The role of 2-arachidonoylglycerol (2-AG) in nausea and vomiting was evaluated using a shrew (Suncus murinus) model of emesis and nausea-like behavior in rats, conditioned gaping. Shrews received JZL184, a selective MAGL inhibitor, prior to treatment with emetogenic lithium chloride (LiCl). The potential of exogenously administered 2-AG and arachidonic acid (AA) to regulate conditioned gaping was assessed in rats. The role of cannabinoid receptors and cyclooxygenase (COX) inhibition in suppression of vomiting and conditioned gaping was also evaluated. JZL184 dose-dependently suppressed vomiting in shrews, and was shown to inhibit MAGL in shrew brain tissue. The anti-emetic effects of JZL184 were prevented by the CB1 antagonist, AM251. Exogenous 2-AG suppressed LiCl-induced conditioned gaping, but was not prevented by AM251 or the CB2 antagonist, AM630. Instead, the COX inhibitor, indomethacin, prevented the suppressive effects of 2-AG, as well as AA. These results suggest that manipulations that elevate 2-AG may have anti-emetic/anti-nausea potential. / This research was supported by research grants from the Natural Sciences and Engineering Research Council of Canada (NSERC 92057) to Linda Parker, the Israel Science Foundation (DA009789) to Raphael Mechoulam, and the National Institutes of Health (DA009789, DA017259) to Benjamin Cravatt.

The significant role that nitric oxide plays in human physiology is linked to the ability of NO to bind to iron forming mono-nitrosyl iron complexes. Protein-bound and low-molecular-weight dinitrosyl iron complexes (DNICs) are known to form in excess NO. Studies of such biological DNICs have relied on their paramagnetism and characteristic EPR signal of g value of 2.03. It has been suggested that DNICs act in vivo as NO storage (when protein-bound) and transfer agents (when released by, for example, free cysteine). Biological DNICs, mainly resulting from iron-sulfur cluster degradation, are difficult to extract and isolate, thereby preventing their full characterization. Thus, development of synthetic DNICs is a promising approach to model and better understand the formation and function of biological DNICs, the scope of donor ligands that might coexist with Fe(NO)2 units, the redox levels of bio-DNICs, and establish other spectroscopic techniques appropriate for characterization. A series of N-heterocyclic carbene (NHC) and imidazole (Imid) complexes has been characterized as mimics of histidine-containing DNICs. The pseudo-tetrahedral L2Fe(NO)2 complexes have NO stretching frequencies and redox potentials that suggest the NHCs are slightly better donors than Imids, however the two types of ligands have similar steric properties. Both the EPR-active, {Fe(NO)2}9 and the EPR-silent, {Fe(NO)2}10 states can be accessed and stabilized by the NHC. Nitric oxide transfer studies have shown that only the {Fe(NO)2}9 complexes are capable of transferring NO to a suitable NO trapping agent. Deprotonation of the distal nitrogen functionality in the imidazolate ligands of [(Imidazole)2Fe(NO)2]- leads to aggregation forming molecular squares of {Fe(NO)2}9 units bridged by the imidazolates. These interesting tetrameric complexes are examined by X-ray diffraction, EPR, and Mössbauer studies. The paramagnetic tetrameric complexes have multiple redox events observed by cyclic voltammetry. Mössbauer spectral data of the tetrameric complexes are compared with Mössbauer data obtained for a series of NHC-containing DNICs. Iron and cobalt-containing mononitrosyl N2S2 model complexes of the nitrile hydratase enzyme active site demonstrate sulfur-based reactivity resulting in the formation of polymetallic complexes. In all cases, shifts in the nitrosyl stretching frequencies demonstrate substantial transfer of electron density from the (NO)M(N2S2) moiety to the metal-acceptor site.

This study examined the emotional and physiological differences between masticatory muscle pain patients and age, height, and weight matched pain-free controls. Physiological activation and emotional reactivity were assessed in the 22 muscle pain patients and 23 pain-free controls during a baseline rest period, while discussing a personally relevant stressor, and during a post-stressor recovery period. Physiological activity was assessed through the use of the frequency domain heart rate variability indices. Activity in the high frequency heart rate variability range is an index of parasympathetic activity while activity in the low frequency heart rate variability range is an index of both sympathetic and parasympathetic activity (Akselrod, 1981). The muscle pain patients showed significantly more physiological activation during both the baseline rest and the post-stressor recovery periods. These physiological differences were quantified by higher low frequency heart rate variability and lower high frequency heart rate variability during these study periods. This pattern of higher activation was also present in the report of emotional reactivity in the muscle pain patients. The emotional and physiological differences between the groups across study periods were more pronounced in muscle pain patients who reported a traumatic life experience. These results provide evidence of physiological activation and emotional responding in masticatory muscle pain patients that differentiates them from matched pain-free controls. The use of HRV indices to measure physiological functioning quantifies the degree of sympathetic and parasympathetic activation. Study results suggest the use of these HRV indices will improve understanding of the role that excitatory and inhibitory mechanisms play in the onset and maintenance of chronic masticatory muscle pain conditions.

