The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborat...The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborate monomer design.The high-energy local triplet state(^(3)LE)of carbazole complicates its application despite the molecular orbital arrangement being suitable for blue emission.Here,we present an approach to polymer design that makes it possible to solve this problem.We demonstrate the in situ formation of a TADF donor-acceptor system during Suzuki polycondensation,creating an extended carbazole-based donor matrix coupled with a triazine acceptor.The resulting polymer exhibited efficient TADF with a low energy gap(ΔE_(ST))value if a phenyl N-substituent,enabling essential electron delocalization,was present in the carbazole moiety.This work establishes a versatile platform for developing carbazole-based TADF polymers,overcoming the fundamental limitations that hinder their widespread application.展开更多
The phase-conjugation characteristics of stimulated thermal scattering (STS) in absorbing liquid and stimulated Brillouin scattering (SBS) separately excited in pure acetone were compared, and the effect of focal pump...The phase-conjugation characteristics of stimulated thermal scattering (STS) in absorbing liquid and stimulated Brillouin scattering (SBS) separately excited in pure acetone were compared, and the effect of focal pumping conditions on them was studied. It is shown that high-quality phase conjugation can be obtained by STS in absorbing liquid under stronger pumping conditions.展开更多
Several conjugate components represent the aquatic ecosystem of Lake Baikal:Baikal water(surface and deep water),groundwater from boreholes,water of numerous Baikal tributaries,cold and hot mineral springs around Lake...Several conjugate components represent the aquatic ecosystem of Lake Baikal:Baikal water(surface and deep water),groundwater from boreholes,water of numerous Baikal tributaries,cold and hot mineral springs around Lake Baikal,and the Angara River,the only runoff reflecting all this aquatic diversity.River waters in the Baikal region are known to be deficient in some vital elements,including fluorine.This article discusses the features of the fluorine distribution in the water from the conjugate components of the Baikal ecosystem.Fluorine ion concentrations in the water of the Baikal ecosystem was determined using the potentiometric method.The study represents the monitoring that was carried out between 1997 and 2022 years.We determine likely causes of high and low fluorine concentrations in the water from different components,propose and substantiate the fluorine sources,geological and geochemical model of its influx and distribution features in the water of the Baikal ecosystem.展开更多
Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the inte...Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the interface,further growth of hydrate due to the suction of water in the capillary system formed between the wall of the cuvette and the end boundary of the hydrate layer occurs.Most probably,substantial effects on the formation of this capillary system may be caused by variations in reactor wall properties,for example,hydrophobic-hydrophilic balance,roughness,etc.We found,that the rate of CO_(2) hydrate film growth on the surface of the humic acid aqueous solution is 4-fold to lower in comparison with the growth rate on the surface of pure water.We suppose that this is caused by the adsorption of humic acid associates on the surface of hydrate particles and,as a consequence,by the deceleration of the diffusion of dissolved carbon dioxide to the growing hydrate particle.展开更多
The southern part of East Siberia(SES)is highly vulnerable to flooding caused by the extreme precipitation events(EPEs)during summer.Building on previously detected EPEs in SES and Mongolia,we examined wave propagatio...The southern part of East Siberia(SES)is highly vulnerable to flooding caused by the extreme precipitation events(EPEs)during summer.Building on previously detected EPEs in SES and Mongolia,we examined wave propagation patterns for two periods:1982-98 and 1999-2019.Our analysis revealed distinct wave train configurations and geopotential anomalies preceding EPEs,with an increase in wave activity flux across the Northern Hemisphere,followed by a subsequent decrease during EPEs.Consequently,Eastern Siberia has experienced a significant rise in wave activity.Based on geopotential anomalies over Central Siberia accompanying EPEs,we identified two main types.The first,the ridge type,is predominant during the first period and features a meridional contrast with a positive geopotential(and temperature)anomaly over Central Siberia and a negative anomaly over the subtropical regions along the same longitude.The second type,termed the trough type,is more typical for the second period.It involves either a negative geopotential anomaly or the zonal proximity of positive and negative geopotential anomalies over Central Siberia.The trough type,marked by zonally oriented anomalies in geopotential and temperature,results in a more pronounced temperature decrease before EPEs and significant zonal temperature contrasts.Further,it is related to more stationary waves over Northern Eurasia,with persistent positive geopotential anomalies over Europe linked to quasi-stationary troughs over Central Siberia and positive anomalies east of Lake Baikal.Our findings align with shifts in boreal summer teleconnection patterns,reflecting significant changes in wave propagation patterns that have occurred since the late 1990s.展开更多
Type 2 diabetes mellitus(T2DM)significantly elevates the risk of colorectal cancer(CRC)and complicates its treatment by promoting chemoresistance.Poor glycemic control has been linked to exacerbated CRC progression an...Type 2 diabetes mellitus(T2DM)significantly elevates the risk of colorectal cancer(CRC)and complicates its treatment by promoting chemoresistance.Poor glycemic control has been linked to exacerbated CRC progression and diminished chemotherapy efficacy,impacting patient outcomes through various mechanisms such as oxidative stress,activation of metabolic pathways,and altered protein modifications that hinder apoptosis and enhance tumor survival.Clinical evidence shows that T2DM patients experience higher rates of chemoresistance and reduced disease-free survival and overall survival compared to non-diabetic patients.Specifically,those with poor glycemic control exhibit increased chemo-resistance and poorer survival metrics.Antidiabetic treatments,including metformin,acarbose,and gliclazide,show promise in improving chemotherapy response and glycemic management,potentially enhancing patient outcomes.Addressing this challenge requires a comprehensive,multidisciplinary approach involving oncologists,endocrino-logists,and surgeons to optimize patient care.Integrated strategies that prioritize glycemic control are essential for reducing chemoresistance and improving survival in CRC patients with T2DM.展开更多
