Pure fraction (92%-95%) of phagocytes (FP) and a mixture of amoebocytes(62%) and morula cells (38 %) FPMC of the holothurian Eupentacta fraudatrix (Holothuroidea, Dendrochirota) were obtained by using ficoll verograph...Pure fraction (92%-95%) of phagocytes (FP) and a mixture of amoebocytes(62%) and morula cells (38 %) FPMC of the holothurian Eupentacta fraudatrix (Holothuroidea, Dendrochirota) were obtained by using ficoll verographine step gradient. Basal production of reactive oxygen species (ROS) in FP quantified by using reduction of nitroblue tetrazolium (NBT) was more than twice that in FPMC. Thermostable toxin of Yersinia pseudotuberculosis (TST) at different concentrations ( 0.2; 0.5; 2.5 μg/ml, but not 0.1 μg/ml) stimulated NBT reduction in FPMC after 24 h incubation. In FP, TST at concentrations of 0.1 and 0.2 μg/ml inhibited and at concentrations of 0.5 and 2.5 μg/ml stimulated NBT reduction after 24 h incubation. Maximal effect was observed in FP and FPMC at TST concentrations of 0.5 and 0.2 μg/ml, respectively. Addition of catalase (0.7 μg/ml) to the cells treated with TST (2.5 μg/ml) was followed by a decrease in NBT reduction compared to that under toxin treatment alone. TST stimulated superoxide dismutase activity in concentration dependent manner (maximum at 0.5 μg/ml concentration in FP) after 24 h treatment, and this stimulation was prevented by a commercial catalase. Plant lectin concanavalin A stimulated NBT reduction more than 5 fold in FPMC compared to the control. With addition of TST, lectin stimulated ROS to lesser extent than that with lectin alone. When catalase, TST, and lectin were added into the FPMC simultaneously, ROS increase was similar to that under lectin treatment alone. On the whole, data obtained indicated that ROS generation in holothurian coelomocytes especially occurs in both stimulated and not stimulated phagocytes, and that changes in ROS production by these cells may be one of the mechanisms of antibacterial protection of holothurians.展开更多
Free and initiated by 0.9% sodium chloride solution yielding of crystals was studied in the urine of the 35 healthy people. The metabolites—sodium lactate and sodium pyruvate—were superinduced into the dryable biolo...Free and initiated by 0.9% sodium chloride solution yielding of crystals was studied in the urine of the 35 healthy people. The metabolites—sodium lactate and sodium pyruvate—were superinduced into the dryable biological system in the increasing physiological concentrations. Regularities of the neogenic mixtures’ crystallization were revealed according to the metabolites dose. We showed the antagonistic tendencies in the parameters’ change at the increasing concentrations of the different metabolites—substratum of the enzyme’s opposite reactions—relying on the comparative estimation of the crystalloscopical and tezigraphical indices’ dynamics. Our own data and literature information brought us to a new conception of the biofluid’s stability as a crystallogenetic solution. According to it any substance injected into a dehydrated biological system proves to be a stabilizing or destabilizing agent which leads to a significant reorganization of the biocrystallogenesis. This phenomenon may cause a development of a management strategy of the biological crystallogenesis processes.展开更多
In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatm...In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for Mg（OH）2 precipitation was demonstrated. In this study, crystalline Mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （Mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that Mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg（OH）2 are 30-265 nm length or width.展开更多
TiO2 compounds possess relatively high adsorption abilities and exhibit high photocatalytic activities that exhibit potential for the destruction of organic pollutants in natural and waste waters.Nanostructured potass...TiO2 compounds possess relatively high adsorption abilities and exhibit high photocatalytic activities that exhibit potential for the destruction of organic pollutants in natural and waste waters.Nanostructured potassium polytitanates modified using transition metals and their oxides/hydroxides generate new nanomaterials that operate in the visible spectral range.This study presents the synthesis and investigation of the structure,composition and photocatalytic activity of powdered nanoscale quasi-amorphous potassium polytitanates particles modified with iron,zinc,copper,cobalt and nickel sulfate in aqueous solutions.All of the powders investigated in this work exhibit a high adsorption capacity for methylene blue dye（15-20mg/g） related to the welldeveloped surface of the layered potassium polytitanate particles.Introducing transition metals and their oxides/hydroxides influences the electronic structure of the obtained systems.A high photocatalytic activity was observed for systems containing iron,zinc,nickel and their oxides/hydroxides in the ultraviolet and visible ranges.展开更多
Ammonia has been considered as a novel fuel for decarbonization purposes.However,emissions from combustion systems are still posing a problem.Therefore,experimental and numerical simulations have been conducted to stu...Ammonia has been considered as a novel fuel for decarbonization purposes.However,emissions from combustion systems are still posing a problem.Therefore,experimental and numerical simulations have been conducted to study the concentration of exhaust emissions(Nitric oxide“NO”,Nitrous oxide“N_(2)O”)from burning the ammonia/hydrogen(NH_(3)/H_(2))blend 85/15(vol%).The effects were measured at various thermal powers ranging 10 to 20 kW and with different Reynolds numbers from 20,000—40,000.The experimental points were numerically investigated in the Ansys CHEMKIN-Pro environment employing seven chemical kinetic mechanisms taken from the literature.All experiments have been undertaken at standard atmospheric conditions.The experimental results showed that both NO and N_(2)O gradually increased when the Reynolds number increased from 20,000 to 40,000.Along with that,the concentration of NO emissions at the exhaust reported minimum level when the Re=20,000 due to lower reactivity radical formation,all that led to a deterioration of the flame characteristics.Also,the integrated radical intensities of NO*,OH*,NH*,and NH_(2)*demonstrate an increasing trend as Re increased from 20,000 to 40,000.In terms of thermal power,N_(2)O suffered an abrupt decrease when the thermal power increased up to 15 kW,while the opposite occurs for NO.In addition,the radicals intensity of OH*,NH*and NH_(2)*figures show an increase in their concentration when the thermal power increased up to 15 kW then decreased with increasing thermal intensity to reach 20 kW,reflecting into increased NO productions and decreased N_(2)O levels.The numerical analysis showed that Stagni,Bertolino,and Bowen Mei were the most accurate mechanisms as these give a good prediction for NO and N_(2)O.The study also showed that the chemical reaction(HNO+O_(2)←→NO+HO_(2))is the main source of NO formation.While the chemical reaction(NH+NO←→N_(2)O+H)is responsible for the formation of N_(2)O by consuming NO and when there will be abundance in NH radicals.F展开更多
We have determined new statistical relations to estimate the fundamental atmospheric parameters of effective temperature and surface gravity,using MK spectral classification,and vice versa.The relations were construct...We have determined new statistical relations to estimate the fundamental atmospheric parameters of effective temperature and surface gravity,using MK spectral classification,and vice versa.The relations were constructed based on the published calibration tables(for main sequence stars)and observational data from stellar spectral atlases(for giants and supergiants).These new relations were applied to field giants with known atmospheric parameters,and the results of the comparison of our estimations with available spectral classification have been quite satisfactory.展开更多
BACKGROUND Fractures of the proximal femur epiphysis are problematic for state health care because they are associated with severe medical and social problems and high morbidity and mortality rates.AIM To model the po...BACKGROUND Fractures of the proximal femur epiphysis are problematic for state health care because they are associated with severe medical and social problems and high morbidity and mortality rates.AIM To model the potential risk of hip fracture via femur geometric parameters.METHODS Seventy educational cadaveric femurs from people aged 14 to 80 years,10 X-ray images from the records of the Human Anatomy Department and 10 X-ray images from the Department of Traumatology,Orthopedics and Disaster Surgery of Sechenov University,were evaluated.The parameters of the fractured bone were measured using images captured with a Canon d60 camera.The projection values of the proximal epiphysis of the cadaveric femurs and geometric parameters of the bones shown in the X-ray images were measured with Autodesk software(AutoCAD 2018).Analysis of the video frames showing bone rotation reveal that the greater trochanter can be inscribed in a parallelepiped,where one of the faces is parallel to the plane of view in the frontal standard projection and is rectangular.The angle of bone rotation obtained by turning the cube corresponded to the angle measured with the second technique.This reliable method of calculating the rotation of the bone relative to the anterior projection was employed in subsequent calculations.The geometric parameters of the femur were measured using X-ray images according to the proposed method.RESULTS The geometric parameters of 70 femurs were analyzed,and correlation coefficients were calculated.Our measurement results were compared with those reported by other authors.The potential influence of femur geometry on force distribution in the proximal epiphysis of the femur was described,and a 2-dimensional model of the femur epiphysis associated with minimal neck fracture risk was provided.The assessment of the geometric parameters of the femoral epiphysis indicated the greatest risk of a varus fracture of the neck if the angle of the minimal resistance zone(AMRZ)index>24°and the neck-shaft angle(NSA)<127.5°.展开更多
It is known that cytoskeleton-dependent trafficking of cell wall and membrane components to apical plasma membrane （PM） coupled with ion transport across pollen PM is crucial for maintaining polar pollen tube growth...It is known that cytoskeleton-dependent trafficking of cell wall and membrane components to apical plasma membrane （PM） coupled with ion transport across pollen PM is crucial for maintaining polar pollen tube growth. To elucidate whether plant hormones are involved in these processes, the effects of exogenous phytohormones, indole-3-acetic acid （IAA）, abscisic acid （ABA）, gibberellin A3 （GA3） and cytokinin （kinetin） on the growth, PM polarization, actin cytoskeleton （AC） organization and cytoplasmic pH （pile） of in vitro 4 h-growing petunia pollen tubes were investigated. IAA, ABA and GA3 displayed the growth-stimulating effects and these were accompanied by orthovanadate-sensitive hyperpolarization of the PM. Fluorescent labeling the enzyme with H＋-ATPase antibodies exhibited IAA- and ABA-induced lateral PM redistribution of it into the subapical zone of pollen tube PM. Pollen cultivation