bluuebunny/crossref_metadata_2025 huggingface dataset:
3 ungewöhnliche Verläufe von gastrointestinalen MALT-Lymphomen
Authors: Fischbach Wolfgang , Eck Matthias , Dorlöchter Christian
Published: August 2021

Wir berichten über den ungewöhnlichen Krankheitsverlauf von drei Patienten mit gastro-intestinalen MALT-Lymphomen. Besonderheiten sind die primäre Manifestation der Lymphome, die hochmaligne Transformation im weiteren Verlauf, der lange Zeitraum zwischen initial erfolgreicher kurativ intendierter Therapie und dem Rezidiv und das Auftreten einer weiteren Neoplasie in einem Fall. Dies zeigt, dass trotz der allgemein guten Prognose von gastrointestinalen MALT-Lymphomen Nachsorgeuntersuchungen sinnvoll sind.
Artischocke – Gemüsepflanze mit potenter Heilkraft
Authors: Chrubasik-Hausmann Sigrun
Published: August 2021

Trotz jahrzehntelanger, intensiver Forschung ist die Wirksamkeit der Artischocke noch immer nicht in klinischen Studien belegt. – Dennoch scheint eine Linderung von Verdauungsbeschwerden plausibel
Cantharidenpflaster bei Wirbelkanalstenose
Authors: Stör Wolfram
Published: August 2021

Die Wirkung von Akupunktur bei Schmerzen mit Claudicatio spinalis durch Wirbelkanalstenose ist begrenzt. Im Fallbericht wird gezeigt, wie die Anwendung des Cantharidenpflasters als ausleitendes Heilverfahren Hilfe bringen kann.
Zur Geschichte der Kehlkopftuberkulose
Authors: Luckhaupt Horst
Published: August 2021

Bis zur Einführung der Antituberkulotika in die Behandlung war die Kehlkopftuberkulose eine unheilbare, in der Regel zum Tode führende Infektionskrankheit. Seit dem 18. Jahrhundert erforschten Mediziner dieses Krankheitsbild; nach Fortschritten in der laryngologischen Diagnostik erfolgten medikamentöse Lokaltherapien, umschriebene operative Eingriffe, auch Versuche mit Röntgenstrahlen. Erst durch die Entwicklung der Tuberkulostatika (40er/50er-Jahre des letzten Jahrhunderts) verlor die Larynxtuberkulose ihren Schrecken.
Heilsame „Schockwelle“
Authors: Hayashi Kenji
Published: August 2021

Sotaiho entstammt als heilgymnastische Methode der traditionellen japanischen Medizin und dient dem Abbau von Gelenkfehlstellungen und Muskelverspannungen sowie der Schulung in Achtsamkeit und Körpergefühl. Durch Fehlbelastungen wie einseitige Bewegungen bei Rechts- oder Linkshändern oder falsches Aufheben verlagert sich der Körperschwerpunkt als Bewegungszentrum von der Körpermitte weg, mit Beckenschiefstand und Wirbelsäulenverkrümmungen als Folge. Für die Technik führt der Patient eine Bewegung (zum Beispiel des Unterschenkels) mit einer Ausatmung von der schmerzenden zur angenehmen Seite aus, woraufhin der Therapeut gegendrückt und der Patient nach 5 sec plötzlich entlastet – was wie eine heilsame „Schockwelle“ in den Körper hineinwirkt.
Auf gesunden Füßen stehen
Authors: Steinfurth Günter
Published: August 2021

Fußdeformitäten zu erkennen, ihre genaue Ursache zu ermitteln und entsprechend zu behandeln kann ausschlaggebend für die Besserung von Beschwerdebildern auch in anderen Körperregionen sein.

Sie lösen nicht nur Schmerzen aus und führen zu Haltungsschäden. Fehlstellungen und Deformierungen der Füße können über Muskel- und Faszienketten auch zu Beschwerden an Schulter, Nacken und Kopf führen.

Geübte können Fußdeformitäten bereits anhand des Gangbilds erkennen, differenzieren oder ausschließen. Die wichtigsten stellt Ihnen dieser Beitrag vor.
A Rh(II)- or Ag(I)-Catalyzed Formal C–O Bond Insertion of Cyclic Hemiaminal with Aryl Diazoacetate
Authors: Hu Wenhao , Xu Cong , Liu Xiangrong , Xie Xiongda , Deng Lin , Xu Xinfang , Chan Albert S. C.
Published: August 2021

A mild and facile synthetic method via convergent assembly of two reactive intermediates generated in situ has been developed. This method provides an efficient way to construct six- and seven-membered N-heterocycles containing a biaryl linkage. This reaction features a gem-difunctionalization process of diazo compounds with cyclic hemiaminals, delivering α-hydroxyl-β-amino ester derivatives with a tertiary carbon center through a formal C–O bond-insertion transformation.
Eficácia da biópsia vertebral percutânea guiada por fluoroscopia
Authors: Mireles-Cano José Nicolás , Gonzalez Alejandro Miranda , García-González Oscar Guillermo , Pérez Ricardo Martínez
Published: August 2021

Objetivo Definir a eficácia da biópsia vertebral percutânea guiada por fluoroscopia.

