5,341 research outputs found
Influence of temperature and sliding speed on the subsurface microstructure evolution of EN AW-6060 under sticking friction conditions
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in AIP Conference Proceedings 1896, 140012 (2017) and may be found at https://doi.org/10.1063/1.5008168.The microstructure evolution of the friction boundary layer of the aluminum alloy EN AW-6060 was investigated. Sticking friction tests at different temperatures and sliding speeds were carried out. A severe deformation below the friction surface was observed by means of LOM and EBSD mapping. Thus, the thickness variation and the grain structure of the high deformation zone could be described. Fibrous structure was observed at 300 °C and 400 °C, while equiaxed grains with high misorientation angle (>15°) were generated at higher temperatures. Additionally, abnormal grain growth and coarse grains were detected at high sliding speeds (10 mm/s, 42 mm/s) at 450°C and 500 °C respectively
First results of cross-correlation analysis of ambient seismic noise from the Hellenic Unified Seismic Network
No full textIn this study we present phase velocity maps that were obtained from the cross-correlation analysis of ambient seismic noise recorded in the region of Greece.We used one year (2013) of ambient seismic data obtained from the vertical component of 64 broadband permanent seismological stations that are part of the Hellenic Unified Seismic Network. Inter-station istances between these stations ranged from 60 to 840 km and the number of station pairs was 2054. All signals were corrected for instrument response, the trend was removed and the mean was subtracted. The data of each station was split in 4 hr time windows. Each window was systematically searched to remove earthquake signals and instrument problems and then the remaining 4 hr windows were spectrally whitened. For the last stage of the processing, the 4 hr data of each station pair were independently cross-correlated and then were stacked over the whole year into one time-series. This cross-correlation function contains the causal and acausal part of the Green’s function of the medium between these two stations. Because ambient noise sources are not uniformly distributed, these two parts of the Green’s function (causal and acausal) are not identical. In our analysis we used the part of Green’s function that has the strongest and cleanest amplitude. Then, the individual phase velocity dispersion curves are obtained for all the cross-correlation functions by using frequency time analysis. Finally, the phase velocity curves are used to create phase velocity maps in the period band of 8 to 30 sec. These maps in a later stage will be inverted for shear-velocity structure
Limited antigenic diversity of Plasmodium falciparumapical membrane antigen 1 supports the development of effective multi-allele vaccines
No full textBackground: Polymorphism in antigens is a common mechanism for immune evasion used by many important pathogens, and presents major challenges in vaccine development. In malaria, many key immune targets and vaccine candidates show substantial polymorphism. However, knowledge on antigenic diversity of key antigens, the impact of polymorphism on potential vaccine escape, and how sequence polymorphism relates to antigenic differences is very limited, yet crucial for vaccine development. Plasmodium falciparum apical membrane antigen 1 (AMA1) is an important target of naturally-acquired antibodies in malaria immunity and a leading vaccine candidate. However, AMA1 has extensive allelic diversity with more than 60 polymorphic amino acid residues and more than 200 haplotypes in a single population. Therefore, AMA1 serves as an excellent model to assess antigenic diversity in malaria vaccine antigens and the feasibility of multi-allele vaccine approaches. While most previous research has focused on sequence diversity and antibody responses in laboratory animals, little has been done on the cross-reactivity of human antibodies. Methods: We aimed to determine the extent of antigenic diversity of AMA1, defined by reactivity with human antibodies, and to aid the identification of specific alleles for potential inclusion in a multi-allele vaccine. We developed an approach using a multiple-antigen-competition enzyme-linked immunosorbent assay (ELISA) to examine cross-reactivity of naturally-acquired antibodies in Papua New Guinea and Kenya, and related this to differences in AMA1 sequence. Results: We found that adults had greater cross-reactivity of antibodies than children, although the patterns of cross-reactivity to alleles were the same. Patterns of antibody cross-reactivity were very similar between populations (Papua New Guinea and Kenya), and over time. Further, our results show that antigenic diversity of AMA1 alleles is surprisingly restricted, despite extensive sequence polymorphism. Our findings suggest that a combination of three different alleles, if selected appropriately, may be sufficient to cover the majority of antigenic diversity in polymorphic AMA1 antigens. Antigenic properties were not strongly related to existing haplotype groupings based on sequence analysis. Conclusions: Antigenic diversity of AMA1 is limited and a vaccine including a small number of alleles might be sufficient for coverage against naturally-circulating strains, supporting a multi-allele approach for developing polymorphic antigens as malaria vaccines
Abstract P2-03-09: An institutional look back: Maximizing the utility of MammaPrint® in invasive breast cancer diagnostics without breaking the bank
No full textAbstract
Background: Subtyping of invasive breast cancer utilizing immunohistochemical stains for estrogen receptor, progesterone receptor, and HER2, with or without the proliferation marker Ki-67, is the current standard of care employed by pathologists. The development of the BluePrint® molecular subtyping assay by Agendia, a microarray-based gene expression test used in conjunction with MammaPrint, to molecularly subtype and assess recurrence risk in early-stage breast cancer, has breast surgeons and oncologists challenging the status quo.
