Many scenarios of physics beyond the standard model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional ...scalars with masses in the MeV to GeV range could be significantly weakened if they interact predominantly with leptons rather than quarks. At an e+e− collider, such a leptophilic scalar (ϕL) would be produced predominantly through radiation from a τ lepton. We report herein a search for e+e−→τ+τ−ϕL, ϕL→ℓ+ℓ− (ℓ=e, μ) using data collected by the BABAR experiment at SLAC. No significant signal is observed, and we set limits on the ϕL coupling to leptons in the range 0.04<mϕL<7.0 GeV. These bounds significantly improve upon the current constraints, excluding almost entirely the parameter space favored by the observed discrepancy in the muon anomalous magnetic moment below 4 GeV at 90% confidence level.
This paper presents the results of an analysis of observations of the Crab Nebula gamma-ray source with the first two atmospheric Cherenkov telescopes of the TAIGA (Tunka Advanced Instrument for ...cosmic ray physics and Gamma Astronomy) astrophysical complex in the stereo mode of observations. The article analyzed observational data from 2020 to 2021. Over 36 hours of observations, a signal was obtained at a statistical significance level of 5
and a spectrum of gamma rays was plotted in the energy range from 2 to 70 TeV. The paper describes a technique for gamma–hadron separation and reconstruction of detected gamma-rays energy.
We studied changes in the bone tissue in patients with diffuse large B-cell lymphoma at the onset of the disease (
N
=41; before chemotherapy) and 5-16 years after the end of treatment (
N
=47). ...Osteodensitometry, biochemical markers of osteoporosis in the blood and urine, and gene expression in multipotent mesenchymal stromal cells were analyzed. In multipotent mesenchymal stromal cells of all patients, the expression of genes associated with bone and cartilage differentiation (
FGF2
,
FGFR1
,
FGFR2
,
BGLAP
,
SPP1
,
TGFB1
, and
SOX9
) was changed. In primary patients, the ratio of deoxypyridinoline/creatinine in the urine and blood level of β-cross-laps were increased, while plasma concentration of vitamin D was reduced, which indicates activation of bone resorption. No differences between the groups were revealed by osteodensitometry. No direct relationship between changes in gene expression in multipotent mesenchymal stromal cells and osteoporosis markers was found. The presence of a tumor in the body affects the bone marrow stroma, but achievement of remission and compensatory mechanisms provide age-appropriate condition of the bone tissue.
We study the processes e+e- → π+π-π0π0π0π0γ and π+π-π0π0π0ηγ in which an energetic photon is radiated from the initial state. The data were collected with the BABAR detector at the SLAC National ...Accelerator Laboratory. About 7300 and 870 events, respectively, are selected from a data sample corresponding to an integrated luminosity of 469 fb-1 . The invariant mass of the hadronic final state defines the effective e+e- center-of-mass energy. The center-of-mass energies range from threshold to 4.5 GeV. From the mass spectra, the first ever measurements of the e+e- → π+π-π0π0π0π0 and the e+e- → π+π-π0π0π0η cross sections are performed. The contributions from ωπ0π0π0 , ηπ+π-π0 , ωη , and other intermediate states are presented. We observe the J/ψ and ψ ( 2S ) in most of these final states and measure the corresponding branching fractions, many of them for the first time.
—The results of studying the technology of layer-by-layer deposition of products made of ABS and PLA plastics are presented. The influence of various technological parameters (type of application of ...layers, direction of laying and thickness of threads, printing speed) on the mechanical characteristics of products (strength, plasticity, anisotropy of properties) and the material (specimen) density is studied. Recommendations on the development of this process are given.
The article surveys the first
35
Cl NQR results on detecting and characterizing noncovalent interactions in systems assembling B
10
Cl
10
2−
clusters via halogen atoms. A number of compounds of ...decachloro-
closo
-decaborates with alkali metal or organic cations as well as with silver(I), copper(II) and iron(II) complexes were studied using
35
Cl NQR and X-ray diffraction. The main interest of this survey is a capability of chlorine atoms to participate in noncovalent interactions with organic cations, ligand and solvent molecules without touching upon issues of synthesis. Whereas X-ray diffraction establishes the noncovalent interactions relying on the sum of vdW radii which serves as the basic and sometimes the only experimental criterion for identifying such interactions, the
35
Cl NQR technique registers subtle perturbations in electron density distribution on the chlorine site caused by secondary interactions Cl···X. They adequately split the
35
Cl NQR spectra thus selecting from the entire set of interatomic contacts those actually induced by noncovalent interactions.
Cancer stem cells (CSCs) are the most malignant subpopulation of tumor cells that possess a tumorigenic potential and resistantance to chemotherapy. These properties make CSCs a promising target for ...the development of targeted antitumor therapy which is especially in demand in highly aggressive cancers. However, the correct identification of cancer cells with stem properties remains a challenge. A newly developed lentivirus-based reporter SORE6 allows to directly identify CSCs by measuring gene expression of the embryonic stem cell factors SOX2 and OCT4. In the current study the reporter was modified to enable isolation of SOX2
+
/OCT4
+
cells by immunomagnetic separation and then was used to transduce HCC1806 and MDA-MB-453 triple-negative breast cancer (TNBC) cell lines. To validate the modified reporter, SOX2
+
/OCT4
+
populations were isolated and analyzed for the content of NANOG, a key transcription factor of pluropotency which expression is regulated by SOX2/OCT4. The percentage of SOX2
+
/OCT4
+
cells was assessed for each cell line. An increased content of NANOG protein was found in isolated SOX2
+
/OCT4
+
cell fractions indicating that the modified reporter is suitable for further studying the CSC subset.
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