Cucurbituril-based supramolecular engineered nanostructured materials

Cataloged from PDF version of article.Cucurbituril (CB) is a unique macrocycle with a rigid symmetrical structure, which is composed of two identical hydrophilic portals decorated with partially negatively charged carbonyl groups and a hydrophobic cavity. A number of different nanostructured materials, including nanoparticles, nanocomposites, vesicles and rods, have been prepared by taking advantage of the varying cavity size of the CB homologues, their ability to accommodate more than one guest in their cavities, their rigid symmetrical structures, as well as the water solubility of CB7. These nanostructures could find a wide range of potential applications in the areas of self-healing materials, nanomedicine, plasmonics, and nanocatalysis. Here, we review the recent progresses in the synthesis, properties and application of CB-based supramolecular engineered nanostructures, which are either constructed through CB-assisted self-assembly or from post-functionalized-CB homologues

Who Should Bear the Risk? A Theoretical and Behavioral Investigation of After-Sales Service Contracts

Since downtime is expensive, it is key to use the right after-sales service contract to achieve high equipment availability. Resource-based contracts (RBCs) are common, but they fail to motivate suppliers to provide reliable products and services as suppliers are paid for their after-sales services. Performance-based contracts (PBCs) have been proposed as a way to solve this issue, as it shifts much of the downtime risk to the supplier by making him responsible for machine uptime, but then customers might reduce care efforts. We are the first to analytically incorporate the care in equipment availability. We propose the full-care contract (FCC) to achieve both high reliability and care, and maximize the chain efficiency. We find that only the FCC can achieve full chain efficiency. After discussing potential behavioral factors in this context, with a focus on risk aversion, we conduct a lab study with decision makers as suppliers. Experimental results confirm that the FCC achieves higher total profits than the PBC and RBC. We further find that subjects are more likely to switch from the RBC to the FCC than to the PBC, despite the higher risk involved in the FCC.Finally, we observe that effort levels set by suppliers are above normative predictions and we discuss potential explanations for this result

The relationship of the parotid duct to the buccal and zygomatic branches of the facial nerve; an anatomical study with parameters of clinical interest

There have been studies concerning the protection of the facial nerve during plastic surgery intended for the parotid gland. The close relationship between the parotid duct and the buccal and zygomatic branches of the facial nerve is studied here. The dissections were performed on 10 fixed cadavers at the Anatomy Dissection Laboratory of Ankara University in 2004. The reference points used for surgery of this region were taken into consideration as the landmarks for morphometric measurements. In 7 of the cases the zygomatic branch was double and in 3 it was single. In 4 of the 7 cases with a double zygomatic branch both superior and inferior branches crossed the parotid duct. In the remaining 3 cases the superior branches of the zygomatic nerve coursed through the zygomatic major and minor muscles. In 9 of all the cases the zygomatic branch of the facial nerve crossed the duct anteriorly and in one it did so posteriorly (case 10). The buccal branch was single in 4 of the cases and double in 6. Among these one of the most precise measurements was the distance between the lateral canthus and the intersection point of the zygomatic branch and the duct with a coefficient of variation of 9.9%. With the use of this reliable measurement the intersection point of the zygomatic branch and the duct may be estimated to be within 5.16 ± 1.01 centimetres of the lateral canthus. Facial nerve paralysis is the most important complication of superficial face surgery and the anatomy of this region must thus be taken into detailed consideration by surgeons

Utilisation of Infrared Stabilised Immature Rice Grains in a Cereal Based Fermented Food: Tarhana

Immature rice grain is one of the under-valued by-products of rice milling industry. In this study, it was aimed to investigate the effects of immature rice grain flour (IRGF) substitution to tarhana, which is a traditional cereal-based, fermented food product. IRGF was replaced by refined wheat flour at the levels of 0 (control), 30, 50, 70, and 100%, and the effect of this replacement on the contents of crude fat, ash, protein, dietary fibre, phytic acid, minerals, vitamins B1 and B2, tocopherols, γ-oryzanol contents and sensory properties were investigated. It was shown that stabilised IRGF remarkably improved nutritional properties of the end product without adversely affecting sensory quality up to 50%. In conclusion, it could be suggested that stabilised IRGF has a promising potential for many food applications due to being cheap, accessible, nutritious, and gluten-free

Visualdrives Forensic Tool

Visualdrives is a tool for visualising files stored on a hard drive. The application combines a 3D interactive game-style visualisation combined with a LeapMotion input device providing gesture control over the interface. The purpose of the tool is to understand the potential for abstract digital forensics data to be visualised in a richer, more interactive environment than has traditionally been the case

Image sequence analysis for emerging interactive multimedia services - The European COST 211 framework

Cataloged from PDF version of article.Flexibility and efficiency of coding, content extraction, and content-based search are key research topics in the field of interactive multimedia. Ongoing ISO MPEG-4 and MPEG-7 activities are targeting standardization to facilitate such services. European COST Telecommunications activities provide a framework for research collaboration. COST 211bis and COST 211ter activities have been instrumental in the definition and development of the ITU-T H.261 and H.263 standards for videoconferencing over ISDN and videophony over regular phone lines, respectively. The group has also contributed significantly to the ISO MPEG-4 activities. At present a significant effort of the COST 211ter group activities is dedicated toward image and video sequence analysis and segmentation—an important technological aspect for the success of emerging object-based MPEG-4 and MPEG-7 multimedia applications. The current work of COST 211 is centered around the test model, called the Analysis Model (AM). The essential feature of the AM is its ability to fuse information from different sources to achieve a high-quality object segmentation. The current information sources are the intermediate results from frame-based (still) color segmentation, motion vector based segmentation, and changedetection-based segmentation. Motion vectors, which form the basis for the motion vector based intermediate segmentation, are estimated from consecutive frames. A recursive shortest spanning tree (RSST) algorithm is used to obtain intermediate color and motion vector based segmentation results. A rule-based region processor fuses the intermediate results; a postprocessor further refines the final segmentation output. The results of the current AM are satisfactory; it is expected that there will be further improvements of the AM within the COST 211 project

Supramolecular assemblies constructed by cucurbituril-catalyzed click reaction

Cucurbituril homologues are multi-functional macrocycles that can find applications in many areas and have numerous interesting features setting them apart from the other macrocycles. Among them, the ability of one of the cucurbituril homologues, cucurbit[6]uril (CB6), to catalyze 1,3-dipolar cycloaddition in a regiospecific fashion is truly exceptional. Using this feature, small molecules can be clicked together to form complex structures in a very efficient way. Accordingly, in this article we review recent research involving the use of CB6-catalyzed 1,3-dipolar cycloaddition or the click reaction of CB6 in the construction of supramolecular assemblies including rotaxanes, pseudorotaxanes, polyrotaxanes, polypseudorotaxanes, molecular switches, machines, and nanovalves. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA

The effect of cucurbit[n]uril on the solubility, morphology, and the photophysical properties of nonionic conjugated polymers in an aqueous medium

The effects of cucurbit[n]uril on the dissolution and the photophysical properties of nonionic conjugated polymers in water are described. For this purpose, a fluorine-based polymer, namely, poly[9,9-bis{6(N,N-dimethylamino) hexyl}fluorene-co-2,5-thienylene (PFT) was synthesized and characterized by spectroscopic techniques including 1D and 2D NMR, UV-vis, fluorescent spectroscopy, and matrix-assisted laser desorption mass spectrometry (MALDI-MS). For the first time, it was demonstrated that a nonionic conjugated polymer can be made soluble in water through an inclusion complex formation with CB8. The structure of the complex was elucidated by NMR experiments including 1H and selective 1D-NOESY. This complex emits green and is highly fluorescent with fluorescent quantum yield of 35%. In contrast, CB6 or water-soluble CB7 although they are chemically identical to CB8 do not have any effect on the dissolution and photophysical properties of PFT. By preparing a protonated version of PFT, the optical properties of PFT in methanol, protonated PFT and PFT@CB8 in water have been studied and compared. It was also observed that the morphology of the polymer PFT was affected by the presence of CB8. Thus CB8-assisted self-assembly of polymer chains leads to vesicles formation; these structures were characterized by DLS, AFM, SEM, and TEM fluorescent optical microscopy. © 2010 Wiley Periodicals, Inc

Synthesis and investigation of singlet oxygen production efficiency of photosensitizers based on meso-phenyl-2,5-thienylene linked porphyrin oligomers and polymers

Three new Zn(ii)-, oligo- and poly(2,5-thienylene)-linked porphyrins, bearing multiple triethylene glycol (TEG) groups, on all meso aryl positions were synthesized via Stille and Suzuki coupling reactions and their photophysical properties as well as singlet oxygen generation efficiencies have been investigated to elucidate the possibility of their use as a photosensitizer for photodynamic therapy (PDT) and photodynamic inactivation of bacteria. © The Royal Society of Chemistry 2015