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1.
Twelve hyperlipidemic patients on long term treatment with a lipid lowering diet enriched in polyunsaturated fatty acids and with clofibrate were supplemented with vitamin E (400 mg/day). The effect on serum lipoprotein concentration, plasma lipid fatty acid composition, and adipose tissue lipoprotein lipase activity was studied. No additional lipid-lowering effect was registered during a treatment period of 4 months. A slight increase in total serum cholesterol concentration and in high density lipoprotein concentration was probably attributable to seasonal variations in serum lipoprotein concentrations. No major changes of fatty acid composition in plasma cholesteryl esters or triglycerides were recorded. However, an increased relative amount of arachidonic acid and a reduced amount of palmitic acid in the plasma phospholipids after 2 months was possibly caused by the vitamin E therapy.  相似文献   

2.
Severe iron deficiency affects lipid metabolism. To investigate whether moderate iron depletion also alters lipid variables-including lipid levels in serum and liver, hepatic lipogenesis, and fatty acid composition indicative of an impaired desaturation-we carried out experiments with rats fed 9, 13, and 18 mg iron/kg diet over a total of 5 wk. The study also included three pair-fed control groups and an ad libitum control group, fed with 50 mg iron/kg diet. The iron-depleted rats were classified as iron-deficient on the basis of reduced serum iron, hemoglobin concentration, and hematocrit. All moderately iron-deficient rats had significantly lower cholesterol concentrations in liver and serum lipoproteins than their pair-fed controls. Rats with the lowest dietary iron supply had higher concentrations of hepatic phosphatidylcholine (PC) and phosphatidylethanolamine (PE), lower activities of glucose-6-phosphate dehydrogenase, malic enzyme and fatty acid synthase, and higher triacylglycerol concentrations in serum lipoproteins than the corresponding pair-fed control rats. Moderate iron deficiency also depressed the serum phospholipid level. Moreover, several consistent significant differences in fatty acid composition of hepatic PC and PE occurred within moderate iron deficiency, which indicate impaired desaturation by delta-9 and delta-6 desaturases of saturated and essential fatty acids. We conclude that lipid variables, including cholesterol in liver and serum lipoproteins as well as fatty acid desaturation, reflect the gradations of iron status best and can be used as an indicator of the degree of moderate iron deficiency.  相似文献   

3.
The effect of the isoflavone, genistein, on the lipid metabolism of ovariectomized rats was studied. Three types of experiments were performed. In the first one, the rats were fed diets supplemented with 0.01 or 0.1% of genistein for 14 days. In the second and third experiments, the direct effect of genistein on the liver and fat tissue were measured respectively by means of liver perfusion or incubation of isolated adipocytes with the isoflavone. Genistein in food significantly decreased blood serum and muscle triglyceride concentrations and increased the level of free fatty acids in serum. Serum free cholesterol was diminished and liver cholesterol was enhanced after genistein ingestion. When genistein acted directly on the liver during perfusion, a smaller incorporation of 14C-glucose into lipids was observed, and in parallel a greater output of free fatty acids into the medium was noticed. These changes were accompanied by diminution of the liver triglyceride contents. Genistein, acting on the adipocytes strongly depressed both basal and insulin-induced lipid synthesis, when glucose was used as a substrate. The effect of the isoflavone alone on the lipolysis in the adipocytes was negligible. However, it intensified lipolysis induced by epinephrine. The results obtained let us conclude that genistein in food can reduce the fattening processes in ovariectomized rats. This effect of genistein may be attributed, at least in part, to its direct influence on lipid metabolism in the liver and adipose tissue.  相似文献   

