Undesired ice accumulation on infrastructure and transportation systems leads to catastrophic events and significant economic losses.Although various anti-icing surfaces with photothermal effects can initially prevent...Undesired ice accumulation on infrastructure and transportation systems leads to catastrophic events and significant economic losses.Although various anti-icing surfaces with photothermal effects can initially prevent icing,any thawy droplets remaining on the horizontal surface can quickly re-freezing once the light diminishes.To address these challenges,we have developed a self-draining slippery surface(SDSS)that enables the thawy droplets to self-remove on the horizontal surface,thereby facilitating real-time anti-icing with the aid of sunlight(100 m W cm^(-2)).This is achieved by sandwiching a thin pyroelectric layer between slippery surface and photothermal film.Due to the synergy between the photothermal and pyroelectric layers,the SDSS not only maintains a high surface temperature of 19.8±2.2℃at the low temperature(-20.0±1.0℃),but also generates amount of charge through thermoelectric coupling.Thus,as cold droplets dropped on the SDSS,electrostatic force pushes the droplets off the charged surface because of the charge transfer mechanism.Even if the surface freezes overnight,the ice can melt and drain off the SDSS within 10 min of exposure to sunlight at-20.0±1.0℃,leaving a clean surface.This work provides a new perspective on the anti-icing system in the real-world environments.展开更多
A long-term blood feeder, like the <i><span>Hyalomma</span></i><span> </span><i><span>dromedarii</span></i><span> tick, requires extended con...A long-term blood feeder, like the <i><span>Hyalomma</span></i><span> </span><i><span>dromedarii</span></i><span> tick, requires extended control over all hemostatic defense mechanisms generated by the host during feeding, including blood coagulation. To overcome this, ticks have evolved numerous molecules that target proteases in the blood coagulation cascade. New insights into the role of clotting factors in the development and progression of cancer have identified anticoagulant treatment as a potential therapeutic approach. In this context, the present work assessed the anticoagulation activities of crude and fractionated salivary gland extract (SGE) prepared from semi-fed </span><i><span>H</span></i><span>. </span><i><span>dromedarii</span></i><span> females. Additionally, the antitumor effects of the potent anti-thrombin fractions were determined against colon cancer (Caco-2) and normal skin (HFB4) cells. Crude SGE significantly prolonged clotting time in prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT) assays and inhibited thrombin in FII-activity assay. Using anion-exchange chromatography, the fractions that strongly inhibited thrombin (3.A4 and 3.A5) were eluted. Both fractions prolonged the aPTT and TT clotting times and reduced the activity of FII significantly. The protein profiles of both fractions indicated the presence of a single polypeptide band of about 99 kDa. Regarding anti-cancer potential of the tested fractions, Caco-2 cells showed reduced viability with obvious morphological changes, induced apoptosis and a reduced level of vascular endothelial </span><span>growth factor (VEGF). G2/M cell cycle arrest was observed only in 3.A5-treated</span><span> cells. No cytotoxic effects were observed in HFB4 cells. These results demonstrated the potential of tick-derived anticoagulants, specifically thrombin inhibitors, as effective tools in colorectal cancer treatment. Further purification of the effector molecule(s) is required to fully characterize their structures and mechanisms of action.</span>展开更多
As an efficient passive anti-icing method,the superhydrophobic surface can reduce icing process on metals in low temperatures.However,the usual organic low-surface-energy decorations are often prone to age especially ...As an efficient passive anti-icing method,the superhydrophobic surface can reduce icing process on metals in low temperatures.However,the usual organic low-surface-energy decorations are often prone to age especially in harsh environments,leading to a decrease or complete failure of the anti-icing performance.Here,we adopt a fabrication method of femtosecond laser element-doping microstructuring to achieve inor-ganic superhydrophobic aluminum alloys surfaces through simultaneously modifying the surface profile and compositions of aluminum alloys.The obtained bionic anthill tribe structure with the low thermal conductiv-ity,exhibits the superior delayed freezing time(803.3 s)and the low ice adhesion(16μN)in comparison to the fluorosilane modified and bare Al surfaces.Moreover,such an inherently superhydrophobic metal sur-face also shows the exceptional environmental durability in anti-icing performance,which confirms the ef-fectiveness of our superhydrophobic surface without the need for organic coatings.展开更多
