Isolation of Stilbenoids and Lignans from Dendrobium hongdie

Purpose: To isolate and characterize chemical compounds of biological importance from the whole plant of Dendrobium hongdie.Methods: The whole plants of Dendrobium hongdie was extracted with ethanol (EtOH) and separated using silica gel, Sephadex LH-20 and MCI gel to isolate the pure compounds. Characterization of the isolated compounds was achieved using 1H and 13C nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS).Results: Nine compounds including two phenanthrenes, three bibenzyls, a phenanthraquinone, two lignans and a sterol were isolated from the extract. The structures of the compounds were elucidated as nudol (1), gigantol (2), batatasin III (3), tristin (4), moscatin (5), ephemeranthoquinone (6), (-)- syringaresinol (7), liriodendrin (8) and β-sitosterol (9).Conclusion: Nine compounds have been successfully isolated from D. hongdie for the first time. This plant is a potential source of some useful phytochemicals.Keywords: Dendrobium hongdie, Isolation, Stilbenoids, Lignans, Phytochemical

Adventitious shoot regeneration from in vitro stem explants of Phellodendron amurense

An efficient in vitro plant regeneration system from stem explants was established in Phellodendron amurense. Factors influencing shoot regeneration from stems including culture medium type, combinations of plant growth regulators and carbon source in the medium were investigated. Adventitious shoot regeneration was significantly influenced by the type of medium. Murashige and Skoog medium (MS) was the best for promoting shoot regeneration, followed by Gamborg medium (B5) and woody plant medium (WPM). The combination of 6-benzyladenine (BA) and naphthaleneacetic acid (NAA) produced better results for shoot regeneration. The optimum shoot regeneration frequency (74.5%) and number of shoots per explant (12.3) was achieved using MS medium supplemented with 29.7 M BA and 5.8 M NAA. High concentrations of BA and NAA in the medium inhibited shoot formation. Among the three sugars tested, 20 g dm-3 glucose was the optimum for shoot regeneration. Rooting of regenerated shoots was successful on 1/4-strength MS medium with the addition of 15.4 M IBA. Almost 100% plantlets survived acclimatization after transferred to soil.Key words: Phellodendron amurense, callus, shoot regeneration, stem explants

Factors affecting ventilation effectiveness in SARS wards

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High Fidelity Tape Transfer Printing Based On Chemically Induced Adhesive Strength Modulation

Transfer printing, a two-step process (i.e. picking up and printing) for heterogeneous integration, has been widely exploited for the fabrication of functional electronics system. To ensure a reliable process, strong adhesion for picking up and weak or no adhesion for printing are required. However, it is challenging to meet the requirements of switchable stamp adhesion. Here we introduce a simple, high fidelity process, namely tape transfer printing(TTP), enabled by chemically induced dramatic modulation in tape adhesive strength. We describe the working mechanism of the adhesion modulation that governs this process and demonstrate the method by high fidelity tape transfer printing several types of materials and devices, including Si pellets arrays, photodetector arrays, and electromyography (EMG) sensors, from their preparation substrates to various alien substrates. High fidelity tape transfer printing of components onto curvilinear surfaces is also illustrated

Arc Discharge Synthesis and Photoluminescence of 3D Feather-like AlN Nanostructures

A complex three-dimensional (3D) feather-like AlN nanostructure was synthesized by a direct reaction of high-purity Al granules with nitrogen using an arc discharge method. By adjusting the discharge time, a coral-like nanostructure, which evolved from the feather-like nanostructure, has also been observed. The novel 3D feather-like AlN nanostructure has a hierarchical dendritic structure, which means that the angle between the trunk stem and its branch is always about 30° in any part of the structure. The fine branches on the surface of the feather-like nanostructure have shown a uniform fish scale shape, which are about 100 nm long, 10 nm thick and several tens of nanometers in width. An alternate growth model has been proposed to explain the novel nanostructure. The spectrum of the feather-like products shows a strong blue emission band centered at 438 nm (2.84 eV), which indicates their potential application as blue light-emitting diodes

