bluuebunny/crossref_metadata_2025 huggingface dataset:
Updates on the Pharmacology of Chloroquine against Coronavirus Disease 2019 (COVID-19): A Perspective on its Use in the General and Geriatric Population
Authors: Yao Xueting , Hou Zhe , Cui Cheng , Zhang Miao , Tu Siqi , Li Haiyan , Liu Dongyang
Published: July 2020

Background:

Chloroquine has been used to treat malaria for more than 70 years. Its safety profile and
cost-effectiveness are well-documented. Scientists have found that chloroquine has in vitro activity against novel
coronavirus (SARS-CoV-2). Currently, chloroquine has been adopted in the Protocol for Managing Coronavirus
Disease 2019 (COVID-19) (Version 7) issued by the China National Health Commission for clinically managing
COVID-19.

Objective:

This review will focus on the antiviral mechanism, effectiveness and safety, dosage and DDIs of
chloroquine, for the purpose of providing evidence-based support for rational use of chloroquine in the treatment of
COVID-19.

Methods:

Use the search terms "chloroquine" linked with "effectiveness", "safety", "mechanism", "drug-drug
interaction (DDIs)" or other terms respectively to search relevant literature through PubMed.

Results:

After searching, we found literature about antivirus mechanism, dosage, DDIs of chloroquine. However,
studies on the effectiveness and safety of chloroquine treatment for COVID-19 for the general and geriatric patients
are not enough.

Conclusion:

According to literature reports, chloroquine has been proven to have anti-SARS-CoV-2 effect in vitro
and the potential mechanism of chloroquine in vivo. Pharmacokinetic characteristics and DDIs study are helpful in
guiding rational drug use in general and geriatric patients. Although there have been reports of successful clinical
application of chloroquine in the treatment COVID-19, more clinical test data are still needed to prove its
effectiveness and safety.
Efficacy of An Aqueous Morinda citrifolia Fruit Extract-Phytosome Gel in Treating Oral Inflammatory Ulcer in Rabbit Model
Authors: Kongpuckdee Sonsawan , Ungphaiboon Suwipa , Sungkharak Supreedee , Phadoongsombut Narubodee , Mahattanadul Sirima
Published: July 2020

Background:

Oral inflammatory ulcers are one of the common complaints of patients attending
out-patient clinics. Previous in vivo studies had shown that an Aqueous M. citrifolia Fruit Extract
(AMFE) possessed anti-inflammatory and ulcer healing activities. Therefore, a standardized topical
bioadhesive gel containing AMFE-phytosome was developed and determined for its oral ulcer
healing efficacy in a rabbit model.

Methods:

The AMFE phytosome (AMFE-P) was prepared by a complexation method with the required
amount of AMFE: Phosphatidylcholine: Tween 80 to weigh ratio of 2:1:0.2. Poloxamer 407
was used as a gelling agent. The oral ulcer was induced in male New Zealand white rabbits by topical
application of acetic acid. Each test compound was applied to the ulcer for 10 days beginning on the
second day after the ulcer induction. Complete ulcer healing on the specimen obtained on day 12 was
observed histologically using the histological scoring protocol.

Results:

The optimized gel containing AMFE-P equivalent to AMFE 10%w/w (10%AMFE-P gel)
showed the best bioadhesive gel quality, a smooth and homogeneous texture with an optimum viscosity
and pH range used in human oral cavity, a good physical and chemical stability and the highest percentage
cumulative release of total phenolic and scopoletin content. It was found that a daily application of
10% AMFE-P gel exerted a superior ulcer healing efficacy and a significantly rapid ulcer healing process
than a twice daily application of topical gel containing AMFE 10%w/w or chlorhexidine 0.2%.

Conclusion:

These findings demonstrated that 10% AMFE-P gel has potential as a safe and effective
alternative therapeutic agent for oral ulcers.
Dietary Quercetin Alleviated DSS-induced Colitis in Mice Through Several Possible Pathways by Transcriptome Analysis
Authors: Dong Yuanyang , Lei Jiaqi , Zhang Bingkun
Published: July 2020

Background:

The prevalence of inflammatory bowel disease is rapidly increasing around
the world. Quercetin is a flavonoid commonly found in vegetables and fruits and has been reported to
exert numerous pharmacological activities such as enhancing antioxidant capacity or suppressing inflammation.

Objective:

We aimed to explore whether quercetin was effective for IBD and the underlying mechanism
of quercetin for the ameliorative effects on the DSS-induced colitis in mice.

Methods:

Thirty-six mice were randomly assigned to three treatments, including the control group
(Ctr), DSS-induced colitis group (DSS) and DSS-induced colitis supplemented with 500 ppm quercetin
(DQ500). Colitis was induced by DSS intake, and body weight was recorded every day. After six days
administration of DSS, intestinal permeability was measured, and the liver was taken for antioxidant enzyme
tests. Colonic tissue was taken for the histopathlogical score and RNA-sequencing analysis.

Results:

In this experiment, dietary quercetin for 500ppm alleviated the DSS-induced colitis, possibly
by strengthening intestinal integrity, liver antioxidant capacity. Based on the results of the transcriptome
of colon tissue, several key genes were modulated by quercetin. ERK1/2-FKBP pathway and
RXR-STAT3 pathway were involved in the development of IBD, furthermore, in the down-regulation
of S100a8/9, FBN2 contributed to lowering the risk of colongenesis.

