222 research outputs found

    Equivalent stiffness and dynamic response of new mechanical elastic wheel

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    To investigate the stiffness characteristics of the new mechanical elastic wheel (MEW), the elastic foundation closed circle curved beam model of MEW was established by curved beam theory. With the Laplace transformation and boundary conditions of the governing differential equations, the analytical relations among the radial deformation, bending stiffness of elastic wheel, the elastic foundation stiffness of hinges, elastic wheel laminated structure parameters and excitation frequency were analyzed. The correctness of the curved beam model was validated by the finite element method. Curved beam model validation and the application of the nonlinear finite element model show that the influence of elastic wheel laminated structure and deformation on dynamic response is equal to the equivalent stiffness. The results indicate that the equivalent stiffness and dynamic response of MEW become increased nonlinearly with component content of elastic bead ring, moreover, the equivalent stiffness and dynamic response of MEW increase nonlinearly with the deformation amount of MEW, and the dynamic response significantly decreases with the increase of excitation frequency, under this circumstance that the laminated structure of elastic wheel has been unchanged

    Knowledge mapping concerning applications of nanocomposite hydrogels for drug delivery: A bibliometric and visualized study (2003ā€“2022)

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    Background: Nanocomposite Hydrogels (NHs) are 3D molecular networks formed by physically or covalently crosslinking polymer with nanoparticles or nanostructures, which are particularly suitable for serving as carriers for drug delivery systems. Many articles pertaining to the applications of Nanocomposite Hydrogels for drug delivery have been published, however, the use of bibliometric and visualized analysis in this area remains unstudied. The purpose of this bibliometric study intended to comprehensively analyze the knowledge domain, research hotspots and frontiers associated with the applications of Nanocomposite Hydrogels for drug delivery.Methods: We identified and retrieved the publications concerning the applications of NHs for drug delivery between 2003 and 2022 from Web of Science Core Collection Bibliometric and visualized analysis was utilized in this investigative study.Results: 631 articles meeting the inclusion criteria were identified and retrieved from WoSCC. Among those, 2,233 authors worldwide contributed in the studies, accompanied by an average annual article increase of 24.67%. The articles were co-authored by 764 institutions from 52 countries/regions, and China published the most, followed by Iran and the United States. Five institutions published more than 40 papers, namely Univ Tabriz (n = 79), Tabriz Univ Med Sci (n = 70), Islamic Azad Univ (n = 49), Payame Noor Univ (n = 42) and Texas A&M Univ (n = 41). The articles were published in 198 journals, among which the International Journal of Biological Macromolecules (n = 53) published the most articles, followed by Carbohydrate Polymers (n = 24) and ACS Applied Materials and Interfaces (n = 22). The top three journals most locally cited were Carbohydrate Polymers, Biomaterials and Advanced materials. The most productive author was Namazi H (29 articles), followed by Bardajee G (15 articles) and Zhang J (11 articles) and the researchers who worked closely with other ones usually published more papers. ā€œDoxorubicin,ā€ ā€œantibacterialā€ and ā€œresponsive hydrogelsā€ represent the current research hotspots in this field and ā€œcancer therapyā€ was a rising research topic in recent years. ā€œ(cancer) therapeuticsā€ and ā€œbioadhesiveā€ represent the current research frontiers.Conclusion: This bibliometric and visualized analysis offered an investigative study and comprehensive understanding of publications regarding the applications of Nanocomposite Hydrogels for drug delivery from 2003 to 2022. The outcome of this study would provide insights for researchers in the field of Nanocomposite Hydrogels applications for drug delivery

    Recent Progress on Nanostructures for Drug Delivery Applications

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    With the rapid development of nanotechnology, the convergence of nanostructures and drug delivery has become a research hotspot in recent years. Due to their unique and superior properties, various nanostructures, especially those fabricated from self-assembly, are able to significantly increase the solubility of poorly soluble drugs, reduce cytotoxicity toward normal tissues, and improve therapeutic efficacy. Nanostructures have been successfully applied in the delivery of diverse drugs, such as small molecules, peptides, proteins, and nucleic acids. In this paper, the driving forces for the self-assembly of nanostructures are introduced. The strategies of drug delivery by nanostructures are briefly discussed. Furthermore, the emphasis is put on a variety of nanostructures fabricated from various building materials, mainly liposomes, polymers, ceramics, metal, peptides, nucleic acids, and even drugs themselves

    Recent Progress on Nanostructures for Drug Delivery Applications

    Get PDF
    With the rapid development of nanotechnology, the convergence of nanostructures and drug delivery has become a research hotspot in recent years. Due to their unique and superior properties, various nanostructures, especially those fabricated from self-assembly, are able to significantly increase the solubility of poorly soluble drugs, reduce cytotoxicity toward normal tissues, and improve therapeutic efficacy. Nanostructures have been successfully applied in the delivery of diverse drugs, such as small molecules, peptides, proteins, and nucleic acids. In this paper, the driving forces for the self-assembly of nanostructures are introduced. The strategies of drug delivery by nanostructures are briefly discussed. Furthermore, the emphasis is put on a variety of nanostructures fabricated from various building materials, mainly liposomes, polymers, ceramics, metal, peptides, nucleic acids, and even drugs themselves

    New Polysaccharide Compounds Derived from Submerged Culture of Ganoderma lucidum and Lycium barbarum

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    Biljka Lycium barbarum i gljiva Ganoderma lucidum sve se viÅ”e istražuju u Kini zbog njihove antitumorske aktivnosti, pri čemu se drži da su polisaharidi njihovi najvažniji funkcionalni sastojci. U ovom je radu istražen postupak dobivanja novih polisaharida, izoliranih iz suÅ”enih plodova L. barbarum i dobivenih submerznim uzgojem G. lucidum. Podaci pokazuju da novodobiveni fermentirani polisaharidi i smjesa polisaharida u odgovarajućim omjerima i koncentracijama imaju veću sposobnost uklanjanja slobodnih radikala od izvornih polisaharida, te da sadrže slične frakcije. Zaključeno je da novi polisaharidi imaju veću bioaktivnost, a mogu se lakÅ”e dobiti fermentacijom.Lycium barbarum and Ganoderma lucidum, highly valued Chinese medicinal fruit and mushroom, have attracted more and more attention because of the antitumour activities they have shown, and polysaccharides are considered their most important functional constituent. Forming new compounds of L. barbarum polysaccharides, isolated from dried L. barbarum fruits, and G. lucidum polysaccharides, derived from a submerged culture of G. lucidum, has been investigated in this paper. Our data illustrate that two polysaccharide compounds, fermented polysaccharides and mixed polysaccharides, at the appropriate ratio and concentration have stronger free radical scavenging ability than the single polysaccharide. Ion exchange chromatography and high-performance liquid chromatography (HPLC) analyses indicated that the components of the new polysaccharide compounds had changed compared to those of the single polysaccharide. In addition, similar fractions were shared with the two polysaccharide compounds. Hence, the findings demonstrate that these new polysaccharide compounds might have stronger bioactivity than a single polysaccharide and could be obtained more easily by fermentation

    Research on vibration characteristics and its key influencing factors of new mechanical elastic wheel

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    This paper presents the vibration characteristics and its key influencing factors of a new mechanical elastic wheel (MEW). The MEW was modeled as a ring on elastic foundations (REF) with distributed spring stiffness in the radial and tangential directions. The general forced solutions of inextensible vibration were derived by the use of a modal expansion technique and Arnoldi method, and the accuracy of the solutions had been validated by FEM simulation and modal test under free suspension and various loading situations. The natural frequencies and mode shapes of the rotating MEW could be obtained under free suspension and various loading situations. Moreover, the effects of various rotational speed, loading and different number of hinges on natural frequencies were investigated. Finally, the effect of different number of hinges on the damping ratio of the MEW radial modes was also analyzed. The analysis results reflect the objective law of the actual vibration characteristics of the MEW, and provide a reference for the MEW structure optimization and the vibration characteristics of the whole vehicle

    New Polysaccharide Compounds Derived from Submerged Culture of Ganoderma lucidum and Lycium barbarum

