Showing papers by "Drexel University published in 1972"
201 citations
TL;DR: In this article, a technique for measuring instantaneous atmospheric temperature profiles is given, using the portion of the laser backscatter arising from the Raman rotational spectrum of N2.
Abstract: A technique for measuring instantaneous atmospheric temperature profiles is given. Utilizing the portion of the laser backscatter arising from the Raman rotational spectrum of N2, profiles up to 2 km with 100 m depth resolution provide temperature to within a degree with signal-to-noise ratios of order unity. Examples are given.
193 citations
TL;DR: Because of the high risk of sudden death, coronary arteriography should be performed with caution in a patient with severe angina pectoris, very positive findings on exercise testing, easily induced angina and heart failure with stress and calcification in the left main coronary artery.
Abstract: Thirty patients with 70 percent or greater obstruction in the left main coronary artery were evaluated during hemodynamic and angiographic studies. There were 25 male and 5 female patients; the average age was 54 years. Twenty-seven patients had moderate to severe angina pectoris, with 14 noting an increase in severity of chest pain within 6 months before arteriography. Six patients also had hemodynamic evaluation by atrial pacing. In each, angina pectoris was easily induced, and all 6 had abnormal pacing ventricular function curves with marked increase in left ventricular end-diastolic pressure associated with a reduction in left ventricular stroke work. Image intensification fluoroscopy revealed calcification in the left main coronary artery in 7 patients. A striking finding was the severity of obstructive disease in the other coronary arteries. Eight patients had total occlusion of the right coronary artery, and 29 of the 30 patients had 2- or 3-vessel disease. Significant coronary arterial collateral vessels were noted in 21 patients. Contraction abnormalities were present in 24 left ventriculograms. Three deaths were associated with cardiac catheterization (mortality rate 10 percent). Only 2 of 18 patients who underwent aortocoronary bypass surgery died. The 16 surgical survivors are in clinically improved condition after a follow-up period of 10 months. Three of 9 patients not operated on have died, all within 1 month of arteriography. Because of the high risk of sudden death, coronary arteriography should be performed with caution in a patient with severe angina pectoris, very positive findings on exercise testing, easily induced angina and heart failure with stress and calcification in the left main coronary artery. After cardiac catheterization all patients should undergo routine monitoring and, when technically feasible, saphenous vein aortocoronary bypass surgery should be performed.
175 citations
163 citations
TL;DR: In this paper, a set of macroscopic elastic constants is developed in terms of the properties of the constituent layers by considering a representative small element of the laminated medium and imposing the condition of continuity of stress and displacement at the layer interfaces.
Abstract: A three-dimensional laminated medium is studied by an approach which replaces the heterogeneous medium by an equivalent homogeneous material. A set of macroscopic elastic constants is developed in terms of the properties of the constituent layers by considering a representative small element of the laminated medium and imposing the condition of continuity of stress and displacement at the layer interfaces. An example boundary value problem is also considered. Based on the solution of the boundary value problem for the homogeneous material, stress and strain fields corresponding to each layer are then calculated. This individual layer solution contains certain dis continuous stresses and strains as does the exact solution for the layered material.
150 citations
TL;DR: Data on information flow in psychology reveal a lengthy series of disseminatins to various audiences, which furnish an empirical base for Ziman's consensual model of science and illuminate difficulties which have arisen in the design and implementation of information systems.
134 citations
TL;DR: The findings imply that a vasopressor substance of renal origin increasing peripheral resistance is the major factor in the pathophysiology of renal hypertension in the late stage of its natural history.
Abstract: This study was undertaken to define the hemodynamic changes in hypertension of chronic end-stage renal disease. Mean cardiac index in 75 uremic patients was higher (P < 0.001) than that of 42 normal volunteers while stroke index was not different from normals. The higher cardiac indices of uremic patients were accounted for by increased heart rates. Despite the significantly higher blood pressure in the uremics, their mean total peripheral resistance index was not different from that of normals. The total group of 75 patients included 52 hypertensive and 23 normotensive uremics. Cardiac index, heart rate, and stroke index were the same in 52 hypertensive and 23 normotensive uremics while mean total peripheral resistance index of hypertensive uremics was higher (P < 0.001) than normotensive uremics. Therefore, the hypertension in end-stage renal disease is sustained by a high total peripheral resistance. Bilateral nephrectomy in 12 hypertensive uremics resulted in no changes in cardiac index; a consistent ...
