Effect of Dietary Resistant Starch on Prevention and Treatment of Obesity-related Diseases and Its Possible Mechanisms

Overweight or obesity has become a serious public health problem in the world, scientists are concentrating their efforts on exploring novel ways to treat obesity. Nowadays, the availabilities of bariatric surgery and pharmacotherapy have enhanced obesity treatment, but it should has support from diet, physical exercise and lifestyle modification, especially the functional food. Resistant starch, an indigestible starch, has been studied for years for its beneficial effects on regulating blood glucose level and lipid metabolism. The aim of this review is to summarize the effect of resistant starch on weight loss and the possible mechanisms. According to numerous previous studies it could be concluded that resistant starch can reduce fat accumulation, enhance insulin sensitivity, regulate blood glucose level and lipid metabolism. Recent investigations have focused on the possible associations between resistant starch and incretins as well as gut microbiota. Resistant starch seems to be a promising dietary fiber for the prevention or treatment of obesity and its related diseases.

Study on asymmetric thermo-physical effect mechanism of intermediate frequency DC resistance spot welding for aluminum alloy

The asymmetric thermo-physical mechanism of the resistance spot welding technique with intermediate frequency(2 kHz)and direct current(RSWIFDC)on the high strength aluminum(Al)alloy TL091 was studied here in view of the Peltier effect.On the basis of the analysis of the electrode cap surface erosion state and the shape-position of the nugget,it was concluded that asymmetric thermo-physical phenomenon occurred on both ends of the nugget,and even had an influence upon the shape-forming coefficient and the vertical position deviation of the nugget,and the erosion degree of the electrode caps.In this work,the relative thermo-physical model of the welding was established combined with the Peltier effect and the spot welding characteristics.Accordingly the relative welding phenomena,such as nugget center deviation and different erosion degree of the electrode cap surface,was explained clearly using the model related with the Peltier effect for the first time.This model provides important theoretical basis for future study and application of Al alloy spot welding,based on which,effective works may be done to promote the quality of the Al alloy welded joints and to obtain favorable control upon parameters of Al alloy welding for electrode caps.

The mechanism underlying overwintering death in poplar:the cumulative effect of effective freeze-thaw damage

We analyzed the relationships linking overwintering death and frost cracking to temperature and sunlight as well as the effects of low temperatures and freeze–thaw cycles on bud-burst rates,relative electrical conductivity,and phloem and cambial ultrastructures of poplar.Overwintering death rates of poplar were not correlated with negative accumulated temperature or winter minimum temperature.Freeze–thaw cycles caused more bud damage than constant exposure to low temperatures.Resistance to freeze–thaw cycles differed among clones,and the budburst rate decreased with increasing exposure to freeze–thaw cycles.Cold-resistant clones had the lowest relative electrical conductivity.Chloroplasts exhibited the fastest and the most obvious reaction to freeze–thaw damage,whereas a single freeze–thaw cycle caused little damage to cambium ultrastructure.Several such cycles resulted in damage to plasma membranes,severe damage to organelles,dehydration of cells and cell death.We conclude that overwintering death of poplar is mainly attributed to the accumulation of effective freeze–thaw damage beyond the limits of freeze–thaw resistance.

BanXiaXieXin decoction treating gastritis mice with drug-resistant Helicobacter pylori and its mechanism