Conclusion:

We demonstrated that dietary quercetin alleviated the DSS-induced colitis in mice. This is
most likely due to its beneficial effects on intestinal integrity and modulation of several key pathways.
Based on our research, quercetin was a promising candidate for IBD and its pharmaceutical effects on
both IBD and colongenesis need further research.
Chitosan Nanoparticles as a Novel Drug Delivery System: A Review Article
Authors: Matalqah Sina M. , Aiedeh Khalid , Mhaidat Nizar M. , Alzoubi Karem H. , Bustanji Yasser , Hamad Islam
Published: July 2020

Natural polymers, particularly polysaccharide, have been used as drug delivery systems for a variety of therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and non-parenteral administration. Chitosan, the second most abundant naturally occurring polysaccharide after cellulose, is a biocompatible and biodegradable mucoadhesive polymer that is extensively used in the preparation of nanoparticles (NPs). Chitosan NPs loaded with drugs were found to be stable, permeable and bioactive. In this review, the importance of chitosan and its derivatives in drug delivery is illustrated, different methods of preparation of chitosan and chitosan derivatives NPs and their physio- chemical properties are addressed. Moreover, the desirable characteristics of successful NPs based drug delivery systems, as well as the pharmaceutical applications of these NPs are also clearly explored.
Piperonal: The Journey so Far
Authors: Akash Jain , Dushyant Chaudhary , Jasmine Chaudhary
Published: July 2020

Piperonal, an important aromatic aldehyde containing the benzene ring fused to 1, 3-
dioxolane moiety, widely occurred in nature and known for its fragrance similar to vanillin and cherry.
Alterations in its structural features led to the access of a wide range of piperonal derivatives viz. pyrazolines,
chalcones, benzothiazepines, benzoxazoles, triazoles etc. having remarkable pharmacological
properties like antimicrobial, anticancer, antidiabetic, antitubercular activities, etc. Therefore, the present
study has been designed to highlight the progress made in the area of piperonal and its derivatives
till date with respect to their synthesis and pharmacological activities. This may facilitate the synthesis
of more novel derivatives with improved biological activities. Various search engines like google,
Pubmed, Scopus etc. were used to gather the related information using different keywords.
Future and Perspectives of the Zika Virus: Drug Repurposing as a Powerful Tool for Treatment Insights
Authors: Rampini Denise , Prieto Diego Campos , Colzi Ana Luisa , de Araújo Renan Vinícius , Giarolla Jeanine
Published: July 2020

The Zika virus (ZIKV) infection is a major public health concern in Brazil and worldwide,
being a rapidly spreading disease with possible severe complications for pregnant women and neonates.
There is currently no preventative therapy or specific treatment available. Within this context,
drug repositioning is a very promising approach for the discovery of new treatment compounds, since
old drugs may become new ones. Therefore, this paper aims to perform a literature mini-review to
identify promising compounds to combat this virus. The mechanism of action at the molecular level
and the structure-activity relationship of prototypes are discussed. Among the candidates identified, we
highlight sofosbuvir, chloroquine and suramin, which present a greater quantity of experimental data to
draw on for our discussion. The current treatment is palliative; therefore, this study is of paramount
importance in identifying drug candidates useful for combating ZIKV.
Withdrawal Notice: A Panoramic View on the Phytochemical, Nutritional and Therapeutic value of Ziziphus mauritiana Lam.: A Comprehensive Review
Authors: Prakash Om , Usmani Shazia , Singh Ruchi , Singh Namrata , Gupta Amresh
Published: July 2020

The article has been withdrawn at the request of the authors of the journal Mini-Reviews in Medicinal
Chemistry:;

Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused.

The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php

Bentham Science Disclaimer:

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A Facile, Efficient Step-Wise and Alternative Synthesis of Indolyl Triazoles via “Click” Chemistry
Authors: Reddy G. Ganga , Reddy B. Srinivasa , Reddy Ch. Venkata Ramana
Published: July 2020

series of new 1,2,3 triazoles hybrids were synthesized using a Cu-catalysed azide-alkyne
cycloaddition reaction. Thus, a remarkable rapid click reaction of aryl azides with terminal alkynes at
room temperature in DMF afforded new 4-((1-((1-(4-methoxy-3-nitrophenyl)-1H-1,2,3-triazol-4-
yl)methyl)-1H-indol-3-yl)methylene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-ones in good to excellent
yields. The reaction provides a safe, efficient and economic approach for the synthesis of various 1,2,3
triazoles. The reaction has many advantages like shorter reaction times, good yields of products and
isolation of the products without the need for column chromatography. By using knoevenagel reaction
under physical grinding with alkylating agents prepared various 1,2,3 triazoles.
Vilsmeier-Haack Cyclisation as A Facile Synthetic Route to Thieno [2,3- b] quinolines (Part I)
Authors: Abu-Hashem Ameen A. , Abdelgawad Ahmed A. M. , Gouda Moustafa A.
Published: July 2020

:

This review describes the utilizing of Vilsmeier-Haack reagent as a key intermediate for the synthesis of
thieno[2,3-b]quinolines.
Photocatalytic Bacteria Inactivation by TiO2-Ag based Photocatalysts and the Effect on Antibiotic Resistance Profile
Authors: Ozkal Can B. , Meric Süreyya
Published: July 2020

Background:

In the last decade, research in the field of contaminants of emerging concern
proliferated while special interest was focused on antibiotic-resistant bacteria, antibiotic resistance
genes as widespread pollutants. Advanced oxidation processes have gained an essential attraction in
the field of antibiotics degradation and bacteria inactivation

Methods:

Photocatalysts in the form of sol-gel based TiO2-Ag-xerogel and green synthesized
nanocomposites TiO2-Ag compared with regard to their bacteria inactivation performances and effect
on antibiotic resistance behaviour of target strain. Experiments were carried out at parallel plate
reactor configuration under UV-A irradiation with an energy equivalent of solar conditions. PEG 600
and Cydonia oblanga seed extract were used as chemical and bio-chemical reducing-stabilizing
agents respectively for the synthesis of TiO2-Ag nano-composite.

Results:

Photocatalyst type/size based alterations in antibiotic resistance profile of intact and post
treatment bacteria cells were examined. Besides the improvement in bacteria inactivation kinetics,
photocatalytic disinfection with Ag doped xerogels and TiO2-Ag nanocomposites have triggered
alterations on E.coli DSM-498 resistance to tetracycline and aminoglycoside antibiotics.

Conclusıon:

Cydonia oblanga seed extract is proved to be a promising green substitute for the TiO2-
Ag chemical synthesis procedure. Considering the aspects of the economic and environmental impact
of nano-composite photocatalyst synthesis, cost reduction is achievable both in the sense of
production and disposal. The complexity of water matrix must be considered in a way to determine
the wide range applicability of the green synthesis of a nano-composite at the pilot scale.
Metallic Impurities in Pharmaceuticals: An Overview
Authors: Kushwaha Poonam
Published: July 2020

Backgroun:

Metallic impurities are the traces of metals that can be found in finished drug products.

Description:

These metallic impurities in pharmaceutical preparations can enter from formulation ingredients,
catalysts, and process equipment, containers and closures. They are not completely removed
from the product by practical manufacturing techniques and should be evaluated relative to safetybased
limits. They can affect drug efficacy or produce direct toxic effect on the patient.

Methods:

In this paper, an attempt has been made to review these metallic impurities including potential
sources and analytical procedures to quantify these impurities. ICH guideline on these impurities
and measures to control impurities has also been discussed in the paper.

Results:

The implementation of ICH Q3D guideline with the quality risk assessment approach is an
important milestone to harmonize control of elements worldwide.

Conclusion:

This approach allows manufacturers to provide vital information about the contribution of
impurities in the drug product.
Review of the Applications of Deep Learning in Bioinformatics
Authors: Zhang Yongqing , Yan Jianrong , Chen Siyu , Gong Meiqin , Gao Dongrui , Zhu Min , Gan Wei
Published: July 2020

Rapid advances in biological research over recent years have significantly enriched
biological and medical data resources. Deep learning-based techniques have been successfully
utilized to process data in this field, and they have exhibited state-of-the-art performances even on
high-dimensional, nonstructural, and black-box biological data. The aim of the current study is to
provide an overview of the deep learning-based techniques used in biology and medicine and their
state-of-the-art applications. In particular, we introduce the fundamentals of deep learning and then
review the success of applying such methods to bioinformatics, biomedical imaging, biomedicine,
and drug discovery. We also discuss the challenges and limitations of this field, and outline possible
directions for further research.
Extracting Gradual Rules to Reveal Regulation Between Genes
Authors: Gouider Manel , Hamdi Ines , Ghezala Henda Ben
Published: July 2020

Background:

Gene regulation represents a very complex mechanism in the cell initiated
to increase or decrease gene expression. This regulation of genes forms a Gene regulatory Network
GRN composed of a collection of genes and products of genes in interaction. The high throughput
technologies that generate a huge volume of gene expression data are useful for analyzing the
GRN. The biologists are interested in the relevant genetic knowledge hidden in these data sources.
Although, the knowledge extracted by the different data mining approaches of the literature is
insufficient for inferring the GRN topology or does not give a good representation of the real
genetic regulation in the cell.

Objective:

In this work, we are interested in the extraction of genetic interactions from the high throughput
technologies, such as the microarrays or DNA chips.

Methods:

In this paper, in order to extract expressive and explicit knowledge about the interactions
between genes, we used the method of gradual patterns and rules extraction applied on numerical
data that extracts the frequent co-variations between gene expression values. Furthermore, we
choose to integrate experimental biological data and biological knowledge in the process of
knowledge extraction of genetic interactions.

Results:

The validation results on real gene expression data of the model plant Arabidopsis and human lung
cancer shows the performance of this approach.

Conclusion:

The extracted gradual rules express the genetic interactions composed of a GRN.
These rules help to understand complex systems and cellular functions.
Exploring miRNA Sponge Networks of Breast Cancer by Combining miRNA-disease-lncRNA and miRNA-target Networks
Authors: Tian Lei , Wang Shu-Lin
Published: July 2020

Background:

Recently, ample researches show that microRNAs (miRNAs) not only
interact with coding genes but interact with a pool of different RNAs. Those RNAs are called
miRNA sponges, including long non-coding RNAs (lncRNAs), circular RNA, pseudogenes and
various messenger RNAs. Understanding regulatory networks of miRNA sponges can better help
researchers to study the mechanisms of breast cancers.

Objective:

We develop a new method to explore miRNA sponge networks of breast cancer by combining miRNAdisease-lncRNA and miRNA-target networks (MSNMDL).

Method:

Firstly, MSNMDL infers miRNA-lncRNA functional similarity networks from miRNAdisease-
lncRNA networks. Secondly, MSNMDL forms lncRNA-target networks by using lncRNA
to replace the role of matched miRNA in miRNA-target networks according to the lncRNA-miRNA
pair of miRNA-lncRNA functional similarity networks. And MSNMDL only retains the genes of
breast cancer in lncRNA-target networks to construct candidate miRNA sponge networks. Thirdly,
MSNMDL merges these candidate miRNA sponge networks with other miRNA sponge interactions
and then selects top-hub lncRNA and its interactions to construct miRNA sponge networks.

Results:

MSNMDL is superior to other methods in terms of biological significance and its identified modules might
act as module signatures for prognostication of breast cancer.

