Electrochemical Analysis of Ion Effects on Electrolyte-Gated Synaptic Transistor Characteristics.

Electrolyte-gated transistors (EGTs) are promising candidates as artificial synapses owing to their precise conductance controllability, quick response times, and especially their low operating voltages resulting from ion-assisted signal transmission. However, it is still vague how ion-related physiochemical elements and working mechanisms impact synaptic performance. Here, to address the unclear correlations, we suggest a methodical approach based on electrochemical analysis using poly(ethylene oxide) EGTs with three alkali ions: Li+, Na+, and K+. Cyclic voltammetry is employed to identify the kind of electrochemical reactions taking place at the channel/electrolyte interface, which determines the nonvolatile memory functionality of the EGTs. Additionally, using electrochemical impedance spectroscopy and qualitative analysis of electrolytes, we confirm that the intrinsic properties of electrolytes (such as crystallinity, solubility, and ion conductivity) and ion dynamics ultimately define the linearity/symmetricity of conductance modulation. Through simple but systematic electrochemical analysis, these results offer useful insights for the selection of components for high-performing artificial synapses.

Oxide Semiconductor Heterojunction Transistor with Negative Differential Transconductance for Multivalued Logic Circuits.

Multivalued logic (MVL) technology is a promising solution for improving data density and reducing power consumption in comparison to complementary metal-oxide-semiconductor (CMOS) technology. Currently, heterojunction transistors (TRs) with negative differential transconductance (NDT) characteristics, which play an important role in the function of MVL circuits, adopt organic or 2D semiconductors as active layers, but it is still difficult to apply conventional CMOS processes. Herein, we demonstrate an oxide semiconductor (OS) heterojunction TR with NDT characteristics composed of p-type copper(I) oxide (Cu2O) and n-type indium gallium zinc oxide (IGZO) using the conventional CMOS manufacturing processes. The electrical characteristics of the fabricated device exhibit a high Ion/Ioff ratio (∼3 × 103), wide NDT ranges (∼29 V), and high peak-to-valley current ratios (PVCR ≈ 25). The electrical properties of 15 devices were measured, confirming uniform performance in the PVCR, NDT range, and Ion/Ioff ratio. We analyze the device operation by varying the source/drain (S/D) position and changing the device geometry and the thickness of the Cu2O layer. Additionally, we demonstrate heterojunction ambipolar TR to elucidate the transport mechanism of NDT devices at a high gate voltage (VGS). To confirm the feasibility of the MVL circuit, we present a ternary inverter with three clearly expressed logic states that have a long intermediate state and greater margin of error induced by wide NDT regions and high PVCR.

Differences in Oxygen-Induced Retinopathy Susceptibility Between Two Sprague Dawley Rat Vendors: A Comparison of Retinal Transcriptomes.

PURPOSE: To determine the retinal transcriptomic differences underlying the oxygen-induced retinopathy phenotypes between Sprague Dawley rat pups from two commonly used commercial vendors. This will allow us to discover genes and pathways that may be related to differences in disease severity in similarly aged premature babies and suggest possible new treatment approaches. METHODS: We analyzed retinal vascular morphometry and transcriptomes from Sprague Dawley rat pups from Charles River Laboratories and Envigo (previously Harlan). Room air control and oxygen-induced retinopathy groups were compared. Oxygen-induced retinopathy was induced with the rat 50/10 model. RESULTS: Pups from Charles River Laboratories developed a more severe oxygen-induced retinopathy phenotype, with 3.6-fold larger percent avascular area at P15 and twofold larger % neovascular area at P20 than pups from Envigo. Changes in retinal transcriptomes of rat pups from both vendors were substantial at baseline and in response to oxygen-induced retinopathy. Baseline differences centered on activated pathways of neuronal development in Charles River Laboratories pups. In response to oxygen-induced retinopathy, during the neovascular phase, retinas from Charles River Laboratories pups exhibited activation of pathways regulating necrosis, neuroinflammation, and interferon signaling, supporting the observed increase of neovascularization. Conversely, retinas from Envigo pups showed decreased necrosis and increased focal adhesion kinase signaling, supporting more normal vascular development. Comparing oxygen-induced retinopathy transcriptomes at P15 to those at P20, canonical pathways such as phosphate and tensin homolog, interferon, and coordinated lysosomal expression and regulation element signaling were identified, highlighting potential novel mechanistic targets for future research. CONCLUSION: Transcriptomic profiles differ substantially between rat pup retinas from Charles River Laboratories and Envigo at baseline and in response to oxygen-induced retinopathy, providing insight into vascular morphologic differences. Comparing transcriptomes identified new pathways for further research in oxygen-induced retinopathy pathogenesis and increased scientific rigor of this model.

