快速充盈型肝海绵状血管瘤的CT表现及特点

目的探讨快速充盈型肝海绵状血管瘤（ffHCH）的动态增强CT表现特征。方法回顾性分析13例共15个ffHCH病灶的强CT资料,观察病灶部位、大小、三期动态（动脉期、门静脉期及延迟期）强化模式,以及是否伴有动脉-门静脉分流（APS）、假包膜征及肝包膜回缩征等表现。结果ffHCH病灶好发于肝右叶近包膜下区域;直径（2.42±0.64）cm;动脉期病灶完全强化呈高密度,病灶平均CT值明显高于同期正常肝实质（P〈0.05）;门静脉期病灶呈高或等密度,病灶平均CT值仍明显高于肝实质（P〈0.05）;延迟期病灶呈等或稍高密度,但其强化程度与肝实质无统计学意义（P〉0.05）;部分病灶可见APS,发生率33.33%;无假包膜征及肝包膜回缩征。结论ffHCH三期增强CT表现在病灶位置、大小、增强方式和伴发APS等方面有一定特征,有助于该病的诊断。     

自体静脉或双层自体静脉（双套式）液压扩张移植修复中型动脉缺损（附23例报告）

用自体静脉液压扩张移植修复中型动脉缺损２３例（条）结果均获成功，效果良好。液压扩张后扩大了静脉移植范围，移植血管远端的器官组织远期没有缺血现象。应用双套式吻接法修复肿瘤切除所致的血管缺损，解决了以往因肿瘤侵犯较大血管而放弃手术的难题。     

Dissociation of bradycardia and arterial constriction during diving in the seal Phoca vitulina

Bradycardia associated with diving in the harbor seal has been dissociated from the arterial constrictor response by intracardiac pacing. Development of arterial constriction does not depend upon the development of bradycardia. During pacing, arterial constriction continues in the absence of bradycardia. Increases in heart rate to values greater than 120 beats per minute during a dive produce a progressive decrease in mean aortic pressure, which suggests that one major function of bradycardia is to reduce cardiac output, thus matching left ventricular output to the restricted vascular bed and decreased venous return associated with diving.     

超声造影诊断肝脏良、恶性病变的临床意义

目的了解超声造影诊断肝脏良、恶性病变的增强表现及临床意义。方法对经手术、病理、或增强CT(MRI)证实的58例患者60个肝局灶性病变进行超声造影,研究病灶的造影增强模式,并判断病变的良性、恶性。结果(1)恶性病灶:原发性肝细胞癌(HCC)9个呈"快进快出";转移性肝癌14个,动脉期多呈周边环状或厚圈状"快进",之后均廓褪为低或极低回声。(2)良性病灶:19个肝血管瘤多为典型"慢进慢出";9个局灶性增生结节多为快进慢出型,早期可见增强的中央血管及放射状血管,其余9个肝脏良性病灶多表现为"慢出"型。结论肝内良、恶性病灶具有不同的增强模式和特征,超声造影对肝内良恶性病变的鉴别诊断具有很好的应用意义。     

成年皖西白鹅母鹅消化腺的形态学观察

研究了成年皖西白鹅母鹅消化腺的形态特征。结果表明 :成年皖西白鹅母鹅消化腺由唾液腺、肝脏和胰腺组成。肝脏的组织结构由肝小叶和门管区构成 ,肝小叶由中央静脉、肝细胞管和肝窦组成 ,门管区包括小叶间胆管、小叶间动脉和小叶间静脉 ,还有淋巴组织分布。胰腺包括外分泌部和内分泌部 ,外分泌部由腺泡和导管组成 ,内分泌部为一细胞团 ,即胰岛。     

Trading water for carbon with biological carbon sequestration

Carbon sequestration strategies highlight tree plantations without considering their full environmental consequences. We combined field research, synthesis of more than 600 observations, and climate and economic modeling to document substantial losses in stream flow, and increased soil salinization and acidification, with afforestation. Plantations decreased stream flow by 227 millimeters per year globally (52%), with 13% of streams drying completely for at least 1 year. Regional modeling of U.S. plantation scenarios suggests that climate feedbacks are unlikely to offset such water losses and could exacerbate them. Plantations can help control groundwater recharge and upwelling but reduce stream flow and salinize and acidify some soils.     

Reductions in arterial diameter produced by chronic decreases in blood flow are endothelium-dependent

A 70 percent reduction in the rate of blood flow through the common carotid artery in rabbits caused a 21 percent decrease in the diameter of this artery within 2 weeks. The smooth muscle relaxant papaverine did not attenuate the response; therefore, such reductions in diameter probably reflect a structural modification of the arterial wall rather than sustained contraction of smooth muscle. This arterial response to reduced blood flow was abolished when the endothelium was removed from the vessels. It appears that the endothelium is essential for the compensatory arterial response to long-term changes in luminal blood flow rates.     

棋斑游蛇循环系统的解剖

本文报道了棋斑游蛇循环系统的解剖结果,重点观察了心脏的结构,以探讨血液在心脏中的运行机制。     

Brain tryptophan hydroxylation: dependence on arterial oxygen tension

The accumulation of cerebral 5-hydroxytryptophan after decarboxylase inhibition was decreased in rats maintained at arterial O(2) tensions below 60 mm-Hg. In contrast, brain lactate was stable above 40 mm-Hg and brain adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate were unchanged above 30 mm-Hg. There was a linear correlation of brain 5-hydroxytryptophan accumulation to cerebral venous O(2) tension. Cerebral tryptophan hydroxylase appears to have a poor affinity for oxygen and to be affected by slight hypoxia. The resultant decreases in monoamine neurotransmitter metabolism may explain the behavioral changes of mild oxygen deprivation.     

Groundwater: Flow Toward an Effluent Stream

Hydrodynamic, topographic, and geologic factors control flow of groundwater toward an effluent stream. Features of such flow are illustrated by a hydraulic model that simulates the stream and surrounding consolidated rocks. Colored ink in the flow system marks progress toward the stream. Visual analysis shows that groundwater moves into the effluent stream along curvilineal flow lines. The total head of groundwater beneath the stream increases with depth.     

脾虚证大鼠肝脏组织的病理变化

观察脾虚证模型大鼠肝脏组织病理学变化,探讨脾虚证中肝脏组织病理学变化与脾虚证时肝脏功能障碍间的联系。利血平复制大鼠脾虚证模型,运用组织病理学研究方法,从不同方面观察研究肝脏组织病理学变化。在研究中发现,脾虚证模型大鼠肝脏组织中出现淤血,细胞变性,萎缩,炎性细胞浸润等病理变化,而且肝脏组织中糖原储存量显著减少,门管区胶原纤维增生,细胞中酸性磷酸酶活性升高,透射电镜观察发现细胞质中蓄积大量的次级溶酶体,细胞核出现皱缩,细胞体积减小,线粒体肿胀。脾虚证中肝脏组织发生多种组织病理学变化,很有可能是引起脾虚证肝功能障碍的原因。     

虹鳟胆管系统组织学观察

采用常规苏木精.伊红(hematoxylin-eosin)H.E染色法、Masson三色染色法、Gomori银染法结合透射电镜研究技术,对虹鳟肝脏胆管形态结构进行了观察.结果表明:虹鳟肝脏被覆单层扁平上皮组织,肝实质内结缔组织较少,肝小叶结构不明显;汇管区结缔组织内含丰富的胶原纤维、网状纤维和弹性纤维;汇管区存在胆管孤管型、胆管动脉型、胆管静脉型和胆管动静脉型4种构型;肝细胞由双层肝板呈管式排列,双层肝板之间可见胆管上皮细胞;胆管、胆小管、前胆小管和胆毛细管构成肝脏胆管树系统.虹鳟肝脏胆管结构及多种汇管区构型特点表明虹鳟肝脏胆管微循环结构系统发育完善,肝脏的物质代谢能力旺盛.     

Fluid flow stimulates tissue plasminogen activator secretion by cultured human endothelial cells

Wall shear stress generated by blood flow may regulate the expression of fibrinolytic proteins by endothelial cells. Tissue plasminogen activator (tPA) and plasminogen activator inhibitor, type 1 (PAI-1) secretion by cultured human endothelial cells were not affected by exposure to venous shear stress (4 dynes/cm2). However, at arterial shear stresses of 15 and 25 dynes/cm2, the tPA secretion rate was 2.1 and 3.0 times greater, respectively, than the basal tPA secretion rate. PAI-1 secretion was unaffected by shear stress over the entire physiological range.     

半肝切除术行门静脉阻断并结扎患侧肝动脉分支治疗肝癌的研究

目的：浅评半肝切除术的手术中延长断肝操作所需的入肝血流阻断时限和减少出血的方法。方法：门静脉阻断并结扎患侧肝动脉分支半肝切除术治疗肝癌。结果：本组19例阻断门静脉时间，量短20min，量长68min，平均38min；术中出血量：右半肝切除量少为350mL，量多为980mL，平均520mL；左半肝量少为180mL，量多为1020mL，平均为380mL。19例均在缝皮完毕30min内苏醒。术后2用肝功均快复正常。结论：半肝切除术断肝前行门静脉阻断并息仍肝动脉分支结扎明显优于传统的全蒂阻断法。     

过量铁和酒精引起大鼠肝损害的病理组织学变化

应用Ｈ．Ｅ．Ｐｅｒｌ＇ｓ，ＶａｎＧｉｅｓｏｎ和ＯｉｌＲｅｄＯ等染色法和光镜观察结果表明：酒精组的肝小叶中央静脉周围肝细胞脂肪变性；铁组的肝细胞和枯否氏细胞含大量铁质颗粒，单个细胞坏死，并出现局灶性炎症；酒精／铁组的小叶中央静脉周围与汇管区周围的肝细胞内积有大量铁质沉着体，结缔组织纤维化，并由汇管区逐渐扩展到小叶中央，呈铁沉着性肉芽肿。     

草被覆盖下坡面流土壤侵蚀水动力学特征

坡面侵蚀为水流和土壤互作过程,描述坡面流基本水力学特征,阐明土壤分离情况与坡面流侵蚀水动力学间关系,对了解坡面流侵蚀过程及治理坡面水土流失具有重要意义。以北京市山区野外径流小区不同植被密度、植物布设方式坡面为研究对象,以5°坡为例,在不同流量(1.0、2.0和3.0 m~3·h~(-1))下作放水冲刷试验,描述各坡面水力学及侵蚀水动力学特征,分析坡面土体土壤分离速率与水动力学参数关系。结果表明,径流雷诺数随径流冲刷流量增加而增加,植被密度对坡面流流态作用明显,植株布设方式对雷诺数影响较小;弗劳德数对其过程表征作用不显著;各坡面土壤分离速率为流量增函数(R~20.916),总体随冲刷时间延长波动性先增后减,土壤分离速率动态变化随植株布设密度增加而增加,行排列坡面抗蚀性差;径流剪切力和水流功率可与坡面土壤分离速率线性拟合,均呈线性正相关。研究结果为探究坡面流土壤侵蚀机理及治理方法提供依据。     

马莲河流域日径流过程分维与土壤侵蚀关系初探

对马莲河流域各水文站的日径流过程形态分维进行了对比分析。结果显示,同一流域干流的日径流过程分维值要明显大于支流的分维值,下游大于上游,4个水文站分维值年际变化趋势基本保持一致。从日径流过程分维与土壤侵蚀的拟合研究发现,日径流过程分维值与土壤侵蚀存在密切的相关性。     

翘嘴鲌和大鳍鳠和斑鳜肝脏的比较解剖

对翘嘴鲌、大鳍鳠和斑鳜肝脏进行了比较解剖观察,描述了3种鱼肝脏的的外形特征、门静脉、肝管及胆囊。在3种鱼比较解剖的基础上,讨论了鱼类肝脏的位置及外形特征,翘嘴鲌肝脏的2种特有结构,鱼类的肝门及门静脉;进一步探讨了3种鱼肝脏解剖学的进化水平。     

基于SRTM DEM的陕南汉江上游流域水文特征模拟研究

选取陕南汉江上游流域为研究样区,采用SRTM DEM作为基础数据,探讨ArcGIS9.2的水文分析扩展模块提取水文特征信息的方法,并利用该模块进行研究区水文特征提取,得到研究样区的水流方向数据、汇流累积量、河网水系、子流域边界等信息。同时,对所提取的河流网络进行有效性检验。通过与我国国家基础地理信息系统提供的5级以上河流水系数字线划图对照比较以及河网套合差的计算,发现基于SRTM DEM,采用ArcGIS软件能够提取出陕南汉江上游流域5级以上河流,提取的流域水文特征信息是有效合理的。该研究为该地区的洪涝灾害治理和生态规划建设提供依据。