A laboratory study on cold-mix, cold-lay emulsion mixtures

This paper describes laboratory experiments and presents results for the performances of cold-mix, cold-lay emulsion mixtures. The main objective of the experiments was to evaluate and improve the properties of the cold mixtures. The mixture properties evaluated were: volumetric properties, indirect tensile stiffness modulus (ITSM), repeated load axial creep and fatigue. These properties were compared with conventional hot asphalt mixtures not containing any waste/recycled materials. To optimise the performances of the mixtures, a target of ITSM value of 2000 MPa was selected. At full curing conditions, the stiffness of the cold mixes was found to be very similar to that of hot mixtures of the same penetration grade base bitumen (100 pen). Test results also show that the addition of 1–2% cement significantly improved the mechanical performance of the mixes and significantly accelerated their strength gain. The fatigue behaviour of the cold mixes that incorporated cement was comparable with that of the hot mixtures

Hidroxiuréia em pacientes com síndromes falciformes acompanhados no Hospital Hemope, Recife, Brasil Hydroxyurea in sickle cell disease patients in Recife, Brazil

O uso de hidroxiuréia promove a elevação dos níveis de hemoglobina fetal (Hb F) em pacientes portadores de síndromes falciformes (SF) e o medicamento vem sendo estudado em vários grupos de pacientes, incluindo adultos e crianças. O presente trabalho analisou a eficácia e tolerabilidade do uso de hidroxiuréia em crianças na faixa etária entre 5 e 17 anos de idade e em adultos jovens acima de 18 anos, portadores de hemoglobinopatia SS ou Sbeta0 que foram acompanhados regularmente no ambulatório do Hospital Hemope. Os pacientes pediátricos foram tratados com dose inicial de hidroxiuréia de 10 mg/kg/dia, a qual era aumentada em 5 mg/kg por dia em intervalos de oito semanas, até a dose máxima de 25 mg/kg/dia. Para os adultos, o tratamento foi iniciado com 500 mg/dia de hidroxiuréia até a dose máxima de 1g/dia. Foi observada redução do número de crises álgicas assim como do número de internações hospitalares, elevação do nível de Hb F e do Volume Corpuscular Médio, no grupo pediátrico. Entre os pacientes maiores de 18 anos, também se observou melhora clínica e significância estatística com aumento dos valores da hemoglobina e redução dos valores de reticulócitos, leucócitos e plaquetas. Não foram observados sinais ou sintomas sugestivos de toxicidade medicamentosa em ambos os grupos. O uso de hidroxiuréia em todos os pacientes parece ser seguro e eficaz e assegura melhora da qualidade de vida e benefícios a seus familiares. Ademais, as doses preconizadas de hidroxiuréia aparentemente não foram mielotóxicas, não tendo sido necessária a suspensão do tratamento em nenhum dos pacientes.<br>The use of hydroxyurea increases concentrations of fetal hemoglobin (Hb F) in sickle cell disease patients. It has been used in adults and in trials with children with the aim of preventing events such as episodes of pain or stokes. The objective of this study was to analyze the efficacy and side effects of Hydroxyurea in children with ages ranging from 5 to 17 years and also in young adults with SS or Sbeta0 hemoglobinopathies. The patients were treated in the outpatient clinic of the Hemope Hospital. Young patients were treated with hydroxyurea at 10 mg/kg/day which was increased by 5 mg/kg/day at 8-week intervals until reaching a maximum dose of 25 mg/kg/day. For adults, the treatment started at 500 mg/day and increased until a dose of 1000 mg/day was reached. Total Hb F levels and the Mean Corpuscular Volume rose with hydroxyurea therapy and there was a reduction of events involving pain as well as the necessity of hospitalization among the pediatric patients. With the over 18-year-old patients, a better clinical state was noticed together with a rise in hemoglobin levels and a reduction in the reticulocyte, leukocyte and platelet counts. No signs or symptoms in respect to drug toxicity were evidenced in either group. The use of hydroxyurea seems to be safe and effective in both children and young adults with sickle cell disease. The drug also improves the quality of life of these patients and their families. Additionally, the dosages of hydroxyurea used in this group of patients did not cause any bone marrow toxicity or other side effects