bluuebunny/crossref_metadata_2025 huggingface dataset:
Horses for Courses in the Era of CARs: Advancing CAR T and CAR NK Cell Therapies
Authors: Kulemzin Sergey , Evsyukov Igor , Belovezhets Tatiana , Taranin Alexander , Gorchakov Andrey
Published: November 2021

The adoptive transfer of allogeneic CAR NK cells holds great promise as an anticancer modality due to the relative ease of manufacturing and genetic modification of NK cells, which translates into affordable pricing. Compared to the pronounced efficacy of CAR T cell therapy in the treatment of B cell malignancies, rigorous clinical and preclinical assessment of the antitumor properties of CAR NK cells has been lagging behind. In this brief review, we summarize the biological features of NK cells that may help define the therapeutic niche of CAR NK cells as well as create more potent NK cell-based anticancer products. In addition, we compare T cells and NK cells as the carriers of CARs using the data of single-cell transcriptomic analysis.
An Emerging Role for Epigenetics in Cerebral Palsy
Authors: Romero Brigette , Robinson Karyn G. , Batish Mona , Akins Robert E.
Published: November 2021

Cerebral palsy is a set of common, severe, motor disabilities categorized by a static, nondegenerative encephalopathy arising in the developing brain and associated with deficits in movement, posture, and activity. Spastic CP, which is the most common type, involves high muscle tone and is associated with altered muscle function including poor muscle growth and contracture, increased extracellular matrix deposition, microanatomic disruption, musculoskeletal deformities, weakness, and difficult movement control. These muscle-related manifestations of CP are major causes of progressive debilitation and frequently require intensive surgical and therapeutic intervention to control. Current clinical approaches involve sophisticated consideration of biomechanics, radiologic assessments, and movement analyses, but outcomes remain difficult to predict. There is a need for more precise and personalized approaches involving omics technologies, data science, and advanced analytics. An improved understanding of muscle involvement in spastic CP is needed. Unfortunately, the fundamental mechanisms and molecular pathways contributing to altered muscle function in spastic CP are only partially understood. In this review, we outline evidence supporting the emerging hypothesis that epigenetic phenomena play significant roles in musculoskeletal manifestations of CP.
Pharmacogenetically Guided Escitalopram Treatment for Pediatric Anxiety Disorders: Protocol for a Double-Blind Randomized Trial
Authors: Strawn Jeffrey R. , Poweleit Ethan A. , Mills Jeffrey A. , Schroeder Heidi K. , Neptune Zoe A. , Specht Ashley M. , Farrow Jenni E. , Zhang Xue , Martin Lisa J. , Ramsey Laura B.
Published: November 2021

Current pharmacologic treatments for pediatric anxiety disorders (e.g., selective serotonin reuptake inhibitors (SSRIs)) frequently use “one size fits all” dosing strategies based on average responses in clinical trials. However, for some SSRIs, including escitalopram, variation in CYP2C19 activity produces substantial variation in medication exposure (i.e., blood medication concentrations). This raises an important question: would refining current SSRI dosing strategies based on CYP2C19 phenotypes increase response and reduce side effect burden? To answer this question, we designed a randomized, double-blind trial of adolescents 12–17 years of age with generalized, separation, and/or social anxiety disorders (N = 132). Patients are randomized (1:1) to standard escitalopram dosing or dosing based on validated CYP2C19 phenotypes for escitalopram metabolism. Using this approach, we will determine whether pharmacogenetically-guided treatment—compared to standard dosing—produces faster and greater reduction in anxiety symptoms (i.e., response) and improves tolerability (e.g., decreased risk of treatment-related activation and weight gain). Secondarily, we will examine pharmacodynamic variants associated with treatment outcomes, thus enhancing clinicians’ ability to predict response and tolerability. Ultimately, developing a strategy to optimize dosing for individual patients could accelerate response while decreasing side effects—an immediate benefit to patients and their families. ClinicalTrials.gov Identifier: NCT04623099.
Long Term Metabolic and Inflammatory Effects of Second-Generation Antipsychotics: A Study in Mentally Disordered Offenders
Authors: Vassilopoulou Emilia , Efthymiou Dimitris , Papatriantafyllou Evangelia , Markopoulou Maria , Sakellariou Efthymia-Maria , Popescu Alina Codruta
Published: November 2021

Mentally disordered offenders provided with forensic psychiatric care are often treated with second generation antipsychotic (SGA) medication and experience metabolic and inflammatory side effects. Aim: In this paper, we monitored the three-year fluctuation of selected anthropometric, biochemical, and inflammatory indices in forensic psychiatric patients receiving antipsychotic (AP) medication for more than five years, according to the type of AP. Methods: Thirty-five patients with psychotic disorders were classified into two groups based on the type of AP. Specifically: AP1, related to a lower risk, and AP2, related to an increased risk of weight gain (WG) and metabolic complications. Biochemical, hematological, anthropometric, blood pressure (BP), and medication data were retrieved from the individual medical files. Statistical analysis was performed with SPSS 23. Results: No significant differences in weight and glucose and cholesterol levels were observed, but patients taking AP2 more often needed drugs to control diabetes mellitus (DM), lipidemia, and cardiovascular disease (CVD). In those taking AP1, the mean HDL level decreased significantly over time (p < 0.05) and a higher proportion developed higher BP (52.9% of AP1 vs. 16.7% AP2). In the AP2 group the median level of C-reactive protein (CRP) (p < 0.001) and the white blood cell count (WBC) increased over the three years (p < 0.001). Conclusions: The proposed sub-classification of SGAs into AP1 and AP2, depending on their potential for metabolic and inflammatory effects, might facilitate study of their long-term side-effects but also help in personalized prevention or treatment measures to counteract these side-effects.
Churn Management in Telecommunications: Hybrid Approach Using Cluster Analysis and Decision Trees
Authors: Pejić Bach Mirjana , Pivar Jasmina , Jaković Božidar
Published: November 2021

