Microbial biodegradation of various classes of ignitable liquids in forensic soil samples

Identification of ignitable liquids in fire debris analysis using pattern recognition is an important step in determining the nature of a suspicious fire. Complex mixtures that make up ignitable liquids are susceptible to microbial degradation when fire debris evidence is presented in the form of soil. Microbial degradation results in a selective metabolism of certain classes of compounds required for identification of an ignitable liquid. Various ignitable liquids that may be used to initiate or propagate a fire contain different classes of organic compounds. These include normal alkanes, branched alkanes, cycloalkanes, aromatics, terpenes, and others. In this work, microbial degradation of nine ignitable liquids in soil was evaluated over a period of twenty-six days. The degradation of aromatic compounds in gasoline was faster with toluene and C2-alkylbenzenes than in C3-alkylbenzenes. However, the overall loss of aromatics made gasoline chromatographically unidentifiable. The complete loss of n-alkanes in medium and petroleum distillates resulted in patterns that resembled naphthenic-paraffinic products. Normal alkanes were more susceptible to microbial degradation than isoalkanes, which was specifically demonstrated in medium and heavy petroleum distillates. In diesel, pristane and phytane remained prominent in comparison to the normally prevalent n-alkanes, which could no longer be detected post-degradation. The degradation of isoalkanes and cycloalkanes was evaluated in a naphthenic-paraffinic product. Isoalkanes were degraded significantly faster than cycloalkanes. The remaining peaks in the naphthenic-paraffinic pattern consisted solely of cycloalkane compounds, and could no longer be classified as a naphthenic-paraffinic product. The terpene compounds in turpentine were also observed to be susceptible to degradation by microorganisms. The loss of !-pinene, limonene, and camphene was significantly noticeable in comparison to other terpene compounds, such as 1,4-cineole. Microbial biodegradation in different soil types was investigated. The difference in soil texture can affect the rate of metabolism of ignitable liquids due to the variance of available oxygen, nutrients and mobility of the microbial population. The degradation of isoalkanes, cycloalkanes, aromatics and heavier normal alkanes was faster in clay, whereas normal alkanes of lower molecular weight were degraded more readily in sand. There has been no explanation of this occurrence within the scientific literature, however it could be hypothesized that the difference in microbial flora and water saturation levels could affect the selective degradation between the two soil types. Fire debris evidence is often stored for long periods of time before analysis due to case backlogs. The storage condition of arson-related soil samples is a sensitive subject. If evidence, containing soil, is stored at room temperature, petroleum compounds in any ignitable liquid residues that are present will be degraded within a week. Therefore, it is important to freeze or refrigerate soil samples. The storage of both refrigerated and frozen soil samples containing gasoline were evaluated over six months. Less than 6% of the aromatic compounds distinctive of gasoline remained when stored at 5 °C, while minimal change was observed in the same compounds when stored at -15 °C. Microbial degradation of petroleum-based ignitable liquids is advantageous from the environmental perspective. However, within the forensic community the effect of microbial action could lead to misclassification or inability to identify the presence of an ignitable liquid in fire debris evidence

Solid-Phase Synthesis of Asymmetrically Substituted Phthalocyanines

Phthalocyanines (Pcs) are excellent candidates for use as fluorophores for near-infrared (near-IR) fluorescent tagging of biomolecules and as photodynamic therapy (PDT) agents. Synthesis of Pcs with asymmetrical substitution on the periphery is often difficult due to the problems during the purification of the Pc mixtures obtained. The objective of this project is to design and synthesize chemically robust near-IR fluorophores for bioanalytical applications and to develop new synthetic methods for rapid synthesis of the target compounds. A novel synthetic route was developed utilizing a hydrophilic, polyethylene glycol-based (PEG) support with different types of linkers. The Pcs were functionalized with either hydroxyl or amine groups for covalent conjugation purposes and were decorated with solubilizing groups such as carboxylic acids and short PEG chains. Monohydroxyl and mono-amine functionalized oligoethylene glycol substituted Pcs were synthesized via a solid-phase phthalonitrile tetramerization reaction. In order to alter the photophysical properties of the desired compounds different metals were inserted in the cavity of the macrocycle. The potential of several of the compounds for PDT has been evaluated in vitro. Generally, these compounds are readily taken up in cells, have very low dark toxicity, exhibit rapid toxicity in near-infrared light, and are broadly dispersed in the cell including in lysosomes and in the endoplasmic reticulum

Small business innovation research. Abstracts of completed 1987 phase 1 projects

Non-proprietary summaries of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA in the 1987 program year are given. Work in the areas of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robotics, computer sciences, information systems, spacecraft systems, spacecraft power supplies, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered

NASA Tech Briefs, March 2014

Topics include: Data Fusion for Global Estimation of Forest Characteristics From Sparse Lidar Data; Debris and Ice Mapping Analysis Tool - Database; Data Acquisition and Processing Software - DAPS; Metal-Assisted Fabrication of Biodegradable Porous Silicon Nanostructures; Post-Growth, In Situ Adhesion of Carbon Nanotubes to a Substrate for Robust CNT Cathodes; Integrated PEMFC Flow Field Design for Gravity-Independent Passive Water Removal; Thermal Mechanical Preparation of Glass Spheres; Mechanistic-Based Multiaxial-Stochastic-Strength Model for Transversely-Isotropic Brittle Materials; Methods for Mitigating Space Radiation Effects, Fault Detection and Correction, and Processing Sensor Data; Compact Ka-Band Antenna Feed with Double Circularly Polarized Capability; Dual-Leadframe Transient Liquid Phase Bonded Power Semiconductor Module Assembly and Bonding Process; Quad First Stage Processor: A Four-Channel Digitizer and Digital Beam-Forming Processor; Protective Sleeve for a Pyrotechnic Reefing Line Cutter; Metabolic Heat Regenerated Temperature Swing Adsorption; CubeSat Deployable Log Periodic Dipole Array; Re-entry Vehicle Shape for Enhanced Performance; NanoRacks-Scale MEMS Gas Chromatograph System; Variable Camber Aerodynamic Control Surfaces and Active Wing Shaping Control; Spacecraft Line-of-Sight Stabilization Using LWIR Earth Signature; Technique for Finding Retro-Reflectors in Flash LIDAR Imagery; Novel Hemispherical Dynamic Camera for EVAs; 360 deg Visual Detection and Object Tracking on an Autonomous Surface Vehicle; Simulation of Charge Carrier Mobility in Conducting Polymers; Observational Data Formatter Using CMOR for CMIP5; Propellant Loading Physics Model for Fault Detection Isolation and Recovery; Probabilistic Guidance for Swarms of Autonomous Agents; Reducing Drift in Stereo Visual Odometry; Future Air-Traffic Management Concepts Evaluation Tool; Examination and A Priori Analysis of a Direct Numerical Simulation Database for High-Pressure Turbulent Flows; and Resource-Constrained Application of Support Vector Machines to Imagery

Inhibiitorid ja fotoluminestsents-sondid proteiinkinaaside PKA ja PIM in vitro uuringuteks