Métodos Este é um estudo prospectivo de pacientes com síndrome de destruição vertebral em uma instituição. Os pacientes foram submetidos a biópsias vertebrais transpediculares percutâneas guiadas por fluoroscopia, com obtenção de tecido ósseo e tecido do disco intervertebral, para estudo histopatológico e microbiológico. Idade, sexo, segmento vertebral, estado neurológico, e resultados de biópsia e de cultura foram analisados.

Resultados A idade média dos pacientes foi de 53,8 anos (gama: 2 a 83 anos), e o principal local acometido da coluna foi a segmento lombar, em 62% dos casos. Segundo a escala de disfunção da American Spinal Injury Association (ASIA), no pré-operatório, 49% dos pacientes foram classificados como ASIA E, e 100% apresentavam dor. A etiologia definitiva foi identificada em 83% dos pacientes. A etiologia foi agrupada em três categorias: infecciosa, neoplásica, e degenerativa (osteoporótica). O grupo infeccioso era composto por 36% dos pacientes da amostra, e Staphylococcus aureus foi o agente mais comumente identificado; em 34,9% dos casos, a etiologia era neoplásica, principalmente mieloma múltiplo e doença metastática por câncer de próstata; 21,7% dos pacientes apresentavam osteoporose. O tempo cirúrgico médio foi de 47,5 minutos, e a perda média de sangue foi de 10 mL. Nenhuma complicação foi relatada.

Conclusão Nesta série, a biópsia percutânea transpedicular guiada por fluoroscopia teve 83% de eficácia no diagnóstico etiológico da síndrome de destruição vertebral. Este procedimento minimamente invasivo deve ser considerado bom, fácil, barato e reprodutível, com baixo risco de complicações em curto e longo prazos.
Hálux valgo percutâneo: Um algoritmo de tratamento cirúrgico
Authors: Marijuschkin Igor , Souza Matheus Levy , Diaz José Luiz Garcia , Carvalho Paulo
Published: August 2021

Objetivo Apresentar os resultados clínicos e radiográficos da correção cirúrgica de hálux valgo utilizando quatro técnicas percutâneas escolhidas de acordo com uma classificação radiográfica predefinida.

Métodos Avaliamos prospectivamente 112 pés em 72 pacientes com hálux valgo operado em um período de um ano. A liberação de tecido mole distal (LTMD) percutâneo e o procedimento de Akin (LTMD-Akin) foram realizados em casos leves. Em hálux valgo de leve a moderado com ângulo distal da articulação do metatarso acima de 10°, adicionamos a osteotomia de Reverdin-Isham (RI). Em casos moderados com incongruência articular, realizamos o chevron percutâneo (CHP). Finalmente, uma osteotomia proximal percutânea fixada (OPPF) com um parafuso, semelhante à de Ludloff , foi proposta em casos graves com ângulo intermetatarsal (AIM) acima de 17°. De acordo com esses critérios, foram realizados 26 LTMDs-Akin, 36 CHPs, 35 RIs e 15 OPPFs. O seguimento médio foi de 17,2 meses (12 a 36 meses). A média de idade em operação foi de 58,8 anos (17 a 83 anos), e 89% dos pacientes eram do sexo feminino.

Resultados A média do ângulo de hálux valgo (AHV) pré-operatório e o AIM diminuíram de 21° para 10,2°, e de 11,2° para 10,3°, respectivamente, em casos de LTMD-Akin. Em casos de RI, a média do AHV diminuiu de 26,6° para 13,7°, e o AIM, de 11,2° para 10,3°; em casos de CHP, o AHV médio diminuiu de 31° para 14,5°, o AIM diminuiu de 14,9° para 10,7°, e a OPPF, de 39,2° para 17,7°, e o AIM 11,8° para 6,8°. A média do escore de tornozelo e retropé da American Orthopaedic Foot and Ankle Society (AOFAS) aumentou de 49,2 para 88,6. A taxa de complicação foi de 11%.

Conclusão Nosso protocolo de tratamento não difere muito dos clássicos, com resultados semelhantes. Temos como vantagem menos agressividade aos tecidos moles e melhores resultados cosméticos. Nível de evidência: nível IV, série de casos prospectivos.
Thermocoagulation as a Surgical Approach for the Treatment of Obsessive-Compulsive Disorder in Refractory Patients: Systematic Review
Authors: Chaves Lucas Praxedes , Souza Álef Ribeiro , Silva Ledismar José da , Crivellaro Laura de Lima , Silva Marina Ferreira da
Published: August 2021

Obsessive-compulsive disorder (OCD), a disabling chronic neuropsychiatric disease, entails high economic costs to society and has high morbidity and mortality rates. The first-line treatments for OCD are selective serotonin reuptake inhibitors and cognitive-behavioral therapy. However, this disorder has the highest refractory index to noninvasive treatment. Alternatively, ablative thermocoagulation neurosurgical techniques have shown efficacy and few adverse effects. The present systematic review aimed to identify validated protocols to observe the effectiveness of ablative procedures in the treatment of severe and refractory OCD, as well as their possible adverse effects and benefits. This review supports the effectiveness of ablative methods by presenting them as a safe non-experimental therapeutic option for cases of highly-refractory OCD. Additional relevant findings were the improvement in cognitive function, functional capacity, affective orientation, and quality of life, which contribute to the destigmatization of this surgical technique. Further controlled studies may lead to the individualization of recommendations of targets for ablative thermocoagulation.
Changing Patterns of Commercial Sex Work Amongst Adolescent Girls in Nepal: The Role of Technology
Authors: Ghimire Anita , Samuels Fiona , Mainali Sarmila
Published: August 2021

