bluuebunny/crossref_metadata_2025 huggingface dataset:
Disruption of the Chitin Biosynthetic Pathway Results in Significant Changes in the Cell Growth Phenotypes and Biosynthesis of Secondary Metabolites of Monascus purpureus
Authors: Shu Meng , Lu Pengxin , Liu Shuai , Zhang Song , Gong Zihan , Cai Xinru , Zhou Bo , Lin Qinlu , Liu Jun
Published: August 2022

In this study, the gene monascus-5162 from Monascus purpureus LQ-6, identified as chitin synthase gene VI (chs6), was knocked out to disrupt the chitin biosynthetic pathway and regulate the biosynthesis of Monascus pigments (MPs) and citrinin. The results showed that the aerial hyphae on a solid medium were short and sparse after the deletion of chs6 in M. purpureus LQ-6, significantly reducing the germination percentage of active spores to approximately 22%, but the colony diameter was almost unaffected. Additionally, the deletion of chs6 changed the mycelial morphology of M. purpureus LQ-6 during submerged fermentation and increased its sensitivity to environmental factors. MP and citrinin biosynthesis was dramatically inhibited in the recombinant strain. Furthermore, comparative transcriptome analysis revealed that the pathways related to spore development and growth, including the MAPK signaling pathway, chitin biosynthetic pathway, and regulatory factors LaeA and WetA genes, were significantly downregulated in the early phase of fermentation. The mRNA expression levels of genes in the cluster of secondary metabolites were significantly downregulated, especially those related to citrinin biosynthesis. This is the first detailed study to reveal that chs6 plays a vital role in regulating the cell growth and secondary metabolism of the Monascus genus.
Reinforcing Health Data Sharing through Data Democratization
Authors: Wang Yuhang , Blobel Bernd , Yang Bian
Published: August 2022

In this paper, we propose a health data sharing infrastructure which aims to empower a democratic health data sharing ecosystem. Our project, named Health Democratization (HD), aims at enabling seamless mobility of health data across trust boundaries through addressing structural and functional challenges of its underlying infrastructure with the core concept of data democratization. A programmatic design of an HD platform was elaborated, followed by an introduction of one of our critical designs—a “reverse onus” mechanism that aims to incentivize creditable data accessing behaviors. This scheme shows a promising prospect of enabling a democratic health data-sharing platform.
Challenges in the Management of Post-COVID-19 Pulmonary Fibrosis for the Latin American Population
Authors: Cherrez-Ojeda Ivan , Cortés-Telles Arturo , Gochicoa-Rangel Laura , Camacho-Leon Génesis , Mautong Hans , Robles-Velasco Karla , Faytong-Haro Marco
Published: August 2022

This commentary aims to highlight some of the major issues (with possible solutions) that the Latin American region is currently dealing with in managing post-COVID-19 pulmonary fibrosis. Overall, there is little evidence for successful long-term COVID-19 follow-up treatment. The lack of knowledge regarding proper treatment is exacerbated in Latin America by a general lack of resources devoted to healthcare, and a lack of availability and access to multidisciplinary teams. The discussion suggests that better infrastructure (primarily multicenter cohorts of COVID-19 survivors) and well-designed studies are required to develop scientific knowledge to improve treatment for the increasing prevalence of pulmonary fibrosis in Latin America.
Assessing the Decision Usefulness of Integrated Reports of Namibian Listed Companies
Authors: Kamotho Daniel W. , Moloi Tankiso S. , Halleen Simone
Published: August 2022

The study evaluates the decision usefulness of integrated reports by listed Namibian companies using specially designed control checklists. A manual content analysis of the sampled 2018–2019 integrated reports was performed, using the control checklists for the decision usefulness’ qualitative characteristics. The study finds that the integrated reports produced in Namibia are generally decision useful, though the reports’ usefulness varies from company and industry. The study’s findings have policy implications, such as the need to prepare integrated reports for decision-making. The findings also provide detailed insights into the decision usefulness and quality of the Namibian listed companies’ integrated reports and can serve as feedback for companies, especially the report preparers. This study has ramifications for company leadership (e.g., financial managers, boards) and regulators, as it urges businesses to produce decision-useful annual integrated reports if they want their transparency disclosures to be viewed as “informative” by their significant stakeholders, thus improving the decision usefulness of their corporate reports.
Impact of the COVID-19 Pandemic on EU Convergence
Authors: Abrhám Josef , Vošta Milan
Published: August 2022

The effects of the COVID-19 pandemic were global and led to an economic decline in most countries of the EU. The development and values of economic indicators varied from country to country and showed significant regional differences. The study evaluates the coverage of selected economic indicators in the Member States of the EU in the period 2010–2020. The analytical part is based on empirical statistical data. As a methodological procedure for testing the convergence of the EU, we compared the results of the coefficient of variation of GDP per capita in PPP and the unemployment rate. The findings of this study confirm the predicted development trends. The pandemic has reversed major convergence trends. Divergence within the EU was affected by a lower decline in GDP in the developed countries of the EU. The tendencies of social disparities in the unemployment rate were different from the development of the coefficient of variation of GDP per capita. The first year of the pandemic marked a decline in disparities between the countries of the EU. For future research, we recommend monitoring the development of convergence in the next pandemic period.
Does Fiscal Decentralization Affect Regional High-Quality Development by Changing Peoples’ Livelihood Expenditure Preferences: Provincial Evidence from China
Authors: Wang Dingqing , Zhang Enqi , Liao Hongwei
Published: August 2022

