首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
A heterologous in vitro system, using zona‐intact sheep oocytes, was used to evaluate the relationship between sperm factors of Iberian red deer thawed epididymal sperm and the percentage of cleaved oocytes. Epididymal spermatozoa were recovered from six males, diluted with freezing extender and cryopreserved. After thawing sperm motility (SM) and acrosome and membrane integrities were evaluated. Again, these parameters were assessed after incubation in freezing extender at 37°C for 2 h. After cryopreservation the values for SM and acrosome and membrane integrities were high (~80, 80 and 70% respectively). However, these values significantly decreased after incubation (~59, 62 and 47% respectively). Red deer thawed epididymal sperm fertilized zona‐intact sheep oocytes, although the percentage of cleaved oocytes was low (~22%). No relationship was found between sperm parameters assessed after thawing and the percentage of cleaved oocytes. Likewise, any sperm parameter evaluated after incubation was assessed in relation to the percentage of cleaved oocytes. However, acrosome and membrane integrities were near to significance (p = 0.06 and p = 0.09 respectively). Then, we conducted a reduced model with these two variables and both were related to the percentage of cleaved oocytes (p = 0.02 and p = 0.04 respectively). Thus, acrosome and membrane integrities were related to the percentage of cleaved oocytes negatively and positively respectively. It was concluded that the classical parameters assessed in deer thawed sperm samples can be good predictors of the ability to fertilize zona‐intact sheep oocytes.  相似文献   

2.
We have approached the problem of refrigerated storage of epididymal sperm samples from red deer by comparing three options: storing the genital (testicles within the scrotum), diluting the semen in extender or diluting the semen in extender supplemented with an anti-oxidant. Twenty-nine pairs of testes were collected. Spermatozoa from one of each of the pairs were immediately recovered, and diluted to 400 × 106 sperm/ml in Tris-citrate-fructose with 20% egg yolk. Control group was stored as such, and Anti-oxidant group was supplemented with 0.8 m m vitamin C. The remaining epididymides and the diluted samples were stored at 5°C and spermatozoa were analysed at 0, 24, 96 and 192 h for: motility [computer-assisted semen analysis (CASA)], acrosomal integrity, sperm viability (eosine/nigrosine staining), normal tails and chromatin status [sperm chromatin structure assay (SCSA)]. In general, seminal quality decreased with storage time. Vitamin C supported progressive motility better at 24 h (median 42% vs 23% Control and 15% epididymis), reduced the incidence of tail abnormalities and protected chromatin. Storing the semen in the epididymis slowed down motility loss, but slightly increased the occurrence of tail abnormalities and viability was lower at 192 h. However, regarding chromatin status, sperm stored in the epididymis was protected similarly to those diluted in the medium supplemented with vitamin C. Although the differences between the three groups were small, there were some advantages in supplementing the extender with vitamin C. Besides, refrigerating the epididymis may be a good option when immediate processing is not available.  相似文献   

3.
Several methods are used to measure lipid peroxidation (LPO) in spermatozoa. The objective of this study was comparing the thiobarbituric acid reactive species (TBARS) method and the BODIPY 581/591 C11 (B581) and BODIPY 665/676 C11 (B665) fluorescent probes to measure induced peroxidative damage in thawed epididymal spermatozoa from Iberian red deer. Samples from three males were thawed, pooled, diluted in PBS, incubated at room temperature and assessed at 0, 3, 6 and 24 h under different experimental conditions: Control, hydrogen peroxide (H2O2) 0.1 mm or 1 mm , or tert‐butyl hydroperoxide (TBH) 0.1 mm or 1 mm . LPO was assessed by the TBARS assay [malondialdehyde (MDA) detection] and by the fluorescence probes B581 and B665 (microplate fluorimeter and flow cytometry). Increasing MDA levels were only detectable at 1 mm of TBH or H2O2. Both fluorescence probes, measured with fluorometer, detected significant increases of LPO with time in all treatments, except Control. Flow cytometry allowed for higher sensitivity, with both probes showing a significant linear relationship of increasing LPO with time for all oxidizing treatments (p < 0.001). All methods showed a good agreement, except TBARS, and flow cytometry showed the highest repeatability. Our results show that both B581 and B665 might be used for LPO analysis in Iberian red deer epididymal spermatozoa, together with fluorometry or flow cytometry. Yet, the TBARS method offered comparatively limited sensitivity, and further research must determine the source of that limitation.  相似文献   

4.
Egg yolk is a common component to sperm refrigeration for most of the deer species, the role of which is to protect sperm membranes against cold shock. In addition, there have been many studies of conservation of ejaculated semen from stags, but few have been reported for epididymal spermatozoa. This work was designed to investigate the combined effects of cooling rates (slow: 0.23 degrees C/min vs rapid: 4.2 degrees C/min) from room temperature to 5 degrees C, and egg-yolk concentration (0, 5 or 20%) in the extender on the survival of Iberian red deer epididymal spermatozoa refrigerated at 5 degrees C. Heterospermic sperm samples were diluted to a final sperm concentration approximately 400x10(6) sperm/ml with a Tris-citrate-fructose (TCF)-egg-yolk diluent. Sperm quality was in vitro judged by microscopic assessments of individual sperm motility [sperm motility index (SMI)], and of plasma membrane (hypo-osmotic swelling test) and acrosome (NAR) integrities. Our results first showed that the presence of egg yolk in the extender significantly improves (p=0.01) the viability and sperm motility after sperm dilution. In addition, acrosome and plasma membrane integrities post-refrigeration did not differ significantly between cooling procedures; however, the SMI differed significantly between cooling procedures (slow: 46.6% vs rapid: 50.0%; p=0.01). Our results also showed that sperm quality was significantly (p<0.01) affected by the combined effects of egg-yolk concentration and cooling procedure, being rapid cooling with 20% of egg yolk the most suitable combination for epididymal sperm refrigeration. In conclusion, egg-yolk improved red deer epididymal spermatozoa characteristics after dilution. Rapid cooling protocol using TCF with 20% egg-yolk significantly improved sperm motility of red deer epididymal spermatozoa after cooling.  相似文献   

5.
新疆某团饲养的塔里木马鹿群发生以腹泻、渐进性消瘦、难以治愈、侵害4岁以下鹿为主要特征的疫病,经流行病学调查、临床症状观察、病理病化、分子生物学诊断技术(PCR)、免疫酶标技术(ELASA)等先进技术的诊断,首次确诊为塔里木马鹿副结核病,现报告如下。  相似文献   

6.
旨在利用基因分型测序(genotyping by sequencing,GBS)技术对梅花鹿、马鹿及其杂交后代(F1、F2)基因组的SNP特征进行分析。本试验采用GBS技术对梅花鹿(63个)、马鹿(12个)及其杂交后代(F1代112个,F2代38个,未知类型个体1个)共226个个体的血液基因组DNA进行测序,并利用本实验室前期110只梅花鹿、197只马鹿和1只F1代杂交鹿的测序数据,以梅花鹿全基因组为参考序列进行比对分析。结果,226个个体共产生Clean data 322.683 Gb,平均每个样品1 427.802 Mb;将所有样本作为一个群体检测SNP变异,共检测出SNP位点23 943 582个,质控过滤后得到SNP位点31 630个。对31 630个SNPs使用最大似然(maximum likelihood,ML)法构建的分子进化树显示,梅花鹿、马鹿、F1及F2代区分明显。对梅花鹿和马鹿的SNPs进行比对分析,筛选出可用于鉴别马鹿、梅花鹿、F1、F2的物种特异SNP位点1 032个(马鹿特异SNP位点474个,梅花鹿特异SNP位点558个),计算结果显示,F1代个体包含马鹿特异SNPs的比例主要在40%~60%之间,F2代个体含马鹿特异SNPs的比例主要在10%~30%之间,马鹿个体中不含梅花鹿的特异SNPs,梅花鹿中55.49%的个体不含马鹿特异SNPs,17.34%的个体含马鹿特异SNPs的比例低于1%,13.29%的个体含马鹿特异SNPs的比例在1%~10%之间,其余个体含马鹿特异SNPs的比例为10%~20%(其中有一个个体含马鹿特异SNPs的比例为33.3%)。该研究为花马杂交鹿后代的鉴定提供了可靠标记,并定量估计了F1和F2代个体含马鹿特异SNPs的比例,马鹿个体中不含梅花鹿的特异SNPs,这对梅花鹿、马鹿及其杂交后代(F1、F2)的鉴别具有重要意义。  相似文献   

7.
本文对梅花鹿茸、马鹿茸不同部位氨基酸、总磷脂、钙、磷含量进行了分析,结果表明:梅花鹿茸、马鹿茸不同部位都含有丰富的氨基酸,其中含有7种以上的人体必需氨基酸。各个部位氨基酸的总量,必需氨基酸的含量及总磷脂的含量由基部到顶端逐渐增加,钙、磷的含量则由基部到顶端逐渐减少。  相似文献   

8.
The aim of this study was to evaluate whether the season of ejaculate collection influences seminal quality parameters of pre‐ and post‐freeze–thawing in Xinong Saanen bucks. Ejaculates were collected from eight bucks throughout the four seasons (spring, summer, autumn and winter) in a 12 months’ time period, identified in the Northern Hemisphere. Semen samples were evaluated by the combinations of conventional and Computer‐Assisted Sperm Analysis (CASA) when fresh and after frozen–thawed, respectively. The results clearly demonstrated that season of ejaculate collection influenced (p < 0.05) fresh semen quality. Highest semen quality was observed during autumn. On the contrary, undesirable indices (significantly lower, p < 0.05) were observed in winter as compared with the other remaining seasons. CASA has clearly shown the influences of seasonal variations on semen motility parameters. Furthermore, season of ejaculate collection was also found to influence sperm freezability. Semen characteristics after frozen–thawed followed a similar pattern with that of fresh ejaculate except in spring. The results revealed that sperm quality was higher (p < 0.01) in summer and autumn than in spring and winter. In conclusion, seasonal variation influences semen quality in Xinong Saanen bucks. In addition to summer and autumn, fresh ejaculates in spring can also be successfully used for AI. Sperm from ejaculates collected during summer and autumn are more suitable for cryopreservation. Hence, it is possible to increase the efficiency of goat breeding by manipulating the seasonal variations of semen quality for immediate AI and/or cryopreservation.  相似文献   

9.
为了探讨塔里木马鹿(Cervus elaphus yarkandensis)干旱环境适应相关基因的结构特征和相关功能,从前期的塔里木马鹿全基因组重测序结果中,筛选获得塔里木马鹿过氧化物氧化还原酶3(thioredoxin-dependent peroxide reductase,PRDX3)基因的序列,对该基因在塔里木马鹿不同组织中的表达情况进行分析,同时对塔里木马鹿PRDX3基因编码区(CDS)序列进行克隆测序,运用相关软件进行同源性比对、构建系统进化树及生物信息学分析。结果显示,塔里木马鹿PRDX3基因在肾脏组织中的基因表达水平极显著高于肺脏和肝脏组织(P<0.01);塔里木马鹿PRDX3基因CDS序列长660 bp。同源性比对和系统进化树分析结果表明,塔里木马鹿与白尾鹿(GenBank登录号:XM_020875097.1)同源性最高,且遗传距离最近;与褐家鼠(GenBank登录号:NM_022540.1)同源性最低,且遗传距离最远。塔里木马鹿PRDX3蛋白分子质量为24.42 ku,由220个氨基酸组成,不稳定系数为25.36,理论等电点(pI)为5.82,脂溶系数为85.50,总平均亲水性为-0.05,存在O-糖基化位点,具有丰富的磷酸化位点,但是不存在N-糖基化位点、跨膜区及信号肽,最可能位于线粒体中,二级结构和三级结构主要由α-螺旋和无规则卷曲组成,包含PRX_Typ2cys超家族保守结构域,与多种蛋白存在相对较强的相互作用。本研究为后续的塔里木马鹿功能基因的研究奠定基础。  相似文献   

10.
人为干扰会对野生动物种间关系、个体适合度、群落结构和繁殖成功率等产生中长期的影响。因此,研究野生动物反干扰行为对于我们认识该物种对其生境的行为适应和进化机制具有重要意义。2017年11—12月在内蒙古贺兰山国家级自然保护区内通过建立多元逻辑斯蒂回归模型研究了岩羊(Pseudois nayaur)、马鹿(Cervus elaphus)的反干扰策略,本研究共设置33条样线,记录了10种在人为干扰下可能会影响岩羊、马鹿反应行为的变量,经模型分析发现影响岩羊反应行为的变量有5种,影响马鹿反应行为的变量有4种,共同影响因子分别是干扰源、性别、头的朝向和地形特征,而植被类型则只对岩羊产生影响。最后根据逻辑模型得出的数据计算发生比,从而了解各个分类变量与反应行为的关系。  相似文献   

11.
马鹿是非常重要的物种资源,由于栖息地的流失和人为干扰进行近亲繁殖等导致野生马鹿数量急剧减少,而家养马鹿多经过改良,因此马鹿的纯种数量锐减。对马鹿进行分子遗传学研究不仅可以加深人们对马鹿起源和物种形成的认识,还能帮助开展遗传多样性保护研究。随着高通量测序技术、分子生物学和生物信息学的迅速发展,马鹿的起源进化研究已发展到全基因组水平,并取得了一定的成果。马鹿的起源进化研究从最初对体态外貌和染色体核型的研究逐渐发展到对DNA序列与生理指标的研究。文章回顾了近年来国内外对马鹿起源进化和遗传多样性方面的研究,从起源时间、起源地和迁徙路线等方面揭示了马鹿的演化历史,介绍了父系、母系和常染色体研究方面分析了马鹿遗传多样性选取的不同分子标记,为进一步揭示马鹿种群的遗传变异、分化情况、迁徙路线和系统发育关系等提供基础信息,同时为马鹿遗传资源的利用和保护以及马鹿产业的良性发展提供重要的借鉴与参考。  相似文献   

12.
为探讨不同浓度Ca2+对马鹿精子体外获能的影响,本研究以塔里木马鹿冻融精子为试验材料,将精子分别悬浮于含不同浓度Ca2+(0、1.1、2.2、3.5、5.0 mmol/L)的台氏液(sp-TALP液)中,在培养0、2、4 h时,采用金霉素(CTC)染色法评价精子获能状态,采用SDS-PAGE分离精子膜蛋白,进行免疫印迹分析,检测酪氨酸磷酸化蛋白的表达水平。结果表明,Ca2+浓度为1.1、2.2 mmol/L有利于精子活力的维持(P<0.05),精子获能率极显著高于对照组和高浓度组(3.5、5.0 mmol/L;P<0.01),精子存活时间最长(P<0.01),但高浓度Ca2+(5.0 mmol/L)对精子活力具有显著抑制作用(P<0.05),精子获能率极显著低于低浓度组(P<0.01),精子存活时间最短(P<0.01);另外,随着培养时间的推移精子发生酪氨酸磷酸化蛋白的表达水平有所不同,培养2、4 h时,1.1 mmol/L组精子蛋白磷酸化水平极显著高于其他各组(P<0.01),高浓度Ca2+(3.5、5.0 mmol/L)组酪氨酸磷酸化蛋白的表达水平极显著下降(P<0.01)。结果表明,塔里木马鹿精子体外获能所需的适宜Ca2+浓度为1.1 mmol/L,且获能过程中Ca2+的存在是必要的。  相似文献   

13.
3-氨基三唑与过氧化氢共同处理对家蚕滞育发动的影响   总被引:1,自引:0,他引:1  
赵林川 《蚕业科学》2004,30(3):319-322
研究有效阻止家蚕滞育发动的措施发现 :在家蚕滞育发动期间 ,仅用过氧化氢酶 (catalase ,CAT)的专一性抑制剂 3 氨基三唑 (3 amino 1,2 ,4 triazole ,AT)处理滞育性蚕卵仍不能阻止家蚕滞育发动 ;但先用AT处理抑制CAT活性后 ,再用H2 O2 处理可有效阻止家蚕滞育发动。  相似文献   

14.
This study aimed to evaluate the effect of the exogenous recombinant bovine somatotropin (rbST) on plasma concentrations of insulin‐like growth factor I (IGF‐I), insulin and semen quality of bulls. Twenty bulls (Aberdeen Angus and Brangus) were divided by breed into two groups. Placebo group was injected with NaCl 0.9% (s.c.) and treatment group with rbST (s.c., 500 mg) at days 0 and 14 of the experiment. Immediately after semen collection, blood samples were taken on days 0, 14, 28, 42 and 56 of the experiment. Semen was also collected on day 70 of the experiment. Evaluation of sperm motility was performed at pre‐freezing and post‐thawing stage, whereas assessment of sperm membrane integrity was performed after freezing and thawing. Analysis of data revealed that the effect of treatment and treatment‐by‐collection day on plasma concentrations of IGF‐I and insulin was not significant. However, mean plasma concentrations of IGF‐I and insulin were affected (p < 0.0001) by days of blood sampling. Effect of treatment and treatment‐by‐collection day on motility of spermatozoa was similar (p > 0.05) at pre‐freezing and post‐thawing stage. Intactness of plasmalemma and tail membrane of spermatozoa at post‐thawing stage was higher (p < 0.05) in rbST‐treated group than in control. In conclusion, rbST did not affect plasma concentrations of IGF‐I and insulin, however, it did improve post‐thaw sperm membrane integrity.  相似文献   

15.
为探索选育高异黄酮含量红三叶(Trifolium pratense L.)新种质材料的可行途径,本研究测定和林格尔县实验地中300株红三叶地上部分的异黄酮含量,采用K-means聚类分析方法,将不同异黄酮含量红三叶聚类为4个类群(T1~T4),同时对4个红三叶类群进行形态特征进行观测,以及对各农艺性状和产量指标进行测定。结果表明:300株红三叶异黄酮含量介于15.65~34.16 mg·g-1,平均含量为24.88 mg·g-1。不同异黄酮含量的红三叶类群在形态特征、农艺性状、草产量等方面具有显著性差异,其中高异黄酮含量红三叶群体占300株的18.67%,平均含量为29.61 mg·g-1,具有绝对株高和自然株高差值大于15 cm(平卧型)和叶片面积小于350 mm2的形态特征;同时绝对株高、草产量也显著更高(P<0.05)。本研究为红三叶高产优质栽培和品种选育奠定了基础。  相似文献   

16.
浅谈鹿育种方向和繁育体系形式及配套系杂交   总被引:1,自引:4,他引:1  
对我国已家养 5代及 5代以上、并已人工育成品种品系或类型的马鹿和梅花鹿的现代育种方向、繁育体系形式及配套系杂交进行了较为全面地阐述  相似文献   

17.
The objective of this study was to estimate the prevalence of and risk factors for pathological conditions of the reproductive organs in stray dogs under tropical conditions. Three hundred and eighteen dogs were examined post-mortem in the period from 1 July 2002 to 30 June 2003. Before killing, a blood sample (from the cephalic vein) for testosterone assay was taken. Pathological conditions of the reproductive organs were found in 135 of the dogs (42.5%) and in 175 of the testes (64.8%). The most frequent pathologies found were testicular degeneration, cryptorchidism, testicular hypoplasia and testicular tumours (in 15.1%, 6.6%, 6.6% and 5.4% of the dogs and 15.1, 4.6, 6.0 and 3.5 of the testes, respectively). Transmissible venereal tumour (TVT) was seen in 5.4% of the dogs. Testicular degeneration was more common in old dogs and underweight dogs (p < 0.05). Testicular tumours were 14.3 times more common in cryptorchid dogs. Age was another important factor for the development of testicular tumours (p < 0.05). Lower levels of testosterone concentration (p < 0.05) were observed in dogs with advanced testicular degeneration (0.7 +/- 0.8 nM), dogs with hypoplastic testicles (0.8 +/- 0.9 nM) and dogs with one degenerated and one retained testis or with bilateral cryptorchidism (1.2 +/- 0.9 nM) compared to dogs with one or two normal testes (7.0 +/- 5.5 nM). Testicular volume and weight were significantly lower in degenerated, hypoplastic and retained testes compared with the contralateral normal testis. Some spermatogenic activity was found in three of the retained testes, producing oligozoospermic smears with a high percentage of sperm abnormalities. No comparable epidemiological data about male pathological conditions of the reproductive organs in the dog is available. The prevalence found in this study, yet, appears high.  相似文献   

18.
在能量浓度相近,粗蛋白水平一致的前提下,研究不同精粗比全混合日粮(TMR)对休闲期雄性梅花鹿尿中嘌呤衍生物(PD)排泄量及体增重等生产性能的影响。采用4x4拉丁方设计,全混合日粮精粗比分别是A组65:35,B组55:45,C组45:55,D组35:65。试验结果表明:TMR精粗比对休闲期梅花鹿尿囊素、尿酸、PD日排出量影响显著(P〈0.05),对黄嘌呤+次黄嘌呤、肌酐日排出量影响不显著(P〉0.05),精粗比55:45时尿囊素日排出量最大,其他3组差异不显著(P〉0.05),尿酸、PD日排出量在精粗比45:55的C处理组最大,其他3组差异不显著(P〉0.05);TMR精粗比对休闲期梅花鹿饲料单价、试验期饲料成本、平均日增重、体增重、料肉比及体增重成本均存在明显影响,特别是平均日增重差异显著(P〈0.05),每千克体增重饲料成本相差极大,精粗比35:65约是精粗比45:55的2倍。  相似文献   

19.
The addition of 0.5% (v/v) of Equex STM Paste (Nova Chemical Sales, Scituate Inc., MA, USA), whose active ingredient is sodium dodecyl sulphate (SDS), to a Tris–egg yolk extender was demonstrated to improve the longevity of frozen–thawed dog spermatozoa during in vitro incubation at 38°C. The aim of the first experiment was to compare the effects of two SDS‐containing compounds, Equex STM Paste and Equex Pasta (Minitüb, Tiefenbach, Germany), when added to a Tris–egg yolk based extender, on the post‐thaw longevity of dog spermatozoa, as well as on the intracellular Ca2+ concentration of spermatozoa, during post‐thaw incubation at 38°C. The post‐thaw sperm survival and longevity, as well as the quality of the sperm movement, were significantly better when using Equex STM Paste. Such prolonged sperm longevity, however, was associated to a higher intracellular Ca2+ concentration in a large subpopulation of the live spermatozoa. A second experiment was aimed to evaluate the effects of sperm dilution immediately post‐thaw with a Tris buffer containing glucose or fructose. The two Tris buffers were no different for any of the sperm parameters studied. The aim of a third experiment was to evaluate the sperm longevity, motility patterns and intracellular Ca2+ concentration of cryopreserved dog spermatozoa during post‐thaw incubation in capacitating conditions [canine capacitating medium (CCM) with or without 5 μg/ml of heparin]. Heparin had no significant effects on any of the sperm parameters evaluated. During the first 8 h of incubation, the majority of the live spermatozoa had a high intracellular Ca2+ content. However, after 8–10 h of incubation, it had significantly declined. The highest proportion of fast motile sperm, and the highest curvilinear velocity, average path velocity and amplitude of lateral head displacement for the total motile sperm were observed during the 2–4‐h incubation period. It was concluded that: (a) the addition of 0.5% (v/v) of Equex STM Paste to a Tris–egg yolk based extender significantly improved the post‐thaw longevity of dog spermatozoa, but the same concentration of Equex Pasta had no significant beneficial effects; (b) sperm dilution after thawing with a Tris buffer containing glucose or fructose made no difference in post‐thaw sperm longevity; (c) the addition of 5 μg/ml of heparin to CCM had no significant capacitating effects on frozen–thawed dog spermatozoa.  相似文献   

20.
The objective of this study was to evaluate the effects of different molting methods on postmolt production, plasma corticosterone levels, and antibody production to SRBC for the welfare of laying hens. This experiment was conducted with 120 IGH-type Brown laying hens (70 wk of age), randomly divided into 3 experimental groups. The hens in one group were fed a whole-grain barley diet during the first 10 d (WB diet). On d 11, hens consumed 100 g of layer diet/d until d 28. In the second group, hens were fed a Zn diet containing 10,000 mg/kg of Zn as ZnO for 10 d (Zn diet). Hens were then provided 100 g of a layer diet from d 11 to 28. In the third group, feed was withdrawn for 10 d, and on d 11 hens were fed a cracked corn diet ad libitum until d 28 (California method; CAL diet). Hens in all groups were returned to the layer diet ad libitum on d 29. Egg weight was lower in the Zn treatment than in the other treatments. Feed intake and plasma corticosterone levels were higher and antibody production was lower in the CAL treatment than in the WB and Zn groups. The FCR was better in the WB than in the Zn group. Mortality, egg production, and egg quality were not significantly different among the molting methods. As a result, the WB molting program was the best method for postmolt production among the programs examined.  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