BACKGROUND Helicobacter pylori(H.pylori)is the main pathogen that causes a variety of upper digestive diseases.The drug resistance rate of H.pylori is increasingly higher,and the eradication rate is increasingly lower.The antimicrobial resistance of H.pylori is an urgent global problem.It has been confirmed that Banxia Xiexin decoction(BXXXT)demonstrates the effects of treating gastrointestinal diseases,inhibiting H.pylori and protecting gastric mucosa.The purpose of the present study is to further explore the therapeutic effects of BXXXT on drug-resistant H.pylori.AIM To confirm that BXXXT demonstrates therapeutical effects in vivo and in vitro on gastritis mice with drug-resistant H.pylori and explain its mechanism to provide an experimental basis for promoting the application of BXXXT.METHODS The aqueous extract of BXXXT was gained by water decocting method.The inhibitory effect of the aqueous extract on H.pylori was detected by dilution in vitro;drug-resistant H.pylori cells were used to build an acute gastritis model in vivo.Thereafter,the model mice were treated with the aqueous extract of BXXXT.The amount of H.pylori colonization,the repair of gastric mucosal damage,changes of inflammatory factors,apoptosis,etc.,were assessed.In terms of mechanism exploration,the main medicinal compositions of BXXXT aqueous extract and the synergistic bacteriostatic effects they had demonstrated were analyzed using mass spectrometry;the immune function of peripheral blood cells such as CD3+T and CD4+T of mice with gastritis before and after treatment with BXXXT aqueous extract was detected using a flow cytometry;the H.pylori transcriptome and proteome after treatment with BXXXT aqueous extract were detected.Differently expressed genes were screened and verification was performed thereon with knockout expression.RESULTS The minimum inhibitory concentration of BXXXT aqueous extract against H.pylori was 256-512μg/mL.A dose of 28 mg/kg BXXXT aqueous extract treatment produced better therapeutical effects than the standard triple therapy did;the BXXXT aqueous extract have at least 11 ingredients inhibiting H.pylori,including berberine,quercetin,baicalin,luteolin,gallic acid,rosmarinic acid,aloe emodin,etc.,of which berberine,aloe emodin,luteolin and gallic acid have a synergistic effect;BXXXT aqueous extract was found to stimulate the expressions of CD3+T and CD4+T and increase the number of CD4+T/CD8+T in gastritis mice;the detection of transcriptome and proteome,quantitative polymerase chain reaction,Western blotting and knockout verification revealed that the main targets of BXXXT aqueous extract are CFAs related to urea enzymes,and CagA,VacA,etc.CONCLUSION BXXXT aqueous extract could demonstrate good therapeutic effects on drug-resistance H.pylori in vitro and in vivo and its mechanism comes down to the synergistic or additional antibacterial effects of berberine,emodin and luteolin,the main components of the extract;the extract could activate the immune function and enhance bactericidal effects;BXXXT aqueous extract,with main targets of BXXXT aqueous extract related to urease,virulence factors,etc.,could reduce the urease and virulence of H.pylori,weaken its colonization,and reduce its inflammatory damage to the gastric mucosa.

Mechanical behavior of electric resistance welded pipes in pipe-making process

The changes in the mechanical behavior of electric resistance welded（ERW） pipes before and after the cage roll forming process were investigated through tensile experiments. It is found that the Bauschinger effect does not exist in the pipe product, while the work hardening effect introduced by pipe-making is the direct cause of the mechanical changes. The prestrain introduced during different pipe-making processes are accumulative to the work hardening effect. And the increment of the yield strength for making Ф 244.48 × 8.94 pipe is approximately 45 MPa, higher than that of hot-rolled plates. It is verified that the strain ε=t/D-t is an efficient index representing the work hardening effect from the engineering viewpoint.

A dissolution-diffusion sliding model for soft rock grains with hydro-mechanical effect

The deformation and failure of soft rock affected by hydro-mechanical（HM） effect are one of the most concerns in geotechnical engineering, which are basically attributed to the grain sliding of soft rock. This study tried to develop a dissolution-diffusion sliding model for the typical red bed soft rock in South China. Based on hydration film, mineral dissolution and diffusion theory, and geochemical thermodynamics, a dissolution-diffusion sliding model with the HM effect was established to account for the sliding rate. Combined with the digital image processing technology, the relationship between the grain size of soft rock and the amplitude of sliding surface was presented. An equation for the strain rate of soft rocks under steady state was also derived. The reliability of the dissolution-diffusion sliding model was verified by triaxial creep tests on the soft rock with the HM coupling effect and by the relationship between the inversion average disjoining pressure and the average thickness of the hydration film. The results showed that the sliding rate of the soft rock grains was affected significantly by the waviness of sliding surface, the shear stress, and the average thickness of hydration film. The average grain size is essential for controlling the steady-state creep rate of soft rock. This study provides a new idea for investigating the deformation and failure of soft rock with the HM effect.

