Assessment of the Suitability of the Fleischner Society Imaging Guidelines in Evaluating Chest Radiographs of COVID-19 Patients

BACKGROUND

The Fleischner Society established consensus guidelines for imaging in patients with coronavirus disease 2019 (COVID-19). We investigated the prevalence of pneumonia and the adverse outcomes by dividing groups according to the symptoms and risk factors of patients and assessed the suitability of the Fleischner society imaging guidelines in evaluating chest radiographs of COVID-19 patients.

METHODS

From February 2020 to May 2020, 685 patients (204 males, mean 58 ± 17.9 years) who were diagnosed with COVID-19 and hospitalized were included. We divided patients into four groups according to the severity of symptoms and presence of risk factors (age > 65 years and presence of comorbidities). The patient groups were defined as follows: group 1 (asymptomatic patients), group 2 (patients with mild symptoms without risk factors), group 3 (patients with mild symptoms and risk factors), and group 4 (patients with moderate to severe symptoms). According to the Fleischner society, chest imaging is not indicated for groups 1-2 but is indicated for groups 3-4. We compared the prevalence and score of pneumonia on chest radiographs and compare the adverse outcomes (progress to severe pneumonia, intensive care unit admission, and death) between groups.

RESULTS

Among the 685 COVID-19 patients, 138 (20.1%), 396 (57.8%), 102 (14.9%), and 49 (7.1%) patients corresponded to groups 1 to 4, respectively. Patients in groups 3-4 were significantly older and showed significantly higher prevalence rates of pneumonia (group 1-4: 37.7%, 51.3%, 71.6%, and 98%, respectively, P < 0.001) than those in groups 1-2. Adverse outcomes were also higher in groups 3-4 than in groups 1-2 (group 1-4: 8.0%, 3.5%, 6.9%, and 51%, respectively, P < 0.001). Patients with adverse outcomes in group 1 were initially asymptomatic but symptoms developed during follow-up. They were older (mean age, 80 years) and most of them had comorbidities (81.8%). Consistently asymptomatic patients had no adverse events.

CONCLUSION

The prevalence of pneumonia and adverse outcomes were different according to the symptoms and risk factors in COVID-19 patients. Therefore, as the Fleischner Society recommended, evaluation and monitoring of COVID-19 pneumonia using chest radiographs is necessary for old symptomatic patients with comorbidities.

Chiral electroluminescence from thin-film perovskite metacavities

Chiral light sources realized in ultracompact device platforms are highly desirable for various applications. Among active media used for thin-film emission devices, lead-halide perovskites have been extensively studied for photoluminescence due to their exceptional properties. However, up to date, there have been no demonstrations of chiral electroluminescence with a substantial degree of circular polarization (DCP) based on perovskite materials, being critical for the development of practical devices. Here, we propose a concept of chiral light sources based on a thin-film perovskite metacavity and experimentally demonstrate chiral electroluminescence with a peak DCP approaching 0.38. We design a metacavity created by a metal and a dielectric metasurface supporting photonic eigenstates with a close-to-maximum chiral response. Chiral cavity modes facilitate asymmetric electroluminescence of pairs of left and right circularly polarized waves propagating in the opposite oblique directions. The proposed ultracompact light sources are especially advantageous for many applications requiring chiral light beams of both helicities.

Kv7/KCNQ potassium channels in cortical hyperexcitability and juvenile seizure-related death in Ank2-mutant mice

Autism spectrum disorders (ASD) represent neurodevelopmental disorders characterized by social deficits, repetitive behaviors, and various comorbidities, including epilepsy. ANK2, which encodes a neuronal scaffolding protein, is frequently mutated in ASD, but its in vivo functions and disease-related mechanisms are largely unknown. Here, we report that mice with Ank2 knockout restricted to cortical and hippocampal excitatory neurons (Ank2-cKO mice) show ASD-related behavioral abnormalities and juvenile seizure-related death. Ank2-cKO cortical neurons show abnormally increased excitability and firing rate. These changes accompanied decreases in the total level and function of the Kv7.2/KCNQ2 and Kv7.3/KCNQ3 potassium channels and the density of these channels in the enlengthened axon initial segment. Importantly, the Kv7 agonist, retigabine, rescued neuronal excitability, juvenile seizure-related death, and hyperactivity in Ank2-cKO mice. These results suggest that Ank2 regulates neuronal excitability by regulating the length of and Kv7 density in the AIS and that Kv7 channelopathy is involved in Ank2-related brain dysfunctions.

