Rational design yields molecular insights on leaf binding of the anchor peptide Macaque Histatin

In times of a constantly growing world population and increasing demand for food, sustainable agriculture is crucial. To reduce the amount of applied nutrients, herbicides, and fungicides, the rainfastness of plant protection agents is of pivotal importance. As a result of protective agent wash-off, plant protection is lost, and soils and groundwater are severely polluted. To date, rainfastness of plant protection products is achieved by adding polymeric adjuvants to the agrochemicals. However, polymeric adjuvants will be regarded as microplastics in the future, and environmentally friendly alternatives are needed. Anchor peptides (APs) are promising biobased and biodegradable adhesion promoters. While the adhesion of anchor peptides to artificial surfaces, such as polymers, has already been investigated in theory and experimentally, exploiting the adhesion to biological surfaces remains challenging. The complex nature and composition of biological surfaces such as plant leaf and fruit surfaces complicate the generation of accurate models. Here, we present the first detailed three-layered atomistic model of the surface of apple leaves and use it to compute free energy profiles of the adhesion and desorption of APs to and from that surface. Our model is validated by a novel fluorescence-based MTP assay that mimicks these complex processes and allows quantifying them. For the AP Macaque Histatin, we demonstrate that aromatic and positively charged amino acids are essential for binding to the waxy apple leaf surface. The established protocols should generally be applicable for tailoring the binding properties of APs to biological interfaces.

Effectiveness of the iDOP-PH adhesion promoter in relation to adhesion of the pavement bitumen

Asphalt pavement is permanently influenced by various environmental conditions and traffic load. Because of this after a certain period numerous defects may appear on the surface of the road pavement. These defects include peeling, chipping, pots, cracks etc. The low water proof resistance of the asphalt concrete (conditioned by low adhesion of the bitumen to aggregate surface) is considered to be one of the reasons for appearance of these defects. Adhesion promoters’ use is the most common method to increase adhesion activity of pavement bitumen. Goal. The objective of the current research work is the evaluation of influence of the domestic adhesion promoter iDOP on the conventional and adhesion properties of bitumen. Methodology. To achieve this goal, the following was done: the effect of the adhesive promoter iDOP on the standard quality indicators of bitumen was determined according the requirements of the current standards DSTY 4044 and SOU 45.2-00018112-067; the effect of the adhesive promoter on the adhesion of bitumen to the glass surface (according to the DSTU B.V.2.7-81 method) and to the surface of aggregates with different mineralogy was evaluated by the rotating bottle method according to DSTU EN 12697-11; the thermal stability of the iDOP-PH promoter was tested by simulating the technological ageing of bitumen according to the method given in GOST 18180 and the RTFOT method. Results. Grounding on the experimental data obtained, it was found that the adhesive promoter iDOP-PH does not affect the standard indicators of the quality of bitumen (penetration, softening and breaking point temperatures, ductility). During hardening with the RTFOT method, a slight inhibitory effect of the promoter is observed, which appears as an increase in the values of residual penetration and ductility compared to bitumen without promoter. The iDOP-PH promoter increases the adhesive capacity of bitumen, which is confirmed by the adhesion data determined by the improved method given in GOST B.V.2.7-81 and the rolling bottle method. Originality. It is shown that the iDOP-PH promoter has a relevantly low thermal stability. With this the main factor affecting the decrease in thermal stability is the long time exposing of the binder at high temperature by GOST B.V.2.7-81 method. Practical value. It is shown that the promoter concentrations recommended by the supplier are insufficient, and to ensure the required values of the adhesion (standardized in СОУ 45.2-00018112-067) it is advisable to increase the concentration of the iDOP-PH promoter in bitumen to 0.3 - 0.6%.

Retracted “Serum amyloid P down-regulates CCL-1 expression, and inhibits Ras/MAPK signaling and development of breast cancer”

This article previously published in Volume 17 Issue 16 of this journal in September 2017 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE,http://publicationethics.org/ resources/guidelines). Retraction: Ding S, Li H, Li X, Wang W, Du X, Dong G, Zhang P. Serum amyloid P down-regulates CCL-1 expression, and inhibits Ras/MAPK signaling and development of breast cancer. Trop J Pharm Res 2017; 16(9):2089-2095 doi: http://dx.doi.org/10.4314/tjpr.v16i9.7 To the editor: The figures in the paper were plagiarized partly from an earlier published article, Qi et al, P-selectinmediated tablet adhesion promoters tumor growth. Oncotarget 2015;30:6(9):6584–6596, and data from a master's thesis submitted by Bin Li under the supervision of Professor Lijing Wang and Professor Cuiling Qi. Sincerely, Cuiling Qi and Lijing Wang.

Spicy Bitumen: Curcumin Effects on the Rheological and Adhesion Properties of Asphalt

Over the years, the need for the synthesis of biodegradable materials has facilitated the drift of the asphalt industry towards eco-sustainable and cost-effective production of road pavements. The principal additives in the asphalt industry to improve the performance of road pavements and increase its lifespan are majorly rheological modifiers, adhesion promoters and anti-oxidant agents. Rheological modifiers increase physico-chemical properties such as transition temperature of asphalt binder (bitumen), adhesion promoters increase the affinity between binder and stone aggregates while anti-oxidant agents reduce the effects of oxidation caused by exposure to air, water and other natural elements during the production of asphalt pavements. In this study, we tested the effectiveness of a food grade bio-additive on these three aforementioned properties. We also sought to hypothesize the mechanisms by which the additive confers these desired features on bitumen. We present this study to evaluate the effects of turmeric, a food-based additive, on bitumen. The study was conducted through dynamic shear rheology (DSR), atomic force microscopy, scanning electron microscopy (SEM) and boiling test analysis.

