Rheological and physicochemical characteristics of asphalt mastics incorporating lime kiln dust and dolomite powder as sustainable fillers

The filler-bitumen interaction mechanism is one of the most essential phases for comprehending the asphalt mixture's performance.However,despite numerous studies,in-depth knowledge of filler-bitumen reciprocity at a microscale level is yet to be ascertained.The goal of this research is to gain a better understanding of the fillerbitumen microscale interaction in terms of the synergy and coaction between the physicochemical and rheological performance of mastics due to filler inclusions.The rheological properties of two sustainable mastics,dolomite powder(DP)and lime kiln dust(LKD),together with a neat PEN 60/70 binder,were analysed based on a temperature sweep at elevated temperature conditions.Meanwhile,frequency sweep and multiple stress creep recovery(MSCR)tests were also conducted at pavement serviceability temperature using the dynamic shear rheometer(DSR).Physicochemical tests using a scanning electron microscope(SEM)and energy dispersive X-rays(EDX)were conducted to analyse the impact of parameters such as particle shape,grain size,texture,and chemical compositions.The DSR test results showcased how the incorporation of fillers in asphalt binder considerably improved the performance of the binder in terms of rutting and fatigue.Likewise,its strain and nonrecoverable compliance parameters were substantially reduced at higher filler and binder concentrations.Physical filler attributes of low rigden voids(R.V),high fineness modulus(FM),and high specific surface area(SSA)led to greater interfacial stiffness and elasticity in LKD mastics compared to DP mastics at different loading frequencies and temperature levels.The SEM/EDX results also indicated that the elemental calcium and carbon composition of each filler component,together with its grain morphology,strongly influenced its rheological performance.

Comparative study of surface electromyography of masticatory muscles in patients with different types of bruxism

BACKGROUND Bruxism is a rhythmic masticatory muscle activity that occurs involuntarily in a non-physiologically functional state.There is a lack of research classifying the functional status of masticatory muscles in patients with different mandibular movement types(centric clenching or eccentric grinding)of bruxism.AIM To assess the differences of the masticatory muscle activity in patients with different types of bruxism.METHODS A total of 21 subjects with centric bruxism(CB)and 21 subjects with eccentric bruxism(ECB)were screened from college students according to a questionnaire and their tooth wear features.Sixteen subjects with no bruxism were also recruited.The surface electromyography(EMG)signals of the temporalis anterior(TA)and superficial masseter muscle(MM)were measured in different mandibular positions and during the chewing task.The EMG amplitude and chewing cycle duration parameters were then analyzed.RESULTS The CB group showed fewer muscle maximal motor units,with the MM being more pronounced,a higher proportion of muscle contractions to be recruited for the same load of chewing activity,and a longer chewing cycle.The ECB group showed more TA maximal motor units and higher MM activity on the nonworking side in unilateral chewing.CONCLUSION CB mainly affects the MM,and patients with CB show reduced masticatory muscle contraction efficiency and chewing cycle efficiency.ECB mainly affects the TA,and patients with ECB show enhanced contraction of non-functional lateral muscle bundles.

Evaluation of gum mastic(Pistacia lentiscus) as a microencapsulating and matrix forming material for sustained drug release

In this study, a natural gum mastic was evaluated as a microencapsulating and matrixforming material for sustained drug release. Mastic was characterized for its physicochemical properties. Microparticles were prepared by oil-in-oil solvent evaporation method. Matrix tablets were prepared by wet and melt granulation techniques. Diclofenac sodium(DFS) and diltiazem hydrochloride(DLTZ) were used as model drugs. Mastic produced discrete and spherical microspheres with DLTZ and microcapsules with DFS. Particle size and drug loading of microparticles was in the range of 22–62 μm and 50–87%, respectively. Increase in mastic:drug ratio increased microparticle size, improved drug loading and decreased the drug release rate. Microparticles with gum: drug ratio of 2:1 could sustain DLTZ release up to 12 h and released 57% DFS in 12 h. Mastic produced tablets with acceptable pharmacotechnical properties. A 30% w/w of mastic in tablet could sustain DLTZ release for 5 h from wet granulation,and DFS release for 8 h and 11 h from wet and melt granulation, respectively. Results revealed that a natural gum mastic can be used successfully to formulate matrix tablets and microparticles for sustained drug release.

