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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.
1

Application of High Resolution Mass Spectrometry for the Screening and Confirmation of Novel Psychoactive Substances

Seither, Joshua Zolton 25 April 2018 (has links)
There has been an emergence of novel psychoactive substances (NPS) in forensic casework globally. Although the reported prevalence of these compounds has been relatively low in comparison to traditional drugs of abuse, published case studies suggest that some NPS have significant pharmacological effects that may cause severe impairment and/or death. Because of these effects, it is important that toxicology laboratories have the capability of identifying these compounds to complete a comprehensive toxicological analysis for human performance and post-mortem investigations. Recently, mass spectrometry has gained favor over traditional screening assays such as immunoassays for the identification of NPS in biological specimens. This trend is mainly a result of the fact that mass spectrometry provides the required sensitivity and selectivity for a broader range of analytes. High resolution tandem mass spectrometry has been suggested for analysis of NPS, as this technique further increases selectivity by increasing mass accuracy and providing MS/MS spectral data. The main goal of the present study was to investigate the applicability of using high resolution mass spectrometry to screen for and confirm a large number of novel psychoactive substances. The present study consisted of three main tasks, which included 1) the creation of a large high resolution MS/MS spectral library and database, 2) the development of a solid phase extraction (SPE) method and acquisition methods, and 3) a collision induced dissociation (CID) study of regioisomeric NPS compounds. The MS/MS spectral library created contains spectral data for 252 NPS. In addition, 875 NPS entities were included in the compound database. The library and database can be used by toxicology laboratories to aid in the identification of NPS in casework using MS/MS spectral data and full scan MS data, respectively. The analytical method developed used SPE and high resolution mass spectrometry (HRMS). The HRMS method demonstrated limits of detection ranging from 0.5- 5 ng/mL for NPS from various structural drug classes. The CID experiments demonstrated that relative ion abundance alone could be used to differentiate some sets of regioisomers. The present work can aid toxicology laboratories in the identification of NPS and demonstrates the applicability of HRMS for their screening and confirmation.
2

Simultaneous detection of drugs of abuse in waste water using gas chromatography-mass spectrometry

Mwenesongole, Ellen Musili January 2015 (has links)
Sewage epidemiology is increasingly becoming an alternative method of estimating drug usage and consumption patterns for a given population. With the constant emergence of new psychoactive substances such as cathinones and piperazines, versatile, reliable, specific and sensitive analytical methods are needed for their detection in complex matrices such as waste water. This thesis reports the development of an analytical method based on solid phase extraction, derivatization with pentafluoropropionic anhydride and analysis by gas chromatography-mass spectrometry for the simultaneous analysis of 29 illicit and therapeutic drugs of abuse. All 29 drugs could be reliably identified in spiked waste water samples using selected ion monitoring and splitless injection. Recoveries for the majority of the drugs were above 70 %. Linearity varied based on the analyte but was assessed in the range 2.0 x 10-4 to 1.4 μg/mL. Intra-assay and intermediate precision of the instrument was determined at 0.005, 0.1 and 1.0 μg/mL, with the majority of relative standard deviations less than 10 %. Limits of detection and quantification for drugs such as amphetamine and methamphetamine were better than reported values for liquid chromatography-tandem mass spectrometry, a more commonly used technique. Untreated 72 h composite waste water samples from Cambridge, UK, were analysed using a six-point standard addition curve. Eleven drugs of abuse were detected, including amphetamine, methamphetamine, butylone and 4-fluoromethamphetamine. The latter two having been detected for the very first time in waste water. Using the validated method, the consumption of heroin, ketamine, cocaine, methamphetamine and amphetamine, in Cambridge, UK, was estimated to be 399.4 ± 90.8, 2463.5 ± 182.5, 195.5 ± 95.4, 84.3 ± 59.1 and 38.9 ± 24.8 mg/day per 1000 inhabitants. This is the first reported validated method for the detection of both classic drugs of abuse and new psychoactive substances in waste water using gas chromatography-mass spectrometry and derivatization with pentafluoropropionic anhydride.
3

Development of chemical sensors for rapid identification of amphetamine-related new psychoactive substances

