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Magnetic head fabrication for >100 Gbit/in.2 areal density requires minimum lithographic feature size

Introduction Neuroimaging and experimental studies have related cytomegalovirus (CMV) to certain neuronal migration disorders. Material and methods To define the electroclinical picture of children with epilepsy associated with disorders of cortical development (DCD) and congenital CMV infection, we conducted a clinical, electroencephalographic and neuroradiological study of 10 children with this condition. Results Eighty per cent of them had dismorphic traits, or malformations outside CNS. All showed other neuroradiological signs (cerebral calcification, white matter damage, porencephaly). Six patients with bihemispheric DCD (agyria-pachigyria, 2; 'poligyria', 1; schizencephaly, 1; bilateral opercular DCD, 2) showed: Tetraparesis, severe or profound mental deficiency, early onset epilepsy (mean age at onset: 11 months) with spasms, tonic seizures, partial seizures, and multifocal paroxysms or unusual diffuse sharp Alfa-Beta EEG activity. One child developed Epilepsia Partialis Continua. Children with bilateral opercular DCD evolved to a continuous spike and wave (SW) electrical status during wakefulness and sleep, linked to a worsening of psychomotor derangement. Four patients with unilateral hemispheric DCD (pachigyric or 'poligyric') showed: Congenital hemiparesis, mild intellectual deficiency, motor seizures (orofacial, hemiclonic, generalized) beginning in the third year of live, atypical absences with focal phenomena, frequent focal rhythmic SW discharges during wakefulness, and continuous SW status during sleep (CSWS). Conclusions A wide spectrum of DCD due to congenital CMV infection is documented. Characteristic electroclinical pictures related to the extent and topographical distribution of the DCD are recognized, which may lead to an appropriate diagnosis and prognosis.

Interest in magnetic tunnel junctions (MTJ) has been increased by the recent observation of large room-temperature magnetoresistance (MR) in structures comprised of sandwiches of two ferromagnetic (FM) layers with different coercivities separated by a thin Al2O3 tunnel barrier. Using an ultrahigh vacuum dc magnetron sputtering system, a variety of MTJ structures have been explored. Junctions were fabricated directly using computer-controlled placement of successive contact masks, and by patterning using optical lithography techniques and processes, compatible with MR head structures. Structures were prepared in which one of the FM layers is exchange biased with an antiferromagnet MnFe layer. Thus, the junctions exhibit two well-defined magnetic states in which the FM layers are either parallel or antiparallel to one another. The tunnel barrier was prepared by in situ plasma oxidation of thin Al layers sputter deposited at room temperature. Using FM layers comprised of Co or permalloy (Ni81Fe19), MR values...

Routine use of the hydrogen platinum electrode system (HPES) in 1,375 consecutive cardiac catheterizations facilitated shunt detection in 171 patients, led to the diagnosis of unsuspected shunts in 18 patients, and was of particular value in accurately localizing unusual left-to-right shunts. Left-to-right shunts were detected in 171 patients (12% of the total catheterizations). Eighteen unsuspected shunts (10% of the total shunts, or 1% of the total catheterizations) were found. Atrial septal defect (ASD), partial anomalous pulmonary drainage (PAPVD), ventricular septal defect (VSD), and ruptured Valsalva aneurysm were demonstrated, usually associated with other congenital or acquired lesions. HPES was of particular value in accurately localizing the venous drainage of 38 unusual or complex lesions with left-to-right shunting. Five patients with rheumatic mitral valve disease had PAPVD, a higher incidence (1.2% of rheumatic mitral valve disease) than had previously been reported. The rationale for use of a sensitive shunt detection method as a routine part of the catheterization procedure is discussed.

