1,720,961 research outputs found
Effect of citicoline on some parameters of platelet aggregation in acute myocardial infarction
No full textWe studied the effect of the intravenous administration (slowly over 3 minutes) of citicoline (500 mg every 12 hours for 30 days) on some indices of platelet aggregation activity (platelet factor 4 (PF4), beta-thromboglobulin (B-TG), thromboxane B2 (TxB2), spontaneous and ADP-induced aggregation) in patients with acute myocardial infarction, admitted to hospital within 12 hours from onset of chest pain. The study design was double-blind: 15 patients were treated with placebo (Group A) and 15 patients with citicoline (Group B). The two groups of patients were homogeneous with respect to the incidence of risk factors for ischemic heart disease, size of infarcted area (estimated with both enzyme assays and electrocardiography recordings) and incidence of complications (arrhythmias, congestive heart failure, cardiogenic shock). No patient died during the study period. In Group A, the highest PF4 value was observed 24 hours after admission (X̄ ± S.E. = 36.9 ± 4.6 ng/ml). Thereafter we observed a decrease until day 10 (X̄ ± S.E. = 31.5 ± 4.5 ng/ml), a subsequent increase (X̄ ± S.E. = 34.1 ± 6.2 ng/ml on day 19) and finally another decrease (X̄ ± S.E. = 26.8 ± 5.4 ng/ml on day 30). In Group B, instead, a constant decrease in plasma values of PF4 was observed (from 36.6 ± 5.6 ng/ml on admission to 17 ± 3.5 ng/ml on day 30). Statistical comparison between the two groups revealed significantly lower values of PF4 in Group B especially with regards to the PF4 peaks seen on days 1 and 19 (1st, 2nd, 3rd, 4th, 5th, 13th, 14th, 15th, 17th, 18th, 19th, 20th, 21st, 22nd, 23rd, 24th, 25th, 26th day). With regards to B-TG, statistical comparison between the two groups of patients revealed significant lower values in Group B only occasionally in the study period (5th, 10th, 12th, 13th, 14th, 28th day). In Group B, patients' plasma TxB2 values were significantly lower in the first few days of the study (1st, 2nd, 5th, 6th, 11th day). No statistically significant differences were observed between the two groups in the spontaneous and ADP-induced platelet aggregation activity. From the results obtained in this study it may be concluded that citicoline is able to decrease platelet activation in patients with acute myocardial infarction probably through a mechanism of platelet membranes stabilization, especially those of the alpha granules. The drug does not appear to have an effect on cyclo-oxygenase activity since it does not significantly affect plasma TxB2 concentrations
Comparison of verapamil versus propranolol therapy in syndrome X
No full textThe effects of oral verapamil, 320 mg daily, propranolol, 120 to 160 mg daily, and placebo were compared in 16 patients presenting with transient myocardial ischemia without evidence of coronary atherosclerosis or vasospasm on angiography (syndrome X). Testing was done according to a randomized double-blind crossover placebo-controlled trial consisting of 3 consecutive 7-day treatment periods with verapamil or propranolol or placebo. Patients underwent continuous 48-hour electrocardiographic monitoring before therapy (run-in phase) and during the last 2 days of each treatment period. A total of 391 episodes of diagnostic (≥0.15 mV) ST depression was recorded during the trial. Of these, 23 were symptomatic. None of the episodes occurred while the patients were asleep, 25% during exercise, 35% during minimal physical activity and 40% at rest. Rest included activities demanding mental arousal (conversation, reading or watching television). Heart rate at the onset of ST depression was higher (≥10 beats/min) than that observed in the 5 minutes preceding ischemia in 95% of the episodes. In the group as a whole, the average number of ischemic episodes per 24 hours was significantly reduced during propranolol therapy compared with placebo (0.7 ± 0.6 vs 3.9 ± 1.8; p < 0.0005). No significant differences were seen during verapamil treatment (3.4 ± 1.7 vs 3.9 ± 1.8). It is concluded that transient myocardial ischemia in syndrome X is mostly precipitated by an increase in oxygen consumption, presumably due to a heightened sympathetic activity. Accordingly, β blockers may represent the first line of treatment. © 1989
Cognitive grasping system: A grasping solution for industrial robotic manipulation using convolutional neural network
Full text linkIn the modern era, object grasping has thousands of use cases across industries and loads of manual effort is devoted to repetitive tasks. Automating this task is important and the use of robots with embedded artificial intelligence is the key for improving grasping operations. Over the years many researches have been working on object grasping to make this operation as flexible as possible. Starting from the latest results of the use of Convolutional Neural Network, the proposed work aims at optimizing the results of the grasping tasks to make it reliable for an industrial use. Limitations are analyzed and new parameters are defined in order to make the manipulation task repeatable in terms of robot grasp position. In fact, in an automated production line, this is an important problem to consider because in many situations the object has to be positioned always in the same position with the same orientation
The value of alkaline phosphatase isoenzyme determinations in patients undergoing periodic haemodialysis [VALORE DELLA DETERMINAZIONE DEGLI ISOENZIMI DELLA FOSFATASI ALCALINA NEI PAZIENTI IN TRATTAMENTO EMODIALITICA PERIODICO]
No full textAlkaline phosphatase is frequently increased in patients treated with hemodialysis. This enzyme is connected with cellular structures and therefore there is no organ specificity. Isoenzymatic activity is a more accurate test for a specific organ. Four fractions have been separated inside alkaline phosphatase using an electrophoretic method on cellulose acetate: ALP 1 (biliary), ALP 2 (bone and hepatic), ALP 3 (intestinal, placentar and Regan), ALP 4 (fibroblastic). Studied are 28 patients on regular dialysis treatment: 14 had normal levels of alkaline phosphatase; 14 had increased levels. The analysis of the tracing and the thermostability tests have shown pathological bands in both groups of patients. It seems that the investigation of the fractions of alkaline phosphatase is a valid test for the study of specific organ pathology
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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