989 resultados para INTERFACE CHARACTERISTICS
Resumo:
The behavior of stone groundwood / polypropylene injection-molded composites was evaluated with and without coupling agent. Stone groundwood (SGW) is a fibrous material commonly prepared in a high yield process and mainly used for papermaking applications. In this work, the use of SGW fibers was explored as a reinforcing element of polypropylene (PP) composites. The surface charge density of the composite components was evaluated, as well as the fiber’s length and diameter inside the composite material. Two mixing extrusion processes were evaluated, and the use of a kinetic mixer, instead of an internal mixer, resulted in longer mean fiber lengths of the reinforcing fibers. On the other hand, the accessibility of surface hydroxyl groups of stone groundwood fibers was improved by treating the fibers with 5% of sodium hydroxide, resulting in a noticeable increase of the tensile strength of the composites, for a similar percentage of coupling agent. A new parameter called Fiber Tensile Strength Factor is defined and used as a baseline for the comparison of the properties of the different composite materials. Finally the competitiveness of stone groundwood / polypropylene / polypropylene-co-maleic anhydride system, which compared favorably to sized glass-fiber / polypropylene GF/PP and glass-fiber / polypropylene / polypropylene-co-maleic anhydride composite formulations, was quantified by means of the fiber tensile strength factor
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Trata-se de estudo de intenção epistemológica acerca da teoria do alcance de metas de King e suas contribuições para o conhecimento e prática de enfermeiros que atuam no Programa "Saúde da Família" (PSF), Brasil. Aplicou-se o componente Análise, do Método de Análise de Teorias de Meleis na reflexão crítica sobre a teoria, e tomou-se de leituras e reflexões quanto às diretrizes e propostas do PSF para perceber a interface entre os dois paradigmas em estudo. Identificou-se haver coerência entre as duas propostas de abordagem, o que leva as autoras a recomendarem a adoção dos ensinamentos de King na prática do PSF, no sentido da enfermagem obter maiores e melhores resultados de suas ações.
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Monoclonal IgG are commonly observed in various B cell disorders, of which multiple myeloma is the most clinically relevant. In a series of serum samples, we identified by immunofixation 73 monoclonal IgG, including 63 IgG(1), 4 IgG(2), 5 IgG(3), and 1 IgG(4). The light chains were of kappa type in 45 cases, and of lambda type in 28 cases. These monoclonal IgG were further characterized by high resolution two-dimensional polyacrylamide gel electrophoresis (2-DE) in various isoelectric focusing conditions, as well as by 3-DE (2-DE of the proteins extracted from agarose after serum protein agarose electrophoresis). After 2-DE, 38 out of 73 monoclonal gamma chains (52%) were visualized using immobilized pH 3-10 gradients for isoelectric focusing. In 6 cases (8%), gamma chains were only detected using alkaline immobilized pH 6-11 gradients. In 3 cases (4%), 3-DE revealed monoclonal gamma chains hidden by polyclonal gamma chains. Finally, in 26 cases (36%), no monoclonal gamma chains were clearly visualized. Sixty-one monoclonal light chains (84%) were detected using immobilized pH 3-10 gradients, whereas 12 (16%) were not. Monoclonal gamma chains and light chains were highly heterogeneous in terms of pI and M(r). However, a statistically significant correlation (P<0.05) was observed between the position of the monoclonal IgG in agarose gel and the pI of their heavy and light chains (R=0.733, multiple linear regression). Because of the extreme diversity of their heavy and light chains, it appears that a classification of monoclonal IgG based only on their electrophoretic properties is not possible.
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Immature T-ALL is a newly defined subgroup of ALL in which the blasts lack the receptor for sheep erythrocytes (ER) and the usual T-cell markers, but express the 40 kDa pan-T surface antigen recognized by our monoclonal antibody LAU-A1. Patients with immature T-ALL represent 10% of all cases of adult ALL. Leukocyte counts are lower and spleen, liver and lymph node enlargement is less prominent, but mediastinal enlargement is more frequent than in mature (ER-positive) T-ALL. 7 patients with immature T-ALL (median age 42 years, range 13-73) were treated with intensified chemotherapy regimens, and only one 47-year-old female entered a short-lived complete remission. The overall survival of our patients was poor (median 7.5 months, with only one patient surviving at 15 months) and seemed not to be influenced by age. Our study indicates that immature T-ALL can only be accurately identified by the use of monoclonal antibodies recognizing the 40 kDa pan-T antigen, and that immature T-ALL is a separate disease entity typified by a poor prognosis.
