NESC Review of the 8-Foot High Temperature Tunnel (HTT) Oxygen Storage Pressure Vessel Inspection Requirements

The 8-Foot HTT (refer to Figure 4.0-1) is used to conduct tests of air-breathing hypersonic propulsion systems at Mach numbers 4, 5, and 7. Methane, Air, and LOX are mixed and burned in a combustor to produce test gas stream containing 21 percent by volume oxygen. The NESC was requested by the NASA LaRC Executive Safety Council to review the rationale for a proposed change to the recertification requirements, specifically the internal inspection requirements, of the 8-Foot HTT LOX Run Tank and LOX Storage Tank. The Run Tank is an 8,000 gallon cryogenic tank used to provide LOX to the tunnel during operations, and is pressured during the tunnel run to 2,250 pounds per square inch gage (psig). The Storage Tank is a 25,000 gallon cryogenic tank used to store LOX at slightly above atmospheric pressure as a external shell, with space between the shells maintained under vacuum conditions

Determination of sub-ppb epichlorohydrin levels in water by on-line solid-phase extraction liquid chromatography/tandem mass spectrometry

A new sensitive and selective method based on on-line solid-phase extraction (SPE) coupled to liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) using a triple quadrupole mass spectrometer has been developed for the determination of epichlorohydrin (ECH) in different types of water samples. ECH is not easily determined directly by ESI-MS as it is not readily ionized, and it has a low molecular mass and high polarity. Thus, prior derivatization of ECH was necessary, employing 3,5-difluorobenzylamine as a derivatizing agent with Fe(III) as a catalyst. In order to achieve accurate quantification, correcting for matrix effects, losses in the derivatization process and instrumental deviations, isotope labelled ECH (ECH-d(5)) was added as an internal standard (IS) to the water samples. The method was validated based on European SANCO guidelines using drinking and other types of treated water spiked at two concentration levels (0.1 and 1.0 microg/L), the lower level having been established as the limit of quantification (LOQ) of the method. Satisfactory accuracy (recoveries between 70 and 103%), precision (RSD 0.99) were obtained. The limit of detection (LOD) was set up at 0.03 microg/L. The method was applied to different water samples (drinking water and water samples collected from a municipal treatment water plant). In order to enhance confidence, five selected reaction monitoring (SRM) transitions were acquired, thus obtaining a simultaneous reliable quantification and identification of ECH in water, even at sub-ppb level

Characterizing genomic alterations in cancer by complementary functional associations.

Systematic efforts to sequence the cancer genome have identified large numbers of mutations and copy number alterations in human cancers. However, elucidating the functional consequences of these variants, and their interactions to drive or maintain oncogenic states, remains a challenge in cancer research. We developed REVEALER, a computational method that identifies combinations of mutually exclusive genomic alterations correlated with functional phenotypes, such as the activation or gene dependency of oncogenic pathways or sensitivity to a drug treatment. We used REVEALER to uncover complementary genomic alterations associated with the transcriptional activation of β-catenin and NRF2, MEK-inhibitor sensitivity, and KRAS dependency. REVEALER successfully identified both known and new associations, demonstrating the power of combining functional profiles with extensive characterization of genomic alterations in cancer genomes

Colon cancer-derived oncogenic EGFR G724S mutant identified by whole genome sequence analysis is dependent on asymmetric dimerization and sensitive to cetuximab

Background: Inhibition of the activated epidermal growth factor receptor (EGFR) with either enzymatic kinase inhibitors or anti-EGFR antibodies such as cetuximab, is an effective modality of treatment for multiple human cancers. Enzymatic EGFR inhibitors are effective for lung adenocarcinomas with somatic kinase domain EGFR mutations while, paradoxically, anti-EGFR antibodies are more effective in colon and head and neck cancers where EGFR mutations occur less frequently. In colorectal cancer, anti-EGFR antibodies are routinely used as second-line therapy of KRAS wild-type tumors. However, detailed mechanisms and genomic predictors for pharmacological response to these antibodies in colon cancer remain unclear. Findings: We describe a case of colorectal adenocarcinoma, which was found to harbor a kinase domain mutation, G724S, in EGFR through whole genome sequencing. We show that G724S mutant EGFR is oncogenic and that it differs from classic lung cancer derived EGFR mutants in that it is cetuximab responsive in vitro, yet relatively insensitive to small molecule kinase inhibitors. Through biochemical and cellular pharmacologic studies, we have determined that cells harboring the colon cancer-derived G719S and G724S mutants are responsive to cetuximab therapy in vitro and found that the requirement for asymmetric dimerization of these mutant EGFR to promote cellular transformation may explain their greater inhibition by cetuximab than small-molecule kinase inhibitors. Conclusion: The colon-cancer derived G719S and G724S mutants are oncogenic and sensitive in vitro to cetuximab. These data suggest that patients with these mutations may benefit from the use of anti-EGFR antibodies as part of the first-line therapy

