bluuebunny/crossref_metadata_2025 huggingface dataset:
ERK5 signalling pathway is a novel target of sorafenib: Implication in EGF biology
Authors: Ortega‐Muelas Marta , Roche Olga , Fernández‐Aroca Diego M. , Encinar José A. , Albandea‐Rodríguez David , Arconada‐Luque Elena , Pascual‐Serra Raquel , Muñoz Ismael , Sánchez‐Pérez Isabel , Belandia Borja , Ruiz‐Hidalgo María J. , Sánchez‐Prieto Ricardo
Published: October 2021

Sorafenib is a multikinase inhibitor widely used in cancer therapy with an antitumour effect related to biological processes as proliferation, migration or invasion, among others. Initially designed as a Raf inhibitor, Sorafenib was later shown to also block key molecules in tumour progression such as VEGFR and PDGFR. In addition, sorafenib has been connected with key signalling pathways in cancer such as EGFR/EGF. However, no definitive clue about the molecular mechanism linking sorafenib and EGF signalling pathway has been established so far. Our data in HeLa, U2OS, A549 and HEK293T cells, based on in silico, chemical and genetic approaches demonstrate that the MEK5/ERK5 signalling pathway is a novel target of sorafenib. In addition, our data show how sorafenib is able to block MEK5‐dependent phosphorylation of ERK5 in the Ser218/Tyr220, affecting the transcriptional activation associated with ERK5. Moreover, we demonstrate that some of the effects of this kinase inhibitor onto EGF biological responses, such as progression through cell cycle or migration, are mediated through the effect exerted onto ERK5 signalling pathway. Therefore, our observations describe a novel target of sorafenib, the ERK5 signalling pathway, and establish new mechanistic insights for the antitumour effect of this multikinase inhibitor.
Immunohistochemical detection of enteroviruses in pancreatic tissues of patients with type 1 diabetes using a polyclonal antibody against 2A protease of Coxsackievirus
Authors: Jimbo Erika , Kobayashi Tetsuro , Takeshita Akira , Mine Keiichiro , Nagafuchi Seiho , Fukui Tomoyasu , Yagihashi Soroku
Published: October 2021

Aims/Introduction

The need for antiserum for immunohistochemical (IHC) detection of enterovirus (EV) in formaldehyde‐fixed and paraffin‐embedded samples is increasing. The gold standard monoclonal antibody (clone 5D8/1) against EV‐envelope protein (VP1) was proven to cross‐react with other proteins. Another candidate marker of EV proteins is 2A protease (2Apro), which is encoded by the EV gene and translated by the host cells during EV replication, and participates processing proproteins to viral capsid proteins.

Materials and Methods

We raised polyclonal antiserum by immunizing a rabbit with an 18‐mer peptide of Coxsackievirus B1 (CVB1)‐2Apro, and examined the specificity and sensitivity for EV on formaldehyde‐fixed and paraffin‐embedded tissue samples.

Results

Enzyme‐linked immunosorbent assay study showed a high titer of antibody for 18‐mer peptide of CVB1‐2Apro, cross‐reacting with CVB3‐2Apro peptide. IHC showed that antiserum against 2Apro reacted with CVB1‐infected and VP1‐positive Vero cells. Confocal laser scanning microscopy showed that antigen stained by the 2Apro antibody located in the same cell with VP1 stained by 5D8/1. IHC using 2Apro antiserum showed dense staining in the islets of EV‐associated fulminant type 1 diabetes pancreas and that located in the same cell stained positive for VP1 (5D8/1). Specificity of 2Apro antiserum by IHC staining was confirmed by negative 2Apro in 14 VP1‐negative non‐diabetes control pancreases.

Conclusions

Our study provides a new polyclonal antiserum against CVB1‐2Apro, which might be useful for IHC of EV‐infected human tissues stored as archive of formaldehyde‐fixed and paraffin‐embedded tissue samples.
Diet and gut microbiome in fatty liver and its associated liver cancer
Authors: Pan Yasi , Zhang Xiang
Published: October 2021

Non‐alcoholic fatty liver disease (NAFLD) is the major cause of chronic liver disease worldwide as a consequence of a sedentary lifestyle and overnutrition. NAFLD could progress to non‐alcoholic steatohepatitis (NASH), which may further develop to cirrhosis and hepatocellular carcinoma (HCC). The gut microbiome is one of the central regulators in host metabolism. Diet could change human gut microbiome rapidly and reproducibly and modulate several metabolic pathways. Both diet and gut microbiome dysbiosis are associated with NAFLD and its related HCC (NAFLD‐HCC). Dietary cholesterol, fiber, fat, or carbohydrate could change the microbiome composition to contribute to the development of NASH and NAFLD‐HCC. Hence, identification of elements of the gut–liver axis that are primarily damaged in NASH and NAFLD‐HCC offers new possibility for therapeutic intervention. In this review, the roles of gut microbiome and microbial metabolites in the development and progression of NAFLD and NAFLD‐HCC are first discussed. The impacts of different diet compositions including cholesterol, fiber, fat, and sugar on the gut microbiome that leads to predisposition to NASH and NAFLD‐HCC are also explored. We summarized the article by discussing potential therapeutic implication of diet and microbiome modulation in fatty liver and liver cancer.
Microscopic analysis for the oxidation of sulphide‐bearing aggregate
Authors: Elmosallamy Mona , Shehata Medhat H.
Published: October 2021

