Abstract: The Blood-Brain Barrier (BBB), a unique structure in the central nervous system (CNS), protects the brain from bloodborne pathogens by its excellent barrier properties. Nevertheless, this barrier limits therapeutic efficacy and becomes one of the biggest challenges in new drug development for neurodegenerative disease and brain cancer. Recent breakthroughs in nanotechnology have resulted in various nanoparticles (NPs) as drug carriers to cross the BBB by different methods. This review presents the current understanding of advanced NP-mediated non-invasive drug delivery for the treatment of neurological disorders. Herein, the complex compositions and special characteristics of BBB are elucidated exhaustively. Moreover, versatile drug nanocarriers with their recent applications and their pathways on different drug delivery strategies to overcome the formidable BBB obstacle are briefly discussed. In terms of significance, this paper provides a general understanding of how various properties of nanoparticles aid in drug delivery through BBB and usher the development of novel nanotechnology-based nanomaterials for cerebral disease therapies.

Abstract: This paper presents the thermal and mechanical properties of bamboo fiber reinforced composite (BFRC) derived from Gigantochloa scortechinii. The bamboo fibers were prepared through chemical treatment by sodium hydroxide (NaOH) followed by physical milling method. The thermal characteristics of the bamboo fiber and its polymer composite were analysed using a thermogravimetric analysis and differential scanning calorimetric. The functional groups and crystallinity of the fiber were analysed with Fourier transform infrared and x-ray diffraction spectroscopy. Meanwhile, the fiber morphology was examined using a scanning electron microscope. The BFRCs with fiber volume fractions ranging from 0 % to 40 % embedded in three thermoset resins (epoxy, polyester, vinyl ester) were subjected to tensile and flexural tests and the fracture pattern was examined. The NaOH concentration of 10 % with soaking duration of 48 h was found to produce a bamboo fiber with the highest ultimate tensile and modulus strength. The tensile and flexural properties of all the BFRCs were found to be directly proportional to the fiber volume fractions. It was found that the bamboo fiber reinforced epoxy composite (BFREC) with 40 % fiber volume fraction exhibited the highest tensile and flexural strength compared to polyester and vinyl ester composites. The method of bamboo fiber composite preparation in this work may serve as a useful guide to produce a strong BFRC for external strengthening of buildings and structures.

Abstract: Since their first synthesis, carbon nanotubes (CNTs) gained remarkable research interest owing to their astonishing mechanical properties and extensive range of potential applications in various sectors, such as aerospace, automobile, biomedical, defence, energy, etc. This paper covers numerous characterization techniques, synthesis approaches and properties of the CNTs, reported by earlier researchers in the past. The technological and industrial needs for the development of lightweight nanocomposites have led to the significant advancements in the preparation of CNT-reinforced composites. In preliminary sections, the properties and applications of the CNT-reinforced nanocomposites are elaborated along with the issues related to their preparation. Here, various nanotubes synthesis processes, such as arc discharge, laser ablation and chemical vapour deposition, are exemplified with the support of published works. Furthermore, we have also addressed the several surface modification techniques of CNTs, such as purification, functionalization and dispersion, which make this review novel and exhaustive. In order to address the limitations and challenges incurred during the preparation of various CNT-reinforced polymer/metal matrix composites, an extensive collection of the published literature is reported and discussed, thoroughly. Based on this exhaustive review, some specific observations are made which would facilitate upcoming researches to explore the research opportunities in the preparation of CNTs and CNT-reinforced composites and their potential applications for the high-performance structures/components.

Abstract: To make perovskite solar cells an industrially relevant technology large area deposition techniques are needed and one of the most promising is slot-die coating. This review article details the progress reported in the literature where slot-die coating has been used for the deposition of both the perovskite layer and other layers in the perovskite solar cell device stack. An overview of the methods used to adapt the coating process, materials and drying conditions in order to create high quality layers and devices is given and an outlook on future research directions in this field is made.

