Magnetization transfer for the assessment of bowel fibrosis in patients with Crohn’s disease: initial experience

Object

To assess the feasibility of magnetization transfer (MT) imaging of the bowel wall in patients with Crohn’s disease (CD), and to evaluate its utility for the detection of intestinal fibrosis.

Materials and methods

In this prospective study, 31 patients (age 39.0 ± 13.2 years) with CD were examined in a 1.5T MR scanner. To establish a standard of reference, two independent readers classified the patients in different disease states using standard MR enterography, available clinical data and histological findings. In addition to the standard protocol, a 2D gradient-echo sequence (TR/TE 32 ms/2.17 ms; flip angle 25°) with/without 1,100 Hz off-resonance prepulse was applied. MT ratios (MTR) of the small bowel wall were computed off-line on a pixel-by-pixel basis.

Results

The MT sequences acquired images of sufficient quality and spatial resolution for the evaluation of the small bowel wall without detrimental motion artefacts. In normal bowel wall segments, an intermediate MTR of 25.4 ± 3.4 % was measured. The MTR was significantly increased in bowel wall segments with fibrotic scarring (35.3 ± 4.0 %, p < 0.0001). In segments with acute inflammation, the mean MTR was slightly smaller (22.9 ± 2.2 %).

Conclusion

MT imaging of the small bowel wall is feasible in humans with sufficient image quality and may help with the identification of fibrotic scarring in patients with CD.     

Evaluation of atrial septal defects with 4D flow MRI—multilevel and inter-reader reproducibility for quantification of shunt severity

Purpose

With the hypothesis that 4D flow can be used in evaluation of cardiac shunts, we seek to evaluate the multilevel and interreader reproducibility of measurements of the blood flow, shunt fraction and shunt volume in patients with atrial septum defect (ASD) in practice at multiple clinical sites.

Materials and methods

Four-dimensional flow MRI examinations were performed at four institutions across Europe and the US. Twenty-nine patients (mean age, 43 years; 11 male) were included in the study. Flow measurements were performed at three levels (valve, main artery and periphery) in both the pulmonary and systemic circulation by two independent readers and compared against stroke volumes from 4D flow anatomic data. Further, the shunt ratio (Q_p/Q_s) was calculated. Additionally, shunt volume was quantified at the atrial level by tracking the atrial septum.

Results

Measurements of the pulmonary blood flow at multiple levels correlate well whether measuring at the valve, main pulmonary artery or branch pulmonary arteries (r = 0.885–0.886). Measurements of the systemic blood flow show excellent correlation, whether measuring at the valve, ascending aorta or sum of flow from the superior vena cava (SVC) and descending aorta (r = 0.974–0.991). Intraclass agreement between the two observers for the flow measurements varies between 0.96 and 0.99. Compared with stroke volume, pulmonic flow is underestimated with 0.26 l/min at the main pulmonary artery level, and systemic flow is overestimated with 0.16 l/min at the ascending aorta level. Direct measurements of ASD flow are feasible in 20 of 29 (69%) patients.

Conclusion

Blood flow and shunt quantification measured at multiple levels and performed by different readers are reproducible and consistent with 4D flow MRI.

     

Provision of thermal engineering with structural materials—Basis of its safe operation and development

The role of thermal engineering (among other sources) in power supply is represented and its main advantages are described. It is shown that increasing the efficiency of thermal engineering as a result of an increase of the energy carrier’s parameters was provided by creating new materials with improved service properties. While developing the technology of ultra-supercritical parameters new construction steels with the temperature of application up to 640°C have been developed and utilized in Russia. Perspective development of thermal engineering provides attainment of ultra-supercritical parameters (720–740°C), which can be implemented by application of a new class of construction materials—nickel-based ultra heat-resistant alloys.     

Goal and Progress of Power Tariff Reform——An interview with Liu Zhenqiu, Vice Director of Department of Price, NDRC

Power tariff reform has made many important and many importan and substantial progresses in respect of marketization The benchmark tariff is a revolutionary progress made in China's power tariff reform     

Targets and Misunderstandings in Pollutants Reduction of Power Plants——An Interview with Wang Zhixuan, Vice-Secretary of CEC

● The demand for organics reduction in power industry needs to be analyzed. Generally speaking, the organics from power plants is neither a main source of water pollution nor an emphasis of pollution control. ● The normal operation of FGD facilities is the key to fulfill the mission of SO2 emission reduction. ● The control of SO2 emission should not be imposed uniformly on all power plants nationwide. ● It is difficult to promote the emission trading of SO2 institutionally. ● The active policy of levying for SO2 emission starting from zero emission and using levies for SO2 control is unreasonable. It should be reformed as levying only for over-limit emission, and not levying for emissions below limit or levying indicatively. ● Environmental regulations on SO2 control should make differences depending on environmental function of zones, time period of generating units installed and manner of emissions.     

Goal and Progress of Power Tariff Reform——An interview with Liu Zhenqiu,Vice Director ofDepartment of Price,NDRC

● Power tariffreform has made many important and substantialprogresses in respect ofmarketization● The benchmark tariff is a revolutionary progress made in China's power tariff reform● Coal-electricity price linkage is a transitional approach which needs further improvement● The principle of T&D pricing is "cost plus profit," but it can also be based on pro rata control● China's electricity market should choose the mode of bilateral contracting combined withcentralized market● The direction of the power tar...     

Detection of axonal degeneration in a mouse model of Huntington’s disease: comparison between diffusion tensor imaging and anomalous diffusion metrics

Magnetic Resonance Materials in Physics, Biology and Medicine - The goal of this work is to study the changes in white matter integrity in R6/2,&nbsp;a well-established animal model of...     

Power system decarbonisation with Global Energy Interconnection——a case study on the economic viability of international transmission network in Australasia

The electric energy system in Indonesia is undergoing with the challenges of fast-increasing electricity demand,carbon constraints,and rising costs.Using our model of the Australian and Indonesian electrical grids(either separately or interconnected)that incorporates operational flexibility in capacity expansion planning,we first show that meeting the projected demand for Java and Bali—the main Indonesian grid,with 100%locally integrated renewables by 2050 would be challenging.However,a submarine high-voltage DC(HVDC)link connecting Indonesia’s Java-Bali power grid to the Australian National Electricity Market(NEM)grid through the Northern Territory would help alleviate this situation,given Australia’s abundant renewable energy resources.Then,our model reveals that the Australian NEM could also profit from additional renewables if connected to the Northern Territory through a ground HVDC transmission line to gather intermittent wind and solar generation,which would be curtailed otherwise if unused by Indonesia through the submarine link.Despite the expensiveness of long HVDC links,the wholesale electricity cost of the integrated 100%renewable Australasia power system could be reduced by over 16%,from$AUD177/MWh with only local renewables to$AUD148/MWh with integrated HVDC transmission.The model retrieved the optimal international HVDC link with capacity of 43.8 GW,and the optimal regional HVDC transmission line with a capacity of 5.5 GW.To the best of our knowledge,this is the first detailed model on power system decarbonisation planning for both Australian NEM and Indonesian Java-Bali power grid considering HVDC interconnections.     

Novel economic modelling of a peer-to-peer electricity market with the inclusion of distributed energy storage—The possible case of a more robust and better electricity grid

Current electricity distribution systems allow prosumers to sell their surplus electricity back to the Distributed Network Operator (DNO). The export tariffs at which these sell-backs take place are considerably lower than the feed-in tariffs, offering little incentive to prosumers to sell their surplus energy. A peer-to-peer (P2P) electricity market where consumers and prosumers can interact by selling and buying energy between them at a premium rate that is lower than the standard feed-in tariffs but higher than the export tariffs is proposed. Such a system was modelled to process transactions every 20 s, and a simulation tool was created to obtain the total daily money flows between a consumer-prosumer pair. The inclusion of a Distributed Storage System (DSS) is also considered in the modelled system and simulation. The simulation results showed that the inclusion of a DSS is always beneficial for all parties in economic terms: consumers could save up to 6.4 % on the cost of their electricity while prosumers could save up to 49.1 %. A DSS could generate an income flow for the DNO of up to 6.9p/day per each consumer-prosumer pair.     

Fundamental Research on Enhancing Operation Reliadility for Lange-Scale Interconnected Power Crids——An interview with Zhou Xiaoxin,chief scientist of973 Program

At the end of last year,the editors from Power and Electrical Engineers interviewedZhou Xiaoxin on Fundamental Research on Enhancing Operation Reliability for Large-ScaleInterconnected Power Grids,a project of 973 Program.Mr.Zhou,the chief engineer ofChina Electric Power Research Institute (CEPRI) and an academician of Chinese A-cademy of Sciences,is the chief scientist in charge of this research project.     

Amid the Pointing and the Horror beyond the Clean Flame——On Quentin＇s Confession of Incest with His Sister Caddy in The Sound and the Fury

The connotation of＂incesf＇ in Quentin＇s narration goes beyond what Faulkner would admit. It reflects not only the complex relationship between Quentin and his sister Caddy, but also the angst the protagonist feels in pursuit of infinitude.     

Analysis of Space Harmonic Interactions in Squirrel Cage Induction Machines—Part I: Modeling and the Equivalent Circuit

ABSTRACT

By means of the transition from the symmetrical components to the α, β components regarding the rotor variables it is possible to obtain a linear model of the voltage equations representation. It is shown that, even in this linear formulation the harmonic interactions are not separated. The equivalent circuit which expresses the harmonic interactions and accounts for the stator additional harmonic currents is presented. In the light of this equivalent circuit, the suitable choice of the cage bars number can be performed. It is possible also to make a good base regarding the assessment of the differential leakage.     

The Thaw: The End of the Ice Age For American Utility Rate Cases—Are You Ready?

Rate cases are surging, but few energy utilities still boast the degree of in-house expertise that they did in the late 1980s. Today, with respect to two essential elements of the equation for regulated rates – costs and quantities – companies have to look outside for expertise and support. Planning and successfully prosecuting a rate case involves a host of detailed, interrelated technical and strategic analyses and policy decisions.