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| 1 | Source mechanism of strong aftershocks (M_s≥5.6) of the 2008/05/12 Wenchuan earthquake and the implication for seismotectonics显示文摘Dozens of >M5, hundreds of >M4, and much more >M3 aftershocks occurred after the 2008/05/12 Wenchuan earthquake, which were well recorded by permanent and portable seismic stations. After relocated with P arrival, the >M3 aftershocks show two trends of distribution, with most of the aftershocks located along the north-east strike consistent with Longmenshan fault system, yet there is a north-west trend around the epicenter. It seems that substantially more aftershocks occur in regions with crystalline bedrocks. Then we collected waveform data from National Digital Seismograph Network and regional seismograph network of China, and employed 'Cut and Paste' method to obtain focal mechanisms and depths of the big aftershocks (M≥5.6). While most of those aftershocks show thrust mechanism, there are some strike slip earthquakes in the northern-most end of the rupture. Focal mechanisms show that the events located on the southern part of central Beichuan-Yingxiu Fault (BY) are mainly thrust earthquakes, which is consistent with initial mechanism of the main shock rupture. In the north part the aftershocks along the BY are also dominated by thrust slip, which is quite different from the right slip rupture of the main shock. Around Qingchuan-Pingwu Fault, the focal mechanisms are dominated by right-slip rupture with large depths (~18 km). So we suspected that in the north part the main shock might rupture on two faults: Beichuan Fault and Qingchuan-Pingwu Fault. The complex pattern of aftershock mechanisms argues for presence of a complicated fault system in the Longmenshan area. | ZHENG Yong1,2,MA HongSheng3,Lü Jian4,NI SiDao5,LI YingChun6 & WEI ShengJi2 1 Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuhan 430077,China 2 Institute of Geophysics,Chinese Earthquake Administration,Beijing 100086,China 3 Institute of Earthquake Science,Chinese Earthquake Administration,Beijing 100086,China 4 Earthquake Administration of Jiangxi Province,Nanchang 330039,China 5 School of Earth and Space Science,University of Science and Technology of China,Hefei 230026,China 6 Earthquake Administration of Jiangsu Province,Nanjing 210014,China | 2009 | Science China Earth Sciences2009，52，6： | 100 |
| 2 | Hyperbaric oxygen preconditioning induces neuroprotection against ischemia in transient not permanent middle cerebral artery occlusion rat model显示文摘This study was designed to determine if repeated hyperbaric oxygen (HBO) exposure induces ischemic tolerance in focal cerebral ischemia Methods Sixty male SD rats were used in this study Thirty animals underwent transient middle cerebral artery occlusion (MCAO) and the other thirty permanent MCAO model The rats were randomly allocated to 3 sub-groups: control group (n=10), HBO-3 group (n=10), and HBO-5 group (n=10) The animals in HBO-3 and HBO-5 groups received 1*!hour hyperbaric oxygenation at 2 5 atmosphere absolute (ATA) in 100% oxygen every day for 3 and 5 days, respectively The animals in the control group received sham treatments 24*!hours after the last HBO, transient MCAO (120 min) and permanent MCAO were induced by introducing a 3-0 nylon monofilament suture through internal carotid artery based on the Koizumi technique The neurological outcome was evaluated until 24*!hours after reperfusion in transient MCAO rats and ischemia in permanent MCAO rats The infarct volume was then assessed by TTC staining Results In transient MCAO rats, the neurological outcome in both the HBO-3 and HBO-5 groups was better than that of the control group ( P <0 05 and 0 001) The infarct volume decreased from 171 5±113*!mm 3 to 40 6±49 9*!mm 3 ( P <0 05) in the HBO-3 group and 16 2±28 8*!mm 3 ( P <0 01) in the HBO-5 group There were no significant differences in neurological outcome and infarct volume among the three groups in permanent MCAO rats Conclusions The present study demonstrated that HBO preconditioning can induce ischemic tolerance in transient not permanent MCAO rats in a “dose-dependent' | 熊利泽 朱正华 董海龙 胡文能 候立朝 陈绍洋 | 2000 | Chinese Medical Journal2000，，9： | 60 |
