Aiming at the complexity of seismic gestation mechanism and spatial distribution, we hypothesize that the seismic data are composed of background earthquakes and anomaly earthquakes in a certain temporal-spatial scope...Aiming at the complexity of seismic gestation mechanism and spatial distribution, we hypothesize that the seismic data are composed of background earthquakes and anomaly earthquakes in a certain temporal-spatial scope. Also the background earthquakes and anomaly earthquakes both satisfy the 2-D Poisson process of different parameters respectively. In the paper, the concept of N-th order distance is introduced in order to transform 2-D superimposed Poisson process into 1-D mixture density function. On the basis of choosing the distance, mixture density function is decomposed to recognize the anomaly earthquakes through genetic algorithm. Combined with the temporal scanning of C value, the algorithm is applied to the recognition on spatial pattern of foreshock anomalies by exam-ples of Songpan and Longling sequences in the southwest of China.展开更多
目的前瞻性地评价超声内镜引导下细针抽吸活检(endoscopic ultrasound-guided fine needleaspiration,EUS-FNA)在胰腺疾病诊断中的价值及影响其诊断能力的潜在因素分析。方法 2010年9月至2011年8月间就诊于复旦大学附属中山医院内镜中心...目的前瞻性地评价超声内镜引导下细针抽吸活检(endoscopic ultrasound-guided fine needleaspiration,EUS-FNA)在胰腺疾病诊断中的价值及影响其诊断能力的潜在因素分析。方法 2010年9月至2011年8月间就诊于复旦大学附属中山医院内镜中心,经影像学诊断(CT或MRI)为胰腺病变、拟行EUS-FNA的44例患者连续性地纳入本研究。详细记录患者的年龄、性别、病变位置、病变大小、穿刺次数,评价是否获取足够样本供细胞学或组织病理学诊断及穿刺相关并发症等。结果 44例患者中,42例成功实行EUS-FNA(95.5%,42/44),病灶的平均最大直径为(44.7±18.2)mm。31例获得肉眼可见的组织条;意向性分析结果显示,34例穿刺样本(77.3%,34/44)足够用于细胞或组织病理学诊断,包括31例患者获得明确的细胞或组织病理学恶性肿瘤依据,3例诊断为胰腺炎症。病灶的位置、大小与穿刺成功率、明确病理学诊断的获得率无明显关系;而穿刺过程中获得肉眼可见组织样本病例的明确病理学诊断获得率明显高于未获得者(P=0.000)。2例患者于穿刺时发生穿刺点渗血(4.8%,2/42),通过电凝及止血夹处理好转。结论在胰腺疾病的诊断中,EUS-FNA具有良好的安全性和有效性。如何在安全的前提下获取更多的组织量用于病理学评估是提高EUS-FNA诊断能力的关键。展开更多
基金National Science Fund for Distinguished Young Scholars (40225004), The CAS Hundred Scholars Program.
文摘Aiming at the complexity of seismic gestation mechanism and spatial distribution, we hypothesize that the seismic data are composed of background earthquakes and anomaly earthquakes in a certain temporal-spatial scope. Also the background earthquakes and anomaly earthquakes both satisfy the 2-D Poisson process of different parameters respectively. In the paper, the concept of N-th order distance is introduced in order to transform 2-D superimposed Poisson process into 1-D mixture density function. On the basis of choosing the distance, mixture density function is decomposed to recognize the anomaly earthquakes through genetic algorithm. Combined with the temporal scanning of C value, the algorithm is applied to the recognition on spatial pattern of foreshock anomalies by exam-ples of Songpan and Longling sequences in the southwest of China.
