bluuebunny/crossref_metadata_2025 huggingface dataset:
Designing Healing Destinations: A Practical Guide for Eco-Conscious Tourism Development
Authors: Blau Marie Luise , Panagopoulos Thomas
Published: September 2022

The design and sustainable development of tourist destinations in sensitive environments must follow an environmentally conscious approach that meets the resource and service needs of present and future generations without compromising the health of the ecosystems that provide them. The aim of this paper is to develop an eco-conscious design framework for tourist destinations in sensitive natural areas, as these are becoming increasingly attractive and popular in the tourism sector. This paper gives an overview of relevant fields of impact at the destination, which are drawn from holistic and nature-based approaches. The outcome is a three-dimensional design guidance, which creates a unique destination that focuses on creating a symbiotic relationship between humans and nature in which health is achievable for both. The approach was exemplified in a “Yoga house on a Cliff” architectural competition that took place in Serra da Estrela Natural Park in Portugal. The landscape was analysed with the Strolling method and the 3-dimensional design framework was used to design an authentic place in the prtotected mountain. Permaculture and nature-based solutions were used to structure the design and its elements wth a focus on environmental sustainability and the improvement of human health. This study provides evidence that an eco-conscious design has the potential to overcome incompatibilities and provide health-driven ecotourism in protected areas.
Participatory Learning and Co-Design for Sustainable Rural Living, Supporting the Revival of Indigenous Values and Community Resiliency in Sabrang Village, Indonesia
Authors: Utami Lira Anindita , Lechner Alex M. , Permanasari Eka , Purwandaru Pandu , Ardianto Deny Tri
Published: September 2022

Industrialization and urbanization have affected Indonesia’s rural communities and farming culture, which were once integral parts of its ecological system. This paper presents a participatory co-design approach based on the local and traditional learning philosophy of niteni to support sustainable development. The participatory co-design approach encouraged collaboration between marginalized communities, government bodies, and a multidisciplinary academic team. Through this lens, interviews, forums, and an ethnographic study were undertaken in order to acquire data and information for idea generation and planning. Firstly, eight niteni themes were identified, including the environment and ecosystems, traditional values and farming culture, crafting skills, manufacturing, and the local economy. Building on an understanding of the challenges associated with each of these themes, we identified future development priorities. A key action identified was the reintroduction of traditional farming, in particular the planting of local rice varieties and the local tradition of Pranatamangsa, which promote human–nature connections such as farming activities and rituals following natural seasonal cycles. Finally, design approaches were used to revive the local rice farming tradition (Rojolele Delanggu), including product branding and packaging designs to support regional identity. The paper concludes that the inclusion of design thinking in a sustainable development strategy based on cultural specificity can increase participation and support traditional indigenous practices and community resiliency.
Impact of Internet Use on Farmers’ Organic Fertilizer Application Behavior under the Climate Change Context: The Role of Social Network
Authors: Ma Qianhui , Zheng Shaofeng , Deng Peng
Published: September 2022

Climate change and global warming significantly influence farmers’ activity and lead to lower production yield. To increase production without deteriorating the environment, it is vital to substitute chemical fertilizer with organic fertilizer. The utilization of organic fertilizer not only improves the soil quality but also protects the environment and helps mitigate global warming repercussions. So, there is a need to promote organic fertilizer utilization. The Internet, as an essential information medium, presently has a profound influence on farmers’ production behavior. However, the relationship between Internet use and the application of organic fertilizer is explicitly sparse, especially in China. Using the survey data of 797 vegetable growers, the current study explores the impact of Internet use on farmers’ organic fertilizer application behavior. The present study employs the propensity score matching (PSM) method to meet the study objective. According to the findings, it is unveiled that the Internet significantly promotes behavior towards applying organic fertilizer by approximately 10%. Further, the heterogeneity results show that the degree of impact varies due to differences in the level of education, vegetable farming income, and the number of vegetable laborers in the family. Moreover, social networks are also used to explore the nexus between the Internet and organic fertilizer application. The findings reveal that social networks favorably play the mediating role. The overall results propose that policymakers should establish the Internet infrastructure and an official online platform to help farmers consolidate and extend the scale of their social networks and exchange information more conveniently to improve their ability to apply environment-friendly production technology.
Usnic Acid Isolated from Usnea antarctica (Du Rietz) Reduced In Vitro Angiogenesis in VEGF- and bFGF-Stimulated HUVECs and Ex Ovo in Quail Chorioallantoic Membrane (CAM) Assay
Authors: Petrová Klaudia , Bačkorová Miriam , Demčišáková Zuzana , Petrovová Eva , Goga Michal , Vilková Mária , Frenák Richard , Bačkor Martin , Mojžiš Ján , Kello Martin
Published: September 2022

Natural products include a diverse set of compounds of drug discovery that are currently being actively used to target tumor angiogenesis. In the present study, we evaluated the anti-angiogenic activities of secondary metabolite usnic acid isolated from Usena antarctica. We investigated the in vitro effects on proliferation, migration, and tube formation of VEGF- and bFGF-stimulated HUVECs. Ex ovo anti-angiogenic activity was evaluated using the CAM assay. Our findings demonstrated that usnic acid in the concentration of 33.57 µM inhibited VEGF (25 ng/mL) and bFGF (30 ng/mL)-induced HUVECs proliferation, migration, and tube formation. The ex ovo CAM model was used to confirm the results obtained from in vitro studies. VEGF- and bFGF-induced vessel formation was inhibited by usnic acid after 72 h in over 2-fold higher concentrations compared to in vitro. Subsequently, histological sections of affected chorioallantoic membranes were stained with hematoxylin–eosin and alcian blue to determine the number and diameter of vessels as well as the thickness of the individual CAM layers (ectoderm, mesoderm, endoderm). Usnic acid was able to suppress the formation of VEGF- and bFGF-induced vessels with a diameter of less than 100 μm, which was demonstrated by the reduction of mesoderm thickness as well.
Variation in Phenolic Profile, Antioxidant, and Anti-Inflammatory Activities of Salvadora oleoides Decene. and Salvadora persica L. Fruits and Aerial Part Extracts
Authors: Khanam Arifa , Ahmad Ashfaq , Iftikhar Neelam , Ali Qasim , Fatima Tabinda , Alswailmi Farhan Khashim , Hussain Abdullah Ijaz , Alnasser Sulaiman Mohammed Abdullah , Akhtar Jamshaid
Published: September 2022

(1) Background: The objective of this study was to investigate the potential of Salvadora oleoides (S. oleoides) and Salvadora persica (S. persica) polyphenols as antioxidant and anti-inflammatory agents. (2) Methods: Aerial parts and fruits of S. oleoides and S. persica were collected from the periphery of District Bhakkar, Punjab, Pakistan. Methanol extracts were prepared using the Soxhlet extraction technique. Extract yield varied from 8.15 to 19.6 g/100 g dry plant material. RP-HPLC revealed the detection of thirteen phenolic aids and five flavonoids. Gallic acid, hydroxy benzoic acid, chlorogenic acid, and cinamic acid were the major phenolic acids, whereas catechin, rutin, and myricetin were the flavonoids detected. (3) Results: Maximum total phenolic contents (TPCs) (22.2 mg/g of dry plant material) and total flavonoid contents (TFCs) (6.17 mg/g of dry plant material) were found in the fruit extract of S. persica, and the minimum TPC (11.9 mg/g) and TFC (1.72 mg/g) were found in the aerial part of S. oleoides. The fruit extract of S. persica showed the highest DPPH radical scavenging activity. In vivo anti-inflammatory activity of all the extracts was performed on albumin-induced rat paw edema that was comparable with the standard indomethacin; S. persica fruit extract showed remarkable anti-inflammatory activity. Analgesic activity of aerial part and fruit extracts of S. oleoides and S. persica was investigated using a mouse model, and the results showed that maximum possible analgesia of fruit extracts of S. persica was 53.44%, which is better than the PC group (52.98%). (4) Conclusions: The variations in the antioxidant, anti-inflammatory, and analgesic activities of methanolic extracts of S. oleoides and S. persica were found to be significant, and they have therapeutic potential as antioxidant, analgesic, and anti-inflammatory agents.
Plasma Polyamines Decrease in Patients with Obstructive Cholecystitis
Authors: Akbaraliev Amaar A. , Akhvlediani Leila , Kavazashvili Ana , Diasamidze Emzar , Surmanidze Omar , Gassen Nils C. , Anderzhanova Elmira A.
Published: September 2022

Polyamines (PAs), endogenous metabolites with a wide range of biological activities, are synthesized at a high rate in liver supporting hepatocyte proliferation and survival. The liver appears as an important regulator of plasma PAs; however, the perspective to exploit plasma PA measurements as indicators for liver function was not explored. This study aimed to evaluate the value of the plasma levels of PAs as a biomarker of pathological changes in the liver in patients with obstructive cholecystitis. The levels of polyamines and their acetylated forms were measured using HPLC/UV in the plasma of patients with obstructive cholecystitis and in healthy subjects. PA turnover was assessed by the ratio between an acetylated form of PA and PA. An effect of diet preference of cheese or meat, the major exogenous sources of PAs, smoking, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in anamnesis was also evaluated in healthy subjects. We found that the plasma levels of spermine and acetylated spermidine decreased in patients with obstructive cholecystitis without a concurring increase in the total plasma bilirubin and amylase levels. The turnover of spermine and spermidine was also changed, suggesting a decrease in the rate of PA degradation in the liver. In healthy subjects, the PA levels tended to mirror chronic smoking and recent SARS-CoV-2 infection but were not relevant to diet factors. A number of observations indicated the role of physical exercise in the regulation of the plasma pool of PA. The decrease in plasma PA levels and index of PA turnover in the cholestasis syndrome indicate the liver’s metabolic function reduction. A conceivable effect of lung-related conditions on plasma PA, while indicating low specificity, nonetheless, speaks favorably about the high sensitivity of plasma PA measurement as an early diagnostic test in the clinic.
Microstructural Evolution during Accelerated Tensile Creep Test of ZK60/SiCp Composite after KoBo Extrusion
Authors: Wang Yang-Yang , Jia Chen , Tayebi Morteza , Hamawandi Bejan
Published: September 2022

