Structural Functional Properties Research Articles

Optimal admission control under premature discharge decisions for operational effectiveness

AbstractThe shortage of inpatient beds causes surgery cancellations, treatment delays, and inappropriate ward arrangements. That is why studying how to make admission decisions on the wards of crowded units under premature discharge decisions is essential. In this study, we set up an infinite‐horizon total discounted cost Markov decision process model to minimize the total expected cost to the hospital. By analyzing the structural properties of the optimal value function, we find that there is an optimal admission control policy of the threshold type for low‐acuity emergency patients (type‐2). Numerical experiments are done to examine how optimal dynamic policy depends on key system parameters. Furthermore, we evaluate the performance of the optimal dynamic policy with a benchmark policy without premature discharge decisions. The results indicate that the optimal admission control policy helps hospitals in maintaining low costs and enables patients with high‐acuity diseases to enter primary wards more quickly.

Enzymatic Hydrolysis of Seabuckthorn Seed Protein Concentrate by Different Proteases and Effects on Structural Properties, Functional Properties and Antioxidant Activity of Resulting Hydrolysates

Enzymatic Hydrolysis of Seabuckthorn Seed Protein Concentrate by Different Proteases and Effects on Structural Properties, Functional Properties and Antioxidant Activity of Resulting Hydrolysates

On structural properties of optimal average cost functions in Markov decision processes with Borel spaces and universally measurable policies

We consider Markov decision processes (MDPs) with Borel state and action spaces and universally measurable policies. For several long-run average cost criteria and two classes of MDPs, we prove sufficient conditions for the optimal average cost functions to be constant almost everywhere with respect to certain σ-finite measures. Besides suitable boundedness conditions on the positive parts of the one-stage costs, the key condition here is that each subset of states with positive measure be reachable with probability one under some policy. Our proofs exploit an inequality for the optimal average cost functions and its connection with submartingales, and, in a special case that involves stationary policies, also use the theory of recurrent Markov chains.

Layered Oxygen-Deficient Double Perovskites as Promising Cathode Materials for Solid Oxide Fuel Cells.

Development of new functional materials with improved characteristics for solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs) is one of the most important tasks of modern materials science. High electrocatalytic activity in oxygen reduction reactions (ORR), chemical and thermomechanical compatibility with solid electrolytes, as well as stability at elevated temperatures are the most important requirements for cathode materials utilized in SOFCs. Layered oxygen-deficient double perovskites possess the complex of the above-mentioned properties, being one of the most promising cathode materials operating at intermediate temperatures. The present review summarizes the data available in the literature concerning crystal structure, thermal, electrotransport-related, and other functional properties (including electrochemical performance in ORR) of these materials. The main emphasis is placed on the state-of-art approaches to improving the functional characteristics of these complex oxides.

Influence of mechanical and heat treatment on structure evolution and functional properties of Fe-Al-Tb alloys

The current research focuses on the microstructural analysis, damping, and magnetostrictive behavior of the Fe-12Al and Fe-21Al alloys doped with Tb after various mechanical and heat treatments. The thermomechanical treatment provides enhanced magnetostriction in both Fe-12Al and Fe-21Al with Tb addition. The maximal magnetostriction was observed in the alloys after hot rolling and subsequent 30 min annealing at 900 °C followed by air cooling. Tb increases the low temperature IF background and magnetostriction of Fe-21Al-Tb alloy.

Light-colored lignin isolated from poplar by ultrasound-assisted ethanol extraction: Structural features and anti-ultraviolet and anti-oxidation activities

Ethanol extraction of lignocellulosic biomass under mild conditions has re-attracted considerable attention since a light-colored lignin with low molecular weight can be obtained. Unfortunately, the yield of isolated lignin for the ethanol extraction process is very limited. To enhance the extraction efficiency of lignin from poplar, ultrasound was used to assist the ethanol extraction and the isolated lignin was analyzed in terms of structure features and functional properties. As expected, increasing the ultrasonic power and ultrasonic time led to higher lignin yields during the ultrasound-assisted ethanol extraction (UAEE) process. The chemical structure of the isolated lignin (UAE-L) was almost completely retained, the C-O (mainly β-O-4) linkages in the lignin only exhibited a slight decrease, while the C-C (β-β, β-5, and β-1) linkages were nearly unchanged. The UAE-L was light in color and had more phenolic hydroxyl groups, less carbohydrate impurities, lower molecular weight and narrower polydispersity as compared to the poplar MWL. The UAE-L could scavenge more 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH·), displaying a stronger antioxidant activity. Moreover, the UAE-L showed good UV-absorbing properties in both UVA and UVB regions. These results indicated that the UAE-L has great potential for replacing the commercial synthesized antioxidant and anti-UV ingredients.