The introduction of technology, particularly mobile phones, in the mediation of commercial sex work (CSW) has meant that sex work is expanding from traditional venue based (such as through hotels and massage parlors) work to freelance sex work. It has also changed the face-to-face negotiation in commercial sex work to negotiations mediated online or by phone. Apart from a few programmes, interventions largely use establishments as entry points for their programming and are therefore excluding many girls and women who engage in CSW through personal contacts or facilitated by social media. This article is based on a two-year qualitative study in four districts of Nepal, in Delhi (India), and the Indo-Nepal border in eastern Nepal. It gives a short overview of the girls and their life in the adult entertainment sector (AES), which is the main entry point for CSW, and discusses how technology is increasingly used to mediate CSW. Based on our findings, which show that technology is displacing establishment-based CSW in Nepal, we argue that to ensure that we do not leave girls behind, programmes and interventions targeting venues where girls engage in CSW should re-consider their strategies for reaching girls working in the AES.
Crossover between distinct symmetries in solid solutions of rare earth nickelates
Authors: Fowlie Jennifer , Mundet Bernat , Toulouse Constance , Schober Alexander , Guennou Mael , Domínguez Claribel , Gibert Marta , Alexander Duncan T. L. , Kreisel Jens , Triscone Jean-Marc
Published: August 2021

A strong coupling of the lattice to functional properties is observed in many transition metal oxide systems, such as the ABO3 perovskites. In the quest for tailor-made materials, it is essential to be able to control the structural properties of the compound(s) of interest. Here, thin film solid solutions that combine NdNiO3 and LaNiO3, two materials with the perovskite structure but distinct space groups, are analyzed. Raman spectroscopy and scanning transmission electron microscopy are combined in a synergistic approach to fully determine the mechanism of the structural crossover with chemical composition. It is found that the symmetry transition is achieved by phase coexistence in a way that depends on the substrate selected. These results carry implications for analog-tuning of physical properties in future functional materials based on these compounds.
In-plane magnetic field induced helicity dependent photogalvanic effect on the surface states of topological insulators (BixSb1−x)2Te3
Authors: Chen Shenzhong , Yu Jinling , Zhu Kejing , Zeng Xiaolin , Chen Yonghai , Liu Yu , Zhang Yang , Cheng Shuying , He Ke
Published: August 2021

A hallmark signature of the three-dimensional (3D) topological insulator (TI) is that the spin-momentum locked massless Dirac fermions populate its surface states, where the carrier spins are locked to their momentum. Here, we report on the magnetic-field induced helicity dependent photogalvanic effect (MHPGE) of 3D TI thin films Bi2Te3 or (BixSb1−x)2Te3 of different thicknesses excited by near-infrared (1064 nm) under an in-plane magnetic field. It is found that the MHPGE current Jcx under the longitudinal geometry, i.e., Jcx∥Bx, is induced by the Larmor procession, while that under the transverse geometry, i.e., Jcx∥By, is mainly introduced by the hexagonal warping, which can be enhanced by the in-plane magnetic field. Our work demonstrates the possibility to tune the spin-polarized photocurrent of the surface states in 3D TIs via a magnetic field, which may be utilized to design new kinds of opto-spintronic devices.
Piezocatalysis in ferroelectric Ba0.85Ca0.15Zr0.1Ti0.9O3/polyvinylidene difluoride (PVDF) composite film
Authors: Sharma Moolchand , Singh Gurpreet , Vaish Rahul
Published: August 2021

The ferroelectric Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZTO) ceramic particles were immobilized in a polymer matrix of polyvinylidene difluoride (PVDF) in order to fabricate flexible and stable composite films for the treatment of water using the piezocatalysis process. The content of BCZTO in BCZTO/PVDF composite films was 0, 5, and 10 wt. % of PVDF. The presence of the BCZTO phase in PVDF composites was confirmed using x-ray diffraction, Raman spectroscopy, and a scanning electron microscope. Piezocatalytic activity of BCZTO/PVDF composite films was investigated by monitoring the degradation of various organic dyes, pharmaceuticals, and bacteria present in the water. The highest values of dye degradation were achieved in 10 wt. % BCZTO/PVDF composite films, where the model dyes named methylene blue, Rhodamine B, and methyl orange dyes were degraded by ∼91%, ∼86%, and 90% after the sonication for 180 min, respectively. The dye degradation performance using piezocatalysis was found to be repeatable and consistent for up to five cycles. Hydroxyl radical (⋅OH) was identified to be the main reactive species behind piezocatalytic dye degradation. An increment in dye degradation performance was observed with an increment in the power of the ultrasonicator during piezocatalysis. In addition, 10 wt. % BCZTO/PVDF composite films displayed 59% and 50% degradation of pharmaceutical antibiotics named tetracycline and ciprofloxacin, respectively, within 180 min of sonication, respectively. Also, more than 99.99% E. coli bacteria were inactivated using 10 wt. % BCZTO/PVDF composite films under 180 min of sonication treatment and showed a bacterial log reduction of 3.4. These promising results indicate the 10 wt. % BCZTO/PVDF composite film as a potential candidate for the treatment of water using piezocatalysis technology.
Magnetization dynamics of single and trilayer permalloy nanodots
Authors: Kuchibhotla Mahathi , Talapatra Abhishek , Haldar Arabinda , Adeyeye Adekunle Olusola
Published: August 2021