Abstract: In order to improve the impact energy absorption abilities and maintain good crushing load uniformity of auxetic honeycombs, a re-entrant arc-shaped honeycomb (RAH) model is proposed according to the concept of bio-inspired structure design. The in-plane impact resistances and absorbed-energy characteristics of bio-inspired auxetic RAHs subjected to a constant velocity crushing are numerically studied by using ABAQUS/EXPLICIT. It is shown that due to the introduction of re-entrant arc-shaped structures, the dynamic response curves of bio-inspired RAHs have better crushing load uniformity than conventional re-entrant honeycombs. Except for the relative density and impact velocity, the dynamic crushing behaviors of bio-inspired RAHs also depend upon the cell micro-structure parameters (e.g., the curvature). Based on the one-dimensional (1D) shock theory and absorbed-energy efficiency method, an empirical equation is deduced to evaluate the dynamic plateau stress of bio-inspired RAHs. The finite element (FE) results coincide well with those calculated by the empirical formulas. Moreover, the specific energy absorption (SEA) and energy dissipation rules of bio-inspired RAHs are discussed, which are also dependent on the curvature. These researches will provide technical support for the innovative structure design and dynamic optimization design of auxetic cellular structures.

Abstract: Large bone defects, which occur due to various causes, have substantially affected people's health and quality of life. Bone tissue engineering (BTE) is a promising approach for repairing or replacing bone injuries. The aim of BTE scaffolds is to mimic the biological function and structure of the natural bone extracellular matrix (ECM), which provides a three-dimensional (3D) environment for cell adsorption, proliferation and differentiation. Significant advances in materials science, computer-aided design (CAD) and biomedical engineering have facilitated BTE scaffolds. This paper describes the requirements of BTE scaffolds and highlights the important role of additive manufacturing (AM) technologies in building bridges between biomaterials, CAD models and additives, and BTE scaffolds. It reviews various AM technologies that are used to fabricate BTE scaffolds. These technologies are divided into seven categories: (1) stereolithography (SLA), (2) powder bed fusion (PBF), (3) binder jetting (BJ), (4) material extrusion (ME), (5) material jetting (MJ), (6) volumetric printing (VP) and (7) 4D printing (4DP). The characteristics, raw materials, accuracy, cost, advantages and disadvantages of the AM technologies are discussed. Several recommendations for future research are presented.

Abstract: Several additive manufacturing (AM) methods use powder feed materials. Selective laser sintering is an example of a versatile AM method, using feed material in powder form, capable of producing polymer and metallic parts. In the variations of this technique, a laser spot or an electron beam is used to locally sinter or melt a packed powder bed. After the completion of sintering on each layer, further powder is added on top of the existing bed so that the next layer may be joined. A major challenge in this method is controlling the porosity of the powder bed so that the final part has uniform and maximum density. Uniformity in the packing of bed from one layer to the other is important for optimizing the processing parameters. This review is focused on considering the packing characteristics of polydisperse hard particle beds and the determination of the expected density achievable for a given particle size and shape distribution. Models are presented for discrete mixtures as well as continuous distributions. The effect of the initial configuration of a particle bed on its ability to form a highly dense packing is also discussed. Blending of different particle sizes and shapes can be used to substantially increase the packing density, but can also lead to separation or segregation of the bed. Through appropriate control of the particle shape and use of wide distributions, packing densities close to 100 % can theoretically be achieved, but practicality and various effects that appear at small size scales prevent from achieving such high packing densities. Recent advancements have reduced the dependence of AM part quality on the density of the packed particle bed but the packing is still important for considerations such as thermal conductivity of the bed and absorption of laser power in the bed. Improved knowledge of packed bed characteristics can be helpful in developing AM methods for novel material systems.

Abstract: Solution blow spinning (SBS) is a maturing nanofiber fabrication technology. Over the past decade, there has been a growing interest in employing and developing this facile method of fabricating nanofibers, sourced from different materials to suit varied applications. For the first time, this review will provide a comprehensive overview of solution blow spinning, including the principles, materials, methods, and applications. We start with the principles of the SBS method, followed by a detailed account of the different precursor polymers (i.e., synthetic, biocompatible, and bio-based materials) and composites that have been used in the SBS of nanofibers. The proceeding section presents the known applications of nanofibers obtained through SBS which are discussed primarily in the areas of energy and electronics, biomedical, environmental, membrane separation, and, textile and smart material applications. We highlight the most important and recent advances related to SBS over the last ten years. Lastly, we give perspectives, challenges, opportunities, and new directions of the SBS technology.

Abstract: Molybdenum-based supercapacitors, a fast promising area where researchers are exploring the possibilities of improving the performance of its electrode materials and their derivatives for energy storage. Molybdenum sulfide (MoS2) has attracted considerable interest because of its superior properties as a supercapacitor-based material. In this mini-review, the wet-chemical methods of preparing MoS2 and their electrochemical properties were summarized. The preparation methods and their composite substrates of MoS2 based supercapacitors have been highlighted to be one of the determining factors for improving the electrochemical output being reported. This review suggested that the modified methods of preparation and appropriate composite materials can enhance the supercapacitor properties of MoS2 based materials. Finally, we explore the future opportunities for advance storage potential presented by MoS2 based materials.

Abstract: In the present work, processing and hot corrosion behaviour of Inconel718-nano-Al2O3 based composite coatings with varying nano-Al2O3 contents (10, 20 and 30 wt. %) was studied. The nano-Al2O3 powders were synthesised by using manual granulation technique. The composite coatings were deposited on grey cast iron (GCI) substrate by using a high-velocity oxy-fuel process (HVOF). Hot corrosion behaviour of bare and coated specimens was determined at 900 °C in a high-temperature furnace for 50 h. The weight change data was used to establish the oxidation kinetics of bare and coated specimens. The coating with the highest proportion of nano-Al2O3 content exhibited the maximum hardness and corrosion resistance. The nano-sized alumina particles enhanced the hardness of the coatings by posing a higher constraint to the plastic deformation during the indentation. The presence of nano-Al2O3 and various protective oxides (Cr2O3, NiCr2O4, and TiO2) resulted in the improved corrosion resistance of coatings in comparison to the GCI substrate.

Abstract: We have investigated the formation of self-organized titanium oxide nanotube layers by anodic oxidation on titanium alloys in electrolyte solutions with different temperatures (5, 10, 25, 30, 50 and 70 °C). Pore diameter and the wall thickness of nanotube arrays were controlled by varying anodization time and temperature. We have observed significant outcomes in the formation of TiO2 nanotube arrays at 25 °C with an average inner pore diameter of 125 nm, length of ∼250 nm, the wall thickness of 30 nm and an inter-tube space 35 nm. Nanotube arrays were smooth and circular without any defect in morphology. In addition, anodization of Commercially Pure Titanium (CP Ti) and titanium alloys (Ti-6Al-4 V, Ti-6Al-7Nb, Ti-13Nb-13Zr, and β-21 s) was carried out at optimized parameter to understand their significance on TiO2 nanotube arrays formation.

Abstract: Interlaminar fracture or delamination is one of the major failure modes for fiber reinforced polymer (FRP) and fiber metal laminate (FML) composites. Many studies have been carried out to investigate the mechanisms affecting this interlaminar failure and ways to improve the interlaminar fracture toughness (ILFT) of FRP composites and FMLs. However, information on the topic is scattered, with studies having different emphases. Therefore, in this review, the studies are surveyed and put into perspective in terms of the improvements to ILFT achieved. A wide range of methods to improve the ILFT of FRP composites and FMLs is presented. For FRP composites, the methods include modifications to the constituents or interlaminar regions of the composite, applications of nano-fillers in multiscale composites approaches, and through thickness reinforcement techniques. For FMLs, studies on various surface treatment methods for the metal in FMLs are included. The strengthening mechanisms involved in each of the methods are also discussed. This review provides a comprehensive picture of the different methods to improve interlaminar interfaces in laminated composites, including their performances and drawbacks, as well as the future trends in the related topics.

