Subsequent chemotherapy reverses acquired tyrosine kinase inhibitor resistance and restores response to tyrosine kinase inhibitor in advanced non-small-cell lung cancer

<p>Abstract</p> <p>Background</p> <p>Patients with advanced or metastatic non-small cell lung cancer (NSCLC) can develop acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib. Here, we report the successful treatment with alternating chemotherapy and TKIs of two cases of advanced NSCLC who developed resistance to TKI.</p> <p>Case presentation</p> <p>Two patients with advanced or metastatic NSCLC were treated with palliative chemotherapy followed by erlotinib/gefitinib. When TKI therapy failed, two cycles of chemotherapy were provided, which were followed by re-challenge with erlotinib or gefitinib.</p> <p>Conclusion</p> <p>NSCLC patients with acquired TKI resistance should be managed aggressively whenever possible. Subsequent chemotherapy and target treatment is one of the reasonable choices for those with an initial dramatic clinical response with erlotinib/gefitinib treatment. Further studies are warranted to substantiate the association of erlotinib /gefitinib treatment with the efficacy of NSCLC patients with acquired TKI failure.</p

Radiation and Annealing Effects on GaN MOSFETs Irradiated by 1 MeV Electrons

In this paper, the 650 V N-channel GaN MOSFETs are chosen as the research object to study the radiation and annealing effects under 1 MeV electron irradiation. The output, transfer, and breakdown characteristics are measured before and after electron irradiation. The experimental results show the variation of the I-V curves after irradiation, which is related to the increased conductivity due to the generation of an oxide charge in the GaN MOSFETs. However, the gradual formation of the interface trapped charge offsets the effect of the oxide charge, which decreases the conductivity of the GaN MOSFETs and the drain-source current. The long-term annealing at room temperature degrades the interface trapped charges, leading to the restoration of the I-V characteristics. After room temperature annealing, the breakdown voltage is still higher than the unirradiated level, and this is because the displacement defects caused by electron irradiation cannot be recovered at room temperature

Automatic demarcation of sequence stratigraphy using the method of well logging multiscale data fusion

Strata division with well logging utilizes the abrupt changing points or regions of signals, while the changing law of the wavelet modulus maxima under different scales can exactly describe the position and modality of the changing points. Based on the idea of reconstruction of wavelet modulus maxima, the well logging data fusion method built on the multiscale edge detection principle is put forward and is applied to the quantitative demarcation of sequence stratigraphy. For case study, single logging curve and multiscale fusion curve in well A in Shengtuo Oilfield are processed by quadric spline wavelet and thereby sequence boundaries on different scales can be detected. The result shows: by demarcating sequence stratigraphic units with the multiscale fusion curve analysis, better effect could be obtained. The energy accumulation and distribution on the wavelet time-frequency graph could clearly reflect the boundaries and cycle types of parasequences and parasequence sets. All these researches provide a completely new method for the quantitative demarcation of sequence and its inner depositional features. Key words: logging curve, wavelet transform, multiscale, data fusion, sequence stratigraph

Petroleum geological conditions and exploration importance of Proterozoic to Cambrian in China

The discovery of the giant Anyue gas field in Sichuan Basin gives petroleum explorers confidence to find oil and gas in Proterozoic to Cambrian. Based on the reconstruction of tectonic setting and the analysis of major geological events in Mesoproterozoic-Neoproterozoic, the petroleum geological conditions of Proterozoic to Cambrian are discussed in this paper from three aspects, i.e. source rocks, reservoir conditions, and the type and efficiency of play. It is found that lower organisms boomed in the interglacial epoch from Mesoproterozoic-Neoproterozoic to Eopaleozoic when the organic matters concentrated and high quality source rocks formed. Sinian-Cambrian microbial rock and grain-stone banks overlapped with multiple-period constructive digenesis may form large-scale reservoir rocks. However, because of the anoxic event and weak weathering effect in Eopaleozoic-Mesoproterozoic, the reservoirs are generally poor in quality, and only the reservoirs that suffered weathering and leaching may have the opportunity to form dissolution-reconstructed reservoirs. There are large rifts formed during Mesoproterozoic-Neoproterozoic in Huabei Craton, Yangtze Craton, and Tarim Craton in China, and definitely source rocks in the rifts, while whether there are favorite source-reservoir plays depends on circumstance. The existence of Sinian-Cambrian effective play has been proved in Upper Yangtze area. The effectiveness of source-reservoir plays in Huabei area depends on two factors: (1) the effectiveness of secondary play formed by Proterozoic source rock and Paleozoic, Mesozoic, Cenozoic reservoir rocks; (2) the matching between reservoirs formed by reconstruction from Mesoproterozoic- Neoproterozoic to Eopaleozoic and the inner hydrocarbon kitchens with late hydrocarbon generation. As for Tarim Basin, the time of Proterozoic and the original basin should be analyzed before the evaluation of the effective play. To sum up, Proterozoic to Cambrian in the three craton basins in China is a potential exploration formation, which deserves further investigation and research. Key words: Proterozoic, Cambrian, tectonic setting, major geological events, interglacial epoch, source rock, microbial rock, intracratonic rift, pla

