Site‐Specific Modification of Adeno‐Associated Viruses via a Genetically Engineered Aldehyde Tag

As a consequence of their well‐defined nanostructure and intrinsic bioactive functionality, virus‐based nanoparticles have shown promise for mediating gene delivery. Adeno‐associated virus (AAV) nanoparticles, which possess an excellent safety profile and therapeutic potential, hold potential for use in human gene therapy. However, because of their native tropisms, the applicability of AAV nanoparticles is often limited to restricted ranges of cells or tissues. Thus, retargeting AAV particles to the desired cell populations has continued to be a major research focus in many gene therapy applications. In this study, a general strategy is reported for nanoparticle targeting. This involves the site‐specific modification of AAV type 2 (AAV2) by genetically incorporating a short peptide, in this case an aldehyde tag, in the viral capsid. Such a tag can be exploited for site‐specific attachment of targeting molecules and allows for further introduction of targeting antibodies or ligands. It is shown that this modification neither affects the level of infectious viral titer nor intracellular trafficking properties. Furthermore, the site‐specific conjugation of targeting antibodies could significantly enhance viral transduction to those target cells that have otherwise exhibited very low permissiveness to AAV2 infection. This method also allows the functional incorporation of RGD peptides onto AAV2 for enhanced delivery with implications for cancer gene therapy.     

Economic‐statistical design of 2‐of‐2 and 2‐of‐3 runs rule scheme

In this paper, we investigate the economic‐statistical design method for the 2‐of‐2 runs rule and the 2‐of‐3 runs rule. The Markov chain approach is used to obtain the average run length and the process cycle time. In addition, a simplified algorithm is presented to search the optimal setting of the design parameters. A numerical example and sensitivity analysis are also provided to compare the performances of the runs rules. The results show that the use of runs rule scheme can reduce operating cost comparing with the Shewhart control chart while maintaining a good statistical performance. Copyright © 2008 John Wiley & Sons, Ltd.     

Flow‐induced vibrations of non‐linear cables. Part 2: Simulations

In this paper, we present simulations of flow interacting with non‐linear cables. We first consider the case of a pre‐stretched straight cable subject to uniform inflow, which eventually assumes a catenary‐like equilibrium position. We then simulate the flow induced by a riser of an S shape at equilibrium, subject to time‐periodic forcing at one of its ends. We demonstrate that the models and algorithms developed in Part 1 of this work can be used effectively in simulating flow‐structure interactions in non‐linear systems of industrial complexity. Copyright © 2002 John Wiley & Sons, Ltd.     

Edge‐Epitaxial Growth of 2D NbS2‐WS2 Lateral Metal‐Semiconductor Heterostructures

2D metal‐semiconductor heterostructures based on transition metal dichalcogenides (TMDs) are considered as intriguing building blocks for various fields, such as contact engineering and high‐frequency devices. Although, a series of p–n junctions utilizing semiconducting TMDs have been constructed hitherto, the realization of such a scheme using 2D metallic analogs has not been reported. Here, the synthesis of uniform monolayer metallic NbS₂ on sapphire substrate with domain size reaching to a millimeter scale via a facile chemical vapor deposition (CVD) route is demonstrated. More importantly, the epitaxial growth of NbS₂‐WS₂ lateral metal‐semiconductor heterostructures via a “two‐step” CVD method is realized. Both the lateral and vertical NbS₂‐WS₂ heterostructures are achieved here. Transmission electron microscopy studies reveal a clear chemical modulation with distinct interfaces. Raman and photoluminescence maps confirm the precisely controlled spatial modulation of the as‐grown NbS₂‐WS₂ heterostructures. The existence of the NbS₂‐WS₂ heterostructures is further manifested by electrical transport measurements. This work broadens the horizon of the in situ synthesis of TMD‐based heterostructures and enlightens the possibility of applications based on 2D metal‐semiconductor heterostructures.     

Plasma‐sprayed coatings in the system CaO‐TiO2‐ZrO2‐P2O5 for long‐term stable endoprostheses

Bioceramic materials based on CaTiZr₃(PO₄)₆ were synthesised by a ceramic route, characterised by XRD and EMPA analyses, and used as a precursor material to coat Ti6Al4V substrates by atmospheric plasma spraying. This led to multiphase bioactive layers with sufficient porosity for medical applications. In‐vitro biocompatibility tests conducted with primary cultures of rat bone marrow cells incubated for two weeks showed that the CaTiZr₃(PO₄)₆ substrates supported a distinctly higher cell growth rate compared with Thermanox™ cell cover slips used as a control.