The goal of the paper is to present the framework for combining clustering and classification for churn management in telecommunications. Considering the value of market segmentation, we propose a three-stage approach to explain and predict the churn in telecommunications separately for different market segments using cluster analysis and decision trees. In the first stage, a case study churn dataset is prepared for the analysis, consisting of demographics, usage of telecom services, contracts and billing, monetary value, and churn. In the second stage, k-means cluster analysis is used to identify market segments for which chi-square analysis is applied to detect the clusters with the highest churn ratio. In the third stage, the chi-squared automatic interaction detector (CHAID) decision tree algorithm is used to develop classification models to identify churn determinants at the clusters with the highest churn level. The contribution of this paper resides in the development of the structured approach to churn management using clustering and classification, which was tested on the churn dataset with a rich variable structure. The proposed approach is continuous since the results of market segmentation and rules for churn prediction can be fed back to the customer database to improve the efficacy of churn management.
Volatility and Depth in Commodity and FX Futures Markets
Authors: Aidov Alexandre , Lobanova Olesya
Published: November 2021

Prior theory suggests a positive relation between volatility and market depth, while past empirical research finds contrasting results. This paper examines the relation between the volatility and the limit order book depth in commodity and foreign exchange futures markets during a turbulent time using the generalized method of moments (GMM). Results indicate a negative relation between volatility and depth and suggest that the depth in the limit order book decreases as volatility increases. Findings help to understand how market participants provide liquidity in response to shifts in prices.
History, Current Situation and Challenges of Gold Mining in Ecuador’s Litoral Region
Authors: Mestanza-Ramón Carlos , Paz-Mena Selene , López-Paredes Carlos , Jimenez-Gutierrez Mirian , Herrera-Morales Greys , D’Orio Giovanni , Straface Salvatore
Published: November 2021

Gold mining in Ecuador has been present in the country since Inca times; over the years interest in the mineral has increased, leading to the creation of legislation to control the mining sector in a safe manner. The Litoral region consists of seven provinces, six of which have registered gold concessions; the most affected provinces are El Oro and Esmeraldas. The objective of this study was to analyze the historical and current situation of artisanal and industrial gold mining in the Litoral region of Ecuador. Different methodologies were used for the elaboration of this study, including bibliographic review, grey literature, field interviews and a validation of expert judgment. The main results indicate that El Oro and Esmeraldas are essentially the most conflictive areas in the region, as they have sometimes had to establish precautionary measures due to the risks caused by illegal mining. In addition, in both areas there is a great socioeconomic impact ranging from lack of opportunities, forgetfulness, migration, emigration, and violation of rights, among others. With respect to environmental impacts, the study highlights the contamination of water sources (which leads to a lack of drinking water for people), and damage to aquatic and terrestrial ecosystems. Finally, the study concludes that the authorities should control the mining sector more by implementing more laws and carrying out inspections to put an end to illegal gold mining, in order to improve the situation in the areas.
Subjectivity Analysis of Underground Incinerators: Focus on Academic and Industry Experts
Authors: Lee Jae-hyuck , Shin Kyung-hee , Park Jong-mun , Kim Choong-gon , Cho Kong-jang
Published: November 2021

Recently, incinerators have been shifted to underground complexes because of concerns regarding environmental pollution and declining land prices. In Korea, an underground waste incinerator has been built for the first time, with additional construction being expected in the near future. Therefore, a perception survey was conducted to acquire responses from South Korean experts regarding the impact of underground complex incinerators. The Q-methodology was used in the survey to examine various viewpoints. Academicians showed concerns regarding environmental effects of ground incinerators, and environmental and economic effects of underground complex incinerators; conversely, industrialists were concerned about civil complaints and administrative processing, indicating that the academicians were more concerned about scientific issues, whereas the industrialists were more concerned about democratic issues. Furthermore, both groups expressed concerns regarding land value and civil complaints of ground incinerators, safety issues and resultant social distrust of underground incinerators. The findings suggest that, to address the safety issues involving underground incinerator construction, governance by local experts is required for a holistic evaluation of environmental issues and economic feasibility of underground incinerators. To establish a link between science and democracy, measures for transparently sharing information are necessary.
Association between Rural Land Use Transition and Urban–Rural Integration Development: From 2009 to 2018 Based on County-Level Data in Shandong Province, China
Authors: Yang Zhiheng , Shen Nengneng , Qu Yanbo , Zhang Bailin
Published: November 2021

Integrated development in urban and rural areas has led to a new form of urban–rural interdependence, which promotes rural territorial functional evolution and land use changes. Rural land use transition, showing the synchronous development between cities and villages, is an important window through which to observe integrated development in urban and rural areas. We focus on uncovering the association between rural land use transition and urban–rural integration development (URID), put forward a dynamic relationship assumption between rural land use transformation and URID stages based on the transmission mechanism of urban–rural linkages, and undertake empirical analysis using the panel regression model with the data of county-level administrative units in Shandong Province, China. The results show that rural land use transition has maintained a close association with URID, and that the changes in cultivated land, forest land, and surface-water area are highly related to URID. There are different leading urban–rural linkages in rural areas around big-sized cities, mid-sized cities, and small-sized cities, which determine whether rural areas are in different URID stages of high, medium, or low levels. Further, rural areas can take different actions to promote URID at different stages through strengthening or introducing urban–rural linkages driven by economies of scale and deepening urbanization. This provides a reference for developing countries to formulate rural land use policies on achieving the goal of URID.
Construction Activity as an Element of Suburban Zone Development
Authors: Wysocka Donata , Biegańska Jadwiga , Grzelak-Kostulska Elżbieta
Published: November 2021

The dynamic process of suburbanisation in the countries of Central and Eastern Europe, including Poland, causes changes in the scale of the construction activity, mainly in the communes surrounding large cities. Although, in Poland, suburbanisation processes were initiated with the system transformation, and the first spatial planning law was adopted only in 1994. In addition, building permits were issued in an unplanned manner, regardless of future consequences. As a result, housing development, despite its high intensity in suburban zones, is dispersed and chaotic. The aim of this study is to juxtapose the construction activity with the guidelines governing this sphere contained in strategic and planning documents, with the example of the suburbs of Toruń. On the basis of the statistical data, and the planning and strategic documents at different levels, it is shown that construction activity, because of its interference in space, is indeed an important element shaping suburban zone development; there is a burning need for the appropriate, i.e., sustainable and long-term, planning of this process. This planning may be boosted by considering the potential development scenarios for the analysed communes belonging to the Toruń suburban area set out in this study.
Long-Term Variability in Ground Thermal State in Central Yakutia’s Tuymaada Valley
Authors: Varlamov Stepan Prokopievich , Skachkov Yuri Borisovich , Skryabin Pavel Nikolaevich
Published: November 2021

This paper presents the results of long-term temperature monitoring at the Yakutsk and Zeleny Lug stations, which are experimental sites, for the thermal state of valley permafrost landscapes under the conditions of modern climate warming. An analysis of the long-term data from meteorological stations in the region clearly showed one of the highest trends of increase in the mean annual air temperature in the north of Russia. Here, we established quantitative regularities in the long-term variability of the ground temperature at the bottom of the active layer and at zero amplitude. The dynamics of the ground temperature of the layer of zero amplitude during climate warming indicate the thermal stability of permafrost. The main regulating factor of the thermal state of grounds in permafrost landscapes is short-term fluctuations in the regime of snow accumulation. Active layer thickness is characterized by low interannual variability, weak climate warming responses, and insignificant trends. The results of studies of the thermal regime of soils can be extended to the same types of valley landscapes in the Lena River, and are a reliable basis for predicting heat transfer in natural and disturbed landscapes.
Assessing the Preference and Restorative Potential of Urban Park Blue Space
Authors: Luo Shixian , Xie Jing , Furuya Katsunori
Published: November 2021

Urban parks are essential parts of a city’s natural environment, and blue spaces of urban parks bring aesthetic and health benefits to people. However, the current blue spaces mainly focus on the marine environment or a giant water body scale at the urban or regional level. The urban park blue spaces (e.g., rivers, creeks, ponds) are relatively neglected. An experiment involving 10 different urban park blue spaces in Huanhuaxi park was conducted to assess urban park blue spaces’ aesthetic preference and restorative potential. The results indicated that (1) a water body with good water quality and natural visual form may be more attractive and have restorative potential; (2) blue spaces with high vegetation diversity are preferred, and artificial elements should be evaluated more carefully when added to the scene to avoid disharmony and conflict with the surrounding environment; (3) in practical design, the proportions of plants, buildings, topographical changes, and water should be coordinated to maintain the blue space’s landscape heterogeneity; (4) more leisure activities and interactions should be considered for better recovery; and (5) designers need to emphasize the balance of natural and man-made elements to enhance the visual quality of the water feature. This investigation is important for the management and development of leisure and natural resources in urban parks.
Degentrification? Different Aspects of Gentrification before and after the COVID-19 Pandemic
Authors: Han Soyoung , Bohannon Cermetrius Lynell , Kwon Yoonku
Published: November 2021

