scholarly journals Production and Characterization of Cross-Linked Aggregates of Geobacillus thermoleovorans CCR11 Thermoalkaliphilic Recombinant Lipase

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7569
Author(s):  
Rosa-María Oliart-Ros ◽  
Giselle-Lilian Badillo-Zeferino ◽  
Rodolfo Quintana-Castro ◽  
Irving-Israel Ruíz-López ◽  
Alfonso Alexander-Aguilera ◽  
...  
Keyword(s):  
Low Cost ◽  
Uniform Design ◽  
Geobacillus Thermoleovorans ◽  
Immobilization Of Enzymes ◽  
Alkaline Conditions ◽  
Biotechnological Processes ◽  
The Cross ◽  
Solvent Tolerant ◽  
Individual Particles

Immobilization of enzymes has many advantages for their application in biotechnological processes. In particular, the cross-linked enzyme aggregates (CLEAs) allow the production of solid biocatalysts with a high enzymatic loading and the advantage of obtaining derivatives with high stability at low cost. The purpose of this study was to produce cross-linked enzymatic aggregates (CLEAs) of LipMatCCR11, a 43 kDa recombinant solvent-tolerant thermoalkaliphilic lipase from Geobacillus thermoleovorans CCR11. LipMatCCR11-CLEAs were prepared using (NH4)2SO4 (40% w/v) as precipitant agent and glutaraldehyde (40 mM) as cross-linker, at pH 9, 20 °C. A U10(56) uniform design was used to optimize CLEA production, varying protein concentration, ammonium sulfate %, pH, glutaraldehyde concentration, temperature, and incubation time. The synthesized CLEAs were also analyzed using scanning electron microscopy (SEM) that showed individual particles of <1 µm grouped to form a superstructure. The cross-linked aggregates showed a maximum mass activity of 7750 U/g at 40 °C and pH 8 and retained more than 20% activity at 100 °C. Greater thermostability, resistance to alkaline conditions and the presence of organic solvents, and better durability during storage were observed for LipMatCCR11-CLEAs in comparison with the soluble enzyme. LipMatCCR11-CLEAs presented good reusability by conserving 40% of their initial activity after 9 cycles of reuse.

scholarly journals Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

2021 ◽  
Vol 13 (15) ◽  
pp. 8421
Author(s):  
Yuan Gao ◽  
Jiandong Huang ◽  
Meng Li ◽  
Zhongran Dai ◽  
Rongli Jiang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Efficiency ◽  
Low Cost ◽  
Chemical Activation ◽  
Cost Effective ◽  
Coal Gangue ◽  
Order Kinetic ◽  
Practical Applications ◽  
Detailed Structural Analysis ◽  
Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

Association between the FINDRISC score and the risk of metabolic syndrome and hepatic steatosis

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Godoi Bernardes Da Silva ◽  
R Dias Santos ◽  
M Sommer Bittencourt ◽  
J.A.M Carvalho ◽  
M Franken ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Hepatic Steatosis ◽  
Longitudinal Analysis ◽  
Metabolic Diseases ◽  
Low Cost ◽  
Cross Sectional ◽  
Predictive Values ◽  
Cross Sectional Analysis ◽  
The Cross ◽  
Sectional Analysis

Abstract Introduction The Finnish Diabetes Risk Score (FINDRISC) was developed in Europe to predict type 2 diabetes mellitus (T2DM) risk without need of laboratory tests. Small cross-sectional studies analyzed the association between RF with metabolic syndrome (MS) or hepatic steatosis (HS). Our objective was to test the association of FINDRISC with MS or HS, in a transversal and longitudinal way. Methods In 41,668 individuals (age 41.9±9.7 years; 30.8% women) who underwent health evaluation between 2008 and 2016 in a single centre in Brazil, we tested the transversal association between FINDRISC and MS or HS, in multivariate models. The same analyzes were performed longitudinally in non-diabetic subgroups, followed for 5±3 years, to test the predictive value of FINDRISC and the incidental risk of MS (n=10,075 individuals) or HS (n=7,097 individuals), using logistic regression. Models were adjusted for confounders such as sex, use of medications for dyslipidemia, smoking, and baseline plasma levels of glucose, creatinine and lipids. A receiver operating characteristic (ROC) curve was used to evaluate the discriminative and predictive values of FINDRISC for MS and HS. Results In the cross-sectional analysis, 2,252 (5%) individuals had MS and 14,176 (34%) HS. In the longitudinal analysis, there were 302 cases of incidental MS (2%) and 1,096 cases of HS (15%). FINDRISC was independently associated with MS and HS in the cross-sectional analysis (respectively, OR 1.27, 95% CI: 1.25–1.28, P&lt;0.001; and OR 1.21, 95% CI: 1.20–1.22, P&lt;0.001, per FINDRISC unit) and in longitudinal analysis (respectively, OR of 1.18, 95% CI: 1.15–1.21, P&lt;0.001; and OR of 1.10, 95% CI: 1.08–1.11, P&lt;0.001, per FINDRISC unit). In comparison with individuals with low FINDRISC, those with moderate, high and very high values showed significant and proportional increases of the 12 to 77 fold in the chance of current SM (P&lt;0.001) and 3 to 10 fold in the chance of HS (P&lt;0.001). During follow-up, these increases were 3 to 10 fold in the chance of incidental MS (P&lt;0.001) and 1 to 3 fold in the chance of HS (P&lt;0.001). The AUC from cross-sectional analysis for MS and HS were respectively 0.82 (95% CI 0.81–0.83) and 0.76 (95% CI 0.75–0.76), and in longitudinal analysis 0.73 (95% CI 0.70–0.76) and 0.63 (95% CI 0.61–0.65), respectively. Conclusion FINDRISC was associated with the presence and onset of MS and HS, but it predicted better metabolic syndrome risk than hepatic steatosis. Therefore, this simple, practical and low-cost score can be useful for population screening and identification of subgroups of individuals at higher risk future metabolic diseases. Funding Acknowledgement Type of funding source: None

Chemistry of Water Collected from an Unventilated Drift, Yucca Mountain, Nevada

2006 ◽  
Vol 985 ◽  
Author(s):  
Brian D Marshall ◽  
Thomas A. Oliver ◽  
Zell E. Peterman
Keyword(s):  
Pore Water ◽  
Water Samples ◽  
Conveyor Belt ◽  
Yucca Mountain ◽  
Seepage Water ◽  
Biologic Activity ◽  
Co2 Concentrations ◽  
The Cross ◽  
Chemical Conditions

AbstractWater samples (referred to as puddle water samples) were collected from the surfaces of a conveyor belt and plastic sheeting in the unventilated portion of the Enhanced Characterization of the Repository Block (ECRB) Cross Drift in 2003 and 2005 at Yucca Mountain, Nevada. The chemistry of these puddle water samples is very different than that of pore water samples from borehole cores in the same region of the Cross Drift or than seepage water samples collected from the Exploratory Studies Facility tunnel in 2005. The origin of the puddle water is condensation on surfaces of introduced materials and its chemistry is dominated by components of the introduced materials. Large CO2 concentrations may be indicative of localized chemical conditions induced by biologic activity.

scholarly journals Crystalline shielding mitigates structural rearrangement and localizes memory in jammed systems under oscillatory shear

2021 ◽  
Vol 7 (20) ◽  
pp. eabe3392
Author(s):  
Erin G. Teich ◽  
K. Lawrence Galloway ◽  
Paulo E. Arratia ◽  
Danielle S. Bassett
Keyword(s):  
Local Structure ◽  
Disordered Systems ◽  
Amorphous Materials ◽  
Structural Rearrangement ◽  
Oscillatory Shear ◽  
Disordered Materials ◽  
Rheological Measurements ◽  
Particle Level ◽  
Individual Particles

The nature of yield in amorphous materials under stress has yet to be fully elucidated. In particular, understanding how microscopic rearrangement gives rise to macroscopic structural and rheological signatures in disordered systems is vital for the prediction and characterization of yield and the study of how memory is stored in disordered materials. Here, we investigate the evolution of local structural homogeneity on an individual particle level in amorphous jammed two-dimensional (athermal) systems under oscillatory shear and relate this evolution to rearrangement, memory, and macroscale rheological measurements. We define the structural metric crystalline shielding, and show that it is predictive of rearrangement propensity and structural volatility of individual particles under shear. We use this metric to identify localized regions of the system in which the material’s memory of its preparation is preserved. Our results contribute to a growing understanding of how local structure relates to dynamic response and memory in disordered systems.

scholarly journals Theoretical and Empirical Characterization of Water as a Factor: Examples and Related Issues with the World Trade Model

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 459
Author(s):  
Ignacio Cazcarro ◽  
Albert E. Steenge
Keyword(s):  
World Trade ◽  
Low Cost ◽  
Virtual Water ◽  
Considerable Change ◽  
Water Research ◽  
Trade Model ◽  
The World ◽  
Main Model ◽  
Selection Of

This article originates from the theoretical and empirical characterization of factors in the World Trade Model (WTM). It first illustrates the usefulness of this type of model for water research to address policy questions related to virtual water trade, water constraints and water scarcity. It also illustrates the importance of certain key decisions regarding the heterogeneity of water and its relation to the technologies being employed and the prices obtained. With regard to WTM, the global economic input–output model in which multiple technologies can produce a “homogeneous output”, it was recently shown that two different mechanisms should be distinguished by which multiple technologies can arise, i.e., from “technology-specific” or from “shared” factors, which implies a mechanism-specific set of prices, quantities and rents. We discuss and extend these characterizations, notably in relation to the real-world characterization of water as a factor (for which we use the terms technology specific, fully shared and “mixed”). We propose that the presence of these separate mechanisms results in the models being sensitive to relatively small variations in specific numerical values. To address this sensitivity, we suggest a specific role for specific (sub)models or key choices to counter unrealistic model outcomes. To support our proposal we present a selection of simulations for aggregated world regions, and show how key results concerning quantities, prices and rents can be subject to considerable change depending on the precise definitions of resource endowments and the technology-specificity of the factors. For instance, depending on the adopted water heterogeneity level, outcomes can vary from relatively low-cost solutions to higher cost ones and can even reach infeasibility. In the main model discussed here (WTM) factor prices are exogenous, which also contributes to the overall numerical sensitivity of the model. All this affects to a large extent our interpretation of the water challenges, which preferably need to be assessed in integrated frameworks, to account for the main socioeconomic variables, technologies and resources.

scholarly journals Synthesis and Theoretical Investigation Using DFT of 2,3-Diphenylquinoxaline Derivatives for Electronic and Photovoltaic Effects

2021 ◽  
Author(s):  
Dorota Zając ◽  
Dariusz Przybylski ◽  
Jadwiga Sołoducho
Keyword(s):  
Solar Cells ◽  
Acrylic Acid ◽  
Organic Semiconductors ◽  
Organic Solar Cells ◽  
Molecular Design ◽  
Low Cost ◽  
Design Synthesis ◽  
Semiconducting Properties ◽  
Homo Lumo

AbstractDeveloping effective and low‐cost organic semiconductors is an opportunity for the development of organic solar cells (OPV). Herein, we report the molecular design, synthesis and characterization of two molecules with D–A–D–A configuration: 2-cyano-3-(5-(8-(3,4-ethylenodioxythiophen-5-yl)-2,3-diphenylquinoxalin-5-yl)thiophen-2-yl)acrylic acid (6) and 2-cyano-3-(5-(2,3-diphenyl-8-(thiophen-2-yl)quinoxalin-5-yl)thiophen-2-yl)acrylic acid (7). Moreover, we investigated the structural, theoretical and optical properties. The distribution of HOMO/LUMO orbitals and the values of the ionization potential indicate good semiconducting properties of the compounds and that they can be a bipolar material. Also, the optical study show good absorption in visible light (λabs 380–550 nm). We investigate the theoretical optoelectronic properties of obtained compounds as potential materials for solar cells.

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