bluuebunny/crossref_metadata_2025 huggingface dataset:
Intracellular Delivery of Anti-SMC2 Antibodies against Cancer Stem Cells
Authors: Montero Sara , Seras-Franzoso Joaquin , Andrade Fernanda , Martinez-Trucharte Francesc , Vilar-Hernández Mireia , Quesada Manuel , Xandri Helena , Arango Diego , Abasolo Ibane , Rafael Diana , Schwartz Simo
Published: February 2020

Structural maintenance of chromosomes protein 2 (SMC2) is a central component of the condensin complex involved in DNA supercoiling, an essential process for embryonic stem cell survival. SMC2 over-expression has been related with tumorigenesis and cancer malignancy and its inhibition is regarded as a potential therapeutic strategy even though no drugs are currently available. Here, we propose to inhibit SMC2 by intracellular delivery of specific antibodies against the SMC2 protein. This strategy aims to reduce cancer malignancy by targeting cancer stem cells (CSC), the tumoral subpopulation responsible of tumor recurrence and metastasis. In order to prevent degradation and improve cellular internalization, anti-SMC2 antibodies (Ab-SMC2) were delivered by polymeric micelles (PM) based on Pluronic® F127 amphiphilic polymers. Importantly, scaffolding the Ab-SMC2 onto nanoparticles allowed its cellular internalization and highly increased its efficacy in terms of cytotoxicity and inhibition of tumorsphere formation in MDA-MB-231 and HCT116 breast and colon cancer cell lines, respectively. Moreover, in the case of the HCT116 cell line G1, cell-cycle arrest was also observed. In contrast, no effects from free Ab-SMC2 were detected in any case. Further, combination therapy of anti-SMC2 micelles with paclitaxel (PTX) and 5-Fluorouracil (5-FU) was also explored. For this, PTX and 5-FU were respectively loaded into an anti-SMC2 decorated PM. The efficacy of both encapsulated drugs was higher than their free forms in both the HCT116 and MDA-MB-231 cell lines. Remarkably, micelles loaded with Ab-SMC2 and PTX showed the highest efficacy in terms of inhibition of tumorsphere formation in HCT116 cells. Accordingly, our data clearly suggest an effective intracellular release of antibodies targeting SMC2 in these cell models and, further, strong cytotoxicity against CSC, alone and in combined treatments with Standard-of-Care drugs.
A Proof-of-Concept Study on the Therapeutic Potential of Au Nanoparticles Radiolabeled with the Alpha-Emitter Actinium-225
Authors: Salvanou Evangelia-Alexandra , Stellas Dimitris , Tsoukalas Charalampos , Mavroidi Barbara , Paravatou-Petsotas Maria , Kalogeropoulos Nikolaos , Xanthopoulos Stavros , Denat Franck , Laurent Gautier , Bazzi Rana , Roux Stephane , Bouziotis Penelope
Published: February 2020

Actinium-225 (225Ac) is receiving increased attention for its application in targeted radionuclide therapy, due to the short range of its emitted alpha particles in conjunction with their high linear energy transfer, which lead to the eradication of tumor cells while sparing neighboring healthy tissue. The objective of our study was the evaluation of a gold nanoparticle radiolabeled with 225Ac as an injectable radiopharmaceutical form of brachytherapy for local radiation treatment of cancer. Au@TADOTAGA was radiolabeled with 225Ac at pH 5.6 (30 min at 70 °C), and in vitro stability was evaluated. In vitro cytotoxicity was assessed in U-87 MG cancer cells, and in vivo biodistribution was performed by intravenous and intratumoral administration of [225Ac]225Ac-Au@TADOTAGA in U-87 MG tumor-bearing mice. A preliminary study to assess therapeutic efficacy of the intratumorally-injected radio-nanomedicine was performed over a period of 22 days, while the necrotic effect on tumors was evaluated by a histopathology study. We have shown that [225Ac]225Ac-Au@TADOTAGA resulted in the retardation of tumor growth after its intratumoral injection in U87MG tumor-bearing mice, even though very low activities were injected per mouse. This gold nanoparticle radiopharmaceutical could be applied as an unconventional brachytherapy in injectable form for local radiation treatment of cancer.
Does the Polypill Improve Patient Adherence Compared to Its Individual Formulations? A Systematic Review
Authors: Baumgartner Ana , Drame Katarina , Geutjens Stijn , Airaksinen Marja
Published: February 2020

Many patients, especially those with a high pill burden and multiple chronic illnesses, are less adherent to medication. In medication treatments utilizing polypills, this problem might be diminished since multiple drugs are fused into one formulation and, therefore, the therapy regimen is simplified. This systematic review summarized evidence to assess the effect of polypills on medication adherence. The following databases were searched for articles published between 1 January 2000, and 14 May 2019: PubMed, Web of Science, Cochrane Library, and Scopus. Medication adherence was the only outcome assessed, regardless of the method of measuring it. Sixty-seven original peer-reviewed articles were selected. Adherence to polypill regimens was significantly higher in 56 articles (84%) compared to multiple pill regimens. This finding was also supported by the results of 13 out of 17 selected previously published systematic reviews and meta-analyses dealing with this topic. Adherence can be improved through the formulation of polypills, which is probably why the interest in researching them is growing. There are many polypills on the market, but the adherence studies so far focused mainly on a small range of medical conditions.
Quantitative and Qualitative Genetic Studies of Some Acacia Species Grown in Egypt
Authors: Abdelsalam Nader R. , Ali Hayssam M. , Salem Mohamed Z. M. , El-Wakil Hosam E.
Published: February 2020

