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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

On the Expressivity of Infinite and Local Behaviour in Fragments of the pi-calculus

Aranda, Jesus 27 November 2009 (has links) (PDF)
The pi-calculus [61] is one the most influential formalisms for modelling and analyzing the behaviour of concurrent systems. This calculus provides a language in which the structure of terms represents the structure of processes together with an operational semantics to represent computational steps. For example, the parallel composition term P | Q, which is built from the terms P and Q, represents the process that results from the parallel execution of the processes P and Q. Similarly, the restriction (v x)P represents a process P with local resource x. The replication !P can be thought of as abbreviating the parallel composition P | P | . . . of an unbounded number of P processes. As for other language-based formalisms (e.g., logic, formal grammars and the pi-calculus) a fundamental part of the research in process calculi involves the study of the expressiveness of fragments or variants of a given process calculus. In this dissertation we shall study the expressiveness of some variants of the pi-calculus focusing on the role of the terms used to represent local and infinite behaviour, namely restriction and replication. The first part of this dissertation is devoted to the expressiveness of the zero-adic variant of the (polyadic) pi-calculus, i.e., CCS with replication (CCS!) [21]. Busi et al [22] show that CCS! is Turing powerful [22]. The result is obtained by encoding Random Access Machines (RAMs) in CCS!. The encoding is said to be non-faithful because it may move from a state which can lead to termination into a divergent one which do not correspond to any configuration of the encoded RAM. I.e., the encoding is not termination preserving. In this dissertation we shall study the existence of faithful encodings into CCS! of models of computability strictly less expressive than Turing Machines. Namely, grammars of Types 1 (Context Sensitive Languages), 2 (Context Free Languages) and 3 (Regular Languages) in the Chomsky Hierarchy. We provide faithful encodings of Type 3 grammars. We show that it is impossible to provide a faithful encoding of Type 2 grammars and that termination-preserving CCS! processes can generate languages which are not Type 2. We finally conjecture that the languages generated by termination-preserving CCS! processes are Type 1 . We also observe that the encoding of RAMs [22] and several encoding of Turing-powerful formalisms in pi-calculus variants may generate an unbounded number of restrictions during the simulation of a given machine. This unboundedness arises from having restrictions under the scope of replication (or recursion) as in e.g., !(v x)P or μX.(v x)(P | X). This suggests that such an interplay between these operators is fundamental for Turing completeness. We shall also study the expressive power of restriction and its interplay with replication. We do this by considering several syntactic variants of CCS! which differ from each other in the use of restriction with respect to replication. We consider three syntactic variations of CCS! which do not allow the generation of unbounded number of restrictions: C2 is the fragment of CCS! not allowing restrictions under the scope of a replication, C3 is the restriction-free fragment of CCS!. The third variant is C4 which extends C2 with Phillips' priority guards [76]. We shall show that the use of an unboundedly many restrictions in CCS! is necessary for obtaining Turing expressiveness in the sense of Busi et al [22]. We do this by showing that there is no encoding of RAMs into C2 which preserves and reflects convergence. We also prove that up to failures equivalence, there is no encoding from CCS! into C2 nor from C2 into C3. Thus up to failures equivalence, we cannot encode a process with an unbounded number of restrictions into one with a bounded number of restrictions, nor one with a bounded number of restrictions into a restriction-free process. As lemmata for the above results we prove that convergence is decidable for C2 and that language equivalence is decidable for C3 but undecidable for C2. As corollary it follows that convergence is decidable for restriction-free CCS. Finally, we show the expressive power of priorities by providing a faithful encoding of RAMs in C4 thus bearing witness to the expressive power of Phillips' priority guards [76]. The second part of this dissertation is devoted to expressiveness of the asynchronous monadic pi-calculus, A [15, 47]. In [70] the authors studied the expressivenessn of persistence in Api [15, 47] wrt weak barbed congruence. The study is incomplete because it ignores divergence. We shall present an expressiveness study of persistence in Api wrt De Nicola and Hennessy's testing scenario which is sensitive to divergence. Following [70],,we consider Api and three sub-languages of it, each capturing one source of persistence: the persistent-input Api-calculus (PIA), the persistent-output Api-calculus (POA) and the persistent Api-calculus (PA). In [70] the authors showed encodings from Api into the semi-persistent calculi (i.e., POA and PIA) correct wrt weak barbed congruence. We show that, under some general conditions related to compositionality of the encoding and preservation of the infinite behaviour, there cannot be an encoding from Api into a (semi)-persistent calculus preserving the must testing semantics. We also prove that convergence and divergence are decidable for POA (and PA). As a consequence there is no encoding preserving and reflecting divergence or convergence from Api into POA (and PA). This study fills a gap on the expressiveness study of persistence in A in [70].
22

A study of the growth and aggregation of calcium oxalate monohydrate / by Allan Sidney Bramley.

Bramley, Allan Sidney January 1994 (has links)
Bibliography: leaves 278-289. / xi, 324 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on experimental investigation of the growth and aggregation of calcium oxalate mono-dydrate in metastable saline solutions using batch and continuous systems. The physical chemistry of calcium oxalate mono-hydrate in aqueous solutions is considered. A tubular crystalliser to be used as an in vitro system is described. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1996?
23

Urolitíase em bovinos da raça Guzerá (Bos taurus indicus): estudo comparativo em animais oriundo de propriedades com e sem o problema

Sacco, Soraya Regina [UNESP] 15 December 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-15Bitstream added on 2014-06-13T20:30:46Z : No. of bitstreams: 1 sacco_sr_me_botfmvz.pdf: 521815 bytes, checksum: ea56d7609efe9156d8c8d322f678151f (MD5) / Universidade Estadual Paulista (UNESP) / Diversos fatores podem contribuir para a formação de cálculos urinários, dentre estes, o desequilíbrio nutricional e a dureza da água consumida pelos ruminantes. O objetivo deste estudo foi identificar as características de propriedades que predispõem à urolitíase, através da avaliação da água, da dieta e determinações séricas e urinárias de cálcio, fósforo, magnésio, cloretos, sódio, potássio, cálculo da excreção fracionada (EF) dos eletrólitos, e da uréia, creatinina, proteína total, albumina e globulinas séricas. Foram colhidas amostras de sangue e urina de bovinos, Guzerá, criados semi intensivamente, distribuídos por dois grupos. O primeiro denominado grupo urolitíase (Gu), composto de animais com histórico, sinais clínicos e confirmação ultrassonográfica que apresentavam urolitíase; o segundo: grupo controle (Gc), sem histórico, nem sintomas da doença. Os bovinos do grupo urolitíase consumiam água com dureza total na concentração de 166,0 mg CaCO3/L. A dieta dos animais do Gu apresentava maior concentração de fósforo e relação Ca:P inadequada. Os teores de fósforo sérico e urinário dos animais do Gu foram maiores do que os do Gc, assim como a concentração sérica de magnésio (p<0,05). Não houve aumento nas concentrações de uréia e creatinina no grupo urolitíase, mas ocorreu hipoproteinemia por hipoglobulinemia (p<0,05). As EFs de cálcio, fósforo e sódio não diferiram entre os grupos (p>0,05), mas houve diminuição significativa nas EFs de magnésio, cloretos e de potássio do grupo urolitíase (p<0,05). A união destes fatores contribuiu para a ocorrência da urolitíase, sendo dureza total da água e a alta concentração de fósforo na dieta os principais fatores na gênese dos cálculos em bovinos. / Many factors can contribute for the formation of urinary calculi, amongst these, the nutritional imbalances and the hardness of the water consumed for ruminants. The objective of this study was to identify the characteristics of properties that predispose to urolithiasis, through the evaluation of the water, of the diet, and serum and urinary determinations of calcium, phosphorus, magnesium, chlorides, sodium, potassium, calculation of the fractional electrolyte excretion (FE), and urea, creatinine, total protein serum levels, albumin and globulins. Samples of blood and urine of bovines, Guzerá, reared semi intensively, distributed for two groups, the first one, called urolithiasis group (Gu), composed by animals with history, clinical signals and ultrasonography confirmation of urolithiasis; the second one: controlled group (Gc), without history, nor symptoms of the illness. The bovines of the urolithiasis group consumed water with total hardness in the concentration of 166,0 mg CaCO3/L. The diet of the animals of the Gu presented greater phosphorus concentration and inadequate Ca:P relation. The levels of serum and urinary phosphorus of the animals of the Gu were higher of the Gc, as well as the serum magnesium concentration (p<0,05). The urea and creatinine concentrations didn’t have an increase in the urolithiasis group, but occurred hypoproteinemia for hypoglobulinemia in the Gu (p<0,05). The FEs of calcium, phosphorus and sodium had not differed between the groups (p>0,05), but had significant reduction in the FEs of magnesium, chlorides and potassium of the urolithiasis group (p<0,05). The union of these factors contributed for urolithiasis occurrence, being the total hardness of the water and the high phosphorus diet concentration the major factors in genesis of the calculations in bovines.
24

Urolitíase em bovinos da raça Guzerá (Bos taurus indicus) : estudo comparativo em animais oriundo de propriedades com e sem o problema /

Sacco, Soraya Regina. January 2009 (has links)
Orientador: Raimundo Souza Lopes / Banca: Carlos Alberto Hussni / Banca: Fernando José Benesi / Resumo: Diversos fatores podem contribuir para a formação de cálculos urinários, dentre estes, o desequilíbrio nutricional e a dureza da água consumida pelos ruminantes. O objetivo deste estudo foi identificar as características de propriedades que predispõem à urolitíase, através da avaliação da água, da dieta e determinações séricas e urinárias de cálcio, fósforo, magnésio, cloretos, sódio, potássio, cálculo da excreção fracionada (EF) dos eletrólitos, e da uréia, creatinina, proteína total, albumina e globulinas séricas. Foram colhidas amostras de sangue e urina de bovinos, Guzerá, criados semi intensivamente, distribuídos por dois grupos. O primeiro denominado grupo urolitíase (Gu), composto de animais com histórico, sinais clínicos e confirmação ultrassonográfica que apresentavam urolitíase; o segundo: grupo controle (Gc), sem histórico, nem sintomas da doença. Os bovinos do grupo urolitíase consumiam água com dureza total na concentração de 166,0 mg CaCO3/L. A dieta dos animais do Gu apresentava maior concentração de fósforo e relação Ca:P inadequada. Os teores de fósforo sérico e urinário dos animais do Gu foram maiores do que os do Gc, assim como a concentração sérica de magnésio (p<0,05). Não houve aumento nas concentrações de uréia e creatinina no grupo urolitíase, mas ocorreu hipoproteinemia por hipoglobulinemia (p<0,05). As EFs de cálcio, fósforo e sódio não diferiram entre os grupos (p>0,05), mas houve diminuição significativa nas EFs de magnésio, cloretos e de potássio do grupo urolitíase (p<0,05). A união destes fatores contribuiu para a ocorrência da urolitíase, sendo dureza total da água e a alta concentração de fósforo na dieta os principais fatores na gênese dos cálculos em bovinos. / Abstract: Many factors can contribute for the formation of urinary calculi, amongst these, the nutritional imbalances and the hardness of the water consumed for ruminants. The objective of this study was to identify the characteristics of properties that predispose to urolithiasis, through the evaluation of the water, of the diet, and serum and urinary determinations of calcium, phosphorus, magnesium, chlorides, sodium, potassium, calculation of the fractional electrolyte excretion (FE), and urea, creatinine, total protein serum levels, albumin and globulins. Samples of blood and urine of bovines, Guzerá, reared semi intensively, distributed for two groups, the first one, called urolithiasis group (Gu), composed by animals with history, clinical signals and ultrasonography confirmation of urolithiasis; the second one: controlled group (Gc), without history, nor symptoms of the illness. The bovines of the urolithiasis group consumed water with total hardness in the concentration of 166,0 mg CaCO3/L. The diet of the animals of the Gu presented greater phosphorus concentration and inadequate Ca:P relation. The levels of serum and urinary phosphorus of the animals of the Gu were higher of the Gc, as well as the serum magnesium concentration (p<0,05). The urea and creatinine concentrations didn't have an increase in the urolithiasis group, but occurred hypoproteinemia for hypoglobulinemia in the Gu (p<0,05). The FEs of calcium, phosphorus and sodium had not differed between the groups (p>0,05), but had significant reduction in the FEs of magnesium, chlorides and potassium of the urolithiasis group (p<0,05). The union of these factors contributed for urolithiasis occurrence, being the total hardness of the water and the high phosphorus diet concentration the major factors in genesis of the calculations in bovines. / Mestre
25

The disintegration and dissolution of urinary calculi

Levi, David Winterton 23 February 2010 (has links)
A brief investigation was made of various enzymes such as urease in conjunction with a wetting agent, ficin, steapsin, and hyaluronidase as aides in the :in vitro" dissolution of calculi in "G"⁷ solution. This investigation indicated that a more effective solvent was needed. / Master of Science
26

The dissolution of urinary calculi

Claffey, Lawrence Webster January 1943 (has links)
A brief investigation was made of various organic and inorganic solvents for the dissolution of urinary calculi in vitro and Albright’s (1) citric acid buffer and a solvent designated in this investigation simply as “G” (33) were shown to be the most efficient solvents. Further investigation showed that something was necessary to increase the efficiency of these solvents, as the dissolution would proceed to a certain point where the solvent ceased to act. It was at this point that the investigation changed its course and the attack was centered on the organic colloidal matrix in the structure of the stone. It is a well known fact that this organic matrix is resistant to weak acids and bases (30) and therefore the course of the investigation pointed to those most remarkable agents, “the enzymes”, which due to their enormous amount of surface energy are capable of producing astonishing results. The enzymes investigated were not selected for their specific action, but they were selected for the purpose of studying the effect of their surface energy on the colloidal matrix of urinary calculi. The investigation indicates that a calculus pretreated with urease for fifteen minutes, followed by a 6 hour irrigation with “G” (33) solution is sufficient to cause dissolution and disintegration in nearly all of the one hundred calculi selected at random. (See Table 5) The ability of urease to hasten disintegration may be due to its activity on the colloidal matrix, causing it to swell, thereby giving back the former hydrotropic properties mentioned by Snapper (52). Colloidal material was isolated from a large calculus and was subjected to the action of urease. After 6 hours the colloids from the calculus had swollen approximately five hundred times their original volume, and changed from a dark brown-colored material to a white translucent gel. These organic colloidal matrices of urinary calculi are apparently of a reversible nature and irreversible as investigators have assumed in the past (30). Investigations were made and reported in various sections of this paper on the ability of other enzymes, peroxide, and acids to act as dissolution agents or as aids to dissolution. An efficient in vitro irrigator Fig. 1 is described and its merit in the irrigation of urinary calculi lies in the facts that its construction is simple, its rate of flow can be accurately regulated by a slight manipulation, and the calculus can be treated in various ways without removing it from the original crucible. It now remains for the urologist to investigate the possibility of in vitro dissolution, using the above auxiliary agent. It is suggested that the urease might be used simultaneously with the irrigation solvent. / Ph. D.
27

The effect of shock wave delivery rate on stone clearance, pain tolerance and renal injury in extracorporeal shock wave lithotripsy. / 沖擊波輸出頻率在體外沖擊波碎石治療的治療成效、病人對治療忍耐程度和對腎臟創傷的影響 / Chong ji bo shu chu pin lu zai ti wai chong ji bo sui shi zhi liao de zhi liao cheng xiao, bing ren dui zhi liao ren nai cheng du he dui shen zang chuang shang de ying xiang

