Single-atom nanozymes(SAzymes)hold significant potential for tumor catalytic therapy,but their effectiveness is often compromised by low catalytic efficiency within tumor microenvironment.This efficiency is mainly inf...Single-atom nanozymes(SAzymes)hold significant potential for tumor catalytic therapy,but their effectiveness is often compromised by low catalytic efficiency within tumor microenvironment.This efficiency is mainly influenced by key factors including hydrogen peroxide(H_(2)O_(2))availability,acidity,and temperature.Simultaneous optimization of these key factors presents a significant challenge for tumor catalytic therapy.In this study,we developed a comprehensive strategy to refine single-atom catalytic kinetics for enhancing tumor catalytic therapy through dual-enzyme-driven cascade reactions.Iridium(Ir)SAzymes with high catalytic activity and natural enzyme glucose oxidase(GOx)were utilized to construct the cascade reaction system.GOx was loaded by Ir SAzymes due to its large surface area.Then,the dual-enzyme-driven cascade reaction system was modified by cancer cell membranes for improving biocompatibility and achieving tumor homologous targeting ability.GOx catalysis reaction could produce abundant H2O2 and lower the local p H,thereby optimizing key reaction-limiting factors.Additionally,upon laser irradiation,Ir SAzymes could raise local temperature,further enhancing the catalytic efficiency of dual-enzyme system.This comprehensive optimization maximized the performance of Ir SAzymes,significantly improving the efficiency of catalytic therapy.Our findings present a strategy of refining single-atom catalytic kinetics for tumor homologous-targeted catalytic therapy.展开更多
Topographic complexity supports the maintenance of a high diversity of microhabitats,which may act as important‘safe havens’-or microrefugia-for biodiversity.Microrefugia are sites with specific environmental condit...Topographic complexity supports the maintenance of a high diversity of microhabitats,which may act as important‘safe havens’-or microrefugia-for biodiversity.Microrefugia are sites with specific environmental conditions that facilitate the persistence of species during environmental changes and exhibit unique ecoevolutionary dynamics.However,our knowledge about how topographic complexity and related ecoevolutionary selective forces influence the functional and phylogenetic signatures of species assemblages in microrefugia is very limited.Although the conceptual framework on the systematic integration of plant functional traits into the study of refugia is well established,more empirical studies on functional trait composition and functional diversity in refugia are urgently needed for more effective conservation.Here we analyzed the distribution of various plant functional traits and phylogenetic patterns in microhabitats(south-and north-facing slopes,and bottoms)of 30 large topographic depressions(i.e.doline microrefugia)and microhabitats of the surrounding plateaus in two distant forested karst regions.We found that plant assemblages in the understory of dolines and their surroundings are characterized by unique functional values and combinations of traits.Doline bottoms had the highest functional diversity among doline microhabitats and supported plant assemblages with considerably different trait compositions from the plateaus.Bottoms also had the highest phylogenetic diversity.These results suggest that topographic complexity in forested dolines has a significant effect on the distribution of plant functional traits in the understory.High functional and phylogenetic diversity in doline bottoms can have important consequences for the long-term survival of plant populations,highlighting that these microhabitats may provide a higher resilience and support an adaptive community-level response to natural and anthropogenic stressors.Understanding mechanisms that drive the survival of species within microrefugia is required to determine the best conservation and management strategies.展开更多
The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging issue.In this work,a series of diacetylene monomers(...The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging issue.In this work,a series of diacetylene monomers(m-PCDA)containing phenyl and amide or carboxyl groups were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the esterification or amidation reactions.The effects of the number and the distribution of the functional groups in m-PCDA molecules on their solid-state polymerization capability,and the thermochromic mechanism of their corresponding polymers(m-PDA)were investigated and discussed in detail.The results show that the m-PCDA monomers containing both benzene ring and groups that can form hydrogen bonding interactions have strong intermolecular interaction,and are easy to carry out the solid phase polymerization under 254-nm UV irradiation to obtain the corresponding new thermochromic m-PDA materials.The thermochromic behavior of m-PDA depends on its melting process.The initial color-change temperature(blue to red)is determined by the onset melting tem perature,and the temperature range in which reversible color recovery can be achieved by repeat heating-cooling treatment is determined by its melting range.According to the proposed thermochromic mechanism of PDA,various new PDA materials with precise thermochromic temperatu res and reversible thermochromic temperature ra nges can be designed and synthesized through the appropriate introduction of benzene ring and groups that can form hydrogen bonding interactions into the molecular structure of linear diacetylene monomer.This work provides a perspective to the precise molecular structure design and the property regulation of the reversible thermochromic PDA materials.展开更多
