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Open AccessCommunication
Is Root Catalase a Bifunctional Catalase-Peroxidase?
Antioxidants 2017, 6(2), 39; doi:10.3390/antiox6020039 (registering DOI) -
Abstract
Plant catalases exhibit spatial and temporal distribution of their activity. Moreover, except from the typical monofunctional catalase, a bifunctional catalase-peroxidase has been reported. The aim of this study was to investigate whether the leaf and root catalases from six different plant species (
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Plant catalases exhibit spatial and temporal distribution of their activity. Moreover, except from the typical monofunctional catalase, a bifunctional catalase-peroxidase has been reported. The aim of this study was to investigate whether the leaf and root catalases from six different plant species (Lactuca sativa, Cichorium endivia, Apium graveolens, Petroselinum crispum, Lycopersicon esculentum, and Solanum melongena) correspond to the monofunctional or the bifunctional type based on their sensitivity to the inhibitor 3-amino-1,2,4-triazole (3-AT). The leaf catalases from all species seem to be monofunctional since they are very sensitive to 3-AT. On the other hand, the root enzymes from Lactuca sativa, Cichorium endivia, Lycopersicon esculentum, and Solanum melongena seem to be bifunctional catalase-peroxidases, considering that they are relatively insensitive to 3-AT, whereas the catalases from Apium graveolens and Petroselinum crispum display the same monofunctional characteristics as the leaves’ enzymes. The leaf catalase activity is usually higher (Lactuca sativa, Petroselinum crispum, and Solanum melongena) or similar (Cichorium endivia and Apium graveolens) to the root one, except for the enzyme from Lycopersicon esculentum, while in all plant species the leaf protein concentration is significantly higher than the root protein concentration. These results suggest that there are differences between leaf and root catalases—differences that may correspond to their physiological role. Full article
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Open AccessArticle
Study of Surface Metallization of Polyimide Film and Interfacial Characterization
Metals 2017, 7(6), 189; doi:10.3390/met7060189 (registering DOI) -
Abstract
Nickel (Ni) metallization of polyimide (PI) was performed using a solution-based process including imide-ring opening reactions, the implanting of Ni ions, the reduction of catalytic Ni nanoparticles, and the electroless deposition of a Ni film. The start-up imide-ring opening reaction plays a crucial
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Nickel (Ni) metallization of polyimide (PI) was performed using a solution-based process including imide-ring opening reactions, the implanting of Ni ions, the reduction of catalytic Ni nanoparticles, and the electroless deposition of a Ni film. The start-up imide-ring opening reaction plays a crucial role in activating inert PI for subsequent Ni implanting and deposition. A basic treatment of potassium hydroxide (KOH) is commonly used in the imide-ring opening reaction where a poly(amic acid) (PAA) layer forms on the PI surface. In this study, we report that the KOH concentration significantly affects the implanting, reduction, and deposition behavior of Ni. A uniform Ni layer can be grown on a PI film with full coverage through electroless deposition with a KOH concentration of 0.5 M and higher. However, excessive imide-ring opening reactions caused by 5 M KOH treatment resulted in the formation of a thick PAA layer embedded with an uneven distribution of Ni nanoparticles. This composite layer (PAA + Ni) causes wastage of the Ni catalyst and degradation of peel strength of the Ni layer on PI. Full article
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Open AccessArticle
Impact of Vibration on the Surface Film of Lithium-Ion Cells
Energies 2017, 10(6), 741; doi:10.3390/en10060741 (registering DOI) -
Abstract
Cylindrical 18650-type lithium-ion cells are being utilized more often for automotive applications. This introduces error in calculating expected lifetime due to varied usage conditions accelerating or reducing material damage. One such usage condition is vibration, which has been shown to impact the electrical
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Cylindrical 18650-type lithium-ion cells are being utilized more often for automotive applications. This introduces error in calculating expected lifetime due to varied usage conditions accelerating or reducing material damage. One such usage condition is vibration, which has been shown to impact the electrical performance over extended periods. Within this study X-ray photoelectron spectroscopy (XPS) has been performed on nickel manganese cobalt (NMC) cells subjected to vibration. This study found that vibration causes the removal of the selectively-formed surface film created during a cell’s first cycles and replaces it with the surface film from electrolyte decomposition. The surface films formed by vibration are composed of much higher concentrations of organic electrolyte decomposition products than the film from the control cell. The impact of this chemical mechanism is an increased level of cell degradation. This is exhibited in increased capacity fade and cell impedance. This is the first study presented within the academic literature which has identified an electro-mechanical mechanism responsible for the performance degradation in lithium-ion cells from vibration. Full article
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Open AccessReview
Product Selectivity in Homogeneous Artificial Photosynthesis Using [(bpy)Rh(Cp*)X]n+-Based Catalysts
Inorganics 2017, 5(2), 35; doi:10.3390/inorganics5020035 (registering DOI) -
Abstract
Due to the limited amount of fossil energy carriers, the storage of solar energy in chemical bonds using artificial photosynthesis has been under intensive investigation within the last decades. As the understanding of the underlying working principle of these complex systems continuously grows,
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Due to the limited amount of fossil energy carriers, the storage of solar energy in chemical bonds using artificial photosynthesis has been under intensive investigation within the last decades. As the understanding of the underlying working principle of these complex systems continuously grows, more focus will be placed on a catalyst design for highly selective product formation. Recent reports have shown that multifunctional photocatalysts can operate with high chemoselectivity, forming different catalysis products under appropriate reaction conditions. Within this context [(bpy)Rh(Cp*)X]n+-based catalysts are highly relevant examples for a detailed understanding of product selectivity in artificial photosynthesis since the identification of a number of possible reaction intermediates has already been achieved. Full article
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Open AccessArticle
Development and Characterization of a Parallelizable Perfusion Bioreactor for 3D Cell Culture
Bioengineering 2017, 4(2), 51; doi:10.3390/bioengineering4020051 (registering DOI) -
Abstract
The three dimensional (3D) cultivation of stem cells in dynamic bioreactor systems is essential in the context of regenerative medicine. Still, there is a lack of bioreactor systems that allow the cultivation of multiple independent samples under different conditions while ensuring comprehensive control
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The three dimensional (3D) cultivation of stem cells in dynamic bioreactor systems is essential in the context of regenerative medicine. Still, there is a lack of bioreactor systems that allow the cultivation of multiple independent samples under different conditions while ensuring comprehensive control over the mechanical environment. Therefore, we developed a miniaturized, parallelizable perfusion bioreactor system with two different bioreactor chambers. Pressure sensors were also implemented to determine the permeability of biomaterials which allows us to approximate the shear stress conditions. To characterize the flow velocity and shear stress profile of a porous scaffold in both bioreactor chambers, a computational fluid dynamics analysis was performed. Furthermore, the mixing behavior was characterized by acquisition of the residence time distributions. Finally, the effects of the different flow and shear stress profiles of the bioreactor chambers on osteogenic differentiation of human mesenchymal stem cells were evaluated in a proof of concept study. In conclusion, the data from computational fluid dynamics and shear stress calculations were found to be predictable for relative comparison of the bioreactor geometries, but not for final determination of the optimal flow rate. However, we suggest that the system is beneficial for parallel dynamic cultivation of multiple samples for 3D cell culture processes. Full article
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Open AccessArticle
Optimum Subsidy to Promote Electric Boiler Investment to Accommodate Wind Power
Sustainability 2017, 9(6), 874; doi:10.3390/su9060874 (registering DOI) -
Abstract
The increasing development of combined heat and power (CHP) plants is exacerbating the wind power curtailment problem in regional power grids during the winter heating season. Electric boilers (EBs) were proposed to be employed within CHP plants to relieve this problem. However, CHP
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The increasing development of combined heat and power (CHP) plants is exacerbating the wind power curtailment problem in regional power grids during the winter heating season. Electric boilers (EBs) were proposed to be employed within CHP plants to relieve this problem. However, CHP plants usually have no incentive for investing in EBs. Therefore, CHP plants must be incentivized to make such investments through appropriate compensation from beneficiaries, i.e., government and wind farms, although this has not previously been discussed. We propose a game theory model to simulate the impact of government subsidies on EB investment. We analyzed the utilization of the involved parties with the marginal cost and average cost and applied game theory to simulate the investment decisions. Then, an approximate enumeration technique was developed to identify the optimum government subsidy. An actual case of a regional power grid in northern China was investigated to validate the proposed method. A minimum government subsidy to maximize total social benefit was calculated; this subsidy can incentivize wind farms and CHP plants to invest in and use EBs. Full article
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Open AccessArticle
Utilization of Sugarcane Bagasse by Halogeometricum borinquense Strain E3 for Biosynthesis of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
Bioengineering 2017, 4(2), 50; doi:10.3390/bioengineering4020050 (registering DOI) -
Abstract
Sugarcane bagasse (SCB), one of the major lignocellulosic agro-industrial waste products, was used as a substrate for biosynthesis of polyhydroxyalkanoates (PHA) by halophilic archaea. Among the various wild-type halophilic archaeal strains screened, Halogeometricum borinquense strain E3 showed better growth and PHA accumulation as
