青鳉与三刺鱼嗅觉受体(OR)基因的鉴定与进化分析

嗅觉是动物至关重要的感官,而嗅觉受体基因则构成了嗅觉的基础.嗅觉受体跟环境气味分子的相互作用被认为是嗅觉过程发生的第一步.气味分子结合被认为发生在由跨膜区形成的一个口袋结构中,而直接结合位点叫做绑定位点.以往的研究显示,绑定位点可能因为功能分化而受到正向选择.本研究对青鳉和三刺鱼的基因组中鉴定了OR基因,并对这些序列进行了进化分析.通过不同跨膜区与整个编码区的选择压力的比较,发现跨膜区4,5,6有较高的平均Ka/Ks值,这可能在某种程度上由正向选择所致.同时发现,许多受正向选择的位点主要分布在跨膜区.通过

云南基诺族及汉族特发性全面强直-阵挛性癫(癎)与CLCN2基因的相关性

目的 研究氯离子通道CLC-2基因是否与中国云南地区基诺族及汉族特发性全面强直-阵挛性癫(癎)(IGTCS)相关.方法 以14例云南西双版纳傣族自治州景洪市基诺乡基诺族IGTCS患者及其16名未发病亲属、67例云南籍汉族IGTCS患者及57名云南籍汉族健康体检者为对照,对常染色体3q26上CLCN2基因的内含子2及外显子5、19(内含子18)进行研究,采用PCR及直接基因测序技术,应用病例-对照研究法对CLCN2基因与云南基诺族及汉族IGTCS进行相关性分析.结果 CLCN2基因的内含子2及外显子5、19在病例组和对照组中均没有发现已报道的易患突变,但我们在对外显子19的序列测定过程中发现了其上游内含子18的146位上存在1个单核苷酸多态性位点:146T→C.该位点的3种基因型(TT、TC、CC)在汉族病例组(9、3、29例)和汉族对照组(22、9、26例)之间的分布差异有统计学意义(x2=16.079,P＜0.05);在基诺族组(基诺族病例组+基诺族亲属组,6、12、12例)与汉族对照组(22、9、26例)之间分布差异亦有统计学意义(x2=7.027,P＜0.05).汉族病例组与汉族对照组间TT型与非TT型基因型(分别为9、32例和22、35例)、TC型与非TC型基因型(分别为3、38例和9、48例)比较差异有统计学意义(x2=10.694,OR=4.121,P＜0.05;x2=11.592,OR=0.238,P＜0.05).结论 CLCN2基因内含子18的多态性位点146T→C可能是中国云南地区基诺族与汉族IGTCS患者的1个相关性位点,且在本组有限的样本数量研究中,此SNP位点在两个民族IGTCS患者之间的分布无民族差异.基因型TT为IGTCS的1个保护性因素,基因型TC则增加了患者的易患性.

Polymerase chain reaction based C4AQ0 and C4BQ0 genotyping: association with systemic lupus erythematosus in southwest Han Chinese

Objective: To investigate the association of complement C4 null genes (C4QO, including C4AQO and C4BQO) and C2 gene with systemic lupus erythematosus (SLE) in southwest Han Chinese; 136 patients with SLE and 174 matched controls were genotyped. Methods: C4 null genes were determined by a polymerase chain reaction (PCR) procedure with sequence specific primers (PCR-SSP). The 2 bp insertion in exon 29, which was previously identified in non-Chinese populations and caused defective C4A genes, was directly typed by sequencing the whole exon 29 using exon specific primers. The exon 6 of complement C2 was also sequenced in both the patients and controls. Results: The frequency of homozygous C4AQO allele was 12.5% (17/136) in patients with SLE compared with 1.1% (2/174) in controls (p<0.001, odds ratio (OR)=12.286, 95% confidence interval (95% CI) 2.786 to 54.170). There was no significant difference for homozygous C4BQO allele between patients with SLE and controls (p=0.699). Patients with the C4AQO gene had an increased risk of acquiring renal disorder, serositis, and anti-dsDNA antibodies compared with those without C4AQO (for renal disorder, p=0.018, OR=8.951, 95% Cl 1.132 to 70.804; for serositis, p=0.011, OR 4.891, 95% CI 1.574 to 15.198; for anti-dsDNA, p=0.004, OR 7.630, 95%Cl 1.636 to 35.584). None of the patients or controls had the 2 bp insertion in exon 29 of the C4 gene. The type I C2 deficiency was not detected in the 3 10 samples. Conclusion: It is suggested that deficiency of C4A (not due to a 2 bp insertion in exon 29), but not C4B or C2, may be a risk factor for acquiring SLE in south west Han Chinese; this results in increased risk of renal disorder, serositis, and anti-dsDNA antibodies in patients with SLE. Racial differences seem to be relevant in susceptibility to SLE.

Environmental enrichment and chronic restraint stress in ICR mice: Effects on prepulse inhibition of startle and Y-maze spatial recognition memory

In most studies regarding the improving or therapeutical effects induced by enriched environment (EE), EE was performed after the stress treatment or in patients with certain diseases. In the current study, the effects of chronic restraint stress (6 h/day) in mice living in an enriched environment or standard environment (SE) were tested. Mice were randomly divided into 4 groups: non-stressed or stressed mice housed in SE or EE conditions (SE, stress + SE, EE, stress + EE). Prepulse inhibition (PPI) of startle was tested after the 2 weeks or 4 weeks stress and/or EE treatment and 1 or 2 weeks withdrawal from the 4 weeks treatment. After the 4 weeks treatment, spatial recognition memory in Y-maze was also tested. The results showed that EE increased PPI in stressed and non-stressed mice after 2 weeks treatment. No effect of EE on PPI was found after the 4 weeks treatment. 4 weeks chronic restraint stress increased PPI in mice housed in standard but not EE conditions. Stressed mice showed deficits on the 1 h delay version of the Y-maze which could be prevented by living in an enriched environment. Our results indicated that living in an enriched environment reversed the impairing effects of chronic restraint stress on spatial recognition memory. However, EE did not change the effects of stress on PPI. (C) 2010 Elsevier B.V. All rights reserved.

Extract of Ginkgo biloba leaves reverses yohimbine-induced spatial working memory deficit in rats

Extract of Ginkgo biloba is used to alleviate age-related decline in cognitive function, which may be associated with the loss of catecholamines in the prefrontal cortex. The purpose of this study was to verify whether alpha-2 adrenergic activity is involved in the facilitative effects of extract of Ginkgo biloba on prefrontal cognitive function. Male Wistar rats were trained to reach criterion in the delayed alternation task (0, 25, and 50-s delay intervals). A pilot study found that 3 or 4 mg/kg of yohimbine (intraperitoneal) reduced the choice accuracy of the delayed alternation task in a dose and delay-dependent manner, without influencing motor ability or perseverative behaviour. Acute oral pre-treatment with doses of 50, 100, or 200 mg/kg (but not 25 mg/kg) of extract of Ginkgo biloba prevented the reduction in choice accuracy induced by 4 mg/kg yohimbine. These data suggest that the prefrontal cognition-enhancing effects of extract of Ginkgo biloba are related to its actions on alpha-2-adrenoceptors.

