bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the Impact of Restricted Partners’ Visiting Policies on Non-Infected Mothers’ Mental Health and Breastfeeding Rates during the COVID-19 Pandemic
Authors: Morniroli Daniela , Consales Alessandra , Colombo Lorenzo , Bezze Elena Nicoletta , Zanotta Lidia , Plevani Laura , Fumagalli Monica , Mosca Fabio , Giannì Maria Lorella
Published: June 2021

Changes in perinatal care occurring during the coronavirus disease 2019 (COVID-19) pandemic may negatively affect mothers’ mental health and breastfeeding. This study, performed between April and May 2020, aimed to investigate the effect of restricted partners’ visiting policies on non-infected mother’s anxiety symptoms, the perceived postpartum support, and the breastfeeding outcomes at discharge. A cross-sectional study was conducted in a neonatal tertiary referral center in northern Italy during Italy’s lockdown. We enrolled mothers with a negative nasopharyngeal swab for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), adequate oral and written comprehension of the Italian language, and absence of underlying maternal or neonatal clinical conditions. Maternal anxiety levels were assessed through the State-Trait Anxiety Inventory-Form Y (STAI-Y). Maternal perception of staff’s support was evaluated by the Nurse Parent Support Tool (NPST). A STATE-A (concurrent emotional state after a specific situation) score ≥ 40 was considered indicative of clinically significant symptoms of anxiety. A total of 109 mothers completed the study. Mean STATE-A score was ≥40 in 42% of mothers, and median NPST score was 4.23. Mothers separated from their partner had a mean STATE-A score ≥ 40 in a higher percentage of cases than those who were not (51% vs. 30%, p = 0.03) and a lower perception of caregiver support. A NPST score ≤4.23, partner ‘s absence during the hospital stay and primiparity were independently associated with a STATE-A score ≥ 40. Breastfeeding rates at discharge were not influenced by maternal anxiety levels and partner’s restricted policies. Instead, they were influenced by mode of delivery, a well-known risk factor, and pre-pandemic intention to breastfeed. Our study demonstrates the positive impact of a partner’s presence on maternal mental health and perception of caregiver support.
Association of Rotating Night Shift Work with Body Fat Percentage and Fat Mass Index among Female Steelworkers in North China
Authors: Zhang Shengkui , Wang Han , Wang Yongbin , Yu Miao , Yuan Juxiang
Published: June 2021

The aim of this study was to evaluate the associations of rotating night shift work with body fat percentage (BF%) and fat mass index (FMI). A cross-sectional study was conducted among 435 female steelworkers, aged 26–57 years in Tangshan, China. BF% was assessed via bioelectrical impedance analysis and FMI was calculated. Different exposure metrics of night shift work were used to examine the effects of night shift work on BF% and FMI. The duration (years), cumulative number (nights), and cumulative length of night shifts (hours) were positively correlated with FMI and BF%, and these relationships were independent of body mass index (BMI). Compared with day workers, night shift workers with an average frequency of night shifts >7 nights/month (odds ratio (OR) 2.50, 95% confidence interval (CI) 1.17 to 5.35) and percentage of hours on night shifts >30% (OR 2.55, 95% CI 1.21 to 5.39) had elevated odds of obesity (BF% ≥ 35.0%). Nonobese night shift workers by the BMI criterion should also be alert to the risk of the excess accumulation of body fat, which is actually responsible for most obesity-associated adverse health consequences. Health interventions for related populations need to be improved, which is currently more focused on overall weight control.
Estimating the Burden of Alcohol on Ambulance Callouts through Development and Validation of an Algorithm Using Electronic Patient Records
Authors: Manca Francesco , Lewsey Jim , Waterson Ryan , Kernaghan Sarah M. , Fitzpatrick David , Mackay Daniel , Angus Colin , Fitzgerald Niamh
Published: June 2021

Background: Alcohol consumption places a significant burden on emergency services, including ambulance services, which often represent patients’ first, and sometimes only, contact with health services. We aimed to (1) improve the assessment of this burden on ambulance services in Scotland using a low-cost and easy to implement algorithm to screen free-text in electronic patient record forms (ePRFs), and (2) present estimates on the burden of alcohol on ambulance callouts in Scotland. Methods: Two paramedics manually reviewed 5416 ePRFs to make a professional judgement of whether they were alcohol-related, establishing a gold standard for assessing our algorithm performance. They also extracted all words or phrases relating to alcohol. An automatic algorithm to identify alcohol-related callouts using free-text in EPRs was developed using these extracts. Results: Our algorithm had a specificity of 0.941 and a sensitivity of 0.996 in detecting alcohol-related callouts. Applying the algorithm to all callout records in Scotland in 2019, we identified 86,780 (16.2%) as alcohol-related. At weekends, this percentage was 18.5%. Conclusions: Alcohol-related callouts constitute a significant burden on the Scottish Ambulance Service. Our algorithm is significantly more sensitive than previous methods used to identify alcohol-related ambulance callouts. This approach and the resulting data have potential for the evaluation of alcohol policy interventions as well as for conducting wider epidemiological research.
Characterization and Transcriptome Analysis of a Long-Chain n-Alkane-Degrading Strain Acinetobacter pittii SW-1
Authors: Kong Weina , Zhao Cheng , Gao Xingwang , Wang Liping , Tian Qianqian , Liu Yu , Xue Shuwen , Han Zhuang , Chen Fulin , Wang Shiwei
Published: June 2021

