Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Eur Radiol ; 33(1): 417-428, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35895121

RESUMO

OBJECTIVES: To evaluate the feasibility of contrast-enhanced mammography (CEM)-guided biopsy at Hospital del Mar, a Spanish university hospital. METHODS: We retrospectively reviewed all consecutive women with a suspicious enhancing finding eligible for CEM-guided biopsy, who were prospectively enrolled in a pre-marketing clinical validation and feasibility study (October 2019 to September 2021). CEM-guided biopsy is a stereotactic-based procedure that, by using intravenous iodinated contrast media administration and dual-energy acquisition, provides localisation of enhancing lesions. All the biopsies were performed using a vacuum-assisted device. We collected procedural characteristics (patient position and type of approach), and histopathological results. Feasibility endpoints included success (visualisation of the enhancing lesion, post-procedural biopsy changes and clip placement), procedural time, number of scout acquisitions and complications. RESULTS: A total of 66 suspicious enhancing lesions (18.0% foci, 44.0% mass, 38.0% non-mass enhancement; median size 8.5 mm) in 64 patients (median age 59 years, mostly minimal [48.4%] or mild [32.8%] background parenchymal enhancement) were referred for CEM-guided biopsy in the study period. The success rate was 63/66 (95.4%). Amongst successful procedures, patients were most frequently seated (52/63, 82.5%) and the preferred approach was horizontal (48/63, 76.2%). Median total time per procedure was 15 min. Median number of acquisitions needed before targeting was 2 (range 1-4). Complications consisted of hematoma (17/63, 27%) and vasovagal reaction (2/63, 3.2%). At histology, the malignancy rate was 25/63 (39.7%). CONCLUSION: In this first patient series, CEM-guided breast biopsy was feasible, with success and complication rates similar to those previously reported for magnetic resonance guidance. KEY POINTS: • CEM may be used to guide biopsy of enhancing lesions through a stereotactic-based procedure combined with intravenous iodinated contrast media administration and dual-energy acquisition. • In this first patient series (n = 64), the success rate of CEM-guided biopsy was above 95%, the only complications were hematoma (22.2%) and vasovagal reaction (3.2%), and median total time per procedure was 15 min. • CEM-guided biopsy is feasible and could potentially be a widely available biopsy technique for enhancing-only lesions.


Assuntos
Neoplasias da Mama , Compostos de Iodo , Humanos , Feminino , Pessoa de Meia-Idade , Meios de Contraste/farmacologia , Estudos Retrospectivos , Estudos de Viabilidade , Mamografia , Biópsia , Mama/diagnóstico por imagem , Mama/patologia , Hematoma/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Biópsia Guiada por Imagem/métodos
2.
Genet Mol Res ; 16(3)2017 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-28829892

RESUMO

Hyptis pectinata, popularly known as 'sambacaitá' or 'canudinho', is a medicinal and aromatic species widely used in the Brazilian Northeast. In Sergipe, the excessive extraction of natural resources may reduce the genetic variability of native plants. Thus, molecular markers have frequently been applied to the characterization of genetic diversity as the basis for germplasm conservation and breeding programs. The objective of the present study was to evaluate the genetic diversity of H. pectinata plants collected in different municipalities of the State of Sergipe using ISSR molecular markers. Thirty-four primers were tested, nine of which were selected for providing reproducible and analyzable amplification products, resulting in 67 polymorphic bands. The expected heterozygosity ranged from 0.32 to 0.45, with a mean of 0.39. Polymorphism information content was of 0.49, which classifies the markers as moderately informative. A dendrogram was constructed using unweighted pair group method with arithmetic mean, forming three clusters: Cluster I (79 plants); Cluster II (4 plants); and Cluster III (2 plants). Jaccard's similarity coefficients ranged from 0.06 to 0.98. The plants SAM-117 and SAM-119 presented greater similarity. Conversely, SAM-107 and SAM-171 were the most genetically distant. In general, H. pectinata plants collected in the State of Sergipe presented low to moderate genetic diversity.


