Lateral conduction effects on heat-transfer data obtained with the phase-change paint technique

A computerized tool, CAPE, (Conduction Analysis Program using Eigenvalues) has been developed to account for lateral heat conduction in wind tunnel models in the data reduction of the phase-change paint technique. The tool also accounts for the effects of finite thickness (thin wings) and surface curvature. A special reduction procedure using just one time of melt is also possible on leading edges. A novel iterative numerical scheme was used, with discretized spatial coordinates but analytic integration in time, to solve the inverse conduction problem involved in the data reduction. A yes-no chart is provided which tells the test engineer when various corrections are large enough so that CAPE should be used. The accuracy of the phase-change paint technique in the presence of finite thickness and lateral conduction is also investigated

High Performance Ultra-light Nuclear Rockets for NEO (Near Earth Objects) Interaction Missions

The performance capabilities and technology features of ultra compact nuclear thermal rockets based on very high power density ({approximately} 30 Megawatts per liter) fuel elements are described. Nuclear rockets appear particularly attractive for carrying out missions to investigate or intercept Near Earth Objects (NEOS) that potentially could impact on the Earth. Many of these NEO threats, whether asteroids or comets, have extremely high closing velocities, i.e., tens of kilometers per second relative to the Earth. Nuclear rockets using hydrogen propellant enable flight velocities 2 to 3 times those achievable with chemical rockets, allowing interaction with a potential NEO threat at a much shorter time, and at much greater range. Two versions of an ultra compact nuclear rocket based on very high heat transfer rates are described: the PBR (Particle Bed Reactor), which has undergone substantial hardware development effort, and MITEE (Miniature Reactor Engine) which is a design derivative of the PBR. Nominal performance capabilities for the PBR are: thermal power - 1000 MW thrust - 45,000 lbsf, and weight - 500 kg. For MITEE, nominal capabilities are: thermal power - 100 MW; thrust {approx} 4500 lbsf, and weight - 50 kg. Development of operational PBR/MITEE systems would enable spacecraft launched from LEO (Low Earth Orbit) to investigate intercept NEO`s at a range of {approximately} 100 million kilometers in times of {approximately} 30 days

Private sector involvement in the US program of technical assistance to IAEA safeguards

The US Program of Technical Assistance to IAEA Safeguards (POTAS) relies on technical expertise found in the U. S private and public sectors. Since 1993, the international Safeguards Project Office (ISPO) has sought to increase the role of the private sector in POTAS. ISPO maintains and continues to develop a database of US companies interested in providing technical expertise to the IAEA. This database is used by ISPO to find appropriate contractors to respond to IAEA requests for technical assistance when the assistance can be provided by the private sector. The private sector is currently providing support in the development of equipment, training, and procedure preparation. POTAS also supports the work of private consultants. This paper discusses ISPO`s efforts to identify suitable vendors and discusses conditions that hinder more substantial involvement by the private sector. In addition, the paper will discuss selected projects that are currently in progress and identify common problems that impede the progress and success of tasks performed by the private sector

Prevalence of pre-cancerous lesions and cervical cancer in South Africa - A multicentre study

Objectives. To describe the age-specific prevalence rates of cancer of the cervix in South African women presenting for screening.Design. A multicentre prevalence survey in 10 geographically defined areas following a common core protocol. Services were located in existing service sites, with the exception of KwaZulu-Natal which used a mobile service. Women aged 20 years and above were eligible for inclusion.Outcome measures. Age-specific cervical cytologically diagnosed abnormality rates according to the Bethesda classification.Results. During the study 20 603 women participated. Eighty per cent of the sample had never had a Pap smear before and just over 91 % had not had a Pap smear in the last 5 years. Inthis study population 468 women screened (2.42%) were found to have low-grade squamous intra-epithelial lesions (LSIL) and the average age of these women was 33.1 years; 366 (1.8%) had high-grade SIL (HSIL) and these women were statistically significantly older at 37.97 years of age; and 92 women (0.47%) were found to have cytologically diagnosed invasive cancer. These women were significantly older, with an average age of 51.3 years. A clear relationship was found between age and LSIL, with younger women having a high rate of LSIL which decreases with increasing age. A similar but inverse relationship between age and invasive cancer is described, with the rate being low in young women and increasing with increasing age. A clear relationship between HSIL and age is not described in these data. The adequacy rate (satisfactory and satisfactory but limited) of the slides was 95%, and just under 92% of the study sample received their results. Not all women were appropriately referred and it was not possible to assess if women referred for treatment received it.Conclusions. These data indicate that cancer of the cervix is a common disease and that, similar to other countries, it is a disease of older women. These data give some positive indicators for future screening - older women will present for screening and the majority of women received their results. However, improvements in health system functioning are needed. A uniform national cytology reporting system is required as well as clear guidelines for providers on what action to take based on cytology reports. Linkage between the site of screening and treatment centre is inadequate and requires urgent attention in order to decrease cervical cancer mortality

Pulmonary venous circulating tumor cell dissemination before tumor resection and disease relapse

