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1.
PLoS One ; 19(5): e0301714, 2024.
Article in English | MEDLINE | ID: mdl-38713679

ABSTRACT

The development of intelligent education has led to the emergence of knowledge tracing as a fundamental task in the learning process. Traditionally, the knowledge state of each student has been determined by assessing their performance in previous learning activities. In recent years, Deep Learning approaches have shown promising results in capturing complex representations of human learning activities. However, the interpretability of these models is often compromised due to the end-to-end training strategy they employ. To address this challenge, we draw inspiration from advancements in graph neural networks and propose a novel model called GELT (Graph Embeddings based Lite-Transformer). The purpose of this model is to uncover and understand the relationships between skills and questions. Additionally, we introduce an energy-saving attention mechanism for predicting knowledge states that is both simple and effective. This approach maintains high prediction accuracy while significantly reducing computational costs compared to conventional attention mechanisms. Extensive experimental results demonstrate the superior performance of our proposed model compared to other state-of-the-art baselines on three publicly available real-world datasets for knowledge tracking.


Subject(s)
Knowledge , Neural Networks, Computer , Humans , Deep Learning , Algorithms
2.
Nature ; 2024 May 22.
Article in English | MEDLINE | ID: mdl-38778106

ABSTRACT

Two-dimensional (2D) semiconductors have shown great potential for monolithic three-dimensional (M3D) integration due to their dangling-bonds-free surface and the ability to integrate to various substrates without the conventional constraint of lattice matching1-10. However, with atomically thin body thickness, 2D semiconductors are not compatible with various high-energy processes in microelectronics11-13, where the M3D integration of multiple 2D circuit tiers is challenging. Here we report an alternative low-temperature M3D integration approach by van der Waals (vdW) lamination of entire prefabricated circuit tiers, where the processing temperature is controlled to 120 °C. By further repeating the vdW lamination process tier by tier, an M3D integrated system is achieved with 10 circuit tiers in the vertical direction, overcoming previous thermal budget limitations. Detailed electrical characterization demonstrates the bottom 2D transistor is not impacted after repetitively laminating vdW circuit tiers on top. Furthermore, by vertically connecting devices within different tiers through vdW inter-tier vias, various logic and heterogeneous structures are realized with desired system functions. Our demonstration provides a low-temperature route towards fabricating M3D circuits with increased numbers of tiers.

3.
Phytomedicine ; 128: 155543, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38657364

ABSTRACT

BACKGROUND: Ershiwuwei Zhenzhu pills was originally recorded in the Tibetan medical book Si Bu Yi Dian in the 8th century AD and is now included in the Pharmacopoeia of the People's Republic of China (2020). The pills can calm the nerves and open the mind as well as treat cerebral ischemia reperfusion injury, stroke, hemiplegia. However, its quality standards have not yet been established, and the therapeutic effect on cerebral ischemia by regulating the mitochondrial apoptosis pathway has not been elucidated. STUDY DESIGN AND METHODS: LC-MS was used to establish quality standards for Ershiwuwei Zhenzhu pills. Metabonomics, molecular docking, neuroethology, cerebral infarction ratio, pathological detection of diencephalon, cortex, and hippocampus, and molecular biology techniques were used to reveal the mechanism of the pills in regulating the mitochondrial apoptosis pathway to treat cerebral ischemia. RESULTS: The contents of 20 chemical components in Ershiwuwei Zhenzhu pills from 12 batches and 8 manufacturers was determined for the first time. Eleven differential metabolites and three metabolic pathways, namely, fructose and mannose metabolism, glycerophospholipid metabolism, and purine metabolism, were identified by metabonomics. The pills improved the neuroethology abnormalities of MCAO rats and the pathological damage in the diencephalon and decreased the ratio of cerebral infarction. It also significantly reduced the mRNA expression of AIF, Apaf-1, cleared caspase8, CytC, and P53 mRNA in the brain tissue and the protein expression of Apaf-1 and CYTC and increased the protein expression of NDRG4. CONCLUSION: In vitro quantitative analysis of the in vitro chemical components of Ershiwuwei Zhenzhu pills has laid the foundation for improving its quality control. The potential mechanism of the pills in treating cerebral ischemia may be related to the Apaf-1/CYTC/NDRG4 apoptosis pathway. This work provides guidance for clinical drug use for patients.


