128 research outputs found

    trans-Carbonyl­chloridobis(tri-p-tolyl­phosphine)rhodium(I) acetone solvate

    Get PDF
    The title compound, [RhCl(C21H21P)2(CO)]·C3H6O, was precipitated in trace yield from a reaction of RhCl(cod)(THP) with P(p-tol)3 in a 1:1 acetone-d 6/CD3OD solution under a hydrogen atmosphere [p-tol = p-tolyl, THP = tris­(hydroxy­meth­yl)phosphine, P(CH2OH)3, and cod = 1,5-cyclo­octa­diene]. The complex displays a square-planar geometry around the RhI atom. The complex mol­ecules and the acetone mol­ecules are linked into a chain along the a axis by inter­molecular C—H⋯Cl and C—H⋯O hydrogen bonds

    Chloridotris[tris­(4-fluoro­phen­yl)phosphine]rhodium(I) methanol solvate

    Get PDF
    In the title compound, [RhCl{P(p-FC6H4)3}3]·CH3OH, the Rh atom adopts a distorted square-planar geometry. Rh, Cl and one P atom lie on a mirror plane, as does the solvent molecule. There are two inter­molecular hydrogen bonds, one between the methanol O atom and an aryl H atom (2.51 Å), and one between the Cl atom and the hydr­oxy H atom of methanol [2.34 (3) Å]. The complex precipitates in trace amounts from a reaction between RhCl(cod)(thp) [cod is 1,5-cyclo­octa­diene and thp is tris­(hydroxy­meth­yl)phos­phine] and P(p-FC6H4)3 under argon in CD3OD. Two C6H4-F units are disordered over two positions; for one the site occupancy factors are ca. 0.53 and 0.47, for the other the values are ca. 0.64 and 0.36. The methyl H atoms of the solvent molecule are disordered across the mirror plane

    trans-Carbonyl­chloridobis(ethyl­diphenyl­phosphine-κP)rhodium(I)

    Get PDF
    The title compound, [RhCl(C14H15P)2(CO)], crystallizes with two almost identical mol­ecules in the asymmetric unit. The mol­ecules have the RhI atom in a square-planar geometry. The crystal structure involves intermolecular C—H⋯O hydrogen bonds

    Transcript Regulation of the Recoded Archaeal α-L-Fucosidase In Vivo

    Get PDF
    Genetic decoding is flexible, due to programmed deviation of the ribosomes from standard translational rules, globally termed “recoding”. In Archaea, recoding has been unequivocally determined only for termination codon readthrough events that regulate the incorporation of the unusual amino acids selenocysteine and pyrrolysine, and for −1 programmed frameshifting that allow the expression of a fully functional α-l-fucosidase in the crenarchaeon Saccharolobus solfataricus, in which several functional interrupted genes have been identified. Increasing evidence suggests that the flexibility of the genetic code decoding could provide an evolutionary advantage in extreme conditions, therefore, the identification and study of interrupted genes in extremophilic Archaea could be important from an astrobiological point of view, providing new information on the origin and evolution of the genetic code and on the limits of life on Earth. In order to shed some light on the mechanism of programmed −1 frameshifting in Archaea, here we report, for the first time, on the analysis of the transcription of this recoded archaeal α-l-fucosidase and of its full-length mutant in different growth conditions in vivo. We found that only the wild type mRNA significantly increased in S. solfataricus after cold shock and in cells grown in minimal medium containing hydrolyzed xyloglucan as carbon source. Our results indicated that the increased level of fucA mRNA cannot be explained by transcript up-regulation alone. A different mechanism related to translation efficiency is discusse

    Acute heart failure in patients with acute aortic syndrome: Pathophysiology and clinical-prognostic implications

    Get PDF
    Aims Although acute heart failure (AHF) is a potential complication of acute aortic syndromes (AAS), its clinical details and management implications have been scarcely evaluated. This study aimed to assess prevalence, pathophysiological mechanisms, impact on treatment, and in-hospital mortality of AHF in AAS. Methods and results Data were collected from a prospective AAS registry (398 patients diagnosed between 2000 and 2013). Patients with AHF were identified by the presence of dyspnoea as the presentation symptom or radiological signs of pulmonary congestion or cardiogenic shock, including patients with cardiac tamponade (CT). AHF frequency was 28% (Stanford type A 32% vs. type B 20%, P = 0.01). Four mechanisms leading to AHF were identified, alone or in combination: CT (26%), aortic regurgitation (25%), myocardial ischaemia (17%), and hypertensive crisis (10%). In type A patients, aortic regurgitation and CT were the most frequent mechanisms, whereas myocardial ischaemia and hypertensive crisis were the most frequent in type B patients. Although no difference was noted for diagnostic times, AHF at presentation led to a longer surgical delay in type A AAS. In-hospital mortality was higher in patients with AHF compared with those without (34% vs. 17%, P < 0.001). After multivariable analysis, AHF was associated with increased risk of in-hospital death (adjusted odds ratio 1.97, 95% confidence interval 1.14-3.36, P = 0.014). Conclusion AHF occurs in more than a quarter of patients with AAS of both type A and type B, is due to a variety of pathophysiological mechanisms, and is associated with increased surgical delay and in-hospital mortality. © 2015 The Authors European Journal of Heart Failure © 2015 European Society of Cardiology

