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1.
Conscious Cogn ; 101: 103332, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35453102

RESUMEN

Fluctuating between external conscious processing and mind wandering is inherent to the human condition. Past research showed that in tasks requiring sustained attention, mind wandering episodes in which attention is directed internally constrain conscious processing of external stimuli. Conversely, conscious processing of internal stimuli is enhanced during mind wandering. To investigate this, we developed and administered a visuomotor tracking task in which participants were instructed to track the path of a stimulus on a screen with a mouse while responding to rare targets. Prior to reports of mind wandering we found the following: The P3 event-related potential component for targets, indicative of conscious stimulus processing, was attenuated at electrodes Cz and Pz. Moreover, alpha power, indicative of internal mental states, increased globally. Theta power increased along the centroparietal area, and beta decreased along right frontal and right centroparietal areas. Interestingly, trait mind wandering was positively correlated with delta power and gamma power, but negatively correlated with the theta-beta ratio. These results demonstrate that mind wandering is characterized by distinct neural signatures at both a state and trait level.


Asunto(s)
Atención , Estado de Conciencia , Electroencefalografía , Humanos
2.
Fish Shellfish Immunol ; 106: 1067-1077, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32956807

RESUMEN

As a consequence of global warming, extreme events, such as marine heatwaves (MHW), have been increasing in frequency and intensity with negative effects on aquatic organisms. This innovative study evaluated for the first time, the immunological and physiological response of the estuarine edible bivalve Scrobicularia plana to different heatwaves, with distinct duration and recovery periods. So, extensive immune (total haemocyte count - THC, haemocyte viability, phagocytosis rate, respiratory oxidative burst of haemocytes, total protein, protease activity, nitric oxide and bactericidal activity of plasma) and oxidative stress (lipid peroxidation - LPO, superoxide dismutase - SOD, catalase - CAT and glutathione-S-Transferase - GST) analyses were performed in an experimental study that tested the impact of heatwaves during 25 days. The survival and condition of S. plana were not affected by the exposure to the extreme events. However, our data suggested that longer heatwaves with shorter recovery periods can be more challenging for the species, since THC and phagocytic activity were most affected under the temperature increase conditions. Regarding the oxidative status, the species increased its SOD activity while MDA production slightly declined to the increase of temperature, protecting the organism from cellular damage. These results indicate that S. plana has a great capacity to adapt to environmental temperature changes, however, the expected higher frequency/duration of heatwaves with climate change trends can cause some debility of the species face to other stressors, which can compromise its success in the future.


Asunto(s)
Bivalvos/inmunología , Bivalvos/metabolismo , Calor/efectos adversos , Estrés Oxidativo , Animales , Recuento de Células Sanguíneas , Catalasa/metabolismo , Glutatión Transferasa/metabolismo , Hemocitos , Peroxidación de Lípido , Malondialdehído/metabolismo , Fagocitosis , Superóxido Dismutasa/metabolismo
3.
Appl Psychophysiol Biofeedback ; 42(4): 335-346, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28866813

RESUMEN

The ability to regulate our own physiological arousal when dealing with the emotional expression of our partner is crucial for satisfactory and stable intimate relationships. In previous physiological studies of marital interactions, researchers have found greater levels of psychophysiological arousal for members of the couple in conflictual interactions in comparison with positive interactions. Past researchers have established that intense and prolonged autonomic and neuroendocrine arousal during marital conflict can have negative consequences for mental and physical health. In this study we examined the physiological reactivity, as measured by skin conductance level, heart rate and cortisol levels, from both partners during a couple's interaction task consisting of a structured conversation about positive and negative aspects of their relationship. Participants were thirty-two heterosexual couples (N = 64) in a committed monogamous relationship with a minimum duration of one year. We found higher heart rate and cortisol levels during negative interaction condition when compared with the positive condition. Skin conductance was higher in the positive interaction condition, when compared with the negative interaction condition. In addition, we found a significant negative association between heart rate variability and autonomic arousal evoked by the interaction task. The implications of these findings for the effects of marital strain on health as well as for the design of risk-reducing interventions, namely biofeedback are discussed.


