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In order to reduce the hazards of earthquake disasters on human, basic principle of reducing vibration is discussed by establishing passive vibration isolation model. The calculation results show vibration can be reduced by isolation materials whose deformation modulus (stiffness) should be smaller and damping should be appropriate. Light reinforced soil is a good man-made material, its all physical mechanical parameters can be changed, and anti-pull capacity of soil can be increased. According to the basic principle of reducing vibration, reducing vibration idea using light reinforced soil is brought forward, and the idea has a very important significance for research on reducing earthquake disasters from the angle of ground and foundation.

In the process of drilling well, the kinematics of drill string is quite complicated. The drill string not only vibrates in longitudinal, transverse and torsional direction, but also random impacts and contacts well wall. Considering the random load of drill bit and rock, contact impact of drill string and well wall, a model is proposed to simulate the contact-impact of drill string and formation. The results show that: in the condition of this article the first principal stress of the drill string can reach to 130 MPa, for the random impacts, the strength of drill collar will reduced under cyclic loading; contact-impact is the principal source of drill premature failure. In this paper, an explicit integration and nonlinear finite element was adopted to simulate the collision between the drill string and formation, the process of the collision between the drill string and formation can be revealed compressively and delicately. Through an example, we can obtain the foundation for nonlinear dynamic theory of drill string system collision in the actual work condition, and has important theory significance and academic value.

With the application of ANSYS finite element analysis software and environmental data in ChengDao oil field, a nonlinear finite element model of suspended submarine pipeline coupled with sea-floor soil is developed. Discarding the traditional and imprecise pipeline model with double clamped or simply supported ends, the model is founded on the theory of elastic foundation beam, in which the nonlinear effect between pipeline and sea-floor soil is considered. Base on the model we developed, the influences of span length and shear strength of soil at the ends of span on the span’s natural frequency are discussed. And the effects of span length, shear strength of soil and current velocity on the dynamic response of span are also analyzed in this paper. The model we developed in this paper fits the actual structure better, and the analysis is instructive for preventing and controlling the suspending of submarine pipeline.

Local thinning of submarine pipeline always exists due to the complexity and dynamic of marine environment loads. However, the location and extent of thinning areas are random. Mechanical research on the randomness of local thinning of submarine pipelines is significant for pipeline’s stress analysis and failure evaluation. In this paper, finite element model of locally thinned submarine pipeline is established and based on the Monte-Carlo method, the effect of input random variables on the submarine pipeline’s reliability is analyzed. Probability distribution ranges of equivalent stresses are got and further, relationship equation between confidence level and stress limit has been obtained. The result more accurately reveals the relationships of locally thinned pipeline and its elastic modulus with equivalent stress, which can provide foundation for safety analysis of locally thinned submarine pipeline with internal pressure.

The deep drill string is subjected to many kinds of loading under the condition of vibration and precession, such as tension, compression, bending and torsion, while the temperature and press are very high. Under this circumstance, the shallow drill string is more likely to failure. Based on the force analysis of the drill string, the drilling process of the deep drill string is simulated using finite element software. The stress distribution and displacement of the drill string is obtained under the interaction of drilling pressure, torque and temperature. At the same time, the effect of transverse vibration, longitudinal vibration and torsional vibration, on the stress and displacement of the drill string, is compared. The change law of the natural frequency of transverse vibration varying with the length of drill string, rotational speed and the hole size is discussed. Connected with concrete examples, the reliability and sensitivity of some influencing factors such as external diameter, wall thickness, the minimum yield strength, temperature, elastic modulus, Poisson’s ratio, axial loading and torque is obtained. The main factors that influence the reliability of the drill string are the yield strength and torque. The reliability of the drill string increases as the increase of yield strength, and decreases as the increase of the torque.

Considering the various influencing factors of enrichment of coal bed methane, the evaluation indexes of enrichment for coal bed methane are determined. The weight values of all factors indexes are given and the fuzzy mathematics model is established on the basis of the fuzzy mathematics. As a case study, the fuzzy mathematics model is applied to the assessment of enrichment of coal bed methane. The results show that the No.5 coal seam of Shan 2 of Shanxi formation in Daning-Jixian is a better enrichment area. The evaluation result performed on the basis of the fuzzy mathematics model is in good agreement with the measured result. The example indicates that the method is credible and has high precise. The assessment system established in the paper can be regarded as a reference model in coal bed methane exploitation potential assessment.

