Pericytes protect rats and mice from sepsis-induced injuries by maintaining vascular reactivity and barrier function:implication of miRNAs and microvesicles

Background Vascular hyporeactivity and leakage are key pathophysiologic features that produce multi-organ damage upon sepsis.We hypothesized that pericytes,a group of pluripotent cells that maintain vascular integrity and tension,are protective against sepsis via regulating vascular reactivity and permeability.Methods We conducted a series of in vivo experiments using wild-type(WT),platelet-derived growth factor receptor-β(PDGFR-β)-Cre+mT/mG transgenic mice and Tie2-Cre+Cx43^(flox/flox)mice to examine the relative contribution of pericytes in sepsis,either induced by cecal ligation and puncture(CLP)or lipopolysaccharide(LPS)challenge.In a separate set of experiments with Sprague-Dawley(SD)rats,pericytes were depleted using CP-673451,a selective PDGFR-βinhibitor,at a dosage of 40 mg/(kg·d)for 7 consecutive days.Cultured pericytes,vascular endothelial cells(VECs)and vascular smooth muscle cells(VSMCs)were used for mechanistic investigations.The effects of pericytes and pericyte-derived microvesicles(PCMVs)and candidate miRNAs on vascular reactivity and barrier function were also examined.Results CLP and LPS induced severe injury/loss of pericytes,vascular hyporeactivity and leakage(P<0.05).Transplantation with exogenous pericytes protected vascular reactivity and barrier function via microvessel colonization(P<0.05).Cx43 knockout in either pericytes or VECs reduced pericyte colonization in microvessels(P<0.05).Additionally,PCMVs transferred miR-145 and miR-132 to VSMCs and VECs,respectively,exerting a protective effect on vascular reactivity and barrier function after sepsis(P<0.05).miR-145 primarily improved the contractile response of VSMCs by activating the sphingosine kinase 2(Sphk2)/sphingosine-1-phosphate receptor(S1PR)1/phosphorylation of myosin light chain 20 pathway,whereas miR-132 effectively improved the barrier function of VECs by activating the Sphk2/S1PR2/zonula occludens-1 and vascular endothelial-cadherin pathways.Conclusions Pericytes are protective against sepsis through regulating vascular reactivity and barrier function.Possible mechanisms include both direct colonization of microvasculature and secretion of PCMVs.

Tuning the reactivity of TiO_(2)layer with uniform distribution of Sub-5 nm Fe_(2)O_(3)particles via in situ voltage-assisted oxidation for robust catalytic reduction

The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.

Wettability,reactivity,and interface structure in Mg/Ni system

The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni substrates.For comparison,the experiments were performed in two variants:(1)using the Capillary Purification(CP)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact Heating(CH)procedure.The high-temperature tests were performed under isothermal conditions(CP:760℃for 30 s;CH:715℃for 300 s)using Ar+5 wt%H_(2) atmosphere.During the sessile drop tests,images of the Mg/Ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate couples.Scanning and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified couples.It was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the Ni substrate(an average contact angleθ<90°in<1 s),followed by fast spreading and good wetting over the Ni substrate(θ_((CP))~20°in 5 s)to form a final contact angle ofθ_(f(CP))~18°.In contrast,a different wetting behavior was observed for the CH procedure,where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test temperature.However,in both cases,the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.

Correction to:Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium

Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same image.Figure 5 was inaccurately referenced and displayed.The correct Fig.5 is copied below:The original article has been updated.

Experimental Study of the Influence of Intrinsic Parameters on the Thermal Reactivity of Sawdust, Polyethylene Terephthalate and Composite

