bluuebunny/crossref_metadata_2025 huggingface dataset:
Pure Laparoscopic Living Donor Hepatectomy With/Without Fluorescence-Assisted Technology and Conventional Open Procedure: A Retrospective Study in Mainland China
Authors: He Kang , Pan Yixiao , Wang Hai , Zhu Jianjun , Qiu Bijun , Luo Yi , Xia Qiang
Published: December 2021

Background: The application of laparoscopy in donor liver acquisition for living donor liver transplantation (LDLT) has become increasingly popular in the past decade. Indole cyanide green (ICG) fluorescence technique is a new adjuvant method in surgery. The purpose was to compare the safety and efficacy of laparoscopic and open surgery in living donor left lateral hepatectomy, and to evaluate the application of ICG in laparoscopy.

Methods: Donors received LDLT for left lateral lobe resection from November 2016 to November 2020 were selected and divided into pure laparoscopy donor hepatectomy (PLDH) group, fluorescence-assisted pure laparoscopy donor hepatectomy (FAPLDH) group and open donor hepatectomy (ODH) group. We compared perioperative data and prognosis of donors and recipients. Quality of life were evaluated by SF-36 questionnaires.

Results: The operation time of PLDH group (169.29 ± 26.68 min) was longer than FAPLDH group (154.34 ± 18.40 min) and ODH group (146.08 ± 25.39 min, p = 0.001). The blood loss was minimum in FAPLDH group (39.48 ± 10.46 mL), compared with PLDH group (52.44 ± 18.44 mL) and ODH group (108.80 ± 36.82 mL, p=0.001). The post-operative hospital stay was longer in PLDH group (5.30 ± 0.98 days) than FAPLDH group (4.81 ± 1.03 days) and ODH group (4.64 ± 1.20 days; p = 0.001). Quality of life of donors undergoing laparoscopic surgery was better.

Conclusion: Laparoscopic approaches for LDLT contribute to less blood loss, better cosmetic satisfaction. The fluorescence technique can further reduce bleeding and shorten operation time. In terms of quality of life, laparoscopic surgery is better than open surgery. Laparoscopy procedure for living-donor procurement with/without fluorescence-assist can be performed as safely as open surgery.
Comparison of Multi-Gene Testing Data Between Fresh and Formalin-Fixed Specimens From Core Needle Biopsy in Patients With NSCLC
Authors: Yao Zhi-Gang , Wei Zhi-Gang , Cheng Xian-Kui , Huang Guang-Hui , Zong Yuan-Yuan , Meng Min , Li Jia-Mei , Han Xiao-Ying , Xu Jia-Wen , Wang Jiao , Jing Hai-Yan , Li Wen-Hong , Cao Zhi-Xin , Ni Yang , Sun Xi-Chao , Yang Xia , Ye Xin
Published: December 2021

Purpose: Currently, formalin-fixed paraffin-embedded (FFPE) tissue specimens are the conventional material for gene testing for non-small cell lung cancer (NSCLC) patients. In our study, we aimed to develop a quick gene testing procedure using fresh core needle biopsy samples from NSCLC patients.

Methods: In total, 77 fresh NSCLC samples obtained from core needle biopsy were evaluated by frozen section examination. If the NSCLC diagnosis and adequate tumor cell counts were confirmed by histopathology, the fresh tissues were used to extract DNA and subsequent gene testing by ARMS-PCR. Meanwhile, the paired FFPE core needle biopsy samples from 30 NSCLC patients also underwent gene testing.

Results: In total, 77 fresh samples showed an EGFR mutation rate of 61.0%, higher than the levels in the Asian. Following a comparison of gene testing results with fresh tissues and paired FFPE tissues from the 30 patients, no significant difference in the DNA concentration extracted from fresh tissues and FFPE tissues was found. However, DNA purity was significantly higher in fresh tissues than that in FFPE tissues. Gene testing detected the same gene mutations in 93.3% of cases in fresh tissues and paired FFPE tissues. The gene testing procedure using fresh biopsy samples greatly shortens the waiting time of patients.

Conclusion: The multi-gene mutation testing using fresh core needle biopsy samples from NSCLC patients is a reasonable, achievable, and quick approach. Fresh tissues may serve as a potential alternative to FFPE tissues for gene testing in NSCLC patients.
Lempel-Ziv Parsing for Sequences of Blocks
Authors: Kosolobov Dmitry , Valenzuela Daniel
Published: December 2021

The Lempel-Ziv parsing (LZ77) is a widely popular construction lying at the heart of many compression algorithms. These algorithms usually treat the data as a sequence of bytes, i.e., blocks of fixed length 8. Another common option is to view the data as a sequence of bits. We investigate the following natural question: what is the relationship between the LZ77 parsings of the same data interpreted as a sequence of fixed-length blocks and as a sequence of bits (or other “elementary” letters)? In this paper, we prove that, for any integer b>1, the number z of phrases in the LZ77 parsing of a string of length n and the number zb of phrases in the LZ77 parsing of the same string in which blocks of length b are interpreted as separate letters (e.g., b=8 in case of bytes) are related as zb=O(bzlognz). The bound holds for both “overlapping” and “non-overlapping” versions of LZ77. Further, we establish a tight bound zb=O(bz) for the special case when each phrase in the LZ77 parsing of the string has a “phrase-aligned” earlier occurrence (an occurrence equal to the concatenation of consecutive phrases). The latter is an important particular case of parsing produced, for instance, by grammar-based compression methods.
Impact and Sustainability of Antibiotic Stewardship on Antibiotic Prescribing in Visceral Surgery
Authors: Gruber Magdalena Monika , Weber Alexandra , Jung Jette , Werner Jens , Draenert Rika
Published: December 2021

