385 research outputs found
Ground-based station network in Arctic and Subarctic Eurasia : an overview
The international Pan-Eurasian Experiment (PEEX) program addresses the full spectrum of problems related to climate change in Eurasian Northern latitudes. All PEEX activities rely on the bulk of high-quality observational data provided by the ground and marine stations, remote sensing and satellite tools. So far, no coordinated station network has ever existed in Eurasia, moreover, the current scope of relevant research remains largely unknown as no prior assessment has been done to date. This paper makes the first attempt to overview the existing ground station pool in the Arctic-Boreal region with the focus on Russia. The geographical, climatic and ecosystem representativeness of the current stations is discussed, the gaps are identified and tentative station network developments are proposed.Peer reviewe
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
Angiogenic and pleiotropic effects of VEGF165 and HGF combined gene therapy in a rat model of myocardial infarction
<div><p>Since development of plasmid gene therapy for therapeutic angiogenesis by J. Isner this approach was an attractive option for ischemic diseases affecting large cohorts of patients. However, first placebo-controlled clinical trials showed its limited efficacy questioning further advance to practice. Thus, combined methods using delivery of several angiogenic factors got into spotlight as a way to improve outcomes. This study provides experimental proof of concept for a combined approach using simultaneous delivery of VEGF165 and HGF genes to alleviate consequences of myocardial infarction (MI). However, recent studies suggested that angiogenic growth factors have pleiotropic effects that may contribute to outcome so we expanded focus of our work to investigate potential mechanisms underlying action of VEGF165, HGF and their combination in MI. Briefly, Wistar rats underwent coronary artery ligation followed by injection of plasmid bearing VEGF165 or HGF or mixture of these. Histological assessment showed decreased size of post-MI fibrosis in bothâVEGF165- or HGF-treated animals yet most prominent reduction of collagen deposition was observed in VEGF165+HGF group. Combined delivery group rats were the only to show significant increase of left ventricle (LV) wall thickness. We also found dilatation index improved in HGF or VEGF165+HGF treated animals. These effects were partially supported by our findings of c-kit+ cardiac stem cell number increase in all treated animals compared to negative control. Sporadic Ki-67+ mature cardiomyocytes were found in peri-infarct area throughout study groups with comparable effects of VEGF165, HGF and their combination. Assessment of vascular density in peri-infarct area showed efficacy of bothâVEGF165 and HGF while combination of growth factors showed maximum increase of CD31+ capillary density. To our surprise arteriogenic response was limited in HGF-treated animals while VEGF165 showed potent positive influence on a-SMA+ blood vessel density. The latter hinted to evaluate infiltration of monocytes as they are known to modulate arteriogenic response in myocardium. We found that monocyte infiltration was driven by VEGF165 and reduced by HGF resulting in alleviation of VEGF-stimulated monocyte taxis after combined delivery of these 2 factors. Changes of monocyte infiltration were concordant with a-SMA+ arteriole density so we tested influence of VEGF165 or HGF on endothelial cells (EC) that mediate angiogenesis and inflammatory response. In a series of <i>in vitro</i> experiments we found that VEGF165 and HGF regulate production of inflammatory chemokines by human EC. In particular MCP-1 levels changed after treatment by recombinant VEGF, HGF or their combination and were concordant with NF-ÎșB activation and monocyte infiltration in corresponding groups <i>in vivo</i>. We also found that bothâVEGF165 and HGF upregulated IL-8 production by EC while their combination showed additive type of response reaching peak values. These changes were HIF-2 dependent and siRNA-mediated knockdown of HIF-2α abolished effects of VEGF165 and HGF on IL-8 production. To conclude, our study supports combined gene therapy by VEGF165 and HGF to treat MI and highlights neglected role of pleiotropic effects of angiogenic growth factors that may define efficacy via regulation of inflammatory response and endothelial function.</p></div
Effects of human VEGF165 and HGF on IL-8 and MCP-1 production by endothelial cells <i>in vitro</i>.
<p>AâMCP-1 production by HUVEC after stimulation with VEGF165, HGF or both factors over 4â12 hrs. Studentâs t-test (Mean±S.D.; n = 4): * increased MCP-1 compared vs. HSA (p<0.05); # decreased MCP-1 compared vs. HSA or VEGF (p<0.01); ## decreased MCP-1 compared vs. VEGF (p<0.03). BâAutoradiograms of membrane stained for pIÎșBα Đž IÎșBα after Western blotting of extracts from HUVEC stimulated by VEGF165 (25 ng/ml), HGF (25 ng/ml) or VEGF165+HGF (25 ng/ml total); HSA (25 ng/ml) served as a negative, and TNF-α (5 ng/ml) as a positive control. CâIL-8 production by HUVEC after stimulation with VEGF165, HGF or both factors over 4â12 hrs. Studentâs t-test (Mean±S.D.; n = 3â4): * increased IL-8 compared vs. HSA (p<0.05); ** increased IL-8 compared vs. VEGF or HGF (p<0.001); *** increased IL-8 compared vs. VEGF or HGF (p<0.01). DâActivation of HIF and IL-8 promoter in EA.hy926 after treatment with VEGF, HGF and their combination. Data of luciferase-based reporter assay (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0197566#sec002" target="_blank">Materials and methods</a> for detailed description) Mann-Whitney U-test (Mean±S.D.; n = 3â4): *p<0.05 vs HSA; **p<0.025 vs. VEGF or HGF.</p
Influence of VEGF165 and HGF gene delivery on monocyte infiltration of peri-infarct area.
<p>AâPhotomicrographs of immunohistochemical visualization of monocytes in myocardium samples obtained at day 3 after MI and injection of pDNA; BâResults of evaluation showing changes of CD68+ cells density per mm<sup>2</sup> of tissue at days 3 and 7 of experiment (data presented as Mean±S.E.M.). Studentâs t-test (n = 4/group): *significant increase of CD68+ cells density (p<0.05 vs. âpC4Wâ negative control); **significant decrease of CD68+ cells density (p<0.05 vs. âpC4Wâ at corresponding time point).</p
Detection of human VEGF165 and HGF in rat myocardium explants.
<p>Primary tissue was harvested at days 3 or 7 after DNA injection (A) or homogenates of left ventricle harvested at day 3 after DNA injection (B); n = 2 animals per column, ELISA data presented as Mean±S.D.</p
Morphometry of LV sections obtained from study groups.
<p>AâRepresentative images of stained sections of myocardium obtained at day 14 of experiment (fibrotic depositions stain blue); BâResults of morphometry in experimental groups treated by VEGF165, HGF or combined gene delivery; Studentâs t-test (n = 4-5/group, presented as Mean±S.E.M.). LV fibrosis size graph: *p<0.05 vs âpC4Wâ negative control; **p<0.05 vs. âpC4Wâ negative control and vs. âVEGFâ or âHGFâ group. LV thickness graph: N.S.ânot significant vs. âpC4Wâ; # p<0.05 vs. âpC4Wâ. Dilatation index graph: N.S.ânot significant vs. âpC4Wâ; $ p<0.05 vs. âpC4Wâ. CâRepresentative images of myocardium cross-section stained for laminin (left panel) and results of cardiomyocyte length analysis in respective study groups (right graph). No significant intergroup variability was found (p>0.05).</p
- âŠ