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Graphene films that can theoretically block almost all molecules have emerged as promising candidate materials for moisture barrier films in the applications of organic photonic devices and gas storage. However, the current barrier performance of graphene films does not reach the ideal value. Here, we reveal that the interlayer distance of the large-area stacked multilayer graphene is the key factor that suppresses water permeation. We show that by minimizing the gap between the two monolayers, the water vapor transmission rate of double-layer graphene can be as low as 5 × 10-3 g/(m2 d) over an A4-sized region. The high barrier performance was achieved by the absence of interfacial contamination and conformal contact between graphene layers during layer-by-layer transfer. Our work reveals the moisture permeation mechanism through graphene layers, and with this approach, we can tailor the interlayer coupling of manually stacked two-dimensional materials for new physics and applications.
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Blood-brain barrier (BBB) damage can be a result of central nervous system (CNS) diseases and may be a cause of CNS deterioration. However, there are still many unknowns regarding effective and targeted therapies for maintaining BBB integrity during ischemia/reperfusion (I/R) injury. In this study, we demonstrate that the circular RNA of FoxO3 (circ-FoxO3) promotes autophagy via mTORC1 inhibition to attenuate BBB collapse under I/R. Upregulation of circ-FoxO3 and autophagic flux were detected in brain microvessel endothelial cells in patients with hemorrhagic transformation and in mice models with middle cerebral artery occlusion/reperfusion. In vivo and in vitro studies indicated that circ-FoxO3 alleviated BBB damage principally by autophagy activation. Mechanistically, we found that circ-FoxO3 inhibited mTORC1 activity mainly by sequestering mTOR and E2F1, thus promoting autophagy to clear cytotoxic aggregates for improving BBB integrity. These results demonstrate that circ-FoxO3 plays a novel role in protecting against BBB damage, and that circ-FoxO3 may be a promising therapeutic target for neurological disorders associated with BBB damage.
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Isquemia Encefálica , Traumatismo por Reperfusão , Animais , Autofagia/genética , Barreira Hematoencefálica/metabolismo , Células Endoteliais/metabolismo , Proteína Forkhead Box O3/genética , Proteína Forkhead Box O3/metabolismo , Humanos , Infarto da Artéria Cerebral Média/complicações , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Camundongos , RNA Circular/genética , Reperfusão/efeitos adversos , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/genéticaRESUMO
Acute kidney injury (AKI) is a serious disorder associated with significant morbidity and mortality. AKI and ischemia/reperfusion (hypoxia/reoxygenation, H/R) injury can be induced due to several reasons. Paeoniflorin (PF) is a traditional herbal medicine derived from Paeonia lactiflora Pall. It exerts diverse therapeutic effects, including anti-inflammatory, antioxidative, antiapoptotic, and immunomodulatory properties; thus, it is considered valuable for treating several diseases. However, the effects of PF on H/R injury-induced AKI remain unknown. In this study, we established an in vitro H/R model using COCL2 and investigated the functions and underlying mechanisms of PF on H/R injury in HK-2 cells. The cell vitality was evaluated using the cell count kit-8 assay. The DCFH-DA fluorescence probe was used to measure the levels of reactive oxygen species (ROS). Oxidative damage was detected using superoxide dismutase (SOD) and malondialdehyde (MDA) assay kits. Apoptotic relative protein and Keap1/Nrf2/HO-1 signaling were evaluated by Western blotting. Our results indicated that PF increased cell viability and SOD activity and decreased the ROS and MDA levels in HK-2 cells with H/R injury. PF inhibits apoptosis by increasing Bcl-2 and decreasing Bax. Furthermore, PF significantly upregulated the expression of HO-1 and Nrf2, but downregulated the expression of HIF-1α and Keap1. PF considerably increased Nrf2 nuclear translocation and unregulated the HO-1 expression. The Nrf2 inhibitor (ML385) could reverse the abovementioned protective effects of PF, suggesting that Nrf2 can be a critical target of PF. To conclude, we found that PF attenuates H/R injury-induced AKI by decreasing the oxidative damage via the Nrf2/HO-1 pathway and inhibiting apoptosis.
