bluuebunny/crossref_metadata_2025 huggingface dataset:
Myeloid Trem2 Dynamically Regulates the Induction and Resolution of Hepatic Ischemia-Reperfusion Injury Inflammation
Authors: Han Sheng , Li Xiangdong , Xia Nan , Zhang Yu , Yu Wenjie , Li Jie , Jiao Chenyu , Wang Ziyi , Pu Liyong
Published: March 2023

Trem2, a transmembrane protein that is simultaneously expressed in both bone marrow-derived and embryonic-derived liver-resident macrophages, plays a complex role in liver inflammation. The unique role of myeloid Trem2 in hepatic ischemia-reperfusion (IR) injury is not precisely understood. Our study showed that in the early stage of inflammation induction after IR, Deletion of myeloid Trem2 inhibited the induction of iNOS, MCP-1, and CXCL1/2, alleviated the accumulation of neutrophils and mitochondrial damage, and simultaneously decreased ROS formation. However, when inflammatory monocyte-macrophages gradually evolved into CD11bhiLy6Clow pro-resolution macrophages through a phenotypic switch, the story of Trem2 took a turn. Myeloid Trem2 in pro-resolution macrophages promotes phagocytosis of IR-accumulated apoptotic cells by controlling Rac1-related actin polymerization, thereby actively promoting the resolution of inflammation. This effect may be exercised to regulate the Cox2/PGE2 axis by Trem2, alone or synergistically with MerTK/Arg1. Importantly, when myeloid Trem2 was over-expressed, the phenotypic transition of monocytes from a pro-inflammatory to a resolution type was accelerated, whereas knockdown of myeloid Trem2 resulted in delayed upregulation of CX3CR1. Collectively, our findings suggest that myeloid Trem2 is involved in the cascade of IR inflammation in a two-sided capacity, with complex and heterogeneous roles at different stages, not only contributing to our understanding of sterile inflammatory immunity but also to better explore the regulatory strategies and intrinsic requirements of targeting Trem2 in the event of sterile liver injury.
Karyotype Evolution in Triatominae (Hemiptera, Reduviidae): The Role of Chromosomal Rearrangements in the Diversification of Chagas Disease Vectors
Authors: Reis Yago Visinho dos , de Oliveira Jader , Madeira Fernanda Fernandez , Ravazi Amanda , Oliveira Ana Beatriz Bortolozo de , Bittinelli Isadora da Silva , Delgado Luiza Maria Grzyb , de Azeredo-Oliveira Maria Tercília Vilela , Rosa João Aristeu da , Galvão Cleber , Alevi Kaio Cesar Chaboli
Published: March 2023

Several cytogenetic studies have already been performed in Triatominae, such that different karyotypes could be characterized (ranging from 2n = 21 to 25 chromosomes), being the changes in the number of chromosomes related mainly to fusion and fission events. These changes have been associated with reproductive isolation and speciation events in other insect groups. Thus, we evaluated whether different karyotypes could act in the reproductive isolation of triatomines and we analyzed how the events of karyotypic evolution occurred along the diversification of these vectors. For this, experimental crosses were carried out between triatomine species with different karyotypes. Furthermore, based on a phylogeny with 88 triatomine taxa (developed with different molecular markers), a reconstruction of ancestral karyotypes and of anagenetic and cladogenetic events related to karyotypic alterations was performed through the ChromoSSE chromosomal evolution model. All crosses performed did not result in hybrids (prezygotic isolation in both directions). Our modeling results suggest that during Triatominae diversification, at least nine cladogenetic events may be associated with karyotype change. Thus, we emphasize that these alterations in the number of chromosomes can act as a prezygotic barrier in Triatominae (karyotypic isolation), being important evolutionary events during the diversification of the species of Chagas disease vectors.
Sex and Gender Differences in Neurodegenerative Diseases: Challenges for Therapeutic Opportunities
Authors: Bianco Annalisa , Antonacci Ylenia , Liguori Maria
Published: March 2023

The term “neurodegenerative diseases” (NDs) identifies a group of heterogeneous diseases characterized by progressive loss of selectively vulnerable populations of neurons, which progressively deteriorates over time, leading to neuronal dysfunction. Protein aggregation and neuronal loss have been considered the most characteristic hallmarks of NDs, but growing evidence confirms that significant dysregulation of innate immune pathways plays a crucial role as well. NDs vary from multiple sclerosis, in which the autoimmune inflammatory component is predominant, to more “classical” NDs, such as Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, and spinal muscular atrophy. Of interest, many of the clinical differences reported in NDs seem to be closely linked to sex, which may be justified by the significant changes in immune mechanisms between affected females and males. In this review, we examined some of the most studied NDs by looking at their pathogenic and phenotypical features to highlight sex-related discrepancies, if any, with particular interest in the individuals’ responses to treatment. We believe that pointing out these differences in clinical practice may help achieve more successful precision and personalized care.
Engineered Peptides Enable Biomimetic Route for Collagen Intrafibrillar Mineralization
Authors: Cloyd Aya K. , Boone Kyle , Ye Qiang , Snead Malcolm L. , Spencer Paulette , Tamerler Candan
Published: March 2023

Overcoming the short lifespan of current dental adhesives remains a significant clinical need. Adhesives rely on formation of the hybrid layer to adhere to dentin and penetrate within collagen fibrils. However, the ability of adhesives to achieve complete enclosure of demineralized collagen fibrils is recognized as currently unattainable. We developed a peptide-based approach enabling collagen intrafibrillar mineralization and tested our hypothesis on a type-I collagen-based platform. Peptide design incorporated collagen-binding and remineralization-mediating properties using the domain structure conservation approach. The structural changes from representative members of different peptide clusters were generated for each functional domain. Common signatures associated with secondary structure features and the related changes in the functional domain were investigated by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) and circular dichroism (CD) spectroscopy, respectively. Assembly and remineralization properties of the peptides on the collagen platforms were studied using atomic force microscopy (AFM). Mechanical properties of the collagen fibrils remineralized by the peptide assemblies was studied using PeakForce-Quantitative Nanomechanics (PF-QNM)-AFM. The engineered peptide was demonstrated to offer a promising route for collagen intrafibrillar remineralization. This approach offers a collagen platform to develop multifunctional strategies that combine different bioactive peptides, polymerizable peptide monomers, and adhesive formulations as steps towards improving the long-term prospects of composite resins.
One Third of Malignant Pleural Mesothelioma Shows High Immunohistochemical Expression of MSLN or CXCR4 Which Indicates Potent Candidates for Endo-Radiotherapy
Authors: Hager Thomas , Borchert Sabrina , Wessolly Michael , Mathilakathu Alexander , Mairinger Elena , Kollmeier Jens , Mairinger Thomas , Hegedus Balazs , Greimelmaier Kristina , Wohlschlaeger Jeremias , Herrmann Ken , Mairinger Fabian Dominik
Published: March 2023

Malignant pleural mesothelioma (MPM) is a mainly asbestos-related tumour associated with a very poor prognosis. Therapeutic approaches include multimodal therapy and chemotherapeutics, with cisplatin being the drug of choice, but response rates of only up to 14% indicate very poor outcomes. Effective treatment options are lacking. Besides the diagnostic usage of radioligands in positron emission tomography (PET)/computed tomography (CT), the endo-radioligand therapy with Lu177 has been proven as a powerful tool in cancer therapy. Mesothelin (MSLN) and C-XC chemokine receptor 4 (CXCR4) are membrane-bound proteins, expressed in certain cancers, and thus are promising targets for endo-radiotherapy. A significant portion of high MSLN- or CXCR4-expressing tumors within the MPM may open the field for this sophisticated treatment approach in the near future. Formalin-fixed, paraffin-embedded (FFPE) tumour specimens from 105 patients suffering from MPM and treated at the Lung Cancer Centre of Essen and at the Helios Klinikum Emil von Behring Berlin were screened. The tumour samples were arranged in tissue microarrays. We immunohistochemically stained the tumour samples against MSLN and CXCR4. The protein expressions of the stainings were scored by a pathologist by using a semiquantitative method. The data obtained were correlated with the clinical outcome. Overall, 77.1% of the analysed tumours showed CXCR4 protein expression (25.7% of them at high expression level (Score 3)). 48.6% of all samples showed an overall strong staining (Score ≥ 2), 59% of the investigated tumours showed MSLN protein expression (10.5% of them at high expression (Score 3)), and 36.2% of all samples showed an overall strong staining (Score ≥ 2). Our results show significant tissue expression levels, for both CXCR4 and MSLN protein, in a major portion of clinical MPM samples. One-third of patients showed outstanding immunoexpression of at least one of these markers, making them interesting candidates for radioligand-based PET/CT diagnostics and follow-up and furthermore may profit from endo-radiotherapy.
Innovative Computerized Dystrophin Quantification Method Based on Spectral Confocal Microscopy
Authors: Codina Anna , Roldán Mònica , Natera-de Benito Daniel , Ortez Carlos , Planas Robert , Matalonga Leslie , Cuadras Daniel , Carrera Laura , Exposito Jesica , Marquez Jesus , Jimenez-Mallebrera Cecilia , M. Porta Josep , Nascimento Andres , Jou Cristina
Published: March 2023

Several clinical trials are working on drug development for Duchenne and Becker muscular dystrophy (DMD and BMD) treatment, and, since the expected increase in dystrophin is relatively subtle, high-sensitivity quantification methods are necessary. There is also a need to quantify dystrophin to reach a definitive diagnosis in individuals with mild BMD, and in female carriers. We developed a method for the quantification of dystrophin in DMD and BMD patients using spectral confocal microscopy. It offers the possibility to capture the whole emission spectrum for any antibody, ensuring the selection of the emission peak and allowing the detection of fluorescent emissions of very low intensities. Fluorescence was evaluated first on manually selected regions of interest (ROIs), proving the usefulness of the methodology. Later, ROI selection was automated to make it operator-independent. The proposed methodology correctly classified patients according to their diagnosis, detected even minimal traces of dystrophin, and the results obtained automatically were statistically comparable to the manual ones. Thus, spectral imaging could be implemented to measure dystrophin expression and it could pave the way for detailed analysis of how its expression relates to the clinical course. Studies could be further expanded to better understand the expression of dystrophin-associated protein complexes (DAPCs).
Salivary Exosomes in Health and Disease: Future Prospects in the Eye
Authors: Liu Angela , Hefley Brenna , Escandon Paulina , Nicholas Sarah E. , Karamichos Dimitrios
Published: March 2023

Exosomes are a group of vesicles that package and transport DNA, RNA, proteins, and lipids to recipient cells. They can be derived from blood, saliva, urine, and/or other biological tissues. Their impact on several diseases, such as neurodegenerative, autoimmune, and ocular diseases, have been reported, but not fully unraveled. The exosomes that are derived from saliva are less studied, but offer significant advantages over exosomes from other sources, due to their accessibility and ease of collection. Thus, their role in the pathophysiology of diseases is largely unknown. In the context of ocular diseases, salivary exosomes have been under-utilized, thus creating an enormous gap in the literature. The current review discusses the state of exosomes research on systemic and ocular diseases and highlights the role and potential of salivary exosomes as future ocular therapeutic vehicles.
Recent Theoretical Insights into the Oxidative Degradation of Biopolymers and Plastics by Metalloenzymes
Authors: Rovaletti Anna , De Gioia Luca , Fantucci Piercarlo , Greco Claudio , Vertemara Jacopo , Zampella Giuseppe , Arrigoni Federica , Bertini Luca
Published: March 2023

Molecular modeling techniques have become indispensable in many fields of molecular sciences in which the details related to mechanisms and reactivity need to be studied at an atomistic level. This review article provides a collection of computational modeling works on a topic of enormous interest and urgent relevance: the properties of metalloenzymes involved in the degradation and valorization of natural biopolymers and synthetic plastics on the basis of both circular biofuel production and bioremediation strategies. In particular, we will focus on lytic polysaccharide monooxygenase, laccases, and various heme peroxidases involved in the processing of polysaccharides, lignins, rubbers, and some synthetic polymers. Special attention will be dedicated to the interaction between these enzymes and their substrate studied at different levels of theory, starting from classical molecular docking and molecular dynamics techniques up to techniques based on quantum chemistry.
Resource Allocation in Decentralized Vehicular Edge Computing Network
Authors: Zhang Hongli , Li Ying
Published: March 2023

Computation-intensive vehicle tasks sharply increase with the rapid growth of intelligent vehicles. The technology of Mobile Edge Computing (MEC) has the possibility of assisting vehicles with computation offloading. To solve the problem of computation resource management and guarantee the security of resource transaction, we jointly combine the MEC network and the blockchain networks to build a blockchain based MEC offloading model. The non-cooperative interactions between MEC server and vehicles formulate a two-stage Stackelberg game in an aim to maximize their benefits and information security. We theoretically demonstrate the unique existence of Nash equilibrium, which enables participants to decide their optimal strategies. Finally, the performance of the proposed model is analyzed by conducting simulation experiments. Our proposed model optimizes resource allocation and also improves the security of the whole network.
Influence of Traffic Characteristics on Pavement Performance of Parking Lots
Authors: Ghadi Maen Qaseem , Ahmad Hesham , Jannoud Ismael
Published: March 2023

This research aims to identify and interpret the main traffic characteristics affecting the pavement condition index (PCI) of asphalt within parking areas. The study also examines the effect of severity and type of asphalt pavement distress on parking decisions. Previous literature examines the impact of the environment on asphalt pavement deterioration. This paper will focus on the shape of traffic operations within a parking area. The methodology includes applying a multilevel mixed regression model to reveal the hidden hierarchical relationship between traffic activities and the different types of pavement distresses and then discovering their effect on asphalt PCI. The resulting models showed that parking lots are aging faster than the common traveling roads due to the increased impact of axial loads on their surfaces at low and static speeds and some distinctive traffic characteristics. Moreover, some types of pavement distress, such as alligator cracks, potholes and depressions, appear more widely than others on the parking lot surface and significantly influence the parking decision. The conclusion of the research may significantly impact pavement design and maintenance management for parking lots.
Preparation of RGO/Fe3O4 Nanocomposites as a Microwave Absorbing Material
Authors: Chen Xingtian , Du Shumin , Hong Ruoyu , Chen Huaiyin
Published: March 2023

The hydrophobic nanocomposites of reduced graphene oxide (RGO) and Fe3O4 (RGO/Fe3O4) were prepared by a one-pot process through co-precipitation under alkaline conditions. The microwave absorption performance of the RGO/Fe3O4 nanocomposites was analyzed according to their electromagnetic parameters. The results showed that the RGO/Fe3O4 nanocomposites displayed better absorbing performance than the pristine Fe3O4 nanoparticles, owing to the synergistic effect of Fe3O4 and RGO. The maximum reflection loss (RL) of the RGO/Fe3O4 nanocomposites with a thickness of 2 mm reached −45.7 dB at 13.3 GHz, and the bandwidth (RL < −10 dB) ranged from 11.5 to 16.5 GHz. However, the maximum RL of the Fe3O4 nanoparticles with a thickness of 5 mm only reached −5.3 dB at 5.7 GHz. The RGO/Fe3O4 nanocomposites have a great potential application in high-performance electromagnetic microwave absorbing.
A Novel Model of Pathogenesis of Metarhizium anisopliae Propagules through the Midguts of Aedes aegypti Larvae
Authors: Bitencourt Ricardo , Santos-Mallet Jacenir , Lowenberger Carl , Ventura Adriana , Gôlo Patrícia , Bittencourt Vânia , Angelo Isabele
Published: March 2023

