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排序方式: 共有237条查询结果,搜索用时 15 毫秒
41.
Marí C. Santos Krissie D. Soares Betina M. Beltrame Natally S. B. Toson Maria do Carmo B. Pimentel Sérgio A. L. Bordignon Miriam A. Apel Andreas S. L. Mendez Amélia T. Henriques 《化学与生物多样性》2021,18(7):e2100041
The present study investigates the chemical composition, anti-inflammatory, and antihypertensive activities, in vitro, from extracts of Cuphea lindmaniana and Cuphea urbaniana leaves. The extraction was performed ultrasound-assisted, and UHPLC/MS analysis was in positive mode ionization. The anti-inflammatory activity of the extracts and miquelianin were assayed at concentrations 0.001–10 μg/mL by chemotaxis on rat polymorphonuclear neutrophils. The antihypertensive activity was performed by angiotensin-converting enzyme (ACE) inhibition. From the nineteen proposed compounds, six of them are described for the first time in this genus. The extracts displayed antichemotactic effect with a reduction of 100 % of the neutrophil migration, in vitro, in most concentrations. The ACE-inhibition presented results ranging from 19.58 to 22.82 %. In conclusion, C. lindmaniana and C. urbaniana extracts contain a rich diversity of flavonoids and display in vitro anti-inflammatory and antihypertensive potential. Thus, this study could serve as a scientific baseline for further investigation, on developmental novel products with therapeutic actions. 相似文献
42.
Daniel Apel Michele Brunelli Mohammed El-Gahry J. Christoph Geller Bernward Lauer Marc-Alexander Ohlow 《Indian pacing and electrophysiology journal》2018,18(5):159-164
Aims
The aim of this study was to analyze whether local application of 3% hydrogen peroxide (H2O2) additionally to standard antibiotic prophylaxis following implantation of cardiac implantable electronic devices (CIED) reduces the incidence of pocket infections (PI).Methods
In this observational case-control study every patient from the group additionally treated with H2O2 was matched with two patients out of the control group for age, male-gender, body-mass-index and operation time. The incidence of PI within 365 days after device implantation was compared.Results
During the 5-year study period, 429 consecutive patients were additionally treated with H2O2 and matched with 858 patients undergoing standard treatment (mean age 69?±?12 years, 876 males (67.4%), body-mass-index 28?±?4.0?kg/m2 and operation time 45?±?23?min). Except for a more frequent use of dual-platelet-inhibition in the H2O2-group, clinical characteristics were otherwise similar. A total of 23 (1.78%) PIs occurred, most of them (14/23; 61%) during the first 45 days after implantation procedure. The use of H2O2 was associated with a significant reduction (3/429?=?0.69% versus 20/858?=?2.33%; p?=?0.04), although patients of the H2O2 treated group received more complex procedures increasing the risk of PI.Conclusion
Intraoperative local application of 3% H2O2 seems to be associated with a significant reduced incidence of PI following implantation of CIED. Because of its non-randomized character this trial should be considered as a hypothesis generating study. 相似文献43.
Sönke Runge Barbara van Cleve Nikolai Lebedev Gregory Armstrong Klaus Apel 《Planta》1995,197(3):490-500
Mutant lines of Arabidopsis thaliana that are either blocked at various steps of the biosynthetic pathway of chlorophyll (Chl) or that are disturbed in one of the subsequent steps leading to the assembly of an active photosynthetic membrane were isolated by screening for Chl-deficient xantha (xan) mutants. Only mutants that segregated in a 31 ratio, that contained the same carotenoid spectrum as etiolated wild-type seedlings and less than 2% of the Chl of wild-type control seedlings, and whose Chl content was not affected by the addition of sucrose to the growth medium were selected for a more detailed analysis. As a final test for the classification of the selected mutants, light-grown xan mutants were vacuum-infiltrated and incubated with the common precursor of tetrapyrroles, -aminolevulinic acid (ALA), in the dark. Two major groups of mutants could be distinguished. Some of the mutants were blocked at various steps of the Chl pathway between ALA and protochlorophyllide (Pchlide) and did not accumulate the latter in the dark. The other mutants accumulated Pchlide in the dark regardless of whether exogenous ALA was added. This latter group could be subdivided into mutants with a biochemical lesion in a recently discovered second light-dependent Pchlide reduction step that occurs in green plants and mutants that have blocks in the assembly of Chl protein complexes. In the present work a total of seven different loci could be defined genetically in Arabidopsis that affect the synthesis of Chl and its integration into the growing photosynthetic membrane.Abbreviations ALA
-aminolevulinic acid
- Chl
chlorophyll
- Chlide
chlorophyllide
- Pchlide
protochlorophyllide
- POR
NADPH-Protochlorophyllide oxidoreductase
-
xan
xantha
This study was initiated while one of the authors (K.A.) was on sabbatical leave in the laboratory of Dr. C. Somerville (MSU, East Lansing, Mich., USA). We are extremely grateful to Dr. Somerville and his coworkers for advice and support during this time. This research was supported by the Deutsche Forschungsgemeinschaft and the Schweizerischer Nationalfonds. 相似文献
44.
