The typology of Ptolemaic royal sculpture has served as a theme of research for a number of scholars who have managed to achieve impressive results:two fundamental works must be mentioned.The earlier is Bildnisse der ...The typology of Ptolemaic royal sculpture has served as a theme of research for a number of scholars who have managed to achieve impressive results:two fundamental works must be mentioned.The earlier is Bildnisse der Ptolemaer by H.Kyrieleis,which established a convincing correspondence between the well-attributed images of the Ptolemaic kings on their coins and their mostly uninscribed sculpted images.'The history of the research reveals that although the corpus of Ptolemaic sculpture gradually expanded,due to new finds and new publications,challenges to specific attributions proposed by Kyrieleis often proved to be a failure?A later work deserving a special mention is Portraits of the Ptolemies by P.E.Stanwick,which proposed a well-founded scheme for the evolution of the Ptolemaic royal sculpture dividing it into nine groups(Groups A-E,G making a chronological sequence,Groups F,H-J uncertain and miscellaneous)'Quite expectedly,a problematic issue is the ultimate motive and final result of shifting from one such group to another:a grouping of objects is largely a formal task,and a scholar performing it is unlikely to concentrate simultaneously on the variety of political,ideological,and religious factors that could lie behind the emergence of the groups indicated.The present article aims to offer a tentative explanation for the shift in the style of Ptolemaic sculpture that took place at the cusp of the 3rd and 2nd centuries BC,i.e.,the transition between Stanwick's "Group A"and "Group B."展开更多
The work deals with the epitaxial PbSe layers grown on the KCl substrates by the method of “hot-wall” molecular epitaxy over the range of layer thicknesses of 20 - 2000 nm. Special emphasis is put on the values of e...The work deals with the epitaxial PbSe layers grown on the KCl substrates by the method of “hot-wall” molecular epitaxy over the range of layer thicknesses of 20 - 2000 nm. Special emphasis is put on the values of elastic deformations that could be generated and frozen in epitaxial layers with the aim of influencing their energy spectra and optical properties. The maximum deformation at layers tension made up 57% of the initial mismatch between the layer and the substrate (ε = Δa/a = 0.015). In such a solid-state structure effective “negative” pressure is realized, which is justified by increase in the tangential lattice constant and the forbidden gap width. This width correlates with the tangential lattice constant (deformation) and corresponds to certain values of definite frequencies of direct electron transitions across the forbidden gap.展开更多
At present, there is no method for identifying meat frozen in a thermal state acceptable for production control. The role of free nucleotides in the processes of refrigeration and storage of meat, affecting the struct...At present, there is no method for identifying meat frozen in a thermal state acceptable for production control. The role of free nucleotides in the processes of refrigeration and storage of meat, affecting the structural and mechanical properties of muscle tissue, the formation of taste and its biological value is known. In this article we compared methods for identifying the thermal state of meat based on the determination of the composition and content of free nucleotides by high-performance liquid chromatography (HPLC) and spectrophotometry [SF]. High-purity reference substances were used: free nucleotides—ATP, ADP, AMP, IMP and nucleosides-inosine and hypoxanthine. It has been experimentally established that the characteristic peaks of the absorption spectra for extracts of free nucleotides of meat frozen depended from thermal state of meat. The content of ATP is 21.8 times higher in meat frozen in a fresh state, and the amount of IMF is 12.3 times lower than in meat frozen after cooling. The results of studies of meat frozen using the HPLC method and the developed SF method show the adequacy of the data obtained by both methods. SF-method based on the determination of the optical density of the extracts of free nucleotides is recommended to justify the choice of technological process meat defrost modes.展开更多
描述并绘制了越南唇形科一新属及新种:日轮果属(Heliacria Bo Li,C.L.Xiang,T.S.Hoang&Nuraliev)和日轮果(H.maritima Bo Li,C.L.Xiang,T.S.Hoang&Nuraliev)。日轮果属因具攀援藤本习性,花大且花冠为纯白色,花萼近辐射对称、5...描述并绘制了越南唇形科一新属及新种:日轮果属(Heliacria Bo Li,C.L.Xiang,T.S.Hoang&Nuraliev)和日轮果(H.maritima Bo Li,C.L.Xiang,T.S.Hoang&Nuraliev)。日轮果属因具攀援藤本习性,花大且花冠为纯白色,花萼近辐射对称、5深裂、裂片长且在果期增大并开展,果实顶端具放射状的瘤状突起等特征而明显区别于黄芩亚科的其他5属。目前,该属仅发现于越南东南部沿海的平定省、富安省、庆和省和宁顺省,常生于海岸边干旱的低地矮林中。展开更多
