4,745 research outputs found
Characterization, cloning and immunogenicity of antigens released by lung-stage larvae of Schistosoma mansoni
Lung-stage schistosomula are the target of protective immunity in mice vaccinated with attenuated cercariae of Schistosoma mansoni. Therefore, proteins present at this developmental stage, and in particular those which are secreted, are a potential source of novel vaccine candidates. However, little information is available about such molecules. Here we describe the cDNA clones identified by screening expression libraries with serum raised against proteins released by lung-stage schistosomula. In total, 11 different cDNA species were identified, 6 of which have been described previously in S. mansoni; these included fructose 1,6-bisphosphate aldolase and Sm21.7 which together accounted for two-thirds of all positive clones. Of the 5 newly described schistosome genes, 1 cDNA had a high degree of homology to the s5a subunit of 26S proteasomes, most significant being with the human protein. The remaining 4 clones showed no significant homologies to any genes sequenced previously. Fructose 1,6-bisphosphate aldolase, Sm21.7, the proteasome homologue and 1 unknown clone (A26) have been expressed in a bacterial expression system and serum produced against each recombinant protein. Immunolocalization showed fructose 1,6-bisphosphate aldolase, Sm21.7 and the proteasome homologue to be most abundant in muscle cells whilst clone A26 was distributed throughout many tissues, but was most abundant in the tegument. Analysis of the cellular immune responses of vaccinated mice showed 3 of the 4 expressed clones to be highly immunogenic, inducing the secretion of large quantities of the Th1-type cytokine interferon gamma
Carbon Nitride as a Ligand: Synthesis, Characterisation and Application
Carbon nitrideâs properties can be tuned through the coordination of metal atoms, which can lead to enhanced catalytic activity. However, to date, there are few reported examples of inner-sphere coordination of metal complex fragments to carbon nitride. Therefore, the effects of coordination of metal complex fragments to carbon nitride haves been investigated.
Reaction of the rhenium carbonyl complex, [ReCl(CO)5] with the surface of urea-derived carbon nitride (UCN) results in [ReCl(CO)3(UCN)], with a rhenium concentration of 0.39 mmol g-1. The synthesis of the manganese analogue resulted in manganese oxidation leading to [Mn(UCN)] ([Mn] = 0.24 mmol g-1). Infrared spectroscopy, along with crystal structures of molecular analogues, [MCl(CO)3(DMNA-Îș2N, Nâ)] (M = Re, Mn) was used to gain insight into the coordination of metals complex fragments to carbon nitride.
Two morphologies of carbon nitride, unstructured urea-derived carbon nitride (UCN) and porous cyanamide derived carbon nitride (CCN), were then decorated with [Ru(bpy)2]2+ fragments. The carbon nitride structure affected metal loading, as [Ru(bpy)2(UCN)](PF6)2 ([Ru] = 0.016 mmol g-1) showed lower metal loading compared to [Ru(bpy)2(CCN)](PF6)2 ([Ru] = 0.076 mmol g-1). [Ru(bpy)2(DMNA-Îș2N, Nâ)](PF6)2 was synthesised as a molecular analogue to gain insight into the coordination mode. The photocatalytic activities of [Ru(bpy)2(UCN)](PF6)2 and [Ru(bpy)2(UCN)](PF6)2 were completely inhibited compared to the undecorated materials. EPR and photoluminescence suggested the presence of rapid, efficient quenching of excited states in ruthenium decorated carbon nitride.
[IrCl2Cp*(UCN)] ([Ir] = 0.069 mmol g-1) was synthesised to design a novel, recyclable hydrogenation catalyst. Direct hydrogenation reactions were carried out using hexane as a solvent, and despite low activity, [IrCl2Cp*(UCN)] showed good selectivity toward terminal alkenes and over 80% of catalytic activity was retained after 5 catalytic runs.
Direct coordination of metal complex fragments to carbon nitride is shown to be a viable route to tuning the properties of carbon nitride and developing recyclable novel catalysts
A sensory-guided surgical micro-drill
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 The Authors.This article describes a surgical robotic device that is able to discriminate tissue interfaces and other controlling parameters ahead of the drill tip. The advantage in such a surgery is that the tissues at the interfaces can be preserved. A smart tool detects ahead of the tool point and is able to control the interaction with respect to the flexing tissue, to avoid penetration or to control the extent of protrusion with respect to the position of the tissue. For surgical procedures, where precision is required, the tool offers significant benefit. To interpret the drilling conditions and the conditions leading up to breakthrough at a tissue interface, a sensing scheme is used that discriminates between the variety of conditions posed in the drilling environment. The result is a fully autonomous system, which is able to respond to the tissue type, behaviour, and deflection in real-time. The system is also robust in terms of disturbances encountered in the operating theatre. The device is pragmatic. It is intuitive to use, efficient to set up, and uses standard drill bits. The micro-drill, which has been used to prepare cochleostomies in the theatre, was used to remove the bone tissue leaving the endosteal membrane intact. This has enabled the preservation of sterility and the drilling debris to be removed prior to the insertion of the electrode. It is expected that this technique will promote the preservation of hearing and reduce the possibility of complications. The article describes the device (including simulated drill progress and hardware set-up) and the stages leading up to its use in the theatre.Queen Elizabeth Hospital, Birmingham, U
Flexible programmable networking: A reflective, component-based approach
The need for programmability and adaptability in networking systems is becoming increasingly important. More specifically, the challenge is in the ability to add services rapidly, and be able to deploy, configure and reconfigure them as easily as possible. Such demand is creating a considerable shift in the way networks are expected to operate in the future. This is the main aim of programmable networking research community, and in our project we are investigating a component-based approach to the structuring of programmable networking software. Our intention is to apply the notion of components, component frameworks and reflection ubiquitously, thus accommodating all the different elements that comprise a programmable networking system
Avoidance of the real and anxiety about the unreal: attachment style and video-gaming
In this article, the authors discuss the light and dark side of attachments and attachment style in physical and digital worlds. They argue that many games offer opportunities for the generation of new and meaningful attachments to both physical and digital others. They discuss two âfundamental attachment errorsâ and show how these can lead to both âlightâ outcomes, in terms of opportunities to learn more secure attachment patterns, and âdarkâ outcomes, where existing dysfunctional behaviours become more pronounced. The authors argue that the avatars which children adopt online have important consequences for their psychosocial development, and that these are mediated through the degree to which the real self is differentiated from the avatar. It is proposed that attachment is a key force in understanding play, and that studying its manifestations and effects in digital playscapes may contribute to understanding the effects of life online, and how insecure attachments may become secure
Feasibility study of a hand guided robotic drill for cochleostomy
The concept of a hand guided robotic drill has been inspired by an automated, arm supported robotic drill recently applied in clinical practice to produce cochleostomies without penetrating the endosteum ready for inserting cochlear electrodes. The smart tactile sensing scheme within the drill enables precise control of the state of interaction between tissues and tools in real-time. This paper reports development studies of the hand guided robotic drill where the same consistent outcomes, augmentation of surgeon control and skill, and similar reduction of induced disturbances on the hearing organ are achieved. The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator. The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory. This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced. The results for trials on phantoms show that drill unit compliance is an important factor in the design
Energy dependence on fractional charge for strongly interacting subsystems
The energies of a pair of strongly-interacting subsystems with arbitrary
noninteger charges are examined from closed and open system perspectives. An
ensemble representation of the charge dependence is derived, valid at all
interaction strengths. Transforming from resonance-state ionicity to ensemble
charge dependence imposes physical constraints on the occupation numbers in the
strong-interaction limit. For open systems, the chemical potential is evaluated
using microscopic and thermodynamic models, leading to a novel correlation
between ground-state charge and an electronic temperature.Comment: 4 pages, 3 figs.; as accepted (Phys. Rev. Lett.
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