Study of thermal effects of silicate-containing hydroxyapatites

The possibility of modifications of hydroxyapatite silicate ions, from the extracellular fluid prototype solution under near-physiological conditions has been studied. Formation of silicon-structured hydroxyapatite with different extent of substitution of phosphate groups in the silicate group has been established through chemical and X-ray diffraction analyses, FTIR spectroscopy and optical microscopy. The results obtained are in agreement and suggest the possibility of substitution of phosphate groups for silicate groups in the hydroxyapatite structure when introducing different sources of silica, tetraethoxysilane and sodium silicate, in the reaction mixture. Growth in the amount of silicon in Si-HA results in the increase in the thermal stability of the samples. The greatest mass loss occurs at temperatures in the range of 25-400 °С that is caused by the removal of the crystallization and adsorption water and volatile impurities. It is shown that the modified apatites are of imperfect structure and crystallize in a nanocrystalline state

Clinical aspects of tuberculous lesions of the spine in HIV-infected patients

The purpose of the study is to investigate and compare severity and manifestations of tuberculous spondylitis in patients with HIV infection in comparison with patients without this nosology.Цель исследования - изучить и сравнить тяжесть и проявления туберкулёзного спондилита у пациентов с ВИЧ-инфекцией в сравнении с пациентами без данной нозологии

Searches for new sources of CP violation using molecules as quantum sensors

We discuss how molecule-based searches offer complementary probes to study the violation of fundamental symmetries. These experiments have the potential to probe not only the electron EDM, but also hadronic CPV phenomena. Future experimental developments will offer generic sensitivity to probe flavor neutral sources of both leptonic and hadronic CPV at scales of ≥ 100 TeV, and flavor changing CPV at scales of ≥1000 TeV

ОБРАЗОВАНИЕ КОМПЛЕКСОВ МЕДИ(II) С ВОДОРАСТВОРИМЫМ β-ФУРФУРОЛОКСИМОМ

The paper is devoted to the interaction of copper(II) chloride with water soluble β-furfuraldoxime (N-(furan-2-ylmethyliden)hydroxylamine) in hydrochloric solutions. It was been revealed that the degree of copper(II) precipitation from aqueous solutions and hydrochloric solutions with the pH of 4 M HCl by this reagent is not higher than 52% even when the precipitant is used in abundance. These dependencies has been compared to the similar results of palladium(II) precipitation obtained when all other conditions were equal. It has been discovered that various complexes are formed when Cu(II) reacts with a β-furfuraldoxime and that it depends on the acidity of the solution. In weak acid solutions (0.01-0.1 M HCl) the «green» complex of composition [CuL4Cl2] was obtained and in this complex the oxime is coordinated with the central atom by an oxygen atom of the oxime group. The so-called «red» complex of composition [CuL2Cl2] is formed in the pH range of 1-4 M HCl and in ethanol. In this complex the coordination of ligand molecules is realized by the oxygen atom of the furan ring and by the oxygen of the oxime group. Reagent N-(furan-2-ylmethyliden)hydroxylamine can be used for practical quantitative release of palladium from hydrochloric solutions. However, it does not provide the separation of copper and palladium in their joint presence.В работе изучено взаимодействие хлорида меди(II) с водорастворимым β-фурфуролоксимом (N-(фуран-2-илметилиден)гидроксиламином) в солянокислых растворах. Выявлено, что степень осаждения меди(II) данным реагентом из водных растворов и до достижения кислотности 4 М HCl не превышает 52% даже при использовании избытка осадителя. Полученные зависимости сопоставлены с аналогичными данными для осаждения палладия(II) при прочих равных условиях. Установлено, что при взаимодействии Cu(II) с β-фурфуролоксимом в слабокислых растворах (0.01-0.1 М HCl) получается «зеленый» комплекс состава [CuL4Cl2], в котором оксим координируется к центральному атому через атом кислорода оксимной группы. В диапазоне кислотности 1-4 М HCl, а также в среде этилового спирта происходит образование так называемого «красного» комплекса состава [CuL2Cl2], в котором координация молекул лиганда осуществляется через атом кислорода фуранового кольца и кислорода оксимной группы. Реагент N-(фуран-2-илметилиден)-гидроксиламин может быть использован для практически количественного выделения палладия из солянокислых растворов, однако он не обеспечивает разделения меди и палладия при их совместном присутствии

