METHODS AND PROTOCOL FLOW CELLS: TECHNIQUE USED FOR STUDYING MICROBIAL BIOFILMS

2016 ◽  
Vol 78 (2) ◽  
Author(s):  
Mohammed Jibrin Ndejiko ◽  
Wan Rosmiza Zana Wan Dagang

Biofilms are sessile communities of microorganisms growing on material surfaces and embedded in self-accumulated extracellular polymers. A comprehensive analysis of physical, chemical and biological factors including hydrodynamic and nutrient conditions that regulate their formation is required to adequately gain insight to this complex multicellular microbial life style. Reproducible experimental models that consider all the conditions under which they grow and develop also remain a required tool for studying the biofilms. As a result of its ability to create hydrodynamic and nutrient conditions coupled with continuous and non-destructive ability to grow biofilms, flow cell technology has become one of the most recently patronised models used to study microbial biofilms. This article focuses on recent advancements, principles and practical application of flow cell technology to study microbial biofilms.

2020 ◽  
Vol 165 ◽  
pp. 04014
Author(s):  
Liu Tao ◽  
Li Jia ◽  
Zheng Zhi-gang ◽  
Huang Zhi ◽  
Jiang Jian ◽  
...  

GPR is an effective non-destructive testing technology. This paper introduces its composition principle and operation method, explains the process of parameter setting and image optimization, obtains the dielectric constant of 10000 points, compares it with the density, and then obtains the uniformity distribution law of construction quality based on image. By calibrating the thickness of the road surface, the effective detection of road diseases can be realized, and the theoretical basis and practical application conditions of GPR technology can be clarified.


2020 ◽  
Vol 401 (12) ◽  
pp. 1365-1374
Author(s):  
Daniel K.H. Rode ◽  
Praveen K. Singh ◽  
Knut Drescher

AbstractBiofilms are a ubiquitous mode of microbial life and display an increased tolerance to different stresses. Inside biofilms, cells may experience both externally applied stresses and internal stresses that emerge as a result of growth in spatially structured communities. In this review, we discuss the spatial scales of different stresses in the context of biofilms, and if cells in biofilms respond to these stresses as a collection of individual cells, or if there are multicellular properties associated with the response. Understanding the organizational level of stress responses in microbial communities can help to clarify multicellular functions of biofilms.


Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 381 ◽  
Author(s):  
Olivier Tytgat ◽  
Yannick Gansemans ◽  
Jana Weymaere ◽  
Kaat Rubben ◽  
Dieter Deforce ◽  
...  

Nanopore sequencing for forensic short tandem repeats (STR) genotyping comes with the advantages associated with massively parallel sequencing (MPS) without the need for a high up-front device cost, but genotyping is inaccurate, partially due to the occurrence of homopolymers in STR loci. The goal of this study was to apply the latest progress in nanopore sequencing by Oxford Nanopore Technologies in the field of STR genotyping. The experiments were performed using the state of the art R9.4 flow cell and the most recent R10 flow cell, which was specifically designed to improve consensus accuracy of homopolymers. Two single-contributor samples and one mixture sample were genotyped using Illumina sequencing, Nanopore R9.4 sequencing, and Nanopore R10 sequencing. The accuracy of genotyping was comparable for both types of flow cells, although the R10 flow cell provided improved data quality for loci characterized by the presence of homopolymers. We identify locus-dependent characteristics hindering accurate STR genotyping, providing insights for the design of a panel of STR loci suited for nanopore sequencing. Repeat number, the number of different reference alleles for the locus, repeat pattern complexity, flanking region complexity, and the presence of homopolymers are identified as unfavorable locus characteristics. For single-contributor samples and for a limited set of the commonly used STR loci, nanopore sequencing could be applied. However, the technology is not mature enough yet for implementation in routine forensic workflows.


2005 ◽  
Vol 52 (7) ◽  
pp. 195-202 ◽  
Author(s):  
R. GrayMerod ◽  
L. Hendrickx ◽  
L.N. Mueller ◽  
J.B. Xavier ◽  
S. Wuertz

Flow cells were utilized to determine the effects of repetitive Syto9 staining on developing Acinetobacter sp. BD413 biofilm and to identify features describing reproducible biofilm architecture at 63× magnification. Syto9 is a general nucleic acid stain employed to visualize the entire microbial population of the biofilm and a component in the LIVE/DEAD® BacLight™ Bacterial Viability kits. CLSM images were quantified with the biofilm analysis software PHLIP to calculate six commonly used biofilm architecture characteristics. The characteristics biovolume and mean thickness were most reproducible when biofilms were grown in separate flow cells under controlled conditions, while roughness, porosity, total spreading and surface area to biovolume ratio exhibited inherent variability. Biovolume was more variable in separate flow cells than in channels of the same flow cell. However, even biofilms grown in channels of the same flow cell did not generate reproducible architectures based on the six characteristics. Results suggest difficulties in differentiating the effect of changes due to treatment from the natural variability of architecture development at the cellular level. Despite this high variability, biofilms only stained once developed into thicker structures containing more biomass than biofilms stained multiple times, suggesting that repeated staining with Syto9 affects architecture development. The application of Syto9 to monitor developing biofilms is not recommended.


2019 ◽  
Vol 220 ◽  
pp. 03012
Author(s):  
Ilia Elmanov ◽  
Anna Elmanova ◽  
Sophia Komrakova ◽  
Alexander Golikov ◽  
Natalya Kaurova ◽  
...  

In the work the thicknesses of the e-beam resists ZEP 520A and ma-N 2400 by using non-destructive method were measured, as well as recipe for the high ratio between the Si3N4 and the resists etching rate was determined. The work has a practical application for e-beam lithography of photonic-integrated circuits and nanophotonics devices based on silicon nitride platform.


2009 ◽  
Vol 75A (2) ◽  
pp. 90-103 ◽  
Author(s):  
Sünje Johanna Pamp ◽  
Claus Sternberg ◽  
Tim Tolker-Nielsen

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Shuo Yang ◽  
Ruquan Liang ◽  
Song Xiao ◽  
Jicheng He ◽  
Shuo Zhang

The influence of airflow shear on the free surface deformation and the flow structure for large Prandtl number fluid (Pr = 111.67) has been analyzed numerically as the parallel airflow shear is induced into the surrounding of liquid bridge from the lower disk or the upper disk. Contrasted with former studies, an improved level set method is adopted to track any tiny deformation of free surface, where the area compensation is carried out to compensate the nonconservation of mass. Present results indicate that the airflow shear can excite flow cells in the isothermal liquid bridge. The airflow shear induced from the upper disk impulses the convex region of free interface as the airflow shear intensity is increased, which may exceed the breaking limit of liquid bridge. The free surface is transformed from the “S”-shape into the “M”-shape as the airflow shear is induced from the lower disk. For the nonisothermal liquid bridge, the flow cell is dominated by the thermocapillary convection at the hot corner if the airflow shear comes from the hot disk, and another reversed flow cell near the cold disk appears. While the shape of free surface depends on the competition between the thermocapillary force and the shear force when the airflow is induced from the cold disk.


Author(s):  
Shaun Whitley ◽  
Dowon Bae

Abstract Solar-rechargeable redox flow batteries (SRFBs) offer feasible solar energy storage with high flexibility in redox couples and storage capacity. Unlike traditional redox flow batteries, homemade flow cell reactors are commonly used in most solar-rechargeable redox flow batteries integrated with photoelectrochemical devices as it provides high system flexibility. This perspective article discusses current trends of the architectural and material characteristics of state-of-the-art photoelectrochemical flow cells for SRFB applications. Key design aspects and guidelines to build a photoelectrochemical flow cell, considering practical operating conditions, are proposed in this perspective.


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