bluuebunny/crossref_metadata_2025 huggingface dataset:
INVESTIGATION OF PHYSICOCHEMICAL PROPERTIES OF STYRENE-ACRYLIC AND URETHANE POLYMERS USED IN FINISHING OF TEXTILE MATERIALS
Authors: Slepchuk Inna , Semeshko Olga Ya. , Asaulyuk Tatyana S. , Saribyekova Yuliya G.
Published: May 2020

The results of the study of the physicochemical properties of styrene-acrylic and urethane polymer films, as well as polymer compositions based on the studied polymers with the addition of crosslinking agents are presented. Aqueous dispersions of styrene-acrylic polymers Lacritex 309, Lacritex 430, Lacritex 640 and polyurethane polymer Aquapol 14 were used for the formation of films. Triglycidyl esthers of polyoxypropylene triol and trimethylolpropane — Laproxid 703 and Laproxid TMP — were used as crosslinking agents. The stability of polymer films to hydrolytic destruction was evaluated after treatment at 20, 40 and 100 °C, and to the soap-soda treatment — at 40 °C. It was found that the most resistant to hydrolysis and soap-soda treatment are films from styrene-acrylic polymer Lacritex 309 and compositions Lacritex 640 / Laproxid 703, Aquapol 14 / Laproxid TMP, Aquapol 14 / Laproxid 703. The tensile load, elongation at break, stiffness and surface tackiness were also determined for the studied polymer films. It was found that polymer films based on Lacritex 309 and compositions Lacritex 640 / Laproxid 703, Aquapol 14 / Laproxid 703 are characterized by the greatest strength and elongation, non-rigid and non-tacky surface. Adding Laproxid TMP to polyurethane Aquapol 14 provides creation of a solid and inelastic film. To assess the effect of polymer coatings on the textile material rigidity, a cotton fabric with twill weave was used, which is used for special work clothes. Polymers and their compositions were applied to the fabric from a solution with a concentration of 150 g/l, followed by drying and heat setting. For dressed cotton fabric, rigidity and breaking load were determined. The rigidity of the treated cotton fabric was determined by the method of console. It has been established that the use of polyurethane Aquapol 14 and compositions based on it, as well as styrene-acrylic dispersions Lacritex 309 and Lacritex 430 will result in hard handle of textile materials. The composition based on Lacritex 640 with the addition of Laproxid 703 as a crosslinker provides an elastic and strong textile material.
SYNTHESIS AND STRUCTURE OF METHYLTRIPHENYLPHOSPHONIUM DICYANODIBROMOAURATE [Ph3PCH3] [Au(CN)2Br2]
Authors: Efremov Andrey N. , Sharutin Vladimir V. , Sharutina Olga K. , Andreev Pavel V. , Eltsov Oleg S.
Published: May 2020

Methyltriphenylphosphonium dicyanodibromoaurate (1) [Ph3PMe]+[Au(CN)2Br2]– was synthesized by the reaction of potassium dicyanodibromoaurate with methyltriphenylphosphonium bromide in an aqueous solution and was structurally characterized. The complex is a yellow-colored, air-resistant crystalline substance with a clear melting point. The structure of the compound was established by IR spectroscopy, NMR spectroscopy and X-ray diffraction analysis. An intense absorption band was observed in the IR spectrum of compound at 2220 cm−1, corresponding to the stretching vibrations of cyano groups. The absorption band of the deformation vibrations of the P – СPh bonds in the IR spectrum is at 1438 cm−1. In the recorded 1Н, 13С, and 31Р NMR spectra, signals are observed for the number, value of chemical shifts and integral intensity that do not contradict the proposed complex structure. The X-ray diffraction analysis of crystal 1 was carried out on a Bruker D8 QUEST diffractometer (MoKα radiation, λ = 0.71073 Å, graphite monochromator). [C21H18AuBr2N2P, M = 686.13, crystal system triclinic, space group P-1, a = 8.802(5), b = 8.989(5), c = 15.233(11) Å, V = 1143.8(13) Å3, Z = 2, µ = 10.002 mm-1, F(000) = 644, crystal size 0.41×0.30×0.22 mm]. According to the X-ray diffraction analysis (XRDA) data there are two types of centrosymmetric crystallographically independent monomeric dicyanodibromoaurate anions and methyltriphenylphosphonium cations in the crystal of compound MFDDA. The cations have a distorted tetrahedral configuration: the CPC angles equal 108.8(2)°−110.0(2)°, the P−С distances are 1.791(5)−1.800(5) Å. All СAuC and BrAuBr trans-angles are 180.0° in the [Au(CN)2Br2]− anions. The Au−C distances in anions differ from each other and equal 2.040(7), 2.024(1), 1.991(2) Å. These values are close to the sum of the covalent radii of atoms (2.03 Å). The Au-Br bond lengths are equal to 2.4162(14), 2.4591, 2.474(5) Å in dicyanodibromoaurate anions. Formation of the crystal structure occurs due to formation of weak N···Н−С hydrogen bonds between cations and anions (2.68, 2.59, 2.38 Å) and Br···Н−С (3.03, 3.02 Å). Complete tables of coordinates of atoms, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Centre.
MOLECULAR MODELING OF ADSORPTION OF POLLUTANT GASES ON CADMIUM-CONTAINING POLYACRYLONITRILE
Authors: Avilova Marta M. , Mar'yeva Ekaterina A. , Popova Olga V. , Ivanova Tat'yana G.
Published: May 2020

The paper presents theoretical studies of the adsorption of pollutant gases on the surface of cadmium-containing polyacrylonitrile (Cd-polyacrylonitrile) in the absence and presence of water molecules and oxygen molecules in the environment. The list of gases to which the Cd-polyacrylonitrile surface may have the highest sensitivity is determined. Nitrogen dioxide, methane, ammonia, sulfur oxide (II), hydrogen sulfide, ozone, carbon monoxide, carbon oxide (II), chlorine were chosen as pollutant gases. The following software packages are used for modeling: HyperChem, Gaussian 09, Сhemoffice 2010. Polyacrylonitrile macromolecule models were obtained from HyperChem, Gaussian 09, from which a pentamer macromolecule was chosen to produce a Cd-polyacrylonitrile cluster. Then, implementing the molecular mechanics method in Сhemoffice 2010, namely in the Chem3D subroutine, the Cd-polyacrylonitrile cluster model is constructed. Further, using the molecular modeling method, the following thermodynamic parameters were determined: «Cd-polyacrylonitrile cluster – gas molecule», «Cd-polyacrylonitrile cluster – oxygen molecule», «Cd-polyacrylonitrile cluster – water molecule», «Cd-polyacrylonitrile cluster – oxygen molecule gas molecule», «Cd-polyacrylonitrile cluster – water molecule – gas molecule». As a result of molecular modeling, it was established that Cd-polyacrylonitrile in the atmospheric air exhibits selective sensitivity to gaseous chlorine and carbon monoxide; in an oxygen-free environment – also to hydrogen sulfide. The results of molecular modeling confirm the previously obtained experimental data on the evaluation of the gas sensitivity of Cd-polyacrylonitrile and indicate the presence of van der Waals forces between the Cd-polyacrylonitrile and the adsorbed gas molecule. The presence or absence of water molecules in atmospheric air should not affect the change in the sensitivity of Cd-polyacrylonitrile to pollutant gases.
ACYCLOVIR-SILICA COMPOSITE AS PLATFORM FOR DEVELOPMENT OF NOVEL ORAL DOSAGE FORM OF DRUG WITH PROLONGED RELEASE
Authors: Akimsheva Elizaveta Yu. , Dolinina Ekaterina S. , Parfenyuk Elena V.
Published: May 2020

In this work the possibility of creation of novel dosage form of acyclovir based on colloid silica for oral administration, which is capable of long sustained release of the drug is estimated. Clinical practice has shown that the traditional oral dosage form of acyclovir has serious drawbacks, one of which is the rapid elimination of the drug from the body. Colloid silica is recognized as a safe food additive in Russia and around the world. This is of particular importance for the development of drug oral dosage forms. The composite was synthesized by acid-catalyzed sol-gel reactions (hydrolysis and polycondensation) of tetraethoxysilane. The acyclovir solution was introduced into the prehydrolyzed silica sol. In experiments in vitro, a kinetic release profile of acyclovir encapsulated in the silica matrix was obtained. The amount of the released drug was determined spectrophotometrically using a spectrometer Carry 100, Varian, Australia. An experimental simulation of kinetics of the release of acyclovir from the synthesized composite in various sections of the gastrointestinal tract was carried out taking into account the literature data on drug transit time through the sections and medium pH in them. The results obtained in this work showed that the sol-gel encapsulation of acyclovir in silica matrix led to the formation of the acyclovir-silica composite, which is able to maintain the concentration of the drug in various sections of the gastrointestinal tract for 26 h regardless of the medium acidity and transit time of the drug through the sections. Thus, the synthesized composite of acyclovir with silica can serve as a platform for further development of a new oral dosage form of prolonged action.
INVESTIGATION OF ELECTROCHEMICAL PROPERTIES OF SILVER NANOPARTICLES CONJUGATED WITH ANTIBODIES TO TICK-BORNE ENCEPHALITIS FOR DEVELOPMENT OF ELECTROCHEMICAL IMMUNOSENSOR
Authors: Khristunova Ekaterina P. , Kratochvil Bohumil , Dorozhko Elena V. , Korotkova Elena I.
Published: May 2020

In the past decade, interest to electrochemical assays have grown for determination antibodies in clinical and biological samples, where instead of the enzyme label metal nanoparticle is used. Such types of electrochemical immunosensors represent an upcoming trend in analytical chemistry. In this work, the electrochemical behavior of silver nanoparticles conjugated with antibodies to tick-borne encephalitis virus at different stages of electrode modification is investigated. Silver nanoparticles were obtained by chemical reduction from silver nitrate. Passive adsorption was chosen as a strategy for binding silver nanoparticles to antibodies to tick-borne encephalitis virus. The optimal ratio of antibodies to tick-borne encephalitis virus (4.5 IU ml-1) in a solution of silver nanoparticles [1 mmol l-1 AgNO3] was found experimentally. The development of an electrochemical immunosensor was based on indirect, non-competitive format of enzyme-linked immunosorbent assay. The electrochemical situation on the electrode surface after modification steps was demonstrated by cyclic voltammetry using a standard redox pair [Fe(CN)6]3-/[Fe(CN)6]4-. Glassy carbon electrode with electrochemically deposited gold nanoparticles was used as a platform for immobilization of biological material. It has been established that after sensitization of the electrode with antigen, passivation of the surface occurs. The voltammetric signal was recorded through the detection of silver ions oxidation on unmodified glassy carbon electrode under the working conditions: scan rate 0.1 V s-1, potential accumulation –0.8 V, accumulation time 60 s. Thus, this work paves the way for a new alternative method for monitoring antibodies to tick-borne encephalitis virus in biological fluids.
MAGNETOCALORIC EFFECT AND HEAT CAPACITY OF MAGNETIC FLUIDS
Authors: Korolev Viktor V. , Ramazanova Anna G. , Balmasova Olga V. , Gruzdev Matvey S.
Published: May 2020

