bluuebunny/crossref_metadata_2025 huggingface dataset:
Encapsulating Rifampicin into SLNs: A Viable Option for Managing its Bioavailability Issues Upon Co-Delivery with Isoniazid
Authors: Singh Harinder , Sood Ruchi , Chaira Tridib , Khanna Alka , Upadhaya Dilip J , Bambal Ramesh , Bhatnagar Pradip K. , Singh Mandeep , Kaur Indu Pal
Published: February 2020

Background:

Rifampicin is known to degrade at the acidic pH of the stomach, especially in
the presence of isoniazid. Although isoniazid also degrades partially, its degradation is reversible.

Objective:

Presently, we provide a proof of the fact that the simultaneous oral administration of rifampicin
(RIF), upon incorporation into solid lipid nanoparticles (RIF-SLNs), with isoniazid (INH) overcomes
its INH-induced degradation and improves its oral bioavailability in rats.

Methods:

Solid lipid nanoparticles of RIF (RIF-SLNs) were prepared using a novel and patented
method. The effect of INH was investigated on in vivo bioavailability of RIF both in its free and encapsulated
(RIF-SLNs) form, after oral administration to rats.

Results:

Cmax and AUC0-∞ of RIF increased 158 % and 125 %, respectively, upon incorporation into
SLNs versus free RIF when combined with INH. The Tmax decreased from 5.67 h to 3.3 h, and the
plasma concentration of RIF remained above its MIC (8 μg/ml) at all the tested time points starting with
15 min, when administered as RIF-SLNs in combination with INH.

Conclusions:

The results confirm the scope of combining RIF-SLNs with INH to overcome the bioavailability
of free RIF when combined with INH, especially in fixed dose combinations.
Cardiovascular Effects of Metabolic Surgery on Type 2 Diabetes
Authors: Damaskos Christos , Litos Alexandros , Dimitroulis Dimitrios , Antoniou Efstathios A. , Mantas Dimitrios , Kontzoglou Konstantinos , Garmpis Nikolaos
Published: February 2020

Introduction:

Cardiovascular, together with renal disease, claims a significant proportion of morbidity and mortality in association with type 2 diabetes mellitus (T2DM) and obesity. To improve the long-term renal and cardiovascular outcome, there is the incorporation of bariatric surgery (BS), which seems to be a pivotal intervention.

Areas explored:

Cohort studies and randomized controlled trial (RCT) research of BS among patients with T2DM, were conducted by screening, and then information on renal effects and the cardiovascular outcome was gathered. Metabolic surgery (MS) and BS reduce both mortality and the risk of cardiovascular disorder, chronic kidney diseases and albuminuria. MS refers to a surgical approach, the primary intent of which is the control of metabolic alterations/hyperglycemia in contrast to BS which is a mere weight-reduction therapy. Patients suffering from poor glycaemic control and other macro and micro-vascular diseases will benefit from a surgical approach. The approach implicates hypertension glomerular remission, gut microbiota shift, reduced renal inflammation and fewer instances of chronic cardiac remodelling.

Conclusion:

MS is beneficial where the main aim is to attain significant and long-lasting weight loss results. The RCTs have depicted the superiority which surgical mechanisms hold over medically- based therapy, for enhancing glycaemic control, and achieving remission of diabetes. This type of surgery improves life quality, reduces incidences of other obesity and diabetes related diseases like microvascular disases, sleep apnea, fatal disorder, and fatty liver disease.
Synthesis of Kraton/Polyaniline Ionomer Composite Membrane as Cu (II) Ion Selective Membrane Electrode
Authors: Ahamed Mohd I. , Shakeel Nimra , Anwar Naushad , Lutfullah  , Khan Anish
Published: February 2020

Background:

Kraton/polyaniline ionomer is synthesized and further characterized by electrochemical
studies to check the redox properties of the material. Ion exchange capacity, proton conductivity,
and selectivity of the synthesized membrane were determined. And found that the membrane
was selective for Cu (II) ions.

Methods:

The dry Kraton membranes were weighed and kept in 25 mL of 10 % prepared aniline solution
in a conical flask for 5, 10, 15, and 20 minutes below 10 0C for socking. The prepared solution
of 30 mL of 0.1 M potassium peroxydisulfate was added in a conical flask at constant stirring below
10 0C for half an hour. Finally, the aluminum foil-covered conical flask was kept in the refrigerator
for 24 h and modified Kraton membranes were weighed again before carrying out further studies.

Results:

The membrane was characterized by some physicochemical methods like SEM, TGA, T-IR,
IEC, proton conductivity and selectivity sorption studies. An ionomeric membrane of Kraton polymer
was developed as reported earlier. Kraton membrane showed the IEC of 1.9 meq·g-1. The FTIR
spectrum of Kraton/PANI film reveals that weight loss up to 400°C may be found because of the
thermal degradation of composite substances.

