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•Natural dyes were in situ identified using SERS method on fibers.•Ag nanoparticles SERS substrate was prepared by laser photoreduction.•Ag dendrites SERS substrate was prepared by ...galvanic displacement.•SERS substrates had characteristics of high sensitivity and reproducibility.•Different dye species were distinguished in one archaeological fiber.
Accurate detection of natural dyes in archaeological textiles is challenging due to limited sample availability. In situ detection of fibers by surface-enhanced Raman scattering (SERS) can overcome this challenge. In this study, we present two methods for the preparation of SERS substrates based on the laser photoreduction reaction and the galvanic displacement reaction, respectively. Our results show that the substrates prepared by these methods, including 450 nm-AgNPs, Cu-based Ag, and Zn-based Ag, offer several advantages such as rapid preparation, easy handling, low cost, high sensitivity and excellent reproducibility. Using these substrates, we successfully detected anthraquinones (alizarin, purpurin), indigoids (indigotin, indirubin), and protoberberine-type dyes in archaeological textiles from the Wei and Jin Dynasties. Notably, we were able to detect both indigo and protoberberine-type dyes in one archaeological fiber. The minimally invasive, in situ analytical approach developed provides a valuable tool for analytical applications where sampling is limited to microscopic amounts.
Textiles unearthed along the Silk Road are important material evidence of the spread and exchange of cultures in ancient Eurasia. This paper examines fibers and natural dyes in archaeological ...textiles from the Wei and Jin dynasties (220–420 CE) unearthed in Bazhou, a major route in the Xinjiang region of the ancient Silk Road. Optical microscope (OM), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and proteomics analysis were used to examine and compare ancient and modern fibers. The result showed that the ancient textile samples tested consisted of silk, wool and cotton. Two species of silk were accurately identified, Bombyx mori silk and Bombyx mandarina silk. In addition, dyes were extracted from textile artifacts using a mild extraction method and analyzed by high performance liquid chromatography coupled with a diode array detector and a mass spectrometry (HPLC-DAD-MS). As a result, the identified red dyes can be divided into plant dyes and insect dyes, such as Rubia cordifolia, Rubia tinctorum and Kermes vermilio. The yellow dyes identified were derived from plants such as Reseda luteola, Phellodendron chinense, Phellodendron amurense, Berberis spp. The blue dyes identified in these textiles indicate the presence of indigo. These dyes are not only local, but also many exotic dyes from central or eastern China, and even from the Mediterranean coast. This study reveals the diversity of fibers and natural dyes used in the historic Lop Nor area of Bazhou, providing insights into their species origination and distribution.
•Multi-analytical techniques were used for fiber identification in archaeological textiles from Bazhou, Xinjiang.•Bombyx mori silk and Bombyx mandarina silk were distinguished by proteomics analysis.•Plant and insect dyes were identified by HPLC-DAD-MS technique.•Exotic dyes from the Mediterranean coast were found in wool.•These fibers and dyes attest to the material spread of the Silk Road during the Wei and Jin dynasties.
Affective computing (AC) has been regarded as a relevant approach to identifying online learners’ mental states and predicting their learning performance. Previous research mainly used one ...single-source data set, typically learners’ facial expression, to compute learners’ affection. However, a single facial expression may represent different affections in various head poses. This study proposed a dual-source data approach to solve the problem. Facial expression and head pose are two typical data sources that can be captured from online learning videos. The current study collected a dual-source data set of facial expressions and head poses from an online learning class in a middle school. A deep learning neural network using AlexNet with an attention mechanism was developed to verify the syncretic effect on affective computing of the proposed dual-source fusion strategy. The results show that the dual-source fusion approach significantly outperforms the single-source approach based on the AC recognition accuracy between the two approaches (dual-source approach using Attention-AlexNet model 80.96%; single-source approach, facial expression 76.65% and head pose 64.34%). This study contributes to the theoretical construction of the dual-source data fusion approach, and the empirical validation of the effect of the Attention-AlexNet neural network approach on affective computing in online learning contexts.
MicroRNAs can regulate the transcription of protein‐coding genes associated with the development and progression of cancer. In this study, we explored the potential diagnostic function of exosome ...miR‐3184‐5p in gastric cancer. This exosome was isolated from the blood samples of 150 patients with gastric cancer and 60 healthy participants. The mean particle size and concentration of serum exosome in the patients with gastric cancer were 104.6 nm (93.97–115.84) and 6.21e+009 particles/ml (5.15e+009–7.12e+009), respectively. miR‐3184‐5p expression was substantially downregulated in the patients with gastric cancer compared with that in the healthy participants. The gastric cancer cell line HGC‐27 was cultured and transfected with the mimic and an inhibitor to overexpress and inhibit miR‐3184‐5p expression. miR‐3184‐5p strongly suppressed cell proliferation, migration, and invasion but induced cell apoptosis. Luciferase reporter assay revealed that XBP1 was the target of miR‐3184‐5p. miR‐3184‐5p substantially downregulated the expression of CD44, cyclin D1, MMP2, p65, p‐AKT, and p‐STAT3 but upregulated that of GRP78, IRE1, p‐JNK, and CHOP. Moreover, miR‐3184‐5p cleaved caspase‐12 and inhibited BCL‐2 expression. These results suggested that the downregulation of miR‐3184‐5p in patients with gastric cancer might regulate the AKT, STAT3, and IRE1 pathways to promote the vitality of gastric cancer cells.
Exosome miR‐3184‐5p regulates the proliferation, apoptosis and invasion of gastric cancer cell by targeting XBP‐1 and activating IRE1 signaling.
The light-induced deformation phenomenon observed in ternary thallium compounds can induce local deformation depending on the position of the light spot. This characteristic suggests that the optical ...constants can also be spatially controlled by changing the shape of the pump light. This study used an imaging Mueller matrix ellipsometer to investigate the relationship between the pump light spot shape and optical constant changes.
In this paper, an online theme-based collaborative learning model (OTBCL model) is proposed. Unlike the current approaches, the model takes into account the two aspects in learning: interpersonal ...socialization and mental internalization, and joins them with learning portfolios in learning activities of themes. Then, the architecture, user interfaces and learning portfolio module of OTBCL system are elaborately presented, some useful principles are summarized which guide the process of developing learning systems. Finally, a case study was introduced, which explains how to intuitively analyze the participation in group lifecycle with statistical diagrams automatically generated by the system.
Advances in distributed measurement of polarization characteristics for a Y waveguide using optical coherence domain polarimetry (OCDP) is reviewed in this paper. The polarization characteristics ...measurement and modeling methods for Y waveguide are introduced. The OCDP system errors induced by the optical delay line and birefringence dispersion are analyzed, and the relevant suppression techniques are provided. In the end, the dual-channel simultaneous measurement method used for evaluating the temperature-dependent polarization characteristics evaluation is also addressed.
How to optimize the high-value interaction between learners will become the next driver of efficient learning. Social network analysis provides meaningful and quantitative insights into the quality ...of knowledge construction process. This paper introduces why SNA can effectively assess the performance of knowledge building process. Then, five useful and efficient methods of assessment are presented in detail.
