首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Sea food is a major source of animal protein. Marine foods are very rich sources of mineral components. The total content of minerals in the raw flesh of marine fish and invertebrates is in the range of 0.6–1.5% wet weight. The contents of Na, K, Ca, Mg and P are up to 1 mg/100 g, whereas those of Fe, Zn, I are less than 1 mg/100 g. Mussels (Mytilus galloprovincialis) were investigated for macro and trace element composition throughout the year. Ranges of moisture, ash, protein and fat contents were 79.76–87.46 g/100 g, 1.06–2.06 g/100 g, 7.28–12.65 g/100 g and 0.33–3.49 g/100 g, respectively. While the highest protein and fat values were found in the summer (July–August), the highest moisture and ash contents were found in the winter (December–January). The contents of highest Na, K, Ca were found in the summer. Cadmium, lead and copper were found to be below the legislative limits throughout year. High levels of mercury were found in January and October. It should be discussed whether mussel may provide an alternative source of mineral for healthy nutrition.  相似文献   

2.
In this study, concentrations of trace metals in five fish species (Cyprinus carpio, Capoeta tinca, Leiciscus cephalus, Carassius gibelio and Silurus glanis) and sediments collected from some lakes in Tokat were determined by atomic absorption spectrometry. The fish species and sediment samples were collected from six lakes (Bedirkale, Boztepe, Belp?nar?, Avara, Ataköy and Ak?n) in Tokat, Turkey in spring and summer during 2003–2004. The samples were digested with a microwave digestion system. The maximum Fe, Mn, Zn, Cu, Pb, Cr and Ni concentrations of sediment samples were 2138, 232, 38.9, 8.2, 7.0, 10.7 and 55.4 μg/g, respectively. The maximum Fe, Zn, Cu, Pb, Cr, Mn and Ni concentrations of the fish samples were 167, 48.6, 3.6, 2.8, 1.6, 64.3 and 5.6 μg/g, respectively.  相似文献   

3.
The concentrations of cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead and zinc were determined by ICP-AES in muscles and livers of 12 fish species sampled from the Marmara, Aegean and Mediterranean seas of Turkey. Iron showed the highest levels in examined tissues of all fish species. Following Fe, Zn generally showed the second highest levels. Metal concentrations in edible parts of fish species were 0.02–0.37 mg kg−1 for cadmium, 0.04–0.41 mg kg−1 for cobalt, 0.04–1.75 mg kg−1 for chromium, 0.32–6.48  mg kg−1 for copper, 7.46–40.1 mg kg−1 for iron, 0.10–0.99  mg kg−1 for manganese, 0.02–3.97 mg kg−1 for nickel, 0.33–0.86 mg kg−1 for lead, 4.49–11.2 mg kg−1 for zinc, respectively. All metal concentrations in livers were higher than those in muscles. In some stations, cadmium and chromium concentrations in both muscles and livers, and lead levels in livers of the examined species were higher than permissible safety levels for human uses.  相似文献   

4.
《Journal of dairy science》2022,105(8):6693-6709
Our objectives were to evaluate the effects of complete replacement of supplementary inorganic salts of trace minerals (STM) by organic trace minerals (OTM) in both pre- and postpartum diets on feeding behavior, ruminal fermentation, rumination activity, energy metabolism, and lactation performance in dairy cows. Pregnant cows and heifers (n = 273) were blocked by parity and body condition score and randomly assigned to either STM or OTM diets at 45 ± 3 d before their expected calving date. Both groups received the same diet, except for the source of trace minerals (TM). The STM group was supplemented with Co, Cu, Mn, and Zn sulfates and Na selenite, whereas the OTM group was supplemented with Co, Cu, Mn, and Zn proteinates and selenized yeast. Treatments continued until 156 days in milk and pre- and postpartum diets were formulated to meet 100% of recommended levels of each TM in both treatments, taking into consideration both basal and supplemental levels. Automatic feed bins were used to assign treatments to individual cows and to measure feed intake and feeding behavior. Rumination activity was monitored by sensors attached to a collar from wk ?3 to 3 relative to calving. Blood metabolites were evaluated on d ?21, ?10, ?3, 0, 3, 7, 10, 14, 23, and 65 relative to calving. Ruminal fluid samples were collected using an ororuminal sampling device on d ?21, 23, and 65 relative to calving, for measurement of ruminal pH and concentration of volatile fatty acids. Cows were milked twice a day and milk components were measured monthly. Cows supplemented with OTM tended to have longer daily feeding time (188 vs. 197 min/d), and greater dry matter intake (DMI; 12.9 vs. 13.3 kg), and had a more positive energy balance (3.6 vs. 4.2 Mcal/d) and shorter rumination time per kg of dry matter (DM; 40.1 vs. 37.5 min/kg of DM) than cows supplemented with STM during the prepartum period. In the postpartum period, OTM increased DMI in multiparous cows (24.1 vs. 24.7 kg/d) but not in primiparous cows (19.1 vs. 18.7 kg/d). The difference in DMI of multiparous cows was more evident in the first 5 wk of lactation, when it averaged 1 kg/d. Milk yield was not affected by treatment in multiparous cows (44.1 vs. 44.2 kg/d); however, primiparous cows supplemented with OTM had lesser yields than primiparous cows supplemented with STM (31.9 vs. 29.8 kg/d). Cows supplemented with OTM had a greater percentage of protein in milk (3.11 vs. 3.17%), reduced concentration of nonesterified fatty acids in serum (0.45 vs. 0.40 mmol/L), and rumination activity (30.1 vs. 27.8 min/kg of DM) than cows supplemented with STM. At the end of the transition period, cows supplemented with OTM had reduced molar proportion of acetate, reduced pH, and tended to have a greater concentration of total volatile fatty acids in ruminal fluid. In conclusion, complete replacement of STM by OTM caused modest changes in rumen fermentation, feeding behavior, energy metabolism, and performance of dairy cows, improving postpartum DMI in multiparous cows and reducing circulating levels of nonesterified fatty acids. The pre-absorptive effects of TM source and the parity specific responses on performance warrant further research.  相似文献   

5.
Trace metal content of nine fish species harvested from the Black and Aegean Seas were determined by microwave digestion and atomic absorption spectroscopy (MD–AAS). Verification of the MD–AAS method was demonstrated by analysis of standard reference material (NRCC-DORM-2 dogfish muscle). Trace metal content in fish samples were 0.73–1.83 μg/g for copper, 0.45–0.90 μg/g for cadmium, 0.33–0.93 μg/g for lead, 35.4–106 μg/g for zinc, 1.28–7.40 μg/g for manganese, 68.6–163 μg/g for iron, 0.95–1.98 μg/g for chromium, and 1.92–5.68 μg/g for nickel. The levels of lead and cadmium in fish samples were higher than the recommended legal limits for human consumption.  相似文献   

6.
The methanolic extracts of 16 Helichrysum species were investigated for their in vitro antioxidant, radical scavenging and antimicrobial activities. All the extracts showed strong antioxidant and radical scavenging activity. The highest total antioxidant capacity as ascorbic acid equivalents (AAE) of 194.64 mg/g dry extract was obtained for Helichrysum noeanum in the phosphomolybdenum assay. The highest IC50 value (7.95 μg/ml) was observed for the extract of Helichrysum stoechas subsp. barellieri in the DPPH assay. The total phenolic contents of the extracts ranged from 66.74 to 160.63 mg gallic acid equivalents (GAE)/g dry extract. The major component present in the extracts was identified as chlorogenic acid followed by apigenin-7-glucoside and apigenin by HPLC analysis. All the extracts showed significant antimicrobial activity against microorganisms containing 13 bacteria and two yeasts in the agar diffusion method.  相似文献   

