1,027 research outputs found

    Differential reactivity of the inner and outer positions of Au25(SCH2CH2Ph)18 dimeric staples under place exchange conditions

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    The kinetic anal. of the place exchange reaction on the neutral Au25(SCH2CH2Ph)\u200b18 cluster by using 4-\u200bfluorobenzylthiol and a series of substituted arylthiols allowed us to establish, for the first time, that the selectivity for the inner and outer positions of the dimeric staples of the cluster can be modulated by using incoming thiols with different structures

    Treatment of atherosclerotic renovascular hypertension: review of observational studies and a meta-analysis of randomized clinical trials.

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    open9Atherosclerotic renal artery stenosis can cause ischaemic nephropathy and arterial hypertension. We herein review the observational and randomized clinical trials (RCTs) comparing medical and endovascular treatment for control of hypertension and renal function preservation. Using the Population Intervention Comparison Outcome (PICO) strategy, we identified the relevant studies and performed a novel meta-analysis of all RCTs to determine the efficacy and safety of endovascular treatment when compared with medical therapy. The following outcomes were examined: baseline follow-up difference in mean systolic and diastolic blood pressure (BP), serum creatinine, number of drugs at follow-up, incident events (heart failure, stroke, and worsening renal function), mortality, cumulative relative risk of heart failure, stroke, and worsening renal function. Seven studies comprising a total of 2155 patients (1741 available at follow-up) were considered, including the recently reported CORAL Study. Compared with baseline, diastolic BP fell more at follow-up in patients in the endovascular than in the medical treatment arm (standard difference in means -0.21, 95% confidence interval (CI): -0.342 to -0.078, P = 0.002) despite a greater reduction in the mean number of antihypertensive drugs (standard difference in means -0.201, 95% CI: -0.302 to -0.1, P < 0.001). At variance, follow-up changes (from baseline) of systolic BP, serum creatinine, and incident cardiovascular event rates did not differ between treatment arms. Thus, patients with atherosclerotic renal artery stenosis receiving endovascular treatment required less anti-antihypertensive drugs at follow-up than those medically treated. Notwithstanding this, they evidenced a better control of diastolic BP.openopenCaielli P;Frigo AC;Pengo MF;Rossitto G;Maiolino G;Seccia TM;Calò LA;Miotto D;Rossi GPCaielli, P; Frigo, ANNA CHIARA; Pengo, Mf; Rossitto, G; Maiolino, G; Seccia, TERESA MARIA; Calò, La; Miotto, Diego; Rossi, Gianpaol

    Data from a multidisciplinary poll of 178 expert physicians on the usage of non-vitamin K Oral Anticoagulants in patients with atrial fibrillation and venous thromboembolism

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    This data article contains data from a multidisciplinary questionnaires filled in by 178 expert physicians on the usage of non-vitamin K Oral Anticoagulants in patients with atrial fibrillation (AF) and for the treatment of patients with venous thromboembolism (VTE). The questionnaire consists of 9 statements of clinical complex AF and VTE cases and informative campaign on antithrombotic therapy for stroke prevention in AF. The data are potentially valuable for the scientific community, showing the doubts of different specialists (Internists, Pneumologists, Geriatricians, Cardiologists and Neurologists) with a large experience in prescribing oral anticoagulation in difficult AF and VTE cases (see full list of participants provided). The data obtained in some particular clinical cases such as CHA2DS2-VASc=1, comorbid coronary artery disease, frailty, advanced age, risk of falling and prior haemorrhagic stroke, can be compared with indications from published guidelines and recommendations for future insight and to be considered as a benchmark for future trials in the area or oral anticoagulation for AF and VTE.The data concerning informative campaign on antithrombotic therapy for stroke prevention showed the expert panel agreement on the inclusion of self monitoring of heart rhythm by pulse taking in subjects older than 64 years of age (81% agreement, item 3); knowledge that the risk of stroke associated with AF is almost twice the risk associated with hypertension (95% agreement, item 4); knowledge that the CHA2DS2-VASc score exerts a higher influence on stroke risk compared to AF duration (92% agreement, item 5); knowledge that stroke prevention in AF with a NOAC is more effective, does not cause any higher bleeding risk, and is equally simple compared to aspirin treatment (91% agreement, item 6).Data on strategies to optimise appropriate prescription of antithrombotic therapy showed agreement on the utility of short television advertisements about the risks of stroke associated with AF (79% agreement, item 8), on a campaign encouraging regular control of cardiac rhythm by pulse taking (77% agreement, item 1), on a campaign reporting the advantages of anticoagulation over no antithrombotic therapy (98% agreement, item 2) or of NOACs over aspirin (96% agreement, item 3) or on the practical use of NOAC (93% agreement, item 6) or on stroke and bleeding risk scores (87% agreement, item 7). See Colonna et al. (2017) [1] for further interpretation and discussion

    Stereoselective Solvolysis in the Synthesis of Dorzolamide Intermediates

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    The key intermediate in the synthesis of dorzolamide,(4S,6S)-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-ol-7,7-dioxide,can beobtained in the diastereoisomerically pure form in two straightforwardsteps starting from diastereoisomeric mixtures of cis/trans-(6S)-6-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-yl acetate,regardless of their ratio. The reaction of crucial importance in thisscheme is a remarkably stereoselective solvolysis of the acetate esterin an acetone/phosphate buffer mixture as the solvent system. Investigationof this so far unrecognized stereoselective reaction reveals thatit proceeds via an S(N)1-like pathway as indicated by thecorrelation of the solvolysis rate constants with the Y (OTs) values of different solvent mixtures and by trappingof the reaction intermediate with sodium azide. The structure of (4S,6S)-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-ol-7,7-dioxide was confirmedby single-crystal X-ray analysis

    Axion search with a quantum-limited ferromagnetic haloscope

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    A ferromagnetic axion haloscope searches for Dark Matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter YIG spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin-magnetometer ever realized. The minimum detectable field is 5.5×10195.5\times10^{-19}\,T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant gaee1.7×1011g_{aee}\le1.7\times10^{-11} at 95% CL. The scientific run of our haloscope resulted in the best limit on DM-axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion mass range 42.442.4-43.1μ43.1\,\mueV. This is also the first apparatus to perform an axion mass scanning by changing the static magnetic field.Comment: 4 pages, 4 figure

    Searching for galactic axions through magnetized media: QUAX status report

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    The current status of the QUAX R\&D program is presented. QUAX is a feasibility study for a detection of axion as dark matter based on the coupling to the electrons. The relevant signal is a magnetization change of a magnetic material placed inside a resonant microwave cavity and polarized with a static magnetic field.Comment: Contributed to the 13th Patras Workshop on Axions, WIMPs and WISPs, Thessaloniki, May 15 to 19, 201

    QED Effective Action at Finite Temperature: Two-Loop Dominance

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    We calculate the two-loop effective action of QED for arbitrary constant electromagnetic fields at finite temperature T in the limit of T much smaller than the electron mass. It is shown that in this regime the two-loop contribution always exceeds the influence of the one-loop part due to the thermal excitation of the internal photon. As an application, we study light propagation and photon splitting in the presence of a magnetic background field at low temperature. We furthermore discover a thermally induced contribution to pair production in electric fields.Comment: 34 pages, 4 figures, LaTe

    ATLAS End Cap Toroid Integration and Test

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