Conclusion:

Ion-selective potentiometric was carried out using the self-prepared ion-selective membrane
electrode. The membrane was prepared by solution casting method. The membrane was characterized
by some physicochemical methods like SEM, TGA, T-IR, IEC, proton conductivity and selectivity
sorption studies. On the basis of selectivity studies, the composite material was found selective
for Cu (II) ion. A copper ISME was successfully fabricated using the solution casting method.
The ISME possessed good selectivity, linearity, working pH range, and response time which was also
used as an indicator electrode for the titration of copper using EDTA.
Stroke Following Successful PTMC in a Patient with Severe Mitral Stenosis: A Case Report and Presenting A Simple Stepwise Approach to PTMC-related Stroke
Authors: Namazi Mohammad H. , Khaheshi Isa , Kaveh Alireza , Taherian Fatemeh , Naderian Mohammadreza , Tabary Mohammadreza
Published: February 2020

Stroke following percutaneous trans-septal mitral commissurotomy (PTMC) is an
unusual complication that could significantly affect the quality of life of the patients, particularly
the young and active ones. We present a middle-aged woman who experienced stroke following
PTMC and successfully treated with thrombolytic therapy regarding the potential adverse effects of
this type of therapy. Also, we present a simple novel stepwise clinical approach for PTMC-related
stroke.
Ethnomedicinal Survey of Indigenous Flora for the Management of Cancer in South-Western, Nigeria
Authors: Christy Akanji Olufunke , MacDonald Idu , Oghale Ovuakporie-Uvo
Published: February 2020

Background:

Nigeria as a multi-ethnic and multi-regional nation is blessed with a great diversity of traditional approaches to common diseases of mankind. Thus, ethnomedicinal surveys are key in reconciling long existing therapeutic approaches as bedrocks for drug discovery to ailing diseases of man today.

Objective of Study:

An ethnomedicinal survey was carried out in Ondo, Ekiti, Ogun, Osun
and Oyo States of South-western region of Nigeria where mostly the Yoruba people live; to
identify and document medicinal plants used in the management of cancer.

Methods:

Herbalists, traditional healers, herb sellers, old men and women who have information
regarding the use of herbs either by inheritance or by trainings were questioned with
the help of a well-structured questionnaire. A sample size of 200 respondents was randomly
chosen with the help of their (community) leaders. Data on the local names, methods of
preparation and the plant parts used were collected and analyzed to determine their frequency
of citation, species use value and informant consensus factor (ICF).

Results:

A total of 126 plant species (belonging to 112 genera and119 families) used in the
treatment of 20 types of cancer were identified. Members of the family Fabaceae (10 species)
were the most widely used. It was observed that Bryophyllum pinnatum and Tetrapleura
tetraptera were the most frequently cited species for the treatment of cancer. Analysis revealed
14 plant parts used in the treatment of cancer by the practitioners. Result also showed
that bone and kidney cancers had highest degree of consensus from informants (0.5each).

Conclusion:

Bioassay guided fractionation is required on the most frequently cited plant
species such that adequate information based on ethnomedicinal practice for the treatment of
cancer in South-Western Nigeria can be kept for successive generation. New anti-cancer
herbal medicines may also be discovered to alleviate the suffering of mankind.
Влияние акцепторной примеси бериллия на оптические свойства монокристаллического AlN
Authors: Мохов Е.Н. , Рабчинский M.К. , Нагалюк С.С. , Гафуров М.Р. , Казарова О.П.
Published: February 2020

The effect of high-temperature (T = 1880 ° C) diffusion of beryllium ions on the properties of single-crystal aluminum nitride is investigated. It was shown that postgrowth doping of AlN with beryllium compensates the small silicon donor centers entering the AlN lattice in an uncontrolled manner during growth. It was established that the introduction of Be into the AlN lattice leads to a decrease in the optical absorption of the latter in the visible and ultraviolet ranges. The totality of the results is explained by a shift in the position of the Fermi level, caused by the introduction of the acceptor impurity of beryllium, towards the ceiling of the AlN valence band.
Отражение от боковой грани кристалла PbSb-=SUB=-2-=/SUB=-Te-=SUB=-4-=/SUB=-
Authors: Немов С.А. , Улашкевич Ю.В. , Погумирский М.В. , Степанова О.С.
Published: February 2020

The reflection spectra from the side face of a PbSb2Te4 crystal were measured by room temperature in polarized light in the range 50-4000 cm-1. Significant anisotropy of the crystal is shown in the directions along and across the crystal layers. The revealed spectral features are interpreted by the contribution of plasma oscillations and crystal lattice vibrations. The calculated dielectric function parameters in the framework of the Drude-Lorentz model are consistent with experimental data.
Роль структурных несовершенств графена в резонансном туннелировании через локализованные состояния в h-BN барьере ван-дер-ваальсовых гетероструктур
Authors: Григорьев М.В. , Казарян Д.А. , Вдовин Е.Е. , Ханин Ю.Н. , Морозов С.В. , Новоселов К.С.
Published: February 2020

Investigated resonant tunneling through defect levels in h-BN barrier van der Waals heterostructures. The effect of multiplication of tunnel resonances through these levels was found, due to the influence of a high degree of defectiveness of the structure of the neighboring layer of graphene, created by intentionally processing in plasma. Various mechanisms of such influence are discussed.
Омические контакты к приборным структурам на основе нитрида галлия
Authors: Желаннов А.В. , Ионов А.С. , Селезнев Б.И. , Федоров Д.Г.
Published: February 2020

Studies of the characteristics of ohmic contacts to epitaxial and ion-doped gallium nitride layers based on the Cr/Pt/Au metallization system are presented. The possibility of forming low-resistance contacts without the use of high-temperature treatment is shown.
For AlGaN/GaN-based heterostructures, an improvement in the characteristics of Ti/Al/Ni/Au ohmic contacts using ion implantation through a silicon dioxide has been shown.
Исследование электростатической системы поверхности кристаллов AuNi/GaN диодов Шоттки методом зонда Кельвина атомно-силовой микроскопии
Authors: Торхов Н.А. , Новиков В.А.
Published: February 2020

