Use of amplitude-integrated electroencephalography in decision-making for extracorporeal membrane oxygenation in comatose cardiac arrest patients whose eventual neurologic recovery is uncertain

Comatose cardiac arrest patients frequently experience cardiogenic shock or recurrent arrest. Extracorporeal membrane oxygenation (ECMO) can be used to salvage patients with cardiogenic shock or cardiac arrest refractory to conventional therapies. However, in comatose cardiac arrest patients whose neurologic recovery is uncertain, the use of ECMO is restricted because it requires considerable financial and human resources. Amplitude-integrated electroencephalography is an easily applicable, real-time electroencephalography monitoring tool that has been increasingly used to monitor brain activity in comatose cardiac arrest patients. We describe our experience of using amplitude-integrated electroencephalography in decision-making to place ECMO for comatose cardiac arrest patients whose eventual neurologic recovery appeared uncertain at the time of ECMO placement

Optimal Design of a Centrifugal Compressor Impeller Using Evolutionary Algorithms

An optimization study was conducted on a centrifugal compressor. Eight design variables were chosen from the control points for the Bezier curves which widely influenced the geometric variation; four design variables were selected to optimize the flow passage between the hub and the shroud, and other four design variables were used to improve the performance of the impeller blade. As an optimization algorithm, an artificial neural network (ANN) was adopted. Initially, the design of experiments was applied to set up the initial data space of the ANN, which was improved during the optimization process using a genetic algorithm. If a result of the ANN reached a higher level, that result was re-calculated by computational fluid dynamics (CFD) and was applied to develop a new ANN. The prediction difference between the ANN and CFD was consequently less than 1% after the 6th generation. Using this optimization technique, the computational time for the optimization was greatly reduced and the accuracy of the optimization algorithm was increased. The efficiency was improved by 1.4% without losing the pressure ratio, and Pareto-optimal solutions of the efficiency versus the pressure ratio were obtained through the 21st generation

Bond strength of experimental cyanoacrylate-modified dental glass ionomer cements

Abstract Glass ionomer cement (GIC) has been successfully used in dental field for more than 40 years. Despite numerous advantages of GIC, low bond strength and slow setting rate limited conventional GICs for use only at low stress-bearing areas. To improve bond strength to tooth, two kinds of cyanoacrylates such as ethyl 2-cyanoacrylate (EC) and allyl 2-cyanoacrylate (AC) were added in a commercial GIC. Changes in setting time of cyanoacrylate-modified GICs (CMGICs) according to the concentration of cyanoacrylates and/or p-toluene sulfonic acid (TSA) was investigated using a rheometer. Shear bond strength to human dentin was measured. Biocompatibility was determined by the viability of fibroblasts. Optimal concentrations for EC and TSA were 5-10% of the GIC powder and 30% of the GIC liquid, respectively. EC-based CMGIC showed twofold increase of initial bond strength compared with conventional GIC. Also, AC-based CMGIC showed three times higher bond strength and similar biocompatibility compared with the GIC. Therefore, CMGIC materials can be widely applied in dental adhesive restoration field because they showed improved bond strength and proper setting time

Symplectic Embedding of a Massive Vector-Tensor Theory with Topological Coupling

In the symplectic Lagrangian framework we newly embed an irreducible massive vector-tensor theory into a gauge invariant system, which has become reducible, by extending the configuration space to include an additional pair of scalar and vector fields, which give the desired Wess-Zumino action. A comparision with the BFT Hamiltonian embedding approach is also done.Comment: LaTeX file, 23 page