106 citations
TL;DR: There was a significant reduction in glycosaminoglycans from newborn to infants; with the levels remaining stable through middle age and dropping further during old age.
100 citations
TL;DR: The data suggest that in scleredema there may be an increase in hyaluronic acid while the concentration of dermatan sulfate is normal, and all scleroderma specimens revealed a marked increase in dermatAn sulfate.
98 citations
92 citations
TL;DR: In this article, several types of measurement and scaling models are applied to empirical data involving a sample of housewives' preferences for profile descriptions of retail discount cards, and the results indicate that additive conjoint models provide good descriptions of the data and that self-explicated models also show reasonable accuracy in predicting actual rankings.
Abstract: Several types of measurement and scaling models are applied to empirical data involving a sample of housewives' preferences for profile descriptions of retail discount cards. Additive conjoint measurement is used to obtain part-worth functions for the various component descriptors. In addition, subjects' self-explicated models are compared with actual rankings of the discount cards. The results of the study indicate that additive conjoint models provide good descriptions of the data and that self-explicated models also show reasonable accuracy in predicting actual rankings. However, no significant association was found between differences in evaluative behavior and a battery of attitudinal and socio-economic measurements obtained from the same subjects.
TL;DR: Cefazolin is an effective cephalosporin which can be used intramuscularly for therapy of serious bacterial infections and its major advantages over other cep Halosporins are higher, more sustained concentrations in the blood and apparent lack of pain on intramuuscular injection.
Abstract: Cefazolin sodium, a cephalosporin for parenteral use, was evaluated in vitro and in 26 patients. Cefazolin had activity equivalent to cephalothin against Streptococcus pneumoniae, Staphylococcus aureus, group A streptococci, and Proteus mirabilis. Cefazolin was four- to eightfold more active against Escherichia coli and slightly more active against Klebsiella pneumoniae, whereas cephalothin was slightly more active against indole-positive Proteus species. After a 500-mg dose of cefazolin intramuscularly, peak concentrations in the serum were high enough to inhibit all strains of S. pneumoniae, S. aureus, group A streptococci, E. coli, K. pneumoniae, and P. mirabilis, as well as 60% of strains of Proteus species other than P. mirabilis. All of 26 patients (18 with pneumonia, 6 with urinary tract infection, and 2 with skin infections) responded clinically and bacteriologically to cefazolin therapy. There were no major side effects of therapy, and no patient complained of pain at the site of intramuscular injection. Cefazolin is an effective cephalosporin which can be used intramuscularly for therapy of serious bacterial infections. Its major advantages over other cephalosporins are higher, more sustained concentrations in the blood and apparent lack of pain on intramuscular injection.
TL;DR: In this paper, the stress and displacement distribution in a finite layered medium, statically loaded at the surface, is found by means of transfer matrices, where each layer is of infinite extent in the horizontal direction, of constant depth, and is considered to be linearly elastic, homogeneous and isotropic.
Abstract: The stress and displacement distribution in a finite layered medium, statically loaded at the surface, is found by means of transfer matrices. Each layer is of infinite extent in the horizontal direction, of constant depth, and is considered to be linearly elastic, homogeneous and isotropic. The method developed has the built-in advantage of enforcing interface continuity conditions automatically. Its flexibility is shown by applying the technique to layered composites, in which case it predicts local as well as global behavior with equal ease.
TL;DR: Electrophysiological interactions of Mg and K ions were studied in isolated rabbit heart preparations, and threefold increase in extracellular Mg concentration tended to increase the action potential amplitude, membrane resting potential, maximal rate of depolarization, and action potential duration of ventricular muscle fibres, and prolonged the A-V conduction time.