We assessed the effect of the entomopathogenic fungus Metarhizium anisopliae against Aedes aegypti. Conidia of M. anisopliae strains CG 489, CG 153, and IBCB 481 were grown in Adamek medium under different conditions to improve blastospore production. Mosquito larvae were exposed to blastospores or conidia of the three fungal strains at 1 × 107 propagules mL−1. M. anisopliae IBCB 481 and CG 153 reduced larval survival by 100%, whereas CG 489 decreased survival by about 50%. Blastospores of M. anisopliae IBCB 481 had better results in lowering larval survival. M. anisopliae CG 489 and CG 153 reduced larval survival similarly. For histopathology (HP) and scanning electron microscopy (SEM), larvae were exposed to M. anisopliae CG 153 for 24 h or 48 h. SEM confirmed the presence of fungi in the digestive tract, while HP confirmed that propagules reached the hemocoel via the midgut, damaged the peritrophic matrix, caused rupture and atrophy of the intestinal mucosa, caused cytoplasmic disorganization of the enterocytes, and degraded the brush border. Furthermore, we report for the first time the potential of M. anisopliae IBCB 481 to kill Ae. aegypti larvae and methods to improve the production of blastospores.
CD177 Inhibits Neutrophil Extracellular Trap Formation and Protects against Acute Pancreatitis in Mice
Authors: Zhang Junxian , Yang Xin , Xu Xingmeng , Shen Qinhao , Han Fei , Zhu Qingtian , Wu Keyan , Gu Aidong , Wu Dong , Xiao Weiming
Published: March 2023

The inflammatory immune response mediated by neutrophils is closely related to the progression of acute pancreatitis. Previous studies confirmed that CD177 is a neutrophil-specific marker involved in the pathogenesis of conditions such as systemic vasculitis, asthma, and polycythemia vera. Neutrophil extracellular trap (NET) formation is a specific death program by which neutrophils release nuclear DNA covered with histones, granule proteins, etc. It also plays an important role in host defense and various pathological reactions. However, the function of CD177 in regulating the generation of NETs and the development of acute pancreatitis (AP) is unclear. In our manuscript, CD177 was significantly elevated in blood neutrophils in patients and positively correlated with the AP disease severity. Then, recombinant human CD177 protein (rhCD177) could significantly improve pancreatic injury and the inflammatory response in AP mice, and reduce AP-related lung injury. Mechanistically, we found that rhCD177 could inhibit the formation of NETs by reducing reactive oxygen species (ROS) and myeloperoxidase (MPO)/citrullinated histone H3 (CitH3) release. For the first time, we discovered the potential of rhCD177 to protect AP in mice and inhibit the NET formation of AP. CD177 may be a potential treatment strategy for preventing or inhibiting the aggravation of AP.
The Effect of Anticoagulants on Early Implant Failure: A Retrospective Cohort Study
Authors: Chaushu Liat , Perez Noa , Botticelli Daniele , Xavier Samuel Porfirio , Kolerman Roni , Masri Daya
Published: March 2023

Background: Anticoagulants (AC) are among the most often prescribed drugs in the world. Data regarding ACs’ effect on the osseointegration of dental implants is lacking. Purpose: The aim of the present retrospective cohort study was to evaluate the effect of anticoagulants (AC) on early implant failure (EIF). The null hypothesis was that the use of AC increases the incidence of EIF. Materials and Methods: The research included 687 patients who underwent 2971 dental implant placements in the department of oral and maxillofacial surgery in Rabin medical center, Beilinson hospital, by specialists in oral and maxillofacial surgery. The study group comprised 173 (25.2%) patients and 708 (23.8%) implants using AC. The rest of the cohort served as a control. A structured form was used to collect data at patient and implant level. EIF was defined as implant failure within a period of up to 12 months from loading. EIF was the primary outcome parameter. A logistic regression model was used to predict EIF. Results: Implants placed in individuals ≥ 80 (odds ratio (OR) = 0.34, p = 0.05), and ASA 2/3 vs. ASA 1 individuals (OR = 0.30, p = 0.02/OR = 0.33, p = 0.03, respectively) had decreased odds of EIF, and implants in those using anticoagulants (OR = 2.64, p = 0.01) had increased odds of EIF. At the patient level, the odds of EIF in ASA 3 (OR = 0.53, p = 0.02) and IHD (OR = 0.40, p = 0.02) individuals decreased. In AF/VF (OR = 2.95, p = 0.01) individuals, EIF odds increased. Conclusions: Within the limitations of the present study, the use of AC is significantly associated with an increased likelihood of EIF: the OR was 2.64. Future research is required to validate and examine the prospective impact of AC on the osseointegration phenomena.
Tannin-Based Microbicidal Coatings for Hospital Privacy Curtains
Authors: Widsten Petri , Salo Satu , Niemelä Klaus , Helin Hanna , Salonen Minna , Alakomi Hanna-Leena
Published: March 2023

The goal of this study was to develop a sustainable, tannin-based option for silver-based and other current antimicrobial solutions for hospital privacy curtains. Commercial tree-derived tannins were characterized and their in vitro antibacterial properties against Staphylococcus aureus and Escherichia coli were determined. Hydrolysable tannins showed greater antibacterial efficacy than condensed tannins but differences in antibacterial efficacy between any of the tannins could not be attributed to their functional group content or molar mass. Outer membrane disruption was not a significant factor in antibacterial efficacy of tannins against E. coli. In a hospital field study, draw patches coated with hydrolysable tannins and affixed to privacy curtains reduced total bacteria count by 60% over eight weeks compared to their matching uncoated reference sides. In a follow-up laboratory study with S. aureus, very light spraying with water improved contact between bacteria and coating, enhancing the antibacterial effect by several orders of magnitude.
Nanohydroxyapatite-Coated Titanium Surface Increases Vascular Endothelial Cells Distinct Signaling Responding to High Glucose Concentration
Authors: Gomes Anderson M. , da Silva Danielle F. , Bezerra Fábio J. , Zambuzzi Willian F.
Published: March 2023

