• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1348
  • 730
  • 389
  • 262
  • 99
  • 53
  • 49
  • 31
  • 21
  • 17
  • 14
  • 13
  • 7
  • 4
  • 4
  • Tagged with
  • 3279
  • 1676
  • 881
  • 844
  • 503
  • 402
  • 360
  • 349
  • 314
  • 262
  • 255
  • 230
  • 222
  • 217
  • 198
  • 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.
11

Gene expression profiling in Philadelphia positive acute lymphoblastic leukaemia treated with Imatinib -- a novel role of PKC epsilon signalling

Loi, To Ha, Clinical School - St Vincent's Hospital, Faculty of Medicine, UNSW January 2008 (has links)
Philadelphia positive (Ph+) Acute Lymphoblastic Leukaemia (ALL) is characterised by the presence of the BCR-ABL fusion gene, which encodes a protein tyrosine kinase with aberrant activity. Imatinib, a chemical Bcr-Abl inhibitor, is rarely effective in Ph+ ALL patients as a single agent. In this study, insight into molecular and signalling changes occurring in Ph+ ALL during Imatinib therapy were investigated using cDNA microarrays. An optimal microarray assay was established to examine the gene expression changes in leukaemic cells from Ph+ ALL patients treated with Imatinib. Over 500 genes with ≥1.5-fold up- or down-regulation were identified. Based on gene ontology and novelty to Bcr-Abl signalling, six genes were selected and expression changes in five of these genes (PKCε, PINK1, SPRY2, ATF4 and PECAM1) confirmed by real time RT-PCR in Imatinib treated primary Ph+ ALL cells or the SUP-B15 cell line. The functional role of Protein Kinase C epsilon (PKCε) in response to Imatinib was further investigated using the Ph+ lymphoid and myeloid cell lines, SUP-B15 and K562. Detection of Imatinib-induced apoptosis by annexin V and PI staining demonstrated that SUP-B15 cells were less sensitive to Imatinib compared to K562 cells. PKCε mRNA was 50-fold higher in Ph+ ALL cells than Ph+ myeloid cells. In SUP-B15 cells, Imatinib upregulated PKCε mRNA but the protein was reduced by proteolytic cleavage. Inhibition of caspases showed that this cleaved product was not required for Imatinib induced-apoptosis. The treatment of SUP-B15 and primary Ph+ ALL cells with TAT-εV1-2 peptide, a specific inhibitor of PKCε, increased Imatinib-induced apoptosis. While the forced overexpression of PKCε in K562 cells reduced Imatinib-induced apoptosis. This increased expression of PKCε was associated with the increase of survival and anti-apoptotic proteins, Akt and Bcl-2. In summary, Gene expression profiling of Ph+ ALL cells during Imatinib therapy identified PKCε as an Imatinib responsive gene. A novel role of PKCε in Ph+ ALL response to imatinib is proposed. Experimental data presented in this thesis indicate that PKCε mediates pro-survival/anti-apoptosis signals in Ph+ ALL thereby reducing Imatinib-induced death. Thus, targeting PKCε during Imatinib therapy may be beneficial for the future treatment of Ph+ ALL.
12

Rapid on-line Glycogen measurement and prediction of ultimate pH in slaughter beef

