Auxetic effect of natural fiber knitted fabrics

Since they present a negative Poisson's radio, auxetic materials are different from conventional ones. These materials present an unusual behaviour: when stretched (elongated in the longitudinal direction), their cross-section is increased. There are two different ways to obtain auxetic materials: through polymers or through structures. It is possible to affirm that those obtained through fibrous structures are very recent and that few authors have been dedicated to their study. The main objective of this work is to study the effect of the negative Poisson

Mechanical properties of polypropylene/natural fiber composites: comparison with glass fiber

Natural Fiber Composites based on polypropylene have gained increasing interest over the past two decades, both in the scientific and industry communities. In this study, the mechanical properties of polypropylene (PP)/natural fiber composites were studied and compared with those of polypropylene reinforced by glass fiber. Flax and jute woven fabrics have been used. PP/glass fiber composites showed better performance in terms of tensile properties.

Development of auxetic structures from braided composites produced from basalt fiber

In this work, novel auxetic structure has been developed from braided composites produced from basalt fiber. The paper reported the auxetic and tensile behavior of the structures produced from basalt fiber and also compared with structures developed from braided composites having glass fiber as core. The basic design is modified with straight rod to improve the strengthening behavior of structure with structural elements. The Poisson’s ratio of the modified structure are studied. The Poisson’s ratio of the structure made from basalt and glass reinforced BCRs are almost similar but the tensile behavior of basalt based structure is good than glass fiber.

Study on the degradation of natural fiber geotextiles

Current societal challenges increasingly demand the need to seek for efficient and sustainable solutions to daily problems. Construction, as a result of its activity, is one of the main responsible industry for the exploitation of resources and greenhouse gas emissions. In this way, several research works are being undertaken to change some of the current practices. This paper presents the work being done at University of Minho to study de degradation of natural fibers when used as a sustainable solution for soil reinforcement. Jute and sisal fibrous structures (0º/90º) were studied in terms of their degradation over time, when incorporated into soil and when subject to accelerated aging tests in a QUV weathering test equipment. Results show that the process of biodegradation of natural fibers is clearly accelerated by the action of temperature, moisture and solar radiation, explaining further degradation of jute and sisal fibers when exposed to these factors, although more pronounced in jute fabric structures.

Sintomas depressivos no câncer de mama: Inventário de Depressão de Beck - Short Form

OBJETIVOS: Verificar a prevalência de sintomas depressivos em mulheres com câncer de mama e identificar os fatores de risco associados à sua ocorrência. MÉTODOS: Foi realizado um estudo transversal, em que foram entrevistadas 71 mulheres com câncer de mama. Foram empregados dois instrumentos: um questionário para verificar os dados sociodemográficos e clínicos e o Inventário de Depressão de Beck - Short Form (BDI-SF), para avaliação dos sintomas depressivos. Para análise dos dados, utilizaram-se medidas descritivas e o teste de qui-quadrado, que avaliou a associação entre variáveis sociodemográficas e clínicas e os sintomas depressivos. O nível de significância considerado foi de 5%. RESULTADOS: A prevalência de sintomas depressivos foi de 29,6%. Os fatores associados à presença desses sintomas foram o tratamento quimioterápico (p = 0,021), presença de dor (p = 0,018) e limitação do movimento do membro superior (p = 0,010) e pior percepção da saúde (p = 0,018). CONCLUSÃO: Sintomas depressivos são frequentes no câncer de mama, assim a saúde mental das mulheres com esse tipo de câncer deve ser investigada e tratada quando necessário, reduzindo o impacto desses sintomas na vida da mulher.

Ancestry of the Brazilian TP53 c.1010G>A (p.Arg337His, R337H) founder mutation : clues from haplotyping of short tandem repeats on Chromosome 17p

Rare germline mutations in TP53 (17p13.1) cause a highly penetrant predisposition to a specific spectrum of early cancers, defining the Li-Fraumeni Syndrome (LFS). A germline mutation at codon 337 (p.Arg337His, c1010G>A) is found in about 0.3% of the population of Southern Brazil. This mutation is associated with partially penetrant LFS traits and is found in the germline of patients with early cancers of the LFS spectrum unselected for familial his- tory. To characterize the extended haplotypes carrying the mutation, we have genotyped 9 short tandem repeats on chromosome 17p in 12 trios of Brazilian p.Arg337His carriers. Results confirm that all share a common ancestor haplotype of Caucasian/Portuguese-Ibe- ric origin, distant in about 72–84 generations (2000 years assuming a 25 years intergenera- tional distance) and thus pre-dating European migration to Brazil. So far, the founder p. Arg337His haplotype has not been detected outside Brazil, with the exception of two resi- dents of Portugal, one of them of Brazilian origin. On the other hand, increased meiotic recombination in p.Arg337His carriers may account for higher than expected haplotype diversity. Further studies comparing haplotypes in populations of Brazil and of other areas of Portuguese migration are needed to understand the historical context of this mutation in Brazil.