Surface Modification of Parts Material Shape Memory TiNiCo with a View to Providing a Functional and Mechanical Property as a Factor in Resource

The paper presents a complex method of forming the surface-modified layers of materials with shape memory effect, including high-speed flame spraying of powders based on TiNiCo;subsequent thermal and thermomechanical treatment allows the formation of surface layers of nano-sized state that have a high level of functional, mechanical and performance properties;it is shown that the complex processing with a layer of TiNiCo allows a reduction of the porosity of the coatings and increases the strength of the coating’s adhesion to the substrate. It is found that, after treatment with high-speed flame spraying powder shape memory TiNiCo, steel has an increase in cycle life by 30% - 40% in a cycle fatigue and 3 - 3.5 times durability. Based on comprehensive research into the metallophysical surface-modified layer, new information is obtained about the nanoscale composition.

Mechanism and application of mechanical property improvements in engineering materials by pulsed magnetic treatment:A review

Pulsed magnetic treatment(PMT)has been adopted as an effective strengthening method for engineering materials and components in recent years,and the development of its application depends on the comprehensive understanding of the nature of PMT.The deep mechanism was thought initially to be the magnetostrictive effect,while further investigation found that the magnetic field could lead to the change of the defect states in the crystal,which is called the magnetoplastic effect.Due to the complexity of the engineering materials,manifestations of the magnetoplastic effect become more diverse,and they were reviewed in the form of microstructure homogenization and interfacial stabilization.Further,the mechanism of the magnetoplastic effect was discussed,focusing on the changes in the spin states under the external magnetic field.Microstructure modifications could also alter material performances,especially the residual stress,plasticity,and fatigue properties.Therefore,PMT with specific parameters can be utilized to obtain an ideal combination of microstructure,residual stress,and mechanical properties for better service performance of different mechanical parts,and its applications on machining tools and bearings are perfect examples.This work reviews the effect of PMT on the microstructure and properties of different materials and the mechanism,and it also summarizes the fundamental applications of PMT on essential mechanical parts.

A novel route to enhance high-temperature mechanical property and thermal shock resistance of low-carbon Mgo-C bricks by introducing ZrSiO_(4)

Conventional MgO-C bricks(graphite content>14 wt.%)produce a great deal of greenhouse gas emission,while low-carbon MgO-C bricks have serious thermal shock resistance during high-temperature service.To enhance the high-temperature mechanical property and thermal shock resistance of low-carbon MgO-C bricks,a novel route of introducing ZrSiO_(4) powder into low-carbon MgO-C bricks was reported in such refractories with 2 wt.% flaky graphite.The results indicate that the low-carbon MgO-C brick with 0.5 wt.%ZrSiO_(4) addition has the maximum hot modulus of rupture at 1400℃ and the corresponding specimen fired in the carbon embedded atmosphere has the maximum residual strength ratio(98.6%)after three thermal shock cycles.It is found that some needle-like AlON and plate-like Al_(2)O_(3)-ZrO_(2) composites were in situ formed in the matrices after the low-carbon MgO-C bricks were coked at 1400℃,which can enhance the high-temperature mechanical property and thermal shock resistance due to the effect of fiber toughening and particle toughening.Moreover,CO_(2) emission of the newly developed low-carbon MgO-C bricks is reduced by 58.3% per ton steel after using them as the working lining of a 90 t vacuum oxygen decarburization ladle.

Key issues in rock mechanics of the Three Gorges Project in China

The Three Gorges Project is one of the essential key projects for flood controlling and water resources regulation in the Yangtze River. The project includes a river-crossing dam, underground powerhouses, and navigation structures. Because of the huge size and complicated construction technologies, the project faced a series of challenging engineering issues. In terms of rock mechanics, there are many key technical issues, including the sliding resistance and stability of the dam section along the foundations of powerhouses No.l-5, the ,,;lope stability of the double-line five-stage shiplock, excavation of large-scale underground powerhouses, and curtain grouting under the dam. With decades of scientific research and 16 years of practical construction experiences and reservoir operations, these key technical issues in construction of the Three Gorges Project are successfully resolved, which will attribute to the development of hydropower technology. On the basis of the monitoring data during construction and normal operation periods of the Three Gorges Project, this paper presents a systematic analysis of these key rock mechanical issues in terms of behaviors, solutions, dynamic controlling, monitoring arrangement and integrated assessment.

