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1.
Akitami Ichihara Koichi Moriyasu Sadao Sakamura 《Bioscience, biotechnology, and biochemistry》2013,77(12):2421-2422
Boron is an essential nutrient for plants, but it is toxic in excess. Transgenic rice plants expressing an Arabidopsis thaliana borate efflux transporter gene, AtBOR4, at a low level exhibited increased tolerance to excess boron. Those lines with high levels of expression exhibited reduced growth. These findings suggest a potential of the borate transporter BOR4 for the generation of high-boron tolerant rice. 相似文献
2.
《Inorganica chimica acta》1988,149(2):193-208
The reactions of Fe(CO)3(R-DAB; R1, H(4e)) (1a: R = i-Pr, R1 = H; 1b: R = t-Bu, R1 = H; 1c: R = c-Hex, R1 = H; 1e: R = p-Tol, R1 = H; 1f: R = i-Pr, R1 = Me) with Ru3(CO)12 and of Ru(CO)3(R-DAB; R1, H(4e)) (2a: R = i-Pr, R1 = H; 2d: R = CH(i-Pr)2, R1 = H) with Fe2(CO)9 in refluxing heptane both afforded FeRu(CO)6(R-DAB; R1, H(6e)) (3) in yields between 50 and 65%.The coordination mode of the ligand has been studied by a single crystal X-ray structure determination of FeRu(CO)6(i-Pr-DAB(6e)) (3a). Crystals of 3a are monoclinic, space group P21/a, with four molecules in a unit cell of dimensions: a = 22.436(3), b = 8.136(3), c = 10.266(1) Å and β = 99.57(1)°. The structure was refined to R = 0.049 and Rw = 0.052 using 3045 reflections above the 2.5σ(I) level. The molecule contains an FeRu bond of 2.6602(9) Å, three terminally bonded carbonyls to Fe, three terminally bonded carbonyls to Ru and bridging 6e donating i-Pr-DAB ligand. The i-Pr-DAB ligand is coordinated to Ru via N(1) and N(2) occupying an apical and equatorial site respectively (RuN(1) = 2.138(4) RuN(2) = 2.102(3) Å). The C(2)N(2) moiety of the ligand is η2-coordinated to Fe with C(2) in an apical and N(2) in an equatorial site (FeC(2) = 2.070(5) and FeN(2) = 1.942(3) Å).The 1H and 13C NMR data indicate that in all FeRu(CO)6(R-DAB(6e)) complexes (3a to 3f) exclusively η2-CN coordination to the Fe atom and not to the Ru atom is present irrespective of whether 3 was prepared by reaction of Fe(CO)3(R-DAB(4e)) (1) with Ru3(CO)12 or by reaction of Ru(CO)3(R-DAB(4e)) (2) with Fe2(CO)9. In the case of FeRu(CO)6(i-Pr-DAB; Me, H(6e)) (3f) the NMR data show that only the complex with the C(Me)N moiety of the ligand σ-N coordinated to the Ru atom and the C(H)N moiety η2-coordinated to the Fe atom was formed. Variable temperature NMR experiments up to 140 °C showed that the α-diimine ligand in 3a is stereochemically rigid bonded.FeRu(CO)6(R-DAB(6e)) (3a and 3e) reacted with allene to give FeRu(CO)5(R-DAB(4e))(C3H4) (4a and 4e). A single crystal X-ray structure determination of FeRu(CO)5(i-Pr-DAB(4e))(C3H4) (4a) was performed. Crystals of 4a are triclinic, space group P1, with two molecules in a unit cell of dimensions: a = 9.7882(7), b = 12.2609(9), c = 8.3343(7) Å, α = 99.77(1)°, β = 91.47(1)° and γ = 86.00(1)°. The structure was refined to R = 0.028 and Rw = 0.043 using 4598 reflections above the 2σ(I) level. The molecule contains an FeRu bond of 2.7405(7) Å and three terminally bonded carbonyls to iron. Two carbonyls are terminally bonded to the Ru atom together with a chelating 4e donating i-Pr-DAB ligand [RuN = 2.110(1) (mean)]. The allene ligand is coordinated in an η3-allylic fashion to the Fe atom while the central carbon of the allene moiety is σ-bonded to the Ru atom (FeC(14) = 2.166(3), FeC(15) = 1.970(2), FeC(16) = 2.127(3) and RuC(15) = 2.075(2) Å). The 1H and 13C NMR data show that in solution the coordination modes of the R-DAB and the allene ligands are the same as in the solid state.Thermolysis reactions of 3a with R-DAB or carbodiimides gave decomposition and did not afford C(imine)C(reactant) coupling products. Thermolysis reactions of 3a with M3(CO)12 (M = Ru, Os) and Me3NO gave decomposition. When the reaction of 3a with Me3NO was performed in the presence of dimethylacetylenedicarboxylate (DMADC) the known complex FeRu(CO)4(i-Pr-DAB(8e))(DMADC) (5a) was formed in low yield. In 5a the R-DAB ligand is in the 8e coordination mode with both the imine bonds η2-coordinated to iron. The acetylene ligand is coordinated in a bridging fashion, parallel with the FeRu bond. 相似文献
3.
《Inorganica chimica acta》1988,146(1):65-73
The oxovanadium(IV), acetatomanganese(III), chloroiron(III), nickel(II), copper(II), zinc(II) and palladium(II) of 3,3′-(1,2-phenylenediimino)diacrolein were prepared and investigated by means of mass, electronic, vibrational, NMR and ESR spectroscopy as well as magnetic susceptibility measurements. The acetatomanganese(III) and chloroiron(III) complexes were confirmed to be of high spin type. The absorption bands appearing in the energy range greater than 23 000 cm−1 were attributed to π→π* transitions within a ligand molecule and charge- transfer transitions from metal to ligand. The metal complexes assume the square-planar configuration type since the ligand-field bands were detected in the 12 700–18 500 cm−1 region. Strong bands appearing at 1601 and 1627 cm−1 were assigned to the CC and CO stretching vibrational modes, respectively, and were shifted to lower frequency upon metal-coordination. A VO stretching band was observed at 982 cm−1 for the oxovanadium(IV) complex and a CO stretching band was observed at 1547 cm−1 for the acetatomanganese(III) complex. Upon complex formation the amine proton signal is found to vanish and the aldehydic methine proton signal in the lowest field is shifted upfield for the nickel(II), zinc(II) and palladium(II) complexes. 13C NMR spectra support the coordination structure of the complexes which is revealed by 1H NMR spectra. As judged by the spin Hamiltonian parameters, the oxovanadium(IV) complex is of a square- planar type with an unpaired electron in the dxy orbital and the copper(II) complex assumes a distorted square-planar coordination due to the presence of five- and six-membered chelate rings with an unpaired electron in the dx2−y2 orbital. 相似文献
4.
自七十年代发现了紫杉醇(taxol)独特的抗癌机制一促进微管蛋白聚合、抑制微管蛋白解聚后,紫杉醇及其类似物紫杉烷类二该化合物的资源调查和化学研究倍受重视。紫杉醇主要存在于红豆杉科的大多数植物中,红豆杉科(Taxaceae)红豆杉属(TaxuS)植物全球大约有11种,我国有4种和1个变种。我们从采自湖北神农架的红豆杉(Tchinens周树皮中分离得到8个结晶性物质,本文报道其中已鉴定的3个成分,即taxinineJ(l),ldiydroxybaccatinl(2)和taxol(3)。据文献报道,已经从红豆杉分离得到二十多种紫杉烷类化合物l'l,而我们分离得到的1和2… 相似文献
5.
第三节祖国在防治疾病上的伟大成就这节课是在学生已掌握了传染病的基本知識的基础上来进行講授的,首先在教材里提出以血吸虫病、天花、瘧疾、黑热病、痳疯等传染病說明了新旧社会的对比;同时也说明了社会主义社会制度的优越性。我們的党和政府对于人民健康的关怀是无微不至的,并且对于各种疾病的积极防治工作加强了党的领导,及时提出了一系列的方針、政策和措施;建立了专业防治机构,培养了专业干部;結合生产发动了广大羣众来参加防治。因此在防治各种传染病的工作中取得了很大的成績。 相似文献
6.
第五节大脑皮层的机能——高级神經活动本节是本章也是本書的高峯,是把过去学习过有关反射作用的知識进行总結和提高,使学生能从理論上理解神经对人的意义——保持內部各器官的协調,同外界环境的统一。 相似文献
7.
The chief motive behind this research is the interest provoked by the presence of metal ions as necessary stabilizers of the negative charges of phosphate groups in nucleic acids. The effect that the presence of different metal ions produces on the band principally assigned to the nu(s) PO(3)(2-) mode has been studied using FT-IR and FT-Raman spectroscopy. The results obtained reveal the diagnostic capacity of these techniques in determining the type of metal ion interaction with respect to the mononucleotides that form DNA and RNA, providing a tool for improving the knowledge of the stabilizing or destabilizing effects of these ions on such macromolecules. The metal complexes of the ribonucleotides 5'-CMP and 5'-GMP with Mg(II), Ca(II), Sr(II), Ba(II), Cr(III), Co(II), Cu(II), Zn(II), Cd(II), Al(III) and Ga(III) were obtained in this study. After studying and analyzing the IR and Raman spectra of all these complexes and comparing them with the spectra of the corresponding disodium salts, it was verified that, independently of the type of nucleotide involved, the presence of the metal in the vicinity of the phosphate group produces an alteration in the aforementioned nu(s) PO(3)(2-) band. This effect is related to the type of interaction that the phosphate group has with the metal. Three components are observed: (1) one near 983-975 cm(-1) (detectable in IR and Raman), associated with phosphate groups in an electrostatic type of interaction with the metal ion, separated by two or more water molecules; (2) another near 989-985 cm(-1) (only in IR), associated with phosphate groups in indirect interaction through the water molecules of the coordination sphere of the metal ions; and (3) the IR and Raman bands near 1014-1001 cm(-1), which represent phosphate groups directly bonded to the metal ion. These results are supported by the behavior of 5'-CMP in aqueous solution in the presence of Mg(II) ions. 相似文献
8.
Hall(1977)首次在新西兰的土壤中发现GlomusinjtequensHall。Ames和Schneider(979)在美国的加利福尼亚再次发现了这个种。他们认为该种与无梗囊霉(Acauloryora)有相似之处,抱子都是从泡囊发育而成,但无梗囊霉的抱于是在产抱囊的侧面形成,而该种的抱子则是在产抱囊柄的内部发育而成的。为此,Ames和Schneider(197)为这个种建立起一个新属——内养囊霉属(Entrophospora),把这个种改名为稀有内养囊霉Entrophoworam斤equens(HallAmesetSchnelder。SChellGk和Spain(1984)报道了这个属的另一个种哥伦比亚内养囊霉(Entro… 相似文献
9.
Apanteles Pieridis (bouché) (Hym., Braconidae), ein Parasit vonAporia Crataegi (L.) (Lep., Pieridae)
Hubert Wilbert 《BioControl》1960,5(3):183-211
Ohne Zusammenfassung 相似文献
10.
Rengaswami Chandrasekaran Andrea Giacometti Struther Arnott 《Journal of biomolecular structure & dynamics》2013,31(6):1011-1022
Abstract The molecular structure of poly (dT)·poly (dA)·poly (dT) has been determined and refined using the continuous x-ray intensity data on layer lines in the diffraction pattern obtained from an oriented fiber of the DNA. The final R-value for the preferred structure is 0.29 significantly lower than that for plausible alternatives. The molecule forms a 12-fold right- handed triple-helix of pitch 38.4 Å and each base triplet is stabilized by a set of four Crick-Watson-Hoogsteen hydrogen bonds. The deoxyribose rings in all the three strands have C2′-endo conformations. The grooveless cylindrical shape of the triple-helix is consistent with the lack of lateral organization in the fiber. 相似文献
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Jan M. Anderson 《Photosynthesis research》1991,30(1):1-5
Obituary
Robert (Robin) Hill (1899–1991) 相似文献13.
TheZhoukoudian(Choukoutien)Site(英汉对照)TheZhoukoudianSite,famous“home”ofPekingMan,liesapproximately50kilometressouthwestofthePe... 相似文献
14.
