“…3b ). The latter analysis confirmed also that even though SEM-EDS analysis is useful when characterizing unknown materials [ 23 – 28 ], it is only the combination with XRD analysis that allows for unambiguous identifications of inorganic compounds [ 29 – 33 ]. Fig.…”
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron loss and widespread muscular atrophy. Despite intensive investigations on genetic and environmental factors, the cause of ALS remains unknown. Recent data suggest a role for metal exposures in ALS causation. In this study we present a patient who developed ALS after a traditional medical procedure in Kenya. The procedure involved insertion of a black metal powder into several subcutaneous cuts in the lower back. Four months later, general muscle weakness developed. Clinical and electrophysiological examinations detected widespread denervation consistent with ALS. The patient died from respiratory failure less than a year after the procedure. Scanning electron microscopy and X-ray diffraction analyses identified the black powder as potassium permanganate (KMnO4). A causative relationship between the systemic exposure to KMnO4 and ALS development can be suspected, especially as manganese is a well-known neurotoxicant previously found to be elevated in cerebrospinal fluid from ALS patients. Manganese neurotoxicity and exposure routes conveying this toxicity deserve further attention.
“…3b ). The latter analysis confirmed also that even though SEM-EDS analysis is useful when characterizing unknown materials [ 23 – 28 ], it is only the combination with XRD analysis that allows for unambiguous identifications of inorganic compounds [ 29 – 33 ]. Fig.…”
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron loss and widespread muscular atrophy. Despite intensive investigations on genetic and environmental factors, the cause of ALS remains unknown. Recent data suggest a role for metal exposures in ALS causation. In this study we present a patient who developed ALS after a traditional medical procedure in Kenya. The procedure involved insertion of a black metal powder into several subcutaneous cuts in the lower back. Four months later, general muscle weakness developed. Clinical and electrophysiological examinations detected widespread denervation consistent with ALS. The patient died from respiratory failure less than a year after the procedure. Scanning electron microscopy and X-ray diffraction analyses identified the black powder as potassium permanganate (KMnO4). A causative relationship between the systemic exposure to KMnO4 and ALS development can be suspected, especially as manganese is a well-known neurotoxicant previously found to be elevated in cerebrospinal fluid from ALS patients. Manganese neurotoxicity and exposure routes conveying this toxicity deserve further attention.
“…Samples of metal-wrapped threads from seventeen different textiles were analyzed to characterize the compositions of the metal strips used to cover the threads [15,18]. Twenty-(See figure on previous page.)…”
Section: Metal-wrapped Threadsmentioning
confidence: 99%
“…Some studies concentrated on qualitative compositional characterization of the metal strips, typically silver-gilt [12][13][14]. Other studies have also used SEM-EDS for quantitative compositional analyses and characterization of the layer structures of giltsilver as well as silvered copper, and more modern metal wrappings made with brass coated copper or aluminum foil [15,16]. While most compositional analysis of metal wrappings has been done with SEM-EDS, some have also supplemented this with wavelength dispersive X-ray spectrometry (WDS) quantitative analysis of the interiors of the metal strips to get better results on the minor elements which may be below the minimum detection limits of SEM-EDS [17].…”
Introduction: Analyses of natural dyes and the metal of the metal-wrapping threads used in 16 th -18 th century Persian/Safavid and Indian/Mughal period velvets were performed on these textiles in the collection of The Metropolitan Museum of Art. The purpose was to determine whether velvets from the two cultures, which have shown problems in the past with attribution based on historical and iconographical studies, could be more precisely differentiated with the additional evidence from identification of their natural dyes and metals along with information of weaving techniques. Dyes and metal of the metal-wrapped threads from fifteen Persian velvets and six Indian velvets were analyzed by high performance liquid chromatography with photo diode array detector and by scanning electron microscopy with energy dispersive X-ray spectrometry respectively. Results: There seem to be types of dyes which specifically characterize the velvets of each culture, as well as types of dyes commonly found in velvets of both cultures. Dyes typical of Persian velvets are cochineal and yellow larkspur, while lac and turmeric are characteristic of Indian velvets. The dyes commonly found are a combination of yellow larkspur and indigo dye in green, as well as safflower, indigo dye, soluble redwoods, and tannin dye. There were exceptions however. Because of those exceptions, examining the range of dyes used in the velvets would be important in differentiating the velvets. Metal used for wrapping the threads was in all cases found to be silver of fairly high purity, the majority of which had been gilded. The silver from Persia metal threads showed very slightly higher copper content, while Indian threads showed nearly pure silver. This is the first extensive comparative study of dyes and metal threads of Safavid and Mughal velvets: the first evidence of yellow larkspur being the most used yellow dye in Persia, and of the possible differences in the two cultures' metal threads.
“…A digital microscope was used to enhance and register the selected details. Stereomicroscopy and SEM are the most commonly used analytical techniques for the study of metal threads (Indictor et al, 1989; Kohara et al, 1998; Nord et al, 2000; Hacke et al, 2003; Muros et al, 2007; Karatzni, 2008; Rezić et al, 2010). The threads sampled from the cope were studied with a stereomicroscope to determine morphological aspects, including the twist of the metal strip and the weft and warp fibers, in order to evaluate the color of different fibers used in the weaving and embroidery of the core silk yarns, the thread diameter, and the number of coils per millimeter of metal thread.…”
A 16th century liturgical cope belonging to D. Teotónio of Braganza (collection of the Museum of Évora, ME 172/1) was selected for a material study. The cope is made of a variety of materials that include two different types of metal threads, dyed silk yarns, and vegetable yarns used in the weft. Several samples from different points representing the different metal thread types and colored silk yarns were collected. Stereomicroscopy (optical microscopy) and scanning electron microscopy were used for morphological analysis of the textile fibers and evaluation of metal thread degradation products. Evaluation of mordants and metal thread composition was carried out by energy-dispersive X-ray spectroscopy. Liquid chromatography with diode array and mass spectrometry detection was used for dye identification, which allowed the determination of three different red dye sources and one yellow dye source in the colored silk yarns. Although different fabrics were used in the manufacturing of the cope, similarities identified in the characterization of the materials suggest that a single workshop was involved in its making.
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