Astrochemical evolution along star formation: Overview of the IRAM Large Program ASAI.

Evidence is mounting that the small bodies of our Solar System, such as comets and asteroids, have at least partially inherited their chemical composition from the first phases of the Solar System formation. It then appears that the molecular complexity of these small bodies is most likely related to the earliest stages of star formation. It is therefore important to characterize and to understand how the chemical evolution changes with solar-type protostellar evolution. We present here the Large Program "Astrochemical Surveys At IRAM" (ASAI). Its goal is to carry out unbiased millimeter line surveys between 80 and 272 GHz of a sample of ten template sources, which fully cover the first stages of the formation process of solar-type stars, from prestellar cores to the late protostellar phase. In this article, we present an overview of the surveys and results obtained from the analysis of the 3 mm band observations. The number of detected main isotopic species barely varies with the evolutionary stage and is found to be very similar to that of massive star-forming regions. The molecular content in O- and C- bearing species allows us to define two chemical classes of envelopes, whose composition is dominated by either a) a rich content in O-rich complex organic molecules, associated with hot corino sources, or b) a rich content in hydrocarbons, typical of Warm Carbon Chain Chemistry sources. Overall, a high chemical richness is found to be present already in the initial phases of solar-type star formation.

Laboratory measurements and astronomical search for cyanomethanimine.

CONTEXT: C-cyanomethanimine (HNCHCN), existing in the two Z and E isomeric forms, is a key prebiotic molecule, but, so far, only the E isomer has been detected toward the massive star-forming region. Sagittarius B2(N) using transitions in the radio wavelength domain. AIMS: With the aim of detecting HNCHCN in Sun-like-star forming regions, the laboratory investigation of its rotational spectrum has been extended to the millimeter-/submillimeter-wave (mm-/submm-) spectral window in which several unbiased spectral surveys have been already carried out. METHODS: High-resolution laboratory measurements of the rotational spectrum of C-cyanomethanimine were carried out in the 100-420 GHz range using a frequency-modulation absorption spectrometer. We then searched for the C-cyanomethanimine spectral features in the mm-wave range using the high-sensitivity and unbiased spectral surveys obtained with the IRAM 30-m antenna in the ASAI context, the earliest stages of star formation from starless to evolved Class I objects being sampled. RESULTS: For both the Z and E isomers, the spectroscopic work has led to an improved and extended knowledge of the spectroscopic parameters, thus providing accurate predictions of the rotational signatures up to ~700 GHz. So far, no C-cyanomethanimine emission has been detected toward the ASAI targets, and upper limits of the column density of ~ 1011-1012 cm-2 could only be derived. Consequently, the C-cyanomethanimine abundances have to be less than a few 10-10 for starless and hot-corinos. A less stringent constraint, ≤ 10-9, is obtained for shocks sites. CONCLUSIONS: The combination of the upper limits of the abundances of C-cyanomethanimine together with accurate laboratory frequencies up to ~ 700 GHz poses the basis for future higher sensitivity searches around Sun-like-star forming regions. For compact (typically less than 1″) and chemically enriched sources such as hot-corinos, the use of interferometers as NOEMA and ALMA in their extended configurations are clearly needed.

[Therapy with nitro derivatives and the development of tolerance: a comparative study with stress ECG and dipyridamole ECG]. / Terapia con nitroderivati e sviluppo di tolleranza: studio comparativo con ECG da sforzo ed ECG-dipiridamolo.

The ECG stress test represents the most commonly-used technique to evaluate the occurrence of nitroglycerin tolerance. It acts by increasing cardiac O2 demand with resulting insufficient blood flow through a stenotic coronary artery and development of cardiac ischemia. However, other tests are also potentially suitable, such as the ECG-dipyridamole test. The aim of the present study was to evaluate the acute response of ECG-dipyridamole and ECG-stress tests to nitroglycerin. In particular, the development of nitroglycerin tolerance during chronic therapy was evaluated with both tests in patients with stable angina. Eleven patients (8 men and 3 women) with CAD proven by a previous coronarography, a known history of stable angina within at least six months and a positive response to both the tests were studied. At the end of a seven-day wash-out period, all patients were positive to initial ECG-stress and ECG-dipyridamole tests; after 3 days a new evaluation was carried out (Effort 0 and Dip 0) and this confirmed the previous results. We performed a randomized trial in two phases: acute and chronic therapy. In the acute phase, all patients underwent ECG-stress and ECG-dipyridamole tests (Effort 1 and Dip 1) in a randomized fashion one day apart, four hours after administration of a 10 mg/24 h nitroglycerin patch. The chronic phase consisted of 25 days of continuous treatment with a nitroglycerin patch. The two tests (Effort 2 and Dip 2) were always repeated after four hours of the morning therapy. Nitroglycerin does not modify the hemodynamic response to dipirydamole in either acute or chronic treatment. Lastly, our data confirm the efficacy of nitroglycerin on stress and dipyridamole tests after acute administration. Nitroglycerin tolerance is confirmed by both tests although with different patterns. ECG stress test showed nitroglycerin tolerance because time to ischemia and max ST deteriorated during chronic therapy. Moreover, the ECG-dipyridamole test showed nitroglycerin tolerance because five patients with a negative acute test (Dip 1) became positive during chronic therapy (Dip 2).

Hemodynamic effects of creatine phosphate in patients with congestive heart failure: a double-blind comparison trial versus placebo.

BACKGROUND: The use of metabolic drugs effective in addition to conventional therapy represents a significant challenge in patients with left ventricular dysfunction. HYPOTHESIS: The aim of this double-blind, placebo-controlled study was to investigate the hemodynamic effects of acute intravenous (i.v.) administration of creatine phosphate (CP) and of short-term treatment in patients with congestive heart failure (CHF) from ischemic heart disease (IHD) or dilated cardiomyopathy in addition to conventional therapy. METHODS: We compared the hemodynamic effects of exogenous creatine phosphate (CP) and placebo in a double-blind, crossover design study in 13 hospitalized patients (12 men, 1 woman, mean age 52 +/- 8 years) with CHF. All patients were in New York Heart Association (NYHA) class II-III and received conventional pharmacologic therapy for CHF; this was not changed during the study period. The study design consisted of two treatment periods (CP or placebo and placebo or CP, respectively) of 4 days each, separated by a 2-day washout interval. The intravenous infusion consisted of 6 g CP or placebo (acute treatment) or 6 g CP or placebo daily for 4 days (short-term treatment) diluted in 50 ml of NaCl 0.9%; infusion duration was about 10 min. Mono-bidimensional echocardiographic examination (Hewlett Packard Sonos 1000, with a 2.5 MHz transducer) was performed at baseline, after acute infusion, and 12 h after the end of short-term treatment. Data were analyzed by ANOVA and Student's t-test for paired data; the results obtained after acute and short-term therapy were compared with the baseline values. RESULTS: After placebo therapy, no significant change was observed. The results after treatment with CP showed a significant reduction of end-systolic diameter [baseline: 4.5 +/- 0.6; acute: 4.2 +/- 0.5, (p < 0.001); short-term 4.3 +/- 0.6 cm, (p < 0.05)] and systemic vascular resistance (baseline: 1064.9 +/- 483.7; acute: 947.5 +/- 390.2 (p < 0.05); short-term: 950.7 +/- 394.3 dyne-s-cm-5 (p < 0.05); moreover, a significant increase of percent ejection fraction [baseline: 48 +/- 12%; acute 53 +/- 12% (p < 0.01); short-term 52 +/- 11% (p < 0.01)], and of percent fractional shortening [baseline: 25 +/- 7; acute 28 +/- 8 (p < 0.05); short-term 28 +/- 7% (p < 0.05)] was observed. CONCLUSION: CP was shown to improve cardiac function, even in the presence of a conventional CHF pharmacologic therapy.

A water-vapour giga-maser in the active galaxy TXFS2226-184.

Active galactic nuclei are thought to be powered by gas falling into a massive black hole; the different types of active galaxy may arise because we view them through a thick torus of molecular gas at varying angles of inclination. One way to determine whether the black hole is surrounded by a torus, which would obscure the accretion disk around the black hole along certain lines of sight, is to search for water masers, as these exist only in regions with plentiful molecular gas. Since the first detection of an extra-galactic water maser in 1979, they have come to be associated primarily with active galaxies, and have even been used to probe the mass of the central engine. Here we report the detection of a water giga-maser in the radio galaxy TXFS2226-184. The strength of the emission supports a recently proposed theory of maser pumping that allows for even more powerful masers, which might be detectable at cosmological distances. Water masers may accordingly provide a way to determine distances to galaxies outside the usual distance ladder, providing an independent calibration of the Hubble constant.

[ECG-dipyridamole and ECG-exercise test in the assessment of ischemic cardiopathy: effects of the acute administration of nitroglycerin]. / ECG-dipiridamolo ed ECG da sforzo nella valutazione della cardiopatia ischemica: effetti della somministrazione acuta di nitroglicerina.

It is known that intravenous administration of dipyridamole can induce chest pain and ECG signs of ischemia in patients with coronary artery disease. In the present study we evaluated ECG and hemodynamic changes in response to dipyridamole (0.56 mg/kg in 10 min) under basal conditions and 3 hours after administration of nitroglycerin (10 mg/24 h patch) in 14 patients with coronary artery disease. The effects of nitroglycerin were also compared to those induced by the same drug on a bicycle stress test in the same patients. Exercise stress test induced specific ST changes in all patients when performed off-drug. Nitroglycerin administration completely prevented exercise-induced ischemia in 2 patients, and significantly prolonged exercise time in the remaining patients (p < 0.01). This effect was accompanied by a significant increase in heart rate (HR) and rate-pressure product at the threshold of ischemia (HRBP, p < 0.01); furthermore we observed a significant increase in HR at the maximal work load (p < 0.05). In the absence of treatment, dipyridamole infusion induced ST segment changes and/or typical chest pain in 12/14 patients. Moreover we observed a significant increase (p < 0.05) in HR, BP and HRBP during the test with respect to basal conditions. Following nitroglycerin administration, dipyridamole infusion failed to induce ischemia in 4 patients, and the time to ST depression in the remaining 8 patients (459 +/- 69 vs 610 +/- 127 s; p < 0.05) was significantly prolonged.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cardiac function (angiocardioscintigraphic evaluation) and plasma catecholamine levels in non-insulin-dependent diabetics]. / Funzione cardiaca (valutazione angiocardioscintigrafica) e livelli plasmatici di catecolamine nei diabetici non insulino-dipendenti.

Cardiac mortality is more frequent in diabetic patients than in normal subjects and particularly heart failure occurs 4-6 times more frequently in these patients than in normals also excluding diabetics with coronary artery disease (CAD). To study cardiac function, 20 patients with type II diabetes mellitus (11 M and 9 F, mean age 48 +/- 9 years), and 13 normal subjects (6 M and 7 F, mean age 48 +/- 13 years), were submitted to radionuclide ventriculography with technetium 99m to evaluate some indices of cardiac function at rest and during effort. The diabetic patients were on good metabolic control testified by a satisfactory fasting and post prandial glycaemia, absence of glycosuria in the last 3 monthly controls and a normal value of glycosylate haemoglobin; they had no vascular or neurological complications; CAD was excluded submitting these patients to a maximal effort ECG on an ergometer. The normal subjects were comparable to diabetic patients for age, sex, mean arterial pressure, body mass index and body surface area. At rest, stroke volume, peak filling rate, cardiac output, ejection fraction (EF), were significantly lower in diabetic patients than in normal subjects. Systemic vascular resistances (SVR) were higher in diabetics than in normal subjects (p less than 0.01). Mean EF during effort increased in both normals and diabetics but 30% of diabetic patients showed no increase in EF during effort (less than 5%). Preload, represented by end-diastolic volume or blood volume, did not differ in the 2 groups.(ABSTRACT TRUNCATED AT 250 WORDS)