Direct versus indirect epiglottis elevation in cervical spine movement during videolaryngoscopic intubation under manual in-line stabilization: a randomized controlled trial.

BACKGROUND: During videolaryngoscopic intubation, direct epiglottis elevation provides a higher percentage of glottic opening score than indirect epiglottis elevation. In this randomized controlled trial, we compared cervical spine movement during videolaryngoscopic intubation under manual in-line stabilization between the two glottis exposure methods. METHODS: Videolaryngoscopic intubation under manual in-line stabilization was performed using C-MAC® D-blade: direct (n = 51) and indirect (n = 51) epiglottis elevation groups. The percentage of glottic opening score was set equally at 50% during videolaryngoscopic intubation in both groups. The primary outcome measure was cervical spine movement during videolaryngoscopic intubation at the occiput-C1, C1-C2, and C2-C5. The secondary outcome measures included intubation performance (intubation success rate and intubation time). RESULTS: Cervical spine movement during videolaryngoscopic intubation was significantly smaller at the occiput-C1 in the direct epiglottis elevation group than in the indirect epiglottis elevation group (mean [standard deviation] 3.9 [4.0] vs. 5.8 [3.4] °, P = 0.011), whereas it was not significantly different at the C1-C2 and C2-C5 between the two groups. All intubations were successful on the first attempt, achieving a percentage of glottic opening score of 50% in both groups. Intubation time was longer in the direct epiglottis elevation group (median [interquartile range] 29.0 [24.0-35.0] vs. 22.0 [18.0-27.0] s, P < 0.001). CONCLUSIONS: When performing videolaryngoscopic intubation under manual in-line stabilization, direct epiglottis elevation can be more beneficial than indirect epiglottis elevation in reducing cervical spine movement during videolaryngoscopic intubation at the occiput-C1. TRIAL REGISTRATION: Clinical Research Information Service (number: KCT0006239, date: 10/06/2021).

Effect of Electrolyte Chemistry and Sulfur Content in Li||Sulfurized Polyacrylonitrile (SPAN) Batteries.

Sulfurized polyacrylonitrile (SPAN) is considered as a high-value cathode material, which leverages the high energy of S redox while mitigating the negative externalities that limit elemental S cycling. As such, the sulfur content in Li-SPAN batteries plays a critical role. In this work, we demonstrate that high-S loading SPAN cathodes, where the PAN backbone approaches the saturation point without signs of elemental S, are highly dependent on the electrolyte chemistry for long-term reversibility. Specifically, we find that a localized-high-concentration electrolyte (LHCE) further enhances the reversible capacity and cycling stability of SPAN cathode with optimized S content relative to a carbonate control, largely due to the formation of a compatible interphase. With this LHCE as the electrolyte and 43% sulfur ratio of SPAN as the cathode, a full cell applying N/P ratio = 1.82, a cathode loading of 6 mAh cm-2 (9.2 mg cm-2), and an electrolyte loading of 7 µL mg-1 SPAN can be cycled for 100 cycles with 433 mAh g-1 retained capacity and retains much of this reversibility even at 60 °C. This work reveals the molecular origin of optimized sulfur ratio in SPAN cathodes while providing guidance in electrolyte design for Li||SPAN cells with high capacity and cyclability.

Unravelling Ultrafast Li Ion Transport in Functionalized Metal-Organic Framework-Based Battery Electrolytes.

Nonaqueous fluidic transport and ion solvation properties under nanoscale confinement are poorly understood, especially in ion conduction for energy storage and conversion systems. Herein, metal-organic frameworks (MOFs) and aprotic electrolytes are studied as a robust platform for molecular-level insights into electrolyte behaviors in confined spaces. By employing computer simulations, along with spectroscopic and electrochemical measurements, we demonstrate several phenomena that deviate from the bulk, including modulated solvent molecular configurations, aggregated solvation structures, and tunable transport mechanisms from quasi-solid to quasi-liquid in functionalized MOFs. Technologically, taking advantage of confinement effects may prove useful for addressing stability concerns associated with volatile organic electrolytes while simultaneously endowing ultrafast transport of solvates, resulting in improved battery performance, even at extreme temperatures. The molecular-level insights presented here further our understanding of structure-property relationships of complex fluids at the nanoscale, information that can be exploited for the predictive design of more efficient electrochemical systems.

High-Performance Electrochromic Devices Based on Size-Controlled 2D WO3 Nanosheets Prepared Using the Intercalation Method.

It is difficult to obtain ultrathin two-dimensional (2D) tungsten trioxide (WO3) nanosheets through direct exfoliation from bulk WO3 in solution due to the strong bonding between interlayers. Herein, WO3 nanosheets with controllable sizes were synthesized via K+ intercalation and the exfoliation of WO3 powder using sonication and temperature. Because of the intercalation and expansion in the interlayer distance, the intercalated WO3 could be successfully exfoliated to produce a large quantity of individual 2D WO3 nanosheets in N-methyl-2-pyrrolidone under sonication. The exfoliated ultrathin WO3 nanosheets exhibited better electrochromic performance in an electrochromic device than WO3 powder and exfoliated WO3 without intercalation. In particular, the prepared small WO3 nanosheets exhibited excellent electrochromic properties with a large optical modulation of 41.78% at 700 nm and fast switching behavior times of 9.2 s for bleaching and 10.5 s for coloring. Furthermore, after 1000 cycles, the small WO3 nanosheets still maintained 86% of their initial performance.

Holistic Design Consideration of Metal-Organic Framework-Based Composite Membranes for Lithium-Sulfur Batteries.

Metal-organic framework (MOF)-based membranes have received significant attention as separators for lithium-sulfur (Li-S) batteries because of their high porosities, well-defined and tailored structures, and other tunable features that are desirable for preventing the "shuttle effect" of soluble polysulfides. Because of the insulating nature of most MOFs, composite membranes are generally constructed by a combination of MOFs and electron-conductive materials. In this work, we examine the property-performance relation between MOF-based separators and Li-S batteries by systematically adjusting the electrical conductivity, thickness, and mass loading of the MOF-based composite. Beyond the commonly referenced trapping or blocking ability of MOFs toward polysulfides, we find that by fixing the thickness of the MOF-based composite coating layer (∼40 µm) on a Celgard membrane, the electrical conductivity of the MOF composite layer is of paramount importance compared with the physical/chemical trapping ability of polysulfides. However, the trapping ability of MOFs becomes indispensable when the thickness of the composite layer is small (e.g., ∼20 µm), indicating the synergetic effects of the adsorption and conversion capabilities of the thin composite layer. This work suggests the importance of a holistic design consideration for a MOF-based membrane for long-life and high-energy-density Li-S batteries.

Dissipation characteristics of spirotetramat and its metabolites in two phenotypically different Korean vegetables under greenhouse conditions.

This study involved analysis and method validation of spirotetramat applied to two phenotypically different Korean vegetables (e.g. Korean cabbage and shallots) to determine the safe pre-harvest residue limit (PHRL) and comparative dissipation patterns. Two steps of the investigation involved greenhouse monitoring during crop cultivation followed by LC-MS/MS analysis. Commercial spirotetramat was sprayed twice with seven-day intervals according to the spray schedule (0, 3, 7, 10, 14, and 21 days before harvest) at the dose recommended by the Ministry of Food and Drug Safety (MFDS), Korea. During the validation of the analytical method, good linearity, specificity, and acceptable recoveries (82%-114% for Korean cabbage and 82%-111% for shallot) were established for spirotetramat and its four metabolites. The calculated biological half-life derived from the first-order reaction (t1/2) of spirotetramat was 4.8 days for Korean cabbage and 4.0 days for shallot, respectively. The safe PHRL for Korean cabbage was suggested at 7 days, due to permissible spirotetramat concentration in terms of an acceptable MRL. The findings of the study will be used as the analytical reference point for developing spirotetramat safety guidelines for use in the vegetables investigated.