Subject(s)
Apoptotic Protease-Activating Factor 1 , Brain Ischemia , Drugs, Chinese Herbal , Metabolomics , Rats, Sprague-Dawley , Animals , Brain Ischemia/drug therapy , Male , Drugs, Chinese Herbal/pharmacology , Rats , Apoptotic Protease-Activating Factor 1/metabolism , Apoptosis/drug effects , Chromatography, Liquid , Molecular Docking Simulation , Medicine, Tibetan Traditional , Mass Spectrometry , Liquid Chromatography-Mass Spectrometry
4.
Nano Lett ; 24(12): 3768-3776, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38477579

ABSTRACT

The reduced dimensionality and interfacial effects in magnetic nanostructures open the feasibility to tailor magnetic ordering. Here, we report the synthesis of ultrathin metallic Co2Si nanoplates with a total thickness that is tunable to 2.2 nm. The interfacial magnetism coupled with the highly anisotropic nanoplate geometry leads to strong perpendicular magnetic anisotropy and robust hard ferromagnetism at room temperature, with a Curie temperature (TC) exceeding 950 K and a coercive field (HC) > 4.0 T at 3 K and 8750 Oe at 300 K. Theoretical calculations suggest that ferromagnetism originates from symmetry breaking and undercoordinated Co atoms at the Co2Si and SiO2 interface. With protection by the self-limiting intrinsic oxide, the interfacial ferromagnetism of the Co2Si nanoplates exhibits excellent environmental stability. The controllable growth of ambient stable Co2Si nanoplates as 2D hard ferromagnets could open exciting opportunities for fundamental studies and applications in Si-based spintronic devices.

5.
J Anim Physiol Anim Nutr (Berl) ; 108(1): 194-205, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37675629

ABSTRACT

Inflammatory response induced by biological stress usually occurs in weaning piglets, it reduces the production performance of piglets and even causes death. Tert-butylhydroquinone (TBHQ) is a food additive that has the effect of anti-inflammation and anti-oxidation. However, there are few reports related to the protective mechanisms of TBHQ on lipopolysaccharide (LPS) induced injury in intestinal porcine epithelial (IPEC-J2) cells. Quantitative real-time polymerase chain reaction and western blot analysis, respectively, detected the mRNA levels and protein expressions related to pyroptosis, tight junction (TJ) protein and high-mobility group box 1/toll-like receptor 4/nuclear factor kappa-B (HMGB1/TLR4/NF-κB) axis. Localisation and expression of NOD-like receptor pyrin domain containing 3 (NLRP3), HMGB1 and P-NF-κB proteins detected by immunofluorescence. The results showed that TBHQ (12.5 and 25 µM) can increase cell activity and reduce intracellular lactate dehydrogenase (LDH) levels in a dose-dependent manner. LPS significantly decreases cell viability and increases the LDH level. However, pretreatment with TBHQ evidently increases cell viability and decreases the LDH level of IPEC-J2 cells. In addition, treatment with LPS decreased the mRNA level and protein expression of zonula occludens-1, occludin and claudin-1, and increased the mRNA level and protein expression of pyroptosis and HMGB1/TLR4/NF-κB axis. Interestingly, pretreatment with TBHQ increased the TJ protein expressions as well as decreased the mRNA level and protein expressions of pyroptosis and HMGB1/TLR4/NF-κB axis. Moreover, the results of immunofluorescence showed that TBHQ significantly reduced the expression of NLRP3, HMGB1 and P-NF-κB in LPS-induced injury of IPEC-J2 cells. Therefore, we come to the conclusion that TBHQ attenuates LPS-induced pyroptosis in IPEC-J2 cells through downregulation of the HMGB1/TLR4/NF-κB axis, TBHQ may become a potential feed additive for preventing inflammatory diarrhoea in piglets.


