is a G protein-coupled receptor that is downregulated by prolonged exposure to OT. We hypothesized that activation of PKC mediated this OT-induced decrease in OTR expression. Diminished PKC activity in late pregnancy could underlie the increased expression of uterine OTR preceding labor onset. Using cell cultures of transformed human uterine myocytes, we determined the effects of PKC agonists and antagonists on the expression of OTR. We also explored the effects of overexpression of activator protein-1 (AP-1, a mediator of many PKC-and phorbol ester-induced effects) using adenoviral expression vectors for the AP-1 subunits c-Jun and c-Fos. Stimulation of PKC using the phorbol ester 12-O-tetradecanoylphorbol 13-acetate caused a rapid, significant (P Յ 0.05) increase in c-Jun and c-Fos concentrations but a significant decrease in mRNA for OTR within 6 h followed by a significant decrease in OT binding by 24 h. Adenoviral infection of the cells with expression vectors for c-Jun and c-Fos increased the AP-1 subunits but had no effect on OTR expression. Furthermore, there were no changes in c-Fos or c-Jun levels in human intrauterine tissues around the time of labor onset, as measured by Western analyses. We conclude that phorbol ester treatment decreases OTR expression, likely through a mechanism that does not involve AP-1. parturition; G protein-coupled receptor; preterm labor; protein kinase C
Toner powder is an important constituent of a toner cartridge for a laser printer and has potential hazards of combustion and explosion because of its physicochemical characteristics. In this paper, physicochemical, combustible and explosive characteristics of hpQ2612A toner are investigated experimentally. The mean size of the toner powder is about 2.45 μm and it has several organic groups such as carboxyl group, hydroxyl group and carbonyl group which make the toner dust much easier to combust. The TG-DSC curves show that the toner dust is combustible and the combustion process starts at about 368 . The dust explosion characteristics of the toner dust were, respectively: MIE=5~30 mJ, Pmax=0.74 MPa, (dP/dt)max=100.5 MPa/s, LEL=40~50 g/m3. These results reveal that the toner powder is a dangerous industry dust and has the possibility to make tragedy such as combustion or even explosion.
The three-dimensional information of urban buildings is an important issue in urban monitoring, urban planning, urban management and various economic activities. In this paper we introduce a probabilistic approach of urban buildings’ height and location extraction on remote sensing image. According to the distance between the corner of building roof and its shadow on remote sensing image, buildings’ height can be extracted from single remote sensing image and buildings’ location also can be extracted from the classified image. Compared with the measured values, the absolute error of extracted urban buildings’ height and location is less than 1 m. The method is simple, fast and efficient, and is useful in the three-dimensional information extraction of urban buildings.
Pyrolysis characteristics and kinetics of polyurethane insulation materials from waste refrigerators were investigated using TG-FTIR technique under N2 atmosphere. Results showed that the whole thermal process could be divided into three stages and the main pyrolysis occurred in 260-600°C. The distribution activation energy model (DAEM) was applied to analyze the pyrolysis kinetics. The estimated activation energies ranged from 122.8 to 188 kJ/mol and the pre-exponential factors k0 varied from 108 to 1013 s-1. The composition of evolved gas included CFC-11, CO2, CH4, CO, NH3, HCN and some organic compounds, the evolution characteristics of main gas products had also been discussed.
Over the past several decades with significant technological advances there has been continuous increase in plastic manufacturing in China, which has contributed to the production of a great deal of plastics worldwide every year, and at the same time it has resulted in a large amount of plastic solid waste (PSW). It has great potential values for waste plastics to reuse as secondary materials, which may lessen pressure on resource and environment. The paper studies the status of waste plastics in recycling, reusing and reducing on management countering on the increase in the flow of waste plastics in Shanghai. In light of the methodology of life cycle, the study analyzes the environmental impacts associating with the alternatives in a ‘cradle to grave’ approve to PSW technological recycling systems. We will choose regenerating and energy recovery processes based on site investigation and literatures data in Shanghai to analyze recycling options and how various processes affect the environment. Life-cycle methodology was very suitable for evaluating the overall environmental consequences, and could be used for making decisions and planning strategies with the rapid increase of plastic solid waste generation for Shanghai.
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