998 resultados para 234Th int
Resumo:
The present invention provides assay devices having a unitary body with an exterior surface, the unitary body being substantially transparent to visible light and formed from a material having a refractive index in the range 1.26 to 1.40, the refractive index being measured at 20 °C with light of wavelength 589 nm, and wherein the unitary body is formed from a hydrophobic material, and at least two capillary bores extending internally along the unitary body, wherein at least a portion of the surface of each capillary bore includes a hydrophilic layer for retaining an assay reagent, and wherein the hydrophilic layer is also substantially transparent to visible light to allow optical interrogation of the capillary bores through the capillary wall. The present invention also provides assay systems including such assay devices, methods of performing an assay using such assay devices and method of method for manufacturing such assay devices.
Resumo:
The objective of this study was to verify if differences in the design of internal hex (IH) and internal conical (IC) connection implant systems influence fracture resistance under oblique compressive forces. Twenty implant-abutment assemblies were utilized: 10 with IH connections and 10 with IC connections. Maximum deformation force for IC implants (90.58 +/- 6.72 kgf) was statistically higher than that for IH implants (83.73 +/- 4.94 kgf) (P = .0182). Fracture force for the IH implants was 79.86 +/- 4.77 kgf. None of the IC implants fractured. The friction-locking mechanics and the solid design of the IC abutments provided greater resistance to deformation and fracture under oblique compressive loading when compared to the IH abutments. Int J Prosthodont 2009;22:283-286.
Resumo:
Purpose: The aim of this study was to evaluate, through fluorescence analysis, the effect that different interimplant distances, after prosthetic restoration, will have on bone remodeling in submerged and nonsubmerged implants restored with a ""platform switch."" Materials and Methods: Fifty-six Ankylos implants were placed 1.5 mm subcrestally in seven dogs. The implants were placed so that two fixed prostheses, with three interimplant contacts separated by 1-mm, 2-mm, and 3-mm distances, could be fabricated for each side of the mandible. The sides and the positions of the groups were selected randomly. To better evaluate bone remodeling, calcein green was injected 3 days before placement of the prostheses at 12 weeks postimplantation. At 3 days before sacrifice (8 weeks postloading), alizarin red was injected. The amounts of remodeled bone within the different interimplant areas were compared statistically before and after loading in submerged and nonsubmerged implants. Results: Statistically significant differences existed in the percentage of remodeled bone seen in the different regions. Mean percentages of remodeled bone in the submerged and nonsubmerged groups, respectively, were as follows: for the 1-mm distance, 23.0% +/- 0.05% and 23.1% +/- 0.03% preloading and 27.0% +/- 0.03% and 25.2% +/- 0.04% postloading, for the 2-mm distance, 18.2% +/- 0.05% and 18.1% +/- 0.04% preloading and 21.3% +/- 0.07% and 19.9% +/- 0.03% postloading, for the 3-mm distance, 18.3% +/- 0.03% and 18.3% +/- 0.03% preloading and 18.8% +/- 0.04% and 19.8% +/- 0.04% postloading, for distal-extension regions, 16.6% +/- 0.02% and 17.4% +/- 0.04% preloading and 17.0% +/- 0.04% and 18.4% +/- 0.04% postloading. Conclusions: Based upon this animal study, loading increases bone formation for submerged or nonsubmerged implants, and the interimplant distance of 1 mm appears to result in more pronounced bone remodeling than the 2-mm or 3-mm distances in implants with a ""platform switch."" INT J ORAL MAXILLOFAC IMPLANTS 2009;24:257-266
Resumo:
Hopeless retained primary teeth without permanent successors represent a restorative challenge for clinicians, along with esthetic and functional problems for patients. While various treatment approaches for congenitally missing teeth have been proposed, the replacement of a missing tooth with a dental implant offers specific advantages, such as preservation of the alveolar crest and elimination of the need to restore the adjacent teeth, over other options for tooth replacement. The aim of this article was to illustrate the surgical and prosthetic treatment with implants of a patient with primary teeth without permanent successors. INT J ORAL MAXILLOFAC IMPLANTS 2009;24:151-154
Resumo:
The purpose of this study was to analyze and compare scanning electron microscopy (SEM) observations of ball attachments that had been worn by patients during three periods of clinical use. One hundred forty-four specimens of ball anchor attachments (gold alloy matrix and titanium patrix) were studied by SEM after periods of approximately 1, 3.5, and 8 years of clinical use. Twenty new attachment components were examined as controls. SEM images revealed signs of mechanical wear for the ball attachments studied. The surfaces of the titanium patrix were associated primarily with roughening after short-term use, whereas surfaces of the gold alloy matrix showed wear, roughening, and loss of microscopic material in the form of flakes. Severe mechanical wear on both surfaces was noted after longer periods of use. The mechanical changes were not correlated with patient-mediated observations regarding the time-dependent retentive efficacy of the attachments. One year of clinical wear appeared to have limited effect on the ball attachment tested. Conversely, longer periods of use led to marked modifications in shape of the matrix and patrix components. Int J Prosthodont 2011;24:270-272.
Resumo:
Purpose: The aim of this study was to evaluate, through histomorphometric analysis, the effect that different loading times would have on the bone response around implants. Materials and Methods: Three Replace Select implants were placed on each side of the mandible in eight dogs (n = 48 implants). One pair of implants was selected for an immediate loading protocol (IL). After 7 days, the second pair of implants received prostheses for an early loading protocol (EL). Fourteen days after implant placement, the third pair of implants received prostheses for advanced early loading (AEL). Following 12 weeks of prosthetics, counted following the positioning of the metallic crowns for the AEL group, the animals were sacrificed and the specimens were prepared for histomorphometric analysis. The differences between loading time in the following parameters were evaluated through analysis of variance: bone-to-implant contact, bone density, and crestal bone loss. Results: The mean percentage of bone-to-implant contact for IL was 77.9% +/- 1.71%, for EL it was 79.25% +/- 2.11%, and for AEL it was 79.42% +/- 1.49%. The mean percentage of bone density for IL was 69.97% +/- 3.81%, for EL it was 69.23% +/- 5.68%, and for AEL it was 69.19% +/- 2.90%. Mean crestal bone loss was 1.57 +/- 0.22 mm for IL, 1.23 +/- 0.19 mm for EL, and 1.17 +/- 0.32 mm for AEL. There was no statistical difference for any of the parameters evaluated (P > .05). Conclusion: Different early loading times did not seem to significantly affect the bone response around dental implants. INT J ORAL MAXILLOFAC IMPLANTS 2010;25:473-481
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BACKGROUND: Mycobacterium tuberculosis genotypes resistant to reactive nitrogen intermediates (RNI) predominate in certain urban communities, suggesting that this phenotype influences disease transmission. OBJECTIVE: To compare different M. tuberculosis genotypes for resistance to RNI generated in vitro. DESIGN: We genotyped 420 M. tuberculosis isolates from a neighborhood in Sao Paulo, Brazil, and analyzed them for susceptibility to RNI generated in acidified sodium nitrite (ASN) solution. RESULTS: Seventy-one (43%) of 167 recent-infection strains and 68 (43%) of 158 endogenous infection strains showed moderate- to high-level ASN resistance. CONCLUSION: ASN resistance of M. tuberculosis is not necessarily a determining factor for enhanced transmission.
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The incidence of Listeria monocytogenes in three cheese manufacturing plants from the northeastern region of Sao Paulo, Brazil, was evaluated from October 2008 to September 2009. L. monocytogenes was found in samples from two plants, at percentages of 13.3% (n = 128) and 9.6% (n = 114). Samples of raw and pasteurized milk, water, and Minas Frescal cheese were negative for L. monocyto genes, although the pathogen was isolated from the surface of Prato cheese and in brine from one of the plants evaluated. L. monocytogenes was also isolated from different sites of the facilities, mainly in non food contact surfaces such as drains, floors, and platforms. Serotype 4b was the most predominant in the plants studied. The results of this study indicate the need for control strategies to prevent the dispersion of L. monocytogenes in the environment of cheese manufacturing plants.
