328,660 research outputs found
Pyrrolylaldiminato complexes of Zn, Mg and Al
No full textThe reaction of 2-(2,6-iPr(2)C(6)H(3)N = CH)-5-R-C4H2NH (R = H, (LH)-H-1; R = tBu, (LH)-H-2) with one equivalent of ZnMe2 or MgnBu(2) in toluene or n-hexane afforded the bis(pyrrolylaldiminato) complexes ZnL21 (1), ZnL22 (2) and MgL22 (3). Crystalline 2 2 MgL21.THF (4THF) was formed by treatment of LiL1 with MeMgCl in THF followed by recrystallization from n-hexane. (LAlMe2)-Al-1 (6) and (LAlMe2)-Al-2 (7) were readily prepared by refluxing (LH)-H-1 and (LH)-H-2 with AlMe3 in toluene or n-hexane for several hours, However, the reaction of LiL1 with AlCl3 in a 1:1 molar ratio provided (L2AlCl)-Al-1 (8), while the reaction of KL2 with AlCl3 afforded (LAlCl2)-Al-2 (9). Compounds 2, 3, 5, and 8 were characterized by a single-crystal X-ray structural analysis. Compounds 2, 3, and 5 all have a tetrahedral geometry around the metal atom, while the five-coordinate aluminum in 8 has a trigonal bipyramidal geometry
Pyrrolylaldiminato complexes of Zn, Mg and Al
No full textThe reaction of 2-(2,6-iPr(2)C(6)H(3)N = CH)-5-R-C4H2NH (R = H, (LH)-H-1; R = tBu, (LH)-H-2) with one equivalent of ZnMe2 or MgnBu(2) in toluene or n-hexane afforded the bis(pyrrolylaldiminato) complexes ZnL21 (1), ZnL22 (2) and MgL22 (3). Crystalline 2 2 MgL21.THF (4THF) was formed by treatment of LiL1 with MeMgCl in THF followed by recrystallization from n-hexane. (LAlMe2)-Al-1 (6) and (LAlMe2)-Al-2 (7) were readily prepared by refluxing (LH)-H-1 and (LH)-H-2 with AlMe3 in toluene or n-hexane for several hours, However, the reaction of LiL1 with AlCl3 in a 1:1 molar ratio provided (L2AlCl)-Al-1 (8), while the reaction of KL2 with AlCl3 afforded (LAlCl2)-Al-2 (9). Compounds 2, 3, 5, and 8 were characterized by a single-crystal X-ray structural analysis. Compounds 2, 3, and 5 all have a tetrahedral geometry around the metal atom, while the five-coordinate aluminum in 8 has a trigonal bipyramidal geometry
Review of the book Unbegrenzte moglichkeiten: Amerikanisierung in Deutschland und Frankreich (1900-1933) by Egbert Klautke
No full textDr. Jeff R. Schutts (Douglas College) reviews the book Unbegrenzte Moglichkeiten: Amerikanisierung in Deutschland und Frankreich (1900-1933) by Egbert Klautke (2005).Final article published
DETERMINATION OF H(N),H-ALPHA AND H(N), C' COUPLING-CONSTANTS IN C-13,N-15-LABELED PROTEINS
No full textSensitive three-dimensional NMR experiments, based on the E.COSY principle, are presented for the measurement of the 3J(H(N),H(alpha) and 3J(H(N),C') coupling constants in uniformly C-13- and N-15-labeled proteins. They employ gradient coherence selection in combination with the sensitivity enhancement method in HSQC-type spectra (Cavanagh et al., 1991; Palmer et al., 1991). In most cases, the two measured coupling constants unambiguously define the phi-angle for protein structure determination. The method is applied to uniformly C-13,N-15-labeled ribonuclease T1
DETERMINATION OF H(N),H-ALPHA AND H(N), C' COUPLING-CONSTANTS IN C-13,N-15-LABELED PROTEINS
No full textSensitive three-dimensional NMR experiments, based on the E.COSY principle, are presented for the measurement of the 3J(H(N),H(alpha) and 3J(H(N),C') coupling constants in uniformly C-13- and N-15-labeled proteins. They employ gradient coherence selection in combination with the sensitivity enhancement method in HSQC-type spectra (Cavanagh et al., 1991; Palmer et al., 1991). In most cases, the two measured coupling constants unambiguously define the phi-angle for protein structure determination. The method is applied to uniformly C-13,N-15-labeled ribonuclease T1
Sucrose- and H+-dependent charge movements associated with the gating of sucrose transporter ZmSUT1
No full textBackground: In contrast to man the majority of higher plants use sucrose as mobile carbohydrate. Accordingly proton-driven sucrose transporters are crucial for cell-to-cell and long-distance distribution within the plant body. Generally very negative plant membrane potentials and the ability to accumulate sucrose quantities of more than 1 M document that plants must have evolved transporters with unique structural and functional features.
Methodology/Principal Findings: To unravel the functional properties of one specific high capacity plasma membrane sucrose transporter in detail, we expressed the sucrose/H+ co-transporter from maize ZmSUT1 in Xenopus oocytes. Application of sucrose in an acidic pH environment elicited inward proton currents. Interestingly the sucrose-dependent H+ transport was associated with a decrease in membrane capacitance (Cm). In addition to sucrose Cm was modulated by the membrane potential and external protons. In order to explore the molecular mechanism underlying these Cm changes, presteady-state currents (Ipre) of ZmSUT1 transport were analyzed. Decay of Ipre could be best fitted by double exponentials. When plotted against the voltage the charge Q, associated to Ipre, was dependent on sucrose and protons. The mathematical derivative of the charge Q versus voltage was well in line with the observed Cm changes. Based on these parameters a turnover rate of 500 molecules sucrose/s was calculated. In contrast to gating currents of voltage dependent-potassium channels the analysis of ZmSUT1-derived presteady-state currents in the absence of sucrose (I = Q/τ) was sufficient to predict ZmSUT1 transport-associated currents.
Conclusions: Taken together our results indicate that in the absence of sucrose, ‘trapped’ protons move back and forth between an outer and an inner site within the transmembrane domains of ZmSUT1. This movement of protons in the electric field of the membrane gives rise to the presteady-state currents and in turn to Cm changes. Upon application of external sucrose, protons can pass the membrane turning presteady-state into transport currents
Simultaneous Cassini VIMS and UVIS observations of Saturn's southern aurora: Comparing emissions from H, H-2 and H-3(+) at a high spatial resolution
No full textHere, for the first time, temporally coincident and spatially overlapping Cassini VIMS and UVIS observations of Saturn's southern aurora are presented. Ultraviolet auroral H and H-2 emissions from UVIS are compared to infrared H-3(+) emission from VIMS. The auroral emission is structured into three arcs - H, H-2 and H-3(+) are morphologically identical in the bright main auroral oval (similar to 73 degrees S), but there is an equatorward arc that is seen predominantly in H (similar to 70 degrees S), and a poleward arc (similar to 74 degrees S) that is seen mainly in H-2 and H-3(+). These observations indicate that, for the main auroral oval, UV emission is a good proxy for the infrared H-3(+) morphology (and vice versa), but for emission either poleward or equatorward this is no longer true. Hence, simultaneous UV/IR observations are crucial for completing the picture of how the atmosphere interacts with the magnetosphere
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Measurements of R(d) - R(p) and R(Ca) - R(C) in deep inelastic muon scattering
No full textAmaudruz P, Arneodo M, Arvidson A, et al. Measurements of R(d) - R(p) and R(Ca) - R(C) in deep inelastic muon scattering. Phys.Lett. B. 1992;294(1):120-126
Papers of R H Horne
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/69212R.H. "Orion" Horne: Syllabus of Three Lectures on the Undeveloped Characters in Shakespeare's Plays by R.H. Horne, author of "Orion", "Cosmo de Medici" and "Death of Marlowe", etc. Leaflet showing contents of each of the three lectures. On verso, a note by Horne explaining that these lectures had been given at the Manchester Athenuem, the Literary and Scientific Institute, Marylebone, and at the Mechanics Institute, Liverpool. This leaflet is folded in with handwritten expositions (probably lectures): 1. The Bible, 31 pp. 2. Gems form Auriel (Henri Frederico Auriel, 1821-1881), 5 pp. 3. Some illustrations of Shakespeare's Art, 20 pp.113896
Acquisition: [1989.0151] "Papers of R H Horne
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