Observations on the atrial systolic murmur, the tricuspid opening snap, and the right atrial pressure pulse of tricuspid stenosis are presented, based on catheter manometer intracardiac sound and pressure recordings in five patients with hemodynamically significant tricuspid stenosis. The manometer-recorded right atrial pressure pulse of tricuspid stenosis differed from the normal, with (1) elevation of right atrial pressure, (2) different morphologic features (tall, spiky A wave complete before C; small V wave with an interruption, the tricuspid opening snap notch at termination of the gradual Y descent; a diastolic plateau, the relatively flat diastolic segment of the right atrial pressure pulse following the tricuspid opening snap notch prior to the next A wave), and (3) the relative lack of right atrial pressure and right atrial pressure pulse response with normal respiration. The atrial systolic murmur, recorded in the right ventricular inflow tract, was complete by S1; the crescendo-decrescendo atrial systolic murmur configuration paralleled the right ventricular-right atrial diastolic pressure gradient at the time of the atrial A wave. The right atrial contraction-relaxation process, as reflected by the right atrial A wave ascent and descent, was complete at the onset of ventricular systole with P-R intervals of 170 to 200 msec. Thus, the timing and configuration of the atrial systolic murmur reflected the timing and completion of the right atrial contraction-relaxation process prior to the onset of right ventricular systole and the configuration of the tricuspid diastolic pressure gradient. The tricuspid opening snap was recorded in the right ventricular inflow tract and occurred at the time of a notch at the termination of the Y descent of the right atrial pressure pulse V wave, while right atrial pressure exceeded right ventricular pressure. The sound-pressure events were consistent with angiographic and echocardiographic studies, which showed doming or ballooning of the mobile, fused, stenotic tricuspid valve into the right ventricle during the Y descent of the right atrial pressure pulse. The tricuspid opening snap occurred at the time of the termination of the diastolic movement of the fused tricuspid unit into the right ventricle. These observations are presented within the framework of previous studies in order to trace the development of medical ideas about the pathophysiologic basis for the sound and pressure events of tricuspid stenosis.

Recent trends have led to the expanded use of digital computers in large complex system applications. The major burden of meeting the requirements for these systems has fallen on the flexibility of software. This has placed many demands on all areas associated with digital systems development. A significant impact has been on the development of software personnel required to develop and manage these complex systems. The purpose of this paper is to present a three level program for software education of executives, managers, and engineers which is being offered at the Air Force Institute of Technology (AFIT). The needs and approaches in satisfying software engineering education requirements are presented. Educational objectives for executives, managers, and engineers serve as the foundation of the curricula, courses, and topics presented.

To assess the effect of rapid preload reduction on left ventricular performance in nonischemic cardiomyopathy, 11 patients were studied during inferior vena caval (IVC) balloon occlusion. Five developed sustained pulsus alternans. During pulsus alternans, the strong beats demonstrated systolic performance characteristics similar to baseline values, despite a drop in both left ventricular (LV) end-diastolic diameter (66 +/- 13 to 61 +/- 13 mm; p less than 0.05) and LV end-diastolic pressure (21 +/- 8 to 9 +/- 6 mmHg; p less than 0.05). In contrast, the weak beats demonstrated a reduction in peak systolic pressure (130 +/- 36 to 109 +/- 33 mmHg; p less than 0.02), fractional shortening (20% +/- 4% to 17% +/- 9%; p less than 0.05) and peak positive dP/dt (1,006 +/- 224 to 921 +/- 287 mmHg; p less than 0.05). Measures of diastolic performance (peak negative dP/dt, the time constant of LV relaxation, the length of diastasis, and LV end-diastolic stress) were not different between baseline beats and the strong beats; and only LV end-diastolic stress differed when baseline beats were compared to the weak beats. When the strong beats were compared to the weak beats during induced pulsus alternans, significant differences were observed in peak systolic pressure, peak positive dP/dt, and fractional shortening, but no differences in any measured diastolic parameter was observed. A slight difference was noted in the left ventricular end-diastolic diameters, with the weak beat consistently beginning at a slightly smaller diameter (61 +/- 13; mm vs 59 +/- 13; p less than 0.05). In summary, these data are consistent with an augmentation and deletion of intrinsic contractile forces in association with an alternation in preload on a beat-to-beat basis as best describing left ventricular performance during pulsus alternans.

