断层性能、地面地质和三维速度模式之间的关系

对围绕着加利福尼亚的五个大地震地区的三维 P 波速度模式的研究,导致了对断层性能与在易震深度处断层的岩石的介质特性之间关系的认识,高力矩释放地区显示出与高地震速度相关,而破裂的初始或破裂的终止可能与低地震速度相联系。这种关系可以理解为什么断层可以被分割为各自独立破坏的段,并表明我们能够增进对预测地震以及强地面运动的能力的认识。断层显示的特性从无震蠕动到大地震引起的脆性破裂。由于沿着某个断层长度的这些变化,可以把断层分割为各自独立破坏的段落。为了研究支配着这些变化的机制,对围绕着加利福尼亚5个中强地震的区划,我们确定了该地区的三维(3D)P 波速度(V_P)模式。

Detection of early gastric cancer using hydro-stomach CT:Blinded vs unblinded analysis

AIM:To evaluate the difference in diagnostic performance of hydro-stomach computed tomography(CT) to detect early gastric cancer(EGC) between blinded and unblinded analysis and to assess independent factors affecting visibility of cancer foci.METHODS:Two radiologists initially blinded and then unblinded to gastroscopic and surgical-histological findings independently reviewed hydro-stomach CT images of 110 patients with single EGC.They graded the visibility of cancer foci for each of three gastric segments(upper,middle and lower thirds) using a 4-point scale(1:definitely absent,2:probably absent,3:probably present,and 4:definitely present).The sensitivity and specificity for detecting an EGC were calculated.Intraobserver and interobserver agreements were analyzed.The visibility of an EGC was evaluated with regard to tumor size,invasion depth,gastric segments,histological type and gross morphology using univariate and multivariate analysis.RESULTS:The respective sensitivities and specificities [reviewer 1:blinded,20%(22/110) and 98%(215/220);unblinded,27%(30/110) and 100%(219/220)/reviewer 2:blinded,19%(21/110) and 98%(216/220);unblinded,25%(27/110) and 98%(215/220)] were not significantly different.Although intraobserver agreements were good(weighted κ = 0.677 and 0.666),interobserver agreements were fair(blinded,0.371) or moderate(unblinded,0.558).For both univariate and multivariate analyses,the tumor size and invasion depth were statistically significant factors affecting visibility.CONCLUSION:The diagnostic performance of hydrostomach CT to detect an EGC was not significantly different between blinded and unblinded analysis.The tumor size and invasion depth were independent factors for visibility.

Study on Medium- and Long-term Strong Earthquake Risk Along the Zhangjiakou-Penglai Fault Zone

The Zhangjiakou-Penglai fault zone lies in the northern part of North China Plain and extends along the Zhangjiakou-Huailai-Sanhe-Tianjin-Bohai Sea-Penglai-Yantai-North Huanghai Sea line, it is about 900 km long and some 250-km wide in a northwest direction. The 1679 Sanhe-Pinggu M 8.0 and the 1976 Tangshan M7.8 earthquakes occurred in the fault zone. In this paper an analysis of Gutenberg- Richter’s empirical relation and time process of historic and recent earthquakes along the eastern and western segments of the fault zone separated by the 117°line indicates that they obey a Poison process and, hence, a calculation from it yields a cumulative probability of strong earthquake occurrence along the two segments before 2010, i. e. the probability of M6.0 earthquake occurrence is 0.80 along the eastern segment and the probability of M7. 0 earthquake occurrence is 0.76 along the western segment of the fault zone.

Potential application of neogalactosylalbumin in positron emission tomography evaluation of liver function

AIM To investigate the evaluation of neogalactosylalbumin (NGA) for liver function assessment based on positron emission tomography technology. METHODS Female Kunming mice were assigned randomly to two groups: fibrosis group and normal control group. A murine hepatic fibrosis model was generated by intraperitoneal injection of 10% carbon tetrachloride (CCl4) at 0.4 ml every 48 h for 42 d. F-18-labeled NGA ([F-18] FNGA) was synthesized and administered at a dosage of 3.7 MBq/mouse to both fibrosis mice and normal control mice. Distribution of [F-18] FNGA amongst organs was examined, and dynamic scanning was performed. Parameters were set up to compare the uptake of tracers by fibrotic liver and healthy liver. Serologic tests for liver function were also performed. RESULTS The liver function of the fibrosis model mice was significantly impaired by the use of CCl4. In the fibrosis model mice, hepatic fibrosis was verified by naked eye assessment and pathological analysis. [F-18] FNGA was found to predominantly accumulate in liver and kidneys in both control group (n = 21) and fibrosis group (n = 23). The liver uptake ability (LUA), peak time (T-p), and uptake rate (LUR) of [F-18] FNGA between healthy liver (n = 8) and fibrosis liver (n = 10) were significantly different (P < 0.05, < 0.01, and < 0.05, respectively). LUA was significantly correlated with total serum protein level (TP) (P < 0.05). T-p was significantly correlated with both TP and glucose (Glu) concentration (P < 0.05 both), and LUR was significantly correlated with both total bile acid and Glu concentration (P < 0.01 and < 0.05, respectively). CONCLUSION [F-18] FNGA mainly accumulated in liver and remained for sufficient time. Functionally-impaired liver showed a significant different uptake pattern of [F-18] FNGA compared to the controls.