bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility of Upper Gastrointestinal Examination in Home Care Setting with a Magnetically Assisted Capsule Endoscopy System: A Retrospective Study
Authors: Lin Yang-Chao , Chen Ching-Lin , Kao Yi-Wei , Chang Chi-Yang , Chen Ming-Chih , Liu Chih-Kuang
Published: May 2021

The magnetic assisted capsule endoscope (MACE) with a hand-held magnetic field navigator (MFN) for upper gastrointestinal examination achieved satisfactory results in a healthy volunteer study. We evaluated the feasibility of upper gastrointestinal examination in the home care setting with the MACE system. Home care patients with upper gastrointestinal symptoms that received an MACE exam were enrolled in the study. MACE procedure time; completeness of observation of important anatomical landmarks; endoscopic diagnosis; patient tolerance during the procedure; and patient data, including age, sex, comorbidities, symptoms, body weight, and height, were retrieved from hospital information system for data analysis. A total of 16 participants were enrolled with a mean age 74.3 ± 15.4 years (47 to 99 years). One patient failed to swallow the capsule and was excluded. The average procedure time was 23.7 ± 10.0 min (14.1 to 42.5 min) to complete each endoscopic exam for the remaining 15 patients. The overall maneuverability in the esophagus, stomach, and duodenum was 93.75%, 87.5%, and 75%, respectively. Overall completeness in the aforementioned regions was 93.75%, 81.25%, and 75%, respectively. No severe adverse events were noted. The results clearly demonstrate the promise of using this MACE system to perform endoscopic examination outside the hospital for patients confined to the community and home.
Dietetic Students’ Drivers and Barriers to Healthy Eating While Studying to Be a Healthcare Professional (a Pilot Study)
Authors: Trahearn Marie , Merryweather Dave , Amirabdollahian Farzad
Published: May 2021

Background: For Dietetics students, starting university means developing the knowledge and skills required to be a healthcare practitioner. This pilot study aimed to explore the perceptions and views of the students on their drivers and barriers of healthy eating while studying Dietetics at university. Methods: A qualitative study was undertaken with a purposive sample of six final year Dietetic students at a UK university. Semi-structured in-depth interviews were used to elicit students’ experiences and perceptions of barriers to healthy eating. Interview data were analysed thematically. Results: Five themes emerged from the interview data including studying Dietetics, placement, influence of significant others, food security, and social and cultural aspects of the university life, with several sub-themes, and perspectives about the future beyond the university life. Conclusions: The findings suggest a potential need for Dietetics course providers to consider the range of barriers to healthy eating that students may encounter whilst studying and how these may undermine their ability to develop healthy eating practices and effective professional skills. Further research is required that explores the extent of barriers to healthy eating and examine whether these impinge upon effective practice.
Comparative Transcriptome Analysis Reveals Different Low-Nitrogen-Responsive Genes in Pepper Cultivars
Authors: Wang Chunping , Li Yifei , Bai Wenqin , Yang Xiaomiao , Wu Hong , Lei Kairong , Huang Renzhong , Zhang Shicai , Huang Qizhong , Lin Qing
Published: May 2021

The molecular mechanisms underlying the variation in N-use efficiency (NUE) in pepper (Capsicum annuum L.) genotypes are poorly understood. In this work, two genotypes (750-1, low-N tolerant; ZCFB, low-N sensitive) with contrasting low-N tolerance were selected from 100 pepper cultivars on the basis of their relative leaf areas, shoot dry weights, root dry weights, and plant dry weights at the seedling stage. Subsequently, using RNA-Seq, the transcriptome of these two pepper genotypes under N starvation for 28 days was analyzed. We detected 2621/2470 and 3936/4218 different expressed genes (DEGs) in the leaves/roots of 750-1 and ZCFB, respectively. The changes in the expression of basic N metabolism genes were similar between 750-1 and ZCFB. However, different DEGs not directly involved in N metabolism were identified between the 750-1 and ZCFB cultivars. In 750-1, 110 unique DEGs were detected in the leaves, of which 103 were down-regulated, including genes associated with protein metabolism, photosynthesis, secondary metabolism, cell wall metabolism, stress response, and disease resistance. In ZCFB, 142 unique DEGs were detected in the roots, of which 117 were up-regulated, resulting in enhancement of processes such as protein degradation, secondary metabolites synthesis, lipid metabolism, endocytosis, the tricarboxylic acid cycle (TCA), transcriptional regulation, stress response, and disease resistance. Our results not only facilitate an understanding of the different regulatory process in low-N-tolerant and low-N-sensitive pepper cultivars, but also provide abundant candidate genes for improving the low-N tolerance of pepper cultivars.
Impacts of Land Use and Land Cover Changes on PeakDischarge and Flow Volume in Kakia and Esamburmbur Sub-Catchments of Narok Town, Kenya
Authors: Umukiza Etienne , Raude James M. , Wandera Simon M. , Petroselli Andrea , Gathenya John M.
Published: May 2021