Background: Antibiotic stewardship (AS) ward rounds are a core element in clinical care for surgical patients. Therefore, we aimed to analyze the impact of surgical AS ward rounds on antibiotic prescribing, and the sustainability of the effect after the AS interventions are no longer provided. Methods: On four wards of the department of visceral surgery, we conducted two independent retrospective prescribing analyses (P1, P2) over three months each. During the study periods, the level of AS intervention differed for two of the four wards (ward rounds/no ward rounds). Results: AS ward rounds were associated with a decrease in overall antibiotic consumption (91.1 days of therapy (DOT)/100 patient days (PD) (P1), 70.4 DOT/100PD (P2)), and improved de-escalation rates of antibiotic therapy (W1/2: 25.7% (P1), 40.0% (P2), p = 0.030; W3: 15.4 (P1), 24.2 (P2), p = 0.081). On the ward where AS measures were no longer provided, overall antibiotic usage remained stable (71.3 DOT/100PD (P1), 74.4 DOT/100PD (P2)), showing the sustainability of AS measures. However, the application of last-resort compounds increased from 6.4 DOT/100PD to 12.1 DOT/100PD (oxazolidinones) and from 10.8 DOT/100PD to 13.2 DOT/100PD (carbapenems). Conclusions: Antibiotic consumption can be reduced without negatively affecting patient outcomes. However, achieving lasting positive changes in antibiotic prescribing habits remains a challenge.
Health and Budget Impact of Liquid-Biopsy-Based Comprehensive Genomic Profile (CGP) Testing in Tissue-Limited Advanced Non-Small Cell Lung Cancer (aNSCLC) Patients
Authors: Patel Yuti P. , Husereau Donald , Leighl Natasha B. , Melosky Barbara , Nam Julian
Published: December 2021

BACKGROUND AND OBJECTIVES: Molecular genetic testing using tissue biopsies can be challenging for patients due to unfavorable tumor sites, the invasive nature of a tissue biopsy, and the added time of booking a repeat biopsy (re-biopsy). Centers in Canada have found insufficient tissue rates to be approximately 10%, and even among successful biopsies, insufficient DNA in tissue samples is approximately 16%, triggering the lengthy process of re-biopsies. Using aNSCLC as an example, this study sought to characterize the health and budget impact of alternative liquid-biopsy(LBx)-based comprehensive genomic profile (CGP) testing in tissue-limited patients (TL-LBx-CGP) from a Canadian publicly funded healthcare perspective. MATERIAL AND METHODS: An economic model was developed to estimate the incremental cost and life-years gained as a population associated with adopting TL-LBx-CGP. The eligible patient population was modeled using a top-down epidemiological approach based on the published literature and expert clinician input. Treatment allocation was modeled based on biomarker prevalence in the published literature, and the availability of funded therapies. Costs included molecular testing, as well as drug, administrative, and supportive costs, and relevant health data included median overall survival and median progression-free survival data. RESULTS: Incorporation of TL-LBx-CGP demonstrated an overall impact of $14.7 million with 168 life-years gained to the Canadian publicly funded healthcare system in the 3-year time horizon.
UAV-Enabled Mobile Edge-Computing for IoT Based on AI: A Comprehensive Review
Authors: Yazid Yassine , Ez-Zazi Imad , Guerrero-González Antonio , El Oualkadi Ahmed , Arioua Mounir
Published: December 2021

Unmanned aerial vehicles (UAVs) are becoming integrated into a wide range of modern IoT applications. The growing number of networked IoT devices generates a large amount of data. However, processing and memorizing this massive volume of data at local nodes have been deemed critical challenges, especially when using artificial intelligence (AI) systems to extract and exploit valuable information. In this context, mobile edge computing (MEC) has emerged as a way to bring cloud computing (CC) processes within reach of users, to address computation-intensive offloading and latency issues. This paper provides a comprehensive review of the most relevant research works related to UAV technology applications in terms of enabled or assisted MEC architectures. It details the utility of UAV-enabled MEC architecture regarding emerging IoT applications and the role of both deep learning (DL) and machine learning (ML) in meeting various limitations related to latency, task offloading, energy demand, and security. Furthermore, throughout this article, the reader gains an insight into the future of UAV-enabled MEC, the advantages and the critical challenges to be tackled when using AI.
Topological Invariants of Vapor–Liquid, Vapor–Liquid–Liquid and Liquid–Liquid Phase Diagrams
Authors: Frolkova Anastasia V.
Published: December 2021

The study of topological invariants of phase diagrams allows for the development of a qualitative theory of the processes being researched. Studies of the properties of objects in the same equivalence class may be carried out with the aim of predicting the properties of unexplored objects from this class, or predicting the behavior of a whole system. This paper describes a number of topological invariants in vapor–liquid, vapor–liquid–liquid and liquid–liquid equilibrium diagrams. The properties of some invariants are studied and illustrated. It is shown that the invariant of a diagram with a miscibility gap can be used to distinguish equivalence classes of phase diagrams, and that the balance equation of the singular-point indices, based on the Euler characteristic, may be used to analyze the binodal-surface structure of a quaternary system.
Electrostatic Zipping Actuators—Analysis of the Pull-In Effect Depending on the Geometry Parameters
Authors: Szkopek Jacek , Redlarski Grzegorz , Żak Arkadiusz
Published: December 2021

