Dose pre-hospital laryngeal mask airway use has a survival benefit in non-shockable cardiac arrest?

Background. Whether pre-hospital laryngeal mask airway (LMA) use poses a survival benefit and should be approved as routine airway management in non-shockable cardiac arrest is of major concern. The present study examined the effectiveness of LMA, in comparison to other pre-hospital airway management on individuals who have experienced non-shockable cardiac arrest. Methods. Adult patients who experienced non-shockable cardiac arrest with activation of the emergency medical service (EMS) made up our study cohort in Taoyuan, Taiwan. The data were abstracted from EMS records and cardiac arrest registration protocols. Results. Among the 1912 enrolled patients, most received LMA insertion (72.4%), 108 (5.6%) bag-valve-mask (BVM) ventilation, 376 (19.7%) high-flow oxygen non-rebreather facemask, and only 44 (2.3%) received endotracheal tube intubation (ETI). With regard to survival to discharge, no significant differences in prevalence were evident among the groups: 2.8% of oxygen facial mask, 1.1% of BVM, 2.1% of LMA, and 4.5% of the ETI group survived to discharge (p = 0.314). In comparison to oxygen facial mask use, different types of airway management remained unassociated with survival to discharge after adjusting for variables by logistic regression analysis (BVM: 95% confidence interval [CI], 0.079 – 1.639 [p = 0.186]; LMA: 95% CI, 0.220–2.487 [p = 0.627]; ETI: 95% CI, 0.325–17.820 [p = 0.390]). The results of Hosmer-Lemeshow goodness-of-fit test of logistic regression model revealed good calibration. Conclusions. Pre-hospital LMA use was not associated with additional survival to discharge compared with facial oxygen mask, BVM, or ETI following non-shockable cardiac arrest

Autophagy regulation in heme-induced neutrophil activation is associated with microRNA expression on transfusion-related acute lung injury

AbstractTransfusion-related acute lung injury (TRALI) is the leading cause of death after transfusion therapy. The pathogenesis of TRALI is associated with neutrophil activation in the lungs, causing endothelial damage and capillary leakage, and thus neutrophil extravasation. Heme-related molecules derived from the hemolysis of red blood cell components have been recognized as a stimulator, inducing neutrophil activation at TRALI. To investigate post-transcriptional changes of the neutrophil at TRALI, we performed heme-related molecules induced reactive oxygen species production in the neutrophil as a model. Neutrophils were isolated from heparinized peripheral blood and stimulated with heme-related molecules. After stimulation, reactive oxygen species production, degranulation, phagocytosis activity, and miRNA expression profile of neutrophil were analyzed by luminol assay, flow cytometry, and real-time polymerase chain reaction. The expression of miRNA targeting NADPH oxidase and autophagy in the neutrophil activation of TRALI was explored. The expression profile of miRNAs will be a useful predictor of disease severity and for the grading of patients for transfusion

Rate adaptation for 802.11 multiuser mimo networks

In multiuser MIMO (MU-MIMO) networks, the optimal bit rate of a user is highly dynamic and changes from one packet to the next. This breaks traditional bit rate adaptation algorithms, which rely on recent history to predict the best bit rate for the next packet. To address this problem, we introduce TurboRate, a rate adaptation scheme for MU-MIMO LANs. TurboRate shows that clients in a MU-MIMO LAN can adapt their bit rate on a per-packet basis if each client learns two variables: its SNR when it transmits alone to the access point, and the direction along which its signal is received at the AP. TurboRate also shows that each client can compute these two variables passively without exchanging control frames with the access point. A TurboRate client then annotates its packets with these variables to enable other clients to pick the optimal bit rate and transmit concurrently to the AP. A prototype implementation in USRP-N200 shows that traditional rate adaptation does not deliver the gains of MU-MIMO WLANs, and can interact negatively with MU-MIMO, leading to low throughput. In contrast, enabling MU-MIMO with TurboRate provides a mean throughput gain of 1.7x and 2.3x, for 2-antenna and 3-antenna APs respectively.National Science Council (China) (contract No. NSC 100-2221-E-001-005-MY2)National Science Foundation (U.S.) (NSF Grant CNS-1117194

Pulsed laser deposition of hexagonal GaN-on-Si(100) template for MOCVD applications

Growth of hexagonal GaN on Si(100) templates via pulsed laser deposition (PLD) was investigated for the further development of GaN-on-Si technology. The evolution of the GaN growth mechanism at various growth times was monitored by SEM and TEM, which indicated that the GaN growth mode changes gradually from island growth to layer growth as the growth time increases up to 2 hours. Moreover, the high-temperature operation (1000°C) of the PLD meant no significant GaN meltback occurred on the GaN template surface. The completed GaN templates were subjected to MOCVD treatment to regrow a GaN layer. The results of X-ray diffraction analysis and photoluminescence measurements show not only the reliability of the GaN template, but also the promise of the PLD technique for the development of GaN-on-Si technology

Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in Ax_{x}Fe2−y_{2-y}Se2_2 (A=K, Rb) Superconductors

In this work, we study the A$_{x}$Fe$_{2-y}$Se$_2$ (A=K, Rb) superconductors using angle-resolved photoemission spectroscopy. In the low temperature state, we observe an orbital-dependent renormalization for the bands near the Fermi level in which the dxy bands are heavily renormliazed compared to the dxz/dyz bands. Upon increasing temperature to above 150K, the system evolves into a state in which the dxy bands have diminished spectral weight while the dxz/dyz bands remain metallic. Combined with theoretical calculations, our observations can be consistently understood as a temperature induced crossover from a metallic state at low temperature to an orbital-selective Mott phase (OSMP) at high temperatures. Furthermore, the fact that the superconducting state of A$_{x}$Fe$_{2-y}$Se$_2$ is near the boundary of such an OSMP constraints the system to have sufficiently strong on-site Coulomb interactions and Hund's coupling, and hence highlight the non-trivial role of electron correlation in this family of iron superconductors

Community-onset bacteremia in kidney transplant recipients: The recipients fare well in terms of mortality and kidney injury

BackgroundBloodstream infection is not uncommon in kidney transplant recipients (KTRs) and is associated with mortality, graft loss, and increased medical expenses. Whether these septic patients are more vulnerable to serious complications, resistant strains, or worse clinical outcomes than other patient groups in the community-onset settings remains undetermined.MethodsA retrospective study was conducted at a medical center in southern Taiwan. Community-onset bacteremia in the KTRs and a control population at the emergency department were identified. Demographic data, clinical characteristics, bacteremic pathogens, antimicrobial resistance, and clinical outcomes were recorded.ResultsForty-one bacteremic episodes in the KTRs and 82 episodes in control patients were studied. The KTR group had younger age, fewer malignancies, more urosepsis (61% vs. 22%, p = 0.004), and fewer biliary tract infections (0% vs. 13.4%, p = 0.018). Escherichia coli was the most commonly isolated pathogen in both the groups (51.2% and 41.5%, respectively). No Klebsiella pneumoniae bacteremia was noted in the KTRs, compared with 14 (17.1%) episodes in the control group (p = 0.010). Antimicrobial resistance profiles of bacteremic pathogens were similar (all p > 0.6). The KTRs with community-onset bacteremia did not have a worse outcome (in-hospital mortality rate: 2.4% vs. 10%, p = 0.172) nor more incomplete resolution of kidney injury after acute kidney injury events (21.1% vs. 25%, p > 0.99) than the control group.ConclusionKTRs with community-onset bacteremia did not fare worse in terms of clinical outcome and kidney injury

Service Quality of Online Shopping Platforms: A Case-Based Empirical and Analytical Study

Customer service is crucially important for online shopping platforms (OSPs) such as eBay and Taobao. Based on the well-established service quality instruments and the scenario of the specific case on Taobao, this paper focuses on exploring the service quality of an OSP with an aim of revealing customer perceptions of the service quality associated with the provided functions and investigating their impacts on customer loyalty. By an empirical study, this paper finds that the “fulfillment and responsiveness” function is significantly related to the customer loyalty. Further analytical study is conducted to reveal that the optimal service level on the “fulfillment and responsiveness” function for the risk averse OSP uniquely exists. Moreover, the analytical results prove that (i) if the customer loyalty is more positively correlated to the service level, it will lead to a larger optimal service level, and (ii) the optimal service level is independent of the profit target, the source of uncertainty, and the risk preference of the OSP