Tumour enhancement with newly developed Mn-metalloporphyrin (HOP-9P) in magnetic resonance imaging of mice

The purpose of the study is to evaluate the tumour enhancing characteristics and biodistribution of a newly developed metalloporphyrin derivative, HOP-9P (13, 17-bis (1-carboxypropionyl) carbamoylethyl-3, 8-bis (1-phenylpropyloxyethyl)-2,7,12,18-tetra- methyl-porphynato manganese (III)). Seven mice bearing SCC VII tumours were imaged using T1-weighted conventional spin echo magnetic resonance images before and 5 min, 2 h and 24 h after intravenous injection of 0.1 mmol/kg of HOP-9P. For the acquired images, signal intensities of the tumour, muscle and oil-phantom were measured. Then, tumor/oil and tumor/muscle signal intensity ratios were calculated. Nineteen mice were sacrificed before or after the administration of HOP-9P (at 5 min, 2 h and 24 h), and the biodistribution of manganese in the tumour, muscle, liver, blood and kidneys was measured using optical emission spectrometers and was expressed as micrograms of manganese per gram of tissue. The tumour/muscle signal intensity ratio at 24 h (3.18 ± 0.34) was significantly higher than precontrast ratio (1.77 ± 0.20) (P < 0.05). The biodistribution assessment of manganese demonstrated that HOP-9P gradually and consistently accumulated in the tumour to reach the highest concentration at 24 h (3.49 ± 1.22 μ gMn/g). It is concluded that HOP-9P is a potential tumour-specific MR contrast agent. © 2001 Cancer Research Campaign http://www.bjcancer.co

A novel immunoscintigraphy technique using metabolizable linker with angiotensin II treatment

Immunoscintigraphy is a tumour imaging technique that can have specificity, but high background radioactivity makes it difficult to obtain tumour imaging soon after the injection of radioconjugate. The aim of this study is to see whether clear tumour images can be obtained soon after injection of a radiolabelled reagent using a new linker with antibody fragments (Fab), in conditions of induced hypertension in mice. Fab fragments of a murine monoclonal antibody against human osteosarcoma were labelled with radioiodinated 3′-iodohippuryl N-ɛ-maleoyl-L-lysine (HML) and were injected intravenously to tumour-bearing mice. Angiotensin II was administered for 4 h before and for 1 h after the injection of radiolabelled Fab. Kidney uptake of 125I-labelled-HML-Fab was much lower than that of 125I-labelled-Fab radioiodinated by the chloramine-T method, and the radioactivity of tumour was increased approximately two-fold by angiotensin II treatment at 3 h after injection, indicating high tumour-to-normal tissue ratios. A clear tumour image was obtained with 131I-labelled-HML-Fab at 3 h post-injection. The use of HML as a radiolabelling reagent, combined with angiotensin II treatment, efficiently improved tumour targeting and enabled the imaging of tumours. These results suggest the feasibility of PET scan using antibody fragment labelled with 18F-fluorine substitute for radioiodine. © 1999 Cancer Research Campaig

Transient stability analysis of wind generator system with the consideration of multi-mass shaft model

In order to investigate the impacts of the integration of wind farms into utilities networks, it is necessary to analyze the transient characteristic of wind power generation system (WPGS). In most of the cases, it is seen that the simple one-mass lumped model is considered for transient stability analysis of wind generator. But for the sake of exact analysis of transient stability of WPGS, it is needed to consider multi-mass shaft system model. In this study a detailed analysis has been done with the consideration of two-mass shaft system model of wind generator system when a severe network disturbance occurs in power system. Moreover, an online logical pitch controller has been proposed, which can enhance the transient performance of WPGS as well as maintain output power of wind generator at rated level when wind speed is above the rated speed. © 2005 IEEE

Blade-Shaft Torsional Oscillation Minimization of Wind Turbine Generator System by Using STATCOM/ESS

In this paper, blade and shaft torsional oscillations of wind turbine generator system (WTGS) are analyzed when a network disturbance occurs in the power system. Many studies have been reported so far about the shaft torsional oscillations of synchronous generators. Though a large number of wind generators are going to be connected with the existing network, the blade-shaft torsional oscillations of WTGS have not been reported so far sufficiently. In this paper, damping control of blade-shaft torsional oscillations of WTGS by using a voltage source converter (VSC) based STATCOM/BESS (battery energy storage system) topology is proposed. The six-mass drive train model of WTGS is used in the simulation analyses for the sake of precise analysis. Both symmetrical and unsymmetrical faults are considered as a network disturbance in the analyses. Simulation results clearly show that the proposed STATCOM/BESS can significantly decrease the blade and shaft torsional oscillations of WTGS. The simulations have been done by PSCAD/EMTDC. ©2007 IEEE

Transient stability analysis of grid connected wind turbine generator system considering multi-mass shaft modeling

In order to investigate the impacts of the integration of wind farms into utilities networks, it is necessary to analyze the transient characteristic of wind turbine generator system (WTGS). In most of the cases, the simple one mass lumped model is considered for stability analysis of wind generator. It is not analyzed yet which order shaft model is sufficient for transient stability analysis of WTGS. In this study, a detailed transient analysis has been done with the consideration of two mass and three mass shaft models of WTGS. Finally, it is concluded that two mass shaft model is sufficient enough for transient stability analysis of grid connected WTGS. Copyright © Taylor and Francis Group, LLC

Blade-shaft torsional oscillation minimization of wind turbine generator system by using STATCOM/ESS

In this paper, blade and shaft torsional oscillations of wind turbine generator system (WTGS) are analyzed when a network disturbance occurs in the power system. Many studies have been reported so far about the shaft torsional oscillations of synchronous generators. Though a large number of wind generators are going to be connected with the existing network, the blade-shaft torsional oscillations of WTGS have not been reported so far sufficiently. In this paper, damping control of blade-shaft torsional oscillations of WTGS by using a voltage source converter (VSC) based STATCOM/BESS (battery energy storage system) topology is proposed. The six-mass drive train model of WTGS is used in the simulation analyses for the sake of precise analysis. Both symmetrical and unsymmetrical faults are considered as a network disturbance in the analyses. Simulation results clearly show that the proposed STATCOM/BESS can significantly decrease the blade and shaft torsional oscillations of WTGS. The simulations have been done by PSCAD/EMTDC. ©2007 IEEE

Fault Analysis of Wind Turbine Generator System Considering Six-Mass Drive Train Model

This paper analyzes different types of symmetrical and unsymmetrical fault of grid connected wind turbine generator system (WTGS), where the six-mass drive train model is considered. The unsuccessful re-closing due to permanent fault is also considered. Moreover, the blade-shaft stresses of the six-mass drive train model of WTGS are also analysed for both successful and unsuccessful re-closing