4.
Proliferation of lipolysosomes is one of the characteristic aspects of embryonic chick hepatocytes. Formation of lipolysosomes is observed in the well-developed trans-Golgi network, with the highest frequency occurring from 11 to 14 days of incubation. The lipolysosomes usually contain a small and electron-dense lipid inclusion; however, during development, they gradually enlarge with an accompanying reduction in the electron density of the inclusion. Lipolysosomes isolated from neonatal chick liver homogenates were mainly composed of esterified cholesterol and showed considerably high activity of lysosomal enzymes. Moreover, the lipolysosome fraction is clearly shown to be a function of intralysosomal lipolysis via acid lipase. This accumulation of esterified cholesterol within lipolysosomes might be attributed to an excessive uptake and conversion of plasma lipoproteins to lipolysosomes. This concept is supported by the appearance of an abundance of coated pits and both "early" and "late" endosomes. The major components of plasma lipoprotein are low density lipoprotein (LDL) and high density lipoprotein (HDL), the cholesterol-rich lipoproteins, whose cholesterol content increases during the last week of incubation when the lipolysosomes quickly enlarge. Plasma lipoprotein particles are produced in the yolk sac epithelium from yolk very low density lipoprotein (VLDL) and transferred via the vitelline circulation to the chick liver. After hatching, when the supply of nutrients from the yolk sac is terminated, lipolysosomes immediately decrease in size and number. The cholesterol and fatty acids released are useful as an energy source and lipid metabolism in general, especially after hatching. Food intake induces the use of and accelerates the disappearance of lipolysosomes. Instead of lipolysosomes, lipid droplets appear and increase in number and size with concomitant increases of triglyceride concentrations in the liver homogenates, suggesting that lipogenesis has begun in the chick hepatocyte.  相似文献   

5.
PURPOSE: The effects of embryonic development on lipid composition in the retina were studied in 7, 11, 15, and 18-day-old chick embryos and newly hatched chicks. METHODS: The proportions of phospholipids, free and esterified cholesterol, diacylglycerides, and free fatty acids were determined using the Iatroscan TLC/FID procedure. Gas chromatography and mass spectrometry were used to determine the fatty acid composition. RESULTS: The major phospholipid species were phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, lysophosphatidylcholine, and sphingomyelin. Concentrations of the analyzed components have been related to the chronology of concrete stages of retinal development. The fatty acid composition of the total lipids, (n-6):(n-3) and saturated: unsaturated fatty acid ratios, and other parameters are reported. The proportions of total saturated and total monounsaturated fatty acids decreased very little from day 7 to hatching, whereas total polyunsaturated fatty acids nearly doubled over the same period. The increase in C18:2(n-6) from day 11 onwards was not followed by a similar increase in C20:4(n-6), hence the C20:4 to C18:2 ratio decreased with age. CONCLUSIONS: The cholesterol:phospholipid ratio decreased from day 7 to day 15 and increased from day 15 to hatching. High proportions of esterified cholesterol, very probably originating in the retinal pigment epithelium, were also recorded. Total saturated and monounsaturated fatty acids decreased, while polyunsaturated fatty acids increased during the period of initial retinal growth.  相似文献   

6.
Serum lipid levels were determined in 30 children with kwashiorkor and in 30 healthy children of comparable age. The serum concentrations of unesterified and esterified cholesterol, albumin and the cholesterol esterifying activity (CEA) were also measured in children with kwashiorkor before treatment and after recovery. All serum lipid fractions were significantly lower in kwashiorkor than in the normal children. After treatment and recovery, serum lipid levels were comparable to those observed in normal children. There was also a significant increase in serum cholesterol esterifying activity (CEA) following recovery from kwashiorkor.  相似文献   

7.
The effects of different amounts of dietary zinc and copper on cholesterol metabolism in the rat were investigated. The levels of the minerals used were comparable to those likely to occur in a normal mixed North American diet. Although the different levels affected the serum, liver, and femur concentrations of the minerals, they had no effect on the levels of serum and liver, total, esterified or free cholesterol, or on high density lipoprotein cholesterol. It was concluded that dietary copper and zinc, at levels likely to occur in a normal mixed diet, are not significant factors in cholesterol metabolism.  相似文献   

8.
Partial hepatectomy caused a marked stimulation of cholesterol and fatty acid syntheses without affecting serum total cholesterol, total phospholipid and triacylglycerol concentrations of rats so far examined 48 h after the operation. Serum free cholesterol level, however, was increased by the treatment and the ratio of lysophosphatidylcholine to phosphatidylcholine was concomitantly decreased, suggesting the impairment of serum lecithin: cholesterol acyltransferase activity. The lipid content in the liver, especially triacylglycerol and ester cholesterol, was increased markedly by the operation. Feeding of a high cholesterol diet which elevated serum cholesterol and phospholipid levels to the partially hepatectomized rats, accelerated the accumulation of hepatic triacylglycerol and ester cholesterol by the partial hepatectomy. The weight of the regenerating liver was not influenced by cholesterol feeding, which suggested that cholesterol feeding did not inhibit the regeneration mechanism of the liver. The increase of cholesterol synthesis after partial hepatectomy was inhibited by cholesterol feeding. Therefore, it is conceivable that the negative feed-back control of cholesterol synthesis is induced by cholesterol feeding under the stimulated cell divisions of the liver after partial hepatectomy. It is suggested from the present data that a large amount of the cholesterol which is necessary for cell growth can be taken up from serum, when serum cholesterol concentration is high.  相似文献   

