Comparative study of the efficacies of nine assay methods for the dextransucrase synthesis of dextran

A comparative study of nine assay methods for dextransucrase and related enzymes has been made. A relatively widespread method for the reaction of dextransucrase with sucrose is the measurement of the reducing value of D-fructose by alkaline 3,5-dinitrosalicylate (DNS) and thereby the amount of D-glucose incorporated into dextran. Another method is the reaction with C-14-sucrose with the addition of an aliquot to Whatman 3MM paper squares that are washed three times with methanol to remove C-14-D-fructose and unreacted C-14-sucrose, followed by counting of C-14-dextran on the paper by liquid scintillation counting (LSC). It is shown that both methods give erroneous results. The DNS reducing value method gives extremely high values due to over-oxidation of both D-fructose and dextran, and the C-14-paper square method gives significantly low values due to the removal of some of the C-14-dextran from the paper by methanol washes. In the present study, we have examined nine methods and find two that give values that are identical and are an accurate measurement of the dextransucrase reaction. They are (1) a C-14-sucrose/dextransucrase digest in which dextran is precipitated three times with three volumes of ethanol, dissolved in water, and added to paper and counted in a toluene cocktail by LSC: and (2) precipitation of dextran three times with three volumes of ethanol from a sucrose/dextransucrase digest, dried, and weighed. Four reducing value methods were examined to measure the amount of D-fructose. Three of the four (two DNS methods, one with both dextran and D-fructose and the other with only D-fructose, and the ferricyanide/arsenomolybdate method with is-fructose) gave extremely high values due to over-oxidation of D-fructose, D-glucose, leucrose, and dextran. (C) 2011 Elsevier Ltd. All rights reserved.

Consumption of bottled water by children in the city of Bauru, State of São Paulo, Brazil - A brief communication

Objectives: To determine the consumption of bottled water by children in the city of Bauru, State of São Paulo, Brazil. Methods: A stratified sample of the 17 areas established by the city plan was used to identify a total of 1,000 homes for visitation. Information was collected using a questionnaire concerning the type of water consumed and population demographics. Results: Overall, around 30 percent of all residences used bottled water. Among all households where bottled water was consumed, about 26 percent had children residing. For those with children and bottled water, 81 percent reported to use bottled water for the preparation of the children's foods and beverages. Conclusions: An important percentage of children consume bottled water in the city of Bauru, State of São Paulo, Brazil. Considering previous studies showing that fluoride concentrations vary in bottled water, public health measures should be implemented in order to guarantee adequate levels of fluoride in commercialized water. © 2007, American Association of Public Health Dentistry.

The influence of zero-value subtraction on the performance of two laser fluorescence devices for detecting occlusal caries in vitro

Background. The aim of this study was to evaluate the influence of zero-value subtraction on the performance of two laser fluorescence (LF) devices developed to detect occlusal caries. Methods. The authors selected 119 permanent molars. Two examiners assessed three areas (cuspal, middle and cervical) of both mesial and distal portions of the buccal surface and one occlusal site using an LF device and an LF pen. For each tooth, the authors subtracted the value measured in the cuspal, middle and cervical areas in the buccal surface from the value measured in the respective occlusal site. Results. The authors observed differences among the readings for both devices in the cuspal, middle and cervical areas in the buccal surface as well as differences for both devices with and without the zero-value subtraction in the occlusal surface. When the authors did not perform the zero-value subtraction, they found statistically significant differences for sensitivity and accuracy for the LF device. When this was done with the LF pen, specificity increased and sensitivity decreased significantly. Conclusions. For the LF device, the zero-value subtraction decreased the sensitivity. For this reason, the authors concluded that clinicians can obtain measures with the LF device effectively without using zero-value subtraction. For the LF pen, however, the absence of the zero-value subtraction changed both the sensitivity and specificity, and so the authors concluded that clinicians should not eliminate this step from the procedure. Clinical Implications. When using the LF device, clinicians might not need to perform the zero-value subtraction; however, for the LF pen, clinicians should do so.

Short Communication: In vitro evaluation of the abrasiveness of acidic dentifrices.

AIM: This in vitro study evaluated the abrasiveness of acidic fluoride (F) dentifrices with different F concentrations on bovine enamel. METHODS: Enamel blocks (4.0 x 4.0 mm2, n=120) were selected according to their surface microhardness and divided into 12 groups. Slurries of dentifrices were used containing 0 (placebo), 275, 412, 550 and 1,100 ppm F (pH 4.5 or 7.0), as well as testing two commercial dentifrices (Crest, positive control, 1,100 ppm F and Colgate Baby, 500 ppm F). Enamel blocks were partially protected with an adhesive tape (control area) and then brushed by an automated toothbrushing machine (16,000 strokes). During this process, 0.4 ml of the slurries were injected every 2 mins on the enamel blocks. After toothbrushing, enamel wear was determined by profilometry. STATISTICS: Results were analyzed by ANOVA and Tukey's test (p<0.05). RESULTS: The mean values for pH in the suspensions during treatment were 6.93, 4.32, 7.56 and 8.19 for neutral experimental dentifrices, acidic experimental dentifrices, Crest and Colgate baby, respectively. The abrasiveness of the acidic dentifrices was similar (p<0.05) to the neutral ones, whereas commercial dentifrices yielded lower abrasion (p<0.05). CONCLUSION: It was concluded that a reduction of the pH of dentifrices does not increase their abrasiveness.

Nurse-patient communication while performing home dialysis: The patients' perceptions

This study aimed at describing patients' perception of their communication with nurses when performing home dialysis. Data were collected from interviews guided by the question: What is communication like, between you and nurses, during home dialysis treatment? Results show participants' perception of treatment during home peritoneal dialysis [Continuous ambulatory peritoneal dialysis (CAPD)]; relationship with nurses and family and the effects of treatment on one's existence. Patients can be self-caring and they learn to value the autonomy in their own care. However, some are unable to assume the responsibility for self-care. It was discovered that the connotation of inspection that some participants attributed to the nurse's visits, led to an alienation from the education process in the CAPD education. Findings suggest that effective communication and the development of the relationship of a working partnership with patients is crucial. Improvement in the nurses' communication, aiming at adapting it to the characteristics, limitations and specific needs of each patient, is significant for achieving better outcomes. © 2010 European Dialysis and Transplant Nurses Association/European Renal Care Association.

Effects of extreme cooling methods on mechanical properties and shear bond strength of bilayered porcelain/3Y-TZP specimens

Objectives: This study investigated the effect of extreme cooling methods on the flexural strength, reliability and shear bond strength of veneer porcelain for zirconia. Methods: Vita VM9 porcelain was sintered on zirconia bar specimens and cooled by one of the following methods: inside a switched-off furnace (slow), at room temperature (normal) or immediately by compressed air (fast). Three-point flexural strength tests (FS) were performed on specimens with porcelain under tension (PT, n = 30) and zirconia under tension (ZT, n = 30). Shear bond strength tests (SBS, n = 15) were performed on cylindrical blocks of porcelain, which were applied on zirconia plates. Data were submitted to one-way ANOVA and Tukey's post hoc tests (p < 0.05). Weibull analysis was performed on the PT and ZT configurations. Results: One-way ANOVA for the PT configuration was significant, and Tukey's test revealed that fast cooling leads to significantly higher values (p < 0.01) than the other cooling methods. One-way ANOVA for the ZT configuration was not significant (p = 0.06). Weibull analysis showed that normal cooling had slightly higher reliability for both the PT and ZT configurations. Statistical tests showed that slow cooling decreased the SBS value (p < 0.01) and showed less adhesive fracture modes than the other cooling methods. Clinical Significance: Slow cooling seems to affect the veneer resistance and adhesion to the zirconia core; however, the reliability of fast cooling was slightly lower than that of the other methods. © 2013 Elsevier Ltd.

Approximation of hyperbolic tangent activation function using hybrid methods

Artificial Neural Networks are widely used in various applications in engineering, as such solutions of nonlinear problems. The implementation of this technique in reconfigurable devices is a great challenge to researchers by several factors, such as floating point precision, nonlinear activation function, performance and area used in FPGA. The contribution of this work is the approximation of a nonlinear function used in ANN, the popular hyperbolic tangent activation function. The system architecture is composed of several scenarios that provide a tradeoff of performance, precision and area used in FPGA. The results are compared in different scenarios and with current literature on error analysis, area and system performance. © 2013 IEEE.

Assessment of central venous catheter-associated infections using semi-quantitative or quantitative culture methods

Semiquantitative (Maki) and quantitative (Brun- Buisson) culture techniques were employed in the diagnosis of catheter-related bloodstream infections (CRBSI) in patients who have a short-term central venous catheter (inserted for 30 days). The diagnosis of CRBSI was based on the results of semiquantitative and quantitative culture of material from the removed catheters. Catheter tips (118) from 100 patients were evaluated by both methods. Semiquantitative analysis revealed 34 catheters (28.8%) colonized by ≥15 colonyforming units (cfu), while quantitative cultures (34 catheters, 28.8%) showed the growth of ≥103 cfu/mL. Bacteremia was confirmed in four patients by isolating microorganisms of identical species from both catheters and blood samples. Using the semiquantitative culture technique on short-term central venous catheter tips, we have shown that with a cut-off level of ≥15 cfu, the technique had 100.0% sensitivity, specificity of 68.4%, 25.0% positive predictive value (PPV) and 100.0% negative predictive value (NPV), efficiency of 71.4% and a prevalence of 9.5%. The quantitative method, with a cut-off limit of ≥103 cfu/mL, gave identical values: the sensitivity was 100.0%, specificity 68.4%, positive predictive value (PPV) 25.0%, negative predictive value (NPV) 100.0%, efficiency 71.4% and prevalence 9.5%. We concluded that the semiquantitative and quantitative culture methods, evaluated in parallel, for the first time in Brazil, have similar sensitivity and specificity. Keywords: central venous catheter; semi-quantitative culture; quantitative culture; catheter-related bacteremia.

Cryopreservation of bovine spermatozoa from the epididymal tail using conventional and automated methods

Cryopreservation of sperm is important to preserve the gerrnplasm from animals of genetic value, which can die unexpectedly. This study compares conventional and automated methods of cryopreservation of spermatozoa obtained from the epididymis of bulls post-mortem. Twenty-two epididymides were obtained from a commercial slaughterhouse. Spermatozoa were collected from the tail of the epididymis using the retrograde flow technique. Thus, the samples, which were diluted in 10 ml of extender without glycerol (Botubov (R) I, Botupharma, Botucatu, SP, Brazil), were evaluated on motility, sperm vigor, structural and functional (swelling hypoosmotic test) membrane integrity, mitochondrial activity, sperm viability and ADN fragmentation. The samples were divided into two aliquots and diluted in extender with glycerol (Botubov (R) II, Botupharma, Botucatu, SP, Brazil) at a concentration of 50x10(6) motile sperm/0.5 French straws. One sample was frozen by the conventional method (4 hours at 5 degrees C, in a refrigerator and 20 min in nitrogen vapor) and the other by the automated method (Cryogen (R) Dualflex, Neovet, Uberaba, MG, Brazil). The parameters were higher in all the tests of fresh sperm samples, with the exception of the swelling hypoosmotic test, which showed no significant difference when the results were compared with sperm frozen by the conventional method. The average motility of fresh spermatozoa was 74%, and conventional and automated averages were 29 and 25%, respectively. Therefore, although cryopreservation techniques reduce sperm quality parameters, the viability of the sperm is maintained, and these methods can be used to preserve sperm.

Amazon forest biomass density maps: tackling the uncertainty in carbon emission estimates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterizing background heterogeneity in visual communication

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DEVELOPMENT OF AN ALGORITHM TO ANALYZE CARTOGRAPHIC FEATURES EXTRACTION METHODS IN DIGITAL IMAGES

The algorithm creates a buffer area around the cartographic features of interest in one of the images and compare it with the other one. During the comparison, the algorithm calculates the number of equals and different points and uses it to calculate the statistical values of the analysis. One calculated statistical value is the correctness, which shows the user the percentage of points that were correctly extracted. Another one is the completeness that shows the percentage of points that really belong to the interest feature. And the third value shows the idea of quality obtained by the extraction method, since that in order to calculate the quality the algorithm uses the correctness and completeness previously calculated. All the performed tests using this algorithm were possible to use the statistical values calculated to represent quantitatively the quality obtained by the extraction method executed. So, it is possible to say that the developed algorithm can be used to analyze extraction methods of cartographic features of interest, since that the results obtained were promising.

Avaliação da presença de tecnologias de informação e comunicação no ensino de histologia das universidades de odontologia do estado de São Paulo

In recent decades the rise of the tools of information and communication technology (ICT) has been notorious. Currently ICTs are an important educational tool and is associated with the development of teaching methods courses in basic and higher education. Given the influence that these tools are currently engaged in several sectors, this project aimed to assess the frequency and manifestations of ICT that have been employed in the teaching of histology in the Schools of Dentistry of São Paulo. The virtual page of 43 Higher Education Institutions (HEI) was analyzed to search for links to sites of histology. With this assessment only 4 virtual domains were found which was present a narrow range of virtual tools such as hypertext, graphics, quizzes and lessons in electronic formats. Later, by sending a questionnaire to 46 teachers of histology of the Universities of São Paulo, were analyzed for the presence or absence of a site of discipline, mode and frequency of use of ICTs in education, and the value that teacher attaches to these tools. From the responses obtained were concluded that teachers who have websites in general have no interactivite tools and many seem to ignore the real representation of interactivity in teaching and the possibilities of applications of ICTs. However most teachers recognize the importance of education mediated by virtual tools

Reliability of marginal microleakage assessment by visual and digital methods

The aim of this study was to investigate the reliability of visual and digital methods to assess marginal microleakage in vitro. Materials and Methods: Typical Class V preparations were made in bovine teeth and filled with composite resin. After dye penetration (0.5% basic fuchsin), teeth were sectioned and the 53 obtained fragments were assessed according to visual (stereomicroscope) and digital methods (Image Tool Software ® -ITS) (University of Texas Health Science Center-San Antonio Dental School, USA). Two calibrated examiners (A and B) evaluated dye penetration, by means of a stereomicroscope with ×20 magnification (scores), and by the ITS (millimeters). The intra- and inter-examiner agreement was estimated according to Kappa statistics (κ), and intraclass correlation coefficient (ρ). Results: In relation to the visual method, the intra-examiner agreement was almost perfect (κA = 0.87) and substantial (κB = 0.76), respectively to the examiner A and B. The inter-examiner agreement showed an almost perfect reliability (κ = 0.84). For the digital method, the intra-examiner agreement was almost perfect for both examiners and equal to ρ = 0.99, and so was the inter-examiner agreement value. Conclusion: Visual (stereomicroscope) and digital methods (ITS) showed high levels of intra- and inter-examiner reproducibility when marginal microleakage was assessed.

Periapical Repair Following Endodontic Surgery: Two- andThree-Dimensional Imaging Evaluation Methods

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)