Mortar samples were prepared with sulphide‐bearing aggregates and tested for the potential of aggregate oxidation followed by sulphate attack. Scanning Electron Microscopy and its associated Energy Dispersive X‐Ray analysis were used to analyze the developed phases in the tested samples to confirm that the obtained expansion is attributable to sulphate attack.  The Energy Dispersive X‐Ray analysis helped identify sulphide phases in aggregates and evidence of sulphate attack in mortars. Ettringite was detected and confirmed in the mortars with sulphide‐bearing aggregates suggesting that the test conditions are suitable for reproducing the damaging mechanism of sulphide oxidation.
Gene flow, linked selection, and divergent sorting of ancient polymorphism shape genomic divergence landscape in a group of edaphic specialists
Authors: Ke Fushi , Vasseur Liette , Yi Huiqin , Yang Lihua , Wei Xiao , Wang Baosheng , Kang Ming
Published: October 2021

Interpreting the formation of genomic variation landscape, especially genomic regions with elevated differentiation (i.e. islands), is fundamental to a better understanding of the genomic consequences of adaptation and speciation. Edaphic islands provide excellent systems for understanding the interplay of gene flow and selection in driving population divergence and speciation. However, discerning the relative contribution of these factors that modify patterns of genomic variation remains difficult. We analysed 132 genomes from five recently divergent species in Primulina genus, with four species distributed in Karst limestone habitats and the fifth one growing in Danxia habitats. We demonstrated that both gene flow and linked selection have contributed to genome‐wide variation landscape, where genomic regions with elevated differentiation (i.e., islands) were largely derived by divergent sorting of ancient polymorphism. Specifically, we identified several lineage‐specific genomic islands that might have facilitated adaptation of P. suichuanensis to Danxia habitats. Our study is amongst the first cases disentangling evolutionary processes that shape genomic variation of plant specialists, and demonstrates the important role of ancient polymorphism in the formation of genomic islands that potentially mediate adaptation and speciation of endemic plants in special soil habitats.
When I say … Situation
Authors: Vass Alyssa , Adams Karen
Published: October 2021

In this latest contribution to the ‘When I say … ’ series, Vass and Adams explore the pervasive impact of colonisation as an under‐recognised and poorly addressed context of medical education.
A constitutive stress response is a result of low temperature growth in the Antarctic green algaChlamydomonassp.UWO241
Authors: Cvetkovska Marina , Zhang Xi , Vakulenko Galyna , Benzaquen Samuel , Szyszka‐Mroz Beth , Malczewski Nina , Smith David R. , Hüner Norman P.A.
Published: October 2021

The Antarctic green algaChlamydomonassp. UWO241 is an obligate psychrophile that thrives in the cold (4–6°C) but is unable to survive at temperatures ≥18°C. Little is known how exposure to heat affects its physiology or whether it mounts a heat stress response in a manner comparable to mesophiles. Here, we dissect the responses of UWO241 to temperature stress by examining its growth, primary metabolome and transcriptome under steady‐state low temperature and heat stress conditions. In comparison withChlamydomonas reinhardtii, UWO241 constitutively accumulates metabolites and proteins commonly considered as stress markers, including soluble sugars, antioxidants, polyamines, and heat shock proteins to ensure efficient protein folding at low temperatures. We propose that this results from life at extreme conditions. A shift from 4°C to a non‐permissive temperature of 24°C alters the UWO241 primary metabolome and transcriptome, but growth of UWO241 at higher permissive temperatures (10 and 15°C) does not provide enhanced heat protection. UWO241 also fails to induce the accumulation of HSPs when exposed to heat, suggesting that it has lost the ability to fine‐tune its heat stress response. Our work adds to the growing body of research on temperature stress in psychrophiles, many of which are threatened by climate change.
Predicting biochemical acclimation of leaf photosynthesis in soybean under in‐field canopy warming using hyperspectral reflectance
Authors: Kumagai Etsushi , Burroughs Charles H. , Pederson Taylor L. , Montes Christopher M. , Peng Bin , Kimm Hyungsuk , Guan Kaiyu , Ainsworth Elizabeth A. , Bernacchi Carl J.
Published: October 2021

Traditional gas exchange measurements are cumbersome, which makes it difficult to capture variation in biochemical parameters, namely the maximum rate of carboxylation measured at a reference temperature (Vcmax25) and the maximum electron transport at a reference temperature (Jmax25), in response to growth temperature over time from days to weeks. Hyperspectral reflectance provides reliable measures of Vcmax25 and Jmax25; however, the capability of this method to capture biochemical acclimations of the two parameters to high growth temperature over time has not been demonstrated. In this study, Vcmax25 and Jmax25 were measured over multiple growth stages during two growing seasons for field‐grown soybeans using both gas exchange techniques and leaf spectral reflectance under ambient and four elevated canopy temperature treatments (ambient+1.5, +3, +4.5, and +6°C). Spectral vegetation indices and machine learning methods were used to build predictive models for Vcmax25 and Jmax25, based on the leaf reflectance. Results showed that these models yielded an R2 of 0.57–0.65 and 0.48–0.58 for Vcmax25 and Jmax25, respectively. Hyperspectral reflectance captured biochemical acclimation of leaf photosynthesis to high temperature in the field, improving spatial and temporal resolution in the ability to assess the impact of future warming on crop productivity.
Near‐infrared spectroscopy aids ecological restoration by classifying variation of taxonomy and phenology of a native shrub
Authors: Robb Brecken C. , Olsoy Peter J. , Mitchell Jessica J. , Caughlin T. Trevor , Delparte Donna M. , Galla Stephanie J. , Fremgen‐Tarantino Marcella R. , Nobler Jordan D. , Rachlow Janet L. , Shipley Lisa A. , Forbey Jennifer S.
Published: October 2021

