bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical Thinking Styles—The Advantage of Analytic Thinkers When Learning Mathematics
Authors: Huincahue Jaime , Borromeo-Ferri Rita , Reyes-Santander Pamela , Garrido-Véliz Viviana
Published: June 2021

School is a space where learning mathematics should be accompanied by the student’s preferences; however, its valuation in the classroom is not necessarily the same. From a quantitative approach, we ask from the mathematical thinking styles (MTS) theory about the correlations between preferences of certain MTS and mathematical performance. For this, a valid test instrument and a sample of 275 16-year-old Chilean students were used to gain insight into their preferences, beliefs and emotions when solving mathematical tasks and when learning mathematics. The results show, among other things, a clear positive correlation between mathematical performance and analytical thinking style, and also evidence the correlation between self-efficacy, analytical thinking and grades. It is concluded that students who prefer the analytical style are more advantageous in school, since the evaluation processes have a higher valuation of analytic mathematical thinking.
Making Sense of Complex Sensor Data Streams
Authors: Liu Rongrong , Dresp-Langley Birgitta
Published: June 2021

This concept paper draws from our previous research on individual grip force data collected from biosensors placed on specific anatomical locations in the dominant and non-dominant hand of operators performing a robot-assisted precision grip task for minimally invasive endoscopic surgery. The specificity of the robotic system on the one hand, and that of the 2D image-guided task performed in a real-world 3D space on the other, constrain the individual hand and finger movements during task performance in a unique way. Our previous work showed task-specific characteristics of operator expertise in terms of specific grip force profiles, which we were able to detect in thousands of highly variable individual data. This concept paper is focused on two complementary data analysis strategies that allow achieving such a goal. In contrast with other sensor data analysis strategies aimed at minimizing variance in the data, it is necessary to decipher the meaning of intra- and inter-individual variance in the sensor data on the basis of appropriate statistical analyses, as shown in the first part of this paper. Then, it is explained how the computation of individual spatio-temporal grip force profiles allows detecting expertise-specific differences between individual users. It is concluded that both analytic strategies are complementary and enable drawing meaning from thousands of biosensor data reflecting human performance measures while fully taking into account their considerable inter- and intra-individual variability.
Efficient Chaos-Based Substitution-Box and Its Application to Image Encryption
Authors: El-Latif Ahmed A. Abd , Abd-El-Atty Bassem , Belazi Akram , Iliyasu Abdullah M.
Published: June 2021

Chaotic systems are vital in designing contemporary cryptographic systems. This study proposes an innovative method for constructing an effective substitution box using a 3-dimensional chaotic map. Moreover, bouyed by the efficiency of the proposed chaos-based substitution boxes’ effectiveness, we introduce a new chaos-based image cryptosystem that combines the adeptness of Gray codes, a non-linear and sensitive hyper-chaotic system, and the proposed S-box. The generated secret key emanating from the cryptosystem is correlated to the input image to produce a unique key for each image. Extensive experimental outcomes demonstrate the utility, effectiveness, and high performance of the resulting cryptosystem.
Wind in a Natural and Artificial Wildland Fire Fuel Bed
Authors: Bebieva Yana , Speer Kevin , White Liam , Smith Robert , Mayans Gabrielle , Quaife Bryan
Published: June 2021

Fuel beds represent the layer of fuel that typically supports continuous combustion and wildland fire spread. We examine how wind propagates through and above loose and packed pine needle beds and artificial 3D-printed fuel beds in a wind tunnel. Vertical profiles of horizontal velocities are measured for three artificial fuel beds with prescribed porosities and two types of fuel beds made with long-leaf pine needles. The dependence of the mean velocity within the fuel bed with respect to the ambient velocity is linked to the porosity. Experimental results show significant structure to the vertical profile of mean flow within the bed, and suggest that small-scale sweeps and ejections play a role in this system redistributing momentum similar to larger-scale canopy flows.
Investigating the Relationship of Genotype and Climate Conditions on the Volatile Composition and Sensory Profile of Celery (Apium graveolens)
Authors: Turner Lucy , Lignou Stella , Gawthrop Frances , Wagstaff Carol
Published: June 2021

Apium graveolens is a biennial crop grown across the globe for its stalks, leaves and seed and is known for its distinct flavour and strong taste. Various extraction methods on fresh and dried celery and its essential oil are reported in the literature examining the aroma profile of this crop and demonstrating that its volatile composition is determined by variables including cultivar, season, geographical location and agronomic practices. This study investigated the volatile and sensory profile of eight celery genotypes grown over two years (2018 and 2020) in the same location in the UK. Solid-phase-micro-extraction followed by gas chromatography-mass spectrometry were used to determine the volatile compounds present in these genotypes and sensory evaluation using a trained panel to assess the sensory profile of fresh celery. Significant differences (p < 0.05) in the volatile composition and sensory profile were observed and influenced by both genotype and harvest year. Two genotypes exhibited similar aroma composition and sensory profile between the years. Celery samples harvested in 2018, which possessed air temperatures that were considerably warmer than in 2020, exhibited higher proportions of sesquiterpenes and phthalides and we hypothesise that the higher proportions were generated as a response to heat stress. Studying the relationship between the genotype and the environment will provide clear information to guide growers in how to consistently produce a higher quality crop.
Reading Food Experiences from the Face: Effects of Familiarity and Branding of Soy Sauce on Facial Expressions and Video-Based RPPG Heart Rate
Authors: de Wijk Rene A. , Ushiama Shota , Ummels Meeke , Zimmerman Patrick , Kaneko Daisuke , Vingerhoeds Monique H.
Published: June 2021

