[Objectives] To study the effect of "acupressure therapy" on anti-inflammatory mechanism in obesity-induced IR rats. [Methods] 10 rats were randomly selected and fed with normal diet as blank group, and the ...[Objectives] To study the effect of "acupressure therapy" on anti-inflammatory mechanism in obesity-induced IR rats. [Methods] 10 rats were randomly selected and fed with normal diet as blank group, and the remaining 30 rats were fed with high-fat diet for 8 weeks. The obesity-induced IR model was induced and divided into two groups: model group and acupressure group. The acupressure group was treated by "acupressure therapy" three times a week for 6 weeks;the model group was taken 3 times at the same time every week, and the supine binding experiment lasted for 10 min for 6 weeks. Morphological observation was carried out before and after the experiment, mainly observing the general conditions and body weight. After the last intervention, the animals were killed and samples were collected. Western Blot method was used to detect the expression of TNF-α and IL-6 protein in adipose tissue of the three groups. [Results] Compared with the blank group, the expression of TNF-α and IL-6 protein in adipose tissue of the model group increased significantly ( P <0.01);compared with the model group, the expression of TNF-α and IL-6 protein in adipose tissue of the acupressure group decreased significantly ( P <0.01). [Conclusions] After intervening in the obesity-induced IR rats with acupressure method, the status of insulin resistance in obese rats was improved by inhibiting the expression of inflammatory factors.展开更多
Diabetic retinopathy(DR),as a common microvascular complication of diabetes,is the result of the interaction of multiple factors and multiple mechanisms.Inflammation is one of the important pathophysiological mechanis...Diabetic retinopathy(DR),as a common microvascular complication of diabetes,is the result of the interaction of multiple factors and multiple mechanisms.Inflammation is one of the important pathophysiological mechanisms of DR.Leukocytes accumulate and adhere to the surface of endothelial cells,glial cell activation and its dysfunction,and the release of vascular endothelial growth factor,interleukin and other inflammatory factors are directly related to the occurrence and development of DR inflammation.Antiinflammation plays an important role in the treatment of DR.Studies have shown that traditional Chinese medicine has a unique advantage in targeting the inflammatory mechanism of DR.Therefore,the inflammatory cells,inflammatory factors and related Chinese medicines closely related to DR are reviewed,in order to provide references for the early prevention and treatment of DR.展开更多
Objective:To investigate the effect and anti-inflammatory mechanism the effect of Flemingia Roxb.exAit extract on acute gouty arthritis.Methods:Sixty SD rats were randomly divided into 6 groups by weight,control and m...Objective:To investigate the effect and anti-inflammatory mechanism the effect of Flemingia Roxb.exAit extract on acute gouty arthritis.Methods:Sixty SD rats were randomly divided into 6 groups by weight,control and model group,(100、150、200 mg/kg)of Flemingia Roxb.exAit extract group and colchicine group.The rats of each group were given by intragastric for 7 days of continuous administration,meanwhile,there were given 0.9%NaCl solution instead as control and model group.The acute gouty arthritis model was constructed through right ankle joint cavity injection of sodium urate crystal solutionon day 5 after 1 h,but rats in the negative control group were injected with 0.9%NaCl solution into the articular cavity of the right foot.The general condition of rats and the degree of joint swelling,and the gait was observed after constructed model.To detected the joint fluid IL-1β、TNF-α、IL-6 indicators,and the expression of NLRP3,Caspase-1 protein in ankle joint tissue for 2 hours after the last administration.Results:Groups of Flemingia Roxb.exAit extract could markedly reduce the joint swelling on acute gouty arthritis rat model,improve gait in a dose-dependent manner,high dose group of Flemingia Roxb.exAit extract did particularly well(Pjoint swelling<0.01;Pgait<0.05),close to the therapeutic effect colchicine group.Further mechanism studies show that the joint fluid IL-1β、TNF-α、IL-6 level was reduced by Flemingia Roxb.exAit extract group,the expressions of NLRP3、Caspase-1 protein of Flemingia Roxb.exAit extract group was decreased observbly than model group,but the most obvious is that high dose group as well as colchicine group(PNALP3<0.01;PCaspase-1<0.01).Conclusion:Flemingia Roxb.exAit extract has the effect of treating acute gouty arthritis and its mechanism may be related toinhibiting NLRP3 inflammasome activation and inhibiting inflammatory response.展开更多
Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlu...Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlusion method, and the right vagus nerve was given electrical stimulation(constant current of 0.5 m A; pulse width, 0.5 ms; frequency, 20 Hz; duration, 30 seconds; every 5 minutes for a total of 60 minutes) 30 minutes, 12 hours, and 1, 2, 3, 7 and 14 days after surgery. Electrical stimulation of the vagus nerve substantially reduced infarct volume, improved neurological function, and decreased the expression levels of tumor necrosis factor-α and interleukin-6 in rats with focal cerebral ischemia. The experimental findings indicate that the neuroprotective effect of vagus nerve stimulation following cerebral ischemia may be associated with the inhibition of tumor necrosis factor-α and interleukin-6 expression.展开更多