In order to know something about the structure reliability of beam pumping unit, the methods of Monte-Carlo and response surface method are used to analyze the pumping unit. According to the analysis and calculation, the approach of how to calculate and analyze the reliability of complex structure is obtained. The results show that using the method of reliability can make the pumping unit more reliable and reveal the components of pumping unit more clearly which can make the design of pumping unit more reasonable.

In this paper, the main design parameters of seal structure for non-API pipe connection are studied. First, as the total contact pressure consists of the radial preload generated by interference fit and the radial pressure caused by gas pressure in pipe, the variation laws of their values changing with the sealing diameter are analyzed. The sealing diameter value which maximizes the total contact pressure can be obtained from the derivation formula for calculating the total contact pressure. Second, considering the yield condition of pipe connection under the internal and the external pressures, the minimum wall thickness of the seal structure is derived. Then the cone angle is calculated by the sealing length and the minimum wall thickness known. Finally, take the 7in casing connection for example, the main design parameters are calculated by the above analysis.

Aim: N -methyl- D -aspartate receptors (NMDAR) are heteromeric complexes primarily assembled from NR1 and NR2 subunits. In normal conditions, NR2 sub-units assemble into homodimers in the endoplasmic reticulum (ER). These homodimers remain in the ER until they coassemble with NR1 dimers and are trafficked to the cell surface. However, it still remains unclear whether functional homomeric NMDAR exist in physiological or pathological conditions. Methods: We transfected GFP-NR2A alone into HEK293 cells, treated the cells with PKC activator 12-myristate-13 acetate (PMA), and then detected surface NR2A sub-units with a live cell immunostaining method. We also used a series of NR2A mutants with a partial deletion of its C-terminus to identify the regions that are involved in the PMA-mediated surface expression of NR2A subunits. Results: NR2A subunits were expressed on the cell membrane after incubation with PMA (200 nmol/L, 30 min), although no functional NMDA channels were detected after PMA-induced membrane trafficking. Immunostaining with an ER marker also revealed that NR2A subunits were exported from the ER after PMA treatment. Furthermore, the deletion of amino acids between 1149-1347 or 1354-1464 of NR2A inhibited PMA-induced surface expression of NR2A subunits. Conclusion: First, our data suggests that PMA treatment can induce the surface expression of homomeric NR2A subunits. Furthermore, this process is probably mediated by the NR2A C-terminal region between positions 1149 and 1464.

Tenosynovial giant cell tumor is a very rare, benign lesion from the synovium. It seldom happens in the temporomandibular joint area and skull base that is difficult to resect and reconstruct. We present a case treated with computer-assisted navigation to help mark the tumor boundaries, protect vital structures, and facilitate the reconstruction process. Follow-up at 6 months after surgery showed no tumor recurrent and good temporomandibular joint function.

The concurrence of 2 independent neoplasias in the ipsilateral parotid and the temporomandibular joint (TMJ) region was infrequently reported. In this article, we present a unique case characterized by the coexistence of a rare salivary gland tumor, basal cell adenoma, of the parotid gland with a ganglion cyst in the ipsilateral TMJ region. A special surgical procedure was also presented here using a modified preauricular incision and transcondylar approach for extracapsular dissection of both lesions. Previously published literature are about the traditional treatment of benign parotid tumors using partial or total parotidectomy with the preservation of facial nerve mainly via an S-shaped submandibular incision and approach. Here, for the first time, a special surgical method using preauricular transcondylar approach for this unique case of synchronous occurrence of parotid tumor and TMJ cyst is reported.

