The FAME yield from microalgae of two in situ transesterification methods were compared to a typical Folch et al. (1957) extraction followed by transesterification using the Hilditch et al. (1964) procedure. A method based on Park & Goins (1994), utilizing 0.5 N NaOH in methanol, then 14 % BCl3 in methanol, was found to be superior to a method based on Lepage & Roy (1986), utilizing acetyl chloride in methanol. The Park & Goins (1994) method was equivalent to the traditional method and was, therefore, selected for further study. In establishing the parameters of the method, water contents up to 0.55 mL were not found to inhibit the reaction within the maximum lipid load, conservatively assessed at ~1 mg. The reaction time and temperature required to produce a maximum FAME yield was 10 min at 90 °C for the BCl3-catalyzed reaction, while the NaOH-catalyzed reaction happened instantaneously at ambient temperature.

Every year, more than a million people are diagnosed with colorectal cancer (CRC) that develops in the large intestine. It is one of the most studied cancers in the world but still more knowledge about how this cancer develops and acts is needed in order to use more effective ways to treat CRC. Autophagy is a vital mechanism in cells that is also suggested to maintain cancer cell survival. In normal cells, it plays an important role by removing damaged cells and organelles as well as eliminating pathogens. Under metabolic stress this mechanism is induced to provide enough nutrients and energy for the cell to survive. Cancer cells are exposed to greater environmental stress than normal cells and therefore, cancer cells exhibit higher levels of autophagy suggesting it to be a crucial mechanism for their survival. Gaining a deeper understanding of this essential mechanism and its activation might provide new insights and improved treatments for the fight against colorectal cancer. In situ Proximity Ligation Assay (PLA) is a protein detection method that enables sensitive and specific detection of proteins and protein-protein interactions (PPIs) in cell lines and tissue samples. The method uses simultaneous recognition of two independent antigens on a protein or protein complex together with a rolling circle amplification (RCA) to form a rolling circle product (RCP) on top of the target. By using fluorescent oligonucleotides, RCP can be visualized and is seen as a bright spot that enables sensitive detection of the target at single-molecule resolution. The aim of this study was to develop assays to detect endogenous molecular events known to be biomarkers of autophagy in situ in order to study autophagy mechanism in CRC patient samples. We focused our research on two PPIs that were known to interact when autophagy is induced. The first investigated interaction was between microtubule-associated protein 1A/1B- light chain 3 (LC3) and sequestome-1 (SQSTM1), an interaction that occurs during autophagy initiation. The second interaction was between B-cell lymphoma 2 (Bcl-2) and Bcl-2/adenovirus E1B 19-kDa interacting protein 3 (BNIP3) that takes place during hypoxia-induced autophagy. To study whether these PPIs can be used as a detection method to monitor autophagy, we used a well- established cell model based on serum starvation and CoCl2 - an hypoxic mimetic- treatment of the intestinal cancer cell line Caco-2 in comparison to normal culture condition. According to isPLA quantification, detection of both PPIs was distinctly higher in treated cells compared to untreated cells giving promising results and suggesting that they can be potentially used as suitable assays to monitor these biomarkers of autophagy. For development of an improved protein detection method that enables the study of several PPIs simultaneously in a tissue sample (In situ Multiplexing), we conjugated directly a short oligonucleotide strand to the primary antibodies. These formed proximity probes could later be used in in situ for multiplexing.

The purpose of this report was to investigate how the abiotic factors (temperature, pH, nutrients, oxygen levels and water content) would affect the decomposition of oil-contaminated soil and how a variance in structured soil would affect the decomposition-rate. A minor field-study was made and soil where structured in five different ways (one was a default pile and was used as a reference). The study took place over 137 days and three samples were taken (start, middle, end) and analyzed for aromatic and aliphatic compounds. The result of this study shows that there is a significant difference between all methods for the aliphatic compounds and no significant difference for the aromatic compounds. The abiotic factors that affect decomposition vary from organism to organism, depending on what type of environment it will function the best. In this type of environment it could be necessary to change temperature interval, nutrient availability or pH to optimize the conditions for the microorganisms. The conclusion of this report is that the structured of the soil-piles will affect decomposition rate, but it is unsure how much. Further research is needed to conclude how the soil should be structured to maximize the decomposition-rate.

This thesis introduces a new route to control the structure of semiconductor nanowires using surface chemistry. Specifically, in Au-catalyzed Si nanowire growth using hydride species (Si₂H₆) as growth precursors, we demonstrate that the surface hydrogen existing on the nanowires sidewalls affects the growth morphology. First, we show the spectroscopic evidence of atomic hydrogen bonded to sidewall surface of Si nanowires in real-time in situ during growth and correlate their relative change with different growth orientations and planar defect generation. By introducing additional atomic hydrogen during the <111>-oriented nanowire growth with intrinsically low hydrogen concentration, we confirm that the growth orientation changes from <111> to <112> orientation. We also show that the transient change in the nanowire growth conditions (i.e., substrate temperature and precursor pressure) can rationally induce the planar defects such as twin boundary or stacking fault in Si nanowires at user-defined position. These findings provide important insight into the vapor-liquid-solid technique for nanowire growth and identify new possibilities for systematically controlling their structures in general.