The purpose of this study is to explore the aspects of “gentrification” and “degentrification” other than economic factors. To this end, this study focused on the gentrification situations occurring before and after the COVID-19 pandemic in the Itaewon area, South Korea, by using semantic network analysis. We analyzed news articles on the gentrification phenomenon in the Itaewon area reported in South Korea. As a result, gentrification in the Itaewon area is divided into four stages. The first stage of gentrification (2010~2014) is initial stage of gentrification. Gentrification stage 2 (2015~2017) is the period of commercialization as a gentrification growth stage. The first stage of degentrification (2018~2019) is the maturation period of gentrification. The second stage of degentrification (2019~30 June 2020) is the period of the COVID-19 pandemic. The results confirm the existing theoretical frameworks while building a more nuanced definition through operationalizing gentrification and degentrification. As with the etymology of the term, the degentrification phenomenon can only be revealed when the gentrification phenomenon is prominently displayed. This study has an implication in that it tried to phenomenologically examine the specific phenomenon of the next stage of gentrification through the term “degentrification”.
Farmers’ Distress Index: An Approach for an Action Plan to Reduce Vulnerability in the Drylands of India
Authors: Reddy A. Amarender , Bhattacharya Anindita , Reddy S. Venku , Ricart Sandra
Published: November 2021

Farmer distress is a widely recognized problem in India induced by multiple causes ranging from climate variability to price volatility and the low risk-bearing ability of farmers. Tracking farmers’ distress in a localized context is a prerequisite for timely action to provide sustainable livelihood options. Therefore, a field survey was conducted with 640 dryland farmers of 10 sub-district units from two states in India with the aim to identify the major indicators based on seven dimensions of distress and to construct a multidimensional Farmers’ Distress Index (FDI) at the farmer and sub-district levels. The FDI was built with seven dimensions of distress: exposure to risk, adaptive capacity, sensitivity, mitigation and adaptation strategies, triggers, psychological factors, and impacts. The study developed a broad-based FDI which can be used as a planning tool that can address the causes of farmers’ distress and also evolve measures to tackle those causes. Based on the result, the study recommends a location-specific distress management package based on various dimensions of the FDI. The paper also suggests an upscaling strategy to identify and prioritize the highly distressed farmers as well as sub-district geographical units by tracking a few sets of variables.
The Interaction Relationship between Land Use Patterns and Socioeconomic Factors Based on Wavelet Analysis: A Case Study of the Black Soil Region of Northeast China
Authors: Wang Yue , Song Ge , Li Wenying
Published: November 2021

Analyzing the interaction between land use patterns (LUPs) and socioeconomic factors (SEFs) could provide a basis for regional land spatial planning and management decisions in the future. In this study, population, gross domestic product (GDP) and land use intensity were selected to explain the relationship between SEFs and LUPs. The study designed a new method of sample line acquisition for wavelet analysis, and identified the interaction grid scales of LUP changes with SEFs in 1991, 2005 and 2019 by using cross wavelet transform analysis (XWT). Wavelet transform coherent analysis (WTC) was used to reveal the interaction direction and impact strength between LUPs and SEFs. The results showed that: (1) There were two ranges of 2978–5008 m and 24,400–29,738 m in which the grid scales showing interaction between LUPs and SEFs (population, GDP and land use intensity) from 1991 to 2019 were overlapping. (2) The interaction direction between LUPs and SEFs from 1991 to 2019 was almost negative on all sample lines, while the interaction directions of the middle sample line of population and GDP from 1991 to 2019, the end sample line of GDP in 2019, and the start sample line of land use intensity in 1991 were positive. (3) Dry land, grassland and construction land were most affected by SEFs, followed by paddy fields, forest land and other land, and the least affected were water areas during 1991 to 2019. The impact of population and GDP on LUPs was reduced, while the impact of land use intensity on LUPs was increased from 1991 to 2019. Overall, population, GDP and land use intensity were the important SEFs in the changes of LUPs, and were important factors for social progress and economic development.
How Does the Effect Fade over Distance? An Inquiry into the Decay Pattern of Distance Effect on Property Values in the Case of Taipei, Taiwan
Authors: Chiang Hsieh Lin-Han
Published: November 2021

It is generally accepted that the perception of homeowners towards certain potential risks or amenities fades as distance from the risk or amenity increases. This study aims to illustrate the distance–decay pattern with an appropriate mathematical function. Distance–decay functions and parameters that yield the minimum residual sum of squares (RSS) for a given regression model are considered to be the optimal approximation for the pattern of decay. The effect of flood risk and mass rapid transit (MRT) accessibility on residential housing prices in Taipei, Taiwan, are used as examples to test the optimization process. The results indicate that the type of distance function affects both the significance and the magnitude of the regression coefficients. In the case of Taipei, concave functions provide better fits for both the flood risk and MRT accessibility. RSS reduction is up to 10% compared to the blank. Surprisingly, the impact range for the flood risk is found to be larger than that for MRT accessibility, which suggested that the impact range of perception for uncertain risks is larger than expected.
Factors Influencing Large Real Estate Companies’ Competitiveness: A Sustainable Development Perspective
Authors: Li Bo , Li Rita Yi Man , Wareewanich Thitinant
Published: November 2021

