The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes m...The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes mellitus is currently approaching half a billion,hence the crucial relevance of new methods to stimulate regeneration of the insulin-secretingβ-cells of the islets of Langerhans.Natural restrictions on the islet regeneration are very tight;nevertheless,the islets are capable of physiological regeneration viaβ-cell self-replication,direct differentiation of multipotent progenitor cells and spontaneousα-toβ-orδ-toβ-cell conversion(trans-differentiation).The existing preclinical models ofβ-cell dysfunction or ablation(induced surgically,chemically or genetically)have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation.The ultimate goal,sufficient level of functional activity ofβ-cells or their substitutes can be achieved by two prospective broad strategies:β-cell replacement andβ-cell regeneration.The“regeneration”strategy aims to maintain a preserved population ofβ-cells through in situ exposure to biologically active substances that improveβ-cell survival,replication and insulin secretion,or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β-toβ-cell conversion.The“replacement”strategy implies transplantation ofβ-cells(as non-disintegrated pancreatic material or isolated donor islets)orβ-like cells obtained ex vivo from progenitors or mature somatic cells(for example,hepatocytes orα-cells)under the action of small-molecule inducers or by genetic modification.We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally activeβ-cells,the innermost hope of millions of people globally.展开更多
An unusual feature of the saline stratified lakes that were formed due to ongoing postglacial uplift on the White Sea coast is the presence of several differently colored thin layers in the zone with sharp gradients. ...An unusual feature of the saline stratified lakes that were formed due to ongoing postglacial uplift on the White Sea coast is the presence of several differently colored thin layers in the zone with sharp gradients. Colored layers in five lakes at various stages of separation from the sea were investigated using optical microscopy, spectrophotometry, spectrofluorimetry, and photobiology. The upper greenish colored layer located in the aerobic strata of all lakes near the compensation depth of 1% light penetration contains green algae. In the chemocline, another layer, brightly green, red or pink, is dominated by mixotrophic flagellates. Despite the very low light intensities and the presence of H 2 S, active photosynthesis by these algae appears to be occurring, as indicated by high values of the maximum quantum yield of primary photochemistry, electron transport activity, photosynthetic activity of photosystem II, the fraction of active centers, and low values of heat dissipation. In the reduced zone of the chemocline, a dense green or brown suspension of anoxygenic phototrophs(green sulfur bacteria) is located.展开更多
The generalization of Einstein’s special theory of relativity (SRT) is proposed. In this model, the possibility of unification of scalar gravity and electromagnetism into a single unified field is considered. Formall...The generalization of Einstein’s special theory of relativity (SRT) is proposed. In this model, the possibility of unification of scalar gravity and electromagnetism into a single unified field is considered. Formally, the generalization of the SRT is that instead of (1+3)-dimensional Minkowski space the (1+4)-dimensional extension G is considered. As the fifth additional coordinate the interval S is used. This value is saved under the usual Lorentz transformations in Minkowski space M, but it changes when the transformations in the extended space G are used. We call this model the extended space model (ESM). From a physical point of view, our expansion means that processes in which the rest mass of the particles changes are acceptable now. If the rest mass of a particle does not change and the physical quantities do not depend on an additional variable S, then the electromagnetic and gravitational fields exist independently of each other. But if the rest mass is variable and there is a dependence on S, then these two fields are combined into a single unified field. In the extended space model a photon can have a nonzero mass and this mass can be either positive or negative. In this model the 5- vectors which components correspond to energy, pulse and mass of a particle are isotropic both for massive and massless particles. The rotations in the (1+4) dimensional extended space G can transform massive particles into massless and vice versa.展开更多
