bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Evaluation of Biomimetic 3D Coated Composite Scaffold for Application as Skin Substitutes
Authors: Liu Sui‐Hong , Zhang Hai‐Guang , Hu Qing‐Xi , Wang Ben , Li Shuai , Zhang Chuck 
Published: February 2020

AbstractSkin injuries are an urgent health issue, which raises a great concern in the clinic. Although numerous strategies have been proposed to fabricate skin substitutes for treatment of wounds over the past several decades, fabricating an ideal skin substitute to replace the damaged one can still be a problem. In this study, a novel biomimetic 3D composite skin scaffold is fabricated by combining electrohydrodynamic (EHD) jetting, electrospinning, and coating techniques. Here, the first polycaprolactone (PCL) porous structure is produced by the EHD jetting. Next, the second polylactic acid (PLA) membrane consisted of nanoscale fibers is prepared on the PCL porous structure via the electrospinning. The PCL porous structure and PLA fibers membrane can mimic the dermis and epidermis layer, respectively. Furthermore, gelatin is used as coating solution to enhance the biocompatibility of the scaffold. The structure and morphology of the fabricated scaffolds are analyzed, and the mechanical properties are investigated as well. Moreover, the in vitro and in vivo experiments demonstrate the biocompatibility of the materials and the fabrication process. In conclusion, these results demonstrate that the composite scaffold is effective and holds great potential for skin regeneration in the clinic.
Ionic Strength and Thermal Dual‐Responsive Bilayer Hollow Spherical Hydrogel Actuator
Authors: Zhou Shengzhu , Wu Baoyi , Zhou Qiang , Jian Yukun , Le Xiaoxia , Lu Huanhuan , Zhang Dachuan , Zhang Jiawei , Zhang Zhihui , Chen Tao 
Published: February 2020

AbstractAs one of the most promising intelligent materials, polymeric hydrogel actuators could produce reversible shape change upon external stimuli. Although complex shape deformation from 2D to 3D have been achieved, the realization of actuating behavior from 3D to 3D is still a significant challenge. Herein, an effective strategy to develop a novel bilayer hollow spherical hydrogel actuator is proposed. Through immersing a Ca2+ incorporated gelatin core into alginate solution, an ionic‐strength‐responsive alginate layer will be formed along the gelatin core via alginate–Ca2+ crosslinks, and then another thermo‐responsive alginate‐poly(2‐(dimethylamino)ethyl methacrylate)(Alg‐PDMAEMA) layer is introduced to achieve a bilayer hydrogel with ionic strength and temperature dual responsiveness. A hollow hydrogel capsule could be obtained if a spherical gelatin core is applied, and it could produce complex shape deformations from 3D to 3D upon the trigger of ionic strength and temperatures changes. The present work may offer new inspirations for the development of novel intelligent polymeric hydrogel actuators.
Tensile Mechanical Behavior and Bioactivity of PLA/PCL Biopolyester Threads for Suture
Authors: Catauro Michelina , Scolaro Cristina , Barrino Federico , Visco Annamaria 
Published: February 2020

AbstractIn this paper the mechanical tensile static test of threads both in o‐knot of blends made by two biopolyesters, polylactic acid (PLA) and poly(ɛ‐caprolactone) (PCL), compatibilized with a triisocyanate (T) in a low amount (1 phr, per hundred resin), and high amount, 5 phr, is performed. The highest mechanical strength of the PLA/PCL/T threads is of about 30 MPa. PLA, PCL, and T are mixed in a twin extruder and the resulting blend is spinnable by a melt spinning process in order to produce thin threads of about 0.3 mm diameter. Compatibilizing filler improves the mechanical performance of the PLA/PCL blend for the chemical branching and/or cross‐linking reactions induced among the two typically immiscible biopolyesters. Chemical reactions link PLA with PCL, whose macromolecular structure complexity grows with the filler load. Blended biopolymers can be considered promising biomaterials because they seem to be bioactive and able to inhibit bacterial growth.
Organic Inorganic Hybrid Materials Synthesized via Sol–Gel for Controlled Drug Delivery
Authors: Bollino Flavia , Catauro Michelina 
Published: February 2020

AbstractThe aim of the present work is the synthesis of organic–inorganic hybrid (OIH) materials by means of the sol–gel technique for controlled release of anti‐inflammatory agents. The investigated materials consist of a silica (SiO2)–poly(ε‐caprolactone) (PCL) OIH in which indomethacin (SiO2/PCL/IND) or ketoprofen (SiO2/PCL/KET) are embedded. Two OIH matrices are prepared by adding 6 and 12 wt% of PCL, respectively. Scanning electron microscopy (SEM) confirms that all the synthesized samples are OIHs. Moreover, the bioactivity of the materials is evaluated verifying the hydroxyapatite present on their surfaces by SEM microscopy, after soaking in a simulated body fluid (SBF) solution. Subsequently, the release kinetic of the two drugs from the SiO2/PCL matrix is studied recording the amount of drug released in SBF with the time by means of UV–vis spectroscopy. The results show that the drug release depends on the PCL content and the drug molecule structure.
Study of Bioactive Materials Containing New Complex of Iron(II) Citrate
Authors: Gallo Monica , Barrino Federico , Blanco Ignazio , Poggetto Giovanni Dal , Ciaravolo Martina , Naviglio Daniele 
Published: February 2020

AbstractIron is an essential trace element for animals, in fact the human body is not able to produce iron independently and for this reason it must be obtained by dietary intake. Generally, with proper nutrition and intact intestinal flora, the required dose of iron can be taken through food. However, in case of deficiency, it is necessary to resort to the use of specific dietary supplements and in more serious cases, to a targeted drug therapy that is based on venous injection of iron compounds. The purpose of this work is to develop a bioactive material capable of releasing ferrous ions in a controlled manner. Therefore, a new iron(II) citrate complex is synthesized by a redox reaction between iron and citric acid. Subsequently, the complex obtained is subjected to a series of chemical analyses for its characterization and to RX diffraction to assess crystallinity of solid. Moreover, it is incorporated in a SiO2 matrix in different weight percentages, by means of a sol–gel pathway, to achieve a controlled release system of iron. Finally, a bioactivity test is performed in a simulated body fluid to assess its potential efficacy, using Fourier transform infrared spectroscopy and scanning electron microscopy analysis.
Magnetosensitive Water‐Soluble Nanocomposite Based on Sodium Alginate and Fe2O3 Nanoparticles
Authors: Spiridonov Vasily , Panova Irina , Antonova Yulia , Makarova Lyudmila , Zezin Sergey , Yaroslavov Alexander 
Published: February 2020

AbstractMagnetic nanocomposite based on maghemite nanoparticles and a natural polysaccharide, sodium alginate, is synthesized. Nanocomposite is characterized by spectrophotometry, transmission electron microscopy, X‐ray diffraction, and dynamic light scattering. The obtained composite demonstrates the high aggregative stability. An external magnetic field causes the nanocomposites to move in an aqueous dispersion.
Mechanical Performance of Polyethylene Joints Based on Nanocomposites Doped with Titanium Dioxide
Authors: Catauro Michelina , Scolaro Cristina , Visco Annamaria 
Published: February 2020

AbstractTwo sheets of polyethylene (biomedical type) are welded by a diode laser; one of the two layers is doped with titanium dioxide nanoparticles at different concentrations in order to enhance the absorption coefficient at the laser wavelength. The doped nanocomposite plastic has the typical white color of pure polyethylene. Single‐lap geometries are stressed by means of mechanical static lap shear and hardness tests in order to check the change induced by laser energy absorption and choose the best filler amount. These polymeric joints can be useful in biomedical field for the special features of the ultra‐high‐molecular‐weight polyethylene and for the particular advantages of high sealing precision required in medical devices.
Analysis of Hip Prostheses Materials Properties
Authors: Cotoros Diana , Druga Corneliu , Stanciu Anca 
Published: February 2020

