ABSTRACT
Hedera helix has been reported to contain a wide range of metabolites and produce many pharmacological effects. This research demonstrates the determination and evaluation of the phytochemical profiling of H. helix grown in central Vietnam. Methanolic extract of ivy had been analyzed by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). MS, and MS/MS experiments were manipulated using both negative and positive ionization modes to provide molecular mass information and production spectra for the structural elucidation of compounds. A total of 46 compounds including 24 triterpene saponins and other compounds were successfully identified of which four established saponin structures have been reported for the first time. This study has provided a base for building a quality control of the raw materials according to the profile of triterpene saponins and assessment of pharmaceutical ingredients of H. helix planted in Vietnam.
ABSTRACT
Municipal Solid Waste Incinerator (MSWI) Bottom Ash has been used as a substitute for traditional aggregates in road construction; however, this material is little understood. The work presented in this paper pursues the study on the mechanical performance of bottom ash, proven by Le et al. (2017). Using a coupling technique for the first time, the physicochemical aspects and hydromechanical resistance of bottom ash were evaluated and analyzed. Physicochemical tests were first carried out, followed by oedometer tests under a wetting path. This coupled evaluation underlined the role of principal mineralogical components of the studied bottom ash as well as the link with its hydromechanical properties. Tests results showed that the principal constituent of bottom ash is SiO2, which thus affects the characteristics of bottom ash. Given the physical stability of SiO2 which generated a compacted material being less sensitive to water and chemical reactions, and bottom ash's other characteristics, this demonstrates why bottom ash could be a viable material in roadworks.
Subject(s)
Coal Ash , Solid Waste , Construction Materials , Incineration , Silicon Dioxide , WaterABSTRACT
Bottom ash resulting from the incineration of various domestic wastes can be viewed as a typical granular material. It is mainly used in civil engineering as a substitute for traditional natural aggregates. The purpose of this paper is to characterize their mechanical behavior and evaluate their mechanical properties for engineering applications. First, results of triaxial tests confirm that bottom ash behaves like dense sand. Second, the deformation and strength characteristics of bottom ash, such as the secant modulus, Poisson ratio, characteristic angle, dilation angle, effective cohesion and effective friction angle, are determined. It is found that these mechanical parameters are in close agreement with those of road aggregates and are influenced by the effective confining pressure. Third, the evolution of the deformation modulus according to the axial strain and the variation of the deviator stress according to the mean effective pressure are analyzed. Finally, a set of points of the yielding state is determined from triaxial tests to represent the shape of the yielding surface of bottom ash.
Subject(s)
Coal Ash , Solid Waste , Incineration , Silicon DioxideABSTRACT
The pharmacokinetics of dihydroartemisinin (DHA) in a 5-day oral monotherapy regimen was investigated in ten adult Vietnamese patients with uncomplicated falciparum malaria. The patients were treated with a total dose of 900 mg DHA divided as single daily doses of 300, 300, 100, 100, and 100 mg from day 0 through day 4. There were no differences in the concentrations of DHA within the first two days of treatment. The pharmacokinetics of DHA in the acute phase, however, was significantly different from that in the convalescent phase of malaria. Reduced half-life (T(1/2z)) and lower area under concentration curve (AUC(infinity)) values were observed on the final day of treatment in comparison to those obtained on the first day. These decreases in T(1/2z) and AUC(infinity) were observed in concordance with increased drug clearance (CL/F). Furthermore, the time required to reach maximum plasma DHA concentration (T(max)) on day 4 was shorter than that on day 0. Together, these findings suggest that the change in pharmacokinetics of DHA is related to the physiological change in malaria patients between the acute and convalescent phases of the disease.