An Empirical Study of Social Loafing Behavior among Public Officers in South Korea: The Role of Trust in a Supervisor, Perceived Organizational Support, and Perceived Organizational Politics

This study explored the effects of trust in a supervisor (TIS) on social loafing behaviors of employees. In addition, this study examined the mediating effect of perceived organizational support (POS) on the relationship between trust in a supervisor and employees' social loafing behaviors. It also examined the moderating effects of perceived organizational politics (POP) on the relationship between TIS and POS, TIS and social loafing behaviors, and POS and social loafing behaviors. Data were collected from local government employees in Korea, and the final sample was 260. Our results indicate that trust in a supervisor has indirect negative effects on social loafing behaviors mediated by POS. In addition, it was found that the effects of TIS on POS and POS on social loafing behaviors were moderated by POP. The results of this study contribute to the extant literature on social loafing behaviors. Moreover, the findings imply that political behaviors in organizations might induce social loafing behaviors.

RISK FACTORS FOR PUPILLARY OPTIC CAPTURE FOLLOWING SUTURELESS FLANGED INTRAOCULAR LENS FIXATION FOR INTRAOCULAR LENS DISLOCATION

PURPOSE

To identify risk factors for pupillary optic capture after sutureless flanged intraocular lens (IOL) fixation for IOL dislocation.

METHODS

This retrospective comparative study enrolled consecutive patients who underwent flanged IOL fixation using 25-gauge pars plana vitrectomy. One hundred twenty-six eyes (126 patients) were divided into two groups according to the presence or absence of pupillary optic capture. A swept-source anterior segment optical coherence tomography and a rotating Scheimpflug camera were used to analyze and compare surgical parameters, including axial length, anterior chamber depth, differences in scleral tunnel angle and length, and IOL tilt and decentration, between the two groups.

RESULTS

Compared with the nonpupillary optic capture group (106 eyes, 84.1%), the pupillary optic capture group (20 eyes, 15.9%) had larger differences in the nasal and temporal scleral tunnel angles and larger horizontal tilt (P < 0.05). Multivariate regression analysis demonstrated that these factors correlated with the occurrence of pupillary optic capture (P < 0.05).

CONCLUSION

To prevent pupillary optic capture after flanged IOL fixation, surgeons should avoid asymmetry in the angles of the nasal and temporal scleral tunnels, which causes horizontal IOL tilt and subsequent pupillary capture.

Refining Classification of Cholangiocarcinoma Subtypes via Proteogenomic Integration Reveals New Therapeutic Prospects

BACKGROUND & AIMS

Intrahepatic cholangiocarcinomas (iCCs) are characterized by their rarity, difficult diagnosis, and overall poor prognosis. The iCC molecular classification for developing precision medicine strategies was investigated.

METHODS

Comprehensive genomic, transcriptomic, proteomic, and phosphoproteomic analyses were performed on treatment-naïve tumor samples from 102 patients with iCC who underwent surgical resection with curative intent. An organoid model was constructed for testing therapeutic potential.

RESULTS

Three clinically supported subtypes (stem-like, poorly immunogenic, and metabolism) were identified. NCT-501 (aldehyde dehydrogenase 1 family member A1 [ALDH1A1] inhibitor) exhibited synergism with nanoparticle albumin-bound-paclitaxel in the organoid model for the stem-like subtype. The oncometabolite dysregulations were associated with different clinical outcomes in the stem-like and metabolism subtypes. The poorly immunogenic subtype harbors the non-T-cell tumor infiltration. Integrated multiomics analysis not only reproduced the 3 subtypes but also showed heterogeneity in iCC.