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Sugarcane bagasse (SCB), one of the major lignocellulosic agro-industrial waste products, was used as a substrate for biosynthesis of polyhydroxyalkanoates (PHA) by halophilic archaea. Among the various wild-type halophilic archaeal strains screened, Halogeometricum borinquense strain E3 showed better growth and PHA accumulation as compared to Haloferaxvolcanii strain BBK2, Haloarcula japonica strain BS2, and Halococcus salifodinae strain BK6. Growth kinetics and bioprocess parameters revealed the maximum PHA accumulated by strain E3 to be 50.4 ± 0.1 and 45.7 ± 0.19 (%) with specific productivity (qp) of 3.0 and 2.7 (mg/g/h) using NaCl synthetic medium supplemented with 25% and 50% SCB hydrolysate, respectively. PHAs synthesized by strain E3 were recovered in chloroform using a Soxhlet apparatus. Characterization of the polymer using crotonic acid assay, X-ray diffraction (XRD), differential scanning calorimeter (DSC), Fourier transform infrared (FT-IR), and proton nuclear magnetic resonance (1H-NMR) spectroscopy analysis revealed the polymer obtained from SCB hydrolysate to be a co-polymer of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] comprising of 13.29 mol % 3HV units. Full article
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Open AccessArticle
Selected Risk Nutritional Factors for Chemotherapy-Induced Polyneuropathy
Nutrients 2017, 9(6), 535; doi:10.3390/nu9060535 (registering DOI) -
Abstract
The present study seeks to identify the nutritional risk factors involved in the development of neuropathies induced by chemotherapeutic treatments. Unlike the gastrointestinal or hematological adverse effects of chemotherapy there is no protective treatment strategy for polyneuropathy. The aim of this study was
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The present study seeks to identify the nutritional risk factors involved in the development of neuropathies induced by chemotherapeutic treatments. Unlike the gastrointestinal or hematological adverse effects of chemotherapy there is no protective treatment strategy for polyneuropathy. The aim of this study was to find possible deficiencies in nutritional factors, which can be used for supplementation in the future for prevention of chemotherapy-induced neuropathy development. We analyzed 70 patients undergoing paclitaxel chemotherapy and evaluated the risk factors involved in chemotherapy-induced peripheral neuropathy (CIPN). Several risk factors were considered in the development of CIPN, including deficiency of vitamin B1, B6, and D and fatty acids. The occurrence of CIPN complication in 60% cases was observed. We found significant differences in vitamin D and saturated fatty acid concentration. Vitamin D levels in the group without CIPN were estimated to be 38.2 (24.95, 47.63) nmol/L, whereas in the group with CIPN it was determined to be 25.6 (19.7, 32.55) nmol/L, p = 0.008. The level of total saturated fatty acids in the group without CIPN was of 32.613 Area % (31.322; 36.262), whereas in the group with CIPN it was of 34.209 Area % (32.86; 39.386), p = 0.01. The obtained results suggest a diet lower in saturated fatty acid content during chemotherapy. The most significant finding was that supplementation of vitamin D before chemotherapy could be an efficient neuroprotective in CIPN prophylaxis, as significantly lower levels 25OH derivative of vitamin D were observed in the CIPN group throughout the study period. Full article
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Open AccessBrief Report
Effects of Osteopathic Treatment on Postural Equilibrium Evaluated through a Stabilometric Platform: A Randomized and Controlled Study
J. Funct. Morphol. Kinesiol. 2017, 2(2), 18; doi:10.3390/jfmk2020018 -
Abstract
Equilibrium is a very complex function and involves many systems, including the somatic-sensory, vestibular and visual systems. The condition of balance is maintained until the gravity center falls into the perimeter of support, defined as the ground level of the support base. Equilibrium
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Equilibrium is a very complex function and involves many systems, including the somatic-sensory, vestibular and visual systems. The condition of balance is maintained until the gravity center falls into the perimeter of support, defined as the ground level of the support base. Equilibrium loss is at the root of the risk of falling down, and represents a public health issue associated with remarkable costs for hospitalization, risk of residual disability and death for the elderly. Osteopathy can be a good ally that allows the human body to oppose gravitational force in a functional and ergonomic way. Osteopathy represents a medical approach complementary to healthcare and could be a non-invasive approach to improve and support traditional medicine in different physiological and pathological conditions. The aim of this study is to evaluate the cause-effect relationship between Manipulative Osteopathic Treatment (OMT) and its effects on equilibrium through stabilometric examinations. The 63 chosen subjects, including 23 females and 40 males, were between 18 and 45 years old, with a mean age of 29. Subjects were randomly divided into two groups: Manipulative Osteopathic Treatment (OMT) and Non Touch group (NON TOUCH). We can confirm that the tonic-postural response was more marked in the OMT group, with a statistic relevance both for the ellipse surface and the tangle length, with better stability and consequent energy saving in treated subjects. There were not statistically relevant variations for the NON TOUCH group. Therefore, it seems that Manipulative Osteopathic Treatment (OMT) influences stabilometry. However, posture influence due to Manipulative Osteopathic Treatment (OMT) should be evaluated with short- and long-term follow-ups, and with a larger sample size to test the administration of osteopathic treatments, in order to define an adequate work plan time period to prevent equilibrium loss. Full article
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