A Constitutive Model of Elasto-Plastic Materials Based on Fibre-Reinforcing and Sliding Mechanisms

Without use of any plastic potential function, an incremental constitutive relation of elastoplastic material is formulated by relating energy-consumlng rate in sliding between micro grain constituents of material and in extending-shrinklng of fiber-like ones to overall strain rate and deriving the stress response with a work-conjugate method. Slip systems and fibers deforming compatibly with overall strain are used as equivalent energyconsumers distributed uniformly in the same direction as the replaced micro objects. The equivalent energy-consumers with similar orientation are treated as an elasto-plastic component with only one deformation degree of freedom, so the incremental stiffness tensor is explicit and convenient for numerical analysis. The effect of loading paths on macro mechanical behavior of material under complex loading conditions can be simulated because the combined responses of components with different orientations are sensitive to loading history.We have also investigated how to determine parameters in the force-response functions of the equivalent energy-consumers and coefficients for cross-hardenlng effect and Bauschinger effect on the basis of conventional material tests. Examples are given to show that the predicted macro elasto-plastic behavior and subsequent yield surfaces of materials under various loading conditions are in excellent agreement with experiments.

Study of Blended Antistatic PET Filament

From the effects of the composition of the three kinds ofblended systems, the antistatic agent content and theblending methods on the spinnability, the antistatic prop-erty, and the wash fastness of PET filament, it is foundthat the antistatic behavior of the (PET) - (PEG) -(SDBS) - stearate quaternary system is improved greatlydue to the synergefic effect of the combined antistaticagents and the volume resistivity of the fiber made.Thereof reaches 10~8 ～ 10~9Ω·cm after being washed 20 tines in saponaceous water at 40℃. Its spinnability anddrawing behavior are good. The effect of the antistaticagent content on the mechanical property of PET fila-ment is also studied.

Oscillating Mechanical Stimulation of the Craniocervical Region as Physical Therapy for Chronic Migraine: A Pilot Trial

Objective: We conducted a prospective trial of oscillating mechanical stimulation (OS) of the craniocervical region as treatment for drug-refractory chronic migraine (CM). Methods: Ten patients (8 women, 2 men;mean age 47.0 ±15.1 years) were enrolled. The treatment was administered over an 8-week period to 13, 4, and 9 sites on the face and head, neck, and upper back, respectively, at 5- to 15-pound intensity. The primary outcome measure was the number of days patients suffered a migraine (hereafter “number of migraine days”), and the secondary outcome measures were the six-item Headache Impact Test (HIT-6) and Visual Analog Scale (VAS) scores for migraine pain intensity and the nine-item Patient Health Questionnaire (PHQ-9) and the seven-item Generalized Anxiety Disorder (GAD-7) scale scores. Results: Nine patients completed treatment. The number of migraine days remained unchanged, from a mean 21.7 ±11.6 days/month before treatment to 19.3 ±7.3 days/month upon completion of treatment. However, the HIT-6 scores improved from 67.0 ±8.2 to 61.4 ±7.1 (p = 0.007) after 3 weeks, 61.1 ±11.5 (p = 0.01) after 6 weeks, and 59.9 ±11.6 (p = 0.035) upon completion of treatment. Similarly, the VAS scores improved significantly from 7.3 ±1.7 to 5.7 ±3.1 (p = 0.018) at 6 weeks and 4.8 ±2.8 (p = 0.011) upon completion of treatment. The GAD-7, PHQ-9, and allodynia scale scores remained unchanged. Conclusion: Our data suggest that OS is well tolerated and may become a feasible form of treatment for drug-resistant CM.