Abstract Using atomic-force-microscopy investigations of the electrostatic system of the crystal surface of AuNi/ n – n ^+-GaN planar Schottky diodes, it is shown that the electron work function for the surface of metal Schottky contacts depends on their linear size (diameter D ). At D > 120 μm, the work function of the central contact region approaches the work function e φ_Au ≈ 5.40 eV of a continuous metallic gold film. A decrease in the diameter leads to a decrease in the work function to 5.34 eV at D = 120 μm, 5.21 eV at D = 40 μm, 5.18 eV at D = 10 μm, and 5.14 eV at D = 5 μm. The observed decrease in the work function with diameter is related to the increasing influence of the built-in periphery electrostatic field E _ l , which is determined by the area and perimeter of the Schottky contact. The fundamental differences between the thermodynamic and electrostatic systems of TiAlNiAu/ n ^+-GaN ohmic contacts, in contrast to analogous AuNi/ n -GaN Schottky systems, are indicative of the absence of a Schottky barrier in them and the decisive role of the thermionic transport of mobile carriers.
Разработка и исследование туннельных p-i-n-диодов GaAs/AlGaAs для многопереходных преобразователей мощного лазерного излучения
Authors: Калиновский В.С. , Контрош Е.В. , Климко Г.В. , Иванов С.В. , Юферев В.С. , Бер Б.Я. , Казанцев Д.Ю. , Андреев В.М.
Published: February 2020

Fabrication of connecting tunnel diodes with high peak tunnel current density exceeding the short-circuit current density of photoactive p−n junctions is an important task in development of multi-junction III−V photovoltaic converters of high-power optical radiation. Based on the results of a numerical simulation of tunnel diode current−voltage characteristics, a method is suggested for raising the peak tunnel current density by connecting a thin undoped i-type layer with thickness of several nanometers between the degenerate layers of a tunnel diode. The method of molecular-beam epitaxy was used to grow p−i−n GaAs/Al0.2Ga0.8As structures of connecting tunnel diodes with peak tunnel current density of up to 200A/cm2 .
Получение тонких пленок теллурида висмута на полиимидных подложках методом импульсного лазерного осаждения
Authors: Шупенев А.Е. , Коршунов И.С. , Григорьянц А.Г.
Published: February 2020

Abstract The peculiarities of obtaining p -Bi_0.5Sb_1.5Te_3 and n -Bi_2Te_2.7Se_0.3 thin thermoelectric films with a thickness of about 300 nm grown on a polyimide substrate by the pulsed-laser-deposition method are reported. The influence of the growth temperature, pressure and target-to-substrate distance on the film’s thermoelectric properties is investigated. Thermoelectric p - and n -type films exhibit a high Seebeck coefficient of 220 and –200 μV/K and low electrical power factors of 9.7 and 5.0 μW/(cm K^2) respectively due to the relatively high electrical resistances of the films.
Импедансная спектроскопия пористых кремниевых и кремний-углеродных анодов, полученных спеканием
Authors: Ложкина Д.А. , Румянцев А.М. , Астрова Е.В.
Published: February 2020

Dry sintered macroporous Si electrodes for Li-ion batteries are first studied using spectral impedance measurements (EIS). The obtained EIS spectra in the lithiated and delithated state are modeled by an equivalent electrical circuit, the parameters of which make it possible to determine the main stages of the electrochemical process of lithium incorporation / extraction caused by the surface layer of solid-state electrolyte (SEI), a double electric layer, and diffusion in the solid phase of the electrode material. It was shown that the effective diffusion coefficient of Li in Si increases with rising degree of lithiation from D = 6.5·10 ^ (-12) cm2/s to D = 2.6·10^ (-10) cm2/s. The effect of carbonization by sucrose pyrolysis was studied, which led to a decrease in impedance and an increase in the diffusion coefficient of lithium to D = 2.2·10^(-10) - 1.7·10^(-9) cm2/s.
Экспериментально-теоретическое исследование эволюции атомной структуры высокоэнтропийных сплавов на основе Fe, Cr, Ni, Mn и Co при термическом и радиационном старении
Authors: Мешков Е.А. , Новоселов И.И. , Янилкин А.В. , Рогожкин С.В. , Никитин А.А. , Хомич А.А. , Шутов А.С. , Тарасов Б.А. , Данилов С.E. , Арбузов В.Л.
Published: February 2020

The comprehensive experimental and theoretical study of the processes of local ordering of multicomponent alloys was carried out. Experimental techniques included atom-probe tomography and measurement of electrical resistivity during isochronal annealing. The theoretical study was carried out by atomistic modeling methods. The evolution of the system was described in the framework of the multiscale paradigm which is based on quantum-mechanical calculations. The initial stage of the decomposition of a solid solution of CoCrFeNi alloy with the formation of Ni4Cr and Ni2Cr precipitations was demonstrated for the first time by the employed approach.
Сверхтонкие взаимодействия в узлах меди антиферромагнитных соединений, аналогов сверхпроводящих металлооксидов меди
Authors: Теруков Е.И. , Марченко А.В. , Насрединов Ф.С. , Левин А.А. , Лужков А.А. , Серегин П.П.
Published: February 2020