Continuous work on a new generation of actuators, referred to as artificial muscles, resulted in the initiation of work on electrostatic zipping actuators, the concept of which is derived from micro electro-mechanical devices. Despite partial knowledge of their basic operating parameters, a question remains whether electrostatic zipping actuators are able to meet the expectations in the context of generated forces and control possibilities. In order to get closer to the answer to this question, the authors of this work created a solution method using FEM, which allowed them to conduct a series of concentric contraction tests of the desired solution. In addition to the basic features of the actuators tested, such as their length, thickness and width, for the first time the size of the weld surface, to which the loading force was applied, was taken into account. The results of the investigations show the possibility of adjusting the supply voltage range to the application requirements, but most importantly, they present the variability of the pull-in strain parameter. In extreme configurations, its value increases from ~10% to ~26%. The results obtained emphasize the need for further analysis of electrostatic zipping actuators using FEM. It will make it possible to precisely define the characteristics of this technology as well as its limits. These activities will provide the ultimate answer to the potential of electrostatic zipping actuators as artificial muscles.
Genophenotypic Factors and Pharmacogenomics in Adverse Drug Reactions
Authors: Cacabelos Ramón , Naidoo Vinogran , Corzo Lola , Cacabelos Natalia , Carril Juan C.
Published: December 2021

Adverse drug reactions (ADRs) rank as one of the top 10 leading causes of death and illness in developed countries. ADRs show differential features depending upon genotype, age, sex, race, pathology, drug category, route of administration, and drug–drug interactions. Pharmacogenomics (PGx) provides the physician effective clues for optimizing drug efficacy and safety in major problems of health such as cardiovascular disease and associated disorders, cancer and brain disorders. Important aspects to be considered are also the impact of immunopharmacogenomics in cutaneous ADRs as well as the influence of genomic factors associated with COVID-19 and vaccination strategies. Major limitations for the routine use of PGx procedures for ADRs prevention are the lack of education and training in physicians and pharmacists, poor characterization of drug-related PGx, unspecific biomarkers of drug efficacy and toxicity, cost-effectiveness, administrative problems in health organizations, and insufficient regulation for the generalized use of PGx in the clinical setting. The implementation of PGx requires: (i) education of physicians and all other parties involved in the use and benefits of PGx; (ii) prospective studies to demonstrate the benefits of PGx genotyping; (iii) standardization of PGx procedures and development of clinical guidelines; (iv) NGS and microarrays to cover genes with high PGx potential; and (v) new regulations for PGx-related drug development and PGx drug labelling.
New Insights in the Involvement of the Endocannabinoid System and Natural Cannabinoids in Nicotine Dependence
Authors: Saravia Rocio , Ten-Blanco Marc , Pereda-Pérez Inmaculada , Berrendero Fernando
Published: December 2021

Nicotine, the main psychoactive component in tobacco smoke, plays a major role in tobacco addiction, producing a high morbidity and mortality in the world. A great amount of research has been developed to elucidate the neural pathways and neurotransmitter systems involved in such a complex addictive behavior. The endocannabinoid system, which has been reported to participate in the addictive properties of most of the prototypical drugs of abuse, is also implicated in nicotine dependence. This review summarizes and updates the main behavioral and biochemical data involving the endocannabinoid system in the rewarding properties of nicotine as well as in nicotine withdrawal and relapse to nicotine-seeking behavior. Promising results from preclinical studies suggest that manipulation of the endocannabinoid system could be a potential therapeutic strategy for treating nicotine addiction.
Method Categorization of Stem Cell Therapy for Degenerative Osteoarthritis of the Knee: A Review
Authors: Lee Jae Sun , Shim Dong Woo , Kang Kyung-Yil , Chae Dong-Sik , Lee Woo-Suk
Published: December 2021

Current clinical applications of mesenchymal stem cell therapy for osteoarthritis lack consistency because there are no established criteria for clinical processes. We aimed to systematically organize stem cell treatment methods by reviewing the literature. The treatment methods used in 27 clinical trials were examined and reviewed. The clinical processes were separated into seven categories: cell donor, cell source, cell preparation, delivery methods, lesion preparation, concomitant procedures, and evaluation. Stem cell donors were sub-classified as autologous and allogeneic, and stem cell sources included bone marrow, adipose tissue, peripheral blood, synovium, placenta, and umbilical cord. Mesenchymal stem cells can be prepared by the expansion or isolation process and attached directly to cartilage defects using matrices or injected into joints under arthroscopic observation. The lesion preparation category can be divided into three subcategories: chondroplasty, microfracture, and subchondral drilling. The concomitant procedure category describes adjuvant surgery, such as high tibial osteotomy. Classification codes were assigned for each subcategory to provide a useful and convenient method for organizing documents associated with stem cell treatment. This classification system will help researchers choose more unified treatment methods, which will facilitate the efficient comparison and verification of future clinical outcomes of stem cell therapy for osteoarthritis.
Protection of Cholinergic Neurons against Zinc Toxicity by Glial Cells in Thiamine-Deficient Media
Authors: Gul-Hinc Sylwia , Michno Anna , Zyśk Marlena , Szutowicz Andrzej , Jankowska-Kulawy Agnieszka , Ronowska Anna
Published: December 2021