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BACKGROUND: Solid-organ transplant recipients are at high risk for the development of herpes zoster. Epidemiologic data in lung transplant recipients are lacking. We determined the incidence and clinical characteristics of herpes zoster, and the risk factors for developing herpes zoster, after lung transplantation. METHODS: We retrospectively reviewed all adult (>18 years old) lung transplants performed at our institution between January 2001 and December 2005. Clinical characteristics of herpes zoster and potential risk factors associated with herpes zoster were assessed. RESULTS: Two hundred thirty-nine lung transplant recipients were included in the analysis. Median time of follow-up was 722 days (range 18 to 1,943 days). Thirty-five episodes of herpes zoster occurred in 29 patients, with a calculated incidence of 55.1 cases per 1,000 person-years of follow-up. The cumulative probability of herpes zoster was 5.8% at 1 year, 18.1% at 3 years and 20.2% at 5 years post-transplant. Only 2 of the 35 (5.7%) patients had disseminated cutaneous infection and none had visceral involvement. Recurrence of herpes zoster was seen in 13.8% of patients. Post-herpetic neuralgia was detected in 20% of cases. Anti-viral prophylaxis, primarily for cytomegalovirus (CMV), was protective against herpes zoster. No significant epidemiologic risk factors associated with herpes zoster could be identified. CONCLUSIONS: Herpes zoster is a common complication after lung transplantation with a peak incidence at between 1 and 4 years post-transplant. Preventive strategies would be beneficial for this population.
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OBJECTIVES: Gender differences in psychotic disorder have been observed in terms of illness onset and course; however, past research has been limited by inconsistencies between studies and the lack of epidemiological representative of samples assessed. Thus, the aim of this study was to elucidate gender differences in a treated epidemiological sample of patients with first episode psychosis (FEP). METHODS: A medical file audit was used to collect data on premorbid, entry, treatment and 18-month outcome characteristics of 661 FEP consecutive patients treated at the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne, Australia. RESULTS: Prior to onset of psychosis, females were more likely to have a history of suicide attempts (p=.011) and depression (p=.001). At service entry, females were more likely to have depressive symptoms (p=.007). Conversely, males had marked substance use problems that were evident prior to admission (p<.001) and persisted through treatment (p<.001). At service entry, males also experienced more severe psychopathology (p<.001) and lower levels of functioning (GAF, p=.008; unemployment/not studying p=.004; living with family, p=.003). Treatment non-compliance (p<.001) and frequent hospitalisations (p=.047) were also common for males with FEP. At service discharge males had significantly lower levels of functioning (GAF, p=.008; unemployment/not studying p=.040; living with family, p=.001) compared to females with FEP. CONCLUSIONS: Gender differences are evident in illness course of patients with FEP, particularly with respect to past history of psychopathology and functioning at presentation and at service discharge. Strategies to deal with these gender differences need to be considered in early intervention programs.
Morphological and physiological species-dependent characteristics of the rodent Grueneberg ganglion.
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In the mouse, the Grueneberg ganglion (GG) is an olfactory subsystem implicated both in chemo- and thermo-sensing. It is specifically involved in the recognition of volatile danger cues such as alarm pheromones and structurally-related predator scents. No evidence for these GG sensory functions has been reported yet in other rodent species. In this study, we used a combination of histological and physiological techniques to verify the presence of a GG and investigate its function in the rat, hamster, and gerbil comparing with the mouse. By scanning electron microscopy (SEM) and transmitted electron microscopy (TEM), we found isolated or groups of large GG cells of different shapes that in spite of their gross anatomical similarities, display important structural differences between species. We performed a comparative and morphological study focusing on the conserved olfactory features of these cells. We found fine ciliary processes, mostly wrapped in ensheating glial cells, in variable number of clusters deeply invaginated in the neuronal soma. Interestingly, the glial wrapping, the amount of microtubules and their distribution in the ciliary processes were different between rodents. Using immunohistochemistry, we were able to detect the expression of known GG proteins, such as the membrane guanylyl cyclase G and the cyclic nucleotide-gated channel A3. Both the expression and the subcellular localization of these signaling proteins were found to be species-dependent. Calcium imaging experiments on acute tissue slice preparations from rodent GG demonstrated that the chemo- and thermo-evoked neuronal responses were different between species. Thus, GG neurons from mice and rats displayed both chemo- and thermo-sensing, while hamsters and gerbils showed profound differences in their sensitivities. We suggest that the integrative comparison between the structural morphologies, the sensory properties, and the ethological contexts supports species-dependent GG features prompted by the environmental pressure.
