Click-To-Twist Strategy To Build Blue-to-Green Emitters: Bulky Triazoles for Electronically Tunable and Thermally Activated Delayed Fluorescence.

Discovery of a new chemical moiety is the foundation to build new functional materials. For charge-transfer-type thermally activated delayed fluorescence (TADF) emitters, donor, acceptor, and π-spacer are the three key structural components. We invented a "click-to-twist" strategy to prepare a triazole-based acceptor unit that allows for a systematic modulation of the electronic and steric properties to control the excited-state photophysics. Taking the modular approach, six different emitters were prepared by varying the donor strength and π-spacer sterics for mix-and-match. These materials display deep blue to sky blue emissions in solutions, as well as apparent TADF characteristics in doped films. Organic light emitting diodes fabricated with these new TADF materials exhibit high external quantum efficiencies of up to 20.7% and maximum luminance of 6823 cd m-2. Building upon an intuitive and operationally straightforward method to build sterically congested molecules, this work showcases a new strategy to diversify TADF emitters by a mechanism-based design and modular synthesis.

Validation of deep-learning-based triage and acuity score using a large national dataset.

AIM: Triage is important in identifying high-risk patients amongst many less urgent patients as emergency department (ED) overcrowding has become a national crisis recently. This study aims to validate that a Deep-learning-based Triage and Acuity Score (DTAS) identifies high-risk patients more accurately than existing triage and acuity scores using a large national dataset. METHODS: We conducted a retrospective observational cohort study using data from the Korean National Emergency Department Information System (NEDIS), which collected data on visits in real time from 151 EDs. The NEDIS data was split into derivation data (January 2014-June 2016) and validation data (July-December 2016). We also used data from the Sejong General Hospital (SGH) for external validation (January-December 2017). We predicted in-hospital mortality, critical care, and hospitalization using initial information of ED patients (age, sex, chief complaint, time from symptom onset to ED visit, arrival mode, trauma, initial vital signs and mental status as predictor variables). RESULTS: A total of 11,656,559 patients were included in this study. The primary outcome was in-hospital mortality. The Area Under the Receiver Operating Characteristic curve (AUROC) and Area Under the Precision and Recall Curve (AUPRC) of DTAS were 0.935 and 0.264. It significantly outperformed Korean triage and acuity score (AUROC:0.785, AUPRC:0.192), modified early warning score (AUROC:0.810, AUPRC:0.116), logistic regression (AUROC:0.903, AUPRC:0.209), and random forest (AUROC:0.910, AUPRC:0.179). CONCLUSION: Deep-learning-based Triage and Acuity Score predicted in-hospital mortality, critical care, and hospitalization more accurately than existing triages and acuity, and it was validated using a large, multicenter dataset.

An Algorithm Based on Deep Learning for Predicting In-Hospital Cardiac Arrest.

BACKGROUND: In-hospital cardiac arrest is a major burden to public health, which affects patient safety. Although traditional track-and-trigger systems are used to predict cardiac arrest early, they have limitations, with low sensitivity and high false-alarm rates. We propose a deep learning-based early warning system that shows higher performance than the existing track-and-trigger systems. METHODS AND RESULTS: This retrospective cohort study reviewed patients who were admitted to 2 hospitals from June 2010 to July 2017. A total of 52 131 patients were included. Specifically, a recurrent neural network was trained using data from June 2010 to January 2017. The result was tested using the data from February to July 2017. The primary outcome was cardiac arrest, and the secondary outcome was death without attempted resuscitation. As comparative measures, we used the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPRC), and the net reclassification index. Furthermore, we evaluated sensitivity while varying the number of alarms. The deep learning-based early warning system (AUROC: 0.850; AUPRC: 0.044) significantly outperformed a modified early warning score (AUROC: 0.603; AUPRC: 0.003), a random forest algorithm (AUROC: 0.780; AUPRC: 0.014), and logistic regression (AUROC: 0.613; AUPRC: 0.007). Furthermore, the deep learning-based early warning system reduced the number of alarms by 82.2%, 13.5%, and 42.1% compared with the modified early warning system, random forest, and logistic regression, respectively, at the same sensitivity. CONCLUSIONS: An algorithm based on deep learning had high sensitivity and a low false-alarm rate for detection of patients with cardiac arrest in the multicenter study.

