Gate-tunable Veselago interference in a bipolar graphene microcavity.

The relativistic charge carriers in monolayer graphene can be manipulated in manners akin to conventional optics. Klein tunneling and Veselago lensing have been previously demonstrated in ballistic graphene pn-junction devices, but collimation and focusing efficiency remains relatively low, preventing realization of advanced quantum devices and controlled quantum interference. Here, we present a graphene microcavity defined by carefully-engineered local strain and electrostatic fields. Electrons are manipulated to form an interference path inside the cavity at zero magnetic field via consecutive Veselago refractions. The observation of unique Veselago interference peaks via transport measurement and their magnetic field dependence agrees with the theoretical expectation. We further utilize Veselago interference to demonstrate localization of uncollimated electrons and thus improvement in collimation efficiency. Our work sheds new light on relativistic single-particle physics and provide a new device concept toward next-generation quantum devices based on manipulation of ballistic electron trajectory.

Correlated Insulating States and Transport Signature of Superconductivity in Twisted Trilayer Graphene Superlattices.

Layers of two-dimensional materials stacked with a small twist angle give rise to beating periodic patterns on a scale much larger than the original lattice, referred to as a "moiré superlattice." Here, we demonstrate a higher-order "moiré of moiré" superlattice in twisted trilayer graphene with two consecutive small twist angles. We report correlated insulating states near the half filling of the moiré of moiré superlattice at an extremely low carrier density (∼10^{10} cm^{-2}), near which we also report a zero-resistance transport behavior typically expected in a 2D superconductor. The full-occupancy (ν=-4 and ν=4) states are semimetallic and gapless, distinct from the twisted bilayer systems.

BKCa Channel Inhibition by Peripheral Nerve Injury Is Restored by the Xanthine Derivative KMUP-1 in Dorsal Root Ganglia.

This study explored whether KMUP-1 improved chronic constriction injury (CCI)-induced BKCa current inhibition in dorsal root ganglion (DRG) neurons. Rats were randomly assigned to four groups: sham, sham + KMUP-1, CCI, and CCI + KMUP-1 (5 mg/kg/day, i.p.). DRG neuronal cells (L4-L6) were isolated on day 7 after CCI surgery. Perforated patch-clamp and inside-out recordings were used to monitor BKCa currents and channel activities, respectively, in the DRG neurons. Additionally, DRG neurons were immunostained with anti-NeuN, anti-NF200 and anti-BKCa. Real-time PCR was used to measure BKCa mRNA levels. In perforated patch-clamp recordings, CCI-mediated nerve injury inhibited BKCa currents in DRG neurons compared with the sham group, whereas KMUP-1 prevented this effect. CCI also decreased BKCa channel activity, which was recovered by KMUP-1 administration. Immunofluorescent staining further demonstrated that CCI reduced BKCa-channel proteins, and KMUP-1 reversed this. KMUP-1 also changed CCI-reduced BKCa mRNA levels. KMUP-1 prevented CCI-induced neuropathic pain and BKCa current inhibition in a peripheral nerve injury model, suggesting that KMUP-1 could be a potential agent for controlling neuropathic pain.

Assessing the quality of CPR performed by a single lifeguard, two lifeguards and a lifeguard with a bystander after water rescue: a quasi-experimental trial.

BACKGROUND: High-quality cardiopulmonary resuscitation (CPR) could improve survival of drowning victims. The purpose of the study is to assess the impact of fatigue caused by water rescue on subsequent CPR quality and the influence of a bystander's participation on CPR quality in a lifeguard rescue. METHODS: This was a simulated quasi-experimental study with a sample of 14 lifeguards and 13 laypersons. Each lifeguard performed 2 min single-rescuer CPR as baseline measurement. In three separate trials, a single lifeguard swam 50 m to perform a water rescue in a pool and returned with the manikin another 50 m. After each rescue, 10 min of CPR was performed by a single lifeguard, two lifeguards or a lifeguard with a layperson with no CPR training. Paired t-test and repeated analysis of variance were used to analyse CPR quality variables. RESULTS: Baseline CPR quality was adequate for most measures except compression depth and re-expansion. After water rescue, the single lifeguard trial showed no significant differences compared with baseline. CPR score and ventilation score of the single-lifeguard trial was higher than that of the lifeguard-bystander trial (p=0.027, p<0.001). Both the two-lifeguard trial (p=0.025), and lifeguard-bystander trial (p=0.010) had a lower percentage of breaths with correct ventilation volume and higher percentage of breaths with excessive ventilation volume (p=0.007, p=0.011, respectively) than the single-lifeguard trial. No-flow time of the lifeguard-bystander trial was longer than other trials (p<0.001). CONCLUSIONS: Although CPR given by the lifeguard was not optimal, fatigue generated by a water rescue has no impact on the quality of subsequent CPR performed by a trained lifeguard for 10 min. Untrained bystanders assisting in CPR in a drowning event is unlikely to be helpful.

Predictors of seasonal influenza vaccination behaviour among nurses and implications for interventions to increase vaccination uptake: A cross-sectional survey.

