The object of this study is to present the descriptive epidemiology of cancer in children at the world and national levels. The international and national literature published on cancer in children was comprehensively reviewed, with emphasis on reports treating epidemiological aspects of time, place and person. For practical reasons and with the aim of integrating the information, only the more relevant publications were included. Incidence and child mortality were analyzed. Overall incidence is between 100 and 150 (annual rates = cases x 10(6) children). Specific incidence varies according to the type of cancer, the region and the country. The Latin American pattern of neoplasms is constituted by leukemias, lymphomas, and central nervous system tumors (CNST); in the Northamerican/European pattern the CNST appear in second place and in the African pattern, lymphomas show predominance. Incidence is higher among the younger than 5 year olds, from urban environments, and there is a 1% annual increase of cancer in Northamerican children. Child mortality has diminished remarkably, mainly in developed countries, whereas in developing or underdeveloped countries, incidence remains stable or shows a slight fall. The incidence of cancer in children is greater in developed countries, but in underdeveloped countries it may be underestimated. These countries have not managed to reduce the incidence of child mortality caused by cancer, as have the United States or Great Britain. Further studies on the epidemiology of cancer in children are necessary, since many data remain unknown.
Yttrium iron garnet (YIG: Y3Fe5O12) ferrite powders were obtained by the Pechini method from metal nitrates, citric acid and ethylene glycol followed by thermal annealing at Tan = 900°C, 1000°C, 1100°C and 1200°C. X-ray diffraction (XRD) and Raman spectroscopy were used to study the structural and vibrational properties of YIG powders. Raman spectra of powders showed the same set of bands as the bulk YIG, but they are broadened due to spatial confinement of phonons. Magnetic properties were measured by vibrant sample magnetometer (VSM), founding that magnetic properties are strongly dependent on Tann; in particular the magnetization increases and reaches the bulk value of 27.7 emu/g at T = 1000°C.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.