Flux vacua with approximate flat directions

We present a novel method to obtain type IIB flux vacua with flat directions at tree level. We perform appropriate choices of flux quanta that induce relations between the flux superpotential and its derivatives. This method is implemented in toroidal and Calabi-Yau compactifications in the large complex structure limit. Explicit solutions are obtained and classified on the basis of duality equivalences. In the toroidal case we present solutions with N = 1 and N = 2 supersymmetry and arbitrarily weak coupling. In Calabi-Yaus we find novel perturbatively flat vacua, as well as solutions with non-zero flux superpotential and an axionic flat direction which represent a promising starting point for de Sitter constructions from non-zero F-terms in the complex structure sector. The higher order (perturbative and non-perturbative) effects that can lift these flat directions are discussed. We also outline applications in a wide variety of settings involving the classical Regge growth conjecture, inflation and quintessence, supersymmetry breaking and F-term de Sitter uplifting

Clinical course and features of persistent polyclonal B-cell lymphocytosis with BCL-6 amplification during pregnancy

Background: Persistent polyclonal B-cell lymphocytosis is a rare nonmalignant disorder characterized by mild persistent lymphocyte proliferation with possible evolution to aggressive lymphoma. Its biology is not well known, but it is characterized by a specific immunophenotype with rearrangement of the BCL-2/IGH gene, whereas amplification of the BCL-6 gene has rarely been reported. Given the paucity of reports, it has been hypothesized that this disorder is associated with poor pregnancy outcomes. Case report: To our knowledge, only two successful pregnancies have been described in women with this condition. We report the third successful pregnancy in a patient with PPBL and the first with amplification of the BCL-6 gene. Conclusions: PPBL is still a poorly understood clinical condition with insufficient data to demonstrate an adverse effect on pregnancy. The role of BCL-6 dysregulation in the pathogenesis of PPBL and its prognostic significance are still unknown. Evolution into aggressive clonal lymphoproliferative disorders is possible and prolonged hematologic follow-up is warranted in patients with this rare clinical disorder

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Long-term voluntary ethanol consumption induces impairment of the mechanical performance in the papillary muscle of Sardinian alcohol-preferring rats

he effects of chronic (26 weeks) ethanol consumption on cardiac muscle contractility in Sardinian alcohol-preferring drinkers (sP-D) and Sardinian alcohol-preferring naive (sP-N) rats were investigated. Experiments were carried out 1 week after ethanol administration ceased. Length-tension and force-frequency responses in left ventricular papillary muscles from both sP-D and sP-N rats were recorded in vitro. Papillary muscles were gradually stretched in steps of 5% of the reference (initial) length (L-r) from 100 to 130% L-r. In sP-D rats, length-tension relationships showed a significant reduction in active tension: at optimal length for maximum active tension (130% L-r), the developed force value (1.38 +/- 0.36 mN/mg, dry tissue) was 54% lower than that found in sP-N rats (3.16 +/- 0.6 mN/mg, dry tissue). In sP-D papillary muscles, a decrease in contractile behaviour was also observed in force-frequency responses (0.03-120 pulse/min), when compared with sP-N rats; developed force was found to be reduced by about 2.5 times. These results indicate that long-term ethanol consumption impairs the mechanical performance of sP papillary muscle, inducing a negative inotropic effect

The choice of the intervention in the surgical treatment of nontoxic diffuse multinodular goiter

The choice between sub-total (STT) and total (TT) thyroidectomy in surgical management of multinodular goitre should be based on the disease pathophysiology and the critical review of short and long-term results of these treatments. In order to make a comparative evaluation the authors carried out a retrospective analysis on a series of patients operated from 1970 to 1993 and on the results of a 16.3 years mean follow-up. Of 551 patients operated on the thyroid gland, 389 (70.6%) affected by multinodular goitre were considered. 340 were female and 49 male (39 years medium age). 341 (87.6%) underwent STT and 48 (12.4%) TT. Post-operative opotherapy was adjusted according to hormonal assays. Post-operative vocal cord motility and calcemia were assessed. A routine endocrinological follow-up protocol has been carried out on all patients since 1980. Transitory vocal cord palsy and hypocalcemia were significantly more frequent in TT, while permanent damage was not. Of 40 TT (complete 5 years mean follow-up, 97.5% of the patients reached euthyroidism with replacement therapy. Of 189 STT (complete 16.3 years mean follow-up), 61.4% of the patients received opotherapy. A recurrent goitre was ascertained in 39.1% of the total (73.3% in the patients not receiving opotherapy) and operated in 16.2% of the cases. According to the authors their results support the choice of TT as it matches the rationale of surgical treatment of multinodular non-toxic goitre based on the pathophysiology of the disease. Moreover it allows easy achievement of euthyroidism avoiding goitre relapse and subsequently re-operation, with an incidence of permanent recurrent nerve palsy and hypoparathyroidism not significantly different from that after STT

Preliminary trials on effect of nitrogen nutrition on growth and on secondary metabolism of Achillea millefolium L. ssp collina

The studies on the effect of mineral nutrition on Herbs secondary metabolism and yield could lead an improvement of the production of these plants in industrialised countries, where high quality products are required. It is known that the synthesis of secondary chemicals is affected both environmental and agronomic conditions. A recent trial on Yarrow, growth in different climate localities in Alpine cultivated areas with different agronomic techniques, showed significative differences concerning growth and chemicals composition (1). Furthermore, studies on mineral nutrition of H. perforatum showed the relationship between nitrogen supply and Hypericin content (2). To study the effect of nitrogen nutrition on Yarrow, we made a preliminary trial on Achillea millefolium L. spp Collina growth in nutritive solutions with different nitrogen supplies in greenhouse (T 25\ub0C, UR 60% and 18 h photoperiod). The plants growth on high level of nitrogen, compared to the ones growth on lower level, showed a significative increase of number of shoots (61%), fresh weight of shoots (311 % ), dry weight of shoots (243 %) and shoots/roots ratio (204%). Differences in phytochemicals profile also emerged. References: 1. Donald, P. et al. (2000) Plant Physiology and Biochemistry, 38: 413-420. 2. Giorgi, A. et al. (2005) Journal of Herbs, Spices & Medicinal Plants, 3: 47-58