Study Objectives: With increasing emphasis placed of proper use of declining resources, the current study aimed to determine parameters in which such testing has the greatest added value.
Materials and Methods: All invasive breast cancer biopsies and resection specimens with formalin fixed paraffin embedded tissue sent for testing at Agendia Genomics Laboratory from April 2015 to May 2017 were reviewed in an institutional look back. 87 cases were reviewed and conventional immunohistochemical cancer profiling, tumor size, and grade were compared with MammaPrint prognostic reports.
Results and Discussion: Of the 87 cases compared, 67 (77%) showed concordance between immunohistochemical and molecular subtyping. Of the 20 discordant cases, 13 (65%) were subtyped as low risk luminal A by Mammaprint/BluePrint despite demonstrating high risk clinicopathologic features including larger size (average 2 cm vs overall average 1.4 cm), higher grade (1 low grade, 11 intermediate grade, and 1 high grade vs totals of 36 low grade, 42 intermediate grade, and 20 high grade), and increased proliferation indices. 3 (15%) of discordant cases revealed HER2 amplification by fluorescence in situ hybridization. Near complete agreement was found among basal subtype and Luminal A tumors with Ki-67 less than 12%, indicating the lack of added value among these cases.
Conclusion: Study results validate the limited role of MammaPrint/BluePrint in cases of invasive breast cancer. Specifically, the greatest value of MammaPrint/BluePrint was recognized in luminal subtypes with intermediate grade and proliferation indices ranging from 12 – 29%.
Citation Format: Cross AW, McEvoy JR. An institutional look back: Maximizing the utility of MammaPrint® in invasive breast cancer diagnostics without breaking the bank [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-03-09.</jats:p
Synthesis and Characterization of Biobased Polyesters with Tunable T-g by ROCOP of Beta-Elemene Oxides and Phthalic Anhydride
No full textThe use of terpene-based oxides derived from beta-elemene is reported in the context of new functional semiaromatic polyester development. In particular, poly(beta-elemene monoxide-alt-phthalic anhydride) featuring two double bonds per repeating unit having distinct reactivity is conveniently prepared by iron- and aluminum-mediated ring-opening polymerization (ROCOP). Sequential and selective transformation of each of these double bonds is addressed by epoxidation allowing one to precisely manipulate the degree and nature of the functionality in the polymer backbone while modulating the T-g from 68 to 121 degrees C. Direct access to cross-linked polyesters is demonstrated by ROCOP of bifunctional beta-elemene dioxide and phthalic anhydride furnishing a material with a Tg of 125 degrees C
Bovine pericardium based non-cross linked collagen matrix for successful root coverage, a clinical study in human
No full textIntroduction: The aim of this study was to clinically assess the capacity of a novel bovine pericardium based, non-cross linked collagen matrix in root coverage.
Methods: 62 gingival recessions of Miller class I or II were treated. The matrix was adapted underneath a coronal repositioned split thickness flap. Clinical values were assessed at baseline and after six months.
