小剂量测试技术和对比剂团注跟踪自动触发技术在肺动脉CTA的对比研究

目的对比研究小剂量测试技术和对比剂团注跟踪自动触发技术在肺动脉CTA诊断的意义。方法随机选取本院行肺动脉CTA检查的患者70例,将患者分成两组(每组35例),组1用小剂量测试技术扫描方式,组2用对比剂团注跟踪技术自动触发扫描,所有数据均在后处理工作站行多平面重组技术(multi planar reformatting,MPR)、最大密度投影(maximum intensity projection,MIP)和容积重现(volume rendering,VR)后处理,由两名高年资(主治职称以上)医生采用双盲法行主观评价,然后在工作站上测量肺动脉干、肺静脉和升主动脉CT值并应用统计学方法进行比较。结果两种扫描方式所获图像质量在主观评估方面无统计学意义(P>0.05)。两组图像的肺动脉干、肺静脉和升主动脉CT值差异有统计学意义(P<0.05),且小剂量测试扫描方法所用造影剂剂量更少。结论两种扫描方案(小剂量测试技术和对比剂团注跟踪自动触发技术)检查肺动脉所得图像中,主观影像质量评估无统计学差异,而客观影像质量评估(肺动脉干、肺静脉和升动脉CT值)有统计学意义(P<0.05),且小剂量测试扫描方式所用造影剂的剂量较少,故应用小剂量测试技术进行肺动脉CTA的检查具有重要的临床价值。

冠状动脉CTA评估心肌桥形态特征、发生位置与冠状动脉粥样硬化的关系

目的探讨冠状动脉CTA评估心肌桥形态特征、发生位置与冠状动脉粥样硬化的关系。方法方便抽取2013年4月—2015年11月该院收治的50例行冠状动脉CTA检查患者的图像资料,结合其心电图及心脏超声表现,并评估心肌桥与冠状动脉粥样硬化的关系。结果肌桥的发生率为40.00%,以前降支最为多见,占45.00%。前降支存在心肌桥的患者,血管冠状动脉粥样硬化的发生率明显高于无心肌桥的患者,差异有统计学意义(P<0.05);心肌桥近端冠状动脉粥样硬化的发生率明显高于壁冠状动脉及其远端冠状动脉粥样硬化的发生率,差异有统计学意义(P<0.05)。结论心肌桥近端动脉极易导致冠状动脉粥样硬化,可作为评估冠状动脉粥样硬化性心脏病的危险因素之一。

0D-1D coupling model and 3D fluid-structure interaction model based on coronary CT angiography for displaying hemodynamic characteristics of coronary artery stenosis

Objective To observe value of 0D-1D coupling model and 3D fluid-structure interaction(FSI)model based on coronary CT angiography(CCTA)for displaying hemodynamic characteristics of coronary artery stenosis.Methods Based on CCTA data of the stenosed left anterior descending branch(LAD)in a patient with coronary heart disease,an 0D-1D coupling model and 3D FSI model were built,respectively.Then hemodynamic characteristic indexes,including the pressure,flow velocity and wall shear stress(WSS)were obtained in every 0.01 s during 1 s at 5 sampling points(i.e.sampling point 1—5)using these 2 models,respectively,and the consistencies of the results between models were evaluated with Spearman correlation coefficient r s.Results The time consuming for construction of 0D-1D coupling model and 3D FSI model was 0.033 min and 704 min,respectively.Both models showed basically distribution of the pressure,flow velocity and WSS of the stenosed LAD.For more details,the pressure at the stenosed segment of LAD and the proximal segment of stenosis were both higher,which gradually decreased at the distal segment of stenosis,and the flow velocity at the proximal segment of stenosis was in a relatively slow and uniform condition,with significantly increased flow velocity and WSS at the stenosed segment.Compared with 3D FSI model,0D-1D vascular coupling model was relatively unrefined and lack of distal flow lines when displaying blood flow velocity.For sampling point 2 at the stenosed segment of LAD,no significant consistency for pressure between 2 models was found(P=0.118),but strong consistency for the flow velocity and WSS(r s=0.730,0.807,both P<0.05).The consistencies of pressure,flow velocity and WSS between 2 models at the proximal and distal segment of stenosis,i.e.1,3—5 sampling points were week to moderate(r s=0.237—0.669,all P<0.05).Conclusion 0D-1D coupling model exhibited outstanding computational efficiency and might provide relatively reasonable results,while 3D FSI model showed higher accuracy for details and streamline when simulating LAD stenosis.