In low-temperature environments,the condensation and icing phenomena of water molecules on material sur-faces may adversely affect the functionality and durability of various products,so it is critical to improve the ...In low-temperature environments,the condensation and icing phenomena of water molecules on material sur-faces may adversely affect the functionality and durability of various products,so it is critical to improve the antiicing properties of material surfaces.In this study,the anti-icing mechanism of superhydrophobic coatings was analyzed based on the surface wettability theory,and SiO_(2)/PDMS/EP superhydrophobic coating was fabricated by the spraying method.The surface wettability,surface micro-morphology,and surface chemical composition of the coating was characterized,and the stability of the coating as well as the anti-icing properties were investi-gated.The results show that the SiO_(2)/PDMS/EP superhydrophobic coating sprayed on the Al-based surface has a contact angle of 163.3° and a sliding angle of 4°,and the coating maintains excellent superhydrophobicity at a low temperature of-15°.This coating can significantly delay the freezing time and temperature of droplets on its surface,reduce the shear force and natural deicing time required to remove surface ice,and exhibit excellent anti-icing performance.The excellent anti-icing durability of the coating was demonstrated by the icing-deicing cycle experiment.Subsequently,the anti-frosting performance was further investigated,and the results showed that it effectively slowed down the speed of frost formation.Therefore,the superhydrophobic coating fabricated in this study is suitable for a wide range of working conditions and has potential practicality.It also provides experimental guidance for the application of anti-icing coatings on Al surfaces.展开更多
Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical applicatio...Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical application in long-term and complex scenarios.Herein,inspired by the unique structure of the barnacle,we design multifunctional poly(DMAPA-co-PHEA)hydrogels(CP hydrogels)by employing multiple physical crosslinks in the presence of Ag nanoparticles and NaCl additives.Owing to the synergistic effect of cation-πinteractions,hydrophobic interactions,and ionic bonds,the CP hydrogels exhibit high stretchability(strain up to 1430%),strong adhesion(22.8 kPa),satisfactory antibacterial activity,stable anti-icing ability(<20 kPa after 20 icing-deicing cycles),and high electrical conductivity(18.5 mS/cm).Additionally,the CP hydrogels show fast and sensitive responsiveness and cycling stability and can attach directly to human skin to accurately detect both human motions and tiny physiological signals as a flexible wearable sensor.Collectively,this work significantly contributes a straightforward and efficient design strategy for the development of multifunctional hydrogels,broadening their application scenarios.展开更多
Thrombin blockers have been shown to be effective for various pathological conditions,but their use is limited due to the potential for serious bleeding adverse effects.This study introduced a novel bioactive peptide(...Thrombin blockers have been shown to be effective for various pathological conditions,but their use is limited due to the potential for serious bleeding adverse effects.This study introduced a novel bioactive peptide(P-2-CG) from oyster,that mitigated thrombin-mediated barrier dysfunction and prothrombotic phenotypes in human pulmonary microvascular endothelial cells(HPMECs).P-2-CG significantly attenuated the increase in endothelial monolayer permeability induced by thrombin through the possible attenuation of RhoA activation and it promoted barrier recovery by enhancing endothelial cell adhesion.Additionally,P-2-CG was found to decrease the pro-thrombotic phenotype induced by thrombin in HPMEC by reducing the extrinsic trigger tissue factor mRNA expression,which resulted in prolonged plasma clotting time,decreased Factor Xa activation,and reduced thrombin generation.Moreover,P-2-CG inhibited thrombosis efficiently by blocking intercellular adhesion molecule 1 and vascular cell adhesion protein 1 expression via tyrosine phosphorylation of nuclear factor-κB p65.P-2-CG inhibits thrombin mediated inflammation and provides a potential therapeutic option for treating endothelial dysfunction and thrombosis.展开更多
