Prevention of Intradialytic Hypotension in Patients with Acute Kidney Injury Submitted to Sustained Low-Efficiency Dialysis

Objectives: This study evaluated the effects of a protocol aiming to reduce hypotension in acute kidney injury (AKI) patients submitted to sustained low-efficiency dialysis (SLED). Methods: Patients were randomly assigned to two SLED prescriptions-control group, dialysate temperature was 37.0 degrees C with a fixed sodium concentration [138 mEq/L] and ultrafiltration (UF) rate; and profiling group, dialysate temperature was 35.5 degrees C with a variable sodium concentration [150-138 mEq/L] and UF rate. Results: Sixty-two SLED sessions were evaluated (34 in profiling and 28 in control). Patients (n = 31) were similar in terms of gender, age, and Sequential Organ Failure Assessment (SOFA) score. Dialysis time, dialysis dose, and post-dialysis serum sodium were similar in both groups. The profiling group had significantly less hypotension episodes (23% vs. 57% in control, p = 0.009) and achieved higher UF volume (2.23 +/- 1.25 L vs. 1.59 +/- 1.03 L in control, p = 0.04) when compared with control group. Conclusions: SLED protocol with modulation of dialysate temperature, sodium, and UF profiling showed similar efficacy but less intradialytic hypotension when compared with a standard SLED prescription.

Comparative Analysis of the Closed Quotient for Lip and Tongue Trills in Relation to the Sustained Vowel /epsilon/

Various types of trill exercises have been used for a long time as a tool in the treatment and preparation of the voice. Although they are reported to produce vocal benefits in most subjects, their physiology has not yet been studied in depth. The aim of this study was to compare the mean and standard deviation of the closed quotient in exercises of lip and tongue trills with the sustained vowel /epsilon/ in opera singers. Ten professional classical (operatic) singers, reportedly in perfect laryngeal health, served as subjects for this study and underwent electroglottography. During the examination, the subjects were instructed to deliver the sustained vowel /epsilon/ and lip and tongue trills in a same preestablished frequency and intensity. The mean values and standard deviation of the closed quotient were obtained using the software developed for this purpose. The comparison of the results was intrasubjects; maximum intensities were compared only among them and so were minimum intensities. The means of closed quotient were statistically significant only in the strong intensities, and the lip trill was different from the tongue trill and the sustained vowel /epsilon/. The standard deviation of the closed quotient distinguished the sustained vowel /epsilon/ from the lip and tongue trills in the two intensities. We concluded that there is oscillation of the closed quotient during the exercises of tongue and lip trills, and the closed quotient is higher during the performance of exercises of the lip trill, when compared with the two other utterances, only in the strong intensities.

Generalized non-commutative inflation

Non-commutative geometry indicates a deformation of the energy-momentum dispersion relation f (E) = E/pc (not equal 1) for massless particles. This distorted energy-momentum relation can affect the radiation-dominated phase of the universe at sufficiently high temperature. This prompted the idea of non-commutative inflation by Alexander et al (2003 Phys. Rev. D 67 081301) and Koh and Brandenberger (2007 JCAP06(2007) 021 and JCAP11(2007) 013). These authors studied a one-parameter family of a non-relativistic dispersion relation that leads to inflation: the a family of curves f (E) = 1 + (lambda E)(alpha). We show here how the conceptually different structure of symmetries of non-commutative spaces can lead, in a mathematically consistent way, to the fundamental equations of non-commutative inflation driven by radiation. We describe how this structure can be considered independently of (but including) the idea of non-commutative spaces as a starting point of the general inflationary deformation of SL(2, C). We analyze the conditions on the dispersion relation that leads to inflation as a set of inequalities which plays the same role as the slow-roll conditions on the potential of a scalar field. We study conditions for a possible numerical approach to obtain a general one-parameter family of dispersion relations that lead to successful inflation.

Chronic infusion of amyloid-β peptide and sustained attention altered α7 nicotinic receptor density in the rat brain

It is already known that progressive degeneration of cholinergic neurons in brain areas such as the hippocampus and the cortex leads to memory deficits, as observed in Alzheimer's disease. This work verified the effects of the infusion of amyloid-beta (A beta) peptide associated to an attentional rehearsal on the density of alpha 7 nicotinic cholinergic receptor (nAChR) in the brain of male Wistar rats. Animals received intracerebroventricular infusion of A beta or vehicle (control - C) and their attention was stimulated weekly (Stimulated A beta group: S-A beta and Stimulated Control group: SC) or not (Non-Stimulated A beta group: N-SA beta and Non-Stimulated Control group: N-SC), using an active avoidance apparatus. Conditioned avoidance responses (CAR) were registered. Chronic infusion of A beta caused a 37% reduction in CAR for N-SA beta. In S-A beta, this reduction was not observed. At the end, brains were extracted and autoradiography for alpha 7 nAChR was conducted using [I-125]-alpha-bungarotoxin. There was an increase in alpha 7 density in hippocampus, cortex and amygdala of SA beta animals, together with the memory preservation. In recent findings from our lab using mice infused with A beta and the alpha 7 antagonist methyllycaconitine, and stimulated weekly in the same apparatus, it was observed that memory maintenance was abolished. So, the increase in alpha 7 density in brain areas related to memory might be related to a participation of this receptor in the long-lasting change in synaptic plasticity, which is important to improve and maintain memory consolidation.

Structural studies of Helicase NS3 variants from Hepatitis C virus genotype 3 in virological sustained responder and non-responder patients

Abstract Background About 130 million people are infected with the hepatitis C virus (HCV) worldwide, but effective treatment options are not yet available. One of the most promising targets for antiviral therapy is nonstructural protein 3 (NS3). To identify possible changes in the structure of NS3 associated with virological sustained response or non-response of patients, a model was constructed for each helicase NS3 protein coding sequence. From this, the goal was to verify the interaction between helicases variants and their ligands. Findings Evidence was found that the NS3 helicase portion of non-responder patients contained substitutions in its ATP and RNA binding sites. K210E substitution can cause an imbalance in the distribution of loads, leading to a decrease in the number of ligations between the essential amino acids required for the hydrolysis of ATP. W501R substitution causes an imbalance in the distribution of loads, leading and forcing the RNA to interact with the amino acid Thr269, but not preventing binding of ribavirin inhibitor. Conclusions Useful information is provided on the genetic profiling of the HCV genotype 3, specifically the coding region of the NS3 protein, improving our understanding of the viral genome and the regions of its protein catalytic site.

Conceptual problem for noncommutative inflation and the new approach for nonrelativistic inflationary equation of state

In a previous paper, we connected the phenomenological noncommutative inflation of Alexander, Brandenberger and Magueijo [ Phys. Rev. D 67 081301 (2003)] and Koh and Brandenberger [ J. Cosmol. Astropart Phys. 2007 21 ()] with the formal representation theory of groups and algebras and analyzed minimal conditions that the deformed dispersion relation should satisfy in order to lead to a successful inflation. In that paper, we showed that elementary tools of algebra allow a group-like procedure in which even Hopf algebras (roughly the symmetries of noncommutative spaces) could lead to the equation of state of inflationary radiation. Nevertheless, in this paper, we show that there exists a conceptual problem with the kind of representation that leads to the fundamental equations of the model. The problem comes from an incompatibility between one of the minimal conditions for successful inflation (the momentum of individual photons being bounded from above) and the Fock-space structure of the representation which leads to the fundamental inflationary equations of state. We show that the Fock structure, although mathematically allowed, would lead to problems with the overall consistency of physics, like leading to a problematic scattering theory, for example. We suggest replacing the Fock space by one of two possible structures that we propose. One of them relates to the general theory of Hopf algebras (here explained at an elementary level) while the other is based on a representation theorem of von Neumann algebras (a generalization of the Clebsch-Gordan coefficients), a proposal already suggested by us to take into account interactions in the inflationary equation of state.

From inflation to dark energy through a dynamical Λ: an attempt at alleviating fundamental cosmic puzzles

After decades of successful hot big-bang paradigm, cosmology still lacks a framework in which the early inflationary phase of the universe smoothly matches the radiation epoch and evolves to the present “quasi” de Sitter spacetime. No less intriguing is that the current value of the effective vacuum energy density is vastly smaller than the value that triggered inflation. In this paper, we propose a new class of cosmologies capable of overcoming, or highly alleviating, some of these acute cosmic puzzles. Powered by a decaying vacuum energy density, the spacetime emerges from a pure nonsingular de Sitter vacuum stage, “gracefully” exits from inflation to a radiation phase followed by dark matter and vacuum regimes, and, finally, evolves to a late-time de Sitter phase.