Food experiences are not only driven by the food’s intrinsic properties, such as its taste, texture, and aroma, but also by extrinsic properties such as visual brand information and the consumers’ previous experiences with the foods. Recent developments in automated facial expression analysis and heart rate detection based on skin color changes (remote photoplethysmography or RPPG) allow for the monitoring of food experiences based on video images of the face. RPPG offers the possibility of large-scale non-laboratory and web-based testing of food products. In this study, results from the video-based analysis were compared to the more conventional tests (scores of valence and arousal using Emojis and photoplethysmography heart rate (PPG)). Forty participants with varying degrees of familiarity with soy sauce were presented with samples of rice and three commercial soy sauces with and without brand information. The results showed that (1) liking and arousal were affected primarily by the specific tastes, but not by branding and familiarity. In contrast, facial expressions were affected by branding and familiarity, and to a lesser degree by specific tastes. (2) RPPG heart rate and PPG both showed effects of branding and familiarity. However, RPPG heart rate needs further development because it underestimated the heart rate compared to PPG and was less sensitive to changes over time and with activity (viewing of brand information and tasting). In conclusion, this study suggests that recording of facial expressions and heart rates may no longer be limited to laboratories but can be done remotely using video images, which offers opportunities for large-scale testing in consumer science.
Pre-Operational Application of a WRF-Hydro-Based Fluvial Flood Forecasting System in the Southeast Mediterranean
Authors: Giannaros Christos , Galanaki Elissavet , Kotroni Vassiliki , Lagouvardos Konstantinos , Oikonomou Christina , Haralambous Haris , Giannaros Theodore M.
Published: June 2021

The Southeast Mediterranean (SEM) is characterized by increased vulnerability to river/stream flooding. However, impact-oriented, operational fluvial flood forecasting is far away from maturity in the region. The current paper presents the first attempt at introducing an operational impact-based warning system in the area, which is founded on the coupling of a state-of-the-art numerical weather prediction model with an advanced spatially-explicit hydrological model. The system’s modeling methodology and forecasting scheme are presented, as well as prototype results, which were derived under a pre-operational mode. Future developments and challenges needed to be addressed in terms of validating the system and increasing its efficiency are also discussed. This communication highlights that standard approaches used in operational weather forecasting in the SEM for providing flood-related information and alerts can, and should, be replaced by advanced coupled hydrometeorological systems, which can be implemented without a significant cost on the operational character of the provided services. This is of great importance in establishing effective early warning services for fluvial flooding in the region.
Proposed Framework for Comparison of Continuous Probabilistic Genotyping Systems amongst Different Laboratories
Authors: McNevin Dennis , Wright Kirsty , Barash Mark , Gomes Sara , Jamieson Allan , Chaseling Janet
Published: June 2021

Continuous probabilistic genotyping (PG) systems are becoming the default method for calculating likelihood ratios (LRs) for competing propositions about DNA mixtures. Calculation of the LR relies on numerical methods and simultaneous probabilistic simulations of multiple variables rather than on analytical solutions alone. Some also require modelling of individual laboratory processes that give rise to electropherogram artefacts and peak height variance. For these reasons, it has been argued that any LR produced by continuous PG is unique and cannot be compared with another. We challenge this assumption and demonstrate that there are a set of conditions defining specific DNA mixtures which can produce an aspirational LR and thereby provide a measure of reproducibility for DNA profiling systems incorporating PG. Such DNA mixtures could serve as the basis for inter-laboratory comparisons, even when different STR amplification kits are employed. We propose a procedure for an inter-laboratory comparison consistent with these conditions.
Gender Differences in Kinematic Analysis of the Lower Limbs during the Chasse Step in Table Tennis Athletes
Authors: Yang Xiaoyi , He Yuqi , Shao Shirui , Baker Julien S. , István Bíró , Gu Yaodong
Published: June 2021

The chasse step is one of the most important footwork maneuvers used in table tennis. The purpose of this study was to investigate the lower limb kinematic differences of table tennis athletes of different genders when using the chasse step. The 3D VICON motion analysis system was used to capture related kinematics data. The main finding of this study was that the step times for male athletes (MA) were shorter in the backward phase (BP) and significantly longer in the forward phase (FP) than for female athletes (FA) during the chasse step. Compared with FA, knee external rotation for MA was larger during the BP. MA showed a smaller knee flexion range of motion (ROM) in the BP and larger knee extension ROM in the FP. Moreover, hip flexion and adduction for MA were significantly greater than for FA. In the FP, the internal rotational velocity of the hip joint was significantly greater. MA showed larger hip internal rotation ROM in the FP but smaller hip external rotation ROM in the BP. The differences between genders can help coaches personalize their training programs and improve the performance of both male and female table tennis athletes.
Health-ID: A Blockchain-Based Decentralized Identity Management for Remote Healthcare
Authors: Javed Ibrahim Tariq , Alharbi Fares , Bellaj Badr , Margaria Tiziana , Crespi Noel , Qureshi Kashif Naseer
Published: June 2021

COVID-19 has made eHealth an imperative. The pandemic has been a true catalyst for remote eHealth solutions such as teleHealth. Telehealth facilitates care, diagnoses, and treatment remotely, making them more efficient, accessible, and economical. However, they have a centralized identity management system that restricts the interoperability of patient and healthcare provider identification. Thus, creating silos of users that are unable to authenticate themselves beyond their eHealth application’s domain. Furthermore, the consumers of remote eHealth applications are forced to trust their service providers completely. They cannot check whether their eHealth service providers adhere to the regulations to ensure the security and privacy of their identity information. Therefore, we present a blockchain-based decentralized identity management system that allows patients and healthcare providers to identify and authenticate themselves transparently and securely across different eHealth domains. Patients and healthcare providers are uniquely identified by their health identifiers (healthIDs). The identity attributes are attested by a healthcare regulator, indexed on the blockchain, and stored by the identity owner. We implemented smart contracts on an Ethereum consortium blockchain to facilities identification and authentication procedures. We further analyze the performance using different metrics, including transaction gas cost, transaction per second, number of blocks lost, and block propagation time. Parameters including block-time, gas-limit, and sealers are adjusted to achieve the optimal performance of our consortium blockchain.
A Study of Leisure Constraints and Job Satisfaction of Middle-Aged and Elderly Health Care Workers in COVID-19 Environment
Authors: Wu Chien-Hung , Lin Hsiao-Hsien , Lai Sin-Yu , Tseng Kuan-Chieh , Hsu Chin-Hsien
Published: June 2021

The purpose of the study was to examine the leisure constraints and job satisfaction of middle-aged and elderly health care workers. The study employed a mixed research method, utilizing SPSS 22.0 and AMOS 23.0 statistical software to analyze 260 questionnaires using basic statistical tests, t-tests, ANOVA tests, and structural equation models, and then interviewed medical and public health workers and experts in the field, and the results were analyzed using multivariate verification analysis. The results showed that there was a significant low correlation between leisure constraints and job satisfaction among middle-aged and elderly health care workers (p < 0.01); interpersonal constraints and external job satisfaction factors were the main influencing factors; improving promotion opportunities and receiving appreciation increased job satisfaction; poor working environment and facilities, as well as the lack of achievement, were the main factors that reduced satisfaction; health factors, a lack of family support, no exercise partner, and a lack of extra budget are the key to leisure constraints. If the organization can provide nearby sports facilities for middle and high-age medical workers, improve welfare, and increase willingness to participate in leisure activities, physical and mental health can be improved. Finally, interpersonal interaction in leisure obstacles is the main reason for improving job satisfaction.
Healthcare and Economic Impact of Lung Perfusion Scintigraphy in Patients Affected by Acute Pulmonary Embolism
Authors: Rubini Giuseppe , Ferrari Cristina , Mammucci Paolo , Pisani Antonio Rosario , Mincarone Pierpaolo , Leo Carlo Giacomo
Published: June 2021

Acute pulmonary embolism (APE) is a cardiovascular emergency, representing the main cause of mortality, morbidity, and hospitalisation in Europe. We aim to evaluate the economic and healthcare impact of lung perfusion scintigraphy (LPS) used in patients with suspected APE, in the event of non-conclusive or contraindicated computed tomography pulmonary angiography (CTPA). We considered two alternative healthcare processes for APE diagnosis, with and without LPS. We performed a cost analysis with the aim of evaluating the average direct healthcare costs for diagnosis, risk assessment, and treatment of APE. We used data from a monocentric trial. Our economic model showed that the strategy with LPS was preferable in terms of costs. The average per-patient costs for the diagnosis and treatment of the acute phase of PE in low-risk patients with a non-conclusive or not-executable CTPA, with and without LPS, are EUR 2145.25 and EUR 4912.45, respectively. LPS is a simple, quick, and economic examination, useful in this setting of patients not only for an early diagnosis but also to exclude APE, demonstrating an advantage in terms of healthcare resources. To the best of our knowledge, this study is the first to analyse the economic and healthcare impact of the use of LPS in the diagnostic pathway of suspected APE.
Characterization of Female External Genitalia and Eggs of Four South American Species of the Triatoma Laporte, 1832 Genus (Hemiptera: Reduviidae: Triatominae)
Authors: Belintani Tiago , Oliveira Jader , Pinotti Heloisa , Alevi Kaio Cesar Chaboli , Nascimento Juliana Damieli , Sasso-Cerri Estela , Galvão Cleber , Aristeu da Rosa João
Published: June 2021