Dual Function of N-Iodosuccinimide for C(sp3)-B Bond Activation.

A practical method for C(sp3)-B bond activation was developed. Using a combination of alkyl trifluoroborates and N-iodosuccinimide (NIS), various C(sp3)-heteroatom bonds were readily generated in an efficient manner. Mechanistic studies revealed the bifunctional ability of NIS: mediating the formation of reactive halogenated intermediates and activating them via halogen bonding. This electrophilic activation of the reaction center enables the utilization of general heteroatom nucleophiles, which are used in a limited capacity in traditional 1,2-metalate rearrangements.

Machine Learning Driven Channel Thickness Optimization in Dual-Layer Oxide Thin-Film Transistors for Advanced Electrical Performance.

Machine learning (ML) provides temporal advantage and performance improvement in practical electronic device design by adaptive learning. Herein, Bayesian optimization (BO) is successfully applied to the design of optimal dual-layer oxide semiconductor thin film transistors (OS TFTs). This approach effectively manages the complex correlation and interdependency between two oxide semiconductor layers, resulting in the efficient design of experiment (DoE) and reducing the trial-and-error. Considering field effect mobility (𝜇) and threshold voltage (Vth ) simultaneously, the dual-layer structure designed by the BO model allows to produce OS TFTs with remarkable electrical performance while significantly saving an amount of experimental trial (only 15 data sets are required). The optimized dual-layer OS TFTs achieve the enhanced field effect mobility of 36.1 cm2  V-1  s-1 and show good stability under bias stress with negligible difference in its threshold voltage compared to conventional IGZO TFTs. Moreover, the BO algorithm is successfully customized to the individual preferences by applying the weight factors assigned to both field effect mobility (𝜇) and threshold voltage (Vth ).

Solvent-assisted sulfur vacancy engineering method in MoS2 for a neuromorphic synaptic memristor.

Recently, two-dimensional transition metal dichalcogenides (TMDs) such as molybdenum disulfide (MoS2) have attracted great attention due to their unique properties. To modulate the electronic properties and structure of TMDs, it is crucial to precisely control chalcogenide vacancies and several methods have already been suggested. However, they have several limitations such as plasma damage by ion bombardment. Herein, we introduced a novel solvent-assisted vacancy engineering (SAVE) method to modulate sulfur vacancies in MoS2. Considering polarity and the Hansen solubility parameter (HSP), three solvents were selected. Sulfur vacancies can be modulated by immersing MoS2 in each solvent, supported by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy analyses. The SAVE method can further expand its application in memory devices representing memristive performance and synaptic behaviors. We represented the charge transport mechanism of sulfur vacancy migration in MoS2. The non-destructive, scalable, and novel SAVE method controlling sulfur vacancies is expected to be a guideline for constructing a vacancy engineering system of TMDs.

Enhanced adhesion of functional layers by controlled electrografting of ethylenediamine on ITO for electrochemical immunoassay in microfluidic channel.

