Characterization and expression of a cDNA, AmphiSDHD,encoding the amphioxus cytochrome b small subunit in mitochondrial succinate-ubiquinone oxidoreductase

In this study, an amphioxus cDNA, AmphiSDHD, encoding the cytochrome b small subunit in mitochondrial succinate-ubiquinone oxidoreductase, was isolated from the gut cDNA library of amphioxus Branchiostoma belcheri tsingtauense. It is 1429 bp in length, with an open reading frame of 465 bp coding for a protein of 154 amino acids. The deduced protein contains a mitochondrial targeting presequence of 65 amino acids rich in basic residues like arginine and hydroxy residues such as serine and threonine. Alignment of the amino acid sequences of AmphiSDHD and other eukaryotic SDHD proteins showed that AmphiSDHD has three transmembrane segments, and includes two histidine residues in the second transmembrane segment that are the putative binding sites for the heme b molecule. The phylogenetic tree constructed suggests that AmphiSDHD appears more closely related to vertebrate SDHD proteins than invertebrate ones. Northern blotting demonstrated that AmphiSDHD is ubiquitously expressed in amphioxus, being in line with the fact that SDHD is a house-keeping protein.     

Phosphatidylglycerol effect on oxygen-evolving activity in Ca2+-depleted photosystem Ⅱ

The effect of anionic phosphatidylglycerol (PG) on oxygen evolution in a photosystem Ⅱ (PSⅡ) particle depleted of Ca2+ (designated dCaPSⅡ) has been investigated. The major finding is the observation of a new role of PG in the PSⅡ function. That is, PG restores nearly the lost oxygen evolution in dCaPSⅡ particle owing to Ca2+ depletion to the levels in intact PSⅡ. Furthermore, there is a stimulation of oxygen-evolving activity in the dCaPSⅡ complexed with PG in the presence of exogenous CaCl2, which PG enhances increasingly oxygen evolution with increasing CaCl2 concentration. It is suggested that PG-induced oxygen evolution recovery of dCa PSⅡ particle results from resumption of normal structure in protein by PG effect, whereas the enhancement of oxygen evolution in complex subject to CaCl2 is ascribed to the optimization of such a structure due to coordination complex formation of Ca2+ ions with PG.     

IGF-Ⅱ and IGFBP-1 reversely regulate blastocyst implantation in mouse

Insulin-like growth factor (IGF)-Ⅱ and IGF binding protein (IGFBP)-1, members of IGF family, are important in the cyclic development of endometrium and the blastocyst implantation. In the present study, the indirect immunofluorescence showed that IGF-Ⅱ and IGFBP-1 were specifically expressed at the maternal-fetal interface. In a co-culture system, IGF-Ⅱ significantly enhanced the attachment and outgrowth of the blastocyst on monolayer of uterine epithelial cells, while IGFBP-1 did not affect the blastocyst attachment, but markedly inhibited the blastocyst outgrowth. The results of zymography showed that IGF-Ⅱ enhanced the activities of MMP-2 and MMP-9, while IGFBP-1 did not affect the activities of MMP-2 and MMP-9. In conclusion, the equilibrium between the invasion of trophoblast and the inhibition of deciduas may be regulated by the interaction between the IGF-Ⅱ-expressing invading cytotrophoblast and maternal deciduas-derived IGFBP-1.     

Depletion of phosphatidylglycerol head-group induces changes in oxygen evolution and protein secondary structures of photosystemⅡ

The techniques of oxygen electrode polarography and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the roles of polar head-group of phosphatidylglycerol (PG) molecules in the functional and structural aspects of photosystemⅡ(PSⅡ) through enzymatic approach. It was shown that the depletion of PG by treatment of phospholipase C (PLC) on PSⅡ particles caused the inhibition of oxygen evolving activity in PSⅡ. This effect also gave rise to changes in the protein secondary structures of PSⅡ, that is, an increase in α-helical conformation which is compensated by the loss of β-strand structures. It revealed that the head-group of PG molecules plays an important structural role in the maintenance of normal structure of PSⅡ proteins, which is required to maintain the appropriate physiological activity of the PSⅡ complex such as the oxygen evolving activity. It is suggested that there most probably exist hydrogen-bonding interactions between PG molecules and PSⅡ proteins.     

