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- Ornato, J P, et al.
(författare)
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Future directions for resuscitation research. III. External cardiopulmonary resuscitation advanced life support.
- 1996
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Ingår i: Resuscitation. - 0300-9572 .- 1873-1570. ; 32:2, s. 139-58
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Tidskriftsartikel (refereegranskat)abstract
- This discussion about advanced cardiac life support (ACLS) reflects disappointment with the over 50% of out-of-hospital cardiopulmonary resuscitation (CPR) attempts that fail to achieve restoration of spontaneous circulation (ROSC). Hospital discharge rates are equally poor for in-hospital CPR attempts outside special care units. Early bystander CPR and early defibrillation (manual, semi-automatic or automatic) are the most effective methods for achieving ROSC from ventricular fibrillation (VF). Automated external defibrillation (AED), which is effective in the hands of first responders in the out-of-hospital setting, should also be used and evaluated in hospitals, inside and outside of special care units. The first countershock is most important. Biphasic waveforms seem to have advantages over monophasic ones. Tracheal intubation has obvious efficacy when the airway is threatened. Scientific documentation of specific types, doses, and timing of drug treatments (epinephrine, bicarbonate, lidocaine, bretylium) are weak. Clinical trials have failed so far to document anything statistically but a breakthrough effect. Interactions between catecholamines and buffers need further exploration. A major cause of unsuccessful attempts at ROSC is the underlying disease, which present ACLS guidelines do not consider adequately. Early thrombolysis and early coronary revascularization procedures should also be considered for selected victims of sudden cardiac death. Emergency cardiopulmonary bypass (CPB) could be a breakthrough measure, but cannot be initiated rapidly enough in the field due to technical limitations. Open-chest CPR by ambulance physicians deserves further trials. In searches for causes of VF, neurocardiology gives clues for new directions. Fibrillation and defibrillation thresholds are influenced by the peripheral sympathetic and parasympathetic nervous systems and impulses from the frontal cerebral cortex. CPR for cardiac arrest of the mother in advanced pregnancy requires modifications and outcome data. Until more recognizable critical factors for ROSC are identified, titrated sequencing of ACLS measures, based on physiologic rationale and sound judgement, rather than rigid standards, gives the best chance for achieving survival with good cerebral function.
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| 2. |
- Kiros, Yohannes, 1956-, et al.
(författare)
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Electrode R&D, stack design and performance of biomass-based alkaline fuel cell module
- 1999
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Ingår i: International journal of hydrogen energy. - : Pergamon Press. - 0360-3199 .- 1879-3487. ; 24, s. 549-564
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Tidskriftsartikel (refereegranskat)abstract
- Electrode formulations with di}erent materials and manufacturing techniques were tested electrochemically in order to assess their stability and activity in long!term operations. Cathode electrocatalysts such as CoTPP, Ca0.9La0.1MnO3 and Pt-Co alloys were incorporated in high surface area carbons and operated at a constant load of 100 mA cm-2 80C and an electrolyte concentration of 6M KOH. Similarly, anode catalysts with Pt-Pd bimetallic combinations were also tested and ascertained in half!cell measurements. Surface area measurements and Transmission Electron Microscopy (TEM) analyses were carried out both before and after the electrochemical test procedures. The electrodes were incorporated into a seven and two cell module design of the external and internal manifolding types and the experiences gained from these design principles are described, respectively. Furthermore, a biomass fed AFC module with all the system descriptions, steps, and a demonstration layout of producer gas to alkaline fuel cell are examined and discussed. Wood charcoal and agro-residues were used as feedstock and as a primary fuel. Power output of the different feedstock in a producer gas fed alkaline fuel cell has the shown potentiality and effciency to be applied as a stand alone power generator.
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| 3. |
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| 4. |
- Torabi, F., et al.
(författare)
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Coulometric determination of NAD+ and NADH in normal and cancer cells using LDH, RVC and a polymer mediator
- 1999
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Ingår i: Talanta. - 1873-3573. ; 50:4, s. 787-797
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Tidskriftsartikel (refereegranskat)abstract
- An electrochemical method for the measurement of NAD(+) and NADH in normal and cancer tissues using flow injection analysis (FIA) is reported. Reticulated vitreous carbon (RVC) electrodes with entrapped L-lactate dehydrogenase (LDH) and a new redox polymer containing covalently bound toluidine blue O (TBO) were employed for this purpose. Both NAD(+) and NADH were estimated coulometrically based on their reaction with LDH. The latter was immobilized on controlled pore glass (CPG) by cross-linking with glutaraldehyde and packed within the RVC. The concentrations of NAD(+) and NADH in the tissues, estimated using different electron mediators such as ferricyanide (FCN), meldola blue (MB) and TBO have also been compared. The effects of flow rate, pH, applied potential (versus Ag/AgCl reference) and adsorption of the mediators have also been investigated. Based bn the measurements of NAD(+) and NADH in normal and cancer tissues it has been concluded that the NADH concentration is lower, while the NAD(+) concentration is higher in cancer tissues. Amongst the electron mediators TBO was found to be a more stable mediator for such measurements. (C) 1999 Elsevier Science B.V. All rights reserved.
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