The magnetic fluids based on magnetite nanoparticles were synthesized using mixed surfactants (oleic acid/alkenyl succinic anhydride) dispersed in different carrier media (polyethylsiloxane and dialkyldiphenyl). The physicochemical properties of magnetic fluids (density, viscosity, saturation magnetization, magnetic phase concentration, magnetic core size) were determined. Magnetic fluids are stable in a wide temperature range. All the samples of the magnetic fluids exhibit typical superparamagnetic behavior. The magnetocaloric effect and the specific heat capacity of the magnetic fluids were first direct determined at 288–350 K in a magnetic field of 0–1.0 T. The field dependences of the magnetocaloric effect have a classic linear form. The temperature dependences of the magnetocaloric effect of magnetic fluids in magnetic fields have an extreme character. Thermodynamic parameters of magnetic fluids (magnetization namely enthalpy/entropy change) were determined. The specific heat capacity of magnetic fluid samples in a zero magnetic field was obtained at different temperatures (at 278–350 K) on a differential scanning calorimeter and on the original microcalorimeter. The temperature dependences of the heat capacity of magnetic fluids in magnetic fields have an extreme character. It was established that the difference in heat capacity values obtained in and without the magnetic field is within the experimental error. The extreme character of the heat capacity is reflected in the magnetocaloric effect temperature dependences.
INFLUENCE OF MANGANESE ON FORMATION OF ACTIVE PHASE OF COBALT CATALYST OF HYDROCARBON SYNTHESIS
Authors: Sulima Sergey I. , Saliev Alexey N. , Chistyakova Natalya S. , Savost’yanov Alexander P. , Bakun Vera G. , Shabelskaya Nina P.
Published: May 2020

The active phase and catalytic properties of cobalt catalysts of Fischer-Tropsch synthesis promoted with manganese and prepared by impregnation were studied. KSKG silica gel having a monodisperse structure with an average pore diameter of 12–16 nm was used as a support. The cobalt content in the obtained samples was 20.8-21.8 wt.%, manganese content was 0.5–2 wt.%. The structural characteristics of the catalysts were investigated by X-ray diffraction, transmission electron microscopy, temperature-programmed reduction and temperature-programmed hydrogen desorption. The catalytic activity and selectivity of the samples in the process of hydrocarbon synthesis were researched in the flow mode at a pressure of 0.1 MPa, at a Gas Hourly Space Velocity (GHSV) of 100 h–1, at the temperatures of 150–220 °C and a ratio of CO to hydrogen in synthesis gas of 2:1. Preliminary reduction of catalysts was carried out with hydrogen at a temperature of 400 °C. In the composition of the studied samples with manganese the formation of solid solutions of metals such as xCo3O4–(1–x)Mn3O4 was confirmed. It is shown that the reduction process of Co3O4 is determined by the composition and structure of solid solutions of components that are hard-to-recover compounds. The features of the promoting action of manganese depending on the concentration are determined. The introduction of 0.5–2 wt.% manganese allows to regulate the composition and microstructure of cobalt oxide compounds, the properties of metallic Co, increases the catalytic characteristics: activity, selectivity for C5+ and reduces the yield of methane. It is shown how, depending on the content of the metal additive, the manifestations of the structural (at a concentration of 0–1 wt.%) or electronic (at a concentration of  2 wt.%) promoting action of manganese increase. The optimum concentration of manganese is 1 wt.%. The catalyst is characterized by the minimum average size of crystallites, the highest value of the specific surface of cobalt metal and the maximum catalytic indicators.
DEVELOPMENT OF STEP-BY-STEP METHOD FOR PRODUCING SILVER NANOPARTICLES BY CITRATE METHOD
Authors: Bogacheva Natalya V. , Tarbeeva Ksenia A. , Ogorodova Natalya Yu.
Published: May 2020

The article presents an algorithm for developing a step-by-step method for producing silver nanoparticles 30-35 nm in size, taking into account the establishment at each stage of the necessary ratio of concentrations and volumes of reagents. In the work, silver nitrate and sodium citrate anhydrous were used by «Sigma-Aldrich» (USA). All test solutions were prepared by the gravimetric method. To weigh the reagents, we used Adventurer electronic analytical balances («OHAUS», USA) (with a resolution of 0.0001 g). The size and density of silver nanoparticles were estimated using a JEM-1011 electron transmission microscope («Jeol», Japan). In the course of the study, a direct dependence of the size of the nanoparticles on the concentration of solutions of sodium citrate and silver nitrate was established. According to the results of the first stage, the concentration ratio of AgNO3 : Na3C6H5O7 – 1 : 0.75 was chosen for testing the synthesis of colloidal silver nanoparticles. At the second stage, the influence of the ratios of the volumes of reagents on the conditionability of the obtained series was evaluated. The best result was obtained in the series with the volume ratio of AgNO3 : Na3C6H5O7 – 5 : 1, where single conglomerates were observed, and the particle shape was regular and round. At the next stage, the optimal boiling time of the colloidal solution after the appearance of a light yellow color was experimentally determined. With an increase in the boiling time of the solution, stabilization of particles occurs, thereby aggregative stability is observed. The most appropriate reagent mixing mode using a magnetic stirrer was selected: after the appearance of a light yellow color, the number of revolutions was changed from 375 to 500 rpm and the temperature regime was decreased from 300 °C to 200 °C.
SYNTHEIS OF NI IMPREGNATED HYPERCROSSLINKED POLYSTERENE FOR CATALITIC HYDROGENATION OF D-GLUCOSE
Authors: Brovko Roman V. , Doluda Valentin Yu. , Lefedova Olga V. , Tarasyuk Ilya A. , Filippov Dmitry V. , Latypova Adele R.
Published: May 2020

