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This paper aims at improving the mechanical behavior of biobased brittle amorphous polylactide (PLA) by extrusion melt-blending with biobased semi-crystalline polyamide 11 (PA11) and addition of halloysite nanotubes (HNT). The morphological analysis of the PLA/PA11/HNT blends shows a strong interface between the two polymeric phases due to hydrogen bonding, and the migration of HNTs towards PA11 phase inducing their selective localization in one of the polymeric phases of the blend. A ‘salami-like’ structure is formed revealing a HNTs-rich tubular-like (fibrillar) PA11 phase. Moreover, HNTs localized in the dispersed phase act as nucleating agents for PA11. Compared to neat PLA, this leads to a remarkable improvement in tensile and impact properties (elongation at break is multiplied by a factor 43, impact strength by 2, whereas tensile strength and stiffness are almost unchanged). The toughening mechanism is discussed based on the combined effect of resistance to crack propagation and nanotubes load bearing capacity due to the existence of the fibrillar structure. Thus, blending brittle PLA with PA11 and HNT nanotubes results in tailor-made PLA-based compounds with enhanced ductility without sacrificing stiffness and strength.

Partly bio-based segmented thermoplastic polyurethane (TPU) formulations were developed to fulfill the requirements of the reactive rotational molding process. They were obtained by one-shot bulk polymerization between an aliphatic diisocyanate (1,6-hexamethylene diisocyanate), a polyether polyol as macrodiol (polyethylene glycol) and a biobased corn-derived 1,3-propanediol as chain extender (CE), in presence of a catalyst, at an initial temperature of 45°C. Equivalent TPU formulations with classical petroleum-based 1,3-propanediol were also prepared for a purpose of comparison. TPU with different soft to hard segment (SS/HS) ratios were synthesized by varying the macrodiol and CE concentrations in the formulations. For each formulation, the evolution of the reaction temperature as a function of time was monitored and the kinetics of polymerization was studied by Fourier Transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR). The morphology, thermal properties, solubility in different solvents and tensile properties of the final products were analyzed. All synthesized polyurethanes are 100% linear polymers and the extent of microphase separation, as well as the thermal and mechanical properties highly depends on the HS content, and glass transition temperature and Young modulus can be tuned by adjustment of the SS/HS ratio. All results indicate that petrochemical CE can be replaced by its recently available corn-derived homologue, without sacrificing any use properties of the final polyurethanes.

Background: We evaluated progressive changes in excitability of motor cortex following ischemic stroke using Transcranial Magnetic Stimulation (TMS). Materials and Methods: Thirty-one patients (24 men, 7 women; age 37.3 ± 8.2 years) were recruited and TMS was performed using Magstim 200 stimulator and a figure-of-eight coil. Resting motor threshold (RMT) was recorded from affected and unaffected hemispheres and motor evoked potential (MEP) was recorded from contralateral FDI muscle. Central motor conduction time (CMCT) was calculated using F wave method. All measurements were done at baseline (2 nd ), 4 th , and 6 th week of stroke. Results: Affected hemisphere: MEP was recordable in 3 patients at baseline (all had prolonged CMCT). At 4 weeks, MEP was recordable in one additional patient and CMCT remained prolonged. At 6 weeks, CMCT normalized in one patient. RMT was recordable (increased) in 3 patients at baseline, in one additional patient at 4 weeks, and reduced marginally in these patients at 6 weeks. Unaffected hemisphere: MEP was recordable in all patients at baseline, and reduced significantly over time (2 nd week 43.52 ± 9.60, 4 th week 38.84 ± 7.83, and 6 th week 36.85 ± 7.27; P < 0.001). The CMCT was normal and remained unchanged over time. Conclusion: The increase in excitability of the unaffected motor cortex suggests plasticity in the post-stroke phase.

