116 research outputs found

    Velocity-selective sublevel resonance of atoms with an array of current-carrying wires

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    Resonance transitions between the Zeeman sublevels of optically-polarized Rb atoms traveling through a spatially periodic magnetic field are investigated in a radio-frequency (rf) range of sub-MHz. The atomic motion induces the resonance when the Zeeman splitting is equal to the frequency at which the moving atoms feel the magnetic field oscillating. Additional temporal oscillation of the spatially periodic field splits a motion-induced resonance peak into two by an amount of this oscillation frequency. At higher oscillation frequencies, it is more suitable to consider that the resonance is mainly driven by the temporal field oscillation, with its velocity-dependence or Doppler shift caused by the atomic motion through the periodic field. A theoretical description of motion-induced resonance is also given, with emphasis on the translational energy change associated with the internal transition.Comment: 7 pages, 3 figures, final versio

    Co-producing principles to guide health research: an illustrative case study from an eating disorder research clinic

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    There is significant value in co-produced health research, however power-imbalances within research teams can pose a barrier to people with lived experience of an illness determining the direction of research in that area. This is especially true in eating disorder research, where the inclusion of co-production approaches lags other research areas. Appealing to principles or values can serve to ground collaborative working. Despite this, there has not been any prior attempt to co-produce principles to guide the work of a research group and serve as a basis for developing future projects. The aim of this piece of work was to co-produce a set of principles to guide the conduct of research within our lived experience led research clinic, and to offer an illustrative case for the value of this as a novel co-production methodology. A lived experience panel were recruited to our eating disorder research group. Through an iterative series of workshops with the members of our research clinic (composed of a lived experience panel, clinicians, and researchers) we developed a set of principles which we agreed were important in ensuring both the direction of our research, and the way in which we wanted to work together. Six key principles were developed using this process. They were that research should aim to be: 1) real world—offering a clear and concrete benefit to people with eating disorders, 2) tailored—suitable for marginalised groups and people with atypical diagnoses, 3) hopeful—ensuring that hope for recovery was centred in treatment, 4) experiential—privileging the ‘voice’ of people with eating disorders, 5) broad—encompassing non-standard therapeutic treatments and 6) democratic—co-produced by people with lived experience of eating disorders. We reflect on some of the positives as well as limitations of the process, highlighting the importance of adequate funding for longer-term co-production approaches to be taken, and issues around ensuring representation of minority groups. We hope that other health research groups will see the value in co-producing principles to guide research in their own fields, and will adapt, develop, and refine this novel methodology

    Bloch-Like Quantum Multiple Reflections of Atoms

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    We show that under certain circumstances an atom can follow an oscillatory motion in a periodic laser profile with a Gaussian envelope. These oscillations can be well explained by using a model of energetically forbidden spatial regions. The similarities and differences with Bloch oscillations are discussed. We demonstrate that the effect exists not only for repulsive but also for attractive potentials, i.e. quantum multiple reflections are also possible.Comment: LaTeX, 7 pages, 7 figure

    Determination of the gamma emission probabilities of 239

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    239Np is an important nuclide as the decay daughter of 239U and it decays to 239Pu by emitting beta particles and gamma rays with a half life of 2.356 days. The data of the emission probabilities of its gamma-rays in the open references are consistent except for the main gamma-ray of 106.1 keV, the emission probability of which varies from 25.9% to 27.2%. To verify the emission probability of 106.1 keV gamma-ray of 239Np, a N-type coaxial HPGe detector was calibrated using 241Am, 133Ba, 60Co, 152Eu and 155Eu reference gamma sources to get the accurate efficiency of the 106.1 keV gamma-ray. 239Np was purified from solution containing 243Am, where 239Np is the alpha decay daughter of 243Am. The specific activity of 239Np solution was determined by a 4πβ (PC)-γ coincidence counting device. There were 6 gamma sources prepared to measure with the HPGe detector, and the activity of 239Np in each gamma source was calculated with the weights of the solution contained in it. The emission probability of 106.1 keV of 239Np is measured to be (25.4 ± 0.3)%, which is consistent with 25.34%, the value evaluated in 2014

    Broad targeting of resistance to apoptosis in cancer

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    Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

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    Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

    Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images

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    Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL maps are derived through computational staining using a convolutional neural network trained to classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and correlation with overall survival. TIL map structural patterns were grouped using standard histopathological parameters. These patterns are enriched in particular T cell subpopulations derived from molecular measures. TIL densities and spatial structure were differentially enriched among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for the TCGA image archives with insights into the tumor-immune microenvironment

    Manganese and cobalt redox cycling in laterites; Biogeochemical and bioprocessing implications

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    This research was developed during the PhD studies of Agustín Solano Arguedas in the University of Manchester, United Kingdom. PhD scholarship was funded by the Ministerio de Ciencia, Tecnología y Telecomunicaciones (MICITT) of the Government of Costa Rica and the Universidad de Costa Rica (UCR). Agustín Solano Arguedas is a researcher at the Unidad de Recursos Forestales (Reforesta, Unit of Forest Resources) of the Instituto de Investigaciones en Ingeniería (INII, Engineering Research Institute), UCR.Cobalt is essential for the modern technology that underpins the decarbonisation of our economies, but its supply is limited leading to its designation as a critical metal. Cobalt biogeochemistry is poorly understood, yet knowledge of how biogeochemical cycling impacts cobalt behaviour could assist the development of new techniques to recover cobalt from ores, and so improve the security of supply. Laterites are an important source of cobalt, they are primarily processed for nickel using energy or chemical intensive processes, with cobalt recovered as a by-product. Metal-reducing conditions were stimulated in laterite sediment microcosms by the addition of simple and cheaply available organic substrates (acetate or glucose). At the end of the experiment the amount of easily recoverable cobalt (aqueous or extractable with acetic acid) increased from < 1% to up to 64%, which closely mirrored the behaviour of manganese, while only a small proportion of iron was transformed into an easily recoverable phase. Sequencing of the microbial community showed that the addition of organic substrates stimulated the growth of indigenous prokaryotes closely related to known manganese(IV)/iron(III)-reducers, particularly from the Clostridiales, and that fungi assigned to Penicillium, known to produce organic acids beneficial for leaching cobalt and nickel from laterites, were identified. Overall, the results indicate that the environmental behaviour of cobalt in laterites is likely to be controlled by manganese biogeochemical cycling by microorganisms. These results are compelling given that similar behaviour was observed in four laterites (Acoje, Çaldağ, Piauí and Shevchenko) from different continents. A new bioprocessing strategy is proposed whereby laterites are treated with an organic substrate to generate metal-reducing conditions, then rinsed with acetic acid to remove the cobalt. Not only are organic substrates environmentally-friendly and potentially sourced from waste carbon substrates, a minimal amount of iron oxides was mobilised and consequently less waste generated.Natural Environment Research Council/[CoG3 NE/M011518/1]/NERC/Reino UnidoDiamond Light Source/[SP16735]//Reino UnidoDiamond Light Source/[SP17313]//Reino UnidoOffice of Science User Facility/[DE-AC02-05CH11231]//Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ingeniería::Instituto Investigaciones en Ingeniería (INII
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