CONCLUSIONS

This large-scale proteogenomic analysis provides information beyond that obtained with genomic analysis, allowing the functional impact of genomic alterations to be discerned. These findings may assist in the stratification of patients with iCC and in developing rational therapeutic strategies.

High light extraction performance using evanescent waves for top emission OLED applications with thin film encapsulation

We report high light extraction from the top emission OLED (TEOLED) device structure by improving mainly the waveguide mode loss in the atomic layer deposition processed thin film encapsulation (TFE) layer. A novel structure incorporating the light extraction concept using evanescent waves and the hermetic encapsulation of a TEOLED device is presented here. When the TEOLED device is fabricated using the TFE layer, a substantial amount of generated light is trapped inside the device due to the difference in refractive index (RI) between the capping layer (CPL) and the aluminum oxide (Al₂O₃) layer. By inserting a low RI layer at the interface between the CPL and Al₂O₃, the direction of the internal reflected light is changed by the evanescent waves. The high light extraction with the low RI layer is attributed to the presence of evanescent waves and an electric field in the low RI layer. The novel fabricated TFE structure, CPL/ low RI layer/ Al₂O₃/ polymer/ Al₂O₃, is reported here. The current efficiency of the fabricated blue TEOLED device using this low RI layer is improved by about 23% and the blue index value is enhanced by about 26%. This new approach for light extraction will be applicable to future encapsulation technology for flexible optoelectronic devices.

Interfacial modification in perovskite-based tandem solar cells

With photovoltaic performance of metal halide perovskite-based solar cells skyrocketing to approximately 26% and approaching the theoretical Shockley-Queisser limit of single junction solar cells, researchers are now exploring multi-junction tandem solar cells that use perovskite materials to achieve high efficiency next-generation photovoltaics. Various types of bottom subcells, including silicon solar cells used commercially in industry, chalcogenide thin film cells, and perovskite cells, have been combined with perovskite top subcells on the strength of facile fabrication methods based on solution processes. However, owing to the nature that photovoltages of the subcells are added up and the structure containing numerous layers, interfacial issues that cause open-circuit voltage (V_OC) deficit need to be handled carefully. In addition, morphological issues or process compatibility make it difficult to fabricate solution-processed perovskite top cells. In this paper, we summarize and review the fundamentals and strategies to overcome interfacial issues in tandem solar cells for high efficiency and stability confronting this field.

Antidepressant effects of p-coumaric acid isolated from Vaccinium bracteatum leaves extract on chronic restraint stress mouse model and antagonism of serotonin 6 receptor in vitro

BACKGROUND

Vaccinium bracteatum Thunb. leaves (VBL) are used in traditional herbal medicines to treat various biological diseases. p-coumaric acid (CA), the main active component of VBL, has neuroprotective effects against corticosterone-induced damage in vitro. However, the effects of CA on immobility induced by chronic restraint stress (CRS) in a mouse model and 5-HT receptor activity have not been investigated.

HYPOTHESIS/PURPOSE

We investigated the antagonistic effects of VBL, NET-D1602, and the three components of Gαs protein-coupled 5-HT receptors. Additionally, we identified the effects and mechanism of action of CA, the active component of NET-D1602, in the CRS-exposed model.

METHODS

For in vitro analyses, we used 1321N1 cells stably expressing human 5-HT₆ receptors and CHO-K1 expressing human 5-HT₄ or 5-HT₇ receptors cell lines to study the mechanism of action. For in vivo analyses, CRS-exposed mice were orally administered CA (10, 50, or 100 mg/kg) daily for 21 consecutive days. The effects of CA were analyzed by assessing behavioral changes using a forced swim test (FST), measuring levels of hypothalamic-pituitary-adrenal (HPA) axis-related hormones in ntial therapeutic effects as 5-HT6 receptor antagonists for neurodegenerative diseases and depressioserum, and acetylcholinesterase (AChE), monoamines, including 5-HT, dopamine, and norepinephrine, using enzyme-linked immunosorbent assay kits. The underlying molecular mechanisms of the serotonin transporter (SERT), monoamine oxidase A (MAO-A), and extracellular signal-regulated kinase (ERK)/protein kinase B (Akt)/mTORC1 signaling were detected using western blotting.