The aim of the research is to increase the applicability of lipopeptides as drugs.To this end,non-ionic triblock copolymers,namely poloxamers,were applied.The physico-chemical properties of poloxamers vary depending o...The aim of the research is to increase the applicability of lipopeptides as drugs.To this end,non-ionic triblock copolymers,namely poloxamers,were applied.The physico-chemical properties of poloxamers vary depending on the length of the blocks.In our study,we experimented with different types and systematically investigated the variation of the critical micelle concentration(CMC)of poloxamers at 25 and 37°C in different media.In addition,the cytotoxicity of the different poloxamer micelles on three different cell lines was evaluated,and based on the results,Plur104,Plur123,and Plur127 were selected.Fatty acid elongated derivatives of a short antibacterial peptide(pL1),a medium-sized anticancer peptide(pCM15),and a branched-chain vaccine antigen(pATIPC)were used as lipopeptide models,and their formulations with the selected poloxamers were investigated.The solubility and homogeneity of the lipopeptides were significantly increased,and dynamic light scattering(DLS)measurements showed the formation of small particles of around 20 nm,which were well reproducible and storable.Similar homogenous micelle formation was observed after freeze-drying and reconstitution with water.The pL1 lipopeptide,formulated with the selected poloxamers,exhibited enhanced antibacterial activity with significantly reduced haemolytic side effects.The pCM15 peptide,when incorporated into poloxamer micelles,showed significantly enhanced cytotoxicity against tumor cells.Additionally,the internalization rate of poloxamer-formulated pATIPC peptide by antigen-presenting model cells exceeded that of the unformulated peptide.Our results demonstrate the potential of poloxamers as promising tools for the formulation of lipopeptides and for the optimization of their selectivity.展开更多
We developed flame retarded polyimine type vitrimers and carbon fibre reinforced composites using two additive and a reactive flame retardant containing phosphorus:ammonium polyphosphate(APP),resorcinol bis(diphenyl p...We developed flame retarded polyimine type vitrimers and carbon fibre reinforced composites using two additive and a reactive flame retardant containing phosphorus:ammonium polyphosphate(APP),resorcinol bis(diphenyl phosphate)(RDP);and N,N’,N’’-tris(2-aminoethyl)-phosphoric acid triamide(TEDAP).We characterised the vitrimer matrix materials by differential scanning calorimetry(DSC),thermal analysis(TGA),limiting oxygen index(LOI),UL-94 test and mass loss calorimetry(MLC),while the vitrimer composites by LOI,UL-94 test,MLC and dynamic mechanical analysis(DMA).We compared the performance of the vitrimer systems to a benchmark pentaerythritol-based aliphatic epoxy resin system(PER).The vitrimer reference had higher thermal stability but lower fire performance than the PER aliphatic reference epoxy.At lower phosphorus content,the vitrimer systems exhibited a melting above their vitrimer transition temperature,which negatively affected their LOI and UL-94 results.From 2%phosphorus content,rapid charring and extinguishing of vitrimers prevented the softening and deforming.The superior performance of these same flame retardants in vitrimer systems could be attributed to the high nitrogen content of imine-based vitrimers in combination with phosphorus flame retardants,exploiting nitrogen-phosphorus synergism.In both matrices,flame retardants with solid phase action lead to better fire performance,while in composites,the lowest peak heat release rates(152 kW/m2 in vitrimer composite)were achieved with RDP acting predominantly in the gas phase,as carbon fibres hindered the intumescent phenomenon.展开更多
Gold nanovesicles(GVs) with unique plasmonic property and large cavity hold great potential as a stimuli-responsive nanocarrier to deliver drugs for efficient tumor chemotherapy and other therapies synergistically.Her...Gold nanovesicles(GVs) with unique plasmonic property and large cavity hold great potential as a stimuli-responsive nanocarrier to deliver drugs for efficient tumor chemotherapy and other therapies synergistically.Herein,we developed doxorubicin-loaded gold nanovesicles(DGVs),offering infrared thermal(IRT) and photoacoustic(PA) dual-modal imaging guided mild hype rthermia-enhanced chemophotothermal cancer synergistic therapy.The DGVs are self-assembled by gold nanoparticles modified with amphiphilic copolymer in a predetermined concentration of doxorubicin through film rehydration method.Under the influence of laser excitation,the as-prepared DGVs exhibited good photothermal effect,which triggered the structural disruption of GVs and thus,allowed the efficient release of encapsulated DOX to enhance cell uptake for fluorescence imaging and tumor chemotherapy,respectively.In addition,DGVs also showed a strong PA and IRT signals in vivo.Our study demonstrated the potential of DGVs as stimuli-responsive drug delivery systems and cancer theranostics.展开更多
The identification of individual factors modulating clinical recovery after a stroke is fundamental to personalize the therapeutic intervention to enhance the final clinical outcome.In this framework,electrophysiologi...The identification of individual factors modulating clinical recovery after a stroke is fundamental to personalize the therapeutic intervention to enhance the final clinical outcome.In this framework,electrophysiological factors are promising since are more directly related to neuroplasticity,which supports recovery in stroke patients,than neurovascular factors.In this retrospective observational study,we investigated brain neuronal activity assessed via spectral features and Higuchi's fractal dimension(HFD) of electroencephalographic signals in acute phase(2–10 days from symptom onset,T0) and sub-acute phase(2.5 months,T1) in 24 patients affected by unilateral middle cerebral artery stroke.Longitudinal assessment of the clinical deficits was performed using the National Institutes of Health Stroke Scale(NIHSS),together with the effective recovery calculated as the ratio between difference of NIHSS at T0 and T1 over the NIHSS value at T0.We observed that delta and alpha band electroencephalographic signal power changed between the two phases in both the hemispheres ipsilateral(ILH) and contralateral(CHL) to the lesion.Moreover,at T0,bilateral higher delta band power correlated with worse clinical conditions(Spearman's rs = 0.460,P = 0.027 for ILH and rs = 0.508,P = 0.013 for CLH),whereas at T1 this occurred only for delta power in ILH(rs = 0.411,P = 0.046) and not for CHL.Inter-hemispheric difference(ILH vs.CLH) of alpha power in patients was lower at T0 than at T1(P = 0.020).HFD at T0 was lower than at T1(P = 0.005),and at both phases,ILH HFD was lower than CLH HFD(P = 0.020).These data suggest that inter-hemispheric low band asymmetry and fractal dimension changes from the acute to the sub-acute phase are sensitive to neuroplasticity processes which subtend clinical recovery.The study protocol was approved by the Bioethical Committee of Ospedale San Giovanni Calibita Fatebenefretelli(No.40/2011) on July 14,2011.展开更多