Due to population growth and an expanding economy, land use/land cover (LULC) change is continuously intensifying and its effects on floods in Kakia and Esamburmbur sub-catchments in Narok town, Kenya, are increasing. This study was carried out in order to evaluate the influence of LULC changes on peak discharge and flow volume in the aforementioned areas. The Event-Based Approach for Small and Ungauged Basins (EBA4SUB) rainfall–runoff model was used to evaluate the peak discharge and flow volume under different assumed scenarios of LULC that were projected starting from a diachronic analysis of satellite images of 1985 and 2019. EBA4SUB simulation demonstrated how the configuration and composition of LULC affect peak discharge and flow volume in the selected catchments. The results showed that the peak discharge and flow volume are affected by the variation of the Curve Number (CN) value that is dependent on the assumed LULC scenario. The evaluated peak discharge and flow volume for the assumed LULC scenarios can be used by local Municipal bodies to mitigate floods.
Experimental Attempt on Walking Behavior and Stress Assessment in a Completely Darkened Tunnel
Authors: Seike Miho , Kawabata Nobuyoshi , Hasegawa Masato , Tsuji Chiharu , Higashida Haruhiro , Yuhi Teruko
Published: May 2021

In case of massive fire incidents in tunnels, ceiling lights are covered by dense smoke, and pedestrians must evacuate in the dark tunnel with almost zero visibility. Nonetheless, the walking behavior in a completely darkened tunnel has not been clarified. In this study, we experimentally attempted to investigate the evacuation loci and assess the stress of evacuees by measuring oxytocin and cortisol concentrations in saliva, heart rates, blood pressures, and responses in a survey questionnaire for a full-scale tunnel. Results indicated few differences in both one- and two-dimensional walking speed. In terms of stress, the group of subjects who felt stress demonstrated a walking speed that is 0.17 m/s slower than the group that did not feel it. In the questionnaire survey, most of the subjects answered that the wall was the most helpful item, followed by the unevenness (bumps) on the white lines on the road. One of the subjects became lost, stating that she could not find the unevenness (bumps) on the white lines. These two factors can be rational guides in a dense smoke environment or a completely dark tunnel scenario.
The Role of Myeloid-Derived Suppressor Cells (MDSCs) in Graft-versus-Host Disease (GVHD)
Authors: Demosthenous Christos , Sakellari Ioanna , Douka Vassiliki , Papayanni Penelope Georgia , Anagnostopoulos Achilles , Gavriilaki Eleni
Published: May 2021

Background: Myeloid-derived suppressor cells (MDSCs) are implicated in the complex interplay involving graft-versus-leukemia (GVL) effects and graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HCT) in hematologic malignancies. Methods: A review of literature through PubMed was undertaken to summarize the published evidence on the pathophysiology and clinical implications of MDSCs in allo-HCT. Literature sources published in English since 1978 were searched, using the terms Natural Suppressor (NS) cells, MDSCs, GVHD, and allo-HCT. Results: In vivo studies demonstrated that MDSCs derived from mobilization protocols could strongly suppress allo-responses mediated by T cells and enhance T-Reg activity, thus inhibiting GVHD toxicity. However, the influence of MDSCs on the GVL effect is not fully defined. Conclusions: The induction or maintenance of MDSC suppressive function would be advantageous in suppressing inflammation associated with GVHD. Pathways involved in MDSC metabolism and the inflammasome signaling are a promising field of study to elucidate the function of MDSCs in the pathogenesis of GVHD and translate these findings to a clinical setting.
Penetration of Isavuconazole in Ascites Fluid of Critically Ill Patients
Authors: Lahmer Tobias , Batres Baires Gonzalo , Schmid Roland M. , Wiessner Johannes R. , Ulrich Jörg , Reichert Maximilian , Huber Wolfgang , Sörgel Fritz , Kinzig Martina , Rasch Sebastian , Mayr Ulrich
Published: May 2021

Fungal peritonitis is a life-threatening condition which is not only difficult to diagnose, but also to treat. Following recent guidelines, echinocandins and azoles are the recommended antimycotics for the management of intra-abdominal Candida spp. infections, with a favor for echinocandins in critically ill patients. However, the new extended spectrum triazole isavuconazole also has a broad spectrum against Candida spp. Data on its target-site penetration are sparse. Therefore, we assessed isavuconazole concentrations and penetration ratios in ascites fluid of critically ill patients. Obtaining of Isavuconazole plasma and ascites fluid levels as well penetration ratios using paracentesis in critically ill patients. Isavuconazole concentrations were quantified in human plasma and ascites by a liquid chromatography/tandem mass spectrometry (LC-MS/MS) method. Isavuconazole concentrations in plasma and ascites fluid were measured in sixteen critically ill patients. Isavuconazol levels in ascites fluid (1.06 µg/mL) were lower than plasma levels (3.08 µg/mL). Penetration ratio was 36%. In two out of sixteen patients, Candida spp., in detail C. glabrata and C. tropicalis, could be isolated. Cmax/MIC Ratio in plasma of 560 for C. glabrata and 2166 for C. tropicalis could be observed. Following our results, isavuconazole penetrates into ascites. Successful treatment in Candida spp. peritonitis depends on pathogen susceptibility.
Maintenance of Maternal Breastfeeding up to 6 Months: Predictive Models
Authors: Santacruz-Salas Esmeralda , Segura-Fragoso Antonio , Pozuelo-Carrascosa Diana P. , Cobo-Cuenca Ana Isabel , Carmona-Torres Juan Manuel , Laredo-Aguilera José Alberto
Published: May 2021