| 3 | Focal depth research of earthquakes in China's Mainland: Implication for tectonics显示文摘Focal depth data of earthquakes in China's Mainland are processed and analyzed in this paper, as well as the relationship between the focal depths and large-scale tectonic structures. As a basic parameter for earthquakes, focal depth is used to investigate deep environment of seis-mogenic regions, tectonic backgrounds for concentration and release of seismic energy, the inner crustal deformation and its mechanic features. Depth data of 31282 ML≥2.0 events with 1st class and 2nd class precision in China's Mainland from Jan. 1, 1970 to May 31, 2000 are used to get spatial features of earthquakes distributed with depth and to provide average depth for each grid area throughout China. Researches show that the average depth (D) for all the earthquakes used in this paper is (16±7) km, and (13±6) km and (18±8) km for the events in eastern China and western China, respectively. The area with the deepest focal depth is located in southwest Xinjiang region, near the western and southwestern ends of the Tarim | ZHANG Guomin WANG Suyun LI Li ZHANG Xiaodong MA Hongsheng | 2002 | Chinese Science Bulletin2002，47，12： | 38 |
| 4 | Gd-EOB-DTPA-enhanced magnetic resonance imaging for focal liver lesions in Chinese patients:a multicenter,open-label,phase Ⅲ study显示文摘BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions and healthy tissue.This study was undertaken to evaluate the efficacy and safety of the liverspecific MR imaging contrast agent gadoxetate disodium(GdEOB-DTPA)in Chinese patients.METHODS:This was a single-arm,open-label,multicenter study in patients with known or suspected focal liver lesions referred for contrast-enhanced MR imaging.MR imaging was performed in 234 patients before and after a single intravenous bolus of Gd-EOB-DTPA(0.025 mmol/kg body weight).Images were evaluated by clinical study investigators and three independent,blinded radiologists.The primary efficacy endpoint was sensitivity in lesion detection.RESULTS:Gd-EOB-DTPA improved sensitivity in lesion detection by 9.46%compared with pre-contrast imaging for the average of the three blinded readers(94.78%vs 85.32%for Gd-EOB-DTPA vs pre-contrast,respectively).Improvements in detection were more pronounced in lesions less than 1cm.Gd-EOB-DTPA improved diagnostic accuracy in lesion classification.CONCLUSIONS:This open-label study demonstrated that Gd-EOB-DTPA improves diagnostic sensitivity in liver lesions,particularly in those smaller than 1 cm.Gd-EOB-DTPA also significantly improves the diagnostic accuracy in lesion classification,and furthermore,Gd-EOB-DTPA is safe in Chinese patients with liver lesions. | Meng-Su Zeng Hui-Yi Ye Liang Guo Wei-Jun Peng Jian-Ping Lu Gao-Jun Teng Josy Breuer Yi Huan Ping Li Jian-Rong Xu Chang-Hong Liang | 2013 | Hepatobiliary & Pancreatic Diseases International2013，12，6： | 31 |
| 5 | Focal autoimmune pancreatitis: Radiological characteristics help to distinguish from pancreatic cancer显示文摘AIM: To identify the radiological characteristics of focal autoimmune pancreatitis (f-AIP) useful for differentiation from pancreatic cancer (PC). METHODS: Magnetic resonance imaging (MRI) and triple-phase computed tomography (CT) scans of 79 patients (19 with f-AIP, 30 with PC, and 30 with a normal pancreas) were evaluated retrospectively. A radiologist measured the CT attenuation of the pancreatic parenchyma, the f-AIP and PC lesions in triple phases. The mean CT attenuation values of the f-AIP lesions were compared with those of PC, and the mean CT attenuation values of pancreatic parenchyma in the three groups were compared. The diagnostic performance of CT attenuation changes from arterial phase to hepatic phase in the differentiation between f-AIP and PC was evaluated using receiver operating characteristic (ROC) curve analysis. We also investigated the incidence of previously reported radiological findings for differentiation between f-AIP and PC. RESULTS: The mean CT attenuation values of f-AIP lesions in enhanced phases were significantly higher than those of PC (arterial phase: 60 ± 7 vs 48 ± 10, P < 0.05; pancreatic phase: 85 ± 6 vs 63 ± 15, P < 0.05; hepatic phase: 95 ± 7 vs 63 ± 13, P < 0.05). The mean CT attenuation values of f-AIP lesions were significantly lower those of uninvolved pancreas and normal pancreas in the arterial and pancreatic phase of CT (P < 0.001, P < 0.001), with no significant difference at the hepatic phase or unenhanced scanning (P = 0.4, P = 0.1). When the attenuation value increase was equal or more than 28 HU this was considered diagnostic for f-AIP, and a sensitivity of 87.5%, specificity