Evaluation of environmental materials as thermal witness materials

New and complex energetic materials are under development for achieving tunable pyrotechnical events for applications such as neutralization of biological weapons, bunker busters and many others. To guide the development of hybrid materials, the pyrotechnical environment they produce requires higher degree of characterization i.e. good description of spatial and temporal temperature distribution. Temperature measurements in pyrotechnical events are especially challenging, where the temperature of the environment rises more than 2000 K on microseconds to few milliseconds time scale. These environments produce high thermal stress where traditional sensors like thermocouples, optical pyrometers struggle to describe the dynamic changes in the environment. The presented research focuses on the development of thermal witness materials that are injected into the combustion environment, where they travel with the expanding gases and undergo a quantifiable physical change/transformation. The extent of change is determined post exposure and a correlation is made between the extent of observed change and the exposed time-temperature profile. The thermosensors under investigation, Jarosite and silicate glass are materials that are ubiquitous in both urban and rural environments. Jarosites undergo decomposition losing (OH) and SO3 upon thermal exposure. The decomposition mechanism is complex and is governed by a set of serial and parallel reactions. The degree of decomposition depends on the exposed thermal profile, and can be easily determined using thermogravimetric analysis. A correlation is made between the residual decomposition and the experienced environment. The limitations and sensitivity for these sensors are presented. The structures of silicate and borate glasses are strongly dependent on the quench rate during glass formation. As an indicator, the glass transition temperature varies linearly with the logarithm of the quench rate. Structural aspects, specifically the degree of connectedness of network forming units [SiO4] and [BO3] can be investigated using Raman spectroscopy. This allows one to recognize variations in the temperature, and cooling rate experienced by the material as it cooled from the high-temperature environment. The use of these sensors to reconstruct the environment temperature profile is under development. The fundamental idea defining the methodology to recover thermal history is discussed

Prevalence, Treatment, and Outcomes of Coexistent Pulmonary Hypertension and Interstitial Lung Disease in Systemic Sclerosis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150609/1/art40862.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150609/2/art40862_am.pd

Nanostructured luminescently labeled nucleic acids

Important and emerging trends at the interface of luminescence, nucleic acids and nanotechnology are: (i) the conventional luminescence labeling of nucleic acid nanostructures (e.g. DNA tetrahedron); (ii) the labeling of bulk nucleic acids (e.g. single‐stranded DNA, double‐stranded DNA) with nanostructured luminescent labels (e.g. copper nanoclusters); and (iii) the labeling of nucleic acid nanostructures (e.g. origami DNA) with nanostructured luminescent labels (e.g. silver nanoclusters). This review surveys recent advances in these three different approaches to the generation of nanostructured luminescently labeled nucleic acids, and includes both direct and indirect labeling methods

Identification of new DNA i-motif binding ligands through a fluorescent intercalator displacement assay

i-Motifs are quadruplex DNA structures formed from sequences rich in cytosine and held together by intercalated, hemi-protonated cytosine–cytosine base pairs. These sequences are prevalent in gene promoter regions and may play a role in gene transcription. Targeting these structures with ligands could provide a novel way to target genetic disease but there are very few ligands which have been shown to interact with i-motif DNA. Fluorescent intercalator displacement (FID) assays are a simple way to screen ligands against DNA secondary structures. Here we characterise how thiazole orange interacts with i-motif DNA and assess its ability for use in a FID assay. Additionally, we report FID-based ligand screening using thiazole orange against the i-motif forming sequence from the human telomere to reveal new i-motif binding compounds which have the potential for further development

Multicenter evaluation of parametric response mapping as an indicator of bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156134/2/ajt15814_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156134/1/ajt15814.pd

G-Quadruplex Visualization in Cells via Antibody and Fluorescence Probe

G-quadruplexes (G4s) are noncanonical nucleic acids structures involved in key regulatory and pathological roles in eukaryotes, prokaryotes, and viruses: the development of specific antibodies and fluorescent probes represent an invaluable tool to understand their biological relevance. We here present three protocols for the visualization of G4s in cells, both uninfected and HSV-1 infected, using a specific antibody and a fluorescent G4 ligand, and the effect of the fluorescent ligand on a G4 binding protein, nucleolin, upon binding of the molecule to the nucleic acids structure

Nanostructured materials for photodynamic therapy: synthesis, characterization and in vitro activity

Three nanostructured vehicles are proposed as potential carriers for photosensitizers to be used in photodynamic therapy: spherical nanoparticles, hexahedral microparticles and cylindrical magnetic nanorods. A comparative study of their photodynamic properties was performed, and the influence of their size and the amount of loaded porphyrin was considered to discuss their effects in the observed photodynamic activity. All the vehicles have a gold surface, allowing functionalization with a disulphide-containing porphyrin as the photosensitizer, as well as with a PEG-containing thiol to improve their biocompatibility and water solubility. The activity of the porphyrin loaded in each vehicle was assessed through in vitro photocytotoxicity studies using HeLa cells. A synergic effect for the porphyrin toxicity was observed in all of the vehicles. The zinc-containing porphyrin showed better production of singlet oxygen, and proved more photocytotoxic both in solution and loaded in any of the vehicles. The magnetism of the nanorods allows targeting with a magnetic field, but causes their aggregation, hampering the porphyrin's activity. Microparticles showed lower cell internalization but their bigger size allowed a high porphyrin loading, which translated into high photocytotoxicity. The highest cell internalization and photocytotoxicity was observed for the porphyrin-loaded nanoparticles, suggesting that a smaller size is favored in cell uptake

Seperation of coseismic and postseismic signals of Sumatra Andaman earthquake and Indian Ocean earthquake

The gravity field changes associated with the earthquake are analysed using the GRACE (Gravity Recovery and Climate Experiment) data. GRACE data can track the temporal variations in the gravity field and therefore information on mass redistribution can be achieved. There have been many studies already carried out using the GRACE data to analyse the coseismic and postseismic effects of the earthquakes. The previous studies mainly concentrated on the separation of the earthquake signals from various other signals and noises to understand the internal mass redistribution. In this work two recent past earthquakes have been considered. Sumatra-Andaman earthquake that occurred on 26th December 2004 with a magnitude of Mw 9.1. The other major earthquake that has been taken into account is the off coast Northern Sumatra earthquake (also called as Indian Ocean earthquake) which occurred on 11th April 2012 with a magnitude of Mw 8.6. A new initiative has been taken to separate the long term postseismic term (2004 earthquake) from the coseismic term and the effects of the 2012 earthquake (both the postseismic and coseismic effect). This decoupling process was done using the GRACE monthly solutions of spherical harmonics. Gravity disturbances were calculated from GRACE monthly solutions to understand the internal mass redistribution. <br/

Examining the deformation in the Krafla region, Iceland: To get an insight on the recent changes in the observed deformation pattern

In the Krafla region in North East Iceland, a change in the deformation pattern was observed in 2018. Since the 1975-1984 rifting event, there was subsidence seen in the Krafla caldera and along the fissure swarm. This subsidence was explained by deflation which decreased exponentially along the years. In 2018, this deformation pattern reversed, and for the first time since 1989, uplift was observed in the region. Therefore, this work concentrates on examining the change in deformation pattern in the region that occurred in 2018. Four geodetic techniques, a combination of ground and space geodetic techniques, are used to study this change in deformation pattern noted in the Krafla region. Data from 2016 to 2019 are considered as they span the time of interest when the change took place. In levelling, InSAR and GPS, the uplift observed is located to the North of the Krafla power plant. Similarly, there is an increase in net gravity seen to the North of the power plant. This suggests there is an increase in mass/density. A possible reason could be movement of magma from the deep to the shallow magma chamber. The reason behind this start of the magma movement is not known. On the other hand, there is continued subsidence and an increase in net gravity seen in the fissure swarms present to the south of the power plant. This result agrees with the fact that the uplift is concentrated (a local phenomena) in the northern region and there is still subsidence seen in the south. A simple Mogi model is fitted to InSAR and GPS data to understand the cause for this change in deformation. But, the fitted model provided very few insights in this work. The results from modelling mainly concentrated on the subsidence in the southern region and corresponding model parameters were obtained. The location of the source responsible for the modelled deformation (subsidence) is found to be near the power plant. The depth and volume however are not properly constrained. But since the model tries to constrain at deeper depths, correspondingly larger volume is also seen. This outcome strengthens the hypothesis that the source for the deformation could lie at deeper depths. Based on the overall results, the following recommendations are made to enhance the results: i) Maintaining the continuity in the data ii) To increase the number of benchmarks measured near the deformation area (especially in gravity and levelling) iii) Use of multiple source modelling for the better understanding of the sub-surface processes