19 research outputs found
Analysis of Cannabinoids in Post-mortem Blood Samples
This thesis is concerned with the analysis of cannabinoids, delta-9-tetrahydrocannabinol (THC) and its major metabolite, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THCCOOH), in post-mortem blood samples. It concentrates on sample preparation procedures and end-step detection techniques by High Pressure Liquid Chromatography (HPLC) and Gas Chromatography-Mass Spectrometry (GC-MS). A comparative evaluation was made of solid-phase (diatomaceous earth, Extrelut) and solvent extraction procedures. When extracted with hexane, mixtures of hexane and more polar solvents, or acetonitrile, the former gave low extraction yields, for example, with acetonitrile the recoveries were 70.4% for THC and 43.9% for THCCOOH. It was observed that clogging of the extrelut columns by precipitated blood proteins might have resulted in the poor results obtained. On the other hand, solvent extraction procedures using acetonitrile gave better results. Recoveries obtained for THC and THCCOOH were 82.1% and 82.7% respectively. These values were found to be higher when deionised water was added to dilute the blood samples (83.2% for THC and 86.9% for THCCOOH). However, addition of buffers at pH 5.0 and 7.4 did not improve the recoveries obtained by addition of water. Calibration curves of the solvent extraction procedure produced linear plots within the 0-80ng/ml range for both THC and THCCOOH. The solid-phase extraction material Bond Elut Certify II was developed recently for the extraction and purification of cannabinoids from biological matrices. It was incorporated into this study as a clean-up procedure for HPLC analysis of the solvent extracts. Therefore, extraction procedure selected for further analysis involved deproteinization and extraction with acetonitrile, supernatant clean-up using the Bond Elut Certify II columns, evaporation to dryness and either reconstitution of the residue in mobile phase for HPLC analysis or derivatization of the residue prior to GC-MS analysis. For HPLC analysis, acetonitrile-methanol-0. 02N sulphuric acid (65:15:50, v:v:v) was chosen from four mobile phases examined. Detection of analytes was carried out using ultra-violet (UV) and electro-chemical (ECD) detectors at wavelengths 212nm, 220nm and at an applied potential of +1.10V respectively, after detector optimisation procedures. The clean-up procedure separated the cannabinoids into THC and THCCOOH fractions. Thus, two internal standards were needed for quantitation purposes. N-octyl p-hydroxy benzoate and phenylbutazone were found to be the most suitable choices for the two fractions, respectively. It was also observed that the THC fraction gave clean chromatograms while the THCCOOH fraction contained co-extracted interferences which eluted closed to the metabolite. Average recoveries for THC, cannabidiol (CBD), cannabinol (CBN) and THCCOOH by this HPLC system were 91.1%, 93.6%, 90.1% and 91.4% detected by UV 212nm; 88.9%, 93.5%, 88.9% and 90.7% by UV 220nm and 93.4%, 94.7%, 98.7% and 89.1% by ECD +1.10V, respectively. Calibration curves were linear from 0-100ng/ml for both UV detection wavelengths, and within the range 0-200ng/ml for ECD detection. When eight test samples were analysed, which were positive when screened for cannabinoids by radioimmunoassay, none of the samples gave positive results for THC and CBN. Electrochemical detection but not UV detection gave five samples positive for CBD, while THCCOOH was found to be present in all of the test samples. GC-MS analysis was performed under full scan, selected ion recording (SIR), multiple reaction monitoring (MRM) and negative ion chemical ionisation (NICI) modes. Extracted samples were not cleaned up with Bond Elut Certify II in order to evaluate the sensitivity and selectivity of the different GC-MS modes. Full scan mass spectra of THC, THCCOOH and their derivatives were compared. They were found to produce parallel series of ion fragments through similar fragmentation mechanisms. Analyses by SIR-MS were performed to confirm the identity of the analytes in blood extracts. Calibration curves for THC and THCCOOH were linear from 0-100ng/ml. When the same eight test samples were analysed, three of them were found to be positive for THCCOOH, but only two of the samples gave positive results for THC. In the MRM mode, the transitions to the most prominent daughter fragments [M-15]+ formed by the parent analytes, THC and THCCOOH, were monitored. Linear calibration curves were obtained within the range 0-100ng/ml. In conclusion, the optimum method established in this study was acetonitrile extraction of blood samples followed by GC-MS in El(+) selected ion recording mode used as the end-step analysis. Sample clean-up is not essential but would help in prolonging the column life
Effects of Post-Deposition Annealing Temperatures on the Composition of Interfacial Layer at Germanium (Ge) /Aluminium Oxide (Al2 O3 ) (Kesan Suhu Penyepuhlindapan Pasca Pemendapan ke atas Komposisi Antara Muka Lapisan Oksida Germanium (Ge)/Aluminium (Al2 O3 ))
The understanding of chemical bonding structure of high k dielectrics/Germanium (Ge) interface is upmost importance
in order to form a good quality dielectric/Ge interface in fabricating Ge metal oxide semiconductor field effect transistor (MOSFETs). In addition, there is still no detail explanation on the interfacial growth of dielectrics/Ge under the influenced of different temperature of post deposition anneal. In current work, the effects of post deposition anneal (PDA) temperature
between 400°C and 600°C on the chemical composition of interfacial layer between Ge and Al2 O3 were examined by X-ray photoelectron spectroscopy (XPS). Investigation on thermal stability and structural characteristics for gate structure of Al2 O3 dielectric grown on Ge by RF sputtering was done by analyzing X-ray photoelectron spectroscopy (XPS) spectra.
It is observed that the oxygen deficient region in interfacial layer (IL) is enhanced rather than fully oxidized Al2 O3 with increased PDA temperatures. These undesired phenomena caused shrinkage of IL at Ge/Al2
O3 interface at higher temperature of 600°C
Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial
Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council
Impact of a ‘Research in pharmacy’ course on students’ self-reported competence and confidence to conduct research: findings from a Malaysian university
Objective: To evaluate the impact of a ‘Research in Pharmacy’ course on students’ self-reported competence and confidence to plan and conduct pharmacy practice research. Method: This is a pre- and post-intervention study conducted among third year pharmacy undergraduate students in a public university in Malaysia using an online questionnaire. A ‘Research in pharmacy’ course which encompassed lectures, tutorials, and practical sessions was delivered over a 14-week period. The students were divided into groups and assigned a project supervisor to guide them in planning and conducting a research project that was completed in one term.
Result: Of the 109 students, 69 and 62 completed the questionnaire in the pre- and postintervention periods, respectively. Students’ interest in conducting research and their interest in learning about research was similar in both periods. However, self-reported ability to conduct research increased significantly. Self-reported competence and confidence to conduct most components of research improved significantly (p < 0.05), although, extreme/very competent or confidence level was lower than 50% for most items. Overall, median total competence score (66.0 versus 74.0, p < 0.001) and median total confidence score (66.0 versus 71.5, p < 0.001) increased significantly after the course. Most students were very satisfied/satisfied with the
online lectures (54.8%) and online project supervision (64.6%). Lack of time (61.3%) was the major challenge students encountered during the course. Conclusion: A ‘Research in
pharmacy' course with both didactic and experiential components improved self-reported competence and confidence to plan and conduct research among pharmacy undergraduate students. Future studies should investigate the facilitators and barriers to students’ interest in pharmacy practice research
Effects of post-deposition annealing temperatures on the composition of interfacial layer at germanium (Ge) /aluminium oxide (Al2O3)
The understanding of chemical bonding structure of high k dielectrics/Germanium (Ge) interface is upmost importance in order to form a good quality dielectric/Ge interface in fabricating Ge metal oxide semiconductor field effect transistor (MOSFETs). In addition, there is still no detail explanation on the interfacial growth of dielectrics/Ge under the influenced of different temperature of post deposition anneal. In current work, the effects of post deposition anneal (PDA) temperature between 400°C and 600°C on the chemical composition of interfacial layer between Ge and Al2O3 were examined by X-ray photoelectron spectroscopy (XPS). Investigation on thermal stability and structural characteristics for gate structure of Al2O3 dielectric grown on Ge by RF sputtering was done by analyzing X-ray photoelectron spectroscopy (XPS) spectra. It is observed that the oxygen deficient region in interfacial layer (IL) is enhanced rather than fully oxidized Al2O3 with increased PDA temperatures. These undesired phenomena caused shrinkage of IL at Ge/Al2O3 interface at higher temperature of 600°C
Need of risk management practice amongst bumiputera contractors in Malaysia construction industries
Array CGH based identification of amplified chromosome 8p11.23-11.22 region encompassing ADAM9 gene.
<p>Array CGH based identification of amplified chromosome 8p11.23-11.22 region encompassing ADAM9 gene.</p
Array CGH based identification of amplified chromosome 7q34 region encompassing MGAM gene.
<p>Array CGH based identification of amplified chromosome 7q34 region encompassing MGAM gene.</p
Socio-demographic and clinic-pathologic parameters of 46 OSCC patients.
<p>Socio-demographic and clinic-pathologic parameters of 46 OSCC patients.</p
The ideogram of top most frequently CNAs in term of amplifcations and deletions identified in this study using aCGH.
<p>The ideogram of top most frequently CNAs in term of amplifcations and deletions identified in this study using aCGH.</p