bluuebunny/crossref_metadata_2025 huggingface dataset:
Colorings of (r, r)-Uniform, Complete, Circular, Mixed Hypergraphs
Authors: Newman Nicholas , Voloshin Vitaly
Published: April 2021

In colorings of some block designs, the vertices of blocks can be thought of as hyperedges of a hypergraph H that can be placed on a circle and colored according to some rules that are related to colorings of circular mixed hypergraphs. A mixed hypergraph H is called circular if there exists a host cycle on the vertex set X such that every edge (C- or D-) induces a connected subgraph of this cycle. We propose an algorithm to color the (r,r)-uniform, complete, circular, mixed hypergraphs for all feasible values with no gaps. In doing so, we show χ(H)=2 and χ¯(H)=n−s or n−s−1 where s is the sieve number.
Methodology for Analysis and Quantitative Evaluation of Teaching Quality in University Subjects
Authors: Arenas Reina José , Cano-Moreno Juan , Sánchez Martínez Francisca , Islán Marcos Manuel
Published: April 2021

This work describes a general method to quantitatively evaluate the teaching quality of a subject by taking into account the main factors that intervene in the educational process (companies, teachers, students, etc.). The proposed methodology, based on the concatenation of the four “Houses of Quality” of the “Quality Function Deployment” (QFD), is applicable to any university subject. Through an integrated matrix development of the four quality houses, a vector has been obtained (q4→) that integrates in its definition the entire teaching process of a university subject. Therefore, from this vector, a representative parameter of the teaching quality has been defined, namely, the “Teaching Value”, which globally quantifies the teaching of a university subject. Likewise, and in a complementary manner, the overall effectiveness of teaching has been established (ηglobal), which is defined as the geometric mean of the product of the efficiencies of the four Houses of Quality and allows the determination of the current performance of teaching and its margin for potential improvement. In particular, the use of the proposed methodology for the engineering course “Project Management” has allowed the teaching quality of this course to be determined (64.2 Megapoints with an efficiency of 48.60%).
Systematic Evaluation Model for Developing Sustainable World-Class Universities: An East Asian Perspective
Authors: Zhang Meng-Chen , Zhu Bo-Wei , Huang Chao-Meng , Tzeng Gwo-Hshiung
Published: April 2021

Due to the unbalance between Asian and Western countries in terms of higher education development and pressure from global competition, universities in several East Asian countries have striven to become world-class universities (WCUs) by actively assessing themselves using various global ranking systems and subsequently investing in key performance indicators. Numerous scholars have suggested that for these East Asian catch-up universities (EACUs), independently improving the elements related to high-weight indicators could produce short-term increases in ranking performance; however, this approach is not conducive to sustainable development. In addition, little is currently understood regarding sustainable development strategies for developing EACUs into WCUs. This study proposes a systematic evaluation model for self-assessment and the creation of strategies to transform EACUs into sustainable WCUs. The fuzzy Delphi method was used to determine criteria for a new evaluation framework, and the decision-making trial and evaluation laboratory method was employed to construct the influential relationships among the criteria. Two cases were then selected to demonstrate the superiority of the model for creating sustainable development strategies for EACUs. This study provides a systematic perspective and a useful tool for decision-makers at EACUs to achieve sustainable development goals.
On Generalized Lucas Pseudoprimality of Level k
Authors: Andrica Dorin , Bagdasar Ovidiu
Published: April 2021

We investigate the Fibonacci pseudoprimes of level k, and we disprove a statement concerning the relationship between the sets of different levels, and also discuss a counterpart of this result for the Lucas pseudoprimes of level k. We then use some recent arithmetic properties of the generalized Lucas, and generalized Pell–Lucas sequences, to define some new types of pseudoprimes of levels k+ and k− and parameter a. For these novel pseudoprime sequences we investigate some basic properties and calculate numerous associated integer sequences which we have added to the Online Encyclopedia of Integer Sequences.
On Similarity Measures for Stochastic and Statistical Modeling
Authors: Makris Konstantinos , Vonta Ilia , Karagrigoriou Alex
Published: April 2021

In this work, our goal is to present and discuss similarity techniques for ordered observations between time series and non-time dependent data. The purpose of the study was to measure whether ordered observations of data sets are displayed at or close to, the same time points for the case of time series and with the same or similar frequencies for the case of non-time dependent data sets. A simultaneous time pairing and comparison can be achieved effectively via indices, advanced indices and the associated index matrices based on statistical functions of ordered observations. Hence, in this work we review some previously defined standard indices and propose new advanced dimensionless indices and the associated index matrices which are both easily interpreted and provide efficient comparison of the series involved. Furthermore, the proposed methodology allows the analysis of data with different units of measurement as the indices presented are dimensionless. The applicability of the proposed methodology is explored through an epidemiological data set on influenza-like-illness (ILI). We finally provide a thorough discussion on all parameters involved in the proposed indices for practical purposes along with examples.
Estrogenic Effects of Extracts and Isolated Compounds from Belowground and Aerial Parts of Spartina anglica
Authors: Lee Sullim , Kim Geum Jin , Kwon Hyukbean , Nam Joo-Won , Baek Ji Yun , Shim Sang Hee , Choi Hyukjae , Kang Ki Sung
Published: April 2021