Objective To investigate the role of serum basic fibroblast growth factor (bFGF), estradiol (E2) and urine bFGF in differentiating infantile haemangiomas from vascular malformations. Method Between October 2007 and January 2009, 97 patients with haemangiomas and 25 patients with vascular malformations who had not been treated previously were included in this prospective study. Forty-eight patients with cleft lip and/or palate were selected as controls. The age of all subjects ranged from 1 to 30 months. The serum and urine levels of bFGF were determined by enzyme-linked immunosorbent assay (ELISA). The serum levels of E2 were examined via radioimmunoassay. All data were analysed with SPSS 11.5 software package. Results The concentration of serum and urine bFGF was significantly different among the three groups (haemangiomas, vascular malformations and controls) ( P = 0.027, P = 0.001). Significantly different urine bFGF levels were found in patients with proliferating and involuting haemangiomas ( P = 0.04). The serum E2 levels were significantly higher in patients with haemangiomas than vascular malformations ( P = 0.001) and controls ( P = 0.001). Conclusion Serum bFGF and E2 as well as urine bFGF can be used to supplement the clinical diagnosis of congenital vascular anomalies. Urine bFGF combined with serum E2 may be the most potential markers for diagnosing haemangiomas and determining the proliferating stage of haemangiomas.

The aim of this study was to identify RASA1 mutation in Chinese population with sporadic Sturge–Weber syndrome (SWS). Genomic DNA was obtained from peripheral blood of nine patients with sporadic SWS. The 25 exons, promoter regions (−1,000 bp) as well as intron-exon boundaries of RASA1 were amplified by polymerase chain reaction, and products were sequenced directly. A novel synonymous mutation (c.1229 G > A [p.K420K]) of RASA1 was identified in the present series. It implied that RASA1 may be not a virulence gene, but further study is needed to know RASA1 gene mutation in SWS patients.

Sturge-Weber syndrome (SWS) is a rare, congenital neurocutaneous disorder with a leptomeningeal, facial trigeminal nerve dominative area and choroidal angioma. The cause of this disease remains unclear. Due to the occurrence of localized abnormality of blood vessel formation, somatic mutation has been put forward. Studies have indicated that fibronectin gene expressions in the SWS port-wine-derived fibroblasts are increased. Fibronectin is an important extracellular matrix molecule with key roles in regulating angiogenesis and vasculogenesis, in maintenance of the blood-brain barrier, blood vessel structure and function, as well as brain tissue responses to seizures. This is consistent with the presence of a hypothesized somatic mutation underlying SWS. In this study, we have proposed that fibronectin may be reflection of somatic mutation. Further research should be done to study the role of fibronectin in the pathogenesis of SWS. Understanding the pathophysiology of Sturge-Weber syndrome will help us to establish future neuroprotective strategies and novel treatment modalities.

Gingival epulis represents a family of benign tumors and tumorlike masses of the gingiva. A spectrum of inflammatory and other reactive changes can be observed pathologically as granulation, fibrous or vascular tissue. It may occur at any age, but most commonly found in patients at their twenties and sixties. Women are more frequently affected than men. Surgical excision or removal is the treatment of choice, and wider resection including extraction of the involved teeth and adjacent tissues is often required in order to prevent recurrence. However, wider resection may result in cosmetic and functional problems. Epulis bears some similarities with hemangioma both clinically and histopathologically. Therefore, we hypothesize that intralesional injection of Pingyangmycin may be a safe and effective treatment for epulis. The efficacy of this treatment modality is worthy of further investigation.

Alzheimer's disease (AD) is a neurodegenerative disorder that causes progressive memory and cognitive decline due to the selective neuronal loss in the cortex and hippocampus of the brains. Generation of human induced pluoripotent stem (hiPS) cells holds great promise for disease modeling and drug discovery in AD. In this study, we used neurons with forebrain marker expression from two unrelated hiPS cell lines. As both populations of neurons were vulnerable to β-amyloid 1–42 (Aβ1–42) aggregates, a hallmark of AD pathology, we used them to investigate cellular mediators of Aβ1–42 toxicity. We observed in neurons differentiated from both hiPS cell lines that Aβ induced toxicity correlated with cell cycle re-entry and was inhibited by pharmacological inhibitors or shRNAs against Cyclin-dependent kinase 2 (Cdk2). As one of the hiPS cell lines has been developed commercially to supply large quantities of differentiated neurons (iCell® Neurons), we screened a chemical library containing several hundred compounds and discovered several small molecules as effective blockers against Aβ1–42 toxicity, including a Cdk2 inhibitor. To our knowledge, this is the first demonstration of an Aβ toxicity screen using hiPS cell-derived neurons. This study provided an excellent example of how hiPS cells can be used for disease modeling and high-throughput compound screening for neurodegenerative diseases.