Results: The mean recession in each patient was 2.2 mm at baseline. 6 Months after surgery 86.7% of the exposed root surfaces were covered. On average 0,3 mm of recession remained. The clinical attachment level changed from 3.5 ± 1.3 mm to 1,8 ( ± 0,7) mm during the observational time period. No statistically significant difference was found in the difference of probing depth. An increase in the width of gingiva was significant. With a baseline value of 1.5 ± 0.9 mm an improvement of 2.4 ± 0.8 mm after six month could be observed. 40 out of 62 recessions were considered a thin biotype at baseline. After 6 months all 62 sites were assessed thick.
Conclusions: The results demonstrate the capacity of the bovine pericardium based non-cross linked collagen matrix for successful root coverage. This material was able to enhance gingival thickness and the width of keratinized gingiva. The percentage of root coverage achieved thereby is comparable to existing techniques. This method might contribute to an increase of patient's comfort and an enhanced aesthetical outcome
Lamb, Cross, ΑΩ
No full textLamb, cross, + AW. Milan - Museum. E.F. II.25.20ahttps://digitalcommons.acu.edu/ferguson_photos/1790/thumbnail.jp
Author-Suggested, Weighted Citation Index: A Novel Approach for Determining the Contribution of Individual Researchers
No full textA novel scientometric index, named ‘author-suggested, weighted citation index’ (Aw-index) is proposed to indicate the scientific contribution of any individual researcher. For calculation of the Aw-index, it is suggested that during the submission of a scholarly article, the corresponding author would provide a statement, agreed upon by all the authors, containing weightage factors against each author of the article. The author who contributed more to the article would secure a higher weightage factor. The summation of the weightage factors of all the authors of an article should be unity. The citation points a researcher receives from a scholarly publication is the product of his/her weightage factor for that article and the total number of citations of the article. The Aw-index of any individual researcher is the summation of the citation points he/she receives for all his/her publications as an author. The Aw-index provides the opportunity to the group of authors of a multi-authored article to determine the quantum of partial citations to be attributed to each of them. Through an illustrative example, a comparison of the proposed index with the major scientometric indexes is presented to highlight the advantages of the Aw-index
a cross-entropy based multiagent approach for multiclass activity chain modeling and simulation
No full textThis paper attempts to model complex destination-chain, departure time and route choices based on activity plan implementation and proposes an arc-based cross entropy method for solving approximately the dynamic user equilibrium in multiagent-based multiclass network context. A multiagent-based dynamic activity chain model is developed, combining travelers' day-to-day learning process in the presence of both traffic flow and activity supply dynamics. The learning process towards user equilibrium in multiagent systems is based on the framework of Bellman's principle of optimality, and iteratively solved by the cross entropy method. A numerical example is implemented to illustrate the performance of the proposed method on a multiclass queuing network.dynamic traffic assignment, cross entropy method, activity chain, multiagent, Bellman equation
Earing Prediction of Unidirectionally and Cross-rolled, Annealed AW-5056 Al Sheets from {h00} Pole Figures
No full textEaring of deep drawn cups is an effective measure of plastic anisotropy. It is the result of crystallographic
anisotropy, i.e. texture. There are several methods to predict earing, but all of these methods are rather complex.
Furthermore, above a certain sheet thickness, deep drawing cannot be performed, and prediction methods
fail since they are usually valid within a certain sheet thickness range. A new, simple method has been
proposed to predict earing. Besides simplicity, another major benefit of the method is that it can be applied
to a wide range of sheet thicknesses. The method has been previously applied for unidirectionally rolled and
recrystallized and cross-rolled Al sheets. In the present manuscript, the proposed method is applied on the
AW-5056 type, unidirectionally and cross-rolled, then annealed Al sheets having very weak (close to random)
structure. It is shown that for such samples, the method predicts negligible earing. It is also revealed that for
the 5056 type Al alloy, the differences in texture and earing between unidirectionally and cross-rolled samples
become so small after annealing, that the benefit of cross rolling is negligible
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