Background: There is evidence of the benefits of exclusive breastfeeding (EBF) but maintaining EBF for the minimum recommended time of 6 months is challenging. Aims: This study aimed to determine the prevalence of breastfeeding types in a Spanish setting, explore the influencing factors, and analyze the relationships between the reasons for EBF cessation and the EBF durations achieved. Method: This longitudinal descriptive study included 236 healthy children with standard weight followed up by the public health system. A baseline survey and three telephone interviews (1, 3, and 6 months) were conducted. Results: The prevalence of EBF at 6 months was 19.49%. The mean age of the mothers was 32.3 (±5.3). The variables influencing EBF maintenance were the prior decision to practice EBF (p = 0.03), the belief that EBF is sufficient (p = 0.00), not offering water or fluid to the child (p = 0.04), delaying pacifier use (p < 0.001), a longer gestation time (p = 0.05), and previous experience with practicing EBF for more than 6 months (p = 0.00). The reason for the earliest EBF cessation (mean 52.63 ± 56.98 days) was the mother’s lack of self-efficacy (p = 0.05). Conclusion: Knowing the reasons for EBF cessation among mothers is important for helping mothers and preventing early weaning. A safe environment and support can prevent early weaning.
Perfusion Parameters in Near-Infrared Fluorescence Imaging with Indocyanine Green: A Systematic Review of the Literature
Authors: Goncalves Lauren N. , van den Hoven Pim , van Schaik Jan , Leeuwenburgh Laura , Hendricks Cas H. F. , Verduijn Pieter S. , van der Bogt Koen E. A. , van Rijswijk Carla S. P. , Schepers Abbey , Vahrmeijer Alexander L. , Hamming Jaap F. , van der Vorst Joost R.
Published: May 2021

(1) Background: Near-infrared fluorescence imaging is a technique capable of assessing tissue perfusion and has been adopted in various fields including plastic surgery, vascular surgery, coronary arterial disease, and gastrointestinal surgery. While the usefulness of this technique has been broadly explored, there is a large variety in the calculation of perfusion parameters. In this systematic review, we aim to provide a detailed overview of current perfusion parameters, and determine the perfusion parameters with the most potential for application in near-infrared fluorescence imaging. (2) Methods: A comprehensive search of the literature was performed in Pubmed, Embase, Medline, and Cochrane Review. We included all clinical studies referencing near-infrared perfusion parameters. (3) Results: A total of 1511 articles were found, of which, 113 were suitable for review, with a final selection of 59 articles. Near-infrared fluorescence imaging parameters are heterogeneous in their correlation to perfusion. Time-related parameters appear superior to absolute intensity parameters in a clinical setting. (4) Conclusions: This literature review demonstrates the variety of parameters selected for the quantification of perfusion in near-infrared fluorescence imaging.
Novel Algorithms for Graph Clustering Applied to Human Activities
Authors: Budimirovic Nebojsa , Bacanin Nebojsa
Published: May 2021

In this paper, a novel algorithm (IBC1) for graph clustering with no prior assumption of the number of clusters is introduced. Furthermore, an additional algorithm (IBC2) for graph clustering when the number of clusters is given beforehand is presented. Additionally, a new measure of evaluation of clustering results is given—the accuracy of formed clusters (T). For the purpose of clustering human activities, the procedure of forming string sequences are presented. String symbols are gained by modeling spatiotemporal signals obtained from inertial measurement units. String sequences provided a starting point for forming the complete weighted graph. Using this graph, the proposed algorithms, as well as other well-known clustering algorithms, are tested. The best results are obtained using novel IBC2 algorithm: T = 96.43%, Rand Index (RI) 0.966, precision rate (P) 0.918, recall rate (R) 0.929 and balanced F-measure (F) 0.923.
The Higher-Order of Adaptive Lasso and Elastic Net Methods for Classification on High Dimensional Data
Authors: Araveeporn Autcha
Published: May 2021

The lasso and elastic net methods are the popular technique for parameter estimation and variable selection. Moreover, the adaptive lasso and elastic net methods use the adaptive weights on the penalty function based on the lasso and elastic net estimates. The adaptive weight is related to the power order of the estimator. Normally, these methods focus to estimate parameters in terms of linear regression models that are based on the dependent variable and independent variable as a continuous scale. In this paper, we compare the lasso and elastic net methods and the higher-order of the adaptive lasso and adaptive elastic net methods for classification on high dimensional data. The classification is used to classify the categorical data for dependent variable dependent on the independent variables, which is called the logistic regression model. The categorical data are considered a binary variable, and the independent variables are used as the continuous variable. The high dimensional data are represented when the number of independent variables is higher than the sample sizes. For this research, the simulation of the logistic regression is considered as the binary dependent variable and 20, 30, 40, and 50 as the independent variables when the sample sizes are less than the number of the independent variables. The independent variables are generated from normal distribution on several variances, and the dependent variables are obtained from the probability of logit function and transforming it to predict the binary data. For application in real data, we express the classification of the type of leukemia as the dependent variables and the subset of gene expression as the independent variables. The criterion of these methods is to compare by the average percentage of predicted accuracy value. The results are found that the higher-order of adaptive lasso method is satisfied with large dispersion, but the higher-order of adaptive elastic net method outperforms on small dispersion.
Queuing-Inventory Models with MAP Demands and Random Replenishment Opportunities
Authors: Chakravarthy Srinivas R. , Rao B. Madhu
Published: May 2021