Menopause, caused by decreases in estrogen production, results in symptoms such as facial flushing, vaginal atrophy, and osteoporosis. Although hormone replacement therapy is utilized to treat menopausal symptoms, it is associated with a risk of breast cancer development. We aimed to evaluate the estrogenic activities of Spartina anglica (SA) and its compounds and identify potential candidates for the treatment of estrogen reduction without the risk of breast cancer. We evaluated the estrogenic and anti-proliferative effects of extracts of SA and its compounds in MCF-7 breast cancer cells. We performed an uterotrophic assay using an immature female rat model. Among extracts of SA, belowground part (SA-bg-E50) had potent estrogenic activity. In the immature female rat model, the administration of SA-bg-E50 increased uterine weight compared with that in the normal group. Among the compounds isolated from SA, 1,3-di-O-trans-feruloyl-(-)-quinic acid (1) had significant estrogenic activity and induced phosphorylation at serine residues of estrogen receptor (ER)α. All extracts and compounds from SA did not increase MCF-7 cell proliferation. Compound 1 is expected to act as an ERα ligand and have estrogenic effects, without side effects, such as breast cancer development.
Pharmacokinetics and Pharmacodynamics of a Depolymerized Glycosaminoglycan from Holothuria fuscopunctata, a Novel Anticoagulant Candidate, in Rats by Bioanalytical Methods
Authors: Liu Shuang , Zhang Taocui , Sun Huifang , Lin Lisha , Gao Na , Wang Weili , Li Sujuan , Zhao Jinhua
Published: April 2021

dHG-5 (Mw 5.3 kD) is a depolymerized glycosaminoglycan from sea cucumber Holothuria fuscopunctata. As a selective inhibitor of intrinsic Xase (iXase), preclinical study showed it was a promising anticoagulant candidate without obvious bleeding risk. In this work, two bioanalytical methods based on the anti-iXase and activated partial thromboplastin time (APTT) prolongation activities were established and validated to determine dHG-5 concentrations in plasma and urine samples. After single subcutaneous administration of dHG-5 at 5, 9, and 16.2 mg/kg to rats, the time to peak concentration (Tmax) was at about 1 h, and the peak concentration (Cmax) was 2.70, 6.50, and 10.11 μg/mL, respectively. The plasma elimination half-life(T1/2β) was also about 1 h and dHG-5 could be almost completely absorbed after s.c. administration. Additionally, the pharmacodynamics of dHG-5 was positively correlated with its pharmacokinetics, as determined by rat plasma APTT and anti-iXase method, respectively. dHG-5 was mainly excreted by urine as the unchanged parent drug and about 60% was excreted within 48 h. The results suggested that dHG-5 could be almost completely absorbed after subcutaneous injection and the pharmacokinetics of dHG-5 are predictable. Studying pharmacokinetics of dHG-5 could provide valuable information for future clinical studies.
In Vitro Prebiotic and Anti-Colon Cancer Activities of Agar-Derived Sugars from Red Seaweeds
Authors: Yun Eun , Yu Sora , Kim Young-Ah , Liu Jing-Jing , Kang Nam , Jin Yong-Su , Kim Kyoung
Published: April 2021

Numerous health benefits of diets containing red seaweeds or agar-derived sugar mixtures produced by enzymatic or acid hydrolysis of agar have been reported. However, among various agar-derived sugars, the key components that confer health-beneficial effects, such as prebiotic and anti-colon cancer activities, remain unclear. Here, we prepared various agar-derived sugars by multiple enzymatic reactions using an endo-type and an exo-type of β-agarase and a neoagarobiose hydrolase and tested their in vitro prebiotic and anti-colon cancer activities. Among various agar-derived sugars, agarotriose exhibited prebiotic activity that was verified based on the fermentability of agarotriose by probiotic bifidobacteria. Furthermore, we demonstrated the anti-colon cancer activity of 3,6-anhydro-l-galactose, which significantly inhibited the proliferation of human colon cancer cells and induced their apoptosis. Our results provide crucial information regarding the key compounds derived from red seaweeds that confer beneficial health effects, including prebiotic and anti-colon cancer activities, to the host.
Elastofibroma Dorsi, a Rare Condition, with Challenging Diagnosis. Case Report and Literature Review
Authors: Neagoe Octavian , Faur Cosmin Ioan , Ionică Mihaela , Baderca Flavia , Folescu Roxana , Gurgus Daniela , Zamfir Carmen Lăcrămioara , Motoc Andrei , Grigoraș Mirela Loredana , Mazilu Octavian
Published: April 2021

Elastofibroma dorsi (ED) is known as a particular clinical and biological entity. We report a case of a bilateral elastofibroma dorsi (ED) in a 65-year-old female who presented to the Department of General and Oncologic Surgery of Emergency Clinical Municipal Hospital Timisoara, Romania. The patient was symptomatic on the right side, presenting pain in the interscapulothoracic region associated with a variable tumoral mass, dependent on the position of the right arm. Imaging studies revealed a well-defined, bilateral tumoral mass with alternation of the muscular and fatty tissue. The initial diagnosis of lipoma was taken into consideration based on the CT scan and clinical findings. Surgical excision of the right subscapular tumor was performed without any postoperative complications. Microscopic examination of hematoxylin and eosin, Masson’s trichrome, and orcein stained slides revealed the diagnosis of ED. Considering the high rate of reported postoperative complications and the asymptomatic presentation of the contralateral subscapular mass, the patient underwent clinical and imagistic monitoring for the contralateral tumor. Due to its rare nature, ED is a difficult preoperative diagnosis that can, however, be suggested by its specific location and may require an accurate histopathological examination for a final diagnosis.
Enantioselective Mixed Matrix Membranes for Chiral Resolution
Authors: Choi Hwa-Jin , Ahn Yun-Ho , Koh Dong-Yeun
Published: April 2021