Two-electrode (2E) system of the interdigitated electrode array (IDA), which operates neither reference nor counter electrodes, has great potential to miniaturize multiplex immunoassay in a microfluidic chip for point-of-care testing. However, it is necessary to firmly immobilize the mediator layer on IDA made of indium tin oxide (ITO) which is chemically inert. It is important because the mediator determines the electrochemical potential in the 2E system, but the layer is easy to be detached during the washing processes of immunoassay. Here, we controlled the concentration of ethylenediamine (EDA) to generate a permeable and robust film to adhere to mediators on the ITO IDA chip. Electrooxidation of EDA yielded thin oligomeric ethyleneimine (OEI) film and it provided amine groups for immobilizing the mediator, poly(toluidine blue) (pTB), via common conjugation reaction. Despite repeated flows in the microchannel, which are essential for sensitive immunoassay, the pTB/OEI layer was hardly washed and still remained on the ITO IDA. Myoglobin was measured down to âˆ¼ pg/mL level. Therefore, the ITO IDA modified with the OEI film in the 2E system constituted a stable platform that withstands washing steps for sensitive electrochemical detection in the miniaturized immunoassay.

Controlled Integration of Interconnected Pores under Polymeric Surfaces for Low Adhesion and Antiscaling Performance.

Low-adhesive surfaces have been highlighted due to the potentials to mitigate fouling issues by preventing unwanted substances from adhering. Realizing superhydrophobicity with 3D surface structures/chemical modifiers or fabricating lubricant-assisted slippery surfaces has been demonstrated to realize low-adhesive surfaces. However, they still need to overcome the transition to Wenzel from Cassie states of droplets on 3D surface structures or the lubricant depletion issues of slippery surfaces for sustainable operations. Herein, we report the fabrication of low-adhesive polymeric surfaces, neither assisted by 3D surface structures/chemical modifiers nor lubricants, which is realized by embedding the interconnected pore networks underneath the top smooth surface using a water steaming method. The fabricated silicone surfaces exhibit low-adhesive properties due to the stress concentration effects generated by the subsurface-structured pores, favorable for easy detachment of the adherent from the surface. Our platform can be exploited to lower adhesion of superhydrophilic surfaces or to achieve ultralow-adhesive properties upon combination with superhydrophobicity. Finally, scale precipitation tests reveal 4.2 times lower scale accumulation of our low-adhesive polymeric surfaces than that in control samples.

Synergistic bactericidal effect of hot water with citric acid against Escherichia coli O157:H7 biofilm formed on stainless steel.

This study investigated the antimicrobial effect of hot water with citric acid against Escherichia coli O157:H7 biofilm on stainless steel (SS). Hot water (50, 60, or 70 °C) with 2% citric acid exhibited a synergistic bactericidal effect on the pathogen biofilm. It was revealed that hot water and citric acid combination induced sub-lethally injured cells. Additionally, mechanisms of the synergistic bactericidal effects of hot water with citric acid were identified through several approaches. In terms of biofilm matrix, hot water removes exopolysaccharides, a major component of extracellular polymeric substances (EPS), thereby increasing contact between surface cells and citric acid, resulting in a synergistic bactericidal effect. In terms of the cell itself, increased permeability of citric acid through cell membranes destructed by hot water promotes the inactivation of superoxide dismutase (SOD) in E. coli O157:H7, which induce synergistic generation of reactive oxygen species (ROS) which promote inactivation of cell by activating lipid peroxidation, resulting in destruction of the cell membrane. Therefore, it is interpreted that when hot water with citric acid is applied to E. coli O157:H7 biofilm, synergy effects on the biofilm matrix and cell itself have a complex interaction with each other, thus causing a dramatic synergistic bactericidal effect.

One-dimensional twisted and tubular structures of zinc oxide by semiconductor-catalyzed vapor-liquid-solid synthesis.

The exploration of unconventional catalysts for the vapor-liquid-solid synthesis of one-dimensional materials promises to yield new morphologies and functionality. Here, we show, for the model ZnO system, that unusual nanostructures can be produced via a semiconductor (Ge) catalyst. As well as the usual straight nanowires, we describe two other distinct morphologies: twisted nanowires and twisted nanotubes. The twisted nanotubes show large hollow cores and surprisingly high twisting rates, up to 9°/µm, that cannot be easily explained through the Eshelby twist model. A combination of ex situ and in situ transmission electron microscopy measurements suggest that the hollow core results from a competition between growth and etching at the Ge-ZnO interface during synthesis. The twisting rate is consistent with a softening of elastic rigidity. These results indicate that the use of unconventional, nonmetallic catalysts provides opportunities to synthesize unusual oxide nanostructures with potentially useful properties.

Does desflurane need more irrigating-pump pressure for the visibility in arthroscopic shoulder surgery than sevoflurane?

BACKGROUND: In arthroscopic shoulder surgery, a mechanical fluid-irrigation system is used to wash out blood from the joint. If used at high pressure, it can cause side effects such as fluid extravasation, leading to airway obstruction after surgery. Desflurane is prone to increasing sympathetic nerve activity and plasma catecholamine release more than another inhalation anesthetics. The objective of this study was to determine whether desflurane could increase in the irrigation pump pressure than sevoflurane in shoulder arthroscopy. METHODS: Patients were randomized into a sevoflurane group (group S) and a desflurane group (group D). Each included 20 patients. For group S, sevoflurane 1.2 MAC and intravenous remifentanil were administered for anesthesia maintenance. Group D received desflurane 1.2 MAC and intravenous remifentanil. Starting at 20 mmHg of pump pressure, the surgeon estimated the visibility of the surgical field (grade I-IV). After that, the pressure was freely adjusted by the surgeon to obtain clear vision with the arthroscope during the surgery. RESULTS: The maximum pressure of the mechanical water pump was higher in group D than group S (54.0 ± 6.8 mmHg vs. 48.9 ± 5.7 mmHg, P = 0.017), but the difference was not statistically significant at a significance level of 0.01. The arthroscopic visibility at the surgical site did not differ significantly between the two groups (P = 0.284). CONCLUSIONS: When desflurane is used in arthroscopic shoulder surgery, it does not require more pressure from the irrigating-fluid pump to secure a clear vision of the surgical site, compared to sevoflurane.

Successful wire-guided fiberoptic nasotracheal intubation in a patient with hemifacial microsomia - A case report.

BACKGROUND: Patients with hemifacial microsomia may have a difficult airway due to the accompanying mandibular deformity. Fiberoptic bronchoscope-guided intubation is commonly used method for difficult airway management. However, awake fiberoptic nasotracheal intubation has several disadvantages, including difficulty in advancement of the endotracheal tube (ETT) due to the resistance between the ETT and bronchoscope. Wire-guided fiberoptic nasotracheal intubation may help to overcome the drawbacks of the conventional method. CASE: An 18-year-old man with hemifacial microsomia was scheduled for double-jaw surgery. In preoperative evaluation, he had severe retrognathia and expected difficult airway. We successfully performed wire-guided fiberoptic nasotracheal intubation combined with high-flow nasal cannula and deep sedation without any complications. CONCLUSIONS: A guidewire may be useful, in case of difficultly in advancing the ETT or if a smaller tube is required, while performing intubation with FOB in patients with difficult airways.

Influence of preoperative hemoglobin A1c on early outcomes in patients with diabetes mellitus undergoing off-pump coronary artery bypass surgery.