Asunto(s)
Nivel de Alerta/fisiología , Sistema Nervioso Autónomo/fisiología , Conflicto Psicológico , Respuesta Galvánica de la Piel/fisiología , Frecuencia Cardíaca/fisiología , Hidrocortisona/metabolismo , Relaciones Interpersonales , Esposos , Adulto , Femenino , Humanos , Masculino
4.
Eur J Neurosci ; 44(6): 2334-9, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27421820

RESUMEN

Neuroplasticity - the capacity of the brain to change as a response to internal and external pressures - has been studied from a number of different perspectives. Perhaps one of the most powerful models is the study of populations that have been congenitally deprived of a sense. It has been shown that the right Auditory Cortex (AC) of congenitally deaf humans is neuroplastically modified in order to represent visual properties of a stimulus. One unresolved question is how this visual information is routed to the AC of congenitally deaf individuals. Here, we performed volumetric analysis of subcortical auditory and visual brains regions - namely the thalamus (along with three thalamic nuclei: the pulvinar, the lateral geniculate nucleus and the medial geniculate nucleus), and the inferior and superior colliculi - in deaf and hearing participants in order to identify which structures may be responsible for relaying visual information toward the altered AC. Because there is a hemispheric asymmetry in the neuroplastic changes observed in the AC of the congenitally deaf, we reasoned that subcortical structures that also showed a similar asymmetry in their total volume could have been enlisted in the effort of relaying visual information to the neuroplastically altered right AC. We show that for deaf, but not for hearing individuals, the right thalamus, right lateral geniculate nucleus and right inferior colliculus are larger than their left counterparts. These results suggest that these subcortical structures may be responsible for rerouting visual information to the AC in congenital deafness.


Asunto(s)
Corteza Auditiva/fisiopatología , Mapeo Encefálico , Sordera/congénito , Pérdida Auditiva Sensorineural/congénito , Humanos , Colículos Superiores/fisiopatología , Tálamo/fisiopatología , Corteza Visual/fisiopatología , Adulto Joven
5.
Psychol Med ; 43(3): 603-18, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22781212

RESUMEN

BACKGROUND: Schizophrenia is characterized by deficits in emotional prosody (EP) perception. However, it is not clear which stages of processing prosody are abnormal and whether the presence of semantic content contributes to the abnormality. This study aimed to examine event-related potential (ERP) correlates of EP processing in 15 chronic schizophrenia individuals and 15 healthy controls. METHOD: A total of 114 sentences with neutral semantic content [sentences with semantic content (SSC) condition] were generated by a female speaker (38 with happy, 38 with angry, and 38 with neutral intonation). The same sentences were synthesized and presented in the 'pure prosody' sentences (PPS) condition where semantic content was unintelligible. RESULTS: Group differences were observed for N100 and P200 amplitude: patients were characterized by more negative N100 for SSC, and more positive P200 for angry and happy SSC and happy PPS. Correlations were found between delusions and P200 amplitude for happy SSC and PPS. Higher error rates in the recognition of EP were also observed in schizophrenia: higher error rates in neutral SSC were associated with reduced N100, and higher error rates in angry SSC were associated with reduced P200. CONCLUSIONS: These results indicate that abnormalities in prosody processing occur at the three stages of EP processing, and are enhanced in SSC. Correlations between P200 amplitude for happy prosody and delusions suggest a role that abnormalities in the processing of emotionally salient acoustic cues may play in schizophrenia symptomatology. Correlations between ERP and behavioral data point to a relationship between early sensory abnormalities and prosody recognition in schizophrenia.


Asunto(s)
Encéfalo/fisiopatología , Emociones/fisiología , Potenciales Evocados Auditivos/fisiología , Esquizofrenia/fisiopatología , Psicología del Esquizofrénico , Percepción del Habla/fisiología , Estimulación Acústica/métodos , Adulto , Estudios de Casos y Controles , Señales (Psicología) , Deluciones/fisiopatología , Electroencefalografía/estadística & datos numéricos , Femenino , Lateralidad Funcional , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Percepción de la Altura Tonal/fisiología , Escalas de Valoración Psiquiátrica , Psicopatología , Tiempo de Reacción/fisiología , Semántica
6.
J Bras Pneumol ; 47(5): e20210157, 2021.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-34669834

