Increased plasma viscosity as a reason for inappropriate erythropoietin formation

The aim of this study was to examine whether altered plasma viscosity could contribute to the inappropriately low production rate of erythropoietin (EPO) observed in patients suffering from hypergammaglobulinemias associated with multiple myeloma or Waldenström's disease. We found that the EPO formation in response to anemia in these patients was inversely related to plasma viscosity. A similar inverse relationship between plasma viscosity and EPO production was seen in rats in which EPO formation had been stimulated by exchange transfusion and the plasma viscosity of which was thereby altered by using exchange solutions of different composition to alter plasma viscosity and thus whole blood viscosity independently from hematocrit. Raising the gammaglobulin concentration to approximately 40 mg/ml plasma in the rats almost totally blunted the rise in serum EPO levels despite a fall of the hematocrit to 20%. Determination of renal EPO mRNA levels by RNase protection revealed that the reductions in serum EPO levels at higher plasma viscosities were paralleled by reductions in renal EPO mRNA levels. Taken together, our findings suggest that plasma viscosity may be a significant inhibitory modulator of anemia-induced EPO formation. The increased plasma viscosity in patients with hypergammaglobulinemias may therefore contribute to the inappropriate EPO production, which is a major reason for the anemia developing in these patients

Neurokinin-immunoreactivity in human neuroblastomas Evidence for selective expression of the preprotachykinin (PPT) II gene

AbstractFactors regulating differentiation of the peripheral nervous system (PNS) have been widely studied in neuroblastomas which are tumors of the PNS. Five neuroblastomas were investigated for their content of tachykinin neuropeptides, which arise from two distinct genes which appear differentially expressed in the PNS. Radioimmunoassay and column chromatography revealed large amounts of neurokinin B in three of these tumors and the absence of substance P, neurokinin A, neuropeptide K and neuropeptide γ from all five tumors. This suggests that neuroblastomas can selectively express the preprotachykinin (PPT) II gene and that they may be valuable for investigating the factors involved in the regulation of these two structurally-related neuropeptide genes

PS-XXI, a new synchrotron for the LHC injector

The CERN PS is the oldest link in the LHC injector chain. A separate function substitute synchrotron is discussed. It would keep the versatility of the present machine and have a higher extraction energy to relax the tolerance on the microwave instability threshold at injection into the SPS. Its essential property would be an adjustable h variation near the isochronous regime to meet the requirements imposed by bunch compression at ejection. It would also be equipped with all the correction systems of a modern machine

Almost Diagonalization of Pseudodifferential Operators

In this review we focus on the almost diagonalization of pseudodifferential operators and highlight the advantages that time-frequency techniques provide here. In particular, we retrace the steps of an insightful paper by Gr\"ochenig, who succeeded in characterizing a class of symbols previously investigated by Se\"ostrand by noticing that Gabor frames almost diagonalize the corresponding Weyl operators. This approach also allows to give new and more natural proofs of related results such as boundedness of operators or algebra and Wiener properties of the symbol class. Then, we discuss some recent developments on the theme, namely an extension of these results to a more general family of pseudodifferential operators and similar outcomes for a symbol class closely related to Sj\"ostrand's one.Comment: 19 page

Increasing the Proton Intensity of PS and SPS

Recently, a series of meetings were organised with PS and SPS participants, to discuss the possibilities of increasing the proton intensity on the SPS targets (with particular emphasis to CNGS) as well as ISOLDE and nTOF. Increasing the brilliance of the LHC beam, as required for ultimate LHC performance, was also discussed. Several schemes were proposed, as a staged approach, i.e. starting from the most simple and cheap, though difficult, to the more advanced and expensive. After comparing the advantages and disadvantages of the various methods, three basic schemes were retained as candidates for further investigations and as good / necessary starting points for further improvements. Chapter 1 is devoted to PSB and PS issues and contains essentially a description of the three selected schemes. Chapter 2 deals with limitations in the SPS. Chapter 3 is a synthesis of basic conclusions. In the Appendix, a work-plan is presented for PSB and PS theoretical and experimental studies with a time estimate for preliminary results

The Role of Electron Captures in Chandrasekhar Mass Models for Type Ia Supernovae

The Chandrasekhar mass model for Type Ia Supernovae (SNe Ia) has received increasing support from recent comparisons of observations with light curve predictions and modeling of synthetic spectra. It explains SN Ia events via thermonuclear explosions of accreting white dwarfs in binary stellar systems, being caused by central carbon ignition when the white dwarf approaches the Chandrasekhar mass. As the electron gas in white dwarfs is degenerate, characterized by high Fermi energies for the high density regions in the center, electron capture on intermediate mass and Fe-group nuclei plays an important role in explosive burning. Electron capture affects the central electron fraction Y_e, which determines the composition of the ejecta from such explosions. Up to the present, astrophysical tabulations based on shell model matrix elements were only available for light nuclei in the sd-shell. Recently new Shell Model Monte Carlo (SMMC) and large-scale shell model diagonalization calculations have also been performed for pf-shell nuclei. These lead in general to a reduction of electron capture rates in comparison with previous, more phenomenological, approaches. Making use of these new shell model based rates, we present the first results for the composition of Fe-group nuclei produced in the central regions of SNe Ia and possible changes in the constraints on model parameters like ignition densities and burning front speeds.Comment: 26 pages, 8 figures, submitted to Ap

The effects of particle size, shape, density and flow characteristics on particle margination to vascular walls in cardiovascular diseases

Introduction: Vascular-targeted drug delivery is a promising approach for the treatment of atherosclerosis, due to the vast involvement of endothelium in the initiation and growth of plaque, a characteristic of atherosclerosis. One of the major challenges in carrier design for targeting cardiovascular diseases (CVD) is that carriers must be able to navigate the circulation system and efficiently marginate to the endothelium in order to interact with the target receptors. Areas covered: This review draws on studies that have focused on the role of particle size, shape, and density (along with flow hemodynamics and hemorheology) on the localization of the particles to activated endothelial cell surfaces and vascular walls under different flow conditions, especially those relevant to atherosclerosis. Expert opinion: Generally, the size, shape, and density of a particle affect its adhesion to vascular walls synergistically, and these three factors should be considered simultaneously when designing an optimal carrier for targeting CVD. Available preliminary data should encourage more studies to be conducted to investigate the use of nano-constructs, characterized by a sub-micrometer size, a non-spherical shape, and a high material density to maximize vascular wall margination and minimize capillary entrapment, as carriers for targeting CVD

The interface between silicon and a high-k oxide

The ability to follow Moore's Law has been the basis of the tremendous success of the semiconductor industry in the past decades. To date, the greatest challenge for device scaling is the required replacement of silicon dioxide-based gate oxides by high-k oxides in transistors. Around 2010 high-k oxides are required to have an atomically defined interface with silicon without any interfacial SiO2 layer. The first clean interface between silicon and a high-K oxide has been demonstrated by McKee et al. Nevertheless, the interfacial structure is still under debate. Here we report on first-principles calculations of the formation of the interface between silicon and SrTiO3 and its atomic structure. Based on insights into how the chemical environment affects the interface, a way to engineer seemingly intangible electrical properties to meet technological requirements is outlined. The interface structure and its chemistry provide guidance for the selection process of other high-k gate oxides and for controlling their growth. Our study also shows that atomic control of the interfacial structure can dramatically improve the electronic properties of the interface. The interface presented here serves as a model for a variety of other interfaces between high-k oxides and silicon.Comment: 10 pages, 2 figures (one color