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.
Measurements of the atmospheric flux of muons and other charged particles have been performed at the external site of the Gran Sasso Laboratory (LNGS, Italy,
1000
m
a.s.l.
), in view of the OPERA ...experiment. Scintillation counters and nuclear emulsion plates have been used. Rates and angular distributions at several depths of Fe shielding are presented and compared with Monte Carlo simulations.
Designed as a new series of so called “bivalent ligand” containing the proposed 2-benzylnaphthimidazole-type structure, a number of 2-benzylnaphth2,3-
dimidazoles, bearing various substituents, have ...been prepared by a synthetic approach involving an heterocyclization of 2,3-diaminonaphthalene
4 with appropriate imidates
3 (for
1b–
i) followed by alkylation (for
1j–
l) with the desired alkylating agent. Compounds
1b–
f,
h–
l were subjected to primary biological evaluation for cancer cell growth inhibition (one-dose, three-cell assay), and the four most active terms,
1c,
h,
i and
j, were then evaluated for their cytotoxic profiles in the National Cancer Institute’s (NCI) human disease-oriented, 60 cell line, in vitro antitumor screening protocol. Among them, two compounds (
1h and
1i) are the most representatives demonstrating not only high growth-inhibitory activities against some leukemia cancer cells, but also fairly good activities against the growth of certain cell lines of some solid tumors.
The Protvino accelerator facility located in the Moscow region, Russia, is in a good position to offer a rich experimental research program in the field of neutrino physics. Of particular interest is ...the possibility to direct a neutrino beam from Protvino towards the KM3NeT/ORCA detector, which is currently under construction in the Mediterranean Sea 40 km offshore Toulon, France. This proposal is known as P2O. Thanks to its baseline of 2595 km, this experiment would yield an unparalleled sensitivity to matter effects in the Earth, allowing for the determination of the neutrino mass ordering with a high level of certainty after only a few years of running at a modest beam intensity of
≈
90
kW
. With a prolonged exposure (
≈
1500
kW
year
), a
2
σ
sensitivity to the leptonic CP-violating Dirac phase can be achieved. A second stage of the experiment, comprising a further intensity upgrade of the accelerator complex and a densified version of the ORCA detector (Super-ORCA), would allow for up to a
6
σ
sensitivity to CP violation and a
10
∘
-
17
∘
resolution on the CP phase after 10 years of running with a 450 kW beam, competitive with other planned experiments. The initial composition and energy spectrum of the neutrino beam would need to be monitored by a near detector, to be constructed several hundred meters downstream from the proton beam target. The same neutrino beam and near detector set-up would also allow for neutrino-nucleus cross section measurements to be performed. A short-baseline sterile neutrino search experiment would also be possible.
The KM3NeT research infrastructure is under construction in the Mediterranean Sea. It consists of two water Cherenkov neutrino detectors, ARCA and ORCA, aimed at neutrino astrophysics and oscillation ...research, respectively. Instrumenting a large volume of sea water with Formula omitted optical modules comprising a total of Formula omitted photomultiplier tubes, KM3NeT will achieve sensitivity to Formula omitted neutrinos from Galactic and near-Galactic core-collapse supernovae through the observation of coincident hits in photomultipliers above the background. In this paper, the sensitivity of KM3NeT to a supernova explosion is estimated from detailed analyses of background data from the first KM3NeT detection units and simulations of the neutrino signal. The KM3NeT observational horizon (for a Formula omitted discovery) covers essentially the Milky-Way and for the most optimistic model, extends to the Small Magellanic Cloud ( Formula omitted). Detailed studies of the time profile of the neutrino signal allow assessment of the KM3NeT capability to determine the arrival time of the neutrino burst with a few milliseconds precision for sources up to 5-8 kpc away, and detecting the peculiar signature of the standing accretion shock instability if the core-collapse supernova explosion happens closer than 3-5 kpc, depending on the progenitor mass. KM3NeT's capability to measure the neutrino flux spectral parameters is also presented.
The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deep waters of the Mediterranean Sea. This digital optical module has a novel design ...with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same
40
K decay and the localisation of bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions.
The OPERA experiment is searching for nu_mu -> nu_tau oscillations in appearance mode i.e. via the direct detection of tau leptons in nu_tau charged current interactions. The evidence of nu_mu -> ...nu_tau appearance has been previously reported with three nu_tau candidate events using a sub-sample of data from the 2008-2012 runs. We report here a fourth nu_tau candidate event, with the tau decaying into a hadron, found after adding the 2012 run events without any muon in the final state to the data sample. Given the number of analysed events and the low background, nu_mu -> nu_tau oscillations are established with a significance of 4.2sigma.
The KM3NeT Collaboration is currently constructing a multi-site high-energy neutrino telescope in the Mediterranean Sea consisting of matrices of pressure-resistant glass spheres, each holding a set ...of 31 small-area photomultipliers. The main goals of the telescope are the observation of neutrino sources in the Universe and the measurement of the neutrino oscillation parameters with atmospheric neutrinos. A relative time synchronisation between photomultipliers of the nanosecond order needed to guarantee the required angular resolution of the detector. Due to the large detector volumes to be instrumented by KM3NeT, a cost reduction of the different systems is a priority. To this end, the inexpensive Nanobeacon has been designed and developed by the KM3NeT Collaboration to be used for detector time-calibration studies. At present, more than 600 Nanobeacons have been already produced. The characterisation of the optical pulse and the wavelength emission profile of the devices is critical for the time calibration. The optical pulse rise time has been quantified as less than 3 ns, while the Full Width Half Maximum is less than 6 ns. The wavelength drift, due to a variation of the supply voltage, has also been qualified as lower than 10 nm for the full range of the Nanobeacon. In this paper, more details about the main features of the Nanobeacon design, production and operation, together with the main properties of the light pulse generated are described.
In this paper a search for associated charm production both in neutral and charged current ν-nucleus interactions is presented. The improvement of automatic scanning systems in the CHORUS experiment ...allows an efficient search to be performed in emulsion for short-lived particles. Hence a search for rare processes, like the associated charm production, becomes possible through the observation of the double charm-decay topology with a very low background. About 130000 ν interactions located in the emulsion target have been analysed. Three events with two charm decays have been observed in the neutral-current sample with an estimated background of 0.18±0.05. The relative rate of the associated charm cross-section in deep inelastic ν interactions, σ(cc̄ν)/σNCDIS=(3.62+2.95-2.42(stat)±0.54(syst))×10-3 has been measured. One event with two charm decays has been observed in charged-current νμ interactions with an estimated background of 0.18±0.06 and the upper limit on associated charm production in charged-current interactions at 90% C.L. has been found to be σ(cc̄μ-)/σCC<9.69×10-4.
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