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Injúria Renal Aguda , Traumatismo por Reperfusão , Humanos , Espécies Reativas de Oxigênio/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/farmacologia , Fator 2 Relacionado a NF-E2/uso terapêutico , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Transdução de Sinais , Estresse Oxidativo , Apoptose , Hipóxia , Superóxido Dismutase , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismoRESUMO
Viewing government-public relationships as important antecedents of individuals' health protection behaviors, this study uses a relationship management approach to examine COVID-19 vaccine promotion among local government agencies. The study hypothesizes that the quality of local government-public relationships is positively associated with pro-vaccine outcomes, including more frequent risk information seeking, pro-vaccine attitudes, and greater vaccination intention. In addition, an important pathway through which the government-public relationship promotes vaccination acceptance is by enhancing the public's risk perceptions. Using a representative community sample, findings support the positive roles of certain but not all relationship quality variables in predicting vaccine acceptance. Meanwhile, risk perceptions consistently predict risk information seeking, pro-vaccine attitudes, and vaccination intention.
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COVID-19 , Vacinas , Humanos , Vacinas contra COVID-19 , Governo Local , COVID-19/epidemiologia , COVID-19/prevenção & controle , Órgãos Governamentais , Comportamentos Relacionados com a Saúde , VacinaçãoRESUMO
Triboelectric nanogenerators (TENGs) and dielectric elastomer generators (DEGs) are potentially promising energy conversion technologies, but they still have limitations due to their own intrinsic characteristics, including the low energy output of TENGs caused by the air breakdown effect, and external polarization voltage requirement for DEGs, which severely limit their practical applications. Herein, coupling TENG with DEG is proposed to build a mutual beneficial self-excitation hybrid generator (named TDHG) for harvesting distributed and low-quality mechanical energy (high entropy energy). Experimental results demonstrate that the output charges of this TDHG are enhanced by fivefold of that of the conventional charge-excitation TENG, and continuous operation of DEG is also realized by simple mechanical triggering. More importantly, owing to the high peak power contributed by TENG and the long output pulse duration guaranteed by DEG, the TDHG realizes a much higher energy conversion efficiency of 32% in comparison to either the TENG (3.6%) or DEG (13.2%). This work proposes a new design concept for hybridized energy harvester toward highly efficient mechanical energy harvesting.
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Entropia , Frequência Cardíaca , Células Híbridas , Fenômenos FísicosRESUMO
The genomic and carbohydrate metabolic features of Pseudoalteromonas agarivorans Hao 2018 (P. agarivorans Hao 2018) were investigated through pan-genomic and transcriptomic analyses, and key enzyme genes that may encode the process involved in its extracellular polysaccharide synthesis were screened. The pan-genome of the P. agarivorans strains consists of a core-genome containing 2331 genes, an accessory-genome containing 956 genes, and a unique-genome containing 1519 genes. Clusters of Orthologous Groups analyses showed that P. agarivorans harbors strain-specifically diverse metabolisms, probably representing high evolutionary genome changes. The Kyoto Encyclopedia of Genes and Genomes and reconstructed carbohydrate metabolic pathways displayed that P. agarivorans strains can utilize a variety of carbohydrates, such as d-glucose, d-fructose, and d-lactose. Analyses of differentially expressed genes showed that compared with the stationary phase (24 h), strain P. agarivorans Hao 2018 had upregulated expression of genes related to the synthesis of extracellular polysaccharides in the logarithmic growth phase (2 h), and that the expression of these genes affected extracellular polysaccharide transport, nucleotide sugar synthesis, and glycosyltransferase synthesis. This is the first investigation of the genomic and metabolic features of P. agarivorans through pan-genomic and transcriptomic analyses, and these intriguing discoveries provide the possibility to produce novel marine drug lead compounds with high biological activity.