Combining the study of queuing with inventory is very common and such systems are referred to as queuing-inventory systems in the literature. These systems occur naturally in practice and have been studied extensively in the literature. The inventory systems considered in the literature generally include (s,S)-type. However, in this paper we look at opportunistic-type inventory replenishment in which there is an independent point process that is used to model events that are called opportunistic for replenishing inventory. When an opportunity (to replenish) occurs, a probabilistic rule that depends on the inventory level is used to determine whether to avail it or not. Assuming that the customers arrive according to a Markovian arrival process, the demands for inventory occur in batches of varying size, the demands require random service times that are modeled using a continuous-time phase-type distribution, and the point process for the opportunistic replenishment is a Poisson process, we apply matrix-analytic methods to study two of such models. In one of the models, the customers are lost when at arrivals there is no inventory and in the other model, the customers can enter into the system even if the inventory is zero but the server has to be busy at that moment. However, the customers are lost at arrivals when the server is idle with zero inventory or at service completion epochs that leave the inventory to be zero. Illustrative numerical examples are presented, and some possible future work is highlighted.
Self-Management Portfolio System with Adaptive Association Mining: A Practical Application on Taiwan Stock Market
Authors: Syu Jia-Hao , Yeh Yi-Ren , Wu Mu-En , Ho Jan-Ming
Published: May 2021

A well-established financial trading system should well perform in resource allocation, risk management, and sustainability. In this paper, we propose a self-management portfolio system with adaptive association mining for practical applications. The system allocates funds into independent units for risk management, and utilizes association mining and adaptive closing mechanism for resource allocation and sustainability, and adopts a self-management module for monitoring positions. The proposed system boosts the annual return and Sharpe ratio to 9.1% and 0.578 (increased to 2.28 and 2.48 times), and reduces the drawdown risk to 34.6% (decreased to almost half). Furthermore, the system rapidly closes the stock positions to avoid drawdown risk in the bear markets, and gradually increases the stock positions when the market turns into bull. Compared with benchmarks, proposed system outperforms all benchmarks in all measurements and on randomly sampled dataset.
Analysis of Re-Tensioning Time of Anchor Cable Based on New Prestress Loss Model
Authors: Shi Keyou , Wu Xiaoping , Tian Yurong , Xie Xiaotian
Published: May 2021

Considering the interaction among anchor cable, frame beam and rock mass, a new model of prestress loss of anchor cable was established. The accuracy and applicability of the new model were verified by comparing the field monitoring data and the calculation results of existing models. In addition, based on the new model, the effect of the re-tension of the anchor cable at different time nodes was analyzed, and the later compensation time of anchor cable prestress was discussed. The research shows that: the accuracy of the new model is higher after considering the effect of the frame beam, the new model can not only calculate the loss of prestress of anchor cable, but also accurately predict the time when the prestress of anchor cable reaches the stable stage. The ideal effect of prestress compensation can be achieved when the anchor cable is re-tensioned at each time point after 20 days of the construction completed. The original prestress loss of the anchor cable is different, and the re-tension effect is also different, the greater the loss of the original prestress of the anchor cable, the more obvious the prestress compensation effect during the re-tension.
Patients’ Prioritization on Surgical Waiting Lists: A Decision Support System
Authors: Silva-Aravena Fabián , Álvarez-Miranda Eduardo , Astudillo César A. , González-Martínez Luis , Ledezma José G.
Published: May 2021

Currently, in Chile, more than a quarter-million of patients are waiting for an elective surgical intervention. This is a worldwide reality, and it occurs as the demand for healthcare is vastly superior to the clinical resources in public systems. Moreover, this phenomenon has worsened due to the COVID-19 sanitary crisis. In order to reduce the impact of this situation, patients in the waiting lists are ranked according to a priority. However, the existing prioritization strategies are not necessarily systematized, and they usually respond only to clinical criteria, excluding other dimensions such as the personal and social context of patients. In this paper, we present a decision-support system designed for the prioritization of surgical waiting lists based on biopsychosocial criteria. The proposed system features three methodological contributions; first, an ad-hoc medical record form that captures the biopsychosocial condition of the patients; second, a dynamic scoring scheme that recognizes that patients’ conditions evolve differently while waiting for the required elective surgery; and third, a methodology for prioritizing and selecting patients based on the corresponding dynamic scores and additional clinical criteria. The designed decision-support system was implemented in the otorhinolaryngology unit in the Hospital of Talca, Chile, in 2018. When compared to the previous prioritization methodology, the results obtained from the use of the system during 2018 and 2019 show that this new methodology outperforms the previous prioritization method quantitatively and qualitatively. As a matter of fact, the designed system allowed a decrease, from 2017 to 2019, in the average number of days in the waiting list from 462 to 282 days.
Information Use and the Condorcet Jury Theorem
Authors: Morimoto Keiichi
Published: May 2021

Using a simple model of a coordination game, this paper explores how the information use of individuals affects an optimal committee size. Although enlarging the committee promotes information aggregation, it also stimulates the members’ coordination motive and distorts their voting behavior through higher-order beliefs. On the determination of a finite optimal committee size, the direction and degree of strategic interactions matter. When the strategic complementarity among members is strong, a finite optimal committee size exists. In contrast, it does not exist under strategic substitution. This mechanism is applied to the design of monetary policy committees in a New Keynesian model in which a committee conducts monetary policy under imperfect information.
Smooth kNN Local Linear Estimation of the Conditional Distribution Function
Authors: Almanjahie Ibrahim M. , Elmezouar Zouaoui Chikr , Laksaci Ali , Rachdi Mustapha
Published: May 2021

Previous works were dedicated to the functional k-Nearest Neighbors (kNN) and the local linearity method estimations of a regression operator. In this paper, a sequence pair of (Xi,Yi)i=1,…,n of functional mixing observations are considered. We treat the local linear estimation of the cumulative function of Yi given functional input variable Xi. Precisely, we combine the kNN method with the local linear algorithm to construct a new and fast efficiency estimator of the conditional distribution function. The main purpose of this paper is to prove the strong convergence of the constructed estimator under mixing conditions. An application to the functional times series prediction is used to compare our proposed estimator with the existing competitive estimators, and show its efficiency and superiority.
Inhibition of Angiogenic Factor Productions by Quercetin In Vitro and In Vivo
Authors: Okumo Takayuki , Furuta Atsuko , Kimura Tarou , Yusa Kanako , Asano Kazuhito , Sunagawa Masataka
Published: May 2021

Background: Angiogenesis is well known to be an important event in the tissue remodeling observed in allergic diseases. Although there is much evidence that quercetin, one of the most abundant dietary flavonoids, exerts anti-allergic effects in both human and experimental animal models of allergic diseases, the action of quercetin on angiogenesis has not been defined. Therefore, in this study, we first examined the action of quercetin on the secretion of angiogenic factors from murine mast cells in vitro. We also examined the action of quercetin on angiogenic factor secretion in the murine allergic rhinitis model in vivo. Methods: Mast cells (1 × 105 cells/mL) sensitized with ovalbumin (OVA)-specific murine IgE were stimulated with 10.0 ng/mL OVA in the presence or the absence of quercetin for 24 h. The concentrations of angiogenic factors, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), tumor necrosis factor-α, IL-6 and IL-8 in the supernatants were examined by ELISA. BALB/c male mice immunized with OVA were challenged intranasally with OVA every other day, starting seven days after the final immunization. These mice were then orally administered quercetin once a day for five days, starting seven days after the final immunization. Clinical symptoms were assessed by counting the number of sneezes and nasal rubbing behaviors during the 10 min period just after OVA nasal provocation. The angiogenic factor concentrations in the nasal lavage fluids obtained 6 h after nasal antigenic provocation were examined by ELISA. Results: Quercetin significantly inhibited the production of angiogenetic factors induced by IgE-dependent mechanisms at 5.0 µM or more. Oral administration of 25.0 mg/kg quercetin into the mice also suppressed the appearance of angiogenetic factors in nasal lavage fluids, along with the attenuation of nasal symptoms. Conclusions: These results strongly suggest that the inhibitory action of quercetin on angiogenic factor secretion may be implicated in the therapeutic action of quercetin on allergic diseases, especially allergic rhinitis.
Multi-Spot Ultrasonic Welding of Aluminum to Steel Sheets: Process and Fracture Analysis
Authors: Becker Michael , Balle Frank
Published: May 2021

Ultrasonic metal welding is an energy-efficient, fast and clean joining technology without the need of additional filler materials. Single spot ultrasonic metal welding of aluminum to steel sheets using automotive materials has already been investigated. Up to now, further studies to close the gap to application-relevant multi-metal structures with multiple weld spots generated are still missed. In this work, two different spot arrangements are presented, each consisting of two weld spots, joined 0.9 mm thick sheets of wrought aluminum alloy AA6005A-T4 with 1 mm sheets of galvannealed (galvanized and annealed) dual-phase steel HCT980X. An anvil equipped with variable additional clamping punches was used for the first time. The tensile shear forces reached 4076 ± 277 N for parallel connection and 3888 ± 308 N for series connection. Temperature measurements by thermocouples at the interface and through thermal imaging presented peak temperatures above 400 °C at the multi-metal interface. Microscopic investigations of fractured surfaces identified the Zn layer of the steel sheets as the strength-limiting factor. Energy-dispersive X-ray spectroscopy (EDX) indicated intermetallic phases of Fe and Zn in the border areas of the weld spots as well as the separation of the zinc layer from the steel within these areas.
Study of Diffusible Behavior of Hydrogen in First Generation Advanced High Strength Steels
Authors: Mallick Dwaipayan , Mary Nicolas , Raja V. S. , Normand Bernard
Published: May 2021

This study deals with microstructural influence on the H permeation behavior of Dual-Phase (DP) and Complex Phase (CP) steels using electrochemical permeation studies. The H diffusion coefficients in DP steels (DP800: 1.65 × 10−10 m2·s−1, DP1000: 1.58 × 10−10 m2·s−1) are half of that found in CP steels (3.07 × 10−10 m2·s−1).The banded microstructure along the specimen thickness and higher C content of the DP led to high H diffusivity of DP steels. The lower total H concentration along with a higher fraction of H was present in the stronger traps in CP steels suggest a better HE resistance of this steel. The H distribution in the specimens was non-uniform, with a higher H concentration speculated near the charging surface.
Untargeted Lipidomic Profiling of Dry Blood Spots Using SFC-HRMS
Authors: Le Faouder Pauline , Soullier Julia , Tremblay-Franco Marie , Tournadre Anthony , Martin Jean-François , Guitton Yann , Carlé Caroline , Caspar-Bauguil Sylvie , Denechaud Pierre-Damien , Bertrand-Michel Justine
Published: May 2021