Emission Mössbauer spectra of 61Cu(61Ni) in dielectric metal oxides of divalent copper Ca1−xSrxCuO2, Ca2CuO2Cl2, Sr2CuO2Cl2, YBa2Cu3O7−x, La2−xSrxCuO4 and Nd2−xCexCuO4 correspond to the combined quadrupole and Zeeman interaction of 61Ni nuclei with local fields at the sites of copper. For the superconducting metal oxides, on the other hand, spectra correspond to the interaction of the quadrupole moment of 61Ni nuclei with the electric field gradient. The both groups of metal oxides show linear dependences of the quadrupole interaction constants on the calculated values of the principal components of the lattice electric field gradient tensor at the copper sites for 61Ni nuclei (emission 61Cu(61Ni) Mössbauer spectroscopy data) as well as for 63Cu nuclei (63Cu nuclear magnetic resonance data). This fact is explained by invariable values of the valence component of electric field gradient for both 61Ni2+ and 63Cu2+ probes in all divalent copper metal oxides under investigation.
Намагничивание парамагнитных ионов фазово-модулированными СВЧ-импульсами в нулевом магнитном поле
Authors: Арифуллин М.Р. , Бердинский В.Л.
Published: February 2020

Magnetization of paramagnetic ions with spin S=1 in solid state at zero magnetic field is shown can be created by pulse manipulation of electron spins rather than by external magnetic fields. For this purpose, crossed microwave pulses with different initial phases or pulses of finite duration are proposed. Resonance cases when the frequency of microwave pulses coincides with the frequency of level splitting in the zero field are described. The effect of magnetization pulse creation has some similarities with the alignment-orientation transformation observed in optical experiments.
Интеркаляционный синтез силицидов кобальта под графеном, выращенным на карбиде кремния
Authors: Гребенюк Г.С. , Елисеев И.А. , Лебедев С.П. , Лобанова Е.Ю. , Смирнов Д.А. , Давыдов В.Ю. , Лебедев А.А. , Пронин И.И.
Published: February 2020

Abstract The process of formation of cobalt silicides near the graphene-silicon carbide interface by intercalation of single-layer graphene grown on the 4 H - and 6 H -SiC(0001) polytypes with cobalt and silicon is studied. The experiments were carried out in situ in ultrahigh vacuum. The analysis of the samples is performed by high-energy-resolution photoelectron spectroscopy using synchrotron radiation, low-energy electron diffraction, and also Raman spectroscopy, atomic-force and kelvin-probe microscopies. The thicknesses of the deposited cobalt and silicon layers is varied to 2 nm, and the sample temperature, from room temperature to 1000°C. Co and Si atoms deposited on heated samples is found to penetrate under graphene and are localized between the buffer layer and the substrate, which leads to a transformation of the buffer layer into additional graphene layer. It is shown that the result of intercalation of the system with cobalt and silicon is the formation under two-layer graphene of a Co–Si solid solution and silicide CoSi coated by the surface Co_3Si phase. It is shown that the thickness and the composition of the formed silicide films can be changed by varying the amount of the intercalated material and the order of their depositions.
Энергетический спектр и оптическое поглощение углеродных наносистем на примере изомеров N 11 и 22 фуллерена С-=SUB=-84-=/SUB=-
Authors: Мурзашев А.И.
Published: February 2020

Abstract The energy spectra of isomers nos. 11 and 22 of C_84 fullerene is obtained with allowance for the intrasite Coulomb interaction. Based on the obtained spectra, the optical absorption spectra of these systems are simulated. The obtained optical absorption spectra qualitatively agree well with the available experimental data. In addition, the optical absorption spectra are also calculated on the base of the energy spectra of each of the systems calculated without considering the intrasite Coulomb interaction. The comparison of the results obtained in these different models strongly demonstrates the most important role of the Coulomb interaction in the formation of the electronic and optical properties of these systems.
Полимерные пьезоэлементы на основе пористых пленок поливинилиденфторида и контактных электродных слоев полианилина
Authors: Ельяшевич Г.К. , Курындин И.С. , Розова Е.Ю. , Сапрыкина Н.Н.
Published: February 2020

The preparation method to obtain the new hybrid piezoactive systems by successive layer-by-layer aniline polymerization in situ on the porous polyvinylidene fluoride films formed in the process based on melt extrusion has been elaborated. It is established by IR spectroscopy that the conducting form of polyaniline (emerald salt) is synthesized. It is proved that the samples containing two layers of polyaniline are characterized by higher electroconductivity than the single-layer ones, and its value increases with the orientation degree of the support. It is confirmed by electron microscopy that this effect is due to the higher homogeneity and ordering of the conducting layer in more oriented samples. It is shown that hybrid samples have a higher breaking strength, elastic modulus and break elongation than support. Electro- and piezoactive properties of the hybrid systems were studied by cyclic voltampermetry and piezomodulus testing using polyaniline layers as contact electrode materials. Piezoconstants of the samples were measured depending on the direction of loading.
Стационарные состояния односторонне гидрированных листов графена, расположенных на плоских подложках
Authors: Савин А.В.
Published: February 2020

The stationary states of graphene sheets partially hydrogenated on one side and lying on flat substrates are examined. It is shown that such sheets can have stable flat and various scrolled structures. The maximum density of hydrogenation at which the flat structure remains energetically the most favorable depends monotonously on the value of the adhesion of the sheet with the substrate. The stronger is the energy of interaction with the substrate, the higher is the maximum possible density of sheet hydrogenation. The dimensionless maximum density of hydrogenation is p=0.12 for the substrate with the surface of crystal ice, for graphite p=0.21, for silicon carbide p=0.28 and p=0.48 for nickel. The simulation allows us to conclude that the maximum hydrogenation of a graphene sheet (one hydrogen atom per two carbon atoms) and the production of a graphone sheet from it can be achieved only by placing the sheet on the surface of crystalline nickel.
Геометрический потенциал в гигантских фуллеренах
Authors: Садыков Н.Р. , Юдина Н.В.
Published: February 2020