Plant communities are composed of complex phenotypes that not only differ among taxonomic groups and habitats but also change over time within a species. Restoration projects (e.g. translocations and reseeding) can introduce new functional variation in plants, which further diversifies phenotypes and complicates our ability to identify locally adaptive phenotypes for future restoration. Near‐infrared spectroscopy (NIRS) offers one approach to detect the chemical phenotypes that differentiate plant species, populations, and phenological states of individual plants over time. We use sagebrush (Artemisia spp.) as a case study to test the accuracy by which NIRS can classify variation within taxonomy and phenology of a plant that is extensively managed and restored. Our results demonstrated that NIRS can accurately classify species of sagebrush within a study site (75–96%), populations of sagebrush within a subspecies (99%), annual phenology within a population (>99%), and seasonal phenology within individual plants (>97%). Low classification accuracy by NIRS in some sites may reflect heterogeneity associated with natural hybridization, translocation of nonlocal seed sources from past restoration, or complex gene‐by‐environment interactions. Advances in our ability to detect and interpret spectral signals from plants may improve both the selection of seed sources for targeted conservation and the capacity to monitor long‐term changes in vegetation.
The institution of medicine and transgender identity construction: Between a doc and a hard place
Authors: Toman Lindsay
Published: October 2021

Research shows that when transgender young people are well‐supported throughout their gender transition they have similar levels of depression to their cisgender counterparts. For transgender young people who wish to transition medically, these support systems may include parents as advocates and healthcare professionals who specialize in transgender services. Decisions about steps throughout transition are made by transgender children, their parents, and their physicians. An examination of gender structure theory and medicalization literature helps to assess how medicine‐on institutional, interactional, and individual levels‐contributes to cisnormativity and enables us to reflect on the relationships among sex, gender, and science. This literature review aims to analyze how cultural ideologies influence medical processes that shape the identity construction of transgender children and it sheds light on parental involvement throughout transitions.
Gender differences in the perceptions of green spaces characteristics
Authors: Braçe Olta , Garrido‐Cumbrera Marco , Correa‐Fernández José
Published: October 2021

Objective

Urban green spaces provide a wide range of health benefits for the population and, therefore, their use should be promoted. However, men and women perceive and value the characteristics of urban green spaces differently, as both have different sensitivities and expectations. The present study aims to identify gender differences in the perceptions of urban green spaces characteristics.

Methods

Gender differences in the perceptions of eleven urban green spaces characteristics were assessed, including lighting, safety, cleanliness, walking routes, bike lanes, shaded areas, recreational areas, off‐leash dog areas, children's playgrounds, drinking fountains, and pleasant views.

Results

Our results showed that women attribute a higher value to all the characteristics of the urban green spaces analyzed, being the most appreciated the presence of off‐leash dog areas, lighting, children's playgrounds, pleasant views, drinking fountains, safety and recreational areas. In addition, older and more educated people, unemployed women, and single men consider green spaces to be highly important.

Conclusion

The results of this study provide evidence for the adequate planning, design and development of urban green spaces that meet the needs of all users.
Social distance attitudes, educational mobility, and European ancestry groups in the post‐World‐War II United States
Authors: Boyd Robert L.
Published: October 2021

Objective

This study examines the improvement of U.S. natives’ social distance attitudes toward Southern, Central, and Eastern (SCE) European ancestry groups in the post‐World‐War II United States, applying the idea that prejudice against these groups was due to racial/ethnic prejudice and social class prejudice.

Methods

Analyzing data from the Bogardus surveys and other published sources, the study tests the proposition that U.S. natives’ social distance attitudes toward SCE European ancestry groups improved because social class prejudice against these groups diminished as the groups’ educational attainment levels increased from the second‐ to third‐generations.

Results

Contrary to modernization and classical assimilation theories, the favorable trend in U.S. natives’ social distance attitudes toward SCE European ancestry groups was unaffected by the groups’ intergenerational educational mobility.

Conclusion

The decline in prejudice against SCE European ancestry groups in the postwar United States resulted from a decrease in racial/ethnic prejudice against these groups, independently of social class prejudice.
Interprofessional learning about medication safety
Authors: Young Joanne , Zolio Luigi , Brock Tina , Harrison Julia , Hodgkinson Marisa , Kumar Arunaz , Morphet Julia , Kent Fiona
Published: October 2021

Background

Safe medication management requires collaboration between health professionals.

Approach

A mixed academic and clinician team co‐designed and co‐facilitated a 2‐h interprofessional medication safety workshop, covering medication history taking, perioperative medication management, discharge planning, incident review and dosing and administration calculations. Three workshop sessions were delivered across three sites during September 2019 at a large metropolitan healthcare network. Senior nursing, medical and pharmacy students were invited to participate in the workshops and evaluation.

Evaluation

We evaluated satisfaction, learning experience and perceived clinical application for medical, pharmacy and nursing students. Surveys were conducted immediately after each workshop and at 4 weeks. Quantitative data was analysed descriptively and qualitative data analysed using thematic analysis. Forty‐five students participated in the evaluative component of the workshops. Mean student response scores demonstrated a high level of satisfaction with the workshop's relevance and utility to their learning. Students expressed strong agreement that the workshop promoted communication across professions for medication safety. Analysis of the qualitative data identified seven key themes, with consistently positive responses provided in each: interactions within the interprofessional team; recognising the importance of teams; learning the process of medication use; acknowledging and working with difference; role playing; thinking patient safety; and authenticity.

Implications

A 2‐h interprofessional workshop about medication safety provided positive learning experiences with high satisfaction to medical, nursing and pharmacy students, and had strong perceived applicability to their future clinical practice.
Large structural variations in the haplotype‐resolved African cassava genome
Authors: Mansfeld Ben N. , Boyher Adam , Berry Jeffrey C. , Wilson Mark , Ou Shujun , Polydore Seth , Michael Todd P. , Fahlgren Noah , Bart Rebecca S.
Published: October 2021

Cassava (Manihot esculentaCrantz, 2n = 36) is a global food security crop. It has a highly heterozygous genome, high genetic load, and genotype‐dependent asynchronous flowering. It is typically propagated by stem cuttings and any genetic variation between haplotypes, including large structural variations, is preserved by such clonal propagation. Traditional genome assembly approaches generate a collapsed haplotype representation of the genome. In highly heterozygous plants, this results in artifacts and an oversimplification of heterozygous regions. We used a combination of Pacific Biosciences (PacBio), Illumina, and Hi‐C to resolve each haplotype of the genome of a farmer‐preferred cassava line, TME7 (Oko‐iyawo). PacBio reads were assembled using the FALCON suite. Phase switch errors were corrected using FALCON‐Phase and Hi‐C read data. The ultralong‐range information from Hi‐C sequencing was also used for scaffolding. Comparison of the two phases revealed >5000 large haplotype‐specific structural variants affecting over 8 Mb, including insertions and deletions spanning thousands of base pairs. The potential of these variants to affect allele‐specific expression was further explored. RNA‐sequencing data from 11 different tissue types were mapped against the scaffolded haploid assembly and gene expression data are incorporated into our existing easy‐to‐use web‐based interface to facilitate use by the broader plant science community. These two assemblies provide an excellent means to study the effects of heterozygosity, haplotype‐specific structural variation, gene hemizygosity, and allele‐specific gene expression contributing to important agricultural traits and further our understanding of the genetics and domestication of cassava.
Constitutively enhanced genome integrity maintenance and direct stress mitigation characterize transcriptome of extreme stress‐adapted Arabidopsis halleri
Authors: Lee Gwonjin , Ahmadi Hassan , Quintana Julia , Syllwasschy Lara , Janina Nadežda , Preite Veronica , Anderson Justin E. , Pietzenuk Björn , Krämer Ute
Published: October 2021

Heavy metal‐rich toxic soils and ordinary soils are both natural habitats of Arabidopsis halleri, a diploid perennial and obligate outcrosser in the sister clade of the genetic model plant Arabidopsis thaliana. The molecular divergence underlying survival in sharply contrasting environments is unknown. Here we comparatively address metal physiology and transcriptomes of A. halleri originating from the most highly heavy metal‐contaminated soil in Europe, Ponte Nossa, Italy (Noss), and from non‐metalliferous (NM) soils. Plants from Noss exhibit enhanced hypertolerance and attenuated accumulation of cadmium (Cd), and their transcriptomic Cd responsiveness is decreased, compared to plants of NM soil origin. Among the condition‐independent transcriptome characteristics of Noss, the most highly overrepresented functional class of ‘meiotic cell cycle’ comprises 21 transcripts with elevated abundance in vegetative tissues, in particular Argonaute 9 (AGO9) and the synaptonemal complex transverse filament protein‐encoding ZYP1a/b. Increased AGO9 transcript levels in Noss are accompanied by decreased long terminal repeat retrotransposon expression. Similar to Noss, plants from other highly metalliferous sites in Poland and Germany share elevated somatic AGO9 transcript levels in comparison to plants originating from NM soils in their respective geographic regions. Transcript levels of Iron‐Regulated Transporter 1 (IRT1) are very low and transcript levels of Heavy Metal ATPase 2 (HMA2) are strongly elevated in Noss, which can account for its altered Cd handling. We conclude that in plants adapted to the most extreme abiotic stress, broadly enhanced functions comprise genes with likely roles in somatic genome integrity maintenance, accompanied by few alterations in stress‐specific functional networks.
Diagnostic algorithm for classification and characterization of direct antiglobulin test‐negative autoimmune hemolytic anemia with 1‐year clinical follow‐up
Authors: Kamesaki Toyomi
Published: October 2021

Background

Approximately 5%–10% of autoimmune hemolytic anemia (AIHA) cases are negative for direct antiglobulin test (DAT). We previously reported a classification system for untreated patients with DAT‐negative AIHA by quantifying levels of red blood cell (RBC)‐bound IgG. This study investigated the clinical utility of a novel diagnostic algorithm with a comprehensive classification system and characterized each subgroup in DAT‐negative AIHA.

