bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2
Authors: Lu Renfei , Wu Xiuming , Wan Zhenzhou , Li Yingxue , Jin Xia , Zhang Chiyu
Published: April 2020

COVID-19 has become a major global public health burden, currently causing a rapidly growing number of infections and significant morbidity and mortality around the world. Early detection with fast and sensitive assays and timely intervention are crucial for interrupting the spread of the COVID-19 virus (SARS-CoV-2). Using a mismatch-tolerant amplification technique, we developed a simple, rapid, sensitive and visual reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for SARS-CoV-2 detection based on its N gene. The assay has a high specificity and sensitivity, and robust reproducibility, and its results can be monitored using a real-time PCR machine or visualized via colorimetric change from red to yellow. The limit of detection (LOD) of the assay is 118.6 copies of SARS-CoV-2 RNA per 25 μL reaction. The reaction can be completed within 30 min for real-time fluorescence monitoring, or 40 min for visual detection when the template input is more than 200 copies per 25 μL reaction. To evaluate the viability of the assay, a comparison between the RT-LAMP and a commercial RT-qPCR assay was made using 56 clinical samples. The SARS-CoV-2 RT-LAMP assay showed perfect agreement in detection with the RT-qPCR assay. The newly-developed SARS-CoV-2 RT-LAMP assay is a simple and rapid method for COVID-19 surveillance.
Potential Implications of Interactions between Fe and S on Cereal Fe Biofortification
Authors: Kawakami Yuta , Bhullar Navreet K.
Published: April 2020

Iron (Fe) and sulfur (S) are two essential elements for plants, whose interrelation is indispensable for numerous physiological processes. In particular, Fe homeostasis in cereal species is profoundly connected to S nutrition because phytosiderophores, which are the metal chelators required for Fe uptake and translocation in cereals, are derived from a S-containing amino acid, methionine. To date, various biotechnological cereal Fe biofortification strategies involving modulation of genes underlying Fe homeostasis have been reported. Meanwhile, the resultant Fe-biofortified crops have been minimally characterized from the perspective of interaction between Fe and S, in spite of the significance of the crosstalk between the two elements in cereals. Here, we intend to highlight the relevance of Fe and S interrelation in cereal Fe homeostasis and illustrate the potential implications it has to offer for future cereal Fe biofortification studies.
LncRNAs Act as a Link between Chronic Liver Disease and Hepatocellular Carcinoma
Authors: Kim Young-Ah , Park Kwan-Kyu , Lee Sun-Jae
Published: April 2020

Long non-coding RNAs (lncRNAs) are emerging as important contributors to the biological processes underlying the pathophysiology of various human diseases, including hepatocellular carcinoma (HCC). However, the involvement of these molecules in chronic liver diseases, such as nonalcoholic fatty liver disease (NAFLD) and viral hepatitis, has only recently been considered in scientific research. While extensive studies on the pathogenesis of the development of HCC from hepatic fibrosis have been conducted, their regulatory molecular mechanisms are still only partially understood. The underlying mechanisms related to lncRNAs leading to HCC from chronic liver diseases and cirrhosis have not yet been entirely elucidated. Therefore, elucidating the functional roles of lncRNAs in chronic liver disease and HCC can contribute to a better understanding of the molecular mechanisms, and may help in developing novel diagnostic biomarkers and therapeutic targets for HCC, as well as in preventing the progression of chronic liver disease to HCC. Here, we comprehensively review and briefly summarize some lncRNAs that participate in both hepatic fibrosis and HCC.
The Usage of Smartphone and Mobile Applications from the Point of View of Customers in Poland
Authors: Chmielarz Witold
Published: April 2020

The main objective of this article was to identify the conditions for the use of smartphones and mobile applications in Poland in the second half of 2018. The scope of the present analysis was limited to a selected sample of more than 470 respondents, and it examined the group of the most active users of smartphones and mobile applications. The author adopted the CAWI (computer associated web interview) method, which was previously verified by a randomly selected pilot sample, in his study. The obtained results were compared with the findings of other studies. They indicated that users of smartphones and mobile applications in Poland do not differ in their assessments from users in Europe and around the world. In this context, the key implication for researchers is the identified level of development of the use of smartphones and mobile applications in Poland at the end of 2018. The main limitation of the research was the selection of the research sample, which consisted only of members of the academic community. The scope of this article aimed to fill a gap in terms of the quantitative and qualitative methods that are applied to examine the use of mobile devices and mobile software. At the same time, this study creates the foundations for further research on intercultural differences. It is important to note that the present research sample needs to be extended beyond the academic community for the research results to be fully generalized.
One Archaeology: A Manifesto for the Systematic and Effective Use of Mapped Data from Archaeological Fieldwork and Research
Authors: McKeague Peter , Corns Anthony , Larsson Åsa , Moreau Anne , Posluschny Axel , Van Daele Koen , Evans Tim
Published: April 2020