The objective of the current work is to study the genetic differentiation between Acacia species growing in Egypt as plant genetic resources based on morphological, biochemical, and molecular markers. The 20 replicates of Acacia tree collected from four localities from Egypt were A. tortilis ssp. raddiana and A. farnesiana (Siwa Oasis and Borg El-Arab City), A. stenophylla, A. sclerosperma (Marsa Matroh City), and A. saligna (Abis Station Farm, Alexandria). The results based on the previous markers indicated highly significant differences between Acacia species, confirming the hypothesis of the possibility of using morphological, biochemical, and molecular parameters in species identification. Qualitative characteristics results indicated some similarities and differences that are taxonomically important for comparing taxonomical grouping with morphological data for the genetic description of Acacia species. The activities of antioxidant enzymes have been studied intensively and the results provide strong similarities between the Acacia species (69%), between A. raddiana (Siwa and Borg Al-Arab) and A. saligna, followed by all Acacia species (50%). Finally, the molecular studies showed that a total of 563 amplification fragments, 190 fragments were monomorphic, and 373 fragments were polymorphic. The highest number of amplification fragments (21) was detected with OPB-20 primer, while OPA-20 showed seven amplification fragments; the average number was 13.09. The results indicated that Acacia species exhibit high genetic differentiation, helpful in the future for genetic improvement programs. The novelty of the current study is highlighting the importance of plant genetic resources in Egypt and using different techniques to measure the differentiation between these species.
Development of an In Vitro Propagation Protocol and a Sequence Characterized Amplified Region (SCAR) Marker of Viola serpens Wall. ex Ging
Authors: Jha Shipra Rani , Naz Ruphi , Asif Ambreen , Okla Mohammad K. , Soufan Walid , Al-Ghamdi Abdullah A. , Ahmad Altaf
Published: February 2020

An efficient protocol of plant regeneration through indirect organogenesis in Viola serpens was developed in the present study. Culture of leaf explants on MS (Murashige and Skoog) medium supplemented with 2.0 mg/L 6-benzyladenine and 0.13 mg/L 2,4-dichloro phenoxy acetic acid. Adventitious shoot formation was observed when calli were transferred on to MS medium containing 0.5 mg/L α-naphthalene acetic acid and 2.25 mg/L kinetin, which showed the maximum 86% shoot regeneration frequency. The highest root frequency (80.92%) with the 5.6 roots per explant and 1.87 cm root length was observed on MS medium supplemented with 2 mg/L indole-3-butyric acid. The plantlets were transferred to the mixture of sand, coffee husk and soil in the ratio of 1:2:1 in a pot, and placed under 80% shade net for one month. It was then transferred to 30% shade net for another one month, prior to transplantation in the field. These plantlets successfully acclimatized under field conditions. A Sequence Characterized Amplified Region (SCAR) marker was also developed using a 1135 bp amplicon that was obtained from RAPD (Random Amplification of Polymorphic DNA) analysis of six accessions of V. serpens. Testing of several market samples of V. serpens using the SCAR marker revealed successful identification of the genuine samples of V. serpens. This study, therefore, provides a proficient in vitro propagation protocol of V. serpens using leaf explants and a SCAR marker for the authentic identification of V. serpens. This study will be helpful for conservation of authentic V. serpens.
DNA N6-Methyladenine Modification in Plant Genomes—A Glimpse into Emerging Epigenetic Code
Authors: Karanthamalai Jeyalakshmi , Chodon Aparna , Chauhan Shailja , Pandi Gopal
Published: February 2020

N6-methyladenine (6mA) is a DNA base modification at the 6th nitrogen position; recently, it has been resurfaced as a potential reversible epigenetic mark in eukaryotes. Despite its existence, 6mA was considered to be absent due to its undetectable level. However, with the new advancements in methods, considerable 6mA distribution is identified across the plant genome. Unlike 5-methylcytosine (5mC) in the gene promoter, 6mA does not have a definitive role in repression but is exposed to have divergent regulation in gene expression. Though 6mA information is less known, the available evidences suggest its function in plant development, tissue differentiation, and regulations in gene expression. The current review article emphasizes the research advances in DNA 6mA modifications, identification, available databases, analysis tools and its significance in plant development, cellular functions and future perspectives of research.
A Molecular Phylogenetic Study of the Genus Phedimus for Tracing the Origin of “Tottori Fujita” Cultivars
Authors: Han Sung Kyung , Kim Tae Hoon , Kim Jung Sung
Published: February 2020

