92 research outputs found
Stochastic motion of test particle implies that G varies with time
The aim of this letter is to propose a new description to the time varying
gravitational constant problem, which naturally implements the Dirac's large
numbers hypothesis in a new proposed holographic scenario for the origin of
gravity as an entropic force. We survey the effect of the Stochastic motion of
the test particle in Verlinde's scenario for gravity\cite{Verlinde}. Firstly we
show that we must get the equipartition values for which
leads to the usual Newtonian gravitational constant. Secondly,the stochastic
(Brownian) essence of the motion of the test particle, modifies the Newton's
2'nd law. The direct result is that the Newtonian constant has been time
dependence in resemblance as \cite{Running}.Comment: Accepted in International Journal of Theoretical Physic
In planta expression of human polyQ-expanded huntingtin fragment reveals mechanisms to prevent disease-related protein aggregation
In humans, aggregation of polyglutamine repeat (polyQ) proteins causes disorders such as Huntington’s disease. Although plants express hundreds of polyQ-containing proteins, no pathologies arising from polyQ aggregation have been reported. To investigate this phenomenon, we expressed an aggregation-prone fragment of human huntingtin (HTT) with an expanded polyQ stretch (Q69) in Arabidopsis thaliana plants. In contrast to animal models, we find that Arabidopsis sp. suppresses Q69 aggregation through chloroplast proteostasis. Inhibition of chloroplast proteostasis diminishes the capacity of plants to prevent cytosolic Q69 aggregation. Moreover, endogenous polyQ-containing proteins also aggregate on chloroplast dysfunction. We find tha
Downregulation of organic cation transporters OCT1 (SLC22A1) and OCT3 (SLC22A3) in human hepatocellular carcinoma and their prognostic significance
<p>Abstract</p> <p>Background</p> <p>Organic cation transporters (OCT) are responsible for the uptake and intracellular inactivation of a broad spectrum of endogenous substrates and detoxification of xenobiotics and chemotherapeutics. The transporters became pharmaceutically interesting, because OCTs are determinants of the cytotoxicity of platin derivates and the transport activity has been shown to correlate with the sensitivity of tumors towards tyrosine kinase inhibitors. No data exist about the relevance of OCTs in hepatocellular carcinoma (HCC).</p> <p>Methods</p> <p>OCT1 (<it>SLC22A1</it>) and OCT3 (<it>SLC22A3</it>) mRNA expression was measured in primary human HCC and corresponding non neoplastic tumor surrounding tissue (TST) by real time PCR (n = 53). Protein expression was determined by western blot analysis and immunofluorescence. Data were correlated with the clinicopathological parameters of HCCs.</p> <p>Results</p> <p>Real time PCR showed a downregulation of <it>SLC22A1 </it>and <it>SLC22A3 </it>in HCC compared to TST (p ≤ 0.001). A low <it>SLC22A1 </it>expression was associated with a worse patient survival (p < 0.05). Downregulation was significantly associated with advanced HCC stages, indicated by a higher number of T3 tumors (p = 0.025) with a larger tumor diameter (p = 0.035), a worse differentiation (p = 0.001) and higher AFP-levels (p = 0.019). In accordance, <it>SLC22A1 </it>was less frequently downregulated in tumors with lower stages who underwent transarterial chemoembolization (p < 0.001) and liver transplantation (p = 0.001). Tumors with a low <it>SLC22A1 </it>expression (< median) showed a higher <it>SLC22A3 </it>expression compared to HCC with high <it>SLC22A1 </it>expression (p < 0.001). However, there was no significant difference in tumor characteristics according to the level of the <it>SLC22A3 </it>expression.</p> <p>In the western blot analysis we found a different protein expression pattern in tumor samples with a more diffuse staining in the immunofluorescence suggesting that especially OCT1 is not functional in advanced HCC.</p> <p>Conclusion</p> <p>The downregulation of OCT1 is associated with tumor progression and a worse patient survival.</p
Imidazol-1-ylethylindazole Voltage-Gated Sodium Channel Ligands Are Neuroprotective during Optic Neuritis in a Mouse Model of Multiple Sclerosis
[Image: see text] A series of imidazol-1-ylethylindazole sodium channel ligands were developed and optimized for sodium channel inhibition and in vitro neuroprotective activity. The molecules exhibited displacement of a radiolabeled sodium channel ligand and selectivity for blockade of the inactivated state of cloned neuronal Na(v) channels. Metabolically stable analogue 6 was able to protect retinal ganglion cells during optic neuritis in a mouse model of multiple sclerosis
An Innovative Solution for Carving Ski Based on Retractile Blades
This paper presents the design of a new ski to improve the performances focusing especially on steering conditions. In the proposed solution an additional retractile edge has been added modifying the lower surface of the ski. It consists of a thin stainless steel plate suitably reinforced with two longitudinal ribs welded along the plate borders to create the blades. Then this element is constrained to the ski along the longitudinal symmetry axis. In unload and straight conditions the gap between the ski and the edge is null while in curves the retractile blade is deformed and pushed out by the force applied by the skier, penetrating the snow. The mechanism for the force transmission is based on two revolution joints, allowing small rotations of the boot with respect to the ski and compensating the ski deformation, and several pistons, pushing on the edge. Two ski prototypes have been manufactured, instrumented and tested on a snow track. In particular, in order to show the differences in terms of performance, the modified skis have been compared to the classic version. Additional considerations about the variations on stiffness and friction behavior introduced by the new solution have been drawn too
La délicate distinction des constructions et des améliorations
International audience(Civ. 3e, 18 nov. 2014, n° 13-21.629, non publié, AJDI 2015. 141
Emergency right hemicolectomy in colon carcinoma: A prospective study
The morbidity and mortality in right hemicolectomy for carcinoma of the colon is examined, with particular attention to the influence of emergency surgery and advanced disease. Of the 244 patients who had surgery, 57 required emergency surgery and 187 elective surgery. The overall mortality was 5.7% with no difference statistically between the elective and emergency groups. Anastomotic complications were significantly greater in the groups undergoing emergency resection and elective palliative surgery when compared with elective curative surgery. All patients with advanced disease had a higher morbidity and mortality, both in elective and emergency surgery. The factors most important in relation to mortality and morbidity were thus advanced disease, advanced age and cardiorespiratory complications. This being the case, it is felt that the present management of emergency right hemicolectomy with anastomosis should continue to be the treatment of choice for obstructing or perforated carcinomas of the right colon
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