To develop high‐performance thermally activated delayed fluorescence (TADF) exciplex emitters, a novel strategy of introducing a single‐molecule TADF emitter as one of the constituting materials has ...been presented. Such a new type of exciplex TADF emitter will have two reverse intersystem crossing (RISC) routes on both the pristine TADF molecules and the exciplex emitters, benefiting the utilization of triplet excitons. Based on a newly designed and synthesized single‐molecule TADF emitter MAC, a highly efficient exciplex emitter MAC:PO‐T2T has been obtained. The device based on MAC:PO‐T2T with a weight ratio of 7:3 exhibits a low turn‐on voltage of 2.4 V, high maximum efficiency of 52.1 cd A−1 (current efficiency), 45.5 lm W−1 (power efficiency), and 17.8% (external quantum efficiency, EQE), as well as a high EQE of 12.3% at a luminance of 1000 cd m−2. The device shows the best performance among reported organic light‐emitting devices based on exciplex emitters. Such high‐efficiency and low‐efficiency roll‐off should be ascribed to the additional reverse intersystem crossing process on the MAC molecules, showing the advantages of the strategy described in this study.
A new type of high‐performance exciplex thermally activated delayed fluorescence TADF emitter is demonstrated by introducing single‐molecule TADF emitter as one of the constituting materials. The OLED based on the novel emitter shows a low turn‐on voltage of 2.4 V and a maximum external quantum efficiency of 17.8% with mild efficiency roll‐off, which offers a new strategy for designing efficient exciplex emitters.
This study introduces a recent field experiment investigating multiscale terrain–circulation–precipitation interactions. When a synoptic‐scale northeasterly wind prevails under the active East Asian ...winter monsoon, stratocumulus cloud decks with severe rainfall exceeding 100 mm·day−1 frequently occur in the northeastern plain area and adjacent mountains in Yilan, Taiwan. The Yilan Experiment of Severe Rainfall (YESR2020) is a field campaign from November 20, 2020, to November 24, 2020, to survey the physical processes leading to severe wintertime rainfall. The three‐dimensional structure of the wind field and the atmospheric environment can be identified through high temporal and spatial resolution sounding observations, which is empowered by the novel Storm Tracker mini‐radiosonde. During YESR2020, the continuously collected meteorological data of two northeasterly episodes captured the variability of local‐scale wind patterns and the features of the severe rainfall induced by stratocumulus. A preliminary analysis indicated that a local‐scale convergence line could appear over the plain area of Yilan under the northeasterly environmental condition. The precipitation hotspot was located in the mountain region of southern Yilan, where the local winds signified turbulence features. Moreover, the severe rainfall of the two northeasterly episodes spotlighted shallow cumulus under stratus with pure warm rain processes. The results of YESR2020 inspire the arrangement of future field observations to explore detailed mechanisms of heavily precipitating stratocumulus over complex topography.
We conducted the Yilan Experiment of Severe Rainfall (YESR2020) to survey physical processes leading to severe rainfall in the northeastern plain area and adjacent mountains in Yilan, Taiwan, when a synoptic‐scale northeasterly wind prevails under the active East Asian winter monsoon with stratocumulus cloud decks. A preliminary analysis indicated that a local‐scale convergence line appeared over the plain area, and the precipitation hotspot was located in the mountain region of southern Yilan, where turbulence features were apparent. The results inspire the arrangement of future field observations to explore mechanisms of heavily precipitating stratocumulus over complex topography.
Bone defects are a common clinical issue, but therapeutic efficiency can be challenging in cases of more considerable traumas or elderly patients with degenerated physiological metabolism. To address ...this issue, a more suitable cell‐biomaterial construct promoting bone regeneration has been extensively investigated, with the chitosan scaffold being considered a potential candidate. In this study, chitosan was crosslinked with different doses of glucose (CTS‐10~50%Glc) using a modified Maillard reaction condition to develop a more appropriate cell‐biomaterial construct. Mouse MC3T3‐E1 pre‐osteoblasts were seeded onto the scaffolds to examine their osteoinductive capability. The results showed that CTS‐Glc scaffolds with higher glucose contents effectively improved the adhesion and survival of mouse MC3T3‐E1 pre‐osteoblasts and promoted their differentiation and mineralization. It was further demonstrated that the membrane integrin α5 subunit of pre‐osteoblasts is the primary adhesion molecule that communicates with CTS‐Glc scaffolds. After that, Akt signaling was activated, and then bone morphogenetic protein 4 was secreted to initiate the osteoinduction of pre‐osteoblasts. The prepared CTS‐Glc scaffold, with enhanced osteoinduction capability and detailed mechanism elucidations, offers a promising candidate material for advancing bone tissue engineering and clinical regenerative medicine. As a result, this study presents a potential tool for future clinical treatment of bone defects.