January 2011 (has links)
by Lo, Kin Yin Anthony. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 168-195). / Abstracts in English and Chinese. / Abstract --- p.i / Declaration --- p.V / Publications and Conference Presentations --- p.vi / Scholarships and Awards --- p.vii / Acknowledgements --- p.viii / Table of contents --- p.X / Abbreviations --- p.xiv / List of Figures --- p.xvi / List of Tables --- p.xvii / Chapter 1. --- General Introduction --- p.1 / Chapter 2. --- Literature Review --- p.7 / Chapter 2.1 --- Introduction of nephrolithasis and surgical management --- p.9 / Chapter 2.1.1 --- Epidemology and physiochemistry --- p.9 / Chapter 2.1.2 --- Surgical management of nephrolithasis parallel with stone factors --- p.15 / Chapter 2.2 --- Extracorpoeral Shock Wave Lithotripsy in present study --- p.17 / Chapter 2.2.1 --- The 4th generation - Sonolith Vision electroconductive lithotripter --- p.18 / Chapter 2.2.2 --- The role of shock wave delivery rate in treatment outcome and its prediction --- p.23 / Chapter 2.2.3 --- Patient-controlled analgesia during Shock Wave Lithotripsy treatment and its pain management --- p.29 / Chapter 2.2.4 --- Shock wave induced renal injury & the use of urinary biomarker --- p.35 / Chapter 3. --- Materials and Methods --- p.62 / Chapter 3.1 --- Study Design --- p.63 / Chapter 3.2 --- Patient Selection --- p.64 / Chapter 3.3 --- Treatment Protocol --- p.63 / Chapter 3.4 --- Sample size calculation --- p.68 / Chapter 3.5 --- Statistical analysis --- p.68 / Chapter 4. --- The effect of shock wave delivery rate on treatment outcome and its prediction --- p.69 / Chapter 4.1 --- Introduction --- p.70 / Chapter 4.2 --- Materials and Methods --- p.72 / Chapter 4.2.1 --- ESWL treatment protocol --- p.72 / Chapter 4.2.2 --- Outcome Assessment --- p.73 / Chapter 4.2.3 --- Mathematical model development --- p.75 / Chapter 4.2.4 --- Statistical analysis --- p.76 / Chapter 4.3 --- Results --- p.77 / Chapter 4.3.1 --- Baseline characteristics and treatment modalities --- p.78 / Chapter 4.3.2 --- ESWL treatment outcome --- p.79 / Chapter 4.3.3 --- Mathematical model --- p.81 / Chapter 4.4 --- Discussion --- p.82 / Chapter 4.4.1 --- Overall treatment outcome improved by the use of slower rate --- p.82 / Chapter 4.4.2 --- When should we use fast/slow rate? --- p.86 / Chapter 4.4.3 --- Mathematical model to predict ESWL outcome --- p.88 / Chapter 4.5 --- Conclusion --- p.91 / Chapter 5. --- The role of shock wave delivery rate and patient-controlled analgesia in pain --- p.101 / Chapter 5.1 --- Introduction --- p.102 / Chapter 5.2 --- Materials and Methods --- p.104 / Chapter 5.2.1 --- ESWL treatment protocol and PCA settings --- p.104 / Chapter 5.2.2 --- Outcome Assessment --- p.105 / Chapter 5.2.3 --- Statistical analysis --- p.107 / Chapter 5.3 --- Results --- p.108 / Chapter 5.3.1 --- Baseline characteristics and treatment modalities --- p.108 / Chapter 5.3.2 --- Pain experience and satisfaction with PCA at different shock wave delivery rates --- p.108 / Chapter 5.3.3 --- Correlation between rate pain --- p.110 / Chapter 5.3.4 --- Vital signs --- p.110 / Chapter 5.4 --- Discussion --- p.111 / Chapter 5.4.1 --- Adverse complication was mild with PCA using alfentanil --- p.111 / Chapter 5.4.2 --- Less pain experience with 60 SWs/min --- p.112 / Chapter 5.4.3 --- Why PCA usage was the same in both groups? --- p.112 / Chapter 5.4.4 --- No correlation with treatment outcome --- p.114 / Chapter 5.5 --- Conclusion --- p.115 / Chapter 6. --- "The relations among rate of shock wave delivery, induced renal injury and acute complications" --- p.128 / Chapter 6.1 --- Introduction --- p.129 / Chapter 6.2 --- Materials and Methods --- p.130 / Chapter 6.2.1 --- ESWL treatment protocol --- p.130 / Chapter 6.2.2 --- Outcome Assessment --- p.131 / Chapter 6.2.3 --- Statistical analysis --- p.136 / Chapter 6.3 --- Results --- p.137 / Chapter 6.3.1 --- Baseline characteristics and treatment modalities --- p.137 / Chapter 6.3.2 --- Quality control of creatinine and NAG --- p.137 / Chapter 6.3.3 --- Standard curves ofIL-18 and NGAL --- p.137 / Chapter 6.3.4 --- Higher levels of urinary NAG and IL-18 in 60 SWs/min group --- p.138 / Chapter 6.3.5 --- Similar levels of urinary NGAL in both groups --- p.138 / Chapter 6.3.6 --- Unplanned hospital visits were similar in both groups --- p.139 / Chapter 6.4 --- Discussion --- p.140 / Chapter 6.4.1 --- More tubular damages caused by slower rate --- p.140 / Chapter 6.4.2 --- Escalated inflammatory activities in 60 SWs/min --- p.141 / Chapter 6.4.3 --- Vascular damage and ischemic insults were the same in both groups? --- p.142 / Chapter 6.4.4 --- Post-operative complications are similar in both groups --- p.142 / Chapter 6.4.5 --- 60 SWs/min vs. 120 SWs/min - What makes the difference in renal injury? --- p.143 / Chapter 6.5 --- Conclusion --- p.145 / Chapter 7. --- Discussion --- p.154 / Chapter 7.1 --- General discussion --- p.155 / Chapter 8. --- Conclusion --- p.158 / Chapter 8.1 --- General conclusion --- p.159 / Appendix --- p.160 / Appendix I --- p.161 / Appendix II --- p.163 / References --- p.167
28

