907 research outputs found
Identifying Reasons for a Lack of Method Application in Engineering Design Practice – An Interview Study
Design methods are seldom used in engineering design practice. The presented study aims at finding the alternative strategies for situations with a need for methodological support. Semi-structured interviews were conducted with ten experienced design engineers to identify causes of and strategies for those situations. Three strategy clusters could be identified: generating information, experience and method application. As the individual\u27s and the team\u27s experience compete with the application of methods, they are seen as reasons for a lack of method application
Direct Measurement of Quantum Dot Spin Dynamics using Time-Resolved Resonance Fluorescence
We temporally resolve the resonance fluorescence from an electron spin
confined to a single self-assembled quantum dot to measure directly the spin's
optical initialization and natural relaxation timescales. Our measurements
demonstrate that spin initialization occurs on the order of microseconds in the
Faraday configuration when a laser resonantly drives the quantum dot
transition. We show that the mechanism mediating the optically induced
spin-flip changes from electron-nuclei interaction to hole-mixing interaction
at 0.6 Tesla external magnetic field. Spin relaxation measurements result in
times on the order of milliseconds and suggest that a magnetic field
dependence, due to spin-orbit coupling, is sustained all the way down to 2.2
Tesla.Comment: An additional EPAPS file in PDF format is available for download at
the publications section of our website
http://www.amop.phy.cam.ac.uk/amop-ma
Deep sequencing analysis reveals distinctive non-coding RNAs when comparing tumor multidrug-resistant cells and extracellular vesicles with drug-sensitive counterparts
This article is a result of the project NORTE-01-0145-FEDER-000029, supported by the Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work was partially financed by the FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). This work is also a result of the GenomePT project (POCI-01-0145-FEDER-022184), supported by the COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT). The authors thank the Portuguese Foundation for Science and Technology (FCT) for the PhD grant of DS (SFRH/BD/98054/2013).Multidrug resistance (MDR) is one of the main limitations of cancer treatment. The overexpression of drug-eux pumps, such as P-glycoprotein (P-gp), is a major cause of MDR. Importantly, di erent studies have shown that extracellular vesicles (EVs) participate in the communication between MDR cells and drug-sensitive counterparts, promoting dissemination of the MDR phenotype. In the present work, we aimed to identify RNA species present in MDR cells and in EVs released by those cells, which may be associated with the MDR phenotype. The RNA content from two pairs (leukemia and lung cancer) of MDR (P-gp overexpressing) cells and their drug-sensitive counterparts, as well as from their EVs, was analyzed by deep sequencing. Our results showed distinctive transcripts for MDR cells and their EVs, when compared with their drug-sensitive counterparts. Remarkably, two pseudogenes (a novel pseudogene and RNA 5.8S ribosomal pseudogene 2) were found to be increased in EVs released by MDR cells in both leukemia and lung cancer models. Moreover, six miRs (miR-204-5p, miR-139-5p, miR-29c-5p, miR-551b-3p, miR-29b-2-5p, and miR-204-3p) exhibited altered levels in lung cancer MDR cells and their EVs. This study provides insights into the contribution of EVs to MDR.publishersversionpublishe
Trapping electrons in a room-temperature microwave Paul trap
We demonstrate trapping of electrons in a millimeter-sized quadrupole Paul
trap driven at 1.6~GHz in a room-temperature ultra-high vacuum setup. Cold
electrons are introduced into the trap by ionization of atomic calcium via
Rydberg states and stay confined by microwave and static electric fields for
several tens of milliseconds. A fraction of these electrons remain trapped
longer and show no measurable loss for measurement times up to a second.
Electronic excitation of the motion reveals secular frequencies which can be
tuned over a range of several tens to hundreds of MHz. Operating a similar
electron Paul trap in a cryogenic environment may provide a platform for
all-electric quantum computing with trapped electron spin qubits.Comment: Version accepted by PR
Current Challenges And Solution Approaches In Empirical Engineering Design Research – A Workshop For Empirical Research
The requirements on validity for studies in design research are very high. Therefore, this paper aims at identifying challenges that occur when setting up studies and suggests solution strategies to address them. Three different institutes combining their experience discussed several studies in a workshop. Resulting main challenges are to find a suitable task, to operationalise the variables and to deal with a high analysis effort per participant. Automation in data evaluation and a detailed practical guideline on studies in design research are considered necessary
Direct photonic coupling of a semiconductor quantum dot and a trapped ion.
Coupling individual quantum systems lies at the heart of building scalable quantum networks. Here, we report the first direct photonic coupling between a semiconductor quantum dot and a trapped ion and we demonstrate that single photons generated by a quantum dot controllably change the internal state of a Yb^{+} ion. We ameliorate the effect of the 60-fold mismatch of the radiative linewidths with coherent photon generation and a high-finesse fiber-based optical cavity enhancing the coupling between the single photon and the ion. The transfer of information presented here via the classical correlations between the σ_{z} projection of the quantum-dot spin and the internal state of the ion provides a promising step towards quantum-state transfer in a hybrid photonic network.We acknowledge support by the University of Cambridge,
the Alexander-von-Humboldt Stiftung, EPSRC
(EP/H005676/1), the European Research Council (Grant
numbers 240335 and 617985), EU-FP7 Marie Curie Initial
Training Networks COMIQ and S3NANO.This is the accepted manuscript. The final version is available at http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.123001
Aural CT characteristics of American Cocker Spaniels have features of both mesaticephalic and brachycephalic breeds
Otitis externa and otitis media are common in American Cocker Spaniels, however breed-specific aural CT descriptions are currently lacking. This prospective and retrospective, observational, analytical study aimed to describe quantitative CT characteristics of the horizontal ear canal and the tympanic bulla in American Cocker Spaniels versus similar-sized mesaticephalic dogs. We prospectively performed clinical examinations and aural CT scanning for 38 American Cocker Spaniels. Computed tomographic transverse area of the osseous horizontal ear canal (TA1), transverse area of the widest air-filled part of the cartilaginous horizontal ear canal (TA2), tympanic bulla volume, and tympanic bulla wall thickness were measured. The TA1 and TA2 measurements were compared with those of 23 retrospectively recruited, similar-sized mesaticephalic dogs that had undergone CT-scanning of the head for non-ear-related reasons. The TA1 and TA2 did not differ for healthy American Cocker Spaniels and mesaticephalic dogs. Severely affected American Cocker Spaniels had significantly smaller TA2 (P <.001). The intraclass correlation coefficient for intraobserver and interobserver repeatability was 0.972 and 0.983 for TA1 and 0.994 and 0.998 for TA2, respectively. Variation between individuals was subjectively noted in healthy and affected American Cocker Spaniels, but mean tympanic bulla volume was slightly smaller in relation to body weight, and the tympanic bulla wall was thicker than in previous reports for mesaticephalic dogs. The tympanic bulla wall appeared thicker rostro-ventrally than caudo-ventrally in 44% of the dogs. Our results imply that a relatively thick tympanic bulla wall may be a normal CT variation and should be interpreted cautiously in this breed.Peer reviewe
Assessment of a Large-Scale Unbiased Malignant Pleural Effusion Proteomics Study of a Real-Life Cohort
Background: Pleural effusion (PE) is common in advanced-stage lung cancer patients
and is related to poor prognosis. Identification of cancer cells is the standard method for the
diagnosis of a malignant PE (MPE). However, it only has moderate sensitivity. Thus, more sensitive
diagnostic tools are urgently needed. Methods: The present study aimed to discover potential protein
targets to distinguish malignant pleural effusion (MPE) from other non-malignant pathologies. We
have collected PE from 97 patients to explore PE proteomes by applying state-of-the-art liquid
chromatography-mass spectrometry (LC-MS) to identify potential biomarkers that correlate with
immunohistochemistry assessment of tumor biopsy or with survival data. Functional analyses
were performed to elucidate functional differences in PE proteins in malignant and benign samples.
Results were integrated into a clinical risk prediction model to identify likely malignant cases.
Sensitivity, specificity, and negative predictive value were calculated. Results: In total, 1689 individual
proteins were identified by MS-based proteomics analysis of the 97 PE samples, of which 35 were
diagnosed as malignant. A comparison between MPE and benign PE (BPE) identified 58 differential
regulated proteins after correction of the p-values for multiple testing. Furthermore, functional
analysis revealed an up-regulation of matrix intermediate filaments and cellular movement-related
proteins. Additionally, gene ontology analysis identified the involvement of metabolic pathways
such as glycolysis/gluconeogenesis, pyruvate metabolism and cysteine and methionine metabolism.
Conclusion: This study demonstrated a partial least squares regression model with an area under the
curve of 98 and an accuracy of 0.92 when evaluated on the holdout test data set. Furthermore, highly
significant survival markers were identified (e.g., PSME1 with a log-rank of 1.68 × 10−6
).info:eu-repo/semantics/publishedVersio
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