AbstractThe most frequent reason for replacing a hip prosthesis is the aseptic loss of an implant component, with or without osteolysis. As around 93% of the arthroplasties (e.g., in Sweden) are cemented and it can be concluded that aseptic mobilization is the most frequent cause of damaging in cemented implants. Aseptic mobilizations often indicate poor shear resistance or a faulty interface between the cement and the components or catastrophic wear as a result of high debris production (from cement, metal, or polyethylene), which together with the hydraulic effects of the joint lead to osteolysis. As a follow up, the end users (medical staff and patients) need to be sure that the bone cements are fit for purpose. Considering the abovementioned issues, the paper concerns the analysis of cement and hip implant component behavior for the most used materials in hip arthroplasties in order to provide end users with a reliable tool in materials testing.
Tribological Modeling of the Hip Joint
Authors: Braun Barbu Cristian , Drugă Corneliu Nicolae , Şerban Ionel , Cotoros Diana , Radu Necula 
Published: February 2020

AbstractThe paper presents a series of aspects regarding the main biotribological phenomena occurring in the synovial joints. Although a great deal of research is carried out around the world about the biotribological processes in the human body's synovial joints, due to their complexity, they are not yet been fully understood and cannot establish a unique model of lubrication mechanism in these joints. The problem is complicated by the fact that in reality the cartilage is neither homogeneous nor isotropic and undergoes a large deformation during loading. According to several researchers, implantation and expulsion of synovial fluid in cartilage is not a simple phenomenon, although the boosted or weeping type of lubrication suggests this. The self‐generating lubrication mechanism postulated by Mow et al. (1987) takes into account the biphasic nature of cartilage and is based on the load‐dividing factor between the solid phase and the liquid. In recent years, studies have also been carried out to explore possible links between synovial joint lubrication mechanisms and degeneration processes. Tribological modeling is based on a number of parameters, such as: lubricant film thickness (or synovial fluid), maximum physiological load, articular cartilage surface roughness, friction coefficient, surface roughness, and lubrication regime.
Algorithm for Micro‐Profiling from Image of the Injection Molds Complex Surfaces
Authors: Serban Daniiel , Opran Constantin Gheorghe 
Published: February 2020

AbstractNature is an excellent source of inspiration. Understanding nature can lead to new discoveries of new materials, applications, products. Scientists have found out technologies that seek to mimic some of life's unique innovations. In Germany researchers have developed a synthetic shark skin made of elastic silicone that reduces bio‐fouling. Engineers from the Massachusetts Institute of Technology have developed some “biomimicry” material out of glass and plastic that collects minute amounts of water, just like the Namib Desert beetle's back. Polymer composites are used for a very good replication of the mold cavities surface microstructures. Transformation of image to surface could be an economical solution for machining the injection mold cavities for mimic the inspiration source. In this paper an algorithm for combining the tool paths obtained on an image‐to‐surface technique with the tool paths on a complex shaped cavity is presented. The algorithm is tested by micro‐milling an injection mold surface of a cavity for a scale model stone wall and the injection molding experiments have proven the high quality of detail replication.
Composite Parts Assembly Operational Improvements
Authors: Greco Alessandro , Caputo Francesco , Caterino Mario , D'Ambra Sara , Fera Marcello , Laudante Elena 
Published: February 2020

AbstractIn the era of Industry 4.0, automation plays a key role in improving manufacturing production processes in terms of working times, accuracy of operations, products’ quality, and so on. With focus on the working tasks on composite components, drilling and riveting operations require particular attention due to the possibility of damage to the final product, especially when they are executed manually. To reduce these kinds of risks, the introduction of a robot in the working area could represent an improvement to speed up the processes and to ensure a better quality result. It is worth noting that human intervention remains necessary for carrying out a part of the sub‐tasks, especially in the case of composite assembly procedures. This paper aims at presenting a case study about the drilling and riveting operations on a composite aircraft fuselage whose working cell is characterized by the coexistence of a human and a robot. Moreover, the implementation of a numerical simulation allows validating the working cycle and the adopted solutions in terms of ergonomic performance.
Some Considerations on the Composite Structure of the Human Eye
Authors: Lazar Alexandra Maria , Baritz Mihaela Ioana 
Published: February 2020