Systolic time intervals were measured in 26 patients with mitral regurgitation (acute in 14 and chronic in 12). In 13 of these patients (7 with acute and 6 with chronic mitral regurgitation) systolic time intervals were also measured after mitral valve replacement. Total electromechanical systole corrected for heart rate (Q-S2I) was of much shorter duration in the group with acute mitral regurgitation (472 ± 9 msec [mean ± standard error of the mean]) than in the group with chronic mitral regurgitation (516 ± 4.6 msec, P < 0.01). Before operation, the ratio of the preejection period (PEP) to left ventricular ejection time (LVET) and the angiographic ejection fraction did not differ in the groups with acute and chronic mitral regurgitation. The correlation between the PEPLVET ratio and ejection fraction was r = − 0.84, P < 0.01. Two weeks after operation, the PEPLVET ratio increased in all patients, but the increase was greater in those with lower preoperative values for this ratio. The mechanism of the early postoperative increase in the PEPLVET ratio is not clear, but serial studies performed over 6 months showed a return toward the preoperative value. It is concluded that preoperative systolic time intervals are useful for assessing left ventricular performance in all types of mitral regurgitation, but are especially useful for distinguishing between the acute and chronic varieties.

Striking auscultatory variations with changes in posture were observed in 30 individuals with either mid-late systolic clicks, late systolic murmurs, or both, particularly in the upright position. Twenty-seven patients had late systolic murmurs; in nine, however, the murmur was not heard until assumption of the sitting position. Mid-late systolic clicks were heard in 20 patients while supine and in three only on sitting. Click movement (usually toward the first sound) was common during sitting or standing. Late systolic murmurs became holosystolic in 25 patients. In 20, the murmur did not become holosystolic until standing. Systolic whoops, not heard in the supine position, developed on assumption of the sitting position (three patients) or standing (three patients). With prompt squatting, the auscultatory findings reverted to those heard in the supine position in eight of nine patients. All observations were confirmed with phonocardiograms. Structural alterations in the mitral valve complex resulting in systolic prolapse of leaflets into the left atrium occur in these patients. Posture related changes in mitral valve function most likely explain the auscultatory phenomena.

The simultaneous presence of oscillations locked in synchronism is investigated for circuits containing a nonlinear element. Under these conditions the circuit is called internally resonant, the two frequencies of oscillation being related by an integral ratio r/s. The discussion is confined to self-excitation in a highly oscillatory circuit connected across a nonlinear element. Nonlinear oscillations are generally characterized by a certain Fourier spectrum of the component frequencies; as a first approximation, it is reasonable to assume that only the fundamental components need be considered. The nonlinear element is described in terms of its current voltage characteristic and an equivalent linearized parameter defined by considering only the two fundamental frequencies. The variation-of-parameters method is applied to the resultant "linearized" equations and the equilibrium conditions determined. The conditions for stable equilibrium are then investigated by assuming a small departure from the equilibrium and studying the motion of the system following this displacement.

The relaxation rate of magnons has been measured in nominally pure CdCr2Se4 with the parallel pumping technique at 9.4 GHz, as a function of temperature T and wave vector k, for 4.2

The design and operating characteristics of a quarter mega‐bit, block replicate bubble memory device are reported in this paper. Replicate gate and swap gate designs are detailed. Characterization data obtained from packaged devices with computer controlled test systems show operating margins of 20 Oe from 0 to 50°C at 100 KHz rotating field frequency and 60 Oe peak triangular drive amplitude.