Several works have been based on the study of thermal variations in biomass to derive more valuable products such as fuels capable of replacing oil in the event of a crisis or activated carbon used as an adsorbent material, widely used in industry for the elimination of unwanted materials, both in liquid and gaseous environments. A study of thermal parameters such as: heating speed, retention time, drying temperature, carbonization temperature, particle size, was carried out with the aim of determining the characteristic factors of the carbonization of Polyethylene terephthalate (PET), sawdust (SC) and sawdust/polyethylene terephthalate (CPS) mixture. The results of the immediate analysis revealed a very low level of ash in PET (0.013%) compared to the level of ash in sawdust (2.9%), as well as a high level of fixed carbon (82.960%), which suggests the presence of mineral oxides and a significant carbon matrix unlike PET, which indicates a very significant organic matrix (essentially made up of organic matter) with the absence of mineral oxides. The study of thermal parameters showed the water loss from Sawdust (SC) and the Sawdust/Polyethylene terephthalate (CPS) mixture, an increase with temperature, unlike that of PET whose variation is essentially zero. Without heat treatment, sawdust alone contains approximately 7% water. The optimal drying temperature for this study is 110˚C for a stay of 24 hours. It appears that the largest mass losses for the PET samples are between 87.19% and 96.05%, followed by that of the mixture, between 47.33% and 64.37%. And the lowest are observed, those of sawdust (from 24.02% to 62.6%). However, here we can say that the influence of the mass is not great, given the slight difference between the losses by temperature. The results of the study of the influence of grain size showed that the differences are insignificant, even if we vary the diameter of the grains from simple to triple. To better minimize physical constraints such as the intragranular diffusibility of the volatile matter and the homogeneity of the temperature in the grains, 75 μm particles are found to be optimal for our study. It can be noted when studying the heating rate that the mass loss at the end of the reaction is approximately the same depending on each precursor material. However, it has been demonstrated that the heating rate strongly influences the nature of the reaction products both for volatile materials and for the solid residue as well as on the kinetic parameters of the chemical reaction. Furthermore, the variation in apparent density shows a decrease as a function of the increase in the residence time of the materials in the reactor. As the carbonization time increases, the apparent density decreases. We note, for the lignocellulosic material, that the apparent density stabilizes after 60 minutes.

Synergistic activation of smithsonite with copper-ammonium species for enhancing surface reactivity and xanthate adsorption

Copper ions(Cu^(2+))are usually added to activate the sulfidized surface of zinc oxide minerals to enhance xanthate attachment using sulfidization xanthate flotation technology.The adsorption of Cu^(2+)and xanthate on the sulfidized surface was investigated in various systems,and its effect on the surface hydrophobicity and flotation performance was revealed by multiple analytical methods and experiments.X-ray photoelectron spectroscopy(XPS)and time-of-flight secondary ion mass spectrometry(To F-SIMS)characterization demonstrated that the adsorption of Cu^(2+)on sulfidized smithsonite surfaces increased the active Cu—S content,regardless of treatment in any activation system.The sulfidized surface pretreated with NH_(4)^(+)-Cu^(2+)created favorable conditions for the adsorption of more Cu^(2+),significantly enhancing the smithsonite reactivity.Zeta potential determination,ultraviolet(UV)-visible spectroscopy,Fourier transform-infrared(FT-IR)measurements,and contact angle detection showed that xanthate was chemically adsorbed on the sulfidized surface,and its adsorption capacity in various systems was illustrated from qualitative and quantitative aspects.In comparison to the Na2S–Cu^(2+)and Cu^(2+)–Na2S–Cu^(2+)systems,xanthate exhibited a higher adsorption capacity on sulfidized smithsonite surfaces in NH_(4)^(+)-Cu^(2+)–Na2S–Cu^(2+)system.Hence,activation with Cu^(2+)–NH4+synergistic species prior to sulfidization significantly enhanced the mineral surface hydrophobicity,thereby increasing its flotation recovery.

Morphology,Nanostructure,and Oxidation Reactivity of Particulate Matter Emitted by Diesel Blending with Various Aromatics

This study aims to analyze the influence of the polycyclic aromatic hydrocarbon(PAH)content in diesel on the physical and chemical properties of diesel soot particles.Four diesel fuels with different PAH content were tested on a 11.6 L direct-injection diesel engine.The raw particulate matter(PM)before the after-treatment devices was collected using the thermophoresis sampling system and the filter sampling system.A transmission electron microscope and Raman spectrometer are used to analyze the physical properties of the soot particles,including morphology,primary particle size distribution,and graphitization degree.A Fourier transform infrared spectrometer and thermogravimetric analyzer are used to characterize the surface chemical composition and oxidation reactivity of soot particles,respectively.The results show that as the PAH content in the fuel decreases,the size of the primary soot particles decreases from 29.58 to 26.70 nm.The graphitization degree of soot particles first increases and then decreases,and the relative content of the aliphatic hydrocarbon functional groups of soot particles first decreases and then increases.The T_(10),T_(50),and T_(90) of soot from high-PAH fuel are 505.3,589.3,and 623.5℃,while those from low-PAH fuel are 480.1,557.5,and 599.2℃,respectively.This indicates that exhaust PM generated by the low-PAH fuel has poor oxidation reactivity.However,as the PAH content in fuel is further decreased,the excessively high cetane number may cause uneven mixing and incomplete combustion,leading to enhanced oxidation reactivity.

Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium

To provide a reliable and comprehensive data reference for core geometry design of graphite-moderated and low-enriched uranium fueled molten salt reactors,the influences of geometric parameters on the temperature coefficient of reactivity(TCR)at an assembly level were characterized.A four-factor formula was introduced to explain how different reactivity coefficients behave in terms of the fuel salt volume fraction and assembly size.The results show that the fuel salt temperature coefficient(FSTC)is always negative owing to a more negative fuel salt density coefficient in the over-moderated region or a more negative Doppler coefficient in the under-moderated region.Depending on the fuel salt channel spacing,the graphite moderator temperature coefficient(MTC)can be negative or positive.Furthermore,an assembly with a smaller fuel salt channel spacing is more likely to exhibit a negative MTC.As the fuel salt volume fraction increases,the negative FSTC first weakens and then increases,owing to the fuel salt density effect gradually weakening from negative to positive feedback and then decreasing.Meanwhile,the MTC weakens as the thermal utilization coefficient caused by the graphite temperature effect deteriorates.Thus,the negative TCR first weakens and then strengthens,mainly because of the change in the fuel salt density coefficient.As the assembly size increases,the magnitude of the FSTC decreases monotonously owing to a monotonously weakened fuel salt Doppler coefficient,whereas the MTC changes from gradually weakened negative feedback to gradually enhanced positive feedback.Then,the negative TCR weakens.Therefore,to achieve a proper negative TCR,particularly a negative MTC,an assembly with a smaller fuel salt channel spacing in the under-moderated region is strongly recommended.

Molecular Reactivity and Interface Stability Modification in In-Situ Gel Electrolyte for High Performance Quasi-Solid-State Lithium Metal Batteries

Quasi-solid-state lithium metal battery is a promising candidate for next generation high energy density and high safety power supply.Despite intensive efforts on electrolytes,uncontrolled interfacial reactions on lithium with electrolyte and patchy interfacial contacts still hinder its practical process.Herein,we bring in rationally designed F contained groups into polymer skeleton via in-situ gelation for the first time to establish quasi-solid-state battery.This method achieves a capacity retention of 90%after 1000 cycles at 0.5C with LiFePO_(4)cathodes.The interface constructed by polymer skeleton and reaction with–CF_(3)lead to the predicted solid electrolyte interface species with high stability.Furthermore,we optimize molecular reactivity and interface stability with regulating F contained end groups in the polymer.Comparisons on different structures reveal that high performance solid stable lithium metal batteries rely on chemical modification as well as stable polymer skeleton,which is more critical to construct robust and steady SEI with uniform lithium deposition.New approach with functional groups regulation proposes a more stable cycling process with a capacity retention of 94.2%at 0.5C and 87.6%at 1C after 1000 cycles with LiFePO_(4) cathodes,providing new insights for the practical development of quasi-solid-state lithium metal battery.

Computational Chemistry and Molecular Modeling Techniques for the Study of Micropeptin EI-964: Insights into Its Chemical Reactivity and Potential Pharmaceutical Properties

Micropeptin EI-964 is a cyclic peptide compound isolated from a marine cyanobacterium with potent inhibitory activity against serine proteases, particularly chymotrypsin and trypsin. It has shown promising activity against various cancer cell lines, making it a candidate for drug development. The unique structure and activity of Micropeptin EI-964 make it a promising lead compound for the development of novel serine protease inhibitors and anti-cancer drugs. Computational Chemistry and Molecular Modeling techniques can provide valuable insights into the chemical reactivity and pharmaceutical properties of Micropeptin EI-964, guiding the design and development of new compounds with enhanced bioactivity and improved drug-like properties.