Discrete Element Simulation of Asphalt Mastics Based on Burgers Model

In order to investigate the viscoelastic performance of asphalt mastics, a micro-mechanical model for asphalt mastics was built by applying Burgers model to discrete element simulation and constructing Burgers contact model. Then the numerical simulation of creep tests was conducted, and results from the simulation were compared with the analytical solution for Burgers model. The comparision showed that the two results agreed well with each other, suggesting that discrete element model based on Burgers model could be employed in the numerical simulation for asphalt mastics.

Rheological Behavior of Basalt Fiber Reinforced Asphalt Mastic

The characters of basalt fiber are analyzed and compared with commonly used fibers. The rheological behaviors of the basalt fiber reinforced asphalt mastic are investigated by the dynamic shear rheological tests and the repeated creep tests. The results show that basalt fiber has excellent reinforced performances, such as high asphalt absorption ratio, low water absorption ratio, high tensile strength, high elastic modulus and high temperature stability. The rutting factor of the fiber reinforced asphalt mastic is higher than the plain asphalt mastic and the reinforced effects are more remarkable under high temperature. The rheological performances of the asphalt mastic demonstrate a good linear relationship between different temperature and loading frequency. The creep stiffness modulus of the asphalt mastic at different loading time can be expressed by power function. Improved Burgers model is used to represent the rheological behaviors of the asphalt mastic with basalt fiber and the model parameters are estimated.

Chemical Composition of the Essential Oil of Mastic Gum and their Antibacterial Activity Against Drug-Resistant Helicobacter pylori

Mastic gum is derived from the tree named Pistacia lentiscus that is grown only in Island Hios of Greek.Since Mastic was first reported to kill Helicobacter pylori(H.pylori)in 1998,there has been no further study to elucidate which component of mastic specifically shows the antimicrobial activity against H.pylori.In this study,we examined which component of mastic gum was responsible for anti-H.pylori activity.We prepared the essential oil of mastic gum and identified 20 constituents by GC–MS analysis.Ten standard components were assayed for anti-H.pylori activity,and it clarified that a-terpineol and(E)-methyl isoeugenol showed the anti-H.pylori activity against four different H.pylori strains that were established from patients with gastritis,gastric ulcer and gastric cancer.These components could be useful to overcome the drug-resistance H.pylori growth in stomach.

Effects of Chios mastic gum on cardiometabolic risk factors

Chios mastic gum(CMG),the resin produced by the trunk of Pistachia lentiscus var Chia,has been used for culinary and medicinal purposes since antiquity.Despite the fact that Pistacia species are widely distributed throughout the Mediterranean basin and in the circum-Mediterranean regions,CMG is a distinctive resin of the mastic trees grown exclusively in the southern part of the island of Chios.CMG has been used for centuries as a spice,a cosmetic,but its most important usage has been as a strong phytotherapeutic therapy,primarily for the management of gastrointestinal diseases.Recently,there are studies demonstrating that CMG has hypolipidemic,cardioprotective and antidiabetic properties.Therefore,the aim of the present review is to summarize the existing literature data regarding the potential beneficial effects of CMG on cardiometabolic risk factors.

Relevance of a standard food model in combination with electronic jaw movement recording on human mastication pattern analysis

The aim of this paper is to describe the possibilities of analyzing human mastication. The development of a standardized food model is presented. Based on the findings of a systematic literature search an elastic food model was created with the aim of standardizing size and elastic properties. Three different eatable jellied products were chosen, created by a changing of the amount of gelatin (260 Blooms) related to the total mass of the standard jellied food. The different hardness were classified in soft, medium and hard, flavored identically, but stained with different colors: soft-green, medium-yellow, hard-red. A cylindrical form was chosen with a height of 1 cm and a diameter of 2 cm. A standard protocol for analyzing chewing patterns in men was created. The condylographic data off several patients are described in details to demonstrate the possible clinical implementation. The newly developed standard food model (SFM) showed the capability to serve in experimental settings to analyze human mastication, although only a few patients have been examined. In addition, strength and size of the newly developed SFM load the masticatory system in an extent;it should be possible to disclose subclinical symptoms of patients within a short time of examination. The diagnostic procedure of temporo-mandibular disorder (TMD) should be endorsed by this new method. The condylographic data created by a standardized protocol should have the ability to enhance the clinical functional analysis of patients previous to restorative dental procedures.