聚组训练研究前沿:结构类型、训练效应与作用机理

聚组训练作为抗阻训练的一种新型组织方式,已引起理论与实践界深入关注,但有关聚组训练的结构类型、理论基础、与传统抗阻训练的效果差异及其作用机理等都有待开展深入细致的研究。现有研究表明:聚组训练主要包括组内间歇结构、重复间休息式结构、组间休息重分配结构、休息暂停结构和等比休息结构5种;不论是在急性还是长期训练效应上,与传统抗阻训练相比,其在爆发力、肌肉力量、肌肉耐力和动作速度保持等方面的积极效应相对明显;其效应机理主要与聚组训练结构方式所导致的能量消耗与恢复过程变化、神经—肌肉疲劳与恢复效果改变,练习过程中动作机械性能的改善以及主观疲劳感明显下降等有直接关系。

蜂窝梁柱子结构抗连续性倒塌性能研究

目的研究蜂窝梁柱子结构的抗连续性倒塌性能,为工程应用提供设计依据。方法基于拆除构件法,应用ABAQUS有限元分析软件建立蜂窝梁柱子结构与实腹梁柱子结构模拟模型,研究在中柱失效作用下的结构性能,分析孔型、开孔率和首孔距离等参数对蜂窝梁柱子结构抗连续性倒塌性能的影响。结果蜂窝梁柱子结构相比于实腹梁柱子结构的峰值承载力增长64.26%,所对应的位移增长73.57%;蜂窝梁良好的成铰机制使悬链线效应发展更充分;孔型、开孔率、首孔距离对其破坏模式、峰值荷载、悬链线效应发展程度均具有一定影响。结论蜂窝梁柱子结构具有良好的抗连续性倒塌能力,孔型宜为圆形或六边形,开孔率宜取40%~60%,首孔距离宜取0.75~1.0倍梁截面高度。

砂土边坡桩间水平土拱机理与演变规律离散元分析

抗滑桩等非连续支挡结构在边坡工程中依靠土拱效应安全经济地发挥支护功能。鉴于不同类型砂土的力学性质差异较大,为揭示密砂与松砂土质边坡抗滑桩桩间水平土拱机理与演变规律,采用离散元方法(DEM)模拟支挡砂土水平土拱的成拱过程。在传统力链分析的基础上,提出通过筛选高应力颗粒来研究土拱的形成过程,进一步从细观角度对不同工况土拱效应进行分析,以揭示“应力拱”和“位移拱”的演化过程。研究表明:密砂和松砂中的水平土拱的动态演变过程均表现为3个演化阶段,分别对应于密砂和松砂的剪切性状,即应变软化和应变硬化现象,揭示了砂土边坡桩间土拱效应的演变规律。此外,讨论了宏-微观DEM模拟参数对土拱形成过程与土拱效应性能的影响,结果表明拱跨对于荷载传递效率的影响最大。

绿原酸抗菌作用及机制的研究进展

绿原酸是植物体在有氧呼吸过程中经莽草酸途径合成的一种苯丙素类物质,自然存在于多种中药材和食物中,杜仲、金银花和咖啡等植物中含量较高,具有抗菌、抗炎、抗氧化、抗癌和免疫调节等多种药理活性。近年来,绿原酸作为研究活性物质的焦点之一,因其抗菌谱广,对多种细菌和真菌均有较好的抗菌活性,故绿原酸对临床菌株的抗菌作用逐渐被重视和研究。本文综述了近年来国内外关于绿原酸对多种致病菌的抗菌作用及机制的研究进展,旨在为绿原酸抗菌作用的深入研究提供参考,为临床抗感染治疗和控制带来新思路,有助于绿原酸在医药领域的开发。

生物可降解塑料PLA的改性研究进展

介绍了聚乳酸(PLA)材料的性能特点,包括良好的降解性、相容性、易加工、机械强度高、无毒无刺激性;综述了国内外对PLA改性的研究现状,主要包括对PLA的物理改性(共混改性、填充改性、增强改性)和化学改性;并对该材料的应用进行了讨论。

