ABSTRACT
The existence of high-energy astrophysical neutrinos has been unambiguously demonstrated, but their sources remain elusive. IceCube reported an association of a 290-TeV neutrino with a ...gamma-ray flare of TXS 0506 + 056, an active galactic nucleus with a compact radio jet pointing to us. Later, radio-bright blazars were shown to be associated with IceCube neutrino events with high statistical significance. These associations remained unconfirmed with the data of independent experiments. Here, we report on the detection of a rare neutrino event with the estimated energy of 224 ± 75 TeV from the direction of TXS 0506 + 056 by the new Baikal Gigaton Volume Detector (Baikal-GVD) in April 2021. This event is the highest energy cascade detected so far by the Baikal-GVD neutrino telescope from a direction below horizon. The result supports previous suggestions that radio blazars in general, and TXS 0506 + 056 in particular, are the sources of high-energy neutrinos, and opens up the cascade channel for the neutrino astronomy.
Biomarkers predicting treatment response may be used to stratify patients with pancreatic ductal adenocarcinoma (PDAC) for available therapies. The aim of this study was to evaluate the association ...of circulating cytokines with FOLFIRINOX response and with overall survival (OS).
Serum samples were collected before start and after the first cycle of FOLFIRINOX from patients with PDAC (
=83) of all disease stages. Overall, 34 circulating cytokines were analyzed with a multiplex immunoassay. In addition, changes in peripheral blood immune cell counts were determined by flow cytometry to correlate with differences in cytokine levels. Chemotherapy response was determined by CT scans with the RECIST 1.1 criteria, as disease control (
=64) or progressive disease (
=19) within eight cycles of FOLFIRINOX.
Patients with high serum IL-1RA concentrations after one cycle of chemotherapy were less likely to have tumor progression during FOLFIRINOX (OR 0.25,
=0.040). Increase of circulating IL-1RA concentrations correlated with increase of total, classical (CD14+CD16-), and non-classical monocytes (CD14-CD16+), and dendritic cells. In multivariable cox regression, including the variables chemotherapy response outcome and baseline CA19-9 level, serum concentrations of IL-7 (HR 2.14,
=0.010), IL-18 (HR 2.00,
=0.020), and MIP-1β (HR 0.51,
=0.025) after one cycle of FOLFIRINOX showed correlations with OS.
Circulating IL-1RA, IL-7, IL-18, and MIP-1β concentrations are biomarkers associated with FOLFIRINOX response in PDAC patients, suggesting an important role for specific immune cells in chemotherapy response and PDAC progression. Cytokine-based treatment might improve patient outcome and should be evaluated in future studies.
This contribution describes improvements to the Baikal-GVD alert system related to alert visualization which could clarify the alert data and its possible relation to astrophysical phenomena. The ...Baikal-GVD online data processing and alert system was launched at the beginning of 2021. It is designed for fast online neutrino event reconstruction and, when a potential signal from an astrophysical source is detected, sending an alert message to collaboration members. It also searches for coincidences between internal alerts and other astrophysical experiment alerts. The databases schema used to store the alert data (MariaDB, InfluxDB, MongoDB) is described. Automation of data analysis and visualization processes occurs using specialized Python libraries (Matplotlib, Astropy, etc.), which provide an API for that. The capabilities of the Grafana software system for storing visualized data with the ability to share are also explored. One of the main tasks of our alert system is switch to real-time mode with a low latency mode in signal reception both by the Baikal-GVD trigger and in receiving and responding to an external alert.
Modern astronomy aims to study the astrophysical objects with the various types of signals incoming from them. To achieve the goals of the multi-messenger astronomy, experiments should exchange data, ...that can be done with the alert messages. Alert contains essential information about the detected event. These messages are distributed via international networks facilitating the rapid follow-up of transient astrophysical phenomena. The Baikal-GVD alert system receives external alerts and applies different methods to search for signal coincidences. For better understanding of the alert system workflow and researching of the astrophysical neutrino sources the alert visualization is necessary. This work deals with the techniques that are used within the coincidence search process and the visualization of the alerts: Baikal-GVD alerts and external messages from experiments like the IceCube neutrino telescope, Fermi gamma-ray telescope and LIGO/Virgo/KAGRA gravitational observatories.
