全文获取类型
收费全文 | 276篇 |
免费 | 35篇 |
出版年
2023年 | 2篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 17篇 |
2011年 | 20篇 |
2010年 | 16篇 |
2009年 | 13篇 |
2008年 | 13篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 14篇 |
2004年 | 12篇 |
2003年 | 12篇 |
2002年 | 4篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1991年 | 10篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有311条查询结果,搜索用时 31 毫秒
61.
Molecular physiology of adventitious root formation in Petunia hybrida cuttings: involvement of wound response and primary metabolism 总被引:1,自引:0,他引:1
62.
M Siebert A Bechthold M Melzer U May U Berger G Schr?der J Schr?der K Severin L Heide 《FEBS letters》1992,307(3):347-350
Chorismate pyruvate-lyase activity was detected in extracts of Escherichia coli. 4-Hydroxybenzoate was identified as the product of the enzymatic reaction by chemical derivatization and GC-MS analysis. The ubiC gene, coding for the chorismate pyruvate-lyase, was cloned and sequenced. The molecular weight of the gene product was calculated as 18,776 Da and confirmed by expression of the protein in E. coli minicells. The ubiA gene, coding for the 4-hydroxybenzoate octaprenyl transferase, was identified by sequence homology and complementation of a ubiA- strain. It is located directly downstream of ubiC in a typical operon structure. 相似文献
63.
The floral homeotic protein SEPALLATA3 recognizes target DNA sequences by shape readout involving a conserved arginine residue in the MADS‐domain
下载免费PDF全文
![点击此处可从《The Plant journal : for cell and molecular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
64.
J. Gante H. Juraszyk P. Raddatz H. Wurziger S. Bernotat-Danielowski G. Melzer F. Rippmann 《Letters in Peptide Science》1995,2(3-4):135-140
Summary RGD-peptidomimetics are currently being investigated as a class of potential antithrombotics that antagonize the fibrinogen receptor, GP IIb/IIIa, on the surface of platelets. These mimetics are expected to have decisive advantages-such as higher activity and specificity, oral bioavailability and longer duration of action-over known antithrombotics. For further optimization in this respect, novel peptidomimetic GP IIb/IIIa antagonists with an oxazolidinonemethyl central building block were synthesized. This building block proved to be very versatile as an anchor for structurally different C-termini and was the starting point for highly efficient and orally active compounds. 相似文献
65.
Aldona Dobrzycka-Krahel Wojciech Majkowski Magdalena Melzer 《Marine and Freshwater Behaviour and Physiology》2016,49(6):407-413
Gammarids from the Caspian complex have invaded many European waters along the rivers and canals of the inland migration corridors. The species examined in this work are well known as invaders of European freshwater environments, so the colonization of brackish habitats is a phenomenon inviting more detailed investigation. The aim of this study was to determine the condition of the Ponto-Caspian gammarids Pontogammarus robustoides (G.O. Sars, 1894), Obesogammarus crassus (G.O. Sars, 1894), Dikerogammarus haemobaphes (Eichwald, 1841) and Dikerogammarus villosus (Sowinsky, 1894) as expressed by the relationship between total length and the wet weight of specimens in the brackish waters of the Gulf of Gdansk (Poland). The relationships can be regarded as responses to a newly expanded habitat after they overcome the salinity barrier of the southern Baltic Sea coastal waters. All these Ponto-Caspian gammarids demonstrated an increase in weight with increasing total length: P. robustoides (b = 2.852), O. crassus (b = 3.3477), D. haemobaphes (b = 3.7855) and D. villosus (b = 2.6917). The results are an indicator of the relatively good condition of the organisms and indicate that the brackish environment of the Gulf of Gdansk affords them excellent possibilities for growth. 相似文献
66.
Catharina?Melzer Yuanyuan?Yang Ralf?HassEmail authorView authors OrcID profile 《Cell communication and signaling : CCS》2016,14(1):20
Tumor development and tumor progression is not only determined by the corresponding tumor cells but also by the tumor microenvironment. This includes an orchestrated network of interacting cell types (e.g. immune cells, endothelial cells, fibroblasts, and mesenchymal stroma/stem cells (MSC)) via the extracellular matrix and soluble factors such as cytokines, chemokines, growth factors and various metabolites. Cell populations of the tumor microenvironment can interact directly and indirectly with cancer cells by mutually altering properties and functions of the involved partners. Particularly, mesenchymal stroma/stem cells (MSC) play an important role during carcinogenesis exhibiting different types of intercellular communication. Accordingly, this work focusses on diverse mechanisms of interaction between MSC and cancer cells. Moreover, some functional changes and consequences for both cell types are summarized which can eventually result in the establishment of a carcinoma stem cell niche (CSCN) or the generation of new tumor cell populations by MSC-tumor cell fusion. 相似文献
67.
Anapleurotic CO(2) Fixation by Phosphoenolpyruvate Carboxylase in C(3) Plants 总被引:7,自引:6,他引:1
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The role of phosphoenolpyruvate carboxylase in photosynthesis in the C3 plant Nicotiana tabacum has been probed by measurement of the 13C content of various materials. Whole leaf and purified ribulose bisphosphate carboxylase are within the range expected for C3 plants. Aspartic acid purified following acid hydrolysis of this ribulose bisphosphate carboxylase is enriched in 13C compared to whole protein. Carbons 1-3 of this aspartic acid are in the normal C3 range, but carbon-4 (obtained by treatment of the aspartic acid with aspartate β-decarboxylase) has an isotopic composition in the range expected for products of C4 photosynthesis (−5‰), and it appears that more than half of the aspartic acid is synthesized by phosphoenolpyruvate carboxylase using atmospheric CO2/HCO3−. Thus, a primary role of phosphoenolpyruvate carboxylase in C3 plants appears to be the anapleurotic synthesis of four-carbon acids. 相似文献
68.
In a previous study (Melzer and O'Leary, 1987, Plant Physiol. 84, 58–60), we used isotopic methods to show that a substantial fraction of protein-bound aspartic acid in tobacco is derived from anaplerotic synthesis via phosphoenolpyruvate (PEP) carboxylase. Similar studies in soybean (Glycine max L.) and spinach (Spinacia oleracea L.) showed a similar pattern, and this pattern persists with age because of slow protein turnover. A more quantitative analysis indicates that about 40% of protein-bound aspartate is derived in this manner. Analyses of free aspartic and malic acids show that contribution of PEP carboxylase to the synthesis of these acids decreases with increasing age. The C4 plant Zea mays L. did not show this pattern.Abbreviations and Symbols RuBP
ribulose bisphosphate
- PEP
phosphoenolpyruvate
- OAA
oxaloacetic acid
- PGA
3-phosphoglyceric acid
- 13C
carbon-13
- isotopic content
[R(sample)/R(standard)-1] × 1000, where R = [13CO2]/[12CO2]
This work was supported by contract DE-ACO2-83ER 13076 and grant DE-FGO2-86ER13534 from the U.S. Department of Energy. E. M. was supported by a fellowship from Deutsche Forschungsgemeinschaft. We are grateful to Isabel Treichel for assistance with isotopic analyses. 相似文献
69.
A. Weihe M. Meixner B. Wolowczyk R. Melzer Th. Börner 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,81(6):819-824
Summary Methods are described whereby hybridization of mitochondrial (mt) DNA with different DNA probes can definitely distinguish male-fertile and and male-sterile (cms) cytoplasms of sugar beet Beta vulgaris L. We have developed two types of miniassays. (1) Comparative methods requiring the isolation and restriction of total cellular DNA, hybridization with cloned mtDNA fragments from either fertile or male-sterile cytoplasms, and comparison of the hybridization patterns to the fertile-and sterile-specific patterns of mtDNA of sugar beet for the given mtDNA probe. For these analyses, we routinely used 1 g of plant material to determine the type of cytoplasm. (2) Noncomparative (plus-minus) methods requiring neither the isolation of pure DNA nor restriction, electrophoresis, or Southern blotting. Instead, alkaline-SDS plant extracts from as little as 50 mg of plant material were dot-blotted and hybridized with fertile-specific (mitochondrial minicircular DNA) and/or cms-specific probes (consisting of a 2.3-kb mtDNA sequence exclusively occurring in the cms cytoplasm). The assays are simple to perform, give definitive results, are nonde-structive to the plants, and may be used in mass screening of sugar beet populations for hybrid production or in in vitro culture processes. 相似文献
70.
A. B. Bonnema J. M. Melzer M. A. O'Connell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,81(3):339-348
Summary Cybrids have been regenerated following protoplast fusion of iodoacetamide-treated leaf mesophyll cells of Lycopersion esculentum cv UC82 and gamma-irradiated cell suspensions of L. pennellii, LA716. The cybrids were recovered in the regenerant population at a frequency of 19%, no selection pressure was applied for the persistence of the donor cytoplasm. The nuclear genotype of ten cybrids was characterized extensively using isozyme markers, cDNA-based restriction fragment length polymorphisms (RFLPs), and the morphology of the plants. No nuclear genetic information from L. pennellii was detected in the cybrids. The organellar genotype of the cybrids was determined using cloned probes and species-specific RFLPs. All the cybrids had inherited the tomato chloroplast genome and had varying amounts of L. pennellii mitochondrial DNA. The cybrids all had a diploid chromosome number of 24, produced pollen, and set seed. 相似文献