RESUMEN

OBJECTIVE: To determine the prevalence of recurrent wheezing (RW) in preterm infants who received prophylaxis against severe infection with respiratory syncytial virus (RSV) and to identify genetic susceptibility (atopy or asthma) and risk factors for RW. METHODS: This was a cross-sectional study involving preterm infants who received prophylaxis with palivizumab at a referral center in Brazil during the first two years of age. A structured questionnaire was administered in a face-to-face interview with parents or legal guardians. RESULTS: The study included 410 preterm infants (median age = 9 months [0-24 months]). In the sample as a whole, 111 children (27.1%; [95% CI, 22.9-31.5]) had RW. The univariate analysis between the groups with and without RW showed no differences regarding the following variables: sex, ethnicity, maternal level of education, gestational age, birth weight, breastfeeding, number of children in the household, day care center attendance, pets in the household, and smoking caregiver. The prevalence of RW was twice as high among children with bronchopulmonary dysplasia (adjusted OR = 2.08; 95% CI, 1.11-3.89; p = 0.022) and almost five times as high among those with a personal/family history of atopy (adjusted OR = 4.96; 95% CI, 2.62-9.39; p < 0.001) as among those without these conditions. CONCLUSIONS: Preterm infants who received prophylaxis with palivizumab but have a personal/family history of atopy or bronchopulmonary dysplasia are more likely to have RW than do those without these conditions.


Asunto(s)
Ruidos Respiratorios , Infecciones por Virus Sincitial Respiratorio , Antivirales/uso terapéutico , Estudios Transversales , Hospitalización , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Palivizumab/uso terapéutico , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Factores de Riesgo
7.
J Exp Med ; 168(2): 463-74, 1988 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-3261773

RESUMEN

IL-1 is released by activated monocytes and is thought to be a key mediator of the host immune response. The availability of the purified and, more recently, recombinant IL-1 has allowed the characterization of other biological properties of this molecule. Thus, IL-1 is thought to have the same properties as hemopoietic 1, a growth factor that has been shown to act on primitive murine hemopoietic cells. Here we report that rIL-1 acts synergistically with granulocyte/macrophage CSF (GM-CSF) or granulocyte CSF in the stimulation of clonogenic cells from many patients with acute myeloblastic leukemia (AML). Although IL-1 by itself has no effect on AML blasts, it can support colony formation under conditions where there is detectable production of endogenous GM-CSF. IL-1 also promotes the growth of multipotential progenitors from normal human bone marrow cells in the presence of GM-CSF. These observations support the hypothesis that in the hemopoietic system, IL-1 has a selective effect on primitive precursors.


Asunto(s)
Ensayo de Unidades Formadoras de Colonias , Factores Estimulantes de Colonias/farmacología , Células Madre Hematopoyéticas/citología , Interleucina-1/fisiología , Leucemia Mieloide Aguda/patología , Proteínas Recombinantes/farmacología , Células Tumorales Cultivadas/citología , Ensayo de Tumor de Célula Madre , Células de la Médula Ósea , División Celular/efectos de los fármacos , Células Cultivadas , Factores Estimulantes de Colonias/inmunología , Sinergismo Farmacológico , Células Madre Hematopoyéticas/efectos de los fármacos , Humanos , Sueros Inmunes , Interleucina-1/genética , Cinética , Hibridación de Ácido Nucleico , Células Tumorales Cultivadas/efectos de los fármacos
8.
J Mycol Med ; 30(2): 100933, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32061515

RESUMEN

Essential oils (EO) are effective natural antimicrobials but are susceptible to oxidation. Microencapsulation improves EO stability, reduces toxicity, and controls release. The aim of this study was preparation, characterization and antidermatophytic activity of free and microencapsulated cinnamon essential oil (MP). MP were prepared by the spray drying method and the success of MP encapsulation was confirmed by UV-vis spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. The antifungal effect of EO and MP was evaluated by the broth microdilution method against Microsporum gypseum and Trichophyton mentagrophytes. The checkerboard method was used to assess synergistic interactions. Fluorescence microscopy and scanning electron microscopy were used to investigate the inhibition of hyphal growth by EO and MP. A cytotoxic assay was performed using the VERO cell line. Microencapsulated cinnamon essential oil was found to be micrometric, with a round, regular structure. The minimum inhibitory concentration of EO was found to be between 125-250µg/mL, while that of MP was 220.5-440.5µg/mL. EO was synergistic with fluconazole while microencapsulated oil was less cytotoxic than EO.