The Berezitovoe deposit in the Sergachi volcano-plutonic and metallogenic belt preserves evidence for polymetallic mineralization of multiple stages.The steeply dipping gamet-tourmaline-muscovite-quartz metasomatites...The Berezitovoe deposit in the Sergachi volcano-plutonic and metallogenic belt preserves evidence for polymetallic mineralization of multiple stages.The steeply dipping gamet-tourmaline-muscovite-quartz metasomatites（with K-Ar ages of 132 ± 2.9 and 127 ± 4.4 Ma） carry two distinct stages of mineralization developed at different times：（1） polymetallic mineralization and（2） gold-quartz.The deposit is located within Paleozoic gneissose granitoids of the Pikansky complex（dated as 379 ± 1.1 Ma by zircon U-Pb method） intruded by early Cretaceous porphyry-like granites of the Haikta pluton（dated as137 ± 0.67 Ma by zircon U-Pb method） and late Cretaceous dikes of porphyrites,porphyries,and lamprophyres.Evidence suggests the action of late gold-bearing hydrothermal fluids on the early polymetallic ores and the selective mobilization of some elements from these lead to redeposition together with complex sulphosalts.展开更多
Let f be a holomorphic function on a domain D (?) C, and let a be a finite complex number. We denote by Ef(α) = {z∈ D : f(z) = a, ignoring multiplicity} the set of all distinct α-points of f. Let F be a family of h...Let f be a holomorphic function on a domain D (?) C, and let a be a finite complex number. We denote by Ef(α) = {z∈ D : f(z) = a, ignoring multiplicity} the set of all distinct α-points of f. Let F be a family of holomorphic functions on D. If there exist three finite values a, b(≠ 0, a) and c(≠0) such that for every f ∈ F, Ef(0) (?) Ef'(a) and Ef'(b)(?) Ef(c), then F is a normal family on D.展开更多
Let {(Xi, Si, μi) : i ℃ N} be a sequence of probability measure spaces and (*Xi, L(*Si), L(*μi)) be the Loeb measure space with respect to (Xi, Si, μi) for i ℃ N. Let X =× Xi, S = ×Si,μ = ×μi. We...Let {(Xi, Si, μi) : i ℃ N} be a sequence of probability measure spaces and (*Xi, L(*Si), L(*μi)) be the Loeb measure space with respect to (Xi, Si, μi) for i ℃ N. Let X =× Xi, S = ×Si,μ = ×μi. We prove that × L(*Si) CL(*S) and in embedding meaning.展开更多
A group of G.hirsutum L.varieties and theirhybrids F<sub>1</sub> were studied on two fields withdifferent mineral supply conditions:optimalmineral supply and without fertilizers.Thereliable genotypic intra...A group of G.hirsutum L.varieties and theirhybrids F<sub>1</sub> were studied on two fields withdifferent mineral supply conditions:optimalmineral supply and without fertilizers.Thereliable genotypic intraspecies polymorphism ofresponse to the different level of mineralnutrition was identified.An individual展开更多
The reproductive,adaptive heterosis andeconomically-valuable traits of hybrids F<sub>1</sub>,F<sub>2</sub>and F<sub>3</sub> obtained as a result intraspecific crossingG.hirsutum L.p...The reproductive,adaptive heterosis andeconomically-valuable traits of hybrids F<sub>1</sub>,F<sub>2</sub>and F<sub>3</sub> obtained as a result intraspecific crossingG.hirsutum L.parents with ordinary type ofleaves and imported Okra-leaves parents hadbeen studied.Perspective of use of cotton展开更多
Phosphatase plays a vital important role in many biological functions due to the dephosphorylation serves varied roles in cellular regulation and signaling.Among the family of phosphatase,alkaline phosphatase(ALP)coul...Phosphatase plays a vital important role in many biological functions due to the dephosphorylation serves varied roles in cellular regulation and signaling.Among the family of phosphatase,alkaline phosphatase(ALP)could act as crucial prognostic indicators for many diseases such as bone diseases and cancer.However,the detection of ALP is mainly limited to in vitro colorimetric method in clinic.Therefore,huge efforts have been paid on the fluorescence imaging that provides a reliable method to detect the real-time and in vivo changes of the level of ALP.In this review,we summarize recent advances in fluorescence imaging of phosphatase,mainly focused on ALP.The imaging probes of phosphatase are mainly classified according to their luminescence mechanisms.In the end,we assessed the challenges and future prospects of phosphatase probes.展开更多
The hollow core photonic crystal waveguide biosensor is designed and described.The biosensor was tested in experiments for artificial sweetener identifcation in drinks.The photonic crystal waveguide biosensor has a hi...The hollow core photonic crystal waveguide biosensor is designed and described.The biosensor was tested in experiments for artificial sweetener identifcation in drinks.The photonic crystal waveguide biosensor has a high sensitivity to the optical properties of liquids flling up the hollow core.The compactness,good integration ability to different optical systems and compatibility for use in industrial settings make such biosensor very promnising for v arious biomedical applicat ions.展开更多
In this work, we suggest a system for chaos-based encryption of electrocardiographic signals. It uses simple electronics organized around a colpitts chaotic oscillator. The system has been designed, implemented and te...In this work, we suggest a system for chaos-based encryption of electrocardiographic signals. It uses simple electronics organized around a colpitts chaotic oscillator. The system has been designed, implemented and tested. The encrypted signal has been decrypted and compared to the original ECG signal. Experimental results were analysed and proved encouraging.展开更多
The system ＂substrate--graphene island on its surface＂ was modeled with using semi-empirical quantum chemistry methods for various substrates. Such system imitates the graphene nucleation and growth when using CVD ...The system ＂substrate--graphene island on its surface＂ was modeled with using semi-empirical quantum chemistry methods for various substrates. Such system imitates the graphene nucleation and growth when using CVD （chemical vapor deposition） technique. Herewith the carbon atoms can enter the island from both the substrate and the bulk of the CVD reactor. The authors show that for a wide island size range the carbon nanowalls placed perpendicularly as to the substrate is the most favorable configuration. But a transfer to this configuration is only possible providing two conditions are realized： the CVD technique is stimulated by plasma, when a strong electrical field exists near the substrate surface and preliminary decomposition of carbon carrier is realized in the bulk of the CVD-reactor.展开更多