Kellett, Kathryn Emily January 2017 (has links)
A molecular receptor for mephedrone, an amphetamine-like NPS, was developed using host-guest chemistry and pharmacophoric design. The in-field detection of new psychoactive substances (NPS) is an area that has garnered considerable attention in the last few years. With the continuously expanding number of NPS on the market, traditional detection mechanisms lack the selectivity needed. In this project a new methodology has been developed for the design of host molecules for use in in-field detection, based on biomimetic design. To understand what a sensory molecular needs to be selective against, GC-MS and HPLC analysis were employed to identify and quantify thirteen aminoindane internet samples. It was found that the composition of internet samples varies greatly in terms of concentration of active ingredient, with a range of 17-95 % w/w of active ingredient identified. It was also found that caffeine was the most common cutting agent with a range of 27.7-30.2 % w/w identified. This highlights the need for both selectivity and sensitivity in detection mechanisms. Using the principles of biomimetic design, a methodology for the treatment of protein-ligand interactions was developed. Protein-ligand binding data collected from the Protein Databank was analysed for mephedrone related structures and common cutting agents, identified through aminoindane internet sample analysis and literature sources. From this work a three-point pharmacophoric model was developed, upon which two host molecules were considered, macrocyclic calixarenes and acyclic anthraquinones. Both contained the three binding interactions deduced from the pharmacophore design; two p-stacking interactions and one hydrogen bond acceptor. The final host molecule taken forward for testing was 1,8-dibenzylthiourea anthracene (Probe 1). The binding affinity of Probe 1 to mephedrone was tested using 1H-NMR. An estimated association constant of 104 M-1 was calculated, with a 1:1 binding stoichiometry. Along with ESI-MS and DFT calculations, it was found that mephedrone binds to Probe 1 in a concerted fashion with a three-point binding geometry, with two hydrogen bonds and one p-stacking interaction. A modest optical response using fluorescence spectroscopy was also observed between mephedrone and Probe 1 at high molar concentrations. A more pronounced response was observed upon addition of high molar concentrations of flephedrone. 1H-NMR showed that Probe 1 selectively bound mephedrone over methamphetamine as well as the four most common cutting agents identified from literature: lidocaine, caffeine, paracetamol and benzocaine, which have been shown to cause false positives in previous studies. Probe 1 showed significant selectivity for the β-ketoamine arrangement. This is supported by the systematic analysis of mephedrone, methamphetamine, mephedrone precursor and flephedrone. This is the first time this has been achieved using host-guest chemistry. A protocol was developed to successfully detect mephedrone via Probe 1 using NMR spectroscopy in a simulated street sample containing two of the most common cutting agents, benzocaine and caffeine. To further aid future design of small host molecules a methodology for the in silico analysis of small molecule host-guest binding using metadynamics was explored. Solvent interactions with the host and guest molecules were observed, highlighting the importance of solvent choice in binding studies. Metadynamics shows potential to be used in further work for improving the approach in which host molecules are designed in future.
4

Calando-se para se preservar de um contexto ameaçador, mediante a fragilidade de se resgatar o aluno da rede pública de ensino, em interações com substâncias psicoativas: a experiência do professor

Rossi, Lilian Cristina de Castro [UNESP] 20 August 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-20Bitstream added on 2014-06-13T19:17:57Z : No. of bitstreams: 1 rossi_lcc_me_botfm.pdf: 652525 bytes, checksum: 58fb6a36bda9dcecf2a492a6e9a858d8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O uso de substâncias psicoativas sempre esteve presente na história da humanidade, porém, devido ao crescente e precoce consumo transformou-se em problema mundial de Saúde Pública, gerando em todas as partes do mundo importantes questões sociais e de saúde, exigindo medidas de enfrentamento que implicam, entre outras, não só a identificação da prevalência, mas também o aprofundamento compreensivo das experiências dos atores envolvidos no processo. Entre estes fatores considerou-se, neste estudo, o papel dos professores, no acompanhamento destas crianças em ambiente escolar, entendendo a escola como um espaço em que criança e adolescentes permanecem diariamente e por longos períodos construindo e desenvolvendo, entre outras coisas, suas normas de comportamento e convivência sociais. O estudo foi realizado com 32 professores de três escolas públicas estaduais da cidade de Penápolis, SP, lotados em duas escolas periféricas e uma central, objetivando: compreender a interação do professor da rede pública com aluno usuário de substâncias psicoativas e desenvolver modelo teórico representativo desta experiência. Pesquisa conduzida nos padrões da Declaração de Helsinque, aprovada pela comissão de ética UNESP-Araçatuba. Referencial teórico Interacionismo Simbólico. Referencial metodológico Grounded Theory. Técnica de coleta de dados grupos focais. Foram identificados três fenômenos: Identificando os alunos usuários de substâncias psicoativas: ouve rumores; percebe manifestações relativas ao uso; observa o aluno assumindo condição de usuário, pondera sobre fatores protetores e indutores ao uso. Sentindose impotente perante os desafios do uso de substâncias pelos alunos: o professor tenta ajudar o aluno, agindo como conselheiro e comunicando o problema á direção, que chama a família visando compreender a problemática. Entretanto, se depara com... / To understand the interaction of public-school teachers with students who use psychoactive substances and to develop a representative theoretical model. A study conducted according to the standards stated in the Declaration of Helsinki and approved by the Ethics Committee of UNESP-Araçatuba. Theoretical framework: Symbolic Interactionism. Methodological framework: Grounded Theory. Data collection technique: focal groups. Three phenomena were identified: Identifying students who use drugs: hear rumors; perceives manifestations related to the use; observe students assuming the condition of users and ponder about protective and use-inducing factors. Feeling powerless in face of the challenges found: teachers attempt to help students by acting as counselors and communicating the problem to the school principal, who calls student’s families with the purpose to understand their problematic conditions. However, they find unstructured families, inefficient Guardianship Councils, lack of preparation to approach the topic and lack of public policies. Teachers remain silent to preserve themselves from the world of drugs: The connection with criminality and violence leads to stigma and prejudice which pursue schools, students and their families, causing teachers to remain silent in order to preserve themselves from the world of drugs. Core category: Silencing in order to protect oneself from a threatening context in face of the fragility in rescuing public school students in interaction with psychoactive substances. Conclusions: Teachers identify signs of use and abuse as well as risk and protection factors for substance use. They should participate in preventive actions together with relatives, health care professionals and government institutions aiming at children’s and adolescents’ integral health in the school environment. Coping actions for damage reduction in the school environment... (Complete abstract click electronic access below)
5

Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry

Gwak, Seongshin 17 September 2015 (has links)
In the new era of drug abuse, the proliferation of new psychoactive substances (NPS), commonly referred to as designer drugs or legal highs, has been a global concern. These substances are produced to circumvent current legislation for controlled substances with minor modifications in their chemical structure. Although many efforts have been made previously, the characterization of such substances are still challenging because of (1) the continual emergence of newly identified substances, (2) the lack of a universal screening test for NPS that are structurally similar to each other, and (3) the complex and time-consuming chromatographic techniques currently used. Therefore, it is necessary to develop novel analytical methods that can be readily adapted by forensic laboratories to overcome these challenges. In this dissertation, various analytical techniques have been evaluated for qualitative analysis of these emerging NPS. For rapid screening purposes, a commercial ion mobility spectrometry with a 63Ni ion source (63Ni-IMS) and also direct analysis in real time coupled to a quadrupole time-of-flight mass spectrometer (DART-QTOF-MS) were investigated first. The results showed that rapid detection by 63Ni-IMS and identification by DART-QTOF-MS can be achieved with sub-nanogram detection capability and high speed total analysis time less than two minutes. In recent developments of gas chromatography mass spectrometry (GC-MS), gas chromatography (GC) has been coupled to state-of-the-art mass spectrometers, including triple quadrupole (MS/MS) and quadrupole time-of-flight (QTOF). It was revealed that the application of GC-MS/MS and GC-QTOF facilitates the unambiguous identification of emerging NPS with a chemical ionization (CI) source. In addition, constitutional isomers of NPS were differentiated with the capabilities of product ion scan and multiple reaction monitoring (MRM) modes. Finally, the coupling of IMS with a mass spectrometer (IMS-MS) was investigated as an alternative confirmatory technique. With the development of an optimal solvent system in the electrospray ionization (ESI) process, the rapid analysis and identification of synthetic cathinone was successfully achieved less than five minutes. As a proof-of-concept, seized drugs samples provided by a local forensic laboratory were analyzed using these developed methods by various analytical techniques. The results from these seized samples are also presented in this evaluation.
6

Studying and Modifying Paper to Lower Detection Limits for Paper Spray Mass Spectrometry

Bills, Brandon John 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In this work we developed paper spray mass spectrometry methods to obtain lower detection limits for pharmaceuticals and drugs of abuse. The second chapter investigates blood fractionation membranes for their ability to obtain lysis free plasma from whole blood without changing the drug concentration relative to centrifugation. We presented a device capable of obtaining and analyzing plasma samples from whole blood and obtaining quantitative results similar to traditional methods. In the third chapter the properties of the paper substrate are investigated systematically for their impacts on ionization efficiency and recovery in combination with the solvent choice. The fourth and fifth chapters detail a simple method for lowering detection limits using a method called paper strip extraction. In this method biofluids are wicked through either sesame seed oil or solid phase extraction powder on a paper strip to concentrate and preserve (in the case of THC) analytes out of biofluids. The use of 3D printing for rapid prototyping and how it potentially impacts paper spray MS sensitivity is outlined in the final chapter.
7

Designer benzodiazepines gidazepam and desalkygidazepam (bromonordiazepam): What do we know?

Maskell, P.D., Wilson, G., Manchester, Kieran R. 26 January 2023 (has links)
Yes / Designer benzodiazepines are one of the primary new psychoactive substances (NPS) threats around the world, being found in large numbers in post-mortem, driving under the influence of drugs (DUID) and drug facilitated sexual assault (DFSA) cases. Even though when compared to many other NPS types, such as opioids and cathinones, there are relatively few designer benzodiazepines being monitored. Recently a new NPS benzodiazepine has been reported in Europe, the USA and Canada, desalkygidazepam, also known as bromonordiazepam. This substance is a metabolite of the pro-drug gidazepam, a drug licenced for use in Ukraine and Russia under the name Gidazepam IC®. In the paper we review what is currently known about the use, pharmacology and analytical detection of gidazepam, its metabolite desalkygidazepam, and their other possible metabolites.
8

Vnímání zdravotních rizik intravenózní aplikace psychoaktivních látek ve skupině drogově závislých / Health hazards perception of intravenous application of psychoactive drugs in addicted group

PROKŠOVÁ, Michaela January 2010 (has links)
The addiction psychoactive substances currently represents a major problem. The number of users of such substances has been increasing. The intravenous application of psychoactive substances is associated with many health risks. Transmission and spreading of infection is associated mainly with frequent sharing and use of needles, syringes and other instruments among the users. In recent years the spreading of hepatitides (particularly VHC) has been reported as one of serious consequences of addiction to psychoactive substances, particularly in case of intravenous application. Protection against the spreading of diseases consist mainly in the prevention. The objective of the thesis is to verify whether the people addicted to psychoactive substances are aware of risks of transmission and spreading of infectious diseases (particularly VHC) as a result of intravenous application. The research was conducted on a group of drug addicts intercepted in the network of contact center and on a group of drug addicts in a therapeutic program of a psychiatric facility. I have used the method of inquiry in the form of questionnaires. In the thesis I set five hypotheses. The first, the third and the fifth hypotheses have been confirmed. The second and the fourth hypotheses have not been confirmed. The results of the research may be used by facilities providing low-threshold services as a part of secondary and tertiary prevention and harm reduction. It may also serve as source of information for workers dealing with anti-drug issues.
9

Estudo dos níveis motivacionais em relação ao uso de substâncias psicoativas e a espiritualidade / Study of motivational levels in relation to the use of psychoactive substances and spirituality.

Gonçalves, Angelica Martins de Souza 08 August 2008 (has links)
Existem evidências da relação entre espiritualidade e saúde, e também de que o exercício da dimensão espiritual tem potencial para estimular mudanças positivas entre usuários de álcool ou de outras drogas em processo de reabilitação. Este estudo teve como objetivo avaliar a relação entre espiritualidade e os níveis motivacionais (Modelo Transteórico) entre indivíduos que fazem uso nocivo ou são dependentes de substâncias psicoativas, em tratamento ou membros do grupo de mútua-ajuda e avaliar o desempenho da versão traduzida e adaptada da Spirituality Self Rating Scale (SSRS). O desenho metodológico do estudo é do tipo transversal. Um questionário foi elaborado contendo informações sociodemográficas e escalas de motivação e espiritualidade - URICA e SSRS, respectivamente. A amostra foi constituída de 138 (69%) indivíduos do sexo masculino. Participaram usuários vinculados a um grupo de AA, um serviço de CAPS-ad e três Comunidades Terapêuticas (evangélica, católica e sem vinculação religiosa). Dentre os resultados, foi encontrado que os entrevistados apresentaram idade média de 39 anos, católicos 71(51,4%), praticantes 83(60,1%). A maioria respondeu que a substância psicoativa consumida pela última vez foi o álcool 65(47,1%) e que 49(35,5%) usam ou usaram substâncias psicoativas por mais de 10 anos, todos ou quase todos os dias 90(60,2%). A escala SSRS apresentou bom índice de confiabilidade, com alfa de chronbach global de 0,8333, variando de 0,7028 a 0,8878. Não houve relação estatística significante entre espiritualidade e aspectos da vida religiosa dos indivíduos. A maioria 84(60,8%) considera espiritualidade diferente de religiosidade. Os estágios motivacionais que apresentaram relação com espiritualidade foram a pré-contemplação, a ação e a manutenção, mediante a análise de regressão linear múltipla. Os resultados nos fazem refletir que o exercício da dimensão espiritual em cada um dos estágios pode ser pensada no sentido de estimular o indivíduo a obter sucesso no processo de mudança de comportamento em relação ao uso de substância e na reabilitação em diversos contextos. A escala SSRS pode ser recomendada para uso, apesar de suas limitações. Concluímos que existe a necessidade de sucessivas avaliações dos processos que envolvem os aspectos da espiritualidade no contexto do tratamento e motivação na mudança de comportamentos em relação ao abuso e dependência de substâncias psicoativas. / There are evidences of the relationship between spirituality and health and also that the exercise of spiritual dimension has potential to stimulate positive changes among users of alcohol or other drugs, in the rehabilitation process. This study aimed to evaluate the relationship between spirituality and motivational levels (Transtheorical Model) among individuals who make harmful use or are dependent on psychoactive substances, in treatment or members of a group of mutual-help, and evaluate the performance of translated and adapted version of Spirituality Self Rating Scale (SSRS). The methodological design of the study is made on transversal type. A questionnaire was drawn up, containing sociodemographic information and motivation and spirituality scales - URICA and SSRS, respectively. The sample consisted of 138 (69%) males. Participating users were linked to a group of AA, a service of CAPS-ad and three Therapeutic Communities (evangelical, catholic and without religious ties). Amidst the results, it was found that the respondents had an average age of 39 years, catholics 71 (51.4%) and practitioners 83 (60.1%). The majority answered that the consumed psycoative substance for the last time was alcohol 65 (47.1%) and 49 (35.5%) use or used psychoactive substances for over 10 years, all or almost all day 90 (60,2%). The SSRS scale showed good index of reliability, with overall alpha of chronbach 0.8333, ranging from 0.7028 to 0.8878. There was no statistically significant relationship between spirituality and religious aspects. Most 84 (60.8%) considers spirituality different from religiosity. The motivational stages that showed association with spirituality were pre-contemplation, action and maintenance, through linear multiple regression analysis. The results make us reflect that the exercise of spiritual dimension in each stage can be considered to stimulate the individual to succeed in the process of behavior changing, in relation to the use of substance and rehabilitation in various contexts. The scale SSRS can be recommended for use, despite its limitations. We conclude that there is a need of successive assessments of the processes involving the aspects of spirituality, in context of treatment and motivation in the behavior changing, in relation to abuse and dependence of psychoactive substances
10

Young people's perceptions of novel psychoactive substances

Freeman, Jodie January 2018 (has links)
Novel Psychoactive Substances (NPS) also known as "legal highs" replicate the effects of illegal substances such as ecstasy and cocaine. The most common NPS reported are stimulants and synthetic cannabinoids. Despite the Psychoactive Ban (2016) recent reports identified the UK as having the largest market of NPS use anywhere in Europe. These substances have a short history of consumption and consequently little is known about their effects and health implications. Despite this, the sale of NPS is easily achieved through the internet and street dealers. Increased reports of negative health consequences from NPS consumption and research findings highlighting the willingness of young people to consume drugs without knowing what they are, mean it is vital that we investigate young people's understandings and perceptions of them. At present there are very few in-depth qualitative studies on NPS. A series of 7 focus groups with a range of young people (40=N: aged 16- 24 years) across the Merseyside area were carried out. Research sites included colleges, youth groups, supported living accommodations, and youth drug and alcohol services. Focus group interviews explored participants' perceptions of NPS and were followed up with a few semi structured interviews with selected participants. The direction of the study focused on mainly on synthetic cannabinoids which may reflect the age of the study's population. Using thematic analysis informed by a social constructionist perspective, three main themes were identified around stigma and identity, attractive features of NPS and risk. Findings showed that young people's perceptions of these substances were dependent on their level of experience with illegal substances and NPS. A novel finding was that synthetic cannabinoid use is employed in the normalisation of cannabis use. Local, national and policy recommendations are made on how youth and health services in both educational and specialised services could work more closely and effectively with young people NPS. They also identify a need among young people for specific guidelines on how to use the Internet and Print media in relation to previous knowledge and experience.

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