The effect of reactive plasticizer on viscoelastic and mechanical properties of solid rocket propellants based on different types of HTPB resin

Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitation.To address this issue,conventional plasticizer,dioctyl adipate(DOA),is replaced by reactive one,castor oil(CO).In addition,three different types of HTPB were used to obtain propellants with designed viscoelastic and mechanical properties.The CO increased propellants viscosity,without a significant impact on the propellant processability,regardless to the type of prepolymer.Conversely,mechanical properties were different depending on the type of resin,which were further analyzed by gel permeation chromatography(GPC).Addition of CO formed a denser polymer network and shifted T_(g) to higher values,compared to the compositions with DOA.The tensile strength of CO-containing propellants was lower at +20℃ and +50℃ compared to the reference compositions,while the strain at maximum load and strain at break were significantly increased with pronounced plastic deformation,especially for samples at -30℃.The inclusion of CO in the propellants composition gives more room for adjusting a wide range of mechanical properties.

Research Progress of Environment Friendly Plasticizers for Cellulose Acetate Processing

Cellulose acetate(CA)is an important cellulose derivative that can undergo thermoplas-tic processing.Plasticizers can form stable hydrogen bonds with CA molecular chains,reducing intermolecular and intramolecular interactions,and play an important role in the melting processing of CA.In recent years,environmentally friendly plasticizers that are natural,non-toxic,odorless,low dissolution,and low migration have received increas-ing attention in plastic processing.This article reviews the research progress of environ-mentally friendly plasticizers such as natural plasticizers,ionic liquid plasticizers,citrate plasticizers,and polyethylene glycol plasticizers in the processing of cellulose acetate,and looks forward to the application prospects of environmentally friendly plasticizers.

Understanding the alkyl effect of geminal dinitropropyl ester energetic plasticizers on hydroxyl terminated polybutadiene(HTPB):Simultaneous tuning on low temperature behavior and processability

Geminal dinitropropyl ester plasticizers(DNPEPs) possess excellent energetic performances which provide good potentials as insensitive plasticizer. In this study, we design and synthesize DNPEPs with different alkane chain parts, and systematically investigate their structure-property relationships.Results show that DNPEPs have impact sensitivities all higher than 25.2 J, thermal decomposition temperatures all higher than 254 ℃, and glass transition temperatures(T_(g)) lower than-90 ℃.Furthermore, the effects of DNPEPs as plasticizer are studied on hydroxyl terminated polybutadiene(HTPB) in detail, including the viscosity, glass transition temperatures and others. It is noteworthy that 2,2-dinitropropyl nonanoate(DNPNc) among these DNPEPs exhibits the most expected simultaneous tuning effects on both viscosity and T_(g) of HTPB systems, providing favorable potentials to replace the conventional plastizers as dioctyl sebacate(DOS) in the HTPB based propellants and explosives.

Lymphatic plastic bronchitis and primary chylothorax: A study based on computed tomography lymphangiography

