Statische Kontraktionsspannung und Härtebestimmung bei unterschiedlichen Polymerisationskonzepten

Auswirkung verschiedener Polymerisationskonzepte von Halogen- bzw. LED-Lampen auf die Kontraktionsspannung im Komposit Mit dieser Untersuchung soll das Ziel verfolgt werden, Aussagen über die statische Kontraktionsspannung in ein und demselben Komposit, unter dem Einfluss verschiedener Polymerisationskonzepte diverser Lichtquellen, zu treffen. Dabei ist es wichtig, eine möglichst vollständige Durchhärtung in allen Schichten, eine hohe Konversionsrate des Monomers bei möglichst geringen Spannungszuständen im Komposit, in einer für die Praxis vernünftigen Belichtungszeit, zu erreichen. Somit wurden im ersten Teil dieser Studie die Lichtkonzepte zweier verschiedener sich auf dem Markt befindlichen Halogen-Lampen (Astralis 10 und Elipar Trilight), sowie zweier verschiedener LED-Lampen (Elipar Freelight und GC e-light) verglichen, wobei letztere einen Prototyp darstellte. Es wurden zunächst alle Konzepte in einem statischen Polymerisationsschrumpfverfahren über 300 s ohne Kompensation untersucht. Es stellte sich heraus, dass die Konzepte mit der größten Lichtintensität – beide Halogen-Lampen - auch die höchsten Spannungen im Komposit aufwiesen. Die niedrigsten Spannungen wiesen die verschiedenen Konzepte der LED-GC e-light auf. Trotz einer weiteren Belichtung der Konzepte dieser Lampe von 40 s mit 400mW/cm², wurden nach insgesamt 460 gemessenen Sekunden nochmals eine deutliche Steigerung der Spannungswerte erbracht, wobei aber die Werte der Halogen-Lampe Astralis 10 nicht erreicht werden konnten. Eine Belichtung mit sehr hoher Intensität von Anfang an bewirkt demnach eine sehr große Schrumpfung und Spannungsbildung im Komposit, das auf den adhäsiven Verbund negative Auswirkungen hat. Auffallend ist, dass alle Lampen, deren Konzepte einen exponentiellen Verlauf haben, die niedrigsten Werte aufwiesen. Durch die daher herabgesetzte Polymerisationsgeschwindigkeit wird das Nachfließen des Materials verlängert, wodurch bis zum Erreichen des Gelpunktes innere Spannungen im Komposit - bei einem höheren Vernetzungsgrad - abgebaut werden können. Ein spannungsreduzierender Effekt wurde somit nachweisbar. Der zweite Teil der Studie beschäftigte sich sowohl mit der Durchhärtung an der Oberfläche, als auch der Härte in 2 mm Tiefe, da dieser Wert als ideale Schichtstärke angesehen wird. Um die Durchhärtungswerte zu bestimmen, wurde als indirektes Maß die Härtemessung nach Vickers durchgeführt. Die Versuche zeigten eine Abhängigkeit des Polymerisationsgrades der Proben von der Polymerisationsdauer, sowie Intensität innerhalb der vergleichbaren Konzepte und der Art der Polymerisationsgeräte. Dabei erreichten beide LED-Lampen die geringsten Härtewerte. Das beste Ergebnis für eine relativ kurze Belichtungszeit von 24 s bei einer geringen Schrumpfspannung und einer guten Aushärtung - selbst an der Unterseite der Probe - zeigte das Pulse 10.2-Konzept der GC e-light. Einzig eine Ausnahme im Vergleich zu den übrigen Lampen bildet das Soft A-Konzept der GC e-light. Allein durch die Belichtungzeit von 40 s war hier eine ausreichende Tiefenaushärtung gewährleistet. Der Vergleich beider Halogen-Lampen zeigt bei der Astralis 10 generell größere Durchhärtungsergebnisse als bei vergleichbaren Konzepten der Elipar Trilight, was auf die sehr hohe Anfangsintensität zurückzuführen ist. Die Werte an der Ober- bzw. Unterseite verhielten sich signifikant untereinander. Aufgrund der höheren Schrumpfspannungen aber auch der größeren Tiefendurchhärtung der Halogen-Lampen im Vergleich zu den LED-Lampen, ist zum jetzigen technischen Entwicklungszeitpunkt dieser hier verwendeten Lampen keine Empfehlung für einen bestimmten Lampentyp auszusprechen