Triatoma is the most diversified and one of the most important genera from an epidemiological perspective. Given the difficulty in identifying some species of the Triatoma genus, morphological, histological, and morphometric studies were performed to provide new characters that make it possible to differentiate T. garciabesi, T. guasayana, T. patagonica, and T. sordida sensu stricto, triatomines that overlap geographically and have vector potential. Through the external female genitalia, as well as morphology, morphometry, and histology of eggshells, it was possible to discriminate the four species. In addition, this study reinforces the taxonomic validity of T. garciabesi and provides new data for discussion on systematic issues of T. guasayana and T. patagonica.
Formal Assignation of the Kissing Bug Triatoma lecticularia (Hemiptera: Reduviidae: Triatominae) to the Genus Paratriatoma
Authors: de Paiva Vinicius Fernandes , Oliveira Jader de , Galvão Cleber , Justi Silvia Andrade , Landa José Manuel Ayala , Rosa João Aristeu da
Published: June 2021

The subfamily Triatominae (Hemiptera: Reduviidae) comprises hematophagous insects that are vectors of Chagas disease; including species assigned to the genera Triatoma and Paratriatoma. Initial examination of Triatoma lecticularia revealed the hirsuteness covering the entire body—a characteristic and striking feature of members of the genus Paratriatoma—and a systematic study revealed several other morphological characters that are in diagnostic alignment with Paratriatoma. Based on the examination of several specimens (including the lectotype), and with the additional support of molecular and cytogenetic data, we propose the formal transferal of Triatoma lecticularia (Stål, 1859) into the genus Paratriatoma with the resulting new combination: Paratriatoma lecticularia (Stål, 1859) comb. nov. (Hemiptera: Reduviidae: Triatominae).
Differences in Life History Traits in Rural vs. Urban Populations of a Specialist Ground Beetle, Carabus convexus
Authors: Magura Tibor , Mizser Szabolcs , Horváth Roland , Nagy Dávid D. , Tóth Mária , Csicsek Réka , Lövei Gábor L.
Published: June 2021

Urbanization is increasing worldwide and causes substantial changes in environmental parameters, generating various kinds of stress on arthropods, with several harmful consequences. We examined a forest specialist ground beetle, Carabus convexus, in forested habitats to evaluate the changes in four important life history traits between rural and urban populations. Analyzing beetles from the overwintered cohort in their first breeding season, we found no significant differences in body length or body mass between the rural and urban individuals. Body condition, judged by fat reserve scores, was similarly poor in both habitats, indicating that beetles were not able to accumulate substantial fat reserves at either habitat. Females with ripe eggs in their ovaries were first captured at the same time in both areas. The number of ripe eggs, however, was significantly higher in females of the low-density urban population (6.13 eggs/female) than in those of the high-density rural population (4.14 eggs/female), indicating density-dependent fecundity. Altered environmental and habitat conditions by urbanization, however, seemed to cause high mortality during egg hatching and/or larval development, preventing the growth of the urban population to the level of rural one.
Noninvasive Assessment of Hepatitis C Virus Infected Patients Using Vibration-Controlled Transient Elastography
Authors: Florea Mira , Serban Teodora , Tirpe George Razvan , Tirpe Alexandru , Lupsor-Platon Monica
Published: June 2021

Chronic infection with hepatitis C virus (HCV) is one of the leading causes of cirrhosis and hepatocellular carcinoma (HCC). Surveillance of these patients is an essential strategy in the prevention chain, including in the pre/post-antiviral treatment states. Ultrasound elastography techniques are emerging as key methods in the assessment of liver diseases, with a number of advantages such as their rapid, noninvasive, and cost-effective characters. The present paper critically reviews the performance of vibration-controlled transient elastography (VCTE) in the assessment of HCV patients. VCTE measures liver stiffness (LS) and the ultrasonic attenuation through the embedded controlled attenuation parameter (CAP), providing the clinician with a tool for assessing fibrosis, cirrhosis, and steatosis in a noninvasive manner. Moreover, standardized LS values enable proper staging of the underlying fibrosis, leading to an accurate identification of a subset of HCV patients that present a high risk for complications. In addition, VCTE is a valuable technique in evaluating liver fibrosis prior to HCV therapy. However, its applicability in monitoring fibrosis regression after HCV eradication is currently limited and further studies should focus on extending the boundaries of VCTE in this context. From a different perspective, VCTE may be effective in identifying clinically significant portal hypertension (CSPH). An emerging prospect of clinical significance that warrants further study is the identification of esophageal varices. Our opinion is that the advantages of VCTE currently outweigh those of other surveillance methods.
Development and Mechanical Characterisation of Al6061-Al2O3-Graphene Hybrid Metal Matrix Composites
Authors: Boppana Satish Babu , Dayanand Samuel , Murthy Bharath Vedashantha , Nagaral Madeva , Telagu Aravinda , Kumar Vijee , Auradi Virupaxi
Published: June 2021

MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al2O3 (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al2O3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al2O3 reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al2O3 particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al2O3 particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al2O3p composites is presented by following ASTM guidelines; results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.
Optimizing the Formation of Hydraulic Cylinder Surfaces, Taking into Account Their Microrelief Topography Analyzed during Different Operations
Authors: Dzyura Volodymyr , Maruschak Pavlo
Published: June 2021

Causes of the in-service damage to hydrocylinder liners were investigated, and the requirements to their working surfaces were systematized. Roughness parameter Ra was found not to provide a precise estimate of the surface quality because its reduction did not affect surface microgeometry. Additionally, the surface quality was assessed by the Abbott-Firestone curve during the finishing operation. The optimized manufacturing technology for obtaining hydrocylinder liners was offered based on having the required microgeometry and surface quality provided by cutting operations. The quality and service characteristics of internal surfaces of hydrocylinder liners were improved by changing technological operations. In particular, the semi-finish turning was chosen to provide for the surface roughness parameter Ra within 6.3–8.0 μm and the roughness pitch parameter S within 0.4–0.6 mm and homogeneous surface structure. The finishing rolling was replaced by burnishing to form a regular microrelief.
Runge–Kutta Pairs of Orders 6(5) with Coefficients Trained to Perform Best on Classical Orbits
Authors: Shen Yu-Cheng , Lin Chia-Liang , Simos Theodore E. , Tsitouras Charalampos
Published: June 2021

We consider a family of explicit Runge–Kutta pairs of orders six and five without any additional property (reduced truncation errors, Hamiltonian preservation, symplecticness, etc.). This family offers five parameters that someone chooses freely. Then, we train them in order for the presented method to furnish the best results on a couple of Kepler orbits, a certain interval and tolerance. Consequently, we observe an efficient performance on a wide range of orbital problems (i.e., Kepler for a variety of eccentricities, perturbed Kepler with various disturbances, Arenstorf and Pleiades). About 1.8 digits of accuracy is gained on average over conventional pairs, which is truly remarkable for methods coming from the same family and order.
Severe Coronary Artery Disease in a Person Living with HIV
Authors: Bajdechi Mircea , Mihai Cosmin , Scafa-Udriste Alexandru , Cherry Ali , Zamfir Diana , Dumitru Irina , Cernat Roxana , Rugina Sorin
Published: June 2021

The pathophysiology of accelerated atherosclerosis in people living with Human Immunofediciency virus (HIV) is complex. Coronary artery disease (CAD) has become an important cause of mortality in these patients. They often have atypical symptoms, leading to frequently missed diagnoses. We report a case of a 51-year-old male undergoing antiretroviral therapy who was admitted for acute coronary syndrome. He had severe coronary artery disease that involved difficult management.
COVID-19 Pandemic in Rio de Janeiro, Brazil: A Social Inequality Report
Authors: Bernardo Yago , do Rosario Denes , Conte-Junior Carlos
Published: June 2021

Background and Objectives: To perform a retrospective report on the lethality of COVID-19 in different realities in the city of Rio de Janeiro (RJ). Materials and Methods: We accomplished an observational study by collecting the data about total confirmed cases and deaths due to COVID-19 in the top 10 high social developed neighborhoods and top 10 most populous favelas in RJ to determine the case-fatality rate (CFR) and compare these two different realities. Results: CFR was significatively higher in poverty areas of RJ, reaching a mean of 9.08% in the most populous favelas and a mean of 4.87% in the socially developed neighborhoods. Conclusions: The social mitigation measures adopted in RJ have benefited only smaller portions of the population, excluding needy communities.
Predominant Polarity and Polarity Index of Maintenance Treatments for Bipolar Disorder: A Validation Study in a Large Naturalistic Sample in Italy
Authors: Albert Umberto , Manchia Mirko , Burato Sofia , Carpiniello Bernardo , Di Salvo Gabriele , Pinna Federica , Rosso Gianluca , Maina Giuseppe
Published: June 2021

Background and Objectives: Predominant polarity (PP) may be a useful course specifier in at least a significant proportion of patients with Bipolar Disorder (BD), being associated with several clinically relevant correlates. Emerging evidence suggests that the concept of PP might influence the selection of maintenance treatments, based on a drug polarity index (PI) which measures the greater antidepressive vs. antimanic preventive efficacy of mood stabilizers over long-term maintenance treatment. In this study, we aimed to validate the PI in a large sample of Italian BD patients with accurate longitudinal characterization of the clinical course, which ensured a robust definition of the PP. Materials and Methods: Our sample is comprised of 653 patients with BD, divided into groups based on the predominant polarity (manic/hypomanic predominant polarity—MPP, depressive predominant polarity—DPP and no predominant polarity). Subsequently we calculated the mean total polarity index for each group, and we compared the groups. Results: When we examined the mean PI of treatments prescribed to individuals with DPP, MPP and no predominant polarity, calculated using two different methods, we failed to find significant differences, with the exception of the PI calculated with the Popovic method and using the less stringent criterion for predominant polarity (PP50%). Conclusions: Future prospective studies are needed in order to determine whether the predominant polarity is indeed one clinical factor that might guide the clinician in choosing the right mood stabilizer for BD maintenance treatment.
Metabolomics Studies in Psoriatic Disease: A Review
Authors: Koussiouris John , Looby Nikita , Anderson Melanie , Kulasingam Vathany , Chandran Vinod
Published: June 2021