Assuntos
Hyptis/genética , Repetições de Microssatélites , Polimorfismo Genético , Melhoramento Vegetal
3.
Genet Mol Res ; 16(2)2017 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-28525657

RESUMO

Brazil has about 300 Croton species in different types of vegetation. Croton tetradenius Baill., which is endemic to the Northeast region and predominant in the Caatinga vegetation, stands out among the several species of this genus. Considering the importance of knowing the genetic variability of a species, the objective of this study was to analyze the genetic diversity of the genotypes of natural populations of C. tetradenius in the State of Sergipe, using ISSR molecular markers. Forty individuals were sampled in four natural populations of the State of Sergipe, Brazil. Thirteen primers were used for DNA amplification using ISSR-PCR, totaling 77 amplified fragments, of which 94.8% were polymorphic. Results of the cluster analysis obtained by the Jaccard's similarity index, using the UPGMA method, resulted in the formation of six distinct clusters. Analysis of molecular variance (AMOVA), used to estimate the genetic variability among populations, revealed significant genetic variance (P < 0.01) between and within the studied populations, and most of the genetic diversity was found (87%) within populations. According to the Jaccard's similarity index, none of the studied plants was genetically identical. CTE210 and CTE305 presented high similarity index (0.76), while CTE105 presented low similarity index (<0.16) with all related individuals. ISSR markers were efficient and allowed the formation of a molecular profile, and had sufficient polymorphism to estimate the genetic variability between the accessions of the studied populations.


Assuntos
Croton/genética , Repetições de Microssatélites , Polimorfismo Genético
4.
Eur J Radiol ; 171: 111312, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38237520

RESUMO

BACKGROUND: Contrast-enhanced breast MRI and recently also contrast-enhanced mammography (CEM) are available for breast imaging. The aim of the current overview is to explore existing evidence and ongoing challenges of contrast-enhanced breast imaging. METHODS: This narrative provides an introduction to the contrast-enhanced breast imaging modalities breast MRI and CEM. Underlying principle, techniques and BI-RADS reporting of both techniques are described and compared, and the following indications and ongoing challenges are discussed: problem-solving, high-risk screening, supplemental screening in women with extremely dense breast tissue, breast implants, neoadjuvant systemic therapy (NST) response monitoring, MRI-guided and CEM- guided biopsy. RESULTS: Technique and reporting for breast MRI are standardised, for the newer CEM standardisation is in progress. Similarly, compared to other modalities, breast MRI is well established as superior for problem-solving, screening women at high risk, screening women with extremely dense breast tissue or with implants; and for monitoring response to NST. Furthermore, MRI-guided biopsy is a reliable technique with low long-term false negative rates. For CEM, data is as yet either absent or limited, but existing results in these settings are promising. CONCLUSION: Contrast-enhanced breast imaging achieves highest diagnostic performance and should be considered essential. Of the two contrast-enhanced modalities, evidence of breast MRI superiority is ample, and preliminary results on CEM are promising, yet CEM warrants further study.


Assuntos
Neoplasias da Mama , Mamografia , Feminino , Humanos , Mama/diagnóstico por imagem , Densidade da Mama , Neoplasias da Mama/diagnóstico por imagem , Meios de Contraste , Imageamento por Ressonância Magnética/métodos , Mamografia/métodos
5.
Phys Chem Chem Phys ; 13(1): 207-13, 2011 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-21188845

