104 research outputs found

    Renormalization properties of a Galilean Wess-Zumino model

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    We consider a Galilean N=2 supersymmetric theory in 2+1 dimensions with F-term couplings, obtained by null reduction of a relativistic Wess-Zumino model. We compute quantum corrections and we check that, as for the relativistic parent theory, the F-term does not receive quantum corrections. Even more, we find evidence that the causal structure of the non-relativistic dynamics together with particle number conservation constrain the theory to be one-loop exact.Comment: 41 pages, 21 figures; v2: references adde

    Natural history of patients with non cirrhotic portal hypertension: Comparison with patients with compensated cirrhosis

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    Background. The knowledge of natural history of patients with portal hypertension (PH) not due to cirrhosis is less well known than that of cirrhotic patients. Aim. To describe the clinical presentation and the outcomes of 89 patients with non-cirrhotic PH (25 with non-cirrhotic portal hypertension, INCPH, and 64 with chronic portal vein thrombosis, PVT) in comparison with 77 patients with Child A cirrhosis. Methods. The patients were submitted to a standardized clinical, laboratory, ultrasonographic and endoscopic follow-up. Variceal progression, incidence of variceal bleeding, portal vein thrombosis, ascites and survival were recorded. Results. At presentation, the prevalence of varices, variceal bleeding and ascites was similar in the 3 groups. During follow-up, the rate of progression to varices at risk of bleeding (p<0.0001) and the incidence of first variceal bleeding (p=0.02) were significantly higher in non-cirrhotic then in cirrhotic patients. A PVT developed in 32% of INCPH patients and in 18% of cirrhotics (p=0.02). Conclusions. In the patients with non–cirrhotic PH variceal progression is more rapid and bleeding more frequent than in cirrhotics. Patients with INCPH are particularly prompt to develop PVT. This observational study suggests that the management of patients with non-cirrhotic PH should take into consideration the natural history of portal hypertension in these patients and cannot be simply derived by the observation of cirrhotic patients

    No effect of albumin infusion on the prevention of hepatic encephalopathy after transjugular intrahepatic portosystemic shunt

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    Hepatic encephalopathy (HE) is a major problem in patients submitted to TIPS. Previous studies identified low albumin as a factor associated to post-TIPS HE. In cirrhotics with diuretic-induced HE and hypovolemia, albumin infusion reduced plasma ammonia and improved HE. Our aim was to evaluate if the incidence of overt HE (grade II or more according to WH) and the modifications of venous blood ammonia and psychometric tests during the first month after TIPS can be prevented by albumin infusion. Twenty-three patients consecutively submitted to TIPS were enrolled and treated with 1 g/Kg BW of albumin for the first 2 days after TIPS followed by 0,5 g/Kg BW at day 4th and 7th and then once a week for 3 weeks. Forty-five patients included in a previous RCT (Riggio et al. 2010) followed with the same protocol and submitted to no pharmacological treatment for the prevention of HE, were used as historical controls. No differences in the incidence of overt HE were observed between the group of patients treated with albumin and historical controls during the first month (34 vs 31 %) or during the follow-up (39 vs 48 %). Two patients in the albumin group and three in historical controls needed the reduction of the stent diameter for persistent HE. Venous blood ammonia levels and psychometric tests were also similarly modified in the two groups. Survival was also similar. Albumin infusion has not a role in the prevention of post-TIPS HE

    Anisotropy and NMR spectroscopy

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    Abstract In this paper, different aspects concerning anisotropy in Nuclear Magnetic Resonance (NMR) spectroscopy have been reviewed. In particular, the relevant theory has been presented, showing how anisotropy stems from the dependence of internal nuclear spin interactions on the molecular orientation with respect to the external magnetic field direction. The consequences of anisotropy in the use of NMR spectroscopy have been critically discussed: on one side, the availability of very detailed structural and dynamic information, and on the other side, the loss of spectral resolution. The experiments used to measure the anisotropic properties in solid and soft materials, where, in contrast to liquids, such properties are not averaged out by the molecular tumbling, have been described. Such experiments can be based either on static low-resolution techniques or on one- and two-dimensional pulse sequences exploiting Magic Angle Spinning (MAS). Examples of applications of NMR spectroscopy have been shown, which exploit anisotropy to obtain important physico-chemical information on several categories of systems, including pharmaceuticals, inorganic materials, polymers, liquid crystals, and self-assembling amphiphiles in water. Solid-state NMR spectroscopy can be considered, nowadays, one of the most powerful characterization techniques for all kinds of solid, either amorphous or crystalline, and semi-solid systems for the obtainment of both structural and dynamic properties on a molecular and supra-molecular scale. Graphic abstrac

    Portal Hypertension Related to Schistosomiasis Treated with a Transjugular Intrahepatic Portosystemic Shunt

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    Hepatosplenic schistosomiasis represents the most common form of chronic intestinal schistosomiasis. Liver periportal fibrosis, leading to portal hypertension, is the major cause of disease morbidity and mortality, due to massive bleeding of esophageal or gastric varices.

    2-(1,2,3,4-Tetra­hydro-1-naphth­yl)imidazolium chloride monohydrate

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    In the title compound, C13H15N2 +·Cl−·H2O, the ions and water mol­ecules are ­connected by N—H⋯Cl, O—H⋯Cl, NH⋯Cl⋯HO, NH⋯Cl⋯HN and OH⋯Cl⋯HO inter­actions, forming discrete D(2) and D 2 1(3) chains, C 2 1(6) chains and R 4 2(8) rings, leading to a neutral two-dimensional network. The crystal structure is further stabilized by π–π stacking inter­actions [centroid–centroid distance = 3.652 (11) Å]

    3-Methyl-1,4-dioxo-1,4-dihydro­naphthalen-2-yl 4-amino­benzoate

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    The crystal structure of the title compound, C18H13NO4, the oxidized form of the drug aminaftone used in venous disease therapy, is characterized by the presence of ribbons of hydrogen-bonded mol­ecules parallel to the [111] crystallographic direction and by stacking inter­actions between rings [centroid–centroid distance between quinone rings = 3.684 (3) Å and between amino­benzoate rings = 4.157 (3) Å] along the ribbons

    4-Amino-N-(3-meth­oxy­pyrazin-2-yl)benzene­sulfonamide

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    The overall mol­ecular geometry of the title compound, C11H12N4O3S, is bent, with a dihedral angle of 89.24 (5)° between the best planes through the two aromatic rings. Each mol­ecule behaves as a hydrogen-bond donor toward three different mol­ecules, through its amidic and the two aminic H atoms, and it behaves as a hydrogen-bond acceptor from two other mol­ecules via one of its sulfonamidic O atoms. In the crystal, mol­ecules linked by N—H⋯N and N—H⋯O hydrogen bonds form kinked layers parallel to (001), adjacent layers being connected by van der Waals inter­actions

    4-(3-Methyl­anilino)-N-[N-(1-methyl­ethyl)carbamo­yl]pyridinium-3-sulfon­amidate (torasemide T–N): a low temperature redetermination

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    The structure [Danilovski et al. (2001 ▶). Croat. Chim. Acta 74, 103–120] of the T–N (non-solvated) polymorph of torasemide, C16H20N4O3S, a diuretic drug used in the treatment of hypertension, has been redetermined at low temperature. The zwitterionic form of the mol­ecule is confirmed, although GAUSSIAN03 calculations suggest that this form is less stable in the gas phase. The unit-cell contraction between 298 and 100 K is approximately isotropic and the largest structual change is in a C—N—C—C torsion angle, which differs by 11.4 (3)° between the room-temperature and low-temperature structures. There are two mol­ecules in the asymmetric unit, both of which contain an intra­molecular N—H⋯N hydrogen bond. In the crystal structure, both mol­ecules form inversion dimers linked by pairs of N—H⋯N hydrogen bonds. Further N—H⋯N and N—H⋯O hydrogen bonds lead to a three-dimensional network. The different hydrogen-bond arrangements and packing motifs in the polymorphs of torasemide are discussed in detail

    {2-Hydr­oxy-3-[4-(2-methoxy­ethyl)­phen­oxy]prop­yl}isopropyl­ammonium hemisuccinate

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    Metoprolol, a widely used adrenoreceptor blocking drug, is commonly administered as the succinate or tartrate salt. The structure of metoprolol succinate, C15H26NO3 +·0.5C4H4O4 2−, is characterized by the presence of ribbons in which cations, generated by N-protonation of the metoprolol mol­ecules, are hydrogen bonded to succinate anions. The dicarboxylic acid transfers its H atoms to two metoprolol mol­ecules; the asymmetric unit contains one cation and half an anion, the latter possessing twofold rotational symmetry. There are localized nets of O—H⋯O and N—H⋯O hydrogen bonds along a ribbon, within centrosymmetric arrangements formed by pairs of metoprolol cations and pairs of anions, each of the latter contributing with one of its carboxyl groups to the localized net. This arrangement is repeated along the ribbon by the operation of the twofold axis bis­ecting the anion, as well as by the lattice translation
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