The turmoil around the drug-eluting stents

Of 141 hospital survivors after intracardiac repair of tetralogy of Fallot, eight died suddenly 6–23 years later. Compared with the other 133 patients, these eight were older at operation, with higher post-repair systolic right ventricular pressure and more often complete atrioventricular block; ventricular arrhythmia was diagnosed before death in three cases. In follow-up totalling 2255 patient years, the linearized rate of sudden death was 0.35%/year. The instantaneous risk of sudden death showed continuous increase with the length of follow-up. Of 80 survivors electrocardiographically evaluated 13–26 (median 20) years postoperatively, none had complete block, but 79 had complete right bundle branch block, including seven with left anterior hemiblock. Ventricular extrasystoles were recorded in 1% at rest, in 34% during exercise and in 83% during 24-hour ambulatory monitoring, with Lown Grade ≥II in 27%. Old age and possibly presence of fibrosis and/or fibroelastosis in right ventricular outflow tract muscle correlated independently with high Lown Grade. A patient with Lown grade III died suddenly 2 years after our follow-up. Old age at repair thus was associated with increased risk of late sudden death and with frequent ventricular arrhythmia in long-term survivors.     

Spinal epidural abscesses – The role for non-operative management: A systematic review

BackgroundSpinal Epidural Abscesses (SEAs) are traditionally seen as a surgical emergency. However, SEAs can be discovered in entirely asymptomatic patients. This presents a dilemma for the attending clinician as to whether to subject these patients to significant surgery. This systematic review updates the evidence surrounding the efficacy of non-operative SEA management by means of intravenous antibiotics ± radiologically-guided aspiration.Aims1. To assess failure rates of medical therapy for SEA. The absolute definition of ‘failure’ used by the study was recorded, and comparisons made. 2. To review of risk factors for success/failure of medical treatment for SEA.MethodsA database search with the MESH term ‘epidural abscess’ and keywords [‘treatment’ OR ‘management’] were used.Results14 studies were included. The number of SEA patients managed non-operatively ranged from 19 to 142. There was significant heterogeneity across the studies. Pooled Failure of Medical Therapy (FMT) (defined as any poor outcome) was 29.40%. When FMT = mortality the pooled rate was 11.49%. Commonly cited risk factors for FMT included acute neurological compromise, diabetes mellitus, increasing age and Staphylococcus aureus.ConclusionSEA will always be a condition mostly managed surgically. Despite this, there is growing evidence that non-operative management can be possible in the correct patients. The key is in patient selection – patients with any of the above-mentioned risk factors have the potential to deteriorate further on medical treatment and have a worse outcome than if they had undergone emergency surgery straight away. Ongoing research will hopefully further investigate this crucial step.     

Challenges and opportunities of utilizing municipal solid waste as alternative building materials for sustainable development goals: A review

Strict environmental concern, depletion, and price hike of building construction materials are driving scientific studies for the search of alternative materials for building construction. To this end sustainable building materials could be a fruitful solution. This review aims to discern the environmental efficacy of solid waste management (SWM) and its relationship with four stimuli i.e., economic structure, regulatory structure, science, and time. The study also highlights the investigation of governance network to figure out the regulatory structure and governance of waste management. Extensive details on solid waste with their sources, recycling potential and their current utilization for substantial development are outlined. A throughout of the production process, properties, advantages, disadvantages, and the global economy of building material developed through recycling of solid waste are discussed. This article also deals with the sustainability, social, and environmental impact of green building materials. The study identifies the future direction for the effective utilization of solid waste for developing building materials. Further, the scope of the present also focusses on the concept of circular economy for developing construction materials through recycling of solid waste, which provides an easy reference for solid waste processing towards sustainability.     

Effects of clonidine on breathing during sleep and susceptibility to central apnoea

We hypothesized that administration of clonidine would decrease the hypocapnic apnoeic threshold (HAT) and widen the CO₂ reserve during non-REM sleep.     

Review of the Potential of the Ni/Cu Plating Technique for Crystalline Silicon Solar Cells

Developing a better method for the metallization of silicon solar cells is integral part of realizing superior efficiency. Currently, contact realization using screen printing is the leading technology in the silicon based photovoltaic industry, as it is simple and fast. However, the problem with metallization of this kind is that it has a lower aspect ratio and higher contact resistance, which limits solar cell efficiency. The mounting cost of silver pastes and decreasing silicon wafer thicknesses encourages silicon solar cell manufacturers to develop fresh metallization techniques involving a lower quantity of silver usage and not relying pressing process of screen printing. In recent times nickel/copper (Ni/Cu) based metal plating has emerged as a metallization method that may solve these issues. This paper offers a detailed review and understanding of a Ni/Cu based plating technique for silicon solar cells. The formation of a Ni seed layer by adopting various deposition techniques and a Cu conducting layer using a light induced plating (LIP) process are appraised. Unlike screen-printed metallization, a step involving patterning is crucial for opening the masking layer. Consequently, experimental procedures involving patterning methods are also explicated. Lastly, the issues of adhesion, back ground plating, process complexity and reliability for industrial applications are also addressed.     

Performance Evaluation of Time-Frequency Distributions for ECG Signal Analysis

The non-stationary and multi-frequency nature of biomedical signal activities makes the use of time-frequency distributions (TFDs) for analysis inevitable. Time-frequency analysis provides simultaneous interpretations in both time and frequency domain enabling comprehensive explanation, presentation and interpretation of electrocardiogram (ECG) signals. The diversity of TFDs and specific properties for each type show the need to determine the best TFD for ECG analysis. In this study, a performance evaluation of five TFDs in term of ECG abnormality detection is presented. The detection criteria based on extracted features from most important ECG signal components (QRS) to detect normal and abnormal cases. This is achieved by estimating its energy concentration magnitude using the TFDs. The TFDs analyse ECG signals in one-minute interval instead of conventional time domain approach that analyses based on beat or frame containing several beats. The MIT-BIH normal sinus rhythm ECG database total records of 18 long-term ECG sampled at 128 Hz have been analysed. The tested TFDs include Dual-Tree Wavelet Transform, Spectrogram, Pseudo Wigner-Ville, Choi-Williams, and Born-Jordan. Each record is divided into one-minute slots, which is not considered previously, and analysed. The sample periods (slots) are randomly selected ten minutes interval for each record. This result with 99.44% detection accuracy for 15,735 ECG beats shows that Choi-Williams distribution is most reliable to be used for heart problem detection especially in automated systems that provide continuous monitoring for long time duration.