of 100% and an area under the ROC curve of 0.974 (95%CI: 0.928-1.021) were achieved. Five findings were more frequently observed in f-AIP patients: (1) sausageshaped enlargement; (2) delayed homogeneous enhancement; (3) hypoattenuating capsule-like rim; (4) irregular narrowing of the main pancreatic duct (MPD) and/or stricture of the common bile duct (CBD); and (5) MPD upstream dilation ≤ 5 mm. CONCLUSION: Analysis of a combination of CT and MRI findings could improve the diagnostic accuracy of differentiating f-AIP from PC. | Gao-Feng Sun Chang-Jing Zuo Cheng-Wei Shao Jian-Hua Wang Jian Zhang | 2013 | World Journal of Gastroenterology2013，19，23： | 34 |
| 6 | A shallow aftershock sequence in the north-eastern end of the Wenchuan earthquake aftershock zone显示文摘Previous studies show that mature faults are filled with fault gouge in the shallow part and thus cannot accumulate enough strain energy for earthquakes. Therefore most earthquakes are deeper than 5 km, except those events occurring on new faults or in intact rocks. From field observation, Wenchuan earthquake is found to rupture the free surface about 200 km, but the rupture may extend underground much further from teleseismic body waves inversion and aftershocks distribution. In the northeastern end of the rupture zone, deep rupture may induce stress increase near the free surface, and trigger shallow earthquakes. An Ms 5.7 aftershock occurred at Qingchuan, northeast end of Wenchuan earthquake fault on July 24, 2008, featuring thrust mechanism with a 3 km source centroid depth. The shallow focal depth is confirmed with the sPL phase recorded at station L0205. As Rayleigh wave is well only developed for source depth less than 1/5 of epicentral distance, the observed large amplitude of Rg at a distance of 15 km implied depth of 3 km or less. Dozens of aftershocks' sPL waveforms are also analyzed to confirm the source depths less than 3 km. On the other hand, no surface ruptures are found by geological survey or InSAR studies. It is strongly suggested that these aftershock sequences initiate fresh rupture in intact rocks triggered by stress increase from the deep co-seismic rupture of the Wenchuan mainshock. | Luo Yan Ni SiDao Zeng XiangFang Zheng Yong Chen QiFu Chen Yong | 2010 | Science China Earth Sciences2010，53，11： | 26 |
| 7 | Characterization of focal liver masses using acoustic radiation force impulse elastography显示文摘AIM:To investigate the diagnostic performance of acoustic radiation force impulse(ARFI) elastography for characterizing focal liver mass by quantifying their stiffness.METHODS:This prospective study included 62 patients with a focal liver mass that was well visualized on conventional ultrasonography performed in our institution from February 2011 to November 2011.Among them,12 patients were excluded for ARFI measurement failure due to a lesion that was smaller than the region of the interest and at an inaccessible location(deeper than 8 cm)(n = 7) or poor compliance to hold their breath as required(n = 5).Finally,50 patients with valid ARFI measurements were enrolled.If a patient had multiple liver masses,only one mass of interest was chosen.The masses were diagnosed by histological examination or clinical diagnostic criteria.During ultrasonographic evaluation,stiffness,expressed as velocity,was checked 10 times per focal liver mass and the surrounding liver parenchyma.RESULTS:After further excluding three masses that were non-diagnostic on biopsy,a total of 47 focal mass lesions were tested,including 39(83.0%) malignant masses [24 hepatocellular carcinomas(HCC),seven cholangiocellular carcinomas(CCC),and eight liver metastases] and eight(17.0%) benign masses(five hemangiomas and three focal nodular hyperplasias,FNH).Thirty-seven(74.0%) masses were confirmed by histological examination.The mean velocity was 2.48 m/s in HCCs,1.65 m/s in CCCs,2.35 m/s in metastases,1.83 m/s in hemangiomas,and 0.97 m/s in FNHs.Although considerable overlap was still noted between malignant and benign masses,significant differences in ARFI values were observed between malignant and benign masses(mean 2.31 m/s vs 1.51 m/s,P = 0.047),as well as between HCCs and benign masses(mean 2.48 m/s vs 1.51 m/s,P = 0.006).The areas under the receiver operating characteristics curves(AUROC) for discriminating the malignant masses from benign masses was 0.724(95%CI,0.566-0.883,P = 0.048),and the AUROC for discriminating HCCs from benign