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1.
PURPOSE: To evaluate orbital blood flow velocities with Doppler sonography in patients with acute unilateral optic neuritis. MATERIALS AND METHODS: Orbital Doppler sonography was performed in 20 patients with acute unilateral optic neuritis. Optic neuritis was diagnosed by a neurologist on the basis of clinical presentation, presence of decreased visual acuity, and assessment of visual evoked potentials. The peak systolic and end diastolic velocities and the resistive index were measured in the ophthalmic and central retinal arteries of both orbits. The values obtained from affected and unaffected orbits were compared by using the paired t test. RESULTS: The peak systolic and end diastolic velocities in the ophthalmic artery were significantly increased in the affected orbits (for peak systolic velocity P <.001, for end diastolic velocity P <.05). Resistive indexes in the ophthalmic arteries did not differ (P >.05). The difference between the peak systolic and end diastolic velocities and resistive indexes in the central retinal arteries of affected and normal eyes was not statistically significant (P >.05). CONCLUSION: Peak systolic and end diastolic velocities in the ophthalmic artery are increased in patients with acute optic neuritis.  相似文献   

2.
PURPOSE: To examine how an internal carotid artery (ICA) stenosis influences the orbital blood velocity and to determine which velocity parameters are most useful. MATERIAL AND METHODS: The study group comprised 94 randomly selected patients examined with orbital US; most of the patients had a carotid artery stenosis. There were 58 men and 36 women, ranging in age from 22 to 88 years with a mean age of 63.1 years. The ICA stenosis grade was determined with carotid US. Peak systolic (Vp) and end-diastolic blood velocities, systolic acceleration, mean velocity, pulsatile index (PI) and resistance index (RI) were measured within the central retinal artery (CRA) and the ophthalmic artery (OA), and peak velocity was measured within the central retinal vein (CRV). The area under the ROC curve was used to compare the outcome of diagnostic tests. RESULTS: Only a severe (> or =80%) ICA stenosis decreased orbital blood velocity significantly, while milder stenoses did not cause significant flow decrease or side differences. According to ROC curve analysis, the threshold values giving the highest accuracy in detecting a > or =80% ICA stenosis were Vp < or =0.08 cm/s for the CRA and Vp < or =0.14 cm/s for the OA. The sensitivities for detecting a > or =80% ICA stenosis were 45% for Vp CRA and 60% for Vp OA. Systolic acceleration also decreased in severe stenoses, but RI, PI and velocity in the CRV did not correlate with ICA pathology. Reversal of OA flow was seen in 92% of ICA occlusion and in 47% of severe ICA stenosis. CONCLUSION: Orbital Doppler combined with carotid Doppler can be helpful in the diagnosis of the ocular ischaemic syndrome and in the evaluation of whether the symptoms are related to occlusion of the ophthalmic or central retinal vessels or are a consequence of carotid artery stenosis.  相似文献   

3.
BACKGROUND AND PURPOSE: In severe carotid stenosis, blood supply via the poststenotic internal carotid artery (ICA) and collateral pathways determine cerebral perfusion. We investigated whether poststenotic flow on transoral carotid ultrasonography (TOCU) is predictive of cerebral hemodynamics. METHODS: Eighty-eight patients with unilateral carotid stenosis underwent TOCU to analyze blood flow velocity and poststenotic diameter of the extracranial ICA. Intracranial collaterals and cerebral hemodynamics were assessed with selective angiography and single photon emission CT. RESULTS: Poststenotic diameter (P <.0001) and velocities (peak systolic velocity [PSV], time-averaged mean velocity [TMV], end-diastolic velocity [EDV]; all P < or = .009) decreased with stenotic severity. Poststenotic diameter was correlated with PSV (r=0.36, P=.0005), EDV (r=0.32, P=.002), and TMV (r=0.39, P=.0001). Poststenotic flow was significantly lower with collateral pathways than without pathways (P < or = .02) and significantly decreased as the number of the collaterals increased (P <.0001). Flow <5 mL/s indicated collaterals (81% sensitivity, 80% specificity). When flow was <5 mL/s, the asymmetry index in the middle cerebral artery (MCA) territory was significantly low during rest (P=.003) and after acetazolamide challenge (P=.006). Poststenotic flow velocity was associated with baseline (P=.007) and postacetazolamide (P=.0009) MCA asymmetry indexes. CONCLUSION: Poststenotic ICA flow measured with TOCU reflects collateral flow and cerebral hemodynamics in patients with severe carotid stenosis. This technique may provide new parameters for screening patients with hemodynamically significant carotid stenosis.  相似文献   