Resumo:
Sampling protocols for detecting Salmonella on poultry differ among various countries. In the United States, the U.S. Department of Agriculture Food Safety and Inspection Service dictates that whole broiler carcasses should be rinsed with 400 ml of 1% buffered peptone water, whereas in the European Union 25-g samples composed of neck skin from three carcasses are evaluated. The purpose of this study was to evaluate a whole carcass rinse (WCR) and a neck skin excision (NS) procedure for Salmonella and Escherichia coli isolation from the same broiler carcass. Carcasses were obtained from three broiler processing plants. The skin around the neck area was aseptically removed and bagged separately from the carcass, and microbiological analysis was performed. The corresponding carcass was bagged and a WCR sample was evaluated. No significant difference (alpha <= 0.05) in Salmonella prevalence was found between the samples processed by the two methods, but both procedures produced many false-negative Salmonella results. Prechill, 37% (66 carcasses), 28% (50 carcasses), and 51% (91 carcasses) of the 180 carcasses examined were positive for Salmonella by WCR, NS, and both procedures combined, respectively. Postchill, 3% (5 carcasses), 7% (12 carcasses), and 10% (17 carcasses) of the 177 carcasses examined were positive for Salmonella by the WCR, NS, and combination of both procedures, respectively. Prechill, E. coli plus coliform counts were 3.0 and 2.6 log CFU/ml by the WCR and NS methods, respectively. Postchill. E. coli plus coliform counts were 1.7 and 1.4 log CFU/ml by the WCR and NS methods, respectively.
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Cavernous sinus thrombosis is a severe encephalic complication of the cervicofacial infections that can lead to death if not treated in adequate time. Among the several etiologies related to the development of this infection, myiasis has not been reported, enforcing the importance of the report of a case of thrombosis of the cavernous sinus developed from a facial myiasis. (Quintessence Int 2010;41:e72-e74)
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We developed a general method for determination of water production rates from groundbased visual observations and applied it to Comet Hale-Bopp. Our main objective is to extend the method to include total visual magnitude observations obtained with CCD detector and V filter in the analysis of total visual magnitudes. We compare the CCD V-broadband careful observations of Liller [Liller, W. Pre-perihelion CCD photometry of Comet 1995 01 (Hale-Bopp). Planet. Space Sci. 45, 1505-1513, 1997; Liller, W. CCD photometry of Comet C/1995 O1 (Hale-Bopp): 1995-2000. Int. Comet Quart. 23(3), 93-97, 2001] with the total visual magnitude observations from experienced international observers found in the International Comet Quarterly (ICQ) archive. A data set of similar to 400 CCD observations covering about the same 6 years time span of the similar to 12,000 ICQ selected total visual magnitude observations were used in the analysis. A least-square method applied to the water production rates, yields power laws as a function of the heliocentric distances for the pre- and post-perihelion phases. The average dimension of the nucleus as well as its effective active area is determined and compared with values published in the literature. (C) 2009 COSPAR. Published by Elsevier Ltd. All rights reserved.