OBJECTIVE: There seem to be modifiable components of diabetes in terms of glycemic control to improve surgical outcome. The aim of the study was to evaluate impact of preoperative glycated hemoglobin (HbA1c) level in patients with diabetes mellitus undergoing off-pump coronary bypass (OPCAB) on perioperative glycemic variability and short-term outcome. METHODS: Medical records of 703 patients with diabetes mellitus who underwent OPCAB from 2005 to 2017 were reviewed. The perioperative goal of glycemic control was <180 mg/dL. Patients were divided into 2 groups according to HbA1c level (<7.0% or ≥7.0%). Glycemic variability during surgery and up to 24 hours after surgery was assessed by coefficient of variation (CV). Primary outcome was defined as composite of postoperative permanent stroke, prolonged ventilation, deep sternal wound infection, renal failure, reoperation, and 30-day mortality. RESULTS: Incidence of composite of postoperative morbidity and mortality endpoints was greater in patients with HbA1c ≥7.0% (21% vs 15%, P = .041). Perioperative time-weighted average glucose concentration was also greater in patients with HbA1c ≥7.0%, whereas the CV did not show any difference. Multivariable logistic regression analysis revealed that congestive heart failure, chronic kidney disease, moderate mitral regurgitation or greater, preoperative hemoglobin level, and preoperative HbA1c ≥7.0% were independently associated with composite of postoperative morbidity and mortality, but perioperative CV and time-weighted average glucose ≥200 mg/dL were not. CONCLUSIONS: Increased preoperative HbA1c (≥7.0%) level reflecting long-term glycemic control seems to exert an adverse influence on outcome, whereas the influence of perioperative glycemic variables appear to be abrogated using a target glucose level of <180 mg/dL in patients with diabetes mellitus undergoing OPCAB.

Effects of Positive End-Expiratory Pressure on Pulmonary Oxygenation and Biventricular Function during One-Lung Ventilation: A Randomized Crossover Study.

Although the application of positive end-expiratory pressure (PEEP) can alter cardiopulmonary physiology during one-lung ventilation (OLV), these changes have not been clearly elucidated. This study assessed the effects of different levels of PEEP on biventricular function, as well as pulmonary oxygenation during OLV. Thirty-six lung cancer patients received one PEEP combination of six sequences, consisting of 0 (PEEP_0), 5 (PEEP_5), and 10 cmH2O (PEEP_10), using a crossover design during OLV. The ratio of arterial oxygen partial pressure to inspired oxygen fraction (P/F ratio), systolic and diastolic echocardiographic parameters were measured at 20 min after the first, second, and third PEEP. P/F ratio at PEEP_5 was significantly higher compared to PEEP_0 (p = 0.014), whereas the P/F ratio at PEEP_10 did not show significant differences compared to PEEP_0 or PEEP_5. Left ventricular ejection fraction (LV EF) and right ventricular fractional area change (RV FAC) at PEEP_10 (EF, p < 0.001; FAC, p = 0.001) were significantly lower compared to PEEP_0 or PEEP_5. RV E/E' (p = 0.048) and RV myocardial performance index (p < 0.001) at PEEP_10 were significantly higher than those at PEEP_0 or PEEP_5. In conclusion, increasing PEEP to 10 cmH2O decreased biventricular function, especially on RV function, with no further improvement on oxygenation compared to PEEP 5 cmH2O during OLV.

Evaluation of Validity and Reliability of a Revised Incontinence-Associated Skin Damage Severity Instrument (IASD.D.2) by 3 Groups of Nursing Staff.

PURPOSE: The purpose of this study was to evaluate a revised version of the Incontinence-Associated Skin Damage Severity instrument (IASD.D.2) using 3 different groups of nursing staff. Revisions to the instrument included renumbering 1 body area where incontinence-associated dermatitis (IAD) occurs into 2 areas (right and left), which raised the total possible score from 52 to 56, and defining the borders of the body areas. DESIGN: Observational, evaluative design. SAMPLE AND SETTING: Five clinical experts certified in wound, ostomy, and/or continence (WOC) nursing evaluated content validity. Evaluators were attendees at the WOC Nurses (WOCN) Society 2014 conference, hospital nurses, and nursing staff at a nursing home. Evaluators were attendees at the WOCN Society's 2014 National Conference, hospital nurses at a community hospital with Magnet designation, and nursing staff at a skilled nursing home in the Midwestern United States. The evaluator group comprised 198 conference attendees (all nurses; age 53 ± 8.2 years, mean ± SD), 67 hospital nurses (age 37 ± 11 years), and 34 nursing home nursing staff (age 45 ±13.8 years). The majority of evaluators (>75%) in each of the groups were female. METHODS: Clinical experts evaluated the content validity of the revised instrument. Evaluators scored 5 to 9 photographic cases using the revised instrument. Four of the cases were scored by all evaluators. The agreement of case scores among all evaluators was analyzed to assess interrater reliability. The scores of evaluators grouped by evaluators' self-identified skin color or nursing experience (<10 years vs ≥10 years) were also tested for differences. To provide evidence for criterion validity, the agreement of evaluators' scores with experts' scores (considered a "gold standard" in this study) was analyzed. RESULTS: The agreement of the IASD.D.2 scores among all evaluators within each group ranged from 0.74 to 0.79, suggesting good interrater reliability. The agreement of each group of evaluators with the experts for all case scores ranged from 0.82 to 0.85, suggesting good criterion validity. There was no significant difference in scores by evaluators' skin color or nursing experience. CONCLUSION: The revised IASD.D.2 has good content and criterion validity and interrater reliability. The instrument has potential to standardize reporting of IAD severity in research and clinical practice and assist communication about IAD among nursing staff.

