A Stable Q Compensated Reverse Time Migration Method Based on Excitation Amplitude Imaging Condition

The stability and efficiency, especially the stability, are generally concerned issues in Q compensated reverse time migration (Q-RTM). The instability occurs because of the exponentially boosted high frequency ambient noise during the forward or backward seismic wavefield propagation. The regularization and low-pass filtering methods are two effective strategies to control the instability of the wave propagation in Q-RTM. However, the regularization parameters are determined experimentally, and the wavefield cannot be recovered accurately. The low-pass filtering method cannot balance the selection of cutoff frequency for varying Q values, and may damage the effective signals, especially when the signal-to-noise ratio (SNR) of the seismic data is low, the Q-RTM will be a highly unstable process. In order to achieve the purpose of stability, the selection of cutoff frequency will be small enough, which can cause great damage to the effective high frequency signals. In this paper, we present a stable Q-RTM algorithm based on the excitation amplitude imaging condition, which can compensate both the amplitude attenuation and phase dispersion. Unlike the existing Q-RTM algorithms enlarging the amplitude, the exponentially attenuated seismic wavefield will be used during both the forward and backward wavefield propagation of Q-RTM. Therefore, the new Q-RTM algorithm is relative stable, even for the low SNR seismic data. In order to show the accuracy and stability of our stable Q-RTM algorithm clearly, an example based on Graben model will be illustrated. Then, a realistic BP gas chimney model further demonstrates that the proposed method enjoys good stability and anti-noise performance compared with the traditional Q-RTM with amplitude amplification. Compare the Q-RTM images of these two models to the reference images obtained by the acoustic RTM with acoustic seismic data, the new Q-RTM results match the reference images quite well. The proposed method is also tested using a field seismic data, the result shows the effectiveness of our proposed method.     

以肺动脉高压为首发表现的先天性中枢性低通气综合征临床特征和基因分析

目的探讨先天性中枢性低通气综合征(CCHS)的临床和基因变异特征。方法分析1例首发表现为不明原因肺动脉高压的CCHS患儿的临床资料,并总结国内外文献中CCHS病例的临床特点、致病机制和基因变异情况。结果11月龄女婴,主要表现为浮肿、尿少、低血压、嗜睡、发绀、抽搐及颅内压增高。B型脑利钠肽、丙氨酸氨基转移酶升高,凝血酶原时间延长。颅脑磁共振示右侧额叶出血;超声心动图示中重度肺动脉高压。靶向捕获二代测序未发现可能的致病基因。采用Sanger法验证示患儿PHOX 2 B基因第3外显子存在多聚丙氨酸重复扩展变异,基因型为20/25。患儿入院后采用无创通气,睡眠时呼吸浅慢、微弱,伴血氧下降;血气分析提示二氧化碳潴留。随后改用夜间无创通气、降肺压药物治疗。复查肺动脉压力明显下降,生命体征稳定。随访至24月龄,夜间只需较低压力水平的无创通气,生长发育无异常。结论对于不明原因的肺动脉高压伴撤机困难患儿,需警惕CCHS。疑诊者应尽早针对CCHS相关基因进行靶向捕获二代测序及PHOX 2 B基因Sanger法验证。早期给予无创通气有望改善预后。     

ELAM-1在鼻咽癌裸鼠移植瘤中的表达及其与转移的关系

目的 建立裸鼠鼻咽癌转移模型并探讨 E-选择素（ELAM-1）与鼻咽癌转移的相关性。方法 将鼻咽癌5-8F细胞悬液注射于裸鼠左后肢爪垫，观察裸鼠状态、成瘤情况并测量裸鼠体重及移植瘤长短径；采用连续病理切片苏木精-伊红染色观察移植瘤及转移情况，将16只人鼻咽癌荷瘤裸鼠分为转移组和非转移组；采用免疫组织化学法检测两组移植瘤组织中ELAM-1的表达。 结果 16只裸鼠均成瘤，成瘤率为100.0%，其中10只裸鼠出现转移瘤，转移率为62.5%。建模前，两组裸鼠体重差异无统计学意义［（13.83±0.56）g vs （14.62±0.30） g，t=1.026，P=0.071］。建模后4~7周，裸鼠瘤体体积呈指数增长，且转移组移植瘤增长速度较非转移组快，非转移组裸鼠瘤体体积小于转移组［（198.91 ± 163.29） mm³ vs （268.76 ±174.31） mm³，t=4.376，P=0.005］。ELAM-1在鼻咽癌裸鼠移植瘤、淋巴结转移灶及远处转移灶中的表达均为阳性，主要表达于细胞膜。转移组移植瘤光密度值高于非转移组（0.4497±0.0705 vs 0.0435±0.0082，t=4.388，P＝0.001）。结论 本研究成功构建稳定性好、转移率高的鼻咽癌裸鼠移植瘤转移模型，且ELAM-1在裸鼠移植瘤中高表达，可促进鼻咽癌裸鼠移植瘤生长和转移。     

黄蜀葵花治疗2型糖尿病肾病早期蛋白尿40例临床观察

目的:探讨黄蜀葵花干预2型糖尿病肾病(T2DKD)早期蛋白尿的临床疗效.方法:将80例T2DKD早期患者随机分为治疗组和对照组,每组各40例.对照组给予西医常规治疗,治疗组在对照组的基础上加用黄蜀葵花片治疗.2组疗程均为6个月.观察2组治疗前后血糖、血脂、肝肾功能、肾小球滤过率(eGFR)、尿白蛋白与尿肌酐比值(UACR)的变化.结果:治疗组脱落2例,对照组脱落1例.2组血压、血糖、血脂、肝肾功能、eGFR、合并用药情况治疗后组间比较,差异均无统计学意义(P＞0.05),而UACR及UACR下降程度治疗后组间比较,差异均有统计学意义(P＜0.05).结论:黄蜀葵花可明显减轻T2DKD早期患者尿蛋白水平,该疗效不依赖于血压和糖脂代谢的变化.     

益气化瘀解毒方对MRP、GST-π和Topo Ⅱ基因在Sorafenib获得性耐药人肝癌QGY7702细胞表达的干预研究

目的探讨益气化瘀解毒方干预后对Sorafenib获得性耐药人肝癌QGY7702细胞(QGY7702/Sora)增殖及MRP、GST-π和Topo Ⅱ基因表达的影响。方法培养QGY7702/Sora细胞和QGY7702细胞,利用Cell Counting Kit-8(CCK-8)法检测Sorafenib对细胞的半数抑制率浓度(IC50值),计算耐药指数RI;观察益气化瘀解毒方对耐药细胞的增殖影响;采用荧光定量PCR检测药物干预前后2种细胞中MRP、GST-π和Topo Ⅱ基因表达水平。结果亲本细胞和耐药细胞Sorafenib的IC50值分别为(7.993±0.522)μmol/L和(19.651±1.216)μmol/L,RI约为2.5。益气化瘀解毒方可抑制耐药细胞的增殖活性。2种细胞的MRP、GST-π、Topo Ⅱ表达量无明显差异(P>0.05)。Sorafenib组可促进耐药细胞MRP 、GST-π基因的过表达(P<0.05),益气化瘀解毒方组可抑制GST-π基因的过表达(P<0.01),且联合Sorafenib可显著提高Topo Ⅱ基因的表达量(P<0.01)。结论 QGY7702/Sora细胞MRP、GST-π和Topo Ⅱ的表达水平与亲本细胞无显著差异。耐药细胞对Sorafenib敏感性降低与MRP、GST-π过表达相关,而益气化瘀解毒方拮抗Sorafenib耐药与抑制GST-π过表达相关。     

非活动性结核性胸膜炎与活动性结核性胸膜炎的CT扫描影像特征分析

目的: 探讨非活动性结核性胸膜炎与活动性结核性胸膜炎CT扫描影像表现。方法: 对2012年6月1日至2021年3月30日在首都医科大学附属北京胸科医院就诊的单纯非活动性结核性胸膜炎患者68例和同期活动性结核性胸膜炎44例的CT扫描影像表现进行比较。结果: (1) 68例非活动性结核性胸膜炎患者 CT扫描影像表现中胸膜粘连62例(91.2%),胸膜有钙化者28例(41.2%),叶间裂受累22例(32.4%),胸腔积液12例(17.6%),包裹性胸腔积液8例(11.8%)。(2)44例活动性结核性胸膜炎患者CT扫描影像表现中胸膜粘连30例(68.2%),未见胸膜钙化,叶间裂受累32例(72.7%),胸腔积液43例(97.7%),包裹性胸腔积液26例(59.1%)。(3)非活动性与活动性结核性胸膜炎CT扫描影像比较:胸膜粘连、胸膜钙化发生率高,差异均有统计学意义(χ²=9.630,P=0.002;χ²=23.737,P=0.000);叶间裂受累、胸腔积液、包裹性胸腔积液的发生率低,差异均有统计学意义(χ²=12.692,P=0.000;χ²=68.548,P=0.000;χ²=28.301,P=0.000)。结论: 非活动性结核性胸膜炎的CT扫描影像与活动性结核性胸膜炎比较胸膜粘连、胸膜钙化的发生率高,胸腔积液、包裹性胸腔积液、叶间裂受累的发生率低。识别非活动性和活动性结核性胸膜炎的CT扫描影像特点,对患者临床治疗有指导意义。     

Analysis of early mortality and related risk factors in maintenance hemodialysis patients

Objective To analyze the early mortality and related risk factors of new hemodialysis patients in Zhejiang province, and provide basis for reducing the death risk of hemodialysis patients. Methods The early mortality and related factors of new hemodialysis patients from January 1, 2010 to June 30, 2018 were retrospectively analyzed using the database of Zhejiang province hemodialysis registration. The early mortality was defined as death within 90 days of dialysis. Cox regression model was used to analyze the related risk factors of the early mortality in hemodialysis patients. Results The mortality was the highest in the first month after dialysis (46.40/100 person year), and gradually stabilized after three months. The early mortality was 25.33/100 person year. The mortality within 120 days and 360 days were 21.40/100 person year and 11.37/100 person year, respectively. The elderly (≥65 years old, HR=1.981, 95%CI 1.319-2.977, P＜0.001), primary tumor (HR=3.308, 95%CI 1.137-5.624, P=0.028), combined with tumors (not including the primary tumor, HR=2.327, 95%CI 1.200-4.513, P=0.012), temporary catheter (the initial dialysis pathway, HR=3.632, 95%CI 1.806-7.307, P＜0.001), lower albumin (＜30 g/L, HR=2.181, 95%CI 1.459-3.260, P＜0.001), lower hemoglobin (every 0.01 g/L increase, HR=0.861, 95%CI 0.793-0.935, P=0.001), lower high density lipoprotein (＜0.7 mmol/L, HR=1.796, 95%CI 1.068-3.019, P=0.027) and higher C reactive protein (≥40 mg/L, HR=1.889, 95%CI 1.185-3.012, P=0.008) were the risk factors of early death for hemodialysis patients. Conclusions The early mortality of hemodialysis patients is high after dialysis, and gradually stable after 3 months. The elderly, primary tumor, combined with tumors, the initial dialysis pathway, lower albumin, lower hemoglobin, lower high density lipoprotein and higher C reactive protein are the risk factors of early death for hemodialysis patients.