Coefficient of normal restitution of viscous particles and cooling rate of granular gases

We investigate the cooling rate of a gas of inelastically interacting particles. When we assume velocity dependent coefficients of restitution the material cools down slower than with constant restitution. This behavior might have large influence to clustering and structure formation processes.Comment: 3 figures, Phys. Rev. E (in press

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Interleukin-6 regulates iron-related proteins through c-Jun N-terminal kinase activation in BV2 microglial cell lines

<div><p>Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by the loss of dopaminergic (DA) neurons in the substantia nigra (SN) and subsequent DA depletion in the striatum. Microglia activation and nigral iron accumulation play important roles in the pathogenesis of PD. Activated microglia show increased iron deposits. However, the relationship between microglia activation and iron accumulation remains unclear. In the present study, we aimed to determine how iron levels affect interleukin-6 (IL-6) synthesis, and the effect of IL-6 on cellular iron metabolism in BV2 microglial cells.IL-6 mRNA was up-regulated after FAC treatment for 12 h in BV2 cells. Iron regulatory protein 1 (IRP1) and divalent metal transporter 1 (DMT1) were up-regulated and iron exporter ferroportin 1 (FPN1) was down-regulated in BV2 cells after 24 h of IL-6 treatment. Phosphorylated JNK increased significantly compared to the control after BV2 cells were treated with IL-6 for 1 h. Pretreatment with SP600125 attenuated the up-regulation of IRP1 and DMT1 and down-regulation of FPN1 (compared to IL-6-treated group). These results suggest that iron load could increase IL-6 mRNA expression in BV2 cells. Further, IL-6 likely up-regulates IRP1 and DMT1 expression and down-regulates FPN1 expression in BV2 microglial cells through JNK signaling pathways.</p></div

Phosphorylated JNK/total JNK ratios were increased in IL-6-treated BV2 cells.

<p>A: Western blots to detect phosphorylated JNK and total JNK expression. Ratio of phosphorylated JNK/total JNK increased after IL-6 treatment for 1 h, compared with the control group. B: Statistical analysis. Data are presented as the ratio of P-JNK to total JNK. Each bar represents the mean ± S.E.M of 3 independent experiments (*P < 0.05 compared with the control; n = 3).</p

IL-6 mRNA was up-regulated after FAC treatment in BV2 cells.

<p>BV2 microglial cells were treated with FAC for 24 h. Real-time PCR was used to detect IL-6 mRNA levels. IL-6 mRNA was up-regulated after FAC treatment compared with the untreated control. Each bar represents the mean ± S.E.M of 6 independent experiments (*P < 0.05 compared with the control; n = 6).</p

Graphical representation of the mechanism by which iron load can increase IL-6 mRNA expression, and IL-6 can regulate iron related proteins in BV2 cells.

<p>Iron load can increase IL-6 mRNA expression in BV2 cells. IL-6 up-regulates DMT1 expression and down-regulates FPN1 expression by IRP1 activation in BV2 microglial cells through JNK signaling pathways.</p

Expression of IRP1, DMT1, and FPN1 in BV2 cells treated with IL-6.

<p>A: Western blots to detect IRP1 expression. IRP1 expression was significantly increased in BV2 cells treated with IL-6. B: Western blots to detect DMT1 expression. DMT1 expression was significantly increased in BV2 cells treated with IL-6. C: Western blots to detect FPN1 expression. FPN1 expression was significantly decreased in BV2 cells treated with IL-6. All data are presented as the ratio of iron-related-proteins to β-actin. Each bar represents the mean ± S.E.M of 5 independent experiments (*P < 0.05 compared with control; n = 5).</p