Vegetable waste and by-products to feed a healthy gut microbiota: Current evidence, machine learning and computational tools to design novel microbiome-targeted foods

Food waste management is a key issue to global food security and friendly environmental governance. Worldwide, one-third of food produced for human consumption is lost or wasted along the food supply chain, primary production and food processing representing the most significant loses. Therefore, the need to achieve zero waste production schemes is becoming a priority to meet Sustainable Development Goals. Increasing evidence points towards vegetable food waste as a rich source of a wide array of carbohydrate structures and fibres providing the opportunity to identify and develop alternative approaches to valorize agro-food waste. This review describes the valorization of vegetable waste and by-products via production of (novel) substrates targeted to gut microbiota modulation, emphasizing the importance of raw materials and structural-functional properties of carbohydrates. Furthermore, we propose a novel framework for the rational selection of vegetable sources with potential prebiotic activity, based on machine learning and other computational tools applied to available literature and public database information. Integration of the body of knowledge within the field of vegetable food waste valorization, from different perspectives, allows a rational selection of carbohydrate-based substrates with promising prebiotic activities. By exploring the interactions among dietary fibre and gut microbial ecosystems using computational tools fed with structural, functional and genomic data, we can identify substrates with potential to selectively stimulate gut commensals, in agreement with experimental evidence. Our approach establishes a new framework that can be extended to a wide range of commensal microbes and carbohydrate structures.

Structure-function relationship of small peptides generated during the ripening of Spanish dry-cured ham: Peptidome, molecular stability and computational modelling

A systematic insight into the structure–function properties of small bioactive peptides is of great importance. Herein, peptidomics and computational methodology were adopted to investigate the stabilization patterns and building blocks of antioxidant peptides resulting from proteolysis during the ripening of Spanish dry-cured ham (9–24 months of processing). The results showed that native peptides underwent manufacture-induced steric/redox stress, while homogeneous/heterogeneous p-π/π-π interaction significantly improved the ABTS+ inhibition activity of hydrophobic peptides. However, for more hydrophilic peptides, the intrinsic π-interaction system (i.e., cation-π and π-π packing) substantially interfered with ABTS+/DPPH scavenging events when compared to the aromatic residues. Semi-quantitative peptidomics and molecular simulation/docking revealed that VFSSQGQSELILLQK and LCPSPDGLYL are two potential antioxidant peptides at the late ripening-drying. They had distinctive self-folding destinies following solvation owing to varying charged/hydrophobic properties of termini and hydrogen atom donor, allowing different flexibility of backbone and interactive surface towards free radicals ex situ followed by electron/proton transfer.

Relative importance of branching enzyme isoforms in determining starch fine structure and physicochemical properties of indica rice.

Down-regulation of starch branching enzymes alters fine structure and starch properties, especially the B-type crystalline pattern and extremely high amylose content identified in the BEIIb-deficiency mutant in the indica rice. The relative importance of the starch branching enzymes in determining the molecular fine structure and starch functional properties were uncovered in this study. An indica rice, Guangluai 4 with high amylose content (AC) and high gelatinization temperature (GT) was used to generate the clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein-9 (Cas9) knockout lines. Five mutant lines were identified including be1-1, be1-2, be2a-1, be2a-2 and be2b-1, and analysis of western blot showed the CRISPR/Cas9 system was successful in inducing mutations in the targeted genes. AC of be2b-1 (34.1%) was greater than that of wild type (WT) (27.4%) and other mutants. Mutations of either BEI or BEIIa did not alter the starch crystallite pattern (A-type). The BEIIb deficiency caused an opaque endosperm phenotype, changed the crystallite pattern from A- to B-type, and dramatically increased the degree of ordered structure, the relative proportion of amylose chains and intermediate to long amylopectin chains, average chain length of amylopectin molecules as well as GT. The BEIIa deficiency had no effect on the proportion of amylose chains, the length of amylopectin intermediate-long chains, conclusion temperature and enthalpy of gelatinization. Down-regulation of BEI increased the proportion of shortest amylopectin chains (fa) but decreased the proportion of long amylopectin chains (fb2 and fb3), leading to a lower GT. It is concluded that the relative importance in determining starch fine structures and functionality was in the order of BEIIb > BEI > BEIIa. Our results provide new information for utilizations of BE-deficient mutants in rice quality breeding.