Abstract: The featured work reports the preparation, characterization and various properties of melanin nanoparticle (MNP) reinforced cellulose nanofiber (CNF) based nanocomposite films. The CNF was extracted using a combination of chemical and physical methods. The MNP was isolated from a natural source sepia ink by following a simple centrifugation technique and used as a functional nanofiller to fabricate the CNF/MNP nanocomposite films. The prepared nanocomposite films were characterized in terms of morphology, structure, chemical interactions, optical properties, surface hydrophobicity, mechanical properties, thermal stability and antioxidant activity. The MNP was shown to be evenly dispersed in the CNF matrix and biocompatible with cellulose matrix to form the nanocomposite films. Incorporation of MNP enhanced the ultraviolet blocking, mechanical properties, hydrophobicity and water vapor barrier properties of the nanocomposite films. The developed nanocomposite films also showed strong antioxidant activity. The crystalline structure, crystallinity and thermal stability of the nanocomposite films were not affected meaningfully. The sepia ink isolated MNP has a very good prospective to be used as a nanofiller for the preparation of CNF based nanocomposite films.

Abstract: Compared to graphene, graphene oxides (GO) have also been applied in many areas due to their unique structures and properties, such as tunable and functionalized surfaces, great processing and competition for scalable production. In this review, GO reinforced epoxy resins are systematically looked into, where they can be classified into two broad groups: epoxy/GO nanocomposites and epoxy/GO coatings, depending on the application types. In the epoxy/GO nanocomposites, the GO reinforcement on the different properties of epoxy matrices are described in details, like mechanical, toughness, thermal conductivity and so on. As for the epoxy/GO coatings, the GO effect on the anti-corrosion properties is one of the main concerns. For both of them, GO modification methods and dispersing routes in the respective epoxy matrices are among the most important considerations. There are some remaining unsolved issues, which will be highlighted together with the future perspectives of the GO reinforced epoxy resins.

Abstract: Magnolia kobus DC. (M. kobus), a prominent Southeast Asian flowering plant species, was investigated for its inhibition efficiency against mild steel corrosion in 1 M H2SO4. The extract (M. kobus) was identified to have 145.80 μg/g of myricetin and 102.32 μg/g syringic acid as prominent components, with a total phenolic content (TPC) of 95.26 mg/g and a total flavonoid content (TFC) of 25.38 mg/g. The mass-loss measurements showed that 500 ppm of M. kobus extract was able to inhibit corrosion, with an efficiency of 95.01% at 303 ± 1 K. Reduction of dissolved iron content in the inhibited solution than in the inhibitor free solution observed in Atomic Adsorption Spectroscopy (AAS) revealed the corrosion mitigating effect of inhibitor on mild steel. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) analysis of the protected and unprotected mild steel samples indicate adsorption of M. Kobus on the electrode surface. UV–vis and FT-IR studies complement the above results. The electrochemical studies indicated that M. kobus functioned as a mixed-type indicator and myricetin along with other plant components present in the plant extract contributed to the inhibition process.

Abstract: Nanofiltration (NF) has emerged as a potentially superior and cost-effective way to remove sediments, charged particles, chemical effluents, bacteria and other pathogens in addition to removal of toxins like arsenic or impurities such as oils. Important properties intrinsic to NF membranes include high permeation to monovalent ions, low permeation to divalent ions and higher flux than reverse osmosis membranes. In addition, NF membranes offer advantages over other membranes due to increased reliability and integrity, producing longer cycle times and hence lower costs. Due to these characteristics, NF membranes have been used in a wide range of applications, including water treatment, agri-food, biotechnology and pharmaceutical industries. In this review, we present some of the most recent and impactful advances in NF area, detailing new membrane materials and processes as well as their new potential applications. The future developments of NF uses, involving new 2-dimensional (2D) nanomaterials, such as graphene, graphene oxide, boron nitride (BN) and atomic layered transition metal dichalcogenides (TMDs), are also discussed.

Abstract: In this study, Eucalyptus globulus essential oil was used in green synthesis of Zinc oxide nanoparticles. After extraction of essential oil from leaves by hydrodistillation, it was mixed with Zinc acetate dihydrate to prepare ZnO nanoparticles. XRD, DLS, FTIR, SEM, TEM, EDX and UV-Vis were utilized to characterize the biosynthesized ZnO nanoparticles. X-ray diffraction analysis confirms the formation of single pure ZnO phase with an average crystallite size of 24 nm. SEM and TEM observations reveal irregular needle and spherical morphology with particle size at the nanoscale; meanwhile DLS analysis indicates a mean size around 40 nm. The antimicrobial activity was carried out by agar well diffusion method and by the determination of the minimum inhibitory concentration, whereas the anti-biofilm activity was investigated using 96-well microtiter plate method. The results indicate that ZnO NPs exhibit effective antimicrobial potential against all tested microorganisms with a maximum zone of inhibition of 19.35 ± 0.45 mm for K. pneumoniae at a concentration of 100 μg / ml. The significant percentage of biofilm inhibition was found 85% and 97% against S. aureus ATCC 25923 and P. aeruginosa ATCC 27853 biofilm, respectively. Possible mechanisms are proposed and discussed. This study demonstrates the importance of using essential oils for the easy and rapid green synthesis of ZnO nanoparticles with less use of toxic chemicals and exhibiting interesting biological activities with potential applications as efficient alternative to combat antibiotic resistance and eradicate bacterial biofilms from hospital environment.

Abstract: In this work, the hot deformation behavior of Alloy 925 with intermediate strain rates of 0.01s−1-10s−1 ranging from 900 °C to 1150 °C has been investigated through the isothermal hot compression tests. Some features of the flow curves corresponding to negative strain rate sensitivity have been observed and discussed associated with the microstructural evolution, showing the nucleation mechanism of dynamic recrystallization and the occurrence of dynamic strain ageing. Besides, we have employed two typical constitutive models, namely, Arrhenius model and backpropagation artificial neural network (BP ANN) model to describe the flow behavior, and also developed a modified BP ANN model based on genetic algorithm (GA-BP ANN). The results show that the GA-BP ANN model has the highest accuracy and stability for predicting the flow stress. The correlation coefficient between the predicted and experimental values is 99.99 %, and the average absolute relative error is only 0.54 %. The comparative investigation on the predicted values of different ANN models reflects that GA can reduce the randomness of initial weights and thresholds of BP ANN and also can further increase the accuracy and stability of ANN model. Moreover, the increasing number of input training data can improve the prediction performance of neural network. For a single-layer neural network, 12 hidden layers can effectively ensure the reliability of the constitutive model.

Abstract: The supercapacitor, which has been attracting growing interest in energy-storage applications since the past decade, is an alternative that evinces the potential to emulate future battery technology. To achieve this decisive task, it is essential that electrode materials with high energy density and electrochemical stability are explored for environment-friendly and economical utilization. Numerous studies have been conducted on metal-based compounds and their composites; among them, bismuth-based materials and their composites are promising because of their redox behavior, charge storage capacity, environmental friendliness, and increasing research toward their application in energy storage for batteries and supercapacitor technologies. Herein, we outline bismuth materials and their composites, as investigated by researchers, highlight their applications in energy storage, and, more importantly, focus on the study of their supercapacitive performance via electrochemical techniques. To better understand their charge storage mechanism and electrochemical performance, we also present a summary of energy storage devices and their mechanisms, as well as other types of non-bismuth-based electrode materials available in the market. In addition, the major challenges and future perspectives of bismuth-based composites for energy storage purposes are discussed.