Over several centuries, the energy consumption in the building increases with significant developing result in the growth of economic, population, temperature. Performances of energy in the building has been improved with reconstruction with efficient method based on the retrofitting of the building. Potential of energy saving has been consider at the same time with total energy in the account of the building. When it come to the improvement of energy in the historical building we have to treat in different way from normal building. The main aim of this study is based on the method that trans disciplinary to energy efficient in the historical building. To control the energy retrofit in the building a detail tool of simulation has been used. Based on the consumption of total energy, indoor temperature we can calibrate the simulation of energy in the building. The method that we used in this study helps to eliminate the value of cultural heritage. Then the consumption of energy effect will be validate with the gather packet of energy retrofits. Finally, the energy has been saved with any damage of the historical building. [ABSTRACT FROM AUTHOR]

The influence of polypropylene fibers on the thermal degradation of epoxy composites was investigated with thermogravimetric analysis. Three composites with 5, 10, or 15 wt % polypropylene fibers were prepared with epoxy as a matrix material. The polypropylene fibers, used as reinforcing materials, retarded the thermal decomposition, and increasing the weight percentage of the fiber material increased the thermal stability to a certain extent. Of the three composites, the 10 wt % polypropylene fiber/epoxy resin composite showed very good thermal stability, which was indicated by the increase in the resin decomposition temperature from 280°C for the 5 wt % polypropylene fiber/epoxy resin composite to 375°C for the 10 wt % polypropylene fiber/epoxy resin composite. The Horowitz–Metzger method was used to calculate the activation energies, and the results were tabulated. A morphological analysis was carried out with scanning electron microscopy to evaluate the dispersion of the fibers in the epoxy matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 500–503, 2007 [ABSTRACT FROM AUTHOR]

The development of triboelectric nanogenerators (TENGs) using sustainable materials addresses the global electronic waste issue. This research focuses on fabricating a TENG device with biodegradable polylactic acid (PLA) as the tribopositive material and polytetrafluoroethylene (PTFE) as the tribonegative material. ZnFe2O4 nanoparticles are incorporated into the PLA matrix to enhance surface charge density and synthesised via a simple combustion method. PLA-ZnFe2O4 composite films were prepared by solvent casting with varying nanofiller content (0.25, 0.45, 0.65, and 0.85 g). Prepared composites were characterised by Powder X-ray Diffraction (PXRD) for crystalline nature and phase purity, Fourier Transform Infrared Spectroscopy (FTIR) for vibrational analysis, and Scanning Electron Microscopy (SEM) for surface morphology. The inclusion of ZnFe2O4 nanoparticles improves TENG output performance, with a maximum output voltage of 18.4 V and a current of 1.57 µA observed for a PLA (poly(lactic acid)) composite with 39.39% nanoparticle content. Electrical studies on the optimised device show successful charging of various capacitors and powering 20 LEDs and a calculator. Body movements like walking and jumping were also tested to measure voltage and current outputs. These findings highlight new possibilities for developing smart, self-powered electronic devices. [ABSTRACT FROM AUTHOR]

In this work, a constitutive mechanical model is proposed to describe the thermo-mechanical cycle of a semi-crystalline shape memory polyurethane which is able to recover its initial shape after applying more than 100% strain during a shape memory cycle. To explore this performance, experimental tests were conducted to determine the cyclic thermo-mechanical behavior of a polymer submitted to five shape memory cycles. Indeed, uniaxial tensile tests at small strain rates were performed at 60 °C in order to analyze its hyper-elastic response. At the end of the previous tensile loading, relaxation tests were carried out to determine the viscoelastic behavior during the shape memory cycle. The shape memory effect was investigated by means of free and constrained recovery experiments. These experimental results are used to identify the parameters of the constitutive model by means of curve-fitting algorithm employing least-squares optimization approach. The proposed model is then implemented in the finite element software Comsol Multiphysics© and predicts quite well an in-plane strained cylindrical ring. [ABSTRACT FROM AUTHOR]

The current effort focuses on creating an effective adsorbent for Cr (VI) adsorption due to the growing need to address Cr (VI) pollution in aqueous solutions. Chitosan, a biopolymer and polysaccharide with several functional sites, is immobilized on alginate using the ion exchange technique. Both prior to and following Cr (VI) adsorption, the material's shape, crystallinity, and functional groups are reported. Immobilized chitosan was employed to adsorb Cr (VI) in a fixed bed column with variable operational parameters (flow rate, initial chromium content, and bed height). The analysis of breakthrough curves showed that at a flow rate of 10 mL/min, Cr (VI) concentration of 50 mg/L and a bed height of 18 cm, a maximum adsorption of 78.41 % was achieved. The adsorption system and the breakthrough curves were thoroughly understood by using Thomas, Yoon-Nelson and Adams-Bohart kinetic models. There is promise for the large-scale use of synthesized immobilized chitosan because the current adsorption process fits the Thomas and Yoon-Nelson model well and confirms the homogenous bed, low mass transfer resistance, and constant operating conditions throughout the experiment. Furthermore, an exploration of the adsorption mechanism is undertaken and the outcomes are compared with existing literature. The regeneration and reuse tests up to four cycles provided insight into the immobilized chitosan's stability, dependability, and potential for scaling up., Competing Interests: Declaration of competing interest Authors declare no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Poly(L-Lactide) (PLA), a fully biobased aliphatic polyester, has attracted significant attention in the last decade due to its exceptional set of properties, such as high tensile modulus/strength, biocompatibility, (bio)degradability in various media, easy recyclability and good melt-state processability by the conventional processes of the plastic/textile industry. Blending PLA with other polymers represents one of the most cost-effective and efficient approaches to develop a next-generation of PLA-based materials with superior properties. In particular, intensive research has been carried out on PLA-based blends with engineering polymers such as polycarbonate (PC), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT) and various polyamides (PA). This overview, consequently, aims to gather recent works over the last 10 years on these immiscible PLA-based blends processed by melt extrusion, such as twin screw compounding. Furthermore, for a better scientific understanding of various ultimate properties, processing by internal mixers has also been ventured. A specific emphasis on blend morphologies, compatibilization strategies and final (thermo)mechanical properties (tensile/impact strength, ductility and heat deflection temperature) for potential durable and high-performance applications, such as electronic parts (3C parts, electronic cases) to replace PC/ABS blends, has been made.

In the present work a novel pyrazole based chitosan Schiff base material was prepared using 5-azido-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and functionalized using Fe 3 O 4 -MoS 2 , where the nanoparticles get embedded within the gel matrix. The composite material was characterized using various techniques such as XRD, SEM, FTIR, EDS and TGA. The adsorbent material was analysed for the adsorptive take up process from the aqueous solutions of metal ion concentration ranging 20-100 mgL -1 . The maximum adsorption capacity obtained for the material was 200.00 and 125.00 mg/g for Cr(VI) and Cu(II) respectively. Adsorptive mechanism was found to have pseudo second order kinetics and the adsorption isotherm followed Langmuir adsorption model following the monolayer adsorptive process. Further the evaluated thermodynamic parameter showed the adsorption process to be spontaneous and endothermic in nature. Reusability of the composite material was achieved using suitable stripping solutions., Competing Interests: Declaration of competing interest The authors declare that for the research article titled ‘Efficient removal of metal ions from aqueous solutions using MoS(2) Functionalized Chitosan Schiff Base Incorporated with Fe(3)O(4) Nanoparticle’ have no competing financial interests or personal relationships with the research article., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Gastrointestinal tract (GIT) malignancies are an important public health problem considering the increased incidence in recent years and the high morbidity and mortality associated with it. GIT malignancies constitute 26% of the global cancer incidence burden and 35% of all cancer-related deaths. Gastrointestinal cancers are complex and heterogenous diseases caused by the interplay of genetic and environmental factors. The tumor microenvironment (TME) of gastrointestinal tract carcinomas is dynamic and complex; it cannot be recapitulated in the basic two-dimensional cell culture systems. In contrast, three-dimensional (3D) in vitro models can mimic the TME more closely, enabling an improved understanding of the microenvironmental cues involved in the various stages of cancer initiation, progression, and metastasis. However, the heterogeneity of the TME is incompletely reproduced in these 3D culture models, as they fail to regulate the orientation and interaction of various cell types in a complex architecture. To emulate the TME, 3D bioprinting has emerged as a useful technique to engineer cancer tissue models. Bioprinted cancer tissue models can potentially recapitulate cancer pathology and increase drug resistance in an organ-mimicking 3D environment. In this review, we describe the 3D bioprinting methods, bioinks, characterization of 3D bioprinted constructs, and their application in developing gastrointestinal tumor models that integrate their microenvironment with different cell types and substrates, as well as bioprinting modalities and their application in therapy and drug screening. We review prominent studies on the 3D bioprinted esophageal, hepatobiliary, and colorectal cancer models. In addition, this review provides a comprehensive understanding of the cancer microenvironment in printed tumor models, highlights current challenges with respect to their clinical translation, and summarizes future perspectives.