The neutrino telescope Baikal-GVD is designed for search for high energy neutrinos whose sources are not yet reliably identified. It currently includes total of 3456 optical modules arranged on 96 ...strings, providing an effective volume of 0.6 km
for cascades with energy above 1 PeV. We discuss the first results from the partially built experiment, which is currently the largest neutrino telescope in the Northern Hemisphere and still growing up.
Currently, the Baikal-GVD Deep Underwater Neutrino Telescope is being successfully deployed in Lake Baikal. It comprises 96 strings with 3456 optical modules. We present the status and plans for ...further deployment of the Baikal-GVD telescope and discuss the issues related to the development of the next-generation neutrino telescope in Lake Baikal.
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Deployment of the deep-sea neutrino telescope Baikal-GVD continues in Lake Baikal. By April 2022, ten telescope clusters, which include 2880 optical modules, were put into operation. One of the ...urgent tasks of the Baikal project is to study the possibility of increasing the detection efficiency of the detector based on the experience of its operation and the results obtained with other neutrino telescopes in recent years. In this paper, the authors consider a variant of optimizing the telescope configuration by installing an additional string of optical modules between the detector clusters (external string). An experimental version of the external garland was installed in Lake Baikal in April 2022. The paper presents the results from calculations of the efficiency of registration of neutrino events for a new setup configuration, the technical implementation of the system for recording and collecting data from the external garland, and the first results of its full-scale tests in Lake Baikal.
The status of the Baikal-GVD neutrino telescope under construction and its main scientific results are presented. The detector consists of 2916 optical sensors located at 81 vertical strings deep ...below the surface of Lake Baikal. Its geometric configuration is optimized for detecting neutrinos with energies above 100 TeV. Events from muon neutrinos were identified, the flux of which is consistent with the expectation for the flux of atmospheric neutrinos. The data obtained during the alerts of the ANTARES and IceCube telescopes were analyzed. Candidate events for high-energy neutrinos of astrophysical origin have been obtained.
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•NiW/Y-ASA-Al2O3 catalysts were prepared, studied using physical-chemical techniques and tested in second stage hydrocracking.•The higher the zeolite content the higher the activity ...of the catalyst and the concentration of Brønsted acid sites are.•Increase of zeolite content leads to decrease of selectivity to diesel.•Increase of nitrogen content in feed results in a drop of catalyst activity and in almost no change of selectivity to diesel.
NiW catalysts for second stage hydrocracking were prepared by impregnation of granulated supports with ultrastable zeolite Y content of 5−30 wt%; amorphous silica-alumina content of 45−20 wt%; and γ-Al2O3 content of 50 wt%. The catalysts were studied by low-temperature N2 adsorption, HRTEM, XPS and IR spectroscopy of adsorbed pyridine. Sulfide NiWS particles have been revealed to be similar in all the catalysts according to HRTEM and XPS. It has been shown that concentration of Brønsted acid sites increases with increasing of zeolite content in the catalysts. Hydrocracking tests were carried out at a pressure of 16.0 MPa, a LHSV of 1.4 h−1 and H2 to oil ratio of 750 (v/v). Two samples of unconverted oil with nitrogen content of 11 and 65 ppm obtained from the products of VGO hydrocracking under different severities were used as the feedstocks. The higher zeolite content the higher activity of the catalyst was achieved. However, the increase of zeolite content leaded to the decrease of selectivity to diesel. It has been found that increasing of nitrogen content in the feedstock was followed by a sharp decline in catalyst activity while the change in selectivity to diesel was insignificant. Optimal zeolite content in the support for studied conditions and feedstock with nitrogen content of 65 ppm was 20 wt%.
Baikal-GVD is a 1 km
3
scale neutrino telescope now under construction in Lake Baikal. The sensitive volume of the detector is currently around 0.5 km
3
. Muons form through the exchange of W-bosons ...in the interaction between muon- and partial tau-neutrinos near the telescope. The muons then propagate to great distances in the lake’s water. Reconstructing their trajectory allows us to obtain the most accurate estimate of the direction of neutrinos at telescopes of this type. Angular resolution can be as good as 0.5° for fairly long muon tracks. The current state of affairs in analyzing track events at the Baikal-GVD is discussed.