Strict policy control and real estate market downturn affects large-scale real estate enterprises performance. We surveyed large Chinese real estate enterprises and the internal factors that affect their competitiveness. Verified by the hierarchical regression and structural equation modelling approach, the results mainly show that profitability, capital ability, management and operation ability, human resource ability, brand name, and innovation ability play positive roles in the competitiveness of large real estate enterprises. Management and operation ability plays an intermediary role between human resources and the improvement of competitiveness. Real estate enterprises’ capital sources play an intermediary role between brand names and the improvement of competitiveness. Moreover, landbank area and quality and sales are three major factors that impact the competitiveness improvement of real estate enterprises, while the ability for marketing innovation and the payment collection of enterprises has a relatively small impact. All in all, this paper provides practical implications concerning factors that affect the competitiveness of large real estate enterprises. The findings are helpful to improve the sustainable development of real estate enterprises in the future. As research on factors that affect large-scale real estate enterprises is scarce, this study aims to fill this gap.
The Prospects for the Recognition of the International Legal Personality of Artificial Intelligence
Authors: Talimonchik Valentina Petrovna
Published: November 2021

This research aims to identify the prospects for recognizing the international legal personality of artificial intelligence, taking into account the practice of international organizations. The article describes a new idea based on the research of the existing practice of international organizations and the application of the author’s concept of international legal personality of legal entities, enabling the identification of the main directions of recognizing the international legal personality of artificial intelligence. Using the problematic-theoretical, formal-legal, logical, systemic-structural methods and methods of synthesis, analysis, and comparison, the author revealed two solutions to the problem of recognizing the international legal personality of artificial intelligence. The first way to resolve the problem is that states may grant the legal entity rights to artificial intelligence, gradually developing an international custom. The second way is that states may conclude that artificial intelligence will be granted a legal entity’s rights or sui generis by participating in discussions organized by various international organizations. The results of the study can be used for international unification.
Y/X-Chromosome-Bearing Sperm Shows Elevated Ratio in the Left but Not the Right Testes in Healthy Mice
Authors: Hu Chengqing , Shi Jiangcheng , Chi Yujing , Yang Jichun , Cui Qinghua
Published: November 2021

The sex chromosomes play central roles in determining the sex of almost all of the multicellular organisms. It is well known that meiosis in mammalian spermatogenesis produces ~50% Y- and ~50% X-chromosome-bearing sperm, a 1:1 ratio. Here we first reveal that the X-chromosome-encoded miRNAs show lower expression levels in the left testis than in the right testis in healthy mice using bioinformatics modeling of miRNA-sequencing data, suggesting that the Y:X ratio could be unbalanced between the left testis and the right testis. We further reveal that the Y:X ratio is significantly elevated in the left testis but balanced in the right testis using flow cytometry. This study represents the first time the biased Y:X ratio in the left testis but not in the right testis is revealed.
The Prebiotic Kitchen: A Guide to Composing Prebiotic Soup Recipes to Test Origins of Life Hypotheses
Authors: Vincent Lena , Colón-Santos Stephanie , Cleaves H. James , Baum David A. , Maurer Sarah E.
Published: November 2021

“Prebiotic soup” often features in discussions of origins of life research, both as a theoretical concept when discussing abiological pathways to modern biochemical building blocks and, more recently, as a feedstock in prebiotic chemistry experiments focused on discovering emergent, systems-level processes such as polymerization, encapsulation, and evolution. However, until now, little systematic analysis has gone into the design of well-justified prebiotic mixtures, which are needed to facilitate experimental replicability and comparison among researchers. This paper explores principles that should be considered in choosing chemical mixtures for prebiotic chemistry experiments by reviewing the natural environmental conditions that might have created such mixtures and then suggests reasonable guidelines for designing recipes. We discuss both “assembled” mixtures, which are made by mixing reagent grade chemicals, and “synthesized” mixtures, which are generated directly from diversity-generating primary prebiotic syntheses. We discuss different practical concerns including how to navigate the tremendous uncertainty in the chemistry of the early Earth and how to balance the desire for using prebiotically realistic mixtures with experimental tractability and replicability. Examples of two assembled mixtures, one based on materials likely delivered by carbonaceous meteorites and one based on spark discharge synthesis, are presented to illustrate these challenges. We explore alternative procedures for making synthesized mixtures using recursive chemical reaction systems whose outputs attempt to mimic atmospheric and geochemical synthesis. Other experimental conditions such as pH and ionic strength are also considered. We argue that developing a handful of standardized prebiotic recipes may facilitate coordination among researchers and enable the identification of the most promising mechanisms by which complex prebiotic mixtures were “tamed” during the origin of life to give rise to key living processes such as self-propagation, information processing, and adaptive evolution. We end by advocating for the development of a public prebiotic chemistry database containing experimental methods (including soup recipes), results, and analytical pipelines for analyzing complex prebiotic mixtures.
A Global Mutational Profile of SARS-CoV-2: A Systematic Review and Meta-Analysis of 368,316 COVID-19 Patients
Authors: Yusof Wardah , Irekeola Ahmad Adebayo , Wada Yusuf , Engku Abd Rahman Engku Nur Syafirah , Ahmed Naveed , Musa Nurfadhlina , Khalid Muhammad Fazli , Rahman Zaidah Abdul , Hassan Rosline , Yusof Nik Yusnoraini , Yean Yean Chan
Published: November 2021

