MyMedR

Fulltext Enhancement of Particle Alignment Using Silicone Oil Plasticizer and Its Effects on the Field-Dependent Properties of Magnetorheological Elastomers

Khairi MHA, Fatah AYA, Mazlan SA, Ubaidillah U, Nordin NA, Ismail NIN, et al.

Int J Mol Sci, 2019 Aug 21;20(17).

PMID: 31438576 DOI: 10.3390/ijms20174085

The existing mold concept of fabricating magnetorheological elastomer (MRE) tends to encounter several flux issues due to magnetic flux losses inside the chamber. Therefore, this paper presents a new approach for enhancing particle alignment through MRE fabrication as a means to provide better rheological properties. A closed-loop mold, which is essentially a fully guided magnetic field inside the chamber, was designed in order to strengthen the magnetic flux during the curing process with the help of silicone oil (SO) plasticizers. The oil serves the purpose of softening the matrix. Scanning electron microscopy (SEM) was used to observe the surface morphology of the fabricated MRE samples. The field-dependent dynamic properties of the MREs were measured several ways using a rheometer, namely, strain sweep, frequency sweep, and magnetic field sweep. The analysis implied that the effectiveness of the MRE was associated with the use of the SO, and the closed-loop mold helped enhance the absolute modulus up to 0.8 MPa. The relative magnetorheological (MR) effects exhibited high values up to 646%. The high modulus properties offered by the MRE with SO are believed to be potentially useful in industry applications, particularly as vibration absorbers, which require a high range of stiffness.

Matched MeSH terms: Silicone Oils/chemistry*

Fulltext A rare case of disciform keratitis in a silicone-filled eye presenting with 'sticky oil' on the endothelium

Bastion ML, Zahidin AZ

BMJ Case Rep, 2010;2010.

PMID: 22750927 DOI: 10.1136/bcr.11.2009.2497

An unusual case of disciform keratitis developing in a patient with silicone oil-filled eye following vitrectomies for posterior globe rupture.

Matched MeSH terms: Silicone Oils/administration & dosage*

Fulltext A Case of a Large Sub-retinal Abscess Secondary to Klebsiella pneumoniae Endophthalmitis in a Pyelonephritis Patient

Mohd-Ilham I, Zulkifli M, Yaakub M, Muda R, Shatriah I

Cureus, 2019 May 14;11(5):e4656.

PMID: 31316877 DOI: 10.7759/cureus.4656

Endogenous endophthalmitis is an ocular emergency, with severe sight-threatening complications. We report a case of unilateral endogenous Klebsiella pneumonia endophthalmitis with a large sub-retinal abscess in a 39-year-old lady that developed four days after presentation with sepsis secondary to urinary tract infections and pyelonephritis. Despite immediate treatment with intravenous (IV) and intravitreal antibiotics, her eye condition deteriorated. A pars plana vitrectomy was performed, and the sub-retinal abscess was removed, followed by silicone oil tamponade. Subsequently, she regained her vision to 6/36 with complete regression of the intraocular inflammation and sub-retinal abscess.

Matched MeSH terms: Silicone Oils

Fulltext Short-term postoperative perfluoro-n-octane tamponade for pediatric recurrent retinal detachment

Ling KP, Wu AL, Lai CC, Wu WC

Taiwan J Ophthalmol, 2019 1 15;8(4):249-252.

PMID: 30637197 DOI: 10.4103/tjo.tjo_100_18

We report a case with multiple recurrences of retinal detachment (RD) with severe proliferative vitreoretinopathy in a 12-year-old child who underwent vitrectomy using a heavy liquid perfluoro-n-octane (PFO) as a short-term postoperative tamponade. He had an encircling band and three vitrectomies with gas, followed by silicone oil tamponade for retinal redetachment prior to the use of PFO as a short-term tamponade. Short-term PFO tamponade was used in which inferior retinal reattachment was considered to be difficult with conventional gas or silicone oil tamponade, especially in regard to proper postoperative posturing. The PFO was left in the eye for 1 week, and the retina remained reattached after removal of the PFO which was replaced with silicone oil tamponade in this case. PFO appears feasible and tolerable as a short-term postoperative tamponade in the management of complex pediatric RD.

Matched MeSH terms: Silicone Oils

Fulltext Bilateral Giant Retinal Tear and Sequential Vitrectomy

Mustapha M, Roufail Franzco E

Case Rep Ophthalmol, 2017 08 17;8(2):436-439.

