The weight of gas formed by Li-ion cell components heated to 400°C was studied by DSC. Electrolyte released the most gas – over 70% of its original weight during the heat treatment, while fully charged cathode and anode released gas at 4.6% and 3.9% of their original weight, respectively. Thus, the weight of gas formed during heat treatment by various solvents, LiPF6, and electrolytes containing various solvents or lithium salts was studied. Solvent thermal stability was the key to reducing the gas formation of electrolyte at elevated temperature. Electrolyte containing g-butyrolactone (GBL) solvent delayed the venting of Li-ion cells by approximately 50 °C compared with conventional electrolyte containing carbonate solvents during a hot box test. Cell venting was observed to be due to gas pressure from electrolyte decomposition in the cell.

The purpose of this study was to demonstrate that a proprietary surfactant polymer (SP) coating does not adversely affect the hemodynamic performance of cardiopulmonary bypass (CPB) or gas exchange in oxygenators. The new coating was applied to a CPB circuit including cannulae, reservoir, oxygenator, and blood pump implanted into 12 pigs, divided into groups with either coated or noncoated pumps. CPB flow was maintained at a fixed level of approximately 2.4 L/min for 6 hours with full heparinization. Hemodynamic data and pump performance were recorded every hour, and blood samples were taken every 2 hours. After sacrifice, the CPB circuit and major organs were macroscopically examined. There was no significant difference in the oxygen transfer rate between the two groups. The coating did not adversely affect oxygenator inlet or outlet pressures. There was no significant difference between the two groups in microthrombi seen in the oxygenators. No thromboemboli were noted in the major organs on gross or histologic examination. In conclusion, this new SP coating did not decrease gas exchange performance, and its biocompatibility evaluations revealed no differences between coated and noncoated groups under aggressive heparin use.

not Available.

Electrochemical studies of three types of CF x (F – fiber based, C – petroleum coke based, G – graphite based) have demonstrated different electrochemical performances in previous work, with fiber based CF x delivering superior performance over those based on petroleum coke and graphite. 13C and 19F MAS (magic angle spinning) NMR techniques are employed to identify the atomic/molecular structural factors that might account for differences in electrochemical performance among the different types of CF x . Small quantitative variations of covalent CF and LiF are noted as a function of discharge and sp 3 bonded carbons are detected in discharged F type of CF x .

The goals of this study were to investigate the fatigue limits of two Pd-Ag alloys (Ivoclar Vivadent) with differing mechanical properties and varying proportions of secondary alloying elements, examine the effect of casting porosity on fatigue behavior, and determine the effect of casting size on microstructures and Vickers hardness. The alloys selected were: IPS d.SIGN 59 (59.2Pd-27.9Ag-8.2Sn-2.7In-1.3Zn); and IS 64 (59.9Pd-26.0Ag-7.0Sn-2.8Au-1.8 Ga-1.5In-1.0Pt). Tension test bars, heat-treated to simulate dental porcelain application, were subjected to cyclic loading at 10 Hz, with R-ratio of -1 for amplitudes of compressive and tensile stress. Two replicate specimens were tested at each stress amplitude. Fracture surfaces were examined with a scanning electron microscope (SEM). Sectioned fatigue specimens and additional cast specimens simulating copings for a maxillary central incisor restoration were also examined with the SEM, and Vickers hardness was measured using 1 kg load. Casting porosity was evaluated in sectioned fatigue fracture specimens, using an image analysis program. The fatigue limit (2 × 10(6) loading cycles) of IS 64 was approximately 0.20 of its 0.2% yield strength, while the fatigue limit of d.SIGN 59 was approximately 0.25 of its 0.2% yield strength. These relatively low ratios of fatigue limit to 0.2% yield strength are similar to those found previously for high-palladium dental alloys, and are attributed to their complex microstructures and casting porosity. Complex fatigue fracture surfaces with striations were observed for both alloys. Substantial further decrease in the number of cycles for fatigue failure only occurred when the pore size and volume percentage became excessive. While the heat-treated alloys had equiaxed grains with precipitates, the microstructural homogenization resulting from simulated porcelain firing differed considerably for the coping and fatigue test specimens; the latter specimens had significantly higher values of Vickers hardness.

Three types of fluorinated carbon, all in their original form and upon sequential chemical lithiations via -butyllithium, were investigated by and solid-state NMR methods. The three starting materials [where (nominally)] were fiber based, graphite based, and petroleum coke based. The aim of the current study was to identify, at the atomic/molecular structural level, factors that might account for differences in electrochemical performance among the different kinds of . Differences were noted in the covalent F character among the starting compounds and in the details of LiF production among the lithiated samples.

The lithium/iodine-polyvinylpyridine (PVP) battery has been in clinical use as a power source for pacemakers for 35 years. Since 1972, literally millions of lithium/iodine cells have seen clinical use, providing health-giving and life-saving therapy to patients throughout the world. Indeed, the battery has compiled an excellent record of reliability and safety. The cell reaction is the simple combination of lithium and iodine to form lithium iodide, but the chemistry of the cathode material is interesting and complicated.

