Risk of ventricular tachycardia and its outcomes in patients undergoing continuous renal replacement therapy due to acute kidney injury

Background Despite efforts to treat critically ill patients who require continuous renal replacement therapy (CRRT) due to acute kidney injury (AKI), their mortality risk remains high. This condition may be attributable to complications of CRRT, such as arrhythmias. Here, we addressed the occurrence of ventricular tachycardia (VT) during CRRT and its relationship with patient outcomes. Methods This study retrospectively enrolled 2,397 patients who started CRRT due to AKI from 2010 to 2020 at Seoul National University Hospital in Korea. The occurrence of VT was evaluated from the initiation of CRRT until weaning from CRRT. The odds ratios (ORs) of mortality outcomes were measured using logistic regression models after adjustment for multiple variables. Results VT occurred in 150 patients (6.3%) after starting CRRT. Among them, 95 cases were defined as sustained VT (i.e., lasting ≥30 seconds), and the other 55 cases were defined as non-sustained VT (i.e., lasting <30 seconds). The occurrence of sustained VT was associated with a higher mortality rate than a nonoccurrence (OR, 2.04 and 95% confidence interval [CI], 1.23–3.39 for the 30-day mortality; OR, 4.06 and 95% CI, 2.04–8.08 for the 90-day mortality). The mortality risk did not differ between patients with non-sustained VT and nonoccurrence. A history of myocardial infarction, vasopressor use, and certain trends of blood laboratory findings (such as acidosis and hyperkalemia) were associated with the subsequent risk of sustained VT. Conclusion Sustained VT occurrence after starting CRRT is associated with increased patient mortality. The monitoring of electrolytes and acid-base status during CRRT is essential because of its relationship with the risk of VT

Dependency of Vapor-Deposited a-SiC Film Quality on the Substrate Temperatures

The dramatic variations in structure and internal stress in an amorphous silicon carbide film (a-SiC) induced by forming process have been reported extensively. Vapor-depositions of a-SiC film were simulated by molecular dynamics simulation employing the Tersoff potential. To understand effect of substrate temperature that is one of the most important factors involved in the changes in structure and intrinsic stress, the vapor-depositions at various substrate temperatures (500-2500 K) were performed. Then, the MD simulations of cooling to 298 K were carried out. For both cooled and as-deposited a-SiC films, the analyses of structure and internal stress with deposition process parameters entailed the calculation of density, chemical order, and in-plane stress [(??_(xx)+??_(yy))/2].clos

5G-AKA-FS: A 5G Authentication and Key Agreement Protocol for Forward Secrecy

5G acts as a highway enabling innovative digital transformation and the Fourth Industrial Revolution in our lives. It is undeniable that the success of such a paradigm shift hinges on robust security measures. Foremost among these is primary authentication, the initial step in securing access to 5G network environments. For the 5G primary authentication, two protocols, namely 5G Authentication and Key Agreement (5G-AKA) and Improved Extensible Authentication Protocol Method for 3rd Generation Authentication and Key Agreement (EAP-AKA′), were proposed and standardized, where the former is for 3GPP devices, and the latter is for non-3GPP devices. Recent scrutiny has unveiled vulnerabilities in the 5G-AKA protocol, exposing it to security breaches, including linkability attacks. Moreover, mobile communication technologies are dramatically evolving while 3GPP has standardized Authentication and Key Management for Applications (AKMA) to reuse the credentials, generated during primary authentication, for 5G network applications. That makes it so significant for 5G-AKA to be improved to support forward secrecy as well as address security attacks. In response, several protocols have been proposed to mitigate these security challenges. In particular, they tried to strengthen security by reusing secret keys negotiated through the Elliptic Curve Integrated Encryption Scheme (ECIES) and countering linkability attacks. However, they still have encountered limitations in completing forward secrecy. Motivated by this, we propose an augmentation to 5G-AKA to achieve forward security and thwart linkability attacks (called 5G-AKA-FS). In 5G-AKA-FS, the home network (HN), instead of using its static ECIES key pair, generates a new ephemeral key pair to facilitate robust session key negotiation, truly realizing forward security. In order to thoroughly and precisely prove that 5G-AKA-FS is secure, formal security verification is performed by applying both BAN Logic and ProVerif. As a result, it is demonstrated that 5G-AKA-FS is valid. Besides, our performance comparison highlights that the communication and computation overheads are intrinsic to 5G-AKA-FS. This comprehensive analysis showcases how the protocol effectively balances between security and efficiency

APSec1.0: Innovative Security Protocol Design with Formal Security Analysis for the Artificial Pancreas System

The Medical Internet-of-Things (MIoT) has developed revolutionary ways of delivering medical care to patients. An example system, showing increasing demand, is the artificial pancreas system that offers convenience and reliable support care to patients with Type 1 Diabetes. Despite the apparent benefits, the system cannot escape potential cyber threats that may worsen a patient’s condition. The security risks need immediate attention to ensure the privacy of the patient and preserve safe functionality. Motivated by this, we proposed a security protocol for the APS environment wherein support to essential security requirements is guaranteed, the security context negotiation is resource-friendly, and the protocol is resilient to emergencies. Accordingly, the security requirements and correctness of the design protocol were formally verified using BAN logic and AVISPA, and proved its feasibility through the emulation of APS in a controlled environment using commercial off-the-shelf devices. Moreover, the results of our performance analysis indicate that the proposed protocol is more efficient than the other existing works and standards