The motion of electrons in a giant fullerene due to the geometric potential has been investigated in the one-electron approximation. It is shown that the geometric potential due to the bending excitation of curvature causes an additional normal surface force, which affects the mechanism of small-surface oscillations of the giant fullerene. Taking into account the geometric potential for giant fullerenes leads to a decrease or complete compensation of the effect of free transverse (radial) oscillations of the spherical layer.
Фотоэлектрические свойства монокристаллов MnGaInS-=SUB=-4-=/SUB=-
Authors: Нифтиев Н.Н.
Published: February 2020

The spectral distribution of photoconductivity and the temperature dependence of the photocurrent of monocrystals MnGaInS4 are studied. The intrinsic and extrinsic photoconductivities are revealed in the spectrum of photoconductivity. The wavelength range of 0.640–0.760 μm is shown when manganese deficiency in crystals appears and is due to an acceptor defect. The temperature dependence of the band gap in the monocrystals MnGaInS4 is related to the electron – phonon interaction. In the studied temperatures, increase in the photocurrent is associated with the thermal depletion of the attachment levels. The activation energy of the attachment levels is estimated.
Бипланарные эпитаксиальные AlN/SiC/(n,p)SiC-структуры для приборов высокотемпературной функциональной электроники
Authors: Панютин Е.А. , Шарофидинов Ш.Ш. , Орлова Т.А. , Сныткина С.А. , Лебедев А.А.
Published: February 2020

Проведены исследования возможности интеграции эпитаксиальных SiC- и AlN-технологий с использованием противоположных граней общей SiC-подложки (эпитаксия AlN осуществлялась на заключительном этапе) с точки зрения сохранения исходного качества ранее полученных SiC-слоев. В частности, исследовано влияние AlN-гетероэпитаксии и сопутствующих ей упругих напряжений на перераспределение концентрации легирующей примеси в SiC-слоях, а также связанную с этим процессом трансформацию распределения локальных значений напряжения пробоя барьерных диодов. В качестве диагностической процедуры изучения возможных негативных последствий длительного роста (~3 h, ~60 μm) использовались измерения обратных ветвей вольт-амперных характеристик матриц поверхностно-барьерных диодов типа Au-SiC, которые преднамеренно создавались до и непосредственно после проведения процесса AlN-эпитаксии и удалялись после осуществления соответствующего комплекса измерений. Статистическая обработка значений напряжений пробоя, в том числе и вычисление гистограмм, показала, что изменение средних значений и дисперсии как для слоев n-, так и для слоев p-типа оказалось незначительным. Ключевые слова: широкозонные полупроводники, SiC, AlN, высокотемпературная электроника, функциональная электроника.
Получение новых материалов путем сдавливания наночастиц и возбуждения химически связанных с поверхностью атомов
Authors: Орлов А.Н.
Published: February 2020

Показана возможность получения новых материалов за счет протекания туннельных химических реакций на поверхностях сжимаемых наночастиц. Химическая связь поверхностных атомов может быть возбуждена. Для модели были использованы кремниевые наночастицы, покрытые атомами водорода. Туннелирование атомов водорода разных наночастиц навстречу друг другу происходит под ветвями двух пересекающихся" парабол. Был выбран полуклассический подход. Ветви парабол направлены вверх. При сдавлении наночастиц в местах их соприкосновения давление может увеличиваться в сотни и тысячи раз. Свободные связи, появившиеся после отрыва водорода, образуют химические связи между наночастицами. Ключевые слова: наночастицы, химические реакции под давлением, туннельные реакции.
Структурные свойства углеродных пленок, полученных методом ионно-стимулированного импульсно-плазменного осаждения в атмосфере азота
Authors: Завидовский И.А. , Стрелецкий О.А. , Нищак О.Ю. , Савченко Н.Ф. , Дворяк С.В. , Павликов А.В.
Published: February 2020

Carbon films were synthesized by pulse-plasma ion-assisted graphite sputtering in the atmosphere of argon-nitrogen mixture. The samples were studied by Raman spectroscopy, electron diffraction and XPS. According to the obtained data, nitrogen efficiently incorporates into the material structure, which leads to the formation of oriented graphite nanoclusters, which fraction reduces with ion assistance energy increase.
О внутридопплеровской спектроскопии в тонких газовых ячейках при возбуждении атомов широкополосным импульсным излучением
Authors: Измайлов А.Ч.
Published: February 2020

Предложен метод внутридопплеровской спектроскопии, основанный на особенностях сужения с течением времени скоростного распределения оптически возбужденных атомов (молекул) разреженной газовой среды в тонкой ячейке после воздействия достаточно короткого импульса широкополосного излучения. Регистрация узких внутридопплеровских резонансов на центральных частотах квантовых переходов из атомного состояния, возбужденного таким импульсом накачки, осуществляется последующими пробными монохроматическими световыми импульсами. Оптимальные условия для реализации данного метода спектроскопии имеют место, когда время радиационного распада оптически возбужденного атомного уровня превосходит характерное время пролета атомов между стенками рассматриваемой тонкой ячейки, внутренняя толщина которой во много раз меньше ее поперечных размеров. Ключевые слова: внутридопплеровская спектроскопия, тонкая газовая ячейка, широкополосная импульсная накачка, долгоживущие квантовые уровни.
Релятивистский расчёт эффекта отдачи ядра для g-фактора состояния ^2P-=SUB=-3/2-=/SUB=- многозарядных бороподобных ионов
Authors: Малышев А.В. , Глазов Д.А. , Александров И.А. , Тупицын И.И. , Шабаев В.М.
Published: February 2020