Lipids are essential cellular constituents that have many critical roles in physiological functions. They are notably involved in energy storage and cell signaling as second messengers, and they are major constituents of cell membranes, including lipid rafts. As a consequence, they are implicated in a large number of heterogeneous diseases, such as cancer, diabetes, neurological disorders, and inherited metabolic diseases. Due to the high structural diversity and complexity of lipid species, the presence of isomeric and isobaric lipid species, and their occurrence at a large concentration scale, a complete lipidomic profiling of biological matrices remains challenging, especially in clinical contexts. Using supercritical fluid chromatography coupled with high-resolution mass spectrometry, we have developed and validated an untargeted lipidomic approach to the profiling of plasma and blood. Moreover, we have tested the technique using the Dry Blood Spot (DBS) method and found that it allows for the easy collection of blood for analysis. To develop the method, we performed the optimization of the separation and detection of lipid species on pure standards, reference human plasma (SRM1950), whole blood, and DBS. These analyses allowed an in-house lipid data bank to be built. Using the MS-Dial software, we developed an automatic process for the relative quantification of around 500 lipids species belonging to the 6 main classes of lipids (including phospholipids, sphingolipids, free fatty acids, sterols, and fatty acyl-carnitines). Then, we compared the method using the published data for SRM 1950 and a mouse blood sample, along with another sample of the same blood collected using the DBS method. In this study, we provided a method for blood lipidomic profiling that can be used for the easy sampling of dry blood spots.
Molecular Analysis of SARS-CoV-2 Circulating in Bangladesh during 2020 Revealed Lineage Diversity and Potential Mutations
Authors: Parvin Rokshana , Afrin Sultana Zahura , Begum Jahan Ara , Ahmed Salma , Nooruzzaman Mohammed , Chowdhury Emdadul Haque , Pohlmann Anne , Paul Shyamal Kumar
Published: May 2021

Virus evolution and mutation analyses are crucial for tracing virus transmission, the potential variants, and other pathogenic determinants. Despite continuing circulation of the SARS-CoV-2, very limited studies have been conducted on genetic evolutionary analysis of the virus in Bangladesh. In this study, a total of 791 complete genome sequences of SARS-CoV-2 from Bangladesh deposited in the GISAID database during March 2020 to January 2021 were analyzed. Phylogenetic analysis revealed circulation of seven GISAID clades G, GH, GR, GRY, L, O, and S or five Nextstrain clades 20A, 20B, 20C, 19A, and 19B in the country during the study period. The GISAID clade GR or the Nextstrain clade 20B or lineage B.1.1.25 is predominant in Bangladesh and closely related to the sequences from India, USA, Canada, UK, and Italy. The GR clade or B.1.1.25 lineage is likely to be responsible for the widespread community transmission of SARS-CoV-2 in the country during the first wave of infection. Significant amino acid diversity was observed among Bangladeshi SARS-CoV-2 isolates, where a total of 1023 mutations were detected. In particular, the D614G mutation in the spike protein (S_D614G) was found in 97% of the sequences. However, the introduction of lineage B.1.1.7 (UK variant/S_N501Y) and S_E484K mutation in lineage B.1.1.25 in a few sequences reported in late December 2020 is of particular concern. The wide genomic diversity indicated multiple introductions of SARS-CoV-2 into Bangladesh through various routes. Therefore, a continuous and extensive genome sequence analysis would be necessary to understand the genomic epidemiology of SARS-CoV-2 in Bangladesh.
Insight into the Structure of TMA-Hectorite: A Theoretical Approach
Authors: Scholtzová Eva
Published: May 2021

An ab initio density functional theory method (DFT) with D3 dispersion corrections (DFT-D3) was employed to study the 64 possible models of the structure of hectorite intercalated with tetramethylammonium (TMA) cations with the aim to find the additional information about the structure for the energetically most suitable mutual arrangement of the TMA cations. The complex analysis of total energies showed small differences among the structural models with the lowest (L model) and the highest (H model) total energy (~50 kJ/mol). The analysis of the calculated vibrational spectrum of the L model of the TMA-H structure was conducted in detail.
Investigation of the Amide Linkages on Cooperative Supramolecular Polymerization of Organoplatinum(II) Complexes
Authors: Gui Mingliang , Han Yifei , Zhong Hua , Liao Rui , Wang Feng
Published: May 2021

Cooperative supramolecular polymerization of π-conjugated compounds into one-dimensional nanostructures has received tremendous attentions in recent years. It is commonly achieved by incorporating amide linkages into the monomeric structures, which provide hydrogen bonds for intermolecular non-covalent complexation. Herein, the effect of amide linkages is elaborately studied, by comparing supramolecular polymerization behaviors of two structurally similar monomers with the same platinum(II) acetylide cores. As compared to the N-phenyl benzamide linkages, N-[(1S)-1-phenylethyl] benzamide linkages give rise to effective chirality transfer behaviors due to the closer distances between the chiral units and the platinum(II) acetylide core. They also provide stronger intermolecular hydrogen bonding strength, which consequently brings higher thermo-stability and enhanced gelation capability for the resulting supramolecular polymers. Supramolecular polymerization is further strengthened by varying the monomers from monotopic to ditopic structures. Hence, with the judicious modulation of structural parameters, the current study opens up new avenues for the rational design of supramolecular polymeric systems.
Development of a Wine Metabolomics Approach for the Authenticity Assessment of Selected Greek Red Wines
Authors: Tzachristas Alexandros , Dasenaki Marilena E. , Aalizadeh Reza , Thomaidis Nikolaos S. , Proestos Charalampos
Published: May 2021

