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排序方式: 共有104条查询结果,搜索用时 450 毫秒
1.
LJ Lanzerotti K Rinnert G Dehmel FO Gliem EP Krider MA Uman J Bach 《Science (New York, N.Y.)》1996,272(5263):858-860
During the Galileo probe's descent through Jupiter's atmosphere, under the ionosphere, the lightning and radio emission detector measured radio frequency signals at levels significantly above the probe's electromagnetic noise. The signal strengths at 3 and 15 kilohertz were relatively large at the beginning of the descent, decreased with depth to a pressure level of about 5 bars, and then increased slowly until the end of the mission. The 15-kilohertz signals show arrival direction anisotropies. Measurements of radio frequency wave forms show that the probe passed through an atmospheric region that did not support lightning within at least 100 kilometers and more likely a few thousand kilometers of the descent trajectory. The apparent opacity of the jovian atmosphere increases sharply at pressures greater than about 4 bars. 相似文献
2.
Nikitin D. A. Ivanova E. A. Zhelezova A. D. Semenov M. V. Gadzhiumarov R. G. Tkhakakhova A. K. Chernov T. I. Ksenofontova N. A. Kutovaya O. V. 《Eurasian Soil Science》2020,53(12):1782-1793
Eurasian Soil Science - Quantitative characteristics of microbial communities in southern agrochernozems of the Stavropol region managed with the use of no-till technology and moldboard plowing... 相似文献
3.
It is unknown whether overlapping or sequential use of nonsteroidal anti‐inflammatory (NSAIDs) results in an increased risk for gastrointestinal (GI) ulceration. The purpose of this pilot study was to evaluate the GI effects of various combinations of an injectable NSAID followed by an oral NSAID, a scenario often employed clinically for management of the pre‐ and post‐operative canine patient. Six healthy Walker hounds received four treatment regimens in a randomized, cross‐over design with a 2 week washout period between each treatment week: carprofen (4 mg kg–1, SQ) followed by placebo (PO, q24 × 4 days); placebo (SQ) followed by deracoxib (3–4 mg kg–1, PO, q24 × 4 days); carprofen (4 mg kg–1, SQ) followed by carprofen (4 mg kg–1, PO, q24 × 4 days); carprofen (4 mg kg–1, SQ) followed by deracoxib (3–4 mg kg–1, PO, q24 ×4 days). Weekly bloodwork (CBC, biochemistry panel, fecal evaluation, fecal occult blood) and daily clinical scoring (TPR, vomiting, diarrhea, appetite) were obtained. GI endoscopy was performed on days –2, 1, 2, 5, and 11 days post treatment of each treatment period and lesions scored using a previously reported 6‐point scale. Data was analyzed using a mixed anova for repeated measures. There were no significant differences in clinical or clinicopathologic data between groups. Within the carprofen‐carprofen and carprofen‐deracoxib groups, lesions worsened by Day 5 (1 day after last oral dose) for the fundic and antral regions (p < 0.05). Fundic, antral and lesser curvature lesions improved by Day 5 in the carprofen‐placebo group and lesser curvature lesions improved in the placebo‐deracoxib group (p < 0.05). No significant within‐group differences were noted for the esophagus, cardia or duodenum. The small number of dogs precludes general conclusions about the safety of sequential NSAID use, but these results suggest that a larger scale study is warranted. 相似文献
4.
The methanol, petroleum ether, ethyl acetate and water-methanol extracts of Ruta graveolens were found to possess antimicrobial and cytotoxic activities. 相似文献
5.
6.
A. Yu. Avdeyev O. P. Kigashpaeva Yu. I. Avdeyev L. M. Ivanova 《Russian Agricultural Sciences》2014,40(2):96-99
The results of study of spontaneous fruit size and shape mutants and inheritance of these traits in tomato are given and genetic processes are explained. It is concluded that the diversity of tomato fruit shape and weight in the collection is due mainly to mutations of genes—diameter of fruit width and diameter of height joined into an ovate cluster. 相似文献
7.
Induced parthenogenesis as a possible method of haploidization in sunflower (H. annuus L.) was tested in previous investigations
(Todorova et al., 1994) and conditions for reproducible regeneration of gynogenic doubled haploids were established by the
present work. Forty eight treatments were studied, involving four pollen donors and four recipient hybrids. Pollen was irradiated
with doses of 300 Gy, 600 Gy and 900 Gy. In total, 2279 embryos were cultivated in vitro of which 1107 plants were obtained
and 582 of them produced seeds after selfing. The ploidy level of the regenerants was evaluated at the two – three leaf stage
and 296 of the plantlets obtained were haploids. Some of them underwent spontaneous diploidization, the others were treated
with colchicine solution for chromosome doubling. The diploid plantlets were checked for their gynogenic origin by genetical
and biochemical methods. The effectiveness of the method expressed as the number of agronomically useful DH lines to the number
obtained that were fertile and resistant to downy mildew, branched and unbranched plants was 8,6% on average.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
The occurrence of the two new cis-fused A/B rings furostanol saponins (25S)-26-O-β-d-glucopyranosyl-5β-furostan-1β,3β,22α,26-tetraol-1-O-β-d-glucopyranoside and (25S)-26-O-β-d-glucopyranosyl-5β-furostan-1β,2β,3β,5β,22α,26-hexaol and the known compounds (25S)-26-O-β-d-glucopyranosyl-5β-furostan-3β,22α,26-triol-3-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-β-d-glucopyranoside and (25S)-26-O-β-d-glucopyranosyl-5β-furostan-3β,22α,26-triol-3-O-β-d-glucopyranosyl-(1→2)-O-β-d-glucopyranoside, trans-resveratrol, (+) catechin and (−) epicatechin in the rhizomes of Smilax aspera is reported. All saponins have been isolated as their 22-OMe derivatives, which were further subjected to extensive spectroscopic analysis. The isolated furostanol saponins were evaluated for cytotoxic activity against human normal amniotic and human lung carcinoma cell lines using neutral red and MTT assays. In vitro experiments showed significant cytotoxicity in a dose dependent manner with IC50 values in the range of 32.98-94.53 µM. 相似文献
9.
M. I. Gulyukin N. G. Kozyreva L. A. Ivanova T. V. Stepanova I. A. Gulyukina 《Russian Agricultural Sciences》2016,42(6):472-475
Nucleotide sequence of a section of the Env 105 gene of bovine leukemia provirus isolates, obtained from farm animals in different regions of Russia, was determined. Conducted phylogenetic analysis has allowed us to assess heterogeneity of the studied population of the bovine leukemia virus (BLV). Based on results of BLV genetic diversity, four virus’s genotypes—I, II, IV, and VII with dominating genotype IV—were detected. 相似文献
10.
Carvalho RF Campos ML Pino LE Crestana SL Zsögön A Lima JE Benedito VA Peres LE 《Plant methods》2011,7(1):18-14