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Indian Journal of Ophthalmology Apr 2022Detaching a rectus muscle irreparably destroys its ciliary artery circulation which also supplies the anterior segment of the eye.
BACKGROUND
Detaching a rectus muscle irreparably destroys its ciliary artery circulation which also supplies the anterior segment of the eye.
PURPOSE
To educate strabismus surgeons about a method of detaching a muscle without compromising anterior segment circulation.
SYNOPSIS
A limbal based conjunctival incision is made. The muscle is identified, separated from its attachments and secured with 6-0 Vicryl. The anterior ciliary vessel supplying it is isolated by making a small snip incision in the muscle capsule with delicate blunt dissection parallel to the anterior ciliary artery The muscle is detached from its original insertion. The muscle is tied to sclera at the intended point of recession. The intact anterior ciliary artery, thus will continue to function, untouched.
HIGHLIGHTS
We recommend pre-placing the sutures in the muscle and also in the sclera at the point of reattachment to avoid possible stretching and breaking of anterior ciliary vessels at the time of muscle detachment and also to dissect the artery free from muscle several millimeters more than the intended recession in order to spare the anterior ciliary circulation in strabismus surgery.
VIDEO LINK
https://youtu.be/Bn050Ihu9rU.
Topics: Conjunctiva; Humans; Ischemia; Oculomotor Muscles; Sclera; Strabismus; Surgical Wound
PubMed: 35326085
DOI: 10.4103/ijo.IJO_629_22 -
Science Bulletin Dec 2023After two continents collide, plate convergence and orogenesis are sustained because subducted continental lithosphere continues pulling the surface plate. It remains...
After two continents collide, plate convergence and orogenesis are sustained because subducted continental lithosphere continues pulling the surface plate. It remains controversial how, why, and when continental plate convergence and collision slow down and eventually cease. We use an unprecedented data coverage and present a regional-scale seismic tomographic image of the mantle structure beneath the Tibetan Plateau. In the mantle transition zone, we identify multiple high-velocity anomalies and interpret them as detached pieces of the Indian continental slab. Facilitated by internal heterogeneity of the continental lithosphere, piecewise slab detachments could reduce the slab pull force, resulting in the Miocene slowdown of the India-Eurasia convergence and coeval diachronous potassic volcanism in southern Tibet. We propose that slab detachment is a mechanism that eventually will lead to the end of the Indo-Eurasian continental collision and the Himalayan orogeny.
PubMed: 37919155
DOI: 10.1016/j.scib.2023.10.017 -
Ultrasonics Sonochemistry Nov 2022The strength of cell adhesion is important in understanding the cell's health and in culturing them. Quantitative measurement of cell adhesion strength is a significant...
The strength of cell adhesion is important in understanding the cell's health and in culturing them. Quantitative measurement of cell adhesion strength is a significant challenge in bioengineering research. For this, the present study describes a system that can measure cell adhesion strength using acoustic streaming induced by Lamb waves. Cells are cultured on an ultrasound transducer using a range of preculture and incubation times with phosphate-buffered saline (PBS) just before the measurement. Acoustic streaming is then induced using several Lamb wave intensities, exposing the cells to shear flows and eventually detaching them. By relying upon a median detachment rate of 50 %, the corresponding detachment force, or force of cell adhesion, was determined to be on the order of several nN, consistent with previous reports. The stronger the induced shear flow, the more cells were detached. Further, we employed a preculture time of 8 to 24 h and a PBS incubation time of 0 to 60 min, producing cell adhesion forces that varied from 1.2 to 13 nN. Hence, the developed system can quantify cell adhesion strength over a wide range, possibly offering a fundamental tool for cell-based bioengineering.
Topics: Cell Adhesion; Acoustics; Mechanical Phenomena
PubMed: 36257212
DOI: 10.1016/j.ultsonch.2022.106204 -
Graefe's Archive For Clinical and... 1989Fourier operations on digitized radio-frequency (rf) data can provide the most sensitive measure of the thickness of thin, deterministic structures such as membranes....
Fourier operations on digitized radio-frequency (rf) data can provide the most sensitive measure of the thickness of thin, deterministic structures such as membranes. After deconvolution against the system transfer function, the cepstrum and the analytic signal magnitude can provide measures of membrane thickness on the order of a half-wavelength. A total of 19 patients with rhegmatogenous retinal detachments were scanned using a diagnostic ultrasound system adapted for analog to digital conversion of rf data. Data were analyzed using the signal processing techniques described above to measure retinal thickness. Recent retinal detachments tended to be significantly thicker than normal attached retinas, and thickness decreased with the age of detachment. A statistically significant correlation was found to exist between retinal thickness and the duration of detachment.