The nuclear recoil effect on the $^2 P_{3/2}$-state $g$ factor of B-like ions is calculated to first order in the electron-to-nucleus mass ratio $m/M$ in the range $Z=18$--$92$. The calculations are performed by means of the $1/Z$ perturbation theory. Within the independent-electron approximation, the one- and two-electron recoil contributions are evaluated to all orders in the parameter $\alpha Z$ by employing a fully relativistic approach. The interelectronic-interaction correction of first order in $1/Z$ is treated within the Breit approximation. Higher orders in $1/Z$ are partially taken into account by incorporating the screening potential into the zeroth-order Hamiltonian. The most accurate to date theoretical predictions for the nuclear recoil contribution to the bound-electron $g$ factor are obtained.
Нелинейные поверхностные волны в симметричной трехслойной структуре из оптических сред с различными механизмами формирования нелинейного отклика
Authors: Савотченко С.Е.
Published: February 2020

The propagation of surface TM waves in a three-layer structure, which is a crystal thickness plate with a focusing nonlinearity of a Kerr type, sandwiched between uniaxial photorefractive crystals with a diffusion mechanism for the formation of nonlinearity is considered. Nonlinear surface waves with different attenuation patterns can propagate along the interfaces between the layers. Waves of one type attenuate with distance from the interfaces without oscillations into the depth of the outer layers of photorefractive crystals, and the waves of other type attenuate with oscillations. Wave profiles can have two forms of symmetry about the center of a three-layer structure: symmetric and antisymmetric. The two waves with a symmetric distribution exist with nonperiodic damping and the damping without oscillations. The waves only with antisymmetric distribution exist with nonperiodic damping and the damping without oscillations. The dependences of the propagation constant on the characteristics of the layered structure for the long-wave mode of surface wave propagation are found in an explicit analytical form. The conditions for their existence are indicated.
Соотношения неопределённости числа фотонов и оператора фазы электромагнитного поля для фазовых квантовых суперпозиций когерентных состояний
Authors: Козловский А.В.
Published: February 2020

Проведено исследование различных соотношений неопределённости для фазы (так называемого оператора Пегга-Барнетта) электромагнитного поля и числа фотонов, тригонометрических функций фазы и числа фотонов, а также тригонометрических функций фазы и фазы поля. Рассмотрено электромагнитное поле в квантовых состояниях фазовых суперпозиций когерентных состояний, представляющих собой общие суперпозиции двух когерентных состояний с одинаковыми модулями и произвольными фазами. Рассматриваются и сравниваются между собой жёсткие соотношения неопределённости (неравенство Коши) и мягкие соотношения неопределённости (неравенства Гейзенберга). Ключевые слова: принцип неопределённости, квантовые флуктуации фазы, эрмитов оператор фазы, суперпозиции когерентных состояний.
Экспериментальное и теоретическое исследование спектров фоточувствительности структур с квантовыми ямами-точками In-=SUB=-0.4-=/SUB=-Ga-=SUB=-0.6-=/SUB=-As оптического диапазона 900-1050 nm
Authors: Минтаиров С.А. , Калюжный Н.А. , Максимов М.В. , Надточий А.М. , Харченко А.А. , Шварц М.З. , Жуков А.Е.
Published: February 2020

Investigation of photovoltaic converters based on a novel type of nanostructures referred to as quantum-well dots (QWD) which represents In0.4Ga0.6As layer with pronounced modulation of composition and thickness was carried out. The energies of the optical transitions in QWD were found to be very close light and heavy hole based transitions in the quantum well of similar composition and thickness. QWD ground state peak was found to be strongly TE polarized (>70%), whereas the short-wavelength peak is nearly unpolarized (<10%).
Разрушение эмульсий вода в масле" при воздействии неоднородного переменного электрического поля
Authors: Батыршин Э.С. , Муллаянов А.И. , Саметов С.П.
Published: February 2020

The paper presents an experimental approach using microfluidics methods, optical microscopy and high-speed imaging for studying a destruction of water-in-oil emulsions under a non-uniform alternating electric field. A quantitative estimate of parameters characterizing the emulsion destruction dynamics was made. The method can be used for developing effective techniques for water-in-oil emulsions destruction including combined with other affecting methods: chemical, acoustic, thermal, etc.
Влияние интерфейсных эффектов на электронный спектр структур GaAs/AlGaAs, используемых для создания фотоприемных устройств среднего ИК-диапазона
Authors: Кривобок В.С. , Пашкеев Д.А. , Литвинов Д.А. , Григорьева Л.Н. , Колосов С.А.
Published: February 2020

The effect of transition processes arising in the growth chamber of the molecular beam epitaxy unit on the interfaces structure and electronic spectrum of GaAs /AlxGa1-xAs quantum wells used for MID IR photodetectors was investigated. It is shown that such processes lead to (1) low-frequency shift of the photosensitivity spectrum; (2) reduction of energy shift between the fundamental and first excited hole levels in quantum wells; (3) the appearance of the symmetry forbidden transition in the absorption spectra. These effects provide a simple approach for non-destructive assessment of the interfaces quality in GaAs/AlxGa1-xAs heterostructures for MID IR photodetectors.
Применение корреляционного метода для определения количества вспыхивающих пузырьков и количества фотонов в вспышке при многопузырьковой сонолюминесценции
Authors: Казачек М.В. , Гордейчук Т.В.
Published: February 2020

