Amino acid deletions at positions 893 and 894 of cytotoxin-associated gene A protein affect gastric epithelial cell interactions.

Background: () persistently colonizes the human gastric mucosa in more than 50% of the global population, leading to various gastroduodenal diseases ranging from chronic gastritis to gastric carcinoma. Cytotoxin-associated gene A (CagA) protein, an important oncoprotein, has highly polymorphic Glu-Pro-Ile-Tyr-Ala segments at the carboxyl terminus, which play crucial roles in pathogenesis. Our previous study revealed a significant association between amino acid deletions at positions 893 and 894 and gastric cancer.

[Advances in the research of transformation and stabilization of soil organic carbon from plant and microbe].

Soil organic carbon (SOC) is the core component of terrestrial carbon (C) sink. Exploring the transformation and stabilization mechanism of SOC is key to understand the function of terrestrial C sink which copes with climate change. The traditional perspective is that plant residues are the initial source of SOC.

Contribution of microbial necromass to soil organic carbon formation during litter decomposition under incubation conditions.

We conducted a 512-day incubation experiment to study the dynamics of microbial necromass and soil carbon fraction in the 'litter-soil' transformation interface soil layer (TIS) during litter decomposition, using a perennial C3 herb, , in the loess hills. The results showed that soil microbial necromass was dominated by fungi in the early and middle stages, and by bacteria in the late stage. The contribution of fungal necromass C to mineral-associated organic C (MAOC) was significantly higher (38.

[Effects of vegetation restoration on nutrient and microbial properties of soil aggregates with different particle sizes in the loess hilly regions of Ningxia, Northwest China].

We explored the effects of vegetation restoration on the soil nutrients and microbial pro-perties of soil aggregates with different particle size by comparing soils in a natural grassland which had been restored for nearly 30 years and in cropland in the loess hilly regions of Ningxia. We analyzed the soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), soil basal respiration (CO-C) and respiratory quotient (qCO) of different particle size soil aggregates collected from cropland and natural grassland. The results showed that soil aggregates of natural grassland had more micro-aggregates (particle size <0.

[Concentrations of different carbon and nitrogen fractions in rhizosphere and non-rhizosphere soils of typical plant species in mountainous area of southern Ningxia, Northwest China].

Taking the rhizosphere and non-rhizosphere soils of five typical plants Agropyron cristatum, Artemisia frigida, Pseudoraphis bungeana, Thymus mongolicus, and Artemisia sacrorum in a mountainous area of southern Ningxia as test objects, this paper studied their C and N forms contents. The C and N forms contents in the rhizosphere and non-rhizosphere soils differed with plant species. In the rhizosphere soil of A.