In October 2021,an international collaborative study on the use of electroacupuncture(EA)to treat inflammation was published in the journal Nature by Dr.Qiufu Ma’s team.Based on the results of EA on inflammation in t...In October 2021,an international collaborative study on the use of electroacupuncture(EA)to treat inflammation was published in the journal Nature by Dr.Qiufu Ma’s team.Based on the results of EA on inflammation in the mouse model of lipopolysaccharide inflammatory storm,the study showed that the distal effect of acupuncture can be achieved by“driving the vagus-adrenal axis(through the adrenal medulla,by releasing catecholamines).”PROKR2Cre-marked sensory neurons,which innervate the deep hindlimb fascia but not the abdominal fascia,are crucial for driving this axis.The study suggests the existence of specificity distribution of acupoints,that different EA stimulation intensities or different needle penetration depths have different therapeutic effects,that photosensitive stimulation may be a substitute for needle acupuncture,and that massage,stretching and body movements may also activate PROKR2Cremarkable dorsal root ganglion sensory neurons and elicit anti-inflammatory effects.However,results of some other studies are contrary to the conclusions of Ma’s team.For examples:low-intensity EA at GB30 point significantly reduced the inflammation in the rat model of persistent inflammation,which is more relevant to the real daily acupuncture practice,and this effect was partly related to the adrenal cortex and associated with the stimulation of corticosterone and adrenocorticotropic hormone;manual acupuncture(similar to the low-intensity EA)at KI3,Zhichuan point(an extra point),etc.was effective in a severe COVID-19 patient with sepsis;stimulating ST25 with low-intensity EA or manual acupuncture was effective against gastrointestinal inflammations;the above mentioned points are not in an area enriched with PROKR2Cre-marked sensory nerve endings.Evidence shows that the mechanism of EA against inflammation includes modulating multi-systems,multi-levels and multi-targets,which does not limit to“driving the vagus-adrenal axis.”展开更多
Inflammatory bowel disease(IBD)is characterized by recurrent attacks and long courses,and the number of patients has expanded rapidly year by year.Additionally,current conventional strategies exist serious adverse eff...Inflammatory bowel disease(IBD)is characterized by recurrent attacks and long courses,and the number of patients has expanded rapidly year by year.Additionally,current conventional strategies exist serious adverse effects.In this case,it is an urgent issue to find out an effective and safe treatment.Functional oligosaccharides possess safe and excellent physiological activities,and have attracted enormous attention due to their great therapeutic potential for IBD.This review emphasizes the attenuating effects of distinct functional oligosaccharides on IBD and their structure,and summarizes the main mechanisms from the aspects of regulating intestinal fl ora structure,repairing intestinal barrier,modulating immune function and mediating related signaling pathways in order to reveal the relationship between functional oligosaccharides,immune regulation,intestinal epithelial cells,gut fl ora and IBD treatment.Oligosaccharides possess excellent protective effects on IBD,and can be considered as safe and functional ingredients in the health food and pharmaceutical industry.展开更多
Inflammatory jaw bone diseases are common in stomatology,including periodontitis,peri-implantitis,medication-related osteonecrosis of the jaw,radiation osteomyelitis of the jaw,age-related osteoporosis,and other speci...Inflammatory jaw bone diseases are common in stomatology,including periodontitis,peri-implantitis,medication-related osteonecrosis of the jaw,radiation osteomyelitis of the jaw,age-related osteoporosis,and other specific infections.These diseases may lead to tooth loss and maxillofacial deformities,severely affecting patients'quality of life.Over the years,the reconstruction of jaw bone deficiency caused by inflammatory diseases has emerged as a medical and socioeconomic challenge.Therefore,exploring the pathogenesis of inflammatory diseases associated with jaw bones is crucial for improving prognosis and developing new targeted therapies.Accumulating evidence indicates that the integrated bone formation and dysfunction arise from complex interactions among a network of multiple cell types,including osteoblast-associated cells,immune cells,blood vessels,and lymphatic vessels.However,the role of these different cells in the inflammatory process and the'rules'with which they interact are still not fully understood.Although many investigations have focused on specific pathological processes and molecular events in inflammatory jaw diseases,few articles offer a perspective of integration.Here,we review the changes and mechanisms of various cell types in inflammatory jaw diseases,with the hope of providing insights to drive future research in this field.展开更多
Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity ag...Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.展开更多
The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and tempora...The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass.展开更多
Inflammatory bowel disease(IBD)is a nonspecific inflammatory disease of the intestine that includes Crohn’s disease and ulcerative colitis.Because IBD is difficult to heal and easily relapses,it could worsen patient ...Inflammatory bowel disease(IBD)is a nonspecific inflammatory disease of the intestine that includes Crohn’s disease and ulcerative colitis.Because IBD is difficult to heal and easily relapses,it could worsen patient quality of life and increase economic burdens.Curcumin(CUR)is a bioactive component derived from the rhizome of turmeric(Curcuma longa).Many basic and clinical studies have shown that CUR can efficiently treat IBD by decreasing the activity of proinflammatory cytokines by communicating with transcription factors and signaling molecules.However,due to the limitations of being almost insoluble in aqueous solutions and having low oral bioavailability,it is important to select appropriate pharmaceutical preparations.展开更多
Sequelae of Pelvic Inflammatory Diseases (SPID) is a common and frequent disease in gynecology, which adversely affects women’s reproductive health and quality of life due to its prolonged course. In recent years, tr...Sequelae of Pelvic Inflammatory Diseases (SPID) is a common and frequent disease in gynecology, which adversely affects women’s reproductive health and quality of life due to its prolonged course. In recent years, traditional Chinese medicine (TCM) in China has gradually shown its clinical advantages in the treatment of SPID. Therefore, the present review summarizes the etiology and pathogenesis of SPID, the evidence typology, and the clinical application effects of moxibustion, herbal retention enema, acupoint compresses, external application of traditional Chinese medicine, auricular pressure beans, tuina massage, traditional Chinese medicine gongfu, and other commonly used Chinese medicine nursing techniques, with the aim of providing references and experiences for the subsequent related studies.展开更多
