OPERA tau neutrino charged current interactions

The OPERA experiment was designed to discover the vτ appearance in a vμ beam, due to neutrino oscillations. The detector, located in the underground Gran Sasso Laboratory, consisted of a nuclear photographic emulsion/lead target with a mass of about 1.25 kt, complemented by electronic detectors. It was exposed from 2008 to 2012 to the CNGS beam: an almost pure vμ beam with a baseline of 730 km, collecting a total of 1.8·1020 protons on target. The OPERA Collaboration eventually assessed the discovery of vμ→vτ oscillations with a statistical significance of 6.1 σ by observing ten vτ CC interaction candidates. These events have been published on the Open Data Portal at CERN. This paper provides a detailed description of the vτ data sample to make it usable by the whole community.

Final Results of the OPERA Experiment on ν_{τ} Appearance in the CNGS Neutrino Beam

The OPERA experiment was designed to study ν_{μ}→ν_{τ} oscillations in the appearance mode in the CERN to Gran Sasso Neutrino beam (CNGS). In this Letter, we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to 17.97×10^{19} protons on target. Selection criteria looser than in previous analyses have produced ten ν_{τ} candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of ν_{τ} properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of ν_{τ} appearance is confirmed with an improved significance level of 6.1σ. |Δm_{32}^{2}| has been measured, in appearance mode, with an accuracy of 20%. The measurement of the ν_{τ} charged-current cross section, for the first time with a negligible contamination from ν[over ¯]_{τ}, and the first direct evidence for the ν_{τ} lepton number are also reported.

Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment

The OPERA experiment was designed to search for ν_{μ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{μ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{μ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.

Synthesis and anti-HIV-1 activity of new delavirdine analogues carrying arylpyrrole moieties

In our search for novel anti-human immunodeficiency virus (HIV)-1 agents, 14 delavirdine analogues were synthesized and evaluated as potential anti-HIV-1 agents in cell-based assays. Compound 1Aa exhibited potent and selective anti-HIV-1 activity in acutely infected MT4 cells, with effective concentration (EC50) values in the submicromolar range.

Neuronal antioxidant system and MPTP-induced oxidative stress in the striatum and brain stem of the rat

Levels of ascorbic acid (AA), dehydroascorbic acid (DHAA), glutathione (GSH), uric acid, dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxytyramine (3-MT), noradrenaline (NA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and 1-methyl-4-phenylpyridinium ion (MPP+) were determined in the striatum, striatal synaptosomes, and/or brain stem of 3- and 6-month-old male Wistar rats given MPTP 35-52 mg/kg IP. In older rats, MPTP 35 mg/kg caused a 38% death rate within 15 min-12 h. Levels of MPTP and MPP+ in the striatum, synaptosomes, and brain stem were directly correlated with the absolute MPTP dose/rat. MPTP decreased striatal DA metabolites and NA levels in the striatum and brain stem, and increased uric acid levels in all regions in all rats. All these changes were significantly correlated with MPP+ levels. GSH levels were increased in younger rats and decreased in older rats. AA oxidation was increased mainly in older rats. We conclude that acute lethality and regional brain MPTP and MPP+ levels depend upon the absolute dose of MPTP/rat rather than the relative dose/kg. In younger rats, the neuronal antioxidant GSH system is more efficient than in older rats, in which the response to MPP(+)-induced oxidative stress also involves AA oxidation. The increase in uric acid levels provides further evidence for a mechanism of MPTP neurotoxicity involving oxidative stress mediated by xanthine oxidase.

Effects of ageing on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxic effects on striatum and brainstem in the rat

In 3- and 18-month-old male Wistar rats, levels of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), ascorbic acid (AA), dehydroascorbic acid (DHAA), noradrenaline (NA), uric acid, glutathione (GSH) and 1-methyl-4-phenylpyridinium ion (MPP+) were determined by HPLC in the striatum and/or in the brainstem 24 h after single injections of MPTP (12-35 mg/kg i.p.). Aged rats had lower baseline levels of AA and GSH, compared to young rats. In aged rats, MPTP 35 mg/kg induced a 70% death rate and a decrease in striatal DOPAC/DA ratio which was significantly correlated to MPP+ concentrations (r = -0.840, P < 0.005); in addition, MPTP did not increase AA oxidation. In the brainstem, the MPTP-induced decrease in NA levels and increase in uric acid levels were significantly correlated to the MPP+ concentrations (r = -0.709, P < 0.05, and r = +0.888, P < 0.001, respectively). In conclusion, evidence is given of a mechanism of toxicity of MPTP involving oxidative stress produced by xanthine oxidase; in addition, in aged rats the neuronal antioxidant system (levels of AA and GSH) is considerably lower than in young rats and may play an enabling role in the MPTP age-related neurotoxic effects on striatum and brainstem.

[Synthesis and choleretic activity of 3-(2-aryl-5R-benzimidazol-1-yl) butanoic acids]

Thirty 3-(2-aryl-5R-benzimidazol-1-yl)butanoic acids were prepared in order to evaluate substitution effects on the 2 and 5 positions of the heterocyclic ring upon the previously recorded choleretic activity of 3-(2-phenylbenzimidazol-1-yl)butanoic acid. A general choleretic activity is shown by the acids tested, which in several cases it is superior to that of the model compound and sometimes also to that of dehydrocholic acid.

6-Halogen derivatives of 2-(3-benzoylphenyl)propionic acid

The synthesis of the 6-fluoro (I a), 6-chloro (I b) and 6-bromo (I c) derivatives of the known antiinflammatory agent 2-(3-benzoylphenyl)propionic acid (ketoprofen) is reported. The procedure employed involves the direct phase-transfer methylation of the appropriate arylacetonitriles and the subsequent hydrolysis of the alpha-methyl arylacetonitriles (V) thus obtained. It is noteworthy that (V b) and (V c) were not accompanied by alpha, alpha-dimethylated contaminants, owing to the steric hindrance of the chloro and bromine substituent. The pharmacological evaluation of (I a-c) showed that the presence of the halogen unexpectedly abolished the antiinflammatory and antipyretic activities of the model drug. The 6-ethoxy derivative (I d), isolated as by-product of the synthesis of (I a) was also found inactive. A hypothesis has been formulated on the loss of activity of these compounds.

[Unexpected anti-inflammatory activity of rigid structure derivatives of 6-arylpyridazinone antihypertensives. I. Synthesis and activity of 4,4a-dihydro-5H-indeno[1,2c]pyridazin-3-ones]

The antihypertensive 5-methyl-6-p.cyanophenyl-4,5-dihydro-3(2H)-pyridazinone has been embodied in a rigid framework corresponding to a 4,4a-dihydro-5H-indeno[1,2-c]-3-pyridazinonic structure (II). The resulting 7-cyano derivative (IIc) was found to be devoid of antihypertensive activity. However this compound, as well as other members having structure (II), exhibited antiinflammatory properties.