亚欧大陆内心区旅游资源分区评述

本文根据亚欧大陆内心区旅游资源分布特点以及开发利用程度、旅游资源的地域分异性及自然和人文条件的差异,在内心区划分出不同的旅游亚区,并进行旅游资源分区评述,提出今后的开发设想。     

我国心脑血管病的医学气象研究

回顾了20世纪80年代以来我国心脑血管病医学气象研究的主要成果，总结分析了这些研究的结论、进展和不足，提出加强和改进此类研究的建议和对策。     

中国对虾PENAEUS CHINENSIS(O''''SBECK)心脏形态及超微结构的研究

描述中国对虾心脏形态及超微结构。1.心脏存在第四对心孔,心脏壁由心外膜与心肌层组成,心孔的瓣膜处无心外膜,心肌束从不同方向穿越心脏而形成三维网状结构。2.心肌内膜系统由肌质网、横管系和Tz管系组成;肌节A带、I带和H带分明,Z线清晰,二联体或三联体出现在H带处。3.心脏神经包括自主系统及背神经系统,前者由神经节干及其分支组成,神经节干包含5个大神经细胞和4个小神经细胞;后者由一对背神经及其合成的一支背神经干组成。     

The auriferous late Archaean sedimentation systems of South Africa: unique palaeo-environmental conditions?

Studies of the auriferous Witwatersrand placers and associated rocks have revealed that certain palaeo-environments, especially braided fluvial, are particularly well represented in this part of the rock record. However, there is a paucity of lithofacies indicating certain other palaeo-environments. Possible reasons for their scarceness or absence are suggested in this paper. It is generally assumed that pre-vegetational fluvial systems would have been characteristically braided, because of the absence of land plants necessary to stabilise river banks. A question arising is what kind of downstream changes such pre-vegetational braided streams underwent. A recent study of a braided stream placer revealed that the depositing system retained its braided character right down to the palaeo-shoreline. However, gravel did not reach the palaeo-beach. As with many modern examples, beach conglomerates are rare in the Witwatersrand rocks. The paucity of conglomeratic beach placers is ascribed to the low probability of gravel being transported across coastal plains, because of the relatively low slopes or depths of rivers here. The Witwatersrand fluvial channels are generally considered to have had high width-to-depth ratios, because of the absence of land vegetation to stabilise channel banks. However, two examples of deep, relatively narrow scour features, with predominantly fine-grained fills, occur near the base of the Central Rand Group. The low width-to-depth ratios of these scour features, which probably represent palaeo-valleys, are ascribed to severe incision during a rapid sea-level fall. The auriferous fluvial systems of the Witwatersrand are generally considered to have been entirely braided, due to the lack of bank stability. However, the fluvial B placer of the Welkom goldfield is confined to discrete channels. Their banks are thought to have been stable, due to the cohesive nature of the lutite into which the gravelly streams incised. In addition, braiding sensu stricto was probably inhibited by initial incision and a low sediment supply. No deposits of specifically deltaic sub-environments have been found in the Central Rand Group. Their absence is attributed to the following factors: (a) the paucity (absence?) of well-defined palaeo-river mouths; (b) low concentrations of suspended sediment; (c) intermittent sediment supply to the palaeo-coastline; and (d) reworking by tidal and longshore currents. Alluvial-fan deposits are also apparently absent in the Witwatersrand rocks. The absence of fan deposits is attributed to the poor potential for development and preservation of fan deposits in the compressive tectonic setting proposed for the Witwatersrand Basin. Although ventifacts have been found in the Witwatersrand rocks, no aeolianites have been reported. Their apparent absence is probably due to (a) reworking in a predominantly humid climate, and (b) transport of sand by dominant winds to areas unfavourable for the preservation of aeolianites.     

褐点石斑鱼三种组织细胞系的建立

为建立褐点石斑鱼鳍、心脏和鳔组织细胞系,本文利用不同培养液和培养温度对褐点石斑鱼鳍、心脏和鳔组织细胞进行了原代培养和传代培养。实验结果显示,在24℃培养于含有羧甲基壳寡糖、碱性成纤维样生长因子、I型胰岛素样生长因子及20%胎牛血清的DMEM/F12培养液(pH=7.2)中的3种细胞,均为成纤维样细胞,其生长分裂状态最佳,可以持续稳定传代。第60代褐点石斑鱼鳍、心脏和鳔细胞的群体倍增时间分别为50.6 h、40.3 h和43.3 h,其特征性染色体数目均为48条。目前鳍、心脏和鳔细胞已分别传至第90代、第70代和第75代,已成功建立了3种细胞的连续性细胞系,为鱼类病毒与宿主细胞相互作用机制等鱼类病毒学基础研究,以及鱼类病毒的分离、鉴定、繁殖及病毒疫苗研制等奠定了基础。     

飞机草提取物对斑马鱼心、脑毒性的病理组织学影响

制备飞机草95%(φ)乙醇提取物冻干粉,以200、500、800mg/L3种用量对斑马鱼进行水浴染毒,21d后取斑马鱼的心和脑制作病理组织切片,显微观察。结果表明,提取物冻干粉导致斑马鱼心肌细胞溶解,萎缩,严重时坏死,脑组织局灶性炎性细胞浸润、血栓形成和各细胞层结构变化,随着提取物冻干粉含量的增大,斑马鱼心、脑的病理组织学变化更加明显。乙醇提取物的冻干粉对斑马鱼的心、脑具有较大的毒性作用。     

冠状动脉前瞻性心电门控窄窗采集技术在320排螺旋CT中的应用

目的：探讨使用320排螺旋CT前瞻性心电门控窄窗采集技术,在降低辐射剂量方面的应用。方法：研究组50例采用前瞻性心电门控技术,对照组50例患者采用回顾性心电门控技术,分别测量两组间图像质量以及辐射剂量。结果：两组数据比较,患者的基本情况如年龄、心率、体重和体重指数以及图像质量差异无统计学意义（P〉0．05）,有效放射剂量两组间的差异有统计学意义（P=0．0001）,前瞻性心电门控组辐射剂量（8．80±2．78）mSv显著低于回顾心电门控组（25．82±8．84）mSv。结论：前瞻性心电门控窄窗采集技术在确保图像质量的同时可以降低辐射剂量。     

Variations in cardiac activity following acute exposure to copper in three co-occurring but differently zoned Mediterranean limpets

The cardiac activity of three limpets (Patella rustica, P. caerulea and P. aspera), having a different vertical zonation on the Mediterranean rocky shores, was monitored using a non-invasive technique, during 6 h exposure to copper solutions (0.1 and 0.5 ppm), and after return to copper-free conditions. At 0.1 ppm no significant variation of heart rate was observed in the three species with respect to control conditions, while after 3 h at 0.5 ppm a consistent bradycardia was evident in P. caerulea and P. aspera, but not in P. rustica. After 6 h at 0.5 ppm most of the specimens of the three species were acardic but still reactive to mechanical stimulation. Tests on the resumption of cardiac activity after 6 h exposure to 0.5 ppm showed that even after a prolonged cessation of cardiac activity, limpets quickly resumed heartbeating once returned to clean seawater. However, recovery of heartbeating was faster in the mid- and high-shore species (P. caerulea and P. rustica, respectively) than in the lower-shore P. aspera. Moreover, the cardiac pattern upon recovery was definitely bradycardic in P. aspera, while the other two species showed a significant overshooting in heartbeating rate. Measurement of body burdens of copper showed that P. rustica and P. caerulea were faster in removing the excess of copper than the lower-shore P. aspera. In conclusion, this study showed that taxonomically close and syntopic species having a different zonal distribution exhibit different cardiac responses to waterborne copper and stresses the importance of comparative studies on physiological responses of organisms to metal pollution.     

伊朗黄土高原表土磁性特征与古气候指示意义

全球变化研究中的现代过程研究越来越成为定量重建工作的先决前提,而由于如黄土等气候记录载体沉积分布的全球性与沉积环境的多样性,更需要就具体的研究区进行有针对性的现代过程工作以最大程度地保证重建工作的可靠性.西起地中海、东至帕米尔的广大区域是丝路文明演化的关键地区,其过去气候变化也是了解北半球中纬度气候演化与机制的重要拼图...     

多排螺旋CT冠状动脉造影结合超声心动评价冠心病

目的 评价多排探测器螺旋CT(multi-detect row computed tomography MDCT)冠状动脉造影结合超声心动图对冠心病的诊断价值。 材料方法 收集2002年-2003年间54例临床怀疑或确诊的冠心病患者。所有患者进行MDCT(美国GE公司四排探测器螺旋CT)冠状动脉造影及超声心动(美国惠普公司5500超声)检查,其中30例患者在CT和超声检查前后2周范围内进行了选择冠状动脉血管造影检查(selected coronary angiography SCA),并以此为金标准,对MDCTA结合超声心动图诊断冠心病的价值进行评估。 结果 54例患者中,42例患者显示56支冠状动脉病变;超声心动发现左室舒张功能障碍24例。30例SCA显示25例患者38支冠状动脉病变(左冠32支,右冠6支)。MDCT冠脉造影结合超声心动法与SCA法检查结果一致性为:92.86%,X²检验:X²=0.5;0.5>P>0.25,无显著性差异。 结论 MDCT冠脉造影扫描可以作为冠状动脉狭窄性冠心病的初步筛选手段,结合超声心动图有利于提高诊断准确性。