Repeated assessment and practice effects of the written symbol digit modalities test using a short inter-test interval

The Symbol Digit Modalities Test (SDMT) is a widely used instrument to assess information processing speed, attention, visual scanning, and tracking. Considering that repeated evaluations are a common need in neuropsychological assessment routines, we explored test–retest reliability and practice effects of two alternate SDMT forms with a short inter-assessment interval. A total of 123 university students completed the written SDMT version in two different time points separated by a 150-min interval. Half of the participants accomplished the same form in both occasions, while the other half filled different forms. Overall, reasonable test–retest reliabilities were found (r = .70), and the subjects that completed the same form revealed significant practice effects (p < .001, dz = 1.61), which were almost non-existent in those filling different forms. These forms were found to be moderately reliable and to elicit a similar performance across participants, suggesting their utility in repeated cognitive assessments when brief inter-assessment intervals are required.

Enzymatic treatments to improve mechanical properties and surface hydrophobicity of jute fiber membranes

Fiber membranes prepared from jute fragments can be valuable, low cost, and renewable. They have broad application prospects in packing bags, geotextiles, filters, and composite reinforcements. Traditionally, chemical adhesives have been used to improve the properties of jute fiber membranes. A series of new laccase, laccase/mediator systems, and multi-enzyme synergisms were attempted. After the laccase treatment of jute fragments, the mechanical properties and surface hydrophobicity of the produced fiber membranes increased because of the cross-coupling of lignins with ether bonds mediated by laccase. The optimum conditions were a buffer pH of 4.5 and an incubation temperature of 60 °C with 0.92 U/mL laccase for 3 h. Laccase/guaiacol and laccase/alkali lignin treatments resulted in remarkable increases in the mechanical properties; in contrast, the laccase/2,2-azino-bis-(3-ethylthiazoline-6-sulfonate) (ABTS) and laccase/2,6-dimethoxyphenol treatments led to a decrease. The laccase/ guaiacol system was favorable to the surface hydrophobicity of jute fiber membranes. However, the laccase/alkali lignin system had the opposite effect. Xylanase/laccase and cellulase/laccase combined treatments were able to enhance both the mechanical properties and the surface hydrophobicity of jute fiber membranes. Among these, cellulase/laccase treatment performed better; compared to mechanical properties, the surface hydrophobicity of the jute fiber membranes showed only a slight increase after the enzymatic multi-step processes.

Estudo da ligação entre componentes estruturais de GFRP (glass fiber reinforced polymer) e componentes estruturais em betão

Dissertação de mestrado integrado em Engenharia Civil

Short-term follow-up of patients after aneurysmectomy of the left ventricle

OBJECTIVE: Left ventricular aneurysm is a complication of myocardial infarction that can best be treated by reconstructive surgeries that can restore ventricular geometry. We analyzed immediate results in a group of consecutive patients who underwent surgical correction of left ventricular aneurysms. METHODS: From January '90 to August '99, 94 patients - mean age 58.4 (ranging from 36 to 73 years), 65 (69.1%) males and 9 ( 30.8%) females - were operated upon. Pre-operative ejection fraction ranged from 0.22 to 0.58 (mean = 0.52), and the aneurysm was located in the antero-lateral area in 90.4% of the cases. Functional class III and IV (NYHA) was present in 82 (87.2%) patients, and 12 (12.7%) were in functional class I and II. Congestive heart failure was the most frequent cause (77.6%), occurring in isolation in 24.4% or associated with coronary artery diseases in 53.2%. RESULTS: Short-term follow-up showed a 7.4% mortality, and low cardiac output was the main cause of death. Coming off pump was uneventful in 73 patients (77.6%), with a 3.2% mortality and with the use of inotropics in 20 (21.3%). One patient (1%) did not come off the pump. CONCLUSION: Surgical correction was adequate in the immediate follow-up of operated patients, and mortality was higher in patients with higher functional class.

Psychometric properties of the Portuguese version of the Posttraumatic Growth Inventory Short Form among divorced adults

The aim of this study was to develop and validate a Portuguese version of the Short Form of the Posttraumatic Growth Inventory (PTGI-SF). Using an online convenience sample of Portuguese divorced adults (N = 482), we confirmed the oblique five-factor structure of the PTGI-SF by confirmatory factor analysis. The results demonstrated the measurement invariance across divorce initiator status groups. Total score and factors of PTGI-SF showed good internal consistency, with the exception of the New Possibilities factor, which revealed an acceptable reliability. The Portuguese PTGI-SF showed a satisfactory convergent validity. In terms of discriminant validity, posttraumatic growth assessed by the Portuguese PTGI-SF was a distinct factor from posttraumatic psychological adjustment. These preliminary findings suggest the cultural adaptation and also psychometric properties of the present Portuguese PTGI-SF to measure posttraumatic growth after personal crisis.

