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Nalupurackal G, Singh J, Roy S, Lokesh M, Chakraborty S, Goswami J, Bhattacharya A, Sinha Mahapatra P, Ganesan AR, Roy B. Estimation of the proximal temperature rise of an excited upconversion particle by detecting the wavefront of emission. Opt Express 2024; 32:6011-6024. [PMID: 38439314 DOI: 10.1364/oe.514938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/04/2024] [Indexed: 03/06/2024]
Abstract
Monitoring the temperature distribution within a local environment at the micro and nanoscale is vital as many processes are solely thermal. Various thermometric techniques have been explored in the community, and out of these, fluorescent nano/micro particle-based mechanisms are accepted widely (fluorescence intensity ratio (FIR) techniques, where the ratio of populations in two consecutive energy levels is compared with Boltzmann distribution). We describe a new technique to account for the temperature rise near an illuminated upconverting particle (UCP) using wavefront imaging, which is more sensitive than the conventional thermometric techniques on the microscale. We rely on a thermo-optical phase microscopic technique by reconstructing the wavefront of emission from an upconverting particle using a Shack-Hartmann wavefront sensor. The wavefront maps the local phase distribution, which is an indicator of the surroundings' optical parameters, particularly the suspended medium's temperature-induced refractive index in the presence of convection currents. We describe how these extracted phase values can provide information about the optical heating due to the particle and hence its local environment along the direction of the emission. Our findings demonstrate the detection of a minimum temperature rise of 0.23 K, while the FIR methods indicate a minimum of 0.3 K rise. This technique is used to study the temperature increase in the backscattered direction for an upconverting particle illuminated on pump resonance. We also estimate the Soret coefficient for an upconverting particle optically trapped on pump resonance and experiencing anisotropic heating across the body.
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Goswami J, Nalupurackal G, Lokesh M, Roy S, Chakraborty S, Bhattacharya A, Mahapatra PS, Roy B. Formation of Two-Dimensional Magnetically Responsive Clusters Using Hematite Particles Self-Assembled via Particle-Induced Heating at an Interface. J Phys Chem B 2023; 127:8487-8495. [PMID: 37733383 DOI: 10.1021/acs.jpcb.3c02229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Hematite particles, which exhibit a high magnetic moment, are used to apply large forces on physical and biological systems under magnetic fields to investigate various phenomena, such as those of rheology and micromanipulation. However, the magnetic confinement of these particles requires complicated field configurations. On the other hand, laser-assisted optical confinement of single hematite particles results in thermophoresis and subsequent ejection of the particle from the laser spot. Herein, we explore an alternative strategy to induce the self-assembly of hematite. In this strategy, with indirect influence from an optically confined and heated upconverting particle (UCP) at an air-water interface, there is the generation of convection currents that facilitate assembly. We also show that the assembly remains at the interface even after removal of the laser light. The hematite particle assemblies can then be moved using magnetic fields and employed to perform interfacial rheology.
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Affiliation(s)
- Jayesh Goswami
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-Group, IIT Madras, Chennai 600036, India
| | - Gokul Nalupurackal
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-Group, IIT Madras, Chennai 600036, India
| | - Muruga Lokesh
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-Group, IIT Madras, Chennai 600036, India
| | - Srestha Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-Group, IIT Madras, Chennai 600036, India
| | - Snigdhadev Chakraborty
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-Group, IIT Madras, Chennai 600036, India
| | - Arijit Bhattacharya
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Pallab Sinha Mahapatra
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Basudev Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-Group, IIT Madras, Chennai 600036, India
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Nakul U, Roy S, Nalupurackal G, Chakraborty S, Siwach P, Goswami J, Edwina P, Bajpai SK, Singh R, Roy B. Studying fluctuating trajectories of optically confined passive tracers inside cells provides familiar active forces. Biomed Opt Express 2023; 14:5440. [PMID: 37810271 PMCID: PMC7615170 DOI: 10.1364/boe.499990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/14/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023]
Abstract
In recent years, there has been a growing interest in studying the trajectories of microparticles inside living cells. Among other things, such studies are useful in understanding the spatio-temporal properties of a cell. In this work, we study the stochastic trajectories of a passive microparticle inside a cell using experiments and theory. Our theory is based on modeling the microparticle inside a cell as an active particle in a viscoelastic medium. The activity is included in our model from an additional stochastic term with non-zero persistence in the Langevin equation describing the dynamics of the microparticle. Using this model, we are able to predict the power spectral density (PSD) measured in the experiment and compute active forces. This caters to the situation where a tracer particle is optically confined and then yields a PSD for positional fluctuations. The low frequency part of the PSD yields information about the active forces that the particle feels. The fit to the model extracts such active force. Thus, we can conclude that trapping the particle does not affect the values of the forces extracted from the active fits if accounted for appropriately by proper theoretical models. In addition, the fit also provides system properties and optical tweezers trap stiffness.
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Affiliation(s)
- Urvashi Nakul
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Srestha Roy
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Gokul Nalupurackal
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Snigdhadev Chakraborty
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Priyanka Siwach
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Jayesh Goswami
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Privita Edwina
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
- Department of Applied Mechanics, IIT Madras, Chennai 600036, India
| | | | - Rajesh Singh
- Department of Physics, IIT Madras, Chennai 600036, India
| | - Basudev Roy
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
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Nalupurackal G, Panja K, Chakraborty S, Roy S, Goswami J, Roy B, Singh R. Controlled roll rotation of a microparticle in a hydro-thermophoretic trap. Phys Rev Res 2023; 5:033005. [PMID: 37675386 PMCID: PMC7615027 DOI: 10.1103/physrevresearch.5.033005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
In recent years, there has been a growing interest in controlling the motion of microparticles inside and outside a focused laser beam. A hydro-thermophoretic trap was recently reported [Nalupurackal et al., Soft Matter 18, 6825 (2022)], which can trap and manipulate microparticles and living cells outside a laser beam. Briefly, a hydro-thermophoretic trap works by the competition between thermoplasmonic flows due to laser heating of a substrate and thermophoresis away from the hotspot of the laser. Here, we extend that work to demonstrate the controlled roll rotation of a microparticle in a hydro-thermophoretic trap using experiments and theory. We experimentally measure the roll angular velocity of the trapped particle. We predict this roll rotation from theoretical computation of the fluid flow. The expression for the angular velocity fits the experimental data. Our method has potential applications in microrheology by employing a different mode of rotation.
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Affiliation(s)
- Gokul Nalupurackal
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Kingshuk Panja
- Department of Physics, IIT Madras, Chennai 600036, India
| | - Snigdhadev Chakraborty
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Srestha Roy
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Jayesh Goswami
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Basudev Roy
- Department of Physics, Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), IIT Madras, Chennai 600036, India
| | - Rajesh Singh
- Department of Physics, IIT Madras, Chennai 600036, India
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Roy S, Vaippully R, Lokesh M, Nalupurackal G, Yadav V, Chakraborty S, Gopalakrishnan M, Edwin PERG, Bajpai SK, Roy B. Comparison of thermal and athermal dynamics of the cell membrane slope fluctuations in the presence and absence of Latrunculin-B. Phys Biol 2023; 20. [PMID: 37080214 PMCID: PMC7614533 DOI: 10.1088/1478-3975/accef1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 04/20/2023] [Indexed: 04/22/2023]
Abstract
Conventionally, only the normal cell membrane fluctuations have been studied and used to ascertain membrane properties like the bending rigidity. A new concept, the membrane local slope fluctuations was introduced recently[Vaippully, et al. Soft Matter 16, 7606 (2020)], which can be modelled as a gradient of the normal fluctuations. It has been found that the Power Spectral Density (PSD) of slope fluctuations behave as (frequency)$^{-1}$ while the normal fluctuations yields (frequency)$^{-5/3}$ even on the apical cell membrane in the high frequency region. In this manuscript, we explore a different situation where the cell is applied with the drug Latrunculin-B which inhibits actin polymerization and find the effect on membrane fluctuations. We find that even as the normal fluctuations show a power law (frequency)$^{-5/3}$ as is the case for a free membrane, the slope fluctuations PSD remains (frequency)$^{-1}$, with exactly the same coefficient as the case when the drug was not applied. Moreover, while sometimes, when the normal fluctuations at high frequency yield a power law of (frequency)$^{-4/3}$, the pitch PSD still yields (frequency)$^{-1}$. Thus, this presents a convenient opportunity to study membrane parameters like bending rigidity as a function of time after application of the drug, while the membrane softens. We also investigate the active athermal fluctuations of the membrane appearing in the PSD at low frequencies and find active timescales of slower than 1 sec.
