TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma

<p>Abstract</p> <p>Background</p> <p>Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, <it>TFPI-2 </it>was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether <it>TFPI-2 </it>was inactivated epigenetically in nasopharyngeal carcinoma (NPC).</p> <p>Methods</p> <p>Transcriptional expression levels of <it>TFPI-2 </it>was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of <it>TFPI-2 </it>as a tumor suppressor gene in NPC was addressed by re-introducing <it>TFPI-2 </it>expression into the NPC cell line CNE2.</p> <p>Results</p> <p><it>TFPI-2 </it>mRNA transcription was inactivated in NPC cell lines. <it>TFPI-2 </it>was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. <it>TFPI-2 </it>expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration.</p> <p>Conclusions</p> <p>Epigenetic inactivation of <it>TFPI-2 </it>by promoter hypermethylation is a frequent and tumor specific event in NPC. <it>TFPI-2 </it>might be considering as a putative tumor suppressor gene in NPC.</p

Prevalence of atrial fibrillation in different socioeconomic regions of China and its association with stroke: Results from a national stroke screening survey

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia in clinical practice. This study aimed to estimate the prevalence of AF in different socioeconomic regions of China and identify its association with stroke, through a national survey. Methods: The study included 726,451 adults aged ≥40 years who were participants of the China National Stroke Screening and Prevention Project, a nationally representative cross-sectional study. Stepwise logistic regression analyses were conducted to investigate the association between AF and stroke. Results: The overall standardized prevalence rate of AF was 2.31%. The prevalence of AF was highest in high-income regions (2.54%), followed by middle-income regions (2.33%), and lowest in low-income regions (1.98%). Women had a higher prevalence of AF than men in all regions (low-income regions, 2.30% vs 1.65%; middle-income regions, 2.78% vs 1.89%; and high-income regions, 2.96% vs 2.12%). Compared with urban residents, the prevalence of AF among rural residents was higher in low- (2.03% vs 1.91%) and middle-income regions (2.69% vs 1.90%), but lower in high-income regions (2.44% vs 2.58%). Participants with AF were more likely to have a stroke than those without AF (9.48% vs 2.26%). After adjusting for age, sex, location, overweight or obese, smoking, drinking, physical inactivity, hypertension, diabetes, dyslipidemia, and a family history of stroke, results showed that AF was significantly associated with stroke. Conclusions: The prevalence of AF has increased in recent years, and it was positively correlated with socioeconomic status, sex (women), location (rural areas), and stroke

3-D geological modeling for tight sand gas reservoir of braided river facies

Considering the poor applicability of conventional geological modeling to tight sand gas reservoir in braided river facies, a modeling method of “multi-stage constraints, hierarchical facies control and multi-step modeling” was put forward taking Sulige gas field in Ordos Basin as the study object. The method obtains the GR field by seismic inversion constrained by logging data, and GR model is built under the control of the prior geological knowledge; the relation regression is realized between the GR model and the sandstone probability, sandstone probability model is built, and rock facies model is obtained by multi-point geostatistics theory; sedimentary microfacies model controlled by rock facies and braided-river-system is made; and eventually an effective sand body model is built by integrating sedimentary microfacies, effective sand body scale and reservoir properties distribution. The research method discussed in this paper has put geological constraints into the model as far as possible, enhanced the inter-well sand body predictability and improved the precision rate, thus it can provide a more reliable geological basis for gas reservoir development. Key words: Sulige gas field, tight sand gas, geological modeling, rock facies model, sedimentary microfacies model, multi-stage constraint, hierarchical facie

Innovation and prospect of geophysical technology in the exploration of deep oil and gas