The top down planar process1 for the fabrication of Permalloy field access devices was extended from a 6.75×7.50‐μm cell2 to a 4.75×5.0‐μm cell with no major changes in the processing sequence. Direct step on wafer lithography, ion milling of the Permalloy, and plasma etching of AlCu were used in the device fabrication. Device topology was scaled, reducing the thicknesses of the Permalloy, oxide, and aluminum layers in order to decrease the permalloy‐garnet spacing. The results of this work show that Permalloy field access bubble devices with 5.0‐μm cells, 0.7‐μm gaps, and 1.5‐μm control lines can be processed over areas of 0.25–0.5 cm2, giving device capacities of 512 Kbits to 1 Mbit and device bit densities of 2×106/cm2.

We have imaged naturally occurring domains in soft magnetic films using the force microscope. Classic closure structures were seen in both sputtered and plated Permalloy films. These structures were compared to optical Kerr micrographs of the same films, with generally good correspondence. The force microscope had sufficient sensitivity and resolution to observe magnetic details such as ripple structure and a Bloch line. Clear evidence of tip‐induced wall motion was seen when the tip‐to‐sample separation was less than about 100 nm.

We have designed, fabricated and tested 10μm × 15μm barber-pole biased unshielded MR sensors. Results show that strong domain activities, inherent in these small elements, produce noisy MR responses without any observable biasing effects. Furthermore, we found that these domains, caused by magnetostatic effects, can be suppressed by applying an adequate longitudinal bias field. These findings lead to the fabrication of MR sensors with longitudinal exchange-biasing and transverse barber-pole biasing. These sensors produce quiet and strongly biased MR responses.

Focal brain ischemia developed in 10 normotensive patients during arteriography without systemic hypotension or cardiac ischemia, arrhythmias, or failure. Eight patients improved when blood pressures were increased with vasopressor drugs. Low-molecular-weight dextran, hyperosmotic agents, or corticosteroid drugs did not lower the blood pressure level needed for preservation of brain function in these patients and were not beneficial in the treatment of 4 others. Vasopressor drugs were useful in the treatment of 5 patients with brain ischemia secondary to systemic arterial hypotension who did not have cardiac ischemia, arrhythmias, or failure. Contraindications for vasopressor drug treatment include vascular dissections, myocardial and renal ischemia, left ventricular failure, and subaortic muscular stenosis.

We have measured bubble velocity as a function of drive field for 5 micron diameter bubbles in Ne+ ion implanted (YSmLuCa)3(FeGe)5O12 films over a 115°C temperature range from −40°C to +75°C. From this translation data the bubble mobility, μ, and dynamic coercivity, Hc, were determined. For material with a room temperature mobility of 500 cm/sec‐Oe, a mobility temperature coefficient of 1.1%/°C was calculated. Skew angle measurements were consistent with the identification of the S ≈ 1 bubble state as the only stable wall configuration over this temperature range.

This paper studies the different types of imagery likely to occur during the sleep/wake cycle in experiment subjects under part sensory deprivation conditions, where they are administered a sound-stimulus- namely an electronically recorded heart-beat which acts as propioceptive inductor. Meanwhile, a polysmonographic register in recorded so that a correlation between the time the imagery appears, and the states of consciousness likely to arouse the images is duly established. The study allows a fresh re-elaboration to be raised as regards imagery matureness and formation in the mind, a semiologic re-statement of imagery types, and a better understanding how the self works during sleep stage, dream state, and hypnagogic-hypnopompic phases as well. Finally, the authors stress up the importance of interpersonal relationship between the subjects and the research team, altogether with the frame of reference the professionals work in since their focusing could modify the sleep recording characteristics.

Ten women with primary pulmonary hypertension had resting hemodynamic measurements taken before and after the nonparenteral administration of various vasodilators and prostaglandin inhibitors. Only sublingual isoproterenol, alone or combined with sublingual isosorbide dinitrate, effected a substantial (greater than 20%) drop in pulmonary vascular resistance; this decrease was accompanied by little change in pulmonary artery pressure. Isosorbide dinitrate was the only drug that elicited any reduction in pulmonary artery pressure; pulmonary vascular resistance decreased modestly. The oral administration of diazoxide, hydralazine, phentolamine, and tolazoline elicited little change in pulmonary artery pressure or resistance. Except for tolazoline, all these agents significantly decreased systemic blood pressure and resistance. Prostaglandin inhibition by indomethacin (acute and chronic dosing) increased pulmonary and systemic vascular resistances and reduced cardiac output. Aspirin combined with dipyridamole elicited no changes. The vasodilators and prostaglandin inhibitors studied evoked little improvement in resting pulmonary hemodynamic abnormalities in primary pulmonary hypertension.

