We studied sintered Cd1-xCrxTe solid solution obtained by melting of Cd and CrTe components with x=0.05 Cr mole fraction. Structural studies show homogenous large grain polycrystal structure of the ...alloy. Measurements of the temperature dependence of the electrical conductivity of the samples reveal the semi-metallic properties with electrical conductivity 0.22 Ohm-1cm-1. The ferromagnetic resonance (FMR) studies of the single crystal sample taken from the polycrystalline bulk were carried out at room temperature on X band epr spectrometer. The FMR spectra consist of one broad line with a high value of the g factor. The line is of the Lorentz shape with a moderate asymmetry. The angular dependence of the resonance field was analyzed based on the Kittel and Van Vleck theories. We compared the angular dependence of the resonance field with that arising from the Van Vleck theory containing first and second magnetic anisotropy energy approach. The results indicate ferromagnetic properties of the material at room temperature.
There are only few studies concerning about long-term effect of growth hormone (GH) replacement therapy on bone mineral density and bone microstructure. To assess effect of GH replacement therapy on ...bone mineral density (BMD) and trabecular bone score (TBS) in adult GH deficient (AGHD) subjects over period of 10 years. From 2005 to 2018, a prospective study of AGHD patients was conducted in national referral center for treatment of GHD. All patients received subcutaneous recombinant human GH in an IGF 1-normalizing regimen once a day. Lumbar spine (L-spine) and total hip (TH) BMD using Hologic densitometers were measured at baseline and every two years during treatment with rhGH. TBS was derived from L1-L4 DXA using iNsight® software (Medimaps, France) at each time point. Periods of measurement were baseline, year 2; 4; 6; 8 and 10. In total, 63 patients (38 males, 25 females, mean age 25.1±16 years) were included in the study. After 10 years of GH treatment, IGF-1 significantly increased (~35 %), with greatest increase at year 2. During 10-year follow-up, L-spine BMD increased approximately of 7 % (NS). TH BMD increase of 11 % during follow-up (p=0.0003). The greatest increment of BMD was achieved at year 6 on both sites, L-spine (+6 %) and TH BMD (+13 %) (p<0.05). There was no significant change of TBS during whole follow-up. In this study, sustaining positive effect of GH replacement therapy on bone density in subjects with adult GH deficiency over 10 years of follow-up was observed. The study did not show effect on TBS, as indirect measure of trabecular bone microarchitecture.
This study evaluates bone mineral density (BMD) and trabecular bone score (TBS) in relationship with new markers of chronic kidney disease (CKD), fibroblast growth factor 23 (FGF23), and klotho. The ...patients in this cross-sectional study were divided as follows: group A -patients in stages G1-3; group B -patients in stages G4 - 5 according to KDIGO. Plasma levels of soluble klotho and FGF23 were determined by ELISA. Bone mineral density (BMD) and trabecular bone score (TBS) were measured. 74 patients with CKD (mean age 68.8 years) were included in the study. Higher levels of FGF23 were observed in group B (N=15) compared to group A (N=59; p=0.001) were observed. FGF23 was higher in group A compared to group B. Significant difference in TBS within the first 3 stages of CKD was observed (mean TBS in G1=1.375 vs. G2=1.340 vs. G3a=1.24; p<0.05) and negative correlation of FGF23 and TBS (R=-0.33; p=0.05) and positive correlation between klotho and TBS (R=0.419; p=0.04) was observed. This study confirmed that FGF23 and klotho are associated with TBS, but TBS reflects a decrease in kidney function only in the first 3 stages of CKD. Thus, FGF23 and klotho together with TBS are promising markers of early trabecular bone impairment in CKD.
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•A preparative IMODA strategy for the synthesis of pyrano3,4-cpyrrole-1,6-diones was proposed.•The reaction pathway developed is simple and strongly depends on substituents in ...thiophene ring.•The key step proceeds under mild reaction conditions and with a high level of diastereoselectivity.
We have developed an efficient approach toward the synthesis of functionalized hexahydropyrano3,4-cpyrrole-1,6-diones from readily accessible 3-thienylsubstituted allylamines and maleic anhydride. This transformation begins with the N-acylation of the allylamines with the anhydride, followed by the intramolecular oxo-Diels–Alder reaction (IMODA), which is accompanied by the tautomerization step, and ends with the formation of saturated pyrano3,4-cpyrroles.
Geosmithia
fungi are little known symbionts of bark beetles. Secondary metabolites of lilac colored species
G. lavendula
and other nine
Geosmithia
species were investigated in order to elucidate ...their possible role in the interactions of the fungi with environment. Hydroxylated anthraquinones (yellow, orange, and red pigments), were found to be the most abundant compounds produced into the medium during the submerged cultivation. Three main compounds were identified as 1,3,6,8-tetrahydroxyanthraquinone (
1
), rhodolamprometrin (1-acetyl-2,4,5,7-tetrahydroxyanthraquinone;
2
), and 1-acetyl-2,4,5,7,8-pentahydroxyanthraquinone (
3
). Compounds
2
and
3
(representing the majority of produced metabolites) inhibited the growth of G+-bacteria
Staphylococcus aureus
and
Bacillus subtilis
with minimum inhibitory concentration of 64–512 μg/mL. Anti-inflammatory activity detected as inhibition of cyclooxygenase-2 was found only for compound
3
at 1 and 10 μg/mL. Compound
2
interfered with the morphology, compound
3
with cell-cycle dynamics of adherent mammalian cell lines.
CdS/CdTe are still advance structures for solar cells. The performance and efficiency of such devices strongly depend on structure, thickness, size of crystallites and layer morphology. In this paper ...we have applied pulsed laser deposition (PLD) method for CdTe and CdS layers as well as CdS/CdTe heterostructures fabrication. The layers were deposited from single crystal targets onto ITO/glass substrates. PLD of CdTe layers results in polycrystalline mode of growth consisting of regular isolated crystallites of 0.5 μm size almost the same for all of them. Such crystal structure of layers seems to be very promising for solar cells design. The crystal structure of layers was examined by SEM as well as by RHEED. The characterization of layers and CdS/CdTe junctions was completed by optical and
I–
V measurements.
Although infected cell O2 concentration (Oi) is known to limit respiration and nitrogenase activity in legume nodules, techniques have not been available to measure both processes simultaneously in ...an individual legume nodule. Consequently, details of the relationship between nitrogenase activity and Oi are not fully appreciated. For the present study, a probe was designed that allowed open circuit measurements of H2 evolution (nitrogenase activity) and CO2 evolution (respiration rate) in a single attached soybean nodule while simultaneously monitoring fractional oxygenation of leghemoglobin (and thereby Oi) with a nodule oximeter. Compared to measurements of whole nodulated roots, use of the probe led to inhibition of nitrogenase activity in the single nodules. During oximetry measurements, total nitrogenase activity (TNA; peak H2 evolution in Ar/O2) in the single nodules was 16% of that in whole nodulated roots and 48% of nodulated root activity when Oi was not being measured simultaneously. This inhibition did not affect the nodules' ability to regulate Oi, because exposure to Ar/O2 (80:20, v/v) caused nitrogenase activity and respiration rate to decline, and this decline was linearly correlated with a concurrent decrease in Oi. When the nodules were subsequently exposed to a linear increase in external pO2 from 20 to 100% 02 at 2.7% O2/min, fractional leghemoglobin oxygenation first increased gradually and then more rapidly, reaching saturation at a pO2 between 76 and 100% O2. Plots of nitrogenase activity and respiration rate against Oi showed that rates increased with Oi up to a value of 57 nm, with half-maximal rates being attained at Oi values between 10 and 14 nM O2. The maximum nitrogenase activity achieved during the increase in pO2 (potential nitrogenase activity) was 30 to 57% of that measured in intact nodulated roots, showing that O2 limitation of nitrogenase activity could account for a significant proportion of the inhibition of TNA associated with the use of the probe. However, some factor(s) in addition O2 must have limited the activity of single nodules at both subsaturating and saturating Oi. At Oi values greater than about 57 nM, nitrogenase activity and nodule respiration were inhibited, but, because this inhibition has been shown previously to be readily reversible when the Oi was lowered, it was not attributed to direct O2 inactivation of the nitrogenase protein. These results indicate that maximum nitrogenase activity in legume nodules is supported by a narrow range of Oi values. Possible biochemical mechanisms are discussed for both O2 limitation of nitrogenase activity at low Oi and inhibition of nitrogenase activity at high Oi.
Performance of the cationic chiral Ru–BINAP complex in asymmetric hydrogenation of methyl-3-oxobutyrate (methylacetoacetate) in methanol was studied. Effects of temperature, pressure and the content ...of water on its activity and enantioselectivity were discussed. Attention was paid to the role of water in respect of the enhanced acetal formation in the presence of methanol. A simple approach to limit the content of acetal was introduced. The role of water addition was clarified. Tetrahydrofuran as a solvent system (with the addition of methanol or water) was also tested to minimize the acetal presence in the reaction mixture. In parallel the influence of oxygen on the catalyst stability was examined.
In legume nodules the O2 in the infected cells limits respiration and nitrogenase activity, becoming more severe if nodules are exposed to subambient O2 levels. To identify the site of O2 limitation, ...adenylate pools were measured in soybean (Glycine max) nodules that were frozen in liquid N2 before being ground, lyophilized, sonicated, and separated on density gradients of nonaqueous solvents (heptane/tetrachloroethylene) to yield fractions enriched in bacteroid or plant components. In nodules maintained in air, the adenylate energy charge (AEC = ATP + 0.5 ADP/ATP + ADP + AMP) was lower in the plant compartment (0.65 ± 0.04) than in the bacteroids (0.76 ± 0.095), but did not change when the nodulated root system was exposed to 10% O2. In contrast, 10% O2 decreased the bacteroid AEC to 0.56 ± 0.06, leading to the conclusion that they are the primary site of O2 limitation in nodules. To account for the low but unchanged AEC in the plant compartment and for the evidence that mitochondria are localized in O2-enriched microenvironments adjacent to intercellular spaces, we propose that steep adenylate gradients may exist between the site of ATP synthesis (and ADP use) in the mitochondria and the extra-mitochondrial sites of ATP use (and ADP production) throughout the large, infected cells.
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