BACKGROUND: Vaccination has been proven the most effective method to prevent seasonal influenza. Nurses' vaccination can provide protection against influenza not only for themselves but also for patients they take care of. However, vaccination coverage of nurses is suboptimal worldwide, especially in China. The influencing factors need to be explored so as to develop specific, workable strategies to improve nurses' vaccination behaviour. OBJECTIVES: To explore predictors of their vaccination behaviour, identify the motivators and barriers of vaccination, and provide implications for future interventions. DESIGN: A cross-sectional convenience sampling questionnaire survey. SETTINGS: Nine hospitals including five tertiary hospitals, two secondary hospitals, and two primary hospitals in Shanghai, China. PARTICIPANTS: A total of 1000 nurses from the nine hospitals were invited to participate in this survey. Among them, 921 nurses responded and 895 returned valid questionnaires that were used in data analysis. METHODS: The Chinese version of the King's Nurses' Influenza Vaccination Questionnaire was used as the survey instrument and distributed to the participants during February-November 2012. Descriptive statistics, univariate analyses, and multivariate analyses were conducted to explore the predictors of nurses' vaccination behaviour. RESULTS: Overall, 8.8% of the respondents received seasonal influenza vaccination in the past influenza season (2011/2012 season). Nurses had averagely received 0.38 ±â€¯0.71 influenza vaccines during the past five influenza seasons (2007/2008 to 2011/2012 season). Predictors of nurses' vaccination status were clinical specialty, knowledge about influenza vaccination [1.331 (1.102, 1.608), p = 0.003], internal health locus of control [0.910 (0.845, 0.980), p = 0.013], chance health locus of control [1.075 (1.023, 1.130), p = 0.004]and powerful others health of locus control [1.166 (1.083, 1.255), p < 0.001]. Predictors of their vaccination times were hospital level, clinical specialty, and knowledge about influenza vaccination [1.458 (1.242, 1.711), p < 0.001]. Self-protection was the most common cited reason for getting vaccinated, and "no need" was cited as the most common refusal reason. CONCLUSIONS: This is the first well-designed study conducted in mainland China to explore nurses' vaccination behaviour against seasonal influenza. Vaccination coverage in this population was suboptimal. Mandatory vaccination policy should be implemented and attempts of multi-faceted interventions including specific education might also be needed.

A Survey of Snakebite Knowledge among Field Forces in China.

BACKGROUND: A snakebite is a neglected extrinsic injury associated with high morbidity and global mortality. Members of Chinese field forces are at high risk of snakebites, and their perception and knowledge of snakebites are unknown. The aim of this study is to assess perception and knowledge of snakebites in field forces in southeast China; Methods: A cross-sectional questionnaire-based survey was conducted in July 2016. A total of 216 field force members participated in this study; Results: A total of 10.3% had experienced snakebites and 86.4% rated their demands for knowledge about snakebite as "high". No significant correlation between the actual and perceived snakebite knowledge status was detected (κ = 0.0237, p = 0.3852). Ineffective and harmful traditional first-aid methods, such as the application of tourniquets, sucking the venom out of the wound, and making local incisions, were used by more than three quarters of the respondents. However, pressure immobilization bandages were applied by only 17.3% of members. The proportion of responses for each question was not significantly different among the respondents when considering separate demographic groups; Conclusions: Snakebite knowledge among Chinese field force members is inadequate and in some cases misleading, when focusing on manifestation, prevention, and first-aid. A pragmatic, intensive educational scheme should be undertaken in at-risk populations.

Use and implementation of standard operating procedures and checklists in prehospital emergency medicine: a literature review.

OBJECTIVES: This review aimed to analyze published literature to introduce the use and implementation of standard operating procedures (SOPs) and checklists in prehospital emergency medicine and their impact on guideline adherence and patient outcome. METHODS: An English literature search was carried out using the Cochrane Library, MEDLINE, EMBASE, Springer, Elsevier, and ProQuest databases. Original articles describing the use and implementation of SOPs or checklists in prehospital emergency medicine were included. Editorials, comments, letters, bulletins, news articles, conference abstracts, and notes were excluded from the analysis. Relevant information was extracted relating to application areas, development of SOPs/checklists, educational preparation and training regarding SOPs/checklists implementation, staff attitudes and the effects of SOPs/checklists use on guideline adherence and patient outcomes. RESULTS: The literature search found 2187 potentially relevant articles, which were narrowed down following an abstract review and a full text review. A final total of 13 studies were identified that described the use and implementation of SOPs (9 studies) and checklists (4 studies) in different areas of prehospital emergency medicine including prehospital management of patients with acute exacerbated chronic obstructive pulmonary disease and acute coronary syndrome, prehospital airway management, medical documentation, Emergency Medical Services triage, and transportation of patients. CONCLUSIONS: The use and implementation of SOPs and checklists in prehospital emergency medicine have shown some benefits of improving guidelines adherence and patient outcomes in airway management, patient records, identification and triage, and other prehospital interventions. More research in this area is necessary to optimize the future use and implementation of SOPs and checklists to improve emergency personnel performance and patient outcomes.

A Survey of Jellyfish Sting Knowledge among Naval Personnel in Northeast China.

BACKGROUND: Jellyfish envenomation is common along the coastal area, and can cause severe consequences. Naval personnel are among the high-risk population for this injury. The aim of this study was to assess knowledge regarding jellyfish envenomation among naval personnel in a navy unit in northeast China. METHODS: A predesigned questionnaire was distributed to 120 naval members in January 2015. The data of 108 respondents were included in the statistical analysis. RESULTS: We found that 38.0% of the respondents selected jellyfish sting as the common wound in their units, and 13.0% had experienced or observed this injury. In addition, 63.0% of the participants rated their own knowledge as "low" or "none". The average score they got was 5.77 ± 2.50, with only 16.7% getting a score above 60% of the full score. The correct rates of five questions were below 60%. No statistical differences existed in the knowledge score among different groups of respondents defined by socio-demographic variables. CONCLUSIONS: Jellyfish sting is common in this navy unit, but personnel got a low score on the knowledge assessment. They also lacked confidence in first aid. Medical education and training should be implemented to address this issue.