4.
PURPOSE: To examine the variability of Doppler measurements along the extra-cranial courses of the nondiseased common carotid artery (CCA) and internal carotid artery (ICA) and determine the effect of this variability on assessment of carotid arterial stenosis. MATERIALS AND METHODS: During the study period, 580 patients were referred for carotid arterial ultrasonography (US), including Doppler measurements of flow velocities in the proximal, middle, and distal portions of the CCA, in the bulb, and in the proximal and distal portions of the ICA. Eighty-five patients (average age, 59 years) with normal ICAs and CCAs formed the cohort for this study. RESULTS: The range of peak systolic velocity (PSV) measurement (maximum minus minimum) averaged 20 cm/sec +/- 13 in the CCA and 15 cm/sec +/- 13 in the ICA. ICA/CCA velocity ratios varied, depending on the CCA measurement location. In five arteries, PSV ratios exceeded a threshold of 1.8 (suggesting > or = 60% stenosis); in 23 arteries, end diastolic velocity ratios exceeded a threshold of 2.4 (also suggesting > or = 60% stenosis). Right-to-left CCA PSV ratios were abnormal in up to 26 patients (suggesting > 50% ICA stenosis), depending on where CCA measurements were obtained. When the CCA ratios were obtained at the same level, 16 were in the abnormal range. CONCLUSION: Variability of Doppler measurements in the CCA and ICA in patients without visible disease is substantial and could lead to inaccuracies in carotid arterial stenosis assessment.  相似文献   

5.
糖尿病眼底动脉血流动力学的彩色多普勒超声研究   总被引:1,自引:0,他引:1  
目的:探讨糖尿病眼底血流动力学的变化。方法:彩色多普勒超声检测糖尿病患者67例和正常对照者40例的视网膜中央动脉(central retinal artery,CRA)、睫状后动脉(posterior ciliary artery,PCA)的收缩期血流峰值速度(PSV)、舒张末期血流速度(EDV)、阻力指数(RI),分析糖尿病视网膜病变(diabetic retinopathy DR)和糖尿病不伴视网膜病变(non-diabet-ic retinopathy,NDR)时其血流动力学的改变以及正常人不同年龄组血流参数的变化规律。结果:正常人不同年龄组间的PSV差异有显著性意义(P<0.05);不同年龄组间EDV、RI差异无显著性意义(P>0.05)。与对照组相比较,糖尿病患者PCA、CRA的血流速度减低,阻力指数增高,差异有显著性意义;且在无视网膜病变时不仅CRA而且PCA也存在血流动力学的异常。结论:彩色多普勒超声对糖尿病眼底动脉血流动力学变化的显示具有较高临床价值。  相似文献   

6.
OBJECTIVE: The aim of this study is to search sonographically for morphological and hemodynamic changes in hepatic and splanchnic vasculature of alcoholic patients having no signs of hepatic damage, and compare these with normal healthy subjects. METHODS: Thirty alcohol-dependent patients and 30 control subjects with no alcohol problem or hepatic impairment were included in the study. All patients were evaluated by gray-scale and spectral Doppler ultrasound. The diameter of the portal vein, portal venous velocity, peak systolic and end diastolic velocities of hepatic and superior mesenteric arteries were assessed. RI, PI and systolic/diastolic velocity ratios were also calculated. RESULTS: Portal vein cross-sectional area was greater in alcoholic patients compared to control group (P = 0.0012). Portal vein velocity, hepatic artery peak systolic and end diastolic velocity, superior mesenteric artery peak systolic and end diastolic velocity were significantly greater in alcoholic patients than in control group (P < or = 0.001). No statistically significant difference was detected between other parameters evaluated. CONCLUSION: In alcohol-dependent patients, some hemodynamic and morphologic changes occur in hepatic and splanchnic circulation, even before the signs of hepatic damage develop. These changes can be detected by means of Doppler and gray-scale sonogrsphy.  相似文献   

7.
BACKGROUND AND PURPOSE: Various Doppler criteria have been used to predict hemodynamically significant carotid stenosis. This study was performed to elucidate whether hemodynamically significant stenosis can be predicted indirectly by the blood flow velocity in the common carotid artery (CCA) measured with duplex ultrasonography in patients with unilateral stenosis of internal carotid artery (ICA). METHODS: Eighty-five patients who were scheduled to undergo carotid endarterectomy for unilateral stenosis of ICA origin were analyzed. The flow velocities and their side-to-side ratios in the CCA were calculated. The flow velocities in the CCA were measured with conventional ultrasonography and poststenotic blood flow with transoral carotid ultrasonography. Cerebral angiography was performed to evaluate the intracranial collateral flow. RESULTS: Among the absolute values and side-to-side ratios of Doppler flow velocities in the CCA, the end diastolic flow velocity (EDV) ratio in the CCA best correlated with the residual lumen area (r = 0.35; P = .0009), stenosis of diameter (r = 0.48; P < .0001), and poststenotic flow (r = 0.60; P < .0001). EDV ratios in the CCA were significantly lower in patients with collateral pathways (anterior communicating artery, P = .0005; posterior communicating artery, P = .004; ophthalmic artery, P < .0001; leptomeningeal collateral, P = .004). The optimal threshold value of the EDV ratio in the CCA for the presence of intracranial collateral flow and stenosis of diameter > or = 70% was 1.2. Those for tight stenosis in a cross-sectional area >95%, the reduction of poststenotic flow, and poststenotic narrowing were 1.4, 1.5, and 1.6, respectively. CONCLUSION: The EDV ratio in the CCA appears to be an additional parameter for predicting hemodynamically significant stenosis in patients with unilateral ICA stenosis.  相似文献   

8.
魏玉杰  刘惠亮  张敏  田蕾 《武警医学》2010,21(12):1020-1022
 目的 观察厄贝沙坦对轻中度高血压颈动脉内膜中层厚度及动脉弹性的影响.方法 选取符合入选标准的轻中度原发性高血压106例,应用彩色多普勒超声检测颈总动脉内膜中层厚度(carotid intima-media thickness,IMT),脉搏波速度测定仪同时检测颈动脉-桡动脉(carotid-radial pulse wave velocity,C-RPWV)、颈动脉-股动脉(carotid-femoral carotid-radial ,C-FPWV)的脉搏波速度.给予以厄贝沙坦为基础的降压治疗,根据患者的血压反应加用小剂量氢氯噻嗪,12周后超声复查颈动脉内膜中层厚度及脉搏波速度.结果 与治疗前相比,治疗后收缩压(SBP)和舒张压(DBP)均明显下降(P<0.05);IMT显著减少(P<0.01);C-RPWV、C-FPWV明显减慢(P<0.01).结论 厄贝沙坦除能有效降低血压外,还能改善动脉重构.  相似文献   

9.
Dinkel HP  Triller J 《Radiology》2002,222(3):709-714
PURPOSE: To determine whether criteria for screening patients with sickle cell anemia for stroke established with a nonimaging transcranial Doppler ultrasonographic (US) technique are applicable to studies performed with a transcranial Doppler US imaging technique. MATERIALS AND METHODS: One hundred sixty-eight examinations in 66 children were performed for sickle cell stroke screening. Children were examined with nonimaging and imaging transcranial Doppler US techniques on the same day, for a total of 84 paired examinations. The time-averaged maximum mean velocity (V(mean)) and resistive index (RI) were calculated in the middle cerebral arteries, bifurcations of the distal internal carotid arteries, distal internal carotid arteries, anterior cerebral arteries, posterior cerebral arteries, and basilar arteries. The maximum systolic velocity (V(max)) was evaluated in the distal internal carotid arteries and middle cerebral arteries. V(mean), V(max), and RI measurements were subjected to repeated-measures multivariate analysis of covariance, and the Pearson product moment correlation was used for middle cerebral artery velocity, age, and hemoglobin. RESULTS: V(mean) measurements obtained with nonimaging and imaging techniques varied substantially for the bifurcation of the distal internal carotid artery, the posterior cerebral artery, and the basilar artery. Substantial differences were found in RIs for every vessel. Examination time was shorter with the nonimaging technique. CONCLUSION: V(mean) measurements in the middle cerebral artery, distal internal carotid artery, and anterior cerebral artery did not vary substantially between nonimaging and imaging transcranial Doppler US. RI data did not yield comparable measurements.  相似文献   

