Impairments

Benzodiazepines have a low abuse potential when they are properly prescribed and their use is supervised (American Psychiatric Association 1990). However, physical dependence often occurs when benzodiazepines are taken at higher-than-usual doses or for prolonged periods. If benzodiazepines are discontinued precipitously, withdrawal effects (including hyperpyrexia, seizures, psychosis, and even death) may occur. Signs and symptoms of withdrawal may include tachycardia, increased blood pressure, muscle cramps, anxiety, insomnia, panic attacks, impairment of memory and concentration, perceptual disturbances, and delirium. In addition, withdrawal-related derealization, hallucinations, and other psychotic symptoms have been reported. These withdrawal symptoms may begin as early as the day after discontinuation of the benzodiazepine, and they may continue for weeks to months. Evidence indicates that withdrawal reactions associated with shorter-half-life benzodiazepines peak more rapidly and more intensely. 

Most psychoactive medications should be discontinued gradually. For patients who have been taking benzodiazepines for longer than 2-3 months, we suggest that the dose be decreased by approximately 10% per week. Therefore, in the case of a patient receiving alprazolam, 4 mg/day, the dose should be tapered by 0.5 mg/week for 8 weeks. 

Benzodiazepines are associated with anterograde amnesia, especially when they are administered intravenously and in high doses. 

The production of NO within or around neurons, can impart irreversible adverse affects on mitochondrial 02-dependent cellular respiration [21, 333, 334]. Degenerative diseases that involve NO correspond to toxicity that parallels the loss of mito- 

In the mitochondria, ONOO- can mediate damage to OXPHOS by nitrosylat-ing/oxidizing tyrosine or thiol functional groups, rendering catalytic inactivation of complex I [NADH ubiquinone oxidoreductase], complex II [succinate ubiquinone oxidoreductase] and complex V (FI, FO-ATPase), thereby impeding ETC/ OXPHOS 

---

Short-term exposure. This is the maximum concentration to which workers can be exposed for a period of up to 15 minutes continuously without suffering from (a) intolerable irritation, (b) chronic or irreversible tissue change, or (c) narcosis of sufficient degree to increase accident proneness, impair self-rescue, or materially reduce efficiency, provided that no more than four excursions per day are permitted, with at least 60 minutes between exposure periods, and provided the daily time-weighted value is not exceeded. 

Injection gas pressures are usually much higher than lift-gas or gas pipeline pressures and special care has to be taken to select compressor lubricants that will not dissolve in high pressure gas. Such a situation could lead to inadequate lubrication and may impair well injectivity. 

Normally acid would be allowed to soak for some time and then back-produced if possible along with the impairing products. One of the advantages of using coiled tubing is that it can be inserted against well head pressure so the well does not have to be killed a potentially damaging activity. 

Injection of produced water is not a new idea, but the technique has met resistance due to concerns about reservoir impairment (solids or oil in the water may block the reservoir pores and reducing permeability). However, as a field produces at increasingly high water cuts, the potential savings through reduced treatment costs compared with the consequences of impairment become more attractive. 

If the initial spreading coefficient for liquid b spreading on liquid n is to be just zero, what relationship between ya and 7 is impair by the simple Girifalco-Good equation ... 

If the total surface area is small (say, a few hundred square centimeters), the amount adsorbed becomes so little that measurements are difficult by normal procedures. Thus the change in pressure-volume product on admitting gas to the adsorbent becomes so small that precision is impaired. 

For a reconstmcted surface, the effect of an adsorbate can be to provide a more bulk-like enviromnent for the outemiost layer of substrate atoms, thereby lifting the reconstmction. An example of this is As adsorbed onto Si(l 11)-(7 X 7) [37]. Arsenic atoms have one less valence electron than Si. Thus, if an As atom were to replace each outemiost Si atom in the bulk-temiinated stmcture, a smooth surface with no impaired electrons would be produced, with a second layer consisting of Si atoms in their bulk positions. Arsenic adsorption has, in fact, been found to remove the reconstmction and fomi a Si(l 11)-(1 x l)-As stmcture. This surface has a particularly high stability due to the absence of dangling bonds. 

Because the neutron has a magnetic moment, it has a similar interaction with the clouds of impaired d or f electrons in magnetic ions and this interaction is important in studies of magnetic materials. The magnetic analogue of the atomic scattering factor is also tabulated in the International Tables [3]. Neutrons also have direct interactions with atomic nuclei, whose mass is concentrated in a volume whose radius is of the order of... 

A sine-shape has side lobes which impair the excitation of a distinct slice. Other pulse envelopes are therefore more commonly used. Ideally, one would like a rectangular excitation profile which results from a sine-shaped pulse with an infinite number of side lobes. In practice, a finite pulse duration is required and therefore the pulse has to be truncated, which causes oscillations in the excitation profile. Another frequently used pulse envelope is a Gaussian frmction ... 

In equation (bl. 15.24), r is the vector coimecting the electron spin with the nuclear spin, r is the length of this vector and g and are the g-factor and the Boln- magneton of the nucleus, respectively. The dipolar coupling is purely anisotropic, arising from the spin density of the impaired electron in an orbital of non-... 

The UIIF wnive fimction can also apply to singlet molecules. F sn-ally, the results are the same as for the faster RHF method. That is, electron s prefer to pair, with an alpha electron sh arin g a m olecu lar space orbital with a beta electron. L se the L lIF method for singlet states only to avoid potential energy discontinuities when a covalent bond Is broken and electron s can impair (see Bond Breaking on page 46). 

The precision of a result is its reproducibility the accuracy is its nearness to the truth. A systematic error causes a loss of accuracy, and it may or may not impair the precision depending upon whether the error is constant or variable. Random errors cause a lowering of reproducibility, but by making sufficient observations it is possible to overcome the scatter within limits so that the accuracy may not necessarily be affected. Statistical treatment can properly be applied only to random errors. 

Microreticular Resins. Microreticular resins, by contrast, are elastic gels that, in the dry state, avidly absorb water and other polar solvents in which they are immersed. While taking up solvent, the gel structure expands until the retractile stresses of the distended polymer network balance the osmotic effect. In nonpolar solvents, little or no swelling occurs and diffusion is impaired. 

Membrane transport Memory Memory banks Memory device Memory-enhancing drug Memory-impairment Memory protection Memory storage device Memory systems Menadione... 

Aquatic animals are susceptible to a variety of diseases including those caused by viruses, bacteria, fungi, and parasites. A range of chemicals and vacciaes has been developed for treating the known diseases, although some conditions have resisted all control attempts to date and severe restrictions on the use of therapeutants ia some nations has impaired that abiUty of aquaculturists to control disease outbreaks. The United States is a good example of a nation ia which the variety of treatment chemicals is limited (Table 6). 

Approximately 500,000 Americans suffer strokes each year. Many of the 80% that survive suffer paralysis and impaired vision and speech, often needing rehabiUtation and/or long-term care. Hence, whereas treatment using rt-PA is likely to be expensive (costs are 2200/dose for treating heat attacks), the benefits of rt-PA could outweigh costs. In the case of heart attacks, the 10 times less expensive microbiaHy derived streptokinase can be used. There is currentiy no competing pharmaceutical for treatment of strokes (18,19). Consequentiy, the cost of manufacture of rt-PA may not be as dominant an issue as would be the case of other types of bioproducts. 

Cortisol-Cortisone Conversion. Under normal conditions, this equilibrium slightly favors the oxidized compound. Similarly, the conversion of corticosterone to 11-deoxycorticosterone is also mediated by the liP-hydroxysteroid dehydrogenase enzyme system and requites NAD(P) /NAD(P)H. This conversion is especially important both in the protection of the human fetus from excessive glucocorticoid exposure, and in the protection of distal nephron mineral ocorticoid receptors from glucocorticoid exposure (14). The impairment of this conversion is thought to result in hypertension associated with renal insufficiency (15). 

Nondestmctive evaluation, also termed nondestmctive testing or nondestmctive inspection, is extensively used in weld testing (14). Nondestmctive tests do no impair the serviceabiUty of the material or component under stress. The most widely used tests for evaluation of welds are Hquid penetrant, magnetic particle, ultrasonics, and radiography. Acoustic-emission tests are increasingly used. Nondestmctive tests detect and characterize, in terms of size, shape, and location, the various types of weld discontinuities that can occur. 

The xylenes are mildly toxic. They ate mild skin irritants, and skin protection and the cannister-type masks are recommended. The oral LD q value for rats is 4300 ppm. The STEL for humans is 150 ppm. Xylenes show only mild toxicity to fish, and the threshold limit for crop damage is 800—2400 ppm. Biodegradation with activated seed is slow, and sewage digestion is impaired by 0.1% concentrations. In the event of a spih, oil-skimming equipment, adsorbent foam, and charcoal maybe used for cleanup. 

Entrainment occurs when spray or froth formed on one tray enters the gas passages in the tray above. In moderate amounts, entrainment will impair the countercurrent action and hence drastically decrease the efficiency. If it happens in excessive amounts, the condition is called priming and will eventually flood the downcomers. 

The unit has virtually the same flow sheet (see Fig. 2) as that of methanol carbonylation to acetic acid (qv). Any water present in the methyl acetate feed is destroyed by recycle anhydride. Water impairs the catalyst. Carbonylation occurs in a sparged reactor, fitted with baffles to diminish entrainment of the catalyst-rich Hquid. Carbon monoxide is introduced at about 15—18 MPa from centrifugal, multistage compressors. Gaseous dimethyl ether from the reactor is recycled with the CO and occasional injections of methyl iodide and methyl acetate may be introduced. Near the end of the life of a catalyst charge, additional rhodium chloride, with or without a ligand, can be put into the system to increase anhydride production based on net noble metal introduced. The reaction is exothermic, thus no heat need be added and surplus heat can be recovered as low pressure steam. 

The discovery (92) that the graphite coating of molecular sieves can dramatically improve their attrition resistance without significantly impairing adsorption performance should allow the extension of moving-bed technology to bulk gas separations (93). 

Difficulties of Moving-Bed Operation. The use of a moving bed iatroduces the problem of mechanical erosion of the adsorbent. Obtaining uniform flow of both soHd and Hquid ia beds of large diameter is also difficult. The performance of this type of operation can be gready impaired by nonuniform flow of either phase. 

---