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Koefoed Hemmingsen
Koefoed Hemmingsen

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An All-Hydrophobic Water Diode with regard to Continuous and Reduced-Wastage Water Carry.

Due to their unique properties, paper-based biosensors have attracted attention as inexpensive devices for on-site analysis. To achieve fast and sensitive detection of analytes, immobilization of enzymes with high apparent activities on paper is highly desirable; however, this is challenging. Herein, we report an improved approach to attach a malathion degrading enzyme, PoOPHM9, on paper via an interlocking network of Pluronic F127 (PF127)-poly(acrylic acid)-enzyme conjugates. The addition of PF127 improved retention of enzymatic activity as the apparent kinetic constant Vmax of the immobilized enzyme increased two-fold compared with the paper prepared without PF127. The PF127-poly(acrylic acid)-PoOPHM9 papers provided rapid colorimetric detection of malathion at 0.1-50 mM. The detection was completed within 5 min using a smartphone and image analysis software. As a proof-of-concept, malathion-contaminated water, plant, and apple samples were analyzed with the papers successfully. This material is promising for on-site rapid analysis of malathion-contaminated samples.The probiotic strain of Bacillus subtilis presents a promising application potential for the value-added bio-utilization of lignocellulosic carbohydrates. By the combined acidolysis pretreatment and enzymatic hydrolysis, hemicellulose and cellulose constituents of corncob were efficiently converted respectively into fermentable C5 and C6 sugars, mainly including xylose and glucose. B. subtilis grew well in xylose solution while it was hindered completely in the acidolysis broth because of the bio-toxicity of degraded chemicals derived from corncob. A mixed-fermentation technique was therefore developed and performed to blend the acidolysis broth and enzymatic hydrolysis slurry together, by which C5 and C6 sugar molecules were successfully fermented and efficiently utilized for the growth of B. subtilis cells with a yield of 0.33 g cells/g sugar consumed. A net amount of 205.9 ± 9.0 g of B. subtilis powder was obtained from 1000 g of corncob that could improve the economic benefits of the process to around 5-7 times.Amino-modified mesoporous silica (SBA-15-NH2) was prepared by hydrothermal method, which is a kind of excellent carrier for enzyme immobilization. The structure of SBA-15 was characterized by SEM and FTIR, which proved that amino group was successfully attached to the surface of SBA-15. The carrier had good mesoporous structure proved by nitrogen adsorption and desorption test. MK-4827 mouse Using SBA-15-NH2 as the carrier, the optimal conditions of laccase immobilization by two different cross-linking methods were explored. At the same time, the properties of the immobilized enzyme and free enzyme were compared. The results showed that the activity of immobilized laccase by two-step method (2977.5 U/g) was much higher than that by one-step method (239.5 U/g). The optimal conditions were as follows free laccase (35°C, pH=4.5), two-step immobilized laccase (40°C, pH=4.0), one-step immobilized laccase (35°C, pH=4.0). The two-step method was more adaptable to temperature. The pH adaptation range of the immobilized enzyme is wider, and the thermal stability is greatly enhanced. After five cycles of repeated reaction, the residual enzyme activity of two-step and one-step methods was 56% and 43% of the original. The treatment of simulated wastewater containing 2,4-dichlorophenol (2,4-DCP) by immobilized laccase was also studied. Under optimum conditions (40°C, pH=5.0, 20 mg/L), the removal of 2,4-DCP reached 89.06%. The immobilized laccase is really effective for treatment of 2,4-DCP-containing wastewater.Indole acetic acid (IAA) has been an important compound for plant growth and is widely known to be produced by plant growth-promoting rhizobacteria (PGPR). The isolate producing the maximum amount of IAA from the Korea shooting range soil was identified as Pseudarthrobacter sp. NIBRBAC000502770, using 16S rRNA gene sequencing. IAA production was determined in Luria-Bertani (LB) broth and optimized using different temperatures, agitation rates, L-tryptophan concentrations, carbon and nitrogen sources, and inorganic salts. The strain NIBRBAC000502770 showed better production of IAA at temperature 30 °C (29.47 mg·L-1) and at an agitation rate of 200 rpm (32.65 mg·L-1). Maltose (0.5%) was found to be the best carbon source for the strain (yielding 36.48 mg·L-1 IAA). IAA yield was 19.17 mg·L-1 and 24.73 mg·L-1 at 1% yeast extract and 1% tryptone as nitrogen sources, respectively. qRT-PCR showed the transcript levels of amiE and aldH genes, which had been predicted to encode indole-3-acetamide hydrolase and indole-3-acetaldehyde dehydrogenase, to be significantly upregulated in response to tryptophan. This study has examined that NIBRBAC000502770 has significant effects as a biological agent such as plant growth promotion, and development of optimal medium could significantly reduce the cost of mass production of microorganisms.The dielectric properties of bones are found to be influenced by the demineralisation of bones. Therefore, microwave imaging (MWI) can be used to monitor in vivo dielectric properties of human bones and hence aid in the monitoring of osteoporosis. This paper presents the feasibility analysis of the MWI device for monitoring osteoporosis. Firstly, the dielectric properties of tissues present in the human heel are analysed. Secondly, a transmission line (TL) formalism approach is adopted to examine the feasible frequency band and the matching medium for MWI of trabecular bone. Finally, simplified numerical modelling of the human heel was set to monitor the penetration of E-field, the received signal strength, and the power loss in a numerical model of the human heel. Based on the TL formalism approach, 0.6-1.9-GHz frequency band is found to feasible for bone imaging purpose. The relative permittivity of the matching medium can be chosen between 15 and 40. The average percentage difference between the received signal for feasible and inconvenient frequency band was found to be 82%. The findings based on the dielectric contrast of tissues in the heel, the feasible frequency band, and the finite difference time domain simulations support the development of an MWI prototype for monitoring osteoporosis.MK-4827 mouse

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