Since its first detection in December 2019, more than 232 million cases of COVID-19, including 4.7 million deaths, have been reported by the WHO. The SARS-CoV-2 viral genomes have evolved rapidly worldwide, causing the emergence of new variants. This systematic review and meta-analysis was conducted to provide a global mutational profile of SARS-CoV-2 from December 2019 to October 2020. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA), and a study protocol was lodged with PROSPERO. Data from 62 eligible studies involving 368,316 SARS-CoV-2 genomes were analyzed. The mutational data analyzed showed most studies detected mutations in the Spike protein (n = 50), Nucleocapsid phosphoprotein (n = 34), ORF1ab gene (n = 29), 5′-UTR (n = 28) and ORF3a (n = 25). Under the random-effects model, pooled prevalence of SARS-CoV-2 variants was estimated at 95.1% (95% CI; 93.3–96.4%; I2 = 98.952%; p = 0.000) while subgroup meta-analysis by country showed majority of the studies were conducted ‘Worldwide’ (n = 10), followed by ‘Multiple countries’ (n = 6) and the USA (n = 5). The estimated prevalence indicated a need to continuously monitor the prevalence of new mutations due to their potential influence on disease severity, transmissibility and vaccine effectiveness.
LiCoO2/Graphite Cells with Localized High Concentration Carbonate Electrolytes for Higher Energy Density
Authors: Ma Xin , Zhang Peng , Zhao Huajun , Wang Qingrong , Zhang Guangzhao , Chi Shang-Sen , Liu Zhongbo , Qian Yunxian , Wang Jun , Wang Chaoyang , Deng Yonghong
Published: November 2021

Widening the working voltage of lithium-ion batteries is considered as an effective strategy to improve their energy density. However, the decomposition of conventional aprotic electrolytes at high voltage greatly impedes the success until the presence of high concentration electrolytes (HCEs) and the resultant localized HCEs (LHCEs). The unique solvated structure of HCEs/LHCEs endows the involved solvent with enhanced endurance toward high voltage while the LHCEs can simultaneously possess the decent viscosity for sufficient wettability to porous electrodes and separator. Nowadays, most LHCEs use LiFSI/LiTFSI as the salts and β-hydrofluoroethers as the counter solvents due to their good compatibility, yet the LHCE formula of cheap LiPF6 and high antioxidant α-hydrofluoroethers is seldom investigated. Here, we report a unique formula with 3 mol L−1 LiPF6 in mixed carbonate solvents and a counter solvent α-substituted fluorine compound (1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether). Compared to a conventional electrolyte, this formula enables dramatic improvement in the cycling performance of LiCoO2//graphite cells from approximately 150 cycles to 1000 cycles within the range of 2.9 to 4.5 V at 0.5 C. This work provides a new choice and scope to design functional LHCEs for high voltage systems.
Preliminary Study on the Simulation of a Radiation Damage Analysis of Biodegradable Polymers
Authors: Shim Ha-Eun , Yeon Yeong-Heum , Lim Dae-Hee , Nam You-Ree , Park Jin-Hyung , Lee Nam-Ho , Gwon Hui-Jeong
Published: November 2021

In this study, biodegradable poly(L-lactide-co-ε-caprolactone) (PLCL) and poly(L-co-d,l lactide) (PLDLA) were evaluated using Geant4 (G4EmStandardPhysics_option4) for damage simulation, in order to predict the safety of these biodegradable polymers against gamma ray sterilization. In the PLCL damage model, both chain scission and crosslinking reactions appear to occur at a radiation dose in the range 0–200 kGy, but the chain cleavage reaction is expected to be relatively dominant at high irradiation doses above 500 kGy. On the other hand, the PLDLA damage model predicted that the chain cleavage reaction would prevail at the total irradiation dose (25–500 kGy). To verify the simulation results, the physicochemical changes in the irradiated PLCL and PLDLA films were characterized by GPC (gel permeation chromatography), ATR-FTIR (attenuated total reflection Fourier transform infrared), and DSC (difference scanning calorimetry) analyses. The Geant4 simulation curve for the radiation-induced damage to the molecular weight was consistent with the experimentally obtained results. These results imply that the pre-simulation study can be useful for predicting the optimal irradiation dose and ensuring material safety, particularly for implanted biodegradable materials in radiation processing.
Energy Transfer Studies in Tb3+-Yb3+ Co-Doped Phosphate Glasses
Authors: Benrejeb Hadil , Soler-Carracedo Kevin , Lozano-Gorrín Antonio Diego , Hraiech Sana , Martin Inocencio Rafael
Published: November 2021

Detailed optical properties of Tb3+-Yb3+ co-doped phosphate glasses were performed based on their emission spectra and decay measurements. Under blue excitation of Tb3+ at 488 nm, the intensity of Yb3+ emissions gradually enhanced upon increasing the Yb3+ content until 1 mol% indicated an energy transfer from Tb3+ to Yb3+. Otherwise, under near infrared excitation of Yb3+ at 980 nm, these glasses exhibit intense green luminescence, which led to cooperative sensitization of the 5D4 level of Tb3+ ions. A cooperative energy transfer mechanism was proposed on the basis of the study on the influence of Yb3+ concentration on up-conversion emission intensity, as well as the dependence of this up-conversion intensity on near infrared excitation power. Moreover, the temporal evolution of the up-conversion emissions have been studied, which was in positive agreement with a theoretical model of cooperative up-conversion luminescence that showed a temporal emission curve with rise and decay times of the involved levels.
Possibilities to Use Physical Simulations When Studying the Distribution of Residual Stresses in the HAZ of Duplex Steels Welds
Authors: Moravec Jaromír , Bukovská Šárka , Švec Martin , Sobotka Jiří
Published: November 2021

Dual phase steels combine very good corrosion resistance with relatively high values of mechanical properties. In addition, they can maintain good plastic properties and toughness at both room temperature and lower temperatures as well. Despite all the advantages mentioned above, their utility properties can be reduced by technological processing, especially by the application of the temperature cycles. As a result, in the material remain residual stresses with local stress peaks, which are quite problematic especially during cyclic loading. Moreover, determining the level and especially the distribution of such residual stresses is very difficult for duplex steels both due to the structure duality and in light of the very small width of the heat-affected zone (HAZ). This is why the paper presents the possibilities of using physical simulations to study the effect of temperature cycles in residual stresses’ magnitude and distribution, where it is possible to study the HAZ in more detail as well as on a much larger sample width due to the utilization of special samples. In the thermal–mechanical simulator Gleeble 3500, temperature-stress cycles were applied to testing samples, generating stress fields with local peaks in the testing samples. In addition, the supplied steel X2CrMnNiN21-5-1 had different phase rations in the individual directions. Therefore, as the residual stresses were measured in several directions and at the same time, it was possible to safely confirm the suitability of the used measurement method. Moreover, the effect of the stress and strain on the change of partial phases’ ratios was observed. It has been experimentally confirmed that annealing temperatures of at least 700 °C are required to eliminate local stress peaks after welding. However, an annealing temperature of 550 °C seems to be optimal to maintain sufficient mechanical properties.
Multistage Tool Path Optimisation of Single-Point Incremental Forming Process
Authors: Yan Zhou , Hassanin Hany , El-Sayed Mahmoud Ahmed , Eldessouky Hossam Mohamed , Djuansjah JRP , A. Alsaleh Naser , Essa Khamis , Ahmadein Mahmoud
Published: November 2021

Single-point incremental forming (SPIF) is a flexible technology that can form a wide range of sheet metal products without the need for using punch and die sets. As a relatively cheap and die-less process, this technology is preferable for small and medium customised production. However, the SPIF technology has drawbacks, such as the geometrical inaccuracy and the thickness uniformity of the shaped part. This research aims to optimise the formed part geometric accuracy and reduce the processing time of a two-stage forming strategy of SPIF. Finite element analysis (FEA) was initially used and validated using experimental literature data. Furthermore, the design of experiments (DoE) statistical approach was used to optimise the proposed two-stage SPIF technique. The mass scaling technique was applied during the finite element analysis to minimise the computational time. The results showed that the step size during forming stage two significantly affected the geometrical accuracy of the part, whereas the forming depth during stage one was insignificant to the part quality. It was also revealed that the geometrical improvement had taken place along the base and the wall regions. However, the areas near the clamp system showed minor improvements. The optimised two-stage strategy successfully decreased both the geometrical inaccuracy and processing time. After optimisation, the average values of the geometrical deviation and forming time were reduced by 25% and 55.56%, respectively.
Treatment of Intrabony Defects with a Combination of Hyaluronic Acid and Deproteinized Porcine Bone Mineral
Authors: Božić Darko , Ćatović Ivan , Badovinac Ana , Musić Larisa , Par Matej , Sculean Anton
Published: November 2021

Background: this study evaluates the clinical outcomes of a novel approach in treating deep intrabony defects utilizing papilla preservation techniques with a combination of hyaluronic acid (HA) and deproteinized porcine bone mineral. Methods: 23 patients with 27 intrabony defects were treated with a combination of HA and deproteinized porcine bone mineral. Clinical attachment level (CAL), pocket probing depth (PPD), gingival recession (REC) were recorded at baseline and 6 months after the surgery. Results: At 6 months, there was a significant CAL gain of 3.65 ± 1.67 mm (p < 0.001) with a PPD reduction of 4.54 ± 1.65 mm (p < 0.001), which was associated with an increase in gingival recession (0.89 ± 0.59 mm, p < 0.001). The percentage of pocket resolution based on a PPD ≤4 mm was 92.6% and the failure rate based on a PPD of 5 mm was 7.4%. Conclusions: the present findings indicate that applying a combined HA and xenograft approach in deep intrabony defects provides clinically relevant CAL gains and PPD reductions compared to baseline values and is a valid new approach in treating intrabony defects.
Compression Behavior of Hybrid Tubes for Lightweight Steel Structures
Authors: Torres-Escobar Gregorio , Suárez-Bermejo Juan Carlos , Arenas José Manuel
Published: November 2021