Computational investigation on the molecular structure and chemical reactivity of a traditional Chinese medicine extract MK-1 molecule

MK-1 molecule(C_(16)H_(16)O_(2)),the simplest structure of vitamin K(VK)compound family,is an extract from traditional Chinese medicine Cymbopogon distans(Nees ex Steud.)Wats(Chinese name YunXiangCao),which has attracted a great deal of attention in recent years due to its antiasthmatic,antitussives and expectorant effects.To investigate the molecular structure and chemical reactivity of MK-1 molecule,computational investigations on six conformational minima structures were carried out at the MP2/6-311++G(2d,2p)level of theory.Several local reactivity descriptors including condensed Fukui function,average local ionization energy,and molecular electrostatic potential on each individual atom were determined to predict the intrinsic reactivity of MK-1 molecule.

An Observational Study of the Relationship Between Outcome and Platelet Reactivity in Chinese Patients Undergoing PCI Loading with 600 mg Clopidogrel

Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneous coronary intervention(PCI)and to investigate whether there is a relationship between the number of platelet reactivity units(PRUs)and the characteristics of the patients.Background:Although impaired platelet response to clopidogrel is a strong predictor of unfavorable outcome after PCI,the impact of HPPR to a 600 mg loading dose of clopidogrel in Chinese patients with ACS undergoing PCI is still unknown.Methods:We performed observational research on 134 unselected patients with ACS undergoing urgent or planned PCI with a 600 mg loading dose of clopidogrel.Platelet activation was expressed as the PRU value measured by the VerifyNow assay.Results:Among the 134 patients(mean age 60.62 years[standard deviation 9.13 years],60.4%male),there were 46 patients with HPPR(34.3%)and 88 patients without HPPR(65.7%).At a mean follow-up of 6 months(standard deviation 1 month),the rates of cardiac death,unstable angina,and rehospitalization for target lesion revascularization were higher in the HPPR group(19.6%vs.6.8%,P=0.029).Multivariate analysis identifi ed hemoglobin level and sex as independent predictors of the PRU value(y=456.355−1.736 x 1−31.880 x 2,P<0.05).On receiver operating characteristic curve analysis,PRU values could signifi cantly discriminate between patients with and patients without cardiac death,unstable angina,and rehospitalization for target lesion revascularization(area under the curve 0.758,95%confi dence interval 0.62–0.85,P=0.001,P<0.05).Conclusion:In patients with ACS,HPPR to a 600 mg loading dose of clopidogrel is associated with worse outcomes after PCI.There is some relationship between the PRU value and the hemoglobin level and sex.PRU values can predict the prognosis.

Current status of high on-treatment platelet reactivity in patients with coronary or peripheral arterial disease:Mechanisms,evaluation and clinical implications

Antiplatelet therapy with aspirin or clopidogrel or both is the standard care for patients with proven coronary or peripheral arterial disease,especially those undergoing endovascular revascularization procedures. However,despite the administration of the antiplatelet regiments,some patients still experience recurrent cardiovascular ischemic events. So far,it is well documented by several studies that in vitro response of platelets may be extremely variable. Poor antiplatelet effect of clopidogrel or high on-treatment platelet reactivity(HTPR) is under investigation by numerous recent studies. This review article focuses on methods used for the ex vivo evaluation of HTPR,as well as on the possible underlying mechanisms and the clinical consequences of this entity. Alternative therapeutic options and future directions are also addressed.

Reactivity of ambient volatile organic compounds(VOCs) in summer of 2004 in Beijing

Ambient volatile organic compounds （VOCs） were sampled at six sites in Beijing in the summer of 2004 and analyzed by GCMS. The chemical reactivities of 73 quantified VOCs species were evaluated by OH loss rates （LOH） and ozone formation potentials （OFPs）. Top 15 reactive species, mainly alkenes and aromatics, were identified by these two methods, and accounted for more than 70% of total reactivity of VOCs. In urban areas, isoprene was the most reactive species in term of OH loss rate, contributing 11.4% to the LOH of VOCs. While toluene, accounting for 9.4% of OFPs, appeared to have a long-time role in the photochemical processes. Tongzhou site is obviously influenced by local chemical industry, but the other five sites showed typical urban features influenced mainly by vehicular emissions.

Overproduction of nitric oxide inhibits vascular reactivity in portal hypertensive rats

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Crystal lattice free volume in a study of initiation reactivity of nitramines:Impact sensitivity

More detailed analysis of a mutual relationship of impact sensitivity(detected by sound) and crystal lattice free volume, △V, for the 18 nitramines shows that its course is not unequivocal. For a part of the studied compounds this sensitivity has increased with increase of the AV values, but for fairly big number of nitramines the relationship works in the opposite direction, especially for data of 1,3,5-trinitro-1,3,5-triazinane, 1,3,5,7-tetranitro-1,3,5,7-tetrazocane. and β-and ε-polymorphs of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane. Initiation reactivity of technical ε-polymorph of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane gives the impression by disorderliness in distribution of the actions of forces in its crystal lattice in comparison with its RS(reduced sensitivity) or chemically pure analogue. Limitations of partial shapes of the mentioned relationship by the molecular-structural similarity, and already published information about the decisive factors governing the crystal structure, signalizes a higher influence of the intermolecular interactions in a crystal lattice in comparison with influence of the crystal lattice free volume for initiation of the crystalline EMs.

Crystal lattice free volume in a study of initiation reactivity of nitramines:Friction sensitivity

The relationship between friction sensitivity(FS) and the crystal lattice free space per molecule, △V. of thirteen nitramines is described by a linear equation, divided into a number of the partial relationships with strong limitations by their molecular structure characteristics. Increasing FS due to raising of the △V values is not clearly confirmed. The influence of the △V values on friction sensitivity of nitramines is similar to that of their aza atoms which influence the mutual orientations of nitro groups in neighboring molecules. The dipole-dipole interaction of the oxygen and nitrogen atoms of nitro groups in neighboring nitramine molecules has a major effect on their own FS. In accordance with this interaction, a directly proportional relationship was derived between FS and the intrinsic gas phase molecular volume, V_(int), of the nitramines mentioned, which is divided also into several straight lines according to relatively tight molecular structure similarity. The relationships found again confirm a level of disorder in the distribution of the forces in the crystal lattice of the "common" quality of ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, in comparison with its reduced sensitivity(RS) or chemically pure analogue.

Monomer reactivity ratios for fluoroacrylate and butyl methacrylate in miniemulsion copolymerizations initiated by potassium persulphate

Miniemulsion copolymerization of butyl mathacrylate （BMA） with fluoroacrylate （HFMA, TFMA） was carried out at 70 ℃ by employing potassium persulphate （KPS） as initiator. Copolymer compositions at low conversion levels were determined by ^1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos （K-T） methods, which yields the apparent reactivity ratios, rBMA = 0.74, rHFMA = 0.87 and rBMA = 0.73, rTFMA = 0.75, respectively, and Q- and e-values of HFMA and TFMA were calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.

Impact of photoneutrons on reactivity measurements for TMSR-SF1

The solid-fueled thorium molten salt reactor(TMSR-SF1) is a 10 MW_(th) test reactor design to be deployed in 5-10 years by the TMSR group.Its design combines coated particle fuel and molten FLiBe coolant for great intrinsic safety features and economic advantages.Due to a large amount of beryllium in the coolant salt,photoneutrons are produced by(y,n) reaction,hence the increasing fraction of effective delayed neutrons in the core by the photoneutrons originating from the long-lived fission products.Some of the delayed photoneutron groups are of long lifetime,so a direct effect is resulted in the transient process and reactivity measurement.To study the impact of photoneutrons for TMSR-SF1,the effective photoneutron fraction is estimated using k-ratio method and performed by the Monte Carlo code(MCNP5) with ENDF/B-Ⅶ cross sections.Based on the coupled neutronphoton point kinetics equations,influence of the photoneutrons is analyzed.The results show that the impact of photoneutrons is not negligible in reactivity measurement.Without considering photoneutrons in on-line reactivity measurement based on inverse point kinetics can result in overestimation of the positive reactivity and underestimation of the negative reactivity.The photoneutrons also lead to more waiting time for the doubling time measurement.Since the photoneutron precursors take extremely long time to achieve equilibrium,a "steady" power operation may not directly imply a "real" criticality.

MONOMER REACTIVITY RATIO AND THERMAL PERFORMANCE OFα-METHYL STYRENE AND GLYCIDYL METHACRYLATE COPOLYMERS

Synthesis and characterization of the copolymers （PAG） of α-methyl styrene （AMS） and glycidyl methacrylate （GMA） are presented. The copolymers of PAG were characterized by gel permeation chromatography （GPC）, Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （^1H-NMR） and thermogravimetery （TG）. Based on the copolymer compositions determined by ^1H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ± 0.012 and 0.883 ± 0.046 respectively by Kelen-Tudos method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions.