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183 results on '"Shi, Wenzheng"'

1. Reciprocal theorem for linear poro-viscoelastic materials

Author

Moradi, Moslem, Shi, Wenzheng, and Nazockdast, Ehssan

Subjects
Condensed Matter - Soft Condensed Matter, Physics - Fluid Dynamics
Abstract

In studying the transport of particles and inclusions in multi-phase systems we are often interested in integrated quantities such as the total force and the net velocity of the particles. Here, we derive a reciprocal formulation for linear poro-viscoelastic (PVE) materials, which are composed of a linear compressible viscoelastic phase, i.e. the network phase, permeated by a viscous fluid. As an application of the reciprocal theorem, we analytically calculate the time-dependent net force on a rigid stationary sphere in response to point-forces applied to the elastic network and Newtonian fluid phases of a PVE material. We show that the net force on the sphere in response to a point-force in the fluid phase evolves over timescales that are independent of the distance of the point-force to the sphere; in comparison, when the point-force is applied to the network phase the timescale for force development becomes distance-dependent. We discuss how in both cases these relaxation times are related to the physical timescales that are determined by mechanical properties of both phases -- such as the network's Poisson ratio, permeability and shear modules, and the fluid viscosity -- as well as geometric factors, including the size of the spherical inclusion and its distance from point-forces. The reciprocal theorem presented here can be applied to a wide range of problems involving the transport of cells, organelles and condensates in biological systems composed of filamentous networks permeated by viscous fluids.

Published
2023

2. The drag of a filament moving in a supported spherical bilayer

Author

Shi, Wenzheng, Moradi, Moslem, and Nazockdast, Ehssan

Subjects
Physics - Fluid Dynamics, Condensed Matter - Soft Condensed Matter
Abstract

Many of the cell membrane vital functions are achieved by the self-organization of the proteins and biopolymers embedded in it. The protein dynamics are in part determined by its drag. A large number of these proteins can polymerize to form filaments. In-vitro studies of protein-membrane interactions often involve using rigid beads coated with lipid bilayers, as a model for the cell membrane. Motivated by this, we use slender-body theory to compute the translational and rotational resistance of a single filamentous protein embedded in the outer layer of a supported bilayer membrane and surrounded on the exterior by a Newtonian fluid. We first consider the regime, where the two layers are strongly coupled through their inter-leaflet friction. We find that the drag along the parallel direction grows linearly with the filament length and quadratically with the length for perpendicular and the rotational drag coefficients. These findings are explained using scaling arguments and by analyzing the velocity fields around the moving filament. We, then, present and discuss the qualitative differences between the drag of a filament moving in a freely suspended bilayer and a supported membrane as a function of the membrane inter-leaflet friction. Finally, we briefly discuss how these findings can be used in experiments to determine membrane rheology. In summary, we present a formulation that allows computing the effects of membrane properties (its curvature, viscosity, and inter-leaflet friction), and the exterior and interior 3D fluids depth and viscosity on the drag of a rod-like or filamentous protein, all in a unified theoretical framework.

Published
2023

3. Evaluation of Stability and Biocompatibility of Chitosan/Sodium Tripolyphosphate and Chitosan/Flaxseed Gum Composite Nanoparticles Loaded with Bighead Carp Peptides

Author

ZHENG Changliang, CHEN Mengting, WANG Lan, QU Yinghong, SHI Wenzheng, SHI Liu, CHEN Sheng, QIAO Yu, LI Xin, GUO Xiaojia, WU Wenjin, YANG Yuping

Subjects
chitosan, nanoparticle, stability, biocompatibility, Food processing and manufacture, TP368-456
Abstract

Chitosan nanoparticle is becoming an excellent carrier for the delivery of bioactive components due to the advantages of simple preparation, low cost and high biocompatibility. Previous studies have shown that chitosan/sodium tripolyphosphate (CS/TPP) and chitosan/flaxseed gum (CS/FG) nanoparticles loaded with bighead carp peptides (BCP) have the advantages of small particle size, high encapsulation rate and significant slow-release effect. This study explored the effects of ionic strength, pH, simulated digestion and storage time on the preparation of chitosan/sodium tripolyphosphate (CS/TPP-BCP) and chitosan/flaxseed gum (CS/FG-BCP) nanoparticles, and evaluated the extracellular lactate dehydrogenase content and antioxidant capacity in vivo of Caco-2 cells treated with the chitosan nanoparticles and their cellular uptake. The results showed that the two kinds of chitosan nanoparticles were stable under acidic conditions and sensitive to a solution with opposite charges. The stability of the nanoparticles loaded with bighead peptides was higher than that of free peptides and both nanoparticles showed higher biocompatibility and cell uptake.