7.
《Journal of dairy science》2023,106(4):3023-3042
An experiment was conducted to evaluate the effects of inorganic trace minerals (TM) and reduced levels of TM by using proteinate forms of Co, Zn, Mn, and Cu, and Se-yeast in diets of transition cows on performance, TM concentrations in colostrum, plasma, and liver, blood metabolites, antioxidant status, peripheral neutrophil activity, and oocyte quality. Thirty-two Holstein cows (22 multiparous and 10 primiparous cows) were enrolled in this study from 30 d before the expected calving date to 56 DIM. Cows were blocked according to body condition score, parity, and previous milk yield and randomly assigned to one of the following treatments: control (CON), with TM (Zn, Cu, Mn, and Co) supplied in form of sulfate and Se as sodium selenite to meet or exceed requirement estimates of the National Research Council; and proteinate trace minerals (PTM), with TM supplied bound with AA and peptides at 50% of CON levels and inorganic Se replaced with Se-yeast at 100% of CON level. Treatments were supplied until 56 DIM. Eight cows were removed from the study because of early calving (n = 3) or health issues (n = 5); thus, data of 24 cows (16 multiparous and 8 primiparous cows) were used in the statistical analysis. No differences between treatments were detected on nutrient intake or digestibility. Total excretion of purine derivatives was decreased when feeding PTM during the prepartum period. Feeding reduced levels of TM in proteinate form resulted in greater yield of milk (27.7 and 30.9 kg/d for CON and PTM, respectively) and protein (0.890 and 0.976 kg/d) between wk 5 and 8 of lactation. No treatment differences were detected for feed efficiency, milk somatic cell count, and milk urea nitrogen. Cows fed PTM had lower milk fat concentration during the 56 d of evaluation (4.08 and 3.74% for CON and PTM, respectively). Selenium concentration was greater in colostrum of cows fed PTM compared with CON (48.5 and 71.3 µg/L for CON and PTM, respectively), whereas Zn, Cu, and Mn concentrations were not different. Cows fed PTM showed lower liver Cu concentration compared with CON (51.4 and 73.8, respectively). Plasma concentrations of Mn and Zn were lower, but plasma Se concentration tended to be higher with PTM treatment. Feeding PTM resulted in greater blood concentrations of urea-N (16.6 and 18.2 mg/dL for CON and PTM, respectively) and β-hydroxybutyrate (0.739 and 0.940 mmol/L). Counts of lymphocytes were higher with PTM but counts of monocytes were lower in complete blood cell count. No differences were observed in serum concentrations of superoxide dismutase and glutathione peroxidase. No differences were detected in phagocytosis and oxidative burst potential of neutrophils after incubation with bacteria. Cows fed PTM had fewer viable oocytes per ovum pick-up in comparison with CON (8.00 and 11.6). Feeding PTM to transition cows may sustain performance without altering neutrophil activity despite some alterations in blood TM concentrations. More studies should be performed to evaluate production and fertility measurements when reducing TM dietary levels by using proteinate forms and Se-yeast with larger number of animals.  相似文献   

8.
The relationship between the occurrence and movements of Rhyzopertha dominica (F.), a serious pest of stored cereal grains, in distinctly different habitats is poorly known. Understanding the feeding ecology and dispersal patterns of R. dominica may likely help predict the abundance or movement of this pest in various habitats. Natal sites and movement of insects are studied using intrinsic methods involving elemental analyses. In this study, to understand the dietary history of R. dominica, trace and macro elements were used as potential markers. Insects reared on selected diets under laboratory conditions and adult beetles collected from the periphery of granaries or inside forested woodlands were used to determine 10 different elements in their body tissues. Quantities of 10 elements were also determined in respective laboratory hosts. The main discriminant elements for laboratory-reared R. dominica were Na, S and Zn, while significantly different elements were distinctive among field-collected beetles and included P, Ca, K, Zn, and Cu. The amount of Zn quantified in acorn-fed lab reared beetles was significantly lower than wheat- or corn-fed insects. Similarly, beetles captured in woodlands had significantly lower Zn in their body signatures, suggesting acorn seeds may have served as an alternate host in Quercus spp. dominated woodlands. Our studies showed that elemental profiles may potentially be used as biological markers for delineating food sources of R. dominica to mainly discriminate whether beetles originated in agricultural vs. wooded habitats.  相似文献   

9.
Three species of mites, Acarus siro L., A. farris Oud. and A. immobilis Griffiths, were tested under optimum physical conditions (90% r.h. and 20°C). In most experiments hypopus production was estimated by comparing the number of protonymphs which developed promptly to tritonymphs with the number which developed to hypopi.