The number of emitting bubbles and the number of photons given by a single bubble during a flash were estimated with time-correlated single photon counting and combinatorial analysis. MBSL was observed from aqueous NaCl and dodecyl sulfate solutions irradiating with 20 kHz ultrasound. The number of emitting bubbles was defined only like 100, that is, much less than the number of bubbles in the cloud. This can underline the importance of bubble dynamics in flash generation. The number of photons per flash was like 10000, the value was an order of magnitude less than for SBSL.
Применение покрытий AlN для защиты поверхности гетероструктур системы AlGaAs/GaAs от взаимодействия с атмосферным кислородом
Authors: Фомин Е.В. , Бондарев А.Д. , Сошников И.П. , Bercu N.B. , Giraudet L. , Molinari M. , Maurer T. , Пихтин Н.А.
Published: February 2020

The paper presents the results of the synthesis of thin aluminum nitride films by reactive ion-plasma sputtering and the study of their properties with the aim of using as the protective coatings for the high-power AlxGa1-xAs/GaAs semiconductor laser heterostructures. EDS studies and ellipsometry showed that at a residual pressure in the chamber of the order of ~10-5 Torr, a layer of aluminum oxynitride is formed in the films. In this case, the film-substrate heterointerface can undergo oxidation. However, AlN films with a thickness of the order of 100 nm grown in a pure nitrogen medium with a residual pressure of ~10-7 Torr apparently do not contain oxygen, and can reliably prevent its penetration into the heterointerface region. Potentially, they can serve as effective protection for oxidation sensitive heterostructures.
Источник мягкого рентгеновского излучения, формируемый в сверхзвуковых газовых струях аргона под действием высококонтрастных фемтосекундных лазерных импульсов релятивистской интенсивности
Authors: Алхимова М.А. , Рязанцев С.Н. , Скобелев И.Ю. , Мищенко М.Д. , Болдарев А.C. , Jie Feng , Xin Lu , Chen Li-Ming , Пикуз С.А.
Published: February 2020

We investigated the opportunity to create a soft X-ray source in laser-produced plasma without concomitant fast electrons generation.
The x-ray source has been created under the interaction of high-contrast relativistic femtosecond laser pulses with super-sonic Argon jets. Optimal conditions when conversion coefficient to soft x-ray at the range 2.9 – 3.3 keV reached 8.57 ·10^(-5) have been found.
Поведение керамических твердых растворов 33PbYb-=SUB=-1/2-=/SUB=-Nb-=SUB=-1/2-=/SUB=-O-=SUB=-3-=/SUB=--22PbZrO-=SUB=-3-=/SUB=--45PbTiO-=SUB=-3-=/SUB=- в электрическом поле
Authors: Камзина Л.С. , Li G.
Published: February 2020

The temperature dependences of the dielectric parameters were studied, as well as the changes in the dielectric constant with time in ceramic 33PbYb1 / 2Nb1 / 2O3-22PbZrO3-45 PbTiO3 samples in electric fields (0 <E <8 kV / cm). It is shown that in the phase existing below the temperature of the morphotropic phase transition, in addition to the rhombohedral and tetragonal phases, a small fraction of the relaxor pseudocubic phase is present. It was found that, unlike other relaxors, the dielectric constant practically does not change with time when an electric field is applied in the phase below the temperature of the morphotropic phase transition. Possible reasons for this behavior are discussed.
Влияние температуры протонного облучения на характеристики мощных высоковольтных карбид-кремниевых диодов Шоттки
Authors: Козловский В.В. , Корольков O. , Давыдовская К.С. , Лебедев A.А. , Левинштейн М.Е. , Слепчук Н. , Стрельчук А.М. , Toompuu J.
Published: February 2020

For the first time, the effect of irradiation at high temperature (“hot irradiation”) by protons on the capacitance – voltage and current – ​​voltage characteristics of silicon carbide based semiconductor devices was studied. We investigated commercial high-voltage (blocking voltage of 1700 V) integrated 4H-SiC Schottky diodes. Irradiation was carried out by protons with an energy of 15 MeV at temperatures of 20-400 ° C. It has been established that the most sensitive to radiation parameter determining the radiation resistance of devices is the ohmic resistance of the base, which increases monotonically with increasing radiation dose D. It is shown that during “hot” irradiation, the radiation resistance of diodes significantly exceeds the resistance of diodes in low-temperature (“cold”) irradiation . It was concluded that, with increasing irradiation temperature, the rate of formation of deep centers in the upper half of the band gap of silicon carbide decreases.
Gangliosides generalities and role in cancer therapies
Authors: Pasquel-Dávila Daniela S , Yanez-Vaca Sabrina A. , Espinosa-Hidalgo Nicole D , Cuadros Buenaventura Evelin G
Published: February 2020

Gangliosides are located in the plasma membrane; this confers them the ability to interact with other molecules in order to participate in important cellular processes. Some gangliosides presence or absence in the cell surface is associated with either normal condition or pathologies. Particularly in cancer, gangliosides play a critical role in pathological events like cellular malignancy, tumor formation, and metastasis, defining gangliosides as good candidates to be used as cellular markers. When specific gangliosides are exhibited, immunotherapy could be applied in order to inhibit tumorigenesis or induce an immunogenic response. Novel cancer treatments such as NGcGM3/VSSP vaccines, valproic acid, BMS-345541 inhibitor of GD2 and immunotherapies using 1E10 and 14F7 monoclonal antibodies are described. On this review, there will be studied the gangliosides that allowed developing biological techniques that can give immunogenicity to cancer cells
Factors Influencing the Adoption of Health Information Standards in Health Care Organizations: A Systematic Review Based on Best Fit Framework Synthesis
Authors: Han Lu , Liu Jing , Evans Richard , Song Yang , Ma Jingdong
Published: February 2020

Background

Since the early 1970s, health care provision has experienced rapid growth in the investment and adoption of health information technologies (HITs). However, the development and deployment of HITs has often been conducted in silos, at different organizational levels, within different regions, and in various health care settings; this has resulted in their infrastructures often being difficult to manage or integrate. Health information standards (ie, the set norms and requirements that underpin the deployment of HITs in health care settings) are expected to address these issues, yet their adoption remains to be frustratingly low among health care information technology vendors.

