Tailored monoclonal antibody as recognition probe of immunosensor for ultrasensitive detection of silk fibroin and use in the study of archaeological samples.

The ultrasensitive detection of fibroin in unearthed silk relics has great significance for investigating the origin and transmission of silk. In this study, an anti-fibroin monoclonal antibody was successfully prepared through animal immunization. Next, a label-free electrochemical immunosensor was fabricated using layer-by-layer self-assembly technology, and an indirect enzyme-linked immunosorbent assay (ELISA) was proposed. The two methods exhibited excellent sensitivity and specificity in the detection of silk fibroin, while the immunosensor showed a wider quantitative detection range (0.1-100 ng mL-1) and a lower detection limit (0.051 ng mL-1) than ELISA (10-100 ng mL-1 and 8.71 ng mL-1). Furthermore, the performance of the immunosensor was superior in archaeological sample detection. Taking advantage of the well-prepared monoclonal antibody, the two proposed immunological assays demonstrate tremendous potential for the ultrasensitive detection of silk fibroin, which can make great contributions to exploring the origin and transmission routes of ancient silks.

Buyid Silk and the Tale of Bibi Shahrbanu: Identification of Biomarkers of Artificial Aging (Forgery) of Silk.

Buyid silk forgery is one of the most famous silk forgeries in the world. In 1924-1925, excavation of the Bibi Shahrbanu site in Iran unearthed several silk textiles. The silks were thought to be of the Buyid period (934-1062 BCE) of the Persian Empire and have since been known as the "Buyid silks". In the 1930s, more silk appeared and was reported as being from the Buyid period as well. Controversy over the authenticity of these silks escalated after the purchase of the silks by museums throughout the world. Extensive investigations of several of these silks have been conducted over the years with respect to iconography, weaving patterns, dyes/mordant, style, and even radiocarbon dating. It was found that most of the silks are not from Buyid period. To test the authenticity of these silk fabrics, the recently developed silk dating technique using amino acid racemization (AAR) in conjunction with capillary electrophoresis mass spectrometry was applied to 13 Buyid silk specimens from the Textile Museum collections. Among these silk specimens, the AAR ratios of only one specimen were consistent with authentic silk fabrics collected from various museums. In addition, the aspartic acid racemization ratio of this specimen was also consistent with its 14C dating. The other "Buyid silks" showed excessive levels of amino acid racemization not only for aspartic acid, but also for phenylalanine and tyrosine, inconsistent with racemization rates of these amino acids in authentic historical silk fabrics. Treatment of modern silk with a base at different pH and temperature reproduced the AAR pattern of the Buyid silks, implying that chemical treatment with a base at relatively high temperatures was perhaps the method used to artificially age these fabrics. The results imply that the racemization ratios of aspartic acid, phenylalanine, and tyrosine can be used as biomarkers for identification of naturally versus artificially aged silk.

Nomadic ecology shaped the highland geography of Asia's Silk Roads.

There are many unanswered questions about the evolution of the ancient 'Silk Roads' across Asia. This is especially the case in their mountainous stretches, where harsh terrain is seen as an impediment to travel. Considering the ecology and mobility of inner Asian mountain pastoralists, we use 'flow accumulation' modelling to calculate the annual routes of nomadic societies (from 750 m to 4,000 m elevation). Aggregating 500 iterations of the model reveals a high-resolution flow network that simulates how centuries of seasonal nomadic herding could shape discrete routes of connectivity across the mountains of Asia. We then compare the locations of known high-elevation Silk Road sites with the geography of these optimized herding flows, and find a significant correspondence in mountainous regions. Thus, we argue that highland Silk Road networks (from 750 m to 4,000 m) emerged slowly in relation to long-established mobility patterns of nomadic herders in the mountains of inner Asia.

Biomolecular Evidence of Silk from 8,500 Years Ago.

Pottery, bone implements, and stone tools are routinely found at Neolithic sites. However, the integrity of textiles or silk is susceptible to degradation, and it is therefore very difficult for such materials to be preserved for 8,000 years. Although previous studies have provided important evidence of the emergence of weaving skills and tools, such as figuline spinning wheels and osseous lamellas with traces of filament winding, there is a lack of direct evidence proving the existence of silk. In this paper, we explored evidence of prehistoric silk fibroin through the analysis of soil samples collected from three tombs at the Neolithic site of Jiahu. Mass spectrometry was employed and integrated with proteomics to characterize the key peptides of silk fibroin. The direct biomolecular evidence reported here showed the existence of prehistoric silk fibroin, which was found in 8,500-year-old tombs. Rough weaving tools and bone needles were also excavated, indicating the possibility that the Jiahu residents may possess the basic weaving and sewing skills in making textile. This finding may advance the study of the history of silk, and the civilization of the Neolithic Age.