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Affiliation(s)
- Srestha Roy
- Indian Institute of Technology Madras, Department of Physics, IIT Madras, Chennai, Chennai, Tamil Nadu, 600036, INDIA
| | - Rahul Vaippully
- Physics, Indian Institute of Technology Madras, room no 1064, Krishna Hostel, IIT Madras, Chennai, Tamilnadu, 600036, INDIA
| | - Muruga Lokesh
- Department of Physics, Indian Institute of Technology Madras, Indian Institute of Technology Madras, Chennai, 600036, INDIA
| | - Gokul Nalupurackal
- Indian Institute of Technology Madras, Department of Physics, IIT Madras, Chennai, Chennai, Tamil Nadu, 600036, INDIA
| | - Vandana Yadav
- Physics, Indian Institute of Technology Madras, HSB-234, Department of Physics, Chennai, 600036, INDIA
| | | | - Manoj Gopalakrishnan
- Physics, Indian Institute of Technology Madras, Indian Institute of Technology Madras, Chennai, 600036, INDIA
| | | | - Saumendra Kumar Bajpai
- Applied Mechanics, Indian Institute of Technology Madras, MSB225, Chennai, 600036, INDIA
| | - Basudev Roy
- Physics, Indian Institute of Technology Madras, dept of physics, iit madras, dept of physics, iit madras, chennai, tamil nadu, 600036, INDIA
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Lokesh M, Nalupurackal G, Roy S, Chakraborty S, Goswami J, Gunaseelan M, Chowdhury IU, Bhallamudi VP, Sinha Mahapatra P, Roy B. Accelerated self assembly of particles at the air-water interface with optically assisted heating due to an upconverting particle. Opt Express 2023; 31:5075-5086. [PMID: 36785459 DOI: 10.1364/oe.481722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Abstract
Particles can be assembled at the air-water interface due to optically induced local heating. This induces convection currents in the water which brings particles to the surface. We improve the technique by employing an upconverting particle (UCP), which, when illuminated with 975 nm light, not only emits visible emission but also generates heat owing to the poor efficiency of the upconversion process. This induces strong convection currents which makes particles dispersed in the suspension assemble at the interface and immediately under the UCP. We show assembly of polystyrene particles of 1 μm diameter and diamonds of 500 nm diameter bearing Nitrogen-Vacancy (NV) centers around the UCP. We also show, for the first time, that the microdiamonds are assembled within about 30 nm at the bottom of the UCP by utilizing non-radiative energy transfer that reduces the lifetime of the 550 nm emission from about 90 μs to about 50 μs.
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Roy S, Vaippully R, Lokesh M, Nalupurackal G, Edwina P, Bajpai S, Roy B. Comparison of translational and rotational modes towards passive rheology of the cytoplasm of MCF-7 cells using optical tweezers. Front Phys 2023; 10:1099958. [PMID: 36685106 PMCID: PMC7614090 DOI: 10.3389/fphy.2022.1099958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
A colloidal particle placed inside the cell cytoplasm is enmeshed within a network of cytoskeletal fibres immersed in the cytosolic fluid. The translational mode is believed to yield different rheological parameters than the rotational mode, given that these modes stretch the fibers differently. We compare the parameters for Michigan Cancer Foundation-7 (MCF-7) cells in this manuscript and find that the results are well comparable to each other. At low values of 0 Hz viscosity, the rotational and translational viscoelasticity matches well. However, discrepancies appear at higher values which may indicate that the cytoskeletal modes involved in rotation and translation of the particle are getting invoked. We also show that the 0 Hz viscosity increases as the cell ages under the conditions of constant room temperature of 25°C on the sample chamber.
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Affiliation(s)
- Srestha Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Rahul Vaippully
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Muruga Lokesh
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Gokul Nalupurackal
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Privita Edwina
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Saumendra Bajpai
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
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Edwin PERG, Kumar S, Roy S, Roy B, Bajpai SK. Anisotropic 3D confinement of MCF-7 cells induces directed cell-migration and viscoelastic anisotropy of cell-membrane. Phys Biol 2023; 20. [DOI: 10.1088/1478-3975/ac9bc1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Tumor-associated collagen signature-3 (TACS-3) is a prognostic indicator for breast cancer survival. It is characterized by highly organized, parallel bundles of collagen fibers oriented perpendicular to the tumor boundary, serving as directional, confining channels for cancer cell invasion. Here we design a TACS-3-mimetic anisotropic, confined collagen I matrix and examine the relation between anisotropy of matrix, directed cellular migration, and anisotropy of cell membrane-the first direct contact between TACS-3 and cell-using Michigan Cancer Foundation-7 (MCF-7) cells as cancer-model. Using unidirectional freezing, we generated ∼50 μm-wide channels filled with collagen I. Optical tweezer (OT) microrheology shows that anisotropic confinement increases collagen viscoelasticity by two orders of magnitude, and the elastic modulus is significantly greater along the direction of anisotropic confinement compared to that along the orthogonal direction, thus establishing matrix anisotropy. Furthermore, MCF-7 cells embedded in anisotropic collagen I, exhibit directionality in cellular morphology and migration. Finally, using customized OT to trap polystyrene probes bound to cell-membrane (and not to ECM) of either free cells or cells under anisotropic confinement, we quantified the effect of matrix anisotropy on membrane viscoelasticity, both in-plane and out-of-plane, vis-à-vis the membrane. Both bulk and viscous modulus of cell-membrane of MCF-7 cells exhibit significant anisotropy under anisotropic confinement. Moreover, the cell membrane of MCF-7 cells under anisotropic confinement is significantly softer (both in-plane and out-of-plane moduli) despite their local environment being five times stiffer than free cells. In order to test if the coupling between anisotropy of extracellular matrix and anisotropy of cell-membrane is regulated by cell-cytoskeleton, actin cytoskeleton was depolymerized for both free and confined cells. Results show that cell membrane viscoelasticity of confined MCF-7 cells is unaffected by actin de-polymerization, in contrast to free cells. Together, these findings suggest that anisotropy of ECM induces directed migration and correlates with anisotropy of cell-membrane viscoelasticity of the MCF-7 cells in an actin-independent manner.
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Nalupurackal G, Gunaseelan M, Roy S, Lokesh M, Kumar S, Vaippully R, Singh R, Roy B. A hydro-thermophoretic trap for microparticles near a gold-coated substrate. Soft Matter 2022; 18:6825-6835. [PMID: 36040245 PMCID: PMC7613615 DOI: 10.1039/d2sm00627h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Optical tweezers have revolutionised micromanipulation from physics and biology to material science. However, the high laser power involved in optical trapping can damage biological samples. In this context, indirect trapping of microparticles and objects using fluid flow fields has assumed great importance. It has recently been shown that cells and particles can be turned in the pitch sense by opto-plasmonic heating of a gold surface constituting one side of a sample chamber. We extend that work to place two such hotspots in close proximity to each other to form a very unique configuration of flow fields forming an effective quasi-three-dimensional 'trap', assisted by thermophoresis. This is effectively a harmonic trap confining particles in all three dimensions without relying on other factors to confine the particles close to the surface. We use this to show indirect trapping of different types of upconverting particles and cells, and also show that we can approach a trap stiffness of 40 fN μm-1 indicating a weak confinement regime without relying on feedback.
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Affiliation(s)
- Gokul Nalupurackal
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, IIT Madras, Chennai 600036, India.
| | - M Gunaseelan
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, IIT Madras, Chennai 600036, India.
| | - Srestha Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, IIT Madras, Chennai 600036, India.
| | - Muruga Lokesh
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, IIT Madras, Chennai 600036, India.
| | - Sumeet Kumar
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, IIT Madras, Chennai 600036, India.
| | - Rahul Vaippully
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, IIT Madras, Chennai 600036, India.
| | - Rajesh Singh
- Department of Physics, IIT Madras, Chennai 600036, India.
| | - Basudev Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, IIT Madras, Chennai 600036, India.
