318 research outputs found
Electrochemical Carbonylation of Organoiron Methyl Complex: A Study of Reaction Intermediates
The one-electron reduction of CpFe(CO)2CH3 has been investigated by voltammetry and Fourier transform IR spectroelectrochemistry. The reduction initiates the insertion of CO ligand in the FeCH3 bond. The dissociation of a CO group proceeds in a parallel reaction. Reaction intermediates, the acyl derivative and released CO, form the radical anion of a complex CpFe(CO)2(COCH3) which is able to reduce the parent compound. The reversible redox potential − 1.8 V of CpFe(CO)2(COCH3) allows the regeneration of its radical anion which drives a catalytic cycle. The lifetime of intermediates is shortened by side reactions, one of which is the migration of the acyl group from the central atom to the cyclopentadienyl ring. This explains the apparent discrepancy between products observed in preparative scale electrolysis and the absence of catalytic effects in routine voltammetric experiments
Benchmarking the SHL Recognition Challenge with classical and deep-learning pipelines
In this paper we, as part of the Sussex-Huawei Locomotion-Transportation (SHL) Recognition Challenge organizing team, present reference recognition performance obtained by applying various classical and deep-learning classifiers to the testing dataset. We aim to recognize eight modes of transportation (Still, Walk, Run, Bike, Bus, Car, Train, Subway) from smartphone inertial sensors: accelerometer, gyroscope and magnetometer. The classical classifiers include naive Bayesian, decision tree, random forest, K-nearest neighbour and support vector machine, while the deep-learning classifiers include fully-connected and convolutional deep neural networks. We feed different types of input to the classifier, including hand-crafted features, raw sensor data in the time domain, and in the frequency domain. We employ a post-processing scheme to improve the recognition performance. Results show that convolutional neural network operating on frequency domain raw data achieves the best performance among all the classifiers
Structure, bonding and morphology of hydrothermally synthesised xonotlite
The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies
The ecacy of an oxidation pond in mineralizing some industrial waste products with special reference to¯uorene degradation: a case study
Abstract The ecacy of the oxidation pond on the outskirts of the 10th of Ramadan, the main industrial city, in Egypt was examined. Samples of wastewater collected from the inlet and the outlet were screened for some priority pollutants. Acenaphthene and¯uor-ene were the most frequently detected polycyclic aromatic hydrocarbons, while dimethyl phthalate was the most frequently detected phthalate ester. The spectrum of pollutants, their concentrations and frequencies were similar in the inlet and the outlet, indicating an inferior mineralization capability of the pond. Several degradative bacterial strains were isolated from the pond and grown on M56 minimal media supplemented with dierent pollutants as the carbon source. The ecacy of pure and mixed cultures to break down¯uorene, the most frequently detected pollutant was examined. Fluorene degradation was fast in the ®rst 10 days, then followed by a slow phase. Mixed culture had a higher rate of¯uorene degradation in comparison to pure cultures. High performance liquid chromatography analysis of¯uorene degradation showed three degradative metabolites. But GC/MS analysis detected one compound, identi®ed as acetamide. The present work has indicated the poor ecacy of the pond. Lack of primary treatment of industrial euent at factory level, coupled with shock loads of toxicants that may damage the microorganisms and their degradative capabilities are presumably main factors behind such inferior performance. Moreover, the type of pollutants discharged into the pond tend to¯uctuate and change depending on the rate from the factories discharge and work shifts. Such irregular feeding of persistent pollutants may have led to a wash out of specialized strains of bacteria capable to degrade such persistent pollutants.
Penile hair coil strangulation of the child
AbstractWe report the case of a child with a delayed presentation of penile strangulation with a coil of hair that resulted in a complete transection of the urethra. Hair coil strangulation of the penis is uncommon. It is also known as penile Tourniquet syndrome. It has been reported with circumcised and uncircumcised penises and it can lead to serious complications like the amputation of the penis. Prompt diagnosis and treatment are necessary to prevent complications
Enabling Reproducible Research in Sensor-Based Transportation Mode Recognition With the Sussex-Huawei Dataset
Transportation and locomotion mode recognition from multimodal smartphone sensors is useful to provide just-in-time context-aware assistance. However, the field is currently held back by the lack of standardized datasets, recognition tasks and evaluation criteria. Currently, recognition methods are often tested on ad-hoc datasets acquired for one-off recognition problems and with differing choices of sensors. This prevents a systematic comparative evaluation of methods within and across research groups. Our goal is to address these issues by: i) introducing a publicly available, large-scale dataset for transportation and locomotion mode recognition from multimodal smartphone sensors; ii) suggesting twelve reference recognition scenarios, which are a superset of the tasks we identified in related work; iii) suggesting relevant combinations of sensors to use based on energy considerations among accelerometer, gyroscope, magnetometer and GPS sensors; iv) defining precise evaluation criteria, including training and testing sets, evaluation measures, and user-independent and sensor-placement independent evaluations. Based on this, we report a systematic study of the relevance of statistical and frequency features based on information theoretical criteria to inform recognition systems. We then systematically report the reference performance obtained on all the identified recognition scenarios using a machine-learning recognition pipeline. The extent of this analysis and the clear definition of the recognition tasks enable future researchers to evaluate their own methods in a comparable manner, thus contributing to further advances in the field. The dataset and the code are available online
Intérêt de la technique de Koyanagi dans le traitement de l’hypospadias posterieurchez l’enfant
No Abstrac
Non-infectious Complications of Peritoneal Dialysis among Sudanese Patients: Five Years Experience
Introduction: The technique of Continuous Ambulatory Peritoneal Dialysis (CAPD) is known to be associated with various infectious and non-infectious complications. The latter term includes anatomical/mechanical complications as well as hemoperitoneum, inflow pain, electrolyte disturbances, metabolic derangements and delayed gastric emptying.
Methods: We retrospectively evaluated all patients who were maintained on CAPD for a minimum of 90 days in Sudan, in the period between May 2005 and Apr 2010. We examined the incidence of various non-infectious complications and their possible associations.
Results: The analysis included 296 patients including 71 children (24%). Males constituted 62.2% of the study population and 13.9% were diabetic. The incidence per 100 patient-years of various non-infectious complications was as follows: hypokalemia (30.4), catheter dysfunction (10.8), dialysate leak (5.3), hernia (4.7), hemorrhagic effluent (4.7), inflow pain (2.3), upper gastrointestinal symptoms (2) and cuff extrusion (0.9). Catheter block and hernia were diagnosed with a median duration after catheter insertion of 6 and 7.5 months, respectively. Catheter block was significantly more prevalent among children (22.5% versus 9.3%; P = 0.006). A high body mass index (BMI) was the only identified independent predictor for leak (OR 1.4, P = 0.005). More than half of the 16 hernias were umbilical, and four of the five inguinal hernias were bilateral. Non-infectious complications were responsible for 32% of technique failures.
Conclusion: Non-infectious complications were fairly common among our CAPD patients and led to catheter removal in a considerable number of patients. Care is, therefore, needed to screen CAPD patients for these complications in order to timely address and manage problems.
Keywords: Peritoneal Dialysis; Non-infectious Complications; Sudan; Herni
Improved Survival from Ovarian Cancer in Patients Treated in Phase III Trial Active Cancer Centres in the UK
Aims: Ovarian cancer is the principal cause of gynaecological cancer death in developed countries, yet overall survival in the UK has been reported as being inferior to that in some Western countries. As there is a range of survival across the UK we hypothesised that in major regional centres, outcomes are equivalent to the best internationally. Materials and methods: Data from patients treated in multicentre international and UK-based trials were obtained from three regional cancer centres in the UK; Manchester, University College London and Leeds (MUL). The median progression-free survival (PFS) and overall survival were calculated for each trial and compared with the published trial data. Normalised median survival values and the respective 95% confidence intervals (ratio of pooled MUL data to trial median survival) were calculated to allow inter-trial survival comparisons. This strategy then allowed a comparison of median survival across the UK, in three regional UK centres and in international centres. Results: The analysis showed that the trial-reported PFS was the same in the UK, in the MUL centres and in international centres for each of the trials included in the study. Overall survival was, however, 45% better in major regional centre-treated patients (95% confidence interval 9–73%) than the median overall survival reported in UK trials, whereas the median overall survival in MUL centres equated with that achieved in international centres. Conclusion: The data suggest that international survival statistics are achieved in UK regional cancer centres
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