The composting of organic material is dependent on microbial activity. However, the dynamics of the microbial community during the composting process remain obscure. Here, denaturing gradient gel electrophoresis of 16S rDNA amplicons in a chicken manure-based compost was applied to characterize the components of the microbial community during the composting process. In addition, the activity of key microbial enzymes was monitored. Arcobacter spp. and Marinospirillum spp. were the dominant species prior to composting, whereas Thermotogae spp. became more strongly represented as the composting process proceeded. Bacillus and Cohnella spp. were featured at various phases. Correlation analysis showed that the diversity of the microbial community was positively correlated with the compost pH, its total nitrogen level, its carbon-to-nitrogen ratio and the activity of protease, and negatively correlated with its organic carbon content and seed germination indices. 相似文献
Recent researches have proved that combination of several therapeutic metal ions, such as silicate (Si), calcium (Ca), strontium (Sr) and so on, with biomaterials may have promising effects for stimulating bone regeneration. In the present study, the Sr/Ca containing silicate hybrid materials (Sr/Ca-γ-PGA-silica) with a mimetic native extracellular matrix (ECM) structure have been developed by electrospinning. With the aim to promote the solubility of γ-PGA in aqueous-based solution and introduce Sr/Ca elements into the prepared hybrid materials, SrCO3 and CaCO3 were employed due to their nontoxicity and no by-products during chemical reaction between γ-PGA and SrCO3/CaCO3. Results of SEM, EDX and elemental mapping images showed that Sr and Ca have been successfully incorporated into the prepared fibrous hybrid materials with homogeneous dispersion. Results of ICP-AES revealed that there was continuous Si, Sr and Ca ion release behavior of Sr/Ca-γ-PGA-silica hybrid materials in Tris–HCl buffer solution and the Si ions release rate can be tailored by adjusting the molar ratio of Sr to Ca. Immersion of Sr/Ca-γ-PGA-silica hybrid materials in a simulated body fluid (SBF) resulted in the formation of an apatite-like surface layer within 3 days, indicating their excellent bioactivity. In addition, the prepared Sr/Ca-γ-PGA-silica hybrid materials supported the proliferation and alkaline phosphatase (ALP) activity of osteoblast in vitro, showing their good biocompatibility. Altogether, the results indicated that the prepared Sr/Ca-γ-PGA-silica hybrid materials with an adjusted ionic release behavior have great potential for providing an excellent ECM for osteoporotic bone regeneration.Recent researches have proved that combination of several therapeutic metal ions, such as silicate (Si), calcium (Ca), strontium (Sr) and so on, with biomaterials may have promising effects for stimulating bone regeneration. 相似文献
Microvascular decompression (MVD) is the first choice of surgery for hemifacial spasm (HFS). MVD surgery for vertebral artery (VA)-associated HFS is more difficult than for non-VA-associated HFS. There is controversy about the cure rate and complication of MVD for HFS in previous studies. We searched PubMed, Web of Science, and Embase for relevant publications. Based on the search results, we compared the outcomes of MVD for VA-associated HFS and non-VA-associated HFS. At the same time, we analyzed spasm-free rates and the complications and assessed the relationship between VA-associated HFS and gender, left side, and age. For analysis, six studies that included 2952 patients in the VA-associated group and 604 in the non-VA-associated group were selected. The effective rate of MVD was not significantly different between both groups (OR?=?1.16, 95% CI 0.81–1.67, P?=?0.42). Compared to non-VA-associated group, the transient complications (OR?=?0.64, 95% CI 0.46–0.89, P?=?0.008) and permanent complications (OR?=?0.28, 95% CI 0.15–0.54, P?=?0.0001) occurred more frequently in VA-associated group. The rate of hearing loss was significantly higher in VA-associated HFS than non-VA-associated HFS (OR?=?0.35, 95% CI 0.19–0.64, P?=?0.0007); the facial paralysis after operation was not significantly different between both groups (OR?=?1.25, 95% CI 0.91–1.72, P?=?0.17). There were older patients (WMD?=?3.67, 95% CI 3.29–4.05, P?<?0.00001) and more left-sided HFS (OR?=?0.23, 95% CI 0.19???0.29, P?<?0.0002) in the VA-associated HFS group than non-VA-associated HFS group, while the non-VA-associated HFS group was female-dominated (OR?=?1.58, 95% CI 1.32???1.89, P?<?0.00001). Both groups achieved good results in MVD cure rates. In VA-associated HFS, the complication rate of decompression and the rate of hearing loss after operation were higher than in non-VA-associated HFS, but the facial paralysis after operation was similar in both groups, and most complications were transient and disappeared during follow-up. VA-associated HFS is more prevalent in older adults, less prevalent in women, and more predominantly left-sided. More clinical studies are needed to better compare the efficacy and complication of MVD between both groups.