masses was 0.813(95%CI,0.649-0.976,P = 0.008).To maximize the sum of sensitivity and specificity,an ARFI value of 1.82 m/s was selected as the cutoff value to differentiate malignant from benign liver masses.Furthermore,the cutoff value for distinguishing HCCs from benign masses was also determined to be 1.82 m/s.The diagnostic performance of the sum of the ARFI values for focal liver masses and the surrounding liver parenchyma to differentiate liver masses improved(AUROC = 0.853;95%CI,0.745-0.960;P = 0.002 in malignant liver masses vs benign ones and AUROC = 0.948;95%CI,0.896-0.992,P < 0.001 in HCCs vs benign masses).CONCLUSION:ARFI elastography provides additional information for the differential diagnosis of liver masses.However,our results should be interpreted in clinical context,because considerable overlap in ARFI values existed among liver masses. | Hana Park Jun Yong Park Do Young Kim Sang Hoon Ahn Chae Yoon Chon Kwang-Hyub Han Seung Up Kim | 2013 | World Journal of Gastroenterology2013，19，2： | 22 |
| 8 | 改进的XGBoost在不平衡数据处理中的应用研究显示文摘传统分类器在处理不平衡数据时,往往会倾向于保证多数类的准确率而牺牲少数类的准确率,导致少数类的误分率较高。针对这一问题,提出一种面向二分类不平衡数据的XGBoost(eXtreme Gradient Boosting)改进方法。其主要思想是分别从数据、特征以及算法3个层面针对不平衡数据的特点进行改进。首先在数据层面,通过条件生成式对抗网络(Conditional Generative Adversarial Nets,CGAN)学习少数类样本的分布信息,训练生成器生成少数类补充样本,调节数据的不平衡性;其次在特征层面,先利用XGBoost进行特征组合生成新的特征,再通过最大相关最小冗余(minimal Redundancy-Maximal Relevance,mRMR)算法筛选出更适合不平衡数据分类的特征子集;最后在算法层面,引入针对不平衡数据分类问题的焦点损失函数(Focal Loss)来改进XGBoost,改进后的XGBoost通过新的数据集训练得到最终模型。在实验阶段,选择G-mean和AUC作为评价指标,6组KEEL数据集上的实验结果验证了所提改进方法的可行性;同时将该方法与现有的4种不平衡分类模型进行比较,实验结果表明所提改进方法具有较好的分类效果。 | 宋玲玲 王时绘 杨超 盛潇 | 2020 | 计算机科学2020，47，6： | 18 |
| 9 | 肝脏局灶性结节增生的MSCT诊断显示文摘目的分析肝脏局灶性结节增生(FNH)的CT特征,以提高本病CT诊断水平。方法回顾性分析23例经病理证实的肝脏局灶性结节增生(FNH)的临床资料和CT表现。23例全部行CT平扫及三期增强扫描。结果 23例FNH均为单发肿块,位于肝脏包膜下16例,突出肝脏表面呈外生性生长7例。大小11mm×13mm^45mm×50mm;圆形或卵圆形21例,不规则形2例。23例FNH平扫均呈低密度影,15例密度均匀;8例密度不均匀。增强扫描:23例FNH动脉期明显强化,2例动脉期CT值接近同层面腹主动脉CT值,门静脉期和延迟期呈相对高和等密度22例,呈'快进慢出'的强化特点。14例肿块中央见裂隙状疤痕,疤痕呈缓慢渐进性强化。9例FNH肝门侧见增粗迂曲血管影,2例肿块中央见增粗迂曲血管影。结论 FNH的CT表现较具特征性,CT表现对本病的诊断和鉴别诊断具有重要价值。 | 李增荣 陈本宝 | 2014 | 医学影像学杂志2014，24，6： | 17 |
| 10 | Geometry and tectonic deformation of the seismogenic structure for the 8 August 2017 M_S 7.0 Jiuzhaigou earthquake sequence,northern Sichuan, China显示文摘To reveal the geometry of the seismogenic structure of the Aug. 8, 2017 M_S 7.0 Jiuzhaigou earthquake in northern Sichuan,data from the regional seismic network from the time of the main event to Oct. 31, 2017 were used to relocate the earthquake sequence by the tomoDD program, and the focal mechanism solutions and centroid depths of the M_L ≥ 3.5 events in the sequence were determined using the CAP waveform inversion method. Further, the segmental tectonic deformation characteristics of the seismogenic faults were analyzed preliminarily by using strain rosettes and areal strains(As). The results indicate:(1) The relocated M_S 7.0 Jiuzhaigou earthquake sequence displays a narrow ~ 38 km long NNW-SSE-trending zone between the NW-striking Tazang Fault and the nearly NSstriking Minjiang Fault, two branches of the East Kunlun Fault Zone. The spatial distribution of the sequence is narrow and deep for the southern segment, and relatively wide and shallow for the northern segment. The initial rupture depth of the mainshock is 12.5 km, the dominant depth range of the aftershock sequence is between 0 and 10 km with an average depth of 6.7 km. The mainshock epicenter is located in the middle of the aftershock region, showing a bilateral rupture behavior. The centroid depths of 32 M_L ≥ 3.5 events range from 3 to 12 km with a mean of about 7.3 km, consistent with the predominant focal depth of the whole sequence.(2) The geometric structure of the seismogenic fault on the southern section of the aftershock area(south of the mainshock) is relatively simple, with overall strike of ~150° and dip angle ~75°, but the dip angle and dip-orientation exhibit some variation along the segment. The seismogenic structure on the northern segment is more complicated; several faults, including the Minjiang Fault, may be responsible for the aftershock activities. The overall strike of this section is ~159° and dip angle is ~59°, illustrating a certain clockwise rotation and a smaller dip angle than the southern segment. The differences between the two segments demonstrate variation of the geometric structure along the seismogenic faults.