Development of efficient catalysts is in focus of modern chemical technology for production of fine chemicals. D-sorbitol is widely used as sweetener, food additive and fuel compound is typically produced by D-glucose hydrogenation over Ni-Reney catalyst. However, this catalyst is characterized by not sufficient stability and selectivity to D-sorbitol formation. The described study is devoted to synthesis of nickel containing hypercrosslinked polystyrene for D-glucose hydrogenation process. Hypercrosslinked polystyrene is one of the representatives of crosslinked polymers with rigid matrix applicable for metal nanoparticles synthesis. However, hypercrosslinked polystyrene is characterized by high surface hydrophobicity that prevent impregnation of high amount of active metal over it surface. To overcome this disadvantage hypercrosslinked polystyrene was modified by hydrogen peroxide, chlorine and ammonia. A series of nickel based catalyst theoretically containing 25wt.% of nickel were synthesized. Modification of hypercrosslinked polystyrene results in appropriate increase in surface concentration of active metal. Synthesized Ni based catalysts were characterized by comparable Ni loading varying from 20.1 wt.% to 23.2 wt.%. Some increase in Ni loading can be subscribed to presence of surface-active groups in a case of modified hypercrosslinked polystyrene application. Mesopores surface area decrease from 126 m2/g to 69 m2/g in case of catalysts on modified hypercrosslinked polystyrene. Catalytic hydrogenation of D-glucose over synthesized Ni-containing catalysts showed considerable increase in turnover frequency (TOF) for all samples compare to commonly used Reney type nickel. Increase in TOF can be subscribed to appropriate increase of active metal surface concentration. Beside, some increase in catalyst selectivity to sorbitol took place. Considerable improvement of selectivity to sorbitol can be explained by increasing of desired D-glucose hydrogenation reaction rate, while reaction rate of D-glucose isomerization process to D-fructose remain the same. The achieved TOF for most active catalyst was found to be 0.27 s-1 and catalysts selectivity to D-sorbitol 98%.
SYNTHESIS OF GALLIUM COMPLEXES OF TERT-BUTYLSUBSTITUTED ACYCLIC AND CYCLIC COMPOUNDS BASED ON 3,5-DIAMINO-1,2,4-TRIAZOLE
Authors: Kustova Tatyana V. , Rogova Elena A. , Sinitsyn Alexander M.
Published: May 2020

Synthetic methods of organic chemistry which are currently available in scientific literature allow obtaining a large number macroheterocycles with structurally different internal coordination cavities. They also provide a number of convenient ways to attach to a macrocyclic platform various biologically active heterocyclic fragments such as guanazol. This paper discusses the synthesis and composition of gallium complexes of cyclic and acyclic compounds based on 3,5-diamino-1H-1,2,4-triazol (guanazol), which is itself widely used in medical practice and, most importantly, for the treatment of cancer, in particular, breast cancer ("Anastrozole", "Letrozole"). Interest in gallium compounds is associated with the discovery of a high tropicity of this element to the DNA of tumor cells, as well as cells of the reticuloendothelial system (macrophages and lymphocytes). Therefore, the synthesis of new potential drugs with gallium salts for tumor chemotherapy is an urgent task. The gallium complex of a macroheterocyclic compound of symmetrical structure based on guanazole was obtained through the formation of a three-unit product - 3,5-bis - (5 (6)-tert-butyl-3-iminoisoindoline-1-ilidenamino)-1,2,4-triazole and its complex, followed by cyclization of 3,5-diamino-1H-1,2,4-triazole in phenol. The structure of the obtained compounds was proved using modern physicochemical research methods (UV, IR, NMR spectroscopy, mass spectrometry, and elemental analysis). In the mass spectra of the obtained compounds there are peaks of molecular ions of the target products and their fragmentation products. The coincidence of the m/z values with the mass of molecular ions, as well as the characteristic distributions of molecular ions with the calculated values, confirms the composition of the synthesized gallium complexes.
HETEROCYCLIZATION OF 3-PROPARGYLSULFANYL-5 PHENYL-1,2,4-TRIAZINE: TANDEM REACTIONS WITH BROMINE LEADING TO NEW DERIVATIVES OF 7 PHENYL[1,3]THIAZOLO[3,2-B][1,2,4]TRIAZINIUM
Authors: Rybakova Anastasiya V. , Kim Dmitry G. , Danilina Elena I. , Sazhaeva Olesya V. , Ezhikova Marina A. , Kodess Mikhail I.
Published: May 2020

Derivatives of 1,2,4-triazine-3-thione exhibit biological activity in a wide range. They have optoelectronic properties and can be used as synthons in synthesis of various pyridines by the Diels-Alder reaction. 1,2,4-Triazines are of the greatest interest, for organic synthesis in particular. In the present study we have established that the interaction of 3-propargylsulfanyl-5-phenyl-1,2,4-triazine, obtained by alkylation of 5-phenyl-2,3-dihydro-1,2,4-triazine-3-thione with 3-bromopropyne in acetone in the presence of triethylamine, with halogens leads to annelation of thiazole cycle. At that, [1,3]thiazolo[3,2-b][1,2,4]triazinium systems contain either endo- or exocyclic double bond in their structure, depending on the halogen type. By way of example, iodine acting on propargyl sulfide forms a dark precipitate of (3Z)-3-iodomethylene-7-phenyl-2,3-dihydro-[1,3]thiazolo[3,2-b][1,2,4]triazinium triiodide, the structure of which has been confirmed by 1H and 13C NMR spectroscopy, including two-dimensional 2D  1H-13C HSQC, HMBC and 1H-1H NOESY experiments. Treatment of the obtained triiodide by sodium iodide in acetone leads to synthesis of the corresponding monoiodide, which precipitates from the reaction mixture as a dark red precipitate. Reaction with bromine, as distinct from heterocyclization under iodine action, comprises an unusual cascade reaction including the stages of electrophile heterocyclization, bromine addition, and hydrogen bromide elimination, which leads to formation of 3-dibromomethyl-7-phenyl[1,3]thiazolo[3,2-b][1,2,4]triazinium bromide. It should be pointed out that the identifying feature of 3-propargylsulfanyl-5-phenyl-1,2,4-triazine  heterocyclization under iodine and bromine action is the signal bias of the aromatic proton in a triazine ring towards weak field in the 1H NMR spectrum of the reaction products. This is presumably associated with formation of the positively charged nitrogen atom.
SOLVING INVERSE PROBLEM OF CHEMICAL KINETICS WITH USE OF CUBIC SPLINES
Authors: Kol'tsov Nikolay I.
Published: May 2020

A simple effective method for solving the inverse problem of chemical kinetics based on non-stationary experiments for multistage reactions occurring in an isothermal reactor of ideal mixing is described. The idea of the method is based on taking into account the distinctive features (informativeness) of different fragments of relaxation curves for chemical reactions with arbitrary (non-monotonic) kinetics and their as accurate approximation as possible. For this purpose, non-linear (cubic) splines are used to describe different informative fragments of relaxation curves, which allow to approximate and interpolate experimental data as accurately as possible. An additional advantage of cubic splines, from the point of view of the implementation of the described method, is their continuity at all given points up to and including second-order derivatives (smoothness). This allows us to calculate with good accuracy not only the concentration of reagents, but also the instantaneous rate of change at any time. The consequence of this is the possibility of a sufficiently accurate solution of the inverse problem based on the data of non-stationary experiments. The correctness of the mathematical model used and the stability of the method were tested using variations of the original data. An example of using the method for determining the intervals of physical values of the rate constants of the stages of a two-stage reaction is given. The influence of the method of selecting the reference points (structure) of the spline and measurement errors (noise) of experimental data on the error of determining the speed constants of the stages is estimated. The efficiency of application and good accuracy of the method for solving the inverse problem of chemical kinetics of multistage reactions occurring in non-gradient systems with taking into account of noise is shown.
Appalling! Terrifying! Wonderful! Blaxploitation and the Cinematic Image of the South
Authors: Górny Antoni
Published: May 2020

The so-called blaxploitation genre — a brand of 1970s film-making designed to engage young Black urban viewers — has become synonymous with channeling the political energy of Black Power into larger-than-life Black characters beating “the [White] Man” in real-life urban settings. In spite of their urban focus, however, blaxploitation films repeatedly referenced an idea of the South whose origins lie in antebellum abolitionist propaganda. Developed across the history of American film, this idea became entangled in the post-war era with the Civil Rights struggle by way of the “race problem film,” which identified the South as “racist country,” the privileged site of “racial” injustice as social pathology. Recently revived in the widely acclaimed works of Quentin Tarantino (Django Unchained) and Steve McQueen (12 Years a Slave), the two modes of depicting the South put forth in blaxploitation and the “race problem” film continue to hold sway to this day. Yet, while the latter remains indelibly linked, even in this revised perspective, to the abolitionist vision of emancipation as the result of a struggle between idealized, plaintive Blacks and pathological, racist Whites, blaxploitation’s troping of the South as the fulfillment of grotesque White “racial” fantasies offers a more powerful and transformative means of addressing America’s “race problem.”
Bataille in the South: James Agee’s Let Us Now Praise Famous Men and Erskine Caldwell’s Depression Fiction
Authors: Kuhn Joseph
Published: May 2020

This article tries to show how James Agee in Let Us Now Praise Famous Men (1941) and Erskine Caldwell in his fiction from the Depression years–especially the little-known novella, The Sacrilege of Alan Kent (1930)–used a discourse of the sacred to represent the strange otherness of the Depression South. They particularly drew on the “left hand sacred” (of taboo, repulsiveness and sacrifice) as distinct from the “right hand sacred” found in institutional religion. The article argues that a theoretical understanding of Agee and Caldwell’s use of the sacred may be provided by Georges Bataille. It seems particularly appropriate to invoke Bataille since he was concerned with the political elements of the sacred and sought to mobilize these elements during the 1930s when liberal democracy was thought by many leftist writers on both sides of the Atlantic to have failed. Bataille provides a productive analogue to the two southerners, who shared this perception of liberal democracy, because he tried to articulate a radical path in this decade that was not Marxist. Agee and Caldwell, although notionally Communist, were dissatisfied with Marxism because they saw it as another version of a utilitarian or restricted economy. They looked instead to the sacred as a discourse of transgression–a discourse that was rooted in what Bataille called a general economy or the deeper organization of collective life around ecology and the gift.
Fast and reversible neural inactivation in macaque cortex by optogenetic stimulation of GABAergic neurons
Authors: De Abhishek , El-Shamayleh Yasmine , Horwitz Gregory D
Published: May 2020

Optogenetic techniques for neural inactivation are valuable for linking neural activity to behavior but they have serious limitations in macaques. To achieve powerful and temporally precise neural inactivation, we used an adeno-associated viral (AAV) vector carrying the channelrhodopsin-2 gene under the control of a Dlx5/6 enhancer, which restricts expression to GABAergic neurons. We tested this approach in the primary visual cortex, an area where neural inactivation leads to interpretable behavioral deficits. Optical stimulation modulated spiking activity and reduced visual sensitivity profoundly in the region of space represented by the stimulated neurons. Rebound firing, which can have unwanted effects on neural circuits following inactivation, was not observed, and the efficacy of the optogenetic manipulation on behavior was maintained across >1000 trials. We conclude that this inhibitory cell-type-specific optogenetic approach is a powerful and spatiotemporally precise neural inactivation tool with broad utility for probing the functional contributions of cortical activity in macaques.
Sox8 and Sox9 act redundantly for ovarian-to-testicular fate reprogramming in the absence of R-spondin1 in mouse sex reversals
Authors: Richardson Nainoa , Gillot Isabelle , Gregoire Elodie P , Youssef Sameh A , de Rooij Dirk , de Bruin Alain , De Cian Marie-Cécile , Chaboissier Marie-Christine
Published: May 2020

