全文获取类型
收费全文 | 120篇 |
免费 | 6篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 3篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1959年 | 5篇 |
1958年 | 14篇 |
1957年 | 4篇 |
1956年 | 5篇 |
1955年 | 5篇 |
1954年 | 1篇 |
1953年 | 2篇 |
1952年 | 4篇 |
排序方式: 共有126条查询结果,搜索用时 531 毫秒
91.
Fuminori ITO 《Entomological Science》2010,13(2):199-204
Queen‐worker dimorphism, worker polymorphism and worker behavior in the Oriental amblyoponine ant Myopopone castanea were studied. Queen body size was large (head width, 3.0 mm) with 24 to 32 ovarioles while workers showed a remarkable size variation in both body size (head width 1.48 to 2.18 mm) and ovariole number (6 to 22). Both head width and abdomen width showed allometric growth against thorax width. Workers performed larval hemolymph feeding as was described for Amblyopone silvestrii queens. 相似文献
92.
93.
Histone modification and signalling cascade of the dormancy‐associated MADS‐box gene,PpMADS13‐1, in Japanese pear (Pyrus pyrifolia) during endodormancy 下载免费PDF全文
TAKANORI SAITO SONGLING BAI TSUYOSHI IMAI AKIKO ITO IKUKO NAKAJIMA TAKAYA MORIGUCHI 《Plant, cell & environment》2015,38(6):1157-1166
Dormancy‐associated MADS‐box (DAM) genes play an important role in endodormancy phase transition. We investigated histone modification in the DAM homolog (PpMADS13‐1) from Japanese pear, via chromatin immunoprecipitation–quantitative PCR, to understand the mechanism behind the reduced expression of the PpMADS13‐1 gene towards endodormancy release. Our results indicated that the reduction in the active histone mark by trimethylation of the histone H3 tail at lysine 4 contributed to the reduction of PpMADS13‐1 expression towards endodormancy release. In contrast, the inactive histone mark by trimethylation of the histone H3 tail at lysine 27 in PpMADS13‐1 locus was quite low, and these levels were more similar to a negative control [normal mouse immunoglobulin G (IgG)] than to a positive control (AGAMOUS) in endodormancy phase transition. The loss of histone variant H2A.Z also coincided with the down‐regulation of PpMADS13‐1. Subsequently, we investigated the PpMADS13‐1 signalling cascade and found that PpCBF2, a pear C‐repeated binding factor, regulated PpMADS13‐1 expression via interaction of PpCBF2 with the 5′‐upstream region of PpMADS13‐1 by transient reporter assay. Furthermore, transient reporter assay confirmed no interaction between the PpMADS13‐1 protein and the pear FLOWERING LOCUS T genes. Taken together, our results enhance understanding of the molecular mechanisms underlying endodormancy phase transition in Japanese pear. 相似文献
94.
The effect of exposure of kidney bean primary leaves to NO2and O3, alone or in combination, on the fate of 13CO2 assimilatedby photosynthesis was examined by 13C-NMR. There were more than70 peaks appearing in the 13C-NMR spectra for substances extractedfrom leaves with 80% ethanol. The 16 relatively well resolvedpeaks corresponded to signals from three sugars, two organicacids and four amino acids. These signals were used to estimatepool sizes and l3C incorporation. Exposures to NO2 and O3 increased the amounts of sucrose andfructose, but not the incorporation of the 13C label during10 min photosynthesis from 13CO2. This suggests the presenceof photo-synthetically inactive pools of sucrose and fructose.Amounts of glycine and serine, and 13C incorporation into them,were increased by the exposure to the pollutants. The incorporationof 13C into alanine was stimulated by exposure to NO2, but notby exposure to O3 alone. The present study shows that with only simple procedures ofsample preparations 13C-NMR provides information on the productsof photosynthesis in leaves stressed by the two air pollutants. Key words: NO2, O3, Phaseolus vulgaris, CO2 assimilation, 13C-NMR 相似文献
95.
Effects of Microinjected Cations on the Early Event of Fertilization in the Medaka Egg 总被引:3,自引:3,他引:0
Effects of microinjected cations on the early events of fertilization were examined using eggs of Oryzias latipes . Microinjection of either Ca2+ , Ba2+ or Sr2+ into the thin cortical cytoplasm induced breakdown of cortical alveoli (vesicles) (CABD) under Ca-Mg-free conditions, but microinjection of Mg2+ , Mn2+ or Co2+ prevented CABD at the injected region when the eggs were inseminated in regular saline. Under Ca-Mg-free conditions, CABD could also be induced by microinjection of various solutions (NaCl, choline chloride, sucrose, pH buffer) without any divalent cations or ionophore A23187. Ca2+ microinjected into the cortical cytoplasm did not play a role in sperm penetration. Upon microinjection with either Ca2+ , Mg2+ or K+ , the resting membrane potential leakage was transiently observed. However, depolarization of the membrane followed by slow hyperpolarization was observed only upon microinjection of Ca2+ . From these experiments, it was inferred that microinjected divalent cations such as Ca2+ , Ba2+ or Sr2+ do not act directly upon the cortical alveolus membrane, but trigger the induction of CABD via depolarization of the membrne and increase in intracellular Ca2+ . 相似文献
96.
YOSHIHIRO ITO MASATO FURUYA MIKIO OKA HUMIO OSAKI MASAMICHI AIKAWA 《The Journal of eukaryotic microbiology》1981,28(3):313-316
The structure of micronemata arising from the surface of the bloodstream form of Trypanosoma gambiense was studied by electron microscopy. In order to produce micronemata, trypanosomes were incubated in either 1) phosphate buffered saline supplemented with glucose (PBSG), 2) immune mouse serum or 3) PBSG after passage through a DEAE-cellulose column. Electron microscopic examination of the parasite revealed the presence of thread-like micronemata arising from the anterior end and from the flagellar pocket regardless of the incubation conditions. Negative staining revealed a distinct peripheral fringe layer with nodular protrusions covering the entire surface of the micronema. The distribution and number of intramembrane particles (IMP) on the P and E faces of the micronema were similar to those of the flagellum of T. gambiense, indicating a close relationship between the membrane structure of the micronema and the flagellum. Micronemata became fragmented and adhered to each other after incubation of the parasite in the media for 12 h. Since micronemata tend to have the characteristics of adhesiveness and fragmentation, fragments of these structures might adhere to various host organs. Dispersal of potential antigenic material might be responsible, in part, for the induction of the host immune response. 相似文献
97.
98.
EDUARD B. VSEVOLODOV SHOSUKE ITO KAZUMASA WAKAMATSU IRINA I. KUCHINA IGOR F. LATYPOV 《Pigment cell & melanoma research》1991,4(1):30-34
Eighteen hair samples from Karakul newborn lambs with various colors were estimated for eumelanin and pheomelanin contents (Ce and Cp, respectively) by electron spin resonance (ESR) spectrometry and by high-performance liquid chromatography (HPLC). Correlation coefficients between the values estimated by the ESR and HPLC methods were 0.96, 0.93, and 0.99 for Ce, Cp, and Ce/Cp, respectively. The high correlation coefficients show that both methods fit well for estimation of relative values of these parameters. The absolute values of Ce and Ce/Cp coincide rather well when Ce is high, but considerable discrepancies appear when Ce is low. The reasons for these discrepancies are discussed. The HPLC method appears to be more sensitive for detection of low concentrations of pheomelanin, while the ESR method fits well for mass selection purposes. 相似文献
99.
100.