Magnetic Resonance Imaging (MRI) has become one of medicine's most important diagnostic tools. However, due to patient safety concerns, MRI is contraindicated by both device and MRI equipment manufacturers for patients with active implanted medical devices (AIMDs). The primary concern is overheating of implanted leadwires due to currents induced from the powerful RF fields of the MRI scanner. In pacemaker patients, heating of myocardial tissue has caused increase in pacemaker capture threshold and in some cases complete loss of capture (inability to pace). Permanent damage to an implantable cardioverter defibrillator and at least one patient death and another with severe burns along the wires of deep brain electrodes have also been reported. The authors, with pacemaker leadwires placed in a "worse case" MRI scan condition, have measured distal tip leadwire temperatures of up to 57 degrees C (more than sufficient to cause tissue damage). Another risk is localized myocardial ablation which could result in changes in the action potential vector during atrial/ventricular contraction. However, in contrast to reports of problems, there have been several recent anecdotal reports of MRI scans being safely performed on non-pacemaker dependent patients under highly controlled conditions. Proper diagnosis, treatment and management of a number of life threatening diseases such as cancer, neurological and brain disorders are made possible by MRI. Accordingly, the physician, with informed patient consent, must sometimes ignore the legal contraindications, weigh the risk factors, and go ahead and perform an MRI on an AIMD patient. This paper quantifies the attendant risks of performing MRI on AIMD patients and discusses means of mitigating certain hazards such as leadwire overheating including the performance a new leadwire distal tip resonant bandstop filter chip (MRI Chip) which presents a high impedance at the MRI pulsed RF frequency.

There are conflicting data regarding the clinical benefits of device-based remote monitoring (RM). We sought to assess the effect of device-based RM on long-term clinical outcomes in recipients of implantable cardioverter-defibrillators (ICDs).We assessed the incidence of adverse cardiac events, overall mortality and device therapy efficacy and safety in a propensity score-matched cohort of patients under RM compared to patients under conventional follow-up. Data on hospitalizations, mortality and cause of death were systematically assessed using a nationwide healthcare platform. The primary outcome was time to a composite outcome of first hospital admission for heart failure or cardiovascular death.Of a total of 923 implantable device recipients, 164 matched patients were identified (84 under RM, 84 under conventional follow-up). The mean follow-up was 44 months (range 1-123). There were no significant differences regarding baseline characteristics in the matched cohorts. Patients under RM had a significantly lower incidence of the primary outcome (hazard ratio [HR] 0.42, confidence interval [CI] 0.20-0.88, p=0.022); there was a non-significant trend towards lower overall mortality (HR 0.53, CI 0.27-1.04, p=0.066). No significant differences between cohorts were found regarding appropriate therapies (RM vs. conventional follow-up, 8.1 vs. 8.2%, p=NS) or inappropriate therapies (6.8 vs. 5.0%, p=NS).In a propensity score-matched cohort of ICD recipients with long-term follow-up, RM was associated with a lower rate of a combined endpoint of hospital admission for heart failure or cardiovascular death.Existem dados contraditórios acerca dos benefícios clínicos da monitorização remota (MR). Os autores procuraram aferir o efeito da MR de dispositivos cardíacos implantáveis em eventos clínicos a longo prazo.Os autores avaliaram a incidência de eventos cardíacos adversos, mortalidade global, e a eficácia e segurança das terapêuticas entregues pelo dispositivo numa amostra de pacientes portadores de cardioversor-desfibrilhador implantável (CDI) após emparelhamento por propensity score, comparando doentes sob MR com doentes em seguimento convencional. Dados relativos a hospitalizações, mortalidade e causa de morte foram sistematicamente avaliados com recurso à Plataforma de Dados de Saúde. A análise primária consistiu no tempo até um evento composto de internamento por insuficiência cardíaca (IC) ou morte cardiovascular.Num total de 923 portadores de dispositivos cardíacos, identificámos 164 pacientes emparelhados (84 sob MR, 84 sob seguimento convencional. O tempo médio de seguimento foi 44 meses (entre 1-123 meses). Não se observaram diferenças significativas nas características basais entre os dois grupos após emparelhamento por propensity score. Doentes sob MR tiveram uma incidência significativamente menor do evento composto de internamento por IC ou morte de causa cardiovascular (hazard ratio [HR] 0,42; intervalo de confiança [IC] 0,20-0,88; p=0,022); houve uma tendência não estatisticamente significativa para uma menor mortalidade global (HR 0,53; IC 0,27-1,04; p=0,066). Não se observaram diferenças entre grupos relativamente a terapêuticas apropriadas (MR versus seguimento convencional; 8,1 versus 8,2%, p=NS) ou terapêuticas inapropriadas (6,8 versus 5,0%, p=NS).Numa amostra emparelhada por propensity score de portadores de CDI, a MR associou-se a uma menor incidência de um evento composto de internamento por IC ou morte cardiovascular a longo prazo.

The system has been successfully used in implantable batteries to power medical devices for humans. Amassed data is analyzed to show that the behavior is dominated by the open-circuit potential and Tafel kinetics. Data from several discharge load resistances can be collapsed onto a single curve on this basis. At the low rates of interest, transport limitations can be neglected. Data for open-circuit relaxation show that the potential is a straight line when plotted against the logarithm of time. This is in harmony with the dominance of Tafel kinetics.