RESUMO

The use of non-volatile electrolytes and fully organic dyes are key issues in the development of stable dye-sensitized solar cells (DSCs). In this work we explore the performance of ZnO-based DSCs sensitized with an indoline derivative coded D149 in the presence of a pure ionic-liquid electrolyte. Commercial nanostructured zinc oxide and an electrolyte composed of iodine plus (1) pure 1-propyl-3-methyl imidazolium iodide (PMII) and (2) a blend of PMII with low-viscosity ionic liquids were employed to construct the devices. Without further additives, the fabricated devices exhibit remarkable short-circuit photocurrents and efficiencies under AM1.5 simulated sunlight (up to 10.6 mA cm−2, 2.9% efficiency, 1 sun, active area = 0.64 cm2) due to the high surface area of the ZnO film and the high absorptivity of the D149 dye. Impedance spectroscopy is used to characterize the devices. It is found that the addition of the low-viscosity ionic-liquid improves the transport features (leading to a better photocurrent) but it does not alter the recombination rate. The robustness of the dye­oxide interaction is tested by applying continuous illumination with a Xenon-lamp. It is observed that the photocurrent is reduced at a slow rate due to desorption of the D149 sensitizer in the presence of the ionic liquid. Exploration of alternative ionic-liquid compositions or modification of the ZnO surface is therefore required to make stable devices based on ZnO and fully organic dyes.


Assuntos
Corantes/química , Indóis/química , Líquidos Iônicos/química , Energia Solar , Óxido de Zinco/química , Eletrólitos/química , Nanoestruturas/química
6.
Proc Natl Acad Sci U S A ; 104(47): 18451-5, 2007 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-18003918

RESUMO

Understanding the molecular mechanism of hemoglobin cooperativity remains an enduring challenge. Protein forces that control ligand affinity are not directly accessible by experiment. We demonstrate that computational quantum mechanics/molecular mechanics methods can provide reasonable values of ligand binding energies in Hb, and of their dependence on allostery. About 40% of the binding energy differences between the relaxed state and tense state quaternary structures result from strain induced in the heme and its ligands, especially in one of the pyrrole rings. The proximal histidine also contributes significantly, in particular, in the alpha-chains. The remaining energy difference resides in protein contacts, involving residues responsible for locking the quaternary changes. In the alpha-chains, the most important contacts involve the FG corner, at the "hinge" region of the alpha(1)beta(2) quaternary interface. The energy differences are spread more evenly among the beta-chain residues, suggesting greater flexibility for the beta- than for the alpha-chains along the quaternary transition. Despite this chain differentiation, the chains contribute equally to the relaxed substitute state energy difference. Thus, nature has evolved a symmetric response to the quaternary structure change, which is a requirement for maximum cooperativity, via different mechanisms for the two kinds of chains.


Assuntos
Hemoglobinas/química , Hemoglobinas/metabolismo , Regulação Alostérica , Monóxido de Carbono/química , Heme/química , Heme/metabolismo , Ferro/química , Modelos Moleculares , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína
7.
Inorg Chem ; 48(11): 4798-805, 2009 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-19364094

RESUMO

The local coordination of Fe(3+) spin probes in trigonal LiAl(y)Co(1-y)O(2) was studied using high-frequency electron paramagnetic resonance spectroscopy. This technique allows the determination of Fe(3+) ions in respect to axial and rhombic zero-field splitting parameters (ZFS). After the progressive replacement of Co by Al, the axial D parameter of Fe(3+) increases from +0.0548 to +0.2802 cm(-1). On the same order, the rhombic E parameter decreases. Structural information about the Fe(3+) site in layered LiAl(y)Co(1-y)O(2) oxides was based on modeling of the magnitude of the ZFS parameters by means of the Newman superposition model. It was found that the first metal coordination sphere including Co(3+) and Al(3+) ions gave rise to differentiation of the Fe(3+) dopants in respect to local trigonal and rhombic distortion. The maximum trigonal distortion for the FeO(6) octahedron was achieved when Fe(3+) spin probes were surrounded by Al only, while the Co environment yields a rhombic distortion of the FeO(6) octahedron.

