Towards an integrated neonatal brain and cardiac examination capability at 7 T: electromagnetic field simulations and early phantom experiments using an 8-channel dipole array

Objective

Neonatal brain and cardiac imaging would benefit from the increased signal-to-noise ratio levels at 7 T compared to lower field. Optimal performance might be achieved using purpose designed RF coil arrays. In this study, we introduce an 8-channel dipole array and investigate, using simulations, its RF performances for neonatal applications at 7 T.

Methods

The 8-channel dipole array was designed and evaluated for neonatal brain/cardiac configurations in terms of SAR efficiency (ratio between transmit-field and maximum specific-absorption-rate level) using adjusted dielectric properties for neonate. A birdcage coil operating in circularly polarized mode was simulated for comparison. Validation of the simulation model was performed on phantom for the coil array.

Results

The 8-channel dipole array demonstrated up to 46% higher SAR efficiency levels compared to the birdcage coil in neonatal configurations, as the specific-absorption-rate levels were alleviated. An averaged normalized root-mean-square-error of 6.7% was found between measured and simulated transmit field maps on phantom.

Conclusion

The 8-channel dipole array design integrated for neonatal brain and cardiac MR was successfully demonstrated, in simulation with coverage of the baby and increased SAR efficiency levels compared to the birdcage. We conclude that the 8Tx-dipole array promises safe operating procedures for MR imaging of neonatal brain and heart at 7 T.

     

防黑客设计技术

随着嵌入设备渗透进社会,并承担起更加重要的角色,安全失效会带来潜在的灾难性的后果。嵌入设备以无人干预方式运行在很多领域的数千种关键任务或安全相关系统中,如制造、健康保健、运输、金融和军事等。虽然我们不假思索地依赖于这些嵌入系统,但任何一种嵌入系统都可能成为临时黑客、犯罪团伙、恐怖分子,甚至敌对政府分子的潜在目标。阻止这些攻击的重任就落在了系统设计者的肩上,他不仅要保证通过或保存在嵌入设备中的数据的安全,而且还要保护产品本身的知识产权。     

Temperament and substance abuse in schizophrenia: is there a relationship?

Dyspnea may be easily appreciated during exercise with dyspneic scales, but methodological standardisation still needs to be specified. Authors review the basic physiological mechanism relating dyspnea to indices obtained during a stress test. They propose to use the dyspnea/VE relationship. With the concept of dyspneic threshold (close to the ventilatory threshold) and the ramp that both could be modified (for instance by rehabilitation programmes including exercise training). Interpretation of dyspnea during an exercise test obviously needs to be integrated with other parameters studied during exercise.     

The development and application of a multiple wavelength illumination technique for the vision-based process monitoring of aero-structure riveting

Airframe riveting is a critical process that requires high levels of process monitoring and quality assurance due to the very high risk associated with the failure of such joints. This paper describes the development of the enabling technology developed for a machine vision-based process monitoring system. One of the key factors affecting the performance of a machine vision system is the quality of the lighting. In the application described in this paper the available lighting was severely limited by the confined space in which the system had to operate. The problem was also compounded by the reflective nature of the objects to be examined. The initial images obtained were not suitable for further processing due to the presence of significant shadows and specular reflections. A novel solution to this problem based on multiple wavelength illumination and signal processing is presented along with results from experimental trials of the approach.     

生物除臭滤池在污水厂污泥处理段的除臭效能

对采用天然有机滤料和合成无机滤料的生物除臭滤池在加拿大多伦多市Ash-bridge’s Bay污水厂污泥处理站的干化和转运段的应用效果进行了分析。详细介绍了污泥脱水工艺、臭气的产生及其组分，进而对软木树皮滤料和矿物合成永久性滤料的除臭效果进行了比较。还讨论了一些具体的运行经验，并采用动态模型对不同条件下的运行数据进行了分析。     

A new method for seed oil body purification and examination of oil body integrity following germination

Plant seeds store triacylglycerols as energy sources for germination and postgerminative growth of seedlings. The triacylglycerols are preserved in small, discrete, intracellular organelles called oil bodies. A new method was developed to purify seed oil bodies. The method included extraction, flotation by centrifugation, detergent washing, ionic elution, treatment with a chaotropic agent, and integrity testing by use of hexane. These processes subsequently removed non-specifically associated or trapped proteins within the oil bodies. Oil bodies purified by this method maintained their integrity and displayed electrostatic repulsion and steric hindrance on their surface. Compared with the previous procedure, this method allowed higher purification of oil bodies, as demonstrated by SDS-PAGE using five species of oilseeds. Oil bodies purified from sesame were further analyzed by two-dimensional gel electrophoresis and revealed two potential oleosin isoforms. The integrity of oil bodies in germinating sesame seedlings was examined by hexane extraction. Our results indicated that consumption of triacylglycerols reduced gradually the total amount of oil bodies in seedlings, whereas no alteration was observed in the integrity of remaining oil bodies. This observation implies that oil bodies in germinating seeds are not degraded simultaneously. It is suggested that glyoxisomes, with the assistance of mitochondria, fuse and digest oil bodies one at a time, while the remaining oil bodies are preserved intact during the whole period of germination.     

Isoforms p69 and p100 of 2'',5''-oligoadenylate synthetase induced differentially by interferons in vivo and in vitro

There is no better place to test life-saving resuscitation interventions than in the prehospital setting. Patients rarely survive cardiac arrest if resuscitation techniques have failed before leaving the scene. Also, paramedics are usually very experienced in key initial resuscitative techniques, and they routinely operate under strict paramilitary protocol, resulting in better study compliance. In addition, the large study populations that are derived from emergency medical services (EMS) systems lead to faster study completion and statistically stronger data. Most important, by reinforcing standardized care, rigidly scrutinized trials improve patient care, regardless of the effect of the study intervention. The success of productive EMS research centers requires routine communication between hospital and EMS administrators and their medical directors, designation of mutually acceptable data collectors who guarantee confidentiality, reciprocal exchange of study data provided as educational seminars to the hospitals, commitments to support the budget requests of an EMS program and appropriate system modifications, inclusion of EMS personnel in study design from the very beginning, prospective education of the medical community and media before protocol implementation, an authoritative grassroots medical director, and a paramedic supervisor system.     

Molecular mechanism of base excision repair of uracil-containing DNA in yeast cell-free extracts

Base excision repair (BER) constitutes a ubiquitous excision repair mechanism, which is responsible for the removal of multiple types of damaged and inappropriate bases in DNA. We have employed a yeast cell-free system to examine the biochemical mechanism of the BER pathway in lower eukaryotes. Using uracil-containing DNA as a model substrate, we demonstrate that yeast BER requires Apn1 protein, an Escherichia coli endonuclease IV homolog. In extracts of an apn1 deletion mutant, the 5'-incision at AP (apurinic/apyrimidinic) sites is not detectable, supporting the notion that yeast contains only one major 5'-AP endonuclease. The processing of the 5'-deoxyribose phosphate moieties was found to be a rate-limiting step. During BER of uracil-containing DNA, repair patch sizes of 1-5 nucleotides were detected, with single nucleotide repair patches predominant.