Most pharmaceuticals are stereoisomers that each enantiomer shows dramatically different biological activity. Therefore, the production of optically pure chemicals through sustainable and energy-efficient technology is one of the main objectives in the pharmaceutical industry. Membrane-based separation is a continuous process performed on a large scale that uses far less energy than the conventional thermal separation process. Enantioselective polymer membranes have been developed for chiral resolution of pharmaceuticals; however, it is difficult to generate sufficient enantiomeric excess (ee) with conventional polymers. This article describes a chiral resolution strategy using a composite structure of mixed matrix membrane that employs chiral fillers. We discuss several enantioselective fillers, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), zeolites, porous organic cages (POCs), and their potential use as chiral fillers in mixed matrix membranes. State-of-the-art enantioselective mixed matrix membranes (MMMs) and the future design consideration for highly efficient enantioselective MMMs are discussed.
Hybrid Ceramic Membranes for the Removal of Pharmaceuticals from Aqueous Solutions
Authors: Radeva Jenny , Roth Anke Gundula , Göbbert Christian , Niestroj-Pahl Robert , Dähne Lars , Wolfram Axel , Wiese Jürgen
Published: April 2021

Layer-by-Layer (LbL) technology was used to coat alumina ceramic membranes with nanosized polyelectrolyte films. The polyelectrolyte chains form a network with nanopores on the ceramic surface and promote the rejection of small molecules such as pharmaceuticals, salts and industrial contaminants, which can otherwise not be eliminated using standard ultrafiltration methods. The properties and performance of newly developed hybrid membranes are in the focus of this investigation. The homogeneity of the applied coating layer was investigated by confocal fluorescence microscopy and scanning transmission electron microscopy (STEM). Properties such as permeability, bubble point, pore size distribution and Zeta potential were determined for both pristine and LbL coated membranes using various laboratory tests. Subsequently, a thorough comparison was drawn. The charging behavior at solid-liquid interface was characterized using streaming potential techniques. The retention potential was monitored by subjecting widely used pharmaceuticals such as diclofenac, ibuprofen and sulfamethoxazol. The results prove a successful elimination of pharmaceutical contaminants, up to 84% from drinking water, by applying a combination of polyelectrolyte multilayers and ceramic membranes.
Mass Transfer Analysis of Air-Cooled Membrane Distillation Configuration for Desalination
Authors: Cong Shuo , Miao Qingxiu , Guo Fei
Published: April 2021

It has been proposed that the air-cooled configuration for air gap membrane distillation is an effective way to simplify the system design and energy source requirement. This offers potential for the practical applications of membrane distillation on an industrial scale. In this work, membrane distillation tests were performed using a typical water-cooled membrane distillation (WCMD) configuration and an air-cooled membrane distillation (ACMD) configuration with various condensing plates and operating conditions. To increase the permeate flux of an ACMD system, the condensing plate in the permeate side should transfer heat to the atmosphere more effectively, such as using a more thermally conductive plate, adding fins, or introducing forced convection air flow. Importantly, a practical mass transfer model was proposed to describe the ACMD performance in terms of permeate flux. This model can be simplified by introducing specific correction values to the mass transfer coefficient of a WCMD process under the same conditions. The two factors relate to the capacity (B) and the efficiency (σ), which can be considered as the characteristic factors of a membrane distillation (MD) system. The experimental results are consistent with the theoretical estimations based on this model, which can be used to describe the performance of an MD process.
Diabetic Pathophysiology Enhances Inflammation during Extracorporeal Membrane Oxygenation in a Rat Model
Authors: Fujii Yutaka , Abe Takuya , Ikegami Kikuo
Published: April 2021

Systemic inflammatory responses in patients undergoing extracorporeal membrane oxygenation (ECMO) contribute significantly to ECMO-associated morbidity and mortality. In recent years, the number of type 2 diabetes mellitus patients has increased, and the number of these patients undergoing ECMO has also increased. Type 2 diabetes mellitus is a high-risk factor for complications during ECMO. We studied the effects of ECMO on inflammatory response in a diabetic rat ECMO model. Twenty-eight rats were divided into 4 groups: normal SHAM group (normal rats: n = 7), diabetic SHAM group (diabetic rats: n = 7), normal ECMO group (normal rats: n = 7), and diabetic ECMO group (diabetic rats: n = 7). We measured the plasma levels of cytokines, tumor necrosis factor-α, and interleukin-6. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), creatinine (Cr), and liver-type fatty acid binding protein (L-FABP) were examined in the rat cardiopulmonary bypass model to ascertain organ damage. In addition, the lung wet-to-dry weight (W/D) ratio was measured as an index of pulmonary tissue edema. A pathologic evaluation of kidneys was conducted by hematoxylin-eosin (HE) and periodic-acid-methenamine-silver (PAM) staining. In the diabetic ECMO group, levels of cytokines, AST, ALT, LDH, and L-FABP increased significantly, reaching a maximum at the end of ECMO in comparison with other groups (p < 0.05). In addition, hematoxylin-eosin and periodic acid-methenamine-silver staining of renal tissues showed marked injury in the ECMO group (normal ECMO and diabetic ECMO groups). Furthermore, when the normal ECMO and diabetic ECMO groups were compared, severe organ injury was seen in the diabetic ECMO group. There was remarkable organ injury in the diabetic ECMO group. These data demonstrate that diabetes enhances proinflammatory cytokine release, renal damage, and pulmonary edema during ECMO in an animal model.
Capacitor Electrical Discharge Consolidation of Metallic Powders—A Review
Authors: Aranda Rosa María , Ternero Fátima , Lozano-Pérez Sergio , Montes Juan Manuel , Cuevas Francisco G.
Published: April 2021

Manufacturing metallic materials from elemental or alloyed powders is an option in many industrial processes. Nevertheless, the traditional powder metallurgy processing including furnace sintering is at times detrimental for the microstructure attained in the powders. Alternative sintering processes based on the use of electricity and the energy obtained by the Joule effect in powder particles can be quick enough to avoid microstructural changes. In particular, when the energy is stored in a capacitor and then discharged, the heating process is extremely quick, lasting milliseconds or even microseconds. This process, generally known as electrical discharge consolidation, has been applied to a wide variety of metallic materials, easily preserving the original microstructure of the powders. Both porous or homogeneous and highly densified material can be obtained, and without losing the desired properties of the consolidated material. A general overview of the process and applications, as well as the results obtained by different research groups around the world, have been reviewed in this manuscript.
Fabrication, Microstructure, and Microhardness at High Temperature of In Situ Synthesized Ti3Al/Al2O3 Composites
Authors: Binh Do Thanh , Huy Tran Duc , Thuong Tran Viet , Binh Duong Ngoc , Miyamoto Hiroyuki
Published: April 2021

In this study, in situ Al2O3-reinforced Ti3Al composite was fabricated after 8 h of milling and sintering at 850 °C. A mixture of TiO2 and Al powders were mechanically milled in a planetary mill, cold-compacted and sintered under a protected argon atmosphere. The microstructure and microhardness of the Al2O3 embedded in Ti3Al matrix at both room and elevated temperature has been reported. The obtained results showed that the Ti3Al/Al2O3 composite was successfully synthesized via the powder metallurgy method. Ti3Al phase and Al2O3 particles were formed after 8 h of milling and sintering at 850 °C. The microstructure formation of round and uniformly distributed Al2O3 particles in the Ti3Al matrix improved the microhardness of the composite. At normal temperature, the microhardness of the material measured about 11.5 GPa. Meanwhile, at elevated temperatures, from 600 to 800 °C, it decreased from 4.18 GPa to 3.15 GPa.
Characterization of Titanium Surface Modification Strategies for Osseointegration Enhancement
Authors: Kim Jinyoung , Lee Hyun , Jang Tae-Sik , Kim DongEung , Yoon Chang-Bun , Han Ginam , Kim Hyoun-Ee , Jung Hyun-Do
Published: April 2021

As biocompatible metallic materials, titanium and its alloys have been widely used in the orthopedic field due to their superior strength, low density, and ease of processing. However, further improvement in biological response is still required for rapid osseointegration. Here, various Ti surface-treatment technologies were applied: hydroxyapatite blasting, sand blasting and acid etching, anodic oxidation, and micro-arc oxidation. The surface characteristics of specimens subjected to these techniques were analyzed in terms of structure, elemental composition, and wettability. The adhesion strength of the coating layer was also assessed for the coated specimens. Biocompatibility was compared via tests of in vitro attachment and proliferation of pre-osteoblast cells.
Recent Developments in Laser Welding of Aluminum Alloys to Steel
Authors: Wallerstein Daniel , Salminen Antti , Lusquiños Fernando , Comesaña Rafael , García Jesús del Val , Rodríguez Antonio Riveiro , Badaoui Aida , Pou Juan
Published: April 2021

The development of high-performance dissimilar aluminum–steel joints is necessary to promote the feasibility of multi-material design and lightweight manufacturing. However, joining aluminum to steel is a challenging task mainly due to the formation of brittle intermetallic compounds (IMC) at the joint interface. Laser welding is considered a very promising joining process for dissimilar materials, although its application in industry is still limited by the insufficient mechanical performance of the joints. The present paper aims to give a comprehensive review of relevant recent research work on laser joining of aluminum to steel, contributing to highlighting the latest achievements that could boost acceptance of laser joining of dissimilar materials by the modern industries. To this end, the most important challenges in laser joining of aluminum to steel are presented, followed by recent approaches to overcome these challenges, the state-of-art of comprehension of IMC formation and growth, and the different strategies to minimize them.
Recent Advances and Applications of Passive Harmonic RFID Systems: A Review
Authors: Mondal Saikat , Kumar Deepak , Chahal Premjeet
Published: April 2021

Harmonic Radio Frequency Identification (RFID) systems have attracted significant interest over the last decade as it provides many benefits over the conventional RFID systems. Harmonic RFID is desired over conventional RFID systems due to reduced self-jamming, location accuracy from dual frequency, and higher phase noise immunity. In a harmonic RFID system, the tag receives instructions from the reader at an RF carrier frequency and replies back at the harmonic of the RF frequency. A nonlinear element consuming very low power at the tag is required to generate the harmonic carrier for the battery-less system. In this review article, a detailed contrast between conventional and harmonic RFID systems is presented. This is followed by different circuit design techniques to generate harmonics and integration techniques to form a fully operable passive harmonic RFID tag. Also, a wide range of applications, especially sensor integration with harmonic RFID’s, along with the future trends are presented.
A Novel Biofilm Model System to Visualise Conjugal Transfer of Vancomycin Resistance by Environmental Enterococci
Authors: Conwell Michael , Dooley James S. G. , Naughton Patrick J.
Published: April 2021

