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Abstract In order to investigate the expression levels of nerve growth factor (NGF) and its receptors (TrkA and p75) in prehierarchical follicles and oviducts of hens, five 130-day-old laying hens were examined by immunohistochemistry and RT-PCR analysis. NGF and its receptors were expressed in theca cells and granulosa cells of prehierarchical follicles, and they were also expressed in the epithelial cells of oviducts. The expression of the genes NGF, TrkA and p75 were significantly different in prehierarchical follicles (p

The chloride–sulfate corrosion environment of concrete is a significant engineering problem. This paper investigates the effect of the complete/semi–immersion mode on the durability of concrete in a chloride–sulfate environment by using different granulated blast furnace slag (GBFS) dosage rates (10–50%) of a metakaolin (MK)-based geopolymer mortar. The chloride–sulfate corrosion environment is discussed by analyzing the apparent morphology, mass change, and mechanical property change in specimens at the age of 120 d of erosion combined with XRD and SEM. The high Ca content in GBFS has an important effect on the strength and erosion resistance of the metakaolin geopolymer (MGP) group mortar; an increase in the GBFS dosage makes the MGP group mortar denser, and the initial strength of the MGP group mortar is positively correlated with the dosage of GBFS. After 120 d of erosion, the GBFS dosage is negatively correlated with erosion resistance, with the high GBFS dosage groups showing more severe damage. Semi-immersion resulted in more severe deterioration at the immersion–evaporation interface zone due to the difference in the ionic concentration and the 'wick effect' at the immersion–evaporation interface zone. Compared with the commonly used OPC mortar, the M40 and M50 groups have improved strength and corrosion resistance and are suitable for engineering environments in highly erosive areas. [ABSTRACT FROM AUTHOR]

In order to investigate the expression level of nerve growth factor(NGF) and its receptors in the ovary of hens,2 groups (each group contains 5 birds) of 83 and 230 days old laying hens were examined by immunohistochemistry and fluorescence quantitative PCR analyses. The results demonstrated that NGF and its two receptors were not detected in the ovary of 83 days old laying hens,but expressed in thecal cells and granulosa cells of prehierarchical follicles of 230 days old laying hens. Expressions of NGF and its receptors tyrosine kinase A(TrkA) and p75 neurotrophin receptor(p75) in small yellow follicle(SYF) of 230 days old were significantly higher than those in small white follicle( SWF) and large white follicle( LWF). Furthermore, serum levels of estrogen and/ or progesterone were significantly higher in 230 days old than those in 83 days old. Taken together, these results indicated that NGF may play a role in the growth,development and ovulation of hierarchical follicles,and it may also affect the laying rate in different laying periods. [ABSTRACT FROM AUTHOR]