Three-dimensional bioprinting has emerged as a promising technique in tissue engineering applications through the precise deposition of cells and biomaterials in a layer-by-layer fashion. However, ...the limited availability of hydrogel bioinks is frequently cited as a major issue for the advancement of cell-based extrusion bioprinting technologies. It is well known that highly viscous materials maintain their structure better, but also have decreased cell viability due to the higher forces which are required for extrusion. However, little is known about the effect of the two distinct components of dynamic modulus of viscoelastic materials, storage modulus (G′) and loss modulus (G″), on the printability of hydrogel-based bioinks. Additionally, 'printability' has been poorly defined in the literature, mostly consisting of gross qualitative measures which do not allow for direct comparison of bioinks. This study developed a framework for evaluating printability and investigated the effect of dynamic modulus, including storage modulus (G′), loss modulus (G″), and loss tangent (G″/G′) on the printing outcome. Gelatin and alginate as model hydrogels were mixed at various concentrations to obtain hydrogel formulations with a wide range of storage and loss moduli. These formulations were then evaluated for the quantitatively defined values of extrudability, extrusion uniformity, and structural integrity. For extrudability, increasing either the loss or storage modulus increased the pressure required to extrude the bioink. A mathematical model relating the G′ and G″ to the required extrusion pressure was derived based on the data. A lower loss tangent was correlated with increased structural integrity while a higher loss tangent correlated with increased extrusion uniformity. Gelatin-alginate composite hydrogels with a loss tangent in the range of 0.25-0.45 exhibited an excellent compromise between structural integrity and extrusion uniformity. In addition to the characterization of a common bioink, the methodology introduced in this paper could also be used to evaluate the printability of other bioinks in the future.
Curcumin is a pharmacologically active polyphenol derived from the popular spice element-Turmeric. The therapeutic activity of curcumin has been extensively investigated over the last few decades and ...reports suggest the role of curcumin in a large number of biological activities, particularly its prominent anticancer activity. Curcumin, being a pleiotropic molecule, is a regulator of multiple molecular targets which play crucial roles in various cell signaling pathways. It is known to suppress transformation, inhibit proliferation as well as induce apoptosis. However, despite all these benefits, the efficacy of curcumin remains limited due to its poor bioavailability, poor absorption within the systemic circulation and rapid elimination from the body. To overcome these limiting factors, researchers all around the world are working towards designing a synthetic and superior curcuminoid by making suitable structural modifications to the parent skeleton. These curcuminoids, mainly analogues and derivatives, will not only improve the physicochemical properties but also enhance the efficacy simultaneously. The present review will provide a comprehensive account of the analogues and derivatives of curcumin that have been reported since 2014 which have indicated a better anticancer activity than curcumin.
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•Curcumin, a pleiotropic phytochemical, is at the forefront of natural product research.•A number of limitations restrict its usage as an effective drug molecule.•Structural modifications to overcome these limitations have proven to improve activity.•This review summarizes the modified curcumin reported with improved anticancer activity over the last five years.
3D bioprinting strategies in tissue engineering aim to fabricate clinically applicable tissue constructs that can replace the damaged or diseased tissues and organs. One of the main prerequisites in ...3D bioprinting is finding an appropriate bioink that provides a tissue‐specific microenvironment supporting the cellular growth and maturation. In this respect, decellularized extracellular matrix (dECM)‐derived hydrogels have been considered as bioinks for the cell‐based bioprinting due to their capability to inherit the intrinsic cues from native ECM. Herein, a photo‐crosslinkable kidney ECM‐derived bioink (KdECMMA) is developed that could provide a kidney‐specific microenvironment for renal tissue bioprinting. Porcine whole kidneys are decellularized through a perfusion method, dissolved in an acid solution, and chemically modified by methacrylation. A KdECMMA‐based bioink is formulated and evaluated for rheological properties and printability for the printing process. The results show that the bioprinted human kidney cells in the KdECMMA bioink are highly viable and mature with time. Moreover, the bioprinted renal constructs exhibit the structural and functional characteristics of the native renal tissue. The potential of the tissue‐specific ECM‐derived bioink is demonstrated for cell‐based bioprinting that could enhance the cellular maturation and eventually tissue formation.
This study aims to develop a novel photo‐crosslinkable kidney‐specific extracellular matrix (ECM)‐based bioink formulation that can support the human kidney cell maturation and tissue formation in the printed construct. 3D bioprinting strategy with this novel kidney‐specific ECM bioink has great potential to bioengineer a functional renal tissue construct for use in future regenerative medicine applications.
In the present work CO2 adsorption isotherms of a commercially available activated carbon, Norit Darco type obtained from lignite granular material, were measured. Adsorption isotherms were measured ...at different temperatures 298 K, 308 K, 318 K and 338 K and over a pressure range of 0–45 bar using Sievert's type experimental setup. Experimental data of CO2 adsorption isotherms were modelled using Langmuir and Dubinin–Astakhov (D–A) isotherm models. Based on coefficient of correlation and normalized standard deviation it was found that D–A isotherm model was well suited with the experimental data of CO2 adsorption isotherms. The important thermodynamic properties viz., limiting heat of adsorption at zero coverage, entropy, Gibbs free energy and isosteric heat of adsorption as a function of surface coverage were evaluated using van't Hoff and Clausius–Clapeyron equations. These thermodynamic properties were indicating that CO2 uptake by activated carbon is a physisorption phenomenon. The adsorption isotherms data and the thermodynamic parameters estimated in the present study are useful for designing of an adsorption based gas storage systems.
Curcuma longa L., its derived extracts and even its major compound curcumin has a long history of use and doubtless effectiveness, reported through increasingly detailed in vitro, ex vivo, in vivo ...and even clinical trials. Regarding its biological effects, multiple health-promoting, disease-preventing and even treatment attributes has been remarkably highlighted. Clinical trials, although have increased in a progressive manner, significant disproportionalities have been stated in terms of biological effects assessment. In this sense, the present report aims to provide an extensive overview to curcumin therapeutic effects in human subjects. For that, clinical trials assessing the curcumin effect on inflammation, skin, eye, central nervous system, respiratory, cardiovascular, gastrointestinal, urogenital and metabolic disorders are here presented and discussed. A special emphasis was also given to curcumin activity on intoxications and multiple malignant diseases.
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•Curcuma longa L., and its main bioactive constituent, curcumin, have a wide spectrum of biological potentialities.•Promising in vitro and in vivo therapeutic effects have been markedly reported.•Curcumin therapeutic effects in human subjects are carefully discussed here.•Curcumin anti-inflammatory and cardioprotective effects are the most often investigated.•Renowned benefits on malignant diseases, gastrointestinal and central nervous system have also been demonstrated.
Electric vehicles (EVs) have become a viable solution to the emerging global climate crisis. Rechargeable battery packs are the basic unit of the energy storage system of these vehicles. The battery ...thermal management system (BTMS) is the primary control unit of the energy source of the vehicles. EV performance is governed by specific power, charging/discharging rate, specific energy, and cycle life of the battery packs. Nevertheless, these parameters are affected by temperature, making thermal management the most significant factor for the performance of a battery pack in an EV. Although the BTMS has acquired plenty of attention, research on the efficiency of the liquid cooling-based BTMS for actual drive cycles has been minimal. Liquid cooling, with appropriate configuration, can provide up to 3500 times more efficient cooling than air cooling. Direct/immersive and indirect liquid cooling are the main types of liquid cooling systems. Immersive/direct cooling utilizes the technique of direct contact between coolant and battery surface, which could provide larger heat transfer across the pack; however, parameters such as leakage, configuration, efficiency, etc., are needed to be considered. Indirect cooling techniques include cold plates, liquid jackets, discrete tubes, etc. It could result in complex configuration or thermal non-uniformity inside the pack. The paper intends to contribute to the alleviation of these gaps by studying various techniques, including different configurations, coolant flow, nanoparticles, varying discharging rates, different coolants, etc. This paper provides a comprehensive perspective of various techniques employed in liquid cooling battery packs, identifying the shortcomings in direct/immersive and indirect liquid cooling systems and discussing their mitigation strategies.
The dual stage ignition biomass downdraft gasifier is the promising technology for huge tar reduction, based on two experimental approaches such as single stage and dual stage ignition. The whole ...unit has been tested with gradually increasing electric resistive load from 15.24 kW to 38.86 kW with a useful energy output of nearly 86.41 %. In single stage ignition approach, the hot air is only supplied at the combustion zone through a nozzle, while the two-stage ignition approach has supply of the premixed gas (hot air plus producer gas) at the pyrolysis zone for partial combustion. In dual stage ignition, the enhanced quality of producer gas comes from 56 % combustible gas with the HHV of 6.415 MJ/Nm3, while the biomass consumption rate is 59 kg/h at the maximum load with grate temperature of 1310−1360 °C. The tar content after gas cooling and cleaning unit is 8 mg/Nm3 with 15 % improvement in efficiency.
