Showing papers by "State University of Campinas published in 2004"

Validação em métodos cromatográficos e eletroforéticos

Abstract: The validation of an analytical method is fundamental to implementing a quality control system in any analytical laboratory. As the separation techniques, GC, HPLC and CE, are often the principal tools used in such determinations, procedure validation is a necessity. The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing, in a general way, the similarities and differences between the guidelines established by the different Brazilian and international regulatory agencies.

Properties and performance of the prototype instrument for the Pierre Auger Observatory

Abstract: Construction of the first stage of the Pierre Auger Observatory has begun. The aim of the Observatory is to collect unprecedented information about cosmic rays above 1018 eV. The first phase of the project, the construction and operation of a prototype system, known as the engineering array, has now been completed. It has allowed all of the sub-systems that will be used in the full instrument to be tested under field conditions. In this paper, the properties and performance of these sub-systems are described and their success illustrated with descriptions of some of the events recorded thus far. © 2003 Elsevier B.V. All rights reserved.

The image foresting transform: theory, algorithms, and applications

Abstract: The image foresting transform (IFT) is a graph-based approach to the design of image processing operators based on connectivity. It naturally leads to correct and efficient implementations and to a better understanding of how different operators relate to each other. We give here a precise definition of the IFT, and a procedure to compute it-a generalization of Dijkstra's algorithm-with a proof of correctness. We also discuss implementation issues and illustrate the use of the IFT in a few applications.

Validation for chromatographic and electrophoretic methods

Abstract: The validation of an analytical method is fundamental to implementing a quality control system in any analytical laboratory. As the separation techniques, GC, HPLC and CE, are often the principal tools used in such determinations, procedure validation is a necessity. The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing, in a general way, the similarities and differences between the guidelines established by the different Brazilian and international regulatory agencies.

Microbiological examination of infected dental root canals

Abstract: Objectives: The aim of this study was to investigate the root canal microbiota of primary and secondary root-infected canals and the association of constituent species with specific endodontic signs and symptoms. Methods: Microbial samples were taken from 60 root canals, 41 with necrotic pulp tissues (primary infection) and 19 with failed endodontic treatment (secondary infection). Strict anaerobic techniques were used for serial dilution, plating, incubation and identification. Results: A total of 224 cultivable isolates were recovered belonging to 56 different bacterial species. Individual root canals yielded a maximum of 10 bacterial species. Of the bacterial isolates, 70% were either strict anaerobes or microphilic. The anaerobes most frequently isolated were: Peptostreptococcus micros (35%), Fusobacterium necrophorum (23.3%), Fusobacterium nucleatum (11.7%), Prevotella intermedia/nigrescens (16.7%), Porphyromonas gingivalis (6.7%) and Porphyromonas endodontalis (5%). The root canal microflora of untreated teeth with apical periodontitis was found to be mixed, comprising gram-negative and gram-positive and mostly anaerobic microorganisms and usually containing more than 3 species per canal. On the other hand, facultative anaerobic and gram-positive bacteria predominated in canals with failed endodontic treatment, which harbored 1–2 species per canal. Suggested relationships were found between anaerobes, especially gram-negatives, and the presence or history of pain, tenderness to percussion and swelling (P < 0.05). In particular, associations were found between: a) pain (n = 29) and P. micros (P < 0.01), P. intermedia/nigrescens and Eubacterium spp. (both P < 0.05); b) history of pain (n = 31) and P. micros (P < 0.01) Porphyromonas and Fusobacterium spp. (P < 0.05); c) tenderness to percussion (n = 29) and Porphyromonas spp. (P < 0.01), Peptostreptococcus and Fusobacterium spp. (P < 0.001); d) swelling (n = 20) and Peptostreptococcus spp. (P < 0.01), Porphyromonas and Enterococcus spp. (P < 0.05); e) wet canals (n = 33) and Porphyromonas and Fusobacterium spp. (P < 0.05); f) purulent exudate (n = 20) and Porphyromonas, Peptostreptococcus and Fusobacterium spp. (P < 0.05); previous endodontic treatment and Enterococcus faecalis, Streptococcus spp., P. micros, F. necrophorum (P < 0.05). Conclusions: Our findings indicate potential complex interactions of species resulting in characteristic clinical pictures which cannot be achieved by individual species alone. They also indicate that the microbiota of primary infected canals with apical periodontitis differs in number and in species from the secondary infected canals by using the culture technique.

Giant magnetocaloric effect in Gd5(Si2Ge2) alloy with low purity Gd

Abstract: Gd5(Ge1-xSix), x < 4 based alloys are potential candidates for magnetic refrigeration in the range ~20 - ~290 K. However, one of the greatest obstacles for the use of that technology in large scale is the utilization of high pure Gd metal (99.99 wt. (%)) to produce the GdGeSi alloys, since the impurity elements decrease the intensity of the magnetocaloric effect (EMC)1. In this work, we prove that annealing of the Gd5Ge2Si2 can promote remarkable values for the EMC in comparison to those obtained for the alloy with high pure Gd. Also, the as cast alloy and the annealed alloy are not monophasic, but have at least two crystalline phases in their microstructure. Results for X-ray analysis, optical and electronic microscopy and magnetization measurements are reported.

Comparative Genomics of Two Leptospira interrogans Serovars Reveals Novel Insights into Physiology and Pathogenesis

Abstract: Leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in accidental hosts, including humans. Complete genome sequencing of Leptospira interrogans serovar Copenhageni and comparative analysis with the available Leptospira interrogans serovar Lai genome reveal that despite overall genetic similarity there are significant structural differences, including a large chromosomal inversion and extensive variation in the number and distribution of insertion sequence elements. Genome sequence analysis elucidates many of the novel aspects of leptospiral physiology relating to energy metabolism, oxygen tolerance, two-component signal transduction systems, and mechanisms of pathogenesis. A broad array of transcriptional regulation proteins and two new families of afimbrial adhesins which contribute to host tissue colonization in the early steps of infection were identified. Differences in genes involved in the biosynthesis of lipopolysaccharide O side chains between the Copenhageni and Lai serovars were identified, offering an important starting point for the elucidation of the organism's complex polysaccharide surface antigens. Differences in adhesins and in lipopolysaccharide might be associated with the adaptation of serovars Copenhageni and Lai to different animal hosts. Hundreds of genes encoding surface-exposed lipoproteins and transmembrane outer membrane proteins were identified as candidates for development of vaccines for the prevention of leptospirosis.

Characterization of gelatin based films modified with transglutaminase, glyoxal and formaldehyde

Abstract: Protein films possess good gas barrier properties at low to intermediate relative humidity but reduced water vapor barrier properties, which limits their application. The introduction of chemical or enzymatic modifications could be an alternative to improve the cohesion properties of the polymeric matrix due to the formation of cross-linkages, thus improving the barrier characteristics and the mechanical resistance and decreasing the film solubility. The objective of this study was to evaluate and compare the effect of chemical and enzymatic modifications on the solubility, mechanical properties, barrier properties, thermal properties and morphology of gelatin-based films. The results indicated that the treatments resulted in 20% reduction in solubility for all the modified films, whereas the greatest reduction in water vapor permeability was observed for the enzymatic modified films (≅35%) as compared to the native film. The mechanical properties were only significantly affected by treatment with formaldehyde, where an increase of approximately 60% with respect to tensile strength was observed. Greater thermal stability, with an increase in the melting point, was observed for the chemically treated films, indicating a greater degree of cross-linking, as confirmed by the number of free e-amine groups remaining after the modification reactions. The morphological analyses indicated a loss of fibrillar orientation as a function of the introduction of cross-linking and the reduced percentage of renaturation of the modified films, as observed in the calorimetric assays. The results indicated that the effect of cross-linked protein films on water vapor permeability is always limited due to the inherent hydrophobic character of the protein and also on the morphology imposed by the modifications.

In vitro evaluation of the antimicrobial activity of chlorhexidine and sodium hypochlorite

Abstract: The aim of this study was to investigate in vitro the antimicrobial activity of 02%, 1%, and 2% chlorhexidine gluconate (CHX gel and CHX liquid), against endodontic pathogens and compare the results with the ones achieved by 05%, 1%, 25%, 4%, and 525% sodium hypochlorite (NaOCl) A broth dilution test was performed, and the timing for irrigants to kill microbial cells was recorded and statistically analyzed Both 20% gel and liquid formulations eliminated Staphylococcus aureus and Candida albicans in 15 seconds, whereas the gel formulation killed Enterococcus faecalis in 1 minute All tested irrigants eliminated Porphyromonas endodontalis, Porphyromonas gingivalis, and Prevotella intermedia in 15 seconds The timing required for 10% and 20% CHX liquid to eliminate all microorganisms was the same required for 525% NaOCl The antimicrobial action is related to type, concentration, and presentation form of the irrigants as well as the microbial susceptibility

Validation of the "International Consultation on Incontinence Questionnaire - Short Form" (ICIQ-SF) for Portuguese

Abstract: OBJECTIVE: To translate into and validate for Portuguese the "International Consultation on Incontinence Questionnaire - Short Form" (ICIQ-SF), a condition-specific quality-of-life questionnaire for patients with urinary incontinence. METHODS: Two Brazilians independently translated the original ICIQ-SF into Portuguese. These two translations were harmonized, and then checked by independent back-translation by two native English speakers. The harmonized translation was pre-tested in a pilot study on 20 patients. The final version of the ICIQ-SF in Portuguese was applied to 123 consecutive patients aged 16 or over (29 males and 94 females) with a complaint of urinary incontinence, who had sought the Department of Urogynecology and Uroneurology of the School of Medical Sciences of Unicamp. The Portuguese version of the King's Health Questionnaire (KHQ) was also applied to the same group. The psychometric properties of the questionnaire, such as reliability and construct validity were assessed. RESULTS: The median age was 53 years (range: 16 to 86). The mean retest interval for the ICIQ-SF was 14.37 days (range: 6 to 41). No changes from the original format of the ICIQ-SF were observed at the end of the process of translation and cultural adaptation. The internal consistency was high (0.88), as measured by the Cronbach alpha coefficient. The test-retest value was considered moderate to strong, as measured by the weighted Kappa index (range: 0.72 to 0.75) and Pearson correlation coefficient (0.89). The correlation between the ICIQ-SF and KHQ was considered to be moderate to good for most items (range: 0.44 to 0.77). The evaluation of the construct and concurrent validity was also satisfactory and statistically significant. CONCLUSIONS: The "International Consultation on Incontinence Questionnaire" (ICIQ-SF) was successfully translated into Portuguese and validated for application to Brazilian female and male patients complaining of urinary incontinence, with satisfactory reliability and construct validity.

Fracture resistance of roots endodontically treated with a new resin filling material

Abstract: Background The authors evaluated the fracture resistance of endodontically treated teeth filled with either gutta-percha or a new resin-based obturation material. Methods The authors prepared and randomly divided 80 single-canal extracted teeth into five groups: lateral and vertical condensation with gutta-percha, lateral and vertical condensation with the new resin-based obturation material, and a control group with no filling material. The specimens were stored in 100 percent humidity for two weeks, mounted in polyester resin and loaded to failure. Results The authors found statistically significant differences among the experimental groups ( P Conclusions Filling the canals with the new resin-based obturation material increased the in vitro resistance to fracture of endodontically treated single-canal extracted teeth when compared with standard gutta-percha techniques. Clinical Implications If other properties of the new resin-based obturation material compare favorably with those of gutta-percha for filling the root canal, it should be considered as a replacement for gutta-percha, as the results of this study indicate that it could provide enhanced resistance to tooth fracture.

Affine Arithmetic: Concepts and Applications

Abstract: Affine arithmetic is a model for self-validated numerical computation that keeps track of first-order correlations between computed and input quantities. We explain the main concepts in affine arithmetic and how it handles the dependency problem in standard interval arithmetic. We also describe some of its applications.

Método de análise de conteúdo: ferramenta para a análise de dados qualitativos no campo da saúde

Abstract: O metodo de analise de conteudo constitui-se em um conjunto de tecnicas utilizadas na analise de dados qualitativos. Percebe-se, porem, que existe por parte do pesquisador iniciante ou do nao familiarizado com estas tecnicas, dificuldades em relacao ao entendimento e aplicacao do metodo. Assim sendo, objetivou-se neste trabalho, apresentar de maneira clara, conceitos e aspectos importantes constantes do metodo de analise de conteudo e discutir alguns de seus pontos centrais. O metodo de analise de conteudo foi sistematizado na primeira metade do seculo XX e a principio foi importante ferramenta na busca dos sentidos dos artigos e propagandas da imprensa escrita nos Estados Unidos, sendo hoje um metodo amplamente utilizado em pesquisas cientificas no campo da saude.

An Adapted Version of the U.S. Department of Agriculture Food Insecurity Module Is a Valid Tool for Assessing Household Food Insecurity in Campinas, Brazil

Abstract: Until recently, Brazil did not have a national instrument with which to assess household food insecurity (FI). The objectives of this study were as follows: 1) to describe the process of adaptation and validation of the 15-item USDA FI module, and 2) to assess its validity in the city of Campinas. The USDA scale was translated into Portuguese and subsequently tested for content and face validity through content expert and focus groups made up of community members. This was followed by a quantitative validation based on a convenience (n = 125) and a representative (n = 847) sample. Key adaptations involved replacing the term "balanced meal" with "healthy and varied diet," to construct items as questions rather than statements, and to ensure that respondents understood that information would not be used to determine program eligibility. Chronbach's alpha was 0.91 and the scale item response curves were parallel across the 4 household income strata. FI severity level was strongly associated in a dose-response manner (P < 0.001) with income strata and the probability of daily intake of fruits, vegetables, meat/fish, and dairy. These findings were replicated in the 2 independent survey samples. Results indicate that the adapted version of the USDA food insecurity module is valid for the population of Campinas. This validation methodology has now been replicated in urban and/or rural areas of 4 additional states with similar results. Thus, Brazil now has a household food insecurity instrument that can be used to set national goals, to follow progress, and to evaluate its national hunger and poverty eradication programs.

Structure and dynamics of carbon nanoscrolls

Abstract: Carbon nanotube scrolls (CNSs) provide an interesting form of carbon that ideally consists of a single sheet of graphite that is spiral wrapped to form a nanotube. We here use molecular dynamics simulations to investigate CNS formation, stability, and the structural effects due to charge injection. CNS formation is seen to automatically occur when a critical overlap between sheet layers is achieved for the partially curled sheet. We find that charge injection causes unwinding of the CNSs, which might be important for the application of CNSs as nanomechanical actuators.

Fusarium Infection in Hematopoietic Stem Cell Transplant Recipients

Abstract: To characterize the epidemiology and prognostic factors of invasive fusariosis in hematopoietic stem cell transplant (HSCT) recipients, the records of HSCT recipients from 9 hospitals (7 in Brazil and 2 in the United States) were retrospectively reviewed. Sixty-one cases were identified: 54 in allogeneic HSCT recipients and 7 in autologous HSCT recipients. The incidence of fusariosis among allogeneic HSCT recipients varied between a range of 4.21-5.0 cases per 1000 in human leukocyte antigen (HLA)--matched related transplant recipients to 20.19 cases per 1000 in HLA-mismatched transplant recipients. The median time period between transplantation and diagnosis of fusariosis was 48 days. Among allogeneic HSCT recipients, a trimodal distribution was observed: a first peak before engraftment, a second peak at a median of 62 days after transplantation, and a third peak >1 year after transplantation. The actuarial survival was 13% (median, 13 days). Persistent neutropenia was the single prognostic factor for death identified by multivariate analysis.

