The quantum paraelectric behavior of SrTiO_{3} revisited: relevance of the structural phase transition temperature

It has been known for a long time that the low temperature behavior shown by the dielectric constant of quantum paraelectric $SrTiO_{3}$ can not be fitted properly by Barrett's formula using a single zero point energy or saturation temperature ($T_{1}$). As it was originally shown [K. A. M\"{u}ller and H. Burkard, Phys. Rev. B {\bf 19}, 3593 (1979)] a crossover between two different saturation temperatures ($T_{1l}$=77.8K and $T_{1h}$=80K) at $T\sim10K$ is needed to explain the low and high temperature behavior of the dielectric constant. However, the physical reason for the crossover between these two particular values of the saturation temperature at $T\sim10K$ is unknown. In this work we show that the crossover between these two values of the saturation temperature at $T\sim10K$ can be taken as a direct consequence of (i) the quantum distribution of frequencies $g(\Omega)\propto\Omega^{2}$ associated with the complete set of low-lying modes and (ii) the existence of a definite maximum phonon frequency given by the structural transition critical temperature $T_{tr}$.Comment: 8 pages, 3 figure

Ovarian cancer in Switzerland : incidence and treatment according to hospital registry data

Objective: The methods used to diagnose and classify ovarian cancer have changed over the past decade. We used hospital registry data to assess the incidence, treatment durations and hospital costs of ovarian cancer in Switzerland. Methods: We carried out a retrospective analysis of a hospital registry covering all inpatient care episodes in Switzerland between 1998 and 2012. Ovarian cancer incidence was assessed by identifying patients with a first ovarian cancer diagnosis as the main reason for hospital stay after an event-free period. We assessed the duration and cost of ovarian cancer treatment sequences as well as the evolution of hospital patient volume over time. Results: The average age-adjusted incidence rate was 14.6 per 100,000 women per year between 2004 and 2012. This rate is substantially higher (+35.5%) than the corresponding rate published by the National Institute for Cancer Epidemiology and Registration (NICER). Hospital patient volume was low in most cases, with more than 40% of patients treated in hospitals with fewer than 20 cases per year. However, the share of patients treated in hospitals with more than 30 cases per year has increased substantially since 2009. Conclusions: We found a substantial difference between the ovarian cancer incidence estimate based on hospital registry data and the corresponding estimate by NICER. The reasons for this substantial difference should be carefully explored. A case-wise comparison could determine whether the difference is due to over- or under-reporting in one of the two registries. The low ovarian cancer patient volume in many hospitals is in conflict with the numbers required for certified specialised cancer centres. The recent increase in patient volume in specialised cancer centres, however, might reflect a growing understanding of the needs and requirements of comprehensive cancer care

Self-perceived oral health and orofacial aesthetics of cleft patients

Purpose: To evaluate the self-perceived oral health and aesthetics of the dentition and jaw in patients with different types of oral cleft, measured by patient-reported outcome measures (PROMs). Additionally, to compare the results of the PROMs between cleft lip and or/palate (CL/P) patients and non-affected controls. Methods: 420 CL/P patients treated at the cleft team of the Erasmus Medical Center, Rotterdam, The Netherlands, were included, and 138 non-cleft patients were recruited as control-group. Patient’s perceptions were retrospectively evaluated using the CLEFT-Q Teeth for dental aesthetics at ages 8, 12 and 22, CLEFT-Q Jaw for jaw aesthetics at ages 12 and 22, and the Child Oral Health Impact Profile—Oral Symptoms Subscale (COHIP-OSS) for oral health at ages 8 and 12. One-way ANOVA was used to compare differences in oral health and aesthetic perceptions among age-groups, cleft types, as well as between cases and controls. Results: CL/P patients were significantly less satisfied than controls with their dental aesthetics (p = 0.001). CL/P patients reported significantly lower satisfaction on CLEFT-Q Teeth scores at ages 8 and 12, than at 22 years (p &lt; 0.001). Patients with the most extensive cleft phenotype, Cleft Lip and Palate (CLAP), reported lowest satisfaction on the CLEFT-Q Teeth. No differences in perceptions of oral health nor in aesthetics of the jaw were found in the different cleft types, ages, nor in study versus control group. Conclusion: This study found differences in self-perceived dental aesthetics: CL/P patients are less satisfied than non-affected controls. CLAP patients are least satisfied, but satisfaction increases with age.</p