Biodegradable Metallic Glass for Stretchable Transient Electronics.

Biodegradable electronics are disposable green devices whose constituents decompose into harmless byproducts, leaving no residual waste and minimally invasive medical implants requiring no removal surgery. Stretchable and flexible form factors are essential in biointegrated electronic applications for conformal integration with soft and expandable skins, tissues, and organs. Here a fully biodegradable MgZnCa metallic glass (MG) film is proposed for intrinsically stretchable electrodes with a high yield limit exploiting the advantages of amorphous phases with no crystalline defects. The irregular dissolution behavior of this amorphous alloy regarding electrical conductivity and morphology is investigated in aqueous solutions with different ion species. The MgZnCa MG nanofilm shows high elastic strain (≈2.6% in the nano-tensile test) and offers enhanced stretchability (≈115% when combined with serpentine geometry). The fatigue resistance in repeatable stretching also improves owing to the wide range of the elastic strain limit. Electronic components including the capacitor, inductor, diode, and transistor using the MgZnCa MG electrode support its integrability to transient electronic devices. The biodegradable triboelectric nanogenerator of MgZnCa MG operates stably over 50 000 cycles and its fatigue resistant applications in mechanical energy harvesting are verified. In vitro cell toxicity and in vivo inflammation tests demonstrate the biocompatibility in biointegrated use.

Onsite/on-field analysis of pesticide and veterinary drug residues by a state-of-art technology: A review.

Pesticides and veterinary drugs are generally employed to control pests and insects in crop and livestock farming. However, remaining residues are considered potentially hazardous to human health and the environment. Therefore, regular monitoring is required for assessing and legislation of pesticides and veterinary drugs. Various approaches to determining residues in various agricultural and animal food products have been reported. Most analytical methods involve sample extraction, purification (cleanup), and detection. Traditional sample preparation is time-consuming labor-intensive, expensive, and requires a large amount of toxic organic solvent, along with high probability for the decomposition of a compound before the analysis. Thus, modern sample preparation techniques, such as the quick, easy, cheap, effective, rugged, and safe method, have been widely accepted in the scientific community for its versatile application; however, it still requires a laboratory setup for the extraction and purification processes, which also involves the utilization of a toxic solvent. Therefore, it is crucial to elucidate recent technologies that are simple, portable, green, quick, and cost-effective for onsite and infield residue detections. Several technologies, such as surface-enhanced Raman spectroscopy, quantum dots, biosensing, and miniaturized gas chromatography, are now available. Further, several onsite techniques, such as ion mobility-mass spectrometry, are now being upgraded; some of them, although unable to analyze field sample directly, can analyze a large number of compounds within very short time (such as time-of-flight and Orbitrap mass spectrometry). Thus, to stay updated with scientific advances and analyze organic contaminants effectively and safely, it is necessary to study all of the state-of-art technology.

Smartphone / smartwatch-based cuffless blood pressure measurement : a position paper from the Korean Society of Hypertension.

Smartphone technology has spread rapidly around the globe. According to a report released by the Korea Information Society Development Institute, about 95% of Koreans aged more than 30 years old owned smartphones. Recently, blood pressure (BP) measurement using a photoplethysmography-based smartphone algorithm paired with the smartwatch is continuously evolving. In this document, the Korean Society of Hypertension intends to remark the current results of smartphone / smartwatch-based BP measurement and recommend optimal BP measurement methods using a smartphone device. We aim to increase the likelihood of success in implementing these new technologies into improved hypertension awareness, diagnosis, and control.

Highly luminescent polyethylene glycol-passivated graphene quantum dots for light emitting diodes.

