228 research outputs found

    BRAF wild-type melanoma in situ arising in a BRAF V600E mutant dysplastic nevus

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    IMPORTANCE The BRAF V600E mutation accounts for the majority of BRAF mutations found in cutaneous melanoma and is also commonly found in nevi. We used dermoscopy-targeted sampling and a microbiopsy device coupled with DNA sequence analysis to highlight BRAF V600E heterogeneity within a multicomponent melanocytic proliferation. This sampling technique demonstrates the prospect of in vivo application in a clinical setting

    Detection of metastable electronic states by Penning trap mass spectrometry

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    State-of-the-art optical clocks achieve fractional precisions of 101810^{-18} and below using ensembles of atoms in optical lattices or individual ions in radio-frequency traps. Promising candidates for novel clocks are highly charged ions (HCIs) and nuclear transitions, which are largely insensitive to external perturbations and reach wavelengths beyond the optical range, now becoming accessible to frequency combs. However, insufficiently accurate atomic structure calculations still hinder the identification of suitable transitions in HCIs. Here, we report on the discovery of a long-lived metastable electronic state in a HCI by measuring the mass difference of the ground and the excited state in Re, the first non-destructive, direct determination of an electronic excitation energy. This result agrees with our advanced calculations, and we confirmed them with an Os ion with the same electronic configuration. We used the high-precision Penning-trap mass spectrometer PENTATRAP, unique in its synchronous use of five individual traps for simultaneous mass measurements. The cyclotron frequency ratio RR of the ion in the ground state to the metastable state could be determined to a precision of δR=11011\delta R=1\cdot 10^{-11}, unprecedented in the heavy atom regime. With a lifetime of about 130 days, the potential soft x-ray frequency reference at ν=4.861016Hz\nu=4.86\cdot 10^{16}\,\text{Hz} has a linewidth of only Δν5108Hz\Delta \nu\approx 5\cdot 10^{-8}\,\text{Hz}, and one of the highest electronic quality factor (Q=νΔν1024Q=\frac{\nu}{\Delta \nu}\approx 10^{24}) ever seen in an experiment. Our low uncertainty enables searching for more HCI soft x-ray clock transitions, needed for promising precision studies of fundamental physics in a thus far unexplored frontier

    Review of SIS Experimental Results on Strangeness

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    >A review of meson emission in heavy ion collisions at incident energies around 1 -- 2 AA\cdotGeV is presented. It is shown how the shape of the spectra and the various particle yields vary with system size, with centrality and with incident energy. A statistical model assuming thermal and chemical equilibrium and exact strangeness conservation (i.e. strangeness conservation per collision) explains most of the observed features. Emphasis is put onto the study of K+K^+ and KK^- emission. In the framework of this statistical model it is shown that the experimentally observed equality of K+K^+ and KK^- rates at threshold corrected energies ssth\sqrt{s} - \sqrt{s_{th}} is due to a crossing of two excitation functions. Furthermore, the independence of the K+K^+ to KK^- ratio on the number of participating nucleons observed between 1 and 10 AA\cdotGeV is consistent with this model. The observed flow effects are beyond the scope of this model.Comment: 10 pages, 9 figures, Strangeness 2000, V International Conference on Strangeness in Quark Matter, July, 2000, Berkeley, Californi