Epidermal Growth Factor Receptor Activation in Glioblastoma through Novel Missense Mutations in the Extracellular Domain

Background: Protein tyrosine kinases are important regulators of cellular homeostasis with tightly controlled catalytic activity. Mutations in kinase-encoding genes can relieve the autoinhibitory constraints on kinase activity, can promote malignant transformation, and appear to be a major determinant of response to kinase inhibitor therapy. Missense mutations in the EGFR kinase domain, for example, have recently been identified in patients who showed clinical responses to EGFR kinase inhibitor therapy. Methods and Findings: Encouraged by the promising clinical activity of epidermal growth factor receptor (EGFR) kinase inhibitors in treating glioblastoma in humans, we have sequenced the complete EGFR coding sequence in glioma tumor samples and cell lines. We identified novel missense mutations in the extracellular domain of EGFR in 13.6% (18/132) of glioblastomas and 12.5% (1/ 8) of glioblastoma cell lines. These EGFR mutations were associated with increased EGFR gene dosage and conferred anchorage-independent growth and tumorigenicity to NIH-3T3 cells. Cells transformed by expression of these EGFR mutants were sensitive to small-molecule EGFR kinase inhibitors. Conclusions: Our results suggest extracellular missense mutations as a novel mechanism for oncogenic EGFR activation and may help identify patients who can benefit from EGFR kinase inhibitors for treatment of glioblastoma

Medulloblastoma Exome Sequencing Uncovers Subtype-Specific Somatic Mutations

Medulloblastomas are the most common malignant brain tumors in children1. Identifying and understanding the genetic events that drive these tumors is critical for the development of more effective diagnostic, prognostic and therapeutic strategies. Recently, our group and others described distinct molecular subtypes of medulloblastoma based on transcriptional and copy number profiles2–5. Here, we utilized whole exome hybrid capture and deep sequencing to identify somatic mutations across the coding regions of 92 primary medulloblastoma/normal pairs. Overall, medulloblastomas exhibit low mutation rates consistent with other pediatric tumors, with a median of 0.35 non-silent mutations per megabase. We identified twelve genes mutated at statistically significant frequencies, including previously known mutated genes in medulloblastoma such as CTNNB1, PTCH1, MLL2, SMARCA4 and TP53. Recurrent somatic mutations were identified in an RNA helicase gene, DDX3X, often concurrent with CTNNB1 mutations, and in the nuclear co-repressor (N-CoR) complex genes GPS2, BCOR, and LDB1, novel findings in medulloblastoma. We show that mutant DDX3X potentiates transactivation of a TCF promoter and enhances cell viability in combination with mutant but not wild type beta-catenin. Together, our study reveals the alteration of Wnt, Hedgehog, histone methyltransferase and now N-CoR pathways across medulloblastomas and within specific subtypes of this disease, and nominates the RNA helicase DDX3X as a component of pathogenic beta-catenin signaling in medulloblastoma

Charakterisierung eines Displays als Kommunikationsschnittstelle eines autonomen Fahrzeugs

Situationen im innerstädtischen Straßenverkehr, in denen die Vorfahrt nicht eindeutig geregelt ist, werden im Allgemeinen als Pattsituation bezeichnet. Zur Lösung dieser Situationen durch Verzicht sind die Beteiligten, auch nach der StVO, angehalten, zu kommunizieren und sich untereinander zu verständigen. Hierfür erlernte Kommunikationsmethoden, wie Blickkontakt oder Gesten, entfallen bei einem autonomen Fahrzeug, in dem die Fahrzeuginsassen ausschließlich Passagiere sind. Eine lichtbasierte Mensch-Maschine-Schnittstelle soll diese sich auftuende Lücke schließen. Ein möglicher Ansatz hierfür ist ein LED-Display, das an der Fahrzeugfront montiert wird. Zur Kommunikation werden verschiedene Inhalte, wie Formen, Text oder Symbole angezeigt. Daraus ergeben sich einige Herausforderungen, wie beispielsweise die Sichtbarkeit der angezeigten Inhalte in verschiedenen Situationen, unabhängig der Umgebungshelligkeit. Aus diesem Grund wird die Sichtbarkeit der Darstellung auf dem Display unter dem Einfluss verschiedener Störgrößen wie Fremdlicht oder Winkelabhängigkeit überprüft und das Display dahingehend im realen Umfeld charakterisiert. Weiter wird abgeschätzt, ob eine Eignung des Displays als Kommunikationsschnittstelle generell möglich ist. Erkenntnisse für den Betrieb im realen Umfeld wurden daraus abgeleitet und Anforderungen formuliert