In this study, halloysite nanotubes (HNTs) were subjected to surface functionalization using sodium alginate and incorporated into poly(caprolactone) (PCL) to fabricate nanocomposites for potential wound healing applications. The nanocomposite films were fabricated through the solution casting technique and characterized using various instrumental methods. The films exhibited enhanced thermal and mechanical properties. FE-SEM and AFM analyses confirmed the uniform dispersion of the HNTs and increased roughness of the films, respectively. The swelling properties, in-vitro enzymatic degradation, and anti-inflammatory activity of the films were also analyzed. The MTT assay performed using NIH3T3 cell lines revealed enhanced cell proliferation (126 ± 1.38) of 5 wt% film. Besides, the cell adhesion tests of the films revealed their cytocompatibility. The scratch assay tests conducted for observing the effectiveness of the films for wound closure showed that the 5 wt% film offered a higher rate of fibroblast cell migration (32.24 ± 0.49) than the pristine PCL film. The HRBCMS assay demonstrated the hemocompatibility of these films. The biological test results indicated the delayed enzymatic degradability and haemocompatiblity of nanocomposites with enhanced cell adhesion, cell proliferation, and cell migration capabilities with respect to fibroblast cells. In summary, the synthesized nanocomposite films can be effectively used in wound healing applications after further clinical trials., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In the present work sodium alginate functionalized halloysite nanotubes (HNTs) reinforced poly (vinyl alcohol) nanocomposite films were prepared by solution casting technique. Sodium alginate surface functionalizing on the HNTs through hydrogen bonding was confirmed by spectroscopic and morphological analysis. The functionalized HNTs were successfully incorporated into the PVA matrix. Further, the films were characterized by using FTIR, TGA, XRD, SEM, AFM, UTM, WCA and swelling ratio analysis. The obtained results indicated improved physico-thermal properties, and uniform distribution of nanotubes in the matrix and roughness of the surface compared with the pristine PVA films. After inclusion of functionalized nanotubes causes enhancement of tensile strength as well as young's modulus of the nanocomposite films. Water contact angle measurement was carried out to know the hydrophilic or hydrophobic nature of the films and results were correlated with swelling ratio analysis. Furthermore, the films were analyzed for in-vitro biocompatibility studies. In -vitro enzymatic degradation was carried out in PBS media and cellular behaviour studies were analyzed using NIH3T3 cell lines. The results showed enhancement in the enzymatic degradation, proliferation, adhesion activity compared to that of pristine PVA films. In extension, nanocomposite films were subjected to hemocompatibility studies using human erythrocyte. The results revealed that nanocomposite films were biocompatible and hemocompatible. The fabricated films can be used in biomedical application., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The present study reports the preparation of novel surface functionalized halloysite nanotubes (HNTs) with chitosan incorporated Poly (vinyl alcohol) (PVA) nanocomposite films with desirable properties. Surface functionalization of HNTs with Chitosan through hydrogen bonding via acylation with succinic anhydride; supramolecular interaction was confirmed by spectroscopic and morphological analysis. The functionalized HNTs incorporated in the PVA matrix were subjected to FTIR studies, Atomic Force Microscopy, Scanning Electron Microscopy, X-ray diffraction, thermal, mechanical properties, Water Contact Angle, swelling ratio analysis and in-vitro biocompatibility studies. Results of the morphological studies showed that functionalized HNTs were uniformly dispersed and showed improved surface roughness with increasing weight percent of functionalized HNTs in the films. The studies revealed significant enhancement in the mechanical and thermal properties compared with the pristine PVA film. The hydrophilic or hydrophobic nature of films were analysed with WCA and results were compared with swelling studies. Furthermore, in vitro enzymatic degradation and cellular behaviour studies performed on mouse fibroblast (NIH3T3) cells and results confirmed enhanced proliferative and adhesion activity of nanocomposite films compared to that of pristine PVA films. In addition, hemocompatibility studies carried out using human erythrocytes revealed the biocompatible and hemocompatible of nanocomposite films indicating their greater potential for tissue engineering., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Among the 3D-printing technologies, fused deposition modeling (FDM) represents a promising route to enable direct incorporation of the battery within the final 3D object. Here, the preparation and characterization of lithium iron phosphate/polylactic acid (LFP/PLA) and SiO 2 /PLA 3D-printable filaments, specifically conceived respectively as positive electrode and separator in a lithium-ion battery is reported. By means of plasticizer addition, the active material loading within the positive electrode is raised as high as possible (up to 52 wt.%) while still providing enough flexibility to the filament to be printed. A thorough analysis is performed to determine the thermal, electrical and electrochemical effect of carbon black as conductive additive in the positive electrode and the electrolyte uptake impact of ceramic additives in the separator. Considering both optimized filaments composition and using our previously reported graphite/PLA filament for the negative electrode, assembled and "printed in one-shot" complete LFP/Graphite battery cells are 3D-printed and characterized. Taking advantage of the new design capabilities conferred by 3D-printing, separator patterns and infill density are discussed with a view to enhance the liquid electrolyte impregnation and avoid short-circuits.

