Objective To evaluate the accuracy of thoracic pedicle screw placement using the "funnel technique" and investigate its consistency in experimental study and clinical application.Methods The clinical data of three human cadavers and 11 patients with the installation of at least one thoracic pedicle screw at T1 -T12 from August 2006 to July 2008 were retrospectively analyzed. One junior spine surgeon lack of experience were responsible for placing these screws with the "funnel technique".The accuracy of screw placement and the complications related to the use of thoracic pedicle screws were analyzed by assessing postoperative CT scans. Results The mean follow-up time was 23.1 months,which showed no vascular or visceral complications, or iatrogenic neurological injury. The rate of unintended cortex perforations was 14% (10/72) in cadavers and 15% (8/55) in patients, respectively.The critical perforation occurred in two screws (3%) in cadavers and one screw (2%) in patients. There was no statistical difference between the percentage of cortex perforations in cadavers and patients. Of all the 11 patients, screw violation occurred laterally in six ( 11% ), medially in one ( 2% ) and superiorly in one (2%). No violations occurred inferiorly or anteriorly. For all patients, only one screw needed revision. The perforations made by the junior spine surgeon occurred in six screws in the first cadaver, three in the second cadaver and one in the third cadaver. Conclusions The "funnel technique" is a simple,safe, accurate and cost-effective technique for pedicle screw placement. The result of the experimental study is consistent with that of the clinical application. "funnel technique" is helpful for junior spine surgeons to master the technique of thoracic pedicle screw placement.

ObjectiveTo evaluate in vivo antithrombosis property of optimized FW-Ⅱ axial blood pump and provides evidence for future clinical use.MethodsA left ventricle-pump-descending aorta bypass model was established in five healthy sheep (60-70 kg) and the circulation of these sheep was assisted by FW-Ⅱ axial blood pump for 2 weeks.In preoperative and postoperative day 1,2,3,7,10 and 14,blood was drawn from the jugular vein to examine platelet activation and leukocyte-platelet aggregation respectively quantified with Annexin V,CD41/61 and CD14-PE by flow cytometry assays.Immediately after termination of the experiment,FW-Ⅱ axial blood pumps were explanted and each part was inspected for thrombus formation.Macroscopic and histological examinations were checked on heart,brain,kidney and spleen,respectively for thrombosis.ResultsCompared with preoperative baseline,the number of platelet activation and leukocyte-platelet aggregation reached a peak at postoperative day 2,it retained a high level within 7 days,then gradually decreased,but was still higher than preoperative level at dayl4.According to rotating speed,the number of platelet activation and platelet-leukocyte aggregation were lowest at the speed of 8000 r/min Minus thrombus were found in the front and rear hub of the pump rotor,and there was no thrombus at other components (flow straighter,impeller and pump housing).There were no ischemia and infarction evidences in macroscopic and histological examination of the heart,brain,kidney and spleen.ConclusionFW-II axial blood pump can be used to assist left ventricular circulation for 2 weeks with a satisfactory antithrombosis property.The level of platelet activation and leukocyte-platelet aggregation can be reduced to a lowest level at an optimized pump rotating speed.

Objective To investigate the correlation between quantitative perfusion histogram parameters of DCE-MRI and tumor tissue microvessel density(MVD) in patients with lung cancer.Methods 30 patients with lung cancer confirmed by pathology who underwent preoperative DCE-MRI were enrolled in this retrospective study .Quantitative perfusion histogram pa-rameters( including median, mean, skewness, kurtosis, energy, entropy) were measured for each patient using Exchange mo-dle.Using the Immunohistochemical method to detect the expression of CD34 in tumor tissue, and counting the number of mi-crovessels under microscope.SPSS 19.0 was used to carry out statistical analysis.The correlation between MVD and quantita-tive perfusion histogram parameters of DCE-MRI measured by exchange model was evaluated by Pearson linear correlation anal-ysis.Results There was no significant difference in MVD and each quantitative perfusion histogram parameters between the three different pathological groups of lung cancer(P >0.05).Ktrans perfusion histogram parameters(mean, 25％, 50％, 50％, 75％, 90％, 95％), Kep perfusion histogram parameters(entropy, 10％, 25％, 50％, 75％, 90％), Fp perfusion histogram parameters( mean, 25％, 50％, 75％, 90％, 95％) and Vp perfusion histograms parameters ( entropy, 75％, 90％, 95％ ) were positively correlated with MVD(P<0.05).Ktrans perfusion histogram parameters(energy) and Vp perfu-sion histogram parameters(skewness, kurtosis, energy) were negatively correlated with MVD(P<0.05).There was no signifi-cant correlation between Ve perfusion histogram parameters and MVD(P>0.05).Conclusion There was a certain correla-tion between the perfusion histogram parameters of DCE-MRI and MVD,suggesting that the quantitative perfusion histogram of DCE-MRI in lung cancer can reflect the MVD value of cancer tissue .

The tip structure is one of the key factors to determine the performance of left ventricular assist device (LVAD) inflow cannulas. The tip structure influences the thrombosis, hemolysis in cannula and left ventricle and suction leading to obstruction in ventricle. We designed four kinds of inflow cannulas that had different tips and built the numerical models of the four historical used inflow cannulas inserted into the apex of left ventricle. We computed the hemodynamic characteristics of inflow cannulas insertion by Fluent software. We researched the backflow, turbulent flow and pressure distribution of the four inflow cannulas. The results showed that the trumpet tipped inflow cannula had smooth flow velocity distribution without backflow or low velocity flow. The trumpet tipped inflow cannula had the best blood compatibility characteristics. The trumpet structure could prevent obstruction. The caged tipped cannula had serious turbulent flow which could possibly cause thrombosis and the low pressure near left ventricle wall and easily lead to ventricle collapse. The trumpet tipped inflow cannula has the best blood compatibility and is difficult to be obstructed. The trumpet tipped inflow cannula is fit to long-term use LVAD.
Catheters ; Computer Simulation ; Equipment Design ; Heart Failure ; therapy ; Heart-Assist Devices ; adverse effects ; Hemolysis ; Humans ; Numerical Analysis, Computer-Assisted ; Thrombosis ; prevention & control ; Ventricular Dysfunction, Left ; prevention & control

Malignant tumors are one of the main causes of human death worldwide and pose a serious threat to human health. The current treatment methods are mainly the combination of chemotherapeutics， surgery， radiotherapy， or hormone therapy. The treatment process has limitations such as multidrug resistance， non-selective targeting of cancer cells， and drug toxicity. With the development and application of traditional Chinese medicine （TCM）， Chinese medicine has the characteristics of multi-angle and multi-mechanism coordination and slight toxic and side effects. It can effectively inhibit tumor proliferation， differentiation， and metastasis， and avoid drug resistance， serving as the focus of current tumor treatment research. Hedysari Radix， one of the genuine medicinal materials in Gansu province， is a tonic Chinese medicine with a wide range of pharmacological effects such as anti-inflammation， immune regulation， anti-oxidation， prevention and treatment of diabetic complications. In the majority of the ancient works on herbs of the past dynasties， Hedysari Radix was included under the item of Astragali Radix and used as Astragali Radix. Hedysari Radix is superior to Astragali Radix in enhancing immunity， scavenging free radicals， and resisting liver fibrosis. Studies have found that the effective components of Hedysari Radix have a prominent anti-tumor effect and a significant inhibitory effect on various malignant tumors such as liver cancer， bladder cancer， gastric cancer， breast cancer， and colorectal cancer. They can also combine with clinical anti-cancer drugs to reduce the toxic and side effects of chemotherapy drugs and improve the tolerance of patients during chemotherapy. On the basis of current research， this study summarized the mechanism of Hedysari Radix active components in inducing cell apoptosis， blocking cell cycle， inhibiting tumor cell proliferation， migration， and invasion， regulating micro mRNA （miRNA）， inducing cell autophagy， enhancing immune regulation， as well as reducing toxicity and enhancing efficiency and sensitization with clinical chemotherapeutics， and systematically explained the anti-tumor mechanism of Hedysari Radix active components， aiming to provide a basic reference for the further exploration of the anti-tumor mechanism of Hedysari Radix and the further development and utilization of its effective components.

An implantable axial blood pump was designed according to the circulation assist requirement of severe heart failure patients of China. The design point was chosen at 3 L/min flow rate with 100 mm Hg pressure rise when the blood pump can provide flow rates of 2-7 L/min. The blood pump with good hemolytic and anti-thrombogenic property at widely operating range was designed by developing a structure that including the spindly rotor impeller structure and the diffuser with splitter blades and cantilevered main blades. Numerical simulation and particle image velocimetry (PIV) experiment were conducted to analyze the hydraulic, flow fields and hemolytic performance of the blood pump. The results showed that the blood pump could provide flow rates of 2-7 L/min with pressure rise of 60.0-151.3 mm Hg when the blood pump rotating from 7 000 to 11 000 r/min. After adding the splitter blades, the separation flow at the suction surface of the diffuser has been reduced efficiently. The cantilever structure changed the blade gap from shroud to hub that reduced the tangential velocity from 6.2 m/s to 4.3-1.1 m/s in blade gap. Moreover, the maximum scalar shear stress of the blood pump was 897.3 Pa, and the averaged scalar shear stress was 37.7 Pa. The hemolysis index of the blood pump was 0.168% calculated with Heuser's hemolysis model. The PIV and simulated results showed the overall agreement of flow field distribution in diffuser region. The blood damage caused by higher shear stress would be reduced by adopting the spindle rotor impeller and diffuser with splitter blades and cantilevered main blades. The blood could flow smoothly through the axial blood pump with satisfactory hydraulics performance and without separation flow.
China ; Computer Simulation ; Equipment Design ; Heart Failure ; therapy ; Heart-Assist Devices ; Hemolysis ; Humans ; Models, Cardiovascular