RESULTS

CA was confirmed to be an active component in the antagonistic effects of NET-D1602 on 5-HT₆ receptor activity through decreases in cAMP and ERK1/2 phosphorylation. Moreover, CRS-exposed mice treated with CA showed a significantly reduced immobility time in the FST. CA also significantly decreased corticosterone, corticotropin-releasing hormone (CRH), and adrenocorticotropic hormone (ACTH) levels. CA enhanced 5-HT, dopamine, and norepinephrine levels in the hippocampus (HC) and prefrontal cortex (PFC) but decreased MAO-A and SERT protein levels. Similarly, CA significantly upregulated the ERK, Ca²⁺/calmodulin-dependent protein kinase II (CaMKII), Akt/mTOR/p70S6K/S6 signaling pathways in both HC and the PFC.

CONCLUSION

CA contained in NET-D1602 may play the antidepressant effects against CRS-induced depression-like mechanism and the selective antagonist effect of 5-HT₆ receptor.

CT analysis of thoracolumbar body composition for estimating whole-body composition

BACKGROUND

To evaluate the correlation between single- and multi-slice cross-sectional thoracolumbar and whole-body compositions.

METHODS

We retrospectively included patients who underwent whole-body PET-CT scans from January 2016 to December 2019 at multiple institutions. A priori-developed, deep learning-based commercially available 3D U-Net segmentation provided whole-body 3D reference volumes and 2D areas of muscle, visceral fat, and subcutaneous fat at the upper, middle, and lower endplate of the individual T1-L5 vertebrae. In the derivation set, we analyzed the Pearson correlation coefficients of single-slice and multi-slice averaged 2D areas (waist and T12-L1) with the reference values. We then built prediction models using the top three correlated levels and tested the models in the validation set.

RESULTS

The derivation and validation datasets included 203 (mean age 58.2 years; 101 men) and 239 patients (mean age 57.8 years; 80 men). The coefficients were distributed bimodally, with the first peak at T4 (coefficient, 0.78) and the second peak at L2-3 (coefficient 0.90). The top three correlations in the abdominal scan range were found for multi-slice waist averaging (0.92) and single-slice L3 and L2 (0.90, each), while those in the chest scan range were multi-slice T12-L1 averaging (0.89), single-slice L1 (0.89), and T12 (0.86). The model performance at the top three levels for estimating whole-body composition was similar in the derivation and validation datasets.

CONCLUSIONS

Single-slice L2-3 (abdominal CT range) and L1 (chest CT range) analysis best correlated with whole-body composition around 0.90 (coefficient). Multi-slice waist averaging provided a slightly higher correlation of 0.92.

Identifying Key Residues in Lysine Decarboxylase for Soluble Expression Using Consensus Design Soluble Mutant Screening (ConsenSing)

Although recent advances in deep learning approaches for protein engineering have enabled quick prediction of hot spot residues improving protein solubility, the predictions do not always correspond to an actual increase in solubility under experimental conditions. Therefore, developing methods that rapidly confirm the linkage between computational predictions and empirical results is essential to the success of improving protein solubility of target proteins. Here, we present a simple hybrid approach to computationally predict hot spots possibly improving protein solubility by sequence-based analysis and empirically explore valuable mutants using split GFP as a reporter system. Our approach, Consensus design Soluble Mutant Screening (ConsenSing), utilizes consensus sequence prediction to find hot spots for improvement of protein solubility and constructs a mutant library using Darwin assembly to cover all possible mutations in one pot but still keeps the library as compact as possible. This approach allowed us to identify multiple mutants of Escherichia coli lysine decarboxylase, LdcC, with substantial increases in soluble expression. Further investigation led us to pinpoint a single critical residue for the soluble expression of LdcC and unveiled its mechanism for such improvement. Our approach demonstrated that following a protein's natural evolutionary path provides insights to improve protein solubility and/or increase protein expression by a single residue mutation, which can significantly change the profile of protein solubility.

Molecular orientation-dependent energetic shifts in solution-processed non-fullerene acceptors and their impact on organic photovoltaic performance

The non-fullerene acceptors (NFAs) employed in state-of-art organic photovoltaics (OPVs) often exhibit strong quadrupole moments which can strongly impact on material energetics. Herein, we show that changing the orientation of Y6, a prototypical NFA, from face-on to more edge-on by using different processing solvents causes a significant energetic shift of up to 210 meV. The impact of this energetic shift on OPV performance is investigated in both bilayer and bulk-heterojunction (BHJ) devices with PM6 polymer donor. The device electronic bandgap and the rate of non-geminate recombination are found to depend on the Y6 orientation in both bilayer and BHJ devices, attributed to the quadrupole moment-induced band bending. Analogous energetic shifts are also observed in other common polymer/NFA blends, which correlates well with NFA quadrupole moments. This work demonstrates the key impact of NFA quadruple moments and molecular orientation on material energetics and thereby on the efficiency of high-performance OPVs.

Abstract 328: Acetylation regulates the oncogenic functions of PRMT5

Protein arginine methyltransferase 5 (PRMT5) is an enzyme responsible for symmetric arginine methylation, which governs multiple crucial cellular events. PRMT5 expression and activity are dysregulated in many malignancies. PRMT5 dynamically shuttles between the cytosol and nucleus, and different subcellular localizations of PRMT5 imposes distinct cellular functions. However, the biological significance and underlying regulatory mechanism of PRMT5 translocation remain elusive. Herein, we found that PRMT5 acetylation/deacetylation status is a major determinant of its translocation and oncogenic function. PRMT5 acetylation not only drives its cytoplasmic localization but also enhances its methyltransferase activity, promoting cancer cell proliferation. On the other hand, PRMT5 deacetylation translocates PRMT5 into nucleus, to protect cells under the stress condition. Our current findings demonstrate that the acetylation/deacetylation-dependent subcellular localization of PRMT5 is a key regulator of its oncogenic properties.

Citation Format: Tam Thuy Lu Vo, Yen Thi Do, Thi Tuyet Mai Pham, So-Jin Shin, Jin Young Kim, Seungmee Lee, Eunyoung Ha, Ji Hae Seo. Acetylation regulates the oncogenic functions of PRMT5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 328.

Abstract 2123: Glycine decarboxylase regulates renal carcinoma progression via interferon stimulated gene factor 3-mediated pathway

Glycine decarboxylase (GLDC) is a mitochondrial enzyme that mediates the degradation of glycine as part of the glycine cleavage system; it is implicated as a tumor suppressor in hepatocellular carcinoma but as an oncogene in the lung cancer. Although GLDC expression in the kidney is second highest next to the liver, very little is known as to the role of GLDC in the kidney. Thus, this study was designed to determine the role of GLDC in the renal carcinoma. We found markedly increased expressions of GLDC in patients with renal cell carcinoma (RCC) classified as poor-risk group based on the Memorial Sloan Kettering Cancer Center prognostic model. In vitro studies revealed that cellular proliferation, colony formation, and migration were decreased in GLDC-deficient renal carcinoma cells while those were increased in GLDC-overexpressing renal carcinoma cells. In vivo xenograft studies with GLDC-deficient and -overexpressing cells also revealed that tumor sizes were noticeably decreased in GLDC-deficient cell-injected mice while those were increased in GLDC-overexpressing cell-injected mice. Mechanistically, we found GLDC regulates renal carcinoma progression via interferon (IFN) stimulated gene factor 3 (ISGF3)-mediated pathway. Poly-IC induced mRNA expression of IFN-α more strongly in GLDC-deficient cells. Expressions of IRF9 and STAT2 were increased in GLDC-deficient cells while those were decreased in GLDC-overexpressing cells. Interferon-responsive genes (IFIT1, IFI44, IFI44L, and IFI27) were also regulated by GLDC as evidenced by increased mRNA expressions in GLDC-deficient cells and increased mRNA expressions in GLDC-overexpressing cells. Knock-down of IRF9 and STAT2 in GLDC-deficient cells reversed decreased cellular proliferation, colony formation, and migration. In summary, the data in this study indicates that GLDC regulates renal carcinoma progression via ISFG3-medated pathway and lay a scientific foundation that could support a therapeutic strategy that targets GLDC for the treatment of renal carcinoma.