In mammals, testicular differentiation is initiated by transcription factors SRY and SOX9 in XY gonads, and ovarian differentiation involves R-spondin1 (RSPO1) mediated activation of WNT/β-catenin signaling in XX gonads. Accordingly, the absence of RSPO1/Rspo1 in XX humans and mice leads to testicular differentiation and female-to-male sex reversal in a manner that does not requireSry or Sox9 in mice. Here we show that an alternate testis-differentiating factor exists and that this factor is Sox8. Specifically, genetic ablation of Sox8 and Sox9 prevents ovarian-to-testicular reprogramming observed in XX Rspo1 loss-of-function mice. Consequently, Rspo1 Sox8 Sox9 triple mutant gonads developed as atrophied ovaries. Thus, SOX8 alone can compensate for the loss of SOX9 for Sertoli cell differentiation during female-to-male sex reversal.
Paranoia as a deficit in non-social belief updating
Authors: Reed Erin J , Uddenberg Stefan , Suthaharan Praveen , Mathys Christoph D , Taylor Jane R , Groman Stephanie Mary , Corlett Philip R
Published: May 2020

Paranoia is the belief that harm is intended by others. It may arise from selective pressures to infer and avoid social threats, particularly in ambiguous or changing circumstances. We propose that uncertainty may be sufficient to elicit learning differences in paranoid individuals, without social threat. We used reversal learning behavior and computational modeling to estimate belief updating across individuals with and without mental illness, online participants, and rats chronically exposed to methamphetamine, an elicitor of paranoia in humans. Paranoia is associated with a stronger prior on volatility, accompanied by elevated sensitivity to perceived changes in the task environment. Methamphetamine exposure in rats recapitulates this impaired uncertainty-driven belief updating and rigid anticipation of a volatile environment. Our work provides evidence of fundamental, domain-general learning differences in paranoid individuals. This paradigm enables further assessment of the interplay between uncertainty and belief-updating across individuals and species.
Partnering With Patients to Reduce Firearm-Related Death and Injury
Authors: Ozuna Luis , Champion Carisa , Yorkgitis Brian K.
Published: May 2020

In the United States, nearly 40,000 deaths per year are firearm related. Among these fatalities are approximately 1300 children. In addition, there are more than 20,000 unintentional firearm injuries per year. Osteopathic physicians have a unique opportunity to affect this public health concern through patient education. Several evidenced-based recommendations can be incorporated at the bedside to reduce firearm injuries and deaths, including gun education, safe storage, and proper disposal.
Integrating Osteopathic Manipulative Treatment and Injections in the Diagnosis and Management of a Hip Labral Tear
Authors: Snyder Laura L. , Knox Shaun C. , Smutny Charles J.
Published: May 2020

Hip pain in adults is a common complaint. Secondary processes can often mask underlying conditions, prolonging the course to diagnosis and definitive treatment. In this case, a 74-year-old man presented to an outpatient clinic after 6 weeks of right hip pain that began upon initiation of a rehabilitation program following coronary artery bypass graft surgery. Various imaging and treatment modalities (including radiography, osteopathic manipulative treatment, injection of the greater trochanteric bursa, L2-3 paravertebral block, magnetic resonance imaging, and intra-articular hip injection with 1% lidocaine) ultimately led to the definitive diagnosis of a labral tear. This case report highlights how a comprehensive osteopathic approach was used to evaluate and treat a patient with persistent unilateral hip pain because of an acetabular labral tear, associated psoas syndrome, and trochanteric bursitis, all within 2 months and with a positive clinical outcome.
Descriptions of five new species of the salamander genusChiropterotriton(Caudata: Plethodontidae) from eastern Mexico and the status of three currently recognized taxa
Authors: Parra Olea Gabriela , Garcia-Castillo Mirna G. , Rovito Sean M. , Maisano Jessica A. , Hanken James , Wake David B.
Published: May 2020

The genusChiropterotritonis endemic to Mexico with a geographical distribution along the Sierra Madre Oriental, the Trans Mexican Volcanic Belt and the Sierra de Juárez. The recent use of molecular tools has shown that Mexico’s amphibian diversity is highly underestimated, including a large number of cryptic, unnamed species.Chiropterotritonhas 18 described species including terrestrial, arboreal and cave-dwelling species. In previous molecular studies, the presence of multiple undescribed species was evident. We present a phylogenetic hypothesis based on mitochondrial data, which includes all described species and six undescribed taxa. Based on the morphological analyses and, when available, combined with molecular data, we describe five new species of the genus;Chiropterotriton casasisp. nov.,C. ceronorumsp. nov.,C. meliponasp. nov.,C. perotensissp. nov. andC. totonacussp. nov. In addition, we redescribe two others:Chiropterotriton chiropterusandC. orculus, and provide a comparable account of one additional sympatric congener. This increases the number of species in the genus to 23, which represent a considerable component of Mexican plethodontid richness.
Hamstring extensibility differences among elite adolescent and young dancers of different dance styles and non-dancers
Authors: Vaquero-Cristóbal Raquel , Molina-Castillo Patricia , López-Miñarro Pedro A. , Albaladejo-Saura Mario , Esparza-Ros Francisco
Published: May 2020

Background

Hamstrings have been analyzed extensively due to their tendency to shorten and their effect in the lumbo-pelvic dynamics and the sagittal position of the spine in trunk flexion with extended knees positions. It has been demonstrated that practicing a certain sport results in long-term changes in hamstring extensibility. Despite this, adequate extensibility of the hamstring musculature is essential for the dancer’s performance. Several studies have found differences in the extensibility of the hamstrings depending on the dance style, but none have compared ballet, Spanish dance and modern dance. The purpose of the present research was to analyze the differences in hamstring extensibility among professional dance students based on dance style practiced and non-dancers.

Methods

The sample was comprised of 210 students from the Professional Dance Conservatory (70 for ballet, 70 for Spanish dance and 70 for modern dance) and 70 non-dancers. For the assessment of hamstring extensibility, the angle in the passive and active straight leg raise (PSLR and ASLR, respectively) test, and the scores of the pelvic tilt in sit-and-reach (SR) test and the toe-touch (TT) test were randomly conducted.

Results

The results showed significant differences for all the tests according to group (p< 0.001). In the PSLR and ASLR test, for both legs, and in the pelvic tilt in the SR test, the ballet dancers showed greater ranges of hamstring extensibility than the modern dancers and Spanish dancers (p≤ 0.001). In the distance in the SR test and in the pelvic tilt in the TT test, the ballet dancers obtained higher values than the Spanish dancers (p= 0.004 andp= 0.003, respectively). The modern dancers showed higher ranges of hip flexion than the Spanish dancers in the ASLR test for both legs and in the pelvic tilt in the SR test (pfrom 0.007 to <0.001). Dancers showed significantly higher hamstring extensibility than non-dancers in all the tests (p< 0.001).

Conclusions

The systematic practice of dance, regardless of the style, seems to lead to high ranges of hamstring extensibility. Ballet dancers have the greatest hamstring extensibility.
Prediction of Genotypic Values and Selection Gains in Peanut Lines Derived from a Synthetic Amphidiploid
Authors: Ramos Jean Pierre Cordeiro , Dutra Wellison Filgueiras , Guerra Yrlânia de Lira , Luz Lucas Nunes da , Cavalcanti José Jaime Vasconcelos , Silva Carliane Rebeca Coelho da , Bertioli Soraya Leal , Bertioli David , Santos Roseane Cavalcanti dos
Published: May 2020

Genotypic values and selection gains were estimated in peanut lines derived from backcrossing with synthetic amphidiploid (A. batizocoi x A. duranensis)4x and a commercial cultivar, based on agronomical traits. Thirteen BC1F3 lines were grown in the field and submitted to 21 d of water suppression. Two earliness and drought tolerant cultivars (BR 1 and Senegal 55 437) were used as controls. Eight agronomic traits were adopted to characterize the lines. The estimates were based on mixed models (REML/BLUP) and Sum of Ranks Selection Index. We found that residual variance was greater than genotypic one, indicating the existence of variability within the families. Most traits showed high accuracy values. Three families showed an increased number of pods/plant, pod length and several seeds/pod. Negative gains were achieved for time for blooming and full pod maturation. As these traits are used as criteria for selection for earliness, these results favour the identification of short-cycle plants and prone to tolerate dry environments.
An examination of the Self‐Administered Interview as a verbal veracity assessment tool
Authors: Hudson Charlotte A. , Vrij Aldert , Akehurst Lucy , Hope Lorraine
Published: May 2020

The self‐administered interview (SAI) is a written eyewitness recall tool that elicits more information from cooperative witnesses than written free recall (WFR) formats. To date, SAI research has examined the accounts of cooperative people providing honest reports. In the current experiment, truthful and fabricating participants (N = 128) either completed a WFR or a SAI after witnessing a crime (initial account). After a 1‐week delay, participants were interviewed verbally (subsequent interview). Truth tellers reported significantly more detail than liars in both the initial account and subsequent interview, and participants who completed the SAI reported more detail than those completing the WFR. Truth tellers repeated and omitted more information in the subsequent interview than liars; however, there was no significant difference in the number of reminiscent details reported. Although the SAI is effective in eliciting information as an initial eyewitness reporting tool, no benefits for the detection of deception were demonstrated.
Donor and Acceptor Fused 16,16‐Dimethyl‐11,16‐dihydrodibenzo[2,3:5,6]pyrrolizino[1,7‐ab]acridine as a Blue‐Emitting Chromophore for High External Quantum Efficiency and Long Lifetime
Authors: Patil Vilas Venunath , Lee Kyung Hyung , Lee Jun Yeob
Published: May 2020

The rigid molecular assembly formed by the fusion of the donor type acridine and acceptor type indolo[3,2,1‐jk]carbazole, namely 16,16‐dimethyl‐11,16‐dihydrodibenzo[2,3:5,6]pyrrolizino[1,7‐ab]acridine (ACDID), is developed as a new chromophore to give narrow emission in the blue region. The functionalization of the chromophore with phenyl and triphenylamine gives two fluorescence emitters, ACDID‐Ph and ACDID‐TPA, respectively. The in‐depth study of the emitters has confirmed that the triphenylamine unit in the ACDID‐TPA emitter enhances the external quantum efficiency (EQE) along with device stability. The ACDID‐TPA emitter shows high EQE of 6.3% and small full width at half maximum of 39 nm by the rigidity of the chromophore. The ACDID‐derived blue emitter performs better than the conventional pyrene‐derived emitter in terms of device lifetime, demonstrating the potential of the donor‐ and acceptor‐fused ACDID as the chromophore of blue emitters.
Bright Green Emitting CaYAlO4:Tb3+,Ce3+ Phosphor: Energy Transfer and 3D‐Printing Artwork
Authors: Zhou Lei , Hong Junyu , Li Xiaohui , Shi Jianxin , Tanner Peter A. , Wong Ka‐Leung , Wu Mingmei
Published: May 2020

