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Full-Text Articles in Bioimaging and Biomedical Optics

Dual Color Optogenetic Control For Analyzing Cardiac Function In Drosophila, Jiantao Zhu May 2023

Dual Color Optogenetic Control For Analyzing Cardiac Function In Drosophila, Jiantao Zhu

McKelvey School of Engineering Theses & Dissertations

Prolonged consumption of carbohydrate-rich diets and immobile lifestyles frequently cause metabolic disorders and obesity and, as a result, may lead to progressive heart dysfunction among broad social groups of the population. Drosophila melanogaster serves as an essential model organism in cardiovascular disease research due to conserved physiological and genomic traits shared with humans, its genetic and molecular toolbox versatility, and cost-effective maintenance. Here, we combine optogenetics and optical coherence tomography to study cardiovascular function in D. melanogaster. A new optogenetic pacing system has been developed, employing a transgenic line carrying two opsins: ChR2 and NpHR2.0. A custom-built hardware setup …


The Influence Of Mmp14 On Angiogenesis In Chemotherapy-Treated Tumors, Abdussaboor Muhammad May 2022

The Influence Of Mmp14 On Angiogenesis In Chemotherapy-Treated Tumors, Abdussaboor Muhammad

Biomedical Engineering Undergraduate Honors Theses

Colorectal cancer is the third most common cancer in the world, and it is the fourth most common cause of cancer related death (1). There have been many significant advancements regarding the treatment of cancer which aim to shrink the size of tumors in patients. However, there is still more that needs to be understood about the many different factors that play a role in colorectal cancer development.

Angiogenesis is the process of forming new blood vessels from existing ones and it requires breaking down and remodeling of the extracellular matrix (ECM) in order to allow endothelial cells to migrate …


Nonlinear Optical Microscopy Assessment Of Tissue Structure And Chondrocyte Viability Of Articular Cartilage, Michael Le May 2022

Nonlinear Optical Microscopy Assessment Of Tissue Structure And Chondrocyte Viability Of Articular Cartilage, Michael Le

All Theses

Articular cartilage functions to protect the ends of bones by providing a surface that can withstand compressive forces and minimize friction during movement. Collagen fibers form the organizational backbone of the extracellular matrix (ECM) in cartilage. Proteoglycans within the ECM function to retain water and provide the tissue with the swelling pressure needed to withstand compressional forces. Chondrocytes, the only type of cell found in articular cartilage, produces these collagen fibers and proteoglycans to maintain the tissue structure and function. Significant injuries to articular cartilage can damage the chondrocytes and disrupt their ability to maintain homeostasis in the tissue. Therefore, …


K-Wire Differentiation, Oluwadamilola Oluwadara, Lillian Maresco, Eunjung Lee, Michelle De Leon Jun 2021

K-Wire Differentiation, Oluwadamilola Oluwadara, Lillian Maresco, Eunjung Lee, Michelle De Leon

Honors Theses

Kirschner Pins, known as K-wires, are smooth sharp stainless steel pins used in the field of orthopedics to stabilize bone fracture fragments in their correct position until they have fully healed. K-wires are most commonly used for comminuted metaphyseal fractures of the long bones, and fractures of smaller bones such as the phalanges. The wires are inserted into bone via a drill and the ends of the wire are bent and left outside of the body for easy removal once the bone has healed. The surgeon uses x-ray images to guide K-wire insertion, ensure proper internal alignment, and determine if …


Preclinical Development Of Single Walled Carbon Nanotube-Based Optical Biosensors, Eric M. Hofferber Apr 2021

Preclinical Development Of Single Walled Carbon Nanotube-Based Optical Biosensors, Eric M. Hofferber

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

High resolution, long-term monitoring of key biological analytes would improve patient outcomes by providing earlier detection of disease states and improved efficacy of treatment. One class of biosensors that have gained much attention in recent years are optical biosensors. Optical probes are attractive biosensors due to their noninvasive nature of detection, as certain light can pass through tissue, water, and blood. Single walled carbon nanotubes (SWNT) are a specific type of optical biosensor that fluoresce in the near infrared range of the electromagnetic spectrum and offer unparalleled spatial and temporal resolution. SWNT have been applied as biosensors in vitro, …


Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand Jan 2021

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …


3d Architectural Analysis Of Neurons, Astrocytes, Vasculature & Nuclei In The Motor And Somatosensory Murine Cortical Columns, Jared Leichner Jul 2020

3d Architectural Analysis Of Neurons, Astrocytes, Vasculature & Nuclei In The Motor And Somatosensory Murine Cortical Columns, Jared Leichner

FIU Electronic Theses and Dissertations

Characterization of the complex cortical structure of the brain at a cellular level is a fundamental goal of neuroscience which can provide a better understanding of both normal function as well as disease state progression. Many challenges exist however when carrying out this form of analysis. Immunofluorescent staining is a key technique for revealing 3-dimensional structure, but subsequent fluorescence microscopy is limited by the quantity of simultaneous targets that can be labeled and intrinsic lateral and isotropic axial point-spread function (PSF) blurring during the imaging process in a spectral and depth-dependent manner. Even after successful staining, imaging and optical deconvolution, …


Investigation Of Experimental Variation Of Bovine Sphingomyelin As A Novel Ingredient For Ultraviolet Protection, Esther Chen Jun 2020

Investigation Of Experimental Variation Of Bovine Sphingomyelin As A Novel Ingredient For Ultraviolet Protection, Esther Chen

Master's Theses

Skin cancer is a prevalent disease that globally affects 2-3 million people per year [1]. This number is expected to grow tenfold as depletion of the ozone layer contributes to harsher rays reaching Earth’s surface [2]. A common way to protect against those ultraviolet waves is to apply sunscreen, however, recent reports call into question the safety of some active ingredients as they can enter through the skin into the bloodstream [3]. This thesis aims to investigate an alternative solution that uses bovine sphingomyelin (BSM) as photoprotective solution against UV irradiation.

In order to evaluate the effectiveness of BSM against …


The Utilization Of Autofluorescence To Study The Effects Of L-Buthionine-Sulfoximine On Cellular Metabolism In Vitro, Madison Belew May 2020

The Utilization Of Autofluorescence To Study The Effects Of L-Buthionine-Sulfoximine On Cellular Metabolism In Vitro, Madison Belew

Biomedical Engineering Undergraduate Honors Theses

Oxidative damage and stress impacts metabolic activity and has been implicated in a number of diseases . These medical conditions have been found to be associated with a lack of glutathione (GSH). There is a need to study the effects that the absence of glutathione has in order to expand knowledge of indicators that cause conditions like cataracts, cancer, or impaired wound healing. L-buthionine-sulfoximine (BSO) has been used in past studies to hinder GSH production and induce oxidative stress within a cell. This study explores the effects of BSO and induced oxidative stress on the metabolic activity and processes within …


Design, Construction And Application Of A Home-Built, Two-Photon Microscope, William P. Breeding Aug 2019

Design, Construction And Application Of A Home-Built, Two-Photon Microscope, William P. Breeding

Electronic Theses and Dissertations

Two-photon microscopy (TPM) is a powerful, versatile imaging modality for the study of biological systems. This thesis overviews the relevant physics involved in TPM, design considerations and process of constructing a home-built, two-photon microscope, and provides a set of procedures to operate the system. Furthermore, this work explores several applications of TPM through the study of single-cell metabolism and imaging the cellular-material interface. Explored in particular depth was the imaging of cellulose nanofiber (CNF) materials, with the goal of understanding the three-dimensional nature of fibroblast cell growth when embedded within the materials. This work uncovered several optical properties of CNF, …


Vector Flow Imaging In Pediatric Cardiology - Extracting And Validating Data, Mason Belue May 2019

Vector Flow Imaging In Pediatric Cardiology - Extracting And Validating Data, Mason Belue

Biomedical Engineering Undergraduate Honors Theses

In the field of bedside cardiac diagnostic imaging, Doppler Ultrasound (DU) is the gold standard for diagnosing heart conditions. The largest benefit of DU is its ability to noninvasively image cardiac flow and allow the estimation of blood velocity and quantification of anatomical disease. However, to get correct velocity estimation, the position of the transducer in relation to the flow field needs to be known. This is the problem of angle/direction dependency and limits DUs accuracy when imaging in areas where perfect alignment or exact position of the transducer in relation to flow field is not possible or known, such …


Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre May 2019

Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre

Honors Scholar Theses

Abnormal ocular motility is a common manifestation of many underlying pathologies particularly those that are neurological. Dynamics of saccades, when the eye rapidly changes its point of fixation, have been characterized for many neurological disorders including concussions, traumatic brain injuries (TBI), and Parkinson’s disease. However, widespread saccade analysis for diagnostic and research purposes requires the recognition of certain eye movement parameters. Key information such as velocity and duration must be determined from data based on a wide set of patients’ characteristics that may range in eye shapes and iris, hair and skin pigmentation [36]. Previous work on saccade analysis has …


Extraction And Analysis Of Vector Flow Imaging Data In A Pediatric Population, Bailey Stinnett May 2018

Extraction And Analysis Of Vector Flow Imaging Data In A Pediatric Population, Bailey Stinnett

Biomedical Engineering Undergraduate Honors Theses

Vector flow imaging (VFI) is a new ultrasound technology that provides real time, angle-independent visualization of flow velocities in the heart and great vessels. Thus far, VFI has been used for superficial applications due to the limited penetration depth of available transducer probes; however, this depth in smaller pediatric patients enables adequate aortic views. In this project, VFI was used to study pediatric aortic stenosis (PAS)—a congenital heart defect that results in the narrowing of the aorta and/or aortic valve. The decision to refer PAS patients for surgical or catheter-based intervention is initially based on Doppler ultrasound. VFI is potentially …


Modeling Eeg And Tdcs In Scirun Software Packages, Aiden Keene, Aiden Thomas Keene May 2018

Modeling Eeg And Tdcs In Scirun Software Packages, Aiden Keene, Aiden Thomas Keene

Senior Honors Projects

Never before has there been a greater emphasis on improving the shortcomings of treating mental health conditions. Our generation has more knowledge about technological practices with the potential to monitor and treat mental health symptoms than that of any generation before us. A breakthrough in this field made by CREmedical is called Tripolar Concentric Ring Electrodes (TCRE’s), which can measure signals from the brain more accurately than conventional electrodes. At CREmedical, TCREs are being used to study differences in electrical activity in the brain so as to identify abnormalities, and monitor responses to stimulation therapies. This semester I had the …


Computer-Aided Diagnoses (Cad) System: An Artificial Neural Network Approach To Mri Analysis And Diagnosis Of Alzheimer's Disease (Ad), Berizohar Padilla Cerezo Dec 2017

Computer-Aided Diagnoses (Cad) System: An Artificial Neural Network Approach To Mri Analysis And Diagnosis Of Alzheimer's Disease (Ad), Berizohar Padilla Cerezo

Master's Theses

Alzheimer’s disease (AD) is a chronic and progressive, irreversible syndrome that deteriorates the cognitive functions. Official death certificates of 2013 reported 84,767 deaths from Alzheimer’s disease, making it the 6th leading cause of death in the United States. The rate of AD is estimated to double by 2050. The neurodegeneration of AD occurs decades before symptoms of dementia are evident. Therefore, having an efficient methodology for the early and proper diagnosis can lead to more effective treatments.