Topics: Adolescent; Adult; Aged; Female; Fourier Analysis; Humans; Male; Middle Aged; Retina; Retinal Detachment; Signal Processing, Computer-Assisted; Time Factors; Ultrasonography
PubMed: 2646175
DOI: 10.1007/BF02169819 -
Journal Francais D'ophtalmologie 1993We conducted a retrospective study of 84 retinal detachments in 69 consecutive children under 15 years of age, operated using microsurgical techniques. The goal of this... (Review)
Review
We conducted a retrospective study of 84 retinal detachments in 69 consecutive children under 15 years of age, operated using microsurgical techniques. The goal of this study was to evaluate the prognosis following this surgical approach. Trauma was the most frequent etiology (34.6% of eyes), followed by high myopia (31% of eyes). The other etiologies were varied. Cicatricial retinopathy of prematurity was the most common of them (9.5% of eyes). The series was characterised by the severity of retinal detachment at initial presentation with total retinal detachment in 44% of eyes, detached macula in 70.3% of eyes and severe PVR in 29.8% of eyes. Sixty nine of the 84 eyes were operated on. Thirty two eyes were managed using transscleral microsurgery and 37 eyes (53.6%) required vitrectomy. Permanent retinal reattachment was achieved in 51 of the 69 eyes (73.9%). The present series of retinal detachments in children was highly heterogeneous. Retinal detachments related to retinogenic retinal breaks (atrophic holes and oral dialyses) were more common compared with adult retinal detachments. Their prognosis after surgery was excellent. In contrast traction retinal detachments and detachments related to vitreogenic retinal tears were characterised by a more guarded prognosis. However microsurgical techniques have made the most severe cases, such as grade D2-D3 PVR, giant tears with an inverted posterior flap and detachments after penetrating eye injuries, amenable to surgical management with encouraging results.
Topics: Adolescent; Age Factors; Child; Child, Preschool; Female; Humans; Infant; Male; Microsurgery; Prognosis; Retinal Detachment; Retrospective Studies; Time Factors
PubMed: 8331247
DOI: No ID Found -
Bulletin of Mathematical Biology Oct 2007During a wound-healing cell migration assay experiment, cells are observed to detach and undergo mitosis before reattaching as a pair of cells on the substrate. During...
During a wound-healing cell migration assay experiment, cells are observed to detach and undergo mitosis before reattaching as a pair of cells on the substrate. During experiments with mice 3T3 fibroblasts, cell detachment can be confined to the wavefront region or it can occur over the whole wave profile. A multi-species continuum approach to modelling a wound-healing assay is taken to account for this phenomenon. The first cell population is composed of attached motile cells, while the second population is composed of detached immotile cells undergoing mitosis and returning to the migrating population after successful division. The first model describes cell division occurring only in the wavefront region, while a second model describes cell division over the whole of the scrape wound. The first model reverts to the Fisher equation when the reattachment rate relative to the detachment rate is large, while the second case does not revert to the Fisher equation in any limit. The models yield travelling wave solutions. The minimum wave speed is slower than the minimum Fisher wave speed and its dependence on the cell detachment and reattachment rate parameters is analysed. Approximate travelling wave profiles of the two cell populations are determined asymptotically under certain parameter regimes.
Topics: 3T3 Cells; Algorithms; Animals; Cell Adhesion; Cell Migration Assays; Cell Movement; Cell Proliferation; Cell Survival; Fibroblasts; Mice; Models, Biological; Time Factors; Wound Healing
PubMed: 17577601
DOI: 10.1007/s11538-007-9206-0 -
Langmuir : the ACS Journal of Surfaces... Feb 2014Detachment of droplets from solid surfaces is a basic and crucial process in practical applications such as heat transfer and digital microfluidics. In this study,...
Detachment of droplets from solid surfaces is a basic and crucial process in practical applications such as heat transfer and digital microfluidics. In this study, electrowetting actuations with square pulse signals are employed to detach droplets from a hydrophobic surface. The threshold voltage for droplet detachment is obtained both experimentally and theoretically to find that it is almost constant for various droplet volumes ranging from 0.4 to 10 μL. It is also found that droplets can be detached more easily when the width of applied pulse is well-matched to the spreading time (i.e., the time to reach the maximum spread diameter). When the droplet is actuated by a double square pulse, the threshold voltage is reduced by ∼20% from that for a single square pulse actuation. Finally, by introducing an interdigitated electrode system, it is demonstrated that droplets can be detached from the solid bottom surface without using a top needle electrode.
PubMed: 24490590
DOI: 10.1021/la404344y -
Microbiology Spectrum Feb 2022Patients with chronic respiratory diseases use home nebulizers that are often contaminated with pathogenic microbes to deliver aerosolized medications. The conditions...