Brain pathologies evoked by thiamine deficiency can be aggravated by mild zinc excess. Cholinergic neurons are the most susceptible to such cytotoxic signals. Sub-toxic zinc excess aggravates the injury of neuronal SN56 cholinergic cells under mild thiamine deficiency. The excessive cell loss is caused by Zn interference with acetyl-CoA metabolism. The aim of this work was to investigate whether and how astroglial C6 cells alleviated the neurotoxicity of Zn to cultured SN56 cells in thiamine-deficient media. Low Zn concentrations did not affect astroglial C6 and primary glial cell viability in thiamine-deficient conditions. Additionally, parameters of energy metabolism were not significantly changed. Amprolium (a competitive inhibitor of thiamine uptake) augmented thiamine pyrophosphate deficits in cells, while co-treatment with Zn enhanced the toxic effect on acetyl-CoA metabolism. SN56 cholinergic neuronal cells were more susceptible to these combined insults than C6 and primary glial cells, which affected pyruvate dehydrogenase activity and the acetyl-CoA level. A co-culture of SN56 neurons with astroglial cells in thiamine-deficient medium eliminated Zn-evoked neuronal loss. These data indicate that astroglial cells protect neurons against Zn and thiamine deficiency neurotoxicity by preserving the acetyl-CoA level.
Use of Zebrafish Models to Boost Research in Rare Genetic Diseases
Authors: Crouzier Lucie , Richard Elodie , Sourbron Jo , Lagae Lieven , Maurice Tangui , Delprat Benjamin
Published: December 2021

Rare genetic diseases are a group of pathologies with often unmet clinical needs. Even if rare by a single genetic disease (from 1/2000 to 1/more than 1,000,000), the total number of patients concerned account for approximatively 400 million peoples worldwide. Finding treatments remains challenging due to the complexity of these diseases, the small number of patients and the challenge in conducting clinical trials. Therefore, innovative preclinical research strategies are required. The zebrafish has emerged as a powerful animal model for investigating rare diseases. Zebrafish combines conserved vertebrate characteristics with high rate of breeding, limited housing requirements and low costs. More than 84% of human genes responsible for diseases present an orthologue, suggesting that the majority of genetic diseases could be modelized in zebrafish. In this review, we emphasize the unique advantages of zebrafish models over other in vivo models, particularly underlining the high throughput phenotypic capacity for therapeutic screening. We briefly introduce how the generation of zebrafish transgenic lines by gene-modulating technologies can be used to model rare genetic diseases. Then, we describe how zebrafish could be phenotyped using state-of-the-art technologies. Two prototypic examples of rare diseases illustrate how zebrafish models could play a critical role in deciphering the underlying mechanisms of rare genetic diseases and their use to identify innovative therapeutic solutions.
Plant Proteomic Research 4.0: Frontiers in Stress Resilience
Authors: Chen Sixue , Komatsu Setsuko
Published: December 2021

Large-scale high-throughput multi-omics technologies are indispensable components of systems biology in terms of discovering and defining parts of the system [...]
Plasma Sphingosine-1-Phosphate Levels Are Associated with Progression of Estrogen Receptor-Positive Breast Cancer
Authors: Ikarashi Mayuko , Tsuchida Junko , Nagahashi Masayuki , Takeuchi Shiho , Moro Kazuki , Toshikawa Chie , Abe Shun , Ichikawa Hiroshi , Shimada Yoshifumi , Sakata Jun , Koyama Yu , Sato Nobuaki , Hait Nitai C. , Ling Yiwei , Okuda Shujiro , Takabe Kazuaki , Wakai Toshifumi
Published: December 2021

Although numerous experiments revealed an essential role of a lipid mediator, sphingosine-1-phosphate (S1P), in breast cancer (BC) progression, the clinical significance of S1P remains unclear due to the difficulty of measuring lipids in patients. The aim of this study was to determine the plasma concentration of S1P in estrogen receptor (ER)-positive BC patients, as well as to investigate its clinical significance. We further explored the possibility of a treatment strategy targeting S1P in ER-positive BC patients by examining the effect of FTY720, a functional antagonist of S1P receptors, on hormone therapy-resistant cells. Plasma S1P levels were significantly higher in patients negative for progesterone receptor (PgR) expression than in those positive for expression (p = 0.003). Plasma S1P levels were also significantly higher in patients with larger tumor size (p = 0.012), lymph node metastasis (p = 0.014), and advanced cancer stage (p = 0.003), suggesting that higher levels of plasma S1P are associated with cancer progression. FTY720 suppressed the viability of not only wildtype MCF-7 cells, but also hormone therapy-resistant MCF-7 cells. Targeting S1P signaling in ER-positive BC appears to be a possible new treatment strategy, even for hormone therapy-resistant patients.
Fabrication and Characterization of Steel-Base Metal Matrix Composites Reinforced by Yttria Nanoparticles through Friction Stir Processing
Authors: Mahmoud Essam R. I. , Almohamadi Hamad , Aljabri Abdulrahman , Khan Sohaib Z. , Saquib Ahmad N. , Farhan Mohammed , Elkotb Mohammed Abdel-Ghani
Published: December 2021

Friction Stir Processing (FSP) was used to fabricate metal matrix composite, based on steel and reinforced with nano-sized yttrium oxide powder. The powder was packed in a narrow longitudinal groove of 2 mm depth and 1 mm width cut in the steel plate’s rear surface. Different rotation speeds of 500–1500 rpm were used, at a fixed traveling speed of 50 mm·min−1. Single-pass and two passes, with the same conditions, were applied. The direction of the second pass was opposite to that of the first pass. After the first pass, complete nugget zones were obtained when the rotation speeds were more than 700 rpm with some particles agglomeration. The added particles showed as narrow elliptical bands, with a band pitch equal to the rotation speed over traveling speed. Performing the second FSP pass in the opposite direction resulted in better particles distributions. Almost defect-free composite materials, with homogenously distributed yttria nano-sized particles, were obtained after two passes when rotation speeds more than 700 rpm were used. The resulting steel matrix grains were refined from ~60 μm of the base metal to less than 3 μm of the processed nugget zone matrix. The hardness and the tensile strength of the fabricated materials improved almost two-fold over the base metal. Uniform microhardness values within the nugget areas were observed at higher rotational speeds. The ductility and toughness of the fabricated composites were reduced compared to the base metal.
Nonlinear Models of Thermo-Viscoelastic Materials
Authors: Giorgi Claudio , Morro Angelo
Published: December 2021

The paper develops a general scheme for viscoelastic materials, where the constitutive properties are described by means of measures of strain, stress, heat flux, and their time derivatives. The constitutive functions are required to be consistent with the second law of thermodynamics. Indeed, a new view is associated with the second law: the non-negative expression of the entropy production is set equal to a further constitutive function. The introduction of the entropy production as a constitutive function allows for a much wider range of models. Within this range, a scheme to obtain nonlinear models of thermo-viscoelastic materials subject to large deformations is established. Notably, the Kelvin–Voigt, Maxwell, Burgers, and Oldroyd-B viscoelastic models, along with the Maxwell–Cattaneo heat conduction, are obtained as special cases. The scheme allows also for modelling the visco-plastic materials, such as the Prandtl–Reuss work-hardening function and the Bingham–Norton fluid.
Structural Lattice Topology and Material Optimization for Battery Protection in Electric Vehicles Subjected to Ground Impact Using Artificial Neural Networks and Genetic Algorithms
Authors: Nasrullah Alvian Iqbal Hanif , Puji Santosa Sigit , Widagdo Djarot , Arifurrahman Faizal
Published: December 2021

A critical external interference that often appears to pose a safety issue in rechargeable energy storage systems (RESS) for electric vehicles (EV) is ground impact due to stone impingement. This study aims to propose the new concept of the sandwich for structural battery protection using a lattice structure configuration for electric vehicle applications. The protective geometry consists of two layers of a twisted-octet lattice structure. The appropriate lattice structure was selected through topology and material optimization using an artificial neural network (ANN), genetic algorithms (GA), and multi-objective optimization with technique for order of preference by similarity to ideal solution (TOPSIS) methods. The optimization variables are the lattice structure relative density, ρ¯, angle, θ, and strength of the materials, σy. Numerical simulations were used to model the dynamic impact loading on the structures due to a conical stone mass of 0.77 kg traveling at 162 km/h. The two-layer lattice structure configuration appears to be suitable for the purposes of RESS protection. The optimum configuration for battery protection is a lattice structure with an angle of 66°, relative density of 0.8, and yield strength of 41 MPa. This optimum configuration can satisfy the safety threshold of battery-shortening deformation. Therefore, the proposed lattice structure configuration can potentially be implemented for electric vehicle applications to protect the battery from ground impact.
CO2 Adsorption on PtCu Sub-Nanoclusters Deposited on Pyridinic N-Doped Graphene: A DFT Investigation
Authors: Montejo-Alvaro Fernando , González-Quijano Diego , Valmont-Pineda Jorge A. , Rojas-Chávez Hugo , Juárez-García José M. , Medina Dora I. , Cruz-Martínez Heriberto
Published: December 2021

To reduce the CO2 concentration in the atmosphere, its conversion to different value-added chemicals plays a very important role. Nevertheless, the stable nature of this molecule limits its conversion. Therefore, the design of highly efficient and selective catalysts for the conversion of CO2 to value-added chemicals is required. Hence, in this work, the CO2 adsorption on Pt4-xCux (x = 0–4) sub-nanoclusters deposited on pyridinic N-doped graphene (PNG) was studied using the density functional theory. First, the stability of Pt4-xCux (x = 0–4) sub-nanoclusters supported on PNG was analyzed. Subsequently, the CO2 adsorption on Pt4-xCux (x = 0–4) sub-nanoclusters deposited on PNG was computed. According to the binding energies of the Pt4-xCux (x = 0–4) sub-nanoclusters on PNG, it was observed that PNG is a good material to stabilize the Pt4-xCux (x = 0–4) sub-nanoclusters. In addition, charge transfer occurred from Pt4-xCux (x = 0–4) sub-nanoclusters to the PNG. When the CO2 molecule was adsorbed on the Pt4-xCux (x = 0–4) sub-nanoclusters supported on the PNG, the CO2 underwent a bond length elongation and variations in what bending angle is concerned. In addition, the charge transfer from Pt4-xCux (x = 0–4) sub-nanoclusters supported on PNG to the CO2 molecule was observed, which suggests the activation of the CO2 molecule. These results proved that Pt4-xCux (x = 0–4) sub-nanoclusters supported on PNG are adequate candidates for CO2 adsorption and activation.
Influence of Semi-Random and Regular Shot Peening on Selected Surface Layer Properties of Aluminum Alloy
Authors: Matuszak Jakub , Zaleski Kazimierz , Skoczylas Agnieszka , Ciecieląg Krzysztof , Kęcik Krzysztof
Published: December 2021

