GeAs as an emerging p-type van der Waals semiconductor and its application in p-n photodiodes.

van der Waals (vdW) layered materials have shown great potential for future optoelectronic applications owing to their unique and variable properties. In particular, two-dimensional layered materials enable the creation of various circuital building blocks via vertical stacking, e.g. the vertical p-n junction as a key one. While numerous stable n-type layered materials have been discovered, p-type materials remain relatively scarce. Here, we report on the study of multilayer germanium arsenide (GeAs), another emerging p-type vdW layered material. We first verify the efficient hole transport in a multilayer GeAs field-effect transistor with Pt electrodes, which establish low contact potential barriers. Subsequently, we demonstrate a p-n photodiode featuring a vertical heterojunction of a multilayer GeAs and n-type MoS2monolayer, exhibiting a photovoltaic response. This study promotes that 2D GeAs is a promising candidate for p-type material in vdW optoelectronic devices.

Effectiveness of a novel semi-closed barrier device with a personalized exhaust in cough aerosol simulation according to particle counts and visualization of particles.

Oxygen therapy is an essential treatment for patients with coronavirus disease 2019, although there is a risk of aerosolization of additional viral droplets occurring during this treatment that poses a danger to healthcare professionals. High-flow oxygen through nasal cannula (HFNC) is a vital treatment bridging low-flow oxygen therapy with tracheal intubation. Although many barrier devices (including devices without negative pressure in the barrier) have been reported in the literature, few barrier devices are suitable for HFNC and aerosol infection control procedures during HFNC have not yet been established. Hence, we built a single cough simulator model to examine the effectiveness of three protective measures (a semi-closed barrier device, a personalized exhaust, and surgical masks) administered in isolation as well as in combination using particle counter measurements and laser sheet visualization. We found that the addition of a personalized exhaust to a semi-closed barrier device reduced aerosol leakage during HFNC without negative pressure. This novel combination may thus reduce aerosol exposure during oxygen therapy, enhance the protection of healthcare workers, and likely reduce nosocomial infection risk.

Effect of two barrier devices on the time taken and ease of intubation of a paediatric intubation manikin - A randomised cross-over simulation study.

Background and Aims: During the present COVID-19 pandemic, several inventions have been employed to protect personnel involved in intubation from inhalational exposure to the virus. In this study, we compared the effect of two barrier devices, Intubation Box versus Plastic Drape, on the time taken and difficulty in intubating a pediatric manikin. Material and Methods: Nineteen experienced anesthesiologists performed six different intubations: without barrier, with intubation box, with plastic drape; with and without a bougie, using the Latin Square Design for randomizing order of intubations. The time taken for intubation (TTI) was compared using Student's t test, and nonparametric values were analyzed using Chi-square test with Yates correction. Results: Both barrier devices increased the TTI from 14.8 (3.5) s to 19.8 (6.8) s with intubation box (P = 0.068) and 19.3 (8.9) s with plastic drape (P = 0.099). Use of bougie significantly prolonged TTI to 25.8 (6.7) s without barrier (P = 0.000), 32.5 (13.3) with intubation box (P = 0.000), and 29.8 (7.3) s with plastic drape (P = 0.000). The number of attempts was not different (P = 0.411), and the visibility was slightly impaired with both barriers (P = 0.047). The ease of intubation, even without the bougie, was significantly different compared to default, with P values of 0.009 and 0.042 for intubation box and plastic drape, respectively. The highest significance was with intubation box with bougie with a P value of 0.00017. Conclusion: Both the intubation box and plastic drape increased the time taken as well as difficulty in intubation. The extra protection afforded should be balanced against risks of hypoxia in the patient.

Initial Outcomes of a Novel Irrigating Wound Protector for Reducing the Risk of Surgical Site Infection in Elective Colectomies.

BACKGROUND: Surgical site infection (SSI) rates in elective colorectal surgery remain high due to intraoperative exposure of colonic bacteria at the surgical site. We aimed to evaluate 30-day SSI outcomes of a novel wound retractor that combines barrier protection with continuous wound irrigation in elective colorectal resection. MATERIALS AND METHODS: A retrospective single-center cohort-matched analysis included all patients undergoing elective colorectal resection utilizing the novel irrigating wound protector (IWP) from April 2015 to July 2019. A control cohort of patients who underwent the same procedures with a standard wound protector over the same time period were also identified. Patients from both groups were matched for procedure type, procedure approach, pathology requiring operation, age, sex, race, body mass index, diabetes, smoker status, hypertension, presence of disseminated cancer, current steroid or immunosuppressant use, wound classification, and American Society of Anesthesiologist classification. SSI frequency, SSI subtype (superficial, deep, or organ space), hospital length of stay (LOS) and associated procedure were tabulated through 30 postoperative days. Fisher's exact test and number needed to treat (NNT) were used to compare SSI rates and estimate cost between both groups. RESULTS: The IWP group had 41 patients. The control group had 82 patients. Control-matched variables were similar for both groups. 30-day SSI rates were significantly lower in the IWP group (P=0.0298). length of stay was significantly shorter in the IWP group (P=0.0150). The NNT for the IWP to prevent one episode of SSI was 8.2 patients. CONCLUSIONS: The novel IWP device shows promise to reducing the risk of SSI in elective colorectal surgery.

The aerosol box for intubation in coronavirus disease 2019 patients: an in-situ simulation crossover study.

The coronavirus disease 2019 pandemic has led to the manufacturing of novel devices to protect clinicians from the risk of transmission, including the aerosol box for use during tracheal intubation. We evaluated the impact of two aerosol boxes (an early-generation box and a latest-generation box) on intubations in patients with severe coronavirus disease 2019 with an in-situ simulation crossover study. The simulated process complied with the Safe Airway Society coronavirus disease 2019 airway management guidelines. The primary outcome was intubation time; secondary outcomes included first-pass success and breaches to personal protective equipment. All intubations were performed by specialist (consultant) anaesthetists and video recorded. Twelve anaesthetists performed 36 intubations. Intubation time with no aerosol box was significantly shorter than with the early-generation box (median (IQR [range]) 42.9 (32.9-46.9 [30.9-57.6])s vs. 82.1 (45.1-98.3 [30.8-180.0])s p = 0.002) and the latest-generation box (52.4 (43.1-70.3 [35.7-169.2])s, p = 0.008). No intubations without a box took more than 1 min, whereas 14 (58%) intubations with a box took over 1 min and 4 (17%) took over 2 min (including one failure). Without an aerosol box, all anaesthetists obtained first-pass success. With the early-generation and latest-generation boxes, 9 (75%) and 10 (83%) participants obtained first-pass success, respectively. One breach of personal protective equipment occurred using the early-generation box and seven breaches occurred using the latest-generation box. Aerosol boxes may increase intubation times and therefore expose patients to the risk of hypoxia. They may cause damage to conventional personal protective equipment and therefore place clinicians at risk of infection. Further research is required before these devices can be considered safe for clinical use.

Measurement of airborne particle exposure during simulated tracheal intubation using various proposed aerosol containment devices during the COVID-19 pandemic.

The COVID-19 pandemic has led to the production of novel devices intended to protect airway managers during the aerosol-generating procedure of tracheal intubation. Using an in-situ simulation model, we evaluated laryngoscopist exposure of airborne particles sized 0.3 - 5.0 microns using five aerosol containment devices (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no aerosol containment device. Nebulised saline was used as the aerosol-generating model for 300 s, at which point, the devices were removed to assess particle spread. Primary outcome was the quantity and size of airborne particles measured at the level of the laryngoscopist's head at 30, 60, 120 and 300 s, as well as 360 s (60 s after device removal). Airborne particles sizes of 0.3, 0.5, 1.0, 2.5 and 5.0 microns were quantified using an electronic airborne particle counter. Compared with no device use, the sealed intubation box with suction resulted in a decrease in 0.3, 0.5, 1.0 and 2.5 micron, but not 5.0 micron, particle exposure over all time-periods (p = 0.003 for all time periods). Compared with no device use, the aerosol box showed an increase in 1.0, 2.5 and 5.0 micron airborne particle exposure at 300 s (p = 0.002, 0.008, 0.002, respectively). Compared with no device use, neither horizontal nor vertical drapes showed any difference in any particle size exposure at any time. Finally, when the patient coughed, use of the aerosol box resulted in a marked increase in airborne particle exposure compared with other devices or no device use. In conclusion, novel devices intended to protect the laryngoscopist require objective testing to ensure they are fit for purpose and do not result in increased airborne particle exposure.

Mitigating the spread of COVID-19 during extubation: Assessing the impact of a barrier device.