A longitudinal magnetic field often suffers the saturation effect in a strong magnetic field region when the measurement is performed at a single-wavelength point and linear calibration is adopted.In this study,we dev...A longitudinal magnetic field often suffers the saturation effect in a strong magnetic field region when the measurement is performed at a single-wavelength point and linear calibration is adopted.In this study,we develop a method that can judge the threshold of saturation in Stokes V/I observed by the Solar Magnetic Field Telescope(SMFT)and correct it automatically.The procedure is to first perform the second-order polynomial fit to the Stokes V/I vs.I/I_(m)(I_(m) is the maximum value of Stokes I)curve to estimate the threshold of saturation,then reconstruct Stokes V/I in a strong field region to correct for saturation.The algorithm is demonstrated to be effective by comparing with the magnetograms obtained by the Helioseismic and Magnetic Imager(HMI).The accuracy rate of detection and correction for saturation is~99.4%and~88%respectively among 175 active regions.The advantages and disadvantages of the algorithm are discussed.展开更多
Parkinson’s disease (PD) is one of the most common human neurodegenerative disorders caused by the loss of dopaminergic neurons in the brain. The α-synuclein (SNCA) gene is one of the most studied genes involved in ...Parkinson’s disease (PD) is one of the most common human neurodegenerative disorders caused by the loss of dopaminergic neurons in the brain. The α-synuclein (SNCA) gene is one of the most studied genes involved in the pathogenesis of PD. In our study, we conducted a genetic analysis of promoter and intron single-nucleotide polymorphisms (SNPs) in the SNCA gene. We also analyzed the association of genotypes of these SNPs with expression levels of SNCA mRNA. One of four SNPs in the SNCA gene, and the rs2736990 polymorphism, associates with the risk of the sporadic form of PD in Russian population. The risk of PD was increased almost twofold in carriers of allele C (odds ratios = 1.9, 95% confidence interval: 1.2-2.91, p = 0.003). However, no association was found between any of the genotypes of SNPs tested (rs2583988, rs2619363, rs2619364 and rs2736990) and alterations in SNCA levels. Our findings support the hypothesis that the rs2736990 polymorphism is associated with PD. SNPs rs2583988, rs2619363 and rs2619364 in the promoter region of the SNCA gene themselves do not significantly influence the expression of SNCA. Most likely, SNCA gene expression is a very complex process that is affected by different genetic and epigenetic factors.展开更多
This work presents the results of complex gravity observation performed at Shults Cape, Gamov peninsula (42.58°N, 131.15°E), Russia. Absolute laser gravimeter GABL type and Scintrex type relative gravimeter ...This work presents the results of complex gravity observation performed at Shults Cape, Gamov peninsula (42.58°N, 131.15°E), Russia. Absolute laser gravimeter GABL type and Scintrex type relative gravimeter were used for measurement. To investigate the accuracy of tidal corrections we compared the observed tidal parameters of the main tidal waves O1 and M2 with modeled ones computed from 6 different ocean tidal models: CSR4, FES02, FES04, GOT00, NAO99 and TPX06. After discussion a theoretical model based on TPX06 ocean tides model and DDW99 non hydrostatic body tides model was used for tidal correction of absolute gravity data. Preliminary estimate of gravity effect induced by the Tohoku-Oki earthquake of11 March 2011Mw = 9.0 at Primorye territory (Russia) was found to be 5.1 ± 2.0 μGal. Co-seismic crustal displacements revealed by GPS data at Far EastRussiacontinental coast are also investigated. Volumetric dilatation of this area is observed at +1.7 × 10-8 level.展开更多
In this paper,we establish a novel unique continuation property for two-dimensional anisotropic elasticity systems with partial information.More precisely,given a homogeneous elasticity system in a connected open boun...In this paper,we establish a novel unique continuation property for two-dimensional anisotropic elasticity systems with partial information.More precisely,given a homogeneous elasticity system in a connected open bounded domain,we investigate the unique continuation by assuming only the vanishing of one component of the solution in a subdomain.Using the corresponding Riemann function,we prove that the solution vanishes in the whole domain provided that the other component vanishes at one point up to its second derivatives.Further,we construct several examples showing the possibility of further reducing the additional information of the other component.This result possesses remarkable significance in both theoretical and practical aspects because the required data are almost halved for the unique determination of the whole solution.展开更多
