The present work shows that the introduction of 0.25–1.25 wt% lanthanum to the composition of aluminum hydroxide at the stage of its hydrothermal synthesis allows increasing the content of the ...pseudoboehmite phase in the product up to 95 wt% and, as a consequence, reduces the content of the “amorphous” component. Lanthanum uniformly distributes over the surface of aluminum hydroxide as isolated cations with a surface density of 10–15 cations per 10 nm2. During plasticizing of lanthanum-modified pseudoboehmite followed by granulation and heat treatment, the formation of the oxide form of La is not observed, and the cations retain their isolated state. The specific surface area of La-modified alumina increases by 18–26 m2/g compared to the unmodified sample, while the pore volume remains the same and the average pore diameter slightly reduces. It was found that when the content of La in pseudoboehmite was 1 wt%, the temperature of reaching a residual sulfur content of 10 ppm in the hydrotreated diesel fuel was 5 °C lower comparing to the unmodified sample.
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•The effect of La addition at the stage of pseudoboehmite preparation was studied.•La promotes the formation of pseudoboehmite phase.•La is present as isolated cations on the surface of pseudoboehmite and alumina.•Catalyst with 1 wt% La shows the highest HDS and HDN activity.
Purpose
To evaluate the efficacy of alpha-lipoic acid (ALA) administration on hormonal and metabolic parameters of obese PCOS patients.
Methods
A group of 32 obese PCOS patients were selected after ...informed consent. 20 patients referred to have first grade relatives with diabetes type I or II. Hormonal and metabolic parameters as well as OGTT were evaluated before and after 12 weeks of ALA integrative administration (400 mg per os every day).
Results
ALA administration significantly decreased insulin, glucose, BMI and HOMA index. Hyperinsulinemia and insulin response to OGTT decreased both as maximal response (Δmax) and as AUC. PCOS with diabetes relatives showed the decrease also of triglyceride and GOT. Interestingly in all PCOS no changes occurred on all hormonal parameters involved in reproduction such as LH, FSH, and androstenedione.
Conclusions
ALA integrative administration at a low dosage as 400 mg daily improved the metabolic impairment of all PCOS patients especially in those PCOS with familiar diabetes who have a higher grade of risk of NAFLD and predisposition to diabetes.
It is shown that analysis of X-ray scattering using the atomic pair distribution function makes it possible to reveal the differences in the fine structure of alumina samples, which have similar ...powder diffraction patterns. Such differences consist in different populations of tetrahedral and octahedral sites in the spinel structure of alumina or the existence of nuclei of a certain phase. The approach applied made it possible to explain the formation of different phases, baerite and pseudoboehmite, upon the rehydration of alumina obtained from gibbsite by thermal activation on a rotating metal plate or in a hot gas flow, respectively.
Platinum catalysts supported onto bayerite alumina were synthesized and studied. Alumina of the θ-Al
2
O
3
type, which was prepared from metallic aluminum by an aluminate method, was used as a ...support, and platinum(IV) nitrate and hydrogen hexachloroplatinate(IV) precursors containing Pt
4+
ions were used for supporting an active component. The catalysts were studied by physicochemical methods such as X-ray phase analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, and ultraviolet-visible diffuse reflection spectroscopy. It was found that platinum occurred in a finely dispersed state in both of the catalysts, and it was uniformly distributed over the support surface. The particle sizes were 2.8 and 0.9 nm in the samples synthesized from platinum(IV) nitrate and hydrogen hexachloroplatinate(IV), respectively. The most uniform surface distribution, high dispersity, and a narrow particle-size distribution were obtained with the use of hydrogen hexachloroplatinate(IV). The catalysts were tested in the partial oxidation of natural gas. The catalyst synthesized using platinum(IV) nitrate afforded an almost thermodynamically equilibrium distribution of the reaction products of partial oxidation at a temperature of 700–800°С.
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Dense Gd
2
Zr
2
O
7
-based ceramics with the composition Gd
2
Zr
1.9
Be
0.1
O
6.9
, containing heterovalently substituted beryllium on the zirconium site, have been prepared for the first time via ...mechanical activation of an oxide mixture, followed by annealing of green compacts at 1500°C. The use of mechanical activation has been shown to enable the preparation of dense ceramics (relative density of 88%) by annealing for 5 min and gas-tight ceramics (relative density of 97.3%) by annealing for 4 h. Gd
2
Zr
1.9
Be
0.1
O
6.9
has a pure oxygen ion conductivity of 4.0 × 10
–3
S/cm at 800°C. The main advantage of partial beryllium substitution on the zirconium site in Gd
2
Zr
2
O
7
is the formation of a material having negligible electron and hole conductivities in wide ranges of oxygen partial pressures and temperatures.
Inherited retinal dystrophies (IRD) include a wide range of genetically and phenotypically heterogeneous diseases that lead to progressive loss of vision. With the development of gene therapy, it has ...become possible to treat two forms of IRD caused by biallelic mutations in the RPE65 gene: isolated retinitis pigmentosa (IRP) type 20 and Leber's congenital amaurosis (LCA) type 2. These nosologies are included in the list of orphan diseases of the Russian Ministry of Health. The success factor for the use of IRD gene therapy is the early stage of the disease, when the viability of retinal cells is preserved. An interdisciplinary approach to diagnostics makes it possible to timely establish the clinical and genetic variant of IRD and refer the patient to targeted therapy. Therefore, at a joint meeting of the Council of Experts of the North-Western Federal District of the Russian Federation, which included ophthalmologists and medical geneticists, a scheme for managing patients with IRD was accepted, including the stages of clinical and functional ophthalmological examination and molecular genetic testing. In addition, regional centers of expertise for IRD were approved in two federal medical institutions in St. Petersburg, whose task is to optimize the quality of diagnosing patients with IRP and LCA.
•The use of RhCl3 and two alumina modifications to prepare the supported catalysts.•Rh-particles with two types of sizes are formed on both alumina supports.•Rh in an oxidized state is located on the ...surface of reduced metal particles.•The catalyst supported on γ-Al2O3 has more Rh in metal and dispersed states.•Small Rh particles form on θ-Al2O3 in the reaction due to redispersion or sintering.
Rhodium catalysts supported on bayerite and pseudoboehmite alumina, calcined at 800 °С, were synthesized and tested in the partial oxidation of methane. Rhodium (III) chloride was used as an active component precursor. The supports and catalysts were investigated by a wide range of physicochemical methods: XRD, SEM and HR TEM, XPS and UV–vis DRS. In both cases, large rhodium particles with a coherent scattering region size of 15–19 nm are formed, and small ones with dimensions less than 1 nm. On the whole, smaller rhodium particles are formed on the bayerite oxide. The catalyst with pseudoboehmite-type support shows better results in the reaction.
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Samples of a woven mesh of metal wire (fechral) with supported aluminum hydroxide compounds are studied. Aluminum hydroxide is formed in its bayerite modification. Aluminum oxides are produced during ...calcination: η-Al
2
O
3
at 600°C, and θ-Al
2
O
3
at 900°C. Subsequent modification with silicon, cerium, lanthanum, tungsten, and calcination at the same temperature results in the formation of their oxides. Interaction between alumina and tungsten at 600°C, and alumina and lanthanum at 900°C, are observed.
An X-ray study of titaniaand alumina-supported rhodium catalysts for the hydrogenation of hydrocarbons is performed. Rhodium is shown to be present in the form of highly dispersed oxide, independent ...of the type of support. The atomic structure of alumina changes, while no change in the real structure of titanium oxide is observed.
Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl and Rh/Ni–MgO/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl FeCrAlloy wire mesh supported catalysts were prepared via multistep procedure. They were characterized by XRD, SEM and ...TEM techniques. A comparative study of autothermal reforming (ATR) of isooctane and simulated gasoline (blends of isooctane, ortho-xylene and naphthalene) over Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl and Rh/Ni–MgO/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl was performed. Both catalysts showed excellent performance in ATR of isooctane at molar ratios of O2:C = 0.51 and H2O:C = 2.59, T = 750°С and GHSV = 10000 h−1. In the ATR of isooctane – o-xylene blend in presence of Rh–Ni-containing catalyst carbon formation was observed. Rh-containing catalyst demonstrated rather good activity and stability even in the case of isooctane – o-xylene – naphthalene blend.
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•Rh/Ni–MgO/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl structured catalyst (Rh-Ni-CSC).•Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl structured catalyst (Rh-CSC).•Syngas production via autothermal reforming (ATR) of gasoline surrogates.•ATR of isooctane and its blends with o-xylene (20–30%) and naphthalene (1%).•Rh-CSC was stable in ATR of isooctane blends with aromatics.