The environmentally friendly and low‐priced CaYAlO4:Tb3+ nanophosphors are combined with good optically transparent materials for the application in 3D printing. For ultraviolet (UV) light‐emitting diode excitation, CaYAlO4:Tb0.07Cey and CaYAlO4:Ce0.05Tbx nanophosphors are prepared by a sol–gel route and systematically studied for optimal excitation at 380 nm to give strong green emission to which human and aquatic animals eyes are generally sensitive. This is benefited from the dipole and spin allowed transition of Ce3+ and the 92.5% efficient energy transfer from Ce3+ to Tb3+ in this host. Polydimethylsiloxane, with 92% transmittance in the visible spectral region, is a valid choice to make the shaped artwork by a templating method, combined with the nanoparticles to give a uniform distribution, as determined by X‐ray microcomputed tomography. Polylactic acid is also employed to create a frog artwork by the fused deposition modeling method. The final 3D‐printed colorful artwork is displayed herein together with that produced by the templating method under different light source excitation to suggest a novel expression of aesthetic concepts and a potential application in the future marine environment such as a lamp to attract aquatic animals or a buoy to guide ships.
Refractory Ultrathin Nanocomposite Solar Absorber with Superior Spectral Selectivity and Thermal Stability
Authors: Raza Aikifa , Alketbi Afra S. , Devarapalli Rajakumar , Li Hongxia , Zhang TieJun
Published: May 2020

Highly efficient solar–thermal energy conversion requires refractory absorbers harnessing full spectrum of sunlight, minimal thermal emission, and structural stability at higher operating temperatures. Herein, an ultrathin ultrabroadband omnidirectional silicon carbide–tungsten (SiC‐W) refractory nanocomposite is fabricated by high‐throughput co‐sputtering with superior thermal and oxidation stability. The as‐fabricated SiC‐W nanocomposite (78 nm) deposited on tungsten layer with top anti‐reflective film exhibits high solar absorptance of 95.45% in the wide range of 250–2500 nm with thermal emittance below 0.05 at ambient temperature. The ultrabroadband absorption is achieved by plasmonic resonances triggered by self‐formed tungsten nanoclusters in the range of 500–1500 nm combined with SiC intrinsic absorption below λ < 500 nm. SiC as diffusion barrier also prevents interlayer diffusion and oxidation of tungsten nanoclusters to achieve superior thermal/oxidation stability, when annealed at 900 K (air) and 1050 K (vacuum). This work demonstrates outstanding capability of refractory nanocomposites in high‐performance solar thermal technologies for both terrestrial and space environments.
Distinguishing Optical and Acoustic Phonon Temperatures and Their Energy Coupling Factor under Photon Excitation in nm 2D Materials
Authors: Wang Ridong , Zobeiri Hamidreza , Xie Yangsu , Wang Xinwei , Zhang Xing , Yue Yanan
Published: May 2020

Under photon excitation, 2D materials experience cascading energy transfer from electrons to optical phonons (OPs) and acoustic phonons (APs). Despite few modeling works, it remains a long‐history open problem to distinguish the OP and AP temperatures, not to mention characterizing their energy coupling factor (G). Here, the temperatures of longitudinal/transverse optical (LO/TO) phonons, flexural optical (ZO) phonons, and APs are distinguished by constructing steady and nanosecond (ns) interphonon branch energy transport states and simultaneously probing them using nanosecond energy transport state‐resolved Raman spectroscopy. ΔTOP −AP is measured to take more than 30% of the Raman‐probed temperature rise. A breakthrough is made on measuring the intrinsic in‐plane thermal conductivity of suspended nm MoS2 and MoSe2 by completely excluding the interphonon cascading energy transfer effect, rewriting the Raman‐based thermal conductivity measurement of 2D materials. GOP↔AP for MoS2, MoSe2, and graphene paper (GP) are characterized. For MoS2 and MoSe2, GOP↔AP is in the order of 1015 and 1014 W m−3 K−1 and GZO↔AP is much smaller than GLO/TO↔AP. Under ns laser excitation, GOP↔AP is significantly increased, probably due to the reduced phonon scattering time by the significantly increased hot carrier population. For GP, GLO/TO↔AP is 0.549 × 1016 W m−3 K−1, agreeing well with the value of 0.41 × 1016 W m−3 K−1 by first‐principles modeling.
MLH1 Deficiency Induces Cetuximab Resistance in Colon Cancer via Her‐2/PI3K/AKT Signaling
Authors: Han Ying , Peng Yinghui , Fu Yaojie , Cai Changjing , Guo Cao , Liu Shanshan , Li Yiyi , Chen Yihong , Shen Edward , Long Kexin , Wang Xinwen , Yu Jian , Shen Hong , Zeng Shan
Published: May 2020

The rapid onset of resistance to cetuximab (CTX) limits its clinical utility in colorectal cancer (CRC) patients. This study aims to understand a potential role of mismatch repair gene mutL homolog 1 (MLH1) in CTX response. Functional analysis of MLH1 in Her‐2/phosphoinositide 3‐kinases (PI3K)/PKB protein kinase (AKT)‐regulated CTX sensitivity is performed using human CRC specimens, CRC cell lines with different MLH1 expression levels, and a subcutaneous xenograft model. Overexpression, knockdown, small interfering RNA, and inhibitors are used to examine the role of MLH1 and HER‐2 downstream signaling and apoptotic targets in CTX sensitivity. Reduced MLH1 expression is correlated with unfavorable prognosis in cetuximab‐treated patients. MLH1 loss decreases CTX sensitivity through Her‐2/PI3K/AKT signaling and apoptosis resistance in culture and in xenografts, while MLH1 overexpression increases CTX sensitivity. Blocking Her‐2 signaling increases CTX sensitivity of microsatellite instability CRC in vitro and in vivo. MLH1 loss induces activation of Her‐2/PI3K/AKT signaling and leads to cetuximab resistance in colon cancer.