Asunto(s)
Antifúngicos , Cinnamomum zeylanicum/química , Dermatomicosis/tratamiento farmacológico , Composición de Medicamentos , Aceites Volátiles , Animales , Antifúngicos/administración & dosificación , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Química Farmacéutica/métodos , Chlorocebus aethiops , Composición de Medicamentos/métodos , Liberación de Fármacos , Humanos , Hifa/efectos de los fármacos , Hifa/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Microsporum/efectos de los fármacos , Microsporum/crecimiento & desarrollo , Aceites Volátiles/administración & dosificación , Aceites Volátiles/aislamiento & purificación , Aceites Volátiles/farmacología , Aceites de Plantas/administración & dosificación , Aceites de Plantas/aislamiento & purificación , Pruebas de Toxicidad , Trichophyton/efectos de los fármacos , Trichophyton/crecimiento & desarrollo , Células Vero
9.
Mol Cell Biol ; 4(9): 1792-9, 1984 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6092939

RESUMEN

Mutants induced at the adenine phosphoribosyl transferase (aprt) locus by dTTP or dCTP pool imbalances were examined for alterations in genomic DNA sequences. No observable changes were detected by Southern blot analysis of most mutant DNAs, suggesting induction of base pair alterations or other events below our level of detection (approximately 30 base pairs). However, in a few strains (11 from a total collection of 125 mutant cell strains), we were able to localize these events to restriction endonuclease recognition sequences when the mutations resulted in the loss or gain of a particular site. The distribution of lost or gained sites in aprt-deficient mutants induced by the two types of pool imbalances clearly varied, with those occurring in a mutator strain with increased dCTP clustering at one end of the aprt gene. Mutants induced by dTTP also revealed novel events: multiple restriction site modifications in a small region of the aprt gene in one mutant and a small (approximately 50 base pairs) insertion or duplication of DNA sequences. As in previous studies, very few deletion or insertion mutants were detected at the aprt locus. The significance of these findings in terms of the known biochemical and genetic consequences of these pool imbalances is discussed.


Asunto(s)
Adenina Fosforribosiltransferasa/genética , Desoxirribonucleótidos/metabolismo , Genes/efectos de los fármacos , Mutación , Pentosiltransferasa/genética , Timidina/farmacología , Animales , Composición de Base , Secuencia de Bases , Línea Celular , Cricetinae , Cricetulus , Enzimas de Restricción del ADN , Femenino , Hibridación de Ácido Nucleico , Ovario
10.
J. bras. pneumol ; 47(5): e20210157, 2021. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1346399

RESUMEN

ABSTRACT Objective: To determine the prevalence of recurrent wheezing (RW) in preterm infants who received prophylaxis against severe infection with respiratory syncytial virus (RSV) and to identify genetic susceptibility (atopy or asthma) and risk factors for RW. Methods: This was a cross-sectional study involving preterm infants who received prophylaxis with palivizumab at a referral center in Brazil during the first two years of age. A structured questionnaire was administered in a face-to-face interview with parents or legal guardians. Results: The study included 410 preterm infants (median age = 9 months [0-24 months]). In the sample as a whole, 111 children (27.1%; [95% CI, 22.9-31.5]) had RW. The univariate analysis between the groups with and without RW showed no differences regarding the following variables: sex, ethnicity, maternal level of education, gestational age, birth weight, breastfeeding, number of children in the household, day care center attendance, pets in the household, and smoking caregiver. The prevalence of RW was twice as high among children with bronchopulmonary dysplasia (adjusted OR = 2.08; 95% CI, 1.11-3.89; p = 0.022) and almost five times as high among those with a personal/family history of atopy (adjusted OR = 4.96; 95% CI, 2.62-9.39; p < 0.001) as among those without these conditions. Conclusions: Preterm infants who received prophylaxis with palivizumab but have a personal/family history of atopy or bronchopulmonary dysplasia are more likely to have RW than do those without these conditions.


RESUMO Objetivo: Determinar a prevalência de sibilância recorrente (SR) em crianças pré-termo que receberam profilaxia contra infecção grave pelo vírus sincicial respiratório (VSR) e identificar susceptibilidade genética (atopia ou asma) e fatores de risco para SR. Métodos: Estudo transversal envolvendo crianças pré-termo que receberam profilaxia com palivizumabe em um centro de referência no Brasil durante os primeiros dois anos de vida. Um questionário estruturado foi aplicado em entrevista presencial com os pais ou responsáveis. Resultados: O estudo incluiu 410 crianças pré-termo (mediana de idade = 9 meses [0-24 meses]). Na amostra total, 111 crianças (27,1%; IC95%: 22,9-31,5) apresentavam SR. A análise univariada entre os grupos com e sem SR não mostrou diferenças em relação às seguintes variáveis: sexo, etnia, escolaridade materna, idade gestacional, peso ao nascer, aleitamento materno, número de crianças no domicílio, frequência em creche, presença de animais de estimação no domicílio e cuidador tabagista. A prevalência de SR foi duas vezes maior entre crianças com displasia broncopulmonar (OR ajustada = 2,08; IC95%: 1,11-3,89; p = 0,022) e quase cinco vezes maior entre aquelas com história pessoal/familiar de atopia (OR ajustada = 4,96; IC95%: 2,62-9,39; p < 0,001) do que entre aquelas sem essas condições. Conclusões: Crianças pré-termo que receberam profilaxia com palivizumabe, mas apresentam história pessoal/familiar de atopia ou displasia broncopulmonar, têm maior probabilidade de apresentar SR do que aquelas sem essas condições.


Asunto(s)
Humanos , Recién Nacido , Lactante , Ruidos Respiratorios , Infecciones por Virus Sincitial Respiratorio/prevención & control , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Infecciones por Virus Sincitial Respiratorio/epidemiología , Antivirales/uso terapéutico , Recien Nacido Prematuro , Estudios Transversales , Factores de Riesgo , Palivizumab/uso terapéutico , Hospitalización
11.
J Mol Biol ; 167(3): 575-94, 1983 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-6308265

RESUMEN

To determine the types of gene structural alterations causing deficiency of adenine phosphoribosyl transferase (aprt) activity in spontaneous and chemically induced mutations of cultured somatic cells, we analyzed the restriction enzyme cleavage patterns of aprt gene sequences in mutant strains selected from Chinese hamster ovary cells. Patterns of aprt-containing fragments in Southern blots were mostly unchanged in our collection of 280 ethyl methane sulfonate-induced and spontaneous aprt- mutants, suggesting that base-pair changes or other alterations below our limit of resolution on agarose gels (approximately 50 base-pairs) are responsible for the great majority of mutations at the aprt locus. Occasionally, these mutations could be localized when they resulted in the loss or gain of a restriction enzyme site and the generation of new fragments of predictable size. Deletions of aprt-containing sequences were detected in only eight of 119 spontaneous mutants and in only one ethyl methane sulfonate-induced mutant. An insertion of 300 base-pairs near the 5' end of the aprt structural gene was found in one spontaneous aprt- strain. This insertion mutant was stable with a reversion frequency of less than 2 X 10(-7). Several unstable aprt- mutants were detected in our collection, but these had no observable alterations of aprt coding or flanking sequences.


Asunto(s)
Adenina Fosforribosiltransferasa/genética , Alelos , Mapeo Cromosómico , Genes , Mutación/efectos de los fármacos , Pentosiltransferasa/genética , Animales , Secuencia de Bases , Células Cultivadas , Cricetinae , Cricetulus , ADN/genética , Enzimas de Restricción del ADN , Electroforesis en Gel de Agar , Metanosulfonato de Etilo/farmacología , Femenino , Hibridación de Ácido Nucleico , Ovario
12.
Med Phys ; 23(9): 1635-42, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8892261

RESUMEN

The angular and energy distributions of photons scattered by water, muscle tissue, and bone were measured at the Physics Institute of the Universidade Federal do Rio de Janeiro using a Ge-detector and a 241Am source of 59.54 keV radiation. Single and double scattering were investigated on samples up to 16 cm in diameter. The results were compared with theoretical calculations of Rayleigh (elastic) and Compton (inelastic) scattering, assuming a simple model for the scattering geometry. The overall agreement between model and experimental results for soft tissue and water allows quantitative predictions based on a simple equation. Some applications are presented.


