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162 results on '"Wei, Xufeng"'

6. Control of position sensorless for permanent magnet toroidal motor

Author

Liu Xin and Wei Xufeng

Subjects
permanent magnet toroidal motor, mathematical model, position sensorless control, MRAS, Electronics, TK7800-8360
Abstract

Based on the analysis of the structure and driving mechanism of the permanent magnet toroidal motor, the inductance of the motor was analyzed and calculated, the mathematical model was established. Based on the advantages of position sensorless control, the position sensorless control model based on model reference adaptive system(MRAS) applied for permanent magnet toroidal motor was designed, the simulation of control system was established. The simulation results show that the motor speed and the position angular of the planet carrier rotor error based on MRAS are small, the control system based on MRAS can estimate the planet carrier rotor angular speed accurately, and the control method is effective.

Published
2019
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33. Effectiveness of a novel, completely biomaterial valved pulmonary arterial conduit: An in vivo study.

Author

Ren, Kai, Duan, Weixun, Lu, Linhe, Yu, Bo, Chen, Tao, Jin, Zhenxiao, Zhao, Yimin, Yi, Dinghua, Yu, Shiqiang, and Wei, Xufeng

Subjects
CONGENITAL heart disease, PULMONARY valve, BLOOD coagulation tests, BLOOD testing, IN vivo studies, EXTRACORPOREAL membrane oxygenation, ARTIFICIAL blood circulation
Abstract

As a pre-clinical assessment, the present study aimed to investigate the safety and effectiveness of a novel valved pulmonary arterial conduit constructed entirely from biomaterials by transplanting it in the outflow tract of the right ventricle in sheep. Under extracorporeal circulation, the valved pulmonary arterial conduit was used to replace the pulmonary artery of sheep with a beating heart. The performance was assessed at 30, 90 and 180 days post-surgery. Hemodynamic and structural changes were evaluated, and safety was assessed after 180 postoperative days. The hemodynamic effect and biosafety of the implant were further evaluated by observing the changes in various pressure indicators of the heart, echocardiographic results, anatomical and pathological examination results, liver and kidney functions, routine blood tests, a blood coagulation test, and other test results following implantation of the purely biotic valved conduit. The conduit was successfully implanted in 12 sheep and no mortality occurred postoperatively. During the 180-day follow-up, there was no obvious stenosis or regurgitation of the right ventricular outflow tract and pulmonary valve after valved conduit implantation. The findings of autopsy, pathology and laboratory examinations were unremarkable. The implantation of this biosynthetic vascular graft into animals meets the safety and effectiveness requirements for clinical application. This pulmonary arterial conduit has potential clinical application for children with complex congenital heart disease who require pulmonary artery reconstruction to achieve a radical cure. [ABSTRACT FROM AUTHOR]

Published
2020

35. Extracorporeal Respiratory Support with a Miniature Integrated Pediatric Pump-Lung device (PediPL) in an Acute Ovine Respiratory Failure Model

Author

Wei, Xufeng, Sanchez, Pablo G, Liu, Yang, Watkins, A Claire, Li, Tieluo, Griffith, Bartley P, and Wu, Zhongjun J

Subjects
Sheep, Acute Lung Injury, Hemodynamics, Carbon Dioxide, Heart-Lung Machine, Pulmonary Artery, Respiration, Artificial, Article, Hypercapnia, Oxygen, Disease Models, Animal, Extracorporeal Membrane Oxygenation, Animals, Humans, Heart Atria, Child, Respiratory Insufficiency
Abstract

Respiratory failure is one of the major causes of mortality and morbidity all over the world. Therapeutic options to treat respiratory failure remain limited. The objective of this study was to evaluate the gas transfer performance of a newly developed miniature portable integrated pediatric pump-lung device (PediPL) with small membrane surface for respiratory support in an acute ovine respiratory failure model. The respiratory failure was created in six adult sheep using intravenous anesthesia and reduced mechanical ventilation at 2 breaths/min. The PediPL device was surgically implanted and evaluated for respiratory support in a venovenous configuration between the right atrium and pulmonary artery. The hemodynamics and respiratory status of the animals during support with the device gas transfer performance of the PediPL were studied for 4 h. The animals exhibited respiratory failure 30 min after mechanical ventilation was reduced to 2 breaths/min, indicated by low oxygen partial pressure, low oxygen saturation, and elevated carbon dioxide in arterial blood. The failure was reversed by establishing respiratory support with the PediPL after 30 min. The rates of O

Published
2016

37. Effects of Cardiopulmonary Support with a Novel Pediatric Pump-Lung (PediPL) in a Thirty-Day Ovine Animal Model

Author

Liu, Yang, Sanchez, Pablo G, Wei, Xufeng, Watkins, Amelia C, Niu, Shuqiong, Wu, Zhongjun J, and Griffith, Bartley P

Subjects
Sheep, Time Factors, L-Lactate Dehydrogenase, Heparin, Anticoagulants, Biocompatible Materials, Thrombosis, Equipment Design, Heart-Lung Machine, Platelet Activation, Article, Oxygen, Hemoglobins, Models, Animal, Animals, Equipment Failure, Blood Coagulation, Biomarkers
Abstract

The scarcity of donor organs has led to the development of devices that provide optimal long-term respiratory or cardiopulmonary support to bridge recipients as they wait for lung and/or heart transplantation. This study was designed to evaluate the 30-day in vivo performance of the newly developed pediatric pump-lung (PediPL) for cardiopulmonary support using a juvenile sheep model. The PediPL device was placed surgically between the right atrium and descending aorta in eight sheep (25.4-31.2 kg) and evaluated for 30 days. Anticoagulation was maintained with continuous heparin infusion (activated clotting time 150-200 s). The flow rate was measured continually, and gas transfer was measured daily. Plasma free hemoglobin, platelet activation, hematologic data, and blood biochemistry were assessed twice a week. Sheep were euthanized after 30 days. The explanted devices were examined for gross thrombosis. Six sheep survived for 30-32 days. During the study, the oxygen transfer rate of the devices was 54.9 ± 13.2 mL/min at a mean flow rate of 1.14 ± 0.46 L/min with blood oxygen saturation of 95.4% ± 1.7%. Plasma free hemoglobin was 8.2 ± 3.7 mg/dL. Platelet activation was 5.35 ± 2.65%. The animals had normal organ chemistries except for surgery-related transient alterations in kidney and liver function. Although we found some scattered thrombi on the membrane surfaces of some explanted devices during the necropsy, the device function and performance did not degrade. The PediPL device was capable of providing cardiopulmonary support with long-term reliability and good biocompatibility over the 30-day duration and offers the potential option for bridging pediatric patients with end-stage heart or lung disease to heart and/or lung transplantation.

Published
2015

42. Expression and significance of TWIST basic helix-loop-helix protein over-expression in gastric cancer

Author

Bai Fei-Hu, Ge Fu-Lin, Han Shuang, Ding Jie, Guo Xue-Yan, Chen Yu, Sun Shi-ren, Wei Xufeng, Zhang Yan-Qi, and Fan Daiming

Subjects
Male, Pathology, medicine.medical_specialty, Blotting, Western, Biology, Adenocarcinoma, Pathology and Forensic Medicine, Metastasis, Stomach Neoplasms, Cell Line, Tumor, medicine, Humans, Neoplastic transformation, RNA, Messenger, Messenger RNA, Metaplasia, Reverse Transcriptase Polymerase Chain Reaction, digestive, oral, and skin physiology, Twist-Related Protein 1, Cancer, Nuclear Proteins, Middle Aged, medicine.disease, Immunohistochemistry, digestive system diseases, Epithelium, Reverse transcriptase, Up-Regulation, Blot, medicine.anatomical_structure, Cell Transformation, Neoplastic, Cancer research, Female, Precancerous Conditions
Abstract

TWIST protein has been implicated in neoplastic transformation and development of some cancers. In this study, we aimed to investigate the expression of TWIST in gastric cancer and its clinical significance.A total of 76 cases of archival gastric cancer tissues were immunohistochemically evaluated for TWIST expression, and its expression was correlated with clinicopathological parameters. Semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the mRNA of TWIST in four gastric cancer cell lines and a normal immortalised gastric epithelial cell line (GES-1). The expression of TWIST protein in these cell lines and 14 pairs of fresh gastric carcinoma and adjacent normal tissue samples was detected by Western blotting.TWIST expression increased in diffuse-type gastric carcinoma compared with intestinal-type gastric carcinoma (26/42, 61.9% versus 9/34, 26.5%, p0.05). TWIST expression was significantly increased in 35 (46.1%) of the 76 cancers and correlated with lymph node metastasis (node positive rate 60.4%; node negative rate 21.4%; p0.05). The expression of TWIST protein was higher in 9/14 (64.3%) fresh cancer tissues compared with adjacent normal tissues. The expression of mRNA and protein of TWIST in gastric cancer cell lines was up-regulated compared with that in GES-1.TWIST was highly expressed in gastric cancer. Its up-regulation was associated with the neoplastic transformation and subsequent development of gastric cancer. Therefore, TWIST may be a useful prognostic marker and target for gastric cancer therapy.

Published
2007

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