Imagens, fragmentos, ligações: sobre Short Movies de Gonçalo M. Tavares

O processo criativo de Gonçalo M. Tavares tende a um exercício frequente de economia ou de depuração verbal facilmente conciliável com a sua adesão à densidade e à intensidade do registo fragmentário encarado como nova epistemologia poética. Recorrendo ao conceito de 'frase-imagem' de Rancière com o qual nos propomos ler as 'curta-metragens' de Short Movies, ponderamos neste ensaio certos tipos de operações com as quais o autor produz literariamente experiências visuais e audiovisuais. Neste livro, o exercício sobre a relação entre escrita e imagem supõe um trabalho sobre a palavra que se faz contra a sua habitual função lógica e ordenadora, no sentido não de promover mas de restringir ou pelo menos de desestabilizar a discursividade e a interpretabilidade. Como se se pretendesse operar uma conversão das apetências narrativizadoras dos signos verbais e da sua capacidade para o "telling", nas aptidões ‘monstrativas’ da visualidade fílmica e do seu típico "showing".

Short- and midterm follow-up results of valvuloplasty with balloon catheter for congenital aortic stenosis

OBJECTIVE: To report short and midtem follow-up results of balloon aortic valvuloplasty to treat congenital aortic stenosis. METHODS: Seventy-five patients (median age: 8 years) underwent the procedure through the retrograde femoral or carotid route. RESULTS: The procedure was completed in 74 patients (98.6%). The peak-to-peak systolic gradient dropped from 79.6±27.7 to 22.3±17.8 mmHg (P<0.001), the left ventricular systolic pressure dropped from 164±39.1 to 110±24.8 mmHg (P<0.001), and the left ventricular end diastolic pressure dropped from 13.3±5.5 to 8.5±8.3 mmHg (P< 0.01). Four patients (5.3%) died due to the procedure. Aortic regurgitation (AoR) appeared or worsened in 27/71 (38%) patients, and no immediate surgical intervention was required. A mean follow-up of 50±38 months was obtained in 37 patients. Restenosis and significant AoR were observed in 16.6% of the patients. The estimates for being restenosis-free and for having significant AoR in 90 months were 60% and 50%, respectively. CONCLUSION: Aortic valvuloplasty was considered the initial palliative method of choice in managing congenital aortic stenosis, with satisfactory short- and midterm results.

Fibrinolytic therapy for thrombosis in cardiac valvular prosthesis short and long term results

OBJECTIVE: To assess the short- and long-term results of the use of streptokinase (SK) for the treatment of thromboses in cardiac valvular prostheses. METHODS: Seventeen patients with cardiac prosthetic thrombosis diagnosed by clinical, echocardiographic, and radioscopic findings underwent fibrinolytic treatment with a streptokinase bolus of 250,000 U followed by 100.000 U/hour. Short- and long-term results were assessed by radioscopy and echocardiography. RESULTS: Of the 17 patients, 12 had mechanical double-disk prostheses (4 aortic, 6 mitral, 2 tricuspid), 4 had single-disk prostheses (2 aortic, 1 mitral, and 1 tricuspid), and 1 had a tricuspid bioprosthesis. The success rate was 64.8%, the partial success rate was 17.6%, and the nonsuccess rate was 17.6%. All patients with a double-disk prosthesis responded, completely or partially, to the treatment. None of the patients with a single-disk prosthesis had complete resolution of the thrombosis. The time of streptokinase infusion ranged from 6 to 80 hours (mean of 56 h). The mortality rate due to the use of streptokinase was 5.8% and was secondary to cerebral bleeding. During streptokinase infusion, 3 (17.6%) embolic episodes occurred as follows: 1 cerebral, 1 peripheral, and 1 coronary. The rethrombosis index was 33% in a mean follow-up of 42 months. CONCLUSION: The use of fibrinolytic agents was effective and relatively safe in patients with primary thrombosis of a double-disk prosthesis. A fatal hemorrhagic complication occurred in 1 (5.8%) patient, and embolic complications occurred in 3 (17.6%) patients. In a mean 42-month follow-up, 67% of the patients were free from rethrombosis.

A curious herbal :containing five hundred cuts, of the most useful plants, which are now used in the practice of physick engraved on folio copper plates, after drawings taken from the life /by Elizabeth Blackwell. To which is added a short description of ye plants and their common uses in physick.

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