This paper attempts to compare regular shot peening (RSP) and semi-random shot peening (SRSP). A characteristic of the first method is that the peening elements hit the treated surface in sequence, with a regular distance maintained between the dimples. The other method (SRSP) is a controlled modification of the shot-peening process, which is random by nature. The shot-peening method used in this study differs from conventional shot peening (shot blasting and vibratory shot peening) in that it allows controlled and repeatable determination of the configuration and distribution of impacts exerted by the peening element on the workpiece surface, which makes the process more repeatable and easier to model. Specimens of EN-AW 7075 aluminum alloy were used for testing. The following variables were used in the experiments: ball diameter, impact energy, and distance between the dimples. Microhardness distribution in the surface layer, 2D surface roughness, and surface topography were analyzed. FEM simulations of the residual stress distribution in the surface layer were performed. It has been found that regular shot peening results in reduced surface roughness, while semi-random shot peening leads to higher surface layer hardening.
Traditional Artificial Neural Networks Versus Deep Learning in Optimization of Material Aspects of 3D Printing
Authors: Rojek Izabela , Mikołajewski Dariusz , Kotlarz Piotr , Tyburek Krzysztof , Kopowski Jakub , Dostatni Ewa
Published: December 2021

3D printing of assistive devices requires optimization of material selection, raw materials formulas, and complex printing processes that have to balance a high number of variable but highly correlated variables. The performance of patient-specific 3D printed solutions is still limited by both the increasing number of available materials with different properties (including multi-material printing) and the large number of process features that need to be optimized. The main purpose of this study is to compare the optimization of 3D printing properties toward the maximum tensile force of an exoskeleton sample based on two different approaches: traditional artificial neural networks (ANNs) and a deep learning (DL) approach based on convolutional neural networks (CNNs). Compared with the results from the traditional ANN approach, optimization based on DL decreased the speed of the calculations by up to 1.5 times with the same print quality, improved the quality, decreased the MSE, and a set of printing parameters not previously determined by trial and error was also identified. The above-mentioned results show that DL is an effective tool with significant potential for wide application in the planning and optimization of material properties in the 3D printing process. Further research is needed to apply low-cost but more computationally efficient solutions to multi-tasking and multi-material additive manufacturing.
Growth of Pseudomorphic GeSn at Low Pressure with Sn Composition of 16.7%
Authors: Grant Joshua , Abernathy Grey , Olorunsola Oluwatobi , Ojo Solomon , Amoah Sylvester , Wanglia Emmanuel , Saha Samir K. , Sabbar Abbas , Du Wei , Alher Murtadha , Li Bao-Hua , Yu Shui-Qing
Published: December 2021

Group-IV alloy GeSn holds great promise for the high-performance optoelectronic devices that can be monolithically integrated on Si for near- and mid-infrared applications. Growth of GeSn using chemical vapor deposition technique with various Sn and Ge precursors has been investigated worldwide. To achieve relatively high Sn incorporation, the use of higher pressure and/or higher order Ge hydrides precursors were reported. In this work, we successfully demonstrated the growth of high-quality GeSn with Sn composition of 16.7% at low pressure of 12 Torr. The alloy was grown using the commercially available GeH4 and SnCl4 precursors via a chemical vapor deposition reactor. Material and optical characterizations were performed to confirm the Sn incorporation and to study the optical properties. The demonstrated growth results reveal a low-pressure growth window to achieve high-quality and high Sn alloys for future device applications.
Hyperelastic Material Parameter Determination and Numerical Study of TPU and PDMS Dampers
Authors: Emminger Carina , Çakmak Umut D. , Preuer Rene , Graz Ingrid , Major Zoltán
Published: December 2021

Dampers provide safety by controlling unwanted motion that is caused due to the conversion of mechanical work into another form of energy (e.g., heat). State-of-the-art materials are elastomers and include thermoplastic elastomers. For the polymer-appropriate replacement of multi-component shock absorbers comprising mounts, rods, hydraulic fluids, pneumatic devices, or electro-magnetic devices, among others, in-depth insights into the mechanical characteristics of damper materials are required. The ultimate objective is to reduce complexity by utilizing inherent material damping rather than structural (multi-component) damping properties. The objective of this work was to compare the damping behavior of different elastomeric materials including thermoplastic poly(urethane) (TPU) and silicone rubber blends (mixtures of different poly(dimethylsiloxane) (PDMS)). Therefore, the materials were hyper- and viscoelastic characterized, a finite element calculation of a ball drop test was performed, and for validation, the rebound resilience was measured experimentally. The results revealed that the material parameter determination methodology is reliable, and the data that were applied for simulation led to realistic predictions. Interestingly, the rebound resilience of the mixture of soft and hard PDMS (50:50) wt% was the highest, and the lowest values were measured for TPU.
Quartzite Mining Waste: Diagnosis of ASR Alkali-Silica Reaction in Mortars and Portland Cement Concrete
Authors: Francklin Ivan , Ribeiro Rogério Pinto , Corrêa Fernando Augusto
Published: December 2021