Contour is an important pattern descriptor in image processing and particularly in region description, registration and length estimation. In many applications where contour is used, a good segmentation and an efficie...Contour is an important pattern descriptor in image processing and particularly in region description, registration and length estimation. In many applications where contour is used, a good segmentation and an efficient smoothing method are needed. In X-ray images, such as mammograms, where object edge is not clearly discernible, estimating the object’s contour may yield substantial shift along the boundary due to noise or segmentation drawbacks. An appropriate smoothing is therefore required to reduce these effects. In this paper, an approach based on local adaptive threshold segmentation to extract contour and a new smoothing approach founded on Fourier descriptors are introduced. The experimental results of extraction obtained from a set of mammograms and compared with the breast regions delineated by radiologists yielded a percent overlap area of 98.7% ± 0.9% with false positive and negative rates of 0.36 ± 0.74 and 0.93 ± 0.44 respectively. The proposed method was tested on a set of images and improved the accuracy, leading to an average error of less than one pixel.展开更多
Blindness which is considered as degrading disabling disease is the final stage that occurs when a certain threshold of visual acuity is overlapped. It happens with vision deficiencies that are pathologic states due t...Blindness which is considered as degrading disabling disease is the final stage that occurs when a certain threshold of visual acuity is overlapped. It happens with vision deficiencies that are pathologic states due to many ocular diseases. Among them, diabetic retinopathy is nowadays a chronic disease that attacks most of diabetic patients. Early detection through automatic screening programs reduces considerably expansion of the disease. Exudates are one of the earliest signs. This paper presents an automated method for exudates detection in digital retinal fundus image. The first step consists of image enhancement. It focuses on histogram expansion and median filter. The difference between filtered image and his inverse reduces noise and removes background while preserving features and patterns related to the exudates. The second step refers to blood vessel removal by using morphological operators. In the last step, we compute the result image with an algorithm based on Entropy Maximization Thresholding to obtain two segmented regions (optical disk and exudates) which were highlighted in the second step. Finally, according to size criteria, we eliminate the other regions obtain the regions of interest related to exudates. Evaluations were done with retinal fundus image DIARETDB1 database. DIARETDB1 gathers high-quality medical images which have been verified by experts. It consists of around 89 colour fundus images of which 84 contain at least mild non-proliferative signs of the diabetic retinopathy. This tool provides a unified framework for benchmarking the methods, but also points out clear deficiencies in the current practice in the method development. Comparing to other recent methods available in literature, we found that the proposed algorithm accomplished better result in terms of sensibility (94.27%) and specificity (97.63%).展开更多
This paper provides an overview of the main recommendations and approaches of the methodology on parallel computation application development for hybrid structures. This methodology was developed within the master＇s ...This paper provides an overview of the main recommendations and approaches of the methodology on parallel computation application development for hybrid structures. This methodology was developed within the master＇s thesis project ＂Optimization of complex tasks＇ computation on hybrid distributed computational structures＂ accomplished by Orekhov during which the main research objective was the determination of＂ patterns of the behavior of scaling efficiency and other parameters which define performance of different algorithms＇ implementations executed on hybrid distributed computational structures. Major outcomes and dependencies obtained within the master＇s thesis project were formed into a methodology which covers the problems of applications based on parallel computations and describes the process of its development in details, offering easy ways of avoiding potentially crucial problems. The paper is backed by the real-life examples such as clustering algorithms instead of artificial benchmarks.展开更多
基金financially supported by National Natural Science Foundation of China(U23A2097,82372116,22474079,22104094,82302362)Shenzhen Medical Research Fund(B2302047)+3 种基金Basic Research Program of Shenzhen(KQTD20190929172538530,JCYJ20220818095806014,JCYJ20240813142810014)Natural Science Foundation of Guangdong Province(2024A1515012677)Research Team Cultivation Program of Shenzhen University(2023QNT017,2023QNT019)Shenzhen University 2035 Program for Excellent Research(2024C004)。
文摘Single-atom nanozymes(SAzymes)hold significant potential for tumor catalytic therapy,but their effectiveness is often compromised by low catalytic efficiency within tumor microenvironment.This efficiency is mainly influenced by key factors including hydrogen peroxide(H_(2)O_(2))availability,acidity,and temperature.Simultaneous optimization of these key factors presents a significant challenge for tumor catalytic therapy.In this study,we developed a comprehensive strategy to refine single-atom catalytic kinetics for enhancing tumor catalytic therapy through dual-enzyme-driven cascade reactions.Iridium(Ir)SAzymes with high catalytic activity and natural enzyme glucose oxidase(GOx)were utilized to construct the cascade reaction system.GOx was loaded by Ir SAzymes due to its large surface area.Then,the dual-enzyme-driven cascade reaction system was modified by cancer cell membranes for improving biocompatibility and achieving tumor homologous targeting ability.GOx catalysis reaction could produce abundant H2O2 and lower the local p H,thereby optimizing key reaction-limiting factors.Additionally,upon laser irradiation,Ir SAzymes could raise local temperature,further enhancing the catalytic efficiency of dual-enzyme system.This comprehensive optimization maximized the performance of Ir SAzymes,significantly improving the efficiency of catalytic therapy.Our findings present a strategy of refining single-atom catalytic kinetics for tumor homologous-targeted catalytic therapy.