The CO2 compensation concentration (Γ) and leaf anatomy were determined in 107 species of six tribes of Brassicaceae. There was an abundant bundle-sheath in all investigated species. The Moricandia syndrome, characterized by a high concentration of chloroplasts in the bundle-sheath cells and Γ values < 30 cm3(CO2) m-3, was found within species of the genera Moricandia, Diplotaxis and Brassica. Available results from molecular systematics indicate a common phylogenetic ancestor, suggesting monophyletic evolution
of the syndrome within the tribe Brassiceae. Nevertheless, Γ values of about 30 cm3 m-3 in some other genera of the tribes
Brassiceae and Sisymbrieae indicate an evolutionarily sliding, gradual transition from C3 ancestors.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
45.
Distinct roles for light-dependent NADPH:protochlorophyllide oxidoreductases (POR) A and B during greening in higher plants 总被引:5,自引:2,他引:3
Sönke Runge Ulrich Sperling Geneviève Frick Klaus Apel Gregory A. Armstrong 《The Plant journal : for cell and molecular biology》1996,9(4):513-523
Light-dependent NADPH:protochlorophyllide oxidoreductase (POR), a nuclear-encoded plastid-localized enzyme, catalyzes the photoreduction of protochlorophyllide (Pchlide) to chlorophyllide in higher plants, algae and cyanobacteria. Angiosperms require light for chlorophyll (Chl) biosynthesis and have recently been shown to contain two POR-encoding genes, PorA and PorB , that are differentially regulated by light and developmental state. PorA expression rapidly becomes undetectable after illumination of etiolated seedlings, whereas PorB expression persists throughout greening and in adult plants. In order to study the in vivo functions of Arabidopsis POR A and POR B we have abolished the expression of PorA through the use of the phytochrome A-mediated far-red high irradiance response. Wild-type seedlings grown in continuous far-red light (cFR) display the morphology of white light (WL)-grown seedlings, but contain only traces of Chl and do not green upon transfer to WL. This cFR-induced greening defect correlates with the absence of PorA mRNA, the putative POR A protein, phototransformable Pchlide-F655 , and with strongly reduced POR enzymatic activity in plant extracts. In contrast, a cFR-grown phyA mutant expresses the PorA gene, accumulates Chl and visibly greens in WL. Furthermore, constitutive overexpression of POR A in cFR-grown transgenic Arabidopsis wild-type seedlings restores Chl accumulation and WL-induced greening. These data demonstrate that POR A is required for greening and that the availability of POR A limits Chl accumulation during growth in cFR. POR B apparently provides a means to sustain light-dependent Chl biosynthesis in fully greened, mature plants in the absence of phototransformable Pchlide-F655 . 相似文献
46.
47.
The effect of chemical stress on the polypeptide composition of the intercellular fluid of barley (Hordeum vulgare L.) and tomato (Lycopersicon esculentum Mill.) leaves has been studied. In some dicotyledonous plant species, including tomato, exposure to chemical stress leads to the denovo synthesis of intercellular proteins known as pathogenesis-related proteins which have been implicated to be part of a defence mechanism. In barley, however, no such changes in the polypeptide composition of the intercellular fluid could be detected. On the other hand, similar stress conditions induce in barley a strong accumulation of mRNA encoding leaf-specific thionins. These barley thionins represent a novel class of cell-wall proteins toxic to phytopathogenic fungi and are possibly involved in the defence mechanism. These proteins could not be detected in tomato plants. In contrast to the pathogenesis-related proteins of dicotyledonous plants, the leaf-specific thionins of barley are not present in the intercellular fluid of leaves. These results indicate that barley may have evolved a different mechanism to cope with the presence of stress.Abbreviations PAGE
polyacrylamide gel electrophoresis
- PR
pathogenesis-related
- SDS
sodium dodecyl sulfate 相似文献
48.
R Schulz K Steinmüller M Klaas C Forreiter S Rasmussen C Hiller K Apel 《Molecular & general genetics : MGG》1989,217(2-3):355-361
Summary The primary structure of the NADPH-protochlorophyllide oxidoreductase of barley has been deduced from the nucleotide sequence
of a cloned full-length cDNA. This cDNA hybridizes to a 1.7 kb RNA whose steady-state level in dark-grown seedlings is drastically
reduced upon illumination. The predicted amino acid sequence (388 residues in length) includes a transit peptide of 74 amino
acids whose end point has been delimited by sequencing the N-terminus of the mature protein. Expression of the cDNA inEscherichia coli leads to the synthesis of an enzymatically active precursor of the NADPH-protochlorophyllide oxidoreductase. Activity of
this protein in bacterial lysates is completely dependent on the presence of NADPH and protochlorophyllide and requires light. 相似文献
49.
50.
Summary In etiolated barley seedlings a highly abundant mRNA encoding a 15 000 Mr polypeptide is present whose concentration rapidly declines upon illumination. The amino acid sequence of the 15 000 Mr polypeptide has been deduced from cDNA sequences and the polypeptide has been identified as a high-molecular-weight thionin precursor. Closely related thionins, most of them highly toxic, have been described previously in several higher plants. In cereals the occurrence of these thionins has been thought to be confined to the seeds. Our present data demonstrate that, in additon to endosperm-specific hordothionin mRNA, a closely related but distinct second group of thionin mRNAs is present in the barley leaf during early seedling development. Since the appearance of the bordothionin mRNA is not controlled by light, two different gene families for thionins exist whose expression seems to be under a different mode of developmental control.Dedicated to Prof. W. Halbsguth on the occasion of his 75th birthday 相似文献