Study Design and Methods

We assessed 637 patients with undiagnosed hemolytic anemia using our diagnostic algorithm and classification system, which was based on RBC‐bound IgG levels and results of column method‐DAT before and after washing RBCs.

Results

Patients were diagnosed with DAT‐negative AIHA with 97% sensitivity and 84% specificity when the laboratory tests were performed before treatment and classified into the following six categories: tube DAT‐negative, low‐affinity IgG, double DAT‐negative, IgA‐ or IgM‐positive, low‐affinity IgM, and s/o non‐AIHA. The first three types were major conditions and accounted for 76% of DAT‐negative AIHA cases. Based on multivariate analyses of idiopathic DAT‐negative AIHA (n = 71), platelet count and albumin concentration were significant factors for survival at 1‐year follow‐up. The low‐affinity IgG group showed the highest platelet count and albumin levels, better response to steroids, and higher 1‐year survival rate than those in other groups.

Discussion

Our classification included DAT‐negative, IgA‐driven, and warm‐IgM AIHA categories, which were atypical forms of AIHA with the severe onset and increased risk of relapse. When treating a patient with DAT‐negative hemolysis, atypical AIHA should be considered and tested in reference laboratories, especially before treatment.
Threshold effects of openness on real and nominal effective exchange rates in emerging and developing economies
Authors: Glebocki Keefe Helena , Saha Sujata
Published: October 2021

In this paper, we assess the direct and indirect effects of the degree of openness in emerging and developing economies on exchange rate movements. Using threshold regression analysis for twenty‐five economies for the period of 2000–2017, we find that changes in inflation, interest rate differentials and government debt have a more sizable and significant effect on real effective exchange rates in less open economies, which is not detected in countries with openness above the threshold value. In more open economies, nominal effective exchange rate movements are driven by interest rate differentials and real GDP growth. However, the exchange rate response is still smaller than in less open economies. Lastly, the measure of openness matters. Evidence of threshold effects is most significant when considering overall openness with the KOF Globalisation Index, rather than the traditional measure of trade openness alone.
Dissolved oxygen technologies as a novel strategy for non‐healing wounds: A critical review
Authors: Ntentakis Dimitrios P. , Ntentaki Anastasia Maria , Delavogia Eleni , Kalomoiris Loukas , Venieri Danae , Arkadopoulos Nikolaos , Kalogerakis Nicolas
Published: October 2021

Non‐healing wounds are steadily becoming a global‐health issue. Prolonged hypoxia propagates wound chronicity; yet, oxygenating treatments are considered inadequate to date. Dissolved oxygen (DO) in aqueous solutions introduces a novel approach to enhanced wound oxygenation, and is robustly evaluated for clinical applications. A systematic literature search was conducted, whereby experimental and clinical studies of DO technologies were categorized per engineering approach. Technical principles, methodology, endpoints and outcomes were analysed for both oxygenating and healing effects. Forty articles meeting our inclusion criteria were grouped as follows: DO solutions (17), oxygen (O2) dressings (9), O2 hydrogels (11) and O2 emulsions (3). All technologies improved wound oxygenation, each to a variable degree. They also achieved at least one statistically significant outcome related to wound healing, mainly in epithelialization, angiogenesis and collagen synthesis. Scarcity in clinical data and methodological variability precluded quantitative comparisons among the biotechnologies studied. DO technologies warrantee further evaluation for wound oxygenation in the clinical setting. Standardised methodologies and targeted research questions are pivotal to facilitate global integration in healthcare.
A New Turbomachine for Clean and Sustainable Hydrocarbon Cracking
Authors: Rubini Dylan , Xu Liping , Rosic Budimir , Johannesdahl Harri
Published: October 2021

Decarbonizing highly energy-intensive industrial processes is imperative if nations are to comply with anthropogenic greenhouse gas emissions targets by 2050. This is a significant challenge for high-temperature industrial processes, such as hydrocarbon cracking, and there have been limited developments thus far. The novel concept presented in this study aims to replace the radiant section of a hydrocarbon cracking plant with a novel turboreactor. This is one of the first major and potentially successful attempts at decarbonizing the petrochemical industry. Rather than using heat from the combustion of natural gas, the novel turboreactor can be driven by an electric motor powered by renewable electricity. Switching the fundamental energy transfer mechanism from surface heat exchange to mechanical energy transfer significantly increases the exergy efficiency of the process. Theoretical analysis and numerical simulations show that the ultrahigh aerodynamic loading rotor is able to impart substantial mechanical energy into the feedstock without excess temperature difference and metal temperature magnitude. A complex shockwave system then transforms the kinetic energy into internal energy over an extremely short distance. The version of the turboreactor developed and presented in this study uses a single rotor row, in which a multistage environment is achieved regeneratively by guiding the flow through a toroidal-shaped vaneless space. This configuration leads to a reduction in reactor volume by more than two orders of magnitude compared with a conventional furnace. A significantly lower wall surface temperature, supersonic gas velocities, and a shorter primary gas path enable a controlled reduction in the residence time for chemical reactions, which optimizes the yield. For the same reasons, the conditions for coke deposition on the turboreactor surfaces are unfavorable, leading to an increase in plant availability. This study demonstrates that the mechanical work input into the feedstock can be dissipated through an intense turbulent mixing process, which maintains an ideal and controlled pressure level for cracking.
Comprehensive Effects of Polymer Flooding on Oil–Water Relative Permeabilities
Authors: Wang Qiong , Jiang Ruizhong
Published: October 2021