on the medium with latrunculin B, the inhibitor of actin polymerization, resulted in inhibition of pollen tube growth and simultaneously in the drop of endogenous IAA content. The IAA-growth stimulating effect was correlated with increased content of actin filaments （AF） in both apical and subapical zones of tubes, while ABA and GA3 exerted the same effect but it was accompanied by redistributing F-actin only to apical zone. In contrast, kinetin decreased the total F-actin content and inhibited pollen tube growth. It has been shown that the pHe of growing pollen tubes is sensitive to the plant hormones. In the case of male gametophyte growing for 1, 2 and 4 h, IAA induced alkalinization of the cytosol, while ABA and GA3 exerted qualitatively similar effect only after its growth for 1 h and 4 h, respectively. Kinetin, in contrast, resulted in acidification of the cytosol. All these results, taken together, indicate, for the first time, potential targets of the phytohormone action in pollen tubes.展开更多
For safe development of underground space and especially in areas of geological infringements it is necessary to creat effective system of tracking, forecasting and management for deforming processes in such areas-sys...For safe development of underground space and especially in areas of geological infringements it is necessary to creat effective system of tracking, forecasting and management for deforming processes in such areas-system of geomechanical monitoring. Besides it is necessary to study and imagine the internal mechanism of deforming processes in such special zones. In the paper some basic aspects of creation of geomechanical monitoring systems for realization of supervision, study and modelling of deforming processes, for modelling and study of the stress-strain state of massif in areas of large-scale underground mining works in view of a block-hierarchical structure of rock’s massive (presence of geological infringements) are considered. In particular such important tasks, as research of deforming processes in areas of geological infringements with the help of GPS-technologies and use of the received results for the modeling; construction of models adequately describing a condition of rock’s massive in area of geological infringement. Some results of researches on study of cavities influence on occurrence of an area of limiting conditions in region of geological infringement and possible shift along infringement are submitted.展开更多
The Binary star DataBase(BDB, http://bdb.inasan.ru) combines data from catalogs of binary and multiple stars of all observational types. There is a number of ways for variable stars to form or to be a part of binary o...The Binary star DataBase(BDB, http://bdb.inasan.ru) combines data from catalogs of binary and multiple stars of all observational types. There is a number of ways for variable stars to form or to be a part of binary or multiple systems. We describe how such stars are represented in the database.展开更多
Plant nonspecific lipid transfer proteins (nsLTPs) are widely distributed through plant kingdom and are characterized by the presence of a central hydrophobic cavity, suitable for binding various hydrophobic molecules...Plant nonspecific lipid transfer proteins (nsLTPs) are widely distributed through plant kingdom and are characterized by the presence of a central hydrophobic cavity, suitable for binding various hydrophobic molecules. Despite extensive research on nsLTP in different plant species, mostly angiosperm, and the great diversity of physiological processes in which they seem to be involved, their exact functions still remain unclear. Also, very limited experimental data are available on nsLTP in gymnosperm. In this study, we report for the first time on the molecular cloning of nsLTP, from Pinus sylvestris L.(PsLTP1, GenBank accession JN980402.1) and the expression pattern of PsLTP1 during ontogenesis and in response to environmental stress conditions. Total RNA from roots of 7-day old pine seedlings was used to isolate the cDNA clone, corresponding to Scots pine lipid transfer protein. The open reading frame of PsLTP1 consists of 372 bp encoding a protein of 123 amino acids. Amino acid sequence alignment revealed that mature PsLTP1 shares high level of similarity with nsLTP from other conifers and with well-studied nsLTPs from angiosperms. The PsLTP1 contains a 27-amino-acid N-terminal signal sequence and presents all the features of a plant nsLTP. Amino acid comparison analysis and 3D structure prediction showed that PsLTP1 is a type 1 nsLTP. The results of the expression analysis of Scots pine PsLTP1 gene revealed that its transcripts accumulate in actively growing tissues. Furthermore, transcription of PsLTP1 was upregulated in response to cold and salt treatments, and downregulated during acidic, osmotic and water stresses.展开更多
In this paper,we study such polyadic analog of an identity of a group asm-neutral sequence.In particular,we prove that all Post's equivalence classes of thefree covering group of any n-ary group[where n=k(m-1)+1 a...In this paper,we study such polyadic analog of an identity of a group asm-neutral sequence.In particular,we prove that all Post's equivalence classes of thefree covering group of any n-ary group[where n=k(m-1)+1 and k≥1]definedby m-neutral sequences form the(k+1)-ary group,which is isomorphic to the n-arysubgroup of all identities of the n-ary group in the case when m=2.展开更多
Two sublines of microalgae Dunaliella viridis Teodor. were obtained: CuS—a subline sensitive to toxic concentration of copper ions and CuR—a subline resistant to toxic concentration of copper ions. The chronological...Two sublines of microalgae Dunaliella viridis Teodor. were obtained: CuS—a subline sensitive to toxic concentration of copper ions and CuR—a subline resistant to toxic concentration of copper ions. The chronological aging of cultures was revealed in increase of DNA (polyploidization) and triacylglycerols (TAG) content in microalgae cells. The adaptation of D. viridis to toxic concentrations of copper ions resulted in formation of an adaptive epygenotype characterized by increased content of carbonylated proteins and decreased content of proline compared to the CuS-subline. The adaptation of D. viridis to toxic concentrations of copper ions resulted in the increase of the rate of chronological aging compared to the CuS-subline. Four subcultures with different rates of transplanting were obtained from each subline. The rate of replicative aging was shown to be dependent on the rate of chronological aging of subcultures (passage rate). The pre-adaptation of D. viridis to toxic concentrations of copper ions was accompanied by increase of accumulation rate of TAG and DNA in cells, which was interpreted as a sign of cellular aging during the progressive passages of the algae culture.展开更多
Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses （Central Zone of the Limpopo Complex） suggest that the formation of the...Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses （Central Zone of the Limpopo Complex） suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750--800 ℃ and 5.5--6.2 kbar, partial melting, and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650--700 ℃. These processes caused local variations of water and alkali activity in the fluids, resulting in various mineral assemblages within the dehydration zone. The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO2-（K, Na）Cl fluids at 750 and 800 ℃ and 5.5 kbar. It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-（K, Na）CI fluids is accompanied by partial melting at 750--800 ℃. Orthopyroxene-bearing assemblages are characteristic for temperature 800 ℃ and are stable in equilibrium with fluids with low salt concentrations, while salt-rich fluids produce clinopyroxene-bearing assemblages. These observations are in good agreement with the petrological data on the dehydration zones within the Sand River olthogneisses.展开更多
In the context of the continuous increase in global grain production,accompanied by a large amount of investment in various pesticides,herbicides,fungicides,and other chemical pesticides.It has caused inevitable envir...In the context of the continuous increase in global grain production,accompanied by a large amount of investment in various pesticides,herbicides,fungicides,and other chemical pesticides.It has caused inevitable environmental problems and food safety problems.Current research suggests that the use of cyclodextrins and their derivatives to protect pesticides can significantly reduce the number of agrochemicals that pollute the environment.Using the cavity properties of cyclodextrins,we can refer to the similar way in which drug molecules make cyclodextrins and cyclodextrin polymers to form inclusion compounds.Overall,β-cyclodextrin and its derivatives are used as a new pesticide excipient to improve the stability of pesticides,prevent their oxidation and decomposition,improve the solubility and bioavailability of pesticides,reduce the toxic side effects of drugs,and mask the odour of drugs.In this review,we focus on summarising the recent research progress ofβ-cyclodextrins and their derivatives in pesticides and other fields,and provide a systematic classification ofβ-cyclodextrin polymers,as well as new synthesis methods and techniques in various applications.Finally,the future development of cyclodextrin-like polymers is foreseen,and issues arising from the research are discussed and addressed in depth.展开更多
The stratigraphic division and sequence of the Upper Cretaceous sediments in eastern Heilongjiang Province,China,have been ambiguous and controversial,mainly due to a lack of biostratigraphically useful fossils and re...The stratigraphic division and sequence of the Upper Cretaceous sediments in eastern Heilongjiang Province,China,have been ambiguous and controversial,mainly due to a lack of biostratigraphically useful fossils and related radiometric dating.A new species of angiospermous fossil plant.Platanus heilongjiangensis sp.nov.,from Qitaihe in eastern Heilongjiang has been found in sediments conformably above which zircons from a rhyolitic tuff has been dated by U-Pb radiometric methods as 96.2±1.7 Ma.indicating that the Upper Houshigou Formation is of Cenomanian age.This discovery not only provides new data to improve our stratigraphic understanding of the Houshigou Formation,but also shows that Platanus flourished in the early Late Cretaceous floras of the region.This new study also indicates active volcanism taking place in the eastern Heilongjiang region during the Cenomanian of the Late Cretaceous.展开更多