Strain sw-1, isolated from 7619-m seawater of the Mariana Trench, was identified as Acinetobacter pittii by 16S rRNA gene and whole-genome sequencing. A. pittii sw-1 was able to efficiently utilize long-chain n-alkanes (C18–C36), but not short- and medium-chain n-alkanes (C8–C16). The degradation rate of C20 was 91.25%, followed by C18, C22, C24, C32, and C36 with the degradation rates of 89.30%, 84.03%, 80.29%, 30.29%, and 13.37%, respectively. To investigate the degradation mechanisms of n-alkanes for this strain, the genome and the transcriptome analyses were performed. Four key alkane hydroxylase genes (alkB, almA, ladA1, and ladA2) were identified in the genome. Transcriptomes of strain sw-1 grown in C20 or CH3COONa (NaAc) as the sole carbon source were compared. The transcriptional levels of alkB and almA, respectively, increased 78.28- and 3.51-fold in C20 compared with NaAc, while ladA1 and ladA2 did not show obvious change. The expression levels of other genes involved in the synthesis of unsaturated fatty acids, permeases, membrane proteins, and sulfur metabolism were also upregulated, and they might be involved in n-alkane uptake. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) confirmed that alkB expression was significantly induced by C20, C24, and C32, and almA induction extent by C24 and C32 was higher than that with C20. Furthermore, ladA2 expression was only induced by C32, and ladA1 expression was not induced by any of n-alkanes. In addition, A. pittii sw-1 could grow with 0%–3% NaCl or 8 out of 10 kinds of the tested heavy metals and degrade n-alkanes at 15 °C. Taken together, these results provide comprehensive insights into the degradation of long-chain n-alkanes by Acinetobacter isolated from the deep ocean environment.
Indigenous Community-Led Programs to Address Food and Water Security: Protocol for a Systematic Review
Authors: Hart Ashleigh Chanel , Rosewarne Emalie , Spencer Wendy , McCausland Ruth , Leslie Greg , Shanthosh Janani , Corby Christine , Bennett-Brook Keziah , Webster Jacqui
Published: June 2021

The connection between indigenous peoples and Country (a multidimensional concept including land and water) enabled communities to thrive and survive over millennia. This has been eroded by colonisation, dispossession and increasing food and water insecurity due to climate change and supply constraints. Globally, indigenous peoples experience a disproportionate burden of chronic disease and poor nutrition is a major risk factor. Indigenous leaders have been advocating for community-led solutions. The primary aim of this systematic review is to determine what community-led programs have been undertaken to address food and/or water security globally. A comprehensive search of peer-reviewed literature will be performed in EMBASE, CINAHL, PsycINFO, PubMed, Scopus, LILACs, Informit and Business Source Premier. The grey literature search will include grey literature databases, customised Google search engines, targeted websites, and consultation with experts. The search strategy will consist of four concepts, combined as follows: (1) indigenous peoples AND (2) community program AND (3) food security OR (4) water security. Covidence will be used for study screening and data extraction by two authors. A deductive thematic analysis using indigenous-informed methodologies will be used to synthesise data. This review seeks to provide insight on models and mechanisms to encourage action and metrics for quantifying success of indigenous community-led programs to improve food and water security.
Perceived Risk Factors for Suicide among Nepalese Migrant Workers in South Korea
Authors: Atteraya Madhu Sudhan , Ebrahim Nasser B. , Gnawali Shreejana
Published: June 2021

(1) Background: In South Korea, far from their homeland, Nepalese migrant workers often face tremendous challenges. The most severe outcome for migrant workers is death by suicide—a major cause of premature death among migrant workers. Nevertheless, in the literature, key factors associated with suicide among Nepalese migrant workers are not specifically identified. Thus, we aimed to delineate the main suicide risk factors for this group of migrants. (2) Methods: We used qualitative research methodology (sample = 20; male =17, female = 3) and employed nominal group techniques to identify the perceived primary risk factors for suicide. (3) Results: Study participants identified and ranked eight sources of distress and perceived risks for suicide, both from home and in the host country. Perceived risks for suicide include a complex set of socio-cultural, behavioral, occupational, physical, and mental health issues as well as communication barriers. (4) Conclusions: The findings suggest the need to design tailored mental health promotion programs for migrant workers before departure from Nepal as well as after arrival as migrant workers in South Korea.
PML Differentially Regulates Growth and Invasion in Brain Cancer
Authors: Tampakaki Maria , Oraiopoulou Mariam-Eleni , Tzamali Eleftheria , Tzedakis Giorgos , Makatounakis Takis , Zacharakis Giannis , Papamatheakis Joseph , Sakkalis Vangelis
Published: June 2021

Glioblastoma is the most malignant brain tumor among adults. Despite multimodality treatment, it remains incurable, mainly because of its extensive heterogeneity and infiltration in the brain parenchyma. Recent evidence indicates dysregulation of the expression of the Promyelocytic Leukemia Protein (PML) in primary Glioblastoma samples. PML is implicated in various ways in cancer biology. In the brain, PML participates in the physiological migration of the neural progenitor cells, which have been hypothesized to serve as the cell of origin of Glioblastoma. The role of PML in Glioblastoma progression has recently gained attention due to its controversial effects in overall Glioblastoma evolution. In this work, we studied the role of PML in Glioblastoma pathophysiology using the U87MG cell line. We genetically modified the cells to conditionally overexpress the PML isoform IV and we focused on its dual role in tumor growth and invasive capacity. Furthermore, we targeted a PML action mediator, the Enhancer of Zeste Homolog 2 (EZH2), via the inhibitory drug DZNeP. We present a combined in vitro–in silico approach, that utilizes both 2D and 3D cultures and cancer-predictive computational algorithms, in order to differentiate and interpret the observed biological results. Our overall findings indicate that PML regulates growth and invasion through distinct cellular mechanisms. In particular, PML overexpression suppresses cell proliferation, while it maintains the invasive capacity of the U87MG Glioblastoma cells and, upon inhibition of the PML-EZH2 pathway, the invasion is drastically eliminated. Our in silico simulations suggest that the underlying mechanism of PML-driven Glioblastoma physiology regulates invasion by differential modulation of the cell-to-cell adhesive and diffusive capacity of the cells. Elucidating further the role of PML in Glioblastoma biology could set PML as a potential molecular biomarker of the tumor progression and its mediated pathway as a therapeutic target, aiming at inhibiting cell growth and potentially clonal evolution regarding their proliferative and/or invasive phenotype within the heterogeneous tumor mass.
Amyloid Beta-Mediated Changes in Synaptic Function and Spine Number of Neocortical Neurons Depend on NMDA Receptors
Authors: Back Michaela K. , Ruggieri Sonia , Jacobi Eric , von Engelhardt Jakob
Published: June 2021

Onset and progression of Alzheimer’s disease (AD) pathophysiology differs between brain regions. The neocortex, for example, is a brain region that is affected very early during AD. NMDA receptors (NMDARs) are involved in mediating amyloid beta (Aβ) toxicity. NMDAR expression, on the other hand, can be affected by Aβ. We tested whether the high vulnerability of neocortical neurons for Aβ-toxicity may result from specific NMDAR expression profiles or from a particular regulation of NMDAR expression by Aβ. Electrophysiological analyses suggested that pyramidal cells of 6-months-old wildtype mice express mostly GluN1/GluN2A NMDARs. While synaptic NMDAR-mediated currents are unaltered in 5xFAD mice, extrasynaptic NMDARs seem to contain GluN1/GluN2A and GluN1/GluN2A/GluN2B. We used conditional GluN1 and GluN2B knockout mice to investigate whether NMDARs contribute to Aβ-toxicity. Spine number was decreased in pyramidal cells of 5xFAD mice and increased in neurons with 3-week virus-mediated Aβ-overexpression. NMDARs were required for both Aβ-mediated changes in spine number and functional synapses. Thus, our study gives novel insights into the Aβ-mediated regulation of NMDAR expression and the role of NMDARs in Aβ pathophysiology in the somatosensory cortex.
Synthesis of Caffeoyl-Prolyl-Histidyl-Xaa Derivatives and Evaluation of Their Activities and Stability upon Long-Term Storage
Authors: Jeong Hyeri , Jeon Young-Eun , Yang Jin-Kyoung , Kim Jaehi , Chung Woo-Jae , Lee Yoon-Sik , Shin Dong-Sik
Published: June 2021

Antioxidants play a critical role in the treatment of degenerative diseases and delaying the aging of dermal tissue. Caffeic acid (CA) is a representative example of the antioxidants found in plants. However, CA is unsuitable for long-term storage because of its poor stability under ambient conditions. Caffeoyl-Pro-His-NH2 (CA-Pro-His-NH2, CA-PH) exhibits the highest antioxidant activity, free radical scavenging and lipid peroxidation inhibition activity among the histidine-containing CA-conjugated dipeptides reported to date. The addition of short peptides to CA, such as Pro-His, is assumed to synergistically enhance its antioxidative activity. In this study, several caffeoyl-prolyl-histidyl-Xaa-NH2 derivatives were synthesized and their antioxidative activities evaluated. CA-Pro-His-Asn-NH2 showed enhanced antioxidative activity and higher structural stability than CA-PH, even after long-term storage. CA-Pro-His-Asn-NH2 was stable for 3 months, its stability being evaluated by observing the changes in its NMR spectra. Moreover, the solid-phase synthetic strategy used to prepare these CA-Pro-His-Xaa-NH2 derivatives was optimized for large-scale production. We envision that CA-Pro-His-Xaa-NH2 derivatives can be used as potent dermal therapeutic agents and useful cosmetic ingredients.
The Environmental Effects on Virulence Factors and the Antifungal Susceptibility of Cryptococcus neoformans
Authors: Momin Mahek , Webb Ginny
Published: June 2021

Cryptococcus neoformans is a facultative intracellular pathogen responsible for fungal meningoencephalitis primarily in immunocompromised individuals. It has become evident the pathogenicity of C. neoformans is dependent on the fungal cell’s environment. The differential expression of virulence factors, based on the cell’s environmental conditions, is one mechanism allowing for the environmental control of the pathogenic ability of C. neoformans. Here, we discuss how these virulence factors (including melanin, the polysaccharide capsule, and Antiphagocytic protein 1) have been shown to be differentially expressed dependent on the cell’s environment. The genetics and signaling pathways leading to the environmental-dependent regulation of virulence factors will also be examined. Susceptibility to antifungal therapeutics is also regulated by the environment, and thus affects the pathogenic abilities of C. neoformans and disease outcomes. This review will also examine the role of the C. neoformans’s environment on antifungal susceptibilities, and the genetics and signaling pathways responsible for these susceptibility alterations. By examining the complex interplay between the environment and the pathogenicity of C. neoformans, we have a better understanding of the intricacies of the pathogen–environment interaction and how to exploit this interaction to develop the most effective treatment protocols.
Molecular Mechanisms Regulating the DNA Repair Protein APE1: A Focus on Its Flexible N-Terminal Tail Domain
Authors: López David J. , Rodríguez José A. , Bañuelos Sonia
Published: June 2021

