scholarly journals Preconditioning process for dermal tissue decellularization using electroporation with sonication

2021 ◽  
Author(s):  
Min-Ah Koo ◽  
HaKyeong Jeong ◽  
Seung Hee Hong ◽  
Gyeung Mi Seon ◽  
Mi Hee Lee ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Complex Structure ◽  
Biological Tissues ◽  
Future Research ◽  
Histochemical Analysis ◽  
Physical Stimulation ◽  
Physical Methods ◽  
Dermal Tissue ◽  
Triton X ◽  
Cellular Components

Abstract Decellularization to produce bioscaffolds composed of the extracellular matrix (ECM) uses enzymatic, chemical, and physical methods to remove antigens and cellular components from tissues. Effective decellularization methods depend on the characteristics of tissues, and in particular, tissues with dense, complex structure and abundant lipid content are difficult to completely decellularize. Our study enables future research on the development of methods and treatments for fabricating bioscaffolds via decellularization of complex and rigid skin tissues, which are not commonly considered for decellularization to date as their structural and functional characteristics could not be preserved after severe decellularization. In this study, decellularization of human dermal tissue was done by a combination of both chemical (0.05% trypsin-EDTA, 2% SDS, 1% Triton X-100) and physical methods (electroporation, sonication). After decellularization, the content of DNA remaining in the tissue was quantitatively confirmed, and the structural change of the tissue and the retention and distribution of ECM components were evaluated through histological and histochemical analysis, respectively. Conditions of the chemical pretreatment that increase the efficiency of physical stimulation as well as decellularization, and conditions for electroporation and sonication without the use of detergents, unlike the methods performed in previous studies, were established to enable the complete decellularization of the skin tissue. The combinatorial decellularization treatment formed micropores in the lipid bilayers of the skin tissues while removing all cell and cellular residues without affecting the ECM properties. Therefore, this procedure can be widely used to fabricate bioscaffolds by decellularizing biological tissues with dense and complex structures.

scholarly journals Biomechanical-Structural Correlation of Chordae tendineae in Animal Models: A Pilot Study

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1678
Author(s):  
Justyn Gach ◽  
Izabela Janus ◽  
Agnieszka Mackiewicz ◽  
Tomasz Klekiel ◽  
Agnieszka Noszczyk-Nowak
Keyword(s):  
Mitral Valve ◽  
Complex Structure ◽  
Future Research ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Histopathological Analysis ◽  
Papillary Muscles ◽  
Chordae Tendineae ◽  
Structural Correlation ◽  
Ring Valve

The mitral valve apparatus is a complex structure consisting of the mitral ring, valve leaflets, papillary muscles and chordae tendineae (CT). The latter are mainly responsible for the mechanical functions of the valve. Our study included investigations of the biomechanical and structural properties of CT collected from canine and porcine hearts, as there are no studies about these properties of canine CT. We performed a static uniaxial tensile test on CT samples and a histopathological analysis in order to examine their microstructure. The results were analyzed to clarify whether the changes in mechanical persistence of chordae tendineae are combined with the alterations in their structure. This study offers clinical insight for future research, allowing for an understanding of the process of chordae tendineae rupture that happens during degenerative mitral valve disease—the most common heart disease in dogs.

scholarly journals Towards Automated Analysis of Research Methods in Library and Information Science

2021 ◽  
pp. 1-39 ◽  
Author(s):  
Ziqi Zhang ◽  
Winnie Tam ◽  
Andrew Cox
Keyword(s):  
Research Methods ◽  
Information Science ◽  
Scientific Literature ◽  
Complex Structure ◽  
Automated Analysis ◽  
Future Research ◽  
Library And Information Science ◽  
Diverse Range ◽  
Automated Recognition ◽  
Automated Method

Previous studies of research methods in LIS lack consensus in how to define or classify research methods, and there have been no studies on automated recognition of research methods in the scientific literature of this field. This work begins to fill these gaps by studying how the scope of ‘research methods’ in LIS has evolved, and the challenges in automatically identifying the usage of research methods in LIS literature. 2,599 research articles are collected from three LIS journals. Using a combination of content analysis and text mining methods, a sample of this collection is coded into 29 different concepts of research methods and is then used to test a rule-based automated method for identifying research methods reported in scientific literature. We show that the LIS field is characterised by the use of an increasingly diverse range of methods, many of which originate outside the conventional boundaries of LIS. This implies increasing complexity in research methodology and suggests the need for a new approach towards classifying LIS research methods to capture the complex structure and relationships between different aspects of methods. Our automated method is the first of its kind in LIS, and sets an important reference for future research.

scholarly journals Understanding Workplace Interpersonal Mistreatment in the NZ Military: Structure, Antecedents and Consquences

2021 ◽  
Author(s):  
◽  
Kimberley Eve Ballantyne
Keyword(s):  
Structural Equation ◽  
Safety Climate ◽  
Complex Structure ◽  
Health And Safety ◽  
Future Research ◽  
Plausible Model ◽  
Two Samples ◽  
Climate And Health ◽  
Antecedents And Consequences ◽  
Military Structure