The reform of the fiscal and taxation system is important for building a sound livelihood protection system as well as resisting the impact of uncertain events and thus promoting the quality of regional development. We explore the strengths and limitations of China’s fiscal decentralization system from the perspective of peoples’ livelihood expenditures, and provide an empirical basis for institution building for countries to withstand the shocks of uncertain events and promote high-quality regional development, using each provincial-level region in China as the research object. We find that fiscal decentralization has an inverted U-shaped relationship with regional high-quality development, and the inverted U-shaped relationship of fiscal decentralization with regional quality development is significant in the innovation, greenness, and openness dimensions. It is further found that in the process of constructing regional high-quality development, fiscal decentralization will raise the preference for healthcare expenditures, improve the modern public health system, and indirectly promote regional high-quality development, while it will lower the preference for social security employment expenditure, neglect the basic resident social security employment problem, and slow down the process of high-quality development. This paper expands the research on the correlation between fiscal decentralization, livelihood expenditure preferences, and regional development quality, and provides an important theoretical and practical basis for the improvement of the fiscal system and the improvement of social welfare levels in the post-COVID-19 era.
A Corpus-Based Study on the Translation of English Ideophones in Italian Picture Books: The Case of the Diary of a Wimpy Kid
Authors: Pischedda Pier Simone
Published: August 2022

This paper aims to provide the readers with an overview of the nature of sound symbolism in Italian and offers new food for thought to scholars in the under-researched field of sound symbolism in translated literature for young readers. Whilst English uses ideophones in literature for young readers, Italian sound symbolism often seems to rely on Anglophonic creations, arguably due to both linguistic and cultural reasons. The third and fourth books of the series for children and young adults, ‘Diary of a Wimpy Kid’, have been taken as a source for examples. The books contain both text and pictures, which include ideophones in them. Each of the two English books has been analysed together with their Italian versions, and the strategies employed to translate sound symbolism have been catalogued into a small corpus. The results, on top of elucidating the nature of Italian sound symbolism, show a considerable degree of adaption and a frequent reliance on Anglophonic forms, with scattered attempts made at adapting English ideophones for the Italian readership. This is achieved through the modification of source forms to resemble Italian syntactical structures more closely and through the removal of certain consonant clusters that are considered typically Anglophonic (i.e., , ).
Acquisition of Chinese Verb Separation by Adult L2 Learners
Authors: Gao Zhe , Wiener Seth , MacWhinney Brian
Published: August 2022

Chinese verb separation is a grammatical construction in which a bimorphemic verb compound separates and expands into a verb phrase. For example, to say “sang one song”, one must insert the aspect marker le and classifier phrase yī shǒu between the verb chàng gē ‘sing-song’ as in chàng le yī shǒu gē (sing-LE-one-classifier-song). Adult second language (L2) learners face at least three problems related to acquiring verb separation: separation patterns are complex and numerous, classroom oral input is limited, and L1 transfer often fails. To better understand L2 learners’ acquisition of verb separation, this study tested 28 adult L2-Chinese classroom learners. Three tasks were administered online: verb decomposition, grammaticality judgment, and oral translation. On average, only 37% of verbs were accurately decomposed, 63% of verbs were accurately judged to be grammatical, and 19% of verbs were orally produced with the correct separation pattern. Chinese verb separation, particularly decomposition and oral production, is thus extremely challenging for L2 learners to acquire—even for advanced learners with a relatively large vocabulary size. The results are discussed in terms of the Unified Competition Model and L2 Chinese pedagogy.
Cerebral Venous Oxygen Saturation in Hypoperfusion Regions May Become a New Imaging Indicator to Predict the Clinical Outcome of Stroke
Authors: Cao Fengqiu , Wang Mingming , Fan Shengyu , Han Shanhua , Guo Yingwei , Zaman Asim , Guo Jia , Luo Yu , Kang Yan
Published: August 2022

To automatically and quantitatively evaluate the venous oxygen saturation (SvO2) in cerebral ischemic tissues and explore its value in predicting prognosis. A retrospective study was conducted on 48 AIS patients hospitalized in our hospital from 2015–2018. Based on quantitative susceptibility mapping and perfusion-weighted imaging, this paper measured the cerebral SvO2 in hypoperfusion tissues and its change after intraarterial rt-PA treatment. The cerebral SvO2 in different hypoperfusion regions between the favorable and unfavorable clinical outcome groups was analyzed using an independent t-test. Relationships between cerebral SvO2 and clinical scores were determined using the Pearson correlation coefficient. The receiver operating characteristic process was conducted to evaluate the accuracy of cerebral SvO2 in predicting unfavorable clinical outcomes. Cerebral SvO2 in hypoperfusion (Tmax > 4 and 6 s) was significantly different between the two groups at follow-up (p < 0.05). Cerebral SvO2 and its changes before and after treatment were negatively correlated with clinical scores. The positive predictive value, negative predictive value, accuracy, and area under the curve of the cerebral SvO2 were higher than those predicted by the ischemic core. Therefore, the cerebral SvO2 of hypoperfusion regions was a stronger imaging predictor of unfavorable clinical outcomes after stroke.
Effectiveness of the Inactivated SARS-CoV-2 (Vero Cell) Vaccine in Peruvian Health Workers
Authors: Solis-Castro Maria Edith , Jaramillo-Corrales Alex , Gonzalez Seminario Rommell Veintimilla , Janampa Grados Noemi , Mamani Pilco Idania Edith , Vargas Quispe Karina Elizabeth , La Torre Rosillo Lenin Yonel , Vásquez Dominguez Mario Neyser , Enriquez Cusi David Teodoro , Minaya Percy , Pardo Ruiz Karim Jacqueline , Díaz-Vélez Cristian , Pachas Vannesa A. , Alberca Ricardo Wesley , Pachas Paul E.
Published: August 2022