AbstractThe construction of the human eyeball has characteristics of the composite structure considering the optically transparent media (cornea, crystalline) that participate in the formation of images on the surface of the retina. Both the cornea and the crystalline are formed by thin cellular layers that behave like structures composed of elastic curved plates. The first part of the article presents the theoretical aspects that are the basis of the biomechanical approach of this ensemble. In the second part, the aspects of the modeling of the optical behavior of the eyeball and elasticity of the lens are presented. The final part of the article presents the conclusions regarding the behavior of the composite structure of the ocular globe from a biomechanical and optical point of view.
Some Aspects Regarding the Construction of a Portable Perimeter Made by Composite Materials
Authors: Gabriela Apostoaie Mirela 
Published: February 2020

AbstractThe visual field is one of the decisive factors in detecting the degree of visual defect. Testing it at all ages is essential due to the possibility of the appearance of different visual field defects from an early age. The current devices reduce the testing possibilities due to the very large dimensions and weight. The use of composite materials for the design of this type of devices allows the construction of devices that are easier and more accessible as portability.
Research Regarding Development of Expert Systems for Polymeric Products Design and Manufacturing
Authors: Vulpes Tiberiu Cristian , Opran Constantin Gheorghe 
Published: February 2020

AbstractPolymeric products design and manufacturing is a complex industrial process that combines elements of chemical composition of plastics with injection modeling technology designed to optimize economic and technical parameters. A number of risks can disrupt the proper execution of the works and consequently alter the technical and economic objectives. In this paper the results of research regarding expert system for polymeric products design and manufacturing are presented. This system determines the level of risk of the different execution stages by risk identification and qualitative assessment through a series of predefined questions and hypothetical answers.
Relaxation Time Spectrum and Dynamics of Stretched Polymer Chain in Dilute θ Solution: Implicit Solvent Model versus Explicit Solvent Model
Authors: Yao Ning , Li Jiangtao , Gu Fang , Wang Haijun , Liao Qi 
Published: February 2020

AbstractRelaxation dynamics of a single stretched polymer chain after releasing the two fixed ends in dilute solutions are investigated by using implicit solvent and explicit solvent molecular dynamic simulations. The phase diagram of polymer in explicit solvent solution is determined, and the θ point is estimated by the form factor of the polymer chain. The relaxation time spectrum is obtained by the inverse Laplace transform of length–time decay curves of the relaxation process. The dependencies of the longest relaxation time in the spectrum on the chain length are compared with the scaling prediction of the Rouse model and the Zimm model of flexible chains. In this paper, it is confirmed that the dynamical scaling analysis of theoretical models are in good agreement with the simulation models in all range of polymerization degree of chain studied. The coarse‐grained explicit solvent simulation model of polymer chain in dilute solution developed in this paper can be a good numerical model for the future study of the dynamics process of macromolecules with hydrodynamic interactions in solutions.
A novel topology optimization formulation for enhancing fracture resistance with a single quasi‐brittle material
Authors: Russ Jonathan B. , Waisman Haim 
Published: February 2020

SummaryOptimal design of structures for fracture resistance is a challenging subject. This appears to be largely due to the strongly nonlinear governing equations associated with explicitly modeling fracture propagation. We propose a topology optimization formulation, in which low weight structures are obtained with significantly increased resistance to brittle fracture, in which crack propagation is explicitly modeled with the phase field approach. By contrast to our previous work, several important features are included which greatly assist the optimizer in dealing with the strongly discontinuous brittle fracture process, including a new objective function, which provides additional path information to the optimizer. Increased local control of the topology is introduced via a smoothed threshold function in the phase field fracture formulation and a constraint relaxation continuation scheme is proposed to alleviate some difficulty during the initial optimization iterations. The derivation of the analytical, path‐dependent sensitivities for the relevant functions is provided and the results from two benchmark numerical examples are presented which demonstrate the effectiveness of the proposed method.
The impact of climate change on maize yields and its variability in Telangana, India: A panel approach study
Authors: Guntukula Raju , Goyari Phanindra 
Published: February 2020