Neuroimaging techniques such as magnetic resonance imaging (MRI) can detect changes in the brain of living subjects. Moreover, medical imaging techniques are the …


Optimizing A Standard Fasting Time For 2-Nbdg Uptake Studies In Murine Breast Cancers, Andrew C. Briley May 2017

Optimizing A Standard Fasting Time For 2-Nbdg Uptake Studies In Murine Breast Cancers, Andrew C. Briley

Biomedical Engineering Undergraduate Honors Theses

Recently, there has been a larger use of 2-NBDG, a fluorescent glucose analog, to study glucose uptake in different cell types. These cell types have ranged anywhere from bacteria to human cancer cells. However, there has yet to be a standard procedure and practice for using 2-NBDG. In this study, our goal is to create a standard fasting time for the cells before introducing 2-NBDG to them. This study uses 4T07 cells, a murine breast cancer cell line, to help optimize this fasting time. These cells were fasted at different time points in order to find the ideal fasting time. …


The Effect Of Hyperthermia On Doxorubicin Therapy And Nanoparticle Penetration In Multicellular Ovarian Cancer Spheroids, Abhignyan Nagesetti Feb 2017

The Effect Of Hyperthermia On Doxorubicin Therapy And Nanoparticle Penetration In Multicellular Ovarian Cancer Spheroids, Abhignyan Nagesetti

FIU Electronic Theses and Dissertations

The efficient treatment of cancer with chemotherapy is challenged by the limited penetration of drugs into the tumor. Nanoparticles (10 – 100 nanometers) have emerged as a logical choice to specifically deliver chemotherapeutics to tumors, however, their transport into the tumor is also impeded owing to their bigger size compared to free drug moieties. Currently, monolayer cell cultures, as models for drug testing, cannot recapitulate the structural and functional complexity of in-vivo tumors. Furthermore, strategies to improve drug distribution in tumor tissues are also required. In this study, we hypothesized that hyperthermia (43°C) will improve the distribution of silica nanoparticles …


Mri Field Mapping Using Bssfp Elliptical Signal Model, Joseph Valentine, Meredith Taylor, Steven Whitaker, Michael Hoff, Neal Bangerter Feb 2017

Mri Field Mapping Using Bssfp Elliptical Signal Model, Joseph Valentine, Meredith Taylor, Steven Whitaker, Michael Hoff, Neal Bangerter

Biomedical Engineering Western Regional Conference

MRI, Field Mapping, bSSFP, ssfp, Elliptical Signal model, ellipse, phase unwrapping


Engineering Fret Biosensors For Microrna Presence/Absence Analysis, Nicholas E. Larkey, Sean M. Burrows Feb 2017

Engineering Fret Biosensors For Microrna Presence/Absence Analysis, Nicholas E. Larkey, Sean M. Burrows

Biomedical Engineering Western Regional Conference

No abstract provided.


A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox Dec 2016

A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox

Electronic Theses and Dissertations

We explored the capabilities of additive manufacturing using a photo-cured jetted material 3D printer to manufacture a milli-microfluidic device with direct application in microalgae Dunaliella sp growth and intracellular compounds biosynthesis tests. A continuous microbioreactor for microalgae culture was CAD designed and successfully built in 1 hour and 49 minutes using black photopolymer cured by UV and a support material. The microreactor was made up of 2 parts including the bioreactor itself and a microchannel network for culture media fluids and microalgae. Both parts were assembled to form a single unit. Additional optical and auxiliar components were added. An external …


Fluorochlorozirconate Glass Ceramics For Computed Radiography, Adam Wesley Evans Aug 2016

Fluorochlorozirconate Glass Ceramics For Computed Radiography, Adam Wesley Evans

Masters Theses

Heat treating fluorochlorozirconate (FCZ) glasses nucleates nanocrystals in the glass matrix, resulting in a glass ceramic that has optical properties suitable for use as a medical imaging plate. As the temperature of heat treatment rises, the resulting FCZ glass-ceramic becomes increasingly more opaque as the size of the orthorhombic phase BaCl­2[barium chloride] nanocrystals grow within the glass matrix. This opaqueness negatively affects imaging. The effect of adding Fe3+[iron] on the valence state of zirconium and overall glass quality was investigated.