Introduction: The COVID-19 pandemic has caused a global health crisis. Vaccines against this disease have demonstrated variable efficacy and safety, although effectiveness has not been evaluated. In February 2021, the Ministry of Health of Peru approved the emergency use of the inactivated SARS-CoV-2 (Vero Cell) vaccine and initiated vaccination with health personnel at the national level. The objective of the study is to determine the effectiveness of this vaccine to reduce infections, hospitalizations, and deaths due to COVID-19. Methodology: We performed a retrospective cohort study in the period from 23 February to 26 June 2021; data were obtained from the Ministry of Health (including demographic, epidemiologic, clinical, hospital, laboratory results, deaths, and both date and quantity of vaccine doses delivered). The exposed cohort were those who received one or two vaccine doses and the non-exposed were unvaccinated. The events studied were infections, hospitalizations and deaths in the cohorts. We consider a case confirmed for COVID-19 if the test result was positive for SARS-CoV-2, via PCR or antigen test. Effectiveness was measured with incidence density ratio and risk. Confounding factors were controlled using a Poisson model with robust variance. Results: We enlisted 520,733 health workers, of whom 415,212 had two vaccine doses and 105,521 were unvaccinated. The median age was 40 years (IQR: 32–50), and 65.6% were female. The effectiveness of two vaccine doses fourteen days after application adjusted by age, sex, hospitalization, and antecedent of having the infection was 90.9% (95% CI: 85.5–94.2%); effectiveness to avoid death from COVID-19; 67.7% (60.1–73.8%) effectiveness to avoid hospitalizations; and 26.3% (23.8–28.6%) effectiveness to reduce the risk of infection by SARS-CoV-2 relative to the unvaccinated cohort. Conclusions: The inactivated SARS-CoV-2 (Vero Cell) vaccine used in two doses has an acceptable effectiveness against death and risk of hospitalization, whereas it has less effectiveness in preventing COVID-19 infection.
Roles of microRNAs in Regulating Apoptosis in the Pathogenesis of Endometriosis
Authors: Azam Izyan Nabila Ahmad , Wahab Norhazlina Abdul , Mokhtar Mohd Helmy , Shafiee Mohamad Nasir , Mokhtar Norfilza Mohd
Published: August 2022

Endometriosis is a gynecologic disorder characterized by the presence of endometrial tissues outside the uterine cavity affecting reproductive-aged women. Previous studies have shown that microRNAs and their target mRNAs are expressed differently in endometriosis, suggesting that this molecule may play a role in the development and persistence of endometriotic lesions. microRNA (miRNA), a small non-coding RNA fragment, regulates cellular functions such as cell proliferation, differentiation, and apoptosis by the post-transcriptional modulation of gene expression. In this review, we focused on the dysregulated miRNAs in women with endometriosis and their roles in the regulation of apoptosis. The dysregulated miRNAs and their target genes in this pathophysiology were highlighted. Circulating miRNAs as potential biomarkers for the diagnosis of endometriosis have also been identified. As shown by various studies, miRNAs were reported to be a potent regulator of gene expression in endometriosis; thus, identifying the dysregulated miRNAs and their target genes could help discover new therapeutic targets for treating this disease. The goal of this review is to draw attention to the functions that miRNAs play in the pathophysiology of endometriosis, particularly those that govern cell death.
IL-18 Signaling Is Essential for Causing Streptococcal Toxic Shock-like Syndrome (STSLS)
Authors: Xu Lei , Zeng Yue , Gao Peiying , Lu Xi , Xia Kunlong , Zhou Liting , Zhang Chengfeng , Yi Chenyang , Zhang Anding
Published: August 2022

Streptococcus suis (S. suis) is an emerging zoonotic pathogen that can cause multiple diseases, including streptococcal toxic shock-like syndrome (STSLS). The S. suis SC-19 strain could cause NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome hyperactivation, then induce a cytokine storm and STSLS. Although IL-18 is the downstream effector of NLRP3 signaling, the role of IL-18 signaling on STSLS remains to be elucidated. Thus, il18r1 gene knockout mice were constructed and challenged with the SC-19 strain. Alleviated clinical signs and tissue damages, as well as improved survival were observed in il18r−/− mice compared with the WT mice post-SC-19 challenge. Meanwhile, an obvious decrease in the inflammatory cytokine levels in blood was observed in the il18r-/- mice infected with SC-19. Therefore, IL-18, the downstream effector of NLRP3 inflammasome activation, was responsible for the cytokine storm and STSLS development caused by S. suis, suggesting that IL-18/IL-18Rα signaling could serve as a new target for STSLS.
Tribute to Kenneth J. Breslauer
Authors: Chalikian Tigran V.
Published: August 2022

