缺氧预适应对小鼠常压耐缺氧存活时间的影响

目的：观察缺氧预适应对小鼠常压耐缺氧存活时间的影响。方法：对小鼠先施加短暂的缺氧至喘息，30分钟后进行致死性缺氧，观察其存活时间并与对照组比较。结果：缺氧预适应组小鼠的存活时间为24．0±3．30分，而空白对照小鼠的存活时间为19.28±3．92分，两者具有显著差异（P＜0．01）。结论：缺氧预适应能延长小鼠的耐缺氧存活时间。     

龙芽楤木皂苷诱导心肌预适应对缺血再灌注后离体心脏血流动力学变化影响的研究

目的研究龙芽楤木皂苷诱导心肌预适应对缺血/再灌注后离体心脏血流动力学变化的影响.方法成年雄性Wistar大鼠40只,随机分成空白对照组(Co组)、心肌缺血预适应组(IPC组)、单纯缺血组(IC组)、龙芽楤木皂苷给药组(As组),每组10只,各组动物预处理后,行Langendorff离体心脏灌流.观察再灌注后10,20,30 min时间段左室收缩压(LVSP)、左室舒张末压(LVEDP)、室内压最大上升速率( dp/dt)、室内压最大下降速率(-dp/dt)、主动脉流量(AF)及心率(HR),同时记录Ⅱ导联心电图并观察心率(HR)及心律失常发生情况.结果观察大鼠Langendorff离体灌流心脏在缺血/再灌注后血流动力学的变化,发现AS组与IC组相比:其各项心功指标恢复较好(P<0.05,P<0.01),5 min之内室颤(VF)发生率较低,心律失常评分较低(P<0.01).而与IPC组相比:其二者各项心功指标恢复均较好,除20,30 min的LVSP有较小差别外(P<0.05),其他指标无显著性差异(P>0.05);其二者5 min之内室颤发生率均较低,心律失常评分均较低,且无显著性差异(P>0.05).结论龙芽楤木皂苷能够诱导心肌预适应,对离体大鼠心脏缺血/再灌注期的心室收缩与舒张功能障碍有显著的改善作用,也有较好的抑制心律失常发生的作用.因此,有待对龙芽楤木皂苷进行更深入的研究,以探讨其在心血管方面的作用及在心血管病高危人群中的应用.     

缺血性预适应时心肌保护的可能机制—腺苷作用

阐述了缺血预适应心肌保护现象,作为保护性物质—腺苷在该过程中起重要作用.     

心脏缺血性预适应与蛋白激酶C作用

缺血性预适应对心脏起着有效的保护作用,而蛋白激酶C参与了保护过程.     

渐进性低氧预适应对小鼠游泳能力的影响

目的是观察常压低氧预适应对小鼠运动能力的影响 .其方法为 :雌性昆明小鼠 2 4只 ,随机分为对照组 ,实验 1组 ,实验2组 (n =8) .实验组经 7天重复低氧预适应 ,每天 4次 ,实验 1组每次 12min ,常氧休息 5min ,实验 2组每次 8min ,常氧休息 5min .第8天进行无负重力竭性游泳运动 .其结果为 :三组运动至力竭时间分别为 2 45± 5 7min、15 9± 3 9min、184± 14min ,P <0 .0 5 .其结论为 :小鼠经 7天低氧预适应 ,可提高其游泳运动能力 .     

热预适应对大鼠肌肉组织中m6A修饰的影响

为了解大鼠肌肉中m⁶A修饰在热预适应过程中的变化，并初步探讨m⁶A在热预适应过程中发挥的作用.选用24只成年雄性SD大鼠，随机分为2组，12只为预热组，12只为对照组.热预处理组是42℃热处理15 min,每天3次，连续5 d,对照组不做任何处理.处理结束后检测关键酶的转录和翻译表达水平，以及总m⁶A的变化.与对照组相比，热预处理组的甲基转移酶METTL3和METTL14,KIAA1429的mRNA表达水平均有不同程度上升，METTL3最为显著；去甲基化酶FTO和ALKBH5的mRNA水平下降，FTO蛋白表达水平下降极显著；LC-MS检测发现m⁶A修饰水平升高.在热预适应过程中，大鼠骨骼肌中m⁶A甲基化修饰增强，去甲基化减弱，总体m⁶A水平升高，表明m⁶A信号通路在大鼠肌肉预适应过程中可能发挥正调控作用.     

缺氧预适应小鼠海马脑区VEGF蛋白表达增加

目的 观察重复低氧对小鼠海马组织内血管内皮生长因子(vascular endothelial growth factor,VEGF) 蛋白质表达的影响.方法 小鼠随机分为3组,分别暴露低氧0次(H0),1次(H1),4 次(H4)后取海马组织,应用 Western Blot 技术,检测小鼠海马组织内VEGF的蛋白表达变化.结果 实验发现,H0,H1和H4组海马组织内VEGF均表达,H1组与H0组之间没有差异,H4组显著升高（P<0.05,vs. H0 and H1）.结论 VEGF在急性低氧预适应小鼠海马组织表达增加可能参与预适应的形成及脑保护.     

间断性跪坐缺血预适应方法的探索及应用

目的测定并比较两种方法导致下肢缺血再灌注时腓肠肌肌氧含量,建立间断性跪坐缺血预适应的方法,并观察应用该方法产生的远程缺血预适应(RIPC)对前臂皮肤毛细血管脆性的影响。方法1)12人次进行腓肠肌肌氧含量测试:以跪坐法或血压带200 mmHg加压束缚大腿法阻断下肢血流,以缺血5 min后复灌5 min为一个回合进行下肢缺血再灌注,测试受试者腓肠肌同一部位在不同时间点的肌氧含量,连续进行3个回合为实施一次RIPC,比较两种方法下的肌氧含量变化差异。2)61人分为实验组(34人)和对照组(27人)参加毛细血管脆性实验:每天以间断性跪坐实施RIPC 30 min,观察实施前、实施2周(部分人)及4周后血压及前臂皮肤毛细血管脆性的变化。两组中各有14人于实验前后测试血小板。结果1)两种缺血再灌注方法均可引起腓肠肌肌氧含量的规律性改变,即阻断下肢血管时肌氧含量显著降低,恢复血管灌流后肌氧含量迅速恢复至正常值上下。相比于血压带加压束缚法,跪坐时腓肠肌肌氧含量降低更加迅速、完全;2)间断性跪坐4周后,实验组毛细血管脆性显著降低,出血点数量明显减少,与对照组比较差异有统计学意义。血压值及血小板数量在正常范围内无明显改变。结论间断性跪坐通过间断性阻断腘动脉使腓肠肌等下肢组织产生缺血预适应,反复实施4周可以使前臂毛细血管脆性降低,质量改善,是一种简单易行的实施RIPC的有效方法。     

缺氧预适应小鼠脑匀浆提取液对Hep G2细胞缺氧耐受性的影响

目的:探讨缺氧预适应小鼠脑匀浆提取液(HP)对Hep G2细胞缺氧耐受性的影响.方法:用4种浓度的HP作用于缺氧(2%O2)培养HepG2细胞,以同浓度正常小鼠脑匀浆提取液(NP)作对照,检测了在缺氧培养后,Hep G2细胞的MTT值、早期凋亡率(Annexin V-FITC/PI双染流式细胞仪检测)、晚期凋亡率(Hoechst33258染色荧光显微镜检测).结果:低浓度HP对Hep G2细胞有保护作用,而高浓度HP对Hep G2细胞有损伤作用.结论:HP的作用有浓度依赖性和时间依赖性.     

盐预适应对鲁氏酵母菌高盐胁迫抗性的影响

为进一步提高鲁氏酵母菌的高盐胁迫抗性,采用预适应处理的方法,研究了盐预适应对鲁氏酵母菌(Zygosaccharomyces rouxii CGMCC 3791) 高盐胁迫抗性的影响。研究结果表明,经过质量浓度为60、120、180g/L的NaCl预适应前处理90min后,鲁氏酵母菌在质量浓度为350g/L的饱和NaCl胁迫条件下的存活率分别提高到处理前的2.05、2.53、1.92倍。进一步分析了120g/L NaCl预适应前处理90min对细胞生理特性的影响,结果表明:经过盐预适应前处理后,细胞在盐胁迫条件下的胞内pH值和Na⁺/K+-ATPase活力显著高于未经盐预适应处理而直接进行盐胁迫的细胞；并且细胞膜饱和脂肪酸(棕榈酸C16:0,硬脂酸C18:0)的相对含量分别减少至处理前的93%和60%,不饱和脂肪酸(棕榈油酸C16:1,油酸C18:1和亚油酸C18:2)的相对含量分别增加到处理前的2.55、1.78、1.39倍,细胞不饱和度增加到处理前的2.28倍；胞内游离丝氨酸、苏氨酸和赖氨酸的含量显著提高。研究结果旨在进一步理解鲁氏酵母菌抵御高盐胁迫的耐受机制,为鲁氏酵母菌抗逆性能的提高和工业应用提供一定的理论参考。     

解具特殊系数矩阵线性代数方程组的预条件迭代法

文章考虑具有更优特性的分块矩阵，（具有性质A的矩阵），给出了预条件Jacobi、Gauss—Seidel、对称Gauss—Seidel迭代矩阵与传统块Jacobi迭代矩阵二者特征值之间的关系，作为应用，选取某个恰当的预条件因子，在传统块Jacobi迭代法不收敛的情况下，预条件块迭代法能收敛．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。