Implementation of CNN-Based Parking Slot Type Classification using Around View Images

This paper presents a commercial implementation of CNN-based classification of parking slot type using around view images. The existing automatic parking systems use ultrasonic sensors, but they often fail to classify the types of parking slots. Around view images can depict the types of parking slots distinguishably. However, due to the diverse lighting and ground conditions, it is difficult to classify the parking slot type using images. Moreover, it is hard to find the parking lines since the lines are often occluded by vehicle or erased. To overcome these problems, we have constructed an extensive dataset composed of labeled 480,000 images acquired on various environments using around view monitoring (AVM) camera mounted on a commercial vehicle. For training our CNN-based classifier, we subdivided parking slot types into ten categories and finally derived three parking slot types for actual applications. To operate the classifier in real vehicles, we designed CNN model suitable to embedded systems and implemented it using GPU. In experimental evaluation, the implemented CNN-based classifier achieves an accuracy of 94.15 A. And the processing time of our classifier achieves 3.67ms per frame (270 fps) on the NVIDIA Tegra CX embedded system.N

Thoracoscopic surgery under epidural anesthesia for intractable secondary spontaneous pneumothorax

Objective: Surgical intervention might be required in secondary spontaneous pneumothorax (SSP) with prolonged air leak; however, operation under general anesthesia (GA) could be critical in compromised patients. In this study, we performed video-assisted thoracic surgery (VATS) under epidural anesthesia (EA) in compromised patients with SSP and evaluated its feasibility. Methods: Of 212 patients who underwent VATS for SSP, 179 patients had surgery under GA and 33 under EA from 2006 to 2014. All medical records were retrospectively reviewed for operative time, pre- and postoperative chest tube drainage, postoperative complications, and hospital death. To evaluate the efficacy of VATS under EA, these factors were compared between EA and GA groups. Results: The mean operative time and the mean duration of postoperative drainage, respectively was 106.2±45.3 minutes and 6.15±10.51 days in GA, and 102.6±43.1 minutes and 6.10±7.20 days in EA. Of 18 cases with recurrence and 13 cases with complications, only one recurrence and one complication developed in EA. Conclusion: In case with patients having intractable SSP with compromised pulmonary function, VATS under EA could be an effective and safe option to approach the appropriate goals of air leak control and less recurrence of pneumothorax

Role of microalloyed Sm in enhancing the corrosion resistance of hot-rolled Mg???8Sn???1Al???1Zn alloy

We report that the corrosion resistance of hot-rolled Mg?8Sn?1Al?1Zn alloy was significantly enhanced by Sm microalloying. Corrosion rates, measured after immersion for 72 h in 0.6 M NaCl solution, were found to be 2.7 and 19 mm y-1 for the alloys with and without an addition of 0.02 wt% Sm, respectively. Electrochemical and microstructural analyses revealed that the enhanced corrosion resistance achieved by Sm microalloying is mainly a result of a reduced H2 evolution rate owing to the presence of Al8Fe4Sm particles instead of nobler Al5Fe2 particles, which highly accelerate microgalvanic corrosion in the alloy without Sm microalloying

Vapor Transport Synthesis of Two-Dimensional SnS2 Nanocrystals Using a SnS2 Precursor Obtained from the Sulfurization of SnO2

Manufacturing high-quality, two-dimensional (2D), layered materials with crystal-growth techniques is an important challenge for the advancement of 2D communication technologies. In this study, a simple method was developed for synthesizing 2D nanocrystals based on the model system of SnS2. The method involves the sulfurization of a metal oxide to a metal chalcogenide, which subsequently acts as a source of vapors for the growth of 2D crystals. The effect of the annealing conditions on the thermal sulfurization of SnO2 powder was investigated. The results showed that pure SnS2 powder could be obtained in a N2 atmosphere at 700 °C. SnS2 nanocrystals were successfully synthesized from the as-prepared SnS2 powder by the vapor transport method. The synthesized SnS2 nanocrystals had a 2D layered structure with hexagonal symmetry and exhibited typical n-type semiconducting characteristics, with an optical band gap of 2.05 eV. This novel method, which uses a preferentially prepared source for vapor transport, could provide a simple way to synthesize new types of 2D layered materials. This is because it only requires the volatilization of a source and subsequent condensation to a single crystal for the growth of 2D materials, with no complex chemical reactions occurring during vapor transport. © 2016 American Chemical Society.

Role of trace additions of Mn and Y in improving the corrosion resistance of Mg???3Al???1Zn alloy

The corrosion resistance of conventional and experimental Mg-3Al-1Zn-based alloys with different Mn and Y content was comparatively investigated. After immersion for 72 h in a 0.6 M NaCl solution at 25 degrees C, an experimental Mg-3Al-1Zn-0.05Mn-0.03Y alloy exhibited a corrosion rate of 0.91 mm y(-1), which is about four times slower than that of a conventional Mg-3Al-1Zn-0.3Mn alloy. Microstructural factors underlying the improved corrosion resistance achieved by the trace additions of Mn and Y are discussed