Feasibility of Geological Carbon Dioxide Storage; From Exploration to Implementation

This study utilises a range of techniques to investigate the feasibility of the geological storage of carbon dioxide. Three specific themes were addressed. Saline aquifers have been proposed as an attractive geological storage medium due to the theoretical storage capacity offered, despite the poor quality and quantity of date available to appraise them. Published methodologies are numerous, which attempt to refine the uncertainty by the introduction of capacity coefficients producing estimates with a variance of up to five orders of magnitude. The source of this uncertainty is investigated using Monte Carlo based sensitivity on a North Sea case study site. This shows the limitations and sources of error inherent in the application of such method. A new method is proposed to account for the limited available input data. Injectivity of geological reservoirs has been highlighted as a potential setback for CO2 storage. Reservoir hosted compartmentalising membrane seals are shown to permit CO2 migration without compromising storage integrity in three North Sea examples. The presence of oil as a wetting fluid in the substrate significantly reduces the capillary entry pressure of a membrane seal as a product of CO2 water contact angle of cos 85° to cos 90°. Cross fault flow rates are shown to be on operational timescales. CO2 storage projects have been cancelled as a consequence of public objection. Public Engagement has been proven to affect the public’s perception of CCS in both positive and negative directions by facilitating informed decision making. The perception of trust and impartiality are demonstrated to outdo the perception of knowledge and experience. Furthermore the perceived benefits of CCS are evidenced to be tempered by person’s preordained perception either of the technology, or those who advocate it

Ultrafast electron dynamics in thin films of Prussian Blue analogues

The potentially complex energy redistribution processes that occur in inorganic transition metal complexes make the interpretation of their relaxation dynamics a significant challenge. Unlike in organic molecules, where rates for processes such as intersystem crossing can take up to and in excess of many nanoseconds, the timescales involved in inorganic materials are of picosecond / femtosecond timescales and therefore require a more advanced experimental setup to study them. The dynamic processes that are of interest are the evolution of the electron population after excitation through external stimuli, via the various charge transfer and decay processes. These processes can also induce changes in the population of the valence orbitals on the metal ion centres causing a change to the overall spin state. This work aims to develop techniques to monitor the redistribution of the electron population along with the magnetisation of the materials of interest. The dynamic processes are much too fast to be captured using standard spectrometers and magnetic techniques, so a technique which can operate on these very fast timescales is required. Ultrafast laser spectroscopy allows study of the electronic dynamics using a technique called transient transmission which involves studying changes in the transmission spectrum as a function of time. Two laser pulses are employed, one to perturb the sample and another to interrogate the sample. By varying the time delay between the two pulses a picture of how the spectrum changes over time can be constructed. This process allows a picture to be built, of how the electronic population redistributes and decays after excitation. In order to study the magnetisation dynamics of such materials the samples are required to exhibit a magnetic signal. To this end, a magnetically ordered family of inorganic compounds known as Prussian Blues were chosen as the system of interest. These materials consist of transition metal ions linked through cyanide bridging ligands in a rock-salt type structure. Laser spectroscopy was used to monitor the changes in the magnetisation of the sample through a technique called magneto-optical Faraday rotation. This involves monitoring the polarisation of the laser pulses after interaction with the sample, again, at various time delays to measure how the magnetisation of the sample changes over time. These techniques were applied to three chromium based Prussian Blues, vanadium-chromium (VCr), iron-chromium (FeCr) and the chromium-chromium (CrCr) analogues. Through the systematic substitution of the metal ion adjacent to the Cr sites, it was found that the rate of intersystem crossing could be influenced by the nature of the metal center. In the case of both VCr and FeCr analogues, the transfer of population to the final excited state occurred incredibly fast, within the temporal profile of the pump pulse. However, in the case of the CrCr analogue, this population transfer was slowed down suffciently that a growth of the final excited state was observed over the course of the initial 0.5 ps after excitation. The synthesis of these materials was carried out to optimise the morphology of the thin films for use in the laser measurements. During this work it was found that some of these materials exhibit electrochromic activity which was explored in isolated films and as part of multilayered heterostructures. This work was also incredibly helpful with understanding and predicting the spectral signatures of redox processes involved after photo-excitation. This line of research offers the potential to gain a deeper understanding of the dynamic processes occurring in these functional materials which will serve as model systems. The information gained can then be applied to a broader range of complexes. Functional materials which possess much higher magnetic ordering temperatures or larger magnetisation would have a greater potential to be used in future practical applications

