bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparative study on properieties of hydroxyapatite prepared from bovine and dromedary bone
Authors: ghedjemis amina , ayech Riad , BENOUADAH Ali
Published: August 2021

The recovery of agro-food waste is at the heart of the challenges of the 21st century, in this context that this research work comes. A biomaterial is prepared from a significant resource such as dromedary bone and bovine bone by heat treatment at different temperatures and characterized by physico-chemical techniques in order to have the effect of bone type on the physico-chemical properties of hydroxyapatite. The results of FTIR and DRX show the removal of all organic matter and the production of pure hydroxyapatite without any additional phase for both bone types. Analyzes by SEM and laser particle size analyzer show that the particle size of hydroxyapatite is increased with increasing temperature. From the results of XRF, bone type is a direct effect on the concentration of hydroxyapatite compounds in hydroxyapatite prepared from dromedary bone compared to hydroxyapatite prepared from bovine bone.
Long COVID - the physical and mental health of children and non-hospitalised young people 3 months after SARS-CoV-2 infection; a national matched cohort study (The CLoCk) Study.
Authors: Stephenson Terence , Stephenson Terence , Pereira Snehal Pinto , Shafran Roz , De Stavola Bianca , Rojas Natalia , McOwat Kelsey , Simmons Ruth , Zavala Maria , O’Mahoney Lauren , Chalder Trudie , Crawley Esther , Ford Tamsin , Harnden Anthony , Heyman Isobel , Swann Olivia , Whittaker Liz , Consortium CLoCk Consortium CLoCk , Ladhani Shamez
Published: August 2021

Introduction: We describe post-COVID symptomatology in a national sample of 11-17-year-old children and young people (CYP) with PCR-confirmed SARS-CoV-2 infection compared to test-negative controls.Methods and analysis: A cohort study of test-positive (n=3,065) and age-, sex- and geographically-matched test-negative CYP (n=3,739) completed detailed questionnaires 3 months post-test.Results: At PCR-testing, 35.4% of test-positives and 8.3% of test-negatives had any symptoms whilst 30.6% and 6.2%, respectively, had 3+ symptoms. At 3 months post-testing, 66.5% of test-positives and 53.3% of test-negatives had any symptoms, whilst 30.3% and 16.2%, respectively, had 3+ symptoms. Latent class analysis identified two classes, characterised by “few” or “multiple” symptoms. This latter class was more frequent among test-positives, females, older CYP and those with worse pre-test physical and mental health.Discussion: Test-positive CYP had a similar symptom profile to test-negative CYP but with higher prevalence of single and, particularly, multiple symptoms at PCR-testing and 3 months later.
Statistical analysis plan for an international, double-blind, randomized controlled clinical trial on the use of phantom motor execution as a treatment for phantom limb pain.
Authors: Lendaro Eva , Earley Eric J. , Catalan Max Ortiz
Published: August 2021

Background Phantom limb pain (PLP) is a chronic condition that can greatly diminish quality of life. Purposeful control over the phantom limb activates of the affected neural circuitry and leads to dissolution of the pathological relationship linking sensorimotor and pain processing (which gives rise to PLP). An international, double-blind, randomized controlled clinical trial (RCT) on the use of phantom motor execution (PME) as a treatment for PLP is currently undertaken, where PME is compared to active placebo. Methods and design Sixty-seven subjects suffering from PLP in upper or lower limbs are randomly assigned in 2:1 ratio to PME or phantom motor imagery (PMI) interventions respectively. Subjects allocated to either treatment receive 15 interventions and are exposed to the same VR-AR environments using the same device. The only difference between interventions is whether phantom movements are performed (PME) or just imagined (PMI). Results The primary outcome of the study is to examine whether 15 sessions of PME can induce a greater PLP relief, compared to PMI. The secondary objectives are to examine whether 15 sessions of PME provide a greater improvement on different aspects related to PLP compared to PMI, such as pain duration, pain intensity as measured by other metrics and the patient’s own impression about the effect of treatment. Long-term retention of treatment benefits will be assessed as change in all the variables (both primary and secondary) between baseline and follow-up timepoints (at one-, three- and six-months post treatment). Conclusion This manuscript serves as the formal statistical analysis plan (version 1.0) for the international, double-blind, randomized controlled clinical trial on the use of phantom motor execution as a treatment for phantom limb pain. The statistical analysis plan was completed on 3 August 2021. Trial registration number NCT03112928. SAP version Version: 1.0 Date: 2021/08/03 Protocol Version This document has been written based on information contained in the study protocol published in [1], in July 2018. SAP Revisions Not applicable
Light-driven oxygen evolution from water oxidation: TiO2 engineering in the performance of the immobilised photocatalysts
Authors: Sampaio Maria J. , Yu Zhipeng , Lopes Joana C. , Tavares Pedro B. , Silva Cláudia G. , Liu Lifeng , Faria Joaquim L.
Published: August 2021