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    Biljka Lycium barbarum i gljiva Ganoderma lucidum sve se viÅ”e istražuju u Kini zbog njihove antitumorske aktivnosti, pri čemu se drži da su polisaharidi njihovi najvažniji funkcionalni sastojci. U ovom je radu istražen postupak dobivanja novih polisaharida, izoliranih iz suÅ”enih plodova L. barbarum i dobivenih submerznim uzgojem G. lucidum. Podaci pokazuju da novodobiveni fermentirani polisaharidi i smjesa polisaharida u odgovarajućim omjerima i koncentracijama imaju veću sposobnost uklanjanja slobodnih radikala od izvornih polisaharida, te da sadrže slične frakcije. Zaključeno je da novi polisaharidi imaju veću bioaktivnost, a mogu se lakÅ”e dobiti fermentacijom.Lycium barbarum and Ganoderma lucidum, highly valued Chinese medicinal fruit and mushroom, have attracted more and more attention because of the antitumour activities they have shown, and polysaccharides are considered their most important functional constituent. Forming new compounds of L. barbarum polysaccharides, isolated from dried L. barbarum fruits, and G. lucidum polysaccharides, derived from a submerged culture of G. lucidum, has been investigated in this paper. Our data illustrate that two polysaccharide compounds, fermented polysaccharides and mixed polysaccharides, at the appropriate ratio and concentration have stronger free radical scavenging ability than the single polysaccharide. Ion exchange chromatography and high-performance liquid chromatography (HPLC) analyses indicated that the components of the new polysaccharide compounds had changed compared to those of the single polysaccharide. In addition, similar fractions were shared with the two polysaccharide compounds. Hence, the findings demonstrate that these new polysaccharide compounds might have stronger bioactivity than a single polysaccharide and could be obtained more easily by fermentation

    Equivalent stiffness and dynamic response of new mechanical elastic wheel

    Get PDF
    To investigate the stiffness characteristics of the new mechanical elastic wheel (MEW), the elastic foundation closed circle curved beam model of MEW was established by curved beam theory. With the Laplace transformation and boundary conditions of the governing differential equations, the analytical relations among the radial deformation, bending stiffness of elastic wheel, the elastic foundation stiffness of hinges, elastic wheel laminated structure parameters and excitation frequency were analyzed. The correctness of the curved beam model was validated by the finite element method. Curved beam model validation and the application of the nonlinear finite element model show that the influence of elastic wheel laminated structure and deformation on dynamic response is equal to the equivalent stiffness. The results indicate that the equivalent stiffness and dynamic response of MEW become increased nonlinearly with component content of elastic bead ring, moreover, the equivalent stiffness and dynamic response of MEW increase nonlinearly with the deformation amount of MEW, and the dynamic response significantly decreases with the increase of excitation frequency, under this circumstance that the laminated structure of elastic wheel has been unchanged

    Heparan sulfate is the attachment factor associated with channel catfish virus infection on host cells

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    Channel catfish virus (CCV; family Alloherpesviridae) infects channel catfish, causing great harm to aquaculture fisheries and economic development. Attachment is the first step in viral infection and relies on the interaction of virions with components of the extracellular matrix (ECM). The present study aimed to explored the role of the main three ECM components in CCV attachment. Western blotting and quantitative real-time PCR analysis showed that neither collagen nor hyaluronic acid treatments had significant effects on CCV attachment. When exogenous heparin was used as a competitive inhibitor, the adhesion of heparin sodium salt to CCV was dose-dependent. When the concentration of heparin sodium salt was 10 mg/mL, the inhibitory effect on CCV infection of channel catfish ovary (CCO/BB) cells was more than 90%. Heparinase I could significantly prevent CCV attachment by digesting heparan sulfate on the cell surface, and both heparin sodium salt and heparinase I could dose-dependently reduce CCV titers, suggesting that heparin plays an important role in CCV attachment. In addition, the binding experiments between heparin-agarose beads and virions showed that CCV virions could specifically bind to heparin in a dose-dependent manner. The above results suggested that heparan sulfate might be an attachment factor involved in CCV infection of CCO/BB cells. These results increase our understand of the attachment mechanism of CCV and lay the foundation for further research on antiviral drugs
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