Improving the Drilling Parameter Optimization Method Based on the Fireworks Algorithm.

The rate of penetration (ROP) is a manifestation of drilling efficiency, and optimizing drilling parameters is an important way to improve it. To achieve a low ROP for a Permian formation in a certain oil and gas field, three single wells in this formation were selected for optimization. An improved fireworks optimization algorithm was proposed for drilling parameter optimization. We first established the objective function that predicted the ROPs for the three wells. The objective function employed a multilayer perceptron neural network as the optimization adaptation function. We then optimized four controllable parameters (weight on bit, rotary speed, pump discharge, and pump pressure) and improved the fireworks algorithm with an adaptive number of various factors. This improvement enhanced the debugging performance of the fireworks algorithm during optimization. The results indicated that the improved fireworks algorithm has significantly enhanced search performance, and the optimum ROPs for the three wells were increased by 38.55, 78.30, and 60.15%, which provides a reference for the controllable parameter setting in the area.

[Effect of triptolide on iNOS and SP expressions in spinal dorsal horn and dorsal root ganglion of rats with adjuvant arthritis].

OBJECTIVE: To observe the analgesic effect of triptolide (TP) of high, middle and low doses on rats with adjuvant arthritis (AA), and the expressions of inducible nitric oxide synthase (iNOS) and substance P (SP) in spinal dorsal horn and dorsal root ganglion (DRG) of corresponding sections, in order to discuss the possible mechanism for the analgesic effect of TP on rats with adjuvant arthritis. METHOD: Fifty SD rats were selected and randomly divided into the normal group (group A), the model group (group B), and TP low (group C), middle (group D), high (group E) dose groups. Except for the group A, all of the remaining groups were injected with 0.1 mL of Freund's complete adjuvant through their right rear toes to establish the model. At 14 d after the model establishment, rats in C, D and E groups were intraperitoneally injected with different doses of TP (0.1 mg x kg(-1) for the group C, 0.2 mg x kg(-1) for the group D, 0.4 mg x kg(-1) for the group E) once a day for 9 days. Then the 50% mechanical withdraw threshold (MWT) was determined. And the expressions of iNOS and SP in lumbar5 (L5) spinal dorsal horn and DRG were detected with the immunohistochemical method. RESULT: The 50% MWT of rats in the group B was significantly lower than that of the group A (P < 0.01). After being treated with TP, the Thermal withdrawal latencies of groups C, D and E were significantly higher than that of the group B (P < 0.01). TP could notably increase the MWT of AA rats, with a certain dose-effect relationship. The immunohistochemical results indicated that the iNOS and SP expressions significantly increased in the group B (P < 0.01), while the positive expression levels of iNOS and SP in groups C, D and E were significantly lower than that of the group B (P < 0.01), with a certain dose-effect relationship. CONCLUSION: TP shows a good analgesic effect on AA, and could inhibit the iNOS and SP expressions in spinal dorsal horn and DRG in rats with adjuvant arthritis, which may be one of action mechanisms for the analgesic effect of TP.

[Effect of Triptolide on expression of NMDAR1 and BSI-B4 binding sites in spinal dorsal horn and dorsal root ganglion in rats with adjuvant arthritis].

OBJECTIVE: To study the analgesic effect of Triptolide(TP) in rats with adjuvant and the possible mechanism. METHODS: Fifty healthy SD rats were randomly divided into normal control group (group A), model group (group B), and low(group C), middle (group D) and high(group E) dose TP treatment groups. Except the group A, each group of rats were reared by toe intradermal injection of 0. 1 mL Freund's complete adjuvant. After 14 days,rats in the C, D and E groups were taken different doses (0. 1 mg/kg group C, 0. 2mg/kg group D, and 0. 4 mg/kg group E) by intraperitoneal injection of TP for 9 days, and then thermal withdrawal latency and the expression of NMDAR1 and BSI-B4 binding sites in lumbar5 (L5) spinal dorsal horn and DRG were detected. RESULTS: Thermal withdrawal latency of rats in group B was significantly lower than that of group A (P <0. 01), while those in group C, D and E were significantly higher than those in group B (P <0. 05 or P <0. 01). TP increased the thermal pain threshold by a quantity-effect relationship; NMDAR-1 and BSI-B4 binding sites expression levels were significantly increased in group B than those in group A (P <0. 01), while those in group C, D and E were lower than those in group B. CONCLUSION: Analgesic effect of TP is related to reducing levels of expression of NMDAR1 and BSI-B4 binding sites in spinal dorsal horn and DRG in rats with adjuvant arthritis.