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Piezoelectric pump with flexible venous valves for active cell transmission

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0712-4

摘要： The development of organ-on-a-chip systems demands high requirements for adequate micro-pump performance, which needs excellent performance and effective transport of active cells. In this study, we designed a piezoelectric pump with a flexible venous valve inspired by that of humans. Performance test of the proposed pump with deionized water as the transmission medium shows a maximum output flow rate of 14.95 mL/min when the input voltage is 100 V, and the pump can transfer aqueous solutions of glycerol with a viscosity of 10.8 mPa·s. Cell survival rate can reach 97.22% with a yeast cell culture solution as the transmission medium. A computational model of the electric-solid-liquid multi-physical field coupling of the piezoelectric pump with a flexible venous valve is established, and simulation results are consistent with experimental results. The proposed pump can help to construct the circulating organ-on-a-chip system, and the simple structure and portable application can enrich the design of microfluidic systems. In addition, the multi-physical field coupling computational model established for the proposed piezoelectric pump can provide an in-depth study of the characteristics of the flow field, facilitating the optimal design of the micro-pump and providing a reference for the further study of active cell transport in organ-on-a-chip systems.

关键词： venous valve     flexible venous valve     cell transmission     organ-on-a-chip system     piezoelectric device    

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Classification and treatment of orbital venous malformations: an updated review

Tianyuan Li, Renbing Jia, Xianqun Fan

《医学前沿（英文）》 2019年 第13卷 第5期   页码 547-555 doi: 10.1007/s11684-018-0623-2

摘要： Orbital venous malformation (OVM) is a congenital vascular disease. As a common type of vascular malformation in the orbit, OVM may result in vision deterioration and cosmetic defect. Classification of orbital vascular malformations, especially OVMs, is carried out on the basis of different categories, such as angiogenesis, hemodynamics, and locations. Management of OVM is complicated and challenging. Treatment approaches include sclerotherapy, laser therapy, embolization, surgical resection, and radiotherapy. A satisfactory outcome can be achieved only by selecting the appropriate treatment according to lesion characteristics and following the sequential multi-method treatment strategy. This article summarizes the current classification and treatment advances in OVM.

关键词： orbit     venous malformation     treatment     sclerotherapy     laser     embolization    

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Antithrombin deficiency and decreased protein C activity in a young man with venous thromboembolism:

null

《医学前沿（英文）》 2018年 第12卷 第3期   页码 319-323 doi: 10.1007/s11684-017-0553-4

摘要：

Antithrombin and protein C are two crucial members in the anticoagulant system and play important roles in hemostasis. Mutations in and lead to deficiency or dysfunction of the two proteins, which could result in venous thromboembolism (VTE). Here, we report a Chinese 22-year-old young man who developed recurrent and serious VTE in cerebral veins, visceral veins, and deep veins of the lower extremity. Laboratory tests and direct sequencing of and were conducted for the patient and his family members. Coagulation tests revealed that the patient presented type I antithrombin deficiency combined with decreased protein C activity resulting from a small insertion mutation c.848_849insGATGT in and a short deletion variant c.572_574delAGA in . This combination of the two mutations was absent in 400 healthy subjects each from southern and northern China. Then, we summarized all the mutations of the and gene reported in the Chinese Han population. This study demonstrates that the combination of antithrombin deficiency and decreased protein C activity can result in severe VTE and that the coexistence of different genetic factors may increase the risk of VTE.

关键词： antithrombin deficiency     protein C activity     mutation     variant     venous thromboembolism     anticoagulants    

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Venous thromboembolism in children with acute lymphoblastic leukemia in China: a report from the Chinese