Published
2023
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4. Hydrodynamics of a single filament moving in a fluid spherical membrane

Author

Shi, Wenzheng, Moradi, Moslem, and Nazockdast, Ehssan

Subjects
Physics - Fluid Dynamics, Condensed Matter - Soft Condensed Matter, Physics - Biological Physics
Abstract

Dynamic organization of the cytoskeletal filaments and rod-like proteins in the cell membrane and other biological interfaces occurs in many cellular processes. Previous modeling studies have considered the dynamics of a single rod on fluid planar membranes. We extend these studies to the more physiologically relevant case of a single filament moving in a spherical membrane. Specifically, we use a slender-body formulation to compute the translational and rotational resistance of a single filament of length $L$ moving in a membrane of radius $R$ and 2D viscosity $\eta_m$, and surrounded on its interior and exterior with Newtonian fluids of viscosities $\eta^{-}$ and $\eta^{+}$. We first discuss the case where the filament's curvature is at its minimum $\kappa=1/R$. We show that the boundedness of spherical geometry gives rise to flow confinement effects that increase in strength with increasing the ratio of filament's length to membrane radius $L/R$. These confinement flows only result in a mild increase in filament's resistance along its axis, $\xi_{\parallel}$, and its rotational resistance, $\xi_{\Omega}$. As a result, our predictions of $\xi_\parallel$ and $\xi_{\Omega}$ can be quantitatively mapped to the results on a planar membrane. In contrast, we find that the drag in perpendicular direction, $\xi_\perp$, increases superlinearly with the filament's length, when $L/R >1$ and ultimately $\xi_\perp \to \infty$ as $L/R \to \pi$. Next, we consider the effect of the filament's curvature, $\kappa$, on its parallel motion, while fixing the membrane's radius. We show that the flow around the filament becomes increasingly more asymmetric with increasing its curvature. These flow asymmetries induce a net torque on the filament, coupling its parallel and rotational dynamics. This coupling becomes stronger with increasing $L/R$ and $\kappa$., Comment: 13 pages, 6 figures

Published
2022

7. General solutions of poroelastic equations with viscous stress

Author

Moradi, Moslem, Shi, Wenzheng, and Nazockdast, Ehssan

Subjects
Condensed Matter - Soft Condensed Matter, Physics - Fluid Dynamics
Abstract

Mechanical properties of cellular structures, including the cell cytoskeleton, are increasingly used as biomarkers for disease diagnosis and fundamental studies in cell biology. Recent experiments suggest that the cell cytoskeleton and its permeating cytosol, can be described as a poroelastic (PE) material. Biot theory is the standard model used to describe PE materials. Yet, this theory does not account for the fluid viscous stress, which can lead to inaccurate predictions of the mechanics in the dilute filamentous network of the cytoskeleton. Here, we adopt a two-phase model that extends Biot theory by including the fluid viscous stresses in the fluid's momentum equation. We use generalized linear viscoelastic (VE) constitutive equations to describe the permeating fluid and the network stresses and assume a constant friction coefficient that couples the fluid and network displacement fields. As the first step in developing a computational framework for solving the resulting equations, we derive closed-form general solutions of the fluid and network displacement fields in spherical coordinates. To demonstrate the applicability of our results, we study the motion of a rigid sphere moving under a constant force inside a PE medium, composed of a linear elastic network and a Newtonian fluid. We find that the network compressibility introduces a slow relaxation of the sphere and a non-monotonic network displacements with time along the direction of the applied force. These novel features cannot be predicted if VE constitutive equation is used for the medium. We show that our results can be applied to particle-tracking microrheology to differentiate between PE and VE materials and to independently measure the permeability and VE properties of the fluid and the network phases.

Published
2021

8. Effect of NaCl on the Quality of Aquatic Products and Research Progress on Salt Reduction Technologies

Author

HUANG Shiyu, SHI Wenzheng, WANG Xichang, JIANG Qingqing

Subjects
role of nacl, convenience foods with low salt content, sodium salt substitutes, salt reduction technologies, aquatic products, Food processing and manufacture, TP368-456
Abstract

Salt content is essential for the quality of aquatic products, especially for the water-holding capacity and textural properties of salted products and the gel properties of surimi-based products. However, the salt content in traditional aquatic products is generally too high to meet consumers’ demand for healthy convenience foods with low salt content. Reducing the salt content will decrease the storage stability, eating quality and processing properties of aquatic products. Therefore, reducing the salt content without sacrificing the quality is an important issue faced by the aquatic product processing industry. The premise and basis of effectively controlling the quality of aquatic products with low salt content is to clarify the effect and mechanism of NaCl on the quality of aquatic products. In the present paper, we review the role of NaCl in the processing and storage of aquatic products and the latest progress of salt reduction technologies from the aspects of NaCl substitution, novel salt reduction technologies, and sodium release/perception enhancement technologies, and we discuss the problems with the processing of salt-reduced aquatic products. The present article may provide valuable information for high-quality processing of lightly salted aquatic products.