The growing demand for luminescent nanomaterials intended for various applications increases the necessity to develop and improve approaches to the creation of highly efficient nanosized phosphors.In current study,an ...The growing demand for luminescent nanomaterials intended for various applications increases the necessity to develop and improve approaches to the creation of highly efficient nanosized phosphors.In current study,an approach to enhancing the efficiency of red luminescence of monoclinic Y_(2)O_(3):Eu^(3+)with the particle size of~20 nm by creating the oxygen-enriched environment during the gas-phase synthesis was developed.To investigate the effect of oxygen amount during the synthesis on characteristics of the phosphor,a series of nano structured Y_(2)O_(3):Eu^(3+)with the addition of 0-40 vol%O_(2) to the main buffer gas Ar was synthesized by laser vaporization.It is shown that the amount of added O_(2) exerts virtually no effect on the phase composition and particle size,but significantly improves the luminescent characteristics of Y_(2)O_(3):Eu^(3+).Thus,the addition of 30 vol%O_(2) leads to virtually a 20-fold growth in the photoluminescence(PL)intensity caused by ^(5)D_(0)→^(7)F_(0-4) transitions in Eu^(3+)and an increase in the absolute PL quantum yield from 3%to 53%(λex=395 nm)compared to the sample synthesized without O_(2).The addition of oxygen also improves the emission color coordinates from(0.571,0.320)to(0.630,0.322)due to the removal of a considerable fraction of oxygen vacancies.The synthesized nanopowders are shown to be highly stable:upon storage under ambient conditions for two years.Quantum yield(QY)of the samples decreases by less than 2%.It is expected that the key features underlying the proposed approach will be useful for various methods used to synthesize oxide nanophosphors.展开更多
Objectives:Currently,there exist two approaches to the treatment of malignant neoplasms:the Karanahan technology and in situ vaccination,which are based on chronometric delivery of therapeutic agents to the tumor depe...Objectives:Currently,there exist two approaches to the treatment of malignant neoplasms:the Karanahan technology and in situ vaccination,which are based on chronometric delivery of therapeutic agents to the tumor depending on the characteristics of tumor cells,as well as the immune status.The main purpose of this study was to experimentally prove the feasibility of combining the Karanahan technology and in situ vaccination withαOX40 antibodies into a single therapeutic platform to achieve a potent additive antitumor therapeutic effect.Methods:BALB/c mice grafted with B-cellular lymphoma A20 were treated using the Karanahan technology consisting of intraperitoneal cyclophosphamide administrations and intratumoral DNA injections according to an individually determined therapeutic regimen,together with in situ vaccination withαOX40.A pathomorphological analysis of the organs of experimental animals that died during the initial attempt to combine the two technologies was carried out.An analysis of blood cell populations was performed to determine the safe time for antibody administration:the number of immune cells capable of activating systemic inflammation(CD11b+Ly-6C+,CD11b+Ly-6G+,CD3–NKp46+CD11b+),the presence of Fc receptor and OX40 on the surface of these cells,and the number of neutrophils activated to NETosis were analyzed.Based on the analysis results,the antitumor efficacy of various modes of combining the Karanahan technology and in situ vaccination was studied.Results:WhenαOX40 was administered 5 h after each treatment using the Karanahan technology,mass death of mice caused by systemic inflammation and multiple organ failure was observed.The state of blood cells after the treatment using the Karanahan technology at the time points corresponding to antibody injections was analyzed to elucidate the reasons for this effect.It was found that at some time points,there occurs activation of the immune system and a powerful release(up to 16%)of monocytes and granulocytes carrying Fc receptor and OX40 on their surface into blood;when interacting withαOX40,they can activate the lytic potential of these cells.Activation of neutrophils to NETosis was also observed.Based on these findings,a study was carried out in different time regimes to combine the Karanahan technology andαOX40 injections.WhenαOX40 was injected into the points of minimal release of myeloid cells into the blood,increased survival rate and the greatest antitumor efficacy were observed:37%of animals survived without relapses on day 100 after experiment initiation.Conclusions:The results obtained indicate that it is possible to combine the Karanahan technology and in situ vaccination withαOX40,with obligatory constant monitoring of the number of myeloid cells in peripheral blood to determine the safe time for antibody injection.展开更多
The article presents the results of a study on the possibility of synthesizing biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate)[P(3HB-co-4HB)]from renewable waste fish oil(WFO)by the Cupriavidus necator B-10...The article presents the results of a study on the possibility of synthesizing biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate)[P(3HB-co-4HB)]from renewable waste fish oil(WFO)by the Cupriavidus necator B-10646 bacterium.For the first time,waste oil generated during the processing of Sprattus balticus in the pro-duction of sprats was used as the main carbon substrate for the synthesis of P(3HB-co-4HB),andε-caprolactone was used as a precursor instead of the more expensiveγ-butyrolactone.Samples of P(3HB-co-4HB)with a 4HB monomer content from 7.4 to 11.6 mol.%were synthesized,and values of the bacterial biomass yield and the total yield of the copolymer were comparable with the control(where butyric acid was used as carbon source).The following properties of the samples were studied:molecular weight,temperature characteristics,thermal behavior,isothermal crystallization of melts,and the formation of spherulites.The renewable fatty substrate of complex composition was used to synthesize samples of technologically advanced low-crystallinity P(3HB-co-4HB)with significant proportions of 4HB,without impairing the physicochemical properties of the polymer.The biotech-nological process involving the use of renewable WFO andε-caprolactone can be employed to reduce the costs of producing a promising“green”bioplastic and make it more affordable.展开更多
