5,365 research outputs found

    Superheated drop as a neutron spectrometer

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    Superheated drops are known to vaporise when exposed to energetic nuclear radiation since the discovery of bubble chamber. As the degree of superheat increases in a given liquid, less and less energetic neutrons are required to cause nucleation. This property of superheated liquids are being utilised to develope the neutron spectromer. A new principle of neutron spectrometry using Superheated liquid are developed and the developed principle has been tested by Am-Be neutron source.Comment: 9 pages, 8 figures. accepted in Nucl.Instru.MethA,200

    Associazione indipendente tra la riserva di flusso coronarico e le pressioni di riempimento e il rilasciamento del ventricolo sinistro

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    Background: A cross-talk between coronary flow and left ventricular (LV) function is recognized. This study tested the hypothesis that impairment of coronary flow reserve (CFR) in arterial hypertension is associated with LV systolic and diastolic dysfunction, independently on abnormalities of LV geometry. Methods: We studied 59 newly diagnosed, never treated hypertensive patients, using transthoracic Doppler echocardiography, including pulsed Tissue Doppler of mitral annulus and CFR on left anterior descending artery (low dose dipyridamole). The study population was divided in 2 groups according to age-normalized relative wall thickness (RWTn): 36 with normal LV geometry (RWTn ≀ 0.41) and.23 patients with LV concentric geometry (RWTn > 0.41) Results: Patients with LV concentric geometry (RWTn > 0.41) had significantly lower midwall (but not endocardial) shortening, longer isovolumic relaxation time (IVRT), lower Tissue Doppler derived early diastolic velocity (Em), higher ratio of transmitral E velocity to Em and lower CFR than patients with normal LV geometry (RWTn ≀ 0.41). In the whole population lower CFR was significantly associated with lower midwall shortening and Em, longer IVRT and higher E/Em ratio. After controlling for heart rate, mean blood pressure and RWTn, only the relation of CFR with IVRT, Em and E/Em ratio remained significant. Conclusions: Reduced midwall mechanics is associated to lower CFR, a relation depending on LV concentric geometry. A reduced CFR is associated with both impaired relaxation and increased filling pressure, a relation that is independent on LV geometry and pressure load

    Editorial: Special issue “molecules from side reactions”

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    Organic synthesis is a powerful tool that allows researchers to express their scientific creativity [...
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