Aim: The success of dental implants depends on osseointegration can be compromised by well-known related adverse biological processes, such as infection and diabetes. Previously, nanohydroxyapatite-coated titanium surfaces (nHA_DAE) have been shown to contain properties that promote osteogenesis by enhancing osteoblast differentiation. In addition, it was hypothesized to drive angiogenesis in high-glucose microenvironments, mimicking diabetes mellitus (DM). On the other hand, the null hypothesis would be confirmed if no effect was observed in endothelial cells (ECs). Materials and methods: Titanium discs presenting the differential surfaces were previously incubated in an FBS-free cell culture medium for up to 24 h, which was, thereafter, supplemented with 30.5 mM of glucose to expose human umbilical vein endothelial cells (HUVECs, ECs) for 72 h. They were then harvested, and the sample was processed to provide molecular activity of specific genes related to EC survival and activity by using qPCR, and the conditioned medium by ECs was used to evaluate the activity of matrix metalloproteinases (MMPs). Results: Our data guaranteed better performance of this nanotechnology-involved titanium surface to this end once the adhesion and survival characteristics were ameliorated by promoting a higher involvement of β1-Integrin (~1.5-fold changes), Focal Adhesion Kinases (FAK; ~1.5-fold changes) and SRC (~2-fold changes) genes. This signaling pathway culminated with the cofilin involvement (~1.5-fold changes), which guaranteed cytoskeleton rearrangement. Furthermore, nHA_DAE triggered signaling that was able to drive the proliferation of endothelial cells once the cyclin-dependent kinase gene was higher in response to it, while the P15 gene was significantly down-regulated with an impact on the statement of angiogenesis. Conclusions: Altogether, our data show that a nanohydroxyapatite-coated titanium surface ameliorates the EC performance in a high-glucose model in vitro, suggesting its potential application in DM patients.
A Study on the Correlation between Ship Movement Characteristics and Ice Conditions in Polar Waters
Authors: Chen Liang , Huang Changhai , Wang Yanhao
Published: March 2023

The opening of arctic routes provides a new option for international navigation ships. The correlation between ship movement characteristics and ice conditions should be known, which will help ships adapt to the polar waters. Based on the voyage data and sea ice manual observation data of the ‘XUE LONG’ ship’s six voyages in polar waters, a correlation analysis model of ice conditions and ship movement characteristics was established in this work. First, the ship movement characteristics in polar waters were analyzed, such as the distribution characteristics of ship speeds, courses, and variation characteristics by using the descriptive statistical analysis method and data visualization analysis method. Then, by using multivariate correlation analysis and univariate controlled correlation analysis methods, the correlation between movement characteristics and ice conditions, such as ice concentration and thickness, and the correlation between different ice conditions themselves, were quantitatively analyzed. The result shows that the correlation analysis model of ice conditions and ship movement characteristics is reliable and effective and can obtain quantitative correlation analysis results. On the one hand, sea ice thickness has almost no significant correlation with ship movement characteristics, excluding the influence of sea ice concentration. On the other hand, excluding the influence of sea ice thickness, sea ice concentration is still significantly correlated with the absolute value of speed, speed variation, and course variation. The conclusions of this work have important reference significance for polar scientific investigations, commercial ships’ voyages in icy waters, and ships’ designs for icy waters.
Plant and Trees Pathogens: Isolation, Characterization and Control Strategies (1.0)
Authors: Laasli Salah-Eddine , Barka Essaid Ait , Lahlali Rachid
Published: March 2023

Agricultural production is under constant threat from biotic and abiotic stresses [...]
Biomechanical Comparison of Conventional Plate and the C-Nail® System for the Treatment of Displaced Intra-Articular Calcaneal Fractures: A Finite Element Analysis
Authors: Pînzaru Roxana Maria , Pavăl Silviu Dumitru , Perțea Mihaela , Alexa Ovidiu , Sîrbu Paul Dan , Filip Alexandru , Carp Adrian Claudiu , Savin Liliana , Forna Norin , Veliceasa Bogdan
Published: March 2023

The C-Nail® system is a novel intramedullary fixation method for displaced intra-articular calcaneal fractures. The aim of this study was to evaluate the biomechanical performance of the C-Nail® system and compare it with conventional plate fixation for the treatment of displaced intra-articular calcaneal fractures using finite element analysis. The geometry of a Sanders type-IIB fracture was constructed using the computer-aided design software Ansys SpaceClaim. The C-Nail® system (Medin, Nové Mesto n. Morave, Czech Republic) and the calcaneal locking plate (Auxein Inc., 35 Doral, Florida) and screws were designed according to the manufacturer specifications. Vertical loading of 350 N and 700 N were applied to the subtalar joint surfaces to simulate partial weight bearing and full weight bearing. Construct stiffness, total deformation, and von Mises stress were assessed. The maximum stress on the C-Nail® system was lower compared with the plate (110 MPa vs. 360 MPa). At the bone level the stress was found to have higher values in the case of the plate compared to the C-Nail® system. The study suggests that the C-Nail® system can provide sufficient stability, making it a viable option for the treatment of displaced intra-articular calcaneal fractures.
Collaborative Optimal Allocation of Urban Land Guide by Land Ecological Suitability: A Case Study of Guangdong–Hong Kong–Macao Greater Bay Area
Authors: Pan Tingting , Zhang Yu , Yan Fengqin , Su Fenzhen
Published: March 2023

Urban land optimization in urban agglomerations plays an important role in promoting territorial spatial planning to achieve high-quality development, land ecological suitability (LES) is one of the important variables influencing its urbanization and needs to be considered in urban growth simulation and modeling. This research proposed a multi-objective urban land optimization (MULO) model based on the non-dominated sorting genetic algorithm II (NSGA-II) which integrates the LES assessment. MULO starts with LES analysis based on a fuzzy analytical hierarchy process (AHP) and a minimum cumulative resistance (MCR) model. Then, two-step linear regression is used to optimize the quantity structure of built-up land. Finally, suitability and compactness are assigned to NSGA-II as objectives to obtain optimal spatial patterns. Taking the example of the Guangdong–Hong Kong–Macao Greater Bay Area, we found that all the newly added built-up land in 2030 is distributed in peri-urban areas around the original settlements, with approximate clustering in the northern part of Guangzhou and the southern part of Foshan under a balanced development scenario. This study highlights the importance of LES in urban growth modeling, and MULO can provide effective support for the spatial planning of urban agglomerations.
Rural Entrepreneurship Development in Southwest China: A Spatiotemporal Analysis
Authors: Li Haoying , Nielsen Jonas Østergaard , Chen Rui
Published: March 2023

Rural entrepreneurship has been seen by the central government of China as a key means to rural vitalization. However, research focus on the long-term developmental status of rural entrepreneurship at local scale has been limited. According to industry types of differentiation, this research describes rural enterprises registered in the administrative area of Mianyang, southwest China, from 2011 to 2020. The spatial-temporal distribution rule of rural entrepreneurship is explored via a quantitative approach focused on spatial analysis and correlation analysis, as well as the application of geocoding on web data. How contexts such as the natural base, socio-economic condition, and institutional arrangements impact this distribution are empirically explored and discussed. The paper adds spatial-temporal insights into the role of the context of rural entrepreneurship. In particular, the paper highlights that rural entrepreneurship is a process potentially best explored at the regional scale and that physical condition and institutional support play central roles in rural entrepreneurship in southwest China.
Study on Temperature-Dependent Uniaxial Tensile Tests and Constitutive Relationship of Modified Polyurethane Concrete
Authors: Han Yanqun , Meng Xiandong , Feng Fan , Song Xuming , Huang Fanglin , Wen Weibin
Published: March 2023

Modified polyurethane concrete (MPUC) is a new material for steel deck pavements. In service, the pavement is often cracked due to excessive tensile stress caused by temperature changes. In order to study the tensile properties of MPUC in the diurnal temperature range of steel decks, uniaxial tensile tests of MPUC were carried out at five temperatures. Three kinds of specimens and a novel fixture were designed and fabricated to compare the results of four different tensile test methods. The deformation of the specimen was collected synchronously by two methods: pasting strain gauge and digital image correlation (DIC) technique. Based on the experiment, the tensile mechanical properties, failure modes, and constitutive relations of MPUC were studied under the effect of temperature. The research results show that the novel fixture can avoid stress concentration. By observing the fracture surface of the specimens, the bonding performance is great between the binder and the aggregate at different temperatures. The tensile strength and elastic modulus of MPUC decrease with increasing temperatures, while the fracture strain, and fracture energy increase with increasing temperatures. The formulas of temperature-dependent tensile strength, fracture strain, and elastic modulus of MPUC were established, and the constitutive relationship of MPUC is further constructed in the rising stage under uniaxial tension. The calculation results show good agreement with experimental ones.
Compartmentalized Quantitative Analysis of Concrete Sulfate-Damaged Area Based on Ultrasonic Velocity
Authors: Jian Yinghua , Liu Dunwen , Cao Kunpeng , Tang Yu
Published: March 2023

The corrosion of concrete in sulfate environments is a difficult problem in the durability of civil engineering structures. To investigate the variability of deterioration damage to concrete structures by sulfate erosion under non-destructive testing and quantify the protective effect of silane coatings on concrete under the action of sulfate erosion, an accelerated erosion experiment was carried out using field sampling in a tunnel project under a sulfate erosion environment. By means of ultrasonic velocity measurement and CT scanning, the samples protected by a silane coating under the sulfate attack environment were compared with those not protected. The deterioration characteristics of concrete under the sulfate attack environment and the protective effect of silane coating on the concrete structure were analyzed. In addition, a method for evaluating the sulfate damage to concrete based on CT images and ultrasonic velocity analysis was proposed. The results show that the samples prepared in the field show a significant difference in ultrasonic velocity in the process of erosion and deterioration according to the material difference at the measuring point interface. Through the overall damage evaluation analysis of the sample, it is concluded that the damage degree of the protected group sample is light and the heterogeneity is weak, whereas the local damage to the exposed group is serious. Combined with the CT image analysis of concrete before and after loading, the distribution characteristics of the damaged area divided by the concrete sulfate damage evaluation method proposed in this paper are highly similar to the real situation. The results of the study can provide a reference for similar projects for the detection, analysis, protection and evaluation of sulfate-attacked concrete.
Impact of Particle Size Distribution in the Preform on Thermal Conductivity, Vickers Hardness and Tensile Strength of Copper-Infiltrated AISI H11 Tool Steel
Authors: Vetter Johannes , Beneder Samuel , Kandler Moritz , Feyer Felix , Körner Carolin , Schmidt Michael
Published: March 2023