Subject(s)
HMGB1 Protein , NF-kappa B , Animals , Swine , NF-kappa B/genetics , NF-kappa B/metabolism , Lipopolysaccharides/toxicity , NLR Family, Pyrin Domain-Containing 3 Protein , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism , Pyroptosis , HMGB1 Protein/genetics , HMGB1 Protein/metabolism , RNA, Messenger
6.
J Ethnopharmacol ; 319(Pt 2): 117310, 2024 Jan 30.
Article in English | MEDLINE | ID: mdl-37827296

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Erigeron breviscapus is a common medicine of eight ethnic minorities, including Miao, Naxi, and Yi. As early as the Ming Dynasty (AD 1368-1644), Lanmao's Materia Medica of Southern Yunnan (AD 1436) recorded that the medicine is used for the treatment of "Zuo tan you huan." In modern pharmacological research, Erigeron breviscapus injection is the most commonly used preparation in the treatment of ischemic stroke caused by acute cerebral infarction, but its mechanism of action in the treatment of ischemic stroke is not well understood. AIM OF THE STUDY: In this study, a metabonomics study based on ultraperformance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS) was used in investigating the effect of a traditional Chinese medicine preparation Erigeron breviscapus injection on the rat model of focal cerebral ischemia-reperfusion and the affinity of its main components with the targets of mitochondrial apoptotic pathways. MATERIALS AND METHODS: This study used molecular docking technology to verify the effective binding ability of main effective components of Erigeron breviscapus injection to target proteins related to mitochondrial apoptosis pathway. This study developed a metabonomics method based on the ultra-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC Q-TOF MS) to evaluate the efficacy and study the mechanism of traditional Chinese medicine preparation. With pattern recognition analysis (principal component analysis and partial least squares-discriminate analysis) of urinary metabolites, a clear separation of focal cerebral ischemia-reperfusion model group and healthy control group was achieved. RESULTS: Erigeron breviscapus injection can significantly reduce the area of cerebral infarction, improve tissue morphological lesion in rats, and can increase the number of Nissl bodies. It may be a promoting factor by inhibiting hippocampal nerve cell apoptosis and Bax protein expression and by exerting effects against ischemia reperfusion after the induction of apoptosis. Thus, it plays a role in brain protection. Moreover, it can considerably promote the recovery of neurological deficiency signs in advance. Meanwhile, Erigeron breviscapus decreased malondialdehyde content and T-NOS activity. Its curative effect from strong to weak order: low dose > high dose > medium dose. The representative components of Erigeron breviscapus have good affinity with the active sites of mitochondrial apoptosis-related proteins. Metabolomics found that the potential biomarkers regulated by breviscapine are kynurequinolinic acid, succinylornithine, and leucine proline. It is speculated that it may participate in TRP-kynurequinolinic acid and succinylornithine-urea cycle-NO metabolic pathways. CONCLUSIONS: This paper revealed the potential biomarkers and metabolic pathways regulated by Erigeron breviscapus. It was speculated that the mechanism is related to its inhibition of mitochondrion-mediated apoptosis. Erigeron breviscapus could restore the metabolic profiles of the model animals to normal animal levels. The mechanism may be related to the potential biomarkers of quinolinic acid, succinylornithine, and leucine proline and the metabolic pathways involved. However, the exact mechanism by which Erigeron breviscapus inhibits mitochondrion-mediated apoptosis remains to be further explored.


Subject(s)
Brain Ischemia , Erigeron , Ischemic Stroke , Reperfusion Injury , Rats , Animals , Erigeron/chemistry , Molecular Docking Simulation , Leucine/therapeutic use , China , Metabolomics/methods , Brain Ischemia/drug therapy , Reperfusion Injury/drug therapy , Reperfusion Injury/prevention & control , Tandem Mass Spectrometry , Cerebral Infarction , Biomarkers , Proline , Chromatography, High Pressure Liquid
8.
Nano Lett ; 23(23): 11034-11042, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38038404

ABSTRACT

WSe2 has a high mobility of electrons and holes, which is an ideal choice as active channels of electronics in extensive fields. However, carrier-type tunability of WSe2 still has enormous challenges, which are essential to overcome for practical applications. In this work, the direct growth of n-doped few-layer WSe2 is realized via in situ defect engineering. The n-doping of WSe2 is attributed to Se vacancies induced by the H2 flow purged in the cooling process. The electrical measurements based on field effect transistors demonstrate that the carrier type of WSe2 synthesized is successfully transferred from the conventional p-type to the rarely reported n-type. The electron carrier concentration is efficiently modulated by the concentration of H2 during the cooling process. Furthermore, homomaterial inverters and self-powered photodetectors are fabricated based on the doping-type-tunable WSe2. This work reveals a significant way to realize the controllable carrier type of two-dimensional (2D) materials, exhibiting great potential in future 2D electronics engineering.

9.
ACS Nano ; 17(15): 14954-14962, 2023 Aug 08.
Article in English | MEDLINE | ID: mdl-37459447

ABSTRACT

Strain engineering has been proposed as a promising method to boost the carrier mobility of two-dimensional (2D) semiconductors. However, state-of-the-art straining approaches are largely based on putting 2D semiconductors on flexible substrates or rough substrate with nanostructures (e.g., nanoparticles, nanorods, ripples), where the observed mobility change is not only dependent on channel strain but could be impacted by the change of dielectric environment as well as rough interface scattering. Therefore, it remains an open question whether the pure lattice strain could improve the carrier mobilities of 2D semiconductors, limiting the achievement of high-performance 2D transistors. Here, we report a strain engineering approach to fabricate highly strained MoS2 transistors on a flat substrate. By mechanically laminating a prefabricated MoS2 transistor onto a custom-designed trench structure on flat substrate, well-controlled strain can be uniformly generated across the 2D channel. In the meantime, the substrate and the back-gate dielectric layer remain flat without any roughness-induced scattering effect or variation of the dielectric environment. Based on this technique, we demonstrate the MoS2 electron mobility could be enhanced by tension strain and decreased by compression strain, consistent with theoretical predictions. The highest mobility enhancement is 152% for monolayer MoS2 and 64% for bilayer MoS2 transistors, comparable to that of a silicon device. Our method not only provides a compatible approach to uniformly strain the layered semiconductors on flat and solid substrate but also demonstrates an effective method to boost the carrier mobilities of 2D transistors.

10.
Nano Lett ; 23(6): 2179-2186, 2023 Mar 22.
Article in English | MEDLINE | ID: mdl-36862981

ABSTRACT

Two-dimensional (2D) materials with large linear magnetoresistance (LMR) are very interesting owing to their potential application in magnetic storage or sensor devices. Here, we report the synthesis of 2D MoO2 nanoplates grown by a chemical vapor deposition (CVD) method and observe large LMR and nonlinear Hall behavior in MoO2 nanoplates. As-obtained MoO2 nanoplates exhibit rhombic shapes and high crystallinity. Electrical studies indicate that MoO2 nanoplates feature a metallic nature with an excellent conductivity of up to 3.7 × 107 S m-1 at 2.5 K. MoO2 nanoplates display a large LMR of up to 455% at 3 K and -9 T. A thickness-dependent LMR analysis suggests that LMR values increase upon increasing the thickness of nanoplates. Besides, nonlinearity has been found in the magnetic-field-dependent Hall resistance, which decreases with increasing temperatures. Our studies highlight that MoO2 nanoplates are promising materials for fundamental studies and potential applications in magnetic storage devices.

11.
Nat Commun ; 14(1): 1014, 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36823424

ABSTRACT

Van der Waals (vdW) metallic contacts have been demonstrated as a promising approach to reduce the contact resistance and minimize the Fermi level pinning at the interface of two-dimensional (2D) semiconductors. However, only a limited number of metals can be mechanically peeled and laminated to fabricate vdW contacts, and the required manual transfer process is not scalable. Here, we report a wafer-scale and universal vdW metal integration strategy readily applicable to a wide range of metals and semiconductors. By utilizing a thermally decomposable polymer as the buffer layer, different metals were directly deposited without damaging the underlying 2D semiconductor channels. The polymer buffer could be dry-removed through thermal annealing. With this technique, various metals could be vdW integrated as the contact of 2D transistors, including Ag, Al, Ti, Cr, Ni, Cu, Co, Au, Pd. Finally, we demonstrate that this vdW integration strategy can be extended to bulk semiconductors with reduced Fermi level pinning effect.

12.
Nat Commun ; 14(1): 304, 2023 Jan 19.
Article in English | MEDLINE | ID: mdl-36658123

ABSTRACT

Most of the current methods for the synthesis of two-dimensional materials (2DMs) require temperatures not compatible with traditional back-end-of-line (BEOL) processes in semiconductor industry (450 °C). Here, we report a general BiOCl-assisted chemical vapor deposition (CVD) approach for the low-temperature synthesis of 27 ultrathin 2DMs. In particular, by mixing BiOCl with selected metal powders to produce volatile intermediates, we show that ultrathin 2DMs can be produced at 280-500 °C, which are ~200-300 °C lower than the temperatures required for salt-assisted CVD processes. In-depth characterizations and theoretical calculations reveal the low-temperature processes promoting 2D growth and the oxygen-inhibited synthetic mechanism ensuring the formation of ultrathin nonlayered 2DMs. We demonstrate that the resulting 2DMs exhibit electrical, magnetic and optoelectronic properties comparable to those of 2DMs grown at much higher temperatures. The general low-temperature preparation of ultrathin 2DMs defines a rich material platform for exploring exotic physics and facile BEOL integration in semiconductor industry.

13.
Adv Mater ; 35(16): e2210755, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36719342

ABSTRACT

Antiferromagnets with noncollinear spin order are expected to exhibit unconventional electromagnetic response, such as spin Hall effects, chiral abnormal, quantum Hall effect, and topological Hall effect. Here, 2D thickness-controlled and high-quality Cr5 Si3 nanosheets that are compatible with the complementary metal-oxide-semiconductor technology are synthesized by chemical vapor deposition method. The angular dependence of electromagnetic transport properties of Cr5 Si3 nanosheets is investigated using a physical property measurement system, and an obvious topological Hall effect (THE) appears at a large tilted magnetic field, which results from the noncollinear magnetic structure of the Cr5 Si3 nanosheet. The Cr5 Si3 nanosheets exhibit distinct thickness-dependent perpendicular magnetic anisotropy (PMA), and the THE only emerges in the specific thickness range with moderate PMA. This work provides opportunities for exploring fundamental spin-related physical mechanisms of noncollinear antiferromagnet in ultrathin limit.

14.
Adv Mater ; 35(12): e2207895, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36581586

ABSTRACT

2D metal oxides (2DMOs) have stimulated tremendous attention due to their distinct electronic structures and abundant surface chemistry. However, it remains a standing challenge for the synthesis of 2DMOs because of their intrinsic 3D lattice structure and ultrahigh synthesis temperature. Here, a reliable WSe2 -assisted chemical vapor deposition (CVD) strategy to grow nonlayered WO2 nanoplates with tunable thickness and lateral dimension is reported. Optical microscopy and scanning electron microscopy studies demonstrate that the WO2 nanoplates exhibit a well-faceted rhombic geometry with a lateral dimension up to the sub-millimeter level (≈135 µm), which is the largest size of 2DMO single crystals obtained by CVD to date. Scanning transmission electron microscopy studies reveal that the nanoplates are high-quality single crystals. Electrical measurements show the nanoplates exhibit metallic behavior with strong anisotropic resistance, outstanding conductivity of 1.1 × 106  S m-1 , and breakdown current density of 7.1 × 107  A cm-2 . More interestingly, low-temperature magnetotransport studies demonstrate that the nanoplates show a quantum-interference-induced weak-localization effect. The developed WSe2 -assisted strategy for the growth of WO2 nanoplates can enrich the library of 2DMO materials and provide a material platform for other property explorations based on 2D WO2 .