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Lokesh M, Nalupurackal G, Roy S, Chakraborty S, Goswami J, Gunaseelan M, Roy B. Generation of partial roll rotation in a hexagonal NaYF 4 particle by switching between different optical trapping configurations. Opt Express 2022; 30:28325-28334. [PMID: 35919192 PMCID: PMC7613164 DOI: 10.1364/oe.462932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Typically a rigid body can have three degrees of rotational freedom. Among these, there can be two types of out-of-plane rotational modes, called the pitch and the roll. The pitch motion is typically to turn the particle along an axis orthogonal to the axis of symmetry. However, rotation about the axis of symmetry (called the roll motion) has so far not been shown in optical tweezers. It is here that we use a hexagonal shaped particle (NaYF4) which prefers to align side on with the optical tweezers [Rodriguez-Sevilla et al., Nano Letters 16, 8005 (2016)]. In this work, we find that the stable configuration of the hexagonal particle changes while using one beam and two beams, so that when one of the tweezers beams is switched on and off, the particle tends to switch between the different configurations. Thus we get a controlled roll motion. This is the first time that controlled partial roll motions have been generated in optical tweezers.
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Chakraborty S, Nalupurackal G, Gunaseelan M, Roy S, Lokesh M, Goswami J, Datta P, Mahapatra PS, Roy B. Facets of optically and magnetically induced heating in ferromagnetically doped-NaYF 4 particles. J Phys Commun 2022; 7:065008. [PMID: 37398924 PMCID: PMC7614712 DOI: 10.1088/2399-6528/acde43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Upconverting particles like Yb and Er-doped NaYF4 are known to heat up after illumination with light at pump wavelength due to inefficient upconversion processes. Here we show that NaYF4 particles which have been co-doped not only with Yb and Er but also Fe improves the photothermal conversion efficiency. In addition, we show for the first time that alternating magnetic fields also heat up the ferromagnetic particles. Thereafter we show that a combination of optical and magnetic stimuli significantly increases the heat generated by the particles.
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Affiliation(s)
- Snigdhadev Chakraborty
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Gokul Nalupurackal
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - M Gunaseelan
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
- Department of Physics, Rathinam Research Hub, Rathinam College of Arts and Science, Coimbatore, 641021, India
| | - Srestha Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Muruga Lokesh
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Jayesh Goswami
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Priyankan Datta
- Department of Mechanical engineering, Indian Institute of Technology Madras, India
| | | | - Basudev Roy
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India
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Jose M, Lokesh M, Vaippully R, Satapathy DK, Roy B. Temporal evolution of viscoelasticity of soft colloid laden air-water interface: a multiple mode microrheology study. RSC Adv 2022; 12:12988-12996. [PMID: 35497011 PMCID: PMC9049755 DOI: 10.1039/d2ra00765g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 04/19/2022] [Indexed: 12/17/2022] Open
Abstract
Mechanical properties of particle laden interfaces is crucial for various applications. For water droplets containing soft microgel particles, passive microrheology studies have revealed that the dynamically varying surface area of the evaporating drop results in a viscous to viscoelastic transition along the plane of the interface. However, the behaviour of the medium orthogonal to the interface has been elusive to study using passive microrheology techniques. In this work, we employ optical tweezers and birefringent probe particles to extract the direction-resolved viscoelastic properties of the particle-laden interface. By using special types of birefringent tracer particles, we detect not only the in-plane translational mode but also the out-of-plane translational (perpendicular to the interface) and rotational modes. We first compare different passive methods of probing the viscoelasticity of the microgel laden interface of sessile drop and then study the modes perpendicular to the interface and the out-of-plane rotational mode using optical tweezers based passive microrheology. The viscoelasticity of the interface using two different methods, i.e., multiple-particle tracking passive microrheology using video microscopy and by trapping birefringent tracer particles in optical tweezers, relying on different models are studied and found to exhibit comparable trends. Interestingly, the mode orthogonal to the interface and the rotational mode also show the viscous to viscoelastic transition as the droplet evaporates, but with lesser viscoelasticity during the same evaporation time than the in-plane mode.
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Affiliation(s)
- Merin Jose
- Department of Physics, Indian Institute of Technology Madras Chennai Tamil Nadu India 600036
| | - Muruga Lokesh
- Department of Physics, Indian Institute of Technology Madras Chennai Tamil Nadu India 600036
| | - Rahul Vaippully
- Department of Physics, Indian Institute of Technology Madras Chennai Tamil Nadu India 600036
| | - Dillip K Satapathy
- Department of Physics, Indian Institute of Technology Madras Chennai Tamil Nadu India 600036
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras Chennai Tamil Nadu India 600036
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13
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Birchall D, Hosdon K, Roy B. Shoulder stabilisation surgery: Exploring patient satisfaction and barriers to physiotherapy engagement. Physiotherapy 2022. [DOI: 10.1016/j.physio.2021.12.221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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Yamini S, Gunaseelan M, Gangadharan A, Lopez SA, Martirosyan KS, Girigoswami A, Roy B, Manonmani J, Jayaraman S. Upconversion, MRI imaging and optical trapping studies of silver nanoparticle decorated multifunctional NaGdF4:Yb,Er nanocomposite. Nanotechnology 2021; 33. [PMID: 34753112 DOI: 10.1088/1361-6528/ac37e4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/09/2021] [Indexed: 05/16/2023]
Abstract
The multifunctional upconversion nanoparticles (UCNPs) are fascinating tool for biological applications. In the present work, photon upconverting NaGdF4:Yb,Er and Ag nanoparticles decorated NaGdF4:Yb,Er (NaGdF4:Yb,Er@Ag) nanoparticles were prepared using a simple polyol process. Rietveld refinement was performed for detailed crystal structural and phase fraction analysis. The morphology of the NaGdF4:Yb,Er@Ag was examined using high-resolution transmission electron microscope, which reveals silver nanoparticles of 8 nm in size were decorated over spherical shaped NaGdF4:Yb,Er nanoparticles with a mean particle size of 90 nm. The chemical compositions were confirmed by EDAX and inductively coupled plasma-optical emission spectrometry analyses. The upconversion luminescence (UCL) of NaGdF4:Yb,Er at 980 nm excitation showed an intense red emission. After incorporating the silver nanoparticles, the UCL intensity decreased due to weak scattering and surface plasmon resonance effect. The VSM magnetic measurement indicates both the UCNPs possess paramagnetic behaviour. The NaGdF4:Yb,Er@Ag showed computed tomography imaging. Magnetic resonance imaging study exhibited better T1 weighted relaxivity in the NaGdF4:Yb,Er than the commercial Gd-DOTA. For the first time, the optical trapping was successfully demonstrated for the upconversion NaGdF4:Yb,Er nanoparticle at near-infrared 980 nm light using an optical tweezer setup. The optically trapped UCNP possessing paramagnetic property exhibited a good optical trapping stiffness. The UCL of trapped single UCNP is recorded to explore the effect of the silver nanoparticles. The multifunctional properties for the NaGdF4:Yb,Er@Ag nanoparticle are demonstrated.
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Affiliation(s)
- S Yamini
- Department of Nuclear Physics, University of Madras, Chennai 600 025, Tamil Nadu, India
| | - M Gunaseelan
- Department of Nuclear Physics, University of Madras, Chennai 600 025, Tamil Nadu, India
- Department of Physics, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India
| | - Ajithkumar Gangadharan
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, United States of America
- Department of Atomic and Molecular Physics, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Silverio A Lopez
- Department of Physics and Astronomy, The University of Texas Rio Grande Valley, 1201 W University Blvd, Brownsville, TX, 78520, United States of America
| | - Karen S Martirosyan
- Department of Physics and Astronomy, The University of Texas Rio Grande Valley, 1201 W University Blvd, Brownsville, TX, 78520, United States of America
| | - Agnishwar Girigoswami
- Faculty of Allied Health Sciences, Chettinad Academy of Research & Education, Kelambakkam, Tamil Nadu, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India
| | - J Manonmani
- Department of Chemistry, Quaid-E-Millath Government College for Women (Autonomous), Chennai 600 002, Tamil Nadu, India
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15
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Lokesh M, Vaippully R, Bhallamudi VP, Prabhakar A, Roy B. Realization of pitch-rotational torque wrench in two-beam optical tweezers. J Phys Commun 2021; 5:115016. [PMID: 34869919 PMCID: PMC7612066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
3D Pitch (out-of-plane) rotational motion has been generated in spherical particles by maneuvering the laser spots of holographic optical tweezers. However, since the spherical particles, which are required to minimise drag are perfectly isotropic, a controllable torque cannot be applied with it. It remains free to spin about any axis even after moving the tweezers beams. It is here that we trap birefringent particles of about 3 μm diameter in two tweezers beams and then change the depth of one of the beam foci controllably to generate a pitch rotational torque-wrench and avoid the free spinning of the particle. We also detect the rotation with newly developed pitch motion detection technique and apply controlled torques on the particle.
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Affiliation(s)
- Muruga Lokesh
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Rahul Vaippully
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Vidya P Bhallamudi
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Anil Prabhakar
- Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
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16
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Lokesh M, Vaippully R, Nalupurackal G, Roy S, Bhallamudi VP, Prabhakar A, Roy B. Estimation of rolling work of adhesion at the nanoscale with soft probing using optical tweezers. RSC Adv 2021; 11:34636-34642. [PMID: 34737851 PMCID: PMC8546490 DOI: 10.1039/d1ra06960h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/19/2021] [Indexed: 12/23/2022] Open
Abstract
Conventionally, the work of adhesion at the nanoscale is estimated using an atomic force microscope with a tip of the size of 10 nm. It is pressed into a surface with nano-Newton forces and then retracted to ascertain when the tip breaks away from the surface. Thus this ensures "hard probing" of a surface. However there can be another configuration where the particle is barely placed into the surface when the work of adhesion attaches the particle to the surface and this can be called "soft probing". In this configuration, if a birefringent particle is confined in linearly polarized optical tweezers, and then the surface is moved in the direction tangential to the plane, a rolling motion can be induced. Study of this rolling motion can also show the work of adhesion. We use this configuration to find the rolling work of adhesion of a 3 μm diameter birefringent particle on a glass surface. We go on to study the effects of changing the surface to a hydrophobic slippery surface like polydimethyl siloxane (PDMS). Then we go on to show that even 500 nm diameter diamonds bearing nitrogen vacancy (NV) centers which are birefringent due to the stresses on the crystal could also be trapped and rolled to generate pitch (out-of-plane rotation) motion with 50 nm contact diameters. We find that this mode of soft probing yields a work of adhesion of about 1 mJ m-2 while the conventional nanoscale probing with atomic force microscopes (AFM) yields about 50 mJ m-2.
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Affiliation(s)
- Muruga Lokesh
- Department of Physics, Indian Institute of Technology MadrasChennai600036India
| | - Rahul Vaippully
- Department of Physics, Indian Institute of Technology MadrasChennai600036India
| | - Gokul Nalupurackal
- Department of Physics, Indian Institute of Technology MadrasChennai600036India
| | - Srestha Roy
- Department of Physics, Indian Institute of Technology MadrasChennai600036India
| | - Vidya P. Bhallamudi
- Department of Physics, Indian Institute of Technology MadrasChennai600036India
| | - Anil Prabhakar
- Department of Electrical Engineering, Indian Institute of Technology MadrasChennai600036India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology MadrasChennai600036India
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17
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Vaibavi SR, Sivasubramaniapandian M, Vaippully R, Edwina P, Roy B, Bajpai SK. Calcium-channel-blockers exhibit divergent regulation of cancer extravasation through the mechanical properties of cancer cells and underlying vascular endothelial cells. Cell Biochem Biophys 2021; 80:171-190. [PMID: 34643835 DOI: 10.1007/s12013-021-01035-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 09/24/2021] [Indexed: 11/26/2022]
Abstract
Cardiovascular and cancer illnesses often co-exist, share pathological pathways, and complicate therapy. In the context of the potential oncological role of cardiovascular-antihypertensive drugs (AHD), here we examine the role of calcium-channel blocking drugs on mechanics of extravasating cancer cells, choosing two clinically-approved calcium-channel blockers (CCB): Verapamil-hydrochloride and Nifedipine, as model AHD to simultaneously target cancer cells (MCF7 and or MDA231) and an underlying monolayer of endothelial cells (HUVEC). First, live-cell microscopy shows that exposure to Nifedipine increases the spreading-area, migration-distance, and frequency of transmigration of MCF-7 cells through the HUVEC monolayer, whereas Verapamil has the opposite effect. Next, impedance-spectroscopy shows that for monolayers of either endothelial or cancer cells, Nifedipine-treatment alone decreases the impedance of both cases, suggesting compromised cell-cell integrity. Furthermore, upon co-culturing MCF-7 on the HUVEC monolayers, Nifedipine-treated MCF-7 cells exhibit weaker impedance than Verapamil-treated MCF-7 cells. Following, fluorescent staining of CCB-treated cytoskeleton, focal adhesions, and cell-cell junction also indicated that Nifedipine treatment diminished the cell-cell integrity, whereas verapamil treatment preserved the integrity. Since CCBs regulate intracellular Ca2+, we next investigated if cancer cell's exposure to CCBs regulates calcium-dependent processes critical to extravasation, specifically traction and mechanics of plasma membrane. Towards this end, first, we quantified the 2D-cellular traction of cells in response to CCBs. Results show that exposure to F-actin depolymerizing drug decreases traction stress significantly only for Nifedipine-treated cells, suggesting an actin-independent mechanism of Verapamil activity. Next, using an optical tweezer to quantify the mechanics of plasma membrane (PM), we observe that under constant, externally-applied tensile strain, PM of Nifedipine-treated cells exhibits smaller relaxation-time than Verapamil and untreated cells. Finally, actin depolymerization significantly decreases MSD only for Verapamil treated cancer-cells and endothelial cells and not for Nifedipine-treated cells. Together, our results show that CCBs can have varied, mechanics-regulating effects on cancer-cell transmigration across endothelial monolayers. A judicious choice of CCBs is critical to minimizing the pro-metastatic effects of antihypertension therapy.
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Affiliation(s)
- S R Vaibavi
- Department of Applied Mechanics, Indian Institute of Technology, Madras, India
| | | | - Rahul Vaippully
- Department of Physics, Indian Institute of Technology, Madras, India
| | - Privita Edwina
- Department of Applied Mechanics, Indian Institute of Technology, Madras, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology, Madras, India
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18
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Korb M, Peck A, Berger K, James M, Ghoshal N, Healzer E, Henchcliffe C, Khan S, Mammen P, Patel S, Pfeffer G, Ralston S, Roy B, Seeley B, Swenson A, Mozaffar T, Weihl C, Kimonis V, Alfano L. REGISTRIES AND CARE OF NMD. Neuromuscul Disord 2021. [DOI: 10.1016/j.nmd.2021.07.372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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19
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Das G, Hajra DK, Mukherjee RD, Hembram S, Roy B. Sustainable income generation of the farmers through pig farming: A case study in Terai region of West Bengal. Journal of Livestock Science 2021. [DOI: 10.33259/jlivestsci.2021.241-245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Kumar S, M G, Vaippully R, Banerjee A, Roy B. Breaking the diffraction limit in absorption spectroscopy using upconverting nanoparticles. Nanoscale 2021; 13:11856-11866. [PMID: 34190292 PMCID: PMC7611605 DOI: 10.1039/d1nr02103f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We employ a single optically trapped upconverting nanoparticle (UCNP) of NaYF4:Yb,Er of diameter about 100 nm as a subdiffractive source to perform absorption spectroscopy. The experimentally expected mode volume of 100 nm of the backscatter profile of the nanoparticle matches well with a numerical simulation of the dominant backscattering modes to confirm our assertion of achieving a source dimension considerably lower than the diffraction limit set by the excitation wavelength of 975 nm for the UCNP. We perform absorption spectroscopy of several diverse entities such as the dye Rhodamine B in water, a thin gold film of thickness 30 nm, and crystalline soft oxometalates micro-patterned on a glass substrate using the UCNP as a source. The initial results lead to unambiguous utility of UCNPs as single nanoscopic sources for absorption spectroscopy of ultra-small sample volumes (femtolitres), and lead us to hypothesize a possible Resonance Energy Transfer mechanism between the UCNP and the molecules of the ambient medium, which may even lead to single molecule absorption spectroscopy applications.