10.
PURPOSETo provide transcranial color-coded duplex flow-velocity data for the basal cerebral arteries in patients with unilateral flow-restrictive extracranial carotid artery disease, and to compare these data with the flow velocities obtained in healthy control subjects.METHODSTranscranial color-coded duplex sonography was performed in 78 patients with different patterns of cross flow through the anterior and posterior communicating arteries associated with unilateral obstruction (70% to 100%; 46 stenoses and 32 occlusions) of the internal carotid arteries. Peak systolic, mean, and end diastolic velocities were measured in the anterior, middle, and precommunicating and postcommunicating posterior cerebral arteries. These measurements were compared with the values obtained in 125 age- and sex-matched health control subjects.RESULTSPatients with anterior communicating artery cross flow to the middle cerebral artery (63%) had increased peak velocity in the anterior cerebral artery and decrease peak velocity in the middle cerebral artery on the obstructed (ipsilateral) side, and increased peak velocity in the anterior cerebral artery on unobstructed (contralateral) side. Patients with anterior communicating artery cross flow to the pericallosal artery (19%) had increased contralateral peak systolic velocity and mean anterior cerebral artery velocities. Patients without anterior communicating artery cross flow (18%) had normal peak velocities in the anterior and middle cerebral arteries. Patients with posterior communicating artery cross flow (42%) had ipsilaterally decreased peak systolic and mean middle cerebral artery velocities and increased peak velocities in the precommunicating posterior cerebral artery. Patients without posterior communicating artery cross flow (58%) had ipsilaterally decreased peak systolic and mean middle cerebral artery velocities.CONCLUSIONOur findings suggest that typical abnormalities of basal cerebral artery flow velocities occur in patients with unilateral 70% to 100% obstruction of the internal carotid arteries resulting in different patterns of cross flow through the circle of Willis.  相似文献   

11.
Ultrasonography (US) of the head and neck is a convenient but operator-dependent screening tool for detection and diagnosis of neurovascular occlusive disease. In US examination of the extracranial carotid arteries, stenosis is most commonly graded according to the peak systolic Doppler velocity in the region of maximal luminal narrowing rather than according to the percentage of atheromatous plaque occupying the lumen. However, the peak systolic velocity is not always reliable in estimation of the degree of stenosis. General diagnostic pitfalls include technical difficulties with scanning, failure to review the spectral waveform patterns, the presence of additional stenotic lesions, and anatomic variants. Specific examples of pitfalls include tandem lesions, differentiation of pseudo-occlusion from true total occlusion, pseudonormalization of velocities in cases of very severe stenosis, lesions of the carotid artery origin or aortic valve, progression of subclavian steal, underestimation of severe stenosis due to heavily calcified plaque, a persistent trigeminal artery, and contralateral carotid artery stenosis. Although conventional angiography remains the standard of reference for assessment of carotid artery disease, recognition of these common sources of error in US can improve the accuracy of this noninvasive test in diagnosis of carotid artery occlusion.  相似文献   

12.
战斗机飞行员脑血流动力学的研究   总被引:2,自引:1,他引:1  
目的 探讨战斗机飞行员脑血流动力学的特点.方法 试验对象分为3组:战斗机飞行员组(40名)、运输机飞行员组(30名)和健康对照组(30名),分别用2 MHz多普勒探头检测颅内各动脉的血流速度及搏动指数.结果 战斗机飞行员组与其他两组比较,颅内动脉各期血流速度呈对称性增快,差异均有显著性意义(P<0.01),以大脑中动脉、大脑后动脉、椎动脉、基底动脉和眼动脉血流速度增快明显.搏动指数虽有升高,但无统计学意义.运输机飞行员组与健康对照组相比,各期血流速度差异不显著.结论 战斗机飞行员颅脑动脉高血流流速是一种代偿性生理变化,在飞行鉴定时应引起重视.  相似文献   