Wine metabolomics constitutes a powerful discipline towards wine authenticity assessment through the simultaneous exploration of multiple classes of compounds in the wine matrix. Over the last decades, wines from autochthonous Greek grape varieties have become increasingly popular among wine connoisseurs, attracting great interest for their authentication and chemical characterization. In this work, 46 red wine samples from Agiorgitiko and Xinomavro grape varieties were collected from wineries in two important winemaking regions of Greece during two consecutive vintages and analyzed using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QToF-MS). A targeted metabolomics methodology was developed, including the determination and quantification of 28 phenolic compounds from different classes (hydroxycinnamic acids, hydroxybenzoic acids, stilbenes and flavonoids). Moreover, 86 compounds were detected and tentatively identified via a robust suspect screening workflow using an in-house database of 420 wine related compounds. Supervised chemometric techniques were employed to build an accurate and robust model to discriminate between two varieties.
Stereocomplex Polylactide for Drug Delivery and Biomedical Applications: A Review
Authors: Im Seung Hyuk , Im Dam Hyeok , Park Su Jeong , Chung Justin Jihong , Jung Youngmee , Kim Soo Hyun
Published: May 2021

Polylactide (PLA) is among the most common biodegradable polymers, with applications in various fields, such as renewable and biomedical industries. PLA features poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) enantiomers, which form stereocomplex crystals through racemic blending. PLA emerged as a promising material owing to its sustainable, eco-friendly, and fully biodegradable properties. Nevertheless, PLA still has a low applicability for drug delivery as a carrier and scaffold. Stereocomplex PLA (sc-PLA) exhibits substantially improved mechanical and physical strength compared to the homopolymer, overcoming these limitations. Recently, numerous studies have reported the use of sc-PLA as a drug carrier through encapsulation of various drugs, proteins, and secondary molecules by various processes including micelle formation, self-assembly, emulsion, and inkjet printing. However, concerns such as low loading capacity, weak stability of hydrophilic contents, and non-sustainable release behavior remain. This review focuses on various strategies to overcome the current challenges of sc-PLA in drug delivery systems and biomedical applications in three critical fields, namely anti-cancer therapy, tissue engineering, and anti-microbial activity. Furthermore, the excellent potential of sc-PLA as a next-generation polymeric material is discussed.
Fabrication of Porous Lead Bromide Films by Introducing Indium Tribromide for Efficient Inorganic CsPbBr3 Perovskite Solar Cells
Authors: Meng Xianwei , Chi Kailin , Li Qian , Feng Bingtao , Wang Haodi , Gao Tianjiao , Zhou Pengyu , Yang Haibin , Fu Wuyou
Published: May 2021

In the process of preparing CsPbBr3 films by two-step or multi-step methods, due to the low solubility of CsBr in organic solvents, the prepared perovskite films often have a large number of holes, which is definitely not conducive to the performance of CsPbBr3 perovskite solar cells (PSCs). In response to this problem, this article proposed a method of introducing InBr3 into the PbBr2 precursor to prepare a porous PbBr2 film to increase the reaction efficiency between CsBr and PbBr2 and achieve the purpose of In (Ⅲ) incorporation, which not only optimized the morphology of the produced CsPbBr3 film but also enhanced the charge extraction and transport capabilities, which was ascribed to the reduction of the trap state density and impurity phases in the perovskite films, improving the performance of CsPbBr3 PSCs. At the optimal InBr3 concentration of 0.21 M, the InBr3:CsPbBr3 perovskite solar cell exhibited a power conversion efficiency of 6.48%, which was significantly higher than that of the pristine device.
Effect of the Helium Background Gas Pressure on the Structural and Optoelectronic Properties of Pulsed-Laser-Deposited PbS Thin Films
Authors: Rebhi Ameni , Hajjaji Anouar , Leblanc-Lavoie Joël , Aouida Salma , Gaidi Mounir , Bessais Brahim , El Khakani My Ali
Published: May 2021

This work focuses on the dependence of the features of PbS films deposited by pulsed laser deposition (PLD) subsequent to the variation of the background pressure of helium (PHe). The morphology of the PLD-PbS films changes from a densely packed and almost featureless structure to a columnar and porous one as the He pressure increases. The average crystallite size related to the (111) preferred orientation increases up to 20 nm for PHe ≥ 300 mTorr. The (111) lattice parameter continuously decreases with increasing PHe values and stabilizes at PHe ≥ 300 mTorr. A downshift transition of the Raman peak of the main phonon (1LO) occurs from PHe = 300 mTorr. This transition would result from electron–LO–phonon interaction and from a lattice contraction. The optical bandgap of the films increases from 1.4 to 1.85 eV as PHe increases from 50 to 500 mTorr. The electrical resistivity of PLD-PbS is increased with PHe and reached its maximum value of 20 Ω·cm at PHe = 300 mTorr (400 times higher than 50 mTorr), which is probably due to the increasing porosity of the films. PHe = 300 mTorr is pointed out as a transitional pressure for the structural and optoelectronic properties of PLD-PbS films.
Comparative Modeling of Frequency Mixing Measurements of Magnetic Nanoparticles Using Micromagnetic Simulations and Langevin Theory
Authors: Engelmann Ulrich M. , Shalaby Ahmed , Shasha Carolyn , Krishnan Kannan M. , Krause Hans-Joachim
Published: May 2021