Abstract: Bone injuries can be treated using tissue engineering scaffolds, but the conventional constructs have a big challenge in supplying requirements of native tissue, i.e., bioactivity potential, mechanical stability, controllable biodegradability, and proper cellular interaction. In this regard, 3D printing technology with the possibility of controlling the internal microstructure and geometry of synthesized matrixes was introduced as a promising approach for bone defect regeneration. Although a variety of novel materials, which have shown initial potential for bone repair, can be used for preparing the biocompatible matrixes, the 3D printer type and selecting an innovated technology depend on the properties of applied biomaterials. In all the used methods, tunable, controllable, and interconnected porous microstructure can be fabricated even though identification of suitable porosity and microstructure, which can supply required mechanical properties of natural bone and support cellular adhesion, proliferation, and differentiation, need to evaluate. Therefore, this mini-review explains current advances in acellular 3D printed scaffolds, proper microporous structure and geometry for bone repair, and suitable materials for 3D printing the regenerative bone substitutes. Herein, the novel and recent studies were focused and probable limitations, and existing strategies were discussed.

Abstract: Chitosan is a natural polysaccharide with unique physical, chemical and biological properties that potentiates its use in many biomedical applications. In this study, chitosan thin film was doped with different concentrations of green synthesized silver nanoparticles (AgNPs) (100−400 μg) to improve its mechanical and antimicrobial activity. Transmission electron microscopy (TEM), UV–vis absorption spectroscopy and dynamic light scattering (DLS) were used to characterize the silver nanoparticles. The silver-doped chitosan films were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) in addition to assessment of their mechanical and antimicrobial properties. The characterization results revealed the successful formation of spherical silver nanoparticles with a size distribution of 100 nm ± 40 nm. The mechanical properties of chitosan film doped with silver nanoparticles (300, 400 μg) showed superior mechanical properties over pure chitosan film. Compared with pure chitosan film, silver nanoparticles doped chitosan films showed significant antibacterial activity against Staphylococcus aureus. Chitosan film doped with 300 μg AgNPs showed significant antifungal activity against Candida albicans compared with pure chitosan. Accordingly, doping of chitosan film with silver nanoparticles greatly improves its mechanical properties and antimicrobial activity.

Abstract: Metal additive manufacturing is increasingly utilised for the production of customised components Post-process operations are required to address the high surface roughness of as-built components which is detrimental for load-bearing applications Parts produced by metal additive manufacturing often have complex- surfaces and geometrical features rendering mechanical finishing processes impractical This study investigates the chemical polishing of laser powder bed fusion (LPBF) produced Ti6Al4V axial fatigue test specimens in HF-HNO3 solutions with different initial HF concentrations (1, 2, and 4 M) and a constant initial HNO3 concentration (317 M) Polishing efficacy was evaluated in terms of mass removal, surface roughness reduction, and resulting tension-tension fatigue strength The 4 M HF solution resulted in both the highest mass removal and surface roughness reduction; however, when evaluated relative to resource consumption, the processing efficiency decreases more drastically than that of the 1 and 2 M HF solutions Specimens polished in all three solutions had higher fatigue strengths and fewer surface crack initiation sites than the as-built condition Specimens polished in 2 M solutions exhibited better fatigue performance than specimens polished in 1 M solutions while statistical significance was lacking between the fatigue strengths of specimens polished in 2 M and 4 M solutions