BACKGROUND Esophageal squamous cell carcinoma(ESCC)is causing a high mortality rate due to the lack of efficient early prognosis markers and suitable therapeutic regimens.The prognostic role of genes responsible for t...BACKGROUND Esophageal squamous cell carcinoma(ESCC)is causing a high mortality rate due to the lack of efficient early prognosis markers and suitable therapeutic regimens.The prognostic role of genes responsible for the acquisition of radioresistance in ESCC has not been fully elucidated.AIM To establish a prognostic model by studying gene expression patterns pertinent to radioresistance in ESCC patients.METHODS Datasets were obtained from the Gene Expression Omnibus and The Cancer Genome Atlas databases.The edgeR,a Bioconductor package,was used to analyze mRNA expression between different groups.We screened genes specifically responsible for radioresistance to estimate overall survival.Pearson correlation analysis was performed to confirm whether the expression of those genes correlated with each other.Genes contributing to radioresistance and overall survival were assessed by the multivariate Cox regression model through the calculation ofβi and risk score using the following formula:∑^(n)_(i=1)βi×PSI.RESULTS We identified three prognostic mRNAs(cathepsin S[CTSS],cluster of differentiation 180[CD180],and SLP adapter and CSK-interacting membrane protein[SCIMP])indicative of radioresistance.The expression of the three identified mRNAs was related to each other(r>0.70 and P<0.05).As to 1-year and 3-year overall survival prediction,the area under the time-dependent receiver operating characteristic curve of the signature consisting of the three mRNAs was 0.716 and 0.841,respectively.When stratifying patients based on the risk score derived from the signature,the high-risk group exhibited a higher death risk and shorter survival time than the low-risk group(P<0.0001).Overall survival of the low-risk patients was significantly better than that of the highrisk patients(P=0.018).CONCLUSION We have developed a novel three-gene prognostic signature consisting of CTSS,CD180,and SCIMO for ESCC,which may facilitate the prediction of early prognosis of this malignancy.展开更多
A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed...A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 rain. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.展开更多
The features of JAK-STAT signaling in liver cells are discussed in the current review. The role of this signaling cascade in carcinogenesis is accentuated. The possible involvement of this pathway and alteration of it...The features of JAK-STAT signaling in liver cells are discussed in the current review. The role of this signaling cascade in carcinogenesis is accentuated. The possible involvement of this pathway and alteration of its elements are compared for normal cholangiocytes, cholangiocarcinoma predisposition and development. Prolactin and interleukin-6 are described in detail as the best studied examples. In addition, the non-classical nuclear translocation of cytokine receptors is discussed in terms of its possible implication to cholangiocarcinoma development.展开更多
Hepatocellular carcinoma(HCC) is one of the most prevalent malignancies worldwide and the second leading cause of death among all cancer types. Deregulation of the networks of tissue-specific transcription factors(TFs...Hepatocellular carcinoma(HCC) is one of the most prevalent malignancies worldwide and the second leading cause of death among all cancer types. Deregulation of the networks of tissue-specific transcription factors(TFs) observed in HCC leads to profound changes in the hepatic transcriptional program that facilitates tumor progression. In addition, recent reports suggest that substantial aberrations in the production of TF isoforms occur in HCC. In vitro experiments have identified distinct isoform-specific regulatory functions and related biological effects of liver-specific TFs that are implicated in carcinogenesis, which may be relevant for tumor progression and clinical outcome. This study reviews available data on the expression of isoforms of liver-specific and ubiquitous TFs in the liver and HCC and their effects, including HNF4α, C/EBPs, p73 and TCF7 L2, and indicates that assessment of the ratio of isoforms and targeting specific TF variants may be beneficial for the prognosis and treatment of HCC.展开更多
New source of light emission of high energy is found due to arising of instability in supersonic jets. These phenomena are observed in gas jets flowing from the nozzle with a central cone. It leads to high acceleratio...New source of light emission of high energy is found due to arising of instability in supersonic jets. These phenomena are observed in gas jets flowing from the nozzle with a central cone. It leads to high accelerations of the molecules, ions and elementary particles. The emission spectra of the jets are obtained. Decoding of the spectra allowed us to define inverted population of rotational and vibrational levels, electrons temperature, rotational and vibrational temperatures for molecular ions. Internal energy decreasing provides the instability and gas volume decreasing due to internal forces;super-compressibility is result of it;its produce high density of light energy emission in various continuous media.展开更多