According to IPCC reports, the greenhouse gas CO2 is responsible for global climate change. Studies show that CO2 concentration reached a level of 400 ppm in 2013, or 40 % above pre-industrial levels. The contribution of CO2 from industrial activity to increasing global CO2 concentrations is widely accepted and points to the need to reduce the emission of this greenhouse gas.One possible combustion technology that shows promise for reducing CO2 emissions is chemical looping combustion (CLC). It is an oxy-fuel technology, but has the advantages of in situ oxygen separation, low NOx emissions and low cost of CO2 emission abatement; it entails the use of an oxygen carrier (OC) to provide oxygen for combusting fuels. OC development is an important task in CLC. Iron based OCs have attracted most research attention in recent years, mainly due to their inexpensive and non-toxic nature. Bi-metal oxide OCs usually impart better CLC performance than mono-metal oxide OCs, one example of which is the introduction of CeO2 as a partially reducible material capable of generating oxygen vacancies that lead to oxygen storage and transfer. In this study, CeO2 was used as an additive to a Fe2O3-based OC and its effect on physical properties, such as morphology, surface area and mechanical strength, was analyzed in detail. The reactivity of OCs is studied using TGA-MS and a bench scale CLC setup. The results show that the reduction reaction at the surface is independent of whether CeO2 is present or not, but after the surface oxygen had been consumed, the OC with CeO2 provided faster oxygen transfer rates from the bulk to the surface to produce better average reaction rates. The OCs after reduction and oxidation were analyzed using XRD and Raman spectroscopy; based on these analytical data, a model for the promoting role of CeO2 is discussed. Furthermore, the reaction kinetics of the OCs were also studied using shrinking core model, the kinetics parameters were obtained and compared. Scale-up of laboratory-scale CLC reactors is another important task necessary to develop an understanding of the potential and efficiencies of CLC. In this study, scaling laws were used as a guide to design and then build two different-sized CLC reactors. Testing of the reactors involved a focus on chemical similarities. Comparisons of the performance of both reactors showed good consistency, thereby validating the scale modeling method and the scale laws for CLC reactors.

<p>Substance use disorders are one of the most common psychiatric diagnoses among adolescents; marijuana is the illicit drug used most frequently by youth. Treatment dropout and relapse following treatment are common; innovative strategies are needed to improve treatment outcomes for youth substance abusers. The aim of this study was to develop and evaluate the feasibility of a virtual reality (VR) cue reactivity paradigm for adolescent cannabis abusers and to compare it to a video cue reactivity paradigm. Forty-two treatment-seeking youth with a cannabis use disorder completed the study, which incorporated three parts. During Part 1, drug and neutral video clips were shown to 11 youth and five substance-abuse experts who provided craving/usefulness ratings for each video clip. During Part 2, five youth met in a focus group and then individually to provide input on the development of the VR paradigm. During Part 3, 26 youth completed a laboratory procedure involving neutral and drug-related video clips and VR presentations. Heart rate, skin conductance, and skin temperature were measured as well as craving. Higher levels of craving and skin conductance were observed during drug-related presentations. The presentations did not significantly differ in their ability to elicit craving and arousal. Results suggest that youth can experience subjective and physiological reactivity to VR drug cues warranting further study with a larger, more diverse sample. Implications are discussed.</p> / Dissertation

