Personalized treatment planning in eye brachytherapy for ocular melanoma: Dosimetric analysis on ophthalmic structure at risk

Purpose: To evaluate the impact on dose distribution to eye organs-at-risk (eOARs) of a computed tomography (CT)-based treatment planning in eye plaque brachytherapy (EPB) treatment. Methods: We analyzed 19 ocular melanoma patients treated with ruthenium-106 plaques to a total dose of 100 Gy to tumor apex using conventional central-axis-point dose calculation. Treatments were re-planned using the Plaque Simulator (PS) software implementing two different strategies: a personalized CT-eye-model (CT-PS) and a standard-eye-model (SEM-PS) defined by Collaborative Ocular Melanoma Study. Dice coefficient and Hausdorff distance evaluated the concordance between eye-bulb-models. Mean doses (Dmean) to tumor and eOARs were extracted from Dose-Volume-Histograms and Retinal-Dose-Area-Histogram. Differences between planning approaches were tested by Wilcoxon signed-rank test. Results: In the analyzed cohort, 8 patients (42%) had posterior tumor location, 8 (42%) anterior, and 3 (16%) equatorial. The SEM did not accurately described the real CT eye-bulb geometry (median Hausdorff distance 0.8 mm, range: (0.4–1.3) mm). Significant differences in fovea and macula Dmean values were found (p = 0.04) between CT-PS and SEM-PS schemes. No significant dosimetric differences were found for tumor and other eOARs. The planning scheme particularly affects the OARs closest to the tumor with a general tendency of SEM-PS to overestimate the doses to the OARs closest to the tumor. Conclusion: The dosimetric accuracy achievable with CT-PS EPB treatment planning may help to identify ocular melanoma patients who could benefit the most from a personalized eye dosimetry for an optimal outcome in terms of tumor coverage and eOARs sparing. Further research and larger studies are underway

The current clinically relevant findings on COVID-19 pandemic

The emergence of a novel coronavirus and coronavirus disease 2019 (COVID-19) represents a challenge to global healthcare. In the past 20 years, this is the third coronavirus that jumped the species barrier and infected humans. It is highly contagious but associated with low pathogenicity. First identified in Wuhan, China, a city of over 11 million, the disease has since spread to every continent except Antarctica. About 15 to 20 of all cases may be called severe, and it is believed many cases are asymptomatic. The average age of a person with COVID has been reported as 49 years. Worse outcomes are associated with geriatric populations and those with un-derlying diseases such as cardiovascular, respiratory disorders, and/or diabetes. The coronavirus, like other coronaviruses, is highly contagious and has a latency period of about 14 days. Most patients present with fever and a dry cough, but fever may be absent. Differential diagnosis can be challenging since influenza may present with similar symptoms. Chest radiography or computed to-mography may be used to find evidence of secondary pneumonia. Nosocomial infection is of concern, and it has been reported that 3.8 of all cases with COVID-19 in that country involve healthcare workers in China. Most patients have mild disease, and supportive care suffices. A variety of repurposed and investigational drugs are being evaluated. There are currently no antiviral therapies or vaccines, even if many therapies are proposed. Hand hygiene, social distancing, and scientifically sound information are the best strategies at the moment to combat this epidemic. © 2020, Author(s)

Low in‑hospital mortality rate in patients with COVID‑19 receiving thromboprophylaxis: data from the multicentre observational START‑COVID Register

Abstract COVID-19 infection causes respiratory pathology with severe interstitial pneumonia and extra-pulmonary complications; in particular, it may predispose to thromboembolic disease. The current guidelines recommend the use of thromboprophylaxis in patients with COVID-19, however, the optimal heparin dosage treatment is not well-established. We conducted a multicentre, Italian, retrospective, observational study on COVID-19 patients admitted to ordinary wards, to describe clinical characteristic of patients at admission, bleeding and thrombotic events occurring during hospital stay. The strategies used for thromboprophylaxis and its role on patient outcome were, also, described. 1091 patients hospitalized were included in the START-COVID-19 Register. During hospital stay, 769 (70.7%) patients were treated with antithrombotic drugs: low molecular weight heparin (the great majority enoxaparin), fondaparinux, or unfractioned heparin. These patients were more frequently affected by comorbidities, such as hypertension, atrial fibrillation, previous thromboembolism, neurological disease,and cancer with respect to patients who did not receive thromboprophylaxis. During hospital stay, 1.2% patients had a major bleeding event. All patients were treated with antithrombotic drugs; 5.4%, had venous thromboembolism [30.5% deep vein thrombosis (DVT), 66.1% pulmonary embolism (PE), and 3.4% patients had DVT + PE]. In our cohort the mortality rate was 18.3%. Heparin use was independently associated with survival in patients aged ≥ 59 years at multivariable analysis. We confirmed the high mortality rate of COVID-19 in hospitalized patients in ordinary wards. Treatment with antithrombotic drugs is significantly associated with a reduction of mortality rates especially in patients older than 59 years

An End-User Development Approach to Secure Smart Environments

Given the spread of the Internet of Things (IoT) technology, in several contexts there is a growing need for laypeople to configure their smart devices. Task Automation Systems (TASs) have emerged as tools to simplify the definition of rules for personalizing the behavior of such devices. However, one aspect often neglected by current TASs, which is instead typical of IoT technologies, relates to the security and privacy threats exposed by the “connected” devices. This paper tries to address this problem and illustrates a user-centered design that eventually led to identify a visual paradigm that facilitates the end users in understanding and controlling security and privacy threats

Order acceptance and scheduling decisions in make-to-order systems

We examine simultaneous order acceptance and scheduling decisions where the orders are defined by their release dates, due dates, deadlines, processing times, sequence dependent setup times and revenues in a single machine environment. The objective is to maximize total revenue, where the revenue from an order is a function of its tardiness and deadline. We give an MILP formulation which can be solved to optimality up to 15 orders. We develop three heuristic algorithms to solve large sized problems. Computational tests indicate that the proposed algorithms are both computationally efficient and effective even for instances up to 300 orders.Order acceptance Single machine scheduling Sequence dependent setup times Heuristics

Correlation between the optic nerve pial diameter and radial peripapillary vascular changes in primary open-angle glaucoma

Purpose: To assess the optic nerve pial diameter (ONPD) in patients with primary open-angle glaucoma (POAG) using standardized A-scan ultrasound and to evaluate the correlation between the ONPD and structural, vascular optic nerve head features and visual field parameters in glaucomatous eyes. Methods: In this prospective study, we enrolled 126 eyes of 63 POAG patients and 124 eyes of 62 healthy controls. In all subjects, the ONPD was evaluated by means of A-scan ultrasound. Spectral domain (SD)-OCT was used to assess ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), thicknesses, and the optic nerve head (ONH) morphology. OCTA measured the vessel density (VD) of radial peripapillary capillary (RPC) plexus. Results: The ONPD showed a statistically significant reduction in POAG group with respect to controls (p < 0.001). SD-OCT and OCTA parameters showed a significant impairment in patient group with respect to controls (p < 0.001). The ONH analysis revealed significantly lower values in rim area (p = 0.009) and an increased cup-to-disc area ratio (p = 0.013) and cup volume (p < 0.001) in patients with respect to controls. Significant correlations were shown in POAG group between ONPD and RPC plexus (p = 0.006). Moreover, significant correlation was also found between ONPD and structural SD-OCT parameters (p = 0.001) and between ONPD and visual field parameters (p = 0.001). Conclusions: The standardized A-scan ultrasound measurements of the ONPD showed a significant correlation with structural and vascular glaucomatous changes measured by means of SD-OCT and OCTA. These results confirm the diagnostic reliability of the ultrasound evaluation in glaucoma optic neuropathy. [Figure not available: see fulltext.

