Top PDF New concepts for use in low-energy cardiac defibrillation

New concepts for use in low-energy cardiac defibrillation

New concepts for use in low-energy cardiac defibrillation

We next considered a single scroll wave in a rectangular box system, similar to that in [23]. Two plane electrodes were situated at the front and back of the box. This is similar to the point electrodes used for standard defibrillation except that it produces an electric field that is more spatially uniform in strength than is possible with point electrodes. Figure 9 shows an example of successful termination of a scroll wave in a 3D rectangular system using plane electrodes. In the simulation, an electric field with strength of 2.2V/cm was applied across the system, parallel to the I-shaped filament (white dashed line), causing the back wall to become depolarized. The initial filament became C-shaped, connecting to the front wall and the top of the box. The scroll wave continued to rotate around the now C-shaped filament shrinking until it disappeared. We also created a cylindrical system using the same method of eliminating gap junctions as was used to create the hemispherical shell system. Electric fields with different strengths were applied to the system to determine the minimum strength for which termination was successful. The fields were applied at six different times, each one-fifth of the waves rotational period apart, to test whether success depended on the wave’s phase. Here, the scroll wave was terminated for an electric field strength of 1.0753V/cm but failed to terminate for a strength of 0.9677V/cm for all six stimulus times. Figure 10 describes the possible outcomes after the application of a single electric field pulse. In the top row, a field strength of 0.9677V/cm was applied. After two rotations, the filament returned to I-shape and persisted. In the bottom row, a field strength of 1.0753V/cm was applied. Here, the filament remained C-shaped after two rotations. This filament continued to shrink until it disappeared.
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New Concepts in the Management of Neonatal Jaundice: Use of Enzyme Induction and Phototherapy

New Concepts in the Management of Neonatal Jaundice: Use of Enzyme Induction and Phototherapy

More than 200 drugs, insecticides, carcinogens and other chemicals are known to stimulate the activity of enzymes in the liver. Enzymes can be stimulated by different t[r]

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Information Literacy and the workplace: new concepts, new perspectives?

Information Literacy and the workplace: new concepts, new perspectives?

How is Information Literacy to be reconceptualised for the workplace? Through what recasting of its parameters are librarians and library managers to better understand and so effectively support workplace professionals, and the students studying for those professions, in their information needs and use? How can their Information Literacy be developed in a way that is meaningful and appropriate for them? Perhaps the question is one of evidence as much as conception: how can professions, many of which are especially focused on, and dependent on,

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New Concepts in Pacemaker Syndrome

New Concepts in Pacemaker Syndrome

Several ongoing trials are looking at the benefits of reduction in RV pacing in the DDDR mode. The first is the Danish Multicenter Randomized Study of Atrial Inhibited Versus Dual- Chamber Pacing in Sick Sinus Syndrome (DANPACE). This trial is comparing AAI pacing and DDDR pacing with a short A-V delay. The second is the Search A-V Extension for Promoting Atrioventricular Conduction (SAVE-PACE) study. This study will evaluate the use of search hysteresis, a pacemaker feature that allows the extension of the A-V delay to reduce right ventricular pacing. The study investigators hypothesize that the reduction in RV pacing will lead to a reduction in left ventricular remodeling and AF.
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Low-Bias Extraction of Domain-Specific Concepts

Low-Bias Extraction of Domain-Specific Concepts

approaches to concept extraction, namely knowledge-rich and low-bias approaches. Knowledge-rich approaches use knowledge about the structure of the data sources to pro- cess. Especially, text-based approaches include knowledge such as phrase structure, lemmas and part-of-speech to ex- tract nouns or noun phrases as units to process [3]. The category of knowledge-rich approaches also includes su- pervised machine learning techniques and clustering tech- niques based on knowledge-rich features [11]. Knowledge- rich approaches are subject to limitations regarding their portability to other languages and domains because of the background knowledge they necessitate. Low-bias (also called knowledge-lean [20]) approaches try to remedy these problems by not using a-priori knowledge on the lan- guage to process. Rather, they make use of statistical fea- tures to extract the features of the terms which compose a concept. Clustering techniques based on low-bias features are the main constituent of this category of approaches.
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Recircaeration – a new low energy method of preserving cereal grains

Recircaeration – a new low energy method of preserving cereal grains

It is clear that recircaeration is more effective than ambient aeration under the climatic conditions considered. This is because the stored grains act as a desiccant and this supports the first hypothesis posited in this paper. The second hypothesis is that solar energy combined with aeration dries out the upper layer of grain and this enables grains to be cooled to lower temperatures. Although the research reported in this paper indicates that the upper layer of grain does indeed dry as a result of solar energy it is not possible to state for certain that this phenomenon offers a net benefit. Further research on the effects of grain moisture content, air flow rates and emissivities needs to be carried out. It is also important that the findings of this paper be validated, at least qualitatively.
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Wind Turbine Concepts for Energy Efficiency in Buildings

