Nanodiamond as a vector for siRNA delivery to Ewing sarcoma cells

The ability of diamond nanoparticles (nanodiamonds, NDs) to deliver small interfering RNA (siRNA) into Ewing sarcoma cells is investigated with a view to the possibility of in-vivo anticancer nucleic-acid drug delivery. siRNA is adsorbed onto NDs that are coated with cationic polymer. Cell uptake of NDs is demonstrated by taking advantage of the NDs' intrinsic fluorescence from embedded color-center defects. Cell toxicity of these coated NDs is shown to be low. Consistent with the internalization efficacy, a specific inhibition of EWS/Fli-1 gene expression is shown at the mRNA and protein level by the ND-vectorized siRNA in a serum-containing medium.     

From selective dissolution to crystal chemistry of brownmillerite in sulfate resisting cement

The aim of this study is to extract brownmillerite from sulfate resisting Portland cement (SRPC) in order to determine its crystal chemistry and the effects of dissolution protocols. Brownmillerites (C₄AF) from four SRPC were extracted and systematically studied by X-ray diffraction (XRD), electron probe microanalysis (EPMA), and X-ray fluorescence spectroscopy. Two extraction steps were used. The first is the salicylic acid/methanol (SAM) protocol that leaves a residue rich in ferrite, C₃A and sulfates. Precipitated hydrated sulfate minerals are also observed for clinker with high molar SO₃/Na₂O_eq ratio. The second, developed in this paper, uses acetic acid (AcA) extraction to dissolve C₃A and sulfates. The Rietveld refinements showed that all brownmillerites of this study crystallize in Ibm2 space group. Two families of brownmillerite were identified by their aluminum content and cell parameters, related to the presence of C₃A in the clinker. EPMA indicated that ferrites from SR0 and SR3 cements have Al/Fe ratios about 0.7 and 0.8–1.0, respectively. XRD allows to predict the (Al+Mg+Si)/Fe ratio in brownmillerite in good agreement with EPMA. The SAM protocol is the best way to study crystal chemistry of brownmillerite and the AcA protocol is recommended to dissolve sulfates and C₃A for further reactivity studies.     

Uncovering Buried Structure and Interfaces in Molecular Photovoltaics

The processes that generate current in organic photovoltaics are highly dependent on the micro‐ and nano‐structure in the semiconductor layers, especially at the donor‐acceptor interface. Elucidating film properties throughout the thickness of the devices is therefore key to their further development. Here, a methodology is developed to gain unprecedented insights into the structure and composition of the molecular layers within the depth of device structure using high resolution transmission electron microscopy (HRTEM). The technique was applied to three archetypical solar cell configurations consisting of copper phthalocyanine (CuPc) and C₆₀, which have been cross‐sectioned using a focused ion beam method optimized to minimize sample damage. The HRTEM images exhibit lattice fringes in both CuPc and C₆₀, confirming the crystallinity and texture of both materials, and offering novel insight into the growth of C₆₀ onto molecular materials. The donor‐acceptor interface morphology is further studied using scanning transmission electron microscopy (STEM) in combination with energy dispersive X‐ray (EDX) spectroscopy, extending the scope of our methodology to amorphous heterostructures.     

Effect of organic complexation on copper accumulation and toxicity to the estuarine red macroalga Ceramium tenuicorne: a test of the free ion activity model

Current water quality criteria (WQC) regulations on copper toxicity to biota are still based on total dissolved (<0.4 μm membrane filter) copper concentrations with a hardness modification for freshwaters. There are however ongoing efforts to incorporate metal speciation in WQC and toxicity regulations (such as the biotic ligand model-BLM) for copper and other metals. Here, we show that copper accumulation and growth inhibition of the Baltic macroalga Ceramium tenuicorne exposed to copper in artificial seawater at typical coastal and estuarine DOC concentrations (similar to 2-4 mg/L-C as fulvic acid) are better correlated to weakly complexed and total dissolved copper concentrations rather than the free copper concentration [Cu2+]. Our results using a combination of competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV) measurements and model calculations (using visual MINTEQ incorporating the Stockholm Humic Model) show that copper accumulation in C. tenuicorne only correlates linearly well to [Cu2+] at relatively high [Cu2+] and in the absence of fulvic acid. Thus the FIAM fails to describe copper accumulation in C. tenuicorne at copper and DOC concentrations typical of most marine waters. These results seem to indicate that at ambient total dissolved copper concentration in coastal and estuarine waters, C. tenuicorne might be able to access a sizable fraction of organically complexed copper when free copper concentration to the cell membrane is diffusion limited.     

Towards co-design with users who have autism spectrum disorders

People with cognitive disorders, such as autism or Asperger’s syndrome, face many barriers when being involved in the co-design of information and communications technologies (ICT). Cognitive disorders may require that co-design techniques be modified to fit with individual abilities. Up until recently, with technology design, purpose and use being in the hands of ‘experts’ there was little opportunity for customisation. However, ICT bring together various threads that make open many new possibilities. Not only are technologies cheaper, more powerful and more available than ever, but now parents, support agencies and people with autism spectrum disorders expect information technologies to be part of their worlds, and they have the capacity to participate in co-design for customisation. However, co-design techniques have not evolved to the extent that they capture this potential democratisation of the ICT. This paper reports on an investigation of the potential to develop a set of guidelines for co-design techniques to enable people with autism spectrum disorders to participate in ICT design.     

Pd20Pt20Cu20Ni20P20 高熵金属玻璃的热稳定性和热塑成形性

采用差示扫描量热法、X射线衍射和热力学分析研究了Pd₂₀Pt₂₀Cu₂₀Ni₂₀P₂₀高熵金属玻璃（HEMG）的热稳定性和热力学性能。结果表明,与其他经典贵金属基金属玻璃相比,Pd₂₀Pt₂₀Cu₂₀Ni₂₀P₂₀ HEMG具有相当的性能和鲜明的特点。     

Distributed Poisson Surface Reconstruction

Screened Poisson surface reconstruction robustly creates meshes from oriented point sets. For large datasets, the technique requires hours of computation and significant memory. We present a method to parallelize and distribute this computation over multiple commodity client nodes. The method partitions space on one axis into adaptively sized slabs containing balanced subsets of points. Because the Poisson formulation involves a global system, the challenge is to maintain seamless consistency at the slab boundaries and obtain a reconstruction that is indistinguishable from the serial result. To this end, we express the reconstructed indicator function as a sum of a low-resolution term computed on a server and high-resolution terms computed on distributed clients. Using a client–server architecture, we map the computation onto a sequence of serial server tasks and parallel client tasks, separated by synchronization barriers. This architecture also enables low-memory evaluation on a single computer, albeit without speedup. We demonstrate a 700 million vertex reconstruction of the billion point David statue scan in less than 20 min on a 65-node cluster with a maximum memory usage of 45 GB/node, or in 14 h on a single node.