The global situation of distribution, reserves and production of deep oil and gas are examined systematically, the progress and exploration achievement of onshore China deep geophysical technology are summarized, and the challenges and developing direction of deep geophysical technology are pointed out. Aiming at the exploration of deep onshore strata in China, the article analyzes the key geophysical problems, such as low signal-to-noise ratio, low resolution, low imaging accuracy and low amplitude-preservation, in the exploration of deep clastic, carbonate, and volcanic reservoirs, and presents the corresponding technical countermeasures such as wide-line large-array 2-D acquisition, wide-azimuth and high-density 3-D acquisition, anisotropic pre-stack depth migration (PSDM), reverse-time migration (RTM), complex structure modeling, and quantitative reservoir prediction. The analysis from two aspects, imaging of deep complicated structures and prediction of deep complicated reservoirs, shows that wide-frequency, amplitude-preservation, high-accuracy and information integration are the challenges to and key issues in the geophysical technology. It is pointed out that wide-frequency seismic acquisition, rock physical modeling of complex reservoirs, high-accuracy prestack amplitude-preservation imaging, comprehensive evaluation of complex reservoirs, non-seismic techniques, and drilling steering with seismic data are the key geophysical techniques needed to be developed in the future. Key words: geophysical technology, deep oil and gas exploration, deep complicated structure imaging, deep complicated reservoir predictio

Petroleum exploration and development practices of sedimentary basins in China and research progress of sedimentology

Based on the characteristics of recent discoveries in China, continental clastic reservoirs are the most important area for reserves and production growth. Significant progress has been made in exploration of carbonates reservoirs, for example, platform-margin reef complexes and platform interior reefs and banks. Volcanic reservoir exploration in sedimentary basins is feasible now. Mature oilfields with high water cut are predominant in the oil production in China. Some technological problems facing the stable production of mature oilfields have been solved by fine characterization of reservoirs, improving water flooding conditions, and EOR techniques. CNPC makes progress on studies of the sedimentary pattern of continental lacustrine basin shallow water delta, the origin and distribution of sandy debris flow, the mechanism and distribution prediction of deep favorable reservoirs, the sedimentary facies evaluation and reservoir prediction of low-porosity and low-permeability conglomerates, the lithofacies palaeogeography reconstruction of marine carbonates, the fine characterization of carbonates platform margins, the mechanism of carbonate reservoir superposition and rework, the origin classification of karst reservoirs, unconventional reservoir evaluation, reservoir improvement techniques, etc. These provide important theoretical and technical support for the exploration and development of oil and gas. 摘 要: 从近期中国油气发现的特点看，陆相碎屑岩仍是中国石油增储上产最主要的领域，碳酸盐岩勘探正处于大发现期，台缘礁滩复合体与台内礁、滩勘探成果显著，沉积盆地中火山岩储集层已成为油气勘探的现实领域。高含水老油田是中国油田开发的主体，持续的储集层精细表征研究和改善水驱条件、提高采收率技术攻关，突破了高含水老油田的稳产技术瓶颈。中国石油天然气集团公司在陆相湖盆浅水三角洲沉积模式建立、砂质碎屑流成因与分布、深部有利储集层发育机理与分布预测、低孔渗砂砾岩储集层成岩相评价与有利储集层预测，海相碳酸盐岩岩相古地理重建、碳酸盐岩台地边缘精细刻画与台地内部结构细化、碳酸盐岩储集层多期叠加改造机理、岩溶储集层成因分类，非常规储集层评价、开发储集层沉积学、沉积储集层研究新技术与新方法、储集层改造技术等领域不断取得新的进展，为今后油气勘探开发提供了重要的理论和技术支撑。图6表2参62 Key words: exploration and development, sedimentology, reservoir geology, prospec

Quantitative Classification of Forestry Division in Ceheng County

To determine the main functions of regional forest and focus of forestry construction to form the regional forestry economy with characteristics and ecological service system pattern with obvious advantages, we select some indicators on Ceheng County in Guizhou Province, such as natural geography, socio-economic conditions, ecological environment and forests status. Using the quantitative classification method combining factor analysis and system clustering, we conduct quantitative county level forestry division. The results show that first using factor analysis to establish factor analysis model, and then using a handful of factors loading large amounts of information to carry out system clustering, is an effective quantitative classification method of forestry division, which can not only overcome the weakness of previous division mainly focusing on qualitative analysis, but also eliminate the correlation between indicators in the conventional classification methods; through the factor analysis of 30 indicators influencing the forestry development of each township in Ceheng County, the factor analysis model is established, 6 factors loading 89.94 5% of information amount are used to conduct system clustering on 14 townships in Ceheng County, and finally Ceheng County can be divided into five zones. This study not only enriches the theory of forestry division, but also provides reference for the forestry planning in Guizhou and division of related industries

An analysis of major scientific problems and research paths of Gulong shale oil in Daqing Oilfield, NE China

After the preliminary basic research on the problems encountered during the production period of Gulong shale oil in the Songliao Basin, NE China, and the scientific exploration, the special characteristics of Gulong shale oil in terms of reservoir space, phase distribution, flow pattern, and mineral evolution are proposed. The main results are as follows : (1) The source of organic matter, mechanism of hydrocarbon generation and expulsion, and key factors affecting shale oil abundance; (2) The types and structural characteristics of the reservoir and their contribution to porosity and permeability; (3) The mineral origin and evolution of minerals and their influence on reservoir availability, sensitivity, and compressibility; (4) The rock mechanical characteristics and fracture propagation law of Gulong shale; (5) The shale oil products, phase change law and main control factors of adsorption and desorption conversion of Gulong shale oil; (6) The mechanism of shale oil-liquid, solid-liquid gas interaction and enhanced oil recovery. Three key research suggestions are proposed to realize the large-scale economic utilization of the Gulong shale oil as follows: (1) Deepen research on the mechanism of oil and gas generation and discharge, storage and transportation, to guide the selection of geological sweet spots of shale oil; (2) Deepen research on the compressibility and fracture initiation mechanism to support the selection of engineering sweet spots and optimization of engineering design; (3) Deepen research on the fluid interaction mechanism under reservoir conditions, os us to guide the optimization of development schemes and the selection of EOR technologies. A successful development of Gulong shale oil requires global experts and scholars to contribute multidisciplinary innovative ideas and technical ideas to solve production problems

Sedimentary diagenesis of rudist shoal and its control on reservoirs: A case study of Cretaceous Mishrif Formation, H Oilfield, Iraq

Based on the core, cast thin section, whole rock analysis, conventional physical properties and high pressure mercury intrusion test, the sedimentary diagenesis characteristics of rudist shoal in Cretaceous Mishrif Formation of H Oilfield, Iraq and its control on the reservoir were studied. The rudist shoal of the Mishrif Formation develops in the high-stand systems tract and is distributed in the high places of paleogeomorphology on the edge of platform with strong hydrodynamic force. According to the relative sea level changes, lithologic evolution and sedimentary structure characteristics of the rudist shoal, the single rudist shoal is divided into four lithologic sections: A, B, C and D, that is, low-angle cross-bedding pelletoids-rudist packstone, low-angle cross-bedding and parallel bedding arene-rudist grainstone, parallel bedding rudist gravel limestone, and horizontal bedding carbonaceous mudstone. The complete sedimentary sequence of a single rudist shoal is often disrupted. Several rudist shoals superimpose to form thick rudist shoal sediment. The single rudist shoal thickness and lithologic sections assemblage change regularly in vertical direction. The rudist shoal has the characteristics of “strong dissolution, weak cementation and strong compaction”, forming pore-type reservoir with intergranular pores, intergranular dissolved pores, mold pores, and dissolved pores. With mainly coarse pore throats larger than 5 μm, the reservoir is of medium-high porosity and high permeability. There is lithological reverse cycles inside single shoals and between single shoals, with content of mud crystals decreasing from the bottom to the top, dissolution increasing, cementation decreasing in strength, pore throats getting larger, and physical properties turning better. The rudist shoal of MB2-1 at the top of the high-stand systems tract has the largest thickness, moreover, subject to the strongest atmospheric freshwater leaching, this layer has the most significant dissolution and the largest pore throat, so it is the best reservoir of the Mishrif Formation. Key words: Iraq, Cretaceous, rudist shoal, sedimentary process, diagenetic evolution, reservoir characteristic