Lomiwes, Dominic January 2008 (has links)
The rapid determination of glycogen on indicator muscle immediately after slaughter is advantageous as it permits the prediction of a muscle’s ultimate pH (pHu) and allows the identification of high pHu meat carcasses by extrapolation. This thesis examines the development of two rapid glycogen determination methods. The first aim of this thesis was to find a new glucometer to replace the Bayer ESPRIT™ (Bayer) glucometer currently used in the Rapid pH (RpH) method. Roche’s Accuchek® Advantage II (Accuchek) and Abbott’s Medisense Optium™ (Medisense) glucometers were compared. Accuchek measurements exhibited a positive linear relationship in glucose standards made with water, RpH buffer and glucose spiked meat/buffer slurries ranging from 0 to 500 mg dL-1 (r2 = 0.999, 0.998 and 0.995 respectively). Medisense also exhibited a strong positive relationship for glucose standards made with water and RpH buffer; however, a non-linear trend in spiked meat slurries was observed. The second aim of this thesis was to explore the calibration of the KES K201 (KES Analysis Inc., NY, USA) near-infrared (NIR) diode array spectrometer to measure glycogen and pH at approximately 45 minutes after slaughter (pH45), and to predict pHu in pre-rigor M. longissimus dorsi (LD) from beef. This first required finding a reference method to calibrate against the NIR instrument. The RpH, Iodine and Bergmeyer methods were compared. Analysis of glycogen in replicate samples of three beef LD muscles at timepoints post-mortem (1, 4, 9 and 20 hours) was conducted. No significant difference in glycogen concentration was found between an enzymatic and an iodine based colorimetric method at each timepoint; however, the Iodine method was more consistent than the Bergmeyer method at all timepoints. Glucose measurements from the RpH method were consistent; however the pattern of glycogen decline at increasing timepoints post-mortem did not correspond with existing published studies. NIR spectra (538 to 1677 nm) of LD muscles from steers (n = 47), cows (n = 28) and bulls (n = 20) routinely slaughtered in a commercial abattoir were collected on-line approximately 45 minutes after slaughter. Poor results were obtained for Partial Least Squares (PLS) models generated from the mean reflectance spectra of each animal to measure glycogen and pH45, and predict pHu (r2 = 0.23, 0.37 and 0.20 respectively). A high mean square error of prediction (MSEP) for glycogen was also obtained (7.75). Validation of qualitative models generated with Generalised Partial Least Squares regression (GPLS) found that the optimum model was able to correctly categorise only 42% of high pHu samples with the remaining portion being wrongly classified as normal pHu meat. When the effect of gender was removed, only 21% of high pHu carcasses were correctly categorised. Exploratory analysis of the absorbance spectra of the LD muscles showed that a group composed predominantly of steers had a significantly lower pH45 than other existing groups. Further work is recommended for NIR to be successfully utilised on-line to measure glycogen or predict pHu in pre-rigor carcasses.
13

Implication des cotransporteurs cation-chlore dans le transport de l'ammonium et la régulation du pH /

Bergeron, Marc. January 2003 (has links)
Thèse (M.Sc.)--Université Laval, 2003. / Bibliogr.: f. 83-96. Publié aussi en version électronique.
14

Conduite optimale d'une cascade de réacteurs chimiques par commande hiérarchisée.

Pons, Marie-Noëlle. January 1900 (has links)
Th. doct.-ing.--Nancy, I.N.P.L., 1980.
15

Vliv hygroskopických přísad na vodní aktivitu potravin

Horáková, Martina January 2013 (has links)
No description available.
16

Sledování kvalitativních parametrů syrovátky

Kaiseršotová, Dana January 2013 (has links)
No description available.
17

¹⁹F NMR sensors for the measurement of pH in biological systems

Jones, Brian George January 1995 (has links)
No description available.
18

Variáveis que influenciam a estabilidade da alvura de polpas branqueadas em sequências ECF / Variables that influence the stability of the whiteness of bleached pulps in ECF sequences

Camargo, Sâmique Kyene de Carvalho Araújo [UNESP] 21 February 2017 (has links)
Submitted by Samique Kyene de Carvalho Araujo Camargo null (samiquekyene@hotmail.com) on 2017-04-16T19:19:16Z No. of bitstreams: 1 dissertacaoversaofinal2.pdf: 1378540 bytes, checksum: 81cd59c1f012a91616b94f76446b6c66 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-18T17:41:00Z (GMT) No. of bitstreams: 1 camargo_skca_me_guara.pdf: 1378540 bytes, checksum: 81cd59c1f012a91616b94f76446b6c66 (MD5) / Made available in DSpace on 2017-04-18T17:41:00Z (GMT). No. of bitstreams: 1 camargo_skca_me_guara.pdf: 1378540 bytes, checksum: 81cd59c1f012a91616b94f76446b6c66 (MD5) Previous issue date: 2017-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O branqueamento objetiva a remoção de compostos que dão cor à polpa: lignina, extrativos, grupos carbonilas e carboxilas, complexo lignina carboidrato (LCC’s) e metais, para atingir a alvura mínima de 90± 0,5% ISO, exigida para comercialização da polpa e esta deve se manter estável em todo processo que compreende o transporte, manuseio e armazenamento, até o consumidor final. A utilização de diferentes reagentes de branqueamento efetiva a melhor eficiência na remoção destes compostos e, consequentemente, melhoram a estabilidade da alvura. O objetivo deste trabalho é avaliar o efeito das diferentes sequências de branqueamento na remoção dos grupos cromóforos, especialmente dos grupos carbonilas, minimizando assim a reversão de alvura. Para isso utilizou-se a espectroscopia na região do infravermelho. Também foi avaliado o efeito do pH nos estágios finais de branqueamento na estabilidade da alvura. Os experimentos foram realizados no Laboratório de Celulose da Unesp de Itapeva, onde foi efetuado o branqueamento das polpas de celulose deslignificada com oxigênio em sacos de polietileno, e para controle da temperatura utilizou-se o banho termostatizado. As sequências de branqueamento estudadas foram: D0(E+P)D1D2, AHTD0(E+P)D1D2, AHTD0(E+P)D1P, AHTD0(PO)D1, e AHTD0(PO), após o branqueamento foram efetuadas as análises de alvura, viscosidade e reversão de alvura. O efeito do pH na estabilidade da alvura pôde ser observado variando o pH do estágio final na faixa de 3 a 10 e efetuando a reversão induzida. A análise por espectroscopia na região do infravermelho comprova a eficiência dos reagentes na remoção dos grupos carbonilas, pois com a utilização do peróxido de hidrogênio nos estágios P final e PO houve diminuição da intensidade da banda de absorção na região do infravermelho destes grupos. Pôde-se observar com este estudo que a hidrólise ácida melhorou a alvura e sua estabilidade, e proporcionou uma economia na quantidade de reagente como cloro. A substituição do estágio final com dióxido de cloro por peróxido de hidrogênio proporcionou uma maior alvura, menor reversão de alvura e consumo de reagente como cloro, no entanto, ocasionou queda na viscosidade. A utilização de peróxido de hidrogênio pressurizado com oxigênio trouxe melhor resultado de reversão de alvura, mas menor viscosidade, tanto no estágio final, como intermediário. Neste último, houve economia na quantidade de reagente como cloro utilizado. / The bleaching process aims at the removal of compounds that give color to the pulp: lignin, extractives, carbonyl and carboxyl groups, lignin carbohydrate complex (LCC's) and metals, in order to reach the minimum whiteness of 90 ± 0.5% ISO, required for the commercialization of pulp And it must remain stable throughout the process, including transportation, handling and storage, to the final consumer. The use of different effective bleaching reagents gives better efficiency in the removal of these compounds and, consequently, enhances the brightness stability. The objective of this work is to evaluate the effect of the different bleaching sequences on the removal of the chromophore groups, especially the carbonyl groups, thus minimizing the reversal of whiteness. And, for that, spectroscopy was used in the infrared region. The effect of pH in the final stages of bleaching on brightness stability was also evaluated. The experiments were carried out at the Pulp Laboratory of Unesp de Itapeva, where the pulps of cellulose pulp were delignified with oxygen in polyethylene bags and the thermostated bath was used to control the temperature. The bleaching sequences studied were D0(E+P)D1D2, AHTD0(E+P)D1D2, AHTD0(E+P)D1P, AHTD0(PO)D1, and AHTD0(PO). After bleaching, of whiteness, viscosity and reversal of whiteness. The effect of pH on the brightness stability could be observed by varying the pH of the final stage in the range of 3 to 10 and effecting the induced reversal. The analysis by infrared spectroscopy proves the efficiency of the reagents in the removal of carbonyl groups, because with the use of hydrogen peroxide in the final stages P and PO there was a decrease in the intensity of the absorption band in the infrared region of these groups. It could be seen from this study that acid hydrolysis improved the brightness and stability, and provided savings in the amount of reactant as chlorine. The substitution of the final stage with chlorine dioxide by hydrogen peroxide provided a greater brightness, less reversion of brightness and consumption of reagent as chlorine, however, caused a drop in viscosity. The use of pressurized hydrogen peroxide with oxygen brought better blast reversion results, but lower viscosity, both in the final and intermediate stages. In the latter, there was savings in the amount of reagent such as chlorine used.
19