We have investigated the magnetization dynamics in single and trilayer circular permalloy nanodots with a diameter of 120 nm using broadband ferromagnetic resonance spectroscopy. For single-layer nanodots, two well-separated modes near the saturation field, a high-frequency center mode due to excitations at the center of the nanodots and a low-frequency edge mode due to the inhomogeneous effective field near the edges, were observed. Both the center mode and the edge mode are found to be sensitive to the thickness of the nanodots. However, for trilayer nanodots, two center modes arise due to the in-phase and out-of-phase precession of spins in magneto-dynamically coupled layers. Our experimental results are substantiated by micromagnetic simulations, which are in good agreement.
Genetic and molecular characterisation of subtropically adapted low-phytate genotypes for utilisation in mineral biofortification of maize (
Authors: Ragi Shridhar , Muthusamy Vignesh , Zunjare Rajkumar U. , Bhatt Vinay , Katral Ashvinkumar , Abhijith Krishnan P. , Kasana Ravindra , Gain Nisrita , Sekhar Javaji C. , Yadava Devendra K. , Hossain Firoz
Published: August 2021

Phytic acid (PA) is a major anti-nutritional factor in maize grains and significantly reduces the bioavailability of minerals such as iron and zinc in humans. Reduction of PA in maize (Zea mays L.) thus assumes great significance. Despite the availability of low phytic-acid (lpa) mutants in maize, their utilisation in breeding has been limited because of non-availability of well adapted lpa-based inbreds. A set of 24 subtropically adapted lpa1-1-based maize inbreds derived through molecular breeding was evaluated along with seven wild-type inbreds at multilocation. The lpa1-1 inbreds possessed 35.8% lower PA (1.68 mg/g) than the wild-type inbreds (2.61 mg/g). Mean proportion of PA was lower in the lpa1-1-based inbreds (62.8%) than in the wild-type inbreds (91.6%). The lpa1-1 inbreds showed similar performance for plant- and ear-height besides flowering behaviour as did wild types. Average grain yield among lpa1-1 inbreds (2735.9 kg/ha) was at par with the original versions (2907.3 kg/ha). Molecular profiling of these lpa1-1 inbreds using 60 genome-wide single-sequence repeats generated 172 alleles, with a mean of 2.87 alleles per locus. Mean polymorphism information content and mean gene diversity were 0.41 and 0.48 respectively. Genetic dissimilarity ranged from 0.23 to 0.81, with an average of 0.64. Cluster analyses grouped 24 lpa1-1 genotypes into three major clusters, and principal-coordinate analysis depicted the diverse nature of genotypes. The study also identified a set of potential hybrid combinations with low PA for their direct utilisation in biofortification program. This is the first study on comprehensive characterisation of lpa1-1-based inbreds adapted to subtropical conditions.
Fitting the standard genetic code into its triplet table
Authors: Yarus Michael
Published: August 2021

Significance

The standard genetic code (SGC) is common to all sufficiently explored Earth biota, suggesting a common origin for protein biosynthesis in every known organism. The ancient events leading to this near-universal biological characteristic are manifestly of scientific importance. The accompanying text presents a detailed pathway for formation of the SGC, as well as a method for identifying essential origin events. Significantly, the SGC can evolve using only well-characterized chemical, biochemical, and physical mechanisms, paralleling other known evolutionary transitions.
Ventral pallidum regulates the default mode network, controlling transitions between internally and externally guided behavior
Authors: Klaassen Arndt-Lukas , Heiniger Anne , Vaca Sánchez Pilar , Harvey Michael A. , Rainer Gregor
Published: August 2021

Significance

Many routine, inwardly focused behaviors require little attention and can be carried out automatically. However, environmental changes can necessitate a modification of routine behaviors, and this requires external focus. The default mode network (DMN) becomes active during the performance of routine tasks and is deactivated during new learning. Using an optogenetic approach, we show that activation of the ventral pallidum (VP), a subcortical node of the DMN, keeps animals in an inwardly focused state, severely compromising new learning. Conversely, VP inactivation allows escape from automatized behavior, conferring a learning advantage. We suggest that the VP plays a critical role in global brain state transitions between periods of outward focus and DMN states favoring behaviors reliant on learned internal schemata.
MicroED structure of the human adenosine receptor determined from a single nanocrystal in LCP
Authors: Martynowycz Michael W. , Shiriaeva Anna , Ge Xuanrui , Hattne Johan , Nannenga Brent L. , Cherezov Vadim , Gonen Tamir
Published: August 2021

Significance

Microcrystal electron diffraction (MicroED) is a cryogenic electron microscopy (cryo-EM) method that determines protein structures from submicron crystals. G protein–coupled receptors (GPCRs) are membrane proteins that are critically important drug targets. These proteins require crystallization in lipidic cubic phase (LCP), making standard MicroED approaches intractable for investigating these samples. Here, we show that GPCR microcrystals grown in an LCP can be made amenable for MicroED by converting the LCP to the sponge phase and then ion-beam milling the crystals into thin lamellae. Our findings provide the basis for solving GPCR structures using MicroED, with future applications in structure-based drug discovery.
Development properties of aluminum matrix composites reinforced by particles of boron carbide
Authors: Alattar A L , Yu Bazhin V
Published: August 2021

Composite materials are an important class of economical structural materials with unique properties that expand the scope of mechanical engineering in various industries. One of the most interesting metal composite materials is metal structures with low cost of reinforcement and availability for mass production. Due to the development of the structural requirements of some aircraft components, the development of the accelerated aging process becomes necessary to observe and understand the aging of aluminum alloys and predict the effect of this process on the mechanical behaviors of these alloys under temperature. In this research boron carbide (B4C) is reinforced in the aluminum matrix composites to increase the more conductivity and characterized for their mechanical properties such as hardness and tensile strength. Al-5%Cu aluminum alloy metal matrix composites will be reinforced with Boron Carbide (B4C) particles up to 2, 5 and 7 % was produced by stir casting. Particulates may subsequently add using the squeeze casting process. The squeeze casting technique decreased the porosity of the final composites. The modes of aging of MMC reinforced with B4C particles are determined. It is shown that when aging at 225 °C with an increase in the content of B4C particles to 7%, the maximum hardness is reached after 7 hours, while in the matrix alloy after 9 hours. Aging at 250 °C reduces the time to reach maximum hardness by 1 hour.
Development and evaluation of the efficiency of using biopolymers of the low-density polyethylene/natural rubber composition for the production of products with a short service life, taking into account the requirements of the “Green economy”
Authors: Varyan I. A. , Bobkov A. L. , Kolesnikova N.N.
Published: August 2021

Abstracts

The authors consider the use of biopolymers of low-density polyethylene and natural rubber composition for the production of products with their short service life based on the developed formulation and production technology. In this study several compositions of biopolymers of the proposed formulation there are considered their physical and chemical properties, and the efficiency of using such biopolymers is calculated considering the characteristics of their biodegradation. It is shown that biopolymers of the PE/NR composition with natural rubber content of at least 40% have acceptable biodegradation characteristics. The authors performed calculations to evaluate the efficiency of production of biopolymers of low-density polyethylene and natural rubber compositions, which showed high investment attractiveness of such projects.
Methods for experimental research of carbon fiber reinforced plastics with damages for fan blades
Authors: Palchikov D S
Published: August 2021

Annotation

The paper is devoted to the methods of experimental studies of carbon fiber reinforced plastics strength with damage of various categories. The first part of the work is devoted to the analysis of the existing damage classification for aircraft parts made of polymer composite material, as well as the development of a quasi-static punching method for their application to carbon fiber samples. In the second part of the work, experimental studies of the residual tensile strength of carbon fiber T144 with damages of various categories are presented. The dependence of the residual tensile strength on the punching energy is obtained. Based on the obtained data and recommendations of the FAA, the permissible levels of tensile stresses for carbon fiber T144 were 529 MPa, which is two times higher than the calculated level of the CIAM fan blade model tensile stresses from this material in the operating mode. The reported study was funded by RFBR according to the research project No. 18-29-18071\18.
Energy-efficient furnace for basalt fiber production
Authors: Strogonov K V
Published: August 2021

Annotation

In recent years, the production of products made of composite materials based on carbon fiber, glass fiber, and basalt fiber has been developing. Composite products based on continuous basalt fiber are becoming more and more widespread, since basalt is practically an inexhaustible raw material and is actually prepared by nature for use. This article suggests the design of a melting furnace, since the melting process is the most energy-intensive in the production of fiber. The article provides a list of heat engineering principles necessary for creating an energy-efficient furnace, such as the maximum heating of basalt by waste gases, Gorenje fuel directly in the basalt melt and the organization of the melt barbatage, heating of the gas-air mixture and the use of vacuum in the melt clarification zone. This paper presents the results of a demonstration study on physical models showing the operation of the bubbling layer, the saturation of the melt with gas bubbles, and the process of removing visible gas inclusions. The final part of the article presents the results of evaluating the performance and energy costs in the developed furnace.
Synthesis and properties of reactive oligoketones
Authors: Kharaev A M , Ch Bazheva R , Bazhev A Z , Inarkieva Z I , Martazanova R M , Barokova E B
Published: August 2021

Oligoketones based on 1,1-dichloro-2,2-di (4-hydroxyphenyl) ethylene and 4,4′-dichlorodiphenyl ketone were synthesized by the method of high-temperature polycondensation under the reaction of nucleophilic substitution; 1,1-dichloro-2,2-di (3,5-dibromo-4-hydroxyphenyl) ethylene and 4,4′-dichlorodiphenyl ketone of varying degrees of polycondensation. Oligoketones have been obtained containing reactive end phenolate groups, which readily enter into polycondensation reactions to form various copolymers. The composition and structure, as well as the conditions for the synthesis of these oligoketones were investigated. The formation of oligomers of a given structure has been confirmed by IR spectroscopy, elemental analysis, and X-ray structural analysis.
Copolyesters based on 3,5-dibrom-4-hydroxybenzoic acid chloranhydride
Authors: Kharaev A M , Ch Bazheva R , Kh Sultigova Z , Inarkieva Z I , Martazanova R M , Yu Khochuev I , Kharaeva R A
Published: August 2021