15.
Ginekol Pol ; 94(5): 350-357, 2023.
Article in English | MEDLINE | ID: mdl-35419789

ABSTRACT

OBJECTIVES: Predictors of gestational diabetes mellitus (GDM) recurrence (GDMR) was determined in southern Chinese women. MATERIAL AND METHODS: A total of 376 women with GDM who had two consecutive singleton deliveries at our hospital between January 2014 and October 2020 were enrolled in the current study. We retrospectively compared the clinical characteristics, fasting plasma glucose level (FPG-1), and oral glucose tolerance test-1h-1 and -2h-1 (OGTT 1hr-1: 1-h post-load glucose level during the first pregnancy and OGTT 2hr-1: 2-h post-load glucose level during the first pregnancy) for the first pregnancy between patients in the GDMR group (n = 166) and the non-GDMR group (n = 210). RESULTS: The incidence of GDMR in the study population was 44.15%. During the first pregnancy, women in the GDMR group had significantly higher OGTT 1h-1, OGTT 2h-1, and FPG-1 + OGTT 1h + 2h-1 compared to the non-GDMR group. When the threshold of the FPG-1 + OGTT 1h + 2h-1 level in the first pregnancy was > 23.6 mmol/L, the specificity for predicting GDMR was 0.85, the sensitivity was 0.45, and the area under the receiver operating characteristic curve (ROC-AUC) was 0.70, indicating a 70% probability of predicting GDMR in the next pregnancy. Logistic regression analysis showed that patients with a combined abnormal FPG-1 + OGTT 1h + 2 h-1 level had a 10-fold increased risk for GDMR in subsequent pregnancies than patients with normal indicators (OR: 10.542, 95% CI: 3.097-35.881; p < 0.0001). CONCLUSIONS: The OGTT 1h-1 and OGTT 2h-1 are independent risk factors for GDMR in southern Chinese women. Women with an FPG-1 + OGTT 1h + 2h-1 threshold level > 23.6 mmol/L in the first pregnancy had a 10-fold greater probability of developing GDMR in the second pregnancy than women in the non-GDMR group.


Subject(s)
Diabetes, Gestational , Pregnancy , Humans , Female , Diabetes, Gestational/diagnosis , Diabetes, Gestational/epidemiology , Retrospective Studies , Blood Glucose/analysis , East Asian People , Risk Factors
16.
Front Immunol ; 13: 1015224, 2022.
Article in English | MEDLINE | ID: mdl-36389805

ABSTRACT

African swine fever virus (ASFV) is a complex large DNA enveloped virus that causes African swine fever (ASF) with a fatality rate of up to 100%, seriously threatening the global swine industry. Due to the strict cell tropism of ASFV, there is no effective in vitro cell line, which hinders its prevention and control. Herein, we analyzed genome-wide transcriptional profiles of ASFV-susceptible porcine alveolar macrophages (PAMs) and non-susceptible cell lines PK15 and 3D4-21, an found that PAM surface pattern recognition receptors (PRRs) were significantly higher and common differential genes were significantly enriched in phagocytosis compared with that observed in PK15 and 3D4-21 cell lines. Therefore, endocytosis functions of host cell surface PRRs may play key roles in ASFV infection in vitro. ASFV was found to be infective to PK15 and 3D4-21 cell lines overexpressing CD163 and Siglec1, and to the PK15S1-CD163 cell line stably expressing CD163 and Siglec1. However, the PK15 and 3D4-21 cell lines overexpressing CD163 or Siglec1 alone were not infectious. Simultaneous interference of CD163 and Siglec1 in PAMs with small interfering RNA (siRNA) significantly reduced the infectivity of ASFV. However, siRNA interference of CD163 and Siglec1 respectively did not affect ASFV infectivity. ASFV significantly inhibited IFN expression levels in PAMs and PK15S1-CD163 cells, but had no effect on PK15 and 3D4-21 cell lines. These results indicate that CD163 and Siglec1 are key receptors for ASFV-infected host cells, and both play a synergistic role in the process of ASFV infection. ASFV inhibits IFN expression in susceptible cells, thereby downregulating the host immune response and evading the immune mechanism. The discovery of the ASFV receptor provides novel ideas to study ASFV and host cell interactions, pathogenic mechanisms, development of receptor blockers, vaccine design, and disease resistance breeding.


