69 research outputs found

    v-K-data for silica from lifetime measurements under step-shaped loading history

    Get PDF
    Different methods were applied so far in order to determine subcritical crack growth for silica. Mostly, fracture mechanics standard tests with macro cracks were used for this purpose. In this report, we evaluated the subcritical crack growth curves from lifetime tests on silica bending specimens. The survivors were then tested under increased stress. Crack growth rates down to v=1012^{-12}m/s were reached in this way. In the plot of v=f(K/KIc_{Ic}) slight material differences could be eliminated and suitable agreement with macro-crack results by Wiederhorn and Bolz [1] on DCB-specimens and Michalske et al. [2] on DCDC-specimens could be stated

    High power, high repetition rate laser-based sources for attosecond science

    Get PDF
    Within the last two decades attosecond science has been established as a novel research field providing insights into the ultrafast electron dynamics that follows a photoexcitation or photoionization process. Enabled by technological advances in ultrafast laser amplifiers, attosecond science has been in turn, a powerful engine driving the development of novel sources of intense ultrafast laser pulses. This article focuses on the development of high repetition rate laser-based sources delivering high energy pulses with a duration of only a few optical cycles, for applications in attosecond science. In particular, a high power, high repetition rate optical parametric chirped pulse amplification system is described, which was developed to drive an attosecond pump-probe beamline targeting photoionization experiments with electron-ion coincidence detection at high acquisition rates

    Bilayered Glass-Ceramics as Sealants for SOFCs

    No full text
    Glass-ceramics are often used as sealants in solid oxide fuel cells (SOFC). But interfacing components, such as ferriticstainless steel and YSZ electrolyte, may vary in their requirements regarding sealing properties, especially in terms of thermalexpansion. A bilayered glass-ceramic system was developed to overcome the mismatch in coefficients of thermal expansion (CTE)between ferritic steel and YSZ. Therefore, two different glass-ceramics with slightly different CTEs were developed, one with goodbonding characteristics to the ferritic steel and the other to the YSZ electrolyte. Steel and electrolyte components were coated with alayer of their corresponding glass sealant paste and heated up to form a sandwich sample. During the heat treatment of the sealingprocess, the glasses are crystallized into glass-ceramics. The resulting interface between the two glass-ceramics is of special interest.Cross-sections of the sandwich samples were cut, polished and investigated using SEM. The glass-ceramics show continuous,gap-free layers and excellent bonding to both steel and YSZ. Energy release rates are measured for single and bilayered glass sealantsby mechanical testing. The designed bilayered glass-ceramics fulfill the special requirements of ferritic steel and YSZ. They showexcellent potential to become a new outstanding sealant for SOFCs

    A Composite Gene Expression Signature Optimizes Prediction of Colorectal Cancer Metastasis and Outcome.

    No full text
    PURPOSE: We previously found that an epithelial-to-mesenchymal transition (EMT)-based gene expression signature was highly correlated with the first principal component (PC1) of 326 colorectal cancer tumors and was prognostic. This study was designed to improve these signatures for better prediction of metastasis and outcome. EXPERIMENTAL DESIGN: A total of 468 colorectal cancer tumors including all stages (I-IV) and metastatic lesions were used to develop a new prognostic score (ΔPC1.EMT) by subtracting the EMT signature score from its correlated PC1 signature score. The score was validated on six other independent datasets with a total of 3,697 tumors. RESULTS: ΔPC1.EMT was found to be far more predictive of metastasis and outcome than its parent scores. It performed well in stages I to III, among microsatellite instability subtypes, and across multiple mutation-based subclasses, demonstrating a refined capacity to predict distant metastatic potential even in tumors with a "good" prognosis. For example, in the PETACC-3 clinical trial dataset, it predicted worse overall survival in an adjusted multivariable model for stage III patients (HR standardized by interquartile range [IQR] = 1.50; 95% confidence interval, 1.25-1.81; P = 0.000016, N = 644). The improved performance of ΔPC1.EMT was related to its propensity to identify epithelial-like subpopulations as well as mesenchymal-like subpopulations. Biologically, the signature was correlated positively with RAS signaling but negatively with mitochondrial metabolism. ΔPC1.EMT was a "best of assessed" prognostic score when compared with 10 other known prognostic signatures. CONCLUSIONS: The study developed a prognostic signature score with a propensity to detect non-EMT features, including epithelial cancer stem cell-related properties, thereby improving its potential to predict metastasis and poorer outcome in stage I-III patients

    Generic foundry model for InP-based photonics

    Get PDF
    Similarities and differences between photonic and microelectronic integration technology are discussed and a vision of the development of InP-based photonic integration in the coming decade is given

    Phase II clinical trial of pasireotide long-acting repeatable in patients with metastatic neuroendocrine tumors

    No full text
    Pasireotide long-acting repeatable (LAR) is a novel somatostatin analog (SSA) with avid binding affinity to somatostatin receptor subtypes 1, 2, 3 (SSTR1, 2, 3) and 5 (SSTR5). Results from preclinical studies indicate that pasireotide can inhibit neuroendocrine tumor (NET) growth more robustly than octreotide in vitro. This open-label, phase II study assessed the clinical activity of pasireotide in treatment-naïve patients with metastatic grade 1 or 2 NETs. Patients with metastatic pancreatic and extra-pancreatic NETs were treated with pasireotideLAR (60 mg every 4 weeks). Previous systemic therapy, including octreotide and lanreotide, was not permitted. Tumor assessments were performed every 3 months using Response Evaluation Criteria in Solid Tumors (RECIST) criteria. The primary endpoint was progression-free survival (PFS). The secondary end points in cluded over all survival (OS), over all radiographic responserate (ORR), and safety. Twenty-nine patients were treated with pasireotide LAR (60 mg every 4 weeks) and 28 were evaluable for response. The median PFS was 11 months. The most favorable effect was observed in patients with low hepatic tumor burden, normal baseline chromogranin A, and high tumoral SSTR5 expression. Median OS has not been reached; the 30-monthOSrate was 70%. The best radiographic response was partial response inone patient (4%), stable disease in 17 patients (60%), and progressive disease in ten patients (36%). Although grade 3/4 toxicities were rare, pasireotide LAR treatment was associated with a 79% rate of hyperglycemia including 14% grade 3 hyperglycemia. Although pasireotide appears to be an effective antiproliferative agent in the treatment of advanced NETs, the high incidence of hyperglycemia raises concerns regarding its suitability as a first-line systemic agent in unselected patients. SSTR5 expression is a potentially predictive biomarker for response
    corecore