Capacity Assessment and Information Provision for Voluntary Psychiatric Patients: a service evaluation in a UK NHS Trust

Since the Cheshire West judgement, yearly applications for the Mental Health Act (MHA) and Deprivation of Liberty Safeguards (DoLS) have increased, though many patients are still admitted informally. To ensure lawfulness, informal admissions must be capacitous, informed, and without coercion. If fully capacitous consent is not obtained, then there is a risk of “de facto” detention and deprivation of liberty.  Deprivation of liberty is only lawful through appropriate legal frameworks (DoLS for incapacitous, non-objecting hospital inpatients, or MHA otherwise).  Use of such legal frameworks might be hampered by the perceived stigma associated with them, though this may not be in the best interests of the patient.We aimed to examine the assessment of capacity and provision of adequate information required for an informed voluntary psychiatric admission, and any evidence of possible coercion into informal admission. We postulate variable use of legal frameworks designed to empower patients and prevent illegal deprivation of liberty

Improving the efficiency of the later stages of the drug development process : survey results from the industry, academia, and the FDA

Thesis (S.M.)--Harvard-MIT Division of Health Sciences and Technology, 2004.Includes bibliographical references (p. 65).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Drug development in the United States is a lengthy and expensive endeavor. It is estimated that average development times range from eleven to fifteen years and exceed costs of one billion dollars. The development pathway includes basic scientific discovery, pre-clinical testing in animals, clinical development in humans, and an application process. The Food and Drug Administration is responsible for the oversight and approval of drugs going through this process. Numerous financial and economic studies have been conducted that show the benefits to accelerating the drug development process. In 1992, the United States Congress enacted the Prescription Drug User Fee Act I, which mandated faster response times from the FDA in return for user fee payments to the FDA by the drug developing companies. Data on approval times for new drugs indicate that this process was indeed shortened. In contrast, the average drug development process prior to the filing of an application has been increasing in cost and time. The first purpose of this research is to quantify the benefits of accelerated new drug application review time under the Prescription Drug User Fee Acts I and II. The second purpose of the research is to investigate what industry and the FDA can do together to reduce the development process time between the IND and NDA without compromising patient safety and welfare, specifically the Phase II, Phase III, and NDA components. The research indicates that PDUFA has improved approval times in a statistically significant way. Furthermore, the financial and social benefits as measured using net present value have far exceeded the PDUFA costs. Quantitative and qualitative surveys of fifty individuals in large pharmaceutical and biotech companies(cont.) resulted in the identification of several significant opportunities and useful suggestions for reducing development times in Phase II, Phase III, and the NDA. Specifically, company interviewees indicated that they were willing to pay additional monies for increased interaction and communication with the FDA from Phase II through the NDA in hopes of reducing information asymmetry and increasing information transparency. Other recommendations included a mandatory audit and review of a sample of NDAs post approval to identify best practices, implementation of metrics and performance tracking during clinical phases, and implementation of consistent project management and communication standards across therapeutic divisions.by Adrian Hedley Benjamin Gottschalk.S.M

Adaptation of Semiautomated Circulating Tumor Cell (CTC) Assays for Clinical and Preclinical Research Applications

The majority of cancer-related deaths occur subsequent to the development of metastatic disease. This highly lethal disease stage is associated with the presence of circulating tumor cells (CTCs). These rare cells have been demonstrated to be of clinical significance in metastatic breast, prostate, and colorectal cancers. The current gold standard in clinical CTC detection and enumeration is the FDA-cleared CellSearch system (CSS). This manuscript outlines the standard protocol utilized by this platform as well as two additional adapted protocols that describe the detailed process of user-defined marker optimization for protein characterization of patient CTCs and a comparable protocol for CTC capture in very low volumes of blood, using standard CSS reagents, for studying in vivo preclinical mouse models of metastasis. In addition, differences in CTC quality between healthy donor blood spiked with cells from tissue culture versus patient blood samples are highlighted. Finally, several commonly discrepant items that can lead to CTC misclassification errors are outlined. Taken together, these protocols will provide a useful resource for users of this platform interested in preclinical and clinical research pertaining to metastasis and CTCs