Samples were synthesized and characterized with differential scanning calorimetry to determine the temperature of the orthorhombic …


Optimized Protocol For Measuring 2-Nbdg Uptake As A Cellular Marker Of Glycolytic Demand, Drew Folgmann May 2016

Optimized Protocol For Measuring 2-Nbdg Uptake As A Cellular Marker Of Glycolytic Demand, Drew Folgmann

Biomedical Engineering Undergraduate Honors Theses

2[N-(7-nitrobenz-2-oxa-1,2-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG) a fluorescently tagged analog of FDG is ideal for in vitro studies and imaging. 2-NBDG has been proven to be an adequate marker for glucose uptake in many different types of cells [1]. However, across the spectrum of 2-NBDG use a lack of consensus is observed for the following questions. What is the ideal time to fast cells to optimize cellular uptake of 2-NBDG? Also, what is the ideal concentration of 2-NBDG to be used when quantifying glucose uptake? Finally, what is the effect of serum on the uptake of 2-NBDG? To answer these questions and understand glucose …


Circle Of Willis Model For Transcranial Doppler Ultrasound Training, Conner J. Beyersdorf, Ben Hage, Greg Bashford Apr 2016

Circle Of Willis Model For Transcranial Doppler Ultrasound Training, Conner J. Beyersdorf, Ben Hage, Greg Bashford

UCARE Research Products

Transcranial Doppler (TCD) ultrasound is a technique involving the use of high frequency transmitters to measure intracranial blood flow. The brain is supplied by blood in an arterial anastomosis called the Circle of Willis. Using TCD ultrasound on the circle is difficult and requires practice and teaching. A functional model of the Circle of Willis could prove to be a valuable teaching tool. Through the use of AutoCAD and 3D printing software, an anatomically accurate model was created and set in gelatin phantom inside of a plastic skull. Milk was pumped through the model with a peristaltic pump to simulate …


Analysis Of Breath-Holding Index As An Assessment Of Cerebrovascular Reactivity, Allison P. Porter, Madison Burger, Mohammed Alwatban, Benjamin Hage, Greg Bashford Apr 2016

Analysis Of Breath-Holding Index As An Assessment Of Cerebrovascular Reactivity, Allison P. Porter, Madison Burger, Mohammed Alwatban, Benjamin Hage, Greg Bashford

UCARE Research Products

Cerebrovascular reactivity (CVR) is a key factor in regulating blood flow into the brain, and a marker for vascular disease. If the brain's regulatory system is not working, a patient may be in serious trouble. Testing of CVR is one method of assessing the brain's regulatory capabilities. Transcranial Doppler ultrasound (TCD) is one tool to measure CVR. In this method, carbon dioxide in the blood is transiently increased (such as with the holding of breath), and the resulting blood flow in the brain is measured. In this study, we are going to measure the variability of the breathholding index.

Within …


Cobalt Ferrite Nanoparticles Fabricated Via Co-Precipitation In Air: Overview Of Size Control And Magnetic Properties, Dennis Toledo Nov 2015

Cobalt Ferrite Nanoparticles Fabricated Via Co-Precipitation In Air: Overview Of Size Control And Magnetic Properties, Dennis Toledo

FIU Electronic Theses and Dissertations

Cobalt Ferrite has important, size-dependent magnetic properties. Consequently, an overview of particle size is important. Co-precipitation in air was the fabrication method used because it is comparatively simple and safe. The effects of three different reaction times including 1, 2, 3 hour(s) on particle size were compared. Also, the effectiveness of three different capping agents (Oleic Acid, Polyvinylpyrollidone (PVP), and Trisodium Citrate) in reducing aggregation and correspondingly particle size were examined. Using Welch’s analysis of variance (ANOVA) and the relevant post hoc tests, there was no significant difference (p=0.05) between reaction times of 1 hour and 2 hours, but there …


Signal Processing Methods For Quantitative Power Doppler Microvascular Angiography, Mai H. Elfarnawany Aug 2015

Signal Processing Methods For Quantitative Power Doppler Microvascular Angiography, Mai H. Elfarnawany

Electronic Thesis and Dissertation Repository

Operator-dependent instrument settings and the likelihood of image artifacts are two challenges for reliably using three-dimensional (3-D) power Doppler angiography in flow depiction and quantification applications.