PMID: 28924443 DOI: 10.1159/000479728

PURPOSE: To describe the excellent outcome of surgery for bilateral giant retinal tears (GRTs) with better options of endotamponade.

METHODS: This is a case report of a 62-year-old man who presented with bilateral GRTs and associated retinal detachment. The tear in the right eye was supero-temporal and silicone oil was used as an endotamponade. The tear in the left eye was infero-temporal and perfluorocarbon liquid was used as an endotamponade.

RESULTS: The outcome at 6 months after surgery was excellent with visual acuities of 6/6 in both eyes.

CONCLUSION: Improved availability of endotamponade agents allows repair of bilateral GRTs to be done at the same time, with good surgical outcomes.

Matched MeSH terms: Silicone Oils

Fulltext Development of patient-specific 3D-printed breast phantom using silicone and peanut oils for magnetic resonance imaging

Sindi R, Wong YH, Yeong CH, Sun Z

Quant Imaging Med Surg, 2020 Jun;10(6):1237-1248.

PMID: 32550133 DOI: 10.21037/qims-20-251

Background: Despite increasing reports of 3D printing in medical applications, the use of 3D printing in breast imaging is limited, thus, personalized 3D-printed breast model could be a novel approach to overcome current limitations in utilizing breast magnetic resonance imaging (MRI) for quantitative assessment of breast density. The aim of this study is to develop a patient-specific 3D-printed breast phantom and to identify the most appropriate materials for simulating the MR imaging characteristics of fibroglandular and adipose tissues.

Methods: A patient-specific 3D-printed breast model was generated using 3D-printing techniques for the construction of the hollow skin and fibroglandular region shells. Then, the T1 relaxation times of the five selected materials (agarose gel, silicone rubber with/without fish oil, silicone oil, and peanut oil) were measured on a 3T MRI system to determine the appropriate ones to represent the MR imaging characteristics of fibroglandular and adipose tissues. Results were then compared to the reference values of T1 relaxation times of the corresponding tissues: 1,324.42±167.63 and 449.27±26.09 ms, respectively. Finally, the materials that matched the T1 relaxation times of the respective tissues were used to fill the 3D-printed hollow breast shells.

Results: The silicone and peanut oils were found to closely resemble the T1 relaxation times and imaging characteristics of these two tissues, which are 1,515.8±105.5 and 405.4±15.1 ms, respectively. The agarose gel with different concentrations, ranging from 0.5 to 2.5 wt%, was found to have the longest T1 relaxation times.

Conclusions: A patient-specific 3D-printed breast phantom was successfully designed and constructed using silicone and peanut oils to simulate the MR imaging characteristics of fibroglandular and adipose tissues. The phantom can be used to investigate different MR breast imaging protocols for the quantitative assessment of breast density.

Matched MeSH terms: Silicone Oils

Fulltext Successful visual outcome following vitrectomy for complication of ocular tuberculosis

Norshamsiah, M.D., Muhaya, M., Bastion, M.L.C.

Journal of Surgical Academia, 2012;2(2):56-59.

MyJurnal

A 24-year-old Chinese gentleman presented with two weeks history of sudden floaters in his right temporal visual field associated with blurring of vision. This ex-smoker also reported chronic, bloody cough for two years and recent pleuritic chest pain. Examination revealed a thin patient with right eye visual acuity of 6/18 associated with optic nerve dysfunction, optic disc swelling and macula star, retinal vasculitis and retinitis. Despite anti-tuberculosis medication and corticosteroids, he developed neovascularisation. Subsequent vitreous haemorrhage necessitated trans pars plana vitrectomy, membrane peeling, endolaser and silicone oil injection. Final visual acuity was 6/9 with quiescent retinopathy.

Matched MeSH terms: Silicone Oils

Fulltext Pneumatic retinopexy for treatment of posterior pole detachment following vitreoretinal surgery for diabetic tractional retinal detachment threatening the fovea

Bastion ML

BMJ Case Rep, 2012;2012.

PMID: 22878988 DOI: 10.1136/bcr-2012-006303

To describe the usage of 100% perfluoropropane and subsequent laser retinopexy for the repair of posterior pole retinal detachment in a previously vitrectomised patient with diabetic tractional detachment.

Matched MeSH terms: Silicone Oils

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