Photodynamic therapy based on photogeneration of cytotoxic singlet oxygen and following oxidative stress is currently used in neuro-oncology for destruction of brain tumors.However,along with a tumor,it damages health...Photodynamic therapy based on photogeneration of cytotoxic singlet oxygen and following oxidative stress is currently used in neuro-oncology for destruction of brain tumors.However,along with a tumor,it damages healthy neurons and glial cells.We studied the involvement of the glutamate-related signaling pathway in photodynamic damage to normal glial cells in the crayfish stretch receptor.This model object consists of a single neuron surrounded by glial cells.It was photosensitized with alumophthalocyanine Photosens and irradiated by the diode laser(670 nm).Application of enzyme inhibitors and ion channels modulators showed that exogenous L-glutamate decreased photoinduced apoptosis of crayfish glial cells.The natural neuroglial mediator N-acetylaspartylglutamate,which releases glutamate after splitting by glutamate carboxypeptidase II,also inhibited photoinduced apoptosis.Inhibition of glutamate carboxypeptidase II,oppositely,enhanced glial apoptosis.This confirmed the antiapoptotic activity of glutamate.Glutamate agonist NMDA or inhibitor of NMDA receptors MK801 did not influence photodynamic death of glial cells,i.e.,these receptors did not participate in glial apoptosis.Inhibition of metabotropic glutamate receptors mGluRI with AP-3 reduced PDT-induced apoptosis of glial cells.Thus,chemical modifiers of various signaling processes can modulate photoinduced necrosis or apoptosis of glial cells and thus modify efficiency of photodynamic therapy.展开更多
文摘Pure fraction (92%-95%) of phagocytes (FP) and a mixture of amoebocytes(62%) and morula cells (38 %) FPMC of the holothurian Eupentacta fraudatrix (Holothuroidea, Dendrochirota) were obtained by using ficoll verographine step gradient. Basal production of reactive oxygen species (ROS) in FP quantified by using reduction of nitroblue tetrazolium (NBT) was more than twice that in FPMC. Thermostable toxin of Yersinia pseudotuberculosis (TST) at different concentrations ( 0.2; 0.5; 2.5 μg/ml, but not 0.1 μg/ml) stimulated NBT reduction in FPMC after 24 h incubation. In FP, TST at concentrations of 0.1 and 0.2 μg/ml inhibited and at concentrations of 0.5 and 2.5 μg/ml stimulated NBT reduction after 24 h incubation. Maximal effect was observed in FP and FPMC at TST concentrations of 0.5 and 0.2 μg/ml, respectively. Addition of catalase (0.7 μg/ml) to the cells treated with TST (2.5 μg/ml) was followed by a decrease in NBT reduction compared to that under toxin treatment alone. TST stimulated superoxide dismutase activity in concentration dependent manner (maximum at 0.5 μg/ml concentration in FP) after 24 h treatment, and this stimulation was prevented by a commercial catalase. Plant lectin concanavalin A stimulated NBT reduction more than 5 fold in FPMC compared to the control. With addition of TST, lectin stimulated ROS to lesser extent than that with lectin alone. When catalase, TST, and lectin were added into the FPMC simultaneously, ROS increase was similar to that under lectin treatment alone. On the whole, data obtained indicated that ROS generation in holothurian coelomocytes especially occurs in both stimulated and not stimulated phagocytes, and that changes in ROS production by these cells may be one of the mechanisms of antibacterial protection of holothurians.
文摘Free and initiated by 0.9% sodium chloride solution yielding of crystals was studied in the urine of the 35 healthy people. The metabolites—sodium lactate and sodium pyruvate—were superinduced into the dryable biological system in the increasing physiological concentrations. Regularities of the neogenic mixtures’ crystallization were revealed according to the metabolites dose. We showed the antagonistic tendencies in the parameters’ change at the increasing concentrations of the different metabolites—substratum of the enzyme’s opposite reactions—relying on the comparative estimation of the crystalloscopical and tezigraphical indices’ dynamics. Our own data and literature information brought us to a new conception of the biofluid’s stability as a crystallogenetic solution. According to it any substance injected into a dehydrated biological system proves to be a stabilizing or destabilizing agent which leads to a significant reorganization of the biocrystallogenesis. This phenomenon may cause a development of a management strategy of the biological crystallogenesis processes.
基金the state on behalf of the Ministry of Education and Science of the Russian Federation of the Agreement (No. 14.577.21.0111 (22 September 2014))The unique identifier of the applied research (No. RFMEFI57714X0111)
文摘In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for Mg（OH）2 precipitation was demonstrated. In this study, crystalline Mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （Mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that Mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg（OH）2 are 30-265 nm length or width.
基金supported by the Federal Target Program"Research and professional community of innovative Russia,2009-2013"(project#P-869,agreements#14.B37.21.1080 and14.B37.21.1076)
文摘TiO2 compounds possess relatively high adsorption abilities and exhibit high photocatalytic activities that exhibit potential for the destruction of organic pollutants in natural and waste waters.Nanostructured potassium polytitanates modified using transition metals and their oxides/hydroxides generate new nanomaterials that operate in the visible spectral range.This study presents the synthesis and investigation of the structure,composition and photocatalytic activity of powdered nanoscale quasi-amorphous potassium polytitanates particles modified with iron,zinc,copper,cobalt and nickel sulfate in aqueous solutions.All of the powders investigated in this work exhibit a high adsorption capacity for methylene blue dye（15-20mg/g） related to the welldeveloped surface of the layered potassium polytitanate particles.Introducing transition metals and their oxides/hydroxides influences the electronic structure of the obtained systems.A high photocatalytic activity was observed for systems containing iron,zinc,nickel and their oxides/hydroxides in the ultraviolet and visible ranges.
基金supported by the SAFE-AGT pilot(no.EP/T009314/1)with funding from the Engineering and Physical Sciences Research Council(EPSRC).