In this study,femtosecond pulsed laser processing was applied to the magnesium alloy,followed by in situ growth of Mg-Al layered double hydroxides(LDHs),and finally modification with low surface energy materials to pr...In this study,femtosecond pulsed laser processing was applied to the magnesium alloy,followed by in situ growth of Mg-Al layered double hydroxides(LDHs),and finally modification with low surface energy materials to prepare a biomimetic of centipede-like superhydrophobic composite coating.The resulting biomimetic coating features a dual-scale structure,comprising a micron-scale laser-etched array and nano-scale LDH sheets,which together create a complex hierarchical architecture.The multistage bionic superhydrophobic coating exhibits exceptional corrosion resistance,with a reduction in corrosion current density by approximately five orders of magnitude compared to the bare magnesium alloy substrate.This remarkable corrosion resistance is attributed to the synergistic effects of the superhydrophobicity with a contact angle(CA)of 154.60°,the densification of the surface LDH nanosheets,and the NO_(3)^(-) exchange capacity.Additionally,compared to untreated AZ91D alloy,the biomimetic coating prolongs ice formation time by 250% at-40℃ and withstands multiple cycles of sandpaper abrasion and repeated tape peeling tests.Furthermore,it demonstrates excellent self-cleaning and anti-fouling properties,as confirmed by dye immersion and dust contamination tests.The construction of the multi-level bionic structured coating not only holds significant practical potential for metal protection but also provides valuable insights into the application of formed LDH materials in functional bionic coating engineering.展开更多
Icing detection is critically important for preventing safety accidents and economic losses,especially concerning ice formation from invalidated anti-icing fluids(water and ethylene glycol)under extreme conditions.Tra...Icing detection is critically important for preventing safety accidents and economic losses,especially concerning ice formation from invalidated anti-icing fluids(water and ethylene glycol)under extreme conditions.Traditional technologies like ultrasonics and capacitor-antenna face challenges with limited detection areas,lower accuracy,and susceptibility to electromagnetic interference.Here,we introduce a novel viscosity-ultrasensitive fluorescent probe 40,4‴-(2,2-diphenyle-thene-1,1-diyl)bis-(3,5-dicarboxylate)(TPE-2B4C)based on AIEgens for moni-toring ice formation of anti-icing fluids in low-temperature environments.TPE-2B4C,consisting of four sodium carboxylate groups and multiple freely rotating benzene rings,demonstrates outstanding solubility in anti-icing fluids and exhibits no fluorescent background signal even at low temperatures(<−20°C).Upon freezing,TPE-2B4C relocates from the water phase to higher viscosity ethylene glycol,causing restriction of benzene rings and a significantly increased green fluorescence signal.TPE-2B4C can successfully determine whether the anti-icing fluids are icing from−5 to−20°C with a high contrast ratio.Due to its simple setup,fast operation,and broad applicability,our new method is anticipated to be employed for rapid,real-time,and large-scale icing detection.展开更多
Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubat...Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products （CB-1, CB-2） from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.展开更多
Objective To evaluate the role of thrombin-activated microglia in the neurodegeneration of nigral dopaminergic neurons in the rat substantia nigra （SN） in vivo. Methods After stereotaxic thrombin injection into unil...Objective To evaluate the role of thrombin-activated microglia in the neurodegeneration of nigral dopaminergic neurons in the rat substantia nigra （SN） in vivo. Methods After stereotaxic thrombin injection into unilateral SN of rats, immunostaining, reverse transcription polymerase chain reaction （RT-PCR） and biochemical methods were used to observe tyrosine hydroxylase （TH） irnmunoreactive positive cells, microglia activation, nitric oxide （NO） amount and inducible nitricoxide synthase （iNOS） expression. Results （1） Selective damage to dopaminergic neurons was produced after thrombin injection, which was evidenced by loss of TH imrnunostaining in time-dependent manner; （2） Strong microglial activation was observed in the SN; （3） RT-PCR demonstrated the early and transient expression of neurotoxic factors iNOS mRNA in the SN. Immunofluorescence results found that thrombin induced expression of iNOS in microglia. The NO production in the thrombininjected rats was significantly higher than that of controls （P 〈 0.05）. Conclusion Thrombin intranigral injection can injure the dopaminergic neurons in the SN. Thrombin-induced microglia activation precedes dopaminergic neuron degeneration, which suggest that activation of microglia and release of NO may play important roles in dopaminergic neuronal death in the SN.展开更多