Patients with chronic respiratory diseases use home nebulizers that are often contaminated with pathogenic microbes to deliver aerosolized medications. The conditions under which these microbes leave the surface as bioaerosols during nebulization are not well characterized. The objectives of this study were to (i) determine whether different pathogens detach and disperse from the nebulizer surface during aerosolization and (ii) measure the effects of relative humidity and drying times on bacterial surface detachment and aerosolization. Bacteria were cultured from bioaerosols after Pari LC Plus albuterol nebulization using two different sources, as follows: (i) previously used nebulizers donated by anonymous patients with cystic fibrosis (CF) and (ii) nebulizers inoculated with bacteria isolated from the lungs of CF patients. Fractionated bioaerosols were collected with a Next-Generation Impactor. For a subset of bacteria, surface adherence during rewetting was measured with fluorescence microscopy. Bacteria dispersed from the surface of used CF patient nebulizers during albuterol nebulization. Eighty percent (16/20) of clinical isolates inoculated on the nebulizer in the laboratory formed bioaerosols. Detachment from the plastic surface into the chamber solution predicted bioaerosol production. Increased relative humidity and decreased drying times after inoculation favored bacterial dispersion on aerosols during nebulized therapy. Pathogenic bacteria contaminating nebulizer surfaces detached from the surface as bioaerosols during nebulized therapies, especially under environmental conditions when contaminated nebulizers were dried or stored at high relative humidity. This finding emphasizes the need for appropriate nebulizer cleaning, disinfection, and complete drying during storage and informs environmental conditions that favor bacterial surface detachment during nebulization. Studies from around the world have demonstrated that many patients use contaminated nebulizers to deliver medication into their lungs. While it is known that using contaminated medications in a nebulizer can lead to a lung infection, whether bacteria on the surface of a contaminated nebulizer detach as bioaerosols capable of reaching the lung has not been studied. This work demonstrates that a subset of clinical bacteria enter solution from the surface during nebulization and are aerosolized. Environmental conditions of high relative humidity during storage favor dispersion from the surface. We also provide results of an assay conducted to monitor bacterial surface detachment during multiple cycles of rewetting that correlate with the results of nebulizer/bacterial surface interactions. These studies demonstrate for the first time that pathogenic bacteria on the nebulizer surface pose a risk of bacterial inhalation to patients who use contaminated nebulizers.
Topics: Aerosols; Bacteria; Bacterial Adhesion; Cystic Fibrosis; Equipment Contamination; Humans; Nebulizers and Vaporizers
PubMed: 35107362
DOI: 10.1128/spectrum.02535-21 -
Langmuir : the ACS Journal of Surfaces... Jan 2021This article presents the first experimental-computational study on the centrifugal detachment of a compound droplet (e.g., a primary water droplet cloaked by an...
This article presents the first experimental-computational study on the centrifugal detachment of a compound droplet (e.g., a primary water droplet cloaked by an immiscible oil) from a fiber. The work was intended to establish a method for quantifying the force needed to detach compound droplets of different compositions from a fiber. More importantly, our study was aimed at improving the understanding of the interplay between interfacial and external forces acting on a compound droplet during forceful detachment. The experiments were conducted using DI water, for the primary droplet, and silicone or mineral oil, for the cloaking fluid. It was observed from the experiments that the silicone-oil-cloaked droplets behave differently from the mineral-oil-cloaked droplets. It was also observed that detachment force decreases with increasing the oil-to-water volume ratio. The simulations were performed using the Surface Evolver (SE) finite element code programmed for the complicated four-phase (air, water, oil, and solid) interfacial problem at hand. Our simulations revealed the evolution of the interfacial forces between the interacting phases under an increasing external body force on the droplet. The simulations also allowed us to define effective interfacial tensions and contact angles for detaching compound droplets, for the first time. Reasonable agreement was observed between the experimental measurements and computational results.
PubMed: 33398995
DOI: 10.1021/acs.langmuir.0c03317 -
Micromachines Feb 2023To expand the applications of the electroencephalogram (EEG), long-term measurement, a short installation time, and little stress on the participants are needed. In this...
To expand the applications of the electroencephalogram (EEG), long-term measurement, a short installation time, and little stress on the participants are needed. In this study, we designed, fabricated, and evaluated an EEG headset with three candle-like microneedle electrodes (CMEs). The user is able to detach and reattach the electrodes, enabling long-term measurement with little stress. The design of the CMEs was experimentally determined by considering the skin-to-electrode impedance and user comfort. An EEG was successfully measured from areas with a high hair density without any preparation. The installation time was shorter than 60 s and the electrodes could be detached and reattached. The headset was designed such that the discomfort caused by its ear pads was higher than that caused by the electrodes. In 1 h experiments, the participants did not feel pain and the detachment of the CMEs was found to improve the comfort level of the participants in most cases. A successful demonstration of the long-term measurement of EEGs while watching a whole movie verified that the developed EEG headset with CMEs is applicable for EEG measurement in a variety of applications.
PubMed: 36838100
DOI: 10.3390/mi14020400