It is very important to confirm and understand the genetic background of cultivated plants used in multiple applications. The genetic background is the history of crossing between maternal and paternal plants to generate a cultivated plant. If the plant in question was generated from a simple origin and not complicated crossing, we can easily confirm the history using a phylogenetic tree based on molecular data. This study was conducted to trace the origin of “Tottori Fujita 1gou” and “Tottori Fujita 2gou”, which are registered as cultivars originating from Phedimus kamtschaticus. To investigate the phylogenetic position of these cultivars, the backbone tree of the genus Phedimus needed to be further constructed because it retains inarticulate phylogenetic relationships among the wild species. We performed molecular phylogenetic analysis for P. kamtschaticus, Phedimus takesimensis, Phedimus aizoon, and Phedimus middendorffianus, which are assumed as the species of origin for “Tottori Fujita 1gou” and “Tottori Fujita 2gou”. The molecular phylogenetic tree based on the internal transcribed spacer (ITS) and psbA-trnH sequences showed the monophyly of the genus Phedimus, with P. takesimensis forming a single clade. However, P. kamtschaticus and P. aizoon were scattered in the tree. It was verified that “Tottori Fujita 1gou” and “Tottori Fujita 2gou” were embedded in a clade with P. takesimensis and not P. kamtschaticus. Therefore, origination from P. takesimensis was strongly supported. Based on these results, molecular phylogenetic analysis is suggested as a powerful tool for clearly tracing the origin of cultivated plants.
Co-Suppression of NbClpC1 and NbClpC2, Encoding Clp Protease Chaperons, Elicits Significant Changes in the Metabolic Profile of Nicotiana benthamiana
Authors: Ali Md. Sarafat , Baek Kwang-Hyun
Published: February 2020

Metabolites in plants are the products of cellular metabolic processes, and their differential amount can be regarded as the final responses of plants to genetic, epigenetic, or environmental stresses. The Clp protease complex, composed of the chaperonic parts and degradation proteases, is the major degradation system for proteins in plastids. ClpC1 and ClpC2 are the two chaperonic proteins for the Clp protease complex and share more than 90% nucleotide and amino acid sequence similarities. In this study, we employed virus-induced gene silencing to simultaneously suppress the expression of ClpC1 and ClpC2 in Nicotiana benthamiana (NbClpC1/C2). The co-suppression of NbClpC1/C2 in N. benthamiana resulted in aberrant development, with severely chlorotic leaves and stunted growth. A comparison of the control and NbClpC1/C2 co-suppressed N. benthamiana metabolomes revealed a total of 152 metabolites identified by capillary electrophoresis time-of-flight mass spectrometry. The co-suppression of NbClpC1/C2 significantly altered the levels of metabolites in glycolysis, the tricarboxylic acid cycle, the pentose phosphate pathway, and the purine biosynthetic pathway, as well as polyamine and antioxidant metabolites. Our results show that the simultaneous suppression of ClpC1 and ClpC2 leads to aberrant morphological changes in chloroplasts and that these changes are related to changes in the contents of major metabolites acting in cellular metabolism and biosynthetic pathways.
Plant Growth Inhibitory Activities and Volatile Active Compounds of 53 Spices and Herbs
Authors: Sekine Takayuki , Appiah Kwame Sarpong , Azizi Majid , Fujii Yoshiharu
Published: February 2020

The inhibitory activities of the leachates and volatiles from 53 plant species (spices and herbs) were evaluated against lettuce (Lactuca sativa “Great Lakes 366”) seedling growth using the sandwich and dish pack methods, respectively. With the sandwich method, parsley (Petroselinum sativum) showed the strongest inhibitory effect on lettuce radicle growth (77%), followed by tarragon (Artemisia dracunculus) (72%). However, caraway (Carum carvi), dill (Anethum graveolens) (seed), laurel (Laurus nobilis), rosemary (Rosmarinus officinalis), and sage (Salvia officinalis) were the most inhibitory species (100% inhibition of lettuce radicle and hypocotyl growth inhibition at all distance wells) in the dish pack method. Cardamom (Elettaria cardamomum) and thyme (Thymus vulgaris) also showed strong inhibitory activity (100% for radicle and hypocotyl growth inhibition at all 41 and 58 mm distance wells). The headspace sampling and gas chromatography-mass spectrometry (GC-MS) analysis identified the main inhibitory active compounds as carvone in caraway and dill (seeds), 1,8-cineole in laurel and cardamom, and borneol in thyme. Both camphor and 1,8-cineole were detected in rosemary and sage, and the total activity evaluation showed that camphor was the major inhibitory compound in rosemary, although both compounds played equal roles in sage.
Water Deficit Affects the Growth and Leaf Metabolite Composition of Young Loquat Plants
Authors: Gugliuzza Giovanni , Talluto Giuseppe , Martinelli Federico , Farina Vittorio , Lo Bianco Riccardo
Published: February 2020

Water scarcity in the Mediterranean area is very common and understanding responses to drought is important for loquat management and production. The objective of this study was to evaluate the effect of drought on the growth and metabolism of loquat. Ninety two-year-old plants of ‘Marchetto’ loquat grafted on quince were grown in the greenhouse in 12-liter pots and three irrigation regimes were imposed starting on 11 May and lasting until 27 July, 2013. One-third of the plants was irrigated with 100% of the water consumed (well watered, WW), a second group of plants was irrigated with 66% of the water supplied to the WW plants (mild drought, MD), and a third group was irrigated with 33% of the water supplied to the WW plants (severe drought, SD). Minimum water potential levels of −2.0 MPa were recorded in SD plants at the end of May. Photosynthetic rates were reduced according to water supply (WW > MD > SD), especially during the morning hours. By the end of the trial, severe drought reduced all growth parameters and particularly leaf growth. Drought induced early accumulation of sorbitol in leaves, whereas other carbohydrates were not affected. Of over 100 leaf metabolites investigated, 9 (squalene, pelargonic acid, glucose-1-phosphate, palatinol, capric acid, aconitic acid, xylitol, lauric acid, and alanine) were found to be useful to discriminate between the three irrigation groups, suggesting their involvement in loquat metabolism under drought conditions. Loquat behaved as a moderately drought-tolerant species (limited stem water potential and growth reductions) and the accumulation of sorbitol in favor of sucrose in mildly-stressed plants may be considered an early protective mechanism against leaf dehydration and a potential biochemical marker for precise irrigation management.
Efficient Removal of Pb(II) from Aqueous Solutions by Using Oil Palm Bio-Waste/MWCNTs Reinforced PVA Hydrogel Composites: Kinetic, Isotherm and Thermodynamic Modeling
Authors: Zulfiqar Muhammad , Lee San Yi , Mafize Amira Azreena , Kahar Nur Adlin Mastura Abdul , Johari Khairiraihanna , Rabat Nurul Ekmi
Published: February 2020