Asunto(s)
Fotones , Dispersión de Radiación , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Fenómenos Biofísicos , Biofisica , Huesos/diagnóstico por imagen , Humanos , Modelos Estadísticos , Músculos/diagnóstico por imagen , Fantasmas de Imagen , Interpretación de Imagen Radiográfica Asistida por Computador , Agua
13.
Phys Med Biol ; 48(13): 1907-16, 2003 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-12884924

RESUMEN

The importance of structure form factors in describing elastic scattering in diagnostic radiology was studied through a Monte Carlo code built to reproduce scattering in large water samples. The code, developed by us, considers all relevant interactions, including multiple scattering and interference due to scattering by the liquid structure. Geometrical conditions and energies similar to those found in radiology were used. The secondary to primary radiation ratio using the usual free atom approximation and the structure form factor was obtained and both approaches were compared. Calculations of radiological parameters such as the angular distribution of photons incident on the detector and the fraction of scattered photons stopped by anti-scattering grids were also performed considering mammography, thorax and abdomen radiography conditions. The results have shown that S(beta)/P depends on the experimental set-up, being more important for low momentum transfers and sample sizes for which the multiple scattering is not expected to be significant, as in the case of mammography. It was also verified that large samples increase the probability of multiple scattering, masking the structure peak in S(beta) and making the sample structure important just for relatively thin samples. Considering mammography-like geometry, the maximum of the S(beta)/P distribution considering structure form factors occurs around 15 degrees while the correspondent maximum without considering the structure factors occurs around 10 degrees for any sample thickness. S(beta)/P is almost independent of the irradiation field, with the maximum remaining at 15 degrees and 10 degrees for the SFF and FAFF, respectively. The cases studied in this paper stress some conditions in which it is mandatory to use SFF, but since it requires no further significant efforts, the SFF approach is recommended as a standard procedure when describing the elastic scattering process in radiology.


Asunto(s)
Diagnóstico por Imagen/métodos , Dispersión de Radiación , Mamografía/métodos , Método de Montecarlo , Fotones , Programas Informáticos , Agua , Rayos X
14.
Appl Radiat Isot ; 53(4-5): 717-24, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11003511

RESUMEN

At low angles the scattering of X-rays in the diagnostic energy range (low-momentum transfer), it is probable that the scattering interaction will be coherent. This coherence gives rise to interference effects resulting in X-ray diffraction patterns that are characteristic of the scattering material. The usefulness of coherent scattering is not limited to crystallography. It can provide information about biological material as well. The interatomic and intermolecular co-operative effects which modify the free-atom coherent scattering process are well known for highly ordered structures such as crystalline materials but are important for amorphous solids and liquids where short-range ordering occurs. X-ray diffraction using synchrotron radiation has became a well established technique. This work introduces a non-destructive synchrotron radiation X-ray diffraction imaging technique. The feasibility of the X-ray diffraction computed microtomography using synchrotron radiation has been investigated. This research was carried out at the X-ray diffraction beam line of the National Synchrotron Light Laboratory supported by the National Council for Scientific and Technological Development (LNLS/CNPq) in Brazil. These experimental patterns were carried out with a 500 microm slit in front of the detector and an 11.101 keV beam (lambda = 1.117 A) monochromatic beam from the double crystal monochromator. The diffracted beam was detected by a fast scintillation detector (10(6) counts s(-1)) designed specifically to meet the needs of high quality X-ray diffraction and synchrotron radiation experiments. The data were recorded at rates of one second per degree of 2theta (angular steps equal to 0.05 +/- 0.01 degrees) and registered by a multichannel analyzer. These experimental data could be used to evaluate the scattering properties of different tissue-substitute (water, lucite, nylon, plastic and polystyrene) and bone-substitute (hydroxyapatite and aluminum) materials. The data are in good agreement with those obtained by other authors, indicating the feasibility of the imaging technique.


Asunto(s)
Materiales Biomédicos y Dentales , Sustitutos de Huesos , Tomografía Computarizada por Rayos X/métodos , Difracción de Rayos X/métodos , Aluminio , Durapatita , Nylons , Plásticos , Polimetil Metacrilato , Poliestirenos , Sincrotrones , Agua
15.
Acta Med Port ; 14(1): 83-8, 2001.
Artículo en Portugués | MEDLINE | ID: mdl-11321984

RESUMEN

Retrospective analysis of six cases of caudal regression syndrome, classified in accordance with vertebral envolvement. The degree of vertebral agenesis, morphology and topography of the conus medularis, neurologic implications (motor, sensitive and autonomous) and associated malformations, of particular importance in some situations of little significant vertebral agenesis are analyzed. Associations with eventual predisponent factors are sought.