Väitekirja elektrooniline versioon ei sisalda publikatsiooneProteiinkinaasid (PK-d) katalüüsivad valkude fosforüülimist. PK-de ebanormaalne aktiivsus rakkudes on korrelatsioonis keeruliste haigustega. Seetõttu teeb farmaatsiatööstus märkimisväärseid jõupingutusi, et reguleerida PK-de aktiivsust inhibiitoritega ja jälgida nende aktiivsust luminestsents-sondidega. Käesolevas töös kasutatud ARC-inhibiitorid on keemiliselt struktuurilt adenosiini matkivate heteroaromaatsete fragmentide ja peptiidide analoogide konjugaadid, neid ühendeid on pikemalt uuritud Tartu Ülikooli keemia instituudis. Käesolevas uuringus näidati, et PK PKA katalüütilise alaühiku α-isovormi (PKAcα) monoklonaalse antikeha (kloon D38C6) seondumine sihtvalguga on konkurentne ARC-Lum(Fluo) sondiga ja see antikeha inhibeerib substraadi fosforüülimist. Proovi järjestikust töötlemist nende konkureerivate PKAcα ligandidega kasutati tundliku AbARC immuunanalüüsi-meetodi väljatöötamiseks, mis võimaldas määrata väikseid koguseid (alates 93 pg) PKAcα rakulüsaatides. Hiljuti avastati Cushingi sündroomiga patsiendil S54L mutatsiooniga PRKACB geen. See mutatsioon viib PK glütsiinirikka aasa struktuuri muutumiseni. Käesolevas uuringus konstrueeriti muteerunud PK suhtes kuuekordse selektiivsusega inhibiitor. Lisaks töötati välja luminestsents-meetod PKAcβ-valgu kaubanduslike ja väljatöötatud inhibiitorite afiinsuse määramiseks. Koostöös Oxfordi ülikooliga viidi läbi ARC-inhibiitorite ja proteiinkinaasi PIM-1 komplekside röntgenstruktuuranalüüs. Saadud struktuurimudelitest lähtuvalt konstrueeriti lihtsustatud keemilise ehitusega ained. Uued inhibiitorid derivatiseeriti biotiiniga või fluorestsentsvärviga Cy5 ja neid aineid kasutati PIM-kinaasidetuvastamiseks biokeemilistes lahustes ja bioloogilistes proovides. Analüüsimeetod, milles kasutati ARC-sonde koos PIM-2-selektiivse antikehaga , võimaldas määrata sihtvalgu väikseid koguseid (alates 44 pg PIM-2). Konfokaalmikroskoopia abil tuvastati, et uued fluorestsents-sondid tungivad kiiresti U2OS-rakkudesse, kus nende paiknemine kattub PIM-1 ja fluorestsentsvalgu konjugaadi paiknemisega.Protein kinases (PKs) catalyze the phosphorylation of proteins. Abnormal activity of PKs in cells is correlated to complex diseases. Therefore, the pharma industry is making significant efforts to regulate the activity of PKs with inhibitors and to monitor the activity of PKs with luminescent probes. ARC inhibitors are conjugates of adenosine analogues and peptide mimetic moieties; they have been studied at length at the Institute of Chemistry of the University of Tartu. In the present study, it was shown that the binding of monoclonal antibody (clone D38C6) to α-isoform of the catalytic subunit of PKA (PKAcα) was competitive with binding of ARC-Lum(Fluo) probes. Sequential treatment of a sample with these competing PKAcα ligands was used to develop a sensitive AbARC immunoassay that allowed the determination of small amounts (from 93 pg) of PKAcα in cell lysates. Recently, PRKACB gene with the S54L mutation was discovered in a patient with the Cushing's syndrome. This mutation leads to a change in the structure of the glycine-rich loop of the PK. In the present study, an inhibitor with six-fold selectivity for the mutated PK was developed. In addition, a luminescence method was worked out for determination of affinity of both commercial and developed inhibitors of the PKAcβ protein. X-ray structure analysis of complexes of ARC inhibitors and PK PIM-1 was performed in collaboration with the University of Oxford. Based on the obtained structural models, compounds with simplified chemical structures were constructed. New inhibitors were derivatized with biotin or fluorescent dye Cy5 and applied for the detection of PIM PKs in biochemical solutions and complex biological samples. The sandwich assay utilizing a PIM-2-selective detection antibody featured a low limit of quantification (44 pg of PIM-2). A confocal microscopy study showed that the fluorescent probes were efficiently taken up by U2OS cells and the probes revealed high extent of co-localization with PIM-1-fused fluorescent proteins.https://www.ester.ee/record=b545989

Engineering the surface properties of a human monoclonal antibody prevents self-association and rapid clearance in vivo

Uncontrolled self-association is a major challenge in the exploitation of proteins as therapeutics. Here we describe the development of a structural proteomics approach to identify the amino acids responsible for aberrant self-association of monoclonal antibodies and the design of a variant with reduced aggregation and increased serum persistence in vivo. We show that the human monoclonal antibody, MEDI1912, selected against nerve growth factor binds with picomolar affinity, but undergoes reversible self-association and has a poor pharmacokinetic profile in both rat and cynomolgus monkeys. Using hydrogen/deuterium exchange and cross-linking-mass spectrometry we map the residues responsible for self-association of MEDI1912 and show that disruption of the self-interaction interface by three mutations enhances its biophysical properties and serum persistence, whilst maintaining high affinity and potency. Immunohistochemistry suggests that this is achieved via reduction of non-specific tissue binding. The strategy developed represents a powerful and generic approach to improve the properties of therapeutic proteins

