ABSTRACT
This research summary the trend in synthesis of Hydroxyapatite (HA) using different route such as dry method and wet method (co-precipitation method; emulsion method, hydrolysis method, sol-gel method, hydrothermal method). In addition, the research group also report the technique to synthesis nano-structure HA by hydrothermal reaction using Ca(OH)2 and H3PO4 with the Ca/P molar ratio of 1.67. The mixture after homogenized for 2 h, follow by hydrothermal reaction at different hydrothermal temperature time (100 °C, 150 °C, and 180 °C) and different hydrothermal reaction time (0 h, 12 h and 24 h). The 180 °C-hydrothermal treated-HA has needle-like shape with the diameter of 10 ~ 20 nm and length of below 100 nm, which is similar with human bone. For the hydrothermal reaction, temperature is the key to form nanostructure HA.
Subject(s)
Durapatite/chemical synthesis , Nanostructures/chemistry , Humans , TemperatureABSTRACT
OBJECTIVES: To identify demand for Vi typhoid fever vaccine for school-age children; obstacles and enabling factors for vaccine delivery; and socio-behavioural factors associated with trial participation and possible predictors of future vaccine acceptance, in Hue City, Viet Nam. METHODS: Pre- and post-trial surveys of randomly selected households with children aged 6-17 years. Simple multinomial logistic analyses for ratios of relative risks (RRR) and significance on trial participation by demographics and variables related to typhoid fever, vaccination, and pre-trial experiences with information and consents. Multiple logistic regressions to assess differences in participation based on child's characteristics. RESULTS: As many as 62.6% of households let all school age children participate, 10.2% let some participate, and 26.8% let none of their children participate in the trial. Factors associated with all children participating included past use of healthcare facilities (RRR, 0.45; 95% CI, 0.24-0.83), knowledge of vaccines (RRR, 0.17; 95% CI, 0.03-0.86), and perceived causes of typhoid fever (RRR, 0.90; 95% CI, 0.81-0.99). Factors associated with some children participating included utilization of healthcare facilities (RRR, 0.08; 95% CI, 0.01-0.66) and perceived severity of typhoid fever (RRR, 0.64; 95% CI 0.46-0.88). Participation was associated with satisfaction regarding pre-vaccination information and consent procedures. Children and adolescents were active decision-makers. Only 14 of 461 (2.2%) respondents would not use the Vi vaccine in the future for their child(ren). CONCLUSIONS: Inter-related factors contribute to participation in a clinical vaccine trial, which may differ from desire to participate in a public health campaign. Educational campaigns need to be targeted to children and adolescents, and consideration for assent procedures for minors. Obtaining informed consent may affect trial participation within a social and political system unaccustomed to these procedures.
Subject(s)
Patient Acceptance of Health Care/psychology , Polysaccharides, Bacterial/therapeutic use , Typhoid Fever/prevention & control , Typhoid-Paratyphoid Vaccines/therapeutic use , Adolescent , Adult , Child , Culture , Family Characteristics , Female , Health Care Surveys/methods , Health Knowledge, Attitudes, Practice , Humans , Informed Consent/psychology , Male , Middle Aged , Parents , Patient Education as Topic/standards , Patient Participation/psychology , Patient Satisfaction , Regression Analysis , Severity of Illness Index , Typhoid Fever/epidemiology , Typhoid Fever/psychology , Vietnam/epidemiologyABSTRACT
We assessed the long-term protection afforded by a killed whole-cell oral cholera vaccine produced in Vietnam. A mass immunization of children and adults with the killed whole-cell oral cholera vaccine was undertaken in half of the communes of Hue, Vietnam, in 1998; the remaining communes were immunized in 2000. No cholera was observed in Hue until 2003, when an outbreak of El Tor cholera made it possible to conduct a case-control study. The overall vaccine effectiveness 3-5 years after vaccination was 50% (9-63%). This low-cost, easily administered vaccine should be considered as a tool for the control of cholera.
