Vortex nucleation as a case study of symmetry breaking in quantum systems

Mean-field methods are a very powerful tool for investigating weakly interacting many-body systems in many branches of physics. In particular, they describe with excellent accuracy trapped Bose-Einstein condensates. A generic, but difficult question concerns the relation between the symmetry properties of the true many-body state and its mean-field approximation. Here, we address this question by considering, theoretically, vortex nucleation in a rotating Bose-Einstein condensate. A slow sweep of the rotation frequency changes the state of the system from being at rest to the one containing one vortex. Within the mean-field framework, the jump in symmetry occurs through a turbulent phase around a certain critical frequency. The exact many-body ground state at the critical frequency exhibits strong correlations and entanglement. We believe that this constitutes a paradigm example of symmetry breaking in - or change of the order parameter of - quantum many-body systems in the course of adiabatic evolution.Comment: Minor change

Risk Factors for Endophthalmitis and Retinal Detachment with Retained Intraocular Foreign Bodies

Purpose. To analyze risk factors for endophthalmitis and retinal detachment (RD) in patients with retained intraocular foreign bodies (IOFBs). Design. A retrospective, interventional, consecutive case series. Participants. All patients treated at Bascom Palmer Eye Institute for traumatic IOFBs between 1999 and 2008. Methods. Analysis of visual outcome, mechanism of injury, management, and postoperative course. Results. 108 eyes with IOFBs were identified. Endophthalmitis occurred in 7 eyes (6.4%) at presentation, and risk was higher with vegetable matter exposure (P = 0.003). All eyes with posterior segment IOFBs received intravitreal antibiotics and there were no cases of endophthalmitis after initial management. RD was identified in 6 of 108 eyes (5.5%) at presentation. Risk factors were entry more than 5 mm behind the limbus (P < 0.001) and posterior segment IOFB (P = 0.028). Postoperative RD occurred in 11 of 102 eyes (10.7%). Risk factors for postoperative RD were preoperative endophthalmitis (P = 0.001), posterior segment IOFB (P = 0.008), and retinal impact sites (P = 0.028). Conclusions. Risk factors for endophthalmitis included vegetable matter exposure and delay to initial management. Risk factors for RD were posterior entry site, posterior segment IOFB, endophthalmitis, and retinal impact sites. No eyes developed endophthalmitis after presentation

A Comparative Study of Responses to Retina Questions from Either Experts, Expert-Edited Large Language Models, or Expert-Edited Large Language Models Alone

OBJECTIVE: To assess the quality, empathy, and safety of expert edited large language model (LLM), human expert created, and LLM responses to common retina patient questions. DESIGN: Randomized, masked multicenter study. PARTICIPANTS: Twenty-one common retina patient questions were randomly assigned among 13 retina specialists. METHODS: Each expert created a response (Expert) and then edited a LLM (ChatGPT-4)-generated response to that question (Expert + artificial intelligence [AI]), timing themselves for both tasks. Five LLMs (ChatGPT-3.5, ChatGPT-4, Claude 2, Bing, and Bard) also generated responses to each question. The original question along with anonymized and randomized Expert + AI, Expert, and LLM responses were evaluated by the other experts who did not write an expert response to the question. Evaluators judged quality and empathy (very poor, poor, acceptable, good, or very good) along with safety metrics (incorrect information, likelihood to cause harm, extent of harm, and missing content). MAIN OUTCOME: Mean quality and empathy score, proportion of responses with incorrect information, likelihood to cause harm, extent of harm, and missing content for each response type. RESULTS: There were 4008 total grades collected (2608 for quality and empathy; 1400 for safety metrics), with significant differences in both quality and empathy ( CONCLUSIONS: In this randomized, masked, multicenter study, LLM responses were comparable with experts in terms of quality, empathy, and safety metrics, warranting further exploration of their potential benefits in clinical settings. FINANCIAL DISCLOSURES: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of the article

Unassisted Scleral Depression During Vitrectomy Surgery: Two Simple, Cost-Effective Techniques

The ability to visualize and work in the region of the vitreous base during vitrectomy surgery is important. However, this usually requires the use of a surgical assistant for scleral depression or expensive chandelier systems requiring extra incisions. The authors describe two alternative simple, cost-effective techniques to independently and simultaneously view and cut (or apply laser) in this difficult anatomical region. Light-pipe assisted scleral depression using a standard light pipe and ring depressor indentation while maintaining two intraocular instruments are described. The described techniques are simple, cost-effective, safe, suitable for phakic and pseudo-phakic patients, and allow the surgeon to operate independently with maximum control

Management of suprachoroidal 5,000-centistoke silicone oil: two contrasting approaches

Two patients experienced unplanned infusion of suprachoroidal 5,000-centistoke silicone oil during vitrectomy surgery. In one patient the oil was surgically removed using an internal incision in the pars plana choroid after external aspiration failed. The oil was expressed from the suprachoroidal space through this opening into the vitreous cavity. Perfluorocarbon liquid was injected over the posterior pole to displace residual suprachoroidal oil into the vitreous cavity, and the oil was then removed via the existing sclerotomy. In the second patient, the oil was observed, and the patient had a stable visual and anatomic outcome at 1-year follow-up