Among patients with chronic obstructive pulmonary disease (COPD), some have features of both asthma and COPD-a condition categorized as asthma-COPD overlap (ACO). Our aim was to determine whether ...asthma- or COPD-related microRNAs (miRNAs) play a role in the pathogenesis of ACO.
A total of 22 healthy subjects and 27 patients with ACO were enrolled. We selected 6 miRNAs that were found to correlate with COPD and asthma. The expression of miRNAs and target genes was analyzed using quantitative reverse-transcriptase polymerase chain reaction. Cell apoptosis and intracellular reactive oxygen species production were evaluated using flow cytometry. In vitro human monocytic THP-1 cells and primary normal human bronchial epithelial (NHBE) cells under stimuli with cigarette smoke extract (CSE) or ovalbumin (OVA) allergen or both were used to verify the clinical findings.
We identified the upregulation of miR-125b-5p in patients with ACO and in THP-1 cells stimulated with CSE plus OVA allergen. We selected 16 genes related to the miR-125b-5p pathway and found that IL6R and TRIAP1 were both downregulated in patients with ACO and in THP-1 cells stimulated with CSE plus OVA. The percentage of late apoptotic cells increased in the THP-1 cell culture model when stimulated with CSE plus OVA, and the effect was reversed by transfection with miR-125b-5p small interfering RNA (siRNA). The percentage of reactive oxygen species-producing cells increased in the NHBE cell culture model when stimulated with CSE plus OVA, and the effect was reversed by transfection with miR-125b-5p siRNA. In NHBE cells, siRNA transfection reversed the upregulation of STAT3 under CSE+OVA stimulation.
Our study revealed that upregulation of miR-125b-5p in patients with ACO mediated late apoptosis in THP-1 cells and oxidative stress in NHBE cells via targeting IL6R and TRIAP1. STAT3 expression was also regulated by miR-125b-5p.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
(Nees) Kuntze is a Chinese herbal medicine used in the treatment of respiratory virus infections. The methanol extract of
leaf contains chemical components such as β-sitosterol, indirubin, ...tryptanthrin, betulin, indigodole A, and indigodole B that have diverse biological activities. However, the antiviral action of
leaf and its components against human coronavirus remains to be elucidated. Human coronavirus NL63 infection is frequent among immunocompromised individuals, young children, and in the elderly. This study investigated the anti-Human coronavirus NL63 (HCoV-NL63) activity of the methanol extract of
leaf and its major components. The methanol extract of
leaf effectively inhibited the cytopathic effect (CPE) and virus yield (IC
= 0.64 μg/mL) in HCoV-NL63-infected cells. Moreover, this extract potently inhibited the HCoV-NL63 infection in a concentration-dependent manner. Among the six components identified in the methanol extract of
leaf, tryptanthrin and indigodole B (5a
-ethyltryptanthrin) exhibited potent antiviral activity in reducing the CPE and progeny virus production. The IC
values against virus yield were 1.52 μM and 2.60 μM for tryptanthrin and indigodole B, respectively. Different modes of time-of-addition/removal assay indicated that tryptanthrin prevented the early and late stages of HCoV-NL63 replication, particularly by blocking viral RNA genome synthesis and papain-like protease 2 activity. Notably, tryptanthrin (IC
= 0.06 μM) and indigodole B (IC
= 2.09 μM) exhibited strong virucidal activity as well. This study identified tryptanthrin as the key active component of
leaf methanol extract that acted against HCoV-NL63 in a cell-type independent manner.
against HCoV-NL63 infection.
Nonsaturating large magnetoresistance in semimetals Leahy, Ian A.; Lin, Yu-Ping; Siegfried, Peter E. ...
Proceedings of the National Academy of Sciences - PNAS,
10/2018, Letnik:
115, Številka:
42
Journal Article
Recenzirano
Odprti dostop
The rapidly expanding class of quantum materials known as topological semimetals (TSMs) displays unique transport properties, including a striking dependence of resistivity on applied magnetic field, ...that are of great interest for both scientific and technological reasons. So far, many possible sources of extraordinarily large nonsaturating magnetoresistance have been proposed. However, experimental signatures that can identify or discern the dominant mechanism and connect to available theories are scarce. Here we present the magnetic susceptibility (χ), the tangent of the Hall angle (tan θH
), along with magnetoresistance in four different nonmagnetic semimetals with high mobilities, NbP, TaP, NbSb₂, and TaSb₂, all of which exhibit nonsaturating large magnetoresistance (MR). We find that the distinctly different temperature dependences, χ(T), and the values of tan θH
in phosphides and antimonates serve as empirical criteria to sort the MR from different origins: NbP and TaP are uncompensated semimetals with linear dispersion, in which the nonsaturating magnetoresistance arises due to guiding center motion, while NbSb₂ and TaSb₂ are compensated semimetals, with a magnetoresistance emerging from nearly perfect charge compensation of two quadratic bands. Our results illustrate how a combination of magnetotransport and susceptibility measurements may be used to categorize the increasingly ubiquitous nonsaturating large magnetoresistance in TSMs.
Early confirmation of sustained virologic response (SVR) or viral relapse after direct‐acting antivirals (DAAs) for hepatitis C virus (HCV) infection is essential based on public health perspectives, ...particularly for patients with high risk of nonadherence to posttreatment follow‐ups. A total of 1011 patients who achieved end‐of‐treatment virologic response, including 526 receiving fixed‐dose pangenotypic DAAs, and 485 receiving other types of DAAs, who had available off‐treatment weeks 4 and 12 serum HCV RNA data to confirm SVR at off‐treatment week 12 (SVR12) or viral relapse were included. The positive predictive value (PPV) and negative predictive value (NPV) of SVR4 to predict patients with SVR12 or viral relapse were reported. Furthermore, we analyzed the proportion of concordance between SVR12 and SVR24 in 943 patients with available SVR24 data. The PPV and NPV of SVR4 to predict SVR12 were 98.5% (95% confidence interval CI: 98.0–98.9) and 100% (95% CI: 66.4–100) in the entire population. The PPV of SVR4 to predict SVR12 in patients receiving fixed‐dose pangenotypic DAAs was higher than those receiving other types of DAAs (99.8% 95% CI: 98.9–100 vs. 97.1% 95% CI: 96.2–97.8, p < 0.001). The NPVs of SVR4 to predict viral relapse were 100%, regardless of the type of DAAs. Moreover, the concordance between SVR12 and SVR24 was 100%. In conclusion, an off‐treatment week 4 serum HCV RNA testing is sufficient to provide an excellent prediction power of SVR or viral relapse at off‐treatment week 12 among patients with HCV who are treated with fixed‐dose pangenotypic DAAs.
Background
Benefited from advances in technology, virtual reality (VR) has been widely applied to learning content in operational training as well as hands‐on courses. However, most current studies ...tend to evaluate learning effectiveness in this application, and few were focused on how learners can be benefited from transferring the knowledge learned to real‐world field performance. Moreover, in application‐oriented hands‐on courses such as embedded electronic circuits, to our best knowledge, none were presented in interactive learning materials with the combination of VR and neither were the understanding of the changes in cognition, learning anxiety, and learning confidence during the learning process.
Method and Objective
We combine VR technology with hands‐on tasks to design a VR‐based embedded electronic circuit learning system. We conduct a quasi‐experiment to investigate differences in knowledge, comprehension, and application levels in different learning environments, and to assess learning performance, learning anxiety, and learning confidence levels when applying the knowledge learned to real‐world hands‐on tasks.
Results
Groups that receive VR‐mediated training exhibit superior knowledge, comprehension, and application levels. In addition, learners with higher levels of knowledge and application exhibit lower learning anxiety and higher learning confidence during practical application tasks.
Conclusions
We investigate the learning outcomes of learners on practical hands‐on tasks after VR‐mediated learning. To improve the learning experience and performance for learners in an embedded electronic circuit course, we discuss the learning performance in terms of the knowledge and concepts learned in the VR environment and transferred to the real world. The results show that learners achieve better cognitive levels in the learning process through the VR system described here. Better performance on hands‐on tasks was also obtained as well as low anxiety and high confidence levels.
Lay Description
What Is Already Known about this Topic
Multimedia learning materials are important for improving hands‐on practical ability.
Multimedia learning materials are already being used to promote learning effectiveness and outcomes.
There is a significant impact on learning anxiety and learning confidence in the cognitive process.
What this Paper Adds
Embedded electronic circuits course presented by IVR reduces learning anxiety and increases learning confidence in the hands‐on practical task.
Through IVR learning, students can construct their knowledge better and be able to perform better in hands‐on tasks.
Implications for Practice and/or Policy
We show the effectiveness of a hands‐on embedded electronic circuit course when transferring and applying knowledge to real‐world hands‐on tasks after learning in a virtual environment.
Learners exhibit better performance on practical hands‐on tasks, as well as lower anxiety and higher confidence levels.
Future work could explore adaptive factors by learners such as feedback and prompts given by learners in the VR learning environment to better understand the changes and effects in learners' cognitive processes.
What Are the 1 or 2 Major Takeaways from the Study
According to these results, the combination of IVR in hands‐on courses is an effective learning method, which can effectively improve students' knowledge, comprehension, and application ability.
We reveal the potential for hands‐on embedded courses to outperform traditional lecture courses through VR learning. Learners exhibit higher confidence and lower anxiety in the process of hands‐on practice.
Stachydrine, a prominent bioactive alkaloid derived from Leonurus heterophyllus, is a significant herb in traditional medicine. It has been noted for its anti-inflammatory and antioxidant ...characteristics. Consequently, we conducted a study of its hepatoprotective effect and the fundamental mechanisms involved in acetaminophen (APAP)-induced liver injury, utilizing a mouse model. Mice were intraperitoneally administered a hepatotoxic dose of APAP (300 mg/kg). Thirty minutes after APAP administration, mice were treated with different concentrations of stachydrine (0, 2.5, 5, and 10 mg/kg). Animals were sacrificed 16 h after APAP injection for serum and liver tissue assays. APAP overdose significantly elevated the serum alanine transferase levels, hepatic pro-inflammatory cytokines, malondialdehyde activity, phospho-extracellular signal-regulated kinase (ERK), phospho-protein kinase B (AKT), and macrophage-stimulating protein expression. Stachydrine treatment significantly decreased these parameters in mice with APAP-induced liver damage. Our results suggest that stachydrine may be a promising beneficial target in the prevention of APAP-induced liver damage through attenuation of the inflammatory response, inhibition of the ERK and AKT pathways, and expression of macrophage-stimulating proteins.
We hypothesized that epigenetics is a link between smoking/allergen exposures and the development of Asthma and chronic obstructive pulmonary disease (ACO). A total of 75 of 228 COPD patients were ...identified as ACO, which was independently associated with increased exacerbations. Microarray analysis identified 404 differentially methylated loci (DML) in ACO patients, and 6575 DML in those with rapid lung function decline in a discovery cohort. In the validation cohort, ACO patients had hypermethylated PDE9A (+ 30,088)/ZNF323 (- 296), and hypomethylated SEPT8 (- 47) genes as compared with either pure COPD patients or healthy non-smokers. Hypermethylated TIGIT (- 173) gene and hypomethylated CYSLTR1 (+ 348)/CCDC88C (+ 125,722)/ADORA2B (+ 1339) were associated with severe airflow limitation, while hypomethylated IFRD1 (- 515) gene with frequent exacerbation in all the COPD patients. Hypermethylated ZNF323 (- 296) / MPV17L (+ 194) and hypomethylated PTPRN2 (+ 10,000) genes were associated with rapid lung function decline. In vitro cigarette smoke extract and ovalbumin concurrent exposure resulted in specific DNA methylation changes of the MPV17L / ZNF323 genes, while 5-aza-2'-deoxycytidine treatment reversed promoter hypermethylation-mediated MPV17L under-expression accompanied with reduced apoptosis and decreased generation of reactive oxygen species. Aberrant DNA methylations may constitute a determinant for ACO, and provide a biomarker of airflow limitation, exacerbation, and lung function decline.
PDF
