When remembering the past, we typically recall ‘events’ that are bounded in time and space. However, as we navigate our environment our senses receive a continuous stream of information. How do we create discrete long-term episodic memories from continuous input? Although previous research has provided evidence for a role of spatial boundaries in the online segmentation of our sensory experience within working memory, it is not known how this segmentation contributes to subsequent long-term episodic memory. Here we show that the presence of a spatial boundary at encoding (a doorway between two rooms) impairs participants’ later ability to remember the order that objects were presented in. A sequence of two objects presented in the same room in a virtual reality environment is more accurately remembered than a sequence of two objects presented in adjoining rooms. The results are captured by a simple model in which items are associated to a context representation that changes gradually over time, and changes more rapidly when crossing a spatial boundary. We therefore provide the first evidence that the structure of long-term episodic memory is shaped by the presence of a spatial boundary and provide constraints on the nature of the interaction between working memory and long-term memory.

The key to successful management of rhegmatogenous retinal detachment (RRD) is to find and seal all of the retinal breaks, and the two main surgical techniques used to achieve this are scleral bucking (SB) or pars plana vitrectomy (PPV). Techniques for SB have remained mostly unchanged for the last 60 years, whilst PPV techniques and instruments have developed substantially over that time and have greatly contributed to increased success rate for types and configurations of retinal detachments unsuitable or difficult to manage with buckling alone. However, there is a growing dependency to rely on PPVas the sole and only approach for repair of all types of retinal detachment, such that some centres are no longer offering training in scleral buckling. There are also many studies comparing SB with PPV, but many of these lack information on the type, technique or rationale for deployment of the buckle. Many studies deploy the same scleral buckle technique without customising it to the type, position or number of tears being treated. Scleral buckling is not a one-size-fits-all technique. It requires careful patient selection and careful buckle selection and orientation tailored to the tear(s) to ensure success. When used appropriately, it is a simple and highly effective technique, particularly for retinal dialyses, round retinal hole detachments and selected cases of retinal detachment associated with horseshoe retinal tears. There is no doubt that for some more complex cases, such as multiple large breaks, giant retinal tears, bullous detachments and cases complicated by proliferative retinopathy, PPV offers a safer and more effective management. However, SB remains an important and relevant surgical technique, and for the right cases, the results can be superior to PPV with reduced comorbidity.

Introduction While patients with acute uncomplicated appendicitis may be treated conservatively, those who suffer from complicated appendicitis require surgery. We describe a logistic regression equation to calculate the likelihood of acute uncomplicated appendicitis and complicated appendicitis in patients presenting to the emergency department with suspected acute appendicitis. Materials and methods A cohort of 895 patients who underwent appendicectomy were analysed retrospectively. Depending on the final histology, patients were divided into three groups; normal appendix, acute uncomplicated appendicitis and complicated appendicitis. Normal appendix was considered the reference category, while acute uncomplicated appendicitis and complicated appendicitis were the nominal categories. Multivariate and univariate regression models were undertaken to detect independent variables with significant odds ratio that can predict acute uncomplicated appendicitis and complicated appendicitis. Subsequently, a logistic regression equation was generated to produce the likelihood acute uncomplicated appendicitis and complicated appendicitis. Results Pathological diagnosis of normal appendix, acute uncomplicated appendicitis and complicated appendicitis was identified in 188 (21%), 525 (59%) and 182 patients (20%), respectively. The odds ratio from a univariate analysis to predict complicated appendicitis for age, female gender, log2 white cell count, log2 C-reactive protein and log2 bilirubin were 1.02 (95% confidence interval, CI, 1.01, 1.04), 2.37 (95% CI 1.51, 3.70), 9.74 (95% CI 5.41, 17.5), 1.57 (95% CI 1.40, 1.74), 2.08 (95% CI 1.56, 2.76), respectively. For the same variable, similar odds ratios were demonstrated in a multivariate analysis to predict complicated appendicitis and univariate and multivariate analysis to predict acute uncomplicated appendicitis. Conclusions The likelihood of acute uncomplicated appendicitis and complicated appendicitis can be calculated by using the reported predictive equations integrated into a web application at www.appendistat.com. This will enable clinicians to determine the probability of appendicitis and the need for urgent surgery in case of complicated appendicitis.

The development of rapid, highly sensitive detection methods for α-fetoprotein (AFP) is very important. As hepatocellular carcinoma is closely related to the level of AFP in the blood, it is necessary to maintain an AFP concentration below the safety limit. In this paper, we propose a universal, rapid, sensitive, and highly specific immunoassay system utilizing gold nanoparticles (AuNPs) and surface-enhanced Raman scattering (SERS). This new system features a sandwich structure combining mercaptobenzoic acid-labeled immunogold nanoparticles with the antigen and the antibody atop a pre-designed substrate made of a glass slide modified with AuNPs. This SERS-based immunoassay can detect AFP concentrations as low as 100 pg/ml, which is a significant improvement on the capabilities of the enzyme-linked immunosorbent assay method. A good linear relationship between the SERS peak intensity and the logarithm of antigen concentrations (from 1 ng/ml to 100 ng/ml) was observed. This technique provides an effective model for the detection of biomarkers in medical diagnostics, criminal investigation, and other fields.