基金funded by the National Research,Development and Innovation Office(NKFIH FK 142428 grant)The contribution of Z.B.was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences and by the New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research,Development and Innovation Fund(ÚNKP-23-5-SZTE-697)+2 种基金K.F.was supported by the New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research,Development and Innovation Fund(ÚNKP-23-3-SZTE-441)C.T.was supported by the NKFIH K 146137 grantA.E-V.was supported by the long-term research development project of the Czech Academy of Sciences(RVO 67985939).
文摘Topographic complexity supports the maintenance of a high diversity of microhabitats,which may act as important‘safe havens’-or microrefugia-for biodiversity.Microrefugia are sites with specific environmental conditions that facilitate the persistence of species during environmental changes and exhibit unique ecoevolutionary dynamics.However,our knowledge about how topographic complexity and related ecoevolutionary selective forces influence the functional and phylogenetic signatures of species assemblages in microrefugia is very limited.Although the conceptual framework on the systematic integration of plant functional traits into the study of refugia is well established,more empirical studies on functional trait composition and functional diversity in refugia are urgently needed for more effective conservation.Here we analyzed the distribution of various plant functional traits and phylogenetic patterns in microhabitats(south-and north-facing slopes,and bottoms)of 30 large topographic depressions(i.e.doline microrefugia)and microhabitats of the surrounding plateaus in two distant forested karst regions.We found that plant assemblages in the understory of dolines and their surroundings are characterized by unique functional values and combinations of traits.Doline bottoms had the highest functional diversity among doline microhabitats and supported plant assemblages with considerably different trait compositions from the plateaus.Bottoms also had the highest phylogenetic diversity.These results suggest that topographic complexity in forested dolines has a significant effect on the distribution of plant functional traits in the understory.High functional and phylogenetic diversity in doline bottoms can have important consequences for the long-term survival of plant populations,highlighting that these microhabitats may provide a higher resilience and support an adaptive community-level response to natural and anthropogenic stressors.Understanding mechanisms that drive the survival of species within microrefugia is required to determine the best conservation and management strategies.
基金financially supported by the National Natural Science Foundation of China(No.51973205)the Fundamental Research Funds for the Central Universities(Nos.WK9110000066,WK3450000005 and WK3450000006)。
文摘The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging issue.In this work,a series of diacetylene monomers(m-PCDA)containing phenyl and amide or carboxyl groups were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the esterification or amidation reactions.The effects of the number and the distribution of the functional groups in m-PCDA molecules on their solid-state polymerization capability,and the thermochromic mechanism of their corresponding polymers(m-PDA)were investigated and discussed in detail.The results show that the m-PCDA monomers containing both benzene ring and groups that can form hydrogen bonding interactions have strong intermolecular interaction,and are easy to carry out the solid phase polymerization under 254-nm UV irradiation to obtain the corresponding new thermochromic m-PDA materials.The thermochromic behavior of m-PDA depends on its melting process.The initial color-change temperature(blue to red)is determined by the onset melting tem perature,and the temperature range in which reversible color recovery can be achieved by repeat heating-cooling treatment is determined by its melting range.According to the proposed thermochromic mechanism of PDA,various new PDA materials with precise thermochromic temperatu res and reversible thermochromic temperature ra nges can be designed and synthesized through the appropriate introduction of benzene ring and groups that can form hydrogen bonding interactions into the molecular structure of linear diacetylene monomer.This work provides a perspective to the precise molecular structure design and the property regulation of the reversible thermochromic PDA materials.
基金support of the Lendület(Momentum)Programme of the Hungarian Academy of Sciences(Grant No.:LP2021-28)the National Research,Development and Innovation Fund of Hungary,financed under the 2018-1.2.1-NKP funding scheme(Project No.:2018-1.2.1-NKP-2018-00005)the National Research,Development and Innovation Office,NKFIH,Hungary(Grant Nos.:K131594,2020-1-1-2-PIACI-KFI_2020-00021,and TKP2021-EGA-31).
文摘The aim of the research is to increase the applicability of lipopeptides as drugs.To this end,non-ionic triblock copolymers,namely poloxamers,were applied.The physico-chemical properties of poloxamers vary depending on the length of the blocks.In our study,we experimented with different types and systematically investigated the variation of the critical micelle concentration(CMC)of poloxamers at 25 and 37°C in different media.In addition,the cytotoxicity of the different poloxamer micelles on three different cell lines was evaluated,and based on the results,Plur104,Plur123,and Plur127 were selected.Fatty acid elongated derivatives of a short antibacterial peptide(pL1),a medium-sized anticancer peptide(pCM15),and a branched-chain vaccine antigen(pATIPC)were used as lipopeptide models,and their formulations with the selected poloxamers were investigated.The solubility and homogeneity of the lipopeptides were significantly increased,and dynamic light scattering(DLS)measurements showed the formation of small particles of around 20 nm,which were well reproducible and storable.Similar homogenous micelle formation was observed after freeze-drying and reconstitution with water.The pL1 lipopeptide,formulated with the selected poloxamers,exhibited enhanced antibacterial activity with significantly reduced haemolytic side effects.The pCM15 peptide,when incorporated into poloxamer micelles,showed significantly enhanced cytotoxicity against tumor cells.Additionally,the internalization rate of poloxamer-formulated pATIPC peptide by antigen-presenting model cells exceeded that of the unformulated peptide.Our results demonstrate the potential of poloxamers as promising tools for the formulation of lipopeptides and for the optimization of their selectivity.
基金Project no.TKP-6-6/PALY-2021 has been implemented with the support provided by the Ministry of CultureInnovation of Hungary from the National Research,Development and Innovation Fund,financed under the TKP2021-NVA funding scheme+4 种基金funded by the National Research,Development and In-novation Office(NKFIH K142517)This research has been imple-mented with the support of the 2021-1.2.4-TÉT-2021-00050,which encourages scientific and technological cooperation between USA and HungarySupport from theÚNKP-23-3-II-BME-227,ÚNKP-23-5-BME-409 andÚNKP-23-5-BME-417 New National Excellence Pro-gram of the Ministry for Culture and Innovation from the source of the National Research,Development and Innovation Fund is acknowledgedsupported by the János Bolyai Research Scholarship of the Hungarian Academy of Sci-ences No.BO/00508/22/6 and No BO/00980/23/7support of Bertalan Papp in preparation works.
文摘We developed flame retarded polyimine type vitrimers and carbon fibre reinforced composites using two additive and a reactive flame retardant containing phosphorus:ammonium polyphosphate(APP),resorcinol bis(diphenyl phosphate)(RDP);and N,N’,N’’-tris(2-aminoethyl)-phosphoric acid triamide(TEDAP).We characterised the vitrimer matrix materials by differential scanning calorimetry(DSC),thermal analysis(TGA),limiting oxygen index(LOI),UL-94 test and mass loss calorimetry(MLC),while the vitrimer composites by LOI,UL-94 test,MLC and dynamic mechanical analysis(DMA).We compared the performance of the vitrimer systems to a benchmark pentaerythritol-based aliphatic epoxy resin system(PER).The vitrimer reference had higher thermal stability but lower fire performance than the PER aliphatic reference epoxy.At lower phosphorus content,the vitrimer systems exhibited a melting above their vitrimer transition temperature,which negatively affected their LOI and UL-94 results.From 2%phosphorus content,rapid charring and extinguishing of vitrimers prevented the softening and deforming.The superior performance of these same flame retardants in vitrimer systems could be attributed to the high nitrogen content of imine-based vitrimers in combination with phosphorus flame retardants,exploiting nitrogen-phosphorus synergism.In both matrices,flame retardants with solid phase action lead to better fire performance,while in composites,the lowest peak heat release rates(152 kW/m2 in vitrimer composite)were achieved with RDP acting predominantly in the gas phase,as carbon fibres hindered the intumescent phenomenon.
基金financially supported by the National Natural Science Foundation of China (Nos.31771036,51703132)the Basic Research Program of Shenzhen (Nos.JCYJ20180507182413022,JCYJ20170412111100742)the Guangdong Province Natural Science Foundation of Major Basic Research and Cultivation Project (No.2018B030308003)。
文摘Gold nanovesicles(GVs) with unique plasmonic property and large cavity hold great potential as a stimuli-responsive nanocarrier to deliver drugs for efficient tumor chemotherapy and other therapies synergistically.Herein,we developed doxorubicin-loaded gold nanovesicles(DGVs),offering infrared thermal(IRT) and photoacoustic(PA) dual-modal imaging guided mild hype rthermia-enhanced chemophotothermal cancer synergistic therapy.The DGVs are self-assembled by gold nanoparticles modified with amphiphilic copolymer in a predetermined concentration of doxorubicin through film rehydration method.Under the influence of laser excitation,the as-prepared DGVs exhibited good photothermal effect,which triggered the structural disruption of GVs and thus,allowed the efficient release of encapsulated DOX to enhance cell uptake for fluorescence imaging and tumor chemotherapy,respectively.In addition,DGVs also showed a strong PA and IRT signals in vivo.Our study demonstrated the potential of DGVs as stimuli-responsive drug delivery systems and cancer theranostics.
