Structural study of low concentration LiCl aqueous solutions in the liquid, supercooled, and hyperquenched glassy states.

Neutron diffraction experiments on a solution of LiCl in water (R = 40) at ambient conditions and in the supercooled and hyperquenched states are reported and analyzed within the empirical potential structure refinement framework. Evidence for the modifications of the microscopic structure of the solvent in the presence of such a small amount of salt is found at all investigated thermodynamic states. On the other hand, it is evident that the structure of the hyperquenched salty sample is similar to that of pure low density amorphous water, although all the peaks of the radial distribution functions are broader in the present case. Changes upon supercooling or hyperquenching of the ion's hydration shells and contacts are of limited size and evidence for segregation phenomena at these states does not clearly show up, although the presence of water separated contacts between ion of the same sign is intriguing.

Short- and long-term overall results of liver retransplantation: "Doce de Octubre" hospital experience.

INTRODUCTION: The liver retransplantation rate in Spain is about 6%. The main causes are primary nonfunction, vascular complications, chronic rejection, and recurrent liver disease. The results of this procedure are worse than those of first transplantations. PATIENTS AND METHODS: This retrospective study evaluated our experience with 54 retransplantations performed between January 1992 and December 2006, which were 5.6% of the 960 orthotopic liver transplantations (OLT) during this period. RESULTS: In this study, 34.7% of the retransplantations were performed between 4 and 30 days after the first transplantation; another 34.7% were within 1 year. Also, 48.9% of the retransplantations were performed in urgent situations. The main causes for retransplantation during the first month were primary hepatic failure (n = 14) and vascular complications (n = 4). After the first month the main causes were chronic rejection (n = 9), recurrence of hepatic disease (n = 3), and biliary complications (n = 4). Postoperative mortality was 23.9% and morbidity was 76.3%. However, 21.2% of the patients needed a third transplant. The overall rate of patient survival was 60.4% (n = 32) and of graft survival was 56.6% (n = 30). The 5-year actuarial graft survival rate was 65.4% with a mean survival time of 89.84 +/- 8.72 months; the 5-year patient survival rate was 64% with a mean survival time of 114.7 +/- 12.53 months. Worse survival was observed in chronic rejection and in retransplantations performed between 31 and 360 days. CONCLUSIONS: Liver retransplantation presents greater surgical complexity than the first transplantation, but is a good option for patients with failure of the first graft with a 5-year patient and graft survival rate greater than 65%.

Disseminated nocardiosis: a rare infectious complication following non-heart-beating donor liver transplantation.

Nocardiosis is an infrequent disease that affects patients who display a cellular immunodeficiency, such as transplant recipients on immunosuppressive treatment, but uncommonly associated with high morbidity and mortality rates. Disseminated Nocardiosis affecting the central nervous system (CNS), abdomen, skin, and lungs has been described in bone marrow, lung, and kidney transplant recipients. However, to our knowledge, no cases involving all of these structures have been reported in liver transplant recipients. Herein, we have reported a case of CNS, pulmonary, and cutaneous nocardiosis in a liver transplant recipient who experienced hepatitis C virus-related cirrhosis and hepatocellular carcinoma and received the organ from a non-heart-beating donor. At posttransplantation month 7 the patient was admitted to the emergency department with poor general health status, fever, edema, and subcutaneous nodules in the legs. A computed tomography scan revealed multiple nodules disseminated through both lungs, abdomen, brain, and subcutaneous tissue. A needle biopsy was performed into one of the subcutaneous nodules. Cultures of the material tested positive for Nocardia farcinica. Thus, we started treatment with intravenous sulfamethoxazole-trimethoprim (SMZ-TMP), shifting after 1 month to oral therapy. Radiological examination performed after 2 weeks of treatment showed a 70% reduction in subcutaneous, pulmonary, and cerebral lesions. After 6 months of SMZ-TMP treatment, the patient remained free of the symptoms with involution of the subcutaneous nodules and significant radiological improvement. Among opportunistic infections appearing in liver transplant recipients, Nocardia species should have special consideration according to the success of early treatment and the bad prognosis in cases of delayed diagnosis.

Vitrification of a monatomic metallic liquid.

Although the majority of glasses in use in technology are complex mixtures of oxides or chalcogenides, there are numerous examples of pure substances-'glassformers'-that also fail to crystallize during cooling. Most glassformers are organic molecular systems, but there are important inorganic examples too, such as silicon dioxide and elemental selenium (the latter being polymeric). Bulk metallic glasses can now be made; but, with the exception of Zr50Cu50 (ref. 4), they require multiple components to avoid crystallization during normal liquid cooling. Two-component 'metglasses' can often be achieved by hyperquenching, but this has not hitherto been achieved with a single-component system. Glasses form when crystal nucleation rates are slow, although the factors that create the slow nucleation conditions are not well understood. Here we apply the insights gained in a recent molecular dynamics simulation study to create conditions for successful vitrification of metallic liquid germanium. Our results also provide micrographic evidence for a rare polyamorphic transition preceding crystallization of the diamond cubic phase.

Dynamics of solvation-induced structural transitions in mesoscopic binary clusters

Ion solvation dynamics following collision of K+ with mesoscopic water-ammonia aggregates is investigated. Two processes determine the postcollision state of the clusters: First, a morphological transformation from a structure characterized by a solid water core and a liquid-phase ammonia sheath into a dumbbell-shaped cluster composed of a liquid water droplet attached to an ammonia subcluster containing the solvated ion. Second, evaporation cools the cluster during and after the morphological change and this evaporative cooling is quantitatively characterized by determining the size-dependent rate constants for these complex clusters.

Production and characterization of two monoclonal antibodies specific for Plasmopara halstedii.

Sunflower downy mildew, caused by the fungus Plasmopara halstedii, is a potentially devastating disease. We produced two monoclonal antibodies (MAbs) (12C9 and 18E2) by immunizing mice with a partially purified extract of P. halstedii race 1. Both MAbs detected in enzyme-linked immunosorbent assay (ELISA) all races of P. halstedii present in France. No cross-reactions were observed with Plasmopara viticola or with other fungi commonly associated with sunflowers. Both MAbs recognized the same three fungal antigens with molecular masses of 68, 140, and 192 kDa. However, the epitopes on the fungal antigens were distinct and repetitive. Seed homogenates from infected plants were incubated in wells coated with MAb 18E2. This resulted in the trapping of P. halstedii antigens that were identified with biotinylated MAb 12C9. No reactions were seen with seed homogenates from healthy plants. Thus, our results suggest that these MAbs might be used to develop a sandwich ELISA detection system for P. halstedii in infected seeds.