Many reports have indicated that, in contrast to waterflooding, oil–water relative permeabilities in polymer flooding are influenced by the polymer properties, such as adsorption and viscoelasticity. Long-term injected polymer solutions flush the reservoir porous media causing wettability alteration and residual oil reduction, which is also an important factor for oil–water relative permeabilities. Therefore, the comprehensive effects of polymer properties and dynamic flushing on two-phase percolation behavior have been the focus of research. In this study, polymer flow experiments, including pre-shearing, relative permeability, and long-term erosion tests, were first conducted. Then, a flushing-interpolation model, including polymer concentration interpolation and surface flux characterization, was developed to dynamically describe the two-phase flow characteristics. Based on the experimental results and the presented dynamic model, polymer-flooding simulations were conducted to analyze the performance of the well and the distribution of the remaining oil. The results indicate that flushing reduces the residual oil saturation, and the viscoelasticity effect further broadens the predominant flushing channels horizontally; both effects lead to higher cumulative oil production and a lower water-cut. Additionally, including the flushing effect in the polymer-flooding model leads to a more reliable numerical prediction of the remaining oil distribution. To account for the comprehensive effects of viscoelasticity and erosion in field applications, water-cut history matching was performed for the studied well group, and the error decreased to 4.39%. Finally, the optimal polymer concentration for high-concentration polymer-flooding programs was determined to be 1450 mg/L.
Water Hammer Simulation in Two-Phase Flow Regimes Using Open Source Code OpenFOAM
Authors: Fuchs Paul , Koch Marco K.
Published: October 2021

Water hammer phenomena in pipe systems are simulated with the open source code OpenFOAM-v7. Effects like dynamic pressure changes caused by fast closing valves, wave propagation, reflection and interference as well as cavitation and fluid structure interaction are focussed in detailed CFD analysis.

In this paper two experiments conducted at the „Cold Water Hammer Test Facility” (CWHTF) at Helmholtz-Zentrum Dresden-Rossendorf, Germany are simulated. The experiments show large steam bubbles collapse causing a pressure wave to travel within the pipe system. In order to capture cavitation effects the model basis of the Volume of Fluid based, fully compressible, multi fluid solver compressibleMultiphaseInterFoam is modified. The implementation of the mass transfer terms as well as the modification of the Kunz cavitation model is described and first simulation results are presented. Furthermore, an analytical approach is implemented to model effects of fluid structure interaction with the surrounding pipe. This approach computes the liquid sonic speed in relation with structural parameters of the deformable pipe in combination with a modified equation of state.

The simulation results show that the bubble collapsing speed is computed in good accordance to the experiment regarding the timing of the initial pressure peak fits the experimental data. However, the amplitude of the pressure peak is overestimated by 22% neglecting any fluid structure interaction effects. Using the analytical approach to calculate the pipe deformation effects the overestimation of the pressure peak reduces to 8%.
Analyses of Wet and Dry Cavity Strategies for BWR Severe Accident Management With MELCOR-2.2
Authors: Takashima Ayato , Yamaji Akifumi , Li Xin , Fujiwara Daisuke , Shirai Hiroshi , Noujuu Takumi
Published: October 2021

The current severe accident management measure for Boiling Water Reactors (BWRs) in Japan adopts pre-flooding of the drywell (D/W) floor when the reactor pressure vessel (RPV) is expected to fail to prevent failure of the primary containment vessel (PCV) (wet cavity strategy). This prioritizes rapid cooling of the corium and is expected to lead to more steam generation at the time of the RPV failure. The purpose of this study is to evaluate the influences of changes in the accident management measure on PCV integrity / failure mode and the amount of radioactive material released to the environment for BWRs. The accident scenario has been tentatively defined as the TQUV scenario, in which the water injection is assumed to fail after the RPV depressurization. A set of MELCOR analysis models, which had been used for the Fukushima accident analyses has been adopted to represent TQUV event of BWR4/Mark-I. The effects of fuel coolant interaction (FCI) has not been considered in the current modeling. The analysis results show that in the case without pre-flooding D/W, the D/W wall temperature exceeded 200°C (which may be regarded as a rough estimate for the PCV failure by overheating) in about 30 minutes after the RPV failure. On the other hand, if water is continuously poured onto the D/W floor after the RPV failure, overheating failure of the PCV can be avoided, but over-pressure failure may occur within a few hours after the RPV failure.
Simulation Research of Combustion Characteristics of Mixed Sodium Fire in a Columnar Flow
Authors: Ma Yao-long , Zhang Zhi-gang , Wu Qi , Wang Fang
Published: October 2021