The multi-staged “golden zones” of hydrocarbon exploration in superimposed petroliferous basins of onshore China and its significance

The hydrocarbon generation model proposed by Tissot et al. points out the temperature and depth of “liquid HC window”, which has become a “golden zone” for hydrocarbon exploration. It has been proved by exploration that multi-staged “golden zones” for hydrocarbon exploration is commonly developed in the superimposed petroliferous basins of onshore China. There are three factors for the formation of multi-staged “golden zones” of HC exploration in the superimposed basins: (1) source kitchens developed with multi-periods and multi-centers which have verified to lead multi-stages of HC generation with large scale, (2) multi-staged reservoirs develop with large scale, (3) hydrocarbon accumulations occur with the multi-periods and late effectiveness. The conventional source kitchens, dispersed liquid HC-cracking gas kitchens and effective reservoirs with large scale join together to control the distribution of “golden zones” in timing and space. Explorational “golden zones” have the characteristics of inherited stacking and lateral variation. Paleo-highs, paleo-slopes, paleo-platform margins, and multi-period inherited fault zones control the distribution of hydrocarbons in the explorational “golden zones”. The concept of multi explorational “golden zones” helps to deepen the knowledge of new hydrocarbon distributional regularity which revealed recently in China. It shows that there exist economic resources in the deep section of the superimposed basins of onshore China. The hydrocarbon discovery history in the superimposed petroliferous basins has the feature of multi-peaks of proven reserve increase and lasting a quite long, which indicates a huge potential for future exploration. Key words: superimposed basin, multi-staged HC exploration golden zone, conventional source kitchen, dispersed hydrocarbon- cracking gas kitchen, large scaled reservoir rock, multi-period hydrocarbon accumulation, deep section, China onshor

A Prediction Model of Oil Cracked Gas Resources and Its Application in the Gas Pools of Feixianguan Formation in NE Sichuan Basin, SW China

The prediction of oil cracked gas resources is necessary and urgent in the gas exploration of these basins at high to over stage in China. A marine crude oil sample was pyrolyzed using sealed gold tubes system in our study. The pyrolysates including gas, liquid, and solid were quantitatively analyzed. Based on the pyrolysis data and kinetic calculation, the yield correlativity among gas, liquid, and solid products was regressed with high correlative coefficients to establish a prediction model suitable for the resource estimation of oil cracked gas. The verification formula for this model was also established on the principle of mass conservation. The affecting factors and the application preconditions of this model were discussed. Finally the model was extrapolated to the prediction of oil cracked gas resources of Feixianguan formation in NE Sichuan basin, SW China. The prediction value of oil cracked resources is about 6.84×1012 m3, and generation intensity of oil cracked gas is about 97.5×108 m3/km2, and the paleo-oil reserves is about 97×108 t. The verifying value for this prediction is approximately equal to 1, indicating the model is reliable in the resource estimation of oil cracked gas

Assessment on gas accumulation potential and favorable plays within the Xu-1, 3 and 5 Members of the Xujiahe Formation in the Sichuan Basin

Natural gas exploration and discovery of hydrocarbons in the Xujiahe Formation in the Sichuan Basin are mainly concentrated in the Xu-2, 4 and 6 Members. The discovered gas reservoirs are characterized by a low filling degree, high water saturation in lower intervals, low levels of produced reserves and a limited number of gas-bearing reservoirs. The Xu-1, 3 and 5 Members are identified as source rocks. Based on the study of natural gas accumulations and several gas production wells in the Xu-1, 3 and 5 Members, this paper proposes that large scale sand bodies are developed in the Xu-1, 3 and 5 Members in the northwest, southwest and central parts of the Sichuan Basin. In each member, the favorable gas bearing area is about 5 000-11 000 km2, the reservoir rocks have good continuity with single layer extensions of up to 15-20 km. It is believed that these sand bodies have favorable conditions for gas accumulation within source kitchens to form lithologic or structural-lithologic gas reservoirs and have better accumulation potential and higher gas-bearing abundance than that of the Xu-2, 4 and 6 Members. Exploration practices have revealed that economic gas reserves may be generated. It is suggested that more efforts be made to study the gas accumulation conditions in the Xu-1, 3 and 5 Members (especially the Xu-3 and Xu-5 Members) and more exploration work be conducted in these strata. 摘要: ：目前四川盆地须家河组天然气藏勘探和发现主要集中于须二、四、六段，气藏总体表现出充满度不高、低部位含水饱和度偏高、储量动用比例偏低、储集层含气范围有限的特点，须一、三、五段则被作为烃源岩。在对须一、三、五段进行成藏条件研究和已知出气点解剖分析的基础上，提出川西北、川西南和川中部分地区须一、三、五段发育规模较大的砂体，各段有利含气面积约5 000～11 000 km2，储集层连续性较好，单层延伸长度达15～20 km，具备源内成藏的有利条件，可形成岩性或构造-岩性圈闭气藏，比须二、四、六段的成藏潜力和丰度更好，经勘探可形成工业规模的天然气储量，今后应该加强上述地区须一、三、五段源内天然气成藏研究与勘探力度，尤其是须三和须五段。图8表4参19 Key words: accumulation inside source, favorable play, Xujiahe Formation, Sichuan Basi