Spectral modeling of switched-mode power converters in discontinuous conduction mode

Analytical spectral modeling of switched-mode PWM converters, operating in the discontinuous conduction mode, is presented. The modeling approach is to derive analytical expressions of the converter output response using the extended Volterra functional series. Nonlinear frequency responses, including additional DC offset as well as significant subharmonic and higher harmonic components, due to large-signal perturbations of both the duty ratio and source voltage, are investigated. Their vulnerability to switching frequencies are also described. This modeling approach has been applied to various PWM converters, boost, buck and buck-boost types, operating in the discontinuous conduction mode, and the results are verified.published_or_final_versio

A totally Self-Checking Dynamic Asynchronous Datapath

This paper investigates the inherent totally self-checking (TSC) property of one type of dynamic asynchronous datapath based on Differential Cascode Voltage Logic (DCVSL). As a result, a totally self-checking dynamic asynchronous datapath architecture is proposed. It is simpler than other similar approaches and represents a new approach to fault tolerant design.published_or_final_versio

Ultra-short echo time cardiovascular magnetic resonance of atherosclerotic carotid plaque.

BACKGROUND: Multi-contrast weighted cardiovascular magnetic resonance (CMR) allows detailed plaque characterisation and assessment of plaque vulnerability. The aim of this preliminary study was to show the potential of Ultra-short Echo Time (UTE) subtraction MR in detecting calcification. METHODS: 14 ex-vivo human carotid arteries were scanned using CMR and CT, prior to histological slide preparation. Two images were acquired using a double-echo 3D UTE pulse, one with a long TE and the second with an ultra-short TE, with the same TR. An UTE subtraction (DeltaUTE) image containing only ultra-short T2 (and T2*) signals was obtained by post-processing subtraction of the 2 UTE images. The DeltaUTE image was compared to the conventional 3D T1-weighted sequence and CT scan of the carotid arteries. RESULTS: In atheromatous carotid arteries, there was a 71% agreement between the high signal intensity areas on DeltaUTE images and CT scan. The same areas were represented as low signal intensity on T1W and areas of void on histology, indicating focal calcification. However, in 15% of all the scans there were some incongruent regions of high intensity on DeltaUTE that did not correspond with a high intensity signal on CT, and histology confirmed the absence of calcification. CONCLUSIONS: We have demonstrated that the UTE sequence has potential to identify calcified plaque. Further work is needed to fully understand the UTE findings

Invasive Acremonium falciforme infection in a patient with severe combined immunodeficiency [7]

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Nonparametric estimation in economics: Bayesian and frequentist approaches

© 2017 Wiley Periodicals, Inc. We review Bayesian and classical approaches to nonparametric density and regression estimation and illustrate how these techniques can be used in economic applications. On the Bayesian side, density estimation is illustrated via finite Gaussian mixtures and a Dirichlet Process Mixture Model, while nonparametric regression is handled using priors that impose smoothness. From the frequentist perspective, kernel-based nonparametric regression techniques are presented for both density and regression problems. Both approaches are illustrated using a wage dataset from the Current Population Survey. WIREs Comput Stat 2017, 9:e1406. doi: 10.1002/wics.1406. For further resources related to this article, please visit the WIREs website

A report on a randomly sampled questionnaire survey about renal stone disease in Hong Kong

Objectives: To investigate the prevalence and characteristics of patients with renal stone in Hong Kong, and awareness of corresponding prevention strategies. Design: Telephone public survey. Setting: Hong Kong community. Participants: A public telephone survey concerning the occurrence of renal stone disease and the public awareness of the condition was performed. Respondents whose telephone numbers were randomly selected by computer and the family member of the household who had the closest birthday to that date was chosen for interview. Data collected were further adjusted for the gender and age distribution of the Hong Kong population in mid-2007. Results: A total of 1010 Hong Kong citizens aged 18 years or above were successfully interviewed in November 2007. Among them, 25 respondents themselves had a history of renal stones, yielding a point prevalence of 2.5%. In addition, 70 respondents had family members with a history of renal stones, yielding an estimated household point prevalence of 6.9%. Stone patients were mainly older, male, and imbibed less fluids than the average for all respondents. The public's concepts with regard to the diet necessary and the importance of taking more fluid to prevent stone formation was poor. Conclusion: Hong Kong has a relatively low prevalence of renal stone disease, compared to neighbouring areas. However, the local public and affected patients had little knowledge and awareness about this important health problem.published_or_final_versio

Cutout of proximal femoral nail antirotation resulting from blocking of the gliding mechanism during fracture collapse

The proximal femoral nail antirotation had been successful in treating unstable trochanteric fractures. Previous studies have shown technical problems such as unsatisfactory fracture reduction, poor insertion technique, and poor blade position leading to complications such as cutout. We present a case of proximal femoral nail antirotation cutout resulting from the blocking of the gliding mechanism during fracture collapse by the lateral cortex. The trochanteric fracture had not healed on presentation and there was significant acetabulum protrusion of the device. Thus, a cemented total hip arthroplasty was required. Copyright © 2011 by Lippincott Williams & Wilkins.postprin

Resection of phaeochromocytoma extending into the right atrium in a patient with multiple endocrine neoplasia type 2A

We report the first case of successful surgical resection of a malignant phaeochromocytoma with tumour extension into vena cava and right atrium in a patient with multiple endocrine neoplasia type 2A. A 21-year-old woman with genetic confirmation of multiple endocrine neoplasia type 2A syndrome was diagnosed with a very rare case of malignant phaeochromocytoma with tumour thrombus extension into vena cava and right atrium causing Budd-Chiari syndrome. It posed a challenge to the surgeons with regard to complete tumour resection and vascular control. Reviewing the limited literature, surgical resection by means of cardiopulmonary bypass with hypothermic circulatory arrest has been reported with success in phaeochromocytoma with advance vascular involvement. Adopting this approach, adrenalectomy with complete thrombus excision by inferior vena cava exploration and right atriotomy were performed successfully by a multidisciplinary team.published_or_final_versio

Increased gray matter volume in the right angular and posterior parahippocampal gyri in loving-kindness meditators

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Using bevacizumab in the fight against malignant glioma: First results in Asian patients

Objectives To investigate the efficacy and safety profile of bevacizumab in combination with irinotecan in Hong Kong Chinese patients with recurrent malignant glioma and to determine whether their response differed from that reported in other populations. Design Retrospective study. Setting Two private clinics and a public hospital in Hong Kong. Patients Fourteen individuals who presented with recurrent glioma presenting to the hospital between November 2005 and November 2009. Intervention Salvage therapy with bevacizumab (10 mg/kg) and irinotecan (125 mg/m 2 [340 mg/m 2 for those taking enzyme-inducing antiepileptic drugs]) on a 14-day schedule. Results A radiological response was observed in 12 (86%) of the patients, four (33%) of whom had a complete response. The median progression-free survival was 6 (range, 1-15) months; 71% remained progression-free at 6 months. The median overall survival was 18 (range, 9-61) months. The most common adverse events during the bevacizumab and irinotecan treatment period were haematological; five patients had grade 2/3 adverse events. Pulmonary embolism occurred in two patients, one of whom died. Intracranial haemorrhage was not detected in any of the 14 treated patients. Conclusions Bevacizumab plus irinotecan was at least as effective at treating Chinese patients with recurrent glioma as previously reported in clinical trials in different patient populations.published_or_final_versio