Sticky physics of joy: On the dissolution of spherical candies

Assuming a constant mass-decrease per unit-surface and -time we provide a very simplistic model for the dissolution process of spherical candies. The aim is to investigate the quantitative behavior of the dissolution process throughout the act of eating the candy. In our model we do not take any microscopic mechanism of the dissolution process into account, but rather provide an estimate which is based on easy-to-follow calculations. Having obtained a description based on this calculation, we confirm the assumed behavior by providing experimental data of the dissolution process. Besides a deviation from our prediction caused by the production process of the candies below a diameter of 2 mm, we find good agreement with our model-based expectations. Serious questions on the optimal strategy of enjoying a candy will be addressed, like whether it is wise to split the candy by breaking it with the teeth or not

Erfahrungen mit "half-dose" photodynamischer Therapie mittels Verteporfin bei Chorioretinopathia centralis serosa

Zusammenfassung: Hintergrund: Chorioretinopathia centralis serosa (CCS) ist eine idiopathische, meist selbstlimitierende Erkrankung gewöhnlich jüngerer Patienten. Charakteristisches Zeichen ist eine seröse Abhebung der neurosensorischen Retina. Die Visusprognose ist gut. In bis zu 30% der Fälle kann die Erkrankung chronisch oder rezidivierend sein. Es gibt das Risiko der Entwicklung einer sekundären choroidalen Neovaskularisation. Therapeutische Optionen sind Laserphotokoagulation oder photodynamische Therapie mit Verteporfin (PDT). In den letzten Jahren ist zur Minimierung von Nebenwirkungen der PDT das Behandlungsprotokoll modifiziert worden. Diese Protokolle werden als "Half-dose-" oder "Reduce-fluence-" bzw. "Low-fluence-PDT" bezeichnet. Patienten und Methoden: Retrospektiv wurden 7Augen von 6 konsekutiven männlichen Patienten mit chronischer CCS ausgewertet. Vor "Half-dose-PDT" und am Ende des Follow-up wurden der bestkorrigierte Visus sowie die Netzhautdicke mittels "spectral-domain" optischer Kohärenztomographie bestimmt. Ergebnisse: Das Durchschnittsalter lag bei 40,7 ± 10,3Jahren. Fünf Augen erhielten 1, 1Auge 2 und 1Auge 3 "Half-dose-PDT". Das durchschnittliche Follow-up lag bei 79,8 ± 104,5Monaten. Der Visus (Snellen) war vor PDT bei 0,4 ± 0,2 und nach PDT bei 0,4 ± 0,3 (p = 0,49). Die Netzhautdicke nahm von 479μm ± 233 auf 242μm ± 60 ab (p = 0,08). Fazit: "Half-dose-PDT" ist eine sichere Behandlungsoption für Patienten mit chronischer CCS. Alle Patienten zeigten eine Abnahme der Netzhautdicke mit zum Teil vollständiger Resorption von subretinaler Flüssigkeit in 6Augen. Fünf Augen zeigten zusätzlich sowohl eine funktionelle als auch eine anatomische Verbesserung durch die Behandlun

Thermodynamically Stable One-Component Metallic Quasicrystals

Classical density-functional theory is employed to study finite-temperature trends in the relative stabilities of one-component quasicrystals interacting via effective metallic pair potentials derived from pseudopotential theory. Comparing the free energies of several periodic crystals and rational approximant models of quasicrystals over a range of pseudopotential parameters, thermodynamically stable quasicrystals are predicted for parameters approaching the limits of mechanical stability of the crystalline structures. The results support and significantly extend conclusions of previous ground-state lattice-sum studies.Comment: REVTeX, 13 pages + 2 figures, to appear, Europhys. Let

Precision Measurement of the 29Si, 33S, and 36Cl Binding Energies

The binding energies of 29Si, 33S, and 36Cl have been measured with a relative uncertainty $< 0.59 \times 10^{-6}$ using a flat-crystal spectrometer. The unique features of these measurements are 1) nearly perfect crystals whose lattice spacing is known in meters, 2) a highly precise angle scale that is derived from first principles, and 3) a gamma-ray measurement facility that is coupled to a high flux reactor with near-core source capability. The binding energy is obtained by measuring all gamma-rays in a cascade scheme connecting the capture and ground states. The measurements require the extension of precision flat-crystal diffraction techniques to the 5 to 6 MeV energy region, a significant precision measurement challenge. The binding energies determined from these gamma-ray measurements are consistent with recent highly accurate atomic mass measurements within a relative uncertainty of $4.3 \times 10^{-7}$. The gamma-ray measurement uncertainties are the dominant contributors to the uncertainty of this consistency test. The measured gamma-ray energies are in agreement with earlier precision gamma-ray measurements.Comment: 13 pages, 4 figure

The Portuguese S3-Non-invasive Ventilation (S3-NIV) questionnaire for home mechanically ventilated patients