The Infrastructure for Spatial Information in Europe (INSPIRE) Directive (2007) requires public organisations across Europe to share environmentally-related spatial datasets to support decision making and management of the environment. Despite the environmental focus of INSPIRE, it offers limited guidance for archaeological datasets. Most primary data is created outside, but ultimately curated within, the public sector. As spatial evidence from fieldwork activities is not considered by the Directive, it overlooks a range of barriers to sharing data, such as project-based fieldwork, a lack of data standards, and formatting and licencing variations. This paper submits that these challenges are best addressed through the formalised management of primary research data through an archaeological Spatial Data Infrastructure (SDI). SDIs deliver more efficient data management and release economic value by saving time and money. Better stewardship of archaeological data will also lead to more informed research and stewardship of the historic environment. ARIADNE already provides a digital infrastructure for research data, but the landscape and spatial component has been largely overlooked. However, rather than developing a separate solution, the full potential of spatial data from archaeological research can and should be realised through ARIADNE.
Digital Media: Empowerment and Equality
Authors: Mądra-Sawicka Magdalena , Nord Jeretta Horn , Paliszkiewicz Joanna , Lee Tzong-Ru
Published: April 2020

This study investigated the use of digital media, specifically social media technologies, in the workplace in Taiwan. The data for this study were collected through an online survey. Participants responded to questions asking whether social technologies could be a source of empowerment, leading to equality. Respondents included female and male employees. The findings reveal that both genders use social technology platforms for business support, experience benefits, and believe that these technologies could provide empowerment for success. Detailed results are reported in this paper, including a comparative analysis. The differences between women and men using Facebook and YouTube were significant. Women in Taiwan have a higher awareness of the benefits of social technologies, specifically Facebook, when used for business support and empowerment. This paper reveals a comparison between the attitudes of women and men when using social technologies and investigates the realization of the economic empowerment component.
Differential Foraging of Indigenous and Exotic Honeybee (Apis mellifera L.) Races on Nectar-Rich Flow in a Subtropical Ecosystem
Authors: Alqarni Abdulaziz S.
Published: April 2020

In the subtropics, agricultural activities such as beekeeping are greatly influenced by environmental challenges. In the desert of Central Arabia, honeybees forage on limited prairies that are affected by adverse weather conditions. Bee colonies reduce their field activities during extremely hot-dry-windy weather. This study investigated whether nectar-rich melliferous flora enhance the field activities of two honeybee subspecies, Apis mellifera jemenitica (indigenous) and A. m. carnica (exotic), despite the presence of severe weather conditions. The foraging and pollen-gathering activities of the two subspecies were evaluated on Acacia trees (Acacia gerrardii Benth.), a common subtropical, summery endemic bee plant, in the central desert of the Arabian Peninsula. The native colonies were significantly (p < 0.001) more active foragers than the exotic colonies (109 ± 4 and 49 ± 2 workers/colony/3 min, respectively). Similarly, the native colonies recruited significantly (p ˂ 0.01) more active pollen-gathering bees than the imported colonies (22 ± 1 and 7 ± 1 workers/colony/3 min, respectively). Furthermore, far more food was collected by the indigenous colonies than by the exotic colonies, and a higher portion of all field trips was allocated to pollen gathering by the indigenous bees than by the imported bees. The nectar-rich Acacia trees reduced the negative effects of hot-dry-windy weather. More research on honeybee colonies operating in the subtropical conditions of Central Arabia is needed, especially regarding heat tolerance mechanisms and effects on queen and drone fertility.
Stable Isotope Enrichment (Δ15N) in the Predatory Flower Bug (Orius majusculus) Predicts Fitness-Related Differences between Diets
Authors: Montoro Marta , Jensen Per M. , Sigsgaard Lene
Published: April 2020

Mass rearing of insects, used both as biological control agents and for food and feed, is receiving increasing attention. Efforts are being made to improve diets that are currently in use, and to identify alternative diets, as is the case with the predatory flower bug (Orius majusculus) and other heteropteran predators, due to the high costs of their current diet, the eggs of the Mediterranean flour moth (E. kuehniella). The assessment of alternative diets may include measurements of the predator’s fitness-related traits (development time, weight, etc.), and biochemical analyses such as lipid and protein content in the diet and the insects. However, assessing diet quality via the predator’s fitness-related traits is laborious, and biochemical composition is often difficult to relate to the measured traits. Isotope analysis, previously used for diet reconstruction studies, can also serve as a tool for the assessment of diet quality. Here, the variation in discrimination factors or isotope enrichment (Δ15N and Δ13C) indicates the difference in isotopic ratio between the insect and its diet. In this study, we investigated the link between Δ15N and diet quality in the predatory bug Orius majusculus. Three groups of bugs were fed different diets: Ephestia kuehniella eggs, protein-rich Drosophila melanogaster and lipid-rich D. melanogaster. The isotopic enrichment and fitness-related measurements were assessed for each group. Results show a relation between Δ15N and fitness-related measurements, which conform to the idea that lower Δ15N indicates a higher diet quality.
Monitoring of Urban Landscape Ecology Dynamics of Islamabad Capital Territory (ICT), Pakistan, Over Four Decades (1976–2016)
Authors: Gilani Hammad , Ahmad Sohail , Qazi Waqas Ahmed , Abubakar Syed Muhammad , Khalid Murtaza
Published: April 2020

