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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
361

Aroma Analysis of Whole Wheat Bread: Impact of Enzymatic Lipid Oxidation and Identification of Drivers of Liking

Pham, Theresa Nguyet 27 September 2022 (has links)
No description available.
362

FATTY ACID PROFILES OF NUTRTION SOURCES AND PLASMA IN PRETERM INFANTS

Choi, A-Rum January 2016 (has links)
Preterm infants are not able to tolerate full enteral feeding of breast milk due to gut immaturity. To fill this nutritional gap, parenteral nutrition is introduced while enteral feeding is gradually increased. Of parenteral nutrition, lipid emulsions supply energy, essential and polyunsaturated fatty acids, which significantly affect short- and long-term health outcomes of growth, visual-and neuro-development for preterm infants. However, elevated plasma triglyceride (TG) levels in preterm infants receiving lipid emulsions have been observed despite less lipid intake compared to breast milk fed infants. We hypothesized that unbalanced fatty acid profiles in lipid emulsion was one factor to cause high plasma TGs for preterm infants. In the multi-center, observational, prospective study, the following samples were analyzed using GC-MS: (1) lipid emulsions (n=5) and breast milk (n=112), (2) plasma (n=294) including normal TG (n=116) and high TG (n=88). Lipoproteins in normal TG (n=18) and high TG (n=24) plasma were measured using gel electrophoresis. Fatty acid profiles in lipid emulsions differed from ones in breast milk. Plasma fatty acid profiles were related to dietary fatty acid intake. Accumulation of all fatty acids except C20:5n3 and relatively high (LDL+VLDL) levels (p<0.001) resulted in high TG plasma compared to normal TG plasma. Overall, this study supports the hypothesis that nutrition of lipid emulsions was associated high TG with differences in fatty acid uptake but it is still unclear if the imbalance of fatty acids directly causes high TG. More research is necessary to investigate other factors such as enzyme activity, lipid clearance rate, or different rate of fatty acid metabolism. / Thesis / Master of Science (MSc)
363

Phytochemical and biological strategies to improve essential oils content in lavender

AL-Garallaa, Keefah 06 August 2021 (has links)
Lavender is an important medicinal plant that is sensitive to various environmental factors. Lavender essential oils have been shown to improve human health in response to many diseases. Lavender is grown all over the world, which indicates its ability to adapt to different climates. There are no reports of its commercial cultivation in Mississippi. It has been proven that there are many factors that directly affect the plant growth and concentration of essential oils in lavender. Studying these factors that affect plant growth and essential oils will be beneficial for lavender producers. The aim of this study is to increase the production of essential oil through cultural techniques and analyze the active compounds of three Lavandula species (L. intermedia, L. angustifolia, L. stoechas) using HPLC (High performance liquid chromatography) and GC-MS (Gas Chromatography, Mass spectrometer) technology. Applications of gibberellic acid, iron chelate, Mycorrhizae, humic acid, DAP, and potash fertilizer were studied to promote plant growth and production of essential oils. The essential oils were extracted using a Soxhlet distillation. The quantity and quality of the essential oils was also evaluated using HPLC and GC-MS. The linalool, linalyl acetate, and other compounds from Lavandula may be considered natural raw material source for pharmaceuticals and cosmetic products. These vital components of the essential oil of lavender leaves, flowers, and stems (linalool, linalyl, and other compounds) were affected by chelated iron treatments, gibberellin, humic acid, and mycorrhizae. The essential oil compounds of L. angustifolia and L. x intermedia cultivars make them worth cultivating.
364

MASS SPECTROMETRY-BASED HIGH THROUGHPUT APPROACH FOR IDENTIFICATION OF MOLECULAR MODIFICATION OF OXIDATIVE PROCESS IN RESPIRATORY

Song, Wei 21 November 2008 (has links)
No description available.
365

Method Development for the Collection and Instrumental Analysis of Harmful Compounds in Mainstream Hookah Smoke

Clutterbuck, Amberlie A. 26 May 2017 (has links)
No description available.
366

Analysis of Regulated Drugs Using Chromatographic and Spectrophotometric Techniques Coupled with Spectroscopy An Orthogonal Approach to Protecting Public Health

Nickum, Elisa A. 30 October 2017 (has links)
No description available.
367

Beneficial Use of Wastes: Petroleum-Contaminated Sediment and Coal Refuse

Sasivongpakdi, Adison 06 December 2010 (has links)
No description available.
368

Functional evolution of R2R3 MYB transcription factors in the grasses

Dias, Anusha P. 03 February 2004 (has links)
No description available.
369

Pharmacokinetics, in vitro absorption and metabolism of perillyl alcohol, a chemopreventive and chemotherapeutic agent

O'Brien, Zhihong Zhang 03 March 2004 (has links)
No description available.
370

Solid-Phase Microextraction of Volatile Organic Compounds for Analytical and Forensic Applications

Kymeri E Davis (6989576) 03 January 2024 (has links)
<p dir="ltr">Gas chromatography-mass spectrometry (GC-MS) is a frequently used technique in forensic chemistry for the identification of controlled substances and explosives. GC-MS can be coupled with solid-phase microextraction (SPME), in which a fiber with a sorptive coating is placed into the headspace above a sample or directly immersed in a liquid sample. Analytes are adsorbed onto the fiber which is then placed inside the heated GC inlet for desorption.</p><p dir="ltr">Illicit drugs are often found in the form of impure solids, mixed with other drugs, adulterants, and diluents. A simple method for the quick identification of drugs including methamphetamine, cocaine, heroin, fentanyl, and pharmaceutical tablets was developed. Headspace SPME methods were utilized with an elevated extraction temperature for the detection of various drugs in powder and tablet form. An extraction temperature of 120°C was used to encourage analytes into the headspace of the vial. A sample of the solid drug was placed in a headspace vial with no prior sample preparation or clean-up. This vial was then heated inside of an agitator where the sample was extracted. It was found that drugs in solid and tablet form can be detected using this high temperature headspace SPME method at the temperature of 120°C with no prior sample preparation. This method is simple, efficient, and cost effective for the detection of legal and illicit drugs in solid form.</p><p dir="ltr">Headspace SPME may also be used for the analysis of explosive materials. Canines trained at detecting hidden explosives should be trained using real explosive materials that have minimal contamination by other explosive odors to ensure accurate identification of potential threats. Therefore, the potential for cross-contamination between training aids is of importance. There are various storage methods in use by canine handlers such as plastic and cloth bags, but these can lead to cross-contamination between training aids during storage. Alternatively, odor-permeable membrane devices (OPMDs) may store training aides and be used as a delivery device. A membrane in the OPMD allows for volatile compounds from the training aids to be released during training while helping to prevent contaminants from entering the device. OPMDs were used in addition to traditional storage containers to monitor the contamination and degradation of 14 explosives used as canine training aids. Samples included explosives that contain highly volatile compounds like dynamite and explosives with less volatile compounds like RDX. Explosives were stored individually using traditional storage bags or inside of an OPMD at two locations, IUPUI and an Indianapolis Metropolitan Police Department. The police department actively used the training aids during canine trainings. Samples from each storage type at both locations were collected at 0, 3, 6, and 9 months and analyzed using Fourier transform infrared (FTIR) spectroscopy and GC-MS with SPME. FTIR analyses showed no signs of degradation of the training aids from any timepoint or location. GC-MS identified cross-contamination from ethylene glycol dinitrate and/or 2,3-dimethyl-2,3-dinitrobutane across almost all samples regardless of storage condition. The contamination was found to be higher among training aids that were stored in traditional ways and were in active use by canine teams. Additionally, Time 0 had the highest level of contamination, indicating that explosive training aids are received from the vendors with initial cross-contamination.</p><p dir="ltr">To test the initial cross-contamination levels of training aids, 11 explosive materials were ordered from three different vendors. A 1-gram sample of each was collected and analyzed using SPME with GC-MS. In several cases, explosive materials that are commercially available already exhibit elevated levels of contamination. This indicates that training aids must be acquiring contamination during manufacturing and/or storage at the vendor facility. The cross-contamination of explosive canine training aids stored in OPMDs was further evaluated and compared to traditional storage methods. This was done by storing various combinations of storage containers such as cloth bags, velcro bags, and OPMDs along with explosives and using activated charcoal strips to collect the volatile compounds such as 2,3-dimethyl-2,3-dinitrobutane and ethylene glycol dinitrate. Only one type of storage container, a velcro bag, showed evidence of contamination, indicating that OPMDs may not further prevent cross-contamination of explosive training aids.</p>

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