Clinical prediction model to identify vulnerable patients in ambulatory surgery: towards optimal medical decision-making

__Background:__ Ambulatory surgery patients are at risk of adverse psychological outcomes such as anxiety, aggression, fatigue, and depression. We developed and validated a clinical prediction model to identify patients who were vulnerable to these psychological outcome parameters. __Methods:__ We prospectively assessed 383 mixed ambulatory surgery patients for psychological vulnerability, defined as the presence of anxiety (state/trait), aggression (state/trait), fatigue, and depression seven days after surgery. Three psychological vulnerability categories were considered–i.e., none, one, or multiple poor scores, defined as a score exceeding one standard deviation above the mean for each single outcome according to normative data. The following determinants were assessed preoperatively: sociodemographic (age, sex, level of education, employment status, marital status, having children, religion, nationality), medical (heart rate and body mass index), and psychological variables (self-esteem and self-efficacy), in addition to anxiety, aggression, fatigue, and depression. A prediction model was constructed using ordinal polytomous logistic regression analysis, and bootstrapping was applied for internal validation. The ordinal c-index (ORC) quantified the discriminative ability of the model, in addition to measures for overall model performance (Nagelkerke’s R2). __Results:__ In this population, 137 (36%) patients were identified as being psychologically vulnerable after surgery for at least one of the psychological outcomes. The most parsimonious and optimal prediction model combined sociodemographic variables (level of education, having children, and nationality) with psychological variables (trait anxiety, state/trait aggression, fatigue, and depression). Model performance was promising: R2 = 30% and ORC = 0.76 after correction for optimism. __Conclusion:__ This study identified a substantial group of vulnerable patients in ambulatory surgery. The proposed clinical prediction model could allow healthcare professionals the opportunity to identify vulnerable patients in ambulatory surgery, although additional modification and validation are needed. (ClinicalTrials.gov number, NCT01441843)

The microscopic spin-phonon coupling constants in CuGeO_3

Using RPA results, mean field theory, and refined data for the polarization vectors we determine the coupling constants of the four Peierls-active phonon modes to the spin chains of CuGeO_3. We then derive the values of the coupling of the spin system to the linear ionic displacements, the bond lengths and the angles between bonds. Our values are consistent with microscopic theories and various experimental results. We discuss the applicability of static approaches to the spin-phonon coupling. The c-axis anomaly of the thermal expansion is explained. We give the values of the coupling constants in an effective one-dimensional Hamiltonian.Comment: 11 pages, two figures, 13 tables, PRB 59 (in press

Forward K+ production in subthreshold pA collisions at 1.0 GeV

K+ meson production in pA (A = C, Cu, Au) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-Juelich accelerator. The complete momentum spectrum of kaons emitted at forward angles, theta < 12 degrees, has been measured for a beam energy of T(p)=1.0 GeV, far below the free NN threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger momenta reflect a high degree of collectivity in the target nucleus.Comment: 4 pages, 3 figure

Focus on fatigue amongst young adults with spastic cerebral palsy

Background: This study aimed to assess fatigue amongst young adults with spastic cerebral palsy (CP), to determine subgroups at risk for fatigue and to explore the relationship between fatigue and cardiopulmonary fitness and daily physical activity level. Participants: Young adults with spastic CP, Gross Motor Function Classification System (GMFCS) levels I to III, aged 16 to 24 years. Methods: Fatigue (Fatigue Severity Scale) and self-reported daily physical activity (Physical Activity Scale for Individuals with Physical Disabilities) were assessed for 56 participants using questionnaires. Daily physical activity was objectively measured using accelerometry (Vitamove system) over 72 hours. Progressive maximal aerobic cycling was used to measure cardiopulmonary fitness. Results: The mean Fatigue Severity Scale (FSS) score was 3.7 (SD 1.4). Forty percent of participants were fatigued, including 12.5% who were severely fatigued. Participants with bilateral CP (FSS = 4.2 (SD 1.4)) were more fatigued compared to those with unilateral CP (FSS = 3.1 (SD 1.3)) (p < 0.01). Levels of cardiopulmonary fitness (2.4 L/min (SD 0.8)) and daily physical activity (8.5% (SD 3.0)) were not significantly related to fatigue (respectively p = 0.10 and p = 0.55), although for cardiopulmonary fitness a trend was found. Conclusions: Fatigue is already present at a relatively young age amongst adults with CP, and CP subtype is a determinant of fatigue. We did not find significant evidence for a cross-sectional relation of fatigue with cardiopulmonary fitness or daily physical activity. Trial registration: Nederland's trial register: NTR1785

Phenethylamine-derived new psychoactive substances 2C-E-FLY, 2C-EF-FLY, and 2C-T-7-FLY: Investigations on their metabolic fate including isoenzyme activities and their toxicological detectability in urine screenings

Psychoactive substances of the 2C-series are phenethylamine-based designer drugs that can induce psychostimulant and hallucinogenic effects. The so-called 2C-FLY series contains rigidified methoxy groups integrated in a 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran core. The aim of the presented work was to investigate the in vivo and in vitro metabolic fate including isoenzyme activities and toxicological detectability of the three new psychoactive substances (NPS) 2C-E-FLY, 2C-EF-FLY, and 2C-T-7-FLY to allow clinical and forensic toxicologists the identification of these novel compounds. Rat urine, after oral administration, and pooled human liver S9 fraction (pS9) incubations were analyzed by liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS). By performing activity screenings, the human isoenzymes involved were identified and toxicological detectability in rat urine investigated using standard urine screening approaches (SUSAs) based on gas chromatography (GC)-MS, LC-MSn, and LC-HRMS/MS. In total, 32 metabolites were tentatively identified. Main metabolic steps consisted of hydroxylation and N acetylation. Phase I metabolic reactions were catalyzed by CYP2D6, 3A4, and FMO3 and N-acetylation by NAT1 and 2. Methoxyamine was used as a trapping agent for detection of the deaminated metabolite formed by MAO-A and B. Interindividual differences in the metabolism of the 2C-FLY drugs could be caused by polymorphisms of enzymes involved or drug-drug interactions. All three SUSAs were shown to be suitable to detect an intake of these NPS but common metabolites of 2C-E-FLY and 2C-EF-FLY have to be considered during interpretation of analytical findings

Percolation thresholds in chemical disordered excitable media

The behavior of chemical waves advancing through a disordered excitable medium is investigated in terms of percolation theory and autowave properties in the framework of the light-sensitive Belousov-Zhabotinsky reaction. By controlling the number of sites with a given illumination, different percolation thresholds for propagation are observed, which depend on the relative wave transmittances of the two-state medium considered

Bosutinib in Resistant and Intolerant Pediatric Patients With Chronic Phase Chronic Myeloid Leukemia:Results From the Phase I Part of Study ITCC054/COG AAML1921

PURPOSE Bosutinib is approved for adults with chronic myeloid leukemia (CML): 400 mg once daily in newly diagnosed (ND); 500 mg once daily in resistant/intolerant (R/I) patients. Bosutinib has a different tolerability profile than other tyrosine kinase inhibitors (TKIs) and potentially less impact on growth (preclinical data). The primary objective of this first-in-child trial was to determine the recommended phase II dose (RP2D) for pediatric R/I and ND patients. PATIENTS AND METHODS In the phase I part of this international, open-label trial (ClinicalTrials.gov identifier: NCT04258943), children age 1-18 years with R/I (per European LeukemiaNet 2013) Ph+ CML were enrolled using a 6 + 4 design, testing 300, 350, and 400 mg/m2 once daily with food. The RP2D was the dose resulting in 0/6 or 1/10 dose-limiting toxicities (DLTs) during the first cycle and achieving adult target AUC levels for the respective indication. As ND participants were only enrolled in phase II, the ND RP2D was selected based on data from R/I patients. Results Thirty patients were enrolled; 27 were evaluable for DLT: six at 300 mg/m2, 11 at 350 mg/m2 (one DLT), and 10 at 400 mg/m2 (one DLT). The mean AUCs at 300 mg/m2, 350 mg/m2, and 400 mg/m2 were 2.20 g h/mL, 2.52 g h/mL, and 2.66 g h/mL, respectively. The most common adverse event was diarrhea (93%; ≥grade 3: 11%). Seven patients stopped because of intolerance and eight because of insufficient response. Complete cytogenetic and major molecular response to bosutinib appeared comparable with other published phase I/II trials with second-generation TKIs in children. CONCLUSION Bosutinib was safe and effective. The pediatric RP2D was 400 mg/m2 once daily (max 600 mg/d) with food in R/I patients and 300 mg/m2 once daily (max 500 mg/d) with food in ND patients, which achieved targeted exposures as per adult experience.</p

Bosutinib in Resistant and Intolerant Pediatric Patients With Chronic Phase Chronic Myeloid Leukemia:Results From the Phase I Part of Study ITCC054/COG AAML1921

PURPOSE Bosutinib is approved for adults with chronic myeloid leukemia (CML): 400 mg once daily in newly diagnosed (ND); 500 mg once daily in resistant/intolerant (R/I) patients. Bosutinib has a different tolerability profile than other tyrosine kinase inhibitors (TKIs) and potentially less impact on growth (preclinical data). The primary objective of this first-in-child trial was to determine the recommended phase II dose (RP2D) for pediatric R/I and ND patients. PATIENTS AND METHODS In the phase I part of this international, open-label trial (ClinicalTrials.gov identifier: NCT04258943), children age 1-18 years with R/I (per European LeukemiaNet 2013) Ph+ CML were enrolled using a 6 + 4 design, testing 300, 350, and 400 mg/m2 once daily with food. The RP2D was the dose resulting in 0/6 or 1/10 dose-limiting toxicities (DLTs) during the first cycle and achieving adult target AUC levels for the respective indication. As ND participants were only enrolled in phase II, the ND RP2D was selected based on data from R/I patients. Results Thirty patients were enrolled; 27 were evaluable for DLT: six at 300 mg/m2, 11 at 350 mg/m2 (one DLT), and 10 at 400 mg/m2 (one DLT). The mean AUCs at 300 mg/m2, 350 mg/m2, and 400 mg/m2 were 2.20 g h/mL, 2.52 g h/mL, and 2.66 g h/mL, respectively. The most common adverse event was diarrhea (93%; ≥grade 3: 11%). Seven patients stopped because of intolerance and eight because of insufficient response. Complete cytogenetic and major molecular response to bosutinib appeared comparable with other published phase I/II trials with second-generation TKIs in children. CONCLUSION Bosutinib was safe and effective. The pediatric RP2D was 400 mg/m2 once daily (max 600 mg/d) with food in R/I patients and 300 mg/m2 once daily (max 500 mg/d) with food in ND patients, which achieved targeted exposures as per adult experience.</p

Cell Specific eQTL Analysis without Sorting Cells

The functional consequences of trait associated SNPs are often investigated using expression quantitative trait locus (eQTL) mapping. While trait-associated variants may operate in a cell-type specific manner, eQTL datasets for such cell-types may not always be available. We performed a genome-environment interaction (GxE) meta-analysis on data from 5,683 samples to infer the cell type specificity of whole blood cis-eQTLs. We demonstrate that this method is able to predict neutrophil and lymphocyte specific cis-eQTLs and replicate these predictions in independent cell-type specific datasets. Finally, we show that SNPs associated with Crohn’s disease preferentially affect gene expression within neutrophils, including the archetypal NOD2 locus