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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.
21

Opioid use disorder suppresses HIV-1 latent reactivation in people with HIV and a strategy for permanent repression of HIV-1 expression

Basukala, Binita 29 November 2023 (has links)
Of the 12 million people who inject drugs worldwide, 13% are chronically infected with Human Immunodeficiency Virus (HIV), i.e., they live with HIV. Chronic opioid use affects the host immune system and increases an individual’s susceptibility to HIV infection. However, it is unclear how opioid use changes the course of HIV pathogenesis. Particularly, there is a gap in understanding how opioids impact HIV latency. Latency results in a reservoir of infected quiescent cells that evade antiviral immune responses, are not targeted by antiretroviral therapy (ART), and allow HIV viremia to rebound upon treatment interruption. While in vitro studies show that opioids modulate the activity of transcription factors involved in T-cell activation and HIV transcription, few studies have investigated whether opioid use impacts HIV latency in vivo in HIV-infected people. In this research, peripheral blood mononuclear cells (PBMCs) were utilized from People with HIV (PWH) with or without recent opioid use or opioid use disorder (OUD) who were enrolled in the Linking Infection and Narcology Care-Part II (LINC-II) and Studying Partial Agonists for Ethanol and Tobacco Elimination in Russians with HIV (St PETER HIV ARCH) studies conducted in St. Petersburg, Russia. Intact proviral DNA digital droplet PCR (ddPCR) assays were performed on PBMCs from antiretroviral treated PWH, with (n=8) or without (n=11) current OUD, to quantify intact and defective proviral genomes. Samples from ART-treated PWH with OUD compared to those without OUD had similar levels of intact and defective proviruses. To evaluate latency reversal, PBMCs from ART-treated PWH with or without OUD, were activated with anti-CD3/28 beads and RT-ddPCR assays were performed to measure HIV LTR-gag RNA. A variable response in PWH without OUD was seen where half of the samples showed an increase in HIV RNA upon activation. Interestingly, only 1 of 8 samples from PWH with OUD showed an increase in HIV transcription. However, no suppression of HIV reactivation was found in vitro from latent cells generated using a primary CD4+ T-cell latency model in the presence or absence of morphine. Similarly, no differences in HIV integration and transcription in vitro were observed between morphine and control conditions. Additionally, expression of opioid receptors was not detected in primary PBMCs, CD4 T cells, or macrophages. These results show that PWH with OUD have a pool of persistent HIV proviruses that are refractive to reactivation, although opioids did not affect HIV replication and latency reactivation in vitro. The discrepancy in these in vitro and in vivo results and the lack of expression of opioid receptors in immune cells suggests that while opioids do not directly impact HIV replication, latency, and reactivation in target CD4+ cells, opioids could indirectly shape the HIV reservoir in vivo by modulating general immune functions, neuroderived factors or other cells that are responsive to opioids. Eradication of the latent HIV reservoir is necessary to achieve a cure for HIV/AIDS. One approach for latency eradication is the “shock and kill” approach that entails stimulating viral production with latency-reversing agents followed by the killing of cells actively producing the virus by immune clearance. However, this approach does not induce all intact proviruses, leaving a residual reservoir. An alternative approach is to permanently repress HIV expression precluding viral rebound after ART discontinuation. Here, a nuclease-deficient disabled Cas9 (dCas9) coupled with a transcriptional repressor domain derived from Kruppel-associated box (KRAB) was used to epigenetically silence the proviral DNA. I show that specific guide RNAs (gRNAs) and dCas9-KRAB repress HIV-1 transcription and reactivation of latent HIV-1 provirus. This repression is correlated with chromatin changes, including decreased H3 histone acetylation and increased histone H3 lysine 9 trimethylation, which are histone marks that are associated with transcriptional repression. dCas9-KRAB-mediated inhibition of HIV-1 transcription suggests that CRISPR can be engineered as a tool for block-and-lock strategies. The research presented here provides evidence of opioid-mediated modulation of HIV-1 latency reactivation in PWH with opioid dependency. Additionally, we show that HIV-1 reactivation can be suppressed by epigenetic remodeling of the HIV-1 promoter using a repurposed CRISPR/Cas9 system.
22

Rock Strength Testing of Drill Core Samples From Kiirunavaara Below Level 1365 / Berghållfasthetsprovning av borrkärnprover frånKiirunavaara under nivå 1365 i Kiruna, norra Sverige

Doulamis, Giorgios January 2022 (has links)
The geotechnical parameters of the different lithologies are of great importance regarding mining, infrastructures development and safety. The main aims of this thesis project are the evaluation of the previously acquired point load tests (PLT) data and the acquisition of a larger set for the various lithologies and alterations. In addition, the correlation to the Leeb Hardness test (LHT) method, and the determination of correlation factors (K) for estimating the uniaxial compressive strength (UCS) index from PLT data for various lithologies were evaluated. In total, 5236 previously PL tested samples, 1113 newly PL tested samples and 569 LHT measurements were obtained. The results showed that the highest values come from the footwall lithologies (Sp) ranging between 11-19 MPa, while the hanging wall lithologies (Qp) fall in range 10-14 MPa and the different ore types between 6-11 MPa. The correlation between PLT and LHT was poor, with the results completely overlapping for all country rock lithologies in the range 800-900 LHD, while the ore types fall in the range 600-700, and anhydrite at 500 LHD. On the other hand, the correlation factors K for the lithologies tested vary between 13-20 for the weaker and more altered rock types and 25-30 for the stronger ones, correlating well when compared to the actual UCS values found in the literature. In conclusion, it is evident that the LHT is not able to substitute the PLT as it captures different properties of the rock. The conversion from PLT to UCS gave rather accurate results, with slightly different correlation factors K for the tested lithologies.
23

Direct Infusion Lipidomics: Profiling the Lipidome of a Composite Tailings Reclamation Site

Hodgson, Paul A. 04 1900 (has links)
<p>The comprehensive analysis of intact lipids (called lipidomics) can provide information about the presence of microbial communities in an ecosystem and assist in understanding the biogeochemistry in that system. In previous work we had developed a method to determine the profiles of eight phospholipid classes in a soil microorganism by direct-infusion electrospray mass spectroscopy using tandem mass spectrometry. The work done in this study encompasses first the optimization of previous methodology for use with water and sediment samples containing low concentration of phospholipids and large amounts of organic contaminants and secondly the application of this method to the analysis of phospholipids within composite tailings and recycled process water using a triple quadrupole mass spectrometer to determine the intact lipids in the bacterial community. The results are presented illustrating the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) lipids present in composite tailing samples and recycled process water. This thesis begins with the optimization of a direct infusion mass spectrometry method, which allowed the analysis of intact phospholipids within both water and sediment samples. This method allows for high through-put analysis using both the separation afforded by neutral loss and precursor ion scanning modes and a database containing all possible adduct masses to identify and quantify unknown phospholipids. This method was then applied to water and sediment samples obtained from the Syncrude Sandhill Fen composite tailings site. This analysis discovered multiple differences within the water samples attributed to changes both in well temperature and the ongoing reclamation projects resulting in the change in phospholipid profiles. This thesis also outlines the shortcomings of the direct infusion lipidomics method when used for the analysis of complex samples such as composite tailings sediment samples. In summary, this thesis has demonstrated that direct infusion lipidomics can be successfully applied to the analysis of water samples and yield statistically significant differences within the microbial lipidome.</p> / Master of Science (MSc)
24

An experimental study on characterization of physical properties of ultramafic rocks and controls on evolution of fracture permeability during serpentinization at hydrothermal conditions

Farough, Aida 28 September 2015 (has links)
Serpentinization is a complex set of hydration reactions, where olivine and pyroxene are replaced by serpentine, magnetite, brucite, talc and carbonate minerals. Serpentinization reactions alter chemical, mechanical, magnetic, seismic, and hydraulic properties of the crust. To understand the complicated nature of serpentinization and the linkages between physical and chemical changes during the reactions, I performed flow-through laboratory experiments on cylindrically cored samples of ultramafic rocks. Each core had a well-mated through-going tensile fracture, to investigate evolution of fracture permeability during serpentinization. The samples were tested in a triaxial loading machine at an effective pressure of 30 MPa, and temperature of 260°C, simulating a depth of 2 km under hydrostatic conditions. Fracture permeability decreased by one to two orders of magnitude during the 200 to 340 hour experiments. Electron microprobe and SEM data indicated the formation of needle-shaped crystals of serpentine composition along the walls of the fracture, and chemical analyses of sampled pore fluids were consistent with dissolution of ferro-magnesian minerals. The rate of transformation of olivine to serpentine in a tensile fracture is calculated using the data on evolution of fracture permeability assuming the fracture permeability could be represented by parallel plates. Assuming the dissolution and precipitation reactions occur simultaneously; the rate of transformation at the beginning of the experiments was ~ 10-8-10-9 (mol/m2s) and decreased monotonically by about an order of magnitude towards the end of the experiment. Results show that dissolution and precipitation is the main mechanism contributing to the reduction in fracture aperture. The experimental results suggest that the fracture network in long-lived hydrothermal circulation systems may be sealed rapidly as a result of mineral precipitation, and generation of new permeability resulting from a combination of tectonic and crystallization-induced stresses may be required to maintain fluid circulation. Another set of flow through experiments were performed on intact samples of ultramafic rocks at room temperature and effective pressures of 10, 20 and 30 MPa to estimate the pressure dependency of intact permeability. Porosity and density measurements were also performed with the purpose of characterizing these properties of ultramafic rocks. The pressure dependency of the coefficient of matrix permeability of the ultramafic rock samples fell in the range of 0.05-0.14 MPa-1. Using porosity and permeability measurements, the ratio of interconnected porosity to total porosity was estimated to be small and the permeability of the samples was dominantly controlled by microcracks. Using the density and porosity measurements, the degree of alteration of samples was estimated. Samples with high density and pressure dependent permeability had a smaller degree of alteration than those with lower density and pressure dependency. / Ph. D.
25