In the current study, the creep properties of magnesium alloy reinforced with SiC particles were investigated. For this purpose, ZK60/SiCp composite was produced by the stir casting method following the KoBo extrusion and precipitation hardening processes. The creep tests were performed at 150 °C under 10–110 MPa. The results showed that the stress exponent (n) and the average true activation energy (Q) was changed at high stresses, was found with increasing stress, the creep mechanism changing from grain boundary sliding to dislocation climb. The results of microstructure characterization after the creep test showed that at low stresses, the dynamic recrystallization resulting from twinning induced the GBS mechanism. However, at high stresses, with increasing diffusion rates, conditions are provided for dynamic precipitation and the dislocation climb of the dominant creep mechanism. Examination of the fracture surfaces and the surrounding areas showed that the cavity nucleation in the ternary boundary and surrounding precipitation was the main cause of damage. The evaluation of the samples texture after creep showed that the unreinforced alloy showed a moderately strong fiber texture along the angle of ϕ1 = 0–90°, which was tilted about Φ = 10°. A new strong texture component was observed at (90°, 5°, 0°) for the composite sample, which crept due to minor splitting of the basal pole by ~5° toward RD.
Halochromic Inks Applied on Cardboard for Food Spoilage Monitorization
Authors: Leite Liliana , Boticas Inês , Navarro Miguel , Nobre Luís , Bessa João , Cunha Fernando , Neves Pedro , Fangueiro Raúl
Published: September 2022

Control of food spoilage is a critical concern in the current world scenario, not only to ensure the quality and safety of food but also to avoid the generation of food waste. This paper evaluates a dual-sensor strategy using six different pH indicators stamped on cardboard for the detection of spoilage in three different foods: beef, salmon, and strawberries. After function validation and formulation optimizations in the laboratory, the halochromic sensors methyl orange and bromocresol purple 2% (w/v) were stamped on cardboard and, in contact with the previously mentioned foods, were able to produce an easily perceptible signal for spoilage by changing color. Additionally, when it comes to mechanical characterization the inks showed high abrasion (>100 cycles) and adhesion resistance (>91%).
Research on the Properties and Mechanism of Carbon Nanotubes Reinforced Low-Carbon Ecological Cement-Based Materials
Authors: Cui Kai , Zhang Jixin , Chang Jun , Sabri Mohanad Muayad Sabri , Huang Jiandong
Published: September 2022

SAC (sulfoaluminate cement) has become a research hotspot as a low-carbon ecological cement. In addition, multi-walled carbon nanotubes have good thermal, mechanical, and electrical properties and can serve as excellent nano-reinforced cement-based fillers. This study explored the dispersion of carbon nanotubes (CNTs) and researched the effect of CNTs on the mechanical properties, hydration process, hydration products, and microstructure of SAC paste, and the mechanism of CNT-enhanced SAC paste was revealed. The results showed that the mechanical properties of SAC paste were significantly improved after the addition of CNTs. When the CNT content was 0.05%, 0.1%, and 0.15%, the compressive strength after 28 d was increased by 13.2%, 18.3%, and 22.5%, respectively; compared with the C0 group (without CNTs), the flexural strength increased by 8.2%, 11.3%, and 14.4%, respectively. The addition of CNTs accelerated the hydration process of SAC paste. Due to the adsorption effect and nucleation effect of CNTs, more hydration products were generated, filling the matrix’s pores and improving its compactness. The mechanism of CNTs enhanced SAC paste was revealed. CNTs and hydration products co-filled the pores, including AFt (ettringite) and AH3 (gibbsite). CNTs improve the mechanical properties of SAC paste through filling, bridging, crack bending, deflection, pulling out, and pulling off.
Advanced Ceramic Materials with Functional Properties
Authors: Bochenek Dariusz
Published: September 2022

With the dynamic progress in technology worldwide, the research into new engineering materials applies to a wide range of materials with exciting properties [...]
Optimal Design of Acoustic Metamaterial of Multiple Parallel Hexagonal Helmholtz Resonators by Combination of Finite Element Simulation and Cuckoo Search Algorithm
Authors: Yang Fei , Wang Enshuai , Shen Xinmin , Zhang Xiaonan , Yin Qin , Wang Xinqing , Yang Xiaocui , Shen Cheng , Peng Wenqiang
Published: September 2022

To achieve the broadband sound absorption at low frequencies within a limited space, an optimal design of joint simulation method incorporating the finite element simulation and cuckoo search algorithm was proposed. An acoustic metamaterial of multiple parallel hexagonal Helmholtz resonators with sub-wavelength dimensions was designed and optimized in this research. First, the initial geometric parameters of the investigated acoustic metamaterials were confirmed according to the actual noise reduction requirements to reduce the optimization burden and improve the optimization efficiency. Then, the acoustic metamaterial with the various depths of the necks was optimized by the joint simulation method, which combined the finite element simulation and the cuckoo search algorithm. The experimental sample was prepared using the 3D printer according to the obtained optimal parameters. The simulation results and experimental results exhibited excellent consistency. Compared with the derived sound absorption coefficients by theoretical modeling, those achieved in the finite element simulation were closer to the experimental results, which also verified the accuracy of this optimal design method. The results proved that the optimal design method was applicable to the achievement of broadband sound absorption with different low frequency ranges, which provided a novel method for the development and application of acoustic metamaterials.
Investigation on the Curvature and Stress Distribution of Laminates Based on an Analytic Solution and FE Simulation
Authors: Liu Chao , Günther Anne , Deng Yuanbin , Kaletsch Anke , Herrmann Mathias , Broeckmann Christoph
Published: September 2022