APE1 (DNA (apurinic/apyrimidinic site) endonuclease 1) is a key enzyme of one of the major DNA repair routes, the BER (base excision repair) pathway. APE1 fulfils additional functions, acting as a redox regulator of transcription factors and taking part in RNA metabolism. The mechanisms regulating APE1 are still being deciphered. Structurally, human APE1 consists of a well-characterized globular catalytic domain responsible for its endonuclease activity, preceded by a conformationally flexible N-terminal extension, acquired along evolution. This N-terminal tail appears to play a prominent role in the modulation of APE1 and probably in BER coordination. Thus, it is primarily involved in mediating APE1 localization, post-translational modifications, and protein–protein interactions, with all three factors jointly contributing to regulate the enzyme. In this review, recent insights on the regulatory role of the N-terminal region in several aspects of APE1 function are covered. In particular, interaction of this region with nucleophosmin (NPM1) might modulate certain APE1 activities, representing a paradigmatic example of the interconnection between various regulatory factors.
A Review of Completed and Ongoing Complement Inhibitor Trials for Geographic Atrophy Secondary to Age-Related Macular Degeneration
Authors: Halawa Omar A. , Lin Jonathan B. , Miller Joan W. , Vavvas Demetrios G.
Published: June 2021

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness among older adults in the Western world. While therapies exist for patients with exudative AMD, there are currently no approved therapies for non-exudative AMD and its advanced form of geographic atrophy (GA). The discovery of genetic variants in complement protein loci with increased susceptibility to AMD has led to the investigation of the role of complement inhibition in AMD with a focus on GA. Here, we review completed and ongoing clinical trials evaluating the safety and efficacy of these studies. Overall, complement inhibition in GA has yielded mixed results. The inhibition of complement factor D has failed pivotal phase 3 trials. Studies of C3 and C5 inhibition meeting their primary endpoint are limited by high rates of discontinuation and withdrawal in the treatment arm and higher risks of conversion to exudative AMD. Studies evaluating other complement members (CFB, CFH, CFI and inhibitors of membrane attack complex—CD59) are ongoing and could offer other viable strategies.
Pathophysiological Implications of Imbalances in Fibroblast Growth Factor 23 in the Development of Diabetes
Authors: Donate-Correa Javier , Martín-Núñez Ernesto , González-Luis Ainhoa , Ferri Carla M. , Luis-Rodríguez Desirée , Tagua Víctor G. , Mora-Fernández Carmen , Navarro-González Juan F.
Published: June 2021

Observational studies have associated the increase in fibroblast growth factor (FGF) 23 levels, the main regulator of phosphate levels, with the onset of diabetes. These studies open the debate on the plausible existence of undescribed diabetogenic mechanisms derived from chronic supraphysiological levels of FGF23, a prevalent condition in chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. These maladaptive and diabetogenic responses to FGF23 may occur at different levels, including a direct effect on the pancreatic ß cells, and an indirect effect derived from the stimulation of the synthesis of pro-inflammatory factors. Both mechanisms could be mediated by the binding of FGF23 to noncanonical receptor complexes with the subsequent overactivation of signaling pathways that leads to harmful effects. The canonical binding of FGF23 to the receptor complex formed by the receptor FGFR1c and the coreceptor αKlotho activates Ras/MAPK/ERK signaling. However, supraphysiological concentrations of FGF23 favor non-αKlotho-dependent binding of this molecule to other FGFRs, which could generate an undesired overactivation of the PLCγ/CN/NFAT pathway, as observed in cardiomyocytes and hepatocytes. Moreover, the decrease in αKlotho expression may constitute a contributing factor to the appearance of these effects by promoting the nonspecific activation of the PLCγ/CN/NFAT to the detriment of the αKlotho-dependent Ras/MAPK/ERK pathway. The description of these mechanisms would allow the development of new therapeutic targets susceptible to be modified by dietary changes or by pharmacological intervention.
Relevance of Adopting a Hybrid Strategy Mixing Single-Use and Reusable Ureteroscopes for Stones Management: An Economic Study to Support the Best Strategy
Authors: Monmousseau Fanny , Ramillon Julien , Dubnitskiy-Robin Sophie , Faivre d’Arcier Benjamin , Le Verger Martine , Le Fol Tanguy , Bruyère Franck , Rusch Emmanuel , Brunet-Houdard Solène , Pradère Benjamin
Published: June 2021

