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71.
Spatial and temporal expression patterns of the sorghum SBEI, SBEIIA and SBEIIB genes, encoding, respectively, starch branching enzyme (SBE) I, IIA and IIB, in the developing endosperm of sorghum (Sorghum bicolor) were studied. Full-length genomic and cDNA clones for sorghum were cloned, and the SBEIIA cDNA was used together with gene-specific probes for sorghum SBEIIB and SBEI. In contrast to sorghum SBEIIB, which was expressed primarily in endosperm and embryo, SBEIIA was also expressed in vegetative tissues. All three genes shared a similar temporal expression profile during endosperm development, with a maximum activity at 15-24 d after pollination. This differed from barley and maize, in which SBEI gene activity showed a significantly later onset compared to that of SBEIIA and SBEIIB. Expression of the three SBE genes in the sorghum endosperm exhibited a diurnal rhythm during a 24-h cycle. 相似文献
72.
Benjamin Steinitz Yona Tabib Victor Gaba Tanya Gefen Yiftach Vaknin 《In vitro cellular & developmental biology. Plant》2009,45(1):65-71
Efficient vegetative cloning in vitro requires definition of plant growth regulator regimes for each genotype, and therefore formulation of a uniform culture protocol
for a genetically heterogeneous wild or uncultivated plant population is often impossible. The likelihood of cloning a wide
array of plant genotypes by avoiding the use of plant growth regulator(s) was explored with Moringa oleifera Lamk., Moringa stenopetala (Baker f.) Cufod, and Moringa peregrina Forssk. ex Fiori tree seedlings. Propagation was achieved by multiple shoot regeneration from the cotyledonary node of decapitated
seedlings, followed by axillary shoot growth from single node shoot segments and rooting of excised shoots. All steps were
accomplished on basal Murashige and Skoog medium without plant growth regulator supplements. The results revealed competence
for generation of multiple shoots from cotyledonary node tissue, stimulated by repeated shoot harvest, in seedlings of all
three tree species. Tens of plants per seedling were regenerated in about 4 mo from culture initiation. In a given species
clone size was seedling-dependent, which presumably stems from genotypic variability among seedlings in regeneration ability
in vitro. By this means the laborious search for a plant growth regulator regime suitable for organogenesis induction and adapted
per genotype became redundant, and biodiversity of the seed germplasm could be maintained. The approach ideally suits establishment
of clones of wild plants of endangered species, like those of the Moringaceae, species with high ability for producing supplementary
shoots, and without the need to add plant growth regulators, including the rooting stage. 相似文献
73.
Elvira Vitu Sunghwan Kim Carolyn S. Sevier Omer Lutzky Nimrod Heldman Moran Bentzur Tamar Unger Meital Yona Chris A. Kaiser Deborah Fass 《The Journal of biological chemistry》2010,285(24):18155-18165
The sulfhydryl oxidase Ero1 oxidizes protein disulfide isomerase (PDI), which in turn catalyzes disulfide formation in proteins folding in the endoplasmic reticulum (ER). The extent to which other members of the PDI family are oxidized by Ero1 and thus contribute to net disulfide formation in the ER has been an open question. The yeast ER contains four PDI family proteins with at least one potential redox-active cysteine pair. We monitored the direct oxidation of each redox-active site in these proteins by yeast Ero1p in vitro. In this study, we found that the Pdi1p amino-terminal domain was oxidized most rapidly compared with the other oxidoreductase active sites tested, including the Pdi1p carboxyl-terminal domain. This observation is consistent with experiments conducted in yeast cells. In particular, the amino-terminal domain of Pdi1p preferentially formed mixed disulfides with Ero1p in vivo, and we observed synthetic lethality between a temperature-sensitive Ero1p variant and mutant Pdi1p lacking the amino-terminal active-site disulfide. Thus, the amino-terminal domain of yeast Pdi1p is on a preferred pathway for oxidizing the ER thiol pool. Overall, our results provide a rank order for the tendency of yeast ER oxidoreductases to acquire disulfides from Ero1p. 相似文献
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77.
Ido Laish Hila Katz Yael Sulayev Meytal Liberman Timna Naftali Fabiana Benjaminov Assaf Stein Yona Kitay-Cohen Tal Biron-Shental Fred Konikoff Aliza Amiel 《Gene》2013
Objective
Primary sclerosing cholangitis (PSC) is a chronic cholestatic disorder that involves inflammatory and fibrotic changes in the bile ducts. Up to 80% of patients have concomitant inflammatory bowel disease (IBD) with colitis. PSC patients are predisposed to develop hepatobiliary, colonic and other extrahepatic malignancies, probably related to inflammatory processes that might promote carcinogenesis. Telomerase is an enzyme complex that lengthens telomeres and has enhanced expression in numerous malignancies. In this study, we evaluated the TERC gene copy number, the proportion of cells in senescence and the amount of fragmentation in the senescent state.Methods
Fluorescence in situ hybridization (FISH) for the TERC gene was applied to lymphocytes retrieved from PSC (N = 19), colitis (N = 20) and healthy control patients (N = 20) to determine the TERC copy number. On the same FISH slides, cells stained with DAPI were also analyzed for senescence-associated heterochromatin foci (SAHF) status, including the number of cells with fragments and the number of SAHF fragments in each cell.Results
A higher TERC gene copy number was observed in cells from PSC patients compared to colitis and control group patients. It was also higher in the colitis than in the control group. Significantly more cells in the senescent state and more fragmentation in each cell were observed in the PSC group compared to colitis and control groups.Conclusion
The TERC gene copy number and the number of cells in the senescent state were increased in PSC patients compared to the colitis and control groups. These findings are probably related to the genetic instability parameters that reflect the higher tendency of this patient group to develop malignancies. 相似文献78.