Metal-Organic Frameworks as Templates for Highly Active Heterogeneous Catalysts

Metal-organic frameworks (MOFs) are a class of porous materials, formed by inorganic nodes coordinated by organic linkers. MOFs have been extensively studied for applications in gas absorption, molecular separation, and catalysis. Recently, MOFs have been demonstrated to be excellent templates for functional materials. This work explores the use of MOFs as sacrificial templates to synthesise high performing catalysts and investigates the templating process. Chapter 1 introduces MOFs and the advantages of their use as templates for the synthesis of functional materials, supported by examples of reported MOF-templated materials. The limited application of reducing atmosphere in MOF-templating and the lack of understanding of the templating mechanism are identified as opportunities of contribution to the field. In addition, the relevance of catalysts for renewable H2 conversion into methane and ammonia is discussed. Lastly, high-throughput experimentation and powder X-ray diffraction are presented as tools for catalyst investigation. Chapter 2 describes a systematic study of a manganese-based MOF and two postsynthetically metalated versions of the MOF with rhodium. The MOFs were used as precursors for CO₂ hydrogenation catalysts. The transformation of the MOFs into the active catalysts occurred under reactive conditions (80% H₂/CO₂). The structure of the MOF-templated catalysts and partially decomposed samples were characterized using a range of techniques (powder X-ray diffraction, electron microscopy, and X-ray photoelectron spectroscopy). Rh was demonstrated to assist in the templating process by decomposing the organic components of the MOF to form a mesh of Rh⁰ nanoparticles and MnO or MnCO₃ crystals, dependent on the metalation conditions. Chapter 3 presents a highly active CO₂ methanation catalyst derived from a Ruimpregnated zirconium MOF. In this case, after decomposition under reducing conditions (80% H₂ and 20% CO₂, at 4 bar and 350 °C), the MOF-templated catalyst was composed of Ru⁰ nanoparticles evenly distributed on nano-ZrO₂ crystals. This catalyst displayed remarkable activity, with H₂ conversions of 96% and CH₄ selectivity of 99% and outperformed all tested controls, including a commercial benchmark (10 to 30% Ni/SiO₂) and samples with the same chemical composition. The structure achieved by the MOF-templating method underpined the high activity and was characterized using powder X-ray diffraction, electron microscopy and X-ray photoelectron spectroscopy. Chapter 4 investigates how different Ru/Zr-MOF components affect the catalytic performance and final structure of the MOF-templated catalysts. In this study different organic linkers, active metals and node metal were evaluated for CO₂ methanation. In addition, in operando powder X-ray diffraction experiments clarified the phase transition during the MOF-templating of the active catalyst. Lastly, chapter 5 extends the concept of the MOF-templating method used in Chapter 3 and 4 to a different reaction, NH₃ synthesis. A cerium MOF impregnated with ruthenium was used as catalyst precursor. The unpromoted catalyst displayed high activity at low pressures (30 and 50 bar), outperforming the tested controls. The structure was found to be composed of Ru⁰ nanoparticles evenly distributed on nano-CeO₂ crystals. This synthesis route was shown to provide the catalysts with high activity by controlling the active metal distribution and final morphology.Thesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 201

Sustainable Solution For Plastic Waste Management And Education Campaigns To Mitigate Plastic Consumption And Foster Behavior Change

The issue of plastic waste has become a significant environmental concern in contemporary times. Given the escalating rates of plastic production and consumption worldwide, an urgent need is to implement effective strategies to manage plastic waste. This article aims to investigate sustainable strategies for managing plastic waste through an analysis of existing research and exemplary approaches in the domain. This research assesses diverse methodologies, such as recycling, waste minimization, biodegradable substitutes, and policy interventions, and appraises their efficacy, obstacles, and prospects for enduring sustainability. The results of this research emphasize the significance of inclusive and cohesive approaches that engage various actors in addressing plastic pollution and attaining a more environmentally sound tomorrow