1,264 research outputs found

    Ames facility for simulating planetary probe heating environments

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    Progress is reported on the development of a giant-planet pilot facility which simulates the conditions expected at the peak heating point for a shallow entry into the atmosphere of Saturn, Jupiter, and Uranus

    Electric arc apparatus Patent

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    Electric arc heater with supersonic nozzle and fixed arc length for use in high temperature wind tunnel

    Ethnic disparities in quality of diabetes care in Scotland:a national cohort study

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    Aims: The aim of this study is to compare quality of diabetes care in people with type 2 diabetes by ethnicity, in Scotland. Methods: Using a linked national diabetes registry, we included 162,122 people newly diagnosed with type 2 diabetes between 2009 and 2018. We compared receipt of nine guideline indicated processes of care in the first-year post-diabetes diagnosis using logistic regression, comparing eight ethnicity groups to the White group. We compared annual receipt of HbA1c and eye screening during the entire follow-up using generalised linear mixed effects. All analyses adjusted for confounders. Results: Receipt of diabetes care was lower in other ethnic groups compared to White people in the first-year post-diagnosis. Differences were most pronounced for people in the: African, Caribbean or Black; Indian; and other ethnicity groups for almost all processes of care. For example, compared to White people, odds of HbA1c monitoring were: 44% lower in African, Caribbean or Black people (OR 0.56 [95% CI 0.48, 0.66]); 47% lower in Indian people (OR 0.53 [95% CI 0.47, 0.61]); and 50% lower in people in the other ethnicity group (OR 0.50 [95% CI 0.46, 0.58]). Odds of receipt of eye screening were 30%–40% lower in most ethnic groups compared to the White group. During median 5 year follow-up, differences in HbA1c monitoring and eye screening largely persisted, but attenuated slightly for the former. Conclusions: There are marked ethnic disparities in routine diabetes care in Scotland in the short- and medium-term following diabetes diagnosis. Further investigation is needed to establish and effectively address the underlying reasons.</p

    M-CGH: Analysing microarray-based CGH experiments

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    BACKGROUND: Microarray-based comparative genomic hybridisation (array CGH) is a technique by which variation in relative copy numbers between two genomes can be analysed by competitive hybridisation to DNA microarrays. This technology has most commonly been used to detect chromosomal amplifications and deletions in cancer. Dedicated tools are needed to analyse the results of such experiments, which include appropriate visualisation, and to take into consideration the physical relation in the genome between the probes on the array. RESULTS: M-CGH is a MATLAB toolbox with a graphical user interface designed specifically for the analysis of array CGH experiments, with multiple approaches to ratio normalization. Specifically, the distributions of three classes of DNA copy numbers (gains, normal and losses) can be estimated using a maximum likelihood method. Amplicon boundaries are computed by either the fuzzy K-nearest neighbour method or a wavelet approach. The program also allows linking each genomic clone with the corresponding genomic information in the Ensembl database . CONCLUSIONS: M-CGH, which encompasses the basic tools needed for analysing array CGH experiments, is freely available for academics , and does not require any other MATLAB toolbox

    Cervical Cancer in Women Aged 35 Years and Younger

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    AbstractPurposeAge has been evaluated as a prognostic factor in cervical cancer in both hospital- and population-based studies. Results regarding the relation of age and cervical cancer prognosis are conflicting. This study pursued a contemporary assessment of the association of extreme young age at the time of a cervical cancer diagnosis on survival.MethodsInstitutional review board approval was obtained, and retrospective data collection at 2 academic institutions was performed. Inclusion criteria involved women ≤35 years diagnosed with cervical cancer between 1990 and 2012. Data included demographic and prognostic information pertinent to survival and progression. Characteristics of very young (≤25 years) and young (>25–35 years) women were compared. Kaplan-Meier estimates, the log-rank test, and Cox proportional hazards modeling were used to assess the association of age, tumor histology, grade, stage, and parametrial involvement with progression-free survival (PFS) and overall survival (OS).FindingsIncident cases (n = 126) of cervical cancer in patients ≤35 years of age were identified of which complete clinical information was available for 114 women. Fifteen percent (17 of 114) were ≤25 years, with the remaining 85% (97 of 114) being 26 to 35 years of age. Race, smoking status, and marital status were comparable between the 2 groups. Squamous histology dominated overall (77 of 114; 68%) with adenocarcinoma contributing ~25% (30 of 114; 26%) of cases. The majority (96 of 114, 84%) had either stage 1A (31 of 114, 27%) or 1B (65 of 114, 57%) disease. A log-rank test revealed no evidence to infer a difference in either PFS or OS among the age groups (P = 0.511 and P = 0.340). In a univariate analysis, grade and stage significantly affected OS (P < 0.0001, P = 0.045), and stage significantly affected PFS (P < 0.0001). In multivariate modeling, presence of parametrial involvement and histologic cancer type significantly affected both PFS (P = 0.002, P = 0.001) and OS (P = 0.001, P = 0.001).ImplicationsTumor histology, parametrial involvement, and stage continue to be strong prognosticators for PFS and OS. Progression and survival outcomes are age independent in women with cervical cancer ≤35 years of age. Further study of a larger young cohort may potentially yield different outcomes

    Evaluation of high-resolution microarray platforms for genomic profiling of bone tumours

