A Bipolar-Bisection Piecewise Encoding Scheme for Multi-Source Reverse Time Migration

Conventional shot-record reverse time migration (RTM) suffers from a high computational burden when dealing with massive data. The computational cost of RTM can be reduced by shot-encoding techniques, and plane-wave encoding is a commonly used and effective shot-encoding scheme. However, plane-wave encoding requires long time padding to avoid information loss, which decreases the efficiency of the time-domain wavefield extrapolator, and the time padding becomes longer with the increasing distance between multiple sources. The piecewise plane-wave encoding scheme cuts multiple sources into several segments prior to implementing plane-wave encoding, hence reduces the time padding, but brings new crosstalk due to the mutual interference between shots in different source segments. We suppress the crosstalk artifacts by a new bipolar-bisection amplitude encoding method, in which half of the encoding array of each migration is different from that of any other migrations to reduce the number of crosstalk terms with as few migrations as possible. We embed the bipolar-bisection method into piecewise plane-wave encoding. Compared with plane-wave encoding, the proposed scheme requires considerably shorter time padding and thus works more efficiently and can generate a qualified imaging result. The feasibility of the proposed method is tested on the 2D SEG/EAGE salt model and the Marmousi model.     

Improving migrant well-being: spontaneous movement as a way to increase the creativity,spontaneity and welfare of migrants in Glasgow

ABSTRACT

This article describes the experience of two years of working with migrants residing in the city of Glasgow, Scotland. Three different groups, with participants from Asia, Africa, Latin America and Europe, students, migrants and asylum seekers, converged in three different spaces and frameworks. A total of 51 participants, six men and 41 women between 20 and 50 years of age, took part in spontaneous movement workshops to promote their health, body awareness and well-being, the strengthening of affective bonds and creativity. The impact of the sessions was assessed through an anonymous survey, a semi-structured interview and a facilitator’s diary of the sessions. The settings of the three groups were not identical and, thus, did not allow for a comparison between them. However, the results showed that the sessions helped participants to increase their sense of well-being and confidence, facilitate their integration process and strengthen their bonds with other participants.     

miR-182靶向NUMB调控结直肠癌细胞增殖、迁移和侵袭的机制研究

目的:研究miR-182对结直肠癌细胞HT-29增殖、迁移和侵袭的影响，并探讨其机制。方法:运用qRT-PCR检测人正常结肠上皮细胞HCoEpiC、结直肠癌细胞HT-29中miR-182、NUMB的表达；将anti-miR-con组（转染anti-miR-con）、anti-miR-182组（转染anti-miR-182）、pcDNA组（转染pcDNA）、pcDNA-NUMB组（转染pcDNA-NUMB）、anti-miR-182+si-con组（anti-miR-182和si-con共转染）、anti-miR-182+si-NUMB组（anti-miR-182和si-NUMB共转染）均用脂质体法转染HT-29细胞；Western blot检测各组细胞中NUMB的蛋白表达；Transwell检测各组细胞的迁移和侵袭；MTT法检测各组细胞的增殖；双荧光素酶报告基因检测实验检测各组细胞的荧光素酶活性。结果:与人正常结肠上皮细胞HCoEpiC相比，结直肠癌细胞HT-29中miR-182表达显著升高，NUMB表达显著降低（P<0.05）；抑制miR-182、过表达NUMB均可下调HT-29细胞的增殖、迁移、侵袭；NUMB是miR-182的靶标。敲减NUMB可逆转抑制miR-182对HT-29细胞增殖、迁移、侵袭的下调作用。结论:miR-182可促进结直肠癌细胞的增殖、迁移、侵袭，其机制可能与靶向NUMB有关，将可为miR-182靶向治疗结直肠癌提供依据。     

柴胡皂苷D通过抑制EMT和细胞干性抑制人结直肠癌细胞SW480的迁移和侵袭

目的:研究柴胡皂苷D（saikosaponin-D，SSD）对人结直肠癌细胞SW480迁移和侵袭能力的影响，并初步探讨SSD抑制细胞迁移和侵袭的机制。方法:MTT检测SSD对细胞增殖的影响。划痕实验和Transwell迁移实验研究SSD对细胞迁移能力的影响。Transwell侵袭实验研究SSD对细胞侵袭能力的影响。Western-blot检测SSD对上皮间质转化（epithelial mesenchymal transformation，EMT）相关蛋白（E-cadherin、N-cadherin和Vimentin）表达的影响。克隆球形成实验研究SSD对细胞干性的影响。结果:在划痕实验和Transwell迁移实验中，SSD显著抑制SW480的迁移能力（P<0.05）。在Transwell侵袭实验中，SSD显著抑制SW480的侵袭能力（P<0.05）。SSD处理后，细胞E-cadherin的表达增高，N-cadherin和Vimentin的表达降低（P<0.05），同时SSD抑制SW480细胞克隆球的形成（P<0.05）。结论:柴胡皂苷D通过抑制EMT和细胞干性抑制人结直肠癌细胞SW480的迁移和侵袭。     

miR-194靶向EZH2抑制甲状腺癌细胞增殖、迁移和侵袭

目的:研究miR-194、EZH2对甲状腺癌细胞增殖、迁移和侵袭的影响，并探讨其作用机制。方法:采用qRT-PCR法检测甲状腺癌组织、癌旁正常组织及甲状腺癌细胞和正常甲状腺上皮细胞中miR-194和EZH2的mRNA表达；将miR-194（转染miR-194 mimics）、miR-NC（未转染细胞）、inhibitor-NC（转染空inhibitor）、miR-194 inhibitor（转染miR-194 inhibitor）、si-EZH2（转染si-EZH2）、miR-194+Vector（miR-194 mimics和pcDNA 3.1共转染）、miR-194+EZH2（miR-194 mimics和pcDNA 3.1-EZH2共转染）均以脂质体法转染到SW579、IHH-4细胞；Western blot检测细胞中EZH2的蛋白表达；MTT法检测细胞的增殖；Transwell检测细胞的迁移和侵袭；双荧光素酶报告基因检测实验检测细胞荧光素酶活性。结果:与正常组相比，甲状腺癌组EZH2的表达显著升高，miR-194的表达显著降低；与人正常甲状腺上皮细胞相比，甲状腺癌细胞中EZH2表达显著升高，miR-194的表达显著降低，且过表达miR-194和沉默EZH2均可抑制甲状腺癌细胞增殖、迁移和侵袭。EZH2为miR-194的靶标，且EZH2可逆转过表达miR-194对甲状腺癌细胞增殖、迁移和侵袭的抑制作用。结论:miR-194可抑制甲状腺癌细胞的增殖、迁移和侵袭，可能与靶向EZH2有关，将可为miR-194靶向治疗甲状腺癌提供依据。     

原肌球蛋白4在胃癌细胞迁移、侵袭和转移中的作用

目的:探索原肌球蛋白4（Tropomyosin4,TPM4）在胃癌细胞的迁移、侵袭和转移中的作用。方法:利用Real-time PCR、Western Blot及免疫荧光，检测原肌球蛋白4在不同胃癌细胞系及正常胃上皮细胞中的表达情况；利用免疫组化，检测原肌球蛋白4在胃癌组织及癌旁正常组织中的表达情况；利用慢病毒技术，在GC9811-P细胞中，分别转染LV-TPM4、shRNA-TPM4及对照空载体；通过Transwell和体内实验，检测胃癌细胞迁移、侵袭和转移。结果:Real-time PCR、Western Blot及免疫组化结果显示，原肌球蛋白4在胃癌细胞系及胃癌组织中的表达降低；上调原肌球蛋白4的表达后，抑制胃癌细胞的迁移、侵袭和转移；下调原肌球蛋白4的表达后，促进胃癌细胞的迁移、侵袭和转移（P<0.05）。结论:原肌球蛋白4抑制胃癌细胞的迁移、侵袭和转移。     

蒿甲醚对胃癌细胞增殖、侵袭和迁移的抑制作用研究

目的:研究蒿甲醚对胃癌细胞（AGS和SGC-7901）的增殖、侵袭以及迁移的影响并探讨其分子机制。方法:分别利用MTT、集落形成试验检测胃癌细胞的活力和生长；流式细胞技术检测胃癌细胞的凋亡率；利用细胞侵袭和划痕愈合试验检测胃癌细胞的侵袭和迁移；Western blot检测相关蛋白的表达水平。结果:蒿甲醚（0~800 μmol/L）能够浓度和时间依赖性的抑制 AGS和SGC-7901细胞的增殖（P＜0.05）。集落形成试验以及流式细胞术结果显示蒿甲醚（400 和 600 μmol/L）能够抑制AGS和SGC-7901细胞的生长以及促进细胞凋亡（P＜0.05）。细胞侵袭和划痕愈合试验发现蒿甲醚（400 和 600 μmol/L）能够抑制AGS和SGC-7901细胞的侵袭和迁移（P＜0.05）。Western blot结果显示蒿甲醚(400 和 600 μmol/L)能够增加AGS和SGC-7901细胞的cleaved caspase-3,cleaved caspase-9以及Bax的蛋白水平（P＜0.05）；同时能够抑制N-cadherin 和vimentin的蛋白表达并促进E-cadherin蛋白的表达。结论:蒿甲醚可以显著抑制胃癌细胞的增殖、侵袭以及迁移，其机制可能是与促进细胞凋亡以及抑制上皮间质转化有关。