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41.
Hadas Lahat Elon Pras Tsviya Olender Nili Avidan Edna Ben-Asher Orna Man Etgar Levy-Nissenbaum Asad Khoury Avraham Lorber Boleslaw Goldman Doron Lancet Michael Eldar 《American journal of human genetics》2001,69(6):1378-1384
Catecholamine-induced polymorphic ventricular tachycardia (PVT) is characterized by episodes of syncope, seizures, or sudden death, in response to physical activity or emotional stress. Two modes of inheritance have been described: autosomal dominant and autosomal recessive. Mutations in the ryanodine receptor 2 gene (RYR2), which encodes a cardiac sarcoplasmic reticulum (SR) Ca(2+)-release channel, were recently shown to cause the autosomal dominant form of the disease. In the present report, we describe a missense mutation in a highly conserved region of the calsequestrin 2 gene (CASQ2) as the potential cause of the autosomal recessive form. The CASQ2 protein serves as the major Ca(2+) reservoir within the SR of cardiac myocytes and is part of a protein complex that contains the ryanodine receptor. The mutation, which is in full segregation in seven Bedouin families affected by the disorder, converts a negatively charged aspartic acid into a positively charged histidine, in a highly negatively charged domain, and is likely to exert its deleterious effect by disrupting Ca(2+) binding. 相似文献
42.
Nurit Ballas Nehama Zakai Devorah Friedberg Abraham Loyter 《Plant molecular biology》1988,11(4):517-527
Introduction of the plasmids pUC8CaMVCAT and pNOSCAT into plant protoplasts is known to result in transient expression of the chloramphenicol acetyl transferase (CAT) gene. Also, transfection with the plasmid pDO432 results in transient appearance of the luciferase enzyme. In the present work we have used these systems to study the effect of DNA topology on the expression of the above recombinant genes. Linear forms of the above plasmids exhibited much higher activity in supporting gene expression than their corresponding super-coiled structures. CAT activity in protoplasts transfected with the linear forms of pUC8CaMVCAT and pNOSCAT was up to ten-fold higher than that observed in protoplasts transfected by the supercoiled template of these plasmids. This effect was observed in protoplasts derived from two different lines of Petunia hybrida and from a Nicotiana tabacum cell line. Transfection with the relaxed form of pUC8CaMVCAT resulted in very low expression of the CAT gene.Northern blot analysis revealed that the amount of poly(A)+ RNA extracted from protoplasts transformed with the linear forms of the DNA was about 10-fold higher than that found in protoplasts transformed with supercoiled DNA.Southern blot analysis revealed that about the same amounts of supercoiled and linear DNA molecules were present in nuclei of transfected protoplasts. No significant quantitative differences have been observed between the degradation rates of the various DNA templates used. 相似文献
43.
Production of the new antimalarial drug artemisinin in shoot cultures of Artemisia annua L. 总被引:1,自引:0,他引:1
Herman J. Woerdenbag Jos F. J. Lüers Wim van Uden Niesko Pras Theo M. Malingré A. Wilhelm Alfermann 《Plant Cell, Tissue and Organ Culture》1993,32(2):247-257
From aseptically grown Artemisia annua plantlets, shoot cultures were initiated. Using different concentrations of auxine, cytokinine and sucrose, a suitable culture medium was developed, with respect to the growth of the shoots and their artemisinin accumulation. Nitrate concentration and conductivity appeared to be suitable growth parameters. The artemisinin content was measured gas chromatographically. The shoot cultures were maintained in the developed standard medium, consisting of a half concentration of MS-salts with vitamins, 0.2 mg l-1 BAP, 0.05 mg l-1 NAA and 1% sucrose. The growth of the shoots and the artemisinin content remained stable for a longer period. They showed considerable photosynthetic activity and generally contained ca. 0.08% artemisinin on a dry weight basis. The highest artemisinin content found was 0.16% in the above mentioned standard medium, but also on the same medium with 0.5% sucrose. Attempts were made to further improve the artemisinin production by varying the medium composition through addition of gibberellic acid or casein hydroly-state; by omitting plant growth regulators; by precursor feeding, i.e. mevalonic acid; by influencing the biosynthesis routing through inhibition of the sterol synthesis by miconazole, naftifine or terbinafine; by changing gene expression with 5-azacytidine or colchicine; and by elicitation, using cellulase, chitosan, glutathione or nigeran. Enhanced artemisinin production was found with 10 mg l-1 gibberellic acid, 0.5 g l-1 casein hydrolysate, 10 mg l-1 or 20 mg l-1 naftifine. Relative increases of 154%, 169%, 140% and 120% were found, respectively. Other additions caused the growth to cease and the artemisinin contents to drop.Abbreviations BAP
benzylaminopurine
- DW
dry weight
- FW
fresh weight
- GA3
gibberellic acid
- MS
Murashige & Skoog basal medium
- NAA
naphthaleneacetic acid 相似文献
44.