The main objective was to determine the deleterious potential of quartzite mining tailings subjected to different ASR alkali–silica reaction tests. The studies included petrographic analysis, chemical analysis of cements, expansion tests in mortar bars and concrete prisms, and microstructural analysis. Petrographic analysis of quartzites indicated high percentages of deformed quartz (95%), and were classified as potentially reactive. Two types of HES high early strength cement with alkaline equivalents of 0.749% and 0.61%, respectively, were selected. Of the 8 samples analyzed by the accelerated method in mortars, only 2 quartzite samples and 1 diabasium sample indicated potentially reactive behavior. The accelerated and long-term methods in concrete prisms proved to be effective and were consistent with the deleterious potential of the samples. All analyzed samples were diagnosed with the ASR gel. In the microstructural analysis, in addition to the ASR products, other expansive products of late ettringite were detected. Reaction mitigation methods are proposed so that quartzite waste can be used as an alternative aggregate in concrete, and thus contribute to the reduction of mine tailings and, consequently, reduce the negative environmental impact from mining.
Investigation of the Fatigue Stress of Orthotropic Steel Decks Based on an Arch Bridge with the Application of the Arlequin Method
Authors: Cheng Cheng , Xie Xu , Yu Wentao
Published: December 2021

Orthotropic steel decks are widely used in the construction of steel bridges. Although there are many fatigue-evaluation methods stipulated by codes, unexpected fatigue cracks are still detected in some bridges. To justify whether the local finite element model commonly used in fatigue investigations on orthotropic decks can correctly instruct engineering practices, the Arlequin framework is applied in this paper to determine the full fatigue stress under traffic loads. The convergence on and validity of this application for orthotropic decks are checked. Results show that the Arlequin model for deck-fatigue analysis established in this paper tends to be an efficient method for complete fatigue stress acquisition, whereby the vulnerable sites of orthotropic steel decks under traffic loads are defined. Vehicles near the flexible components, such as hangers or cables, can have adverse effects on the fatigue durability of decks. Additionally, the total number of vehicles and their arrangement concentration also affect fatigue performance. Complex traffic conditions cannot be fully loaded in local models. Regardless of the gross bridge mechanics and deck deformation, the fatigue stress range is underestimated by about 30–40%. Such a difference in fatigue assessment seems to explain the premature cracks observed in orthotropic steel decks.
Development and Vertical Tests of CEPC 650-MHz Single-Cell Cavities with High Gradient
Authors: Jin Song , Sha Peng , Pan Weimin , Zhai Jiyuan , Mi Zhenghui , He Feisi , Dong Chao , Ye Lingxi , He Xiangcong
Published: December 2021

A circular electron positron collider (CEPC) will adopt hundreds of 650-MHz superconducting cavities with high quality factor (Q) and accelerating gradient (Eacc). Two 650-MHz single-cell cavities made of fine-grain niobium were first treated via buffered chemical polishing (BCP), which was easy and convenient. However, the vertical test results could not meet the specification of the CEPC (4 × 1010 at 22 MV/m). Therefore, electro-polishing (EP) of 650-MHz single-cell cavities was conducted, which was complicated but remarkably effective. Both 650-MHz single-cell cavities achieved state-of-the-art gradients of 35 MV/m after the EP process, which is extremely high for large elliptical cavities (frequency < 1 GHz). One cavity achieved an intrinsic quality factor (Q0) of 4.5 × 1010 at 22.0 MV/m, which was higher than the CEPC spec. The other cavity obtained a lower Q0 of 3.4 × 1010 at 22.0 MV/m, which may have resulted from the cancellation of high-temperature annealing.
Ultrahigh Temperature Flash Sintering of Binder-Less Tungsten Carbide within 6 s
Authors: Deng Huaijiu , Biesuz Mattia , Vilémová Monika , Kermani Milad , Veverka Jakub , Tyrpekl Václav , Hu Chunfeng , Grasso Salvatore
Published: December 2021

We report on an ultrarapid (6 s) consolidation of binder-less WC using a novel Ultrahigh temperature Flash Sintering (UFS) approach. The UFS technique bridges the gap between electric resistance sintering (≪1 s) and flash spark plasma sintering (20–60 s). Compared to the well-established spark plasma sintering, the proposed approach results in improved energy efficiency with massive energy and time savings while maintaining a comparable relative density (94.6%) and Vickers hardness of 2124 HV. The novelty of this work relies on (i) multiple steps current discharge profile to suit the rapid change of electrical conductivity experienced by the sintering powder, (ii) upgraded low thermal inertia CFC dies and (iii) ultra-high consolidation temperature approaching 2750 °C. Compared to SPS process, the UFS process is highly energy efficient (≈200 times faster and it consumes ≈95% less energy) and it holds the promise of energy efficient and ultrafast consolidation of several conductive refractory compounds.
Corrosion Behavior in Volcanic Soils: In Search of Candidate Materials for Thermoelectric Devices
Authors: Berlanga-Labari Carlos , Catalán Leyre , Palacio José F. , Pérez Gurutze , Astrain David
Published: December 2021

