Superposition of small shear deformations on large uniaxial extensions for viscoelastic materials

The equation for small amplitude torsional response superposed on a finite axial stretch history is derived for a material modelled by the BKZ constitutive equation. For the case of a uniaxial step stretch history, this equation contains a term generalizing the well known Rivlin result for nonlinear elasticity plus two additional terms. The equation is used to analyse a recent experiment which studies the relation between the period of free torsional oscillations, axial stretch and axial force in a material undergoing stress relaxation. It is shown that a 10% discrepancy which arises when the data is related by Rivlin's formula can be accounted for by the two additional terms associated with the BKZ formulation. Finally, an expression for the complex modulus for forced torsional oscillations is derived.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25639/1/0000189.pd

Long-Term Follow-Up of Cardiac Function and Quality of Life for Patients in NSABP Protocol B-31/NRG Oncology: A Randomized Trial Comparing the Safety and Efficacy of Doxorubicin and Cyclophosphamide (AC) Followed by Paclitaxel With AC Followed by Paclitaxel and Trastuzumab in Patients With Node-Positive Breast Cancer With Tumors Overexpressing Human Epidermal Growth Factor Receptor 2

Purpose Early cardiac toxicity is a risk associated with adjuvant chemotherapy plus trastuzumab. However, objective measures of cardiac function and health-related quality of life are lacking in long-term follow-up of patients who remain cancer free after completion of adjuvant treatment. Patients and Methods Patients in NSABP Protocol B-31 received anthracycline and taxane chemotherapy with or without trastuzumab for adjuvant treatment of node-positive, human epidermal growth factor receptor 2–positive early-stage breast cancer. A long-term follow-up assessment was undertaken for patients who were alive and disease free, which included measurement of left ventricular ejection fraction by multigated acquisition scan along with patient-reported outcomes using the Duke Activity Status Index (DASI), the Medical Outcomes Study questionnaire, and a review of current medications and comorbid conditions. Results At a median follow-up of 8.8 years among eligible participants, five (4.5%) of 110 in the control group and 10 (3.4%) of 297 in the trastuzumab group had a \u3e 10% decline in left ventricular ejection fraction from baseline to a value \u3c 50%. Lower DASI scores correlated with age and use of medications for hypertension, cardiac conditions, diabetes, and hyperlipidemia, but not with whether patients had received trastuzumab. Conclusion In patients without underlying cardiac disease at baseline, the addition of trastuzumab to adjuvant anthracycline and taxane-based chemotherapy does not result in long-term worsening of cardiac function, cardiac symptoms, or health-related quality of life. The DASI questionnaire may provide a simple and useful tool for monitoring patient-reported changes that reflect cardiac function

Ultra high molecular weight polyethylene and its reinforcement with Carbon Nanotubes in Medical Devices

This chapter discusses the advantages and complexities of ultra high molecular weight polyethylene(UHMWPE) when used as a bearing material for total joint arthroplasty (TJA) and total knee arthroplasty(TKA). The UHMWPE internal structure and its mechanical response depend strongly on a diversity offactors that include radiation crosslinking, fiber reinforcement, and the addition of antioxidants such asVitamin E or Vitamin C. All these manufacturing procedures induce morphological changes andsimultaneously alter the mechanical properties of UHMWPE. The importance of UHMWPE on arthroplasty,including the advantages, the limitations and the strategies devised to overcome the knowndrawbacks are discussed in the first section. The following sections revise and discuss thebiocompatibility, the manufacturing processes, the tribological behaviour, the aging by oxidation andirradiation of UHMWPE and UHMWPE-CNT nanocomposites. The last section analyses the viscoelasticbehavior of UHMWPE and its implications on the long-term survival of total joint arthroplasty

Mitotic Rate and Younger Age Are Predictors of Sentinel Lymph Node Positivity: Lessons Learned From the Generation of a Probabilistic Model

Background: Sentinel lymph node (SLN) biopsy allows surgeons to identify patients with subclinical nodal involvement who may benefit from lymphadenectomy and, possibly, adjuvant therapy. Several factors have been variably, and sometimes discordantly, reported to have predictive value for SLN metastasis to best select which patients require SLN biopsy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41402/1/10434_2004_Article_247.pd

Articles de didàctica de la llengua i de la literatura

Resumen del autor en catalánUno de los problemas del aprendizaje de la gramática es la dificultad para establecer los objetivos y determinar los contenidos en diversas etapas educativas. Da la impresión que siempre se enseñan las mismas tareas sin que que vea ningún avance. Este artículo analiza los resultados de una prueba inicial realizada a alumnos de primero de bachillerato. Se estudia la naturaleza de sus conocimientos gramáticales y se sugieren objetivos, contenidos y criterios metodológicos pensados para que el aprendizaje de la gramática tenga sentido y pueda progresar en esta nueva etapa.CataluñaES