Alexandria, An emporium in the Silk Road, and the Traffic of Unusual Medicines.

In Ancient times, an active trade of exotic and peculiar drugs tool place along the Silk Road. Coming through China, India, Central Asia, Armenia, including Colchis, Arabia, Nubia as far as Greece and Rome, it was centered during Ptolemaic and Roman times in Alexandria, the world Emporium, remarkably advanced in scientific medicine. Physicians required a variety of active ingredients for their pharmacotherapy, following various related branches of medicine. These included: 1) herbal remedies: including toxic plants 2) polypharmacy: missing together all kind of drugs 3) dreckapotheke or copropharmacy, employing unclean materials 4) organic therapy, using exotic or domestic animal products 5) aromatherapy, lined to essential oils and perfumes 6) 'medical astrology and botany', regarding the laws of sympathy in the natural world 7) alchemy and magic medicine: with occult knowledge

"The Great Silk Road" and the First Description of Hypoxia.

The first written reports about the effect of high-altitude air on the human organism in Ancient China (the 30s BC) and in South America during the conquest (late XVI century) are discussed in this paper.

Analytical markers for silk degradation: comparing historic silk and silk artificially aged in different environments.

Suitable analytical markers to assess the degree of degradation of historic silk textiles at molecular and macroscopic levels have been identified and compared with silk textiles aged artificially in different environments, namely (i) ultraviolet (UV) exposure, (ii) thermo-oxidation, (iii) controlled humidity and (iv) pH. The changes at the molecular level in the amino acid composition, the formation of oxidative moieties, crystallinity and molecular weight correlate well with the changes in the macroscopic properties such as brightness, pH and mechanical properties. These analytical markers are useful to understand the degradation mechanisms that silk textiles undergo under different degradation environments, involving oxidation processes, hydrolysis, chain scission and physical arrangements. Thermo-oxidation at high temperatures proves to be the accelerated ageing procedure producing silk samples that most resembled the degree of degradation of early seventeenth-century silk. These analytical markers will be valuable to support the textile conservation tasks currently being performed in museums to preserve our heritage.

Historical and archaeological textiles: an insight on degradation products of wool and silk yarns.

The characterisation of micro-samples from works of art and archaeological residues is a particularly complex task, due to the fact that only a relatively low amount of material is available for sampling, and compounds both derived from the target analytes and the matrix can be simultaneously present. Thus, sensitive, selective and reliable analytical procedures need to be developed. This paper presents the optimisation of an instrumental procedure based on liquid chromatography with mass spectrometric detection, which allows for determining selected analytes (anthraquinones, tannins, flavonoids), along with their known degradation products: phenolic acids. The instrumental parameters were optimised in terms of selecting the best ionisation source (APCI and ESI were compared), choosing the compound-dependant MS parameters and enhancing selectivity and sensitivity (SIM and MRM analyses were compared). The proposed procedure proved to be sensitive and selective, with limits of detection (0.4-20 ng/mL). The analytical procedure was validated by characterising reference materials, i.e. dyed and undyed woollen and silk yarns, both freshly prepared and artificially aged. Particularly, the study focused on the determination of 4-hydroxybenzoic acid, and on the correlation between its relative amounts with respect to ageing time. The optimised procedure was also applied to historical samples and proved fundamental in unravelling the complex composition of black dyed yarns collected from a medieval tapestry. The much degraded yarns were dyed with a tannin based dye, extracted from gallnuts, alder bark or sumac; the less degraded ones were coloured by superimposing colours with cochineal, madder, weld and indigo dye baths, and eventually by adding gallo-tannins as well.

[Research on the infrared spectrometry of aging silk fabrics].

The detection of deterioration degree of ancient silk fabrics will be helpful to the selection and developing of conservation methods. This paper carried out some research on the deterioration extent and mechanism of silk fabrics by means of infrared spectrometry. The samples artificially aged and excavated from Hubei, Innermongolia and Qinghai province, were analyzed. The artificially aging was done by simulating three main natural aging factors: light, heat and hydrolysis. The infrared spectrometric analysis results show that although the infrared spectrometry is a half-quantitative analysis method, for the hydrolysis-aged silk fabrics, it can give good qualitative and better half-quantitative analysis results because of the increase of carboxyl. So the infrared spectrometric analysis is of practical value for the conservation state and aging mechanism studies of ancient silk.