<p>This thesis describes the development and testing of a theoretically plausible model of antecedents and consequences of workplace interpersonal mistreatment using archival data (n = 10697) of civilian and military employees. The sample was split into calibration and validation samples. Principle component and confirmatory factor analysis revealed a complex structure for the workplace interpersonal mistreatment construct across three types of behaviour, and across observed and experienced mistreatment. Furthermore, a total of 17 robust factors were identified in the survey, of which a subset of eight factors was used for developing the model of antecedents and consequences of WIM. The model was tested and refined using regression and structural equation modelling in two samples and validated in a third sample. Individual (seniority), workplace (directive leadership, equity and diversity climate, and health and safety climate) and organisational features (aligned-cohesive culture, service culture) all predict mistreatment. Outcomes of mistreatment include stress, organisational commitment, job satisfaction and leaving intentions. The model showed good fit in the validation sample and is therefore likely to generalise to the population. Implications for organisations and recommendations for future research are discussed.</p>

Bioremediation of Pesticides under the Influence of Bacteria and Fungi

2015 ◽  
pp. 51-72 ◽  
Author(s):  
Mamta ◽  
Rayavarapu Jaganadha Rao ◽  
Khursheed Ahmad Wani
Keyword(s):  
Scientific Community ◽  
Cost Effective ◽  
Future Research ◽  
Complex Nature ◽  
Potential Threat ◽  
Physical Methods ◽  
Effective Manner ◽  
The Future ◽  
Research Problems ◽  
Bacteria And Fungi

The demand and development of chemicals, pesticides, fertilizers, and pharmaceuticals is increasing constantly posing a potential threat to the environment. The presence of pesticides and their impact makes their removal and detoxification a more urgent need. Bioremediation technologies have been successfully used and are gaining more and more importance with increased acceptance of eco-friendly remediation solutions among the scientific community. Bioremediation by fungi and bacteria is considered a better option for making environment free from pesticides, as chemical and physical methods are not only costly but also not very effective. However, the complex nature of pesticides is an obstacle to degrade the pesticides, so more versatile and robust microorganisms need to be identified which can produce the desired result in a very cost-effective manner. This study examines the role played by fungi and bacteria in degradation of the pesticides in environment and also identify the future research problems in this regard that need to be experimented.

scholarly journals Extracellular Vesicle Biogenesis and Functions in Gram-Positive Bacteria

2020 ◽  
Vol 88 (12) ◽  
Author(s):  
Paul Briaud ◽  
Ronan K. Carroll
Keyword(s):  
Lipid Bilayers ◽  
Membrane Vesicles ◽  
Cell Interaction ◽  
Extracellular Vesicle ◽  
Wall Structure ◽  
Future Research ◽  
Gram Positive ◽  
Content Type ◽  
Bacterial Physiology ◽  
Gram Positive Bacteria

ABSTRACT Extracellular vesicles (EVs) are membrane-derived lipid bilayers secreted by bacteria and eukaryotic cells. Bacterial membrane vesicles were discovered over 60 years ago and have been extensively studied in Gram-negative bacteria. During their production, EVs are loaded with proteins, nucleic acids, and various compounds that are subsequently released into the environment. Depending on the packaged cargo, EVs have a broad spectrum of action and are involved in pathogenesis, antibiotic resistance, nutrient uptake, and nucleic acid transfer. Due to differences in cell wall structure, EVs in Gram-positive bacteria have been disregarded for decades, and our understanding of their biogenesis and host cell interaction is incomplete. Recently, studies on bacteria such as Staphylococcus aureus, Streptococcus spp., Bacillus subtilis, and Mycobacterium spp. have demonstrated EV production in Gram-positive bacteria and shown the great importance EVs have in Gram-positive bacterial physiology and disease progression. Here, we review the latest findings on the biogenesis and functions of EVs from Gram-positive bacteria and identify key areas for future research.

Toward a mathematical theory of Keller–Segel models of pattern formation in biological tissues

2015 ◽  
Vol 25 (09) ◽  
pp. 1663-1763 ◽  
Author(s):  
N. Bellomo ◽  
A. Bellouquid ◽  
Y. Tao ◽  
M. Winkler
Keyword(s):  
Blow Up ◽  
Existence Of Solutions ◽  
Biological Tissues ◽  
Original Model ◽  
Future Research ◽  
Macroscopic Models ◽  
The Third ◽  
Research Activities ◽  
Classical Models ◽  
Chemotaxis Models