Polyvinyl alcohol (PVA) hydrogel are still restricted for some applications because their lower mechanical strength and thermal stability. The PVA-based composites are drawing attention for the removal of heavy metals based on their specific functionality in adsorption process. The main objective of this work is to synthesize oil palm bio-waste (OPB)/multiwalled carbon nanotubes (MWCNTs) reinforced PVA hydrogels in the presence of N,N′-methylenebisacrylamide (NMBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator via simple in-situ polymerization technique. The as-prepared reinforced nanocomposites were characterized by FESEM, BET surface area, differential scanning calorimetry (DSC), TGA and FTIR analysis. The possible influence of OPB and MWCNTs on the tensile strength, elongation at break and elastic modulus of the samples were investigated. It was found that reinforced nanocomposites exhibited enhanced mechanical properties as compared to non-reinforced material. The evaluation of reinforced nanocomposites was tested by the removal of Pb(II) aqueous solutions in a batch adsorption system. The pseudo-second-order kinetic model was used to illustrate the adsorption kinetic results and Langmuir isotherm was more suitable to fit the equilibrium results providing maximum adsorption capacities. The evaluation of thermodynamic parameters describes the spontaneous, endothermic and chemisorption adsorption process while activation energy reveals the physical adsorption mechanism. Therefore, the coordination effects among OPB, MWCNTs and PVA polymer hydrogels can produce a promising adsorbent material for wastewater treatment applications.
Effect of Toughening with Different Liquid Rubber on Dielectric Relaxation Properties of Epoxy Resin
Authors: Wang Chuang , Sun Qing , Lei Kang , Chen Chi , Yao Lixiao , Peng Zongren
Published: February 2020

Liquid rubber is a common filler introduced to epoxy resin to improve its toughness for electrical insulation and electronic packaging applications. The improvement of toughness by adding liquid rubber to epoxy resin leads to the variation of its dielectric properties and relaxation behaviors and it has not been systematically studied yet. In this paper, four kinds of liquid rubber with different polarity were selected and the corresponding epoxy/liquid rubber composites have been prepared. By analyzing the temperature and frequency dependence of dielectric spectra, we found that a lower relative dielectric constant and dielectric loss of the epoxy/liquid rubber composites could be achieved by reducing the polarity of liquid rubber filler. These results also confirm that the polarity of liquid rubber plays a critical role in determining the α transition relaxation strength of rubber molecules at about −50 °C, as well as the relaxation time of interfacial polarization. In addition, the conductivity of rubber phase with different polarity were investigated by studying the apparent activation energy of interfacial polarization calculated from the Arrhenius plot. This study can provide a theoretical basis for designing high-performance epoxy/liquid rubber composite insulating materials for industrial use.
Effect of Natural Rubber in Polyethylene Composites on Morphology, Mechanical Properties and Biodegradability
Authors: Mastalygina Elena , Varyan Ivetta , Kolesnikova Natalya , Gonzalez Maria Isabel Cabrera , Popov Anatoly
Published: February 2020

Compounding natural additives with synthetic polymers allows developing more eco-friendly materials with enhanced biodegradability. The composite films based on low-density polyethylene (PE) with different content of natural rubber (NR) (10–30 wt%) were investigated. The influence of NR content on structural features, water absorption and mechanical properties of the composites were studied. The 70PE/30NR composite is characterized by the uniform distribution and the smallest size of NR domains (45 ± 5 μm). A tensile test was satisfied by the mechanical properties of the biocomposites, caused by elasticity of NR domains. The tensile strength of 70PE/30NR composite film is 5 ± 0.25 MPa. Higher water absorption of PE/NR composites (1.5–3.7 wt%) compared to neat PE facilitates penetrating vital activity products of microorganisms. Mycological test with mold fungi and full-scale soil test detected the composite with 30 wt% of NR as the most biodegradable (mass loss was 7.2 wt% for 90 days). According to infrared spectroscopy and differential scanning calorimetry analysis, NR consumption and PE structural changes in the biocomposites after exposure to soil occurred. The PE/NR composites with enhanced biodegradability as well as satisfied mechanical and technological properties have potential applications in packaging and agricultural films.
A One-Pot Synthesis and Characterization of Antibacterial Silver Nanoparticle–Cellulose Film
Authors: Chen Qi-Yuan , Xiao Sheng-Ling , Shi Sheldon Q. , Cai Li-Ping
Published: February 2020

