Project description:Transition metal multi-principal element alloys (MPEAs) are novel alloys that may offer enhanced surface and mechanical properties compared with commercial metallic alloys. However, their biocompatibility has not been investigated. In this study, three CoCrFeNi-based MPEAs were fabricated, and the in vitro cytotoxicity was evaluated in direct contact with fibroblasts for 168 h. The cell viability and cell number were assessed at 24, 96, and 168 h using LIVE/DEAD assay and alamarBlue assay, respectively. All MPEA sample wells had a high percentage of viable cells at each time point. The two quaternary MPEAs demonstrated a similar cell response to stainless steel control with the alamarBlue assay, while the quinary MPEA with Mn had a lower cell number after 168 h. Fibroblasts cultured with the MPEA samples demonstrated a consistent elongated morphology, while those cultured with the Ni control samples demonstrated changes in cell morphology after 24 h. No significant surface corrosion was observed on the MPEAs or stainless steel samples following the cell culture, while the Ni control samples had extensive corrosion. The cell growth and viability results demonstrate the cytocompatibility of the MPEAs. The biocompatibility of MPEAs should be investigated further to determine if MPEAs may be utilized in orthopedic implants and other biomedical applications.
Project description:We describe the benefits of perfluoro-N-octane (PFO), a perfluorocarbon liquid, in the removal of nonmagnetic intraocular foreign bodies (IOFBs) from the macula and posterior segment. Two consecutive cases of posterior segment IOFB were reviewed. An 18-year-old male presented to the emergency room after a motor vehicle accident with a zone 1 open globe injury and large glass IOFB in the left eye. A 53-year-old male presented to the emergency room with a history of a 3-week delayed presentation of a zone 1 open globe injury from a nail to the right eye. He was found to have a metallic IOFB. In both cases, PFO was used to slide the nonmagnetic IOFBs outside of the macula for safer retrieval. PFO was also able to protect the posterior pole from IOFB drops during early attempts at removal. PFO can be a useful surgical adjunct to pars plana vitrectomy in the removal of certain nonmagnetic IOFBs.
Project description:Liquid-liquid-solid transitions (LLST) are known to occur in confined liquids, exist in supercooled liquids and emerge in liquids driven from equilibrium. Molecular dynamics (MD) simulations claim many successes in forecasting the phenomena. The transitions are also studied in the framework of thermodynamics based methods and minimalistic models. In here, the proposed approach is derived in the framework of continuum and includes spatial and temporal dynamic heterogeneities; the approach is meant to capture the material behavior at small scales. We conjecture that the liquid-like and solid-like behaviors are dissimilar enough for the two to be governed by different constitutive relations. In this way, we gain additional degree of freedom, which is found essential when predicting the transitional phenomena. As a result, we derive the LLST criteria for liquids in equilibrium, during steady flow and at transient conditions. Lastly, we forecast short-lived LLSTs in human blood during cardiac cycle.
Project description:PurposeTo report the use of short-term perfluorocarbon liquid (ST-PFCL) tamponade following choroidal melanoma endoresection.MethodsPatients with medium to large choroidal melanomas not amenable to primary Ruthenium-106 brachytherapy underwent choroidal melanoma endoresection following gamma knife radiosurgery. During surgery, a complete vitrectomy was performed followed by PFCL injection, then a retinectomy with endoresection of the melanoma and underlying choroid was done. Complete PFCL filling was then achieved, and laser barrage surrounding the retinectomy was done. A Ruthenium-106 plaque was then inserted. Postoperatively, supine positioning was maintained for three days followed by plaque and PFCL removal with silicone oil injection. Several months later, silicone oil was removed.ResultsFour eyes of 4 patients underwent endoresection with ST-PFCL tamponade. Mean height of tumor was 8.6 ± 0.85 mm, while mean maximal basal diameter was 11.5 ± 1.1 mm. Mean preoperative logMAR best corrected visual acuity (BCVA) was 1.76 ± 0.18. All patients underwent preoperative gamma knife radiosurgery and postoperative brachytherapy. There were no major intraoperative or postoperative complications. All patients underwent silicone oil injection with PFCL/plaque removal after 3 days, while silicone oil was removed after 4 ± 1.2 months. Mean postoperative logMAR BCVA 3 months following oil removal was 0.89 ± 0.22 (p = 0.02). Mean follow-up duration was 17 ± 2.8 months. No patient developed local tumor recurrence, distant metastases, or vitreoretinal complications by final visit.ConclusionST-PFCL tamponade may reduce the risk of intraoperative and postoperative complications associated with choroidal melanoma endoresection.
Project description:Direct perfluorocarbon liquid (PFCL)-silicone oil exchange presents its own set of challenges in the micro incision vitreous surgery era. We propose a simple bimanual technique to circumvent this problem. Thirteen eyes of patients with retinal detachment associated with giant retinal tears underwent vitrectomy followed by self-retaining endo illuminator (Chandelier) assisted direct PFCL-silicone exchange. No intra or postoperative complications related to the surgical technique were noted. All patients had attached retinas and satisfactory visual recovery at 6 months. Direct bimanual PFCL silicone oil exchange using a Chandelier seems to be a safe and effective technique.
