The doping of hydroxyapatite with various substituent ions can give this material new and useful properties. Nonetheless, local distortions of structure after doping can change the properties of the ...material. In this work, the thermal stability of copper-substituted hydroxyapatite synthesized by the mechanochemical method was investigated. In situ diffraction analyses showed that copper ion diffusion during the heating of Cu-substituted hydroxyapatite promotes phase transformations in the substituted hydroxyapatite. The behavior of copper ions was studied in samples with ratios (Ca + Cu)/P = 1.75 and 1.67. It was found that in both cases, single-phase Cu-substituted hydroxyapatite with the general formula Ca10−xCux(PO4)6−y(CO3)y(OH)2−yOy is formed by the mechanochemical synthesis. When heated at approximately 600–700 °C, the lattice loses copper cations, but at higher temperatures, CuO diffusion into the hydroxyl channel takes place. Cuprate-substituted hydroxyapatite with the general formula Ca10(PO4)6(OH)2−2x(CuO2)x forms in this context. At 1200 °C, the sample is single-phase at (Ca + Cu)/P = 1.75. Nonetheless, slow cooling of the material leads to the emergence of a CuO phase, as in the case of (Ca + Cu)/P = 1.67, where the material contains not only CuO but also Cu-substituted tricalcium phosphate. In the manufacture of ceramic products from Cu-substituted hydroxyapatite, these structural transformations must be taken into account, as they alter not only thermal but also biological properties of such materials.
Magnesium, as one of the most abundant cations in the human body, plays an important role in both physiological and pathological processes. In this study, it was shown that a promising biomedical ...material, Mg-substituted hydroxyapatite (Mg-HA), can be synthesized via a fast mechanochemical method. For this method, the nature of magnesium-containing carriers was shown to be important. When using magnesium oxide as a source of magnesium, the partial insertion of magnesium cations into the apatite structure occurs. In contrast, when magnesium hydroxide or monomagnesium phosphate is used, single-phase Mg-HA is formed. Both experimental and theoretical investigations showed that an increase in the Mg content leads to a decrease in the lattice parameters and unit cell volume of Mg-HA. Density functional theory calculations showed the high sensitivity of the lattice parameters to the crystallographic position of the calcium site substituted by magnesium. It was shown experimentally that the insertion of magnesium cations decreases the thermal stability of hydroxyapatite. The thermal decomposition of Mg-HA leads to the formation of a mixture of stoichiometric HA, magnesium oxide, and Mg-substituted tricalcium phosphate phases.
The results of a study (1991–2007) of microalgae communities from a rocky substrate (phytoepilithon) in the littoral zone of Lake Teletskoye found at a depth of up to 1.5 m are presented. The ...features of the spatial and temporal organization of microalgae communities coexisting in rocky-substrate–water, land–water, and tributary–lake ecotones are presented. It is shown that microalgae of ecotones are adapted to the intensity and instability of the abiotic factors.
Apatite is widely used in medicine as a biomaterial for bone tissue restoration. Properties of apatite depend on its composition, including the Ca/P ratio. This paper shows what range of Ca/P ratio ...can be attained in apatite by the mechanochemical method of synthesis, providing fast formation of a single-phase product. The synthesis was carried out from a reaction mixture of CaHPO4 and CaO at different Ca/P ratios in the range of 1.17–2.10. The products were studied by PXRD, FTIR and NMR spectroscopy, HRTEM, and STA. In mixtures with a low initial Ca/P ratio (1.17–1.48), directly in the mill, the formation of calcium orthophosphate with whitlockite structure containing an HPO42− group and structural water is shown for the first time. This phosphate has structure similar to that of whitlockites of hydrothermal origin and differs from high-temperature β-tricalcium phosphate that has composition Ca3(PO4)3. A series of samples of apatite was obtained with varied composition, which depends on the initial Ca/P ratio. At Ca/P < 1.67, the formation of two types of calcium-deficient apatite was documented. At Ca/P > 1.67, the existence of two types of calcium-rich apatite is confirmed.