AbstractThe present study explores the effect of climate change on maize yields and its variance in Telangana utilizing Just–Pope production function, spanning the period 1956–2015. The three‐step feasible generalized least squares (FGLS) method is employed to estimate the Just and Pope production function. The empirical results of the work reveal that the average minimum temperature has a significant unfavorable effect on maize yield in Telangana. Maximum temperature and actual rainfall are positively related with maize yield; however, the maximum temperature is not statistically significant. Furthermore, rainfall and minimum temperature are risk‐shrinking factors, but the maximum temperature is a risk‐enhancing factor for maize yields during the study period. The study results have key implications for developing suitable local level adaptation policies in Telangana.
A novel plasmid–Escherichia coli system produces large batch dsRNAs for insect gene silencing
Authors: Ma Zhong‐Zheng , Zhou Hang , Wei Yan‐Long , Yan Shuo , Shen Jie 
Published: February 2020

AbstractBACKGROUNDRNA interference (RNAi)‐based pest management requires efficient delivery and large‐batch production of double‐stranded (ds)RNA. We previously developed a nanocarrier‐mediated dsRNA delivery system that could penetrate an insect's body and efficiently silence gene expression. However, there is a great need to improve the plasmid–Escherichia coli system for the mass production of dsRNA. Here, for efficient dsRNA production, we removed the rnc gene encoding endoribonuclease RNase III in E. coli BL21(DE3) and matched with the RNAi expression vector containing a single T7 promoter.RESULTSThe novel pET28‐BL21(DE3) RNase III‐system was successfully constructed to express vestigial (vg)‐dsRNA against Harmonia axyridis. dsRNA was extracted and purified from cell cultures in four E. coil systems, and the yields of dsRNA in pET28‐BL21(DE3) RNase III‐, pET28‐HT115(DE3), L4440‐BL21(DE3) RNase III‐ and L4440‐HT115(DE3) were 4.23, 2.75, 0.88 and 1.30 μg mL−1 respectively. The dsRNA expression efficiency of our novel E. coil system was three times that of L4440‐HT115(DE3), a widely used dsRNA production system. The RNAi efficiency of dsRNA produced by our system and by biochemical synthesis was comparable when injected into Harmonia axyridis.CONCLUSIONOur system expressed dsRNA more efficiently than the widely used L4440‐HT115(DE3) system, and the produced dsRNA showed a high gene‐silencing effect. Notably, our pET28‐BL21(DE3) RNase III‐system provides a novel method for the mass production of dsRNA at low cost and high efficiency, which may promote gene function analysis and RNAi‐based pest management. © 2020 Society of Chemical Industry
Implementing a globally harmonized risk assessment‐based approach for regulatory decision‐making of crop protection products
Authors: Wolf Douglas C , Aggarwal Manoj , Battalora Michael , Blacker Ann , Catalano Shadia I , Cazarin Karen , Lautenschalaeger Daniele , Pais Mariana C , Rodríguez Mauricio , Rupprecht Kent , Serex Tessa L , Mehta Jyotigna 
Published: February 2020

AbstractA global, harmonized evaluation system for crop protection chemicals based on exposure and risk will improve the ability to inform risk management decisions and better support innovation. This would be achieved through harmonized risk assessment‐based regulatory decision‐making realized through the application of the best available science, via integration of new methods and traditional data to create tailored exposure‐driven risk assessments. A requirement to achieve success is a structure that encourages direct communication between the regulatory community and the regulated industry, which would enable a more rapid incorporation of new technologies and advancing science. An approach that emulates the International Conference of Harmonization (ICH) for pharmaceuticals would bring together regulatory authorities and the regulated industry along with relevant experts from academia and Non‐Governmental Organizations to discuss scientific and technical advances and their implementation. These discussions would also encourage the elimination of outmoded practices that no longer serve a purpose resulting in more uniform testing requirements and best practices for data evaluation to support safe use and scientifically defensible human health and environmental risk assessments. New and developing technologies offer exciting opportunities to improve the current toxicity testing paradigms to provide better solutions and diminish animal testing. Implementation of a harmonized approach will increase the speed, efficiency and accuracy of regulatory decision‐making for human health and environmental protection while increasing the efficiency of providing safe and effective innovative products to the agriculture community. © 2020 Society of Chemical Industry