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    <p>Abstract</p> <p>Background</p> <p>Several high-density oligonucleotide microarray platforms are available for genome-wide single nucleotide polymorphism (SNP) detection and microarray-based comparative genomic hybridisation (array CGH), which may be used to detect copy number aberrations in human tumours. As part of the EuroBoNeT network of excellence for research on bone tumours (eurobonet.eu), we have evaluated four different commercial high-resolution microarray platforms in order to identify the most appropriate technology for mapping DNA copy number aberrations in such tumours.</p> <p>Findings</p> <p>DNA from two different cytogenetically well-characterized bone sarcoma cell lines, representing a simple and a complex karyotype, respectively, was tested in duplicate on four high-resolution microarray platforms; Affymetrix Genome-Wide Human SNP Array 6.0, Agilent Human Genome CGH 244A, Illumina HumanExon510s-duo and Nimblegen HG18 CGH 385 k WG tiling v1.0. The data was analysed using the platform-specific analysis software, as well as a platform-independent analysis algorithm. DNA copy number was measured at six specific chromosomes or chromosomal regions, and compared with the expected ratio based on available cytogenetic information. All platforms performed well in terms of reproducibility and were able to delimit and score small amplifications and deletions at similar resolution, but Agilent microarrays showed better linearity and dynamic range. The platform-specific analysis software provided with each platform identified in general correct copy numbers, whereas using a platform-independent analysis algorithm, correct copy numbers were determined mainly for Agilent and Affymetrix microarrays.</p> <p>Conclusions</p> <p>All platforms performed reasonably well, but Agilent microarrays showed better dynamic range, and like Affymetrix microarrays performed well with the platform-independent analysis software, implying more robust data. Bone tumours like osteosarcomas are heterogeneous tumours with complex karyotypes that may be difficult to interpret, and it is of importance to be able to well separate the copy number levels and detect copy number changes in subpopulations. Taking all this into consideration, the Agilent and Affymetrix microarray platforms were found to be a better choice for mapping DNA copy numbers in bone tumours, the latter having the advantage of also providing heterozygosity information.</p

    DNA copy number changes in high-grade malignant peripheral nerve sheath tumors by array CGH

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    <p>Abstract</p> <p>Background</p> <p>Malignant peripheral nerve sheath tumors (MPNSTs) are rare and highly aggressive soft tissue tumors showing complex chromosomal aberrations. In order to identify recurrent chromosomal regions of gain and loss, and thereby novel gene targets of potential importance for MPNST development and/or progression, we have analyzed DNA copy number changes in seven high-grade MPNSTs using microarray-based comparative genomic hybridization (array CGH).</p> <p>Results</p> <p>Considerable more gains than losses were observed, and the most frequent minimal recurrent regions of gain included 1q24.1-q24.2, 1q24.3-q25.1, 8p23.1-p12, 9q34.11-q34.13 and 17q23.2-q25.3, all gained in five of seven samples. The 17q23.2-q25.3 region was gained in all five patients with poor outcome and not in the two patients with disease-free survival. cDNA microarray analysis and quantitative real-time reverse transcription PCR were used to investigate expression of genes located within these regions. The gene lysyl oxidase-like 2 (<it>LOXL2</it>) was identified as a candidate target for the 8p23.1-p12 gain. Within 17q, the genes topoisomerase II-α (<it>TOP2A</it>), ets variant gene 4 (E1A enhancer binding protein, <it>E1AF</it>) (<it>ETV4</it>) and baculoviral IAP repeat-containing 5 (survivin) (<it>BIRC5</it>) showed increased expression in all samples compared to two benign tumors. Increased expression of these genes has previously been associated with poor survival in other malignancies, and for <it>TOP2A</it>, in MPNSTs as well. In addition, we have analyzed the expression of five micro RNAs located within the 17q23.2-q25.3 region, but none of them showed high expression levels compared to the benign tumors.</p> <p>Conclusion</p> <p>Our study shows the potential of using DNA copy number changes obtained by array CGH to predict the prognosis of MPNST patients. Although no clear correlations between the expression level and patient outcome were observed, the genes <it>TOP2A</it>, <it>ETV4 </it>and <it>BIRC5 </it>are interesting candidate targets for the 17q gain associated with poor survival.</p

    Temporal expression pattern of genes during the period of sex differentiation in human embryonic gonads

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    Abstract The precise timing and sequence of changes in expression of key genes and proteins during human sex-differentiation and onset of steroidogenesis was evaluated by whole-genome expression in 67 first trimester human embryonic and fetal ovaries and testis and confirmed by qPCR and immunohistochemistry (IHC). SRY/SOX9 expression initiated in testis around day 40 pc, followed by initiation of AMH and steroidogenic genes required for androgen production at day 53 pc. In ovaries, gene expression of RSPO1, LIN28, FOXL2, WNT2B, and ETV5, were significantly higher than in testis, whereas GLI1 was significantly higher in testis than ovaries. Gene expression was confirmed by IHC for GAGE, SOX9, AMH, CYP17A1, LIN28, WNT2B, ETV5 and GLI1. Gene expression was not associated with the maternal smoking habits. Collectively, a precise temporal determination of changes in expression of key genes involved in human sex-differentiation is defined, with identification of new genes of potential importance
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