8.
Sci Rep ; 9(1): 7595, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31110192

RESUMO

Aiming for the introduction of stability requirements in nanofluids processing, an interface-based three-step method is proposed in this work. It is theory-based design framework for nanofluids that aims for a minimum tension at the solid-liquid interface by adjusting the polar and dispersive components of the base fluid to meet those of disperse nanomaterial. The method was successfully tested in the preparation of aqueous nanofluids containing single-walled carbon nanotubes that resulted to be stable and to provide good thermal properties, i.e. thermal conductivity increases by 79.5% and isobaric specific heat by 8.6% for a 0.087 vol.% load of nanotubes at 70 °C. Besides, a system for these nanofluids was modelled. It was found to be thermodynamically consistent and computationally efficient, providing consistent response to changes in the state variable temperature in a classical Molecular Dynamics environment. From an analysis of the spatial components of the heat flux autocorrelation function, using the equilibrium approach, it was possible to elucidate that heat conduction through the host fluid is enhanced by phonon propagation along nanotubes longitudinal axes. From an analysis of the structural features described by radial distribution functions, it was concluded that additional heat storage arises from the hydrophobic effect.

9.
Vet Parasitol ; 150(1-2): 39-45, 2007 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-17931783

RESUMO

The aim of this study was to investigate the participation of Neospora caninum and Toxoplasma gondii in abortion cases of Peruvian llamas and alpacas. Fifteen aborted foetuses were recovered from two main rearing areas of camelids in Peru (Central or South Andean region). Foetal histopathology was used to detect the presence of protozoal-associated lesions in target organs. N. caninum and T. gondii infections were confirmed by immunohistochemistry (IHC) combined with PCR and by PCR alone, respectively. The influence of the species (llama and alpaca), foetal age (first, second and third gestational periods) and geographical location (Central or South Andean region) of the foetuses was also studied. Thirteen of the samples (26%, 13/50) showed lesions suggestive of protozoal infection. N. caninum infection was detected by either IHC or specific PCR in 14 out of 50 foetuses (28%), of which 8 also showed protozoal-associated lesions. T. gondii DNA was not detected in any of the foetuses analysed. Protozoal infection was more frequent in the foetuses from the second gestational period (P<0.05, Fisher F-test). No significant association was observed between protozoal infection and species or geographical location (P>0.05, chi2 test). The results of the present study indicate that neosporosis should be included during the differential diagnosis of abortion in llamas and alpacas.


Assuntos
Feto Abortado/parasitologia , Camelídeos Americanos/parasitologia , Coccidiose/veterinária , Neospora , Toxoplasma , Toxoplasmose Animal/parasitologia , Animais , Coccidiose/parasitologia , Feminino , Idade Gestacional , Imuno-Histoquímica , Masculino , Peru , Reação em Cadeia da Polimerase , Gravidez , Complicações Parasitárias na Gravidez/veterinária
10.
Water Sci Technol ; 56(6): 85-94, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17898447

RESUMO

During the past decade the pressure of the whole spectrum of stakeholders has increased considerably leading the consideration of different types of objectives, i.e. economical, technical, legal and environmental, into the process design efforts. Thus, the traditional design approaches should turn into more complex assessment methods including different types of objectives in order to conduct integrated assessments. The objective of this paper is to present and discuss the usefulness of three evaluation tools, based on multicriteria decision analysis, to support the conceptual design of activated sludge systems These support tools consist of: i) preliminary multiobjective optimization, where the most promising options (those located near to the optimum) are compared based on the results of dynamic simulation, ii) identification of strong and weak points for each option by means of classification trees and the subsequent extraction of knowledge-based rules, and iii) evaluation of the trade-offs between a certain evaluation criteria and the overall process performance through the integrated application of mathematical modelling and qualitative knowledge extracted during the design process.