The data referring to the mechanism and efficiency of electronically excited macroradical and radical anionreactions, the important role of photochemical chain reactions in polymers are presented, It was found that by...The data referring to the mechanism and efficiency of electronically excited macroradical and radical anionreactions, the important role of photochemical chain reactions in polymers are presented, It was found that by varying photonenergy, temperature, photolysis time and competition between thermal and photochemical reactions, it is possible to change the functional composition and molecular weight distribution of polymers.展开更多
Mesenchymal stem cells(MSCs)are stromal multipotent stem cells that can differentiate into multiple cell types,including fibroblasts,osteoblasts,chondrocytes,adipocytes,and myoblasts,thus allowing them to contribute t...Mesenchymal stem cells(MSCs)are stromal multipotent stem cells that can differentiate into multiple cell types,including fibroblasts,osteoblasts,chondrocytes,adipocytes,and myoblasts,thus allowing them to contribute to the regeneration of various tissues,especially bone tissue.MSCs are now considered one of the most promising cell types in the field of tissue engineering.Traditional petri dish-based culture of MSCs generate heterogeneity,which leads to inconsistent efficacy of MSC applications.Biodegradable and biocompatible polymers,poly(3-hydroxyalkanoates)(PHAs),are actively used for the manufacture of scaffolds that serve as carriers for MSC growth.The growth and differentiation of MSCs grown on PHA scaffolds depend on the physicochemical properties of the polymers,the 3D and surface microstructure of the scaffolds,and the biological activity of PHAs,which was discovered in a series of investigations.The mechanisms of the biological activity of PHAs in relation to MSCs remain insufficiently studied.We suggest that this effect on MSCs could be associated with the natural properties of bacteria-derived PHAs,especially the most widespread representative poly(3-hydroxybutyrate)(PHB).This biopolymer is present in the bacteria of mammalian microbiota,whereas endogenous poly(3-hydroxybutyrate)is found in mammalian tissues.The possible association of PHA effects on MSCs with various biological functions of poly(3-hydroxybutyrate)in bacteria and eukaryotes,including in humans,is discussed in this paper.展开更多
Wind speed extremes in the sub-Arctic realm of the North-East Pacific region were investigated through extreme value analysis of wind speed obtained from wind simulations of the COSMO-CLM (Consortium for Small-scale M...Wind speed extremes in the sub-Arctic realm of the North-East Pacific region were investigated through extreme value analysis of wind speed obtained from wind simulations of the COSMO-CLM (Consortium for Small-scale Modelling, climate version) mesoscale model, as well as using observed data. The analysis showed that the set of wind speed extremes obtained from observations is a mixture of two different subsets each neatly described by the Weibull distribution. Using special metaphoric terminology, they are labelled as “Black Swans” and “Dragons”. The “Dragons” are responsible for strongest extremes. It has been shown that both reanalysis and GCM (general circulation model) data have no “Dragons”. This means that such models underestimate wind speed maxima, and the important circulation process generating the anomalies is not simulated. The COSMO-CLM data have both “Black Swans” and “Dragons”. This evidence provides a clue that an atmospheric model with a detailed spatial resolution (we used in this work the data from domain with 13.2 km spatial resolution) does reproduce the special mechanism responsible for the generation of the largest wind speed extremes. However, a more thorough analysis shows that the differences in the parameters of the cumulative distribution functions are still significant. The ratio between the modelled Dragons and Black Swans can reach up to only 10%. It is much less than 30%, which was the level established for observations.展开更多
Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells(QWs) with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-con...Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells(QWs) with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-consistent k·p Hamiltonian, taking into account valence band mixing and the strain effect. Our calculations show that the M-shaped type-Ⅱ QWs are a promising structure for making 1.3 um lasers at room temperature because they can easily be used to obtain 1.3 um for photoluminescence with a proper thickness and have large wave-function overlap for high optical gain.展开更多
