ABSTRACT
The use of nano-additives is widely recognized as a cheap and effective pathway to improve the performance of lubrication by minimizing the energy loss from friction and wear, especially in diesel engines. In this work, a simple and scalable protocol was proposed to fabricate a graphene additive to improve the engine lubricant oil. Graphene nanoplates (GNPs) were obtained by a one-step chemical exfoliation of natural graphite and were successfully modified with a surfactant and an organic compound to obtain a modified GNP additive, that can be facilely dispersed in lubricant oil. The GNPs and modified GNP additive were characterized using scanning electron microscopy, X-ray diffraction, atomic force microscopy, Raman spectroscopy, and Fourier-transform infrared spectroscopy. The prepared GNPs had wrinkled and crumpled structures with a diameter of 10-30 µm and a thickness of less than 15 nm. After modification, the GNP surfaces were uniformly covered with the organic compound. The addition of the modified GNP additive to the engine lubricant oil significantly enhanced the friction and antiwear performance. The highest reduction of 35% was determined for the wear scar diameter with a GNP additive concentration of approximately 0.05%. The mechanism for lubrication enhancement by graphene additives was also briefly discussed.
ABSTRACT
A 45-year-old Caucasian female with diagnosis of central serous chorioretinopathy (CSCR) did not improve on conventional observational approach. She was not willing to proceed with photocoagulation or photodynamic therapy. An unconventional approach of topical anti-inflammatory (ketorolac, dexamethasone and hydrocortisone) preparation was prescribed. The course of her CSCR responded well on this unconventional treatment, but relapsed on cessation or tapering of treatment. After 18 weeks of treatment with a gradual taper, her condition resolved. The present case highlights an alternative but unconventional treatment of CSCR with prolonged use of anti-inflammatories.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Central Serous Chorioretinopathy/drug therapy , Dexamethasone/administration & dosage , Hydrocortisone/administration & dosage , Ketorolac/administration & dosage , Central Serous Chorioretinopathy/diagnosis , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Fluorescein Angiography , Follow-Up Studies , Humans , Middle Aged , Ophthalmic Solutions , Recurrence , Tomography, Optical Coherence , Visual Acuity/drug effectsABSTRACT
PURPOSE: To report the reliability in detecting age-related maculopathy (ARM) lesions before cataract surgery and postoperative visual acuity (VA) in cataract surgery patients with ARM. METHODS: Medical records of surgical patients in a large public hospital, west of Sydney, were reviewed retrospectively. Detection of ARM lesions was compared before and after surgery to determine sensitivity and specificity of preoperative diagnoses. Postoperative VA was assessed 4 weeks after surgery. RESULTS: Data were available for 721/784 eyes (92.0%) of 656 patients aged 60 years or older. ARM lesions were detected in 98 eyes (13.6%) before and 92 eyes (12.8%) after surgery. Sensitivities for detecting late ARM lesions, soft drusen and retinal pigment epithelium abnormalities preoperatively were 100%, 94% and 69%, respectively. Corresponding specificities were 100%, 100% and 77%, respectively. Postoperative VA achieved or remained 6/12 or better in 81.6% of eyes. CONCLUSION: A high sensitivity and specificity in detecting late ARM lesions and soft drusen preoperatively, and a good postoperative VA outcome is achievable in patients with preoperative early ARM lesions.