Using N,N-dimethylacetamide (DMAc) as a reducing agent in the presence of PVP-K30, the stable silver nanoparticles (Ag-NPs) solution was prepared by a convenient method for the in situ reduction of silver nitrate. The cellulose–Ag-NPs composite film (CANF) was cast in the same container using lithium chloride (LiCl) giving the Ag-NPs-PVP/DMAc solution cellulose solubility as well as γ-mercaptopropyltrimethoxysilane (MPTS) to couple Ag-NPs and cellulose. The results showed that the Ag-NPs were uniformly dispersed in solution, and the solution had strong antibacterial activities. It was found that the one-pot synthesis allowed the growth of and cross-linking with cellulose processes of Ag-NPs conducted simultaneously. Approximately 61% of Ag-NPs was successfully loaded in CANF, and Ag-NPs were uniformly dispersed in the surface and internal of the composite film. The composite film exhibited good tensile properties (tensile strength could reach up to 86.4 MPa), transparency (light transmittance exceeds 70%), thermal stability, and remarkable antibacterial activities. The sterilization effect of CANF0.04 against Staphylococcus aureus and Escherichia coli exceed 99.9%. Due to low residual LiCl/DMAc and low diffusion of Ag-NPs, the composite film may have potential for applications in food packaging and bacterial barrier.
Fracture Toughness Analysis of Epoxy-Recycled Rubber-Based Composite Reinforced with Graphene Nanoplatelets for Structural Applications in Automotive and Aeronautics
Authors: Irez Alaeddin Burak , Bayraktar Emin , Miskioglu Ibrahim
Published: February 2020

This study proposes a new design of lightweight and cost-efficient composite materials for the aeronautic industry utilizing recycled fresh scrap rubber, epoxy resin, and graphene nanoplatelets (GnPs). After manufacturing the composites, their bending strength and fracture characteristics were investigated by three-point bending (3PB) tests. Halpin–Tsai homogenization adapted to composites containing GnPs was used to estimate the moduli of the composites, and satisfactory agreement with the 3PB test results was observed. In addition, 3PB tests were simulated by finite element method incorporating the Halpin–Tsai homogenization, and the resulting stress–strain curves were compared with the experimental results. Mechanical test results showed that the reinforcement with GnPs generally increased the modulus of elasticity as well as the fracture toughness of these novel composites. Toughening mechanisms were evaluated by SEM fractography. The typical toughening mechanisms observed were crack deflection and cavity formation. Considering the advantageous effects of GnPs on these novel composites and cost efficiency gained by the use of recycled rubber, these composites have the potential to be used to manufacture various components in the automotive and aeronautic industries as well as smart building materials in civil engineering applications.
Thermodynamic Properties and State Diagram of Gum Ghatti-Based Edible Films: Effects of Glycerol and Nisin
Authors: Zhang Pingping , Zhao Ya , Zhang Xin , Zhu Lanlan , Fang Zhongxiang , Shi Qilong
Published: February 2020

In this present study, the thermodynamic and thermal properties of glycerol and nisin-incorporated gum ghatti (GG, Anogeissus latifolia)-based films were determined. The films exhibited type III isotherm behaviors. Moisture content (MC) of films was increased with increasing water activity (aw) and decreased with higher temperature. The incorporation of glycerol and nisin increased the sorption ability of GG films. The net isosteric heat of adsorption (qst) and differential entropy (Sd) were decreased with increasing MC, showing an exponential negative correlation between them. Spreading pressure (φ) was increased with increasing aw, but decreased with higher temperature. This incorporation of glycerol and nisin increased the qst, Sd and φ of the GG films. The sorption behaviors were enthalpy-driven and non-spontaneous processes. The glass transition temperature (Tg), critical MC and aw of the films were decreased, and increased respectively with the incorporation of glycerol and nisin. This work provides a theoretical basis for the application of edible films in fresh food preservation.
ECM Mimetic Electrospun Porous Poly (L-lactic acid) (PLLA) Scaffolds as Potential Substrates for Cardiac Tissue Engineering
Authors: Muniyandi Priyadharshni , Palaninathan Vivekanandan , Veeranarayanan Srivani , Ukai Tomofumi , Maekawa Toru , Hanajiri Tatsuro , Mohamed Mohamed Sheikh
Published: February 2020

Cardiac tissue engineering (CTE) aims to generate potential scaffolds to mimic extracellular matrix (ECM) for recreating the injured myocardium. Highly porous scaffolds with properties that aid cell adhesion, migration and proliferation are critical in CTE. In this study, electrospun porous poly (l-lactic acid) (PLLA) porous scaffolds were fabricated and modified with different ECM derived proteins such as collagen, gelatin, fibronectin and poly-L-lysine. Subsequently, adult human cardiac fibroblasts (AHCF) were cultured on the protein modified and unmodified fibers to study the cell behavior and guidance. Further, the cytotoxicity and reactive oxygen species (ROS) assessments of the respective fibers were performed to determine their biocompatibility. Excellent cell adhesion and proliferation of the cardiac fibroblasts was observed on the PLLA porous fibers regardless of the surface modifications. The metabolic rate of cells was on par with the conventional cell culture ware while the proliferation rate surpassed the latter by nearly two-folds. Proteome profiling revealed that apart from being an anchorage platform for cells, the surface topography has modulated significant expression of the cellular proteome with many crucial proteins responsible for cardiac fibroblast growth and proliferation.
Qualification of New Methods for Measuring In Situ Rheology of Non-Newtonian Fluids in Porous Media
Authors: Jacobsen Jørgen Gausdal , Shiran Behruz Shaker , Skauge Tormod , Sorbie Kenneth Stuart , Skauge Arne
Published: February 2020

