Strain-rate sensitivity of glasses

AbstractWe report on the loading-rate dependence of localized plastic deformation in inorganic covalent, metallic, ionic and superionic glasses. For this, the strain-rate sensitivity is determined through instrumented nanoindentation in a load-controlled strain-rate jump test. Through relating the strain-rate sensitivity to the reduced temperature, the packing density, the network dimensionality and the average single bond strength of the system, a qualitative mechanistic description of the strain-mediating process is possible. A strong variability of strain-rate sensitivity is obtained only at intermediate values of packing density, network connectivity or bond strength, when other parameters such as chemical composition and specific structural arrangement are dominating the deformation process. On the other side, for high bond strength and connectivity or for high packing density, the strain-rate sensitivity of the considered glasses is always low, which is also confirmed through the dependence of strain-rate sensitivity on Poisson ratio. Here, only for glasses with a Poisson ratio of ~0.3–0.4 we observe a wide variability of the loading-rate dependence of local deformation. For higher or lower Poisson ratio, the observed dependence is always low: when the limiting factor in deformation is primarily network connectivity and bond strength or packing density, respectively, once an activation barrier is overcome, deformation is only weakly loading-rate-dependent. This is regardless of the height of the activation barrier. When approaching the glass transition temperature, high strain-rate sensitivity is observed only in glasses where non-Newtonian flow is expected also in the corresponding liquid

Quantitative Bestimmung von Phosphonaten in Waschmitteln

The selective determination of phosphonates in detergents with ion chromatography is disturbed by the presence of Al or other metal ions. Due to the formation of stable metal-phosphonate complexes, phosphonate is linked and thus a determination is not possible. The disturbance caused by AlIII can be eliminated by adding a competing agent to the analyte solution

Population-based SEER trend analysis of overall and cancer-specific survival in 5138 patients with gastrointestinal stromal tumor

Background: The objective of the present population-based analysis was to assess survival patterns in patients with resected and metastatic GIST. Methods: Patients with histologically proven GIST were extracted from the Surveillance, Epidemiology and End Results (SEER) database from 1998 through 2011. Survival was determined applying Kaplan-Meier-estimates and multivariable Cox-regression analyses. The impact of size and mitotic count on survival was assessed with a generalized receiver-operating characteristic-analysis. Results: Overall, 5138 patients were included. Median age was 62 years (range: 18–101 years), 47.3% were female, 68.8% Caucasians. GIST location was in the stomach in 58.7% and small bowel in 31.2%. Lymph node and distant metastases were found in 5.1 and 18.0%, respectively. For non-metastatic GIST, three-year overall survival increased from 68.5% (95% CI: 58.8–79.8%) in 1998 to 88.6% (95% CI: 85.3–92.0%) in 2008, cancer-specific survival from 75.3% (95% CI: 66.1–85.9%) in 1998 to 92.2% (95% CI: 89.4–95.1%) in 2008. For metastatic GIST, three-year overall survival increased from 15.0% (95% CI: 5.3–42.6%) in 1998 to 54.7% (95% CI: 44.4–67.3%) in 2008, cancer-specific survival from 15.0% (95% CI: 5.3–42.6%) in 1998 to 61.9% (95% CI: 51.4–74.5%) in 2008 (all PTrend < 0.05). Conclusions: This is the first SEER trend analysis assessing outcomes in a large cohort of GIST patients over a 11-year time period. The analysis provides compelling evidence of a statistically significant and clinically relevant increase in overall and cancer-specific survival from 1998 to 2008, both for resected as well as metastatic GIST

The reversal of the SF-density relation in a massive, X-ray selected galaxy cluster at z=1.58: results from Herschel

