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1.
Heliyon ; 7(3): e06482, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33817368

RESUMO

An experimental study of the ultrasonic compression moulding (UCM) to manufacture biobased composites made of semicrystalline starch powders and softwood fibres is described. The main objective was to assess the potential of using this fast and economical processing technique to elaborate a 100% biobased composite which might substitute more usual polymer materials for structural applications. The starch powder was chosen as raw material for the matrix while the reinforcement was made of softwood fibres. Tablets made of starch only and composite beams were processed under different conditions and characterised by several techniques. Three types of starch powders and two types of fibres were used as raw materials. A morphological and crystalline analysis was carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The native semicrystalline structure of starch granules was not totally preserved so as to obtain a homogeneous material. Diametral compression tests on tablets were performed to improve the processing route and obtain the materials with the best properties. Bending tests were used on composite beams to quantify the mechanical properties and study the effects of the processing parameters. The optimum processing parameters were defined and allowed obtaining a matrix for which the flexural strength reached 21 MPa. Mechanical properties were improved when fibres were added into the matrix: three-points bending tests showed a Young's modulus of 6 GPa, a flexural strength of 75 MPa and a flexural strain at break of 6% for a bulk density of 1.25. Considering these results, UCM appears to be a promising process to design a 100% biobased composite with mechanical properties comparable to those of classical discontinuous fibre composites.

2.
Clin Genitourin Cancer ; 13(1): 71-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24993933

RESUMO

BACKGROUND: The differential impact of the number of prior lines of therapy and the setting of prior therapy (perioperative or metastatic) is unclear in advanced urothelial carcinoma. PATIENTS AND METHODS: Ten phase II trials of salvage chemotherapy, biologic agent therapy, or both, enrolling 731 patients, were available. Data on the number of prior lines of therapy and the setting of prior therapy were required in addition to known previously recognized prognostic factors: time from prior chemotherapy, hemoglobin level, performance status, and liver metastasis status. Cox proportional hazards regression was used to evaluate the association of the number of prior lines and prior perioperative therapy with overall survival (OS) as the primary clinical endpoint. Trial was a stratification factor. RESULTS: A total of 711 patients were evaluable. The overall median progression-free survival and OS were 2.7 and 6.8 months, respectively. The number of prior lines was 1 in 559 patients (78.6%), 2 in 111 (15.6%), 3 in 29 (4.1%), 4 in 10 (1.4%), and 5 in 2 (0.3%). Prior perioperative chemotherapy was given to 277 (39.1%) and chemotherapy for metastatic disease to 454 (64.1%). The number of prior lines was not independently associated with OS (hazard ratio, 0.99; 95% CI, 0.86-1.14). Prior perioperative chemotherapy was a favorable factor for OS on univariate but not multivariate analysis. CONCLUSION: The number of prior lines of therapy and prior perioperative chemotherapy were not independently prognostic in patients with urothelial carcinoma receiving salvage therapy. Adoption of these data in salvage therapy trials should enhance accrual, the interpretability of results, and drug development.


Assuntos
Tratamento Farmacológico/métodos , Terapia de Salvação/métodos , Neoplasias Urológicas/tratamento farmacológico , Neoplasias Urológicas/mortalidade , Idoso , Ensaios Clínicos Fase II como Assunto , Humanos , Pessoa de Meia-Idade , Assistência Perioperatória , Estudos Prospectivos , Análise de Regressão , Análise de Sobrevida , Resultado do Tratamento
3.
Ann Oncol ; 24(9): 2414-21, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23897706

RESUMO

BACKGROUND: Variations in urothelial carcinoma (UC) response to platinum chemotherapy are common and frequently attributed to genetic and epigenetic variations of somatic DNA. We hypothesized that variations in germline DNA may contribute to UC chemosensitivity. PATIENTS AND METHODS: DNA from 210 UC patients treated with platinum-based chemotherapy was genotyped for 80 single nucleotide polymorphisms (SNPs). Logistic regression was used to examine the association between SNPs and response, and a multivariable predictive model was created. Significant SNPs were combined to form a SNP score predicting response. Eleven UC cell lines were genotyped as validation. RESULTS: Six SNPs were significantly associated with 101 complete or partial responses (48%). Four SNPs retained independence association and were incorporated into a response prediction model. Each additional risk allele was associated with a nearly 50% decrease in odds of response [odds ratio (OR) = 0.51, 95% confidence interval 0.39-0.65, P = 1.05 × 10(-7)). The bootstrap-adjusted area under the curves of this model was greater than clinical prognostic factors alone (0.78 versus 0.64). The SNP score showed a positive trend with chemosensitivity in cell lines (P = 0.115). CONCLUSIONS: Genetic variants associated with response of UC to platinum-based therapy were identified in germline DNA. A model using these genetic variants may predict response to chemotherapy better than clinical factors alone.


