942 research outputs found

    All-Digital Positron Emission Tomography Industry Ecology

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    The digital positron emission tomography (PET) innovation technology system, which gradually evolved from the Multi-Voltage Threshold (MVT) sampling method, has driven the development of many fields, including key materials, core devices, electronics, intelligent algorithms, and industry standards, forming a new PET industry ecology characterized by modular hardware and intelligent software. In 2010, the world's first All-Digital PET scientific instrument, based on the MVT method, was successfully developed and showed an obvious spatial resolution advantage. With the modular characteristics of the All-Digital PETā€™s detector, it has successively developed digital PET scientific instruments with different apertures, different fields of view (FOV), and different geometric structures for small animals, large animals, primates, and plants, and has been put into various scientific research applications. In 2015, the world's first All-Digital PET medical device prototype for human scanning was successfully developed. In the following 7 years, several clinical All-Digital PET products have been developed and put into the market. These All-Digital PET products break the fixed architecture of conventional whole body scanning in the past and use modular digital detectors to build various medical devices, such as site-dedicated PET systems, PET-insert system, wearable PET, and proton PET. It has helped promote the rapid expansion of PET applications from tumor diagnosis to new application fields such as nervous system diseases, unexplained fever, and proton precision treatment. The vigorous development of All-Digital PET ecology has also brought innovation to the industrial division of labor. The new scintillation crystal materials, the new silicon photomultiplier (SiPM), and the modular PET detector are developing independently and rapidly, forming their own standardized component or interface. The synchronous progress of upstream and downstream technologies has promoted the development of the entire PET industry chain and innovation chain. With the rapid development of All-Digital PET, the proposal of a variety of PET digital technology routes has also put forward new challenges to industry technical standards and regulatory systems, such as technical requirements for the digitization of PET medical devices and the registration guidelines that have been updated and developed simultaneously. This paper reviewed the dynamic progress of All-Digital PET in scientific instruments, medical devices, the industrial chain, and regulatory science in the past 20 years and looked forward to the future ecological development of All-Digital PET

    In vitro specific interactions revealed the infective characteristics of fungal endophytes to grapevine

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    In the present study a method for co-culture of fungal endophytic strains and grape cells was developed in order to study their interactions, and filter candidates for further safe inoculation in the vineyard. Analysis of morphological and physiological traits was performed by measuring the plant callus and fungal growth, plant cells viability, degree of cell oxidation and the scale of contact or its absence as reaction of the fungal endophyte to the presence of the plant callus. Accordingly, endophytic fungal strains (EFS) were classified on scale of invasion into categories (strong - medium - weak invasive), as well as the contact between the two partners (grow into - grow onto - contact - no contact) and the grape cell oxidation degree (normal (no oxidation) - light - moderate - serious). More included the dominance and distribution of EFS in the plant host, and correlation plots of physiological traits during plant callus and endophytic fungi coā€“culture were calculated

    Research progress on the relationship between axonal transport dysfunction in neuronal cells and Alzheimerā€™s disease

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    Alzheimerā€™s disease is known as one of the ā€œtop ten killers in the worldā€. Due to lack of effective therapy at presentļ¼Œ early pathological changes have captivated widespread attention. Axonal transport dysfunction has been reported as an early pathological feature of many neurodegenerative diseases. Howeverļ¼Œ multiple factors can cause axonal transport dysfunction. In this articleļ¼Œ the relationship between axonal transport dysfunction caused by kinesinsļ¼Œ microtubules and mitochondria and Alzheimerā€™s disease was discussedļ¼Œ aiming to provide new ideas for the prevention and treatment of Alzheimerā€™s disease by in-depth study on axonal transport mechanism of neure

    A programmable topological photonic chip

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    Controlling topological phases of light has allowed experimental observations of abundant topological phenomena and development of robust photonic devices. The prospect of more sophisticated controls with topological photonic devices for practical implementations requires high-level programmability. Here, we demonstrate a fully programmable topological photonic chip with large-scale integration of silicon photonic nanocircuits and microresonators. Photonic artificial atoms and their interactions in our compound system can be individually addressed and controlled, therefore allowing arbitrary altering of structural parameters and geometrical configurations for the observations of dynamic topological phase transitions and diverse photonic topological insulators. By individually programming artificial atoms on the generic chip, it has allowed comprehensive statistic characterisations of topological robustness against relatively weak disorders, as well as counterintuitive topological Anderson phase transitions induced by strong disorders. Our generic topological photonic chip that can be rapidly reprogrammed to implement multifunctionalities, prototypes a flexible and versatile platform for possible applications across fundamental science and topological technologies

    Experimental Quantum Teleportation of a Two-Qubit Composite System

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    Quantum teleportation, a way to transfer the state of a quantum system from one location to another, is central to quantum communication and plays an important role in a number of quantum computation protocols. Previous experimental demonstrations have been implemented with photonic or ionic qubits. Very recently long-distance teleportation and open-destination teleportation have also been realized. Until now, previous experiments have only been able to teleport single qubits. However, since teleportation of single qubits is insufficient for a large-scale realization of quantum communication and computation2-5, teleportation of a composite system containing two or more qubits has been seen as a long-standing goal in quantum information science. Here, we present the experimental realization of quantum teleportation of a two-qubit composite system. In the experiment, we develop and exploit a six-photon interferometer to teleport an arbitrary polarization state of two photons. The observed teleportation fidelities for different initial states are all well beyond the state estimation limit of 0.40 for a two-qubit system. Not only does our six-photon interferometer provide an important step towards teleportation of a complex system, it will also enable future experimental investigations on a number of fundamental quantum communication and computation protocols such as multi-stage realization of quantum-relay, fault-tolerant quantum computation, universal quantum error-correction and one-way quantum computation.Comment: 16pages, 4 figure

    Optimization of a static headspace GC-MS method and its application in metabolic fingerprinting of the leaf volatiles of 42 citrus cultivars

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    Citrus leaves, which are a rich source of plant volatiles, have the beneficial attributes of rapid growth, large biomass, and availability throughout the year. Establishing the leaf volatile profiles of different citrus genotypes would make a valuable contribution to citrus species identification and chemotaxonomic studies. In this study, we developed an efficient and convenient static headspace (HS) sampling technique combined with gas chromatography-mass spectrometry (GC-MS) analysis and optimized the extraction conditions (a 15-min incubation at 100 ĖšC without the addition of salt). Using a large set of 42 citrus cultivars, we validated the applicability of the optimized HS-GC-MS system in determining leaf volatile profiles. A total of 83 volatile metabolites, including monoterpene hydrocarbons, alcohols, sesquiterpene hydrocarbons, aldehydes, monoterpenoids, esters, and ketones were identified and quantified. Multivariate statistical analysis and hierarchical clustering revealed that mandarin (Citrus reticulata Blanco) and orange (Citrus sinensis L. Osbeck) groups exhibited notably differential volatile profiles, and that the mandarin group cultivars were characterized by the complex volatile profiles, thereby indicating the complex nature and diversity of these mandarin cultivars. We also identified those volatile compounds deemed to be the most useful in discriminating amongst citrus cultivars. This method developed in this study provides a rapid, simple, and reliable approach for the extraction and identification of citrus leaf volatile organic compound, and based on this methodology, we propose a leaf volatile profile-based classification model for citrus
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