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111.
F.J. Hartmann 《Hyperfine Interactions》1999,119(1-4):175-184
The experiments on metastable antiprotonic helium atoms are reviewed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
112.
Non-contact protein microarray fabrication using a procedure based on liquid bridge formation 总被引:1,自引:1,他引:0
Michael Hartmann Johan Sjödahl Mårten Stjernström Johan Redeby Thomas Joos Johan Roeraade 《Analytical and bioanalytical chemistry》2009,393(2):591-598
Contemporary microarrayers of contact or non-contact format used in protein microarray fabrication still suffer from a number
of problems, e.g. generation of satellite spots, inhomogeneous spots, misplaced or even absent spots, and sample carryover.
In this paper, a new concept of non-contact sample deposition that reduces such problems is introduced. To show the potential
and robustness of this pressure-assisted deposition technique, different sample solutions known to cause severe problems or
to be even impossible to print with conventional microarrayers were accurately printed. The samples included 200 mg mL–1 human serum albumin, highly concentrated sticky cell adhesion proteins, pure high-salt cell-lysis buffer, pure DMSO, and
a suspension of 5-μm polystyrene beads. Additionally, a water-immiscible liquid fluorocarbon, which was shown not to affect
the functionality of the capture molecules, was employed as a lid to reduce evaporation during microarray printing. The fluorocarbon
liquid lid was shown to circumvent hydrolysis of water-sensitive activated surfaces during long-term deposition procedures. 相似文献
113.
114.
V. Tsurkan St. Plogmann M. Demeter D. Hartmann M. Neumann 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,15(3):401-403
X-ray photoelectron spectroscopy was used to investigate ACr2S4 (, Zn, Mn, Fe, Fe:Cu) and BCr2Se4 (, Cu, Hg, Hg:Cu) single crystals. Well defined splitting of the Cr 2p core level has been found. The local magnetic moments of the Cr ions are responsible for the observed effect.
Received 2 November 1999 相似文献
115.
116.
Austin Samakande Ronald D. Sanderson Patrice C. Hartmann 《Journal of polymer science. Part A, Polymer chemistry》2008,46(21):7114-7126
RAFT grafted montmorillonite (MMT) clays [i.e., N,N‐dimethyl‐N‐(4‐(((phenylcarbonothioyl)thio)methyl)benzyl)ethanammonium‐MMT (PCDBAB‐MMT) and N‐(4‐((((dodecylthio)carbonothioyl)thio)methyl)benzyl)‐N,N‐dimethylethanammo‐nium‐MMT (DCTBAB‐MMT)] of various loadings were dispersed in styrene (S) monomer and the resultant mixtures emulsified and sonicated in the presence of a hydrophobe (hexadecane) into miniemulsions. The stable miniemulsions thus obtained were polymerized to yield encapsulated polystyrene‐clay nanocomposites (PS‐CNs). The molar mass and polydispersity index (PDI) of the PS‐CNs depended on the amount of RAFT agent in the system, in accordance with the features of the RAFT process. The morphology of the PS‐CNs ranged from partially exfoliated to an intercalated morphology, depending on the percentage clay loading. The thermomechanical properties of the PS‐CNs were better than those of the neat PS polymer, and were dependent on the molar mass, PS‐CN morphology and clay loading. The similarities and differences of the PS‐CNs prepared here by miniemulsion polymerization were compared to those prepared using the same RAFT agents and polymer system by bulk polymerization (as reported by us in a previous article). © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7114–7126, 2008 相似文献
117.
Gottfried WAGNER Bernhard Traulich KarlM. Hartmann Dieter Oesterhelt 《Photochemistry and photobiology》1987,46(3):393-402
Quantitative action spectroscopy was performed in Halobacterium halobium. using four suited pigment mutants, namely the bacteriorhodopsin and halorhodopsin positive mutant strain M-l (BR+, HR+), the bacteriorhodopsin positive but halorhodopsin negative strain M-18 (BR+, HR-), the bacteriorhodopsin negative but halorhodopsin positive strain L-33 (BR-, HR+), and the bacteriorhodopsin and halorhodopsin negative strain L-07 (BR-, HR+). The approached questions were: First, photoenergetic synergism of halorhodopsin and bacteriorhodopsin in intact cells; second, photochromism and cellular function of the blue light-absorbing intermediates, i.e. M-412 and HR-410 in bacteriorhodopsin and in halorhodopsin, respectively. Dark-adapted cells of mutant strain M-l show wavelength-dependency of quantum yield of photo-phosphorylation, φATP. An 1.4-fold enhancement was found at 575 nm wavelength where the long wavelength absorbance bands of bacteriorhodopsin and halorhodopsin intersect. The enhancement vanished after a 30 min pulse of orange light (600 Wm-2 bandpass from 495 to 750 nm), but was restored after a 30 min pulse of blue light (100 Wm-2 bandpass from 325 to 480 nm). Photoreversibility of this enhancement probably reflects phototransformation of halorhodopsin from its ground state into its inactive intermediate, HR-410, and vice versa. The halorhodopsin-mediated enhancement with maximum quantum yield of photophosphorylation, φATP= 0.06, i.e. a quantum requirement of = 17 photons/ATP, is partly substituted by a rise in phosphate potential and explained in terms of a voltage-regulated gating effect on the H+-driven ATP-synthase, superimposed on the chemiosmotic mechanism of energy coupling. The blue-absorbing photochromic intermediate, M-412 of bacteriorhodopsin, dissipates light energy upon photoexcitation that is reflected by a spectral decline in quantum yield of photophosphorylation to a minimum value of = 0.01 at 415 nm, i.e. a quantum requirement of = 100 photons/ATP. 相似文献
118.