In the late 1960s, the Islamic Republic of Pakistan’s capital shifted from Karachi to Islamabad, officially named Islamabad Capital Territory (ICT). In this aspect, the ICT is a young city, but undergoing rapid expansion and urbanization, especially in the last two decades. This study reports the measurement and characterization of ICT land cover change dynamics using Landsat satellite imagery for the years 1976, 1990, 2000, 2010, and 2016. Annual rate of change, landscape metrics, and urban forest fragmentation spatiotemporal analyses have been carried out, along with the calculation of the United Nations Sustainable Development Goal (SDG) indicator 11.3.1 Land Consumption Rate to the Population Growth Rate (LCRPGR). The results show consistent increase in the settlement class, with highest annual rate of 8.79% during 2000–2010. Tree cover >40% and <40% canopy decreased at an annual rate of 0.81% and 0.77% between 1976 to 2016, respectively. Forest fragmentation analysis reveals that ‘core forests of >500 acres’ class decreased from 392 km2 (65.41%) to 241 km2 (55%), and ‘patch forest’ class increased from 15 km2 (2.46%) to 20 km2 (4.54%), from 1976 to 2016. The LCRPGR ratio was 0.62 from 1976 to 2000, increasing to 1.36 from 2000 to 2016.
Effect of A Rapid-Cooling Protocol on the Optical and Mechanical Properties of Dental Monolithic Zirconia Containing 3–5 mol% Y2O3
Authors: Kim Hee-Kyung
Published: April 2020

Many attempts have been made to improve the translucency of zirconia in dentistry. The purpose of this study was to evaluate the effect of a rapid-cooling heat treatment on the optical and mechanical properties of dental monolithic zirconia. Zirconia containing 3, 4, and 5 mol% Y2O3 were sintered, sectioned, and polished. The specimens were rapidly cooled from high temperature inducing a diffusionless cubic-to-metastable tetragonal (t’) phase transformation. The changes in L*a*b* color coordinates, translucency parameter (TP), and total transmittance (T%) were measured. Three-point bending strength, Vickers hardness, and indentation fracture toughness tests were performed. Quantitative phase analyses were carried out by X-ray diffraction with Rietveld refinement. Scanning electron microscopy (SEM) images were obtained. With increasing Y2O3 contents, TP and T% values increased while strength and toughness decreased. The Rietveld analysis showed that the amount of t’-phase increased after rapid-cooling and annealed 5Y-partially stabilized zirconia (PSZ) contained the highest amount of t’-phase (64.4 wt%). Rapid-cooling improved translucency but the translucency of annealed 5Y-PSZ did not approach that of lithium disilicate glass-ceramic. Rapid-cooling decreased flexural strength significantly, being 306.1 ± 61.8 MPa for annealed 5Y-PSZ. SEM revealed that grains tended to get larger after rapid-cooling. A rapid-cooling treatment can produce t’-phase which can contribute to an increase in translucency but has a negative effect on the mechanical properties of zirconia.
Characterization of Regulatory and Transporter Genes in the Biosynthesis of Anti-Tuberculosis Ilamycins and Production in a Heterologous Host
Authors: He Jianqiao , Wei Xin , Yang Zhijie , Li Yan , Ju Jianhua , Ma Junying
Published: April 2020

Ilamycins are cyclopeptides with novel structures that have been isolated from different Actinomycetes. They showed strong anti-tuberculosis activity and could serve as important anti-tuberculosis drug leads. The functions of the pre-tailoring and the post-tailoring genes in the biosynthesis of ilamycins have been elucidated, but the functions of the regulatory and transporter genes remain elusive. We reported herein the functions of four genes in ilamycin biosynthetic gene cluster (ila BGC) including two regulatory genes (ilaA and ilaB) and two transporter genes (ilaJ and ilaK) and the heterologous expression of ila BGC. The IlaA and IlaB were unambiguously shown to be negative and positive regulator of ilamycins biosynthesis, respectively. Consistent with these roles, inactivation of ilaA and ilaB (independent of each other) was shown to enhance and abolish the production of ilamycins, respectively. Total yields of ilamycins were enhanced 3.0-fold and 1.9-fold by inactivation of ilaA and overexpression of ilaB compared to those of in the Streptomyces atratus SCSIO ZH16, respectively. In addition, the ila BGC was successfully expressed in Streptomyces coelicolor M1152, which indicated that all biosynthetic elements for the construction of ilamycins were included in the PAC7A6. These results not only lay a foundation for further exploration of ilamycins, but also provide the genetic elements for synthetic biology.
Necrotizing Sialometaplasia and Bulimia: A Case Report
Authors: Salvado Francisco , de Araújo Nobre Miguel , Gomes João , Maia Paulo
Published: April 2020

Bulimia is an eating disorder with a great prevalence in young women. Due to its multifactor ethiology, bulimia has systemic consequences. In the literature, necrotising sialometaplasia is seldom associated with bulimia. Its etiopathogenesis is discussed by several authors; nevertheless, the consensus does not consider the relevance of local trauma associated with induced vomiting. A case of necrotising sialomethaplasia, presented with a single hard palatal ulcer in a bulimic woman is described in the present report. The patient did not present significant systemic laboratorial values, nor physical weight variations, which highlights the relevance of performing a complete medical clinical history when diagnosing this rare pathology.
Benchtop Low-Frequency 60 MHz NMR Analysis of Urine: A Comparative Metabolomics Investigation
Authors: Leenders Justine , Grootveld Martin , Percival Benita , Gibson Miles , Casanova Federico , Wilson Philippe B.
Published: April 2020