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Pseudoalteromonas , Transcriptoma , Carboidratos , Genoma Bacteriano/genética , Genômica , Filogenia , Pseudoalteromonas/genética , Pseudoalteromonas/metabolismoRESUMO
Exopolysaccharides (EPSs) are carbohydrate polymers produced and secreted by microorganisms. In a changing marine environment, EPS secretion can reduce damage from external environmental disturbances to microorganisms. Meanwhile, EPSs have promising application prospects in the fields of food, cosmetics, and pharmaceuticals. Changes in external environmental pH have been shown to affect the synthesis of EPSs in microorganisms. In this study, we analyzed the effects of different initial fermentation pHs on the production, monosaccharide composition, and antioxidant activity of the EPSs of Pseudoalteromonas agarivorans Hao 2018. In addition, the transcriptome sequence of P. agarivorans Hao 2018 under different initial fermentation pH levels was determined. GO and KEGG analyses showed that the differentially expressed genes were concentrated in the two-component regulatory system and bacterial chemotaxis pathways. We further identified the expression of key genes involved in EPS synthesis during pH changes. In particular, the expression of genes encoding the glucose/galactose MFS transporter, phosphomannomutase, and mannose-1-phosphate guanylyltransferase was upregulated when the environmental pH increased, thus promoting EPS synthesis. This study not only contributes to elucidating the environmental adaptation mechanisms of P. agarivorans, but also provides important theoretical guidance for the directed development of new products using biologically active polysaccharides.
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Antioxidantes/isolamento & purificação , Polissacarídeos Bacterianos/isolamento & purificação , Pseudoalteromonas/metabolismo , Antioxidantes/química , Antioxidantes/farmacologia , Fermentação , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Concentração de Íons de Hidrogênio , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Pseudoalteromonas/genéticaRESUMO
In times of public health emergencies, health agencies need to engage and communicate with the public in real-time to share updates and accurate information. This is especially the case for the COVID-19 pandemic where public engagement can potentially save lives and flatten the curve. This paper considers how the use of interactive features and strategic network positions of health agencies on social media influenced their public engagement outcomes. Specifically, we analyzed 203 U.S. public health agencies' Twitter activity and the public engagement they received by extracting data from a large-scale Twitter dataset collected from January 21st to May 31st, 2020. Results show that health agencies' network position in addition to their two-way communication strategy greatly influenced the level of public engagement with their COVID-19 related content on Twitter. Findings highlight the benefits of strategic social media communication of public health agencies resides not only in how agencies use social media but also in their formation of network position to amplify their visibility. As official sources of health and risk information, public health agencies should coordinate their social media communication efforts to strategically position themselves in advantageous network positions to augment public engagement outcomes.
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COVID-19 , Mídias Sociais , COVID-19/epidemiologia , Comunicação , Humanos , Pandemias , Saúde PúblicaRESUMO
The high-performance filter capacitor is a hot research topic in the field of filter circuits for flexible and wearable devices, whereas traditional aluminum electrolytic capacitors still experience widespread problems in terms of large error factors and poor stability. To avoid these disadvantages, in this work, we have developed a liquid dual-layer supercapacitor (SC). When it is employed as the filter capacitor in a filter circuit, any waveform signal can be transformed into a linear signal. The maximum fluctuation of the output signal is less than 16 mV; the SC also demonstrates excellent filtering stability in a frequency range of 1 â¼ 100 000 Hz, as well as an amplitude window of 0 â¼ 10 V. In this framework, our filter SC demonstrates unparalleled processing properties, and can greatly improve the stability and extend the lifetime of the entire electronic circuit. The fact that the requirements of high-end electronic products can be fulfilled due to the contribution of this filter SC are particularly significant.
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Dialogic communication has long been viewed as vital for effective organization-public relations. Yet, it is under-theorized whether and how organizations' disaster communication messages may embody dialogic communication principles, and how various dialogic features are associated with different public engagement outcomes on social media. Extending the Organization-Public Dialogic Communication (OPDC) framework to the context of social media-mediated disaster communication, we propose a multi-level framework to assess the dialogic capacity of Facebook messages sent by disaster management organizations during a natural disaster. Three levels of dialogic communication characteristics (i.e., message structure-level, topic-level, and linguistic level) are examined using content analysis and Linguistic Inquiry and Word Count (LIWC). Results identified media richness, correcting, and confirming topics as three consistent predictors of public engagement of all types. Meanwhile, there exhibit greater variations regarding how other topical features and linguistic characteristics are related to public's cognitive, emotional, and behavioral engagement during a disaster.