(3) The focal mechanism solutions of 32 M_L ≥ 3.5 events in the earthquake sequence have obvious segmental characteristics. Strike-slip earthquakes are dominant on the southern segment, while 50% of events on the northern segment are thrusting and oblique thrusting earthquakes, revealing significant differences in the kinematic features of the seismogenic faults between the two segments.(4) The strain rosettes for the mainshock and the entire sequence of 31 M_L ≥ 3.5 aftershocks correspond to strike-slip type with NWW-SEE compressional white lobes and NNE-SSW extensional black lobes of nearly similar size. The strain rosette and As value of the entire sequence of 22 M_L ≥ 3.5 events on the southern segment are the same as those of the M_S 7.0 mainshock,indicating that the tectonic deformation here is strike-slip. However, the strain rosette of the entire sequence of 10 M_L ≥ 3.5 events on the northern segment show prominent white compressional lobes and small black extensional lobes, and the related As value is up to 0.52,indicating that the tectonic deformation of this segment is oblique thrusting with a certain strike-slip component. Differences between the two segments all reveal distinctly obvious segmental characteristics of the tectonic deformation of the seismogenic faults for the Jiuzhaigou earthquake sequence. | Feng Long GuiXi Yi SiWei Wang YuPing Qi Min Zhao | 2019 | Earth and Planetary Physics2019，3，3： | 17 |
| 11 | Benign liver tumors in pediatric patients-Review with emphasis on imaging features显示文摘Benign hepatic tumors are commonly observed in adults,but rarely reported in children.The reasons for this remain speculative and the exact data concerning the incidence of these lesions are lacking.Benign hepatic tumors represent a diverse group of epithelial and mesenchymal tumors.In pediatric patients,most benign focal liver lesions are inborn and may grow like the rest of the body.Knowledge of pediatric liver diseases and their imaging appearances is essential in order to make an appropriate differential diagnosis.Selection of the appropriate imaging test is challenging,since it depends on a number of age-related factors.This paper will discuss the most frequently encountered benign liver tumors in children(infantile hepatic hemangioendothelioma,mesenchymal hamartoma,focal nodular hyperplasia,nodular regenerative hyperplasia,and hepatocellular adenoma),as well as a comparison to the current knowledge regarding such tumors in adult patients.The current emphasis is on imaging features,which are helpful not only for the initial diagnosis,but also for pre- and posttreatment evaluation and follow-up.In addition,future perspectives of contrast-enhanced ultrasound(CEUS) in pediatric patients are highlighted,with descriptions of enhancement patterns for each lesion being discussed.The role of advanced imaging tests such as CEUS and magnetic resonance imaging,which allow for non-invasive assessment of liver tumors,is of utmost importance in pediatric patients,especially when repeated imaging tests are needed and radiation exposure should be avoided. | Liliana Chiorean Xin-Wu Cui Andrea Tannapfel Doris Franke Martin Stenzel Wojciech Kosiak Dagmar Schreiber-Dietrich J?rg Jüngert Jian-Min Chang Christoph F Dietrich | 2015 | World Journal of Gastroenterology2015，21，28： | 16 |
| 12 | Regional stress field in Yunnan revealed by the focal mechanisms of moderate and small earthquakes显示文摘We determined focal mechanism solutions of 627 earthquakes of magnitude M ≥ 3.0 in Yunnan from January 2008 to May 2018 by using broadband waveforms recorded by 287 permanent and temporary regional stations. The results clearly revealed predominantly strike-slip faulting characteristics for earthquakes in Yunnan, with focal depths concentrated in the top 10 km of the crust. The earthquake mechanisms obtained were combined with the global centroid moment tensor solutions of 80 additional earthquakes from 1976 to 2016 to invert for the regional variations of stress field orientation by using a damped regional-scale stress inversion scheme.Results of the stress field inversion confirmed that the Yunnan region is under a strike–slip stress regime, with both maximum and minimum stress axes being nearly horizontal. The maximum compressional axes are primarily oriented in a northwest-southeast direction, and they experience a clockwise rotation from north to south, whereas the maximum extensional axes are oriented largely northeast-southwest. The maximum compressional axes are in line with the global positioning system–inferred horizontal velocity field and the southeastward escape of the Sichuan–Yunnan Rhombic Block, whereas the maximum extensional axes are consistent with anisotropy derived from SKS splitting. Against the strike–slip background, normal faulting stress regimes can be seen in the Tengchong volcanic area as well as in other areas with complex crisscrossing fault zones. | JianHui Tian Yan Luo Li Zhao | 2019 | Earth and Planetary Physics2019，3，3： | 16 |
