1,721,271 research outputs found
Magnetophoresis and pseudo diamagnetophoresis of single particles/cells on micromagnetic patterns
No full textIn recent years, magnetophoresis has gained significant advances in precise manipulation of particles/cells for numerous applications including gene sequencing, diagnostic, single cell analysis and separation, which can be achieved using nano/micro scale magnets in microfluidic environment with the help of applied magnetic field. Generally, magetophoresis can be classified as either positive magnetophoresis or negative magnetophoresis depending on the magnetizable property of particles/cells and the surrounding medium. Here, in positive magnetophoresis, the individual magnetic particles are manipulated on the micro-magnetic patterns and in the negative magnetophoresis, the individual non-magnetic particles/cells are manipulated on the magnetic micro-cavity pattern by applying an external magnetic field. The design and fabrication of magnetic and magnetic micro-cavity patterns for logical manipulation of particles/cells are presented.
When the magnetic particles are manipulated under an applied in-plane rotating magnetic fields on the micromagnetic pattern, the behavior of particles on streptavidin/Teflon interface between the colloids and the micromagnet arrays were obtained using the magnetic forces at the phase-locked angles.
Further, the fabrication of on-chip micro-magnets using Ni80Fe20 and Co70Fe30 materials were presented to understand the mobility of superparamagnetic (SPM) particles. The maximum velocity of the particles around the periphery of the micromagnets is determined by the critical frequency, which indicates that the particle enters the phase-slipping regime from the phase-locked regime. The maximum velocity of NiFe micromagnets is approximately 3 times larger than that of CoFe micromagnets measured at the low field regions. Moreover, the maximum velocity of the particles is decreasing with increasing the thickness of Teflon coating on the micromagnets, which is in a good agreement with the variation of the magnetostatic potential energy evaluated numerically from micromagnetic simulations.
Micromagnetic simulations were performed using Mumax3 and Matlab software to calculate the magnetic domains of the patterned micromagnets, local magnetic hysteresis loops on the patterned magnetic surface, magnetic force and potential energies of the particles to understand their transport mechanism on the micromagnetic pathways.
When the non-magnetic particles are manipulated under applied strong magnetic fields on the magnetic micro-cavity pattern, a novel Pseudo diamagnetophoresis concept is introduced in place of negative magnetophoresis. The motion of label free cells are shown by introducing ferrofluids in this concept. Specifically, we develop herein a new approach to obtain independent control and directional manipulation of PsD particles, and label-free cells without needs to know the biomarkers. The logic manipulation is based on geometrical parameters of the magnetic micro-cavity patterns, the size difference of particles/cells, which is conducted in a custom-made biocompatible ferrofluid that retains the viability of cells during experiments. The magnetic micro-cavity tracks can actively switch the particles/cells at the junction which resembles an electrical diode, navigating to different directions and desired locations. The switching efficiency of particles/cells is characterized with various eclipse ratios and at various gaps between the horizontal and vertical patterns of the magnetic micro-cavity junctions. The suitable particle/cell sizes and the geometrical parameters of the magnetic micro-cavity junctions are studied to achieve successful logic manipulation of single particles/cells. This unique approach opens a door for development of label-free cells manipulation with high throughput, efficiency and reliability.prohibitionAbstract………………………………………………………………………………….…. i
Acknowledgments…………………………………………………………………………. iv
Table of Contents………………………………………………….………………………. vi
List of Figures……………………………………………………………….……………… X
Ⅰ. Introduction…………………………………………………………………………1
1.1 Positive magnetophoresis…………………………………………..……………………1
1.1.1 Magnetic manipulation of SPM particles/labeled cells on micro-magnetic patterns………………………………………………..………..……………….6
1.2 Negative magnetophoresis…………………………………………………..…12
1.2.1 Methods of manipulation of PsD particles/label free cells………………………12
1.3 Pseudo diamagnetophoresis: Manipulation of PsD particles/cells on magnetic micro-cavity patterns…………………………………………………………………………….................17
1.4 Thesis objectives and outline……………………………………………………………18
Ⅱ. Experimental methods…………………………………………….…………20
2.1 Materials……………………………………….……………………………..…..….…20
2.2 Micro-magnetic and magnetic micro-cavity pattern fabrication process……………..……………………………………………………………………….21
2.2.1 Photolithography…………………………………………………………………21
2.2.2 Lift-off method……………………………………………………………………23
2.3 Characterization techniques…………………………………………………………….23
2.3.1 Vibrating Sample Magnetometer…………………………………………………23
2.3.2 Scanning Electron Microscope……………………………………………………23
2.3.3 Transmission Electron Microscope………………………………………………..24
2.3.4 Atomic Force Microscope…………………………………………………………25
2.4 Experimental device set-up……………………………………………………………….26