The influence of intergalactic magnetic fields on the strong gravitational lensing of blazar secondary gamma radiation is discussed.Currently,two cases of strong gravitational lensing of blazar gamma-radiation are kno...The influence of intergalactic magnetic fields on the strong gravitational lensing of blazar secondary gamma radiation is discussed.Currently,two cases of strong gravitational lensing of blazar gamma-radiation are known,where radiation is deflected by galaxies on the line of sight between the blazars and Earth.The magnetic field can affect the movements of electron-positron pairs generated by primary radiation,thereby changing the directions of secondary gamma radiation.It modifies the equation of the gravitational lens and leads to the dependence of the observed signal in the secondary gamma radiation on the energy of photons and magnetic field.Accordingly,it is possible,in principle,to estimate the intergalactic magnetic fields from the time delay of signals,from the angular position of images(for future high-resolution gamma-ray telescopes)or from the shape of the observed energy spectrum.This method is demonstrated by the example of the blazar B0218+357.In this case,however,it is not possible to obtain useful constraints due to the large distances to the blazar and lens galaxy.The result is only a lower limit on the magnetic field B>2×10^(−17)G,which is weaker than other existing constraints.However,future discoveries of lensed blazars may provide more favorable opportunities for measuring the magnetic fields,especially with the help of a new generation of gamma-ray telescopes such as e-ASTROGAM,GECAM,and SVOM as well as future gamma-ray telescopes with a high angular resolution,∼0.1″.展开更多
Du 15 au 16 septembre 2022,la 22^(e)réunion du Conseil des chefs d’État des pays membres de l’Organisation de coopération de Shanghai(OCS)s'est tenue à Samarcande en Ouzbékistan.Au...Du 15 au 16 septembre 2022,la 22^(e)réunion du Conseil des chefs d’État des pays membres de l’Organisation de coopération de Shanghai(OCS)s'est tenue à Samarcande en Ouzbékistan.Au cours du Sommet,les chefs d'Élats ont eu des discussions en petit comité,cl ceux de tous les pays participants ont conjointement tenu des discussions en assemblée.展开更多
Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original ar...Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original article has been corrected.展开更多
基金Supported by the President Grant for Government Support of Young Russian Scientists,No.075-15-2019-1120.
文摘The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes mellitus is currently approaching half a billion,hence the crucial relevance of new methods to stimulate regeneration of the insulin-secretingβ-cells of the islets of Langerhans.Natural restrictions on the islet regeneration are very tight;nevertheless,the islets are capable of physiological regeneration viaβ-cell self-replication,direct differentiation of multipotent progenitor cells and spontaneousα-toβ-orδ-toβ-cell conversion(trans-differentiation).The existing preclinical models ofβ-cell dysfunction or ablation(induced surgically,chemically or genetically)have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation.The ultimate goal,sufficient level of functional activity ofβ-cells or their substitutes can be achieved by two prospective broad strategies:β-cell replacement andβ-cell regeneration.The“regeneration”strategy aims to maintain a preserved population ofβ-cells through in situ exposure to biologically active substances that improveβ-cell survival,replication and insulin secretion,or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β-toβ-cell conversion.The“replacement”strategy implies transplantation ofβ-cells(as non-disintegrated pancreatic material or isolated donor islets)orβ-like cells obtained ex vivo from progenitors or mature somatic cells(for example,hepatocytes orα-cells)under the action of small-molecule inducers or by genetic modification.We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally activeβ-cells,the innermost hope of millions of people globally.
基金Supported by the RFBR(Nos.16-05-00548-a,16-05-00502-a)
文摘An unusual feature of the saline stratified lakes that were formed due to ongoing postglacial uplift on the White Sea coast is the presence of several differently colored thin layers in the zone with sharp gradients. Colored layers in five lakes at various stages of separation from the sea were investigated using optical microscopy, spectrophotometry, spectrofluorimetry, and photobiology. The upper greenish colored layer located in the aerobic strata of all lakes near the compensation depth of 1% light penetration contains green algae. In the chemocline, another layer, brightly green, red or pink, is dominated by mixotrophic flagellates. Despite the very low light intensities and the presence of H 2 S, active photosynthesis by these algae appears to be occurring, as indicated by high values of the maximum quantum yield of primary photochemistry, electron transport activity, photosynthetic activity of photosystem II, the fraction of active centers, and low values of heat dissipation. In the reduced zone of the chemocline, a dense green or brown suspension of anoxygenic phototrophs(green sulfur bacteria) is located.
文摘The generalization of Einstein’s special theory of relativity (SRT) is proposed. In this model, the possibility of unification of scalar gravity and electromagnetism into a single unified field is considered. Formally, the generalization of the SRT is that instead of (1+3)-dimensional Minkowski space the (1+4)-dimensional extension G is considered. As the fifth additional coordinate the interval S is used. This value is saved under the usual Lorentz transformations in Minkowski space M, but it changes when the transformations in the extended space G are used. We call this model the extended space model (ESM). From a physical point of view, our expansion means that processes in which the rest mass of the particles changes are acceptable now. If the rest mass of a particle does not change and the physical quantities do not depend on an additional variable S, then the electromagnetic and gravitational fields exist independently of each other. But if the rest mass is variable and there is a dependence on S, then these two fields are combined into a single unified field. In the extended space model a photon can have a nonzero mass and this mass can be either positive or negative. In this model the 5- vectors which components correspond to energy, pulse and mass of a particle are isotropic both for massive and massless particles. The rotations in the (1+4) dimensional extended space G can transform massive particles into massless and vice versa.
基金supported by the National Natural Science Foundation of China(Grant Nos.11703042,11911530089,U1731241,11773038,11427901,11427803,11673033,U1831107,11873062)the Strategic Priority Research Program on Space Science+1 种基金Chinese Academy of Sciences(Grant Nos.XDA15320302,XDA15052200,XDA15320102)the13th Five-year Informatization Plan of Chinese Academy of Sciences(Grant No.XXH13505–04)。
文摘A longitudinal magnetic field often suffers the saturation effect in a strong magnetic field region when the measurement is performed at a single-wavelength point and linear calibration is adopted.In this study,we develop a method that can judge the threshold of saturation in Stokes V/I observed by the Solar Magnetic Field Telescope(SMFT)and correct it automatically.The procedure is to first perform the second-order polynomial fit to the Stokes V/I vs.I/I_(m)(I_(m) is the maximum value of Stokes I)curve to estimate the threshold of saturation,then reconstruct Stokes V/I in a strong field region to correct for saturation.The algorithm is demonstrated to be effective by comparing with the magnetograms obtained by the Helioseismic and Magnetic Imager(HMI).The accuracy rate of detection and correction for saturation is~99.4%and~88%respectively among 175 active regions.The advantages and disadvantages of the algorithm are discussed.
文摘Parkinson’s disease (PD) is one of the most common human neurodegenerative disorders caused by the loss of dopaminergic neurons in the brain. The α-synuclein (SNCA) gene is one of the most studied genes involved in the pathogenesis of PD. In our study, we conducted a genetic analysis of promoter and intron single-nucleotide polymorphisms (SNPs) in the SNCA gene. We also analyzed the association of genotypes of these SNPs with expression levels of SNCA mRNA. One of four SNPs in the SNCA gene, and the rs2736990 polymorphism, associates with the risk of the sporadic form of PD in Russian population. The risk of PD was increased almost twofold in carriers of allele C (odds ratios = 1.9, 95% confidence interval: 1.2-2.91, p = 0.003). However, no association was found between any of the genotypes of SNPs tested (rs2583988, rs2619363, rs2619364 and rs2736990) and alterations in SNCA levels. Our findings support the hypothesis that the rs2736990 polymorphism is associated with PD. SNPs rs2583988, rs2619363 and rs2619364 in the promoter region of the SNCA gene themselves do not significantly influence the expression of SNCA. Most likely, SNCA gene expression is a very complex process that is affected by different genetic and epigenetic factors.