Sodium fire accident which was caused by the leakage of liquid sodium is the design basis accidents of sodium-cooled fast reactor. The column flow is a more realistic form of liquid sodium leakage due to the pipe system insulation structure and lower pressure in the sodium-cooled fast reactor. The leaked liquid sodium would combust in the form of columnar fire in the space and pool fire on the ground at the same time to form a mixed sodium fire in a columnar flow. In this paper, a numerical calculation model is established to simulate mixed sodium combustion in a columnar flow. This model is based on the turbulence model, discrete phase model and finite-rate model in Fluent software, and combined with chemical kinetic of sodium combustion. Several variables like spatial temperature, oxygen concentration and pressure during combustion of mixed sodium fire are calculated, and validated with experimental data collected in previous mixed sodium combustion experiment. Besides, the oxygen concentration and the temperature field are calculated for further study of the experiment. The result shows that the spatial temperature calculated by the code coincides well with the experiment, but the chamber pressure cannot be predicted precisely. The oxygen concentration in the center of the sodium flow would decline rapidly in the early stage, then remains at around 5%, but the oxygen concentration in the distance is relatively high. This study could provide reference for evaluation and prevention measures of sodium fire.
Investigation and Design of Energy-Absorbing Structure in Nuclear Fuel Cask
Authors: Hao Yuchen , Li Yue , Wang Jinhua , Wu Bin , Ma Tao , Wang Haitao
Published: October 2021

High Temperature Gas Cooled Reactor is considered as one of the most advanced reactors in the GEN-IV reactor system with inherent safety and high generating efficiency. Now, the project of High Temperature Reactor Pebble bed Module (HTR-PM) designed by Tsinghua university is going to finish construction. The first products of nuclear fuel elements have been transported to the Shidao Bay NPP that is ready to provide fuel power for a subsequent grid-connected generation. HTR-PM employs spherical fuel elements instead of common fuel assemblies. They have significant differences in geometry, structure, and mechanical property. The existing transfer cask for fuel assemblies doesn’t seem appropriate anymore. Therefore, it is necessary to find a new cask to meet this demand for nuclear fuel. One of the most important things is the application of lightweight technology which can promote transport efficiency and enhance the economy. Besides, referring to the safety code required by IAEA, the procedure of radioactive material transportation is strictly controlled, hence we should pay attention to both lightweight and safety. Research has focused on the new energy-absorbing structure and performance.

In this paper, we concentrate on cushioning effect of the thin-walled metal box with foam, rather than the normal structure of metal tube filled with foam. This structure will be assembled in one special type of nuclear fuel container to provide energy-absorbing and cushioning effect. The shape of foam specimen is cuboid, and the metal material is attached to it. First of all, we investigate the drop ball test. This study takes two sets of control group. One is a thin-walled box without foam, the other only has foam. Compared with the control group, the cushioning effect of energy-absorbing box is investigated. Secondly, the energy-absorbing structure is tied with the steel block and drop them from 9m height. Then sensitive analysis has been conducted to study the effect of design parameters and multi-work condition, to reveal some empirical regularities. This paper intends to provide important design experiences and references for energy-absorbing structure of nuclear fuel cask.
Development of Liquid-Particle Image Reconstruction Method in Centrifugal Field by Linear Sensor Wireless Electrical Resistance Tomography (LS-WERT)
Authors: Kimura Kota , Prayitno Yosephus Ardean Kurnianto , Sejati Prima Asmara , Zhao Tong , Iso Yoshiyuki , Takei Masahiro
Published: October 2021

A real-time measurement on the radiochemical processes in nuclear industry is crucial in order to monitoring the process frequently. Recently, a wireless electrical resistance tomography (WERT) with circumferential electrode was developed for the real-time measurement. However, due to the limitation in the circumferential section, we propose a linear sensor-wireless electrical resistance tomography (LS-WERT). This system is detecting the particle deposition thickness in the longitudinal positions. A coupling simulation of smoothed particle hydrodynamics and discrete element model (SPH-DEM) method is used to observe the particle-liquid behavior under centrifugal field. The distribution of particle and liquid phase in this simulation is then measured by an electrical impedance tomography (EIT) simulation. SPH-DEM-EIT coupling includes the converting process from DEM to FEM. An Artificial Neural Network (ANN) is applied with input from the electrical measurement results of the coupling. ANN for LS-WERT gives result in three categories of air, liquid, and particle phase. We evaluate the real-time particle deposition thickness by comparing the LS-WERT result to the high-speed camera images. As a result, LS-WERT has an average accuracy of 2.27% under rotating speed below 220 rpm. In overall, LS-WERT gives a good tendency to the high-speed camera images and effective for the application on real-time measurement of high-speed centrifuge.
Risk Analysis of Gasification Process of Nuclear Fuel Manufacturing Facilities Based on FTA
Authors: Yang Xiaowei , Lyu Dan , Que Ji , Liu Yuntao , Zhao Shangui
Published: October 2021

The process of nuclear fuel manufacturing is complicated. The process conditions are strict, and some materials required for the production process are flammable, explosive, chemically toxic and corrosive. As the scale of production increases, the automation of production equipment increases, it is necessary to assess risk of nuclear fuel manufacturing facilities, identify the risk factors of equipment or production processes, analyse hazards, and improve measures, with the objective of protecting staff, the public and environment.