Characterization of Microorganisms of Interest to Homeland Security and Public Health Utilizing Liquid Chromatography/Mass Spectrometry

Everley, Robert A. 01 January 2008 (has links)
Liquid chromatography/quadrupole time of flight mass spectrometry (LC/QTOF MS) utilizing electrospray ionization was employed to monitor protein expression in Escherichia coli and Shigella organisms. Automated charge state deconvolution, spectral subtraction and spectral mirroring were used to reveal subtle differences in the LC/MS data. Reproducible intact protein biomarkers were discovered based on their unique mass, retention time and relative intensity. These markers were implemented to differentiate closely related strain types, (e.g. two distinct isolates of E. coli O157:H7) and to correctly identify unknown pathogens. Notable, was the distinction of multiple serotypes of enterohaemorrhagic E. coli which cannot be distinguished by clinical manifestation alone. Additionally, speciation of Shigella was achieved, a task for which no commercial real-time polymerase chain reaction (PCR) primers exist. This method was subsequently applied to two pathogenic Clostridium species: C. difficile and C. perfringens. Due to the increased difficulty during lysis, two new lysis protocols were developed, and each extracted a distinct set of proteins (by both mass and retention time). Extracts from both lysis procedures were utilized to discover biomarkers useful for identification and characterization at the species and strain levels. These biomarkers were successfully implemented to identify unknowns during a blind study and would enhance serological and genetic approaches by serving as new targets for detection. Two sets of the C. perfringens isolates that were deemed 100% similar by the gold standard for strain differentiation, pulsed-field gel electrophoresis (PFGE), were distinguished using LC/MS, demonstrating the high specificity of this approach. The final part of this work demonstrated the application of ultra performance liquid chromatography (UPLC) to this project to improve the throughput of the method. Given that numerous small molecule applications of UPLC have been published, efforts were made to examine the potential of UPLC to enhance the separation of intact proteins. Beginning with typically employed conditions, column temperature and organic solvent were optimized followed by an HPLC vs. UPLC comparison. When applied to a mixture of ten protein standards, the optimized UPLC method yielded improved chromatographic resolution, enhanced sensitivity, and a three-fold increase in throughput. Application of this method to cell lysate analysis demonstrated no compromise in chromatographic or mass spectral data quality; a reduction in run time from 75 minutes to 25 minutes was achieved.
26

Avaliação da concentração sérica de paratormônio intacto em gatos com doença renal crônica / Intact serum parathyroid hormone evaluation in cats with chronic kidney disease

Giovaninni, Luciano Henrique 30 September 2010 (has links)
A doença renal crônica (DRC) evolui de forma progressiva e o hiperparatiroidismo secundário renal (HPTSR) é uma das importantes alterações que causa a perda adicional de néfrons e o comprometimento de varios sistemas; o paratormônio (PTH) é considerado como uma importante toxina urêmica. A avaliação do PTH sérico em felinos com DRC pode trazer informações para o melhor entendimento da fisiopatologia do HPTSR, suscitando possíveis medidas terapêuticas. Observou-se que gatos com DRC (n=40) apresentaram aumento significante (p < 0,05) da concentração sérica de paratormônio intacto (PTHi) quando comparados a gatos clinicamente normais (n=21; grupo controle). Quanto a avaliação do PTHi nos subgrupos de DRC (ESTÁGIOS II, III e IV de evolução da afecção, classificados segundo o International Renal Interest Society IRIS), constatou-se diferença significante entre os gatos dos ESTÁGIOS III e IV com os gatos clinicamente normais; em relação ao ESTÁGIO II, apesar de não ter sido observada diferença significante, a maioria dos gatos apresentou aumento da concentração sérica de PTHi (> 60,2 pg/mL). Em relação aos valores das concentrações séricas de fósforo e de cálcio iônico, detectou-se a tendência de concentrações séricas progressivamente maiores de fósforo (hiperfosfatemia) nos estágios mais avançados da doença (frequências de 16,7%, 27,3% e 100% nos ESTÁGIOS II, III e IV, respectivamente); inversamente, as concentrações séricas de cálcio iônico foram progressivamente menores (respectivamente, frequência de hipocalcemia de 8,3%, 9,1% e 66,7%). Constatou-se diferença significante quanto as concentração de bicarbonato plasmático entre os gatos clinicamente normais e os gatos com DRC (acidose metabólica em 42,5% dos casos), como também entre os gatos clinicamente normais e os animais dos subgrupos DRC ESTÁGIOS II e III (bicarbonato plasmático < 16,8 mmol/L observado em 40,9% e 33,3%, respectivamente). Não foram detectadas diferenças significantes quanto as concentrações séricas de cálcio total ou de pH sanguíneo nas comparações múltiplas. Em relação aos valores da multiplicação entre as concentrações séricas de cálcio total e de fósforo, a análise estatística demonstrou resultados similares àqueles da análise das concentrações séricas de fósforo. Sugere-se que o estímulo para o aumento da concentração sérica de PTHi, e o consequente HPTSR, observado nos gatos com DRC no estágio IV, tenha decorrido da hipocalcemia iônica e da hiperfosfatemia apresentadas por estes animais, ativando a regulação pela paratireóide. Quanto aos gatos nos estágios II e III da DRC, outros fatores, além da hipocalcemia e da hiperfosfatemia, devem estar envolvidos no aumento da síntese de PTHi, sugerindo-se a necessidade de investigação, por exemplo, das concentrações séricas de calcitriol; ainda no subgrupo ESTÁGIO II, a hipercalcemia iônica observada em 50% dos gatos sugere a possibilidade do envolvimento da acidose metabólica, que poderia comprometer a fração ionizada do cálcio. A correlação positiva observada entre o fósforo e o PTHi sugere a possibilidade de avaliação indireta de HPTSR pela determinação do fósforo sérico; entretanto nos gatos nos estágios II e III da DRC, esta avaliação indireta não se mostrou adequada, pois observou-se concomitantemente normofosfatemia e aumento do PTHi, indicando-se a necessidade da determinação do PTHi para avaliação do HPTSR nesses estágios da DRC em gatos. / Chronic kidney disease (CKD) develops gradually, causing several changes and renal secondary hyperparathyroidism (RSHPTH) is one of those alterations, which, besides causing loss of additional nephrons, increases the morbidity and mortality due to the action of parathyroid hormone (PTH) as an important uremic toxin. Evaluation of serum PTH in cats with CKD may add information for the better understanding of RSHPTH pathophysiology, arising possible therapeutic procedures. Cats with CKD (n = 40) showed significant increase (p < 0.05) in serum intact parathyroid hormone (iPTH) as compared with clinically normal cats (n = 21, control group). In subgroups of CKD (STAGES II, III and IV of CKD, classified as recommended by International Renal Interest Society - IRIS), significant difference was observed between clinically normal cats and cats with CKD in STAGES III and IV; in reference to the STAGE II, although no significant difference was observed, most of these cats showed an increase in serum iPTH (> 60.2 pg / mL). In relation to values of phosphorus and ionized calcium serum concentrations, a trend of progressively higher serum concentrations of phosphorus (hyperphosphatemia) was detected in the late stages of the disease (16.7%, 27.3% and 100% in STAGES II, III and IV, respectively), in opposite, serum concentrations of ionized calcium progressively decreased (respectively, ionized hypocalcemia, 8.3%, 9.1% and 66.7%). Plasma bicarbonate concentrations were significant different between clinically normal cats and cats with CKD (metabolic acidosis observed in 42.5% of the cases), and between clinically normal cats and cats with CKD STAGES II and III (plasma bicarbonate < 16.8 mmol/L observed in 40.9% and 33.3% of the cases, respectively). No significant differences were detected for serum concentrations of total calcium and blood pH, in multiple comparisons analysis. In relation to the values of serum concentrations of calcium and phosphorus product, the results were similar to those obtained from phosphorus serum concentrations evaluation. The results suggested that the stimulus for the increase in serum iPTH, and follow development of RSHPTH, observed in cats with CKD STAGE IV, was in consequence of ionized hypocalcemia and hyperphosphatemia, enabling the regulation by the parathyroid. However, for the cats in STAGES II and III of CKD, other factors, beyond hypocalcemia and hyperphosphatemia, may be involved to cause the increase of iPTH synthesis, and calcitriol serum concentrations must be investigated; in cats with DRC STAGE II, 50% of the cases presented ionized hypercalcemia, suggesting the influence of metabolic acidosis in ionized calcium fraction. The correlation observed between serum phosphorus and iPTH may suggest the possibility of indirect evaluation of RSHPTH by means of phosphorus serum concentration; however in cats with DRC, STAGES II and III, this indirect assessment may not be adequate as normal serum levels of phosphorus as well as increased serum iPTH were observed in those cats, indicating the need for the determination of serum iPTH to evaluate RSHPTH.
27

Neuroendocrine mechanisms of natural reproductive aging in female rats

Kermath, Bailey Ann 29 January 2014 (has links)
Female reproductive senescence is widespread among mammalian species, but menopause is limited to species with menstrual cycles. While hormonal changes at menopause have profound impacts in the lives of women at middle age, the complex mechanisms underlying this process remain obscure. All three levels of the hypothalamic-pituitary-gonadal (HPG) axis are involved in reproductive aging, and evidence highlights a critical role for the dysregulation of gonadotropin-releasing hormone (GnRH) neurons, the hypothalamic cells that drive reproductive function. To investigate neuroendocrine mechanisms that may initiate and perpetuate reproductive decline at each step in the transition to acyclicity, I utilized an ovarian-intact middle-aged female rat model of natural reproductive senescence. These studies focused on three hypothalamic nuclei that are known to control GnRH activity: the anteroventral periventricular nucleus (AVPV), the site of positive hormone feedback onto GnRH neurons; the arcuate nucleus (ARC), the site of negative feedback; and the median eminence (ME), the site of GnRH release, with the following specific aims: 1) Characterize neuroendocrine gene and protein expression in female rats throughout the natural transition to acyclicity; 2) Determine the effects of chronic N-methyl-D-asparate receptor subunit 2b (NMDAR-NR2b) inhibition in acyclic females; and 3) Examine neuroendocrine gene expression during premature reproductive senescence after perturbation of the HPG axis. The results of these studies identified novel molecular and cellular changes with age and reproductive cycle status in the ARC and ME, two regions that are underappreciated for their roles in reproductive senescence. Surprisingly, few molecular targets were identified in the AVPV, a region that is much better-studied in this context. In the ME and ARC, I found changes in transcription factors and evidence of altered hormone feedback via changes in sex steroid hormone receptors and enzyme expression with reproductive aging. I also discovered decreased expression of genes for the excitatory neuropeptides, kisspeptin and neurokinin B, as well as decreased percentage of kisspeptin immunoreactive cells and their co-expression with estrogen receptor alpha in the ARC. And finally, in the ME, neurotrophic factor expression was changed with age, and the presence and phosphorylation state of the NR2b subunit of the NMDA receptor contributes to a greater inhibitory tone with acyclicity. Together these studies have identified novel pathways, especially in the ARC and ME, that are related to reproductive decline. Furthermore, changes in the hypothalamic neural and glial network of neurotransmitters, neuropeptides, hormone receptors and other transcription factors are likely contributing to altered responses to hormonal feedback and decreased excitatory drive for GnRH release. / text
28

Avaliação da concentração sérica de paratormônio intacto em gatos com doença renal crônica / Intact serum parathyroid hormone evaluation in cats with chronic kidney disease

Luciano Henrique Giovaninni 30 September 2010 (has links)
A doença renal crônica (DRC) evolui de forma progressiva e o hiperparatiroidismo secundário renal (HPTSR) é uma das importantes alterações que causa a perda adicional de néfrons e o comprometimento de varios sistemas; o paratormônio (PTH) é considerado como uma importante toxina urêmica. A avaliação do PTH sérico em felinos com DRC pode trazer informações para o melhor entendimento da fisiopatologia do HPTSR, suscitando possíveis medidas terapêuticas. Observou-se que gatos com DRC (n=40) apresentaram aumento significante (p < 0,05) da concentração sérica de paratormônio intacto (PTHi) quando comparados a gatos clinicamente normais (n=21; grupo controle). Quanto a avaliação do PTHi nos subgrupos de DRC (ESTÁGIOS II, III e IV de evolução da afecção, classificados segundo o International Renal Interest Society IRIS), constatou-se diferença significante entre os gatos dos ESTÁGIOS III e IV com os gatos clinicamente normais; em relação ao ESTÁGIO II, apesar de não ter sido observada diferença significante, a maioria dos gatos apresentou aumento da concentração sérica de PTHi (> 60,2 pg/mL). Em relação aos valores das concentrações séricas de fósforo e de cálcio iônico, detectou-se a tendência de concentrações séricas progressivamente maiores de fósforo (hiperfosfatemia) nos estágios mais avançados da doença (frequências de 16,7%, 27,3% e 100% nos ESTÁGIOS II, III e IV, respectivamente); inversamente, as concentrações séricas de cálcio iônico foram progressivamente menores (respectivamente, frequência de hipocalcemia de 8,3%, 9,1% e 66,7%). Constatou-se diferença significante quanto as concentração de bicarbonato plasmático entre os gatos clinicamente normais e os gatos com DRC (acidose metabólica em 42,5% dos casos), como também entre os gatos clinicamente normais e os animais dos subgrupos DRC ESTÁGIOS II e III (bicarbonato plasmático < 16,8 mmol/L observado em 40,9% e 33,3%, respectivamente). Não foram detectadas diferenças significantes quanto as concentrações séricas de cálcio total ou de pH sanguíneo nas comparações múltiplas. Em relação aos valores da multiplicação entre as concentrações séricas de cálcio total e de fósforo, a análise estatística demonstrou resultados similares àqueles da análise das concentrações séricas de fósforo. Sugere-se que o estímulo para o aumento da concentração sérica de PTHi, e o consequente HPTSR, observado nos gatos com DRC no estágio IV, tenha decorrido da hipocalcemia iônica e da hiperfosfatemia apresentadas por estes animais, ativando a regulação pela paratireóide. Quanto aos gatos nos estágios II e III da DRC, outros fatores, além da hipocalcemia e da hiperfosfatemia, devem estar envolvidos no aumento da síntese de PTHi, sugerindo-se a necessidade de investigação, por exemplo, das concentrações séricas de calcitriol; ainda no subgrupo ESTÁGIO II, a hipercalcemia iônica observada em 50% dos gatos sugere a possibilidade do envolvimento da acidose metabólica, que poderia comprometer a fração ionizada do cálcio. A correlação positiva observada entre o fósforo e o PTHi sugere a possibilidade de avaliação indireta de HPTSR pela determinação do fósforo sérico; entretanto nos gatos nos estágios II e III da DRC, esta avaliação indireta não se mostrou adequada, pois observou-se concomitantemente normofosfatemia e aumento do PTHi, indicando-se a necessidade da determinação do PTHi para avaliação do HPTSR nesses estágios da DRC em gatos. / Chronic kidney disease (CKD) develops gradually, causing several changes and renal secondary hyperparathyroidism (RSHPTH) is one of those alterations, which, besides causing loss of additional nephrons, increases the morbidity and mortality due to the action of parathyroid hormone (PTH) as an important uremic toxin. Evaluation of serum PTH in cats with CKD may add information for the better understanding of RSHPTH pathophysiology, arising possible therapeutic procedures. Cats with CKD (n = 40) showed significant increase (p < 0.05) in serum intact parathyroid hormone (iPTH) as compared with clinically normal cats (n = 21, control group). In subgroups of CKD (STAGES II, III and IV of CKD, classified as recommended by International Renal Interest Society - IRIS), significant difference was observed between clinically normal cats and cats with CKD in STAGES III and IV; in reference to the STAGE II, although no significant difference was observed, most of these cats showed an increase in serum iPTH (> 60.2 pg / mL). In relation to values of phosphorus and ionized calcium serum concentrations, a trend of progressively higher serum concentrations of phosphorus (hyperphosphatemia) was detected in the late stages of the disease (16.7%, 27.3% and 100% in STAGES II, III and IV, respectively), in opposite, serum concentrations of ionized calcium progressively decreased (respectively, ionized hypocalcemia, 8.3%, 9.1% and 66.7%). Plasma bicarbonate concentrations were significant different between clinically normal cats and cats with CKD (metabolic acidosis observed in 42.5% of the cases), and between clinically normal cats and cats with CKD STAGES II and III (plasma bicarbonate < 16.8 mmol/L observed in 40.9% and 33.3% of the cases, respectively). No significant differences were detected for serum concentrations of total calcium and blood pH, in multiple comparisons analysis. In relation to the values of serum concentrations of calcium and phosphorus product, the results were similar to those obtained from phosphorus serum concentrations evaluation. The results suggested that the stimulus for the increase in serum iPTH, and follow development of RSHPTH, observed in cats with CKD STAGE IV, was in consequence of ionized hypocalcemia and hyperphosphatemia, enabling the regulation by the parathyroid. However, for the cats in STAGES II and III of CKD, other factors, beyond hypocalcemia and hyperphosphatemia, may be involved to cause the increase of iPTH synthesis, and calcitriol serum concentrations must be investigated; in cats with DRC STAGE II, 50% of the cases presented ionized hypercalcemia, suggesting the influence of metabolic acidosis in ionized calcium fraction. The correlation observed between serum phosphorus and iPTH may suggest the possibility of indirect evaluation of RSHPTH by means of phosphorus serum concentration; however in cats with DRC, STAGES II and III, this indirect assessment may not be adequate as normal serum levels of phosphorus as well as increased serum iPTH were observed in those cats, indicating the need for the determination of serum iPTH to evaluate RSHPTH.
29