Wind Turbine Concepts for Energy Efficiency in Buildings

112 Wind as a source of energy has become very popular and is continuously growing since last decade. The technologies and research work regarding wind turbines and wind energy generation are getting developed in fast rate. Many programs are started which promote the use of wind energy for energy generation. Incentives are provided for that. By this the energy market of wind has also increased levels. Apart from other sources the utility side generates electrical energy using wind energy and supply this electrical energy to other utilities or consumers. But the level and popularity of wind energy has risen so much that the wind energy is used by consumer side also for power generation. Small scale wind turbine technologies[2]-[8] are used for electricity generation at small level. Consumers can install wind turbine based plants on the rooftop of their buildings, homes or in front of the homes, buildings in open area etc. Simply, this can be said that the contribution of wind energy to the overall energy supply is very significant.
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Toward Inductive Learning of Energy-Related Concepts

Toward Inductive Learning of Energy-Related Concepts

Abstract—Energy is an important topic in science and engineering. Yet, clear definitions of this concept are difficult to come by and, as a result, students often develop a limited understanding of energy and energy-related concepts. This is exacerbated by traditional, deductive means of teaching. In this paper, the authors report on an attempt at introducing an inductive approach to the teaching and learning of energy-related concepts, specifically conservation of energy. The approach was attempted among a select group of school students using inductive means, and was adapted from an article in the literature that addressed flight energy management training for pilots. The aim of the paper is to describe the intervention, which sought to foster a deeper understanding of energy flows within a system and place the school students in good stead for their subsequent design of an ultra-energy efficient hydrogen-powered vehicle. This is done in order to demonstrate how inductive learning can be enacted in an engineering curriculum. However, the intervention was implemented with a small sample of students and, as such, further attention needs to be given to how such an inductive learning approach can be incorporated into formal curricula at both school and university levels, with a diverse range of students, and with diverse topics.
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Construction of Energy Optimal Smooth Monophasic Defibrillation Pulse Waveforms Using Cardiomyocyte Membrane Model

Construction of Energy Optimal Smooth Monophasic Defibrillation Pulse Waveforms Using Cardiomyocyte Membrane Model

. The segments of the piecewise linear function describing the energy-op- timal pulse waveforms were constructed by using energy-optimal trapezoidal segments (ramp), during which the transmembrane potential increases from the present level to the next, with the initial signal level of a subsequent segment being equal to the final signal level of the previous one. These segments are checked to determine the time required for the energy ratio to have a minimum value during the transition of the transmembrane potential from one predetermined level to another. Since exposure value in the model is not the current value, and its den- sity, the dimension expressed in the energy ratio in the μA 2 ∙ms/cm 4
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Relationship between canine transthoracic impedance and defibrillation threshold  Evidence for current based defibrillation

Relationship between canine transthoracic impedance and defibrillation threshold Evidence for current based defibrillation

The electrical parameter used to define defibrillation strength is energy. Peak current, however, may more accurately reflect the field quantities (i.e., electric field strength and current density) that mediate defibrillation and therefore should be a better clinical descriptor of threshold than energy. Though transthoracic impedance is a major determinant of energy- based threshold and is sensitive to operator-dependent changes in impedance (electrode- subject interface), an ideal threshold descriptor should be invariant with respect to these changes in impedance. We therefore compared the relative invariance of energy- and current-based thresholds when transthoracic impedance was altered by one of two
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Chest compressions before defibrillation for out-of-hospital cardiac arrest: A meta-analysis of randomized controlled clinical trials

Chest compressions before defibrillation for out-of-hospital cardiac arrest: A meta-analysis of randomized controlled clinical trials

In 2002, Weisfeldt et al. proposed a three-phase time- sensitive model for treatment of sudden cardiac arrest: the electrical phase (early phase during the first around 0-4 min where immediate defibrillation may be optimal, the circulatory phase (4-10 min) where predefibrillation chest compressions could be meaningful, and the meta- bolic phase (> 10 min), where survival rates are poor in general [39]. The authors stated in their editorial that “phase-specific research is needed to extend knowledge of the importance of time on resuscitation, such as test- ing early defibrillation and public access defibrillation programs during the electrical phase and testing chest compression and vasoconstrictors first during the circu- latory phase.” [39]. Our findings support the view of Weisfeld et al. as illustrated in Figure 4 and as shown in the subgroup analyses of patients with longer versus those with shorter response intervals.
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Out of hospital cardiac arrest outside home in Sweden, change in characteristics, outcome and availability for public access defibrillation