Understanding why elements are distributed in tree xylem in a particular way is a significant challenge in dendrochemistry.This study explored a hypothesis that metal elements in the xylem interact due to differences ...Understanding why elements are distributed in tree xylem in a particular way is a significant challenge in dendrochemistry.This study explored a hypothesis that metal elements in the xylem interact due to differences in physical properties such as ionic radius and ionization potential.Scots pine in an even-aged stand established during the early 1970s in eastern Siberia was the study species.Increment cores were taken from the north and south sides of trees and scanned with an X-ray fluorescent multi scanner.With the help of X-ray scanning,the following elements were analyzed:aluminum(Al),potassium(K),calcium(Ca),titanium(Ti),manganese(Mn),iron(Fe),copper(Cu),strontium(Sr)and zinc(Zn).Scanning data on the elements were split into early-wood and late-wood data for each year of growth.The following ratios were analyzed:Ca/Sr,Fe/Ca,Fe/Sr,Al/Cu,Al/Zn,Ti/Mn,and Mn/K.Among these,ones having a consistent pattern across tree rings,the ratios show a more or less dependable relationship:that an element shows a larger decrease(relative another element)that has a larger ionic radius and lower ionization potential.Hypothetically,this may be due to the advantage of an ion with smaller ionic radius and higher ionization potential under a deficit of accommodation centers in organic molecules.An experiment approach should be applied to clarify the relationships.展开更多
Melanomas are aggressive cancers,with a high rate of metastatic disease.Cutaneous(CM)and uveal(UM)melanomas are intrinsically different diseases,and most cell death inducers effective for CM do not function for UM.Thi...Melanomas are aggressive cancers,with a high rate of metastatic disease.Cutaneous(CM)and uveal(UM)melanomas are intrinsically different diseases,and most cell death inducers effective for CM do not function for UM.This is primarily due to the fact the eye is an immunologically privileged organ,and it fails to achieve the efficacy of immune checkpoint inhibitors(ICIs)comparable to that for CM.However,approaches utilizing specific melanomaassociated antigens are being developed for metastatic forms of CM and UM.The most promising to date are gp100 and tyrosinase related protein 1(TYRP1),primarily for the design of targeting chimeric molecules and for autologous T-/NK-cell products with a chimeric antigen receptor.The difference in the mutational profile of apoptosis-related genes in CM and UM also makes counterproductive the use of the same drugs re-activators of the intrinsic pathway of apoptosis.Therefore,the discovery of novel pathways of regulated cell death such as ferroptosis and cuproptosis may help in the development of new drugs for melanomas resistant to already available inducers of regulated cell death.Here we consistently discuss the latest advances in the therapy of melanomas,and above all-UM,which is classified as an orphan disease.展开更多
The insufficient electrocatalytic activity and CO_(2)resistance hinder the application of cathode mate-rial for solid oxide fuel cells(SOFCs).In this study,we introduce a series of Pr-doped perovskite Bi_(0.8-x)Pr_(x)...The insufficient electrocatalytic activity and CO_(2)resistance hinder the application of cathode mate-rial for solid oxide fuel cells(SOFCs).In this study,we introduce a series of Pr-doped perovskite Bi_(0.8-x)Pr_(x)Ca_(0.2)FeO_(3-δ)(BPCF_(x),x=0,0.10,0.15,0.20)as candidate cathode materials,with a focus on its phase structure,oxygen desorption ability,catalytic activity,and electrochemical reduction kinetics.Among all the components,the Bi_(0.6)Pr_(0.2)Ca_(0.2)FeO_(3-δ)(BPCF0.20)catalyst shows impressive oxygen reduc-tion reaction(ORR)activity,with a low polarization resistance of 0.06Ωcm^(2)at 700℃and peak power density of 810 mW cm^(−2)at 800℃.Moreover,the BPCF0.20 cathode shows outstanding CO_(2)resistance in different CO_(2)concentrations(1%-10%)due to the larger average bond energy and higher relative acidity of Bi,Pr,and Fe ions.These findings demonstrate that BPCF_(x)are advanced cathode electrocatalysts for SOFCs.展开更多
Nonlinear wavefront shaping is crucial for advancing optical technologies,enabling applications in optical computation,information processing,and imaging.However,a significant challenge is that once a metasurface is f...Nonlinear wavefront shaping is crucial for advancing optical technologies,enabling applications in optical computation,information processing,and imaging.However,a significant challenge is that once a metasurface is fabricated,the nonlinear wavefront it generates is fixed,offering little flexibility.This limitation often necessitates the fabrication of different metasurfaces for different wavefronts,which is both time-consuming and inefficient.To address this,we combine evolutionary algorithms with spatial light modulators(SLMs)to dynamically control wavefronts using a single metasurface,reducing the need for multiple fabrications and enabling the generation of arbitrary nonlinear wavefront patterns without requiring complicated optical alignment.We demonstrate this approach by introducing a genetic algorithm(GA)to manipulate visible wavefronts converted from near-infrared light via third-harmonic generation(THG)in a silicon metasurface.The Si metasurface supports multipolar Mie resonances that strongly enhance light-matter interactions,thereby significantly boosting THG emission at resonant positions.Additionally,the cubic relationship between THG emission and the infrared input reduces noise in the diffractive patterns produced by the SLM.This allows for precise experimental engineering of the nonlinear emission patterns with fewer alignment constraints.Our approach paves the way for self-optimized nonlinear wavefront shaping,advancing optical computation and information processing techniques.展开更多
Oxidative coupling of methane(OCM)is a catalytic partial oxidation process that directly converts methane into C_(2) products.For this high temperature reaction,understanding the radical behavior through experimental ...Oxidative coupling of methane(OCM)is a catalytic partial oxidation process that directly converts methane into C_(2) products.For this high temperature reaction,understanding the radical behavior through experimental investigation is important in correlating the catalytic activity and the products.In this work,a spatial resolution online mass spectrometry(MS)system was developed and applied to a Mn-Na_(2)WO_(4)/SiO_(2) catalyzed OCM system.In addition to the residue gas analysis,the system obtained the distribution information of the reactants and products in the reactor.At various setting temperatures,all species online MS signals were collected at different positions,mapping the reaction activity covering parameters including temperature,time and space.The distribution behavior of the catalytic activity,selectivity,and apparent activation energy were kinetically analyzed.Selectivity and additional carbon balance analysis strongly supported the radical coupling model of OCM and indicated that after the catalytic bed layer,there is a significant length in the reactor(>2 mm)filled with radicals.Based on the result,a designed new method by tuning the temperature field in the reactor was found effectively to improve the catalytic activity,especially the C_(2) yield from 702 to 773℃.展开更多
