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This study explores the potential of biosilica including diatom and diatomaceous earth as alternative silica sources for metakaolin-based geopolymers. Diatomaceous earth, composed of fossilised diatom frustules rich in amorphous silica, and diatoms, a sustainable source of renewable biosilica, are investigated for their effectiveness in enhancing geopolymer properties. Through detailed analyses including FTIR, XRD, and SEM, the study evaluates the impact of these biosilica sources on geopolymer compressive strength and microstructure, comparing them with conventional sodium silicate. Results show that diatoms exhibit significant promise, achieving 28-day strength up to 17.9 MPa at a 30% mass fraction, while diatomaceous earth reaches 26.2 MPa at a 50% addition rate, demonstrating their potential as active silica sources. Furthermore, the study elucidates the role of organic matter in biosilica on geopolymerisation, highlighting its influence on active silica release and the strength performance of products. This study proposes a novel pathway to enhance the sustainability of geopolymers through the utilisation of biosilica from diatoms, contributing to advancements in eco-efficient construction materials. [ABSTRACT FROM AUTHOR]

Dong qi, referring to beating beside the navel, was proposed for the first time by Nan Jing. "Beating above the navel" " beating below the navel", and "beating below the heart" in Shanghan Lun all belong to the category of Dong qi. The pathogenesis of Dong qi can be learned from Shanghan Lun. Yang deficiency of the heart, spleen, and kidney, with qi failing to transform body fluids, results in fluid retention. Fluid retention is the key etiological factor of Dong qi. Although there is an exterior pattern with Dong qi, the exterior-releasing and purgative method cannot be used for treatment, or the patient will be impaired of yang and exhausted of yin, fluid circulation will be disturbed, and so on. Reinforcing yang qi to drain water retention is the treatment principle of Dong qi. The coupled medicines of Fuling and Guizhi were commonly used by ZHANG Zhongjing to treat Dong qi. This reflects the treatment principle of strengthening the spleen and warming yang for transforming qi to circulate body fluids. ZHANG Bi, a physician from the Yuan Dynasty who learned from ZHANG Zhongjing, thought that the treatment of Dong qi was based on the method of cultivating earth to restrain water and taking into account the ascending, descending, entering, and exiting of qi of the liver, heart, lung, and kidney while tonifying the spleen, and then created Baoming Siqi Powder (Zhiqiao, Fuling, Fangkui, and Qianhu Powder) for the treatment of Dong qi, which is of great significance to the clinic. [ABSTRACT FROM AUTHOR]