Research on the Shale Reservoir Sensitivity by Using the Mineral Analysis Method.

Shale reservoirs have diverse mineral types, and analyzing the sensitivity of the mineral composition to shale pores is of great scientific and engineering significance. In this paper, first, X-ray diffraction (XRD) experiments on shale mineral compositions are carried out, and the characteristics of pore structure changes after shale mineral compositions interacted with external fluids (slick water and backflow fluid) are elucidated. Then, the effects of quartz, kaolinite, and pyrite on the pore structure and permeability of shale on the susceptibility to slick water are studied. The results show that (a) quartz and clay minerals are the dominant constituents of each core, with some cores containing minor amounts of plagioclase feldspar and rhodochrosite. (b) The composition of the shale changed significantly following the action of external fluids. The average quartz content of pure shale decreased from 31.62% to 29.1%. The average content of quartz in siliceous shale decreased from 36.53% to 33.5%. The average content of quartz in carbonaceous shale decreased from 9.15% to 8.05%. (c) Factors affecting the sensitivity of shale pore structure and permeability to slick water are mainly quartz, kaolinite, and pyrite. The contents of quartz, kaolinite, and pyrite decreased by an average of 5.1%, 4.6%, and 0.9%, respectively, after slick water action.

[An optimized method for embedding undecalcified mouse tibias in plastic blocks].

OBJECTIVE: To optimize the method for embedding multiple undecalcified mouse tibias in plastic blocks, improve the efficiency and stability of plastic embedding and reduce the detachment rate of plastic slides. METHODS: Thirty undecalcified tibias from 15 B6 mice were used for plastic embedding after calcein labeling, fixation, dehydration and infiltration. The tibias were embedded in cylindrical plastic blocks with a diameter of 4 mm. For each bone, the 1/4 proximal tibia was cut off, and the remaining 3/4 was used for re-embedding. Five bones were embedded in a single block with each bone standing closely on the surface of a flat plate. The samples were randomized into control and experimental groups in all the processes of embedding, sectioning and staining. In the 3 groups with modified embedment, flowing CO2 was added into the embedding solution, embedding solution was applied to the section surface, and the slides were heated at 95 ℃ for 15 min. The polymerization time, slide detachment rate, bone formation and osteoblast parameters were analyzed. RESULTS: We prepared 6 plastic blocks, each containing 5 tibias, whose cross sections were on the same plane. The blocks were completely polymerized and suitable for sectioning. Flowing CO2 into the embedding solution reduced the polymerization time and increased the rate of complete polymerization. Application of the embedding solution on the section surface significantly reduced the detachment rate of the sections (P < 0.05) without affecting bone formation analysis (P > 0.05). Heating the slides significantly lowered the detachment rate of the sections (P < 0.05) without affecting osteoblast analysis (P > 0.05). CONCLUSIONS: The optimized method allows effective embedding of multiple undecalcified mice tibias in the same block and can be an ideal method for histological analysis of undecalcified bones.

[Expression of vasoactive intestinal peptide in peripheral blood of children with hand, foot and mouth disease].

OBJECTIVE: To investigate the expression of vasoactive intestinal peptide (VIP) in peripheral blood of children with hand, foot and mouth disease and its significance. METHODS: According to the condition of the disease, 86 children with hand, foot and mouth disease were classified into phase 1 group (19 children) and phase 2 group (67 children). ELISA was used to measure the concentrations of plasma VIP, interferon-γ (IFN-γ), and interleukin-4 (IL-4) in peripheral blood. Flow cytometry was used to measure CD3+, CD4+, and CD8+ T lymphocyte subsets. RT-PCR was used for qualitative detection of enterovirus 71 (EV71) RNA in stool. RESULTS: Compared with the phase 1 group, the phase 2 group had a significantly higher positive rate of EV71-RNA (P<0.05) and significantly higher serum levels of IgG, IgA, IgM, and C3 (P<0.05). The phase 2 group had significantly lower proportions of peripheral CD3+, CD4+, and CD8+ T lymphocyte subsets than the phase 1 group (P<0.05), as well as significantly lower proportion of peripheral B cells and CD4+/CD8+ ratio than the phase 1 group (P<0.05). The phase 2 group also had a significantly lower concentration of VIP in peripheral blood than the phase 1 group (P<0.05). In the 86 children with hand, foot and mouth disease, the concentration of VIP in peripheral blood was positively correlated with the proportion of CD4+ T lymphocyte subset and CD4+/CD8+ ratio (r=0.533 and 0.532 respectively; P<0.05). CONCLUSIONS: VIP may be an important marker of the severity of hand, foot and mouth disease.

[A descriptive study on the smoking pattern among general population in Xuzhou, 2008.].

OBJECTIVE: To understand the prevalence of smoking in different sub-populations in Xuzhou area so as to develop effective tobacco control policies. METHODS: Through multi-stage randomized cluster sampling, a face-to-face study with standard questionnaire was carried out among residents aged above 15 years, from June to December 2008, with descriptive nature. RESULTS: Totally, 44 686 people, with 21 524 males and 23 162 females at age 15 and over were investigated, including 34 391 of them from rural areas and 10 295 from the urban population. Data regarding rates on ever smoked and current smoking, regular smoking, heavy smoking, and average numbers of cigarettes smoked per day, types of tobacco products smoked, rates on quitting smoking successfully, relapse, passive smoke exposure etc., were 22.45%, 21.40%, 15.49%, 9.49%, 15.09/d, 4.68%, 5.91% and 14.12% respectively. There were no significant differences in the rates of overall smoking, current smoking and regular smoking among urban and rural residents (P > 0.05). However, rates of successfully quitting smoking and passive smoke exposure in the urban areas were higher than those in the rural areas (P < 0.05). Rates regarding relapse, heavy smoking and average numbers of cigarettes smoked per day in the rural areas were higher than those in the urban areas (P < 0.05). Rates on smoking, current smoking, regular smoking, heavy smoking, relapse and average numbers of cigarettes smoked per day were higher in males than those in females (P < 0.05). Rates of quitting smoking successfully and passive smoke exposure were higher in females than those in males (P < 0.05). The major types of tobacco products smoked by people aged 15 years old and above were cigarettes (85.17%), and Chinese pipes (3.24%). CONCLUSION: Smoking was quite common in people from Xuzhou. Our data suggested that health education should be strengthened and sustainable intervention measures be developed and implemented to control the tobacco use in the area.