Jadeitites are formed either through direct precipitation from Na-Al-Si rich fluids(P-type),or by replacement of magmatic protoliths(R-type)in subduction zones.They are valuable targets for investigating the mobility ...Jadeitites are formed either through direct precipitation from Na-Al-Si rich fluids(P-type),or by replacement of magmatic protoliths(R-type)in subduction zones.They are valuable targets for investigating the mobility behavior and chemical composition of subduction zone fluids.The Rio San Juan Complex(RSJC)in the northern Dominican Republic hosts both P-and R-type jadeitites and jadeite-rich rocks,which provide ideal samples for addressing such issues.Here,we present trace element and Sr-Nd-O-Si isotope compositions of RSJC jadeitites and related rocks.Most samples show similar REE patterns,trace element distributions and δ^(18)O values to those of plagiogranite protoliths,indicating the predominance of R-type origin in RSJC.The P-type samples exhibit slightly higherδ^(30)Si values(−0.15‰to 0.25‰)than that of R-type samples(−0.20‰to 0.08‰),which place above the igneous array.The low(^(87)Sr/^(86)Sr)_(i)(0.70346 to 0.70505)and highεNd(t)values(4.6 to 6.8)of the P-type jadeitites and quartzites,along with relatively lowδ^(18)O values(4.7‰to 6.4‰)of their forming fluids,indicate that the fluids are likely derived from the altered basaltic crust rather than from oceanic sediment.However,the estimated jadeitite-and quartzite-forming fluids exhibit distinctδ^(30)Si values(0.76‰to 0.99‰and-0.48‰to-0.08‰,respectively),implying an evolution of the fluids that modified the Si isotopic compositions.Since fluid metasomatism and related desilication process could have lowered the whole-rock δ^(30)Si values,the heavy Si isotope compositions of the R-type samples are produced from the external fluids.Combing Rayleigh distillation and binary mixing simulations,we propose that fluids derived from altered oceanic crust obtained high δ^(30)Si values after crystallization of minerals enriched in light Si isotopes.The P-type jadeitites are formed through direct precipitation from this fluid.As the plagiogranite protoliths were continuously replaced by this fluid,the formed R-type samples(jadeitites and quartzites)also exhibit high δ^(30)Si values.Such rocks could significantly alter the Si isotope compositions of local mantle when they are deeply subducted at convergent plate margins.展开更多
Er^(3+)-and Tm^(3+)-doped Ca_(x)Sr_(2-x)Nb_(2)O_(7)(C_(x)S_(2-x)N,x=0.6,0.8,1,0,1.2,1,4) phosphors with layered pe rovskite structure were designed.These phosphors exhibit a dominant emission peak at 549 nm under980 n...Er^(3+)-and Tm^(3+)-doped Ca_(x)Sr_(2-x)Nb_(2)O_(7)(C_(x)S_(2-x)N,x=0.6,0.8,1,0,1.2,1,4) phosphors with layered pe rovskite structure were designed.These phosphors exhibit a dominant emission peak at 549 nm under980 nm laser excitation,attributed to the^(4)S_(3/2)→^(4)I_(15/2)transition.By increasing the content of Ca^(2+),the crystal field regulation of rare earth ions is realized and the luminescence enhancement is induced,which is manifested by the increase of^(2)H_(11/2),^(4)S_(3/2)→^(4)I_(15/2)emission.Furthermore,the temperature sensing sensitivities of C_(0.6)S_(1.4)N:Er,Tm and C_(0.6)S_(1.4)N:Er,Tm based on non-thermally coupled energy levels were studied.Finally,an anti-counterfeiting imprint was prepared using phosphors,which have high brightness and excellent photothermal stability.This work not only confirms that closer ionic radii substitution enables to increase the electronic density of states,improve the crystal field symmetry and enhance the luminescence,but also provides a promising phosphor system for temperature sensing and anti-counterfeiting applications,opening up new prospects in the optimization of the optical properties of phosphors.展开更多
The study by Dos Santos et al marks a significant advancement in understanding the genetics of colorectal polyposis,particularly within the underrepresented Brazilian population.Utilizing whole-exome sequencing in 27 ...The study by Dos Santos et al marks a significant advancement in understanding the genetics of colorectal polyposis,particularly within the underrepresented Brazilian population.Utilizing whole-exome sequencing in 27 patients with unexplained polyposis,the researchers identified 16 candidate genes in 44.4%of cases-an impressive outcome given strict exclusion criteria.Many identified variants were linked to the Wnt/β-catenin signaling pathway,reinforcing their biological relevance.However,the study underscores key challenges in genomic medicine,especially the gap between gene discovery and clinical application.A substantial proportion of variants(60.1%)were classified as of uncertain sig-nificance,and the absence of functional validation or segregation analysis limits clinical interpretation.Notably,the potential for oligogenic inheritance com-plicates traditional monogenic models of hereditary cancer risk.The study’s focus on a genetically diverse Brazilian cohort emphasizes the need for population-specific genomic resources and interpretation guidelines.Moving forward,func-tional studies,including organoid models,loss-of-heterozygosity analyses,and genotype-phenotype correlations,are essential to validate findings.Clinically,discovering novel candidate genes may inform future screening and testing pro-tocols,though careful consideration is needed to manage uncertain results.Overall,the study represents a critical step in polyposis genetics,highlighting both progress made and the work still required for clinical translation.展开更多
基金supported by the Russian Science Foundation (No. 25-13-00300)the Centre for Optical and Laser Materials Research (SPbSU) and Saint Petersburg State University for measuring the quantum yields of luminescence within the framework of research project(No.125021902439-8)。
文摘The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborate monomer design.The high-energy local triplet state(^(3)LE)of carbazole complicates its application despite the molecular orbital arrangement being suitable for blue emission.Here,we present an approach to polymer design that makes it possible to solve this problem.We demonstrate the in situ formation of a TADF donor-acceptor system during Suzuki polycondensation,creating an extended carbazole-based donor matrix coupled with a triazine acceptor.The resulting polymer exhibited efficient TADF with a low energy gap(ΔE_(ST))value if a phenyl N-substituent,enabling essential electron delocalization,was present in the carbazole moiety.This work establishes a versatile platform for developing carbazole-based TADF polymers,overcoming the fundamental limitations that hinder their widespread application.