Mitral valve prolapse (MVP) is the most common congenital heart lesion, and the diagnosis is frequently made in young women of childbearing age. The management of this disorder during pregnancy has not been well studied. Our investigation reviews the outcomes of 42 pregnancies among 25 patients with MVP diagnosed before conception by the characteristic auscultatory and echocardiographic findings. All patients with no other cardiovascular disorder tolerated pregnancy well and developed no remarkable cardiac complications. Furthermore, the incidence of antepartum and intrapartum complications or signs of fetal distress was not greater when compared with pregnant patients with no known cardiac disorder (p greater than 0.05). Congestive heart failure occurred in one case in which premature labor with coexisting toxemia was treated with the combined intravenous administration of a beta adrenergic tocolytic drug, a glucocorticoid drug, and a large volume of fluids.

To investigate the safety and efficacy of inferior vena caval (IVC) balloon occlusion for preload alteration in humans, 13 patients with dilated cardiomyopathy were studied before and during repeated (total of 78) IVC occlusions. Left and right ventricular (LV and RV) micromanometer pressures were simultaneously measured and M-mode and 2-D echocardiograms were recorded at end expiration. Complications were limited to abdominal discomfort in 2 patients. With IVC occlusion, RV collapse fluoroscopically shifted the heart toward midline and ventricular septal motion was frequently disordered. Significant (p = 0.001) changes occurred in RV and LV systolic peak pressures (from 19 +/- 6 to 12 +/- 5 mm Hg and from 129 +/- 34 to 109 +/- 25 mm Hg, respectively). LV and RV end-diastolic pressures also decreased significantly (from 18 +/- 7 to 6 +/- 6 mm Hg and from 5 +/- 3 to 2 +/- 2 mm Hg, respectively) (both p less than or equal to 0.0055). Similarly, LV end-diastolic diameter decreased 13% (from 61 +/- 11 to 53 +/- 12 mm, p = 0.0002). Mean heart rate did not change significantly (from 76 +/- 19 to 78 +/- 21 beats/min). Thus, IVC balloon occlusion provides a safe method of repeatedly altering loading conditions in humans. This approach allows for acquisition of important information regarding cardiac chamber dynamics while minimizing the effects of reflex mechanisms and avoiding use of pharmacologic agents.

These observations are presented as a tentative step towards an ultimate classification of auscultatory events based on ICSP studies, chest wall phonocardiography, and auscultatory areas, with continuing clarification or modification by angiography, Doppler techniques, echocardiography, computer usage, and any available, useful technique. The ultimate diagnostic value of ICSP information resides in the feed-back loop wherein this information is used daily at the bedside as part of the understanding and explanation of daily auscultatory phenomena.

The need for and the design of invasive procedures in patients with valvular heart disease should be based on the careful evaluation of the patient with history, physical examination, and appropriate noninvasive testing. The number of parameters measured, angiograms performed, and interventions performed during catheterization is determined by the suspected pathology and the clinical status of the patient. The ability to amend the planned sequence and number of measurements as the study progresses must be preserved, so that the most useful data to be used in patient management can be obtained. Knowledge of the limitations as well as the advantages of each technique is necessary to obtain the most accurate data and to interpret the results obtained. It must be recognized that invasive procedures will not always answer all the questions and, in fact, may raise new ones. They are, however, an indispensible part of the evaluation of patients with valvular heart disease, as most surgical and many medical decisions cannot be made without them.

A 27-year-old woman presented with chief complaints of chest pain, palpitations, and fatigue. Her pain was substernal, sharp in character and sometimes radiated to the left arm. Left arm numbness occurred at times. The pain was periodically exertional, but also occurred at rest. It lasted minutes on some occasions, or hours on others. It was often worse in stressful situations, when it persisted for hours. Palpitations, which sometimes accompanied the chest pain, also occured at rest and with activity. They felt like a “fluttering” sensation and were at times associated with light-headedness. However, syncope had never occurred. She fatigued easily --- after a day selling cosmetics, she was tired for two or three days. Climbing one flight of steps resulted in fatigue. She slept on one pillow at night and had no peripheral edema. All of these symptoms had been occurring over several years, but had become gradually worse in recent months, leading to her referral for evaluation.

The enantiomers of salsolinol were completely separated as diastereoisomeric derivatives, after reaction with S-1-(1-naphthyl)ethyl isothiocyanate, by reversed-phase high-performance liquid chromatography and quantified by electrochemical detection. Good calibration curves were obtained for the quantification and determination of the enantiomeric composition of salsolinol in human urine. The sensitivity and specificity to the assay also permit the determination of the enantiomeric composition of salsolinol in food such as dried bananas and chocolate.

Absent pulmonic valve (APV) in tetralogy of Fallot produces a pulmonic regurgitation murmur (PRM) which is usually late in onset after A2, low pitched, and of crescendo-decrescendo character. We have seen three adult patients with tetralogy of Fallot with APV and have done intracardiac sound and pressure studies in two. The PRM was loudest in the RV outflow tract (RVOT), where the onset was earlier than the murmur recorded on the chest wall. The crescendo portion of the PRM occurred during an abnormally slow decline in the RVOT pressure pulse after the crossover of PA and RVOT pressures. The RVOT pressure reached its minimum 30 msec after the RV body pressure, resulting in a pressure gradient between the two. The PRM peaked 30 msec later in the RV body than in the RVOT. The delayed precordial onset of the PRM after A2 is likely due to failure of transmission of early vibrations through the chest wall. The morphology of the PRM in tetralogy of Fallot with APV may be related to delayed relaxation with altered diastolic compliance of the RVOT which is subjected to a large regurgitant volume from the massively dilated pulmonary arteries.

We present in this work a new artificial endocrine pancreas (BETALIKE), smaller than the available ones, transportable and fully automated. In the clinical trials performed this device showed good blood glucose controls and glycemic measurements were highly correlated with other automatic analyzer assays. No side effect was reported.

Little information is available concerning the progression of mild to severe mitral regurgitation (MR) in patients with mitral valve prolapse (MVP). This study reports 86 patients, average age 60 years, who presented with cardiac symptoms, precordial systolic murmur, severe MR and a high incidence of MVP on echocardiography (57 of 75 [75%] ) and left ventriculography (61 of 84 [73%] ). Seventy-five surgically excised mitral valves appeared grossly enlarged and floppy. Histologic studies showed extensive myxomatous changes throughout the leaflets and chordae. Eighty patients had had precordial murmurs first described at average age 34 years, but the average age at which symptoms of cardiac dysfunction appeared was 59. However, once symptoms developed, mitral valve surgery was required within 1 year in 67 of 76 patients who had undergone surgery. Atrial fibrillation, present in 48 of 86 patients (56%), or ruptured chordae tendineae, present in 39 of 76 patients (51%), may have contributed to this rapid progression and deterioration. Additionally, 13 patients had a remote history of documented infective endocarditis. Twenty-eight patients had at least 1 type of serial clinical evaluation that indicated progressive MR in all 28 patients on the basis of changing auscultatory findings (24 of 26), progressive radiographic cardiomegaly (24 of 25), echocardiographic left atrial enlargement (4.3 to 5 cm in 11 patients) and angiographically worsening MR (14 of 15). Twenty-four of these patients had evidence of MVP on at least 1 of their initial studies. Thus, mild MR due to MVP and myxomatous mitral valves is a progressive disease in some patients with MVP.