We present a high-accuracy calculation of the deuteron structure radius in chiral effective field theory. Our analysis employs the state-of-the-art semilocal two-nucleon potentials and takes into ...account two-body contributions to the charge density operators up to fifth order in the chiral expansion. The strength of the fifth-order short-range two-body contribution to the charge density operator is adjusted to the experimental data on the deuteron charge form factor. A detailed error analysis is performed by propagating the statistical uncertainties of the low-energy constants entering the two-nucleon potentials and by estimating errors from the truncation of the chiral expansion as well as from uncertainties in the nucleon form factors. Using the predicted value for the deuteron structure radius together with the very accurate atomic data for the difference of the deuteron and proton charge radii we, for the first time, extract the charge radius of the neutron from light nuclei. The extracted value reads r_{n}^{2}=-0.106_{-0.005}^{+0.007} fm^{2} and its magnitude is about 1.7σ smaller than the current value given by the Particle Data Group. In addition, given the high accuracy of the calculated deuteron charge form factor and its careful and systematic error analysis, our results open the way for an accurate determination of the nucleon form factors from elastic electron-deuteron scattering data measured at the Mainz Microtron and other experimental facilities.
In a recent paper Phys. Rev. D 98, 074023 (2018), the most up-to-date experimental data for all measured production and decay channels of the bottomoniumlike states Zb(10610) and Zb(10650) were ...analyzed in a field-theoretical coupled-channel approach which respects analyticity and unitarity and incorporates both the pion exchange and a short-ranged potential nonperturbatively. All parameters of the interaction were fixed directly from data, and pole positions for both Zb states were determined. In this work we employ the same approach to predict in a parameter-free way the pole positions and the line shapes in the elastic and inelastic channels of the (still to be discovered) spin partners of the Zb states. They are conventionally referred to as WbJ's with the quantum numbers JPC = J++ (J = 0, 1, 2). It is demonstrated that the results of our most advanced pionful fit, which gives the best χ2/d.o.f. for the data in the Zb channels, are consistent with all WbJ states being above-threshold resonances which manifest themselves as well-pronounced hump structures in the line shapes. On the contrary, in the pionless approach, all WbJ's are virtual states which can be seen as enhanced threshold cusps in the inelastic line shapes. Since the two above scenarios provide different imprints on the observables, the role of the one-pion exchange in the B(*)B¯(*) systems can be inferred from the once available experimental data directly.
In the present paper, we investigate the structure of the metric space
M
of compact metric spaces considered up to an isometry and endowed with the Gromov–Hausdorff metric in a neighborhood of a ...finite metric space, whose isometry group is trivial. It is shown that a sufficiently small ball in the subspace of
M
consisting of finite spaces with the same number of points centered at such a space is isometric to a corresponding ball in the space ℝ
N
endowed with the norm
|
(
x
1
, . . . , x
N
)
|
=
max
i
x
i
. Also an isometric embedding of a finite metric space into a neighborhood of a finite asymmetric space in
M
is constructed.
The features of distribution and catch in the Barents Sea of the golden redfish
Sebastes norwegicus
associated with changes in its size composition have been considered. It has been shown that ...juveniles and immature individuals are found in this region in a larger water area than medium-sized and large fish. The factor limiting the distance of migrations of adult golden redfish from the areas of spawning and wintering to the Barents Sea is the depth of the sea, while as the fish grow, the influence of this factor increases. Increase of young fish in the golden redfish stock due to replenishment with high-yielding generations in 2003, 2008 and 2009 contributed to an increase in the spatial and temporal overlap of its range with fishing areas of groundfish, which was reflected in the size of its by-catch. Growth in catches of golden redfish in 2016–2020 in the Barents Sea was primarily due to the expansion of the water area of its distribution. The number and total duration of commercial trawls in the Barents Sea, in the catches of which golden redfish were found, in 2016–2020 increased sharply, however, the productivity of fishing in these years did not change significantly and did not correlate with the increase in catch.
The aim of the study was the assessment of the neuroprotective potential of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline (DHQ) and its effect on inflammation, apoptosis, and transcriptional ...regulation of the antioxidant system in cerebral ischemia/reperfusion (CIR) in rats.
The CIR rat model was constructed using the bilateral common carotid artery occlusion followed by reoxygenation. DHQ was administered at a dose of 50 mg/kg for three days. Histological staining was performed using hematoxylin and eosin. The level of S100B protein, 8-hydroxy-2-deoxyguanosine, and 8-isoprostane was assessed using an enzyme immunoassay. The intensity of apoptosis was assessed based on the activity of caspases and DNA fragmentation. The activity of enzymes was measured spectrophotometrically, the level of gene transcripts was assessed by real-time PCR.
DHQ reduced the histopathological changes and normalized levels of S100B, lactate, pyruvate, and HIF-1 mRNA in the CIR rat model. In addition, DHQ decreased the oxidative stress markers in animals with a pathology. The tested compound also inhibited inflammation by decreasing the activity of myeloperoxidase, expression of interleukins and Nfkb2. DHQ-treated rats with CIR showed decreased caspase activity, DNA fragmentation, and AIF expression. DHQ changed activity of antioxidant enzymes to the control values, decreased the expression of Cat, Gsr, and Nfe2l2, which was overexpressed in CIR, and activated the expression of Sod1, Gpx1, Gsta2, and Foxo1.
DHQ showed a neuroprotective effect on CIR in rats. The neuroprotective effect involve mechanisms such as the inhibition of oxidative stress, leading to a reduction in the inflammatory response and apoptosis and the modulation of the antioxidant defense components.
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•DHQ is a potent inhibitor of oxidative stress in cerebral ischemia/reperfusion.•DHQ has a neuroprotective effect due to its anti-inflammatory and anti-apoptotic action.•DHQ regulates antioxidant enzymes via Nfe2l2 and Foxo1 expression.
There is still insufficient knowledge with regard to the potential involvement of mast cells (MCs) and their mediators in the pathology of coronavirus disease-2019 (COVID-19). Therefore, our study ...aimed to investigate the role of MCs, their activation and protease profiles in the pathogenesis of early and late lung damage in COVID-19 patients.
Formalin-fixed and paraffin embedded lung specimens from 30 patients who died from COVID-19 and 9 controls were used for histological detection of MCs and their proteases (tryptase, chymase) followed by morphometric quantification.
Our results demonstrated increased numbers of MCs at early stage and further augmentation of MCs number during the late stage of alveolar damage in COVID-19 patients, as compared to the control group. Importantly, the percentage of degranulated (activated) MCs was higher during both stages of alveolar lesions in comparison to the controls. While there was no prominent alteration in the profile of tryptase-positive MCs, our data revealed a significant elevation in the number of chymase-positive MCs in the lungs of COVID-19 patients, compared to the controls.
MCs are characterized by dysregulated accumulation and increased activation in the lungs of patients suffering from COVID-19. However, future profound studies are needed for precise analysis of the role of these immune cells in the context of novel coronavirus disease.
The research group of the Arctic Museum and Exhibition Center, Peter the Great Museum of An-thropology and Ethnography, in cooperation with the Marine Heritage Association and the media group of the ...Marine Technical College in St. Petersburg are implementing the Arctic Oral Memory project, supported by the Presidential Grants Fund. The project involves the creation of an open Internet resource https://arcticmemory.ru/ with video recordings of oral histories of famous Russian polar explorers. The article is devoted to the results and experience of the implementation of this project, which is at the intersection of journalism (popularization), cultural anthropology and history, providing the opportunity to see and hear first-hand information from those who personally participated in the study and development Arctic.
The most recent experimental data for all measured production and decay channels of the bottomoniumlike states Zb(10610) and Zb(10650) are analyzed simultaneously using solutions of the ...Lippmann-Schwinger equations which respect constraints from unitarity and analyticity. The interaction potential in the open-bottom channels B(*)B¯*+c.c. contains short-range interactions as well as a one-pion exchange. It is found that the long-range interaction does not affect the line shapes as long as only S waves are considered. Meanwhile, the line shapes can be visibly modified once D waves, mediated by the strong tensor forces from the pion exchange potentials, are included. However, in the fit they get balanced largely by a momentum dependent contact term that appears to be needed also to render the results for the line shapes independent of the cutoff. The resulting line shapes are found to be insensitive to various higher-order interactions included to verify stability of the results. Both Zb states are found to be described by the poles located on the unphysical Riemann sheets in the vicinity of the corresponding thresholds. In particular, the Zb(10610) state is associated with a virtual state residing just below the BB¯*/B¯B* threshold while the Zb(10650) state most likely is a shallow state located just above the B*B¯* threshold.
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