Resumo:
Small local earthquakes from two aftershock sequences in Porto dos GaA(0)chos, Amazon craton-Brazil, were used to estimate the coda wave attenuation in the frequency band of 1 to 24 Hz. The time-domain coda-decay method of a single backscattering model is employed to estimate frequency dependence of the quality factor (Q (c)) of coda waves modeled usingwhere Q (0) is the coda quality factor at frequency of 1 Hz and eta is the frequency parameter. We also used the independent frequency model approach (Morozov, Geophys J Int, 175:239-252, 2008), based in the temporal attenuation coefficient, chi(f) instead of Q(f), given by the equation for the calculation of the geometrical attenuation (gamma) and effective attenuation Q (c) values have been computed at central frequencies (and band) of 1.5 (1-2), 3.0 (2-4), 6.0 (4-8), 9.0 (6-12), 12 (8-16), and 18 (12-24) Hz for five different datasets selected according to the geotectonic environment as well as the ability to sample shallow or deeper structures, particularly the sediments of the Parecis basin and the crystalline basement of the Amazon craton. For the Parecis basin for the surrounding shield and for the whole region of Porto dos GaA(0)chos Using the independent frequency model, we found: for the cratonic zone, gamma = 0.014 s (-aEuro parts per thousand 1), nu a parts per thousand 1.12; for the basin zone with sediments of similar to 500 m, gamma = 0.031 s (-aEuro parts per thousand 1), nu a parts per thousand 1.27; and for the Parecis basin with sediments of similar to 1,000 m, gamma = 0.047 s (-aEuro parts per thousand 1), nu a parts per thousand 1.42. Analysis of the attenuation factor (Q (c)) for different values of the geometrical spreading parameter (nu) indicated that an increase of nu generally causes an increase in Q (c), both in the basin as well as in the craton. But the differences in the attenuation between different geological environments are maintained for different models of geometrical spreading. It was shown that the energy of coda waves is attenuated more strongly in the sediments, (in the deepest part of the basin), than in the basement, (in the craton). Thus, the coda wave analysis can contribute to studies of geological structures in the upper crust, as the average coda quality factor is dependent on the thickness of sedimentary layer.
Resumo:
Pilostyles species (Apodanthaceae) are endoparasites in stems of the plant family Fabaceae. The body comprises masses of parenchyma in the host bark and cortex, with sinkers, comprising groups of twisted tracheal elements surrounded by parenchyma that enter the secondary xylem of the host plant. Here we report for the first time the effects of Pilostyles parasitism on host secondary xylem. We obtained healthy and parasitized stems from Mimosa foliolosa, M. maguirei and M. setosa and compared vessel element length, fiber length, vessel diameter and vessel frequency, measured through digital imaging. Also, tree height and girth were compared between healthy and parasitized M. setosa. When parasitized, plant size, vessel diameter, vessel element length and fiber length are all less than in healthy plants. Also, vessel frequency is greater and vessels are narrower in parasitized stems. These responses to parasitism are similar to those observed in stressed plants. Thus, hosts respond to the parasite by changing its wood micromorphology in favour of increased hydraulic safety.
Resumo:
This Study evaluated the species-level taxonomy and phylogenetic relationship among Kumanoa species from Brazil with other regions of the world based on the plastid-encoded RUBISCO large Subunit gene (rhcL). Partial rbcL sequences were obtained for 11 Kulnanoa specimens. Eight species are recognised from Brazil on the basis of molecular and morphological data: seven previously described (K abilii, K ambignia, K. breviarticulata, K. cipoensis, K. equisetoidea, K. globospora and K procarpa) and a new species here proposed (K. amazonensis sp. nov. Necchi & Vis). The new species has reduced and dense whorls but differs from the two closest related species in lacking secondary fascicles. Previously proposed infrageneric categories were not supported by the molecular data. Species described and endemic (K. breviarticulata, K. cipoensis, K equiseloidea and K. procarpa) to Brazil are not grouped together but are variously related to other species from North America, Europe and Australasia. With the species recognised in this study using molecular and morphological data and those previously distinguished by morphology, 13 species of Kumanoa are Currently documented from Brazil.
Resumo:
A new method is presented to prepare anatomical slides of plant materials including a combination of soft and hard tissues, such as stems with cambial variants, arboreal monocotyledons, and tree bark The method integrates previous techniques aimed at softening the samples and making them thereby more homogeneous, with the use of anti-tearing polystyrene foam solution In addition, we suggest two other alternatives to protect the sections from tearing adhesive tape and/or Mayer`s albumin adhesive, both combined with the polystyrene foam solution This solution is cheap and easy to make by dissolving any packaging polystyrene m butyl acetate It is applied before each section is cut on a sliding microtome and ensures that all the tissues in the section will hold together This novel microtechnical procedure will facilitate the study of heterogeneous plant portions, as shown in some illustrated examples