Large increases in resitivity of Ga0.47In0.53 As have been observed due to bombardment with hydrogen ion isotopes. After damage factors due to mass and dose of the implanted isotopes have been taken into account, the high resistivity values of proton and deutron bombarded Ga0.47In0.53 As agree,k contrasting with previous observations in GaAs. An explanation is offered.

Disorders of Acid-Base Balance M aintenance of acid-base homeostasis is a vital function of the living organism. Deviations of systemic acidity in either direction can impose adverse consequences and when severe can threaten life itself. Acid-base disorders frequently are encountered in the outpatient and especially in the inpatient setting. Effective management of acid-base disturbances, commonly a challenging task, rests with accurate diagnosis, sound understanding of the underlying pathophysiology and impact on organ function, and familiarity with treatment and attendant complications [1]. Clinical acid-base disorders are conventionally defined from the vantage point of their impact on the carbonic acid-bicarbonate buffer system. This approach is justified by the abundance of this buffer pair in body fluids; its physiologic preeminence; and the validity of the isohydric principle in the living organism, which specifies that all the other buffer systems are in equilibrium with the carbonic acid-bicarbonate buffer pair. Thus, as indicated by the Henderson equation, [H + ] = 24 ϫ PaCO 2 /[HCO-3 ] (the equilibrium relationship of the carbonic acid-bicarbonate system), the hydrogen ion concentration of blood ([H + ], expressed in nEq/L) at any moment is a function of the prevailing ratio of the arterial carbon dioxide tension (PaCO 2 , expressed in mm Hg) and the plasma bicarbonate concentration ([HCO-3 ], expressed in mEq/L). As a corollary, changes in systemic acidity can occur only through changes in the values of its two determinants, PaCO 2 and the plasma bicarbonate concentration. Those acid-base disorders initiated by a change in PaCO 2 are referred to as respiratory disorders; those initiated by a change in plasma bicarbonate concentration are known as metabolic disorders. There are four cardinal acid-base disturbances: respiratory acidosis, respiratory alkalosis, metabolic acidosis, and metabolic alkalosis. Each can be encountered alone, as a simple disorder, or can be a part of a mixeddisorder, defined as the simultaneous presence of two or more simple

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