The current study delineates the preparation of novel chitosan grafted silk fibre reinforced Poly (vinyl alcohol) (PVA) composite films with desirable properties. Although silk fibroin has been extensively used for various biomedical applications, its properties could be further re-tailored for its suitability in the field of regenerative medicine. Chitosan was successfully grafted over silk, via acylation with succinic anhydride and thereby the fibres were incised and used for the preparation of the films. The grafted silk fibre reinforced PVA films were subjected to FTIR studies, microscopic analysis by atomic force microscopy (AFM) and optical microscopy techniques, X-ray diffraction (XRD) analysis and further evaluated for in vitro biocompatibility studies. The composite films demonstrated improved surface roughness with increasing concentration of the fibre and its dispersion in the polymer matrix was observed. Furthermore, in vitro biocompatibility and cellular behaviour such as adhesion and proliferation of mouse fibroblasts as well as astrocyte cells was studied and the results showed improved proliferative activity, when compared to the pristine PVA films. These results were further supported by the results confirmed by MTT assay demonstrating the films to be non-toxic. The efficiency and feasibility of the films to be used for tissue engineering, was further evaluated by haemocompatibility studies using human erythrocytes, thus making them a potential material to be used for biomedical applications., (Copyright © 2018. Published by Elsevier B.V.)