基金This work was supported by the Laser Technique Innovation Foundation of China under Grant No. 20030509.
文摘The phase-conjugation characteristics of stimulated thermal scattering (STS) in absorbing liquid and stimulated Brillouin scattering (SBS) separately excited in pure acetone were compared, and the effect of focal pumping conditions on them was studied. It is shown that high-quality phase conjugation can be obtained by STS in absorbing liquid under stronger pumping conditions.
基金the framework of the IGC SB RAS project(No.0284-2021-0003)supported by the RFFR ofi_m project(No.17-29-05022).
文摘Several conjugate components represent the aquatic ecosystem of Lake Baikal:Baikal water(surface and deep water),groundwater from boreholes,water of numerous Baikal tributaries,cold and hot mineral springs around Lake Baikal,and the Angara River,the only runoff reflecting all this aquatic diversity.River waters in the Baikal region are known to be deficient in some vital elements,including fluorine.This article discusses the features of the fluorine distribution in the water from the conjugate components of the Baikal ecosystem.Fluorine ion concentrations in the water of the Baikal ecosystem was determined using the potentiometric method.The study represents the monitoring that was carried out between 1997 and 2022 years.We determine likely causes of high and low fluorine concentrations in the water from different components,propose and substantiate the fluorine sources,geological and geochemical model of its influx and distribution features in the water of the Baikal ecosystem.
基金supported by the Russian Science Foundation(23-29-00830).
文摘Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the interface,further growth of hydrate due to the suction of water in the capillary system formed between the wall of the cuvette and the end boundary of the hydrate layer occurs.Most probably,substantial effects on the formation of this capillary system may be caused by variations in reactor wall properties,for example,hydrophobic-hydrophilic balance,roughness,etc.We found,that the rate of CO_(2) hydrate film growth on the surface of the humic acid aqueous solution is 4-fold to lower in comparison with the growth rate on the surface of pure water.We suppose that this is caused by the adsorption of humic acid associates on the surface of hydrate particles and,as a consequence,by the deceleration of the diffusion of dissolved carbon dioxide to the growing hydrate particle.
文摘The southern part of East Siberia(SES)is highly vulnerable to flooding caused by the extreme precipitation events(EPEs)during summer.Building on previously detected EPEs in SES and Mongolia,we examined wave propagation patterns for two periods:1982-98 and 1999-2019.Our analysis revealed distinct wave train configurations and geopotential anomalies preceding EPEs,with an increase in wave activity flux across the Northern Hemisphere,followed by a subsequent decrease during EPEs.Consequently,Eastern Siberia has experienced a significant rise in wave activity.Based on geopotential anomalies over Central Siberia accompanying EPEs,we identified two main types.The first,the ridge type,is predominant during the first period and features a meridional contrast with a positive geopotential(and temperature)anomaly over Central Siberia and a negative anomaly over the subtropical regions along the same longitude.The second type,termed the trough type,is more typical for the second period.It involves either a negative geopotential anomaly or the zonal proximity of positive and negative geopotential anomalies over Central Siberia.The trough type,marked by zonally oriented anomalies in geopotential and temperature,results in a more pronounced temperature decrease before EPEs and significant zonal temperature contrasts.Further,it is related to more stationary waves over Northern Eurasia,with persistent positive geopotential anomalies over Europe linked to quasi-stationary troughs over Central Siberia and positive anomalies east of Lake Baikal.Our findings align with shifts in boreal summer teleconnection patterns,reflecting significant changes in wave propagation patterns that have occurred since the late 1990s.
文摘Type 2 diabetes mellitus(T2DM)significantly elevates the risk of colorectal cancer(CRC)and complicates its treatment by promoting chemoresistance.Poor glycemic control has been linked to exacerbated CRC progression and diminished chemotherapy efficacy,impacting patient outcomes through various mechanisms such as oxidative stress,activation of metabolic pathways,and altered protein modifications that hinder apoptosis and enhance tumor survival.Clinical evidence shows that T2DM patients experience higher rates of chemoresistance and reduced disease-free survival and overall survival compared to non-diabetic patients.Specifically,those with poor glycemic control exhibit increased chemo-resistance and poorer survival metrics.Antidiabetic treatments,including metformin,acarbose,and gliclazide,show promise in improving chemotherapy response and glycemic management,potentially enhancing patient outcomes.Addressing this challenge requires a comprehensive,multidisciplinary approach involving oncologists,endocrino-logists,and surgeons to optimize patient care.Integrated strategies that prioritize glycemic control are essential for reducing chemoresistance and improving survival in CRC patients with T2DM.
