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Biomaterials 2008;29:3393-3401). Crystallisation during biodegradation was not considered in the previous work which is the topic of the current paper. For many commonly used biodegradable polymers, there is a strong interplay between crystallisation and hydrolysis reaction during biodegradation -the chain cleavage caused by the hydrolysis reaction provides an extra mobility for the polymer chains to crystallise and the resulting crystalline phase becomes more resistant to further hydrolysis reaction. This paper presents a complete theory to describe this interplay.The fundamental equations in the Avrami's theory for crystallisation are modified and coupled to the diffusion-reaction equations that were developed in our previous work.The mathematical equations are then applied to three biodegradable polymers for which long term degradation data are available in the literature. It is shown that the model can capture the behaviour of the major biodegradable polymers very well.

 Gyroid scaffold has superior mechanical properties to mimic human bone;  Gyroid scaffold has adjustable permeability properties to match human bone;  SLM-produced gyroid scaffold has good consistency with its designing CAD model.

A novel silica coated paper substrate is developed through a facile vacuum filtration method by using the commercially available silica particles as the coating material and corn starch as the adhesive agent. Unlike the commercial silica coated paper (namely grade SG81 paper), the resulting paper substrate was covered by a layer of silica particles on the top side of the paper, and no cellulosic fibers were exposed at its surface. After loading a solution sample on its surface, the coated silica particles allowed the target analytes to remain at the top side rather than penetration through the substrate. Owing to this effect and the special interactions with analytes, the as-prepared silica coated paper demonstrated superior performance in the analysis of different pesticides in milk using paper spray mass spectrometry to the uncoated filter paper and grade SG81 paper. Compared to the other two papers, paper spray analysis using the as-prepared paper improved the estimated lower limit of quantitation of seven pesticides (alachlor, acetochlor, pretilachlor, butachlor, metolachlor, napropamid and benzeneacetamide) in milk by a factor of 2 to 19-fold depending on the pesticide. This study offers a novel paper substrate for paper spray in high sensitivity analysis of target analytes in a complex foodstuff matrix without any pretreatment.

Since the discovery of graphene, there has been an ever-increasing interest in two-dimensional (2D) layered materials with exceptional properties. To this end, a variety of synthesis methods have been developed. However, it is still challenging to produce large-scale high-quality single-crystalline 2D materials. In this regard, atomic layer deposition (ALD) has recently shown great promise and has stimulated more and more research efforts, ascribed to its unique growth mechanism and distinguished capabilities to achieve nanoscale films with excellent uniformity, unrivaled conformality, and atomic-scale controllability. This review comprehensively summarizes recent progress on ALD for 2D atomic sheets, including 25 different materials and more than 80 ALD processes. This work highlights different technical routes to ALD, their precise controllability, and their underlying principles for 2D materials. It is expected that this work will help boost more research efforts for controllable growth of high-quality 2D materials via ALD.

Paper spray mass spectrometry has been demonstrated to be promising for direct analysis of therapeutic drugs in dried blood spots (DBS); however, the strong hydrogen bond and van de Waals interactions between paper substrate and analytes containing polar functional groups (e.g., therapeutic drugs) affect greatly the elution behavior and analysis sensitivity of compounds of interest during paper spray. Herein, we developed a one-sided ZrO2 coated paper substrate through a facile vacuum filtration approach using commercial ZrO2 particles as coating material and soluble starch as adhesive agent. Owing to the unique surface properties, as-prepared ZrO2 paper substrate has been shown to have excellent performance for analysis of therapeutic drugs in DBS during paper spray mass spectrometry. In contrast to original cellulose paper substrates, improvements of 43-189-fold in lower limit of quantitation (LLOQ) were obtained for the tested drugs using ZrO2 coated paper for paper spray. In comparing with the previously reported grade SG81 paper and one-sided silica coated paper, the LLOQs of the tested drugs with as-prepared ZrO2 paper decreased 1.5-16.5-fold relative to those from the above two, revealing that ZrO2 coated paper is a good candidate for paper spray in high sensitivity analysis of therapeutic drugs in DBS.

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