Amorphous and ordered states of concentrated hard spheres under oscillatory shear

Hard sphere colloidal particles are a basic model system to study phase transitions, self-assembly and out-equilibrium states. Experimentally it has been shown that oscillatory shearing of a monodisperse hard sphere glass, produces two different crystal orientations; a face centered cubic (FCC) crystal with the close packed direction parallel to shear at high strains and an FCC crystal with the close packed direction perpendicular to shear at low strains. Here, using Brownian dynamics simulations of hard sphere particles, we have examined high volume fraction shear-induced crystals under oscillatory shear as well their glass counterparts at the same volume fraction. While particle displacements under shear in the glass are almost isotropic, the sheared FCC crystal structures oriented parallel to shear, are anisotropic due to the cooperative motion of velocity–vorticity layers of particles sliding over each other. These sliding layers generally result in lower stresses and less overall particle displacements. Additionally, from the two crystal types, the perpendicular crystal exhibits less stresses and displacements at smaller strains, however at larger strains, the sliding layers of the parallel crystal are found to be more efficient in minimizing stresses and displacements, while the perpendicular crystal becomes unstable. The findings of this work suggest that the process of shear-induced ordering for a colloidal glass is facilitated by large out of cage displacements, which allow the system to explore the energy landscape and find the minima in energy, stresses and displacements by configuring particles into a crystal oriented parallel to shear

Aromatase Inhibitor-Associated Tendinopathy and Muscle Tendon Rupture: Report of Three Cases of This Exceedingly Rare Adverse Event

Aromatase inhibitors (AIs) are a commonly used antihormonal therapy in the treatment of breast cancer in postmenopausal women, specifically in the treatment of hormone receptor-positive breast cancer. AI-associated tendinopathy and muscle tendon rupture is exceedingly rare. Until now, only one case with AI-associated severe tendinopathy has been reported in the medical literature, and there are no recorded cases of AI-associated muscle tendon rapture. We report three cases of postmenopausal women with hormone receptor-positive breast cancer, who experienced tendinopathy or muscle tendon rupture under antihormonal treatment with letrozole. All of the three women were in the adjuvant setting, and the treatment of tendinopathy or tendon rupture consisted of AI discontinuation, initiation of corticosteroids, or surgical treatment. Diagnosis was made via MRI. Furthermore, in our cases, there were no signs of underlying systemic disease, there was no abnormal physical activity preceding the complaints, and there was no use of other drugs beside letrozole. AIs are one of the most commonly used drugs in antihormonal therapy for hormone receptor-positive breast cancer. In every case of a female patient with hormone receptor-positive breast cancer under treatment with AIs and arthralgia, an MRI should be performed in order to exclude the presence of tendinopathy or muscle tendon rupture

Start-up shear of concentrated colloidal hard spheres: Stresses, dynamics, and structure

The transient response of model hard sphere glasses is examined during the application of steady rate start-up shear using Brownian Dynamics (BD) simulations, experimental rheology and confocal microscopy. With increasing strain the glass initially exhibits an almost linear elastic stress increase, a stress peak at the yield point and then reaches a constant steady state. The stress overshoot has a non-monotonic dependence with Peclet number, Pe, and volume fraction, {\phi}, determined by the available free volume and a competition between structural relaxation and shear advection. Examination of the structural properties under shear revealed an increasing anisotropic radial distribution function, g(r), mostly in the velocity - gradient (xy) plane, which decreases after the stress peak with considerable anisotropy remaining in the steady-state. Low rates minimally distort the structure, while high rates show distortion with signatures of transient elongation. As a mechanism of storing energy, particles are trapped within a cage distorted more than Brownian relaxation allows, while at larger strains, stresses are relaxed as particles are forced out of the cage due to advection. Even in the steady state, intermediate super diffusion is observed at high rates and is a signature of the continuous breaking and reformation of cages under shear

Tuning colloidal gels by shear

Using a powerful combination of experiments and simulations we demonstrate how the microstructure and its time evolution are linked with mechanical properties in a frustrated, out-of-equilibrium, particle gel under shear. An intermediate volume fraction colloid–polymer gel is used as a model system, allowing quantification of the interplay between interparticle attractions and shear forces. Rheometry, confocal microscopy and Brownian dynamics reveal that high shear rates, fully breaking the structure, lead after shear cessation to more homogeneous and stronger gels, whereas preshear at low rates creates largely heterogeneous weaker gels with reduced elasticity. We find that in comparison, thermal quenching cannot produce structural inhomogeneities under shear. We argue that external shear has strong implications on routes towards metastable equilibrium, and therefore gelation scenarios. Moreover, these results have strong implications for material design and industrial applications, such as mixing, processing and transport protocols coupled to the properties of the final material

European Lung Cancer Working Party Clinical Practice Guidelines Non-small Cell Lung Cancer: II. Unresectable Non-metastatic Stages

The present guidelines on the management of unresectable non-metastatic non-small cell lung cancer (NSCLC) were formulated by the ELCWP in October 2005. They are designed to answer the following eight questions: 1) Is chest irradiation curative for NSCLC? 2) What are the contra-indications (anatomical or functional) to chest irradiation? 3) Does the addition of chemotherapy add an advantage to radiotherapy? 4) Does the addition of radiotherapy add an advantage to chemotherapy? 5) Is irradiation as effective as surgery for marginally resectable stage III? 6) How to best combine chemotherapy with radiotherapy: sequentially, concomitantly, as consolidation, as induction, as radiosensitiser? 7) In case of too advanced locoregional disease, is there a role for consolidation (salvage) local treatment (surgery or radiotherapy) after induction chemotherapy? 8) In 2005, what are the technical characteristics of an adequate radiotherapy

European Lung Cancer Working Party Clinical Practice Guidelines. Non-Small Cell Lung Cancer: III. Metastatic disease

The present guidelines on the management of advanced non-small cell lung cancer (NS CLC) were formulated by the ELCWP in October 2006. They are designed to answer the following twelve questions: 1) What benefits can be expected from chemotherapy and what are the treatment objectives? 2) What are the active chemotherapeutic drugs for which efficacy has been shown? 3) Which are the most effective platinum-based regimens? 4) Which is the indicated dosage of cisplatin? 5) Can carboplatin be substituted for cisplatin? 6) Which is the optimal number of cycles to be administered? 7) Can non-platinum based regimens be substituted for platinum based chemotherapy as first-line treatment? 8) Is there an indication for sequential chemotherapy? 9) What is the efficacy of salvage chemotherapy and which drugs should be used in that indication? 10) What is the place of targeted therapies? 11) What is the place of chemotherapy in the management of a patient with brain metastases? 12) Which specific drugs can be used for the patient with bone metastases