The underlying proinflammatory mechanism of coagulation factor VⅡ in coronary artery disease (CAD) remains unclear. According to the inclusion criteria, 24 non-CAD subjects and 24 patients with CAD were enrolled. The expression levels of pro-inflammatory (CD14+CD86+, CD14+CD163-), anti-inflammatory monocytes (CD14+CD163+), CD14+CD142+ and CD14+PAR2+ monocytes in peripheral blood were detected by flow cytometry. The levels of TNF-α, IL-1β, IL-6, IL-10, and FVⅡ in plasma were determined by ELISA. In vitro experiments were conducted to induce inflammatory THP-1 by FVⅡa. The FVⅡa/TF complex inhibitor PCI-27,483 and PAR2 antagonist AZ3451 were used to clarify the mechanisms. Compared with the control group, the percentage of CD14+CD86+ pro-inflammatory monocytes were significantly increased in the CAD group, and further elevated after PCI. The results of the levels of CD14+CD142+ and CD14+PAR2+ monocytes showed the same trends with CD14+CD86+ pro-inflammatory monocytes. The levels of CD14+CD163+ anti-inflammatory monocytes and IL-10 were decreased in CAD patients, but increased after PCI. The pro-inflammatory factors and FVⅡ were significantly elevated in the CAD group and significantly decreased after PCI. Correlation analysis revealed that FVⅡ, TF, and PAR2 were significantly associated with CD14+CD86+ pro-inflammatory monocytes, and inflammatory factors. In vitro studies further confirmed that the FVⅡa/TF coagulation complex and PAR2 could activate NF-κB in monocytes and aggravate inflammation. Our findings suggest that crosstalk between monocytes and the coagulation complex might contribute to residual inflammation in CAD, potentially involving the FVIIa/TF/PAR2-NF-κB signaling pathway. Based on these observations, we hypothesize that blocking the interaction between clotting factors and monocytes could represent a promising therapeutic strategy to mitigate residual inflammation, but further rigorous experiments are needed for verification. Crosstalk between the monocytes and coagulation complex might cause residual inflammation in CAD. FVⅡa/TF/PAR2-NF-κB signal pathway is related to the activation of monocytes. Blocking the interaction between FVⅡa/TF coagulation complex and monocytes might be a promising therapeutic target to reduce residual inflammation.

OBJECTIVE:To investigate the efficacy and potential mechanisms of MGFKP on rabbit atherosclerotic models. METHODS:The left carotid balloon injury surgery were used to establish the rabbit atherosclerotic model, followed by the administration of MGFKP from the second postoperative for 6 weeks. Left carotid ultrasound and histological analysis were determined to evaluate the anti-atherosclerotic efficacy of MGFKP. Additionally, LC-MS and network pharmacology were conducted to identify the active ingredients of MGFKP and their targets, respectively. Lastly, core targets were selected to validate using immunohistochemical staining, western blot or ELISA. RESULTS:The results revealed that the vascular diameters difference, plaque area, plaque thickness, and ratio of vessel lumen to vessel cross-section radius were significantly improved following treatment with MGFKP (P<0.05). 539 ingredients of MGFKP were identified by LC-MS, and 23 ingredients were screened using SwissADME for network pharmacology. After combining the results of PPI and KEGG analyses with published literature, TLR4, NF-κB, IL-1β, and TNF-α were selected for the ensuing analyses. Molecular docking of most compounds showed satisfactory docking energy between TLR4, NF-κB, IL-1β, and TNF-α with their matched compounds. Finally, immunohistochemical analysis of TLR4 and western blot results of NF-κB, TNF-α, and IL-1β demonstrated that these proteins levels were obviously increased in the model group and significantly decreased in MGFKP group (P<0.05). The levels of TNF-α, IL-6, IL-1β were also significantly reduced following MGFKP treatment. CONCLUSIONS:MGFKP is a potential drug for the treatment of atherosclerosis, and might suppress the TLR4/NF-κB inflammatory pathway to alleviate atherosclerotic plaque progression.

