| 1. |
- Frydendal, Rasmus, et al.
(författare)
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Benchmarking the Stability of Oxygen Evolution Reaction Catalysts: The Importance of Monitoring Mass Losses
- 2014
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Ingår i: ChemElectroChem. - : Wiley. - 2196-0216. ; 1:12, s. 2075-2081
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Tidskriftsartikel (refereegranskat)abstract
- Because of the rising need for energy storage, potentially facilitatedby electrolyzers, improvements to the catalysis of theoxygen evolution reaction (OER) become increasingly relevant.Standardized protocols have been developed for determiningcritical figures of merit, such as the electrochemical surfacearea, mass activity and specific activity. Even so, when new andmore active catalysts are reported, the catalyst stability tendsto play a minor role. In this work, we monitor corrosion onRuO2 and MnOx by combining the electrochemical quartz crystalmicrobalance (EQCM) with inductively coupled plasma massspectrometry (ICP–MS). We show that a meaningful estimationof the stability cannot be achieved based on purely electrochemicaltests. On the catalysts tested, the anodic dissolutioncurrent was four orders of magnitude lower than the total current.We propose that even if long-term testing cannot be replaced,a useful evaluation of the stability can be achievedwith short-term tests by using EQCM or ICP–MS.
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| 2. |
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| 3. |
- Pedersen, Anders F., et al.
(författare)
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Operando XAS Study of the Surface Oxidation State on a Monolayer IrOx, on RuOx and Ru Oxide Based Nanoparticles for Oxygen Evolution in Acidic Media
- 2018
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 122:2, s. 878-887
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Tidskriftsartikel (refereegranskat)abstract
- Herein we present surface sensitive operando XAS L-edge measurements on IrOx/RuO2 thin films as well as mass-selected RuOx and Ru nanoparticles. We observed shifts of the white line XAS peak toward higher energies with applied electrochemical potential. Apart from the case of the metallic Ru nanoparticles, the observed potential dependencies were purely core-level shifts caused by a change in oxidation state, which indicates no structural changes. These findings can be explained by different binding energies of oxygenated species on the surface of IrOx and RuOx. Simulated XAS spectra show that the average Ir oxidation state change is strongly affected by the coverage of atomic O. The observed shifts in oxidation state suggest that the surface has a high coverage of O at potentials just below the potential where oxygen evolution is exergonic in free energy. This observation is consistent with the notion that the metal-oxygen bond is stronger than ideal.
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| 4. |
- Siahrostami, Samira, 1982, et al.
(författare)
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Enabling direct H2O2 production through rational electrocatalyst design
- 2013
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Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-4660 .- 1476-1122. ; 12:12, s. 1137-1143
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Tidskriftsartikel (refereegranskat)abstract
- Future generations require more efficient and localized processes for energy conversion and chemical synthesis. The continuous on-site production of hydrogen peroxide would provide an attractive alternative to the present state-of-the-art, which is based on the complex anthraquinone process. The electrochemical reduction of oxygen to hydrogen peroxide is a particularly promising means of achieving this aim. However, it would require active, selective and stable materials to catalyse the reaction. Although progress has been made in this respect, further improvements through the development of new electrocatalysts are needed. Using density functional theory calculations, we identify Pt-Hg as a promising candidate. Electrochemical measurements on Pt-Hg nanoparticles show more than an order of magnitude improvement in mass activity, that is, Ag-1 precious metal, for H2O2 production, over the best performing catalysts in the literature.
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| 5. |
- Tiodorovic, Danica, et al.
(författare)
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Dermatoscopic patterns of cutaneous metastases: A multicentre cross-sectional study of the International Dermoscopy Society
- 2024
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Ingår i: JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY AND VENEREOLOGY. - 0926-9959 .- 1468-3083.
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Tidskriftsartikel (refereegranskat)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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| 6. |
- Tognetti, Linda, et al.