Dual frequency magnetic excitation of magnetic nanoparticles (MNP) enables enhanced biosensing applications. This was studied from an experimental and theoretical perspective: nonlinear sum-frequency components of MNP exposed to dual-frequency magnetic excitation were measured as a function of static magnetic offset field. The Langevin model in thermodynamic equilibrium was fitted to the experimental data to derive parameters of the lognormal core size distribution. These parameters were subsequently used as inputs for micromagnetic Monte-Carlo (MC)-simulations. From the hysteresis loops obtained from MC-simulations, sum-frequency components were numerically demodulated and compared with both experiment and Langevin model predictions. From the latter, we derived that approximately 90% of the frequency mixing magnetic response signal is generated by the largest 10% of MNP. We therefore suggest that small particles do not contribute to the frequency mixing signal, which is supported by MC-simulation results. Both theoretical approaches describe the experimental signal shapes well, but with notable differences between experiment and micromagnetic simulations. These deviations could result from Brownian relaxations which are, albeit experimentally inhibited, included in MC-simulation, or (yet unconsidered) cluster-effects of MNP, or inaccurately derived input for MC-simulations, because the largest particles dominate the experimental signal but concurrently do not fulfill the precondition of thermodynamic equilibrium required by Langevin theory.
Spin-Resolved Quantum Scars in Confined Spin-Coupled Two-Dimensional Electron Gas
Authors: Berger Michael , Schulz Dominik , Berakdar Jamal
Published: May 2021

Quantum scars refer to an enhanced localization of the probability density of states in the spectral region with a high energy level density. Scars are discussed for a number of confined pure and impurity-doped electronic systems. Here, we studied the role of spin on quantum scarring for a generic system, namely a semiconductor-heterostructure-based two-dimensional electron gas subjected to a confining potential, an external magnetic field, and a Rashba-type spin-orbit coupling. Calculating the high energy spectrum for each spin channel and corresponding states, as well as employing statistical methods known for the spinless case, we showed that spin-dependent scarring occurs in a spin-coupled electronic system. Scars can be spin mixed or spin polarized and may be detected via transport measurements or spin-polarized scanning tunneling spectroscopy.
Exploiting the Potential of Biosilica from Rice Husk as Porous Support for Catalytically Active Iron Oxide Nanoparticles
Authors: Franco Ana , Luque Rafael , Carrillo-Carrión Carolina
Published: May 2021

Biomass-derived materials are put forward as eco-friendly alternatives to design heterogeneous catalysts. To contribute in this field, we explored the potential of mesoporous biogenic silica (RH-Silica) obtained from lignocellulosic waste, in particular from rice husk, as an inorganic support to prepare heterogenized iron oxide-based catalysts. Mechanochemistry, considered as a green and sustainable technique, was employed to synthetize iron oxide nanoparticles in pure hematite phase onto the biosilica (α-Fe2O3/RH-Silica), making this material a good candidate to perform catalyzed organic reactions. The obtained material was characterized by different techniques, and its catalytic activity was tested in the selective oxidation of styrene under microwave irradiation. α-Fe2O3/RH-Silica displayed a good catalytic performance, achieving a conversion of 45% under optimized conditions, and more importantly, with a total selectivity to benzaldehyde. Furthermore, a good reusability was achieved without decreasing its activity after multiple catalytic cycles. This work represents a good example of using sustainable approaches and green materials as alternatives to conventional methods in the production of high-added value products.
Silver Nanoparticles Conjugated with Contact Lens Solutions May Reduce the Risk of Acanthamoeba Keratitis
Authors: Hendiger Edyta B. , Padzik Marcin , Sifaoui Inés , Reyes-Batlle María , López-Arencibia Atteneri , Zyskowska Diana , Grodzik Marta , Pietruczuk-Padzik Anna , Hendiger Jacek , Olędzka Gabriela , Chomicz Lidia , Piñero José E. , Lorenzo-Morales Jacob
Published: May 2021

Acanthamoeba keratitis (AK), a severe sight-threatening corneal infection, has become a significant medical problem, especially among contact lens wearers. The disease manifests as eye pain, congestion, blurred vision, lachrymation, and ring-shaped infiltrates of the cornea, and can lead to permanent blindness. Inappropriate habits of contact lens users may result in an increased risk of AK infection. The anti-amoebic efficiency of popular multipurpose contact lens solutions is insufficient to reduce this risk. An effective and non-toxic therapy against AK has not yet been developed. The prevention of AK is crucial to reduce the number of AK infections. Nanoparticles are known to be active agents against bacteria, viruses, and fungi and were also recently tested against protozoa, including Acanthamoeba spp. In our previous studies, we proved the anti-amoebic and anti-adhesive activity of silver nanoparticles against Acanthamoeba castellanii. The aim of this study is to evaluate the activity, cytotoxicity, and anti-adhesive properties of silver nanoparticles conjugated with five commonly used multipurpose contact lens solutions against the Acanthamoeba castellanii NEFF strain. The obtained results show a significant increase in anti-amoebic activity, without increasing the overall cytotoxicity, of Solo Care Aqua and Opti Free conjugated with nanoparticles. The adhesion of Acanthamoeba trophozoites to the contact lens surface is also significantly reduced. We conclude that low concentrations of silver nanoparticles can be used as an ingredient in contact lens solutions to decrease the risk of Acanthamoeba keratitis infection.