20 research outputs found

    Venae perforantes: A clinical review

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    BACKGROUND. Although many articles on perforating veins have been published, much knowledge about these veins is lacking. OBJECTIVE. In this review relevant facts about the clinical importance of perforating veins in venous disease are described. METHODS. A literature search on English, French and German articles has been performed using literature databases like Medline, Embase and Cochrane. RESULTS. Selection criteria are described. CONCLUSION. A few conclusions are drawn: incompetent perforating veins can be of haemodynamic importance, especially in venous ulceration and (recurrent) varicose veins. The current definition of incompetent perforating veins is reflux more than 0,5 seconds (detected by Duplex ultra-sonography). Good anatomical and clinical classifications are published and should be integrated in the CEAP classification. Based on the clinical classification treatment options are described for the different types of incompetent perforating veins. Two different treatment modalities for incompetent perforating veins are surgery (SEPS) and sclerotherapy. SEPS seems to be of benefit in patients with venous ulceration and advanced CVI. Sclerotherapy (especially ultra sound guided sclerotherapy) is promising and worth further evaluation

    The IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope Array: Joint Contribution to the 34th International Cosmic Ray Conference (ICRC 2015)

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    We have conducted three searches for correlations between ultra-high energy cosmic rays detected by the Telescope Array and the Pierre Auger Observatory, and high-energy neutrino candidate events from IceCube. Two cross-correlation analyses with UHECRs are done: one with 39 cascades from the IceCube `high-energy starting events' sample and the other with 16 high-energy `track events'. The angular separation between the arrival directions of neutrinos and UHECRs is scanned over. The same events are also used in a separate search using a maximum likelihood approach, after the neutrino arrival directions are stacked. To estimate the significance we assume UHECR magnetic deflections to be inversely proportional to their energy, with values 33^\circ, 66^\circ and 99^\circ at 100 EeV to allow for the uncertainties on the magnetic field strength and UHECR charge. A similar analysis is performed on stacked UHECR arrival directions and the IceCube sample of through-going muon track events which were optimized for neutrino point-source searches.Comment: one proceeding, the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands; will appear in PoS(ICRC2015

    The IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope Array:Joint Contribution to the 34th International Cosmic Ray Conference (ICRC 2015)

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    We have conducted three searches for correlations between ultra-high energy cosmic rays detected by the Telescope Array and the Pierre Auger Observatory, and high-energy neutrino candidate events from IceCube. Two cross-correlation analyses with UHECRs are done: one with 39 cascades from the IceCube `high-energy starting events' sample and the other with 16 high-energy `track events'. The angular separation between the arrival directions of neutrinos and UHECRs is scanned over. The same events are also used in a separate search using a maximum likelihood approach, after the neutrino arrival directions are stacked. To estimate the significance we assume UHECR magnetic deflections to be inversely proportional to their energy, with values 33^\circ, 66^\circ and 99^\circ at 100 EeV to allow for the uncertainties on the magnetic field strength and UHECR charge. A similar analysis is performed on stacked UHECR arrival directions and the IceCube sample of through-going muon track events which were optimized for neutrino point-source searches

    The IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope Array:Joint Contribution to the 34th International Cosmic Ray Conference (ICRC 2015)

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    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Photodynamic therapy versus topical imiquimod versus topical fluorouracil for treatment of superficial basal-cell carcinoma: a single blind, non-inferiority, randomised controlled trial

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    Background Superficial basal-cell carcinoma is most commonly treated with topical non-surgical treatments, such as photodynamic therapy or topical creams. Photodynamic therapy is considered the preferable treatment, although this has not been previously tested in a randomised control trial. We assessed the effectiveness of photodynamic therapy compared with imiquimod or fluorouracil in patients with superficial basal-cell carcinoma. Methods In this single blind, non-inferiority, randomised controlled multicentre trial, we enrolled patients with a histologically proven superficial basal-cell carcinoma at seven hospitals in the Netherlands. Patients were randomly assigned to receive treatment with methylaminolevulinate photodynamic therapy (MAL-PDT; two sessions with an interval of 1 week), imiquimod cream (once daily, five times a week for 6 weeks), or fluorouracil cream (twice daily for 4 weeks). Follow-up was at 3 and 12 months post-treatment. Data were collected by one observer who was blinded to the assigned treatment. The primary outcome was the proportion of patients free of tumour at both 3 and 12 month follow up. A pre-specified non-inferiority margin of 10% was used and modified intention-to-treat analyses were done. This trial is registered as an International Standard Randomised controlled trial (ISRCTN 79701845). Findings 601 patients were randomised: 202 to receive MAL-PDT, 198 to receive imiquimod, and 201 to receive fluorouracil. A year after treatment, 52 of 196 patients treated with MAL-PDT, 31 of 189 treated with imiquimod, and 39 of 198 treated with fluorouracil had tumour residue or recurrence. The proportion of patients tumour-free at both 3 and 12 month follow-up was 72.8% (95% CI 66.8-79.4) for MAL-PDT, 83.4% (78.2-88.9) for imiquimod cream, and 80.1% (74.7-85.9) for fluorouracil cream. The difference between imiquimod and MAL-PDT was 10.6% (95% CI 1.5-19.5; p=0.021) and 7.3% (-1.9 to 16.5; p=0.120) between fluorouracil and MAL-PDT, and between fluorouracil and imiquimod was -3.3% (-11.6 to 5.0; p=0.435. For patients treated with MAL-PDT, moderate to severe pain and burning sensation were reported most often during the actual MAL-PDT session. For other local adverse reactions, local skin redness was most often reported as moderate or severe in all treatment groups. Patients treated with creams more often reported moderate to severe local swelling, erosion, crust formation, and itching of the skin than patients treated with MAL-PDT. In the MAL-PDT group no serious adverse events were reported. One patient treated with imiquimod and two patients treated with fluorouracil developed a local wound infection and needed additional treatment in the outpatient setting. Interpretation Topical fluorouracil was non-inferior and imiquimod was superior to MAL-PDT for treatment of superficial basal-cell carcinoma. On the basis of these findings, imiquimod can be considered the preferred treatment, but all aspects affecting treatment choice should be weighted to select the best treatment for patients
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