Doss ρ-Almost Periodic Type Functions in Rn

In this paper, we investigate various classes of multi-dimensional Doss ρ-almost periodic type functions of the form F:Λ×X→Y, where n∈N,∅≠Λ⊆Rn, X and Y are complex Banach spaces, and ρ is a binary relation on Y. We work in the general setting of Lebesgue spaces with variable exponents. The main structural properties of multi-dimensional Doss ρ-almost periodic type functions, like the translation invariance, the convolution invariance and the invariance under the actions of convolution products, are clarified. We examine connections of Doss ρ-almost periodic type functions with (ω,c)-periodic functions and Weyl-ρ-almost periodic type functions in the multi-dimensional setting. Certain applications of our results to the abstract Volterra integro-differential equations and the partial differential equations are given.

Influence of the Graphene Filler Nature on the Morphology and Properties of Melt Blended EVOH Based Nanocomposites.

In this study, ethylene vinyl alcohol (EVOH) nanocomposites elaborated by melt blending with four different fillers were investigated. Two graphene and two graphite fillers displaying various shapes were selected. The morphology, microstructure, thermal, mechanical, and barrier properties of the nanocomposite films prepared for 2 wt% fillers were analyzed with the aim to establish structure–function properties relationships. The nanocomposites properties significantly depended on the nature of the incorporated filler. The nanocomposite film prepared with the expanded graphite filler exhibited the highest Young modulus value (E = 1430 MPa) and the best barrier properties. Indeed, barrier properties, rarely studied at high water activities, evidenced a significant improvement with a decrease of the water vapor permeability by a factor 1.8 and of the oxygen permeabilities by a factor close to 2, for a critical water activity higher than 0.95. An increase of the thermal stability was also evidenced for this nanocomposite. It was shown that for all studied nanocomposites, the properties could be related to the dispersion state of the fillers and the simultaneous increase of the crystallinity of the matrix. A specific equation was proposed to take into account these both parameters to accurately predict the nanocomposite barrier properties.

Effects of fermentation with lactic bacteria on the structural characteristics and physicochemical and functional properties of soluble dietary fiber from prosomillet bran

Prosomillet bran was fermented with lactic bacteria and the changes of the structure and physicochemical and functional properties of its soluble dietary fiber (SDF) were investigated. Results showed the yield of SDF was increased from 4.2% to 7.6% after fermentation, and the odor intensity and flavor characteristics were also significantly changed. SEM and FTIR assay indicated that the microstructure after fermentation became looser and more porous, and both of UF-SDF and F-SDF had characteristic absorption peaks of polysaccharides. Fermentation also reduced the crystalline area and thus affected the thermal stability of SDF by X-ray diffraction and thermal analysis. In addition, the physicochemical and functional properties such as solubility, water and oil holding capacity, swelling capacity, nitrite, sodium cholate and cholesterol adsorption capacity were improved as well. The phenolic content and free radical scavenging capacity also increased significantly. The above results showed that F-SDF could be applied as a functional ingredient in food industry.

Development and Functional Properties of Intestinal Mucus Layer in Poultry.

