Catheters and Infections

Catheters are used for effective drainage of the bladder, either temporally or permanently, in the presence of physiological and anatomical defects or obstruction of the lower urinary tract. Catheters are used for a variety of reasons, as follows, to maintain bladder drainage during and following surgery or epidurals anesthesia for minimizing and prevention of the risk of distension injuries; investigations, for accurate urine output measurement, and measurement of post-micturition residuals; treatments, to relieve urinary retention or for chemotherapy instillation; intractable incontinence, as the final option for containment

Current Trends in Urinary Diversion in Men

Prior to the introduction of the ileal conduit more than four decades ago, the options for urinary diversion after cystectomy were extremely limited. Direct cutaneous anastomoses of the collecting system (cutaneous pyelostomies, ureterostomies) offered patients a short-term diversion, but the benefits were outweighed by significant complications: recession or stenosis of the stoma. The first choice of diversion was the ureterosigmoidostomy with or without antireflux technique. Then it fell in popularity and was replaced with continent/non-continent uretero-ileo-cutaneous diversions. Only in the last years the continent orthotopic neobladder has been widely employed as first procedure choice. At present, patients can be offered a non-continent cutaneous diversion, a continent cutaneous diversion or an orthotopic neobladder urinary reconstructio

Detection of LDDoS Attacks Based on TCP Connection Parameters

Low-rate application layer distributed denial of service (LDDoS) attacks are both powerful and stealthy. They force vulnerable webservers to open all available connections to the adversary, denying resources to real users. Mitigation advice focuses on solutions that potentially degrade quality of service for legitimate connections. Furthermore, without accurate detection mechanisms, distributed attacks can bypass these defences. A methodology for detection of LDDoS attacks, based on characteristics of malicious TCP flows, is proposed within this paper. Research will be conducted using combinations of two datasets: one generated from a simulated network, the other from the publically available CIC DoS dataset. Both contain the attacks slowread, slowheaders and slowbody, alongside legitimate web browsing. TCP flow features are extracted from all connections. Experimentation was carried out using six supervised AI algorithms to categorise attack from legitimate flows. Decision trees and k-NN accurately classified up to 99.99% of flows, with exceptionally low false positive and false negative rates, demonstrating the potential of AI in LDDoS detection

Durability of a recombination catalyst-based membrane-electrode assembly for electrolysis operation at high current density

Hydrogen production through polymer electrolyte membrane water electrolysis was investigated at high current density (4 A cm-2). A PtCo recombination catalyst-based membrane-electrode assembly (MEA) was assessed in terms of performance, efficiency and durability. The electrolysis cell consisted of a thin (50 µm) perfluorosulfonic acid membrane and low platinum group metals (PGM) catalyst loadings (0.6 mgMEA PGM cm-2). An unsupported PtCo catalyst was successfully integrated in the anode. A composite catalytic layer made of IrRuOx and PtCo assisted both oxygen evolution and oxidation of hydrogen permeated through the membrane. The cell voltage for the recombination catalyst-based MEA was about 30 mV lower than the bare MEA during a 3500 h durability test. The modified MEA showed low performance losses during 3500 hours operation at high current density (4 A cm-2) with low catalyst loadings. A decay rate of 9 µV/h was observed in the last 1000 hours. These results are promising for decreasing the capital costs of polymer electrolyte membrane electrolysers. Moreover, the stable voltage efficiency of about 80% vs. the high heating value (HHV) of hydrogen at 4 A cm-2, here achieved, appears very promising to decrease operating expenditures

Investigation of a Pt3Sn/C Electro-Catalyst in a Direct Ethanol Fuel Cell Operating at Low Temperatures for Portable Applications

A 20% Pt3Sn/C catalyst was prepared by reduction with formic acid and used in a direct ethanol fuel cell at low temperatures. The electro-catalytic activity of this bimetallic catalyst was compared to that of a commercial 20% Pt/C catalyst. The PtSn catalyst showed better results in the investigated temperature range (30 degrees-70 degrees C). Generally, Sn promotes ethanol oxidation by adsorption of OH species at considerably lower potentials compared to Pt, allowing the occurrence of a bifunctional mechanism. The bimetallic catalyst was physico-chemically characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. The presence of SnO2 in the bulk and surface of the catalyst was observed. It appears that SnO2 can enhance the ethanol electro-oxidation activity at low potentials due to the supply of oxygen-containing species for the oxidative removal of CO and CH3CO species adsorbed on adjacent Pt active sites.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES