Anti-corrosive siloxane coatings for improved long-term performance of supercapacitors with an aqueous electrolyte

This paper reports on the impact that the corrosion of the stainless steel current collectors has on the performance fade of a symmetric, carbon/carbon electrochemical capacitor, operating with an aqueous electrolyte (1M Na2SO4). The results obtained by applying electrochemical ageing protocols (voltage-holding tests) confirm that the current collector of the positive electrode undergoes tremendous degradation during 200 h in the charged state. To prevent the detrimental impact of the corrosion, a hydrophobic siloxane coating has been successfully applied. In the case of siloxane-protected current collectors that are subjected to identical ageing protocols, no significant deterioration in the electrochemical capacitor performance was observed. The siloxane coating reduces the electrochemical corrosion rate of 316L stainless steel significantly, as the potentiodynamic polarization tests and the electrochemical impedance spectroscopy results show. The presence of the coating is demonstrated by the water contact angle measurements, atomic force microscopy and energy-dispersive X-ray spectroscopy analysis

Systematic review and meta-analysis of randomized clinical trials comparing efficacy and safety outcomes of insulin glargine with NPH insulin, premixed insulin preparations or with insulin detemir in type 2 diabetes mellitus

AIMS: A variety of basal insulin preparations are used to treat patients with type 2 diabetes mellitus (T2DM). We aimed to summarize scientific evidence on relative efficacy and safety of insulin glargine (IGlar) and other insulins in T2DM. METHODS: A systematic review was carried out in major medical databases up to December 2012. Relevant studies compared efficacy and safety of IGlar, added to oral drugs (OAD) or/and in combination with bolus insulin, with protamine insulin (NPH) or premixed insulin (MIX) in the same regimen, as well as with insulin detemir (IDet), in T2DM. Target HbA1c level without hypoglycemic events was considered the primary endpoint. RESULTS: Twenty eight RCTs involving 12,669 T2DM patients followed for 12–52 weeks were included in quantitative analysis. IGlar + OAD use was associated with higher probability of reaching target HbA1c level without hypoglycemia as compared to NPH + OAD (RR = 1.32 [1.09, 1.59]) or MIX without OAD (RR = 1.61 [1.22, 2.13]) and similar effect as IDet + OAD (RR = 1.07 [0.87, 1.33]) and MIX + OAD (RR = 1.09 [0.86, 1.38]). IGlar + OAD demonstrated significantly lower risk of symptomatic hypoglycemia as compared to NPH + OAD (RR = 0.89 [0.83, 0.96]), MIX + OAD (RR = 0.75 [0.68, 0.83]) and MIX without OAD(RR = 0.75 [0.68, 0.83]), but not with IDet + OAD (RR = 0.99 [0.90, 1.08]). In basal-bolus regimens, IGlar demonstrated similar proportion of T2DM patients achieving target HbA1c as compared to NPH (RR = 1.14 [0.91, 1.44]) but higher than MIX (RR = 1.26 [1.12, 1.42) or IDet (RR = 1.38 [1.11, 1.72]). The risk of severe hypoglycemia was lower in IGlar than in NPH (RR = 0.77 [0.63, 0.94]), with no differences in comparison with MIX (RR = 0.74 [0.46, 1.20]) and IDet (RR = 1.10 [0.54, 2.25]). IGlar + OAD has comparable safety profile to NPH, with less frequent adverse events leading to treatment discontinuation than MIX + OAD (RR = 0.41 [0.22, 0.76]) and IDet + OAD (RR = 0.40 [0.24, 0.69]). Also severe adverse reactions were less common for IGlar + OAD when compared to MIX + OAD (RR = 0.71 [0.52; 0.98]). CONCLUSION: For the majority of examined efficacy and safety outcomes, IGlar use in T2DM patients was superior or non-inferior to the alternative insulin treatment options. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00592-014-0698-4) contains supplementary material, which is available to authorized users

Effect of accelerated electron beam on mechanical properties of human cortical bone: influence of different processing methods

Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks. Accelerated EB, in contrast to more often used gamma photons, is a form of ionizing radiation that is characterized by lower penetration, however it is more effective in producing ionisation and to reach the same level of sterility, the exposition time of irradiated product is shorter. There are several factors, including dose and temperature of irradiation, processing conditions, as well as source of irradiation that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect e-beam irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors, aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as e-beam irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress–strain curves examined by univariate analysis are described. Based on multivariate analysis, including all groups, it was found that temperature of e-beam irradiation and defatting had no consistent significant effect on evaluated mechanical parameters of compact bone rings. In contrast, irradiation with both doses significantly decreased the ultimate strain and its derivative toughness, while not affecting the ultimate stress (bone strength). As no deterioration of mechanical properties was observed in the elastic region, the reduction of the energy absorption capacity of irradiated bone rings apparently resulted from changes generated by irradiation within the plastic strain region

Superficial femoral vein versus extra-anatomic bypass in treatment of vascular prosthesis infection

Wstęp. Celem pracy jest ocena wyników leczenia zakażeń protez naczyniowych, w których zastosowano pomost pozaanatomiczny oraz żyłę udową powierzchowną jako pomost naczyniowy w miejsce po usuniętej protezie. Materiał i metody. W latach 2001–2003 na Oddziale Chirurgii Naczyniowej Kliniki Kardiochirurgii AM w Gdańsku przeprowadzono 1580 operacji z zakresu chirurgii naczyniowej. W 14 przypadkach operację wykonano z powodu zakażenia protezy. U 6 chorych w celu odtworzenia krążenia w kończynach zastosowano pomost wykonany z żył udowych powierzchownych, w tym u 4 pacjentów w leczeniu zakażenia pomostu aortalno-dwuudowego, u 1 — aortalno-udowego i u 1 — pachowo-udowego. W ostatnim przypadku dodatkowo wykorzystano udrożnioną tętnicę udową powierzchowną (grupa I). U wszystkich chorych z tej grupy pomost przeprowadzono przez kanał po usuniętej protezie. U 8 chorych zastosowano pomost pozaanatomiczny (grupa II). W 6 przypadkach wykonano pomost pachowo-dwuudowy, a w 2 — pomost pachowopodkolanowy. U wszystkich chorych zabieg odtwarzający krążenie w kończynie poprzedzał częściowe lub całkowite usunięcie protezy, a cała procedura została wykonana jednoczasowo. Grupa I (n = 6) Grupa II (n = 8) Okres obserwacji (miesiące) 4–18 (średnio 11,4) 2–24 (średnio 14,5) Śmiertelność 1 (16,6%) 2 (25%) Amputacje 0 1 Reperacje 2 1 U żadnego z chorych, u których pobrano żyłę udową powierzchowną, nie zaobserwowano dużych obrzęków lub nasilonych objawów niewydolności żylnej kończyn. Wnioski. Leczenie operacyjne zakażeń protez naczyniowych jest wciąż bardzo trudne. Zastosowanie odpowiedniej metody terapii w poszczególnych przypadkach jest podstawą uzyskania dobrego wyniku. Żyła udowa powierzchowna może stanowić doskonały materiał zastępujący zakażoną protezę, zwłaszcza w przypadkach, w których wykonanie pomostu pozaanatomicznego jest niemożliwe.Background. The objective of this paper is to evaluate results of therapy of infected vascular prostheses with replacement of the prosthetic material with autologous superficial femoral vein. Material and methods. Between 2001 and 2003, 1580 vascular surgeries were performed in Department of Vascular Surgery. In 14 cases, indications of infection of the vascular prosthesis were seen. In 6 patients, venous material (superficial femoral vein — SFV) was used to re-establish circulation in the affected leg. SFV was used in the treatment of infections of aorto-bi-femoral bypasses (4 cases), aorto-femoral (1) and axillofemoral (1). In the last case, a desobliterated superficial artery was used (group I). In all the above cases, a new by-pass was run through the tunnel left after the removal of the infected prosthesis. In 8 cases, an extra-anatomical by-pass was inserted (group II). In 6 cases, axillo-bi-femoral by-pass was performed and 2 patients received axillo-popliteal bypasses. In every patient reconstructive procedure, regenerating flow in the affected limb, was preceded by partial or total excision of the infected prosthesis (during the same surgery). Results. Group I (n = 6) Group II (n = 8) Observation (months) 4–18 (average 11,4) 2–24 (average14,5) Mortality 1 (16,6%) 2 (25%) Amputations 0 1 Resurgeries 2 1 None of the patients in whom we performed SFV harvest presented with major edema or venous insufficiency. Conclusion. Treatment of vascular prosthesis infection is still a complicated therapeutic problem. Application of the correct treatment methods for each case is the key to therapeutic success. SVF may be an excellent replacement material, especially in cases where placement of an extra-anatomic bypass is impossible

Effect of the relative position of the face milling tooltowards the workpiece on machined surfaceroughness and milling dynamics

In face milling one of the most important parameters of the process quality is the roughness of the machined surface. In many articles, the influence of cutting regimes on the roughness and cutting forces of face milling is considered. However, during flat face milling with the milling width B lower than the cutter's diameter D, the influence of such an important parameter as the relative position of the face mill towards the workpiece and the milling kinematics (Up or Down milling) on the cutting force components and the roughness of the machined surface has not been sufficiently studied. At the same time, the values of the cutting force components can vary significantly depending on the relative position of the face mill towards the workpiece, and thus have a different effect on the power expended on the milling process. Having studied this influence, it is possible to formulate useful recommendations for a technologist who creates a technological process using face milling operations. It is possible to choose such a relative position of the face mill and workpiece that will provide the smallest value of the surface roughness obtained by face milling. This paper shows the influence of the relative position of the face mill towards the workpiece and milling kinematics on the components of the cutting forces, the acceleration of the machine spindle in the process of face milling (considering the rotation of the mill for a full revolution), and on the surface roughness obtained by face milling. Practical recommendations on the assignment of the relative position of the face mill towards the workpiece and the milling kinematics are given95sem informaçãosem informaçã

Carotid endarteriectomy in patients with contralateral internal carotid artery occlusion - early postoperative results

Wstęp. Pacjenci z hemodynamicznie istotnym zwężeniem tętnicy szyjnej wewnętrznej i zamknięciem przeciwstronnej tętnicy szyjnej wewnętrznej są grupą zwiększonego ryzyka wystąpienia pełnoobjawowego udaru niedokrwiennego mózgu. Dane z piśmiennictwa wskazują na konieczność wczesnego wdrożenia u tych chorych leczenia chirurgicznego. Endarteriektomia tętnicy szyjnej wykonywana w znieczuleniu miejscowym umożliwia stałe monitorowanie stanu neurologicznego pacjenta i pozwala na selektywne stosowanie czasowego przepływu wewnętrznego. Celem niniejszej pracy była ocena wyników wczesnych wspomnianych operacji i częstości stosowania czasowego przepływu wewnętrznego.Materiał i metody. Badano wyniki 323 zabiegów endarteriektomii szyjnej wykonanych u 290 chorych w latach 2002-2003 w Klinice Kardiochirurgii AMG. W 1 grupie znalazło się 49 operacji u chorych ze zwężeniem tętnicy szyjnej wewnętrznej powyżej 70% i zamknięciem przeciwstronnej tętnicy szyjnej wewnętrznej. W grupie 2 było 274 operacji przeprowadzonych u chorych ze zwężeniem tętnicy szyjnej wewnętrznej bez przeciwstronnej niedrożności. W 1 grupie stwierdzono znamiennie częściej występujące objawy neurologiczne (p > 0,01) oraz znamiennie częściej występujące zmiany niedokrwienne w tomografii komputerowej (CT) mózgowia (p > 0,001). Wyniki. W grupie 1 w obserwacji wczesnej stwierdzono 2 udary niedokrwienne mózgu (4,1%), natomiast w grupie 2 udar niedokrwienny wystąpił u 4 chorych (1,5%). W grupie 1 nie odnotowano zgonu, w grupie 2 śmiertelność wyniosła 1,8% (5 chorych). W grupie 1 znamiennie częściej stosowano czasowy przepływ wewnętrzny (p > 0,001) (16,3% vs. 2,2% w grupie 2). Wnioski. Obecność przeciwstronnego zamknięcia tętnicy szyjnej wewnętrznej wymagała częstszego stosowania czasowego przepływu wewnętrznego w trakcie endarteriektomii szyjnej. Częstość powikłań wczesnych była porównywalna w obu badanych grupach.Background. Patients with occlusion of internal carotid artery (ICA) and stenosis of internal carotid artery on the contralateral side are a high risk group for brain stroke. Literature data provide for early operative treatment in this group. Carotid endarteriectomy under local anaesthesia allows for continuous neurological state monitoring and allows a decrease in intraluminal shunt use. The objective of this study was to evaluate the early results of surgical treatment in this group and to evaluate intraluminal shut use rate. Material and methods. 323 procedures of carotid endarteriectomy were performed in the Department of Cardiac Surgery during the years 2002-2003. The patients were divided into two groups - group I (49 cases) of patients with occlusion of ICA and ≥ 70% stenosis of contralateral ICA, and group II (274 cases) of ≥ 70% ICA stenosis without contralateral occlusion. Group I had significantly more common preoperative neurological incidents and significantly more common ischemic changes in brain CT (p > 0.001). Results. In group I there were 2 brain infarcts in early observation (4.1%), while in group II 4 neurological incidents were noted (1.5%). No patient died in group I, while 5 patients died in early observation in group II giving mortality of 1.8%. In group I intraluminal shunt was used significantly more commonly (16.3% vs. 2.2%). Conclusions. The rates of neurological complications were comparable in both groups. Intraluminal shunting was used more commonly in the group with contralateral internal carotid artery occlusion

Current advances in~information quantum technologies - critical issues

This article reviews chosen topics related to the development of Information Quantum Technologies in the major areas of measurements, communications, and computing. These fields start to build their ecosystems which in the future will probably coalesce into a homogeneous quantum information layer consisting of such interconnected components as quantum internet, full size quantum computers with efficient error corrections and ultrasensitive quantum metrology nodes stationary and mobile. Today, however, the skepticism expressing many doubts about the realizability of this optimistic view fights with a cheap optimism pouring out of some popular press releases. Where is the truth? Financing of the IQT by key players in research, development and markets substantially strengthens the optimistic side. Keeping the bright side with some reservations, we concentrate on showing the FAST pace of IQT developments in such areas as biological sciences, quantum evolutionary computations, quantum internet and some of its components

Current advances in~information quantum technologies - critical issues

This article reviews chosen topics related to the development of Information Quantum Technologies in the major areas of measurements, communications, and computing. These fields start to build their ecosystems which in the future will probably coalesce into a homogeneous quantum information layer consisting of such interconnected components as quantum internet, full size quantum computers with efficient error corrections and ultrasensitive quantum metrology nodes stationary and mobile. Today, however, the skepticism expressing many doubts about the realizability of this optimistic view fights with a cheap optimism pouring out of some popular press releases. Where is the truth? Financing of the IQT by key players in research, development and markets substantially strengthens the optimistic side. Keeping the bright side with some reservations, we concentrate on showing the FAST pace of IQT developments in such areas as biological sciences, quantum evolutionary computations, quantum internet and some of its components