Abstract: Electrophysiological interactions of Mg and K ions were studied in isolated rabbit heart preparations Threefold increase in extracellular Mg concentration, in the presence of either high (7·5 mM), normal (4·5 mM), or low (1·5 mM) K concentration, tended to increase the action potential amplitude, membrane resting potential, maximal rate of depolarization, and action potential duration of ventricular muscle fibres, and prolonged the A-V conduction time These effects were more prominent at higher K concentrations Reduction of Mg concentration to one third produced opposite results Prolongation of the effective refractory, by high Mg was greater than that of the action potential duration This resulted in a better propagation of the earliest premature response Low Mg shortened the effective refractory, but tended to prolong the relative refractory period, and increased ventricular vulnerability Possible ionic mechanisms underlying these Mg effects were discussed in comparison with Ca action
TL;DR: In this paper, the authors combine economic load allocation and supplementary control action into a single dynamic optimal control problem to overcome the disadvantages of static optimization techniques to solve the economic load assignment problem.
Abstract: Electric utilities presently use static optimization techniques to solve the economic load allocation problem. Experience has shown that a number of difficulties arise when these solutions are incorporated in the feedback control of dynamic electric power networks. This research attempts to overcome the disadvantages of such controllers by combining economic load allocation and supplementary control action into a single dynamic optimal control problem.
TL;DR: Three patients are presented who had typical clinical and laboratory findings of acute myocardial infarction and normal coronary arteriograms, and none had major predisposing factors to precocious coronary atherosclerosis.
Abstract: Myocardial infarction with normal coronary arteriographic findings is rare. Three patients are presented who had typical clinical and laboratory findings of acute myocardial infarction and normal coronary arteriograms. Two patients were male, 16 and 24 years old, respectively, and 1 was female, aged 36 years. None had major predisposing factors to precocious coronary atherosclerosis. Thrombocytosis was considered to be the etiologic factor in 1 male patient; no etiologic factor could be traced in the other male patient; estrogen therapy may be considered as the cause of the myocardial infarction in the female patient.
TL;DR: Theoretical and experimental studies of the free vibrations and the loss of stability of thick-walled cylindrical and spherical shells subjected to external pressure are presented in this article, where general equations for the oscillations of the shell under pressure are formulated on the basis of a rigorous theory of finite elasticity.
Abstract: Theoretical and experimental studies of the free vibrations and the loss of stability of thick-walled cylindrical and spherical shells subjected to external pressure are presented. General equations for the oscillations of the shell under pressure are formulated on the basis of a rigorous theory of finite elasticity. Loss of stability is determined when the fundamental natural frequency of the prestressed shell ceases to be real-valued. Numerical solutions are obtained by solving the specialized equations that are applicable to neo-Hookean materials. Experi- ments using specimens made of silicone rubber closely verify the theoretical results.
TL;DR: Testosterone did maintain ESF excretion on deletion of HGH from the regimen, suggesting at least one common mode of action for these hormones in the hypoanabolic subject, and testosterone failed to maintain the plasma volume increase induced by HGH and did not further effect the observed bone marrow lymphocytosis.
TL;DR: Whenever a nerve is sectioned and continuity with its distal counterpart cannot be re-established, a neuroma of sorts results.
TL;DR: It is concluded that the removal and utilization of ketones is of physiological importance in the brain of newborn animals.
Abstract: The removal of circulating ketone bodies by the brain was investigated in 0- to 8-day-old puppies under pentobarbital anaesthesia. Of the arterial acetoacetate (AcAc) and β-hydroxybutyrate (βOHB), 24 and 30 per cent, respectively, were removed by the brain. There was a direct correlation between the arterial concentrations of either AcAc or βOHB and the A-V difference of the respective ketone body across the brain. When a continuous infusion of Na-dl-3-hydroxybutyrate [3-14T] was administered for more than 2 h, labelling of both phospholipids and free cholesterol was consistently observed in all six areas of the brain that were sampled. We conclude that the removal and utilization of ketones is of physiological importance in the brain of newborn animals.