BACKGROUND This study presents an evaluation of the computed tomography lymphangio-graphy(CTL)features of lymphatic plastic bronchitis(PB)and primary chylotho-rax to improve the diagnostic accuracy for these two diseases.AIM To improve the diagnosis of lymphatic PB or primary chylothorax,a retrospective analysis of the clinical features and CTL characteristics of 71 patients diagnosed with lymphatic PB or primary chylothorax was performed.METHODS The clinical and CTL data of 71 patients(20 with lymphatic PB,41 with primary chylothorax,and 10 with lymphatic PB with primary chylothorax)were collected retrospectively.CTL was performed in all patients.The clinical manifestations,CTL findings,and conventional chest CT findings of the three groups of patients were compared.The chi-square test or Fisher's exact test was used to compare the differences among the three groups.A difference was considered to be statistically significant when P<0.05.RESULTS(1)The percentages of abnormal contrast medium deposits on CTL in the three groups were as follows:Thoracic duct outlet in 14(70.0%),33(80.5%)and 8(80.0%)patients;peritracheal region in 18(90.0%),15(36.6%)and 8(80.0%)patients;pleura in 6(30.0%),33(80.5%)and 9(90.0%)patients;pericardium in 6(30.0%),6(14.6%)and 4(40.0%)patients;and hilum in 16(80.0%),11(26.8%)and 7(70.0%)patients;and(2)the abnormalities on conven-tional chest CT in the three groups were as follows:Ground-glass opacity in 19(95.0%),18(43.9%)and 8(80.0%)patients;atelectasis in 4(20.0%),26(63.4%)and 7(70.0%)patients;interlobular septal thickening in 12(60.0%),11(26.8%)and 3(30.0%)patients;bronchovascular bundle thickening in 14(70.0%),6(14.6%)and 4(40.0%)patients;localized mediastinal changes in 14(70.0%),14(34.1%),and 7(70.0%)patients;diffuse mediastinal changes in 6(30.0%),5(12.2%),and 3(30.0%)patients;cystic lesions in the axilla in 2(10.0%),6(14.6%),and 2(20.0%)patients;and cystic lesions in the chest wall in 0(0%),2(4.9%),and 2(4.9%)patients.CONCLUSION CTL is well suited to clarify the characteristics of lymphatic PB and primary chylothorax.This method is an excellent tool for diagnosing these two diseases.

Neural stem cells promote neuroplasticity: a promising therapeutic strategy for the treatment of Alzheimer’s disease

Recent studies have demonstrated that neuroplasticity,such as synaptic plasticity and neurogenesis,exists throughout the normal lifespan but declines with age and is significantly impaired in individuals with Alzheimer’s disease.Hence,promoting neuroplasticity may represent an effective strategy with which Alzheimer’s disease can be alleviated.Due to their significant ability to self-renew,differentiate,and migrate,neural stem cells play an essential role in reversing synaptic and neuronal damage,reducing the pathology of Alzheimer’s disease,including amyloid-β,tau protein,and neuroinflammation,and secreting neurotrophic factors and growth factors that are related to plasticity.These events can promote synaptic plasticity and neurogenesis to repair the microenvironment of the mammalian brain.Consequently,neural stem cells are considered to represent a potential regenerative therapy with which to improve Alzheimer’s disease and other neurodegenerative diseases.In this review,we discuss how neural stem cells regulate neuroplasticity and optimize their effects to enhance their potential for treating Alzheimer’s disease in the clinic.

Phosphorus Containing Rubber Seed oil as a Flame Retardant Plasticizer for Polyvinyl Chloride

The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands.In this study,flame-retardant rubber seed oil-based plasticize(FRP)was prepared via epoxidation reaction and ring opening addition reactions,which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer.When DOP was replaced with FRP,the torque of PVC blends increased from 11.4 to 18.4 N⋅m,the LOI value increased from 24.3%for PVC-FRP-0%to 33.1%for PVC-FRP-20.The THR value diminished from 39 MJ/m^(2)(pertaining to PVC-FRC-0)to 22 MJ/m^(2)Tg increased from 23°C to 47°C,the weight loss of plasticized PVC blends significantly reduced from 22.6%to 2.8%in leaching tests.The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.

3'-Deoxyadenosin alleviates methamphetamine-induced aberrant synaptic plasticity and seeking behavior by inhibiting the NLRP3 inflammasome