Conclusion:

MiRNA sponge networks identified by MSNMDL are biologically significant and are
closely associated with breast cancer, which makes MSNMDL a promising way for researchers to
study the pathogenesis of breast cancer.
Antitubercular Potential of Novel Isoxazole Encompassed 1, 2, 4- Triazoles: Design, Synthesis, Molecular Docking Study and Evaluation of Antitubercular Activity
Authors: Ganesh Neenu , S Arun Kumar , Singh Manisha , Chandrashekar Venkaraddi Mangannavar , Pujar Gurubasavaraj Veeranna
Published: July 2020

Background:

Decaprenylphosphoryl-β-D-ribose epimerase (DprE1), a flavoprotein enzyme
engaged in the biosynthesis of decaprenylphosphoryl-β-D-arabinofuranose (DPA), is the only
contributor of arabinose residues which is fundamental for the mycobacterium cell wall constituents.
DprE1 is an interesting target for antitubercular agent and has been exploring to develop potential
chemical entities as antitubercular agents.

Objective:

The objective of the study is the development of novel antitubercular agents targeting
Mtb Decaprenylphosphoryl-β-D-ribose epimerase (DprE1).

Methods:

A series of isoxazole encompassed 1, 2, 4-triazoles were designed based on the antitubercular
potential of triazoles and structural features of DprE1 inhibitors. Designed 1, 2, 4-
triazoles were synthesized and characterized by spectral studies. The in vitro anti-TB activity of the
compounds was screened against Mycobacterium tuberculosis H37Rv strain by Microplate Almar
Blue Assay and in vitro cytotoxicity against normal cell lines by MTT assay. Molecular docking
study was carried out on DprE1 enzyme to understand designed compounds interactions with amino
acid residues at the active site.

Results:

Antitubercular activity data revealed that eight compounds (6d, 6e,7d, 7e, 10d, 10e, 11d
and 11e) have shown promising antitubercular activity with minimum inhibitory concentration at
1.6μg/mL. Cytotoxicity data of anti-TB active compounds demonstrate good safety profile on
normal cell lines.

Conclusion:

Eight compounds have shown promising antitubercular activity with good safety profile
on normal cell lines. Molecular docking study revealed that the synthesized compounds have
shown non-covalent interactions with amino acid residues of DprE1 enzyme.
Formulation and Evaluation of Nanosponges Loaded Bifonazole for Fungal Infection
Authors: Krishna Amaravathi V.M. , Gowda Venkatesh D.P. , Karki Roopa
Published: July 2020

Background:

Nanosponge is a novel approach to topical drug delivery, especially for
fungal infections. Nanosponges are a unique class of nanoparticles with three-dimensional
nanostructure and nanometers wide cavities, which can encapsulate both hydrophilic and lipophilic
substances providing increased efficacy and safety.

Objective:

To formulate and evaluate Bifonazole loaded nanosponges in hydrogels for the treatment
of fungal diseases.

Methods:

Bifonazole-loaded nanosponges were formulated using the emulsion solvent diffusion
technique. Interaction of drug-ethyl cellulose polymer along with other excipients’ was done by using
FTIR as well as DSC. The nanosponges formulations were evaluated with different parameters.

Results:

Particle size and Zeta potential of Bifonazole loaded nanosponges for formulations were
between the range of 183.7 to 560.2 nm and –17.77 to –21.9 mV, respectively. The surface morphology
of nanosponges by SEM disclosed that it was spherical and porous in nature. Drug entrapment
efficiency was found to be 45.44 to 79.71%. The drug release study was done by using a
phosphate buffer with a pH of 6.8. Further in vitro release data was fitted into kinetic models. The
optimized formulation M6 was incorporated with hydrogels; to further evaluated using parameters
such as in vitro drug release studies, viscosity, pH and skin irritation studies using rat model. Stability
studies of hydrogel formulation MH2 revealed no changes in in-vitro drug release, pH and drug
content study at the completion of 6 months.

Conclusion:

Thus, the findings indicated that the prepared Bifonazole loaded nanosponges into hydrogel
were stable. Hence, it could be a suitable dosage form for the cure of fungal infections in the skin.
The in Vivo Effects of Cassia Abbreviata Oliv., on Sperm Parameters And Testicular Histology of The Male Wistar Rat
Authors: Msiska Thomson , Mwakikunga Anthony , Tembo David , Musopole Alinune , Lampiao Fanuel
Published: July 2020

Introduction:

A lot of unsubstantiated claims have been made regarding the ability of
Cassia abbreviata Oliv. to promote male reproductive function. The study was aimed at evaluating
the effects of aqueous and 50% (v/v) methanol stem bark extracts of Cassia abbreviata Oliv. on
hormonal levels, sperm parameters, testicular histo-architecture, mean body and right testis weights
of the male Wistar rat.

Methodology:

Thirty healthy adult male Wistar rats were divided into five groups. Group A, control rats received pure tap
water; group B received aqueous extracts at 200 mg/kg body weight; group C received aqueous extracts at 400 mg/kg
body weight; group D received 50% (v/v) methanol extracts at 200 mg/kg body weight and group E received 50% (v/v)
methanol extract at 400 mg/kg body weight. After 8 weeks, reproductive organ weights, sperm parameters, hormonal levels and histological structure of the right testis were evaluated.

Results:

Testosterone, luteinizing hormone, estradiol, follicle-stimulating hormone levels were significantly increased
(p<0.05) whereas prolactin levels were significantly decreased (p<0.05) in the treated groups compared to the control. Total sperm motility, sperm concentration and the percentage of progressively motile cells increased significantly (p<0.05)
compared to the control. All the treated animals showed an increase in seminiferous tubule diameter and germinal epithelial height with the testes showing all the stages of spermatogenesis. Phytochemical screening of both extracts showed the
presence of of flavonoids, phenols, tannins, saponins and alkaloids.

