The past decade has seen substantial growth in research into how changes in the biomechanical and biophysical properties of cells and subcellular structures influence, and are influenced by, the ...onset and progression of human diseases. This paper presents an overview of the rapidly expanding, nascent field of research that deals with the biomechanics and biophysics of cancer cells. The review begins with some key observations on the biology of cancer cells and on the role of actin microfilaments, intermediate filaments and microtubule biopolymer cytoskeletal components in influencing cell mechanics, locomotion, differentiation and neoplastic transformation. In order to set the scene for mechanistic discussions of the connections among alterations to subcellular structures, attendant changes in cell deformability, cytoadherence, migration, invasion and tumor metastasis, a survey is presented of the various quantitative mechanical and physical assays to extract the elastic and viscoelastic deformability of cancer cells. Results available in the literature on cell mechanics for different types of cancer are then reviewed. Representative case studies are presented next to illustrate how chemically induced cytoskeletal changes, biomechanical responses and signals from the intracellular regions act in concert with the chemomechanical environment of the extracellular matrix and the molecular tumorigenic signaling pathways to effect malignant transformations. Results are presented to illustrate how changes to cytoskeletal architecture induced by cancer drugs and chemotherapy regimens can significantly influence cell mechanics and disease state. It is reasoned through experimental evidence that greater understanding of the mechanics of cancer cell deformability and its interactions with the extracellular physical, chemical and biological environments offers enormous potential for significant new developments in disease diagnostics, prophylactics, therapeutics and drug efficacy assays.
Formaldehyde, HCHO, is one of the most common toxic pollutants found in indoor air. Its most common sources are pressed woods and particle boards. National Toxicology Program of Department of Health ...and Human Services classifies formaldehyde as human carcinogen and its exposure limit is 0.08 ppm for 30 min. So far, besides room venting, no other means have been recommended by Consumer Products Safety Commission to minimize indoor HCHO exposure. Since adsorption seems to be an efficient and cost-effective method of HCHO removal, in this review we summarize the findings on the applications of carbonaceous materials (mainly activated carbons, carbon fibers and their composites with an inorganic phase) as formaldehyde adsorbents from indoor air. Besides experiments, recent theoretical and simulation results are also discussed. Our intention is to use them as a basis for a further development of the next generation of efficient and cost-effective carbon-based reactive adsorbents where adsorption of HCOH will be combined with its mineralization at ambient conditions.
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Cancer Turns 75 Ramalingam, Suresh S.
Cancer,
1 July 2023, 2023-Jul-01, 2023-07-00, 20230701, Letnik:
129, Številka:
13
Journal Article
Recenzirano
Celebrating 75 years of publication, Cancer continues to serve as a beacon for scientific research that is fundamental to achieving cures for cancer. Heading into the future, the journal will ...continue to maintain its unique identity and strive to bring the best of science to the broadest of the audience.
The past decade has seen substantial growth in research into how changes in the biomechanical and biophysical properties of cells and subcellular structures influence, and are influenced by, the ...onset and progression of human diseases. This paper presents an overview of the rapidly expanding, nascent field of research that deals with the biomechanics and biophysics of cancer cells. The review begins with some key observations on the biology of cancer cells and on the role of actin microfilaments, intermediate filaments and microtubule biopolymer cytoskeletal components in influencing cell mechanics, locomotion, differentiation and neoplastic transformation. In order to set the scene for mechanistic discussions of the connections among alterations to subcellular structures, attendant changes in cell deformability, cytoadherence, migration, invasion and tumor metastasis, a survey is presented of the various quantitative mechanical and physical assays to extract the elastic and viscoelastic deformability of cancer cells. Results available in the literature on cell mechanics for different types of cancer are then reviewed. Representative case studies are presented next to illustrate how chemically induced cytoskeletal changes, biomechanical responses and signals from the intracellular regions act in concert with the chemomechanical environment of the extracellular matrix and the molecular tumorigenic signaling pathways to effect malignant transformations. Results are presented to illustrate how changes to cytoskeletal architecture induced by cancer drugs and chemotherapy regimens can significantly influence cell mechanics and disease state. It is reasoned through experimental evidence that greater understanding of the mechanics of cancer cell deformability and its interactions with the extracellular physical, chemical and biological environments offers enormous potential for significant new developments in disease diagnostics, prophylactics, therapeutics and drug efficacy assays.
Illustrates the steps involved in the process of micro encapsulation of PCM by In-situ polymerization. To enhance the heat transfer, Graphene nanoplatelets of 0.5, 1 and 3 wt% was added and dispersed ...homogenously by low energy ball milling process. The morphology, shape and the size of the micro capsules were characterized by SEM analysis. The shape stability of the prepared microcapsules was tested with same temperature exposure. The presence of GnP reduces the internal heat resistance by filling the voids between the microcapsules. The heat sink temperature rise rate gets delayed by the composite PCM and the rate is depend up on the GnP wt% in the PCM.
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•Paraffin is microencapsulated with polymer shell by In-situ polymerization.•Graphene nano-platelets (GnP) of 0.5, 1 and 3 wt% added to enhance the heat transfer between the encapsulated PCM.•The thermal conductance the heat sink increased with GnP wt%.•The temperature rise rate (TRR) of heat sink reduced from 1.1 °C/min to 0.85 °C/min at the temperature range of 40–60 °C.•The GnP in the encapsulated PCM reduced the recovery time of heat sink.
Encapsulation of phase change material (PCM) prevents from leakage and can evade the adverse effect of bulk volume expansion. In this study, experimental results on the heat transfer performance of graphene nano-platelets laden microencapsulated PCM (ME/GnP PCM) in a finned thermal energy storage based heat sink are presented. In-situ polymerization method was used to prepare the capsules with paraffin/polyurethane as core/shell material. The samples were characterized by its morphology, capsule size, phase change properties, thermal and chemical stability. To enhance the heat transfer within the microcapsules, GnP of 0.5, 1 and 3 wt% were incorporated. The performance of PCM was compared with a finned heat sink under constant heat load condition of 10 W, 15 W and 20 W. The performance was evaluated based on the heat sink base temperature with time for set point temperatures and the temperature rise rate (TRR). The thermal conductivity increased from 0.192 to 0.379 W/m K and the TRR of the heat sink was delayed due to the enhanced the heat transfer within the ME/GnP PCM. Moreover, the recovery time of the heat sink also declined due to reduced thermal resistance and nucleation effect in the MEPCM by the GnP.
Solar thermoelectric power generation during the day and night-time are achieved using Alumina Nano-Enhanced Phase Change Material on the Thermoelectric Generator (TEG) cold side. The portion of the ...thermal energy is used to produce electricity using TEG while the rejected heat is stored in a D-Mannitol as Phase Change Material (PCM) during active hours as thermal energy. Thus, continuous power generation is achieved using Nano-Enhanced D-Mannitol (NEDM) as the PCM. The performance parameters of TEG including voltage, current and power profile of the NEDM were recorded. The experimental setup was established for thermosyphon passive and natural convection cooling. For different mixtures, heat inputs and for both types of cooling the electrical parameters were analysed for open power output and circuit voltage. A 99% D-Mannitol + 1% Alumina nanoparticle composition was observed as the optimal composition for all heat inputs and cooling. Subjecting the optimised composition to heat inputs of 10 W, 30 W, 60 W and 90 W along with thermosyphon cooling led to increased maximum average TEG electrical power outputs of 0.23 W, 1.09 W, 1.27 W and 1.33 W respectively, each being 4.04, 4.99, 3.05 and 3.24 times higher than the corresponding values of the natural cooling phase.
•The TEG rejected thermal energy is stored and reused for reverse power generation.•The thermophysical properties of different PCM compositions are analysed.•The electrical performance of TEG incorporating thermal storage is analysed.•The optimised thermal storage composition is 1% Al2O3 + 99% D-Mannitol.•The thermosyphon cooling is 3.24 times more effective than natural cooling at 90 W.
Strengthening materials traditionally involves the controlled creation of internal defects and boundaries so as to obstruct dislocation motion. Such strategies invariably compromise ductility, the ...ability of the material to deform, stretch, or change shape permanently without breaking. Here, we outline an approach to optimize strength and ductility by identifying three essential structural characteristics for boundaries: coherency with surrounding matrix, thermal and mechanical stability, and smallest feature size finer than 100 nanometers. We assess current understanding of strengthening and propose a methodology for engineering coherent, nanoscale internal boundaries, specifically those involving nanoscale twin boundaries. Additionally, we discuss perspectives on strengthening and preserving ductility, along with potential applications for improving failure tolerance, electrical conductivity, and resistance to electromigration.
The mechanical response of materials with spatial gradients in composition and structure is of considerable interest in disciplines as diverse as tribology, geology, optoelectronics, biomechanics, ...fracture mechanics, and nanotechnology. The damage and failure resistance of surfaces to normal and sliding contact or impact can be changed substantially through such gradients. This review assesses the current understanding of the resistance of graded materials to contact deformation and damage, and outlines future research directions and possible applications for graded materials.
The objective of this work is to find the influence of fiber content, stacking pattern, and their sequence on the mechanical properties of hybrid composites. Hybrid composites in four varieties with ...five laminae containing different stacking sequences of jute/madar/glass fibers were fabricated using hand-layup technique with glass fiber woven mats as their skin layers that just enclose bio-fibers oriented horizontally. The stacking sequences were GJMJG, GMJMG, GJGJG and GMGMG where G, J, and M represents glass fiber mats, jute, and madar fibers, respectively. The fibers in the core layer were oriented perpendicular to the enclosing adjacent plies and they may be jute/madar fibers depending on the stacking sequence. Load Vs deflection curves show that stress and strain were linear and all the samples fail abruptly except the sample that contains high proportion of madar fibers. Jute fiber layers imparted more strength and energy-absorbing capacity, whilst madar fiber layers imparted more strain and toughness to the composites. Studies showed that intercalation of glass fiber mats as the core and skin layers exhibited a significant effect on the mechanical properties of the composites than other samples. The morphology of the fractured samples exhibited compatibility between matrix and reinforcements.
•An indirect type solar dryer with fans powered by solar PV panels was developed.•Drying kinetics of green chilli and okra were estimated.•Drying efficiencies were 9.15% (for green chilli) and 26.06% ...(for okra).•The effective moisture diffusivities were calculated for green chilli and okra.•Surface transfer coefficients and activation energy were estimated.
In the present work, an indirect type solar dryer (ITSD) was developed and its air flow was encouraged by inlet fans that operated by solar photovoltaic (PV) panels. Drying experiments were performed with green chilli (Capsicum Annum) and okra (Abelmoschus Esculentus). The drying kinetics and the performance parameters of ITSD were estimated. Green chilli and okra were reduced to final moisture content (MC) of 0.01001 and 0.12675 kg/kg of dry basis (db) from an initial MC of 8.3984 and 10.1234 kg/kg of db, respectively. The solar air collector efficiency and drying efficiency of 74.13, 9.15% and 78.30, 26.06%, respectively, were achieved during the drying of green chilli and okra. The average effective diffusion coefficient (De) was 1.8903 × 10−9 m2/s and 6.0073 × 10−9 m2/s during drying of green chilli and okra, respectively. The average mass transfer coefficient (hm) and heat transfer coefficient (h) were 4.406 × 10−3 m/s, 5.075 W/m2K and 3.302 × 10−3 m/s, 3.804 W/m2K for green chilli and okra, respectively. The activation energy (Ē) for green chilli and okra was 24.135 and 21.523 kJ/mol, respectively. Significant improvement is noticed in the system when it is compared with the natural convection system. Uncertainty analysis was performed.
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