Out of hospital cardiac arrest outside home in Sweden, change in characteristics, outcome and availability for public access defibrillation

We found a trend towards a decreasing median age, with a drop from 68 to 64 years during the study period. This in not line with what others have found. From a study conducted in Seattle between 1977 and 2001, Rea and colleagues reported an increase in the mean age among EMS-treated cardiac arrests from 64 to 68 years of age [10]. It is only possible to speculate that, among the victims of sudden death included in our study, there is a higher per- centage of OHCAs with undiagnosed cardiac disease, physically capable and healthy enough to be out in public places. These cases perhaps conform to a higher extent with "hearts too good to die" [11]. On the other hand, Kuisma and co-workers found that OHCA of non-cardiac origin is more likely to take place among the younger members of the population and is secondary to pulmo- nary disease, internal bleeding, suicide, trauma and drug intoxication [12]. These findings could suggest that the drop in the mean age of victims of OHCAs in our survey could to some extent be explained by the concurrent increase in OHCAs of non-cardiac aetiology that was also observed. The data relating to the aetiology of the OHCAs in our study must be interpreted carefully, as they are based on the clinical judgement of the EMS personnel and not on autopsies or clinical investigations.
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Hemodynamic effects of ventricular defibrillation

Hemodynamic effects of ventricular defibrillation

Hemodynamic responses to ventricular defibrillation were studied in anesthetized dogs. Observations were made on arterial, right atrial and left ventricular end-diastolic pressures, on cardiac output (dye dilution), heart rate, and right atrial electrocardiogram. Ventricular fibrillation was induced electrically with a bipolar electrode catheter placed in the right ventricle. Fibrillation was maintained for 15 or 30 sec and terminated with a 400 w sec capacitor discharge across the thoracic cage.

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New Energy Absorbing Materials and their Use in Personal Protective Equipment

New Energy Absorbing Materials and their Use in Personal Protective Equipment

Di Landro et. al. [15] concluded that using functionally graded materials could be an alternative for optimization of helmet’s liner in order to increase the energy absorption. In another experimental study, Gupta [209] showed that a functionally graded structure could increase the energy absorption up to 500% comparing to a structure with uniform material properties through the thickness. Moreover, Cui et. al. [16] showed that the protection capability of helmets could be improved by means of using liners with varying mechanical properties through the thickness. These studies were dedicated to functionally graded foams while manufacturing helmet liners made of such foams is still in concept phase [16]. However, thanks to the advances in field of additive manufacturing, complex lattice structures can be manufactured nowadays. Therefore, here the feasibility of using a hierarchical lattice structure has been studied in order to realize how such a structure could be used in order to improve the energy absorption capability and protection level of the helmets. A hierarchical lattice structure has varying cell sizes at different rows as shown in Figure 6-11 and each cell size provides particular mechanical properties, therefore, the entire structure has varying mechanical properties through the thickness. As it is shown in Figure 8-29 a material like EPS crushes uniformly through thickness unlikely, a lattice structure with varying mechanical properties through the thickness starts to crush from the weakest layer and all layers would crush one after the other from the weakest layer to the strongest one. Such a structure provides a varying yield stress (𝜎 𝑦 ) through the thickness,
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Concepts for a sustainable energy supply of large cities

Concepts for a sustainable energy supply of large cities

Energy Concept: Approach Energy balance of the city / district Target years and boundary conditions Determination of the energy system, status quo Discussion and Elaboration [r]

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An Optimized Low-Noise Low-Power Preamplifier for Cardiac Implants 

An Optimized Low-Noise Low-Power Preamplifier for Cardiac Implants 

Biosignals like EEG, ECG, EMG, EOG are weak signals with an input amplitude typically ranging from 0.5µV to 5mV [5,6] and are highly susceptible to noise and power line interference at 50Hz to 60Hz. Nowadays there is a demand for a low noise, low power bio acquisition system so as to avoid bulky connectivity and reduce patients’ mobility and discomfort [7]. A Preamplifier is one of the important components of the analog front end as it determines the SNR of the entire biomedical signal acquisition system and is required for reliable monitoring of the physiological signal [8]. These weak biosignals need to be amplified before being compatible for processing by the other components of the implant for measurement and testing purposes [9].
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Effects of Low-cost Offsets on Energy Investment -New Perspectives on REDD-

