1,721,136 research outputs found
Towards informed conservation: characterising the state of deterioration of weighted silk
No full textProbing the microstructure of protein and polyamide fibres
No full textThe chemical, structural and physical properties of a range of proteinaceous and polyamide fibres, including silk, wool, nylon and various modern and historic regenerated proteins, have been assessed. The chemistry and microstructure of both pristine and artificially aged specimens of the fibres have been investigated using conventional and polarised infrared spectroscopy. Correlations have been drawn between these results and data derived from mechanical testing, demonstrating that the nature and state of such materials can be adequately characterised by analytical methods requiring minimal intervention. This will be of value in exploring the history and informing the identification, conservation, display and storage of artefacts containing these fibres
A novel method to allow noninvasive, longitudinal imaging of the murine immune system in vivo
Full text linkIn vivo imaging has revolutionized understanding of the spatiotemporal complexity that subserves the generation of successful effector and regulatory immune responses. Until now, invasive surgery has been required for microscopic access to lymph nodes (LNs), making repeated imaging of the same animal impractical and potentially affecting lymphocyte behavior. To allow longitudinal in vivo imaging, we conceived the novel approach of transplanting LNs into
the mouse ear pinna. Transplanted LNs maintain the structural and cellular organization of conventional secondary lymphoid organs. They participate in lymphocyte
recirculation and exhibit the capacity to receive and respond to local antigenic challenge. The same LN could be repeatedly imaged through time without the requirement for surgical exposure, and the dynamic behavior of the cells within the transplanted LN could be characterized. Crucially, the use of blood vessels as fiducial markers also allowed precise re-registration of the same regions for
longitudinal imaging. Thus, we provide the first demonstration of a method for repeated, noninvasive, in vivo imaging of lymphocyte behavior
Monitoring the deterioration of historic textiles: developing appropriate micromethodology
No full textMethods are needed for indirectly assessing the physical state of historic textiles and further assessing the risk of display. Infrared spectroscopy offers a microsampling technique that can probe both the microstructure and chemistry of materials. A cellulose crystallinity index can be derived for plant fibres. Additional details were extracted from polarised spectra, with the coupled data allowing an estimate of the oriented fraction of the microfibrillar component. Applying this protocol to linen fibres suggested a 30% amorphous and 70% crystalline cellulose content, with 70% of the latter being well oriented. The relative changes in fractional oriented crystallinity were found to differ dramatically for a modern and a 16th-century linen, following accelerated ageing. However, there was no direct correlation with the breaking strain, and the change in mechanical behaviour could not be predicted with certainty on the basis of the oriented crystallinity parameter alone
Images in cardiovascular medicine : multiphoton microscopy for three-dimensional imaging of lymphocyte recruitment into apolipoprotein-E-deficient mouse carotid artery
No full textTwo recent elegant studies have shown that in apolipoprotein-E– deficient mice, the lamina adventitia is a major site of arterial wall inflammation associated with lymphocyte infiltration into atherosclerotic arteries and with formation of adventitial lymphoid-like tissues.1,2 These results suggest that lymphocyte responses in the lamina adventitia may play a crucial role in atherosclerosis development.1,
Advances in imaging of new targets for pharmacological intervention in stroke: real-time tracking of T-cells in the ischaemic brain
Full text linkBackground and purpose: T‐cells may play a role in the evolution of ischaemic damage and repair, but the ability to image these cells in the living brain after a stroke has been limited. We aim to extend the technique of real‐time in situ brain imaging of T‐cells, previously shown in models of immunological diseases, to models of experimental stroke.
Experimental approach: Male C57BL6 mice (6–8 weeks) (n= 3) received a total of 2–5 × 106 carboxyfluorescein diacetate succinimidyl ester (CFSE)‐labelled lymphocytes from donor C57BL6 mice via i.v. injection by adoptive transfer. Twenty‐four hours later, recipient mice underwent permanent left distal middle cerebral artery occlusion (MCAO) by electrocoagulation or by sham surgery under isoflurane anaesthesia. Female hCD2‐green fluorescent protein (GFP) transgenic mice that exhibit GFP‐labelled T‐cells underwent MCAO. At 24 or 48 h post‐MCAO, a sagittal brain slice (1500 µm thick) containing cortical branches of the occluded middle cerebral artery (MCA) was dissected and used for multiphoton laser scanning microscopy (MPLSM).
Key results: Our results provide direct observations for the first time of dynamic T‐cell behaviour in living brain tissue in real time and herein proved the feasibility of MPLSM for ex vivo live imaging of immune response after experimental stroke.
Conclusions and Implications: It is hoped that these advances in the imaging of immune cells will provide information that can be harnessed to a therapeutic advantage
Vibrational microspectroscopic characterisation of sailcloth: monitoring the deterioration of historic marine textiles
No full textAssessing near infrared and terahertz spectroscopy for the characterisation of organic heritage artefacts
No full textOur objective is to define the most appropriate non-contact spectroscopic protocol with which to interrogate the identity, moisture content and chemical character of organic heritage artefacts, as exemplified by textiles, for informed conservation and long-term preservation. Here we report initial work on the application of near infrared (NIR) and terahertz (THz) spectroscopy to the analyses of natural fibre textiles.
NIR wavelengths are sufficiently short for efficient transmission of the radiation through fibre optics, so that remote sampling is possible. THz spectroscopy has been developed much more recently as an analytical tool, and also offers a truly non-destructive approach. We have recorded non-contact NIR (7800 - 4000 cm?1) and THz (10GHz - 2THz) spectra of linen and other textile fabrics. While the terahertz spectra are not immediately distinct, the near infrared spectra allow differentiation of the broad categories of textiles. THz absorption increases with moisture sorption; besides microstructural and chemical information, NIR spectra may also reveal the moisture content of fabrics. A preliminary analysis of linen suggests that by providing this information non-invasively, NIR spectroscopy has the potential for on-site monitoring of the deterioration state of fabrics
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