基金FZ and FT obtained financial support from the Italian Ministry of Health Cod.GR-2008-1138642 "Promoting recovery from Stroke:individually enriched therapeutic intervention in Acute phase"PNR-CNR Aging Program
文摘The identification of individual factors modulating clinical recovery after a stroke is fundamental to personalize the therapeutic intervention to enhance the final clinical outcome.In this framework,electrophysiological factors are promising since are more directly related to neuroplasticity,which supports recovery in stroke patients,than neurovascular factors.In this retrospective observational study,we investigated brain neuronal activity assessed via spectral features and Higuchi's fractal dimension(HFD) of electroencephalographic signals in acute phase(2–10 days from symptom onset,T0) and sub-acute phase(2.5 months,T1) in 24 patients affected by unilateral middle cerebral artery stroke.Longitudinal assessment of the clinical deficits was performed using the National Institutes of Health Stroke Scale(NIHSS),together with the effective recovery calculated as the ratio between difference of NIHSS at T0 and T1 over the NIHSS value at T0.We observed that delta and alpha band electroencephalographic signal power changed between the two phases in both the hemispheres ipsilateral(ILH) and contralateral(CHL) to the lesion.Moreover,at T0,bilateral higher delta band power correlated with worse clinical conditions(Spearman's rs = 0.460,P = 0.027 for ILH and rs = 0.508,P = 0.013 for CLH),whereas at T1 this occurred only for delta power in ILH(rs = 0.411,P = 0.046) and not for CHL.Inter-hemispheric difference(ILH vs.CLH) of alpha power in patients was lower at T0 than at T1(P = 0.020).HFD at T0 was lower than at T1(P = 0.005),and at both phases,ILH HFD was lower than CLH HFD(P = 0.020).These data suggest that inter-hemispheric low band asymmetry and fractal dimension changes from the acute to the sub-acute phase are sensitive to neuroplasticity processes which subtend clinical recovery.The study protocol was approved by the Bioethical Committee of Ospedale San Giovanni Calibita Fatebenefretelli(No.40/2011) on July 14,2011.
基金the financial support of the Presidium and Far East Branch of the Russian Academy of Sciences (Grant No.15-1-2-019)the Russian Foundation for Basic Research(Grant No.15-05-00809)+1 种基金supported by the Talent Award to M.Santosh from the 1000 Plan of the Chinese Governmentthe Foreign Expert grants from China University of Geosciences(Beijing)
文摘The Berezitovoe deposit in the Sergachi volcano-plutonic and metallogenic belt preserves evidence for polymetallic mineralization of multiple stages.The steeply dipping gamet-tourmaline-muscovite-quartz metasomatites（with K-Ar ages of 132 ± 2.9 and 127 ± 4.4 Ma） carry two distinct stages of mineralization developed at different times：（1） polymetallic mineralization and（2） gold-quartz.The deposit is located within Paleozoic gneissose granitoids of the Pikansky complex（dated as 379 ± 1.1 Ma by zircon U-Pb method） intruded by early Cretaceous porphyry-like granites of the Haikta pluton（dated as137 ± 0.67 Ma by zircon U-Pb method） and late Cretaceous dikes of porphyrites,porphyries,and lamprophyres.Evidence suggests the action of late gold-bearing hydrothermal fluids on the early polymetallic ores and the selective mobilization of some elements from these lead to redeposition together with complex sulphosalts.
基金The NNSF (19871050) the RFDP (98042209) of China.
文摘Let f be a holomorphic function on a domain D (?) C, and let a be a finite complex number. We denote by Ef(α) = {z∈ D : f(z) = a, ignoring multiplicity} the set of all distinct α-points of f. Let F be a family of holomorphic functions on D. If there exist three finite values a, b(≠ 0, a) and c(≠0) such that for every f ∈ F, Ef(0) (?) Ef'(a) and Ef'(b)(?) Ef(c), then F is a normal family on D.
基金The Special Science Foundation (00jk207) of the Educational Committee of Shaanxi Province.
文摘Let {(Xi, Si, μi) : i ℃ N} be a sequence of probability measure spaces and (*Xi, L(*Si), L(*μi)) be the Loeb measure space with respect to (Xi, Si, μi) for i ℃ N. Let X =× Xi, S = ×Si,μ = ×μi. We prove that × L(*Si) CL(*S) and in embedding meaning.
文摘A group of G.hirsutum L.varieties and theirhybrids F<sub>1</sub> were studied on two fields withdifferent mineral supply conditions:optimalmineral supply and without fertilizers.Thereliable genotypic intraspecies polymorphism ofresponse to the different level of mineralnutrition was identified.An individual
文摘The reproductive,adaptive heterosis andeconomically-valuable traits of hybrids F<sub>1</sub>,F<sub>2</sub>and F<sub>3</sub> obtained as a result intraspecific crossingG.hirsutum L.parents with ordinary type ofleaves and imported Okra-leaves parents hadbeen studied.Perspective of use of cotton
基金supported by National Key Research and Development Program(No.2018YFA0704003)Basic Research Program of Shenzhen(Nos.JCYJ20170412111100742,JCYJ20180507182413022)+1 种基金Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(No.161032)Guangdong Province Natural Science Foundation of Major Basic Research and Cultivation Project(No.2018B030308003)。
文摘Phosphatase plays a vital important role in many biological functions due to the dephosphorylation serves varied roles in cellular regulation and signaling.Among the family of phosphatase,alkaline phosphatase(ALP)could act as crucial prognostic indicators for many diseases such as bone diseases and cancer.However,the detection of ALP is mainly limited to in vitro colorimetric method in clinic.Therefore,huge efforts have been paid on the fluorescence imaging that provides a reliable method to detect the real-time and in vivo changes of the level of ALP.In this review,we summarize recent advances in fluorescence imaging of phosphatase,mainly focused on ALP.The imaging probes of phosphatase are mainly classified according to their luminescence mechanisms.In the end,we assessed the challenges and future prospects of phosphatase probes.
