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In order to restore the normal development of nitrogen drilling technology, it is significant to gain a deep and comprehensive insight into the bottom-hole rock failure mechanism induced by gas-induced fracture. In this paper, the mechanism of bottom-hole rock failure induced by gas-induced fracture was analyzed by means of conventional analysis method of wellbore instability. The research suggests when the bottom-hole is gradually approaching the gas-induced fracture, the difference between circumferential stress and radial stress of the crack face gradually increases. The increasing shear stress caused by the difference between principal stresses leads to the compression-shear failure; then, the failure mode evolved from single-shear failure mode to combined mode of shear and tensile failure with the failure zone extending. If the wellbore is connected with the fracture, then the high-pressure gas in fracture carrying plenty of debris is injected into the wellbore, releasing lots of energy. The mechanism analysis of bottom-hole rock failure can explain the abnormal behaviors of logging data in well QL1 located in Baimamiao structural belt, Dayi County, Sichuan Province. The results not only provide a theoretical basis for the prevention and control of bottom-hole rock failure, but also provide a new perspective for studying the dynamic instability of deep rock in the field of petroleum engineering.

Xiyong Wang, Huaiqing Xiao, Dongqiang Wu, Dongliang Zhang, Zhihao Zhang Department of Thoracic Surgery, China Coast Guard Hospital of the People’s Armed Police Force, Jiaxing 314000, People’s Republic of ChinaCorrespondence: Zhihao ZhangDepartment of Thoracic Surgery, China Coast Guard Hospital of the People’s Armed Police Force, No. 16 Nanhu Road, Jiaxing 314000, People’s Republic of ChinaTel +86-13505736019Email zzhhaomail234@163.comBackground: Lots of studies have shown that cyclin disorders can promote tumor development. This study aims to investigate the biological function and molecular mechanism of CCNB2 in lung adenocarcinoma (LUAD).Methods: LUAD data were downloaded from GEO database and TCGA-LUAD database. Differential analysis was conducted to find the differentially expressed miRNAs and mRNAs, while targeted prediction was done for the access of potential target mRNAs. Gene expression level was detected by qRT-PCR and Western blot in human LUAD cell lines A-427, A549, Calu-3, PC-9 and human bronchial epithelial cell line BEAS-2B. MTT, colony formation, Transwell and flow cytometry assays were used to detect cell proliferation, metastasis, and cell cycle changes of PC-9 cell line. The dual-luciferase reporter gene was used to detect the targeted binding relationship of the target miRNA and mRNA.Results: CCNB2 was highly expressed and served as a biomarker indicating poor prognosis in LUAD patients. Cell function experiments confirmed the inhibitory effects of silencing CCNB2 on the proliferation, migration and invasion of LUAD cells and cell cycle was blocked in the G0/G1 phase. In addition, with regard to the regulatory mechanism, we demonstrated that miR-335-5p had binding sites with 3ʹ-UTR of CCNB2, indicating that miR-335-5p could target the regulation expression of CCNB2. In subsequent cell function tests, overexpression of miR-335-5p inhibited the proliferation and metastasis of cancer cells, and the rescue experiments also verified that miR-335-5p could reverse the promotion of CCNB2 overexpression on the progress of cancer cells.Conclusion: In summary, our results revealed that miR-335-5p could target the down-regulation of CCNB2 to inhibit the occurrence and development of LUAD.Keywords: LUAD, CCNB2, miR-335-5p, proliferation, metastasis

Diffuse large B cell lymphoma (DLBCL) has previously been demonstrated to contribute to the mortality of lymphoma with various aggressive features. The prognostic role of the biomarkers latent membrane protein (LMP) 1 and microRNA-(miR)-155 in DLBCL remain controversial. The present study primarily aimed to assess the effect of LMP1 and miR-155 on the survival of DLBCL patients, and additionally evaluate the clinical features to observe their influence on outcomes, compared with previous studies. Formalin-fixed and paraffin-embedded samples were collected from our center between May 2010 and December 2011. Microarray analysis, immunohistochemical analysis and reverse transcription-quantitative polymerase chain reaction were used to evaluate the expression of LMP1 and miR-155. The association between biomarkers or clinical features and patient outcomes was assessed using the log-rank statistical test, Cox proportional hazard model and Kaplan-Meier method. SPSS software was used to statistically analyze the data. A total of 82 patients were included in the present study. The results demonstrated that high expression of LMP1 and miR-155 may be associated with a poor progression-free survival rate, while a high International Prognostic Index score and high expression of LMP1 may be associated with a poor overall survival rate. These results indicated that LMP1 and miR-155 may be novel and reliable biomarkers for the prognostic prediction of lymphoma, and will potentially be analyzed in the future to evaluate patient prognosis.

Structural plane is an important influence factor for the rock mass quality, 3D modelling, borehole hydraulic test and engineering design of underground research laboratory. Xinchang rock mass in Beishan area of Gansu province has been confirmed the preferred site for URL on geological disposal of high-level radioactive waste in China. The characteristics of structural plane in Xinchang rock mass are obtained based on acoustic borehole televiewer and other geological information. The results indicate that the granite rock mass with a high integrity is beneficial for construction of URL. The width of faults around preferred site and incidence in horizontal and vertical decrease as the depth increases. Characteristics of dip and strike of structural plane is the same as other structure in this area. All research results provide meaning information for design of URL and further geological research.

Intervertebral disc (IVD) degeneration is a complicated process that involves both age-related change and tissue damage caused by multiple stresses. In a degenerative IVD, cellular senescence accumulates and is associated with reduced proliferation, compromised self-repair, increased inflammatory response, and enhanced catabolic metabolism. In this review, we decipher the senescence mechanism of IVD degeneration (IVDD) by interpreting how aging coordinates with age-related, microenvironment-derived stresses in promoting disc cell senescence and accelerating IVDD. After chronic and prolonged replication, cell senescence may occur as a natural part of the disc aging process, but can potentially be accelerated by growth factor deficiency, oxidative accumulation, and inflammatory irritation. While acute disc injury, excessive mechanical overloading, diabetes, and chronic tobacco smoking contribute to the amplification of senescence-inducing stresses, the avascular nature of IVD impairs the immune-clearance of the senescent disc cells, which accumulate in cell clusters, demonstrate inflammatory and catabolic phenotypes, deteriorate disc microenvironment, and accelerate IVDD. Anti-senescence strategies, including telomerase transduction, supply of growth factors, and blocking cell cycle inhibitors, have been shown to be feasible in rescuing disc cells from early senescence, but their efficiency for disc regeneration requires more in vivo validations. Guidelines dedicated to avoiding or alleviating senescence-inducing stresses might decelerate cellular senescence and benefit patients with IVD degenerative diseases.

The authors study the nonlinear stability of three-dimensional quasigeostrophic motion on a beta -plane. The criteria obtained are applicable to perturbations of both initial data and parameters in models. For verifying criteria parallel to Arnold's second theorem given by other authors, one has to calculate the lowest eigenvalue of a three-dimensional elliptic partial differential equation with variable coefficients and, for the given criteria, one needs only do the same for the two-dimensional Laplacian.