Abstract: Silver and iron nanoparticles was synthesized, characterized and investigated for biological screening using alcoholic blumea eriantha DC plant extract. Equal amount of plant extract was mixed and incubated with silver nitrate and ferric chloride to obtain silver and iron nanoparticles respectively. Formation of silver and iron nanoparticles was confirmed by using UV, FT-IR spectroscopy, SEM, X-ray diffraction, and TEM. The anti-oxidant, antimicrobial, cytotoxic activities of the synthesized nanoparticles were determined by using standard protocols. MCF-7 cells were treated with selected concentrations of extract and prepared nanoparticles. It was observed that the synthesized nanoparticles were spherical in shape with an average particle size of 50 nm. The results of the studies revealed that the synthesized nanoparticles exhibited effective antioxidant, antibacterial and cytotoxic activity. The cell viability was measured for 50 hours after the addition of selected concentration of nanoparticles. The inhibition rate of silver nanoparticles was observed to be 15.45, 20.25 and 28.16 % against concentration 25, 50 and 100 μg mL-1 respectively. DPPI staining and Annexin V FITC assay results indicated that silver nanoparticle induce apoptosis in MCF-7 cells as compared with control. Therefore, it may open up a new avenue for anticancer therapies that needs further research.

Abstract: Biomaterial-based hydrogels incorporating antibacterial agents may provide sustainable solutions to biomedical device failures and the prevention of infections. Herein we report guar gum hydrogels, cross-linked with borax and loaded with silver nanoparticles, that are injectable, exhibit rapid self-healing, and show antibacterial properties towards both gram-positive and gram-negative bacteria. The hydrogels are fully characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and rheological measurements. An important focus was to minimize borax content, thus reducing the toxicity of the gels greatly, whilst retaining their favorable viscoelastic properties. When the low borax-content hydrogels are composited with curcumin-stabilized silver nanoparticles, the hydrogels show activity against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus).

Abstract: Due to the globally identified antibiotic resistance among clinical bacteria, novel antibacterial materials are needed to circumvent drug resistance. In this study, we report a facile synthesis method for the fabrication of a uniform silver (I) oxide (Ag2O) garnished graphene oxide (GO) nanocomposite (Ag2O/GO) using sonication and characterized them by X-ray diffraction (XRD), Raman spectroscopy, and UV–vis spectroscopy. Furthermore, the antibacterial properties of Ag2O, GO, and Ag2O/GO nanocomposite were studied using drug resistant Gram-negative Escherichia coli (ESBL), Pseudomonas aeruginosa (ESBL), Klebsiella pneumoniae and Gram-positive Staphylococcus aureus by well diffusion assay, colony forming ability, and cell membrane permeability assay. The nanocomposite (15.62−1000 μg/mL) showed excellent antibacterial activity with minimum inhibitory concentration of 125 μg/mL for P. aeruginosa and K. pneumoniae; 62.5 μg/mL for E. coli, and 250 μg/mL for S. aureus. Biofilm inhibition assay revealed the inhibition of biofilm formation in a dose related manner. Inhibition of biofilm formation by ½ MIC and MIC of Ag2O and Ag2O/GO against four pathogenic and biofilm forming bacteria was found statistically significant as P ≤ 0.05 (at ½ MIC) and P ≤ 0.01 (at MIC). These results demonstrated that these facile nanomaterials are promising antibacterial and antibiofilm agents that can be utilized to inhibit the growth of human bacterial pathogens associated with chronic infections.

Abstract: High-performance flexible pressure sensors with high sensitivity and large sensing range are vital components of the system for physiological signals collection, human-machine interaction and artificial intelligence. Herein, a flexible pressure sensor of copper nanowires/reduced graphene oxide/melamine foam (CuRGOMF) was fabricated by coating reduced graphene oxide (RGO) and in-situ growing of copper nanowires (Cu NWs) on the skeleton of melamine foam (MF). The as-prepared sensor features high sensitivity at wide working range (0.011 kPa−1, 0–1.5 kPa; 0.088 kPa−1, 1.5–10 kPa and 0.024kPa−1, 10–18 kPa) and cyclic stability (5000 cycles). The human motions of finger bending, grasping, clicking the mouse and picking up/dropping objects can be successfully detected in real-time based on the CuRGOMF sensor. The CuRGOMF sensor illustrates a promising candidate for healthcare monitoring and wearable device in artificial intelligence.