基金supported by Grant No.224014 PHOTONICS4LIFE of FP7-ICT-2007-2Project No.1.4.09+3 种基金RF Governmental contracts 11.519.11.2035,14.B37.21.0728 and 14.B37.21.0563FiDiPro,TEKES Program(40111/11),FinlandSCOPES EC,Uzb/Switz/RF,Swiss NSF,IZ74ZO 137423/1RF President's Grant 1177.2012.2"Scientific Schools".
文摘The hollow core photonic crystal waveguide biosensor is designed and described.The biosensor was tested in experiments for artificial sweetener identifcation in drinks.The photonic crystal waveguide biosensor has a high sensitivity to the optical properties of liquids flling up the hollow core.The compactness,good integration ability to different optical systems and compatibility for use in industrial settings make such biosensor very promnising for v arious biomedical applicat ions.
文摘In this work, we suggest a system for chaos-based encryption of electrocardiographic signals. It uses simple electronics organized around a colpitts chaotic oscillator. The system has been designed, implemented and tested. The encrypted signal has been decrypted and compared to the original ECG signal. Experimental results were analysed and proved encouraging.
文摘The system ＂substrate--graphene island on its surface＂ was modeled with using semi-empirical quantum chemistry methods for various substrates. Such system imitates the graphene nucleation and growth when using CVD （chemical vapor deposition） technique. Herewith the carbon atoms can enter the island from both the substrate and the bulk of the CVD reactor. The authors show that for a wide island size range the carbon nanowalls placed perpendicularly as to the substrate is the most favorable configuration. But a transfer to this configuration is only possible providing two conditions are realized： the CVD technique is stimulated by plasma, when a strong electrical field exists near the substrate surface and preliminary decomposition of carbon carrier is realized in the bulk of the CVD-reactor.
文摘Contour is an important pattern descriptor in image processing and particularly in region description, registration and length estimation. In many applications where contour is used, a good segmentation and an efficient smoothing method are needed. In X-ray images, such as mammograms, where object edge is not clearly discernible, estimating the object’s contour may yield substantial shift along the boundary due to noise or segmentation drawbacks. An appropriate smoothing is therefore required to reduce these effects. In this paper, an approach based on local adaptive threshold segmentation to extract contour and a new smoothing approach founded on Fourier descriptors are introduced. The experimental results of extraction obtained from a set of mammograms and compared with the breast regions delineated by radiologists yielded a percent overlap area of 98.7% ± 0.9% with false positive and negative rates of 0.36 ± 0.74 and 0.93 ± 0.44 respectively. The proposed method was tested on a set of images and improved the accuracy, leading to an average error of less than one pixel.
文摘Blindness which is considered as degrading disabling disease is the final stage that occurs when a certain threshold of visual acuity is overlapped. It happens with vision deficiencies that are pathologic states due to many ocular diseases. Among them, diabetic retinopathy is nowadays a chronic disease that attacks most of diabetic patients. Early detection through automatic screening programs reduces considerably expansion of the disease. Exudates are one of the earliest signs. This paper presents an automated method for exudates detection in digital retinal fundus image. The first step consists of image enhancement. It focuses on histogram expansion and median filter. The difference between filtered image and his inverse reduces noise and removes background while preserving features and patterns related to the exudates. The second step refers to blood vessel removal by using morphological operators. In the last step, we compute the result image with an algorithm based on Entropy Maximization Thresholding to obtain two segmented regions (optical disk and exudates) which were highlighted in the second step. Finally, according to size criteria, we eliminate the other regions obtain the regions of interest related to exudates. Evaluations were done with retinal fundus image DIARETDB1 database. DIARETDB1 gathers high-quality medical images which have been verified by experts. It consists of around 89 colour fundus images of which 84 contain at least mild non-proliferative signs of the diabetic retinopathy. This tool provides a unified framework for benchmarking the methods, but also points out clear deficiencies in the current practice in the method development. Comparing to other recent methods available in literature, we found that the proposed algorithm accomplished better result in terms of sensibility (94.27%) and specificity (97.63%).
文摘This paper provides an overview of the main recommendations and approaches of the methodology on parallel computation application development for hybrid structures. This methodology was developed within the master＇s thesis project ＂Optimization of complex tasks＇ computation on hybrid distributed computational structures＂ accomplished by Orekhov during which the main research objective was the determination of＂ patterns of the behavior of scaling efficiency and other parameters which define performance of different algorithms＇ implementations executed on hybrid distributed computational structures. Major outcomes and dependencies obtained within the master＇s thesis project were formed into a methodology which covers the problems of applications based on parallel computations and describes the process of its development in details, offering easy ways of avoiding potentially crucial problems. The paper is backed by the real-life examples such as clustering algorithms instead of artificial benchmarks.