Determinação de parâmetros físico-químicos em laranjas Valência por métodos não-destrutivos / Determination of physico-chemical parameters in oranges Valencia for methods non-destructive

Borba, Karla Rodrigues [UNESP] 20 July 2016 (has links)
Submitted by KARLA RODRIGUES BORBA null (borbakr@gmail.com) on 2016-09-20T23:38:38Z No. of bitstreams: 1 Dissertação Karla Borba FINAL.pdf: 1640601 bytes, checksum: d248911e99e0c55bcfeeb7cf07a3ab49 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-09-22T20:31:44Z (GMT) No. of bitstreams: 1 borba_kr_me_arafcf.pdf: 1640601 bytes, checksum: d248911e99e0c55bcfeeb7cf07a3ab49 (MD5) / Made available in DSpace on 2016-09-22T20:31:44Z (GMT). No. of bitstreams: 1 borba_kr_me_arafcf.pdf: 1640601 bytes, checksum: d248911e99e0c55bcfeeb7cf07a3ab49 (MD5) Previous issue date: 2016-07-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivo: Alguns atributos em sua composição química e física, como teor de sólidos solúveis (SST), pH (potencial hidrogeniônico), ácidos orgânicos, açúcares e cor são utilizados como parâmetros na aferição da qualidade de frutas. Os métodos utilizados, nos dias atuais, para a análise da qualidade destes produtos são invasivos, que demandam tempo, muitas amostras, reagentes e geram resíduos. Técnicas não destrutivas, como a espectroscopia no infravermelho e de ressonância magnética nuclear, têm sido propostas para avaliar qualidade em frutas e hortaliças. Este projeto teve como objetivo: desenvolver um modelo de calibração, a partir da espectroscopia de infravermelho de médio e próximo, e ressonância magnética com o auxílio das ferramentas quimiométricas PCA (análises de componentes principais) e PLS (Regressão em mínimos quadrados parciais) com a utilização do programa computacional Pirouette versão 4.5, para estimar parâmetros físico-químicos da qualidade de laranjas da variedade ‘Valência’. Métodos: Foram coletadas um total de 450 laranjas de cultivo comercial no interior de São Paulo, transportadas para a Embrapa Instrumentação, São Carlos, SP e em laboratório foram selecionadas, higienizadas e sanitizadas. Em seguida foram realizadas análises espectroscópicas de infravermelho médio (MIR) e próximo (NIR) e de ressonância magnética nuclear (RMN). Logo após realizadas as análises não destrutivas as laranjas foram analisadas com métodos de referência para os parâmetros de qualidade. Os sinais espectroscópicos foram processados e os modelos de predição foram construídos. Com os sinais de NIR e MIR foram desenvolvidos modelos PLS para determinação de: SST, pH, massa fresca, vitamina C, ácido cítrico e açucares. Para os sinais de decaimento de RMN foram construídos modelos para SST, pH e massa fresca. Resultados: Para a predição de SST o modelo PLS – NIR mostrou melhor resultado, com SEP 0,74 °BRIX e coeficiente de correlação de 0,75. O parâmetro que apresentou melhor aplicação com a técnica de RMN-dt foi para determinação de massa fresca, com SEP 21,41 gramas e r = 0,82. A determinação do pH foi mais precisa com o modelo PLS-MIR, onde observou-se SEP de 0,20 e r = 0,86. Para a predição de vitamina C e ácido cítrico tanto o NIR quanto o MIR resultaram em modelos com aplicabilidade. O modelo mais preciso foi o desenvolvido com sinas de MIR, com coeficiente de correlação de Pearson (r) de 0,81 e erro quadrático médio de predição (RMESP) de 7,51 para vitamina C e 0,82 e 3,36 para ácido cítrico. Em relação a predição de açúcares o NIR não resultou em modelos precisos. Todavia, a utilização de MIR para a predição de sacarose, glicose e açúcares totais apresentaram baixos erros de predição 11,69, 7,79 e 24,28 (g L-1) e coeficientes de correlação de forte a moderado. Conclusão: A aplicação de espectroscopia na determinação de parâmetros de qualidade mostrou-se uma possível alternativa na análise de qualidade de laranjas sem que seja necessária a destruição das amostras. / Objective: Some attributes in their chemical and physical composition, as soluble solids content (SSC), pH (hydrogen potential), organic acids, sugars and color are used as parameters in measuring the quality of fruit. The methods used nowadays, to analyze the quality of these products are invasive, requiring time, many samples, reagents and generate waste. Nondestructive techniques such as infrared spectroscopy and nuclear magnetic resonance, have been proposed to evaluate quality in fruits and vegetables because they allow rapid implementation of measurements without sample preparation. This project aimed to: develop a calibration model by near ande mid-infrared spectroscopy and nuclear magnetic resonance with the aid of chemometric tools PCA (principal component analysis) and PLS (regression in partial least squares) with use of the computer program Pirouette version 4.5, to estimate physical-chemical parameters of quality oranges from ‘Valencia’ variety. Methodology: A total of 450 commercial cultivation oranges were collected in São Paulo, transported to Embrapa Instrumentation, São Carlos/SP, and in laboratory were selected, cleaned and sanitized. Then spectroscopic analysis near (NIR) and mid-infrared (MIR), and nuclear magnetic resonance (NMR) were made. After performed the non-destructive analysis, the oranges were analyzed with reference methods for quality parameters. Spectroscopic data were processed and prediction models were developed to determinith MIR and NIR signal PLS models were developed to determine SSC, pH, fresh weight, vitamin C, citric acid and sugars. For the NMR signal decay models were constructed to SSC, pH and fresh weight. Results: For SSC prediction PLS model - NIR showed better results, with RMSEP (mean squared prediction error) 0.74 °BRIX and 0.75 correlation coefficient. The parameter that showed better application with DT- NMR technique was to determine fresh weight with RMSEP 21.41 grams and r = 0.82. The determination of pH was more accurate with the PLS-MIR model where there was RMSEP 0.20 and r = 0.86. For the prediction of vitamin C and citric acid as both the MIR NIR models resulted in applicability. The most accurate model was developed with MIR, with Pearson's correlation coefficient (r) of 0.81 and RMESP of 7.51 for vitamin C and 0.82 and 3.36 for Citric acid. Regarding the prediction of sugars NIR did not result in accurate models. However, the use of MIR for the prediction of sucrose, glucose and total sugars were low prediction errors 11.69, 7.79 and 24.28 (g L-1 ) and strong correlation coefficients to moderate.Conclusion: The application of spectroscopy to determining quality parameters proved to be a viable alternative in quality analysis oranges without destruction of samples.
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Application of Flow Cytometry for Slow Sand Filters

Helstad, Amanda January 2019 (has links)
This project investigated the bacteria in water entering and leaving the slow sand filters at Ringsjö Water Works using flow cytometry. The purpose was to explore the possibility of utilising flow cytometry as a monitoring method for optimising water production using slow sand filters. Data describing the bacterial community in water was collected over seven weeks and analysed with FlowJo, flow cytometric image comparison and Minitab. The total cell count, intact cell count and the percentage of high nucleic acid bacteria were analysed. These parameters were highly dependent on scraping events, water entering the filters and season. The results indicated that flow cytometry has great potential for use as a monitoring method, although more data should be collected to establish expected trends and secure baseline values for routine comparisons. / <p>Fördröjning av publikation fram till 31 december 2020.</p>

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