Conclusion:

Cassia abbreviata Oliv. increased sperm parameters, reproductive hormones and mean body weight of the
male Wistar rat. This study supports the folklore claims that Cassia. abbreviata Oliv.modulates male reproductive function.
Структура и фотоэлектрические свойства пленок PbSe, осажденных в присутствии аскорбиновой кислоты
Authors: Маскаева Л.Н. , Юрк В.М. , Марков В.Ф. , Кузнецов М.В. , Bоронин В.И. , Липина О.А.
Published: July 2020

PbSe thin films chemically deposited using ascorbic acid as an antioxidant for selenourea were examined by X -ray diffraction (XRD), scanning electron microscopy (SEM) with X -ray microanalysis (EDX) and X -ray photoelectron spectroscopy (XPS). Influence of annealing temperature on chemical and phase composition, lattice parameters, surface morphology and photoelectric properties were studied. Determined that PbSe thin films contain dopant phase PbSeO3, PbSeO4, PbI2 after annealing at 633−683K. The direct and indirect optical band gaps Eg layers were observed. It has been shown that the deposited films are comparable with known commercial samples by their threshold photoelectric characteristics and can be used to create highly sensitive IR detectors.
Исследование встроенных электрических полей на интерфейсе GaSe/GaAs методом спектроскопии фотоотражения
Authors: Комков О.С. , Хахулин С.А. , Фирсов Д.Д. , Авдиенко П.С. , Седова И.В. , Сорокин С.В.
Published: July 2020

The built-in electric fields are generated at the GaSe/GaAs heterointerface when GaSe layers are grown by molecular beam epitaxy on GaAs(001) substrates. The existence of these fields is indicated by the clearly observed Franz–Keldysh oscillations in the photoreflectance spectra. The different values of the intensities of these fields (within the 9.8−17.6 kV/cm range) can be associated both with the diffusion of Se atoms into the GaAs substrate (or into the GaAs buffer layer) and the formation of transition sub-monolayers at initial growth stages. No built-in fields were observed at the GaSe/GaAs heterointerface in case of GaSe layers grown on GaAs(111)B and GaAs(112) substrates, which can be explained by the lower efficiency of Se penetration into these substrates in contrast to GaAs(001).
Спонтанное и стимулированное излучение в тонких пленках твердых растворов Cu(In-=SUB=-1-x-=/SUB=-Ga-=SUB=-x-=/SUB=-)(S-=SUB=-y-=/SUB=-Se-=SUB=-1-y-=/SUB=-)-=SUB=-2-=/SUB=- в составе солнечных элементов
Authors: Свитенков И.Е. , Павловский В.Н , Муравицкая Е.В. , Луценко Е.В. , Яблонский Г.П. , Бородавченко О.М. , Живулько В.Д. , Мудрый А.В. , Якушев М.В. , Когновицкий С.О.
Published: July 2020

The results of a study of the emission spectra of thin nanocrystalline films of Cu(In1-xGax)(SySe1-y)2 (CIGSSe) direct-band-gap solid solutions in the structure of solar cells at ~ 0.5 W/cm2 continuous wave and nanosecond pulsed laser excitation in the range of excitation power density 0.1 - 53 kW/cm2 and temperatures of 10-300 K are presented. It was found that stimulated emission (SE) occurs in thin CIGSSe films in the temperature range from 10 K to 90 K in the spectral region h = 1.062 - 1.081 eV with a minimum threshold pump level of about 1 kW/cm2. It was shown, that, with increasing intensity of the exciting emission, the spontaneous emission bands shift toward higher energies. It was found that the photoluminescence bands at low excitation levels and the SE bands shift with increasing temperature toward higher energies, and the PL bands at high excitation levels shift toward low energies. Possible causes and mechanisms of the influence of temperature and excitation intensity on the spectral positions of spontaneous and SE of the films of solid solutions are discussed.
Сравнительный анализ оптических и физических свойств квантовых точек InAs, In-=SUB=-0.8-=/SUB=-Ga-=SUB=-0.2-=/SUB=-As и фотоэлектрических преобразователей на их основе
Authors: Салий Р.А. , Минтаиров С.А. , Надточий А.М. , Неведомский В.Н. , Шварц М.З. , Калюжный Н.А.
Published: July 2020

Методом металлоорганической газофазной эпитаксии получены квантовые точки InAs и In0.8Ga0.2As в матрице GaAs, а также GaAs-фотопреобразователи с квантовыми точками обоих типов в i-области. В результате исследования методами фотолюминесценции и просвечивающей электронной микроскопии установлено, что ансамбль квантовых точек In0.8Ga0.2As имеет высокую однородность, содержит меньшее число дефектных квантовых точек большого размера, а также обеспечивает снижение механических напряжений в структуре. Анализ спектральных зависимостей внутреннего квантового выхода показал сохранение качества матрицы фотоэлектрического преобразователя с квантовыми точками In0.8Ga0.2As на уровне, близком к качеству реперного GaAs-фотопреобразователя при встраивании до 20 рядов квантовых точек. При этом обеспечивается линейный прирост добавочного фототока, генерированного за счет поглощения подзонных фотонов в квантовых точках In0.8Ga0.2As, с увеличением количества рядов квантовых точек, так как сохраняется величина прироста фототока в пересчете на один ряд. Ключевые слова: фототок, квантовые точки, фотоэлектрические преобразователи.
Физико-химические взаимодействия в системе GeSb-=SUB=-2-=/SUB=-Te-=SUB=-4-=/SUB=--PbSb-=SUB=-2-=/SUB=-Te-=SUB=-4-=/SUB=-
Authors: Гурбанов Г.Р. , Адыгезалова М.Б.
Published: July 2020

