厚壁型胆囊癌与慢性胆囊炎的CT鉴别诊断

目的 探讨厚壁胆囊癌与慢性胆囊炎的鉴别诊断。方法 收集经病理证实的厚壁型胆囊癌15例与慢性胆囊炎15例的CT扫描进行对比分析。结果 15例厚壁型胆囊癌壁不规则增厚，增强的胆囊壁见连续性中断6例，胆囊腔变小和失去正常形态8例，胆囊壁显僵硬9例，胆囊周界不清10例，9例病人不同程度的胆总管扩张，7例见淋巴结肿大。15例慢性胆囊炎2例壁厚薄不均，胆囊挛缩变小，壁略显僵硬2例，胆囊周界不清4例，均未见肿大淋巴结。结论 CT在胆囊癌与慢性胆囊炎的鉴别诊断中有重要价值。     

双源CT功能成像对肥厚型心肌病的诊断价值

目的：探讨双源CT（DSCT）在肥厚型心肌病（HCM）诊断中的临床应用价值。方法：回顾性分析10例确诊为HCM患者、13例正常人的临床资料和DSCT表现。结果：10例HCM患者DSCT均明确诊断,其中非对称性肥厚9例,对称性肥厚1例;l例呈梗阻性HCM。HCM组室间隔、前壁、心尖部厚度均大于对照组,侧壁、后壁厚度和对照组未见统计学差异。舒张末期左室最厚处室壁厚度与同层后壁厚度的比值（心尖部室壁厚度／基底部后壁厚度）大于1．5。LVIDd、LVID和LVOTd小于对照组,LADd大于对照组。正常人平均室壁增厚率约（57．88±5．09）％,HCM组肥厚处心肌室壁增厚率降低,约（20．10±4．89）％。HCM组左室删、EF大于对照组,EDV、ESV小于对照组。1例HCM患者冠状动脉存在粥样斑块,狭窄程度约85％;7例存在冠状动脉心肌桥,均发生在前降支。结论：DSCT实现了对HCM的解剖形态学、功能学及冠状动脉病变的“一站式”评估,在HCM诊断中具有广阔的临床应用前景。     

IgG4相关硬化性胆管炎初诊患者CT和MRI表现与血清IgG4水平升高相关性研究

目的:观察IgG4相关硬化性胆管炎（IgG4-SC）的CT和MRI表现,探究初诊患者影像特征与血清IgG4、IgG水平的关系。方法:总结50例IgG4-SC初诊患者的临床、实验室及影像资料,通过MRCP观察病变分型、管腔狭窄形态与扩张程度;增强MRI和CT观察管壁增厚、强化模式及合并其他IgG4-RD的数量,分析基线血清IgG4及IgG水平与胆管病变和合并其他IgG4-RD数量的相关性。结果:初诊41例MRCP见Ⅰ型IgG4-SC 28例,Ⅱa型11例,Ⅲ型、Ⅳ型各1例;肝外胆管狭窄端呈漏斗状37例、截断状4例,狭窄段均为长狭窄（≥1.0 cm）,其中1例胰腺段狭窄伴憩室样外凸;狭窄上游胆管扩张37例,不扩张4例。初诊42例增强MRI/CT均显示肝外胆管壁连续性增厚,15例见肝内胆管壁弥漫性增厚,管壁增厚呈向心性。50例IgG4-SC均合并AIP,其他受累器官还包括肾19例、涎腺7例、腹膜后纤维化5例、肝4例、肺4例、前列腺2例、硬化性纵隔炎2例、胆囊壁增厚20例及上腹部淋巴结肿大15例。基线血清IgG4、IgG水平升高与合并其他IgG4-RD的数量呈正相关,而与胆管壁厚度、狭窄段长度不相关。结论:胆管局限性狭窄伴上游胆管扩张或不扩张以及管壁弥漫性增厚是IgG4-SC初诊患者的特征性MRI和CT表现。基线血清IgG4及IgG水平升高与胆管病变的严重程度无关,而与合并其他IgG4-RD的数量有关。      

玉树断裂活动性研究

通过实地考察和室内工作，对玉树断裂的活动性进行了分段研究。该断裂划分为３段：（１）西北段全新世以来活动强烈，以水平左旋活动为主，水平滑动速率达７．３ｍｍ／ａ，沿断裂带展布大量的古地震事件遗迹；（２）中段第四纪以来的主体活动时段在晚更新世以前，以正断层活动为主；（３）东南段全新世以来活动强烈，以水平左旋活动为主，水平滑动速率约５ｍｍ／ａ，沿断裂带分布有大量的古地震事件遗迹，历史上记载的最大地震为１８９６年的邓柯７．０级地震     

腾冲火山地区的地震活动特征

对腾冲火山地区的地震活动时空分布及震情参数的研究结果表明，与火山活动区有关的地震活动具有以下特征：周围构造地震活动频繁而火山群地区则处于地震活动相对平静的背景，震级较低（最高为５．０～６．０级）；地震活动以小的震群活动为主，微震主要发生在腾冲县城南部的热海热田地区。长期的地震频率ｂ值高，达１．２左右；震源深度在０～２０ｋｍ范围，受周围构造大地震的影响，导致火山区地壳内部岩浆活动引起的岩浆冲击型地震发生；火山体地下低速层的存在与地下热物质有关。从腾冲火山活动区地震的时空分布特征和震情参数特征表现出与世界上其它火山地震的相似关系，表明腾冲火山不是死火山，火山体地壳内部存在的岩浆囊或岩浆移动通道内岩浆仍在活动。     

达尔布特断裂中段构造活动性

研究了达尔布转断裂中段第四纪沉积物的分布特征，阶地变形，冲洪积扇变形，断层陡坎展布及探槽揭露等方面的内容，认为达尔布特断裂中段的活动以左旋走滑为主，晚更新世晚期以来垂直活动速率在０．０１１ｍｍ／ａ，水平活动速率为０．２０～０．２２ｍｍ／ａ；且至少有２次明显活动，全新世最后１次活动可能为古地震事件，时间距今约４０００～４５００年左右，研究结果表明，达尔布特断裂中段具有发生强烈的构造条件。     

河北省怀安盆地北缘断裂活动性研究

本文以野外地质调查为主，讨论了怀安盆地北缘断裂的几何展布和活动特征，并进行了断裂的活动性分段，对断裂的运动学特片也进行了探讨，研究认为，该断裂是一条第四纪活动断裂，以东段活动性最强，Ｑ３＾２以来平均垂滑动速率达０．２１－０．２２ｍｍ／ａ；中段活动次之，西段活动较弱，整个断裂活动年代有自西南向东北迁移的趋势。最后，文章对１６２６年２５／４级地震的震中位置作了讨论。     

原发性胆囊癌的螺旋CT诊断

目的探讨胆囊癌的螺旋CT表现,以提高对本病的认识.方法回顾性分析23例经手术病理证实的胆囊癌的临床及CT表现.23例均行CT平扫及增强双期扫描.扫描延迟时间为20S-25S和60S-65S,对比剂用量100ml,注射流率3ml/s.结果胆囊癌的主要CT表现有:①胆囊壁局限性增厚或弥漫性不规则增厚7例;②胆囊区或胆囊腔内肿块16例;③合并胆囊结石6例;④直接侵犯肝脏11例.肝内转移4例.肝内外胆管扩张9例;⑤肝门及胰腺周围淋巴结转移11例.结论中晚期胆囊癌具有较典型的CT表现,80%以上的病人术前可以确诊.CT可以明确病变部位.分型及扩散范围,是一种重要的影像学检查方法,但早期发现仍存在一定困难.     

自贡地区震群活动特征的探讨

本文针对自贡地区小震群活动频繁，并经常造成一定的社会经济影响的特点，以震群为研究对象，以震群序列的类型判断为分析重点，选用ｂ值，Ｕ值、ｈ值、震群信息熵Ｋ，最大地震与次大地震震级差△Ｍ、最大地震能量占总能量的百分比Ｅ＿１／ΣＥ、蠕变曲线Σ—ｌｏｇｔ等７种常用的地震学方法作为震群类型判断的依据。以《地震学分析预报方法程式指南》有关对震群的定义为准则，从自贡地震台网１９７４年以来的地震观测资料中，选出自贡及周边地区３０个震群，利用上述方法对所有震群进行定量的分析和判断，并将判断结果与实际情况对比检验，初步评价了各方法的判别能力，找出了一些适合本地区各类型地震活动特点的判别方法和指标，为今后本区地震预报服务。计算分析结果表明：（１）自贡地区地震序列以震群型为主，约占６０％。（２）所选用的地震学方法对本区的小震群均有一定的判别效能，判别正确率在０．８５７～０．６２５之间。（３）３０个震群综合判断正确２５个，错判５个。其中震群型序列判断正确率最高，为０．９４４；主—余震型震群次之，为０．８３３；前震型震群样本较少，判断正确率也最低。（４）对于震群型和主—余震型震群的判别，Ｋ值、ｂ值效果最佳，判断正确率分别为０．９１３、     

肺小细胞神经内分泌癌MDCT征象分析

目的:探讨肺小细胞神经分泌癌的MDCT表现特征。方法:对具有完整胸部MDCT资料并经病理证实的28例肺小细胞神经内分泌癌CT表现进行回顾性分析。结果:中央型肺小细胞神经内分泌癌18例（64％）,支气管管壁增厚伴肺内肿块或结节17例（94％）,纵隔或肺门淋巴结肿大15例（83％）,增强扫描可见肿块与肿大淋巴结明显不均匀强化,周围型肺小细胞神经内分泌癌10例（36％）,密度均匀,呈分叶状,强化明显,CT无特征性表现。结论:肺小细胞神经内分泌癌主要征象以支气管管壁增厚伴肺门区肿块为主,多伴有肺门、纵膈淋巴结转移。      

SCIENCE CHINA Earth Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Distribution of throughfall and stemflow in multi‐strata agroforestry,perennial monoculture,fallow and primary forest in central Amazonia,Brazil

The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd.     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Anthropogenic Eutrophication and Red Tide Outbreak in Lacustrine Systems of the Kashmir Himalaya

Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate.