Detection of phase singularities with a Shack-Hartmann wavefront sensor

While adaptive optical systems are able to remove moderate wavefront distortions in scintillated optical beams, phase singularities that appear in strongly scintillated beams can severely degrade the performance of such an adaptive optical system. Therefore, the detection of these phase singularities is an important aspect of strong scintillation adaptive optics. We investigate the detection of phase singularities with the aid of a Shack-Hartmann wavefront sensor and show that, in spite of some systematical deficiencies inherent to the Shack-Hartmann wavefront sensor, it can be used for the reliable detection of phase singularities, irrespective of their morphologies. We provide full analytical results, together with numerical simulations of the detection process.Comment: 23 pages, 9 figure

Analyses of CD27++ Plasma Cells in Peripheral Blood from Patients with Bacterial Infections and Patients with Serum Antinuclear Antibodies

The number of CD27++ plasma cells (PCs) in peripheral blood may be a valuable biomarker for systemic lupus erythematosus (SLE) disease management. More insights into the behavior of the PC population are, however, required to validate CD27 as a reliable biomarker. In the current study, we have monitored the PC compartment of patients with acute bacterial infections and patients with SLE and, in addition, examined the relationship between the presence of serum antinuclear antibodies (ANAs) and the number of peripheral PCs. Kinetic analyses in patients with bacterial infection revealed a 10–60-fold expansion of the CD27++ PC compartment that peaked at day 2–5 and returned toward normal values at day 7–9 after hospital admission. The transient expansion of the PC population appeared to be a late phenomenon in the process of recovering from a bacterial infection. SLE subjects had significantly increased frequencies of PCs compared with patients suspected of a connective tissue disease and healthy controls. In patients suspected of a connective tissue disease, no relationship was found between the presence of serum ANAs and the number of CD27++ PCs. Additionally, the presence of serum ANAs was not associated with abnormalities in other peripheral B-cell subsets. It remains to be established at which stage of SLE development the expansion of the PC compartment is initiated

Image-guided in situ detection of bacterial biofilms in a human prosthetic knee infection model:a feasibility study for clinical diagnosis of prosthetic joint infections

Purpose Due to an increased human life expectancy, the need to replace arthritic or dysfunctional joints by prosthetics is higher than ever before. Prosthetic joints are unfortunately inherently susceptible to bacterial infection accompanied by biofilm formation. Accurate and rapid diagnosis is vital to increase therapeutic success. Yet, established diagnostic modalities cannot directly detect bacterial biofilms on prostheses. Therefore, the present study was aimed at investigating whether arthroscopic optical imaging can accurately detect bacterial biofilms on prosthetic joints. Methods Here, we applied a conjugate of the antibiotic vancomycin and the near-infrared fluorophore IRDye800CW, in short vanco-800CW, in combination with arthroscopic optical imaging to target and visualize biofilms on infected prostheses. Results We show in a human post-mortem prosthetic knee infection model that a staphylococcal biofilm is accurately detected in real time and distinguished from sterile sections in high resolution. In addition, we demonstrate that biofilms associated with the clinically most relevant bacterial species can be detected using vanco-800CW. Conclusion The presented image-guided arthroscopic approach provides direct visual diagnostic information and facilitates immediate appropriate treatment selection

Regularization of Brane Induced Gravity

We study the regularization of theories of ``brane induced'' gravity in codimension $N>1$. The brane can be interpreted as a thin dielectric with a large dielectric constant, embedded in a higher dimensional space. The kinetic term for the higher dimensional graviton is enhanced over the brane. A four dimensional gravitation is found on the brane at distances smaller than a critical distance $r<r_c$, and is due to the exchange of a massive resonant graviton. The crossover scale $r_c$ is determined by the mass of the resonance. The suppression of the couplings of light Kaluza-Klein modes to brane matter results in a higher dimensional force law at large distances. We show that the resulting theory is free of ghosts or tachyons.Comment: One reference added. To appear in PRD. 20 pages, 3 figure

Elimination of Schistosoma mansoni Adult Worms by Rhesus Macaques: Basis for a Therapeutic Vaccine?

Infection with blood-dwelling schistosome worms is a major cause of human disease in many tropical countries. Despite intensive efforts a vaccine has proved elusive, not least because the chronic nature of the infection provides few pointers for vaccine development. The rhesus macaque appears unique among animal models in that adult worms establish but are eventually lost. We investigated whether this was due to pathological or immunological causes by monitoring the fate of a schistosome infection, and were able to rule out escape of worms from the portal system as a result of egg-induced vascular shunts. A substantial worm population established in all animals but there was a wide variation in the numbers recovered at 18 weeks. We observed a strong inverse association between the rapidity and intensity of the IgG response and worm burden. Rather than an acute lethal attack, immune-mediated elimination of worms appeared to be a prolonged process directed against vital components of exposed surfaces, causing worms to starve to death. We suggest that if the mechanisms deployed by the rhesus macaque could be replicated in humans by administration of key recombinant antigens, they would form the basis for a vaccine with both prophylactic and therapeutic properties

A new thin film photochromic material: Oxygen-containing yttrium hydride

In this work we report on photochromism in transparent thin film samples of oxygen-containing yttrium hydride. Exposure to visible and ultraviolet (UV) light at moderate intensity triggers a decrease in the optical transmission of visible and infrared (IR) light. The photo-darkening is colour-neutral. We show that the optical transmission of samples of 500 nm thickness can be reduced by up to 50% after one hour of illumination with light of moderate intensity. The reaction is reversible and samples that are left in the dark return to the initial transparent state. The relaxation time in the dark depends on the temperature of the sample and the duration of the light exposure. The photochromic reaction takes place under ambient conditions in the as-deposited state of the thin-film samples.Comment: Accepted for publication in Solar Energy Materials and Solar Cell

Prospective Volumetric Assessment of the Liver on a Personal Computer by Nonradiologists Prior to Partial Hepatectomy

Ó The Author(s) 2010. This article is published with open access at Springerlink.com Background A small remnant liver volume is an important risk factor for posthepatectomy liver failure. ImageJ and OsiriX Ò are both free, open-source image processing software packages. The aim of the present study was to compare ImageJ and OsiriX Ò in performing prospective computed tomography (CT) volumetric analysis of the liver on a personal computer (PC) in patients undergoing major liver resection. Methods Patients scheduled for a right hemihepatectomy were eligible for inclusion. Two surgeons and one surgical trainee measured volumes of total liver, tumor, and future resection specimen prospectively with ImageJ and OsiriX Ò. A radiologist also measured these volumes with CT scanner-linked Aquarius iNtuition Ò software. Resection volumes were compared with the actual weights of the live

Predicting overall survival and resection in patients with locally advanced pancreatic cancer treated with FOLFIRINOX:Development and internal validation of two nomograms

Background and Objectives Patients with locally advanced pancreatic cancer (LAPC) are increasingly treated with FOLFIRINOX, resulting in improved survival and resection of tumors that were initially unresectable. It remains unclear, however, which specific patients benefit from FOLFIRINOX. Two nomograms were developed predicting overall survival (OS) and resection at the start of FOLFIRINOX for LAPC. Methods From our multicenter, prospective LAPC registry in 14 Dutch hospitals, LAPC patients starting first-line FOLFIRINOX (April 2015-December 2017) were included. Stepwise backward selection according to the Akaike Information Criterion was used to identify independent baseline predictors for OS and resection. Two prognostic nomograms were generated. Results A total of 252 patients were included, with a median OS of 14 months. Thirty-two patients (13%) underwent resection, with a median OS of 23 months. Older age, female sex, Charlson Comorbidity Index 1, involvement of the superior mesenteric artery, celiac trunk, and superior mesenteric vein >= 270 degrees were independent factors decreasing the probability of resection (c-index: 0.79). Conclusions Two nomograms were developed to predict OS and resection in patients with LAPC before starting treatment with FOLFIRINOX. These nomograms could be beneficial in the shared decision-making process and counseling of these patients

Treatment strategies and clinical outcomes in consecutive patients with locally advanced pancreatic cancer:A multicenter prospective cohort

Introduction: Since current studies on locally advanced pancreatic cancer (LAPC) mainly report from single, high-volume centers, it is unclear if outcomes can be translated to daily clinical practice. This study provides treatment strategies and clinical outcomes within a multicenter cohort of unselected patients with LAPC. Materials and methods: Consecutive patients with LAPC according to Dutch Pancreatic Cancer Group criteria, were prospectively included in 14 centers from April 2015 until December 2017. A centralized expert panel reviewed response according to RECIST v1.1 and potential surgical resectability. Primary outcome was median overall survival (mOS), stratified for primary treatment strategy. Results: Overall, 422 patients were included, of whom 77% (n = 326) received chemotherapy. The majority started with FOLFIRINOX (77%, 252/326) with a median of six cycles (IQR 4-10). Gemcitabine monotherapy was given to 13% (41/326) of patients and nab-paclitaxel/gemcitabine to 10% (33/326), with a median of two (IQR 3-5) and three (IQR 3-5) cycles respectively. The mOS of the entire cohort was 10 months (95%CI 9-11). In patients treated with FOLFIRINOX, gemcitabine monotherapy, or nab-paclitaxel/gemcitabine, mOS was 14 (95%CI 13-15), 9 (95%CI 8-10), and 9 months (95%CI 8-10), respectively. A resection was performed in 13% (32/252) of patients after FOLFIRINOX, resulting in a mOS of 23 months (95%CI 12-34). Conclusion: This multicenter unselected cohort of patients with LAPC resulted in a 14 month mOS and a 13% resection rate after FOLFIRINOX. These data put previous results in perspective, enable us to inform patients with more accurate survival numbers and will support decision-making in clinical practice. (C) 2020 The Authors. Published by Elsevier Ltd