384 research outputs found

    Self-assembly of Zein-based microcarrier system for colon-targeted oral drug delivery

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    The advances in pharmaceutical technology allow for the development of various region-selective delivery systems for oral administration to optimize local and systemic therapy. In this paper, micronization associated with a polymorph modification approach was proposed for improving the solubility of hydrophobic drugs for developing a Zein-based colon-targeted delivery system. A microcarrier based on self-assembled structures of Zein was fabricated via a built-in ultrasonic dialysis process, which displayed high payload of a model drug, indomethacin (Indo), with its optimal crystal form. The possible self-assembly mechanism of Zein/Indo forming porous structure in the ultrasonic dialysis process was attributed to the results of intra- and/or intermolecular interactions between Zein and Indo. The designed microspheres, Zein-Indo@PDA, with a surface coating of polydopamine (PDA) not only rendered them enhanced stability and mechanical resistance but also hindered the premature drug release at undesired sites. This innovative formulation design may offer better chances of colon-targeted release

    When NTT Meets Karatsuba: Preprocess-then-NTT Technique Revisited

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    The Number Theoretic Transform (NTT) technique is widely used in the implementation of the cryptographic schemes based on the Ring Learning With Errors problem(RLWE), since it provides efficient algorithm for multiplication of polynomials over the finite field. However, to employ NTT, the finite field is required to have some special root of unity, such as nn-th root, which makes the module qq in RLWE big since we need q≡1mod  2nq\equiv 1\mod 2n to ensure such root exits. At Inscrypt 2018, Zhou et al. proposed a technique called preprocess-then-NTT to reduce the value of modulus qq while the NTT still works, and the time complexity is just a constant (>1>1) multiple of the original NTT algorithm asymptotically. In this paper, we revisit the preprocess-then-NTT technique and point out it can be improved such that its time complexity is as the same as the original NTT algorithm asymptotically. What\u27s more, through experiments we find that even compared with the original NTT our improved algorithm may have some advantages in efficiency

    Adaptive Hierarchical Origami Metastructures

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    Shape-morphing capabilities are crucial for enabling multifunctionality in both biological and artificial systems. Various strategies for shape morphing have been proposed for applications in metamaterials and robotics. However, few of these approaches have achieved the ability to seamlessly transform into a multitude of volumetric shapes post-fabrication using a relatively simple actuation and control mechanism. Taking inspiration from thick origami and hierarchies in nature, we present a new hierarchical construction method based on polyhedrons to create an extensive library of compact origami metastructures. We show that a single hierarchical origami structure can autonomously adapt to over 103 versatile architectural configurations, achieved with the utilization of fewer than 3 actuation degrees of freedom and employing simple transition kinematics. We uncover the fundamental principles governing theses shape transformation through theoretical models. Furthermore, we also demonstrate the wide-ranging potential applications of these transformable hierarchical structures. These include their uses as untethered and autonomous robotic transformers capable of various gait-shifting and multidirectional locomotion, as well as rapidly self-deployable and self-reconfigurable architecture, exemplifying its scalability up to the meter scale. Lastly, we introduce the concept of multitask reconfigurable and deployable space robots and habitats, showcasing the adaptability and versatility of these metastructures

    High sensitivity HI image of diffuse gas and new tidal features in M51 observed by FAST

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    We observed the classical interacting galaxy M51 with FAST and obtain high sensitivity HI image with column density down to 3.8 ×\times 1018^{18} cm−2^{-2}. In the image we can see a diffuse extended envelope around the system and several new tidal features. We also get a deeper look at M51b's probable gas, which has an approximated velocity range of 560 to 740 km s−1^{-1} and a flux of 7.5 Jy km s−1^{-1}. Compared to the VLA image, we observe more complete structures of the Southeast Tail, Northeast Cloud and Northwest Plume, as well as new features of the Northwest Cloud and Southwest Plume. M51's most prominent tidal feature, the Southeast Tail, looks very long and broad, in addition with two small detached clouds at the periphery. Due to the presence of optical and simulated counterparts, the Northwest cloud appears to be the tail of M51a, while the Northwest Plume is more likely a tidal tail of M51b. The large mass of the Northwest Plume suggests that M51b may have been as gas-rich as M51a before the interaction. In addition, the formation process of the Northeast Cloud and Southwest Plume is obscured by the lack of optical and simulated counterparts. These novel tidal features, together with M51b's probable gas, will inspire future simulations and provide a deeper understanding of the evolution of this interacting system.Comment: 11 pages, 9 figures, accepted for publication in MNRA

    Influence of Temperature on Hydrolysis Acidification of Food Waste

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    AbstractFor two-phase anaerobic digestion process of food waste, degree of hydrolysis and products by acidification during hydrolysis and acidification phase directly affect the performance of methanogenesis phase. Temperature has great impact on hydrolysis and acidification of food waste. This paper monitored the dynamic change of biogas production, biogas composition, pH, soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFAs) during hydrolysis and acidification stage so as to investigate specific influence of temperature on food waste. With the same inoculum and 9 days’ fermentation, three different temperatures (35, 55 and 70°C) were taken into consideration. The results showed that cumulative gas production was 4860mL at 70°C, which was 129.79% and 37.87% higher than that at 35 and 55°C. Besides, hydrogen content at 70°C was 45.34%, which was the highest among the three temperatures. Hydrolysis rate was proportional to the increase of temperature. Meanwhile, total VFAs yield and composition widely differed at three different temperatures. The hydrolysis and acidification products at 35°C were mainly ethanol and acetic acids and the highest concentrations of ethanol at 35°C were 3.28 and 3.65 times of that at 55 and 70°C, but more acetic, isobutyric and butyric acids were generated at 55 and 70°C. Among three temperatures, 70°C had the highest acetic acids concentration while 55°C had the highest isobutyric and butyric acids concentration
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