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OBJECTIVES: To determine if adolescent onset systemic juvenile idiopathic arthritis (JIA) and adult onset Still's disease (AOSD) represent the same clinical continuum of disease. METHODS: Retrospective review of available clinical data on all pediatric and adult patients diagnosed with Still's disease within the last 10 years at a university hospital. Assessment of functional outcomes at last visit by clinical evaluation and HAQ or c-HAQ. RESULTS: Nine patients were identified as adolescent onset systemic JIA and were compared with 10 patients with AOSD (onset > 18 years old). No statistically significant differences were found between the two groups in terms of clinical presentation at onset and outcome at follow up. CONCLUSION: Adolescent patients presenting with systemic JIA have a disease onset and course undistinguishable from that of AOSD patients, suggesting that they represent a continuum of a single disease entity.
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Three-dimensional segmented echo planar imaging (3D-EPI) is a promising approach for high-resolution functional magnetic resonance imaging, as it provides an increased signal-to-noise ratio (SNR) at similar temporal resolution to traditional multislice 2D-EPI readouts. Recently, the 3D-EPI technique has become more frequently used and it is important to better understand its implications for fMRI. In this study, the temporal SNR characteristics of 3D-EPI with varying numbers of segments are studied. It is shown that, in humans, the temporal variance increases with the number of segments used to form the EPI acquisition and that for segmented acquisitions, the maximum available temporal SNR is reduced compared to single shot acquisitions. This reduction with increased segmentation is not found in phantom data and thus likely due to physiological processes. When operating in the thermal noise dominated regime, fMRI experiments with a motor task revealed that the 3D variant outperforms the 2D-EPI in terms of temporal SNR and sensitivity to detect activated brain regions. Thus, the theoretical SNR advantage of a segmented 3D-EPI sequence for fMRI only exists in a low SNR situation. However, other advantages of 3D-EPI, such as the application of parallel imaging techniques in two dimensions and the low specific absorption rate requirements, may encourage the use of the 3D-EPI sequence for fMRI in situations with higher SNR.
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Estudo teórico acerca do processo de formação em Enfermagem Psiquiátrica e Saúde Mental, frente às crescentes mudanças no mundo globalizado e seu acelerado processo de modernização científica e tecnológica. Objetiva discutir o fazer pedagógico no ensino da Enfermagem Psiquiátrica e Saúde Mental, e sua interface com os princípios da Reforma Psiquiátrica e das Diretrizes Curriculares Nacionais dos Cursos de Graduação em Enfermagem. Para sua sustentação teórica, adota como referência alguns construtos da Reforma Psiquiátrica e das Diretrizes Curriculares Nacionais do Curso de Graduação em Enfermagem, e sua relação com fatores constituintes do fazer pedagógico na Enfermagem Psiquiátrica e Saúde Mental. Evidencia que não basta apontar questões técnicas relativas a conteúdos e ensino, procedimentos didáticos, métodos e técnicas pedagógicas; é necessário superar desafios e implementar as mudanças, pautando-se numa nova perspectiva, e ousando colocar em questão a natureza do saber e das práticas institucionais psiquiátricas.
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This study analyses gender inequalities in health among elderly people in Catalonia (Spain) by adopting a conceptual framework that globally considers three dimensions of health determinants : socio-economic position, family characteristics and social support. Data came from the 2006 Catalonian Health Survey. For the purposes of this study a sub-sample of people aged 65–85 years with no paid job was selected (1,113 men and 1,484 women). The health outcomes analysed were self-perceived health status, poor mental health status and long-standing limiting illness. Multiple logistic regression models separated by sex were fitted and a hierarchical model was fitted in three steps. Health status among elderly women was poorer than among the men for the three outcomes analysed. Whereas living with disabled people was positively related to the three health outcomes and confidant social support was negatively associated with all of them in both sexes, there were gender differences in other social determinants of health. Our results emphasise the importance of using an integrated approach for the analysis of health inequalities among elderly people, simultaneously considering socio-economic position, family characteristics and social support, as well as different health indicators, in order fully to understand the social determinants of the health status of older men and women.
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Various compositions of synthetic calcium phosphates (CaP) have been proposed and their use has considerably increased over the past decades. Besides differences in physico-chemical properties, resorption and osseointegration, artificial CaP bone graft might differ in their resistance against biofilm formation. We investigated standardised cylinders of 5 different CaP bone grafts (cyclOS, chronOS (both β-TCP (tricalcium phosphate)), dicalcium phosphate (DCP), calcium-deficient hydroxyapatite (CDHA) and α-TCP). Various physico-chemical characterisations e.g., geometrical density, porosity, and specific surface area were investigated. Biofilm formation was carried out in tryptic soy broth (TSB) and human serum (SE) using Staphylococcus aureus (ATCC 29213) and S. epidermidis RP62A (ATCC 35984). The amount of biofilm was analysed by an established protocol using sonication and microcalorimetry. Physico-chemical characterisation showed marked differences concerning macro- and micropore size, specific surface area and porosity accessible to bacteria between the 5 scaffolds. Biofilm formation was found on all scaffolds and was comparable for α-TCP, chronOS, CDHA and DCP at corresponding time points when the scaffolds were incubated with the same germ and/or growth media, but much lower for cyclOS. This is peculiar because cyclOS had an intermediate porosity, mean pore size, specific surface area, and porosity accessible to bacteria. Our results suggest that biofilm formation is not influenced by a single physico-chemical parameter alone but is a multi-step process influenced by several factors in parallel. Transfer from in vitro data to clinical situations is difficult; thus, advocating the use of cyclOS scaffolds over the four other CaP bone grafts in clinical situations with a high risk of infection cannot be clearly supported based on our data.
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The focus of this review is to highlight the need for improved communication between medical and dental professionals in order to deliver more effective care to patients. The need for communication is increasingly required to capitalise on recent advances in the biological sciences and in medicine for the management of patients with chronic diseases. Improvements in longevity have resulted in populations with increasing special oral-care needs, including those who have cancer of the head and neck, those who are immunocompromised due to HIV/AIDS, advanced age, residence in long-term care facilities or the presence of life-long conditions, and those who are receiving long-term prescription medications for chronic conditions (e.g., anti-hypertensives, anticoagulants, immunosuppressants, antidepressants). These medications can cause adverse reactions in the oral cavity, such as xerostomia and ulceration. Patients with xerostomia are at increased risk of tooth decay, periodontal disease and infection. The ideal management of such individuals should involve the collaborative efforts of physicians, nurses, dentists and dental hygienists, thus optimising treatment and minimising secondary complications deriving from the oral cavity.
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The mucosa-associated lymphoid tissue protein-1 (MALT1, also known as paracaspase) is a protease whose activity is essential for the activation of lymphocytes and the growth of cells derived from human diffuse large B-cell lymphomas of the activated B-cell subtype (ABC DLBCL). Crystallographic approaches have shown that MALT1 can form dimers via its protease domain, but why dimerization is relevant for the biological activity of MALT1 remains largely unknown. Using a molecular modeling approach, we predicted Glu 549 (E549) to be localized within the MALT1 dimer interface and thus potentially relevant. Experimental mutation of this residue into alanine (E549A) led to a complete impairment of MALT1 proteolytic activity. This correlated with an impaired capacity of the mutant to form dimers of the protease domain in vitro, and a reduced capacity to promote NF-κB activation and transcription of the growth-promoting cytokine interleukin-2 in antigen receptor-stimulated lymphocytes. Moreover, this mutant could not rescue the growth of ABC DLBCL cell lines upon MALT1 silencing. Interestingly, the MALT1 mutant E549A was unable to undergo monoubiquitination, which we identified previously as a critical step in MALT1 activation. Collectively, these findings suggest a model in which E549 at the dimerization interface is required for the formation of the enzymatically active, monoubiquitinated form of MALT1.