99 resultados para SPECTROSCOPIC CHARACTERIZATION


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AbstractINTRODUCTIONThe aim of this study was to detect the prevalence of the extended-spectrum beta-lactamase (ESBL)-encoding CTX-M gene in Escherichia coliisolates.METHODS:Phenotypic screening of 376 E. coli isolates for ESBL was conducted using disk diffusion. ESBL-producing isolates were tested using PCR and specific primers. The blaCTX-M cluster was identified using the RFLP method, and its genotype was sequenced.RESULTS:From 202 ESBL-producing E. coli , 185 (91.5%) possessed CTX-M genes. CTX-M-1 subtypes were found in 98% of the isolates. The blaCTX-M gene was identical to CTX-M-15.CONCLUSIONS:A high prevalence of CTX-M-1-producing E. coli apparently exists in Shiraz, Iran.

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ABSTRACTINTRODUCTION:In this study, the molecular characteristics of group A rotavirus (RVA) were compared in samples obtained before and after RVA vaccine-introduction in Brazil.METHODS:Eighty samples were screened for the presence of RVA. Positive samples were molecularly analyzed.RESULTS:RVA positivity was 16.9%, with a predominance of G2P[4]. Periods: pre-vaccination: predominance of IId (G1), IId (G2) lineages, and I1 and E1 genotypes; post-vaccination: predominance of Ib (G1), IIa, and IIc (G2) lineages and I2 and E2 genotypes.CONCLUSIONS:Although changes in RVA-circulation pattern were observed in the post-vaccination period, it could not be attributed to vaccination process.

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Abstract: INTRODUCTION Characterization of Mycobacterium tuberculosis (MTB) isolates by DNA fingerprinting has contributed to tuberculosis (TB) control. The aim of this study was to determine the genetic diversity of MTB isolates from Tehran province in Iran. METHODS MTB isolates from 60 Iranian and 10 Afghan TB patients were fingerprinted by standard IS6110-restriction fragment length polymorphism (RFLP) analysis and spoligotyping. RESULTS The copy number of IS6110 ranged from 10-24 per isolate. The isolates were classified into 22 clusters showing ≥ 80% similarity by RFLP analysis. Fourteen multidrug-resistant (MDR) isolates were grouped into 4 IS6110-RFLP clusters, with 10 isolates [71% (95% CI: 45-89%)] in 1 cluster, suggesting a possible epidemiological linkage. Eighteen Iranian isolates showed ≥ 80% similarity with Afghan isolates. There were no strains with identical fingerprints. Spoligotyping of 70 isolates produced 23 distinct patterns. Sixty (85.7%) isolates were grouped into 13 clusters, while the remaining 10 isolates (14.2%) were not clustered. Ural (formerly Haarlem4) (n = 22, 31.4%) was the most common family followed by Central Asian strain (CAS) (n = 18, 25.7%) and T (n = 9, 12.8%) families. Only 1strain was characterized as having the Beijing genotype. Among 60 Iranian and 10 Afghan MTB isolates, 25% (95% CI: 16-37) and 70% (95% CI: 39-89) were categorized as Ural lineage, respectively. CONCLUSIONS A higher prevalence of Ural family MTB isolates among Afghan patients than among Iranian patients suggests the possible transmission of this lineage following the immigration of Afghans to Iran.

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PURPOSE: To determine the incidence and characteristics of nonimmune hydrops fetalis in the newborn population. METHOD: A retrospective study of the period between 1996 and 2000, including all newborns with a prenatal or early neonatal diagnosis of nonimmune hydrops fetalis, based on clinical history, physical examination, and laboratory evaluation. The following were analyzed: prenatal follow-up, delivery type, gender, birth weight, gestational age, presence of perinatal asphyxia, nutritional classification, etiopathic diagnosis, length of hospital stay, mortality, and age at death. RESULTS: A total of 47 newborns with hydrops fetalis (0.42% of live births), 18 (38.3%) with the immune form and 29 (61.7%) with the nonimmune form, were selected for study. The incidence of nonimmune hydrops fetalis was 1 per 414 neonates. Data was obtained from 21 newborns, with the following characteristics: 19 (90.5%) were suspected from prenatal diagnosis, 18 (85.7%) were born by cesarean delivery, 15 (71.4%) were female, and 10 (47.6%) were asphyxiated. The average weight was 2665.9 g, and the average gestational age was 35 3/7 weeks; 14 (66.6%) were preterm; 18 (85.0 %) appropriate delivery time; and 3 (14.3%) were large for gestational age. The etiopathic diagnosis was determined for 62%, which included cardiovascular (19.0%), infectious (9.5%), placental (4.8%), hematologic (4.7%), genitourinary (4.8%), and tumoral causes (4.8%), and there was a combination of causes in 9.5%. The etiology was classified as idiopathic in 38%. The length of hospital stay was 26.6 ± 23.6 days, and the mortality rate was 52.4%. CONCLUSIONS: The establishment of a suitable etiopathic diagnosis associated with prenatal detection of nonimmune hydrops fetalis can be an important step in reducing the neonatal mortality rate from this condition.

