Research on instability characteristics and precursory effect of coal-rock parting-coal structures.

The slip and instability mechanisms of coal-rock parting-coal structures under uniaxial loading conditions were investigated using experiments and case verification. The slip and the corresponding precursors were described by monitoring the displacement, strain, and acoustic emissions (AEs) of coal and rock parting blocks during testing, and the experimental results were verified by analyzing the microseismic (MS) effects during the working face advancing in a coal seam bifurcation area. The main conclusions were as follows: (1) each slip of the discontinuities sandwiched between coal and rock parting produced shear and tensile cracks, but the shear cracks was dominant; (2) for the instability mode that was characterized by low peak stress, high energy release, and a stable b value of AE, each slip corresponds to a peak frequency of AE, which can reveal the final instability mode; (3) the sudden drop in the fault total area of AE can be regarded as a precursor for the warning fracture or slip instability of a discontinuity; and (4) the MS events in the coal seam bifurcation area were mainly characterized by a wide frequency and high amplitude, especially near the coal bifurcation line, where there were obvious characteristics of low-frequency shear fracture for the MS events. This study is relevant for the early warning of coal-rock dynamic disasters triggered by the slip, fracture, and instability of coal-rock parting compound structures in coal mines.

[Expressions of JNK and p-JNK in advanced prostate cancer and their clinical implications].

OBJECTIVE: To investigate the expressions of JNK and p-JNK in advanced prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and their implications. METHODS: Using immunohistochemistry, we detected the expressions of JNK and p-JNK proteins in 40 cases of paraffin wax-embedded PCa and 21 cases of BPH tissues and analyzed their relationships with advanced PCa and BPH as well as with the pathologic features of advanced PCa. RESULTS: Statistically significant differences were not found in the positive expression rate of the JNK protein between BPH and PCa (42.86% vs 52.50%, P>0.05), non-metastatic and metastatic PCa (53.85% vs 51.85%, P >0.05), Gleason ≤7 and Gleason >7 (58.82% vs 47.82%, P >0.05), PSA ≤20 µg/L and PSA >20 µg/L (57.14% vs 51.52%, P >0.05), or survival >5 yr and survival ≤5 yr (60.00% vs 45.00%, P >0.05), nor in the expression level of p-JNK between BPH and PCa (33.33% vs 35.00%, P >0.05), non-metastatic and metastatic PCa (30.77% vs 37.03%, P >0.05), Gleason ≤7 and Gleason >7 (35.29% vs 34.78%, P >0.05), or PSA ≤20 µg/L and PSA >20 µg/L (43.75% vs 10.93%, P >0.05). However, the expression of p-JNK was significantly higher in the survival >5 yr than in the survival ≤5 yr group of the PCa patients (50.00% vs 20.00%, P <0.05). CONCLUSIONS: PCa patients with highly expressed p-JNK have a longer survival time and the high positive rate of p-JNK is associated with the prognosis of PCa.

[Expressions of ERK and p-ERK in advanced prostate cancer].

OBJECTIVE: To investigate the expressions of extracellular signal-regulated kinase (ERK) and p-ERK in benign and malignant prostate tissues, and whether it can be used as a marker for the prognosis of advanced prostate cancer (PCa). METHODS: Using immunohistochemical Envision, we detected the expressions of ERK1/2 and p-ERK1/2 in 20 cases of benign prostatic hyperplasia (BPH) and 40 cases of advanced PCa and analyzed their correlation with PCa metastasis, Gleason score, PSA level, and prognosis. RESULTS: The expression of ERK1/2 was remarkably higher in the advanced PCa than in the BPH cases (82.5% vs 55%, P<0.05), which was not associated with cancer metastasis, Gleason score, PSA level, or survival time of the patients with advanced PCa, and so was that of p-ERK1/2 (75.0% vs 35%, P<0.05), which was not associated with the Gleason score or PSA level of the PCa patients, either. The expression rates of p-ERK in the metastasis, non-metastasis, survival >5 yr, and survival ≤ 5 yr groups were 61.9%, 89.5%, 57.9%, and 90.5%, respectively, with statistically significant differences among these groups (P<0.05). CONCLUSIONS: ERK1/2 and p-ERK1/2 proteins are highly expressed in advanced PCa and p-ERK1/2 is associated with the metastasis and prognosis of advanced PCa.