    Prediction of early recurrent thromboembolic event and major bleeding in patients with acute stroke and atrial fibrillation by a risk stratification schema: the ALESSA score study

    Get PDF
    Background and Purposes—This study was designed to derive and validate a score to predict early ischemic events and major bleedings after an acute ischemic stroke in patients with atrial fibrillation. Methods—The derivation cohort consisted of 854 patients with acute ischemic stroke and atrial fibrillation included in prospective series between January 2012 and March 2014. Older age (hazard ratio 1.06 for each additional year; 95% confidence interval, 1.00–1.11) and severe atrial enlargement (hazard ratio, 2.05; 95% confidence interval, 1.08–2.87) were predictors for ischemic outcome events (stroke, transient ischemic attack, and systemic embolism) at 90 days from acute stroke. Small lesions (≤1.5 cm) were inversely correlated with both major bleeding (hazard ratio, 0.39; P=0.03) and ischemic outcome events (hazard ratio, 0.55; 95% confidence interval, 0.30–1.00). We assigned to age ≥80 years 2 points and between 70 and 79 years 1 point; ischemic index lesion >1.5 cm, 1 point; severe atrial enlargement, 1 point (ALESSA score). A logistic regression with the receiver-operating characteristic graph procedure (C statistic) showed an area under the curve of 0.697 (0.632–0.763; P=0.0001) for ischemic outcome events and 0.585 (0.493–0.678; P=0.10) for major bleedings. Results—The validation cohort consisted of 994 patients included in prospective series between April 2014 and June 2016. Logistic regression with the receiver-operating characteristic graph procedure showed an area under the curve of 0.646 (0.529–0.763; P=0.009) for ischemic outcome events and 0.407 (0.275–0.540; P=0.14) for hemorrhagic outcome events. Conclusions—In acute stroke patients with atrial fibrillation, high ALESSA scores were associated with a high risk of ischemic events but not of major bleedings

    Measurement of the thermoelastic properties of crystalline Si fibres

    Get PDF
    In order to reduce the thermal noise in future interferometers for gravitational wave (GW) detectors, new suspension materials with low thermal noise are under investigation. Crystalline silicon seems to be a promising material mainly at low temperature. A new technology to produce crystalline silicon fibres has been realized. Measurements of mechanical and thermal properties of the fibres at room temperature have been performed. Preliminary measurements at low temperature are presented

    Timing of initiation of oral anticoagulants in patients with acute ischemic stroke and atrial fibrillation comparing posterior and anterior circulation strokes

    Get PDF
    Background: The aim of this study in patients with acute posterior ischemic stroke (PS) and atrial fibrillation (AF) were to evaluate the risks of recurrent ischemic event and severe bleeding and these risks in relation with oral anticoagulant therapy (OAT) and its timing. Methods: Patients with PS were prospectively included; the outcome events of these patients were compared with those of patients with anterior stroke (AS) which were taken from previous registries. The primary outcome was the composite of: stroke recurrence, TIA, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding occurring within 90 days from acute stroke. Results: A total of 2,470 patients were available for the analysis: 473 (19.1%) with PS and 1,997 (80.9%) AS. Over 90 days, 213 (8.6%) primary outcome events were recorded: 175 (8.7%) in patients with AS and 38 (8.0%) in those with PS. In patients who initiated OAT within 2 days, the primary outcome occurred in 5 out of 95 patients (5.3%) with PS compared to 21 out of 373 patients (4.3%) with AS (OR 1.07; 95% CI 0.39-2.94). In patients who initiated OAT between days 3 and 7, the primary outcome occurred in 3 out of 103 patients (2.9%) with PS compared to 26 out of 490 patients (5.3%) with AS (OR 0.54; 95% CI 0.16-1.80). Conclusions: Patients with posterior or anterior stroke and AF appear to have similar risks of ischemic or hemorrhagic events at 90 days with no difference concerning the timing of initiation of OAT
    corecore