Thermoelectric generators have emerged as an excellent solution for the energy supply of volcanic monitoring stations due to their compactness and continuous power generation. Nevertheless, in order to become a completely viable solution, it is necessary to ensure that their materials are able to resist in the acidic environment characteristic of volcanoes. Hence, the main objective of this work is to study the resistance to corrosion of six different metallic materials that are candidates for use in the heat exchangers. For this purpose, the metal probes have been buried for one year in the soil of the Teide volcano (Spain) and their corrosion behavior has been evaluated by using different techniques (OM, SEM, and XRD). The results have shown excessive corrosion damage to the copper, brass, and galvanized steel tubes. After evaluating the corrosion behavior and thermoelectric performance, AISI 304 and AISI 316 stainless steels are proposed for use as heat exchangers in thermoelectric devices in volcanic environments.
Effect of Al Concentration on Microstructure and Properties of AlNbTiZr Medium-Entropy Alloy Coatings
Authors: Xin Hongyang , Yang Jijun , Mao Jianjun , Chen Qingsong , Yang Jiaqi , Zhang Wei , Ning Zhien , Teng Changqing , Ma Cong , Wu Lu , Wu Xiaoyong
Published: December 2021

The AlNbTiZr medium-entropy alloy (MEA) coatings with different Al contents were prepared on N36 zirconium alloy substrates by RF magnetron co-sputtering. The morphology, microstructure, mechanical properties, surface wettability and corrosion resistance of the AlNbTiZr MEA coatings were studied to evaluate the surface protection behavior of zirconium alloy cladding under operation conditions of a pressurized water reactor. The results showed that all the coatings were composite structures with amorphous and bcc-structured nanocrystals. With the increase of Al content, both the elastic modulus and hardness decreased first and then increased. The hydrophobicity of the coatings was enhanced compared with that of the substrate. The 10.2 at.% Al AlNbTiZr coating had the best corrosion resistance and the minimum oxygen penetration depth, which originated from the formation of a denser oxide layer consisting of Nb2Zr6O17 and ZrO2. This study provides an improved idea for the design and development of Al-containing MEA coating materials for accident tolerant fuel.
Platinum Nanoparticles Modified Copper/Titanium Electrodes as Electrocatalysts for Borohydride Oxidation
Authors: Balčiūnaitė Aldona , Zabielaitė Aušrinė , Upskuvienė Daina , Tamašauskaitė-Tamašiūnaitė Loreta , Stalnionienė Irena , Naruškevičius Leonas , Vaičiūnienė Jūratė , Selskis Algirdas , Juškėnas Remigijus , Norkus Eugenijus
Published: December 2021

In this study, sodium borohydride oxidation has been investigated on the platinum nanoparticles modified copper/titanium catalysts (PtNPsCu/Ti), which were fabricated by employing the electroless copper plating and galvanic displacement technique. ICP-OES, XRD, FESEM, and EDX have been used to characterize PtNPsCu/Ti catalysts’ composition, structure, and surface morphology. The oxidation of sodium borohydride was examined on the PtNPsCu/Ti catalysts using cyclic voltammetry and chrono-techniques.
Laboratory Characterization of Asphalt Binders Modified with Styrene Butadiene Rubber (SBR)
Authors: Hemmati Navid , Yun Jihyeon , Mazumder Mithil , Lee Moon-Sup , Lee Soon-Jae
Published: December 2021

The study describes the laboratory assessment (physical and rheological properties) of the binders (PG 64-22 and PG 76-22) modified with Styrene Butadiene Rubber (SBR), and a comprehensive comparison between these two modified binder types. PG 64-22 and PG 76-22 were used as base binders. Both of the base binders were blended with SBR at four different percentages of content (0%, 4%, 6%, and 8% by the weight of the binder). The base and modified binders were artificially short-term and long-term aged using a rolling thin film oven (RTFO) and pressure aging vessel (PAV) procedures. Superpave binder tests were conducted on the SBR modified binder using rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR). In depth rutting performance was investigated using Multiple Stress Creep Recovery (MSCR). The results of this study indicated that (1) the addition of SBR into both binders increased the viscosity and polymer modified asphalt (PMA) binders observed to have more significant effect on its viscosity property; (2) the higher the SBR content, the better the rutting resistance of the binder and it is observed that the effect is prominent on the control binder; (3) MSCR test results showed that the SBR modified binders improved the binder percentage recovery and found to have a more significant effect on the PG 76-22 binder compared to PG 64-22; and (4) both the control PG 64-22 and PMA PG 76-22 binders resulted in similar trends on the cracking properties and were found to have insignificant effects due to the addition of an SBR modifier.
Investigation on Variables Contributing to the Synthesis of C-S-H/PCE Nanocomposites by Co-Precipitation Method
Authors: You Ziyang , Xu Jing
Published: December 2021

The usage of nanoscale calcium silicate hydrate (nano C-S-H) proved to have an excellent promotion effect on the early performance of concrete as nano C-S-H with ultra-fine particle size can act as seeding for cement hydration. Therefore, it is of importance to tune the particle size during the synthesis process of nano C-S-H. In this paper, the influence of several variables of the particle size distribution (PSD) of nano C-S-H synthesized by chemical co-precipitation method with the aid of polycarboxylate (PCE) was studied by orthogonal experimental design. In addition, the composition, microstructure, and morphology of the C-S-H/PCE nanocomposites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum. The results showed that the concentration of reactants had a significant impact on the PSD of C-S-H/PCE nanocomposites, followed by the dosage of dispersant. Ultrasonic treatment was effective in breaking the C-S-H/PCE aggregates with unstable agglomeration structures. The change in synthetic variables had a negligible effect on the composition of the C-S-H/PCE nanocomposites but had a significant influence on the crystallinity and morphology of the composites.