Muhammad Nawaz Tahir Markus Messerschmidt Michael Klein Victor Martinez Patrick Theato Nadine Metz Sonngard Hartmann Ute Kolb Vadim Ksenofontov Franz Renz Wolfgang Tremel 《Polyhedron》2009,28(9-10):1728-1733
The precursor [FeIII(L)Cl (L = N,N′-bis(2′-hydroxy-3′-methyl-benzyliden)-1,7-diamino-4-azaheptane) is combined with [Mo(CN)8]4? yields a star shaped nona-nuclear cluster, [MoIV{(CN)FeIII(L)}8]Cl4. This Fe8Mo molecule is a high-spin system at room temperature. On cooling to 20 K some of the iron(III) centres in the molybdenum(IV)-star switch to the low-spin state as proven by Mössbauer spectroscopy. This molecule was deposited on TiO2 nanowires by electrostatic interactions between the cluster cations and the surface functionalized titanium oxide nanowire. The synthesis and surface binding of the multistable molecular switch was demonstrated using IR and UV–Vis spectroscopy (high-resolution) transmission electron microscopy ((HR)TEM) and Mössbauer spectroscopy. High- and low-temperature Mössbauer spectra indicate that the spin state transition of the free cluster molecules is preserved after surface binding. The above results emphasize the possibility of fabricating molecule-based low-dimensional structures by using traditional bottom-up approaches based on the electrostatic interaction between the cluster cations and polymer functionalized nanowires. These results can be generalized for the application to both charged and non-charged molecules. 相似文献
119.
Carsten Georgi Nicolai Hartmann Tobias Gokus Alexander A. Green Mark C. Hersam Prof. Achim Hartschuh Prof. 《Chemphyschem》2008,9(10):1460-1464
The temporal evolution of photoluminescence in individual single‐walled carbon nanotubes (SWNT) under strong laser irradiation is studied and pronounced blinking and bleaching is observed, caused by photoinduced oxidation that subsequently quenches mobile excitons. The nanotubes are isolated with sodium cholate and spun onto either a glass or mica surface. Their bleaching behavior is investigated for variable laser intensities in air and argon atmosphere. The decay rate for luminescence bleaching generally increases with higher laser intensity, however saturating on mica substrates, which is attributed to limited availability of oxygen in the vicinity of the nanotubes. Step‐like events in the luminescence time traces corresponding to single oxidation events are analyzed regarding relative step height and suggest an exciton diffusion range of about 105 nm. 相似文献
120.
The intensity distribution of the Cr–I 428.97 nm resonant and 520.60 nm non-resonant lines was studied as a function of the distance from the anode in a low pressure DC-GD fitted with a Cr metal cathode and operated in various gas atmospheres, including helium (P = 4 mbar), ambient air and water vapor (P = 0.8 mbar). In the helium and ambient air atmospheres, the intensity peaks occurred in the near cathode region (cathode glow) in accordance with the literature. When operated in water vapor, however, the Cr–I 428.97 nm resonant line disappeared, whereas the intensity of the non-resonant 520.60 nm line was enhanced. This result may be attributed to resonant energy transfer collisions taking place between OH radicals excited to the first vibrational level and Cr*428 atoms excited to the z7P0 upper level of the 428.97 nm transition. The similar gas phase composition encountered with a DC electrolyte cathode atmospheric pressure glow discharge (ELCAD) and the Cr metal cathode GD operating under a low pressure of water vapor suggests that the zero intensity of the Cr resonance lines (428.97 nm, 360.53 nm) produced in the ELCAD may be attributed to similar energy transfer processes. Our results show that the intensity of the Cr–I 520.60 nm line can be used for analytical purposes in the ELCAD. 相似文献