A presença de antibióticos no ambiente evidencia o problema do descarte inadequado de resíduos farmacêuticos e da ineficiência dos atuais sistemas de tratamento de resíduos. Como consequência a essa contaminação há a possibilidade de resistência microbiana e de outros efeitos nocivos, ainda não completamente compreendidos, sobre a fauna e flora aquática. O presente trabalho teve como um dos objetivos desenvolver métodos de preparo de amostra e análise para avaliar o potencial de um reator anaeróbio de leito fixo para a remoção de sulfonamidas de matrizes complexas, além de investigar possíveis resíduos dessa classe em diversos compartimentos ambientais da cidade de São Carlos. Para isso, métodos utilizando extração em fase sólida (SPE) e cromatografia líquida (LC) foram desenvolvidos em associação à análise por espectrometria de massas. Os resultados mostraram que o reator utilizado consegue remover satisfatoriamente o composto investigado, podendo ser, futuramente, uma alternativa aos tratamentos convencionais. Tais resultados foram obtidos a partir do desenvolvimento e validação de um método utilizando detecção por um analisador híbrido do tipo quadrupolo-tempo de voo (SPE-LC-QTOF). Outro método, baseado em SPE-LC-QTRAP (analisador híbrido quadrupolo-aprisionador de íons linear), foi validado visando mostrar que existe contaminação por sulfonamidas e trimetoprima em águas de córregos coletadas em algumas regiões da cidade. Tal objetivo foi atingindo, permitindo inclusive a comparação entre as figuras de mérito obtidas durante a validação dos métodos, que indicou que os analisadores (e os sistemas utilizados, em geral) possuem diferenças significativas que influem em parâmetros como o efeito de matriz, os limites de quantificação e a sensibilidade.<br/> Paralelamente aos métodos convencionais, alternativas de preparo e análise que reduziam a necessidade de grandes volumes de amostra e solventes também foram desenvolvidos. A associação de técnicas miniaturizadas de preparo de amostra e análise permitiu que limites de detecção comparáveis aos dos métodos utilizando SPE fossem atingidos, utilizando, inclusive, o analisador do tipo tempo de voo. Dessa forma, um novo escopo de aplicações usufruindo das características deste último analisador poderá ser desenvolvido a partir da melhor pré-concentração proporcionada pelas estratégias de miniaturização estudadas. / The presence of antibiotics in the environment demonstrates the problem of improper drug disposal and inefficiency of the current water treatment systems. As a result of this contamination, there is the possibility of microbial resistance and other harmful effects, not totally understood, on the aquatic flora and fauna. The present study aimed to develop methods for sample preparation and analysis in order to evaluate the potential of an anaerobic fixed bed reactor for removing sulfonamides from complex matrices and, in addiction, to investigate the presence of this class of contaminants in various environmental compartments of São Carlos. For this, methods using solid phase extraction (SPE) and liquid chromatography (LC), were developed in association with the analysis by mass spectrometry . The results showed that the reactor used can satisfactorily remove the compound investigated and may be, in future, an alternative to conventional treatments. These results were obtained from the development and validation of a method based on solid phase extraction associated with liquid chromatography coupled to mass spectrometry using a hybrid quadrupole-time of flight (SPE-LC-QTOF) analyzer. Another method that was also developed and validated, based on SPE-LC-QTRAP (hybrid quadrupole-linear ion trap), was useful to show that there is contamination by sulfonamides and trimethoprim in water collected from rivers in some areas of the town. This objective was achieved, inclusive allowing the comparison between the figures of merit obtained during the methods validation, which indicated that the analyzers (and the systems used, in general) have significant differences which that affect parameters as matrix effect and quantification limits.<br/> In parallel with the conventional methods, alternatives of sample preparation and analysis that reduced the need of large volumes of sample and solvent were also developed.<br/> The association of miniaturized techniques of sample preparation and analysis allowed detection limits comparable to that of methods using SPE, even using small volumes of sample and solvent and a less sensitive mass analyzer. Thus, a new scope of applications, taking advantage of the characteristics of the QTOF, can be developed from the higher pre-concentration provided by the strategies studied in this work.

Atualmente, a demanda e a necessidade de metodologias analíticas e bioanalíticas que promovam análise rápida e seletiva tem impulsionado o constante desenvolvimento de sorventes para preparo de amostra e fases estacionárias para cromatografia líquida de alta eficiência (HPLC). Desta maneira, esta tese tem por objetivo desenvolver materiais utilizando precursores de sílica com aplicação em preparo de amostra e suportes cromatográficos para cromatografia líquida de ultra alta eficiência (UHPLC). Foram sintetizadas e caracterizadas duas fases extratoras as quais tiveram sua aplicabilidade demonstrada na extração de fármacos em fluidos biológicos empregando a técnica de extração em fase sólida (SPE). A primeira metodologia desenvolvida foi a síntese de partículas de sílica empregando precursores de baixo custo (silicato de sódio) pelo método sil-gel. Após a funcionalização com grupamento C18, e caracterização da fase extratora, o material sintetizado foi aplicado em SPE off-line para a determinação de fluoxetina e seu metabólito, norfluoxetina, em plasma humano por HPLC-UV. O método desenvolvido foi validado e aplicado em amostra de plasma de pacientes sob tratamento de fluoxetina. Além disso, o sorvente desenvolvido apresentou resultados similares quando comparado com fases extratoras comerciais. O segundo método desenvolvido utilizou a técnica de impressão molecular (MIP) a qual tem se tornado uma fase extratora atrativa devido a sua maior seletividade em relação as fases típicas empregadas em SPE. Ao mesmo tempo, o uso de SPE online com MIP (MISPE) é uma alternativa atraente no preparo de amostra, pois é simples, diminui o tempo total da análise, necessita de pequena quantidade de amostra, e pode ser automatizado. Assim, MIP amino-funcionalizado pelo processo sol-gel utilizando ibuprofeno como template foi sintetizado. Para comparação, o polímero não impresso (NIP) foi preparado nas mesmas condições, sem a presença do template. As análises por cromatografia líquida foram realizadas utilizando uma coluna de extração MIP e uma coluna analítica em fase reversa configuradas para operar no modo SPE online por column switching. O método desenvolvido, MISPE-HPLC-UV, foi validado e aplicado na extração seletiva de cinco anti-inflamatórios não esteroidais (NSAIDs) em urina humana com um tempo total de análise de 22 minutos. Além dos materiais voltados para preparo de amostra, foi avaliado a síntese e caracterização de suporte cromatográfico baseado em sílica com diâmetro de partícula abaixo de 2 &micro;m com aplicabilidade em análises rápidas em cromatografia (UHPLC). Nesta vertente, partículas de sílica esférica não porosa (0,9 &micro;m) foram sintetizadas pelo método sol-gel com DPR abaixo de 10 %. As partículas foram funcionalizadas com o grupamento C18 (ODS) e submetidas posteriormente ao processo de endcapping (TMS) para operar em modo reverso. Métodos físico-químicos de caracterização foram utilizados para determinar a morfologia, área superficial e quantidade de carbono na superfície do material. Adicionalmente, as técnicas de infravermelho e ressonância magnética nuclear forneceram informações sobre a estrutura da sílica e das ligações após a funcionalização. A fase estacionária foi empacotada em uma coluna (40 mm x 0,25 mm) e a sua aplicabilidade foi avaliada em cromatografia líquida capilar (cLC). Apesar de não alcançar a eficiência ótima da separação cromatográfica devido a limitação instrumental, a fase estacionária sub 1 &micro;m apresenta potencial para separações rápidas sem perda de eficiência. / Currently, the demand and need for bioanalytical and analytical methodologies that promotes rapid and selective analysis has stimulated the development of sorbents for sample preparation and stationary phases for high performance liquid chromatography (HPLC). Therefore, this thesis aims to develop materials using silica precursors with application in sample preparation and chromatographic supports for ultra high performance liquid chromatography (UHPLC). Thus, in this study two sorbents were synthesized and characterized and their applicability was demonstrated in the extraction of drugs in biological fluids employing the solid phase extraction technique (SPE). The first method developed was the synthesis of silica particles employing low cost precursors (sodium silicate) using the sil-gel method. After functionalization with C18 group and characterization of the extraction phase, the synthesized material was applied to SPE off-line for the determination of fluoxetine and its metabolite, norfluoxetine, in human plasma by HPLC-UV. The method was validated and applied to plasma samples from patients treated with fluoxetine. Furthermore, the labmade sorbent presented similar results when compared with commercial ones. The second method developed used the molecular imprinting technique (MIP) that has become an attractive sorbent due to its greater selectivity over the typical phases employed in SPE. At the same time, the use of online SPE with MIP (MISPE) is an attractive alternative in sample preparation because it is simple, reduces the total time of analysis, needs little amount of sample and can be automated. Thus, MIP amino-functionalized by the sol-gel method using ibuprofen as template was synthesized. For comparison, the non-imprinted polymer (NIP) was prepared under the same conditions without the presence of template. LC analysis was performed using a MIP extraction column and a reverse phase analytical column in order to perform column switching on-line sample separation. The developed method, MISPE-HPLC-UV, was validated and applied to the selective extraction of five anti-inflammatory drugs (NSAIDs) in human urine with a total analysis time of 22 minutes. Moreover it was evaluated the synthesis and characterization of chromatographic support based on silica with particle diameter under 2 &micro;m with applicability in fast LC analysis (UHPLC). In this instance, spherical particles of non-porous silica (0.9 &micro;m) were synthesized by sol-gel method with RSD below 10 %. The particles were functionalized with the C18 group and submitted to the endcapping process with TMS to operate in reverse phase mode. Physico-chemical methods were used to determine the morphology, surface area and amount of carbon in the silica surface. Additionally, the infrared and nuclear magnetic resonance techniques provided information about the structure of silica and bonds after the functionalization step. The stationary phase was packed into a column (40 mm x 0.25 mm), and its applicability was evaluated in capillary liquid chromatography (cLC). Although optimum chromatographic efficiency was not achieved separation due to instrumental limitations, the sub 1 &micro;m stationary phase has potential for rapid separations without loss of efficiency.

Phospholipids (PLs) are a component of cell membranes, biological fluids and tissues. These compounds are problematic for the bioanalytical chemist, especially when PLs are not the analytes of interest. PL interference with bioanalysis highly impacts reverse-phase chromatographic methods coupled with mass spectrometric detection. Phospholipids are strongly retained on hydrophobic columns, and can cause significant ionization suppression in the mass spectrometer, as they out-compete analyte molecules for ionization. Strategies for improving analyte detection in the presence of PLs are reviewed, including in-analysis modifications and sample preparation strategies. Removal of interfering PLs prior to analysis seems to be most effective at moderating the matrix effects from these endogenous cellular components, and has the potential to simplify chromatography and improve column lifetime. Products targeted at PL removal for sample pre-treatment, as well as products that combine multiple modes of sample preparation (i.e. Hybrid SPE), show significant promise in mediating the effect on PL interference in bioanalysis.

A lack of knowledge about the usefulness of a field experience component within the associate principal preparation program for assistant principals drove this study. The purpose of this qualitative study was to describe the beliefs of system leaders and past participants regarding the usefulness of the field experience component and to examine archival end-of-course survey data from past participants. Constructivism and adult learning theory constituted the conceptual framework. Twelve leaders who were participants or administrators of the program within a large mid-Atlantic school district in the United States were participants. Qualitative data sources included interviews and archival data from the associate principal preparation program. A combination of descriptive and in vivo coding was used to support interpretive analysis. Results indicated the most useful components of the principal preparation program were the experiential nature of the program, opportunity for reflective thinking for participants, benefits of mentoring throughout the field experience, and empowerment felt by participants as they practiced skills learned during the field experience in their first year as principals. Recommendations based on these findings included a lengthened field experience and greater focus on the criteria used to match aspiring principals with mentor principals. Participants also noted fiscal and human capital resources were needed. A related recommendation could be to extend the field experience over 2 years to provide opportunities for associate principals to participate in experiences in the beginning and end of the school year in addition to the middle of the school year experiences provided. This research could provide support for districts interested in assessing the usefulness of their principal preparation programs.

Preservice teachers of reading develop their beliefs and understanding of reading pedagogy in diverse ways. While they do gather some knowledge and understanding from their university preparation courses and their practicum experiences in classrooms, a less transparent source of emerging understandings of reading pedagogy is their own experiences with reading instruction as students. Using a qualitative case study methodology, this dissertation study investigated how three preservice teachers interested in early childhood education developed understandings of reading pedagogy. Data collected included three interviews; two prompted reflective writings on their evolving understandings; observation in the participants’ reading processes course; and an interview with the course instructor. Findings indicated that preservice teachers’ biographies influenced both their understanding of how to teach reading and their attitudes toward it. Also, they favoured practicum experience over university coursework as a source of knowledge, and experienced tensions when their own beliefs contradicted the ideas espoused in the university course. In general, preservice teachers’ beliefs and experiences prior to starting their teacher education program caused resistance toward research-based theories and practices related to reading. Findings imply that teacher educators need to be explicit in providing many opportunities for their students to discuss and make sense of their epistemological understandings in relation to areas of tension with reading pedagogy. / Graduate

This dissertation builds upon stress and burnout research on school leaders by exploring the beliefs and practices regarding well-being and self-renewal of principals identified as successful. This study utilized a 3-fold framework that consisted of mind, body, and spirit, falling under the all-encompassing umbrella of thriving, asserting the three domains work together to support the optimal well-being of the leader. The research questions were as follows: (1) In what ways are principals' well-being and self-renewal supported by principals' personal beliefs and practices, district policies and practices, and educational programs and organizations? (2) To what extent does attentiveness to well-being and practices of self-renewal impact professional success and work satisfaction, and well-being and flourishing? This study included a diverse group of six principals, all identified as successful and all with three or more years of experience as administrators. The case study consisted of mostly interviews with some survey inquiry. The primary method of analysis was holistic descriptive and in vivo coding with loose applications of formal protocols provided by Saldaña (2009). In my final analysis the participant responses were organized into categories and layered into my pre-existing framework of mind, body, and spirit. The findings from the study revealed the current successes and challenges in the personal and professional renewal of principals. The findings yielded implications for research and practice specific to principals, school districts, and principal preparation programs.

The pervasiveness of injustices is rooted in structures and ideology that reinforce and reinvent oppression; there is a need to engage in transformative change to dismantle systems of domination and subordination. Educational leadership is essential in the social transformation of educational settings and the wider society. In the collective responsibility for transformative change, educational leadership preparation programs serve as spaces to encourage the development of students’ capacity to address issues of oppression and create new power relations for social justice. Faculty play a role in preparation programs to enact teaching that uncover to power dynamics of oppression and domination for social emancipation. The purpose of this critical qualitative study was to understand how faculty in doctoral educational leadership preparation programs teach to encourage students’ capacity development to engage in transformative leadership. The guiding question for this study is: How do faculty engage in teaching to encourage students’ capacity development to understand and transform social oppression affecting education? Using an interview methodology, data is generated through relational interviewing using artifacts. The conceptual framework of critical pedagogy, transformative criticality, and transformative leadership development guides a sociocultural approach to the analysis of the data. There were four major findings: The participants (1) integrated critical frameworks into curriculum and pedagogical approaches, (2) established spaces in and outside of the formal classroom to engage students, (3) centered student-faculty relationships for support and collaboration, and (4) evoked students’ transformative activism through academic practice. This empirical study will contribute to the research on critical perspectives in educational leadership preparation programs with a focus on faculty teaching as an expression of transformative power.

The purpose of this study was to analyze the attitudes and practices of Southern Baptist pastors in four Midwestern states toward premarital education. The researcher utilized a multi-stage sampling procedure to randomly select 1070 churches in Missouri, Tennessee, Illinois, and Kentucky. A research tool was created to record demographic information about the research participants and also to record the attitudes and practices of the sample toward premarital education. A content analysis was conducted which identified the top 11 recommendations from the literature base for premarital education curricular content areas. The curricular content components reportedly present in the practices of the sample were compared against the curricular content areas in the literature base. Finally, the researcher investigated the relationship between the presence of certain curricular content components of present in the practices of the sample and certain demographic characteristics of the sample.

The increasing number of patients undergoing treatment with assisted reproductive techniques (ART) during the past years have led to the need of developing different methods for separation of spermatozoa that can be used for different fertilisation procedures and for freezing. Cryopreservation of spermatozoa includes preparation, freezing, storage and thawing. In this study two different cryomedia (Cryo Protec I and Cryo Protec II) for human spermatozoa were compared. The main outcome was spermsurvival rate for spermatozoa after freezing. Sperm viability was assessed using the Hypo-osmotic swelling test which is based on osmolality. A total of 86 samples of semen were used in this study (Cryo Protec I=38, Cryo Protec II=48). The survival rate between the two cryomedia did not differ much but Cryo Protectant I showed a small increase in survival for the spermatozoa after freezing. The Hypo-osmotic swelling test also showed similar values of viable spermatozoa for the two cryomedia both before and after freezing.

No description available.