天然植物薰衣草精油对多重耐药鲍曼不动杆菌的抗菌作用及机制研究

目的探讨天然植物薰衣草精油对多重耐药鲍曼不动杆菌的抗菌作用及初步机制。方法用微量稀释法测定薰衣草精油对多重耐药鲍曼不动杆菌的最低抑菌浓度和最低杀菌浓度;用杀菌动力学研究进一步确定其起效和维持时间;用小鼠感染模型评价薰衣草精油对创口愈合的促进作用;用结晶紫染色定量测定法对其生物膜的抑制和清除作用进行研究;用激光共聚焦显微镜观察生物膜中细菌存活情况;用核酸蛋白测定仪器检测3 mg/mL、6 mg/mL薰衣草精油干预后的细菌DNA核酸和蛋白质泄漏量;用钾离子试剂盒测定钾离子泄漏量,并采用蛋白组学技术结合生物信息学研究方法,初步探究薰衣草精油抗多重耐药鲍曼不动杆菌的作用机制。结果薰衣草精油的最低抑菌浓度和最低杀菌浓度均为6 mg/mL,在120 min时,该浓度可杀死几乎所有多重耐药鲍曼不动杆菌,且呈现明显的剂量依赖效应和时间依赖效应。整体动物模型评价表明,3 mg/mL和6 mg/mL薰衣草精油均能促进创口愈合,疗效明显。进一步研究发现,3 mg/mL薰衣草精油具有一定的多重耐药鲍曼不动杆菌生物膜抑制作用,且能显著增加DNA核酸和蛋白质的泄漏量,并能促进钾离子外流。同时,6 mg/mL薰衣草精油展现了对多重耐药鲍曼不动杆菌生物膜的清除作用。蛋白组学研究提示,薰衣草精油的抗菌作用可能与影响多重耐药鲍曼不动杆菌的氧化还原酶活性和细胞代谢过程,干扰细胞壁/膜/包膜等结构的生物合成有关。结论薰衣草精油在3 mg/mL时即可发挥对多重耐药鲍曼不动杆菌的抗菌作用,其作用机制可能与破坏细菌生物膜和干扰细菌代谢有关。

原位生长的CNTs@MoS_(2)杂化物增强水性膨胀型防火涂料的耐火和隔热性能

目的设计并研制一种耐火和隔热性能突出的水性膨胀型防火涂料。方法以碳纳米管(CNTs)、四水合钼酸铵、十六烷基溴化铵(CTAB)、硫脲为原料,通过简单的一步水热法原位生长出一种新型的CNTs@MoS_(2)杂化物,并采用FT-IR、XRD、拉曼光谱、SEM等手段对复合杂化物进行表征。再将CNTs@MoS_(2)杂化物作为增效剂分散在水性膨胀型防火涂料(CNTs@MoS_(2)/WES)中,通过大板实验和涂层、炭焦层表面分析评价了涂层的耐火和隔热性能。结果与WES(膨胀倍率为3.90)、CNTs/WES涂层(膨胀倍率为6.04)、MoS_(2)/WES涂层(膨胀倍率为4.59)相比,CNTs@MoS_(2)/WES涂层具有最高的膨胀倍率(8.88)。CNTs@MoS_(2)/WES涂层所涂覆的钢板在燃烧40min后背面温度最低(133.3℃),这充分表明该涂层具有优异的隔热性能。结论制备的CNTs@MoS_(2)杂化物表现出稳定的网络交织结构,有效提高了它在涂料中的分散性能。此外,CNTs@MoS_(2)/WES涂层优异的耐火和隔热性能主要归因于:1)CNTs@MoS_(2)/WES涂层及其炭焦层具有更致密和完整的表面,阻隔了热量的传递;2)CNTs的添加增强了炭焦层的致密性,抑制了膨胀过程中产生的气体泄漏,提升了涂层膨胀倍率;3)MoS_(2)提高了膨胀层强度且促进了炭焦层的形成,减少了裂纹和孔隙的产生。