Risk assessment methods mainly include safety checklist analysis, what-if analysis, Hazard and Operability Analysis (HAZOP), Failure Mode and Effects Analysis (FMEA), Fault Tree Analysis (FTA), Event Tree Analysis (ETA), etc. Various analytical methods are applicable to different stages of the engineering development process.[1]

At present, nuclear fuel manufacturing facilities in China do not use risk assessment methods to identify hazards in the design, construction and operation stages. It is only Experience-based engineering judgment and lack of systematicity. In this paper, the gasification chest UF6 leakage is the top event, and the fault tree model is established for the gasification process. Qualitative and preliminary quantitative analysis is carried out to identify the key links that need to strengthen the design. It provides suggestions for improving the reliability of the system and equipment.
Study on Deposition Motion of Naturally Circulating Particulate Matter in Supercritical Water Based on Factor and Correspondence Analysis
Authors: Qi Tian , Zhou Tao , Chen Ning , Chen Juan
Published: October 2021

It is very important to study the deposition of particles in natural circulation of supercritical water to ensure the safe and stable operation of supercritical water reactor. The data of natural circulation loop calculated by ANSYS-CFX simulation software were analyzed by factorial analysis method, and the effects of axial distance, initial particle volume fraction, heating power and particle size on particle deposition were obtained. The results show that the contribution rate of particle size to the deposition rate is the largest, about 36.3%, and the contribution rate of initial particle concentration to the deposition rate is about 15.1%; the interaction between axial distance and heating power is the most obvious, and the interaction effect is the pipe temperature distribution. Through correspondence analysis, the main influencing factors of particle deposition rate at each level were analyzed. The results show that: when the deposition rate is small, the small change of axial distance will also have a greater impact on the deposition of particles; when the deposition rate is further increased, the change of initial particle volume fraction will significantly affect the deposition of particles; when the deposition rate is large, the particle size plays a leading role in the deposition of particles. Both of the two analysis methods show that: in the influence on the deposition of particles in supercritical water natural circulation, the influence degree is particle size > concentration > axial distance > heating power. Based on the two analysis methods, an analysis regression model is established and the volume proportion of particles in natural circulation is predicted.
Numerical Investigation of Safety System Parameters in Molten Salt Reactor: Wall Effect on Freeze Valve Opening Time
Authors: Ilham Muhammad , Aji Indarta Kuncoro , Okawa Tomio
Published: October 2021

Molten Salt Reactor (MSRs) is one of the fourth generation Nuclear Power Plants with better capabilities and potentialities compared to previous generation, the enthusiasm for molten fuel reactor has been increasing around the world. MSRs has passive safety where if the core is overheating cause by accident event, the liquid salt fuel was required to be moved to the safety drain tank underneath the core vessel by gravity force. During this occasion, the freeze valve (FV) that formed in the pipe located between the core and drain tank must be melt out promptly to prevent the vessel to reach it is melting point. In this paper, we conduct on thermal analysis of the freeze valve at the solidification and melting process based on finite elements methods. The enthalpy-porosity method adopted by ANSYS Fluent was used to simulated the designed system at specified condition. The Oak Ridge National Laboratory of Molten Salt Reactor Experiment Freeze valve system was used as a references for parameters investigation. Using pipe wall thickness of 5 mm, 10 mm, and 15 mm to examined the wall effect to thermal properties of the designed freeze valve. The wall pipe for FV systems material was also investigate in order to examine its effect to the opening time. Further, the temperature distributions of the valve system were obtained and analyzed. It was found that the wall effect has significant impact to the solidification and melting process.
Prediction of Iodine Peak and Iodine Purification Time in PWR Nuclear Power Plant With Defective Fuel Rods
Authors: Wang Liang , Liu Zhiyuan , Liu Fei , Zhang Chunming , Liu Fudong , Ye Yuanlv
Published: October 2021

For light water reactor (LWR), if fuel rods failure occurs, the fission products (FP) will be released into the primary coolant, which will affect radiation safety, cause adverse environmental impact and economic loss. When fuel defects occur in nuclear power units, the prediction of iodine peak usually refers to the results of NRC research of the US Nuclear Regulatory Commission: the peak effect during the shutdown can make the activity value of primary loop FP (iodine and RIG) be 10–1000 times of that during normal operation This method is evaluated from a statistical point of view and has little significance for the actual operation of the nuclear power plants. The main reason is that the release rate from the cladding to the primary circuit is not considered in the calculation of the iodine peak purification time. Combined with the actual power operation data of the WWER units, the difference between RIG escape and iodine release is analyzed from the mechanism. Based on the actual power operation data, the calculation model of fission nuclide activity concentration in the primary circuit is established, and a method to predict the iodine peak size and purification time is finally obtained. In the case of fuel rods failure, the peak value of iodine-131 during the shutdown was estimated, and the purification time and final concentration from purification to reactor opening were estimated, which ensured the overhaul progress of the nuclear power plant.