Enterococci and biofilm-associated infections are a growing problem worldwide, given the rise in antibiotic resistance in environmental and clinical settings. The increasing incidence of antibiotic resistance and its propagation potential within enterococcal biofilm is a concern. This requires a deeper understanding of how enterococcal biofilm develops, and how antibiotic resistance transfer takes place in these biofilms. Enterococcal biofilm assays, incorporating the study of antibiotic resistance transfer, require a system which can accommodate non-destructive, real-time experimentation. We adapted a Gene Frame® combined with fluorescence microscopy as a novel non-destructive platform to study the conjugal transfer of vancomycin resistance in an established enterococcal biofilm.A multi-purpose fluorescent in situ hybridisation (FISH) probe, in a novel application, allowed the identification of low copy number mobile elements in the biofilm. Furthermore, a Hoechst stain and ENU 1470 FISH probe identified Enterococcus faecium transconjugants by excluding Enterococcus faecalis MF06036 donors. Biofilm created with a rifampicin resistant E. faecalis (MW01105Rif) recipient had a transfer efficiency of 2.01 × 10−3; double that of the biofilm primarily created by the donor (E. faecalis MF06036). Conjugation in the mixed enterococcal biofilm was triple the efficiency of donor biofilm. Double antibiotic treatment plus lysozyme combined with live/dead imaging provided fluorescent micrographs identifying de novo enterococcal vancomycin resistant transconjugants inside the biofilm. This is a model system for the further study of antibiotic resistance transfer events in enterococci. Biofilms promote the survival of enterococci and reduce the effectiveness of drug treatment in clinical settings, hence giving enterococci an advantage. Enterococci growing in biofilms exchange traits by means of horizontal gene transfer, but currently available models make study difficult. This work goes some way to providing a non-destructive, molecular imaging-based model system for the detection of antibiotic resistance gene transfer in enterococci.
Screening a Spliced Leader-Based Symbiodinium microadriaticum cDNA Library Using the Yeast-Two Hybrid System Reveals a Hemerythrin-Like Protein as a Putative SmicRACK1 Ligand
Authors: Islas-Flores Tania , Galán-Vásquez Edgardo , Villanueva Marco A.
Published: April 2021

The dinoflagellate Symbiodiniaceae family plays a central role in the health of the coral reef ecosystem via the symbiosis that establishes with its inhabiting cnidarians and supports the host metabolism. In the last few decades, coral reefs have been threatened by pollution and rising temperatures which have led to coral loss. These events have raised interest in studying Symbiodiniaceae and their hosts; however, progress in understanding their metabolism, signal transduction pathways, and physiology in general, has been slow because dinoflagellates present peculiar characteristics. We took advantage of one of these peculiarities; namely, the post-transcriptional addition of a Dino Spliced Leader (Dino-SL) to the 5′ end of the nuclear mRNAs, and used it to generate cDNA libraries from Symbiodinium microadriaticum. We compared sequences from two Yeast-Two Hybrid System cDNA Libraries, one based on the Dino-SL sequence, and the other based on the SMART technology (Switching Mechanism at 5′ end of RNA Transcript) which exploits the template switching function of the reverse transcriptase. Upon comparison of the performance of both libraries, we obtained a significantly higher yield, number and length of sequences, number of transcripts, and better 5′ representation from the Dino-SL based library than from the SMART library. In addition, we confirmed that the cDNAs from the Dino-SL library were adequately expressed in the yeast cells used for the Yeast-Two Hybrid System which resulted in successful screening for putative SmicRACK1 ligands, which yielded a putative hemerythrin-like protein.
Fungal Diversity of Selected Habitat Specific Cynorkis Species (Orchidaceae) in the Central Highlands of Madagascar
Authors: Yokoya Kazutomo , Jacob Alison S. , Zettler Lawrence W. , Kendon Jonathan P. , Menon Manoj , Bell Jake , Rajaovelona Landy , Sarasan Viswambharan
Published: April 2021