Effects of dexmedetomidine in combination with fentanyl-based intravenous patient-controlled analgesia on pain attenuation after open gastrectomy in comparison with conventional thoracic epidural and fentanyl-based intravenous patient-controlled analgesia.

Background: This study was investigated the effects of dexmedetomidine in combination with fentanyl-based intravenous patient-controlled analgesia (IV-PCA) on pain attenuation in patients undergoing open gastrectomy in comparison with conventional thoracic epidural patient-controlled analgesia (E-PCA) and IV-PCA. Methods: One hundred seventy-one patients who planned open gastrectomy were randomly distributed into one of the 3 groups: conventional thoracic E-PCA (E-PCA group, n = 57), dexmedetomidine in combination with fentanyl-based IV-PCA (dIV-PCA group, n = 57), or fentanyl-based IV-PCA only (IV-PCA group, n = 57). The primary outcome was the postoperative pain intensity (numerical rating scale) at 3 hours after surgery, and the secondary outcomes were the number of bolus deliveries and bolus attempts, and the number of patients who required additional rescue analgesics. Mean blood pressure, heart rate, and adverse effects were evaluated as well. Results: One hundred fifty-three patients were finally completed the study. The postoperative pain intensity was significantly lower in the dIV-PCA and E-PCA groups than in the IV-PCA group, but comparable between the dIV-PCA group and the E-PCA group. Patients in the dIV-PCA and E-PCA groups needed significantly fewer additional analgesic rescues between 6 and 24 hours after surgery, and had a significantly lower number of bolus attempts and bolus deliveries during the first 24 hours after surgery than those in the IV-PCA group. Conclusions: Dexmedetomidine in combination with fentanyl-based IV-PCA significantly improved postoperative analgesia in patients undergoing open gastrectomy without hemodynamic instability, which was comparable to thoracic E-PCA. Furthermore, this approach could be clinically more meaningful owing to its noninvasive nature.

Optimizing gelling parameters of gellan gum for fibrocartilage tissue engineering.

Gellan gum is an attractive biomaterial for fibrocartilage tissue engineering applications because it is cell compatible, can be injected into a defect, and gels at body temperature. However, the gelling parameters of gellan gum have not yet been fully optimized. The aim of this study was to investigate the mechanics, degradation, gelling temperature, and viscosity of low acyl and low/high acyl gellan gum blends. Dynamic mechanical analysis showed that increased concentrations of low acyl gellan gum resulted in increased stiffness and the addition of high acyl gellan gum resulted in greatly decreased stiffness. Degradation studies showed that low acyl gellan gum was more stable than low/high acyl gellan gum blends. Gelling temperature studies showed that increased concentrations of low acyl gellan gum and CaCl2 increased gelling temperature and low acyl gellan gum concentrations below 2% (w/v) would be most suitable for cell encapsulation. Gellan gum blends were generally found to have a higher gelling temperature than low acyl gellan gum. Viscosity studies showed that increased concentrations of low acyl gellan gum increased viscosity. Our results suggest that 2% (w/v) low acyl gellan gum would have the most appropriate mechanics, degradation, and gelling temperature for use in fibrocartilage tissue engineering applications.