Synthesis and study of polyfunctional silicon-containing amines as adhesion promoters of epoxyamine compounds

At present, in order to obtain high-tech hybrid products, high demands are placed on modern adhesives for creating durable joints between dissimilar materials. It is known that adhesion depends on the compatibility of the adhesives with the surfaces of the materials. For epoxy compositions, amine compounds are the main hardeners. In this regard, in the presented work, silicon-containing amines were synthesized based on polyfunctional aminoalkoxysiloxanes for epoxy compositions, the strength of attachment of which to various metal substrates was studied using these adhesion promoters. Aminoalkoxysiloxanes were prepared by reacting 3-aminopropyltriethoxysilane with monoethanolamine in nitrogen at atmospheric pressure in the presence of a binary antioxidant and catalytic amounts of an alkali metal alcoholate. To carry out the reaction in a homogeneous phase, the reaction mixture was heated to a temperature of 100-110 °C and distilled off to 90% of ethanol from the theoretically calculated amount. Further, the reaction was carried out at a reduced temperature of 10-20 millimeter of mercury pressure until the release of alcohol stops. At the same time, gravimetric control was carried out and the refractive index of the reaction mixture was measured. As a result, aminoalkoxysilanes were obtained in the form of light-yellow oily liquids. The structure of the obtained compounds was investigated by IR-spectroscopy on a Fourier spectrophotometer FSM-1202 and 1H NMR-spectroscopy on a high-resolution BrukerWM-250 NMR-spectrometer. It was found that under the selected synthesis conditions, aminopropyl-tri-(2-aminoethoxy)silane is obtained with the highest yield of 97.6% at a molar ratio of 3-aminopropyltriethoxysilane (AGM-9) with monoethanolamine 1: 3. The obtained compounds were used in the composition of epoxy compounds in order to improve their physical and mechanical properties. The adhesion properties of epoxy compositions based on ED-22 epoxy resin and isophorone diamine were studied using synthesized polyfunctional aminoalkoxysiloxanes as adhesion promoters. It was found that the most effective adhesion promoter is aminopropyl-tri-(2-aminoethoxy) silane.

Research of the properties of rubber-cord composites in the presence of new adhesion promoters

Studies of experimental adhesion modifiers based on a mixture of fatty acids from the production of light vegetable oils. The properties of rubber compounds and their vulcanizates obtained using experimental adhesion promoters KK with cobalt content from 7.5 to 16.5% are investigated. The plastic-elastic and vulcanization properties of the properties of breaker rubber compounds based on polyisoprene, the physical and mechanical properties of breaker rubbers and the bond strength in the “rubber-brass-plated steel cord system” were studied. When testing belt rubbers containing experienced adhesion promoters or an imported analog of Manobond 680C, the following features were revealed. The plasticity of the prototypes was in the range of 0.2-0.4. This indicates satisfactory processing properties. The Mooney viscosity of the prototypes was lower than that of the production sample. The use of experienced adhesion promoters instead of the analogue (Manobond 680C) increases the resistance to scorching. On the basis of the analysis of elastic-strength properties, it was found that in terms of the conditional tensile strength, the prototypes were inferior to the serial ones. However, rubbers containing the KK-12, KK-13.5, KK-15 promoters met the control standards. The tensile elongation at break of the experimental rubbers is higher than that of the serial sample. This may indicate the formation of a more uniform cure network in the presence of the test products. When testing rubber-metal-hard composites, it was noted that, under normal conditions, the experienced adhesion promoters have advantages over Manobond 680C. However, at elevated temperatures, under conditions of salt and steam-air aging, they are slightly inferior to Manobond 680C. It has been established that the experimental adhesion promoters provide the required set of technical properties of belt rubbers with a CO2 + content of 12–16.5% wt. Thus, it is possible to recommend the adhesion promoters KK 12, KK-13.5, KK 15 for practical use in the composition of belt rubber compounds. This will allow replacing a foreign-made product and reducing the cost of production.

Research of Structure and Properties of Rubber Mixtures with Adhesion Additives on the Basis of Carbamide

The effect of new adhesion promoters on the bond strength of rubber compounds with rubber cord based on synthetic isoprene rubber SKI-3, as well as on the structure of their vulcanizates, is investigated. The synthesized additives were taken as adhesion promoters: 2,4-diphenylcarbamidotoluene (DPKT); 2-isocyanatophenylcarbamidotoluene (IPCT) and the industrial promoter is Manobond 680C. Tests were conducted to determine the adhesion strength to the metal cord and the density of the cross-linking of the obtained rubber compounds by the dosage of additives. It is determined that the maximum value of adhesion had mixture containing 1.2 parts by weight of 2-isocyanato-phenylcarbamidotoluene and Manobond 680C. It was found that the introduction of additives DPCT and IPCT leads to the formation of additional cross-links in the vulcanizates. Rubbers containing additives in an amount of 0.4-1.2 parts by weight have the highest density of crosslinking. The studies made it possible to hypothesize the relationship between the particle size and the electrokinetic potential of blocked urea-based isocyanates with the strength of brass-metal cord-rubber bonding. The results obtained indicate that the greater the electrokinetic potential of the synthesized additives and the lower the average particle size, the better the additive is distributed in the rubber compound and affects the formation of the adhesive layer at the brass-metal cord-rubber interface.