Metabolomics investigates a broad range of small molecules, allowing researchers to understand disease-related changes downstream of the genome and proteome in response to external environmental stimuli. It is an emerging technology that holds promise in identifying biomarkers and informing the practice of precision medicine. In this review, we summarize the studies that have examined endogenous metabolites in patients with psoriasis and/or psoriatic arthritis using nuclear magnetic resonance (NMR) or mass spectrometry (MS) and were published through 26 January 2021. A standardized protocol was used for extracting data from full-text articles identified by searching OVID Medline ALL, OVID Embase, OVID Cochrane Central Register of Controlled Trials and BIOSIS Citation Index in Web of Science. Thirty-two studies were identified, investigating various sample matrices and employing a wide variety of methods for each step of the metabolomics workflow. The vast majority of studies identified metabolites, mostly amino acids and lipids that may be associated with psoriasis diagnosis and activity. Further exploration is needed to identify and validate metabolomic biomarkers that can accurately and reliably predict which psoriasis patients will develop psoriatic arthritis, differentiate psoriatic arthritis patients from patients with other inflammatory arthritides and measure psoriatic arthritis activity.
Complete Genome Sequence and Function Gene Identify of Prometryne-Degrading Strain Pseudomonas sp. DY-1
Authors: Liang Dong , Xiao Changyixin , Song Fuping , Li Haitao , Liu Rongmei , Gao Jiguo
Published: June 2021

The genus Pseudomonas is widely recognized for its potential for environmental remediation and plant growth promotion. Pseudomonas sp. DY-1 was isolated from the agricultural soil contaminated five years by prometryne, it manifested an outstanding prometryne degradation efficiency and an untapped potential for plant resistance improvement. Thus, it is meaningful to comprehend the genetic background for strain DY-1. The whole genome sequence of this strain revealed a series of environment adaptive and plant beneficial genes which involved in environmental stress response, heavy metal or metalloid resistance, nitrate dissimilatory reduction, riboflavin synthesis, and iron acquisition. Detailed analyses presented the potential of strain DY-1 for degrading various organic compounds via a homogenized pathway or the protocatechuate and catechol branches of the β-ketoadipate pathway. In addition, heterologous expression, and high efficiency liquid chromatography (HPLC) confirmed that prometryne could be oxidized by a Baeyer-Villiger monooxygenase (BVMO) encoded by a gene in the chromosome of strain DY-1. The result of gene knock-out suggested that the sulfate starvation-induced (SSI) genes in this strain might also involve in the process of prometryne degradation. These results would provide the molecular basis for the application of strain DY-1 in various fields and would contribute to the study of prometryne biodegradation mechanism as well.
Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806
Authors: Guljamow Arthur , Barchewitz Tino , Große Rebecca , Timm Stefan , Hagemann Martin , Dittmann Elke
Published: June 2021

The ubiquitous freshwater cyanobacterium Microcystis is remarkably successful, showing a high tolerance against fluctuations in environmental conditions. It frequently forms dense blooms which can accumulate significant amounts of the hepatotoxin microcystin, which plays an extracellular role as an infochemical but also acts intracellularly by interacting with proteins of the carbon metabolism, notably with the CO2 fixing enzyme RubisCO. Here we demonstrate a direct link between external microcystin and its intracellular targets. Monitoring liquid cultures of Microcystis in a diel experiment revealed fluctuations in the extracellular microcystin content that correlate with an increase in the binding of microcystin to intracellular proteins. Concomitantly, reversible relocation of RubisCO from the cytoplasm to the cell’s periphery was observed. These variations in RubisCO localization were especially pronounced with cultures grown at higher cell densities. We replicated these effects by adding microcystin externally to cultures grown under continuous light. Thus, we propose that microcystin may be part of a fast response to conditions of high light and low carbon that contribute to the metabolic flexibility and the success of Microcystis in the field.
Borrelia burgdorferi Sensu Lato in Questing and Engorged Ticks from Different Habitat Types in Southern Germany
Authors: Răileanu Cristian , Silaghi Cornelia , Fingerle Volker , Margos Gabriele , Thiel Claudia , Pfister Kurt , Overzier Evelyn
Published: June 2021

Borrelia burgdorferi sensu lato (s.l.) causes the most common tick-borne infection in Europe, with Germany being amongst the countries with the highest incidences in humans. This study aimed at (1) comparing infection rates of B. burgdorferi s.l. in questing Ixodes ricinus ticks from different habitat types in Southern Germany, (2) analysing genospecies distribution by habitat type, and (3) testing tissue and ticks from hosts for B. burgdorferi s.l. Questing ticks from urban, pasture, and natural habitats together with feeding ticks from cattle (pasture) and ticks and tissue samples from wild boars and roe deer (natural site) were tested by PCR and RFLP for species differentiation. B. burgdorferi s.l. was found in 29.8% questing adults and 15% nymphs. Prevalence was lower at the urban sites with occurrence of roe deer than where these were absent. Borrelia burgdorferi s.l. DNA was found in 4.8% ticks from roe deer, 6.3% from wild boar, and 7.8% from cattle. Six genospecies were identified in unfed ticks: Borrelia afzelii (48.6%), Borrelia burgdorferi sensu stricto (16%), Borrelia garinii (13.2%), Borrelia valaisiana (7.5%), Borrelia spielmanii (6.2%), and Borrelia bavariensis (0.9%). This study shows high infection levels and a great diversity of Borrelia in questing ticks. The presence of roe deer seems to reduce B. burgdorferi s.l. infection rates in tick populations.
Modified Exfoliated Carbon Nanoplatelets as Sorbents for Ammonium from Natural Mineral Waters
Authors: Ion Ion , Bogdan Daniela , Mincu Monica Maria , Ion Alina Catrinel
Published: June 2021