文摘This work presents the results of complex gravity observation performed at Shults Cape, Gamov peninsula (42.58°N, 131.15°E), Russia. Absolute laser gravimeter GABL type and Scintrex type relative gravimeter were used for measurement. To investigate the accuracy of tidal corrections we compared the observed tidal parameters of the main tidal waves O1 and M2 with modeled ones computed from 6 different ocean tidal models: CSR4, FES02, FES04, GOT00, NAO99 and TPX06. After discussion a theoretical model based on TPX06 ocean tides model and DDW99 non hydrostatic body tides model was used for tidal correction of absolute gravity data. Preliminary estimate of gravity effect induced by the Tohoku-Oki earthquake of11 March 2011Mw = 9.0 at Primorye territory (Russia) was found to be 5.1 ± 2.0 μGal. Co-seismic crustal displacements revealed by GPS data at Far EastRussiacontinental coast are also investigated. Volumetric dilatation of this area is observed at +1.7 × 10-8 level.
基金supported by the A3 Foresight Program“Modeling and Computation of Applied Inverse Problems”Japan Society for the Promotion of Science(JSPS)+5 种基金National Natural Science Foundation of China(NSFC)supported by NSFC(No.11971121)partially supported by JSPS KAKENHI Grant Number JP15H05740supported by NSFC(No.11771270)partly supported by NSFC(No.91730303)RUDN University Program5-100。
文摘In this paper,we establish a novel unique continuation property for two-dimensional anisotropic elasticity systems with partial information.More precisely,given a homogeneous elasticity system in a connected open bounded domain,we investigate the unique continuation by assuming only the vanishing of one component of the solution in a subdomain.Using the corresponding Riemann function,we prove that the solution vanishes in the whole domain provided that the other component vanishes at one point up to its second derivatives.Further,we construct several examples showing the possibility of further reducing the additional information of the other component.This result possesses remarkable significance in both theoretical and practical aspects because the required data are almost halved for the unique determination of the whole solution.
文摘The influence of intergalactic magnetic fields on the strong gravitational lensing of blazar secondary gamma radiation is discussed.Currently,two cases of strong gravitational lensing of blazar gamma-radiation are known,where radiation is deflected by galaxies on the line of sight between the blazars and Earth.The magnetic field can affect the movements of electron-positron pairs generated by primary radiation,thereby changing the directions of secondary gamma radiation.It modifies the equation of the gravitational lens and leads to the dependence of the observed signal in the secondary gamma radiation on the energy of photons and magnetic field.Accordingly,it is possible,in principle,to estimate the intergalactic magnetic fields from the time delay of signals,from the angular position of images(for future high-resolution gamma-ray telescopes)or from the shape of the observed energy spectrum.This method is demonstrated by the example of the blazar B0218+357.In this case,however,it is not possible to obtain useful constraints due to the large distances to the blazar and lens galaxy.The result is only a lower limit on the magnetic field B>2×10^(−17)G,which is weaker than other existing constraints.However,future discoveries of lensed blazars may provide more favorable opportunities for measuring the magnetic fields,especially with the help of a new generation of gamma-ray telescopes such as e-ASTROGAM,GECAM,and SVOM as well as future gamma-ray telescopes with a high angular resolution,∼0.1″.
文摘Du 15 au 16 septembre 2022,la 22^(e)réunion du Conseil des chefs d’État des pays membres de l’Organisation de coopération de Shanghai(OCS)s'est tenue à Samarcande en Ouzbékistan.Au cours du Sommet,les chefs d'Élats ont eu des discussions en petit comité,cl ceux de tous les pays participants ont conjointement tenu des discussions en assemblée.
文摘Correction to:Radiation Detection Technology and Methods(2024)8:1-1105.https://doi.org/10.1007/s41605-024-00463-y.In this article all authors name was missing in the springer link.It has been corrected.The original article has been corrected.