文摘Ammonia has been considered as a novel fuel for decarbonization purposes.However,emissions from combustion systems are still posing a problem.Therefore,experimental and numerical simulations have been conducted to study the concentration of exhaust emissions(Nitric oxide“NO”,Nitrous oxide“N_(2)O”)from burning the ammonia/hydrogen(NH_(3)/H_(2))blend 85/15(vol%).The effects were measured at various thermal powers ranging 10 to 20 kW and with different Reynolds numbers from 20,000—40,000.The experimental points were numerically investigated in the Ansys CHEMKIN-Pro environment employing seven chemical kinetic mechanisms taken from the literature.All experiments have been undertaken at standard atmospheric conditions.The experimental results showed that both NO and N_(2)O gradually increased when the Reynolds number increased from 20,000 to 40,000.Along with that,the concentration of NO emissions at the exhaust reported minimum level when the Re=20,000 due to lower reactivity radical formation,all that led to a deterioration of the flame characteristics.Also,the integrated radical intensities of NO*,OH*,NH*,and NH_(2)*demonstrate an increasing trend as Re increased from 20,000 to 40,000.In terms of thermal power,N_(2)O suffered an abrupt decrease when the thermal power increased up to 15 kW,while the opposite occurs for NO.In addition,the radicals intensity of OH*,NH*and NH_(2)*figures show an increase in their concentration when the thermal power increased up to 15 kW then decreased with increasing thermal intensity to reach 20 kW,reflecting into increased NO productions and decreased N_(2)O levels.The numerical analysis showed that Stagni,Bertolino,and Bowen Mei were the most accurate mechanisms as these give a good prediction for NO and N_(2)O.The study also showed that the chemical reaction(HNO+O_(2)←→NO+HO_(2))is the main source of NO formation.While the chemical reaction(NH+NO←→N_(2)O+H)is responsible for the formation of N_(2)O by consuming NO and when there will be abundance in NH radicals.F
基金NSFC/RFBR grant 20-52-53009Guoshoujing Telescope(the Large Sky Area Multi-Object Fiber Spectroscopic Telescope,LAMOST)is a National Major Scientific Project built by the Chinese Academy of Sciencesprovided by the National Development and Reform Commission。
文摘We have determined new statistical relations to estimate the fundamental atmospheric parameters of effective temperature and surface gravity,using MK spectral classification,and vice versa.The relations were constructed based on the published calibration tables(for main sequence stars)and observational data from stellar spectral atlases(for giants and supergiants).These new relations were applied to field giants with known atmospheric parameters,and the results of the comparison of our estimations with available spectral classification have been quite satisfactory.
文摘BACKGROUND Fractures of the proximal femur epiphysis are problematic for state health care because they are associated with severe medical and social problems and high morbidity and mortality rates.AIM To model the potential risk of hip fracture via femur geometric parameters.METHODS Seventy educational cadaveric femurs from people aged 14 to 80 years,10 X-ray images from the records of the Human Anatomy Department and 10 X-ray images from the Department of Traumatology,Orthopedics and Disaster Surgery of Sechenov University,were evaluated.The parameters of the fractured bone were measured using images captured with a Canon d60 camera.The projection values of the proximal epiphysis of the cadaveric femurs and geometric parameters of the bones shown in the X-ray images were measured with Autodesk software(AutoCAD 2018).Analysis of the video frames showing bone rotation reveal that the greater trochanter can be inscribed in a parallelepiped,where one of the faces is parallel to the plane of view in the frontal standard projection and is rectangular.The angle of bone rotation obtained by turning the cube corresponded to the angle measured with the second technique.This reliable method of calculating the rotation of the bone relative to the anterior projection was employed in subsequent calculations.The geometric parameters of the femur were measured using X-ray images according to the proposed method.RESULTS The geometric parameters of 70 femurs were analyzed,and correlation coefficients were calculated.Our measurement results were compared with those reported by other authors.The potential influence of femur geometry on force distribution in the proximal epiphysis of the femur was described,and a 2-dimensional model of the femur epiphysis associated with minimal neck fracture risk was provided.The assessment of the geometric parameters of the femoral epiphysis indicated the greatest risk of a varus fracture of the neck if the angle of the minimal resistance zone(AMRZ)index>24°and the neck-shaft angle(NSA)<127.5°.
文摘It is known that cytoskeleton-dependent trafficking of cell wall and membrane components to apical plasma membrane （PM） coupled with ion transport across pollen PM is crucial for maintaining polar pollen tube growth. To elucidate whether plant hormones are involved in these processes, the effects of exogenous phytohormones, indole-3-acetic acid （IAA）, abscisic acid （ABA）, gibberellin A3 （GA3） and cytokinin （kinetin） on the growth, PM polarization, actin cytoskeleton （AC） organization and cytoplasmic pH （pile） of in vitro 4 h-growing petunia pollen tubes were investigated. IAA, ABA and GA3 displayed the growth-stimulating effects and these were accompanied by orthovanadate-sensitive hyperpolarization of the PM. Fluorescent labeling the enzyme with H＋-ATPase antibodies exhibited IAA- and ABA-induced lateral PM redistribution of it into the subapical zone of pollen tube PM. Pollen cultivation on the medium with latrunculin B, the inhibitor of actin polymerization, resulted in inhibition of pollen tube growth and simultaneously in the drop of endogenous IAA content. The IAA-growth stimulating effect was correlated with increased content of actin filaments （AF） in both apical and subapical zones of tubes, while ABA and GA3 exerted the same effect but it was accompanied by redistributing F-actin only to apical zone. In contrast, kinetin decreased the total F-actin content and inhibited pollen tube growth. It has been shown that the pHe of growing pollen tubes is sensitive to the plant hormones. In the case of male gametophyte growing for 1, 2 and 4 h, IAA induced alkalinization of the cytosol, while ABA and GA3 exerted qualitatively similar effect only after its growth for 1 h and 4 h, respectively. Kinetin, in contrast, resulted in acidification of the cytosol. All these results, taken together, indicate, for the first time, potential targets of the phytohormone action in pollen tubes.
