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91.
  总被引:2,自引:0,他引:2  
An enzyme-linked immunosorbent assay (ELISA) is described for the detection of reticuloendotheliosis viruses (REVs). The assay uses a mixture of monoclonal antibodies (MCAs) prepared against a 62-kilodalton REV envelope glycoprotein (gp62) to capture antigen, rabbit anti-REV serum as detection antibody, and peroxidase-conjugated anti-rabbit IgG as indicator antibody. The MCAs were reactive with REV strain T, chick syncytial virus, and duck infectious anemia virus but unreactive against Marek's disease and avian leukosis viruses. The ELISA was compared with complement fixation test and REV immunofluorescent assay of infected fibroblasts, plasmas, and egg albumen from infected chickens. The lower limit of gp62 detection was about 120 ng of REV protein. Limit dilution of infectious REV was detected after 7-8 days of cultivation of infected fibroblasts.  相似文献   
92.
    
Wang  Xiangxiang  Cui  Yongxing  Wang  Yuhan  Duan  Chengjiao  Niu  Yinan  Sun  Ruxiao  Shen  Yufang  Guo  Xuetao  Fang  Linchuan 《Journal of Soils and Sediments》2022,22(2):536-546
Purpose

Variation in soil microbial metabolism remains highly uncertain in predicting soil carbon (C) sequestration, and is particularly and poorly understood in agroecosystem with high soil phosphorus (P) variability.

Materials and methods

This study quantified metabolic limitation of microbes and their association with carbon use efficiency (CUE) via extracellular enzymatic stoichiometry and biogeochemical equilibrium models in field experiment employing five inorganic P gradients (0, 75, 150, 225, and 300 kg P ha?1) in farmland used to grow peas.

Results and discussion

Results showed P fertilization significantly increased soil Olsen-P and NO3?-N contents, and enzyme activities (β-1,4-glucosidase and β-D-cellobiosidase) were significantly affected by P fertilization. It indicated that P fertilization significantly decreased microbial P limitation due to the increase of soil available P. Interestingly, P application also significantly decreased microbial nitrogen (N) limitation, a phenomenon primarily attributable to increasing NO3?-N content via increasing biological N fixation within the pea field. Furthermore, P fertilization increased microbial CUE because the reduction in microbial N and P limitation leads to higher C allocation to microbial growth. Partial least squares path modeling (PLS-PM) further revealed that the reduction of microbial metabolic limitation is conducive to soil C sequestration.

Conclusions

Our study revealed that P application in agroecosystem can alleviate not only microbial P limitation but also N limitation, which further reduces soil C loss via increasing microbial CUE. This study provides important insight into better understanding the mechanisms whereby fertilization mediates soil C cycling driven by microbial metabolism in agricultural ecosystems.

  相似文献   
93.
94.
Journal of Soils and Sediments - Determining soil extracellular DNA decomposition dynamics is essential to assessing lateral gene transfer possibility, nutrient-cycling efficiency, and the...  相似文献   
95.
    
Wang  Lixia  Yan  Baixing  Prasher  Shiv O.  Ou  Yang  Bian  Yu  Cui  Hu 《Journal of Soils and Sediments》2019,19(12):4031-4041
Journal of Soils and Sediments - Hydrological condition is one of the important factors impacting microbial structure in riparian wetlands. However, how these microbial communities respond to...  相似文献   
96.
张宏  赵炳刚 《油气储运》1996,15(3):42-44
目前国内外采用的管道试压方式大致有两种,一种是在试压时控制管道环向应力水平;另一种是以管道中试压介质的压力容积图控制试压,以前者作为试压方式虽然简便,但因其将每根管子管材的屈服极限作为非变量,因而用同一应力水平试压极有可能造成管材过分屈服或试压不足,试压应力难以确定。而后者只控制试压过程中压力容积图的线性关系,即在图形出现非线性时停止加压,避免了试压应力骓以确定的问题,多项研究和统计表明,试压应力  相似文献   
97.
98.
本文从南北坡差异、人为影响、森林火灾、地形、土壤等方面研究分析了化龙山南坡上部亚高山草地的成因,结果表明,风是草地形成的主因。  相似文献   
99.
对华北地区经济树种蚧虫的种类区系、发生和分布规律及为害特点进行了系统研究。据调查,现已知华北经济树种蚧虫共有9科122种。随纬度增高、立地条件恶化、植物群落简单、人为活动频繁、管理水平粗放,蚧虫种类增多,为害严重。一般情况下,观赏树木受害普遍,温室植物受害严重,果树及平原地区林木部分受害,山地森林受害轻微。  相似文献   
100.
During enzymatic modifications of silk fibroins, the accessibility of tyrosinases to the reactive sites was limited owing to the steric hindrance of tyrosine residues in the fibroin proteins. To improve the reactivity of silk fibroin, a tyrosine-containing peptide (TyrP) was covalently grafted onto the fibroin surfaces using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enzymatic oxidation of the modified fibroins was subsequently carried out with a mushroom tyrosinase, followed by coupling of ε-polylysine (ε-PL) with the generated o-quinone residues of silk fibroins. The efficacy of grafting reaction was examined by means of SDS-PAGE and amine acid analysis. The results indicated EDC treatment might cause the direct self-crosslinks of silk fibroins and TyrP-bridged cross-links of fibroin molecules as well, which led to a noticeable increase in the molecular weight of fibroin proteins. TyrP-grafted fibroins displayed higher reactivity compared to the untreated, and more ε-PL was bonded to the fibroin surfaces when incubating with tyrosinase, resulting in improved wettability and mechanical property. The presented work offers an efficient alternative for the enzymatic modification of the fibroin-based materials with tyrosinase.  相似文献   
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