Methamphetamine addiction is a brain disorder characterized by persistent drug-seeking behavior, which has been linked with aberrant synaptic plasticity. An increasing body of evidence suggests that aberrant synaptic plasticity is associated with the activation of the NOD-like receptor family pyrin domain containing-3(NLRP3) inflammasome. 3′-Deoxyadenosin, an active component of the Chinese fungus Cordyceps militaris, has strong anti-inflammatory effects. However, whether 3′-deoxyadenosin attenuates methamphetamine-induced aberrant synaptic plasticity via an NLRP3-mediated inflammatory mechanism remains unclear. We first observed that 3′-deoxyadenosin attenuated conditioned place preference scores in methamphetamine-treated mice and decreased the expression of c-fos in hippocampal neurons. Furthermore, we found that 3′-deoxyadenosin reduced the aberrant potentiation of glutamatergic transmission and restored the methamphetamine-induced impairment of synaptic plasticity. We also found that 3′-deoxyadenosin decreased the expression of NLRP3 and neuronal injury. Importantly, a direct NLRP3 deficiency reduced methamphetamine-induced seeking behavior, attenuated the impaired synaptic plasticity, and prevented neuronal damage. Finally, NLRP3 activation reversed the effect of 3′-deoxyadenosin on behavior and synaptic plasticity, suggesting that the anti-neuroinflammatory mechanism of 3′-deoxyadenosin on aberrant synaptic plasticity reduces methamphetamine-induced seeking behavior. Taken together, 3′-deoxyadenosin alleviates methamphetamine-induced aberrant synaptic plasticity and seeking behavior by inhibiting the NLRP3 inflammasome.

Plasticizing Effect of Camellia oleifera Seed-Oil-Based Plasticizer on PVC Material Modification

In this study,as the plasticizer,Camellia oleifera seed-oil-based cyclohexyl ester(COSOCE)was prepared by the reaction of cyclohexene oxide and refined C.oleifera seed oil(RCOSO)obtained by acidification hydrolysis after saponification.In addition,the structure of the target product was confirmed by Fourier transform infrared(FTIR)spectroscopy,nuclear magnetic resonance(NMR)spectroscopy,and Raman spectroscopy.COSOCE was used as plasticizer-modified polyvinyl chloride(PVC)membranes.The structure of the COSOCE-modified PVC membranes were characterized by Raman spectroscopy and scanning electron microscopy(SEM).The properties of the COSOCE-modified PVC membrane were characterized by contact angle measurements,universal testing machine,thermogravimetric analysis(TGA),and differential scanning calorimetry(DSC).The results revealed that(1)The COSOCE-modified PVC membranes exhibit a good microscopic morphology.Combined with energy-dispersive X-ray spectroscopy(EDS)and contact angle measurement results,the COSOCE-modified PVC membranes are confirmed to be a hydrophilic material.(2)The modified PVC membrane with 60%COSOCE exhibited the best mechanical properties.The tensile strength reached 23.56±2.94 MPa.(3)COSOCE-modified PVC material exhibited better thermal stability,with a loss rate of less than 75%at the end of the first decomposition stage.Compared with that of the dioctyl-phthalate(DOP)-modified PVC membrane,the initial decomposition temperature of PVC was increased by 1.17°C–8.17°C,and the residual rate was increased by 0.67%–5.75%.The carbon–carbon double bond in the COSOCE molecular structure can remove the free radicals generated during the degradation of PVC material and slow down the decomposition rate of PVC.In addition,the double bond can be cross-linked partially with the PVC molecular chain containing the conjugated polyene structure,thereby increasing the movement resistance of the PVC molecular chain segment.Hence,COSOCE can replace DOP as a PVC plasticizer.

Recent Advance in Synaptic Plasticity Modulation Techniques for Neuromorphic Applications

Manipulating the expression of synaptic plasticity of neuromorphic devices provides fascinating opportunities to develop hardware platforms for artifi-cial intelligence.However,great efforts have been devoted to exploring biomimetic mechanisms of plasticity simulation in the last few years.Recent progress in various plasticity modulation techniques has pushed the research of synaptic electronics from static plasticity simulation to dynamic plasticity modulation,improving the accuracy of neuromorphic computing and providing strategies for implementing neuromorphic sensing functions.Herein,several fascinating strategies for synap-tic plasticity modulation through chemical techniques,device structure design,and physical signal sensing are reviewed.For chemical techniques,the underly-ing mechanisms for the modification of functional materials were clarified and its effect on the expression of synaptic plasticity was also highlighted.Based on device structure design,the reconfigurable operation of neuromorphic devices was well demonstrated to achieve programmable neuromorphic functions.Besides,integrating the sensory units with neuromorphic processing circuits paved a new way to achieve human-like intelligent perception under the modulation of physical signals such as light,strain,and temperature.Finally,considering that the relevant technology is still in the basic exploration stage,some prospects or development suggestions are put forward to promote the development of neuromorphic devices.

