全文获取类型
收费全文 | 50篇 |
免费 | 0篇 |
国内免费 | 2篇 |
专业分类
现状及发展 | 33篇 |
研究方法 | 3篇 |
综合类 | 15篇 |
自然研究 | 1篇 |
出版年
2016年 | 1篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2000年 | 1篇 |
1994年 | 1篇 |
1988年 | 2篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 6篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1963年 | 1篇 |
1956年 | 1篇 |
1955年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
1945年 | 2篇 |
排序方式: 共有52条查询结果,搜索用时 926 毫秒
11.
Summary A method of staining bacterial colonies with the new N.N.C.D. reagent is described that has been used in the course of a research work on the influence of soft X-rays and slow cathode rays on microbes. 相似文献
12.
Summary Naphthalene-sulphonates of diazo compounds, which are especially suitable as reagents for the colorimetric estimation of biologically important phenols, are communicated. 相似文献
13.
14.
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
15.
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
16.
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
17.
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
18.
19.
Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis 总被引:1,自引:0,他引:1
International Multiple Sclerosis Genetics Consortium;Wellcome Trust Case Control Consortium Sawcer S Hellenthal G Pirinen M Spencer CC Patsopoulos NA Moutsianas L Dilthey A Su Z Freeman C Hunt SE Edkins S Gray E Booth DR Potter SC Goris A Band G Oturai AB Strange A Saarela J Bellenguez C Fontaine B Gillman M Hemmer B Gwilliam R Zipp F Jayakumar A Martin R Leslie S Hawkins S Giannoulatou E D'alfonso S Blackburn H Martinelli Boneschi F Liddle J Harbo HF Perez ML Spurkland A Waller MJ Mycko MP 《Nature》2011,476(7359):214-219
Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis. 相似文献
20.
K. Bachinann A. Konrad E. Oeldorf H. Hemmer 《Cellular and molecular life sciences : CMLS》1978,34(3):331-332
Summary Specimens of the green toad,Bufo viridis, from Morocco to Kirgizistan, have identical DNA amounts per erythrocyte nucleus. 1 specimen from Kirgizistan is a tetraploid. Of 3 closely related species,B. calamita andB. brongersmai have about the same DNA amount asB. viridis, whileB. latastii from Afghanistan has 36% more DNA per nucleus. 相似文献