About 90% of Cynorkis species are endemic to the biodiversity hotspot of Madagascar. This terrestrial habitat-specific genus received little study for fungal diversity to support conservation. We evaluated the diversity of culturable fungi of 11 species and soil characteristics from six sites spanning a >40 km radius in and along the region’s inselbergs. Peloton-forming fungi were grown in vitro from root/protocorm slices and positively identified using DNA sequencing. The fungal diversity was then correlated with soil pH, NO3-N, P, and K. All species harbored either putative mycorrhizal associates in the Rhizoctonia complex or Hypocreales fungi. Tulasnella Operational Taxonomic Units (OTUs) were most prevalent in all soil types while Serendipita OTUs were found in species inhabiting granite/rock outcrops in moist soil (seepage areas). Most Cynorkis species were present in soil with low NO3-N and P levels with diversity of mycorrhizal fungi inversely correlated to NO3-N levels. Of the different orchid life stages sampled, only one species (Cynorkis fastigiata) yielded putative mycorrhizal fungi from juvenile stages. As diversity of mycorrhizal fungi of Cynorkis spp. was negatively correlated with NO3-N, and majority of the studied taxa were found in soils with low NO3-N and P contents, reintroduction studies must include analysis of N and P in detail. For the first time, we showed that the assemblage of culturable fungi in the roots of habitat-specific species of Cynorkis (Orchidaceae) are intimately tied to specific soil characteristics.
SARS-CoV-2 Disease through Viral Genomic and Receptor Implications: An Overview of Diagnostic and Immunology Breakthroughs
Authors: Inchingolo Alessio Danilo , Inchingolo Angelo Michele , Bordea Ioana Roxana , Malcangi Giuseppina , Xhajanka Edit , Scarano Antonio , Lorusso Felice , Farronato Marco , Tartaglia Gianluca Martino , Isacco Ciro Gargiulo , Marinelli Grazia , D’Oria Maria Teresa , Hazballa Denisa , Santacroce Luigi , Ballini Andrea , Contaldo Maria , Inchingolo Francesco , Dipalma Gianna
Published: April 2021

The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), which is believed to have originated in China towards the end of November 2019, has now spread across the globe, causing a pandemic in 192 countries. The World Health Organization has called it the SARS-CoV-2 pandemic. Rapid dissemination of the virus occurs mainly through the saliva (Flügge’s droplets) and aerosol, together with nasal and lachrymal passages. The literature associated with the recent advancement in terms of rapid diagnostics and SARS-CoV-2 vaccines has thoroughly studied the role of ACE2 receptors and Furin, as well as viral agent access into the host cell and its significant persistence at the level of the oral mucosa, which represents the main access to the virus. The purpose of this review was to underline the processes of SARS-CoV-2 infection mechanisms and novel breakthroughs in diagnostics and vaccines. Different technologies, such as the RT-PCR molecular test and the antigenic test, have been developed to identify subjects affected by the SARS-CoV-2 in order to improve the tracking of infection geographical diffusion. Novel rapid and highly sensitive diagnostic tests has been proposed for the detection of SARS-CoV-2 to improve the screening capability of suspected contagions. The strengthening of the vaccination campaign represents the most effective means to combat the SARS-CoV-2 infection and prevent severe manifestations of the virus—different classes of vaccines have been developed for this purpose. Further attention on the novel SARS-CoV-2 variant is necessary in order to verify the protection efficacy and virulence reduction of the infective agent in the recent vaccine campaign.
Gene Sequencing and Phylogenetic Analysis: Powerful Tools for an Improved Diagnosis of Fish Mycobacteriosis Caused by Mycobacterium fortuitum Group Members
Authors: Mugetti Davide , Tomasoni Mattia , Pastorino Paolo , Esposito Giuseppe , Menconi Vasco , Dondo Alessandro , Prearo Marino
Published: April 2021

The Mycobacterium fortuitum group (MFG) consists of about 15 species of fast-growing nontuberculous mycobacteria (NTM). These globally distributed microorganisms can cause diseases in humans and animals, especially fish. The increase in the number of species belonging to MFG and the diagnostic techniques panel do not allow to clarify their real clinical significance. In this study, biomolecular techniques were adopted for species determination of 130 isolates derived from fish initially identified through biochemical tests as NTM belonging to MFG. Specifically, gene sequencing and phylogenetic analysis were used based on a fragment of the gene encoding the 65 KDa heat shock protein (hsp65). The analyzes made it possible to confirm that all the isolates belong to MFG, allowing to identify the strains at species level. Phylogenetic analysis substantially confirmed what was obtained by gene sequencing, except for six strains; this is probably due to the sequences present in NCBI database. Although the methodology used cannot represent a univocal identification system, this study has allowed us to evaluate its effectiveness as regards the species of MFG. Future studies will be necessary to apply these methods with other gene fragments and to clarify the real pathogenic significance of the individual species of this group of microorganisms.
Genomic Insights into a Colistin-Resistant Uropathogenic Escherichia coli Strain of O23:H4-ST641 Lineage Harboring mcr-1.1 on a Conjugative IncHI2 Plasmid from Egypt
Authors: Zakaria Azza S. , Edward Eva A. , Mohamed Nelly M.
Published: April 2021

The reintroduction of colistin, a last-resort antibiotic for multidrug-resistant pathogens, resulted in the global spread of plasmid-mediated mobile colistin resistance (mcr) genes. Our study investigated the occurrence of colistin resistance among Escherichia coli isolated from patients with urinary tract infections admitted to a teaching hospital in Egypt. Out of 67 isolates, three isolates were colistin-resistant, having a minimum inhibitory concentration of 4 µg/mL and possessing the mcr-1 gene. A double mechanism of colistin resistance was detected; production of mcr-1 along with amino acid substitution in PmrB (E123D and Y358N) and PmrA (G144S). Broth mating experiments inferred that mcr-1 was positioned on conjugative plasmids. Whole-genome sequencing of EC13049 indicated that the isolate belonged to O23:H4-ST641 lineage and to phylogroup D. The mcr-1-bearing plasmid corresponded to IncHI2 type with a notable similarity to other E. coli plasmids previously recovered from Egypt. The unbanned use of colistin in the Egyptian agriculture sector might have created a potential reservoir for the mcr-1 gene in food-producing animals that spread to humans. More proactive regulations must be implemented to prevent further dissemination of this resistance. This is the first characterization of mcr-1-carrying IncHI2:ST4 plasmid recovered from E. coli of a clinical source in Egypt.
DNA Methylation and HPV-Associated Head and Neck Cancer
Authors: Nakagawa Takuya , Kurokawa Tomoya , Mima Masato , Imamoto Sakiko , Mizokami Harue , Kondo Satoru , Okamoto Yoshitaka , Misawa Kiyoshi , Hanazawa Toyoyuki , Kaneda Atsushi
Published: April 2021

Head and neck squamous cell carcinoma (HNSCC), especially oropharyngeal squamous cell carcinoma (OPSCC), has recently been found to be significantly associated with human papillomavirus (HPV) infection. The incidence of OPSCC has been increasing and surpassed the number of cervical cancer cases in the United States. Although HPV-associated OPSCC has a relatively better prognosis than HPV-negative cancer, approximately 20% of HPV-associated HNSCC patients show a poor prognosis or therapeutic response, and the molecular mechanism behind this outcome in the intermediate-risk group is yet to be elucidated. These biological differences between HPV-associated HNSCC and HPV-negative HNSCC are partly explained by the differences in mutation patterns. However, recent reports have revealed that epigenetic dysregulation, such as dysregulated DNA methylation, is a strikingly common pathological feature of human malignancy. Notably, viral infections can induce aberrant DNA methylation, leading to carcinogenesis, and HPV-associated HNSCC cases tend to harbor a higher amount of aberrantly methylated DNA than HPV-negative HNSCC cases. Furthermore, recent comprehensive genome-wide DNA-methylation analyses with large cohorts have revealed that a sub-group of HPV-associated HNSCC correlates with increased DNA methylation. Accordingly, in this review, we provide an overview of the relationship between DNA methylation and HPV-associated HNSCC.
Physiology of Methylotrophs Living in the Phyllosphere
Authors: Yurimoto Hiroya , Shiraishi Kosuke , Sakai Yasuyoshi
Published: April 2021

Methanol is abundant in the phyllosphere, the surface of the above-ground parts of plants, and its concentration oscillates diurnally. The phyllosphere is one of the major habitats for a group of microorganisms, the so-called methylotrophs, that utilize one-carbon (C1) compounds, such as methanol and methane, as their sole source of carbon and energy. Among phyllospheric microorganisms, methanol-utilizing methylotrophic bacteria, known as pink-pigmented facultative methylotrophs (PPFMs), are the dominant colonizers of the phyllosphere, and some of them have recently been shown to have the ability to promote plant growth and increase crop yield. In addition to PPFMs, methanol-utilizing yeasts can proliferate and survive in the phyllosphere by using unique molecular and cellular mechanisms to adapt to the stressful phyllosphere environment. This review describes our current understanding of the physiology of methylotrophic bacteria and yeasts living in the phyllosphere where they are exposed to diurnal cycles of environmental conditions.
Stool Serology: Development of a Non-Invasive Immunological Method for the Detection of Enterovirus-Specific Antibodies in Congo Gorilla Faeces
Authors: Sereme Youssouf , Zarza Sandra Madariaga , Medkour Hacène , Amona Inestin , Fenollar Florence , Akiana Jean , Mezouar Soraya , Orain Nicolas , Vitte Joana , Davoust Bernard , Raoult Didier , Mediannikov Oleg
Published: April 2021

Background: The incidence of poliovirus has been significantly reduced by as much as 99.9% globally. Alongside this, however, vaccine-associated paralytic poliomyelitis has emerged. Previously, our team reported in the Lésio-Louna-Léfini Nature Reserve (Republic of Congo) the presence of a new Enterovirus C (Ibou002) in a male gorilla that was put away because of clinical symptoms of facial paralysis. This new virus, isolated was from the stool samples of this gorilla but also from the excrement of an eco-guardian, is very similar to Coxsackievirus (EV-C99) as well as poliovirus 1 and 2. We hypothesised that these symptoms might be due to poliovirus infection. To test our hypothesis, we developed and optimised a non-invasive immunoassay for the detection of Enterovirus-specific antibodies in gorilla faeces that could be useful for routine serosurveillance in such cases. Methods: In order to assess the potential role of poliovirus infection, we have developed and optimised a protocol, based on the lyophilisation and solubilisation of small volumes of stool extracts from 16 gorilla and 3 humans, to detect specific antibodies by western blot and ELISA. Results: First, total immunoglobulins were detected in the concentrated stool extracts. Specific antibodies were then detected in 4/16 gorilla samples and 2/3 human samples by western blot using both the polio vaccine antigen and the Ibou002 antigen and by ELISA using the polio vaccine antigen. Humoral responses were greater with the Ibou002 antigen. Conclusion: We therefore suggest that this recombinant virus could lead to a polio-like disease in the endangered western lowland gorilla. The development of a non-invasive approach to detect microorganism-specific immunoglobulins from faecal samples opens numerous prospects for application in zoonotic infectious diseases and could revolutionise the screening of animals for important emerging infections, such as Ebola fever, rabies and coronavirus infections.
Rb1.66Cs1.34Tb[Si5.43Ge0.57O15]·H2O, a New Member of the OD-Family of Natural and Synthetic Layered Silicates: Topology-Symmetry Analysis and Structure Prediction
Authors: Topnikova Anastasiia , Belokoneva Elena , Dimitrova Olga , Volkov Anatoly , Deyneko Dina
Published: April 2021