重离子诱导人舌鳞癌细胞凋亡和Bax/Bcl-2蛋白表达的变化

In order to investigate the effect of carbon ion irradiation on apoptosis and Bax/Bcl-2 expression inhuman tongue carcinoma cells, exponentially growing human tongue carcinoma cells (Tb) cultured in vitro were irradiated with 0, 0.5, 1.0, 2.0 or 4.0 Gy of 12C6+ ions respectively. Survival rate of irradiated cells at various doses were measured by MTT assay. The nucleus changes of apoptosis and necrosis of cells stained by Hochest/PI were observed through fluorescence microscope. The cell cycle changes were detected by flow cytometry (FCM). The expressions of Bax and Bcl-2 were detected by Western blot analysis. The results show that the viability of Tb cells decreases gradually with increment of irradiation doses of carbon ions. The proportions of apoptosis cells in the irradiated groups are significantly higher than those in the control group. There is a positive correlation between irradiation doses and retardation strength in G2 /M phase at 24 h after irradiation (P<0.05). And the expressions of Bax and bcl-2 are significantly up-regulated and down-regulated respectively by 12C6+ ion irradiation. It can be concluded from above that cell apoptosis induced by heavy ion with high-LET may be mediated through the Bax/Bcl-2 expression pathway. 探讨重离子辐照对人舌鳞癌Tb细胞的凋亡及Bax/Bcl-2蛋白表达的影响。采用0、0.5、1.0、2.0、4.0 Gy重离子束辐照人舌鳞癌 Tb 细胞，应用 MTT 法检测细胞存活，流式细胞技术检测细胞周期变化，Hoechst33258/PI 复染法观察 Tb 细胞凋亡形态，并采用 Western-blot 法检测 Bax/Bcl-2 蛋白表达情况。结果发现，Tb细胞经12C6+离子束辐照后存活率显著下降，呈剂量依赖性的生长抑制；Tb细胞呈现蓝色荧光浓集成团的凋亡形态，且凋亡比例随辐照剂量增加；G2/M 期细胞百分数随照射剂量增加而增加（P＜0.05） 。Western-blot结果显示 Bax 蛋白表达水平随辐照剂量逐渐上升，但在 4 Gy 组其表达不再增高，Bcl-2 蛋白在 1.0、2.0、4.0 Gy组随剂量增大呈下降趋势。以上结果提示重离子束辐照对 Tb 细胞有抑制作用，Bax/Bcl-2 蛋白表达是重离子治癌的机制之一。

The shape parameter of Liposomes and DNA-lipid complexes determined by viscometry utilizing small sample volumes

A minicapillary viscometer utilizing <0.5 ml of sample at a volume fraction of <0.1% is described. The calculated a/b of DPPC/DPPG multilamellar liposome was 1.14 as prolate ellipsoids and a/b of dioleoylpropyltrimethyl ammonium methylsulfate-DNA complex at a charge ratio of 4: 1 (+/-) was 3.7 as prolate ellipsoids or 4.9 as oblate ellipsoids. The deviation of shape from perfect sphere is thus expressed quantitatively in more than two significant figures. In these measurement, the necessary amount of DNA is <0.5 mg.

New organic-inorganic perovskite materials with different optical properties modulated by different inorganic sheets

New organic-inorganic perovskites with different PbBr perovskite sheets stabilized by 3- or 4-an-tidinopyridine were synthesized and structurally characterized. 4-Amidinopyridine constructs < 001 >-oriented perovskite with inorganic sheets made up of typical corner-sharing octahedra of PbBr2. Analogous chemistry in the presence of 3-amidinopyridine under the same conditions results in an unusual hybrid perovskite with the inorganic sheets showing a novel framework including both corner-sharing and edge-sharing PbBr2, which is different from any previously reported ones.

Synthesis and properties of water stable poly[bis(benzimidazobenzisoquinolinone)] ionomers for proton exchange membranes fuel cells

A novel sulfonated tetraamine, di(triethylammonium)-4,4'-bis(3,4-diaminophenoxy)biphenyl-3,3'-disulfonate (BAPBDS), was successfully synthesized by nucleophilic aromatic substitution of 4,4'-dihydroxybiphenyl with 5-chloro-2-nitroaniline, followed by sulfonation and reduction. A high-temperature polycondensation of sulfonated tetraamine, non-sulfonated tetraamine (4,4 -bis(3,4-aminophenoxy)biphenyl) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (a) or 4,4'-binaphthyl-1,1',8,8'-tetracarboxylic dianydride (b) gave the poly[bis(benzimidazobenzisoquinolinones)] ionomers SPBIBI-a(x) or SPBIBI-b(x), where x refers to the molar percentage of the sulfonated tetraamine monomer. Flexible and tough membranes of high mechanical strength were obtained by solution casting and the electrolyte properties of the polymers were intensively investigated. The ionomer membranes displayed excellent dimensional and hydrolytic stabilities.

Hydrazine-based polyimides from isomeric bis(chlorophthalimide)s

3,3-Dichloro-N,N'-biphthalimide (3,3'-DCBPI), 3,4'-dichloro-N,N'-biphthalimide (3,4'-DCBPI), and 4,4'-dichloro-N,N'X-biphthalimide (4,4'-DCBPI) were synthesized from 3- or 4-chlorophthalic anhydrides and hydrazine in glacial acetic acid. The yield of 3,3'-DCBPI (90%) was much higher than that of 4,4'-DCBPI (33%) because of the better stability of the intermediate, 3-chloro-N-aminophthalimide, and 3,3'-DCBPI. A series of hydrazine-based polyimides were prepared from isomeric DCBPIs and 4,4-thiobisbenzenethiol (TBBT) in N,N-dimethylacetamide in the presence of tributylamine. Inherent viscosity of these polymers was in the range of 0.51-0.69 dL/g in 1-methyl-2-pyrrolidinone (NMP) at 30 degrees C. These polyimides were soluble in 1,1,2,2-terachloroethane, NMP, and phenols. The 5% weight-loss temperatures (T(g)s) of the polymers were near 450 degrees C in N-2. Their glass-transition temperatures (T(g)s) determined by dynamic mechanical thermal analysis and differential scanning calorimetry increased according to the order of polyimides based on 4,4'-DCBPI, 3,4'-DCBPI, and 3,3'-DCBPI. The hydrolytic stability of these polymers was measured under acid, basic, and neutral conditions and the results indicated that the order was 3,3'-DCBPI/TBBT > 3,4'-DCBPI/TBBT > 4,4'-DCBPI/TBBT.

Effect of DNA flanking sequence on charge transport in short DNA duplexes

Several factors can influence charge transport (CT)-mediated DNA, such as sequence, distance, base stacking, base pair mismatch, conformation, tether length, etc. However, the DNA context effect or how flanking sequences influence redox active drugs in the DNA CT reaction and later in DNA enzymatic repair and synthesis is still not well understood. The set of seven DNA molecules in this study have been characterized well for the study of flanking sequence effects. These DNA duplexes are formed from self-complementary strands and contain the common central four-base sequence 5'-A-G-C-T-3', flanked on both sides by either (AT)(n) or (AA)(n) (n = 2, 3, or 4) or AA(AT)(2). UV-vis, fluorescence, UV melting, circular dichroism, and cyclic voltammetry experiments were used to study the flanking sequence effect on CT-mediated DNA by using daunomycin or adriamycin cross-linked with these seven DNA molecules. Our results showed that charge transport was related to the flanking sequence, DNA melting free energy, and ionic strength. For (AA)(n) or (AT)(n) species of the same length, (AA)(n) series were more stable and more efficient CT was observed through the (AA)(n) series. The same trend was observed for (AA)(n) and (AT)(n) series at different ionic strengths, further supporting the idea that flanking sequence can result in different base stacking and modulate charge transport through these seven DNA molecules.

Synthesis and characterization of hyperbranched aromatic poly(ether imide)s

The four AB(2) monomers, N-[3- or 4-bis(4-hydroxyphenyl)toluoyl]-4-chlorophthalimide and N-{3- or 4-[1,1-bis(4-hydroxyphenyl)]ethylphenyl}-4-chlorophthalimides, were prepared and used for synthesis of hyperbranched poly(ether imide)s bearing hydroxyl end groups. These hyperbranched poly(ether imide)s had moderate molecular weights with broad distributions and showed glass-transition temperatures (Tgs) between 177 and 230 degreesC. The thermogravimetric analytic measurement revealed the decomposition temperature at 5% weight-loss temperatures (T-d(5%)) ranging from 240 to 281 degreesC. Analysis using H-1 NMR spectroscopy revealed the four types of hyperbranched poly(ether imide)s to have similar degrees of branching (ca. 60%). These polymers were modified by acylation or nucleophilic substitution reaction at the hydroxyl end groups. The conversion effectiveness depended on the type of modification reaction, modifier, and reaction conditions. The thermal stability and solubility of hyperbranched poly(ether imide)s were improved by the modification of the end groups.

Synthesis and characterization of hyperbranched aromatic poly(ester-imide)s

The synthesis and characterization of hyperbranched aromatic poly(ester-imide)s are described. A variety of AB(2) monomers, N-[3- or 4-bis(4-acetoxyphenyl)toluoyl]-4-carboxyl-phthalimide and N-{3- or 4-[1,1-bis(4-acetooxyphenyl)]ethylphenyl}-4-carboxy phthalimides were prepared starting from condensation of nitrobenzaldehydes or nitroacetophenones with phenol and used for synthesis of hyperbranched poly(ester-imide)s containing terminal acetyl groups by transesterification reaction. These hyperbranched poly(ester-imide)s were produced with weight-average molecular weight of up to 6.87 g/mol. Analysis of H-1 NMR and C-13 NMR spectroscopy revealed the structure of the four hyperbranched poly(ester-imide)s. These hyperbranched poly(ester-imide)s exhibited excellent solubility in a variety of solvents such as N,N-dimethylacetamide, dimethyl sulfoxide, and tetrahydrofuran and showed glass-transition temperatures between 217 and 255 degreesC. The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight-loss temperature (T-d(10)) ranging from 365 to 416 degreesC in nitrogen.

Polyimides derived from mellophanic dianhydride

The synthesis of mellophanic dianhydride (MPDA), an isomer of pyromellitic dianhydride (PMDA), was studied. A trend of forming cyclic oligomers in the reactions of MPDA with 4,4'-oxydianiline (ODA) or 4,4'-methylenedianiline (MDA) in DMAC was found. The cyclic dimer from MPDA/MDA was isolated and fully characterized, including an X-ray crystallographic analysis. The reactions of MPDA with aromatic diamines were found much more complicated than those of PMDA. A model study was performed to clarify the reactions. Several byproducts were isolated and characterized, so that, in an usual two-step process to prepare polyimides, imide, amide linkage, and carboxylic group may be involved in the polymer structure. The water, either existing in solvent or being generated during the imidization, is the main reason for the side reactions. The properties of some polyimides derived from MPDA and diamines were tested and compared with those of the isomeric polyimides derived from PMDA.

Polyaniline as marine antifouling and corrosion-prevention agent

Conductive polyaniline was found to have special marine antifouling property. The coating from conducting polyaniline and epoxy resin(or polyurethane) can last 6-9 months in Southern China sea, i.e., less than 10% of the coating surface was fouled during this period. The conducting polyaniline has special synergetic antifouling effect on other antifouling agents like cuprous oxide or 4, 4'-dichlorodiphenyltrichloroethane. The conductivity of the polyaniline was found to be extremely important for its antifouling effect. Moreover, employing aliphatic polyamine as solvent of emeraldine base and curing agent of epoxy resin, a new technique to process corrosion prevention coating containing emeraldine base was developed, therefrom the emeraldine base and epoxy resin was in molecular level blending. This technique was solvent free and extremely effective, i.e., only 1wt% of emeraldine base in the coating can have good corrosion prevention property.