Modified copolyesters using 3,5-dibromo-4-hydroxybenzoic acid chloride have been synthesized by the method of low-temperature polycondensation (acceptor-catalytic polycondensation). The main laws governing the synthesis of copolyesters have been studied. It was found that the presence of bromine atoms reduces the reactivity of the hydroxyl group due to the steric effect, as well as due to the possible formation of a weak hydrogen bond between the bromine and hydrogen atoms of the hydroxyl group. The main physical and mechanical characteristics of the synthesized copolyesters have been investigated. Copolyesters are heat- and fire-resistant high-strength polymers that can be used in various industries as non-combustible heat-resistant structural polymer materials.
Polyarylene ether ketone copolymers and their primary properties
Authors: Storoszhuk I P , Kallinnikov A N , Borodulin A S , Pavlukovich N G , Alekseev V M
Published: August 2021

Abstracts

Amorphous soluble thermoplastic polyarylene ether ketone copolymers based on mixtures of bisphenols and benzophenone dihalides with glass transition temperature of 190-240°C were synthesized, and are considered to be promising as a polymer matrix for thermoplastic prepregs reinforced with carbon and glass fibers.
Testing and selection of counterbody material for operating in abrasive conditions
Authors: Matveeva V A , Kozlova Y S , Razumova S N , Plokhikh A I
Published: August 2021

Abstracts

Materials that can serve as a substitute for hard tissues of a human tooth in abrasion tests of toothbrushes were reviewed. The microstructure of hard dental tissues was studied using a light microscope. Microhardness was measured on slices of the intact third molars and the outer surface of the incisors. It was established that the selection of the counterbody material in tribological tests of toothbrushes was reduced to the search for a tooth enamel analog.
Influence of a mixture of calcium and zinc stearates on the thermal and mechanical properties of PVC plastic
Authors: Borukaev T A , Kharaev A M , Kh Shaov A , Kh Salamov A , Borodulin A S
Published: August 2021

A complex stabilizer based on a mixture of calcium and zinc stearates was developed, which was used to replace the tribasic lead sulphate in the formulation of cable polyvinyl chloride plasticate. The influence of a complex stabilizer on the basic physical and mechanical properties of cable polyvinyl chloride plasticate is investigated. It was found that the use of a complex stabilizer in the formulation of cable polyvinyl chloride plasticate does not lead to a decrease in the thermal, technological and operational characteristics of the material. It is shown that the thermal properties of the cable compound containing a complex stabilizer remains at the level of the original plastic. This is due to the ability of the complex stabilizer to effectively bind hydrogen chloride released during the destruction of the polymer matrix. It is established that the cable polyvinyl chloride plasticate containing in the formulation of a complex stabilizer in its mechanical characteristics is not inferior to the industrial compound, and in some respects surpasses it.
Advances in tailored fiber placement technology
Authors: Khodunov A A , Bogachev V V , Borodulin A S
Published: August 2021

The article presents an overview of the world trends in the development of the tailored fiber placement technology (TFP), which allows to obtain volume-reinforced preforms for layered composites with increased physical and mechanical properties. Primary factors hindering the large-scale implementation of the TFP process in mass production are identified. The main achievements and capabilities of the technology are presented and promising research directions for its further development are proposed.
Research of transversal properties of winding basalt plastics based on basalt fiber with experimental lubricants
Authors: Shakirov K M , Sokolov G S , Nelyub V A
Published: August 2021

This article presents the results of a study of the shear strength dependence of basalt plastics on the chemical nature and composition of the developed lubricants for continuous basalt fiber. It is shown that the recipe of lubricants has a significant effect on the shear strength of basalt plastics. It is mentioned that by purposefully selecting and varying the components of the lubricants, it is possible to achieve a significant increase in the shear strength, which is an important factor for basalt plastics for structural purposes.
Cylindrical bending of transversely isotropic composite panels with finite strains
Authors: Dimitrienko Yu I , Gubareva E A , Karimov S B , Yu Kolzhanova D
Published: August 2021

Abstracts

The article is devoted to solving the problem of cylindrical bending of a flat panel made of a transversely isotropic incompressible composite material with finite deformations. The focus of the article is that in this problem the so-called universal model of constitutive relations is considered, which allows one to obtain solutions to problems simultaneously for several classes of models related to different conjugate pairs of stress-strain tensors. This method was proposed earlier in the works of Yu.I. Dimitrienko. Using this method, the difference in the calculation results, which are obtained using various models of composites with finite strains, is shown.
Modeling Fatigue Damage Accumulation in Power Engine Structures
Authors: Dimitrienko Yu I , Yurin Yu V , Prozorovskiy A A
Published: August 2021

Abstracts

The article describes the development of a new design technology for power engine structures (PES) hulls of increased reliability, based on the methods of system analysis using computer modeling of damage accumulation in structural elements, as well as the development of technical solutions for creating the PES hull design using new heat-resistant composite carbon-carbon and carbon-ceramic materials. To calculate the accumulation of damage, the chemical criteria of durable strength is used, for numerical calculation of the stress-strain state of structures taking into account creep, an iterative method for solving a three-dimensional problem of thermomechanics using the finite element method is applied. An example of the calculation of a high-pressure structural element, performed in the work, showed the possibility of practical implementation of the proposed technique and its effectiveness, in terms of reducing or replacing experimental studies to substantiate the reliability of structures.
Numerical modelling in problems of thermal control for three-layer structures with defects
Authors: Dimitrienko Yu I , Krasnov I K , Salnikova A A , Yurin Yu V
Published: August 2021