The emergence of fluorescent graphene quantum dots (GQDs) is expected to enhance the usefulness of quantum dots (QDs), in terms of their unique luminescence, photostability, low toxicity, chemical resistance, and electron transport properties. Here we prepared blue-photoluminescent polyethylene glycol GQDs (PEG-GQDs) through PEG surface passivation. The photoluminescence (PL) quantum yield (QY) of PEG-GQDs with 320 nm excitation was about 4.9%, which was higher than that of pure GQDs. The as-fabricated PEG-GQDs with high QY were then used as light-emitting diode (PGQD-LED) emitters, in which the GQDs were incorporated into polymeric host layers in a multilayer electroluminescent device; blue emission with a luminance exceeding 800 cd m-2 was achieved, thus demonstrating the potential of PEG-GQDs as emitters in electroluminescence applications. Furthermore, the fluorescence mechanism of PEG-GQDs was investigated and proved that the origin of strong fluorescence of PEG-GQDs is associated with the luminescence from intrinsic states. The highly fluorescent PEG-GQDs will allow new devices, such as multicolor LEDs, to be developed with extraordinary properties, by tailoring the intrinsic and extrinsic states.

Versatile and Tunable Electrical Properties of Doped Nonoxidized Graphene Using Alkali Metal Chlorides.

With the rapid development of wearable and flexible electronics, graphene has been intensively studied for the transparent, hole transport electrode layer (HTL) of field-effect transistors, light-emitting diodes, and organic photovoltaic (OPV) cells. To modulate the sheet resistance and the work function of graphene as a HTL, the surface doping is versatile while retaining high transparency. In this work, we used a chemical doping method to control the charge carrier density, band gap, and work function of graphene with minimizing the damage of the carbon network, for which metal chlorides (NaCl, KCl, and AuCl3) were used as chemical dopants. The high-quality graphene flakes were synthesized with large lateral sizes of more than 5 µm using ternary graphite intercalation compounds. Interestingly, the AuCl3-doped graphene flake film with a film thickness of about 20 nm showed the lowest reported sheet resistance of ∼249 Ω/sq with ∼75% transmittance. Furthermore, it could control the work function from 4.32 to 5.1 eV. The interfacial dipole complexes of metal cations with a low work function and the reactive radicals such as -OH were discussed to explain this result. For the practical application, an OPV device using the AuCl3-doped graphene flake film as the HTL was fabricated and it demonstrated enhanced power conversion efficiency while maintaining high optical transparency in visible light.

Improvement of the Electrical Properties of a Cu(In,Ga)Se2 Solar Cell Based on a ZnS Buffer Layer from Radio Frequency Magnetron Sputtering.

We fabricated zinc sulfide (ZnS) buffer layers with a great band gap and small light loss at a short wavelength, and then applied them to copper indium gallium sulphur-selenide (CIGS) thin film solar cells. A CIGS evaporation system was used for fabrication of the CIGS thin films, and a thickness monitor was used to check the evaporation rate at each source. The evaporation rate and deposition time were adjusted to change the composition ratio of the thin films. Also, CIGS thin films were deposited by changing the temperature of the substrates from room temperature (RT) to 150 °C, 250 °C, and 350 °C during ZnS deposition, and among them, the optimal substrate temperature was selected to measure the light conversion efficiency of ZnS-deposited CIGS thin film solar cells. The grown ZnS thin films were analyzed for crystallinity and composition by using X-ray diffraction, and by using a scanning electron microscope, the cross section and surface shape of the thin films were examined. When we applied the ZnS thin film that was fabricated at a temperature of 150 °C with a thickness of 50 nm as a buffer layer for the CIGS solar cells, we obtained a light conversion efficiency of 14.48% without an antireflection layer.

High-Efficiency Cu(In,Ga)Se2 Thin Film Solar Cells Using ZnS and CdS Buffer Layers.

Most of the existing copper indium gallium diselenide (CIGS) thin film solar cells are based on a cadmium sulfide (CdS) buffer layer fabricated using a chemical bath deposition (CBD) process. However, due to environmental pollution caused by material toxicity and the unique wet process's incompatibility with the vacuum process, many studies are now being actively carried out on nontoxic buffer layers. In this study, to replace CdS buffer layers, zinc sulfide (ZnS) buffer layers with a big band gap and a low optical loss at a short wavelength were fabricated using a magnetron sputtering system. For comparative analysis, this study also fabricated CdS buffer layers using the CBD process. Then, the conversion efficiency of CIGS thin film solar cells deposited with ZnS and CdS thin film as buffer layers was measured. The light conversion efficiency of ZnS buffer layer-based CIGS was measured at 14.44%, while that of the CdS buffer layer-based CIGS was measured at 15.71%. Given that both are higher than the minimum conversion efficiency required for commercialization (10%), ZnS buffer layer-based solar cells could have a competitive edge over the existing CdS buffer layer-based solar cells.