Preciado-Patt Liana Cahalon Liora Hershkovitz Rami Lider Ofer Pras Mordechai Fridkin Mati 《International journal of peptide research and therapeutics》1998,5(5-6):349-355
Summary Serum amyloid A (SAA), an acute-phase reactant, exists naturally as a minor protein in the sera of healthy individuals. However,
its levels in sera are increased markedly during various transient and chronic inflammatory diseases, often concomitantly
with accumulation at inflicted sites. SAA is synthesized mainly in the liver following the synergistic action of cytokines,
mainly tumor necrosis factor-α (TNF-α) and interleukin-1 and-6 (IL-1 and IL-6). It was already shown by us that upon interaction
with SAA or amyloid A (AA), the extracellular matrix (ECM) and laminin induced the adhesion of resting human CD4+ T-cells in an apparently β1-integrin-mediated manner. Herein we have shown that the SAA-ECM complex modulates the regulation of cytokine synthesis by
human T-lymphocytes. The SAA-ECM complex dramatically enhanced the release of TNF-α by human T-cells in a dose-dependent manner,
reaching its maximal effect in the presence of 100 μM recombinant SAA. The SAA domain, responsible for the enhanced release
of TNF-α by human T-lymphocytes, is apparently the amyloid A protein (AA, i.e. SAA2-82). Specifically, TNF-α enhanced secretion
is mediated through intimate interactions of SAA/AA, with laminin. Thus, the ECM serving as a temporary anchorage site for
SAA and AA seems to be involved in regulating TNF-α secretion and the recruitment and accumulation of immunocytes in extravascular,
inflammatory compartments. 相似文献
45.
Linkage disequilibrium mapping places the gene causing familial Mediterranean fever close to D16S246. 总被引:2,自引:2,他引:0 下载免费PDF全文
E. N. Levy Y. Shen A. Kupelian L. Kruglyak I. Aksentijevich E. Pras J. E. Balow Jr B. Linzer X. Chen D. A. Shelton D. Gumucio M. Pras M. Shohat J. I. Rotter N. Fischel-Ghodsian R. I. Richards D. L. Kastner 《American journal of human genetics》1996,58(3):523-534
This report presents refined genetic mapping data for the gene causing familial Mediterranean fever (FMF), a recessively inherited disorder of inflammation. We sampled 65 Jewish, Armenian, and Arab families and typed them for eight markers from chromosome 16p. Using a new algorithm that permits multipoint calculations for a dense map of markers in consanguineous families, we obtained a maximal LOD score of 49.2 at a location 1.6 cM centromeric to D16S246. A specific haplotype at D16S283-D16S94-D16S246 was found in 76% of Moroccan and 32% of non-Moroccan Jewish carrier chromosomes, but this haplotype was not overrepresented in Armenian or Arab FMF carriers. Moreover, the 2.5-kb allele at D16S246 was significantly associated with FMF in Moroccan and non-Moroccan Jews but not in Armenians or Arabs. Since the Moroccan Jewish community represents a relatively recently established and genetically isolated founder population, we analyzed the Moroccan linkage-disequilibrium data by using Luria-Delbrück formulas and simulations based on a Poisson branching process. These methods place the FMF susceptibility gene within 0.305 cM of D16S246 (2-LOD-unit range 0.02-0.64 cM). 相似文献
46.
On the improvement of the podophyllotoxin production by phenylpropanoid precursor feeding to cell cultures of Podophyllum hexandrum Royle 总被引:2,自引:0,他引:2
In order to improve the production of the cytotoxic lignan podophyllotoxin, seven precursors from the phenylpropanoid-routing and one related compound were fed to cell suspension cultures derived from the rhizomes of Podophyllum hexandrum Royle. These cell cultures were able to convert only coniferin into podophyllotoxin, maximally a 12.8 fold increase in content was found. Permeabilization using isopropanol, in combination with coniferin as a substrate, did not result in an extra increase in podophyllotoxin accumulation. Concentrations of isopropanol exceeding 0.5% (v/v) were found to be rather toxic for suspension growth cells of P. hexandrum. When coniferin was fed in presence of such isopropanol concentrations, -glucosidase activity was still present, resulting in the formation of the aglucon coniferyl alcohol. In addition, podophyllotoxin was released into the medium under these permeabilization conditions. Entrapment of P. hexandrum cells in calcium-alginate as such or in combination with the feeding of biosynthetic precursors, did not improve the podophyllotoxin production. Cell-free medium from suspension cultures at later growth stages incubated with coniferin, resulted in the synthesis of the lignan pinoresinol. 相似文献
47.
Iwata M Cowling RT Gurantz D Moore C Zhang S Yuan JX Greenberg BH 《American journal of physiology. Heart and circulatory physiology》2005,289(6):H2356-H2363
ANG-(1-7) improves the function of the remodeling heart. Although this peptide is generated directly within the myocardium, the effects of ANG-(1-7) on cardiac fibroblasts that play a critical role in cardiac remodeling are largely unknown. We tested the hypothesis that specific binding of ANG-(1-7) to cardiac fibroblasts regulates cellular functions that are involved in cardiac remodeling. 125I-labeled ANG-(1-7) binding assays identified specific binding sites of ANG-(1-7) on adult rat cardiac fibroblasts (ARCFs) with an affinity of 11.3 nM and a density of 131 fmol/mg protein. At nanomolar concentrations, ANG-(1-7) interacted with specific sites that were distinct from ANG II type 1 and type 2 receptors without increasing cytosolic Ca2+ concentration. At these concentrations, ANG-(1-7) had inhibitory effects on collagen synthesis as assessed by [3H]proline incorporation and decreased mRNA expression of growth factors in ARCFs. These effects of ANG-(1-7) contrasted with effects of ANG II. Pretreatment of ARCFs with ANG-(1-7) inhibited ANG II-induced increases in collagen synthesis and in mRNA expression of growth factors, including endothelin-1 and leukemia inhibitory factor. ANG-(1-7) pretreatment also inhibited the stimulatory effects of conditioned medium from ANG II-treated ARCFs on [3H]leucine incorporation and atrial natriuretic factor mRNA expression, markers of hypertrophy, in cardiomyocytes. Thus ANG-(1-7) interacted with specific receptors on ARCFs to exert potential antifibrotic and antitrophic effects that could reverse ANG II effects. These results suggest that ANG-(1-7) may play an important role in the heart in regulating cardiac remodeling. 相似文献
48.
49.
Summary Podophyllotoxin was produced by cell cultures derived from needles of Callitris drummondii. The needles of this conifer contained 1.56% podophyllotoxin on a dry weight basis, 32% being present in the -glucosidic form. Trace amounts of desoxypodophyllotoxin and matairesinol were also detected. In dark-grown cell cultures, ca. 0.02 % podophyllotoxin was accumulated, 85–90 % in the -D-glucosidic form. Moreover, traces of the lignans matairesinol, hinokinin and asarinin were detected. Illumination stimulated the endogenous production of podophyllotoxin--D-glucoside; contents of up to 0.11 % could be measured. 相似文献
50.
The significance of mucopolysaccharides in amyloid 总被引:1,自引:0,他引:1
M Pras Z Nevo M Schubert J Rotman R Matalon 《The journal of histochemistry and cytochemistry》1971,19(7):443-448