Subject(s)
African Swine Fever Virus , African Swine Fever , Swine , Animals , African Swine Fever Virus/genetics , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Kidney/metabolism
17.
Molecules ; 27(20)2022 Oct 14.
Article in English | MEDLINE | ID: mdl-36296475

ABSTRACT

The low-lying HOMO level of the blue emitter and the interfacial miscibility of organic materials result in inferior hole injection, and long exciton lifetime leads to triplet-triplet annihilation (TTA) and triplet-polaron annihilation (TPA), so the efficiencies of blue phosphorescent organic light-emitting diodes (PhOLEDs) are still unsatisfactory. Herein, we design co-host and co-dopant structures to improve the efficiency of blue PhOLEDs by means of solution processing. TcTa acts as hole transport ladder due to its high-lying HOMO level, and bipolar mCPPO1 helps to balance carriers' distribution and weaken TPA. Besides the efficient FIr6, which acts as the dominant blue dopant, FCNIrPic was introduced as the second dopant, whose higher HOMO level accelerates hole injection and high triplet energy facilitates energy transfer. An interesting phenomenon caused by microcavity effect between anode and cathode was observed. With increasing thickness of ETL, peak position of electroluminescence (EL) spectrum red shifts gradually. Once the thickness of ETL exceeded 140 nm, emission peak blue-shifts went back to its original position. Finally, the maximum current efficiency (CE), power efficiency (PE), and external quantum efficiency (EQE) of blue phosphorescent organic light-emitting diode (PhOLED) went up to 20.47 cd/A, 11.96 lm/W, and 11.62%, respectively.

18.
Front Chem ; 10: 965927, 2022.
Article in English | MEDLINE | ID: mdl-36186581

ABSTRACT

In this work, di-[4-(N,N-ditolylamino)-phenyl]cyclohexane (TAPC); 4,4',4″-tri (9-carbazoyl)triphenylamine (TcTa); 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi); and 1,3,5-tri (m-pyrid-3-yl-phenyl)benzene (TmPyPB) were used to constitute the multiple-host system and fabricate solution-processed organic light-emitting diodes (s-OLEDs) with europium complex Eu(DBM)3Phen (DBM, 1,3-diphenylpropane-1,3-dione; Phen,1,10-phenanthroline) as emitter. In order to determine the optimal composition of the multiple-host system, a series of devices with different light-emitting layers (EMLs) were fabricated and compared. Experimental results revealed that removing TmPyPB out of the multiple-host system greatly reduces the turn-on voltage, whereas the addition of TcTa to the multiple-host system helps facilitate the transfer of holes from TAPC to Eu(DBM)3Phen molecules, thus increasing the recombination probability of carriers on emitter molecules. Finally, high performance solution-processed red OLED (turn-on voltage of 3.8 V) based on the europium complex doped multiple-host system obtained the maximum current efficiency of 2.07 cd A-1, power efficiency of 1.54 lm W-1, external quantum efficiency of 1.2%, and brightness of 945 cd m-2.

19.
Front Immunol ; 13: 870174, 2022.
Article in English | MEDLINE | ID: mdl-35812436

ABSTRACT

Background: Intracerebral hemorrhage (ICH) is the devastating subtype of stroke with cardiovascular complications, resulting in high rates of mortality and morbidity with the release of inflammatory factors. Previous studies have demonstrated that activation of α7nAChR can reduce immune and inflammation-related diseases by triggering the cholinergic anti-inflammatory pathway (CAIP). α7nAChR mediates protection from nervous system inflammation through AMPK-mTOR-p70S6K-associated autophagy. Therefore, the purpose of this study is to explore whether the activation of α7nAChR improves cerebral and cardiac dysfunction after ICH through autophagy. Methods: Male C57BL/6 mice were randomly divided into five groups (1): Control + saline (2), ICH+ saline (3), ICH + PNU-282987 (4), ICH+ PNU-282987 + MLA (5), ICH + PNU-282987 + 3-MA. The neurological function was evaluated at multiple time points. Brain water content was measured at 3 days after ICH to assess the severity of brain edema. PCR, immunofluorescence staining, and Western Blot were performed at 7 days after ICH to detect inflammation and autophagy. Picro-Sirius Red staining was measured at 30 days after ICH to evaluate myocardial fibrosis, echocardiography was performed at 3 and 30 days to measure cardiac function. Results: Our results indicated that the PNU-282987 reduced inflammatory factors (MCP-1, IL-1ß, MMP-9, TNF-α, HMGB1, TLR2), promoted the polarization of macrophage/microglia into anti-inflammatory subtypes(CD206), repaired blood-brain barrier injury (ZO-1, Claudin-5, Occludin), alleviated acute brain edema and then recovered neurological dysfunction. Echocardiography and PSR indicated that activation of α7nAChR ameliorated cardiac dysfunction. Western Blot showed that activation of α7nAChR increased autophagy protein (LC3, Beclin) and decreased P62. It demonstrated that the activation of α7nAChR promotes autophagy and then recovers brain and heart function after ICH. Conclusions: In conclusion, PNU-282987 promoted the cerebral and cardiac functional outcomes after ICH in mice through activated α7nAChR, which may be attributable to promoting autophagy and then reducing inflammatory reactions after ICH.


Subject(s)
Brain Edema , Heart Diseases , Animals , Autophagy , Brain Edema/etiology , Cerebral Hemorrhage/metabolism , Disease Models, Animal , Inflammation/complications , Male , Mice , Mice, Inbred C57BL , Neuroimmunomodulation , alpha7 Nicotinic Acetylcholine Receptor
20.
ACS Nano ; 16(7): 10623-10631, 2022 Jul 26.
Article in English | MEDLINE | ID: mdl-35735791

ABSTRACT

The limitation on the spintronic applications of van der Waals layered transition-metal dichalcogenide semiconductors is ascribed to the intrinsic nonmagnetic feature. Recent studies have proved that substitutional doping is an effective route to alter the magnetic properties of two-dimensional transition-metal dichalcogenides (TMDs). However, highly valid and repeatable substitutional doping of TMDs remains to be developed. Herein, we report group VIII magnetic transition metal-doped molybdenum diselenide (MoSe2) single crystals via a one-pot mixed-salt-intermediated chemical vapor deposition method with high controllability and reproducibility. The high-angle annular dark-field scanning transmission electron microscopy studies further confirm that the sites of Fe are indeed substitutionally incorporated into the MoSe2 monolayer. The Fe-doped MoSe2 monolayer with a concentration from 0.93% to 6.10% could be obtained by controlling the ratios of FeCl3/Na2MoO4. Moreover, this strategy can be extended to create Co(Ni)-doped MoSe2 monolayers. The magnetic hysteresis (M-H) measurements demonstrate that group VIII magnetic transition-metal-doped MoSe2 samples exhibit room-temperature ferromagnetism. Additionally, the Fe-doped MoSe2 field effect transistor shows n-type semiconductor characteristics, indicating the obtainment of a room-temperature dilute magnetic semiconductor. Our approach is universal in magnetic transition-metal substitutional doping of TMDs, and it inspires further research interest in the study of related spintronic and magnetoelectric applications.

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