Understanding the mechanical properties and multiscale failure mechanism of frozen soft rock is an important prerequisite for the construction safety of tunnels,artificially frozen ground and other infrastructure in c...Understanding the mechanical properties and multiscale failure mechanism of frozen soft rock is an important prerequisite for the construction safety of tunnels,artificially frozen ground and other infrastructure in cold regions.In this study,the triaxial compression test are performed on mudstone in the weakly cemented soft rock strata in the mining area of western China,and the mechanical characteristics and failure mechanism of weakly cemented mudstone are systematically investigated under the combined action of freezing and loading.Furthermore,the quantitative relationship between the microstructural parameters and the macroscopic strength and deformation parameters is established based on fractal theory.Thus,the failure mechanism of frozen weakly cemented mudstone is revealed on both micro- and macro-scales.The results show that temperature and confining pressure significantly affects the elastic modulus and peak strength of weakly cemented mudstone.With decreasing temperature,the compressive strength increases,while the corresponding peak strain decreases gradually.On the deformation curve,the plastic deformation stage is shortened,and the brittle fracture feature at the post-peak stage is more prominent,and the elastic modulus correspondingly increases with decreasing temperature.Under low-temperature conditions,most of the weakly cemented mudstone undergoes microscopic shear failure along the main fracture surface.The micro-fracture morphology characteristics of weakly cemented mudstone under different temperatures are quantified via the fractal dimension,and an approximately exponential relationship can be obtained among the fractal dimension and the temperature,compressive strength and elastic modulus.展开更多
The study of the brain and its complex functions is highly fascinating and,at the same time,extremely important.Indeed,furthering our understanding of the biology of neurons and synapses is a prerequisite to uncover t...The study of the brain and its complex functions is highly fascinating and,at the same time,extremely important.Indeed,furthering our understanding of the biology of neurons and synapses is a prerequisite to uncover the mechanisms involved in memory formation and the coordination of movement as well as their alterations occurring in several neurological disorders.展开更多
Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of hum...Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of human diseases.His educational journey was marked by frequent changes in schools due to his parents’occupational relocations.However,despite these challenges,he consistently displayed diligence and was admitted to the East China University of Science and Technology,Shanghai,after completing high school in 1980.He remained an active and loyal member of the School of Biotechnology at the university.展开更多
The utilisation of polygenic scoring models may enhance the clinician’s ability to risk stratify an inflammatory bowel disease patient’s individual risk for venous thromboembolism(VTE)and guide the appropriate usage...The utilisation of polygenic scoring models may enhance the clinician’s ability to risk stratify an inflammatory bowel disease patient’s individual risk for venous thromboembolism(VTE)and guide the appropriate usage of VTE thromboprophylaxis,yet there is a need to validate such models in ethnically diverse populations.展开更多
Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine mode...Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine model of pregnancy.We hypothesized that the FGR results from the BPA-induced insufficiency and barrier dysfunction of the placenta,oxidative stress,inflammatory responses,autophagy and endoplasmic reticulum stress(ERS).However,precise mechanisms underlying the BPA-induced placental dysfunction,and subsequently,FGR,as well as the potential involvement of placental ERS in these complications,remain to be investigated.Methods In vivo experiment,16 twin-pregnant(from d 40 to 130 of gestation)Hu ewes were randomly distributed into two groups(8 ewes each).One group served as a control and received corn oil once a day,whereas the other group received BPA(5 mg/kg/d as a subcutaneous injection).In vitro study,ovine trophoblast cells(OTCs)were exposed to 4 treatments,6 replicates each.The OTCs were treated with 400μmol/L BPA,400μmol/L BPA+0.5μg/m L tunicamycin(Tm;ERS activator),400μmol/L BPA+1μmol/L 4-phenyl butyric acid(4-PBA;ERS antagonist)and DMEM/F12 complete medium(control),for 24 h.Results In vivo experiments,pregnant Hu ewes receiving the BPA from 40 to 130 days of pregnancy experienced a decrease in placental efficiency,progesterone(P4)level and fetal weight,and an increase in placental estrogen(E2)level,together with barrier dysfunctions,OS,inflammatory responses,autophagy and ERS in type A cotyledons.In vitro experiment,the OTCs exposed to BPA for 24 h showed an increase in the E2 level and related protein and gene expressions of autophagy,ERS,pro-apoptosis and inflammatory response,and a decrease in the P4 level and the related protein and gene expressions of antioxidant,anti-apoptosis and barrier function.Moreover,treating the OTCs with Tm aggravated BPA-induced dysfunction of barrier and endocrine(the increased E2 level and decreased P4 level),OS,inflammatory responses,autophagy,and ERS.However,treating the OTCs with 4-PBA reversed the counteracted effects of Tm mentioned above.Conclusions In general,the results reveal that BPA exposure can cause ERS in the ovine placenta and OTCs,and ERS induction might aggravate BPA-induced dysfunction of the placental barrier and endocrine,OS,inflammatory responses,and autophagy.These data offer novel mechanistic insights into whether ERS is involved in BPA-mediated placental dysfunction and fetal development.展开更多
[Objectives]To observe the effects of Wuwei Xiaodu Decoction on uterine energy metabolism and serum inflammatory factors in the acute pelvic inflammatory disease(APID)model.[Methods]75 Wistar rats(females)were randoml...[Objectives]To observe the effects of Wuwei Xiaodu Decoction on uterine energy metabolism and serum inflammatory factors in the acute pelvic inflammatory disease(APID)model.[Methods]75 Wistar rats(females)were randomly divided into control group,model group and Wuwei Xiaodu Decoction low,medium and high dose groups(n=15).Except for the control group,the rat APID model was established by right uterine inoculation.On the fifth day after inoculation,the low,medium and high dose groups of Wuwei Xiaodu Decoction were administered at 4,8 and 16 g/kg,and the control group and model group received normal saline.Rats were killed 12 h after nondose administration,blood was collected from the abdominal aorta and measured by ELISA for serum interleukin-6(interleukin-6,IL-6),IL-8,and C-reactive proteins(CRP);the right uterus of rats was tested for high-energy phosphate adenosine phosphate(AMP),adenosine diphosphate(ADP),adenosine triphosphate(ATP)and total adenine nucleotides(TAN)level to evaluate the uterine energy metabolism.[Results]AMP,ADP,ATP and TAN were significantly higher in the Wuwei Xiaodu Decoction of low,medium and high dose than the model group,while the serum IL-6,IL-8 and CRP were significantly lower than the model group,and the difference between the low,medium and high doses(P<0.05).[Conclusions]The Wuwei Xiaodu Decoction can dose-dependent promote uterine energy metabolism and inhibit inflammatory response in APID model rats.展开更多
BACKGROUND Inflammatory bowel disease(IBD)was previously regarded as a Western disease;however,its incidence is increasing in the East.The epidemiology of IBD in Asia differs significantly from the patterns in the Wes...BACKGROUND Inflammatory bowel disease(IBD)was previously regarded as a Western disease;however,its incidence is increasing in the East.The epidemiology of IBD in Asia differs significantly from the patterns in the West.AIM To comprehensively investigate the epidemiology of IBD in South Korea,inclu-ding its incidence,prevalence,medication trends,and outcomes.METHODS We analyzed claims data from the Health Insurance Review and Assessment Service and Rare and Intractable Diseases(RIDs),operated by the National Health Insurance Service of South Korea.Patients with IBD were identified based on the International Classification of Diseases,Tenth Revision,and RID diagnostic codes for Crohn’s disease(CD)and ulcerative colitis(UC)from 2010 to 2018.RESULTS In total,14498 and 31409 patients were newly diagnosed with CD and UC,respectively,between 2010 and 2018.The annual average incidence of CD was 3.11 cases per 105 person-years,and that of UC was 6.74 cases per 10^(5) person-years.Since 2014,the incidence rate of CD has been stable,while that of UC has steadily increased,shifting the peak age group from 50-year-olds in 2010 to 20-year-olds in 2018.The CD and UC prevalence increased consistently over the study period;the use of 5-aminosali-cylates and corticosteroids gradually decreased,while that of immunomodulators and biologics steadily increased in both CD and UC.The clinical outcomes of IBD,such as hospitalization and surgery,decreased during the study period.CONCLUSION The CD incidence has been stable since 2014,but that of UC has increased with a shift to a younger age at peak incidence between 2010 and 2018.IBD clinical outcomes improved over time,with increased use of immunomodu-lators and biologics.展开更多
In this editorial,we comment on the article by Marangoni et al,published in the recent issue of the World Journal of Gastroenterology 2023;29:5618-5629,about“Diet as an epigenetic factor in inflammatory bowel disease...In this editorial,we comment on the article by Marangoni et al,published in the recent issue of the World Journal of Gastroenterology 2023;29:5618-5629,about“Diet as an epigenetic factor in inflammatory bowel disease”.The authors emphasized the role of diet,especially the interaction with genetics,in promoting the inflam-matory process in inflammatory bowel disease(IBD)patients,focusing on DNA methylation,histone modifications,and the influence of microRNAs.In this editorial,we explore the interaction between genetics,gut microbiota,and diet,in an only way.Furthermore,we provided dietary recommendations for patients with IBD.The Western diet,characterized by a low fiber content and deficiency the micronutrients,impacts short-chain fatty acids production and may be related to the pathogenesis of IBD.On the other hand,the consumption of the Mediter-ranean diet and dietary fibers are associated with reduced risk of IBD flares,particularly in Crohn’s disease(CD)patients.According to the dietary guidance from the International Organization for the Study of Inflammatory Bowel Diseases(IOIBD),the regular consumption of fruits and vegetables while reducing the consumption of saturated,trans,dairy fat,additives,processed foods rich in maltodextrins,and artificial sweeteners containing sucralose or saccharine is recommended to CD patients.For patients with ulcerative colitis,the IOIBD recommends the increased intake of natural sources of omega-3 fatty acids and follows the same restrictive recommendations aimed at CD patients,with the possible inclusion of red meats.In conclusion,IBD is a complex and hetero-geneous disease,and future studies are needed to elucidate the influence of epigenetics on diet and microbiota in IBD patients.展开更多
In order to obtain liquefied products with higher yields of aromatic molecules to produce mesophase pitch,a good understanding of the relevant reaction mechanisms is required.Reactive molecular dynamics simulations we...In order to obtain liquefied products with higher yields of aromatic molecules to produce mesophase pitch,a good understanding of the relevant reaction mechanisms is required.Reactive molecular dynamics simulations were used to study the thermal reactions of pyrene,1-methylpyrene,7,8,9,10-tetrahydrobenzopyrene,and mixtures of pyrene with 1-octene,cyclohexene,or styrene.The reactant conversion rates,reaction rates,and product distributions were calculated and compared,and the mechanisms were analyzed and discussed.The results demonstrated that methyl and naphthenic structures in aromatics might improve the conversion rates of reactants in hydrogen transfer processes,but their steric hindrances prohibited the generation of high polymers.The naphthenic structures could generate more free radicals and presented a more obvious inhibition effect on the condensation of polymers compared with the methyl side chains.It was discovered that when different olefins were mixed with pyrene,1-octene primarily underwent pyrolysis reactions,whereas cyclohexene mainly underwent hydrogen transfer reactions with pyrene and styrene,mostly producing superconjugated biradicals through condensation reactions with pyrene.In the mixture systems,the olefins scattered aromatic molecules,hindering the formation of pyrene trimers and higher polymers.According to the reactive molecular dynamics simulations,styrene may enhance the yield of dimer and enable the controlled polycondensation of pyrene.展开更多
基金Supported by National Natural Science Foundation of China(82174525)Jilin Science and Technology Development Plan Project(YDZJ202201ZYTS195)+2 种基金Jilin Natural Science Foundation(YDZJ202301ZYTS469)Jilin Traditional Chinese Medicine Science and Technology Project in 2022(2022128)2023 Youth Outstanding Discipline Backbone Training Project of Changchun University of Chinese Medicine(202304).
文摘[Objectives] To study the effect of "acupressure therapy" on anti-inflammatory mechanism in obesity-induced IR rats. [Methods] 10 rats were randomly selected and fed with normal diet as blank group, and the remaining 30 rats were fed with high-fat diet for 8 weeks. The obesity-induced IR model was induced and divided into two groups: model group and acupressure group. The acupressure group was treated by "acupressure therapy" three times a week for 6 weeks;the model group was taken 3 times at the same time every week, and the supine binding experiment lasted for 10 min for 6 weeks. Morphological observation was carried out before and after the experiment, mainly observing the general conditions and body weight. After the last intervention, the animals were killed and samples were collected. Western Blot method was used to detect the expression of TNF-α and IL-6 protein in adipose tissue of the three groups. [Results] Compared with the blank group, the expression of TNF-α and IL-6 protein in adipose tissue of the model group increased significantly ( P <0.01);compared with the model group, the expression of TNF-α and IL-6 protein in adipose tissue of the acupressure group decreased significantly ( P <0.01). [Conclusions] After intervening in the obesity-induced IR rats with acupressure method, the status of insulin resistance in obese rats was improved by inhibiting the expression of inflammatory factors.
基金2018 National Key Research and Development Plan Project(2018YFC1704100,2018YFC1704103)。
文摘Diabetic retinopathy(DR),as a common microvascular complication of diabetes,is the result of the interaction of multiple factors and multiple mechanisms.Inflammation is one of the important pathophysiological mechanisms of DR.Leukocytes accumulate and adhere to the surface of endothelial cells,glial cell activation and its dysfunction,and the release of vascular endothelial growth factor,interleukin and other inflammatory factors are directly related to the occurrence and development of DR inflammation.Antiinflammation plays an important role in the treatment of DR.Studies have shown that traditional Chinese medicine has a unique advantage in targeting the inflammatory mechanism of DR.Therefore,the inflammatory cells,inflammatory factors and related Chinese medicines closely related to DR are reviewed,in order to provide references for the early prevention and treatment of DR.
基金2016 Hainan Medical College Students Innovation and Entrepreneurship Training Program(No.HYCX2016055)2017 Hainan College Students Innovation and Entrepreneurship Training Program Project(No.2017098)。
文摘Objective:To investigate the effect and anti-inflammatory mechanism the effect of Flemingia Roxb.exAit extract on acute gouty arthritis.Methods:Sixty SD rats were randomly divided into 6 groups by weight,control and model group,(100、150、200 mg/kg)of Flemingia Roxb.exAit extract group and colchicine group.The rats of each group were given by intragastric for 7 days of continuous administration,meanwhile,there were given 0.9%NaCl solution instead as control and model group.The acute gouty arthritis model was constructed through right ankle joint cavity injection of sodium urate crystal solutionon day 5 after 1 h,but rats in the negative control group were injected with 0.9%NaCl solution into the articular cavity of the right foot.The general condition of rats and the degree of joint swelling,and the gait was observed after constructed model.To detected the joint fluid IL-1β、TNF-α、IL-6 indicators,and the expression of NLRP3,Caspase-1 protein in ankle joint tissue for 2 hours after the last administration.Results:Groups of Flemingia Roxb.exAit extract could markedly reduce the joint swelling on acute gouty arthritis rat model,improve gait in a dose-dependent manner,high dose group of Flemingia Roxb.exAit extract did particularly well(Pjoint swelling<0.01;Pgait<0.05),close to the therapeutic effect colchicine group.Further mechanism studies show that the joint fluid IL-1β、TNF-α、IL-6 level was reduced by Flemingia Roxb.exAit extract group,the expressions of NLRP3、Caspase-1 protein of Flemingia Roxb.exAit extract group was decreased observbly than model group,but the most obvious is that high dose group as well as colchicine group(PNALP3<0.01;PCaspase-1<0.01).Conclusion:Flemingia Roxb.exAit extract has the effect of treating acute gouty arthritis and its mechanism may be related toinhibiting NLRP3 inflammasome activation and inhibiting inflammatory response.
基金supported by the Beijing Natural Science Foundation of China,No.7122164
文摘Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlusion method, and the right vagus nerve was given electrical stimulation(constant current of 0.5 m A; pulse width, 0.5 ms; frequency, 20 Hz; duration, 30 seconds; every 5 minutes for a total of 60 minutes) 30 minutes, 12 hours, and 1, 2, 3, 7 and 14 days after surgery. Electrical stimulation of the vagus nerve substantially reduced infarct volume, improved neurological function, and decreased the expression levels of tumor necrosis factor-α and interleukin-6 in rats with focal cerebral ischemia. The experimental findings indicate that the neuroprotective effect of vagus nerve stimulation following cerebral ischemia may be associated with the inhibition of tumor necrosis factor-α and interleukin-6 expression.
文摘In October 2021,an international collaborative study on the use of electroacupuncture(EA)to treat inflammation was published in the journal Nature by Dr.Qiufu Ma’s team.Based on the results of EA on inflammation in the mouse model of lipopolysaccharide inflammatory storm,the study showed that the distal effect of acupuncture can be achieved by“driving the vagus-adrenal axis(through the adrenal medulla,by releasing catecholamines).”PROKR2Cre-marked sensory neurons,which innervate the deep hindlimb fascia but not the abdominal fascia,are crucial for driving this axis.The study suggests the existence of specificity distribution of acupoints,that different EA stimulation intensities or different needle penetration depths have different therapeutic effects,that photosensitive stimulation may be a substitute for needle acupuncture,and that massage,stretching and body movements may also activate PROKR2Cremarkable dorsal root ganglion sensory neurons and elicit anti-inflammatory effects.However,results of some other studies are contrary to the conclusions of Ma’s team.For examples:low-intensity EA at GB30 point significantly reduced the inflammation in the rat model of persistent inflammation,which is more relevant to the real daily acupuncture practice,and this effect was partly related to the adrenal cortex and associated with the stimulation of corticosterone and adrenocorticotropic hormone;manual acupuncture(similar to the low-intensity EA)at KI3,Zhichuan point(an extra point),etc.was effective in a severe COVID-19 patient with sepsis;stimulating ST25 with low-intensity EA or manual acupuncture was effective against gastrointestinal inflammations;the above mentioned points are not in an area enriched with PROKR2Cre-marked sensory nerve endings.Evidence shows that the mechanism of EA against inflammation includes modulating multi-systems,multi-levels and multi-targets,which does not limit to“driving the vagus-adrenal axis.”
基金financially supported by Sichuan Science and Technology Program[2021YFSY0035]Heilongjiang Touyan Team[HITTY-20190034].
文摘Inflammatory bowel disease(IBD)is characterized by recurrent attacks and long courses,and the number of patients has expanded rapidly year by year.Additionally,current conventional strategies exist serious adverse effects.In this case,it is an urgent issue to find out an effective and safe treatment.Functional oligosaccharides possess safe and excellent physiological activities,and have attracted enormous attention due to their great therapeutic potential for IBD.This review emphasizes the attenuating effects of distinct functional oligosaccharides on IBD and their structure,and summarizes the main mechanisms from the aspects of regulating intestinal fl ora structure,repairing intestinal barrier,modulating immune function and mediating related signaling pathways in order to reveal the relationship between functional oligosaccharides,immune regulation,intestinal epithelial cells,gut fl ora and IBD treatment.Oligosaccharides possess excellent protective effects on IBD,and can be considered as safe and functional ingredients in the health food and pharmaceutical industry.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(Grant No.PAPD-2018-87)Jiangsu Province Capability Improvement Project through Science,Technology and Education-Jiangsu Provincial Research Hospital Cultivation Unit(Grant No.YJXYYJSDW4)Jiangsu Provincial Medical Innovation Center(Grant No.CXZX202227).
文摘Inflammatory jaw bone diseases are common in stomatology,including periodontitis,peri-implantitis,medication-related osteonecrosis of the jaw,radiation osteomyelitis of the jaw,age-related osteoporosis,and other specific infections.These diseases may lead to tooth loss and maxillofacial deformities,severely affecting patients'quality of life.Over the years,the reconstruction of jaw bone deficiency caused by inflammatory diseases has emerged as a medical and socioeconomic challenge.Therefore,exploring the pathogenesis of inflammatory diseases associated with jaw bones is crucial for improving prognosis and developing new targeted therapies.Accumulating evidence indicates that the integrated bone formation and dysfunction arise from complex interactions among a network of multiple cell types,including osteoblast-associated cells,immune cells,blood vessels,and lymphatic vessels.However,the role of these different cells in the inflammatory process and the'rules'with which they interact are still not fully understood.Although many investigations have focused on specific pathological processes and molecular events in inflammatory jaw diseases,few articles offer a perspective of integration.Here,we review the changes and mechanisms of various cell types in inflammatory jaw diseases,with the hope of providing insights to drive future research in this field.
基金supported by National Natural Science Foundation of China(31972021)R&D Projects in Key Areas of Guangdong Province(2019B020212003)+4 种基金the Science and Technology Program of Guangzhou,China(202206010177)Guangdong key research and development program(2021B0202060001)Foshan and agricultural academy cooperation projectGuangdong Modern Agriculture project(2022KJ117)Aquatic Products Center Project of GAAS。
文摘Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.
基金National Natural Science Foundation of China(No.52178393)2023 High-level Talent Research Project from Yancheng Institute of Technology(No.xjr2023019)+1 种基金Open Fund Project of Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering(Grant No.YT202302)Science and Technology Innovation Team of Shaanxi Innovation Capability Support Plan(No.2020TD005).
文摘The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass.
文摘Inflammatory bowel disease(IBD)is a nonspecific inflammatory disease of the intestine that includes Crohn’s disease and ulcerative colitis.Because IBD is difficult to heal and easily relapses,it could worsen patient quality of life and increase economic burdens.Curcumin(CUR)is a bioactive component derived from the rhizome of turmeric(Curcuma longa).Many basic and clinical studies have shown that CUR can efficiently treat IBD by decreasing the activity of proinflammatory cytokines by communicating with transcription factors and signaling molecules.However,due to the limitations of being almost insoluble in aqueous solutions and having low oral bioavailability,it is important to select appropriate pharmaceutical preparations.
文摘Sequelae of Pelvic Inflammatory Diseases (SPID) is a common and frequent disease in gynecology, which adversely affects women’s reproductive health and quality of life due to its prolonged course. In recent years, traditional Chinese medicine (TCM) in China has gradually shown its clinical advantages in the treatment of SPID. Therefore, the present review summarizes the etiology and pathogenesis of SPID, the evidence typology, and the clinical application effects of moxibustion, herbal retention enema, acupoint compresses, external application of traditional Chinese medicine, auricular pressure beans, tuina massage, traditional Chinese medicine gongfu, and other commonly used Chinese medicine nursing techniques, with the aim of providing references and experiences for the subsequent related studies.
基金funding support from Natural Science Foundation of Shandong Province(Grant No.ZR2021QE187).
文摘Understanding the mechanical properties and multiscale failure mechanism of frozen soft rock is an important prerequisite for the construction safety of tunnels,artificially frozen ground and other infrastructure in cold regions.In this study,the triaxial compression test are performed on mudstone in the weakly cemented soft rock strata in the mining area of western China,and the mechanical characteristics and failure mechanism of weakly cemented mudstone are systematically investigated under the combined action of freezing and loading.Furthermore,the quantitative relationship between the microstructural parameters and the macroscopic strength and deformation parameters is established based on fractal theory.Thus,the failure mechanism of frozen weakly cemented mudstone is revealed on both micro- and macro-scales.The results show that temperature and confining pressure significantly affects the elastic modulus and peak strength of weakly cemented mudstone.With decreasing temperature,the compressive strength increases,while the corresponding peak strain decreases gradually.On the deformation curve,the plastic deformation stage is shortened,and the brittle fracture feature at the post-peak stage is more prominent,and the elastic modulus correspondingly increases with decreasing temperature.Under low-temperature conditions,most of the weakly cemented mudstone undergoes microscopic shear failure along the main fracture surface.The micro-fracture morphology characteristics of weakly cemented mudstone under different temperatures are quantified via the fractal dimension,and an approximately exponential relationship can be obtained among the fractal dimension and the temperature,compressive strength and elastic modulus.
基金supported by a grant from the Institut Professeur Baulieu (to DT)。
文摘The study of the brain and its complex functions is highly fascinating and,at the same time,extremely important.Indeed,furthering our understanding of the biology of neurons and synapses is a prerequisite to uncover the mechanisms involved in memory formation and the coordination of movement as well as their alterations occurring in several neurological disorders.
文摘Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of human diseases.His educational journey was marked by frequent changes in schools due to his parents’occupational relocations.However,despite these challenges,he consistently displayed diligence and was admitted to the East China University of Science and Technology,Shanghai,after completing high school in 1980.He remained an active and loyal member of the School of Biotechnology at the university.
文摘The utilisation of polygenic scoring models may enhance the clinician’s ability to risk stratify an inflammatory bowel disease patient’s individual risk for venous thromboembolism(VTE)and guide the appropriate usage of VTE thromboprophylaxis,yet there is a need to validate such models in ethnically diverse populations.
基金supported by the fund for the National 14th Five-Year Plan Key Research and Development Program(2021YFD1600702)XPCC Agricultural Science and Technology Innovation Project(NCG202232)the Top Talents Award Plan of Yangzhou University(2020)。
文摘Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine model of pregnancy.We hypothesized that the FGR results from the BPA-induced insufficiency and barrier dysfunction of the placenta,oxidative stress,inflammatory responses,autophagy and endoplasmic reticulum stress(ERS).However,precise mechanisms underlying the BPA-induced placental dysfunction,and subsequently,FGR,as well as the potential involvement of placental ERS in these complications,remain to be investigated.Methods In vivo experiment,16 twin-pregnant(from d 40 to 130 of gestation)Hu ewes were randomly distributed into two groups(8 ewes each).One group served as a control and received corn oil once a day,whereas the other group received BPA(5 mg/kg/d as a subcutaneous injection).In vitro study,ovine trophoblast cells(OTCs)were exposed to 4 treatments,6 replicates each.The OTCs were treated with 400μmol/L BPA,400μmol/L BPA+0.5μg/m L tunicamycin(Tm;ERS activator),400μmol/L BPA+1μmol/L 4-phenyl butyric acid(4-PBA;ERS antagonist)and DMEM/F12 complete medium(control),for 24 h.Results In vivo experiments,pregnant Hu ewes receiving the BPA from 40 to 130 days of pregnancy experienced a decrease in placental efficiency,progesterone(P4)level and fetal weight,and an increase in placental estrogen(E2)level,together with barrier dysfunctions,OS,inflammatory responses,autophagy and ERS in type A cotyledons.In vitro experiment,the OTCs exposed to BPA for 24 h showed an increase in the E2 level and related protein and gene expressions of autophagy,ERS,pro-apoptosis and inflammatory response,and a decrease in the P4 level and the related protein and gene expressions of antioxidant,anti-apoptosis and barrier function.Moreover,treating the OTCs with Tm aggravated BPA-induced dysfunction of barrier and endocrine(the increased E2 level and decreased P4 level),OS,inflammatory responses,autophagy,and ERS.However,treating the OTCs with 4-PBA reversed the counteracted effects of Tm mentioned above.Conclusions In general,the results reveal that BPA exposure can cause ERS in the ovine placenta and OTCs,and ERS induction might aggravate BPA-induced dysfunction of the placental barrier and endocrine,OS,inflammatory responses,and autophagy.These data offer novel mechanistic insights into whether ERS is involved in BPA-mediated placental dysfunction and fetal development.
文摘[Objectives]To observe the effects of Wuwei Xiaodu Decoction on uterine energy metabolism and serum inflammatory factors in the acute pelvic inflammatory disease(APID)model.[Methods]75 Wistar rats(females)were randomly divided into control group,model group and Wuwei Xiaodu Decoction low,medium and high dose groups(n=15).Except for the control group,the rat APID model was established by right uterine inoculation.On the fifth day after inoculation,the low,medium and high dose groups of Wuwei Xiaodu Decoction were administered at 4,8 and 16 g/kg,and the control group and model group received normal saline.Rats were killed 12 h after nondose administration,blood was collected from the abdominal aorta and measured by ELISA for serum interleukin-6(interleukin-6,IL-6),IL-8,and C-reactive proteins(CRP);the right uterus of rats was tested for high-energy phosphate adenosine phosphate(AMP),adenosine diphosphate(ADP),adenosine triphosphate(ATP)and total adenine nucleotides(TAN)level to evaluate the uterine energy metabolism.[Results]AMP,ADP,ATP and TAN were significantly higher in the Wuwei Xiaodu Decoction of low,medium and high dose than the model group,while the serum IL-6,IL-8 and CRP were significantly lower than the model group,and the difference between the low,medium and high doses(P<0.05).[Conclusions]The Wuwei Xiaodu Decoction can dose-dependent promote uterine energy metabolism and inhibit inflammatory response in APID model rats.
基金National Research Foundation of Korea,No.RS-2023-00227939.
文摘BACKGROUND Inflammatory bowel disease(IBD)was previously regarded as a Western disease;however,its incidence is increasing in the East.The epidemiology of IBD in Asia differs significantly from the patterns in the West.AIM To comprehensively investigate the epidemiology of IBD in South Korea,inclu-ding its incidence,prevalence,medication trends,and outcomes.METHODS We analyzed claims data from the Health Insurance Review and Assessment Service and Rare and Intractable Diseases(RIDs),operated by the National Health Insurance Service of South Korea.Patients with IBD were identified based on the International Classification of Diseases,Tenth Revision,and RID diagnostic codes for Crohn’s disease(CD)and ulcerative colitis(UC)from 2010 to 2018.RESULTS In total,14498 and 31409 patients were newly diagnosed with CD and UC,respectively,between 2010 and 2018.The annual average incidence of CD was 3.11 cases per 105 person-years,and that of UC was 6.74 cases per 10^(5) person-years.Since 2014,the incidence rate of CD has been stable,while that of UC has steadily increased,shifting the peak age group from 50-year-olds in 2010 to 20-year-olds in 2018.The CD and UC prevalence increased consistently over the study period;the use of 5-aminosali-cylates and corticosteroids gradually decreased,while that of immunomodulators and biologics steadily increased in both CD and UC.The clinical outcomes of IBD,such as hospitalization and surgery,decreased during the study period.CONCLUSION The CD incidence has been stable since 2014,but that of UC has increased with a shift to a younger age at peak incidence between 2010 and 2018.IBD clinical outcomes improved over time,with increased use of immunomodu-lators and biologics.
文摘In this editorial,we comment on the article by Marangoni et al,published in the recent issue of the World Journal of Gastroenterology 2023;29:5618-5629,about“Diet as an epigenetic factor in inflammatory bowel disease”.The authors emphasized the role of diet,especially the interaction with genetics,in promoting the inflam-matory process in inflammatory bowel disease(IBD)patients,focusing on DNA methylation,histone modifications,and the influence of microRNAs.In this editorial,we explore the interaction between genetics,gut microbiota,and diet,in an only way.Furthermore,we provided dietary recommendations for patients with IBD.The Western diet,characterized by a low fiber content and deficiency the micronutrients,impacts short-chain fatty acids production and may be related to the pathogenesis of IBD.On the other hand,the consumption of the Mediter-ranean diet and dietary fibers are associated with reduced risk of IBD flares,particularly in Crohn’s disease(CD)patients.According to the dietary guidance from the International Organization for the Study of Inflammatory Bowel Diseases(IOIBD),the regular consumption of fruits and vegetables while reducing the consumption of saturated,trans,dairy fat,additives,processed foods rich in maltodextrins,and artificial sweeteners containing sucralose or saccharine is recommended to CD patients.For patients with ulcerative colitis,the IOIBD recommends the increased intake of natural sources of omega-3 fatty acids and follows the same restrictive recommendations aimed at CD patients,with the possible inclusion of red meats.In conclusion,IBD is a complex and hetero-geneous disease,and future studies are needed to elucidate the influence of epigenetics on diet and microbiota in IBD patients.
基金financially supported by the National Natural Science Foundation of China(Approval No.42172168).
文摘In order to obtain liquefied products with higher yields of aromatic molecules to produce mesophase pitch,a good understanding of the relevant reaction mechanisms is required.Reactive molecular dynamics simulations were used to study the thermal reactions of pyrene,1-methylpyrene,7,8,9,10-tetrahydrobenzopyrene,and mixtures of pyrene with 1-octene,cyclohexene,or styrene.The reactant conversion rates,reaction rates,and product distributions were calculated and compared,and the mechanisms were analyzed and discussed.The results demonstrated that methyl and naphthenic structures in aromatics might improve the conversion rates of reactants in hydrogen transfer processes,but their steric hindrances prohibited the generation of high polymers.The naphthenic structures could generate more free radicals and presented a more obvious inhibition effect on the condensation of polymers compared with the methyl side chains.It was discovered that when different olefins were mixed with pyrene,1-octene primarily underwent pyrolysis reactions,whereas cyclohexene mainly underwent hydrogen transfer reactions with pyrene and styrene,mostly producing superconjugated biradicals through condensation reactions with pyrene.In the mixture systems,the olefins scattered aromatic molecules,hindering the formation of pyrene trimers and higher polymers.According to the reactive molecular dynamics simulations,styrene may enhance the yield of dimer and enable the controlled polycondensation of pyrene.