13.
In a preliminary study, nine infants with a clinically determined diagnosis of brain death were examined with duplex pulsed Doppler ultrasonography (US) through the anterior fontanelle. Flow velocity measurements were made in the intracranial internal carotid artery and anterior cerebral artery. Resistive index (RI) was calculated in each patient and used as an indicator of diastolic flow. Eight of nine infants showed markedly elevated RI (100%-191%) with reversal of diastolic flow. One infant had low RI (42%-58%) with preserved systolic and diastolic flow until death. The authors believe that the elevation of RI with diastolic flow reversal seen in these patients is a reflection of increased intracranial pressure and is a sign of poor prognosis when present on serial examinations. Cranial duplex pulsed Doppler US is a useful, noninvasive tool in the diagnosis of brain death in infants but must be carefully correlated with clinical examination and other diagnostic tests.  相似文献   

14.
PURPOSE: To determine the effect of variability of common carotid arterial (CCA) velocities on velocity ratios used to assess internal carotid arterial (ICA) stenosis. MATERIALS AND METHODS: Doppler ultrasonographic (US) velocity measurements were obtained at three levels in the CCA and in the carotid bulb and ICA in all patients referred for carotid US between September 1996 and October 1997. Only ICAs (n = 98, in 57 patients) without ipsilateral CCA disease at angiography were analyzed. The range of CCA peak systolic velocities (PSVs) and end diastolic velocities (EDVs) and velocity ratios were calculated for each CCA measurement. For each ICA/CCA velocity ratio, receiver operating characteristic analysis was performed. RESULTS: CCA PSV and EDV ranges averaged 23.1 cm/sec +/- 15.7 (SD) and 5.1 cm/sec +/- 3.6, respectively. For a given side, the difference averaged 1.0 +/- 1.3 for PSV ratios and 2.7 +/- 6.9 for EDV ratios, depending on where CCA measurements were taken. By using a threshold of 60% stenosis as indication for endarterectomy, variability in CCA velocities could have altered recommendations in 16 (28%) of 57 patients. Receiver operating characteristic analysis showed that ratios made by using the three CCA velocities or their mean were not significantly different. CONCLUSION: Variability in velocity measurements along the course of the CCA in patients with ICA disease can be substantial and can result in inaccuracies in assessment of carotid stenosis.  相似文献   

15.
PURPOSE: To validate fast magnetic resonance (MR) flow mapping with intravascular Doppler flow measurements in vitro and in patients with nonstenotic and stenotic coronary artery bypass grafts. MATERIALS AND METHODS: MR and Doppler flow measurements were performed in a small-diameter flow phantom with physiologic flow conditions and at baseline and during adenosine stress in 27 grafts in 23 patients, who were scheduled for cardiac catheterization. At invasive analysis, the grafts were divided into those with stenosis of less than 50% (nonstenotic) and those with stenosis greater than or equal to 50% (stenotic). In vitro velocity values and velocity values in nonstenotic and stenotic grafts were compared with linear regression analysis, and the in vitro interstudy variability was determined. RESULTS: Excellent correlations in average peak velocity (r = 0.99, P <.001) and diastolic peak velocity (r = 0.99, P <.001) were demonstrated in vitro between MR and Doppler flow measurements, with less than 5% interstudy variability. MR and Doppler flow measurements revealed good correlations in peak velocity and velocity reserve both in nonstenotic (n = 20) (average peak velocity: r = 0.81, P <.001; diastolic peak velocity: r = 0.83, P <.001; velocity reserve: r = 0.56, P =.010) and stenotic (n = 7) (average peak velocity: r = 0.83, P <.001; diastolic peak velocity: r = 0.78, P =.001; velocity reserve: r = 0.70, P =.078) grafts. CONCLUSION: Fast MR flow mapping provides noninvasive measures of peak velocity and velocity reserve, which closely correlate with Doppler values both in vitro and in nonstenotic and stenotic grafts.  相似文献   

16.
目的通过超声检查评价波依定对高血压颈动脉粥样硬化的干预,探讨颈动脉超声检查在降压药物疗效评估中的作用。方法检查80例高血压患者服药前后收缩压、舒张压、平均IMT、最大IMT、动脉粥样硬化等级评分指标水平变化。结果经治疗后收缩压、舒张压、平均IMT、最大IMT、等级评分指标水平较治疗前均明显下调,与治疗前比较有显著性差异(P〈0.05或P〈0.01)。结论颈动脉超声可以检测动脉粥样硬化病理变化的改善,可用于临床药物评价。  相似文献   

17.
PURPOSE: To determine the changes of multiple hemodynamic parameters and pulse wave contour in pure aortic regurgitation (AR) and to present a new indicator of the severity of AR (shrink ratio of proximal common carotid artery). MATERIAL AND METHODS: The sonograms of 42 patients (31 M, 11 F; 16-68 years) with pure AR and 18 control subjects (15 M, 3 F; 20-47 years) were assessed for velocities and indices, and change of pulse wave contour (bisferious pattern, zero level and retrograde diastolic flow) in each carotid artery. Shrink ratio (maximum diameter-minimum diameter/maximum diameter) of each proximal common carotid artery was calculated. RESULTS: Bisferious waveforms seen in patients with AR grade 1, grade 2, and grade 3-4 were 66%, 83%, and 88%, respectively. Diastolic reversed flow was determined in 7 (39%) of 18 patients with AR grade 3-4. Three patients (25%) with AR grade 2 and 4 patients (22%) with AR grade 3-4 had zero level diastolic flow in the common carotid artery. Statistically significant changes of decreased end-diastolic velocity, increased peak systolic velocity/end-diastolic velocity, resistivity index, and pulsatility index were revealed, especially in AR grade 3-4 compared to controls. Significantly increased shrink ratio was seen only in AR grade 3-4. CONCLUSION: Increased shrink ratio or changes in hemodynamics or pulse waveform can be used in recognition of AR.  相似文献   

18.
胎儿肾血管彩色多普勒检测   总被引:1,自引:0,他引:1  
本文报道了应用彩色多普勒超声显像仪对46例胎儿肾动脉血流的测定结果。胎儿肾动脉血流在发育不同阶段呈规律的变化:Vs、Vd、Tamx、CTI随胎龄的增加呈递增趋势,Vs/Vd随胎龄增加呈递减趋势,Vs反映肾动脉血流量,Vd反映肾动脉血管阻力,PI、RI在各胎龄期无明显差异。结果表明:应用多普勒超声检测胎儿肾动脉血流来评价胎儿周围循环状态,预测胎儿的发育情况是可行的,并且是可靠的。  相似文献   

19.
Findings of two-dimensional time-of-flight magnetic resonance (MR) angiography projection angiograms were prospectively compared with those of color Doppler sonography by using angiography as a standard in 23 consecutive patients (42 carotid bifurcations) to evaluate their utility in determining the presence of carotid artery stenosis. MR angiography helped detect 50% or greater lumen diameter stenosis (sensitivity, 0.96; specificity, 0.64). Color Doppler sonography with 1.25 m/sec peak systolic velocity as a threshold had a sensitivity of 0.96 and a specificity of 0.71. Statistical analysis showed a correlation between percentage of lumen diameter narrowing and the length of the zone of signal intensity loss with MR angiography (r = .69; P less than .0001). A stronger relationship was obtained between angiographic narrowing and peak systolic velocity derived from color Doppler sonography (r = .80; P less than .0001). Two-dimensional time-of-flight MR angiography displayed as projection angiograms and combined with carotid artery and combined with carotid artery sonography is a useful approach for helping detect and potentially grade the severity of stenoses of the carotid artery.  相似文献   

20.
 目的 探讨颈内动脉迂曲的危险因素及对脑血流动力学的影响。方法 缺血性脑卒中患者行全脑血管造影术,筛选出颈内动脉迂曲而无狭窄或闭塞的患者,分析其临床资料,观察大脑中动脉显影时间,并用经颅彩色多普勒对大脑中动脉血流动力学进行评价,同时与颈内动脉无迂曲患者进行比较。结果 年龄和高血压是颈内动脉迂曲的危险因素。颈内动脉迂曲患者大脑中动脉显影时间为(2.08±0.34) s,明显长于无迂曲组的显影时间(1.84±0.24) s,大脑中动脉收缩期血流速度为(75.77±15.09) cm/s,平均血流速度为(49.60±10.37) cm/s,明显低于无迂曲患者的收缩期血流速度和平均血流速度[(107.52±24.17) cm/s;(65.38±16.22) cm/s]。结论 颈内动脉迂曲与年龄及高血压关系密切,并可导致血流动力学改变。血管迂曲所致血流动力学障碍可能是其导致卒中的原因之一。  相似文献   

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