Starch was combined with plasticizers such as glycerol, sorbitol, glycerol/sorbitol and urea/ethanolamine blends by means of high shear extrusion process to prepare thermoplastic starch (TPS). Effect of storage time and plasticizers on the structural stability of melt processed TPS was investigated. Morphological observation, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy reveal that melt extrusion process is efficient in transforming granular starch into a plasticized starch for all plasticizer compositions. XRD analysis highlights major changes in the microstructure of plasticized starch, and dependence of crystalline type and degree of crystallinity mainly on the plasticizer composition and storage time. Dynamical mechanical analysis (DMA) yields a decrease of the peak intensity of loss factor with aging time. The effect of ageing on tensile strength also appears to be highly dependent on the plasticizer composition. Thus, through different plasticizer combinations and ageing, starch-based materials with significant differences in tensile properties can be obtained, which may be tuned to meet the requirements of a wide range of applications., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Chronic injury to liver triggers synthesis of extracellular matrix components resulting in progressive fibrosis and eventually cirrhosis. Transforming growth factor-β1 (TGF-β1) transduces its signal by binding to TGF-β type 1 receptor kinase or activin like kinase (ALK5) receptor and mediates hepatic fibrosis by increasing the transcription of downstream entities such as collagen via Smad2 and Smad3. The present study was carried out to investigate the mechanism by which phyllanthin, a hepatoprotective lignin isolated from the plant Phyllanthus amarus (P. amarus) exerts its anti-fibrotic effect. The inhibitory role of phyllanthin on ALK5 was first analyzed using molecular docking experiments. Phyllanthin was found to effectively bind to serine (Ser) 280 at the active site of ALK5 by forming hydrogen bonds. The in vivo protective effect of phyllanthin against carbon tetrachloride (CCl4)-induced hepatic fibrosis was established by studying the protein expressions of TGF-β1, ALK5 and Smad2 and 3 and by determining various biochemical and histopathological parameters. Phyllanthin was found to exert its anti-fibrotic effect by down-regulating TGF signaling pathway via ALK5 and Smad2 and 3 inhibition.

Blends based on plasticized-wheat starch (as matrix or rich phase) and poly(ethylene oxide) (PEO) (as dispersed phase) were prepared by melt processing in a twin-screw extruder. The extrusion of the plasticized-starch is significantly facilitated by blending with PEO. Plasticized-starch and PEO are immiscible in the range of the investigated blend ratios (90/10-50/50). The phase inversion takes place when the PEO content is 50 wt.% in the blend. Both the thermal stability and the tensile properties of plasticized-starch are improved by blending with PEO. Also, a synergistic effect between plasticized-starch and PEO is noticed at 25-40 wt.% PEO content in the blend, the Young's modulus of the materials obtained being the highest and higher than both neat polymer components at those blending ratios., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Novel bionanocomposites based on halloysite nanotubes as nanofillers and plasticized starch as polymeric matrix were successfully prepared by melt-extrusion for the first time. Both modified and non modified halloysites were added at different weight contents. The structural, morphological, thermal and mechanical properties of plasticized starch/halloysites nanocomposites were investigated. Melt-compounding appears to be a suitable process to uniformly disperse nanotubes in the plasticized starch matrix. Interactions between plasticized starch and halloysites in the nanocomposites and microstructure modifications were monitored using Fourier transfer infrared spectroscopy, X-ray diffraction and dynamic mechanical analysis. Addition of halloysite nanotubes slightly enhances the thermal stability of starch (onset temperature of degradation delayed to higher temperatures). The tensile mechanical properties of starch are also significantly improved (up to +144% for Young's modulus and up to +29% for strength) upon addition of both modified and unmodified halloysites, interestingly without loss of ductility. Modified halloysites lead to significantly higher Young's modulus than unmodified halloysites., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Poly(2-hydroxyethylmethacrylate) films incorporated with titanium dioxide nanoparticles were successfully synthesized by an in situ sol-gel process. The in vitro bioactive properties of the films were assessed after immersion in simulated body fluid for up to 21 days through biomimetic method. Hydroxyapatite formation was observed on the surfaces of nanocomposites. This indicates that prepared composites are bioactive. Fourier transforms infrared spectroscopy, X-ray diffraction patterns, X-ray photoelectron spectroscopy and scanning electron microscope images confirm the hydroxyapatite formation on nanocomposite. The present study provides an analytical method for the assessment of titanium dioxide nanoparticles filled poly(2-hydroxyethylmethacrylate) polymer nanocomposites for biomedical applications.