| 13 | Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions显示文摘The extensive use of imaging techniques in differential diagnosis of abdominal conditions and screening of hepatocellular carcinoma in patients with chronic hepatic diseases,has led to an important increase in identification of focal liver lesions.The development of contrastenhanced ultrasound(CEUS) opens a new window in the diagnosis and follow-up of these lesions.This technique offers obvious advantages over the computed tomography and magnetic resonance,without a decrease in its sensitivity and specificity.The new second generation contrast agents,due to their intravascular distribution,allow a continuous evaluation of the enhancement pattern,which is crucial in characterization of liver lesions.The dual blood supply in the liver shows three different phases,namely arterial,portal and late phases.The enhancement during portal and late phases can give important information about the lesion's behavior.Each liver lesion has a different enhancement pattern that makes possible an accurate approach to their diagnosis.The role of emerging techniques as a contrastenhanced three-dimensional US is also discussed.In this article,the advantages,indications and technique employed during CEUS and the different enhancement patterns of most benign and malignant focal liver lesions are discussed. | Inés Gómez Molins Juan Manuel Fernández Font Juan Carrero álvaro Jose Luís Lledó Navarro Marta Fernández Gil Conrado M Fernández Rodríguez | 2010 | World Journal of Radiology2010，2，12： | 14 |
| 14 | Velocity structure of uppermost mantle beneath North China from Pn tomography and its implications显示文摘20301 Pn arrival time data are collected from the seismological bulletins of both national and regional seismic networks. Pn travel time residuals are tomographically inverted for the Pn velocity structure of uppermost mantle beneath North China. The result indicates that the average Pn velocity in North China is 7.92 km/s, and the velocity varies laterally from ?0.21 to +0.29 km/s around the average. The approximately NNE trending high and low velocity regions arrange alternatively west-eastward. From west to east we can see high velocity in the middle Ordos region, the Shanxi graben low, the Jizhong depression high, the west Shandong uplift and Bohai Sea low, and the high velocity region to the east of the Tanlu fault. In the southern boundary zone of the North China block, except for the high velocity in the Qingling Mountains region, the velocity is generally lower than the average. Obvious velocity anisotropy is seen in the Datong Cenozoic volcanic region, with the fast velocity direction in NNE-SSW. Notable velocity anisotropy is also seen around the Bay of Bohai Sea, and the fast velocity directions seem to show a rotation pattern, possibly indicating a flow-like deformation in the uppermost mantle there. The Pn velocity variations show a reversed correlation with the Earth's heat flow. The low Pn velocity regions generally show high heat flow, e.g., the Shanxi graben and Bohai Sea region. While the high Pn velocity regions usually manifest low heat flow, e.g., the region of Jizhong depression. This indicates that the Pn velocity variation in the study region is mainly aroused by the regional temperature difference in the uppermost mantle. Strong earthquakes in the crust tend to occur in the region with the abnormal low Pn velocity, or in the transition zone between high and low Pn velocity regions. The earthquakes in the low velocity region are shallower, while that in the transition zone are deeper. | WANG Suyun (汪素云) XU Zhonghuai (许忠淮) PEI Shunping (裴顺平) | 2003 | Science China Earth Sciences2003，46，z2： | 13 |
| 15 | Focal nodular hyperplasia of the liver in 86 patients显示文摘BACKGROUND: Focal nodular hyperplasia (FNH), the second most common benign hepatic tumor after hemangioma, is characterized by a stellate central scar and hyperplastic nodules. Although some large FNH may be associated with significant symptoms, more frequently they are discovered incidentally on physical examination or the work-up of unrelated symptoms. Since its nature and pathogenesis are still controversial, accurate diagnosis of FNH based on clinical presentation and radiographic studies is difficult. The purpose of this study was to explore the diagnosis and treatment of FNH. METHODS: Eighty-six FNH patients confirmed patholo- gically were treated at the Liver Cancer Institute in our hospital from 1996 to 2006. Their clinical manifestions, imaging presentation, pathological findings, and surgical results were analyzed retrospectively. RESULTS: Of the 86 patients with 99 foci, 54 were male and 32 female, with a mean age of 37 years. Eighty patients had a single solitary focus and 6 had multiple foci. Tumor diameter was less than 5 cm in 69 patients, 5-10 cm in 15, and more than 10 cm in 2. The overall rate of correct preoperative diagnosis was 59.3% (51/86) including 32.9% (26/79) by color Doppler flow imaging (CDFI), 60.3% (35/58) by CT, and 77.4% (24/31) by MRI. All the 86 patients underwent resection with good curative effect.CONCLUSIONS: CT and MRI are important diagnostic methods for FNH but it is difficult to make a definite preoperative diagnosis for partial classical and all non- classical FNH patients. We suggest that patients with clinical symptoms or with indefinite diagnosis should accept surgical removal. | Shen, Ying-Hao Fan, Jia Wu, Zhi-Quan Ma, Zeng-Chen Zhou, Xin-Da Zhou, Jian Qiu, Shuang-Jian Qin, Lun-Xiu Ye, Qin-Hai Sun, Hui-Chuan Huang, Xiao-Wu Tang, Zhao-You | 2007 | Hepatobiliary & Pancreatic Diseases International2007，6，1： | 13 |
| 16 | Differential diagnosis and management of liver tumors in infants显示文摘During the first year of life, most of the liver neoplasms are benign in origin, but some of these histologically benign lesions may be challenging in their management. Although most hepatic hemangiomas can be safely observed until involution is documented, some patients will need treatment due to progressive hepatomegaly, hypothyroidism and/or cardiac failure. Large mesenchymal hamartomas may require extensive hepatic resection and an appropriate surgical plan is critical to obtain good results. For malignant neoplasms such as hepatoblastoma, complete surgical resection is the mainstay of curative therapy. The decision about whether to perform an upfront or delayed resection of a primary liver malignant tumor is based on many considerations, including the ease of resection, surgical expertise, tumor histology and stage, and the likely chemosensitivity of the tumor. This article reviews the initial management of the more common hepatic tumors of infancy, focusing on the differential diagnosis and treatment options. | Israel Fernez-Pineda Rosa Cabello-Laureano | 2014 | World Journal of Hepatology2014，6，7： | 12 |
| 17 | Hepatocellular adenoma: An update显示文摘Hepatocellular adenomas(HCA) are rare benign liver tumors.Recent technological advancements have helped in the early identification of such lesions.However,precise diagnosis of hepatocellular incidentalomas remains challenging.Studies at the molecular level have provided new insights into the genetics and pathophysiology of these lesions.These in turn have raised questions over their existing management modalities.However,the rarity of the tumor still restricts the quality of evidence available for current recommendations and guidelines.This article provides a comprehensive review on the etiology,molecular biology,pathophysiology,clinical manifestations,and complications associated with HCA.It also elaborates on the genetic advancements,existing diagnostic tools and current guidelines for management for such lesions. | Adarsh Vijay Ahmed Elaffandi Hatem Khalaf | 2015 | World Journal of Hepatology2015，7，25： | 12 |
| 18 | Application of acoustic radiation force impulse imaging for the evaluation of focal liver lesion elasticity显示文摘BACKGROUND: Acoustic radiation force impulse (ARFI) imaging is a new elastography method for the evaluation of tissue stiffness. This study aims to evaluate the performance of ARFI in noninvasive assessment of the tissue stiffness of focal liver lesion (FLL) and to explore its potential value in the differential diagnosis of FLL. METHODS: ARFI was performed in 140 patients with 154 FLLs, which included 28 hemangiomas (ANGIs), 14 focal nodular hyperplasias (FNHs), 61 hepatocellular carcinomas (HCCs), 39 metastases and 12 cholangiocellular carcinomas (CCCs). Virtual touch tissue quantification (VTTQ) values were obtained, analyzed and compared. The area under the receiver operating characteristic curve (AUROC) and optimal cut-off values were obtained using a receiver operating characteristic (ROC) curve analysis to assess diagnostic performance. All cases were definitively diagnosed using histopathology, CT, MRI or contrast-enhanced ultrasound. RESULTS: The VTTQ median values of ANGI, FNH, HCC metastasis and CCC were 1.30, 1.80, 2.52, 3.08 and 3.89 m/s respectively. A significant increase in the VTTQ values of different lesions was observed: ANGI | Ping Zhang Ping Zhou Shuang-Ming Tian Ying Qian Jin Deng Lu Zhang | 2013 | Hepatobiliary & Pancreatic Diseases International2013，12，2： | 11 |
| 19 | Gravity pattern in southeast margin of Tibetan Plateau and its implications to tectonics and large earthquakes显示文摘There are many active faults in the southeast margin of Tibetan Plateau,where three large active faults zones,the Longmenshan,Xianshuihe and Anninghe,merge to form a'Y'shape.Strong crustal deformation and a complicated fault distribution accompany strong earthquake activity in this zone.In this paper,we investigate a multi-scale gravity anomaly in the southeastern margin of the Tibetan Plateau using the wavelet transform;we find that the pattern of the gravity field is closely related to the fault system in the study area.Analyzing the characteristics of this Bouguer gravity anomaly at different orders indicates that the eastern Himalayan syntaxis has produced a strong eastward push during its northward movement,resulting in a shortening of the crust from west to east and a rapid uplift of the Tibetan Plateau.The Songpan–Garzêand Sichuan–Yunnan blocks have been forced to slip and extrude southward and eastward laterally.The distributions of seven large earthquakes from 1970 to 2018 reflects the relationship between large earthquakes and characteristics of the gravity anomaly.Comparing the tectonic backgrounds of several earthquakes reveals that the large earthquakes occur usually in the high gravity anomaly gradient zone,which corresponds in general to the boundary zones of the blocks.We infer that large earthquakes occur primarily in high Bouguer gravity anomaly zones in the upper crust,while low Bouguer gravity anomalies encompass the lower crust and the uppermost mantle. | Yue Wu Yuan Gao | 2019 | Earth and Planetary Physics2019，3，5： | 10 |
| 20 | Clinical value of contrast-enhanced ultrasonography in the characterization of focal liver lesions:a prospective multicenter trial显示文摘BACKGROUND:Contrast-enhanced ultrasonography(CEUS) is increasingly accepted in clinical settings for diagnostic imaging of focal liver lesions(FLLs).This study aimed to assess the efficacy of CEUS in the characterization of FLLs in comparison with final diagnosis based on gold standard assessment. METHODS:The study was approved by the local ethics committee and participating patients provided written informed consent.A total of 148 patients with 164 FLLs were studied.Unenhanced ultrasonography(US)and CEUS were performed using fundamental and harmonic imaging,respectively.Contrast enhancement was assessed during the arterial,portal and late vascular phases after intravenous administration of contrast(SonoVue?,Bracco, Italy).Sensitivity,specificity and diagnostic accuracy of USand CEUS were compared in identifying the lesion as benign, malignant or indeterminate and its actual tumor type.Final diagnosis was established by biopsy(129/164),MR imaging (11/164)or medical history(24/164). RESULTS:When compared to the gold standard,the number of indeterminate diagnoses was reduced from 56.7%(93/164)as assessed by fundamental imaging to 6.1%(10/164)after SonoVue?enhanced US examination. Sensitivity and specificity improved from 49%and 25% at baseline US to 93%and 75%with CEUS,respectively (P<0.01).Diagnostic accuracy of CEUS was 88%in contrast to 41%of baseline US. CONCLUSION:SonoVueenhanced US improves the characterization of FLLs and may limit the need for further investigations. | Wang, Wen-Ping Wu, Ying Luo, Yan Li, Rui Zhou, Xiao-Dong Zhang, Jun Qian, Chao-Wen Tan, Xu-Yan Xu, Qing-Hua Wang, Yan Yuan, Jian-Jun | 2009 | Hepatobiliary & Pancreatic Diseases International2009，8，4： | 10 |
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