The potential combinations of favorable properties give metal–ceramic laminates (MCLs) a high degree of application flexibility. However, the different thermal expansion coefficients (CTEs) and shrinkage rates of the metals and ceramics during the co-sintering process often lead to large internal stresses that cause undesired deformation or even production failures. In practice, the identification of manufacturable MCLs relies on the “trial and error” principle, which usually requires a long development period. Therefore, there is a great demand for analytic and numerical methods that allow the prediction of the deformation and manufacturability of MCLs during the co-sintering process. The main objective of this study is to investigate the curvature and stress distribution in the MCLs (steel 17-4PH/ ceramic 3Y-TZP) based on the analytic solution and finite element (FE) simulation. To achieve this, the Young’s moduli (E) and shear moduli (G) at high temperatures and the CTEs of both materials were measured. In addition, the curvatures and stress distributions of the two-layer and three-layer laminates were obtained based on the analytic method and FE simulation, which were in very good agreement. Furthermore, the influence of the CTE, Young’s modulus, height ratio, and interface on the curvature were studied. The results showed that the CTE and height ratio have a higher influence on the curvature in comparison to the Young’s modulus. The interface prevents the curvature significantly by assuming it to be a cohesive surface in the FE simulation. This provides hints to avoid delamination during the manufacturing process.
Application of the Acoustic Emission Method and Artificial Neural Networks to Assess the Damaging Effect of High Temperature on the Structure of Fibre-Cement Boards
Authors: Gorzelańczyk Tomasz , Schabowicz Krzysztof , Szymków Mateusz
Published: September 2022

This article shows the results of research into the damaging effect of high temperature on the structure of fibre-cement boards. Samples of fibre-cement boards were exposed to high temperatures over various lengths of time and then they were investigated under the three-point bending and acoustic emission methods. In this way, the critical temperature and the duration of its influence on the structure of a fibre-cement board were determined. An artificial neural network was used to analyse the results obtained using the acoustic emission method. The investigations showed a marked fall in the number of registered AE events for the tested series of boards exposed to high temperature in comparison with the reference boards. Moreover, in the boards exposed to high temperature, a marked increase in the energy of AE events occurs during the bending test, whereby the registered events, by and large, come down to a single pulse induced by a brittle fracture. It is also demonstrated that the determination of the damaging effect of high temperature on the structure of fibre-cement boards solely on the basis of bending strength (MOR) is inadequate.
Numerical Analysis of Experimental Research in a Lightweight Floor System (LFS) with Heat Diffuser
Authors: Jacek Karpiesiuk , Chyży Tadeusz
Published: September 2022

The article presents the results of research on a lightweight floor system (LFS) with a heat diffuser made of metal lamellae. It differs from traditional layered floors in the absence of a screed layer, which reduces thermal inertia and predisposes it to be used with renewable energy sources. As part of the research, a real model of the floor, consisting of nine ceramic tiles, was made. Polyurethane adhesive was used to connect the individual layers of this composite. The model was subjected to a thermal action. It was constructed with the measuring equipment consisting of strain gauges. These were located at the boundaries of the composite layers and measured the material’s deformation. The measurement results were verified by numerical calculations. For this purpose, a computational model was made using FEM (finite element method). Comparable results of deformations were obtained (the differences did not exceed 6.1%), which made it possible to perform numerical calculations of light floor materials stresses. Additionally, the displacement of the tested model was measured and numerically verified. The results of these verifications can be useful not only in the heated/cooled LFS with aluminium lamellae, but also in other building partitions inside and outside the building.
Validation of Alternative Beam T-Junction Fem Models for Complex Tubular Structures
Authors: Badea Francisco , Olazagoitia JoseLuis , Perez JesusAngel
Published: September 2022

The finite element analysis of tubular structures is typically based on models constructed employing beam-type elements. This modeling technique provides a quick and computationally efficient option for calculation. Nevertheless, it shows a series of limitations related to the simplicity of this type of element, among which the inability of accounting for the stiffness behavior at the joint level is of notable importance when modeling complex tubular structures. Despite these limitations, the alternative of simulating complex tubular structures with shell- or volume-type elements is highly costly due to the complexity of the modeling process and the computational requirements. Previous research has proposed alternative beam models that improve the estimations when modeling these structures. These research validations were limited to simple models. This paper presents a validation process utilizing a previously developed beam T-junction model in a complex tubular structure, intended to be representative for buses’ and coaches’ upper structures. Results obtained reveal that the accuracy of beam element type models can be significantly improved with the adequate implementation of elastic elements to account for the real junction stiffness.
Performance Evaluation and Structure Optimization of Low-Emission Mixed Epoxy Asphalt Pavement
Authors: Fan Yulou , Wu You , Chen Huimin , Liu Shinan , Huang Wei , Wang Houzhi , Yang Jun
Published: September 2022

