Thermal decomposition as route for silver nanoparticles

Single crystalline silver nanoparticles have been synthesized by thermal decomposition of silver oxalate in water and in ethylene glycol. Polyvinyl alcohol (PVA) was employed as a capping agent. The particles were spherical in shape with size below 10 nm. The chemical reduction of silver oxalate by PVA was also observed. Increase of the polymer concentration led to a decrease in the size of Ag particles. Ag nanoparticle was not formed in the absence of PVA. Antibacterial activity of the Ag colloid was studied by disc diffusion method

Arterial blood supply of the umbilical region in newborns

The review of national and foreign literature sources presents information on arterial blood supply of the umbilical region in newborns having relevant practical significance due to the development of new surgical approaches in that part of the anterior abdominal wall. Scientific data on the course and location of arteries participating in the blood supply of the umbilical region are summarized. Particular attention is devoted to the description of superficial, superior and inferior epigastric arteries and umbilical arteries. The issues of intervascular connections between the named arteries and other blood vessels are discussed including information on various anastomosis variations and their extent. Various existing viewpoints regarding the location and depth of anastomoses between the vessels essential for blood supply of the umbilical region are presented as well as the layers, through which the main arteries pass, and the character and level of their branching. Features of arterial blood supply of the umbilical region in newborns are also noted. The paper contains data on the role of umbilical arteries in the umbilical region supply in children of that age. It is demonstrated that blood supply of the umbilical region in newborns still poses issues that are insufficiently researched and solved, such as assessing functional capacity of the umbilical arteries, revealing histotopographic peculiarities in the location of blood vessels within the layers and various segments of the umbilical region, topographic and anatomic identification of the segments that are most and least supplied with arterial vessels in that part of the abdominal wall