Nontraumatic Myositis Ossificans in a Muscle of Mastication

Myositis ossificans (MO) is an extraskeletal tumor-like lesion with bone formation, and is relatively rare in the head and neck region. We report herein a clinicopathological analysis of MO associated with a muscle of mastication. The patient was a 70-year-old Japanese woman who presented with a tumorous mass in the right parotid area and no history of trauma. The surgically excised tumorous lesion consisted of proliferating fibroblastic cells with no atypia in the central portion, and a formation of trabecular osteoid and/or bony tissue in the peripheral portion as the so-called “zonal phenomenon”. The final histological diagnosis was MO, and the lesion was located in the posterior belly of the digastric muscle on computer tomography. A review of the literature showed that many cases of MO predominantly affected the medial pterygoid and masseter muscle and showed a history of previous trauma. The present case represents a rare case of nontraumatic MO in the uncommon location of the posterior belly of the digastric muscle.

The Effect of Partial Removable Denture Use on Oral Health Related Quality of Life and Masticatory Function, after 5 Years Use

The aim of this study was to evaluate whether partial removable denture use indeed leads to improved oral health related quality of life and masticatory function. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics Service in the Hospital Affiliated to Kinshasa University (Democratic Republic of Congo) were assessed for enrolment in this study. After applying exclusion criteria, 378 patients were included in the study, and randomly assigned into 2 groups. Oral health related quality of life (OHIP-23) and mastication time (MaT), number of chewing cycles (MaC), mastication frequency (MaF), and the sizes of the peanut fragments (FraS) were compared in both groups. Statistical significance was set at p < 0.05. Results: The average MaC, MaT, MaF, and FraS were 119 (± SD 53.70), 86.75 (±SD 35.35), 1.38 (±SD 0.25), and 3.3 (±SD 3.25) for the denture group and 77.9 (±SD 23.9), 60.2 (±SD 17.91), 1.29 (±SD 0.15), and 1.5 (±SD 0.7) for the non-denture group, respectively. Conclusion: The overall oral health related quality of life was best in the non-denture than denture.

Stabilizing Effects of Ethanolic Extract of Mastic Gum on Microtubule Polymers:an In Vitro Study

Terpenoids are novel natural products isolated from mastic gum.Mastic gum was obtained from the Pistacia Lentiscus tree.Scientific investigations have documented medical and pharmacological properties of mastic gum such as memory enhancement,antifungal,and antibacterial activities.It was astonishing to study the possible interaction of mastic gum extract with microtubule proteins which are involved in memory and consciousness since the administration of mastic gum is evidenced in the improvement of brain functions.Since a number of studies have demonstrated the effect of microtubule dynamics on mammals'memory,in this study,we investigated the effect of Oxygenated Sesquiterpenes(OST)on microtubule polymerization in vitro.OST was purified from the ethanolic extract of mastic gum.The results revealed that OST induces microtubule polymerization;however,microtubule depolymerization was not affected and fluorometric assays showed conformational changes of tubulin in the presence of OST.We interestingly found that colchicine was unable to inhibit MT assembly in the presence of OST and OST was solely more efficient than the combination of OST with paclitaxel for elevating microtubule polymerization rate.We hope that OST could be a promising agent for memory enhancement and the treatment of neurodegenerative diseases as a novel tubulin-binding compound.

Application of the Bayesian Statistical Approach to Develop a Stone Mastic Asphalt(SMA)Pavement Performance Model

Stone mastic asphalt(SMA)has not been widely used in the pavement industry,and there are no detailed design specifications for this type of asphalt.Therefore,long-term behavior properties of this pavement type are not accessible widely,and no model has been established for SMA regarding its performance.The main purpose of this study was to incorporate expert experience(using the Markov-chain process)and data from field experiments to propose a model for SMA performance using the Bayesian approach.The implementation of these sources resulted in a well-organized method to develop a performance model for SMA pavements,which did not have a long-term data.Finally,a linear performance model was established to calculate the SMA service life.The service life of SMA can be predicted explicitly according to the developed performance model which has been validated using a new set of data.

