Following the basic theory of protecting gas-reservoirs from damage with the temporary bridging technology, inert calcium carbonate (CaCO3) particles, whose diameter is consistent with the size of pores or apertures in the reservoir, were selected as the bridging agent, and modified resolvable starch was selected as filtration loss reducing particles to form the non-clay low damage temporary bridging drilling/completion fluids system (NLTDFS). Under the simulated condition of the well bottom during real drilling, NLTDFS was used to conduct dynamic and static damage experiments of cores for 48 hours, respectively, and then the experimented cores were permeated with pure nitrogen from the undamaged end to the damaged one to measure their recovery of permeability. The results showed that the permeability recovery rate of the core reached 90% or so, and the damaged depth was less than 1 cm, which demonstrates that NL TDFS has higher temporary bridging effectiveness and lower damage to the gas-reservoir than other drilling fluids system. NLTDFS has been used to drill many horizontal wells, and four of them have obtained high yield of natural gas. The yield of natural gas of LPl well reached 85 X 104 m3/day after completion with the rump pipe. The formation of the stable well wall and smooth drilling led to an API loss less than 4 mL and an HTHP loss less than 15 mL.

In the presence of hydrochloric acid, tetraethoxysilicane was hydrolyzed and formed silica sol. Non-labeled immunosensor was fabricated by droping the mixture solution of the silica sol and antibody of aflatoxin B_1 on the surface of glassy carbon electrode. In this work, a Fe(CN)_6~(3-/4-) phosphate buffer solution) was employed as base solution for investigating cyclic voltammetry(CV) and electrochemical impedance spectroscopic(EIS) performances of the sensor, respectively. The experimental results t indicated that because of the complex formed by the immunoreaction hindered the diffusion of Fe(CN)_6~(3-/4-) on the electrode surface, the redox peak current of the immunosensor in CV obviously decreased, and its electron transfer impedance linearly) increased with increasing the concentration of aflantoxin B_1(AFB). When the medium acidit and incubation) time were pH 6.5 and 20 min, respectively, the biggest electron transfer impedance changed value before and after the immunoreaction was obtained. Under the optimal conditions, a linear range to concentration of aflatoxin B_1 was 1-10 μg/L with a detection limit of 0.1 μg/L(S/N=3). Proposed method is of high sensitivity and stability, it has been successfully applied to determine AFB_1 in maize, rice and peanut.

Purpose To explore the accuracy of ALK fused gene expression by immunohistochemistry ( IHC) in non-small cell lung cancer ( NSCLC) patients, and to investigate the clinical and pathological features of ALK-positive NSCLC patients. Methods By u-sing rabbit monoclonal D5F3 antibody, ALK IHC was performed on 234 NSCLC patients. ALK positive cases were confirmed by reverse transcription-polymerase chain reaction ( RT-PCR) . Results The positive incidence of ALK by IHC in 234 NSCLC specimens was 8. 97% (21/234), the positive rate of ALK fused gene verificated by RT-PCR was 5. 98% (14/234). There was significant difference with histological type, age, stage (P<0. 05), but no significant difference with gender, smoking history, tumor differentiation. Of 21 cases of ALK-positive NSCLC patients, the consistency of IHC and RT-PCR was 0 when IHC was ( +) , however, when IHC was or immunohistochemical score was >120, the consistency rate was 100%. Conclusion Although immunohistochemical expres-sion of ALK fused gene may have a certain false positive, IHC or immunohistochemical score> 120 show very high value for ALK fused gene RT-PCR followed by ALK immunohistochemistry in lung cancer is a economical and feasible method for the valuation of ALK fused gene.