9.
The effect of 10 day-low dosage of n-3 long chain fatty acids (390 mg/day of EPA and 252 mg/day of DHA) on lipid and apolipoprotein (Apo) concentrations has been studied in nine normolipidaemic women aged 28.9 +/- 4.2 years. n-3 fatty acid supplementation did not significantly decrease total cholesterol and triglyceride levels but markedly decreased the Apo A1 and Apo B concentrations (12.7%, p < 0.01 and 23.1%, p < 0.001, respectively), while the Apo A1/Apo B ratio significantly increased (14.8%, p < 0.02). In contrast to the individual variations found for triglycerides and cholesterol, Apo changes indicate a fairly homogeneous response to the fish oil supplement. In seven women Apo A1 decreased (> 10%), whereas Apo B decreased (> 10%) in all of them. The Apo A1/Apo B ratio increased (> 10%) in five of these nine women. Changes in Apo A-1 and Apo B did not significantly correlate with changes in serum lipids. These findings suggest that short-term supplementation with low amount of n-3 long chain fatty acids, EPA and DHA, influences the serum Apo content more than the lipid levels in normolipidaemic women.  相似文献   

10.
OBJECTIVE: We tested the hypothesis that serum free (nonesterified) fatty acid and triglyceride concentrations are increased in nulliparous women with preeclampsia relative to women with uncomplicated pregnancies and that these lipids decrease post partum, consistent with the known resolution of clinical symptoms. The relationships between serum concentrations of these lipids and the lipid peroxidation metabolite malondialdehyde were also examined. STUDY DESIGN: Predelivery and 24 to 48 hour postpartum venous blood samples were collected from eight women with preeclampsia and nine women with uncomplicated pregnancies after an 8- to 10-hour fast. Sera were analyzed for concentrations of triglycerides, free fatty acids, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and malondialdehyde. RESULTS: Antepartum serum triglyceride and free fatty acid concentrations were increased approximately twofold in women with preeclampsia relative to uncomplicated pregnancies (p <0.02 and 0.004, respectively). Total, high-density lipoprotein, and low-density lipoprotein cholesterol concentrations did not differ between groups. Concentrations of all lipids decreased significantly in both groups within 48 hours post partum. However, triglyceride and free fatty acid concentrations remained higher in women with preeclampsia (p<0.006, both variables). Triglyceride and free fatty acid concentrations correlated positively, both ante partum (R2 0.42, p<0.01) and post partum (R2 0.39, p<0.02). Antepartum concentrations of malondialdehyde were 50% higher in women with preeclampsia (p<0.01) and decreased post partum (p <0.02) but did not decrease in controls (p = 0.07). Antepartum serum triglycerides and free fatty acids correlated positively with malondialdehyde concentrations (R2 0.38, p <0.02, both cases). CONCLUSION: Triglycerides and free fatty acids, but not cholesterol, are increased in preeclampsia and correlate with the lipid peroxidation metabolite malondialdehyde. We speculate that these interactions may contribute to endothelial cell dysfunction in preeclampsia.  相似文献   

11.
Growing dogs were fed diets containing soy oil or poultry fat as the main fat source and soybean meal or meat meal as the main protein source to examine the effects of types of dietary fat and protein on fatty acid concentrations in serum and skin and on serum cholesterol concentrations. Dogs fed diets containing soy oil had higher serum linoleic acid concentrations and lower serum oleic acid, arachidonic acid, and cholesterol concentrations than dogs fed diets containing poultry fat. The type of dietary protein had marginal effects on fatty acid concentrations and did not affect serum cholesterol. Similar differences were found in cutaneous fatty acid concentrations, with soy oil-fed dogs having significantly (P < 0.05) higher linoleic acid and lower oleic acid concentrations in their skin than had poultry fat-fed dogs. This study suggested that dietary fat source influences serum and cutaneous fatty acid concentrations and serum cholesterol concentrations in dogs, irrespective of dietary protein source.  相似文献   

