Amylin in the periphery II: An updated mini-review

Amylin is a polypeptide that is cosecreted with insulin from the beta cells of the pancreas. Therefore, in states of diabetes in which the beta-cell mass is largely depleted or dysfunctional, insulin and amylin secretion are also lost or dysregulated. While the soluble monomeric form of amylin acts as a hormone that alters physiological responses related to feeding and acts as a specific growth factor, there has been renewed interest in the less-soluble oligomeric and insoluble polymeric forms of human (also monkey and cat) amylin that may contribute to the establishment of a pathophysiological pathway to overt diabetes. With this discovery has grown the hope of minimizing, with appropriate therapy, these toxic forms to preserve the functional (c) not-cell mass. Human beta cells may also be more vulnerable to these forms and one risk factor, a higher fat diet, may promote toxic forms. The generation and utilities of transgenic rodent models, which express enhanced levels of human amylin, have been accompanied by strategies that may lead to the reduction of toxic forms and associated risk factors. The successful definition and faithful expression of the physiological receptors (and complexes) for amylin that may differ for each target organ is an important development in the field of amylin research generally. Besides the heuristic value for the understanding of the molecular biology of receptors, the opportunity to screen and identify nonpeptide analogues that bind the physiological receptors has important implications for biomedicine and clinical practice in relation to treatments for diabetic complications, bone diseases, and eating disorders. In particular, in their capacities to mimic the effects of amylin as a growth factor, amylin analogues may prove useful in the stimulation of beta-cell mass (in conjunction with other factors), reduce the activity of the osteoclast population, and stimulate the regeneration of proximal tubules following toxic insult (and thus avoid the development of renal insufficiency)

Pressure screening in the interior of primary shells in double-wall carbon nanotubes

The pressure response of double-wall carbon nanotubes has been investigated by means of Raman spectroscopy up to 10 GPa. The intensity of the radial breathing modes of the outer tubes decreases rapidly but remain observable up to 9 GPa, exhibiting a behavior similar (but less pronounced) to that of single-wall carbon nanotubes, which undergo a shape distortion at higher pressures. In addition, the tangential band of the external tubes broadens and decreases in amplitude. The corresponding Raman features of the internal tubes appear to be considerably less sensitive to pressure. All findings lead to the conclusion that the outer tubes act as a protection shield for the inner tubes whereas the latter increase the structural stability of the outer tubes upon pressure application.Comment: PDF with 15 pages, 3 figures, 1 table; submitted to Physical Review

On the origin of the λ\lambda-transition in liquid Sulphur

Developing a novel experimental technique, we applied photon correlation spectroscopy using infrared radiation in liquid Sulphur around $T_\lambda$, i.e. in the temperature range where an abrupt increase in viscosity by four orders of magnitude is observed upon heating within few degrees. This allowed us - overcoming photo-induced and absorption effects at visible wavelengths - to reveal a chain relaxation process with characteristic time in the ms range. These results do rehabilitate the validity of the Maxwell relation in Sulphur from an apparent failure, allowing rationalizing the mechanical and thermodynamic behavior of this system within a viscoelastic scenario.Comment: 5 pages, 4 eps figures, accepted in Phys. Rev. Let

Association of the 894G>T polymorphism in the endothelial nitric oxide synthase gene with risk of acute myocardial infarction

Background: This study was designed to investigate the association of the 894G>T polymorphism in the eNOS gene with risk of acute myocardial infarction (AMI), extent of coronary artery disease (CAD) on coronary angiography, and in-hospital mortality after AMI. Methods: We studied 1602 consecutive patients who were enrolled in the GEMIG study. The control group was comprised by 727 individuals, who were randomly selected from the general adult population. Results: The prevalence of the Asp298 variant of eNOS was not found to be significantly and independently associated with risk of AMI (RR = 1.08, 95%CI = 0.77–1.51, P = 0.663), extent of CAD on angiography (OR = 1.18, 95%CI = 0.63–2.23, P = 0.605) and in-hospital mortality (RR = 1.08, 95%CI = 0.29–4.04, P = 0.908). Conclusion: In contrast to previous reports, homozygosity for the Asp298 variant of the 894G>T polymorphism in the eNOS gene was not found to be associated with risk of AMI, extent of CAD and in-hospital mortality after AM