Introduction of controllable deformations into periodic materials that lead to disclinations in their structure opens novel routes for construction of higher-order topological insulators hosting topological states at ...Introduction of controllable deformations into periodic materials that lead to disclinations in their structure opens novel routes for construction of higher-order topological insulators hosting topological states at disclinations.Appearance of these topological states is consistent with the bulk-disclination correspondence principle,and is due to the filling anomaly that results in fractional charges to the boundary unit cells.So far,topological disclination states were observed only in the linear regime,while the interplay between nonlinearity and topology in the systems with disclinations has been never studied experimentally.We report here on the experimental observation of the nonlinear photonic disclination states in waveguide arrays with pentagonal or heptagonal disclination cores inscribed in transparent optical medium using the fs-laser writing technique.The transition between nontopological and topological phases in such structures is controlled by the Kekulédistortion coefficient r with topological phase hosting simultaneously disclination states at the inner disclination core and spatially separated from them corner-I,corner-II,and extended edge states at the outer edge of the structure.We show that the robust nonlinear disclination states bifurcate from their linear counterparts and that location of their propagation constants in the gap and,hence,their spatial localization can be controlled by their power.Nonlinear disclination states can be efficiently excited by Gaussian input beams,but only if they are focused into the waveguides belonging to the disclination core,where such topological states reside.Our results open new prospects for investigation of nonlinear effects in topological systems with disclinations and are relevant for different areas of science,including Bose-Einstein and polariton condensates,where potentials with the disclinations can be created.展开更多
基金sponsored by the Russian Science Foundation,project no.19-18-00369,The Classical Orient:culture,world-view,tradition of research in Russia(based on the monuments in the collection of the Pushkin Museum of Fine Arts and archive sources)."。
文摘The typology of Ptolemaic royal sculpture has served as a theme of research for a number of scholars who have managed to achieve impressive results:two fundamental works must be mentioned.The earlier is Bildnisse der Ptolemaer by H.Kyrieleis,which established a convincing correspondence between the well-attributed images of the Ptolemaic kings on their coins and their mostly uninscribed sculpted images.'The history of the research reveals that although the corpus of Ptolemaic sculpture gradually expanded,due to new finds and new publications,challenges to specific attributions proposed by Kyrieleis often proved to be a failure?A later work deserving a special mention is Portraits of the Ptolemies by P.E.Stanwick,which proposed a well-founded scheme for the evolution of the Ptolemaic royal sculpture dividing it into nine groups(Groups A-E,G making a chronological sequence,Groups F,H-J uncertain and miscellaneous)'Quite expectedly,a problematic issue is the ultimate motive and final result of shifting from one such group to another:a grouping of objects is largely a formal task,and a scholar performing it is unlikely to concentrate simultaneously on the variety of political,ideological,and religious factors that could lie behind the emergence of the groups indicated.The present article aims to offer a tentative explanation for the shift in the style of Ptolemaic sculpture that took place at the cusp of the 3rd and 2nd centuries BC,i.e.,the transition between Stanwick's "Group A"and "Group B."
文摘The work deals with the epitaxial PbSe layers grown on the KCl substrates by the method of “hot-wall” molecular epitaxy over the range of layer thicknesses of 20 - 2000 nm. Special emphasis is put on the values of elastic deformations that could be generated and frozen in epitaxial layers with the aim of influencing their energy spectra and optical properties. The maximum deformation at layers tension made up 57% of the initial mismatch between the layer and the substrate (ε = Δa/a = 0.015). In such a solid-state structure effective “negative” pressure is realized, which is justified by increase in the tangential lattice constant and the forbidden gap width. This width correlates with the tangential lattice constant (deformation) and corresponds to certain values of definite frequencies of direct electron transitions across the forbidden gap.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50372007 and 50572007, Russian Fund for Basic Research under Grant Nos 06-02-39031 and 07-03-00956, and Belarus Republic Foundation for Basic Research under Grant No F05-281.
