Natural rubber is produced by a rubber transferase (a cis-prenyltransferase). Rubber transferase uses allylic pyrophosphate to initiate the rubber molecule and isopentenyl pyrophosphate (IPP) to form the polymer. Rubber biosynthesis also requires a divalent metal cation. Understanding how molecular weight is regulated is important because high molecular weight is required for high quality rubbe...

Most patients with hemorrhoids experience only mild symptoms that can be treated with nonprescription topical preparations. Patients usually seek treatment when symptoms increase. Internal hemorrhoids typically present with prolapse or painless rectal bleeding. External hemorrhoids also bleed and can cause acute pain if thrombosed. Medical therapy should be initiated with stool softeners plus l...

the purpose of this research was to evaluate the recovery potential of solid waste in mashhad. the solid waste generated in the regions 4, 5 and 6 has been quantified and characterized using direct weighing, physical testing and truckload sampling methods. to determine the quantity and quality of waste generated and its seasonal variations, chemical and physical analysis were carried out for on...

Rubber-like materials exhibit stress softening when subject to loading–unloading cycles, i.e., the Mullins effect. However, this phenomenon can be recovered after annealing previously stretched sample under a stress-free state. The aim of paper is establish constitutive model with thermodynamic consistency account for and thermal recovery. Towards goal, (i) an explicit form Helmholtz free energ...

Rubber biosynthesis takes place on the surface of rubber particles. These particles are surrounded by a monolayer membrane in which the rubber transferase is anchored. In order to gain better insight into whether rubber particles from different plant species share common structural characteristics, the micromorphology of rubber particles from Ficus carica, Ficus benghalensis, and Hevea brasilie...

The effectiveness of sodium hypochlorite (NaOCl) (2.5%) or iodine (10%) for decontamination of the operation field (tooth, rubber dam, and gasket [Oraseal]) was compared by using bacterial cultivation. In addition, the final samples were also assessed for bacteria by using polymerase chain reaction. Teeth (n = 63) receiving root canal treatment were polished with pumice, isolated with rubber da...

The biosynthesis of rubber is thought to take place on the surface of rubber particles in laticifers, highly specialized cells that are present in more than 40 plant families. The small rubber particle protein (SRPP) has been supposed to be involved in rubber biosynthesis, and recently five SRPPs (TbSRPP1-5) were identified in the rubber-producing dandelion species Taraxacum brevicorniculatum. ...

In the presented work, sulfur concrete and rubber were used for producing functionally graded materials (FGM). The physical and mechanical properties of sulfur concrete and rubber were changed continuously across the thickness. On one side, there was just rubber and, on the other, there was pure sulfur; the properties of each substance were moved to reach another. This kind of material was cons...

Studies on the properties and applications of rubber cement-based materials are well documented. The sizes of rubbers used in these materials varied. However, information about the effects of rubber size on the properties of rubber cement-based materials, especially pore structure, mechanical strengths, and drying shrinkage properties, remains limited. Three groups of rubber with major particle...

In recent years, various studies have been undertaken on how to use waste materials in civil engineering projects. Among waste materials, waste rubber has been highlighted to be used for different purposes such as reinforcing of soil and making of reinforced slopes. To investigate the properties of granulated rubber-soil mixture and its application in making of slopes behind retaining walls, so...