Urotensin Ⅱ increases endothelin production by vascular smooth muscle cells in rats

The aim of this study was to observe the effects of urotensin Ⅱ (UII) on production of endothelin (ET) in rat aortic vascular smooth muscle cells (VSMC). Cultured VSMCs incubated with various concentrations of UII were used to measure the VSMC 3H-TdR incorporation, the amount of ET mRNA and ET production in VSMCs. In this work we found that UII (10-10-10-8 mol/L) promoted VSMC 3H-TdR incorporation (47%-83%, P < 0.01) and increased the amount of ET mRNA by 17.1% (P < 0.05) to 112.8% (P < 0.01), respectively, in a concentration dependent manner compared with control. After 4 and 8 h incubation, 10-10-10-8 mol/L of UII elevated the ET synthesis and release in a concentration dependent manner. After 4 h incubation, the content of ET in medium was 4.9, 5.36 and 7.12 pg/mL (P < 0.01). After 8 h incubation, the ET content released from VSMCs was 12.6, 12.07 and 17.17 pg/mL (P < 0.01). In addition, it was found that BQ123, a specific ETA receptor antagonist, obviously decreased the VSMC DNA synthesis induced by UII. The results of this study showed that UII could stimulate the ET mRNA expression and ET production in VSMC. The effects of UII on VSMC DNA synthesis were partly mediated by ET autocrine pathway. It suggests that the interaction between UII and ET plays an important biological regulating role as endogenous active peptides.     

强右Ⅱ逆半群的特征

作为强Ⅱ逆半群的推广，引入了强右Ⅱ逆半群的概念，并给出了这类半群的特征，然后得到了强右Ⅱ逆半群分别是（１）ＧＶ－半群；（２）强Ⅱ逆半数的充分必要条件。     

Regulation of angiotensinⅡon Gaq/11 protein of vascular smooth muscle cell and its underlying mechanism

To study the regulation of angiotensin Ⅱ(Ang Ⅱ) on Gαq/11 protein of vascular smooth muscle cell (VSMC) and its underlying mechanism, the protein synthesis was detected by [3H]-leucine incorporation. G?q/11 expression was measured by Western blot in cultured VSMC of rat aorta. The results showed that the level of G?q/11 was downregulated after stimulated by AngⅡ for 1-6 h, while it was upregulated significantly by 12-24 h stimulation (P < 0.01) in VSMC. The [3H]-leucine incorporation of VSMC was increased after 24 h Ang Ⅱ stimulation. The biphase regulation of Ang Ⅱ on G?q/11 protein was blocked by the Ang Ⅱ type Ⅰ receptor (AT1) specific antagnist losartan or PLC inhibitor U73122, while PD98059 did not have this effect. These data indicated that Ang Ⅱ contributed to VSMC hypertrophy by regulating the level of G?q/11, and this effect was mediated mainly through AT1 receptor-PLC signal transduction pathway.     

Adrenomedullin inhibits the endothelin production in-duced by urotensin Ⅱ in rat vascular smooth muscle cells

The aim of this study was to observe the effects of adrenomedullin (ADM) on endothelin (ET) production induced by urotensin Ⅱ (UⅡ) in rat vascular smooth muscle cells (VSMCs). Cultured VSMCs which were incubated with UⅡ (10-8 mol/L) and with various concentrations of ADM were used to measure the VSMCs 3H-TdR incorpora-tion, the activity of extracellular signal-regulated kinase(ERK), the amount of ET mRNA and ET production inVSMCs. In this work we found that incubation with UⅡ(10-8 mol/L) increased obviously the amount of ET mRNA inVSMCs and ET production in medium, however,co-incubation with ADM (10-10-10-8 mol/L) and UⅡ(10-8mol/L) reduced the amount of ET mRNA by 15%, 24% and45% (P< 0.01) respectively, compared with UⅡ alone. Thecontent of ET in medium was 14.13, 11.38 and 11.00 pg/mL. ADM alone (10-8 mol/L) had no effect on ET production inVSMCs. UⅡ (10-8 mol/L) promoted the 3H-TdR incorpo-ration and activity of ERK in VSMCs. ADM inhibited VSMCs 3H-TdR incorporation and activation of ERK in aconcentration-dependent manner. Compared with UⅡgroup, after co-incubation with ADM (10-10-10-8 mol/L)and UⅡ (10-8 mol/L) the VSMCs 3H-TdR incorporation wasdecreased by 7% (P > 0.05), 32% (P < 0.05) and 41% (P <0.01), respectively, and the activity of ERK was decreasedby 24% (P > 0.05), 32% (P < 0.05) and 36% (P < 0.05), re-spectively, in a concentration-dependent manner. The resultsshow that in cultured VSMCs ADM inhibits ET mRNA ex-pression, ET production and proliferation stimulated by UⅡ, and that inhibitory effect of ADM on UⅡ bioaction could be mediated through inhibiting MAPK pathway.     

基于MIB Ⅱ的IDS实现研究

讨论了IDS和网络安全管理的状况,给出了ID和NM相结合的异常入侵检测模型,即分布式和分等级的ID技术和NMS共存,充分利用NMS中MIB Ⅱ的信息,提出的分等级相关结构可以提高检测的准确率,识别协同入侵,尤其对DDoS这样的宏泛攻击很有效,这种技术在IDS和NMS的整合环境中可以发挥重要作用。     

Light and Heat Induced Denaturation of Photosystem Ⅱ Core Antenna Complex CP47

Light and heat induced denaturation of CP47, the core antenna complex of photosystem Ⅱ purified from spinach, were investigated using absorption and circular dichroism spectra.Light caused the destruction of chlorophyll a and excitonic interaction of chlorophyll a in CP47, while the protein secondary structure was not apparently changed.Heat induced the destruction of protein secondary structure and excitonic interaction of chlorophyll a, but the chlorophyll a molecule was not damaged.The results suggest that both the chlorophyll a molecular structure and the protein native conformation are necessary for excitonic interaction of chlorophyll a and the energy transfer function of the chlorophyll a binding protein.     

基于FPGA的视频编解码系统设计

结合Altera公司Cyclone Ⅱ器件中Nios Ⅱ嵌入式CPU内核开发板,进行视频编码、解码的硬、软件设计,制作成实物模块.讨论了视频编码、解码原理,对FPGA、CPLD逻辑器件进行深入学习和研究,设计了一套视频编码解码简易系统.     

具有铁磁偶合的新型双铜（Ⅱ）和双钴（Ⅱ）配合物

合成和表征了２个新的双金属配合物－［Ｃｕ（ＳＩＨ）］２·１／２％Ｈ２Ｏ和［Ｃｏ（ＳＩＨ）］２·１／２Ｈ２Ｏ，［ＳＩＨ］（２－）代表水杨醛异烟酰腙的脱氢阴离子］，其变温磁化率测定指出，两配合物双核单元中金属离子间存在着铁磁性相互作用。     

草酰二胺桥联的双核钴（Ⅱ）、镍（Ⅱ）和铜（Ⅱ）配合物的合成与磁性

已合成四种新的草酰二胺桥联的双核钴（Ⅱ）、镍（Ⅱ）和铜（Ⅱ）配合物：Ｃｏ＿２（ｂｐｙ）＿２（ｏｘｄ）（ＣｌＯ＿４）＿２（１），ＣＯ＿２（Ｍｅ＿２－ｂｐｙ）＿２（ｏｘｄ）（ＣｌＯ＿４）＿２·Ｈ＿２Ｏ（２），Ｎｉ＿２（ｂｐｙ）＿２（ｏｘｄ）（ＣｌＯ＿４）＿２·Ｈ＿２Ｏ（３），Ｃｕ＿２（Ｍｅ）＿２－ｂＰｙ）＿２（ｏｘｄ）（ＮＯ＿３）＿２（４），ｂＰｙ表示２，２＇－联吡啶，Ｍｅ＿２－ｂｐｙ表示４，４＇－二甲基联吡啶，ｏｘｄ表示草酰二胺阴离子。经元素分析、ＩＲ、电子光谱、ＥＳＲ、磁化率及变温磁化率的测定，对上述各配合物进行了表征。配合物（１）和（３）的变温磁化率已测定，其数值用最小二乘法和从自旋哈密顿算符导出的磁方程拟合，求得交换积分Ｊ为－１．４８ｃｍ￣（－１）和－１．８２ｃｍ￣（－１），表明配合物中钴（Ⅱ）－钴（Ⅱ）离子及镍（Ⅱ）－镍（Ⅱ）离子之间仅有极弱的反铁磁自旋交换作用。     

非离子表面活性剂Tween-80存在下5-Br-PADAP分光光度法测定微量Cu(Ⅱ)和Ni(Ⅱ)

在pH 3.50酸性介质中 ,Cu 和Ni 在非离子表面活性剂Tween - 80存在下 ,与5-Br-PADAP生成有色配合物 ,其最大吸收波长位于 575nm处 ;表观摩尔吸光系数分别为7.97× 10 4 L·mol- 1 ·cm- 1 和 1.0 2× 10 5 L·mol- 1 ·cm- 1 ;Cu 在 0～ 0 .52mg·L- 1 ;Ni 在0～ 0 .4 8mg·L- 1 范围内符合比耳定律 .用拟定的方法测定了钢样中的Cu 和Ni 含量 ,结果令人满意 .     

MRPⅡ系统中MRP分析与实践

物料需求计划MRP（Material Request Planning）是在制造资源计划系统中占有重要地位,是MRPⅡ系统实现的核心。MRP系统根据主生产计划、物料清单和库存信息计算生产对零件需求的详细信息。在分析MRP的工作逻辑和工作原理的基础上,针对MRP的计算逻辑及BOM的数据结构及处理方法等关键问题进行了深入研究,并提出解决方案。最后结合某机械加工厂的生产和运行实际,给出应用实例。     

鱼类主要组织相容性复合体Ⅱ类基因结构与表达分析的研究概况

MHCⅡ类分子在鱼类外源性抗原递呈,激活机体免疫应答中具有重要作用,文章对近年来鱼类MHCⅡ类基因组成、结构以及组织表达方面的研究进展进行了简述。     

基于Nios Ⅱ的双核处理器的设计与实现

NiosⅡ是Altera公司开发的嵌入式软核处理器,本文介绍了Altera NiosⅡ处理器及基于NIosll的多核处理器的工作原理,应用SOPC Builder工具建立双核处理器系统,以及使用NiosⅡ IDE为系统中每个处理器建立和调试软件工程.     

对苯二酚铜、钴(Ⅱ)配合物的合成及表征

采用半固相法合成一水合对苯二酚铜(Ⅱ)和一水合对苯二酚钴(Ⅱ),分别用碘量法和EDTA滴定法测定配合物中铜、钴的含量,通过元素分析、红外光谱、紫外吸收光谱、荧光光谱表征两种配合物的组成.结果表明:采用半固相反应法可以合成一水合对苯二酚铜(Ⅱ)和一水合对苯二酚钴(Ⅱ),在两种配合物的荧光光谱中都出现2个激发峰和1个荧光发射峰,说明过渡金属的对苯二酚配合物可用做潜在的发光材料.     

弱光和Tris处理条件下PSⅡ放氧核心复合物的损伤

弱光条件下(120μmol·m-2·s-1)用Tris(0.8mol/L,pH6.5～10.0)处理具有放氧活性的PSⅡ核心复合物,可引起33kD锰稳定蛋白的释放和锰复合物的破坏,并导致核心复合物的结构发生明显的改变.温和电泳、SDS-PAGE和双向电泳分析表明,主要是PSⅡ核心复合物的二聚体和单体减少,并且复合物部分解体;除反应中心D1和D2蛋白外,核心天线CP43和CP7的量也减少,33kD锰稳定蛋白要发生降解.避光时,PSⅡ核心复合物不受影响.