In this manuscript an improved sorbent based on modified exfoliated carbon nanoplatelets, applied in the removal of ammonium from aqueous samples, is presented. This sorbent showed better efficiency in comparison with the previous one obtained in our group for ammonium removal, the values of the maximum sorption capacity being improved from 10 to 12.04 mg/g. In terms of kinetics and sorption characteristic parameters, their values were also improved. Based on these results, a sorption mechanism was proposed, taking into account ion-exchange and chemisorption processes at the surface of the oxidized exfoliated carbon nanoplatelets. Future applications for simultaneous removal of other positive charged contaminants from natural waters might be possible.
Pharmacokinetics-Driven Evaluation of the Antioxidant Activity of Curcuminoids and Their Major Reduced Metabolites—A Medicinal Chemistry Approach
Authors: Girst Gábor , Ötvös Sándor B. , Fülöp Ferenc , Balogh György T. , Hunyadi Attila
Published: June 2021

Curcuminoids are the main bioactive components of the well-known Asian spice and traditional medicine turmeric. Curcuminoids have poor chemical stability and bioavailability; in vivo they are rapidly metabolized to a set of bioreduced derivatives and/or glucuronide and sulfate conjugates. The reduced curcuminoid metabolites were also reported to exert various bioactivities in vitro and in vivo. In this work, we aimed to perform a comparative evaluation of curcuminoids and their hydrogenated metabolites from a medicinal chemistry point of view, by determining a set of key pharmacokinetic parameters and evaluating antioxidant potential in relation to such properties.Reduced metabolites were prepared from curcumin and demethoxycurcumin through continuous-flow hydrogenation. As selected pharmacokinetic parameters, kinetic solubility, chemical stability, metabolic stability in human liver microsomes, and parallel artificial membrane permeability assay (PAMPA)-based gastrointestinal and blood-brain barrier permeability were determined. Experimentally determined logP for hydrocurcumins in octanol-water and toluene-water systems provided valuable data on the tendency for intramolecular hydrogen bonding by these compounds. Drug likeness of the compounds were further evaluated by a in silico calculations. Antioxidant properties in diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity (ORAC) assays were comparatively evaluated through the determination of ligand lipophilic efficiency (LLE). Our results showed dramatically increased water solubility and chemical stability for the reduced metabolites as compared to their corresponding parent compound. Hexahydrocurcumin was found the best candidate for drug development based on a complex pharmacokinetical comparison and high LLE values for its antioxidant properties. Development of tetrahydrocurcumin and tetrahydro-demethoxycurcumin would be limited by their very poor metabolic stability, therefore such an effort would rely on formulations bypassing first-pass metabolism.
Açai (Euterpe oleracea Mart.) Seed Extract Induces ROS Production and Cell Death in MCF-7 Breast Cancer Cell Line
Authors: Silva Marcos Antonio Custódio Neto da , Costa Jonas Henrique , Pacheco-Fill Taícia , Ruiz Ana Lúcia Tasca Gois , Vidal Flávia Castello Branco , Borges Kátia Regina Assunção , Guimarães Sulayne Janaina Araújo , Azevedo-Santos Ana Paula Silva de , Buglio Kaio Eduardo , Foglio Mary Ann , Barbosa Maria do Carmo Lacerda , Nascimento Maria do Desterro Soares Brandão , de Carvalho João Ernesto
Published: June 2021

Euterpe oleracea Mart. (açai) is a native palm from the Amazon region. There are various chemical constituents of açai with bioactive properties. This study aimed to evaluate the chemical composition and cytotoxic effects of açai seed extract on breast cancer cell line (MCF-7). Global Natural Products Social Molecular Networking (GNPS) was applied to identify chemical compounds present in açai seed extract. LC-MS/MS and molecular networking were employed to detect the phenolic compounds of açai. The antioxidant activity of açai seed extract was measured by DPPH assay. MCF-7 breast cancer cell line viability was evaluated by MTT assay. Cell death was evaluated by flow cytometry and time-lapse microscopy. Autophagy was evaluated by orange acridin immunofluorescence assay. Reactive oxygen species (ROS) production was evaluated by DAF assay. From the molecular networking, fifteen compounds were identified, mainly phenolic compounds. The açai seed extract showed cytotoxic effects against MCF-7, induced morphologic changes in the cell line by autophagy and increased the ROS production pathway. The present study suggests that açai seed extract has a high cytotoxic capacity and may induce autophagy by increasing ROS production in breast cancer. Apart from its antioxidant activity, flavonoids with high radical scavenging activity present in açai also generated NO (nitric oxide), contributing to its cytotoxic effect and autophagy induction.
Endosomal pH-Responsive Fe-Based Hyaluronate Nanoparticles for Doxorubicin Delivery
Authors: Bae Yangmun , Kim Yoonyoung , Lee Eun Seong
Published: June 2021

In this study, we report pH-responsive metal-based biopolymer nanoparticles (NPs) for tumor-specific chemotherapy. Here, aminated hyaluronic acid (aHA) coupled with 2,3-dimethylmaleic anhydride (DMA, as a pH-responsive moiety) (aHA-DMA) was electrostatically complexed with ferrous chloride tetrahydrate (FeCl2/4H2O, as a chelating metal) and doxorubicin (DOX, as an antitumor drug model), producing DOX-loaded Fe-based hyaluronate nanoparticles (DOX@aHA-DMA/Fe NPs). Importantly, the DOX@aHA-DMA/Fe NPs improved tumor cellular uptake due to HA-mediated endocytosis for tumor cells overexpressing CD44 receptors. As a result, the average fluorescent DOX intensity observed in MDA-MB-231 cells (with CD44 receptors) was ~7.9 × 102 (DOX@HA/Fe NPs, without DMA), ~8.1 × 102 (DOX@aHA-DMA0.36/Fe NPs), and ~9.3 × 102 (DOX@aHA-DMA0.60/Fe NPs). Furthermore, the DOX@aHA-DMA/Fe NPs were destabilized due to ionic repulsion between Fe2+ and DMA-detached aHA (i.e., positively charged free aHA) in the acidic environment of tumor cells. This event accelerated the release of DOX from the destabilized NPs. Our results suggest that these NPs can be promising tumor-targeting drug carriers responding to acidic endosomal pH.
Synthesis, Structure and Electrochemical Properties of Acetamide- and Caprolactam-Containing Silicon Catecholates
Authors: Kramarova Eugenia P. , Volodin Alexander D. , Negrebetsky Vadim V. , Shagina Anastasia D. , Aliev Teimur M. , Dorovatovskii Pavel V. , Novikov Roman A. , Vologzhanina Anna V. , Korlyukov Alexander A.
Published: June 2021

Hexacoordinated heteroligand silicon catecholates, although being prospective as easily soluble compounds with high hydrolytic stability and diverse redox properties, have been insufficiently studied. The transesterification of 1-(trimethoxysilylmethyl)-2-oxohexahydroaze or N-methyl-N-(trimethoxysilylmethyl)acetamide by two equivalents of catechol derivatives in the presence of dicyclohexylamine afforded a series of target compounds in good yield. The complexes were characterized using elemental analysis, FTIR, 1H, 13C and 29Si NMR spectra, X-ray crystallography and cyclic voltammetry. X-ray diffraction confirmed that the silicon atom possesses the octahedral geometry of the SiCO5 polyhedron that remains unchanged in solution as it follows from 29Si NMR data. The compounds demonstrated up to three oxidation waves; and the reduction profile strongly depended on the nature of the substituents on a catecholate anion.
Quantitative 1H Nuclear Magnetic Resonance Method for Assessing the Purity of Dipotassium Glycyrrhizinate
Authors: Zhang Yuan-Yuan , Zhang Jie , Zhang Wen-Xuan , Wang Yue , Wang Ying-Hong , Yang Qing-Yun , Wu Song
Published: June 2021

A simple, rapid, accurate, and selective quantitative method based on 1H nuclear magnetic resonance (qNMR) was successfully established and developed for assessing the purity of dipotassium glycyrrhizinate (KG). In this study, using potassium hydrogen phthalate and fumaric acid as internal standard (IS), several important experimental parameters, such as relaxation delay and pulse angle, were explored. Reliability, specificity, linearity, limit of quantification, precision, stability, and accuracy were also validated. Calibration results obtained from qNMR were consistent with those obtained from HPLC coupled with ultraviolet detection. The proposed method, independent of the reference standard substance, is a useful, reliable, and practical protocol for the determination of KG and glycyrrhizin analogs.
Melatonin-Loaded Nanocarriers: New Horizons for Therapeutic Applications
Authors: Chuffa Luiz Gustavo de Almeida , Seiva Fábio Rodrigues Ferreira , Novais Adriana Alonso , Simão Vinícius Augusto , Martín Giménez Virna Margarita , Manucha Walter , Zuccari Debora Aparecida Pires de Campos , Reiter Russel J.
Published: June 2021

The use of nanosized particles has emerged to facilitate selective applications in medicine. Drug-delivery systems represent novel opportunities to provide stricter, focused, and fine-tuned therapy, enhancing the therapeutic efficacy of chemical agents at the molecular level while reducing their toxic effects. Melatonin (N-acetyl-5-methoxytriptamine) is a small indoleamine secreted essentially by the pineal gland during darkness, but also produced by most cells in a non-circadian manner from which it is not released into the blood. Although the therapeutic promise of melatonin is indisputable, aspects regarding optimal dosage, biotransformation and metabolism, route and time of administration, and targeted therapy remain to be examined for proper treatment results. Recently, prolonged release of melatonin has shown greater efficacy and safety when combined with a nanostructured formulation. This review summarizes the role of melatonin incorporated into different nanocarriers (e.g., lipid-based vesicles, polymeric vesicles, non-ionic surfactant-based vesicles, charge carriers in graphene, electro spun nanofibers, silica-based carriers, metallic and non-metallic nanocomposites) as drug delivery system platforms or multilevel determinations in various in vivo and in vitro experimental conditions. Melatonin incorporated into nanosized materials exhibits superior effectiveness in multiple diseases and pathological processes than does free melatonin; thus, such information has functional significance for clinical intervention.