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AIMS: Shikonin is a naphthoquinone compound extracted from the root of Lithospermum with various pharmacological activities. Sympathetic neural remodeling greatly contributes to chronic heart failure. Growing evidence has identified a critical role of microRNAs (miRNAs) in a variety of cardiac biological processes. This study aimed to verify whether shikonin could attenuate sympathetic neural remodeling and explore the possible regulatory role of miRNAs in this process. MAIN METHODS: Shikonin was administered to mice after transverse aortic constriction (TAC). Immunohistochemistry and western blotting were used to assess the expression of TAC-induced sympathetic remodeling-related proteins. KEY FINDINGS: TAC-induced expression of the sympathetic remodeling-related proteins, tyrosine hydroxylase (TH), growth associated protein 43 (GAP43), choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), and nerve growth factor (NGF), was significantly decreased in cardiac tissues. MiR-124 expression significantly increased after heart failure and decreased after shikonin treatment. An adeno-associated virus 9 (AAV9) vector was packaged and used to transfect myocardial tissues of aortic-constricted mice with miR-124, resulting in increased heart miR-124 levels and inhibition of the effects of shikonin on sympathetic neural remodeling. Immunohistochemical staining showed that the density of TH-, GAP43-, and ChAT-positive nerves was significantly increased in aortic-constricted mice after transfection with AAV9-miR-124. SIGNIFICANCE: Our data demonstrate that shikonin administration prevents sympathetic neural remodeling in mice with TAC-induced heart failure. The effects of shikonin on heart failure may be partly due to miR-124-mediated attenuation of sympathetic remodeling. Our results reveal a novel mechanism underlying the therapeutic effect of shikonin in heart failure.
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Cardiotônicos/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , MicroRNAs/genética , Naftoquinonas/farmacologia , Animais , Doença Crônica , Constrição Patológica , Proteína GAP-43/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Masculino , Camundongos Endogâmicos C57BL , Miocárdio/metabolismo , Miocárdio/patologia , Sistema Nervoso Simpático/efeitos dos fármacos , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismoRESUMO
BACKGROUND: Advanced stage laryngeal squamous cell carcinoma (LSCC) presents a poor prognosis; thus, there is a great need to identify novel prognostic molecular markers. Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) is thought to be a novel prognostic factor in several cancers, but its role in LSCC remains unknown. Cancer stem cells (CSCs) are responsible for most instances of tumor recurrence and the development of drug resistance and have been proven to be present in head and neck cancers. Our preliminary study indicated that PLOD2 was elevated in LSCC tissues; therefore, we hypothesized that PLOD2 is related to the prognosis of LSCC patients and aimed to explore the role and underlying mechanism of PLOD2 in LSCC. METHODS: We validated the prognostic role of PLOD2 in 114 LSCC patients by immunohistochemistry. Stable PLOD2-overexpressing Hep-2 and FaDu cells were established and assessed by molecular biology and biochemistry methods both in vitro and in vivo. RESULTS: We confirmed that PLOD2 overexpression was correlated with poor prognosis in LSCC patients. PLOD2 overexpression strengthened the CSC-like properties of Hep-2 and FaDu cells, activated the Wnt signaling pathway and conferred drug resistance in LSCC in vitro and in vivo. CONCLUSIONS: We found that PLOD2 could serve as a prognostic marker in patients with LSCC and confer drug resistance in LSCC by increasing CSC-like traits; in addition, a Wnt-responsive CSC pathway was identified.
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Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Laríngeas/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antineoplásicos/farmacologia , Biomarcadores Tumorais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/mortalidade , Neoplasias Laríngeas/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/metabolismo , Prognóstico , Via de Sinalização Wnt , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
In recent years, the wide application of exopolysaccharides (EPSs) in food, cosmetics, medicine, and other fields has drawn tremendous attention. In this study, an EPS produced by Pseudoalteromonas agarivorans Hao 2018 was isolated and purified, and its fermentation conditions were optimized. Its structure and biological functions were also studied. The purity and molecular weight of EPS were determined by high performance liquid chromatography (HPLC), and the EPS exhibited a number average of 2.26 × 105 and a weight average of 2.84 × 105. EPS has good adsorption for Cu2+ and Pb2+. The adsorption rates can reach up to 69.79% and 82.46%, respectively. The hygroscopic property of EPS was higher than that of chitosan, but slightly lower than that of sodium hyaluronate. However, the water-retaining activity of EPS was similar to that of chitosan and sodium hyaluronate. EPS has strong ability to scavenge free radicals, including OH radical and O2- radical. Further, its activity on O2- radicals has similarities with that of vitamin C. EPS has broad application prospects in many fields, such as cosmetics, environmental protection.
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Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Pseudoalteromonas/metabolismo , Adsorção , Cobre/química , Fermentação , Sequestradores de Radicais Livres , Chumbo/química , Polissacarídeos Bacterianos/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Based on multi-scale characteristics inherent in the cracking process of cementitious composites, fibers with different geometric dimensions are simultaneously used to restrain the formation and development of cracks at different scales. Accordingly, hybrid fiber-reinforced cementitious composites (HyFRCCs) exhibit excellent bond behavior and deformation capacity in terms of tension and compression, accompanied by higher damage tolerance. Using these benefits of the mechanical properties of HyFRCCs, the structural performance of HyFRCC structures under complex loading conditions can be improved. To objectively evaluate the contributions of all fibers to the mechanical properties of HyFRCCs, steel macro-fibers, and polyvinyl alcohol (PVA) micro-fibers were used to design several reinforced cementitious composites. Four of the specimens were mono-fibrous cementitious composites, three specimens were cementitious composites reinforced with hybrid fibers, and one was a non-fibrous cementitious composite. The synergy effect of the steel and PVA fibers was analyzed using various fiber combinations. The results indicated a significant enhancement of the bonding properties of HyFRCCs through the incorporation of PVA and steel fibers. Specifically, the peak bond strength, peak slip displacement, and residual bond strength exhibited increments ranging from 31.0% to 41.7%, 60.6% to 118.4%, and 34.6% to 391.3%, respectively, in comparison to the reference test block. Notably, the combined presence of the PVA and steel fibers consistently demonstrated a positive confounding effect on the residual bond strength. However, negative confounding effects were observed in terms of the peak bond strength and peak slip displacement, particularly with 1.0% steel fiber content and 0.5% PVA fiber content.
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UBE2M, a NEDD8-conjugating enzyme, is dysregulated in various human cancers and promotes tumor cell proliferation. However, its role in estrogen receptor-positive (ER+) breast cancer remains unknown. We found that UBE2M expression was significantly higher in ER+ breast cancer tissues than in ER-negative (ER-) breast cancer tissues. Higher expression of UBE2M indicated a poorer prognosis in patients with ER+ breast cancer but not in those with ER- breast cancer. Of interest, a positive feedback loop was observed between UBE2M and ERα. Specifically, ERα enhanced the HIF-1α-mediated transcription of UBE2M. In turn, UBE2M maintained ERα expression by inhibiting its ubiquitination and degradation through UBE2M-CUL3/4A-E6AP-ERα axis. Functionally, silencing of UBE2M suppressed the growth of breast cancer cells by inducing cell cycle arrest and apoptosis and improved their sensitivity to fulvestrant both in vitro and in vivo. Altogether, our findings reveal that the UBE2M-ERα feedback loop drives breast cancer progression and fulvestrant resistance, suggesting UBE2M as a viable target for endocrine therapy of ER+ breast cancer.