Composição de urólitos vesicais de cães determinada por espectroscopia de energia dispersiva (EDS) e análise química / Dog bladder uroliths composition determined by energy dispersive spectroscopy (EDS) and chemical analysis

Ariza , Paula Costa 04 November 2014 (has links)
Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2015-10-15T20:57:59Z No. of bitstreams: 2 Dissertação - Paula Costa Ariza - 2014.pdf: 2597495 bytes, checksum: e1ee58eb0f7e1510104c7b8960099df6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-16T11:12:05Z (GMT) No. of bitstreams: 2 Dissertação - Paula Costa Ariza - 2014.pdf: 2597495 bytes, checksum: e1ee58eb0f7e1510104c7b8960099df6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-16T11:12:05Z (GMT). No. of bitstreams: 2 Dissertação - Paula Costa Ariza - 2014.pdf: 2597495 bytes, checksum: e1ee58eb0f7e1510104c7b8960099df6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-11-04 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Urolithiasis is frequently and recurrently observerd on dogs.. Uroliths are crystalline concretions that form in the lumen of the urinary tract due to urine oversaturation by minerals. They may lead to serious consequences, such as obstruction of the urinary flow. An efficient treatment depends on the compositional analysis of the uroliths This study aimed to evaluate the composition of dog’s urinary calculi in the city of Goiânia, by using chemical analysis and energy dispersive spectroscopy – EDS. Comparisons between the composition found and individual and clinical characteristics of the patients were made, as well as comparisons between both techniques. Analysis were held on 55 surgical removed uroliths fom the bladder of dogs. Struvite was present in 51 of the uroliths (15 isolatedly), calcium phosphate in 32 (always associated to struvite), calcium oxalate in five (two isolatedly), urate in five (two isolatedly) and silica was present in four (none of the uroliths was composed only by silica). The most common combination of compounds was that of struvite and calcium phosphate. EDS permitted both the evaluation of the different regions of the uroliths and the microscopical observation of the sample structure, but didn’t allow the correct identification of the urate. The association between both techniques was efficient on evaluating the calculi composition. / A urolitíase acomete frequentemente e de maneira recorrente os cães. Os urólitos são concreções cristalinas que se formam no lúmen do trato urinário devido à supersaturação da urina por minerais. Podem levar a graves consequências, como a obstrução do fluxo urinário. O tratamento eficaz depende da análise adequada da composição dos urólitos presentes. Com o presente estudo objetivou-se avaliar a composição de cálculos urinários de cães atendidos no Município de Goiânia, fazendo uso de análise química por meio o uso de reagentes comerciais e da espectroscopia de energia dispersiva – EDS, de modo a estabelecer a relação entre a composição dos urólitos e características individuais e clínicas dos animais, bem como a comparação entre ambas as técnicas. Foram analisados 55 urólitos cirurgicamente removidos da vesícula urinária de cães. Dos cálculos analisados, 51 apresentaram estruvita (15 de maneira isolada), 32 fosfato de cálcio (todos associados à estruvita), cinco oxalato de cálcio (dois apenas com esse mineral), cinco urato (dois apenas com esse mineral) e quatro sílica (nenhum apresentava sílica isoladamente em sua composição). A combinação mais comum foi a de estruvita com fosfato de cálcio. O EDS permitiu a avaliação da composição das diferentes regiões dos cálculos de maneira independente, bem como a análise microscópica da estrutura do mesmo, mas não possibilitou a identificação específica do urato. Desse modo a sua associação à técnica química a torna uma técnica eficiente para a análise dos urólitos.
29

Estudo retrospectivo e prospectivo da urolitíase em cães / Retrospective and prospective study of urolithiasis in dogs

Oyafuso, Mônica Kanashiro 16 July 2008 (has links)
A urolitíase ocorre com relativa freqüência dentre as afecções que acometem o trato urinário inferior de cães e gatos. Urólitos são agregados de material cristalino e matriz que se forma em um ou mais locais no trato urinário quando a urina torna-se supersaturada com substâncias cristalogênicas. A constituição dos urólitos pode ser decorrente de deposição de um único tipo mineral ou de minerais diferentes que se depositam em camadas (laminações) ou simplesmente agregam-se à pedra. Dependendo do tipo mineral e sua distribuição no urólito, este pode ser classificado em simples (apenas uma camada com predomínio - >70% - de um único tipo mineral), misto (também apenas uma camada identificável, porém sem predomínio de um único mineral) ou composto (presença de mais de uma camada de composição mineral diferente). Atualmente existem dois métodos de análise da composição mineral de cálculo: análise qualitativa e quantitativa, porém apenas a quantitativa permite a determinação do percentual das diferentes composições minerais, além de ser um método mais sensível e específico. Este estudo teve como objetivo analisar os casos de urolitíase canina que tiveram seus cálculos analisados quantitativamente, atendidos no Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (FMVZ-USP). Foram analisados 161 urólitos provenientes de 156 cães (5 animais apresentaram recidiva), durante o período de fevereiro de 1999 a janeiro de 2007. Todas as análises foram realizadas no Minnesota Urolith Center, baseada nos métodos de microscopia de luz polarizada, espectroscopia infravermelha e espectroscopia por raios-X com dispersão de energia. Apenas 30,2% (106) dos urólitos eram simples, 1,9% (3) mistos e 67,9% (47) eram compostos. Apesar desse predomínio de urólitos compostos, a avaliação individual desses revelou que 64 de 106 urólitos compostos continham em todas as suas camadas, predomínio (>70%) de um mesmo tipo mineral: 26 continham estruvita, 35 oxalato de cálcio (mono ou dihidratado) e três de urato (urato ácido de sódio e urato ácido de amônio). Tais urólitos, apesar de classificados como compostos poderiam ser manejados como urólitos simples. Por outro lado, 30 urólitos compostos tinham a região interna minerais passíveis de dissolução, mas que seria impedida por uma camada mineral externa não passível de dissolução. O inverso ocorreu em 3 amostras (apenas a camada mais externa seria passível de dissolução) e outras duas amostras apresentaram deposição sequencial de minerais passíveis de dissolução, porém, que exigiriam protocolos distintos. Assim, o conhecimento da composição de todas as camadas (núcleo, pedra, parede e superfície) que compõe o urólito é essencial para o entendimento da formação do cálculo e conseqüentemente para a indicação do tratamento adequado, assim como para a prevenção de recidivas. / Urolithiasis is a relatively common urinary tract disorder of dogs and cats. Whenever urine becomes oversaturate with cristallogenic substances, uroliths may be formed from crystalline material and protein matrix. Uroliths may be composed from only one kind or from different types of minerals, which can be deposited in layers or aggregate forming a stone. They can be classified according to their mineral type and distribution in: simple (only one layer and more than 70% of a single mineral), mixed (one identifiable layer, without predominance of a mineral type) or coumpound (more than one layer of different mineral types). Currently, there are two methods of urolith analyses: quantitative and qualitative analysis. However, only quantitative analysis allows determination of the mineral composition with accuracy, and it is a more sensitive and specific test. One hundred and sixty one canine uroliths were obtained from the Hospital of the School of Veterinary Medicine and Zootechny of University of São Paulo (FMVZ-USP) and were submitted to Minnesota Uroliths Center for quantitative analysis from February 1999 to January 2007. All uroliths were analyzed using polarizing light microscopy, infrared spectroscopy and energy dispersive X-ray spectroscopy. One hundred and six (30,2%) were simple uroliths, 3 (1,9%) mixed, and 47 (67,9%) were compound. Despite the predominance of compound uroliths, individual urolithevaluation revealed that 64 of 106 compound uroliths had a predominant mineral type (>70%) in all layers: 26 were struvite, 35 calcium oxalate (mono or dihydrate) and 3 were urate (sodium acid urate and ammonium acid urate). These uroliths, despite being classified as compound uroliths, could be assumed as simple uroliths. However, 30 compound uroliths had dissoluble inner layers, but the outer layer would prevent them from being dissovable. Three samples had the opposite (outer layer could be dissoluted, but inner layer could not) and 2 other samples had required two different protocols for medical dissolution. Knowledge the composition of all layers (nidus, stone, shell and surface crystals) is essential to understand the urolith etiology and a key factor to successful therapy and prevent recurrence.
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Avaliação metabólica de homens idosos portadores de litíase urinária / Metabolic assessment of aging men with urolithiasis

