Achene mucilage formation process and extrusion from hydrated pericarp of Mirabilis himalaica

Myxospermy is an important feature of achenes of the alpine plant Mirabilis himalaica,and the achene mucilage increases the germination rate and early seedling growth during exposure to abiotic stresses,which has important functions that allow M.himalaica to survive the extreme climate of the Tibet Plateau.However,achene formation and mucilage extrusion are poorly understood.In the present study,comprehensive analyses were performed on mucilage production during achene development and mucilage release from hydrated achene pericarp in M.himalaica.First,fertilization initiated the development of M.himalaica achenes,during which their color,size and texture were altered dramatically.Second,using a metachromatic staining procedure,cytological events,the establishment of mucilage secretory cells in the inner epicarp layer were observed.The hydration of mature achenes led to the rapid bursting of mucilage secretory cells,which released a hydrophilic gel that surrounded the achenes.Finally,enzymatic digestion indicated that major components of the mucilage were pectins;glucose(41.40%),rhamnose(26.58%),galactose(18.33%),trehalose(12.12%),and mannose(1.57%)were found to be the components of achene by using ion-exchange chromatography.

Characterization of bubble behaviors in a dense phase pulsed gas-solid fluidized bed for dry coal processing

Pulsed gas-solid fluidized beds can effectively separate fine coal,and bubbles play an important role in creating suitable separation conditions.The present study performed statistical and image analyses of the evolution of bubbles in a two-dimensional pulsed gas-solid fluidized bed using a high-speed dynamic camera.The effects of apparent gas velocity,pulsation frequency and particle size on bubble characteristics and bed expansi on were analyzed.The results indicate that,when a fluctuation freque ncy is added,the expa nsion height of the bed in creases,the effect of attachme nt to the bed wall decreases,the leading diameter and rising velocity of the bubbles both decrease and the degree of bubble deformation increases.These trends are also more obvious for fine particles.These findings dem on strate that a high density pulsed gas-solid fluidized bed can effectively combine gases and solids to produce a uniform,stable mixture.The bubble diameter and rising velocity were also simulated in the present work,and the relationship between the two was established using a fitting model with an error within 5%.This model provides an effective means of predicting bubble velocity as well as studying the distribution of the bubble phase and improving the stability of the bed density.

Synthesis of 7-Triazole-substituted Camptothecin via Click Chemistry and Evaluation of in vitro Antitumor Activity

Camptothecin(CPT)is a natural topoisomerase I inhibitor with powerful antineoplastic activity against colorectal,breast,lung and ovarian cancers.To discover more potent antitumor agents,a series of new CPT derivatives were synthesized utilizing click chemistry.All compounds were assessed for cytotoxicity against A549,HCT-116,HT-29,LoVo,MDA-MB-231 cell lines,and some compounds exhibited good in vitro potency.Furthermore,all compounds kept or enhanced Topo I inhibition.