Alterations in the function of circulating mononuclear cells derived from patients with Crohn’s disease treated with mastic

AIM: To assess the effects of mastic administration on cytokine production of circulating mononuclear cells of patients with active Crohn's disease (CD). METHODS: The study was conducted in patients with established mildly to moderately active CD, attending the outpatient clinics of the hospital, and in healthy controls. Recruited to a 4 wk treatment with mastic caps (6 caps/d, 0.37 g/cap) were 10 patients and 8 controls, all of who successfully completed the protocol. Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1), macrophage migration inhibitory factor (MIF) and intracellular antioxidant glutathione (GSH) were evaluated in peripheral blood mononuclear cells (PBMC) before and after treatment. RESULTS: Treating CD patients with mastic resulted in the reduction of TNF-α secretion (2.1 ± 0.9 ng/mL vs 0.5 ± 0.4 ng/mL, P = 0.028). MIF release was signif icantly increased (1.2 ± 0.4 ng/mL vs 2.5 ± 0.7 ng/mL, P = 0.026) meaning that random migration and chemotaxis of monocytes/macrophages was inhibited. No signifi cant changes were observed in IL-6, MCP-1 and GSH concentrations. CONCLUSION: This study shows that mastic acts as an immunomodulator on PBMC, acting as a TNF-α inhibitor and a MIF stimulator. Although further double-blind, placebo-controlled studies in a large number of patients is required to clarify the role of this natural product, this f inding provides strong evidence that mastic might be an important regulator of immunity in CD.

Chios mastic treatment of patients with active Crohn's disease

AIM: To evaluate the effectiveness of mastic administra-tion on the clinical course and plasma inflammatory me-diators of patients with active Crohn’s disease (CD).METHODS: This pilot study was conducted in patients with established mild to moderately active CD, attend-ing the outpatient clinics of the hospital, and in healthy controls. Ten patients and 8 controls were recruited for a 4-wk treatment with mastic caps (6 caps/d, 0.37 g/cap). All patients successfully completed the protocol. CD Ac-tivity Index (CDAI), Nutritional Risk Index (NRI), C-re-active protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1), and total antioxidant potential (TAP) were evaluated in the plasma at baseline and at the end of the treatment period. Results were expressed as mean values ± SE and P < 0.05 was considered to indicate statistical significance.RESULTS: Patients exhibited significant reduction of CDAI (222.9 ± 18.7 vs 136.3 ± 12.3, P = 0.05) as com-pared to pretreament values. Plasma IL-6 was signifi-cantly decreased (21.2 ± 9.3 pg/mL vs 7.2 ± 2.8 pg/ mL, P = 0.027), and so did CRP (40.3 ± 13.1 mg/mL vs 19.7 ± 5.5, P = 0.028). TAP was significantly increased (0.15 ± 0.09 vs 0.57 ± 0.15 mmol/L uric acid, P = 0.036). No patient or control exhibited any kind of side effects. CONCLUSION: The results suggest that mastic signifi-cantly decreased the activity index and the plasma levels of IL-6 and CRP in patients with mildly to moderately ac-tive CD. Further double-blind, placebo-controlled studies in a larger number of patients are required to clarify the role of this natural product in the treatment of patients with CD.

Visco-elastoplastic damage constitutive model for compressed asphalt mastic

In order to describe the three-stage creep behavior of compressed asphalt mastic, a visco-elastoplastic damage constitutive model is proposed in this work. The model parameters are treated as quadratic polynomial functions with respect to stress and temperature. A series of uniaxial compressive creep experiments are performed at various stress and temperature conditions in order to determine these parameter functions, and then the proposed model is validated by comparison between the predictions and experiments at the other loading conditions. It is shown that very small permanent deformation at low stress and temperature increases rapidly with elevated stress or temperature and the damage may initiate in the stationary stage but mainly develops in the accelerated stage. Compared with the visco-elastoplastic models without damage, the predictions from the proposed model is in better agreement with the experiments, and can better capture the rate-dependency in creep responses of asphalt mastic especially below its softening point of 47 °C.

Ability of rotary compactor in compacting consistent slabs and effect of rotary compaction on engineering properties of stone mastic asphalt mixtures

A new automatic rotary compactor and its abilities in compacting stone mastic asphalt(SMA) are presented. Following an overview of the rotary compactor and the compaction procedure, it is demonstrated that the rotary compactor is able to produce uniform slabs with the desired thickness of 65 mm all over around. Furthermore, 132 cored samples from the rotary compactor had been compacted uniformly with approximately 4% optimum air void content. In addition, performance tests results indicate that the rotary compactor produces asphalt mixtures with the requirements of resilient modulus, Marshall stability and flow. A weight factor was introduced for each fraction of aggregates in the degradation analysis to compensate the crushing effect of aggregates during mixing and compacting.

不同熟化方式下甘薯咀嚼加工及食团特性的比较分析

为探究不同熟化方式下甘薯的咀嚼加工行为及食团特性,该研究考察了熟化方式对甘薯的质构、淀粉含量及淀粉短程有序性的影响,并进行咀嚼试验,跟踪分析受试者咀嚼至吞咽点食团的水分含量、咀嚼参数、唾液分泌情况、食团特性以及淀粉消化情况。结果表明:倒蒸甘薯条和煮甘薯干片的硬度、弹性、胶粘性、内聚性、咀嚼性和回复性均显著高于其他4种熟化甘薯制品(P<0.05),熟化甘薯制品中淀粉含量及淀粉短程有序性均显著低于鲜甘薯(P<0.05)。在不同熟化方式甘薯制品的咀嚼试验中,咀嚼参数中的一口量、咀嚼次数、咀嚼时间、进食速率存在显著差异(P<0.05);回收食团的平均中值粒径(D50)(1.55~2.65 mm)与样品硬度、胶粘性和咀嚼性呈显著正相关(P<0.05);样品形态以及受试者主观性的差异使样品咀嚼时的平均唾液添加量(0.41~0.94g/g干基)和平均唾液流速(45.92~72.65mg/s)存在显著差异(P<0.05);咀嚼后的平均总淀粉消化率最高为蒸制甘薯(88.35%),最低为微波甘薯(34.32%)。该研究为深入研究甘薯消化特性以及甘薯精深加工奠定理论基础。

植物茎秆纤维结构及其沥青胶浆流变特性

本研究将棉秸秆、玉米秸秆、废竹、蔗渣制备出植物纤维。采用相关分析和试验评价各植物纤维沥青胶浆的物化特性。结果表明:在微米级结构层面上,棉秸秆纤维、玉米秸秆纤维和蔗渣纤维呈现出空腔管状结构,竹纤维、木质素纤维为实心结构;各纤维的化学成分存在差异,且影响其热解速率。掺入纤维后,沥青胶浆高温稳定性改善明显,在初始试验温度下各纤维沥青胶浆车辙因子提升了23.8%~75.7%,弹性恢复率提高了9.4%~18.5%。掺加纤维后,沥青胶浆低温抗裂性能略有下降,但植物纤维类型对其影响并不显著。

不同咀嚼压力对大鼠正畸移动牙压力侧牙槽骨改建的影响

目的 研究不同咀嚼压力对大鼠正畸移动牙压力侧牙槽骨改建的影响。方法 选取8周龄雄性SD大鼠45只,按随机数字表法分为基线组5只、软食组20只和硬食组20只。基线组大鼠在实验初始处死、取材。软食组和硬食组建立上颌右侧第一磨牙近中移动模型,左侧不加力作为对照。各组喂以相应饮食,分别于加力后第3、5、7、14天各处死5只大鼠,取双侧上颌骨。Micro CT测量加力磨牙近中移动距离及压力侧牙槽骨骨体积/组织体积(BV/TV)、骨小梁分离度(Tb.Sp)和骨小梁厚度(Tb.Th)。抗酒石酸酸性磷酸酶(TRAP)染色计数破骨细胞数量;原位杂交染色观察细胞核因子-κB受体活化因子配体(RANKL)和骨保护素(OPG)mRNA表达随时间变化情况。结果 第14天时软食加力组牙齿移动距离小于硬食加力组(P<0.05)。软食加力组与硬食加力组压力侧牙槽骨BV/TV、Tb.Sp、Tb.Th差异无统计学意义。细胞计数和原位杂交结果显示,在第5、7天,软食加力组的破骨细胞数量和RANKL/OPG比值均低于硬食加力组(P<0.05)。结论 较小的咀嚼压力会减低大鼠正畸牙压力侧牙槽骨中的破骨活动,减小牙齿移动距离。