Ultrafast pulse wave velocity technique for evaluating changes of carotid artery elasticity in Hashimoto thyroiditis patients with euthyroidism

Objective To explore the value of ultrafast pulse wave velocity(UFPWV)technique for evaluating changes of carotid artery elasticity in Hashimoto thyroiditis(HT)patients with euthyroidism.Methods Conventional ultrasound and UFPWV for carotid artery were prospectively performed in 91 HT patients with euthyroidism(HT group)and 81 healthy subjects(control group).Clinical data and ultrasonic parameters were compared between groups.Spearman correlation analysis was performed to observe the correlations of carotid pulse wave velocity in end of systole(PWV-ES)with clinical indexes and other ultrasonic parameters in HT group.Multiple stepwise linear regression analysis was used to screen the independent impact factors of increased carotid PWV-ES in HT group.Results Significant differences of thyroid peroxidase antibody(TPOAb),thyroglobulin antibody(TgAb),total cholesterol(TC),low density lipoprotein and neutrophil-lymphocyte ratio(NLR)were found between groups(all P<0.05).The carotid PWV-ES in HT group was significantly higher than that in control group(P<0.05),while no significant difference of carotid artery intima-media thickness(CIMT)nor carotid pulse wave velocity in beginning of systole(PWV-BS)was found between groups(both P>0.05).Carotid PWV-ES in HT group was positively correlated with patients'age,body mass index,TPOAb,TC,triglyceride,NLR and CIMT(r=0.217—0.707,all P<0.05).Patients'age,TPOAb and NLR were all independent impact factors of increased carotid PWV-ES in HT patients with euthyroidism(all P<0.05).Conclusion UFPWV technique could be used to evaluate changes of carotid artery elasticity in HT patients with euthyroidism,among which PWV-ES was relatively sensitive.

ROBUST ADAPTIVE CONTROL SCHEME FOR IMPROVING LOW-SPEED PROFILE TRACKING PERFORMANCE OF HYBRID STEPPING MOTOR SERVO DRIVE

A robust adaptive control approach is presented to improve the performance of the control scheme proposed in the authors＇ previous work, aiming at producing a low ripple hybrid stepping motor servo drive for precision profile tracking at a low speed. In order to construct a completely integrated control design philosophy to reduce torque ripple and at the same time to enhance tracking performance, the properties of nonlinear uncertainties in the system dynamics are uncovered, and then incorporated into the design of the controller. The system uncertainties concerned with ripple dynamics and other external disturbances are composed of two categories. The first category of uncertainties with linear parameterization arising from the detention effect is dealt with by the wellknown adaptive control method. A robust adaptive method is used to deal with the second category of uncertainties resulting from the non-sinusoidal flux distribution. The μ-modification scheme is used to cease parameter adaptation by the robust adaptive control law, thus ensuring that the trajectory tracking error asymptotically converges to a pre-specified boundary. Experiments are performed with a typical hybrid stepping motor to test its profile tracking accuracy. Results confirm the proposed control scheme.

Primary Mechanisms for Novel Compound Pivanampeta Against Atherosclerosis in Rat and Rabbit Model of Atherosclerosis

Aim To investigate the anti-atherosclerotic mechanisms of the novel compoundpivanampeta in the early and later stages of atherosclerosis evolution. Methods Rats or rabbits wererandomly assigned to the control, the model and the pivanampeta-treated groups. The rats or rabbitsin the model group and the pivanampeta-treated group were fed with hypercholesterol diet. Thecarotids of rabbits were cut into pieces and stained with HE. The rat or rabbit serum levels of TC,LDL-CHO, HDL-CHO, IL-8, ET-1, PGI_2, TXA_2, and NO were assayed. The expressions of MCP-1 and IL-8mRNA on rabbit carotid were determined by semi-quantitative RT-PCR. Results Pivanampeta exerted aninhibitory effect on TXA_2 formation without PGI_2 production in the early and later stages ofatherosclerosis. The significantly increased release of NO and the decreased release of IL-8 in theanimals in pivanampeta-treated group were both detected in the rat atherosclerosis model. In therabbit atherosclerosis model the expressions of IL-8 and MCP-1 mRNA in pivanampeta-treated groupwere decreased significantly. However, the treatment with pivanampeta had no effect on the levels ofplasma cholesterol, MDA and SOD. Conclusion The increase of serum NO contents and the decrease ofplasma TXA_2 level, as well as its inhibition of expression of IL-8 and MCP-1 are probably involvedin the mechanisms underlying the anti-atherosclerotic effects of pivanampeta.

Pathological Study of Excised Specimens from Resectable Large Hepatocellular Carcinoma after Transcatheter Arterial Chemoembolization

Objective: To investigate pathological changes in surgically excised specimens from resectable large hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE ) and their signi?cance. Methods: From January 2002 to January 2003, 83 patients with resectable large HCC were randomized into two groups: group A, 36 patients who underwent preoperative TACE, and group B, 47 patients who underwent one-stage operation without TACE. Hepatectomy was performed in 31 patients of group A (two-stage operation group) and 47 patients of group B (one-stage operation group). The remaining 5 patients in group A were not operable. The diagnosis of HCC was pathologically con?rmed in all 78 patients after hepatectomy. Pathological changes of the excised specimens between the two groups were compared, including main tumors, capsular containment, daughter nodules, tumor thrombi and liver cirrhosis. Results: There were no signi?cant di?erences in the incidence of daughter nodules , portal vein tumor thrombi (PVTT) and extrahepatic metastasis between the two groups, but the area of main tumor necrosis was more extensive and the rate of encapsulation was higher in two-stage operation group than those in one-stage operation group. No signi?cant shrinkage in the average tumor size was seen in two- stage operation group, where daughter nodules and PVTT necrosis were less, and liver cirrhosis was more serious. Conclusion: Preoperative TACE for resectable large HCC should be used on the basis of strict selection because it does not provide complete tumor necrosis and may result in delayed surgery in some cases.

The Preliminary Study of Certain Pharmacological Effects of Xi Xin Oil

细辛油能松弛兔离体主动脉条,使去甲肾上腺素所致主动脉收缩的量效曲线右移并效能降低;使离体兔耳灌流量减少;能延长小鼠常压耐缺氧时间;用其1/2 LD_(50)之剂量腹腔注射给药3天,可致小鼠骨髓微核形成增加。

Studies on Mitomycin C Dextran-microspheres

In this paper,the preparation and properties of mitomycin C dextran-microspheres(MMC-DMS)were reported.The characteristics of pharmacokinetics and embolization effects of MMC-DMS in vivo were studied in dogs.The average diameter of the microspheres was 75±19μm and the content was 5% of MMC.In in vitro experiment, the release rate of drug demonstrated that the microspheres had sustained-release properties. The microspheres and conventional MMC were infused into the hepatic artery of dogs through a catheter for embolization,respectively.The plasma concentration of MMC was de- termined by HPLC.Results showed that the peak concentration of conventional MMC was 2.6 times as much as MMC-DMS.Angiograms revealed that peripheral blood vessels de- creased obviously in liver.The histopathologic examination showed that the microspheres lodged in the hepatic artery and displayed nodular necrosis in the embolized segment.The MMC-DMS were used in clinical trial in 100 patients with hepatic cancer.The tumor reduc- tion and improvement of symptoms in patients were observed after hepatic arterial embolization.The survival duration was prolonged.Results showed that the MMC-DMS is a promising embolic agent for treatment of hepatic cancer.It could aid in the use of intensive chemotherapy with minimum systemic side effect.

Mechanism of anti-arterial thrombosis of Dahuangzhecong Fang screened by Ti-Al intermetallic compound porous material

The mechanism of antithrombotic of Dahuangzhechong Fang separated and purified by Ti-Al intermetallic compound porous material (TAICPM) was researched. Dahuangzhechong Fang, which was isolated and screened by TAICPM, was used to oral rats. At the end of study, their blood and thrombus were collected. The results show that TAICPM with the pore size of 1-5 μm can screen Dahuangzhechong Fang well. Dahuangzhechong Fang can increase 6-keto-PGF1α, lower content of TXD2 and platelet. Dahuangzhechong Fang has good effect to resist arterial thrombosis.

DSA Diagnosis of Carotid Body Tumor

Objective: To make a further understanding of the DSA features of the carotid body tumor (CBT) and to explore the clinical value of DSA diagnosis and interventional treatment for CBT. Methods: Twelve cases of CBT with DSA data were analyzed retrospectively. The DSA appearances in all of the patients were observed dynamically in a double blind manner by two experienced radiologists together and a consensus interpretation formed. Results: DSA could establish definitive diagnosis in all cases. The DSA features of the CBT were: the increase of bifurcation angles of internal and external carotid arteries in all cases; the CBT supplied by external carotid arteries in most cases and the significant increase of tumor vessels in bifurcation; invasion of internal or external carotid arteries in 6 cases. The tumor staining disappeared mostly after the supplying arteris were embolized in 2 cases, and the bleeding during the operation reduced significantly. Conclusion: The DSA is useful in the diagnosis of the CBT and for therapeutic planning. The pre-operation embolization of the CBT contributes to reduce the bleeding during operation.

Preoperative Localization of Insulinoma by Intra-arterial Spiral CT

Objective To evaluate the value of intra-arterial dynamic spiral CT on preoperative localization of insulinoma. Methods Two patients with insulinoma proved by operative pathology were preoperatively localized by intra-arterial dynamic spiral CT. Results In intra-arterial spiral CT, two small insulinomas (1.5–2.0 cm in diameter) demonstrated as a significantly high dense nodule 20 s later after initiation of injection of contrast medium. The course of high density lasted nearly 4 min. Conclusion Intra-arterial dynamic spiral CT could clearly detect small insulinoma, and might be one of most effective preoperative localization methods for small insulinoma. Key words insulinoma - anteriography - CT

Preparation and characterization of 9-nitrocamptothecin self-emulsifying microemulsion injection

Aim To prepare a self-emulsifying microemulsion of 9-nitrocamptothecin （9-NC ME） for intravenous injection and investi- gation of its pharmacokinetic profiles in normal SD rats. Methods 9-NC ME was optimized in terms of droplet size and lack of drug precipitation following aqueous dilution using a pseudo-ternary phase diagram. Physicochemical properties of 9-NC ME were evaluated. 9-NC ME was intravenously administered via tail vein in healthy rats. Results A stable microemulsion was formulated consisted of soybean oil as oil phase, EPC/Tween-80 as emulsifier, and anhydrous ethanol as co-emulsifier. The droplets of the microemulsion were spherical shape with mean diameter of 38.3 ± 4.0 nm after 1：20 dilution with 5% glucose injection. The pharmacokinetic parameters of 9-NC ME after intravenous administration in rats were t1/2 of 0.97 ± 0.14 h, A UC0-8 of 372.77 ±49.62 ng·h·mL^-1 and MRT of 1.40 ± 0.21 h which were 1.4-fold, 1.65-fold, and 1.4-fold more than those of 9-NC solution （P〈0.01）. Conclusion The results suggested that 9-NC ME was a promising drug delivery system and it was expected to provide a novel 9-NC injection for cancer patients.

Three-dimensional Imaging of Multi-slice Spiral CT in Bronchial Artery Correlative Study on Blood Supply of Central Lung Cancer and Its Clinical Significance

Objective: To evaluate three-dimensional bronchial artery imaging charactersin central lung cancer and applied values with multi-slice spiral CT (MSCT) to provide theoreticalevidence on blood supply and intervention therapy. Methods: Eighteen patients with central lungcancer underwent MSCT with real time helical thin-slice CT scanning. Three-dimensional bronchialartery reconstruction was done at the console work-station. The space anatomical characters ofbronchial artery were observed through different rotations. Results: For 6 cases, thethree-dimensional images of bronchial artery (33.33%) could exactly show the origins, the routes(lung inner segment and mediatism segment) and the diameters of bronchial arteries. Vision rate ofbronchial arteries was the highest in pulmonary artery stricture and truncation groups, and thevessels' diameter became larger apparently. These characters demonstrated blood supply of this kindof central lung cancer come from bronchial artery. Volume rendering images were the best ones amongthree-dimensional images. Conclusion: Three-dimensional imaging with MSCT in bronchial artery canreveal the anatomical characters of bronchial artery and provide theoretical evidence on bloodsupply and intervention therapy of central lung cancer.

EFFECT OF WALL FUNC TION IN NUMERICAL STUDY ON TURBULENT IMPINGING JET

A low Reynolds number k-ε model is used in the numeri cal study on a circular semi-confined turbulent impinging jet . The result is c ompared with that of the standard k-ε model and a refined k-ε mode l, which re-consi-dered the fluctuating pressure diffusion term in the dissipa tion rate equation (ε-equation) through modeling. It shows that the low Re ynolds number k-ε model and the standard k-ε model yield very poor performance, while the predicting ability of the refined k-ε model is mu ch improved , especially for the turbulent kinetic energy k. So it can be co ncluded that the poor performance of the standard k-ε model is owing to t he incorrect considering the effect of the fluctuating pressure diffusion term r ather than the use of the wall function near the wall just as presumed in the re ference.

Effect of electropulsing on dislocation mobility of titanium sheet

To investigate the effect of the electropulsing on dislocation mobility,specimens cut from the cold-rolled titanium sheet were treated by high density electropulsing with the maximum current density of 7.22,7.64,7.96 kA/mm 2 ,pulse period 110μs.The internal friction and elastic modulus were measured by a dynamic mechanical analyzer（DMA）.When strain amplitude lowers a certain critical one,the damping of the electropulsed titanium sheet is lower than that of the cold-rolled one.When the strain amplitude exceeds the critical one,the damping of the electropulsed titanium sheet is extraordinarily higher than that of the cold-rolled or conventional annealed one.Furthermore,it is found that the damping peak of the electropulsed titanium sheet shifts to lower temperature compared with the conventional annealed one.It is demonstrated that the electropulsing treatment can decrease dislocation tangles and enhance dislocation mobility.

Surgical Significance of the Aortic Root and its Neighbouring Structure Relationships

Objective: To measure the calibration of different levels in aortic root andevaluate the relationships between the aortic sinuses and its neighbouring structure. Methods:Thirty heart specimens from cadaver of normal adult were studied. The dimensions of four levels inaortic root were measured and the relationships between the aortic sinues and its neighbouringstructure were observed. Results: The dimensions of four levels in aortic root obtained as follows;Sinus > STJ1 > STJ0 > Base (P < 0.05) . The dimensions of the aortic valve leaflets were measured.The right coronary leaflet was larger than those of the left coronary and noncor-onary leaflets .But there was no statistical signiftcane (P > 0.05) . The relationships between the middle axis ofthe anterior valve of the bicuspid valve and the aortic sinuses were examined. The middle axis ofthe anterior valve in 26 specimens (86.6%) located between the left coronary sinus and thenoncoronary sinus . The relationship between the aortic prominence of the right atrium and theaortic sinuses was examined. The aortic prominence was formed from noncoronary sinus in 22 specimens(73.3%) . The relationship between the middle point of the right and left pulmonary valves and theaortic sinuses was examined. The middle point of the right and left pulmonary valves in 24 specimens(80%) was faced to the point between the right and left aortic sinuses . Conclusion: The dimensionof the four levels in aortic root is as follows, sinus > STJ1 > STJ0 > Base (P < 0.05) . There wasno statistical significance in the size of the three aortic valve leaflets (P > 0.05).

Studies on Adriamycin Magnetic Gelatin Microspheres

The preparation and properties of adriamycin magnetic gelatin microspheres(Adr- MG-ms)were reported.The synthesis of magnetic iron oxide ultrafine particle and embolization effects of magnetic gelatin microspheres(MG-ms)in dog were studied.Adr- MG-ms consist of 2%(w/w)of adriamycin(Adr)as the core,and 68% of gelatin and 30% of magnetite as the shell with a mean particle size of 22 μm. In vitro experiment,the release rate of drug demonstrated that the microspheres have sustained-release properties.The average diameter of magnetic iron oxide was approximately l0 nm. Transcatheter embolization with MG-ms and ￣(99m)Tc-labelled MG-ms was performed under external magenet control in dog liver,respectively.Gamma photography and angiogram revealed that MG-ms level was almost equal both in left and right hepatic arteries without magnet,while with magnet(1200 Gs),MG-ms level in left hepatic artery(target site)was about 2.25 fold higher than in right hepatic artery,and few MG-ms in thyroid gland,brain and heart was observed.Results showed that the MG-ms is a promising embolic agent for treatment of hepatic cancer under external magnet control.