基金supported by the National Natural Science Foundation of China(52273101,51922018,and 21875011)the Fundamental Research Funds for the Central Universities(KG21015201 and KG21020801)China Postdoctoral Science Foundation(2025M77422)。
文摘Undesired ice accumulation on infrastructure and transportation systems leads to catastrophic events and significant economic losses.Although various anti-icing surfaces with photothermal effects can initially prevent icing,any thawy droplets remaining on the horizontal surface can quickly re-freezing once the light diminishes.To address these challenges,we have developed a self-draining slippery surface(SDSS)that enables the thawy droplets to self-remove on the horizontal surface,thereby facilitating real-time anti-icing with the aid of sunlight(100 m W cm^(-2)).This is achieved by sandwiching a thin pyroelectric layer between slippery surface and photothermal film.Due to the synergy between the photothermal and pyroelectric layers,the SDSS not only maintains a high surface temperature of 19.8±2.2℃at the low temperature(-20.0±1.0℃),but also generates amount of charge through thermoelectric coupling.Thus,as cold droplets dropped on the SDSS,electrostatic force pushes the droplets off the charged surface because of the charge transfer mechanism.Even if the surface freezes overnight,the ice can melt and drain off the SDSS within 10 min of exposure to sunlight at-20.0±1.0℃,leaving a clean surface.This work provides a new perspective on the anti-icing system in the real-world environments.
文摘A long-term blood feeder, like the <i><span>Hyalomma</span></i><span> </span><i><span>dromedarii</span></i><span> tick, requires extended control over all hemostatic defense mechanisms generated by the host during feeding, including blood coagulation. To overcome this, ticks have evolved numerous molecules that target proteases in the blood coagulation cascade. New insights into the role of clotting factors in the development and progression of cancer have identified anticoagulant treatment as a potential therapeutic approach. In this context, the present work assessed the anticoagulation activities of crude and fractionated salivary gland extract (SGE) prepared from semi-fed </span><i><span>H</span></i><span>. </span><i><span>dromedarii</span></i><span> females. Additionally, the antitumor effects of the potent anti-thrombin fractions were determined against colon cancer (Caco-2) and normal skin (HFB4) cells. Crude SGE significantly prolonged clotting time in prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT) assays and inhibited thrombin in FII-activity assay. Using anion-exchange chromatography, the fractions that strongly inhibited thrombin (3.A4 and 3.A5) were eluted. Both fractions prolonged the aPTT and TT clotting times and reduced the activity of FII significantly. The protein profiles of both fractions indicated the presence of a single polypeptide band of about 99 kDa. Regarding anti-cancer potential of the tested fractions, Caco-2 cells showed reduced viability with obvious morphological changes, induced apoptosis and a reduced level of vascular endothelial </span><span>growth factor (VEGF). G2/M cell cycle arrest was observed only in 3.A5-treated</span><span> cells. No cytotoxic effects were observed in HFB4 cells. These results demonstrated the potential of tick-derived anticoagulants, specifically thrombin inhibitors, as effective tools in colorectal cancer treatment. Further purification of the effector molecule(s) is required to fully characterize their structures and mechanisms of action.</span>
文摘As an efficient passive anti-icing method,the superhydrophobic surface can reduce icing process on metals in low temperatures.However,the usual organic low-surface-energy decorations are often prone to age especially in harsh environments,leading to a decrease or complete failure of the anti-icing performance.Here,we adopt a fabrication method of femtosecond laser element-doping microstructuring to achieve inor-ganic superhydrophobic aluminum alloys surfaces through simultaneously modifying the surface profile and compositions of aluminum alloys.The obtained bionic anthill tribe structure with the low thermal conductiv-ity,exhibits the superior delayed freezing time(803.3 s)and the low ice adhesion(16μN)in comparison to the fluorosilane modified and bare Al surfaces.Moreover,such an inherently superhydrophobic metal sur-face also shows the exceptional environmental durability in anti-icing performance,which confirms the ef-fectiveness of our superhydrophobic surface without the need for organic coatings.
基金supported by the National Key R&D Program of China(2022YFB3403304)the National Natural Science Foundation of China(NSFC,Grant No.52275420,U23A20632)the Natural Science Foundation of Hunan Province[Grant No.2022JJ30136].