This research shows the results of an experimental investigation carried out on the compression behavior of hybrid steel tubes formed by two concentric steel tubes and four different fillers of non-metallic material interposed between both tubes: polyurethane foam, polyurethane, epoxy and a cement-based mortar. The tests show that the incorporation of a resistant filler in the double tube allows it to improve its mechanical behavior by allowing a second load cycle. Furthermore, the strain energy absorbed during the two cycles led to the conclusion that the epoxy-filled tube absorbed more energy per unit of weight than the other resistant fillers.
Preliminary Studies on Rare Elements Addition and Effect on Oxidation Behaviour of Pack Cementation Coatings Deposited on Variety of Steels at High Temperature
Authors: Dudziak Tomasz , Rząd Ewa , Polczyk Tomasz , Jahns Katrin , Polkowski Wojciech , Polkowska Adelajda , Wójcicki Michal
Published: November 2021

The aim of the paper was to investigate the air oxidation behaviour of pack aluminised steels exposed at 650 °C for 1000 h in static natural air atmosphere. The pack coatings were doped by rare elements such as gadolinium (Gd), cerium oxide (CeO2), and lanthanum (La) in order to enhance the corrosion resistance and plasticity of the deposited layers. In this work, the following steels were used: 16M, T91, VM12, Super 304H, and finally SANICRO25. The results indicated a much higher corrosion resistance in the coated 16M, T91, and VM12 steels; the steels with a higher Cr content than 16 wt % Cr indicated a better behaviour in the uncoated state than in the coated state. However, the observed difference in mass gain between the uncoated and the coated austenitic steels was not enormous. Furthermore, the addition of RE elements to the coating showed some effect in terms of coating thicknesses and differences in the layer structures. The materials prior to testing and after the exposure were investigated using XRD, the SEM X-ray maps with an EDS instrument were used for particular samples to evaluate the phase identifications, element concentrations, microstructure, and chemical composition.
Evaluation of Scalable Synthesis Methods for Aluminum-Substituted Li7La3Zr2O12 Solid Electrolytes
Authors: Mann Markus , Küpers Michael , Häuschen Grit , Finsterbusch Martin , Fattakhova-Rohlfing Dina , Guillon Olivier
Published: November 2021

Solid electrolyte is the key component in all-solid-state batteries (ASBs). It is required in electrodes to enhance Li-conductivity and can be directly used as a separator. With its high Li-conductivity and chemical stability towards metallic lithium, lithium-stuffed garnet material Li7La3Zr2O12 (LLZO) is considered one of the most promising solid electrolyte materials for high-energy ceramic ASBs. However, in order to obtain high conductivities, rare-earth elements such as tantalum or niobium are used to stabilize the highly conductive cubic phase. This stabilization can also be obtained via high levels of aluminum, reducing the cost of LLZO but also reducing processability and the Li-conductivity. To find the sweet spot for a potential market introduction of garnet-based solid-state batteries, scalable and industrially usable syntheses of LLZO with high processability and good conductivity are indispensable. In this study, four different synthesis methods (solid-state reaction (SSR), solution-assisted solid-state reaction (SASSR), co-precipitation (CP), and spray-drying (SD)) were used and compared for the synthesis of aluminum-substituted LLZO (Al:LLZO, Li6.4Al0.2La3Zr2O12), focusing on electrochemical performance on the one hand and scalability and environmental footprint on the other hand. The synthesis was successful via all four methods, resulting in a Li-ion conductivity of 2.0–3.3 × 10−4 S/cm. By using wet-chemical synthesis methods, the calcination time could be reduced from two calcination steps for 20 h at 850 °C and 1000 °C to only 1 h at 1000 °C for the spray-drying method. We were able to scale the synthesis up to a kg-scale and show the potential of the different synthesis methods for mass production.
Polymer-Based Nanosystems—A Versatile Delivery Approach
Authors: Niculescu Adelina-Gabriela , Grumezescu Alexandru Mihai
Published: November 2021

Polymer-based nanoparticles of tailored size, morphology, and surface properties have attracted increasing attention as carriers for drugs, biomolecules, and genes. By protecting the payload from degradation and maintaining sustained and controlled release of the drug, polymeric nanoparticles can reduce drug clearance, increase their cargo’s stability and solubility, prolong its half-life, and ensure optimal concentration at the target site. The inherent immunomodulatory properties of specific polymer nanoparticles, coupled with their drug encapsulation ability, have raised particular interest in vaccine delivery. This paper aims to review current and emerging drug delivery applications of both branched and linear, natural, and synthetic polymer nanostructures, focusing on their role in vaccine development.
Undulated Step Structure on the (0001¯) Facet of Physical Vapor Transport-Grown 4H-SiC Crystals
Authors: Shinya Hiroaki , Nakano Masataka , Ohtani Noboru
Published: November 2021

The step structure on the (0001¯)C facet of 4H-SiC boules grown by the physical vapor transport growth method with different nitrogen doping concentrations was examined in various scales, using different types of microscopy, such as differential interference contrast optical microscopy (DICM) and atomic force microscopy (AFM). DICM observations unveiled characteristic macroscopic surface features of the facet dependent on the nitrogen doping concentration. AFM observations revealed the existence of step trains of half unit-cell height (0.5 nm) on the facet and found that their separation was undulated with a characteristic wavelength dependent on the nitrogen doping concentration; the higher the nitrogen concentration, the longer was the undulation wavelength of step separation. Based on these results, we discussed the origin and formation mechanism of the separation-undulated step structure observed on the (0001¯)C facet of nitrogen-doped 4H-SiC boules.