Впервые комплексными методами (дифференциально-термический, микроструктурный, рентгенофазовый анализы измерением микротвердости и определением плотности) физико-химического анализа исследован разрез GeSb2Te4-PbSb2Te4 квазитройной системы GeTe-Sb2Te3-PbTe и построена диаграмма состояния. Установлено, что разрез является частично квазибинарным сечением квазитройной системы GeTe-Sb2Te3-PbTe. Выявлена область твердых растворов на основе GeSb2Te4 (15 мол%, PbSb2Te4). При соотношении исходных компонентов 1:1 образуется конгруэнтно-плавящееся соединение GePbSb4Te8. Методом химических транспортных реакций получены монокристаллы четверного соединения GePbSb4Te8. Определены параметры элементарной ячейки GePbSb4Te8, кристаллизующейся в ромбической сингонии: a=5.06 Angstrem, b=9.94 Angstrem, c=11.62 Angstrem. Исследованием температурных зависимостей некоторых электрофизических параметров соединения GePbSb4Te8 и твердого раствора (GeSb2Te4)x (PbSb2Te4)1-x установлено, что сплавы имеют p-тип проводимости. Ключевые слова: квазитройные системы, монокристаллы, физико-химический анализ, твердые растворы, химические транспортные реакции.
Особенности МДП-структур на основе изолирующих пленок PbSnTe : In с составом вблизи инверсии зон, обусловленные их сегнетоэлектрическими свойствами
Authors: Климов А.Э. , Акимов А.Н. , Ахундов И.О. , Голяшов В.А. , Горшков Д.В. , Ищенко Д.В. , Матюшенко Е.В. , Неизвестный И.Г. , Сидоров Г.Ю. , Супрун С.П. , Тарасов А.С. , Терещенко О.Е. , Эпов В.С.
Published: July 2020

The characteristics of MIS structures based on insulating PbSnTe:In films with compositions in the vicinity of a band inversion grown by molecular beam epitaxy (MBE) were studied. It has been shown that a number of their features can be caused by a ferroelectric phase transition with a Curie temperature in the range T ≈ 15–20 K.
Наращивание слоя Ge на структуру Si/SiO-=SUB=-2-=/SUB=-/Si (100) методом "горячей проволоки"
Authors: Сушков А.А. , Павлов Д.А. , Денисов С.А. , Чалков В.Ю. , Крюков Р.Н. , Питиримова Е.А.
Published: July 2020

Ge/Si buffer layers grown at different temperatures on Si/SiO2/Si (100) substrates have been fabricated and studied. The Si buffer was grown via molecular beam epitaxy. The Ge layer was produced in a single stage via hot wire chemical vapor deposition process. Structural properties were investigated by high-resolution transmission electron microscopy and reflected high-energy electron diffraction. Such structures can be used in the future as a substrate for growth of high quality light-emitting structures compatible with silicon radiation-resistant integrated circuits. The paper shows the possibility of growth of a single crystal layer of Ge on Si/SiO2/Si (100) through a buffer layer of Si by the hot wire chemical vapor deposition process, and also demonstrates the difficulties that arise in the process of growth of Ge/Si layers on Si/SiO2/Si (100).
Поведение доноров лития в объемных монокристаллических моноизотопных сплавах -=SUP=-28-=/SUP=-Si-=SUB=-1-x-=/SUB=--=SUP=-72-=/SUP=-Ge-=SUB=-x-=/SUB=-
Authors: Ежевский А.А. , Сенников П.Г. , Гусейнов Д.В. , Сухоруков А.В. , Калинина Е.А. , Абросимов Н.В.
Published: July 2020

We studied the behavior of lithium donors in bulk single-crystal single-crystal alloys Si1-xGex, (x=0.0039-0.05), enriched in spinless isotopes 28Si (99.998%) and 72Ge (99.984%) by electron paramagnetic resonance (EPR). The fine structure of the spectrum of a donor electron localized on lithium (T=3.5–30 K) was studied under the assumption that, when spinless isotopes (28Si isoGe, iso = 70, 72, 74, 76) are enriched in Si1-xGex alloys, it is possible to achieve in higher resolution in the EPR spectra as was observed in silicon. Studies have shown that despite the irregular arrangement of germanium atoms in the lattice of a SiGe, the local distortions they create and the broadening of the EPR lines of donor electrons due to random deformations in isotopically pure 28Si1-х72Geх single crystals at x=0.39; 1.2; 2.9 %, narrower lines of the ESR spectra of lithium were observed in comparison with similar crystals with a natural composition of silicon and germanium isotopes, which made it possible, as in silicon, to study for the first time the angular dependences of the line positions in the ESR spectra of lithium in Si1-xGex for various x.
Кинетика люминесцентного отклика самоформирующихся наноостровков Ge(Si), встроенных в двумерные фотонные кристаллы
Authors: Яблонский А.Н. , Новиков А.В. , Степихова М.В. , Сергеев С.М. , Байдакова Н.А. , Шалеев М.В. , Красильник З.Ф.
Published: July 2020

Представлены результаты исследования спектрально-кинетических характеристик фотолюминесценции двумерных фотонных кристаллов, полученных на основе структур c самоформирующимися наноостровками Ge(Si). Рассматривается наблюдаемое в таких структурах увеличение интенсивности сигнала фотолюминесценции наноостровков в спектральном диапазоне 1.1-1.6 мкм в результате взаимодействия с излучательными модами фотонных кристаллов вблизи точки зоны Бриллюэна и влияние такого взаимодействия на вероятность излучательной рекомбинации в наноостровках Ge(Si). Ключевые слова: наноостровки Ge(Si), фотонные кристаллы, фотолюминесценция, кинетика фотолюминесценции, эффект Парселла.
Сравнение эффективности перспективных гетероструктурных умножительных диодов терагерцового диапазона частот
Authors: Дюков Д.И. , Фефелов А.Г. , Коротков А.В. , Павельев Д.Г. , Козлов В.А. , Оболенская Е.С. , Иванов А.С. , Оболенский С.В.
Published: July 2020

Приводятся результаты теоретического и экспериментального сравнения эффективности преобразования сигналов диодами на основе сверхрешеток с малым числом периодов (N-образная вольт-амперная характеристика) и перспективными умножительными гетеробарьерными диодами (варакторами) (вольт-фарадная характеристика параболического вида). Ключевые слова: диоды на основе сверхрешеток, нелинейная вольт-амперная характеристика, варактор, вольт-фарадная характеристика параболического вида, умножители частоты сигналов.
Непрерывное стимулированное излучение в области 10-14 мкм при оптической накачке в структурах с квантовыми ямами HgCdTe/CdHgTe с квазирелятивистским законом дисперсии
Authors: Уточкин В.В. , Алёшкин В.Я. , Дубинов А.А. , Гавриленко В.И. , Куликов Н.С. , Фадеев М.А. , Румянцев В.В. , Михайлов Н.Н. , Дворецкий С.А. , Разова А.А. , Морозов С.В.
Published: July 2020

В двух волноводных гетероструктурах с массивами квантовых ям Hg0.892Cd0.108Te/Cd0.63Hg0.37Te толщиной 6.1 нм и Hg0.895Cd0.105Te/Cd0.66Hg0.34Te толщиной 7.4 нм при 8 K впервые получено стимулированное излучение на длинах волн 10.3 и 14 мкм при непрерывном оптическом возбуждении. Показано, что благодаря наличию Cd в квантовых ямах уменьшается влияние флуктуаций толщины квантовых ям на энергию межзонных переходов в ней, что в итоге может являться причиной существенного уменьшения пороговой интенсивности для генерации стимулированного излучения. Ключевые слова: HgCdTe, квантовые ямы, стимулированное излучение, непрерывная генерация.
The Spiral of Recovery: Mental Health and Psychosocial Support during a COVID-19 Environment in the Americas
Authors: Diaz Joseph O. Prewitt
Published: July 2020

This article introduces a path through feelings and emotions, as well as the tasks that should be completed as part of a social evolution of behavior. A Spiral of Recovery model is presented. This article explains the model, and includes the current tasks that have been taking place, to move from immediate response to early- and mid-recovery.
Development of improved models for pile load bearing capacity, settlement and reliability analysis
Authors: Utkin Vladimir S. , Solovyev Sergey A.
Published: July 2020

Introduction. Safety of operation and durability of pile foundations and structures as a whole depend on the values of load bearing capacity of piles and reliability in the foundation soils. The key problem of pile analysis consists in reliable determination of its load bearing capacity values according to all performance criteria of the first and second groups of limit states, in revealing of reliable values of reliability (operation safety), economic efficiency and profitability.

Materials and methods. One of the difficulties in detecting the value of the load bearing capacity of friction piles is to determine the values of friction and cohesive forces and their distribution over the side surface of the pile in the foundation soil when the loaded pile is immobilized (at rest).

Results. Absence of reliable information on actual friction and cohesive force and, consequently, on actual load bearing capacity of a pile in the conditions of immobility does not allow to estimate its quality taking into account assurance of trouble-free operation (reliability) in real operating conditions at the pre-set operating load, it is impossible to predict the durability of a pile, to make a reasonable choice of pile shape and dimensions, etc. Another pile analysis problem is determining the value of pile settlement. The value of pile settlement is in some cases the most important indicator of the facility performance.

Conclusions. New approaches to the operation of piles in the foundation soil on the basis of modern methods of reliability calculations with limited statistical information about controlled parameters are proposed. Improvement and development of pile calculation methods can be found in the calculation of deep trencher foundations, in the calculation of open caissons and caissons, the development of new statutory documents on pile foundations; as well as during training process of various universities and as a source for advanced training of specialists.
Study of synergetic effect of the complex polycarboxylate anti-corrosion additive in the model of pore concrete fluid
Authors: Talipov Linar N. , Velichko Evgeny G. , Semenov Vyacheslav S.
Published: July 2020

Introduction. Corrosion of reinforcement in concrete structures is rather expensive for the economy of any country. Current statutory documents offer two main directions — primary and secondary protection. One of the promising areas of primary protection methods is the use of complex anti-corrosion additives in concrete due to its technological simplicity and economic efficiency. Passivators and surfactants (SAS), as components of such additives, are of particular interest. Sodium nitrite is offered as a passivator, and polycarboxylate molecules (PCE) — as a SAS. The additive of sodium nitrite together with PCE has a visual synergistic effect. Materials and methods. Identification of structural characteristics of the molecules of the obtained PCE polymers was determined by methods of exclusion gel-permeation chromatography and 13C NMR spectroscopy. To study the synergetic effect of NaNO2 + PCE additive, the samples were kept in the models of pore liquid, after which the morphology of their surface was studied by methods of scanning electron microscopy and electron probe microanalysis. Results. The texture and surface color of the presented micrographs indicate surface formations on the samples stored in the models of pore liquid with different anti-corrosion additives. Electron probe microanalysis showed increased concentrations of carbon, oxygen and sodium on the surface of samples stored in pore concrete liquid models with the addition of a complex anti-corrosion additive of sodium nitrite and PCE, which indicates increased concentrations of PCE and possible increased pH on the steel surface. Based on the data acquired, the mechanism of formation of a protective film layer using complex anti-corrosion additive NaNO2 + PCE is offered. Conclusions. Justification of synergetic effect of complex polycarboxylate anti-corrosion additive in the model of concrete pore liquid opens up prospects for research of such additives to the concrete model.
Velocity rate of screw streams in the site of submerged vanes
Authors: Klovsky Alexey V. , Kozlov Dmitry V.
Published: July 2020

Introduction. The formation mechanism of longitudinal screw streams (LSS) along the upstream and downstream face of submerged vanes (SV) is considered. Acting along with the artificial transversal circulation (ATC), these streams protect the water intake from the channel sediments. The intensities and directions of LSS and ATC depend on the regime of flow, the planned-geometric characteristics of the vanes. Recommendations concerning the purpose of SV’s rational characteristics in the aspect of steady formation of all three protective streams in the flow for river damless intakes are contradictory and require clarification. The purpose of the study is to analyze the velocity rate of the LSS in SV site at various planned-geometric characteristics of the vane and hydraulic modes of its operation based on a physical model with an erosion-resistant channel (without water separation), as well as to determine an efficient range of setting angles of the SV’s to the tray board in terms of formation of steady and intensive LSS along the upstream and downstream face of the vane.

Materials and methods. Model physical hydraulic studies and theoretical calculations were used. Five hydraulic modes of SV’s operation were studied, with various planned-geometric characteristics, using the physical model with an erosion-resistant channel (without water separation). The obtained experimental data were summarized and analyzed.

Results. Results of laboratory hydraulic studies of LSS velocity rate in LSS site were presented. Experimental graphic dependence diagrams were plotted characterizing the intensity and direction of the LSS along upstream and downstream faces of the vane.

Conclusions. A determining influence of the setting angle of the vane to the tray board (bank line) on the intensity and direction of the LSS in SV’s site was found out. Experimentally, an efficient SV setting angle was determined in terms of the formation of steady and intensive LSS along the upstream and the downstream vane face with practically usable direction.
Method of substantiation of organizational and processing characteristics of the complex of construction sites based on linear fractional programing
Authors: Popova Ekaterina M. , Ptukhina Irina S. , Radaev Anton E.
Published: July 2020

Introduction. In the field of implementation of integrated programs of housing construction as a promising direction from the point of view of solution of the most important problems of modern development of the construction industry (intensive growth of urban areas, low quality and high cost of new housing, poor infrastructure), the key task has been set: rationale of the characteristics of the complex of construction sites taking into account interrelations between the number and characteristics of residential buildings and infrastructure facilities. Based on the results of the analysis of the relevant scientific literature, the conclusion was made that the existing tools are limited and fully take into account the key features of the implementation of integrated programs of housing construction. Relevance of research which objective is development of a method of substantiation of characteristics of a complex of construction sites is substantiated.

Materials and methods. The organizational and process characteristics method of the complex of construction sites on the basis of linear fractional programming, which implies the determination of the optimal number of housing construction sites and infrastructure facilities in the context of different instances and categories by the criterion of maximizing the profitability index of the corresponding construction project was developed. The key elements of the developed method are optimization models, which are linear relatively unknown variables and therefore implemented using simplex method in modern software environments of optimization modeling.

Results. The developed method is implemented on a practical example using Microsoft Excel software environment and the “Solution Finder” add-in. As a result of performance of corresponding calculation procedures, concrete values of quantity of sites and infrastructure facilities within the limits of the building project have been received.

Conclusions. On the basis of adequate results obtained from the implementation of the proposed methodology on practical example, the conclusion was made about the high practical significance of the developed tool. The main shortcomings of the developed method are revealed, connected with the absence of consideration of factors of influence of features of a transport infrastructure and technological resources within the limits of construction procedure on characteristics of the project. In order to eliminate the identified shortcomings, it is planned to improve the methodology at further stages of the research.
EXTENSÃO UNIVERSITÁRIA NA ODONTOLOGIA COMO UMA EXPERIÊNCIA EM SAÚDE
Authors: Silva André Rodrigo Justino da
Published: July 2020

A extensão universitária tem função de articular ensino e pesquisa, além de aproximar a universidade da comunidade. Desse modo, o objetivo deste estudo é relatar a prática extensionista, em creches municipais, através de um projeto de extensão do curso de odontologia da Universidade Federal de Campina Grande. Foram desenvolvidas atividades em três escolas públicas de ensino infantil por acadêmicos de odontologia e seus professores com 290 crianças em idade pré-escolar, seus pais e professores, promovendo saúde bucal através de atividades lúdicas, rodas de conversa e questionários. A partir das ações observaram-se melhorias nas técnicas de escovação das crianças, além de motivação para melhoria de hábitos delas e dos pais, entretanto percebeu-se alto consumo de açúcar pelas crianças. Os professores das instituições demonstraram pouco conhecimento sobre práticas de saúde bucal e suas formas de abordagem, além de afirmarem falta de incentivo proveniente dos órgãos superiores para realização de atividades sobre o tema no ambiente escolar. Portanto, há necessidade de aumento do incentivo da prática extensionista para melhoria das condições de saúde bucal de crianças e seus familiares, com atenção especial às escolas e pré-escolas públicas localizadas em regiões de baixo nível socioeconômico.