Approximately 50% of patients with early-stage non-small-cell lung cancer (NSCLC) who undergo surgery with curative intent will relapse within 5 years1,2. Detection of circulating tumor cells (CTCs) at the time of surgery may represent a tool to identify patients at higher risk of recurrence for whom more frequent monitoring is advised. Here we asked whether CellSearch-detected pulmonary venous CTCs (PV-CTCs) at surgical resection of early-stage NSCLC represent subclones responsible for subsequent disease relapse. PV-CTCs were detected in 48% of 100 patients enrolled into the TRACERx study3, were associated with lung-cancer-specific relapse and remained an independent predictor of relapse in multivariate analysis adjusted for tumor stage. In a case study, genomic profiling of single PV-CTCs collected at surgery revealed higher mutation overlap with metastasis detected 10 months later (91%) than with the primary tumor (79%), suggesting that early-disseminating PV-CTCs were responsible for disease relapse. Together, PV-CTC enumeration and genomic profiling highlight the potential of PV-CTCs as early predictors of NSCLC recurrence after surgery. However, the limited sensitivity of PV-CTCs in predicting relapse suggests that further studies using a larger, independent cohort are warranted to confirm and better define the potential clinical utility of PV-CTCs in early-stage NSCLC

Interaction between a normal shock wave and a turbulent boundary layer at high transonic speeds. Part I: Pressure distribution

Asymptotic solutions are derived for the pressure distribution in the interaction of a weak normal shock wave with a turbulent boundary layer. The undisturbed boundary layer is characterized by the law of the wall and the law of the wake for compressible flow. In the limiting case considered, for ‘high’ transonic speeds, the sonic line is very close to the wall. Comparisons with experiment are shown, with corrections included for the effect of longitudinal wall curvature and for the boundary-layer displacement effect in a circular pipe. Asymptotische Lösungen für den Druckverlauf bei der Wechselwirkung zwischen einem schwachen normalen Stoss und einer turbulente Grenzschicht werden hergeleitet. Das Wandgesetz und Geschwindigkeitsdefekt-Gesetz für kompressible Strömung kennzeichnen die ungestörte Grenzschicht. Der Grenzfall hoher transsonischen Strömung, in dem die Schallinie in der Nähe der Wand liegt, wird untersucht. Die theoretischen Ergebnisse werden mit Experimenten verglichen. Dabei wird die Wandkrümmung und im Fall der Rohrströmung die Verdrängungsdicke berücksichtigt.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43384/1/33_2005_Article_BF01590748.pd

The evolution of non-small cell lung cancer metastases in TRACERx

Metastatic disease is responsible for the majority of cancer-related deaths1. We report the longitudinal evolutionary analysis of 126 non-small cell lung cancer (NSCLC) tumours from 421 prospectively recruited patients in TRACERx who developed metastatic disease, compared with a control cohort of 144 non-metastatic tumours. In 25% of cases, metastases diverged early, before the last clonal sweep in the primary tumour, and early divergence was enriched for patients who were smokers at the time of initial diagnosis. Simulations suggested that early metastatic divergence more frequently occurred at smaller tumour diameters (less than 8 mm). Single-region primary tumour sampling resulted in 83% of late divergence cases being misclassified as early, highlighting the importance of extensive primary tumour sampling. Polyclonal dissemination, which was associated with extrathoracic disease recurrence, was found in 32% of cases. Primary lymph node disease contributed to metastatic relapse in less than 20% of cases, representing a hallmark of metastatic potential rather than a route to subsequent recurrences/disease progression. Metastasis-seeding subclones exhibited subclonal expansions within primary tumours, probably reflecting positive selection. Our findings highlight the importance of selection in metastatic clone evolution within untreated primary tumours, the distinction between monoclonal versus polyclonal seeding in dictating site of recurrence, the limitations of current radiological screening approaches for early diverging tumours and the need to develop strategies to target metastasis-seeding subclones before relaps

The role of APOBEC3B in lung tumor evolution and targeted cancer therapy resistance

In this study, the impact of the apolipoprotein B mRNA-editing catalytic subunit-like (APOBEC) enzyme APOBEC3B (A3B) on epidermal growth factor receptor (EGFR)-driven lung cancer was assessed. A3B expression in EGFR mutant (EGFRmut) non-small-cell lung cancer (NSCLC) mouse models constrained tumorigenesis, while A3B expression in tumors treated with EGFR-targeted cancer therapy was associated with treatment resistance. Analyses of human NSCLC models treated with EGFR-targeted therapy showed upregulation of A3B and revealed therapy-induced activation of nuclear factor kappa B (NF-κB) as an inducer of A3B expression. Significantly reduced viability was observed with A3B deficiency, and A3B was required for the enrichment of APOBEC mutation signatures, in targeted therapy-treated human NSCLC preclinical models. Upregulation of A3B was confirmed in patients with NSCLC treated with EGFR-targeted therapy. This study uncovers the multifaceted roles of A3B in NSCLC and identifies A3B as a potential target for more durable responses to targeted cancer therapy.</p

The role of APOBEC3B in lung tumor evolution and targeted cancer therapy resistance

In this study, the impact of the apolipoprotein B mRNA-editing catalytic subunit-like (APOBEC) enzyme APOBEC3B (A3B) on epidermal growth factor receptor (EGFR)-driven lung cancer was assessed. A3B expression in EGFR mutant (EGFRmut) non-small-cell lung cancer (NSCLC) mouse models constrained tumorigenesis, while A3B expression in tumors treated with EGFR-targeted cancer therapy was associated with treatment resistance. Analyses of human NSCLC models treated with EGFR-targeted therapy showed upregulation of A3B and revealed therapy-induced activation of nuclear factor kappa B (NF-κB) as an inducer of A3B expression. Significantly reduced viability was observed with A3B deficiency, and A3B was required for the enrichment of APOBEC mutation signatures, in targeted therapy-treated human NSCLC preclinical models. Upregulation of A3B was confirmed in patients with NSCLC treated with EGFR-targeted therapy. This study uncovers the multifaceted roles of A3B in NSCLC and identifies A3B as a potential target for more durable responses to targeted cancer therapy