Assuntos
Modelos Teóricos , Esgotos/análise , Eliminação de Resíduos Líquidos/métodos , Técnicas de Apoio para a Decisão
11.
Biochim Biophys Acta ; 1067(1): 64-70, 1991 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-1651114

RESUMO

Glycine transporter from rat brain stem and spinal cord is inactivated by specific sulfhydryl reagents. Modification of lysine residues also promotes a decrease of the transporter activity but in a lesser extent than that promoted by thiol group reagents. Mercurials showed a more marked inhibitory effect than maleimide derivatives. SH groups display a similar reactivity for p-chloromercuribenzenesulfonate (pCMBS) and mersalyl in synaptosomal membrane vesicles and proteoliposomes reconstituted with the solubilized transporter. However, different reactivity is observed with N-ethylmaleimide (MalNEt), the greatest effect being attained in membrane vesicles. The rate of inactivation by pCMBS and MalNEt is pseudo-first-order showing time- and concentration-dependence. pCMBS and MalNEt decrease the Vmax for glycine transport and to a lesser extent act on the apparent Km. Treatment with dithiothreitol (DTT) of the transporter modified by pCMBS results in a complete restoration of transporter activity indicating that the effect exercised by the reagent is specific for cysteine residues on the protein. It is concluded that SH groups are involved in the glycine transporter function and that these critical residues are mostly located in a relatively hydrophilic environment of the protein.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros , Proteínas de Transporte/metabolismo , Cloretos/metabolismo , Glicina/metabolismo , Sódio/metabolismo , Sinaptossomos/metabolismo , 4-Cloromercuriobenzenossulfonato/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Tronco Encefálico/metabolismo , Etilmaleimida/farmacologia , Proteínas da Membrana Plasmática de Transporte de Glicina , Indicadores e Reagentes , Cinética , Masculino , Membranas/metabolismo , Mersalil/farmacologia , Proteolipídeos/metabolismo , Ratos , Ratos Endogâmicos , Compostos de Sulfidrila/metabolismo , Prega Vocal/metabolismo
13.
Aliment Pharmacol Ther ; 14(7): 929-35, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10886050

RESUMO

BACKGROUND: Interferon therapy has been shown to induce lipid abnormalities. AIM: We assessed the effects of interferon-beta on the lipoprotein profile and post-heparin lipase activities in 26 normolipaemic patients with chronic hepatitis C. METHODS: Interferon-beta was administered subcutaneously at doses of 6 x 106 U (units) three times a week, over 6 months, and lipoproteins and post-heparin lipases were measured at baseline and at the end of therapy. RESULTS: Plasma triglycerides increased by 21% due to preferential enrichment in those contained in the very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions. The concentration of cholesterol decreased slightly in the high density lipoprotein (HDL) subfractions. Lipoprotein lipase, but not hepatic lipase activity decreased by a 36%, and this change showed a significant negative correlation with changes in plasma triglycerides. Five patients (19.5%) responded to interferon-beta therapy. The lipoprotein profile was no different between responders and non-responders to therapy. CONCLUSIONS: Interferon-beta treatment in normolipaemic patients with chronic hepatitis C induced moderate disturbances in plasma lipoproteins, associated with inhibition of lipoprotein lipase activity.


Assuntos
Hepatite C Crônica/tratamento farmacológico , Interferon beta/uso terapêutico , Lipídeos/sangue , Lipase Lipoproteica/metabolismo , Lipoproteínas/sangue , Adulto , Feminino , Hepatite C Crônica/metabolismo , Humanos , Interferon beta/farmacologia , Masculino , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Resultado do Tratamento
14.
Brain Res Mol Brain Res ; 15(1-2): 167-70, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1331663

RESUMO

A high-affinity sodium-dependent L-glutamate transporter was expressed in Xenopus oocytes after microinjection of poly(A)+ RNA from primary astrocyte cultures from rat brain cortex. mRNA-induced L-glutamate transport was saturable by substrate and shows kinetic features similar to those found in intact glial cell preparations. L-Glutamate accumulation was prevented by rising the external K+ concentration or by coincubation with L-, D-aspartate or D-glutamate. After fractionation by sucrose density gradient, the mRNA encoding for the expressed L-glutamate transporter from glial cells was found in fractions containing messages of 2.05-2.9 kilobases (kb) in length.