Project description:In recent years, cases of retinal toxicity occurred in some European, Middle Eastern, and South American countries following the use of perfluorocarbon liquids (PFCLs) on vitreoretinal surgeries owing to impurities in the product. Moreover, Spanish ophthalmologists reported several toxic cases on the use of perfluoro-n-octane Ala Octa (Alamedics, Dornstadt, Germany), raising the necessity of reviewing the current validated methods used for assessing the safety of PFCLs. We proved that in samples of PFCLs contaminated on purpose with impurities previously detected in Ala Octa devices, the determination of the so-called H-content using a 1H NMR quantitative assay implemented with the electronic reference to access in vivo concentrations 2 technology failed to demonstrate a correlation between the H-content and in vitro cytotoxicity test in ARPE-19 and BALB 3T3 cell lines. Therefore, direct information on the safety of PFCLs was provided only by the cytotoxicity test in vitro validated according to ISO 10993-5, and the H-content was not predictive of perfluorocarbon ocular endotamponade cytotoxicity in vitro.
Project description:To assess the role for intraoperative optical coherence tomography (iOCT) during subretinal perfluoro-n-octane (PFO) removal and evaluate it as an assistive technique during surgical maneuvers.DISCOVER is a prospective study examining microscope-integrated iOCT systems in ophthalmic surgery. The authors report a technique utilizing iOCT guidance and feedback for surgical removal of chronic subretinal PFO.In this technique, real-time iOCT feedback successfully guided surgical maneuvers to facilitate removal of PFO. Due to the chronicity of the PFO, it was loculated and resistant to multiple maneuvers. Utilizing real-time feedback, additional maneuvers were attempted with feedback to the surgeon regarding the success of removal. Postoperatively, visual acuity improved with anatomic normalization.Microscope-integrated iOCT with real-time feedback provided important information to the surgeon that helped facilitate subretinal PFO removal and guided surgical maneuvers.
Project description:Ionic liquids (ILs) are structurally tunable salts with applications ranging from chemical synthesis to batteries, novel materials and medicine. Despite their potential, the toxicity of ILs poses significant environmental and biological challenges. This study introduces a comprehensive dataset of cytotoxicity of 1227 ILs, compiled from 151 research papers and encompassing 3837 data entries. For each entry, the following information is provided: substance name, empirical formula, CAS, SMILES, molecular weight, cytotoxicity value, details on the experimental setup (incubation time, cell line, assay used, etc.), and reference to the original publication. This dataset can be used for deriving structure‒activity relationships and establishing the major structural elements that govern the cytotoxic effects of ILs on eukaryotic cells. The dataset is available freely to all researchers.
Project description:The existence of more than one liquid state in a single-component system remains the most intriguing physical phenomenon. Herein, we explore the effect of cation self-assembly on ion dynamics in the vicinity of liquid-liquid and liquid-glass transition of tetraalkyl phosphonium ([Pmmm,n]+, m = 4, 6; n = 2-14) ionic liquids. We found that nonpolar local domains formed by 14-carbon alkyl chains are crucial in obtaining two supercooled states of different dynamics within a single ionic liquid. Although the nano-ordering, confirmed by Raman spectroscopy, still occurs for shorter alkyl chains (m = 6, n < 14), it does not bring calorimetric evidence of LLT. Instead, it results in peculiar behavior of ion dynamics near the liquid-glass transition and 20-times smaller size of the dynamic heterogeneity compared to imidazolium ionic liquids. These results represent a crucial step toward understanding the nature of the LLT phenomenon and offer insight into the design of efficient electrolytes based on ionic liquids revealing self-assembly behavior.
Project description:BackgroundInduction of posterior vitreous detachment (PVD) is a critical step during pars plana vitrectomy. Multiple techniques and utilities have been proposed for assistance with this step with no consensus on the safest and most effective means, especially in eyes with firmly adherent posterior hyaloid. Viscodissection or the utilization of perfluorocarbon liquid (PFCL) can be used to dissect the posterior hyaloid and widely adherent epiretinal membranes.MethodsA technique of PFCL dissection of the posterior hyaloid in eyes with abnormal adhesion of the posterior hyaloid. After core vitrectomy, breaking into the posterior hyaloid face is made via active aspiration and cutting or a sharp dissection. This is followed by active and slow injection of PFCL into the potential space between the posterior cortical vitreous and the neurosensory retina. A wave of PFCL propagates anteriorly causing "vitreo-dissection" of the peripheral cortical vitreous.ResultsThe technique was effective and safe in 8 successive cases, 4 cases with vitreoretinal traction syndrome and 4 with diabetic tractional membranes.ConclusionThe technique can be considered in cases with abnormal firmly adherent posterior hyaloid when induction of PVD proves difficult.