文摘在 dcarc 喷气和微波血浆化学药品蒸汽免职种的多晶的钻石电影的电子旋转回声(ESR ) 被学习。有直到 8 x 10 的氮杂质集中(18 ) 的电影厘米(-3) 被拉曼,阴极射线发光和光吸收也描绘系列。从有 2.0024 的 g 因素(在钻石格子的氮杂质原子占据 C 地点) 的 P1 中心的 ESR 信号被发现与在一个 H-102 共鸣器增加微波力量展出倒置。当微波激射的媒介在房间温度操作了,旋转倒置效果能具有为做 N 的钻石的进一步的考虑的兴趣。
文摘At present, there is no method for identifying meat frozen in a thermal state acceptable for production control. The role of free nucleotides in the processes of refrigeration and storage of meat, affecting the structural and mechanical properties of muscle tissue, the formation of taste and its biological value is known. In this article we compared methods for identifying the thermal state of meat based on the determination of the composition and content of free nucleotides by high-performance liquid chromatography (HPLC) and spectrophotometry [SF]. High-purity reference substances were used: free nucleotides—ATP, ADP, AMP, IMP and nucleosides-inosine and hypoxanthine. It has been experimentally established that the characteristic peaks of the absorption spectra for extracts of free nucleotides of meat frozen depended from thermal state of meat. The content of ATP is 21.8 times higher in meat frozen in a fresh state, and the amount of IMF is 12.3 times lower than in meat frozen after cooling. The results of studies of meat frozen using the HPLC method and the developed SF method show the adequacy of the data obtained by both methods. SF-method based on the determination of the optical density of the extracts of free nucleotides is recommended to justify the choice of technological process meat defrost modes.
基金国家自然科学基金项目(32160047)The Scientific Project of the State Order of the Government of Russian Federation to Lomonosov Moscow State University(121032500082-2)云南省基础研究计划重点项目(202001AS070016)资助。
文摘描述并绘制了越南唇形科一新属及新种:日轮果属(Heliacria Bo Li,C.L.Xiang,T.S.Hoang&Nuraliev)和日轮果(H.maritima Bo Li,C.L.Xiang,T.S.Hoang&Nuraliev)。日轮果属因具攀援藤本习性,花大且花冠为纯白色,花萼近辐射对称、5深裂、裂片长且在果期增大并开展,果实顶端具放射状的瘤状突起等特征而明显区别于黄芩亚科的其他5属。目前,该属仅发现于越南东南部沿海的平定省、富安省、庆和省和宁顺省,常生于海岸边干旱的低地矮林中。
文摘BACKGROUND Esophageal squamous cell carcinoma(ESCC)is causing a high mortality rate due to the lack of efficient early prognosis markers and suitable therapeutic regimens.The prognostic role of genes responsible for the acquisition of radioresistance in ESCC has not been fully elucidated.AIM To establish a prognostic model by studying gene expression patterns pertinent to radioresistance in ESCC patients.METHODS Datasets were obtained from the Gene Expression Omnibus and The Cancer Genome Atlas databases.The edgeR,a Bioconductor package,was used to analyze mRNA expression between different groups.We screened genes specifically responsible for radioresistance to estimate overall survival.Pearson correlation analysis was performed to confirm whether the expression of those genes correlated with each other.Genes contributing to radioresistance and overall survival were assessed by the multivariate Cox regression model through the calculation ofβi and risk score using the following formula:∑^(n)_(i=1)βi×PSI.RESULTS We identified three prognostic mRNAs(cathepsin S[CTSS],cluster of differentiation 180[CD180],and SLP adapter and CSK-interacting membrane protein[SCIMP])indicative of radioresistance.The expression of the three identified mRNAs was related to each other(r>0.70 and P<0.05).As to 1-year and 3-year overall survival prediction,the area under the time-dependent receiver operating characteristic curve of the signature consisting of the three mRNAs was 0.716 and 0.841,respectively.When stratifying patients based on the risk score derived from the signature,the high-risk group exhibited a higher death risk and shorter survival time than the low-risk group(P<0.0001).Overall survival of the low-risk patients was significantly better than that of the highrisk patients(P=0.018).CONCLUSION We have developed a novel three-gene prognostic signature consisting of CTSS,CD180,and SCIMO for ESCC,which may facilitate the prediction of early prognosis of this malignancy.