Avaliação do pH da saliva e da saburra lingual antes e após a utilização de soluções enxaguantes orais e sua relação com parâmetros de halitose / Evaluation of saliva and tongue coat pH before and after use of mouthwashes and relationship with parameters of halitosis

Tolentino, Elen de Souza 13 March 2009 (has links)
A relação entre halitose, pH da saliva e da saburra lingual frente ao uso de enxaguantes orais ainda não é totalmente conhecido. O objetivo deste estudo foi avaliar o pH da saliva e da saburra lingual em pacientes com saúde oral íntegra e halitose fisiológica através de um pHmetro analógico e um digital e de fitas indicadoras de pH, antes e imediatamente após utilização de diferentes enxaguantes orais e 30 minutos após o bochecho; avaliar o pH dos diferentes anti-sépticos; avaliar se há diferença nas medições do pH entre os pHmetros analógico e digital; avaliar as opiniões dos pacientes em relação ao enxaguante utilizado e relacionar as possíveis alterações do pH a parâmetros de halitose. Foram avaliados 50 pacientes divididos em 5 grupos, com bochechos de 5 diferentes soluções clorito de cetilpiridínio associado ao cloreto de sódio (Saúde Bucal®), Triclosan (Colgate Total Plax®), solução enzimática (Biotène Mouthwash®), óleo essencial (Listerine®) e água destilada (placebo). Os pacientes foram submetidos a duas consultas, sendo que a segunda ocorreu no período da manhã, em jejum. Na primeira, foi realizado exame clínico; na segunda a coleta da saliva, análise do pH e aplicação do questionário. Os resultados foram analisados utilizando-se o teste de análise de variância a dois critérios, teste t pareado e teste de Tukey (p<0,05), onde se observou que os enxaguantes Colgate Total Plax® e Listerine® aumentaram o pH da saliva imediatamente após o bochecho e o Biotène Mouthwash® diminuiu o pH da saliva e da saburra lingual. Pôde-se observar também que as quatro marcas comerciais de soluções para bochecho testadas apresentaram pH ácido e que o pHmetro analógico forneceu uma média de valores maiores que o pHmetro digital. Os enxaguantes de maior aceitação pela população estudada foram o Saúde Bucal® e o Biotène Mouthwash®. / The relationship between halitosis, saliva and tongue coat pH front by use of mouthwashes is not yet totally known. The aim of this work was to evaluate saliva and tongue coat pH in oral healthy patients with morning breath through an analog and a digital pHmeter and color pH indicators, before and immediately after use of different mouthwashes and 30 minutes after rinsing; verify different mouthwashes pH; evaluate if there is difference in pH measurements between analog and digital pHmeters; evaluate the patients opinions about the mouthwashes and relate the possible pH alterations to parameters of halitosis. 50 patients were allocated in 5 groups, with 5 different solutions rinses - Cetilpiridine chloride associated with sodium chloride (Saúde Bucal®), Triclosan (Colgate Total Plax®), enzymatic solution (Biotène Mouthwash®), essential oil (Listerine®) and distilled water (control). The patients had been submitted to two exams; the second one occurred in the morning period, without food and drink. In the first exam, the patients were submitted to clinical examination; in the second one, saliva collection, pH analysis and questionnaire application were performed. The data was analyzed by means of the ANOVA two criteria test, paired t-test and Tukey test (p<0,05), which showed that Colgate Total Plax® and Listerine® had increased saliva pH immediately after rinsing and Biotène Mouthwash® reduced saliva and tongue coat pH. We also observed that the four commercial marks of mouthwashes tested had presented acid pH and that analog pHmeter has offered bigger average values that digital pHmeter. The mouthwashes with best acceptance for the studied population had been Saúde Bucal® and Biotène Mouthwash®.
20