Published
2023
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11. Effect of Ultrasound-Assisted Thawing on the Quality of Euphausia superba and Its Changes during Cold Storage

Author

QIAN Yunfang, YU Jiayi, WANG Minchen, ZHANG Qu, WANG Chuyan, ZHU Guoping, SHI Wenzheng, YANG Shengping

Subjects
antarctic krill, ultrasound-assisted thawing, cold storage, quality, Food processing and manufacture, TP368-456
Abstract

In order to study the effect of ultrasound-assisted thawing on the quality of Antarctic krill (Euphausia superba) and its changes during cold storage, frozen Antarctic krill was placed into net bags or polyethylene (PE) bags and thawed by water immersion with or without ultrasound treatment. The quality changes of thawed samples during cold storage were evaluated in terms of sensory scores, microbial growth, hardness, total volatile basic nitrogen (TVB-N) content, polyphenol oxidase (PPO) activity and trypsin activity as well as the signal intensity of hydrogen protons in low field nuclear magnetic resonance. The thawing time was 105 and 145 min for net bag and plastic bag packaging combined with water immersion thawing, respectively, while it took only 65 and 75 min for net bag and plastic bag packaging combined with ultrasound-assisted immersion thawing. After thawing, the sensory score of Antarctic krill continued to decline during storage at 4 ℃ and reached an unacceptable level after 24 h of storage. However, the total viable count remained less than 2.5 (lg (CFU/g)) before and after thawing and during subsequent cold storage for 28 h, but the activity of PPO and trypsin increased firstly and decreased at the end of storage, while TVB-N content increased during storage. The quality of thawed Antarctic krill contained in net bags deteriorated more slowly than in plastic bags. Collectively, net bag packaging combined with ultrasound-assisted thawing can not only accelerate the thawing rate, but also improve the storability of Antarctic krill.

Published
2023
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20. Effects of Ultrasonic Power on the Structure and Rheological Properties of Skin Collagen from Albacore (Thunnus alalunga).

Author

Pan, Hao, Zhang, Xuehua, Ni, Jianbo, Liang, Qianqian, Jiang, Xin, Zhou, Zihui, and Shi, Wenzheng

Abstract

The effects of ultrasonic power (0, 150, 300, 450, and 600 W) on the extraction yield and the structure and rheological properties of pepsin-soluble collagen (PSC) from albacore skin were investigated. Compared with the conventional pepsin extraction method, ultrasonic treatment (UPSC) significantly increased the extraction yield of collagen from albacore skin, with a maximum increase of 8.56%. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that peptides of low molecular weight were produced when the ultrasonic power exceeded 300 W. Meanwhile, secondary structure, tertiary structure, and X-ray diffraction analyses showed that the original triple helix structure of collagen was intact after the ultrasonic treatment. The collagen solutions extracted under different ultrasonic powers had significant effects on the dynamic frequency sweep, but a steady shear test suggested that the collagen extracted at 150 W had the best viscosity. These results indicate that an ultrasonic power between 150 and 300 W can improve not only the extraction yield of natural collagen, but also the rheological properties of the collagen solution without compromising the triple helix structure. [ABSTRACT FROM AUTHOR]

Published
2024
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23. Landscape management for urban green space multifunctionality : a comparative study in Sheffield (UK) and Yuci (China)