Assuntos
Glicoproteínas/metabolismo , Neuroglia/metabolismo , Oócitos/metabolismo , RNA Mensageiro/biossíntese , Fosfatase Alcalina/metabolismo , Sistema X-AG de Transporte de Aminoácidos , Animais , Células Cultivadas , Glicoproteínas/biossíntese , Cinética , Poli A/metabolismo , Ratos , Ratos Wistar , Xenopus laevis
15.
Life Sci ; 44(23): 1767-75, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2543879

RESUMO

The beta-adrenergic responsiveness of hepatocytes obtained from hypothyroid rats and of a transplantable hepatoma cell line (AS-30D) were studied by measuring the accumulation of cyclic AMP. The potency order for agonists in hepatocytes was: isoproterenol greater than epinephrine much greater than norepinephrine whereas in the hepatoma cells the potency order was: isoproterenol greater than norepinephrine greater than or equal to epinephrine. The effect of isoproterenol was antagonized in hepatocytes by low concentrations of ICI 118551 and only partially by concentrations of atenolol as high as 100 microM. In hepatoma cells the effect of isoproterenol was inhibited by both antagonists with the potency order atenolol greater than ICI 118551. These data indicate that in hepatocytes the effect is mediated by beta 2-adrenoceptors whereas in hepatoma cells it is through beta 1-adrenoceptors. Preincubation of hepatoma cells with isoproterenol or phorbol-myristate-acetate diminished the subsequent beta-adrenergic responsiveness of the cells. Interestingly, when both isoproterenol and phorbol-myristate-acetate were present during the preincubation the beta-adrenergic desensitization observed was bigger than that induced by any of these agents alone.


Assuntos
Isoproterenol/farmacologia , Neoplasias Hepáticas Experimentais/metabolismo , Receptores Adrenérgicos beta/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Adenilil Ciclases/análise , Animais , AMP Cíclico/análise , Epinefrina/farmacologia , Fígado/citologia , Fígado/metabolismo , Norepinefrina/farmacologia , Propanolaminas/farmacologia , Ratos , Células Tumorais Cultivadas
16.
Int J Clin Pharmacol Ther ; 32(10): 567-9, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7834165

RESUMO

Digoxin-like immunoreactive substance (DLIS) has been detected in several patient populations that were not receiving digoxin. We therefore studied the sensitivity of EMIT Convenience Pack Digoxin immunoassay to interference by DLIS in patients with liver failure. Serum digoxin was measured in cirrhotic patients with moderate to severe liver failure (Child-Pugh B or C grade), patients with mild liver disease (chronic hepatitis) and matched control patients without liver disease. Excluded were patients taking or who had ever received any cardiac glycoside in the past. Blood samples were obtained by venipuncture and assayed in duplicate. Twenty-two out of 30 cirrhotic patients (73%) showed false-positive results, vs. one of 6 patients (16.7%) with mild liver disease, and 1 of 10 (10%) controls. The serum DLIS level was negatively correlated with prothrombin activity (r = -0.55, p < 0.00011). Digoxin levels must be interpreted carefully in patients with moderate to severe liver failure.


Assuntos
Digoxina/sangue , Hepatite/sangue , Cirrose Hepática/sangue , Doença Crônica , Técnica de Imunoensaio Enzimático de Multiplicação , Reações Falso-Positivas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos
17.
J Parasitol ; 90(4): 864-6, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15357084

RESUMO

Neospora caninum is a cyst-forming coccidian that mainly affects bovines, although Neospora infection has also been described in other domestic and wild ruminant species. Serum samples from 78 alpacas (Vicugna pacos) and 73 llamas (Lama glama) at a unique dilution of 1:50 tested by indirect fluorescent antibody test (IFAT) were further analyzed serologically by IFAT and Western blot in both ruminant species to avoid cross-reactions with closely related coccidian parasites and to confirm the existence of N. caninum-specific antibodies. IFAT titers ranging between 1:50 and 1:800 were found. When using Western blot, N. caninum tachyzoite-specific immunodominant antigens with apparent molecular weights of 17-18, 34-35, 37, and 60-62 kDa were also recognized, although some sera with 1:50 IFAT titers proved not to have N. caninum-specific antibodies. As expected, higher IFAT titers were associated with higher anti-N. caninum reactivity in Western blot. This report documents for the first time the presence of N. caninum infection in adult alpacas and llamas from Peru.


