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Multi-colour organic light-emitting displays by solution processing 总被引:13,自引:0,他引:13
Müller CD Falcou A Reckefuss N Rojahn M Wiederhirn V Rudati P Frohne H Nuyken O Becker H Meerholz K 《Nature》2003,421(6925):829-833
Organic light-emitting diodes (OLEDs) show promise for applications as high-quality self-emissive displays for portable devices such as cellular phones and personal organizers. Although monochrome operation is sufficient for some applications, the extension to multi-colour devices--such as RGB (red, green, blue) matrix displays--could greatly enhance their technological impact. Multi-colour OLEDs have been successfully fabricated by vacuum deposition of small electroluminescent molecules, but solution processing of larger molecules (electroluminescent polymers) would result in a cheaper and simpler manufacturing process. However, it has proved difficult to combine the solution processing approach with the high-resolution patterning techniques required to produce a pixelated display. Recent attempts have focused on the modification of standard printing techniques, such as screen printing and ink jetting, but those still have technical drawbacks. Here we report a class of electroluminescent polymers that can be patterned in a way similar to standard photoresist materials--soluble polymers with oxetane sidegroups that can be crosslinked photochemically to produce insoluble polymer networks in desired areas. The resolution of the process is sufficient to fabricate pixelated matrix displays. Consecutive deposition of polymers that are luminescent in each of the three RGB colours yielded a device with efficiencies comparable to state-of-the-art OLEDs and even slightly reduced onset voltages. 相似文献
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Heinrich Labhart 《Cellular and molecular life sciences : CMLS》1947,3(1):36-37
Summary There is described an apparatus to produce optically a set of error curves of variable height and breadth. Electrophoresis-diagrams obtained with the arrangements ofLongsworth andPhilpot-Svensson may be evaluated by comparison of the measured curve with the corresponding curve of the set. 相似文献
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Summary A single subcutaneous injection of synthalin-A does not affect the cytoplasma ofA-cells in pancreatic islets of the rat during the 1st–5th day of life, in contrast to adult animals. Selective action was found on mitoticA-cells: reduction of mitotic frequency to 25% of the normal rate, and pathological mitoses in the sense of the so-called primary effect. The mitoses ofB-cells, exocrine pancreatic cells and intestinal epithelia seemed to be unchanged, although the mitotic rate was higher than inA-cells. 相似文献
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Strauss J Zhang Q Verleyen P Huybrechts J Neupert S Predel R Pauwels K Dircksen H 《Cellular and molecular life sciences : CMLS》2011,68(20):3403-3423
We report identification of a beta-type pigment-dispersing hormone (PDH) identical in two water flea species, Daphnia magna and Daphnia pulex. It has been identified by cloning of precursors, chromatographic isolation from tissue extracts followed by immunoassays
and de novo-mass spectrometric sequencing. The peptide is restricted to a complex system of distinct interneurons in the brain
and visual ganglia, but does not occur in neurosecretory cells projecting to neurohemal organs as in decapod crustaceans.
Thirteen neuron types individually identified and reconstructed by immunohistochemistry were almost identical in terms of
positions and projection patterns in both species. Several neurons invade and form plexuses in visual ganglia and major brain
neuropils including the central body. Five neuron types show contralateral pathways and form plexuses in the lateral, dorsal,
or postlateral brain neuropils. Others are local interneurons, and a tritocerebral neuron connects the protocerebrum with
the neuropil of the locomotory second antenna. Two visual ganglia neuron types lateral to the medulla closely resemble insect
medulla lateral circadian clock neurons containing pigment-dispersing factor based upon positional and projectional criteria.
Experiments under 12:12 h light/dark cycles and constant light or darkness conditions showed significant circadian changes
in numbers and activities of one type of medulla lateral PDH neuron with an acrophase in the evening. This simple PDH system
shows striking homologies to PDH systems in decapod crustaceans and well-known clock neurons in several insects, which suggests
evolutionary conservation of an ancient peptidergic interneuronal system that is part of biological clocks. 相似文献
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Summary The morphology of ovarian follicles in the temperature-sensitive female-sterile mutantl(1)su(f)
mad-ts
has been studied by means of light and electron microscopy. As the follicle cells gradually degenerate at the restrictive temperature (29°C) the follicles become increasingly disorganized with respect to shape and polarity.Acknowledgments. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 46). We wish to thank Mrs R. Koppa for excellent technical assistance and Mrs G. Mahlke for photographic work. We are also indebted to Dr D. Zissler, Dr E. Gateff and Prof. K. Sander for many helpful suggestions. 相似文献
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Vennerstrom JL Arbe-Barnes S Brun R Charman SA Chiu FC Chollet J Dong Y Dorn A Hunziker D Matile H McIntosh K Padmanilayam M Santo Tomas J Scheurer C Scorneaux B Tang Y Urwyler H Wittlin S Charman WN 《Nature》2004,430(7002):900-904
The discovery of artemisinin more than 30 years ago provided a completely new antimalarial structural prototype; that is, a molecule with a pharmacophoric peroxide bond in a unique 1,2,4-trioxane heterocycle. Available evidence suggests that artemisinin and related peroxidic antimalarial drugs exert their parasiticidal activity subsequent to reductive activation by haem, released as a result of haemoglobin digestion by the malaria-causing parasite. This irreversible redox reaction produces carbon-centred free radicals, leading to alkylation of haem and proteins (enzymes), one of which--the sarcoplasmic-endoplasmic reticulum ATPase PfATP6 (ref. 7)--may be critical to parasite survival. Notably, there is no evidence of drug resistance to any member of the artemisinin family of drugs. The chemotherapy of malaria has benefited greatly from the semi-synthetic artemisinins artemether and artesunate as they rapidly reduce parasite burden, have good therapeutic indices and provide for successful treatment outcomes. However, as a drug class, the artemisinins suffer from chemical (semi-synthetic availability, purity and cost), biopharmaceutical (poor bioavailability and limiting pharmacokinetics) and treatment (non-compliance with long treatment regimens and recrudescence) issues that limit their therapeutic potential. Here we describe how a synthetic peroxide antimalarial drug development candidate was identified in a collaborative drug discovery project. 相似文献
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Raabe R Sida JL Charvet JL Alamanos N Angulo C Casandjian JM Courtin S Drouart A Durand DJ Figuera P Gillibert A Heinrich S Jouanne C Lapoux V Lepine-Szily A Musumarra A Nalpas L Pierroutsakou D Romoli M Rusek K Trotta M 《Nature》2004,431(7010):823-826
Quantum tunnelling through a potential barrier (such as occurs in nuclear fusion) is very sensitive to the detailed structure of the system and its intrinsic degrees of freedom. A strong increase of the fusion probability has been observed for heavy deformed nuclei. In light exotic nuclei such as 6He, 11Li and 11Be (termed 'halo' nuclei), the neutron matter extends much further than the usual nuclear interaction scale. However, understanding the effect of the neutron halo on fusion has been controversial--it could induce a large enhancement of fusion, but alternatively the weak binding energy of the nuclei could inhibit the process. Other reaction channels known as direct processes (usually negligible for ordinary nuclei) are also important: for example, a fragment of the halo nucleus could transfer to the target nucleus through a diminished potential barrier. Here we study the reactions of the halo nucleus 6He with a 238U target, at energies near the fusion barrier. Most of these reactions lead to fission of the system, which we use as an experimental signature to identify the contribution of the fusion and transfer channels to the total cross-section. At energies below the fusion barrier, we find no evidence for a substantial enhancement of fusion. Rather, the (large) fission yield is due to a two-neutron transfer reaction, with other direct processes possibly also involved. 相似文献