Objective

This study aimed to synthesize a comprehensive framework of factors that affect the adoption and deployment of health information standards by health care organizations.

Methods

First, electronic databases, including Web of Science, Scopus, and PubMed, were searched for relevant articles, with the results being exported to the EndNote reference management software. Second, study selection was conducted according to pre-established inclusion and exclusion criteria. Finally, a synthesized best fit framework was created, which integrated a thematic analysis of the included articles.

Results

In total, 35 records were incorporated into the synthesized framework, with 4 dimensions being identified: technology, organization, environment, and interorganizational relationships. The technology dimension included relative advantage, complexity, compatibility, trialability, observability, switching cost, standards uncertainty, and shared business process attributes. The organization dimension included organizational scale, organizational culture, staff resistance to change, staff training, top management support, and organizational readiness. The environment dimension included external pressure, external support, network externality, installed base, and information communication. Finally, the interorganizational relationships dimension included partner trust, partner dependence, relationship commitment, and partner power.

Conclusions

The synthesized framework presented in this paper extends the current understanding of the factors that influence the adoption of health information standards in health care organizations. It provides policy and decision makers with a greater awareness of factors that hinder or facilitate their adoption, enabling better judgement and development of adoption intervention strategies. Furthermore, suggestions for future research are provided.
Improving Adherence to Adjuvant Hormonal Therapy Among Disadvantaged Women Diagnosed with Breast Cancer in South Carolina: Proposal for a Multimethod Study (Preprint)
Authors: Felder Tisha M , Heiney Sue P , Hebert James R , Friedman Daniela B , Elk Ronit , Franco Regina , Gansauer Lucy , Christensen Barbara , Ford Marvella E
Published: February 2020

BACKGROUND

Current clinical guidelines recommend that hormone receptor–positive breast cancer survivors take adjuvant hormonal therapy (AHT) for 5 to 10 years, following the end of definitive treatment. However, fewer than half of patients adhere to the guidelines, and suboptimal adherence to AHT is associated with an increased risk of breast cancer mortality. Research has extensively documented sociodemographic and disease-specific factors associated with adherence to AHT, but very little evidence exists on behavioral factors (eg, knowledge, patient-provider communication) that can be modified and targeted by interventions.

OBJECTIVE

The goal of this study is to develop and test a theory-based, multilevel intervention to improve adherence to AHT among breast cancer survivors from racially and socioeconomically disadvantaged backgrounds (eg, Medicaid-insured). The specific aims are to (1) explore multilevel (eg, patient, health care system) factors that influence adherence to AHT; (2) develop a theory-based, multilevel intervention to improve adherence to AHT; and (3) pilot test and evaluate the intervention developed in Aim 2.

METHODS

For Aim 1, we will recruit breast cancer survivors and health care professionals to participate in semistructured interviews to gain their perspectives about barriers and facilitators to AHT use. We will conduct a directed content analysis of the Aim 1 qualitative interview data. For Aim 2, we will integrate Aim 1 findings and current literature into the design of a multilevel intervention using an Intervention Mapping approach. For Aim 3, we will recruit Medicaid-insured breast cancer survivors to assess the feasibility of the pilot intervention.

RESULTS

From May 2016 to July 2018, we completed interviews with 19 breast cancer survivors and 23 health care professionals in South Carolina. We will conduct a directed content analysis of the qualitative interview data. Results from this analysis will be used, in combination with current literature, to design (Aim 2) and pilot test a theory-based multilevel intervention (Aim 3) in Summer 2021. Results of the pilot are expected for Fall 2021.

CONCLUSIONS

This study will provide a deeper understanding of how to improve adherence to AHT, using a novel and multilevel approach, among socioeconomically disadvantaged breast cancer survivors who often experience disproportionate breast cancer mortality.

INTERNATIONAL REGISTERED REPORT

DERR1-10.2196/17742
Incidental Extra-Colonic Findings in CT Colonography at
Riyadh Region (Preprint)
Authors: Alanazi Muhannad
Published: February 2020

BACKGROUND

Computed tomography colonography (CTC) is a new radiologic technique for examination of the colorectum. The search for, analysis and interpretation of extracolonic findings (ECFs) are a matter of permanent debate and review, given the arguments for and against them.

OBJECTIVE

To assess the prevalence and type of extracolonic findings (ECFs) in a screening population undergoing computed tomography colonography (CTC) in Riyadh region.

METHODS

This retrospective study was conducted in Riyadh region. To achieve the objectives of this study 305 subjects medical records were reviewed, where male represented 55% of participants and female represented only 45%.

RESULTS

About 21% of subjects had any type Extra Colonic Findings (ECFs) where about 74 incidental findings were identified in 65 patients. Out of these findings; 6 patients (9%) required immediate medical attention or urgent imaging/intervention, these included high suspicious of extracolonic malignancy or active infection, 16 patients (25%) required either further imaging and characterization, or follow up imaging, these included undetermined masses or nodules, while 43 patients (66%) required either reassurance or life style modification, which included extensive atherosclerotic changes, fatty liver or spondylolisthesis.

CONCLUSIONS

Colon cancer is one of the leading cause of mortality and morbidity in our Saudi Arabia community. Early detection of colon cancer and its precursor (i.e. polyps) is essential for successful management.