2.4.1 Low magnetic field device………………………………………………………….26
2.4.2 High magnetic field device…………………………………………………………27
2.5 Data Analysis……………………………………………………………………………..27
2.6 Micromagnetic simulations ………………………………………………………………28
Ⅲ. Magnetically driven SPM particles on micro-magnetic disk pattern uisng positive magnetophoresis………………………………………...28
3.1 Manipulation of SPM partilces around full disk micro-magnetic pattern…………………28
3.2 Magnetization properties of SPM particles and magnetic thin filMaster…………………..…31
3.3 Magnetic 3D potential energy landscapes on micro-magnetic disk pattern coated with varied Teflon thickness…………………………………………………………………………...33
3.4 Velocities of SPM particles on varied Teflon thickness………………….……………..34
3.5 Velocities of SPM particles on varied magnetic thin filMaster………………………………36
3.6 Conclusion…………………………………………………………………………….…38
Ⅳ. Magnetically driven PsD particles/cells on magnetic micro-cavity patterns using Pseudo diamagnetophoresis……………………...39
4.1 Introduction……………………………..……………………………….……………….39
4.2 Magnetic force acting on PsD particles/cells suspended in ferrofluids…………………..41
4.3 Water based ferrofluids…………………………………………………………………...42
4.4 Magnetic flux distribution of PsD particle/cell and ferrofluid with varied magnetic susceptibilities under applied fields……………………………………………………………….…43
4.5 Manipulation of PsD particles around full disk magnetic micro-cavity pattern…………45
4.6 Magnetic field strength dependence of PsD particle on varied ferrofluid susceptibilities on magnetic micro-cavity disk pattern………………………………………………………….48
4.7 Independent control and directional manipulation of PsD cancer cell on magnetic micro-cavity disk pattern……………………………………………………………………………..50
4.8 Independent control and directional manipulation of PsD particles on asymmetric magnetic micro-cavity patterns………………………………………………………………………..51
4.9 Local control and switching of PsD particles on magnetic micro-cavity eclipse diode…54
5.0 Separation and local storage of PsD particles and label free cells in apartments………...60
Ⅴ. Simultaneous manipulation and separation of SPM and PsD particles by combining positive magnetophoresis and pseudo diamagnetophoresis……………………………………………………………………………62
5.1 SPM and PsD particles magnetic potential energy locations of magnetic and magnetic micro-cavity patterns…………………………………………………………………………62
5.2 Simultaneous manipulation and separation of SPM and PSD particles on magnetic patterns………………………………………………………………………………………………65
5.3 Conclusion…………………………………………………………………………….…68
References………………………………………………………………………………...…70
Summary and Outlook……………………………………………………………………79
Achievements……………………………………………………………………..………..87
List of conferences attended………………………………………………………………88
List of summer schools attended…………………………………………………………89
Project management…………………………………………..……………………………90
List of Publications………………………………………..………………………………91
List of Patents………………………………………………………………………………92DOCTORdCollectio
A Heart Disease Prediction Model using Logistic Regression By Cleveland DataBase
No full textThe early prognosis of cardiovascular diseases can aid in making decisions to lifestyle changes in high risk patients and in turn reduce their complications. Research has attempted to pinpoint the most influential factors of heart disease as well as accurately predict the overall risk using homogenous data mining techniques. Recent research has delved into amalgamating these techniques using approaches such as hybrid data mining algorithms. This paper proposes a rule based model to compare the accuracies of applying rules to the individual results of logistic regression on the Cleveland Heart Disease Database in order to present an accurate model of predicting heart disease. K. Sandhya Rani | M. Sai Chaitanya | G. Sai Kiran "A Heart Disease Prediction Model using Logistic Regression By Cleveland DataBase" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-3 , April 2018, URL: https://www.ijtsrd.com/papers/ijtsrd11402.pd
Characterization of Superparamagnetic Particles Mobility by On-Chip Micromagnets
No full textWe fabricate on-chip micromagnets using Ni80Fe20 and Co70Fe30 materials for the characterization of mobility of superparamagnetic particles. The maximum velocity of the particles around the periphery of the micromagnets is determined by the critical frequency, which indicates that the particle enters the phase-slipping regime from the phase-locked regime. The maximum velocity of NiFe micromagnets is approximately 3 times larger than that of CoFe micromagnets measured at the low field regions. Moreover, the maximum velocity of the particles is decreasing with increasing the thickness of Teflon coating on the micromagnets, which is in a good agreement with the variation of the magnetostatic potential energy evaluated numerically from micromagnetic simulations. © 2018 IEEE.1
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Studies on Processing and Preservation of Value Added Prodcuts from Black Grapes (Vitis Vinefera L).
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effect of Processing on Quality and Stability of Trans and Trans Free Fat
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Identification of Staphylococcus Species by using Species Specific Primers.
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
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