Intestinal mucus plays important roles in protecting the epithelial surfaces against pathogens, supporting the colonization with commensal bacteria, maintaining an appropriate environment for digestion, as well as facilitating nutrient transport from the lumen to the underlying epithelium. The mucus layer in the poultry gut is produced and preserved by mucin-secreting goblet cells that rapidly develop and mature after hatch as a response to external stimuli including environmental factors, intestinal microbiota as well as dietary factors. The ontogenetic development of goblet cells affects the mucin composition and secretion, causing an alteration in the physicochemical properties of the mucus layer. The intestinal mucus prevents the invasion of pathogens to the epithelium by its antibacterial properties (e.g. β-defensin, lysozyme, avidin and IgA) and creates a physical barrier with the ability to protect the epithelium from pathogens. Mucosal barrier is the first line of innate defense in the gastrointestinal tract. This barrier has a selective permeability that allows small particles and nutrients passing through. The structural components and functional properties of mucins have been reviewed extensively in humans and rodents, but it seems to be neglected in poultry. This review discusses the impact of age on development of goblet cells and their mucus production with relevance for the functional characteristics of mucus layer and its protective mechanism in the chicken’s intestine. Dietary factors directly and indirectly (through modification of the gut bacteria and their metabolic activities) affect goblet cell proliferation and differentiation and can be used to manipulate mucosal integrity and dynamic. However, the mode of action and mechanisms behind these effects need to be studied further. As mucins resist to digestion processes, the sloughed mucins can be utilized by bacteria in the lower part of the gut and are considered as endogenous loss of protein and energy to animal. Hydrothermal processing of poultry feed may reduce this loss by reduction in mucus shedding into the lumen. Given the significance of this loss and the lack of precise data, this matter needs to be carefully investigated in the future and the nutritional strategies reducing this loss have to be defined better.

Multi-UAV Trajectory and Power Optimization for Cached UAV Wireless Networks With Energy and Content Recharging-Demand Driven Deep Learning Approach

In this paper, we propose a novel joint trajectory and communication scheduling scheme for multiple unmanned aerial vehicles (UAVs) enabled wireless caching networks. To exploit the favorable propagation of air-to-ground channels, we consider an ultra dense UAVs enabled content-centric wireless transmission network, where massive UAVs are deployed to transmit cached contents to a group of random distributed ground users. We formulate the problem as an infinite horizon ergodic stochastic differential game (SDG) for optimizing the users' quality-of-experience (QoE). In particular, stochastic dynamics of channel states, UAVs' mobility, energy queues and content request queues are modeled in this game. To deal with the state coupling between the UAVs, we consider a limiting problem for large number of UAV based on mean field analysis. A reduced-complexity decentralized solution can be obtained through mean-field equilibrium analysis. To further reduce the solution complexity on each UAV, we propose a model-specific deep neural network (DNN) to learn the optimal control solution in an online manner. The DNN is not arbitrarily generated but tailored to the structural properties of the value function and stationary distribution based on the homotopy perturbation method analysis. Finally, simulation results are provided to show that the proposed solution can achieve significant gain over the existing baselines.

Modification of functional properties of perilla protein isolate by high-intensity ultrasonic treatment and the stability of o/w emulsion

This study investigated the effects of ultrasonic treatment on the structural characteristics and functional properties of perilla protein isolate (PPI). Besides, the performance of the emulsions stabilized by ultrasonic-treated PPI was analyzed, aiming at exploring the potential mechanism of ultrasonic technology to improve emulsion stability. Results showed that ultrasonic treatment reduced the particle size, induced the exposure of hydrophobic groups and changes in the secondary structure and tertiary conformation of PPI. However, the molecular weight and the crystalline regions were remained unchanged. Apart from this, ultrasonic treatment improved the solubility, water/oil holding capacity, foaming and emulsifying capacity of PPI. Furthermore, the emulsions prepared by ultrasonic-treated PPI possessed the highest stability, which might be due to the smaller droplets size and reduced droplets attraction by higher proportion of interfacial adsorbed protein. This findings will provide a new insight into the application of ultrasonic to improve the stability of PPI-stabilized emulsions.

Structural model and functional properties of an exo-polygalacturonase from Neosartorya glabra

A purified exo-polygalacturonase of Neosartorya glabra (EplNg) was successfully characterized. EplNg native presented 68.2 kDa, with 32% carbohydrate content. The deglycosylated form showed 46.3 kDa and isoelectric point of 5.4. The identity of EplNg was confirmed as an exo-polygalacturonase class I (EC 3.2.1.67) using mass spectrometry and Western-Blotting. Capillary electrophoresis indicated that only galacturonic acid was released by the action of EplNg on sodium polypectate, confirming an exoenzyme character. The structural model confers that EplNg has a core formed by twisted parallel β-sheets structure. Among twelve putative cysteines, ten were predicted to form disulfide bridges. The catalytic triad predicted is composed of Asp223, Asp245, and Asp246 aligned along with a distance in 4–5 Å, suggesting that EplNg probably does not perform the standard inverting catalytic mechanism described for the GH28 family. EplNg was active from 30 to 90 °C, with maximum activity at 65 °C, pH 5.0. The Km and Vmax determined using sodium polypectate were 6.9 mg·mL−1 and Vmax 690 μmol·min−1.mg−1, respectively. EplNg was active and stable over a wide range of pH values and temperatures, confirming the interesting properties EplNg and provide a basis for the development of the enzyme in different biotechnological processes.

Starch structure-property relations in Australian wild rices compared to domesticated rices

There are many genetic differences between Australian wild rices (AWRs) and domesticated rices (DRs), causing differences in starch molecular structure and starch-related functional properties; these are examined here for polished AWRs and polished DRs. Starch structural parameters for amylopectin and amylose were obtained using size-exclusion chromatography, with and without enzymatic debranching. Thermal properties of starch, in-vitro digestibility and texture of three AWRs were measured and compared to those of typical DRs. The results showed that AWR starches had (a) higher amylose content than most DRs, resulting in a higher gelatinization temperature, (b) fewer amylopectin short chains, causing a higher gelatinization enthalpy, and (c) more amylose shorter chains and more amylopectin longer chains, both causing a slower in-vitro digestion rate. The textural characteristics of AWRs are not significantly different from those of DRs. These findings suggest that AWRs are a potential source of nutritionally-desirable but palatable slowly-digestible starch.

Assessment of the Structure, Digestion Absorption Properties and Nutritive Value of Collagen Peptide

Collagen peptide is a type of peptides complex with rich nutritive value and biological functions derived from hydrolysis of collagen. Based on the debate in recent years that whether it is useful to supply collagen, this article provides comprehensive description of collagen peptide and collagen from the aspects of structure composition and functional properties and applications. Collagen peptide products that have been applied in food industry and health care field in recent years were reviewed. A significant body of this work had been devoted to the statements about digestion absorption properties, nutritive value and biological function of collagen hydrolysates. The outlook for prospect and developing priority of collagen peptide were described. Ultimately, this review can serve as a reference for the exploration and utilizing of collagen peptide.

Defined shear and heat treatment of apple pomace: impact on dietary fiber structures and functional properties

Food by-products can be modified by extrusion processing. However, the impact of thermal and mechanical stress, respectively, on the structure and thus functional properties of dietary fiber-rich food by-products is still unknown. In the extrusion process, thermal and mechanical stress are coupled, not constant, and difficult to measure or calculate. Thus, their influence on structural changes and functional properties cannot be evaluated separately. In this work, a specific shear cell, denoted by closed cavity rheometer, was used to treat apple pomace with defined thermal and/or mechanical stress. Dietary fiber composition and fiber polysaccharide structures appeared to be more susceptible to high temperatures than mechanical stress. With increasing temperature (and mechanical stress) soluble and low-molecular-weight soluble dietary fiber contents increased, whereas insoluble fiber contents decreased. Arabinans as rhamnogalacturonan type I polysaccharides and galacturonic acid containing pectic polysaccharides were identified as being most susceptible to degradation under these conditions. Furthermore, the defined treatment affected the functional properties. Although changes in the water solubility index (WSI) and/or the water absorption index (WAI) were not detected up to 90 °C, WSI and WAI decreased significantly at a treatment temperature of 120 °C. However, at very high temperatures (160 °C), WSI and WAI increased. The application of shear and longer treatment times resulted in higher WSI values and complex viscosities as compared to low shear stress.Graphic abstract

The Goldilocks Principle: A Unifying Perspective on Biochemical Adaptation to Abiotic Stressors in the Sea.

The ability of marine organisms to thrive over wide ranges of environmental stressors that perturb structures of proteins, nucleic acids, and lipids illustrates the effectiveness of adaptation at the biochemical level. A critical role of these adaptations is to achieve a proper balance between structural rigidity, which is necessary for maintaining three-dimensional conformation, and flexibility, which is required to allow changes in conformation during function. The Goldilocks principle refers to this balancing act, wherein structural stability and functional properties are poised at values that are just right for the environment the organism faces. Achieving this balance involves changes in macromolecular sequence and adaptive change in the composition of the aqueous or lipid milieu in which macromolecules function. This article traces the development of the field of biochemical adaptation throughout my career and shows how comparative studies of marine animals from diverse habitats have shed light on fundamental properties of life common to all organisms.