Aggression and Harm-Avoidant Trait Impede Recovery From Internet Gaming Disorder

Background: Relatively little is known about which neuropsychological factors promote recovery from Internet gaming disorder (IGD).Methods: With informed consents, a cohort study was conducted in Seoul metropolitan area, South Korea, to investigate the course of IGD in youths. At baseline, we assessed psychosocial measures and gaming related measures such as Young's Internet Addiction Test (IAT) and the Aggression Questionnaire. The Balloon Analog Risk Task was also performed to study risk-taking behavior. A total of 60 subjects demonstrating three or greater criteria in the diagnostic interviews on IGD and the IAT score of 50 or above were included. After brief parental coaching at baseline, the participants were followed up at 3 and 6 months (n = 31). The baseline characteristics were compared between the non-improved group (<10% improvement in IAT score) and the improved group (≥30% improvement in IAT score) using Mann-Whitney U-test or chi-squared tests with a two-tailed statistical significance of 0.05.Results: The non-improved group and the improved group did not demonstrate significant differences regarding demographics or the IAT scores at baseline. However, the IAT scores were significantly higher in the non-improved group at both 3 and 6 months. The non-improved group was also more likely to display higher aggression and harm avoidance than the improved group at baseline.Discussion: Youths with excessive gaming problems should be evaluated for aggression and harm avoidance since they contributed to a worse prognosis. For those with high aggression or harm avoidance, more active therapeutic interventions should be considered

Effect of pralidoxime on coronary perfusion pressure during cardiopulmonary resuscitation in a pig model

Objective Pralidoxime is widely used for the treatment of organophosphate poisoning. Multiple studies have reported its vasoconstrictive property, which may facilitate the restoration of spontaneous circulation (ROSC) after cardiac arrest by increasing the coronary perfusion pressure (CPP). 2,3-Butanedione monoxime, which belongs to the same oxime family, has been shown to facilitate ROSC by reducing left ventricular ischemic contracture. Because pralidoxime and 2,3-butanedione monoxime have several common mechanisms of action, both drugs may have similar effects on ischemic contracture. Thus, we investigated the effects of pralidoxime administration during cardiopulmonary resuscitation in a pig model with a focus on ischemic contracture and CPP. Methods After 14 minutes of untreated ventricular fibrillation, followed by 8 minutes of basic life support, 16 pigs randomly received either 80 mg/kg of pralidoxime (pralidoxime group) or an equivalent volume of saline (control group) during advanced cardiovascular life support (ACLS). Results Mixed-model analyses of left ventricular wall thickness and chamber area during ACLS revealed no significant group effects or group-time interactions, whereas a mixed-model analysis of the CPP during ACLS revealed a significant group effect (P=0.038) and group-time interaction (P<0.001). Post-hoc analyses revealed significant increases in CPP in the pralidoxime group, starting at 5 minutes after pralidoxime administration. No animal, except one in the pralidoxime group, achieved ROSC; thus, the rate of ROSC did not differ between the two groups. Conclusion In a pig model of cardiac arrest, pralidoxime administered during cardiopulmonary resuscitation did not reduce ischemic contracture; however, it significantly improved CPP

A Retrospective CT Analysis for Prelacrimal Window Access to Maxillary Sinus

Background and Objectives The prelacrimal window approach (PLWA) is useful for treating anterior maxillary sinus lesions. A previous study reported that the feasibility of PLWA in Chinese patients was 93.0%, which is higher than that in the European population (68.5%). This study aimed to compare the ease of PLWA between a patient group and healthy controls and to analyze the results for Koreans compared to those of previous studies. Differences between the patient and control groups and the distribution of types in the Korean population were evaluated. Methods We analyzed 89 paranasal computed tomography (CT) scans from 51 controls and 38 patients (178 sides). We measured the distance distribution between the anterior wall of the maxillary sinus and the anterior wall of the lacrimal duct (D1) and its thickness (T). We compared the values in the control and patient groups. Results D1 and D2 were similar between the patient and control groups (p=0.395, p=0.344), though T was greater in the patient group (p<0.001). In the patient group, sinus with inverted papilloma (IP) and normal sinus were not significantly different for any of these measures. The D1 distribution in Koreans did not differ significantly from that of Chinese but did differ from that of Europeans. Conclusion The ease of PLWA was 92.2% in Koreans, which is more similar to that of Chinese (93.0%) than to that of Europeans (68.5%). D1 and D2 of the patient group did not differ from those of the control group, but T was greater in the patient group. In the patient group, D1 and D2 were not significantly different between sinus with IP and normal sinus. The frequency of type 2+3 in patients was similar to that of the control group