The kinetic substitution reactions of two different sets of mononuclear Platinum(II) complexes with heterocyclic bio-relevant azole nucleophiles, viz. Imidazole (Im), 1-methylimidazole (MIm), 1,2-Dimethylimidazole (DIm), 1,2,4-triazole (Trz) and pyrazole (Pyz). All substitution reactions were studied under pseudo-first order conditions as a function of the incoming nucleophiles concentration and temperature using stopped-flow techniques and UV/Visible spectroscopy. The first set of complexes included the tridentate polypyridine complexes, Pt(II)(2,2:6,2″-terpyridine)Cl]Cl.2H2O, (PtL1) Pt(II)(1,3-di(2-pyridyl)benzene)Cl, (PtL2) Pt(II)(2,6-di-(2’-quinolinyl)pyridine)Cl](Cl), (PtL3) and Pt(II)(1,3-di-(2’-quinolinyl)benzene)Cl (PtL4). The substitution of these complexes with the previously mentioned azoles showed that tuning electronic communication of the Pt(II) centre towards substitution through quinoline moieties has an opposed effect to that obtained through pyridine moieties, and verified that the trans-effect of a phenyl ring is much greater than that of a pyridine ring. The reactivity trend among the complexes was PtL2 > PtL4 > PtL1 > PtL3. Once the nucleophiles were categorised into two groups based on their structural similarities, reactivity trend observed amongst the nucleophiles was generally Im > Pyz > Trz, based on the basicity (electronic effects) and MIm > Im > DIm based on steric effects. The second series of complexes were tridentate [Pt(bis(2-pyridylmethyl)amine)OH2](ClO4)2, Ptdpa and [Pt(bis(2-pyridylmethyl)sulfide)OH2](ClO4)2, Ptdps of which the kinetics were studies in an aqua medium and at constant ionic strength (0.1 M). Ptdps was found to be more reactive (three magnitude higher) than Ptdpa. The rate of substitution of the aqua ligand is dependent on the strength of the σ-donor character and the π-acceptability of the atom situated trans to the leaving group. The observed reactivity for the azoles followed the trend, MIm > Im > DIm > Trz > Pyz. This reactivity trend is in accordance with the basicity, and reflects steric and electrophilic effects of the nucleophiles. This was supported by DFT calculations and the X-ray crystal structure of Ptdps_Cl. For all substitution reactions, the temperature dependent studies showed an associative activation. It is envisaged that the findings of this project will provide useful information for designing new drugs as part of a protracted search of effective anticancer drugs with a wider spectrum. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2014.

Nuclear reactions induced by neutrons, protons and alpha particles on copper isotopes are being studied in an effort to understand the nucleosynthesis of elements in stars, specifically, the p-process. The p-process occurs toward the end of a star's life and produces those elements which have a high proton to neutron ratio, which are heavier than iron. Little is known about the nature of the p-process-inside stars. Isotopes of copper are studied since they are close in mass number to iron, which has the highest nuclear binding energy. Nuclear cross sections will be calculated for copper, as well as S-factors, which are important from an astrophysical point of view. These values are needed to calculate reaction rates which are the main ingredients for understanding nucleosynthesis. / Department of Physics and Astronomy

SANTRAUKA Serologinių sifilio ir Laimo boreliozės reakcijų kryžminis reaktyvumas Darbo autorė: Tatjana Subočiūtė Darbo vadovas: med. m. dr. Andrius Vagoras Darbo tikslas: nustatyti VULSK diagnostikos centre rutiniškai naudojamų serologinių sifilio ir Laimo boreliozės testų galimai klaidingai teigiamų rezultatų dažnumą dėl kryžminio viena iš šių infekcijų užsikrėtusiųjų pacientų kraujo serumų reaktyvumo. Darbo metodai: Tyrimai buvo atlikti Vilniaus universiteto ligoninės Santariškių klinikos (VULSK) Laboratorinės diagnostikos centro Mikrobiologijos laboratorijos Infekcijų žymenų tyrimų padalinyje. Serumai buvo surinkti ir ištirti nuo 2005 m. vasario iki 2006 m. kovo mėn. Tyrimo medžiagą sudarė 40 serumų. 23 serumai dėl sifilio tyrimų buvo gauti iš VULSK Dermatovenerologijos centro. 8 serumai dėl Laimo ligos tyrimų buvo gauti iš VULSK Dermatovenerologijos centro. UAB „Endemik” atrinkti 9 serumai ištirti dėl Laimo ligos. Visi į tyrimą įtraukti serumai buvo ištirti šiomis reakcijomis: 1) RPR su titru, 2) TPHA, 3) Treponema pallidum ELISA, 4) Treponema pallidum imunofluorescencija, 5) Borrelia burgdorferi imunofluorescencija. Tyrimo rezultatai: Ištyrus penkiomis reakcijomis serumus (RPR, TPHA, Treponema pallidum IFR, Treponema pallidum IFA bei Borrelia burgdorferi IFR), buvo pastebėtas kryžminis serologinis reaktyvumas tarp Borrelia burgdorferi IFR ir Treponema pallidum IFR reakcijų. Mūsų darbo duomenimis, tiriant 17 serumų (teigiamus dėl Laimo ligos) kryžminis reaktyvumas... [toliau žr. visą tekstą] / SUMMARY Cross - reactivity in serological test for Lyme disease and syphilis Author: Tatjana Subočiūtė Supervisor: Andrius Vagoras, MD Work purpose: to determine the incidence of possibly false positive results of serological syphilis and Lyme borreliosis tests, routinely used in VULSK Diagnostics centre, occurring because of cross reactivity of patients, having one of these disease, blood. Work methods: the research was carried out in Vilnius University Hospital Santariškių Klinikos (VULSK) Infection Markers Research Department of Microbiological Laboratory in Laboratory Diagnostics Centre. Serum samples were collected and tested from February, 2005, till March, 2006. The investigation material was composed of 40 serum samples. 23 serum samples for syphilis test came from VULSK Centre of Dermatovenereology. 8 serum samples for Lyme borreliosis test were received from VULSK Centre of Dermatovenereology. 9 serum samples for Lyme borreliosis test were picked by UAB “Endemik”. All the samples, included into the research, were tested by following reactions: 1) RPR with titer, 2) TPHA, 3) Treponema pallidum ELISA, 4) Treponema pallidum immunofluorescence, 5) Borrelia burgdorferi immunofluorescence. Research results: After testing the serums by five reactions (PRP, TPHA, Treponema pallidum FTA – ABS, Treponema pallidum ELISA and Borrelia burgdorferi immunofluorescence), a serological cross reactivity between Borrelia burgdorferi immunofluorescence and Treponema pallidum FTA - ABS... [to full text]

It is recognised that the reactions with steam and CO2 are the rate limiting step during coal gasification, and a vast number of studies has been dedicated to the kinetics of these reactions. Most studies were carried out by using a single reactant (CO2 or H2O), either pure or diluted with an inert gas. Research using gas mixtures of CO2 and steam and their effects on gasification kinetics have been undertaken but are limited. The objective of this study is to determine the effects of CO2 on the steam gasification rate of a typical Highveld seam 4 coal. The South African medium ranked high volatile bituminous coal was charred at 950 °C. 2.0 g samples of ± 1 mm particles were analysed in a modified large particle thermo gravimetric analyser under various reactant gas concentrations. Experiments were conducted at atmospheric pressure (87.5 kPa) and temperatures from 775 to 900 °C, such that the conversion rate was controlled by chemical reaction. Reagent mixtures of steam-N2, steam-CO2 and CO2-N2 at concentrations of 25-75 mol%, 50-50 mol%, 75-25 mol% and 100 mol% were investigated. Arrhenius plots for steam and CO2 gasification produced activation energy values of 225 ± 23 kJ/mol and 243 ± 32 kJ/mol respectively. The calculated reaction orders with respect to reagent partial pressure were 0.44 ± 0.08 and 0.56 ± 0.07 for steam and CO2 respectively. Comparisons of the experimental data showed a higher reaction rate for the steam-CO2 mixtures compared to steam-N2 experiments. The semi empirical Wen model (m = 0.85) with an additive Langmuir-Hinshelwood styled rate equation predicted the mixed reagent gasification accurately. Reaction constants that were determined from the pure reactant experiments could directly be applied to predict the results for the experiments with mixtures of steam and CO2. The conclusion was made that under the investigated conditions steam and CO2 reacts simultaneously on different active sites on the char surface. / Thesis (MIng (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013.

It is recognised that the reactions with steam and CO2 are the rate limiting step during coal gasification, and a vast number of studies has been dedicated to the kinetics of these reactions. Most studies were carried out by using a single reactant (CO2 or H2O), either pure or diluted with an inert gas. Research using gas mixtures of CO2 and steam and their effects on gasification kinetics have been undertaken but are limited. The objective of this study is to determine the effects of CO2 on the steam gasification rate of a typical Highveld seam 4 coal. The South African medium ranked high volatile bituminous coal was charred at 950 °C. 2.0 g samples of ± 1 mm particles were analysed in a modified large particle thermo gravimetric analyser under various reactant gas concentrations. Experiments were conducted at atmospheric pressure (87.5 kPa) and temperatures from 775 to 900 °C, such that the conversion rate was controlled by chemical reaction. Reagent mixtures of steam-N2, steam-CO2 and CO2-N2 at concentrations of 25-75 mol%, 50-50 mol%, 75-25 mol% and 100 mol% were investigated. Arrhenius plots for steam and CO2 gasification produced activation energy values of 225 ± 23 kJ/mol and 243 ± 32 kJ/mol respectively. The calculated reaction orders with respect to reagent partial pressure were 0.44 ± 0.08 and 0.56 ± 0.07 for steam and CO2 respectively. Comparisons of the experimental data showed a higher reaction rate for the steam-CO2 mixtures compared to steam-N2 experiments. The semi empirical Wen model (m = 0.85) with an additive Langmuir-Hinshelwood styled rate equation predicted the mixed reagent gasification accurately. Reaction constants that were determined from the pure reactant experiments could directly be applied to predict the results for the experiments with mixtures of steam and CO2. The conclusion was made that under the investigated conditions steam and CO2 reacts simultaneously on different active sites on the char surface. / Thesis (MIng (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013.