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Many potentially harmful pesticides for both human health and the environment are used in Brazilian Amazon. However, no scientific datum on pesticide usage is presently available for this region. Consequently, it is difficult to assess which substances arc used and in which quantities. As an important premise for future work on pesticide contamination in the county of Santarém (State of Pará, Brazil), a survey was conducted in order to qualify and quantify the use of some pesticides in this region. This investigation was made between January and March 1997 and August and October 1998 and revealed use of several organophosphates, synthetic pyrethroids and carbamates insecticides. Furthermore, many herbicides and fungicides were listed. These pesticides are used for agriculture, domestic, and sanitary programs. This paper also provides a first estimation of quantities of some insecticides commonly used in agriculture (chlorpyrifos, malathion, metamidophos and methyl-parathion). The annual consumption for these four compounds is estimated at ca. 1 910 kg. Organophosphate insecticide consumption in the county of Santarém seems to be lower than the Brazilian average in terms of «per capita» and «per agricultural area» consumptions. Nevertheless, this county uses toxic substances on sensitive environments such as floodplains (várzeas), making relevant a thorough study on the potential contamination of this environment and its biota.

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The present work aims to update a series of information about the regional fishing production, by presenting and characterizing the contribution of the different sub-systems of the Amazon basin to the catch landed at the main fishing market of Manaus, Brazil, from 1994 to 1996. Collectors specifically hired for this function registered key information on the fisheries. Thirty nine types or groups of fish were found in the fishing production landed. Jaraqui (Semaprochilodus spp.), curimatã (Prochilodus nigricans), pacu (Myleinae), matrinchã (Brycon cephalus), sardine (Triportheus spp.), aracu (Anostomidae) and tambaqui (Colossoma macropomum) were the most important items during three consecutive years. In 1994 these items summed up 91.6% of the total production; in 1995 and 1996 these values were, respectively, 85.3% and 86.4% of the total production. Tambaqui landed decreased remarkably during the period 1976-1996. There was a strong seasonal component in the production of the main species; jaraqui and matrinchã were mostly landed between April and June, while curimatã, pacu, and sardine were mostly landed during the dry season. Other important items showed a strong inter-annual variation in their production. The fishing production landed came mostly from the sub-system of the Purus River (around 30% of the total production). The subsystem of the Medium-Solimões contributed with an average of 15% and the sub-systems of the Madeira, Lower-Solimões, Upper-Amazon and Juruá, together contributed with 11.5% of the total production landed. Finally, the remaining sub-systems contributed with only 7.6% of the production.

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Three coumarins, 5-methoxypsoralene, xanthyletin, and (-)-marmesin, have been isolated from the ethanolic extract of the stem of the Amazonian plant Brosimum potabile. The structures were determined on the basis of NMR analyses and by comparison with spectroscopic data in the literature. The analysis of the hexane fractions by GC-MS in EIMS mode suggested the presence of (1-methylpentyl)-benzene; α,α-dimethyl-4-(1-methylethyl)-benzenemethanol; 1-methyl-3,5-bis(1-methylethyl)-benzene; urs-12-ene; chola-5,22-dien-3β-ol; cholesta-4,6-dien-3β-ol; sitosteryl 9(Z)-octadecenoate; cholesta-5,22-dien-3β-ol; cholesta-4,6,22-trien-3-one; and cholesta-4,22-dien-3-one. NMR data of other hexane fractions indicated the presence of 3β-acetoxy-lup-12,20(29)-diene; 3β-acetoxy-olean-12-ene; 3β-acetoxy-urs-12-ene; and adian-5-ene. All these compounds are first described in B. potabile.

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Land cover changes over time as a result of human activity. Nowadays deforestation may be considered one of the main environmental problems. The objective of this study was to identify and characterize changes to forest cover in Venezuela between 2005-2010. Two maps of deforestation hot spots were generated on the basis of MODIS data, one using digital techniques and the other by means of direct visual interpretation by experts. These maps were validated against Landsat ETM+ images. The accuracy of the map obtained digitally was estimated by means of a confusion matrix. The overall accuracy of the maps obtained digitally was 92.5%. Expert opinions regarding the hot spots permitted the causes of deforestation to be identified. The main processes of deforestation were concentrated to the north of the Orinoco River, where 8.63% of the country's forests are located. In this region, some places registered an average annual forest change rate of between 0.72% and 2.95%, above the forest change rate for the country as a whole (0.61%). The main causes of deforestation for the period evaluated were agricultural and livestock activities (47.9%), particularly family subsistence farming and extensive farming which were carried out in 94% of the identified areas.

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Mapania belongs to Mapanioideae, a quite controversial subfamily in Cyperaceae due to the existence of unusual characters in both reproductive and vegetative organs. The genus is represented by seven species in Northern Brazil but taxonomic valuable information related to the leaf organs is still unknown. The present study aimed the anatomical description of the leaf organs (either basal leaves or cataphylls and involucral bracts) of three representative Brazilian species of Mapania. Samples of cataphylls, basal leaves and involucral bracts were sectioned and stained for observations under light microscopy. The involucral bracts provide the most elucidative characters (ten) to distinguish the three species The basal leaves provides six distinguishing characters and are useful to M. macrophylla and M. pycnostachya, as they are absent in M. sylvatica. Mesophyll arrangement in the involucral bracts supports the circumscription of M. macrophylla and M. pycnostachya in M. sect. Pycnocephala and of M. sylvatica in M. sect. Mapania. Some features as thin-walled epidermal cells, stomata level and aerenchyma were considered to be adaptive to the humid environment in which the species occur. The translucent cells are here considered as aerenchyma precursors and a supportive function is assumed for the bulliform cells on the basal leaves and involucral bracts. No silica bodies were found which confirm it as a diagnostic character of Mapania among Hypolytreae genera.