Mitochondrial recruitment in myelin:an anchor for myelin dynamics and plasticity?

Optimal propagation of neuronal electrical impulses depends on the insulation of axons by myelin,produced in the central nervous system by oligodendrocytes.Myelin is an extension of the oligodendrocyte plasma membrane,which wraps around an axon to form a compact multi-layered sheath.Myelin is composed of a substantially higher proportion of lipids compared to other biological membranes and enriched in a small number of specialized proteins.

Glial progenitor heterogeneity and plasticity in the adult spinal cord

Glial progenitor cells were reported to have the capacity to generate various types of cells in both the central nervous system(CNS)and peripheral nervous system.Glial progenitor cells can respond to diverse environmental signals and transform into distinct populations,each serving specific functions.Notably,the adult spinal cord hosts various populations of glial progenitors,a region integral to the central nervous system.During development,glial progenitors express glial fibrillary acidic protein(GFAP;Dimou and Gotz,2014).However,the specific identities of GFAP-expressing progenitors in the adult spinal cord were not thoroughly investigated.

Perspectives in human brain plasticity sparked by glioma invasion:from intraoperative(re)mappings to neural reconfigurations

Exploring the aptitude of the human brain to compensate functional consequences of a lesion damaging its structural architecture is a key challenge to improve patient care in various neurological diseases,to optimize neuroscientifically-informed strategies of postlesional rehabilitation,and ultimately to develop innovative neuro-regenerative therapies.The term‘plasticity’,initially referring to the intrinsic propensity of neurons to modulate their synaptic transmission in a learning situation,was progressively transposed to brain injury research and clinical neurosciences.Indeed,in the event of brain damage,adaptive mechanisms of compensation allow a partial reshaping of the structure and activities of the central nervous system,thus permitting to some extent the maintenance of brain functions.

From mice to humans:a need for comparable results in mammalian neuroplasticity

Brain plasticity-A universal tool with many variations:The study of brain plasticity has been gaining interest since almost a century and has now reached a huge amount of information(>80,000 results in PubMed).Overall,different types of plasticity,including stem cell-driven genesis of new neurons(adult neurogenesis),cells in arrested maturation(dormant neurons),neuro-glial and synaptic plasticity,can coexist and contribute to grant plastic changes in the brain,from a cellular to system level(Benedetti and Couillard-Despres,2022;Bonfanti et al.,2023).

Contribution of mechanical forces to structural synaptic plasticity:insights from 3D cellular motility mechanisms

Cells,tissues,and organs are constantly subjected to the action of mechanical forces from the extracellular environment-and the nervous system is no exception.Cell-intrinsic properties such as membrane lipid composition,abundance of mechanosensors,and cytoskeletal dynamics make cells more or less likely to sense these forces.Intrinsic and extrinsic cues are integrated by cells and this combined information determines the rate and dynamics of membrane protrusion growth or retraction(Yamada and Sixt,2019).Cell protrusions are extensions of the plasma membrane that play crucial roles in diverse contexts such as cell migration and neuronal synapse formation.In the nervous system,neurons are highly dynamic cells that can change the size and number of their pre-and postsynaptic elements(called synaptic boutons and dendritic spines,respectively),in response to changes in the levels of synaptic activity through a process called plasticity.Synaptic plasticity is a hallmark of the nervous system and is present throughout our lives,being required for functions like memory formation or the learning of new motor skills(Minegishi et al.,2023;Pillai and Franze,2024).