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Affiliation(s)
- Sumeet Kumar
- Department of Physics, Quantum Centres in Diamond and Emergent Materials (QuCenDiEM)-group, Micro Nano and Bio-Fluidics (MNBF)-Group, Indian Institute of Technology Madras, Chennai, 600036, India.
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21
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Roy B, Walker K, Morgan C, Finch-Edmondson M, Galea C, Epi M, Badawi N, Novak I. Epidemiology and pathogenesis of stroke in preterm infants: A systematic review. J Neonatal Perinatal Med 2021; 15:11-18. [PMID: 34219672 PMCID: PMC8842753 DOI: 10.3233/npm-200597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: Perinatal stroke is one of the principal causes of cerebral palsy (CP) in preterm infants. Stroke in preterm infants is different from stroke in term infants, given the differences in brain maturation and the mechanisms of injury exclusive to the immature brain. We conducted a systematic review to explore the epidemiology and pathogenesis of periventricular hemorrhagic infarction (PVHI), perinatal arterial ischemic stroke (PAIS) and cerebral sinovenous thrombosis (CSVT) in preterm infants. METHODS: Studies were identified based on predefined study criteria from MEDLINE, EMBASE, SCOPUS and WEB OF SCIENCE electronic databases from 2000 –2019. Results were combined using descriptive statistics. RESULTS: Fourteen studies encompassed 546 stroke cases in preterm infants between 23 –36 weeks gestational ages and birth weights between 450 –3500 grams. Eighty percent (436/546) of the stroke cases were PVHI, 17%(93/546) were PAIS and 3%(17/546) were CSVT. Parietal PVHI was more common than temporal and frontal lobe PVHI. For PAIS, left middle cerebral artery (MCA) was more common than right MCA or cerebellar stroke. For CSVT partial or complete thrombosis in the transverse sinus was universal. All cases included multiple possible risk factors, but the data were discordant precluding aggregation within a meta-analysis. CONCLUSION: This systematic review confirms paucity of data regarding the etiology and the precise causal pathway of stroke in preterm infants. Moreover, the preterm infants unlike the term infants do not typically present with seizures. Hence high index of clinical suspicion and routine cUS will assist in the timely diagnosis and understanding of stroke in this population.
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Affiliation(s)
- B Roy
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Australia.,School of Medicine, The University of Notre Dame Australia, Sydney, Australia.,The Mater Hospital, Sydney, Australia
| | - K Walker
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Australia.,The George Institute for Global Health, Sydney, Australia.,Newborn Care, Royal Prince Alfred Hospital, Sydney, Australia
| | - C Morgan
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Australia.,Cerebral Palsy Alliance Research Institute, Sydney, Australia
| | - M Finch-Edmondson
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Australia.,Cerebral Palsy Alliance Research Institute, Sydney, Australia
| | - C Galea
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Australia.,Cerebral Palsy Alliance Research Institute, Sydney, Australia
| | | | - N Badawi
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Australia.,Cerebral Palsy Alliance Research Institute, Sydney, Australia.,Grace Centre for Newborn Intensive Care, Sydney Children's Hospital Network, Westmead, Australia
| | - I Novak
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Australia.,Cerebral Palsy Alliance Research Institute, Sydney, Australia
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22
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Ali M, Ahmed K, Hossain H, Roy B, Rokeya B, Rahman M, Jahan I, Rahman M. Total antioxidant capacity and profiling of polyphenolic compounds in jute leaves by HPLC-DAD. Food Res 2021. [DOI: 10.26656/fr.2017.5(1).358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Jute leaves (Corchorus spp.) have been used as a medicinal plant for the treatment of
various diseases. The study was investigated on the antioxidant activities and HPLC
profiling of polyphenolic compounds in ethanol extract of Corchorus olitorius (C.
olitorius) and Corchorus capsularis (C. capsularis) leaves. The total antioxidant capacity
was evaluated by phosphomolybdenum method and Identification and quantification of
polyphenolic compounds were performed using HPLC-DAD system. The results indicated
that eight polyphenolic compounds were found in the C. capsularis leaves but C. olitorius
leaves contain six polyphenolic compounds. In fact, major identified polyphenolic
compounds of C. capsularis leaves were caffeic acid (CA), 55.93±0.13; trans-ferulic acid
(FA), 58.02±0.18; rutin hydrate (RH), 32.16±0.08; ellagic acid (EA), 53.65±0.11 and
quercetin hydrate (QU), 46.17±0.09 mg/100 g of dry extract respectively. Whereas in C.
olitorius leaves which were rutin hydrate (RH), 152.17±0.51; ellagic acid (EA),
143.27±0.58 and quercetin hydrate (QU), 292.83±0.73 mg/100 g of dry extract
respectively. The results showed that C. capsularis leaves contained high level of total
antioxidant capacity (214.32±1.95 mg of ascorbic acid/g of dry extract) than that of C.
olitorius (165.66±1.30 mg of ascorbic acid/g of dry extract) leaves. The overall data
suggested that C. olitorius and C. capsularis leaves contain a significant amount of several
polyphenolic compounds that could be used as a natural antioxidant for functional foods.
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23
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Ghosh S, Ranjan AD, Das S, Sen R, Roy B, Roy S, Banerjee A. Directed Self-Assembly Driven Mesoscale Lithography Using Laser-Induced and Manipulated Microbubbles: Complex Architectures and Diverse Applications. Nano Lett 2021; 21:10-25. [PMID: 33296219 DOI: 10.1021/acs.nanolett.0c03839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A microbubble nucleated due to the absorption of a tightly focused laser at the interface of a liquid-solid substrate enables directed and irreversible self-assembly of mesoscopic particles dispersed in the liquid at the bubble base. This phenomenon has facilitated a new microlithography technique which has grown rapidly over the past decade and can now reliably pattern a vast range of soft materials and colloids, ranging from polymers to metals to proteins. In this review, we discuss the science behind this technology and the present state-of-the-art. Thus, we describe the physics of the self-assembly driven by the bubble, the techniques for generating complex mesoarchitectures, both discrete and continuous, and their properties, and the various applications demonstrated in plastic electronics, site-specific catalysis, and biosensing. Finally, we describe a roadmap for the technique to achieve its potential of successfully patterning "everything" mesoscopic and the challenges that lie therein.
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Affiliation(s)
- Subhrokoli Ghosh
- Light Matter Lab, Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Anand Dev Ranjan
- Light Matter Lab, Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Santu Das
- EFAML, Materials Science Centre, Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Rakesh Sen
- EFAML, Materials Science Centre, Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Soumyajit Roy
- EFAML, Materials Science Centre, Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
| | - Ayan Banerjee
- Light Matter Lab, Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, India
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24
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Acharjee S, Mandal G, Patra A, Debnath B, Roy B. Effects of feeding rice-based dried distillers grains with solubles and condensed distillers solubles on feed intake, milk production and fatty acid composition in lactating crossbred cows. ANIM NUTR FEED TECHN 2021. [DOI: 10.5958/0974-181x.2021.00020.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Vaippully R, Ramanujan V, Gopalakrishnan M, Bajpai S, Roy B. Detection of sub-degree angular fluctuations of the local cell membrane slope using optical tweezers. Soft Matter 2020; 16:7606-7612. [PMID: 32724976 DOI: 10.1039/d0sm00566e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Normal thermal fluctuations of the cell membrane have been studied extensively using high resolution microscopy and focused light, particularly at the peripheral regions of a cell. We use a single probe particle attached non-specifically to the cell-membrane to determine that the power spectral density is proportional to (frequency)-5/3 in the range of 5 Hz to 1 kHz. We also use a new technique to simultaneously ascertain the slope fluctuations of the membrane by relying upon the determination of pitch motion of the birefringent probe particle trapped in linearly polarized optical tweezers. In the process, we also develop the technique to identify pitch rotation to a high resolution using optical tweezers. We find that the power spectrum of slope fluctuations is proportional to (frequency)-1, which we also explain theoretically. We find that we can extract parameters like bending rigidity directly from the coefficient of the power spectrum particularly at high frequencies, instead of being convoluted with other parameters, thereby improving the accuracy of estimation. We anticipate this technique for determination of the pitch angle in spherical particles to high resolution as a starting point for many interesting studies using the optical tweezers.
