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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Malignant bone pain: pathophysiology and treatment 总被引:1,自引:0,他引:1
S Mercadante 《Canadian Metallurgical Quarterly》1997,69(1-2):1-18
2-acetyl aminofluorene (AAF) reacts in acidic conditions with nitrous fume yielding N-nitroso-AAF (N-NO-AAF), as previously described, that exerts more toxic and mutagenic effects than its parental compound. In this study, the effect of sodium nitrite (NaNO2) on the tumorigenicity of AAF in rats fed with AAF and NaNO2 was observed. Wistar rats were divided into five groups: group I served as control; group II were treated with NaNO2 (0.3%); group III was given 0.02% AAF alone; groups IV and V received both AAF and NaNO2 (0.2 and 0.3% respectively) in their diet for 12 weeks. At the end of the experiment, all rats in groups III, IV and V developed early stage phenomena of hepatocellular carcinoma, including hepatomegaly with variable-sized foci and neoplastic nodules. Severe damage was observed in the rats treated with AAF and NaNO2. Feeding of AAF (0.02%) for 3 months elevated the levels of c-Fos, c-Jun and c-Myc proteins in the rat livers. The AAF-induced c-Jun, c-Fos and c-Myc expressions were significantly magnified (P < 0.001) by NaNO2. These data confirmed that the strengthening of AAF-induced hepatocarcinogenesis by NaNO2 should be associated with its enhancing effect on the AAF-induced increases in the expressions of c-Jun, c-Fos and c-Myc. 相似文献
92.
A new commercially available diode model is described. This unified model is capable of simulating the widest range of diode technologies of any presently available. The emphasis of this paper is on describing the model's extensive features and flexibility in the different domains of operation and is of particular interest in power applications 相似文献
93.
V. I. Shtykov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1998,32(8):459-462
Conclusions 1. Use of dewatering systems based on voidless drainage is most effective when dewatering slightly permeable soils in regions
with a deep seasonal frost.
2. Two-story drainage with the upper and lower stories spaced 30 m apart accelerates the discharge of gravitational water
from the arable layer. Results of observations on two-story drainage in experimental-production sections indicated that it
discharges 2 – 3.8 times more water than systematic tubular drainage with an interdrain spacing of 10 m and a 0.2-m thick
three-dimensional filter of a sandy-gravelly mixture.
3. It is recommended to use crushed stone and porous-clay gravel with a fineness of 10 – 20 mm as a filler. In that case,
protection of the drain filler is, as a rule, required only from the intrusion of soil from above during construction in cohesive
soils with a plasticity indexW
p≥7.
4. seepage rate in a voidless drain should be lower than the scouring velocity for the soil in which the voidless drainage
is placed. In the opposite case, it is necessary to lower the grade of the drains or select a filler gradation such that the
seepage rate in the drain be lower than the scouring velocity.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 8, pp. 41–43, August, 1998. 相似文献
94.
95.
96.
S. Otakulov 《Cybernetics and Systems Analysis》1994,30(3):458-462
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 172–176, May–June, 1994 相似文献
97.
98.
An extended logistic model with a varying asymptotic upper bound for long-range peak demand forecasting is described. The model has been applied to a typical fast growing system, the Saudi Consolidated Electric Company. The forecasts are compared with actual demands and with those obtained from classical forecasting methods. The model gave relatively accurate peak demand forecasts compared with other classical methods. The model with a single load observation is capable of producing several peak demand forecasts corresponding to different levels of maximum temperature and various levels of social activity. The forecasts produced by the model were also stable irrespective of the length of the ex-post simulation period 相似文献
99.
100.