Epoxy asphalt concrete (EAC) has excellent properties such as high strength, outstanding thermal stability, and great fatigue resistance, and is considered to be a long-life pavement material. Meanwhile, the low initial viscosity of the epoxy components provides the possibility to reduce the mixing temperature of SBS-modified asphalt. The purpose of this study is to verify the feasibility of low-emission mixing of SBS-modified epoxy asphalt and to compare the mechanical responses in several typical structures with EAC, in order to perform structure optimization for practical applications of EAC. In this paper, the Brookfield rotational viscosity test was conducted to investigate the feasibility of mixing SBS-modified epoxy asphalt at a reduced temperature. Subsequently, the dynamic modulus tests were carried out on EAC to obtain the Prony series in order to provide viscoelastic parameters for the finite element model. Six feasible pavement structures with EAC were proposed, and a finite element method (FEM) model was developed to analyze and compare the mechanical responses with the conventional pavement structure. Additionally, the design life was predicted and compared to comprehensively evaluate the performance of EAC structures. Finally, life cycle assessment (LCA) on carbon emissions was developed to explore the emission reduction effect of the epoxy asphalt pavement. The results indicate that the addition of epoxy components could reduce the mixing temperature of SBS-modified asphalt by 30 °C. The proper use of EAC can significantly improve the mechanical condition of the pavement and improve its performance and service life. It is recommended to choose S5 (with EAC applied in the middle-lower layer) as the optimal pavement structure, whose allowable load repetitions to limit fatigue cracking were more than 1.7 times that of conventional pavements and it has favorable rutting resistance as well. The LCA results show that in a 25-year life cycle, the carbon emissions of epoxy asphalt pavements could be reduced by 29.8% in comparison to conventional pavements.
Charge-Convertible and Reduction-Sensitive Cholesterol-Containing Amphiphilic Copolymers for Improved Doxorubicin Delivery
Authors: Wang Zhao , Guo Xinyu , Hao Lingyun , Zhang Xiaojuan , Lin Qing , Sheng Ruilong
Published: September 2022

For achieving successful chemotherapy against cancer, designing biocompatible drug delivery systems (DDSs) with long circulation times, high cellular endocytosis efficiency, and targeted drug release is of upmost importance. Herein, a well-defined PEG-b-P(MASSChol-co-MANBoc) block copolymer bearing redox-sensitive cholesteryl-side group was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization (with non-redox PEG-b-P(MACCChol-co-MAN-DCA) as the reference), and 1,2-dicarboxylic-cyclohexene acid (DCA) was then grafted onto the hydrophobic block to endow it with charge-convertible characteristics under a tumor microenvironment. The amphiphilic copolymer could be assembled into polymeric spherical micelles (SSMCs) with polyethylene glycol (PEG) as the corona/shell, and anti-cancer drug doxorubicin (DOX) was successfully encapsulated into the micellar core via strong hydrophobic and electrostatic interactions. This nanocarrier showed high stability in the physiological environment and demonstrated “smart” surface charge conversion from negative to positive in the slightly acidic environment of tumor tissues (pH 6.5~6.8), as determined by dynamic light scattering (DLS). Moreover, the cleavage of a disulfide bond linking the cholesterol grafts under an intracellular redox environment (10 mM GSH) resulted in micellar dissociation and accelerated drug release, with the non-redox-responsive micelles (CCMCs) as the control. Additionally, a cellular endocytosis and tumor proliferation inhibition study against MCF-7 tumor cells demonstrated the enhanced endocytosis and tumor cell inhibitory efficiency of dual-responsive SSMCs/DOX nanomedicines, revealing potentials as multifunctional nanoplatforms for effective oncology treatment.
A Novel Sliding Mode Momentum Observer for Collaborative Robot Collision Detection
Authors: Long Shike , Dang Xuanju , Sun Shanlin , Wang Yongjun , Gui Mingzhen
Published: September 2022

Safety during physical human–robot interaction is the most basic requirement for robots. Collision detection without additional sensors is an economically feasible way to ensure it. In contrast, current collision detection approaches have an unavoidable trade-off between sensitivity to collisions, signal smoothness, and immunity to measurement noise. In this paper, we present a novel sliding mode momentum observer (NSOMO) for detecting collisions between robots and humans, including dynamic and quasistatic collisions. The collision detection method starts with a dynamic model of the robot and derives a generalized momentum-based state equation. Then a new reaching law is devised, based on which NSOMO is constructed by fusing momentum, achieving higher bandwidth and noise immunity of observation. Finally, a time-varying dynamic threshold (TVDT) model is designed to distinguish between collision signals and the estimated lumped disturbance. Its coefficients are obtained through offline data recognition. The TVDT with NSOMO enables fast and reliable collision detection and allows collision position assessment. Simulation experiments and hardware tests of the 7-DOF collaborative robot are implemented to illustrate this proposed method’s effectiveness.
Impact of Exogenous Nitric Oxide Treatment on Vascularization of a Subcutaneous Device for Cell Transplantation
Authors: Smink Alexandra M. , Ceballos Bryan , Koster Taco , Rodriquez Samuel , Alexander Michael , Lakey Jonathan R. T. , de Vos Paul
Published: September 2022

Subcutaneous polymer scaffolds have shown potential for creating an optimal transplantation site in cellular replacement therapy, e.g., when transplanting insulin-producing cells to cure type 1 diabetes. Imperative for these scaffolds is a high degree of vascularization to guarantee long-term functional cellular survival. In this study, the effect of the nitric oxide (NO) donor S-nitroso-N-acetyl-dl-penicillamine (SNAP) on the vascularization degree of a subcutaneous poly(d,l-lactide-co-ε-caprolactone) (PDLLCL) scaffold was investigated. To this end, scaffolds were implanted under the skin of C57BL/6 mice. Each mouse received a control scaffold and a scaffold containing SNAP. At day 7, 14, and 28, the oxygen percentage within the scaffolds was measured and at day 28, the vascularization degree was determined with lectin infusion and gene expression analysis. We measured lower oxygen percentages within the scaffolds containing the NO-donor up to day 14 compared to the control scaffolds, but no differences were found at day 28. Although blood vessels in the scaffolds were well perfused, no differences between the groups were found in the lectin staining and gene expression of vascular markers, such as CD31, CD105, and VEGFa. To conclude, in this biomaterial setting, addition of a NO-donor did not improve the vascularization degree of the subcutaneous scaffold.
Triggering of Valence Tautomeric Transitions in Dioxolene-Based Cobalt Complexes Influenced by Ligand Substituents, Co-ligands, and Anions
Authors: Sundaresan Sriram , Diehl Marcel , Carrella Luca M. , Rentschler Eva
Published: September 2022

We report the multistep synthesis of the 1,1′-(piperazine-1,4-diyl)bis(N,N-bis(pyridin-2-ylmethyl)methanamine)(Ltpbap) octadentate ligand, which, in combination with the known 3,5-di-tert-butylcatechol (3,5-dbcat), allowed the preparation of two di-nuclear cobalt complexes [Co2(Ltpbap)(3,5-dbcat)2](SO4)·5.5MeOH·2H2O (3a) and [Co2(Ltpbap)(3,5-dbcat)2 ](ClO4)2·1.5H2O (3b). We also report the synthesis of two mono-nuclear cobalt complexes [Co(3,5-dbsq)(3,5-dbcat)(4-Mepip)2] (1) with 4-Mepip being 4-methylpiperidine and (Hpip)[Co(tbcat)2(pip)2]·CH3CN (2) where Hpip denotes a piperidinium cation and tbcat is the tetra-bromocatechol ligand. The obtained complexes were characterized by single-crystal X-ray crystallography, SQUID magnetometry, and IR spectroscopy. The structure of the crystalline material in all the cases was determined at 173 K. The magnetic properties of all complexes were measured between 2 and 380 K. The magnetic data clearly show that mono-nuclear complex 1 and di-nuclear complex 3a exhibit valence tautomerism with onset around 300 K and 370 K, respectively, whereas the other two complexes 2 and 3b remain unchanged over the measured temperature range.
Counter Mode of the Shannon Block Cipher Based on MPF Defined over a Non-Commuting Group
Authors: Mihalkovich Aleksejus , Levinskas Matas , Sakalauskas Eligijus
Published: September 2022

In this paper, we present a counter mode of a Shannon block cipher based on the matrix power function. We make use of the matrix power function to define a single round symmetric cipher. Continuing our previous research, we implement a non-commuting group the order of which is a power of two in order to define a CTR mode in its most classic interpretation. We explore the security of the newly defined scheme, first, by showing that our block cipher is perfectly secure and does not leak any information about the initial plaintext based on the ciphertext. Then, we define a sequence of security games that show how the CTR mode of our cipher can resist all passive attacks.
The Correlation between Bone Density and Mechanical Variables in Bone Remodelling Models: Insights from a Case Study Corresponding to the Femur of a Healthy Adult
Authors: Calvo-Gallego José Luis , Gutiérrez-Millán Fernando , Ojeda Joaquín , Pérez María Ángeles , Martínez-Reina Javier
Published: September 2022

Bone remodelling models (BRM) are often used to estimate the density distribution in bones from the loads they are subjected to. BRM define a relationship between a certain variable measuring the mechanical stimulus at each bone site and either the local density or the local variation of density. This agrees with the Mechanostat Theory, which establishes that overloaded bones increase their density, while disused bones tend to decrease their density. Many variables have been proposed as mechanical stimuli, with stress or strain energy density (SED) being some of the most common. Yet, no compelling reason has been given to justify the choice of any of these variables. This work proposes a set of variables derived from the local stress and strain tensors as candidates for mechanical stimuli; then, this work correlates them to the density in the femur of one individual. The stress and strain tensors were obtained from a FE model and the density was obtained from a CT-scan, both belonging to the same individual. The variables that best correlate with density are the stresses. Strains are quite uniform across the femur and very poorly correlated with density, as is the SED, which is, therefore, not a good variable to measure the mechanical stimulus.
Intelligent Multi-Strategy Hybrid Fuzzy K-Nearest Neighbor Using Improved Hybrid Sine Cosine Algorithm
Authors: Zheng Chengfeng , Kasihmuddin Mohd Shareduwan Mohd , Mansor Mohd. Asyraf , Chen Ju , Guo Yueling
Published: September 2022

The sine and cosine algorithm is a new simple and effective population optimization method proposed in recent years that has been studied in many works of literature. Based on the basic principle of the sine and cosine algorithm, this paper fully studies the main parameters affecting the performance of the sine and cosine algorithm, integrates the reverse learning algorithm, adds an elite opposition solution and forms the hybrid sine and cosine algorithm (hybrid SCA). Combined with the fuzzy k-nearest neighbor method and the hybrid SCA, this paper numerically simulates two-class datasets and multi-class datasets, obtains a large number of numerical results and analyzes the results. The hybrid SCA FKNN proposed in this paper has achieved good accuracy in classification and prediction results under 10 different types of data sets. Compared with SCA FKNN, LSCA FKNN, BA FKNN, PSO FKNN and SSA FKNN, the prediction accuracy is significantly improved. In the Wilcoxon signed rank test with SCA FKNN and LSCA FKNN, the zero hypothesis (significance level 0.05) is rejected and the two classifiers have a significantly different accuracy.
The Optimal Balance between Oncolytic Viruses and Natural Killer Cells: A Mathematical Approach
Authors: Kim Dongwook , Shin Dong-Hoon , Sung Chang K.
Published: September 2022

Oncolytic virotherapy (OV) is a cancer therapy utilizing lytic viruses that specifically target cancer cells for elimination. In this relatively new therapy, two contradictory observations have been made. Some studies showed that immune responses including activated natural killer (NK) cells post oncolytic viral infection increased the cancer cell death, while others reported that such initial immune responses diminished the anti-tumor efficacy, which was caused by premature viral clearance. In this paper, we present a mathematical model to investigate the effect of NK cells on oncolytic virotherapy. Particularly, we focused on the minimum condition for NK cells to be activated in terms of parameters and how the activation of NK cells interacts and changes the dynamics among cancer, infected cancer cells and oncolytic virus. Analytic works for the existence and stability conditions of equilibrium points are provided. Numerical results are in good agreement with analytic solutions. Our numerical results show that equilibrium points can be created or destroyed by the activation of NK cells in a dynamical system and suggest that the balance between the bursting rate of the virus and the activation rate of NK cells is a crucial factor for successful OV therapy.
Partial Anti-Synchronization Problem of the 4D Financial Hyper-Chaotic System with Periodically External Disturbance
Authors: Cao Lin , Guo Rongwei
Published: September 2022

This paper is concerned with the partial anti-synchronization of the 4D financial hyper-chaotic system with periodically external disturbance. Firstly, the existence of the partial anti-synchronization problem for the nominal 4D financial system is proven. Then, a suitable filter is presented, by which the periodically external disturbance is asymptotically estimated. Moreover, two disturbance estimator (DE)-based controllers are designed to realize the partial anti-synchronization problem of such a system. Finally, numerical simulation verifies the effectiveness and correctness of the proposed results.
New Extensions of the Parameterized Inequalities Based on Riemann–Liouville Fractional Integrals
Authors: Kara Hasan , Budak Hüseyin , Hezenci Fatih
Published: September 2022

In this article, we derive the above and below bounds for parameterized-type inequalities using the Riemann–Liouville fractional integral operators and limited second derivative mappings. These established inequalities generalized the midpoint-type, trapezoid-type, Simpson-type, and Bullen-type inequalities according to the specific choices of the parameter. Thus, a generalization of many inequalities and new results were obtained. Moreover, some examples of obtained inequalities are given for better understanding by the reader. Furthermore, the theoretical results are supported by graphs in order to illustrate the accuracy of each of the inequalities obtained according to the specific choices of the parameter.
A Predator–Prey Model with Beddington–DeAngelis Functional Response and Multiple Delays in Deterministic and Stochastic Environments
Authors: Shao Yuanfu , Kong Weili
Published: September 2022

In view of prey’s delayed fear due to predators, delayed predator gestation, and the significance of intra-specific competition between predators when their populations are sufficiently large, a prey–predator population model with a density-dependent functional response is established in a deterministic environment. We research the existence and asymptotic stability of the equilibrium statuses. Then, taking into consideration environmental disturbances, we extend the deterministic model to a stochastic model and research the existence and stationary distributions of stochastic solutions. Finally, we perform some numerical simulations to verify the theoretical results. Numerical examples indicate that fear, delays and environmental disturbance play crucial roles in the system stability of the equilibrium status.
On Comprehension of Genetic Programming Solutions: A Controlled Experiment on Semantic Inference
Authors: Slivnik Boštjan , Kovačević Željko , Mernik Marjan , Kosar Tomaž
Published: September 2022

Applied to the problem of automatic program generation, Genetic Programming often produces code bloat, or unexpected solutions that are, according to common belief, difficult to comprehend. To study the comprehensibility of the code produced by Genetic Programming, attribute grammars obtained by Genetic Programming-based semantic inference were compared to manually written ones. According to the established procedure, the research was carried out as a controlled classroom experiment that involved two groups of students from two universities, and consisted of a background questionnaire, two tests and a feedback questionnaire after each test. The tasks included in the tests required the identification of various properties of attributes and grammars, the identification of the correct attribute grammar from a list of choices, or correcting a semantic rule in an attribute grammar. It was established that solutions automatically generated by Genetic Programming in the field of semantic inference, in this study attribute grammars, are indeed significantly harder to comprehend than manually written ones. This finding holds, regardless of whether comprehension correctness, i.e., how many attribute grammars were correctly comprehended, or comprehension efficiency is considered, i.e., how quickly attribute grammars were correctly comprehended.
A Comparison of Dinoflagellate Thiolation Domain Binding Proteins Using In Vitro and Molecular Methods
Authors: Williams Ernest , Bachvaroff Tsvetan , Place Allen
Published: September 2022

Dinoflagellates play important roles in ecosystems as primary producers and consumers making natural products that can benefit or harm environmental and human health but are also potential therapeutics with unique chemistries. Annotations of dinoflagellate genes have been hampered by large genomes with many gene copies that reduce the reliability of transcriptomics, quantitative PCR, and targeted knockouts. This study aimed to functionally characterize dinoflagellate proteins by testing their interactions through in vitro assays. Specifically, nine Amphidinium carterae thiolation domains that scaffold natural product synthesis were substituted into an indigoidine synthesizing gene from the bacterium Streptomyces lavendulae and exposed to three A. carterae phosphopantetheinyl transferases that activate synthesis. Unsurprisingly, several of the dinoflagellate versions inhibited the ability to synthesize indigoidine despite being successfully phosphopantetheinated. However, all the transferases were able to phosphopantetheinate all the thiolation domains nearly equally, defying the canon that transferases participate in segregated processes via binding specificity. Moreover, two of the transferases were expressed during growth in alternating patterns while the final transferase was only observed as a breakdown product common to all three. The broad substrate recognition and compensatory expression shown here help explain why phosphopantetheinyl transferases are lost throughout dinoflagellate evolution without a loss in a biochemical process.
Obesity as a Risk Factor for Venous Thromboembolism Recurrence: A Systematic Review
Authors: Ntinopoulou Pinelopi , Ntinopoulou Erato , Papathanasiou Ioanna V. , Fradelos Evangelos C. , Kotsiou Ourania , Roussas Nikolaos , Raptis Dimitrios G. , Gourgoulianis Konstantinos I. , Malli Foteini
Published: September 2022

Background and Objectives: Venous thromboembolism (VTE) encompasses Deep Venous Thrombosis (DVT) and Pulmonary Embolism (PE). The duration of anticoagulant therapy following a VTE event partly relies on the risk of recurrent VTE which depends on the clinical setting where VTE occurred and the VTE risk factors present. Obesity is considered a minor risk factor and studies in the literature have provided conflicting results on whether obesity influences the development of recurrences. The aim of the present study is to assess the effect of obesity on VTE recurrence in patients that suffered from a previous VTE event. Materials and Methods: We conducted systematic research for English language studies in Medline, Scopus and ProQuest databases in order to identify publications that assess the risk of VTE recurrence in obesity. Inclusion criteria were: 1. Diagnosis of VTE, 2. Definition of obesity as a body mass index ≥30 kg/m2, 3. Report of the risk of obesity on VTE recurrence, 4. Adult human population. We did not include case reports, review studies or studies that assessed other forms of thrombosis and/or used other definitions of obesity. We used the Newcastle-Ottawa scale to address the quality of the studies. Results: Twenty studies were included in the analysis, of which 11 where prospective cohort studies, 6 were retrospective cohort studies, 1 was a cross-sectional study, and 2 were post-hoc analysis of randomized clinical trials. Obesity was significantly associated with recurrences in 9 studies and in 3 of them the association was significant only in females. Conclusions: There is heterogeneity between the studies both in their design and results, therefore the effect of obesity on VTE recurrence cannot be adequately estimated. Future randomized clinical studies with appropriately selected population are needed in order to streamline the effect of obesity on VTE recurrence.
Management of Advanced Pancreatic Cancer through Stromal Depletion and Immune Modulation
Authors: Liu Tiantong , Cheng Sihang , Xu Qiang , Wang Zhiwei
Published: September 2022

Pancreatic cancer is one of the leading causes of cancer-related deaths worldwide. Unfortunately, therapeutic gains in the treatment of other cancers have not successfully translated to pancreatic cancer treatments. Management of pancreatic cancer is difficult due to the lack of effective therapies and the rapid development of drug resistance. The cytotoxic agent gemcitabine has historically been the first-line treatment, but combinations of other immunomodulating and stroma-depleting drugs are currently undergoing clinical testing. Moreover, the treatment of pancreatic cancer is complicated by its heterogeneity: analysis of genomic alterations and expression patterns has led to the definition of multiple subtypes, but their usefulness in the clinical setting is limited by inter-tumoral and inter-personal variability. In addition, various cell types in the tumor microenvironment exert immunosuppressive effects that worsen prognosis. In this review, we discuss current perceptions of molecular features and the tumor microenvironment in pancreatic cancer, and we summarize emerging drug options that can complement traditional chemotherapies.