Photocatalytic Degradation of Plastic Waste: Recent Progress and Future Perspectives

Microplastics are persistent anthropogenic pollutants that have become a global concern due to their widespread distribution and unfamiliar threat to the environment and living organisms. Conventional technologies are unable to fully decompose and mineralize plastic waste. Therefore, there is a need to develop an environmentally friendly, innovative and sustainable photocatalytic process that can destroy these wastes with much less energy and chemical consumption. In photocatalysis, various nanomaterials based on wide energy band gap semiconductors such as TiO2 and ZnO are used for the conversion of plastic contaminants into environmentally friendly compounds. In this work, the removal of plastic fragments by photocatalytic reactions using newly developed photocatalytic composites and the mechanism of photocatalytic degradation of microplastics are systematically investigated. In these degradation processes, sunlight or an artificial light source is used to activate the photocatalyst in the presence of oxygen.

Impact of Plastic Waste on the Human Health in Low-Income Countries: A Systematic Review

Background: Plastic pollution is the accumulation of waste composed of plastic and its derivatives all over the environment. Whether in the form of visible garbage or microparticles, as it slowly degrades, plastic pollution poses significant threats to terrestrial and aquatic habitats and the wildlife that call them home, whether through ingestion, entanglement or exposure to the chemicals contained in the material. Unfortunately, there is a lack of documentation on the impact of plastic waste on human health in low- and middle-income countries (LMICs). Methods: We searched five electronic databases (PubMed, Embase, Global Health, CINAHL and Web of Science) and gray literature, following the preferred reporting elements for systematic reviews and meta-analyses (PRISMA), for the impact of plastic waste on human health in developing countries. We included quantitative and qualitative studies written in English and French. We assessed the quality of the included articles using the Mixed Methods Appraisal tool (MMAT). Results: A total of 3779 articles were initially identified by searching electronic databases. After eliminating duplicates, 3167 articles were reviewed based on title and abstract, and 26 were selected for full-text review. Only three articles were retained. The three articles dealt with practices likely to lead to oral exposure to plastic chemicals in human health, as well as the level of awareness of participants concerning the possible impact of plastic on human health, namely, the use of plastic baby bottles, the use of microwaves to cook food and reheat precooked food, the use of plastic bottles to store water in the refrigerator, water purifier containers with plastic bodies and plastic lunch boxes, the reuse of plastic bags and the inadequacy of treatment facilities. Conclusion: Plastic waste poses different risks to human health at every stage of its life cycle. Hence, strategies must be adopted to raise public awareness of the dangers of plastic waste to their health. Trial registration: The review protocol is registered in the PROSPERO international prospective register of systematic reviews (ID = CRD42023409087).

Age-related differences in long-term potentiation-like plasticity and shortlatency afferent inhibition and their association with cognitive function

Background The neurophysiological differences in cortical plasticity and cholinergic system function due to ageing and their correlation with cognitive function remain poorly understood.Aims To reveal the differences in long-term potentiation(LTP)-like plasticity and short-latency afferent inhibition(SAl)between older and younger individuals,alongside their correlation with cognitive function using transcranial magnetic stimulation(TMS).Methods The cross-sectional study involved 31 younger adults aged 18-30 and 46 older adults aged 60-80.All participants underwent comprehensive cognitive assessments and a neurophysiological evaluation based on TMS.Cognitive function assessments included evaluations of global cognitive function,language,memory and executive function.The neurophysiological assessment included LTP-like plasticity and SAl.Results The findings of this study revealed a decline in LTP among the older adults compared with the younger adults(wald χ^(2)=3.98,p=0.046).Subgroup analysis further demonstrated a significant reduction in SAl level among individuals aged 70-80 years in comparison to both the younger adults(SAI(N20)):(t=-3.37,p=0.018);SAl(N20+4):(t=-3.13,p=0.038)and those aged 60-70(SAl(N20)):(t=3.26,p=0.025);SAl(N20+4):(t=-3.69,p=0.006).Conversely,there was no notable difference in SAl level between those aged 60-70 years and the younger group.Furthermore,after employing the Bonferroni correction,the correlation analysis revealed that only the positive correlation between LTP-like plasticity and language function(r=0.61,p<0.001)in the younger group remained statistically significant.Conclusions During the normal ageing process,a decline in synaptic plasticity may precede cholinergic system dysfunction.In individuals over 60 years of age,there is a reduction in LTP-like plasticity,while a decline in cholinergic system function is observed in those over 70.Thus,the cholinergic system may play a vital role in preventing cognitive decline during normal ageing.In younger individuals,LTP-like plasticity might represent a potential neurophysiological marker for language function.

Green synthesis of ZSM-5 using silica fume and catalytic co-cracking of lignin and plastics for production of monocyclic aromatics

ZSM-5 with hierarchical pore structure was synthesized by a simple two-step hydrothermal crystallization from silica fume without using any organic ammonium templates.The synthesized ZSM-5 were oval shaped particles with a particle size about 2.0 μm and weak acid-dominated with proper Brønsted(B)and Lewis(L)acid sites.The ZSM-5 was used for catalytic co-cracking of n-octane and guaiacol,lowdensity polyethylene(LDPE)and alkali lignin(AL)to enhance the production of benzene,toluene,ethylbenzene and xylene(BTEX).The most significant synergistic effect occurred at n-octane/guaiacol at 1:1 and LDPE/AL at 1:3,under the condition,the achieved BTEX selectivity were 24%and 33%(mass)higher than the calculated values(weighted average).The highest BTEX selectivity reached 88.5%,which was 3.7%and 54.2%higher than those from individual cracking LDPE and AL.The synthesized ZSM-5 exhibited superior catalytic performance compared to the commercial ZSM-5,indicating potential application prospect.

Timing effect of high temperature exposure on the plasticity of internode and plant architecture in maize

The occurrence of high temperature(HT)in crop production is becoming more frequent and unpredictable with global warming,severely threatening food security.The state of an organ’s growth and development is largely determined by the temperature conditions it is exposed to over time.Maize is the main cereal crop,and its stem growth and plant architecture are closely related to lodging resistance,and especially sensitive to temperature.However,systematic research on the timing effect of HT on the sequentially developing internode and stem is currently lacking.To identify the timing effect of HT on the morphology and plasticity of the stem in maize,two hybrids(Zhengdan 958(ZD958),Xianyu 335(XY335))characterized by distinct morphological traits in the stem were exposed to a 7-day HT treatment from the V6 to V17 stages(Vn presents the vegetative stage with n leaves fully expanded)in 2019-2020.The results demonstrated that exposure to HT during V6-V12 accelerated the rapid elongation of stems.For instance,HT occurring at V7 and V12 specifically promoted the lengths and weights of the 3rd-5th and 9th-11th internodes,respectively.Meanwhile,HT slowed the growth of internodes adjacent to the promoted internodes.Interestingly,compared with control,the plant height was significantly increased soon after HT treatment,but the promotion effect became narrower at the subsequent flowering stage,demonstrating a self-adjusting mechanism in the maize plant in response to HT.Importantly,HT altered the plant architectures,including a rising of the ear position and increase in the ear position coefficient.XY335 exhibited greater sensitivity in stem development than ZD958 under HT treatment.These findings improve our systematic understanding of the plasticity of internode and plant architecture in response to the timing of HT exposure.

Upcycling plastic wastes into value-added products via electrocatalysis and photoelectrocatalysis

Plastic,renowned for its versatility,durability,and cost-effectiveness,is indispensable in modern society.Nevertheless,the annual production of nearly 400 million tons of plastic,coupled with a recycling rate of only 9%,has led to a monumental environmental crisis.Plastic recycling has emerged as a vital response to this crisis,offering sustainable solutions to mitigate its environmental impact.Among these recycling efforts,plastic upcycling has garnered attention,which elevates discarded plastics into higher-value products.Here,electrocatalytic and photoelectrocatalytic treatments stand at the forefront of advanced plastic upcycling.Electrocatalytic or photoelectrocatalytic treatments involve chemical reactions that facilitate electron transfer through the electrode/electrolyte interface,driven by electrical or solar energy,respectively.These methods enable precise control of chemical reactions,harnessing potential,current density,or light to yield valuable chemical products.This review explores recent progress in plastic upcycling through electrocatalytic and photoelectrocatalytic pathways,offering promising solutions to the plastic waste crisis and advancing sustainability in the plastics industry.