Deep Learning in the Medical Domain: Predicting Cardiac Arrest Using Deep Learning.

With the wider adoption of electronic health records, the rapid response team initially believed that mortalities could be significantly reduced but due to low accuracy and false alarms, the healthcare system is currently fraught with many challenges. Rule-based methods (e.g., Modified Early Warning Score) and machine learning (e.g., random forest) were proposed as a solution but not effective. In this article, we introduce the DeepEWS (Deep learning based Early Warning Score), which is based on a novel deep learning algorithm. Relative to the standard of care and current solutions in the marketplace, there is high accuracy, and in the clinical setting even when we consider the number of alarms, the accuracy levels are superior.

The in vivo transformation and pharmacokinetic properties of a liquid crystalline drug delivery system.

A liquid crystalline (LC) system, composed of phosphatidylcholine, sorbitan monoleate, and tocopherol acetate, was investigated to understand the in vivo transformation after subcutaneous injection, coupled with the physicochemical and pharmacokinetic properties of the formulation. The rat model was utilized to monitor a pseudo-time course transformation from a precursor LC formulation to the LC matrix, coupled with the blood concentration profiles of the formulations containing leuprolide acetate. Three formulations that result in the HII phase, demonstrating dissimilar in vitro release profiles, were used. The formulation showing the highest AUC, Cmax and Tmax, also displayed the greatest release rate in vitro, the lowest viscosity (LC matrix), and an earlier transformation (LC precursor to matrix) in vivo. A potential link between viscosity, phase transformation, and drug release properties of a liquid crystalline system is described.

Formulation and characterization of a liquid crystalline hexagonal mesophase region of phosphatidylcholine, sorbitan monooleate, and tocopherol acetate for sustained delivery of leuprolide acetate.

Although liquid crystal (LC) systems have been studied before, their utility in drug delivery applications has not been explored in depth. This study examined the development of a 1-month sustained release formulation of leuprolide acetate using an in situ-forming LC matrix. The phase progression upon water absorption was tested through construction of ternary phase diagrams of phosphatidylcholine, sorbitan monooleate, and tocopherol acetate (TA) at increasing water content. Small angle X-ray scattering revealed the presence of lamellar and hexagonal mesophases. The physicochemical characteristics and in vitro drug release were evaluated as a function of the ternary component ratio and its resultant phase behavior. Formulations with increased water uptake capacity displayed greater drug release and enhanced erodability. Removal of TA resulted in increased water uptake capacity and drug release, where 8% (w/w) TA was determined as the critical concentration threshold for divergence of release profiles. In conclusion, characterization of the resultant HII mesophase region provided information of the impact the individual components have on the physicochemical properties and potential drug release mechanisms. This high mitigating impact of TA on drug release indicates the use of TA as a tailoring agent, broadening the therapeutic applications of this LC system.

Overexpression of malic enzyme in the larval stage extends Drosophila lifespan.

Metabolic modifications during the developmental period can extend longevity. We found that malic enzyme (Men) overexpression during the larval period lengthened the lifespan of Drosophila. Men overexpression by S106-GeneSwitch-Gal4 driver increased pyruvate content and NADPH/NADP(+) ratio but reduced triglyceride, glycogen, and ATP levels in the larvae. ROS levels increased unexpectedly in Men-overexpressing larvae. Interestingly, adults exposed to larval Men-overexpression maintained ROS tolerance with enhanced expression levels of glutathione-S-transferase D2 and thioredoxin-2. Our results suggest that metabolic changes mediated by Men during development might be related to the control of ROS tolerance and the longevity of Drosophila.

Chitosan-based hybrid nanocomplex for siRNA delivery and its application for cancer therapy.