Crystals of new silicate-germanate Rb1.66Cs1.34Tb[Si5.43Ge0.57O15]·H2O have been synthesized hydrothermally in a multi-component system TbCl3:GeO2:SiO2 = 1:1:5 at T = 280 °C and P = 100 atm. K2CO3, Rb2CO3 and Cs2CO3 were added to the solution as mineralizers. The crystal structure was solved using single crystal X-ray data: a = 15.9429(3), b = 14.8407(3), c = 7.2781(1) Å, sp. gr. Pbam. New Rb,Cs,Tb-silicate-germanate consists of a [Si5.43Ge0.57O15]∞∞ corrugated tetrahedral layer combined by isolated TbO6 octahedra into the mixed microporous framework as in synthetic K3Nd[Si6O15]·2H2O, K3Nd[Si6O15] and K3Eu[Si6O15]·2H2O with the cavities occupied by Cs, Rb atoms and water molecules. Luminescence spectrum on new crystals was obtained and analysed. A comparison with the other representatives of related layered natural and synthetic silicates was carried out based on the topology-symmetry analysis by the OD (order-disorder) approach. The wollastonite chain was selected as the initial structural unit. Three symmetrical ways of forming ribbon from such a chain and three ways of further connecting ribbons to each other into the layer were revealed and described with symmetry groupoids. Hypothetical structural variants of the layers and ribbons in this family were predicted.
Experimental Study on Influence of Al2O3, CaO and SiO2 on Preparation of Zinc Ferrite
Authors: Yang Jinlin , Xu Shuo , Zhou Wentao , Zhu Pengyan , Liu Jiguang , Ma Shaojian
Published: April 2021

Gossan ore of sulfide zinc deposit contains abundant zinc, iron, and other metal elements, which is a significant resource with complex components and can be utilized. In this study, a new technology of preparing zinc ferrite from zinc sulfide deposit gossan was proposed. The effects of Al2O3, CaO, and SiO2 in gossan on the formation of zinc ferrite were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and specific surface area and pore size analysis (BET). The results show that the presence of Al2O3 and CaO could hinder the formation of zinc ferrite, while silica had no effect on the formation of zinc ferrite. Under the conditions of the molar ratio of ZnO and Fe2O3 to Al2O3, CaO, and SiO2 of 1:1:1, an activation time of 60 min, and a roasting temperature of 750 °C for 120 min, the products, which had good crystallinity, smooth particle surface, and uniform particle size could be obtained. In addition, compared to the roasted products with Al2O3 and CaO, the specific surface area, pore volume, and pore size of the products with SiO2 were the largest.
Activation of Peroxymonosulfate by Chrysotile to Degrade Dyes in Water: Performance Enhancement and Activation Mechanism
Authors: Dai Ying , Peng Qian , Liu Kun , Tang Xuekun , Zhou Muyang , Jiang Kun , Zhu Binnan
Published: April 2021

An environmentally friendly activation method of peroxymonosulfate (PMS) provides a promising advanced oxidation processes for the degradation of organic wastewater. In this article, chrysotile, extracted from asbestos tailings, was found to be a kind of one-off catalyst relying on hydroxyl groups to activate PMS. Furthermore, the activation performance of the chrysotile had been greatly improved by the mean of calcining at 850 °C (850CC). It is worth mentioning that 850CC could not only realize three effective cycles, but also the mineralization ratio of Rhodamine B (RhB) could be impressively higher than 60%. According to characterization results, it was discovered that the chrysotile had transformed into forsterite with a fibrous morphology after calcination at 850 °C due to the loss of hydroxyl groups and the recombination of silicon, oxygen and magnesium atoms. Besides, the main active species produced by 850CC activating PMS were singlet oxygen and sulfate radicals. Further studies uncovered that PMS was successfully activated by a large number of unsaturated coordination oxygen on 850CC surface, and the activation mechanism was further elucidated. This study provides a new route for the comprehensive utilization of chrysotile and a valuable strategy for the degradation of hazardous organic pollutants in wastewater by PMS activation.
Designing a Virtual Arboretum as an Immersive, Multimodal, Interactive, Data Visualization Virtual Field Trip
Authors: Harrington Maria C. R. , Bledsoe Zack , Jones Chris , Miller James , Pring Thomas
Published: April 2021

This paper describes a virtual field trip application as a new type of immersive, multimodal, interactive, data visualization of a virtual arboretum. Deployed in a game engine, it is a large, open-world simulation, representing 100 hectares and ideal for use when free choice in navigation and high fidelity are required. Although the computer graphics are photorealistic, it is different and unique from other applications that use game art or 2D 360-degree video, because it reflects high information fidelity as a result of the domain expert review, and the integration of geographic information system (GIS) data with drone images. Combined in-game as a data visualization, it is ideal for generating past or future worlds, in addition to representations of the present. Fusing information from many data sources—terrain data, waterbody data, plant inventory, population density data, accurate plant models, bioacoustics, and drone images—its design process and methods could be repeated and used in a wide range of augmented reality (AR) and virtual reality (VR) applications and devices. Results on presence, embodiment, emotions, engagement, and learning are summarized from prior pilot studies for context on use, and are relevant to schools, museums, arboretums, and botanical gardens interested in developing immersive informal learning applications.