Electronic Structure and Lattice dynamics of NaFeAs

The similarity of the electronic structures of NaFeAs and other Fe pnictides has been demonstrated on the basis of first-principle calculations. The global double-degeneracy of electronic bands along X-M and R-A direction indicates the instability of Fe pnictides and is explained on the basis of a tight-binding model. The de Haas-van Alphen parameters for the Fermi surface (FS) of NaFeAs have been calculated. A $\mathbf{Q}_{M}=(1/2,1/2,0)$ spin density wave (SDW) instead of a charge density wave (CDW) ground state is predicted based on the calculated generalized susceptibility $\chi(\mathbf{q})$ and a criterion derived from a restricted Hatree-Fock model. The strongest electron-phonon (e-p) coupling has been found to involve only As, Na z-direction vibration with linear-response calculations. A possible enhancement mechanism for e-p coupling due to correlation is suggested

Isolated aortic root dilation in homocystinuria

BACKGROUND: Vascular complications in homocystinuria have been known for many years, but there have been no reports to date on involvement of the ascending aorta. METHODS: We conducted a cross-sectional study of patients with homocystinuria, known to a single metabolic centre, and evaluated in 2016 with a transthoracic echocardiogram. Aortic root dilation was defined as Z-score ≥ 2.0 SD, and graded mild (Z-score 2.0-3.0), moderate (Z-score 3.01-4.0) and severe (Z-score > 4.0). RESULTS: The study population included 34 patients, median age of 44.3 years (IQR 33.3-52.2), 50% males, 69% diagnosed aged <18 years and 29% pyridoxine-responsive. Eight (24%) had a history of hypertension. Seven patients (21%) were found to have a dilation of the aortic root, mild in two cases (6%), moderate in four (12%) and severe in one (3%). None had dilation of the ascending aorta. Significant aortic regurgitation, secondary to moderate aortic root dilation, was documented in two patients. A single patient had significant mitral regurgitation due to prolapse of both valve leaflets, as well as mild aortic root dilation. Comparing patients with a dilation of the aortic root to those without, there were no significant clinical, laboratory or echocardiographic differences, with the only exception being that the diameter of the ascending aorta was larger in the group with a dilated aortic root, albeit within normal limits. CONCLUSIONS: A subset of patients with homocystinuria have isolated dilation of the aortic root similar to that observed in Marfan syndrome

Identification of the endophilins (SH3p4/p8/p13) as novel binding partners for the beta1-adrenergic receptor.

Several G-protein coupled receptors, such as the beta1-adrenergic receptor (beta1-AR), contain polyproline motifs within their intracellular domains. Such motifs in other proteins are known to mediate protein-protein interactions such as with Src homology (SH)3 domains. Accordingly, we used the proline-rich third intracellular loop of the beta1-AR either as a glutathione S-transferase fusion protein in biochemical "pull-down" assays or as bait in the yeast two-hybrid system to search for interacting proteins. Both approaches identified SH3p4/p8/p13 (also referred to as endophilin 1/2/3), a SH3 domain-containing protein family, as binding partners for the beta1-AR. In vitro and in human embryonic kidney (HEK) 293 cells, SH3p4 specifically binds to the third intracellular loop of the beta1-AR but not to that of the beta2-AR. Moreover, this interaction is mediated by the C-terminal SH3 domain of SH3p4. Functionally, overexpression of SH3p4 promotes agonist-induced internalization and modestly decreases the Gs coupling efficacy of beta1-ARs in HEK293 cells while having no effect on beta2-ARs. Thus, our studies demonstrate a role of the SH3p4/p8/p13 protein family in beta1-AR signaling and suggest that interaction between proline-rich motifs and SH3-containing proteins may represent a previously underappreciated aspect of G-protein coupled receptor signaling

Is the abundance of Faecalibacterium prausnitzii relevant to Crohn's disease?

Reports that bacteria within the Firmicutes phylum, especially the species Faecalibacterium prausnitzii, are less abundant in Crohn’s disease (CD) patients and supernatants from cultures of this bacterium are anti-inflammatory prompted the investigation of the possible correlations between the abundance of F.prausnitzii and the response to treatment in patients with gut diseases and healthy controls. In a randomized, double-blind trial, faeces were collected from healthy volunteers, and from patients with active CD, ulcerative colitis (UC) and irritable bowel syndrome before and after treatment. The levels of F. prausnitzii DNA in faecal suspensions were determined by PCR. Treatment by an elemental diet was effective, resulting in decreases in both the Harvey and Bradshaw index (P<0.001) and the concentrations of serum C-reactive protein (P<0.05). The total levels of F. prausnitzii in faecal samples from CD patients at presentation were lower than those in the other groups both before and after the treatment. There was no correlation between F. prausnitzii abundance and the severity of CD before treatment. Clinical improvement unexpectedly correlated with a significant decrease in the abundance of F. prausnitzii, especially the A2-165 subgroup (P<0.05). Our data suggest that a paucity of F. prausnitzii in the gastrointestinal microbial communities is likely to be a minor aetiological factor in CD: recovery following elemental diet is attributed to lower levels of gut flora

Recovery of end-organs and improved mortality in adult patient on ECMO.

Title: Recovery of End-Organs and Improved Mortality in Adult Patients on ECMO Joshua K Wong, BS1, Vei Shaun Siow, BS1, Thomas N Smith, BS1, Harrison Pitcher, MD2, Linda Bogar, MD2, Hitoshi Hirose, MD2 and Nicholas C Cavarocchi, MD2. 1Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, United States, 19107 and 2Division of Cardiothoracic Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States, 19107. Body: With increasing use of ECMO in adults, we seek to objectively measure End-Organ recovery and correlate intensive care mortality scores and complications with patient survival. This is a retrospective review of patients who were placed on ECMO from Oct 2010 to Dec 2011. End-Organ function was measured through Pa02/Fi02 ratios, lactate levels, MELD and mortality scores (SAPSII/APACHEII/SOFA). Complications were recorded and analyzed. Twenty-three patients were placed on VA-ECMO and 5 on VV-ECMO. 22 (73%) patients were successfully weaned off ECMO, and 13 (46%) survived to discharge. In 12 patients with liver injury pre-ECMO, the median MELD score was 21 vs 13 post-ECMO (

Contrasting Pressure Effects in Sr2VFeAsO3 and Sr2ScFePO3

We report the resistivity measurements under pressure of two Fe-based superconductors with a thick perovskite oxide layer, Sr2VFeAsO3 and Sr2ScFePO3. The superconducting transition temperature Tc of Sr2VFeAsO3 markedly increases with increasing pressure. Its onset value, which was Tc{onset}=36.4 K at ambient pressure, increases to Tc{onset}=46.0 K at ~4 GPa, ensuring the potential of the "21113" system as a high-Tc material. However, the superconductivity of Sr2ScFePO3 is strongly suppressed under pressure. The Tc{onset} of ~16 K decreases to ~5 K at ~4 GPa, and the zero-resistance state is almost lost. We discuss the factor that induces this contrasting pressure effect.Comment: 5 pages, 4 figures, to be published in J. Phys. Soc. Jpn. No.12 (2009

Possible high temperature superconductivity in Ti-doped A-Sc-Fe-As-O (A= Ca, Sr) system

We report a systematic study on the effect of partial substitution of Sc$^{3+}$ by Ti$^{4+}$ in Sr$_{2}$ScFeAsO$_{3}$, Ca$_{2}$ScFeAsO$_{3}$ and Sr$_{3}$Sc$_{2}$Fe$_{2}$As$_{2}$O$_{5}$ on their electrical properties. High level of doping results in an increased carrier concentration and leads to the appearance of superconductivity with the onset of T$_{c}$ up to 45 K.Comment: 8 pages, 4 figures, 2 new figure