Dusty, star-forming galaxies have a critical role in the formation and evolution of massive galaxies in the Universe. Using deep far-infrared imaging in the range 100-500um obtained with the Herschel telescope, we investigate the dust-obscured star formation in the galaxy cluster XDCP J0044.0-2033 at z=1.58, the most massive cluster at z >1.5, with a measured mass M200= 4.7x10$^{14}$ Msun. We perform an analysis of the spectral energy distributions (SEDs) of 12 cluster members (5 spectroscopically confirmed) detected with >3$\sigma$ significance in the PACS maps, all ULIRGs. The individual star formation rates (SFRs) lie in the range 155-824 Ms/yr, with dust temperatures of 24$\pm$35 K. We measure a strikingly high amount of star formation (SF) in the cluster core, SFR ( 1875$\pm$158 Ms/yr, 4x higher than the amount of star formation in the cluster outskirts. This scenario is unprecedented in a galaxy cluster, showing for the first time a reversal of the SF-density relation at z~1.6 in a massive cluster.Comment: Letter accepted for publication in MNRAS, ESA Press Release on 18 December 201

Direct Visualization and Silver Enhancement of Ultra-Small Antibody-Bound Gold Particles on Immunolabeled Ultrathin Resin Sections

Ultra-small gold colloids bound to immunolabeled ultrathin resin sections were visualized using transmission, scanning, and scanning transmission electron microscopy (TEM, SEM, STEM). The best marker contrast is obtained in a field emission STEM (200 kV) equipped with a high-angle annular dark-field (HAADF) detector. HAADF STEM renders possible the simultaneous visualization of ultra-small gold and ultrastructural details in unstained resin sections, and an overall presentation of a labeled E. coli cell. For routine work, an enhancement step is a prerequisite for easy detection of bound marker molecules. Five different silver enhancing solutions were tested for their suitability for ultra-small gold intensification. Enhancers lacking the protective colloid gum arabic exhibit lower quality with regard to efficiency and homogeneity of enhancement. This problem can be overcome by adding gum arabic. Silver enhancement generally results in heterogeneously sized particles. This is most probably due to the heterogeneous original gold colloid probe. In general, an estimation of enhancement efficiency is associated with difficulties depending on experimental conditions and the electron microscopic imaging modes used. Only a low number of the ultra-small gold particles seems to remain unenhanced or poorly enhanced when treated with high-quality enhancers. On-section labeling of ultrathin resin sections with silver-enhanced ultra-small gold markers also offers the possibility of high-resolution immunolabeling experiments at the light microscopic level

Diagnostic study and meta-analysis of C-reactive protein as a predictor of postoperative inflammatory complications after gastroesophageal cancer surgery

Purpose: This study assessed the diagnostic accuracy of C-reactive protein (CRP) after gastroesophageal cancer resection for postoperative inflammatory complications (PIC). Methods: The clinical data and CRP values of patients operated on for gastroesophageal cancer surgery between 1997 and 2009 were retrospectively analyzed. The results of this study were compared with published data using a meta-analytic approach for diagnostic outcomes. Results: Of 210 patients included in the study, 59 developed PIC (28.1%; 95% CI: 22.5-34.5%). On the postoperative day (POD) 4 and 7, CRP had the best diagnostic accuracy for PIC (AUC 0.77; 95% CI, 0.64-0.91, AUC 0.81; 95% CI, 0.71-0.91). Using a cut-off value of 141mg/L (95% CI, 131-278mg/L) for CRP on POD 4, the sensitivity was 0.78 (95% CI, 0.55-0.91), the specificity was 0.70 (95% CI, 0.53-0.83) and the NPV was 0.89 (95% CI, 0.77-0.95). The in-hospital mortality rate was 3.3% (95% CI, 1.5-6.9%). In a diagnostic meta-analysis that included two additional studies, CRP had a significant predictive value after POD 3. Conclusion: There is limited evidence for the diagnostic accuracy of CRP levels for PIC after gastroesophageal cancer surgery. CRP levels on POD 4 might be useful to rule out PIC, but its diagnostic accuracy is moderate at best. For clinical routine use CRP levels are clearly not sufficient to predict PIC and have to be interpreted in the context of the whole clinical pictur

In Vitro Comparison of Novel Polyurethane Aortic Valves and Homografts After Seeding and Conditioning

The aim of the study was to compare the behavior of seeded cells on synthetic and natural aortic valve scaffolds during a low-flow conditioning period. Polyurethane (group A) and aortic homograft valves (group B) were consecutively seeded with human fibroblasts (FB), and endothelial cells (EC) using a rotating seeding device. Each seeding procedure was followed by an exposure to low pulsatile flow in a dynamic bioreactor for 5 days. For further analysis, samples were taken before and after conditioning. Scanning electron microscopy showed confluent cell layers in both groups. Immunohistochemical analysis showed the presence of EC and FB before and after conditioning as well as the establishment of an extracellular matrix (ECM) during conditioning. A higher expression of ECM was observed on the scaffolds' inner surface. Real-time polymerase chain reaction showed higher inflammatory response during the conditioning of homografts. Endothelialization caused a decrease in inflammatory gene expression. The efficient colonization, the establishment of an ECM, and the comparable inflammatory cell reaction to the scaffolds in both groups proved the biocompatibility of the synthetic scaffold. The newly developed bioreactor permits conditioning and cell adaption to shear stress. Therefore, polyurethane valve scaffolds may offer a new option for aortic valve replacement

C-Reactive Protein 2 Days After Laparoscopic Gastric Bypass Surgery Reliably Indicates Leaks and Moderately Predicts Morbidity

Background: The aim of the present study was to evaluate whether serum C-reactive protein (CRP) is a useful predictor of early post-operative complications, particularly of intestinal leaks after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. Methods: The present study was a retrospective analysis of a prospectively maintained database with 809 patients who underwent LRYGB from 2002 until 2011. For 410 of these patients, at least one CRP measurement within the first seven post-operative days was available. The diagnostic value was determined by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. Results: Forty-nine of 410 patients (12.0%; 95% confidence intervals [95% CI], 9.2-15.5%) developed surgery-related complications. Leaks occurred in 17 patients (4.1%; 95% CI, 2.6-6.5%) at a median of 5days after surgery. CRP levels 2days after surgery showed the highest diagnostic value for post-operative complications (AUC, 0.74; 95% CI, 0.60-0.89). Sensitivity was 0.53 (95% CI, 0.31-0.74) and specificity was 0.91 (95% CI, 0.79-0.96) on day 2 (cutoff level, 229mg/l). The sensitivity for intestinal leaks was 1.00 (95% CI, 0.51-1.00). Conclusion: CRP on post-operative day 2 is a valuable predictor of post-operative complications, in particular intestinal leaks. Radiological imaging studies for intestinal leaks could be restricted to patients with CRP values exceeding 229mg/

Relative survival is an adequate estimate of cancer-specific survival: baseline mortality-adjusted 10-year survival of 771 rectal cancer patients.

BACKGROUND The objective of the present investigation is to assess the baseline mortality-adjusted 10-year survival of rectal cancer patients. METHODS Ten-year survival was analyzed in 771 consecutive American Joint Committee on Cancer (AJCC) stage I-IV rectal cancer patients undergoing open resection between 1991 and 2008 using risk-adjusted Cox proportional hazard regression models adjusting for population-based baseline mortality. RESULTS The median follow-up of patients alive was 8.8 years. The 10-year relative, overall, and cancer-specific survival were 66.5% [95% confidence interval (CI) 61.3-72.1], 48.7% (95% CI 44.9-52.8), and 66.4% (95% CI 62.5-70.5), respectively. In the entire patient sample (stage I-IV) 47.3% and in patients with stage I-III 33.6 % of all deaths were related to rectal cancer during the 10-year period. For patients with AJCC stage I rectal cancer, the 10-year overall survival was 96% and did not significantly differ from an average population after matching for gender, age, and calendar year (p = 0.151). For the more advanced tumor stages, however, survival was significantly impaired (p < 0.001). CONCLUSIONS Retrospective investigations of survival after rectal cancer resection should adjust for baseline mortality because a large fraction of deaths is not cancer related. Stage I rectal cancer patients, compared to patients with more advanced disease stages, have a relative survival close to 100% and can thus be considered cured. Using this relative-survival approach, the real public health burden caused by rectal cancer can reliably be analyzed and reported