To address the operator-dependent settings challenge, an automated method for wall filter cut-off selection, the wall filter selection curve (WFSC) method, was developed using flow-phantom images. The flow-phantom WFSCs guided the development of a theoretical signal model relating color pixel density (CPD) and wall filter cut-off frequency. Simulations using the theoretical model were used to define criteria for the WFSC method to be applied to unprocessed power Doppler signals from 3-D vasculature. The adapted …


Measuring Blood Flow In The Skeletal Muscle Microcirculation Using Laser Speckle Flowmetry, Kenneth Howard Gouin Iii Jul 2015

Measuring Blood Flow In The Skeletal Muscle Microcirculation Using Laser Speckle Flowmetry, Kenneth Howard Gouin Iii

Biomedical Engineering

The presence of a native collateral circulation, which serves as a natural bypass for blood flow around an occlusion, improves prognosis for patients with ischemic diseases, such as peripheral arterial occlusive disease (PAOD). However, not all patients have a native collateral circulation, and animal models suggest a genetic basis for this variability. In mice, such as the BALB/c, that lack native arteriolar collaterals, neocollateral formation from capillaries that connect two arterial trees can occur after arterial occlusion, resulting in reperfusion of the ischemic watershed. Immature arterialized collateral capillaries (ACCs) at 7 days post arterial occlusion do not vasodilate in response …


Characterization Of Low Density Intracranial Lesions Using Dual-Energy Computed Tomography, Jessica L. Nute May 2015

Characterization Of Low Density Intracranial Lesions Using Dual-Energy Computed Tomography, Jessica L. Nute

Dissertations & Theses (Open Access)

Calcific and hemorrhagic foci of susceptibility are frequently encountered on routine brain MR studies. Both etiologies cause variations in local magnetic field strength, leading to dark regions on the MR images that cannot be classified. Single-energy CT (SECT) can be used to identify lesions with attenuation over 100 HU as calcific, however lesions with lower attenuation cannot be reliably identified. While calcific lesions are unlikely to cause harm, hemorrhagic lesions carry a risk of subsequent intracranial bleeding; as such, identification of hemorrhage is vital in preventing the inappropriate use of anticoagulant medications in patients with hemorrhagic lesions.

Given there currently …


Nerve Fiber Diameter Measurements Using Hematoxylin And Eosin Staining And Brightfield Microscopy To Assess The Novel Method Of Characterizing Peripheral Nerve Fiber Distributions By Group Delay, Jorge Arturo Vazquez Aug 2014

Nerve Fiber Diameter Measurements Using Hematoxylin And Eosin Staining And Brightfield Microscopy To Assess The Novel Method Of Characterizing Peripheral Nerve Fiber Distributions By Group Delay, Jorge Arturo Vazquez

Master's Theses

Peripheral neuropathies are a set of common diseases that affect the peripheral nervous system, causing damage to vital connections between various parts of the body and the brain and spinal cord. Different clinical conditions are known to selectively impact various size nerve fibers, which often makes it difficult to diagnose which peripheral neuropathy a patient might have. The nerve conduction velocity diagnostic test provides clinically useful information in the diagnosis of some peripheral neuropathies. This method is advantageous because it tends to be minimally invasive yet it provides valuable diagnostic information. However, this test does not determine characteristics of peripheral …


Application Of Limited Mixing In The Hele-Shaw Geometry In Fabrication Of Janus Hydrogels, Md Mahmudur Rahman Jul 2014

Application Of Limited Mixing In The Hele-Shaw Geometry In Fabrication Of Janus Hydrogels, Md Mahmudur Rahman

Md Mahmudur Rahman

It is widely accepted that cells behave differently responding to the stiffness of their extracellular matrix (ECM). Such observations were made by culturing cells on hydrogel substrates of tunable stiffness. However, it was recently proposed that cells may sense how strongly they are tethered to ECM, not the local stiffness of ECM. To investigate both hypotheses, we developed a method to fabricate Janus polyacrylamide (PAAM) gels. We squeeze two drops of different concentrations in the Hele-Shaw geometry to generate radial Stokes flow. When the drops coalesce, limited mixing occurs at the interface due to the narrow confinement, and diffusion normal …