12.
Rats tube-fed a diet devoid of threonine accumulated triacylglycerols in their livers, starting on the third day of the diet. The fatty acid composition of the accumulated lipid and the contribution of novo synthesized fatty acids to the lipid accumulation, as determined with tritiated water as a radioactive precursor for fatty acid synthesis, suggested that an increased hepatic de novo synthesis of fatty acids is not a major factor for the development of this liver lipid accumulation. The metabolism of intravenous injected 3H-oleic acid, the Triton-induced hyperlipemia and the activity of lipoprotein lipase in adipose tissue was also studied. None of these studies revealed any significant difference between the threonine-deficient and control rats. It is concluded that the hepatic triacylglycerol accumulation in the threonine-deficient rats does not result from any gross abnormality in the rate of liver triacylglycerol formation or secretion to the plasma. It is suggested that a possible causative mechanism is a derangement in the metabolism of the storage pool of liver triacylglycerols.  相似文献   

13.
Cells of early atherosclerotic lesions have an increased content of cholesteryl esters and enhanced rate of cholesterol esterification. The present study was carried out to elucidate whether these changes could be reproduced in a purely in vitro system. Cultures of rabbit aortic medial cells were incubated in a medium containing 10% of either normal rabbit serum (control cells) or serum from rabbits with cholesterol-induced hyperlipidemia (hyperlipidemic cells). The incorporation rate of [1-14C]oleate into cellular cholesteryl esters increased two- to threefold after four hours' incubation with hyperlipidemic serum and remained elevated during the rest of the eight days' study. After seven days' incubation the hyperlipidemic cells incorporated significantly more (+13%) oleate into triglycerides and significantly less (-15%) oleate into phospholipids than did the control cells. Cholesteryl ester content of the hyperlipidemic cells rose steeply for about two days, with a slower rise thereafter. In hyperlipidemic cells the esterified cholesterol content was significantly higher (315 ng/mug DNA) than in the control cells (79 ng/mug DNA). Hyperlipidemic cells showed a slow but significant rise of free cholesterol as well (from 1.15 mug/mug DNA in control to 1.50 mug/mug DNA). The results indicate that lipid changes resembling those in early atherosclerotic lesions can be brought about in vitro 0y treatment of aortic cells with hyperlipidemic serum.  相似文献   

14.
Sprague-Dawley rats (n = 32) were fed diets without fiber (control) or containing 1 or 5% chicory extract or 5% inulin for 4 wk; 0.2% cholesterol was added to all diets. Rats fed chicory extract and inulin diets had significantly higher serum high density lipoprotein (HDL) cholesterol and generally lower low density lipoprotein (LDL) cholesterol concentrations, thus significantly greater ratios of HDL/LDL cholesterol compared with the controls (P < 0.05). The serum apolipoprotein B/apolipoprotein A-1 ratio was significantly lower in rats fed diets containing chicory extract or inulin than that in rats fed fiber-free diets, due to significant reductions in apolipoprotein B concentration (P < 0.05). Greater liver lipid and triglyceride concentrations were observed in rats fed chicory extract or inulin diets compared with the controls (P < 0.05). However, liver phospholipid and cholesterol concentrations were not significantly different among groups (P > 0.05). Addition of 5% inulin to the diet resulted in greater cecal weight, whereas both 5% chicory extract and 5% inulin resulted in greater cecal propionic acid concentration compared with the controls (P < 0.05). Rats fed chicory extract and inulin had significantly greater fecal lipid, cholesterol and bile acid excretions than those fed fiber-free diets (P < 0.05). The results of this study suggest that the improved lipid metabolism observed in rats fed chicory extract (mainly inulin component) may be caused by an alteration in the absorption and/or synthesis of cholesterol, which might result from the changes in cecal fermentation, and by an increase in the fecal excretion of lipid, cholesterol and bile acid.  相似文献   

15.
Total lipid, free and esterified cholesterol and triglycerides significantly increase in concentration with increasing age. Palmitic, palmitoleic, oleic and linoleic acid behave in the same way. Free fatty acids, phospholipids and stearic acid show the same concentrations in all groups of age. C20 fatty acids demonstrate a competitive regulatory mechanism of desaturase activity in their age dependant distribution. While the 20:3(n-9), a product of the endogenous (n-9) family, increases, the 20:3(n-6) and 20:4(n-6), both desaturation and chain elongation products of the essential n-6 family, decrease. Such behavior has been demonstrated in many feeding studies (12, 13, 15, 16, 17, 29) and is interpreted as a result of competitive substrate interaction on desaturase activity.  相似文献   

16.
OBJECTIVE: A mutant soybean line (A16) low in linolenic acid content (2% of oil by weight) was developed to increase oil oxidative stability. It was unknown whether serum lipid and lipoprotein concentrations in humans would be affected should A16 soybean oil (A16 oil) replace commercial soybean oil in diets. This study was conducted to examine the hypothesis that in free-living normolipidemic women, the consumption of A16 oil at approximately 10% of energy intake (en%) would not affect serum lipids and lipoproteins differently than would the consumption of the same amount of a commercial soybean oil with 7% of linolenic acid content. DESIGN: Fifteen free-living female college students consumed the soybean oil daily with regular meals for 9 weeks in different orders, with each test oil being eaten for 3 weeks. During the study, 13 en% was provided by each test oil and a total of 35 en% was from dietary fat. Serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), low-density lipoprotein cholesterol (LDL cholesterol) and triacylglycerides (TAG) were measured. Serum total fatty acid patterns were analyzed as well. RESULTS: Each of the three test oils decreased serum total cholesterol, LDL cholesterol and TAG concentrations from the baseline values. The feeding of A16 and commercial soybean oils decreased serum HDL cholesterol significantly compared with coconut oil (p < 0.05). Dietary inclusion of coconut oil increased serum myristic acid significantly more than did either soybean oil (p < 0.01). Serum arachidonic acid concentrations were significantly greater with A16 consumption than with commercial soybean oil consumption (p < 0.001). CONCLUSION: A16 and commercial soybean oils both diminished serum HDL cholesterol. Although the fatty acid composition differed between the two soybean oils, A16 oil and commercial oil had similar effects on serum concentrations of lipoproteins and lipids. With increased oxidative stability, A16 oil is a good alternative to commercial soybean oil.  相似文献   

17.
Newborn suckling Simmentaler calves (10 males and 9 females) in a cow-calf operation were examined from birth up to the age of 3 months. The average daily gain from 47 to 120 kg was 0.86 kg. Except for higher average daily weight gains and insulin-like growth factor-I concentrations and lower thyroid hormone levels in male than female calves, there were no significant sex differences. Plasma glucose, total protein and immunoglobulin G concentrations increased on day 1 of life, thrombocyte number and plasma triglyceride concentrations rose during the first 7 days, whereas lymphocyte and monocyte percentage and plasma inorganic phosphorus, phospholipid, cholesterol and albumin concentrations increased during the first 14 or 21 days and then remained elevated. Eosinophil percentage increased after 3 weeks and insulin-like growth factor-I concentrations increased over the whole growth period. There were transient elevations of plasma glucagon concentrations up to day 14, of the activity of alkaline phosphatase transiently up to day 7 and of gamma-glutamyltransferase, aspartate aminotransferase and lactate dehydrogenase activities on day 1 of life. Plasma iron concentration transiently decreased up to day 28 and creatine kinase activity up to day 7. Total white blood cell number, neutrophil percentage, packed cell volume and concentrations of haemoglobin, calcium, magnesium (after a transient rise on day 1), non-esterified fatty acids, bilirubin, creatinine, triiodothyronine and thyroxine decreased from birth up to days 42, 56, 28, 28, 21, 84, 14, 14, 7, 14 and 7, respectively. Basophil percentage and concentrations of beta-hydroxybutyrate, urea and insulin did not exhibit significant age-dependent changes. The behaviour of most traits in the first weeks was the same in suckling calves under study as in non-suckling pre-ruminant calves. However, packed cell volume, red blood cell number, haemoglobin and plasma iron concentrations were higher, whereas glucose and insulin concentrations were lower than normally found in veal calves. On the other hand, concentrations of glucose, insulin and insulin-like growth factor-I in suckling calves in the third month of age were higher than can normally be measured in breeding calves.  相似文献   