Pressure drop (ΔP) versus volumetric injection rate (Q) data from linear core floods have typically been used to measure in situ rheology of non-Newtonian fluids in porous media. However, linear flow is characterized by steady-state conditions, in contrast to radial flow where both pressure and shear-forces have non-linear gradients. In this paper, we qualify recently developed methods for measuring in situ rheology in radial flow experiments, and then quantitatively investigate the robustness of these methods against pressure measurement error. Application of the new methods to experimental data also enabled accurate investigation of memory and rate effects during polymer flow through porous media. A radial polymer flow experiment using partially hydrolyzed polyacrylamide (HPAM) was performed on a Bentheimer sandstone disc where pressure ports distributed between a central injector and the perimeter production line enabled a detailed analysis of pressure variation with radial distance. It has been suggested that the observed shear-thinning behavior of HPAM solutions at low flux in porous media could be an experimental artifact due to the use of insufficiently accurate pressure transducers. Consequently, a generic simulation study was conducted where the level of pressure measurement error on in situ polymer rheology was quantitatively investigated. Results clearly demonstrate the robustness of the history match methods to pressure measurement error typical for radial flow experiments, where negligible deviations from the reference rheology was observed. It was not until the error level was increased to five-fold of typical conditions that significant deviation from the reference rheology emerged. Based on results from pore network modelling, Chauveteau (1981) demonstrated that polymer flow in porous media may at some rate be influenced by the prior history. In this paper, polymer memory effects could be evaluated at the Darcy scale by history matching the pressure drop between individual pressure ports and the producer as a function of injection rate (conventional method). Since the number of successive contraction events increases with radial distance, the polymer has a different pre-history at the various pressure ports. Rheology curves obtained from history matching the radial flow experiment were overlapping, which shows that there is no influence of geometry on in-situ rheology for the particular HPAM polymer investigated. In addition, the onset of shear-thickening was independent of volumetric injection rate in radial flow.
Performance Optimization of Polymer Fibre Actuators for Soft Robotics
Authors: Rukhlenko Ivan D. , Farajikhah Syamak , Lilley Charles , Georgis Andre , Large Maryanne , Fleming Simon
Published: February 2020

Analytical modeling of soft pneumatic actuators constitutes a powerful tool for the systematic design and characterization of these key components of soft robotics. Here, we maximize the quasi-static bending angle of a soft pneumatic actuator by optimizing its cross-section for a fixed positive pressure inside it. We begin by formulating a general theoretical framework for the analytical calculation of the bending angle of pneumatic actuators with arbitrary cross-sections, which is then applied to an actuator made of a circular polymer tube and an asymmetric patch in the shape of a hollow-cylinder sector on its outer surface. It is shown that the maximal bending angle of this actuator can be achieved using a wide range of patches with different optimal dimensions and approximately the same cross-sectional area, which decreases with pressure. We also calculate the optimal dimensions of thin and small patches in thin pneumatic actuators. Our analytical results lead to clear design guidelines, which may prove useful for engineering and optimization of the key components of soft robotics with superior features.
Melt-Electrospun Polyethylene Nanofiber Obtained from Polyethylene/Polyvinyl Butyral Blend Film
Authors: Zakaria Mohammad , Shibahara Kanta , Nakane Koji
Published: February 2020

We prepared low-density polyethylene (LDPE) nanofiber, a few hundred nanometers in diameter, using polyvinyl butyral (PVB) and a laser melt-electrospinning (M-ESP) device. We blended PVB with LDPE via an internal melt mixer, removed the PVB after M-ESP by ethanol treatment, and studied the influence of PVB on fiber diameter. A substantial diameter reduction with improved crystallinity of LDPE fiber was observed with increased PVB content in the blend. PVB inclusion also increased the polarity of the LDPE/PVB blend, resulting in better spinnability. The removal of PVB from LDPE/PVB blend fiber caused a massive drop in the LDPE fiber diameter, due to fiber splitting, particularly in PVB-rich samples. Fourier transform infrared (FTIR) spectroscopy of fibers confirmed that the prepared nanofiber was the same as pure LDPE fiber.
Accelerated Weathering and Soil Burial Effect on Biodegradability, Colour and Textureof Coir/Pineapple Leaf Fibres/PLA Biocomposites
Authors: Siakeng Ramengmawii , Jawaid Mohammad , Asim Mohammad , Siengchin Suchart
Published: February 2020

Accelerated weathering and soil burial tests on biocomposites of various ratios of coir (CF)/pineapple leaf fibres (PALF) with polylactic acid (PLA) were conducted to study the biodegradability, colour, and texture properties as compared with PLA.The biodegradability of a lignocellulosic composite largely depends on its polymer matrix, and the rate of biodegradation depends on many environmental factors such as moisture, light(radiation), temperature and microbes. Biodegradation was evaluated by soil burial and accelerated weathering tests. Changes in physical and morphological properties were observed in the biocomposites after weathering. These results allowed us to conclude that untreated CF/PALF/PLA biocomposites would be a more favourable choice owing to their better biodegradability and are suitable for the suggested biodegradable food packaging applications.
Fabrication of Porous Recycled HDPE Biocomposites Foam: Effect of Rice Husk Filler Contents and Surface Treatments on the Mechanical Properties
Authors: Abdul Azam Farah Atiqah , Rajendran Royan Nishata Royan , Yuhana Nor Yuliana , Mohd Radzuan Nabilah Afiqah , Ahmad Sahrim , Sulong Abu Bakar
Published: February 2020

