HBV相关肝病患者外周血NK细胞PD-1、Tim-3表达及意义

目的 了解HBV相关肝病患者外周血NK细胞表面PD-1、Tim-3的表达情况,探讨PD-1和Tim-3的表达与血清HBV-DNA载量的相关情况。方法 选择HBV感染相关肝病患者74例,其中CHB患者30例,LC患者24例,HCC患者20例,健康对照18例。应用流式细胞术检测NK细胞表面PD-1、Tim-3表达,荧光定量PCR检测HBV-DNA量,ELISA法检测细胞因子分泌水平。统计各组患者PD-1和Tim-3的表达率,比较各组差异,分析其与病情的相关性。结果 CHB、LC、HCC组外周血NK细胞表面PD-1和Tim-3的表达率分别为34.46%±7.31%、59.09%±12.35%、61.49%±15.26%和19.18%±6.05%、28.64%±11.20%、31.24%±11.85%,均高于对照组（P<0.01）,LC组和HCC组明显高于CHB组（P<0.01）,LC组和HCC组比较无统计学差异。在CHB组,PD-1的表达率与HBV-DNA呈负相关关系（R=-0.437,P=0.033）。CHB、LC、HCC各组血清中细胞因子TNF-α和IFN-γ水平分别为0.66±0.63、0.75±0.66、0.85±0.71和1.76±0.88、1.83±1.23、1.60±0.53,均低于健康对照组（P<0.01）。结论 HBV相关肝病患者NK细胞表面PD-1、Tim-3表达均增加,且与病情严重程度有关,增加表达的PD-1与血清HBV-DNA载量存在负相关性,HBV肝病各组血清TNF-α、IFN-γ分泌减少。     

西太平洋副热带高压异常及其与1998年长江流域洪涝过程关系的研究

文中结合 1 998年长江流域的洪涝过程研究了太平洋的活动特征 ,探讨了副热带高压活动与海温的关系 ,以及视热源、水汽汇的特征与副高活动的关系等。首先描述了 1 998年太平洋副热带高压的基本特征 ,给出了它异常的季节位置、强度和形态 ,及其与长江流域降水异常的关系。SVD分析表明 ,1 997至 1 998年的 El Nino过程的演变特征所对应的太平洋副热带高压的最佳耦合模态是 :主体强而位置偏南 ,特别是其西部。赤道辐合带也偏弱 ;1 998年夏季副热带高压的基本特征正符合该模态的特征。热带地区东西向的垂直环流明显地出现东太平洋的异常上升气流与西太平洋的下沉距平气流。视热源、水汽汇的分布能很好地描写副热带高压区的季节位置和强度。副热带高压区为明显的 Q1<0的辐射冷却区和 Q2 <0的变干区。这种特征也有助于副热带高压区的维持。同样 ,视热源、水汽汇的分布也能很好地解释副热带高压区的季节内异常活动。在长江流域持续暴雨期和间隙期 ,Q1,Q2 所指示的副热带高压与雨带的相对位置有很大的差异。不同的热力结构能较好地解释副热带高压区的迅速南落 ,由此造成长江流域的二度梅     

Foraminiferal depth palaeoecology of Late Pliocene shelf sequences and systems tracts, Wanganui Basin, New Zealand

High-resolution foraminiferal census of benthic taxa was undertaken on 113 closely spaced samples drawn from the Late Pliocene (ca. 2.6−1.7 Ma) cyclothemic marine strata of the Rangitikei Group, eastern Wanganui Basin, New Zealand. These strata comprise a ca. 1 km thick progradational stack of twenty, sixth-order, depositional sequences that accumulated in shelf and shoreline palaeoenvironments. The sequences are correlated with δ¹⁸O Stages 100−58, and each 41 ka glaciallinterglacial stage couplet is represented by an individual sequence comprising transgressive (TST), highstand (HST), and regressive (RST) systems tracts.

Statistical analysis of the census data identifies thirteen foraminiferal associations within the cyclothemic strata, that are grouped into seven depth- and lithology-related biofacies spanning the entire range of marginal marine to outer shelf palaeoenvironments. Foraminiferal palaeobathymetric analysis of the Rangitikei Group sequences reveals cyclical changes in water-depth of ca. 100–200 m amplitude with frequencies corresponding to the 41 ka obliquity orbital rhythm. Water-depth changes of this magnitude are consistent with a glacio-eustatic origin for the cyclothems, which correspond to an interval of Earth's history when successive continental glaciations of the Northern Hemisphere are known to have occurred. Furthermore the derived water-depth changes are also consistent with lithofacies and sequence stratigraphic inferences regarding palaeodepth of the sequences.

Individual sequences display a clear deepening-upward trend from shoreline to mid-shelf water-depths within TSTs. The level of resolution provided by the microfaunal analysis was insufficient to resolve the precise position of the maximum flooding surface (MFS) and its relationship to the downlap surface (DLS). However, the turn around from rising to falling relative sea level (maximum water-depth) corresponds to a < 5 m interval of section spanning the top of TSTs and lower portions of HST's. A progressive shoaling trend to shoreline and marginal marine environments is indicated for the overlying RSTs.

The amplitudes of water-depth changes for asymmetrical sequences, Rangitikei_nt motif (nondepositional transgression) (100–200 m), are somewhat greater than glacio-eustatic sea-level changes derived from the deep-sea δ¹⁸O record (50–100 m). This implies a significant subsidence contribution to relative sea-level changes. Notwithstanding the effect of subsidence and sedimentation on relative sea level, fluctuations in glacio-eustatic sea level are regarded as the primary factor controlling relative sea-level changes recorded in the Late Pliocene Wanganui Basin succession. Foraminifer-derived palaeobathymetric cycles within sequences display the same frequency, relative magnitude and symmetry as their correlative cycles on the δ¹⁸O sea-level curve.     

南极15ka以来海洋沉积物的环境磁学研究

通过对东南极普里兹湾陆坡区ＮＰ９５－１及西南极长城湾ＮＧ９３－１两柱样系统的环境磁学研究，获得了南极地区１５．０～５．５ｋａＢ．Ｐ．以来的古气候变化序列。结果表明，磁学参数较好地记录了古气候变化及沉积环境变化的信息。ＮＰ９５－１柱样较好地记录了Ｈｅｉｎｒｉｃｈ１事件、新仙女木事件以及波令－阿罗德暖期，其中Ｈｅｉｎｒｉｃｈ１事件发生于１４．３ｋａＢ．Ｐ．，新仙女木冷期为１１．７～１０．３ｋａＢ．Ｐ．，１０．３ｋａＢ．Ｐ．以后，南极地区进入全新世。在全新世，两柱样记录了在１０．０ｋａＢ．Ｐ．及６．０ｋａＢ．Ｐ．前后两个暖期，其间夹有小幅气温下调的时段；６．０ｋａＢ．Ｐ．后，两柱样均有气候颤动变冷的记录。     

大地电磁二次函数插值的有限元法正演模拟

在矩形网格剖分情况下,讨论单元内采用二次函数插值的大地电磁二维有限元正演问题,推导出相应的计算公式,在解线性方程组求取各节点处的场值后,计算地表的电阻率和阻抗相位.通过与理论解析解及线性插值有限元法的计算结果的对比,证实了本文方法在网格剖分稀疏时,仍有高的计算精度,与线性插值法相比,采用放稀一倍的网格仍具有较高的计算精度,而两者的计算时间相差不多.     

农业系统地图在区域经济布局及规划中的应用

本文探讨了利用农业系统地图直接对区域经济布局及发展作出规划与预测,并将分析和解译地图的结果直接用于指导生产实践的可行性。结果表明,地图就是客观实际的科学模拟,可以揭示出自然与经济、经济系统内部的规律,是研究农业生产合理的规划和布局,发展区域经济和科学预测的极为有效的科学工具。     

海康盐场井水化离子与地震关系初探

本文对广东省海康盐场339^#深井8年来的水化观测资料进行了初步分析，认为该井Cl^-含量和Ca^ Mg^ 合量的下尝稳定型的，它们与气象等外界因素影响无明显关系，对一定范围内的地震活动具有震兆显示能力。     

Large-scale structure of magnetospheric plasma

Recent investigations of magnetospheric plasma structure are summarized under the broad categories of empirical models, transport across boundaries, formation, and dynamics of the plasma sheet. This report reviews work in these areas during the period 1991 to 1993. Fully three-dimensional empirical models and simulations have become important contributors to our understanding of the magnetospheric system. Some new structural concepts have appeared in the literature: the entry boundary and geopause, the plasma sheet region 1 vortices, the low-energy layer, the adiabaticity boundary or wall region, and a region in the tail to which we refer as the injection port. Traditional structural concepts have also been the subject of recent study, notably the plasmapause, the magnetopause, and the plasma sheet. Significant progress has been made in understanding the nature of plasma sheet formation and dynamics, but the acceleration of electrons to high energy remains somewhat mysterious.     

Microlensing and polarization

The discovery of the microlensing effect has found out the new population — dark bodies having mass of the order of 0.1M which form the halo of our Galaxy. There are two main criteria which identify a light curve as the reveal of the microlensing effect. They are symmetry of the light curve and equal amplification in different colors. We consider polarization of the light beam arising in microlensing effect and find that additional test is possible — polarization of light in the case of a finite star disk. Consequences of polarization are also considered.     

Light curve behaviour in C/1995 O1 (Hale-Bopp) — II

Comet Hale-Bopp is, without doubt, one of the most important objects for cometary science which has ever been observed. The light curve is well-observed from a heliocentric distance 7.2 AU and some information is available at distances as great as 17 AU. This allows the photometric evolution of the comet to be studied as different volatiles dominate the activity. Three different phases of activity are seen as the heliocentric distance reduces during 1996: the initial phase of very fast brightening, characterized by a r ^–5 law; a standstill in the light curve when the brightening law reduced to r ^–1, which coincides with the initiation of water sublimation at r ~ 4 AU; and a further phase of more rapid brightening with an r ^–3.5 law, similar to the mean for comets classed as fairly new, which initiated at r ~ 4 AU.