文摘For safe development of underground space and especially in areas of geological infringements it is necessary to creat effective system of tracking, forecasting and management for deforming processes in such areas-system of geomechanical monitoring. Besides it is necessary to study and imagine the internal mechanism of deforming processes in such special zones. In the paper some basic aspects of creation of geomechanical monitoring systems for realization of supervision, study and modelling of deforming processes, for modelling and study of the stress-strain state of massif in areas of large-scale underground mining works in view of a block-hierarchical structure of rock’s massive (presence of geological infringements) are considered. In particular such important tasks, as research of deforming processes in areas of geological infringements with the help of GPS-technologies and use of the received results for the modeling; construction of models adequately describing a condition of rock’s massive in area of geological infringement. Some results of researches on study of cavities influence on occurrence of an area of limiting conditions in region of geological infringement and possible shift along infringement are submitted.
基金supportedby the Russian Foundation of Basic Researches,projects 16–07–1162 and 18–02–00890Funding for the DPAC has been provided by nationalinstitutions, in particular the institutions participating inthe Gaia Multilateral Agreement
文摘The Binary star DataBase(BDB, http://bdb.inasan.ru) combines data from catalogs of binary and multiple stars of all observational types. There is a number of ways for variable stars to form or to be a part of binary or multiple systems. We describe how such stars are represented in the database.
基金supported by grants from the Ministry of Education and Science of Ukraine(0116U003593)grant from cieA3(Campus de Excelencia Internacional Agroalimentario)-UCO,Spain
文摘Plant nonspecific lipid transfer proteins (nsLTPs) are widely distributed through plant kingdom and are characterized by the presence of a central hydrophobic cavity, suitable for binding various hydrophobic molecules. Despite extensive research on nsLTP in different plant species, mostly angiosperm, and the great diversity of physiological processes in which they seem to be involved, their exact functions still remain unclear. Also, very limited experimental data are available on nsLTP in gymnosperm. In this study, we report for the first time on the molecular cloning of nsLTP, from Pinus sylvestris L.(PsLTP1, GenBank accession JN980402.1) and the expression pattern of PsLTP1 during ontogenesis and in response to environmental stress conditions. Total RNA from roots of 7-day old pine seedlings was used to isolate the cDNA clone, corresponding to Scots pine lipid transfer protein. The open reading frame of PsLTP1 consists of 372 bp encoding a protein of 123 amino acids. Amino acid sequence alignment revealed that mature PsLTP1 shares high level of similarity with nsLTP from other conifers and with well-studied nsLTPs from angiosperms. The PsLTP1 contains a 27-amino-acid N-terminal signal sequence and presents all the features of a plant nsLTP. Amino acid comparison analysis and 3D structure prediction showed that PsLTP1 is a type 1 nsLTP. The results of the expression analysis of Scots pine PsLTP1 gene revealed that its transcripts accumulate in actively growing tissues. Furthermore, transcription of PsLTP1 was upregulated in response to cold and salt treatments, and downregulated during acidic, osmotic and water stresses.
文摘In this paper,we study such polyadic analog of an identity of a group asm-neutral sequence.In particular,we prove that all Post's equivalence classes of thefree covering group of any n-ary group[where n=k(m-1)+1 and k≥1]definedby m-neutral sequences form the(k+1)-ary group,which is isomorphic to the n-arysubgroup of all identities of the n-ary group in the case when m=2.
文摘Two sublines of microalgae Dunaliella viridis Teodor. were obtained: CuS—a subline sensitive to toxic concentration of copper ions and CuR—a subline resistant to toxic concentration of copper ions. The chronological aging of cultures was revealed in increase of DNA (polyploidization) and triacylglycerols (TAG) content in microalgae cells. The adaptation of D. viridis to toxic concentrations of copper ions resulted in formation of an adaptive epygenotype characterized by increased content of carbonylated proteins and decreased content of proline compared to the CuS-subline. The adaptation of D. viridis to toxic concentrations of copper ions resulted in the increase of the rate of chronological aging compared to the CuS-subline. Four subcultures with different rates of transplanting were obtained from each subline. The rate of replicative aging was shown to be dependent on the rate of chronological aging of subcultures (passage rate). The pre-adaptation of D. viridis to toxic concentrations of copper ions was accompanied by increase of accumulation rate of TAG and DNA in cells, which was interpreted as a sign of cellular aging during the progressive passages of the algae culture.