基金Project supported by Russian Science Foundation(22-73-00106)partly by NIIC project(121031700313-8,M.Rakhmanova,PL kinetics study)。
文摘The growing demand for luminescent nanomaterials intended for various applications increases the necessity to develop and improve approaches to the creation of highly efficient nanosized phosphors.In current study,an approach to enhancing the efficiency of red luminescence of monoclinic Y_(2)O_(3):Eu^(3+)with the particle size of~20 nm by creating the oxygen-enriched environment during the gas-phase synthesis was developed.To investigate the effect of oxygen amount during the synthesis on characteristics of the phosphor,a series of nano structured Y_(2)O_(3):Eu^(3+)with the addition of 0-40 vol%O_(2) to the main buffer gas Ar was synthesized by laser vaporization.It is shown that the amount of added O_(2) exerts virtually no effect on the phase composition and particle size,but significantly improves the luminescent characteristics of Y_(2)O_(3):Eu^(3+).Thus,the addition of 30 vol%O_(2) leads to virtually a 20-fold growth in the photoluminescence(PL)intensity caused by ^(5)D_(0)→^(7)F_(0-4) transitions in Eu^(3+)and an increase in the absolute PL quantum yield from 3%to 53%(λex=395 nm)compared to the sample synthesized without O_(2).The addition of oxygen also improves the emission color coordinates from(0.571,0.320)to(0.630,0.322)due to the removal of a considerable fraction of oxygen vacancies.The synthesized nanopowders are shown to be highly stable:upon storage under ambient conditions for two years.Quantum yield(QY)of the samples decreases by less than 2%.It is expected that the key features underlying the proposed approach will be useful for various methods used to synthesize oxide nanophosphors.
基金supported by Inga N.Zaitseva“Karanahan”LLC and the Ministry of Science and Higher Education of the Russian Federation via the Institute of Cytology and Genetics(State Budget Project No.FWNR-2022-0016).
文摘Objectives:Currently,there exist two approaches to the treatment of malignant neoplasms:the Karanahan technology and in situ vaccination,which are based on chronometric delivery of therapeutic agents to the tumor depending on the characteristics of tumor cells,as well as the immune status.The main purpose of this study was to experimentally prove the feasibility of combining the Karanahan technology and in situ vaccination withαOX40 antibodies into a single therapeutic platform to achieve a potent additive antitumor therapeutic effect.Methods:BALB/c mice grafted with B-cellular lymphoma A20 were treated using the Karanahan technology consisting of intraperitoneal cyclophosphamide administrations and intratumoral DNA injections according to an individually determined therapeutic regimen,together with in situ vaccination withαOX40.A pathomorphological analysis of the organs of experimental animals that died during the initial attempt to combine the two technologies was carried out.An analysis of blood cell populations was performed to determine the safe time for antibody administration:the number of immune cells capable of activating systemic inflammation(CD11b+Ly-6C+,CD11b+Ly-6G+,CD3–NKp46+CD11b+),the presence of Fc receptor and OX40 on the surface of these cells,and the number of neutrophils activated to NETosis were analyzed.Based on the analysis results,the antitumor efficacy of various modes of combining the Karanahan technology and in situ vaccination was studied.Results:WhenαOX40 was administered 5 h after each treatment using the Karanahan technology,mass death of mice caused by systemic inflammation and multiple organ failure was observed.The state of blood cells after the treatment using the Karanahan technology at the time points corresponding to antibody injections was analyzed to elucidate the reasons for this effect.It was found that at some time points,there occurs activation of the immune system and a powerful release(up to 16%)of monocytes and granulocytes carrying Fc receptor and OX40 on their surface into blood;when interacting withαOX40,they can activate the lytic potential of these cells.Activation of neutrophils to NETosis was also observed.Based on these findings,a study was carried out in different time regimes to combine the Karanahan technology andαOX40 injections.WhenαOX40 was injected into the points of minimal release of myeloid cells into the blood,increased survival rate and the greatest antitumor efficacy were observed:37%of animals survived without relapses on day 100 after experiment initiation.Conclusions:The results obtained indicate that it is possible to combine the Karanahan technology and in situ vaccination withαOX40,with obligatory constant monitoring of the number of myeloid cells in peripheral blood to determine the safe time for antibody injection.
基金funded by the Russian Science Foundation,grant number 23-64-10007.
文摘The article presents the results of a study on the possibility of synthesizing biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate)[P(3HB-co-4HB)]from renewable waste fish oil(WFO)by the Cupriavidus necator B-10646 bacterium.For the first time,waste oil generated during the processing of Sprattus balticus in the pro-duction of sprats was used as the main carbon substrate for the synthesis of P(3HB-co-4HB),andε-caprolactone was used as a precursor instead of the more expensiveγ-butyrolactone.Samples of P(3HB-co-4HB)with a 4HB monomer content from 7.4 to 11.6 mol.%were synthesized,and values of the bacterial biomass yield and the total yield of the copolymer were comparable with the control(where butyric acid was used as carbon source).The following properties of the samples were studied:molecular weight,temperature characteristics,thermal behavior,isothermal crystallization of melts,and the formation of spherulites.The renewable fatty substrate of complex composition was used to synthesize samples of technologically advanced low-crystallinity P(3HB-co-4HB)with significant proportions of 4HB,without impairing the physicochemical properties of the polymer.The biotech-nological process involving the use of renewable WFO andε-caprolactone can be employed to reduce the costs of producing a promising“green”bioplastic and make it more affordable.
基金supported by the Russian Science Foundation(grant No.:23-44-00067).
文摘Understanding why elements are distributed in tree xylem in a particular way is a significant challenge in dendrochemistry.This study explored a hypothesis that metal elements in the xylem interact due to differences in physical properties such as ionic radius and ionization potential.Scots pine in an even-aged stand established during the early 1970s in eastern Siberia was the study species.Increment cores were taken from the north and south sides of trees and scanned with an X-ray fluorescent multi scanner.With the help of X-ray scanning,the following elements were analyzed:aluminum(Al),potassium(K),calcium(Ca),titanium(Ti),manganese(Mn),iron(Fe),copper(Cu),strontium(Sr)and zinc(Zn).Scanning data on the elements were split into early-wood and late-wood data for each year of growth.The following ratios were analyzed:Ca/Sr,Fe/Ca,Fe/Sr,Al/Cu,Al/Zn,Ti/Mn,and Mn/K.Among these,ones having a consistent pattern across tree rings,the ratios show a more or less dependable relationship:that an element shows a larger decrease(relative another element)that has a larger ionic radius and lower ionization potential.Hypothetically,this may be due to the advantage of an ion with smaller ionic radius and higher ionization potential under a deficit of accommodation centers in organic molecules.An experiment approach should be applied to clarify the relationships.
基金supported by the Russian Science Foundation,project no.23-14-00285。
文摘Melanomas are aggressive cancers,with a high rate of metastatic disease.Cutaneous(CM)and uveal(UM)melanomas are intrinsically different diseases,and most cell death inducers effective for CM do not function for UM.This is primarily due to the fact the eye is an immunologically privileged organ,and it fails to achieve the efficacy of immune checkpoint inhibitors(ICIs)comparable to that for CM.However,approaches utilizing specific melanomaassociated antigens are being developed for metastatic forms of CM and UM.The most promising to date are gp100 and tyrosinase related protein 1(TYRP1),primarily for the design of targeting chimeric molecules and for autologous T-/NK-cell products with a chimeric antigen receptor.The difference in the mutational profile of apoptosis-related genes in CM and UM also makes counterproductive the use of the same drugs re-activators of the intrinsic pathway of apoptosis.Therefore,the discovery of novel pathways of regulated cell death such as ferroptosis and cuproptosis may help in the development of new drugs for melanomas resistant to already available inducers of regulated cell death.Here we consistently discuss the latest advances in the therapy of melanomas,and above all-UM,which is classified as an orphan disease.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.ZD2022E007).
文摘The insufficient electrocatalytic activity and CO_(2)resistance hinder the application of cathode mate-rial for solid oxide fuel cells(SOFCs).In this study,we introduce a series of Pr-doped perovskite Bi_(0.8-x)Pr_(x)Ca_(0.2)FeO_(3-δ)(BPCF_(x),x=0,0.10,0.15,0.20)as candidate cathode materials,with a focus on its phase structure,oxygen desorption ability,catalytic activity,and electrochemical reduction kinetics.Among all the components,the Bi_(0.6)Pr_(0.2)Ca_(0.2)FeO_(3-δ)(BPCF0.20)catalyst shows impressive oxygen reduc-tion reaction(ORR)activity,with a low polarization resistance of 0.06Ωcm^(2)at 700℃and peak power density of 810 mW cm^(−2)at 800℃.Moreover,the BPCF0.20 cathode shows outstanding CO_(2)resistance in different CO_(2)concentrations(1%-10%)due to the larger average bond energy and higher relative acidity of Bi,Pr,and Fe ions.These findings demonstrate that BPCF_(x)are advanced cathode electrocatalysts for SOFCs.
基金support from the Biotechnology and Biological Council Doctoral Training Programme(BBSRC DTP)the support from the Royal Society and Wolfson Foundation(RSWF\FT\191022).
文摘Nonlinear wavefront shaping is crucial for advancing optical technologies,enabling applications in optical computation,information processing,and imaging.However,a significant challenge is that once a metasurface is fabricated,the nonlinear wavefront it generates is fixed,offering little flexibility.This limitation often necessitates the fabrication of different metasurfaces for different wavefronts,which is both time-consuming and inefficient.To address this,we combine evolutionary algorithms with spatial light modulators(SLMs)to dynamically control wavefronts using a single metasurface,reducing the need for multiple fabrications and enabling the generation of arbitrary nonlinear wavefront patterns without requiring complicated optical alignment.We demonstrate this approach by introducing a genetic algorithm(GA)to manipulate visible wavefronts converted from near-infrared light via third-harmonic generation(THG)in a silicon metasurface.The Si metasurface supports multipolar Mie resonances that strongly enhance light-matter interactions,thereby significantly boosting THG emission at resonant positions.Additionally,the cubic relationship between THG emission and the infrared input reduces noise in the diffractive patterns produced by the SLM.This allows for precise experimental engineering of the nonlinear emission patterns with fewer alignment constraints.Our approach paves the way for self-optimized nonlinear wavefront shaping,advancing optical computation and information processing techniques.