TL;DR: The phonocardiogram revealed a systolic ejection and early diastolic sound, both of which may be the result of tumor movement, in a case of a right atrial myxoma successfully removed surgically and presenting clinically as right heart failure.
TL;DR: In this paper, the magnetic properties of spin-textonehalf{} Heisenberg ferromagnetic alloys are calculated using a coherent-potential approximation (CPA) method.
Abstract: The magnetic properties of spin-\textonehalf{} Heisenberg ferromagnetic alloys are calculated. We calculate the spin-wave Green's function in the random-phase approximation and treat the disordered composition-dependent exchange interaction in a coherent-potential approximation (CPA). In the weak-scattering limit, the CPA reproduces the result of the mean-field theory as expected, and in the strong-scattering limit, the CPA predicts such properties as critical concentration, which is beyond the scope of the mean-field theory.
TL;DR: In this paper, the spectral, magnetic and conductance properties of 2,6-lutidine N-oxide (LNO) with various metal nitrates and thiocyanates were investigated.
TL;DR: In this paper, the fine structure of endocrine cells observed in normal human stomachs was described and four morphological types could be identified: ECL, G, EC, D, and ECL cells were observed in each section of the body, but were not positively identified in the pylorus.
TL;DR: The personal and family histories of alcoholics were compared with nonalcoholics and with non-alcoholic criminals as discussed by the authors, and the results suggest that interactionist theories of the etiology of alcoholism are...
Abstract: The personal and family histories of alcoholics were compared with nonalcoholics and with nonalcoholic criminals. The results suggest that interactionist theories of the etiology of alcoholism are ...
TL;DR: The ability of aspartate to serve as effectively as glutamate as the sole source of nitrogen for the growth of yeast apparently resides in their ability to utilize as partate for amino acid biosynthesis via transamination.
Abstract: Ammonia assimilation has been investigated in four strains of Saccharomyces cerevisiae by measuring, at intervals throughout the growth cycle, the activities of several enzymes concerned with inorganic ammonia assimilation. Enzyme activities in extracts of cells were compared after growth in complete and defined media. The effect of shift from growth in a complete to growth in a defined medium (and the reverse) was also determined. The absence of aspartase (EC 4.3.1.1, l-aspartate-ammonia lyase) activity, the low specific activities of alanine dehydrogenase, glutamine synthetase [EC 6.3.1.2, l-glutamate-ammonia ligase (ADP)], and the marked increase in activity of the nicotinamide adenine dinucleotide phosphate-linked glutamate dehydrogenase (NADP-GDH) [EC 1.4.1.4, l-glutamate:NADP-oxidoreductase (deaminating)] during the early stages of growth support the conclusion that yeasts assimilate ammonia primarily via glutamate. The NADP-GDH showed a rapid increase in activity just before the initiation of exponential growth, reached a maximum at the mid-exponential stage, and then gradually declined in activity in the stationary phase. The NADP-GDH reached a higher level of activity when the yeasts were grown on the defined medium as compared with complete medium. The nicotinamide adenine dinucleotide-linked glutamate dehydrogenase (NAD-GDH) [EC 1.4.1.2, l-glutamate:NAD-oxidoreductase (deaminating)] showed only slight increases in activity during the exponential phase of growth. There was an inverse relationship in that the NADP-GDH increased in activity as the NAD-GDH decreased. The NAD-GDH activity was higher after growth on the complete medium. The glutamate-oxaloacetate transaminase (EC 2.6.1.1. l-aspartate:2-oxoglutarate aminotransferase) activity rose and fell in parallel with the NADP-GDH, although its specific activity was somewhat lower. Although other ammonia-assimilatory enzymes were demonstrable, it seems unlikely that their combined activities could account for the remainder of the ammonia-assimilatory capacity not accounted for by the NADP-GDH. The ability of aspartate to serve as effectively as glutamate as the sole source of nitrogen for the growth of yeast apparently resides in their ability to utilize aspartate for amino acid biosynthesis via transamination.
TL;DR: The garfish olfactory and trigeminal nerves were studied for their lipid composition and showed the presence of large proportions of long chain, highly unsaturated fatty acids, namely C20:4 and C22:6, were preferentially located in phosphatidylethanolamine,osphatidylserine and phosphatIDylinositol.
TL;DR: Pacing studies indicated little improvement in myocardial performance after aortocoronary arteryvein bypass surgery and the main hemodynamic difference between the normal subject and the patient with coronary artery disease was the failure of the left ventricular end-diastolic pressure to decrease during pacing in the latter.
Abstract: Right atrial pacing studies were performed in 58 patients with coronary artery disease and in 15 normal subjects. Angina pectoris was induced in 58 percent of patients with coronary artery disease at an average heart rate of 129 ± 3 beats/min; ischemic S-T segment depression was noted in 63 percent of such patients experiencing angina pectoris and in 31 percent of those without angina. The greater the severity of coronary artery disease, the more frequent the pacing-induced angina. The main hemodynamic difference between the normal subject and the patient with coronary artery disease was the failure of the left ventricular end-diastolic pressure to decrease during pacing in the latter. Pacing ventricular function curves were abnormal in 60 percent of patients with coronary artery disease in the absence of angina pectoris and abnormal in 90 percent during induced chest pain. Pacing studies were safely performed in 8 patients with unstable angina pectoris, with angina induced by pacing in 7. No significant hemodynamic differences were noted between these patients and those with stable coronary artery disease. Significant postoperative hemodynamic abnormalities were noted in 9 patients; preoperative and postoperative studies indicated little improvement in myocardial performance after aortocoronary arteryvein bypass surgery.
TL;DR: The lipid profile of sarcotubular membranes is relatively simple compared with most other membranes, and it is concluded that neither cholesterol nor other neutral lipids are components of the membranes studied.
Abstract: The lipid composition of a highly purified preparation of rat skeletal muscle sarcoplasmic reticulum was studied. These membranes contain per mg of protein 0.50 ± 0.02 μmoles of phosphatidylcholine, 0.13 ± 0.02 μmoles of phosphatidylethanolamine and 0.07 ± 0.02 μmoles ofphosphatidylinositol. These three components account for 97.3% of total lipid phosphorus. Unlike other mammalian membranes so far studied, this preparation contains neither sphingomyelin nor phosphatidylserine. Neural lipids were also measured and it is concluded that neither cholesterol nor other neutral lipids are components of the membranes studied. The results of this study indicate therefore that the lipid profile of sarcotubular membranes is relatively simple compared with most other membranes.
TL;DR: Simultaneous platelet and fibrinogen survival kinetic studies utilizing 75Seselenomethionine revealed that platelet survivals were increased in CML as compared to patients with the other myeloproliferative disorders (MPD).
Abstract: Simultaneous platelet and fibrinogen survival kinetic studies utilizing 75Seselenomethionine was performed on six patients with chronic myelogenous leukemia (CML), four with polycythemia vera (PV), one with idiopathic thrombocytosis (IT), and seven with myelofibrosis and myeloid metaplasia (MMM). The data revealed that platelet survivals, as well as fibrinogen survivals, were increased in CML as compared to patients with the other myeloproliferative disorders (MPD). Platelet survival was shortened in the patients with MPD as compared to the control patients. Thrombotic episodes were noted in three patients with MPD, while another had recurrent rectal bleeding. In all of these patients, platelet turnover was increased and was the only consistent determinant of hemostatic abnormality. Platelet adhesiveness and aggregation studies were inconsistently altered in any group and were not useful predictors of the risk of hemorrhagic or thrombotic diathesis. The data suggest that the platelets produced by patients with CML are functionally abnormal and underutilized when compared to control patients and to patients with other MPD. The thrombocytosis of CML results from decreased platelet utilization rather than from overproduction. Overutilization of platelets in patients with other MPD contributes to the thrombotic tendency noted in these patients. These results suggest another distinctive feature which separates CML from the other MPD. Platelet and fibrinogen kinetic studies are important in evaluating the pathophysiology of the thrombocytopenia or thrombocytosis of the myeloproliferative diseases as well as in investigating the physiology of hemostasis.