In this study, a biodegradable, cheap and durable recycled high-density polyethylene (rHDPE) polymer reinforced with rice husk (RH) fibre was fabricated into a foam structure through several processes, including extrusion, internal mixing and hot pressing. The effect of filler loading on the properties of the foam and the influence of RH surface treatments on the filler–matrix adhesion and mechanical properties of the composite foam were investigated. The morphological examination shows that 50 wt.% filler content resulted in an effective dispersion of cells with the smallest cell size (58.3 µm) and the highest density (7.62 × 1011 sel/cm3). This small cell size benefits the mechanical properties. Results indicate that the tensile strength and the Young’s modulus of the alkali-treated RH/rHDPE composite foam are the highest amongst the treatments (10.83 MPa and 858 MPa, respectively), followed by UV/O3, which has shown considerable increments compared with the untreated composite. The flexural and impact tests also show the increment in strength for the composite foam after chemical treatment. Although the UV/O3 surface treatment has minor influence on the mechanical enhancement of the composite foam, this method may be a reliable surface treatment of the fibre-reinforced composite.
Multi-Trigger Thermo-Electro-Mechanical Soft Actuators under Large Deformations
Authors: Yarali Ebrahim , Noroozi Reza , Yousefi Armin , Bodaghi Mahdi , Baghani Mostafa
Published: February 2020

Dielectric actuators (DEAs), because of their exceptional properties, are well-suited for soft actuators (or robotics) applications. This article studies a multi-stimuli thermo-dielectric-based soft actuator under large bending conditions. In order to determine the stress components and induced moment (or stretches), a nominal Helmholtz free energy density function with two types of hyperelastic models are employed. Non-linear electro-elasticity theory is adopted to derive the governing equations of the actuator. Total deformation gradient tensor is multiplicatively decomposed into electro-mechanical and thermal parts. The problem is solved using the second-order Runge-Kutta method. Then, the numerical results under thermo-mechanical loadings are validated against the finite element method (FEM) outcomes by developing a user-defined subroutine, UHYPER in a commercial FEM software. The effect of electric field and thermal stimulus are investigated on the mean radius of curvature and stresses distribution of the actuator. Results reveal that in the presence of electric field, the required moment to actuate the actuator is smaller. Finally, due to simplicity and accuracy of the present boundary problem, the proposed thermally-electrically actuator is expected to be used in future studies and 4D printing of artificial thermo-dielectric-based beam muscles.
Ionic Liquid as Dispersing Agent of LDH-Carbon Nanotubes into a Biodegradable Vinyl Alcohol Polymer
Authors: Bugatti Valeria , Viscusi Gianluca , Di Bartolomeo Antonio , Iemmo Laura , Zampino Daniela Clotilde , Vittoria Vittoria , Gorrasi Giuliana
Published: February 2020

A Zn/Al layered double hydroxides (LDHs) hosting carbon nanotubes (80% of CNTs) was synthesized and dispersed into a commercial biodegradable highly amorphous vinyl alcohol polymer at different loading (i.e., 1; 3; 5; 10 wt %). In order to improve the degree of dispersion of the filler into the polymer matrix, an ionic liquid (IL) based on 1-hexadecyl-3-methylimidazolium dimethyl-5-sodiosulfoisophthalate was added to the composites’ mixtures. Structural characterization of filler and polymeric composites was carried out. The analysis of thermal, mechanical and electrical properties of the composites, resulted improved compared to the unfilled material, allowed to hypothesize a good dispersion of the LDH-CNTs lamellar filler into the polymer matrix-assisted by the ionic liquid. This was demonstrated comparing electrical conductivity of composite at 5% of LDH-CNTs in the presence and in the absence of IL. The experimental results showed that the electrical conductivity of the sample with IL is four orders of magnitude higher than the one without IL. Furthermore, the percolation threshold of the whole system resulted very low—0.26% of LDH-CNTs loading, which is 0.21% of CNTs.
Oxidation–Responsive Emulsions Stabilized with Poly(Vinyl Pyrrolidone-co-allyl Phenyl Sulfide)
Authors: Park Seok Ho , Kim Jin-Chul
Published: February 2020

Oxidation-responsive emulsions were obtained by stabilizing mineral oil droplets using amphiphilic poly(vinyl pyrrolidone-co-allyl phenyl sulfide) (P(VP-APS)). 1H nuclear magnetic resonance (NMR) spectroscopy revealed that P(VP-APS) whose APS content was 0%, 3.28%, 3.43% and 4.58% were successfully prepared by free radical reaction and the sulfide of APS was oxidized by H2O2 treatment. X-ray Photoelectron Spectroscopy (XPS) also disclosed that the sulfide of APS was oxidized to sulfone by the oxidizing agent. The optical density of copolymer solutions and the interfacial activity of the copolymers markedly decreased by H2O2 treatment possibly because the sulfide of APS was oxidized and the amphiphilicity of the copolymers were weakened. The increase rate of the oil droplet diameter of the emulsions was outstandingly promoted when H2O2 solution (10%, v/v) was used as an aqueous phase. The phase separation of the emulsions was also expedited by the oxidizing agent. The oxidation of APS and the weakened interfacial activity were thought to be a main reason for the demulsification of P(VP-APS)-stabilized emulsions.
Comparing Composition Control Structures for Kaibel Distillation Columns
Authors: Yuan Yang , Huang Kejin , Chen Haisheng , Qian Xing , Zang Lijing , Zhang Liang , Wang Shaofeng
Published: February 2020