    Clinical effectiveness of hymenoptera venom immunotherapy

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    Treatment failure during venom immunotherapy (VIT) may be associated with a variety of risk factors. Our aim was to evaluate the association of baseline serum tryptase concentration (BTC) and of other parameters with the frequency of VIT failure during the maintenance phase. In this observational prospective multicenter study, we followed 357 patients with established honey bee or vespid venom allergy after the maintenance dose of VIT had been reached. In all patients, VIT effectiveness was either verified by sting challenge (n = 154) or patient self-reporting of the outcome of a field sting (n = 203). Data were collected on BTC, age, gender, preventive use of anti-allergic drugs (oral antihistamines and/or corticosteroids) right after a field sting, venom dose, antihypertensive medication, type of venom, side effects during VIT, severity of index sting reaction preceding VIT, and duration of VIT. Relative rates were calculated with generalized additive models. 22 patients (6.2%) developed generalized symptoms during sting challenge or after a field sting. A strong association between the frequency of VIT failure and BTC could be excluded. Due to wide confidence bands, however, weaker effects (odds ratios <3) of BTC were still possible, and were also suggested by a selective analysis of patients who had a sting challenge. The most important factor associated with VIT failure was a honey bee venom allergy. Preventive use of anti-allergic drugs may be associated with a higher protection rate. It is unlikely that an elevated BTC has a strong negative effect on the rate of treatment failures. The magnitude of the latter, however, may depend on the method of effectiveness assessment. Failure rate is higher in patients suffering from bee venom allergy

    BRAFV600E Mutation Status of Involuting and Stable Nevi in Dabrafenib Therapy with or without Trametinib

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    IMPORTANCE Recent advances in targeting BRAF(V600E) mutations, which occur in roughly 50% of melanomas and 70% of benign nevi, have improved response rates and survival in patients with melanoma. With increased survival, the importance of other comorbidities increases and requires consideration in long-term management. This case report discusses dynamic dermoscopic nevus changes that occur during dabrafenib therapy and offers some conclusions regarding BRAF mutations and the changes

    Contribución al conocimiento de los machiloidea de colombia (archaeognatha: insecta)

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    Four new species and one new subspecies of Meinertellidae occurring respectively in Colombia and in the rain forest near Manaus, Brazil, are described:  Meinertellus adisi, M. bogotensis santaemartae , Neomachilellus abouchaari, N. amazonicus and N. rangeli. The systematical position of specimens collected near Bogota, in the Magdalena Valley and in the Eastern Andes near Neiva is discussed. A key for the South American genera of the family is given.Se describen cuatro nuevas especies y una subespecie de Meinertellidae recolectadas en Colombia y en un bosque pluvial cerca de Manaos, Brasil. Son las siguientes: Meinertellus adisi, M. bogotensis santaemartae, Neomachilellus aboucbaari, N. amazonicus y N. rangeli. Se discute la posición sistemática de los ejemplares recolectados cerca de Bogotá, en el valle del río Magdalena y en la Cordillera Oriental cerca de Neiva. Se da una clave para los géneros suramericanos de la familia

    ERIS: revitalising an adaptive optics instrument for the VLT

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    ERIS is an instrument that will both extend and enhance the fundamental diffraction limited imaging and spectroscopy capability for the VLT. It will replace two instruments that are now being maintained beyond their operational lifetimes, combine their functionality on a single focus, provide a new wavefront sensing module that makes use of the facility Adaptive Optics System, and considerably improve their performance. The instrument will be competitive with respect to JWST in several regimes, and has outstanding potential for studies of the Galactic Center, exoplanets, and high redshift galaxies. ERIS had its final design review in 2017, and is expected to be on sky in 2020. This contribution describes the instrument concept, outlines its expected performance, and highlights where it will most excel.Comment: 12 pages, Proc SPIE 10702 "Ground-Based and Airborne Instrumentation for Astronomy VII

    Genomics: Think Global, Act Local

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    Long a slogan for environmentalists, “think global, act local” could be a new rallying cry for biologists. As genome-wide techniques advance and their costs drop, scientists are expanding into larger and larger territories—metagenomics, global proteomic approaches, and analyses of thousands of genomes. These massive data sets are opening up new possibilities for understanding some of the smallest details of the genome. Here, we look at four such cases—investigating the evolutionary role of insertions and deletions in the genome, connecting an orphan enzyme with its gene, mapping the fine details of chromatin structure, and characterizing global interactions between proteins and RNA—all of which depend on a combination of global thinking and local action
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