6 research outputs found
Dislocation nucleation in shocked fcc solids: effects of temperature and preexisting voids
Quantitative behaviors of shock-induced dislocation nucleation are
investigated by means of molecular dynamics simulations on fcc Lennard-Jones
solids: a model Argon. In perfect crystals, it is found that Hugoniot elastic
limit (HEL) is a linearly decreasing function of temperature: from near-zero to
melting temperatures. In a defective crystal with a void, dislocations are
found to nucleate on the void surface. Also HEL drastically decreases to 15
percent of the perfect crystal when a void radius is 3.4 nanometer. The
decrease of HEL becomes larger as the void radius increases, but HEL becomes
insensitive to temperature.Comment: 4 pages. (ver.2) All figures have been revised. Two citations are
newly added. Numerical unit is unified in the context of solid argon. (ver.
3) A minor revision including new reference
Chemokine receptors in advanced breast cancer: differential expression in metastatic disease sites with diagnostic and therapeutic implications
Background: We investigated the expression of CXCR4, CCR7, estrogen receptor (ER), progesterone receptor (PR) and HER2-neu in human metastatic breast cancers to determine whether these biological biomarkers were preferentially expressed in any organ-specific metastases. Materials and methods: CXCR4, CCR7, ER, PR and HER2-neu expression levels were evaluated by immunohistochemical staining using paraffin-embedded tissue sections of metastatic breast cancers (n = 41) obtained by either diagnostic biopsy or surgical resection. Results: The metastatic sites included the following: bone (n = 15), brain (n = 14), lung (n = 6), liver (n = 2), and omental metastases (n = 2). CXCR4 was expressed in 41% of cases, CCR7 expression was demonstrated in 10%, and HER2-neu overexpression was present in 27%. CXCR4 was more likely to be expressed in bone metastases than visceral metastases (67% versus 26%, P = 0.020). Visceral sites demonstrated a lower rate of CXCR4 positivity (33% and 23%, respectively, for lung and brain metastases). Similarly, CCR7 was more likely to be found in bone metastases than visceral sites (27% versus 0%, P = 0.037). Conclusions: These results indicate that CXCR4 can contribute to the homing of breast cancer cells to the bone. This finding might have important clinical implications since patients with metastatic bone disease may achieve the highest benefit from a CXCR4-targeted therapy