| 1. |
- Brunsell, Per, et al.
(author)
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Feedback stabilization of resistive wall modes in a reversed-field pinch
- 2005
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In: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 12:9, s. 092508-
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Journal article (peer-reviewed)abstract
- An array of saddle coils having Nc =16 equally spaced positions along the toroidal direction has been installed for feedback control of resistive wall modes (RWMs) on the EXTRAP T2R reversed-field pinch [P. R. Brunsell, H. Bergsaker, M. Cecconello, Plasma Phys. Controlled Fusion 43, 1457 (2001)]. Using feedback, multiple nonresonant RWMs are simultaneously suppressed for three to four wall times. Feedback stabilization of RWMs results in a significant prolongation of the discharge duration. This is linked to a better sustainment of the plasma and tearing mode toroidal rotation with feedback. Due to the limited number of coils in the toroidal direction, pairs of modes with toroidal mode numbers n, n′ that fulfill the condition ∫n- n′ ∫ = Nc are coupled by the feedback action from the discrete coil array. With only one unstable mode in a pair of coupled modes, the suppression of the unstable mode is successful. If two modes are unstable in a coupled pair, two possibilities exist: partial suppression of both modes or, alternatively, complete stabilization of one target mode while the other is left unstable.
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| 2. |
- de Amorim Lima, Nayane Maria, et al.
(author)
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Light-Emitting Porphyrin Derivative Obtained from a Subproduct of the Cashew Nut Shell Liquid : A Promising Material for OLED Applications
- 2019
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In: Materials. - : MDPI. - 1996-1944. ; 12:7
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Journal article (peer-reviewed)abstract
- In this work, the meso-tetra[4-(2-(3-n-pentadecylphenoxy)ethoxy]phenylporphyrin (H2P), obtained from the cashew nut shell liquid (CNSL), and its zinc (ZnP) and copper (CuP) metallic complexes, were applied as emitting layers in organic light emitting diodes (OLEDs). These compounds were characterized via optical and electrochemical analysis and the electroluminescent properties of the device have been studied. We performed a cyclic voltammetry analysis to determine the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energy levels for the porphyrins, in order to select the proper materials to assemble the device. H2P and ZnP presented fluorescence emission band in the red region, from 601 nm to 718 nm. Moreover, we verified that the introduction of bulky substituents hinders the - stacking, favoring the emission in the film. In addition, the strongest emitter, ZnP, presented a threshold voltage of 4 V and the maximum irradiance of 10 W cm(-2) with a current density (J) of 15 mA cm(-2) at 10 V. The CuP complex showed to be a favorable material for the design of OLEDs in the infrared. These results suggest that the porphyrins derived from a renewable source, such as CNSL, is a promising material to be used in organic optoelectronic devices such as OLEDs.
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| 3. |
- Ibrahim, Abdulhakim, et al.
(author)
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Post-implantation syndrome after frozen elephant trunk is associated with the volume of new-onset aortic thrombus
- 2021
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In: Journal of Thoracic Disease. - : AME PUBL CO. - 2072-1439 .- 2077-6624. ; 13:7, s. 4311-4321
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Journal article (peer-reviewed)abstract
- Background: Post-implantation syndrome (PIS) is defined as non-infectious continuous fever and a concomitant rise in inflammatory markers shortly after endovascular aortic repair. PIS occurrence after hybrid procedures, such as the frozen elephant trunk (FET) technique, has not been adequately investigated. The current study aims to define the incidence of PIS after the FET and to identify possible risk factors associated with its occurrence. Methods: The clinical charts of 59 patients undergoing the FET between February 2015 and April 2020 were reviewed retrospectively. The occurrence of PIS was defined as the presence of fever (>38 degrees C lasting longer than one day during the hospitalisation) and leucocytosis (white blood cell count >12,000/mu L). Patients with concomitant conditions possibly leading to fever and/or leucocytosis were excluded. Beside demographic and procedure-related data, serum/plasma inflammatory markers were evaluated before surgery and daily up to seven days postoperatively. Computed tomography scans (CT) were examined to calculate the volume of pre-existent and new-onset mural thrombus after the FET. Results: Thirty-eight patients met the inclusion criteria. The study cohort was divided into two groups based on the occurrence of PIS (17 cases; 44.7%). Patients with PIS were significantly younger than those without PIS (53.5 +/- 8.9 vs. 62.5 +/- 9.6 years; P=0.005). Female patients were less likely to develop PIS (5.2% vs. 26.3%, P=0.018). Patients with PIS had a higher volume of new-onset thrombus in the postoperative CT (P<0.001). Patients treated for post-dissection aneurysm had, postoperatively, significantly more thrombus material developed in a false lumen (P=0.02). Among the PIS markers, CRP (C-reactive protein) levels on the third postoperative day were independently associated with the volume of new-onset thrombus (P=0.011). After multivariate analysis, the volume of new-onset thrombus (P=0.028) and age (P=0.036) remained the variable associated with a statistically significant increased incidence of PIS. Conclusions: PIS can occur after the frozen elephant trunk procedure. The volume of new-onset thrombus seems to be associated with an increased incidence of PIS. These findings need to be confirmed in larger patient cohorts.
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| 4. |
- Olofsson, K. Erik J., et al.
(author)
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Subspace identification analysis of RFX and T2R reversed-field pinches
- 2013
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In: Control Engineering Practice. - : Elsevier BV. - 0967-0661 .- 1873-6939. ; 21:7, s. 917-929
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Journal article (peer-reviewed)abstract
- Input-output datasets from two magnetic confinement fusion (MCF) experiments of the reversed-field pinch (RFP) type are examined. The RFP datasets, which are samples of the distributed magnetic field dynamics, are naturally divided into many smaller batches due to the pulsed-plasma operation of the experiments. The two RFP experiments considered are (i) EXTRAP T2R (T2R) with 64 inputs and 64 outputs and (ii) RFX-mod (RFX) with 192 inputs and 192 outputs. Both T2R and RFX are magnetohydrodynamically unstable and operates under magnetic feedback with optional dither injection. Using subspace system identification techniques and randomised cross-validation (CV) methods to minimise the generalisation error, state-space orders of the empirical systems are suggested. These system orders are compared to "stabilisation diagrams" commonly used in experimental modal analysis practice. The relation of the CV system order to the decay of the singular values from the subspace method is observed. Both (i) stable vacuum diffusion and (ii) unstable plasma response datasets are analysed. Apparent simulation and prediction errors are quantified for both cases using a deviation-accounted-for index. These results are purely data-driven. A simple approach towards exploitation of the subspace techniques for finite-element model refinement and data confrontation is presented.
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| 5. |
- Russo, Teresa, et al.
(author)
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Indications for Digital Monitoring of Patients With Multiple Nevi: Recommendations from the International Dermoscopy Society
- 2022
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In: Dermatology Practical and Conceptual. - : Mattioli1885. - 2160-9381. ; 12
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Journal article (peer-reviewed)abstract
- Introduction: In patients with multiple nevi, sequential imaging using total body skin photography (TBSP) coupled with digital dermoscopy (DD) documentation reduces unnecessary excisions and improves the early detection of melanoma. Correct patient selection is essential for optimizing the efficacy of this diagnostic approach. Objectives: The purpose of the study was to identify, via expert consensus, the best indications for TBSP and DD follow-up. Methods: This study was performed on behalf of the International Dermoscopy Society (IDS). We attained consensus by using an e-Delphi methodology. The panel of participants included international experts in dermoscopy. In each Delphi round, experts were asked to select from a list of indications for TBSP and DD. Results: Expert consensus was attained after 3 rounds of Delphi. Participants considered a total nevus count of 60 or more nevi or the presence of a CDKN2A mutation sufficient to refer the patient for digital monitoring. Patients with more than 40 nevi were only considered an indication in case of personal history of melanoma or red hair and/or a MC1R mutation or history of organ transplantation. Conclusions: Our recommendations support clinicians in choosing appropriate follow-up regimens for patients with multiple nevi and in applying the time-consuming procedure of sequential imaging more efficiently. Further studies and real-life data are needed to confirm the usefulness of this list of indications in clinical practice.
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| 6. |
- Tiodorovic, Danica, et al.
(author)
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Dermatoscopic patterns of cutaneous metastases: A multicentre cross-sectional study of the International Dermoscopy Society
- 2024
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In: JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY AND VENEREOLOGY. - 0926-9959 .- 1468-3083.
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Journal article (peer-reviewed)abstract
- BackgroundThe detection of cutaneous metastases (CMs) from various primary tumours represents a diagnostic challenge.ObjectivesOur aim was to evaluate the general characteristics and dermatoscopic features of CMs from different primary tumours.MethodsRetrospective, multicentre, descriptive, cross-sectional study of biopsy-proven CMs.ResultsWe included 583 patients (247 females, median age: 64 years, 25%-75% percentiles: 54-74 years) with 632 CMs, of which 52.2% (n = 330) were local, and 26.7% (n = 169) were distant. The most common primary tumours were melanomas (n = 474) and breast cancer (n = 59). Most non-melanoma CMs were non-pigmented (n = 151, 95.6%). Of 169 distant metastases, 54 (32.0%) appeared on the head and neck region. On dermatoscopy, pigmented melanoma metastases were frequently structureless blue (63.6%, n = 201), while amelanotic metastases were typified by linear serpentine vessels and a white structureless pattern. No significant difference was found between amelanotic melanoma metastases and CMs of other primary tumours.ConclusionsThe head and neck area is a common site for distant CMs. Our study confirms that most pigmented melanoma metastasis are structureless blue on dermatoscopy and may mimic blue nevi. Amelanotic metastases are typified by linear serpentine vessels and a white structureless pattern, regardless of the primary tumour.
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