Current Issue : October - December Volume : 2018 Issue Number : 4 Articles : 5 Articles
Background: The recalcitrance of lignocellulosic biomass offers a series of challenges for biochemical processing\ninto biofuels and bio-products. For the first time, we address these challenges with a biomimetic system via a mild\nyet rapid Fenton reaction and lignocellulose-degrading bacterial strain Cupriavidus basilensis B-8 (here after B-8) to\npretreat the rice straw (RS) by mimicking the natural fungal invasion process. Here, we also elaborated the mechanism\nthrough conducting a systematic study of physicochemical changes before and after pretreatment.\nResults: After synergistic Fenton and B-8 pretreatment, the reducing sugar yield was increased by 15.6ââ?¬â??56.6%\nover Fenton pretreatment alone and 2.7ââ?¬â??5.2 times over untreated RS (98 mg gâË?â??1). Morphological analysis revealed\nthat pretreatment changed the surface morphology of the RS, and the increase in roughness and hydrophilic sites\nenhanced lignocellulose bioavailability. Chemical components analyses showed that B-8 removed part of the lignin\nand hemicellulose which caused the cellulose content to increase. In addition, the important chemical modifications\nalso occurred in lignin, 2D NMR analysis of the lignin in residues indicated that the Fenton pretreatment caused partial\ndepolymerization of lignin mainly by cleaving the Ã?²-O-4 linkages and by demethoxylation to remove the syringyl (S)\nand guaiacyl (G) units. B-8 could depolymerize amount of the G units by cleaving the Ã?²-5 linkages that interconnect\nthe lignin subunits.\nConclusions: A biomimetic system with a biochemical Fenton reaction and lignocellulose-degrading bacteria was\nconfirmed to be able for the pretreatment of RS to enhance enzymatic hydrolysis under mild conditions. The high\ndigestibility was attributed to the destruction of the lignin structure, partial hydrolysis of the hemicellulose and partial\nsurface oxidation of the cellulose. The mechanism of synergistic Fenton and B-8 pretreatment was also explored to\nunderstand the change in the RS and the bacterial effects on enzymatic hydrolysis. Furthermore, this biomimetic\nsystem offers new insights into the pretreatment of lignocellulosic biomass....
Background: Noise exposure can lead to hearing loss and multiple system dysfunctions. As various forms of noise\nexist in our living environments, and our auditory organs are very sensitive to acoustic stimuli, it is a challenge to\nprotect our hearing system in certain noisy environments.\nPresentation of the hypothesis: Herein, we propose that our hearing organ could serve as a noise eliminator for\nhigh intensity noise and enhance acoustic signal processing abilities by increasing the signal-noise ratio. For\nsuprathreshold signals, the hearing system is capable of regulating the middle ear muscles and other structures to\nactively suppress the sound level to a safe range.\nTesting the hypothesis: To test our hypothesis, both mathematic model analyses and animal model studies\nare needed. Based on a digital 3D reconstructed model, every structure in the auditory system can be\nanalyzed and tested for its contribution to the process of noise reduction. Products manufactured by this\nbionic method could be used and verified in animal models and volunteers.\nImplications: By mimicking the noise-reduction effect of the sophisticated structures in the hearing system,\nwe may be able to provide a model that establishes a new active-sound-suppression mode. This innovative\nmethod may overcome the limited capabilities of current noise protection options and become a promising\npossibility for noise prevention....
We first discuss cement production and special nomenclature used by cement industrialists in expressing the composition of their\ncement products. We reveal different types of cement products, their compositions, properties, and typical uses. Wherever\npossible, we tend to give reasons as to why a particular cement type is more suitable for a given purpose than other types. Cement\nmanufacturing processes are associated with emissions of large quantities of greenhouse gases and environmental pollutants. We\ngive below quantitative and qualitative analyses of environmental impact of cement manufacturing. Controlling pollution is\na mandatory legal and social requirement pertinent to any industry. As cement industry is one of the biggest CO2 emitters, it is\nappropriate to discuss different ways and means of CO2 capture, which will be done next. Finally, we give an account of production\nof nanocement and advantages associated with nanocement. Nanofillers such as nanotitania, nanosilica, and nanoalumina can be\nproduced in large industrial scale via top-down approach of reducing size of naturally available bulk raw materials to those in the\nnanorange of 1 nmââ?¬â??100 nm. We mention the preparation of nanotitania and nanosilica from Sri Lankan mineral sands and quartz\ndeposits, respectively, for the use as additives in cement products to improve performance and reduce the amount and cost of\ncement production and consequent environmental impacts. As of now, mineral sands and other treasures of minerals are exported\nwithout much value addition. Simple chemical modifications or physical treatments would add enormous value to these natural\nmaterials. Sri Lanka is gifted with highly pure quartz and graphite from which silica and graphite nanoparticles, respectively, can\nbe prepared by simple size reduction processes. These can be used as additives in cements. Separation of constituents of mineral\nsands is already an ongoing process....
Background: Powered exoskeleton can improve the mobility for people with movement deficits by providing\nmechanical support and facilitate the gait training. This pilot study evaluated the effect of gait training using a\nnewly developed powered lower limb exoskeleton robot for individuals with complete spinal cord injury (SCI).\nMethods: Two participants with a complete SCI were recruited for this clinical study. The powered exoskeleton gait\ntraining was 8 weeks, 1 h per session, and 2 sessions per week. The evaluation was performed before and after the\ntraining for (1) the time taken by the user to don and doff the powered exoskeleton independently, (2) the level of\nexertion perceived by participants while using the powered exoskeleton, and (3) the mobility performance included\nthe timed up-and-go test, 10-m walk test, and 6-min walk test with the powered exoskeleton. The safety of the\npowered exoskeleton was evaluated on the basis of injury reports and the incidence of falls or imbalance while\nusing the device.\nResults: The results indicated that the participants were donning and doffing the powered lower limb exoskeleton\nrobot independently with a lower level of exertion and walked faster and farther without any injury or fall incidence\nwhen using the powered exoskeleton than when using a kneeââ?¬â??ankleââ?¬â??foot orthosis. Bone mineral densities was also\nincreased after the gait training. No adverse effects, such as skin abrasions, or discomfort were reported while using\nthe powered exoskeleton.\nConclusions: The findings demonstrated that individuals with complete SCI used the powered lower limb...
With the progress of nanotechnology and molecular biology, nanoparticles have been widely studied and applied in biomedicine.\nParticularly, characterized by unique magnetic property, targeting, and biocompatibility, magnetic nanoparticles have become one\nof the research hotspots in the nanomedical field. Herein, we summarized the recent advances of magnetic nanoparticles in\nmedicine, including the property, carrier function, MRI, and tumor magnetic inductive hyperthermia of magnetic nanoparticles....
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