Israel I.E. Ashkenazi Sr Rachel R. Carlebach Yona Y. Kitay-Cohen Alexander A. Zvulunovah L. Le Peleg 《Biological Rhythm Research》2013,44(3):286-292
Four groups of mice were injected with vincristine, each at a different time, for ten successive days. Mortality and daily pattern of peripheral white blood cells (WBC) count were monitored immediately and at various times after the last injection. The results demonstrated that (1) drug administration time dependency was observed in rate of death, recorded for 80 days following the injections; (2) the time of drug administration affected the parameters of WBC count rhythm, and (3) there were differences between immediate effects upon the rhythm parameters (monitored one day after the last injection) to those measured at succeeding times (on days 8 and 15 after injections cessation). The results emphasize the need to consider continuous post administration rhythm changes, especially when scheduling repeated chronotherapeutics, where variables which serve for toxicity-diagnosis are rhythmic in nature. 相似文献
79.
Microbial activity and organic matter dynamics during 4 years of irrigation with treated wastewater 总被引:1,自引:0,他引:1
Elifantz H Kautsky L Mor-Yosef M Tarchitzky J Bar-Tal A Chen Y Minz D 《Microbial ecology》2011,62(4):973-981
The global changes in rainfall frequency and quantity have subjected arid and semi-arid regions to long periods of drought.
As this phenomenon corresponds to increasing trend of water shortage, the use of treated wastewater (TWW) has been suggested
as an alternative for irrigation of agricultural crops in these areas. The aim of the study was to investigate the short-
and middle-term effects of TWW irrigation on the soil microbial activities and organic carbon content. The microbial community
activity was measured every 1–3 months for 4 years in a persimmon (Diospyros kaki) orchard. These activities were used here as an indicator for the soil health. The hydrolysis activity (detected by fluorescein
diacetate hydrolysis (FDA) assay) increased during the irrigation season and was significantly higher in soils irrigated with
TWW compared to those irrigated with freshwater (FW). This activity was also negatively correlated with dissolved organic
carbon (DOC) concentrations during the irrigation season, suggesting that the community degraded the DOC in the soils regardless
of its origin. The irrigation season was also characterized by an increase in nitrification potential in both TWW- and FW-irrigated
soils, which coincided with high concentrations of nitrate (50 mg kg−1 soil). Overall, there was an increase in all measured activities during the irrigation season, and they were higher in the
TWW soils. However, it appears that after each irrigation season, the potential activity of the community returned to levels
similar to or even slightly lower than those of FW-irrigated soil during the wet season, suggesting that the periodic irrigation
did not significantly change the soil microbial activity. 相似文献
80.
Mice are exceedingly sensitive to intra-peritoneal (IP) challenge with some virulent pneumococci (LD50 = 1 bacterium). To investigate how peripheral contact with bacterial capsular polysaccharide (PS) antigen can induce resistance, we pulsed bone marrow dendritic cells (BMDC) of C57BL/6 mice with type 4 or type 3 PS, injected the BMDC intra-foot pad (IFP) and challenged the mice IP with supra-lethal doses of pneumococci. We examined the responses of T cells and B cells in the draining popliteal lymph node and measured the effects on the bacteria in the peritoneum and blood. We now report that: 1) The PS co-localized with MHC molecules on the BMDC surface; 2) PS-specific T and B cell proliferation and IFNγ secretion was detected in the draining popliteal lymph nodes on day 4; 3) Type-specific resistance to lethal IP challenge was manifested only after day 5; 4) Type-specific IgM and IgG antibodies were detected in the sera of only some of the mice, but B cells were essential for resistance; 5) Control mice vaccinated with a single injection of soluble PS did not develop a response in the draining popliteal lymph node and were not protected; 6) Mice injected with unpulsed BMDC also did not resist challenge: In unprotected mice, pneumococci entered the blood shortly after IP inoculation and multiplied exponentially in both blood and peritoneum killing the mice within 20 hours. Mice vaccinated with PS-pulsed BMDC trapped the bacteria in the peritoneum. The trapped bacteria proliferated exponentially IP, but died suddenly at 18-20 hours. Thus, a single injection of PS antigen associated with intact BMDC is a more effective vaccine than the soluble PS alone. This model system provides a platform for studying novel aspects of PS-targeted vaccination. 相似文献