文摘In low-temperature environments,the condensation and icing phenomena of water molecules on material sur-faces may adversely affect the functionality and durability of various products,so it is critical to improve the antiicing properties of material surfaces.In this study,the anti-icing mechanism of superhydrophobic coatings was analyzed based on the surface wettability theory,and SiO_(2)/PDMS/EP superhydrophobic coating was fabricated by the spraying method.The surface wettability,surface micro-morphology,and surface chemical composition of the coating was characterized,and the stability of the coating as well as the anti-icing properties were investi-gated.The results show that the SiO_(2)/PDMS/EP superhydrophobic coating sprayed on the Al-based surface has a contact angle of 163.3° and a sliding angle of 4°,and the coating maintains excellent superhydrophobicity at a low temperature of-15°.This coating can significantly delay the freezing time and temperature of droplets on its surface,reduce the shear force and natural deicing time required to remove surface ice,and exhibit excellent anti-icing performance.The excellent anti-icing durability of the coating was demonstrated by the icing-deicing cycle experiment.Subsequently,the anti-frosting performance was further investigated,and the results showed that it effectively slowed down the speed of frost formation.Therefore,the superhydrophobic coating fabricated in this study is suitable for a wide range of working conditions and has potential practicality.It also provides experimental guidance for the application of anti-icing coatings on Al surfaces.
基金financial support from the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012218)Macao Science and Technology Development Fund(Nos.FDCT 0009/2020/AMJ,0027/2023/RIB1)+1 种基金National Natural Science Foundation of China(No.32301104)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.23ptpy165).
文摘Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical application in long-term and complex scenarios.Herein,inspired by the unique structure of the barnacle,we design multifunctional poly(DMAPA-co-PHEA)hydrogels(CP hydrogels)by employing multiple physical crosslinks in the presence of Ag nanoparticles and NaCl additives.Owing to the synergistic effect of cation-πinteractions,hydrophobic interactions,and ionic bonds,the CP hydrogels exhibit high stretchability(strain up to 1430%),strong adhesion(22.8 kPa),satisfactory antibacterial activity,stable anti-icing ability(<20 kPa after 20 icing-deicing cycles),and high electrical conductivity(18.5 mS/cm).Additionally,the CP hydrogels show fast and sensitive responsiveness and cycling stability and can attach directly to human skin to accurately detect both human motions and tiny physiological signals as a flexible wearable sensor.Collectively,this work significantly contributes a straightforward and efficient design strategy for the development of multifunctional hydrogels,broadening their application scenarios.
基金supported by The National Natural Science Foundation of China (32130085 and 32202021)。
文摘Thrombin blockers have been shown to be effective for various pathological conditions,but their use is limited due to the potential for serious bleeding adverse effects.This study introduced a novel bioactive peptide(P-2-CG) from oyster,that mitigated thrombin-mediated barrier dysfunction and prothrombotic phenotypes in human pulmonary microvascular endothelial cells(HPMECs).P-2-CG significantly attenuated the increase in endothelial monolayer permeability induced by thrombin through the possible attenuation of RhoA activation and it promoted barrier recovery by enhancing endothelial cell adhesion.Additionally,P-2-CG was found to decrease the pro-thrombotic phenotype induced by thrombin in HPMEC by reducing the extrinsic trigger tissue factor mRNA expression,which resulted in prolonged plasma clotting time,decreased Factor Xa activation,and reduced thrombin generation.Moreover,P-2-CG inhibited thrombosis efficiently by blocking intercellular adhesion molecule 1 and vascular cell adhesion protein 1 expression via tyrosine phosphorylation of nuclear factor-κB p65.P-2-CG inhibits thrombin mediated inflammation and provides a potential therapeutic option for treating endothelial dysfunction and thrombosis.
基金supported by the National Natural Science Foundation of China(No.52331004,U2106216)the Natural Science Foundation of Shandong Province(No.ZR2022ZD12)+2 种基金the Key R&D Program of Shandong Province,China(2023ZLGX05,2023CXGC010406)Key Program of Natural Science Foundation of Shandong Province of China(No.ZR2022ZD12,ZR2024ZD14)the Taishan Scholarship of Climbing Plan(No.tspd20230603)。
文摘In this study,femtosecond pulsed laser processing was applied to the magnesium alloy,followed by in situ growth of Mg-Al layered double hydroxides(LDHs),and finally modification with low surface energy materials to prepare a biomimetic of centipede-like superhydrophobic composite coating.The resulting biomimetic coating features a dual-scale structure,comprising a micron-scale laser-etched array and nano-scale LDH sheets,which together create a complex hierarchical architecture.The multistage bionic superhydrophobic coating exhibits exceptional corrosion resistance,with a reduction in corrosion current density by approximately five orders of magnitude compared to the bare magnesium alloy substrate.This remarkable corrosion resistance is attributed to the synergistic effects of the superhydrophobicity with a contact angle(CA)of 154.60°,the densification of the surface LDH nanosheets,and the NO_(3)^(-) exchange capacity.Additionally,compared to untreated AZ91D alloy,the biomimetic coating prolongs ice formation time by 250% at-40℃ and withstands multiple cycles of sandpaper abrasion and repeated tape peeling tests.Furthermore,it demonstrates excellent self-cleaning and anti-fouling properties,as confirmed by dye immersion and dust contamination tests.The construction of the multi-level bionic structured coating not only holds significant practical potential for metal protection but also provides valuable insights into the application of formed LDH materials in functional bionic coating engineering.
基金support from the National Natural Science Foundation of China(9235630033,22105069)Shanghai Pujiang Program(20PJ1402900)+2 种基金Shanghai Natural Science Foundation(21ZR1418400)Innovation Program of Shanghai Municipal Education Commission(2023FGS01)Natural Science Foundation of Jiangsu Province(BK20231225).
文摘Icing detection is critically important for preventing safety accidents and economic losses,especially concerning ice formation from invalidated anti-icing fluids(water and ethylene glycol)under extreme conditions.Traditional technologies like ultrasonics and capacitor-antenna face challenges with limited detection areas,lower accuracy,and susceptibility to electromagnetic interference.Here,we introduce a novel viscosity-ultrasensitive fluorescent probe 40,4‴-(2,2-diphenyle-thene-1,1-diyl)bis-(3,5-dicarboxylate)(TPE-2B4C)based on AIEgens for moni-toring ice formation of anti-icing fluids in low-temperature environments.TPE-2B4C,consisting of four sodium carboxylate groups and multiple freely rotating benzene rings,demonstrates outstanding solubility in anti-icing fluids and exhibits no fluorescent background signal even at low temperatures(<−20°C).Upon freezing,TPE-2B4C relocates from the water phase to higher viscosity ethylene glycol,causing restriction of benzene rings and a significantly increased green fluorescence signal.TPE-2B4C can successfully determine whether the anti-icing fluids are icing from−5 to−20°C with a high contrast ratio.Due to its simple setup,fast operation,and broad applicability,our new method is anticipated to be employed for rapid,real-time,and large-scale icing detection.
文摘Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products （CB-1, CB-2） from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.
文摘Objective To evaluate the role of thrombin-activated microglia in the neurodegeneration of nigral dopaminergic neurons in the rat substantia nigra （SN） in vivo. Methods After stereotaxic thrombin injection into unilateral SN of rats, immunostaining, reverse transcription polymerase chain reaction （RT-PCR） and biochemical methods were used to observe tyrosine hydroxylase （TH） irnmunoreactive positive cells, microglia activation, nitric oxide （NO） amount and inducible nitricoxide synthase （iNOS） expression. Results （1） Selective damage to dopaminergic neurons was produced after thrombin injection, which was evidenced by loss of TH imrnunostaining in time-dependent manner; （2） Strong microglial activation was observed in the SN; （3） RT-PCR demonstrated the early and transient expression of neurotoxic factors iNOS mRNA in the SN. Immunofluorescence results found that thrombin induced expression of iNOS in microglia. The NO production in the thrombininjected rats was significantly higher than that of controls （P 〈 0.05）. Conclusion Thrombin intranigral injection can injure the dopaminergic neurons in the SN. Thrombin-induced microglia activation precedes dopaminergic neuron degeneration, which suggest that activation of microglia and release of NO may play important roles in dopaminergic neuronal death in the SN.
