Genetic diversity strategy for the management and use of rubber genetic resources: more than 1,000 wild and cultivated accessions in a 100-genotype core collection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Natural rubber latex coated with calcium phosphate for biomedical application

Natural rubber latex (NRL) is a flexible biomembrane that possesses angiogenic properties and has recently been used for guided bone regeneration, enhancing healing without fibrous tissue, allergies or rejection. Calcium phosphate (Ca/P) ceramics have chemical, biological, and mechanical properties similar to mineral phase of bone, and ability to bond to the host tissue, although it can disperse from where it is applied. Therefore, to create a composite that could enhance the properties of both materials, NRL biomembranes were coated with Ca/P. NRL biomembranes were soaked in 1.5 times concentrated SBF solution for seven days, avoiding the use of high temperatures. SEM showed that Ca/P has been coated in NRL biomembrane, XRD showed low crystallinity and FTIR showed that is the carbonated type B. Furthermore, hemolysis of erythrocytes, quantified spectrophotometrically using materials (Ca/P, NRL, and NRL + Ca/P) showed no hemolytic effects up to 0.125 mg/mL (compounds and mixtures), indicating no detectable disturbance of the red blood cell membranes. The results show that the biomimetic is an appropriate method to coat NRL with Ca/P without using high temperatures, aiming a new biomembrane to improve guided bone regeneration.

Recycling leather waste: preparing and studying on the microstructure, mechanical, and rheological properties of leather waste/rubber composite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Recycling leather waste: preparing and studying on the microstructure, mechanical, and rheological properties of leather waste/rubber composite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reproductive physiology, and physical and sexual development of female offspring born to diabetic dams

Objectives: The objective of this study was to evaluate physical and sexual development and reproductive physiology in female rat offspring that developed in hyperglycemia conditions in utero and during lactation. Materials and methods: Maternal diabetes was induced in female rats by a single IV injection of streptozotocin before mating. Female offspring development was evaluated by means of the following parameters: physical development; age of vaginal opening and first estrus; weight and histological evaluation of uterus and ovaries; duration of the estrous cycle, sexual behavior, and fertility after natural mating. Results: In the female offspring, maternal diabetes caused delays in initial physical development; diminution in ovary weight and number of follicles; and inferior reproductive performance compared with the control group. Conclusions: The exposure to hyperglycemia in uterus and during lactation caused delays in physical and sexual development, and affected the reproductive physiology of female rats negatively.

Performance of different rubber tree clones against South American leaf blight (Microcyclus ulei)

This study was aimed to evaluate the behaviour of eighteen clones of Hevea brasiliensis (rubber) against South American leaf blight and tostudy progress of the disease. The experiment was conducted in Cachoeiro de Itapemirim-ES, where 18 clones were evaluated. The experi-mental design was a randomized block with four replicates; each experimental unit consisted of three plants. Evaluations were performed at15-day intervals on 30 leaflets per tree. Disease incidence was quantified and infection classified according to the stages of development andtype of damage. Leaf blight occurred during the entire experimental period; however, disease intensity varied with the resistance level of theclones and the time of year. Clones FX 3864, RRIM 725, RRIM 711, IAC 300 and IAN 873 exhibited the highest resistance to leaf blight.