18.
Serum high density lipoprotein (HDL) cholesterol, total serum cholesterol and triglycerides were determined in twenty men before, immediately after, and 1, 2 and 4 days after a 70 km cross-country ski race. HDL cholesterol increased by 12% of the pre-race level immediately after the race, rose further to 17% above the initial level on the following day, and was still elevated 4 days after the race. LDL + VLDL cholesterol, however, showed a tendency to decrease immediately after the race and was reduced by 17% and 11% of the pre-race level on the following 2 days. Triglycerides were reduced by 30% of the initial level immediately after the race, were still low on the following day, but were restored to normal 2 days after the race. It is concluded that a single exposure to prolonged heavy exercise induces changes in the HDL metabolism, showing that the physical exercise per se plays an important role for the increased HDL level seen in well-trained athletes.  相似文献   

19.
The time course of incorporation of [14C]arachidonic acid and [3H]docosahexaenoic acid into various lipid fractions in placental choriocarcinoma (BeWo) cells was investigated. BeWo cells were found to rapidly incorporate exogenous [14C]arachidonic acid and [3H] docosahexaenoic acid into the total cellular lipid pool. The extent of docosahexaenoic acid esterification was more rapid than for arachidonic acid, although this difference abated with time to leave only a small percentage of the fatty acids in their unesterified form. Furthermore, uptake was found to be saturable. In the cellular lipids these fatty acids were mainly esterified into the phospholipid (PL) and the triacyglycerol (TAG) fractions. Smaller amounts were also detected in the diacylglycerol and cholesterol ester fractions. Almost 60% of the total amount of [3H]Docosahexaenoic acid taken up by the cells was esterified into TAG whereas 37% was in PL fractions. For arachidonic acid the reverse was true, 60% of the total uptake was incorporated into PL fractions whereas less than 35% was in TAG. Marked differences were also found in the distribution of the fatty acids into individual phospholipid classes. The higher incorporation of docosahexaenoic acid and arachidonic acid was found in PC and PE, respectively. The greater cellular uptake of docosahexaenoic acid and its preferential incorporation in TAG suggests that both uptake and transport modes of this fatty acid by the placenta to fetus is different from that of arachidonic acid.  相似文献   

20.
OBJECTIVE: The purpose was to evaluate the metabolic effects of Mircette (brand of desogestrel/ethinyl estradiol and ethinyl estradiol), a low-estrogen, desogestrel-containing oral contraceptive. STUDY DESIGN: Women taking Mircette were evaluated to determine its effects on lipid profiles (n = 74), carbohydrate metabolism (n = 25), and endocrine parameters (n = 53). RESULTS: During cycles 3 and 6 of Mircette treatment, changes from baseline included mean increases in serum triglycerides and very low-density lipoprotein cholesterol ranging between 50% and 60%. Smaller mean increases were observed at these time points in high-density lipoprotein cholesterol subfraction 2 (range between 17% and 25%), total cholesterol (<10%), high-density lipoprotein cholesterol (range between 10% and 15%), and high-density lipoprotein cholesterol subfraction 3 (range between 9% and 13%), with only nominal changes (<6%) in low-density lipoprotein cholesterol and lipoprotein. Patients receiving Mircette showed no mean changes in fasting plasma glucose or serum insulin levels but did have modest increases in glucose and insulin levels after a glucose challenge. Mircette treatment suppressed follicle-stimulating hormone, luteinizing hormone, 17beta-estradiol, and progesterone to levels consistent with inhibition of ovulation and increased concentrations of thyroid- and cortisol-binding globulins. CONCLUSIONS: Overall, Mircette treatment was associated with expected effects on the pituitary-ovarian axis, triglycerides, and serum binding proteins; a modest decline in glucose tolerance; and a favorable effect on lipid profiles as a result of increases in total high-density lipoprotein cholesterol and high-density lipoprotein cholesterol subfraction 2 in the absence of changes in total cholesterol or low-density lipoprotein cholesterol.  相似文献   

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