Continuous Monitoring in Evolving Business Networks

The literature on continuous monitoring of cross-organizational processes, executed within virtual enterprises or business networks, considers monitoring as an issue regarding the network formation, since what can be monitored during process execution is fixed when the network is established. In particular, the impact of evolving agreements in such networks on continuous monitoring is not considered. Also, monitoring is limited to process execution progress and simple process data. In this paper, we extend the possible monitoring options by linking monitoring requirements to generic clauses in agreements established across a network and focus on the problem of preserving the continuous monitorability of these clauses when the agreements evolve, i.e. they are introduced, dropped, or updated. We discuss mechanisms to preserve continuous monitorability in a business network for different types of agreement evolution and we design a conceptual and technical architecture for a continuous monitoring IT infrastructure that implements the requirements derived from such mechanisms

Cloud migration patterns: a multi-cloud service architecture perspective

Many organizations migrate their on-premise software systems to the cloud. However, current coarse-grained cloud migration solutions have made a transparent migration of on-premise applications to the cloud a difficult, sometimes trial-and-error based endeavor. This paper suggests a catalogue of fine-grained service-based cloud architecture migration patterns that target multi-cloud settings and are specified with architectural notations. The proposed migration patterns are based on empirical evi-dence from a number of migration projects, best practices for cloud architectures and a systematic literature review of existing research. The pattern catalogue allows an or-ganization to (1) select appropriate architecture migration patterns based on their ob-jectives, (2) compose them to define a migration plan, and (3) extend them based on the identification of new patterns in new contexts

An exploration of the determinants for decision to migrate existing resources to cloud computing using an integrated TOE-DOI model

Migrating existing resources to cloud computing is a strategic organisational decision that can be difficult. It requires the consideration and evaluation of a wide range of technical and organisational aspects. Although a significant amount of attention has been paid by many industrialists and academics to aid migration decisions, the procedure remains difficult. This is mainly due to underestimation of the range of factors and characteristics affecting the decision for cloud migration. Further research is needed to investigate the level of effect these factors have on migration decisions and the overall complexity. This paper aims to explore the level of complexity of the decision to migrate the cloud. A research model based on the diffusion of innovation (DOI) theory and the technology-organization-environment (TOE) framework was developed. The model was tested using exploratory and confirmatory factor analysis. The quantitative analysis shows the level of impact of the identified variables on the decision to migrate. Seven determinants that contribute to the complexity of the decisions are identified. They need to be taken into account to ensure successful migration. This result has expanded the collective knowledge about the complexity of the issues that have to be considered when making decisions to migrate to the cloud. It contributes to the literature that addresses the complex and multidimensional nature of migrating to the cloud

On the Ferroelectric to Paraelectric Structural Transition of BaTiO3 Micro-/Nanoparticles and Their Epoxy Nanocomposites

BaTiO3 is one of the most widely used ceramic components in capacitor formulation due to its exceptional ferroelectric properties. The structural transition from the ferroelectric tetragonal to the paraelectric cubic phase has been studied in both nano- and micro-BaTiO3 particles. Several experimental techniques were employed for characterization purposes (X-ray diffraction-XRD, laser Raman spectroscopy-LRS, differential scanning calorimetry-DSC and broadband dielectric spectroscopy-BDS). All gave evidence for the structural transition from the polar tetragonal to the non-polar cubic phase in both nano- and micro-BaTiO3 particles. Variation of Full Width at Half Maximum (FWHM) with temperature in XRD peaks was employed for the determination of the critical Curie temperature (Tc). In micro-BaTiO3 particles (Tc) lies close to 120 \ub0C, while in nanoparticles the transition is complicated due to the influence of particles\u27 size. Below (Tc) both phases co-exist in nanoparticles. (Tc) was also determined via the temperature dependence of FWHM and found to be 115 \ub0C. DSC, LRS and BDS provided direct results, indicating the transition in both nano- and micro-BaTiO3 particles. Finally, the 15 parts per hundred resin per weight (phr) BaTiO3/epoxy nanocomposite revealed also the transition through the peak formation at approximately 130 \ub0C in the variation of FWHM with temperature. The present work introduces, for the first time, a qualitative tool for the determination and study of the ferroelectric to paraelectric structural transition in both nano- and micro-ferroelectric particles and in their nanocomposites. Moreover, its novelty lies on the effect of crystals\u27 size upon the ferroelectric to the paraelectric phase transition and its influence on physical properties of BaTiO3