It is an exciting experience to serve as guest editor for a Special Issue celebrating the 75th birthday of Professor Kenneth J [...]
Some Factors from Theory, Simulation, Experiment and Proteomes in the Current Biosphere Supporting Deep Oceans as the Location of the Origin of Terrestrial Life
Authors: Halley J. W.
Published: August 2022

Some standard arguments are reviewed supporting deep ocean trenches as a likely location for the origin of terrestrial life. An analysis of proteomes of contemporary prokaryotes carried out by this group is cited as supporting evidence, indicating that the original proteins were formed by quenching from temperatures close to the boiling point of water. Coarse-grained simulations of the network formation process which agree quite well with experiments of such quenches both in drying and rapid fluid emission from a hot to a cold fluid are also described and cited as support for such a scenario. We suggest further experiments, observations and theoretical and simulation work to explore this hypothesis.
P16INK4A—More Than a Senescence Marker
Authors: Safwan-Zaiter Hasan , Wagner Nicole , Wagner Kay-Dietrich
Published: August 2022

Aging is a biological feature that is characterized by gradual degeneration of function in cells, tissues, organs, or an intact organism due to the accumulation of environmental factors and stresses with time. Several factors have been attributed to aging such as oxidative stress and augmented production or exposure to reactive oxygen species, inflammatory cytokines production, telomere shortening, DNA damage, and, importantly, the deposit of senescent cells. These are irreversibly mitotically inactive, yet metabolically active cells. The reason underlying their senescence lies within the extrinsic and the intrinsic arms. The extrinsic arm is mainly characterized by the expression and the secretory profile known as the senescence-associated secretory phenotype (SASP). The intrinsic arm results from the impact of several genes meant to regulate the cell cycle, such as tumor suppressor genes. P16INK4A is a tumor suppressor and cell cycle regulator that has been linked to aging and senescence. Extensive research has revealed that p16 expression is significantly increased in senescent cells, as well as during natural aging or age-related pathologies. Based on this fact, p16 is considered as a specific biomarker for detecting senescent cells and aging. Other studies have found that p16 is not only a senescence marker, but also a protein with many functions outside of senescence and aging. In this paper, we discuss and shed light on several studies that show the different functions of p16 and provide insights in its role in several biological processes besides senescence and aging.
Molecular Cloning and Functional Analysis of IrUGT86A1-like Gene in Medicinal Plant Isodon rubescens (Hemsl.) Hara
Authors: Lian Conglong , Lan Jinxu , Zhang Bao , Yang Hao , Guo Kaihua , Li Jingjing , Chen Suiqing
Published: August 2022

The synthesis of secondary metabolites in plants often includes glycosylation modifications. Often, the final step of constructing plant secondary metabolites is completed by glycosylation transferases, which are also involved in many cell processes. In this study, a UDP-glycosyltransferase gene (UGT) was amplified from Isodon rubescens (Hemsl.) Hara with RT-PCR and named IrUGT86A1-like (GenBank: MZ913258). Here, we found that IrUGT86A1-like gene is 1450 bp in length and encodes for 479 amino acids. Bioinformatics analysis revealed that IrUGT86A1-like is a stable and hydrophilic protein, located in the cytoplasm with a transmembrane domain. Phylogenetic analysis showed that IrUGT86A1-like protein has the closest genetic relationship with the UDP-glycosyltransferase 86A1-like protein (XP_042054241.1) of Salvia splendens. RT-qPCR analysis demonstrated that the expression of IrUGT86A1-like gene varied in different tissues; leaves had the highest expression followed by flowers, stems, and roots had the lowest expression. This expression trend is similar to the distribution of oridonin content in different tissues of I. rubescens. Additionally, IrUGT86A1-like gene was found to be positively enhanced by NaCl and MeJA treatment, and in contrast was down-regulated by ABA treatment. Finally, the prokaryotic expression vector pEASY®-Blunt E1-IrUGT86A1 was successfully used to express about 53 KD of IrUGT86A1-like protein. This research builds a foundation for further investigation on the function of this gene in the synthesis and modification of secondary metabolites.
C3a and C5b-9 Differentially Predict COVID-19 Progression and Outcome
Authors: Detsika Maria G. , Diamanti Elpida , Ampelakiotou Kleio , Jahaj Edison , Tsipilis Stamatis , Athanasiou Nikolaos , Dimopoulou Ioanna , Orfanos Stylianos E. , Tsirogianni Alexandra , Kotanidou Anastasia
Published: August 2022

SARS-CoV-2 infection may result in severe pneumonia leading to mechanical ventilation and intensive care (ICU) treatment. Complement activation was verified in COVID-19 and implicated as a contributor to COVID-19 pathogenesis. This study assessed the predictive potential of complement factors C3a and C5b-9 for COVID-19 progression and outcome. We grouped 80 COVID-19 patients into severe COVID-19 patients (n = 38) and critically ill (n = 42) and subdivided into non-intubated (n = 48) and intubated (n = 32), survivors (n = 57) and non-survivors (n = 23). Results: A significant increase for C3a and C5b-9 levels was observed between: severely and critically ill patients (p < 0.001 and p < 0.0001), non-intubated vs intubated (p < 0.001 and p < 0.05), survivors vs non-survivors (p < 0.001 and p < 0.01). ROC analysis for the need for ICU treatment revealed a higher AUC for C5b-9 (0.764, p < 0.001) compared to C3a (AUC = 0.739, p < 0.01). A higher AUC was observed for C3a for the need for intubation (AUC = 0.722, p < 0.001) or mortality (AUC = 0.740, p < 0.0001) compared to C5b-9 (need for intubation AUC = 0.656, p < 0.05 and mortality AUC = 0.631, p = NS). Combining the two markers revealed a powerful prediction tool for ICU admission (AUC = 0.773, p < 0.0001), intubation (AUC = 0.756, p < 0.0001) and mortality (AUC = 0.753, p < 0.001). C3a and C5b-9 may be considered as prognostic tools separately or in combination for the progression and outcome of COVID-19.
Transcriptome Analysis Provides Insights into Potentilla bifurca Adaptation to High Altitude
Authors: Tang Xun , Li Jinping , Liu Likuan , Jing Hui , Zuo Wenming , Zeng Yang
Published: August 2022

Potentilla bifurca is widely distributed in Eurasia, including the Tibetan Plateau. It is a valuable medicinal plant in the Tibetan traditional medicine system, especially for the treatment of diabetes. This study investigated the functional gene profile of Potentilla bifurca at different altitudes by RNA-sequencing technology, including de novo assembly of 222,619 unigenes from 405 million clean reads, 57.64% of which were annotated in Nr, GO, KEGG, Pfam, and Swiss-Prot databases. The most significantly differentially expressed top 50 genes in the high-altitude samples were derived from plants that responded to abiotic stress, such as peroxidase, superoxide dismutase protein, and the ubiquitin-conjugating enzyme. Pathway analysis revealed that a large number of DEGs encode key enzymes involved in secondary metabolites, including phenylpropane and flavonoids. In addition, a total of 298 potential genomic SSRs were identified in this study, which provides information on the development of functional molecular markers for genetic diversity assessment. In conclusion, this study provides the first comprehensive assessment of the Potentilla bifurca transcriptome. This provides new insights into coping mechanisms for non-model organisms surviving in harsh environments at high altitudes, as well as molecular evidence for the selection of superior medicinal plants.
The Barrier’s Heights and Its Inhomogeneities on Diamond Silicon Interfaces
Authors: Łoś Szymon , Fabisiak Kazimierz , Paprocki Kazimierz , Kozera Wojciech , Knapowski Tomasz , Szybowicz Mirosław , Dychalska Anna
Published: August 2022

In this work, the electrical parameters of the polycrystalline diamonds’ p-PCD/n-Si heterojunction were investigated using temperature-dependent current–voltage (I-V) characteristics. In the temperature range of 80–280 K, the ideality factor (n) and energy barrier height (φb) were found to be strongly temperature dependent. The φb increases with temperature rise, while the n value decreases. The observed dependencies are due to imperfections at the interface region of a heterojunction and the non-homogeneous distribution of the potential barrier heights. Values of the φb were calculated from I-V characteristics using the thermionic emission theory (TE). The plot of φb versus 1/2 kT revealed two distinct linear regions with different slopes in temperature regions of 80–170 K and 170–280 K. This indicates the existence of a double Gaussian distribution (DGD) in heterojunctions. Parameters such as mean barrier heights φ¯b and standard deviations σ were obtained from the plots linearization and read out from intercepts and slopes. They take values φ¯b = 1.06 eV, σ = 0.43 eV, respectively. The modified Richardson plot is drawn to show the linear behavior in these two temperature ranges, disclosing different values of the effective Richardson constants (A*).
Stability of Strained Stanene Compared to That of Graphene
Authors: Kosarev Igor V. , Dmitriev Sergey V. , Semenov Alexander S. , Korznikova Elena A.
Published: August 2022

Stanene, composed of tin atoms, is a member of 2D-Xenes, two-dimensional single element materials. The properties of the stanene can be changed and improved by applying deformation, and it is important to know the range of in-plane deformation that the stanene can withstand. Using the Tersoff interatomic potential for calculation of phonon frequencies, the range of stability of planar stanene under uniform in-plane deformation is analyzed and compared with the known data for graphene. Unlike atomically flat graphene, stanene has a certain thickness (buckling height). It is shown that as the tensile strain increases, the thickness of the buckled stanene decreases, and when a certain tensile strain is reached, the stanene becomes absolutely flat, like graphene. Postcritical behaviour of stanene depends on the type of applied strain: critical tensile strain leads to breaking of interatomic bonds and critical in-plane compressive strain leads to rippling of stanene. It is demonstrated that application of shear strain reduces the range of stability of stanene. The existence of two energetically equivalent states of stanene is shown, and consequently, the possibility of the formation of domains separated by domain walls in the stanene is predicted.
Corrosion-Fatigue Life Prediction of the U-Shaped Beam in Urban Rail Transit under a Chloride Attack Environment
Authors: Chen Guixiang , Wang Mingjie , Cui Chenxing , Zhang Qingzhang
Published: August 2022

The coupled effect of the chloride attack environment and train load seriously affects the safety and durability of urban rail transit viaducts and dramatically reduces their service life. In this research, a corrosion-fatigue life prediction model of the prestressed concrete (PC) beam under the coupled effect of the chloride attack environment and train load was developed. This proposed model was illustrated by a 30 m-span PC U-shaped beam in an urban rail transit viaduct. The competitive relationship between concrete fatigue cracking time, non-prestressed reinforcement corrosion initiation time, and concrete corrosion-induced cracking time was discussed. The effects of train frequency, the chloride attack environment grade, and the environmental temperature and relative humidity were investigated on corrosion-fatigue life. Results indicate that train frequency, the chloride attack environment grade, and the environmental temperature can reduce the corrosion-fatigue life of a U-shaped beam by up to 30.0%, 50.7%, and 21.5%, respectively. A coupled chloride attack environment and train frequency can reduce the corrosion-fatigue life by up to 61.2%. Distinct from the environmental temperature, the change of relative humidity has little effect on the corrosion-fatigue life of the U-shaped beam.
Estimating Radiation Shielding of Fired Clay Bricks Using ANN and GEP Approaches
Authors: Amin Muhammad Nasir , Ahmad Izaz , Abbas Asim , Khan Kaffayatullah , Qadir Muhammad Ghulam , Iqbal Mudassir , Abu-Arab Abdullah Mohammad , Alabdullah Anas Abdulalim
Published: August 2022

This study aimed to determine how radiation attenuation would change when the thickness, density, and compressive strength of clay bricks, modified with partial replacement of clay by fly ash, iron slag, and wood ash. To conduct this investigation, four distinct types of bricks—normal, fly ash-, iron slag-, and wood ash-incorporated bricks were prepared by replacing clay content with their variable percentages. Additionally, models for predicting the radiation-shielding ability of bricks were created using gene expression programming (GEP) and artificial neural networks (ANN). The addition of iron slag improved the density and compressive strength of bricks, thus increasing shielding capability against gamma radiation. In contrast, fly ash and wood ash decreased the density and compressive strength of burnt clay bricks, leading to low radiation shielding capability. Concerning the performance of the Artificial Intelligence models, the root mean square error (RMSE) was determined as 0.1166 and 0.1876 nC for the training and validation data of ANN, respectively. The training set values for the GEP model manifested an RMSE equal to 0.2949 nC, whereas the validation data produced RMSE = 0.3507 nC. According to the statistical analysis, the generated models showed strong concordance between experimental and projected findings. The ANN model, in contrast, outperformed the GEP model in terms of accuracy, producing the lowest values of RMSE. Moreover, the variables contributing towards shielding characteristics of bricks were studied using parametric and sensitivity analyses, which showed that the thickness and density of bricks are the most influential parameters. In addition, the mathematical equation generated from the GEP model denotes its significance such that it can be used to estimate the radiation shielding of burnt clay bricks in the future with ease.
Study on the Mechanical Properties and Durability of Recycled Aggregate Concrete under the Internal Curing Condition
Authors: Yang Guanghao , Li Qiuyi , Guo Yuanxin , Liu Haibao , Zheng Shidong , Chen Mingxu
Published: August 2022

Poor mechanical properties and durability of recycled aggregate concrete (RAC) hinder its application in the construction field. In this study, pre-wetted recycled coarse aggregate was used as the internal curing material for prepared RAC with low water-to-binder ratio (W/B), aiming to improve the mechanical properties and durability. The results show that the workability decreases with increasing contents of pre-wetted recycled coarse aggregate. The variation in compressive strength of RAC with different contents of pre-wetted recycled coarse aggregate is obvious within 28 d. After 28 d, the effect of internal curing of pre-wetted recycled coarse aggregate starts to occur, causing a sustained increase in compressive strength. The sealed concrete with 50% and 75% pre-wetted recycled coarse aggregate contents presents the highest compressive strength and better internal curing effect. The pre-wetted recycled coarse aggregate decreases the relative humidity inside the concrete and effectively inhibits the development of shrinkage in the early stages. The RAC with pre-wetted recycled coarse aggregate presents little effect on the drying shrinkage. Additionally, the electric flux of RAC cured for 28 d increases from 561C to 1001C, which presents good resistance to chloride permeation. Microscopic tests indicate that the incorporation of pre-wetted recycled coarse aggregate is beneficial to the improvements of internal structure of RAC.
Effect of the Microsand Fraction on the Ballistic Resistance of UHP-SFRC
Authors: Kheml Přemysl , Carrera Kristýna , Horák Pavel
Published: August 2022

This work investigates the effect of various sand fractions on the ballistic resistance of ultra-high-performance steel-fibre-reinforced concrete (UHP-SFRC) samples. We specifically investigated replacing expensive and generally inaccessible microsands with commonly available sands. The tests and the measured values show that replacing part of the microsand with the more commonly and economically acceptable 0/2 mm aggregate fraction minimises the resulting mechanical properties and ballistic resistance. The most common type of ammunition was used to test all sample bodies, which is a 7.62 × 39 mm calibre with an all-metal jacket and a mild steel core. The damage’s extent and mode were determined using a 3D scanner operating on photogrammetry.
Development and Testing of Castables with Low Content of Calcium Oxide
Authors: Zemánek David , Nevřivová Lenka
Published: August 2022

Colloidal silica is used in many kinds of industry. It is an aqueous dispersion of SiO2 nanoparticles. SiO2 colloidal solutions are commercially available in different concentrations, with different particle sizes and are stabilized with different ions. Colloidal SiO2 was used in this study as a cement replacement in refractory castable. The present study, in its first stage, offers an assessment of five different SiO2 colloidal solutions. The particle size of the solutions was 15 nm, the particle concentration was 30% and 40% and the colloidal solutions were stabilized with Na+, OH− and Cl− ions. The effect of the colloidal solutions on selected characteristics of the refractory pastes and on their mineralogical composition after firing at 1000 °C and 1500 °C was described. The most suitable SiO2 colloidal solution from the first stage was subsequently used for the refractory castable test samples’ preparation in the second stage. Refractory castables, unlike paste, contain a coarse aggregate (grog) up to a grain size of 6 mm. Four types of coarse refractory grog were evaluated. Their effect on selected characteristics of the refractory castable and on its mineralogical composition after firing at 1000 °C and 1500 °C was described. The selected characteristics, within the scope of this study, include bulk density, apparent porosity, cold modulus of rupture and linear changes after firing. Finally, the study describes the effect of the sol particle concentration and the effect of pore size distribution on corrosion resistance and on the internal structure of the material. Mineral and chemical compositions and microstructures of both the raw materials and designed aggregates were thoroughly investigated by the means of X-ray fluorescence spectroscopy, powder X-ray diffraction and scanning electron microscopy. An analysis of the transition zone between corrosive media (K2CO3) and tested castables showed better corrosion resistance for a sol-gel castable than an ultra-low cement castable.
pH-Sensitive Polyacrylic Acid-Gated Mesoporous Silica Nanocarrier Incorporated with Calcium Ions for Controlled Drug Release
Authors: Kong Jungwon , Park Sung Soo , Ha Chang-Sik
Published: August 2022

In this work, polyacrylic acid-functionalized MCM-41 was synthesized, which was made to interact with calcium ions, in order to realize enhanced pH-responsive nanocarriers for sustained drug release. First, mesoporous silica nanoparticles (MSNs) were prepared by the sol-gel method. Afterward, a (3-trimethoxysilyl)propyl methacrylate (TMSPM) modified surface was prepared by using the post-grafting method, and then the polymerization of the acrylic acid was performed. After adding a calcium chloride solution, polyacrylic acid-functionalized MSNs with calcium-carboxyl ionic bonds in the polymeric layer, which can prevent the cargo from leaking out of the mesopore, were prepared. The structure and morphology of the modified nanoparticles (PAA-MSNs) were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and N2 adsorption–desorption analysis, etc. The controlled release of guest molecules was studied by using 5-fluorouracil (5-FU). The drug molecule-incorporated nanoparticles showed different releasing rates under different pH conditions. It is considered that our current materials have the potential as pH-responsive nanocarriers in the field of medical treatment.
A Dual-Input Neural Network for Online State-of-Charge Estimation of the Lithium-Ion Battery throughout Its Lifetime
Authors: Qian Cheng , Xu Binghui , Xia Quan , Ren Yi , Yang Dezhen , Wang Zili
Published: August 2022

Online state-of-charge (SOC) estimation for lithium-ion batteries is one of the most important tasks of the battery management system in ensuring its operation safety and reliability. Due to the advantages of learning the long-term dependencies in between the sequential data, recurrent neural networks (RNNs) have been developed and have shown their superiority over SOC estimation. However, only time-series measurements (e.g., voltage and current) are taken as inputs in these RNNs. Considering that the mapping relationship between the SOC and the time-series measurements evolves along with the battery degradation, there still remains a challenge for RNNs to estimate the SOC accurately throughout the battery’s lifetime. In this paper, a dual-input neural network combining gated recurring unit (GRU) layers and fully connected layers (acronymized as a DIGF network) is developed to overcome the above-mentioned challenge. Its most important characteristic is the adoption of the state of health (SOH) of the battery as the network input, in addition to time-series measurements. According to the experimental data from a batch of LiCoO2 batteries, it is validated that the proposed DIGF network is capable of providing more accurate SOC estimations throughout the battery’s lifetime compared to the existing RNN counterparts. Moreover, it also shows greater robustness against different initial SOCs, making it more applicable for online SOC estimations in practical situations. Based on these verification results, it is concluded that the proposed DIGF network is feasible for estimating the battery’s SOC accurately throughout the battery’s lifetime against varying initial SOCs.
Ball Bearing Fault Diagnosis Using Recurrence Analysis
Authors: Kecik Krzysztof , Smagala Arkadiusz , Lyubitska Kateryna
Published: August 2022

This paper presents the problem of rolling bearing fault diagnosis based on vibration velocity signal. For this purpose, recurrence plots and quantification methods are used for nonlinear signals. First, faults in the form of a small scratch are intentionally introduced by the electron-discharge machining method in the outer and inner rings of a bearing and a rolling ball. Then, the rolling bearings are tested on the special laboratory system, and acceleration signals are measured. Detailed time-dependent recurrence methodology shows some interesting results, and several of the recurrence indicators such as determinism, entropy, laminarity, trapping time and averaged diagonal line can be utilized for fault detection.
Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash
Authors: Wang Qing , Huang Wenjie , Liang Yuhang , Li Congbo , Lai Mianheng , Sun Jing
Published: August 2022

Magnesium oxychloride cement (MOC), a type of special construction material, has drawn much research attention in solid waste utilization and environmental protection due to its eco-friendly production. Ammonia soda residue (ASR), a by-product generated from sodium carbonate manufacturing, is one of the industrial wastes that can be recycled in MOC systems. However, ASR exhibits adverse effects on the fresh performance and volume stability of MOC pastes. This paper aims at improving the properties of ASR-MOC by introducing fly ash (FA), solid waste from the power industry. Firstly, the roles of FA in MOC pastes are evaluated and analyzed. Then, three substitution ratios of FA (33.3%, 50% and 66.7% in weight) for ASR are designed for MOC pastes with 10% to 40% industrial wastes. Flowability, setting, strength and expansion of all mixtures were experimentally studied. Furthermore, X-ray diffraction (XRD) and scanning electron microscope (SEM) approaches were adopted to illustrate the microstructure changes. Results show that by adding different amounts of FA, the inferior flowability of MOC caused by ASR can be improved by 6–23%, the setting process can be prolonged by 30–55% and the expansion ratio can be reduced by 14–66%. The intensity of characteristic peaks of 5-phase and Mg(OH)2, together with the degrees of crystallization in XRD curves, well explain the strength variation and volume stability of ASR-MOC pastes. According to the regulation of relative specification, up to 20% of solid wastes in weight (10% FA + 10% ASR) can be consumed, contributing greatly to the greener sustainable development of construction materials.
Effect of Welding Parameters on Mechanical Properties and Microstructure of Friction Stir Welded AA7075-T651 Aluminum Alloy Butt Joints
Authors: Kosturek Robert , Torzewski Janusz , Wachowski Marcin , Śnieżek Lucjan
Published: August 2022

The aim of this study was to examine the mechanical properties of 5-mm-thick AA7075-T651 alloy using three different welding velocities, 50, 75 and 100 mm/min, and four various sets of tool rotation speeds: 400, 600, 800 and 1000 rpm. All obtained joints were defect-free. In all cases, the values of UTS exceeded 400 MPa, corresponding to 68.5% minimum joint efficiency. The highest value of 447.7 MPa (76.7% joint efficiency) was reported for the joint produced via 400 rpm tool rotation speed and 100 mm/min welding velocity. The SZ microstructure of the strongest joint was characterized by a 5.2 ± 1.7 μm grain size and microhardness of approximately 145 HV0.1. The TMAZ/HAZ interface was identified as the low-hardness zone (105–115 HV0.1, depending on parameters), where the failure of the tensile samples takes place. The fracture mechanism is dominated by a transgranular ductile rupture with microvoid coalescence.
A Simple Method for Preparation of Highly Conductive Nitrogen/Phosphorus-Doped Carbon Nanofiber Films
Authors: Chen Tongzhou , Chi Yongbo , Liu Xingyao , Xia Xiwen , Chen Yousi , Xu Jian , Song Yujie
Published: August 2022

Heteroatom-doped conductive carbon nanomaterials are promising for energy and catalysis applications, but there are few reports on increasing their heteroatom doping content and conductivity simultaneously. In this manuscript, we use 2-(4-aminophenyl)-5-aminobenzimidazole as the diamine monomer to prepare polyamic acid with asymmetric structural units doped with phosphoric acid (PA) and polyacrylonitrile (PAN) as innovative composite precursors, which are then electrospun into nanofiber films. After stabilization and carbonization, the electrospun fibers are converted into N/P co-doped electrospun carbon nanofiber films (ECNFs) with high heteroatom content, including 4.33% N and 0.98% P. The morphology, structure, and conductivity of ECNFs were systematically characterized. The ECNFs doped with 15 wt.% PA exhibited conductivity that was 47.3% higher than that of the ECNFs undoped with PA, but the BET surface area decreased by 23%. The doped PA in the precursor nanofibers participated in the cyclization of PAN during thermal stabilization, as indicated by infrared spectroscopy and thermogravimetric analysis results. X-ray diffraction and Raman results indicate that a moderate amount of PA doping facilitated the formation of ordered graphitic crystallite structures during carbonization and improved the conductivity of ECNFs.
Ti64/20Ag Porous Composites Fabricated by Powder Metallurgy for Biomedical Applications
Authors: Olmos Luis , Gonzaléz-Pedraza Ana S. , Vergara-Hernández Héctor J. , Chávez Jorge , Jimenez Omar , Mihalcea Elena , Arteaga Dante , Ruiz-Mondragón José J.
Published: August 2022

We present a novel Ti64/20Ag highly porous composite fabricated by powder metallurgy for biomedical applications and provide an insight into its microstructure and mechanical proprieties. In this work, the Ti64/20Ag highly porous composites were successfully fabricated by the space holder technique and consolidated by liquid phase sintering, at lower temperatures than the ones used for Ti64 materials. The sintering densification was evaluated by dilatometry tests and the microstructural characterization and porosity features were determined by scanning electron microscopy and computed microtomography. Permeability was estimated by numerical simulations on the 3D real microstructure. Mechanical properties were evaluated by simple compression tests. Densification was achieved by interparticle pore filling with liquid Ag that does not drain to the large pores, with additional densification due to the macroscopical deformation of large pores. Pore characteristics are closely linked to the pore formers and the permeability was highly increased by increasing the pore volume fraction, mainly because the connectivity was improved. As expected, with the increase in porosity, the mechanical properties decreased. These results permitted us to gain a greater understanding of the microstructure and to confirm that we developed a promising Ti64/20Ag composite, showing E of 7.4 GPa, σy of 123 MPa and permeability of 3.93 × 10−11 m2. Enhanced adaptability and antibacterial proprieties due to Ag were obtained for bone implant applications.