Self-perceived oral health and orofacial aesthetics of cleft patients

Purpose: To evaluate the self-perceived oral health and aesthetics of the dentition and jaw in patients with different types of oral cleft, measured by patient-reported outcome measures (PROMs). Additionally, to compare the results of the PROMs between cleft lip and or/palate (CL/P) patients and non-affected controls. Methods: 420 CL/P patients treated at the cleft team of the Erasmus Medical Center, Rotterdam, The Netherlands, were included, and 138 non-cleft patients were recruited as control-group. Patient’s perceptions were retrospectively evaluated using the CLEFT-Q Teeth for dental aesthetics at ages 8, 12 and 22, CLEFT-Q Jaw for jaw aesthetics at ages 12 and 22, and the Child Oral Health Impact Profile—Oral Symptoms Subscale (COHIP-OSS) for oral health at ages 8 and 12. One-way ANOVA was used to compare differences in oral health and aesthetic perceptions among age-groups, cleft types, as well as between cases and controls. Results: CL/P patients were significantly less satisfied than controls with their dental aesthetics (p = 0.001). CL/P patients reported significantly lower satisfaction on CLEFT-Q Teeth scores at ages 8 and 12, than at 22 years (p &lt; 0.001). Patients with the most extensive cleft phenotype, Cleft Lip and Palate (CLAP), reported lowest satisfaction on the CLEFT-Q Teeth. No differences in perceptions of oral health nor in aesthetics of the jaw were found in the different cleft types, ages, nor in study versus control group. Conclusion: This study found differences in self-perceived dental aesthetics: CL/P patients are less satisfied than non-affected controls. CLAP patients are least satisfied, but satisfaction increases with age.</p

Competition in the postsynaptic density for PDZ domains of PSD-95

Molecular mechanisms of synaptic plasticity are of great interest because derangement of synaptic plasticity contributes to neural diseases such as autism, schizophrenia, cognitive impairment, neuropathic pain, epilepsy, and stroke. This work addresses the molecular mechanisms underlying NMDA‐type glutamate receptor‐triggered plasticity at excitatory synapses. A critical step in this process is a change in the rate of trapping of AMPA‐type receptors (AMPARs) in the postsynaptic density (PSD), which increases the number of AMPARs and strengthens the electrical signal at the synapse. Our work aims to determine whether trapping of AMPARs in the PSD is mediated by rearrangement of the PSD scaffold caused by changes in the affinity of different PSD proteins for the PDZ domains of the major synaptic scaffold protein, PSD‐95. Our earlier publication (1) supports this notion by showing that: 1. Phosphorylation of the abundant PSD protein synGAP by CaMKII reduces its affinity for the PDZ domains of PSD‐95; and 2. The composition of the PSD is altered in synGAP deficient mice such that AMPAR-binding proteins with PDZ ligands, including TARPs and LRRTM2, are increased in concentration relative to PSD‐95. We have now replicated these finding in synGAP‐deficient rats. These findings suggest that the extent of binding of particular synaptic proteins to the PDZ domains of PSD‐95 is regulated by activity‐dependent phosphorylation of synGAP. We are testing this hypothesis in cultured rat neurons. We have isolated PSDs from neuronal cultures before and after induction of synGAP phosphorylation by pharmacological activation of NMDARs. The ratios of AMPAR‐associated proteins to PSD‐95 in the PSDs are determined by quantitative immunoblotting. We have found that the ratio of TARPs to PSD‐95 is consistently increased in PSDs after chemical activation of synaptic NMDARs. We are using cultures from synGAP‐deficient rats to determine if synGAP deficiency alters the composition of the PSD in rat cultures. We plan to transfect with a variety of synGAP mutant proteins in order to determine which domains or phosphorylation sites on synGAP are important for regulating PSD composition

Ultra-fast searching assists in evaluating sub-ppm mass accuracy enhancement in U-HPLC/Orbitrap MS data

A strategy, detailed methodology description and software are given with which the mass accuracy of U-HPLC-Orbitrap data (resolving power 50,000 FWHM) can be enhanced by an order of magnitude to sub-ppm levels. After mass accuracy enhancement all 211 reference masses have mass errors within 0.5 ppm; only 14 of these are outside the 0.2 ppm error margin. Further demonstration of mass accuracy enhancement is shown on a pre-concentrated urine sample in which evidence for 89 (342 ions) potential hydroxylated and glucuronated DHEA-metabolites is found. Although most DHEA metabolites have low-intensity mass signals, only 11 out of 342 are outside the ±1 ppm error envelop; 272 mass signals have errors below 0.5 ppm (142 below 0.2 ppm). The methodology consists of: (a) a multiple internal lock correction (here ten masses; no identity of internal lock masses is required) to avoid suppression problems of a single internal lock mass as well as to increase lock precision, (b) a multiple external mass correction (here 211 masses) to correct for calibration errors, (c) intensity dependant mass correction, (d) file averaging. The strategy is supported by ultra-fast file searching of baseline corrected, noise-reduced metAlign output. The output and efficiency of ultra-fast searching is essential in obtaining the required information to visualize the distribution of mass errors and isotope ratio deviations as a function of mass and intensity