Assuntos
Carboplatina/uso terapêutico , Cisplatino/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Urológicas/tratamento farmacológico , Neoplasias Urológicas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/genética , Feminino , Estudos de Associação Genética , Variação Genética , Genótipo , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Resultado do Tratamento , Neoplasias Urológicas/mortalidade , Urotélio/patologia
4.
Arq. bras. med. vet. zootec ; 57(6): 805-810, dez. 2005. tab
Artigo em Português | LILACS | ID: lil-436503

RESUMO

Dados de 435 animais de uma população F2 de suínos foram utilizados para avaliar a possibilidade de redução da dimensão do espaço multivariado, por meio da técnica de componentes principais. Foram avaliadas as seguintes características de desempenho: tamanho da leitegada ao nascer (TLN), tamanho da leitegada à desmama (TLD), número de tetos (NT), pesos ao nascer (PN), aos 21 (P21), aos 42 (P42), aos 63 (P63) e aos 77 (P77) dias de idade e ganho médio de peso diário (GPD), consumo de ração (CR) e conversão alimentar (CA) dos 77 aos 105 dias de idade. Seis componentes principais, obtidos a partir da matriz de correlação, apresentaram variância inferior a 0,7 (auto valores inferiores a 0,7), o que sugere seis variáveis para descarte, por apresentarem maiores coeficientes, em valor absoluto, a partir do último componente principal. As variáveis descartadas apresentaram correlação linear simples significativa com as demais. Em razão do grande número de variáveis redundantes, 54,5% delas podem ser eliminadas, sendo recomendada a avaliação de apenas TLN, NT, P77, CR e CA, sem que haja perda considerável da informação.


Assuntos
Constituição Corporal/fisiologia , Aumento de Peso/fisiologia , Peso-Idade/fisiologia , Ração Animal/análise , Suínos
5.
Arq. bras. med. vet. zootec ; 55(4): 480-490, Aug. 2003. tab
Artigo em Inglês | LILACS | ID: lil-349710

RESUMO

Growth curves of Nellore cattle were analyzed using body weights measured at ages ranging from 1 day (birth weight) to 733 days. Traits considered were birth weight, 10 to 110 days weight, 102 to 202 days weight, 193 to 293 days weight, 283 to 383 days weight, 376 to 476 days weight, 551 to 651 days weight, and 633 to 733 days weight. Two data samples were created: one with 79,849 records from herds that had missing traits and another with 74,601 from herds with no missing traits. Records preadjusted to a fixed age were analyzed by a multiple trait model (MTM), which included the effects of contemporary group, age of dam class, additive direct, additive maternal, and maternal permanent environment. Analyses were carried out by a Bayesian method for all nine traits. The random regression model (RRM) included the effects of age of animal, contemporary group, age of dam class, additive direct, permanent environment, additive maternal, and maternal permanent environment. Legendre cubic polynomials were used to describe random effects. MTM estimated covariance components and genetic parameters for birth weight and sequential weights and RRM for all ages. Due to the fact that covariance components based on RRM were inflated for herds with missing traits, MTM should be used and converted to covariance functions.


Assuntos
Animais , Bovinos , Crescimento
6.
Arq. bras. med. vet. zootec ; 54(4): 414-423, jul.-ago. 2002. tab, graf
Artigo em Português | LILACS | ID: lil-328418

RESUMO

Para estabelecer a melhor forma de considerar os efeitos fixos dos modelos de regressäo aleatória, avaliou-se a utilizaçäo de funçöes polinomiais na descriçäo de curvas de crescimento e no efeito da idade da vaca sobre pesos corporais de 41.415 bovinos jovens da raça Tabapuä, criados em regime de pasto. A idade da vaca ao parto e o sexo do animal influenciaram os pesos nos primeiros dois anos de vida, e o efeito da idade da mäe sobre o desenvolvimento dos animais mostrou-se dependente da idade dos filhos. Altos coeficientes de determinaçäo (R²>0,98) foram alcançados utilizando-se o efeito da idade da vaca no dia da pesagem do animal (i.e., a idade da vaca ao parto mais a idade do animal no dia de sua pesagem) em polinômios de, no mínimo, segundo grau, e curvas de crescimentos médios, diferenciadas para machos e fêmeas, descritas por meio de polinômios de, no mínimo, terceiro grau


Assuntos
Animais , Masculino , Feminino , Bovinos , Crescimento
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