1Moscow Clinical Research and Practical Center, Moscow Healthcare Department, Moscow; 2A.I. Evdokimov Moscow State University of Medicine and Dentistry, Ministry of Health of Russia, Moscow; 3Kazan ...State Medical University, Kazan; 4Kazan (Volga) Federal University, Kazan; 5Far Eastern State Medical University, Ministry of Health of Russia, Khabarovsk; 6Morozov City Children’s Clinical Hospital, Moscow Healthcare Department, Moscow; 7I.I. Mechnikov North-Western State Medical University, Ministry of Health of Russia, Saint Petersburg; 8Siberian State Medical University, Ministry of Health of Russia, Tomsk; 9M.F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow; 10Maimonides State Classical Academy, Moscow; 11V.I. Razumovsky Saratov State Medical University, Saratov; 12I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow; 13S.M. Kirov Military Medical Academy, Ministry of Defense of the Russian Federation, Saint Petersburg; 14Surgut State Medical University, Ministry of Health of Russia, Surgut; 15City Clinical Hospital Five, Moscow Healthcare Department, Moscow; 16Nizhny Novgorod Medical Academy, Ministry of Health of Russia, Nizhny Novgorod; 17Territorial Clinical Hospital Two, Ministry of Health of the Krasnodar Territory, Krasnodar; 18Saint Petersburg State Pediatric Medical University, Ministry of Health of Russia, Saint Petersburg; 19Rostov State Medical University, Ministry of Health of Russia, Rostov-on-Don; 20Omsk Medical University, Ministry of Health of Russia, Omsk; 21Russian Medical Academy of Postgraduate Education, Ministry of Health of Russia, Moscow; 22Novosibirsk State Medical University, Novosibirsk; 23Stavropol State Medical University, Ministry of Health of Russia, Stavropol; 24Kemerovo State Medical University, Ministry of Health of Russia, Kemerovo; 25N.I. Pirogov Russian Research Medical University, Ministry of Health of Russia, Moscow; 26A.M. Nikiforov All-Russian Center of Emergency and Radiation Medicine, Ministry of Emergency Situations of Russia, Saint Petersburg; 27Federal Research Center, Krasnoyarsk Research Center, Siberian Branch, Russian Academy of Sciences, Research Institute of Medical Problems of the North, Krasnoyarsk; 28S.P. Botkin City Clinical Hospital, Moscow Healthcare Department, Moscow; 29Tver State Medical University, Ministry of Health of Russia, Tver The Russian consensus (a consensus document) on the diagnosis and treatment of chronic pancreatitis has been prepared on the initiative of the Russian «Pancreatic Club» under the Delphi system. Its aim was to identify and consolidate the opinions of Russian experts on the most topical issues of the diagnosis and treatment of chronic pancreatitis. The interdisciplinary approach involved the participation of leading gastroenterologists, surgeons, and pediatricians.
—
Zinc-substituted hydroxyapatite samples with a preset degree of substitution (Са
10 –
х
Zn
x
(PO
4
)
6
(OH)
2
,
x
= 0.1–2.0) have been synthesized by a mechanochemical method. The composition of ...starting components ((Zn(H
2
PO
4
)
2
⋅ 2Н
2
О and ZnO) and water of crystallization have been shown to influence the apatite structure formation process and the degree of zinc substitution for calcium in the mechanochemical synthesis and annealing processes. When ZnO was used as a dopant, beta-tricalcium phosphate was observed to form as a reaction intermediate directly in the mill after 5–10 min of the reaction mixture milling and disappear after 20 min of milling. The final synthesis product—zinc-substituted hydroxyapatite—remains single-phase for
x
≤ 0.8 in the case of Zn(H
2
PO
4
)
2
⋅ 2Н
2
О and
x
≤ 0.25 in the case of ZnO. After annealing, the zinc-substituted hydroxyapatite is single-phase only in the case of zinc phosphate using at
x
≤ 0.1.
The Gram-negative bacterium
Lysobacter
sp. XL1 produces outer membrane vesicles that are heterogeneous in size, density, and protein composition. One of the subpopulations is secretory vesicles for ...lytic protease L5 of
Lysobacter
sp. XL1 (Kudryakova et al. (2015)
FEMS Microbiol. Lett
.,
362
, fnv137). Protein L5 was assumed to influence biogenesis of these secretory vesicles that contain it. Using a
Pseudomonas fluorescens
Q2-87/B expression system, it was shown that the recombinant L5 protein may act as a factor of vesicle biogenesis. This points to a possible involvement of L5 protein in
Lysobacter
sp. XL1 vesicle biogenesis. Furthermore, it was established that the main phospholipid of
Lysobacter
sp. XL1 vesicles is cardiolipin, and vesicles are formed predominantly of outer membrane regions enriched with this phospholipid. This indicates that cardiolipin participates in biogenesis of all vesicle subpopulations in
Lysobacter
sp. XL1.
