Alantolactone exerts anti-proliferative and apoptotic effects on BGC823 and SGC7901 cells via activation of p38MAPK and inhibition of NF-κB signaling pathway

Purpose: To investigate the anti-proliferative and apoptotic influences of alantolactone on gastric carcinoma (GC) cell lines, and the mechanism(s) involved. Methods: Human gastric cancer cell line (BGC823) and gastric adenocarcinoma lymph node metastasis cell line (SGC7901) were maintained in Ham’s F12 medium supplemented with 10 % heatinactivated fetal bovine serum (FBS). In each group of cancer cell line, 5 groups of cells were used: control and four alantolactone groups which were treated with increasing concentrations of alantolactone (5 - 30 μM) for varying periods. Proliferation was determined using MTT assay, while realtime quantitative polymerase chain reaction (qRT-PCR) was used to assay the expressions of apoptosis- and metastasis-related genes. The expressions of p38MAPK and nuclear transcription factor-κB (NF-κB) in BGC823 and SGC7901 cells were measured with Western blotting. Results: Phosphorylated protein (p-p38 protein) expression was significantly higher in both groups of GC cells, relative to control (p < 0.05). The expressions of NF-κB in plasma protein were markedly higher in both groups of GC cells than in control group, but the corresponding expressions in nuclear protein were significantly lower in both groups of GC cells, relative to control (p < 0.05). Conclusion: Alantolactone exerts anti-proliferative and apoptotic effects on BGC823 and SGC7901 cells via mechanisms involving activation of the p38MAPK, and inhibition of the NF-κB signaling pathways. Thus, alantolactone may be a new and effective anti-gastric cancer drug

A fine assessment technology for medium-high exploration degree plays

The current evaluation methods mainly focus on plays without hydrocarbon discoveries. By integrating three techniques, i.e., spatial quantitative prediction technology of hydrocarbon bearing probability, overlapping processing technology for multi-layer spatial hydrocarbon bearing probability, petroleum resources abundance fractal simulation restricted by corresponding spatial hydrocarbon bearing probability, a new fine evaluation method was put forward. This method, based on spatial grids and combining planar and vertical evaluation results, focuses on the assessment of multi-layer plays. Compared with the present methods, it has advantages such as comprehensive assessment, precise processing results, comprehensive data collection and application, exploration effectiveness. By this Method, 38 secondary structural belts in the middle-upper exploration formations in the Turpan-Hami Basin were evaluated. Favorable drilling areas in each belts were pointed out based on the spatial probability of hydrocarbon bearing. Their corresponding geological favorability index and residual oil resources revealed that the Shengbei, Huoyanshan, Lukeqin, Shanle Structural Belts are the most favorable belts for exploration. 摘 要: 现行的区带评价方法主要针对尚无油气发现的区带，在剖析其局限性的基础上，将含油气概率空间定量预测技术、多层系空间含油气概率叠合处理技术、含油气概率约束下的油气资源丰度空间定量模拟技术紧密结合，提出一种平面与纵向相结合、基于空间网格的多层系区带精细评价新方法。相对于现行的区带评价方法，具有评价综合性、评价及评价结果精细性、资料应用与信息采集全面性、应用实效性等优点。采用该方法对吐哈盆地中上部层系38个二级构造带进行评价，根据空间含油气概率评价结果，明确了各构造带内部有利钻探区；依据各区带地质评价值、待发现资源量评价值进行二因素综合排队优选，指出胜北、火焰山、鲁克沁、鄯勒等构造带是下步勘探的最有利构造带。图6表1参25 Key words: play, spatial probability of hydrocarbon bearing, spatial resources abundance, multi-layer overlapping process, Turpan-Hami Basin, favorable secondary structural belt

Modeling of the tight sandstone gas accumulation for the Xujiahe Formation, Hechuan-Tongnan Area, Sichuan Basin