Currently, enormous attention is being paid to the difficult design and synthesis of hierarchical nanosheet structures for high-performance supercapacitors. In the present study, we have explored ...electrochemically synthesized nanostructures of free standing NiCo2O4@NiCo2O4 composite electrode interconnected hierarchical nanoplates, and NiCo2O4 connected hierarchical nanowires were directly grown on a high conductivity Ni foam substrate as an electrode for supercapacitor applications through a cost effective and simple chemical bath deposition method. The electrochemical properties were investigated via cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy studies. This optimized NiCo2O4@NiCo2O4 nanoplate electrode delivered a remarkable specific capacitance of 2800 F g−1 at a current density of 35 A g−1, which is higher than that of the NiCo2O4 nanowire electrode (1200 F g−1 at 35 A g−1) in 3 M KOH aqueous solution, with good electrochemical and superior cycling life properties because of its higher conductivity, broad surface area and the mesopores on its walls. The NiCo2O4@NiCo2O4 nanoplate composite electrode is directly grown on the high conductivity Ni foam substrate with NiCo2O4 nanowires to support efficient electrocatalytic oxidation reactions. The mesoporous features of the NiCo2O4@NiCo2O4 nanoplate electrode enhance the properties through fast electron/ion transfer and enhance the utilization of the electrode material and large number of electroactive sites. All these results indicate that the NiCo2O4@NiCo2O4 nanoplate composite electrode would be a promising positive electrode material for flexible electrochemical capacitors.
Fuel cells have substantial development potential for commercial energy generation applications. Adding an ionic conducting electrolyte to a cathode to make a composite cathode lowers the Thermal ...Expansion Coefficient (TEC), raises the Triple Phase Boundary (TPB) area, and enhances the electrochemical performance of Solid Oxide Fuel Cells (SOFCs). In this review, the article presents the basic principles, criteria, and composite cathode development of SOFCs that operate SOFCs in the intermediate temperature ranges (600–800 °C). These composite cathodes improve the inter-component compatibility, Oxygen Reduction Reaction (ORR), and characteristics of mixed electronic-ionic conductors. In comparison with a single-phase cathode, composite material can reduce Polarization Resistance (Rp) by about 30–40% and improve maximum power density (MPD) by about 30–50%. PBCO-40SDC and SBCN-20SDC composites exhibit enhanced stability and maintain their electrochemical performance with polarization resistances of 0.008 Ω cm2 and 0.079 Ω cm2 when operating at temperature of 700 °C.
•Recent methods in IT-SOFC composite cathode development were explored.•Properties of nine materials studied, including conductivity and stability.•PBCO-40SDC outperforms with low polarization resistance at 700 °C.•Noteworthy development: exsolution of catalytically active nanoparticles.•Comprehensive study on thermal, electrical, and catalytic properties.
The development of combined simple metal oxides and binary metal oxides on a flexible conductor has been needed as a novel approach for energy storage sources. Here, we demonstrate a simple and ...versatile strategy towards the synthesis of a NiZn2O4–NiO nanoflower array (NFA) composite effectively deposited into a nickel (Ni) foam conductor for energy storing applications to achieve better electrochemical results. The morphology and other physical properties of the as-developed composite were analyzed, and the results suggest that the NiO nanoparticles have been effectively anchored into the binary NiZn2O4 nanoleaves array surface. The composite NiZn2O4–NiO NFAs nanoarchitecture combines superior surface area with huge numbers of active sites to boost electrochemical reactions and excellent transport between electrons and ions, as compared to NiZn2O4 nanoleaf arrays (NLAs). Meanwhile, taking into consideration electrochemical studies, the composite NiZn2O4–NiO NFAs exhibited extraordinary faradaic redox progress, which was different from the metal oxide based electrode profiles. Cyclic voltammetry and galvanostatic charge–discharge plateaus from the NiZn2O4 NLAs and NiZn2O4–NiO NFAs electrodes exhibit faradaic battery-type redox behavior, which is distinct from the profiles of carbon-based materials. As a battery-type electrode, the composite NiZn2O4–NiO NFAs electrode exhibited a greater supercapacitor activity with a higher specific capacitance of 482.7 C g−1 at 1 A g−1 and also yielded the best life-span with up to 98.14% capacity retained after 5000 cycles (vs. 253.4 C g−1 at 1 A g−1 and 91.4% retention of capacity after 5000 cycles for NiZn2O4 NLAs), which was the best result or comparable to recently reported composites of simple metal oxides/binary metal oxides-based electrode materials. Thus, with the above findings, the battery-type NiZn2O4–NiO NFAs electrode material has remarkable application potential and could be effectively applied in other energy storage technologies.
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