Exploring the diverse definitions of ‘evidence’: a scoping review

OBJECTIVES: To systematically collect and analyse diverse definitions of ‘evidence’ in both health and social sciences, and help users to correctly use the term ‘evidence’ and rethink what is the definition of ‘evidence’ in scientific research. DESIGN: Scoping review. METHODS: Definitions of evidence in the health sciences and social sciences were included. We have excluded the definition of evidence applied in the legal field, abstracts without full text, documents not published in either Chinese or English and so on. We established a multidisciplinary working group and systematically searched five electronic databases including Medline, Web of Science, EBSCO, the Chinese Social Sciences Citation Index and the Chinese Science Citation Database from their inception to 26 February 2022. We also searched websites and reviewed the reference lists of the identified studies. Six reviewers working in pairs, independently, selected studies according to the inclusion and exclusion criteria, and extracted information. Any differences were discussed in pairs, and if there was disagreement, it was resolved via discussion or with the help of a third reviewer. Reviewers extracted document characteristics, the original content for the definitions of ‘evidence’, assessed definitions as either intensional or extensional, and any citations for the given definition. RESULTS: Forty-nine documents were finally included after screening, and 68 definitions were obtained. After excluding duplicates, a total of 54 different definitions of ‘evidence’ were identified. There were 42 intensional definitions and 12 extensional definitions. The top three definiens were ‘information’, ‘fact’ and ‘research/study’. The definition of ‘evidence’ differed between health and social sciences. The term ‘research’ appeared most frequently in the definitions. CONCLUSIONS: The definition of ‘evidence’ has gradually attracted the attention of many scholars and decision-makers in health and social sciences. Nevertheless, there is no widely recognised and accepted definition in scientific research. Given the wide use of the term, we need to think about whether, or under what circumstances, a standardised, clear, meaningful and widely applicable definition of ‘evidence’ might be helpful

Polymorphisms of Glutathione S-transferases Omega-1 among ethnic populations in China

<p>Abstract</p> <p>Background</p> <p>Glutathione S-transferases (GSTs) is a genetic factor for many diseases and exhibits great diversities among various populations. We assessed association of the genotypes of Glutathione S-transferases Omega-1 (GSTO1) A140D with ethnicity in China.</p> <p>Results</p> <p>Peripheral blood samples were obtained from 1314 individuals from 14 ethnic groups. Polymorphisms of GSTO1 A140D were measured using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Logistic regression was employed to adjustment for regional factor. The frequency of GSTO1 140A allele was 15.49% in the total 14 ethnic populations. Compared to Han ethnic group, two ethnic populations were more likely to have AA or CA genotype [odds ratio (OR): 1.77, 95% confidence interval (95% CI): 1.05–2.98 for Uygur and OR: 1.78, 95% CI: 1.18–2.69 for Hui]. However, there were no statistically significant differences across 14 ethnic groups when region factor was adjusted. In Han ethnicity, region was significantly associated with AA or CA genotype. Han individuals who resided in North-west of China were more likely to have these genotypes than those in South of China (OR: 1.63, 95% CI: 1.21–2.20).</p> <p>Conclusion</p> <p>The prevalence of the GSTO1 140A varied significantly among different regional populations in China, which showed that geography played a more important role in the population differentiation for this allele than the ethnicity/race.</p

A practical and open source implementation of IEC 61850-7-2 for IED monitoring applications

A new open source mapping of IEC 61850-7-2 to web services has been defined and implemented. This work is useful for rapidly implementing user interfaces—particularly web-based interfaces—for monitoring and controlling Intelligent Electronic Devices (IEDs) from multiple vendors. The web service mapping has been implemented using the Hypertext Transfer Protocol (HTTP), with a message format in JavaScript Object Notation (JSON). This approach requires a simple and ubiquitous software stack for its implementation, which is a significant advantage over existing client-server communications mappings. The use of an open source paradigm allows for the rapid iteration and refinement of the design, implementation, and testing of the internal details of the proposed protocol stack, in a collaborative manner. These developments are of immediate interest to users of IEC 61850 and are particularly relevant to the IEC 61850 standardization process