基金supported by Russian Foundation for Basic Research(project 10-05-00040 to OGS)Russian President Grants for Young Scientists(MD-222.2012.5 to OGS)+1 种基金grant from the National Science Foundation of South Africa(GUN:20531 92 to DDvR)University of Johannesburg as a part of the Russian South African scientific collaboration
文摘Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses （Central Zone of the Limpopo Complex） suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750--800 ℃ and 5.5--6.2 kbar, partial melting, and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650--700 ℃. These processes caused local variations of water and alkali activity in the fluids, resulting in various mineral assemblages within the dehydration zone. The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO2-（K, Na）Cl fluids at 750 and 800 ℃ and 5.5 kbar. It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-（K, Na）CI fluids is accompanied by partial melting at 750--800 ℃. Orthopyroxene-bearing assemblages are characteristic for temperature 800 ℃ and are stable in equilibrium with fluids with low salt concentrations, while salt-rich fluids produce clinopyroxene-bearing assemblages. These observations are in good agreement with the petrological data on the dehydration zones within the Sand River olthogneisses.
基金supported by the National Key Research and Development Program(2021YFA0716702)the National Natural Science Foundation of China(22071074,21772055)the 111 Project(B17019)。
文摘In the context of the continuous increase in global grain production,accompanied by a large amount of investment in various pesticides,herbicides,fungicides,and other chemical pesticides.It has caused inevitable environmental problems and food safety problems.Current research suggests that the use of cyclodextrins and their derivatives to protect pesticides can significantly reduce the number of agrochemicals that pollute the environment.Using the cavity properties of cyclodextrins,we can refer to the similar way in which drug molecules make cyclodextrins and cyclodextrin polymers to form inclusion compounds.Overall,β-cyclodextrin and its derivatives are used as a new pesticide excipient to improve the stability of pesticides,prevent their oxidation and decomposition,improve the solubility and bioavailability of pesticides,reduce the toxic side effects of drugs,and mask the odour of drugs.In this review,we focus on summarising the recent research progress ofβ-cyclodextrins and their derivatives in pesticides and other fields,and provide a systematic classification ofβ-cyclodextrin polymers,as well as new synthesis methods and techniques in various applications.Finally,the future development of cyclodextrin-like polymers is foreseen,and issues arising from the research are discussed and addressed in depth.
基金the Project of the MOST,China(No.2015FY310100)Project of China Geology Survey(No.DD20160120-04) for their financial supportsthe Key Lab of Evolution of Past Life in NE Asia, MLRC (in Shenyang), for research support
文摘The stratigraphic division and sequence of the Upper Cretaceous sediments in eastern Heilongjiang Province,China,have been ambiguous and controversial,mainly due to a lack of biostratigraphically useful fossils and related radiometric dating.A new species of angiospermous fossil plant.Platanus heilongjiangensis sp.nov.,from Qitaihe in eastern Heilongjiang has been found in sediments conformably above which zircons from a rhyolitic tuff has been dated by U-Pb radiometric methods as 96.2±1.7 Ma.indicating that the Upper Houshigou Formation is of Cenomanian age.This discovery not only provides new data to improve our stratigraphic understanding of the Houshigou Formation,but also shows that Platanus flourished in the early Late Cretaceous floras of the region.This new study also indicates active volcanism taking place in the eastern Heilongjiang region during the Cenomanian of the Late Cretaceous.
基金The work was supported by the grants of the Russian Foundation for Basic Research No.05-04048440 and 08-04-01322 and the grant No.2.1.1/6185 of the Ministry of Education and Science of Russian Federation.
文摘Photodynamic therapy based on photogeneration of cytotoxic singlet oxygen and following oxidative stress is currently used in neuro-oncology for destruction of brain tumors.However,along with a tumor,it damages healthy neurons and glial cells.We studied the involvement of the glutamate-related signaling pathway in photodynamic damage to normal glial cells in the crayfish stretch receptor.This model object consists of a single neuron surrounded by glial cells.It was photosensitized with alumophthalocyanine Photosens and irradiated by the diode laser(670 nm).Application of enzyme inhibitors and ion channels modulators showed that exogenous L-glutamate decreased photoinduced apoptosis of crayfish glial cells.The natural neuroglial mediator N-acetylaspartylglutamate,which releases glutamate after splitting by glutamate carboxypeptidase II,also inhibited photoinduced apoptosis.Inhibition of glutamate carboxypeptidase II,oppositely,enhanced glial apoptosis.This confirmed the antiapoptotic activity of glutamate.Glutamate agonist NMDA or inhibitor of NMDA receptors MK801 did not influence photodynamic death of glial cells,i.e.,these receptors did not participate in glial apoptosis.Inhibition of metabotropic glutamate receptors mGluRI with AP-3 reduced PDT-induced apoptosis of glial cells.Thus,chemical modifiers of various signaling processes can modulate photoinduced necrosis or apoptosis of glial cells and thus modify efficiency of photodynamic therapy.
