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Micro-nano rubber asphalt was prepared by high-temperature and high-speed shearing with micro-nano degraded rubber powder as raw material, and the micromorphology of micro-nano degraded rubber powder and miscible process of micro-nano rubber rubber and substrate asphalt were investigated by scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectrometer, and the road performance of micro-nano rubber asphalt mixture including water stability, temperature stability and cracking failure resistance were studied by the design of asphalt aggregate ratio. In addition, the application effect of micro-nano rubber asphalt mixture in practical road engineering was further evaluated. The results showed that mass fraction of sol in degraded rubber in which the size of dissociated carbon black was about 200 nm reached 65.7%, and the interaction of sulfur cross-linked bond between degraded rubber and asphalt appeared during the miscible process; the micro-nano rubber asphalt mixture showed excellent water stability, high- and low-temperature stability and cracking failure resistance; the key technical indexes of the upper layer and the lower layer in full-depth rubber asphalt pavement of test section of Jiuquan-Jiayuguan ring expressway prepared by using micro-nano rubber asphalt mixture in Gansu province all complied with the specifications and design requirements.

High- content rubber asphalt （HCRA) was prepared by using highly devulcanized rubber （DR), the effects of maleic anhydride （MAH) pre-grafted devulcanized rubber （DR) modification and direct blending modification of MAH and DR on the structure and properties of HCRA were comparatively studied by attenuated total reflection Fourier transform infrared spectrometer, gel permeation chromatography, dynamic shear rheometer and dynamic mechanical analyzer, and the modification mechanisms of two modification methods were explored. The results showed that during the pre-grafting of MAH onto DR, the free radical substitution reaction with active sites provided by olefin double bonds and allyl hydrocarbon atoms occurred, while when MAH and DR were directly blended with asphalt, there were two reactions: free radical substitution reaction and esterification, the latter being the main one. The sol components of MAH-modified HCRA were mainly composed of low and medium molecular weight components. The MAH improved significantly the high- and low-temperature rheological properties of HCRA. In addition, both the modification methods had an impact on the structure and properties of HCRA, and there were significant differences with the change of addition amount of MAH.

The reclamation law of natural rubber reinforced with silica （SNR) swollen by a small amount of soybean oil at different temperatures and in different time was studied, and the chemical composition and micromorphology of the reclaimed pro-ducts were determined. The results showed that within the temperature range of 160 and 240 ℃, the sol content of SNR increased continuously with the increasing temperature after swollen by soybean oil of 20 phr （mass), and when reclaimed at 220 ℃ for 15 min, the mass fraction of sol in the reclaimed product increased to 50.5%, and the mass fraction of sol in the reclaimed product was only 28.7% at 200 ℃, which indicated that 220 ℃ was an important turning point temperature in the reclamation process of SNR. The increase in oxygen content in the reclaimed product was due to the violent oxidation reaction of SNR during the reclamation process. In addition, as the degree of reclamation increased, the thickness of bound rubber of loose strata on the surface of silica decreased from 25 nm to 8 nm, indicating that thermal-oxidative reclamation could achieve a high degree of detachment between nano silica and its surface bound rubber.

Asphalt was separated into 4 components, saturated, aromatic, resin and asphaltene, according to its polarity. The effect of the 4 components on the vulcanization process and vulcanization effect of cis-1,4-polybutadiene rubber (BR) were investigated. The results showed that the saturated and aromatic components in asphalt could prolong the scorch time of BR and improve the processing safety. Resin and asphaltene could effectively increase the maximum torque of compound and accelerate the curing rate. Asphalt prolonged the scorch time and accelerated the curing rate of the BR compound, but it could slightly reduce the maximum torque. The oxygen, nitrogen, and sulfur functional groups which were rich in resins and asphaltenes could effectively participate in the vulcanization reaction of BR.

The aerobic regeneration of waste tire rubber powder was carried out in a tubular furnace, and the effects of atmosphere, regeneration temperature and regeneration time on the aerobic regeneration process of waste tire rubber powder were investigated. The results showed that the mass loss and mass fraction of sol of rubber powder increased with the increasing temperature under aerobic conditions. The secondary recombination and re-crosslinking reaction occurred in the molecular chains of synthetic rubber, while the main chain of natural rubber was mainly broken. When the rubber powder was treated under aerobic conditions for 10 min at 240 ℃, the mass fraction of sol reached 55.9%. The fracture of rubber main chain and cross-link bond was mainly broken by oxidation reaction. The aerobic reclamation of waste rubber generated the compounds containing carbonyl and sulfoxide groups, accompanying the formation of water and carbon dioxide. These phenomena indicated that the rubber molecular chain in rubber powder was effectively broken by oxidative reaction.

The content of ground tire rubber was limited by its multiple cross-linking networks. High-content ground tire rubber modified asphalt （mass fraction of ground tire rubber more than 30%） binder could be produced by addition of degraded tire rubbers （DR）, which was controllably prepared by reactive screw extrusion using ground tire rubber. The effects of degradation degree and content of DR on structure and properties of DR modified asphalt were analyzed by Soxhlet extraction, Mooney visco-sity, basic physical properties, infrared spectroscopy, and optical microscopic tests. The results showed that chemical bonds broke, and cross-linking network of ground tire rubber collapsed during degradation process. Compared with conventional ground tire rubber modified asphalt binder, DR modified asphalt binder had finer dispersion, lower viscosity and better stability at high temperature. The addition of DR with high degree of degradation increased by a large margin the content of ground tire rubber, leading to further improved deformation ability at low temperature and deformation resistance at high temperature. The steep increased of viscosity at certain rubber content should be noticed.

The original bottle-neck of difficulty in processing, inconsistent performances and pollution during processing of crumb rubber modified asphalt （CRMA） were summarized and analyzed from chemical engineering perspective， the source， composition and basic properties of crumb rubber were analysized， the relationship between the perpetually changing multi-networks structure and properties of crumb rubber during selection， breaking or activization， asphalt binder or mixture processing and recycle were elucidated with 69 references. The performance and optimization methods of CRMA mixture were also reviewed from engineering perspective. The development direction of CRMA was prospected and development suggestions were put forward.

The truck tire rubber powder was reclaimed through a single screw extruder and then reclaimed rubber with different reclaiming degrees was obtained. After being blended with natural rubber/cis-1,4-polubutadiene rubber to replace all the sof-teners and part of the carbon black in the traditional typical sidewall formula, its influences on the structure and performance of sidewall rubber were also discussed. The results showed that as the reclaiming degree increased, the sol content of reclaimed rubber increased, and the gel particles of reclaimed rubber evolved from tens of microns to micro-nano scale. Moreover, the vulcanization efficiency of the blend increased significantly with better aging resistance and flexing fatigue resistance which was more than ten times that of the traditional reclaimed rubber. It was expected to be used in the preparation of high-performance sidewall rubber.

The thermal oxidative degradation behavior and process of vulcanized styrene-butadiene rubber (SBR) at high temperature was studied by the sol-gel analysis, equilibrium swelling method, Fourier transform infrared spectroscopy coupled with mass spectrometry (FTIR-MS) and in-situ Fourier transform infrared spectroscopy.The chemical structure changes of degradation process of the SBR vulcanizate at 210 ℃ were compared with those of 150 ℃.The results showed that the sol content of the SBR vulcanizate at 210 ℃ gradually increased in the initial stage of the reaction, reached a maximum value of 28.1% at 10 min, and then a significant decline occurred.The trend of the reaction at 150 ℃ was similar to that at 210 ℃, but the reaction rate was relatively slower.The vulcanized SBR produced a small amount of sulfur dioxide gas at 7 min and a relatively large amount of other oxidation products containing carboxyl group and thioheterocyclic group at 12 min were observed by FTIR-MS.The cross-linking bonds of the vulcanized SBR were initially converted from polysulfur bonds to monosulfur bonds, part of which were then oxidized to sulfoxide groups and further to sulfonyl groups or sulfates.The backbone oxidation of the SBR vulcanizate was an autocatalytic oxidation, and the carbonyl group content remained stable during the late stage of oxidation.

Objective To investigate the effect of circular RNA 0038467 (circ_0038467) targeting at miR-182 on apoptosis and endoplasmic reticulum stress of alveolar epithelial cell line(HPAEpiC) induced by S. pneumoniae (Sp). Methods HPAEpiC cells were divided into control (NC) group (without any treatment), Sp group (Sp infection), Sp+si-NC group (Sp infection after transfection by si-NC), Sp+si-circ_0038467 group (Sp infection after transfection by si-circ_0038467), Sp+miR-NC group (Sp infection after transfection of miR-NC), and Sp+miR-182 group (Sp infection after transfection of miR-182 mimics), Sp+si-circ_0038467+anti-miR-NC group (Sp infection after transfection by si-circ_0038467 and anti-miR-NC), Sp+si-circ_0038467+anti-miR-182 group (Sp infection after transfection by si-circ_0038467 and anti-miR-182). The expressions of circ_0038467 and miR-182 were detected by RT-qPCR. Flow cytometry detected cell apoptosis; Western blot analyzed the expression level of B-cell lymphoma (Bcl-2), heavy chain binding protein (BIP), Bcl associated X protein (Bax) and CCAAT enhancer binding protein homologous protein (CHOP), cysteine protease 3 (caspase-3), and cleaved-caspase-3 proteins. The effects of circ_0038467 and miR-182 expression on HPAEpiC cell apoptosis and endoplasmic reticulum stress induced by S. pneumoniae were analyzed. Results The apoptosis rate of HPAEpiC cells, the expression of circ_0038467, Bax, caspase-3, cleaved-caspase-3, BIP and CHOP were significantly increased after Sp infection (P＜0.05), whereas the expression of Bcl-2 was significantly decreased(P＜0.05). After circ_0038467 inhibition or miR-182 over-expression, the apoptosis rate, expression of circ_0038467, Bax, caspase-3, cleaved-caspase-3, BIP and CHOP were significantly reduced (P＜0.05), whereas Bcl-2 expression was significantly increased(P＜0.05). miR-182 inhibition can attenuate the effect of circ_0038467 inhibition on Sp induced HPAEpiC apoptosis and endoplasmic reticulum stress (P＜0.05). Conclusions Inhibition of circ_0038467 can attenuate Sp induced alveolar epithelial cell apoptosis and endoplasmic reticulum stress, and its mechanism is related to the targeted regulation of miR-182 expression.

The recycled rubber with low Mooney viscosity was prepared from waste tire rubber powder by shear method and micro oxygen method and was used in tire tread rubber. The effects of the type and amount of recycled rubber on the curing characteristics, physical and mechanical properties, aging resistance and microstructure of tread rubber were investigated. The results showed that compared with the traditional reclaimed rubber, the positive curing time of the mixture with low Mooney viscosity reclaimed rubber was shortened, the Payne effect was weakened, and the Shore A hardness, 100% and 300% constant tensile stress, tensile strength and aging resistance were slightly improved. The loss factor of vulcanizates decreased at 60 ℃, also decreased slightly at 0 ℃. The reclaimed rubber with low Mooney viscosity had good dispersion in the matrix. The thermal stability and solvent extraction resistance of the vulcanizates prepared by micro oxygen method were better than those prepared by shear method and traditional reclaimed rubber.

In order to solve the problem that shallow water source wells in northern pastoral areas are prone to freezing in winter, which brings inconvenience to drinking water for local residents. shallow water source wells are taken as the research object. Through field experiments indoor and software simulations, the key factors to prevent freezing of water source wells are discovered by obtained temperature distribution pattern of water source wells,A photovoltaic heating system compatible with existing solar water extraction systems in pastoral areas is designed. It is found that the temperature distribution of water source wells is “steep-slow- slow” in the field and extreme conditions. The steep-rising areas are located at 0.0-1.3m, 0.0-0.8m away from the wellhead, and the temperature rising rates in the steep-rising areas are 10.58 C/m and 15.75 C/m, respectively. Increasing the temperature of “steep rise zone” is very important to improve the water surface temperature of water source wells. The ANSYS software was used to simulate the temperature field of the water source well under extreme conditions (-40℃), and compared with the indoor simulation results to verify its accuracy. A photovoltaic heating system compatible with the existing solar water lifting system in the pastoral area was designed which can generate 1659.52J heat a day larger than 412.2J heat dissipation per day under extreme conditions which is calculated by software model. Theoretically this system can meet antifreeze requirements. An indoor anti-freezing experiment of solar heating for a freezing period (3 months) was carried out. It was found that the temperature at the water surface of the water source well was about 0℃, which verified the feasibility of the solar heating system.

The article discusses the link between periodontitis and rheumatoid arthritis (RA) and asks if regular periodontal treatment is needed for RA patients. It explains how periodontal pathogens can worsen RA and suggests that periodontal therapy, especially non-surgical treatment, can improve symptoms in patients with both conditions. It recommend regular periodontal care for RA patients to manage inflammation and counteract the effects of periodontal pathogens.

Cryptocaryon irritans, one of the most devastating holotrichous ciliated protozoans, causes massive economic losses in the pompano, Trachinotus ovatus, mariculture industries. Considering the many advantages of phytochemicals, such as low cost, low residuals, and low pollution, they can be a good alternative for the prevention and control of C. irritans infestations. In this study, 14 phytochemicals were evaluated for their antiparasitic activity against the theront of C. irritans, and nine showed significant antiparasitic activity. Nerolidol was the most promising compound, causing 100% mortality of theronts with 30‐min exposure at a concentration of 10.0 μl/L. The half‐maximal inhibitory concentrations (IC50s) of nerolidol on C. irritans theronts, protomonts, and tomonts were 2.1, 13.3, and 7.1 μl/L, respectively. Abnormal morphologies of the theronts, trophonts, and tomonts were observed after exposure to 10.0, 30.0, and 10.0 μl/L nerolidol solution for 15 min, 30 min, and 480 min, respectively. A diet supplemented with 2.3 ml/kg of nerolidol reduced the number of trophonts on the gills of pompano by 95.7% decrease compared with the control groups and the theront chemotaxis to pompano mucus and sera, while increased the survival rate of infected pompanos by 24.44%, and had no significant effect on pompano hindgut and serum myeloperoxidase. These results suggest that nerolidol is a new potential drug for controlling fish cryptocaryonosis. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation is one of the most promising emerging technologies for environmental pollution control. However, the preparation of efficient, low-cost photocatalysts still faces many challenges. TiO2 is a widely available and inexpensive photocatalyst material, but improving its catalytic degradation performance has posed a significant challenge due to its shortcomings, such as the easy recombination of its photogenerated electron–hole pairs and its difficulty in absorbing visible light. The construction of homogeneous heterojunctions is an effective means to enhance the photocatalytic performances of photocatalysts. In this study, a TiO2(B)/TiO2(A) homogeneous heterojunction composite photocatalyst (with B and A denoting bronze and anatase phases, respectively) was successfully constructed in situ. Although the construction of homogeneous heterojunctions did not improve the light absorption performance of the material, its photocatalytic degradation performance was substantially enhanced. This was due to the suppression of the recombination of photogenerated electron–hole pairs and the enhancement of the carrier mobility. The photocatalytic ability of the TiO2(B)/TiO2(A) homogeneous heterojunction composite photocatalyst was up to three times higher than that of raw TiO2 (pure anatase TiO2). [ABSTRACT FROM AUTHOR]