Конфликт культур в повести Н. В. Гоголя «Вий»

В повести Н.В. Гоголя «Вий» рассмотрена утрата нравственных начал жизни и цельности сознания личности, обусловленная конфликтом культур, который проявляется на разных уровнях. В результате столкновения язычества и православия произошла деформация обеих традиционных моделей мира. Это проявляется и в именах бурсаков, и в поведении семинаристов и казаков на хуторе сотника, и в миропонимании и веросознании главного героя повести. Все это делает гибель Хомы Брута неизбежной

A New Stereocontrolled Total Synthesis of the Mast Cell Inhibitory Alkaloid, (+)-Monanchorin, via the Wittig Reaction of a Stabilized Ylide with a Cyclic Guanidine Hemiaminal

An asymmetric total synthesis of the mast cell inhibitor (+)-monanchorin is reported in which a Sharpless AD on <b>11</b> and a cyclic sulfate ring opening with an azide feature as key steps. After further manipulation, a novel guanidine-controlled ester reduction provided the guanidine-hemiaminal <b>25</b> which underwent Wittig olefination to give <b>27</b>. Hydrogenation and a second guanidine-controlled reduction of the ester in <b>28</b>, to obtain aldehyde <b>29</b>, then set up a trifluoroacetic acid mediated cyclization to give (+)-monanchorin TFA salt

Improving Tribological Properties of Multialkylated Cyclopentanes under Simulated Space Environment: Two Feasible Approaches

Space mechanisms require multialkylated cyclopentanes (MACs) more lubricious, more reliable, more durable, and better adaptive to harsh space environments. In this study, two kinds of additives were added into MACs for improving the tribological properties under simulated space environments: (a) solid nanoparticles (tungsten disulfide (WS₂), tungsten trioxide (WO₃), lanthanum oxide (La₂O₃), and lanthanum trifluoride (LaF₃)) for steel/steel contacts; (b) liquid additives like zinc dialkyldithiophosphate (ZDDP) and molybdenum dialkyldithiocarbamate (MoDTC) for steel/steel and steel/diamond-like carbon (DLC) contacts. The results show that, under harsh simulated space environments, addition of the solid nanoparticles into MACs allows the wear to be reduced by up to one order magnitude, while liquid additives simultaneously reduce friction and wear by 80% and 93%, respectively. Friction mechanisms were proposed according to surface/interface analysis techniques, such as X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). The role of solid nanoparticles in reducing friction and wear mainly depends on their surface enhancement effect, and the liquid additives are attributed to the formation of tribochemical reaction film derived from ZDDP and MoDTC on the sliding surfaces

Synergistic Effect of Hybrid Carbon Nanotube–Graphene Oxide as Nanoadditive Enhancing the Frictional Properties of Ionic Liquids in High Vacuum

A remarkable synergetic effect between the graphene oxide (GO) layers and multiwalled carbon nanotubes (MWCNTs) in improving friction and wear on sliding diamond-like carbon (DLC) surfaces under high vacuum condition (10^–5 Pa) and low or high applied load is demonstrated. In tests with sliding DLC surfaces, ionic liquid solution that contains small amounts of GO and MWCNTs exhibited the lowest specific friction coefficient and wear rate under all of the sliding conditions. Optical microscope images of the wear scar of a steel ball showed that GO/MWCNT composites exhibited higher antiwear capability than individual MWCNTs and GO did. Transmission electron microscopy images of nanoadditives after friction testing showed that MWCNTs support the GO layers like pillars and prevent assembly between the GO layers. Their synergistic effect considerably enhances IL-GO/MWCNT composites

Formation of a Mimetic Biomembrane from the Hydrophobic Protein Zein and Phospholipids: Structure and Application

α-Zein, a storage protein in corn endosperm, could be purified easily and in large amounts. In this study, α-zein was incorporated into phospholipid–cholesterol (PC–Chol) liposomes. The maximal amount of α-zein incorporated in the liposome was 0.05% (mol/mol) and the PC:Zein molar ratio was near 2400. At this level of zein insertion, the phase transition temperature of the lipid bilayer was little affected, but the leakage of doxorubicin (DOX) from the PC–Chol liposome became obviously slower when α-zein was added at a higher temperature than the phase transition temperature. Cryogenic transmission electron micrographs of the PC–Chol–Zein liposome showed that adjacent membranes in multilamellar vesicles were often aligned at a regular interval of about 7 nm. Data from synchrotron small-angle X-ray scattering of the PC–Chol–Zein liposome indicated the formation of the multilamellar structure with an intermembrane interval of 7.2 nm, whereas no homogeneous membrane alignment was observed in the absence of zein. The present observation can be well explained by supposing that α-zein takes on such an elongated conformation that it penetrates through two adjacent membrane layers. This feature seems to be compatible with a recently proposed superhelical structural model of α-zein. Meanwhile, experiments with the fluorescent-labeled α-zein showed that the PC–Chol–Zein liposome could be uptaken by an intact cell and localized in some specialized area (possibly endosomes) within the cell instead of being diffusely distributed in the cell. Thus, the PC–Chol–Zein liposome seems to act as an interesting biomembrane model and may be applicable as a drug delivery system

Fabrication of Stable and Well-Dispersed Polyaniline–Polypyrrolidone Nanocomposite for Effective Photothermal Therapy

Well-dispersed polyaniline (PANi) nanoparticles were successfully synthesized by simple oxidative polymerization of aniline in a two-phase system in the presence of poly­(vinylpyrrolidone) (PVP) as a polymer shell agent, and citric acid was used as a doping acid instead of inorganic acids due to its better biocompatibility. TEM showed that the nanocomposites of PANi and PVP (PANi@PVP) assembled into core–shell like nanostructures uniformly. MTT results indicated that the PANi@PVP nanoparticles supported the survival of cells; IC50 could reach about 2.5 mg/mL, much higher than the IC50 value reported for PANi nanoparticles without PVP. Furthermore, in the presence of PVP, only exceeding PANi (>1.5 mg/mL) resulted in a comparable production of intracellular reactive oxygen species (ROS), the induction of apoptosis in PC-12 cells, and a weaker DNA fragmentation. TEM of PC-12 cell sections displayed that the cell morphological changes associated with the apoptosis were induced when exposed to a very high dose of PANi@PVP (3 mg/mL). The well-dispersed PANi@PVP combined with NIR irradiation achieved excellent photothermal conversion performance, which could kill cancer cell BEL-7402 in vitro effectively. Reflecting this well-dispersed property, the tumors in cancer bearing KM mice disappeared thoroughly after a single subcutaneous injection of PANi@PVP nanoparticles and subsequent NIR laser irradiation

Effects of silicon on <i>Oryza sativa</i> L. seedling roots under simulated acid rain stress

<div><p>Silicon (Si) has an important function in reducing the damage of environmental stress on plants. Acid rain is a serious abiotic stress factor, and Si can alleviate the stress induced by acid rain on plants. Based on these assumptions, we investigated the effects of silicon on the growth, root phenotype, mineral element contents, hydrogen peroxide (H₂O₂) and antioxidative enzymes of rice (<i>Oryza sativa</i> L.) seedling roots under simulated acid rain (SAR) stress. The results showed that the combined or single effects of Si and/or SAR on rice roots depend on the concentration of Si and the pH of the SAR. The combined or single effects of a low or moderate concentration of Si (1.0 or 2.0 mM) and light SAR (pH 4.0) enhanced the growth of rice roots, and the combined effects were stronger than those of the single treatment. A high concentration of Si (4.0 mM) or severe SAR (pH 2.0) exerted deleterious effects. The incorporation of Si (1.0, 2.0 or 4.0 mM) into SAR with pH 3.0 or 2.0 promoted the rice root growth, decreased the H₂O₂ content, increased the Si concentration and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities, maintained the balance of mineral element (K, Ca, Mg, Fe, Zn, and Cu) concentrations in the roots of rice seedlings compared with SAR alone. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with a low or high concentration of Si (1.0 or 4.0 mM). The observed effects were due to disruptions in the absorption and utilization of mineral nutrients and impacts on the activity of antioxidant enzymes in roots, and this conclusion suggests that the degree of rice root damage caused by acid rain might be attributed to not only acid rain but also the level of Si in the soil.</p></div

Atomic-Scale Probing of the Dynamics of Sodium Transport and Intercalation-Induced Phase Transformations in MoS₂

For alkali-metal-ion batteries, probing the dynamic processes of ion transport in electrodes is critical to gain insights into understanding how the electrode functions and thus how we can improve it. Here, by using <i>in situ</i> high-resolution transmission electron microscopy, we probe the dynamics of Na transport in MoS₂ nanostructures in real-time and compare the intercalation kinetics with previous lithium insertion. We find that Na intercalation follows the two-phase reaction mechanism, that is, trigonal prismatic 2H-MoS₂ → octahedral 1T-NaMoS₂, and the phase boundary is ∼2 nm thick. The velocity of the phase boundary at <10 nm/s is 1 order smaller than that of lithium diffusion, suggesting sluggish kinetics for sodium intercalation. The newly formed 1T-NaMoS₂ contains a high density of defects and series superstructure domains with typical sizes of ∼3–5 nm. Our results provide valuable insights into finding suitable Na electrode materials and understanding the properties of transition metal dichalcogenide MoS₂

Images of rice seedling roots under different treatments.

<p>(A-D) no Si; (E-H) 1 mM Si; (I-L) 2 mM Si; (M-P) 4 mM Si; (A, E, I, M) no acid soil; (B, F, J, N) SAR at pH 4; (C, G, K, O) SAR at pH 3; and (D, H, L, P) SAR at pH 2.</p

α‑Glucosidase Inhibitors from the Marine-Derived Fungus <i>Aspergillus flavipes</i> HN4-13

Three new butenolide derivatives, flavipesolides A–C (<b>1</b>–<b>3</b>), along with 13 known compounds (<b>4</b>–<b>13</b>, aspulvinone Q, monochlorosulochrin, and dihydrogeodin), were isolated from the marine-derived <i>Aspergillus flavipes</i> HN4-13 from a Lianyungang coastal sediment sample. The structures were elucidated by spectroscopic evidence. Compounds <b>4</b>–<b>6</b> and <b>9</b> were noncompetitive α-glucosidase inhibitors with <i>K</i>_i/IC₅₀ values of 0.43/34, 2.1/37, 0.79/19, and 2.8/90 μM, respectively. Compounds <b>1</b>–<b>3</b>, <b>8</b>, <b>10</b>, and <b>13</b> are mixed α-glucosidase inhibitors with <i>K</i>_i/IC₅₀ values of (2.5, 19)/44, (3.4, 14)/57, (9.2, 4.7)/95, (6.3, 5.5)/55, (1.4, 0.60)/9.9, and (2.5, 7.2)/33 μM, respectively (IC₅₀ 101 μM for acarbose and 79 μM for 1-deoxynojirimycin)