Short, valid and easy to use tools are needed to monitor home mechanical ventilation (HMV) in clinical practice and for organization of HMV services. The S3NIV is a self-administered questionnaire containing 11 items that includes a Respiratory Symptoms and Sleep & Side Effects subscores, ranging from 0 (highest impact of disease and treatment) to 10 (lowest impact of disease and treatment). The Portuguese version of the questionnaire was obtained using translation-back translation process with two professional translators and it was then validated on 234 stable patients (128 male patients, 53.8%) with a mean age of 69.3 (SD 11.0) years under long-term home non-invasive ventilation. Data on total score and subscales according to disease category are reported on the table. Internal consistency for the total score was good (Cronbach’s α coefficient of 0.76) as well as for the Respiratory Symptoms and the Sleep & Side effects domains (Cronbach’s α coefficient=0.68 and Cronbach’s α coefficient=0.72, respectively). The Portuguese version of the S3-NIV questionnaire is a simple and valid tool for the routine clinical assessment of patients receiving HMV. Although they have advanced diseases, it appears patients recognize treatment benefits and have controlled side effects

Response to ranibizumab therapy in neovascular AMD - an evaluation of good and bad responders

Background: Treatment of neovascular age-related macular degeneration (AMD) with Lucentis® shows a broad spectrum regarding the course of visual acuity (VA). While some patients show a good response (increase in VA), others disclose much less promising results. Patients and Methods: A retrospective data analysis of all eyes treated for neovascular AMD at the University Hospital of Zurich, Switzerland for at least 12 months was carried out. The courses of VA between the 90th (good responders, GR) and the 10th (bad responders, BR) percentiles were compared at 3, 12 and 24 months from baseline. An analysis regarding demographic data, lesion type and size as well as injection frequency and visits was done and predictive factors for GR and BR were evaluated. Results: Marked differences in the course of VA between GR (n = 30) and BR (n = 30) are already observed 3 months from baseline. In GR the gains in VA after 3, 12 and 24 were 15.7 ± 9 letters ETDRS, 25.3 ± 7 and 14.0 ± 14. BR showed a deterioration of 8.3 ± 11 letters ETDRS after 3, 22.1 ± 8 after 12 and 23.6 ± 13 after 24 months. The gender distribution was equal with a higher percentage of female patients (64 % in BR and 66 % in GR). The baseline VA was statistically significantly lower in GR (45.7 ± 10 vs. 55.4 ± 11, p < 0.05) than in BR. No other significant differences in baseline data were found, and no predictor for group membership could be identified. Conclusions: Only the course of VA in the first three months seems to be of value for an estimation of the response to treatment. In the future the response to treatment in the early phase may influence the treatment algorithm and the injection frequency

Validation and discussion of clinical practicability of the 2022 graded prognostic assessment for NSCLC adenocarcinoma patients with brain metastases in a routine clinical cohort

IntroductionThe goal of this analysis is to validate the 2022 graded prognostic assessment (GPA) for patients with brain metastases from adenocarcinoma of the lung and to discuss its clinical practicability.Methods/material137 patients with adenocarcinoma of the lung were included in this analysis. The disease specific GPA for NSCLC, Lung-molGPA and the GPA for NSCLC adenocarcinoma were calculated. Overall survival was calculated for each GPA group. Additionally, expected and actual OS in the prognostic groups of the GPA available at the time of the patients’ diagnosis was compared.ResultsMedian overall survival (OS) from diagnosis of brain metastases was 15 months (95% confidence interval (CI) 9.7–20.3 months). The median OS in the three individual prognostic groups was 7 months for GPA 0-1, 16 months for GPA 1.5-2, 33 months for GPA 2.5-3 and not reached for GPA 3.5-4 (p&lt;0.001). Median survival times for the individual groups were similar to those published in the original GPA publication. Regarding the expected and actual OS when using the available GPA at the time of diagnosis there was an underestimation of survival of more than 3 months for all except the worst prognosis group.ConclusionWe were able to validate the 2022 GPA for NSCLC adenocarcinoma patients with brain metastases in a similar cohort from a non-academic center. However, the practical applicability regarding the expected median OS might be limited due to the constantly evolving treatment landscape and the consecutive improvement in overall survival

Transition-metal interactions in aluminum-rich intermetallics

The extension of the first-principles generalized pseudopotential theory (GPT) to transition-metal (TM) aluminides produces pair and many-body interactions that allow efficient calculations of total energies. In aluminum-rich systems treated at the pair-potential level, one practical limitation is a transition-metal over-binding that creates an unrealistic TM-TM attraction at short separations in the absence of balancing many-body contributions. Even with this limitation, the GPT pair potentials have been used effectively in total-energy calculations for Al-TM systems with TM atoms at separations greater than 4 AA. An additional potential term may be added for systems with shorter TM atom separations, formally folding repulsive contributions of the three- and higher-body interactions into the pair potentials, resulting in structure-dependent TM-TM potentials. Towards this end, we have performed numerical ab-initio total-energy calculations using VASP (Vienna Ab Initio Simulation Package) for an Al-Co-Ni compound in a particular quasicrystalline approximant structure. The results allow us to fit a short-ranged, many-body correction of the form a(r_0/r)^{b} to the GPT pair potentials for Co-Co, Co-Ni, and Ni-Ni interactions.Comment: 18 pages, 5 figures, submitted to PR