Calcination treatments in the range of 500–900 ºC of TiO2 synthesised by the sol-gel resulted in materials with variable physicochemical (i.e., optical, specific surface area, crystallite size and crystalline phase) and morphological properties. The photocatalytic performance of the prepared materials was evaluated in the oxygen evolution reaction (OER) following UV-LED irradiation of aqueous solutions containing iron ions as sacrificial electron acceptors. The highest activity for water oxidation was obtained with the photocatalyst thermally treated at 700 ºC (TiO2-700). Photocatalysts with larger anatase to rutile ratio of the crystalline phases and higher surface density of oxygen vacancies (defects) displayed the best performance in OER. The oxygen defects at the photocatalyst surface have proven to be responsible for the enhanced photoactivity, acting as important active adsorption sites for water oxidation. Seeking technological application, water oxidation was accomplished by immobilising the photocatalyst with the highest OER rate measured under the established batch conditions (TiO2-700). Experiments operating under continuous mode revealed a remarkable efficiency for oxygen production, exceeding 12% of the apparent quantum efficiency (AQE) at 385 nm (UV-LED system) compared to the batch operation mode.
Educational Technology Competency Framework: Defining a Community of Practice Across Canada
Authors: Sonnenberg Lyn , Onan Arif , Archibald Douglas
Published: August 2021

Post-secondary institutions need clarity regarding what their educational technology teams can offer. Educational technology is not simply a hammer that can be quickly utilized, but rather an instrument that needs to be tuned for each unique learning context. Using a modified Delphi approach, we validated an educational technology framework that highlights the necessary capabilities, competencies, and example activities needed in higher education across Canada, which moves away from traditional roles and responsibilities. This framework captures the need for teams to educate, collaborate, design, develop, administer, and lead within their institutions. It also highlights the revealed desire and need to create broader communities of practice and collaborations between various institutions. Educational technology teams themselves, when functioning optimally, will not only transform the academic experience for learners and teaching faculty, but they will ultimately shape the direction of higher education’s teaching and learning.
Editorial
Authors: Cleveland-Innes Martha , Lakhal Sawsen
Published: August 2021

As the COVID-19 pandemic slowly subsides, this journal, which focuses on learning and technology, is overwhelmed with article submissions. The education response to the health and safety requirements of the pandemic included the use of new technologies for learning in many education spaces and geographic places. Suffice to say that the interest in the topic of technology-enabled learning has increased exponentially. Over the last year we have received more than double our usual number of submissions. While an exciting transformation in the field of education, we were unprepared for the influx. Many of our authors and reviewers work in some sector of education, as does the editorial team of the journal. Currently caught up with our response to submissions, there continues to be some delay in securing agreement and support from reviewers, many of whom are still dealing with the demand on education to continue near-normal delivery. As interest and expertise in the field develops, and with hope that the pandemic continues to subside, we expect to see these recent time delays diminish over the next year.
The role of placental immunological, pro-inflammatory, and proteolytic factors in the process of fetal membrane expulsion in mares
Authors: RAPACZ-LEONARD ANNA
Published: August 2021

The placenta is a temporary organ necessary for prenatal life and the development of eutherian mammals. In the mare it should be expelled within 3 hours of expulsion of the fetus. A delay in its separation can have serious or fatal consequences for mares. The preparation of the mare for the expulsion of the fetal membranes most likely requires immunological interactions between placental antigen and the mare’s immune system. The latest results suggest that fetal membrane retention is related to disorders of inflammatory processes in the placenta, including a lower expression of prostaglandin endoperoxide synthase-2. These disorders in the pro-inflammatory response and disturbances in the activity of the proteolytic enzyme network may lead to adhesion between the fetal and the maternal parts of the placenta. The resulting adhesion may cause the fetal membranes to be thicker and less flexible, making them difficult to expel. Understanding the mechanism of placental retention may contribute to the development of effective methods to prevent and treat this condition.
Predation pressure of the grey wolf (Canis lupus L. 1758) on wild, domestic and companion animals in Poland
Authors: DZIKI-MICHALSKA KATARZYNA , TAJCHMAN KATARZYNA
Published: August 2021

The aim of this study was to determine the predation pressure of the grey wolf (Canis lupus) on wild ungulate populations and the relationship between the size of the grey wolf population and the number of confirmed kills of livestock and companion animals in Poland over eight hunting seasons from 2011/2012 to 2018/2019. There is a positive and complete relationship between the increasing wolf population and the number of confirmed deer kills. The size of the wolf population in Poland was compared to the size of domestic and companion animal population and the number of specimens that fell prey to the grey wolf. It was demonstrated that as the wolf population in Poland increases, the number of confirmed kills of farm and companion animals rises. It seems rational to take steps aimed at mitigating this problem as soon as possible. It is necessary to consider implementation of an integrated protection system that involves culling and employing available methods to deter wolves from attacking grazing herds.
Combating multidrug-resistant Staphylococcus aureus isolated from camel milk with extracts of Eucalyptus globulus and Calotropis procera, and their potential role in modulation of resistance to beta-lactam drugs
Authors: ALI MAHBOOB , AVAIS MUHAMMAD , JAMAL MUHAMMAD AMEEN , IJAZ MUHAMMAD , CHAUDHRY MAMOONA , AQIB AMJAD ISLAM , KHAN MUMTAZ ALI , AHMED MEHTAB , HASNI MUHAMMAD SAJID , HAMEED SAJID , HAQ INZMAM UL
Published: August 2021

This study aimed to evaluate the efficacy of Eucalyptus globulus and Calotropis procera against MDRSA and their potential role in modulating resistance to beta-lactam drugs. The study used a total of n = 263 camel milk samples as well as aqueous and ethanolic extracts of both plants from the Cholistan Desert and the Suleman Mountain Range in Pakistan. Different concentrations of the two plants (25, 12.6, 6.25, and 3.125 mg/mL), either alone or in combination with each other, were tested against MDRSA by well diffusion and broth dilution methods. Further, the efficacy of both plant extracts in combination with cefotaxime (30 μg) and ampicillin (1 μg) was also tested. The results indicate that the zone of inhibition (ZOI) of E. globulus alone and in combination with C. procera was nearly 3 times as large as that of C. procera. Ethanolic extracts of the two plants plants, alone or in combination with either of the two antibiotics, had a significantly (P <0.05) larger ZOI than their aqueous extracts did. Further, the modulation factor for the drugs in combination with ethanolic extracts of both plants exhibited strong synergy (P <0.05), and the minimum inhibitory concentration (MIC) of ethanolic extracts was also significantly lower than that of the aqueous extract of either plant (P <0.05). In conclusion, the ethanolic extracts of E. globulus and C. procera alone and in combination are effective against MDRSA and can play a role in modulating resistance to beta-lactam antibiotics.
El “nuevo periodismo” al rescate de la credibilidad mediática
Authors: Del Valle del Peral Ricardo
Published: August 2021

El presente artículo parte de la idea de que un “Nuevo Periodismo” sustentado en el interés público, la transparencia, la calidad y el ejercicio ético de la profesión puede contribuir a recuperar parte de la credibilidad perdida por las empresas informativas. En pocas palabras, se analizan a continuación algunos factores de credibilidad que parecen indispensables para que los medios, los periodistas y sus noticias superen el bajo nivel de confianza que le dispensan los receptores. Las propuestas aquí vertidas derivan del análisis realizado por investigadores de la comunicación, periodistas y receptores.
La crisis nacional y el fracaso de la comunicación política en México
Authors: Esteinou Madrid Javier
Published: August 2021

Estudio de un período de evolución histórica en que se creó un país más depauperado, entristecido, frustrado, amedrentado, encolerizado y consumista, pero disfrazado ante nuestros ojos mediante un “lavado de imagen” mercadológico del poder en turno que lo presenta como una sociedad “progresista”, “globalizada”, “postmoderna”, “civilizada” y “alegre”, que avanza por los parámetros ejemplares del crecimiento mundial fijados por la OCDE. Pese a la enorme abundancia de recursos informativos, financieros y logísticos con los que contaron los partidos políticos para convencer a los ciudadanos, el proceso de comunicación se caracterizó por la existencia de una acentuada pobreza de contenidos, superficialidad de diagnósticos, ausencia de propuestas, famélica discusión de proyectos, evasión de alternativas de solución, uso de las “reglas del circo” para obtener votos, etc. y no a la reflexión sobre los graves desafíos que tiene que resolver el país en el presente y futuro.
AVANÇOS RECENTES NA SÍNTESE DO REMDESIVIR, MOLNUPIRAVIR (EIDD-2801) E TENOFOVIR: MOLÉCULAS PROMISSORAS NO TRATAMENTO DA COVID-19
Authors: Braga Taniris , dos Santos Juliana , de Castro Pedro , Amarante Giovanni
Published: August 2021

RECENT ADVANCES IN THE SYNTHESIS OF REMDESIVIR, MOLNUPIRAVIR (EIDD-2801) AND TENOFOVIR: PROMISING MOLECULES IN THE TREATMENT OF COVID-19. The search for new treatments to contain the Covid-19 pandemic has highlighted the importance of nucleoside antivirals, such as Remdesivir, Tenofovir and Molnupiravir. Over the last two years, these molecules have been intensely investigated as promising alternatives against SARS-CoV-2 virus. Considering the increasingly demand for those substances, several research groups are intensely investigating synthetic developments in order to obtain these nucleoside derivatives and their intermediates in a fast, efficient and accessible manner. In this context, this review aims to in-depth present the recent advances concerning the preparation of Remdesivir, Tenofovir and Molnupiravir. Aspects involving differences in the starting materials and reagents, as well as the advantages and limitations of each protocol would be carefully disclosed. Moreover, the use of synthetic tools, such as flow chemistry, organocatalysis and biocatalysis, would also be detailed. Finally, this review also presents aspects involving the scale-up of these transformations, including discussions about stereo- and diastereoselectivity, as well as product isolation details. In summary, an overview of the existing synthetic strategies for these active pharmaceutical ingredients (APIs) are presented.
ATIVIDADE INIBITÓRIA DE PESTICIDAS PIRETROIDES SOBRE A GLUTATIONA S-TRANSFERASE
Authors: Ribeiro Eliane , Badea Mihaela , Ribeiro Danilo , Costa Andressa , dos Santos Djanira , Marques Paulo , Nunes Gilvanda
Published: August 2021

INHIBITORY ACTIVITY OF PYRETHROID PESTICIDES ON GLUTATHIONE S-TRANSFERASE. Glutathione S-transferase (GST) is one of the enzymes used to evaluate the effects caused by environmental contaminants. The aim of this work was to study the effects of four pyrethroid compounds (allethrin, cypermethrin, deltamethrin and fenpropathrin) on the catalytic activity of GST and to estimate the potential for environmental contamination in silico of these insecticides. Spectrophotometric analyses showed that the activity of the GST enzyme was inhibited by the four pesticides, with the values for the inhibition constant (Ki) varying from 0.12 to 20 µmol L-1, with the following order of inhibition from the highest to the lowest Ki value: deltamethrin > cypermethrin > allethrin > fenpropathrin. They presented a competitive and non-competitive inhibition mechanism depending on the compound. The IC50 values (concentration that inhibits 50% of the enzyme activity) showed the insecticide deltamethrin with greater inhibitory capacity, since it reduced the activity of the GST enzyme by half, even though it was in a lower concentration in relation to the other analyzed compounds. The in silico evaluation indicated the possibility of most of the insecticides contaminating the surface waters (rivers and lakes) adhered to the suspended sediment, but did not show any potential for contamination of groundwater through leaching.
Reusable rainwater quality at the Ikorodu area of Lagos, Nigeria: impact of first-flush and household treatment techniques
Authors: John Chukwuemeka K. , Pu Jaan H. , Moruzzi Rodrigo , Pandey Manish , Md. Azamathulla Hazi
Published: August 2021

Water scarcity is a huge problem in Africa, and hence rainwater becomes a crucial water source for fulfilling basic human needs. However, less attention has been given by African countries to the effectiveness of common rainwater treatments to ensure the population's health. This study investigates the impact of different household treatment techniques (HHTTs), i.e. treatments by chlorine, boiling, alum, and a combination of alum and chlorine, on its storage system using a case study at the Ikorodu area of Lagos state, which is a rural area in Nigeria. The first-flush quality has been particularly studied here, where the microbial reduction through its practice has been examined from five different roofs. One of the investigated roofs was from a residential building, and four were constructed for the purpose of this study. In this study, the physical parameters (i.e. total suspended solids and turbidity) and the microbial parameters (i.e. total coliform and Escherichia coli) of the collected rainwater have been investigated. From the results, it has been observed that: (1) the water quality at the free phase zone is better than that at the tank's bottom; (2) the combination of chlorine and alum gives the best rainwater quality after comparing the application of different HHTTs; and (3) a reduction of about 40% from the original contaminant load occurs in every 1 mm diversion.
Metabolomic Profiling of Exhaled Breath Condensate and Plasma/
Serum in Chronic Obstructive Pulmonary Disease
Authors: Fuschillo Salvatore , Paris Debora , Tramice Annabella , Ambrosino Pasquale , Palomba Letizia , Maniscalco Mauro , Motta Andrea
Published: August 2021

Chronic obstructive pulmonary disease (COPD) is an increasing cause of global
morbidity and mortality, with poor long-term outcomes and chronic disability. COPD is
a condition with a wide spectrum of clinical presentations, with different phenotypes being
identified even among patients with comparable degrees of airflow limitation. Considering
the burden of COPD in terms of social and economic costs, in recent years growing
attention has been given to the need for more personalized approaches and patienttailored
rehabilitation programs. In this regard, the systematic analysis of metabolites in
biological matrices, namely metabolomics, may become an essential tool in phenotyping
diseases. Through the identification and quantification of the small molecules produced
during biological processes, metabolomic profiling of biological samples has thus been
proposed as an opportunity to identify novel biomarkers of disease outcome and treatment
response. Exhaled breath condensate (EBC) and plasma/serum are fluid pools, which can
be easily extracted and analyzed. In this review, we discuss the potential clinical applications
of the metabolomic profiling of EBC and plasma/serum in COPD.
Dimeric Drugs
Authors: Nudelman Abraham
Published: August 2021

This review intends to summarize the structures of an extensive number of
symmetrical-dimeric drugs, having two monomers, linked via a bridging entity emphasizing
the versatility of biologically active substances reported to possess dimeric structures.
The major number of these compounds consists of anticancer agents, antibiotics/
antimicrobials, and anti-AIDS drugs. Other symmetrical-dimeric drugs include antidiabetics,
antidepressants, analgesics, anti-inflammatories, drugs for the treatment of Alzheimer’s
disease, anticholesterolemics, estrogenics, antioxidants, enzyme inhibitors, anti-
Parkinsonians, laxatives, antiallergy compounds, cannabinoids, etc. Most of the articles
reviewed do not compare the activity/potency of the dimers to that of their corresponding
monomers. Only in limited cases, various suggestions have been made to justify the unexpectedly
higher activity of the dimers vs. that of the corresponding monomers. These
suggestions include statistical effects, the presence of dimeric receptors, binding of a dimer
to two receptors simultaneously, and others. It is virtually impossible to predict
which dimers will be preferable to their respective monomers, or which linking bridges
will lead to the most active compounds. It is expected that the extensive variety of substances
mentioned, and the assortment of their biological activities should be of interest to
academic and industrial medicinal chemists.
Recent Insights into the Nutritional Antioxidant Therapy in Prevention and Treatment of Diabetic Vascular Complications: A Comprehensive Review
Authors: Beeraka Narasimha M. , Tomilova Irina K. , Batrak Galina A. , Zhaburina Maria V. , Nikolenko Vladimir N. , Sinelnikov Mikhail Y. , Mikhaleva Liudmila M.
Published: August 2021

:

Diabetes mellitus (DM) and DM-induced vascular complications are significant global healthcare problems, causing a decrease in patient quality of life. The main reason for the disability and mortality of patients is rapidly progressing micro-and macroangiopathies. Currently, free radical oxidation is recognized as one of the main mechanisms in the development of DM and associated complications. Under normal physiological conditions, the level of free radicals and antioxidant defense capabilities is balanced. However, imbalance occurs between the antioxidant defense system and pro-oxidants during chronic hyperglycemia and may invoke the formation of excess free radicals, leading to activation of lipid peroxidation and accumulation of highly toxic products of free radical oxidation. This is accompanied by varying degrees of insulin deficiency and insulin resistance in DM patients. Simultaneously with the activation of free radical generation, a decrease in the activity of antioxidant defense factors (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, vitamins C and E) and an acceleration of diabetic complications are seen. Therefore, we hypothesize that antioxidants may play a positive role in the treatment of DM patients to prevent DM-induced vascular complications. However, this has not been sufficiently studied. In this review, we discuss recent insights into the potential underlying mechanisms of oxidative stress-induced diabetic complications and the implications of antioxidants in mitigation of DM-induced vascular complications.
The use of Pseudotyped Coronaviruses for the Screening of Entry
Inhibitors: Green Tea Extract Inhibits the Entry of SARS-CoV-1, MERSCoV,
and SARS-CoV-2 by Blocking Receptor-spike Interaction
Authors: Joseph Jeswin , Karthika Thankamani , Das Valiyathara Rajan Akshay , Raj Victor Stalin
Published: August 2021

Background:

Coronaviruses (CoVs) infect a wide range of animals and birds. Their tropism is primarily determined by the ability of the spike protein to bind to a host cell surface receptor. The ongoing outbreak of SARS-CoV-2 inculcates the need for the development of effective intervention strategies.

Objectives:

In this study, we aim to produce pseudotyped coronaviruses of SARS-CoV-1, MERS-CoV, and SARS-CoV-2 and show its applications, including virus entry, neutralization, and screening of entry inhibitors from natural products.

Methods:

Here, we generated VSV-based pseudotyped coronaviruses (CoV-PVs) for SARS-CoV-1, MERS-CoV, and SARS-CoV-2. Recombinant spike proteins of SARS-CoV-1, MERS-CoV, and SARS-CoV-2 were transiently expressed in HEK293T cells followed by infection with recombinant VSV. High titer pseudoviruses were harvested and subjected to distinct validation assays, which confirms the proper spike pseudotyping. Further, specific receptor-mediated entry was confirmed by antibody neutralization and soluble form of receptor inhibition assay on Vero E6 cells. Next, these CoV-PVs were used for screening of antiviral activity of natural products such as green tea and Spirulina extract.

Results:

Here, we generated VSV-based pseudotyped coronaviruses (CoV-PVs) for SARS-CoV-1, MERS-CoV, and SARS-CoV-2. Recombinant spike proteins of SARS-CoV-1, MERS-CoV, and SARS-CoV-2 were transiently expressed in HEK293T cells followed by infection with recombinant VSV. High titer pseudoviruses were harvested and subjected to distinct validation assays, which confirms the proper spike pseudotyping. Further, specific receptor-mediated entry was confirmed by antibody neutralization and soluble form of receptor inhibition assay on Vero E6 cells. Next, these CoV-PVs were used for screening of antiviral activity of natural products such as green tea and Spirulina extract.

Conclusion:

In summary, we demonstrated that pseudotyped viruses are an ideal tool for studying viral entry, quantification of neutralizing antibodies, and screening of entry inhibitors in a BSL-2 facility. Moreover, green tea might be a promising natural remedy against emerging coronaviruses.
The Production of Biodegradable Polymers-medium-chain-length Polyhydroxyalkanoates
(mcl-PHA) in Pseudomonas putida for Biomedical Engineering
Applications
Authors: Ene Nicoleta , Soare Vladu Mariana-Gratiela , Lupescu Irina , Ionescu Ana-Despina , Vamanu Emanuel
Published: August 2021

Background:

Polyhydroxyalkanoates (PHAs) are bacteria-synthesized biopolymers under imbalanced growth conditions. These biopolymers are acknowledged as potential biomaterials for future applications because of their characteristics of biocompatibility and biodegradability, and ability to be produced rapidly, and strong functionality of mechanical resistance. This article aims to perform microbial fermentation using the Pseudomonas putida strain to identify the quantity of biopolymers, particularly of the medium-chain-length (mcl-PHA) polyhydroxyalkanoates, based on the type and quantity of the added precursors (glucose and fatty acids).

Methods:

To understand the microbial interaction and the mechanism involved in PHA biosynthesis, several methods were employed and microbial biomass was obtained using the Pseudomonas putida strain capable of producing PHA. The polymer production by acetone extraction was analyzed using the Soxhlet method, while the biopolymer purification was done via the methanol-ethanol treatment, after which the biomass estimation was done through spectrophotometric analysis. This was followed by measuring the dry weight of the cells and quantification of the biopolymer produced using the gas chromatography method (GC).

Results:

The highest PHA yield was obtained using the octanoic (17 mL in 2000 mL medium) and hexanoic acids (14 mL in 2000 mL medium) as the precursors. As a result, the octanoic acid - octanoic acid, heptanoic acid – nonanoic acid, and octanoic acid - hexanoic acid were identified as the different precursors that supported the quantity of PHA obtained.

Conclusion:

Among the 4 types of structurally related substrates, the Pseudomonas putida ICCF 319 strain showed a preference for the C8 sublayer for the biosynthesis of the elastomeric PHAs composed predominantly of more C8 monomers than the C6 and C10.
Medicinal properties of some Dendrobium orchids – A review
Authors: Ramesh T. , Koperuncholan M. , Praveena R. , Ganeshkumari K. , Vanithamani J. , Muruganantham P. , Renganathan P.
Published: August 2021

Orchids are known for their aesthetic qualities, and they are often used as decorative items in homes, offices, and public places. While most people admire them for their good looks, others have found practical uses for them. Since a long time ago, people from various parts of the world have used orchids for medicinal purposes. However, the use of orchids in medicine has declined over the years because not enough research has been done to determine their effectiveness and adverse effects.
Purification, characterization and application of bromelain from Ananas comosus
Authors: Bhagavathy S. , Pushya K. , Gayathridevi R. , Jeniffer J.
Published: August 2021

Bromelain is a major protease, isolated from pineapple (Ananas comosus). Bromelain is accumulated in the entire plant to a different extent and properties depending on its source. In the present study, Bromelain was extracted from all parts of pineapple using sodium citrate buffer. Bromelain was filtered, centrifuged and used for further studies. After the determination of protease activity and protein content, the Core and Pulp extract of A.comosus was chosen using gelatin as the substrate. The Bromelain was purified by precipitation and dialysis. Then SDS-PAGE was performed in order to determine the molecular size of the obtained protein. Then the effectiveness of Bromelain as an anti-browning agent, extracted and purified from pineapple Core and Pulp was determined. The study showed that Bromelain is a better anti-browning agent when compared with some of the available commercial anti-browning agents. Further, the application of Bromelain was tested by stain removal, compared to the positive control, the ability of stain-removing property for the produced enzyme was observed to be good. Immobilized Bromelain prepared using calcium alginate beads and its stability and characters were noted.
Влияние сильного межузельного кулоновского взаимодействия на топологические свойства сверхпроводящей нанопроволоки
Authors: Шустин М.С. , Аксенов С.В.
Published: August 2021

For superconducting nanowire with the pairing of extended s-type symmetry, Rashba spin-orbit interaction in a magnetic field, the influence of strong intersite charge correlations on single-particle Majorana excitations is analyzed. This problem is investigated on the basis of the density matrix renormalization group numerical method. It is shown that with an increase in the repulsion intensity of electrons located at the neighboring sites, two subbands emerge in the lower Hubbard band of the open system. Based on calculations of the Majorana polarization and degeneracy of the entanglement spectrum, it was found that a topologically nontrivial phase with one edge state survives at the edge of each of the subbands where the concentration of electrons or holes is minimal.
Механизмы термостимулированной люминесценции в УФ-облученных нанотрубках диоксида циркония
Authors: Петренёв И.А. , Вохминцев А.С. , Старовойтова С.А. , Вайнштейн И.А.
Published: August 2021

A nanotubular layer of zirconium dioxide was synthesized with anodic oxidation. Curves of spectrally resolved thermostimulated luminescence were studied in the 390-550 nm range after 300 nm UV irradiation. Energetic and kinetic parameters of thermostimulated luminescence curves were estimated. The mechanism of thermally-activated processes involving intrinsic lattice defects is proposed.
Влияние кислорода и паров воды на структурные превращения в наногранулированных композитах (Co-=SUB=-40-=/SUB=-Fe-=SUB=-40-=/SUB=-B-=SUB=-20-=/SUB=-)-=SUB=-x-=/SUB=-(LiNbO-=SUB=-3-=/SUB=-)-=SUB=-100-x-=/SUB=-
Authors: Ситников А.В. , Бабкина И.В. , Калинин Ю.Е. , Никонов А.Е. , Копытин М.Н. , Шакуров А.Р. , Погребной Д.С. , Рыльков В.В.
Published: August 2021

Influence of oxygen and water vapor in vacuum chamber during the deposition process of (Co40Fe40B20)x(LiNbO3)100-x thin film nanocomposites on electrical properties has been investigated. A significant growth in the electrical resistivity of (Co40Fe40B20)x(LiNbO3)100-x nanocomposites has been established with an increase in reactive gases partial pressure (oxygen and water vapor). It has been found, that the recrystallization temperature of composites deposited in argon atmosphere also increases with metallic phase concentration. While the recrystallization temperature of (Co40Fe40B20)x(LiNbO3)100-x nanocomposites sinthesized in mixed atmosphere of Ar with the reactive gases (oxygen or water vapor) decreases due to increase of the heterogeneous structure oxidation.
Особенности поляризации пьезоэлектрической керамики на основе ниобата натрия
Authors: Малышкина О.В. , Али М. , Иванова А.И. , Чернышова И.А. , Мамаев Д.В.
Published: August 2021

Comparative studies of the pyroelectric properties and structural features of sodium niobate and sodium-potassium niobate ceramics obtained under different technological conditions for the synthesis of sodium niobate have been carried out. X-ray phase analysis revealed the existence of an additional phase with the chemical formula NaNb10O18 in sodium niobate ceramic samples that do not exhibit ferroelectric properties. It is shown that the temperature conditions for the synthesis of the sodium niobate material determine the nature of the macroscopic polarization of the samples of both pure sodium niobate and sodium-potassium niobate.
Зависимость подвижности носителей заряда в гибридных наноструктурах на интерфейсе графена с молекулярными ионами от их зарядовой плотности
Authors: Бутко А.В. , Бутко В.Ю. , Кумзеров Ю.А.
Published: August 2021

A.V. Butko, V.Y. Butko, Y.A.Kumzerov
Ioffe Institute, 194021, St. Petersburg, Russia

Hybrid nanostructures with large interface between nanostructural elements play an important role in the modern electronics. Among these nanostructures are hybrid nanostructures formed at the interface of graphene with ensembles of molecular ions in the solution gated Graphene Field Effect Transistors (GFETs) that are promising for chemical and biological sensor fabrication. Therefore investigation of interfacial effects in electrical transport in these systems is interesting. This work is a theoretical study of dependence of the charge carrier mobility (µ) in these nanostructures on density of the interfacial molecular ions (Nii). We show that dependence µ~1/(Nii)^1/2 obtained in free charge carrier model with short range scattering in case of the weak interaction between the charge carriers and the interfacial ions is in agreement with experimental transistor characteristics obtained at the high gate voltages.
Chloe for COVID-19: Evolution of an Intelligent Conversational Agent to Address Infodemic Management Needs During the COVID-19 Pandemic
Authors: Siedlikowski Sophia , Noël Louis-Philippe , Moynihan Stephanie Anne , Robin Marc
Published: August 2021

There is an unprecedented demand for infodemic management due to rapidly evolving information about the novel COVID-19 pandemic. This viewpoint paper details the evolution of a Canadian digital information tool, Chloe for COVID-19, based on incremental leveraging of artificial intelligence techniques. By providing an accessible summary of Chloe’s development, we show how proactive cooperation between health, technology, and corporate sectors can lead to a rapidly scalable, safe, and secure virtual chatbot to assist public health efforts in keeping Canadians informed. We then highlight Chloe’s strengths, the challenges we faced during the development process, and future directions for the role of chatbots in infodemic management. The information presented here may guide future collaborative efforts in health technology in order to enhance access to accurate and timely health information to the public.
Prevalence of SARS-CoV-2 Infection in Children by Antibody Detection in Saliva: Protocol for a Prospective Longitudinal Study (Coro-Buddy)
Authors: Pinilla Yudi T , Friessinger Evelyn , Griesbaum Johanna Marie , Berner Lilith , Heinzel Constanze , Elsner Käthe , Fendel Rolf , Held Jana , Kreidenweiss Andrea
Published: August 2021

Background

The world has been confronted with the COVID-19 pandemic for more than one year. Severe disease is more often found among elderly people, whereas most young children and adolescents show mild symptoms or even remain asymptomatic, so that infection might be undiagnosed. Therefore, only limited epidemiological data on SARS-CoV-2 infection in children and young adults are available.

Objective

This study aims to determine the prevalence of SARS-CoV-2 antibodies in children from the city of Tübingen, Germany, and to measure the incidence of new cases over 12 months.

Methods

SARS-CoV-2 antibodies will be measured in saliva as a surrogate for a previous SARS-CoV-2 infection. Children will be sampled at their preschools, primary schools, and secondary schools at three time points: July 2020, October to December 2020, and April to July 2021. An adult cohort will be sampled at the same time points (ie, adult comparator group). The saliva-based SARS-CoV-2–antibody enzyme-linked immunosorbent assay will be validated using blood and saliva samples from adults with confirmed previous SARS-CoV-2 infections (ie, adult validation group).

Results

The first study participant was enrolled in July 2020, and recruitment and enrollment continued until July 2021. We have recruited and enrolled 1850 children, 560 adults for the comparator group, and 83 adults for the validation group. We have collected samples from the children and the adults for the comparator group at the three time points. We followed up with participants in the adult validation group every 2 months and, as of the writing of this paper, we were at time point 7. We will conduct data analysis after the data collection period.

Conclusions

Infection rates in children are commonly underreported due to a lack of polymerase chain reaction testing. This study will report on the prevalence of SARS-CoV-2 infections in infants, school children, and adolescents as well as the incidence change over 12 months in the city of Tübingen, Germany. The saliva sampling approach for SARS-CoV-2–antibody measurement allows for a unique, representative, population-based sample collection process.

Trial Registration

ClinicalTrials.gov NCT04581889; https://clinicaltrials.gov/ct2/show/NCT04581889

International Registered Report Identifier (IRRID)

DERR1-10.2196/27739
Characterization of Global Research Trends and Prospects on Single-Cell Sequencing Technology: Bibliometric Analysis (Preprint)
Authors: Wang Quan , Yang Ke-Lu , Zhang Zhen , Wang Zhu , Li Chen , Li Lun , Tian Jin-Hui , Ye Ying-Jiang , Wang Shan , Jiang Ke-Wei
Published: August 2021

BACKGROUND

As single-cell sequencing technology has been gradually introduced, it is essential to characterize global collaboration networks and map development trends over the past 20 years.

OBJECTIVE

The aim of this paper was to illustrate collaboration in the field of single-cell sequencing methods and explore key topics and future directions.

METHODS

Bibliometric analyses were conducted with CiteSpace and VOSviewer software on publications prior to November 2019 from the Web of Science Core Collection about single-cell sequencing methods.

RESULTS

Ultimately, we identified 2489 records, which were published in 495 journals by 14,202 authors from 1970 institutes in 61 countries. There was a noticeable increase in publications in 2014. The United States and high-income countries in Europe contributed to most of the records included. Harvard University, Stanford University, Karolinska Institutes, Peking University, and the University of Washington were the biggest nodes in every cluster of the collaboration network, and SA Teichmann, JC Marioni, A Regev, and FC Tang were the top-producing authors. Keywords co-occurrence analysis suggested applications in immunology as a developing research trend.

CONCLUSIONS

We concluded that the global collaboration network was unformed and that high-income countries contributed more to the rapidly growth of publications of single-cell sequencing technology. Furthermore, the application in immunology might be the next research hotspot and developmental direction.
Skin, Hair, and Nail Supplements Advertised on Instagram: A Survey of Selected Posts (Preprint)
Authors: Zamil Dina Hani , Ameri May , Fu Shangyi , Abughosh Ferris Munzer , Katta Rajani
Published: August 2021

BACKGROUND

Teens and young adults increasingly utilize the internet and social media for health information. Skin, hair, and nail supplements are commonly advertised on social media sites. Such dermatological supplements may be pharmacologically active and pose risk for adverse effects. Instagram is a popular social media platform, used by influencers to promote products.

OBJECTIVE

To evaluate the popularity, ingredients, marketing, and health claims of Instagram posts advertising skin, hair, and nail supplements.

METHODS

Instagram was searched between April and May 2021 for posts with the hashtags “skin supplement[s],” “nail supplement[s],” and “hair supplement[s].” Inclusion and exclusion criteria were applied until 100 posts from March 2021 were collected. Posts were evaluated for popularity metrics, ingredients, health claims, marketing strategies, and endorsements.

RESULTS

Posts had a median of 30 likes and 0 comments, with only 4% of posts made by verified accounts. Only 1% of posts contained a visible Supplement Facts label. Nearly 1/5 of posts made no mention of what ingredients are contained in the supplement. Approximately 1/3 of posts mentioned vitamins and 1/4 mentioned minerals without specifying which ones. The most common health claim was “make skin glow” and hair loss/growth and acne were the conditions mentioned most frequently. 22% of posts featured influencers, 6% of posts included a giveaway, and 7% of posts included a promo code.

CONCLUSIONS

Dermatological supplements on Instagram contained various active ingredients and made far-reaching health claims, addressing skin conditions as well as arthritis, cardiac issues, and weight loss. The FDA does not regulate the safety of dietary supplements, nor evaluate the validity of such claims. Ingredients such as vitamin A found in posts often did not include the dose, which is important in evaluating teratogenic risk. More generally, many supplement posts failed to show a clear image of the Supplement Facts label, as well as which vitamins and minerals the supplement contains. Other potentially dangerous ingredients included saw palmetto and biotin. Posts endorsed by an influencer or with a greater number of likes or comments may lead to greater consumer trust in the product, though only one influencer identified in this study was a board-certified dermatologist. As such, social media represents an underutilized tool by dermatologists, which could be useful in debunking health myths. To accurately counsel patients, who may already retrieve health information from Instagram, it is important for the dermatology community to be familiar with the marketing and claims made by products on social media.
THE JOURNEY OF JOURNAL ON MATHEMATICS EDUCATION: FROM LOCAL TO GLOBAL
Authors: Zulkardi Zulkardi , Prahmana Rully Charitas Indra
Published: August 2021

One of indicators to determine the quality of a journal can be observed from how many indexing institutions recognized it nationally and globally, such as Sinta, Scopus, and ScimagoJR. Furthermore, the rank of a journal in the indexing institution will add more value to the reputation of a journal. However, few journal editors are willing to share their experiences in managing a journal, from the beginning to getting recognition at the international level. Thus, this article describes the journey of the first journal in the mathematics education field from Indonesia called the Journal on Mathematics Education (JME), which is globally recognized and indexed on Scopus. JME's journey to gain global recognition is narrated in a structured way, starting from the history of journal formation, recognition at the local level, strategies to get authors from various countries, promotional activities to get credit, until finally getting a global position. In addition, this article also describes many contributions from world-class Mathematics Education researchers who have published their research results in JME. Finally, this article also describes the position of JME at national and international levels based on the data of several indexing institutes and JME's future targets.
Corporate, social, political connections and corporate governance: A review
Authors: Faizabad Arash , Refakar Mohammad , Champagne Claudia
Published: August 2021

Considering the important role of connections in corporate governance quality, this review paper has investigated the effectiveness of corporate, social, and political connections on corporate governance practices. In general, the findings of this research show that networking activities in various forms positively and negatively affect corporate governance practices. As far as corporate connections are concerned, there is no consensus on the relationship between interlocked boards and firm performance. Moreover, interlocking boards are positively associated with the propagation of some governance malpractices such as earnings manipulation and options backdating. Regarding social connections, the evidence provides contradictory results regarding the effects of social ties on CEO compensation and firm performance. Finally, as for political connections, the findings related to the impact of political connections on corporate decisions and firm value are mixed. Furthermore, politically connected firms pay lower taxes; have more access to credit markets; and enjoy governmental contracts. Additionally, in some cases, political ties are positively associated with corrupt activities