Endoscopic procedures such as ureteroscopy (URS) have seen a recent increase in single-use devices. Despite all the advantages provided by disposable ureteroscopes (sURSs), their cost effectiveness remains questionable, leading most teams to use a hybrid strategy combining reusable (rURS) and disposable devices. Our study aimed to create an economic model that estimated the cut-off value of rURS procedures needed to support the profitability of a hybrid strategy (HS) for ureteroscopy. We used a budget impact analysis (BIA) model that estimated the financial impact of an HS compared to 100% sURS use. The model included hospital volume, sterilization costs and the private or public status of the institution. Although the hybrid strategy generally remains the best economic and clinical option, a predictive BIA model is recommended for the decision-making. We found that the minimal optimal proportion of rURS procedures in an HS was mainly impacted by the activity volume and overall number of sterilization procedures. Private and public institutions must consider these variables and models in order to adapt their HS and remain profitable.
Changes in Coastal Agricultural Land Use in Response to Climate Change: An Assessment Using Satellite Remote Sensing and Household Survey Data in Tien Hai District, Thai Binh Province, Vietnam
Authors: Nong Duong H. , Ngo An T. , Nguyen Hoa P. T. , Nguyen Thuy T. , Nguyen Lan T. , Saksena Summet
Published: June 2021

We analyzed the agricultural land-use changes in the coastal areas of Tien Hai district, Thai Binh province, in 2005, 2010, 2015, and 2020, using Landsat 5 and Landsat 8 data. We used the object-oriented classification method with the maximum likelihood algorithm to classify six types of land uses. The series of land-use maps we produced had an overall accuracy of more than 80%. We then conducted a spatial analysis of the 5-year land-use change using ArcGIS software. In addition, we surveyed 150 farm households using a structured questionnaire regarding the impacts of climate change on agricultural productivity and land uses, as well as farmers’ adaptation and responses. The results showed that from 2005 to 2020, cropland decreased, while aquaculture land and forest land increased. We observed that the most remarkable decreases were in the area of rice (485.58 ha), the area of perennial crops (109.7 ha), and the area of non-agricultural land (747.35 ha). The area of land used for aquaculture and forest increased by 566.88 ha and 772.60 ha, respectively. We found that the manifestations of climate change, such as extreme weather events, saltwater intrusion, drought, and floods, have had a profound impact on agricultural production and land uses in the district, especially for annual crops and aquaculture. The results provide useful information for state authorities to design land-management strategies and solutions that are economic and effective in adapting to climate change.
Reflexive and Reciprocal Encoding in the Australian Mixed Language, Light Warlpiri
Authors: O’Shannessy Carmel , Brown Connor
Published: June 2021

Mixed languages combine significant amounts of grammatical and lexical material from more than one source language in systematic ways. The Australian mixed language, Light Warlpiri, combines nominal morphology from Warlpiri with verbal morphology from Kriol (an English-lexified Creole) and English, with innovations. The source languages of Light Warlpiri differ in how they encode reflexives and reciprocals—Warlpiri uses an auxiliary clitic for both reflexive and reciprocal expression, while English and Kriol both use pronominal forms, and largely have separate forms for reflexives and reciprocals. English distinguishes person and number in reflexives, but not in reciprocals; the other source languages do not distinguish person or number. This study draws on naturalistic and elicited production data to examine how reflexive and reciprocal events are encoded in Light Warlpiri. The study finds that Light Warlpiri combines near-maximal distinctions from the source languages, but in a way that is not a mirror of any. It retains the person and number distinctions of English reflexives and extends them to reciprocals, using the same forms for reflexives and reciprocals (like Warlpiri). Reflexives and reciprocals occur within a verbal structure (perhaps under influence from Warlpiri). The results show that a mixed language can have discrete contributions from three languages, that the source languages can influence different subsystems to different extents, and that near-maximal distinctions from the source languages can be maintained.
Radiological Risk to Human and Non-Human Biota Due to Radioactivity in Coastal Sand and Marine Sediments, Gulf of Oman
Authors: Suliman Ibrahim I. , Alsafi Khalid
Published: June 2021

Natural and 137Cs radioactivity in coastal marine sediment samples was measured using gamma spectrometry. Samples were collected at 16 locations from four beaches along the coastal area of Muscat City, Gulf of Oman. Radioactivity in beach sand was used to estimate the radiological risk parameters to humans, whereas the radioactivity in marine sediments was used to assess the radiological risk parameters to non-human biota, using the ERICA Tool. The average radioactivity concentrations (Bqkg−1) of 226Ra, 232Th, 40K, 210Pb and 137Cs in sediments (sand) were as follows: 16.2 (16.3), 34.5(27.8), 54.7 (45.6), 46.8 (44.9) and 0.08 (0.10), respectively. In sand samples, the estimated average indoor (Din) and outdoor (Dout) air absorbed dose rates due to natural radioactivity were 49.26 and 27.4 and the total effective dose (AEDTotal; µSvy−1) ranged from 150.2 to 498.9 (average: 275.2). The measured radioactivity resulted in an excess lifetime cancer risk (ELCR) in the range of 58–203 (average: 111) in and an average gonadal dose (AGD; µGy.y−1) ranged from 97.3 to 329.5 (average: 181.1). Total dose rate per marine organism ranged from 0.035 µGy h−1 (in zooplankton) to 0.564 µGy h−1 (in phytoplankton). The results showed marine sediments as an important source of radiation exposure to biota in the aquatic environment. Regular monitoring of radioactivity levels is vital for radiation risk confinement. The results provide an important radiological risk profile parameter to which future radioactivity levels in marine environments can be compared.
Enhanced Optical and Antibacterial Activity of Hydrothermally Synthesized Cobalt-Doped Zinc Oxide Cylindrical Microcrystals
Authors: Khalid Awais , Ahmad Pervaiz , Alharthi Abdulrahman I. , Muhammad Saleh , Khandaker Mayeen Uddin , Faruque Mohammad Rashed Iqbal , Khan Abdulhameed , Din Israf Ud , Alotaibi Mshari A. , Alzimami Khalid , Alfuraih Abdulrahman A. , Bradley David A.
Published: June 2021

Cobalt (Co) doped zinc oxide (ZnO) microcrystals (MCs) are prepared by using the hydrothermal method from the precursor’s mixture of zinc chloride (ZnCl2), cobalt-II chloride hexahydrate (CoCl2·6H2O), and potassium hydroxide (KOH). The smooth round cylindrical morphologies of the synthesized microcrystals of Co-doped ZnO show an increase in absorption with the cobalt doping. The antibacterial activity of the as-obtained Co-doped ZnO-MCs was tested against the bacterial strains of gram-negative (Escherichia coli, Klebsiella pneumonia) and gram-positive bacteria (Staphylococcus aureus, Streptococcus pyogenes) via the agar well diffusion method. The zones of inhibition (ZOI) for Co-doped ZnO-MCs against E. coli and K. pneumoniae were found to be 17 and 19 mm, and 15 and 16 mm against S. Aureus and S. pyogenes, respectively. The prepared Co-doped ZnO-MCs were thus established as a probable antibacterial agent against gram-negative bacterial strains.
Study on the Adsorption Properties of Graphene Oxide/Laponite RD/Chitosan Composites
Authors: Du Wenjie , Ma Rui , Liu Zhiyan , Yang Gang , Chen Tao
Published: June 2021

A novel Graphene oxide/Laponite RD/Chitosan ternary composite was synthesized by sol-gel method and freeze-drying method. The Laponite RD was silanized by 3-aminopropyltriethoxysilane (APTES). Graphene oxide (GO) was prepared by an improved Hummers method. Under the acidic conditions, self-assembly recombination was realized by electrostatic interaction between modified Laponite RD and GO. The results from Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy confirmed that the modified Laponite RD was successfully compounded with GO, and the composite is laminated and stacked. The results from BET (Brunauer–Emmett–Teller) methods found that the BET-specific surface area of the hybrid aerogel significantly increased with the increase of the doping content of the composite, and the specific surface area of the aerogel composite with 20% doping content reached 81 m2/g. The structure of aerogel is porous, and there are numerous holes in the interior, which is closely related to adsorption properties. Thermogravimetric analysis (TG) test was used to explore the change of thermal properties of hybrid aerogel materials, and it was found that the addition of composite increased the initial decomposition temperature and thermal stability of hybrid aerogel. Finally, the potential applications of aerogel were tested, such as methylene blue adsorption and CO2 adsorption.
Selected Methods and Applications of Anti-Friction and Anti-Wear Surface Texturing
Authors: Wos Slawomir , Koszela Waldemar , Pawlus Pawel
Published: June 2021

The constant development of environmental protection causes the necessity to increase the efficiency of machines. By increasing the efficiency of machines, energy losses can be limited, leading to lower energy consumption. Friction reduction leads to an increase in efficiency and a decrease in wear. In this paper, selected surface texturing methods, such as burnishing and abrasive jet machining, with their limitations are presented. Thanks to those processes, various surface textures can be obtained. Examples of applications of these methods for friction and wear reduction are shown.
Durability of Cement and Ash Mortars with Fluidized and Siliceous Fly Ashes Exposed to HCl Acid Environment over a Period of 2 Years
Authors: Janowska-Renkas Elżbieta , Kaliciak Agnieszka , Janus Grzegorz , Kowalska Jolanta
Published: June 2021

The paper presents results of research on the impact of fly ash from fluidized bed combustion (FBC) of lignite, used in quantities of 30 and 45% by mass, and the mixture of FBC and silicious fly ash in amount of 45% by mass, on properties of cement–ash mortars. Mortars were exposed to aggressive environment of 1, 3, and 5% HCl solutions for 2 years. Mortars containing 45% FBC exposed to 1% HCl solution (pH = 2) showed the highest durability from among other mortars. The growth of their strength observed after 90 days of testing in 1% HCl environment, as well as the lowest drop of strength after 730 days of exposure to this environment, resulted from the reduced amount of large pores from 20 to 200 nm in mortars containing fly ash, with simultaneous growth of smaller pores of <20 nm during testing. A beneficial effect has been demonstrated of FBC addition to cement on properties of cement–ash mortars exposed to the aggressive impact of the HCl. Mortars with FBC fly-ash content increased to 45% by mass showed higher strength values, smaller differences in linear and mass changes, and increased durability in an aggressive environment observed during 730 days of testing.
Highly Dissipative Materials for Damage Protection against Earthquake-Induced Structural Pounding
Authors: Stręk Anna M. , Lasowicz Natalia , Kwiecień Arkadiusz , Zając Bogusław , Jankowski Robert
Published: June 2021