Comparison of the novel START vascular stiffness index with the CAVI index, assessment of their values and correlations with clinical parameters

Aim. To compare the cardio-ankle vascular index (CAVI) and the novel START vascular stiffness index and assess their values and correlations with clinical parameters.Material and methods. This multicenter study included 928 (403 men and 525 women) randomly selected patients, aged 18 to 89 years (mean age, 41±15,8 years). Inclusion criteria were age over 18 years. There were following exclusion criteria: mental disorder, severe somatic diseases and cancer, contraindications for volume sphygmography using the Fukuda Denshi VS-1500 VaSera system, no patient consent, ankle-brachial index <1,0 and >1,3. Further, according to the main parameters obtained using volum sphygmography, a novel START index was calculated. Comparison of index values and analysis of their correlation with clinical indicators, such as age, systolic blood pressure, diastolic blood pressure, pulse pressure (PP), body mass index and heart rate (HR), were carried out using simple and multiple linear regression, dispersion analysis, calculation of the Pearson coefficient (r), in the software environment R version 4.0.2.Results. Statistical analysis revealed a high correlation between START and CAVI indices (r=0,986, p<0,001). The values of both indices increase significantly with age (ANOVA p><0,001). Both START and CAVI correlate with all studied clinical parameters. However, in men, there was no relationship of the indices with PP and HR (p>0,05). According to multiple linear regression, the relationship between diastolic blood pressure at the age of 30-60 years and PP at the age of 18-40 years with the START index is more pronounced than with the CAVI index. However, further study of the mathematical model did not reveal a significant difference in the index values for groups with and without high blood pressure.Conclusion. The START vascular stiffness index significantly correlates with the CAVI index, showing no significant differences from CAVI in quantitative relationships with blood pressure, body mass index, heart rate, and sex in various subgroups of the subjects

Thermal effects of carbonated hydroxyapatite modified by glycine and albumin

In this work calcium phosphate powders were obtained by precipitation method from simulated solutions of synovial fluid containing glycine and albumin. X-ray diffraction and IR spectroscopy determined that all samples are single-phase and are presented by carbonate containing hydroxyapatite (CHA). The thermograms of solid phases of CHA were obtained and analyzed; five stages of transformation in the temperature range of 25-1000°C were marked. It is shown that in this temperature range dehydration, decarboxylation and thermal degradation of amino acid and protein connected to the surface of solid phase occur. The tendency of temperature lowering of the decomposition of powders synthesized from a medium containing organic substances was determined. Results demonstrate a direct dependence between the concentration of the amino acid in a model solution and its content in the solid phase

The importance of EBIT data for Z-pinch plasma diagnostics

The results from the last six years of x-ray spectroscopy and spectropolarimetry of high energy density Z-pinch plasmas complemented by experiments with the electron beam ion trap (EBIT) at the Lawrence Livermore National Laboratory (LLNL) are presented. The two topics discussed are the development of M-shell x-ray W spectroscopic diagnostics and K-shell Ti spectropolarimetry of Z-pinch plasmas. The main focus is on radiation from a specific load configuration called an 'X-pinch'. X-pinches are excellent sources for testing new spectral diagnostics and for atomic modelling because of the high density and temperature of the pinch plasmas, which scale from a few {micro}m to several mm in size. They offer a variety of load configurations, which differ in wire connections, number of wires, and wire materials. In this work the study of X-pinches with tungsten wires combined with wires from other, lower-Z materials is reported. Utilizing data produced with the LLNL EBIT at different energies of the electron beam the theoretical prediction of line positions and intensity of M-shell W spectra were tested and calibrated. Polarization-sensitive X-pinch experiments at the University of Nevada, Reno (UNR) provide experimental evidence for the existence of strong electron beams in Ti and Mo X-pinch plasmas and motivate the development of x-ray spectropolarimetry of Z-pinch plasmas. This diagnostic is based on the measurement of spectra recorded simultaneously by two spectrometers with different sensitivity to the linear polarization of the observed lines and compared with theoretical models of polarization-dependent spectra. Polarization-dependent K-shell spectra from Ti X-pinches are presented and compared with model calculations and with spectra generated by a quasi-Maxwellian electron beam at the LLNL EBIT-II electron beam ion trap