Extracellular vesicles (EVs), including exosomes, are key factors of intercellular communication, performing both local and distant transfers of bioactive molecules. The increasingly obvious role of ...EVs in carcinogenesis, similarity of molecular signatures with parental cells, precise selection and high stability of cargo molecules make exosomes a promising source of liquid biopsy markers for cancer diagnosis. The uterine cavity fluid, unlike blood, urine and other body fluids commonly used to study EVs, is of local origin and therefore enriched in EVs secreted by cells of the female reproductive tract. Here, we show that EVs, including those corresponding to exosomes, could be isolated from individual samples of uterine aspirates (UA) obtained from epithelial ovarian cancer (EOC) patients and healthy donors using the ultracentrifugation technique. First, the conducted profiling of small RNAs (small RNA-seq) from UA-derived EVs demonstrated the presence of non-coding RNA molecules belonging to various classes. The analysis of the miRNA content in EVs from UA performed on a pilot sample revealed significant differences in the expression levels of a number of miRNAs in EVs obtained from EOC patients compared to healthy individuals. The results open up prospects for using UA-derived EVs as a source of markers for the diagnostics of gynecological cancers, including EOC.
Pancreatology Club Professional Medical Community, 1A.S. Loginov Moscow Clinical Research and Practical Center, Moscow Healthcare Department, Moscow; 2A.I. Evdokimov Moscow State University of ...Medicine and Dentistry, Ministry of Health of Russia, Moscow; 3Kazan State Medical University, Ministry of Health of Russia, Kazan; 4Kazan (Volga) Federal University, Kazan; 5Far Eastern State Medical University, Ministry of Health of Russia, Khabarovsk; 6Morozov City Children's Clinical Hospital, Moscow Healthcare Department, Moscow; 7I.I. Mechnikov North-Western State Medical University, Ministry of Health of Russia, Saint Petersburg; 8Siberian State Medical University, Ministry of Health of Russia, Tomsk; 9M.F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow; 10Maimonides State Classical Academy, Moscow; 11V.I. Razumovsky State Medical University, Ministry of Health of Russia, Saratov; 12I.M. Sechenov First Moscow State Medical University, Ministry of Health of Russia, Moscow; 13S.M. Kirov Military Medical Academy, Ministry of Defense of Russia, Saint Petersburg; 14Surgut State Medical University, Ministry of Health of Russia, Surgut; 15City Clinical Hospital Five, Moscow Healthcare Department, Moscow; 16Nizhny Novgorod Medical Academy, Ministry of Health of Russia, Nizhny Novgorod; 17Territorial Clinical Hospital Two, Ministry of Health of the Krasnodar Territory, Krasnodar; 18Saint Petersburg State Pediatric Medical University, Ministry of Health of Russia, Saint Petersburg; 19Rostov State Medical University, Ministry of Health of Russia, Rostov-on-Don; 20Omsk Medical University, Ministry of Health of Russia, Omsk; 21Russian Medical Academy of Postgraduate Education, Ministry of Health of Russia, Moscow; 22Novosibirsk State Medical University, Ministry of Health of Russia, Novosibirsk; 23Stavropol State Medical University, Ministry of Health of Russia, Stavropol; 24Kemerovo State Medical University, Ministry of Health of Russia, Kemerovo; 25N.I. Pirogov Russian National Research Medical University, Ministry of Health of Russia, Moscow; 26A.M. Nikiforov All-Russian Center of Emergency and Radiation Medicine, Russian Ministry for Civil Defense, Emergencies and Elimination of Consequences of Natural Disasters, Saint Petersburg; 27Research Institute for Medical Problems of the North, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk; 28S.P. Botkin City Clinical Hospital, Moscow Healthcare Department, Moscow; 29Tver State Medical University, Ministry of Health of Russia, Tver The Russian consensus on the diagnosis and treatment of chronic pancreatitis has been prepared on the initiative of the Russian Pancreatology Club to clarify and consolidate the opinions of Russian specialists (gastroenterologists, surgeons, and pediatricians) on the most significant problems of diagnosis and treatment of chronic pancreatitis. This article continues a series of publications explaining the most significant interdisciplinary consensus statements and deals with enzyme replacement therapy.
The behavior of planetary waves and their influence on the global circulation of the Northern Hemisphere during different El Niño types is studied. Three sets of five boreal winters were chosen for ...each El Niño type: Modoki I and II and canonical El Niño. Based on data of the Japanese 55-year Reanalysis and the Modern-Era Retrospective Analysis for Research and Applications, the spatio-temporal structure of planetary waves and the residual mean circulation were analyzed. The results show that the canonical El Niño type is characterized by the weakest wave activity in March. It is also demonstrated that warming of the polar stratosphere, accompanied by maximizing wave activity and weakening of the zonal wind, may lead to earlier stratospheric polar vortex collapse and the early spring transition under Modoki I conditions. This study is the next step in understanding of the so-called long-range teleconnections, consisting of the propagation of a signal from the tropical El Niño Southern Oscillation source into the polar stratosphere.
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