《医学前沿（英文）》 2023年 第17卷 第3期   页码 518-526 doi: 10.1007/s11684-022-0958-6

摘要： Venous thromboembolism (VTE) is a complication in children with acute lymphoblastic leukemia (ALL). The Chinese Children’s Cancer Group-ALL-2015 protocol was carried out in China, and epidemiology, clinical characteristics, and risk factors associated with VTE were analyzed. We collected data on VTE in a multi-institutional clinical study of 7640 patients with ALL diagnosed in 20 hospitals from January 2015 to December 2019. First, VTE occurred in 159 (2.08%) patients, including 90 (56.6%) during induction therapy and 108 (67.92%) in the upper extremities. T-ALL had a 1.74-fold increased risk of VTE (95% CI 1.08–2.8, P = 0.022). Septicemia, as an adverse event of ALL treatment, can significantly promote the occurrence of VTE (P < 0.001). Catheter-related thrombosis (CRT) accounted for 75.47% (n = 120); and, symptomatic VTE, 58.49% (n = 93), which was more common in patients aged 12–18 years (P = 0.023), non-CRT patients (P < 0.001), or patients with cerebral thrombosis (P < 0.001). Of the patients with VTE treated with anticoagulation therapy (n = 147), 4.08% (n = 6) had bleeding. The VTE recurrence rate was 5.03% (n = 8). Patients with VTE treated by non-ultrasound-guided venous cannulation (P = 0.02), with residual thrombus (P = 0.006), or with short anticoagulation period (P = 0.026) had high recurrence rates. Thus, preventing repeated venous puncture and appropriately prolonged anticoagulation time can reduce the risk of VTE recurrence.

关键词： acute lymphoblastic leukemia     child     venous thromboembolism     epidemiology     clinical characteristic     risk factor    

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Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 212-218 doi: 10.1007/s11465-010-0009-x

摘要： Increasing the driving frequency of a piezoelectric vibrator can resolve the bottleneck of low flow in a valve piezoelectric pump. However, a piezoelectric pump of a traditional valve body presents the hysteretic nature of the valve, and macroscopic performance is up-frequency to flow-sharply. This research is to settle the bottleneck mentioned above. First, through the sub-experiment on various parameters of the plate valve of a piezoelectric pump, the reasons why a valve body itself can influence “up-frequency to flow-sharply”, which causes the hysteretic nature of the valve, were discovered. Second, an “E”-shaped valve and piezoelectric pump with an “E”-shaped valve (PPEV) were invented. Finally, the efficiency of PPEV has been proved helpful to reduce hysteretic nature in experiments. Under the similar conditions, compared with traditional pumps, the driving frequency of novel PPEV can be more than 10 times high, and the flow rate also can be several times high.

关键词： piezoelectricity     valve     pump     experiment     “     E”     -shaped valve    

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Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

《医学前沿（英文）》 2008年 第2卷 第3期   页码 244-247 doi: 10.1007/s11684-008-0046-6

摘要： Shunts and devascularizations have totally different effects on the hemodynamics of the portal venous system. The actual results of pericardial devascularization (PCDV) alone and conventional splenorenal shunt combined with pericardial devascularization (combined procedure, CP) should be determined by more clinical observations. This study aimed to evaluate effects on hemodynamics in the portal venous system after CP and PCDV only. In 20 patients who received CP and 18 who received PCDV, hemodynamic parameters of the portal venous system were studied by magnetic resonance angiography 1 week before and 2 weeks after operation. Free portal pressure (FPP) was continuously detected by a transducer during the operations. Compared to the preoperative data, a decreased flow in the portal vein (PVF) [(563.12 ± 206.42) mL/min (1080.63 ± 352.85) mL/min, < 0.05], a decreased portal vein diameter (PVD) [(1.20 ± 0.11) cm (1.30 ± 0.16) cm, < 0.01], a decreased FPP [(21.50 ± 2.67) mmHg (29.88 ± 2.30) mmHg, < 0.01] and an increased flow in the superior mesenteric vein (SMVF) [(1105.45 ± 309.03) mL/min (569.13 ± 178.46) mL/min, < 0.05] were found in the CP group after operation; a decreased PVD [(1.27 ± 0.16) cm (1.40 ± 0.23) cm, < 0.05], a decreased PVF [(684.60 ± 165.73) mL/min (1175.64 ± 415.09) mL/min, < 0.05], a decreased FPP [(24.40 ± 3.78) mmHg (28.80 ± 3.56) mmHg, < 0.05] and an increased SMVF [(697.91 ± 121.83) mL/min (521.30 ± 115.82) mL/min, < 0.05] were observed in the PCDV group. After operation, PVF in the CP group [(563.12 ± 206.42) mL/min (684.60 ± 165.73) mL/min, > 0.05] had no significant decrease, while FPP [(21.50 ± 2.67) mmHg (24.40 ± 3.78) mmHg, < 0.01] had a significant decrease as compared with that in the PCDV group. PVF and FPP could be decreased by both surgical procedures, but the effect of decreasing FPP was much better in the combined procedure than in PCDV alone. Further, there was no significant difference in PVF between the two groups. It is suggested that the combined surgical procedure could integrate the advantages of shunting with those of devascularization, as well as maintaining the normal anatomic structure of hepatic portal system, thus it should be one of the best choices for patients with portal hypertension when surgical interventions are considered.
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Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0726-y

摘要： Balance valve is a core component of the 11000-meter manned submersible “struggle,” and its sealing performance is crucial and challenging when the maximum pressure difference is 118 MPa. The increasing sealing force improves the sealing performance and increases the system’s energy consumption at the same time. A hybrid analytical–numerical–experimental (ANE) model is proposed to obtain the minimum sealing force, ensuring no leakage at the valve port and reducing energy consumption as much as possible. The effects of roundness error, environmental pressure, and materials on the minimum sealing force are considered in the ANE model. The basic form of minimum sealing force equations is established, and the remaining unknown coefficients of the equations are obtained by the finite element method (FEM). The accuracy of the equation is evaluated by comparing the independent FEM data to the equation data. Results of the comparison show good agreement, and the difference between the independent FEM data and equation data is within 3% when the environmental pressure is 0–118 MPa. Finally, the minimum sealing force equation is applied in a balance valve to be experimented using a deep-sea simulation device. The balance valve designed through the minimum sealing force equation is leak-free in the experiment. Thus, the minimum sealing force equation is suitable for the ultrahigh pressure balance valve and has guiding significance for evaluating the sealing performance of ultrahigh pressure balance valves.

关键词： seawater balance valve     sealing performance     hybrid ANE model     FEM     minimum sealing force equation    

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Artificial bee colony optimization for economic dispatch with valve point effect

Yacine LABBI,Djilani Ben ATTOUS,Belkacem MAHDAD

《能源前沿（英文）》 2014年 第8卷 第4期   页码 449-458 doi: 10.1007/s11708-014-0316-8

摘要： In recent years, various heuristic optimization methods have been proposed to solve economic dispatch (ED) problem in power systems. This paper presents the well-known power system ED problem solution considering valve-point effect by a new optimization algorithm called artificial bee colony (ABC). The proposed approach has been applied to various test systems with incremental fuel cost function, taking into account the valve-point effects. The results show that the proposed approach is efficient and robust when compared with other optimization algorithms reported in literature.

关键词： artificial bee colony (ABC) algorithm     economic dispatch (ED)     valve-point effect     optimization    

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Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 420-434 doi: 10.1007/s11465-020-0622-2

摘要： Pilot two-stage proportional valves are widely used in high-power hydraulic systems. For the purpose of improving the dynamic performance, reliability, and digitization of the traditional proportional valve, a novel two-stage proportional valve with a pilot digital flow distribution is proposed from the viewpoint of the dual nozzle-flapper valve’s working principle. In particular, the dual nozzle-flapper is decoupled by two high-speed on/off valves (HSVs). First, the working principle and mathematical model of the proposed valve are determined. Then, the influences of the control parameters (duty cycle and switching frequency) and structural parameters (fixed orifice’s diameter and main valve’s spring) on the main valve’s motion are analyzed on the basis of theory, simulation, and experiment. In addition, in optimizing the value of the fixed orifice’s diameter, a new design criterion that considers the maximum pressure sensitivity, flow controllability, and flow linearization is proposed to improve the balance between the effective displacement and the displacement fluctuation of the main valve. The new scheme is verified by simulations and experiments. Experimental results of the closed-loop displacement tracking have demonstrated that the delay time of the main valve is always within 3.5 ms under different working conditions, and the tracking error can be significantly reduced using the higher switching frequency. The amplitude–frequency experiments indicate that a ‒3 dB-frequency of the proposed valve can reach 9.5 Hz in the case of±50% full scale and 15 Hz in the case of 0%–50% full scale. The values can be further improved by increasing the flow rate of the pilot HSV.

关键词： two-stage proportional valve     digital flow distribution     high-speed on/off valve     position tracking characteristic     dynamic performance    

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Right coronary occlusion following transcatheter aortic valve implantation: two case reports

null

《医学前沿（英文）》 2016年 第10卷 第3期   页码 351-355 doi: 10.1007/s11684-016-0465-8

摘要：

This paper discusses two male patients with severe aortic stenosis, whose right coronary arteries (RCA) were completely occluded during transcatheter aortic valve implantation (TAVI), leading to fatal hemodynamic disorder. Occlusions of RCA complicated by TAVI are rare. In addition, emergency cardiopulmonary bypass (CPB) played a critical role in rescuing our second patient. Both patients were admitted for “severe aortic stenosis,” and TAVIs were performed. The first patient’s blood pressure immediately dropped to 70/40 mmHg after the balloon expansion and did not increase much after the administration of aramine or fluid therapy. He did not receive emergency surgery and died after 1.5 h of resuscitation. The second patient’s blood pressure fluctuated greatly for several minutes after the valve implantation, ranging from 170/100 mmHg to 60/40 mmHg. Angiography revealed a total occlusion of RCA. Thoracic surgery with CPB was performed, and the patient survived.

关键词： aortic stenosis     transcatheter aortic valve implantation     right coronary occlusion     cardiac group    

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improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve

《医学前沿（英文）》 2021年 第15卷 第3期   页码 416-437 doi: 10.1007/s11684-021-0852-7

摘要： Over the last half century, surgical aortic valve replacement (SAVR) has evolved to offer a durable and efficient valve haemodynamically, with low procedural complications that allows favourable remodelling of left ventricular (LV) structure and function. The latter has become more challenging among elderly patients, particularly following trans-catheter aortic valve implantation (TAVI). Precise understanding of myocardial adaptation to pressure and volume overloading and its responses to valve surgery requires comprehensive assessments from aortic valve energy loss, valvular-vascular impedance to myocardial activation, force-velocity relationship, and myocardial strain. LV hypertrophy and myocardial fibrosis remains as the structural and morphological focus in this endeavour. Early intervention in asymptomatic aortic stenosis or regurgitation along with individualised management of hypertension and atrial fibrillation is likely to improve patient outcome. Physiological pacing via the His-Purkinje system for conduction abnormalities, further reduction in para-valvular aortic regurgitation along with therapy of angiotensin receptor blockade will improve patient outcome by facilitating hypertrophy regression, LV coordinate contraction, and global vascular function. TAVI leaflet thromboses require anticoagulation while impaired access to coronary ostia risks future TAVI-in-TAVI or coronary interventions. Until comparable long-term durability and the resolution of TAVI related complications become available, SAVR remains the first choice for lower risk younger patients.

关键词： surgical aortic valve replacement     trans-catheter aortic valve implantation     left ventricular hypertrophy and fibrosis     myocardial force-velocity relationship     His-Purkinje pacing     renin-angiotensin system inhibitors     coronary access impairment    

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Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 439-441 doi: 10.1007/s11465-007-0075-x

摘要： A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen any excessive control valve poppet bouncing.

关键词： control     computational     bouncing     CFD     excessive control    

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Solution to economic dispatch problem with valve-point loading effect by using catfish PSO algorithm

K. MURALI,T. JAYABARATHI

《能源前沿（英文）》 2014年 第8卷 第3期   页码 290-296 doi: 10.1007/s11708-014-0305-y

摘要： This paper proposes application of a catfish particle swarm optimization (PSO) algorithm to economic dispatch (ED) problems. The ED problems considered in this paper include valve-point loading effect, power balance constraints, and generator limits. The conventional PSO and catfish PSO algorithms are applied to three different test systems and the solutions obtained are compared with each other and with those reported in literature. The comparison of solutions shows that catfish PSO outperforms the conventional PSO and other methods in terms of solution quality though there is a slight increase in computational time.

关键词： economic dispatch (ED)     valve point loading     catfish particle swarm optimization (PSO)     optimization    

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A hybrid BFA-PSO algorithm for economic dispatch with valve-point effects

T. Jayabarathi, Prateek Bahl, Harsha Ohri, Afshin Yazdani, V. Ramesh

《能源前沿（英文）》 2012年 第6卷 第2期   页码 155-163 doi: 10.1007/s11708-012-0189-7

摘要： This paper presents a novel and efficient method for solving the economic dispatch (ED) problems with valve-point effects, by integrating the biased velocity of particle swarm optimization (PSO) to the chemotaxis, swarming and reproduction steps of bacterial foraging algorithm (BFA). To include valve point effects sinusoidal terms are added to the fuel cost function. This makes the ED problems highly non-linear. In order to solve such problems the best cell (or particle) biased velocity (vector) is added to the random velocity of the BFA to reduce randomness in movement (evolution) and to increase swarming. This results in the hybrid bacterial foraging algorithm (HBFA). To demonstrate the effectiveness of the proposed HBFA method, numerical studies have been performed for three different sample systems. Comparison of the results obtained by the HBFA with the BFA and other evolutionary algorithms clearly show that the proposed method outperforms other methods in terms of convergence rate and solution quality in solving the ED problems with valve-point effects.

关键词： bacterial foraging algorithm (BFA)     economic dispatch (ED)     particle swarm optimization (PSO)     valve-point effects    

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Design of damping valve for vehicle hydro pneumatic suspension

DONG Mingming, HUANG Hua, GU Lian

《机械工程前沿（英文）》 2008年 第3卷 第1期   页码 97-100 doi: 10.1007/s11465-008-0014-5

摘要： According to the design features of a hydro pneumatic spring, the necessity of a separate damping valve is proposed. Based on a 1/4 vehicle linear suspension model, the optimum damping coefficient is worked out and the parameters of the damping valve are determined with the equivalent linearization method. A practical structure of the damping valve is proposed having a small size, high flowrate when the valve opens, and the ability of enduring high back pressure. Based on bench tests, the damping valve has been found to properly work and be suitable. The design method and damping valve structure are useful guides for hydro pneumatic suspension, especially for the design of heavy-duty vehicles.

关键词： ability     pneumatic     necessity     flowrate     equivalent linearization    

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标题 作者 时间 类型 操作

Piezoelectric pump with flexible venous valves for active cell transmission

期刊论文

Classification and treatment of orbital venous malformations: an updated review

Tianyuan Li, Renbing Jia, Xianqun Fan

期刊论文

Antithrombin deficiency and decreased protein C activity in a young man with venous thromboembolism:

null

期刊论文

Venous thromboembolism in children with acute lymphoblastic leukemia in China: a report from the Chinese

期刊论文

Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

期刊论文

Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

期刊论文

Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

期刊论文

Artificial bee colony optimization for economic dispatch with valve point effect

Yacine LABBI,Djilani Ben ATTOUS,Belkacem MAHDAD

期刊论文

Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

期刊论文

Right coronary occlusion following transcatheter aortic valve implantation: two case reports

null

期刊论文

improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve

期刊论文

Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

期刊论文

Solution to economic dispatch problem with valve-point loading effect by using catfish PSO algorithm

K. MURALI,T. JAYABARATHI

期刊论文

A hybrid BFA-PSO algorithm for economic dispatch with valve-point effects

T. Jayabarathi, Prateek Bahl, Harsha Ohri, Afshin Yazdani, V. Ramesh

期刊论文

Design of damping valve for vehicle hydro pneumatic suspension

DONG Mingming, HUANG Hua, GU Lian

期刊论文