejt.2022.809.1719, http://zenodo.org/record/641942

Earophanta collaris

Earophanta collaris (Fischer von Waldheim, 1844) Fig. 7A Material examined KAZAKHSTAN • 2 ♂♂, 1 ♀; Kapchagay, Kokbastau; 27 Jun. 1952; P. Ler leg.; ZIN • 4 ♂♂, 2 ♀♀; near Ili; 22 Jun. 1950; N.G. Skopin leg.; ZIN • same collection data as for preceding; 6 Jul. 1954; ZIN • 1 ♂, 2 ♀♀; Ili River; 8 Jun. 1952; P. Ler leg.; ZIN • 1 ♀; Kapchagay; 15 Apr. 1962; G. Nikolaev leg.; ZIN. CHINA • 45 ♂♂, 70 ♀♀; Yining [Qulja]; 1879; A. Regel’ leg.; ZIN. Distribution South Eastern Kazakhstan, China (Xijiang).Published as part of Chigray, Svetlana N., Nabozhenko, Maxim V., Chigray, Ivan A. & Abakumov, Evgeny V., 2022, A revision of the Palaearctic Pimeliini (Coleoptera: Tenebrionidae): a comparative analysis and systematic position of Eastern European and Asian taxa with dorso-lateral eyes, pp. 1-71 in European Journal of Taxonomy 809 on pages 52-53, DOI: 10.5852/ejt.2022.809.1719, http://zenodo.org/record/641942