基金supported by grants from the International Science&Technology Cooperation Program of China(2009DFA32330)the Special Fund for Agro-scientific Research in the Public Interest(No.201203040)
文摘A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 rain. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.
文摘The features of JAK-STAT signaling in liver cells are discussed in the current review. The role of this signaling cascade in carcinogenesis is accentuated. The possible involvement of this pathway and alteration of its elements are compared for normal cholangiocytes, cholangiocarcinoma predisposition and development. Prolactin and interleukin-6 are described in detail as the best studied examples. In addition, the non-classical nuclear translocation of cytokine receptors is discussed in terms of its possible implication to cholangiocarcinoma development.
基金Supported by Russian Foundation for Basic Research,contract No.18-34-00816\18
文摘Hepatocellular carcinoma(HCC) is one of the most prevalent malignancies worldwide and the second leading cause of death among all cancer types. Deregulation of the networks of tissue-specific transcription factors(TFs) observed in HCC leads to profound changes in the hepatic transcriptional program that facilitates tumor progression. In addition, recent reports suggest that substantial aberrations in the production of TF isoforms occur in HCC. In vitro experiments have identified distinct isoform-specific regulatory functions and related biological effects of liver-specific TFs that are implicated in carcinogenesis, which may be relevant for tumor progression and clinical outcome. This study reviews available data on the expression of isoforms of liver-specific and ubiquitous TFs in the liver and HCC and their effects, including HNF4α, C/EBPs, p73 and TCF7 L2, and indicates that assessment of the ratio of isoforms and targeting specific TF variants may be beneficial for the prognosis and treatment of HCC.
文摘New source of light emission of high energy is found due to arising of instability in supersonic jets. These phenomena are observed in gas jets flowing from the nozzle with a central cone. It leads to high accelerations of the molecules, ions and elementary particles. The emission spectra of the jets are obtained. Decoding of the spectra allowed us to define inverted population of rotational and vibrational levels, electrons temperature, rotational and vibrational temperatures for molecular ions. Internal energy decreasing provides the instability and gas volume decreasing due to internal forces;super-compressibility is result of it;its produce high density of light energy emission in various continuous media.
基金This work was financially supported by Federal program "Integration" (Grant A0114).
文摘The data referring to the mechanism and efficiency of electronically excited macroradical and radical anionreactions, the important role of photochemical chain reactions in polymers are presented, It was found that by varying photonenergy, temperature, photolysis time and competition between thermal and photochemical reactions, it is possible to change the functional composition and molecular weight distribution of polymers.
基金Supported by Russian Science Foundation,No.17-74-20104
文摘Mesenchymal stem cells(MSCs)are stromal multipotent stem cells that can differentiate into multiple cell types,including fibroblasts,osteoblasts,chondrocytes,adipocytes,and myoblasts,thus allowing them to contribute to the regeneration of various tissues,especially bone tissue.MSCs are now considered one of the most promising cell types in the field of tissue engineering.Traditional petri dish-based culture of MSCs generate heterogeneity,which leads to inconsistent efficacy of MSC applications.Biodegradable and biocompatible polymers,poly(3-hydroxyalkanoates)(PHAs),are actively used for the manufacture of scaffolds that serve as carriers for MSC growth.The growth and differentiation of MSCs grown on PHA scaffolds depend on the physicochemical properties of the polymers,the 3D and surface microstructure of the scaffolds,and the biological activity of PHAs,which was discovered in a series of investigations.The mechanisms of the biological activity of PHAs in relation to MSCs remain insufficiently studied.We suggest that this effect on MSCs could be associated with the natural properties of bacteria-derived PHAs,especially the most widespread representative poly(3-hydroxybutyrate)(PHB).This biopolymer is present in the bacteria of mammalian microbiota,whereas endogenous poly(3-hydroxybutyrate)is found in mammalian tissues.The possible association of PHA effects on MSCs with various biological functions of poly(3-hydroxybutyrate)in bacteria and eukaryotes,including in humans,is discussed in this paper.
文摘Wind speed extremes in the sub-Arctic realm of the North-East Pacific region were investigated through extreme value analysis of wind speed obtained from wind simulations of the COSMO-CLM (Consortium for Small-scale Modelling, climate version) mesoscale model, as well as using observed data. The analysis showed that the set of wind speed extremes obtained from observations is a mixture of two different subsets each neatly described by the Weibull distribution. Using special metaphoric terminology, they are labelled as “Black Swans” and “Dragons”. The “Dragons” are responsible for strongest extremes. It has been shown that both reanalysis and GCM (general circulation model) data have no “Dragons”. This means that such models underestimate wind speed maxima, and the important circulation process generating the anomalies is not simulated. The COSMO-CLM data have both “Black Swans” and “Dragons”. This evidence provides a clue that an atmospheric model with a detailed spatial resolution (we used in this work the data from domain with 13.2 km spatial resolution) does reproduce the special mechanism responsible for the generation of the largest wind speed extremes. However, a more thorough analysis shows that the differences in the parameters of the cumulative distribution functions are still significant. The ratio between the modelled Dragons and Black Swans can reach up to only 10%. It is much less than 30%, which was the level established for observations.
基金Supported by the National Basic Research Program of China under Grant No 2014CB643902the Key Program of Natural Science Foundation of China under Grant No 61334004+3 种基金the National Natural Science Foundation of China under Grant No 61404152the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDA5-1the Foundation of National Laboratory for Infrared Physics,the Key Research Program of the Chinese Academy of Sciences under Grant No KGZDEW-804the Creative Research Group Project of Natural Science Foundation of China under Grant No 61321492
文摘Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells(QWs) with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-consistent k·p Hamiltonian, taking into account valence band mixing and the strain effect. Our calculations show that the M-shaped type-Ⅱ QWs are a promising structure for making 1.3 um lasers at room temperature because they can easily be used to obtain 1.3 um for photoluminescence with a proper thickness and have large wave-function overlap for high optical gain.
基金B.R.,H.W.and Y.Z.acknowledge funding by the National Natural Science Foundation of China(Grant No.:12074308)the Fundamental Research Funds for the Central Universities(Grant No.:xzy022022058)+2 种基金A.A.A.,Y.V.K.,S.A.Z.,N.N.S.,A.A.K.,V.O.K.,S.V.C.,and V.N.Z.acknowledge funding by the Russian Science Foundation grant 21-12-00096the research project FFUU2021-0003 of the Institute of Spectroscopy of the Russian Academy of Sciences.A.A.KS.P.K.are supported by the Ministry of Science and Higher Education of the Russian Federation on the basis of the FSAEIHE SUSU(NRU)(Agreement No.:075-15-2022-1116).
文摘Introduction of controllable deformations into periodic materials that lead to disclinations in their structure opens novel routes for construction of higher-order topological insulators hosting topological states at disclinations.Appearance of these topological states is consistent with the bulk-disclination correspondence principle,and is due to the filling anomaly that results in fractional charges to the boundary unit cells.So far,topological disclination states were observed only in the linear regime,while the interplay between nonlinearity and topology in the systems with disclinations has been never studied experimentally.We report here on the experimental observation of the nonlinear photonic disclination states in waveguide arrays with pentagonal or heptagonal disclination cores inscribed in transparent optical medium using the fs-laser writing technique.The transition between nontopological and topological phases in such structures is controlled by the Kekulédistortion coefficient r with topological phase hosting simultaneously disclination states at the inner disclination core and spatially separated from them corner-I,corner-II,and extended edge states at the outer edge of the structure.We show that the robust nonlinear disclination states bifurcate from their linear counterparts and that location of their propagation constants in the gap and,hence,their spatial localization can be controlled by their power.Nonlinear disclination states can be efficiently excited by Gaussian input beams,but only if they are focused into the waveguides belonging to the disclination core,where such topological states reside.Our results open new prospects for investigation of nonlinear effects in topological systems with disclinations and are relevant for different areas of science,including Bose-Einstein and polariton condensates,where potentials with the disclinations can be created.