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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The analgesic activity of methanol extract of Cleome viscosa, given orally at the doses of 100, 200, 400 mg/kg was evaluated for its analgesic activity in mice using the acetic acid-induced writhing and the tail flick, tail clip, tail immersion methods. The extract showed promising activity in all the tests. 相似文献
992.
Embelin, a benzoquinone-derivative isolated from Embelia ribes, when tested for its antibacterial potential exhibited significant inhibition against five and moderate activity against three strains of the 12 bacteria tested. 相似文献
993.
Extracts from the stem bark of Streblus asper possess insecticidal activity against the fifth instar of Dysdercus cingulatus. Methanolic extract showed an LC(50) value of 5.56 microg/insect. Partition with chloroform increased the insecticidal activity (LC(50) 2.01 microg/insect). Three polyphenolic rich fractions were obtained from silica-gel column chromatography of the chloroform fraction and found to have noteworthy insecticidal activity (LC(50): 1.82 microg, 2.70 microg, 2.26 microg/insect) by topical application. This may provide a useful beginning for the development of biopesticides. 相似文献
994.
995.
We compared seasonal changes in maximum diurnal trunk shrinkage (MDS) with seasonal changes in midday stem water potential (Psi(s)) over three years in plum trees grown in differing drip-irrigated regimes. In well-irrigated trees, day-to-day variations in Psi(s) and MDS were related to evaporative demand. Reference equations were obtained to predict MDS and Psi(s) values for well-irrigated trees as functions of environmental conditions. A decrease in plant water status toward the end of the growing season occurred even in the well-irrigated trees, probably reflecting a reduced volume of soil wetted by the drip irrigation system. Thus, for the prediction of Psi(s), different reference equations are required for the fruit-growth and after-harvest phenological periods. A seasonal change in the relationship between MDS and Psi(s) was observed, which compensated for the decrease in plant water status such that well-irrigated trees had similar MDS values during both the fruit-growth and after-harvest periods. The influence of tree size on the relationship between MDS and Psi(s) was also investigated. For tree trunk diameters ranging between 8 and 13 cm, MDS increased 13% for each cm of increase in trunk diameter, as a result of the thicker phloem tissues of the larger trees. This finding may allow extrapolation of Psi(s) predictions based on empirical relationships with MDS to plum trees of different sizes. 相似文献
996.
Variation of heartrot,sapwood infection and polyphenol extractives with provenance of Acacia mangium
K. M. Barry R. S. B. Irianto B. Tjahjono M. Tarigan L. Agustini E. B. Hardiyanto C. L. Mohammed 《Forest Pathology》2006,36(3):183-197
Infection of heartwood by decay fungi (heartrot) is a concern for growers of Acacia mangium for solid‐wood products as the incidence can be high in some regions of Indonesia. Variation of heartrot incidence for different provenances of A. mangium was determined using two field trials in Sumatra, Indonesia. In a Riau Province trial of 21 provenances, the effect of provenance was statistically significant for natural heartrot incidence, which ranged from 1.6% to 27.2%. In a smaller trial using artificial inoculation in South Sumatra, heartwood infection incidence ranged from 39.4% to 70.8% across six provenances and both wound type and provenance were statistically significant factors. There was also significant variation in sapwood infection length related to provenance. Wood extractives (yield, total phenols, protein‐precipitable tannin and 2,3‐trans‐3,4′,7,8‐tetrahydroxyflavanone) were quantified from a subsample of trees for each trial. However, no significant differences in extractive concentration were detectable according to provenance and evidence for a relationship between heartwood extractives and heartrot incidence was generally poor. While further studies need to be completed to establish the basis for heartrot incidence, results from these trials allow for recommendations on provenance selection to reduce heartrot incidence and provide information for further genetic selection programmes. 相似文献
997.
Improvement in seed and seedling quality of Acacia auriculiformis after culling phenotypically inferior trees was studied
in a 6-year old seed production area (SPA). A 5-ha plantation was identified, of which 2.3 ha was converted into SPA. The
initial stocking, 1 612 trees·ha−1, was thinned down to 982 trees·ha−1 based on growth characteristics. The following fruiting season, seeds were collected from 10 randomly selected trees in culled
and non-culled stands, and seed physical characters, germination and seedling traits were assessed. Seed weight, seed thickness
and percentage germination increased by 32.1%, 4.43% and 22.37%, respectively in the culled stand compared to the non-culled
stand. Culling also increased the speed of germination, seedling dry weight and seedling vigor index. Heritability values
were high for seed weight (0.974) and seed thickness (0.948) while medium values were observed for percentage germination
(0.577) and total dry weight (0.534). Predicted genetic gain was 11.13% and 11.22% for seed weight and percentage germination,
respectively. The actual gain was 32.1, 51.9 and 22.9% for seed weight, percentage germination and total dry matter, respectively.
In conclusion, SPAs established by culling inferior trees could serve as sources of good quality seeds for reforestation programs
until genetically improved seeds are made available. 相似文献
998.
Abdelwahab SI Hassan LE Sirat HM Yagi SM Koko WS Mohan S Taha MM Ahmad S Chuen CS Narrima P Rais MM Hadi AH 《Fitoterapia》2011,82(8):1190-1197
The in vivo and in vitro mechanistic anti-inflammatory actions of cucurbitacin E (CE) (Citrullus lanatus var. citroides) were examined. The results showed that LPS/INF-γ increased NO production in RAW264.7 macrophages, whereas L-NAME and CE curtailed it. CE did not reveal any cytotoxicity on RAW264.7 and WRL-68 cells. CE inhibited both COX enzymes with more selectivity toward COX-2. Intraperitoneal injection of CE significantly suppressed carrageenan-induced rat's paw edema. ORAC and FRAP assays showed that CE is not a potent ROS scavenger. It could be concluded that CE is potentially useful in treating inflammation through the inhibition of COX and RNS but not ROS. 相似文献
999.
Maggi F Barboni L Caprioli G Papa F Ricciutelli M Sagratini G Vittori S 《Fitoterapia》2011,82(8):1215-1221
Coumarin occurs in many plants used as flavoring and is known to possess hepatotoxic effects. Despite in the EFSA ‘Compendium of botanicals containing toxic substances’ coumarin is reported to be present in Melittis melissophyllum (bastard balm), a plant traditionally used as beverage in Italy and Serbia, to the best of our knowledge quantitative data has never been reported. Thus, the amount of coumarin in bastard balm leaves and its variation during the annual phenological cycle were determined. The subsp. melissophyllum resulted to contain high levels of coumarin (14,392 mg/kg), mainly in the early stages of the plant cycle, suggesting prudence in its use as beverage. Furthermore, coumarin was found to be useful as marker compound to differentiate the bastard balm subspecies occurring in Italy, since the subsp. albida contained a much lower content of this molecule (19–34 mg/kg). 相似文献
1000.