Metabolomics techniques are now applied in numerous fields, with the ability to provide information concerning a large number of metabolites from a single sample in a short timeframe. Although high-frequency (HF) nuclear magnetic resonance (NMR) analysis represents a common method of choice to perform such studies, few investigations employing low-frequency (LF) NMR spectrometers have yet been published. Herein, we apply and contrast LF and HF 1H-NMR metabolomics approaches to the study of urine samples collected from type 2 diabetic patients (T2D), and apply a comparative investigation with healthy controls. Additionally, we explore the capabilities of LF 1H-1H 2D correlation spectroscopy (COSY) experiments regarding the determination of metabolites, their resolution and associated analyses in human urine samples. T2D samples were readily distinguishable from controls, with several metabolites, particularly glucose, being associated with this distinction. Comparable results were obtained with HF and LF spectrometers. Linear correlation analyses were performed to derive relationships between the intensities of 1D and 2D resonances of several metabolites, and R2 values obtained were able to confirm these, an observation attesting to the validity of employing 2D LF experiments for future applications in metabolomics studies. Our data suggest that LF spectrometers may prove to be easy-to-use, compact and inexpensive tools to perform routine metabolomics analyses in laboratories and ‘point-of-care’ sites. Furthermore, the quality of 2D spectra obtained from these instruments in half an hour would broaden the horizon of their potential applications.
Towards Predicting Gut Microbial Metabolism: Integration of Flux Balance Analysis and Untargeted Metabolomics
Authors: Kuang Ellen , Marney Matthew , Cuevas Daniel , Edwards Robert A. , Forsberg Erica M.
Published: April 2020

Genomics-based metabolic models of microorganisms currently have no easy way of corroborating predicted biomass with the actual metabolites being produced. This study uses untargeted mass spectrometry-based metabolomics data to generate a list of accurate metabolite masses produced from the human commensal bacteria Citrobacter sedlakii grown in the presence of a simple glucose carbon source. A genomics-based flux balance metabolic model of this bacterium was previously generated using the bioinformatics tool PyFBA and phenotypic growth curve data. The high-resolution mass spectrometry data obtained through timed metabolic extractions were integrated with the predicted metabolic model through a program called MS_FBA. This program correlated untargeted metabolomics features from C. sedlakii with 218 of the 699 metabolites in the model using an exact mass match, with 51 metabolites further confirmed using predicted isotope ratios. Over 1400 metabolites were matched with additional metabolites in the ModelSEED database, indicating the need to incorporate more specific gene annotations into the predictive model through metabolomics-guided gap filling.
First Insights into the Urinary Metabolome of Captive Giraffes by Proton Nuclear Magnetic Resonance Spectroscopy
Authors: Zhu Chenglin , Fasoli Sabrina , Isani Gloria , Laghi Luca
Published: April 2020

The urine from 35 giraffes was studied by untargeted 1H-NMR, with the purpose of obtaining, for the first time, a fingerprint of its metabolome. The metabolome, as downstream of the transcriptome and proteome, has been considered as the most representative approach to monitor the relationships between animal physiological features and environment. Thirty-nine molecules were unambiguously quantified, able to give information about diet, proteins digestion, energy generation, and gut-microbial co-metabolism. The samples collected allowed study of the effects of age and sex on the giraffe urinary metabolome. In addition, preliminary information about how sampling procedure and pregnancy could affect a giraffe’s urinary metabolome was obtained. Such work could trigger the setting up of methods to non-invasively study the health status of giraffes, which is utterly needed, considering that anesthetic-related complications make their immobilization a very risky practice.
Drought Stress Responses in Context-Specific Genome-Scale Metabolic Models of Arabidopsis thaliana
Authors: Siriwach Ratklao , Matsuda Fumio , Yano Kentaro , Hirai Masami Yokota
Published: April 2020

Drought perturbs metabolism in plants and limits their growth. Because drought stress on crops affects their yields, understanding the complex adaptation mechanisms evolved by plants against drought will facilitate the development of drought-tolerant crops for agricultural use. In this study, we examined the metabolic pathways of Arabidopsis thaliana which respond to drought stress by omics-based in silico analyses. We proposed an analysis pipeline to understand metabolism under specific conditions based on a genome-scale metabolic model (GEM). Context-specific GEMs under drought and well-watered control conditions were reconstructed using transcriptome data and examined using metabolome data. The metabolic fluxes throughout the metabolic network were estimated by flux balance analysis using the context-specific GEMs. We used in silico methods to identify an important reaction contributing to biomass production and clarified metabolic reaction responses under drought stress by comparative analysis between drought and control conditions. This proposed pipeline can be applied in other studies to understand metabolic changes under specific conditions using Arabidopsis GEM or other available plant GEMs.
An Investigation on a Novel 3-RCU Flexible Micromanipulator
Authors: Qian Junnan , Li Yangmin , Zhuge Lukai
Published: April 2020

A novel type of spatial three revolute-cylindrical-universal (3-RCU) flexible micro manipulator is designed based on flexible hinges, and analyzed by finite element analysis (FEA). The piezoelectric actuators are adopted as driving devices in this platform, a new lever amplification mechanism is designed as its micro-displacement amplification mechanism, the workspace of the platform is enlarged, and the theoretical and simulation amplification ratios of the amplification mechanism are 3.056 and 2.985, respectively. The margin of error is just 2.3%. In space, the 3-RCU platform can realize the micro movement of three degrees of freedom. Also, the platform has a high carrying capacity, less motion loss, and the transmission efficiency is higher when the platform works. The decoupling performance, stress under extreme conditions and natural frequency of the platform are simulated by ANSYS Workbench software. A series of simulation analyses show the feasibility and security of the platform. The platform has good decoupling and working performance. The simulation results show that the platform has high simulation stiffness and high positioning accuracy.
Investigation of Hydrogen Embrittlement Susceptibility and Fracture Toughness Drop after in situ Hydrogen Cathodic Charging for an X65 Pipeline Steel
Authors: Kyriakopoulou Helen , Karmiris-Obratański Panagiotis , Tazedakis Athanasios , Daniolos Nikoalos , Dourdounis Efthymios , Manolakos Dimitrios , Pantelis Dimitrios
Published: April 2020