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Affiliation(s)
- Rahul Vaippully
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - Vaibavi Ramanujan
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Manoj Gopalakrishnan
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - Saumendra Bajpai
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
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26
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Kumar S, Gunaseelan M, Vaippully R, Kumar A, Ajith M, Vaidya G, Dutta S, Roy B. Pitch-rotational manipulation of single cells and particles using single-beam thermo-optical tweezers. Biomed Opt Express 2020; 11:3555-3566. [PMID: 33014551 PMCID: PMC7510922 DOI: 10.1364/boe.392901] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/17/2020] [Accepted: 05/21/2020] [Indexed: 05/28/2023]
Abstract
3D pitch rotation of microparticles and cells assumes importance in a wide variety of applications in biology, physics, chemistry and medicine. Applications such as cell imaging and injection benefit from pitch-rotational manipulation. Generation of such motion in single beam optical tweezers has remained elusive due to the complexities of generating high enough ellipticity perpendicular to the direction of propagation. Further, trapping a perfectly spherical object at two locations and subsequent pitch rotation hasn't yet been demonstrated to be possible. Here, we use hexagonal-shaped upconverting particles and single cells trapped close to a gold-coated glass cover slip in a sample chamber to generate complete 360 degree and continuous pitch motion even with a single optical tweezer beam. The tweezers beam passing through the gold surface is partially absorbed and generates a hot-spot to produce circulatory convective flows in the vicinity which rotates the objects. The rotation rate can be controlled by the intensity of the laser light. Thus such a simple configuration can turn the particle in the pitch sense. The circulatory flows in this technique have a diameter of about 5 μm which is smaller than those reported using acousto-fluidic techniques.
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Affiliation(s)
- Sumeet Kumar
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - M. Gunaseelan
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Rahul Vaippully
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Amrendra Kumar
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Mithun Ajith
- Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Gaurav Vaidya
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Soumya Dutta
- Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
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27
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Roy B, Kovvuru S, Castillo YC, Huttner A, Nowak RJ. Reply to: What is the pattern of the neuropathy associated with anti-FGFR3 antibodies? Eur J Neurol 2020; 27:e59. [PMID: 32503081 DOI: 10.1111/ene.14381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 05/28/2020] [Indexed: 11/29/2022]
Affiliation(s)
- B Roy
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - S Kovvuru
- Department of Neurology, University of Arkansas, Little Rock, AR, USA
| | - Y C Castillo
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - A Huttner
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - R J Nowak
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
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Vaippully R, Ramanujan V, Bajpai S, Roy B. Measurement of viscoelastic properties of the cellular cytoplasm using optically trapped Brownian probes. J Phys Condens Matter 2020; 32:235101. [PMID: 32059195 DOI: 10.1088/1361-648x/ab76ac] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Measurement of the viscoelastic properties of a cell using microscopic tracer particles has been complicated given that the medium viscosity is dependent upon the size of the measurement probe leading to reliability issues. Further, a technique for direct calibration of optically trapped particles in vivo has been elusive due to the frequency dependence and spatial inhomogeneity of the cytoplasmic viscosity, and the requirement of accurate knowledge of the medium refractive index. Here, we employ a recent extension of Jeffery's model of viscoelasticity in the microscopic domain to fit the passive motional power spectra of micrometer-sized optically trapped particles embedded in a viscoelastic medium. We find excellent agreement between the 0 Hz viscosity in MCF7 cells and the typical values of viscosity in literature, between 2 to 16 mPa sec expected for the typical concentration of proteins inside the cytoplasmic solvent. This bypasses the dependence on probe size by relying upon small thermal displacements. Our measurements of the relaxation time also match values reported with magnetic tweezers, at about 0.1 s. Finally, we calibrate the optical tweezers and demonstrate the efficacy of the technique to the study of in vivo translational motion.
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Kovvuru S, Cardenas YC, Huttner A, Nowak RJ, Roy B. Clinical characteristics of fibroblast growth factor receptor 3 antibody-related polyneuropathy: a retrospective study. Eur J Neurol 2020; 27:1310-1318. [PMID: 32068339 DOI: 10.1111/ene.14180] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 02/14/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND PURPOSE Autoantibodies are increasingly being used as a diagnostic biomarker of chronic inflammatory neuropathies. However, their role and associated clinical syndrome are not well defined. METHODS This retrospective chart review evaluated the clinical presentation, diagnostic workup and therapeutic responses in fibroblast growth factor receptor 3 (FGFR3) antibody-associated neuropathy. RESULTS A total of 27 patients [14 men, aged 29-87 (65 ± 14) years] with positive FGFR3 antibody were included. Distal lower-extremity paresthesia (66%), unsteady gait (26%) and foot drop (11%) were common presenting symptoms. Symptom onset was acute in four (15%) cases. Distal lower-extremity weakness (mild in eight and severe in three patients) was the most frequent motor finding. Decreased distal sensation to pinprick (59%) and loss of vibration sensation (37%) were observed. Titer of FGFR3 ranged between 3100 and 30 000 (normal < 3000) with a mean of 10 688 ± 7284. Apart from the occasional association of other neuropathy-related autoantibodies, comprehensive neuropathy workup was otherwise unrevealing. Six patients had other autoimmune disease and seven patients had a history of cancer. Electromyography reflected sensorimotor neuropathy with mixed axonal and demyelinating features in 11 cases. Pure sensory neuropathy was noted in three patients. Demyelination was found in five of six nerve biopsies. Intravenous immunoglobulin response was observed in 8/10 treated patients. CONCLUSIONS The FGFR3 antibody appears not to be restricted to sensory neuropathy only. Its role in the pathogenicity of chronic inflammatory neuropathies is not yet well established and, although there may be a role for immunotherapy, larger studies are warranted.
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Affiliation(s)
- S Kovvuru
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA.,Department of Neurology, University of Arkansas, Little Rock, AR, USA
| | - Y C Cardenas
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - A Huttner
- Department of Pathology, Yale School of Medicine, New Haven, CT, USA
| | - R J Nowak
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - B Roy
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
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Roy B, Tousif Ahamed SK, Bandyopadhyay B, Giri N. Development of quinolone resistance and prevalence of different virulence genes among Shigella flexneri and Shigella dysenteriae in environmental water samples. Lett Appl Microbiol 2020; 71:86-93. [PMID: 31829434 DOI: 10.1111/lam.13262] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/31/2019] [Accepted: 12/06/2019] [Indexed: 12/30/2022]
Abstract
The purpose of this study was to find out the mechanism of quinolone resistance in Shigella sp. isolated from environmental water samples from various parts of Kolkata, India. Out of 196 Shigella sp. isolated from 2014 to 2017, we selected 32 Shigella isolates for antimicrobial susceptibility tests. The minimum inhibitory concentrations (MIC) for quinolones ranged from 30 to 50 μg ml-1 for ofloxacin, 5-20 μg ml-1 for ciprofloxacin and 20-30 μg ml-1 for norfloxacin. A few amino acid changes were found in quinolone resistance determining region (QRDR) of gyrA. Mutations in gyrA lead to a higher increment of MIC of quinolones. Among the plasmid-mediated (PMQR) quinolone resistance genes investigated, qnrB and aac(6')-lb-cr genes were found in all isolates. qnrA and qnrS were found in 25% and 62% of the isolates, respectively. ipaH gene was found in all of the isolates followed by the presence of other virulence genes ial, sen and stx1. Almost all the isolates having high MICs showed efflux pump activity in drug accumulation assay. All the mechanisms may or may not be present in a single strain. Several types of efflux pumps, presence of PMQR genes and mutations in drug target site of QRDR region may play the crucial role for resistance in our isolates.
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Affiliation(s)
- B Roy
- Department of Microbiology, Acharya Prafulla Chandra College, New Barrackpore, Kolkata, India
| | - S K Tousif Ahamed
- Department of Microbiology, Acharya Prafulla Chandra College, New Barrackpore, Kolkata, India
| | - B Bandyopadhyay
- School of Applied Sciences and Languages, VIT Bhopal University, Bhopal, Madhya Pradesh, India
| | - N Giri
- Department of Microbiology, Acharya Prafulla Chandra College, New Barrackpore, Kolkata, India
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31
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Bhatt D, Vaippully R, Kharbanda B, Dev Ranjan A, R S, Dharod V, Satapathy D, Roy B. Detection of self-generated nanowaves on the interface of an evaporating sessile water droplet. Opt Express 2019; 27:31900-31912. [PMID: 31684413 DOI: 10.1364/oe.27.031900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/25/2019] [Indexed: 06/10/2023]
Abstract
Evaporating sessile droplets have been known to exhibit oscillations on the air-liquid interface. These are generally over millimeter scales. Using a novel approach, we are able to measure surface height changes of 500 nm amplitude using optical trapping of a set of microscopic particles at the interface, particularly when the vertical thickness of the droplet reduces to less than 50 μm. We find that at the later stages of the droplet evaporation, particularly when the convection currents become large, the top air-water interface starts to spontaneously oscillate vertically as a function of time in consistency with predictions. We also detect travelling wave trains moving in the azimuthal direction of the drop surface which are consistent with hydrothermal waves at a different combination of Reynolds, Prandtl and Evaporation numbers than previously observed. This is the first time that wave-trains have been observed in water, being extremely challenging to detect both interferometrically and with infra-red cameras. We also find that such waves apply a force parallel to the interface along the propagation direction.
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Chawla T, Thambudorai R, Ashok A, Roy B, Ghosh J, Ganguly S, Roy P, Mallath M. Perioperative chemotherapy with docetaxel, oxaliplatin, fluorouracil and leucovorin (FLOT) versus epirubicin, platinum and capecitabine or flourouracil (EOX/ECF) in resectable gastric or gastroesophageal junction adenocarcinoma: Safety and response data from India. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz247.109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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33
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Woo MA, Roy B, Kumar R. P2257Self-care abilities and depression symptoms linked to brain injury in heart failure. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Heart failure (HF) patients show brain damage in regions controlling mood, autonomic, and cognitive functions. HF patient's exhibit symptoms related to depression, anxiety, poor sleep quality, daytime sleepiness, impaired cognition, and poor self-care, however, the relationship between brain damage and disease related symptoms is unclear. Therefore, our aim was to correlate gray matter density in prefrontal cortices, hippocampus, and insular lobe with disease symptoms using T1-weight voxel based morphometry procedure and evaluate the measure that predicts the brain damage.
Methods
Two high-resolution T1-weighted data were collected from each 42 HF subjects (age, 55.65±7.61; 30 male; LVEF 27.74±9.40%; NYHA class II/III) using a 3.0-Tesla MRI scanner. Depression, anxiety, sleep quality, daytime sleepiness, cognition, and self-care issues were examined with Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Montreal Cognitive Assessment (MoCA), and Self-Care of Heart Failure Inventory (SCHFI) respectively. Both T1-weighted scans were realigned, averaged, and segmented into gray matter (GM), white matter, and cerebrospinal fluid tissue type. GM maps were normalized (unmodulated) to a common space and smoothed to obtain GM density maps. The smoothed GM density maps were used to examine the association of brain damage with disease symptoms (SPM 12; partial correlation; covariates, age and gender; p<0.005). Region of interest analyses were performed in prefrontal cortices, insular lobe and hippocampus to evaluate the correlation using partial correlation (SPSS, covariates, age and gender, p<0.05).
Results
The average scores for BAI 9.55±9.90, BDI 8.69±7.05, ESS 7.00±3.72, MoCA 24.64±3.48, PSQI 6.62±3.90, maintenance 73.12±13.78, management 70.28±13.98, and confidence 73.77±15.96 were calculated. Significant negative correlations was observed between GM density values and BAI (prefrontal cortices, r=−0.532, p<0.001), BDI (prefrontal cortices, r=−0.60, p<0.001; insula, r=−0.528, p<0.001, hippocampus, r=−0.432, p<0.005), ESS (prefrontal cortices, r=−0.419, p=0.007; insula, r=−0.443, p=0.004), and PSQI (prefrontal cortices, r=−0.517, p=0.001) scores, and positive correlation between GM density values, MoCA (prefrontal cortices, r=0.462, p=0.003) and SCHFI scores (maintenance: prefrontal cortices, r=0.422, p=0.007; insula, r=0.412, p=0.009, hippocampus, r=0.455, p=0.004; management: prefrontal cortices, r=0.728, p=0.001; insula, r=0.707, p=0.001, hippocampus, r=0.775, p<0.001) (Figure 1).
Figure 1
Conclusions
HF subjects show more wide-spread and significant correlations between regional GM density values and BDI as well as SCHFI management scores compared to the other disease symptom measures. The findings suggest that damage in mood, autonomic, and cognitive functions sites better correlate with BDI and SCHFI over other measures.
Acknowledgement/Funding
NIH/NINR 1R01 NR014669
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Affiliation(s)
- M A Woo
- University of California Los Angeles, School of Nursing, Los Angeles, United States of America
| | - B Roy
- University of California Los Angeles, School of Nursing, Los Angeles, United States of America
| | - R Kumar
- University of California Los Angeles, Anesthesiology - School of Medicine, Los Angeles, United States of America
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Ghosh S, Biswas A, Roy B, Banerjee A. Self-assembly and complex manipulation of colloidal mesoscopic particles by active thermocapillary stress. Soft Matter 2019; 15:4703-4713. [PMID: 31119243 PMCID: PMC6582761 DOI: 10.1039/c9sm00721k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/16/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate that the active thermocapillary stresses induced by multiple microbubbles offer simple routes to directed self-assembly and complex but controllable micromanipulation of mesoscopic colloidal particles embedded in a liquid. The microbubbles are nucleated on a liquid-glass interface using optical tweezers. The flow around a single bubble causes self-assembly of the particles in rings at the bubble-base, while an asymmetric temperature profile generated across the bubble interface breaks the azimuthal symmetry of the flow, and induces simultaneous accumulation and repulsion of particles at different axial planes with respect to the bubble. The flow due to two adjacent bubbles leads to more diverse effects including the sorting of particles, and to local vorticity that causes radial and axial rotation of the particles - the latter being obtained for the first time using optical tweezers. The sorting is enabled by nucleating the bubbles on spatially discrete temperature profiles, while the vorticity is generated by nucleating them in the presence of a temperature gradient which once again causes a strong symmetry-breaking in the azimuthal flow. The flow profiles obtained in the experiments are explained by analytical solutions or qualitative explanations of the associated thermocapillary problem employing the Stokes and heat equations.
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Affiliation(s)
- Subhrokoli Ghosh
- Department of Physical Sciences
, Indian Institute of Science Education and Research, Kolkata
,
Mohanpur
, 741246
, India
.
| | - Aritra Biswas
- Department of Physical Sciences
, Indian Institute of Science Education and Research, Kolkata
,
Mohanpur
, 741246
, India
.
| | - Basudev Roy
- Dept of Physics
, Indian Institute of Technology Madras
,
600036
, India
| | - Ayan Banerjee
- Department of Physical Sciences
, Indian Institute of Science Education and Research, Kolkata
,
Mohanpur
, 741246
, India
.