This article describes solutions to the direct and inverse problems of the three-dimensional non-stationary heat conduction problem in a three-layer structure, using the finite element method for the direct problem and the gradient descent method for the inverse problem. A comparison of the FEM-solution and the analytical solution for a solid with a simple geometry is presented. Here are presented solutions of the direct and inverse three-dimensional non-stationary heat conductivity problem for a free three-stage turbine. The accuracy of the found and exact solutions is compared.
Determination of models constants for thermomechanical properties of composites based on experimental data analysis
Authors: Dimitrienko Yu I , Gumirgaliev T R , Epishkina A
Published: August 2021

Annotation

This article presents an algorithm for finding the constants in the model of changing the thermoelastic properties of polymer composites. The calculation of the constants is based on the processing of the experimentally obtained data. Optimization methods are applied to minimize the discrepancy between the experimental data and the analytical dependence on the constants that need to be found. Also, a method was proposed for determining the constants in the model of density change during destruction. The paper analyzes the effect of high temperatures on the change in density and elastic modulus of composite materials. On the basis of this, an algorithm was constructed for calculating the change in elastic properties up to temperatures of thermal destruction and during thermal destruction. The error between theoretical modeling and experimental data did not exceed 5%.
Assembly of metal-composite compounds by magnetic pulse processing
Authors: Yu Astapov V
Published: August 2021

The increasingly widespread use of composite parts in the industry also requires a special approach to the connections between composite and metal parts. One of these methods of forming permanent joints is magnetic pulse processing, which allows forming joints by acting on a metal part and pressing it on another composite one. Calculated the main electrical parameters of the magnetic pulse forming technology has been developed for manufacturing individual elements and assembly of the application structure, following the device structure is assembled.
Obtaining electrically conductive wear-resistant coatings using cold gas-dynamic spraying method
Authors: Yu Geraschenkova E , Markov M A , Gerashenkov D A , Farmakovsky B V , Kravchenko I N , Yu Bystrov R , Bykova A D
Published: August 2021

This work presents research results of the technology development in applying electroconductive wear-resistant coatings using supersonic cold gas-dynamic spraying method.
Protective properties of oil compositions modified with Cortec VpCI-369
Authors: Knyazeva L G , Tsynagkova L E , Dorokhov A V , Kuriato N A
Published: August 2021

This paper investigated the effectiveness of anticorrosive protection of a number of metals by means of compositions based on petroleum oils modified with the Cortec VpCI-369 composition (Cortec Corporation, USA). The work of adhesion of the studied compositions and their wetting with water were determined. The contributions of individual components of the protective system to the total effectiveness in a chloride solution are estimated using the method of polarization resistance. Oil compositions with Cortec VpCI-369 (3-10 wt.%) show high protective efficiency when applied to structural carbon steel tested in a thermal moisture chamber (98-100%) and under normal conditions (86-96%). In a chloride-containing neutral solution with an exposure time of 456 h, these compositions are effective against the effect of copper and brass.
The stress-strain state evaluation of elementary carbon fibers with metal coatings
Authors: Nelyub V A
Published: August 2021

The results of the stress-strain state study of carbon fibers with applied metal coatings are presented. The Siemens NX PLM software package Parasolid module has been used for the model construction and calculations. It has been assumed that only normal Mises stresses occur in an elementary carbon fiber with a metal coating. The titanium, stainless steel and copper have been used as coating materials. The calculations have been carried out for each type of coating with a change in thickness from 50 to 200 nm. It has been found that the displacement minimum values occur for carbon fiber coated with stainless steel, and there is a decrease in the amount of displacements and stresses with an increase in the metal coating thickness.
Investigation of properties of elementary carbon fibers with different technologies for preparing their surfaces before metallization
Authors: Nelyub V , Fedorov S , Klimovich Yu
Published: August 2021

This paper presents the results of tensile tests of elementary carbon fibers used to make unidirectional carbon tapes LU-P/0,2 and FibArmTape 230/300 and grade GG1200T and GG200T carbon fabric before and after the activation process that precedes the depositing of metal coatings. For activation of carbon tapes and fabrics, two low-temperature plasma units, one pulse unit, and one magnetron sputtering unit were used. The magnetron sputtering unit allowed fibers’ activation before metallization. The influence of activation duration and the type of apparatus for preprocessing on the mechanical strength of carbon fibers was investigated.
Prediction of hardness distribution during SPD process based on FEM simulations: case study of ECAP and HPT processes
Authors: Abd El Aal Mohamed Ibrahim
Published: August 2021