PURPOSE: Chitosan, a natural and biocompatible cationic polymer, is an attractive carrier for small interfering RNA (siRNA) delivery. The purpose of this study was to develop a chitosan-based hybrid nanocomplex that exhibits enhanced physical stability in the bloodstream compared with conventional chitosan complexes. Hybrid nanocomplexes composed of chitosan, protamine, lecithin, and thiamine pyrophosphate were prepared for systemic delivery of survivin (SVN) siRNA. METHODS: Physicochemical properties of the nanoparticles including mean diameters and zeta potentials were characterized, and target gene silencing and cellular uptake efficiencies of the siRNA nanocomplexes in prostate cancer cells (PC-3 cells) were measured. In vivo tumor targetability and anti-tumor efficacy by systemic administration were assessed in a PC-3 tumor xenograft mouse model by near-infrared fluorescence (NIRF) imaging and tumor growth monitoring, respectively. RESULTS: Mean diameters of the SVN siRNA-loaded hybrid nanocomplex (GP-L-CT) were less than 200 nm with a positive zeta potential value in water and were maintained without aggregation in culture media and 50% fetal bovine serum. SVN expression in PC-3 cells was reduced to 21.9% after treating with GP-L-CT. The tumor targetability and growth inhibitory efficacies of GP-L-CT supported the use of this novel hybrid nanocomplex as a cancer therapeutic and as a theranostic system for systemic administration. CONCLUSIONS: A chitosan-based hybrid nanocomplex was successfully developed for the systemic delivery of SVN siRNA, which could serve as an alternative to cationic polymeric nanoparticles that are unstable in serum.

Over-expression of human clusterin increases stress resistance and extends lifespan in Drosophila melanogaster.

Clusterin is a disulfide-linked heterodimeric glycoprotein that has been implicated in a variety of biological processes. Its expression has been shown to be elevated during cellular senescence and normal aging, but it is uncertain whether clusterin protects against aging or whether its expression is a consequence of aging. To investigate the functions of clusterin during organismal aging, we established transgenic Drosophila alleles to induce the expression of the secretory form of human clusterin (hClu(S)) using the Gal4/UAS system. hClu(S) protein (~60 kDa) was detected in both adult homogenates and larval hemolymphs of flies ubiquitously overexpressing hClu(S) (da-Gal4>UAS-hClu(S)) and in motoneurons (D42-Gal4>UAS-hClu(S)). Interestingly, the mean lifespans of these hClu(S)-overexpressing flies were significantly greater than those of control flies that exhibited no hClu(S) induction. hClu(S)-overexpressing flies also showed significantly greater tolerance to heat shock, wet starvation, and oxidative stress. Furthermore, amounts of reactive oxygen species (ROS) in whole bodies were significantly lower in hClu(S)-overexpressing flies. In addition, clusterin was found to prevent the inactivation of glutamine synthetase (GS) by metal-catalyzed oxidation (MCO) in vitro, and this protection was only supported by thiol-reducing equivalents, such as, DTT or GSH, and not by ascorbate (a non-thiol MCO system). Furthermore, this protection against GS inactivation by clusterin was abolished by reacting clusterin with N-ethylmaleimide, a sulfhydryl group-modifying agent. Taken together, these results suggest that a disulfide-linked form of clusterin functions as an antioxidant protein via its cysteine sulfhydryl groups to reduce ROS levels and delay the organismal aging in fruit flies.

Effector-triggered immunity blocks pathogen degradation of an immunity-associated vesicle traffic regulator in Arabidopsis.

Innate immunity in plants can be triggered by microbe- and pathogen-associated molecular patterns. The pathogen-associated molecular pattern-triggered immunity (PTI) is often suppressed by pathogen effectors delivered into the host cell. Plants can overcome pathogen suppression of PTI and reestablish pathogen resistance through effector-triggered immunity (ETI). An unanswered question is how plants might overcome pathogen-suppression of PTI during ETI. Findings described in this paper suggest a possible mechanism. During Pseudomonas syringae pathovar tomato (Pst) DC3000 infection of Arabidopsis, a host ADP ribosylation factor guanine nucleotide exchange factor, AtMIN7, is destabilized by the pathogen effector HopM1 through the host 26S proteasome. In this study, we discovered that AtMIN7 is required for not only PTI, consistent with the notion that Pst DC3000 degrades AtMIN7 to suppress PTI, but also ETI. The AtMIN7 level in healthy plants is low, but increases posttranscriptionally in response to activation of PTI. Whereas DC3000 infection led to degradation of AtMIN7, activation of ETI by three different effectors, AvrRpt2, AvrPphB, and HopA1, in Col-0 plants blocks the ability of Pst DC3000 to destabilize AtMIN7. Further analyses of bacterial translocation of HopM1 and AtMIN7 stability in HopM1 transgenic plants show that ETI prevents HopM1-mediated degradation of AtMIN7 inside the plant cell. Both AtMIN7 and HopM1 are localized to the trans-Golgi network/early endosome, a subcellular compartment that is not previously known to be associated with bacterial pathogenesis in plants. Thus, blocking pathogen degradation of trans-Golgi network/early endosome-associated AtMIN7 is a critical part of the ETI mechanism to counter bacterial suppression of PTI.

Detection of sexually transmitted infection and human papillomavirus in negative cytology by multiplex-PCR.

BACKGROUND: The aim of this study was to determine the prevalence of human papillomavirus (HPV) and 15 species that cause sexually transmitted infections (STIs) in negative cytology. In addition, we compared the diagnostic performance of multiplex polymerase chain reaction (PCR) with widely available techniques used to detect HPV. METHODS: We recruited 235 women of reproductive age who had negative cytology findings in a liquid-based cervical smear. STIs were identified by multiplex PCR, and HPV genotypes by multiplex PCR, hybrid capture 2, and DNA microaray; discordant results were analyzed by direct sequencing. RESULTS: Approximately 96.6% of patients with negative cytology results were positive for pathogens that cause STIs. The pathogens most frequently detected were Gardnerella vaginalis, Ureaplasma urealyticum. The incidence of HPV in negative cytology was 23.3%. Low-risk HPV infection was significantly correlated with Chalmaydia trachomatis, and high-risk HPV infection was significantly correlated with Group ß streptococcus. The analytical sensitivities of the multiplex PCR and DNA microarray were higher than 80%, and the analytical specificity was nearly 100% for all tests. CONCLUSIONS: Multiplex PCR yielded results that most of patients with negative cytology were positive for pathogens that cause STIs, and were more similar to that of DNA microarray, than that of hybrid capture 2 in terms of analytical sensitivity and prediction value of HPV infection.

Broad-spectrum inhibition of retroviral and filoviral particle release by tetherin.

The expression of many putative antiviral genes is upregulated when cells encounter type I interferon (IFN), but the actual mechanisms by which many IFN-induced gene products inhibit virus replication are poorly understood. A recently identified IFN-induced antiretroviral protein, termed tetherin (previously known as BST-2 or CD317), blocks the release of nascent human immunodeficiency virus type 1 (HIV-1) particles from infected cells, and an HIV-1 accessory protein, Vpu, acts as a viral antagonist of tetherin. Here, we show that tetherin is capable of blocking not only the release of HIV-1 particles but also the release of particles assembled using the major structural proteins of a variety of prototype retroviruses, including members of the alpharetrovirus, betaretrovirus, deltaretrovirus, lentivirus, and spumaretrovirus families. Moreover, we show that the release of particles assembled using filovirus matrix proteins from Marburg virus and Ebola virus is also sensitive to inhibition by tetherin. These findings indicate that tetherin is a broadly specific inhibitor of enveloped particle release, and therefore, inhibition is unlikely to require specific interactions with viral proteins. Nonetheless, tetherin colocalized with nascent virus-like particles generated by several retroviral and filoviral structural proteins, indicating that it is present at, or recruited to, sites of particle assembly. Overall, tetherin is potentially active against many enveloped viruses and likely to be an important component of the antiviral innate immune defense.

Ergosterol and Water Changes in Tricholoma matsutake Soil Colony during the Mushroom Fruiting Season.

