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Yogesh M. Patel Sanidhya Jain Abhishek Kumar Singh Kedar Khare Sarita Ahlawat Supreet Singh Bahga 《Biomicrofluidics》2020,14(6)
We present design, characterization, and testing of an inexpensive, sheath-flow based microfluidic device for three-dimensional (3D) hydrodynamic focusing of cells in imaging flow cytometry. In contrast to other 3D sheathing devices, our device hydrodynamically focuses the cells in a single-file near the bottom wall of the microchannel that allows imaging cells with high magnification and low working distance objectives, without the need for small device dimensions. The relatively large dimensions of the microchannels enable easy fabrication using less-precise fabrication techniques, and the simplicity of the device design avoids the need for tedious alignment of various layers. We have characterized the performance of the device with 3D numerical simulations and validated these simulations with experiments of hydrodynamic focusing of a fluorescently dyed sample fluid. The simulations show that the width and the height of the 3D focused sample stream can be controlled independently by varying the heights of main and side channels of the device, and the flow rates of sample and sheath fluids. Based on simulations, we also provide useful guidelines for choosing the device dimensions and flow rates for focusing cells of a particular size. Thereafter, we demonstrate the applicability of our device for imaging a large number of RBCs using brightfield microscopy. We also discuss the choice of the region of interest and camera frame rate so as to image each cell individually in our device. The design of our microfluidic device makes it equally applicable for imaging cells of different sizes using various other imaging techniques such as phase-contrast and fluorescence microscopy. 相似文献
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Pushpa Khare 《Resonance》2014,19(5):406-420
The only source of information about the universe is the radiation that we receive from various astronomical sources. This article describes some of the methods used by astronomers to analyze this radiation to unveil the mysteries of the universe. 相似文献
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Infants of 18 and 24 months acquiring English were tested in a preferential looking task on their ability to detect ungrammaticalities caused by manipulating a single function word in sentences. Infants heard grammatical sentences in which the determiner the preceded a target noun, as well as three ungrammatical conditions in which the was either dropped, replaced by a nonsense function word (el), or replaced by an alternate English function word (and). Both the 18- and 24-month-old infants oriented faster and more accurately to a visual target following grammatical sentences. The results suggest that by 18 months of age, infants use their knowledge of determiners in sentence computation and in establishing reference. 相似文献
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Daniella Talmon-Heller Benjamin Z. Kedar 《Al-Masaq: Islam & the Medieval Mediterranean》2005,17(2):165-169
This article retraces the genealogy of a mistaken contention, quoted and requoted by a legion of historians of the Crusades; namely, that Muslim survivors of the 1099 massacre in Jerusalem settled in the al-.(S)āli.(h)iyya suburb of Damascus. Actually, the al-.(S)āli.(h)iyya suburb was established some 60 years after the foundation of the Latin Kingdom of Jerusalem in 1099, by emigrants from Muslim villages in central Palestine, then under Frankish rule. Medieval Muslim sources hold no evidence to the relocation of any Jerusalemites of Damascus in 1099. 相似文献
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Avinash Khare 《Resonance》2013,18(10):885-896
In this article I shall present a brief review of the hundred-year young Bohr model of the atom. In particular, I will first introduce the Thomson and the Rutherford models of atoms, their shortcomings and then discuss in some detail the development of the atomic model by Niels Bohr. Further, I will mention its refinements at the hand of Sommerfeld and also its shortcomings. Finally, I will discuss the implication of this model in the development of quantum mechanics. 相似文献
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Ivo D. Dinov Selvam Palanimalai Ashwini Khare Nicolas Christou 《Teaching Statistics》2018,40(2):64-73
Statistical inference involves drawing scientifically‐based conclusions describing natural processes or observable phenomena from datasets with intrinsic random variation. We designed, implemented, and validated a new portable randomization‐based statistical inference infrastructure ( http://socr.umich.edu/HTML5/Resampling_Webapp ) that blends research‐driven data analytics and interactive learning, and provides a backend computational library for managing large amounts of simulated or user‐provided data. We designed, implemented and validated a new portable randomization‐based statistical inference infrastructure ( http://socr.umich.edu/HTML5/Resampling_Webapp ) that blends research‐driven data analytics and interactive learning, and provides a backend computational library for managing large amounts of simulated or user‐provided data. The core of this framework is a modern randomization webapp, which may be invoked on any device supporting a JavaScript‐enabled web browser. We demonstrate the use of these resources to analyse proportion, mean and other statistics using simulated (virtual experiments) and observed (e.g. Acute Myocardial Infarction, Job Rankings) data. Finally, we draw parallels between parametric inference methods and their distribution‐free alternatives. The Randomization and Resampling webapp can be used for data analytics, as well as for formal, in‐class and informal, out‐of‐the‐classroom learning and teaching of different scientific concepts. Such concepts include sampling, random variation, computational statistical inference and data‐driven analytics. The entire scientific community may utilize, test, expand, modify or embed these resources (data, source‐code, learning activity, webapp) without any restrictions. 相似文献
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Measuring forces applied by multi-cellular organisms is valuable in investigating biomechanics of their locomotion. Several technologies have been developed to measure such forces, for example, strain gauges, micro-machined sensors, and calibrated cantilevers. We introduce an innovative combination of techniques as a high throughput screening tool to assess forces applied by multiple genetic model organisms. First, we fabricated colored Polydimethylsiloxane (PDMS) micropillars where the color enhances contrast making it easier to detect and track pillar displacement driven by the organism. Second, we developed a semi-automated graphical user interface to analyze the images for pillar displacement, thus reducing the analysis time for each animal to minutes. The addition of color reduced the Young''s modulus of PDMS. Therefore, the dye-PDMS composite was characterized using Yeoh''s hyperelastic model and the pillars were calibrated using a silicon based force sensor. We used our device to measure forces exerted by wild type and mutant Caenorhabditis elegans moving on an agarose surface. Wild type C. elegans exert an average force of ∼1 μN on an individual pillar and a total average force of ∼7.68 μN. We show that the middle of C. elegans exerts more force than its extremities. We find that C. elegans mutants with defective body wall muscles apply significantly lower force on individual pillars, while mutants defective in sensing externally applied mechanical forces still apply the same average force per pillar compared to wild type animals. Average forces applied per pillar are independent of the length, diameter, or cuticle stiffness of the animal. We also used the device to measure, for the first time, forces applied by Drosophila melanogaster larvae. Peristaltic waves occurred at 0.4 Hz applying an average force of ∼1.58 μN on a single pillar. Our colored microfluidic device along with its displacement tracking software allows us to measure forces applied by multiple model organisms that crawl or slither to travel through their environment. 相似文献
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Avinash Khare 《Resonance》2003,8(8):10-16
I briefly review the seminal 1927 paper of Dirac which emphasized the need for the quantization of the electromagnetic field
and then showed how to carry it out. After mentioning few historical developments, I then point out some of the outstanding
successes of quantum electrodynamics —the kind of agreement which exists between theory and experiment is unprecedented in
the history of science.
Avinash Khare is with the Institute of Physics, Bhubaneswar. His main interests are in the areas of field theory, nonlinear
physics, anyons and supersymmetric quantum mechanics. 相似文献