Abstract: The peculiar features of graphene like excellent physicochemical, electrical, large surface area and biocompatibility are revealing through the past decade, leading to continuous research on the use of graphene nanomaterial in various clinical applications and regenerative medicine. In this review, we highlighted the recent applications and challenges of graphene and its derivatives in stem cell proliferation, bone tissue engineering, neuronal proliferation and in biosensors. Graphene or graphene oxide has shown interesting results in angiogenesis, neuronal regeneration and immunomodulation in various in vitro and in vivo studies. Graphene based materials have a potential to be emerging as next generation nanomaterials. We discussed about the conventional procedures and related challenges in synthesis of graphene oxide. This review aims in summarizing the recent progresses of various graphene based nanomaterials and their hybrids in biomedical applications. Graphene as two dimensional, three dimensional and hybrids are attracting interest in biosensing and bioimaging. However, besides the fascinating properties of graphene, its biocompatibility and biodegradability related toxicities are still a question to researchers. Graphene nanomaterials use in various tissue scaffolds should be taken as an active area of interest by the researchers in near future. This review also enlisted the recent advancements of graphene as anticancer therapy and targeted drug delivery system. We hope the summary of this review inspires the researchers to conduct more studies on graphene based applications and its possible toxicities in humans, so that it can be implemented as cost effective and safe treatment to many pathological conditions.

Abstract: Aluminum matrix composites known for their superior mechanical properties finds its use as liners in engine cylinders, discs, drum brakes, and pistons in automotive applications. This paper investigates the influence of squeeze casting process parameters on AA6061/Al2O3/SiC/Gr hybrid metal matrix composite using the encapsulated feeding technique. Four levels of factors selected for the L16 orthogonal array to optimize the process parameters were squeeze pressure (60, 80, 100, 120 MPa), melt temperature (700,750,800,850 °C), die temperature (100, 150, 200, 250 °C) and pressure holding time (5, 10, 15, 20 s). Hardness and tensile strength were measured for the designed experiments. Scanning electron microscope with energy-dispersive X-ray spectroscopy identified surface morphologies and elemental analysis. Optimized results were predicted using the artificial neural network. The melt temperature and squeeze pressure exhibited a significant contribution in controlling the mechanical behaviour of the hybrid composites. Taguchi analysis suggested that SP3, MT2, DT4 and HT2 casting conditions presented the optimal process parameter level that showed the maximum hardness of 131 HV and the tensile strength of 329 MPa. Scanning electron microscopy and energy-dispersive X-ray spectroscopy showed uniform distribution of reinforcement in the encapsulation process compared with the regular feeding technique. ANN predicted the hardness and tensile strength with 95 % accuracy. Compared with the regression model and experimental data, the ANN prediction was more accurate. The defined hybrid metal matrix composite stands out as the substitute for AA6061 alloy that meets the demands of the modern automotive industry in engine cylinder liner applications.

Abstract: The current study focuses on the effective sulfonation of polyethersulfone (PES) polymer to synthesize sulfonated-polyethersulfone (SPES) and blending with PES to prepare SPES/PES blend membranes as well as preparation of cellulose acetate CA/PES blend membranes. FTIR-ATR technique was used to confirm the blending of SPES and CA into PES matrix. Water contact angle studies showed a significant reduction of hydrophobicity in SPES blend membranes (49.55 ± 1.52°) as compared with CA blend membranes (59.42 ± 2.20°) and PES base membranes (67.80 ± 1.48°). The presence of pores were analysed using scanning electron microscopy (SEM) where significant changes in the membrane morphology in the blend membranes were observed. Platelet adhesion, protein adsorption and activated partial thromboplastin time (APTT) studies were used to assess hemocompatibility of the membranes in which SPES/PES membranes exhibited improved characteristics as compared with its counterparts. The cytocompatibility of membranes were evaluated using water soluble tetrazolium (WST) assay which confirmed that both SPES/PES and CA/PES blend membranes exhibit better cytocompatibility than base PES membrane