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991.
Abstract— Slow destruction of the far-red-absorbing form of phytochrome (Pfr ), which has been observed in light-grown oat and maize, occurs in light- and dark-grown Amaranthus, Pharbitis , and Brassica seedlings as well. Destruction of Pfr in these seedlings shows two phases: if a high level of Pfr is produced in dark-grown seedlings, the destruction is fast in the beginning and then slows after a low Pfr level has been reached. Slow Pfr destruction is predominant in light-grown tissue. 相似文献
992.
W. Trombik W. Dünnweber W. Trautmann W. Dahme K. A. Eberhard W. Hering D. Konnerth R. Singh 《Zeitschrift für Physik A Hadrons and Nuclei》1980,296(2):187-188
The spin alignment Pzz of12C(2 1 + ) produced in12C+12C inelastic scattering at bombarding energies in the region of known resonances between Ecm=18.5 and 32.8 MeV has been determined with a γ-ray detector positioned in the direction of the scattering normal. The values obtained in the centers of three resonances as well as those obtained off-resonance are spread over a range between ?.05 and +.80 with no clear indication in favour of simple pictures of molecular resonances. 相似文献
993.
tBu2P–PLi–PtBu2·2THF reacts with [cis‐(Et3P)2MCl2] (M = Ni, Pd) yielding [(1,2‐η‐tBu2P=P–PtBu2)Ni(PEt3)Cl] and [(1,2‐η‐tBu2P=P–PtBu2)Pd(PEt3)Cl], respectively. tBu2P– PLi–PtBu2 undergoes an oxidation process and the tBu2P–P–PtBu2 ligand adopts in the products the structure of a side‐on bonded 1,1‐di‐tert‐butyl‐2‐(di‐tert‐butylphosphino)diphosphenium cation with a short P–P bond. Surprisingly, the reaction of tBu2P–PLi–PtBu2·2THF with [cis‐(Et3P)2PtCl2] does not yield [(1,2‐η‐tBu2P=P–PtBu2)Pt(PEt3)Cl]. 相似文献
994.
Lucien Eberhard Jean-Pierre Lampin Francois Mathey 《Journal of organometallic chemistry》1974,80(1):109-118
The reaction of n-BuLi with phenyldiferrocenylphosphine oxide yields a mixture of two isomeric dianions. This mixture reacts with Me3SiCl, Br2, CO2, PhCHO and PhCHNPh to give bifunctional products. With CoCl2, Me2SiCl2, Ph2SiCl2, Bu2SnCl2 and PhCOOEt, the same mixture gives cyclic products. In almost every case each of these compounds is a mixture of two isomers corresponding to the original compound. The characteristic patterns of the PMR spectra are in full agreement with the structures proposed for the isomeric dianions. 相似文献
995.
ANALYSIS OF THE BINDING OF PHYTOCHROME TO PARTICULATE FRACTIONS 总被引:2,自引:0,他引:2
Abstract— The binding of phytochrome to receptor sites in a particulate fraction of maize coleoptiles has been studied as a function of the level of far-red-absorbing phytochrome (Pfr ) offered in vivo and in vitro. Evidence is presented that the binding is cooperative. The degree of cooperativity expressed by the Hill coefficient of the binding function is the same (1–6) both in vivo and in vitro , whereas the Hill coefficient of the state function in vivo is significantly higher (2-1). The highest Hill coefficient (3–5) was found for the in vitro binding function in squash hooks. 相似文献
996.
Klemm C Schröder S Glückmann M Beyermann M Krause E 《Rapid communications in mass spectrometry : RCM》2004,18(22):2697-2705
The identification of phosphorylation sites is essential for a full understanding of the cellular functions of proteins. However, mass spectrometric analysis is often hampered by the low abundance of phosphoproteins, the difficulty of obtaining full sequence coverage by specific proteolysis reactions, and the low ionization efficiency of phosphopeptides compared with their non-phosphorylated analogs. In the present work a beta-elimination/Michael addition was used to replace the phosphate groups of pSer or pThr by a group which gives rise to an enhanced ionization efficiency. In order to find optimum reaction conditions, beta-elimination/Michael addition was examined using phosphorylated model peptides. Whereas complete elimination of phosphate could be achieved by treatment with barium hydroxide in organic solvents such as ethanol or acetonitrile, the yield of the Michael adduct strongly depended on the nucleophile and the peptide sequence. Reaction with 2-phenylethanethiol, p-bromophenethylamine and ethylenediamine clearly resulted in products showing higher matrix-assisted laser desorption/ionization (MALDI) signal intensities compared with those of the corresponding phosphorylated precursors. The method was successfully used to identify phosphorylated sequences of ovalbumin and human Stat1 by in-gel derivatization with 2-phenylethanethiol and subsequent peptide mass fingerprint analysis of the trypsin digests. 相似文献
997.
The reaction of the ligand 2-(2-trifluoromethyl)anilino-4,6-di-tert-butylphenol, H(2)((1)L(IP)), and PdCl(2) (2:1) in the presence of air and excess NEt(3) in CH(2)Cl(2) produced blue-green crystals of diamagnetic [Pd(II)((1)L(ISQ))(2)] (1), where ((1)L(ISQ))(*)(-) represents the o-iminobenzosemiquinonate(1-) pi radical anion of the aromatic ((1)L(IP))(2-) dianion. The diamagnetic complex 1 was chemically oxidized with 1 equiv of Ag(BF(4)), affording red-brown crystals of paramagnetic (S = (1)/(2)) [Pd(II)((1)L(ISQ))((1)L(IBQ))](BF(4)) (2), and one-electron reduction with cobaltocene yielded paramagnetic (S = (1)/(2)) green crystals of [Cp(2)Co][Pd(II)((1)L(ISQ))((1)L(IP))] (3); ((1)L(IBQ))(0) represents the neutral, diamagnetic quinone form. Complex 1 was oxidized with 2 equiv of [NO]BF(4), affording green crystals of diamagnetic [Pd(II)((1)L(IBQ))(2)](3)(BF(4))(4){(BF(4))(2)H}(2).4CH(2)Cl(2) (5). Oxidation of [Ni(II)((1)L(ISQ))(2)] (S = 0) in CH(2)Cl(2) solution with 2 equiv of Ag(ClO(4)) generated crystals of [Ni(II)((1)L(IBQ))(2)(ClO(4))(2)].2CH(2)Cl(2) (6) with an S = 1 ground state. Complexes 1-5 constitute a five-membered complete electron-transfer series, [Pd((1)L)(2)](n) (n = 2-, 1-, 0, 1+, 2+), where only species 4, namely, diamagnetic [Pd(II)((1)L(IP))(2)](2-), has not been isolated; they are interrelated by four reversible one-electron-transfer waves in the cyclic voltammogram. Complexes 1, 2, 3, 5, and 6 have been characterized by X-ray crystallography at 100 K, which establishes that the redox processes are ligand centered. Species 2 and 3 exhibit ligand mixed valency: [Pd(II)((1)L(ISQ))((1)L(IBQ))](+) has localized ((1)L(IBQ))(0) and ((1)L(ISQ))(*)(-) ligands in the solid state, whereas in [Pd(II)((1)L(ISQ))((1)L(IP))](-) the excess electron is delocalized over both ligands in the solid-state structure of 3. Electronic and electron spin resonance spectra are reported, and the electronic structures of all members of this electron-transfer series are established. 相似文献
998.
Abstract— Photogeotropic equilibrium angles were measured for Phycomyces blakesleeanus wild type firstly by means of dichromatic fluence rate response curves using simultaneous irradiation with near threshold 450 nm reference light (constant at 1.2 × 10?8 W m?2) and variable fluence rates of test light (498–630 nm) from the same side. These curves showed minima for test light fluence rates that were close to the photogeotropic threshold for these wavelengths. Secondly, the time course of this inhibitory effect was studied with both the inductive reference 450 nm light (2 × 10?-7 W m?2) and the test light (606 or 450 nm) given as light pulses of 2 s duration (2 s light/48 s dark periods for 6 h). The dark period between the onset of the inductive reference light and test light pulses was varied between 0 and 48 s. No inhibitory effects were observed for simultaneous pulses; however, inhibitory effects were demonstrated for delay times of 2 s and 20 s for 606 nm as well as 450 nm test light. If the test light pulses were given immediately before the inductive reference light, only 606 nm test light was effective in producing a significant inhibitory effect. The results are discussed with regard to a multichromophoric photoreceptor system and to the wavelength dependence of the effects observed. The data and conclusions favor a photoreceptor system with at least two separate chromophoric absorptions of the blue light receptor type, one acting positively, the other acting inhibitorily, and at least one other photoreceptor of presumably minor influence. 相似文献
999.
Prof. Dr. Eberhard Kaniuth 《Monatshefte für Mathematik》1982,93(4):293-302
LetG be a -compact locally compact group such thatG/Z(G), whereZ(G) denotes the center ofG, has a relatively compact commutator subgroup. It is shown that primary ideals inL
1(G) are maximal. 相似文献
1000.
Eberhard M. Schröder 《Journal of Geometry》1982,18(1):57-69
If V is a vector space over a commutative field K, and if QV K is an arbitrary quadratic form 0, then the metric vector space (V,K,Q) determines a projective metric space ((V,K),Q), consisting of the projective space (V,K) and a congruence relation Q induced by Q, By generalizing results of F.Bachmann, H.Karzel, R.Lingenberg, W.Nolte and U.Ott, in this paper we present a complete solution for the problem of finding a common intrinsic characterization of all projective metric spaces. The solution is based on a sharp three-reflection-theorem, which can be formulated algebraically in the Clifford algebra C(Q) of (V,K,Q), even if this algebra is commutative.
Rafael Artzy zum 70. Geburtstag gewidmet 相似文献
Rafael Artzy zum 70. Geburtstag gewidmet 相似文献