(författare)
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A European Multicentric Investigation of Atypical Melanocytic Skin Lesions of Palms and Soles: The iDScore-PalmoPlantar Database
- 2024
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Ingår i: DIAGNOSTICS. - 2075-4418. ; 14:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: The differential diagnosis of atypical melanocytic palmoplantar skin lesions (aMPLs) represents a diagnostic challenge, including atypical nevi (AN) and early melanomas (MMs) that display overlapping clinical and dermoscopic features. We aimed to set up a multicentric dataset of aMPL dermoscopic cases paired with multiple anamnestic risk factors and demographic and morphologic data. Methods: Each aMPL case was paired with a dermoscopic and clinical picture and a series of lesion-related data (maximum diameter value; location on the palm/sole in 17 areas; histologic diagnosis; and patient-related data (age, sex, family history of melanoma/sunburns, phototype, pheomelanin, eye/hair color, multiple/dysplastic body nevi, and traumatism on palms/soles). Results: A total of 542 aMPL cases-113 MM and 429 AN-were collected from 195 males and 347 females. No sex prevalence was found for melanomas, while women were found to have relatively more nevi. Melanomas were prevalent on the heel, plantar arch, and fingers in patients aged 65.3 on average, with an average diameter of 17 mm. Atypical nevi were prevalent on the plantar arch and palmar area of patients aged 41.33 on average, with an average diameter of 7 mm. Conclusions: Keeping in mind the risk profile of an aMPL patient can help obtain a timely differentiation between malignant/benign cases, thus avoiding delayed and inappropriate excision, respectively, with the latter often causing discomfort/dysfunctional scarring, especially at acral sites.
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| 7. |
- Tognetti, Linda, et al.
(författare)
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Dermoscopy of atypical pigmented lesions of the face: Variation according to facial areas.
- 2023
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Ingår i: Experimental dermatology. - 0906-6705 .- 1600-0625. ; 32:12, s. 2166-2172
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Tidskriftsartikel (refereegranskat)abstract
- Atypical pigmented facial lesions (aPFLs)-including lentigo maligna (LM) and lentigo maligna melanoma (LMM), solar lentigo (SL), pigmented actinic keratosis (PAK), atypical nevi (AN), seborrheic keratosis (SK) and lichen planus-like keratosis (LPLK)-can exhibit clinical and dermoscopic overlapping features. We aimed to investigate if and how 14 dermoscopic features suggestive for the aforementioned aPFLs vary according to six facial sites among 1197 aPFLs cases (excised to rule out malignancy) along with lesion and patients' metadata. According to distribution and association analysis, aPFLs on the forehead of a male patient aged>69years displaying the obliterated follicular openings pattern, appear to be more at risk of malignancy. Of converse, aPFLs of the orbital/cheek/nose area with evident and regular follicular openings with diameter<10mm in a female aged below 68 are probably benign. The obliterated follicular openings, keratin plugs, evident and regular follicular openings and target-like pattern features differed significantly among six facial areas in all aPFLs cases. Lesion of the nose may show both features suggestive of malignancy and benignity (e.g. many SL and PAK may display target-like pattern and some LM/LMM cases display keratin plugs and evident and follicular openings), making these features less specific.
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| 8. |
- Tognetti, Linda, et al.
(författare)
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Development and Implementation of a Web-Based International Registry Dedicated to Atypical Pigmented Skin Lesions of the Face: Teledermatologic Investigation on Epidemiology and Risk Factors.
- 2023
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Ingår i: Telemedicine journal and e-health : the official journal of the American Telemedicine Association. - : Mary Ann Liebert Inc. - 1556-3669. ; 29:9, s. 1356-1365
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Tidskriftsartikel (refereegranskat)abstract
- Background: Atypical pigmented facial lesions (aPFLs) often display clinical and dermoscopic equivocal and/or overlapping features, thus causing a challenging and delayed diagnosis and/or inappropriate excisions. No specific registry dedicated to aPFL paired with clinical data is available to date. Methods: The dataset is hosted on a specifically designed web platform. Each complete case was composed of the following data: (1) one dermoscopic picture; (2) one clinical picture; (3) two lesion data, that is, maximum diameter and facial location (e.g., orbital area/forehead/nose/cheek/chin/mouth); (4) patient's demographics: family history of melanoma, history of sunburns in childhood, phototype, pheomelanine, eyes/hair color, multiple nevi/dysplastic nevi on the body; and (5) acquisition device (videodermatoscope/camera-based/smartphone-based system). Results: A total of 11 dermatologic centers contributed to a final teledermoscopy database of 1,197 aPFL with a distribution of 353 lentigo maligna (LM), 146 lentigo maligna melanoma (LMM), 231 pigmented actinic keratoses, 266 solar lentigo, 125 atypical nevi, 48 seborrheic keratosis, and 28 seborrheic-lichenoid keratoses. The cheek site was involved in half of aPFL cases (50%). Compared with those with the other aPFL cases, patients with LM/LMM were predominantly men, older (69.32±12.9 years on average vs. 62.69±14.51), exhibited larger lesions (11.88±7.74mm average maximum diameter vs. 9.33±6.46mm), and reported a positive history of sunburn in childhood. Conclusions: The iDScore facial dataset currently represents a precious source of data suitable for the design of diagnostic support tools based on risk scoring classifiers to help dermatologists in recognizing LM/LMM among challenging aPFL in clinical practice.
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