Effects of Low-cost Offsets on Energy Investment -New Perspectives on REDD-

In addition, there is also a value to preserving forests, as deforestation is an irreversibility in itself and destroys the value of flexibility that REDD options imply. In other words, keeping the REDD potential open has an option value of its own account. Finally, but related to the previous point, we want to address the question of the timing of adopting REDD and the design of the underlying mechanisms. To date, there are still many unresolved issues (REDD mechanisms, climate sensitivity, REDD potential, etc) and also political difficulties (commitment of different countries) with respect to implementation. However, our suggestions point to the usefulness of going ahead with REDD already at this stage, even if many issues are not solved yet and many technicalities remain unclear at the moment. The reason for this is that the exertion of the REDD options will have to be decided upon in the future and not now, so the payment in terms of the option price has to made today, but it is low compared to the strike price and the price of CO 2 permits. So, even if some problems can only be resolved in the future, it
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The role of triacylglycerol in cardiac energy provision

The role of triacylglycerol in cardiac energy provision

perfused rat hearts, and decreased (halved) their glucose utilisation [12]. Interestingly, whilst oxygen is essential for metabolism, oxygen availability may not dictate uptake of CM-TAG. Indeed, high rates of TAG emulsion uptake (and LPL activity) in mouse heart in vivo were not affected by chronic intermittent hypoxia [13] suggesting a potential mismatch between CM-TAG uptake and utilisation. Mouse hearts perfused with rat CM (0.4mM) utilised large amounts of CM-TAG [14] and achieved high degrees of cardiac power; equal amounts of CM-TAG assimilated were oxidised and esterified into tissue lipids (mainly TAG) and CM-TAG oxidation rates were similar to NEFA (0.4mM palmitate) oxidation, though proportionately more NEFA was oxidised than esterified. Furthermore, NEFA did not inhibit CM-TAG utilisation by the mouse heart [14]. Rat hearts perfused with rat CM utilised CM-TAG to about the same extent as NEFA when each were compared as sole lipid substrates [15, 16] and CM could maintain cardiac mechanical function; most (83%) of the CM-TAG assimilated was oxidised, the remainder was esterified mostly into cellular TAG [15, 16]. NEFA did inhibit CM-TAG utilisation when co-perfused, and this was entirely due to decreased CM-TAG oxidation, but CM did not suppress myocardial NEFA uptake and metabolism [16]. Together, these observations imply that NEFA-derived FA are more likely to be oxidised and CM-TAG-derived FAs more likely to be esterified [14] suggesting that there may be discrete partitioning between non-esterified and CM-TAG-derived FA. Mouse hearts clear CM-TAG (by lipolysis) more rapidly than they assimilate core (cholesteryl ester) lipid: about 5% of injected CM were recovered in hearts within 2 min, indicating rapid CM uptake by this tissue, but
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New Concepts of Equality of Educational Opportunity

New Concepts of Equality of Educational Opportunity

education is still no fairly implement in each county; 4) Disadvantaged and lower social class family were treated discriminated. The authority needs to deal with economics, teacher training, and family education. Here are some specific strategies for the new concepts: 1) enacting correspondent policy for inputting resources, subsidize for educational priority areas (EPA), special need, aboriginal (ethnical), grand-parenting, foreign spouse family, single parent family…etc. input the money to those people in need especially the target school districts with high concentrations. Give the target schools provisions intended to give greater flexibility in how they spent a portion of their allotments, evaluate the progress annually for exam the next year founding and check benchmark performances instead of inputting investment as in region should be invested as cases or certain groups; 2) lower teaching staffs change flow by topping up the allowance (housing, transportation, benefit…etc.), offering various teacher training program and providing new teaching staffs mentor instruction system, the training program could cover teach new teachers how to teach and be a professional teacher (pre-service training internship as a volunteer at schools, learning teaching knowledge, courses; in-service training of updated technology practice, new teaching methods or skills). The mentor system offers the help of the senior teacher who had got the better reputation on the teaching field could be new teacher’s role model and gives new teacher comments and suggestions; 3) offering free tutorial classes and mental counseling activity for students, universities could send students as interns to help those culturally deprived learners for the on line or off line tutorial classes, as well as the psychologist counseling programs, those disadvantaged students need both academic and mental support; 4) supporting lower social class family and enhancing family education, not only financial subsidy but also the teacher-parent communication and education by offering workshop and seminar of how guardian educate the child and communicate in both way between family and school.
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DOBUTAMINE USE IN CARDIAC PATIENTS

DOBUTAMINE USE IN CARDIAC PATIENTS

Clinical experience with dobutamine injection following myocardial infarctionhas been insufficient to establish the safety of the drug for this use. There is concern that any agent that increases contractile force and heart rate may increase the size of an infarction by intensifying ischemia, but it is not known whether dobutamine does so.

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