Author

Shi, Wenzheng, Woolley, Helen, and Selman, Paul

Subjects
712
Abstract

The key purpose of this thesis is to investigate how the concept of multifunctionality, applied to the totality of green infrastructure, can help to underpin an improvement in the management of urban green space. The thesis uses a paired comparison study to investigate ways of enhancing landscape multifunctionality in green infrastructure through improved management in different cities. This study compares actual and potential prospects for development of green infrastructure in Sheffield, UK and Yuci, China. Landscape management plays a key role in improving the quality of urban environments and enhancing green infrastructure. The concept of multifunctionality has been considered as a core property of green infrastructure and has been particularly impacted in Europe, UK and USA. However, most literature on green infrastructure emphasises its spatial planning phases, and usually gives less attention to landscape management aspects. Therefore, this thesis concentrates on management aspects of green infrastructure; particularly those that enhance its multifunctionality. This research commences with a literature review to understand related research and management background. Subsequently, Geographic Information System (GIS) is used to show and explain what kind of green spaces and multifunctionality are present. Based on GIS mapping, relevant policies and plans are reviewed and evaluated in selected cities, supplemented by interviews with landscape managers. The interviews provide particular insights into implementing action and monitoring of management proposals and actions. As a comparative study, this thesis has critically compared national and local policy contexts for green spaces in the UK and China. Based on mapping exercises and policy analysis, a representative set of management practices and specifications have been selected for more detailed analysis. The extent to which these documents contain multifunctional management approaches has been undertaken by evaluating them in relation to multifunctionality criteria. It is clear that there are significant differences in practices between Sheffield and Yuci, although, many of their needs are similar. One output of the research is to contribute to 'knowledge exchange' as a way of improving policy and practice. The comparative case studies in this thesis identify a number of potential factors in management for improving multifunctional green infrastructure. The roles of policy, management approach, and comprehension of multifunctionality among managers are discussed in order to ascertain the ways in which multifunctionality can be promoted in green infrastructure. Some of the benefits and barriers in the management process such as legislation and resources are discussed to investigate potential opportunities. On the other hand, the experiences of management from different backgrounds are explored as a basis for knowledge exchange.

Published
2013

43. Effect of extraction methods on the preparation of electrospun/electrosprayed microstructures of tilapia skin collagen

Author

Ruihua Guo, Qi Xin, Han Wei, Chunhuan Bi, Cuiping Shi, Ruirui Qiao, Li Xiaohui, Jian Zhong, Shi Wenzheng, and Xichang Wang

Subjects
0106 biological sciences, 0301 basic medicine, Hot Temperature, business.product_category, food.ingredient, Sodium, chemistry.chemical_element, Bioengineering, Chemical Fractionation, 01 natural sciences, Applied Microbiology and Biotechnology, Protein Structure, Secondary, 03 medical and health sciences, Acetic acid, chemistry.chemical_compound, food, Electricity, 010608 biotechnology, Spectroscopy, Fourier Transform Infrared, Microfiber, Animals, Sodium Hydroxide, Acetic Acid, Skin, Gel electrophoresis, chemistry.chemical_classification, Chromatography, Chemistry, Water, Tilapia, Polymer, Electrospinning, Molecular Weight, 030104 developmental biology, Sodium hydroxide, Receptors, FSH, Collagen, business, Biotechnology
Abstract

Collagen plays a pivotal role in human physiological functions and extracted collagen has multiple potential applications. Tilapia skin can be applied to extract collagen for maximizing the profit of tilapia processing. Electrospinning/electrospraying is novel micro- and nano-techniques to fabricate microfibers and microspheres in a simple and easy way. In this work, we extract collagens from tilapia skin by three types of extraction methods: acetic acid method, hot water method, and sodium hydroxide method. Then, these extracted collagens are characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Fourier transform infrared spectrometry. These extracted collagens have different molecular weights and different protein secondary structures. Finally, these extracted collagens are applied to fabricate electrosprayed microspheres, electrospun microfibers, and mixed microspheres/microfibers with multiple potential applications by adjusting the collagen concentrations. Higher polymer molecular weight only needs lower concentration to produce microfibers. The microfiber diameter increases with the increase of collagen concentration. This work proves that extraction methods have obvious effect on the preparation of electrospun/electrosprayed microstructures of tilapia skin collagen and provide a way to maximize resource utilization of tilapia processing waste.

Published
2019

46. Characterization of the effect of different sugar on volatile flavor compounds of dried fish floss using e‐nose combined with HS‐SPME/GC‐MS.

Author

Chen, Qing, Jiang, Xin, Xiao, Naiyong, Feng, Qian, Liu, Junya, and Shi, Wenzheng

Subjects
FOOD aroma, GAS chromatography/Mass spectrometry (GC-MS), SUCROSE, FLAVOR, ELECTRONIC noses, MAILLARD reaction, FATTY acid analysis
Abstract

The aim of this study was to evaluate volatile compounds of dried fish floss with different sugar using electronic nose (e‐nose) and headspace‐solid‐phase microextraction/gas chromatography‐mass spectrometry (HS‐SPME/GC‐MS). Maillard reaction (MR) was carried out by reducing sugar (glucose, xylose, fructose, and galactose) instead of sucrose to increase the flavor of fish floss. The results showed that 64 volatile compounds were detected in fish floss. Hexanal, heptanal, nonanal, decanal, undecanal, tridecanal, pentadecanal, 4‐ethyl‐benzaldehyde, dodecanal, benzene acetaltaldehyde, (E, E)‐2,6‐nonadienal, (E, E)‐2,4‐decadienal, 2‐undecanone, 1‐octen‐3‐ol, (E)‐2‐hepten‐1‐ol, 1‐heptanol, and 2‐pentyl‐furan were regarded as key volatile compounds. Furthermore, e‐nose and partial least squares‐discriminant analysis (PLS‐DA) showed that there were significant differences in flavor among fish floss samples. The correlation analysis of browning index, fatty acids, and key volatile compounds confirmed that MR and lipid oxidation made a great contribution to the flavor formation. These results might provide guidance for the production and flavor formation of fish floss. Practical applications: Dried fish floss deeply loved by the public is a traditional leisure food with unique odor and delicious taste. The attractive flavor of dried fish floss could be increased with the help of the Maillard reaction (MR). The type of sugar in MR has a great influence on the reaction process and the flavor of substances. The comprehensive information on the flavor among the dried fish floss with different sugar (sucrose, glucose, xylose, fructose, and galactose) was characterized by using HS‐SPME/GC‐MS, electronic nose (E‐nose), and fatty acid analysis, which may provide a reference for the quality improvement of dried fish floss. [ABSTRACT FROM AUTHOR]

Published
2022
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49. Sensory quality and digestibility evaluation of silver carp sausage glycated with l‐arabinose.

Author

Liu, Junya, Huang, Shuqin, Feng, Qian, Luo, Yixuan, and Shi, Wenzheng

Subjects
SILVER carp, TASTE, SAUSAGES, PRINCIPAL components analysis, SMELL
Abstract

This study focused on the effect of different levels of l‐arabinose addition on the sensory quality and digestibility of silver carp sausage by testing color, texture, smell, taste, sensory score, and digestibility. The results showed that the L* value of fish sausage decreased with the increase of l‐arabinose, while a* value, b* value, and BI increased. In addition, the hardness, springiness, and chewiness of fish sausage reached the maximum when adding 2% l‐arabinose. Principal component analysis results of E‐nose and E‐tongue data showed that l‐arabinose enhanced the aroma and taste profiles. Sensory evaluation found that fish sausage with 2% l‐arabinose had the highest overall acceptability. Moreover, the addition of 2% arabinose could better maintain the protein digestibility of fish sausage intact. This study has suggested a promising potential for applying glycation in aquatic product processing and the development of nutritious ready‐to‐eat fish products using l‐arabinose. Novelty impact statement: This work investigates the impact of different levels of l‐arabinose addition on the color, texture, smell, taste, and digestibility of silver carp sausage. It explains how the change of glycation degree affects the sensory quality and digestibility of silver carp sausage. Fish sausage with good overall acceptability and digestibility was obtained by adding 2% l‐arabinose. This work contributes a theoretical basis for applying glycation in aquatic product processing and developing nutritious ready‐to‐eat fish products using l‐arabinose. [ABSTRACT FROM AUTHOR]

Published
2022
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50. Effect of different drying time on physicochemical properties of black carp (Mylopharyngodon piceus) by hot air.

Author

Wang, Yixin, Huang, Haiyuan, and Shi, Wenzheng

Subjects
SATURATED fatty acids, MONOUNSATURATED fatty acids, UNSATURATED fatty acids, CARP, FATTY acids
Abstract

The dried black carp was studied based on moisture content, color, aerobic plate count (APC), total volatile basic nitrogen (TVB‐N), peroxide value (POV), thiobarbituric acid reactive substance (TBARS), fatty acids, free amino acids, and nucleotides to explore the physicochemical properties changes. After drying for 12 hr, moisture content dropped to 42.53% and color changed obviously. L* value decreased and a* and b* values increased. APC and TVB‐N results indicated fillets had high food safety. POV and TBA both were on the rise in fillets, reaching the maximum values of 0.08 mg/100 g and 2.33 mg MDA/kg, respectively. Monounsaturated fatty acids and polyunsaturated fatty acids were oxidized and decomposed, which led to the increase of saturated fatty acids absolute content. From the results of equivalent umami concentration, fillets reached the maximum value of 9.04 g MSG/100 g. The longer the drying time, the worse the taste quality in products. Practical applications: In order to investigate the quality changes of black carp during drying, physical properties, lipid oxidation, and nonvolatile flavor substances were analyzed. From this article, it can be found that during the process of drying, the black carp was in a safe state. The results of this article provided theoretical and technical support for black carp. [ABSTRACT FROM AUTHOR]

Published
2022
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