Hypopus formation appeared to be favoured by malnutrition in the presence of a certain minimum quantity of B vitamins. The period of response embraced the active larval and active protonymphal stage and the response appeared to be cumulative. It scemed to remain reversible through the larval stage but at some point during the active protonymphal period it became irreversible. The developmental period of those protonymphs which became hypopi was much extended compared with the developmental period of those which proceeded directly to tritonymphs. It is concluded that this extension is associated with physiological and developmental changes peculiar to the hypopus and not with starvation.

Acarus immobilis and Acarus farris, which have been shown to be mainly field species, produced more hypopi than the storage species Acarus siro, one population of which could not be induced to produce any hypopi. It is concluded that previously published records of the “Flour mite” motile hypopus from field habitats are probably based on the A. farris hypopus and the records of the “Flour mite” motile hypopus occurring in food stores are scarce because the storage species A. siro has a poor potential for hypopus formation or rarely encounters starvation conditions. Misidentifications, coupled with interspecific differences in hypopus production, may explain some of the conflicting results published by previous workers testing the same physical factors.  相似文献   


10.
报道了采用八种微量元素进行试验,以探索它们对Xanthomonas XC-XH99诱变株生长代谢和胞外多糖积累的影响。结果表明,八种微量元素都对XanthomonasXC—XH99诱变株生长代谢和胞外多糖积累有较明显的促进作用,将八种微量元素组合成复因子加入培养基中,OD值和胞外多糖分别比对照样平均提高了23.1%和21.7%,且优于各单因子。  相似文献   

11.
12.
《Journal of dairy science》2023,106(5):3493-3508
Our objectives were to evaluate the impact of supplementary trace mineral (TM) form—inorganic salts (STM; Co, Cu, Mn, Zn sulfates, and Na selenite) or organic (OTM; Co, Cu, Mn, Zn proteinates, and selenized yeast)—in the prepartum diet on quantity and quality of colostrum, passive immunity, antioxidant biomarkers, cytokine responses to lipopolysaccharide (LPS), health, and growth of newborn calves. Pregnant heifers (n = 100) and cows (n = 173) were enrolled at 45 d before calving, blocked by parity and body condition score, and allocated randomly to STM (50 heifers; 86 cows) or OTM (50 heifers; 87 cows) supplementation. Cows in both treatments were fed the same diet, except for the source of supplementary TM. Within 2 h of calving, dams and calves were separated, colostrum was harvested, the yield was measured, and a sample was saved for posterior analyses of colostrum quality. A subgroup of calves (n = 68) had a blood sample collected before colostrum feeding. After colostrum feeding, all samples and data collection were limited to 163 calves (STM = 82; OTM = 81) fed 3 L of good quality (Brix% >22) maternal colostrum via nipple bottle minutes after harvesting. Concentration of IgG in colostrum and serum was determined 24 h after colostrum feeding using radial immunodiffusion. Concentration of TM in colostrum and serum were performed by inductively coupled plasma mass spectrometry. Activity of glutathione peroxidase, ferric reducing ability of plasma, and concentration of superoxide dismutase were evaluated in plasma by colorimetric assays. Ex vivo whole blood stimulation with LPS was performed on d 7 of life to evaluate cytokine responses in a subgroup of 66 calves. Health events were recorded from birth to weaning, and body weight was recorded at birth (all calves) and on d 30 and 60 (heifers only). Continuous variables were analyzed by ANOVA and binary responses were analyzed by logistic regression. Complete replacement of STM by OTM in prepartum diet resulted in greater concentration of Se (461 vs. 543 ± 7 μg/g; ± SEM) but did not alter the concentration or total mass of other TM and IgG in colostrum. Female calves of the OTM group had greater concentration of Se in serum at birth (0.23 vs. 0.37 ± 0.05 μg/mL), were lighter in weight at birth (40.9 vs. 38.8 ± 0.6 kg) and weaning (93.2 vs. 89.7 ± 1.6 kg) than those of the STM group. Maternal treatments did not affect passive immunity or antioxidant biomarkers. On d 7, basal concentrations (log10 of concentration in pg/mL) of IFNγ (0.70 vs. 0.95 ± 0.083) and LPS-stimulated concentrations of CC chemokine ligand 2 (CCL2; 2.45 vs. 2.54 ± 0.026), CC chemokine ligand 3 (CCL3; 2.63 vs. 2.76 ± 0.038), IL-1α (2.32 vs. 2.49 ± 0.054), and IL-1β (3.62 vs. 3.86 ± 0.067) were greater in OTM than in STM. Supplementation with OTM in pregnant heifers, but not in pregnant cows, reduced the incidence of preweaning health problems in their calves (36.4 vs. 11.5%). Complete replacement of STM by OTM in the prepartum diet did not cause major changes in colostrum quality, passive immunity, and antioxidant capacity, but increased cytokine and chemokine responses to LPS on d 7 of life and benefited preweaning health of calves born to primiparous cows.  相似文献   

13.
Staphylococcus aureus is a major foodborne pathogen and it has the ability to produce a number of extracellular toxins. We analyzed 1070 food samples obtained from retail markets and dairy farms in the Marmara Region of Turkey for the presence of S. aureus. Out of 147 isolates, 92 (62.6%) were enterotoxigenic. PCR was used to investigate the presence of staphylococcal enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu), exfoliative toxin genes (eta and etb) and the toxic − shock syndrome toxin gene (tst). The PCR results showed that 53.3% of the isolates contained staphylococcal enterotoxin-like (SEl) toxin genes (seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu) which were more frequent than classical enterotoxin genes (sea to see). Furthermore, seo, sei, sem, seg, seu and sec were found in 37.0, 32.7, 30.4, 29.3, 29.3 and 27.2% of the isolates, respectively. The tst gene was detected and confirmed by DNA sequencing in 9 isolates. The presence of eta and etb were not found in the isolates. Enterotoxigenic capabilities of isolates with SEA-SEE were investigated by ELISA. Enterotoxigenic S. aureus isolates produced one to three enterotoxins, with the most frequently produced types being enterotoxin A and C. There was a correlation of 72.1% between production of a specific toxin and the presence of the respective genes. PFGE analysis was used to identify genetic-relatedness of enterotoxigenic S. aureus isolates and the results revealed that 13 groups of isolates from different or the same origin that contained the same genes showed 100% homology with indistinguishable band patterns. The other enterotoxigenic isolates showed related band patterns with 72-86% homology in sea-, 61-90% homology in sec-, 80-96% homology in seh-, and 69-96% homology in sep-positive isolates. To our knowledge, this is the first study to examine enterotoxins and related gene contents of S. aureus food isolates in the Marmara Region of Turkey.  相似文献   

14.
One hundred seafood samples (fish, squid and mussel) were collected from the Argentine Atlantic coast and screened for Listeria spp. The isolates were characterized by biochemical tests, serotyping, phage typing and macrorestriction enzymes analysis of DNA (pulsed-field gel electrophoresis). The overall frecuency (n=100) ofListeria spp. was 12%. Of the 12 isolated strains, three strains isolated from different squid samples were identified as L. monocytogenes and nine strains from fish, mussels and squid as L. innocua. All three L. monocytogenes strains belonged to serovar 4b; eight strains of L. innocua were serovar 6a and one strain of L. innocua was serovar 6b. All three L. monocytogenes strains, but only one of the nine L. innocua strains, were phage-typeable. One restriction profile was detected with Apa I and Asc I for L. monocytogenes strains and three with the same enzymes for L. innocua strains. The combination of these patterns allowed definition of four distinct groups within the 12 strains. The results of this study showed that phenotypic methods remain appropriate but that pulsed-field gel electrophoresis is useful for epidemiological purposes.  相似文献   

15.
16.
17.
Specificity of infection by Mattesia trogodermae Canning was tested on six species of Trogoderma. Exposure of insects to similar numbers of spores indicated infections are always fatal in T. sternale Jayne, T. simplex Jayne, T. glabrum (Herbst) and T. inclusum LeConte. Rates of mortality (LT50's) were similar among the susceptible species and infection always reached 100 per cent in exposed insects. Trogoderma grassmani Beal and T. variabile Ballion were not infected at the dosages studied.

When eggs were seeded on to medium containing spores, the number of adults produced from such cultures was reduced by 50 per cent with an inoculation rate of 50 spores/g medium. Five thousand spores/g were necessary to infect all larvae before reaching the adult stage, however, this effect could be achieved with fewer total spores per jar if they were concentrated in the upper 1/5 of medium in the culture container. Infected larvar, when introduced into cultures, also cause infection of newly hatched larvae and subsequent reduction of adult production. A single infected larva reduced adult production by 25 per cent; 100 per cent infection of larvae was effected with 25–50 infected larvae per 50 g medium.

Adult T. glabrum males externally contaminated with Mattesia were able to transmit infective spores to females. Spore presence on the adults was determined by feeding the freeze-killed insects to larvae and inspecting the larvae for infection several weeks later. Male beetles were initially contaminated by being drawn to a corrugated cardboard inoculation device treated with pheromone ((Z)-14-methyl-8-hexadecen-1-ol) and dusted with Mattesia powder. Pheromone-baited inoculation devices resulted in contamination of 96 per cent of test insects placed in the arena whereas only 56 per cent picked up spores from inoculation devices containing only Mattesia spores (no pheromone).  相似文献   


18.
The effect of processing methods (cooking, frying and smoking) on the chemical composition of two marine fish (Sardinella sp., Dentex sp.) and a freshwater fish (Tilapia sp.) was studied.

The proximate compositions of the fish were similar to those of other fish reported in the literature. Processing per se had no effect on the composition of fish.

Smoking and cooking did not affect the fatty acid composition of the fish. The palm-kernel oil used in frying masked the fatty acid pattern in the fried fish. Freshwater fish contains high levels of n-6 fatty acids. However, similar amounts were found in the freshwater fish and the marine fish. This is probably due to the freshwater fish feeding on mosquito larvae.

The fish contained appreciable amounts of Na, Ca, P and Mg. Trace elements (Fe, Cu, Zn and As) were also determined.

There was no thiamine in flat sardine and tilapia, probably due to thiaminase activity. The content in Dentex sp. was low. Vitamins B2 and B6 were very low in all the fish.  相似文献   


19.
The effects of seed treatments, including cooking, popping, germination and flour air classification on several components of Amaranthus caudatus and A. cruentus seeds, including oil, sugars, fibre, minerals and vitamins were studied. The lipid, crude and dietary fibre, ash, and sugar contents were 71, 43, 140, 30 and 18 g kg?1 in raw A. caudatus and 85, 39, 134, 40 and 22 g kg?1 in raw A. cruentus seeds, respectively. Sucrose was the dominant sugar in the raw and thermal treated seeds of both species, while glucose and galactose were the dominant ones in the high protein and the germinated seed flours. Phosphorus, potassium, magnesium and calcium were the dominant minerals in the raw seeds of both species. Air classification increased the content of minerals by more than 35% while thermal treatments did not affect their content and germination increased the calcium and zinc contents. The ascorbic acid contents were 0.030 and 0.023 g kg?1 sample in raw A. caudatus and A. cruentus seeds, respectively. All the treatments reduced the ascorbic acid content, with a high effect for the air classification and the germinated seeds dried at 90 °C. The levels of vitamin B complex, including niacin, niacinamide, pyridoxine and riboflavin were increased in the high protein flour fraction (protein contents of these fractions of A. caudatus and A. cruentus were 263.9 g kg?1 and 246.6 g kg?1, respectively) and decreased in the thermal treated flours. Germination mostly increased the amounts of those vitamins while drying reduced their amounts. Copyright © 2005 Society of Chemical Industry  相似文献   

20.
本研究对不同树龄的日本落叶松进行了化学组成以及纤维形态分析,同时对相同蒸煮条件下不同树龄的落叶松原料的制浆性能和纸浆物理强度进行比较,以评价日本落叶松作为纸浆材的最佳轮伐树龄。结果表明,在相同制浆工艺条件下(用碱量20%(以Na_2O计);硫化度25%;液比1∶4;最高温度170℃;升温时间90 min;保温时间150 min,打浆度45°SR),树龄为9~29年的日本落叶松中,17年树龄日本落叶松比较适合作为纸浆材的来源,其中17年树龄的日本落叶松纤维长宽比为77. 66、壁腔比为1. 11、粗度为0. 188 mg/m;17年树龄的制浆细浆得率为42. 9%,卡伯值为25. 9,残碱为8. 14 g/L;制得手抄片的抗张指数81. 4 N·m/g,耐破指数6. 71 kPa·m~2/g,撕裂指数13. 7 mN·m~2/g,耐折度294次。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号