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81.
Anttonen MJ Lehesranta S Auriola S Röhlig RM Engel KH Kärenlampi SO 《Journal of proteome research》2010,9(12):6160-6168
Comparative targeted compositional analysis is currently an important element in the safety assessment of genetically modified plants. Profiling methods have been suggested as nontargeted tools to improve the detection of possible unintended effects. In this study, the capability of 2-dimensional electrophoresis to detect significant differences among seven conventional maize (Zea mays) cultivars grown in six different locations in Germany during two consecutive seasons was evaluated. Besides maize genotype, both geographic location and season had a significant effect on protein profiles. Differences as high as 55- and 53-fold in the quantity of specific proteins were recorded, the median observed difference being around 6- and 5-fold between the genotypes and growing locations, respectively. Understanding the variation in the quantity of individual proteins should help to put the variation of endogenous proteins and the novel proteins in the genetically modified plants in perspective. This together with the targeted analyses the profiling methods, including proteomics, could also help to get a deeper insight into the unintended alterations that might have occurred during the genetic modification process. 相似文献
82.
83.
Otte JM Schwenger M Brunke G Schmitz F Otte C Kiehne K Kloehn S Mönig H Schmidt WE Herzig KH 《Regulatory peptides》2007,144(1-3):82-90
BACKGROUND AND AIM: Immunomodulatory and protective properties have been identified for the keratinocyte growth factor (KGF). For hepatocytes, pro-proliferative and anti-apoptotic effects of this growth factor have been reported in vitro. This study was designed to characterize a putative role of KGF in observed histomorphological changes in both, human and experimental liver fibrosis. METHODS: Liver fibrosis and cirrhosis was induced in rats by repetitive exposure to phenobarbitone and increasing doses of carbon tetrachloride. Human samples were obtained from patients undergoing surgery for partial hepatectomy or transplantation. Organ samples were scored for inflammation and morphological changes. Expression of KGF and its receptor (KGFR) mRNA was quantified by real-time RT-PCR. Protein expression and receptor phosphorylation was determined by Western blot analysis. In-situ hybridization and immunohistochemistry were utilized to determine distribution of KGF and KGFR in the liver. RESULTS: Expression of KGF was significantly increased in damaged liver tissue in correlation to the degree of fibrosis, whereas expression of the receptor was up-regulated in early stages of liver fibrosis and down-regulated in cirrhotic organs. Protein expression of this growth factor and its receptor correlated with the alterations in mRNA. KGF expression was restricted to mesenchymal cells, whereas expression of KGFR was detected on hepatocytes only. CONCLUSION: The expression of KGF and KGFR is differentially and significantly regulated in damaged liver tissue. This growth factor might therefore not only contribute to morphological alterations but also regeneration of liver parenchyma most likely mediated by indirect mechanisms of action. 相似文献
84.
A genetic algorithm (GA) was applied for the optimisation of an enzyme assay composition respectively the enzyme activity of a recombinantly produced FADH(2)-dependent halogenating enzyme. The examined enzyme belongs to the class of halogenases and is capable to halogenate tryptophan regioselective in position 5. Therefore, the expressed trp-5-halogenase can be an interesting tool in the manufacturing of serotonin precursors. The application of stochastic search strategies (e.g. GAs) is well suited for fast determination of the global optimum in multidimensional search spaces, where statistical approaches or even the popular classical one-factor-at-a-time method often failures by misleading to local optima. The concentrations of six different medium components were optimised and the maximum yield of the halogenated tryptophan could be increased from 3.5 up to 65%. 相似文献
85.
Oncogenic point mutations in the Myb DNA-binding domain alter the DNA-binding properties of Myb at a physiological target gene 下载免费PDF全文
The oncoprotein v-Myb of avian myeloblastosis virus (AMV) transforms myelomonocytic cells by deregulating specific target genes. Previous work has shown that the oncogenic potential of v-Myb was activated by truncation of N- and C-terminal sequences of c-Myb and was further increased by amino acid substitutions in the DNA-binding domain and other parts of the protein. We have analyzed the activation of the chicken lysozyme gene which is strongly activated by c-Myb but not by its oncogenic counterpart v-Myb. We report that Myb acts on two different cis-regulatory elements, the promoter and an enhancer located upstream of the gene. Interestingly, the activation of the enhancer was abolished by the oncogenic amino acid substitutions. We demonstrated that a single Myb-binding site is responsible for the activation of the lysozyme enhancer by Myb and showed that the v-Myb protein of AMV was unable to bind to this site. Our data demonstrate for the first time that oncogenic activation of Myb alters its DNA-binding specificity at a physiological Myb target gene. 相似文献
86.
Simone Schehka Karl-Heinz Esser Elke Zimmermann 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2007,193(8):845-852
Empirical research on human and non-human primates suggests that communication sounds express the intensity of an emotional
state of a signaller. In the present study, we have examined communication sounds during induced social interactions of a
monogamous mammal, the tree shrew. To signal their unwillingness to mate, female tree shrews show defensive threat displays
towards unfamiliar males paralleled by acoustically variable squeaks. We assumed that the distance between interacting partners
as well as the behavior of the male towards the female indicates the intensity of perceived social threat and thereby the
arousal state of a female. To explore this hypothesis we analyzed dynamic changes in communication sounds uttered during induced
social interactions between a female and an unfamiliar male. Detailed videographic and sound analyzes revealed that the arousal
state predicted variations in communication sound structure reliably. Both, a decrease of distance and a male approaching
the female led to an increase in fundamental frequency and repetition rate of syllables. These findings support comparable
results in human and non-human primates and suggest that common coding rules in communication sounds govern acoustic conflict
regulation in mammals. 相似文献
87.
88.
Susanna Peters Jafargholi Imani Vera Mahler Kay Foetisch Susanne Kaul Kathrin E. Paulus Stephan Scheurer Stefan Vieths Karl-Heinz Kogel 《Transgenic research》2011,20(3):547-556
Pathogenesis-related protein-10 (PR10) is a ubiquitous small plant protein induced by microbial pathogens and abiotic stress
that adversely contributes to the allergenic potency of many fruits and vegetables, including carrot. In this plant, two highly
similar genes encoding PR10 isoforms have been isolated and designated as allergen Dau c 1.01 and Dau c 1.02. The aim of the
study was to generate PR10-reduced hypoallergenic carrots by silencing either one of these genes in transgenic carrots by
means of RNA interference (RNAi). The efficiency of gene silencing by stably expressed hairpin RNA (hnRNA) was documented
by means of quantitative RT-PCR (qPCR) and immunoblotting. Quantification of the residual protein revealed that PR10 accumulation
was strongly decreased compared with untransformed controls. Treatment of carrot plants with the PR protein-inducing chemical
salicylic acid resulted in an increase of PR10 isoforms only in wild-type but not in Dau c 1-silenced mutants. The decrease
of the allergenic potential in Dau c 1-silenced plants was sufficient to cause a reduced allergenic reactivity in patients
with carrot allergy, as determined with skin prick tests (SPT). However, simultaneous silencing of multiple allergens will
be required to design hypoallergenic carrots for the market. Our findings demonstrate the feasibility of creating low-allergenic
food by using RNAi. This constitutes a reasonable approach to allergen avoidance. 相似文献
89.
CyLoP-1: a novel cysteine-rich cell-penetrating peptide for cytosolic delivery of cargoes 总被引:1,自引:0,他引:1
Jha D Mishra R Gottschalk S Wiesmüller KH Ugurbil K Maier ME Engelmann J 《Bioconjugate chemistry》2011,22(3):319-328
Cell-penetrating peptides (CPPs) may have impli-cations in biomedical sciences by improving the delivery of a wide variety of drugs through the membrane barrier. CPPs are generally taken up by endocytotic pathways, and vesicular encapsulation is a limiting factor in the area of intracellular targeting. A novel, cationic cysteine-rich CPP, CyLoP-1, has been developed exhibiting distinguished diffused cytosolic distribution along with endosomal uptake at low micromolar concentrations. Comparative uptake analysis with known CPPs showed CyLoP-1 as a promising delivery vector to access the cytosol in a variety of cell types. In addition to the positively charged residues, the presence of cysteines and tryptophans proved to be essential to maintain its functionality. Also, the oxidation status of the cysteines played an important role for the uptake efficiency of CyLoP-1, with the disulfide-containing form being more effective. The distinct feature of CyLoP-1 to enter the cytosol was further explored by the covalent attachment of cargoes of different nature and sizes. In particular, induction of caspase-3 activity (indicating apoptosis) by a CyLoP-1-SmacN7 conjugate proved successful delivery of the pro-apoptotic cargo to its site of action in the cytosol. Efficient intracellular delivery into the entire cytosol already at low micromolar concentrations makes CyLoP-1 a promising candidate for cytosolic delivery of cargoes of small sizes. Thus, this peptide might prove to be useful for efficient transmembrane delivery of agents directed to cytosolic targets. 相似文献
90.
Kriskamol Na Jom Thomas Frank Karl-Heinz Engel 《Metabolomics : Official journal of the Metabolomic Society》2011,7(1):102-117
A metabolite profiling methodology based on capillary gas chromatography/mass spectrometry (GC/MS) was employed to investigate
time-dependent metabolic changes in the course of the sprouting of mung beans (Vigna radiata). Intact mung beans and sprout samples taken during the germination process were subjected to an extraction and fractionation
procedure covering a broad spectrum of lipophilic (e.g. fatty acid methyl esters, hydrocarbons, fatty alcohols, sterols) and
hydrophilic (e.g. sugars, acids, amino acids, amines) low molecular weight constituents. Investigation of the obtained fractions
by GC resulted in the detection of more than 450 distinct peaks of which 146 were identified by means of MS. Statistical assessment
of the metabolite profiling data via principal component analysis demonstrated that the metabolic changes during the sprouting
of mung beans are reflected by time-dependent shifts of the scores which were comparable for two spouting processes independently
conducted under the same conditions. Analysis of the loadings showed that polar metabolites were major contributors to the
separation along the first principal component. The dynamic changes of single metabolites revealed significantly increased
levels of monosaccharides, organic acids and amino acids and a decrease in fatty acid methyl esters in mung bean sprouts. 相似文献