Sudden onset function

A sudden onset function will not likely be of much use for the ICD to discriminate AT from VT since both can initiate in this fashion. A ventricular morphology or width discriminator may help, again in the absence of BBA. Not all ATs conduct each beat to the ventricles, so this information ( P waves > R waves) in a dual chamber ICD event recording may allow the interpreter to help rule in the diagnosis of SVT. It should be noted that dual tachycardias, i.e. SVT and VT, can coexist in which the number of registered P waves is still greater then the number of registered R waves. 

Signs and Symptoms Sudden onset of fever, headache, vomiting and possibly abdominal pain, progressing to neck stiffness, mental confusion, motor disturbances, and difficulty with equilibrium. Survivors may suffer significant impairment of mental functions. 

The severity of drug-induced immune hemolytic anemia is usually a function of the rate of hemolysis. Hemolytic anemia caused by drugs via the hapten/adsorption and autoimmune mechanisms tend to be slower in onset and mild to moderate in severity. Conversely, hemolysis prompted via the neoantigen mechanism (innocent bystander) phenomenon may have a sudden onset, lead to severe hemolysis, and result in renal failure. The treatment of drug-induced immune hemolytic anemia includes the removal of the offending agent and supportive care. Glucocorticoids are usually unnecessary, and practitioners have questioned their efficacy. ... 

The CH emission accounts for 1% of the total observed emission and requires 12.76 eV of energy which compares to the 12.84 eV provided by two ArF laser photons. It is interesting to note that Metzger and Cook observed visible emission in the 300-600 nm region as a function of acetylene photolysis wavelength between 103 and 58 nm. Between 103 and 92 nm there is a sudden onset of visible fluorescence. This region corresponds very closely to the thermodynamic threshold for... 

An isolated case describes spontaneous orgasm with the combined use of bupropion and sertraline. Bupropion had been successfully used to treat SSRI-induced impaired sexual function, but after 6 weeks of combined therapy she experienced a sudden-onset, spontaneous orgasm this occurred again on rechallenge with bupropion. ... 

So how can the ICD differentiate sinus tachycardia from VT Most ICDs can be programmed in their VT zones with a discriminator commonly referred to as "sudden onset." This can be used to help limit delivery of therapy for sinus tachycardia. Sudden onset tries to take advantage of the fact that sinus tachycardia, as opposed to VT, typically does not initiate in a sudden fashion. Other SVTs, however, can typically initiate in a sudden manner. In any case, an ICD may rarely deliver therapy for sinus tachycardia simply by the fact that a sustained rate criteria has been met should such a function be programmed on (it is actually quite common for both a sudden onset and sustained duration feature to be programmed on simultaneously). 

Management Solution Consider a discriminator such as sudden onset that may decrease the likelihood of shocking for sinus tachycardia. A ventricular morphology discriminator might also be effective for this purpose (this ICD did not have that function). Also, a physician will sometimes prescribe medication with beta-adrenergic blocking activity in an attempt to prevent the native heart rate from reaching the VT zone. 

Fig. 13.21 shows another example of oscillatory burning of an RDX-AP composite propellant containing 0.40% A1 particles. The combustion pressure chosen for the burning was 4.5 MPa. The DC component trace indicates that the onset of the instability is 0.31 s after ignition, and that the instability lasts for 0.67 s. The pressure instability then suddenly ceases and the pressure returns to the designed pressure of 4.5 MPa. Close examination of the anomalous bandpass-filtered pressure traces reveals that the excited frequencies in the circular port are between 10 kHz and 30 kHz. The AC components below 10 kHz and above 30 kHz are not excited, as shown in Fig. 13.21. The frequency spectrum of the observed combustion instability is shown in Fig. 13.22. Here, the calculated frequency of the standing waves in the rocket motor is shown as a function of the inner diameter of the port and frequency. The sonic speed is assumed to be 1000 m s and I = 0.25 m. The most excited frequency is 25 kHz, followed by 18 kHz and 32 kHz. When the observed frequencies are compared with the calculated acoustic frequencies shown in Fig. 13.23, the dominant frequency is seen to be that of the first radial mode, with possible inclusion of the second and third tangential modes. The increased DC pressure between 0.31 s and 0.67 s is considered to be caused by a velocity-coupled oscillatory combustion. Such a velocity-coupled oscillation tends to induce erosive burning along the port surface. The maximum amplitude of the AC component pressure is 3.67 MPa between 20 kHz and 30 kHz. - ...

In the stepwise synthesis of peptides using cross-linked polystyrene supports, the rate of incorporation of a particular amino acid residue has been found to decrease with increasing chain length in a number of instances 41 -43). These occurrences have been attributed to steric hindrance at the various functional sites on the heterogeneous network. Sheppard investigated the origin of this steric hindrance and its sudden and unpredictable onset on the reactivity and physicochemical characteristics in the case of the cross-linked polystyrene-bound peptides 44). These studies suggested that the physicochemical incompatibility of the polystyrene matrix with the attached peptides is the factor responsible for the undesired influences of the solid support on the synthetic manipulations 44 45>. 

As noted, for both the lysozyme—saccharide complex and the purple membrane, the critical point for protonic percoladon is at the onset of function. These observations may apply to other situations, in which a new property emerges suddenly at a critical water content, and may lead to understanding of function in terms of the building up of a statistical network of water-assisted pathways encompassing the system. Statistical... 

We found the contraction of the f-wave functions to an atomic like character. This has an important consequense, because we see the onset of a cooperative effect, the orbital magnetic moment to spin conduction band electrons interaction and other correlations will generate an effective mass for the f-electrons which, in turn, will, by contraction of the f-wave function, enhance the atomic like character and then enhance the full process, hence the process will not be smooth or show linear behaviour the process will tend to present a sudden change of the f-electrons from a band character to an almost atomic like behaviour. This many-body effect is responsible for further scattering between the conduction electrons and the rare earth or actinide f electron states,... 

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