粘虫(Pseudaletia separata(Walker))生殖系统的解剖 总被引:2,自引:0,他引:2
本文内容是研究粘虫(Pseudaletia separata(Walker)生殖系统的形态构造。全文分为雄性内部生殖器、雄性外部生殖器、雌性内部生殖器及雌性外部生殖器四部分。 粘虫的雄性内生殖器中, 有睾丸一对, 左右并列, 呈扁椭圆形, 外被紫红色睾丸膜; 输精管一对, 基部膨大成二对贮精囊; 射精管分成复射精管及单射精管两部分。雄性外生殖器的构造极为复杂, 第9腹节的背、腹板分别形成马鞍状的背兜及基腹弧; 第10腹节仅有其附肢特化成钩形突、颚形突和背兜侧突等; 抱握器占雄性外生殖器中的大部分, 其顶上角具长约1毫米的端刺一枚, 此为本种特征之一, 可以此与近似种区别; 阳茎由基部球状的阳茎囊和端部柄状的阳茎端组成, 内具内阳茎及角状器:雄性外生殖器中有关器官的肌肉来源亦作了叙述。 精液是以贮存于精球的方式授入雌体, 精球分为精球体、精球柄及系带三部分。 雌性内生殖器中, 卵巢为多滋式, 一对, 各由四个卵巢管组成, 两组卵巢管再与一对侧输卵管相连, 后者通入中输卵管中, 中输卵管后端连有外生殖腔, 其外方的开口是为产卵孔; 受精囊为长形梨状物, 分成主囊及副囊两部分, 两者在顶部愈合, 并由此发出受精管与外生殖腔相通, 在主囊顶端有受精囊腺; 附腺一对, 与附腺囊相连, 后者通入附腺主囊, 并由此开口入外生殖腔。雌性外生殖器是由交配囊和产卵器组成, 前者复可分成囊导管、囊体及囊颈三部分, 其外方的开口为交配囊孔, 有导精管从囊颈连于外生殖腔; 产卵器由第8、9腹节组成, 非呈特殊构造。 相似文献
15.
X-ray diffraction analyses of fibers of polydeoxyadenylic acid · polydeoxythymidylic acid show that this molecule exists as a 10-fold double-helix with axial rise per nucleotide . The structure is very similar to B-DNA () in having C3-exo furanose rings and base-pairs positioned centrally on the helix axis, but distinctive enough to have two packing modes, neither of which has been observed for B-DNA. Although the triple-stranded poly(dT) · poly(dA) · poly(dT) also has a large value of h(3.26 Å), each of the chains is a 12-fold helix of the A-genus with C3-endo furanose rings and bases displaced several Angstrom units from the helix axis. 相似文献
16.
John M. Pope Philip R. Stevens Michael T. Angotti Robert Nakon 《Analytical biochemistry》1980,103(1):214-221
Potentiometric, visible, and infrared studies of the complexation of N-(2-acetamido)-2-aminoethanesulfonic acid (ACESH) by Ca(II), Mg(II), Mn(II), Co(II), Zn(II), Ni(II), and Cu(II) are reported. Ca(II), Mg(II), and Mn(II) were found not to complex with ACES?, while Co(II), Zn(II), Ni(II), and Cu(II) were found to form 2:1, ACES? to M2+, complexes, and [Cu(ACES)2] was found to undergo stepwise deprotonation of the amide groups to form [Cu(H?1ACES)22?]. Formation (affinity) constants for the various metal complexes are reported, and the probable structures of the various metal chelates in solution are discussed. 相似文献
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18.
(S)-(?)-Vertinolide 1 was synthesized via the tetronic acid derivative 6 from (S)-(?)-tetrahydro-2-methyl-5-oxo-2-furancarboxylic acid 3. (±)-Vertinolide was also synthesized from (±)-3. 相似文献
19.
3 临床治疗 3.1 临床肿瘤学拨款临床肿瘤学规划提供的拨款,支持研究治疗人类癌症中抗癌剂的应用及其效果的评估。它包括四个特殊领域:化疗药物的毒性和效果,单独激素治疗或同其它治疗方式相结合的临床研究;用动物模型和细胞系统发展治疗研究;对可能干扰抗癌药物活性,与癌有关的失调进行研究;进行癌症临床试验新方法的研究。该规划拨款还对癌症治疗时引起癌症患者承担的潜伏生命威胁处境给予支持。出血控制时的血小板转输,白血球输送, 相似文献
20.
D. Hennig E. B. Starikov J. F. R. Archilla F. Palmero 《Journal of biological physics》2004,30(3):227-238
We investigate the charge transport in synthetic DNA polymers built up from single type of base pairs. In the context of a polaronlike model, for which an electronic tight-binding system and bond vibrations of the double helix are coupled, we present estimates for the electron-vibration coupling strengths utilizing a quantum-chemical procedure. Subsequent studies concerning the mobility of polaron solutions, representing the state of a localized charge in unison with its associated helix deformation, show that the system for poly(dG)–poly(dC) and poly(dA)–poly(dT) DNA polymers, respectively possess quantitatively distinct transport properties. While the former supports unidirectionally moving electron breathers attributed to highly efficient long-range conductivity, the breather mobility in the latter case is comparatively restrained, inhibiting charge transport. Our results are in agreement with recent experimental results demonstrating that poly(dG)–poly(dC) DNA molecules acts as a semiconducting nanowire and exhibit better conductance than poly(dA)–poly(dT) ones. 相似文献