The purpose of this study is to understand spatio-temporal changes of active fungal biomass and water in Tricholoma matsutake soil colonies during the mushroom fruiting season. The active fungal biomass was estimated by analyzing ergosterol content at four different points within four replicated locations in a single circular T. matsutake colony at Ssanggok valley in the Sogri Mt. National Park in Korea during 2003 to 2005. The four points were the ahead of the colony, the front edge of the colony and 20 cm and 40 cm back from the front edge of the colony. Ergosterol content was 0.0 to 0.7 µg per gram dried soil at the ahead, 2.5 to 4.8 µg at the front edge, 0.5 to 1.8 µg at the 20 cm back and 0.3 to 0.8 µg at the 40 cm back. The ergosterol content was very high at the front edge where the T. matsutake hyphae were most active. However, ergosterol content did not significantly change during the fruiting season, September to October. Soil water contents were lower at the front edge and 20 cm back from the front edge of the colony than at the ahead and 40 cm back during the fruiting season. Soil water content ranged from 12 to 19% at the ahead, 10 to 11% at the edge, 9 to 11% at the 20 cm back and 11 to 15% at the 40 cm back. Our results suggest that the active front edge of the T. matsutake soil colony could be managed in terms of water relation and T. matsutake ectomycorrhizal root development.

Cutting edge: IL-4 induces suppressor of cytokine signaling-3 expression in B cells by a mechanism dependent on activation of p38 MAPK.

The signaling cascade initiated by IL-4 is classically divisible into two major pathways: one mediated by STAT6, and the other by insulin receptor substrates-1 and -2 via activation of PI3K. In murine splenic B cells, the suppressor of cytokine signaling (SOCS)3 is inducible by IL-4 via a mechanism independent of STAT6 and PI3K. SOCS3 expression increases 9-fold within 5 h of IL-4 treatment. This induction occurs normally in B cells deficient in STAT6 and is unaffected by pretreatment with the PI3K inhibitor wortmannin, or with the ERK pathway inhibitor, PD98059. However, the IL-4 induction of SOCS3 is blocked by inhibitors of either the JNK or p38 MAPK pathways (SP600125 and SB203580, respectively). Direct examination of these pathways reveals rapid, IL-4-directed activation of p38 MAPK, uncovering a previously unappreciated pathway mediating IL-4 signal transduction.

Cyclophilin A regulates TCR signal strength in CD4+ T cells via a proline-directed conformational switch in Itk.

Cyclophilin A (CypA/Ppia) is a peptidyl-prolyl isomerase (PPIase) that binds the immunosuppressive drug cyclosporine. The resulting complex blocks T cell function by inhibiting the calcium-dependent phosphatase calcineurin. To identify the native function of CypA, long suspected of regulating signal transduction, we generated mice lacking the Ppia gene. These animals develop allergic disease, with elevated IgE and tissue infiltration by mast cells and eosinophils, that is driven by CD4+ T helper type II (Th2) cytokines. Ppia(-/-) Th2 cells were hypersensitive to TCR stimulation, a phenotype consistent with increased activity of Itk, a Tec family tyrosine kinase crucial for Th2 responses. CypA bound Itk via the PPIase active site. Mutation of a conformationally heterogeneous proline in the SH2 domain of Itk disrupted interaction with CypA and specifically increased Th2 cytokine production from wild-type CD4+ T cells. Thus, CypA inhibits CD4+ T cell signal transduction in the absence of cyclosporine via a regulatory proline residue in Itk.

Production of ribosome components in effector CD4+ T cells is accelerated by TCR stimulation and coordinated by ERK-MAPK.

Effector CD4+ T cells rapidly activate high-level cytokine expression following TCR stimulation. Consistent with accelerated protein production in these cells, global mRNA profiles revealed that, after cytokines, the most impressive cluster of activated genes encode rRNA-maturation factors. Activation of these genes was ERK-MAPK dependent, accompanied by increased rRNA transcription and faster maturation kinetics, and much greater in effector CD4+ T cells than in naive cells. Ribosomal protein subunit (RPS) synthesis was also ERK-MAPK dependent and increased to match rRNA production, but without evident increase in RPS mRNA. Instead, stimulation promoted polysome loading of RPS mRNA via cis-acting, 5'-terminal oligopyrimidines. These results demonstrate how, in response to extracellular signals, effector CD4+ T cells coordinately increase multiple ribosomal components to accommodate burgeoning cytokine production.