文摘Oxidative coupling of methane(OCM)is a catalytic partial oxidation process that directly converts methane into C_(2) products.For this high temperature reaction,understanding the radical behavior through experimental investigation is important in correlating the catalytic activity and the products.In this work,a spatial resolution online mass spectrometry(MS)system was developed and applied to a Mn-Na_(2)WO_(4)/SiO_(2) catalyzed OCM system.In addition to the residue gas analysis,the system obtained the distribution information of the reactants and products in the reactor.At various setting temperatures,all species online MS signals were collected at different positions,mapping the reaction activity covering parameters including temperature,time and space.The distribution behavior of the catalytic activity,selectivity,and apparent activation energy were kinetically analyzed.Selectivity and additional carbon balance analysis strongly supported the radical coupling model of OCM and indicated that after the catalytic bed layer,there is a significant length in the reactor(>2 mm)filled with radicals.Based on the result,a designed new method by tuning the temperature field in the reactor was found effectively to improve the catalytic activity,especially the C_(2) yield from 702 to 773℃.
基金supported by funds from the National Key Research and Development Program of China(Grant No.2024YFF0807302)National Natural Science Foundation of China(42273043,42173003)the International Visiting Professorship of USTC(2024BVR23).
文摘Jadeitites are formed either through direct precipitation from Na-Al-Si rich fluids(P-type),or by replacement of magmatic protoliths(R-type)in subduction zones.They are valuable targets for investigating the mobility behavior and chemical composition of subduction zone fluids.The Rio San Juan Complex(RSJC)in the northern Dominican Republic hosts both P-and R-type jadeitites and jadeite-rich rocks,which provide ideal samples for addressing such issues.Here,we present trace element and Sr-Nd-O-Si isotope compositions of RSJC jadeitites and related rocks.Most samples show similar REE patterns,trace element distributions and δ^(18)O values to those of plagiogranite protoliths,indicating the predominance of R-type origin in RSJC.The P-type samples exhibit slightly higherδ^(30)Si values(−0.15‰to 0.25‰)than that of R-type samples(−0.20‰to 0.08‰),which place above the igneous array.The low(^(87)Sr/^(86)Sr)_(i)(0.70346 to 0.70505)and highεNd(t)values(4.6 to 6.8)of the P-type jadeitites and quartzites,along with relatively lowδ^(18)O values(4.7‰to 6.4‰)of their forming fluids,indicate that the fluids are likely derived from the altered basaltic crust rather than from oceanic sediment.However,the estimated jadeitite-and quartzite-forming fluids exhibit distinctδ^(30)Si values(0.76‰to 0.99‰and-0.48‰to-0.08‰,respectively),implying an evolution of the fluids that modified the Si isotopic compositions.Since fluid metasomatism and related desilication process could have lowered the whole-rock δ^(30)Si values,the heavy Si isotope compositions of the R-type samples are produced from the external fluids.Combing Rayleigh distillation and binary mixing simulations,we propose that fluids derived from altered oceanic crust obtained high δ^(30)Si values after crystallization of minerals enriched in light Si isotopes.The P-type jadeitites are formed through direct precipitation from this fluid.As the plagiogranite protoliths were continuously replaced by this fluid,the formed R-type samples(jadeitites and quartzites)also exhibit high δ^(30)Si values.Such rocks could significantly alter the Si isotope compositions of local mantle when they are deeply subducted at convergent plate margins.
基金Project supported by the Science and Technology International Cooperation Project of Qinghai Province (2022-HZ-807)the Open Project Salt Lake Chemical Engineering Research Complex,Qinghai University (2023-DXSSZZ-04)。
文摘Er^(3+)-and Tm^(3+)-doped Ca_(x)Sr_(2-x)Nb_(2)O_(7)(C_(x)S_(2-x)N,x=0.6,0.8,1,0,1.2,1,4) phosphors with layered pe rovskite structure were designed.These phosphors exhibit a dominant emission peak at 549 nm under980 nm laser excitation,attributed to the^(4)S_(3/2)→^(4)I_(15/2)transition.By increasing the content of Ca^(2+),the crystal field regulation of rare earth ions is realized and the luminescence enhancement is induced,which is manifested by the increase of^(2)H_(11/2),^(4)S_(3/2)→^(4)I_(15/2)emission.Furthermore,the temperature sensing sensitivities of C_(0.6)S_(1.4)N:Er,Tm and C_(0.6)S_(1.4)N:Er,Tm based on non-thermally coupled energy levels were studied.Finally,an anti-counterfeiting imprint was prepared using phosphors,which have high brightness and excellent photothermal stability.This work not only confirms that closer ionic radii substitution enables to increase the electronic density of states,improve the crystal field symmetry and enhance the luminescence,but also provides a promising phosphor system for temperature sensing and anti-counterfeiting applications,opening up new prospects in the optimization of the optical properties of phosphors.
文摘The study by Dos Santos et al marks a significant advancement in understanding the genetics of colorectal polyposis,particularly within the underrepresented Brazilian population.Utilizing whole-exome sequencing in 27 patients with unexplained polyposis,the researchers identified 16 candidate genes in 44.4%of cases-an impressive outcome given strict exclusion criteria.Many identified variants were linked to the Wnt/β-catenin signaling pathway,reinforcing their biological relevance.However,the study underscores key challenges in genomic medicine,especially the gap between gene discovery and clinical application.A substantial proportion of variants(60.1%)were classified as of uncertain sig-nificance,and the absence of functional validation or segregation analysis limits clinical interpretation.Notably,the potential for oligogenic inheritance com-plicates traditional monogenic models of hereditary cancer risk.The study’s focus on a genetically diverse Brazilian cohort emphasizes the need for population-specific genomic resources and interpretation guidelines.Moving forward,func-tional studies,including organoid models,loss-of-heterozygosity analyses,and genotype-phenotype correlations,are essential to validate findings.Clinically,discovering novel candidate genes may inform future screening and testing pro-tocols,though careful consideration is needed to manage uncertain results.Overall,the study represents a critical step in polyposis genetics,highlighting both progress made and the work still required for clinical translation.
