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Strain engineering provides an attractive approach to enhance device performance by modulating the intrinsic electrical properties of materials. This is especially applicable to 2D materials, which exhibit high sensitivity to mechanical stress. However, conventional methods, such as using polymer substrates, to apply strain have limitations in that the strain is temporary and global. Here, we introduce a novel approach to induce permanent localized strain by fabricating a stressor on SiO2/Si substrates using fiber laser irradiation, thereby enabling precise control of the surface topography. MoS2 is transferred onto this stressor, which results in the application of ~0.8% tensile strain. To assess the impact of the internal strain on the operation of ReRAM devices, the flat-MoS2-based and the strained-MoS2-based devices are compared. Both devices demonstrate forming-free, bipolar, and non-volatile switching characteristics. The strained devices exhibit a 30% reduction in the operating voltage, which can be attributed to bandgap narrowing and enhanced carrier mobility. Furthermore, the strained devices exhibit nearly a two-fold improvement in endurance, presumably because of the enhanced stability from lattice release effect. These results emphasize the potential of strain engineering for advancing the performance and durability of next-generation memory devices. [ABSTRACT FROM AUTHOR]

Background: Cervical epidural block (CEB) is an effective intervention for managing cervical radicular pain. This study aimed to investigate the current status of performing CEB in South Korea., Methods: Pain physicians affiliated with the Korean Pain Society were asked to complete anonymous questionnaires regarding CEB between September and October 2022. The questionnaire consisted of 24 questions assessing the current status and methods of CEB in detail., Results: Of the 198 surveys collected, 171 physicians (86.4%) reported performing CEB. Among those, the majority (94.7%) used fluoroscopy during the procedure. The paramedian interlaminar (IL) approach was the most preferred method (50.3%). Respondents performing fluoroscopic-guided IL CEB were categorized into two groups based on clinical experience: those with ≤10 years of experience (≤10-year group, n = 91) and those with >10 years of experience (>10-year group, n = 71). The proportion of physicians obtaining informed consent in the ≤10-year group and >10-year group was 50.5% and 56.3%, respectively. When entering the epidural space during IL CEB, the contralateral oblique view was the second most frequently used in both groups (≤10-year group, 42.9%; >10-year group, 29.6%). In targeting the upper cervical lesions (C3-4), the proportion of respondents who used an IL space higher than C6-7 was 17.6% in the ≤10-year group and 29.5% in the >10-year experience group., Conclusions: This study demonstrated variability in the CEB technique used by pain physicians in South Korea. The findings highlight the need for education on informed consent and techniques to enhance safety.

Background: Although preoxygenation is an essential procedure for safe endotracheal intubation, in some cases securing sufficient time for tracheal intubation may not be possible. Patients with head and neck cancer might have a difficult airway and need a longer time for endotracheal intubation. We hypothesized that the extended apneic period with preoxygenation via a high-flow nasal cannula (HFNC) is beneficial to patients who undergo head and neck surgery compared with preoxygenation with a simple mask., Methods: The study was conducted as a single-center, single-blinded, prospective, randomized controlled trial. Patients were divided into groups based on one of the two preoxygenation., Methods: HFNC group or simple facemask (mask group). Preoxygenation was performed for 5 minutes with each method, and endotracheal intubation for all patients was performed using a video laryngoscope. Oxygen partial pressures of the arterial blood were compared at the predefined time points., Results: For the primary outcome, the mean arterial oxygen partial pressure (PaO2 ) immediately after intubation was 454.2 mm Hg (95% confidence interval [CI], 416.9-491.5 mm Hg) in the HFNC group and 370.7 mm Hg (95% CI, 333.7-407.4 mm Hg) in the mask group (P=0.002). The peak PaO2 at 5 minutes after preoxygenation was not statistically different between the groups (P=0.355)., Conclusions: Preoxygenation with a HFNC extending to the apneic period before endotracheal intubation may be beneficial in patients with head and neck cancer.