14 research outputs found
Negligible Effect of Estrogen Deficiency on Development of Skeletal Changes Induced by Type 1 Diabetes in Experimental Rat Models
Although postmenopausal osteoporosis often occurs concurrently with diabetes, little is known about interactions between
estrogen deficiency and hyperglycemia in the skeletal system. In the present study, the effects of estrogen deficiency on the
development of biochemical, microstructural, and mechanical changes induced by streptozotocin-induced diabetes mellitus
(DM) in the rat skeletal system were investigated. The experiments were carried out on nonovariectomized (NOVX) and
ovariectomized (OVX) control and diabetic mature female Wistar rats. Serum levels of bone turnover markers (CTX-I and
osteocalcin) and 23 cytokines, bone mass and mineralization, histomorphometric parameters, and mechanical properties of
cancellous and compact bone were determined. The results were subjected to two-way ANOVA and principal component
analysis (PCA). Estrogen deficiency induced osteoporotic changes, with increased bone resorption and formation, and
worsening of microstructure (femoral metaphyseal BV/TV decreased by 13.0%) and mechanical properties of cancellous bone
(the maximum load in the proximal tibial metaphysis decreased by 34.2%). DM in both the NOVX and OVX rats decreased
bone mass, increased bone resorption and decreased bone formation, and worsened cancellous bone microarchitecture (for
example, the femoral metaphyseal BV/TV decreased by 17.3% and 18.1%, respectively, in relation to the NOVX controls) and
strength (the maximum load in the proximal tibial metaphysis decreased by 35.4% and 48.1%, respectively, in relation to the
NOVX controls). Only in the diabetic rats, profound increases in some cytokine levels were noted. In conclusion, the changes
induced by DM in female rats were only slightly intensified by estrogen deficiency. Despite similar effects on bone
microstructure and strength, the influence of DM on the skeletal system was based on more profound systemic homeostasis
changes than those induced by estrogen deficiency
On Unbounded Composition Operators in -Spaces
Fundamental properties of unbounded composition operators in -spaces are
studied. Characterizations of normal and quasinormal composition operators are
provided. Formally normal composition operators are shown to be normal.
Composition operators generating Stieltjes moment sequences are completely
characterized. The unbounded counterparts of the celebrated Lambert's
characterizations of subnormality of bounded composition operators are shown to
be false. Various illustrative examples are supplied
Production and investigation of heavy neutron rich nuclei
A project devoted to the production and study of neutron rich heavy nuclei (GALS - project) is being realized at Flerov Laboratory for Nuclear Reactions (FLNR) - JINR. GALS is planned to exploit available beams from the U-400M cyclotron in low energy multi-nucleon transfer reactions to study exotic neutron rich nuclei located in the "north-east" region of nuclear map. Products from 4.5 to 9 MeV/nucleon heavy-ion collisions, such as 136Xe on 208Pb, are to be captured in a gas cell and selectively laser-ionized in a sextupole (quadrupole) ion guide extraction system
Production and investigation of heavy neutron rich nuclei
A project devoted to the production and study of neutron rich heavy nuclei (GALS - project) is being realized at Flerov Laboratory for Nuclear Reactions (FLNR) - JINR. GALS is planned to exploit available beams from the U-400M cyclotron in low energy multi-nucleon transfer reactions to study exotic neutron rich nuclei located in the "north-east" region of nuclear map. Products from 4.5 to 9 MeV/nucleon heavy-ion collisions, such as 136Xe on 208Pb, are to be captured in a gas cell and selectively laser-ionized in a sextupole (quadrupole) ion guide extraction system
Further development of GALS setup at JINR
The aim of this paper is to report on the present status of the GAs cell based Laser ionization and separation Setup (GALS project) that is under construction at the Flerov Laboratory of Nuclear Reactions (FLNR) of JINR, Dubna. This project is directed on production of neutron-rich isotopes in the region of the magic  = 126 neutron number using multi-nucleon transfer reactions. The laser laboratory extension based on new TiSa lasers was performed, options of using a straight sextupole (SPIG) or an S-shaped quadrupole ion guides in the setup were compared based on the computer simulations, and the work on the rest of the GALS subsystems is being continued
GALS – setup for production and study of heavy neutron rich nuclei
The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N = 126 below 208Pb is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleosynthesis. This area of the nuclear map can be reached neither in fusion–fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be significantly high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of 136Xe with 208Pb. A new setup is proposed to produce and study heavy neutron-rich nuclei located along the neutron closed shell N=126
GALS – setup for production and study of heavy neutron rich nuclei
The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N = 126 below 208Pb is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleosynthesis. This area of the nuclear map can be reached neither in fusion–fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be significantly high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of 136Xe with 208Pb. A new setup is proposed to produce and study heavy neutron-rich nuclei located along the neutron closed shell N=126
Studies of photo-nuclear reactions at astrophysical energies with an active-target TPC
An experiment was conducted at the High Intensity γ-ray Source (HIγS) facility at the Triangle Universities Nuclear Laboratory (TUNL) in Durham, NC, USA to measure the cross-section of the key astrophysical thermonuclear reaction 12C(α,γ)16O by means of its inverse photo-disintegration process. A high-intensity monochromatic γ-ray beam interacted with the CO2 gas in the active volume of the Warsaw active target TPC detector. The reaction products were detected and their momenta reconstructed, so to also determine angular correlations. Data were collected at 15 beam energies ranging from 8.51 to 13.9 MeV. Preliminary results are presented