Citation Format: Jin Young Kim, Mai Thi Tuyet Pham, Byung Hoon Kim, Ji Hae Seo, Sojin Shin, Eunyoung Ha. Glycine decarboxylase regulates renal carcinoma progression via interferon stimulated gene factor 3-mediated pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2123.

Defining regorafenib as a senomorphic drug: therapeutic potential in the age-related lung disease emphysema

Senescence, a hallmark of aging, is a factor in age-related diseases (ARDs). Therefore, targeting senescence is widely regarded as a practicable method for modulating the effects of aging and ARDs. Here, we report the identification of regorafenib, an inhibitor of multiple receptor tyrosine kinases, as a senescence-attenuating drug. We identified regorafenib by screening an FDA-approved drug library. Treatment with regorafenib at a sublethal dose resulted in effective attenuation of the phenotypes of βPIX knockdown- and doxorubicin-induced senescence and replicative senescence in IMR-90 cells; cell cycle arrest, and increased SA-β-Gal staining and senescence-associated secretory phenotypes, particularly increasing the secretion of interleukin 6 (IL-6) and IL-8. Consistent with this result, slower progression of βPIX depletion-induced senescence was observed in the lungs of mice after treatment with regorafenib. Mechanistically, the results of proteomics analysis in diverse types of senescence indicated that growth differentiation factor 15 and plasminogen activator inhibitor-1 are shared targets of regorafenib. Analysis of arrays for phospho-receptors and kinases identified several receptor tyrosine kinases, including platelet-derived growth factor receptor α and discoidin domain receptor 2, as additional targets of regorafenib and revealed AKT/mTOR, ERK/RSK, and JAK/STAT3 signaling as the major effector pathways. Finally, treatment with regorafenib resulted in attenuation of senescence and amelioration of porcine pancreatic elastase-induced emphysema in mice. Based on these results, regorafenib can be defined as a novel senomorphic drug, suggesting its therapeutic potential in pulmonary emphysema.

In vivo photoacoustic monitoring of vasoconstriction induced by acute hyperglycemia

Postprandial hyperglycemia, blood glucose spikes, induces endothelial dysfunction, increasing cardiovascular risks. Endothelial dysfunction leads to vasoconstriction, and observation of this phenomenon is important for understanding acute hyperglycemia. However, high-resolution imaging of microvessels during acute hyperglycemia has not been fully developed. Here, we demonstrate that photoacoustic microscopy can noninvasively monitor morphological changes in blood vessels of live animals' extremities when blood glucose rises rapidly. As blood glucose level rose from 100 to 400 mg/dL following intraperitoneal glucose injection, heart/breath rate, and body temperature remained constant, but arterioles constricted by approximately -5.7 ± 1.1% within 20 min, and gradually recovered for another 40 min. In contrast, venular diameters remained within about 0.6 ± 1.5% during arteriolar constriction. Our results experimentally and statistically demonstrate that acute hyperglycemia produces transitory vasoconstriction in arterioles, with an opposite trend of change in blood glucose. These findings could help understanding vascular glucose homeostasis and the relationship between diabetes and cardiovascular diseases.

Characterization of various tandem solar cells: Protocols, issues, and precautions

In the search for a more efficient solar cell, various types of tandem solar cells (TSCs) have been actively developed worldwide as the performances of the single junction solar cells approach their theoretical limits. Meanwhile, various materials and structures are adopted in TSCs, which makes their characterizations and comparison difficult. Along with the classical monolithic TSC, which exhibits two electrical contacts, devices with three or four electrical contacts have been widely studied as a more performing alternative of commercialized solar cells. For a fair and accurate evaluation of the device performance of TSCs, understanding the effectiveness and limitations of the characterization of the different types of TSCs is crucial. In this paper, we summarize various types of TSCs and discuss their characterization methods.