Although Kaibel distillation columns are superior to conventional distillation sequences owing to smaller equipment investment and operation cost, they display high nonlinearity and this greatly increases the difficulty of achieving their tight control. To overcome this problem, four decentralized composition control structures, i.e., the CSR/QR, CSR/B, CSD/QR, and CSD/B structures, are proposed and compared based on the control of a Kaibel distillation column fractionating a methanol/ethanol/propanol/butanol quaternary mixture. These four composition control structures all include five composition control loops. While the four of them are employed to maintain the purity of the top, upper sidestream, lower sidestream, and bottom products, the remaining one is employed to minimize the energy consumption of the Kaibel distillation column by maintaining the composition of propanol at the first stage of the prefractionator. Dynamic simulation results show the CSR/QR and CSR/B structures can tightly maintain the purity of the controlled products with a small overshoot and short settling time after facing various disturbances in feed conditions, but the CSD/QR and CSD/B structures lead to oscillatory responses (the latter even shows divergent responses under individual disturbances). At the end of the article, some effective guides for developing composition control systems are given.
Controlled Hydrodynamic Cavitation: A Review of Recent Advances and Perspectives for Greener Processing
Authors: Panda Debabrata , Saharan Virendra Kumar , Manickam Sivakumar
Published: February 2020

The 20th century has witnessed a remarkable enhancement in the demand for varieties of consumer products, ranging from food, pharmaceutical, cosmetics, to other industries. To enhance the quality of the product and to reduce the production cost, industries are gradually inclined towards greener processing technologies. Cavitation-based technologies are gaining interest among processing technologies due to their cost effectiveness in operation, minimization of toxic solvent usage, and ability to obtain superior processed products compared to conventional methods. Also, following the recent advancements, cavitation technology with large-scale processing applicability is only denoted to the hydrodynamic cavitation (HC)-based method. This review includes a general overview of hydrodynamic cavitation-based processing technologies and a detailed discussion regarding the process effectiveness. HC has demonstrated its usefulness in food processing, extraction of valuable products, biofuel synthesis, emulsification, and waste remediation, including broad-spectrum contaminants such as pharmaceuticals, bacteria, dyes, and organic pollutants of concern. Following the requirement of a specific process, HC has been implemented either alone or in combination with other process-intensifying steps, for example, catalyst, surfactant, ultraviolet (UV), hydrogen peroxide (H2O2), and ozone (O3), for better performance. The reactor set-up of HC includes orifice, slit venturi, rotor-stator, and sonolator type constrictions that initiate and control the formation of bubbles. Moreover, the future directions have also been pointed out with careful consideration of specific drawbacks.
Optimization of a Confined Jet Geometry to Improve Film Cooling Performance Using Response Surface Methodology (RSM)
Authors: Al-Hemyari Mohammed , Hamdan Mohammad O. , Orhan Mehmet F.
Published: February 2020

This study investigates the interrelated parameters affecting heat transfer from a hot gas flowing on a flat plate while cool air is injected adjacent to the flat plate. The cool air forms an air blanket that shield the flat plate from the hot gas flow. The cool air is blown from a confined jet and is simulated using a two-dimensional numerical model under three variable parameters; namely, blowing ratio, jet angle and density ratio. The interrelations between these parameters are evaluated to properly understand their effects on heat transfer. The analyses are conducted using ANSYS-Fluent, and the performance of the air blanket is reported using local and average adiabatic film cooling effectiveness (AFCE). The interrelation between these parameters and the AFCE is established through a statistical method known as response surface methodology (RSM). The RSM model shows that the AFCE has a second order relation with the blowing ratio and a first order relation with both jet angle and density ratio. Also, it is found that the highest average AFCE is reached at an injection angle of 30 degree, a density ratio of 1.2 and a blowing ratio of 1.8.
Multi-Scale Context Aggregation for Semantic Segmentation of Remote Sensing Images
Authors: Zhang Jing , Lin Shaofu , Ding Lei , Bruzzone Lorenzo
Published: February 2020

The semantic segmentation of remote sensing images (RSIs) is important in a variety of applications. Conventional encoder-decoder-based convolutional neural networks (CNNs) use cascade pooling operations to aggregate the semantic information, which results in a loss of localization accuracy and in the preservation of spatial details. To overcome these limitations, we introduce the use of the high-resolution network (HRNet) to produce high-resolution features without the decoding stage. Moreover, we enhance the low-to-high features extracted from different branches separately to strengthen the embedding of scale-related contextual information. The low-resolution features contain more semantic information and have a small spatial size; thus, they are utilized to model the long-term spatial correlations. The high-resolution branches are enhanced by introducing an adaptive spatial pooling (ASP) module to aggregate more local contexts. By combining these context aggregation designs across different levels, the resulting architecture is capable of exploiting spatial context at both global and local levels. The experimental results obtained on two RSI datasets show that our approach significantly improves the accuracy with respect to the commonly used CNNs and achieves state-of-the-art performance.
RETRACTED: Zhu et al. Attention-Based Deep Feature Fusion for the Scene Classification of High-Resolution Remote Sensing Images. Remote Sens. 2019, 11, 1996
Authors: Zhu Ruixi , Yan Li , Mo Nan , Liu Yi
Published: February 2020

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