This paper proposes a survey and critical analysis focused on a variety of chemotaxis models in biology, namely the classical Keller–Segel model and its subsequent modifications, which, in several cases, have been developed to obtain models that prevent the non-physical blow up of solutions. The presentation is organized in three parts. The first part focuses on a survey of some sample models, namely the original model and some of its developments, such as flux limited models, or models derived according to similar concepts. The second part is devoted to the qualitative analysis of analytic problems, such as the existence of solutions, blow-up and asymptotic behavior. The third part deals with the derivation of macroscopic models from the underlying description, delivered by means of kinetic theory methods. This approach leads to the derivation of classical models as well as that of new models, which might deserve attention as far as the related analytic problems are concerned. Finally, an overview of the entire contents leads to suggestions for future research activities.

scholarly journals Lipid Bilayers in the Gel Phase Become Saturated by Triton X-100 at Lower Surfactant Concentrations Than Those in the Fluid Phase

2012 ◽  
Vol 102 (11) ◽  
pp. 2510-2516 ◽  
Author(s):  
Hasna Ahyayauch ◽  
M. Isabel Collado ◽  
Alicia Alonso ◽  
Felix M. Goñi
Keyword(s):  
Lipid Bilayers ◽  
Fluid Phase ◽  
Gel Phase ◽  
Triton X

scholarly journals Anthropomorphic Breast and Head Phantoms for Microwave Imaging

Diagnostics ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 85 ◽  
Author(s):  
Nadine Joachimowicz ◽  
Bernard Duchêne ◽  
Christophe Conessa ◽  
Olivier Meyer
Keyword(s):  
Liquid Mixtures ◽  
Biological Tissues ◽  
Microwave Imaging ◽  
Breast Cancer Imaging ◽  
Minimization Method ◽  
Fluid Mixture ◽  
Breast Phantom ◽  
Brain Stroke ◽  
The Cost ◽  
Triton X

This paper deals with breast and head phantoms fabricated from 3D-printed structures and liquid mixtures whose complex permittivities are close to that of the biological tissues within a large frequency band. The goal is to enable an easy and safe manufacturing of stable-in-time detailed anthropomorphic phantoms dedicated to the test of microwave imaging systems to assess the performances of the latter in realistic configurations before a possible clinical application to breast cancer imaging or brain stroke monitoring. The structure of the breast phantom has already been used by several laboratories to test their measurement systems in the framework of the COST (European Cooperation in Science and Technology) Action TD1301-MiMed. As for the tissue mimicking liquid mixtures, they are based upon Triton X-100 and salted water. It has been proven that such mixtures can dielectrically mimic the various breast tissues. It is shown herein that they can also accurately mimic most of the head tissues and that, given a binary fluid mixture model, the respective concentrations of the various constituents needed to mimic a particular tissue can be predetermined by means of a standard minimization method.

scholarly journals Chemical activation of the mechanotransduction channel Piezo1

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Ruhma Syeda ◽  
Jie Xu ◽  
Adrienne E Dubin ◽  
Bertrand Coste ◽  
Jayanti Mathur ◽  
...  
Keyword(s):  
Ion Channels ◽  
Lipid Bilayers ◽  
Chemical Activation ◽  
Pressure Sensors ◽  
Inactivation Kinetics ◽  
Mechanical Stimuli ◽  
Functional Studies ◽  
A Cell ◽  
And Function ◽  
Cellular Components

Piezo ion channels are activated by various types of mechanical stimuli and function as biological pressure sensors in both vertebrates and invertebrates. To date, mechanical stimuli are the only means to activate Piezo ion channels and whether other modes of activation exist is not known. In this study, we screened ∼3.25 million compounds using a cell-based fluorescence assay and identified a synthetic small molecule we termed Yoda1 that acts as an agonist for both human and mouse Piezo1. Functional studies in cells revealed that Yoda1 affects the sensitivity and the inactivation kinetics of mechanically induced responses. Characterization of Yoda1 in artificial droplet lipid bilayers showed that Yoda1 activates purified Piezo1 channels in the absence of other cellular components. Our studies demonstrate that Piezo1 is amenable to chemical activation and raise the possibility that endogenous Piezo1 agonists might exist. Yoda1 will serve as a key tool compound to study Piezo1 regulation and function.

scholarly journals Big Data in Finance

2021 ◽  
Author(s):  
Itay Goldstein ◽  
Chester S Spatt ◽  
Mao Ye
Keyword(s):  
Big Data ◽  
Asset Pricing ◽  
Complex Structure ◽  
Future Research ◽  
Special Issue ◽  
Research Directions ◽  
Finance Industry ◽  
Large Size ◽  
Future Research Directions ◽  
New Research

Abstract Big data is revolutionizing the finance industry and has the potential to significantly shape future research in finance. This special issue contains papers following the 2019 NBER-RFS Conference on Big Data. In this introduction to the special issue, we define the “big data” phenomenon as a combination of three features: large size, high dimension, and complex structure. Using the papers in the special issue, we discuss how new research builds on these features to push the frontier on fundamental questions across areas in finance—including corporate finance, market microstructure, and asset pricing. Finally, we offer some thoughts for future research directions.

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