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201.
Glutamine synthetase localization in cortisol-induced chick embryo retinas 总被引:1,自引:0,他引:1
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We report here for the first time, in chick retina, Muller cell localization of glutamine synthetase (GS) activity by an immunohistochemical technique, in agreement with previous reports of glial localization of this enzyme in rat brain and retina. Age-dependent changes in the endogenous enzyme activity as well as cortisol-induced changes in GS activity, both in ovo and in vitro, measured biochemically, reflect the changes observed by staining. 相似文献
202.
Highly pure lysosomes were isolated from buffalo(Bubalus bubalis) kidney cortex by a procedure involving differential and isopycnic Percoll density gradient centrifugations. Arylsulphatase,
N-acetyl-Β-glucosamindase and cathepsin D in the lysosomal preparation were 26–45-fold enriched over the homogenate. The purified
lysosomes contained less than 0·06% of mitochondrial, microsomal and peroxisomal marker enzymes. In the electron micrographs
the particles appeared as large dense granules of size 0·3-1·9 μm with no apparent structural features belonging to mitochondria
or microsomes. The isolation procedure was also found to be suitable to obtain highly pure lysosome particles from renal cortex
of other sources such as rat, lamb and beef. No ultracentrifugation steps were involved in the procedure 相似文献
203.
Blood flow to the testis, measured by the133-Xenon isotope clearance technique, initially increased after rams were exposed to elevated (32°C) temperature. However, after 5 and 7 days continuous exposure, blood flow decreased significantly. Similar changes in blood flow to the testis were found during whole body exposure to elevated temperature, or when the temperature of the testis was increased by scrotal heating. After one week of heating the wall of the spermatic artery in the middle region of the pampiniform plexus had thickened, and the arterial lumen had decreased significantly. The PGF
2
content in the testis of rams exposed to elevated temperature increased significantly. It is tentatively postulated that the higher levels of PGF
2
in the testis of rams exposed to elevated temperature may be responsible for impaired spermatogenic function by constricting the spermatic artery in the pampiniform plexus region and thereby reducing blood flow to the testis.Published with approval of the Director of Kentucky Agricultural Experiment Station as Journal Article 75-5-150.Presented at the Seventh International Biometeorological Congres, 17–23 August 1975. College Park, Maryland, U.S.A. 相似文献
204.
M K Dutt 《Folia histochemica et cytochemica》1978,16(3):241-246
Acid hydrolysed DNA of rat liver was stained with Schiff's reagent at pHs 1.7 or 3.0 followed by staining with acriflavine-SO2 at pH 2.0 as well as with acriflavine-SO2 followed by Schiff's reagent at pH 1.7 or 3.0. Nuclei stained with Schiff's reagent at pH 1.7 were brown-yellow and an analysis of their absorption characteristics revealed two peaks--one at 470 nm and the other at 570 nm. Although nuclei stained with Schiff's reagent at pH 3.0 followed by acriflavine-SO2 were deep magenta in colour, they also showed similar peaks of maximum absorption. Identical peaks were also seen when the sequence of staining was reversed. It is suggested that in the conventional Feulgen-type reactions only some of the DNA-aldehyde molecules are stained; the remaining molecules can be stained by sequential application of another Schiff or Schiff-type reagent such as acriflavine-SO2. The possible mechanism of staining in these cases has been discussed. 相似文献
205.
206.
Zhijian T. Li S. A. Dhekney M. Dutt D. J. Gray 《Plant Cell, Tissue and Organ Culture》2008,93(3):311-321
An improved protocol for efficient Agrobacterium-mediated transformation of grapevine (Vitis sp.) was developed through modification of cocultivation and subsequent washing procedures. It was determined that Agrobacterium-infected somatic embryos (SE) cocultivated on filter paper exhibited less browning and significantly higher transient GFP
and GUS expression than those cultured on agar-solidified medium. Furthermore, such SE, when subjected to a prolonged washing
period in liquid medium containing cefotaxime and carbenicillin, followed by another wash in similar medium with kanamycin
added, exhibited significantly higher rates of stable transformation compared to previously-described procedures. Transgenic
plant recovery was increased 3.5–6 Xs by careful excision of leafy cotyledons from SE that had been induced to germinate on
MS medium containing 1 μM of BA. Southern blot analysis revealed the low copy number integration of transgenes in transgenic
plants recovered using the improved protocol. These improved cocultivation and plant recovery procedures have been demonstrated
to facilitate production of large populations of transgenic plants from V. vinifera ‘Merlot’, ‘Shiraz’ and ‘Thompson Seedless’ as well as Vitis hybrid ‘Seyval Blanc’. 相似文献
207.
Cheese whey was the most suitable substrate for production of lactic acid under anaerobic conditions by Entercoccus flavescens which, on supplementating with corn steep liquor (5% v/v) and 10 mM CaCO3 at pH 5.5, 37°C, yielded 12.6 g lactic acid/l in 36 h. Production was scaled up to a 10 l bioreactor under controlled pH
and continuous CO2 supply and gave 28 g lactic acid/l in 30 h resulting in a net 8.7-fold increase in production as compared to unoptimized
conditions. 相似文献
208.
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210.
A method to produce transgenic plants of Vitis rotundifolia was developed. Embryogenic cultures were initiated from leaves of in vitro grown shoot cultures and used as target tissues
for Agrobacterium-mediated genetic transformation. A green fluorescent protein/neomycin phosphotransferase II (gfp/nptII) fusion gene that allowed for simultaneous selection of transgenic cells based on GFP fluorescence and kanamycin resistance
was used to optimize parameters influencing genetic transformation. It was determined that both proembryonal masses (PEM)
and mid-cotyledonary stage somatic embryos (SE) were suitable target tissues for co-cultivation with Agrobacterium as evidenced by transient GFP expression. Kanamycin at 100 mg l−1 in the culture medium was effective in suppression of non-transformed tissue and permitting the growth and development of
transgenic cells, compared to 50 or 75 mg l−1, which permitted the proliferation of more non-transformed cells. Transgenic plants of “Alachua” and “Carlos” were recovered
after secondary somatic embryogenesis from primary SE explants co-cultivated with Agrobacterium. The presence and stable integration of transgenes in transgenic plants was confirmed by PCR and Southern blot hybridization.
Transgenic plants exhibited uniform GFP expression in cells of all plant tissues and organs including leaves, stems, roots,
inflorescences and the embryo and endosperm of developing berries. 相似文献