Método de análisis de contenido: una herramienta para análisis de datos cualitativos en el campo de la salud

Abstract: El metodo de analisis de contenido esta constituido por un conjunto de tecnicas, utilizado en el analisis de datos cualitativos. Se observa que investigadores iniciantes o poco familiarizados con estas tecnicas, encuentran dificultades con relacion a la comprension y a la aplicacion del metodo. Este trabajo tiene como objetivo presentar de forma clara, conceptos y aspectos importantes del metodo de analisis de contenido y discutir algunos puntos centrales. El metodo de analisis de contenido fue sistematizado en la primera mitad del siglo XX y se transformo en una herramienta importante en la busqueda del sentido de los articulos y propagandas de la prensa escrita en los Estados Unidos, siendo hoy un metodo ampliamente utilizado en la investigacion cientifica en el campo de la salud.

Pressure-Induced Colossal Magnetocaloric Effect in MnAs

Abstract: To present day, the maximum magnetocaloric effect (MCE) at room temperature for a magnetic field change of 5 T is 40 J/(kg K) for MnAs. In this Letter we present colossal MCE measurements on MnAs under pressure, reaching values up to 267 J/(kg K), far greater than the magnetic limit arising from the assumption of magnetic field independence of the lattice and electronic entropy contributions. The origin of the effect is the contribution to the entropy variation coming from the lattice through the magnetoelastic coupling.

The Strengths and Difficulties Questionnaire overseas: evaluations and applications of the SDQ beyond Europe.

Abstract: During the few years that have passed since it became available, the Strengths and Difficulties Questionnaire (SDQ) has been extensively evaluated and widely applied to assess behaviour disorders of children and adolescents in European countries. In contrast, relatively few reports have published SDQ results obtained in other parts of the world, although its briefness and availability in over 40 languages make this instrument particularly attractive for international collaborations and cross-cultural comparisons concerning clinical and epidemiological issues. This initial overview summarises some of these non-European experiences with the SDQ by presenting a selection of projects that have either psychometrically evaluated this novel questionnaire, applied it to screen for behaviour disorders, or employed its parent-, teacher- or self-rated versions as research tools. Since a large part of the mentioned studies are ongoing or have only recently been completed, much of the work reported here is still unpublished. Across a huge variety of cultures and languages, experience gained with the SDQ in other continents has supported European evidence of good psychometric properties and clinical utility of this questionnaire. Since worldwide usage of the SDQ can be expected to increase in the future, more international coordination is encouraged, in order to fully exploit the promising potentials of this versatile assessment tool and systematically investigate cross-cultural differences and similarities in child and adolescent behaviour.

Fundamentals on Piezoelectricity

Abstract: The topic of the following chapter is relatively difficult and includes different areas of knowledge. The piezoelectric phenomenon is a complex one and covers concepts of electronics as well as most of the areas of classical physics such as: mechanics, elasticity and strength of materials, thermodynamics, acoustics, wave’s propagation, optics, electrostatics, fluids dynamics, circuit theory, crystallography etc. Probably, only a few disciplines of engineering and science need to be so familiar to so many fields of physics. Current bibliography on this subject is vast though dispersed in research publications, and few of the books on this topic are usually compilations of the authors’ research works. Therefore, they are not thought for didactic purposes and are difficult to understand, even for postgraduates. The objective of this chapter is to help understand the studies and research on piezoelectric sensors and transducers, and their applications. Considering the multidisciplinary nature, this tutorial’s readers can belong to very different disciplines. They can even lack the necessary basic knowledge to understand the concepts of this chapter. This is why the chapter starts providing an overview of the piezoelectric phenomenon, doing consciously initial simplifications, so that the main concepts, which will be progressively introduced, prevail over the accessories. The issues covered in this chapter must be understood without the help of additional texts, which are typically included as references and are necessary to study in depth specific topics. Finally, the quartz crystal is introduced as a microgravimetric sensor to present the reader an application of the piezoelectric phenomenon, which will be dealt with along the following chapters.