3D finite element method (3D FEM) simulations of equal channel angular pressing (ECAP) and high-pressure torsion (HPT) of Al6061-T6 alloy were carried out and analyzed. 3D FEM results were correlated and compared with those obtained experimentally and theoretically through different mathematical equations. Furthermore, the hardness was estimated using the FEM strain and theoretical strain. The simulations and experimental results were in high conformity with each other. The ECAP load−displacement curves, the HPT load-time curves, and peak loads of FEM and experimental results were close to each other. FEM simulations provided clear strain distribution maps in different planes that fully explain the plastic deformation characteristics and homogeneity in the ECAP and HPT processes. FEM effective strain results have high reliability with a slight deviation from those theoretically estimated through the mathematical equations. The hardness distribution and the strain contours maps were in good agreement, confirming the quality of the FEM results. Hardness values calculated based on FEM effective strain indicate a deviation range of 0.96%–8.8% from experimental results that support the reliability of the FEM results. Microstructure results support hardness increase because of the effect of the grain refinement after ECAP and HPT processing.
Animal Studies and the Early Modern Period
Authors: Mennell Nicole
Published: August 2021

The burgeoning field of animal studies has facilitated the exploration of human-animal relations across a variety of disciplines. Following the animal turn in humanities scholarship, a number of studies published in the late 20th and early 21st centuries have demonstrated that animals reflected the social, cultural, and political concerns of the early modern period in a unique manner due to a shift in the ways in which animals were viewed and valued. This shift was largely caused by the increasing commodification of animals, the discovery of new creatures through global exploration, a renewed interest in investigating and documenting all earthly beings, and an enhanced concern for animal welfare. A range of early modern texts reflect this shift in the perception of animals through engaged interaction with conceptions of the human-animal divide and interrogation of human exceptionalism. Animals also inhabit a multitude of early modern texts in a less prominent manner because, as is the case in the modern world, animals lived alongside humans and were a fundamental part of everyday life. While these texts may not at first seem to reveal much detail about the lives of animals and how they were viewed in the early modern period, the field of animal studies has provided a method of bringing nonhuman beings to the fore. When analyzing the representation of nonhuman beings in early modern texts through the lens of animal studies a thorough consideration of the context in which such texts were written and investigation of the lived experience of the animals they seek to portray is required in order to capture, what leading animal studies scholar Erica Fudge terms, a holistic history of animals.
Form and History in Modern Arabic Poetics
Authors: Fakhreddine Huda
Published: August 2021

Modern Arabic poetic forms developed in conversation with the rich Arabic poetic tradition, on one hand, and the Western literary traditions, primarily English and French, on the other. In light of the drastic social and political changes that swept the Arab world in the first half of the 20th century, Western influences often appear in the scholarship on the period to be more prevalent and operative in the rise of the modernist movement. Nevertheless, one of the fundamental forces that drove the movement from its early phases is its urgent preoccupation with the Arabic poetic heritage and its investment in forging a new relationship with the literary past. The history of poetic forms in the first half of the 20th century reveals much about the dynamics between margin and center, old and new, commitment and escapism, autochthonous and outside imperatives. Arabic poetry in the 20th century reflects the political and social upheavals in Arab life. The poetic forms which emerged between the late 1940s and early 1960s presented themselves as aesthetically and ideologically revolutionary. The modernist poets were committed to a project of change in the poem and beyond. Developments from the qas̩īdah of the late 19th century to the prose poem of the 1960s and the notion of writing (kitābah) after that suggest an increased loosening or abandoning of formal restrictions. However, the contending poetic proposals, from the most formal to the most experimental, all continue to coexist in the Arabic poetic landscape in the 21st century. The tensions and negotiations between them are what often lead to the most creative poetic breakthroughs.
Plants and Literature
Authors: McHugh Susan
Published: August 2021

In countless ways, plants have been in literature from the start. They literally provide surfaces and tools of inscription, as well as figuratively inspire a diverse body of writing that ranges from documenting changing social and ecological conditions to probing the limits of the human imagination. The dependence of human along with all other life on vegetal bodies assures their omnipresence in literatures across all periods and cultures, positioning them as ready reference points for metaphors, similes, and other creative devices. As comestibles, landscape features, home décor, and of course paper, plants appear in the pages of virtually every literary text. But depictions of botanical life in action often prove portentous, particularly when they remind readers that plants move in mysterious ways. At the frontiers of ancient and medieval European settlements, the plant communities of forests served as vital sources of material and imaginative sustenance. Consequently, early modern literature registers widespread deforestation of these alluring and dangerous borderlands as threats to economic and social along with ecological flourishing, a pattern repeated through the literatures of settler colonialism. Although appearing in the earliest of literatures, appreciation for the ways in which plants inscribe stories of their own lives remains a minor theme, although with accelerating climate change an increasingly urgent one. Myths and legends of hybrid plant-men, trees of life, and man-eating plants are among the many sources informing key challenges to representing plants in modern and contemporary literature, most obviously in popular genre fictions like mystery, horror, and science fiction (sf). Further enlightening these developments are studies that reveal how botanical writing emerges as a site of struggle from the early modern period, deeply entrenched in attempts to systematize and regulate species in tandem with other differences. The scientific triumph of the Linnaean “sexual system” bears a mixed legacy in feminist plant writing, complicated further by Black, Indigenous, and People of Color (BIPOC) writers’ creative engagements with the unevenly felt consequences of professionalized plant science. Empowered by critical plant studies, an interdisciplinary formation that rises to the ethical challenges of emergent scientific affirmations of vegetal sentience, literature and literary criticism are reexamining these histories and modeling alternatives. In the early 21st century with less than a fraction of 1 percent of the remaining old growth under conservation protection worldwide, plants appear as never before in fragile and contested communal terrains, overshadowed by people and other animals, all of whose existence depends on ongoing botanical adaptation.