964 resultados para 1,3,5-Triazine


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报导了标题化合物C_(10)H_(14)OS_2(M_r=214.35)的晶体结构,该晶体属正交晶系,空间群为P2_12_12_1,晶胞参数为a=6.443(3),b=8.980(4),c=18.213(7);V=1053.8(6)3;Z=4,D_x=1.35g/cm~3,F(000)=455,μ=4.5cm~(-1)(MoKa)。最终偏离因子R=0.033,R_w=0.034。分子中的两支C_(sp)2-S键键长近于相等,分别为1.761(3)和1.769(3),C(1)-C(5)键长为1.361(4)。

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在温和条件下能快速切断核酸的人工酶有许多重要的潜在应用价值,如作为模拟的限制性内切酶并发展到新的抗癌药物,因此,长期以来人们致力于研究具有高效率及高选择性的人工酶.关于稀土对核酸断裂作用的研究尚不多,而稀土对环核苷酸的催化水解作用只有Sumaoka等曾报道Ce~(3+)对3’,5’-环腺嘌呤单核苷酸(cAMP)有快速的水解作用,稀土对不同环核苷酸的催化水解作用尚未见报道.3’,5’-环腺嘌呤单核苷酸与3’,5’-环鸟嘌呤单核苷酸(cGMP)具有调节细胞应答及细胞间信息传递的作用,且细胞内不同环核苷酸的变化与某些心血管疾病的发病机理有关.本文用高压液相色谱(HPLC)和核磁共振(NMR)研究了稀土对cAMP与cGMP的断裂作用,并深入探索了其机理,这对于寻找高效率及高选择性的核酸催化体系,阐明稀土在生物体内的作用具有重要的意义.

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本文报道9种新的含磷杂环化合物的电子轰击质谱(EIMS),并应用B/E、B2/E联动扫描及精确质量测量技术,探讨了该类化合物的质谱断裂机理,发现骨架重排及开环反应是该类化合物主要的质谱特征,而R2基因对重排过程有很大影响。

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对钴与4-[(5-氯-2-吡啶)偶氮]-1,3-二氨基苯(5-Cl-PADAB)形成络合物的吸收光谱进行探讨,结果表明:试剂及络合物在不同酸度条件下形成不同型体。在酸性条件下,络合物为大阳离子,钴离子以三价形式存在,钻与试剂的络合比为1:2。在强酸性介质中,将此络合物用于光度测定钻,方法选择性及稳定性好,且灵敏度极高。对水、粮食、土壤、茶叶及维生素B_(12)中微量钻进行直接测定,获得满意结果。

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提出了由β,β-1,3-亚丙二硫基-α,β-不饱和芳酮类化合物(1)与苄基氯化镁及烯丙基溴化镁加成所得的醇(2)在BF_3·Et_2O催化下脱水生成共轭烯烃(3)新的合成途径,合成了13种新化合物,结构经~1H N-MR、IR、UV及元素分析等确证.并对这一新合成途径的反应机制进行了讨论.

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[CoCl4(C3H12N2)], M(r) = 276.87, monoclinic, P2(1)/n, a = 10.703 (2), b = 10.653 (1), c = 10.852 (2) angstrom, beta = 118.46 (1)-degrees, V = 1087.8 angstrom 3, Z = 4, D(x) = 1.69 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 22.60 cm-1, F(000) = 556, T = 298 K, final R = 0.059 for 1068 unique reflections [I > 3-sigma(I)]. The Co(II) ion is coordinated by four Cl atoms in a tetrahedral geometry. The paraffinic chains which bridge the tetrahedra have a nearly planar zigzag configuration.

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本文报道15种新合成的2-硫-1,3,2-氧氮磷杂环戊烷衍生物的 EI 谱.在质量分析离子动能谱、碰撞诱导分解谱、B/E 联动扫描及高分辨精确质量测量的基础上,讨论了这类化合物的质谱裂解机理及特征.着重讨论上述化合物的氧硫异构现象及几种重排反应.

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Zhikong scallop Chlamys farreri(Jones et Preston) is an economically important species in China. Understanding its immune system would be of great help in controlling diseases. In the present study, an important immunity-related gene, the Lipopolysaccharide and Beta-1,3-glucan Binding Protein (LGBP) gene, was located on C. farreri chromosomes by mapping several lgbp-containing BAC clones through fluorescence in situ hybridization (FISH). Through the localization of various BAC clones, it was shown that only one locus of this gene existed in the genome of C. farreri, and that this was located on the long arm of a pair of homologous chromosomes. Molecular markers, consisting of eight single nucleotide polymorphism (SNPs) markers and one insertion-deletion (indel), were developed from the LGBP gene. Indel marker testing in an F1 family revealed slightly distorted segregation (p = 0.0472). These markers can be used to map the LGBP gene to the linkage map and assign the linkage group to the corresponding chromosome. Segregation distortion of the indel marker indicated genes with deleterious alleles might exist in the surrounding region of the LGBP gene.

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A pattern recognition protein (PRP), lipopolysaccharide and beta-1,3-glucan binding protein (LGBP) cDNA was cloned from the haemocyte of Chinese shrimp Fenneropenaeus chinensis by the techniques of homology cloning and RACE. Analysis of nucleotide sequence revealed that the full-length cDNA of 1,275 bp has an open reading frame of 1,098 bp encoding a protein of 366 amino acids including a 17 amino acid signal peptide. Sequence comparison of the deduced amino acid sequence of F. chinensis LGBP showed a high identity of 94%, 90%, 87%, 72% and 63% with Penaeus monodon BGBP, Litopenaeus stylirostris LGBP, Marsupenaeu japonicus BGBP, Homarus gammarus BGBP and Pacifastacus leniusculus LGBP, respectively. The calculated molecular mass of the mature protein is 39,857 Da with a deduced pI of 4.39. Two putative integrin binding motifs, RGD (Arg-Gly-Asp) and a potential recognition motif for beta-1,3-linkage of polysaccharides were observed in LGBP sequence. RT-PCR analysis showed that LGBP gene expresses in haemocyte and hepatopancreas only, but not in other tissues. Capillary electrophoresis RT-PCR method was used to quantify the variation of mRNA transcription level during artificial infection with heat-killed Vibrio anguillarum and Staphylococcus aureusin. A significant enhancement of LGBP transcription was appeared at 6 h post-injection in response to bacterial infection. These results have provided useful information to understand the function of LGBP in shrimp.

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The electrochemical impedance spectroscopy (EIS) at different potentials has been used to study the oxygen reduction reaction (ORR) in 3.5% NaCl solution on glassy carbon (GC) electrode in this work. Results show that ORR consists of three two-electron reaction steps and both superoxide ion (O-2(-)) and hydrogen peroxide (H2O2), which are produced by ORR, obstruct the diffusion of oxygen to the surface of the electrode and make the EIS results change into a transmissive finite diffusion process with the real part contraction and a reflective finite diffusion process from a semi-infinite diffusion process. The values of electron transfer resistance (R-t) and diffusion resistance (R-d) were calculated from EIS. O-2(-) influenced strongly on the Rt values and induced a maximum at -0.45 V.

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The title compound, ( C19H15N4)(2)[ CdCl4], a salt comprising two 2,3,5-triphenyl-substituted tetrazolium cations and a tetrachloridocadmate(II) anion, was synthesized by hydrothermal methods. In the anion, the Cd-II ion is tetrahedrally coordinated by four chloride anions. In the crystal structure, four cations and two anions pack into inversion-related subunits linked by C-H center dot center dot center dot Cl and offset pi-stacking interactions.Each of these subunits is surrounded by six others. Intermolecular pi-pi stacking interactions between phenyl rings are observed along the a axis, with perpendicular distances between the ring planes of 3.6015 and 3.6934 angstrom.

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The influence of air and soil warming on root vole (Microtus oeconomus L.) population was studied in winter period in top open chambers (OTC) (0.8-1.8 m(2) warmed by conical fiberglass material and situated in alpine meadow (3250 m) at Qinghai-Tibet Plateau, China. The OTCs were distributed on an area of 30 x 30 m of experimental warming site; another site of the same area was a control one. The root vole population was investigated on two pairs of sites in "low-grazing" and "high-grazing" (by sheep) parts of the meadow; mark-recapture method was used. The winter-season averaged air and soil temperature inside of the chambers were 1.3 degrees C higher than the temperature outside the chambers. The warming in the chambers had no statistically significant effect on root vole numbers, on average body mass of individual, and on average body mass of males and females. In conclusion, as small as 1.3 degrees C warming of soil and air introduced locally and on small (several m(2)) scale, in the alpine meadow habitat in winter period, has possibly no effect on root vole numbers and biomass.