Spontaneous infiltration of a porous preform by a metallic melt provides the potential of generating metal matrix composites (MMCs) with tailored combinations of material properties at low cost. The bulk of tool inserts for injection molding must sustain high mechanical and thermal loads and simultaneously exhibit high thermal conductivity for efficient temperature control of the mold insert. To fulfill these contradictory requirements, AISI H11 tool steel preforms were infiltrated by liquid copper. The impact of the fine powder fraction (0 wt.% to 15 wt.%) blended to a coarse H11 powder in the preform on thermal conductivity, Vickers hardness and tensile strength was elucidated. The thermal conductivity of the composites could be enhanced by a factor of 1.84 (15 wt.% fine powder) and 2.67 (0 wt.% fine powder) with respect to the sintered H11 tool steel. By adding 15 wt.% fine powder to the coarse host powder, the tensile strength and Vickers hardness of the copper-infiltrated steel were 1066.3 ± 108.7 MPa and 366 ± 24 HV1, respectively, whereas the H11 tool steel yielded 1368.5 ± 89.3 MPa and 403 ± 17 HV1, respectively. Based on the results obtained, an appropriate particle size distribution (PSD) may be selected for preform preparation according with the requirements of a future mold insert.
Constitutive Analysis and Microstructure Characteristics of As-Homogenized 2198 Al–Li Alloy under Different Hot Compression Deformation Conditions
Authors: Li Huiyu , Li Xiwu , Yan Hongwei , Li Yanan , Geng Libo , Xun Chenyang , Li Zhihui , Zhang Yongan , Xiong Baiqing
Published: March 2023

The 2198 Al–Li alloy has unique superiority in mechanical performance and has been extensively used in the aerospace field. In this study, the hot deformation behavior of the 2198 Al–Li alloy was investigated on a Gleeble-1500 thermomechanical simulator with a strain rate of 0.01–10 s−1 in the temperature range of 330–510 °C. The Arrhenius constitutive equation of the alloy was established based on the true stress–strain curves to describe the rheology behaviors during the deformation of the alloy. The processing maps under the strain of 0.2–0.8 were constructed, which indicates the efficiency of power dissipation and instability of the deformed alloy. It was found that the instability domains are more likely to occur in the regions of low deformation temperature and high strain rate, corresponding to the high Zener–Hollomon (Z) parameter. The microstructure evolution of the studied alloy with different Z parameters was characterized. Then, the dynamic recrystallization (DRX) behavior was studied by electron backscatter diffraction, and the misorientation angle of deformed specimens was analyzed. The effect of different deformation temperatures and strain rates on the microstructure of the alloy and the behavior of dislocations and precipitations were investigated by transmission electron microscopy. The results demonstrate that continuous dynamic recrystallization (CDRX) and geomatic dynamic recrystallization (GDRX) mainly occur at the deformation conditions of a low Z value, and discontinuous dynamic recrystallization (DDRX) is likely to occur with increasing Z values.
A Review of the Extruder System Design for Large-Scale Extrusion-Based 3D Concrete Printing
Authors: Chen Hao , Zhang Daobo , Chen Peng , Li Ning , Perrot Arnaud
Published: March 2023

Extrusion-based 3D concrete printing (E3DCP) has been appreciated by academia and industry as the most plausible candidate for prospective concrete constructions. Considerable research efforts are dedicated to the material design to improve the extrudability of fresh concrete. However, at the time of writing this paper, there is still a lack of a review paper that highlights the significance of the mechanical design of the E3DCP system. This paper provides a comprehensive review of the mechanical design of the E3DCP extruder system in terms of the extruder system, positioning system and advanced fittings, and their effects on the extrudability are also discussed by relating to the extrusion driving forces and extrusion resistive forces which may include chamber wall shear force, shaping force, nozzle wall shear force, dead zone shear force and layer pressing force. Moreover, a classification framework of the E3DCP system as an extension of the DFC classification framework was proposed. The authors reckoned that such a classification framework could assist a more systematic E3DCP system design.
Corrosion-Effected Bond Behavior between PVA-Fiber-Reinforced Concrete and Steel Rebar under Chloride Environment
Authors: Zhang Xuhui , Wu Xun , Wang Yang
Published: March 2023

Corrosion-effected bond behavior between polyvinyl-alcohol-fiber-reinforced concrete and steel rebar under a chloride environment is the experimental subject studied in the present work. Twenty-four pull-out specimens are designed and subjected firstly to an accelerated corrosion test. The effects of polyvinyl alcohol fibers on the cracking behavior, chloride penetration of concrete members and the corrosion loss of steel rebars during the corrosion test are discussed. After this, these corroded specimens are subjected to a pull-out test. The failure mode, the bond-slip curves and the typical bond-stress values are measured during the test. The effects of polyvinyl alcohol fibers and corrosion loss on bond behavior between polyvinyl-alcohol-fiber-reinforced concrete and steel rebar are clarified. Results show that the polyvinyl-alcohol-fiber-reinforced concrete exhibits worse resistance to corrosion damage than plain concrete. The cracking width, chloride penetration depth in concrete and the corrosion loss of steel rebar are more serious for the specimens with more polyvinyl alcohol fibers. The polyvinyl alcohol fibers also negatively affect bonding in ascending branches for both the specimens, but improve the bonding in descending branches after peak stress in the case of splitting. In the present test, the bond strength of corrosive specimens is increased slightly and then decreases gradually with the deepening of corrosion loss. The failures of specimens change from pull-out to splitting-pull-out as the corrosion time exceeds 30 days. Compared with uncorroded specimens, the maximum degradation of bond strength is about 50.1% when the corrosion is increased from 0% to 15%.
Application of Atmospheric-Pressure Jet Plasma in the Presence of Acrylic Acid for Joining Polymers without Adhesives
Authors: Günther Roman , Caseri Walter , Brändli Christof
Published: March 2023

This study investigates the treatment of surfaces with jet plasma at atmospheric pressure in the presence of acrylic acid as a resource-saving and efficient approach to joining polymers on polystyrene (PS) and polyamide 12 (PA 12) surfaces. Acrylic acid was added in order to introduce functional groups to the polymer surfaces. XPS analysis revealed a high density of oxygen-containing groups, e.g., carboxylic acid groups, on the polymer surfaces, the detailed composition depending on the polymer. The AFM measurements indicated that the modification of polyamide resulted in morphological changes and an increase in surface roughness due to polymer recrystallization. When the surface-modified polymers were brought in contact under a load, significant adhesion between the polymer surfaces was measured. In particular, PS and PA 12, which are otherwise difficult to join by gluing, could readily be connected in this way. The joint polymers could be separated intentionally by immersion in water, thus enabling the recycling of the materials. The resistance of the joint to water depends on the polymer system, with polyamide providing strikingly higher resistance than polystyrene. Accordingly, treating the joint polymers with water allows debonding on demand, particularly when PS is involved. Exposure of modified polymer surfaces to solutions of metal ions increased the resistance of joint polymers to water.
Durability and Thermal Behavior of Functional Paints Formulated with Recycled-Glass Hollow Microspheres of Different Size
Authors: Calovi Massimo , Rossi Stefano
Published: March 2023

This study aims to assess the effect of hollow glass microspheres of different sizes derived from glass industry waste on the durability and thermal behavior of waterborne paint. The coatings were characterized by electron microscopy to investigate the distribution of the spheres and their influence on the layer morphology. The impact of the various glassy spheres on the mechanical feature of the coatings was assessed using the Buchholz hardness test and the Scrub abrasion test. The role of the spheres in altering the durability of the samples was analyzed by the salt spray exposure test and the electrochemical impedance spectroscopy measurements. Finally, a specific accelerated degradation test was carried out to explore the evolution of the thermal behavior of the composite coatings. Ultimately, this work revealed the pros and cons of using hollow glass spheres as a multifunctional paint filler, highlighting the size of the spheres as a key parameter. For example, spheres with adequate size (25–44 µm), totally embedded in the polymeric matrix, are able to reduce the thermal conductivity of the coating avoiding local heat accumulation phenomena.
In Vitro Degradation of Mg-Doped ZrO2 Bioceramics at the Interface with Xerostom® Saliva Substitute Gel
Authors: Bizo Liliana , Mureşan-Pop Marieta , Barabás Réka , Barbu-Tudoran Lucian , Berar Antonela
Published: March 2023

Zirconia-based bioceramics, one of the most important materials used for dental applications, have been intensively studied in recent years due to their excellent mechanical resistance and chemical inertness in the mouth. In this work, the structural, morphological and dissolution properties of the Zr1−xMgxO2 (x = 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) system, prepared by the conventional ceramic method, were evaluated before and after immersion in saliva substitute gel (Xerostom®, Biocosmetics Laboratories, Madrid, Spain), one of the most common topical dry mouth products used in dentistry. The X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) techniques were employed to investigate the phase transformations and morphology of the ceramics during the degradation process in Xerostom®. In vitro analyses showed overall good stability in the Xerostom® environment, except for the x = 0.05 composition, where significant t- to m-ZrO2 transformation occurred. In addition, the strong interconnection of the grains was maintained after immersion, which could allow a high mechanical strength of the ceramics to be obtained.
Topological Optimisation Structure Design for Personalisation of Hydrogel Controlled Drug Delivery System
Authors: Gao Yang , Li Tan , Meng Fanshu , Hou Zhenzhong , Xu Chao , Yang Laixia
Published: March 2023

Personalised controlled drug delivery systems (CDDSs) can adjust drug concentration levels according to patient needs, which has enormous research prospects in precision medicine. In this study, the topological optimisation method was utilised in the structural design of a hydrogel CDDS to achieve a parameter-based adjustment of the drug average concentration in the hydrogel. A polyacrylamide/sodium alginate dual-network hydrogel was selected as a drug carrier, and tetracycline hydrochloride was used as a model drug. The topological optimisation model of the hydrogel CDDS was developed. The effects of the mesh size, target concentration, and volume factor on the optimised results were investigated. Hydrogel flow channel structures were obtained, which satisfied the different target concentrations. To verify the rationality of the optimisation model, in vitro drug release experiments were carried out. The results show that the hydrogel CDDS can control drug release within 7 days, and the drug release tends to follow zero-order release behaviour. The adjustable average concentration of tetracycline hydrochloride in hydrogel CDDS is recommended in the range of 20.79 to 31.04 mol/m3. This novel method provides a reference for personalised structure design of CDDS in the context of precision medicine.