Nanotechnology in multimodal theranostic capsule endoscopy

Video capsule endoscopy (VCE) has become a clinically accepted diagnostic modality in the last 20 years and has established a technological roadmap for other capsule endoscopy (CE) devices, incorporating microscale technology, a local power supply and wireless communication. However, VCE does not provide a therapeutic function and research in therapeutic capsule endoscopy (TCE) has been limited. This paper proposes a new route towards viable TCE based on multiple CE devices including essential nanoscale components. A first device is used for multimodal diagnosis, with quantitative microultrasound as a complement to video imaging. Ultrasound-enhanced fluorescent marking of sites of pathology allows follow-up with a second device for therapy. This is based on fluorescence imaging and ultrasound-mediated targeted drug delivery. Subsequent treatment verification and monitoring with a third device exploits the minimally invasive nature of CE. Clinical implementation of a complete patient pathway remains the subject of research but several key components have been prepared in early prototype form. These are described, along with gaps that remain to be filled

"Delinquent" states, guilty consciences and humanitarian politics in the 1990s

Notions such as ‘guilt’ and ‘forgiveness’ can be defined in objective terms, but more normally have an emotional dimension that cannot be experienced by the institutions examined in this collection of articles. Nevertheless, analogs to these emotions can be discerned in the behaviour of states – and exploring these reveals important insights into what are more (and less) effective ways of responding to, and making amends for, institutional failure. In the 1990s the Western powers were engaged in dealing with a sequence of crises which appeared to call for some kind of intervention – Bosnia 1991/95, Somalia 1992/3, Haiti, 1993/4, Rwanda 1994, Kosovo 1998/9 – and this essay explores the extent to which it can be said that action/inaction in one case can be related back to moral judgements of behaviour in earlier cases. What emerges is not a single narrative of guilt and rectificatory action, but two narratives focusing on different referent objects: obligations towards one's own citizens and toward the putative common good. The picture is complex, yet some significant lessons can be drawn from this analysis. One is the counter-intuitive point that a ‘guilty conscience’ may actually be more effective when the guilt in question is not attributable to the individual whose behaviour is affected, but rather is seen to be borne by the institution that he or she represents. Assuming that guilt is generated by ignorance rather than ill-will, another, more general, lesson is that better intelligence in the broadest sense of the term – including intelligence of the past moral failures of institutions – may be of more value than a (probably difficult to achieve) theory of institutional guilt

Targeted Delivery with Ultrasound Activated Nano-encapsulated Drugs

As a therapeutic modality, targeted drug delivery (TDD) allows an increase in medication dose at a treatment site while avoiding effects in the rest of the human body. TDD can be achieved with different types of delivery vehicles or carriers which encapsulate the free drug and release it only at the target location. Ultrasound-mediated therapeutic drug delivery (USmTDD) is one of various methods for local drug release and it can also influence cell permeability. Furthermore, combining it with magnetic resonance imaging (MRI) provides a controllable system for drug release and impact assessment. In this chapter, one approach to USmTDD is described. This involves the synthesis and assessment of a suitable, novel drug carrier, with the ultrasonic drug release evaluated in vitro using a clinical MRI-guided focused ultrasound surgery (MRgFUS) system. Human cancer cell lines were subjected to Focused Ultrasound (FUS) using the ExAblate 2000 system (InSightec, Haifa, Israel). The experiments were conducted in a specially designed research environment which was comprehensively evaluated to ensure both cell sterility and proper FUS propagation. Various sonication parameters were applied, in conjunction with a commercially available ultrasound contrast agent (USCA), to achieve maximal cellular uptake of doxorubicin (Dox) with minimal decrease in cell viability. In the work presented here, the carrier was a novel cyclodextrin (CD) based molecule that was synthesized, chemically evaluated, and investigated in vitro via two release mechanisms, heating and physical effects, that were differentiated through appropriate detailed experimental protocols.</jats:p

The Nanoporation Project: a Potential New Application of Magnetic Resonance Guided Focused Ultrasound (MRgFUS)

No abstract available

Lamellar Envelopes of Semiconductor Nanocrystals

We report the solution-phase formation of ordered lamellar nanocrystal (NC) arrays. These semiconductor lamellae exhibit structural integrity and temporal stability, without recourse to chemical cross-linking. They are many micrometers in diameter yet only two or three nanocrystal layers in thickness. We show that these structures can integrate a cargo of water-soluble ions, molecules, metal nanoparticles, or biomolecules. Encapsulation of gold nanoparticles is found to cause photoluminescence enhancement of the host CdSe nanocrystals. These easily prepared nanocrystal “envelopes” promise properties modulated through the integration of a vast array of water-soluble species. Our approach marks a step toward ordered, compartmentalized, NC-based complexes with controlled architectures

Lamellar Envelopes of Semiconductor Nanocrystals

We report the solution-phase formation of ordered lamellar nanocrystal (NC) arrays. These semiconductor lamellae exhibit structural integrity and temporal stability, without recourse to chemical cross-linking. They are many micrometers in diameter yet only two or three nanocrystal layers in thickness. We show that these structures can integrate a cargo of water-soluble ions, molecules, metal nanoparticles, or biomolecules. Encapsulation of gold nanoparticles is found to cause photoluminescence enhancement of the host CdSe nanocrystals. These easily prepared nanocrystal “envelopes” promise properties modulated through the integration of a vast array of water-soluble species. Our approach marks a step toward ordered, compartmentalized, NC-based complexes with controlled architectures

Report of round robin exercise on effect of EDM notching and fatigue precracking methods on CTOD fracture toughness values of welds

SIGLEAvailable from TIB Hannover: RA 3251(91/E/91) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman