The structural and bleaching properties of nitric acid-activated Nteje clay was studied to investigate its ability to serve as an alternative to the high cost imported bleaching earth. The clay was mined, sun-dried, grinded, and reacted with different concentrations of nitric acid, ranging from 2 mol.L-1 to 15 mol.L-1. The un-activated and activated samples were characterized to study the struc...

background: prompt gamma neutron activation analysis (pgnaa) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. also it is a valuable diagnostic tool for total body elemental measurements. 252cf and 241am-be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

0

background:   astrocytes are cells within the central nervous system which are activated  in a wide spectrum of infections,  and  autoimmune and  neurodegenerative diseases.in pathologic states, they produce  inflammatory cytokines, chemokines,  and  nitric oxide (no), and sometimes  they induce apoptosis.their protease-activated receptors (pars) can be activated by proteases, e.g.thrombin and ...

Thermal rearrangement of 7,7-dichloro-[a,c]-dibenzo-[4,1,0]-bicycloheptane (1) to 5,6-dichloro-5Hdibenzo-[a,c]-cycloheptene (2) was studied in the solid phase and in solvents with different polarities. Thefirst-order constants at various temperatures for the rearrangement process were evaluated from theabsorption time data. The activation parameters for this rearrangement were obtained from the...

Background: Oocyte vitrification and assisted oocyte activation have increasingly important implications in assisted reproductive technology. However, an important area of concern with matured oocyte cryobiology is that elements of oocytes intimately involved in metaphase-II arrest may be modified by cryopreservation. In a comparison between different cellular characteristics of unvitrified, vi...