Cardiovascular disease (CVD) remains the predominant cause of mortality and disability worldwide. Against this backdrop, finding effective drugs for the pharmacological treatment of CVD has become one of the most urgent and challenging issues in medical research. Garlic (Allium sativum L.) is one of the oldest plants and is world-renowned for its dietary and medicinal values. Allicin (diallyl thiosulfinate) is one of the primary natural active ingredients in garlic, which has been proven to have powerful cardioprotective effects and mediate various pathological processes related to CVD, such as inflammatory factor secretion, myocardial cell apoptosis, oxidative stress, and more. Therefore, allicin holds a promising application prospect in the treatment of CVD. This review summarized the biological functions of allicin and its potential mechanisms in CVD, including antioxidation, anti-inflammation, and anti-apoptosis effects. Reckoning with these, we delved into recent studies on allicin's cardioprotective effects concerning various CVDs, such as atherosclerosis, hypertension, myocardial infarction, arrhythmia, cardiac hypertrophy, heart failure, and cardiotoxicity. Further, considering the tremendous advancement in nanomedicine, nanotechnology-based drug delivery systems show promise in addressing limitations of allicin's clinical applications, including improving its solubility, stability, and bioavailability. Through this review, we hope to provide a reference for further research on allicin in cardioprotection and drug development.

In recent years,the incidence and mortality rates of cardiovascular diseases in China have kept rising,with no significant reduction in disease burden observed.Percutaneous coronary intervention(PCI)is an effective approach for treating coronary artery disease.Drug-eluting stents and drug-coated balloons are currently the most common PCI devices used in clinical practice.However,challenges with restenosis and late-stage thrombotic events persist.Inhibiting the proliferation of vascular smooth muscle cells while enhancing endothelial cell activity is crucial for reducing restenosis and preventing thrombosis,and it remains a challenge in research.The active compounds and extracts of traditional Chinese medicine(TCM),particularly the combinations of active compounds in coatings,possess multi-target potential and serve as a supplement to coatings prepared from synthetic compounds.This review elucidates the application of TCM active compounds(such as arsenic trioxide,paclitaxel,hirudin,tetramethylpyrazine,emodin,oxymatrine,and curcumin),combinations of TCM active compounds(paclitaxel/hirudin,geniposide/baicalin),and TCM extracts(such as Curcumae Rhizoma extract and Tripterygium hypoglaucum extract)in the coatings for PCI devices in recent years.Furthermore,this review expounds the current challenges and future prospects in this field,giving insights into the innovation of PCI devices.

ObjectiveThis study aimed to evaluate the impact of early rhythm control (ERC) on the occurrence of cardiocerebrovascular events in patients diagnosed with atrial fibrillation detected after stroke (AFDAS).MethodsA systematic search was conducted across nine databases from inception to October 15, 2023 to identify clinical trials comparing ERC with usual care interventions in AFDAS patients. The primary outcome assessed was recurrent stroke, with secondary outcomes including all-cause mortality, adverse events related to arrhythmias, and dementia.ResultsAnalysis of five studies, consisting of two randomized clinical trials (RCTs) involving 490 patients and three cohort studies involving 95,019 patients, revealed a reduced rate of recurrent stroke [odds ratio (OR) = 0.30, 95% confidence interval (CI) 0.11–0.80, P = 0.016 in RCTs; OR = 0.64, 95% CI 0.61–0.68, P < 0.00001 in cohort studies] and all-cause mortality (hazards ratio = 0.94, 95% CI 0.90–0.98, P = 0.005 in cohort studies) in the ERC group compared to the usual care group. In addition, ERC was associated with superior outcomes in terms of dementia.ConclusionsPatients with AFDAS who underwent ERC treatment exhibited a decreased risk of cardiocerebrovascular events compared to those receiving usual care. These results support the potential benefits of implementing an ERC strategy for this specific patient population.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, Identifier [CRD42023465994].

ETHNOPHARMACOLOGICAL RELEVANCE:Chinese herbal medicine (CHM) is widely used for treating coronary heart disease complicated with heart failure (CHD-HF). However, the exact mechanisms involved are still not fully understood. AIM OF THE STUDY:To assess the clinical effectiveness and potential pharmacological mechanisms of CHM for treating CHD-HF. METHODS:Eight databases were retrieved for Randomized Controlled Trials of CHM for CHD-HF published from their inception to March 2023. Quality assessment of include studies was performed by the Cochrane risk-of-bias. Meta-analysis was used to assess the effectiveness of CHM for CHD-HF, and then core drugs and active ingredients were selected by data mining and network pharmacology. Finally, cluster and enrichment analysis were adopted to explore the potential targets and signaling pathways. RESULTS:A total of 52 studies enrolling 5216 patients were included. Meta-analysis revealed that CHM treatment groups significantly improved left ventricular ejection fraction (LVEF), 6-min walk test (6-MWT), left ventricular end-diastolic dimension (LVEDD) and left ventricular end systolic diameter (LVESD) than control groups: [LVEF: SMD = 0.7, 95%CI (0.54, 0.87), p < 0.00001, I2 = 80%; 6-MWT: SMD = 0.72, 95%CI (0.58, 0.86), p < 0.0001, I2 = 67%; LVEDD: SMD = -0.79, 95%CI (-0.89, -0.69), p < 0.0001, I2 = 49%; LVESD: SMD = -0.6 (-0.74, -0.46), p < 0.0001, I2 = 0%]. The results of various biological information analysis showed the internal relationship between prescriptions, core drugs, active ingredients and therapeutic targets. Twelve core herbs with the most commonly use and high correlation were selected from 110 CHMs of 52 prescriptions for CHD-HF treatment, and further 65 effective components were screened out according to the most strength value, which were divided into 12 compounds such as terpenoids, flavonoids, steroids and alkaloids and etc. At the same time, 67 therapeutic targets of active ingredients in CHD-HF were filtrated. On these bases, cluster and enrichment analysis of the components and targets were used to explore relevant pharmacological mechanisms, mainly including anti-myocardial cell damage, anti-inflammation, anti-apoptosis, anti-fibrosis, regulation of oxidative stress, anticoagulation and angiogenesis, and improvement of glucose and fatty acid metabolism. CONCLUSION:CHM are effective in treating CHD-HF compared with conventional treatment. Some of the included studies have high risks in the implementation of blinding, so more high-quality studies are needed. The active ingredients of CHM could protect the myocardium and improve pathological environment of CHD-HF in various ways. And CHM has the advantage of multi-component and multi-target treatment for complex diseases.

Background/aimsTo investigate the specific effects of s odium-glucose transporter 2 inhibitor (SGLT2i) on cardiac energy metabolism.MethodsA systematic literature search was conducted in eight databases. The retrieved studies were screened according to the inclusion and exclusion criteria, and relevant information was extracted according to the purpose of the study. Two researchers independently screened the studies, extracted information, and assessed article quality.ResultsThe results of the 34 included studies (including 10 clinical and 24 animal studies) showed that SGLT2i inhibited cardiac glucose uptake and glycolysis, but promoted fatty acid (FA) metabolism in most disease states. SGLT2i upregulated ketone metabolism, improved the structure and functions of myocardial mitochondria, alleviated oxidative stress of cardiomyocytes in all literatures. SGLT2i increased cardiac glucose oxidation in diabetes mellitus (DM) and cardiac FA metabolism in heart failure (HF). However, the regulatory effects of SGLT2i on cardiac FA metabolism in DM and cardiac glucose oxidation in HF varied with disease types, stages, and intervention duration of SGLT2i.ConclusionSGLT2i improved the efficiency of cardiac energy production by regulating FA, glucose and ketone metabolism, improving mitochondria structure and functions, and decreasing oxidative stress of cardiomyocytes under pathological conditions. Thus, SGLT2i is deemed to exert a benign regulatory effect on cardiac metabolic disorders in various diseases.Systematic review registrationhttps://www.crd.york.ac.uk/, PROSPERO (CRD42023484295).

Aims: The objective of this study was to assess the efficacy and potential mechanisms of Chinese herbal medicine (CHM) for treating coronary heart disease (CHD) patients with anxiety or depression.Methods: A systematic literature search was performed. Screening studies, extracting data, and assessing article quality were carried out independently by two researchers. The active ingredients of CHM for the treatment of CHD with anxiety or depression were analyzed by the network pharmacology, and the main potential mechanisms were summarized by the database of Web of Science.Results: A total of 32 studies were included. The results showed that compared with the blank control groups, CHM was more beneficial in treating anxiety or depression in patients with CHD [anxiety: OR = 3.22, 95% CI (1.94, 5.35), p < 0.00001, I2 = 0%; depression: OR = 3.27, 95% CI (1.67, 6.40), p = 0.0005, I2 = 0%], and the efficacy of CHM was not inferior to that of Western medicine (WM) [anxiety: OR = 1.58, 95%CI (0.39, 6.35), p = 0.52, I2 = 67%; depression: OR = 1.97, 95%CI (0.73, 5.28), p = 0.18, I2 = 33%,]. Additionally, CHM also showed a significant advantage in improving angina stability (AS) in CHD patients with anxiety or depression compared with blank groups [anxiety: SMD = 0.55, 95%CI (0.32, 0.79), p < 0.00001, I2 = 0%; depression: p = 0.004] and WM groups [anxiety: SMD = 1.14, 95%CI (0.80, 1.47), p < 0.00001, I2 = 0%; depression: SMD = 12.15, 95%CI (6.07, 18.23), p < 0.0001, I2 = 0%]. Angina frequency (AF) and electrocardiogram (ECG) analysis after using CHM demonstrated similar trends. Based on the network pharmacology, quercetin, kaempferol, luteolin, beta-sitosterol, puerarin, stigmasterol, isorhamnetin, baicalein, tanshinone IIa, and nobiletin were most closely and simultaneously related to the pathological targets of CHD, anxiety, and depression. The main underlying mechanisms might involve anti-damage/apoptosis, anti-inflammation, antioxidative stress, and maintaining neurotransmitter homeostasis.Conclusion: CHM exhibited an obvious efficacy in treating CHD patients with anxiety or depression, especially for improving the symptom of angina pectoris. The most active compounds of CHM could simultaneously act on the pathological targets of CHD, anxiety, and depression. Multiple effective components and multiple targets were the advantages of CHM compared with WM.

Aims This systematic review aimed to study the hippocampal and frontal changes of heart failure (HF) patients and HF animal models with cognitive impairment or depression. Methods A systematic review of the literature was conducted independently by reviewers using PubMed, Web of Science, Embase, and the Cochrane Library databases. Results and conclusions 30 studies were included, involving 17 pieces of clinical research on HF patients and 13 studies of HF animal models. In HF patients, the hippocampal injuries were shown in the reduction of volume, CBF, glucose metabolism, and gray matter, which were mainly observed in the right hippocampus. The frontal damages were only in reduced gray matter and have no difference between the right and left sides. The included HF animal model studies were generalized and demonstrated the changes in inflammation and apoptosis, synaptic reduction, and neurotransmitter disorders in the hippocampus and frontal lobes. The results of HF animal model studies complemented the clinical observations by providing potential mechanistic explanations of the changes in the hippocampus and frontal lobes.

Aims: The study aimed to evaluate the correlation of different microparticle (MP) phenotypes with plaque burden and their diagnostic value and preliminarily explore the role of MPs in atherosclerosis (AS). Methods: Carotid intima-media thickness (CIMT) and maximal plaque area in 23 patients with carotid atherosclerosis (CAS) and 22 healthy subjects were measured by ultrasound. Transmission electron microscopy, nanoparticle tracking analysis and western blot were used to identify MPs. Flow cytometry assay measured absolute number of MPs, and receiver operating characteristic (ROC) analysis was used to assess the relationship between plaque burden and MPs. To study the preliminary mechanism of MPs in AS, MPs were administered to 32 male Kunming mice, which were randomly divided into control, CAS, healthy, and tetrahydrobiopterin (BH4) groups. Hematoxylin-eosin staining, immunohistochemistry staining, and Western blot were adopted to detect relevant indexes 24 h after the injection. Results: The plasma levels of CD45+ leukocyte-derived microparticle (LMP), CD11a+ LMP, CD11a+/CD45+ LMP, and CD31+/CD42b+ platelet-derived microparticle (PMP) in CAS patients were significantly higher than those in healthy subjects, and were positively correlated with the maximal plaque area. Moreover, the levels of CD11a+ LMP, CD11a+/CD45+ LMP were also positively correlated with CIMT. The area under the ROC curve of the four MPs was 0.689, 0.747, 0.741, and 0.701, respectively. Compared with healthy subjects, MPs from CAS patients resulted in a significantly lower expression of endothelial nitric oxide synthase (eNOS) dimer/monomer, and BH4 could improve eNOS uncoupling. Moreover, the level of VCAM-1 in intima in the CAS group was significantly higher than in the other three groups. Conclusion: CD11a+ LMP and CD11a+/CD45+ LMP might be potential biomarkers for CAS prediction. BH4-related eNOS uncoupling occurs in CAS patients, and circulating MPs from them lead to endothelial dysfunction through eNOS uncoupling.

Atherosclerosis (AS)-related diseases are still the main cause of death in clinical patients. The phenotype switching, proliferation, migration, and secretion of vascular smooth muscle cells (VSMCs) have a pivotal role in atherosclerosis. Although numerous research studies have elucidated the role of VSMCs in AS, their potential functional regulations continue to be explored. The formation of AS involves various cells, such as endothelial cells, smooth muscle cells, and macrophages. Therefore, intercellular communication of blood vessels cannot be ignored due to closely connected endothelia, media, and adventitia. Extracellular vesicles (EVs), as the vectors of cell-to-cell communication, can deliver proteins and nucleic acids of parent cells to the recipient cells. EVs have emerged as being central in intercellular communication and play a vital role in the pathophysiologic mechanisms of AS. This review summarizes the effects of extracellular vesicles (EVs) derived from multiple cells (endothelial cells, macrophages, mesenchymal stem cells, etc.) on VSMCs in AS. The key findings of this review are as follows: 1) endothelial cell–derived EVs (EEVs) have anti- or pro-atherogenic effects on VSMCs; 2) macrophage-derived EVs (MEVs) aggravate the proliferation and migration of VSMCs; 3) mesenchymal stem cells can inhibit VSMCs; and 4) the proliferation and migration of VSMCs can be inhibited by the treatment of EVs with atherosclerosis-protective factors and promoted by noxious stimulants. These results suggested that EVs have the same functional properties as treated parent cells, which might provide vital guidance for treating AS.

摇摆桥墩的损伤和残余位移小,具有良好的震后可恢复性.以预应力双柱式摇摆墩结构体系为研究对象,考虑预应力筋对摇摆刚度的影响,基于拉格朗日方程和动量矩守恒定理给出预应力双柱式摇摆墩的刚体动力分析模型,并进行脉冲型地震动作用下的摇摆谱分析.研究结果表明:在长周期脉冲地震动作用下,预应力筋可以有效减轻低墩的地震反应;随着桥墩高度的增加或地震动频率的增加,预应力筋对桥墩地震反应的影响降低,桥墩依靠自身转动惯量抵抗地震作用;负摇摆刚度既可有效避免桥墩的倒塌,又能减轻脚点处的局部损伤,可在摇摆墩设计时采用.

BACKGROUND:Xue-Fu-Zhu-Yu decoction (XFZYD) is a traditional Chinese prescription that has been used to treat patients with blood stasis in China for many years. The present study aimed to evaluate the improvement of cardiac and endothelial functions of XFZYD for patients with acute coronary syndrome (ACS) through a systematic review and meta-analysis.METHODS:Six databases were searched to collect RCTs related to the treatment of XFZYD for ACS. The primary outcomes were cardiac and endothelial functions, including the levels of left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD) in echocardiography, as well as the changes in the levels of nitric oxide (NO), endothelin-1 (ET-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in the serum. The secondary outcomes were the blood levels of oxidative damage markers (including superoxide dismutase (SOD) and malondialdehyde (MDA)), C-reactive protein (CRP), brain natriuretic peptide (BNP), creatine kinase-MB (CK-MB), and cardiac troponin I (cTnI) as well as the incidence of adverse drug reactions (ADRs). Weighted mean difference (WMD) was estimated for all the outcomes with the random effects model. This type of analysis was conducted in the subgroups of the ACS subtypes, and the methodological quality was assessed using the handbook of Cochrane Collaboration.RESULTS:A total of 1,658 records were identified, and 16 randomized controlled trials (1,171 patients) were included. The primary outcomes suggested that XFZYD combined with routine treatment improved LVEF, reduced LVEDD and LVESD, and also improved the serum levels of NO, and reduced the levels of ET-1 and ICAM-1. XFZYD combination therapy significantly ameliorated the blood levels of SOD, MDA, BNP, CK-MB, and cTnI. However, the results indicated no significant difference between XFZYD plus routine treatment and routine treatment for the levels of VCAM-1 and CRP. Moreover, all the ADRs reported in the included studies were slight and the patients recovered soon.CONCLUSIONS:The present study suggested that XFZYD may improve the cardiac and endothelial functions of ACS patients without serious ADRs. However, based on the mediocre methodological quality, the aforementioned conclusion should be confirmed in a multicenter, large-scale, and accurately designed clinical trial.

Graphical AbstractA systematic review and meta-analysis was performed to investigate the effect of sodium-glucose cotransporter 2 inhibitors for heart failure with preserved ejection fraction.

The aim of this study was to investigate the effect of exercise on extracellular vesicles (EVs) in patients with metabolic dysfunction. The literatures were searched until Apr 28, 2022, and 16 studies that met inclusion criteria were included in this review. The results showed that the concentrations of platelet-derived extracellular vesicles (PEVs) and endothelial cell-derived extracellular vesicles (EEVs) decreased after long-term exercise, especially for CD62E+ EEVs and CD105+ EEVs. Simultaneously, exercise improved the concentration of clinical evaluation indicators of metabolic diseases, and the changes in these indicators were positively correlated with the changes of EEVs and PEVs. The concentration of skeletal muscle-derived extracellular vesicles (SkEVs) increased after a single bout of exercise. The aforementioned results indicated that long-term exercise might improve endothelial function and hypercoagulability in patients with metabolic dysfunction. The changes in concentrations of EVs could assist in assessing effect of exercise on patients with metabolic dysfunction.

This study aimed to explore the relationship between exercise and circulating microparticles (CMPs). PubMed, Web of Science, Embase, and the Cochrane Library databases were searched until August 13, 2020, using the terms "exercise" and "cell-derived microparticles." The Cochrane tool of risk of bias and the Methodological Index for Non-Randomized Studies were used to grade the studies. Twenty-six studies that met criteria were included in this review, including one before-after self-control study, 2 cohort studies, 4 randomized control trials, 5 case-control studies, and 14 descriptive studies. The studies were divided into a single bout and long-term exercise. The types of MPs contained endothelium-derived microparticles (EMPs), leukocyte-derived microparticles (LMPs), platelet-derived microparticles (PMPs), and erythrocyte-derived microparticles (ErMPs). This first systematic review found that the levels of CMPs continued to increase after a single bout of exercise in untrained subjects and were lower in trained subjects. PMPs expressed a transient increase after a single bout of exercise, and the proportion and duration of PMPs increment reduced in long-term exercise. Most studies showed a decline in LMPs in trained subjects after a single bout and long-term exercise, and variable changes were found in EMPs and ErMPs after exercise. A single bout of exercise drives the vessels exposed to high shear stress that promotes the formation of CMPs. However, the decline in CMPs in trained subjects may be attributed to the fact that they have a better ability to adapt to changes in hemodynamics and cellular function during exercise.

Background. Some postmarketing Chinese patent formulas have been widely used to treat atherosclerosis (AS) and play critical roles in Chinese healthcare. However, the usage of these herbs is yet controversial due to unclear effects and lack of understanding of the mechanism of action. With the modernization of traditional Chinese formulas, we are to elucidate the atheroprotective properties of these remedies from successful postmarketing experiments in vivo. Methods. In this systematic review, we critically searched the databases, applied stringent criteria, assessed the methodological quality, and examined the current evidence in vivo. Results. Consequently, 60 studies were included in the present qualitative synthesis. Data on models, high-fat diet, intervention time, outcome measures, efficacy, and mechanisms were collected. Finally, 23 formulas that could alleviate AS were correlated to the amelioration of plaques, improvement of plaque stability, modification of lipid level and lipid metabolism, and the effects of anti-inflammation and antioxidant stress with multiple components and targets. However, the methodological quality was low and incomplete among the included literature. Conclusions. Thus, taken together, the studies on postmarketing Chinese patent formulas would provide a novel approach to improve the treatment of AS, and rigorously designed studies would provide high-quality evidence.

自复位摇摆桥梁的损伤和残余位移小,具有良好的震后可恢复性.文中以自复位摇摆桥梁为研究对象,对不同类型地震动作用下的结构的延性需求谱及其影响因素进行研究.选用FEMA P695推荐的100条典型地震动作为输入,并划分为远场地震动、近场脉冲地震动以及近场无脉冲地震动.研究结果表明,近场脉冲地震动作用下的结构的延性需求最大,设计时需考虑近场脉冲地震动的影响;随着强度折减系数R的增大,结构的延性需求显著增加,设计时不宜采用较高的强度折减系数;增加刚度比α和耗能系数β能在一定周期范围内减小结构的延性需求;阻尼比ξ在0.01～0.05范围内对延性需求的影响基本可以忽略.

为了研究烟煤的自燃特性,利用热重-差热-傅里叶变换红外光谱(TGA-DTA-FTIR)测试了不同烟煤在变升温速率下重量变化、热量变化、气体释放过程.研究表明:烟煤的挥发分越大,其各特征温度越低、放热峰高度越大.采用Coats-Redfern法计算的活化能显示在自燃过程中活化能依次为正值、负值、正值.100℃前活化能为正,而后变为负,当活化能为负时反应不存在能垒,因此应努力在100℃前控制煤自燃.烟煤活化能大小排序与挥发分大小排序相同.由红外光谱分析得到:实验开始便有少量CO2、H2O、CO、CH4放出,随温度升高H2O浓度逐渐增大在100℃前后形成小高峰.300℃左右各气体开始大量生成,500℃前后CO、CO2、CH4浓度达到顶峰.生成气体的浓度:CO2>H2O>CO>CH4,CO2约占生成气体的90％.烟煤生成各气体的浓度排序与挥发分大小排序相同.

To improve seismic performance of double-deck frame bridge system, a novel precast double-deck rocking frame bridge pier system is developed based on ductile and rocking seismic conception design in this paper. In this novel system, the upper columns are allowed to rock between the precast cap beams to form the rocking story, while the lower columns are connected to precast cap beam and footings by grouted splice sleeve to form emulative cast-in-place story. The seismic response of this novel frame bridge pier system is investigated. Nonlinear equations of motion of the system are established following Lagrange's equation and conservation of angular momentum, and the analytical model is used to conduct case study, parametric study and stability analysis. The results show that seismic responses of the lower columns of the proposed structural system are smaller than cast-in-place bridge pier, while it has an opposite trend for upper columns. The effect of deformability of the lower story on the stability of the system is marginal for low-frequency pulses or small column size, while for high-frequency pulses or large column size the deformability jeopardizes the stability of the system.