The present research focuses on the investigation of an in situ hydrogen charging effect during Crack Tip Opening Displacement testing (CTOD) on the fracture toughness properties of X65 pipeline steel. This grade of steel belongs to the broader category of High Strength Low Alloy Steels (HSLA), and its microstructure consists of equiaxed ferritic and bainitic grains with a low volume fraction of degenerated pearlite islands. The studied X65 steel specimens were extracted from pipes with 19.15 mm wall thickness. The fracture toughness parameters were determined after imposing the fatigue pre-cracked specimens on air, on a specific electrolytic cell under a slow strain rate bending loading (according to ASTM G147-98, BS7448, and ISO12135 standards). Concerning the results of this study, in the first phase the hydrogen cations’ penetration depth, the diffusion coefficient of molecular and atomic hydrogen, and the surficial density of blisters were determined. Next, the characteristic parameters related to fracture toughness (such as J, KQ, CTODel, CTODpl) were calculated by the aid of the Force-Crack Mouth Open Displacement curves and the relevant analytical equations.
Simulation Study of Surface Transfer Doping of Hydrogenated Diamond by MoO3 and V2O5 Metal Oxides
Authors: McGhee Joseph , Georgiev Vihar P.
Published: April 2020

In this work, we investigate the surface transfer doping process that is induced between hydrogen-terminated (100) diamond and the metal oxides, MoO3 and V2O5, through simulation using a semi-empirical Density Functional Theory (DFT) method. DFT was used to calculate the band structure and charge transfer process between these oxide materials and hydrogen terminated diamond. Analysis of the band structures, density of states, Mulliken charges, adsorption energies and position of the Valence Band Minima (VBM) and Conduction Band Minima (CBM) energy levels shows that both oxides act as electron acceptors and inject holes into the diamond structure. Hence, those metal oxides can be described as p-type doping materials for the diamond. Additionally, our work suggests that by depositing appropriate metal oxides in an oxygen rich atmosphere or using metal oxides with high stochiometric ration between oxygen and metal atoms could lead to an increase of the charge transfer between the diamond and oxide, leading to enhanced surface transfer doping.
Thermodynamic and Experimental Study on Efficient Extraction of Valuable Metals from Polymetallic Nodules
Authors: Su Kun , Ma Xiaodong , Parianos John , Zhao Baojun
Published: April 2020

Polymetallic nodules are promising resources for the extraction of valuable metals such as copper, nickel, and cobalt, as well as manganese alloys. To achieve efficient extraction of useful metals from the emerging resource, high-temperature carbothermic reduction of nodules was investigated by optimizing the reductant addition, slag and alloy systems. Thermochemical software FactSage was used to predict the liquidus temperature of the slag system, which is not sensitive to FeO, CaO and Al2O3, but decreases significantly with decreasing MnO/SiO2 mass ratio. The experiments were designed to reduce the oxides of Cu, Co and Ni completely, and reduce FeOx partially depending on the amount of graphite addition while leaving the residual slag for further processing into ferromanganese and/or silicomanganese alloys. Co, Cu and Ni concentrations in the alloy decreased with increasing graphite addition. The optimal reduction condition was reached by adding 4 wt% graphite at the MnO/SiO2 mass ratio of 1.6 in slag. The most effective metal-slag separation was achieved at 1350 °C, which enables the smelting reduction to be carried out in various furnaces.
Microstructural and Geochronological Analyses of Mesozoic Ductile Shear Zones in the Western Gyeonggi Massif, Korea: Implications for an Orogenic Cycle in the East Asian Continental Margin
Authors: Park Jeong-Yeong , Park Seung-Ik , Choi Taejin
Published: April 2020

In response to orogenic cycles, the ductile shear zone records a complex crustal deformation history. In this study, we conducted a microstructural analysis of two NW–SE trending ductile shear zones (Deokjeok Shear Zone (DSZ) and Soya Shear Zone (SSZ)) in the Late Triassic post-collisional granites along the western Gyeonggi Massif in the Korean Peninsula. The DSZ, overlain by the Late Triassic to the Early Jurassic post-collisional basin fill (Deokjeok Formation), has asymmetric microstructures indicative of a top-down-to-the-northeast shear. Depending on the structural position, the SSZ, which structurally overlies the Deokjeok Formation, exhibits two contrasting styles of deformation. The lower portion of the SSZ preserves evidence of top-up-to-the-southwest shearing after top-down-to-the-northeast shearing; on the other hand, the upper portion only indicates a top-up movement. Given the primary deformation mechanisms of both quartz and feldspar, the deformation temperatures of DSZ and SSZ were estimated at ~300–350 °C and ~350–400 °C, respectively, indicative of the mid-crustal condition. New zircon U-Pb isotopic ages from mylonitic granite in the SSZ and volcanic rocks in the Deokjeok Formation, combined with previously published geochronological data, indicate that the post-collisional granites and volcano-sedimentary sequence were nearly contemporaneous (ca. 223–217 Ma) and juxtaposed because of the Late Triassic orogenic collapse and subsequent new orogenic event. In this study, we highlight the role of the extensional DSZ as a detachment propagated into the middle crust during the Late Triassic orogenic collapse. Our results report a deformational response to a transition from the collisional Songrim Orogeny to the subduction-related Daebo Orogeny in the western Gyeonggi Massif. This, in turn, provides essential insight into cyclic mountain building/collapse in the East Asian continental margin during the Mesozoic time.
Sedative and Anxiolytic Activities of Opuntia ficus indica (L.) Mill.: An Experimental Assessment in Mice
Authors: Akkol Esra Küpeli , Ilhan Mert , Karpuz Büşra , Genç Yasin , Sobarzo-Sánchez Eduardo
Published: April 2020

Ethnobotanical field surveys revealed the use of fruits of Opuntia ficus indica (L.) Mill. for treating diabetes, burns, bronchial asthma, constipation, kidney stones, and rheumatic pains and as a sedative in Turkish folk medicine. This study aimed to verify the efficacy of the fruits of O. ficus indica experimentally and to define components responsible for the activity using bioassay-guided procedures. The crude methanolic extract of the fruits was sequentially fractionated into five subextracts: n-hexane, dichloromethane, ethyl acetate, n-butanol, and water. Further experiments were carried out on the most active subextract, that is, the ethyl acetate (EtOAc) subextract, which was further subjected to fractionation through successive column chromatographic applications on Sephadex LH-20. For activity assessment, each extract or fraction was submitted to bioassay systems; traction test, fireplace test, hole-board test, elevated plus-maze test, and open-field test were used for sedative and anxiolytic effects, and a thiopental-induced sleeping test was used for the hypnotic effect. Among the subextracts obtained from the methanolic extract, the EtOAc subextract showed significant sedative and anxiolytic effects in the bioassay systems. From the EtOAc subextract, major components were isolated, and their structures were determined as isorhamnetin, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-rutinoside, and kaempferol 3-O-rutinoside using spectral techniques. In conclusion, this study confirmed the claimed use of the plant against anxiety in Turkish folk medicine.
Synthesis and Molecular Modelling Studies of New 1,3-Diaryl-5-Oxo-Proline Derivatives as Endothelin Receptor Ligands
Authors: Intagliata Sebastiano , Helal Mohamed A. , Materia Luisa , Pittalà Valeria , Salerno Loredana , Marrazzo Agostino , Cagnotto Alfredo , Salmona Mario , Modica Maria N. , Romeo Giuseppe
Published: April 2020

The synthesis of seventeen new 1,3-diaryl-5-oxo-proline derivatives as endothelin receptor (ETR) ligands is described. The structural configuration of the new molecules was determined by analyzing selected signals in proton NMR spectra. In vitro binding assays of the human ETA and ETB receptors allowed us to identify compound 31h as a selective ETAR ligand. The molecular docking of the selected compounds and the ETA antagonist atrasentan in the ETAR homology model provided insight into the structural elements required for the affinity and the selectivity of the ETAR subtype.
Mannoside-Modified Branched Gold Nanoparticles for Photothermal Therapy to MDA-MB-231 Cells
Authors: Lin Han-Chen , Hsu Keng-Fang , Lai Chiao-Ling , Wu Tzu-Chien , Chen Hui-Fen , Lai Chian-Hui
Published: April 2020

Recently, gold nanoparticles (Au NPs) have been used to study the treatment of malignant tumors due to their higher biocompatibility and lesser toxicity. In addition, they can be excited through a specific wavelength to produce oscillating plasmonic photothermal therapy (PPTT) on the basis of the localized surface plasma resonance (LSPR) effect. Au NPs can be heated to kill cancer cells in specific parts of the body in a noninvasive manner. In this study, branched gold nanoparticles (BAu NPs) were prepared by mixing HAuCl4 in a 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer solution in a molar ratio of 1:2000. The UV–vis absorption peak was detected in the range of 700–1000 nm. Subsequently, BAu NPs were chemically linked to a thiol-modified mannoside molecule via a stable sulfur–Au covalent bond (Man@BAu NPs). Due to the presence of abundant mannose receptors on human-breast-cancer cells, MDA-MB-231, Man@BAu NPs were found to be abundant inside cancer cells. After irradiating the Man@BAu NP-laden MDA-MB231 switch with a near-infrared (NIR) laser at 808 nm wavelength, the photothermal-conversion effect raised the surface temperature of Man@BAu NPs, thus inducing cell death. Our experiment results demonstrated the advantages of applying Man@BAu NPs in inducing cell death in MDA-MB-231.
High-Efficient Production of (S)-1-[3,5-Bis(trifluoromethyl)phenyl]ethanol via Whole-Cell Catalyst in Deep-Eutectic Solvent-Containing Micro-Aerobic Medium System
Authors: Zhu Zhiren , Bi Shunde , Ye Ning , Wang Pu
Published: April 2020

The ratio of substrate to catalyst (S/C) is a prime target for the application of asymmetric production of enantiomerically enriched intermediates by whole-cell biocatalyst. In the present study, an attractive increase in S/C was achieved in a natural deep-eutectic solvent (NADES) containing reaction system under microaerobic condition for high production of (S)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol ((S)-3,5-BTPE) with Candida tropicalis 104. In PBS buffer (0.2 M, pH 8.0) at 200 rpm and 30 °C, 79.5 g (Dry Cell Weight, DCW)/L C. tropicalis 104 maintained the same yield of 73.7% for the bioreduction of 3,5-bis(trifluoromethyl)acetophenone (BTAP) under an oxygen-deficient environment compared with oxygen-sufficient conditions, while substrate load increased 4.0-fold (from 50 mM to 200 mM). Furthermore, when choline chloride:trehalose (ChCl:T, 1:1 molar ratio) was introduced into the reaction system for its versatility of increasing cell membrane permeability and declining BTAP cytotoxicity to biocatalyst, the yields were further increased to 86.2% under 200 mM BTAP, or 72.9% at 300 mM BTAP. After the optimization of various reaction parameters involved in the bioreduction, and the amount of biocatalyst and maltose co-substrate remained 79.5 g (DCW)/L and 50 g/L, the S/C for the reduction elevated 6.3 times (3.8 mM/g versus 0.6 mM/g). By altering the respiratory pattern of the whole-cell biocatalyst and exploiting the ChCl:T-containing reaction system, the developed strategy exhibits an attractive potential for enhancing catalytic efficiency of whole-cell-mediated reduction, and provides valuable insight for the development of whole-cell catalysis.
The Large-Scale Preparation and Optical Properties of MoS2/WS2 Vertical Hetero-Junction
Authors: Han Tao , Liu Hongxia , Wang Shulong , Chen Shupeng , Yang Kun
Published: April 2020

A variety of hetero-junctions can be constructed to form the basic structural units in the different optoelectronic devices, such as the photo-detectors, solar cells, sensors and light-emitting diodes. In our research, the large-area high-quality MoS2/WS2 vertical hetero-junction are prepared by the two-step atmospheric pressure chemical vapor deposition (APCVD) methods and the dry transfer method, and the corresponding optimal reaction conditions of MoS2/WS2 vertical hetero-junction are obtained. The morphology, composition and optical properties of MoS2/WS2 vertical hetero-junction are systematically characterized by the optical microscopy, Raman spectroscopy, photoluminescence spectroscopy, atomic force microscopy and the field emission scanning electron microscopy. Compared to the mechanical transfer method, the MoS2/WS2 vertical hetero-junction sample obtained by the APCVD and dry transfer methods have lower impurity content, cleaner interfaces and tighter interlayer coupling. Besides, the strong interlayer coupling and effective interlayer charge transfer of MoS2/WS2 vertical hetero-junction are also further studied. The photoluminescence intensity of MoS2/WS2 vertical hetero-junction is significantly reduced compared to the single MoS2 or WS2 material. In general, this research can help to achieve the large-scale preparation of various Van der Waals hetero-junctions, which can lay the foundation for the new application of optoelectronic devices.
Tuning of the Amount of Se in Rice (Oryza sativa) Grain by Varying the Nature of the Irrigation Method: Development of an ICP-MS Analytical Protocol, Validation and Application to 26 Different Rice Genotypes
Authors: Spanu Antonino , Langasco Ilaria , Valente Massimiliano , Deroma Mario Antonello , Spano Nadia , Barracu Francesco , Pilo Maria Itria , Sanna Gavino
Published: April 2020

The amount of specific trace elements like selenium (Se) may be of health concern for humans if contained in too high (or low) quantities in staple foods like rice. Among the attempts aimed to optimize the Se concentration in rice, only few studies have been focused on the use of irrigation methods other than continuous flooding. Since intermittent irriguous methods, like sprinkler and saturation, have found to be effective in modifying the bioaccumulation of arsenic and cadmium in rice kernels, the main goal of this study is to measure the amount of the total Se contained in grains of 26 rice genotypes cultivated for two consecutive agrarian vintages in the same open field and with the same water, but differently irrigated with continuous flooding, sprinkler or saturation. To do this, an original and validated ICP-MS method has been developed. The validation parameters accounted for a high sensitivity and accuracy. Sprinkler irrigation is able to reduce in the average of 90% the amount of total Se in kernels in comparison to values measured in rice irrigated with continuous flooding. In conclusion, different irrigation techniques and rice genotypes seem to be valuable tools in order to allow in the future the customized modulation of the Se concentration in rice grain according to the needs of the various populations.
Simultaneous Measurement of Urinary Trimethylamine (TMA) and Trimethylamine N-Oxide (TMAO) by Liquid Chromatography–Mass Spectrometry
Authors: Jia Xun , Osborn Lucas J. , Wang Zeneng
Published: April 2020

Trimethylamine (TMA) is a gut microbial metabolite—rendered by the enzymatic cleavage of nutrients containing a TMA moiety in their chemical structure. TMA can be oxidized as trimethylamine N-oxide (TMAO) catalyzed by hepatic flavin monooxygenases. Circulating TMAO has been demonstrated to portend a pro-inflammatory state, contributing to chronic diseases such as cardiovascular disease and chronic kidney disease. Consequently, TMAO serves as an excellent candidate biomarker for a variety of chronic inflammatory disorders. The highly positive correlation between plasma TMAO and urine TMAO suggests that urine TMAO has the potential to serve as a less invasive biomarker for chronic disease compared to plasma TMAO. In this study, we validated a method to simultaneously measure urine TMA and TMAO concentrations by liquid chromatography–mass spectrometry (LC/MS). Urine TMA and TMAO can be extracted by hexane/butanol under alkaline pH and transferred to the aqueous phase following acidification for LC/MS quantitation. Importantly, during sample processing, none of the nutrients with a chemical structure containing a TMA moiety were spontaneously cleaved to yield TMA. Moreover, we demonstrated that the acidification of urine prevents an increase of TMA after prolonged storage as was observed in non-acidified urine. Finally, here we demonstrated that TMAO can spontaneously degrade to TMA at a very slow rate.
The Oxidation-Induced Autofluorescence Hypothesis: Red Edge Excitation and Implications for Metabolic Imaging
Authors: Semenov Alexey N. , Yakimov Boris P. , Rubekina Anna A. , Gorin Dmitry A. , Drachev Vladimir P. , Zarubin Mikhail P. , Velikanov Alexander N. , Lademann Juergen , Fadeev Victor V. , Priezzhev Alexander V. , Darvin Maxim E. , Shirshin Evgeny A.
Published: April 2020

Endogenous autofluorescence of biological tissues is an important source of information for biomedical diagnostics. Despite the molecular complexity of biological tissues, the list of commonly known fluorophores is strictly limited. Still, the question of molecular sources of the red and near-infrared excited autofluorescence remains open. In this work we demonstrated that the oxidation products of organic components (lipids, proteins, amino acids, etc.) can serve as the molecular source of such red and near-infrared excited autofluorescence. Using model solutions and cell systems (human keratinocytes) under oxidative stress induced by UV irradiation we demonstrated that oxidation products can contribute significantly to the autofluorescence signal of biological systems in the entire visible range of the spectrum, even at the emission and excitation wavelengths higher than 650 nm. The obtained results suggest the principal possibility to explain the red fluorescence excitation in a large class of biosystems—aggregates of proteins and peptides, cells and tissues—by the impact of oxidation products, since oxidation products are inevitably presented in the tissue. The observed fluorescence signal with broad excitation originated from oxidation products may also lead to the alteration of metabolic imaging results and has to be taken into account.
Use of Fluorescence In Situ Hybridization (FISH) in Diagnosis and Tailored Therapies in Solid Tumors
Authors: Chrzanowska Natalia Magdalena , Kowalewski Janusz , Lewandowska Marzena Anna
Published: April 2020

Fluorescence in situ hybridization (FISH) is a standard technique used in routine diagnostics of genetic aberrations. Thanks to simple FISH procedure is possible to recognize tumor-specific abnormality. Its applications are limited to designed probe type. Gene rearrangements e.g., ALK, ROS1 reflecting numerous translocational partners, deletions of critical regions e.g., 1p and 19q, gene fusions e.g., COL1A1-PDGFB, genomic imbalances e.g., 6p, 6q, 11q and amplifications e.g., HER2 are targets in personalized oncology. Confirmation of genetic marker is frequently a direct indication to start specific, targeted treatment. In other cases, detected aberration helps pathologists to better distinguish soft tissue sarcomas, or to state a final diagnosis. Our main goal is to show that applying FISH to formalin-fixed paraffin-embedded tissue sample (FFPE) enables assessing genomic status in the population of cells deriving from a primary tumor or metastasis. Although many more sophisticated techniques are available, like Real-Time PCR or new generation sequencing, FISH remains a commonly used method in many genetic laboratories.
First Example of Catalytic Synthesis of Cyclic S-Containing Di- and Triperoxides
Authors: Makhmudiyarova Nataliya , Ishmukhametova Irina , Dzhemileva Lilya , D’yakonov Vladimir , Ibragimov Askhat , Dzhemilev Usein
Published: April 2020

An efficient method for the synthesis of tetraoxathiaspiroalkanes, tetraoxathiocanes, and hexaoxathiadispiroalkanes was developed by reactions of pentaoxacanes, pentaoxaspiroalkanes, and heptaoxadispiroalkanes with hydrogen sulfide in the presence of a catalyst, Sm(NO3)3·6H2O. We found that the synthesized S-containing di- and triperoxides exhibit high cytotoxic activity against Jurkat, K562, U937, and HL60 tumor cultures, and fibroblasts.
Stereoisomers of Colourless Carotenoids from the Marine Microalga Dunaliella salina
Authors: Mazzucchi Laura , Xu Yanan , Harvey Patricia
Published: April 2020

Carotenoids comprise a diverse range of naturally occurring stereoisomers, which differ in their physico-chemical properties. Their biosynthesis begins with phytoene, which is a rarity among carotenoids because it is colourless. Phytoene is sought after as a skin protectant against harmful UV range B (290–320 nm) and C (100–290 nm) light, and as a natural skin-whitening agent and is synthesized from geranylgeranyl diphosphate. Geranylgeranyl diphosphate is catalysed by phytoene synthase and phytoene desaturase to phytoene and phytofluene, respectively. The subsequent steps involve desaturation, isomerisation and cyclisation reactions to form α- and β-carotene stereoisomers, via all-trans lycopene. The marine microalga Dunaliella salina is the richest source of β-carotene, but it can accumulate phytoene and phytofluene as well. In the present study, different analytical tools including High-Performance Liquid Chromatography (HPLC), Ultra-Performance Convergence Chromatography (UPC2-MS) and Nuclear Magnetic Resonance (NMR) were used to characterize and quantify the phytoene isomeric configurations in D. salina in order to explore both the feasibility of D. salina as a cell factory for phytoene production and to gain new insight into the carotenoid synthesis pathway in D. salina. D. salina, similar to tomato, produced predominantly 15-cis phytoene isomer (>98%) and a trace amount of all-trans phytoene (<2%). High light stress, red light stress, or use of a phytoene desaturase inhibitor or a mitotic disrupter herbicide led to the accumulation of 15-cis phytoene but not all-trans phytoene. 9-cis phytoene was not detected in any of the extracts of D. salina biomass. Our main findings suggest that 15-cis phytoene is the most abundant isomer in D. salina and that it is subject to a series of isomerisation and desaturation reactions to form all-trans and 9-cis β-carotene.