It is a common situation that seismic excitations may lead to collisions between adjacent civil engineering structures. This phenomenon, called earthquake-induced structural pounding, may result in serious damage or even the total collapse of the colliding structures. Filling the gap between two buildings erected close to one another by using visco-elastic materials can be considered to be one of the most effective methods to avoid seismic pounding. In this paper, a new polymer–metal composite material made of polyurethane and closed-cell aluminum foam is proposed as a pounding energy absorber for protection against earthquake hazards. The composite was created in two versions, with and without an adhesive interface. A series of experiments which reflect the conditions of seismic collision were performed: quasi-static compression, dynamic uniaxial compression and low-cycle dynamic compression with 10 loops of unloading at 10% strain. The composite material’s behavior was observed and compared with respect to uniform material specimens: polymer and metal foam. The experimental results showed that the maximum energy absorption efficiency in the case of the new material with the bonding layer was improved by 34% and 49% in quasi-static and dynamic conditions, respectively, in comparison to a sole polymer bumper. Furthermore, the newly proposed composites dissipated from 35% to 44% of the energy absorbed in the cyclic procedure, whereas the polymer specimen dissipated 25%. The capacity of the maintenance of the dissipative properties throughout the complete low-cycle loading was also satisfactory: it achieved an additional 100% to 300% of the energy dissipated in the first loading–unloading loop.
Narrow Diameter Dental Implants as an Alternative Treatment for Atrophic Alveolar Ridges. Systematic Review and Meta-Analysis
Authors: González-Valls Georgina , Roca-Millan Elisabet , Céspedes-Sánchez Juan Manuel , González-Navarro Beatriz , Torrejon-Moya Aina , López-López José
Published: June 2021

To determine the marginal bone loss and the survival, success and failure rates of narrow dental implants, a systematic literature search was carried out in the MEDLINE (Pubmed), Cochrane, Scopus, and Scielo databases for articles published between 2010 and 2021. The exclusion criteria were: systematic reviews, case reports, expert opinions; animal studies; samples of less than 10 subjects; follow-up periods of less than 36 months; smokers of minimum 10 cigarettes/day; and articles about mini-implants for orthodontic anchorage. Meta-analyses were performed to assess marginal bone loss and implant survival, success, and failure rates. Fifteen studies were included: 7 clinical trials, 3 randomized clinical trials, 3 cohort studies, and 2 case series. The total number of subjects was 773, in whom 1245 implants were placed. The survival rate for the narrow diameter implants was 97%, the success rate 96.8%, and the failure rate 3%. Marginal bone loss was 0.821 mm. All these data were evaluated at 36 months. Based on the literature, it can be considered that there is sufficient evidence to consider small diameter implants a predictable treatment option. These show favorable survival and success rates and marginal bone loss. All of them are comparable to those of standard diameter dental implants.
Size Effect of a Piezoelectric Patch on a Rectangular Plate with the Neural Network Model
Authors: Min Hequn , Zhang Jie , Fan Mu
Published: June 2021

Artificial neural networks have been widely used in many studies, such as the prediction of the piezoelectric effect of the plate of engineering structures in vibration and noise reduction. In this paper, an artificial neural network (ANN) model was employed to explore the piezoelectric patch size and thickness’s effect on the first order natural frequency and displacement amplitude of a plate. With the finite element method (FEM), a rectangular plate actuated by a piezoelectric patch was analyzed with various patch sizes. The FEM data was later used to build an ANN model. The dynamic response of the plate was predicted by the ANN model and validated with FEM in terms of 1st order natural frequency and displacement amplitude. Results from case studies showed that with the input of patch length, width and thickness, ANN model can accurately predict both natural frequency and displacement amplitude. When the input of ANN model was simplified to patch size and thickness or the volume of the patch, the accuracy became worse and worse. The influence of the patch size and thickness on the first order natural frequency was coupled and the maximal and minimal values were predicted based on the ANN model.
Pollutants Sorbent Made of Cotton Fabric Modified with Chitosan-Glutaraldehyde and Zinc Oxide Particles
Authors: Toteva Vesislava , Staneva Desislava , Grabchev Ivo
Published: June 2021

The paper reports on the preparation of composite materials by modifying cotton fabric with a layer of crosslinked glutaraldehyde chitosan containing zinc oxide particles. The ability of chitosan to form complexes with zinc ions has been used to control the size, structure, and distribution of the particles on the fiber surface. The three different obtained materials have been characterized by optical and scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and fluorescent analysis. It has been found that the interaction of the ZnO particles with the functional groups of chitosan affects its swelling ability in water and thus determines its sorption properties. The capacity of the materials to wipe water-soluble (textile reactive dye) and water-insoluble (crude oil and oil products) contaminants has been compared. The effect that the amount of zinc oxide has on the ability of the materials to remove contaminants has also been studied. The possibility for adsorption–desorption of the crude oil and reuse of the sorbent material has been investigated as well.
Analysis of Network Reliability Characteristics and Importance of Components in a Communication Network
Authors: Bisht Soni , Kumar Akshay , Goyal Nupur , Ram Mangey , Klochkov Yury
Published: June 2021

Network reliability is one of the most important concepts in this modern era. Reliability characteristics, component significance measures, such as the Birnbaum importance measure, critical importance measure, the risk growth factor and average risk growth factor, and network reliability stability of the communication network system have been discussed in this paper to identify the critical components in the network, and also to quantify the impact of component failures. The study also proposes an efficient algorithm to compute the reliability indices of the network. The authors explore how the universal generating function can work to solve the problems related to the network using the exponentially distributed failure rate. To illustrate the proposed algorithm, a numerical example has been taken.
Using a Modified VIKOR Technique for Evaluating and Improving the National Healthcare System Quality
Authors: Huang Sun-Weng , Liou James J. H. , Chuang Hai-Hua , Tzeng Gwo-Hshiung
Published: June 2021

The effectiveness of the national/regional healthcare system is one of the keys to prevent the spread of COVID-19. In the face of this unknown pandemic, where the healthcare system should continue to be promoted and improved are crucial decision issues. In the past, most studies have used the subjective opinions of experts for analysis and decision-making processes when investigating complicated decision-making problems. However, such decision-making processes are easily influenced by experts’ preferences. Therefore, this research proposes a soft computing technology that integrates CRiteria Importance Through Intercriteria Correlation (CRITIC) with the modified VlseKriterijumska Optimizacija I Kompromisno Resenje in Serbian, meaning multicriteria optimization and compromise solution (modified VIKOR) technique to reduce the impact of expert preference. In order to cope with the fact that COVID-19 has spread globally and to discover problems quickly and effectively, this study uses the global health security (GHS) index as the evaluation framework and conducts overall discussions in 195 countries/regions around the world. It is verified that the technology of soft computing can be used for continuous promotion and improvement of the national/regional healthcare system. This technology facilitates decision makers to know the gap of performance between the current healthcare system and the aspiration level. Finally, based on these gaps, we provide management advice to help improve these systems.
Interval Ranges of Fuzzy Sets Induced by Arithmetic Operations Using Gradual Numbers
Authors: Mao Qingsong , Huang Huan
Published: June 2021

Wu introduced the interval range of fuzzy sets. Based on this, he defined a kind of arithmetic of fuzzy sets using a gradual number and gradual sets. From the point of view of soft computing, this definition provides a new way of handling the arithmetic operations of fuzzy sets. The interval range is an important characterization of a fuzzy set. The interval range is also useful for analyses and applications of arithmetic. In this paper, we present general conclusions on crucial problems related to interval ranges of fuzzy sets induced by this arithmetic. These conclusions indicate that the corresponding conclusions in previous works should be modified: firstly, we give properties of the arithmetic and the composites of finite arithmetic. Then, we discuss the relationship between the domain of a gradual set and the range of its induced fuzzy set, and the relationship between the domain of a gradual set and the interval range of its induced fuzzy set. Based on the above results, we present the relationship between the intersection of the interval ranges of a group of fuzzy sets and the interval ranges of their resulting fuzzy sets obtained by compositions of finite arithmetic. Furthermore, we construct examples to show that even under conditions stronger than in previous work, there are still various possibilities in the relationship between the intersection of interval ranges of a group of fuzzy sets and the ranges of their resulted fuzzy sets, and there are still various possibilities in the relationship between the intersection of the interval ranges of a group of fuzzy sets and the interval ranges of their resulting fuzzy sets.
Design Optimization of a Traction Synchronous Homopolar Motor
Authors: Dmitrievskii Vladimir , Prakht Vladimir , Anuchin Alecksey , Kazakbaev Vadim
Published: June 2021

Synchronous homopolar motors (SHMs) have been attracting the attention of researchers for many decades. They are used in a variety of equipment such as aircraft and train generators, welding inverters, and as traction motors. Various mathematical models of SHMs have been proposed to deal with their complicated magnetic circuit. However, mathematical techniques for optimizing SHMs have not yet been proposed. This paper discusses various aspects of the optimal design of traction SHMs, applying the one-criterion unconstrained Nelder–Mead method. The considered motor is intended for use in a mining dump truck with a carrying capacity of 90 tons. The objective function for the SHM optimization was designed to reduce/improve the following main characteristics: total motor power loss, maximum winding current, and torque ripple. One of the difficulties in optimizing SHMs is the three-dimensional structure of their magnetic core, which usually requires the use of a three-dimensional finite element model. However, in this study, an original two-dimensional finite element model of a SHM was used; it allowed the drastic reduction in the computational burden, enabling objective optimization. As a result of optimization, the total losses in the motor decreased by up to 1.16 times and the torque ripple decreased by up to 1.34 times; the maximum armature winding current in the motor mode decreased by 8%.
Discovery Model Based on Analogies for Teaching Computer Programming
Authors: Jiménez Toledo Javier Alejandro , Collazos César A. , Ortega Manuel
Published: June 2021

Teaching the fundamentals of computer programming in a first course (CS1) is a complex activity for the professor and is also a challenge for them. Nowadays, there are several teaching strategies for dealing with a CS1 at the university, one of which is the use of analogies to support the abstraction process that a student needs to carry for the appropriation of fundamental concepts. This article presents the results of applying a discovery model that allowed for the extraction of patterns, linguistic analysis, textual analytics, and linked data when using analogies for teaching the fundamental concepts of programming by professors in a CS1 in university programs that train software developers. For that reason, a discovery model based on machine learning and text mining was proposed using natural language processing techniques for semantic vector space modeling, distributional semantics, and the generation of synthetic data. The discovery process was carried out using nine supervised learning methods, three unsupervised learning methods, and one semi-supervised learning method involving linguistic analysis techniques, text analytics, and linked data. The main findings showed that professors include keywords, which are part of the technical computer terminology, in the form of verbs in the statement of the analogy and combine them in quantitative contexts with neutral or positive phrases, where numerical examples, cooking recipes, and games were the most used categories. Finally, a structure is proposed for the construction of analogies to teach programming concepts and this was validated by the professors and students.