Twenty-Year Follow-Up of Excimer Laser Photorefractive Keratectomy: A Retrospective Observational Study

Introduction: Photorefractive keratectomy (PRK) was introduced in the late 1980s to correct myopia. The purpose of this study was to assess its long-term efficacy and safety, analyzing patients with at least 20-year follow-up. Methods: This retrospective observational study was carried out on 85 eyes of 54 patients (33 females) that underwent PRK between 1991 and 1998 (mean age 32.62 ± 9.74, range 18–55&nbsp;years). Both preoperatively and postoperatively, patients underwent a complete ophthalmological evaluation, including uncorrected and corrected distance visual acuity, slit-lamp, intraocular pressure, dilated fundus, and corneal topographic examinations. The outcome assessment was made by comparing the preoperative refraction, as spherical equivalent, with the postoperative ones, taking into account the planned refractive correction. Safety and efficacy indices were also calculated. All the data were evaluated with a paired t&nbsp;test. Results: The mean attempted correction as spherical equivalent was – 5.64 ± 3.01&nbsp;D (range – 1.00 to – 15.00&nbsp;D), while the mean achieved correction after 20&nbsp;years was – 4.30 ± 3.13&nbsp;D (range – 1.88 to – 14.25&nbsp;D), with a significant statistical difference (p &lt; 0.01). The mean expected refractive outcome was – 0.27 ± 0.81&nbsp;D (range – 4.00 to + 1.25&nbsp;D). The mean difference between achieved and attempted treatment was 1.33 ± 1.92&nbsp;D (range – 4.25 to + 6.25&nbsp;D), with a significant difference (p &lt; 0.01). The safety index was 1.00 and the efficacy index was 0.63. Conclusion: The results provided by this study highlight that the procedure could be considered safe, with no long-term sight-threatening complications such as late ectasia or haze

Evaluation of corneal structures in myopic eyes more than twenty-two years after photorefractive keratectomy

The aim of this study is to evaluate corneal epithelial thickness (CET), corneal densitometry (CD) in 84 myopic eyes (57 patients) more than 22 years after photorefractive keratectomy, using anterior segment-optical coherence tomography (AS-OCT) and Scheimpflug imaging system. The CET was significantly higher in all operated eyes than in unoperated eyes in central sector. A statistically significant increase in CD in corneal anterior layer of central sector was shown in groups of operated eyes with greater ablation depth respect to unoperated eyes. While there was no significant difference in CD between the operated eyes groups with lower ablation depth and unoperated eyes. A significant trend toward higher values in anterior CD with deeper ablations in central sector was found. These noninvasive imaging techniques allow to better understand the corneal remodeling process after photoablation and to monitor the patients over time

Tuneable Control of Organocatalytic Activity through Host–Guest Chemistry

Dynamic regulation of chemical reactivity is important in many complex chemical reaction networks, such as cascade reactions and signal transduction processes. Signal responsive catalysts could play a crucial role in regulating these reaction pathways. Recently, supramolecular encapsulation was reported to regulate the activities of artificial catalysts. We present a host-guest chemistry strategy to modulate the activity of commercially available synthetic organocatalysts. The molecular container cucurbit[7]uril was successfully applied to change the activity of four different organocatalysts and one initiator, enabling up- or down-regulation of the reaction rates of four different classes of chemical reactions. In most cases CB[7] encapsulation results in catalyst inhibition, however in one case catalyst activation by binding to CB[7] was observed. The mechanism behind this unexpected behavior was explored by NMR binding studies and pKa measurements. The catalytic activity can be instantaneously switched during operation, by addition of either supramolecular host or competitive binding molecules, and the reaction rate can be predicted with a kinetic model. Overall, this signal responsive system proves a promising tool to control catalytic activity.ChemE/Advanced Soft Matte