Petroleum hydrocarbon (PHC) contamination poses a serious threat to aquifer systems worldwide. Accidental releases of PHCs due to gasoline spills and leakage from underground storage tanks can often result in PHC subsurface contamination. The main compounds of concern associated with gasoline spills are benzene, toluene, ethylbenzene and xylenes (BTEX), trimethylbenzenes (TMBs) and naphthalene, due to their high mobility and potential human health risks. Sodium persulphate is one of the newest oxidants to gain widespread use for in situ chemical oxidation (ISCO), however its effectiveness in treating PHCs is not fully understood. In this study, the ability to use unactivated sodium persulphate as a remediation tool in treating dissolved and residual BTEX contamination was tested during a bench-scale laboratory study and within a pilot-scale field investigation. In both cases unactivated sodium persulphate was used at a concentration of 100 g/L. A laboratory-scale degradation potential batch test was conducted to assess the efficacy of unactivated sodium persulphate to oxidize petroleum hydrocarbon contaminated groundwater in conjunction with aquifer material from a field site. Data from the control reactions indicated that persulphate was stable for the entire 35-day experimental period and that the decrease in PHC concentrations for most of the samples followed a first-order degradation. The behaviour and ability for sodium persulphate to oxidize dissolved and residual BTEX contamination was further evaluated in a controlled pilot scale field study. 200 kg of sodium persulphate was dissolved in 2000 L of water and injected into the subsurface. Electrical conductivity (EC), pH, sodium, persulphate, sulphate and BTEX concentrations were all monitored throughout the 158-day study period. Field research showed that there was a strong correlation between EC and sodium concentrations. Hence, this relationship allowed for real-time EC measurements to be used to effectively predict the extent of the injectate. Based on the calculated aqueous density of sodium persulphate at a concentration of 100g/L, predicted simulation model results and observed tracer field results, density effects were present and played a very important role in the transport of the injectate. The heterogeneous geology of the site also greatly influenced the transport of the injectate. The majority of the injectate appeared to have flowed out of the layers with higher hydraulic conductivity that intersected the upper and lower portion of the injection well’s screen length. The extent of the injected slug in the layers with lower hydraulic conductivity located in the centre portion of the injection well’s screen length was less in comparison. In general, areas with elevated tracer, persulphate and sulphate concentrations, also showed a decrease in BTEX concentration. Four main responses were observed. Group 1 consists of sampling points where tracer levels were elevated along with a corresponding short-term decrease in dissolved BTEX. Group 2 consists of sampling points where elevated tracer levels was observed along with a long-term apparent decrease in dissolved BTEX. Group 3 consists of sampling points where the tracer was elevated however dissolved BTEX levels remained essentially at background levels. And finally, group 4 consists of sampling points where the tracer was not observed to be elevated hence no decrease in dissolved BTEX was observed. Laboratory studies showed that the oxidation of BTEX compounds by unactivated sodium persulphate could be very successful. However, field study results showed that complexities such as heterogeneity of the field site and injectate density effects play a key role in the success of the remediation system.

Pacific Rim International Conference on Advanced Materials and Processing <DA14524950> (5th : 2004 : Beijing, China)

In situ gelled acids that are based on polymers have been used in the field for several years as an acid diversion agent. These acids should not cause permanent formation damage, and should clean-up rapidly and completely when the well is put back on production. However, recent lab studies indicated that a significant amount of gel was retained inside the core even when the recommended breaker concentration was used. This gel significantly reduced the core permeability. Therefore, the objective of this study is to examine the working mechanisms of the solid breaker and the factors that affect the breaking time. The flowback of the spent acid and the core damage induced by it will also be assessed in detail. Viscosity and rheological experimental studies were conducted using polymer-based in situ gelled acids that used Zr as a crosslinker agent. To form the gel, this acid was neutralized using Pink Desert limestone to pH 3.5-4.The rheological properties of the gel were measured under different breaking conditions for 2 hr using HPHT rotational and oscillatory rheometers. Temperature (150 to 250 degrees F), shear rate (0.1 to 1000 s^-1), and breaker concentrations (0 to 32 lb/Mgal) were the main parameters that were investigated in this study. Experimental results showed that there is no need to add more than 16-ppg breaker concentration at 150 degrees F, while 4-ppg breaker concentration is enough at temperatures higher than 200 degrees F. A full breaking of these acids was obtained when the values of elastic modulus (G') were equalized with the viscose modules (G"). An HPHT filter press was used to simulate the flowback of the spent acid. Viscosity measurements of filtered fluids were used to determine the degree of gel degradation. Carbonate cores that had a 2.5 in. diameter and 0.25 in.thickness were used. Temperature (75 to 250 degrees F) and breaker concentrations (0 to 16 lb/Mgal) were the main parameters that were investigated in this study. Experimental results showed that there was always a gel left inside the rock, and such caused permeability reduction. Time needed to flowback the solution decreased by 50% when the temperature was increased from 150 to 200 degrees F, while it decreased by only 30% when the breaker concentration was doubled. At 150 degrees F, 16-ppg breaker concentration was recommended for breaking the gel. At higher temperatures (>150 degrees F), 8-ppg breaker concentration was enough to help degrade the gel.

Errata inserted. / Bibliography: leaves 98-120. / x, 120, [4] leaves, [13] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study is concerned with the identification of genes related to the very early stages of meiosis when homologous pairing occurs. A cDNA library is prepared at the premeiotic interphase and prophase stages of meioses. Differential screening is used to identify and select clones showing preferential expression in anthers at early meiosis. Two selected clones are chosen for further analysis and to investigate a possible role in chromosome pairing. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

Universiẗat, Diss., 2006--Karlsruhe.

Heidelberg, Univ., Diss., 2007.