Asunto(s)
Plexo Lumbosacro/anomalías , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Estudios Retrospectivos , Síndrome
17.
J Clin Psychol ; 43(2): 237-45, 1987 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3571503

RESUMEN

This article presents a study of the effects of tachistoscopic presentation of affective words on subjects' conceptualizations, intentions, and responses to a simulated client. The participants, 36 counseling students, were assigned randomly to one of the following treatments: subliminal presentation of negative emotional concepts; subliminal presentation of positive emotional concepts; supraliminal presentation of positive emotional concepts. After the tachistoscopic presentations, all subjects were exposed to a simulated client, whom they were asked to evaluate, respond to, and report the cognitive intentions that guided their responses. Significant effects were found in the subliminal presentation of positive emotional concepts on subjects' conceptualizations, intentions, and responses. Some significant effects also were found for the supraliminal presentation, but only for the client evaluation measure.


Asunto(s)
Psicoterapia , Estimulación Subliminal , Adulto , Emociones , Femenino , Humanos , Masculino , Inconsciente en Psicología , Percepción Visual
18.
J Clin Psychol ; 55(10): 1179-91, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11045770

RESUMEN

There has been an increased interest in the study of language processes in psychotherapy. More recently, research and theoretical formulations of the therapeutic process suggested that we must move from the microscopic study of verbal modes to a macroscopic approach in which these modes are organized into narratives. Narratives are conceived, in this perspective, as the basic instruments for meaning making. In this article the research on narrative processes in psychotherapy is reviewed and discussed in terms of its implications for the theory and practice of cognitive narrative psychotherapy. Additionally some of the main data coming from research projects on cognitive narrative psychotherapy are presented.


Asunto(s)
Terapia Cognitivo-Conductual , Humanos , Lenguaje , Conducta Verbal
19.
Somatic Cell Genet ; 8(4): 423-32, 1982 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7123450

RESUMEN

Thy- mutants, in addition to being resistant to arabinosyl cytosine (arcC), show cross-resistance to 5-fluorouracil (5FU). When Chinese hamster ovary (CHO) cells were exposed to a selection system using both araC and 5FU, the resistant clones isolated were identical to thy- mutants by the following criteria: (1) all were auxotrophic for thymidine with a high reversion frequency to thymidine prototrophy; (2) those tested had a high level of dCTP relative to wild-type cells, while dTTP and dATP levels were unaffected, and (3) all tested had a 7- to 50-fold higher rate of spontaneous mutation than the wild-type strain for at least one independent genetic marker. Although spontaneous thy- mutants were rare, the frequencies of thy- mutants in untreated and mutagenized cultures are consistent with the conclusion that the thy- phenotype is the consequence of a single mutation in CHO cells.


Asunto(s)
Separación Celular/métodos , Mutación , Timidina/genética , Animales , Línea Celular , Cricetinae , Cricetulus , Citarabina/farmacología , Desoxirribonucleótidos/metabolismo , Resistencia a Medicamentos , Femenino , Fluorouracilo/farmacología , Ovario
20.
Blood ; 72(2): 823-6, 1988 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3042049

RESUMEN

The effects of recombinant interleukin-6 (IL-6) on the proliferation of blast precursors present in the peripheral blood of patients with acute myeloblastic leukemia (AML) was investigated. IL-6 had little effect by itself; however, it synergized with granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) in the stimulation of AML blast colony formation. Responsiveness of blast progenitors to IL-6 was heterogeneous. On normal bone marrow cells the same synergy was observed on granulocyte and monocyte precursors (GM-CFC), while there was no significant effect on erythroid and multipotential precursors.


Asunto(s)
Interleucinas/farmacología , Leucemia Mieloide Aguda/patología , División Celular/efectos de los fármacos , Factores Estimulantes de Colonias/farmacología , Sinergismo Farmacológico , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Sustancias de Crecimiento/farmacología , Humanos , Interleucina-3/farmacología , Interleucina-6
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