Efeito da cinza de biomassa florestal na fertilidade e na sorção de imazetapir em solos ácidos / Effect of wood ash on soil fertility and on sorption behaviour of imazethapyr in acid soils

Nascimento, Bruna Botin 14 November 2013 (has links)
As indústrias de papel e celulose geram enormes quantidades de cinzas de caldeira todos os anos. A disposição final dessas cinzas em aterros costumava ser prática comum, porém a sua utilização em solos florestais e agrícolas merece consideração devido ao seu potencial de corrigir a acidez e de fertilizar os solos, minimizando assim a pressão sobre sua forma de descarte no ambiente. No entanto, o uso desse resíduo pode afetar diretamente a dinâmica de pesticidas no solo, além de adicionar metais pesados. Desta forma, o presente trabalho avaliou o efeito de três cinzas de biomassa florestal (C-1, C-11 e C-27) na fertilidade e na sorção do herbicida imazetapir em três solos com atributos físico-químicos distintos (RQd, LVd e LVAd). Além das três cinzas, calcário e o controle compuseram os tratamentos, os quais foram incubados por três meses. Posteriormente, estudos de sorção do herbicida imazetapir foram realizados nos diferentes tratamentos. As cinzas C-11 e C-27 aumentarem o valor do pH dos solos e os teores de macroelementos, mas reduziram os teores de microelementos catiônicos. A C-1 mostrou ser boa fonte de K para os solos. Nenhuma cinza mostrou-se limitante quanto ao teor de metais pesados. De forma geral, o imazetapir apresentou baixo potencial de sorção nos solos e seus respectivos tratamentos (Kd < 1,8 L kg-1). A C-11 e a C-27 reduziram enquanto que a C-1 aumentou o potencial de sorção do imazetapir nos solos, o que foi devido às alterações nos valores de pH do solo. A sorção foi ligeiramente maior no solo com maiores teores de argila e carbono orgânico (LVd), enquanto a dessorção foi maior no solo de teores intermediários (LVAd). Houve histerese em todos os solos, sugerindo irreversibilidade de parte do herbicida sorvido. / The pulp and paper industries generate huge amounts of wood ash every year. The ashes disposals in landfills used to be a common practice, but their use in agricultural and forest soils deserves special attention due to their potential to neutralize acidity and to fertilize soils, thus decreasing pressure about their environmental disposal. However, the use of this residue may directly impact the dynamic of pesticides as well as add heavy metals to the soils. Therefore, this study evaluated the effects of three wood ashes (C-1 , C-11, and C-27 ) in the fertility and sorption of imazethapyr in three soils (RQd, LVd, LVAd), with contrasting physical-chemical attributes. Besides the ashes, lime and control treatments were added, all of them incubated for three months. Afterwards, batch sorption isotherms for imazethapyr were performed for all treatments. The C-11 and C-27 enhanced soil-pH and macroelement contents, but decreased cationic microelement contents. The C-1 was a good source of K to the soils. There is little risk of contamination by heavy metals. Overall, imazethapyr sorption was low in all soils and their respective treatments (Kd < 1,8 L kg-1). The C-11 and the C-27 decreased whereas C-1 enhanced sorption of imazethapyr to the soils, most likely due to changes in soil-pH. Sorption was slightly higher in the soil with higher clay and organic carbon contents (LVd) whereas desorption was higher in the soil with intermediate values (LVAd). There was hysteresis, suggesting irreversibility during sorption/desorption processes.

Page generated in 0.0193 seconds