COVID-19 is a novel virus spread via airborne particles. Given the inherent risk to the anesthesia provider, intubation and airway management guidelines have been recently established. Various studies have been published advocating and detailing the results of different intubation devices designed to decrease the number of airborne particles. Currently, little literature exists regarding devices designed to mitigate the spread of COVID-19 airborne particles during extubation. The purpose of this prospective in situ simulated manikin study was to measure the effectiveness of an aerosolized containment device during passive (deep) and forced (simulated coughing) extubation. Airborne particles were measured at the 0.3, 0.5, 1, 2, 5, 10-micron level. Statistically significant decreases were seen with the use of a barrier device during both passive and forced extubation.

Effectiveness of "Resuscitation Cover All" in Minimizing COVID-19 Transmission to Health-Care Workers during Cardiopulmonary Resuscitation.

Introduction: Coronavirus disease 2019 (COVID-19) is a highly contagious disease transmitted by contact, droplets, and aerosols. Front line health-care workers (HCWs), particularly emergency physicians and acute care providers, are vulnerable to being exposed while treating their sick patients. Despite appropriate personal protective equipment use, HCW gets infected, suggesting the need for multiple layers of protection such as barrier devices. Methods: We aimed to determine the effectiveness of our novel "Resuscitation Cover All"(RCA) in reducing the exposure of HCW to simulated respiratory particles and its feasibility during cardio pulmonary resuscitation (CPR). This was a pilot simulation-based study. Five CPR simulation sessions were performed in Standard and RCA protocols, individually. Exposures through contact, droplets, and aerosols were simulated using a standardized volume of liquid detergent. Under Wood's lamp illumination, exposures of participants were compared between the protocols. Rate and depth of chest compressions, time taken to intubate, interruptions in CPR, and first-pass success were analyzed. Results: Overall mean exposure in standard protocol was 4950.4 ± 1461.6 (95%confidence interval [CI]:3135.7-6765.2) sq.pixels and RCA protocol was 2203.6 ± 1499.0 (95%CI: 342.4-4064.9) sq.pixels (P = 0.019). In standard, chest compressor had the highest exposure of 3066.6 ± 1419.2 (95%CI: 2051.3-4081.9) sq.pixels followed by defibrillator assistant 1166.4 ± 767.4 (95%CI: 617.4-1715.4) sq.pixels. Chest compressor of RCA had reduced exposure compared to that of standard (P < 0.001). Hands were the most frequently exposed body part. Airway manager of RCA had no exposure over head and neck in any session. No significant difference in CPR performance metrics was observed. Conclusion: This pilot simulation-based study shows that the novel RCA device could minimize the exposure of HCW to simulated respiratory particles during CPR. Also, it might not alter the high-quality CPR performance metrics. We need more real-life evidence.

Video Laryngoscope Intubation With an Aerosol Barrier Device: A Randomized Sequential Crossover Pilot Study.

OBJECTIVES: To assess the impact of the use of aerosol barrier device, Splashguard-CG, on the endotracheal intubation with different types of laryngoscope. DESIGN: A pilot randomized sequential crossover simulation study. SETTING: A single academic center in Japan. SUBJECTS: Physicians in a single academic university hospital in Japan. INTERVENTIONS: Use of Splashguard-CG. MEASUREMENTS AND MAIN RESULTS: All participants were asked to perform endotracheal intubation to a manikin simulator using three different devices (Macintosh laryngoscope; Airway Scope [Nihon Kohden, Tokyo, Japan]; and McGRATH MAC [Aircraft Medical, Edinburgh, United Kingdom]) with and without Splashguard-CG in place, which required a total of six attempts and measured the intubation time as the primary outcome. Thirty physicians (15 experienced physicians and 15 less-experienced physicians) were included. Intubation time using Macintosh laryngoscope was significantly longer in the group with Macintosh laryngoscope and Splashguard-CG compared with the group without Splashguard-CG by the median difference of 4.3 seconds (interquartile range, 2.6-7.4 s; p < 0.001). There was no significant increase in the intubation time with or without Splashguard-CG for the Airway Scope (0.6 s; interquartile range, -3.7 to 3.2 s; p = 0.97) and the McGRATH MAC (0.5 s; interquartile range, -1.4 to 4.6 s; p = 0.09). This trend was found in both the experienced and less-experienced groups. We observed significant increases of subjective difficulty of the endotracheal intubation evaluated by using a Visual Analog Scale in the Splashguard-CG groups for all three types of devices. CONCLUSIONS: The use of a video laryngoscope with an aerosol barrier device does not impact the time required endotracheal intubation in a simulation environment. This method can be considered as airway management for coronavirus disease 2019.