High aldehyde dehydrogenase and expression of cancer stem cell markers selects for breast cancer cells with enhanced malignant and metastatic ability

Cancer stem cells (CSCs) have recently been identified in leukaemia and solid tumours; however, the role of CSCs in metastasis remains poorly understood. This dearth of knowledge about CSCs and metastasis is due largely to technical challenges associated with the use of primary human cancer cells in pre-clinical models of metastasis. Therefore, the objective of this study was to develop suitable pre-clinical model systems for studying stem-like cells in breast cancer metastasis, and to test the hypothesis that stem-like cells play a key role in metastatic behaviour. We assessed four different human breast cancer cell lines (MDA-MB-435, MDA-MB-231, MDA-MB-468, MCF-7) for expression of prospective CSC markers CD44/CD24 and CD133, and for functional activity of aldehyde dehydrogenase (ALDH), an enzyme involved in stem cell self-protection. We then used fluorescence-activated cell sorting and functional assays to characterize differences in malignant/metastatic behaviour in vitro (proliferation, colony-forming ability, adhesion, migration, invasion) and in vivo (tumorigenicity and metastasis). Sub-populations of cells demonstrating stem-cell-like characteristics (high expression of CSC markers and/or high ALDH) were identified in all cell lines except MCF-7. When isolated and compared to ALDHlowCD44low/- cells, ALDHhiCD44+CD24- (MDA-MB-231) and ALDHhiCD44+CD133+ (MDA-MB-468) cells demonstrated increased growth (P \u3c 0.05), colony formation (P \u3c 0.05), adhesion (P \u3c 0.001), migration (P \u3c 0.001) and invasion (P \u3c 0.001). Furthermore, following tail vein or mammary fat pad injection of NOD/SCID/IL2 gamma receptor null mice, ALDHhiCD44+CD24- and ALDHhiCD44+CD133+ cells showed enhanced tumorigenicity and metastasis relative to ALDHlowCD44low/- cells (P \u3c 0.05). These novel results suggest that stem-like ALDHhiCD44+CD24- and ALDHhiCD44+CD133+ cells may be important mediators of breast cancer metastasis

Tetrathiafulvalene-oligofluorene star-shaped systems : new semiconductor materials for fluorescent moisture indicators

A series of novel star-shaped oligofluorene–thiophene–tetrathiafulvalene systems have been synthesised, following different synthetic routes. Each system incorporates a tetrathiafulvalene redox-active centre and four oligofluorene arms, providing a two-dimensional character to the conjugated backbone. The oligomers differ in the number of fluorene units present in the arms (1 to 4) and the terminal groups at the end of each arm (H or trimethylsilyl). Half-unit oligofluorene systems possessing a 1,3-dithiole-2-one core (a known precursor to the tetrathiafulvalene centre) have been synthesised in order to compare the thermal, optical and electrochemical properties. These half-unit systems consist of a 1,3-dithiole-2-one core fused to a thiophene unit at the 3- and 4-positions. Two oligofluorene arms consisting of 1 to 4 monomer units per arm are positioned at the 4- and 6-positions of the thiophene unit, affording extended conjugation through the thiophene centre. The half-unit systems are found to be moderate emitters in solution, however, the star-shaped systems bearing the tetrathiafulvalene core exhibit inhibited fluorescence in both solution and the solid state. We have demonstrated that the emission of the tetrathiafulvalene systems can be enhanced through the oxidation of the redox-centre followed by a consecutive reaction of the strongly electrophilic tetrathiafulvalene dication with such nucleophiles as water and hydrazine. The result of these reactions leads to an increase in the photoluminescence of these systems, affording the opportunity for the tetrathiafulvalene materials to be used as photonic materials in moisture indicators

Large-scale screening of preferred interactions of human src homology-3 (SH3) domains using native target proteins as affinity ligands

The Src Homology-3 (SH3) domains are ubiquitous protein modules that mediate important intracellular protein interactions via binding to short proline-rich consensus motifs in their target proteins. The affinity and specificity of such core SH3-ligand contacts are typically modest, but additional binding interfaces can give rise to stronger and more specific SH3-mediated interactions. To understand how commonly such robust SH3 interactions occur in the human protein interactome, and to identify these in an unbiased manner we have expressed 324 predicted human SH3 ligands as full-length proteins in mammalian cells, and screened for their preferred SH3 partners using a phage display-based approach. This discovery platform contains an essentially complete repertoire of the ∼300 human SH3 domains, and involves an inherent binding threshold that ensures selective identification of only SH3 interactions with relatively high affinity. Such strong and selective SH3 partners could be identified for only 19 of these 324 predicted ligand proteins, suggesting that the majority of human SH3 interactions are relatively weak, and thereby have capacity for only modest inherent selectivity. The panel of exceptionally robust SH3 interactions identified here provides a rich source of leads and hypotheses for further studies. However, a truly comprehensive characterization of the human SH3 interactome will require novel high-throughput methods based on function instead of absolute binding affinity

HIV infection and stroke:current perspectives and future directions

HIV infection can result in stroke via several mechanisms, including opportunistic infection, vasculopathy, cardioembolism, and coagulopathy. However, the occurrence of stroke and HIV infection might often be coincidental. HIV-associated vasculopathy describes various cerebrovascular changes, including stenosis and aneurysm formation, vasculitis, and accelerated atherosclerosis, and might be caused directly or indirectly by HIV infection, although the mechanisms are controversial. HIV and associated infections contribute to chronic inflammation. Combination antiretroviral therapies (cART) are clearly beneficial, but can be atherogenic and could increase stroke risk. cART can prolong life, increasing the size of the ageing population at risk of stroke. Stroke management and prevention should include identification and treatment of the specific cause of stroke and stroke risk factors, and judicious adjustment of the cART regimen. Epidemiological, clinical, biological, and autopsy studies of risk, the pathogenesis of HIV-associated vasculopathy (particularly of arterial endothelial damage), the long-term effects of cART, and ideal stroke treatment in patients with HIV are needed, as are antiretrovirals that are without vascular risk

Epitope-specific antibody responses differentiate COVID-19 outcomes and variants of concern

BACKGROUND. The role of humoral immunity in COVID-19 is not fully understood, owing, in large part, to the complexity of antibodies produced in response to the SARS-CoV-2 infection. There is a pressing need for serology tests to assess patient-specific antibody response and predict clinical outcome. METHODS. Using SARS-CoV-2 proteome and peptide microarrays, we screened 146 COVID-19 patients’ plasma samples to identify antigens and epitopes. This enabled us to develop a master epitope array and an epitope-specific agglutination assay to gauge antibody responses systematically and with high resolution. RESULTS. We identified linear epitopes from the spike (S) and nucleocapsid (N) proteins and showed that the epitopes enabled higher resolution antibody profiling than the S or N protein antigen. Specifically, we found that antibody responses to the S-811–825, S-881–895, and N-156–170 epitopes negatively or positively correlated with clinical severity or patient survival. Moreover, we found that the P681H and S235F mutations associated with the coronavirus variant of concern B.1.1.7 altered the specificity of the corresponding epitopes. CONCLUSION. Epitope-resolved antibody testing not only affords a high-resolution alternative to conventional immunoassays to delineate the complex humoral immunity to SARS-CoV-2 and differentiate between neutralizing and non-neutralizing antibodies, but it also may potentially be used to predict clinical outcome. The epitope peptides can be readily modified to detect antibodies against variants of concern in both the peptide array and latex agglutination formats. FUNDING. Ontario Research Fund (ORF) COVID-19 Rapid Research Fund, Toronto COVID-19 Action Fund, Western University, Lawson Health Research Institute, London Health Sciences Foundation, and Academic Medical Organization of Southwestern Ontario (AMOSO) Innovation Fund