Bipolar unipolar

Through the use of psychopharmacotherapy, it thus appears that bipolar, unipolar, and atypical depressions are discrete entities. They are also separate from dysthymia, which may be the bridging condition to the anxiety disorders. 

Central electrophysiological measures are also partially supportive, in that evoked response and computer-assisted electroencephalogram (EEG) mapping indicate bipolar-unipolar differences, with right-sided abnormalities more common in bipolar patients. Further, P300 topographical differences have been reported between schizophrenic and psychotic manic patients (41). 

Nassir, G. S., Boiman, E., Goodwin, F. K. (2000). Insight and outcome in bipolar, unipolar, and anxiety disorders. Comprehensive Psychiatry, 41, 167-171. 

In an HBT the charge carriers from an emitter layer are transported across a thin base layer and coUected by a third layer called the coUector. A small base current is present which iacludes the carriers that did not successfully cross the base layer from the emitter to the coUector. The FET is a unipolar device making use of a single charge carrier in each device, either electrons or holes. The HBT is a bipolar device, using both electrons and holes in each device. The emitter and coUector layers are doped the same polarity n- or -type), with the base being the opposite polarity (p- or n-ty- e). An HBT with a n-ty e emitter is referred to as a n—p—n device ap—n—p device has a -type emitter. The n—p—n transistors are typicaUy faster and have been the focus of more research. For the sake of simplicity, the foUowing discussion wiU focus on n—p—n transistors. 

The bipolar membranes are used in a more or less conventional ED stack together with conventional unipolar membranes. Such a stack has many acid—alkah producing membranes between a single pair of end electrodes. The advantages of the process compared to direct electrolysis seem to be that because only end electrodes are required, the cost of the electrodes used in direct electrolysis is avoided, and the energy consumption at such electrodes is also avoided. 

Output power Bipolar or unipolar flux Input voltage Number of windings Winding configuration... 

Fig. 31.3. (a,b) Reproduction of distances D and angular distances 0 in a score plot (a = 1) or loading plot (p = 1) in the common factor-space (c,d) Unipolar axis through the representation of a row or column and through the origin 0 of space. Reproduction of the data X is obtained by perpendicular projection of the column- or row-pattern upon the unipolar axis (a + P = 1). (e,0 Bipolar axis through the representation of two rows or two columns. Reproduction of differences (contrasts) in the data X is obtained by perpendicular projection of the column- or row-pattern upon the bipolar axis (a + P = 1). 

Fig. 31.4. (a) Biplot in which the concentrations of an atmospheric trace element (Cl) are reconstructed by perpendicular projection upon a unipolar axis, (b) Biplot in which the differences (contrasts) between two atmospheric trace elements (Cl, Si) are reproduced by perpendicular projection upon a bipolar axis. 

Fig. 31.6. Biplot of chromatographic retention times in Table 31.2, after column-centering of the data. Two unipolar axes and one bipolar axis have been drawn through the representations of the methods DMSO and methylenedichloride (CH2CI2). The projections of three selected compounds are indicated by dashed lines. TTie values read off from the unipolar axes reproduce the retention times in the corresponding columns. The values on the bipolar axis reproduce the differences between retention times.

Finally, we have constmcted a bipolar axis through DMSO and methylenedichloride. By perpendicular projection of the centers of the circles upon this bipolar axis we obtain the differences in retention times obtained respectively with DMSO and with methylenedichloride. Using a similar reasoning as developed above for unipolar axes we can perform a substitution of eq. (31.42) in eq. (31.38) which leads to ... 

The distances between compounds in Fig. 31.7 are not notably affected by the transformation in comparison with the previous Fig. 31.6. This biplot allows more easily to perceive the correlations between measurements. Three clusters are now put in evidence, namely (1) DMSO and DMF, (2) ethanol and propanol, (3) octanol, dioxane, THF and methylenedichloride. The line segments drawn from the origin have been added to emphasize these groupings. Unipolar axes could have been defined here in the same way as in Fig. 31.6. Bipolar axes on the column-standardized biplot, however, cannot be interpreted directly in terms of the original data in X. 

The analysis of Table 31.2 by CFA is shown in Fig. 31.11. As can be seen, the result is very similar to that obtained by log double-centering in Figs. 31.9 and 31.10. The first latent variable expresses a contrast between NO2 substituted chalcones and the others. The second latent variable seems to be related to the electronic properties of the substituents. The contributions of the two latent variables to the total inertia is 96%. The double-closed biplot of Fig. 31.11 does not allow a direct interpretation of unipolar and bipolar axes in terms of the original data X. The other rules of interpretation are similar to those of the log double-centered biplot in the previous subsection. Compounds and methods that seem to have moved away from the center and in the same directions possess a positive interaction (attraction). Those that moved in opposite directions show a negative interaction (repulsion). 

Unipolar and bipolar axes have been discussed in Section 31.2. Briefly, a unipolar axis is defined by the origin and the representation of a row or column. A bipolar axis is drawn through the representations of two rows or through the representations of two columns. Projections upon unipolar axes reproduce the values in the transformed data table. Projections upon bipolar axes reproduce the contrasts (i.e. differences) between values in the data table. 

These data show that for three psychotic disorders (schizophrenia, bipolar disorder and unipolar depression) the genetic contribution is over 50% but for reactive depression (in response to a traumatic life event ) and tuberculosis, an infectious disease caused by a species of Mycobacterium, environmental factors account for over 90% of the variance. 

Turning to the pharmacotherapy for mania, for decades lithium was the only effective drug treatment. More recently, a number of antiepileptic drugs including carba maze pine, lamotrigine and valproate have been shown to also act as mood stabilisers and are becoming established for the treatment and prophylaxis of both unipolar mania and bipolar manic depressive disorders. 

In clinical psychiatric terms, the affective disorders can be subdivided into unipolar and bipolar disorders. Unipolar depression is also known as psychotic depression, endogenous depression, idiopathic depression and major depressive disorder. Bipolar disorder is now recognised as being heterogeneous bipolar disorder I is equivalent to classical manic depressive psychosis, or manic depression, while bipolar disorder II is depression with hypomania (Dean, 2002). Unipolar mania is where periods of mania alternate with periods of more normal moods. Seasonal affective disorder (SAD) refers to depression with its onset most commonly in winter, followed by a gradual remission in spring. Some milder forms of severe depression, often those with an identifiable cause, may be referred to as reactive or neurotic depression. Secondary depression is associated with other illnesses, such as neuro-degenerative or cardiovascular diseases, and is relatively common. 

Mood stabilisers are used to regulate the cyclical change in mood characteristic of bipolar disorder, since they can attenuate both manic and depressive phases. Their main use is as a prophylactic for manic depression and unipolar mania. However, they can also be administered concomitantly with antidepressants for refractory (non-responsive) unipolar depression. 

Outline the main types of unipolar and bipolar affective disorder, and describe their clinical symptoms. 

Affective disorders A group of psychoses characterised by a pathological and long-lasting disturbance of mood or affect. They include the unipolar disorders (e.g., depression and mania), and bipolar disorders (e.g., manic depression). 

Lithium The first drug to be used in the treatment of unipolar mania and bipolar disorder. 

Chen, Y. W. and Dilsaver, S. C. Lifetime rates of suicide attempts among subjects with bipolar and unipolar disorders relative to subjects with other Axis I disorders. Biol. Psych. 39 896-899,1996. 

Delusions, hallucinations, and suicide attempts are more common in bipolar depression than in unipolar depression. 

Furlong, R.A., et al., "Analysis and Meta-Analysis of Two Serotonin Transporter Gene Polymorphisms in Bipolar and Unipolar Affective Disorders," Am. ]. Med. Genet., 81, 58-63 (1998). 

The principle behind the use of surgical diathermy is that of current density. When a current is applied over a small area, the current density is high and heating may occur. If the same current is applied over a suitably large area then the current density is low and no heating occurs. For unipolar diathermy, the apparatus utilizes a small surface area at the instrument end and a large area on the diathermy plate to allow current to flow but to confine heating to the instrument alone. Bipolar diathermy does not utilize a plate as current flows directly between two points on the instrument. 

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