Identification of a Bromodomain-containing Protein 2 (BRD2) Gene Polymorphic Variant and Its Effects on Pork Quality Traits in Berkshire Pigs.

Bromodomain-containing protein 2 (BRD2) is a nuclear serine/threonine kinase involved in transcriptional regulation. We investigated the expression and association of the BRD2 gene as a candidate gene for meat quality traits in Berkshire pigs. BRD2 mRNA was expressed at relatively high levels in muscle tissue. Statistical analysis revealed that the c.1709G>C polymorphism of the BRD2 gene was significantly associated with carcass weight, meat color (a*, redness), protein content, cooking loss, water-holding capacity, carcass temperatures 4, 12 and 24 h postmortem, and the 24 h postmortem pH in 384 Berkshire pigs. Therefore, this polymorphism in the porcine BRD2 gene may be used as a candidate genetic marker to improve meat quality traits in pigs.

Analysis of two quorum sensing-deficient isolates of Pseudomonas aeruginosa.

Three strains of Pseudomonas aeruginosa were isolated: wild-type (WT, NO4) showed normal quorum sensing (QS), whereas QSD3 and QSD7 were QS-deficient (QSD) containing limited N-butyryl homoserine lactone (C4-HSL). The autoinducer activity produced by NO4 was found to be at least 50-fold higher than those by the QSD3 and the QSD7 strains. The QSDs produced lower levels of phenazine compounds (pyocyanin), siderophores (pyoverdine) and biosurfactants (rhamnolipids) than NO4. Therefore, the swarming motility and the swimming motility of the QSD3 and the QSD7 strains also decreased. Treatment with exogenous C4-HSL completely restored rhamnolipid production in both QSDs, suggesting that the biosynthesis of C4-HSL is defective. However, the biofilm production of the QSDs reached much higher levels than those of wild-types (NO4 and P. aeruginosa PAO1). And both QSD strains were more resistant than wild-type cell (NO4) against kanamycin and tobramycin. The RpoS gene, which function is related with QS, is point-nonsense mutated in QSD3 strain. But eleven QS-related genes in QSD3 were not mutated, compared to those of PAO1, which carries intact QS genes and is used as a positive control. This study is helpful in the development of novel approaches in the treatment of P. aeruginosa infections.

Superoxide serves as a putative signal molecule for plant cell division: overexpression of CaRLK1 promotes the plant cell cycle via accumulation of O2- and decrease in H2 O2.

Reactive oxygen species (ROS) exert both positive and negative effects on plant growth and development and therefore receive a great deal of attention in current research. A hot pepper, Capsicum annuum receptor-like kinase 1 (CaRLK1) was ectopically expressed in Nicotiana tabacum BY-2 cell and Nicotiana benthamiana plants. This ectopic expression of CaRLK1 enhanced cell division and proliferation in both heterologous systems. Apparently, CaRLK1 is involved in controlling the cell cycle, possibly by inducing expressions of cyclin B1, cyclin D3, cyclin-dependent protein kinase 3, condensin complex subunit 2 and anaphase-promoting complex subunit 11 genes. CaRLK1 overexpression also increased transcript accumulation of NADPH oxidase genes, generation of O2- and catalase (CAT) activity/protein levels. In parallel, it decreased cellular H2 O2 levels and cell size. Treatment with Tiron or diphenyleneiodonium (DPI) both decreased the cell division rate and O2- concentrations, but increased cellular H2 O2 levels. Tobacco BY-2 cells overexpressing CaRLK1 were more sensitive to amino-1,2,4-triazole (3-AT), a CAT inhibitor, than control cells, suggesting that the increased H2 O2 levels may not function as a signal for cell division and proliferation. Overexpression of CaRLK1 stimulated progression of the cell cycle from G0 /G1 phase into the S phase. It is concluded that the CaRLK1 protein plays a pivotal role in controlling the level of O2- as signaling molecule which promotes cell division, concomitant with a reduction in H2 O2 by the induction of CAT activity/protein.

Bandgap Widening of Phase Quilted, 2D MoS2 by Oxidative Intercalation.

Controllable bandgap widening from 1.8 to 2.6 eV is reported from oxidized MoS2 sheets that are composed of quilted phases of various MoSxOy flakes. The exfoliated flakes have large size (≥100 µm × 100 µm) sheets with average thickness of 1.7 nm. Remarkably, fine reversible tuning of the bandgap is achieved by postprocessing sulfurization of the MoSxOy sheets.

Ectopic expression of CaRLK1 enhances hypoxia tolerance with increasing alanine production in Nicotiana spp.

In a previous report, the pepper receptor-like kinase 1 (CaRLK1) gene was shown to be responsible for negatively regulating plant cell death caused by pathogens via accumulation of superoxide anions. Here, we examined whether this gene also plays a role in regulating cell death under abiotic stress. The total concentrations of free amino acids in CaRLK1-overexpressed cells (RLKox) increased by twofold compared with those of the wild-type Nicotiana tabacum BY-2 cells. Additionally, alanine and pyruvate concentrations increased by approximately threefold. These accumulations were associated with both the expression levels of the isocitrate lyase (ICL) and malate synthase genes and their specific activities, which were preferentially up-regulated in the RLKox cells. The expression levels of ethylene biosynthetic genes (ACC synthase and ACC oxidase) were suppressed, but those of both the metallothionein and lesion simulating disease 1 genes increased in the RLKox cells during submergence-induced hypoxia. The specific activity of catalase, which is involved in protecting ICL from reactive oxygen species, was also induced threefold in the RLKox cells. The primary roots of the transgenic plants that were exposed to hypoxic conditions grew at similar rates to those in normal conditions. We propose that CaRLK1 maintains a persistent hypoxia-resistant phenotype.

Cobalt-free nickel rich layered oxide cathodes for lithium-ion batteries.

We propose a feasibility of Co-free Ni-rich Li(Ni(1-x)Mn(x))O2 layer compound. Li(Ni(1-x)Mn(x))O2 (0.1 ≤ x ≤ 0.5) have been synthesized by a coprecipitation method. Rietveld refinement of X-ray diffraction and microscopic studies reveal dense and spherical secondary particles of highly crystalline phase with low cation mixing over the whole compositions, implying successful optimization of synthetic conditions. Electrochemical test results indicated that the Co-free materials delivered high capacity with excellent capacity retention and reasonable rate capability. In particular, Li(Ni0.9Mn0.1)O2, which possesses the lowest cation mixing in the Li layers among samples, exhibited exceptionally high rate capacity (approximately 149 mAh g(-1) at 10 C rate) at 25 °C and high discharge capacity upon cycling under a severe condition, in the voltage range of 2.7-4.5 V at 55 °C. The cation mixing in Li(Ni0.9Mn0.1)O2 increased slightly even after the extensive cycling at the elevated temperature, which is ascribed to the structural integrity induced from the optimized synthetic condition using the coprecipitation.

Progress in lithium-sulfur batteries: the effective role of a polysulfide-added electrolyte as buffer to prevent cathode dissolution.

Paving the road for sulfur: A unique electrolyte composition designed for the development of stable lithium-sulfur batteries with high energy. A battery with a high and stable capacity is prepared by using an electrolyte containing a dissolved catholyte-type compound, that is, Li2 S8 polysulfide. The cell is characterized by a capacity approaching the theoretical value at a working voltage of 2.1 V, which is remarkable compared to conventional lithium ion batteries.