The tight sandstone gas accumulation is mainly driven by overpressure arising from the gas generation in source rocks. This paper proposes a quantitative computation model for the pressurization from gas generation in source rocks, establishes a dynamic equilibrium equation and a modeling process for tight sandstone gas accumulation, and simulates the gas generation quantity and source rock overpressure history in the Hechuan-Tongnan area of the Sichuan Basin. The modeling reveals that: (1) The gas generation intensity determines the degree of pressurization from gas generation, whereas the reservoir property determines the distribution of gas reservoirs; the conventional gas reservoir is complementary with the tight sandstone gas reservoir in terms of horizontal and vertical distribution, the former is mainly distributed at the top of reservoir with porosity over 7% on local structural highs while the latter is mainly distributed at the bottom of reservoir on local structural lows near source rocks of large gas generation quantity. (2) During the uplifting process from the maximum burial depth (65 Ma) to the current burial depth, because of the pressure drop of formation water and the increase of gas-water pressure difference, the tight sandstone gas migrates farther and increases in accumulation quantity; however, the conventional gas does not migrate basically and has no increase in accumulation quantity; (3) The quantity of the tight sandstone gas in the T3x2 is 5.9 times that of the conventional gas, and the undiscovered resource is mainly tight sandstone gas distributed in northeast of Hechuan, and north and southeast of Tongnan. 摘要: ：烃源岩生气产生的超压是致密砂岩气藏成藏的主要驱动力，提出烃源层生气增压定量计算模型，建立致密砂岩气藏动力平衡方程，制定致密砂岩气成藏模拟流程，并模拟了四川盆地合川—潼南地区须一段生气量及其引起的烃源岩超压史。模拟结果证实：①烃源层生气强度决定生气增压的大小，储集层物性决定气藏的分布，常规气藏与致密砂岩气藏在平面和纵向上的分布均具有互补的特点，前者主要分布于孔隙度大于7%的局部构造高点；后者主要分布于孔隙度较低的构造相对低部位且靠近生气量大的烃源层；②从最大埋深（距今65 Ma）到现今的抬升过程中，由于地层水压力降低，气水压差增大，致密砂岩气运移更远，聚集量增大，但常规气基本不发生运移，聚集量也未增大；③须二段致密砂岩气量是常规气量的5.9倍，未发现资源主要为致密砂岩气，分布在合川的东北部、潼南北部和潼南的东南部等地区。图12表2参37 Key words: tight sandstone gas, accumulation modeling, formation pressure, continuous gas accumulation, resource assessmen

In vitro selection of DNA aptamer against abrin toxin and aptamer-based abrin direct detection

Abrin toxin as the target protein, belongs to class II ribosome-inactivating proteins family, has high toxicity to eukaryotic cells. Here, we firstly report the DNA aptamers, isolated by in vitro selection, recognize abrin toxin with high affinity and specificity, and have the advantage of no cross-reaction with structure-similar protein ricin toxin over antibodies. Then, a highly selective and sensitive aptamer-based abrin assay was established using a molecular light switching reagent [Ru(phen)(2)(dppz)](2+) with a limit of detection of 1 nM and a wide linear range from 1 to 400 nM with the correlation coefficient of 0.993. This assay can be successfully directly performed not only in physiological buffer but also in more complicated biological matrix, such as diluted serum. (c) 2006 Elsevier B.V. All rights reserved

Nanoscale Insights into the Hydrogenation Process of Layered α‑MoO₃

The hydrogenation process of the layered α-MoO₃ crystal was investigated on a nanoscale. At low hydrogen concentration, the hydrogenation can lead to formation of H_<i>x</i>MoO₃ without breaking the MoO₃ atomic flat surface. For hydrogenation with high hydrogen concentration, hydrogen atoms accumulated along the <101> direction on the MoO₃, which induced the formation of oxygen vacancy line defects. The injected hydrogen atoms acted as electron donors to increase electrical conductivity of the MoO₃. Near-field optical measurements indicated that both of the H_<i>x</i>MoO₃ and oxygen vacancies were responsible for the coloration of the hydrogenated MoO₃, with the latter contributing dominantly. On the other hand, diffusion of hydrogen atoms from the surface into the body of the MoO₃ will encounter a surface diffusion energy barrier, which was for the first time measured to be around 80 meV. The energy barrier also sets an upper limit for the amount of hydrogen atoms that can be bound locally inside the MoO₃ <i>via</i> hydrogenation. We believe that our findings has provided a clear picture of the hydrogenation mechanisms in layered transition-metal oxides, which will be helpful for control of their optoelectronic properties <i>via</i> hydrogenation