A neutron collimator is developed to attenuate the neutron flux and reduce the residual induced activity in the interportal space of the diagnostic system of neutral particle analyzers of the ITER ...tokamak reactor. The collimator is installed in the port plug of the ITER vacuum vessel in front of an inlet to the vacuum pipeline of the diagnostic system. The collimator design has a cellular structure with 80% transparency for the neutral atom beam that goes out of the plasma and is recorded by the analyzers. However, because of increased scattering of neutrons in the collimator, their flux in the interportal room in the service zone of diagnostic systems of equatorial port no. 11 is significantly reduced and allows the equivalent dose rate in this zone to be decreased by several times. Thermal analysis showed that, during the reactor operation in modes with generation of the maximum power of 500 MW, the plasma radiation will cause the heating of the collimating grid to a temperature not exceeding 250°C, which makes it possible to select the stainless steel (316L(N)-ITER grade) as a material for manufacturing the collimator. In this case the cyclic strength of the collimator meets the ITER requirements, and it can be used without replacement during the entire deuterium-tritium experiment of the tokamak reactor.
This article assesses the economic efficiency of using Synoestrol-2% to down-calving cows for stimulate colostral immunity and non-specific resistance in newborn calves. Use of the drug positively ...affected the health of calves. At the same time, the immuno-biochemical and morphological composition of the blood in newborn calves improved to the first day after born: increased the level of total protein for 9.75% (p<0.05) compared to the control group of calves, albumins - 13.7% (p<0.05), alpha-globulins - 31% (p<0.05), gamma globulins - 21.8% (p<0.05), number of leukocyte increased for 17.2% (p<0.05). Ten days after birth, the content of alpha- and gamma- globulin decreased in the calves of the control and experimental groups, but it was significantly higher in the calves of the experimental group. The number of leukocytes was higher in the calves of the experimental group, mainly due to neutrophils. The first day after birth bactericidal activity of the blood serum, lysozyme activity of the blood serum, neutrophil phagocytic rate was higher compared with similar indicators calves of control group. The incidence of dyspepsia of calves of the experimental group decreased by 1.3 times, the duration of the disease was shorter by 1.7 days compared to calves of the control group. The economic efficiency of the use of the drug Sinoestrol-2% to cows was 3.12 rubles per 1 ruble of expenses.
We studied the function of the antioxidant system in tumor cell lines MCF-7 and H1299 that differ by the state of tumor suppressor gene p53. Exposure to different classes of cytotoxic compounds ...induced several types of antioxidant system responses that depend on the type of cell line. The effects of platinum(II) and platinum(IV) complexes on activity of antioxidant enzymes vary, which can be explained by differences in their accumulation and biotransformation in tumor cells. Triazole and oxazolidinone derivatives had little effect on activity of superoxide dismutase and catalase in H1299 cells, but increased superoxide dismutase activity in MCF-7 cells.
The paper reports a substantial improvement of the static and cyclic strength of a Cr-Ni-Ti austenitic stainless steel nanostructured by equal channel angular pressing (ECAP). After ECAP at room ...temperature or 673 K, the mean grain size decreased from 14 µm to 430 nm or 940 nm, respectively; corresponding ultimate tensile strength increased from 610 MPa to 1230 MPa or 940 MPa, and the fatigue limit increased from 275 MPa to 375 MPa or 475 MPa. These enhanced strength properties result from the grain refinement assisted by the intensive twinning in the austenite during ECAP at room temperature and 673 K as well as partial martensitic transformation during ECAP at room temperature. Moreover, the partial martensitic transformation and an increase in the fraction of high angle grain boundaries during subsequent high-cycle fatigue tests were particularly favorable for the improvement of fatigue properties.
The effect of inhibition of the tumor suppressor p53 on the antioxidant system genes expression under the influence of cytotoxic compounds of the platinum group was studied. It was found that the ...action of platinum(II) and platinum(IV) complexes induced accumulation of p53 protein with a maximum in 12 h, which was confirmed by an increase in the expression of the
P21
gene, the target gene of the p53 protein. It was shown that the action of platinum complexes activated the expression of catalase and superoxide dismutase 2 genes. Suppression of p53 protein functions with specific inhibitor α-piphitrin under the action of platinum complexes reduced the expression of catalase and superoxide dismutase 2 genes and the target gene P21, which attested to the p53-dependent regulation of these genes.
The conditions for obtaining stable aqueous solutions of a lipophilic aminonitroxyl platinum complex, namely,
e
-amine-
d
-(4-amino-2,2,6,6-tetramethylpiperidine 1-oxyl)-
a, f
-bis(octanoato)-
b, c
...-dichloroplatinum(
iv
), by means of its encapsulation into nanoparticles of copolymers of
N
-vinylpyrrolidone with triethylene glycol dimethacrylate with various monomer compositions and topologies were found. Aqueous solutions of the complex encapsulated into polymer particles were investigated by dynamic light scattering, the temperature dependence of nanostructure sizes was studied. Transmission electron microscopy established that the hybrid nanostructures are core—shell particles, in which the platinum complex forms small clusters (∼4 nm). The parameters of ESR spectra of aqueous dispersions indicate a high mobility of nitroxyl contained in hybrid nanostructures. Voltammetric measurements demonstrate a similarity of the redox reactions related to the free radical fragment of the aminonitroxyl Pt
IV
complex and of the 4-acetylamino-2,2,6,6-tetramethylpiperidine 1-oxyl radical. Polymer products containing the platinum complex were studied by IR spectroscopy, TGA, and DSC. The cytotoxicity index (IC
50
) of the free and the encapsulated complex was determined for
HeLa
tumor cells. The cytotoxicity of the latter (IC
50
47–205 nmol L
−1
) depends on the monomeric composition of the nanoparticles and the incubation time.
The temperature dependences of the specific resistance and Hall coefficient of high-quality synthetic boron-doped diamond single crystals grown via a high-pressure high-temperature method are ...studied. The concentration of acceptors in the (001) cut plates was varied in a range of 2 × 10
15
–3 × 10
17
cm
–3
by varying the concentration of boron in the growth mixture (0.0004–0.04 at %). Thin rectangular plates with the uniform concentration of boron and free from extended structural defects are cut out by a laser after the X-ray topography and mapping of UV luminescence. The concentrations of donors and acceptors in the samples are calculated from the data of the Hall effect and capacitance–voltage characteristics. The obtained results correlate with the concentration of boron in the growth mixture. The minimum compensation ratio of acceptors with donors (below 1%) is observed in the crystals grown with the concentration of boron in the growth mixture of 0.002 at %. The ratio increases when the amount of boron is increased or decreased. The samples grown at such a concentration of boron have the maximum mobility of charge carriers (2200 cm
2
/(V s) at
T
= 300 K and 7200 cm
2
/(V s) at
T
= 180 K). The phonon scattering of holes dominates throughout the range of temperatures (180–800 K), while the scattering by point defects (neutral and ionized atoms of the impurity) is insignificant. The diamond crystals which are grown from a mixture containing 0.0005–0.002 at % boron and have perfect quality and a lattice mechanism of scattering can be considered as a reference semiconductor.
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