Freitas Júnior, Celso Heitor de 09 December 2011 (has links)
OBJETIVOS: O aumento da expectativa de vida tem gerado um envelhecimento populacional global, fazendo com que a proporção de indivíduos com mais de 60 anos de idade cresça mais rapidamente do que as demais faixas etárias. A incidência de litíase urinária em indivíduos idosos tem aumentado nos últimos anos, principalmente em nações industrializadas. Aspectos particulares do envelhecimento orgânico aumentam a morbidade associada à litíase urinária em idosos, tornando a prevenção e o tratamento clínico ainda mais relevantes nessa faixa etária. Nosso objetivo é analisar a avaliação metabólica de homens idosos portadores de cálculos renais. MATERIAIS E MÉTODOS: Realizamos um estudo clínico tipo caso-controle. Os critérios de inclusão foram: indivíduos do sexo masculino com mais de 60 anos de idade, com antecedente de cólica renal ou diagnóstico incidental de litíase urinária após os 60 anos (grupo caso); no grupo controle foram incluídos pacientes da mesma faixa etária sem antecedente de cólica renal ou diagnóstico incidental de litíase renal. Todos os participantes foram submetidos à anamnese e aqueles selecionados realizaram perfil metabólico para diagnóstico de litíase urinária: dosagem sérica de cálcio total, cálcio ionizado, ácido úrico, fósforo, glicemia, uréia, creatinina e paratormônio (PTH); coleta de urina para urocultura e pH urinário, e amostras de urina de 24 horas para quantificação do volume e dosagem de cálcio, citrato, creatinina, ácido úrico e sódio. Foram também submetidos à radiografia simples de abdome e ultrassonografia do aparelho urinário. Os indivíduos do grupo caso realizaram dois perfis metabólicos completos de urina de 24 horas, enquanto os do grupo controle somente um perfil. Os resultados foram submetidos à análise estatística. RESULTADOS: Cento e dez indivíduos foram convocados e, após aplicação dos critérios de inclusão, 70 foram selecionados. Cinquenta e um indivíduos concluíram a investigação clínica, sendo 25 no grupo caso e 26 no controle. Cinquenta e seis por cento dos pacientes do grupo caso apresentaram hipocitratúria comparados a 15,4% do grupo controle (p=0,002). A determinação de sódio em urina de 24 horas também apresentou diferença estatisticamente significativa entre casos e controles: 64% versus 30,8%, respectivamente (p=0,017). Estes resultados foram submetidos à análise de regressão logística univariada e múltipla, respectivamente, e mantiveram seus níveis de significância. CONCLUSÃO: A hipocitratúria e a hipernatriúria são os principais distúrbios metabólicos apresentados por indivíduos idosos do sexo masculino portadores de cálculo urinário / PURPOSES: Rise in life expectancy has caused a global populational ageing and people older than 60-years have increased more than any other age group. The incidence of urinary lithiasis in aging people has increased during the last years, mainly in developed nations. Some aspects concerning organic ageing increase morbidity related to urolithiasis in older individuals making prevention and medical management of urinary stones relevant in this age group. Our objective is to evaluate metabolic parameters in men older than 60 years with urinary stones. MATERIALS AND METHODS: A case-control study was performed. Inclusion criteria were: men older than 60- years old with renal pain episodes or incidental diagnosis of urinary lithiasis beginning after 60-years old (case arm). Control group was constituted by patients older than 60 years without renal colic past or diagnosis of urolithiasis. Patients were recruited from a database from the Urologic Clinic at University of São Paulo Medical School Hospital. Each individual was submitted to anamnesis and those selected underwent a metabolic evaluation for urinary stones: serum dosages of total and ionized calcium, uric acid, phosphorus, glucose, urea, creatinine and parathyroid hormone (PTH); urine culture and urinary pH. Twenty four hour urine samples were obtained for volume quantification and for calcium, citrate, creatinine, uric acid and sodium dosages. An abdominal x-ray and ultrasonography were performed in all patients. Case arm patients underwent two complete metabolic urinary investigations while control arm individuals to only one. All results were submitted to statistical analysis. RESULTS: One hundred and ten individuals were called up for initial evaluation and 70 were selected. Fifty-one individuals concluded the whole clinical investigation: 25 in the case arm and 26 in the control arm. Hypocitraturia was present in 56% of case arm patients and 15,4% of the control arm patients (p=0,002). Hypernatriuria in 24-hour urine samples was found in 64% of case arm patients and in 30,8% of control arm patients (p=0,017). These results were submitted to univariate and multiple logistic regressions and maintained their levels of significancy. CONCLUSION: Hypocitraturia and hypernatriuria are the main metabolic disorders among aging men with urolithiasis

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