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Neoplasias da Mama , Resistencia a Medicamentos Antineoplásicos , Receptor alfa de Estrogênio , Retroalimentação Fisiológica , Enzimas de Conjugação de Ubiquitina , Humanos , Enzimas de Conjugação de Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/tratamento farmacológico , Feminino , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Animais , Progressão da Doença , Camundongos Nus , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Camundongos , Apoptose/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Fulvestranto/farmacologia , Ubiquitinação , Células MCF-7RESUMO
The dissection of the genetic architecture and the detection of the loci for adaptive traits are important for marker-assisted selection (MAS) for breeding. A spring wheat diversity panel with 251 cultivars, mainly from China, was obtained to conduct a genome-wide association study (GWAS) to detect the new loci, including the heading date (HD), maturating date (MD), plant height (PH), and lodging resistance (LR). In total, 41 loci existing in all 21 chromosomes, except for 4A and 6B, were identified, and each explained 4.3-18.9% of the phenotypic variations existing in two or more environments. Of these, 13 loci are overlapped with the known genes or quantitative trait loci (QTLs), whereas the other 28 are likely to be novel. The 1A locus (296.9-297.7 Mb) is a multi-effect locus for LR and PH, whereas the locus on chromosome 6D (464.5-471.0 Mb) affects both the HD and MD. Furthermore, four candidate genes for adaptive traits were identified, involved in cell division, signal transduction, and plant development. Additionally, two competitive, allele-specific PCR (KASP) markers, Kasp_2D_PH for PH and Kasp_6D_HD for HD, were developed and validated in another 162 spring wheat accessions. Our study uncovered the genetic basis of adaptive traits and provided the associated SNPs and varieties with more favorable alleles for wheat MAS breeding.
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The high-intactness and ultraclean fabrication of suspended 2D materials has always been a challenge due to their atomically thin nature. Here, we present a universal polymer-free transfer approach for fabricating suspended 2D materials by using volatile micro-molecule cyclododecane as the transfer medium, thus ensuring the ultraclean and intact surface of suspended 2D materials. For the fabricated monolayer suspended graphene, the intactness reaches 99% for size below 10 µm and suspended size reaches 36 µm. Owing to the advantages of ultra-cleanness and large size, the thermal conductivity reaches 4914 W m - 1 K - 1 at 338 K. Moreover, this strategy can also realize efficient batch transfer of suspended graphene and is applicable for fabricating other 2D suspended materials such as MoS2. Our research not only establishes foundation for potential applications and investigations of intrinsic properties of large-area suspended 2D materials, but also accelerates the wide applications of suspended graphene grid in ultrahigh-resolution TEM characterization.
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The disparity between growth substrates and application-specific substrates can be mediated by reliable graphene transfer, the lack of which currently strongly hinders the graphene applications. Conventionally, the removal of soft polymers, that support the graphene during the transfer, would contaminate graphene surface, produce cracks, and leave unprotected graphene surface sensitive to airborne contaminations. In this work, it is found that polyacrylonitrile (PAN) can function as polymer medium for transferring wafer-size graphene, and encapsulating layer to deliver high-performance graphene devices. Therefore, PAN, that is compatible with device fabrication, does not need to be removed for subsequent applications. The crack-free transfer of 4 in. graphene onto SiO2/Si wafers, and the wafer-scale fabrication of graphene-based field-effect transistor arrays with no observed clear doping, uniformly high carrier mobility (≈11 000 cm2 V-1 s-1), and long-term stability at room temperature, are achieved. This work presents new concept for designing the transfer process of 2D materials, in which multifunctional polymer can be retained, and offers a reliable method for fabricating wafer-scale devices of 2D materials with outstanding performance.
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The real applications of chemical vapor deposition (CVD)-grown graphene films require the reliable techniques for transferring graphene from growth substrates onto application-specific substrates. The transfer approaches that avoid the use of organic solvents, etchants, and strong bases are compatible with industrial batch processing, in which graphene transfer should be conducted by dry exfoliation and lamination. However, all-dry transfer of graphene remains unachievable owing to the difficulty in precisely controlling interfacial adhesion to enable the crack- and contamination-free transfer. Herein, through controllable crosslinking of transfer medium polymer, the adhesion is successfully tuned between the polymer and graphene for all-dry transfer of graphene wafers. Stronger adhesion enables crack-free peeling of the graphene from growth substrates, while reduced adhesion facilitates the exfoliation of polymer from graphene surface leaving an ultraclean surface. This work provides an industrially compatible approach for transferring 2D materials, key for their future applications, and offers a route for tuning the interfacial adhesion that would allow for the transfer-enabled fabrication of van der Waals heterostructures.