An Ultra-Wide Load Range Voltage Converter Using Proactive Phase Frequency Modulation for IoT Sensors.

Modern sensor nodes have multiple operating states, which causes a conventional voltage converter to perform poorly over a wide load range of the operating states. This paper proposes a voltage converter whose switching frequency and output voltage are proactively adjusted to maintain high conversion efficiency. This allows the converter to exploit a wider frequency range to cover a wide load range. In addition, the proposed converter uses multiple smaller capacitor banks and employs multiphase operation to provide low output ripple voltage. A distributed topology for non-overlapping signal generation is proposed and used in the converter to minimize the number of wires running from connecting the controller to the converter. The proposed voltage converter has been implemented in a chip using a 0.13 um CMOS process. The measurement results demonstrate the ability to support a wide load range of 10 µA to 10 mA, for switching frequencies ranging from 100 kHz to 200 MHz, while providing an efficiency of above 80%.

Double-blind randomised controlled trial of vitamin D3 supplementation for the prevention of acute respiratory infection in older adults and their carers (ViDiFlu).

RATIONALE: Low-dose vitamin D supplementation is already recommended in older adults for prevention of fractures and falls, but clinical trials investigating whether higher doses could provide additional protection against acute respiratory infection (ARI) are lacking. OBJECTIVE: To conduct a clinical trial of high-dose versus low-dose vitamin D3 supplementation for ARI prevention in residents of sheltered-accommodation housing blocks ('schemes') and their carers in London, UK. MEASUREMENTS AND METHODS: Fifty-four schemes (137 individual participants) were allocated to the active intervention (vitamin D3 2.4 mg once every 2 months +10 µg daily for residents, 3 mg once every 2 months for carers), and 54 schemes with 103 participants were allocated to control (placebo once every 2 months +vitamin D3 10 µg daily for residents, placebo once every 2 months for carers) for 1 year. Primary outcome was time to first ARI; secondary outcomes included time to first upper/lower respiratory infection (URI/LRI, analysed separately), and symptom duration. MAIN RESULTS: Inadequate vitamin D status was common at baseline: 220/240 (92%) participants had serum 25(OH)D concentration <75 nmol/L. The active intervention did not influence time to first ARI (adjusted HR (aHR) 1.18, 95% CI 0.80 to 1.74, p=0.42). When URI and LRI were analysed separately, allocation to the active intervention was associated with increased risk of URI (aHR 1.48, 95% CI 1.02 to 2.16, p=0.039) and increased duration of URI symptoms (median 7.0 vs 5.0 days for active vs control, adjusted ratio of geometric means 1.34, 95% CI 1.09 to 1.65, p=0.005), but not with altered risk or duration of LRI. CONCLUSIONS: Addition of intermittent bolus-dose vitamin D3 supplementation to a daily low-dose regimen did not influence risk of ARI in older adults and their carers, but was associated with increased risk and duration of URI. TRIAL REGISTRATION NUMBER: clinicaltrials.gov NCT01069874.

Agenesis of right diaphragm in the adults: a diagnostic dilemma.

Diaphragmatic agenesis is the most extreme form of congenital diaphragmatic defect, and it may be unilateral or bilateral. Diaphragmatic agenesis is a rare diagnosis, typically made early in infancy and is generally associated with other genetic anomalies, especially anueploidy syndromes. It is associated with a high mortality, if not treated in infancy. However, a few patients have survived till adulthood. In this report, we describe the case of an adult female who presented with progressive shortness of breath during third trimester of pregnancy with complete agenesis of the right side of the diaphragm. A new diaphragm was created using polypropylene mesh after which she improved symptomatically and the lung showed good expansion.

Vitamin A and carotenoids and the risk of Parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: Vitamin A and carotenoids are involved in signalling pathways regulating gene expression in many organs, including the brain. The dopaminergic system is a target of retinoic acid action in the central nervous system. The aim of this review is to assess the epidemiological evidence on the association between blood levels or dietary intakes of vitamin A and carotenoids and risk of Parkinson's disease (PD). METHODS: PubMed and ISI Web of Science were searched for relevant papers from 1990 to April 2013. Data reported in epidemiological studies assessing the association between vitamin A and/or carotenoids (α-carotene, ß-carotene, ß-cryptoxanthin, lutein, lycopene, zeaxanthin and canthaxanthin) and PD were extracted for a narrative synthesis and meta-analysis. RESULTS: Thirteen papers were included out of a total of 362 potentially relevant; of these, eight contributed to the meta-analysis. No statistically significant pooled estimate between micronutrient and PD was detected. Forest plots suggest possible non-significant inverse pooled estimates of α-carotene and ß-carotene and risk of PD. A significant association between lutein intake and PD risk was detected in case-control studies only. CONCLUSIONS: Data published to date are insufficient for drawing definite conclusions about the epidemiological evidence on the association between blood levels or dietary intakes of vitamin A and carotenoids and the risk of PD. Results should be interpreted particularly cautiously given the limitation of the present meta-analysis and the potential publication bias. Authors are urged to follow more closely the recommendations for reporting epidemiological studies in order to enhance the capacity for synthesising the evidence.

Suprapubic Fecal Fistula Due To Richter's Inguinal Hernia: A Case Report and Review of Literature.

We encountered a 55-year-old man, who presented with an orifice in the suprapubic region, through which fecal material was discharged. On physical examination, the patient was unstable. After resuscitation, thorough evaluation, and laboratory and imaging investigations, he underwent an exploratory laparotomy. The ileum was entrapped at the deep inguinal ring, and there was some pus in the pelvic cavity. The purulent material was cleaned, and anastomosis was done after the resection of the defective ileal segment. In view of the rarity of this presentation and the paucity of published articles, this case is reported here.

Primary hyperparathyroidism having multiple Brown tumors mimicking malignancy.

Primary hyperparathyroidism is a disease characterized by excessive secretion of parathormone. During the course of this disease, bone loss occurs, particularly depending on resorption of the skeletal system. One of the complications of primary hyperparathyroidism is fibrotic, cystic bony changes which is called Brown tumor. Skeletal manifestations in the form of Brown tumors are rare and according to literature occur in less than 2% of patients suffering from any form of hyperparathyroidism. Such rare and multiple benign lesions may simulate a malignant neoplasm and pose a real challenge for the clinician in its differential diagnosis. We present a case of a 23-year-old Indian woman who was evaluated for multiple lytic expansile lesions with a strong suspicion of malignancy and fibrous dysplasia but turned out to be a case of primary hyperparathyroidism.

Post-traumatic synchronous twin inter-muscular abdominal and diaphragmatic hernias: a rare presentation.

Simultaneous occurrence of traumatic abdominal wall hernia (TAWH) and traumatic diaphragmatic hernia (TDH) is uncommon. Our report documents the rare delayed presentation of simultaneous occurrence of TAWH and TDH in a patient who sustained a bicycle handlebar injury as a consequence of the bicycle he was riding colliding with a motorbike in a road-traffic accident. Excellent outcome could be achieved in this patient with surgical repair without requiring the use of a mesh.