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35
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Roy B, Basu S, Guha S, Manir K, Ahmed M, Ray S, Gangopadhayay M. Feasibility of cytoreductive surgery and intraperitoneal chemotherapy for pseudomyxoma peritonei in a rural hospital in India. Eur J Surg Oncol 2019. [DOI: 10.1016/j.ejso.2018.10.488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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36
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Roy S, Roy B, Gangopadhayay M, Basu S, Guha S, Manir K, Ahmed M, Biswas M. Open technique of intraperitoneal chemotherapy in advanced ovarian cancer- how feasible is it. Eur J Surg Oncol 2019. [DOI: 10.1016/j.ejso.2018.10.234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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37
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Buttress S, Granat M, Barratt A, Roy B. The use of gamified virtual physiotherapy as an effective treatment for patients with shoulder problems. Physiotherapy 2019. [DOI: 10.1016/j.physio.2018.11.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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38
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Hu X, Chen Y, Singh CO, Zhang S, Miao Y, Zhou Y, Xu3 J, Roy B. Research Article An improved Bac-to-Bac/BmNPV technology expressing envelope E2 glycoprotein of classical swine fever virus (CSFV) in the silkworm, <i>Bombyx mori</i>. Genet Mol Res 2019. [DOI: 10.4238/gmr18084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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39
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Bruce H, Roy B. 491 Production factors affecting the contribution of collagen to meat toughness. J Anim Sci 2018. [DOI: 10.1093/jas/sky404.599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- H Bruce
- University of Alberta,Edmonton, AB, Canada
| | - B Roy
- University of Alberta,Edmonton, AB, Canada
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Patel M, Lakhani G, Ghosh S, Nayak S, Roy B, Baghel R, Jain A. Effect of Body Condition Score on Milk Production, Milk Composition and Reproductive Performance of Lactating Murrah Buffaloes. ACTA ACUST UNITED AC 2018. [DOI: 10.20546/ijcmas.2018.711.140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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Abstract
We linearize the Stokes-Oldroyd B model for small perturbations and instantaneous hydrodynamic friction to simulate the environment for a free and confined Brownian particle. We use the standard Green's function approach to determine the viscoelasticity, and show that the expression obtained for the frequency dependent viscosity is similar to that given by the Jeffrey's model, though the latter describes viscoelasticity by the bulk storage and loss moduli that is represented by a complex elastic modulus [Formula: see text] of the fluid concerned. In contrast, we consider the characteristics of the polymer chains and the Newtonian solvent of the complex fluid individually, and determine an expression for frequency-dependent viscosity that would be useful for microrheology performed from Brownian trajectories measured in experiments. Finally, we evaluate the trajectory of a free Brownian particle in a viscoelastic environment using our formalism, and calculate various important parameters quantifying Brownian dynamics, which we then extend to the particle confined in a harmonic potential as provided by optical tweezers.
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Affiliation(s)
- Shuvojit Paul
- Indian Institute of Science Education and Research, Kolkata, India
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42
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Ramaiya A, Roy B, Bugiel M, Schäffer E. Kinesin Rotates Unidirectionally while Walking on Microtubules Transferring Torque onto Cargo. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.2785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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43
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Patil B, Sharma S, Mohanta HK, Roy B. BINIVOX catalyst for hydrogen production from ethanol by low temperature steam reforming (LTSR). J CHEM SCI 2017. [DOI: 10.1007/s12039-017-1388-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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44
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Paul S, Laskar A, Singh R, Roy B, Adhikari R, Banerjee A. Direct verification of the fluctuation-dissipation relation in viscously coupled oscillators. Phys Rev E 2017; 96:050102. [PMID: 29347721 DOI: 10.1103/physreve.96.050102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Indexed: 06/07/2023]
Abstract
The fluctuation-dissipation relation, a central result in nonequilibrium statistical physics, relates equilibrium fluctuations in a system to its linear response to external forces. Here we provide a direct experimental verification of this relation for viscously coupled oscillators, as realized by a pair of optically trapped colloidal particles. A theoretical analysis, in which interactions mediated by slow viscous flow are represented by nonlocal friction tensors, matches experimental results and reveals a frequency maximum in the amplitude of the mutual response which is a sensitive function of the trap stiffnesses and the friction tensors. This allows for its location and width to be tuned and suggests the utility of the trap setup for accurate two-point microrheology.
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Affiliation(s)
- Shuvojit Paul
- Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, India
| | - Abhrajit Laskar
- The Institute of Mathematical Sciences-HBNI, CIT Campus, Taramani, Chennai 600113, India
| | - Rajesh Singh
- The Institute of Mathematical Sciences-HBNI, CIT Campus, Taramani, Chennai 600113, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - R Adhikari
- The Institute of Mathematical Sciences-HBNI, CIT Campus, Taramani, Chennai 600113, India
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom
| | - Ayan Banerjee
- Indian Institute of Science Education and Research, Kolkata, Mohanpur 741246, India
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Roy B, Kala CP, Farooquee NA, Majila B. Indigenous Fermented Food and Beverages: A Potential for Economic Development of the High Altitude Societies in Uttaranchal. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/09709274.2004.11905665] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- B. Roy
- G.B. Pant Institute of Himalayan Environment and Development , Kosi-Katarmal, Almora 263 643, Uttaranchal, India
| | - C. Prakash Kala
- G.B. Pant Institute of Himalayan Environment and Development , Kosi-Katarmal, Almora 263 643, Uttaranchal, India
| | - Nehal A. Farooquee
- G.B. Pant Institute of Himalayan Environment and Development , Kosi-Katarmal, Almora 263 643, Uttaranchal, India
| | - B.S. Majila
- G.B. Pant Institute of Himalayan Environment and Development , Kosi-Katarmal, Almora 263 643, Uttaranchal, India
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Song X, Roy B, Kang D, Aysola RS, Macey P, Woo M, Harper R, Kumar R. 0142 DECREASED REGIONAL HOMOGENEITY IN THE DEFAULT MODE NETWORK IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Horne RS, Roy B, Walter LM, Biggs SN, Weichard A, Tamanyan K, Davey MJ, Nixon GM, Ditchfield M, Harper RM, Kumar R. 0860 REGIONAL BRAIN TISSUE INTEGRITY IN CHILDREN WITH SLEEP DISORDERED BREATHING WITH SLEEP DISORDERED BREATHING. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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48
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Rasool S, Roy B. Comparison of hospitalization rates in schizophrenic patients on first generation versus second generation antipsychotic depots. Eur Psychiatry 2017. [DOI: 10.1016/j.eurpsy.2017.01.1629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
IntroductionThere is limited data on the efficacy rates between first and second generation antipsychotic depots. One good indicator of efficacy is the rates of hospitalization. Some studies have shown that second generation depot antipsychotics significantly reduce hospitalizations rates as compared to conventional depots.ObjectivesComparison of hospitalization rates for patients with schizophrenia on first and second generation antipsychotic depots.MethodsA retrospective observational study was done by reviewing the records of an antipsychotic depot clinic in Essex, United Kingdom. A list of 47 patients enrolled and receiving depot antipsychotics was obtained. Their records were studied and hospital admission rates calculated.ResultsOf the 47 patients 11 were excluded as they were on depot antipsychotics for non-schizophrenic diagnoses.Of the 36 patients with schizophrenia, 12 were on second generation and 24 were on first generation depots.Amongst the 24 patients on first generation depots, 19 were male, 5 female and mean age was 52 years.Of the 12 patients on second generation depots, 10 were male and 2 female and mean age was 46 years.When comparing hospital admission rates between the 2 groups, the following data was noted (Table 1).ConclusionsThere is no difference in hospitalization rates between patients on first generation antipsychotic depots as compared to second generation antipsychotic depots.Disclosure of interestThe authors have not supplied their declaration of competing interest.
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Bhadra A, Karmakar G, Nahak P, Chettri P, Roy B, Guha P, Mandal A, Nath R, Panda A. Impact of detergents on the physiochemical behavior of itraconazole loaded nanostructured lipid carriers. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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50
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Roy B, Nagpaul P, Pankaj P, Mohanty T. Effect of Inorganic and Organic Zinc Supplementation on Feed Intake, Blood and Seminal Plasma Mineral Profile in Crossbred Bulls. ACTA ACUST UNITED AC 2017. [DOI: 10.5958/2231-6744.2017.00018.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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