Assuntos
Anticorpos Antiprotozoários/sangue , Camelídeos Americanos/parasitologia , Coccidiose/veterinária , Neospora/imunologia , Animais , Western Blotting/veterinária , Coccidiose/diagnóstico , Coccidiose/epidemiologia , Coccidiose/imunologia , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Peru/epidemiologia
18.
Med Eng Phys ; 23(9): 623-31, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11755807

RESUMO

This article compares results obtained in previous studies using time-frequency representations (Wigner-Ville, Choi-Williams and Parametric) and the wavelet transform with those obtained with wavelet packet functions to show new findings about their quality in the analysis of ECoG recordings in human intractable epilepsy: data from 21 patients have been analyzed and processed with four types of wavelet functions, including Orthogonal, Biorthogonal and Non-Orthogonal basis. These functions were compared in order to test their quality to represent spikes in the ECoG. The energy based on the wavelet coefficients to different scales was also calculated. The best results were found with the biorthogonal-6.8 wavelet on 5-7 scales, which gave 0.92 sensitivity, but with a high percentage of false positives; this representation was highly correlated with spike events on time and duration. To improve these results we have studied the wavelet packet coefficients energy. We found that reconstruction wavelet packet coefficients at 4 and 9 nodes contain significant information to characterize the spike event. These nodes' reconstruction coefficients were multiplied and this product was highly correlated with spikes events on time and duration. With this procedure we improved the sensitivity up to 0.96 with the same biorthogonal-6.8 wavelet at four levels. With this technique we do not sacrifice computation time: 896 samples are processed at only 0.16 s, so that it is possible to show the spike scattering path on line, because 896 samples (7 s)/16 channels are processed at 3.13 s.


Assuntos
Eletroencefalografia , Epilepsia/fisiopatologia , Processamento de Sinais Assistido por Computador , Lobo Temporal/fisiopatologia , Adulto , Epilepsia/cirurgia , Humanos , Pessoa de Meia-Idade
19.
Health Phys ; 82(6): 847-54, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12046757

RESUMO

For calibration and testing of radioactive aerosol measuring equipment such as continuous air monitors and cascade impactors, and other research applications, it is helpful to have a convenient and relatively safe means of producing radioactive aerosol particles of controlled size and activity. We describe a technique for producing such particles in the micrometer-diameter size range using electrostatic deposition of radon decay products onto otherwise nonradioactive powders of different sizes. An electric field focuses radon decay products (primarily 218Po) onto the surface of a powdered substrate that is then suspended by a technique such as pneumatic dry dispersion. Only a modest-activity commercial 222Rn source (e.g., containing as little as 10(5) Bq of 226Ra) is required, and issues of radioactive cleanup and contamination are minimized due to the short half-lives (26.8 min or less) of the decay products. We report representative results using powders of glass beads, iron oxide, and iron and gold metals in the size range of 0.3 to 30 microm. Yields for the deposited radioactivity per unit concentration of 222Rn gas were of the order of 5 x 10(-7) Bq (214Bi) per milligram substrate per Bq m(-3) of 222Rn for an electrostatic collection time of 30 min.


Assuntos
Radioisótopos/análise , Aerossóis , Partículas alfa , Meia-Vida , Tamanho da Partícula , Polônio/análise , Radiometria , Produtos de Decaimento de Radônio/análise , Eletricidade Estática
20.
JSLS ; 4(1): 23-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10772524

RESUMO

The authors report a case of an asymptomatic 30-year-old female patient with an extensive cystic lesion continuous with the splenic parenchyma. A review of the literature and use of a videolaparoscopic approach to the treatment of these lesions is presented.


Assuntos
Cistos/cirurgia , Laparoscopia , Esplenopatias/cirurgia , Adulto , Feminino , Humanos , Gravação em Vídeo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA