A new strategy for the enrichment of ammonia-oxidizing archaea in wastewater treatment systems: The positive role of quorum-sensing signaling molecules.

Ammonia-oxidizing archaea (AOA) play an important role in natural nitrogen cycle, but are difficult to be enriched in wastewater treatment systems. In this experiment, under ambient temperature and high dissolved oxygen, different types of acyl-homoserine lactones (C6-HSL, C8-HSL, C10-HSL, C14-HSL and 3-oxo-C14-HSL) were added to five wastewater nitrification systems to achieve AOA enrichment. Results showed that AOA couldn't be detected in the blank group without the addition of signaling molecules, while the AOA could be detected in all the reactors with the addition. The enrichment effect of AOA was not obvious with added 100 or 200 nmol/L signaling molecules, while the enrichment effect was both obvious with added C8-HSL of 400 nmol/L and C10-HSL of 800 nmol/L. And relative abundance of AOA increased from undetected in the control group to 1.10 % and 0.96 %, respectively. The exogenous signaling molecules may provide new view for AOA enrichment in wastewater treatment systems.

A suppository-base-matrix tablet for time-dependent colon-specific delivery system

Our research has focused on the main design features and release performances of time-dependent colon-specific (TDCS) delivery tablets, which relies on the relative constancy that is observed in the small intestinal transit time of dosage forms. But inflammatory bowel disease（IBD）can affect the transit time, and usually results in watery stool. Compared to the TDCS and wax-matrix TDCS tablet, a promising time-dependent colon-specific delivery system was investigated. In our study, a suppository-base-matrix coated tablet was evaluated. Water soluble suppository-base helps the expansion of tablet, facilitates uniform film dissolution and achives high osmotic pressure. Combining the expansion of carboxymethyl starch sodium (CMS-Na) and the moisture absorption of NaCl, the coated TDCS tablet obtained a burst and targeted drug delivery system. A very good correlation between in vitro drug release and in vivo outcome was observed. This TDCS coated tablet provides a promising strategy to control drug release to the desired lower gastrointestinal region.

Nossa pesquisa focou-se nas principais características de planejamento e de desempenho de liberação cólon-específica tempo-dependente (TDCS) de comprimidos, que leva em conta a constância relativa observada no tempo de trânsito intestinal das formas de dosagem. A doença inflamatória do intestino (IBD) pode afetar o tempo de trânsito e, geralmente, resulta em fezes aquosas. Comparando ao TDCS e a comprimidos TDCS com matriz-cerosa, investigou-se sistema promissor de liberação cólon-específica tempo-dependente. Em nosso estudo, avaliou-se comprimido revestido com matriz base de supositório. A base de supositório solúvel em água auxilia a expansão do comprimido, facilita a dissolução uniforme do filme e atinge alta pressão osmótica. Associando a expansão do carboximetil amido sódico (CMS-Na) à absorção de umidade do NaCl, o comprimido revestido TDCS originou sistema de liberação direcionado e de erupção. Observou-se correlação muito boa entre a liberação in vitro e a in vivo do fármaco. Este comprimido revestido TDCS representa estratégia promissora para o controle da liberação do fármaco na região gastrintestinal mais baixa.