High-sensitivity NH3 gas sensor using pristine graphene doped with CuO nanoparticles

A highly sensitive and selective NH₃ gas sensor was developed based on single-layer pristine graphene doped with copper(II) oxide (CuO) nanoparticles of a specific size. High-quality single-layer graphene was grown using chemical vapor deposition. Approximately 15 nm-sized CuO colloidal nanoparticles were fabricated by a microwave-assisted thermal method using copper acetate as the precursor, and dimethylformamide as the reducing and stabilizing agent. Pristine graphene was doped with an aqueous suspension of CuO nanoparticles at a coating speed of 1500 rpm using a simple spin coater. CuO nanoparticle doping induces changes in the electronic properties of graphene; in particular, p-type doping significantly altered graphene resistivity in the presence of NH₃ gas. Upon exposure of the pristine graphene surface to NH₃ gas, NH₃ reacted with O₂^-/ O^-/ O^2- species on the graphene surface and released electrons into graphene. This caused a change in the concentration of charge carriers in the valence channel of graphene and an increase in graphene resistivity, facilitating real-time NH₃ monitoring with quick response and rapid recovery at 25 ℃ and ~ 55% relative humidity. Our results indicated that graphene doped with ~ 15 nm-sized CuO nanoparticles can sense NH₃ gas selectively with a resistivity response of ~ 83%. Moreover, the sensor exhibited good reusability, fast response (~ 19 s), and rapid recovery (~ 277 s) with a detection limit of 0.041 ppm and a relative standard deviation of 0.76%.

Can online learning be a reliable alternative to nursing students' learning during a pandemic? - A systematic review and meta-analysis

OBJECTIVES

To compare online learning with traditional face-to-face and blended learning, based on randomized controlled trials, to determine the impact of online learning on nursing students' learning outcomes.

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

A systematic search was conducted via English (PubMed, ERIC, Embase, CENTRAL, and CINAHL) and Korean databases (RISS, DBpia, and KISS).

REVIEW METHODS

Studies published up to the first week of April 2022 were reviewed with a focus on the participants, intervention, comparison, outcome, and study design format. Following a primary screening of titles and abstracts, and secondary screening of full texts, 10 randomized controlled trial studies were selected, of which eight were included in the meta-analysis. Two researchers independently reviewed the literature, and the final selection was made in consensus.

RESULTS

Online learning had a statistically significant positive effect on nursing students' knowledge, compared with no educational intervention (standardized mean difference (SMD) = 1.63; 95 % confidence interval (CI): 1.31 to 1.95). However, there was no significant difference in the impact of online learning on knowledge compared with blended learning (SMD = -0.14; 95 % CI: -0.70 to 0.41) and face-to-face learning (SMD = 0.37; 95 % CI: -0.32 to 1.06). Furthermore, compared with blended learning (SMD = -0.18; 95 % CI: -0.43 to 0.06) and face-to-face learning (SMD = 0.05; 95 % CI: -0.31 to 0.41), there was no significant difference in the impact of online learning on attitudes toward learning.

CONCLUSIONS

Online learning in nursing education is not significantly different from blended or face-to-face learning in terms of its impact on knowledge acquisition and attitudes toward learning. The results of this review and meta-analysis highlight the need for selective application of learning methods, taking into account learning environments as well as curricular subjects and topics.

Growth inhibition by fusidic acid in cervical, thyroid, and breast carcinoma cell lines

OBJECTIVE

We investigated the effects of fusidic acid (FA) on human cervical, thyroid, and breast carcinoma cell lines to determine the potential usefulness of FA in cancer treatment.

METHODS

Six cancer cell lines (cervical cancer: Caski, HeLa; thyroid cancer: 8505C, TPC1; and breast cancer: MCF-7, MDA-MB-231) were treated with FA. Furthermore the changes in cell growth, cell cycle duration, and extent of apoptosis were analyzed.

RESULTS

After FA treatment, the cancer cells showed a decrease in growth rate. In the cell death assay, the cell populations were similar in each cell type after treatment with FA, indicating that growth inhibition by FA was not related to the induction of apoptosis. FA induced cell cycle arrest at a dose that inhibited growth rate, which varied in different cell types. G0/G1 phase arrest occurs in breast cancer, S phase arrest in 8505C thyroid cancer, and G2/M phase arrest in cervical cancer. These results indicate that FA reduces growth rates by inducing cell cycle arrest.

CONCLUSION

FA treatment can interfere with cell proliferation by inducing cell cycle arrest in human cervical, thyroid, and breast carcinoma cell lines. Thus, FA can be useful in treating human cervical, thyroid, and breast carcinomas.

Simplified Y6-Based Nonfullerene Acceptors: In-Depth Study on Molecular Structure-Property Relation, Molecular Dynamics Simulation, and Charge Dynamics

Two new Y6 derivatives of symmetrical YBO-2O and asymmetrical YBO-FO nonfullerene acceptors (NFAs) are prepared with a simplified synthetic procedure by incorporating octyl and fluorine substituents onto the terminal 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (INCN) moiety. By moving the alkyl substituents on the Y6 core to the terminal INCN moiety, the lowest unoccupied molecular orbital of the YBO NFAs increases without decreasing solubility, resulting in high open-circuit voltages of the devices. Molecular dynamics simulation shows that YBO-2O/-FO preferentially form core-core and terminal-terminal dimeric interactions, demonstrating their tighter packing structure and higher electron mobility than Y6, which is consistent with 2D grazing incidence X-ray scattering and space charge limited current measurements. In blend films, the hole transfer (HT) from YBO-2O/-FO to the polymer donor PM6 is studied in detail by transient absorption spectroscopy, demonstrating efficient HT from YBO-FO to PM6 with their suitable energy level alignment. Despite the simplified synthesis, YBO-FO demonstrates photovoltaic performance similar to that of Y6, exhibiting a power conversion efficiency of 15.01%. Overall, this design strategy not only simplifies the synthetic procedures but also adjusts the electrical properties by modifying the intermolecular packing and energy level alignment, suggesting a novel simplified molecular design of Y6 derivatives.

Deep Learning With Chest Radiographs for Making Prognoses in Patients With COVID-19: Retrospective Cohort Study

BACKGROUND

An artificial intelligence (AI) model using chest radiography (CXR) may provide good performance in making prognoses for COVID-19.

OBJECTIVE

We aimed to develop and validate a prediction model using CXR based on an AI model and clinical variables to predict clinical outcomes in patients with COVID-19.

METHODS

This retrospective longitudinal study included patients hospitalized for COVID-19 at multiple COVID-19 medical centers between February 2020 and October 2020. Patients at Boramae Medical Center were randomly classified into training, validation, and internal testing sets (at a ratio of 8:1:1, respectively). An AI model using initial CXR images as input, a logistic regression model using clinical information, and a combined model using the output of the AI model (as CXR score) and clinical information were developed and trained to predict hospital length of stay (LOS) ≤2 weeks, need for oxygen supplementation, and acute respiratory distress syndrome (ARDS). The models were externally validated in the Korean Imaging Cohort of COVID-19 data set for discrimination and calibration.

RESULTS

The AI model using CXR and the logistic regression model using clinical variables were suboptimal to predict hospital LOS ≤2 weeks or the need for oxygen supplementation but performed acceptably in the prediction of ARDS (AI model area under the curve [AUC] 0.782, 95% CI 0.720-0.845; logistic regression model AUC 0.878, 95% CI 0.838-0.919). The combined model performed better in predicting the need for oxygen supplementation (AUC 0.704, 95% CI 0.646-0.762) and ARDS (AUC 0.890, 95% CI 0.853-0.928) compared to the CXR score alone. Both the AI and combined models showed good calibration for predicting ARDS (P=.079 and P=.859).

CONCLUSIONS

The combined prediction model, comprising the CXR score and clinical information, was externally validated as having acceptable performance in predicting severe illness and excellent performance in predicting ARDS in patients with COVID-19.